共查询到20条相似文献,搜索用时 31 毫秒
1.
Anna Ohlson Ulf Emanuelson Madeleine Tråvén Stefan Alenius 《Acta veterinaria Scandinavica》2010,52(1):37
Background
Bovine respiratory syncytial virus (BRSV) and bovine corona virus (BCV) affects cattle worldwide. Our objective was to evaluate the effects of these infections on general health and reproduction parameters measurable on herd level and to explore the association between antibody status and some herd characteristics. 相似文献2.
Background
Genotype by environment interactions are currently ignored in national genetic evaluations of dairy cattle. However, this is often questioned, especially when environment or herd management is wide-ranging. The aim of this study was to assess genotype by environment interactions for production traits (milk, protein, fat yields and fat and protein contents) in French dairy cattle using an original approach to characterize the environments.Methods
Genetic parameters of production traits were estimated for three breeds (Holstein, Normande and Montbéliarde) using multiple-trait and reaction norm models. Variables derived from Herd Test Day profiles obtained after a test day model evaluation were used to define herd environment.Results
Multiple-trait and reaction norm models gave similar results. Genetic correlations were very close to unity for all traits, except between some extreme environments. However, a relatively wide range of heritabilities by trait and breed was found across environments. This was more the case for milk, protein and fat yields than for protein and fat contents.Conclusions
No real reranking of animals was observed across environments. However, a significant scale effect exists: the more intensive the herd management for milk yield, the larger the heritability. 相似文献3.
Kenji Sato Paul C Bartlett Lis Alban Jens F Agger Hans Houe 《Acta veterinaria Scandinavica》2008,50(1):4
Background
Several management and environmental factors are known as contributory causes of clinical mastitis in dairy herd. The study objectives were to describe the structure of herd-specific mastitis management and environmental factors and to assess the relevance of these herd-specific indicators to mastitis incidence rate. 相似文献4.
Marie Jansson Mörk Ulf Emanuelson Ann Lindberg Ivar Vågsholm Agneta Egenvall 《Acta veterinaria Scandinavica》2009,51(1):34
Background
Research has indicated that a number of different factors affect whether an animal receives treatment or not when diseased. The aim of this paper was to evaluate if herd or individual animal characteristics influence whether cattle receives veterinary treatment for disease, and thereby also introduce misclassification in the disease recording system. 相似文献5.
Background
Expression array data are used to predict biological functions of uncharacterized genes by comparing their expression profiles to those of characterized genes. While biologically plausible, this is both statistically and computationally challenging. Typical approaches are computationally expensive and ignore correlations among expression profiles and functional categories. 相似文献6.
Background
An ever increasing number of techniques are being used to find genes with similar profiles from microarray studies. Visualization of gene expression profiles can aid this process, potentially contributing to the identification of co-regulated genes and gene function as well as network development. 相似文献7.
8.
Egil Simensen Olav Østerås Knut Egil Bøe Camilla Kielland Lars Erik Ruud Geir Næss 《Acta veterinaria Scandinavica》2010,52(1):14
Background
According to the Norwegian animal welfare regulations, it has been forbidden to build new tie-stall barns since the end of 2004. Previous studies have shown that cow performance and health differ between housing systems. The interaction between housing system and herd size with respect to performance and disease incidence has not been evaluated. 相似文献9.
Background
Profile-profile methods have been used for some years now to detect and align homologous proteins. The best such methods use information from the background distribution of amino acids and substitution tables either when constructing the profiles or in the scoring. This makes the methods dependent on the quality and choice of substitution table as well as the construction of the profiles. 相似文献10.
Miguella P Mark-Carew Yasin Khan Susan E Wade Stephanie Schaaf Hussni O Mohammed 《Acta veterinaria Scandinavica》2010,52(1):44
Background
The primary aims of this study were to determine the incidence of Giardia infections in dairy herds on farms in the New York City Watershed region and to evaluate risk factors associated with infections. Because co-infections of Giardia and Cryptosporidium spp. are common in this population, we also evaluated the effect of herd infection status on Giardia infections. 相似文献11.
Methods
In this study, proteomics methods have been used to study the effects of different currents and voltages used to stun chickens. Protein profiles of chicken hearts were constructed to detect differences in protein expression and modification. The different voltages studied were 10 V, 40 V and 70 V, while the currents examined were 0.25 A, 0.5 A, and 0.75 A. The profiles obtained from these stunning conditions were compared to the non-stunned (0 A, 0 V) sample. 相似文献12.
Background
Large biological data sets, such as expression profiles, benefit from reduction of random noise. Principal component (PC) analysis has been used for this purpose, but it tends to remove small features as well as random noise. 相似文献13.
