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  • 1
    Electronic Resource
    Electronic Resource
    Does elevated atmospheric CO2 concentration inhibit mitochondrial respiration in green plants? (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 22 (1999), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 
ATP, adenosine triphosphate
Km, Michaelis-Menton coefficient
Ca, concentration of CO2 in the air (μmol mol–1)
NAD, oxidized nicotin adenine dinucleotide
NADH, reduced nicotin adenine dinucleotide
NADP, oxidized nicotin adenine phosphate dinucleotide
NADPH, reduced nicotine adenine phosphate dinucleotide
R, rate of respiration per unit DW [μmol g 
DW–1], Rubisco, ribulose-1,5-bisphosphate carboxylase/oxygenase
Vc,max, maximum in vivo rate of carboxylation at Rubisco (μmol m–2 s–1)

There is abundant evidence that a reduction in mitochondrial respiration of plants occurs when atmospheric CO2 (Ca) is increased. Recent reviews suggest that doubling the present Ca will reduce the respiration rate [per unit dry weight (DW)] by 15 to 18%. The effect has two components: an immediate, reversible effect observed in leaves, stems, and roots of plants as well as soil microbes, and an irreversible effect which occurs as a consequence of growth in elevated Ca and appears to be specific to C3 species. The direct effect has been correlated with inhibition of certain respiratory enzymes, namely cytochrome-c-oxidase and succinate dehydrogenase, and the indirect or acclimation effect may be related to changes in tissue composition. Although no satisfactory mechanisms to explain these effects have been demonstrated, plausible mechanisms have been proposed and await experimental testing. These are carbamylation of proteins and direct inhibition of enzymes of respiration. A reduction of foliar respiration of 15% by doubling present ambient Ca would represent 3 Gt of carbon per annum in the global carbon budget.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.1999.00438.x
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  • 2
    Electronic Resource
    Electronic Resource
    Stomatal acclimation to increased CO2 concentration in a Florida scrub oak species Quercus myrtifolia Willd (2001)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 24 (2001), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Native scrub-oak communities in Florida were exposed for three seasons in open top chambers to present atmospheric [CO2] (approx. 350 μmol mol−1) and to high [CO2] (increased by 350 μmol mol−1). Stomatal and photosynthetic acclimation to high [CO2] of the dominant species Quercus myrtifolia was examined by leaf gas exchange of excised shoots. Stomatal conductance (gs) was approximately 40% lower in the high- compared to low-[CO2]-grown plants when measured at their respective growth concentrations. Reciprocal measurements of gs in both high- and low-[CO2]-grown plants showed that there was negative acclimation in the high-[CO2]-grown plants (9–16% reduction in gs when measured at 700 μmol mol−1), but these were small compared to those for net CO2 assimilation rate (A, 21–36%). Stomatal acclimation was more clearly evident in the curve of stomatal response to intercellular [CO2] (ci) which showed a reduction in stomatal sensitivity at low ci in the high-[CO2]-grown plants. Stomatal density showed no change in response to growth in high growth [CO2]. Long-term stomatal and photosynthetic acclimation to growth in high [CO2] did not markedly change the 2·5- to 3-fold increase in gas-exchange-derived water use efficiency caused by high [CO2].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.2001.00659.x
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  • 3
    Electronic Resource
    Electronic Resource
    Will rising CO2 protect plants from the midday sun? A study of photoinhibition of Quercus myrtifolia in a scrub-oak community in two seasons (2001)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 24 (2001), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Over a large part of the photoperiod, light energy absorbed by upper canopy leaves saturates photosynthesis and exceeds the energetic requirements for light-saturated linear electron flow through photosystem II (JPSII), so that photoinhibition results. From a theoretical consideration of the response of light-saturated photosynthesis to elevated atmospheric CO2 partial pressure (pCO2) it may be predicted that, where light-saturated photosynthesis is Rubisco-limited, an increase in pCO2 will stimulate JPSII. Therefore, the proportion of absorbed quanta dissipated photochemically will increase and the potential for photoinhibition of photosynthesis will decrease. This was tested by measuring modulated chlorophyll a fluorescence from Quercus myrtifolia Willd. growing in the field in open-top chambers, at either current ambient or elevated (ambient + 35 Pa) pCO2 on Merritt Island, Florida, USA. During spring and summer, light-saturated photosynthesis at current ambient pCO2 was Rubisco-limited. Consistent with theoretical prediction, JPSII was increased and photoinhibition decreased by elevated pCO2 in spring. In the summer, when growth had largely ceased, an acclimatory decrease in the maximum Ribulose 1,5 bisphosphate saturated carboxylation capacity (Vc max) removed the stimulation of JPSII seen in the spring, and photoinhibition was increased in elevated pCO2. It is concluded that, for Q. myrtifolia growing in the field, the effects of elevated pCO2 on JPSII and photoinhibition will reflect seasonal differences in photosynthetic acclimation to elevated pCO2 in a predictable manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.2001.00792.x
