201 research outputs found
Composition of a chemical signalling trait varies with phylogeny and precipitation across an Australian lizard radiation
The environment presents challenges to the transmission and detection of animal signalling systems, resulting in selective pressures that can drive signal divergence amongst populations in disparate environments. For chemical signals, climate is a potentially important selective force because factors such as temperature and moisture influence the persistence and detection of chemicals. We investigated an Australian lizard radiation (Heteronotia) to explore relationships between a sexually dimorphic chemical signalling trait (epidermal pore secretions) and two key climate variables: temperature and precipitation. We reconstructed the phylogeny of Heteronotia with exon capture phylogenomics, estimated phylogenetic signal in amongst-lineage chemical variation and assessed how chemical composition relates to temperature and precipitation using multivariate phylogenetic regressions. High estimates of phylogenetic signal indicate that the composition of epidermal pore secretions varies amongst lineages in a manner consistent with Brownian motion, although there are deviations to this, with stark divergences coinciding with two phylogenetic splits. Accounting for phylogenetic non-independence, we found that amongst-lineage chemical variation is associated with geographic variation in precipitation but not temperature. This contrasts somewhat with previous lizard studies, which have generally found an association between temperature and chemical composition. Our results suggest that geographic variation in precipitation can affect the evolution of chemical signalling traits, possibly influencing patterns of divergence amongst lineages and species
Initiation of speciation across multiple dimensions in a rock-restricted, tropical lizard
Population isolation and concomitant genetic divergence, resulting in strong phylogeographical structure, is a core aspect of speciation initiation. If and how speciation then proceeds and ultimately completes depends on multiple factors that mediate reproductive isolation, including divergence in genomes, ecology and mating traits. Here we explored these multiple dimensions in two young (Plio-Pleistocene) species complexes of gekkonid lizards (Heteronotia) from the Kimberley–Victoria River regions of tropical Australia. Using mitochondrial DNA screening and exon capture phylogenomics, we show that the rock-restricted Heteronotia planiceps exhibits exceptional fine-scale phylogeographical structure compared to the codistributed habitat generalist Heteronotia binoei. This indicates pervasive population isolation and persistence in the rock-specialist, and thus a high rate of speciation initiation across this geographically complex region, with levels of genomic divergence spanning the “grey zone” of speciation. Proximal lineages of H. planiceps were often separated by different rock substrates, suggesting a potential role for ecological isolation; however, phylogenetic incongruence and historical introgression were inferred between one such pair. Ecomorphological divergence among lineages within both H. planiceps and H. binoei was limited, except that limestone-restricted lineages of H. planiceps tended to be larger than rock-generalists. By contrast, among-lineage divergence in the chemical composition of epidermal pore secretions (putative mating trait) exceeded ecomorphology in both complexes, but with less trait overlap among lineages in H. planiceps. This system—particularly the rock-specialist H. planiceps—highlights the role of multidimensional divergence during incipient speciation, with divergence in genomes, ecomorphology and chemical signals all at play at very fine spatial scales
Exploring the diversity of Gardnerella vaginalis in the genitourinary tract microbiota of monogamous couples through subtle nucleotide variation
© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 6 (2011): e26732, doi:10.1371/journal.pone.0026732.Bacterial vaginosis (BV) is an enigmatic disease of unknown origin that affects a large percentage of women. The vaginal microbiota of women with BV is associated with serious sequelae, including abnormal pregnancies. The etiology of BV is not fully understood, however, it has been suggested that it is transmissible, and that G. vaginalis may be an etiological agent. Studies using enzymatic assays to define G. vaginalis biotypes, as well as more recent genomic comparisons of G. vaginalis isolates from symptomatic and asymptomatic women, suggest that particular G. vaginalis strains may play a key role in the pathogenesis of BV. To explore G. vaginalis diversity, distribution and sexual transmission, we developed a Shannon entropy-based method to analyze low-level sequence variation in 65,710 G. vaginalis 16S rRNA gene segments that were PCR-amplified from vaginal samples of 53 monogamous women and from urethral and penile skin samples of their male partners. We observed a high degree of low-level diversity among G. vaginalis sequences with a total of 46 unique sequence variants (oligotypes), and also found strong correlations of these oligotypes between sexual partners. Even though Gram stain-defined normal and some Gram stain-defined intermediate oligotype profiles clustered together in UniFrac analysis, no single G. vaginalis oligotype was found to be specific to BV or normal vaginal samples. This study describes a novel method for investigating G. vaginalis diversity at a low level of taxonomic discrimination. The findings support cultivation-based studies that indicate sexual partners harbor the same strains of G. vaginalis. This study also highlights the fact that a few, reproducible nucleotide variations within the 16S rRNA gene can reveal clinical or epidemiological associations that would be missed by genus-level or species-level categorization of 16S rRNA data.This work is supported by funding from the Research Institute for Children in New Orleans and NIH grant 5RO1AI79071-2
