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51.
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Ingestion of man-made items by birds can reduce stomach volume and block the digestive track. In southern Africa, microtrash within the regurgitation of Cape Vulture nestlings was last documented in 1983. We present evidence of nestling microtrash ingestion after a 30-year gap. Vulture nestlings were captured at a breeding colony in the Eastern Cape, South Africa. One nestling regurgitated three microtrash fragments. Two pieces of microtrash were collected from the nest of another nestling. Neither nestling appeared to have skeletal deformities or feather stress bars. Our results highlight the persistence of microtrash ingestion by Cape Vulture nestlings, which could impact the species negatively. 相似文献
53.
Apoptosis is a highly regulated mode of cell death that occurs in the absence of inflammation. Light microscopic (LM) examination of the myocardium of apparently healthy camel did not reveal evidence of apoptosis in any samples; however, evidence of apoptosis was apparent by transmission electron microscopy (TEM). The most common apoptotic features observed by TEM included (1) an intact sarcolemma with some bleb formation; (2) nuclear chromatin condensation and margination with nucleolar disruption; (3) mitochondrial swelling and disorganization, accompanied by degeneration or hypercondensation of cristae; and (4) an intercalated disc region with a higher-than-normal mitochondrion/myofibril ratio, or surrounded from both sides by asymmetrically contracted sarcomeres. Apoptotic alterations were also noted among the endothelial cells lining the microvasculature of the myocardium. These alterations included (1) marked nuclear chromatin condensation and margination; (2) villous blebs on the adluminal plasmalemma, which projected into the lumen; (3) cytoplasmic vacuolation; (4) presence of intraluminal membrane-bounded vesicles; and (5) occasional pericapillary edema and accumulations of cellular debris. The results of this study indicate that myocardial apoptosis can occur in apparently healthy camels, in the absence of a clear-cut etiology. 相似文献
54.
The inhibiting effect of nitrate fertilisation on methane uptake of a temperate forest soil is influenced by labile carbon 总被引:1,自引:0,他引:1
Ann-Catrin Fender Birgit Pfeiffer Dirk Gansert Christoph Leuschner Rolf Daniel Hermann F. Jungkunst 《Biology and Fertility of Soils》2012,48(6):621-631
Upland soils are the most important terrestrial sink for the greenhouse gas CH4. The oxidation of CH4 is highly influenced by reactive N which is increasingly added to many ecosystems by atmospheric deposition and thereby also alters the labile C pool in the soils. The interacting effects of soil N availability and the labile C pool on CH4 oxidation are not well understood. We conducted a laboratory experiment with soil columns consisting of homogenised topsoil material from a temperate broad-leaved forest to study the net CH4 flux under the combined or isolated addition of NO 3 ? and glucose as a labile C source. Addition of NO 3 ? and glucose reduced the net CH4 uptake of the soil by 86% and 83%, respectively. The combined addition of both agents led to a nearly complete inhibition of CH4 uptake (reduction by 99.4%). Our study demonstrates a close link between the availability of C and N and the rate of CH4 oxidation in temperate forest soils. Continued deposition of NO 3 ? has the potential to reduce the sink strength of temperate forest soils for CH4. 相似文献
55.
56.
Experiments were conducted to study the effect of temperature and nutrition on seed germination and plant growth of different plant species. The nutrition studies of vegetables showed a normal response to fertilization rates on deficient soils at temperatures above their critical minimum. At soil temperatures below this little or no response was obtained to increased P concentration. Plant growth as affected by soil temperature was studied on beans, corn, cucumber, eggplant, pea, pepper, radish, spinach, and watermelon. Growth of peas, radish and spinach was significantly reduced by soil temperatures 10°C or lower. Corn growth was restricted when soil temperatures were maintained in the range of 12.3–14.5°C or lower, while growth of bean, cucumber, eggplant, pepper and watermelon was limited when soil temperatures were maintained in the 16.7–18.9°C temperature range or lower. 相似文献
57.