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  • 4
    Electronic Resource
    Electronic Resource
    The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 20 (1997), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO2. These species comprised wild and agricultural herbaceous plants as well as tree seedlings. Both average responses across species and the range in response were considered. Expressed on a total dry weight basis, the main change in chemical composition due to CO2 was the accumulation of total non-structural carbohydrates (TNC). To a lesser extent, decreases were found for organic N compounds and minerals. Hardly any change was observed for total structural carbohydrates (cellulose plus hemicellulose), lignin and lipids. When expressed on a TNC-free basis, decreases in organic N compounds and minerals were still present. On this basis, there was also an increase in the concentration of soluble phenolics.In terms of glucose required for biosynthesis, the increase in costs for one chemical compound – TNC – was balanced by a decrease in the costs for organic N compounds. Therefore, the construction costs, the total amount of glucose required to produce 1 g of leaf, were rather similar for the two CO2 treatments; on average a small decrease of 3% was found. This decrease was attributable to a decrease of up to 30% in the growth respiration coefficient, the total CO2 respired [mainly for N AD(P)H and ATP] in the process of constructing 1 g of biomass. The main reasons for this reduction were the decrease in organic N compounds and the increase in TNC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.1997.d01-84.x
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  • 5
    Electronic Resource
    Electronic Resource
    Evapotranspiration and soil water content in a scrub-oak woodland under carbon dioxide enrichment (2002)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 8 (2002), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Leaf conductance often decreases in response to elevated atmospheric CO2 concentration (Ca) potentially leading to changes in hydrology. We describe the hydrological responses of Florida scrub oak to elevated Ca during an eight-month period two years after Ca manipulation began. Whole-chamber gas exchange measurements revealed a consistent reduction in evapotranspiration in response to elevated Ca, despite an increase in leaf area index (LAI). Elevated Ca also increased surface soil water content, but xylem water deuterium measurements show that the dominant oaks in this system take up most of their water from the water table (which occurs at a depth of 1.5–3 m), suggesting that the water savings in elevated Ca in this system are primarily manifested as reduced water uptake at depth. Extrapolating these results to larger areas requires considering a number of processes that operate on scales beyond these accessible in this field experiment. Nevertheless, these results demonstrate the potential for reduced evapotranspiration and associated changes in hydrology in ecosystems dominated by woody vegetation in response to elevated Ca.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.2002.00468.x
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  • 6
    Electronic Resource
    Electronic Resource
    Carbon balance and water use efficiency of frequently cut Lolium perenne L. swards at elevated carbon dioxide (1997)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 3 (1997), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: The impact of doubled atmospheric [CO2] on the carbon balance of regularly cut Lolium perenne L. swards was studied for two years under semi-field conditions in the Wageningen Rhizolab. CO2 and H2O vapour exchange rates of the swards were measured continuously for two years in transparent enclosures. The light utilization efficiencies of the swards ranged between 1.5 g CO2 MJ–1 global radiation (high light, ambient [CO2]) and 2.8 g CO2 MJ–1 (low light, doubled [CO2]). The above-ground net primary productivity (NPP) in the enclosures was greater by 29% in 1994 and 43% in 1995 in the doubled [CO2] treatments, but only 20% and 25% more carbon was recovered in the periodical cuts. Thus, NPP increased significantly more than did the harvested above-ground biomass. The positive [CO2] effect on net carbon assimilation is therefore associated with a preferential allocation of extra carbon to the roots and soil.In addition to higher canopy photosynthesis and leaf elongation rates, a small part of the positive [CO2] effects on NPP could be attributed to a decrease of the specific respiration of the shoots. On a canopy basis however, respiration was equal or slightly higher at doubled [CO2] due to the higher amount of standing biomass.Comparison of NPP and carbon recovered in different harvests showed that allocation to roots and soil was highest in spring, it was low in early summer and increased again in late summer and autumn.The total gross amount of carbon partitioned to the roots and soil during the two year period was 57% more at doubled [CO2]. The total amount of carbon that was sequestered in the soil after subtraction of the respiratory losses was 458 g m–2 and 779 g m–2 in the ambient and doubled [CO2] treatments, respectively.The average water use efficiency (WUE) of the swards was increased by a factor 1.5 at doubled [CO2]. Both WUE and its positive interaction with [CO2] varied between years and were positively correlated with global irradiance. At doubled [CO2], the higher WUE was fully compensated for by a higher leaf area index. Therefore, total transpiration on a canopy basis was equal for the ambient and the doubled [CO2] concentrations in both years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.1997.00099.x
