Baroreflex sensitivity differs among same strain Wistar rats from the same laboratory

Previous studies showed that a proportion of normotensive Sprague-Dawley rats spontaneously exhibit lower baroreflex sensitivity. However, investigations have not yet been carried out on Wistar rats. We aimed to compare baroreflex sensitivity among rats from the same strain and the same laboratory. Male Wistar normotensive rats (300–400g) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure and heart rate. Baroreflex was calculated as the derivative of the variation of heart rate in function of the mean arterial pressure variation (ΔHR/ΔMAP) tested with a depressor dose of sodium nitroprusside (50 µg/kg) and with a pressor dose of phenylephrine (8µg/kg) in the right femoral venous approach through an inserted cannula. We divided the rats into four groups: i) high bradycardic baroreflex, baroreflex gain less than −2 tested with phenylephrine; ii) low bradycardic baroreflex, baroreflex gain between −1 and −2 tested with phenylephrine; iii) high tachycardic baroreflex, baroreflex gain less than −3 tested with sodium nitroprusside; and iv) low tachycardic baroreflex, baroreflex gain between −1 and −3 tested with sodium nitroprusside. Approximately 71% of the rats presented a decrease in bradycardic reflex while around half showed an increase in tachycardic reflex. No significant changes in basal mean arterial pressure and heart rate, tachycardic and bradycardic peak and heart rate range were observed. There was a significant change in baroreflex sensitivity among rats from the same strain and the same laboratory

Frozen-Ground Cartoons: An international collaboration between artists and permafrost scientists

Communicating science about a phenomenon found under ground and defined by its thermal properties in an easy, funny, and engaging way, can be a challenge. Two years ago, a group of young researchers from Canada and Europe united to tackle this problem by combining arts and science to produce a series of outreach comic strips about permafrost (frozen ground). Because this concerns us all. As the climate warms, permafrost thaws and becomes unstable for houses, roads and airports. The thawing also disrupts ecosystems, impacts water quality, and releases greenhouse gases into the atmosphere, making climate change even stronger. The Frozen Ground Cartoon project aims to present and explain permafrost research, placing emphasis on field work and the rapidly changing northern environment. The target audience is kids, youth, parents and teachers, with the general goal of making permafrost science more fun and accessible to the public. The project has so far produced 22 pages of comics through an iterative process of exchanging ideas between two artists and thirteen scientists. The project artists were selected through an application call that received 49 applications from artists in 16 countries. With input from scientists, artists Noémie Ross (Canada) and Heta Nääs (Finland) have created a set of beautiful, artistic, humoristic, and pedagogic comics. The comics are available for free download through the project web page (in English and Swedish), and printed copies have so far been handed out to school kids and general public in Europe and Canada. The next steps of this project are (1) to distribute the comics as wide as possible, (2) work towards translations into more languages, and (3) to evaluate the effectiveness of the science communication through the comics, in collaboration with schools and pedagogic experts

Prioritizing genes associated with prostate cancer development

<p>Abstract</p> <p>Background</p> <p>The genetic control of prostate cancer development is poorly understood. Large numbers of gene-expression datasets on different aspects of prostate tumorigenesis are available. We used these data to identify and prioritize candidate genes associated with the development of prostate cancer and bone metastases. Our working hypothesis was that combining meta-analyses on different but overlapping steps of prostate tumorigenesis will improve identification of genes associated with prostate cancer development.</p> <p>Methods</p> <p>A <it>Z </it>score-based meta-analysis of gene-expression data was used to identify candidate genes associated with prostate cancer development. To put together different datasets, we conducted a meta-analysis on 3 levels that follow the natural history of prostate cancer development. For experimental verification of candidates, we used in silico validation as well as in-house gene-expression data.</p> <p>Results</p> <p>Genes with experimental evidence of an association with prostate cancer development were overrepresented among our top candidates. The meta-analysis also identified a considerable number of novel candidate genes with no published evidence of a role in prostate cancer development. Functional annotation identified cytoskeleton, cell adhesion, extracellular matrix, and cell motility as the top functions associated with prostate cancer development. We identified 10 genes--<it>CDC2, CCNA2, IGF1, EGR1, SRF, CTGF, CCL2, CAV1, SMAD4</it>, and <it>AURKA</it>--that form hubs of the interaction network and therefore are likely to be primary drivers of prostate cancer development.</p> <p>Conclusions</p> <p>By using this large 3-level meta-analysis of the gene-expression data to identify candidate genes associated with prostate cancer development, we have generated a list of candidate genes that may be a useful resource for researchers studying the molecular mechanisms underlying prostate cancer development.</p

