Development of <Emphasis Type="Italic">Peronospora parasitica</Emphasis> epidemics on radish as modelled by the effects of water vapour saturation deficit and temperature     

Andreas Kofoet  Mathias Fink 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):369-381

Epidemics of Peronospora parasitica are strongly affected by temperature and air moisture, and the interaction of these factors. Because a significant percentage of radish plants are grown in greenhouses, it may be possible to influence epidemics by altering the greenhouse climate. The objective of this study was to test the hypothesis that epidemics of P. parasitica can be modelled by the effects of air temperature and moisture in the greenhouse. Such a model could then be used to analyse greenhouse climate control strategies with regard to managing downy mildew. Five radish crops were grown under greenhouse conditions with set-points for heating and ventilation intended to obtain favourable conditions for disease development during the first part of the growing cycle. Subsequent to this first phase, unfavourable conditions were set until harvest. Disease incidence was measured once a week until the radishes reached marketable size. In addition, experiments were carried out in growth chambers in which inoculated plants were subjected to air temperatures between 8 and 27°C, and disease incidence and sporulation intensity were measured. Data from these two experiments were then used to estimate model parameters. In this model, the interactions of air temperature (T) and water vapour saturation deficit (SD) were adequately described by a multiplicative relationship. The simulated epidemics by the fitted model were highly correlated with the observed epidemics (r = 0.91, R ² = 0.83, n = 29). Parameter estimates indicated that T of ca. 20°C and SD < 0.03 hPa resulted in the highest rates of disease development and that the rate was zero when SD > 2.0 hPa. Both experimental data and simulations showed that epidemics of P. parasitica can be effectively controlled by managing the greenhouse climate.  相似文献   

CONCERNING BOTANICAL INVESTIGATION IN COLLEGES     

Fink B 《Science (New York, N.Y.)》1911,34(879):593-595

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Forest decline, nutrient supply and diagnostic fertilization in southwestern Germany and in southern California     

R.F. Huettl  S. Fink  H.-J. Lutz  M. Poth  J. Wisniewski 《Forest Ecology and Management》1990,30(1-4):341-350

Since the mid-1970's new types of forest damage (of unknown origin) were observed in West Germany. Nonspecific foliage losses and foliar discolorations are the most common symptoms. This resulted in a comprehensive research program being initiated in the fall of 1983 to investigate the nutritional status of Norway spruce (Picea abies (L.) Karst.) stands in southwest Germany, growing on a variety of sites. Forests at these sites revealed light to moderate damage or acute site-and species-specific nutritional disturbances involving Mg, K, Ca, Mn, and Zn. Historical comparisons of needle-analysis data showed a dramatic change of the nutrient supply at many sites over the last one or two decades.

As a working hypothesis, the adverse impacts of air pollutants (e.g. photo-oxidants) and/or acidic atmospheric precipitation are seen as inciting factors causing increased leaching of nutrient elements. The tree's potential to compensate for the nutrient losses by increased uptake are limited by the often poor nutrient supply for forest soils. Accelerated soil acidification increase nutrient leaching from the soil, probably enhancing decline. Over a short period, fertilization led to a decrease or to the disappearance of the symptoms, and to the improvement in the nutrient composition of the foliage.

Microscopy investigation of Norway-spruce needles indicated the regeneration potential on a histological level for moderate yellowed needles after fertilization. Furthermore, needles of nutrient-deficient-trees reveal typical tissue damages different to those caused by SO₂ or O₃.

Acid mist increased the leaching of K, Ca, Mg, Mn, and Zn from the foliage. Even when nutrients are being leached from the foliage, nutrient uptake canbe increased by improving the nutrient supply in the soil.

Preliminary studies on the effects of damages caused by ozone (O₃) on ponderosa pine suggest imbalance in micronutrient concentrations of foliage.  相似文献   

Buchbesprechungen     

F. Binder  S. Fink 《European Journal of Forest Research》1992,111(1):137-140

Ohne Zusammenfassung  相似文献   

Aufnahme,Transport und Verbleib von Calcium und Magnesium in Fichten (Picea abies [L.] Karst.) und Kiefern (Pinus silvestris L.) bei unterschiedlicher Ernährung und Schadstoffbelastung     

S. Türk  M. Gülpen  S. Fink 《European Journal of Forest Research》1993,112(1):191-208

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Workshop report: The 2012 Antimicrobial Agents in Veterinary Medicine: exploring the consequences of antimicrobial drug use: a 3‐D approach     

M. Martinez  J. Blondeau  C. E. Cerniglia  J. Fink‐Gremmels  S. Guenther  R. P. Hunter  X.‐Z. Li  M. Papich  P. Silley  S. Soback  P.‐L. Toutain  Q. Zhang 《Journal of veterinary pharmacology and therapeutics》2014,37(1):e1-e16

