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Notes: The Zermatt-Saas serpentinite complex is an integral member of the Penninic ophiolites of the Central Alps and represents the mantle part of the oceanic lithosphere of the Tethys. Metamorphic textures of the serpentinite preserve the complex mineralogical evolution from primary abyssal peridotite through ocean-floor hydration, subduction-related high-pressure overprint, meso-Alpine greenschist facies metamorphism, and late-stage hydrothermal alteration. The early ocean floor hydration of the spinel harzburgites is still visible in relic pseudomorphic bastite and locally preserved mesh textures. The primary serpentine minerals were completely replaced by antigorite. The stable assemblage in subduction-related mylonitic serpentinites is antigorite–olivine–magnetite ± diopside. The mid-Tertiary greenschist facies overprint is characterized by minor antigorite recrystallization. Textural and mineral composition data of this study prove that the hydrated mineral assemblages remained stable during high-pressure metamorphism of up to 2.5 GPa and 650 °C. The Zermatt-Saas serpentinites thus provide a well documented example for the lack of dehydration of a mantle fragment during subduction to 75 km depth.

Notes: Abstract  This study examined tuberculosis (TB) knowledge in Latino immigrants receiving latent TB infection (LTBI) therapy. The study design was descriptive correlational. Knowledge was measured using the LTBI Knowledge Instrument. The convenience sample included 82 Latino immigrants primarily from Central America and Bolivia who attended a public health clinic for their LTBI therapy. The mean TB knowledge score was 66%. Knowledge scores were correlated with years of education, but not with age or number of years in the United States. More than 80% of study participants correctly answered questions about the importance of keeping monthly appointments and how Isoniazid works to eradicate TB germs in the human body. Questions that pertained to the contagiousness of active TB and how the disease spreads received the most incorrect responses. Public health nursing interventions should focus on increasing Latino immigrants' knowledge of TB, both in public health clinics and in the community.

Notes: Abstract  Geographic information systems (GIS) offer public health nurses a new technology to plan and implement interventions within communities. The present article gives a brief overview of GIS, describes a project designed to pilot-test the use of GIS for developing population-based interventions, and discusses lessons learned from the project that need to be applied to any future work. Using GIS to map the incidence and prevalence of disease, locate risk factors, and identify access to health care services is not difficult. Trying to move beyond that and use the technology to depict community networks and develop and implement population-based interventions is more problematic. The project identified specific questions that anyone involved in a planning or decision-making project in which GIS are used should ask.

Notes: Abstract  The number of reported child abuse cases is on the increase in Japan. This report describes the testing of an approach to prevention based on a key question: “Do you find any of your children irritating?” The study employed a focus group and a survey. The focus group consisted of 13 mothers who had been severely abusive to their children and were undergoing individual psychotherapy in Tokyo. The survey included 1,538 mothers living with at least one child less than 6 years of age in metropolitan Tokyo. The survey questionnaire asked about mothers' attitudes toward their children and about details and frequency of possibly abusive behavior for their children. All 13 mothers of the focus group reported the experience of feeling their children irritating. They talked extensively and provided many details of their feelings. Of the survey mothers, 3.6% reported feeling their children irritating and showed high scores of abusive behavior. There was a difference in attribution of source of the irritation between these mothers and focus-group mothers. We conclude that the question on irritability is effective in eliciting mothers' feelings and behavior, especially for providing public health nurses with an opportunity for intervention in child abuse.

Notes: Abstract  Many states have introduced home visitation programs to improve the health of mothers and newborn infants. In South Carolina, the Postpartum/Infant Home Visit (P/IHV) program seeks to provide all Medicaid-eligible mothers and infants with at least one home visit by a nurse or other qualified health professional. In the summer 2002, the authors conducted a cost-benefit analysis of the P/IHV program using both qualitative and quantitative methods. This article describes the qualitative methods and findings from the larger study. Focus groups were held with nurses who provide P/IHV visits to gain insight into the structure and functioning of the P/IHV program, to hear firsthand the nurses' experiences with the program, and to provide guidance in developing the empiric model for measuring cost-benefit. Analysis of the focus-group data suggests that what actually occurs during a home visit is fairly standardized. Nurses indicated that they were knowledgeable about community resources and services available to the families they serve. Referral processes were identified as an important factor in determining whether a mother receives a home visit. Overall, the nurses felt that the home visit program has had a positive impact on the health and well-being of the mothers and infants served.

Notes: Abstract  The purpose of this article is to describe experiences and challenges in establishing a South Asian Pap Test Clinic. The specialized Pap test clinic for immigrant South Asian women was a community-initiated response to high rates of cervical cancer within this population. Efforts were made to ensure that the clinic provided health services in a sensitive and culturally appropriate manner. Although women were generally positive about their experiences at the South Asian Pap Test Clinic and often encouraged other women to attend the clinic for Pap testing, attendance patterns have not been maintained. The three most significant challenges to the clinic's ongoing success were: (1) maintaining the continued involvement of stakeholders in developing long-term strategies to enhance community awareness about cervical cancer; (2) creating mechanisms to strengthen support from physicians in the community; and (3) meeting the needs of the underserved within a specialized health service for South Asian immigrant women. These challenges provide important lessons for others to increase the participation of immigrant women in screening practices. Nurses can play a key role in mobilizing and maintaining collaborations that are essential to the continuing success of community-based programs.

Notes: Abstract  An evaluation was conducted to describe the personal impact of the “In Your Care” pregnancy prevention intervention program using Baby Think It Over™ infant simulator. Data was collected regarding the attitudes, actual and intended sexual practices, feelings, and opinions of participants 2 or 3 years after the intervention. Student recommendations for program continuation and improvement were also solicited. Male and female 11th grade students in rural and suburban Midwestern communities, who had experienced the program 2 or 3 years earlier, completed surveys and were interviewed in focus groups. Participants vividly recalled and described the simulated experience in statements that reflected insight and feelings about parental responsibility and the consequences of teen pregnancy. The teens also made several recommendations for enhancing the program. The findings suggest that simulated experiences can be a powerful strategy for effective learning about complex decisions regarding the risks of sexual activity and the realities of parenting.

Notes: Abstract  This study compared the changes in health behaviors, motivation, and functional status between motivation enhancement exercise-program participants and program dropouts over 6 months. A total of 73 older adults living in residential homes participated in the study. Face-to-face interviews were conducted at pretest and then at 10 weeks and 6 months in the program. The participants exercised using traditional Korean dance movements for 50 min, 4 times per week, for 6 months. The subjects were classified as participants or dropouts by using a cutoff attendance rate of 80%. Repeated ANOVA revealed the following results over 6 months:〈list style="custom"〉1The motivation to perform health behaviors, especially for perceived benefits, improved significantly for the participants than for the dropouts.2Significant differences in the performance of overall health behaviors and exercise-related behaviors were found between the participants and the dropouts.3The sickness impact profile (SIP) of the participants improved significantly, compared with the dropouts. Significant group differences were found for total SIP, physical dimensions, and enjoyment of recreation and pastimes.In conclusion, the study found that the 6-month motivation enhancement program was effective in motivating older adults to perform health behaviors and to improve their functional status.

Notes: Abstract  Reducing and eliminating racial and ethnic health disparities has become a national research priority. This research agenda requires new research frameworks that encompass the social determinants of health and the translation pathways of these social contexts into physiological morbidity. Within these sociobiological research frameworks, identity and emotions are seen as crucial links in the causal pathways from stressors to biological responses. In this country, the lived social reality of African American individuals is experienced through the color of their skin. Their identity is bound with the racial inequities of our society. It has been suggested that the emotions of anger and frustration resulting from this institutionalized racial discrimination are an emotional causative pathway to the pathophysiology contributing to the health disparities experienced by African Americans. However, as much as we espouse the concept of cultural competency in health care, until recently, there has been very little honest dialogue about how race and racism influences health. This article will explore the Black–White cultural perception gap and attempt to provide insight on the relationship to African American health and implications for health disparities research.

Notes: Abstract  Young women often have difficulty accessing and correctly using contraception. However, these difficulties are not primarily the result of lack of knowledge or experience of contraception. In this study, nine adolescent mothers were interviewed about their experience of contraception before and after the birth of their children. These adolescent women faced barriers to effective contraceptive use before the birth of their children. These barriers included indifference to the possibility of pregnancy, perceived invulnerability to pregnancy, and forgetting to use contraception regularly. Analysis also revealed that during the time these women were sexually active prior to pregnancy, many had used a range of strategies to overcome these barriers to effective contraception, including using adult support, allowing an adult to take responsibility for contraception, and using multiple methods of contraception to cover for contraceptive failure. The strategies used by these women to delay childbearing indicate valuable areas for further research in preventing unplanned adolescent pregnancy.

Notes: Abstract  If public health nursing is truly a synthesis of public health science and nursing science, then nurses must keep track of current developments in public health science. Unfortunately, the public health nursing literature has not kept pace with revolutionary developments in epidemiology, one of the sciences that informs population-focused nursing practice. Most epidemiology chapters in community health nursing texts do not reflect the intellectual development that has taken place in epidemiology over the past two decades. The purpose of this article therefore is to facilitate an updated synthesis by (a) reviewing the development of epidemiology and the focus of public health nursing practice through three historical eras, (b) discussing current controversies and tensions within epidemiology, (c) introducing an emerging paradigm in epidemiology based on an ecosocial perspective, and (d) discussing the congruence of this perspective with the evolving theory and practice of public health nursing.