Menzies-Gow NJ Katz LM Barker KJ Elliott J De Brauwere MN Jarvis N Marr CM Pfeiffer DU 《The Veterinary record》2010,167(18):690-694
A retrospective study of laminitis was carried out to identify risk factors associated with this disease on an East Anglian farm with approximately 1000 animals living in an area of 1000 acres. Medical records between January 1997 and May 2000 and between April 2005 and March 2008 were reviewed, and the age, sex, weight (kg), height (inches [in] and hands [H]) and weight-to-height ratio (kg/in) was recorded. The prevalence, incidence and seasonality of laminitis were determined and their relationship to the monthly temperature, rainfall and hours of sunshine was evaluated. Averaged over the six years, the highest prevalence (2.6 per cent) and incidence (16 cases/1000 animals) of laminitis occurred in May. The findings of a multivariate analysis revealed that females (P=0.007, odds ratio [OR] 1.46, 95 per cent confidence interval [CI] 1.1053 to 1.9646) and light animals (P ≤ 0.001, OR=0.995, 95 per cent CI =0.9932 to 0.9963) had the greatest risk of developing laminitis. A positive association was found between hours of sunshine and incidence (P=0.007, relative risk [RR] 1.009, 95 per cent CI 1.001 to 1.012) and prevalence (P=0.002, RR 1.008, 95 per cent CI 1.003 to 1.012) of laminitis. The data suggest that there is a relationship between season, sex of the animal and the development of laminitis. 相似文献
58.
M. N. Inagaki W. H. Pfeiffer M. Mergoum A. Mujeeb-Kazi A. J. Lukaszewski 《Plant Breeding》1997,116(4):387-389
With the aim of producing polyhaploids of hexaploid triticale, 20 genotypes from a CIMMYT breeding programme and eight D-genome chromosome substitution lines of ‘Rhino’ were crossed with maize. In crosses between 20 triticale genotypes and maize, 15 lines produced embryos. Frequencies of embryo formation ranged from 0.0 to 5.4%, with an average of 1.1%. From a total of 200 pollinated spikes, 62 plants were regenerated. Most regenerated plants were polyhaploids with 21 chromosomes, and few aneuhaploids with 22 chromosomes were found. In crosses of triticale substitution lines with maize, all the lines produced embryos, while ‘Rhino’ produced no embryos at all. Higher frequencies of embryo formation were obtained in substitution lines with chromosomes 2D and 4D. These results suggest that D-genome chromosomes in a triticale genetic background have the effect of increasing the frequency of polyhaploid production in triticale x maize crosses. 相似文献
59.
Allan FJ Pfeiffer DU Jones BR Esslemont DH Wiseman MS 《Preventive veterinary medicine》2000,46(3):183-196
This study was done to identify risk factors for obesity in an urban cat population in New Zealand. A door-to-door survey (conducted within the city limits of Palmerston North) obtained information on the diet, health and behaviour of 202 cats. One hundred and eighty-two of these cats were weighed and their back and leg lengths were measured. The interviewer's assessment of the body condition of each cat was the dependent variable used in this study. Variables that were identified as significant (p< or =0.1) following univariable analysis were grouped into one of the three models for stepwise logistic multiple regression (one each for cat characteristics, environmental and management variables and feeding variables). A combined logistic-regression analysis was performed on the significant variables identified from the three component models. In the combined model, only three variables were significant: the presence of dogs in a household (decreased odds of obesity), longer leg length and owners underestimating cats' body condition (both increased odds). 相似文献
60.
Spatial epidemiological tools are increasingly being applied to emerging viral zoonoses (EVZ), partly because of improving analytical methods and technologies for data capture and management, and partly because the demand is growing for more objective ways of allocating limited resources in the face of the emerging threat posed by these diseases. This review documents applications of geographical information systems (GIS), remote sensing (RS) and spatially-explicit statistical and mathematical models to epidemiological studies of EVZ.Landscape epidemiology uses statistical associations between environmental variables and diseases to study and predict their spatial distributions. Phylogeography augments epidemiological knowledge by studying the evolution of viral genetics through space and time. Cluster detection and early warning systems assist surveillance and can permit timely interventions. Advanced statistical models can accommodate spatial dependence present in epidemiological datasets and can permit assessment of uncertainties in disease data and predictions. Mathematical models are particularly useful for testing and comparing alternative control strategies, whereas spatial decision-support systems integrate a variety of spatial epidemiological tools to facilitate widespread dissemination and interpretation of disease data. Improved spatial data collection systems and greater practical application of spatial epidemiological tools should be applied in real-world scenarios. 相似文献