6,932 research outputs found

    A Study of the Formal Architectural-Sculptural Characteristics of El Tajin

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    El TajĂ­n was an ancient metropolis in which rituals such as the Mesoamerican ball game were carried out, later to be recorded in the sculptural bas-reliefs of its architecture. The study of its morphologies is the recognition of the ways in which an ancient civilization is expressed, thus contributing to the characterization of a culture whose past belongs to World Heritage. This paper proposes a case-sample analysis of the bas-reliefs in the South Ballcourt based on reticular geometry and fractal dimension analysis. It was found that the geometry of the RA (golden rectangle), RR2 and RR3 are prevalent, in addition to the identification of iconographic naturalist and symbolic elements; from the box-counting fractal dimension, it was found that the elements, though of different sizes or composition, show similar complexities, with a value of around 1.7

    Bovipain-2, the falcipain-2 ortholog, is expressed in intraerythrocytic stages of the tick-transmitted hemoparasite Babesia bovis

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    <p>Abstract</p> <p>Background</p> <p>Cysteine proteases have been shown to be highly relevant for Apicomplexan parasites. In the case of <it>Babesia bovis</it>, a tick-transmitted hemoparasite of cattle, inhibitors of these enzymes were shown to hamper intraerythrocytic replication of the parasite, underscoring their importance for survival.</p> <p>Results</p> <p>Four papain-like cysteine proteases were found to be encoded by the <it>B. bovis </it>genome using the MEROPS database. One of them, the ortholog of <it>Plasmodium falciparum </it>falcipain-2, here named bovipain-2, was further characterized. Bovipain-2 is encoded in <it>B. bovis </it>chromosome 4 by an ORF of 1.3 kb, has a predicted molecular weight of 42 kDa, and is hydrophilic with the exception of a transmembrane region. It has orthologs in several other apicomplexans, and its predicted amino acid sequence shows a high degree of conservation among several <it>B. bovis </it>isolates from North and South America. Synteny studies demonstrated that the <it>bovipain-2 </it>gene has expanded in the genomes of two related piroplasmids, <it>Theileria parva </it>and <it>T. annulata</it>, into families of 6 and 7 clustered genes respectively. The <it>bovipain-2 g</it>ene is transcribed in <it>in vitro </it>cultured intra-erythrocyte forms of a virulent and an attenuated <it>B. bovis </it>strain from Argentina, and has no introns, as shown by RT-PCR followed by sequencing. Antibodies against a recombinant form of bovipain-2 recognized two parasite protein bands of 34 and 26 kDa, which coincide with the predicted sizes of the pro-peptidase and mature peptidase, respectively. Immunofluorescence studies showed an intracellular localization of bovipain-2 in the middle-rear region of <it>in vitro </it>cultured merozoites, as well as diffused in the cytoplasm of infected erythrocytes. Anti-bovipain-2 antibodies also reacted with <it>B. bigemina</it>-infected erythrocytes giving a similar pattern, which suggests cross-reactivity among these species. Antibodies in sera of two out of six <it>B. bovis</it>-experimentally infected bovines tested, reacted specifically with recombinant bovipain-2 in immunoblots, thus demonstrating expression and immunogenicity during bovine-infecting stages.</p> <p>Conclusions</p> <p>Overall, we present the characterization of bovipain-2 and demonstrate its <it>in vitro </it>and <it>in vivo </it>expression in virulent and attenuated strains. Given the involvement of apicomplexan cysteine proteases in essential parasite functions, bovipain-2 constitutes a new vaccine candidate and potential drug target for bovine babesiosis.</p

    Genetic diversity of Mycobacterium tuberculosis in Peru and exploration of phylogenetic associations with drug resistance.

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    BACKGROUND: There is limited available data on the strain diversity of M tuberculosis in Peru, though there may be interesting lessons to learn from a setting where multidrug resistant TB has emerged as a major problem despite an apparently well-functioning DOTS control programme. METHODS: Spoligotyping was undertaken on 794 strains of M tuberculosis collected between 1999 and 2005 from 553 community-based patients and 241 hospital-based HIV co-infected patients with pulmonary tuberculosis in Lima, Peru. Phylogenetic and epidemiologic analyses permitted identification of clusters and exploration of spoligotype associations with drug resistance. RESULTS: Mean patient age was 31.9 years, 63% were male and 30.4% were known to be HIV+. Rifampicin mono-resistance, isoniazid mono-resistance and multidrug resistance (MDR) were identified in 4.7%, 8.7% and 17.3% of strains respectively. Of 794 strains from 794 patients there were 149 different spoligotypes. Of these there were 27 strains (3.4%) with novel, unique orphan spoligotypes. 498 strains (62.7%) were clustered in the nine most common spoligotypes: 16.4% SIT 50 (clade H3), 12.3% SIT 53 (clade T1), 8.3% SIT 33 (LAM3), 7.4% SIT 42 (LAM9), 5.5% SIT 1 (Beijing), 3.9% SIT 47 (H1), 3.0% SIT 222 (clade unknown), 3.0% SIT1355 (LAM), and 2.8% SIT 92 (X3). Amongst HIV-negative community-based TB patients no associations were seen between drug resistance and specific spoligotypes; in contrast HIV-associated MDRTB, but not isoniazid or rifampicin mono-resistance, was associated with SIT42 and SIT53 strains. CONCLUSION: Two spoligotypes were associated with MDR particularly amongst patients with HIV. The MDR-HIV association was significantly reduced after controlling for SIT42 and SIT53 status; residual confounding may explain the remaining apparent association. These data are suggestive of a prolonged, clonal, hospital-based outbreak of MDR disease amongst HIV patients but do not support a hypothesis of strain-specific propensity for the acquisition of resistance-conferring mutations

