Comparative analysis of morphological and morphometrical characters in six isolates of Pratylenchus vulnus Allen & Jensen, 1951 (Nemata : Tylenchida)

Six populations de #Pratylenchus vulnus$ Allen & Jensen, 1951 provenant d'Europe et d'Amérique ont été analysées du point de vue morphologique et morphométrique. Certaines différences ont été observées pour quelques caractères morphologiques (structure du sac post-vulvaire, forme de la spermathèque, largeur des champs latéraux). Par contre, des différences significatives concernant tous les caractères morphométriques (excepté le rapport "m") ont été constatées entre les populations. Une analyse de corrélation canonique montre que les relations entre populations pourraient être fonction de leur origine géographique et/ou de leur plante hôte. (Résumé d'auteur

Qeco: Una aplicación de arquitectura abierta para el desarrollo de aplicaciones de R con interfaz gráfica

Qeco surge para dar respuesta a los requerimientos de la comunidad de ecólogos para implementar métodos estadísticos y cuantitativos modernos basados en R en el marco de una aplicación con una interfaz gráfica. La principal característica que hace a Qeco diferente es que une lo mejor de las aplicaciones basadas en menús con el poder de R en una aplicación de arquitectura abierta diseñada para crecer de acuerdo a las necesidades y el conocimiento de los usuarios. Esta arquitectura permite crear aplicaciones personalizadas que pueden aprovechar el esfuerzo de múltiples desarrolladores, favoreciendo el nacimiento de proyectos colaborativos.Sociedad Argentina de Informática e Investigación Operativ

Molecular dynamics simulations reveal canonical conformations in different pMHC/TCR interactions

The major defense system against microbial pathogens in vertebrates is the adaptive immune response and represents an effective mechanism in cancer surveillance. T cells represent an essential component of this complex system. They can recognize myriads of antigens as short peptides (p) originated from the intracellular degradation of foreign proteins presented by major histocompatibility complex (MHC) proteins. The clonotypic T-cell antigen receptor (TCR) is specialized in recognizing pMHC and triggering T cells immune response. It is still unclear how TCR engagement to pMHC is translated into the intracellular signal that initiates T-cell immune response. Some work has suggested the possibility that pMHC binding induces in the TCR conformational changes transmitted to its companion CD3 subunits that govern signaling. The conformational changes would promote phosphorylation of the CD3 complex ζ chain that initiates signal propagation intracellularly. Here, we used all-atom molecular dynamics simulations (MDs) of 500 ns to analyze the conformational behavior of three TCRs (1G4, ILA1 and ILA1α1β1) interacting with the same MHC class I (HLA-A*02:01) bound to different peptides, and modelled in the presence of a lipid bilayer. Our data suggest a correlation between the conformations explored by the β-chain constant regions and the T-cell response experimentally determined. In particular, independently by the TCR type involved in the interaction, the TCR activation seems to be linked to a specific zone of the conformational space explored by the β-chain constant region. Moreover, TCR ligation restricts the conformational space the MHC class I groove

Closed-Loop Cardiovascular Interactions and the Baroreflex Cardiac Arm: Modulations Over the 24 h and the Effect of Hypertension

Closed-loop models of the interactions between blood pressure (BP) and heart rate variations allow for estimation of baroreflex sensitivity (feedback effects of BP changes on heart rate) while also considering the feedforward effects of heart rate on BP. Our study is aimed at comparing modulations of feedback and feedforward couplings over 24 h in normotensive and hypertensive subjects, by assessing closed-loop baroreflex models in ambulatory conditions. Continuous intra-arterial BP recordings were performed for 24 h in eight normotensive and eight hypertensive subjects. Systolic BP (SBP) and pulse interval (PI) beat-by-beat series were analyzed by an autoregressive moving average model over consecutive 6-min running windows, estimating closedloop feedback and feedforward gains in each window. The open-loop feedback gain was estimated for comparison. Normotensive and hypertensive patients were compared during wake (18:00–22:00) and sleep (23:00–5:00) periods by a mixed-effect linear model at p \u3c 0.05. In both groups feedback (feedforward) gain averaged values were higher (lower) in sleep than in wake. Moreover, the closed-loop feedback gain was higher in normotensive subjects both in wake and sleep, whereas the closedloop feedforward gain was higher in hypertensive subjects during sleep. By contrast, no significant differences were found between the normotensive and hypertensive groups for the open-loop feedback gain. Therefore, the closed-loop SBP-PI model can detect circadian alterations in the feedforward gain of PI on SBP and derangements of spontaneous baroreflex sensitivity in hypertension not detectable with the open-loop approach. These findings may help to obtain a more comprehensive assessment of the autonomic dysfunction underlying hypertension and for the in-depth evaluation of the benefits of rehabilitation procedures on autonomic cardiovascular modulation