Steffie K. Naber Suzette M. Matthijsse Kirsten Rozemeijer Corine Penning Inge M. C. M. de Kok Marjolein van Ballegooijen 《PloS one》2016,11(1)
Background
Vaccination against the oncogenic human papillomavirus (HPV) types 16 and 18 will reduce the prevalence of these types, thereby also reducing cervical cancer risk in unvaccinated women. This (measurable) herd effect will be limited at first, but is expected to increase over time. At a certain herd immunity level, tailoring screening to vaccination status may no longer be worth the additional effort. Moreover, uniform screening may be the only viable option. We therefore investigated at what level of herd immunity it is cost-effective to also reduce screening intensity in unvaccinated women.Methods
We used the MISCAN-Cervix model to determine the optimal screening strategy for a pre-vaccination population and for vaccinated women (~80% decreased risk), assuming a willingness-to-pay of €50,000 per quality-adjusted life year gained. We considered HPV testing, cytology testing and co-testing and varied the start age of screening, the screening interval and the number of lifetime screens. We then calculated the incremental cost-effectiveness ratio (ICER) of screening unvaccinated women with the strategy optimized to the pre-vaccination population as compared to with the strategy optimized to vaccinated women, assuming different herd immunity levels.Results
Primary HPV screening with cytology triage was the optimal strategy, with 8 lifetime screens for the pre-vaccination population and 3 for vaccinated women. The ICER of screening unvaccinated women 8 times instead of 3 was €28,085 in the absence of herd immunity. At around 50% herd immunity, the ICER reached €50,000.Conclusion
From a herd immunity level of 50% onwards, screening intensity based on the pre-vaccination risk level becomes cost-ineffective for unvaccinated women. Reducing the screening intensity of uniform screening may then be considered. 相似文献14.
Jorn R De Haan Ester Piek Rene C van Schaik Jacob de Vlieg Susanne Bauerschmidt Lutgarde MC Buydens Ron Wehrens 《BMC bioinformatics》2010,11(1):158
Background
Gene expression data can be analyzed by summarizing groups of individual gene expression profiles based on GO annotation information. The mean expression profile per group can then be used to identify interesting GO categories in relation to the experimental settings. However, the expression profiles present in GO classes are often heterogeneous, i.e., there are several different expression profiles within one class. As a result, important experimental findings can be obscured because the summarizing profile does not seem to be of interest. We propose to tackle this problem by finding homogeneous subclasses within GO categories: preclustering. 相似文献15.
Background
The prevalence of pleurisies recorded at slaughter is increasing in Sweden, and acute outbreaks of actinobacillosis that require antimicrobial treatments have become more frequent. As an increased use of antimicrobials may result in the development of antimicrobial resistance it is essential to develop alternative measures to control the disease. Vaccinations present an appealing alternative to antimicrobial treatments. The aim of this work was to evaluate the potential of two different vaccination strategies in a specialized fattening herd affected by actinobacillosis. 相似文献16.
Background
Amino acid sequence probability distributions, or profiles, have been used successfully to predict secondary structure and local structure in proteins. Profile models assume the statistical independence of each position in the sequence, but the energetics of protein folding is better captured in a scoring function that is based on pairwise interactions, like a force field. 相似文献17.
Ryoko Morioka Shigehiko Kanaya Masami Y Hirai Mitsuru Yano Naotake Ogasawara Kazuki Saito 《BMC bioinformatics》2007,8(1):343
Background
Modelling of time series data should not be an approximation of input data profiles, but rather be able to detect and evaluate dynamical changes in the time series data. Objective criteria that can be used to evaluate dynamical changes in data are therefore important to filter experimental noise and to enable extraction of unexpected, biologically important information. 相似文献18.
Background
Xenotransplantation has drawn increased attention in recent years as a potential solution to the scarcity of human source donor organs. Researchers have highlighted the need to characterize the influence of porcine endogenous retroviruses (PERV) in xenotransplantation. Screening and analyzing the presence and subtype of PERV in donor source animal breeds could provide basic parameters to evaluate the biological safety of xenotransplantation from pigs to humans. We bred a new miniature porcine herd (XENO-1) after decades of investigation, the herd was purpose bred to produce a potential donor animal source for xenotransplantation. To this end we studied the animals’ PERV expression characteristics.Methods
We randomly selected 37 animals of the herd, PCR and RT-PCR based on specific primers were utilized to determine their PERV viral subtype. High fidelity PCR and restriction enzyme digestion were employed for variants detection. To thoroughly understand the PERV expression pattern, quantitative PCR was applied to measure mRNA expression levels in different tissues, At last, transfection capacity was assessed using a in vitro co-culture system.Results
Our results revealed that the XENO-1 herd was free of PERV-C and exhibited low levels of PERVs in different tissues compared to commercial pig (landrace). The XENO-1 herd showed unique variants of A/B recombination. In addition, even though there were A/B variants in the XENO-1 herd, co-culturing revealed no evidence of PERV transmission from XENO-1 tissue to human cells.Conclusion
Overall, Our results displayed an unique PERV expression pattern in a new pig herd and demonstrated its non-transfection capacity in vitro. Data in the research indicate that XENO-1 animals can serve as a better potential donor source for xenotransplantation.19.
Background
Tiling array data is hard to interpret due to noise. The wavelet transformation is a widely used technique in signal processing for elucidating the true signal from noisy data. Consequently, we attempted to denoise representative tiling array datasets for ChIP-chip experiments using wavelets. In doing this, we used specific wavelet basis functions, Coiflets, since their triangular shape closely resembles the expected profiles of true ChIP-chip peaks. 相似文献20.