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61.
The psyllid Macrohomotoma gladiata, is a new insect pest of Ficus originating from Asia which has recently been found in Spain (Alicante) on urban Ficus microcarpa trees. This species may be of phytosanitary concern because of its leaf wrapping habits, wax secretion and honeydew excretion that may lead to direct and secondary twig damage. Although more studies are needed on the biology of M. gladiata, it is suspected that it might behave in the Euro‐Mediterranean as an invasive alien species. The predation by Anthocoris sp. (nemoralis?) needs to be investigated in order to assess its effectiveness as a natural biological control agent. This is the first report of M. gladiata from the EPPO region. 相似文献
62.
Nam SW Chung HS Lo YC Qi L Li J Lu Y Johnson AT Jung Y Nukala P Agarwal R 《Science (New York, N.Y.)》2012,336(6088):1561-1566
Phase-change materials undergo rapid and reversible crystalline-to-amorphous structural transformation and are being used for nonvolatile memory devices. However, the transformation mechanism remains poorly understood. We have studied the effect of electrical pulses on the crystalline-to-amorphous phase change in a single-crystalline Ge(2)Sb(2)Te(5) (GST) nanowire memory device by in situ transmission electron microscopy. We show that electrical pulses produce dislocations in crystalline GST, which become mobile and glide in the direction of hole-carrier motion. The continuous increase in the density of dislocations moving unidirectionally in the material leads to dislocation jamming, which eventually induces the crystalline-to-amorphous phase change with a sharp interface spanning the entire nanowire cross section. The dislocation-templated amorphization explains the large on/off resistance ratio of the device. 相似文献
63.
Dirikolu L Lehner AF Karpiesiuk W Hughes C Woods WE Boyles J Harkins JD Troppmann A Tobin T 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(3):257-268
Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates. 相似文献
64.
65.
Luisa Garofalo Angela Mastrogiacomo Paolo Casale Rossella Carlini Claudia Eleni Daniela Freggi Donatella Gelli Leyla Knittweis Carmen Mifsud Toni Mingozzi Nicola Novarini Dino Scaravelli Giovanni Scillitani Marco Oliverio Andrea Novelletto 《水产资源保护:海洋与淡水生态系统》2013,23(6):868-884
- that the north Adriatic, the Tunisian continental shelf, the waters around Malta and the Italian Ionian Sea represent important areas for the conservation of rookeries in Greece, Libya and Turkey, respectively;
- that waters off the Italian peninsula and the islands of Lampedusa and Malta are mainly inhabited by individuals of Mediterranean origin, with a major contribution from the nearest and largest colonies, while Atlantic turtles are restricted to the western areas;
- that specific migratory routes exist from rookeries to foraging grounds;
- a poor bi‐parental genetic structuring, which suggests a high male‐mediated gene flow in the Mediterranean;
- mixing of small turtles in waters distant from natal rookeries, and recovery of structuring for large‐sized individuals; and
- that uncommon mtDNA haplotypes are more powerful markers than microsatellite alleles in assessing an individual's origin, owing to their higher geographic specificity.
66.
Rogelberg SG Reeve CL Spitzmüller C DiGiacomo N Clark OL Teeter L Walker AG Starling PG Carter NT 《Journal of the American Veterinary Medical Association》2007,230(5):713-719
OBJECTIVE: To examine the effects of euthanasia rates, euthanasia practices, and human resource practices on the turnover rate among employees with euthanasia responsibilities at animal shelters. DESIGN: Cross-sectional original study. SAMPLE POPULATION: 36 shelters across the United States that employed at least 5 full-time employees and performed euthanasia on site. PROCEDURES: By mail, 1 survey was sent to each shelter. Surveys were completed by a senior member of management and were returned by mail. Questions assessed characteristics (eg, euthanasia rates) and practices of the animal shelter, along with employee turnover rates. By use of correlation coefficients and stepwise regression analyses, key predictors of turnover rates among employees with euthanasia responsibilities were investigated. RESULTS: Employee turnover rates were positively related to euthanasia rate. Practices that were associated with decreased turnover rates included provision of a designated euthanasia room, exclusion of other live animals from vicinity during euthanasia, and removal of euthanized animals from a room prior to entry of another animal to be euthanized. Making decisions regarding euthanasia of animals on the basis of factors other than behavior and health reasons was related to increased personnel turnover. With regard to human resources practices, shelters that used a systematic personnel selection procedure (eg, standardized testing) had comparatively lower employee turnover. CONCLUSIONS AND CLINICAL RELEVANCE: Data obtained may suggest several specific avenues that can be pursued to mitigate turnover among employees with euthanasia responsibilities at animal shelters and animal control or veterinary medical organizations. 相似文献
67.
Trees within the homestead area provide many functions to rural households. However, within the semi-arid regions of southern
Africa, there has been only limited examination of the correlates between the socio-economic attributes of rural households
and the density, species richness and types of trees they keep. This paper reports on a multivariate analysis of household
attributes in relation to homestead tree holdings from six rural villages in South Africa. In terms of density of trees per
household, gender of the household head was the only significant correlate, with female-headed households having significantly
fewer trees than their male-headed counterparts. This was especially so for the density of indigenous trees. With respect
to species richness, a number of interrelated correlates were identified through Principle Components Analysis, the most prominent
ones being relative wealth, village location, homestead size and gender. Most species were common between both male- and female-headed
households, although there were differences between them for six of the species held by at least five percent of households.
