378 research outputs found
Regional distribution of fatiguing illnesses in the United States: a pilot study
BACKGROUND: Chronic fatigue syndrome (CFS) is a debilitating illness with no known cause or effective therapy. Population-based epidemiologic data on CFS prevalence are critical to put CFS in a realistic context for public health officials and others responsible for allocating resources. METHODS: We conducted a pilot random-digit-dialing survey to estimate the prevalence of fatiguing illnesses in different geographic regions and in urban and rural populations of the United States. This report focuses on 884 of 7,317 respondents 18 to 69 years old. Fatigued (440) and randomly selected non-fatigued (444) respondents completed telephone questionnaires concerning fatigue, other symptoms, and medical history. RESULTS: We estimated 12,186 per 100,000 persons 18 to 69 years of age suffered from fatigue lasting for at least 6 months (chronic fatigue), and 1,197 per 100,000 described an illness that, though lacking clinical evaluation, met criteria for CFS (CFS-like). Chronic fatigue and CFS-like illness were more common in rural than in urban populations, although the differences were not significant. The prevalence of these fatiguing illnesses did not differ meaningfully among the four regions surveyed, and no significant geographic trends were observed. CONCLUSIONS: This investigation estimated that nearly 2.2 million American adults suffer from CFS-like illness. The study also suggested the need to focus future investigations of fatigue on populations with lower incomes and less education. There was no evidence for regional differences in the occurrence of fatiguing illnesses
Single-Scale Natural SUSY
We consider the prospects for natural SUSY models consistent with current
data. Recent constraints make the standard paradigm unnatural so we consider
what could be a minimal extension consistent with what we now know. The most
promising such scenarios extend the MSSM with new tree-level Higgs interactions
that can lift its mass to at least 125 GeV and also allow for flavor-dependent
soft terms so that the third generation squarks are lighter than current bounds
on the first and second generation squarks. We argue that a common feature of
almost all such models is the need for a new scale near 10 TeV, such as a scale
of Higgsing or confinement of a new gauge group. We consider the question
whether such a model can naturally derive from a single mass scale associated
with supersymmetry breaking. Most such models simply postulate new scales,
leaving their proximity to the scale of MSSM soft terms a mystery. This
coincidence problem may be thought of as a mild tuning, analogous to the usual
mu problem. We find that a single mass scale origin is challenging, but suggest
that a more natural origin for such a new dynamical scale is the gravitino
mass, m_{3/2}, in theories where the MSSM soft terms are a loop factor below
m_{3/2}. As an example, we build a variant of the NMSSM where the singlet S is
composite, and the strong dynamics leading to compositeness is triggered by
masses of order m_{3/2} for some fields. Our focus is the Higgs sector, but our
model is compatible with a light stop (with the other generation squarks heavy,
or with R-parity violation or another mechanism to hide them from current
searches). All the interesting low-energy mass scales, including linear terms
for S playing a key role in EWSB, arise dynamically from the single scale
m_{3/2}. However, numerical coefficients from RG effects and wavefunction
factors in an extra dimension complicate the otherwise simple story.Comment: 32 pages, 3 figures; version accepted by JHE
Compositional controls on oceanic plates : geophysical evidence from the MELT area
Author Posting. © The Authors, 2005. This is the author's version of the work. It is
posted here by permission of Nature Publishing Group for personal use, not for redistribution. The
definitive version was published in Nature 437 (2005): 249-252, doi:10.1038/nature04014.Magnetotelluric (MT) and seismic data, collected during the MELT
experiment at the Southern East Pacific Rise (SEPR) constrain the distribution
of melt beneath this mid-ocean-ridge spreading center and also the evolution of the
oceanic lithosphere during its early cooling history. In this paper, we focus on
structure imaged at distances ~100 to 350 km east of the ridge crest, corresponding
to seafloor ages of ~1.3 to 4.5 Ma, where the seismic and electrical conductivity
structure is nearly constant, independent of age. Beginning at a depth of about 60
km, there is a large increase in electrical conductivity and a change from isotropic
to transversely anisotropic electrical structure with higher conductivity in the
direction of fast propagation for seismic waves. Because conductive cooling
models predict structure that increases in depth with age, extending to about 30
km at 4.5 Ma, we infer that the structure of young oceanic plates is instead
controlled by a decrease in water content above 60 km induced by the melting
process beneath the spreading center.US participation in the MELT experiment and subsequent analysis was funded by NSF grants through the Marine Geology and Geophysics Program, Ocean Sciences Division
Asteroseismology and Interferometry
Asteroseismology provides us with a unique opportunity to improve our
understanding of stellar structure and evolution. Recent developments,
including the first systematic studies of solar-like pulsators, have boosted
the impact of this field of research within Astrophysics and have led to a
significant increase in the size of the research community. In the present
paper we start by reviewing the basic observational and theoretical properties
of classical and solar-like pulsators and present results from some of the most
recent and outstanding studies of these stars. We centre our review on those
classes of pulsators for which interferometric studies are expected to provide
a significant input. We discuss current limitations to asteroseismic studies,
including difficulties in mode identification and in the accurate determination
of global parameters of pulsating stars, and, after a brief review of those
aspects of interferometry that are most relevant in this context, anticipate
how interferometric observations may contribute to overcome these limitations.
