4,812 research outputs found

    Significant correlation of angiotensin converting enzyme and glycoprotein IIIa genes polymorphisms with unexplained recurrent pregnancy loss in north of Iran

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    Background: Spontaneous abortion is considered as the most complex problem during pregnancy. Thrombophilia is resumed as a cause of recurrent pregnancy loss (RPL). Glycoprotein IIIa (GPIIIa) gene is involved in thrombosis and abortion. Angiotensin converting enzyme (ACE) converts angiotensin I to angiotensin II and is involved in thrombosis. The most common polymorphism in this gene is the insertion/deletion (I/D). Objective: In this study, we analyzed the association between ACE I/D and GPIIIa c.98C >T polymorphisms in women with unexplained RPL from the north of Iran. Materials and Methods: Sample population consisted of 100 women with unexplained RPL and 100 controls. The ACE I/D and GPIIIa c.98C>T polymorphisms were genotyped by TETRA-ARMS PCR. The association between genotypes frequency and RPL were analyzed using χP2P and exact fisher tests. Associated risk with double genotype combinations was also investigated by binary logistic regression. Results: There was significant association between ACE DD genotype and RPL (OR=2.04; 95% CI=0.94-4.44; p=0.036). ACE D Allele was also significantly associated with the RPL (OR=1.59; 95% CI=1.05-2.41; p=0.013). No significant association was observed between GPIIIa c.98C>T polymorphism and RPL. Conclusion: ACE I/D polymorphism may probably be a prognostic factor in female family members of women with the history of recurrent abortion. © 2016, Research and Clinical Center for Infertitlity. All Rights Reserved

    Non-linear stress response of non-gap-spanning magnetic chains suspended in a Newtonian fluid under oscillatory shear test : A direct numerical simulation

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    The corresponding author wishes to express his sincerest thanks to the Iran National Science Foundation (INSF) for supporting this work under Contract Number 92021291.Peer reviewedPostprintPublisher PD

    A SPH solver for simulating paramagnetic solid fluid interaction in the presence of an external magnetic field

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    Acknowledgment The first two authors wish to express their sincerest thanks to Iran National Science Foundation (INSF) for supporting this work under Contract Number 92021291.Peer reviewedPostprin

    A Compact Versatile Microbial Fuel Cell From Paper

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    Microbial fuel cells (MFCs) have been a potential green energy source for a long time but one of the problems is that either the technology must be used on a large scale or special equipment have been necessary to keep the fuel cells running such as syringe pumps. Paper-based microbial fuel cells do not need to have a syringe pump to run and can run entirely by themselves when placed in contact with the fluids that are necessary for it to run. Paper-based microbial fuel cells are also more compact than traditional MFCs since the device doesn’t need any external equipment to run. The goal of this paper is to develop a microbial fuel cell that does not require a syringe pump to function. This is done by layering chromatography paper with wax design printed onto it. This restricts the fluids to a specific flow path allowing it to act like the tubes in a typical microbial fuel cell device by delivering the fluids to the chamber. The fluids are picked up by tabs that sit in the fluid and use capillary attraction to flow up the tab and into the device. The fluids are directed to the chambers where the chemical and biological processes take place. These flows are then directed out of the device so that they are taken to a waste container and out of the system. Our microliter scale paper-based microbial fuel cell creates a significant current that is sustained for a period of time and can be repeated. A paper-based microbial fuel cell also has a fast response time. These results mean that it could be possible for a set of paper-based microbial fuel cells to create a power density capable of powering small, low power circuits when used in series or parallel. In this paper, we discuss the fabrication and experimental results of our paper-based microbial fuel cell. Also there will be a discussion of how paper-based microbial fuels cells compare to the traditional microbial fuel cells and how they could be used in the future

    The Role of Perceived Organizational Support on Relationship between Job Stress and Emotional Exhaustion with Turnover among Nurses

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    مقدمه: این پژوهش با هدف بررسی رابطه استرس شغلی و فرسودگی هیجانی با تمایل به ترک خدمت‌ با توجه به نقش تعدیل‌کننده حمایت سازمانی ادراک‌شده به مرحله اجرا در آمد. مواد و روشها: جامعه آماری پژوهش پرستاران یک بیمارستان دولتی در اصفهان بودند که از میان آن‌ها صد و نود و نه نفر به شیوه سهل‌الوصول انتخاب شدند. ابزارهای پژوهش شامل پرسشنامه استرس شغلی، فرسودگی هیجانی، حمایت سازمانی ادراک شده و ترک خدمت بودند. داده‌ها از طریق ضریب همبستگی پیرسون و تحلیل رگرسیون سلسله مراتبی تحلیل گردید. یافته ها: بین استرس شغلی با فرسودگی هیجانی، بین استرس شغلی با حمایت سازمانی ادارک شده، بین استرس شغلی با ترک خدمت، بین فرسودگی هیجانی با حمایت سازمانی ادراک شده، بین فرسودگی هیجانی با ترک خدمت و بین حمایت سازمانی ادراک شده با ترک خدمت رابطه (معنادار) وجود دارد. نتایج تحلیل رگرسیون نیز نشان داد که از میان دو مولفه استرس شغلی و فرسودگی هیجانی‌، فقط ابهام نقش قادر به پیش‌بینی (معنادار) حمایت سازمانی ادراک شده و طی دو‌گام به ترتیب فرسودگی هیجانی و گرانباری و تعارض نقش قادر به پیش‌بینی (معنادار) ترک خدمت هستند. نتایج تحلیل رگرسیون سلسله مراتبی نشان داد که حمایت سازمانی ادراک شده قادر به تعدیل‌ رابطه ابهام نقش با ترک خدمت است ولی رابطه بین فرسودگی هیجانی با ترک خدمت را تعدیل نمی‌نماید. نتیجه گیری: مدیران بیمارستان‌ها باید از طریق تجزیه و تحلیل شغل و آماده‌سازی شرح وظایف صریح، روشن و بدون ابهام تلاش نمایند تا از سطح ابهام نقش در کارکنان و پرستاران کاسته و احساس حمایت سازمانی را در کارکنان بالا ببرند تااز ترک خدمت آنها جلوگیری نمایند

