741 research outputs found

    Local migration quantification method for scratch assays

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    The scratch assay is an in vitro technique used to assess the contribution of molecular and cellular mechanisms to cell migration. The assay can also be used to evaluate therapeutic compounds before clinical use. Current quantification methods of scratch assays deal poorly with irregular cell-free areas and crooked leading edges which are features typically present in the experimental data. We introduce a new migration quantification method, called 'monolayer edge velocimetry', that permits analysis of low-quality experimental data and better statistical classification of migration rates than standard quantification methods. The new method relies on quantifying the horizontal component of the cell monolayer velocity across the leading edge. By performing a classification test on in silico data, we show that the method exhibits significantly lower statistical errors than standard methods. When applied to in vitro data, our method outperforms standard methods by detecting differences in the migration rates between different cell groups that the other methods could not detect. Application of this new method will enable quantification of migration rates from in vitro scratch assay data that cannot be analysed using existing methods

    The Difference of Grammatical Error in Writing Recount Text Between Natural Science and Social Science Students

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    This study concerned on the difference of grammatical error in writing recount text between natural science and social science students. The objective of this study was to find out the difference of grammatical error in writing recount text between natural science and social science students. This research was conducted by using causal- comparative research. The subject of the study was the students of XI-IPA1 and XI- IPS1 of SMA Swasta Methodist Berastagi. The number of the samples was twenty eight. The techniques for data analysis were quantitative data. The t-result was 2,60 (bigger than t table 1,706). The conclusion is that there is a significant difference of grammatical error in writing recount text between natural science and social science students

    Pasture Types and Echinococcus multilocularis, Tibetan Communities

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    Our study showed that open pastures had more small mammal burrows than fenced pastures in Tibetan pastoralist communities in 2003. This characteristic was linked to a higher prevalence of Echinococcus multilocularis in dogs and indicates that pasture type may affect E. multilocularis transmission

    Variation in Competence for ZIKV Transmission by Aedes aegypti and Aedes albopictus in Mexico

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    BACKGROUND: ZIKV is a new addition to the arboviruses circulating in the New World, with more than 1 million cases since its introduction in 2015. A growing number of studies have reported vector competence (VC) of Aedes mosquitoes from several areas of the world for ZIKV transmission. Some studies have used New World mosquitoes from disparate regions and concluded that these have a variable but relatively low competence for the Asian lineage of ZIKV. METHODOLOGY/PRINCIPAL FINDINGS: Ten Aedes aegypti (L) and three Ae. albopictus (Skuse) collections made in 2016 from throughout Mexico were analyzed for ZIKV (PRVABC59-Asian lineage) VC. Mexican Ae. aegypti had high rates of midgut infection (MIR), dissemination (DIR) and salivary gland infection (SGIR) but low to moderate transmission rates (TR). It is unclear whether this low TR was due to heritable salivary gland escape barriers or to underestimating the amount of virus in saliva due to the loss of virus during filtering and random losses on surfaces when working with small volumes. VC varied among collections, geographic regions and whether the collection was made north or south of the Neovolcanic axis (NVA). The four rates were consistently lower in northeastern Mexico, highest in collections along the Pacific coast and intermediate in the Yucatan. All rates were lowest north of the NVA. It was difficult to assess VC in Ae. albopictus because rates varied depending upon the number of generations in the laboratory. CONCLUSIONS/SIGNIFICANCE: Mexican Ae. aegypti and Ae. albopictus are competent vectors of ZIKV. There is however large variance in vector competence among geographic sites and regions. At 14 days post infection, TR varied from 8-51% in Ae. aegypti and from 2-26% in Ae. albopictus

    Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005

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    BACKGROUND The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.This work was partially supported by salaries from the NOAA Coral Reef Conservation Program to the NOAA Coral Reef Conservation Program authors. NOAA provided funding to Caribbean ReefCheck investigators to undertake surveys of bleaching and mortality. Otherwise, no funding from outside authors' institutions was necessary for the undertaking of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Evaluating Over-the-Counter Household Insecticide Aerosols for Rapid Vector Control of Pyrethroid-Resistant Aedes aegypti

