1,232 research outputs found

    Comparing different coarse-grained potentials for star polymers

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    We compare different coarse-grained models for star polymers. We find that phenomenological models inspired by the Daoud-Cotton model reproduce quite poorly the thermodynamics of these systems, even if the potential is assumed to be density dependent, as done in the analysis of experimental results. We also determine the minumum value fc of the functionality of the star polymer for which a fluid-solid transition occurs. By applying the Hansen-Verlet criterion we find 35 < fc < 40. This result is confirmed by an analysis based on the modified (reference) hypernetted chain method and is qualitatively consistent with previous work.Comment: 9 pages. In the new version, comments added and a few typos corrected. To appear in J. Chem. Phy

    COVID-19 emergency in the hospital: How the clinical psychology unit is responding

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    The present commentary describes the main care services implemented by the clinical psychology unit of an Italian hospital to cope with the COVID-19 emergency outbreak. The unit's main goal has been to support and protect health care professionals, relatives of hospitalized patients, and patients themselves from further psychological distress. Details and insights are shared. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

    Gravity map of the isla Grande de Tierra de Fuego, and morphology of Lago Fagnano

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    A complete Bouguer gravity map of the central-eastern part of the Isla Grande de Tierra del Fuego, and a general bathymetric chart of the Lago Fagnano have been realized, on the basis of a series of field geophysical surveys carried out on the Island since 1998. The regional gravity anomaly trend onshore shows a progressive negative gradient from N to S. Distinct, broadly E-W-trending gravity minima are superimposed on this regional negative gradient. They follow the main trace of the Magallanes-Fagnano fault system, which represents the western segment of the left-lateral South America-Scotia transform plate boundary. The gravity minima reflect the presence in the subsurface of restricted and elongated basins developed within the principal displacement zone of the fault system. A relative positive gravity maximum is located just at the SE corner of the Lago Fagnano, and represents the response of a partially exposed crystalline body, occupying an area 3 x 3 km wide. A 2D vertical crustal model has been constructed, combining gravity data inversion and geological information available for the central-eastern region of Lago Fagnano. The bathymetric map of the Lago Fagnano delineates the main morphological features of this 110-km-long, 7-km-wide lake, the largest of Isla Grande. The floor is divided into distinct parts, which suggests that the basin is composed of different sub-basins. In most areas, the basin floor is highly asymmetric in shape, with flat depocentral areas. The most pronounced asymmetry of the basin is seen in the eastern end of the lake, where there is also the deepest depression. The steeper slope of the basin, along the northern shore of the Lago Fagnano, also coincides with the most pronounced regional topographic gradient. The general gravimetric and morphological features of the investigated region are here discussed

    Seismostratigraphic and structural setting of the Malvinas Basin and its southern margin (Tierra del fuego Atlantic offshore)

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    New multichannel seismic reflection profiles acquired off the Tierra del Fuego Atlantic margin, from the southern part of the Malvinas foreland basin to the inner sector of the Magallanes fold and thrust belt, combined with available commercial profiles and exploration wells, allowed to outline the sedimentary architecture of the foreland basin and the structure of its deformed southern margin. Five major unconformities were differentiated within the sedimentary fill of the southern Malvinas basin, which neighbours the offshore extension of the Magallanes basin in Tierra del Fuego. The unconformity-bounded units record the corresponding major evolutionary tectonostratigraphic phases of the southern part of the Malvinas basin, and the development of the Magallanes fold-and thrust belt during Mesozoic and Cenozoic times: Unit 1 - Pre-Jurassic basement; Unit 2 - Rift phase (Middle - Upper Jurassic); Unit 3 - Sag phase (Lower ‚Äď Upper Cretaceous); Unit 4 ‚Äď Foredeep transitional phase (Upper Cretaceous - Middle Eocene); Unit 5 - Foreland phase (Middle Eocene - Pleistocene). The southern edge of the Malvinas basin corresponds to the imbricate basement wedges of the Fuegian Cordillera, which shows a thick-skin structural style developed as a consequence of the Middle Tertiary Andean compressional tectonic phase. Large folds, with low angle NE-verging thrusts propagated the shortening basin-ward at shallow structural levels. These structures are superimposed by an array of left-lateral strike-slip lineaments pertaining to the EW trending Magallanes-Fagnano fault system. In the Tierra del Fuego region these structures represent the western segment of the South America ‚Äď Scotia plate boundary. Several Neogene pull-apart basins were formed along the principal deformation zone in correspondence of step-overs and releasing bends. These basins show an evident asymmetry in the sedimentary architecture, and are bounded by sub-vertical faults that in some cases reach the sea-floor. Other transtensional features were also recognized in the inner sector of the fold-and-thrust belt together with the formation of restricted pull-apart basins

    Diabetes and acute bacterial skin and skin structure infections.

