851 research outputs found

    COMPOSITION AND ANIMAL PREFERENCE FOR PLANTS USED FOR GOAT FEEDING IN SEMIARID NORTHEASTERN MEXICO

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    ABSTRACT Arid and semiarid zones of Northeastern Mexico are characterized as regions with high variation in their climatic conditions but rich in drought-tolerant botanical species which are potentially useful for grazing and pastoral activities. Feeding habits and voluntary intake from a total of 100 grazing goats were determined through identification of the plants that make up their diet, their availability in the rangeland, preference index, browsing height and their chemical composition during a 10-month growing period. Four heights of browsing were determined in the different vegetative strata. Climatic factors were determinant in the height of grazing and the availability of forage. Shrub species constituted 78% of the animal diet during the growing season followed by herbs (12-18%) and grasses (6-10%). The species with higher index of preference offered high availability in the rangeland with proper content of crude protein (10.7-24%), crude fiber (12.2-24.5%), cellulose (5.9-20.6%) and nitrogen free extract (30.2-50.6%). These results indicate that in seasons of high feed availability the intake of most preferred shrubs is taking place most of the time at a browsing height between 80 and 120 cm with species rich enough in nutrients to satisfy their minimum daily protein and fiber requirements. [¿Y que ónda con aquello de que cuando hay muchas hierbas abajo prefieren comer esas hierbas?]Thus, the pasture conditions, climate and the availability of the vegetation in a given season are crucial factors for suitable livestock management

    Diversidad de macromicetos en bosques de pino en el municipio Madera, Chihuahua

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    El municipio Madera cuenta con una gran diversidad de ecosistemas que albergan una alta riqueza de especies fúngicas, de las cuales se tiene poco conocimiento debido a la falta de investigación para esa zona. El objetivo del presente estudio fue determinar y comparar la diversidad, hábitos y comestibilidad de los macromicetos. El muestreo se realizó en siete parcelas de 100 m × 100 m, en seis ejidos del municipio Madera, Chihuahua, durante los meses de julio y agosto del año 2016; se determinó número efectivo de especies, abundancia de frutos y diversidad alfa, mediante los índices de Shannon (Hˈ) y Margalef (DMG). Los resultados mostraron un total de 69 taxa de macromicetos, pertenecientes a 27 familias y 46 géneros; de acuerdo al hábito de desarrollo, 53.62 % son saprobias, 43.50 % micorrízicas y 2.90 % patógenas. En cuanto a la comestibilidad, 28.98 % tienen potencial alimenticio. La mayor diversidad se presentó en el ejido Socorro Rivera (H’=2.44 y DMG=3.58). Las especies con mayor distribución en las localidades de estudio pertenecen a Amanita; el porcentaje más alto de similitud de especies se registró en los ejidos Nicolás Bravo (paraje El Pedregoso) y Madera, con 18 %. Los taxones fúngicos registrados se suman a los citados previamente; con ello, aumenta el conocimiento para el estado de Chihuahua

    VOLUMEN 22, NÚMERO 37 (2000)

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    ANÁLISIS DE VARIABLES MORFOMÉTRICAS DE toxaster roulini agassiz (Echinoides: toxasteriidae) DE LA FORMACIÓN ROSA BLANCA, MUNICIPIO DE ZAPATOCA (SANTANDER, COLOMBIA). Cruz Guevara, L. E.; Jerez Jaimes, J. H., Narváez Parra, E. X.; Franco Blanco, R. A.COMPOSICIÓN QUÍMICA Y MINERALOGÍA DE LAS BIOTITAS METAMÓRFICAS DEL SECTOR CENTRAL DEL MACIZO DE SANTANDER, COLOMBIA. García Ramírez, C. A.; Campos Álvarez, N. O.BRECHAS DE ATRICIÓN Y MINERALIZACIONES AURÍFERAS EN LAS MINAS DE MIRAFLORES (QUINCHÍA, RISARALDA) Y SU RELACIÓN CON UN CUERPO TIPO “BRECHA - PIPE”. Carrillo Lombana, V. M.CRITERIOS PARA LA CLASIFICACIÓN Y DESCRIPCIÓN DE MOVIMIENTOS EN MASA. Vargas Cuervo, G.ANOMALÍAS GEOBOTÁNICAS ESPECTRALES ASOCIADAS CON LOS CAMBIOS EN LITOLOGÍA: SU USO PARA LA CARTOGRAFÍA GEOLÓGICA DE ROCAS ULTRABÁSICAS, EN TERRENOS TOTALMENTE VEGETADOS DE LA COSTA PACÍFICA COLOMBIANA. Villegas, V. H

