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61.
Morrica P Trabue S Anderson JJ Lawler S Seccia S Fidente P Swain RS Mattson SL 《Journal of agricultural and food chemistry》2004,52(1):99-104
The kinetics and mechanism(s) of the hydrolytic degradation of a compound are needed to evaluate a compound's abiotic degradation in the environment. In this paper, the hydrolysis of cymoxanil [2-cyano-N-[(ethylamino)carbonyl]-2-(methoxyimino) acetamide] was investigated in dark sterile aqueous solutions under a variety of pH conditions (pH 2.8-9.2) and temperatures (15-50 degrees C). Hydrolysis of cymoxanil was described by first-order kinetics, which was dependent on pH and temperature. Cymoxanil degraded rapidly at pH 9 (half-life = 31 min) and relatively slowly at pH 2.8 (half-life = 722 days). The effect of temperature on the rate of cymoxanil degradation was characterized using the Arrhenius equation with an estimated energy of activation of 117.1 kJ mol(-)(1). An increase in temperature of 10 degrees C resulted in a decrease in half-life by a factor of approximately 5. Three competing degradation pathways are proposed for the hydrolysis of cymoxanil, with two of the pathways accounting for approximately 90% of cymoxanil degradation. These two pathways involved either initial cyclization to 1-ethyldihydro-6-imino-2,3,5(3H)-pyrimidinetrione-5-(O-methyloxime) (1, Figure 1) or direct cleavage of the C-1 amide bond to form cyano(methoxyimino) acetic acid (7). The third pathway of degradation involved initial cyclization to 3-ethyl-4-(methoxyimino)-2,5-dioxo-4-imidazolidinecarbonitrile (8), which rapidly degrades into 1-ethyl-5-(methoxyimino)-2,4-imidazoline-2,4-dione (9). All three pathways eventually lead to the formation of the polar metabolite oxalic acid. 相似文献
62.
Gene regulation at the single-cell level 总被引:1,自引:0,他引:1
63.
A.?D.?AggelopoulouEmail author D.?Bochtis S.?Fountas K.?C.?Swain T.?A.?Gemtos G.?D.?Nanos 《Precision Agriculture》2011,12(3):448-456
It has been suggested that apple (
Malus * domestica Borkh) flowering distribution maps can be used for site-specific management decisions. The objectives of this study were
(i) to study the flower density variability in an apple orchard using image analysis and (ii) to model the correlation between
flower density as determined from image analysis and fruit yield. The research was carried out in a commercial apple orchard
in Central Greece. In April 2007, when the trees were at full bloom, photos of the trees were taken following a systematic
uniform random sampling procedure. In September 2007, yield mapping was carried out measuring yield per ten trees and recording
the position of the centre of the ten trees. Using this data (the measured yield of the trees and the pictures samples, representing
the flower distribution), an image processing-based algorithm was developed that predicts tree yield by analyzing the picture
of the tree at full bloom. For the evaluation of the algorithm, a case study scenario is presented where the error of the
predicted yield was set at 18%. These results indicated that potential yield could be predicted early in the season from flowering
distribution maps and could be used for orchard management during the growing season. 相似文献
64.
65.
Swain JE 《The Journal of reproduction and development》2011,57(4):551-555
Elevated CO(2) is required for in vitro embryo culture to maintain proper media pH and to supply embryo metabolic pathways. As an alternative to current approaches using gas cylinders, we examined use of a chemical reaction to supply CO(2). A closed culture system was constructed and chemicals added to generate CO(2), which was then supplied to developing embryos. This system was shown to provide a stable pH (7.2-7.4) over 4 days of use. One-cell mouse embryos were cultured in the device and no difference in blastocyst formation or cell number was apparent between embryos grown in a closed system with CO(2) supplied by a chemical reaction or positive controls grown in a an open system in a CO(2) incubator. This approach provides a highly purified, inexpensive, and easily obtainable gas source and offers potential for development of new, self-contained culture platforms. 相似文献
66.
