744 research outputs found

    DISEÑO DE POLÍTICAS PÚBLICAS E INSTITUCIONALES CON UN ENFOQUE MULTIRREFERENCIADO: APLICACIÓN AL CAMPO EDUCATIVO

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    El Diseño de Políticas Públicas e Institucionales enfrenta una gran dificultad, que es la complejidad creciente tanto de las problemáticas a resolver como de los contextos sociales de su aplicación. El objetivo de este trabajo es contribuir al mejoramiento de dicho diseño, compensando las limitaciones de los marcos teóricos utilizados para modelizar la realidad estudiada, mediante un enfoque multirreferenciado en teorías diversas. Para fundamentarlo, desde el contexto de explicación se desarrolla el concepto de Puntos Ciegos de la Teoría, y desde el contexto de aplicación, se desarrolla el concepto de Viabilidad de la Teoría. Se ilustra esto con ejemplos provenientes de diversos campos de conocimiento, con énfasis en el campo educativo. A partir del concepto de Viabilidad Contextual de las Teorías se legitima la concepción de las mismas como herramientas de modelización de lo real con diverso grado de aplicabilidad a situaciones concretas, según los fines que se persigan. Se trata de demostrar la legitimidad del uso concurrente de teorías diversas para situaciones y fines diversos. Concluyendo que la complejidad del campo educativo requiere de cierto eclecticismo teórico en su abordaje

    Characterizing client usage patterns and service demand for car-sharing systems

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    The understanding of the mobility on urban spaces is useful for the creation of smarter and sustainable cities. However, getting data about urban mobility is challenging, since only a few companies have access to accurate and updated data, that is also privacy-sensitive. In this work, we characterize three distinct car-sharing systems which operate in Vancouver (Canada) and nearby regions, gathering data for more than one year. Our study uncovers patterns of users’ habits and demands for these services. We highlight the common characteristics and the main differences among car-sharing systems. Finally, we believe our study and data is useful for generating realistic synthetic workloads

    Prevalence and patterns of antimicrobial resistance among escherichia coli and staphylococcus spp. In a veterinary university hospital

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    The occurrence of antimicrobial resistance in commensal strains of Escherichia coli and Staphylococcus spp. was investigated in 320 samples collected from patients and the environment of a veterinary university hospital—specifically, the consultation area (CA) and intensive care unit (ICU). E. coli was isolated in 70/160 samples (44%), while Staphylococcus spp. were isolated in 110/160 (69%) samples. The occurrence of multidrug-resistant (MDR) isolates from CA and ICU admission were similar for E. coli (1/12 (8%) versus 4/27 (15%), respectively) and Staphylococcus spp. (10/19 (53%) versus 26/50 (52%), respectively). MDR E. coli isolates increased significantly at hospital discharge (18/31; 58%; p = 0.008). Antimicrobial treatment administered during hospitalization was a risk factor for carriage of MDR E. coli (OR, 23.9; 95% CI: 1.18–484.19; p = 0.04) and MDR Staphylococcus spp. (OR, 19.5; 95% CI 1.30–292.76; p = 0.02), respectively. The odds ratio for MDR E. coli was 41.4 (95% CI 2.13–806.03; p = 0.01), if the administration of fluoroquinolones was evaluated. The mecA gene was detected in 19/24 (79%) coagulase-positive Staphylococcus spp. isolates resistant to oxacillin. High rates of MDR Staphylococcus spp. were reported. Hospitalization in the ICU and antimicrobial treatment were risk factors for colonization by MDR commensal bacteria

    Anisakid and Raphidascaridid parasites in Trachurus trachurus: infection drivers and possible effects on the host’s condition

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    This study investigated the distribution of nematode larvae of Anisakidae and Raphidascarididae (genera Anisakis and Hysterothylacium) in Trachurus trachurus (Linnaeus, 1758) in the Ligurian and central-northern Tyrrhenian Seas. The relationship between the number of parasites and the length and weight parameters of the fish was assessed, and the possible effect of the parasites on the condition factor was evaluated. A total of 190 T. trachurus specimens were collected in July 2019. Parasites were found in 70 individuals. A total of 161 visible larvae were collected in the viscera. Morphological analysis revealed the presence of Anisakis spp. in 55 fish and Hysterothylacium spp. in 15 fish, while 5 fish showed coinfection with both genera. The specimens subjected to PCR (n = 67) showed that 85% of the Anisakis larvae analyzed belonged to the species A. pegreffii, while the remaining 15% belonged to hybrids of A. pegreffii-A. simplex (s.s.). A total of 58% (n = 7) of the Hysterothylacium larvae analyzed belonged to the species H. fabri, while 42% belonged to the species H. aduncum. Our results support the hypothesis that infection with these parasites does not affect the condition of the fish host analyzed, and that body size and depth are major drivers in determining infection levels with Anisakid and Raphidascaridid nematodes

    Characterization of the microbiome of the invasive Asian toad in Madagascar across the expansion range and comparison with a native co-occurring species

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    Biological invasions are on the rise, with each invader carrying a plethora of associated microbes. These microbes play important, yet poorly understood, ecological roles that can include assisting the hosts in colonization and adaptation processes or as possible pathogens. Understanding how these communities differ in an invasion scenario may help to understand the host's resilience and adaptability. The Asian common toad, Duttaphrynus melanostictus is an invasive amphibian, which has recently established in Madagascar and is expected to pose numerous threats to the native ecosystems. We characterized the skin and gut bacterial communities of D. melanostictus in Toamasina (Eastern Madagascar), and compared them to those of a co-occurring native frog species, Ptychadena mascareniensis, at three sites where the toad arrived in different years. Microbial composition did not vary among sites, showing that D. melanostictus keeps a stable community across its expansion but significant differences were observed between these two amphibians. Moreover, D. melanostictus had richer and more diverse communities and also harboured a high percentage of total unique taxa (skin: 80%; gut: 52%). These differences may reflect the combination of multiple host-associated factors including microhabitat selection, skin features and dietary preferences

    Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change

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    Background: Approximately two hundred human burials were discovered on the edge of a paleolake in Niger that providea uniquely preserved record of human occupation in the Sahara during the Holocene (,8000 B.C.E. to the present). CalledGobero, this suite of closely spaced sites chronicles the rapid pace of biosocial change in the southern Sahara in response tosevere climatic fluctuation.Methodology/Principal Findings: Two main occupational phases are identified that correspond with humid intervals in theearly and mid-Holocene, based on 78 direct AMS radiocarbon dates on human remains, fauna and artifacts, as well as 9 OSLdates on paleodune sand. The older occupants have craniofacial dimensions that demonstrate similarities with mid-Holocene occupants of the southern Sahara and Late Pleistocene to early Holocene inhabitants of the Maghreb. Theirhyperflexed burials compose the earliest cemetery in the Sahara dating to ,7500 B.C.E. These early occupants abandon thearea under arid conditions and, when humid conditions return ,4600 B.C.E., are replaced by a more gracile people withelaborated grave goods including animal bone and ivory ornaments.Conclusions/Significance: The principal significance of Gobero lies in its extraordinary human, faunal, and archaeologicalrecord, from which we conclude the following:(1) The early Holocene occupants at Gobero (7700–6200 B.C.E.) were largely sedentary hunter-fisher-gatherers withlakeside funerary sites that include the earliest recorded cemetery in the Sahara.(2) Principal components analysis of craniometric variables closely allies the early Holocene occupants at Gobero with askeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreband southern Sahara.(3) Gobero was abandoned during a period of severe aridification possibly as long as one millennium (6200–5200 B.C.E).(4) More gracile humans arrived in the mid-Holocene (5200–2500 B.C.E.) employing a diversified subsistence economybased on clams, fish, and savanna vertebrates as well as some cattle husbandry.(5) Population replacement after a harsh arid hiatus is the most likely explanation for the occupational sequence at Gobero.(6) We are just beginnin

    Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions

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    We describe a measurement of the charge asymmetry of leptons from W boson decays in the rapidity range 0 enu, munu events from 110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The asymmetry data constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry predictions that use parton distribution functions obtained from previously published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur

    Production of Y(1S) Mesons from chib Decays in pp(bar) Collisions at sqrt(s)=1.8 TeV

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    We have reconstructed the radiative decays χb(1P)Υ(1S)γ\chi_{b}(1P) \to \Upsilon(1S) \gamma and χb(2P)Υ(1S)γ\chi_{b}(2P) \to \Upsilon(1S) \gamma in ppˉp \bar{p} collisions at s=1.8\sqrt{s} = 1.8 TeV, and measured the fraction of Υ(1S)\Upsilon(1S) mesons that originate from these decays. For Υ(1S)\Upsilon(1S) mesons with pTΥ>8.0p^{\Upsilon}_{T}>8.0 GeV/cc, the fractions that come from χb(1P)\chi_{b}(1P) and χb(2P)\chi_{b}(2P) decays are (27.1±6.9(stat)±4.4(sys))(27.1\pm6.9(stat)\pm4.4(sys))% and (10.5±4.4(stat)±1.4(sys))(10.5\pm4.4(stat)\pm1.4(sys))%, respectively. We have derived the fraction of directly produced Υ(1S)\Upsilon(1S) mesons to be (50.9±8.2(stat)±9.0(sys))(50.9\pm8.2(stat)\pm9.0(sys))%.Comment: 13 Pages, 2 figure

    Measurement of the Helicity of W Bosons in Top Quark Decays

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    We use the transverse momentum spectrum of leptons in the decay chain t-->bW with W-->l nu to measure the helicity of the W bosons in the top quark rest frame. Our measurement uses a ttbar sample isolated in 106 +/- 4 inverse picobarns of data collected in ppbar collisions at sqrt(s)=1.8 TeV with the CDF detector at the Fermilab Tevatron. Assuming a standard V--A weak decay, we find that the fraction of W's with zero helicity in the top rest frame is F_0 = 0.91 +/- 0.37 (stat) +/- 0.13 (syst), consistent with the standard model prediction of F_0=0.70 for a top mass of 175 GeV/c**2.Comment: Submitted to PRL. 8 pages, 2 figure

    Search for a Fourth-Generation Quark More Massive than the Z0 Boson in ppbar Collisions at sqrt(s) = 1.8 TeV

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    We present the results of a search for pair production of a fourth-generation charge -1/3 quark (b') in sqrt(s)=1.8 TeV ppbar collisions using 88 pb^(-1) of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b' -> bZ and that the b' mass is greater than m_Z + m_b. We studied the decay mode b'b'bar -> ZZ b bbar where one Z0 decays into e^+e^- or mu^+ mu^- and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the cross section of ppbar -> b'b'bar times [BR (b' -> bZ)]^2 is established as a function of the b' mass. We exclude at 95% confidence level a b' quark with mass between 100 and 199 GeV/c^2 for BR(b' -> bZ) = 100%.Comment: 12 pages, 2 figures, submitted to Phys. Rev. Letters on 9/12/9
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