The impact of agricultural extension services on social capital: an application to the Sub-Saharan African Challenge Program in Lake Kivu region     

Fédes van Rijn  Ephraim Nkonya  Adewale Adekunle 《Agriculture and Human Values》2015,32(4):597-615

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Casein hydrolyzate intramammary treatment improves the comfort behavior of cows induced into dry-off     

Gabriel Leitner  Shamay Jacoby  Ephraim Maltz  Nissim Silanikove   《Livestock Science》2007,110(3):292-297

The effectiveness of casein hydrolyzate as mean to improve the welfare of cows induced into involution was tested in high yielding cows induced into dry-off by abrupt cessation of milking. Treatment with casein hydrolysate prevented build up of udder pressure in cows induced into dry off and was clearly associated with signs (lying behavior and step numbers) that they were calmer and more comfortable than cows induced into dry off by the conventional means. We conclude that treatment with casein hydrolyzate is a viable treatment tool that can prevent the suffering associated with drying-off of high-yielding modern dairy cows.  相似文献   

Toxicity of azinphos-methyl to various development stages of the codling moth Cydia pomonella (Lepidoptera: Tortricidae)     

Reuveny H  Cohen E 《Pest management science》2007,63(2):129-133

The response to azinphos-methyl of different life-stages of the codling moth Cydia pomonella (L.) was studied. A similarity in response to azinphos-methyl (LC(50), LC(90)) was observed in neonate larvae obtained from the first and second generations of field populations. Mortality rates for neonate larvae of a field population cross-bred with a laboratory colony were lower (by a factor of 1.2-2.2) in comparison with field neonate larvae. The mortality rate of larvae from a laboratory colony exposed to artificial diet containing azinphos-methyl gradually decreased at older instars. The mortality rates of fifth-instar larvae were remarkably low when exposed to artificial diet mixed with azinphos-methyl or when topically treated with the insecticide. One- to three-day-old females were more sensitive than males of the same age, whereas the opposite was observed in 14-to 17-day-old adults. Mortality rates of 14- to 17-day-old adults were higher than those under 10 days old. No significant difference in sensitivity to the organophosphorus compound was noticed between the sexes of 7- to 10-day-old adults. Neonate larvae of the codling moth can serve as a target life-stage for various groups of pesticides, and the importance of using such a stage as a standardized methodology for monitoring resistance in the codling moth is discussed.  相似文献   

Evaluation of head-out constant volume body plethysmography for measurement of specific airway resistance in conscious, sedated sheep     

Bedenice D  Bar-Yishay E  Ingenito EP  Tsai L  Mazan MR  Hoffman AM 《American journal of veterinary research》2004,65(9):1259-1264

OBJECTIVE: To evaluate the use of a modified whole body plethysmograph in awake sheep. ANIMALS: 10 healthy adult sheep. PROCEDURE: Concurrent measurements of specific airway resistance (sR(aw)) and pulmonary resistance (R(L)) were obtained using a novel noninvasive head-out constant-volume plethysmograph and esophageal balloon-pneumotachography, respectively. All data were collected before and after external resistive loading with 1 and 5.6 cm H2O/L/s. Functional residual capacity (FRC) was measured by helium dilution for computation of airway resistance (R(aw)) preloading (R(aw) = sR(aw)/FRC). RESULTS: The sR(aw) and R(L) were closely correlated in 10 adult sheep. Additionally, sR(aw), and R(L) accurately reflected the magnitude of added resistance. The mean FRC was 52 mL/kg and used to calculate R(aw). At baseline, the values for R(aw) were significantly correlated with sR(aw) and R(L). CONCLUSIONS AND CLINICAL RELEVANCE: Precise measurements of sR(aw) and R(aw) at baseline and sR(aw) after external resistive loading were obtained by use of this novel noninvasive plethysmographic technology. This method should have application to veterinary patients or animals used in research in which noninvasive rapid or serial measurements of sR(aw) in the conscious state are required.  相似文献   

Steam treatment to prevent carrot decay during storage     

Uzi Afek  Janeta Orenstein  Ephraim Nuriel 《Crop Protection》1999,18(10):265-642

Organically grown carrots (Daucus carota L.) have a relatively short storage and shelf life, mainly because chemical measures cannot be implemented to control plant pathogens. Laboratory experiments demonstrated that steam treatments substantially reduced decay of stored organically grown carrots. Prior to being packaged, winter carrots were exposed to 3 s of steam. After 60 days of storage at 0.5°C plus an additional week at shelf conditions (20°C), 2% of the carrots were decayed, as opposed to 23% in the nontreated control. When carrot was inoculated with the fungi Alternaria alternata, [(Fr. : Fr.) Keissler] A. radicina (Meier) and Sclerotinia sclerotiorum [(Lib.) De Bary], percentages of decay, after similar periods of storage and shelf life, were 5% for steam-treated carrot and 65% for the nontreated control. In semi-commercial experiments carrots were treated with steam during the sorting process, and similar results were obtained. Higher decay was found in spring-grown carrots because of the presence of the bacterium Erwinia carotovora.sub. sp. carotovora  相似文献   

Agent-Based Inference for Animal Movement and Selection     

Mevin B. Hooten  Devin S. Johnson  Ephraim M. Hanks  John H. Lowry 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(4):523-538

Contemporary ecologists often find themselves with an overwhelming amount of data to analyze. For example, it is now possible to collect nearly continuous spatiotemporal data on animal locations via global positioning systems and other satellite telemetry technology. In addition, there is a wealth of readily available environmental data via geographic information systems and remote sensing. We present a modeling framework that utilizes these forms of data and builds on previous research pertaining to the quantitative analysis of animal movement. This approach provides additional insight into the environmental drivers of residence and movement as well as resource selection while accommodating path uncertainty. The methods are demonstrated in an application involving mule deer movement in the La Sal Range, Utah, USA. Supplemental materials for this article are available online.  相似文献   

