4,133 research outputs found

    Local cohomology and Lyubeznik numbers of F-pure rings

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    In this article, we study certain local cohomology modules over F-pure rings. We give sufficient conditions for the vanishing of some Lyubeznik numbers, derive a formula for computing these invariants when the F-pure ring is standard graded and, by its means, we provide some new examples of Lyubeznik tables. We study associated primes of certain Ext-modules, showing that they are all compatible ideals. Finally, we focus on properties that Lyubeznik numbers detect over a globally F-split projective variety

    Natural Energy Bars With Protein Improvement From Animal Origin Foods

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    The energy bars provide the consumer with nutritional and organoleptic quality, as well as a prolonged shelf life without the need to modify the temperature for storage, however, they do not satisfy the nutritional requirements of high-quality proteins since they are usually made from cereals, which are low cost ingredients and great energy contribution. The objective of this study was to create an energetic and nutritious bar, without diminishing the technological quality of the commercial bars and that, due to their sensory characteristics, are easily included in the daily consumption of people who exercise and want to control their weight. A product was formulated with a greater contribution and protein quality, and with a functional dose of macronutrients. The product was prepared in compliance with the regulations of the Ecuadorian Institute for Standardization (INEN) and the Food Codex, the premixing and roasting of ingredients was controlled and finally food with animal protein source such as egg white and powdered milk was added. For the premix oat flakes, nuts such as nuts, almonds and hazelnuts, chia seeds and honey were used, then added egg white and powdered milk. The protein content it reached was 29.01% on a wet basis, a fat value of 23.10% and carbohydrates of 25.24% on 100 g of sample on a wet basis. The energy distribution of macronutrients was balanced, and the sensory evaluation showed good product acceptability. Keywords: cereal bars, protein, immediate energy. Resumen Las barras energéticas proporcionan al consumidor calidad nutricional y organoléptica, así como una vida de anaquel prolongada sin necesidad de modificar la temperatura para su almacenamiento, sin embargo, no satisfacen los requerimientos nutricionales de proteínas de alta calidad ya que generalmente están elaboradas a base de cereales, que son ingredientes de bajo costo y gran aporte energético. El objetivo se este estudio fue crear una barra energética y nutritiva, sin disminuir la calidad tecnológica de las barras comerciales y que por sus características sensoriales sean fácilmente incluidas en el consumo diario de personas que se ejercitan y quieren controlar su peso. Se formuló un producto con un mayor aporte y calidad proteica, y con una dosis funcional de macronutrientes. El producto se elaboró cumpliendo las normativas del Instituto Ecuatoriano de Normalización (INEN) y del Codex alimentario, se controló la premezcla y tostado de ingredientes y finalmente se adicionó los alimentos con fuente proteica animal como la clara de huevo y leche en polvo. Para la premezcla se utilizaron hojuelas de avena, frutos secos como nueces, almendras y avellanas, semillas de chía y miel de abeja, luego se adicionó la clara de huevo y la leche en polvo. El contenido proteico que alcanzó fue de 29,01% en base húmeda, un valor en grasas de 23,10% y de carbohidratos de 25,24% de muestra en base húmeda. La distribución energética de macronutrientes fue equilibrada y la evaluación sensorial arrojó una buena aceptabilidad del producto. Palabras claves: barras de cereales, proteína, energía inmediata

    Sensitivity of Cirrus and Mixed-phase Clouds to the Ice Nuclei Spectra in McRAS-AC: Single Column Model Simulations

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    The salient features of mixed-phase and ice clouds in a GCM cloud scheme are examined using the ice formation parameterizations of Liu and Penner (LP) and Barahona and Nenes (BN). The performance of LP and BN ice nucleation parameterizations were assessed in the GEOS-5 AGCM using the McRAS-AC cloud microphysics framework in single column mode. Four dimensional assimilated data from the intensive observation period of ARM TWP-ICE campaign was used to drive the fluxes and lateral forcing. Simulation experiments where established to test the impact of each parameterization in the resulting cloud fields. Three commonly used IN spectra were utilized in the BN parameterization to described the availability of IN for heterogeneous ice nucleation. The results show large similarities in the cirrus cloud regime between all the schemes tested, in which ice crystal concentrations were within a factor of 10 regardless of the parameterization used. In mixed-phase clouds there are some persistent differences in cloud particle number concentration and size, as well as in cloud fraction, ice water mixing ratio, and ice water path. Contact freezing in the simulated mixed-phase clouds contributed to transfer liquid to ice efficiently, so that on average, the clouds were fully glaciated at T approximately 260K, irrespective of the ice nucleation parameterization used. Comparison of simulated ice water path to available satellite derived observations were also performed, finding that all the schemes tested with the BN parameterization predicted 20 average values of IWP within plus or minus 15% of the observations