Functional Connectivity in Tactile Object Discrimination—A Principal Component Analysis of an Event Related fMRI-Study

BACKGROUND: Tactile object discrimination is an essential human skill that relies on functional connectivity between the neural substrates of motor, somatosensory and supramodal areas. From a theoretical point of view, such distributed networks elude categorical analysis because subtraction methods are univariate. Thus, the aim of this study was to identify the neural networks involved in somatosensory object discrimination using a voxel-based principal component analysis (PCA) of event-related functional magnetic resonance images. METHODOLOGY/PRINCIPAL FINDINGS: Seven healthy, right-handed subjects aged between 22 and 44 years were required to discriminate with their dominant hand the length differences between otherwise identical parallelepipeds in a two-alternative forced-choice paradigm. Of the 34 principal components retained for analysis according to the 'bootstrapped' Kaiser-Guttman criterion, t-tests applied to the subject-condition expression coefficients showed significant mean differences between the object presentation and inter-stimulus phases in PC 1, 3, 26 and 32. Specifically, PC 1 reflected object exploration or manipulation, PC 3 somatosensory and short-term memory processes. PC 26 evinced the perception that certain parallelepipeds could not be distinguished, while PC 32 emerged in those choices when they could be. Among the cerebral regions evident in the PCs are the left posterior parietal lobe and premotor cortex in PC 1, the left superior parietal lobule (SPL) and the right cuneus in PC 3, the medial frontal and orbitofrontal cortex bilaterally in PC 26, and the right intraparietal sulcus, anterior SPL and dorsolateral prefrontal cortex in PC 32. CONCLUSIONS/SIGNIFICANCE: The analysis provides evidence for the concerted action of large-scale cortico-subcortical networks mediating tactile object discrimination. Parallel to activity in nodes processing object-related impulses we found activity in key cerebral regions responsible for subjective assessment and validation

Validar a guerra: a construção do regime de Expertise estratégica

This article is intended to contribute to the interpretative analysis of war. For that purpose, it investigates how some apparatuses located in strategic thinking help to make modern war a social practice considered both technically feasible and, at the same time, legitimate for soldiers. In so doing, it makes use of two different but closely related theoretical fields, pragmatic sociology (finding inspiration in the work of scholars such as Luc Boltanski, Nicolas Dodier and Francis Chateauraynaud), and the sociology of scientific knowledge (based mostly on the work of Bruno Latour). On the one hand, the sociology of scientific knowledge has developed a productive questioning of the construction of scientific facts that is particularly relevant to the present research. On the other hand, pragmatic sociology generates a compatible framework able to describe collective actions. The combination of both approaches allows the description of the formation of a strategic expertise regime that supports the technical legitimacy of the use of military force. Together, the sociology of scientific knowledge and pragmatic sociology bring a particularly relevant perspective to research pertaining to war.info:eu-repo/semantics/publishe

A unified model for BAM function that takes into account type Vc secretion and species differences in BAM composition

Transmembrane proteins in the outer membrane of Gram-negative bacteria are almost exclusively β-barrels. They are inserted into the outer membrane by a conserved and essential protein complex called the BAM (for β-barrel assembly machinery). In this commentary, we summarize current research into the mechanism of this protein complex and how it relates to type V secretion. Type V secretion systems are autotransporters that all contain a β-barrel transmembrane domain inserted by BAM. In type Vc systems, this domain is a homotrimer. We argue that none of the current models are sufficient to explain BAM function particularly regarding type Vc secretion. We also find that current models based on the well-studied model system Escherichia coli mostly ignore the pronounced differences in BAM composition between different bacterial species. We propose a more holistic view on how all OMPs, including autotransporters, are incorporated into the lipid bilayer