404 research outputs found

    PSO based power allocation for single and multi relay AF cooperative network

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    Wireless channels are generally suffering from fading. Diversity is the effective way to combat fading in wireless channels. But, the ultimate aim of diversity is to allow multiple antennas into the environment. Due to size and hardware complexity, many wireless devices are limited to one antenna. Cooperative communication is a new class of diversity, it allows single antenna users into a multi user environment to share their antennas and create virtual multiple antennas. In cooperative communication, the information is transmitted with the help of neighboring nodes, which are called relays. Cooperative diversity is based on different relaying schemes such as amplify-and-forward, decode-and-forward and coded cooperation. Cooperative transmission using relay gives better performance compared to direct transmission between the source and destination. The system performance enhances as the number of relays in the network increases and in addition the diversity order also increased. Power allocation is one of the major issues in a wireless cooperative communication for enhancing the system performance. In this work, a single and multi relay cooperative network is considered using amplify-and-forward relaying scheme. Considering the perfect channel state information (CSI), allocating power to source and relay using Particle Swarm Optimization (PSO) with minimizing as a constraint. The PSO algorithm maintains a group of particles, where each particle in the group gives a possible solution. PSO gives the best optimum value for a given problem by using objective function. Hence the implemented scheme of PSO base power allocation in cooperative network enhances the system performance

    Spitzer observations of the Hyades: Circumstellar debris disks at 625 Myr of age

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    We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160 micron due to debris disks around a sample of 45 FGK-type members of the Hyades cluster. We supplement our observations with archival 24 and 70 micron Spitzer data of an additional 22 FGK-type and 11 A-type Hyades members in order to provide robust statistics on the incidence of debris disks at 625 Myr of age an era corresponding to the late heavy bombardment in the Solar System. We find that none of the 67 FGK-type stars in our sample show evidence for a debris disk, while 2 out of the 11 A-type stars do so. This difference in debris disk detection rate is likely to be due to a sensitivity bias in favor of early-type stars. The fractional disk luminosity, L_dust/L*, of the disks around the two A-type stars is ~4.0E-5, a level that is below the sensitivity of our observations toward the FGK-type stars. However, our sensitivity limits for FGK-type stars are able to exclude, at the 2-sigma level, frequencies higher than 12% and 5% of disks with L_dust/L* > 1.0E-4 and L_dust/L* > 5.0E-4, respectively. We also use our sensitivity limits and debris disk models to constrain the maximum mass of dust, as a function of distance from the stars, that could remain undetected around our targets.Comment: 33 pages, 11 figures, accepted by Ap

    A prospective study of alcohol use patterns and short-term weight change in college freshmen

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    This is the peer reviewed version of the following article: Fazzino, T. L., Forbush, K., Sullivan, D., & Befort, C. A. (2019). A Prospective Study of Alcohol Use Patterns and Short-Term Weight Change in College Freshmen. Alcoholism, clinical and experimental research, 43(5), 1016–1026. https://doi.org/10.1111/acer.14025, which has been published in final form at https://doi.org/10.1111/acer.14025. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: The transition to college is a developmentally sensitive time in which freshmen are at high-risk for engaging in heavy drinking and experiencing changes in weight and body composition. The study tested prospective associations among drinking patterns (weekly drinks, heavy drinking occasions/month) and alcohol calorie intake on weight and waist circumference change over the first year of college. Methods: College freshmen (N=103) were randomly selected from a pool of eligible students to participate at the beginning of the academic year. The sample was comprised of 52% males, 46% of individuals identifying as racial or ethnic minority, and 45% students with at-risk drinking as defined by the Alcohol Use Disorders Identification Test- Consumption questions. Students engaging in daily risky drinking (n=2) were excluded. Participants attended three visits during the academic year during which they provided weight and waist circumference measurements and completed assessments about drinking, dietary intake, and physical activity. Results: Weight gain (>2.3 kg) occurred in 28% of participants. In linear mixed models, drinking patterns and alcohol calorie intake were not associated with weight or waist circumference changes within individuals, when controlling for demographic and energy balance variables. Drinking patterns and alcohol calorie intake did not account for differences in anthropometric measurements between participants, when controlling for covariates. Conclusions: Alcohol use did not explain the anthropometric changes observed in a sample well represented by freshmen engaging in risky drinking (and excluding those with daily risky drinking) during the academic year. Drinking may not contribute to short-term weight gain among freshmen.NIH F32 AA024669–01A

