4,322 research outputs found

    The association between hysterectomy and ovarian cancer risk: A population-based record-linkage study

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    Background: Recent studies have called into question the long-held belief that hysterectomy without oophorectomy protects against ovarian cancer. This population-based longitudinal record-linkage study aimed to explore this relationship, overall and by age at hysterectomy, time period, surgery type, and indication for hysterectomy. Methods: We followed the female adult Western Australian population (837 942 women) across a 27-year period using linked electoral, hospital, births, deaths, and cancer records. Surgery dates were determined from hospital records, and ovarian cancer diagnoses (n¼1640) were ascertained from cancer registry records.We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between hysterectomy and ovarian cancer incidence. Results: Hysterectomy without oophorectomy (n¼78 594) was not associated with risk of invasive ovarian cancer overall (HR ¼ 0.98, 95% CI ¼ 0.85 to 1.11) or with the most common serous subtype (HR ¼ 1.05, 95% CI ¼ 0.89 to 1.23). Estimates did not vary statistically significantly by age at procedure, time period, or surgical approach. However, among women with endometriosis (5.8%) or with fibroids (5.7%), hysterectomy was associated with substantially decreased ovarian cancer risk overall (HR ¼ 0.17, 95% CI ¼ 0.12 to 0.24, and HR ¼ 0.27, 95% CI ¼ 0.20 to 0.36, respectively) and across all subtypes. Conclusions: Our results suggest that for most women, having a hysterectomy with ovarian conservation is not likely to substantially alter their risk of developing ovarian cancer. However, our results, if confirmed, suggest that ovarian cancer risk reduction could be considered as a possible benefit of hysterectomy when making decisions about surgical management of endometriosis or fibroids

    Biogenesis of a Bacterial Organelle: The Carboxysome Assembly Pathway

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    SummaryThe carboxysome is a protein-based organelle for carbon fixation in cyanobacteria, keystone organisms in the global carbon cycle. It is composed of thousands of subunits including hexameric and pentameric proteins that form a shell to encapsulate the enzymes ribulose 1,5-bisphosphate carboxylase/oxygenase and carbonic anhydrase. Here, we describe the stages of carboxysome assembly and the requisite gene products necessary for progression through each. Our results demonstrate that, unlike membrane-bound organelles of eukaryotes, in carboxysomes the interior of the compartment forms first, at a distinct site within the cell. Subsequently, shell proteins encapsulate this procarboxysome, inducing budding and distribution of functional organelles within the cell. We propose that the principles of carboxysome assembly that we have uncovered extend to diverse bacterial microcompartments

    Movement and Countermovement Dynamics Between the Religious Right and LGB Community Arising from Colorado’s Amendment 2

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    This sample of the case study of Equality Colorado will demonstrate how counter movements and litigation may limit and change how an organization surrounding a social movement acts. Colorado for Family Values helped pass Colorado’s Amendment 2 in 1992, which limited any present and future anti-discrimination legislation that would protect sexuality as a class. This ballot initiative passed by 53% of Colorado voters, and other states like Idaho and Oregon attempted to replicate this type of initiative. Amendment 2 challenged the LGB community and compelled the movement to collectively respond to the religious right with coalitions, pooled resources, and litigation. Equality Colorado, established in 1992, will exemplify how a social movement could respond to prejudicial legislation. One of Equality Colorado’s primary tactics was to reframe religion as inclusive of gay rights. It did not cede religion entirely to its opponents and attempted to delegitimize them by labeling them “radical right” as opposed to the more popular term “religious right” or “Christian Conservatives”. Additionally, Equality Colorado tried to compensate for the downsides of litigation by “translating” the legal terms to the general public and connecting litigators with the broader movement

    Site-Based Transdisciplinary Educational Partnerships: Development, Implementation, and Outcomes of a Collaborative Professional Preparation Program

