Pherotypes are driving genetic differentiation within Streptococcus pneumoniae

<p>Abstract</p> <p>Background</p> <p>The boundaries of bacterial species and the mechanisms underlying bacterial speciation are matters of intense debate. Theoretical studies have shown that recombination acts as a strong cohesive force preventing divergence in bacterial populations. <it>Streptococcus pneumoniae </it>populations have the telltale signs of high recombination with competence implicated as the major driving force behind gene exchange. Competence in <it>S. pneumoniae </it>is triggered by a quorum-sensing mechanism controlled by the competence-stimulating peptide pheromone.</p> <p>Results</p> <p>We studied the distribution of the two major pherotypes in the pneumococcal population and their association with serotype, antimicrobial resistance and genetic lineage. Using multilocus sequence data we evaluated pherotype influence on the dynamics of horizontal gene transfer. We show that pherotype is a clonal property of pneumococci. Standard population genetic analysis and multilocus infinite allele model simulations support the hypothesis that two genetically differentiated populations are defined by the major pherotypes.</p> <p>Conclusion</p> <p>Severe limitations to gene flow can therefore occur in bacterial species in the absence of geographical barriers and within highly recombinogenic populations. This departure from panmixia can have important consequences for our understanding of the response of pneumococci to human imposed selective pressures such as vaccination and antibiotic use.</p

Membership role and subjective group dynamics: Impact on evaluative intragroup differentiation and commitment to prescriptive norms

Two studies examined participants’ evaluations of ingroup or outgroup normative and deviant members and changes in agreement with a prescriptive norm. In Experiment 1 (N = 51), the normative target was either a full or marginal ingroup or outgroup member, and the deviant was a full member. In Experiment 2 (N = 113), both targets were full or marginal members, or one was a full member and the other was marginal. As predicted, maximal upgrading of normative members and downgrading of deviant members, as well as endorsement of the norm, occurred when both targets were full ingroup members. In contrast, the deviant was derogated least and the deviant’s position was endorsed most when the deviant target was a full ingroup member and the normative target was a marginal ingroup member. Evaluations of normative and deviant ingroup members mediated the effects of their role on participants’ agreement with the norm

ESTUDIO REOLÓGICO DE LOS FLUIDOS VISCOELÁSTICOS SURFACTANTES UTILIZADOS EN OPERACIONES DE FRACTURAMIENTO HIDRÁULICO

Resumen Con el pasar de los años, la producción de los campos de petróleo muestra una tendencia a declinar debido a factores que se presentan en la operación de un campo, por esta razón es necesaria la implementación de técnicas de estimulación que ayuden a incrementar la producción de hidrocarburos, el cual es el objetivo principal de la industria.Entre muchas técnicas que se han probado con éxito, la más destacada es el fracturamiento hidráulico. Siendo una de las técnicas de estimulación de pozos en yacimientos de hidrocarburos, más utilizada; su finalidad es resolver problemas que se relacionan con la baja productividad, atribuida generalmente a daño inducido en la formación y/o baja permeabilidad del yacimiento. Esta técnica ha logrado estimular la producción de pozos de petróleo de una manera excepcional pues los logros alcanzados han superado en gran medida las expectativas de producción, razón por la cual continúa siendo una de las técnicas más usadas alrededor del mundo.Actualmente se han adelantado investigaciones que brindan información para optimizar esta técnica logrando la introducción a la industria del uso de fluidos llamados viscoelásticos surfactantesque en un principio fueron creados para limpieza de pozos pero que por sus características tanto físicas como químicas, además de su comportamiento, son usados como fluidos de fractura al igual que en otras operaciones de estimulación de pozos. Es importante destacar el uso de los VES para optimizar las operaciones de fracturamiento hidráulico, pues exhiben excelentes propiedades de transporte y soporte del material propante, siendo más compatibles con la formación, por cuanto su proceso de degradación no genera residuo algunomaximizando la permeabilidad retenida en el empaque de grava. En este artículo se presenta un estudio de las propiedades reológicas de los fluidos viscoelásticos surfactantes y cómo influyen en las operaciones de fracturamiento hidráulico. Palabras clave: fluidos viscoelásticos, fluidos VES, reología, fracturamiento hidráulico, fluido de fractura. Abstract. Over the years the production of oil fields have a tendency to decline due to factors that arise in the operation of a field, therefore it is necessary to implement stimulation techniques to help increase oil production, which is the main objective of the industry.Among many techniques that have been proved successfully, the most prominent is the hydraulic fracturing. As one of the well stimulation techniques in hydrocarbon reservoirs most used its purpose is to solve problems related to low productivity, usually attributed to damage induced in the formation and / or low permeability reservoir. This technique has been successful in stimulating oil production wells in an exceptional way because the achievements have greatly exceeded the expectations created by the engineers, for this reason is still one of the most common techniques used around the world.Currently have been developed research that will provide information to optimize this technique making the introduction into to the industry of the so-called viscoelastic fluids which, were originally created to clean wells but due to their physical and chemical characteristics as well as their behavior are used as fracture fluids in hydraulic fracturing operations and in other well stimulation operations. Importantly, the use of VES to optimize the technique mentioned above because it exhibits excellent transport properties and proppant material support, being more compatible with the formation, because its degradation process does not generate any waste and may return to the surface.This article presents a study of the rheological properties of viscoelastic surfactant fluids and how they influence the hydraulic fracturing operations. Keywords: viscoelastic fluids, VES fliuds, rheology, hydraulic fracturing, fracture fluid.  