    Women’s Perspectives on Human Security: Violence, Environment, and Sustainability

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    Violent conflict, climate change, and poverty present distinct threats to women worldwide. Importantly, women are leading the way creating and sharing sustainable solutions. Women’s security is a valuable analytical tool as well as a political agenda insofar as it addresses the specific problems affecting women’s ability to live dignified, free, and secure lives. First, this collection focuses on how conflict impacts women’s lives and well-being, including rape and gendered constructions of ethnicity, race, and religion. The book’s second section looks beyond the scope of large-scale violence to examine human security in terms of environmental policy, food, water, health, and economics. Multidisciplinary in scope, these essays from new and established contributors draw from gender studies, international relations, criminology, political science, economics, sociology, biological and ecological sciences, and planning.https://ohioopen.library.ohio.edu/oupress/1012/thumbnail.jp

    Delay discounting and substance use treatment outcomes: A systematic review focused on treatment outcomes and discounting methodology

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    Introduction Delay discounting—the tendency to choose small, immediate rewards over larger, delayed rewards—is robustly associated with substance use. Delay discounting may present challenges in treatment for substance use disorders, as individuals with elevated discounting may struggle to wait for the long-term rewards that come from abstinence, which may yield poorer treatment outcomes. However, evidence on the role of discounting in treatment outcomes has been inconsistent. The study conducted a systematic review of the literature to characterize the prospective effects of delay discounting measured pre-treatment on substance use treatment outcomes, with a focus on characterizing findings across: 1) type of treatment outcome and 2) methodology used to assess and characterize discounting. Method A systematic literature search identified N = 17 studies that examined the association between delay discounting at treatment entry (pre-treatment) and substance use treatment outcomes. Findings were reported across the following substance use treatment outcomes: abstinence, relapse, use frequency and related problems, and treatment adherence. Findings regarding discounting methodology were reported by type of discounting measure (adjusting choice task, fixed choice task, or experiential task) and parameter used to characterize discounting (k, log transformed k (lnk), and area under the curve). Results Delay discounting at treatment entry was not consistently associated with substance use treatment outcomes when examined across all studies overall (47 %) or by treatment outcome (0–40 % for most outcomes). The majority of studies (64 %) that used an adjusting choice, computer-based task reported a significant association between discounting and treatment outcomes, whereas few studies that used a fixed choice or experiential task reported significant associations with treatment outcomes (0–25 %). Most studies (71 %) that used the lnk parameter to characterize discounting reported significant associations between discounting and a range of treatment outcomes. In contrast, few studies that used k or AUC (25–33 %) reported significant associations between discounting and treatment outcomes. Conclusion When examined overall and by treatment outcome, evidence did not consistently indicate that delay discounting was prospectively associated with substance use treatment outcomes. However, delay discounting at treatment entry was more commonly associated with a variety of poorer treatment outcomes when researchers used more fine-grained methods to characterize discounting

