Lower temperatures delayed development of systemic symptoms by Cauliflower mosaic virus (CaMV) in two different plant hosts. However, lower temperature exposure increased CaMV nucleic acid levels in leaves of systemically-infected turnips. Furthermore, lower temperature altered the formation of aggregates formed by the CaMV major inclusion body (IB) protein, P6. Finally, lower temperature altered the architecture of the actin cytoskeleton. These data may suggest that lower temperatures alter the actin cytoskeleton, facilitating the formation of larger IBs that hold on to their internal virions more strongly than small ones, impairing virus particle release and causing a delay in systemic infection.
Using a radial immunodiffusion assay, total bile and serum IgG, IgM and IgA were measured following primary and secondary exposures to Eimeria tenella. Neither IgG nor IgM could be detected consistently in bile. Biliary IgA peaked at Days 6 and 10 following a primary infection of either 5000 or 10,000 oocysts and remained elevated following a subsequent 10,000-oocyst challenge at Day 10. Serum IgG and IgM levels were not influenced by parasitism and measurable concentrations of serum IgA were not detected. 相似文献
The purpose of this study was to determine the best method to ultrasonographically monitor renal size changes associated with acute allograft rejection in dogs. Qualitative changes in renal cortical and medullary echogenicity were also evaluated, although this was not a major focus of the study. Four unrelated, mixed-breed dogs underwent bilateral nephrectomies and heterotopic renal allograft transplantation. Ultrasound examinations of transplanted kidneys were initiated at 3 days after surgery and continued at 2–3 day intervals until death (38±2 days). Ultrasound measurements of kidney length, width, height, cross-sectional area, and estimated volume were used to assess relative changes in renal size associated with transplantation and rejection. Transplanted kidneys had a rapid increase in volume and cross-sectional area that averaged 103% and 83% above baseline levels, respectively, by 17 days after transplantation. The increased size was attributed to a combination of hypertrophy and acute rejection, the latter of which was confirmed at postmortem. Kidney volume decreased to approximately 35% above baseline volume by day 34 as rejection became more advanced. Qualitative changes associated with rejection included medullary enlargement with decreased echogenicity early in the study, followed by increased cortical thickness and echogenicity with poor cortical medullary definition in the latter stages of the survival period. It was concluded that relative changes in renal allograft size can be easily monitored with ultrasound. In regard to linear measurements, changes in renal width were more pronounced than changes in height or length with acute rejection. Therefore measurements that incorporate the width, namely volume or cross-sectional area, appear to be the most sensitive for monitoring changes in allograft size. Renal cross-sectional area measurements are preferred because they are simple to perform using the automated calculation capability of most newer ultrasound units. 相似文献
Despite its vigor, agrifood studies research faces two fault lines: the durability of disciplines, and challenges in engaging
non-academic stakeholders. In this essay, I use the concept of boundary work from social studies of science and technology
to reflect on the challenges and opportunities for more engaged interdisciplinary research in agrifood studies. I draw on
recent field visits to several “sustainable food chain” research projects funded through the Rural Economy and Land Use Programme
(RELU), an innovative interdisciplinary research initiative of the UK Research Councils, to highlight the contradictory nature
of boundary work in interdisciplinary research. Involving efforts both to bridge interfaces and to separate, exclude and manage
other disciplines or stakeholders, boundary work is inherent to interdisciplinarity. Innovations in the organizational culture
of projects and in the larger structural context for research can multiply the more generative potential of boundary work,
and also yield more and better interdisciplinary research in agrifood studies.