Notes: Abstract  United States law requires that immunization providers use Centers for Disease Control Vaccine Information Statements (VISs) and inform parents about vaccine risks and benefits prior to every childhood immunization. A recent national survey found that public health clinics (PHCs) reported high compliance with this law. To further investigate these findings, we conducted an immunization time-motion study in two PHCs in Kansas and Louisiana. Research assistants observed a convenience sample of 246 child immunization visits to record distribution of the VISs and content and time of vaccine communication. Thirty percent of parents read below a ninth grade level, 53% had Medicaid insurance, and 56% were Black. VISs were given with every dose of vaccine administered in 89% of visits. Public health nurses (PHNs) frequently discussed potential vaccine side effects (91%), treatment of side effects (91%), and the vaccine schedule (93%). Contraindications were screened in 71% of visits. Benefits were discussed in 48% of visits and severe risks in 29%. The national Vaccine Injury Compensation Program (VICP) was never discussed. The immunization visits lasted for a mean of 20 min. Vaccine communication of side effects, risks, benefits, screening for contraindications, and the next visit lasted for an average of 16 s for all vaccines. PHC compliance with mandated VIS distribution and practical vaccine communication was high. Room for improvement exists in discussion of benefits, serious risks, and the VICP.

Notes: Abstract  The study examined the relationship of early family environment and infant characteristics with childhood behavior problems at age 7 years. Sixty-two mothers and 56 fathers of preterm (30–36 weeks gestation and greater than 1500 g) and full-term boys and girls completed the Parenting Stress Index, Dyadic Adjustment Scale, and a measure of socioeconomic status during the child's first year. When their child was age 7 years, parents completed the Eyberg Child Behavior Inventory Intensity (frequency of behavior) and Problem (impact of behavior) scales. Hierarchical regression analyses showed that parenting stress because of their child's distractibility during infancy predicted the frequency of childhood behavior problems at age 7 years for mothers and of the impact of behaviors on the mother and the father. The quality of the marital relationship during infancy predicted the frequency of behavior problems reported by fathers. Public health nurses are well positioned to assess parenting stress and marital quality and to provide support to families during the early stages of parenthood.

Notes: Abstract  Health attitudes and behaviors develop in childhood and progress through adolescence into adulthood. To better understand the health risk behaviors being undertaken by a seventh-grade urban population, a study was conducted to identify what health risk behaviors a group of adolescents were participating in. The purpose of this study was to describe (1) the types of health risk behaviors being undertaken, (2) the frequency of their taking health risk behaviors, and (3) the age of initiation of the health risk behavior. The findings from this study indicate that this sample of 54, urban seventh graders suffers from multidimensional health needs. These students participated in a variety of health risk behaviors, as measured by the Youth Risk Behaviors Surveillance System Questionnaire. These students have begun to smoke regularly, which correlated with the use of alcohol. They rate their health as being good or excellent but rarely met the daily requirements for intake of fruits and vegetables. And, although they rate their weight as being acceptable, most are trying to lose weight. Additionally, differences between the boys and girls were noted in weight perception, with girls more likely than boys to use smoking as the primary method of weight control. Nursing is in an ideal position to provide effective primary care interventions and community health outreach to this adolescent population.

Notes: Abstract  The specific aims of the article were to: (i) compare childhood experiences of intimacy and autonomy as they occurred in the families of origin of women who have and women who have not experienced homelessness; (ii) compare social support, reciprocity, and conflict as they occurred in the childhood support networks and in the current support networks of women who have and women who have not experienced homelessness; (iii) examine the relationships between intimacy and autonomy in families of origin and the social support networks from childhood of women who have and women who have not experienced homelessness. Descriptive correlational design: 255 women were interviewed to determine levels of intimacy, autonomy, social support, reciprocity, and conflict in childhood relationships. The ANCOVA models for each of support, reciprocity, and conflict indicated a significant group effect. The post-hoc analysis for support indicated that the homeless group was significantly lower in support and reciprocity and significantly higher in conflict than the never-homeless groups. The never-homeless, never-abused group scored significantly higher on autonomy and intimacy than the homeless or the never-homeless, abused groups. This study demonstrates the significance of families of origin and learning how to develop and utilize support systems in preventing or reducing homelessness.

Notes: Abstract  The use of geographic information system (GIS) technology allows public health practitioners to explore disparities in health, analyze disease outbreaks, and prioritize the use of limited resources for improving population health. Nursing students benefit from use of World Wide Web GIS resources as they develop knowledge and skill in assessing population health and planning interventions. This article identifies the benefits of GIS for public health practitioners, presents a communicable disease control application of GIS, and discusses a GIS module used in an undergraduate nursing education course. Uniform standards for making health data available for public use with GIS are discussed.

Notes: Abstract  The purpose of this study was to compare health-promoting practices of Canadian (n = 49) and Jordanian (n = 44) first-year nursing students using the revised Health-Promoting Lifestyle Profile II. Results indicated significant differences between the groups on three subscales: health responsibility, physical activity, and interpersonal relations; however, both groups had similarly low scores. Implications for nurse educators are discussed from both curricular and cross-cultural perspective that focuses on health-promotion activities and programs.

Notes: The reintroduction of Sphagnum fragments has been found to be a promising method for restoring mire vegetation in a cutaway peatland. Although it is known that moisture controls Sphagnum photosynthesis, information concerning the sensitivity of carbon dynamics on water-level variation is still scarce. In a 4-year field experiment, we studied the carbon dynamics of reintroduced Sphagnum angustifolium material in a restored (rewetted) cutaway peatland. Cutaway peatland restored by Sphagnum reintroduction showed high sensitivity to variation in water level. Water level controlled both photosynthesis and respiration. Gross photosynthesis (PG) had a unimodal response to water-level variation with optimum level at −12 cm. The range of water level for high PG (above 60% of the maximum light-saturated PG) was between 22 and 1 cm below soil surface. Water level had a dual effect on total respiration. When the water level was below soil surface, peat respiration increased rapidly along the lowering water level until the respiration rate started to slow down at approximately −30 cm. Contrary to peat respiration, the response of Sphagnum respiration to water-level variation resembled that of photosynthesis with an optimum at −12 cm. In optimal conditions, Sphagnum reintroduction turned the cutaway site from carbon source to a sink of 23 g C/m2 per season (mid-May to the end of September). In dry conditions, lowered photosynthesis together with the higher peat respiration led to a net loss of 56 g C/m2. Although the water level above the optimum amplitude restricted CO2 fixation, a decrease in peat respiration led to a positive CO2 balance of 9 g C/m2.

Notes: Restoration status of forest rehabilitation areas can be assessed by comparing their ecosystem characteristics with those of a reference system, most often what is considered the natural climax vegetation. However, comprehensive measurements needed for a traditional vegetation description are often hard or impractical in complex (sub)tropical ecosystems. Therefore, an alternative approach is the identification of simple indicators of ecosystem integrity. The use of such indicators can speed up the availability of resource inventories and thus contribute to the accelerated implementation of successful rehabilitation practices. Thermal buffer capacity (TBC) of ecosystems has been previously proposed as an overall indicator of ecosystem integrity. In this article, sequential surface-temperature measurements are proposed as a method for TBC assessment of different land-use types. Surface temperatures of seven land units in central Tigray (northern Ethiopia), each with a uniform land-use type (degraded and bushy grazing land, enriched and non-enriched rehabilitation area, and forest), were measured with a hand-held infrared thermometer in the rainy and the dry season. Surface-temperature models were derived by means of quadratic regression. Cross-correlation functions were calculated for all possible pairs of land-unit time-series data. Instantaneous heat-up rates, average TBC, and accumulated heat load were calculated. Repeated-measures analysis of variance was used to test the effect of aspect and protection status on TBC. Kruskal–Wallis one-way analysis of variance by ranks for small samples was used to test the significance of differences in heat-up rates and heat load among land-use groups. Time lags between land-unit surface temperatures are caused by differences in aspect rather than land-use type. Protection status and aspect have a significant effect on the average TBC. Results clearly demonstrate a differentiation between protected (low heat-up rate) and non-protected areas (high heat-up rate). Overall ranking suggests that the remnant forest has the highest TBC of all surveyed land-use types, followed by the enriched protected area. Results of this study show that TBC quickly responds to area closure and can therefore be used to monitor the development of protected areas. It is strongly recommended that a detailed monitoring strategy for protected areas on the basis of this technology be devised, validated, and finally transferred to the local communities.

Notes: An ecological functional assessment (EFA) was used on 10 southwest Costa Rica sites representing a chronosequence of formerly pastured lands to undisturbed tropical wet forest. Ecological functional assessment is a tool designed to assess wetland functions in the United States that was adapted to upland forests. Models to indicate characteristic soil hydrologic features and soil structure and aboveground spatial structure of habitat were used to examine the degree to which selected sites within the chronosequence approach the undisturbed condition of the natural forest. An index of the functional model for the maintenance of characteristic soil hydrologic features (such as infiltration, bulk density, etc.) showed that the 20-year-old secondary forest was at approximately 60% of the condition of the undisturbed sites, whereas active pasture was evaluated at approximately 20% of the reference undisturbed forest; 4- and 10-year-old sites were intermediate. The spatial structure of habitat model showed that 20-year-old secondary forest was approximately 50% of reference forest, whereas active pasture was approximately 10% of the condition of undisturbed forest; 4-year-old sites were evaluated at approximately 20% and 10-year-old sites at approximately 60% of the reference state. Overall the functional assessment process indicated that degraded tropical wet forest sites have recovered almost 60% of their functional qualities 10 years following pasture abandonment. These results indicate that EFA can be a useful technique for monitoring restoration programs in the tropics.

