2,500 research outputs found
Herpes Simplex Virus Type 2 Seroprevalence and Ultrasound-Diagnosed Uterine Fibroids in a Large Population of Young African-American Women
For decades reproductive tract infections (RTIs) have been hypothesized to play a role in uterine fibroid development. The few previous studies conducted used self-reported history of RTIs and had inconsistent findings. We investigated this hypothesis further using serological analysis, an immunological measure of past exposure. We focused on herpes simplex virus type 2 (HSV-2) because prior published data have suggested a possible association with fibroids, and serology for HSV-2 is much more sensitive than self-report. We used cross-sectional enrollment data from African-American women enrolled in a prospective study of fibroid incidence and growth (recruited 2010–2012) in the Detroit, Michigan, area. The women were aged 23–34 years and were screened for fibroids using a standardized ultrasound examination at their enrollment. Age- and multivariable-adjusted logistic regression models were used to estimate odds ratios. Of 1,696 participants, 1,658 had blood samples and HSV-2 serology results; 22% of participants with serology results had fibroids. There was no significant association between HSV-2 seropositivity and the presence of fibroids (multivariable-adjusted odds ratio = 0.94, 95% confidence interval: 0.73, 1.20), nor were there any associations with size of the largest fibroid, number of fibroids, or total fibroid volume. Our data provide no evidence for an influence of HSV-2 exposure on fibroid risk in young African-American women. Further study of other serologically measured RTIs is warranted
Towards the “ultimate earthquake-proof” building: Development of an integrated low-damage system
The 2010–2011 Canterbury earthquake sequence has highlighted the
severe mismatch between societal expectations over the reality of seismic performance
of modern buildings. A paradigm shift in performance-based design criteria
and objectives towards damage-control or low-damage design philosophy and
technologies is urgently required. The increased awareness by the general public,
tenants, building owners, territorial authorities as well as (re)insurers, of the severe
socio-economic impacts of moderate-strong earthquakes in terms of damage/dollars/
downtime, has indeed stimulated and facilitated the wider acceptance and
implementation of cost-efficient damage-control (or low-damage) technologies.
The ‘bar’ has been raised significantly with the request to fast-track the development
of what the wider general public would hope, and somehow expect, to live
in, i.e. an “earthquake-proof” building system, capable of sustaining the shaking of
a severe earthquake basically unscathed.
The paper provides an overview of recent advances through extensive research,
carried out at the University of Canterbury in the past decade towards the development
of a low-damage building system as a whole, within an integrated
performance-based framework, including the skeleton of the superstructure, the
non-structural components and the interaction with the soil/foundation system.
Examples of real on site-applications of such technology in New Zealand, using
concrete, timber (engineered wood), steel or a combination of these materials, and
featuring some of the latest innovative technical solutions developed in the laboratory
are presented as examples of successful transfer of performance-based seismic
design approach and advanced technology from theory to practice
Flexibility within the middle ears of vertebrates
Introduction and aims: Tympanic middle ears have evolved multiple times independently among vertebrates, and share common features. We review flexibility within tympanic middle ears and consider its physiological and clinical implications.
Comparative anatomy: The chain of conducting elements is flexible: even the ‘single ossicle’ ears of most non-mammalian tetrapods are functionally ‘double ossicle’ ears due to mobile articulations between the stapes and extrastapes; there may also be bending within individual elements.
Simple models: Simple models suggest that flexibility will generally reduce the transmission of sound energy through the middle ear, although in certain theoretical situations flexibility within or between conducting elements might improve transmission. The most obvious role of middle-ear flexibility is to protect the inner ear from high-amplitude displacements.
