Compositional Changes in Two Small Mammal Communities During Succession in Southeastern Virginia

Changes in the composition of two small mammal communities were studied during 8 and 9 years of ecological succession in southern Chesapeake. Virginia. Using monthly live-trapping on grids of similar size and history since their abandonment as agricultural fields, we learned that house mice were early colonists on one grid but not the other. Two species of herbivorous rodent and the granivorous eastern harvest mouse were numerically dominant on both grids across the study. Some species disappeared early on one grid but persisted to the end at the other. The two arboreal small mammals, golden and white-footed mice, were most predictable between sites, showing up at year 8, after significant woody elements were present on the grids. The greatest abundances of small mammals (and probably greatest total biomass too) were seen between years 4 and 6 of ecological succession

Factors associated with health-seeking behavior among migrant workers in Beijing, China

<p>Abstract</p> <p>Background</p> <p>Migrant workers are a unique phenomenon in the process of China's economic transformation. The household registration system classifies them as temporary residents in cities, putting them in a vulnerable state with an unfair share of urban infrastructure and social public welfare. The amount of pressure inflicted by migrant workers in Beijing, as one of the major migration destinations, is currently at a threshold. This study was designed to assess the factors associated with health-seeking behavior and to explore feasible solutions to the obstacles migrant workers in China faced with when accessing health-care.</p> <p>Methods</p> <p>A sample of 2,478 migrant workers in Beijing was chosen by the multi-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews between investigators and subjects. The multilevel methodology (MLM) was used to demonstrate the independent effects of the explanatory variables on health seeking behavior in migrant workers.</p> <p>Results</p> <p>The medical visitation rate of migrant workers within the past two weeks was 4.8%, which only accounted for 36.4% of those who were ill. Nearly one-third of the migrant workers chose self-medication (33.3%) or no measures (30.3%) while ill within the past two weeks. 19.7% of the sick migrants who should have been hospitalized failed to receive medical treatment within the past year. According to self-reported reasons, the high cost of health service was a significant obstacle to health-care access for 40.5% of the migrant workers who became sick. However, 94.0% of the migrant workers didn't have any insurance coverage in Beijing. The multilevel model analysis indicates that health-seeking behavior among migrants is significantly associated with their insurance coverage. Meanwhile, such factors as household monthly income per capita and working hours per day also affect the medical visitation rate of the migrant workers in Beijing.</p> <p>Conclusion</p> <p>This study assesses the influence of socio-demographic characteristics on the migrant workers' decision to seek health care services when they fall ill, and it also indicates that the current health service system discourages migrant workers from seeking appropriate care of good quality. Relevant policies of public medical insurance and assistance program should be vigorously implemented for providing affordable health care services to the migrants. Feasible measures need to be taken to reduce the health risks associated with current hygiene practices and equity should be assured in access to health care services among migrant workers.</p

An Open, Large-Scale, Collaborative Effort to Estimate the Reproducibility of Psychological Science

Reproducibility is a defining feature of science. However, because of strong incentives for innovation and weak incentives for confirmation, direct replication is rarely practiced or published. The Reproducibility Project is an open, large-scale, collaborative effort to systematically examine the rate and predictors of reproducibility in psychological science. So far, 72 volunteer researchers from 41 institutions have organized to openly and transparently replicate studies published in three prominent psychological journals in 2008. Multiple methods will be used to evaluate the findings, calculate an empirical rate of replication, and investigate factors that predict reproducibility. Whatever the result, a better understanding of reproducibility will ultimately improve confidence in scientific methodology and findings

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Transcriptomic and Reverse Genetic Analyses of Aedes aegypti Cultured Cells and Midgut Epithelial Cells upon Heme Exposure