Laparoscopic versus open colectomy for acute complicated diverticulitis: a comparative study of outcomes - a systematic review

Acute complicated diverticulitis presents a more severe form of diverticular illness frequently needing urgent medical intervention and possibly surgical therapy. The aim of this review is to gather conclusive evidence from the literature comparing laparoscopic techniques to open and conservative ones in order to determine the most effective treatment plan for complicated diverticulitis. Online databases like PubMed, Google Scholar, Cochrane, Elsevier and many others were systematically searched according to an inclusion criterion to obtain a total of 13 studies to be included in the review. 8/13 studies presented short term outcomes while 5/13 studies concluded with long term outcomes following index surgeries. Based on the end results, it can be concluded that laparoscopic surgery, in particular laparoscopic colon resection is superior to other techniques in treating complicated diverticulitis in terms of fewer short-term complications, low mortality rate better quality of life with few recurrence rates. However, other approaches have their own advantages and can be given priority based on the unique presentation of each case. The clinicians are advised to make informed decisions keeping in view all the patient and disease associated aspects

A strategy for scaling up access to comprehensive care in adults with Chagas disease in endemic countries: The Bolivian Chagas Platform

BACKGROUND: Bolivia has the highest prevalence of Chagas disease (CD) in the world (6.1%), with more than 607,186 people with Trypanosoma cruzi infection, most of them adults. In Bolivia CD has been declared a national priority. In 2009, the Chagas National Program (ChNP) had neither a protocol nor a clear directive for diagnosis and treatment of adults. Although programs had been implemented for congenital transmission and for acute cases, adults remained uncovered. Moreover, health professionals were not aware of treatment recommendations aimed at this population, and research on CD was limited; it was difficult to increase awareness of the disease, understand the challenges it presented, and adapt strategies to cope with it. Simultaneously, migratory flows that led Bolivian patients with CD to Spain and other European countries forced medical staff to look for solutions to an emerging problem. INTERVENTION: In this context, thanks to a Spanish international cooperation collaboration, the Bolivian platform for the comprehensive care of adults with CD was created in 2009. Based on the establishment of a vertical care system under the umbrella of ChNP general guidelines, six centres specialized in CD management were established in different epidemiological contexts. A common database, standardized clinical forms, a and a protocolized attention to adults patients, together with training activities for health professionals were essential for the model success. With the collaboration and knowledge transfer activities between endemic and non-endemic countries, the platform aims to provide care, train health professionals, and create the basis for a future expansion to the National Health System of a proven model of care for adults with CD. RESULTS: From 2010 to 2015, a total of 26,227 patients were attended by the Platform, 69% (18,316) were diagnosed with T. cruzi, 8,567 initiated anti-parasitic treatment, more than 1,616 health professionals were trained, and more than ten research projects developed. The project helped to increase the number of adults with CD diagnosed and treated, produce evidence-based clinical practice guidelines, and bring about changes in policy that will increase access to comprehensive care among adults with CD. The ChNP is now studying the Platform's health care model to adapt and implement it nationwide. CONCLUSIONS: This strategy provides a solution to unmet demands in the care of patients with CD, improving access to diagnosis and treatment. Further scaling up of diagnosis and treatment will be based on the expansion of the model of care to the NHS structures. Its sustainability will be ensured as it will build on existing local resources in Bolivia. Still human trained resources are scarce and the high staff turnover in Bolivia is a limitation of the model. Nevertheless, in a preliminary two-years-experience of scaling up this model, this limitations have been locally solved together with the health local authorities

Inflammatory and Repair Serum Biomarker Pattern. Association to Clinical Outcomes in COPD

