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91.
Andrey A. Aver��yanov Vera P. Lapikova Tatiana D. Pasechnik Tatiana S. Zakharenkova Con Jacyn Baker 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(4):541-550
Cladosporium cucumerinum spore germination in vitro depended on spore suspension density. Different fungal isolates displayed germination maxima at different spore concentrations. For one isolate, the maximum was observed at the same spore density at both 18 and 25°C, although germination percentage increased slightly at the higher temperature. Diffusates originating in other spore suspensions of the same isolate reduced germination percentage of spores taken at optimal concentration. The least effect occurred in diffusate taken from spores kept at their optimal concentration. Self-suppression of spore germination at unfavourable concentrations was diminished more or less by antioxidants (superoxide dismutase, catalase, mannitol or formate). The same compounds, added to spore diffusates, reduced their fungitoxicities. All diffusates generated superoxide radical (assayed by adrenalin oxidation sensitive to superoxide dismutase). This activity correlated positively with diffusate toxicity. Leaf inoculation of the susceptible cucumber cultivar at 18°C with spore suspensions at extreme densities, at which they germinated poorly in vitro, led to less disease severity then that at optimal density. In contrast, no disease symptoms appeared at 25°C. It is suggested that spores germinating at their extreme concentrations produced reactive oxygen species, suppressing the pathogen; this effect could reduce disease development at low temperatures. At high temperatures, however, this mechanism seems not to work, suggesting that plant infection may be reduced by other disease inhibiting factors. 相似文献
92.
Ey��p Selim K?ksal Bilal Cemek Cengiz Art?k Kadir Ersin Temizel Mehmet Ta?an 《Irrigation Science》2011,29(5):369-377
The neutron moisture meter (NMM) is a widely used device for sensing soil water content (SWC). Calibration accuracy and precision
of the NMM are critical to obtain reliable results, and linear regression analysis of SWC against NMM count data is the most
common method of calibration. In this study, artificial neural network (ANN) calibration models were developed and compared
with linear regression. For this purposes, training and validation data were obtained from 2 calibration and 16 testing plots,
respectively. Calibration plots consist of wet and dry soil water conditions separately. Data measured in dry beans and red
pepper plots that have four different water levels were used to determine validity of regression and ANN-based calibration
models. Volumetric SWC and NMM count ratio measurements were taken for depth intervals of 30 cm throughout a 120-cm-deep soil
profile. Several neural network architectures were explored in order to determine the optimal network architecture. Data analyses
were conducted for each soil layer and for the whole profile, separately, based on both linear regression and ANN. Linear
regression calibration equation coefficients of determination (r
2) for the 0–30, 30–60, 60–90 and 90–120 cm depth ranges calculated by regression models were 0.85, 0.84, 0.72 and 0.82, respectively,
and r
2 values were 0.94, 0.95, 0.87 and 0.88 based on ANN models, respectively. Using the data set from the entire 120-cm soil profile
for calibration by ANN, the r
2 value was raised to 0.97. 相似文献
93.
Leslie A. Thomas DVM Tatiana Bizikova MSc Anne C. Minihan DVM Diplomate ACVS 《Veterinary surgery : VS》2011,40(6):774-780
Objective: To characterize the in vitro elution and bioactivity of 2 formulations of antibiotics in a novel, dissolvable, cross‐linked dextran polymer matrix: Formulation 1—amikacin and clindamycin (AC); Formulation 2—amikacin, clindamycin, and vancomycin (ACV). Study Design: Prospective, in vitro, experimental study. Methods: Aliquots of the antibiotic impregnated polymer were incubated in PBS buffer for 10 days. PBS was changed every 24 hours and concentrations of the antibiotics eluted into saline were quantified. Antimicrobial activity of the eluent from each sampling period was tested for growth inhibition of Staphylococcus aureus. Results: Both formulations of R‐gel? had a rapid initial release of antibiotics within the first 24 hours and then the concentrations decreased gradually over 10 days. The concentration of amikacin, clindamycin, and vancomycin remained above the breakpoint minimum inhibitory concentration of each drug for a minimum of 9 days. No significant difference (P=.9938, P=.9843) was present in the elution pattern or total amount of antibiotic eluted from clindamycin or amikacin, respectively. Eluent from both groups demonstrated bioactivity against S. aureus for the entire 10‐day study period. Conclusions: Amikacin and clindamycin together, or in combination with vancomycin, elute from R‐gel? effectively and at gradually decreasing concentrations for at least 10 days. The antibiotics maintained their bioactivity following polymerization and elution from the R‐gel?. 相似文献
94.