    CRANKITE: a fast polypeptide backbone conformation sampler

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    Background: CRANKITE is a suite of programs for simulating backbone conformations of polypeptides and proteins. The core of the suite is an efficient Metropolis Monte Carlo sampler of backbone conformations in continuous three-dimensional space in atomic details. Methods: In contrast to other programs relying on local Metropolis moves in the space of dihedral angles, our sampler utilizes local crankshaft rotations of rigid peptide bonds in Cartesian space. Results: The sampler allows fast simulation and analysis of secondary structure formation and conformational changes for proteins of average length

    A Process for Co-Designing Educational Technology Systems for Refugee Children

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    There is a growing interest in the potential for technology to facilitate emergency education of refugee children. However, designing in this space requires knowledge of the displaced population and the contextual dynamics surrounding it. Design should therefore be informed by both existing research across relevant disciplines, and from the practical experience of those who are on the ground facing the problem in real life. This paper describes a process for designing appropriate technology for these settings. The process draws on literature from emergency education, student engagement and motivation, educational technology, and participatory design. We emphasise a thorough understanding of the problem definition, the nature of the emergency, and of socio-cultural aspects that can inform the design process. We describe how this process was implemented leading to the design of a digital learning space for children living in a refugee camp in Greece. This drew on involving different groups of participants such as social-workers, parents, and children

    Deriving amino acid contact potentials from their frequencies of occurence in proteins: a lattice model study

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    The possibility of deriving the contact potentials between amino acids from their frequencies of occurence in proteins is discussed in evolutionary terms. This approach allows the use of traditional thermodynamics to describe such frequencies and, consequently, to develop a strategy to include in the calculations correlations due to the spatial proximity of the amino acids and to their overall tendency of being conserved in proteins. Making use of a lattice model to describe protein chains and defining a "true" potential, we test these strategies by selecting a database of folding model sequences, deriving the contact potentials from such sequences and comparing them with the "true" potential. Taking into account correlations allows for a markedly better prediction of the interaction potentials

    PKC Signaling Regulates Drug Resistance of the Fungal Pathogen Candida albicans via Circuitry Comprised of Mkc1, Calcineurin, and Hsp90

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    Fungal pathogens exploit diverse mechanisms to survive exposure to antifungal drugs. This poses concern given the limited number of clinically useful antifungals and the growing population of immunocompromised individuals vulnerable to life-threatening fungal infection. To identify molecules that abrogate resistance to the most widely deployed class of antifungals, the azoles, we conducted a screen of 1,280 pharmacologically active compounds. Three out of seven hits that abolished azole resistance of a resistant mutant of the model yeast Saccharomyces cerevisiae and a clinical isolate of the leading human fungal pathogen Candida albicans were inhibitors of protein kinase C (PKC), which regulates cell wall integrity during growth, morphogenesis, and response to cell wall stress. Pharmacological or genetic impairment of Pkc1 conferred hypersensitivity to multiple drugs that target synthesis of the key cell membrane sterol ergosterol, including azoles, allylamines, and morpholines. Pkc1 enabled survival of cell membrane stress at least in part via the mitogen activated protein kinase (MAPK) cascade in both species, though through distinct downstream effectors. Strikingly, inhibition of Pkc1 phenocopied inhibition of the molecular chaperone Hsp90 or its client protein calcineurin. PKC signaling was required for calcineurin activation in response to drug exposure in S. cerevisiae. In contrast, Pkc1 and calcineurin independently regulate drug resistance via a common target in C. albicans. We identified an additional level of regulatory control in the C. albicans circuitry linking PKC signaling, Hsp90, and calcineurin as genetic reduction of Hsp90 led to depletion of the terminal MAPK, Mkc1. Deletion of C. albicans PKC1 rendered fungistatic ergosterol biosynthesis inhibitors fungicidal and attenuated virulence in a murine model of systemic candidiasis. This work establishes a new role for PKC signaling in drug resistance, novel circuitry through which Hsp90 regulates drug resistance, and that targeting stress response signaling provides a promising strategy for treating life-threatening fungal infections
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