Prevalence of common disease-associated variants in Asian Indians

<p>Abstract</p> <p>Background</p> <p>Asian Indians display a high prevalence of diseases linked to changes in diet and environment that have arisen as their lifestyle has become more westernized. Using 1200 genome-wide polymorphisms in 432 individuals from 15 Indian language groups, we have recently shown that: (i) Indians constitute a distinct population-genetic cluster, and (ii) despite the geographic and linguistic diversity of the groups they exhibit a relatively low level of genetic heterogeneity.</p> <p>Results</p> <p>We investigated the prevalence of common polymorphisms that have been associated with diseases, such as atherosclerosis (<it>ALOX5</it>), hypertension (<it>CYP3A5</it>, <it>AGT</it>, <it>GNB3</it>), diabetes (<it>CAPN10</it>, <it>TCF7L2</it>, <it>PTPN22</it>), prostate cancer (DG8S737, rs1447295), Hirschsprung disease (<it>RET</it>), and age-related macular degeneration (<it>CFH</it>, <it>LOC387715</it>). In addition, we examined polymorphisms associated with skin pigmentation (<it>SLC24A5</it>) and with the ability to taste phenylthiocarbamide (<it>TAS2R38</it>). All polymorphisms were studied in a cohort of 576 India-born Asian Indians sampled in the United States. This sample consisted of individuals whose mother tongue is one of 14 of the 22 "official" languages recognized in India as well as individuals whose mother tongue is Parsi, a cultural group that has resided in India for over 1000 years. Analysis of the data revealed that allele frequency differences between the different Indian language groups were small, and interestingly the variant alleles of <it>ALOX5 </it>g.8322G>A and g.50778G>A, and <it>PTPN22 </it>g.36677C>T were present only in a subset of the Indian language groups. Furthermore, a latitudinal cline was identified both for the allele frequencies of the SNPs associated with hypertension (<it>CYP3A5</it>, <it>AGT</it>, <it>GNB3</it>), as well as for those associated with the ability to taste phenylthiocarbamide (<it>TAS2R38</it>).</p> <p>Conclusion</p> <p>Although caution is warranted due to the fact that this US-sampled Indian cohort may not represent a random sample from India, our results will hopefully assist in the design of future studies that investigate the genetic causes of these diseases in India. Our results also support the inclusion of the Indian population in disease-related genetic studies, as it exhibits unique genotype as well as phenotype characteristics that may yield new insights into the underlying causes of common diseases that are not available in other populations.</p

Assessing soil P fractions changes with long-term phosphorus fertilization related to crop yield of soybean and maize