Fukuji TS Castro-Puyana M Tavares MF Cifuentes A 《Journal of agricultural and food chemistry》2011,59(22):11903-11909
A new method based on partial filling micellar electrokinetic chromatography (MEKC) for the quantitative determination of Sudan dyes (I, II, III, and IV) in chilli sauces is presented. The separation is achieved filling 25% of the capillary with a MEKC buffer composed of 40 mM NH(4)HCO(3), 25 mM sodium dodecyl sulfate, and 32.5% (v/v) acetonitrile (ACN). The rest of the capillary is filled using a capillary zone electrophoresis (CZE) buffer composed of 40 mM NH(4)HCO(3) and 32.5% (v/v) ACN. Under optimized conditions, the azo dyes are baseline separated in less than 8 min with limits of detection ranging from 0.57 to 0.71 μg mL(-1) (S/N > 3). Using an internal standard, the repeatability of the quantitative determination is improved almost four times. The applicability of the method for rapid screening and determination of Sudan dyes is corroborated by analyzing spiked chilli sauce samples with recoveries from 85 to 99%. The reported conditions are demonstrated to be compatible with mass spectrometry detection. 相似文献
95.
This paper attempts to evaluate the changes in the mechanical work of breathing induced by the increase of ventilation in ponies exercising on a treadmill. Airflow, tidal volume (VT) and oesophageal pressure were simultaneously recorded in eight ponies (four to six years old and weighing 258 +/- 11 kg) before, during and after standardised exercise. Respiratory frequency, VT and minute volume (Ve) for each phase of the experimental protocol were calculated from the collected data. The pressure-volume diagrams were traced and the work per cycle (Wrm) was estimated by measuring the area enclosed in the loop. The work per minute (Wrm) and the work per litre of ventilation (Wrm litre-1) were also calculated. From rest to fast trot Wrm litre-1, Wrm and Wrm had increased 8.1, 13.0 and 55.6 times, respectively. The relationships between Ve and Wrm litre-1 was linear and that between Ve and Wrm curvilinear. Results suggested that the mechanical cost of the work of breathing could be a limiting or at least a constraining factor of the increase of ventilation during strenuous exercise in ponies. 相似文献
96.
Ligands involved in Pb immobilization and transport in lettuce,radish, tomato and Italian ryegrass
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Luisa Massaccesi Carlo Meneghini Tatiana Comaschi Roberto D'Amato Andrea Onofri Daniela Businelli 《植物养料与土壤学杂志》2014,177(5):766-774
Lead (Pb) and other heavy metals represent a great source of concern in agriculture because they may disperse from polluted sources and accumulate in crop organs. This research study was performed with three edible crops and one pasture species (lettuce: Lactuca sativa L. cv. Romana; radish: Raphanus sativus L. var. radicicola; tomato: Lycopersicon lycopersicum L. Karst.; Italian ryegrass: Lolium multiflorum Lam). It was aimed at (1) assessing how species affect Pb distribution among plant organs, (2) determining the extent to which Pb is localized in edible organs, and (3) ascertaining whether it could be possible to distinguish which compounds are responsible for the transport of Pb from one plant organ to another and which compounds are responsible for the accumulation of this metal inside each plant organ. The experiment was conducted in the greenhouse. Plants were grown in plastic pots using a Pb‐spiked sandy soil as substrate. Total Pb concentrations in different plant organs and in soil were determined. Within plants, the maximum accumulation of Pb was found in roots while the remaining part of Pb was mainly located in leaves. Pb LIII edge XANES (X‐ray Absorption Near Edge Spectroscopy) was applied to identify the principal Pb carrier molecules in the different plant organs. The data suggest that in roots Pb immobilization is mainly due to the complexing ability of histidine, which binds the metal and, to a lesser extent, to precipitation of Pb as carbonate. The transport to the upper plant organs is mainly attributed to Pb complexes with organic acids. In stems and leaves, Pb bonding is mainly carboxylic and amino acid‐like, thus confirming the role of these substances in promoting Pb mobility. Thio amino acidic (glutathione and cysteine‐like) Pb complexes, which in this study were only found in stems, can also be held responsible for Pb long‐distance transport from roots to shoots. 相似文献
97.