Antimicrobial resistance is a global challenge that impacts both human and veterinary health care. The resilience of microbes is reflected in their ability to adapt and survive in spite of our best efforts to constrain their infectious capabilities. As science advances, many of the mechanisms for microbial survival and resistance element transfer have been identified. During the 2012 meeting of Antimicrobial Agents in Veterinary Medicine (AAVM), experts provided insights on such issues as use vs. resistance, the available tools for supporting appropriate drug use, the importance of meeting the therapeutic needs within the domestic animal health care, and the requirements associated with food safety and food security. This report aims to provide a summary of the presentations and discussions occurring during the 2012 AAVM with the goal of stimulating future discussions and enhancing the opportunity to establish creative and sustainable solutions that will guarantee the availability of an effective therapeutic arsenal for veterinary species.  相似文献   

Model experiments with rats fed peloid and peloid extracts     

J Fink 《DTW. Deutsche tier?rztliche Wochenschrift》1985,92(4):145-147

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Pharmacokinetic studies of ivermectin: effects of formulation     

P K Lo  D W Fink  J B Williams  J Blodinger 《Veterinary research communications》1985,9(4):251-268

Studies are reported which describe the effects of formulation, animal species, and route of administration on the pharmacokinetics of ivermectin. Biological half-life t1/2 increases in the order: swine (0.5 day) less than dogs (1.8 day) less than cattle approximately equal to sheep (2.8 day). Formulation modifications, based upon the solubility properties of the drug, have been directed towards the development of a nonaqueous injectable formulation for cattle and an aqueous vehicle for horses. Bioavailability following subcutaneous injection in cattle can be regulated by control of injection solvent composition: a vehicle composed of a mixed aqueous-organic solvent exhibits pharmacokinetic properties (i.e., Cp, t1/2, AUC, and F) intermediate between those furnished by an aqueous formulation and via a purely nonaqueous solvent. The longer apparent biological half-life from this latter vehicle (t1/2 = 8.3 days) confirms that a slow absorption process dominates the pharmacokinetics in the nonaqueous injectable product to produce an effective controlled-release formulation. These bioavailability results illustrate the increase in the concentration of an organic solvent and a concomitant decrease in surfactant concentration in a micellar aqueous system for prolonged drug delivery via injection.  相似文献   

Use of a population model to assess the impact of longline fishing on wandering albatross Diomedea exulans populations     

Coleen L. Moloney  John Cooper  Peter G. Ryan  W. Roy Siegfried 《Biological conservation》1994,70(3):195-203

An age-structured model of a wandering albatross Diomedea exulans population is developed to stimulate population trends over time, using demographic parameters from the population at Possession Island, Crozets, during 1968–1986. The simulation results portray a population decreasing at a rate of 2·29% per year, which concurs with global population trends. Sensitivity analyses of model parameters indicate that both adult and juvenile mortality are contributing to the decrease. Wandering albatross mortality is presumed to have increased as a result of deaths caused by longline fishing vessels; such deaths are likely to be relatively more frequent among young, naive birds. The model is used to investigate the potential impacts of new longline fisheries such as that for Patagonian toothfish Dissostichus eleginoides in Antarctica. Assuming longline fishing operations affect juveniles more than adults, there is a time lag of 5–10 years before further decreases in population numbers are reflected in the breeding population. Also, because wandering albatrosses are long-lived, population growth rates take approximately 30–50 years to stabilize after a perturbation. Consequently, caution must be exercised when interpreting population trends; short-term (<20 year) estimates may not provide good indications of long-term trends.  相似文献   

Zur Systematik vonAvena sativa L. und zur Beurteilung vonAvena nuda Höj     

Siegfried Danert 《Genetic Resources and Crop Evolution》1972,19(1):45-51

Zusammenfassung Der NameAvena nuda Höjer ist sowohl zur Kennzeichnung der diploiden als auch der hexaploiden Nackthafer verwendet worden. Der nomenklatorische Typus vonA. sativa L. wird diskutiert. Auf der Grundlage der Gliederungsübersichten von Alefeld, Körnicke, Ascherson und Graebner, Malzev, Mordvinkina und Stanton wird ein System vorgeschlagen, in dem zwei Convarietäten und 19 Varietäten unterschieden werden.

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Taxonomy ofAvena sativa L. and interpretation ofAvena nuda Höjer

Summary The nameAvena nuda Höjer was used for characterizing as the diploid as the hexaploid nacked oats. The nomenclatorical type ofA. sativa L. is discussed. On the basis of the divisions given by Alefeld, Körnicke, Ascherson and Graebner, Malzev, Mordvinkina and Stanton a system is proposed differentiating two convarieties and 19 varieties.

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Avena sativa L. Avena nuda Höj

Avena nuda Höjer , , . A. sativa L. Ha , , , , , , 2 19 .

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