1,766 research outputs found
USE OF CHAMBERLAIN FIXED EFFECTS APPROACH TO ESTIMATE WILLINGNESS-TO-PAY FOR LITTLE TENNESSEE RIVER BASIN MANAGEMENT ALTERNATIVES
The paper discusses an application of Chamberlain's fixed effects model to contingent valuation method survey data obtained for eight management alternatives for the Little Tennessee River basin. The advantages of using this approach versus cross-sectional logit, pooled logit, and cross-sectional logit with lags are discussed and a technique to obtain willingness-to-pay estimates from estimated coefficients is offered. Drawbacks of using Chamberlain's fixed effects model, difficulties encountered, and directions for further research are presented.Environmental Economics and Policy,
A Mutational Hotspot in the 2B Domain of Human Hair Basic Keratin 6 (hHb6) in Monilethrix Patients
Monilethrix is an inherited hair dystrophy in which affected, fragile, hairs have an unique beaded morphology. Ultrastructural studies suggest a defect in filament structure in the cortex of the hair, and the hard keratins of hair and nail are thus candidate genes. In several families with autosomal dominant monilethrix, the disorder has been linked to the type II keratin gene cluster at chromosome 12q13. Recently, causative mutations in the critical helix termination motif in the 2B domain of the human hair basic keratin 6 (hHb6) have been identified. We now report the results of sequencing this domain in 13 unrelated families or cases with monilethrix. Five of the 13 had the same mutation as previously found, a G to A transversion leading to a lysine for glutamic acid substitution (E413K) in the 2B domain (residue 117 of the 2B helix) of hHb6. The mutation was confirmed by a restriction fragment length polymorphism assay developed for this purpose, and, as this mutation is evidently a common cause of the syndrome, for use in screening other cases. In eight families or cases, however, including three in whom linkage data are consistent with a defect at the type II keratin locus, no mutation was found in this domain of hHb6
Quantitative, Architectural Analysis of Immune Cell Subsets in Tumor-Draining Lymph Nodes from Breast Cancer Patients and Healthy Lymph Nodes
Background: To date, pathological examination of specimens remains largely qualitative. Quantitative measures of tissue spatial features are generally not captured. To gain additional mechanistic and prognostic insights, a need for quantitative architectural analysis arises in studying immune cell-cancer interactions within the tumor microenvironment and tumor-draining lymph nodes (TDLNs). Methodology/Principal Findings: We present a novel, quantitative image analysis approach incorporating 1) multi-color tissue staining, 2) high-resolution, automated whole-section imaging, 3) custom image analysis software that identifies cell types and locations, and 4) spatial statistical analysis. As a proof of concept, we applied this approach to study the architectural patterns of T and B cells within tumor-draining lymph nodes from breast cancer patients versus healthy lymph nodes. We found that the spatial grouping patterns of T and B cells differed between healthy and breast cancer lymph nodes, and this could be attributed to the lack of B cell localization in the extrafollicular region of the TDLNs. Conclusions/Significance: Our integrative approach has made quantitative analysis of complex visual data possible. Our results highlight spatial alterations of immune cells within lymph nodes from breast cancer patients as an independent variable from numerical changes. This opens up new areas of investigations in research and medicine. Future application of this approach will lead to a better understanding of immune changes in the tumor microenvironment and TDLNs, and how they affect clinical outcome
Bostonia: The Boston University Alumni Magazine. Volume 9
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
Intake of specific fruits and vegetables in relation to risk of estrogen receptor-negative breast cancer among postmenopausal women. Breast Cancer Res
