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101.
102.
B. Louise Chilvers Ian S. Wilkinson Darryl I. Mackenzie 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(2):259-278
The trade-off between survival and reproduction by individuals is central to understanding life-history parameters of a species.
Few mammal species have life-history information from long-term research. Instead, demographic models are commonly utilized
to investigate an individual’s life-history strategy, species dynamics, and population trends. This research investigates
age-related survival and reproductive performance of adult female New Zealand (NZ) sea lions (Phocarctos hookeri), using multi-state mark-recapture data from known-age branded individuals over five years. The mark-recapture analysis was
integrated with a population model to predict the lifetime reproductive output of female NZ sea lions. The integration of
an analysis of short-term datasets with population modeling allows for the prediction of life-history parameters of long lived
animals when long-term information is not available. While such approaches involve some caveats, it provides a framework for
investigating population dynamics and is preferential to unsubstantiated assumptions. This technique can lead to better design
and implementation of conservation management for long lived species. 相似文献
103.
白蚁是世界性害虫。不少种类对森林、房屋建筑、电讯设备、水库土坝等造成严重危害。利用金龟子绿僵菌(Metarhizium anisopliae)防治白蚁,已有不少研究。本文提出绿僵菌感染白蚁生物测定新方法,比以往的方法更省时。试验以象白蚁(Nasutitermes exitiosus)作供试昆虫,但也适用于对其它白蚁的研究。 相似文献
104.
Effectiveness of steam pasteurization in controlling microbiological hazards of cull cow carcasses in a commercial plant
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Harold Corantin Sylvain Quessy Marie-Lou Gaucher Louise Lessard Danielle Leblanc Alain Houde 《Canadian journal of veterinary research》2005,69(3):200-207
The purpose of the study, carried out in a beef processing plant, was to evaluate the effectiveness of a new prototype for steam pasteurization treatment in controlling microbiological hazards. Samples were taken by swabbing randomly selected sites before and after pasteurization and again after chilling to obtain total aerobic counts (TAC), total coliform counts (TCC), and generic Escherichia coli counts (ECC) on Petrifilm plates and to determine the prevalence of Salmonella spp., Listeria monocytogenes, and E. coli O157:H7 using standard enrichment techniques. Escherichia coli and L. monocytogenes strains were tested for various factors associated with their virulence by using colony hybridization and polymerase chain reaction (PCR), respectively. Antimicrobial susceptibility was determined for each isolate that was potentially pathogenic to humans by using the disk-diffusion method. Mean values for TAC, TCC, and ECC were 2.18, 0.16, and 0.06 log10 CFU/cm2, respectively, before pasteurization; 1.17, 0.03, and 0.01 log10 CFU/cm2 after pasteurization; and 0.89, 0.02, and 0.01 log10 CFU/cm2 after chilling. Prevalence of L. monocytogenes, Salmonella spp., and E. coli O157:H7 on carcasses was 0.8%, 0.0%, and 0.0%, respectively, before pasteurization; 2.6%, 0.0%, and 0.0% after pasteurization; and 3.1%, 0.1%, and 0.0% after chilling. The prevalence of E. coli containing > or = 1 virulence gene was 14.7%. More specifically, 11.88% of the isolates obtained before pasteurization, 22.2% obtained after pasteurization, and 31.2% obtained after chilling had virulence genes. All L. monocytogenes isolates tested positive for the presence of 3 major virulence factors (hlyA, inlB, and plcB). Antibiograms showed that certain isolates were susceptible to all antibiotics, some showed an intermediate sensitivity, and others were multiresistant. Overall, these results suggest that steam pasteurization is an effective means of improving safety quality of beef carcasses. However, pasteurization may indirectly contribute to the growth of some pathogenic microorganisms, such as L. monocytogenes. 相似文献
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106.
