1,659 research outputs found

    Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia

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    Citation: Barhoumi, W., Fares, W., Cherni, S., Derbali, M., Dachraoui, K., Chelbi, I., . . . Zhioua, E. (2016). Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia. International Journal of Environmental Research and Public Health, 13(3), 10. doi:10.3390/ijerph13030329The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL

    Global deletion of Panx3 produces multiple phenotypic effects in mouse humeri and femora

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    © 2016 Anatomical Society. Pannexins form single-membrane channels that allow passage of small molecules between the intracellular and extracellular compartments. Of the three pannexin family members, Pannexin3 (Panx3) is the least studied but is highly expressed in skeletal tissues and is thought to play a role in the regulation of chondrocyte and osteoblast proliferation and differentiation. The purpose of our study is to closely examine the in vivo effects of Panx3 ablation on long bone morphology using micro-computed tomography. Using Panx3 knockout (KO) and wildtype (WT) adult mice, we measured and compared aspects of phenotypic shape, bone mineral density (BMD), cross-sectional geometric properties of right femora and humeri, and lean mass. We found that KO mice have absolutely and relatively shorter diaphyseal shafts compared with WT mice, and relatively larger areas of muscle attachment sites. No differences in BMD or lean mass were found between WT and KO mice. Interestingly, KO mice had more robust femora and humeri compared with WT mice when assessed in cross-section at the midshaft. Our results clearly show that Panx3 ablation produces phenotypic effects in mouse femora and humeri, and support the premise that Panx3 has a role in regulating long bone growth and development

    Recoil correction to the bound-electron g factor in H-like atoms to all orders in αZ\alpha Z

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    The nuclear recoil correction to the bound-electron g factor in H-like atoms is calculated to first order in m/Mm/M and to all orders in αZ\alpha Z. The calculation is performed in the range Z=1-100. A large contribution of terms of order (αZ)5(\alpha Z)^5 and higher is found. Even for hydrogen, the higher-order correction exceeds the (αZ)4(\alpha Z)^4 term, while for uranium it is above the leading (αZ)2(\alpha Z)^2 correction.Comment: 6 pages, 3 tables, 1 figur

    Charged Scalar Particles and τ\tau Leptonic Decay

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    Charged scalar particles introduced in some extensions of the standard model can induce τ\tau leptonic decay at tree level. We find that with some charged SU(2)-singlet scalar particles, like ones introduced in Zee-type models, τ\tau leptonic decay width is always smaller than what is predicted by the standard model, therefore they may offer a natural solution to τ\tau decay puzzle. To be more specific, we examine some Zee-type models in detail to see if at the same time they are acceptable in particle physics, cosmology and astrophysics. It is shown that τ\tau decay data do put some constrains on these models.Comment: ICTP Report No. IC/93/31, 12 pages, Latex, one figure is not included, it is available upon deman

    Calculated Electron Fluxes at Airplane Altitudes

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    A precision measurement of atmospheric electron fluxes has been performed on a Japanese commercial airliner (Enomoto, {\it et al.}, 1991). We have performed a monte carlo calculation of the cosmic ray secondary electron fluxes expected in this experiment. The monte carlo uses the hadronic portion of our neutrino flux cascade program combined with the electromagnetic cascade portion of the CERN library program GEANT. Our results give good agreement with the data, provided we boost the overall normalization of the primary cosmic ray flux by 12\% over the normalization used in the neutrino flux calculation.Comment: in REVTEX, 12 pages + 4 figures available upon reques

    Soft Contributions to Hard Pion Photoproduction

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    Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We estimate the soft contributions to this process, with an eye toward delineating the region where perturbatively calculable processes dominate. Our soft process estimate is based on vector meson dominance and data based parameterizations of semiexclusive hadronic cross sections. We find that soft processes dominate in single pion photoproduction somewhat past 2 GeV transverse momentum at a few times 10 GeV incoming energy. The recent polarization asymmetry data is consistent with the perturbative asymmetry being diluted by polarization insensitive soft processes. Determining the polarized gluon distribution using hard pion photoproduction appears feasible with a few hundred GeV incoming energy (in the target rest frame).Comment: 6 pages, 5 figure

    Inhibiting the coregulator CoREST impairs Foxp3+ Treg function and promotes antitumor immunity