Commercially available endoscopy facemasks to prevent aerosolizing spread of droplets during COVID-19 outbreak
We read with great interest the ESGE and ESGENA Position Statement [1] on gastrointestinal endoscopy and the COVID-19 pandemic. We share the concerns listed in the suggested research agenda, particularly about enhancing procedural protection in the endoscopy unit to reduce risk of COVID-19 dissemination. We would like to bring attention to commercially available endoscopy masks that can be used to avoid aerosolizing spread of droplets during upper endoscopic procedures. These products seem to improve intra-procedure risk management and can serve as an alternative to a modified ventilation mask reported for this purpose by Marchese et al [2]
Renal prostacyclin influences renal function in non-azotemic cirrhotic patients treated with furosemide
The influence of prostaglandins on renal function changes induced by furosemide was analyzed in 21 non-azotemic cirrhotic patients with ascites. Patients were studied in two periods of 120 min immediately before and after furosemide infusion (20 mg, ev). Furosemide caused an increase in creatinine clearance in 15 patients (group A: 99 +/- 7 vs. 129 +/- 5 ml/min; mean +/- S.E.) and a reduction in the remaining six (group B: 102 +/- 13 vs. 71 +/- 9 ml/min). Parallel changes were observed in the urinary excretion of 6-Keto-prostaglandin-F1 alpha (metabolite of renal prostacyclin) which augmented after furosemide in 14 of the 15 patients from group A (478 +/- 107 vs. 1034 +/- 159 pg/min, p less than 0.001) and decreased in all patients from group B (1032 +/- 240 vs. 548 +/- 136 pg/min, p less than 0.05). In contrast, the urinary excretion of prostaglandin E2 was stimulated by furosemide in all patients (group A, 92 +/- 19 vs. 448 +/- 60 pg/min, p less than 0.001; and group B, 209 +/- 63 vs. 361 +/- 25 pg/min, p less than 0.05). In all of the patients furosemide-induced changes (post- minus pre-furosemide values) in creatinine clearance were closely correlated in a direct and linear fashion with those in 6-Keto-prostaglandin-F1 alpha (r = 0.74; p less than 0.001). These changes were associated with a higher furosemide-induced natriuresis in group A than in group B (641 +/- 68 vs. 302 +/-- 46 mumol/min, p less than 0.001
Bacterial communities in penile skin, male urethra, and vaginas of heterosexual couples with and without bacterial vaginosis
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Microbiome 4 (2016): 16, doi:10.1186/s40168-016-0161-6.The epidemiology of bacterial vaginosis (BV) suggests it is sexually transmissible, yet no transmissible agent has been identified. It is probable that BV-associated bacterial communities are transferred from male to female partners during intercourse; however, the microbiota of sexual partners has not been well-studied. Pyrosequencing analysis of PCR-amplified 16S rDNA was used to examine BV-associated bacteria in monogamous couples with and without BV using vaginal, male urethral, and penile skin specimens. The penile skin and urethral microbiota of male partners of women with BV was significantly more similar to the vaginal microbiota of their female partner compared to the vaginal microbiota of non-partner women with BV. This was not the case for male partners of women with normal vaginal microbiota. Specific BV-associated species were concordant in women with BV and their male partners. In monogamous heterosexual couples in which the woman has BV, the significantly higher similarity between the vaginal microbiota and the penile skin and urethral microbiota of the male partner, supports the hypothesis that sexual exchange of BV-associated bacterial taxa is common.This work was supported by National Institute of Health Grant R01 AI079071-01A1
Upper Gastrointestinal Hemorrhage Associated with Fistula Formation in the Duodenum due to a Catheter Placed in the Hepatic Artery
Articulando trabajos de cátedra con necesidades sociales
La cátedra "Proyecto de Software" es una materia donde los alumnos desarrollan aplicaciones web usando PHP. La cursan aproximadamente 180 alumnos por año y sus contenidos terminan aplicados a un sistema sencillo basado en tecnologías open source.
La metodología utilizada en la cursada es plantear las distintas herramientas con las que se desea trabajar y aplicarlas a un sistema sencillo.
Desde el año 2001, los trabajos de los alumnos se basan en solicitudes concretas realizadas por organismos de la comunidad. Si bien se trata de buscar aplicaciones que puedan implementarse a lo largo de una cursada cuatrimestral, como es el caso de esta cátedra, los trabajos planteados/implementados han sido muy bien recibidos tanto por el lado de los alumnos como de las distintas organizaciones con las que se trabajó /trabaja.
El objetivo de este artículo es describir las distintas experiencias y los resultados obtenidos. Se detallará los mecanismos de implementación, basados siempre en el uso de herramientas de código abierto, los resultados de uso de los sistemas resultantes y el impacto que tiene en los alumnos el hecho de trabajar con necesidades de la comunidad.Red de Universidades con Carreras en Informática (RedUNCI
Paraganglioma gangliocítico duodenal
Se presenta el caso de un varón de 85 años que ingresó por dolor abdominal e ictericia, por lo cual se le realizaron diversas exploraciones, apreciandose en 2ª porción duodenal una masa cuyo estudio histológico demostró que se trataba de un paraganglioma gangliocítico duodenal. Se describen las características clínicas de este infrecuente tumor y revisamos su diagnóstico y tratamiento. We present the case of an 85 year old male who was admitted to hospital with abdominal pain and jaundice. Different explorations were performed for this reason, with a mass observed in his 2nd duodenal portion. Histiological study showed that it was a duodenal gangliocytic paraganlioma. The clinical characteristics of this infrequent tumour are described and we review the diagnosis and treatment
- …