Notes: We evaluated changes in ecosystem function in semiarid Stipa tenacissima L. steppes along a degradation gradient in southeast Spain. We used soil surface indicators to obtain surrogates of ecosystem function (resistance to erosion, infiltration, and nutrient cycling) and related these values to the main abiotic and biotic characteristics of the experimental sites. When ranked in an ordered sequence, the trajectory of these indicators showed abrupt changes, providing empirical evidence of discontinuities in ecosystem function along the degradation gradient evaluated. Surrogates of resistance to erosion showed nonlinear relationships with variables defining the spatial structure of patches, the area covered by sprouting shrubs, and species richness. The latter two variables were significantly related to surrogates of nutrient cycling and infiltration. Our results suggest that sprouting shrubs are playing a key role in improving ecosystem function and composition in degraded S. tenacissima steppes. The implications of our results for the optimization of restoration procedures in semiarid degraded steppes are discussed.

Notes: Restoration of salt marsh ecosystems is an important concern in the eastern United States to mitigate damage caused by industrial development. Little attention has been directed to the mycorrhizal influence on plantings of salt marsh species to stabilize estuarine sediments and establish cover. In our study, seedlings of two salt marsh grasses, Spartina alterniflora and Spartina cynosuroides, were grown in soil with a commercial, mixed species inoculum of arbuscular mycorrhizal fungi. Plants were grown in experimental “ebb and flow” boxes, simulating three levels of tidal inundation, to which two levels of applied phosphorus (P) and two levels of salinity were imposed. After 2.5 months, S. alterniflora was poorly colonized by arbuscular mycorrhizae, developing only fungal hyphae and no arbuscules, but S. cynosuroides became moderately colonized. Mycorrhizal inoculation marginally improved growth and P and nitrogen (N) content of both plant species at low levels of P supply but significantly increased tillering in both plant species. This factor could be beneficial in enhancing ground cover during restoration procedures. Greater P availability increased the mycorrhizal status of S. cynosuroides and improved P nutrition of both plant species, despite a reduction in the root-to-shoot ratio. Increasing salinity reduced mycorrhizal colonization of S. alterniflora but not of S. cynosuroides. Growth and nutrient content of S. alterniflora was improved at higher levels of salinity, but only increased nutrient content in S. cynosuroides. Increased duration of tidal inundation decreased plant growth in both species, but tissue P and N concentrations were highest with the longest time of inundation in both species.

Notes: As monitoring plans for the restoration of Pinus ponderosa forests in the southwestern United States evolve toward examining multifactor ecosystem responses to ecological restoration, designing efficient sampling procedures for understory vegetation will become increasingly important. The objective of this study was to compare understory composition and diversity among thin/burn and control treatments in a P. ponderosa restoration, while simultaneously examining the effects of sampling design and multivariate analyses on which conclusions were based. Using multi-response permutation procedures (MRPP), we tested the null hypothesis of no difference in understory species composition among treatments using different data matrices (e.g., frequency and cover) for two different sampling methods. Treatment differences were subtle and were detected by an intensive 50, 1-m2 subplot sampling method for all data matrices but were not detected by a less intensive point-intercept sampling method for any matrix. Sampling methods examined in this study controlled results of multivariate analyses more than the data matrices used to summarize data generated by a sampling method. We partitioned data into plant life form and native/exotic species categories for MRPP, and this partitioning isolated plant groups most responsible for treatment differences. We also examined the effects of number of 1-m2 subplots sampled on mean-species-richness/m2 estimates and found that estimates based on 10 subplots and based on 50 subplots were highly correlated (r = 0.99). Species–area curves indicated that the 50, 1-m2 subplot sampling method detected the common species of sites but failed to detect the majority of rare species. Additional sampling-design studies are needed to develop single sampling designs that produce multifactor data on plant composition, diversity, and spatial patterns amenable to multivariate analyses as part of monitoring plans of vegetation responses to ecological restoration.

Notes: The relative abundances of Chenopodiaceae shrubs are different from the seed composition in the original seed mix when sown on mine waste material in semiarid regions of Western Australia. Experiments were therefore undertaken to determine what species interactions are responsible for shifts in relative abundance after seeding. The growth parameters of five members of the Chenopodiaceae were used to determine intra- and interspecific density-dependent interactions. Dominant and subordinant species were paired and grown in pots at differing densities. The growth parameters measured were height, root, and shoot biomass. Of the five species chosen for this study, Maireana georgei (golden bluebush) and Enchylaena tomentosa (ruby saltbush) do not establish well on mine site areas. These were sensitive to density in monoculture, as well as in the presence of both Atriplex bunburyana (silver saltbush) and Atriplex codonocarpa (flat-topped saltbush). Although Maireana brevifolia (small leaf bluebush) does establish successfully on mine sites when sown, it showed the same negative reaction when grown in monoculture and in a two-species mixture. Atriplex bunburyana and A. codonocarpa, in contrast, are dominant species and reacted differently when grown with increasing numbers of the target species (M. georgei, M. brevifolia, and E. tomentosa). Atriplex bunburyana did not exhibit any decreases in growth when grown in competition with up to four plants of the target species. However, A. codonocarpa did react adversely to the presence of the target species. It is thought that the resulting plant community organization reflects the original seed mixture, which is usually sown at a high density. Yet, this study has shown that the differing intra- and interspecific density responses of these chenopod species provide an indication of the resulting community organization. To maximize diversity and to prevent dominance by highly competitive species, such as A. bunburyana, it is important to take density-dependent effects into account during the restoration planning stage.

Notes: Plant species richness in rural landscapes of northern Europe has been positively influenced by traditional management for millennia. Owing to abandonment of these practices, the number of species-rich semi-natural grasslands has decreased, and remaining habitats suffer from deterioration, fragmentation, and plant species decline. To prevent further extinctions, restoration efforts have increased during the last decades, by reintroducing grazing in former semi-natural grasslands. To assess the ecological factors that might influence the outcome of such restorations, we made a survey of semi-natural grasslands in Sweden that have been restored during the last decade. We investigated how plant species richness, species density, species composition, and abundance of 10 species that are indicators of grazing are affected by (1) the size of the restored site, (2) the time between abandonment of grazing and restoration, (3) the time elapsed since restoration, and (4) the abundance of trees and shrubs at the restored site. Only two factors, abundance of trees and shrubs and time since restoration, were positively associated with total species richness and species density per meter square at restored sites. Variation in species composition among restored sites was not related to any of the investigated factors. Species composition was relatively similar among sites, except in mesic/wet grasslands. The investigated factors had small effects on the abundance of the grazing-indicator species. Only Campanula rotundifolia responded to restoration with increasing abundance and may thus be a suitable indicator of improved habitat quality. In conclusion, positive effects on species richness may appear relatively soon after restoration, but rare, short-lived species are still absent. Therefore, remnant populations in surrounding areas may be important in fully recreating former species richness and composition.

Notes: Ground and pelletized Wollastonite (Wo; CaSiO3) was added to a 50-m reach of an anthropogenically acidified stream within the Hubbard Brook Experimental Forest, New Hampshire, to evaluate its buffering and restoration potential. The Wo was highly effective in raising the pH, acid-neutralizing capacity (ANC), dissolved inorganic carbon (DIC), and Ca2+ concentrations of the stream water, but during the short duration of the experiment had no discernable effect on the stream biota. After initial, spike-like fluctuations in pH and concentrations of ANC, DIC, and Ca2+, the relatively slow dissolution rates of the Wo dampened extreme concentrations and contributed to relatively long-lasting (4 months) amelioration of streamwater acidity. Changes in concentrations of Ca2+, dissolved Si, ANC, and DIC were inversely related to streamflow. After several high, stream-discharge events, concentrations quickly and consistently returned to pre-event conditions.

Notes: The potential of Cephalophyllum inaequale was investigated for use in initiating ecosystem restoration in degraded landscapes of Namaqualand, South Africa. Cephalophyllum inaequale, a perennial shrub, is a member of the succulent Mesembryanthemaceae family, typical of the Succulent Karoo Biome and in particular of the Namaqualand area. A bioclimatic envelope was modeled to establish the area in which this species might feasibly be used. The regional bioclimatic potential for C. inaequale proved to be extensive, covering approximately 17,500 km2. An examination of the functional role of C. inaequale showed it to facilitate early seedling survival in this community. A nearest-neighbor study found no evidence of interspecific competition between C. inaequale and its dominant co-occurring species, possibly due to vertical stratification of rooting structures. Cephalophyllum inaequale significantly reduced wind speed and soil erosion. Experiments to test the feasibility of propagating, reintroducing, and establishing this species showed that it easily germinates from seed, and transplanted cuttings have a high survival rate. This study demonstrates that C. inaequale has potential for use in initiating the restoration of degraded lands in South Africa.

Notes: The cloud forests of Mexico have been degraded and severely fragmented, and urgently require restoration. However, progress with restoration has been constrained by a lack of information concerning the seedling ecology of native tree species. An experiment was therefore conducted to assess the influence of different environmental factors on the seedling survival and growth of four native tree species (Fagus grandifolia var. mexicana, Carpinus caroliniana, Symplocos coccinea, and Quercus acutifolia). The seedlings were established on three sites, in two contrasting environments: inside forest fragments and on adjacent agricultural land. Highly significant differences were recorded in seedling survival and growth among sites, environments, species, and interactions between these factors. Highest survival was recorded for Quercus, which uniquely among the four species displayed the same survival percentage inside and outside the forest. Survival of the other species was higher inside the forest. In contrast, growth rates of all four species were higher outside the forest. The most important cause of mortality outside the forest was desiccation, although significant seedling predation was also observed on two sites. Results indicate that all four species can be established successfully both within forest fragments and in neighboring agricultural areas, emphasizing the scope for forest restoration. However, the interactions observed between species, sites, and environments highlight the importance of accurate species–site matching if optimum rates of growth and survival are to be obtained. Quercus spp. have great potential for establishment on agricultural sites.

