6,098 research outputs found

    Temporal Changes in Genetic Variation of Boll Weevil (Coleoptera: Curculionidae) Populations, and Implications for Population Assignment in Eradication Zones

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    An existing microsatellite genotype database has been used for several years in population genetic assignment analyses of boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), captured in eradication zones. It is important to update it in case of changes in genotype frequency at any of the locations over time. Such changes at neutral loci could be caused by drift, immigration, or population bottlenecks. We examined allele frequency distribution for 10 microsatellite loci to determine genetic differentiation among 10 boll weevil populations sampled from Texas and Mexico in 2009. In addition, temporal changes in genetic composition were examined in the eight populations for which samples were available from previous years. Substantial levels of spatial genetic structure were observed, with the 10 populations clustering as four major groups. Pairwise FST estimates in 2009 samples ranged from 0.001 (College Station-Cameron) to 0.492 (College Station-Ojinaga). There was little change in genetic profiles over time at four of the eight locations. Thus, for those four locations, genotype and allele frequency data can be pooled over the two sample dates, which will provide greater statistical power in future population assignment tests. However, genetic profiles changed substantially at Ojinaga, and to a lesser extent at Uvalde, Cameron, and Rosales, so the 2009 genotype data should be substituted in future analyses. Finally, populations from two new locations, Brownsville and Lockhart, TX, were sampled, genotyped, and added to the database. The addition of Lockhart is particularly important given its surprisingly high differentiation from the relatively nearby populations of Cameron and Uvalde

    Ethno-national ties and international business opportunity exploitation: The role of environmental factors

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    This paper examines the effect of ethnic populations on international opportunity exploitation at a societal, or national, level. Past research shows a relationship between ethnic ties and international opportunity at an individual level; however, little is known about the role of ethnic ties and international opportunity at a national level, which is called ‘ethno-national ties’ in this study. In order to acquire in-depth knowledge of this subject, we studied a population of Chinese who are living outside their home country and applied contingency theory principles to investigate environmental boundary conditions that affect this population. Data collected from Chinese exporters indicate an overall positive effect of ethno-national ties on international opportunity exploitation—an effect that is influenced by three moderating variables: technological turbulence, psychic distance, and export barriers. Technological turbulence and export barriers weaken the effect of ethno-national ties on international opportunity exploitation while psychic distance enhances the effect

    Willingness to Pay for a Highland Agricultural Restriction Policy to Improve Water Quality in South Korea: Correcting Anomalous Preference in Contingent Valuation Method

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    This study examines the willingness to pay (WTP) for the highland agriculture restriction policy which aims to stabilize the water quality in the Han River basin, South Korea. To estimate the WTP, we use a double-bounded contingent valuation method and a random-effects interval-data regression. We extend contingent valuation studies by dealing with the potential preference anomalies (shift, anchoring, and inconsistent response effects). The result indicates that after the preference anomalies are corrected, the statistical precision of parameter estimates is improved. After correcting the potential preference anomalies, estimated welfare gains are on average South Korean currency (KRW) 2,861 per month per household. Based on the WTP estimate, the total benefits from the land use restriction policy are around KRW 297.73 billion and the total costs are around KRW 129.44 billion. The net benefit is, thus, around KRW 168.29 billion. This study suggests several practical solutions that would be useful for the water management. First, a priority should be given to the valid compensation for the highland farmers’ expected income loss. Second, it is necessary to increase in the unit cost of the highland purchase. Third, wasted or inefficiently used costs (e.g., overinvestment in waste treatment facilities, and temporary upstream community support) should be transferred to the program associated with high mountainous agriculture field purchase. Results of our analysis support South Korean legislators and land use policy makers with useful information for the approval and operationalization of the policy.DFG/GRK 1565/1University of BayreuthNational Research Foundation of Kore

    BCL-W has a fundamental role in B cell survival and lymphomagenesis.

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    Compromised apoptotic signaling is a prerequisite for tumorigenesis. The design of effective therapies for cancer treatment depends on a comprehensive understanding of the mechanisms that govern cell survival. The antiapoptotic proteins of the BCL-2 family are key regulators of cell survival and are frequently overexpressed in malignancies, leading to increased cancer cell survival. Unlike BCL-2 and BCL-XL, the closest antiapoptotic relative BCL-W is required for spermatogenesis, but was considered dispensable for all other cell types. Here, however, we have exposed a critical role for BCL-W in B cell survival and lymphomagenesis. Loss of Bcl-w conferred sensitivity to growth factor deprivation-induced B cell apoptosis. Moreover, Bcl-w loss profoundly delayed MYC-mediated B cell lymphoma development due to increased MYC-induced B cell apoptosis. We also determined that MYC regulates BCL-W expression through its transcriptional regulation of specific miR. BCL-W expression was highly selected for in patient samples of Burkitt lymphoma (BL), with 88.5% expressing BCL-W. BCL-W knockdown in BL cell lines induced apoptosis, and its overexpression conferred resistance to BCL-2 family-targeting BH3 mimetics. Additionally, BCL-W was overexpressed in diffuse large B cell lymphoma and correlated with decreased patient survival. Collectively, our results reveal that BCL-W profoundly contributes to B cell lymphoma, and its expression could serve as a biomarker for diagnosis and aid in the development of better targeted therapies