    Microplate technique to determine hemolytic activity for routine typing of Listeria strains

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    Because the hemolysis produced by Listeria monocytogenes and Listeria seeligeri on blood agar is frequently difficult to interpret, we developed a microplate technique for the routine determination of hemolytic activity with erythrocyte suspensions. This microtechnique is a simple and reliable test for distinguishing clearly between hemolytic and nonhemolytic strains and could be used instead of the CAMP (Christie-Atkins-Munch-Petersen) test with Staphylococcus aureus in the routine typing of Listeria strains. Furthermore, our results suggest that the quantitation of the hemolytic activity of the Listeria strains, along with the D-xylose, L-rhamnose, and alpha-methyl-D-mannoside acidification tests, allows the differentiation of L. monocytogenes, L. seeligeri, and Listeria ivanovii. We also observed that the treatment of erythrocytes with crude exosubstances of rhodococcus equi, Pseudomonas fluorescens, Acinetobacter calcoaceticus, and S. aureus enhanced the hemolytic activity of all Listeria strains with this characteristic

    Event generator tunes obtained from underlying event and multiparton scattering measurements

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    New sets of parameters (“tunes”) for the underlying-event (UE) modelling of the PYTHIA8, PYTHIA6 and HERWIG++ MonteCarlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton–proton (pp) data at √s = 7 TeV and to UE proton–antiproton (pp) data from the CDF experiment at lower √s, are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton–proton collisions at 13 TeV. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons are presented of the UE tunes to “minimum bias” (MB) events, multijet, and Drell– Yan (qq → Z/γ*→lepton-antilepton+jets) observables at 7 and 8 TeV, as well as predictions for MB and UE observables at 13 TeV

    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

    Measurement of the differential cross section and charge asymmetry for inclusive pp → W\u3csup\u3e±\u3c/sup\u3e + \u3ci\u3eX\u3c/i\u3e production at √\u3ci\u3es\u3c/i\u3e = 8 TeV

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    The differential cross section and charge asymmetry for inclusive pp → W± + X → μ±ν + X production at √s = 8 TeV are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8 fb−1 recorded with the CMS detector at the LHC. These results provide important constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from 10−3 to 10−1

    The Schro¨\ddot{o}dinger-Poisson equations as the large-N limit of the Newtonian N-body system: applications to the large scale dark matter dynamics

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    In this paper it is argued how the dynamics of the classical Newtonian N-body system can be described in terms of the Schro¨\ddot{o}dinger-Poisson equations in the large NN limit. This result is based on the stochastic quantization introduced by Nelson, and on the Calogero conjecture. According to the Calogero conjecture, the emerging effective Planck constant is computed in terms of the parameters of the N-body system as ℏ∼M5/3G1/2(N/)1/6\hbar \sim M^{5/3} G^{1/2} (N/)^{1/6}, where is GG the gravitational constant, NN and MM are the number and the mass of the bodies, and is their average density. The relevance of this result in the context of large scale structure formation is discussed. In particular, this finding gives a further argument in support of the validity of the Schro¨\ddot{o}dinger method as numerical double of the N-body simulations of dark matter dynamics at large cosmological scales.Comment: Accepted for publication in the Euro. Phys. J.

    Assessment of PaO2/FiO2 for stratification of patients with moderate and severe acute respiratory distress syndrome

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    Objectives: A recent update of the definition of acute respiratory distress syndrome (ARDS) proposed an empirical classification based on ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) at ARDS onset. Since the proposal did not mandate PaO2/FiO2 calculation under standardised ventilator settings (SVS), we hypothesised that a stratification based on baseline PaO2/FiO2 would not provide accurate assessment of lung injury severity. Design: A prospective, multicentre, observational study. Setting: A network of teaching hospitals. Participants: 478 patients with eligible criteria for moderate (100300). Primary and secondary outcomes Group severity and hospital mortality. Results: At ARDS onset, 173 patients had a PaO2/FiO2≤100 but only 38.7% met criteria for severe ARDS at 24 h under SVS. When assessed under SVS, 61.3% of patients with severe ARDS were reclassified as moderate, mild and non-ARDS, while lung severity and hospital mortality changed markedly with every PaO2/FiO2 category (p<0.000001). Our model of risk stratification outperformed the stratification using baseline PaO2/FiO2 and non-standardised PaO2/FiO2 at 24 h, when analysed by the predictive receiver operating characteristic (ROC) curve: area under the ROC curve for stratification at baseline was 0.583 (95% CI 0.525 to 0.636), 0.605 (95% CI 0.552 to 0.658) at 24 h without SVS and 0.693 (95% CI 0.645 to 0.742) at 24 h under SVS (p<0.000001). Conclusions: Our findings support the need for patient assessment under SVS at 24 h after ARDS onset to assess disease severity, and have implications for the diagnosis and management of ARDS patients. Trial registration numbers NCT00435110 and NCT00736892

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
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