Arabidopsis thaliana accessions have adapted to growth in a wide range of climates. Variation in flowering and alignment of vernalization response with winter length are central to this adaptation. Vernalization involves the epigenetic silencing of the floral repressor FLC via a conserved Polycomb (PRC2) mechanism involving trimethylation of Lys(27) on histone H3 (H3K27me3). We found that variation for response to winter length maps to cis polymorphism within FLC. A rare combination of four polymorphisms localized around the nucleation region of a PHD-Polycomb complex determines a need for longer cold. Chromatin immunoprecipitation experiments indicate that these polymorphisms influence the accumulation of H3K27me3 in Arabidopsis accession Lov-1, both at the nucleation site and over the gene body. Quantitative modulation of chromatin silencing through cis variation may be a general mechanism contributing to evolutionary change. 相似文献
The purpose of this study was to evaluate 55 clinical cases of canine demodicosis and to compare the results of treatment using amitraz (solution), selamectin (spot-on), ivermectin (injection) and cythioate (oral tablets). Data from the 55 cases was collected and evaluated after clinical and microbiological examination. Treatment was selected depending on the severity of demodicosis and compliance of the owner. The cases were followed for 12 months and the status of the patients was grouped on two levels: recovered (58%), or relapsed (42%). Five dogs (9%) were euthanized. The disease was commonly diagnosed in purebred dogs. Demodicosis was more common in dogs under 2 years of age (65%), in males (64%), and in the short-haired breeds (75%). Demodicosis was generalized in 73% of cases, localised in 23% and affected the feet (pododemodicosis) in 4% of cases. Recovery was the highest in dogs between 1 and 2 years of age (73%), and in the localized cases (92%). Nonspecific treatment with glucocorticoids prior to the diagnosis lowered the rate of recovery (4%), but treatment with glucocorticoids for proven atopic dermatitis improved the rate of recovery (41%). All drugs (amitraz, selamectin, cythioate) administered for the localized form were effective (100% recovered). Recovery in generalized demodicosis was 60% using ivermectin, 55% using amitraz, 44% with the combination of amitraz and selamectin (two treatments with amitraz followed by selamectin), and 43% in cases where selamectin was used alone. Funding: Pfizer Animal Health. 相似文献
OBJECTIVE: To evaluate whether consumption of breakfast cereals is associated with BMI in a sample of Greek adolescents. DESIGN: A cross-sectional health and nutrition survey.Setting and subjectsDuring 200417 years were selected from twelve schools located in Vyronas region (Athens metropolitan area). Height and weight were measured and BMI was calculated. A semi-quantitative FFQ was applied and multiple logistic regression analysis was used. RESULTS: Overall, 47 % of girls were obese, whereas 192 % of girls were overweight. Only 205 % of girls reported that they consume cereals as a first choice for breakfast. Consumption of breakfast cereals was associated with lower BMI in boys (P = 0019), irrespective of age and physical activity status. More prominent results were observed for daily cereal consumption or for more than two daily servings of cereals consumed for breakfast. Consumption of pre-sweetened breakfast cereals was associated with lower BMI compared with non-pre-sweetened or no intake of cereals, in both genders (P < 0.001). Consumption of breakfast cereals was associated with 33 % (95 % CI 14 %, 48 %) lower likelihood of overweight/obesity, irrespective of age, sex and physical activity status. CONCLUSIONS: Consumption of breakfast cereals was associated with lower BMI levels and a lower likelihood of overweight/obesity in both genders; thus a solid basis for public health professionals could be built when issuing advice on weight management. 相似文献
The accurate estimation of livestock weights is important for many aspects of livestock management including nutrition, production and appropriate dosing of pharmaceuticals. Subtherapeutic dosing has been shown to accelerate pathogen resistance which can have subsequent widespread impacts. There are a number of published models for the prediction of live weight from morphometric measurements of cattle, but many of these models use measurements difficult to gather and include complicated age, size and gender stratification. In this paper, we use data from the Infectious Diseases of East Africa calf cohort study and additional data collected at local markets in western Kenya to develop a simple model based on heart girth circumference to predict live weight of east African shorthorn zebu (SHZ) cattle. SHZ cattle are widespread throughout eastern and southern Africa and are economically important multipurpose animals. We demonstrate model accuracy by splitting the data into training and validation subsets and comparing fitted and predicted values. The final model is weight0.262?=?0.95?+?0.022 × girth which has an R2 value of 0.98 and 95 % prediction intervals that fall within the ±20 % body weight error band regarded as acceptable when dosing livestock. This model provides a highly reliable and accurate method for predicting weights of SHZ cattle using a single heart girth measurement which can be easily obtained with a tape measure in the field setting. 相似文献
Intertidal habitat maps are needed at both fine and coarse scales to monitor change and inform conservation and management, but current methods of field survey and expert interpretation of aerial imagery can be time‐consuming and subjective. Object‐based image analysis (OBIA) of remote sensing data is increasingly employed for producing habitat or land cover maps. Users create automated workflows to segment imagery, creating ecologically meaningful objects, which are then classified based on their spectral or geometric properties, relationships to other objects and contextual data.
This study evaluates the change‐detection capability of OBIA in the intertidal environment by developing and comparing two OBIA methods for quantifying change in extent and distribution of habitats from freely available multi‐temporal aerial imagery and LiDAR data. Despite considerable variability in the data, pre‐ and post‐classification change detection methods had sufficient accuracy (mean overall accuracy from 70.5 to 82.6%) to monitor deviation from a background level of natural environmental fluctuation.
This insight into spatial and temporal patterns of natural cyclical change and their detectability by OBIA could inform use of remote sensing for regular, rapid coastal assessment, providing an alert system to direct survey resources to areas of ecologically relevant change.