Notes: The mature oak (Quercus liaotungensis Koidz) forests in the Dongling mountains of northern China have become degraded in recent years because regeneration has been limited. To determine whether or not seedling establishment of the oak is seed limited, microsite limited, or predator limited and to determine whether seedling establishment is affected by ground cover, we conducted field experiments during a mast year and investigated the fate of seeds and the soil seed bank dynamics of the oak. A large acorn crop (128.8 acorns/m2) was observed in the study period, and the peak density of acorns on the forest floor reached 46.5 acorns/m2, suggesting that tree recruitment was not seed limited. Acorns in the soil seed bank were mainly lost through decay (principally after fungal attack), consumption in situ, and removal by animals. Predation (including consumption in situ and removal) accounted for 86.4% of acorn loss and was therefore likely to have been the most important factor influencing seed dynamics. More than 70% of acorns were found to have germinated, but no established seedling was observed on the forest floor. Using cages to exclude predators, it was estimated that 87% of acorns germinated and 49% became established as seedlings, indicating that the acorns on the forest floor could emerge and grow in the absence of predators. We conclude that the regeneration of the tree population is limited by predators rather than by the availability of microsites. The presence of ground cover increased the germination rate and increased the chance of seed survival in the early stage of the experiment, but at the end of the investigation, no established seedling was found in the quadrats both with and without ground cover, possibly because of high density of animal predators. On the basis of these results, we suggest that selective tree felling will increase the coverage of the herbaceous layer, which can further decrease the population density of the rodents, and thereby improve the regeneration of oak trees.

Notes: Reach-scale stream restorations are becoming a common approach to repair degraded streams, but the effectiveness of these projects is rarely evaluated or reported. We surveyed governmental, private, and nonprofit organizations in the state of Indiana to determine the frequency and nature of reach-scale stream restorations in this midwestern U.S. state. For 10 attempted restorations in Indiana, questionnaires and on-site assessments were used to better evaluate current designs for restoring stream ecosystems. At each restoration site, habitat and water quality were evaluated in restored and unrestored reaches. Our surveys identified commonalities across all restorations, including the type of restoration, project goals, structures installed, and level of monitoring conducted. In general, most restorations were described as stream-relocation projects that combined riparian and in-stream enhancements. Fewer than half of the restorations conducted pre- or post-restoration monitoring, and most monitoring involved evaluations of riparian vegetation rather than aquatic variables. On-site assessments revealed that restored reaches had significantly lower stream widths and greater depths than did upstream unrestored reaches, but riparian canopy cover often was lower in restored than in unrestored reaches. This study provides basic information on midwestern restoration strategies, which is needed to identify strengths and weaknesses in current practices and to better inform future stream restorations.

Notes: Abstract We examined the 7-year effects of three restoration treatments on leaf physiology and insect-resistance characteristics of pre-settlement age ponderosa pines (Pinus ponderosa Dougl. ex Laws.) at the Gus Pearson Natural Area (GPNA) in northern Arizona. Restoration treatments were: (1) thinned in 1993 to approximate pre-Euro-American settlement stand structure, (2) thinned plus prescribed burned in 1994 and 1998, and (3) untreated control. Tree physiological and insect-resistance characteristics were measured in year 2000, 7 years after thinning, using the same procedures as an earlier study performed in 1996. Consistent with the 1996 results, pre-dawn water potential in 2000 was consistently lower in the control than both thinned treatments. Both thinned treatments continued to have increased foliar nitrogen concentration in leaves 7 years after treatment. However lower leaf nitrogen concentration in the thinned and burned compared with the thinned treatment suggests lower nitrogen availability to trees in repeatedly burned plots. Analysis of leaf gas exchange characteristics and carbon isotope content (δ13C) suggests continued stimulation of photosynthesis by both thinning treatments. Differences among treatments in resin volume, a measure of bark beetle resistance, depended on season of measurement. Trees in both thinning treatments continued to have increased leaf toughness, a measure of resistance to insect folivores. Our results show that many beneficial effects of restoration treatments on carbon, water, and nitrogen relations and insect-resistance characteristics of pre-settlement ponderosa pines continue to be expressed 7 years after treatment at the GPNA.

Notes: Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683–2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995–1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion-control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water-absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth.

Notes: We compared four types of 30-year-old forest stands growing on spoil of opencast oil shale mines in Estonia. The stand types were: (1) natural stands formed by spontaneous succession, and plantations of (2) Pinus sylvestris (Scots pine), (3) Betula pendula (silver birch), and (4) Alnus glutinosa (European black alder). In all stands we measured properties of the tree layer (species richness, stand density, and volume of growing stock), understory (density and species richness of shrubs and tree saplings), and ground vegetation (aboveground biomass, species richness, and species diversity). The tree layer was most diverse though sparse in the natural stands. Understory species richness per 100-m2 plot was highest in the natural stand, but total stand richness was equal in the natural and alder stands, which were higher than the birch and pine stands. The understory sapling density was lower than 50 saplings/100 m2 in the plantations, while it varied between 50 and 180 saplings/100 m2 in the natural stands. Growing stock volume was the least in natural stands and greatest in birch stands. The aboveground biomass of ground vegetation was highest in alder stands and lowest in the pine stands. We can conclude that spontaneous succession promotes establishment of diverse vegetation. In plantations the establishment of diverse ground vegetation depends on planted tree species.

Notes: This study examined factors affecting germination, survival, and growth of the grass trees Xanthorrhoea gracilis and X. preissii on newly rehabilitated bauxite mine pits in the jarrah forest of southwestern Australia. Grazing by kangaroos (Macropus fuliginosus) was the major factor in reducing survival and growth of both species during the first 2 years. Provision of artificial grazing protection increased survival and growth (plant mass) of both species by 3-fold. Grazing by native vertebrates has not previously been identified as affecting mine restoration in Western Australia. Initial germination rates from sown seeds of X. preissii at eight replicate sites ranged from 25 to 64% with a mean of 42%. Corresponding figures for X. gracilis were 5–42% with a mean of 17%. Germination of X. gracilis was greater on heavier, moister soils, but X. preissii germinated better on sandier soils. High levels of initial germination did not ensure high survival. Plants of both species grew bigger and survived better on the lighter, sandy soils. Xanthorrhoea seedlings located in the depressions created by the ripping process grew larger than seedlings on the slopes of the riplines. The presence of plants of other species did not have a significant effect on survival. However, these plants facilitated the growth of both species when artificial grazing protection was unavailable. Plants of other species reduced the growth rates of Xanthorrhoea seedlings where artificial grazing protection was provided. Artificial shade by itself had no significant effect on growth of either species. In rehabilitated bauxite mines in the jarrah forest, the provision of grazing protection is recommended to ensure successful establishment and early survival of Xanthorrhoea spp.

Notes: To assess the potential for enhancing an existing stand of native perennial grasses on a California Coast Range Grassland site, we experimentally manipulated the seasonal timing and presence of grazing for 3 years (1994 through 1996) and of autumn burning for 2 years (1994 and 1995) and measured species cover for 6 years (1993 through 1998). We subjected the species matrix to classification (TWINSPAN) and ordination (CCA) and tested the ordination site scores as well as diversity indices with linear mixed effects models. Four distinct plant community groups emerged from the classification. Two of these were dominated by annual grasses and two by perennial grasses. No treatment effects were observed on diversity. For composition, temporal and spatial random effects were important mixed effects model parameters, as was the fixed effect covariate, pre-treatment CCA site score, indicating the importance of random environmental variation and initial starting conditions. Incorporation of these random effects and initial condition terms made for more powerful tests of the fixed effects, grazing season, and burning. We found no significant burning effects. Grazing removal imparted a shift in plant community from more annual-dominated toward more perennial-dominated vegetation. Individual perennial grass species responded differently according to genus and species. Nassella spp. increased gradually over time regardless of grazing treatment. Nassella pulchra (purple needlegrass) increase was greatest under spring grazing and N. lepida (foothill needlegrass) was greatest with grazing removal. Danthonia californica (California oatgrass) had little response over time under seasonal grazing treatments, but increased with grazing removal. Under relatively mesic weather conditions it appears that grazing removal from Coast Range Grasslands with existing native perennial grass populations can increase their cover. However if N. pulchra is the sole existing population, spring season-restricted grazing should be equally effective at enhancing cover of the native grass species.

Notes: A combination of air-photo interpretation, field data, and Geographic Information System (GIS) analysis was used to map riparian areas that are likely to provide wood and shade to small- and medium-sized streams and where, conversely, restoration might be most beneficial. The analysis encompassed all salmonid-bearing waters of the Nooksack River basin, in northwest Washington State, plus small tributaries that were thought to contribute wood or effective shading. The size and composition of each riparian stand was examined to determine whether trees were large enough to contribute logs that would form pools in the adjacent channel, with pool-forming size of wood a function of channel width. Riparian stands were classified according to whether they passed this pool-forming test. Model results were an exact match to actual conditions in 69% of field-verified stands. A large proportion (74%) of the stands failing the test in reaches of anadromous fish use were in agricultural areas. Passing stands typically had high shade levels, because both stream shade and effective large woody debris size are a function of the size of the trees relative to the size of the stream. The GIS layer of passing and failing riparian stands can be combined with layers depicting property ownership, threatened fish distribution, and other information to objectively prioritize riparian restoration locations and strategies.

Notes: The benefits of wetlands are now widely appreciated. Less widely known is that historically many wetlands were drained to help control malaria and other deadly diseases. This essay's general theme is that there are pros and cons to restoration or creation of wetlands. The specific theme is that mosquitoes pose practical and theoretical problems. In particular, abundant mosquitoes should not be regarded as an after-the-fact surprising side effect but rather, abundant mosquitoes should be viewed as a primary and foreseeable effect of providing habitat suitable for them. Yet our funding mechanisms and educational institutions often fail properly to address the reality that restoring or creating wetlands has a downside.

