Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Fission-product transport analysis for the loss of decay-heat-removal accident sequence at Browns Ferry

Non

Direct repeat-mediated deletion of a type IV pilin gene results in major virulence attenuation of Francisella tularensis.

Francisella tularensis, the causative agent of tularaemia, is a highly infectious and virulent intracellular pathogen. There are two main human pathogenic subspecies, Francisella tularensis ssp. tularensis (type A), and Francisella tularensis ssp. holarctica (type B). So far, knowledge regarding key virulence determinants is limited but it is clear that intracellular survival and multiplication is one major virulence strategy of Francisella. In addition, genome sequencing has revealed the presence of genes encoding type IV pili (Tfp). One genomic region encoding three proteins with signatures typical for type IV pilins contained two 120 bp direct repeats. Here we establish that repeat-mediated loss of one of the putative pilin genes in a type B strain results in severe virulence attenuation in mice infected by subcutaneous route. Complementation of the mutant by introduction of the pilin gene in cis resulted in complete restoration of virulence. The level of attenuation was similar to that of the live vaccine strain and this strain was also found to lack the pilin gene as result of a similar deletion event mediated by the direct repeats. Presence of the pilin had no major effect on the ability to interact, survive and multiply inside macrophage-like cell lines. Importantly, the pilin-negative strain was impaired in its ability to spread from the initial site of infection to the spleen. Our findings indicate that this putative pilin is critical for Francisella infections that occur via peripheral routes

Severidade da ferrugem-da-folha e seus efeitos sobre caracteres da panícula de aveia Crown rust severity and its effects on oat panicle characters

A ferrugem-da-folha (Puccinia coronata f.sp. avenae) foi quantificada em quatro populações F3 de aveia (Avena sativa L.) com o objetivo de estudar a severidade dessa moléstia e seus efeitos sobre seis caracteres da panícula. As populações utilizadas foram UFRGS 881920 x UFRGS 7, UFRGS 881920 x UFRGS 14, UFRGS 15 x UFRGS 7 e UFRGS 15 x UFRGS 14, sendo os genótipos UFRGS 881920 e UFRGS 15 resistentes à moléstia e os demais suscetíveis. A ferrugem-da-folha foi quantificada na época do florescimento, e próximo à maturação foram colhidas, em cada população, 10 plantas ao acaso por nota de ferrugem nas quais foram feitas as seguintes determinações: número de panículas, peso médio de panículas, número de grãos por planta e por panícula, peso de grãos e peso de mil grãos. A variabilidade em relação à severidade da ferrugem-da-folha foi analisada mediante a distribuição de freqüências das notas em cada população. A avaliação dos efeitos da moléstia sobre os caracteres da panícula foi feita pela análise de variância, análise de regressão polinomial e correlações fenotípicas. Os resultados obtidos demonstram haver ampla variação com respeito à severidade da moléstia nas populações estudadas, e os caracteres mais afetados foram o peso médio de panículas e o peso de mil grãos.<br>Crown rust (Puccinia coronata f.sp. avenae) was quantified in four F3 oat (Avena sativa L.) populations with the objective of studying disease severity and its effects on six panicle characters. Populations used were UFRGS 881920 x UFRGS 7, UFRGS 881920 x UFRGS 14, UFRGS 15 x UFRGS 7 and UFRGS 15 x UFRGS 14, with genotypes UFRGS 881920 and UFRGS 15 being resistant and the others susceptible. Crown rust infection was quantified at flowering stage and near grain maturity 10 plants at random were harvested per crown rust score in each population, and the following determinations were made: number of panicles, mean panicle weight, number of grains per plant and per panicle, grain weight and 1,000 grains weight. Variability for crown rust severity was analised through frequency distribution of crown rust scores in each population. Evaluation of crown rust effects on panicle characters was done through analysis of variance, polinomial regression analysis and phenotypic correlations. Results obtained demonstrate great variation for crown rust severity in the populations studied, and the most affected characters by disease occurence were mean panicle weight and 1,000 grains weight