3,266 research outputs found
Tinea Cruris Resurgence in Male Genitalia: A Case Report
Tinea infection is a very common disease, but that of the male genitalia is said to be rare. We present a 45 year old male patient suffering from tinea cruris, with lesions extremely chronic and progressive. The patients gave history of empirical treatment and under dosage of antifungal agents with resurgence of the infection. Culture of scrapings from the lesion yielded Epidermophyton floccosum. The case resolved completely with topical tioconazole and oral administration of 50mg fluconazole 3 times a week for six weeks. Patient’s treatment should therefore be guided by laboratory diagnosis and patients should comply with prescribed dosage for better results.Keywords: Tinea cruris, Resurgence, Epidermophyton floccosum, Treatment
Dynamics of a structured slug population model in the absence of seasonal variation
We develop a novel, nonlinear structured population model for the slug Deroceras reticulatum, a highly significant agricultural pest of great economic impact, in both organic and non-organic settings. In the absence of seasonal variations, we numerically explore the effect of life history traits that are dependent on an individual's size and measures of population biomass. We conduct a systematic exploration of parameter space and highlight the main mechanisms and implications of model design. A major conclusion of this work is that strong size dependent predation significantly adjusts the competitive balance, leading to non-monotonic steady state solutions and slowly decaying transients consisting of distinct generational cycles. Furthermore, we demonstrate how a simple ratio of adult to juvenile biomass can act as a useful diagnostic to distinguish between predated and non-predated environments, and may be useful in agricultural settings
Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database
By using updated stellar low mass stars models, we can systematically
investigate the nucleosynthesis processes occurring in AGB stars, when these
objects experience recurrent thermal pulses and third dredge-up episodes. In
this paper we present the database dedicated to the nucleosynthesis of AGB
stars: the FRUITY (FRANEC Repository of Updated Isotopic Tables & Yields)
database. An interactive web-based interface allows users to freely download
the full (from H to Bi) isotopic composition, as it changes after each third
dredge-up episode and the stellar yields the models produce. A first set of AGB
models, having masses in the range 1.5 < M/Msun < 3.0 and metallicities 1e-3 <
Z < 2e-2, is discussed here. For each model, a detailed description of the
physical and the chemical evolution is provided. In particular, we illustrate
the details of the s-process and we evaluate the theoretical uncertainties due
to the parametrization adopted to model convection and mass loss. The resulting
nucleosynthesis scenario is checked by comparing the theoretical [hs/ls] and
[Pb/hs] ratios to those obtained from the available abundance analysis of
s-enhanced stars. On the average, the variation with the metallicity of these
spectroscopic indexes is well reproduced by theoretical models, although the
predicted spread at a given metallicity is substantially smaller than the
observed one. Possible explanations for such a difference are briefly
discussed. An independent check of the third dredge-up efficiency is provided
by the C-stars luminosity function. Consequently, theoretical C-stars
luminosity functions for the Galactic disk and the Magellanic Clouds have been
derived. We generally find a good agreement with observations.Comment: Accepted for Publication on The Astrophysical Journal Supplement
Deep Mixing in Evolved Stars. II. Interpreting Li Abundances in RGB and AGB Stars
We reanalyze the problem of Li abundances in red giants of nearly solar
metallicity. After an outline of the problems affecting our knowledge of the Li
content in low-mass stars (M<3Mo), we discuss deep-mixing models for the RGB
stages suitable to account for the observed trends and for the correlated
variations of the carbon isotope ratio; we find that Li destruction in these
phases is limited to masses below about 2.3 Mo. Subsequently, we concentrate on
the final stages of evolution for both O-rich and C-rich AGB stars. Here, the
constraints on extra-mixing phenomena previously derived from heavier nuclei
(from C to Al), coupled to recent updates in stellar structure models
(including both the input physics and the set of reaction rates used), are
suitable to account for the observations of Li abundances below A(Li)= log
e(Li) = 1.5 (and sometimes more). Also their relations with other
nucleosynthesis signatures of AGB phases (like the abundance of F, the C/O and
12C/13C ratios) can be explained. This requires generally moderate efficiencies
(\dot M <= 0.3 - 0.5 x 10^-6 Mo/yr) for non-convective mass transport. At such
rates, slow extra-mixing does not modify remarkably Li abundances in early-AGB
phases; on the other hand, faster mixing encounters a physical limit in
destroying Li, set by the mixing velocity. Beyond this limit, Li starts to be
produced; therefore its destruction on the AGB is modest. Li is then
significantly produced by the third dredge up. We also show that effective
circulation episodes, while not destroying Li, would easily bring the 12C/13C
ratios to equilibrium, contrary to the evidence in most AGB stars, and would
burn F beyond the limits shown by C(N) giants. Hence, we do not confirm the
common idea that efficient extra-mixing drastically reduces the Li content of
C-stars with respect to K-M giants.Comment: 56 pages, 21 13 figures, ApJ submitte
Galactic Cosmic Rays from Superbubbles and the Abundances of Lithium, Beryllium, and Boron
In this article we study the galactic evolution of the LiBeB elements within
the framework of a detailed model of the chemical evolution of the Galaxy that
includes galactic cosmic ray nucleosynthesis by particles accelerated in
superbubbles. The chemical composition of the superbubble consists of varying
proportions of ISM and freshly supernova synthesized material. The
observational trends of 6 LiBeB evolution are nicely reproduced by models in
which GCR come from a mixture of 25% of supernova material with 75% of ISM,
except for 6 Li, for which maybe an extra source is required at low
metallicities. To account for 7 Li evolution several additional sources have
been considered (neutrino-induced nucleosynthesis, nova outbursts, C-stars).