Gaddamidi V Scott MT Swain RS Macpherson D Lowrie C 《Journal of agricultural and food chemistry》2011,59(4):1316-1323
Metabolism of [(14)C]chlorantraniliprole {3-bromo-N-[4-chloro-2-methyl-6-[(methylamino)carbonyl]phenyl]-1- (3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxamide} was investigated in a lactating goat following seven consecutive daily single oral doses. Each dose was equivalent to 10.4 mg/kg of feed. There was no significant transfer of residues of either chlorantraniliprole or its metabolites into fat, meat, or milk. Chlorantraniliprole and its metabolites accounted for 93.57% of the administered dose and were eliminated primarily in the excreta. Residues in meat, milk, liver, and kidney together accounted for ca. 1.5% of the administered radioactivity. A total of 19 metabolites including 3 glucuronide conjugates and intact chlorantraniliprole were identified in the feces, urine, or tissues by comparison of their HPLC retention times, mass spectral fragments (LC-MS/MS), or multiple reaction monitoring (MRM) transitions to authentic synthesized standards. The major metabolic pathways of [(14)C]chlorantraniliprole in the goat were N-demethylation, methylphenyl hydroxylation, and further oxidation to the carboxylic acid; loss of water from the N-hydroxymethyl group to yield various cyclic metabolites; and hydrolysis of N-methyl amides to form benzoic acid derivatives. Minor metabolic reactions involved cleavage of the amide bridge between the phenyl and heterocyclic rings of chlorantraniliprole. 相似文献
67.
D.D. Bochtis C.G. Sørensen R.N. Jørgensen M. Nørremark I.A. Hameed K.C. Swain 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):202-208
Abstract In this paper, an integrated management system for the planning and activation of a field monitoring task is presented. The architecture of the system is built around a mobile robotic unit. The internet-based architecture of the system includes a station unit that works as a mobile on-farm operating console, the mobile robotic unit and a field server for generating and storing maps. The hypothesis is that it is possible to automate the planning and execution of the operation of monitoring the in-field weed density and species distribution. The developed planning system includes the automatic field geometrical representation and the route planning for the mobile unit. For the field representation two algorithmic approaches for automated track generation were used. For the route planning, a graph-based field coverage algorithm and a discrete grid-based path planning method were used. The low computational requirements of the implemented algorithms make it feasible to adopt a real-time re-planning strategy in which a set of new planning problems are solved based on the latest information. The central part of such a planning, concerns the dynamic re-evaluation of the initial plan for sampling and routing based on the on-line analysis of the samples. This provides the basis for a fully sequential adaptive adjustment of the sampling procedure after each individual sampling. It is expected that such a dynamic targeted sampling and routing system will reduce the overall cost and time consumption of the weed monitoring operation. 相似文献
68.
Dilip K. Swain Mohar Singh Kushwah Mandheer Kaur Tapas K. Patbandha Ashok K. Mohanty Ajay K. Dang 《Veterinary research communications》2014,38(3):209-219
Neutrophils employ both oxidative and non oxidative mechanisms to destroy pathogens. Function of neutrophils coming in milk during mammary invasion is not clearly understood in dairy animals. Therefore, the present study was designed in 36 Sahiwal cows to see the changes occurring in the neutrophil activity of cows suffering from subclinical (SCM) and clinical mastitis (CM). Cows were divided into three groups as healthy (n?=?12), SCM (n?=?12) and CM (n?=?12) groups on the basis of CMT scoring, gross morphological changes in milk, bacteriological examination of milk and by counting milk SCC. Significantly (P?0.05) higher milk SCC, neutrophil percent and significantly (P?0.05) lower viability of both blood and milk neutrophils were observed in CM group of cows as compared to SCM and control group of cows. Phagocytic activity (PA) was significantly (P?0.05) higher in milk neutrophils of SCM and CM cows as compared to control cows. Toll like receptors 2 and 4 in blood and milk neutrophils were found to be significantly (P?0.05) higher, whereas, apoptosis in terms of altered mitochondrial transmembrane potential, Caspase 3 and 7 activities were found to be significantly (P?0.05) lower in CM cows. Alterations in surface architecture of neutrophils in terms of formation of pseudopods was observed by scanning electron microscope (SEM) and found to be higher in CM cows. Blood neutrophils were found to be spherical as compared to milk neutrophils. Formation of neutrophil extracellular trap (NETs) were found milk neutrophils of CM cows, whereas, SCM and healthy cows did not exhibit NET formation. The study indicated a positive correlation between lower neutrophil apoptosis and higher expression of TLR2 and TLR4 with the formation of NETs and change in surface architecture. Formation of NET like structures seemed to be an effective mode of defense employed by neutrophils of cows suffering from clinical mastitis. 相似文献
69.