    Reducing GHGs from UK Households ‐ An Examination of Local Authority‐Level Data

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    As the threat of irreversible climate change has increased over time, the UK has focused on reducing its carbon emission levels. International treaties such as the Kyoto Protocol have informed national targets, directing the UK in reducing its climate impact. In order to achieve this an understanding of the factors that affect carbon emission reductions is vital. Identifying what dictates the success of UK local authorities in reducing their carbon emissions addresses this problem. The research uses secondary data regarding local authorities’ carbon emissions and regression analyses to explore the key factors affecting domestic emission levels over time. The research goes into further detail than existing literature through exploring sources of emissions across different sectors and analysing emissions reductions specifically between 2005-2016. Substantial and relatively consistent domestic emissions reductions were achieved in this time frame, exceeding the reductions provided by decarbonisation of the electricity grid. Standard deviations of 3% were observed in this sector, compared with 12% from Industrial & Commercial emissions. While population density demonstrated a statistically significant correlation with domestic GHG reductions, gross disposable household income was not found to be significant; however, it is a relevant indicator of total emissions levels in 2016. Through identifying these factors, suggestions to local government are made such as the implementation of region-specific strategies, tailoring these to the exact characteristics of a local authority. Furthermore, consideration of population density in conjunction with domestic and urban planning will allow for future emissions reductions to occur across the UK

    Mode-Based Sensing and Actuation Techniques for Multi-Objective Flexible Aircraft Control

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    Intelligent sensing and actuation designs are explored as a means to improve performance of a gust load alleviation control design for a flexible wing aircraft equipped with wing-shaping control surfaces. The proposed techniques rely on identification of the dominant structural modes during specified flight conditions and uses them as a basis for sensor placement and actuator utilization. Specifically, a strategy for sensor placement is discussed that uses target mode shape capture as a mean to improve state estimation quality. A second strategy that reduces the number of wing-shaping control inputs using mode and objective-based shape functions as virtual input channels is also presented. Both techniques are demonstrated in simulation of a flexible wing transport aircraft utilizing a multi-objective control system designed to suppress flexible motion, minimize gust and maneuver load, and reduce drag

    Model-Reference Adaptive Control of Distributed Lagrangian Infinite-Dimensional Systems Using Hamiltons Principle

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    This paper presents a Hamilton's principle for distributed control of infinite-dimensional systems modeled by a distributed form of the Euler-Lagrange method. The distributed systems are governed by a system of linear partial differential equations in space and time. A generalized potential energy expression is developed that can capture most physical systems including those systems that have no spatial distribution. The Hamilton's principle is applied to derive distributed feedback control methods without resorting to the standard weak-form discretization approach to convert an infinite-dimensional systems to a finite-dimensional systems. It can be shown by the principle of least action that the distributed control synthesized by the Hamilton's principle is a minimum-norm control. A model-reference adaptive control framework is developed for distributed Lagrangian systems in the presence of uncertainty. The theory is demonstrated by an application of adaptive flutter suppression control of a flexible aircraft wing

    3D mapping of young stars in the solar neighbourhood with Gaia DR2

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    We study the three dimensional arrangement of young stars in the solar neighbourhood using the second release of the Gaia mission (Gaia DR2) and we provide a new, original view of the spatial configuration of the star forming regions within 500 pc from the Sun. By smoothing the star distribution through a gaussian filter, we construct three dimensional density maps for early-type stars (upper-main sequence, UMS) and pre-main sequence (PMS) sources. The PMS and the UMS samples are selected through a combination of photometric and astrometric criteria. A side product of the analysis is a three dimensional, G-band extinction map, which we use to correct our colour-magnitude diagram for extinction and reddening. Both density maps show three prominent structures, Scorpius-Centaurus, Orion, and Vela. The PMS map shows a plethora of lower mass star forming regions, such as Taurus, Perseus, Cepheus, Cassiopeia, and Lacerta, which are less visible in the UMS map, due to the lack of large numbers of bright, early-type stars. We report the finding of a candidate new open cluster towards l,b218.5,2l, b \sim 218.5^{\circ}, -2^{\circ}, which could be related to the Orion star forming complex. We estimate ages for the PMS sample and we study the distribution of PMS stars as a function of their age. We find that younger stars cluster in dense, compact clumps, and are surrounded by older sources, whose distribution is instead more diffuse. The youngest groups that we find are mainly located in Scorpius-Centaurus, Orion, Vela, and Taurus. Cepheus, Cassiopeia, and Lacerta are instead more evolved and less numerous. Finally, we find that the three dimensional density maps show no evidence for the existence of the ring-like structure which is usually referred to as the Gould Belt.Comment: 17 pages, 17 figures, 6 appendixes; accepted for publication in A&A; image quality decreased to comply with the arXiv.org rules on file siz
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