694 research outputs found

    Genotype by environment interaction for 450-day weight of Nelore cattle analyzed by reaction norm models

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    Genotype by environment interactions (GEI) have attracted increasing attention in tropical breeding programs because of the variety of production systems involved. In this work, we assessed GEI in 450-day adjusted weight (W450) Nelore cattle from 366 Brazilian herds by comparing traditional univariate single-environment model analysis (UM) and random regression first order reaction norm models for six environmental variables: standard deviations of herd-year (RRMw) and herd-year-season-management (RRMw-m) groups for mean W450, standard deviations of herd-year (RRMg) and herd-year-season-management (RRMg-m) groups adjusted for 365-450 days weight gain (G450) averages, and two iterative algorithms using herd-year-season-management group solution estimates from a first RRMw-m and RRMg-m analysis (RRMITw-m and RRMITg-m, respectively). The RRM results showed similar tendencies in the variance components and heritability estimates along environmental gradient. Some of the variation among RRM estimates may have been related to the precision of the predictor and to correlations between environmental variables and the likely components of the weight trait. GEI, which was assessed by estimating the genetic correlation surfaces, had values < 0.5 between extreme environments in all models. Regression analyses showed that the correlation between the expected progeny differences for UM and the corresponding differences estimated by RRM was higher in intermediate and favorable environments than in unfavorable environments (p < 0.0001)

    Microbiota of Vibrio sp. in the hepatopancreas of cultured white pacific shrimp (Litopenaeus vannamei)

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    ABSTRACT Objective. The present study aimed to investigate the presence of vibrios in the hepatopancreas of cultured shrimp. Materials and methods. Vibrios from the hepatopancreas of fifteen samples of five specimens each, of apparently healthy Pacific white shrimp (Litopenaeus vannamei) were isolated, identified and quantified. Results. The vibrio density ranged from 430 to 2,400 MPN g-1 (rs MPN cm-1=-0.114; rs MPN g-1 = 0.211). Thirty isolations were obtained, most of which belonged to the species V. cholerae (n=11) and V. parahaemolyticus (n=7). Conclusions. The outcomes of the present study suggest that, even in the absence of symptoms of vibriosis, the microbiota of the hepatopancreas of cultured shrimp may include sucrose positive and negative vibrios

    Local Chatter or International Buzz? Language Differences on Posts about Zika Research on Twitter and Facebook

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    Background When the Zika virus outbreak became a global health emergency in early 2016, the scientific community responded with an increased output of Zika-related research. This upsurge in research naturally made its way into academic journals along with editorials, news, and reports. However, it is not yet known how or whether these scholarly communications were distributed to the populations most affected by Zika. Methodology/Principal findings To understand how scientific outputs about Zika reached global and local audiences, we collected Tweets and Facebook posts that linked to Zika-related research in the first six months of 2016. Using a language detection algorithm, we found that up to 90% of Twitter and 76% of Facebook posts are in English. However, when none of the authors of the scholarly article are from English-speaking countries, posts on both social media are less likely to be in English. The effect is most pronounced on Facebook, where the likelihood of posting in English is between 11 and 16% lower when none of the authors are from English-speaking countries, as compared to when some or all are. Similarly, posts about papers written with a Brazilian author are 13% more likely to be in Portuguese on Facebook than when made on Twitter. Conclusions/Significance Our main conclusion is that scholarly communication on Twitter and Facebook of Zikarelated research is dominated by English, despite Brazil being the epicenter of the Zika epidemic. This result suggests that scholarly findings about the Zika virus are unlikely to be distributed directly to relevant populations through these popular online mediums. Nevertheless, there are differences between platforms. Compared to Twitter, scholarly communication on Facebook is more likely to be in the language of an author’s country. The Zika outbreak provides a useful case-study for understanding how scientific outputs are communicated to relevant populations. Our results suggest that Facebook is a more effective channel than Twitter, if communication is desired to be in the native language of the affected country. Further research should explore how local media—such as governmental websites, newspapers and magazines, as well as television and radio—disseminate scholarly publication
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