Surface Vacuum Energy in Cutoff Models: Pressure Anomaly and Distributional Gravitational Limit

Vacuum-energy calculations with ideal reflecting boundaries are plagued by boundary divergences, which presumably correspond to real (but finite) physical effects occurring near the boundary. Our working hypothesis is that the stress tensor for idealized boundary conditions with some finite cutoff should be a reasonable ad hoc model for the true situation. The theory will have a sensible renormalized limit when the cutoff is taken away; this requires making sense of the Einstein equation with a distributional source. Calculations with the standard ultraviolet cutoff reveal an inconsistency between energy and pressure similar to the one that arises in noncovariant regularizations of cosmological vacuum energy. The problem disappears, however, if the cutoff is a spatial point separation in a "neutral" direction parallel to the boundary. Here we demonstrate these claims in detail, first for a single flat reflecting wall intersected by a test boundary, then more rigorously for a region of finite cross section surrounded by four reflecting walls. We also show how the moment-expansion theorem can be applied to the distributional limits of the source and the solution of the Einstein equation, resulting in a mathematically consistent differential equation where cutoff-dependent coefficients have been identified as renormalizations of properties of the boundary. A number of issues surrounding the interpretation of these results are aired.Comment: 22 pages, 2 figures, 1 table; PACS 03.70.+k, 04.20.Cv, 11.10.G

Optimización de la producción de poli(β-hidroxibutirato) a partir de glicerol

En este trabajo se ha realizado el diseño preliminar de una planta de producción de poli(β-hidroxibutirato), PHB, mediante el empleo de microorganismos y a partir de glicerol como materia prima. El proceso consta de tres etapas: purificación de la materia prima, donde la corriente de glicerol, subproducto en la producción de biodiesel, se despoja del metanol que pudiese contener; fermentación, donde se produce PHB a partir de Cupriavidus necátor y por último, extracción del producto, donde se produce la lisis celular y se logra la separación y purificación del biopolímero.Sociedad Argentina de Informática e Investigación Operativ

Genetic variability and geographic distribution of peanut Arachis hypogaea L. in Ucayali, Peru

El Perú ha sido reconocido como uno de los más importantes centros de diversidad del cultivo de maní y de acuerdo a la evidencia arqueológica, pudo haber sido el centro de origen para dicho cultivo. Para incrementar el conocimiento de la diversidad genética del maní en el Perú, se evaluaron 65 accesiones de maní, correspon-dientes a 21 variedades locales, de las cuencas de los ríos San Alejandro, Ucayali y Aguaytía, de la Región Ucayali. Las accesiones fueron proporcionadas por el proyecto “Modelos de diversidad y de erosión genética en cultivos tradicionales: Asesoría rápida y detección temprana de riesgos usando herramientas SIG”, ejecutado en el Instituto Nacional de Innovación Agraria. Se utilizó la técnica AFLP para estimar la variabilidad genética del cultivo, así como para identificar áreas con la mayor riqueza genética. Se obtuvo un total de 157 bandas polimórficas (45,6%), a partir de 10 combinaciones de iniciadores AFLP en nuestras 65 entradas de maní. Se consideraron sólo 135 bandas polimórficas, en base a su contenido de información polimórfica (0,1Peru has been recognized as one of the most important centers of diversity of the peanut crop and according to archaeological evidence, may have been the center of origin for it. Due to poor knowledge of the current levels of genetic diversity of peanut in Peru, they were evaluated 65 peanut accessions, corresponding to 21 local varieties from the basins of the rivers San Alejandro, Ucayali and Aguaytia, in the Ucayali region; kindly provided by the project "Models of diversity and genetic erosion of traditional crops: Rapid advice and early detection of risks using GIS tools", performed at the “Instituto Nacional de Innovacion Agraria”. AFLP technique was used to estimate the genetic variability of the crop in the region and to identify areas with the greatest genetic wealth. There were a total of 157 polymorphic bands (45.6%), from 10 AFLP primer combinations in our 65 entries of peanuts. We considered only 135 polymorphic bands, based on their polymorphic information content (0.

Synthesis, biological evaluation and computational studies of pyrazole derivatives as Mycobacterium tuberculosis CYP121A1 inhibitors.