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    Vector control methods that mobilize and impact rapidly during dengue, Zika, and chikungunya outbreaks are urgently needed in urban contexts. We investigated whether one person using a handheld aerosolized insecticide could achieve efficacy levels comparable to targeted indoor residual spraying (TIRS), using pyrethroid-resistant Aedes aegypti in a semi-field setting with experimental houses in Mexico. The insecticide product (H24, a carbamate and pyrethroid mixture), available over-the-counter locally, was sprayed only on known Ae. aegypti–resting surfaces, for example, walls less than 1.5 m and dark hidden areas. In six identical houses with paired bedrooms, one bedroom was treated, and the other remained an untreated control. Each week for 8 weeks, 100 female pyrethroid-resistant Ae. aegypti were released in each bedroom and followed up daily. Mortality rates in treated bedrooms exceeded 90% for at least 2 weeks, and more than 80% (89.2; 95% CI: 79.98–98.35) for 3 weeks or more. Mortality rates in control houses were zero. Results demonstrate that the immediate impact of TIRS can be delivered by one person using existing products, at an estimated cost for the average household in Mexico of under US$3 per month. Triggered by early outbreak signs, dissemination via community hubs and mass/social media of instructions to treat the home immediately, with monthly re-treatment thereafter, provides a simple means to engage and empower householders. Compatible with integrated vector management strategies, it enables self-protection even if existing agencies falter, a situation exemplified by the potential impact on vector control of the restrictions imposed during the 2020 COVID-19 pandemic

    A practical and time-efficient high-intensity interval training program modifies cardio-metabolic risk factors in adults with risk factors for type ii diabetes

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    Introduction: Regular physical activity (PA) can reduce the risk of developing type 2 diabetes, but adherence to time-orientated (150 min week−1 or more) PA guidelines is very poor. A practical and time-efficient PA regime that was equally efficacious at controlling risk factors for cardio-metabolic disease is one solution to this problem. Herein, we evaluate a new time-efficient and genuinely practical high-intensity interval training (HIT) protocol in men and women with pre-existing risk factors for type 2 diabetes.Materials and methods: One hundred eighty-nine sedentary women (n = 101) and men (n = 88) with impaired glucose tolerance and/or a body mass index >27 kg m−2 [mean (range) age: 36 (18–53) years] participated in this multi-center study. Each completed a fully supervised 6-week HIT protocol at work-loads equivalent to ~100 or ~125% V˙O2 max. Change in V˙O2 max was used to monitor protocol efficacy, while Actiheartℱ monitors were used to determine PA during four, weeklong, periods. Mean arterial (blood) pressure (MAP) and fasting insulin resistance [homeostatic model assessment (HOMA)-IR] represent key health biomarker outcomes.Results: The higher intensity bouts (~125% V˙O2 max) used during a 5-by-1 min HIT protocol resulted in a robust increase in V˙O2 max (136 participants, +10.0%, p < 0.001; large size effect). 5-by-1 HIT reduced MAP (~3%; p < 0.001) and HOMA-IR (~16%; p < 0.01). Physiological responses were similar in men and women while a sizeable proportion of the training-induced changes in V˙O2 max, MAP, and HOMA-IR was retained 3 weeks after cessation of training. The supervised HIT sessions accounted for the entire quantifiable increase in PA, and this equated to 400 metabolic equivalent (MET) min week−1. Meta-analysis indicated that 5-by-1 HIT matched the efficacy and variability of a time-consuming 30-week PA program on V˙O2 max, MAP, and HOMA-IR.Conclusion: With a total time-commitment o

    ï»żBeware of scientific scams! Hints to avoid predatory publishing in biological journals

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    Our motivation for writing this editorial is to alert the academic community about the risks of predatory publishing in Biology. By piggy-backing on the open access (OA) movement and taking advantage of the “publish or perish” culture in a system that prioritises quantity over quality, predatory publishing has grown exponentially in recent years and spread across all areas of knowledge. Thousands of predatory journals and books have emerged and (provided a fee is paid) they publish scientific papers and chapters without submitting them to rigorous peer review. Now there are even predatory meetings, which promise to accept talks and publish complete works for a fee, also without reviewing them properly. These profit-making machines can damage both academia and society, putting at risk the quality of science and public trust in it, the well-being of the population, the conservation of biodiversity and the mitigation of climate change. We show the modus operandi behind invitations to contribute to predatory journals, books and meetings and suggest ways to separate the wheat from the chaff. Finally, we discuss the need to create regulatory agencies that perform a careful and systematic evaluation of the activities carried out by publishers
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