However, the differences were not related to species uses or income generation potential. These results indicate that support
programmes should be conscious of the differential needs and responses of households according to their different characteristics
and circumstances. 相似文献
68.
Greening of shopping centre parking lots is a potentially important strategy that can contribute to urban carbon mitigation efforts, improve aesthetics and the shopping experience of consumers, whilst adding to urban biodiversity. Twenty-eight shopping centre parking lots in six Eastern Cape urban centres, South Africa, were sampled to determine tree species composition, density and annual carbon sequestration potential. The best case parking lot found during the study was used as a benchmark to display the difference between current tree density and above-ground carbon stocks relative to the potential optimum. The highest tree density was 66 trees ha?1, whereas the average density across all sampled parking lots was less than half that (27.2 ± 22.6 trees ha?1). The average annual carbon sequestration potential per parking lot was 1390 ± 2503 kg ha?1. Planting density was positively related to annual sequestration rates, whilst parking lot age and the mean annual rainfall of the town had no influence. Mean tree species richness per parking lot was 2.3 ± 1.8 species, with a positive relationship to parking lot size, but not to mean annual rainfall of the site. The majority of trees (62.5%) in parking lots were alien species, although newer parking lots had significantly greater proportions of indigenous species. There was no difference in mean annual carbon sequestration rate per tree between indigenous and alien trees species. Low tree densities and small parking lot areas constrained the potential for earning carbon credits from trees in parking lots. Nonetheless, planners and designers need to be more aware of the potential contribution of trees towards urban sustainability. 相似文献
69.
Production Characteristics of All‐male and Mixed‐sex Giant River Prawns,Macrobrachium rosenbergii,Grown in Earthen Ponds in Kentucky and Mississippi USA 下载免费PDF全文
James H. Tidwell Louis R. D'Abramo Shawn D. Coyle Leigh A. Bright Charlie Shultz Zachary Kupchinsky Pamela Schwartz Craig Upstrom 《Journal of the World Aquaculture Society》2015,46(2):139-148
Production and population characteristics of monosex male (all‐male) giant river prawns, Macrobrachium rosenbergii, were compared with a normal (mixed‐sex) population in separate studies in Mississippi and Kentucky (USA) under low and high density stocking conditions, respectively. In Study 1 (Mississippi), juvenile prawns were stocked into eight 0.05–0.06 ha ponds at 24,700/ha. The mean stocking weight of all‐male was 0.34 g and mixed‐sex was 0.39 g. Prawns were fed 23% crude protein “range cubes” and harvested after 120 d for the all‐male prawns and 112 d for mixed‐sex prawns. In Study 2 (Kentucky), juvenile prawns from each group were stocked into six 0.04 ha ponds at 60,000 juveniles per hectare. The mean stocking weight for all‐male was 0.38 g and for mixed‐sex juveniles was 0.34 g. Prawns were fed a commercial sinking pellet (33% protein) once daily at a standardized rate and harvested after 105 d. In both locations survival of mixed‐sex prawns and all‐male prawns was not significantly different and the final average weight of all‐male prawns was significantly greater than the average weight of mixed‐sex prawns. For the study in Kentucky, total production was not significantly different between treatments, whereas in Mississippi total production in the all‐male ponds was significantly higher than in the mixed‐sex ponds. For both studies, the production size index of all‐male prawns was significantly greater than that of mixed‐sex prawns. In terms of population structure, in all‐male ponds there was a significant increase in orange claw (OC) males compared with the mixed‐sex ponds both as a percent of sex and a percent of total population. The increase in OC numbers in all‐male populations may be due to a lack of females to stimulate the transition of males to the final, sexually mature, blue claw stage. As target weights increase from 20, 30, and 40 g, the all‐male populations were increasingly superior in terms of production (kg/ha) of those target sizes. The economic benefit of all‐male over mixed‐sex populations will be principally based on an examination of tradeoffs that primarily consider the cost difference of juveniles relative to the price differences for different final harvest weights. 相似文献
70.
José F. Barbosa-Neto Wilawan Siripoonwiwat Louise S. O'Donoughue Stewart M. Gray Down M. Smith Fred L. Kolb Catherine Gourmet Charlie M. Brown Mark E. Sorrells 《Euphytica》2000,114(1):67-76
Immature embryos of the spring barley variety GoldenPromise, were bombarded with three different particledelivery systems and both transient and stabletransformation examined. In addition, a range oftechniques for the preparation of the DNA coated goldparticles was examined. Fertile transgenic barleyplants were obtained using three particle preparationtechniques which differed in the amount of gold andDNA used for each bombardment. However, only one ofthe particle delivery systems, the PDS 1000/He device,appeared to be effective in yielding transformedbarley plants. 相似文献