Inhibition of Tribolium gut chitin synthetase     

Ephraim Cohen  John E. Casida 《Pesticide biochemistry and physiology》1980,13(2):129-136

The chitin synthetase (CS) of Tribolium castaneum gut is inhibited 50% by 0.02 μM nikkomycin and 4 μM polyoxin D, two pyrimidine nucleoside fungicides, in in vitro assays with 10-min preincubation of enzyme and inhibitor prior to substrate addition. Tribolium CS is also sensitive to inhibition by the pyrimidine nucleotides uridine and cytidine di- and triphosphates. Captan, a known inhibitor of insect chitin synthesis, and the related fungicides captafol and dichlofluanid are highly potent inhibitors of Tribolium CS. Moderately active CS inhibitors are the acaricide oxythioquinox and the herbicide barban. One phenylcarbamate insect growth reatardant, H-24108, is weakly active in inhibiting Tribolium gut CS, as are three of its analogs but not 26 others. Many triazines are not inhibitory including several herbicides and an azido derivative, CGA 19255, which is active in blocking insect growth and chitin synthesis. Although the benzoylphenyl urea insecticides diflubenzuron and SIR 8514 are potent in vivo inhibitors of the polymerization step in insect chitin synthesis, they do not affect T. castaneum gut CS activity in vitro and greatly stimulate Tribolium brevicornis gut CS activity in vivo. These studies and preliminary findings on an integumental enzyme indicate that CS of these tissues is not sensitive to the direct action of benzoylphenyl ureas. This leads to speculation that the benzoylphenyl ureas act either as CS inhibitors via active metabolites formed in the integument or as blocking agents by direct binding to non-CS sites important in chitin polymerization and fibrillogenesis.  相似文献   

Photostabilization of bioresmethrin by organic cations on a clay surface     

Leon Margulies  Ephraim Cohen  Harel Rozen 《Pest management science》1987,18(2):79-87

Photostabilization of the pyrethroid insecticide bioresmethrin (BR) was achieved by adsorbing it onto the ciay montmorillonite with a cationic organic chromophore. Experiments in the dark showed that adsorption of BR to the surface of the clay did not inhibit its insecticidal activity. Complexes containing the organic cations methyl green (MG) or naphthylammonium (NA) retained their insecticidal activity against the flour beetle, Tribolium castaneum for 3-5 days in sunlight whereas unprotected BR was inactivated within a few hours. Optimum stabilization was achieved by definite amounts of BR and MG adsorbed, indicating that photostabilization was due to specific intermolecular interactions on the clay surface rather than to a UV-screening effect. The interactions between BR and MG at the clay surface were studied by Fourier transform infra-red spectroscopy.  相似文献   

Application of a dot enzyme-linked immunosorbent assay for evaluation of the immune status to canine parvovirus and distemper virus in adult dogs before revaccination.   总被引：1，自引：0，他引：1  

Trevor Waner  Shlomit Mazar  Ephraim Keren-Kornblatt 《Journal of veterinary diagnostic investigation》2006,18(3):267-270

A growing body of literature has been published indicating that the current practice of annual vaccination of dogs may not be beneficial and in some cases may even be harmful. A number of publications have proposed assessing the immune status of dogs before annual revaccination. In this study the usefulness of a commercially available dot-ELISA kit was evaluated to determine the duration IgG antibody titers to canine parvovirus (CPV) and canine distemper virus (CDV) in 158 dogs vaccinated at least one year ago. Overall, the percentage of dogs with protective antibody titers to both CPV and CDV was 84%. The percentage of dogs with borderline antibody titers was 11% for CPV and 10% for CDV. Four percent of the dogs had no detectable antibody to CPV and 6% had no antibody to CDV. The results reported here are in good agreement with other studies measuring IgG antibody levels. It is concluded that the kit offers veterinarians the opportunity of determining antibody titers and revaccinating only those pets whose antibody titers to specific diseases have waned.  相似文献   

Properties and inhibition of insect integumental chitin synthetase     

Ephraim Cohen  John E. Casida 《Pesticide biochemistry and physiology》1982,17(3):301-306

Chitin polymerization is catalyzed by cell-free enzyme complexes from the integument of Trichoplusia ni larvae and wing tissue of developing Hyalophora cecropia pupae obtained on extraction of homogenates for 16 hr at 5°C in 25 mM Tris-HCl buffer, pH 7.2, containing 10 mM MgCl₂, 1 mM dithiothreitol, 10 mg/ml bovine serum albumin, and 4 mg/ml digitonin. In contrast, integumental preparations from Boarmia selenaria, Earias insulana, Heliothis virescens, Oncopeltus fasciatus, Spodoptera exigua, and Tribolium castaneum exhibit little or no chitin synthetase (CS) activity. H. cecropia CS requires magnesium ions but not N-acetyl-d-glucosamine for normal activity and is almost insensitive to nikkomycin and polyoxin D. CS activity is not detected in diapausing H. cecropia pupae but synthesis of this enzyme is induced or its activity is stimulated by the molting hormone, ecdysterone, indicating possible hormonal control. T. ni CS requires magnesium ions and N-acetyl-d-glucosamine for optimal activity and is sensitive to inhibition by uridine di- and triphosphates, polyoxins B and D, and particularly nikkomycin. T. ni integumental CS activity decreases in starved larvae or those about to pupate. Both T. ni and H. cecropia CS enzymes as prepared and assayed are sensitive to captan but not to the potent insecticides diflubenzuron and BAY SIR 8514, two effective benzoylphenyl urea in vivo chitin synthesis inhibitors.  相似文献