476 research outputs found

    Descripción del nido de Phyllotis andium (Cricetidae: Phyllotini), en un matorral seco interandino en Ecuador

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    In this work, we describe the structure of the nest of Phyllotis andium Thomas, 1912 in an inter-Andean dry scrub in the south of the Azuay province in Ecuador, and the use of an introduced grass in their manufacture. Observations on sociability and abundance of this species are also presented. These data provide new information on the intraspecific relationships of these rodents and their natural history.En este trabajo describimos la estructura del nido de Phyllotis andium Thomas, 1912 en un matorral seco interandino al sur de la provincia del Azuay en Ecuador y el uso de un pasto introducido en su fabricación. Se presentan también observaciones sobre sociabilidad y abundancia de esta especie. Estos datos proporcionan nueva información sobre las relaciones intraespecíficas de estos roedores y su historia natural

    Situación actual del recurso suelo en México y la incorporación de abonos orgánicos como estrategia para su conservación

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    Los suelos sufren una creciente degradación por la intensificación de su uso en las diversas actividades productivas. Algunos de los problemas más importantes que actualmente enfrenta la agricultura en general son la erosión y la pérdida de fertilidad de los suelos, por lo que las medidas preventivas, como la implementación de buenas prácticas de manejo del suelo, son esenciales para revertir su tendencia a la degradación, y con ello garantizar la seguridad alimentaria y proteger la prestación de los diferentes servicios ecosistémicos asociados al suelo. Tradicionalmente, residuos orgánicos han sido incorporados a suelos agrícolas para aumentar el contenido de materia orgánica y como fuente de nitrógeno para los cultivos. Sin embargo, frecuentemente esta aplicación no es realizada en forma adecuada, atendiendo a las características del suelo y al estado de descomposición de los residuos orgánicos, lo que puede provocar una serie de daños en la salud del ecosistema, como la salinización de los suelos, la lixiviación de sustancias fitotóxicas y el escurrimiento de nitratos y fosfatos a mantos acuíferos y a cuerpos de agua superficiales. Una alternativa para la disminución del impacto ambiental del uso de estos desechos son el semicompostaje, compostaje y el vermicompostaje, procesos que permiten la producción de materiales de interés agrícola y de comercialización viable: la semicomposta, la composta y la vermicomposta, productos estables que pueden tener diversas aplicaciones de interés agrícola como abonos, enmiendas y sustratos orgánicos. La incorporación de dichos abonos orgánicos es una práctica que está cobrando cada vez más importancia por sus comprobados efectos benéficos en las propiedades físicas, químicas y biológicas de los suelos agrícolas

    Phylogenetic position of “Cochranella” megista (Anura: Centrolenidae) and first records for Ecuador

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    “Cochranella” megista is an Endangered and rarely encountered species of glass frog that, until now, had been only registered in the Colombian Andes. Here we report this species for the first time in Ecuador, expanding its known distribution ca. 530 km south of its original range. Additionally, we include C. megista in a molecular phylogeny for the first time and unambiguously place the species in the genus Nymphargus, resulting in a new combination. Habitat in both countries is fragmented and is threatened by mining concessions and agriculture

    Design proposal of a Maintenance Management System for the Company Pesquera Pacasmayo E.I.R.L.

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    The purpose of this research is to implement preventive maintenance using the tools of: Predictive Maintenance and Total Productive Maintenance (TPM) in the company Pesquera Pacasmayo E.I.R.L.; since, after identifying the constant problems in the production area, it was identified that the main causes of these problems arise from deficiencies in maintenance. The study has a pre-experimental design, in which data collection techniques and instruments were used, specifically in the analysis of information on the company's production and maintenance processes. First, a diagnosis of these areas was carried out to identify the problems that directly affect productivity, in order to determine the maintenance tools to apply; then, the Mean Time Between Failures was found, considering the work data in real time and the number of failures, finding the value of 40 hours for the main machine, 70.94 hours for the hydraulic generator and 54.36 hours for the refrigeration compressor; Average Time Between Repairs, considering the data on the downtime due to breakdown and the number of breakdowns, where the value of 5 hours was found for the main machine, 3.5 hours for the hydraulic generator, and 4 hours for the refrigeration compressor. Regarding availability, 89% was found for the main machine, 95% for hydraulic generators and 93% for refrigeration compressors. Similarly, preventive maintenance was applied to minimize these problems. Total Productive Maintenance (TPM) was also applied, where an increase in productivity is reflected; as well as, an increase of the Total Effectiveness of the team to 15%

    Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

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    BACKGROUND: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration. METHODS: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets. FINDINGS: Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990. INTERPRETATION: Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action. FUNDING: Bill & Melinda Gates Foundation

