1,225 research outputs found
Combustión de carbones en un lecho fluidizado
El presente trabajo experimental involucra la determinación de algunos parámetros que caracterizan la combustión de partículas de carbón en un lecho fluidizado, utilizando caliza o dolomita para controlar la emisión de azufre. La parte principal del equipo, la columna de fluidización, fue construida de cemento refractario de 10.5 cm. de diámetro y 85 cm. de altura. Los resultados experimentales para la velocidad mínima de fluidización fueron similares a los calculados con la ecuación de Babu2. Se observaron fu ertes variaciones de la temperatura con la velocidad del aire, contenido muy bajo de CO en los gases de combustión, estabilidad en la temperatura para un conjunto de parámetros y una retención de azufre menor que los valores publicados
Perturbation biology: inferring signaling networks in cellular systems.
We present a powerful experimental-computational technology for inferring network models that predict the response of cells to perturbations, and that may be useful in the design of combinatorial therapy against cancer. The experiments are systematic series of perturbations of cancer cell lines by targeted drugs, singly or in combination. The response to perturbation is quantified in terms of relative changes in the measured levels of proteins, phospho-proteins and cellular phenotypes such as viability. Computational network models are derived de novo, i.e., without prior knowledge of signaling pathways, and are based on simple non-linear differential equations. The prohibitively large solution space of all possible network models is explored efficiently using a probabilistic algorithm, Belief Propagation (BP), which is three orders of magnitude faster than standard Monte Carlo methods. Explicit executable models are derived for a set of perturbation experiments in SKMEL-133 melanoma cell lines, which are resistant to the therapeutically important inhibitor of RAF kinase. The resulting network models reproduce and extend known pathway biology. They empower potential discoveries of new molecular interactions and predict efficacious novel drug perturbations, such as the inhibition of PLK1, which is verified experimentally. This technology is suitable for application to larger systems in diverse areas of molecular biology
Actividad anti fúngica (in vitro) de extractos vegetales para el control de antracnosis (Colletotrichum acutatum)
The antifungal effect of five plant extracts: nettle (Urtica dioica), chamomile (Chamaemelum nobile), frame (Artemisiavulgaris), lavender (Lavandula officinalis) and chamico (Datura ferox) were evaluated at laboratory level for control ofanthracnose (Colletotrichum acutatum) of the tree tomato (Solanum betaceum), using two methods of extraction (maceration and steam trapping), in the results obtained, statistical differences were observed in the percentage of inhibition ofmycelial growth of the fungus, the treatment with lavender extract obtained by the steam trapping method presented thegreatest efficiency for anthracnose control (66.23%). The other treatments tested also showed effectiveness against theanthracnose pathogen in the following order of inhibition: chamomile (52.78%), frame (21.63), chamico (24.14%), nettle(12.94), the ability of various species to inhibit certain fungal diseases, taking into account the different content of secondary metabolites that have each of the plant species, constituting new clean production alternatives that reduce the useof chemical pesticides for the control of fungal diseases.Se evaluó el efecto anti fúngico de la aplicación de cinco extractos vegetales: ortiga (Urtica dioica), manzanilla (Chamaemelum nobile), marco (Artemisia vulgaris), lavanda (Lavandula officinalis) y chamico (Datura ferox), a nivel delaboratorio para control de antracnosis (Colletotrichum acutatum) del tomate de árbol (Solanum betaceum), utilizandodos métodos de extracción (maceración y arrastre de vapor), en los resultados obtenidos, se observa diferencias estadística en el porcentaje de inhibición de crecimiento micelial del hongo, el tratamiento con extracto de lavanda obtenido porel método de arrastre de vapor, presentó la mayor eficacia para control de antracnosis (66.23%). Los demás tratamientosensayados también presentó actividad contra el patógeno de la antracnosis, en el siguiente orden de inhibición: manzanilla (52.78 %), marco (21.63), chamico (24.14 %), ortiga (12.94), la capacidad de diversas especies de inhibir ciertasenfermedades fúngicas, asumiéndose al contenido diferente de metabolitos secundarios que tienen cada una de las especies vegetales, constituyendo en una alternativa de producción limpia, que reduzcan la utilización de pesticidas químicospara el control de las enfermedades fúngicas
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
New effects during steam gasification of naphthalene: the synergy between CaO and MgO during the catalytic reaction
Stillbirths: recall to action in high-income countries.