Notes: The recruitment of native seedlings is often reduced in areas where the invasive Amur honeysuckle (Lonicera maackii) is abundant. To address this recruitment problem, we evaluated the effectiveness of L. maackii eradication methods and restoration efforts using seedlings of six native tree species planted within eradication and unmanipulated (control) plots. Two eradication methods using glyphosate herbicide were evaluated: cut and paint and stem injection with an EZ-Ject lance. Lonicera maackii density and biomass as well as microenvironmental characteristics were measured to study their effects on seedling growth and survivorship. Mean biomass of Amur honeysuckle was 361 ± 69 kg/ha, and density was 21,380 ± 3,171 plants/ha. Both eradication treatments were effective in killing L. maackii (≥ 94%). The injection treatment was most effective on large L. maackii individuals (〉1.5 cm diameter), was 43% faster to apply than cutting and painting and less fatiguing for the operator, decreased operator exposure to herbicide, and minimized impact to nontarget vegetation. Deer browse tree protectors were used on half of the seedlings, but did not affect survivorship or growth. After 3 years, survival of native seedlings was significantly less where L. maackii was left intact (32 ± 3%) compared with the eradication plots (p 〈 0.002). Seedling survival was significantly different between cut (51 ± 3%) and injected (45 ± 3%) plots. Species had different final percent survival and rates of mortality. Species survival differed greatly by species (in descending order): Fraxinus pennsylvanica 〉 Quercus muehlenbergii ≥ Prunus serotina≥ Juglans nigra 〉 Cercis canadensis 〉 Cornus florida. Survivorship and growth of native seedlings was affected by a severe first-year drought and by site location. One site exhibited greater spring soil moisture, pH, percent open canopy, and had greater survivorship relative to the other site (55 ± 2 vs. 30 ± 2%). Overall, both L. maackii eradication methods were successful, but restorationists should be aware of the potential for differential survivorship of native seedlings depending on species identity and microenvironmental conditions.

Notes: Several eastern states are considering the restoration of free-ranging elk populations via translocation from western populations. Optimal habitat immediately surrounding release sites has been found to enhance elk reintroduction success in western states. Little information exists, however, to aid eastern managers in identifying release sites with the highest chance of restoration success. We monitored the movements of 415 translocated elk released at three sites in southeastern Kentucky to identify landscape characteristics that enhance release-site fidelity. The distance elk moved after release differed among sites (F2,322 = 4.63, p = 0.01), age classes (F2,322 = 4.37, p = 0.01), and time intervals (F2,322 = 40.74, p 〈 0.001). At 6 and 12 months post-release, adults (15.81 ± 17.32 and 16.38 ± 20.29) and yearlings (13.91 ± 16.44 and 14.61 ± 21.11) moved farther than calves (8.06 ± 14.03 and 9.37 ± 14.40). The release site with the highest fidelity was privately owned, 15% open, and had the highest amount of edge compared with the other release sites. The two remaining sites contained large amounts of expansive openland or forest cover with lower amounts of edge. Additionally, both sites were publicly owned and experienced a higher degree of human-generated disturbance compared with the site to which elk were most faithful. When selecting release sites, managers should avoid areas dominated by a single cover type with little interspersion of other habitats. Rather, areas with high levels of open-forest edge (approximately 5.0 km/km2) and limited-human disturbance will likely enhance release-site fidelity and promote restoration success.

Notes: Limestone quarries are spread over the Mediterranean Basin and have a strong environmental impact on the landscape, causing vegetation losses and soil losses. A reclamation project was conducted in a limestone quarry, situated in Arrábida Natural Park (southwest Portugal), that is dominated by mediterranean vegetation. Revegetation was conducted using three evergreen sclerophyllous shrub species (Ceratonia siliqua, Olea europaea, and Pistacia lentiscus), and new techniques were assayed to improve plant water status and nutrient status during the first phases after plantation. A water-holding polymer (gel), fertilizer, and mycorrhiza inoculum were applied in a factorial experiment in a randomized complete block design. The success of these techniques was evaluated during 1.5 years, through monitoring of growth and ecophysiology of plants. Plant survival was high, the lowest values (95%) being recorded in C. siliqua. There were species-specific responses to the treatments applied. Ceratonia siliqua showed the highest growth rates and was the only species with growth stimulated by fertilizer application. However, the application of fertilizer induced changes in leaf characteristics of the other two species, increasing chlorophyll and nitrogen contents. Mycorrhiza inoculum had no effect on plant response. The addition of the water-holding polymer induced higher midday plant water potentials in C. siliqua, O. europaea, and P. lentiscus, but in the latter two species the simultaneous addition of gel and fertilizer induced the lowest water potentials. The addition of fertilizer and gel is recommended in future revegetation programs but not the combination of both when revegetating with O. europaea and P. lentiscus. The results of this experiment indicate that the use of these mediterranean species, adapted to nutrient and water stress, can circumvent harsh conditions of the quarry.

Notes: Structural attributes of the C4, perennial bunchgrass Schizachyrium scoparium in restored prairies may be affected by the time since restoration. One hundred plants each in 8-, 17-, and 23-year-old restored prairies and a native Texas Blackland prairie were assessed for the presence/absence and diameter of a hollow crown (i.e., dead center portion), degree of fragmentation, plant height, and tiller density. Structural attributes of S. scoparium plants were generally (1) different between recent (8 years) and older (17 and 23 years) restored prairies (2) similar between the 17- and 23-year-old restored prairies, and (3) more similar between the 8- and 17-year restored prairies and the native, remnant prairie than between the 23-year restored prairie and the native prairie. Plants were shorter in restored prairies, regardless of time since restoration, than in the native prairie. Mean basal area of plants was 80–163% greater in the 17- and 23-year restored prairies compared with the native and 8-year restored prairies. Percentage of hollow crowns and fragmentation was smallest in the 8-year restored prairie, largest in the 17- and 23-year restored prairies, and intermediate in the native prairie. Tiller density exhibited inverse second-order polynomial decreases with increasing plant basal area for all prairies. In contrast to tiller density, diameter of hollow crowns increased logarithmically with increasing plant basal area. Structural attributes of S. scoparium in restored prairies changed predictably with age, despite growing in different communities.

Notes: There is growing interest in the addition of carbon (C) as sucrose or sawdust to the soil as a tool to reduce plant-available nitrogen (N) and alter competitive interactions among species. The hypothesis that C addition changes N availability and thereby changes competitive dynamics between natives and exotics was tested in a California grassland that had experienced N enrichment. Sawdust (1.2 kg/m) was added to plots containing various combinations of three native perennial bunchgrasses, exotic perennial grasses, and exotic annual grasses. Sawdust addition resulted in higher microbial biomass N, lower rates of net N mineralization and net nitrification, and higher concentrations of extractable soil ammonium in the soil. In the first year sawdust addition decreased the degree to which exotic annuals competitively suppressed the seedlings of Nassella pulchra and, to a lesser extent, Festuca rubra, both native grasses. However there was no evidence of reduced growth of exotic grasses in sawdust-amended plots. Sawdust addition did not influence interactions between the natives and exotic perennial grasses. In the second year, however, sawdust addition did not affect the interactions between the natives and either group of exotic grasses. In fact, the native perennial grasses that survived the first year of competition with annual grasses significantly reduced the aboveground productivity of annual grasses even without sawdust addition. These results suggest that the addition of sawdust as a tool in the restoration of native species in our system provided no significant benefit to natives over a 2-year period.

Notes: Concepts and models from complex systems theory are introduced to help expand the approaches to quantify restoration success in ecology. Main points are illustrated using case studies. These include (1) recovery and restoration trajectories may be complex (nonlinear, unpredictable, and leading to multiple attractors), and thus knowledge of well-known model trajectories from complex systems theory may be useful; (2) modeling may be inevitable, as complete and long-term observation of recovery pathways are rarely possible; (3) holistic views (e.g., community level as opposed to population-level) may be necessary to understand governing processes in restoration and recovery.

Notes: Recent efforts to clear invasive plants from the fynbos of South Africa forces managers to think about how N2-fixing invasives have altered ecosystem processes and the implications of these changes for community development. This study investigated the changes in nitrogen (N) cycling regimes in fynbos with the invasion of Acacia saligna, the effects of clear-cutting acacia stands on soil microclimate and N cycling, and how altered N resources affected the growth of a weedy grass species. Litterfall, litter quality, soil nutrient pools, and ion exchange resin (IER)-available soil N were measured in uninvaded fynbos, intact acacia, and cleared acacia stands. In addition, a bioassay experiment was used to ascertain whether the changes in soil nutrient availability associated with acacia would enhance the success of a weedy grass species. Acacia plots had greater amounts of litterfall, which had higher concentrations of N. This led to larger quantities of organic matter, total N, and IER-available N in the soil. Clearing acacia stands caused changes in soil moisture and temperature, but did not result in differences in IER-available N. The alteration of N availability by acacias was shown to increase growth rates of the weedy grass Ehrharta calycina, suggesting that secondary invasions by nitrophilous weedy species may occur after clearing N2-fixing alien species in the fynbos. It is suggested that managers use controlled burns, the addition of mulch, and the addition of fynbos seed after clearing to lower the levels of available N in the soil and initiate the return of native vegetation.