Monika Höfer Henryk Flachowsky Magda-Viola Hanke Valentin Semënov Anna Šlâvas Irina Bandurko Artëm Sorokin Sergej Alexanian 《Genetic Resources and Crop Evolution》2013,60(4):1463-1477
Malus orientalis Uglitzk. is the predominant Malus species of the Caucasian forests distributed in the north of Anatolia, Armenia, Russia as well as in Iran. It is considered as one of the probable minor ancestors of domestic apples. Although M. orientalis has a lower diversity of fruit quality, other valuable traits such as later blooming, adaptation to a wider array of habitats, and capacity for longer storage of the apples should be taken into account for improving the genetic makeup of the domestic apple. A joint expedition of scientists of the Julius Kühn-Institute from Germany and the Nikolaj I. Vavilov Research Institute of Plant Industry from Russia was performed into the North Caucasus region during August/September 2011. Altogether 101 M. orientalis accessions were collected from eight sites at the North Caucasus. Twenty-six traits such as size, color, shape, flavor and firmness of fruit and tree habit were used for phenotypic evaluation of the accessions. A high phenotypic diversity within the collected material of M. orientalis was indicated. Accessions characterized by suitable fruit traits like bigger size, larger cover color, less bitterness and better firmness as well as more sweetness and better flavor were found. However, small-sized flavorless fruits were also detected. Tree habit varied widely from upright to weeping. Subsequently, a comprehensive phenotypic and genetic evaluation of M. orientalis increases the knowledge of diversity, may provide new resources of agronomically important traits for breeding purposes, and gives support to determine accessions for a core collection. 相似文献
98.
99.
Context
Regular mortality (or self-thinning) is an integral part of woody plant dynamics, and the mortality model is one of the most important transition functions within dynamic growth models.Aims
The main objectives of the present study were to derive one-step stand-level mortality models for estimating the reduction in stand density with stand dominant height growth and to examine the applicability of the models in predicting regular mortality trends in even-aged natural stands and plantations.Methods
Four model formulations based on graphical examination of the main trends in the data and on defined desired properties of the selected mathematical functions were proposed and tested in algebraic difference equation form with two datasets from pine plantations and two datasets from natural broadleaved even-aged stands.Results
The mortality patterns of three of the datasets were characterized by reverse sigmoid curves, while the forth dataset exhibited a reverse J-shaped trajectory. The models analyzed adequately represented the density decrease trends of the data through sets of polymorphic curves with multiple asymptotes.Conclusion
The dominant height-dependent mortality equations provide a simple and reliable approach to modeling the regular density decrease trends and can be considered for incorporation as a submodel within the framework of a dynamic Stand Density Management Diagram. 相似文献100.
Tatiana FigueiredoBruna Dzyekanski DVM Cláudia T. PimpãoAndressa B. Silveira DVM PhD Luiz G. CapriglionePedro Vicente Michelotto Jr. DVM MSc PhD 《Journal of Equine Veterinary Science》2013
Athletic horses often experience painful conditions of the musculoskeletal system, but their ability to compete can be prolonged using certain anesthetic agents. The present study investigated the ability of thermography to detect fetlock and middle carpal intrasynovial injections of bupivacaine hydrochloride in five mares. Saline injections were performed in the contralateral limbs. Thermographic evaluation was conducted at the dorsal and palmar aspects before (basal) and 15, 30, 60, 90, 120, and 1440 minutes after injection. The intrasynovial treatments resulted in increased limb temperature, with fetlock temperatures higher on the dorsal aspect at 15, 30, and 60 minutes and on the palmar aspect from 15 to 1440 minutes (P < .05) after the bupivacaine and saline injections. Increased carpal temperature was detected on the dorsal aspect at 60 and 90 minutes (P < .05). The present study demonstrates that thermography can be used to detect intrasynovial injections in horses. 相似文献