Bluetongue virus: European Community inter-laboratory comparison tests to evaluate ELISA and RT-PCR detection methods 总被引:1,自引:0,他引:1
Batten CA Bachanek-Bankowska K Bin-Tarif A Kgosana L Swain AJ Corteyn M Darpel K Mellor PS Elliott HG Oura CA 《Veterinary microbiology》2008,129(1-2):80-88
European Community national reference laboratories participated in two inter-laboratory comparison tests in 2006 to evaluate the sensitivity and specificity of their 'in-house' ELISA and RT-PCR assays for the detection of bluetongue virus (BTV) antibodies and RNA. The first ring trial determined the ability of laboratories to detect antibodies to all 24 serotypes of BTV. The second ring trial, which included both antisera and EDTA blood samples from animals experimentally infected with the northern European strain of BTV-8, determined the ability of laboratories to detect BTV-8 antibodies and RNA, as well as the diagnostic sensitivity of the assays. A total of six C-ELISAs, six real-time RT-PCR and three conventional RT-PCR assays were used. All C-ELISAs were capable of detecting the BTV serotypes currently circulating in Europe (BTV-1, 2, 4, 8, 9 and 16), however some assays displayed inconsistencies in the detection of other serotypes, particularly BTV-19. All C-ELISAs detected BTV-8 antibodies in cattle and sheep by 21 dpi, while the majority of assays detected antibodies by 9 dpi in cattle and 8 dpi in sheep. All the RT-PCR assays were able to detect BTV-8, although the real-time assays were more sensitive compared to the conventional assays. The majority of real-time RT-PCR assays detected BTV RNA as early as 2 dpi in cattle and 3 dpi in sheep. These two ring trails provide evidence that national reference laboratories within the EC are capable of detecting BTV antibodies and RNA and provide specificity and sensitivity information on the detection methods currently available. 相似文献
70.
L. R. Williams E. L. Jackson G. J. Bishop‐Hurley D. L. Swain 《Journal of animal physiology and animal nutrition》2017,101(6):1076-1092
This study used a systematic literature review methodology to determine whether there is evidence that drinking frequency has effects on cattle performance, what performance responses to drinking frequency are documented and how performance responses vary according to environmental and animal factors. Electronic databases were searched for English language articles with original data on at least one performance attribute (e.g. water intake, feed intake, live weight) of cattle in response to voluntary drinking frequency or controlled access periods to water. Sixteen experiments on dairy cows and 12 experiments on beef cattle were retrieved from the literature. For beef cattle, all experiments reported reduced water and feed intake with access to water once every second and/or third day compared with once‐daily access. Median reductions of 15% and 25% in water intake and 16% and 9% in feed intake were found across experiments respectively. Live weight responses of beef cattle to access to water were limited and yielded positive, negative and no effects. For dairy cows, most experiments reported reduced water intake, milk yield and milk fat content with access to water twice or once daily compared with controls (ad libitum or ad libitum except at the dairy). Median reductions of 13% and 12% in water intake, 2% and 1% in milk yield and 1% and 2% in milk fat content were found across experiments respectively. Water availability effects on feed intake and live weight were very limited for dairy cows and yielded positive, neutral and negative effects. Season, climate, experiment conditions, animal class and animal genotype were identified to potentially influence intake responses of cattle. The review highlights a number of important gaps in the literature where future work is required to better understand the optimum drinking frequency of cattle and implications of water availability on health, welfare and performance. 相似文献