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31.
Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic gamma radiation [50 grays (Gy) per hour] or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared with radiation-sensitive bacteria and that resistance exhibits a concentration-dependent response to manganous chloride [Mn(II)]. Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus, and cyanobacteria accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high iron but low intracellular manganese concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.  相似文献   
32.
Evolutionary social psychology and family homicide   总被引:2,自引:0,他引:2  
Homicide is an extreme manifestation of interpersonal conflict with minimal reporting bias and can thus be used as a conflict "assay." Evolutionary models of social motives predict that genetic relationship will be associated with mitigation of conflict, and various analyses of homicide data support this prediction. Most "family" homicides are spousal homicides, fueled by male sexual proprietariness. In the case of parent-offspring conflict, an evolutionary model predicts variations in the risk of violence as a function of the ages, sexes, and other characteristics of protagonists, and these predictions are upheld in tests with data on infanticides, parricides, and filicides.  相似文献   
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Fifteen influenza-naive Welsh mountain ponies were randomly assigned to three groups of five. A single dose of a recombinant ALVAC vaccine was administered intramuscularly to five of the ponies, two doses, administered five weeks apart, were administered to five, and the other five served as unvaccinated, challenge controls. Two weeks after the completion of the vaccination programme, the ponies were all challenged by exposure to an aerosol of influenza virus A/eq/Newmarket/5/03. Their clinical signs were scored daily for 14 days according to a standardised scoring protocol, and nasal swabs were taken daily for 10 days to monitor the excretion of virus. The challenge produced severe clinical signs of influenza (fever, coughing, nasal discharge and dyspnoea) in all five control ponies, but the vaccinated ponies developed only mild disease, consisting of a serous nasal discharge lasting for only one day. The excretion of virus was almost completely suppressed in the vaccinated ponies, but the control ponies shed the virus for up to seven days after the challenge.  相似文献   
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OBJECTIVE: To examine the effect on wool growth of physiological changes associated with experimental flystrike in superfine Merino wethers. DESIGN: An animal house study comparing experimentally fly struck sheep with non-infected control groups that were pair fed or fed ad libitum. PROCEDURE: Sheep in the blow fly larval challenge group were each artificially infected with 500 first instar larvae per day for 8 days. Infections were terminated with insecticide on day 10. For all sheep, live weight change, feed intake and body temperature were monitored and blood collected for analysis of haematology, cortisol, serum haptoglobin, serum amyloid A and the pro-inflammatory cytokines, TNFa, IL-1 b, IL-6 and IL-8. Wool growth and staple strength were examined 4 months after infection. RESULTS: Experimental fly strike included moderate fever, depressed feed intake, and elevated cortisol, IL-6, serum amyloid A and haptoglobin. Staple strength was significantly decreased in struck sheep and did not differ between wool from sites adjacent to and remote from strike lesions. CONCLUSIONS: The results suggest that depression in feed intake alone is not sufficient to account for the decline in staple strength seen during fly strike. Cortisol, IL-6 and metabolic consequences of the acute phase response are likely to be major contributors to the systemic effects of blowfly strike on wool.  相似文献   
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SUMMARY The polymerase chain reaction was used to detect the presence of blue-tongue virus (BTV) in a number of clinical and insect samples collected in the Northern Territory of Australia. Sequence analyses of the amplified BTV genes differentiated endemic Australian and exotic viruses. Two potential exotic BTV were detected as a result of PCR analyses of blood from sentinel animals and of the insect vector, Culicoides wadai. The detection of BTV in C wadai was the first direct demonstration of the presence of BTV in this potential vector. This new technology can significantly reduce the time taken for a diagnosis from a clinical sample and increase the amount of useful information obtained on a BTV isolate by using rapid sequencing techniques. Sequence data were used to differentiate between BTV20 isolated in 1975 and two isolates of the same serotype, isolated in 1992, and indicated that the latter were probably a recent incursion into Australia from Indonesia due to their greater VP3 sequence homology to the BTV9 (Java) than to Australian BTV isolates.  相似文献   
39.
Outbreaks of human salmonellosis associated with live poultry contact have been reported since 1955. Multiple Salmonella serotypes have been associated with these outbreaks, and specific outbreak strains have been repeatedly linked to single hatcheries over multiple years. During 2009, four multistate outbreaks of human Salmonella infections associated with direct and indirect exposure to live poultry purchased from mail-order hatcheries and agricultural feed stores were identified, resulting in 165 culture-confirmed cases in 30 states. This report describes the epidemiologic, environmental and laboratory investigations conducted by state and local health departments, state departments of agriculture, the U.S. Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), National Poultry Improvement Plan (NPIP) and National Veterinary Services Laboratories (NVSL), and the Centers for Disease Control and Prevention (CDC). Case-patients were identified through PulseNet, the national molecular subtyping network for foodborne disease surveillance, and interviewed using the CDC standard live poultry contact questionnaire that asks about poultry-related exposures during the 7 days before illness onset. These outbreaks highlight the need to focus efforts on strategies to decrease and prevent human illness associated with live poultry contact through comprehensive interventions at the mail-order hatchery, agricultural feed store and consumer levels. Additional consumer education and interventions at mail-order hatcheries and venues where live poultry are sold, including agricultural feed stores, are necessary to prevent transmission of Salmonella from poultry to humans.  相似文献   
40.
An 8-year-old, male castrated golden retriever presented for cough and increased respiratory effort. Radiographs revealed an alveolar pattern in the right caudal lung lobe and an opacity at the carina suspected to be enlarged tracheobronchial lymph nodes. The disease progressed to involve the right middle lung lobe. Cytopathology of a fine-needle aspirate and bronchoalveolar lavage fluid were nondiagnostic. Surgical removal of the right caudal lung lobe and biopsy of the perihilar lymph nodes revealed pulmonary thromboembolism and reactive lymph nodes. The dog died several days postoperatively, and necropsy revealed diffuse pulmonary thromboembolism. Additionally, Blastomyces dermatitis organisms were identified in a pyogranulomatous mass surrounding the trachea near the carina. In an extensive literature search, no reports of pulmonary thromboembolism associated with blastomycosis were identified. It is suspected that the inflammation secondary to blastomycosis caused the thromboembolism.  相似文献   
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