Notes: Ponderosa pine forest restoration consists of thinning trees and reintroducing prescribed fire to reduce unnaturally high tree densities and fuel loads to restore ecosystem structure and function. A current issue in ponderosa pine restoration is what to do with the large quantity of slash that is created from thinning dense forest stands. Slash piling burning is currently the preferred method of slash removal because it allows land managers to burn large quantities of slash in a more controlled environment in comparison with broadcast burning slash. However burning slash piles is known to have adverse effects such as soil sterilization and exotic species establishment. This study investigated the effects of slash pile burning on soil biotic and chemical variables and early herbaceous succession on burned slash pile areas. Slash piles were created following tree thinning in two adjacent approximately 20-ha ponderosa pine (Pinus ponderosa) restoration treatments in the Coconino National Forest near Flagstaff, Arizona. We selected 30 burned slash pile areas and sampled across a gradient of the burned piles for arbuscular mycorrhizal (AM) propagule densities, the soil seed bank, and soil chemical properties. In addition, we established five 1-m2 plots in each burned pile to quantify the effect of living soil (AM inoculum) and seeding amendments on early herbaceous succession in burned slash pile areas. The five treatments consisted of a control (no treatment), living soil (AM inoculum) amendment, sterilized soil (no AM inoculum) amendment, seed amendment, and a seed/soil (AM inoculum) amendment. Slash pile burning nearly eliminated populations of viable seeds and AM propagules and altered soil chemical properties. Amending scars with native seeds increased the cover of native forbs and grasses. Furthermore adding both seed and living soil more than doubled total native plant cover and decreased ruderal and exotic plant cover. These results indicate that seed/soil amendments that increase native forbs and grasses may enhance the rate of succession in burned slash pile areas by allowing these species to outcompete exotic and ruderal species also establishing at the site through natural regeneration.

Notes: The development of selective ligands targeting neuronal nicotinic acetylcholine receptors to alleviate symptoms associated with neurodegenerative diseases presents the advantage of affecting multiple deficits that are the hallmarks of these pathologies. TC-1734 is an orally active novel neuronal nicotinic agonist with high selectivity for neuronal nicotinic receptors. Microdialysis studies indicate that TC-1734 enhances the release of acetylcholine from the cortex. TC-1734, by either acute or repeated administration, exhibits memory enhancing properties in rats and mice and is neuroprotective following excitotoxic insult in fetal rat brain in cultures and against alterations of synaptic transmission induced by deprivation of glucose and oxygen in hippocampal slices. At submaximal doses, TC-1734 produced additive cognitive effects when used in combination with tacrine or donepezil. Unlike (-)-nicotine, behavioral sensitization does not develop following repeated administration of TC-1734. Its pharmacokinetic (PK) profile (half-life of 2 h) contrasts with the long lasting improvement in working memory (18 h) demonstrating that cognitive improvement extends beyond the lifetime of the compound. The very low acute toxicity of TC-1734 and its receptor activity profile provides additional mechanistic basis for its suggested potential as a clinical candidate. TC-1734 was very well tolerated in acute and chronic oral toxicity studies in mice, rats and dogs. Phase I clinical trials demonstrated TC-1734's favorable pharmacokinetic and safety profile by acute oral administration at doses ranging from 2 to 320 mg.The bioavailability, pharmacological, pharmacokinetic, and safety profile of TC-1734 provides an example of a safe, potent and efficacious neuronal nicotinic modulator that holds promise for the management of the hallmark symptomatologies observed in dementia.

Notes: ABT-089 [2-methyl-3-(2-(S)-pyrrolidinylmethoxy)pyridine dihydrochloride salt] is a selective neuronal nicotinic receptor (NNR) modulator with cognitive enhancing properties in animal models of cognitive functioning. Amongst NNR subtypes, ABT-089 shows selectivity for the cytisine binding site on the α4β2 receptor subtype as compared to the α-bungarotoxin (α-BgT) binding sites on the α7 and α1β1δγ receptor subtypes. In functional in vitro electrophysiological and cation flux assays, ABT-089 displays differential activity including agonism, partial agonism and antagonism depending upon the NNR subtype and assay. ABT-089 is as potent and efficacious as (–)-nicotine at evoking acetylcholine (ACh) release from hippocampal synaptosomes. Furthermore, ABT-089 is neuroprotective against excitotoxic glutamate insults, with even greater potency seen after chronic treatment. Similarly, ABT-089 is effective in models of cognitive functioning, including enhancement of baseline functioning as well as improvement of impaired cognitive functioning seen following septal lesioning and natural aging. In neuroprotective assays the compound is most potent by chronic administration. In stark contrast to the positive effects in the cognitive models, ABT-089 shows little propensity to induce adverse

Notes: Rimcazole is a carbazole derivative that acts in part as a σ receptor antagonist. Wellcome Research Laboratories introduced this compound during the 1980s when it was hypothesized to be a novel antipsychotic with an improved side effect profile. However, subsequent clinical trials demonstrated that rimcazole lacked efficacy in schizophrenic patients and it is now primarily used as an experimental tool. In addition to its actions as a σ receptor antagonist, rimcazole also has high affinity for dopamine transporters, and in recent years it has served as a lead compound for the development of novel dopamine transporter ligands. Although rimcazole cannot be considered a selective ligand for σ receptors, the recent development of other selective agonists and antagonists for σ receptors have aided in clarifying the involvement of these receptors in the actions of rimcazole. Many of the physiological and behavioral effects of rimcazole can in fact be ascribed to its action as a σ receptor antagonist, although there are exceptions. Rimcazole is likely to have a continued role in elucidating σ receptor function in either in vitro or in vivo systems where σ receptor-mediated effects can be studied independently of the influence of dopamine and serotonin transporters.

Notes: Reboxetine is the first commercially available norepinephrine reuptake inhibitor developed specifically as a first line therapy for major depressive disorder. In vitro and in vivo pharmacological studies indicated that reboxetine methanesulphonate has high affinity and selectivity for the human norepinephrine transporter over the serotonin and dopamine transporters. Pharmacological specificity is further demonstrated by the absence of affinity for 45 transmitter receptors and CNS targets.Pharmacokinetic studies demonstrated that reboxetine is suitable for twice daily administration (8–10 mg/day) and that it exhibits minimal drug-drug interactions. The starting dose of reboxetine should be reduced in the elderly, in patients with renal or hepatic impairment, or in patients receiving potent CYP3A inhibitors. A total of 20 phase II/III clinical studies comprising placebo-controlled, active comparator-controlled and open-label uncontrolled studies in both short-term and long-term treatment of major depression have been conducted. In the treatment of major depression, reboxetine was superior to placebo in 5 of 12 short- or long-term placebo-controlled studies and was comparable in efficacy to active comparators in 3 out of 3 active-controlled studies. Unlike conventional tricyclic antidepressants (TCAs), reboxetine had only minimal sedative and cardiovascular liabilities, probably due to increased pharmacological specificity of reboxetine as compared with TCAs. Unlike serotonin reuptake inhibitors, this selective and specific norepinephrine reuptake inhibitor demonstrated a distinct side-effect profile with diminishing sexual dysfunction and GI side effects. The availability of this agent has afforded patients suffering from major depressive disorder a new class of agents to combat the debilitating consequence of this psychiatric disease. The demonstrated pharmacological specificity of this compound has provided the psychopharmacology community with a tool to elucidate the role of norepinephrine in brain functions. Testing this agent in different animal models has enabled the exploration of the role of modulation of norepinephrine tone in the therapy of CNS disorders beyond depression.

Notes: Chlormethiazole is a thiazole derivative with a long history of use as a sedative agent. The mode of action of the drug has been partly worked out and has been established with recognition that its mechanism of action involves potentiation of GABA activity, the major intrinsic inhibitory neurotransmitter. Animal models of stroke ranging from rodents to primates have suggested an optimistic role for chlormethiazole in preventing both anatomical and functional deleterious effects of stroke. Phase III clinical trials, therefore, proceeded but unfortunately with very little success. Recently, the animal models have been revisited in an attempt to identify causes for this discrepancy between the results from pre-clinical and clinical studies. This review studies the pharmacological roots of chlormethiazole from its origin through to its licensed and novel applications. Emphasis is placed on discussing the animal experiments which led to its grooming as a neuroprotective agent and also on the human trials. The review seeks to explain the discrepancies between animal and human studies, which include short survival times of experimental subjects, speed of drug administration and fundamental differences between species. The primate model of stroke perhaps offers the nearest alternative to phase III trials and has recently been used to compare a number of newer neuroprotective agents with greater efficacy than chlormethiazole. In addition, novel approaches involving human neurochemical analyses in vivo are described which may help bridge the gap between animal models and future phase III trials.

Notes: Several studies have suggested that the antipsychotic compound, cyamemazine, possesses anxiolytic properties in humans. The original pharmacological profile of cyamemazine (D2, 5-HT2A, 5-HT2C, and 5-HT3 receptor antagonist), which was established by binding, microdialysis and behavioral studies, is consistent with these observations. In the light/dark exploration test, cyamemazine demonstrated anxiolytic-like activity by acute, but not chronic administration. By chronic administration, however, cyamemazine increased the time spent in the open arms of the elevated plus maze (EPM) test demonstrating anxiolytic-like activity. The discrepancy between the results obtained in these tests by acute and chronic administration, could be due to a combination of dopamine D2 receptor antagonism with antagonism of the 5-HT2C and 5-HT3 receptors. The action of cyamemazine on both the dopaminergic system and 5-HT3 receptors could also explain the activity of cyamemazine in the management of alcohol withdrawal demonstrated in preclinical studies. This potential indication for cyamemazine and its activity in benzodiazepine withdrawal syndrome have recently been investigated in clinical trials and the results of these studies are presented in this review.

