2,179 research outputs found
What is the excess risk of infertility in women after genital chlamydia infection? A systematic review of the evidence
Methods: Twelve databases were searched, limited to peer-reviewed literature published from January 1970 to September 2007. Conference abstracts and reference lists from reviews published since 2000 and from key articles were hand-searched. Studies were selected for review if they met the following criteria: (1) the study population comprised women of child-bearing age (defined as 15â45 years) and incorporated a comparison group of women documented as "chlamydia negative"; (2) the study outcomes included either infertility or successful pregnancy; and (3) the study design was one of the following: cohort, randomised controlled trial, "before and after" study, screening trial and systematic review. Studies were excluded if they described genital infections that either did not include Chlamydia trachomatis or described genital chlamydial co-infection, in which no data were available for C trachomatis infection alone.
Results: 3349 studies were identified by the search. One study satisfied the inclusion criteria, a longitudinal investigation measuring pregnancy rates in adolescent women with and without current chlamydial infection at baseline. That study reported no significant difference in subsequent pregnancy rates; however, it had serious methodological limitations, which restricted its conclusions.
Conclusions: This systematic review demonstrates the absence of valid evidence on the attributable risk of post-infective tubal factor infertility after genital chlamydial infection. The findings contribute empirical data to the growing debate surrounding previous assumptions about the natural history of chlamydial infection in women
A measure of conductivity for lattice fermions at finite density
We study the linear response to an external electric field of a system of
fermions in a lattice at zero temperature. This allows to measure numerically
the Euclidean conductivity which turns out to be compatible with an analytical
calculation for free fermions. The numerical method is generalizable to systems
with dynamical interactions where no analytical approach is possible.Comment: version to be published in Physics Letters
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Collaborative Roving Reference: Solving Citation Frustration One Student at a Time
Some Applications of the Extended Bendixson-Dulac Theorem
During the last years the authors have studied the number of limit cycles of
several families of planar vector fields. The common tool has been the use of
an extended version of the celebrated Bendixson-Dulac Theorem. The aim of this
work is to present an unified approach of some of these results, together with
their corresponding proofs. We also provide several applications.Comment: 19 pages, 3 figure
Building Community Through Festival: Library Orientation on the Quad
Each fall, the Libraries at the College of the Holy Cross host a library orientation festival, âLibFest,â to introduce first-year students to our services. To enhance the festival atmosphere, LibFest is hosted outside with a variety of giveaways and entertainment, including a local food truck. The event provides opportunities for students to informally meet and chat with library staff, while simultaneously learning about our services. Over time, LibFest has grown into a substantial event located in the heart of the campus, encompassing all library departments and branches as well as offices with which we frequently partner. Through yearly evaluations, we have been able to tweak and improve each yearâs festival, with significantly-increased attendance over time. We are pleased with the positive results weâve seen overall, as well as the significant strides we have made in emphasizing the Librariesâ presence on campus
Modelling the emergence of whisker barrels
Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We show in simulation how realistic whisker maps can self-organize, by assuming that information is exchanged between adjacent cells only, under the guidance of gene expression gradients. The resulting model provides a simple account of how patterns of gene expression can constrain spontaneous pattern formation to faithfully reproduce functional maps in subsequent brain structures
The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: A case crossover analysis
Background: This study examined the association between unusually high temperature and daily mortality (1997-2007) and hospital admissions (1997-2010) in the Sydney Greater Metropolitan Region (GMR) to assist in the development of targeted health program
Pulmonary Hydatid Cyst with Complicating Aspergillus Infection Presenting as a Refractory Lung Abscess
Background Hydatid disease is rare in the United States. Rarely the hydatid cyst can become infected with mycotic organisms, such as Aspergillus . We describe a young male who presents with clinical features of suppurative lung abscess whose workup diagnosed hydatid cyst complicated by Aspergillus co-infection. Case presentation A 27-year-old Peruvian male was hospitalized because of fever, chills, and productive cough of three monthsâ duration. Clinical features were consistent with a suppurative lung abscess. Significant findings included leukocytosis with eosinophilia and a chest x-ray showing a large lingular lobe thick walled cavity with a wavy irregular fluid level. The patient ultimately underwent surgical resection of the lingular lobe. Examination of the surgical specimen revealed the cavity to be a hydatid cyst. Histologic examination of the cyst wall showed intense inflammation and several septate hyphae of Aspergillus species. The patient recovered fully and has remained in good health. Conclusion A thick-walled cavity and a wavy meniscus constitute unusual features for an ordinary pyogenic lung abscess and suggests other possibilities. Endogenous cases of hydatid disease are uncommon in the United States, with the majority of cases occurring in immigrants. There are few published case reports describing incidental findings of Aspergillus in a hydatid cyst. The rare occurrence of such a condition can lead to a delay in diagnosis and treatment
Extensions of the matrix Gelfand-Dickey hierarchy from generalized Drinfeld-Sokolov reduction
The matrix version of the -KdV hierarchy has been recently
treated as the reduced system arising in a Drinfeld-Sokolov type Hamiltonian
symmetry reduction applied to a Poisson submanifold in the dual of the Lie
algebra . Here a
series of extensions of this matrix Gelfand-Dickey system is derived by means
of a generalized Drinfeld-Sokolov reduction defined for the Lie algebra
using the natural
embedding for any positive integer. The
hierarchies obtained admit a description in terms of a matrix
pseudo-differential operator comprising an -KdV type positive part and a
non-trivial negative part. This system has been investigated previously in the
case as a constrained KP system. In this paper the previous results are
considerably extended and a systematic study is presented on the basis of the
Drinfeld-Sokolov approach that has the advantage that it leads to local Poisson
brackets and makes clear the conformal (-algebra) structures related to
the KdV type hierarchies. Discrete reductions and modified versions of the
extended -KdV hierarchies are also discussed.Comment: 60 pages, plain TE
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