10,781 research outputs found

    Hyperonic crystallization in hadronic matter

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    Published in Hadrons, Nuclei and Applications, World Scientific, Singapore, Proc.of the Conference Bologna2000. Structure of the Nucleus at the Dawn of the Century, G. Bonsignori, M. Bruno, A. Ventura, D. Vretenar Editors, pag. 319.Comment: 4 pages, 2figure

    The origin of the Acheulean: the 1.7 million-year-old site of FLK West, Olduvai Gorge (Tanzania)

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    The appearance of the Acheulean is one of the hallmarks of human evolution. It represents the emergence of a complex behavior, expressed in the recurrent manufacture of large-sized tools, with standardized forms, implying more advance forethought and planning by hominins than those required by the precedent Oldowan technology. The earliest known evidence of this technology dates back to c. 1.7 Ma. and is limited to two sites (Kokiselei [Kenya] and Konso [Ethiopia]), both of which lack fauna. The functionality of these earliest Acheulean assemblages remains unknown. Here we present the discovery of another early Acheulean site also dating to c. 1.7 Ma from Olduvai Gorge. This site provides evidence of the earliest steps in developing the Acheulean technology and is the oldest Acheulean site in which stone tools occur spatially and functionally associated with the exploitation of fauna. Simple and elaborate large-cutting tools (LCT) and handaxes co-exist at FLK West, showing that complex cognition was present from the earliest stages of the Acheulean. Here we provide a detailed technological study and evidence of the use of these tools on the butchery and consumption of fauna, probably by early Homo erectus sensu lato

    Spatially resolved kinematics in the central 1 kpc of a compact star-forming galaxy at z=2.3 from ALMA CO observations

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    We present high spatial resolution (FWHM\sim0.14'') observations of the CO(878-7) line in GDS-14876, a compact star-forming galaxy at z=2.3z=2.3 with total stellar mass of log(M/M)=10.9\log(M_{\star}/M_{\odot})=10.9. The spatially resolved velocity map of the inner r1r\lesssim1~kpc reveals a continous velocity gradient consistent with the kinematics of a rotating disk with vrot(r=1kpc)=163±5v_{\rm rot}(r=1\rm kpc)=163\pm5 km s1^{-1} and vrot/σ2.5v_{\rm rot}/\sigma\sim2.5. The gas-to-stellar ratios estimated from CO(878-7) and the dust continuum emission span a broad range, fgasCO=Mgas/M=1345%f^{\rm CO}_{\rm gas}=M_{\rm gas}/M_{\star}=13-45\% and fgascont=5067%f^{\rm cont}_{\rm gas}=50-67\%, but are nonetheless consistent given the uncertainties in the conversion factors. The dynamical modeling yields a dynamical mass oflog(Mdyn/M)=10.580.2+0.5\log(M_{\rm dyn}/M_{\odot})=10.58^{+0.5}_{-0.2} which is lower, but still consistent with the baryonic mass, log\log(Mbar_{\rm bar}= M_{\star} + MgasCO^{\rm CO}_{\rm gas}/M_{\odot})=11.0=11.0, if the smallest CO-based gas fraction is assumed. Despite a low, overall gas fraction, the small physical extent of the dense, star-forming gas probed by CO(878-7), 3×\sim3\times smaller than the stellar size, implies a strong concentration that increases the gas fraction up to fgasCO,1kpc85%f^{\rm CO, 1\rm kpc}_{\rm gas}\sim 85\% in the central 1 kpc. Such a gas-rich center, coupled with a high star-formation rate, SFR\sim 500 M_{\odot} yr1^{-1}, suggests that GDS-14876 is quickly assembling a dense stellar component (bulge) in a strong nuclear starburst. Assuming its gas reservoir is depleted without replenishment, GDS-14876 will quickly (tdepl27t_{\rm depl}\sim27 Myr) become a compact quiescent galaxy that could retain some fraction of the observed rotational support.Comment: Accepted for Publication in ApJL. Kinematic maps are shown in Figures 2 and

    The distribution of potential West Nile virus vectors, Culex pipiens pipiens and Culex pipiens quinquefasciatus (Diptera: Culicidae), in Mexico City