Clinical implications: Inter-ossicular joint dysfunction is associated with a number of pathologies in humans. We examine attempts to improve prosthesis design by incorporating flexible components
Damage function for historic paper. Part I: Fitness for use
Background In heritage science literature and in preventive conservation practice, damage functions are used to model material behaviour and specifically damage (unacceptable change), as a result of the presence of a stressor over time. For such functions to be of use in the context of collection management, it is important to define a range of parameters, such as who the stakeholders are (e.g. the public, curators, researchers), the mode of use (e.g. display, storage, manual handling), the long-term planning horizon (i.e. when in the future it is deemed acceptable for an item to become damaged or unfit for use), and what the threshold of damage is, i.e. extent of physical change assessed as damage. Results In this paper, we explore the threshold of fitness for use for archival and library paper documents used for display or reading in the context of access in reading rooms by the general public. Change is considered in the context of discolouration and mechanical deterioration such as tears and missing pieces: forms of physical deterioration that accumulate with time in libraries and archives. We also explore whether the threshold fitness for use is defined differently for objects perceived to be of different value, and for different modes of use. The data were collected in a series of fitness-for-use workshops carried out with readers/visitors in heritage institutions using principles of Design of Experiments. Conclusions The results show that when no particular value is pre-assigned to an archival or library document, missing pieces influenced readers/visitors’ subjective judgements of fitness-for-use to a greater extent than did discolouration and tears (which had little or no influence). This finding was most apparent in the display context in comparison to the reading room context. The finding also best applied when readers/visitors were not given a value scenario (in comparison to when they were asked to think about the document having personal or historic value). It can be estimated that, in general, items become unfit when text is evidently missing. However, if the visitor/reader is prompted to think of a document in terms of its historic value, then change in a document has little impact on fitness for use
Standardizing estimates of the Plasmodium falciparum parasite rate
<p>Abstract</p> <p>Background</p> <p>The <it>Plasmodium falciparum </it>parasite rate (PfPR) is a commonly reported index of malaria transmission intensity. PfPR rises after birth to a plateau before declining in older children and adults. Studies of populations with different age ranges generally report average PfPR, so age is an important source of heterogeneity in reported PfPR data. This confounds simple comparisons of PfPR surveys conducted at different times or places.</p> <p>Methods</p> <p>Several algorithms for standardizing PfPR were developed using 21 studies that stratify in detail PfPR by age. An additional 121 studies were found that recorded PfPR from the same population over at least two different age ranges; these paired estimates were used to evaluate these algorithms. The best algorithm was judged to be the one that described most of the variance when converting the PfPR pairs from one age-range to another.</p> <p>Results</p> <p>The analysis suggests that the relationship between PfPR and age is predictable across the observed range of malaria endemicity. PfPR reaches a peak after about two years and remains fairly constant in older children until age ten before declining throughout adolescence and adulthood. The PfPR pairs were poorly correlated; using one to predict the other would explain only 5% of the total variance. By contrast, the PfPR predicted by the best algorithm explained 72% of the variance.</p> <p>Conclusion</p> <p>The PfPR in older children is useful for standardization because it has good biological, epidemiological and statistical properties. It is also historically consistent with the classical categories of hypoendemic, mesoendemic and hyperendemic malaria. This algorithm provides a reliable method for standardizing PfPR for the purposes of comparing studies and mapping malaria endemicity. The scripts for doing so are freely available to all.</p
A Search for Isolated Microwave Pulses from the Perseus Cluster of Galaxies
The paper describes a search for prompt
microwave emissions from supernovae in the central
region of the Perseus cluster of galaxies, using a
coincidence technique involving five tracking radiometers
located at widely spaced sites. No coincidences
were found between January and December, 1973, and no supernovae were reported during this period
from the optical surveys, in that region of sky
Cervical neoplasia–related factors and decreased prevalence of uterine fibroids among a cohort of African American women
To investigate whether the previously reported inverse association between cervical neoplasia and uterine fibroids is corroborated
Self-Reported Reproductive Tract Infections and Ultrasound Diagnosed Uterine Fibroids in African-American Women
Background: For decades, it has been hypothesized that reproductive tract infections (RTIs) are risk factors for uterine fibroids. However, only two recent studies have been conducted. We aimed to investigate the relationship between RTIs and fibroids in a large study using ultrasound screening for fibroids
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