The female mosquito Aedes aegypti requires amino acids and other nutrients like heme and iron from a blood meal to initiate vitellogenesis. Heme is a pro-oxidant molecule that acts as a nutrient, signaling molecule and in large quantities, as a toxin. Ae. aegypti has developed a few strategies to handle heme toxicity, as during a typical meal ~10mM is released into the midgut lumen. These strategies include heme aggregation to the peritrophic matrix and the degradation of heme by heme oxygenase in the cytosol of the midgut epithelium. However, despite the importance of heme as a nutrient and toxin, the mechanism of entry into the midgut epithelial cells is not currently known. As no heme transport proteins in have been identified in any dipteran, heme fluorescent analog studies were performed to visualize changes in expression caused by heme followed by global expression analyses performed in both cultured cells and midgut tissues using NGS-based RNA sequencing with the end goal to identify the gene(s) that encode the membrane bound heme import proteins responsible for heme uptake during blood digestion. A list of candidate genes for RNAi knockdown was compiled based on differential expression, expression pattern across heme treatments and number of TM domains. These genes’ function relating to heme transport was then identified through siRNA mediated knockdown and treatment with zinc mesoporphyrin to assess changes in heme uptake. A number of candidate genes were identified in 2 or more cultured cell datasets out of 4 examined. In particular, 63 candidates were identified in heme exposed midguts, 23 of which were found in at least 1 cultured cell analysis as well. However, very few highly differentially expressed genes were found in any of the analyses indicating that heme import may be controlled by a redundant system of multiple transport proteins instead of a single one. Alternatively, heme transport in Ae. aegypti could be regulated post-translationally. Knockdown of candidate genes AAEL004657 and AAEL008664 suggested a potential role in heme transport in Aag2 cultured cells, though more work is needed to localize and elucidate their specific functions

Transcriptomic and Reverse Genetic Analyses of Aedes aegypti Cultured Cells and Midgut Epithelial Cells upon Heme Exposure

The female mosquito Aedes aegypti requires amino acids and other nutrients like heme and iron from a blood meal to initiate vitellogenesis. Heme is a pro-oxidant molecule that acts as a nutrient, signaling molecule and in large quantities, as a toxin. Ae. aegypti has developed a few strategies to handle heme toxicity, as during a typical meal ~10mM is released into the midgut lumen. These strategies include heme aggregation to the peritrophic matrix and the degradation of heme by heme oxygenase in the cytosol of the midgut epithelium. However, despite the importance of heme as a nutrient and toxin, the mechanism of entry into the midgut epithelial cells is not currently known. As no heme transport proteins in have been identified in any dipteran, heme fluorescent analog studies were performed to visualize changes in expression caused by heme followed by global expression analyses performed in both cultured cells and midgut tissues using NGS-based RNA sequencing with the end goal to identify the gene(s) that encode the membrane bound heme import proteins responsible for heme uptake during blood digestion. A list of candidate genes for RNAi knockdown was compiled based on differential expression, expression pattern across heme treatments and number of TM domains. These genes’ function relating to heme transport was then identified through siRNA mediated knockdown and treatment with zinc mesoporphyrin to assess changes in heme uptake. A number of candidate genes were identified in 2 or more cultured cell datasets out of 4 examined. In particular, 63 candidates were identified in heme exposed midguts, 23 of which were found in at least 1 cultured cell analysis as well. However, very few highly differentially expressed genes were found in any of the analyses indicating that heme import may be controlled by a redundant system of multiple transport proteins instead of a single one. Alternatively, heme transport in Ae. aegypti could be regulated post-translationally. Knockdown of candidate genes AAEL004657 and AAEL008664 suggested a potential role in heme transport in Aag2 cultured cells, though more work is needed to localize and elucidate their specific functions

Molecular Imaging of Bacterial Infections in vivo: The Discrimination between Infection and Inflammation

