4,413 research outputs found
IL-6 controls susceptibility to helminth infection by impeding Th2 responsiveness and altering the Treg phenotype in vivo
IL-6 plays a pivotal role in favoring T-cell commitment toward a Th17 cell rather than Treg-cell phenotype, as established through in vitro model systems. We predicted that in the absence of IL-6, mice infected with the gastrointestinal helminth Heligmosomoides polygyrus would show reduced Th17-cell responses, but also enhanced Treg-cell activity and consequently greater susceptibility. Surprisingly, worm expulsion was markedly potentiated in IL-6-deficient mice, with significantly stronger adaptive Th2 responses in both IL-6−/− mice and BALB/c recipients of neutralizing anti-IL-6 monoclonal Ab. Although IL-6-deficient mice showed lower steady-state Th17-cell levels, IL-6-independent Th17-cell responses occurred during in vivo infection. We excluded the Th17 response as a factor in protection, as Ab neutralization did not modify immunity to H. polygyrus infection in BALB/c mice. Resistance did correlate with significant changes to the associated Treg-cell phenotype however, as IL-6-deficient mice displayed reduced expression of Foxp3, Helios, and GATA-3, and enhanced production of cytokines within the Treg-cell population. Administration of an anti-IL-2:IL-2 complex boosted Treg-cell proportions in vivo, reduced adaptive Th2 responses to WT levels, and fully restored susceptibility to H. polygyrus in IL-6-deficient mice. Thus, in vivo, IL-6 limits the Th2 response, modifies the Treg-cell phenotype, and promotes host susceptibility following helminth infection
A follow-up study of former students enrolled in the program administration of educational programs in schools of nursing
Thesis (M.S.)--Boston Universit
Children At-Risk For Hearing Impairment: A Retrospective Study Of The Ontario Infant Hearing Program Population
There is widespread agreement that infant hearing screening programs are effective but such programs may fail to detect all hearing impairment and children can develop subsequent hearing loss after passing the initial screen. This is the core rationale for surveillance programs that are analyzed in this thesis. Infants with hearing risk factors are followed using surveillance programs that include monitoring by audiological assessment.
The study population in this thesis consists of 2,390 children with normal hearing and 248 children with hearing impairment from different referral routes. The Infant Hearing Program Surveillance group is 1.48% of the number of hearing-impaired children. The thesis methodology identifies children with at least one risk factor and then analyzes the different referral routes and hearing loss features. It concludes that there is a need for further evaluation and improvements in surveillance programs, as well as all parts of screening and habilitation
Probing the Gravitational Wave Signature from Cosmic Phase Transitions at Different Scales
We present a new signature by which to one could potentially discriminate
between a spectrum of gravitational radiation generated by a self-ordering
scalar field vs that of inflation, specifically a comparison of the magnitude
of a flat spectrum at frequencies probed by future direct detection experiments
to the magnitude of a possible polarization signal in the Cosmic Microwave
Background (CMB) radiation. In the process we clarify several issues related to
the proper calculation of such modes, focusing on the effect of
post-horizon-crossing evolution.Comment: 4 pages, Phys. Rev D version (revised in response to referee's
comments
A Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions
Using a large N sigma model approximation we explicitly calculate the power
spectrum of gravitational waves arising from a global phase transition in the
early universe and we confirm that it is scale invariant, implying an
observation of such a spectrum may not be a unique feature of inflation.
Moreover, the predicted amplitude can be over 3 orders of magnitude larger than
the naive dimensional estimate, implying that even a transition that occurs
after inflation may dominate in Cosmic Microwave Background polarization or
other gravity wave signals.Comment: 4 pages, PRL published versio
A Letter of Consequence: Referral Letters from General Practitioners to Secondary Mental Health Services
The referral letter is a key instrument in moving patients from primary to secondary care services. Consequently, the circumstances in which a referral should be made and its contents have been the subject of clinical guidelines. This article is based on a project that demonstrated
that physicians do not adhere to clinical guidelines when referring patients to secondary mental health services. This research supports earlier findings into noncompliance
with guidelines by general practitioners (GPs). The authors briefly note possible reasons, which have been the subject of some debate. They also present a content analysis of referral letters to demonstrate the important ways in which they differ from guideline criteria. However, their central argument is that the role of the referral letter in relation to the GP’s repertoire of treatments has not been understood fully. Such understanding implies the need for a reexamination of the support available for GPs
Aharonov-Bohm Radiation
A solenoid oscillating in vacuum will pair produce charged particles due to
the Aharonov-Bohm (AB) interaction. We calculate the radiation pattern and
power emitted for charged scalar particles. We extend the solenoid analysis to
cosmic strings, and find enhanced radiation from cusps and kinks on loops. We
argue by analogy with the electromagnetic AB interaction that cosmic strings
should emit photons due to the gravitational AB interaction of fields in the
conical spacetime of a cosmic string. We calculate the emission from a kink and
find that it is of similar order as emission from a cusp, but kinks are vastly
more numerous than cusps and may provide a more interesting observational
signature.Comment: Accepted for publication in Phys Rev
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