Natural history of a visceral leishmaniasis outbreak in highland Ethiopia

In May 2005, visceral leishmaniasis (VL) was recognized for the first time in Libo Kemken, Ethiopia, a highland region where only few cases had been reported before. We analyzed records of VL patients treated from May 25, 2005 to December 13, 2007 by the only VL treatment center in the area, maintained by Médecins Sans Frontières-Ethiopia, Operational Center Barcelona-Athens. The median age was 18 years; 77.6% were male. The overall case fatality rate was 4%, but adults 45 years or older were five times as likely to die as 5-29 year olds. Other factors associated with increased mortality included HIV infection, edema, severe malnutrition, pneumonia, tuberculosis, and vomiting. The VL epidemic expanded rapidly over a several-year period, culminating in an epidemic peak in the last third of 2005, spread over two districts, and transformed into a sustained endemic situation by 2007

Sample bias, weights and efficiency of weights in a continuous web voluntary survey

Using micro data from a continuous voluntary web survey, the Wage Indicator, the paper analyses the type of bias that such a sampling method produces and discusses a methodology to weight the data in order to correct such bias and make it possible to run analyses to obtain results and conclusions applicable to the whole population. In order to evaluate the efficiency of the weighting methodology to solve the potential sample bias of web surveys, the results are confronted with those obtained from an alternative standard labour survey dealing with the same issues. Since the Wage Indicator is a survey oriented to labour market issues, we considered that a labour market case study was most appropriate for the evaluation of the results. The method of evaluation followed is to calculate mean salaries, inequality indexes and salary regressions before and after implementing the weights using the Wage Indicator Survey data for Spain. The results are compared with those reached using the Structure of Earnings Survey, a wage survey run by the Spanish Statistical Institute

Survey vs Scraped Data: Comparing Time Series Properties of Web and Survey Vacancy Data

This paper studies the relationship between a vacancy population obtained from web crawling and vacancies in the economy inferred by a National Statistics Office (NSO) using a traditional method. We compare the time series properties of samples obtained between 2007 and 2014 by Statistics Netherlands and by a web scraping company. We find that the web and NSO vacancy data present similar time series properties, suggesting that both time series are generated by the same underlying phenomenon: the real number of new vacancies in the economy. We conclude that, in our case study, web-sourced data are able to capture aggregate economic activity in the labor market

Cross-Comparison of Climate Change adaptation Strategies Across Large River Basins in Europe, Africa and Asia

A cross-comparison of climate change adaptation strategies across regions was performed, considering six large river basins as case study areas. Three of the basins, namely the Elbe, Guadiana, and Rhine, are located in Europe, the Nile Equatorial Lakes region and the Orange basin are in Africa, and the Amudarya basin is in Central Asia. The evaluation was based mainly on the opinions of policy makers and water management experts in the river basins. The adaptation strategies were evaluated considering the following issues: expected climate change, expected climate change impacts, drivers for development of adaptation strategy, barriers for adaptation, state of the implementation of a range of water management measures, and status of adaptation strategy implementation. The analysis of responses and cross-comparison were performed with rating the responses where possible. According to the expert opinions, there is an understanding in all six regions that climate change is happening. Different climate change impacts are expected in the basins, whereas decreasing annual water availability, and increasing frequency and intensity of droughts (and to a lesser extent floods) are expected in all of them. According to the responses, the two most important drivers for development of adaptation strategy are: climate-related disasters, and national and international policies. The following most important barriers for adaptation to climate change were identified by responders: spatial and temporal uncertainties in climate projections, lack of adequate financial resources, and lack of horizontal cooperation. The evaluated water resources management measures are on a relatively high level in the Elbe and Rhine basins, followed by the Orange and Guadiana. It is lower in the Amudarya basin, and the lowest in the NEL region, where many measures are only at the planning stage. Regarding the level of adaptation strategy implementation, it can be concluded that the adaptation to climate change has started in all basins, but progresses rather slowl

Visual suppression in intermittent exotropia during binocular alignment.

PURPOSE To investigate the cortical mechanisms that prevent diplopia in intermittent exotropia (X(T)) during binocular alignment (orthotropia). METHODS The authors studied 12 X(T) patients aged 5 to 22 years. Seventy-five percent had functional stereo vision with stereoacuity similar to that of 12 age-matched controls (0.2-3.7 min arc). Identical face images were presented to the two eyes for 400 ms. In one eye, the face was presented at the fovea; in the other, offset along the horizontal axis with up to 12° eccentricity. The task was to indicate whether one or two faces were perceived. RESULTS All X(T) patients showed normal diplopia when the nonfoveal face was presented to nasal hemiretina, though with a slightly larger fusional range than age-matched controls. However, 10 of 12 patients never experienced diplopia when the nonfoveal face was presented to temporal hemiretina (i.e., when the stimulus simulated exodeviation). Patients showed considerable variability when the single image was perceived. Some patients suppressed the temporal stimulus regardless of which eye viewed it, whereas others suppressed a particular eye even when it viewed the foveal stimulus. In two patients, the simulated exodeviation might have triggered a shift from normal to anomalous retinal correspondence. CONCLUSIONS Antidiplopic mechanisms in X(T) can be reliably triggered by purely retinal information during orthotropia, but the nature of these mechanisms varies between patients

Relationship between cellular response and behavioral variability in bacterial chemotaxis

Bacterial chemotaxis in Escherichia coli is a canonical system for the study of signal transduction. A remarkable feature of this system is the coexistence of precise adaptation in population with large fluctuating cellular behavior in single cells (Korobkova et al. 2004, Nature, 428, 574). Using a stochastic model, we found that the large behavioral variability experimentally observed in non-stimulated cells is a direct consequence of the architecture of this adaptive system. Reversible covalent modification cycles, in which methylation and demethylation reactions antagonistically regulate the activity of receptor-kinase complexes, operate outside the region of first-order kinetics. As a result, the receptor-kinase that governs cellular behavior exhibits a sigmoidal activation curve. This curve simultaneously amplifies the inherent stochastic fluctuations in the system and lengthens the relaxation time in response to stimulus. Because stochastic fluctuations cause large behavioral variability and the relaxation time governs the average duration of runs in response to small stimuli, cells with the greatest fluctuating behavior also display the largest chemotactic response. Finally, Large-scale simulations of digital bacteria suggest that the chemotaxis network is tuned to simultaneously optimize the random spread of cells in absence of nutrients and the cellular response to gradients of attractant.Comment: 15 pages, 4 figures, Supporting information available here http://cluzel.uchicago.edu/data/emonet/arxiv_070531_supp.pd

Barley β-glucan accelerates wound healing by favoring migration versus proliferation of human dermal fibroblasts

β-Glucans are considered candidates for the medication in different human pathologies. In this work, we have purified β-glucan from a selected barley line and tested their effects in primary human dermal fibroblasts. Unexpectedly, we have observed that this compound promoted a short-transitory proliferation arrest at 24 h after its addition on the medium. We have determined that this transitory arrest was dependent on the cell-cycle regulator protein Retinoblastoma. Moreover, dermal fibroblasts increase their migration capacities at 24 h after barley β-glucan addition. Also, we have described that barley β-glucan strongly reduced the ability of fibroblasts to attach and to spread on cell plates. Our data indicates that barley β-glucan signal induces an early response in HDF cells favoring migration versus proliferation. This feature is consistent with our observation that the topical addition of our barley β-glucan in vivo accelerates the wound closure in mouse skin