    Economic valuation of the aquatic biodiversity conservation in South Korea: Correcting for the endogeneity bias in contingent valuation

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    In this study, we use the Contingent Valuation (CV) method to estimate households' willingness to pay (WTP) for the aquatic ecosystem health (biodiversity) improvement. This paper extends CV studies by dealing with the endogenous effect of a proxy variable, namely the subjective experience of negative environmental quality changes. The results show that the correction for the endogeneity bias facilitates the efficiency of parameter estimation in the empirical model. The mean WTP per household accounts for around 46.8% (KRW 79.6) of the current water use charge (KRW 170 per cubic meter). The total benefit from conserving the biodiversity is around KRW 198.62 billion. We found several factors that affect households' WTP for fish biodiversity conservation, suggesting the importance of these factors in the formulation of water policies associated with aquatic biodiversity. In addition, the inefficient water management costs should be redistributed to other projects or new programs such as for the fish biodiversity conservation. © 2017 by the authors.DFG/GRK/1565/

    Mid-JJ CO Line Observations of Protostellar Outflows in the Orion Molecular Clouds

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    Ten protostellar outflows in the Orion molecular clouds were mapped in the 12^{12}CO/13^{13}CO J=65{J=6\rightarrow5} and 12^{12}CO J=76{J=7\rightarrow6} lines. The maps of these mid-JJ CO lines have an angular resolution of about 10'' and a typical field size of about 100''. Physical parameters of the molecular outflows were derived, including mass transfer rates, kinetic luminosities, and outflow forces. The outflow sample was expanded by re-analyzing archival data of nearby low-luminosity protostars, to cover a wide range of bolometric luminosities. Outflow parameters derived from other transitions of CO were compared. The mid-JJ (Jup6J_{\rm up} \approx 6) and low-JJ (Jup3J_{\rm up} \leq 3) CO line wings trace essentially the same outflow component. By contrast, the high-JJ (up to Jup50J_{\rm up} \approx 50) line-emission luminosity of CO shows little correlation with the kinetic luminosity from the J=65{J=6\rightarrow5} line, which suggests that they trace distinct components. The low/mid-JJ CO line wings trace long-term outflow behaviors while the high-JJ CO lines are sensitive to short-term activities. The correlations between the outflow parameters and protostellar properties are presented, which shows that the strengths of molecular outflows increase with bolometric luminosity and envelope mass.Comment: 31 pages, 16 figures, Accepted for publication in ApJ

    Amplify-and-Forward Distributed Beamforming with Local CSI in the Presence of Interferences

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    This paper introduces an optimum amplify-and-forward (AF) distributed beamforming (DBF) in the presence of cochannel interference (CCI) when only local channel-state information (CSI) is available at each relay. It is shown that the proposed DBF closely achieves the performance obtained with global CSI when interference power toward relays is small or there are a large number of interferers but greatly reduces the complexity and overhead. The proposed DBF provides significant improvements over the conventional DBF designed without considering CCI at the cost of slightly increased complexity and overhead and achieves the capacity scaling of 1/2log⁡K through K relays, where 1/2log⁡K corresponds to the maximal capacity scaling when there is no CCI

    Spontaneous Tonsillar Hemorrhage and Post-Tonsillectomy Hemorrhage

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    Spontaneous tonsillar hemorrhage from infectious causes is extremely rare and post-tonsillectomy hemorrhage, although also relatively rare, is an unavoidable complication of the procedure. Hemorrhage in association with tonsillitis or tonsillectomy is potentially dangerous and can be life threatening. We report here the presentation and management of a 42-yr-old man with severe spontaneous hemorrhage from infected tonsils and post-tonsillectomy hemorrhage. We suggest that if attempts to control the bleeding are not successful or if severe spontaneous tonsillar hemorrhage occurs repeatedly or a malignancy is suspected, tonsillectomy and close postoperative follow up is recommended
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