Abstract In previous studies of postmenopausal women, overall intake of fruits and vegetables groups has been inversely associated with estrogen receptor-negative (ER-) breast cancer. In this analysis, we prospectively examined the associations of specific fruits and vegetables with risk of ER-postmenopausal breast cancer among 75,929 women aged 38-63 years at baseline and followed for up to 24 years. Dietary data were collected seven times during this period. Cox proportional hazard models were used, adjusting for potential confounders, including a modified Alternate Mediterranean Diet score. We ascertained 792 incident cases of ER-postmenopausal breast cancer. The multivariate relative risk (RR) for every 2 servings/week consumption for total berries was 0.82 (95 % CI = 0.71-0.96, p = 0.01), and the RR for women who consumed at least one serving of blueberries a week was 0.69 (95 % CI = 0.50-0.95, p = 0.02) compared with non-consumers. Also, the RR for consuming at least 2 servings of peaches/ nectarines per week was 0.59 (95 % CI = 0.37-0.93, p = 0.02). Risk of ER-breast cancer was not associated with intakes of other specific fruits or vegetables. In conclusion, higher intake of berries and peaches was associated with lower risk of ER-breast cancer among postmenopausal women. These results are considered exploratory and need to be confirmed in further studies
Regulatory Polymorphisms in the Cyclophilin A Gene, PPIA, Accelerate Progression to AIDS
Human cyclophilin A, or CypA, encoded by the gene peptidyl prolyl isomerase A (PPIA), is incorporated into the HIV type 1 (HIV-1) virion and promotes HIV-1 infectivity by facilitating virus uncoating. We examined the effect of single nucleotide polymorphisms (SNPs) and haplotypes within the PPIA gene on HIV-1 infection and disease progression in five HIV-1 longitudinal history cohorts. Kaplan-Meier survival statistics and Cox proportional hazards model were used to assess time to AIDS outcomes. Among eight SNPs tested, two promoter SNPs (SNP3 and SNP4) in perfect linkage disequilibrium were associated with more rapid CD4+ T-cell loss (relative hazard = 3.7, p = 0.003) in African Americans. Among European Americans, these alleles were also associated with a significant trend to more rapid progression to AIDS in a multi-point categorical analysis (p = 0.005). Both SNPs showed differential nuclear protein-binding efficiencies in a gel shift assay. In addition, one SNP (SNP5) located in the 5′ UTR previously shown to be associated with higher ex vivo HIV-1 replication was found to be more frequent in HIV-1-positive individuals than in those highly exposed uninfected individuals. These results implicate regulatory PPIA polymorphisms as a component of genetic susceptibility to HIV-1 infection or disease progression, affirming the important role of PPIA in HIV-1 pathogenesis
A Review of the Scientific Rigor, Reproducibility, and Transparency Studies Conducted by the ABRF Research Groups.
Shared research resource facilities, also known as core laboratories (Cores), are responsible for generating a significant and growing portion of the research data in academic biomedical research institutions. Cores represent a central repository for institutional knowledge management, with deep expertise in the strengths and limitations of technology and its applications. They inherently support transparency and scientific reproducibility by protecting against cognitive bias in research design and data analysis, and thedy have institutional responsibility for the conduct of research (research ethics, regulatory compliance, and financial accountability) performed in their Cores. The Association of Biomolecular Resource Facilities (ABRF) is a FASEB-member scientific society whose members are scientists and administrators that manage or support Cores. The ABRF Research Groups (RGs), representing expertise for an array of cutting-edge and established technology platforms, perform multicenter research studies to determine and communicate best practices and community-based standards. This review provides a summary of the contributions of the ABRF RGs to promote scientific rigor and reproducibility in Cores from the published literature, ABRF meetings, and ABRF RGs communications
Constrained patterns of covariation and clustering of HIV-1 non-nucleoside reverse transcriptase inhibitor resistance mutations
Objectives:We characterized pairwise and higher order patterns of non-nucleoside reverse transcriptase inhibi-tor (NNRTI)-selected mutations because multiple mutations are usually required for clinically significant resist-ance to second-generation NNRTIs. Patients and methods: We analysed viruses from 13039 individuals with sequences containing at least one of 52 published NNRTI-selected mutations, including 1133 viruses from individuals who received efavirenz but no other NNRTI and 1510 viruses from individuals who received nevirapine but no other NNRTI. Of the 17 reported etravirine resistance-associated mutations (RAMs), Y181C/I/V, L100I, K101P and M230L were considered major based on published in vitro susceptibility data
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