31 research outputs found

    Temperature dependence of water loss rates in scorpions and its effect on the distribution of Buthotus judaicus (Buthidae) in Israel

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    Abstract Scorpions of the family Buthidae have been shown to be more desiccation resistant in comparison with sympatric Scorpionidae species. This has been attributed to the surface-dwelling existence of the former, which unlike most other scorpion species do not avoid environmental extremes by burrowing. Still, within Buthidae, the mesic Buthotus judaicus showed better osmoregulatory capacities than the xeric Leiurus quinquestriatus, largely as a result of its high resistance to water loss. However, B. judaicus exhibited poor ability to regulate its haemolymph osmolarity at 37°C. In this study we report a sharp increase in water loss rates of B. judaicus at the 30-35°C temperature range compared to that measured for L. quinquestriatus, which could explain the poor osmoregulatory performance of the former at higher ambient temperatures. The increase in water loss rates of B. judaicus at high temperatures is not coupled with a similar increase in respiratory rate, suggesting an increase in cuticular permeability. We suggest that this increase in cuticular permeability, which may result from a relatively low critical transition temperature, contributes to limiting the distribution of B. judaicus to habitats of moderate environmental conditions

    Ipratropium/Salbutamol Comparator Versus Originator for Chronic Obstructive Pulmonary Disease Exacerbations : USA Observational Cohort Study Using the Clinformatics™ Health Claims Database

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    Acknowledgements The authors wish to thank Priyanka Raju Konduru of Observational and Pragmatic Research Institute Pte Ltd (OPRI) for assistance with data extraction. This study was sponsored and funded by Teva Branded Pharmaceutical Products, R&D, Inc. Lynanne McGuire, PhD, of MedVal Scientific Information Services, LLC (Princeton, NJ, USA) provided medical writing and editorial assistance. This manuscript was prepared according to the International Society for Medical Publication Professionals’ ‘Good Publication Practice for Communicating Company-Sponsored Medical Research: the GPP3 Guidelines.’ Funding to support medical writing assistance was provided to MedVal by Teva Branded Pharmaceutical Products R&D, Inc., Frazer, PA, USA. Teva provided a full review of the article and provided funding of the journal’s article processing charges. All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval to the version to be published. All authors had full access to all of the data in this study and take complete responsibility for the integrity of the data and accuracy of the data analysis.Peer reviewedPublisher PD

    The Effect of Density-Dependent Phase on the Locust Gut Bacterial Composition

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    The desert locust demonstrates density-dependent phase polyphenism: For extended periods it appears in a non-aggregating, non-migrating phenotype, known as the solitary phase. When circumstances change, solitary individuals may aggregate and transform to the gregarious phenotype, which have a strong propensity for generating large swarms. Previous reports have suggested a role for gut-bacteria derived volatiles in the swarming phenomenon, and suggested that locusts are capable of manipulating their gut microbiome according to their density-dependent phases. Here, we directly tested this hypothesis for the first time. Using locusts of both phases from well-controlled laboratory cultures as well as gregarious field-collected individuals; and high-throughput sequencing. We characterized the hindgut bacterial community composition in the two phases of the desert locust. Our findings demonstrate that laboratory-reared gregarious and solitary locusts maintain a stable core of Enterobacter. However, while different generations of gregarious locust experience shifts in their Enterobacter’s relative abundance; the solitary locusts maintain a stable gut microbiome, highly similar to that of the field-collected locusts. Tentative phase differences in wild populations’ microbiome may thus be an indirect effect of environmental or other factors that push the swarming individuals to homogenous gut bacteria. We therefore conclude that there are phase-related differences in the population dynamics of the locust hindgut bacterial composition, but there is no intrinsic density-dependent mechanism directly affecting the gut microbiome

    Red foliage color reliably indicates low host quality and increased metabolic load for development of an herbivorous insect