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    Acute bacterial skin and skin structures infections (ABSSSIs) are associated with high morbidity, costs and mortality in patients with diabetes mellitus. Their appropriate management should include several figures and a well-organized approach. This review aims to highlight the interplay between diabetes and ABSSSIs and bring out the unmet clinical needs in this area. Pathogenetic mechanisms underlying the increased risk of ABSSSIs in diabetes mellitus are multifactorial: high glucose levels play a crucial pathogenetic role in the tissue damage and delayed clinical cure. Moreover, the presence of diabetes complications (neuropathy, vasculopathy) further complicates the management of ABSSSIs in patients with diabetes. Multidrug resistance organisms should be considered in this population based on patient risk factors and local epidemiology and etiological diagnosis should be obtained whenever possible. Moreover, drug-drug interactions and drug-related adverse events (such as nephrotoxicity) should be considered in the choice of antibiotic therapy. Reducing unnecessary hospitalizations and prolonged length of hospital stay is of primary importance now, more than ever. To achieve these objectives, a better knowledge of the interplay between acute and chronic hyperglycemia, multidrug resistant etiology, and short and long-term outcome is needed. Of importance, a multidisciplinary approach is crucial to achieve full recovery of these patients

    A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays

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    The direct production rates of DD-wave charmonia in the decays of Z0Z^0 is evaluated. The color-octet production processes Z0‚Üí3DJ(ccňČ)qqňČZ^0\rightarrow ^3D_J(c\bar c) q\bar q are shown to have distinctively large branching ratios, the same order of magnitude as that of J/ŌąJ/\psi prodution, as compared with other DD-wave charmonium production mechanisms. This may suggest a crucial channel to test the color-octet mechanism as well as to observe the DD-wave charmonium states in Z0Z^0 decays. In addition, a signal for the 3DJ^3D_J charmonium as strong as J/ŌąJ/\psi or Ōą‚Ä≤\psi^\prime with large transverse momentum at the Tevatron should also be observed.Comment: 14 pages in LaTex (3 figures in PS-file

    Gluon fragmentation to ^3D_J quarkonia

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    We present a calculation of the leading order QCD fragmentation functions for gluons to split into spin-triplet D-wave quarkonia. We apply them to evaluate the gluon fragmentation contributions to inclusive ^3D_J quarkonium production at large transverse momentum processes like the Tevatron and find that the D-wave quarkonia, especially the charmonium 2^{--} state, could be observed through color-octet mechanism with present luminosity. Since there are distinctively large gaps between the contributions of two different (i.e, color-singlet and color-octet) quarkonium production mechanisms, our results may stand as a unique test to NRQCD color-octet quarkonium production mechanism.Comment: 15 pages in LaTex (2 figures in PS-file

    E835 at FNAL: Charmonium Spectroscopy in pňČp\bar p p Annihilations

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    I present preliminary results on the search for hch_c in its ő∑cő≥\eta_c\gamma and J/ŌąŌÄ0J/\psi\pi^0 decay modes. We observe an excess of \eta_c\gammaeventsnear3526MeVthathasaprobability events near 3526 MeV that has a probability {\cal P} \sim 0.001toarisefrombackgroundfluctations.Theresonanceparametersare to arise from background fluctations. The resonance parameters are M=3525.8 \pm 0.2 \pm 0.2 MeV,MeV, \Gamma\leq1MeV,and 1 MeV, and 10.6\pm 3.7\pm3.4(br) < \Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) eV.WefindnoeventexcesswithinthesearchregionintheeV. We find no event excess within the search region in the J/\psi\pi^0$ mode.Comment: Presented at the 6th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2004), Chicago(Il), June 27-July 3,200

    Phosphorus regulates ectomycorrhizal fungi biomass production in a Norway spruce forest

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    Ectomycorrhizal fungi (EMF) are important components of soil microbial communities, and EMF biomass can potentially increase carbon (C) stocks by accumulating in the soils as necromass and producing recalcitrant structures. EMF growth depends on the C allocated belowground by the host trees, and the nutrient limitation on tree growth is expected to influence this allocation. Therefore, studying EMF production and understanding the factors that regulates it in natural soils are important to understand C cycling in forests. Fungal mycelium collected from ingrowth mesh bags is commonly used to estimate EMF biomass, but these measurements might not reflect the total EMF production since turnover rates of the hyphae are not considered. Here we estimated EMF production and turnover in response to P fertilization (applied as superphosphate) in a Norway spruce forest where nitrogen (N) deposition has resulted in phosphorus (P) limitation of plant production by using a combination of mesh bags with different incubation periods and with Bayesian inferences. To test how localized patches of N and P influence EMF production and turnover we amended some bags with a nitrogen source (methylene urea) or P source (apatite). Additionally, the Bayesian model tested the effect of seasonality (time of mesh-bag harvesting) on EMF production and turnover. We found that turnover of EMF was not affected by P fertilization or mesh-bag amendment. P fertilization had a negative effect on EMF production in all the mesh-bag amendments, suggesting a reduced belowground C allocation to the EMF when P limitation is alleviated. Apatite amendment significantly increased EMF biomass production in comparison with the pure quartz bags in the control plots but not in the P-fertilized plots. This indicates that P-rich patches enhance EMF production in P-limited forests, but not when P is not limiting. Urea amendment had a generally positive effect on EMF production, but this was significantly reduced by P fertilization, suggesting that a decrease in EMF production due to the alleviated P limitation will affect N foraging. Seasonality had a significant effect on EMF production, and the differences registered between the treatments were higher during the warmer months and disappeared at the end of the growing season. Many studies highlight the importance of N for regulating belowground C allocation to EMF in northern coniferous forests, but here we show that the P status of the forest can be equally important for belowground carbon allocation to EMF production in areas with high N deposition.</p
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