نتایج جستجو برای: marginal farms
تعداد نتایج: 63842 فیلتر نتایج به سال:
The aim of this research is to characterise the wild rabbit (Oryctolagus cuniculus) commercial game farms in Spain using variables related to structure, management and marketing. To this end, a structured survey was administered in 2009 to 21 privately-owned farms. This subsector was an average age of 13. The average size of the breeding stock of the farms was 431 does and 64 bucks. Eighty-five...
The purpose of this research was socioeconomicanalysis of farms using primary data in two villages of Mymensingh Sadar. A total of 60 farms including 20 small, 20 medium and 20 large were randomly selected for the study. Socioeconomic analysis showed that indebtedness was higher in large farms than those of small and medium ones. Large farms also engaged more in farm activities than others. All...
According to the authors, time-modified confounding occurs when the causal relation between a time-fixed or time-varying confounder and the treatment or outcome changes over time. A key difference between previously described time-varying confounding and the proposed time-modified confounding is that, in the former, the values of the confounding variable change over time while, in the latter, t...
Intensification and specialisation of agriculture in developed countries enabled productivity to be improved but had detrimental impacts on the environment and threatened the economic viability of a huge number of farms. The combination of livestock and crops, which was very common in the past, is assumed to be a viable alternative to specialised livestock or cropping systems. Mixed crop-livest...
OBJECTIVE We evaluated the epidemiology of antimicrobial resistance in enterococci from animal farms and the potential relation of resistance to antimicrobial use. METHODS Enterococci from faecal samples from 18 beef cattle, 18 dairy cattle, 18 swine, 13 chicken, and eight turkey farms were prospectively evaluated over a 6 year period from 1998 to 2003. RESULTS We evaluated 1256 isolates of...
where u ∼ N(0, G) and 2 ∼ N(0, R) with u and 2 independent. This model can be interpreted as Y |β, u ∼ N(Xβ+Zu,R), u ∼ N(0, G), yielding (on integrating out u) the marginal model Y |β ∼ N(Xβ,ZGZ + R). Let V = ZGZ + R. Then the maximum penalized likelihood estimates of β and u given G and R are given by θ̂ = [ β̂ û ] = (CTR−1C + B)−1CTR−1y (A.2) where C = [X Z] and B is the block diagonal matrix w...
Longitudinal studies, where data are repeatedly collected on one subject over a period, are common in medical research. When effect of a time-varying exposure on an outcome of interest is measured at different time points, standard statistical methods fail to give robust estimate in the presence of time-dependent confounders. There is alternative method avoid, that is, inverse probability weigh...
A concept known as ‘marginal gains’, an approach to performance improvement in elite sport came to prominence during the London 2012 Olympics when Team GB cycling won a record eight gold medals. Since National Lottery funding was awarded in 1997 to develop British cycling, the ethos of making aggregated small gains in many areas to improve overall performance has been central to its success. Th...
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The behavior of groups of housed, lactating dairy cattle was observed over 2 winter housing periods on 20 organic farms and 20 conventional farms in the United Kingdom. Three methods were used: (1) 6 video-clips of 10 min duration were captured of cows feeding at sections of the feed-bunk face during the peak feeding period (0 to 90 min) and continuously observed for aggressive interactions amo...
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