An exploration of the drivers to bio-security collective action among a sample of UK cattle and sheep farmers 总被引:1,自引:0,他引:1
At present, collective action regarding bio-security among UK cattle and sheep farmers is rare. Despite the occurrence of catastrophic livestock diseases such as bovine spongiform encephalopathy (BSE) and foot and mouth disease (FMD), within recent decades, there are few national or local farmer-led animal health schemes. To explore the reasons for this apparent lack of interest, we utilised a socio-psychological approach to disaggregate the cognitive, emotive and contextual factors driving bio-security behaviour among cattle and sheep farmers in the United Kingdom (UK). In total, we interviewed 121 farmers in South-West England and Wales. The main analytical tools included a content, cluster and logistic regression analysis.The results of the content analysis illustrated apparent ‘dissonance’ between bio-security attitudes and behaviour.1 Despite the heavy toll animal disease has taken on the agricultural economy, most study participants were dismissive of the many measures associated with bio-security. Justification for this lack of interest was largely framed in relation to the collective attribution or blame for the disease threats themselves. Indeed, epidemic diseases were largely related to external actors and agents. Reasons for outbreaks included inadequate border control, in tandem with ineffective policies and regulations. Conversely, endemic livestock disease was viewed as a problem for ‘bad’ farmers and not an issue for those individuals who managed their stock well. As such, there was little utility in forming groups to address what was largely perceived as an individual problem.Further, we found that attitudes toward bio-security did not appear to be influenced by any particular source of information per se. While strong negative attitudes were found toward specific sources of bio-security information, e.g. government leaflets, these appear to simply reflect widely held beliefs. In relation to actual bio-security behaviours, the logistic regression analysis revealed no significant difference between in-scheme and out of scheme farmers.We concluded that in order to support collective action with regard to bio-security, messages need to be reframed and delivered from a neutral source. Efforts to support group formation must also recognise and address the issues relating to perceptions of social connectedness among the communities involved. 相似文献
107.
108.
Louise L. Southwood BVSc MS PhD DACVS DACVECC Gail Russell BS 《Journal of Veterinary Emergency and Critical Care》2007,17(4):382-390
Objective: To compare clinical findings in horses/foals with peritonitis that: (1) had no concurrent (NCA) versus a concurrent abnormality found during hospitalization, (2) survived to discharge versus did not survive to discharge, and (3) survived to discharge without surgery versus did not survive to discharge without surgery. Design: Retrospective study. Setting: George D. Widener Hospital for Large Animals at New Bolton Center. Animals: Horses/foals admitted between 1992 and 2002 with a diagnosis of peritonitis. A diagnosis of peritonitis within 4 days of presentation and peritoneal fluid nucleated cell count >10,000/μL were required for study inclusion. Horses/foals were excluded if the peritonitis was secondary to gastrointestinal or reproductive tract perforation, a complication of exploratory celiotomy, or if peritonitis was not diagnosed until surgery or necropsy. Interventions: None. Measurements and main results: Information obtained from the medical records included clinical findings at presentation and during the initial 4 days of hospitalization. Outcome was defined as: (1) NCA (yes/no), (2) survived to discharge (yes/no), and (3) survived to discharge without surgery (yes/no). Forty‐two percent (23/55) of horses/foals had NCA; 78% (43/55) survived to discharge, and 68% (36/55) survived to discharge without surgery. Horses/foals with peritonitis that had any one of the following clinical findings were likely to survive to discharge without surgery: no signs of abdominal pain, normal/improved rectal temperature, normal/improved intestinal borborygmi, normal fecal production, no abnormal findings on abdominal palpation per rectum, no nasogastric reflux, or yellow/orange peritoneal fluid. Conclusion: Clinical findings can be used to identify equine peritonitis cases that will respond favorably to medical therapy. 相似文献
109.
Storage of ‘McIntosh’ Apples (Malus domestica Borkh.) in a controlled atmosphere (CA) with very low O2 (1.5% CO2 + 1.0% O2, 2.8°C) retained greater fruit firmness and titratable acids during storage and during subsequent air storage than apples stored in conventional CA (5.0% CO2 + 3.0% O2, 2.8°C). The rate of firmness loss during subsequent 0°C air storage decreased with length of storage in CA. Storage of apples in very low O2 for 40 or 80 days decreased the rate of firmness loss in subsequent 0°C air storage as compared to the rate of firmness loss in conventional CA fruit, but the rate of firmness loss in 0°C air storage subsequent to 160 or 320 days of conventional CA was significantly less than the loss in similar fruit stored in very low O2 atmospheres.A modified atmosphere with 1.0% O2 decreased the rate of C2H4 accumulation in storage, and fruit production of both C2H4 and CO2 after storage opening in comparison with similar fruit in conventional CA. The accumulation of C2H4 in storage chambers was increased with increasing O2 levels, but the rate of increase depended upon the CO2 level. C2H4 storage accumulation was stimulated by the presence of CO2 at 0.5% O2, but was suppressed by CO2 when 3.0% O2 was maintained.Retention of fruit firmness and titratable acids in apples stored in 1.5% CO2 + 1.0% O2 were insensitive to very low (0.231 ml l?1) or very high (2440 ml l?1) C2H4 levels in storage. Scrubbing C2H4 (0.304 ml l?1) from chambers held at 5.0% CO2 + 3.0% O2 resulted in significantly firmer fruit after storage, but this effect was not significant after shelf life of 7 days at 20°C. 相似文献
110.