Variation in stillbirth rates across high-income countries and large equity gaps within high-income countries persist. If all high-income countries achieved stillbirth rates equal to the best performing countries, 19,439 late gestation (28 weeks or more) stillbirths could have been avoided in 2015. The proportion of unexplained stillbirths is high and can be addressed through improvements in data collection, investigation, and classification, and with a better understanding of causal pathways. Substandard care contributes to 20-30% of all stillbirths and the contribution is even higher for late gestation intrapartum stillbirths. National perinatal mortality audit programmes need to be implemented in all high-income countries. The need to reduce stigma and fatalism related to stillbirth and to improve bereavement care are also clear, persisting priorities for action. In high-income countries, a woman living under adverse socioeconomic circumstances has twice the risk of having a stillborn child when compared to her more advantaged counterparts. Programmes at community and country level need to improve health in disadvantaged families to address these inequities.Mater Research Institute – The University of Queensland provided infrastructure and funding for the research team to enable this work to be undertaken. The Canadian Research Chair in Psychosocial Family Health provided funding for revision of the translation of the French web-based survey of care providers.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/S0140-6736(15)01020-
Four-Year Treatment Outcomes of Adult Patients Enrolled in Mozambique's Rapidly Expanding Antiretroviral Therapy Program
BACKGROUND: In Mozambique during 2004-2007 numbers of adult patients (≥15 years old) enrolled on antiretroviral therapy (ART) increased about 16-fold, from <5,000 to 79,500. All ART patients were eligible for co-trimoxazole. ART program outcomes, and determinants of outcomes, have not yet been reported. METHODOLOGY/PRINCIPAL FINDINGS: In a retrospective cohort study, we investigated rates of mortality, attrition (death, loss to follow-up, or treatment cessation), immunologic treatment failure, and regimen-switch, as well as determinants of selected outcomes, among a nationally representative sample of 2,596 adults initiating ART during 2004-2007. At ART initiation, median age of patients was 34 and 62% were female. Malnutrition and advanced disease were common; 18% of patients weighed <45 kilograms, and 15% were WHO stage IV. Median baseline CD4(+) T-cell count was 153/µL and was lower for males than females (139/µL vs. 159/µL, p<0.01). Stavudine, lamivudine, and nevirapine or efavirenz were prescribed to 88% of patients; only 31% were prescribed co-trimoxazole. Mortality and attrition rates were 3.4 deaths and 19.8 attritions per 100 patient-years overall, and 12.9 deaths and 57.2 attritions per 100 patient-years in the first 90 days. Predictors of attrition included male sex [adjusted hazard ratio (AHR) 1.5; 95% confidence interval (CI), 1.3-1.8], weight <45 kg (AHR 2.1; 95% CI, 1.6-2.9, reference group >60 kg), WHO stage IV (AHR 1.7; 95% CI, 1.3-2.4, reference group WHO stage I/II), lack of co-trimoxazole prescription (AHR 1.4; 95% CI, 1.0-1.8), and later calendar year of ART initiation (AHR 1.5; 95% CI, 1.2-1.8). Rates of immunologic treatment failure and regimen-switch were 14.0 and 0.6 events per 100-patient years, respectively. CONCLUSIONS: ART initiation at earlier disease stages and scale-up of co-trimoxazole among ART patients could improve outcomes. Research to determine reasons for low regimen-switch rates and increasing rates of attrition during program expansion is needed
Cryptic Speciation in Brazilian Epiperipatus (Onychophora: Peripatidae) Reveals an Underestimated Diversity among the Peripatid Velvet Worms
Taxonomical studies of the neotropical Peripatidae (Onychophora, velvet worms) have proven difficult, due to intraspecific variation and uniformity of morphological characters across this onychophoran subgroup. We therefore used molecular approaches, in addition to morphological methods, to explore the diversity of Epiperipatus from the Minas Gerais State of Brazil.Our analyses revealed three new species. While Epiperipatus diadenoproctussp. nov. can be distinguished from E. adenocryptussp. nov. and E. paurognostussp. nov. based on morphology and specific nucleotide positions in the mitochondrial cytochrome c oxidase subunit I (COI) and small ribosomal subunit RNA gene sequences (12S rRNA), anatomical differences between the two latter species are not evident. However, our phylogenetic analyses of molecular data suggest that they are cryptic species, with high Bayesian posterior probabilities and bootstrap and Bremer support values for each species clade. The sister group relationship of E. adenocryptussp. nov. and E. paurognostussp. nov. in our analyses correlates with the remarkable morphological similarity of these two species. To assess the species status of the new species, we performed a statistical parsimony network analysis based on 582 base pairs of the COI gene in our specimens, with the connection probability set to 95%. Our findings revealed no connections between groups of haplotypes, which have been recognized as allopatric lineages in our phylogenetic analyses, thus supporting our suggestion that they are separate species.Our findings suggest high cryptic species diversity and endemism among the neotropical Peripatidae and demonstrate that the combination of morphological and molecular approaches is helpful for clarifying the taxonomy and species diversity of this apparently large and diverse onychophoran group
Fine root biomass and root length density in a lowland and a montane tropical rain forest, SP, Brazil
- …