240 research outputs found
Diversidad de micorrizas arbusculares en agroecositemas de pastura del departamento de sucre
The objective of this study was to compare the diversity of arbuscular mycorrhizae associated colosoana grass (Bothriochloa pertusa (L) A. Camus) and angletón (Dichanthium aristatum, Benth) present in livestock farms in the municipalities of Corozal and Tolú, Department of Sucre, Colombia. Was determined density esporas/100gr soil and roots percentage of colonization in both species of grass. From the isolated morphotypes proceeded to the species identification using taxonomic keys. The results of analysis of variance for density g of soil spores/100 show highly significant difference between pasture and locality. The highest density of spores found was 1160 ± 6233 and 2643 ± 444 g soil spores/100 respectively for colosoana and angleton in the municipalities of Corozal and Tolú. The percentage of colonization showed highly significant difference between pasture and locality. The Tukey test showed highly significant difference between the percentage of colonization for colosoana and angleton in the municipalities of Corozal and Tolú. A total of 32 morphotypes were isolated MA, 15 for Corozal and the rest in the Tolú. There is a high diversity of MA associated with these two pastures in different edaphoclimatic conditions, the department but there are still studies to predict dispersal patterns and location of these specific agroecosystems mycorrhizae in pastures in the department of Sucre.El objetivo del presente estudio fue comparar la diversidad de micorrizas arbusculares asociadas al pasto colosoana (Bothriochloa pertusa (L) A. Camus) y angletón (Dichanthium aristatum, Benth) presentes en fincas ganaderas de los municipios de Corozal y Tolú, Departamento de Sucre, Colombia. Se determinó la densidad de esporas/100gr suelo y el porcentaje de infección en raíces en ambas especies de pasto. A partir de los morfotipos aislados se procedió a la identificación de especies de MA, utilizando claves taxonómicas. Los resultados del análisis de varianza para densidad de esporas/100 g de suelo de muestran diferencia altamente significativa entre pasturas y localidad. La mayor densidad de esporas encontrada fue de 1160 ± 6233 y 444 ± 2643 esporas/100 g de suelo, respectivamente para colosoana y angletón en el municipio de Corozal. EL porcentaje de colonización mostró diferencia altamente significativa entre pastura y localidad. La prueba de Tukey mostró diferencia altamente significativa entre el porcentaje de colonización para la especie colosoana y angletón en los municipios de Corozal y de Tolú. Un total de 32 morfotipos MA fueron aislados, 15 para el municipio de Corozal y el resto en el municipio de Tolú. Existe una alta diversidad de MA asociadas a estas dos pasturas en condiciones edafoclimaticas diferentes, del departamento pero aún faltan estudios que permita predecir los patrones de dispersión y localización de estas micorrizas en agroecosistemas específicos de pasturas en el departamento de Sucre
Mortalidad y estancia hospitalaria relacionada con trauma ocupacional atendido durante el fin de semana en el servicio de emergencias.
Objetivo. Los desenlaces del trauma ocupacional agudo (TOA) puede estar condicionado al desarrollo industrial y al momento de la semana de ocurrencia; se comparó la mortalidad y estancia hospitalaria (EH) de trabajadores que presentaron TOA en diferentes momentos de la semana.
Métodos. Con un estudio descriptivo retrospectivo y utilizando los datos de una base de datos administrativa de trabajadores atendidos por TOA, entre enero/2007-diciembre/2010, en una Clínica de III nivel en Bogotá, se comparó la mediana de EH y el riesgo de mortalidad (OR; IC95%) en pacientes atendidos por TOA entre semana (ES) y en fin de semana (FdS); la frecuencia de eventos fue ponderada (p) por los días ES-p (4 días) y FdS-p (3 días).
Resultados. Se evaluaron 65.169 registros médicos, en FdS-p y en ES-p ocurrieron 4295 y 13071 TOA, respectivamente; los TOA predominaron en hombres, adultos-jóvenes (edad mediana 30-33 años). La mediana de EH ES fue 0,43 horas y en FdS 0,48 horas (p: 0,000). Los TOA ocurridos en trabajadores de 45-64 años (3,47;1.76-6,76), atendidos en la noche (3,27;1,64-6,40), en FdS (4,57;1,25-18,4) y en noche-FdS (4,49;1,64-14,0) presentaron el riesgo más elevado de mortalidad.