The model fulfills the energetic requirements for GCR acceleration.Comment: 25 pages, 9 figures. Accepted for publication in the Astrophysical
Journa
The spectral accuracy of a fully-discrete scheme for a nonlinear third order equation
Abstract --Zusammenfassung The Spectral Accuracy of a Fully-Discrete Scheme for a Nonlinear Third Order Equation. A time-discrete pseudospectral algorithm is suggested for the numerical solution of a nonlinear third order equation arising in fluidization. The nonlinear stability and convergence of the new scheme are analyzed. Numerical comparisons with available finite-difference methods are also reported which clearly indicate the superiority of the new scheme. AMS Subject Classification: 65M10 Key words: Spectral method, stability, stability threshold Die spektrale Genauigkeit eines rob diskreten Schemas fdr eine niehtlineare Gieichung dritter Ordnung. Zur numerischen Lfsung einer nichtlinearen Differentialgleichung dritter Ordnung, herriihrend aus einem Str6mungsproblem bei Gasteilchen, wird ein zeitdiskreter Pseudo-spektral-Algorithmus vorgeschlagen. Stabilitfit und Konvergenz des neuen Differenzenverfahrens werden aualysiert. Numerische Vergleiche mit bestehenden Differenzenschemata sprechen klar zugunsten des neuen Verfahrens
Rubidium in the Interstellar Medium
We present observations of interstellar rubidium toward o Per, zeta Per, AE
Aur, HD 147889, chi Oph, zeta Oph, and 20 Aql. Theory suggests that stable 85Rb
and long-lived 87Rb are produced predominantly by high-mass stars, through a
combination of the weak s- and r-processes. The 85Rb/87Rb ratio was determined
from measurements of the Rb I line at 7800 angstroms and was compared to the
solar system meteoritic ratio of 2.59. Within 1-sigma uncertainties all
directions except HD 147889 have Rb isotope ratios consistent with the solar
system value. The ratio toward HD 147889 is much lower than the meteoritic
value and similar to that toward rho Oph A (Federman et al. 2004); both lines
of sight probe the Rho Ophiuchus Molecular Cloud. The earlier result was
attributed to a deficit of r-processed 85Rb. Our larger sample suggests instead
that 87Rb is enhanced in these two lines of sight. When the total elemental
abundance of Rb is compared to the K elemental abundance, the interstellar Rb/K
ratio is significantly lower than the meteoritic ratio for all the sight lines
in this study. Available interstellar samples for other s- and r- process
elements are used to help interpret these results.Comment: 24 pages, 3 figures. Accepted for publication in Ap
Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data
BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer
Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data
BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer
s-Processing in the Galactic Disk. I. Super-Solar Abundances of Y, Zr, La, Ce in Young Open Clusters
In a recent study, based on homogeneous barium abundance measurements in open
clusters, a trend of increasing [Ba/Fe] ratios for decreasing cluster age was
reported. We present here further abundance determinations, relative to four
other elements hav- ing important s-process contributions, with the aim of
investigating whether the growth found for [Ba/Fe] is or not indicative of a
general property, shared also by the other heavy elements formed by slow
neutron captures. In particular, we derived abundances for yttrium, zirconium,
lanthanum and cerium, using equivalent widths measurements and the MOOG code.
Our sample includes 19 open clusters of different ages, for which the spectra
were obtained at the ESO VLT telescope, using the UVES spectrometer. The growth
previously suggested for Ba is confirmed for all the elements analyzed in our
study. This fact implies significant changes in our views of the Galactic
chemical evolution for elements beyond iron. Our results necessarily require
that very low-mass AGB stars (M < 1.5M\odot) produce larger amounts of
s-process elements (hence acti- vate the 13 C-neutron source more effectively)
than previously expected. Their role in producing neutron-rich elements in the
Galactic disk has been so far underestimated and their evolution and
neutron-capture nucleosynthesis should now be reconsidered.Comment: ApJ accepte
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