Long-term P Fertiliser application increases soil phosphorus (P) labile fractions, which can be associated with crop P uptake and grain yield and are useful to improve fertilizer recommendations. Research aims were to evaluate in long-term experiments with different P Fertiliser application in a Mollisol and a Vertisol: (a) the changes of soil P fractions and (b) the relationship between soil P fractions with long-term P Fertiliser application, with accumulated apparent P budget, grain P, total P uptake, soybean (Glycine max L.Merr.) and maize (Zea mays L.) grain yield. Soil P fractions were measured after 1 and 9 year since the beginning of the long-term experiments. Experiments included an initial Fertiliser application rate of 200 kg P ha−1 and annual P Fertiliser application rate of 36 kg P ha−1. Bray1-P, total, organic, and inorganic P in fine (53 μm) (CF) soil fractions, and in NaHCO3 extract were measured. Initial P Fertiliser application increased inorganic and total P fractions. However, Bray1-P, total P in NaHCO3 extract and in the CF were the fractions that most increased with continuous long-term P Fertiliser application in both sites. In the Mollisol, maize grain yield was unrelated to long-term P Fertiliser application. In the Vertisol, total P in NaHCO3 extract, and total and organic P in the CF were more closely related to soybean grain yield than Bray1-P. We proposed soil P indices of labile inorganic and organic P that showed close relationships with soybean grain yield and may be useful to improve the diagnosis of P soil fertility.Fil: Appelhans, Stefania Carolina. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Departamento de Producción Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barbagelata, Pedro Aníbal. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Departamento de Producción Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Melchiori, Ricardo José Miguel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Gutiérrez Boem, Flavio Hernán. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Ingeniería Agrícola y Uso de la Tierra. Cátedra de Fertilidad y Fertilizantes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Variabilidad de los caracteres morfométricos y morfológicos de una población de Criconemetia curvata ( Raski, 1952 ) Luc & Raski, 1981 (Nematoda: Tylenchida)

Se llevó a cabo un estudio de la variabilidad de los calacteres morfométricos y morfológicos de una pobación (hembras y larvas) del nematodo fitófago Criconemella C'urvata (Raski, 1952) Luc &amp; Raski, 1981 proveniente de Córdoba, Argentina. Dicha variablidad fue conocida en base a: análisis estadístico de cada uno de los caracteres morfométricos y análisis de la frecuencia relativa de cada carácter morfológico dentro de la población. En el caso particular de las larvas, se demuestra que la utilización de la longitud de la porción cónica del est Tete permite discriminar con precisión los diferentes estadios. Se efectuó un estudio crítico de la importancia de cada grupo de caracteres en la definición de la especi

Coexistence and Within-Host Evolution of Diversified Lineages of Hypermutable Pseudomonas aeruginosa in Long-term Cystic Fibrosis Infections

The advent of high-throughput sequencing techniques has made it possible to follow the genomic evolution of pathogenic bacteria by comparing longitudinally collected bacteria sampled from human hosts. Such studies in the context of chronic airway infections by Pseudomonas aeruginosa in cystic fibrosis (CF) patients have indicated high bacterial population diversity. Such diversity may be driven by hypermutability resulting from DNA mismatch repair system (MRS) deficiency, a common trait evolved by P. aeruginosa strains in CF infections. No studies to date have utilized whole-genome sequencing to investigate within-host population diversity or long-term evolution of mutators in CF airways. We sequenced the genomes of 13 and 14 isolates of P. aeruginosa mutator populations from an Argentinian and a Danish CF patient, respectively. Our collection of isolates spanned 6 and 20 years of patient infection history, respectively. We sequenced 11 isolates from a single sample from each patient to allow in-depth analysis of population diversity. Each patient was infected by clonal populations of bacteria that were dominated by mutators. The in vivo mutation rate of the populations was ∼100 SNPs/year-∼40-fold higher than rates in normo-mutable populations. Comparison of the genomes of 11 isolates from the same sample showed extensive within-patient genomic diversification; the populations were composed of different sub-lineages that had coexisted for many years since the initial colonization of the patient. Analysis of the mutations identified genes that underwent convergent evolution across lineages and sub-lineages, suggesting that the genes were targeted by mutation to optimize pathogenic fitness. Parallel evolution was observed in reduction of overall catabolic capacity of the populations. These findings are useful for understanding the evolution of pathogen populations and identifying new targets for control of chronic infections

A Longitudinal Cline Characterizes the Genetic Structure of Human Populations in the Tibetan Plateau

Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their de- mography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with world- wide genetic variation data. We found a clear signal of genetic stratification across the east- west axis within Tibetan samples. Samples from more eastern locations tend to have higher genetic affinity with lowland East Asians, which can be explained by more gene flow from lowland East Asia onto the plateau. Our findings corroborate a previous report of admixture signals in Tibetans, which were based on a subset of the samples analyzed here, but add evidence for isolation by distance in a broader geospatial context