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Notes: The new Schwerionen-Synchrotron (SIS)/Experimenteller Speicher-Ring (ESR) heavy ion accelerator facility [Nucl. Instrum. Methods A 278, 7, 19 (1989)], built for basic atomic and nuclear physics at Darmstadt (Federal Republic of Germany), also provides unique possibilities to study rf accelerator and beam/target interaction physics for inertial confinement fusion driven with heavy ion beams. It is the first machine that offers this opportunity. Beam parameters and experiments planned over the next five years are discussed.

Notes: This paper presents numerical simulations of compression, ignition, and burn of a radiation-driven inertial fusion capsule suitable for use in a heavy-ion-beam-driven laboratory microfusion facility to achieve breakeven (thermonuclear energy output=input radiation energy). These simulations have been carried out using a one-dimensional, three-temperature, Lagrangian computer code medusa-kat [J. Appl. Phys. 60, 898 (1986)]. The basic capsule design is simple and consists of a thin gold microballoon coated with a beryllium ablator. A high-pressure gaseous deuterium–tritium (DT) fuel is filled in the capsule. The capsule is driven by a shaped radiation pulse having a prepulse corresponding to a radiation temperature of 100 eV and a main pulse with a temperature of 300 eV. A parameter study of the capsule gain, G versus input radiation energy over a range 52–76 kJ, has been carried out. The fuel mass has also been varied over a range 0.3–0.8 μg. It has been found that G∼1 can be achieved with an absorbed radiation energy of 70 kJ provided that the fuel mass lies between 0.5 and 0.7 μg. These simulations have also been repeated over the same parameter range but using an unshaped pulse with a constant radiation temperature of 300 eV. An overall reduction of 10%–30% has been observed in the gain curves in this case.

Notes: A mathematical model to predict Sorghum hale-pense seedling recruitment dynamics in relation to soil temperature was derived from the experimen-tal results obtained in a previous investigation. The model is based on the assumption that soil temperature controls seedling recruitment of S. halepense by controlling release from dormancy and germination rate once dormancy breakage has been produced. The previous analysis sup-plied mathematical functions to describe both the release from dormancy as controlled by tempera-ture fluctuations, and the response to ‘thermal time’ after dormancy breakage. These relation-ships were used in the construction of the model. This was tested against experimental field data with two differently aged seedbanks, in two seasons: spring and autumn. In each case in situ germination was monitored in plots with bare soil or soil surface shaded to simulate cover by a canopy. Soil temperature was recorded hourly and was used as an input of the model.A good description of seedling emergence dynamics in the field was obtained with the model, showing that seedling recruitment can be predicted using soil temperature data. The practi-cal value of the developed model is discussed.

Notes: Seed dormancy in Sorghum halepense is overcome by exposure to fluctuating temperatures and the effect is determined both by the diurnal amplitude and the maximum temperature. It was found that repeated cycles of particular regimes were additive, each cycle resulting in release from dormancy of a further proportion of the population. The range of regimes having this additive effect was wider in seeds which had after-ripened in the soil during winter than in those which were freshly dispersed. The temperature-dependent germination rate of seeds whose dormancy had been removed by the effect of fluctuating temperatures was analysed using a ‘thermal time’ approach, and estimates obtained of base and optimum temperatures and the required ‘thermal time’ for the germination of different fractions of the population. The results provide a basis for developing a model to predict seedling recruitment in the field using soil temperature data.

Notes: The Macaca mulatta species of rhesus monkey is one of several non-human primate (nhp) models for periodontal disease. This report presents the bacteriology of the gingival sulci in M. mulatta monkeys. Three sub-gingival sites (maxillary right central incisor, the disto-buccal of the mandibular left second molar and mesio-buccal of the mandibular right second molar) of 9 monkeys were evaluated clinically before scaling and 7 days after scaling. Plaque samples were obtained from sub-gingival sites before clinical examination and studied bacteriologically by dark field microscopy, selective and non-selective culture, and by primary phenotypic characterizations of culture isolates. Several gingival sites presented with mild gingival inflammation. Anaerobic and facultatively anaerobic bacteria were the predominant flora colonizing the gingival sulci. The major microbial groups were Haemophilus species (100% of sites; percentage of total anaerobic count (TAC); 21-51), Peptostreptococcus micros (89%, 7.5–29.5), Actinomyces sp. (85%, 7–27), Fusobacterium nucleatum (90%, 5–8), Actinobacillus actinomycetemcomitans (73%, 1.3–12), black-pigmented anaerobic rods (BPAR) (80%, 0.6–6.5) and oral streptococci (80%, 0.2–1.0). Microbial groups detected less often were Wolinella sp. (66%, 0–2.6), Capnocytophaga sp. (30%), Eikenella corrodens (4.7%, 0), Campylobacter sp. (28%, 0–0.1) and spirochetes (4.7%, 0–0.07). Seven days after gingival sites were scaled, the plaque score and indices for gingival inflammation declined significantly. The gingival flora after scaling were characterized by lower proportions of the Actinomyees sp., P. micros and BPAR; and increased proportions of the oral streptococci, relative to pre-scaling levels. The major microbial groups at scaled gingival sites were the Haemophilus sp., oral streptococci, F. nucleatum and A. actinomycetemcomitans. The mutual proportions of microbial groups varied non-significantly within gingival sites and between monkeys. In conclusion, the M. mulatta gingival sulci are colonized by microbial species that resemble putative pathogens of periodontal disease, and the composition and character of the gingival flora are similar to the gingival flora of other Old World monkey models.

Notes: The pathogenesis of periodontal tissue destruction involves the orchestrated sequential activation of several components of the host response, each of which have the potential for providing diagnostic information regarding the health or disease status of the periodontium. These events include the bacterial triggering of serum components, the release of vasoactive compounds, the recruitment of inflammatory cells, the activation of phagocytes, the local secretion of immunoglobulins and inflammatory mediators, as well as connective tissue remodeling. For purposes of diagnosis, much attention has been directed toward the measurement of local levels of specific byproducts pathogenic process either within the tissues or in the adjacent crevicular fluid. These are site-directed assessments of the local concentration of these byproducts, and with the important exception of antibody levels, very few byproducts of the periodontal pathogenic process have been studied on a systemic level. However, since the risk associated with periodontal disease progression is primarily patient-based and secondarily site-based, there is an increasing need to identify patients at risk for intervention strategies. Furthermore, there are substantial data that periodontal diseases are specific infections that occur in an appropriately susceptible host. The expression of periodontal disease has a strong genetic component, which presumably defines the host's response thereby affecting susceptibility. For this reason, there is increased interest in defining those elements of the host response which result in susceptibility to disease. The ultimate objective of a diagnostic strategy is to identify patients who are potentially at risk for acquiring disease to enable preventive measures.

Notes: Review Essays