    Population Stratification of a Common APOBEC Gene Deletion Polymorphism

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    The APOBEC3 gene family plays a role in innate cellular immunity inhibiting retroviral infection, hepatitis B virus propagation, and the retrotransposition of endogenous elements. We present a detailed sequence and population genetic analysis of a 29.5-kb common human deletion polymorphism that removes the APOBEC3B gene. We developed a PCR-based genotyping assay, characterized 1,277 human diversity samples, and found that the frequency of the deletion allele varies significantly among major continental groups (global F (ST) = 0.2843). The deletion is rare in Africans and Europeans (frequency of 0.9% and 6%), more common in East Asians and Amerindians (36.9% and 57.7%), and almost fixed in Oceanic populations (92.9%). Despite a worldwide frequency of 22.5%, analysis of data from the International HapMap Project reveals that no single existing tag single nucleotide polymorphism may serve as a surrogate for the deletion variant, emphasizing that without careful analysis its phenotypic impact may be overlooked in association studies. Application of haplotype-based tests for selection revealed potential pitfalls in the direct application of existing methods to the analysis of genomic structural variation. These data emphasize the importance of directly genotyping structural variation in association studies and of accurately resolving variant breakpoints before proceeding with more detailed population-genetic analysis

    Elastomeric Osteoconductive Synthetic Scaffolds with Acquired Osteoinductivity Expedite the Repair of Critical Femoral Defects in Rats

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    Regenerative medicine aspires to reduce reliance on or overcome limitations associated with donor tissue-mediated repair. Structural bone allografts are commonly used in orthopedic surgery, with a high percentage of graft failure due to poor tissue integration. This problem is aggravated among elderly, those suffering from metabolic conditions, or those undergoing cancer therapies that compromise graft healing. Toward this end, we developed a synthetic graft named FlexBone, in which nanocrystalline hydroxyapatite (50-wt%) was structurally integrated with crosslinked poly(hydroxyethyl methacrylate) hydrogel, which provides dimensional stability and elasticity. It recapitulates the essential role of nanocrystalline hydroxyapatite in defining the osteoconductivity and biochemical microenvironment of bone because of its affinity for biomolecules. Here, we demonstrate that FlexBone effectively absorbed endogenously secreted signaling molecules associated with the inflammation/graft healing cascade upon being press-fit into a 5-mm rat femoral segmental defect. Further, when preabsorbed with a single dose of 400-ng recombinant human (rh) bone morphogenetic protein-2/7 heterodimer, it enabled the functional repair of the critical-sized defect by 8-12 weeks. FlexBone was stably encapsulated by the bridging bony callus and the FlexBone-callus interface was continuously remodeled. In summary, FlexBone combines the dimensional stability and osteoconductivity of structural bone allografts with desirable surgical compressibility and acquired osteoinductivity in an easy-to-fabricate and scalable synthetic biomaterial.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90480/1/ten-2Etea-2E2010-2E0274.pd

    A single center phase II study of ixazomib in patients with relapsed or refractory cutaneous or peripheral T‐cell lymphomas

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    The transcription factor GATA‐3, highly expressed in many cutaneous T‐cell lymphoma (CTCL) and peripheral T‐cell lymphomas (PTCL), confers resistance to chemotherapy in a cell‐autonomous manner. As GATA‐3 is transcriptionally regulated by NF‐κB, we sought to determine the extent to which proteasomal inhibition impairs NF‐κB activation and GATA‐3 expression and cell viability in malignant T cells. Proteasome inhibition, NF‐κB activity, GATA‐3 expression, and cell viability were examined in patient‐derived cell lines and primary T‐cell lymphoma specimens ex vivo treated with the oral proteasome inhibitor ixazomib. Significant reductions in cell viability, NF‐κB activation, and GATA‐3 expression were observed preclinically in ixazomib‐treated cells. Therefore, an investigator‐initiated, single‐center, phase II study with this agent in patients with relapsed/refractory CTCL/PTCL was conducted. Concordant with our preclinical observations, a significant reduction in NF‐κB activation and GATA‐3 expression was observed in an exceptional responder following one month of treatment with ixazomib. While ixazomib had limited activity in this small and heterogeneous cohort of patients, inhibition of the NF‐κB/GATA‐3 axis in a single exceptional responder suggests that ixazomib may have utility in appropriately selected patients or in combination with other agents.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139920/1/ajh24895.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139920/2/ajh24895_am.pd
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