Comparative genomics suggests primary homothallism of Pneumocystis species.

UNLABELLED: Pneumocystis species are fungal parasites of mammal lungs showing host specificity. Pneumocystis jirovecii colonizes humans and causes severe pneumonia in immunosuppressed individuals. In the absence of in vitro cultures, the life cycle of these fungi remains poorly known. Sexual reproduction probably occurs, but the system of this process and the mating type (MAT) genes involved are not characterized. In the present study, we used comparative genomics to investigate the issue in P. jirovecii and Pneumocystis carinii, the species infecting rats, as well as in their relative Taphrina deformans. We searched sex-related genes using 103 sequences from the relative Schizosaccharomyces pombe as queries. Genes homologous to several sex-related role categories were identified in all species investigated, further supporting sexuality in these organisms. Extensive in silico searches identified only three putative MAT genes in each species investigated (matMc, matMi, and matPi). In P. jirovecii, these genes clustered on the same contig, proving their contiguity in the genome. This organization seems compatible neither with heterothallism, because two different MAT loci on separate DNA molecules would have been detected, nor with secondary homothallism, because the latter involves generally more MAT genes. Consistently, we did not detect cis-acting sequences for mating type switching in secondary homothallism, and PCR revealed identical MAT genes in P. jirovecii isolates from six patients. A strong synteny of the genomic region surrounding the putative MAT genes exists between the two Pneumocystis species. Our results suggest the hypothesis that primary homothallism is the system of reproduction of Pneumocystis species and T. deformans. IMPORTANCE: Sexual reproduction among fungi can involve a single partner (homothallism) or two compatible partners (heterothallism). We investigated the issue in three pathogenic fungal relatives: Pneumocystis jirovecii, which causes severe pneumonia in immunocompromised humans; Pneumocystis carinii, which infects rats; and the plant pathogen Taphrina deformans. The nature, the number, and the organization within the genome of the genes involved in sexual reproduction were determined. The three species appeared to harbor a single genomic region gathering only three genes involved in sexual differentiation, an organization which is compatible with sexual reproduction involving a single partner. These findings illuminate the strategy adopted by fungal pathogens to infect their hosts

Validação numérica de lajes celulares em madeira com perfurações ao fogo

As lajes em madeira são estruturas leves, de fácil montagem, com excelentes características arquitetónicas, térmicas e acústicas. No entanto, a sua elevada vulnerabilidade ao fogo, obriga a que se determine e avalie o seu comportamento com rigor. Com base em ensaios experimentais, realizados para a determinação da resistência ao fogo, será possível validar um modelo de laje numérico desenvolvido com a utilização de um programa de elementos finitos, ANSYS. O modelo numérico é transiente térmico, não linear e utiliza elementos hexaédricos. Considerou-se a não linearidade das propriedades a temperaturas elevadas. As condições de fronteira, admitidas no problema, são de convecção e radiação, sendo consideradas curvas típicas para a evolução da temperatura. Estas curvas foram registadas durante os ensaios experimentais e permitiram simular o efeito da ação do fogo na superfície exposta, interior das cavidades celulares e nas aberturas ou perfurações da laje. O comportamento físico da laje é também condicionado pela formação da carbonização, sendo este fenómeno considerado no modelo numérico

Eficacia del rimadyl® en el control del dolor y la recuperación postquirúrgica después de una cirugía por dislocación abomasal

Se han estudiado los efectos de la aplicación de Rimadyl® (carprofeno 50 mg/ml) sobre la concentración de cortisol, temperatura rectal, frecuencia respiratoria, frecuencia cardiaca y motilidad ruminal, con el objetivo evaluar su eficacia en el control del dolor y la recuperación postquirúrgica, al aplicarlo antes de la cirugía por dislocación abomasal. Se seleccionaron 24 vacas de características similares que iban a someterse a cirugía por dislocación abomasal y se asignaron al azar a uno de los dos tratamientos experimentales: Rimadyl® o suero salino fisiológico. La aplicación de Rimadyl® disminuye (P=0,006) la concentración plasmática de cortisol (11,3 ng/mL vs 22,13 ng/mL). Con el tiempo se reducen (P=0,024) los niveles de cortisol plasmático. Esta reducción es más acusada (P=0,0003) con Rimadyl® a las 6 horas de su aplicación. La producción de leche postcirugía fue mayor en los animales que recibieron Rimadyl® en comparación con los que se les aplicó suero salino fisiológic

Direct approach to the problem of strong local minima in Calculus of Variations

The paper introduces a general strategy for identifying strong local minimizers of variational functionals. It is based on the idea that any variation of the integral functional can be evaluated directly in terms of the appropriate parameterized measures. We demonstrate our approach on a problem of W^{1,infinity} weak-* local minima--a slight weakening of the classical notion of strong local minima. We obtain the first quasiconvexity-based set of sufficient conditions for W^{1,infinity} weak-* local minima.Comment: 26 pages, no figure

Quasiconvexity at the boundary and the nucleation of austenite

Motivated by experimental observations of H. Seiner et al., we study the nucleation of austenite in a single crystal of a CuAlNi shape-memory alloy stabilized as a single variant of martensite. In the experiments the nucleation process was induced by localized heating and it was observed that, regardless of where the localized heating was applied, the nucleation points were always located at one of the corners of the sample - a rectangular parallelepiped in the austenite. Using a simplified nonlinear elasticity model, we propose an explanation for the location of the nucleation points by showing that the martensite is a local minimizer of the energy with respect to localized variations in the interior, on faces and edges of the sample, but not at some corners, where a localized microstructure, involving austenite and a simple laminate of martensite, can lower the energy. The result for the interior, faces and edges is established by showing that the free-energy function satisfies a set of quasiconvexity conditions at the stabilized variant in the interior, faces and edges, respectively, provided the specimen is suitably cut