    VOLUMEN 22, NÚMERO 37 (2000)

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    ANÁLISIS DE VARIABLES MORFOMÉTRICAS DE toxaster roulini agassiz (Echinoides: toxasteriidae) DE LA FORMACIÓN ROSA BLANCA, MUNICIPIO DE ZAPATOCA (SANTANDER, COLOMBIA). Cruz Guevara, L. E.; Jerez Jaimes, J. H., Narváez Parra, E. X.; Franco Blanco, R. A.COMPOSICIÓN QUÍMICA Y MINERALOGÍA DE LAS BIOTITAS METAMÓRFICAS DEL SECTOR CENTRAL DEL MACIZO DE SANTANDER, COLOMBIA. García Ramírez, C. A.; Campos Álvarez, N. O.BRECHAS DE ATRICIÓN Y MINERALIZACIONES AURÍFERAS EN LAS MINAS DE MIRAFLORES (QUINCHÍA, RISARALDA) Y SU RELACIÓN CON UN CUERPO TIPO “BRECHA - PIPE”. Carrillo Lombana, V. M.CRITERIOS PARA LA CLASIFICACIÓN Y DESCRIPCIÓN DE MOVIMIENTOS EN MASA. Vargas Cuervo, G.ANOMALÍAS GEOBOTÁNICAS ESPECTRALES ASOCIADAS CON LOS CAMBIOS EN LITOLOGÍA: SU USO PARA LA CARTOGRAFÍA GEOLÓGICA DE ROCAS ULTRABÁSICAS, EN TERRENOS TOTALMENTE VEGETADOS DE LA COSTA PACÍFICA COLOMBIANA. Villegas, V. H

    Relationship of metabolic syndrome and its components with -844 G/A and HindIII C/G PAI-1 gene polymorphisms in Mexican children

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    <p>Abstract</p> <p>Background</p> <p>Several association studies have shown that -844 G/A and <it>HindIII </it>C/G <it>PAI-1 </it>polymorphisms are related with increase of PAI-1 levels, obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, which are components of metabolic syndrome. The aim of this study was to analyze the allele and genotype frequencies of these polymorphisms in <it>PAI-1 </it>gene and its association with metabolic syndrome and its components in a sample of Mexican mestizo children.</p> <p>Methods</p> <p>This study included 100 children with an age range between 6-11 years divided in two groups: a) 48 children diagnosed with metabolic syndrome and b) 52 children metabolically healthy without any clinical and biochemical alteration. Metabolic syndrome was defined as the presence of three or more of the following criteria: fasting glucose levels ≥ 100 mg/dL, triglycerides ≥ 150 mg/dL, HDL-cholesterol < 40 mg/dL, obesity BMI ≥ 95<sup>th </sup>percentile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) ≥ 95<sup>th </sup>percentile and insulin resistance HOMA-IR ≥ 2.4. The -844 G/A and <it>HindIII </it>C/G <it>PAI-1 </it>polymorphisms were analyzed by PCR-RFLP.</p> <p>Results</p> <p>For the -844 G/A polymorphism, the G/A genotype (OR = 2.79; 95% CI, 1.11-7.08; <it>p </it>= 0.015) and the A allele (OR = 2.2; 95% CI, 1.10-4.43; <it>p </it>= 0.015) were associated with metabolic syndrome. The -844 G/A and A/A genotypes were associated with increase in plasma triglycerides levels (OR = 2.6; 95% CI, 1.16 to 6.04; <it>p </it>= 0.02), decrease in plasma HDL-cholesterol levels (OR = 2.4; 95% CI, 1.06 to 5.42; <it>p </it>= 0.03) and obesity (OR = 2.6; 95% CI, 1.17-5.92; <it>p </it>= 0.01). The C/G and G/G genotypes of the <it>HindIII </it>C/G polymorphism contributed to a significant increase in plasma total cholesterol levels (179 vs. 165 mg/dL; <it>p </it>= 0.02) in comparison with C/C genotype.</p> <p>Conclusions</p> <p>The -844 G/A <it>PAI-1 </it>polymorphism is related with the risk of developing metabolic syndrome, obesity and atherogenic dyslipidemia, and the <it>HindIII </it>C/G <it>PAI-1 </it>polymorphism was associated with the increase of total cholesterol levels in Mexican children.</p

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

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    Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model
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