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    <p>Abstract</p> <p>Background</p> <p><it>Culex </it>spp. mosquitoes are considered to be the most important vectors of West Nile virus (WNV) detected in at least 34 species of mosquitoes in the United States. In North America, <it>Culex pipiens pipiens, Culex pipiens quinquefasciatus</it>, and <it>Culex tarsalis </it>are all competent vectors of WNV, which is considered to be enzootic in the United States and has also been detected in equines and birds in many states of Mexico and in humans in Nuevo Leon. There is potential for WNV to be introduced into Mexico City by various means including infected mosquitoes on airplanes, migrating birds, ground transportation and infected humans. Little is known of the geographic distribution of <it>Culex pipiens </it>complex mosquitoes and hybrids in Mexico City. <it>Culex pipiens pipiens </it>preferentially feed on avian hosts; <it>Culex pipiens quinquefasciatus </it>have historically been considered to prefer mammalian hosts; and hybrids of these two species could theoretically serve as bridge vectors to transmit WNV from avian hosts to humans and other mammalian hosts. In order to address the potential of WNV being introduced into Mexico City, we have determined the identity and spatial distribution of <it>Culex pipiens </it>complex mosquitoes and their hybrids.</p> <p>Results</p> <p>Mosquito larvae collected from 103 sites throughout Mexico City during 2004-2005 were identified as <it>Culex, Culiseta </it>or <it>Ochlerotatus </it>by morphological analysis. Within the genus <it>Culex</it>, specimens were further identified as <it>Culex tarsalis </it>or as belonging to the <it>Culex pipiens </it>complex. Members of the <it>Culex pipiens </it>complex were separated by measuring the ratio of the dorsal and ventral arms (DV/D ratio) of the male genitalia and also by using diagnostic primers designed for the <it>Ace.2 </it>gene. <it>Culex pipiens quinquefasciatus </it>was the most abundant form collected.</p> <p>Conclusions</p> <p>Important WNV vectors species, <it>Cx. p. pipiens</it>, <it>Cx. p. quinquefasciatus </it>and <it>Cx. tarsalis</it>, are all present in Mexico City. Hybrids of <it>Cx. p. pipiens </it>and <it>Cx. p. quinquefasciatus </it>were also collected and identified. The presence and abundance of these WNV competent vectors is a cause for concern. Understanding the distribution of these vectors can help improve viral surveillance activities and mosquito control efforts in Mexico City.</p

    Seasonal variations of carcass characteristics, meat quality and nutrition value in iberian wild red deer

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    Aim of study: The effects of hunting season (autumn vs. winter) on carcass characteristics and meat quality of Iberian wild red deer were assessed. Area of study: A total of 100 males of wild red deer of Iberian genetic line (Cervus elaphus) were hunted on Ciudad Real (south central Spain). Material and methods: Yields for shoulder (with bone), neck, backbone, loin, tenderloin, leg (with bone), short plate and flank were determined. In addition, samples of Longissimus thoracis et lumborum and Rectus abdominis muscles were collected. Then, pH48, colour measurements, chemical composition, cooking loss, Warner Bratzler shear blade, fatty acid and amino acid profiles and mineral content were analyzed. Main results: Deer hunted in autumn (n=50) had higher (p&lt;0.01) yields of shoulder, backbone and short plate and higher contents of intramuscular fat (IMF), cholesterol and K, Fe and Mn but lower (p&lt;0.001) pH48 and Na, Mg, Zn and Cu contents than deer hunted in winter (n=50). Shear force tended (p=0.05) to be lower for meat collected in autumn than for meat collected in winter. However, loin yield was 59.2% higher (p&lt;0.001) for winter than for autumn carcasses. Deer hunted in winter had higher α-linoleic acid (p&lt;0.05) and long chain n-3 polyunsaturated (p&lt;0.001) percentages than deer hunted in autumn Research highlights: Autumn hunting is recommended to obtain carcasses with higher yields of shoulder, backbone and short plate and meat with higher IMF. Conversely, winter hunting is advisable for higher loin yield and for a profile richer in polyunsaturated fatty acids

    Serum melatonin levels during the first seven days of severe sepsis diagnosis are associated with sepsis severity and mortality

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    Objective: Higher serum melatonin levels have previously been found in patients with severe sepsis who died within 30 days of diagnosis than in survivors. The objective of our study were to determine whether serum melatonin levels during the first seven days of severe sepsis diagnosis could be associated with sepsis severity and mortality. Methods: Multicentre study in eight Spanish Intensive Care Units which enrolled 308 patients with severe sepsis. We determined serum levels of melatonin, malondialdehyde (as biomarker of lipid peroxidation) and tumor necrosis factor-alpha at days 1, 4 and 8 of severe sepsis diagnosis. The study's primary endpoint was 30-day mortality. Results: A total of 103 patients had died and 205 survived at 30 days of severe sepsis diagnosis, with the non-survivors presenting higher serum melatonin levels at days 1 (p<0.001), 4 (p<0.001) and 8 (p<0.001) of severe sepsis diagnosis than the survivor patient group. The multiple logistic regression analysis found that serum melatonin levels at days 1, 4 and 8 of severe sepsis diagnosis (p<0.001, p = 0.01 and p = 0.001, respectively) were associated with mortality adjusted for age, serum lactic acid, SOFA score and diabetes mellitus. Conclusions: The novel and more interesting findings of our study were that serum melatonin levels during the first seven days of severe sepsis diagnosis are associated with sepsis severity and mortality. (C) 2017 Elsevier Espana, S.L.U. and Sociedad Espanola de Enfermedades lnfecciosas y Microbiologia Clinica