Conclusión. Los trabajadores atendidos por TOA durante el fin de semana tienen mayor EH, riesgo de muerte y baja frecuencia de atenciones por Medicina Especializada. Los protocolos institucionales de atención por TOA podrían contemplar este efecto, para brindar atenciones seguras y equitativas, independiente del momento de atención
Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results
The chromosphere is a thin layer of the solar atmosphere that bridges the
relatively cool photosphere and the intensely heated transition region and
corona. Compressible and incompressible waves propagating through the
chromosphere can supply significant amounts of energy to the interface region
and corona. In recent years an abundance of high-resolution observations from
state-of-the-art facilities have provided new and exciting ways of
disentangling the characteristics of oscillatory phenomena propagating through
the dynamic chromosphere. Coupled with rapid advancements in
magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly
investigate the role waves play in supplying energy to sustain chromospheric
and coronal heating. Here, we review the recent progress made in
characterising, categorising and interpreting oscillations manifesting in the
solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review
Chronoamperometric Study of Ammonia Oxidation in a Direct Ammonia Alkaline Fuel Cell under the Influence of Microgravity
This is a study of the chronoamperometric performance of the electrochemical oxidation of ammonia in an alkaline fuel cell for space applications. Under microgravity the performance of a fuel cell is diminished by the absence of buoyancy since nitrogen gas is produced. The following catalysts were studied: platinum nanocubes of ca. 10nm, platinum nanocubes on carbon Vulcan ™ and platinum on carbon nanoonion support of ca. 10nm. These nanomaterials were studied in order to search for catalysts that may reduce or counter the loss of ammonia oxidation current densities performance under microgravity conditions. Chronoamperometries at potential values ranging from 0.2 V to 1.2V vs. cathode potential (breathing Air/300ml/min/82737 Pa) in 1.0 M NH4OH (30ml/min in anode) were done during over 30 parabolas in NASA’s C9 airplane The Weightless Wonder in January 2016 from Ellington Field Houston. The current densities at 15s in the chronoamperometry experiments showed diminishing values under microgravity and in some cases improvements of up to 92%, for Pt-carbon nanoonions, and over 70% for the three catalysts versus ground at potentials ranging from 0.2 to 0.4V after 5 minutes of chronoamperometric conditions. At higher potentials, 1.0V or higher, Pt nanocubes and Pt-carbon nanoonions showed enhancements of up to 32% and 24%, respectively. At these higher potentials we will have a contribution of oxygen evolution. The changes in current behavior are attributed to the sizes of the catalyst materials and the time needed for the N2 bubbles detachment from the Pt surface under microgravity conditions.This work was financially supported by the NASA-MIRO Center for Advanced Nanoscale Materials at the University of Puerto Rico-Río Piedras Campus Grant number NNX10AQ17A and NASA-EPSCoR grant number NNX14AN18A, Puerto Rico NASA Space Grant Consortium: NASA cooperative agreement NNX10AM80H, NASA Flight Opportunities Program Announcement of Flight Opportunities (AFO) NOCT110 call #5 and Ministerio de Economía y Competitividad (projects CTQ2013-44083-P and CTQ2013-48280-C3-3-R)
Substituting abacavir for hyperlipidemia-associated protease inhibitors in HAART regimens improves fasting lipid profiles, maintains virologic suppression, and simplifies treatment