Notes: The functional role of dopamine D1 receptors is still controversial. One reason for this controversy is that for a long time the only available agonists for in vivo characterization of dopamine D1 receptors were benzazepines. Among them was the prototype dopamine D1 receptor partial agonist, SKF 38393. The lack of a selective and fully efficacious dopamine D1 receptor agonist hampered basic research on dopamine D1 receptors and left the potential clinical utility of dopamine D1 receptor agonists elusive. The research situation improved when the first potent full dopamine D1 receptor agonist dihydrexidine, a phenanthridine, was introduced in the late 1980s. In contrast to SKF 38393, dihydrexidine was shown to stimulate cyclic AMP synthesis just as well or better than dopamine, and potently displaced [3H]SCH 23390 from rat and monkey striatal membranes. Also, dihydrexidine was the first dopamine D1 receptor agonist that had potent antiparkinsonian activity in a primate model of Parkinson's disease. This finding suggested clinical utility for dopamine D1 receptor agonists in Parkinson's disease and that this utility might be critically dependent on the intrinsic efficacy of the drug. Clinical utility for dopamine D1 receptor agonists in other central nervous disorders might also be dependent on the intrinsic efficacy of the drug. However, even though studies with dihydrexidine as a pharmacological tool have pointed to the clinical use for dopamine D1 receptor agonists, dihydrexidine's unfavorable pharmacokinetic profile and various adverse effects are likely to restrict or even preclude its use in humans. This review article provides an updated overview of the pharmacology of dihydrexidine and discusses possible clinical utility of dopamine D1 receptor agonists in various central nervous system disorders.

Notes: It is known that thromboxane A2 (TXA2) contributes to various diseases such as bronchial asthma, ischemic heart disease, cerebrovascular disorders and allergic rhinitis. A number of TXA2 synthase inhibitors and TXA2 receptor (TP receptor) antagonists have been developed to treat these diseases. Ramatroban (BAY u 3405) was developed as a potent TP receptor antagonist with excellent efficacy against allergic rhinitis in many animal models and patients. Recent studies also revealed that ramatroban can block the newly identified PGD2 receptor, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTh2). PGD2 induces migration and degranulation of eosinophils through CRTh2 and contributes to late-phase inflammation and cell damage. Accordingly, it was considered that ramatroban suppresses the late-phase inflammation via TP receptor and CRTh2 blockade. In terms of the efficacy on vascular systems, it was revealed that ramatroban can suppress the expression of monocyte chemoattractant protein-1 (MCP-1) and adhesion molecules in endothelial cells and prevent exacerbation of inflammation by blocking these responses. According to our recent studies in hypercholesterolemic rabbits ramatroban prevents macrophage infiltration through MCP-1 downregulation and neointimal formation after balloon injury and attenuates vascular response to acetylcholine. Therefore, ramatroban may be beneficial in the treatment of atherosclerosis.

Notes: Portal hypertension, a life threatening complication of liver cirrhosis, results from increased intrahepatic resistance and increased portal blood inflow through a hyperdynamic splanchnic system. The increased intrahepatic vascular tone is the result of an enhanced activity of endogenous vasoconstrictors and a deficiency of nitric oxide (NO) release by sinusoidal endothelial cells. These pathophysiological events provide the rational basis for using NO-based therapies for the treatment of portal hypertension. Clinical studies have demonstrated that nitrate therapy results in a significant reduction of portal pressure as assessed by hepatic venous portal gradient but causes vasodilation in both systemic arterial and venous vascular beds, aggravating the progression of the vasodilatory syndrome of cirrhotic patients. For this reason, the ideal drug for the treatment of portal hypertension should act by decreasing intrahepatic vascular resistance, without worsening the splanchnic/systemic vasodilatation.NCX-1000 is the prototype of a family of NO-releasing derivatives of ursodeoxycholic acid (UDCA). These compounds are releasing selectively, from parenchymal and non-parenchymal hepatic cells, biologically active NO into the liver microcirculation with no detectable effect on systemic circulation. Preclinical studies have shown that long- and short-term administration of NCX-1000 to rodents with chronic liver injury protects against the development of portal hypertension and reduces the intrahepatic hyperreactivity to α1-adrenoceptor agonists. The finding of increased liver nitrite/nitrate content in NCX-1000-treated animals together with an increase in cGMP levels in their liver homogenates suggests that this nitro-compound behaves as a liver-selective NO donor. In contrast to conventional NO-donors such as isosorbide mono- and di-nitrate, which are also used for primary and secondary prevention of gastrointestinal bleeding, NCX-1000 has no effect on mean arterial pressure in either normal or cirrhotic animals indicating the absence of adverse systemic effect. In summary, these data suggest that NCX-1000 may provide a novel therapy for the treatment of patients with portal hypertension.

Notes: Guinea pigs are useful models to investigate the mechanisms of the hypocholesterolemic effects of drugs. Like humans, guinea pigs are one of the few species that carry the majority of cholesterol in LDL. This animal model has also been shown to develop atherosclerosis when challenged with hypercholesterolemic diets. In addition, plasma lipid profiles in males, females and ovariectomized guinea pigs, a model for menopause, follow similar patterns to those observed in humans. In this report, drugs aimed at lowering plasma cholesterol and triglycerides in hyperlipidemic individuals are reviewed. Studies analyzing the hypolipidemic effect of HMG-CoA reductase inhibitors, acyl CoA cholesterol acyltransferase inhibitors, fibrates, bile acid resins, apical sodium bile acid transporter inhibitors, and others show that guinea pigs and humans have comparable responses to drug therapy. In addition, results from the limited clinical reports addressing specific effects of drugs on LDL catabolism or VLDL synthesis are in agreement with observations in guinea pigs. From the review of these studies, it is apparent that the guinea pig is a useful animal model to further explore the mechanisms of action of lipid lowering drugs including effects on specific receptors and regulatory enzymes involved in cholesterol metabolism and on early atherosclerosis development.

Notes: The cardiac sodium-calcium exchanger (NCX) plays an important role in calcium homeostasis. It is the primary mechanism for removing calcium ions that enter myocytes through L-type calcium channels on a beat-to-beat basis. Its direction of transport is determined by the membrane potential and the ionic concentrations of Na+ and Ca2+, with the forward (or Ca2+-efflux) mode of transport being the dominant mode under physiological conditions. In contrast, the Ca2+-influx mode (or reverse mode) of NCX becomes important in certain pathophysiological conditions, such as myocardial ischemia and reperfusion. Recent discovery of compounds that inhibit the Ca2+-influx mode (or reverse mode) of NCX has generated intense research interest in the pharmacology of NCX. Among the newer NCX inhibitors described to date, 2-[4-[(2,5-difluorophenyl)methoxy]-phenoxy]-5-ethoxyaniline (SEA0400) appears particularly promising in attenuating cardiac, renal, and cerebral ischemia/reperfusion injuries in various experimental models. Moreover, the mixed results that have emerged from clinical trials evaluating the efficacy and safety of inhibitors of the sodium-hydrogen exchanger (an upstream target in relation to the sodium-calcium exchanger) in myocardial protection stimulated interest in evaluating NCX as an alternative therapeutic target. This article reviews the pharmacological profile of SEA0400, as presented in the published literature, and discusses the therapeutic potential of this compound in attenuating myocardial ischemia/reperfusion injury.

Notes: Nebivolol is a racemic mixture of d- and 1-enantiomers. The drug is characterized by β1-adrenoceptor selectivity and long-acting β1-blockade exerted predominantly by d-enantiomer. Nebivolol is devoid of intrinsic sympathomimetic activity and has no relevant membrane stabilizing action. Antiproliferative properties of nebivolol were demonstrated in endothelial and smooth muscle cell cultures. Infusion of nebivolol causes a vasodilation in all vascular beds by endothelial-dependent mechanism involving stimulation of β3-adrenoceptors as well as by endothelial-independent mechanism. Nebivolol possesses not only direct vasodilator properties but also augments the action of endothelium-dependent vasodilators. The antioxidant property of nebivolol can at least in part explain why treatment with this drug enhances eNOS activity and minimizes the reperfusion-induced myocardial injury. The systemic effects of nebivolol in humans have an unusual hemodynamic profile. In contrast to traditional β-adrenoceptor antagonists, nebivolol reduces preload and afterload due to systemic vasodilation and improves arterial distensibility. At 5 mg daily nebivolol effectively reduces systolic and diastolic blood pressure over a 24-h period. During treatment with nebivolol arterial pressure follows the natural circadian rhythm. Trough-to-peak ratio for nebivolol is 0.9. It has been demonstrated in numerous placebo-controlled studies that exercise tolerance is not reduced during nebivolol therapy. By chronic administration to patients with left ventricular dysfunction nebivolol increases myocardial contractility. Nebivolol produced no significant changes in lipid levels, insulin sensitivity or glucose tolerance. These findings make nebivolol a promising therapeutic tool for the treatment of arterial hypertension and chronic heart failure.

Notes: We show that the presence of sufficiently significant switching costs, which are increasing in the degree of product differentiation, generates an equilibrium configuration with maximal differentiation within the framework of a Hotelling model with linear transportation costs. The equilibrium with maximal differentiation offers a formalization of the idea that competing firms have noncooperative incentives to establish maximal switching cost barriers. The equilibrium incentives for commitments to high switching costs can be explained with poaching profits, which are increasing in the switching costs. Ex ante competition for market shares in period 1 is unable to eliminate these poaching profits.

Notes: We analyze competition between two private television channels that derive their profits from advertising receipts. These profits are shown to be proportional to total population advertising attendance. The channels play a sequential game in which they first select their profiles (program mixes) and then their advertising ratios. We show that these ratios play the same role as prices in usual horizontal differentiation models. We prove that whenever ads' interruptions are costly for viewers the program mixes of the channels never converge but that the niche strategies are less effective and that the channel “profiles” are closer as advertising aversion becomes stronger.