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  • 7
    Electronic Resource
    Electronic Resource
    Leaf senescence of Quercus myrtifolia as affected by long-term CO2 enrichment in its native environment (2000)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 6 (2000), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: The long-term effects of elevated (ambient plus 350 μmol mol−1) atmospheric CO2 concentration (Ca) on the leaf senescence of Quercus myrtifolia Willd was studied in a scrub-oak community during the transition from autumn (December 1997) to spring (April 1998). Plants were grown in large open-top chambers at the Smithsonian CO2 Research Site, Merritt Island Wildlife Refuge, Cape Canaveral, Florida. Chlorophyll (a + b) concentration, Rubisco activity and N concentration decreased by 75%, 82%, and 52%, respectively, from December (1997) to April (1998) in the leaves grown at ambient Ca. In contrast, the leaves of plants grown at elevated Ca showed no significant decrease in chlorophyll (a + b) concentration or Rubisco activity, and only a 25% reduction in nitrogen. These results indicate that leaf senescence was delayed during this period at elevated Ca. Delayed leaf senescence in elevated Ca had important consequences for leaf photosynthesis. In elevated Ca the net photosynthetic rate of leaves that flushed in Spring 1997 (last year's leaves) and were 13 months old was not different from fully-expanded leaves that flushed in 1998, and were approximately 1 month old (current year's leaves). In ambient Ca the net photosynthetic rate of last year's leaves was 54% lower than for current year's leaves. When leaves were fully senesced, nitrogen concentration decreased to about 40% of the concentration in non-senesced leaves, in both CO2 treatments. In April, net photosynthesis was 97% greater in leaves grown in elevated Ca than in those grown at ambient. During the period when elevated Ca delayed leaf senescence, more leaves operating at higher photosynthetic rate would allow the ecosystem dominated by Q. myrtifolia to gain more carbon at elevated Ca than at ambient Ca.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.2000.00347.x
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  • 8
    Electronic Resource
    Electronic Resource
    Therapeutic outcome assessment in permanent temporomandibular joint disc displacement (1999)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 26 (1999), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In permanent temporomandibular disc displacement (TMJ-DD) outcome studies many authors claim positive effects of arthroscopic surgery, arthrocentesis and physical therapy. This literature review was undertaken to analyse whether the claimed effects are based on acceptable methodology. The recorded papers were analysed by two independent observers according to (1) method of investigation, (2) therapeutic intervention studied, (3) therapeutic outcome variables used, and (4) claimed effectiveness of the intervention. Agreement between observers was calculated. Twenty-four papers were found in which therapeutic outcome of interventions on temporomandibular disorders were studied. Six studies applied a true experimental design. Each of these six studies compared a different set of interventions. Twenty-two papers used maximal mouth opening (MMO) as an outcome variable, nine studied pain intensity on a visual analogue scale, one paper assessed the mandibular function impairment questionnaire. Kappa for overall agreement concerning the reviewing criteria was 0·82 (P≦0·001). No distinguishing effects on MMO, pain or function impairment were reported between arthroscopic surgery, arthrocentesis and physical therapy. Results of methodological sound outcome studies evaluating the effects of arthroscopic surgery, arthrocentesis and physical therapy are needed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.1999.00417.x
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  • 9
    Electronic Resource
    Electronic Resource
    Influence of mandibular length on mouth opening (1999)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 26 (1999), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Theoretically, mouth opening not only reflects the mobility of the temporomandibular joints (TMJs) but also the mandibular length. Clinically, the exact relationship between mouth opening, mandibular length, and mobility of TMJs is unclear. To study this relationship 91 healthy subjects, 59 women and 32 men (mean age 27·2 years, s.d. 7·5 years, range 13–56 years) were recruited from the patients of the Department of Oral and Maxillofacial Surgery of University Hospital, Groningen. Mouth opening, mobility of TMJs and mandibular length were measured. The mobility of TMJs was measured as the angular displacement of the mandible relative to the cranium, the angle of mouth opening (AMO). Mouth opening (MO) correlated significantly with mandibular length (ML) (r=0·36) and AMO (r=0·66). The regression equation MO=C1×ML×AMO+C2, in which C1=0·53 and C2=25·2 mm, correlated well (r=0·79) with mouth opening. It is concluded that mouth opening reflects both mobility of the TMJs and mandibular length.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.1999.00358.x
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  • 10
    Electronic Resource
    Electronic Resource
    Complexation of water by a 4-phenylpyridohemispherand (1991)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 47 (1991), S. 225-227 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270190006904
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