BACKGROUND: Hyperlipidemia secondary to protease inhibitors (PI) may abate by switching to anti-HIV medications without lipid effects. METHOD: An open-label, randomized pilot study compared changes in fasting lipids and HIV-1 RNA in 104 HIV-infected adults with PI-associated hyperlipidemia (fasting serum total cholesterol >200 mg/dL) who were randomized either to a regimen in which their PI was replaced by abacavir 300 mg twice daily (n = 52) or a regimen in which their PI was continued (n = 52) for 28 weeks. All patients had undetectable viral loads (HIV-1 RNA <50 copies/mL) at baseline and were naïve to abacavir and non-nucleoside reverse transcriptase inhibitors. RESULTS: At baseline, the mean total cholesterol was 243 mg/dL, low density lipoprotein (LDL)-cholesterol 149 mg/dL, high density lipoprotein (HDL)-cholesterol 41 mg/dL, and triglycerides 310 mg/dL. Mean CD4+ cell counts were 551 and 531 cells/mm(3 )in the abacavir-switch and PI-continuation arms, respectively. At week 28, the abacavir-switch arm had significantly greater least square mean reduction from baseline in total cholesterol (-42 vs -10 mg/dL, P < 0.001), LDL-cholesterol (-14 vs +5 mg/dL, P = 0.016), and triglycerides (-134 vs -36 mg/dL, P = 0.019) than the PI-continuation arm, with no differences in HDL-cholesterol (+0.2 vs +1.3 mg/dL, P = 0.583). A higher proportion of patients in the abacavir-switch arm had decreases in protocol-defined total cholesterol and triglyceride toxicity grades, whereas a smaller proportion had increases in these toxicity grades. At week 28, an intent-to treat: missing = failure analysis showed that the abacavir-switch and PI-continuation arms did not differ significantly with respect to proportion of patients maintaining HIV-1 RNA <400 or <50 copies/mL or adjusted mean change from baseline in CD4+ cell count. Two possible abacavir-related hypersensitivity reactions were reported. No significant changes in glucose, insulin, insulin resistance, C-peptide, or waist-to-hip ratios were observed in either treatment arm, nor were differences in these parameters noted between treatments. CONCLUSION: In hyperlipidemic, antiretroviral-experienced patients with HIV-1 RNA levels <50 copies/mL and CD4+ cell counts >500 cells/mm(3), substituting abacavir for hyperlipidemia-associated PIs in combination antiretroviral regimens improves lipid profiles and maintains virologic suppression over a 28-week period, and it simplifies treatment
Diversity, distribution and conservation of the terrestrial reptiles of Oman (Sauropsida, Squamata)
All authors:
Salvador Carranza ,
Meritxell Xipell,
Pedro Tarroso,
Andrew Gardner,
Edwin Nicholas Arnold,
Michael D. Robinson,
Marc Simó-Riudalbas,
Raquel Vasconcelos,
Philip de Pous,
Fèlix Amat,
Jiří Šmíd,
Roberto Sindaco,
Margarita Metallinou †,
Johannes Els,
Juan Manuel Pleguezuelos,
Luis Machado,
David Donaire,
Gabriel Martínez,
Joan Garcia-Porta,
Tomáš Mazuch,
Thomas Wilms,
Jürgen Gebhart,
Javier Aznar,
Javier Gallego,
Bernd-Michael Zwanzig,
Daniel Fernández-Guiberteau,
Theodore Papenfuss,
Saleh Al Saadi,
Ali Alghafri,
Sultan Khalifa,
Hamed Al Farqani,
Salim Bait Bilal,
Iman Sulaiman Alazri,
Aziza Saud Al Adhoobi,
Zeyana Salim Al Omairi,
Mohammed Al Shariani,
Ali Al Kiyumi,
Thuraya Al Sariri,
Ahmed Said Al Shukaili,
Suleiman Nasser Al Akhzami.In the present work, we use an exceptional database including 5,359 records of 101 species of Oman’s terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman’s 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).This work was funded by grants CGL2012-36970, CGL2015-70390-P from the Ministerio de Economía y Competitividad, Spain (cofunded by FEDER) to SC, the project Field study for the conservation of reptiles in Oman, Ministry of Environment and Climate Affairs, Oman (Ref: 22412027) to SC and grant 2014-SGR-1532 from the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya to SC. MSR is funded by a FPI grant from the Ministerio de Economía y Competitividad, Spain (BES-2013-064248); RV, PT and LM were funded by Fundação para a Ciência e Tecnologia (FCT) through post-doc grants (SFRH/BPD/79913/2011) to RV, (SFRH/BPD/93473/2013) to PT and PhD grant (SFRH/BD/89820/2012) to LM, financed by Programa Operacional Potencial Humano (POPH) – Quadro de Referência Estrategico Nacional (QREN) from the European Social Fund and Portuguese Ministerio da Educação e Ciência
An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance.
RESULTS:
A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization.
CONCLUSIONS:
The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups
Design, Performance and Calibration of the CMS Forward Calorimeter Wedges
We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%
Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter
The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS
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