A series of imidazole and triazole diarylpyrazole derivatives were prepared using an efficient 5-step synthetic scheme and evaluated for binding affinity with Mycobacterium tuberculosis (Mtb) CYP121A1 and antimycobacterial activity against Mtb H37Rv. Antimycobacterial susceptibility was measured using the spot-culture growth inhibition assay (SPOTi): the imidazoles displayed minimum inhibitory concentration (MIC90) in the range of 3.95–12.03 μg mL−1 (10.07–33.19 μM) with 11f the most active, while the triazoles displayed MIC90 in the range of 4.35–25.63 μg mL−1 (11.88–70.53 μM) with 12b the most active. Assessment of binding affinity using UV-vis spectroscopy showed that for the imidazole series, the propyloxy (11f) and isopropyloxy (11h) derivatives of the 4-chloroaryl pyrazoles displayed Mtb CYP121A1 type II binding affinity with Kd 11.73 and 17.72 μM respectively compared with the natural substrate cYY (Kd 12.28 μM), while in the triazole series, only the methoxy substitution with the 4-chloroaryl pyrazole (12b) showed good type II Mtb CYP121A1 binding affinity (Kd 5.13 μM). Protein-detected 1D 19F-NMR spectroscopy as an orthogonal strategy was used to evaluate ligand binding independent of perturbations at the haem. For imidazole and triazole compounds, perturbations were more intense than cYY indicating tighter binding and confirming that ligand coordination occurs in the substrate-binding pocket despite very modest changes in UV-vis absorbance, consistent with computational studies and the demonstrated potential anti-tuberculosis properties of these compounds

Criteris tècnics per a l’autorització dels centres que realitzen cirurgia refractiva

Cirurgia refractiva; Criteris tècnics; Protocols d'actuació; AutoritzacióCirugía refractiva; Criterios técnicos; Protocolos de actuación; AutorizaciónRefractive surgery; Technical criteria; Action protocols; AuthorizationAquest document presenta una sèrie de recomanacions per tal les noves tècniques de cirurgia refractiva es realitzin en unes instal·lacions adequades i en unes condicions de seguretat òptimes per garantir l’accés de tots els ciutadans a uns serveis de salut de qualitat

Surface hydrophobics mediate functional dimerization of CYP121A1 of Mycobacterium tuberculosis

Tuberculosis is caused by the pathogenic bacterium Mycobacterium tuberculosis (Mtb) and remains the leading cause of death by infection world-wide. The Mtb genome encodes a disproportionate number of twenty cytochrome P450 enzymes, of which the essential enzyme cytochrome P450 121A1 (CYP121A1) remains a target of drug design efforts. CYP121A1 mediates a phenol coupling reaction of the tyrosine dipeptide cyclo-L-Tyr-L-Tyr (cYY). In this work, a structure and function investigation of dimerization was performed as an overlooked feature of CYP121A1 function. This investigation showed that CYP121A1 dimers form via intermolecular contacts on the distal surface and are mediated by a network of solvent-exposed hydrophobic residues. Disruption of CYP121A1 dimers by site-directed mutagenesis leads to a partial loss of specificity for cYY, resulting in an approximate 75% decrease in catalysis. 19F labeling and nuclear magnetic resonance of the enzyme FG-loop was also combined with protein docking to develop a working model of a functional CYP121A1 dimer. The results obtained suggest that participation of a homodimer interface in substrate selectivity represents a novel paradigm of substrate binding in CYPs, while also providing important mechanistic insight regarding a relevant drug target in the development of novel anti-tuberculosis agents

Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the world’s primates from extinction

Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoples’ lands in safeguarding primate biodiversity. We found that Indigenous Peoples’ lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoples’ lands, languages, and cultures represents our greatest chance to prevent the extinction of the world’s primates.info:eu-repo/semantics/publishedVersio

Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the world's primates from extinction

Publisher Copyright: Copyright © 2022 The Authors, some rights reserved.Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoples' lands in safeguarding primate biodiversity. We found that Indigenous Peoples' lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoples' lands, languages, and cultures represents our greatest chance to prevent the extinction of the world's primates.Peer reviewe

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition