Validation of biplane high‐speed fluoroscopy combined with two different noninvasive tracking methodologies for measuring in vivo distal limb kinematics of the horse          下载免费PDF全文

S. M. Geiger  E. Reich  P. Böttcher  S. Grund  J. Hagen 《Equine veterinary journal》2018,50(2):261-269

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Seedlings of five boreal tree species differ in acclimation of net photosynthesis to elevated CO(2) and temperature   总被引：1，自引：0，他引：1  

Tjoelker MG  Oleksyn J  Reich PB 《Tree physiology》1998,18(11):715-726

Biochemical models of photosynthesis suggest that rising temperatures will increase rates of net carbon dioxide assimilation and enhance plant responses to increasing atmospheric concentrations of CO(2). We tested this hypothesis by evaluating acclimation and ontogenetic drift in net photosynthesis in seedlings of five boreal tree species grown at 370 and 580 &mgr;mol mol(-1) CO(2) in combination with day/night temperatures of 18/12, 21/15, 24/18, 27/21, and 30/24 degrees C. Leaf-area-based rates of net photosynthesis increased between 13 and 36% among species in plants grown and measured in elevated CO(2) compared to ambient CO(2). These CO(2)-induced increases in net photosynthesis were greater for slower-growing Picea mariana (Mill.) B.S.P., Pinus banksiana Lamb., and Larix laricina (Du Roi) K. Koch than for faster-growing Populus tremuloides Michx. and Betula papyrifera Marsh., paralleling longer-term growth differences between CO(2) treatments. Measures at common CO(2) concentrations revealed that net photosynthesis was down-regulated in plants grown at elevated CO(2). In situ leaf gas exchange rates varied minimally across temperature treatments and, contrary to predictions, increasing growth temperatures did not enhance the response of net photosynthesis to elevated CO(2) in four of the five species. Overall, the species exhibited declines in specific leaf area and leaf nitrogen concentration, and increases in total nonstructural carbohydrates in response to CO(2) enrichment. Consequently, the elevated CO(2) treatment enhanced rates of net photosynthesis much more when expressed on a leaf area basis (25%) than when expressed on a leaf mass basis (10%). In all species, rates of leaf net CO(2) exchange exhibited modest declines with increasing plant size through ontogeny. Among the conifers, enhancements of photosynthetic rates in elevated CO(2) were sustained through time across a wide range of plant sizes. In contrast, for Populus tremuloides and B. papyrifera, mass-based photosynthetic rates did not differ between CO(2) treatments. Overall, net photosynthetic rates were highly correlated with relative growth rate as it varied among species and treatment combinations through time. We conclude that interspecific variation may be a more important determinant of photosynthetic response to CO(2) than temperature.  相似文献   

Quantifying plant response to ozone: a unifying theory   总被引：36，自引：0，他引：36  

Reich PB 《Tree physiology》1987,3(1):63-91

Published information about the effects of ozone on plants and ecosystems is synthesized into a conceptual model to explain the response of evergreen conifers, deciduous hardwoods and agricultural crops to ambient levels of ozone pollution. The effects of ozone on carbon balance and growth of individual plants can be quantified on the basis of concentration, external dose (concentration x duration of exposure), or uptake. For an equivalent dose within a single growing season, agricultural crops are the most sensitive to ozone, with hardwoods intermediate and conifers least sensitive. In contrast, all species display a similar decline in photosynthesis and growth in response to equivalent total uptake or uptake per leaf life span, with trees somewhat less sensitive than agricultural crops on a calendar time scale, but slightly more sensitive on a relative (leaf life span) time scale. Among species, differences in ozone uptake and response can be predicted from differences in the inherent leaf diffusive conductance.  相似文献   

Evidence that longer needle retention of spruce and pine populations at high elevations and high latitudes is largely a phenotypic response     

Reich PB  Oleksyn J  Modrzynski J  Tjoelker MG 《Tree physiology》1996,16(7):643-647

There is abundant evidence that evergreen conifers living at high elevations or at high latitudes have longer-lived needles than trees of the same species living elsewhere. This pattern is likely caused by the influence of low temperature in combination with related factors such as a short growing season and low nutrient availability. Because it is not known to what degree such patterns result from phenotypic versus genotypic variation, we evaluated needle longevity for common-garden-grown lowland populations of European Scots pine (Pinus sylvestris L.) of wide latitudinal origin and Norway spruce (Picea abies L.) of wide elevational origin. Nine-year-old trees of 16 Scots pine populations ranging in origin from 47 degrees to 60 degrees N were studied in Kórnik, Poland (52 degrees N) and 18-year-old trees of 18 Norway spruce populations ranging in origin from 670 to 1235 m elevation in southwestern Poland were studied near Morawina, Poland (51 degrees N, 180 m elevation). There was no tendency in either species for populations from northern or high elevation origins to retain needles longer than other populations. All of the Scots pine populations had between 2.5 to 3.0 needle age cohorts and all of the Norway spruce populations had between 6.4 and 7.2 needle age cohorts. Thus, extended needle retention in Scots pine and Norway spruce populations in low-temperature habitats at high elevations and high latitudes appears to be largely an environmentally regulated phenotypic acclimation.  相似文献   

Genetic and environmental control of seasonal carbohydrate dynamics in trees of diverse Pinus sylvestris populations     

Oleksyn J  Zytkowiak R  Karolewski P  Reich PB  Tjoelker MG 《Tree physiology》2000,20(12):837-847

We explored environmental and genetic factors affecting seasonal dynamics of starch and soluble nonstructural carbohydrates in needle and twig cohorts and roots of Scots pine (Pinus sylvestris L.) trees of six populations originating between 49 degrees and 60 degrees N, and grown under common garden conditions in western Poland. Trees of each population were sampled once or twice per month over a 3-year period from age 15 to 17 years. Based on similarity in starch concentration patterns in needles, two distinct groups of populations were identified; one comprised northern populations from Sweden and Russia (59-60 degrees N), and another comprised central European populations from Latvia, Poland, Germany and France (49-56 degrees N). Needle starch concentrations of northern populations started to decline in late spring and reached minimum values earlier than those of central populations. For all populations, starch accumulation in spring started when minimum air temperature permanently exceeded 0 degrees C. Starch accumulation peaked before bud break and was highest in 1-year-old needles, averaging 9-13% of dry mass. Soluble carbohydrate concentrations were lowest in spring and summer and highest in autumn and winter. There were no differences among populations in seasonal pattern of soluble carbohydrate concentrations. Averaged across all populations, needle soluble carbohydrate concentrations increased from about 4% of needle dry mass in developing current-year needles, to about 9% in 1- and 2-year-old needles. Root carbohydrate concentration exhibited a bimodal pattern with peaks in spring and autumn. Northern populations had higher concentrations of fine-root starch in spring and autumn than central populations. Late-summer carbohydrate accumulation in roots started only after depletion of starch in needles and woody shoots. We conclude that Scots pine carbohydrate dynamics depend partially on inherited properties that are probably related to phenology of root and shoot growth.  相似文献   

Evaluation of harmful algal bloom outreach activities          下载免费PDF全文

Fleming LE  Jerez E  Stephan WB  Cassedy A  Bean JA  Reich A  Kirkpatrick B  Backer L  Nierenberg K  Watkins S  Hollenbeck J  Weisman R 《Marine drugs》2007,5(4):208-219

With an apparent increase of harmful algal blooms (HABs) worldwide, healthcare providers, public health personnel and coastal managers are struggling to provide scientifically-based appropriately-targeted HAB outreach and education. Since 1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year free Aquatic Toxins Hotline (1–888–232–8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-related illness among callers are reported to the Florida Health Department. This pilot study evaluated an automated call processing menu system that allows callers to access bilingual HAB information, and to speak directly with a trained Poison Information Specialist. The majority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.  相似文献   

In vitro modulation of reactive oxygen and nitrogen intermediate (ROI/RNI) production in Crassostrea gigas hemocytes     

Christophe Lambert  Philippe Soudant  Marine Jegaden  Maryse Delaporte  Yannick Labreuche  Jeanne Moal  Jean-Franois Samain 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):413-421

Bivalve hemocyte competence has been measured by quantifying functional characteristics, including reactive oxygen intermediate (ROI) production after activation with zymosan or phorbol myristate acetate (PMA). However, untreated oyster hemocytes also produce ROI and RNI (reactive nitrogen intermediates) after bleeding even if not stimulated by zymosan or PMA. Extensive investigation of this parameter by flow cytometry showed that, in vitro, ROI/RNI production by untreated hemocytes maintained in seawater appeared to be independent of both bacterial burden in the serum and non-self particle phagocytosis. ROI/RNI production in granulocytes was higher than in hyalinocytes and could be intensified when activated by zymosan but not by PMA. Both cell types used NADPH-oxidase- and NO-synthase-like pathways to produce these molecules; the NO-synthase pathway seemed relatively more dominant in hyalinocytes and NADPH-oxidase appeared more effective in granulocytes. These results provide new insights for interpreting the modulation of ROI/RNI production by untreated hemocytes shown by other studies, relative to environmental conditions or physiological status of the oysters.  相似文献   

Soluble sugars and carboxylic acids in ripe apricot fruit as parameters for distinguishing different cultivars     

Fabrizio Gurrieri  Jean-Marc Audergon  Guy Albagnac  Maryse Reich 《Euphytica》2001,117(3):183-189

Major sugar and carboxylic acid components in apricot flesh fruits were detected and quantified. Fifty-one genotypes including clones growing in France, Spain, Italy, Greece and USA, belonging to the INRA germ plasm collection has been evaluated. Principal component analysis (PCA) has been performed to study correlation among fruit quality measurements and to interpret relationships between genotypes as a tool for germ plasm characterization. A marked variation in malic and citric acid content has been observed and PCA revealed clusters of apricot genotypes for the malic/citric ratio content. A good correlation between sugar component and refractometer index (r = 0.83) has been detected. The wide range of diversity in malic and citric acid content in apricot germ plasm makes it possible to breed and select genotypes with improved flavour on the basis of superior phenotypes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Inheritance of groat protein percentage in Avena sativa L. × A. Fatua L. Crosses     

J. M. Reich  M. A. Brinkman 《Euphytica》1984,33(3):907-913

Summary Gene action and heritability of groat protein percentage were determined in F₁, F₂, and F₃ generations of nine crosses between three Avena sativa L. cultivars and three A. fatua L. selections. Relationships among groat protein percentage, grain yield, and 100-seed weight also were evaluated. The three A. sativa parents were Dal (high grain yield and intermediate groat protein percentage), Goodland (low grain yield and high groat protein percentage), and Stout (high grain yield and low groat protein percentage). The three A. fatua parents were chosen for the study on the basis of vigorous plant growth and high groat protein percentage. The study was conducted at Madison, Wisconsin in 1979 and 1980.There was partial dominance towards low groat protein percentage. Narrow sense heritability estimates for groat protein percentage were low in Dal and Goodland crosses and intermediate in Stout crosses. In the F₂ generation, groat protein percentage was significantly higher in shattering than in nonshattering plants in 1979, but not in 1980. There were significant, positive correlations between groat protein percentage, 100-seed weight, and grain yield in F₁ and F₂ generations, but they were not large numerically. Relationships among these traits were either negative or nonsignificant in the F₃ generation. Although our results indicated that selection for higher groat protein percentage is possible when a low protein A. sativa cultivar is used, most of our simple cross progenies from A. sativa x A. fatua crosses had weak straw and were susceptible to crown rust (Puccinia coronata Cda. var. avenae Fraser and Led.).  相似文献   

Group B erythrocytes enzymatically converted to group O survive normally in A, B, and O individuals   总被引：9，自引：0，他引：9  

J Goldstein  G Siviglia  R Hurst  L Lenny  L Reich 《Science (New York, N.Y.)》1982,215(4529):168-170

With an alpha-galactosidase, B erythrocytes can be converted to blood group O under conditions that neither impair their viability in vitro nor affect their ability to survive normally after transfusion to individuals of groups O, A, and B. Such an approach has the potential for producing enzymatically converted group O cells for use in transfusion therapy. It should also be possible to convert A cells to group O by using the appropriate alpha-N-acetylgalactosaminidase.  相似文献