2,090 research outputs found
Pleosporales
One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
What is Scirrhia?
The ascomycetous genus Scirrhia is presently treated as a member of Dothideomycetidae, though uncertainty remains as to which family it belongs in Capnodiales, Ascomycota. Recent collections on stems of a fern, Pteridium aquilinum (Dennstaedtiaceae) in Brazil, led to the discovery of a new species of Scirrhia, described here as S.
brasiliensis. Based on DNA sequence data of the nuclear ribosomal DNA (LSU), Scirrhia is revealed to represent a member of Dothideomycetes, Capnodiales, Mycosphaerellaceae. Scirrhia is the first confirmed genus in Mycosphaerellaceae to have well developed pseudoparaphyses and a prominent hypostroma in which ascomata are arranged in parallel rows. Given the extremely slow growth rate and difficulty in obtaining cultures of S. brasiliensis on various growth media, it appears that Scirrhia represents a genus of potentially obligate plant pathogens within Mycosphaerellaceae
Clonality and evolutionary history of rhabdomyosarcoma.
To infer the subclonality of rhabdomyosarcoma (RMS) and predict the temporal order of genetic events for the tumorigenic process, and to identify novel drivers, we applied a systematic method that takes into account germline and somatic alterations in 44 tumor-normal RMS pairs using deep whole-genome sequencing. Intriguingly, we find that loss of heterozygosity of 11p15.5 and mutations in RAS pathway genes occur early in the evolutionary history of the PAX-fusion-negative-RMS (PFN-RMS) subtype. We discover several early mutations in non-RAS mutated samples and predict them to be drivers in PFN-RMS including recurrent mutation of PKN1. In contrast, we find that PAX-fusion-positive (PFP) subtype tumors have undergone whole-genome duplication in the late stage of cancer evolutionary history and have acquired fewer mutations and subclones than PFN-RMS. Moreover we predict that the PAX3-FOXO1 fusion event occurs earlier than the whole genome duplication. Our findings provide information critical to the understanding of tumorigenesis of RMS
Low Scale Flavor Gauge Symmetries
We study the possibility of gauging the Standard Model flavor group. Anomaly
cancellation leads to the addition of fermions whose mass is inversely
proportional to the known fermion masses. In this case all flavor violating
effects turn out to be controlled roughly by the Standard Model Yukawa,
suppressing transitions for the light generations. Due to the inverted
hierarchy the scale of new gauge flavor bosons could be as low as the
electroweak scale without violating any existing bound but accessible at the
Tevatron and the LHC. The mechanism of flavor protection potentially provides
an alternative to Minimal Flavor Violation, with flavor violating effects
suppressed by hierarchy of scales rather than couplings.Comment: 24 pages + appendices; v2) Refs. added and numerical examples
improved. Results unchanged; v3) small typos in appendix B correcte
A bi-directional relationship between obesity and health-related quality of life : evidence from the longitudinal AusDiab study
Objective: To assess the prospective relationship between obesity and health-related quality of life, including a novel assessment of the impact of health-related quality of life on weight gain.Design and setting: Longitudinal, national, population-based Australian Diabetes, Obesity and Lifestyle (AusDiab) study, with surveys conducted in 1999/2000 and 2004/2005.Participants: A total of 5985 men and women aged 25 years at study entry.Main outcome measure(s): At both time points, height, weight and waist circumference were measured and self-report data on health-related quality of life from the SF-36 questionnaire were obtained. Cross-sectional and bi-directional, prospective associations between obesity categories and health-related quality of life were assessed.Results: Higher body mass index (BMI) at baseline was associated with deterioration in health-related quality of life over 5 years for seven of the eight health-related quality of life domains in women (all P0.01, with the exception of mental health, P>0.05), and six out of eight in men (all P<0.05, with the exception of role-emotional, P=0.055, and mental health, P>0.05). Each of the quality-of-life domains related to mental health as well as the mental component summary were inversely associated with BMI change (all P<0.0001 for women and P0.01 for men), with the exception of vitality, which was significant in women only (P=0.008). For the physical domains, change in BMI was inversely associated with baseline general health in women only (P=0.023).Conclusions: Obesity was associated with a deterioration in health-related quality of life (including both physical and mental health domains) in this cohort of Australian adults followed over 5 years. Health-related quality of life was also a predictor of weight gain over 5 years, indicating a bi-directional association between obesity and health-related quality of life. The identification of those with poor health-related quality of life may be important in assessing the risk of future weight gain, and a focus on health-related quality of life may be beneficial in weight management strategies.<br /
Gauged Flavor Group with Left-Right Symmetry
We construct an anomaly-free extension of the left-right symmetric model,
where the maximal flavor group is gauged and anomaly cancellation is guaranteed
by adding new vectorlike fermion states. We address the question of the lowest
allowed flavor symmetry scale consistent with data. Because of the mechanism
recently pointed out by Grinstein et al. tree-level flavor changing neutral
currents turn out to play a very weak constraining role. The same occurs, in
our model, for electroweak precision observables. The main constraint turns out
to come from WR-mediated flavor changing neutral current box diagrams,
primarily K - Kbar mixing. In the case where discrete parity symmetry is
present at the TeV scale, this constraint implies lower bounds on the mass of
vectorlike fermions and flavor bosons of 5 and 10 TeV respectively. However,
these limits are weakened under the condition that only SU(2)_R x U(1)_{B-L} is
restored at the TeV scale, but not parity. For example, assuming the SU(2)
gauge couplings in the ratio gR/gL approx 0.7 allows the above limits to go
down by half for both vectorlike fermions and flavor bosons. Our model provides
a framework for accommodating neutrino masses and, in the parity symmetric
case, provides a solution to the strong CP problem. The bound on the lepton
flavor gauging scale is somewhat stronger, because of Big Bang Nucleosynthesis
constraints. We argue, however, that the applicability of these constraints
depends on the mechanism at work for the generation of neutrino masses.Comment: 1+23 pages, 1 table, 5 figures. v3: some more textual fixes (main
change: discussion of Lepton Flavor Violating observables rephrased). Matches
journal versio
Medical causes of admissions to hospital among adults in Africa: a systematic review.