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

    Study of the BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

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    The decay BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} is studied in proton-proton collisions at a center-of-mass energy of s=13\sqrt{s}=13 TeV using data corresponding to an integrated luminosity of 5 fb1\mathrm{fb}^{-1} collected by the LHCb experiment. In the Λc+K\Lambda_{c}^+ K^{-} system, the Ξc(2930)0\Xi_{c}(2930)^{0} state observed at the BaBar and Belle experiments is resolved into two narrower states, Ξc(2923)0\Xi_{c}(2923)^{0} and Ξc(2939)0\Xi_{c}(2939)^{0}, whose masses and widths are measured to be m(Ξc(2923)0)=2924.5±0.4±1.1MeV,m(Ξc(2939)0)=2938.5±0.9±2.3MeV,Γ(Ξc(2923)0)=0004.8±0.9±1.5MeV,Γ(Ξc(2939)0)=0011.0±1.9±7.5MeV, m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV}, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt Λc+K\Lambda_{c}^{+} K^{-} sample. Evidence of a new Ξc(2880)0\Xi_{c}(2880)^{0} state is found with a local significance of 3.8σ3.8\,\sigma, whose mass and width are measured to be 2881.8±3.1±8.5MeV2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV} and 12.4±5.3±5.8MeV12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}, respectively. In addition, evidence of a new decay mode Ξc(2790)0Λc+K\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-} is found with a significance of 3.7σ3.7\,\sigma. The relative branching fraction of BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} with respect to the BD+DKB^{-} \to D^{+} D^{-} K^{-} decay is measured to be 2.36±0.11±0.22±0.252.36 \pm 0.11 \pm 0.22 \pm 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

    Measurement of the ratios of branching fractions R(D)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

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    The ratios of branching fractions R(D)B(BˉDτνˉτ)/B(BˉDμνˉμ)\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu}) and R(D0)B(BD0τνˉτ)/B(BD0μνˉμ)\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu}) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb1{ }^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τμντνˉμ\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}. The measured values are R(D)=0.281±0.018±0.024\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024 and R(D0)=0.441±0.060±0.066\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=0.43\rho=-0.43. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

    Antibodies against endogenous retroviruses promote lung cancer immunotherapy

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    B cells are frequently found in the margins of solid tumours as organized follicles in ectopic lymphoid organs called tertiary lymphoid structures (TLS). Although TLS have been found to correlate with improved patient survival and response to immune checkpoint blockade (ICB), the underlying mechanisms of this association remain elusive. Here we investigate lung-resident B cell responses in patients from the TRACERx 421 (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy) and other lung cancer cohorts, and in a recently established immunogenic mouse model for lung adenocarcinoma. We find that both human and mouse lung adenocarcinomas elicit local germinal centre responses and tumour-binding antibodies, and further identify endogenous retrovirus (ERV) envelope glycoproteins as a dominant anti-tumour antibody target. ERV-targeting B cell responses are amplified by ICB in both humans and mice, and by targeted inhibition of KRAS(G12C) in the mouse model. ERV-reactive antibodies exert anti-tumour activity that extends survival in the mouse model, and ERV expression predicts the outcome of ICB in human lung adenocarcinoma. Finally, we find that effective immunotherapy in the mouse model requires CXCL13-dependent TLS formation. Conversely, therapeutic CXCL13 treatment potentiates anti-tumour immunity and synergizes with ICB. Our findings provide a possible mechanistic basis for the association of TLS with immunotherapy response

    Phylogenetic position of “Cochranella” megista (Anura: Centrolenidae) and first records for Ecuador

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    “Cochranella”&nbsp;megista é uma perereca-de-vidro ameaçada e raramente encontrada, que até o momento só havia sido registrada nos Andes colombianos. Relatamos aqui a presença dessa espécie pela primeira vez no Equador, expandindo sua distribuição conhecida para cerca de 530 km ao sul&nbsp;de sua área de distribuição original. Adicionalmente, incluímos C. megista em uma filogenia molecular pela primeira vez e alocamos inequivocamente a espécie no gênero Nymphargus, resultando em uma nova combinação. O habitat em ambos os países é fragmentado e está ameaçado pelas concessões mineiras e pela agricultura.“Cochranella” megista&nbsp;is an Endangered and rarely encountered species of glass frog that, until now, had been only registered in the Colombian Andes. Here we report this species for the first time in Ecuador, expanding its known distribution ca. 530 km south of its original range. Additionally, we include C. megista in a molecular phylogeny for the first time and unambiguously place the species in the genus Nymphargus, resulting in a new combination. Habitat in both countries is fragmented and is threatened by mining concessions and agriculture
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