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    Abstract Plant chemical defense and coevolved detoxification mechanisms in specialized herbivorous insects are fundamental in determining many insect-plant interactions. For example, Brassicale plants protect themselves from herbivory by producing glucosinolates, but these secondary metabolites are effectively detoxified by larvae of Pierid butterflies. Nevertheless, not all Brassicales are equally preferred by these specialist herbivores. Female Pieris butterflies avoid laying eggs on anthocyanin-rich red foliage, suggesting red color is a visual cue affecting oviposition behavior. In this study, we reared P. brassicae larvae on green and red cabbage leaves, to determine whether foliage color reliably indicates host plant quality. We did not find a difference in survival rates or maximal larval body mass in the two food treatments. However, larvae feeding on red cabbage leaves exhibited significantly lower growth rates and longer durations of larval development. Interestingly, this longer development was coupled with a higher consumption rate of dry food matter. The lower ratio of body mass gain to food consumption in larvae feeding on red cabbage leaves was coupled with significantly higher (ca. 10 %) larval metabolic rates. This suggests that development on red foliage may incur an increased metabolic load associated with detoxification of secondary plant metabolites. Energy and oxygen allocation to detoxification could come at the expense of growth and thus compromise larval fitness as a result of extended development. From an evolutionary perspective, red foliage color may serve as an honest defensive cue, as it reliably indicates the plant's low quality as a substrate for larval development

    The potential of natural, photosynthetic pigments to improve the efficiency of dye-sensitized solar cells

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    Gemstone Team GrenergyCurrent photovoltaic cells incorporate silicon or synthetic dyes; however, these cells are expensive and the dyes are toxic. Our product uses natural, photosynthetic pigments to sensitize an alternative design solar cell, the dye-sensitized solar cell (DSSC). Research has shown that plant pigments are suitable sensitizers for these cells, but there is presently no good rationale to determine which pigment combinations may be most effective. Our research goal was to develop and test an absorption index for pigment selection that would increase the output of DSSCs. Our results demonstrated a positive correlation between spectral absorption of the sensitizing dye and power output of the cell. Certain pigment combinations were more effective sensitizers based on combined absorption capabilities, but resolving the mechanisms of the exact relationship requires further research and likely further development of the algorithm used to choose optimal pigment combinations

    Real-life effectiveness and safety of salbutamol Steri-Neb™ vs. Ventolin Nebules® for exacerbations in patients with COPD : Historical cohort study

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    This study was sponsored and funded by Teva Branded Pharmaceutical Products, R&D, Inc (Frazer, PA). The study was designed by academic investigators and by representatives of the sponsor, Teva Branded Pharmaceutical Products, R&D, Inc. Statistical analysis was completed by investigator VT. All authors contributed to the interpretation of data and writing or critically reviewing and revising the manuscript. All authors had access to the data and take complete responsibility for the integrity of the data and accuracy of the data analysis. The corresponding author had full access to all of the data and had final responsibility to submit for publication. This manuscript was prepared according to the International Society for Medical Publication Professionals’ Good Publication Practice for Communicating Company-Sponsored Medical Research: GPP3. Data Availability: All relevant data are within the paper, and unmatched data for all outcomes is provided in the Supporting Information files. The dataset supporting the conclusions of this article was derived from the Clinical Practice Research Datalink (www.cprd.com) and the UK Optimum Patient Care Research Database (www.opcrd.co.uk). The authors do not have permission to give public access to these databases; however, researchers may request access for their own purposes. The CPRD has broad National Research Ethics Service Committee (NRES) ethics approval for purely observational research using the primary care data and established data linkages. The OPCRD has ethical approval from the National Health Service (NHS) Research Authority to hold and process anonymized research data (Research Ethics Committee reference: 15/EM/0150). This study was approved by the Anonymised Data Ethics Protocols and Transparency (ADEPT) Committee—the independent scientific advisory committee for the OPCRD, commissioned by the Respiratory Effectiveness Group—and the Independent Scientific Advisory Committee (ISAC) for the CPRD. The study was designed, implemented, and registered in accordance with the criteria of the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP/SDPP/7645).Peer reviewedPublisher PD

    Ectopic PDX-1 Expression Directly Reprograms Human Keratinocytes along Pancreatic Insulin-Producing Cells Fate

