Evaluation of VirB binding site contribution to the regulation of the icsP promoter in Shigella flexneri

Shigella species are gram-negative, rod-shaped bacteria that are closely related to Escherichia coli. Virulent Shigella spp. are intracellular pathogens that invade, replicate and spread through epithelial cells of the lower intestine and cause bacillary dysentery in humans. This disease is characterized by a robust inflammatory response that results in fever, abdominal pain, and bloody diarrhea (3). According to the CDC, approximately 14,000 cases are reported each year in the United States alone. This number however, does not reflect the actual incidence of this disease as many cases go unreported. The molecular pathogenesis of these bacteria lies in the large virulence plasmid (~230-kb) that is found in all virulent Shigella spp. Two key virulence determinants include the ability to invade colonic epithelia (mediated by the ipa-mxi-spa gene locus) and the ability to spread to adjacent cells, a process known as actin-based-motility (mediated and controlled by icsA and icsP respectively). These events are largely regulated by VirB, a transcription factor (2, 3). Canonically, transcription factors are known to bind sequences proximal to the transcriptional start site (within 200-bp). Recent work has focused on the regulation of icsP (encodes a protease of the outer membrane) by VirB and has shed light on a novel regulatory strategy, whereby VirB regulates the activation of icsP from sites located more than 1-kb upstream of the transcriptional start site (1). Nine putative VirB binding sites have been found upstream of the icsP gene. This work seeks to characterize the contribution made by these putative binding sites to the VirB-dependent regulation of icsP

Combination of VirB binding site mutations to evaluate collective impact on icsP promoter activity in Shigella flexneri

Shigella flexneri is a gram-negative, invasive bacterial pathogen that afflicts the human colonic epithelium, causing shigellosis, an illness triggering severe dysentery. The World Health Organization cites the disease burden of shigellosis near 90 million episodes and 108,000 deaths per year. The motility and spread of Shigella is modulated by icsP, a virulence gene. The transcription factor VirB positively regulates many virulence genes encoded by the Shigella virulence plasmid. Two distal binding sites of VirB have been shown to regulate the promoter activity of icsP, despite their location of more than 1 kb upstream of the transcription start site. Five VirB binding sites are located between these two sites and the transcription start site, and two are located in close proximity downstream of the transcription start site. Investigation into the impact of the VirB binding sites is part of a larger effort to understand the workings of VirB, which is the major switch that controls virulence gene expression in Shigella

Comparison of structure function and detrended fluctuation analysis of wind time series

A multifractal (MF) analysis in time scale has been applied to three wind speed series presenting a different pattern. The temporal scaling properties of the records, registered each 10 minutes, were studied using two different methods, structure function (SF) and detrended fluctuation analysis (DFA), to establish a comparison of the results and their interpretation in the geostrophic turbulence context. A systematic analysis of the exponent of the structure function (ζ(q)) and the generalized Hurst exponents (H(q)) gave, in general terms, equivalent results when a comparison is applied among the three months. However MF DFA presented statistically more robust results. This allowed us to see a clear difference between the parameters studied for each month: linear component of ζ(q) (ζ(q = 1) = H), intermittency of the wind series (μ), deviation from linear structure function (λ), Hurst exponent (H(q = 2)) and H(q) dependence on q (ΔH)

Can facilitation influence the spatial genetics of the beneficiary plant population?

1. Plant facilitation is a positive interaction where a nurse or nurse plant community alters the local conditions, improving the life-time fitness of other beneficiary plants. In stressful environments, a common consequence is the formation of discrete vegetation patches under nurse plants, surrounded by open space. The consequences of such spatial patterns have been studied mostly at the community level. 2. At the population level, facilitation causes a distribution of beneficiary individuals that could have intra-specific genetic consequences. The spatial patchiness and the increase in local aggregation can potentially affect the population fine-scale genetic structure. In addition, marked microenvironmental differences under nurses versus outside could lead to plastic phenotypic variation between facilitated and non-facilitated individuals, as for example reproductive asynchrony, potentially producing assortative mating. 3. This study tests the hypothesis that plant facilitation can have genetic consequences for the population of a beneficiary plant (Euphorbia nicaeensis) by affecting its spatial genetic structure and mating patterns between subpopulations of facilitated and non-facilitated individuals. 4. Facilitation in this system creates an aggregated distribution of beneficiary individuals compared to a minority of non-facilitated individuals that grow on the open ground. Facilitation also leads to slight phenological differences mediated by strong microenvironmental differences created by nurses compared to the open ground. Yet a molecular analysis showed that, although there is fine scale spatial genetic structure in this system, there is no evidence that it is caused by facilitation. Numerical simulations further showed that spatial genetic patterns in the population are little influenced by the phenological mismatch observed in the field. 5. Synthesis. Facilitation leads to the strong spatial aggregation of beneficiary plants and desynchronizes their flowering phenology, but the magnitude of these effects is not enough to have local genetic consequences in our study system. Facilitation seems thus to have a homogenizing role by allowing the persistence of a diverse gene pool in populations in harsh environments, rather than fomenting genetic differentiation. Further information on other systems where facilitation produces stronger spatial or phenological effects on facilitated plants is needed to fill the large knowledge gap we have on the genetic effects of facilitation