Molecular imaging by definition is the visualization of molecular and cellular processes within a given system. The modalities and reagents described here represent a diverse array spanning both pre-clinical and clinical applications. Innovations in probe design and technologies would greatly benefit therapeutic outcomes by enhancing diagnostic accuracy and assessment of acute therapy. Opportunistic pathogens continue to pose a worldwide threat, despite advancements in treatment strategies, which highlights the continued need for improved diagnostics. In this review, we present a summary of the current clinical protocol for the imaging of a suspected infection, methods currently in development to optimize this imaging process, and finally, insight into endocarditis as a model of infectious disease in immediate need of improved diagnostic methods

Ironing out the Details: Exploring the Role of Iron and Heme in Blood-Sucking Arthropods

Heme and iron are essential molecules for many physiological processes and yet have the ability to cause oxidative damage such as lipid peroxidation, protein degradation, and ultimately cell death if not controlled. Blood-sucking arthropods have evolved diverse methods to protect themselves against iron/heme-related damage, as the act of bloodfeeding itself is high risk, high reward process. Protective mechanisms in medically important arthropods include the midgut peritrophic matrix in mosquitoes, heme aggregation into the crystalline structure hemozoin in kissing bugs and hemosomes in ticks. Once heme and iron pass these protective mechanisms they are presumed to enter the midgut epithelial cells via membrane-bound transporters, though relatively few iron or heme transporters have been identified in bloodsucking arthropods. Upon iron entry into midgut epithelial cells, ferritin serves as the universal storage protein and transport for dietary iron in many organisms including arthropods. In addition to its role as a nutrient, heme is also an important signaling molecule in the midgut epithelial cells for many physiological processes including vitellogenesis. This review article will summarize recent advancements in heme/iron uptake, detoxification and exportation in bloodfeeding arthropods. While initial strides have been made at ironing out the role of dietary iron and heme in arthropods, much still remains to be discovered as these molecules may serve as novel targets for the control of many arthropod pests

Filtering the Junk: Assigning Function to the Mosquito Non-Coding Genome

The portion of the mosquito genome that does not code for proteins contains regulatory elements that likely underlie variation for important phenotypes including resistance and susceptibility to infection with arboviruses and Apicomplexan parasites. Filtering the non-coding genome to uncover these functional elements is an expanding area of research, though identification of non-coding regulatory elements is challenging due to the lack of an amino acid-like code for the non-coding genome and a lack of sequence conservation across species. This review focuses on three types of non-coding regulatory elements: (1) microRNAs (miRNAs), (2) long non-coding RNAs (lncRNAs), and (3) enhancers, and summarizes current advances in technical and analytical approaches for measurement of each of these elements on a genome-wide scale. The review also summarizes and highlights novel findings following application of these techniques in mosquito-borne disease research. Looking beyond the protein-coding genome is essential for understanding the complexities that underlie differential gene expression in response to arboviral or parasite infection in mosquito disease vectors. A comprehensive understanding of the regulation of gene and protein expression will inform transgenic and other vector control methods rooted in naturally segregating genetic variation

Gait Symmetry Is Unaffected When Completing a Motor Dexterity Task While Using a Walking Workstation in Healthy, Young Adults

Walking workstations may counteract sedentarism in working adults; however, performing dual-task walking may affect gait or work performance. The purpose of this study was to examine gait symmetry parameters and work performance while completing a fine motor dexterity task during walking workstation use. Gait function, quantified as gait symmetry, was used to identify attentional resource allocation of the co-occurring tasks during the dual-task conditions. Eighteen college-aged students performed the Purdue Pegboard Test (PPT) with left and right hands separately while using a walking workstation at a self-selected speed. Gait symmetry indices were computed on stride length and lower extremity angular joint positions and were analyzed for a comparison of the baseline and PPT dual-task conditions. No asymmetries were found in stride length or lower extremity angular joint positions at any sub-phase of gait during walking workstation use. PPT scores decreased significantly in the walking condition compared to the seated and standing conditions. Overall, gait symmetry did not change at any lower extremity angular joint position at any sub-phase; however, there was a decrease in PPT performance, which may relate to decreased work performance. However, increased exposure to the PPT task while using a walking workstation may improve work performance over time