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    Foxp3+ Tregs are key to immune homeostasis, but the contributions of various large, multiprotein complexes that regulate gene expression remain unexplored. We analyzed the role in Tregs of the evolutionarily conserved CoREST complex, consisting of a scaffolding protein, Rcor1 or Rcor2, plus Hdac1 or Hdac2 and Lsd1 enzymes. Rcor1, Rcor2, and Lsd1 were physically associated with Foxp3, and mice with conditional deletion of Rcor1 in Foxp3+ Tregs had decreased proportions of Tregs in peripheral lymphoid tissues and increased Treg expression of IL-2 and IFN-\u3b3 compared with what was found in WT cells. Mice with conditional deletion of the gene encoding Rcor1 in their Tregs had reduced suppression of homeostatic proliferation, inability to maintain long-term allograft survival despite costimulation blockade, and enhanced antitumor immunity in syngeneic models. Comparable findings were seen in WT mice treated with CoREST complex bivalent inhibitors, which also altered the phenotype of human Tregs and impaired their suppressive function. Our data point to the potential for therapeutic modulation of Treg functions by pharmacologic targeting of enzymatic components of the CoREST complex and contribute to an understanding of the biochemical and molecular mechanisms by which Foxp3 represses large gene sets and maintains the unique properties of this key immune cell

    A Biological Circuit Involving Mef2c, Mef2d, and Hdac9 Controls the Immunosuppressive Functions of CD4+Foxp3+ T-Regulatory Cells

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    The Mads/Mef2 (Mef2a/b/c/d) family of transcription factors (TFs) regulates differentiation of muscle cells, neurons and hematopoietic cells. By functioning in physiological feedback loops, Mef2 TFs promote the transcription of their repressor, Hdac9, thereby providing temporal control of Mef2-driven differentiation. Disruption of this feedback is associated with the development of various pathologic states, including cancer. Beside their direct involvement in oncogenesis, Mef2 TFs indirectly control tumor progression by regulating antitumor immunity. We recently reported that in CD4+CD25+Foxp3+ T-regulatory (Treg) cells, Mef2d is required for the acquisition of an effector Treg (eTreg) phenotype and for the activation of an epigenetic program that suppresses the anti-tumor immune responses of conventional T and B cells. We now report that as with Mef2d, the deletion of Mef2c in Tregs switches off the expression of Il10 and Icos and leads to enhanced antitumor immunity in syngeneic models of lung cancer. Mechanistically, Mef2c does not directly bind the regulatory elements of Icos and Il10, but its loss-of-function in Tregs induces the expression of the transcriptional repressor, Hdac9. As a consequence, Mef2d, the more abundant member of the Mef2 family, is converted by Hdac9 into a transcriptional repressor on these loci. This leads to the impairment of Treg suppressive properties in vivo and to enhanced anti-cancer immunity. These data further highlight the central role played by the Mef2/Hdac9 axis in the regulation of CD4+Foxp3+ Treg function and adds a new level of complexity to the analysis and study of Treg biology

    Three-flavor atmospheric neutrino anomaly

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    We investigate the indications of flavor oscillations that come from the anomalous flavor composition of the atmospheric neutrino flux observed in some underground experiments. We study the information coming from the neutrino-induced ÎŒ\mu-like and ee-like events both in the sub-GeV energy range (Kamiokande, IMB, Fr{\'e}jus, and NUSEX experiments) and in the multi-GeV energy range (Kamiokande experiment). First we analyze all the data in the limits of pure ΜΌ↔Μτ\nu_\mu\leftrightarrow\nu_\tau and ΜΌ↔Μe\nu_\mu\leftrightarrow\nu_e oscillations. We obtain that ΜΌ↔Μe\nu_\mu\leftrightarrow\nu_e oscillations provide a better fit, in particular to the multi-GeV data. Then we perform a three-flavor analysis in the hypothesis of dominance of one neutrino square mass difference, m2m^2, implying that the neutrino mixing is parametrized by two angles, (ψ, ϕ)∈[0, π/2](\psi,\,\phi)\in[0,\,\pi/2]. We explore the space (m2, ψ, ϕ)(m^2,\,\psi,\,\phi) exhaustively, and find the regions favored by the oscillation hypothesis. The results are displayed in a form suited to the comparison with other flavor oscillation searches at accelerator, reactor, and solar Îœ\nu experiments. In the analysis, we pay particular attention to the earth matter effects, to the correlation of the uncertainties, and to the symmetry properties of the oscillation probability.Comment: 25 pages (RevTeX) + 12 figures, requires epsfig.sty. All the figures are bitmapped. Postscript figures with full resolution are available at ftp://ftp.sns.ias.edu/pub/lisi/atmpaper
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