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    BACKGROUND: Cellular differentiation and lineage commitment have previously been considered irreversible processes. However, recent studies have indicated that differentiated adult cells can be reprogrammed to pluripotency and, in some cases, directly into alternate committed lineages. However, although pluripotent cells can be induced in numerous somatic cell sources, it was thought that inducing alternate committed lineages is primarily only possible in cells of developmentally related tissues. Here, we challenge this view and analyze whether direct adult cell reprogramming to alternate committed lineages can cross the boundaries of distinct developmental germ layers. METHODOLOGY/PRINCIPAL FINDINGS: We ectopically expressed non-integrating pancreatic differentiation factors in ectoderm-derived human keratinocytes to determine whether these factors could directly induce endoderm-derived pancreatic lineage and β-cell-like function. We found that PDX-1 and to a lesser extent other pancreatic transcription factors, could rapidly and specifically activate pancreatic lineage and β-cell-like functional characteristics in ectoderm-derived human keratinocytes. Human keratinocytes transdifferentiated along the β cell lineage produced processed and secreted insulin in response to elevated glucose concentrations. Using irreversible lineage tracing for KRT-5 promoter activity, we present supporting evidence that insulin-positive cells induced by ectopic PDX-1 expression are generated in ectoderm derived keratinocytes. CONCLUSIONS/SIGNIFICANCE: These findings constitute the first demonstration of human ectoderm cells to endoderm derived pancreatic cells transdifferentiation. The study represents a proof of concept which suggests that transcription factors induced reprogramming is wider and more general developmental process than initially considered. These results expanded the arsenal of adult cells that can be used as a cell source for generating functional endocrine pancreatic cells. Directly reprogramming somatic cells into alternate desired tissues has important implications in developing patient-specific, regenerative medicine approaches

    Data from: Desiccation resistance and mating behavior in laboratory populations of Drosophila simulans originating from the opposing slopes of Lower Nahal Oren (Israel)

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    Lower Nahal Oren in Northern Israel, often referred to as "Evolution Canyon", has been proposed as a microscale model site for ecological evolution. However, conflicting mating assay and stress-resistance contribute to controversy over the Nahal Oren model. In this study we further tested the Nahal Oren model, while extending its focus from Drosophila melanogaster to its sister species, D. simulans. Using fly populations derived from the opposing canyon slopes and acclimated to laboratory conditions for 11-22 generations we did not find a significant slope effect on desiccation resistance (p=0.96) or body metabolic fuel content (p>0.43) which would indicate a genetic basis for adaptation to local resource limitation. Multiple-choice mating assays (47-48% homotypic couples in two replicate populations) did not indicate divergence from a random mating pattern between north and south-facing slope flies. In conclusion, our findings do not support divergence of D. simulans populations across Lower Nahal Oren

    Data from: An experimental evolution study confirms that discontinuous gas exchange does not contribute to body water conservation in locusts

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    The adaptive nature of discontinuous gas exchange (DGE) in insects is contentious. The classic “hygric hypothesis”, which posits that DGE serves to reduce respiratory water loss (RWL), is still the best supported. We thus focused on the hygric hypothesis in this first ever experimental evolution study of any of the competing adaptive hypotheses. We compared populations of the migratory locust (Locusta migratoria) that underwent ten consecutive generations of selection for desiccation-resistance with control populations. Selected locusts survived 36% longer under desiccation stress but DGE prevalence did not differ between these and control populations (~75%). Evolved changes in DGE properties in the selected locusts included longer cycle and interburst durations. However, in contrast to predictions of the hygric hypothesis, these changes were not associated with reduced RWL rates. Other responses observed in the selected locusts were higher body water content when hydrated and lower evaporative water loss rates. Hence, our data suggest that DGE cycle properties in selected locusts are a consequence of an evolved increased ability to store water, and thus an improved capacity to buffer accumulated CO2, rather than an adaptive response to desiccation. We conclude that DGE is unlikely to be an evolutionary response to dehydration challenge in locusts
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