BACKGROUND: Despite the publication of several studies on the subject, there is significant uncertainty regarding the burden of disease among adults in sub-Saharan Africa (sSA). OBJECTIVES: To describe the breadth of available data regarding causes of admission to hospital, to systematically analyze the methodological quality of these studies, and to provide recommendations for future research. DESIGN: We performed a systematic online and hand-based search for articles describing patterns of medical illnesses in patients admitted to hospitals in sSA between 1950 and 2010. Diseases were grouped into bodily systems using International Classification of Disease (ICD) guidelines. We compared the proportions of admissions and deaths by diagnostic category using χ2. RESULTS: Thirty articles, describing 86,307 admissions and 9,695 deaths, met the inclusion criteria. The leading causes of admission were infectious and parasitic diseases (19.8%, 95% confidence interval [CI] 19.6-20.1), respiratory (16.2%, 95% CI 16.0-16.5) and circulatory (11.3%, 95% CI 11.1-11.5) illnesses. The leading causes of death were infectious and parasitic (17.1%, 95% CI 16.4-17.9), circulatory (16%, 95% CI 15.3-16.8) and digestive (16.2%, 95% CI 15.4-16.9). Circulatory diseases increased from 3.9% of all admissions in 1950-59 to 19.9% in 2000-2010 (RR 5.1, 95% CI 4.5-5.8, test for trend p<0.00005). The most prevalent methodological deficiencies, present in two-thirds of studies, were failures to use standardized case definitions and ICD guidelines for classifying illnesses. CONCLUSIONS: Cardiovascular and infectious diseases are currently the leading causes of admissions and in-hospital deaths in sSA. Methodological deficiencies have limited the usefulness of previous studies in defining national patterns of disease in adults. As African countries pass through demographic and health transition, they need to significantly invest in clinical research capacity to provide an accurate description of the disease burden among adults for public health policy
Sphalerons and the Electroweak Phase Transition in Models with Higher Scalar Representations
In this work we investigate the sphaleron solution in a
gauge theory, which also encompasses the Standard Model, with higher scalar
representation(s) (). We show that the field profiles
describing the sphaleron in higher scalar multiplet, have similar trends like
the doublet case with respect to the radial distance. We compute the sphaleron
energy and find that it scales linearly with the vacuum expectation value of
the scalar field and its slope depends on the representation. We also
investigate the effect of gauge field and find that it is small for the
physical value of the mixing angle, and resembles the case for the
doublet. For higher representations, we show that the criterion for strong
first order phase transition, , is relaxed with respect to
the doublet case, i.e. .Comment: 20 pages, 5 figures & 1 table, published versio
Composite Leptoquarks at the LHC
If electroweak symmetry breaking arises via strongly-coupled physics, the
observed suppression of flavour-changing processes suggests that fermion masses
should arise via mixing of elementary fermions with composite fermions of the
strong sector. The strong sector then carries colour charge, and may contain
composite leptoquark states, arising either as TeV scale resonances, or even as
light, pseudo-Nambu-Goldstone bosons. The latter, since they are coupled to
colour, get a mass of the order of several hundred GeV, beyond the reach of
current searches at the Tevatron. The same generic mechanism that suppresses
flavour-changing processes suppresses leptoquark-mediated rare processes,
making it conceivable that the many stringent constraints may be evaded. The
leptoquarks couple predominantly to third-generation quarks and leptons, and
the prospects for discovery at LHC appear to be good. As an illustration, a
model based on the Pati-Salam symmetry is described, and its embedding in
models with a larger symmetry incorporating unification of gauge couplings,
which provide additional motivation for leptoquark states at or below the TeV
scale, is discussed.Comment: 10 pp, version to appear in JHE
Renal cement embolism during percutaneous vertebroplasty
Percutaneous vertebroplasty (PVP) is an effective treatment for lesions of the vertebral body that involves a percutaneous injection of polymethylmethacrylate (PMMA). Although PVP is considered to be minimally invasive, complications can occur during the procedure. We encountered a renal embolism of PMMA in a 57-year-old man that occurred during PVP. This rare case of PMMA leakage occurred outside of the anterior cortical fracture site of the L1 vertebral body, and multiple tubular bone cements migrated to the course of the renal vessels via the valveless collateral venous network surrounding the L1 body. Although the authors could not explain the exact cause of the renal cement embolism, we believe that physicians should be aware of the fracture pattern, anatomy of the vertebral venous system, and careful fluoroscopic monitoring to minimize the risks during the PVP
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