Background: The relationship between serum biomarkers and clinical expressions of COPD is limited. We planned to further describe this association using markers of inflammation and injury and repair. Methods: We studied lung function, comorbidities, exercise tolerance, BODE index, and quality of life in 253 COPD patients and recorded mortality over three years. Serum levels of Interleukins 6,8 and16, tumor necrosis factor alpha (TNF α) [inflammatory panel], vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) [injury and repair panel] and pulmonary and activation-regulated chemokine (PARC/CCL-18) and monocyte chemotactic protein 1 (MCP-1/CCL2) [chemoattractant panel] were measured. We related the pattern of the biomarker levels to minimal clinically important differences (MCID) using a novel visualization method [ObServed Clinical Association Results (OSCAR) plot]. Results: Levels of the inflammatory markers IL-6, TNF α were higher and those of injury and repair lower (p < 0.01) with more advanced disease (GOLD 1 vs. 4). Using the OSCAR plot, we found that patients in the highest quartile of inflammatory and lowest quartile of injury and repair biomarkers level were more clinically compromised and had higher mortality (p < 0.05). Conclusions: In COPD, serum biomarkers of inflammation and repair are distinctly associated with important clinical parameters and survival

Justiça popular em bullies: Atribuições de responsabilidade, raiva, e controlo social ineficaz como combustível para ação coletiva não-normativa = Popular justice on bullies: Attributions of responsibility, anger, and ineffective social control as fuel for non-normative collective action

O bullying escolar raramente tem sido analisado através do ponto de vista da sociedade em geral. No entanto, nas situações em que o agressor atrai a atenção mediática, verificam-se reações coletivas muito severas. Neste trabalho, analisámos os processos subjacentes à ação coletiva não-normativa que muitas vezes emerge perante situações de bullying. Após um vídeo amador que mostrava uma destas situações se ter tornado viral em Portugal, pedimos a 350 participantes que preenchessem um questionário sobre o tema. Os resultados mostraram que a atribuição de responsabilidade ao agressor predizia a concordância com medidas de justiça popular, e que isto era mediado por emoções de raiva, e moderado pela perceção de ineficácia dos mecanismos de controlo social. Mais especificamente, quanto maior a responsabilidade atribuída ao agressor, maior a raiva sentida, o que levava a um maior grau de concordância com medidas de justiça popular. Para além disso, este efeito era maior para os participantes que acreditavam que os mecanismos formais de controlo social eram ineficazes. Os resultados foram discutidos à luz da sua contribuição para o combate ao bullying, e da literatura sobre desvio, controlo social, e ação coletiva. School bullying has seldom been analyzed through the perspective of society in general. However, severe collective reactions often emerge towards bullies when they attract public attention. In this paper, we analyze the process underlying these non-normative forms of collective action triggered by bullying. A survey was presented to 350 Portuguese participants following the release of a viral video depicting a bullying situation. Results showed that assignment of responsibility to the aggressor predicted agreement with popular justice, which was mediated by anger and moderated by perceived ineffectiveness of social control. Specifically, greater responsibility attributed to aggressors yielded greater anger towards them, which, in turn, triggered more agreement with popular justice. Moreover, this effect was stronger for participants who believed that formal social control mechanisms were ineffective. We discuss these results in light of their contribution for tackling bullying, as well as for the literature on deviance, social control and collective action

Comparative structural response of two steel bridges constructed 100 years apart

This paper presents a comparative numerical analysis of the structural behaviour and seismic performance of two existing steel bridges, the Infiernillo II Bridge and the Pinhao Bridge, one located in Mexico and the other in Portugal. The two bridges have similar general geometrical characteristics, but were constructed 100 years apart. Three-dimensional structural models of both bridges are developed and analysed for various load cases and several seismic conditions. The results of the comparative analysis between the two bridges are presented in terms of natural frequencies and corresponding vibration modes, maximum stresses in the structural elements and maximum displacements. The study is aimed at determining the influence of a 1 century period in material properties, transverse sections and expected behaviour of two quite similar bridges. In addition, the influence of the bearing conditions in the global response of the Pinhao Bridge was evaluated

Parallax Motion Effect Generation Through Instance Segmentation And Depth Estimation

Stereo vision is a growing topic in computer vision due to the innumerable opportunities and applications this technology offers for the development of modern solutions, such as virtual and augmented reality applications. To enhance the user's experience in three-dimensional virtual environments, the motion parallax estimation is a promising technique to achieve this objective. In this paper, we propose an algorithm for generating parallax motion effects from a single image, taking advantage of state-of-the-art instance segmentation and depth estimation approaches. This work also presents a comparison against such algorithms to investigate the trade-off between efficiency and quality of the parallax motion effects, taking into consideration a multi-task learning network capable of estimating instance segmentation and depth estimation at once. Experimental results and visual quality assessment indicate that the PyD-Net network (depth estimation) combined with Mask R-CNN or FBNet networks (instance segmentation) can produce parallax motion effects with good visual quality.Comment: 2020 IEEE International Conference on Image Processing (ICIP), Abu Dhabi, United Arab Emirate