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    In this article, we describe the conceptual framework, development, implementation, and outcomes of an experimental professional preparation program. University students from preparation programs in general education, educational administration, school psychology, and special education formed transdisciplinary cohorts that were placed in school settings to complete a variety of activities designed to foster greater collaboration among disciplines in serving children and youth at risk. We describe what was learned throughout the project as well as its operational structure, outcomes, and future directions for transdisciplinary professional development

    Radiometer offsets and count conversion coefficients for the Earth Radiation Budget Experiment (ERBE) spacecraft for the years 1984, 1985, and 1986

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    A compendium is presented of the ground and inflight scanner and nonscanner offsets and count conversion (gain) coefficients used for the Earth Radiation Budget Experiment (ERBE) production processing of data from the ERBS, NOAA-9, and NOAA-10 satellites for the 1 Nov. 1984 to 31 Dec. 1986

    Early Holocene Occupation at the West Lost River Site, Klamath County, Oregon

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    Excavations at the West Lost River Site (35KL972) provide new insights on early Holocene occupation of southwestern Oregon. The article focuses on the artifacts and specimens recovered from the site

    Effects of Occupational Ultrasonic Noise Exposure on Hearing of Dental Hygienists: A Pilot Study

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    Purpose. The purpose of this case-control study was to determine whether long-term ultrasonic noise exposure via the dental office environment is related to dental hygienists\u27 hearing status. Methods. Registered dental hygienists (N - 698) who live in the Hampon Roads areas of Virginia were mailed a Dental Hygiene Word History Questionnaire to determine who would meet the inclusion criteria and would be willing to participate in the study. Consenting subjects were categorized into one of two groups, according to ultrasonic sealer usage rate, and matched on age. Persons with known hearing loss due to infection, disease, or congenital defect were excluded from the study. The final sample consisted of 20 dental hygienists with a high ultrasonic usage rate and a matched group of 20 dental hygienists who had a low ultrasonic usage rate. Once the groups were formed, a certified audiologist tested subjects\u27 hearing in each ear via the pure-tone audiometer. Audiometric data were analyzed using the analysis of variance for repeated measures procedure to determine if degree of ultrasonic sealer noise exposure in the dental office environment was significantly related to hearing status in these dental hygienists. Results. Results revealed that the right and left ears were not statistically different in the hearing threshold levels, regardless of group status. However, there was a significant difference in the high ultrasonic usage group and the low ultrasonic usage group at the 3000 Hz. No differences were found at the frequencies of 500, 1000, 2000, 4000, 6000, and 8000 Hz. Conclusions. Based on these outcomes, the ultrasonic sealer is not considered to have a negative effect on the hearing of dental hygienists at 500,1000, 2000, 4000, 6000, and 8000 Hz, but may be related to hearing loss at 3000 Hz. Ultrasonic noise may in fact be affecting dental hygienists\u27 hearing at 3000 Hz, but loss of hearing observed at the higher frequencies may be attributed to other unidentified factors present in both groups

    Behaviour of harbour seal (Phoca vitulina vitulina) mother-pup pairs in Irish Sea intertidal habitats

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    Information is sparse on harbour seal pupping dates and mother-pup behavioural ecology in Ireland. Here we define the pupping season and quantify the behaviour of mother-pup pairs in intertidal habitats of Dundrum Bay, north-east Ireland. Seals were counted and video footage was taken of mother-pup pairs at a rocky ledge site and a sandy beach site between 2002 and 2015. We recorded distances between pups and their mothers, filial social interactions, pup resting behaviours and mother scanning at three intertidal zones: the water, water’s edge and dry ledge or beach. The peak pupping time was 04–15 July at both sites, but the pup-to-adult ratio was higher at the rocky ledge site. Pups almost always remained less than 1m away from their mothers, and were closest while mother and pup rested in the dry zone. Filial social interactions were most frequent in the water, least frequent in the dry zone and intermediate at the water’s edge; suckling occurred almost exclusively at the water’s edge. Our findings highlight the essential features of a harbour seal pup’s social and physical environment. We suggest how these features could be incorporated into the design and procedures of rehabilitation centres for ‘orphan’ pups
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