Leishmania manipulation of sand fly feeding behavior results in enhanced transmission.

In nature the prevalence of Leishmania infection in whole sand fly populations can be very low (<0.1%), even in areas of endemicity and high transmission. It has long since been assumed that the protozoan parasite Leishmania can manipulate the feeding behavior of its sand fly vector, thus enhancing transmission efficiency, but neither the way in which it does so nor the mechanisms behind such manipulation have been described. A key feature of parasite development in the sand fly gut is the secretion of a gel-like plug composed of filamentous proteophosphoglycan. Using both experimental and natural parasite-sand fly combinations we show that secretion of this gel is accompanied by differentiation of mammal-infective transmission stages. Further, Leishmania infection specifically causes an increase in vector biting persistence on mice (re-feeding after interruption) and also promotes feeding on multiple hosts. Both of these aspects of vector behavior were found to be finely tuned to the differentiation of parasite transmission stages in the sand fly gut. By experimentally accelerating the development rate of the parasites, we showed that Leishmania can optimize its transmission by inducing increased biting persistence only when infective stages are present. This crucial adaptive manipulation resulted in enhanced infection of experimental hosts. Thus, we demonstrate that behavioral manipulation of the infected vector provides a selective advantage to the parasite by significantly increasing transmission

Physicians' Practice of Dispensing Medicines: A Qualitative Study

Objectives: The physical act of giving medication to patients to administer away from a health care setting, dispensing, is normally performed by pharmacists. Dispensing of medication by physicians is a neglected patient safety issue, and having observed considerable variation in practice, the lead author sought to explore this issue further. A literature review yielded zero articles pertaining to this, so an exploratory study was commenced. The qualitative arm, relating to junior physicians' experience of, and training in, dispensing, is reported here. Methods: Focus groups were conducted to explore the beliefs, ideas, and experiences of physicians-in-training pertaining to dispensing of medication. These were recorded and transcribed. The transcriptions were thematically analyzed using the grounded theory. Results: The emergency department was the most common site of dispensing. No formal training in dispensing had been received. Informal training was variable in content and utility. The physicians felt that dispensing was part of their role. Conclusions: Despite being expected to dispense, and the patient safety issues involved in giving drugs to patients to use at home, physicians do not feel that they have been trained to undertake this task. These findings from 1 hospital raise questions about thewider quality and safety of this practic

Cryptography Export Controls - Canada\u27s Dichotomous Cryptography Policy

The effort to erect strong legal barriers to trans-national distribution of cryptography has significant gaps because strong cryptography can be obtained and used within Canada without legal restrictions. This paper advocates that Canada should exercise its discretion under the WA to diminish, not fortify, the restrictions of the export control regime

Political Predation and Economic Development

We analyze a game between citizens and governments, whose type (benevolent or predatory) is unknown to the public. Opportunistic governments mix between predation and restraint. As long as restraint is observed, political expectations improve, people enter the modern sector, and the economy grows. Once there is predation, the reputation of the government is ruined and the economy collapses. If citizens are unable to overthrow this government, the collapse is durable. Otherwise, a new government is drawn and the economy can rebound. Consistent with stylized facts, equilibrium political and economic histories are random, unstable, and exhibit long-term divergence.

Future Implementation of Adult Stem Cell Therapy in the Current Standards of Care for Myocardial Infarction

Purpose: Adult stem cells are among the new methods of approaching the treatment of myocardial tissue damage. The purpose of this review is to clarify misconceptions about stem cell therapy efficacy in clinical trials and provide a thorough understanding of adult stem cells as a future treatment for patients with myocardial infarction. Methods: A comprehensive review of literature was performed analyzing and comparing 12 clinical trials involving the treatment of patients with acute and chronic myocardial infarction. Results: Stem cell treatments carry an excellent safety profile with the ease of one-time dosing, and have shown dramatic functional improvements while reducing the recurrence of myocardial infarction and enhancing quality of life. Important changes with adult stem cell treatments include 1) formation of new cardiomyocytes, 2) sufficient and sustained improvements in cardiac output, 3) increased myocardial contractility, 4) decreased infarct zone diameter, 5) increased left ventricular function, 6) increased exercise ability, and 7) increased coronary perfusion secondary to neovascularization. Conclusion: At this time, based on the current clinical evidence, adult stem cell therapy is in a position to be considered as an optional treatment for patients with acute or chronic myocardial infarction. Adult stem cell therapy is still in experimental stages of development and the continued clinical involvement will provide more evidence to the therapeutic effects of the treatment

Estimating the Multilevel Rasch Model: With the lme4 Package

Traditional Rasch estimation of the item and student parameters via marginal maximum likelihood, joint maximum likelihood or conditional maximum likelihood, assume individuals in clustered settings are uncorrelated and items within a test that share a grouping structure are also uncorrelated. These assumptions are often violated, particularly in educational testing situations, in which students are grouped into classrooms and many test items share a common grouping structure, such as a content strand or a reading passage. Consequently, one possible approach is to explicitly recognize the clustered nature of the data and directly incorporate random effects to account for the various dependencies. This article demonstrates how the multilevel Rasch model can be estimated using the functions in R for mixed-effects models with crossed or partially crossed random effects. We demonstrate how to model the following hierarchical data structures: a) individuals clustered in similar settings (e.g., classrooms, schools), b) items nested within a particular group (such as a content strand or a reading passage), and c) how to estimate a teacher x content strand interaction.

A near real-time algorithm for flood detection in urban and rural areas using high resolution Synthetic Aperture Radar images

A near real-time flood detection algorithm giving a synoptic overview of the extent of flooding in both urban and rural areas, and capable of working during night-time and day-time even if cloud was present, could be a useful tool for operational flood relief management and flood forecasting. The paper describes an automatic algorithm using high resolution Synthetic Aperture Radar (SAR) satellite data that assumes that high resolution topographic height data are available for at least the urban areas of the scene, in order that a SAR simulator may be used to estimate areas of radar shadow and layover. The algorithm proved capable of detecting flooding in rural areas using TerraSAR-X with good accuracy, and in urban areas with reasonable accuracy