Three-step Bayesian factor analysis applied to QTL detection in crosses between outbred pig populations

AbstractMarker assisted selection (MAS) can be used to improve the efficiency of genetic selection of traits for which phenotypic measurements are expensive or cannot be obtained on selection candidates, such as carcass traits. Marker information required for MAS may be acquired through the identification of QTLs. Generally, univariate models are used for QTL detection, although multiple-trait models (MTM) may enhance QTL detection and breeding value estimation. In MTM, however, the number of parameters can be large and, if traits are highly correlated, such as carcass traits, estimates of (co)variance matrices may be close to singular. Because of this, dimension reduction techniques such as Factor Analysis (FA) may be useful. The aim of our project is to evaluate the use of FA for structuring (co)variance matrices in the context of Bayesian models for QTL detection in crosses between outbred populations. In our method, QTL effects are postulated at the level of common factors (CF) rather than the original traits, using a three-step approach. In a first step, a MTM is fitted to arrive at estimates of systematic effects and prediction of breeding values (procedure A) and only systematic effect (procedure B). These estimates/predictions are then used to generate an adjusted phenotype that is further analyzed with a Bayesian FA model. This step yields estimates of factor scores for each animal and CF. In the last step, the scores relative to each CF are analyzed independently using probabilities for the line of origin combination. To illustrate the methodology, data on 416 F2 pigs (Brazilian Piau X commercial) with ten traits (5 fat-related, 2 loin measurements, and 3 carcass classification systems) were analyzed. For each of the three resulting CFs, an independent QTL scan was performed on chromosome 7 considering three models: I) null (i.e., absence of QTL); II) additive effect QTL, and III) additive and dominance effect QTL. The posterior probability (PP) of each model was calculated from Bayes factor for each considered procedures (A and B). A Three-step Bayesian factor analysis allowed us to calculate the probability of QTLs that simultaneously affect a group of carcass traits for each position of SSC 7. The removal of systematic effects in the first step of the evaluation (procedure B) allowed that the factor analysis, which was performed in the second step, identify three distinct factors that explained 85% of the total traits variation. For the common factor that represented fat-related traits (bacon depth, midline lower backfat thickness, higher backfat thickness on the shoulder; midline backfat thickness after the last rib; midline backfat thickness on the last lumbar vertebrae) the third step of the analysis showed that the highest probability of an additive QTL effect at the 65cM position was 86%

intraspecific geometric morphometric analysis of wings of the blowfly Chrysomya albiceps (Diptera: Calliphoridae)

Funding Information: Luis Marques is acknowledged for his help with the images and Ana Catarina Fialho for her assistance in the field collection. The authors are grateful to the technical imaging support of Faculty of Sciences of the University of Lisbon's Microscopy Facility which is a node of the Portuguese Platform of BioImaging, reference PPBI-POCI-01-0145-FEDER-022122 , and to FCT/MCTES for financial support to CESAM ( UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020 ), to CIISA by Project UIDB/00276/2020 , to GHTM ( UID/04413/2020 ) and CE3C ( UIBD/00329/2020 ). Publisher Copyright: © 2022 Elsevier B.V.Blowflies have forensic, sanitary and veterinary importance, as well as being pollinators, parasitoids and ecological bioindicators. There is still little work with real data and from experiments assessing the relationship between blowflies’ morphologic features and environmental and demographic factors. The present work tests whether the variation, in the shape and size, of Chrysomya albiceps (Wiedemann, 1819) wings is influenced by the following factors: 1) time; 2) temperature; 3) sex and; 4) different types of carcasses (pig, dog/cat and whale). Male and female wings from four different sites collected in six different years were used to obtain wing size and shape of C. albiceps. Analyses between wing shape and the variables tested had low explanatory power, even though they had statistical support. However, it was possible to identify differences in wing shape between males and females, with good returns in sex identification. The comparison between wing size and the variables tested showed that wing size has a negative relationship with temperature, significant differences between sexes, slight variation over time and no influence by carcass types. Furthermore, wing size influenced wing shape. Understanding population-specific characteristics of C. albiceps provide important insights about how the species reacts under specific conditions.publishersversionpublishe

Revealing higher than expected meiofaunal diversity in Antarctic sediments:a metabarcoding approach

An increasing number of studies are showing that Antarctic mega- and macrofauna are highly diverse, however, little is known about meiofaunal biodiversity in sediment communities, which are a vital part of a healthy and functional ecosystem. This is the first study to analyse community DNA (targeting meiofauna) using metabarcoding to investigate biodiversity levels in sediment communities of the Antarctic Peninsula. The results show that almost all of the meiofaunal biodiversity in the benthic habitat has yet to be characterised, levels of biodiversity were higher than expected and similar to temperate regions, albeit with the existence of potentially new and locally adapted species never described before at the molecular level. The Rothera meiofaunal sample sites showed four dominant eukaryotic groups, the nematodes, arthropods, platyhelminthes, and the annelids; some of which could comprise species complexes. Comparisons with deep-sea data from the same region suggest little exchange of Operational Taxonomic Units (OTUs) between depths with the nematodes prevalent at all depths, but sharing the shallow water benthos with the copepods. This study provides a preliminary analysis of benthic Antarctic Peninsula meiofauna using high throughput sequencing which substantiates how little is known on the biodiversity of one of the most diverse, yet underexplored communities of the Antarctic: the benthos