    Multiwavelength study of the starburst galaxy NGC7714. I: Ultraviolet-Optical spectroscopy

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    We have studied the physical conditions in the central 300 pc of the proto-typical starburst galaxy NGC 7714. Our analysis is based on ultraviolet spectroscopy with the HST+GHRS and ground-based optical observations.The data are interpreted using evolutionary models optimized for young starburst regions. The massive stellar population is derived in a self-consistent way using the continuum and stellar absorption lines in the ultraviolet and the nebular emission line optical spectrum. The central starburst has an age of about 4.5 Myr, with little evidence for an age spread. Wolf-Rayet features at the ultraviolet indicates a stellar population of \sim 2000 Wolf-Rayet stars. The overall properties of the newly formed stars are quite similar to those derived, e.g., in 30 Doradus. A standard Salpeter IMF is consistent with all observational constraints. We find evidence for spatial structure within the central 300 pc sampled. Therefore it is unlikely that the nucleus of NGC 7714 hosts a single star cluster exceeding the properties of other known clusters. Contrary to previous suggestions, we find no evidence for a nuclear supernova rate that would significantly exceed the total disk-integrated rate. About one supernova event per century is predicted.Comment: 19 pages, 9 figures in a tar file. Accepted for publication in ApJ, 1999, March, issue 51

    Extreme Starbursts in the Local Universe

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    The "Extreme starbursts in the local universe" workshop was held at the Insituto de Astrofisica de Andalucia in Granada, Spain on 21-25 June 2010. Bearing in mind the advent of a new generation of facilities such as JWST, Herschel, ALMA, eVLA and eMerlin, the aim of the workshop was to bring together observers and theorists to review the latest results. The purpose of the workshop was to address the following issues: what are the main modes of triggering extreme starbursts in the local Universe? How efficiently are stars formed in extreme starbursts? What are the star formation histories of local starburst galaxies? How well do the theoretical simulations model the observations? What can we learn about starbursts in the distant Universe through studies of their local counterparts? How important is the role of extreme starbursts in the hierarchical assembly of galaxies? How are extreme starbursts related to the triggering of AGN in the nuclei of galaxies? Overall, 41 talks and 4 posters with their corresponding 10 minutes short talks were presented during the workshop. In addition, the workshop was designed with emphasis on discussions, and therefore, there were 6 discussion sessions of up to one hour during the workshop. Here is presented a summary of the purposes of the workshop as well as a compilation of the abstracts corresponding to each of the presentations. The summary and conclusions of the workshop along with a description of the future prospects by Sylvain Veilleux can be found in the last section of this document. A photo of the assistants is included.Comment: worksho

    Imaging mass cytometry analysis of Becker muscular dystrophy muscle samples reveals different stages of muscle degeneration

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    \ua9 2024. The Author(s). Becker muscular dystrophy (BMD) is characterised by fiber loss and expansion of fibrotic and adipose tissue. Several cells interact locally in what is known as the degenerative niche. We analysed muscle biopsies of controls and BMD patients at early, moderate and advanced stages of progression using Hyperion imaging mass cytometry (IMC) by labelling single sections with 17 markers identifying different components of the muscle. We developed a software for analysing IMC images and studied changes in the muscle composition and spatial correlations between markers across disease progression. We found a strong correlation between collagen-I and the area of stroma, collagen-VI, adipose tissue, and M2-macrophages number. There was a negative correlation between the area of collagen-I and the number of satellite cells (SCs), fibres and blood vessels. The comparison between fibrotic and non-fibrotic areas allowed to study the disease process in detail. We found structural differences among non-fibrotic areas from control and patients, being these latter characterized by increase in CTGF and in M2-macrophages and decrease in fibers and blood vessels. IMC enables to study of changes in tissue structure along disease progression, spatio-temporal correlations and opening the door to better understand new potential pathogenic pathways in human samples
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