568 research outputs found
Evaluation of the epidemiological importance of classical swine fever infected, E2 sub-unit marker vaccinated animals with RT-nPCR positive blood samples
<p>It has been demonstrated that pigs that have been double vaccinated with an E2 sub-unit marker vaccine and that are infected with classical swine fever virus (CSFV) through a natural contact infection may react positive in a CSFV detecting RT-nPCR test, whereas no virus could be isolated by using the conventional virus isolation (VI) technique. To evaluate whether these vaccinated and infected pigs may spread the virus, three experiments were set up. In the first, susceptible pigs were inoculated with serum originating from vaccinated RT-nPCR positive pigs. In the second, vaccinated RT-nPCR positive pigs were brought into contact with sentinel animals. In the third, vertical transmission was evaluated in RT-nPCR positive vaccinated pregnant gilts. In the first two experiments, no proof of virus transmission was found, whereas in the third vertical transmission was observed. The conclusion is that in vaccinated pigs that are positive in RT-nPCR but negative in VI, the level of circulating virus is probably not high enough for horizontal transmission, whereas vertical transmission of the virus is possible.</p></p
Deconstructing the Subject Condition in terms of cumulative constraint violation
Chomsky (1973) attributes the island status of nominal subjects to the Subject Condition, a constraint specific to subjects. English and Spanish are interesting languages for the comparative study of extraction from subjects, because subjects in English are predominantly preverbal, whereas in Spanish they can be either preverbal or postverbal. In this paper we argue that the islandhood of subject DPs in both English and Spanish is not categorical. The degradation associated with extraction from subjects must be attributed to the interplay of a range of more general constraints which are not specific to subjects. We argue that the interaction of these constraints has a cumulative effect whereby the more constraints that are violated, the higher the degree of degradation that results. We also argue that some speakers have a greater tolerance for constraint violations than others, which would account for widespread inter-speaker judgment variability
Extending additivity from symmetric to asymmetric channels
We prove a lemma which allows one to extend results about the additivity of
the minimal output entropy from highly symmetric channels to a much larger
class. A similar result holds for the maximal output -norm. Examples are
given showing its use in a variety of situations. In particular, we prove the
additivity and the multiplicativity for the shifted depolarising channel.Comment: 8 pages. This is the latest version of the first half of the original
paper. The other half will appear in another pape
Cow responses and evolution of the rumen bacterial and methanogen community following a complete rumen content transfer
Understanding the rumen microbial ecosystem requires the identification of factors that influence the community structure, such as nutrition, physiological condition of the host and host-microbiome interactions. The objective of the current study was to describe the rumen microbial communities before, during and after a complete rumen content transfer. The rumen contents of one donor cow were removed completely and used as inoculum for the emptied rumen of the donor itself and three acceptor cows under identical physiological and nutritional conditions. Temporal changes in microbiome composition and rumen function were analysed for each of four cows over a period of 6 weeks. Shortly after transfer, the cows showed different responses to perturbation of their rumen content. Feed intake depression in the first 2 weeks after transfer resulted in short-term changes in milk production, methane emission, fatty acid composition and rumen bacterial community composition. These effects were more pronounced in two cows, whose microbiome composition showed reduced diversity. The fermentation metrics and microbiome diversity of the other two cows were not affected. Their rumen bacterial community initially resembled the composition of the donor but evolved to a new community profile that resembled neither the donor nor their original composition. Descriptive data presented in the current paper show that the rumen bacterial community composition can quickly recover from a reduction in microbiome diversity after a severe perturbation. In contrast to the bacteria, methanogenic communities were more stable over time and unaffected by stress or host effects
The influence of stereotypes about old age on the perception of elderly employees’ labor activity
In this article the problem of increasing retirement age in terms of age discrimination and creating conditions encouraging elderly people to continue to work is discussed. This paper presents a study of stereotypes that affect students of management specialties in Russian institutions of higher education between the ages of 20 to 25 years old. The stereotype is investigated in the context of emotionally colored image of reality simplifying the process of perceiving it. The correlation between the students’ existing stereotypes about elderly people and their perception of older employees has been conducted. As a result, 5 stereotypes that exist in young people have been defined. An analysis of the words chosen by students to describe the elderly shows little diversity in young people’s perception of them. Lexical analysis shows that in the Russian language there are practically no concepts which allow creating a positive image of the elderly. The influence of the stereotypes on the perception of elderly people in terms of employment shows that older specialists are perceived as people with experience and knowledge but these experience and knowledge are irrelevant to the present
Estimating internal pelvic sizes using external body measurements in the double-muscled Belgian Bleu beef breed
In the double-muscled (DM) Belgian Blue beef (BBB) breed, caesarean section (CS) is being applied systematically as a management tool to prevent dystocia. As a matter of fact, CS is the only possible way of calving in the breed. High birth weight and a relatively small pelvic area are the main causes of dystocia and, in the DM-BBB breed, the reasons for the systematically applied CS. Selection for lower birth weight and larger pelvic sizes might reduce dystocia and routine CS. Few data on inner pelvic sizes of pedigree animals are available. Using external measurements to estimate the inner pelvic sizes might be an option to resolve this problem. In this study, animals of the DM-BBB breed were measured and weighed on farms and in abattoirs. External and internal pelvic sizes increased with live weight and age of the animals. Gender had a significant influence on inner pelvic traits. Increased muscular conformation was associated with decreased inner pelvic dimensions. Models with weight, gender, age, withers height and outer pelvic width (TcTc) can be used to estimate inner pelvic sizes (R-2 between 0.35 and 0.77). The estimated inner pelvic sizes can then be used to genetically evaluate pelvic traits in the DM-BBB breed. Improving weight, withers height and TcTc width in combination with lowering muscular conformation may help to decrease the high rate of caesarean section in the DM-BBB
Robust estimation of microbial diversity in theory and in practice
Quantifying diversity is of central importance for the study of structure,
function and evolution of microbial communities. The estimation of microbial
diversity has received renewed attention with the advent of large-scale
metagenomic studies. Here, we consider what the diversity observed in a sample
tells us about the diversity of the community being sampled. First, we argue
that one cannot reliably estimate the absolute and relative number of microbial
species present in a community without making unsupported assumptions about
species abundance distributions. The reason for this is that sample data do not
contain information about the number of rare species in the tail of species
abundance distributions. We illustrate the difficulty in comparing species
richness estimates by applying Chao's estimator of species richness to a set of
in silico communities: they are ranked incorrectly in the presence of large
numbers of rare species. Next, we extend our analysis to a general family of
diversity metrics ("Hill diversities"), and construct lower and upper estimates
of diversity values consistent with the sample data. The theory generalizes
Chao's estimator, which we retrieve as the lower estimate of species richness.
We show that Shannon and Simpson diversity can be robustly estimated for the in
silico communities. We analyze nine metagenomic data sets from a wide range of
environments, and show that our findings are relevant for empirically-sampled
communities. Hence, we recommend the use of Shannon and Simpson diversity
rather than species richness in efforts to quantify and compare microbial
diversity.Comment: To be published in The ISME Journal. Main text: 16 pages, 5 figures.
Supplement: 16 pages, 4 figure
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