Moreover, we present results of recent pilot studies of pulsating stars
involving both asteroseismic and interferometric constraints and look into the
future, summarizing ongoing efforts concerning the development of future
instruments and satellite missions which are expected to have an impact in this
field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume
14, Issue 3-4, pp. 217-36
Insights on the Evolution of Prolyl 3-Hydroxylation Sites from Comparative Analysis of Chicken and Xenopus Fibrillar Collagens
Recessive mutations that prevent 3-hydroxyproline formation in type I collagen have been shown to cause forms of osteogenesis imperfecta. In mammals, all A-clade collagen chains with a GPP sequence at the A1 site (P986), except α1(III), have 3Hyp at residue P986. Available avian, amphibian and reptilian type III collagen sequences from the genomic database (Ensembl) all differ in sequence motif from mammals at the A1 site. This suggests a potential evolutionary distinction in prolyl 3-hydroxylation between mammals and earlier vertebrates. Using peptide mass spectrometry, we confirmed that this 3Hyp site is fully occupied in α1(III) from an amphibian, Xenopus laevis, as it is in chicken. A thorough characterization of all predicted 3Hyp sites in collagen types I, II, III and V from chicken and xenopus revealed further differences in the pattern of occupancy of the A3 site (P707). In mammals only α2(I) and α2(V) chains had any 3Hyp at the A3 site, whereas in chicken all α-chains except α1(III) had A3 at least partially 3-hydroxylated. The A3 site was also partially 3-hydroxylated in xenopus α1(I). Minor differences in covalent cross-linking between chicken, xenopus and mammal type I and III collagens were also found as a potential index of evolving functional differences. The function of 3Hyp is still unknown but observed differences in site occupancy during vertebrate evolution are likely to give important clues
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Hair organ regeneration via the bioengineered hair follicular unit transplantation
Organ regenerative therapy aims to reproduce fully functional organs to replace organs that have been lost or damaged as a result of disease, injury, or aging. For the fully functional regeneration of ectodermal organs, a concept has been proposed in which a bioengineered organ is developed by reproducing the embryonic processes of organogenesis. Here, we show that a bioengineered hair follicle germ, which was reconstituted with embryonic skin-derived epithelial and mesenchymal cells and ectopically transplanted, was able to develop histologically correct hair follicles. The bioengineered hair follicles properly connected to the host skin epithelium by intracutaneous transplantation and reproduced the stem cell niche and hair cycles. The bioengineered hair follicles also autonomously connected with nerves and the arrector pili muscle at the permanent region and exhibited piloerection ability. Our findings indicate that the bioengineered hair follicles could restore physiological hair functions and could be applicable to surgical treatments for alopecia
A cross-sectional survey of the prevalence of environmental tobacco smoke preventive care provision by child health services in Australia
Background: Despite the need for a reduction in levels of childhood exposure to environmental tobacco smoke (ETS) being a recognised public health goal, the delivery of ETS preventive care in child health service settings remains a largely unstudied area. The purpose of this study was to determine the prevalence of ETS preventive care in child health services; differences in the provision of care by type of service; the prevalence of strategies to support such care; and the association between care support strategies and care provision. Method: One-hundred and fifty-one (83%) child health service managers within New South Wales, Australia completed a questionnaire in 2002 regarding the: assessment of parental smoking and child ETS exposure; the provision of parental smoking cessation and ETS-exposure reduction advice; and strategies used to support the provision of such care. Child health services were categorised based on their size and case-mix, and a chi-square analysis was performed to compare the prevalence of ETS risk assessment and ETS prevention advice between service types. Logistic regression analysis was used to examine associations between the existence of care support strategies and the provision of ETS risk assessment and ETS exposure prevention advice. Results: A significant proportion of services reported that they did not assess parental smoking status (26%), and reported that they did not assess the ETS exposure (78%) of any child. Forty four percent of services reported that they did not provide smoking cessation advice and 20% reported they did not provide ETS exposure prevention advice. Community based child and family health services reported a greater prevalence of ETS preventive care compared to other hospital based units. Less than half of the services reported having strategies to support the provision of ETS preventive care. The existence of such support strategies was associated with greater odds of care provision. Conclusions: The existence of major gaps in recommended ETS preventive care provision suggests a need for additional initiatives to increase such care delivery. The low prevalence of strategies that support such care delivery suggests a potential avenue to achieve this outcome
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