An attempt to reproduce a previous meta-analysis and a new analysis regarding the impact of directly observed therapy on tuberculosis treatment outcomes

Directly observed therapy (DOT) is almost universally used for the treatment of TB. Several meta-analyses using different methods have assessed the effectiveness of DOT compared to self-administered therapy (SAT). The results of these meta-analyses often conflict with some concluding DOT is superior and others that there is little or no difference. Meta-analyses can guide policymaking, but such analyses must be reliable. To assess the validity of a previous meta-analysis, we tried to reproduce it. We encountered problems with the previous analysis that did not allow for a meaningful reproduction. We describe the issues we encountered here. We then performed a new meta-analysis comparing the treatment outcomes of adults given treatment with SAT versus DOT. Outcomes in the new analysis are loss to follow-up, treatment failure, cure, treatment completed, and all-cause mortality. All data, documentation, and code used to generate our results is provided. Our new analysis included four randomized and three observational studies with 1603 and 1626 individuals respectively. The pooled relative risks (RR) are as follows: Lost to follow-up (RR = 1.2, 95% CI 0.9, 1.7), Treatment Failure (RR = 1.1, 95% CI 0.6, 2), Cure (RR = 0.9, 95% CI 0.8, 1.1), Treatment Completion (RR = 1, 95% CI 0.9, 1.1), Mortality (RR = 0.9, 95% CI 0.6, 1.3). Based on data from our new meta-analysis, the magnitude of the difference between DOT and SAT for all reported outcomes is small, and none of the differences are statistically significant

Methodological approach for mineralogical characterization of tailings from a Cu(Au,Ag) skarn type deposit using QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy)

Skarn type deposits are important potential resources for Cu, Au, and Ag as well as other strategic metals, which require accurate characterization of the mineralogy, texture and grade for successful processing and environmental management. The mineralogy of these deposits and of the resulting tailings has traditionally been examined using transmitted light microscopy, cathodoluminescence, X-ray diffraction, scanning electron microscopy, and electron probe microanalysis. In the present study, the Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN (R)) technology was applied to rapidly acquire spatially resolved mineralogical data from tailings associated with a Cu(Au,Ag) skarn type deposit. The resulting modal and textural data provided relevant additional information on the distribution of the ore minerals, including detail on the trace minerals, grain size distributions, and mineral associations. The following benefits of detailed mineralogical knowledge from this study can be pointed out it improves the lithotyping of these complex deposit types and will benefit their ore processing strategies; it allows inferences to be made about the environmental behavior of the tailings, namely the acid mine drainage potential; it provides data about deportment of penalty and toxic elements, which are specifically As, Te, and Sb. Thus, particular applications of QEMSCAN include assessments of the acid consumption of the mineral assemblages (mainly assured due to calcite and dolomite) and of the abundance, distribution and mobility of potentially toxic elements, such as As

Travel-Related Monkeypox Outbreaks in the Era of COVID-19 Pandemic: Are We Prepared?

Several neglected infectious pathogens, such as the monkeypox virus (MPXV), have re-emerged in the last few decades, becoming a global health burden. Despite the incipient vaccine against MPXV infection, the global incidence of travel-related outbreaks continues to rise. About 472 confirmed cases have been reported in 27 countries as of 31 May 2022, the largest recorded number of cases outside Africa since the disease was discovered in the early 1970s

Reforma curricular de la carrera de enfermería: lineamientos para el proceso

La carrera de Enfermería en este proceso de reforma curricular trabajo en torno al compromiso que tiene con la transformación de la realidad nacional, generando cambios en la sociedad con impacto en la salud del individuo y de los colectivos y con la construcción del saber propio de la profesión a partir del análisis de los conocimientos, metodologías y procedimientos de abordaje del cuidado de Enfermería, como objeto de la profesiónEje: Educación Universitaria ReflexionesRed de Universidades con Carreras en Informática (RedUNCI

Reforma curricular de la carrera de enfermería: lineamientos para el proceso

La carrera de Enfermería en este proceso de reforma curricular trabajo en torno al compromiso que tiene con la transformación de la realidad nacional, generando cambios en la sociedad con impacto en la salud del individuo y de los colectivos y con la construcción del saber propio de la profesión a partir del análisis de los conocimientos, metodologías y procedimientos de abordaje del cuidado de Enfermería, como objeto de la profesiónEje: Educación Universitaria ReflexionesRed de Universidades con Carreras en Informática (RedUNCI