Notes: All-units discounts in retail contracts refer to discounts that lower a retailer's wholesale price on every unit purchased when the retailer's purchases equal or exceed some quantity threshold. These discounts pose a challenge to economic theory because it is difficult to understand why a manufacturer ever would charge less for a larger order if its intentions were benign. In this paper, we show that all-units discounts may profitably arise absent any exclusionary motive. All-units discounts eliminate double marginalization in a complete information setting, and they extract more profit than would a menu of two-part tariffs in the standard incomplete information setting with two types of buyers. All-units discounts may improve or may reduce welfare (relative to menus of two-part tariffs) depending on demand parameters.

Notes: This paper is concerned with communication within a team of players trying to coordinate in response to information dispersed among them. The problem is nontrivial because they cannot communicate all information instantaneously but have to send longer or shorter sequences of messages, using coarse codes. We focus on the design of these codes and show that members may gain compatibility advantages by using identical codes and that this can support the existence of several, more or less efficient, symmetric equilibria. Asymmetric equilibria may exist only if coordination across different sets of members is of sufficiently different importance. The results are consistent with the stylized fact that firms differ even within industries and that coordination between divisions is harder than coordination inside divisions.

Notes: We analyze optimal patent design when innovators can rely on secrecy to protect their innovations. Secrecy has no fixed term but does not preclude accidental disclosure nor independent creation by other inventors. We derive the optimal scope of the rights conferred to such second inventors, showing that if the patent life is set optimally, second inventors should be allowed to patent and to exclude first inventors who have relied on secrecy. We then identify conditions under which it is socially desirable to increase patent life as much as is necessary to induce first inventors to patent. The circumstances in which it is preferable that they rely on secrecy seem rather limited.

Notes: Dental implant screw fracture involves attempting to retrieve the screw fragment or, as an alternative, attempting to salvage the dental implant. Circumstances that do not allow for screw retrieval require a solution in which the internal configuration of the dental implant can provide for a custom direct dowel fabrication. The proposed technique is to retrofit the fabrication of a custom cast dowel-core and provisional use of a direct procedure, which provides accuracy of fit, retention, and ease of production.

Notes: Purpose:The objective of this study was to evaluate the effect of different surface treatments on the microtensile bond strength (μ-tbs) of composite bonded to hot-pressed ceramic. The null hypothesis tested was that neither of the surface treatments (silanization or fluoric acid etching) would produce greater bond strength of composite resin to the ceramic. Materials and Methods:Four 7 × 7 × 5 mm hot-pressed ceramic blocks of IPS Empress 2 were fabricated and polished to 600 grit followed by sandblasting with 50 μm alumina. The ceramic blocks were then divided into four groups and submitted to the following surface treatments: Group 1: 9.5% hydrofluoric (HF) acid for 20 seconds and silane (S) for 3 minutes; Group 2: silane for 3 minutes; Group 3: 9.5% HF acid for 20 seconds; Group 4: no treatment. Scotchbond adhesive was applied to the treated ceramic surfaces and covered with Filtek Z250 composite resin. The composite-ceramic blocks were cut with an Isomet low speed diamond saw machine producing sticks (n = 25), which were loaded to failure under tension in an Instron Universal testing machine. The mean μ-tbs was analyzed with one-way ANOVA and Bonferroni “t” test. Results:All specimens of Group 4 experienced adhesive failure during the cutting of the block and were eliminated. The mean μ-tbs and standard deviations (SD) in megaPascals were: Group 1 = 56.8 (±10.4), Group 2 = 44.8 (±11.6), Group 3 = 35.1 (±7.7). Statistical analysis showed that the bond strength was significantly affected by surface treatment (p 〈 0.0001). Group 1 (HF + S) had the highest μ-tbs, and Group 2 (S) had higher μ-tbs than Group 3 (HF). The mode of fracture of the specimens was examined using scanning electron microscopy (SEM), and all fractures occurred within the adhesion zone. Conclusion:The results show that surface treatment is important for resin adhesion to ceramic and suggest that silane treatment was the main factor responsible for resin bonding to ceramic.

Notes: Purpose: To evaluate the consistency prior to the setting of 5 elastomeric interocclusal recording materials in comparison with a wax and a zinc oxide–eugenol paste. This property is related to the viscosity as well as to the working and setting times of these materials. Materials and Methods: Testing of consistency was performed following a modification of the method described in ADA Specification No. 19, for elastomeric impression materials. Each one of the tested materials was mixed for 20 seconds and was then loaded into a 0.5 mL syringe. The material was syringed onto a 10 × 10 × 0.5 cm glass plate. A second 575 g glass plate was placed on top of the unset interocclusal registration material. A total of 10 samples were tested for each material. The surface area covered by the materials was measured with the help of a scanner and the use of appropriate computer software. Results: One-way ANOVA revealed significant differences among the materials (F = 889.493, p 〈 0.0005). According to Tukey's honest significant difference test, all materials were significantly different (p 〈 0.05) from one another. All polyvinylsiloxanes occupied a smaller area than that of the polyether and of the zinc oxide–eugenol paste. Conclusions: Zinc oxide–eugenol paste was the most fluid of all materials tested. Polyvinylsiloxanes displayed less flow properties than polyether.

Notes: For continuous data, risk is defined here as the proportion of animals with values above a large percentile, e.g., the 99th percentile or below the 1st percentile, for the distribution of values among control animals. It is known that reducing the standard deviation of measurements through improved experimental techniques will result in less stringent (higher) doses for the lower confidence limit on the benchmark dose that is estimated to produce a specified risk of animals with abnormal levels for a biological effect. Thus, a somewhat larger (less stringent) lower confidence limit is obtained that may be used as a point of departure for low-dose risk assessment. It is shown in this article that it is important for the benchmark dose to be based primarily on the standard deviation among animals, sa, apart from the standard deviation of measurement errors, sm, within animals. If the benchmark dose is incorrectly based on the overall standard deviation among average values for animals, which includes measurement error variation, the benchmark dose will be overestimated and the risk will be underestimated. The bias increases as sm increases relative to sa. The bias is relatively small if sm is less than one-third of sa, a condition achieved in most experimental designs.

Notes: For diseases with more than one risk factor, the sum of probabilistic estimates of the number of cases caused by each individual factor may exceed the total number of cases observed, especially when uncertainties about exposure and dose response for some risk factors are high. In this study, we outline a method of bounding the fraction of lung cancer fatalities not due to specific well-studied causes. Such information serves as a “reality check” for estimates of the impacts of the minor risk factors, and, as such, complements the traditional risk analysis. With lung cancer as our example, we allocate portions of the observed lung cancer mortality to known causes (such as smoking, residential radon, and asbestos fibers) and describe the uncertainty surrounding those estimates. The interactions among the risk factors are also quantified, to the extent possible. We then infer an upper bound on the residual mortality due to “other” causes, using a consistency constraint on the total number of deaths, the maximum uncertainty principle, and the mathematics originally developed of imprecise probabilities.

Notes: A strong inverse correlation was observed between the polycyclic aromatic hydrocarbon (PAH) mass fraction desorbed, a surrogate measure of bioavailability, and relative carcinogenicity, as quantified by potency equivalency factors (PEFs), for two study sediments from the New York/New Jersey Harbor estuary. Because compounds with the highest toxicity, such as dibenz(a,h)anthracene and benzo(a)pyrene (BAP), also tended to be the least rapidly and least extensively desorbed, the U.S. Environmental Protection Agency (EPA) default guidance may dramatically overestimate risk from exposure to PAH-contaminated soils or sediments. A “relative risk index” (RRI) was developed to account for the combined effects of compound-specific bioavailability and toxic potency in estimating excess cancer risk. Using this approach, estimated excess cancer risk may be diminished by as much as a factor of 159 times versus default EPA guidance. Also, the hierarchy of estimated risk between study sediments and among treatment fractions of study sediments differed using the two approaches, implying that the default approach may inaccurately determine site clean-up priorities. The percentage contribution of each potentially carcinogenic priority PAH to total excess cancer risk was computed under various scenarios. In each case, the contribution of BAP to total excess cancer risk was remarkably invariable, for example, ranging from 48% to 52% in one sediment, and 44% to 54% in the other, over four different exposure durations. These results suggest that BAP may be an excellent indexing compound for gauging relative exposure risk across sediments. Other important contributors to total excess cancer risk were benz(a)anthracene and dibenz(a,h)anthracene. Together, these three compounds comprised nearly 90% of total excess cancer risk from all PAHs in every scenario. This integrated RRI approach may enable regulators to more accurately gauge relative risks and make more informed sediment management decisions.

Notes: The effectiveness of a probabilistic risk assessment (PRA) depends on the quality and relevance of the output from exposure and risk models, which, in turn, depends on the critical inputs to the assessment. These critical inputs are often in the form of probabilistic exposure factor distributions that are derived for the given risk scenario. Deriving probabilistic distributions for model inputs can be time consuming and subjective. The absence of a standard approach for developing these distributions can result in PRAs that are inconsistent and difficult to review by regulatory agencies. We present an approach that reduces subjectivity in the distribution development process without limiting the flexibility needed to prepare relevant PRAs. The approach requires two steps. First, we analyze data pooled at a population scale to (i) identify the most robust demographic descriptors within the population for a given exposure factor, (ii) partition the data into subsets based on these variables, and (iii) construct archetypal distributions for each subpopulation. Second, we sample from these archetypal distributions according to site- or scenario-specific conditions to simulate exposure factor values and use these values to construct the scenario-specific input distribution. The archetypal distributions developed through Step 1 provide a consistent basis for developing scenario-specific distributions so risk assessors will not have to repeatedly collect and analyze raw data for each new assessment. We demonstrate the approach for two commonly used exposure factors—body weight (BW) and exposure duration (ED)—using data that are representative of the U.S. population. For these factors we provide a first set of subpopulation-based archetypal distributions and demonstrate methods for using these distributions to construct relevant scenario-specific probabilistic exposure factor distributions.