Entropy spectrum of a Kerr anti-de Sitter black hole

The entropy spectrum of a spherically symmetric black hole was derived without the quasinormal modes in the work of Majhi and Vagenas. Extending this work to rotating black holes, we quantize the entropy and the horizon area of a Kerr anti-de Sitter black hole by two methods. The spectra of entropy and area are obtained via the Bohr-Sommerfeld quantization rule and the adiabatic invariance in the first way. By addressing the wave function of emitted (absorbed) particles, the entropy and the area are quantized in the second one. Both results show that the entropy and the area spectra are equally spaced.Comment: Accepted for publication in The European Physical Journal C, Volume 72, Issue

GacA is essential for Group A <i>Streptococcus </i>and defines a new class of monomeric dTDP-4-dehydrorhamnose reductases (RmlD)

The sugar nucleotide dTDP-L-rhamnose is critical for the biosynthesis of the Group A Carbohydrate, the molecular signature and virulence determinant of the human pathogen Group A Streptococcus (GAS). The final step of the four-step dTDP-L-rhamnose biosynthesis pathway is catalyzed by dTDP-4-dehydrorhamnose reductases (RmlD). RmlD from the Gram-negative bacterium Salmonella is the only structurally characterized family member and requires metal-dependent homo-dimerization for enzymatic activity. Using a biochemical and structural biology approach, we demonstrate that the only RmlD homologue from GAS, previously renamed GacA, functions in a novel monomeric manner. Sequence analysis of 213 Gram-negative and Gram-positive RmlD homologues predicts that enzymes from all Gram-positive species lack a dimerization motif and function as monomers. The enzymatic function of GacA was confirmed through heterologous expression of gacA in a S. mutans rmlD knockout, which restored attenuated growth and aberrant cell division. Finally, analysis of a saturated mutant GAS library using Tn-sequencing and generation of a conditional-expression mutant identified gacA as an essential gene for GAS. In conclusion, GacA is an essential monomeric enzyme in GAS and representative of monomeric RmlD enzymes in Gram-positive bacteria and a subset of Gram-negative bacteria. These results will help future screens for novel inhibitors of dTDP-L-rhamnose biosynthesis

The top 100 global water questions: Results of a scoping exercise

Global water security presents a complex problem for human societies and will become more acute as the impacts of climate change escalate. Water security connects the practical water and sanitation challenges of households to the dynamics of global hydroclimates and ecosystems in the Anthropocene. To ensure the successful deployment of attention and resources, it is necessary to identify the most pressing questions for water research. Here, we present the results of a scoping exercise conducted across the global water sector. More than 400 respondents submitted an excess of 4,000 potential questions. Drawing on expert analysis, we highlight 100 indicative research questions across six thematic domains: water and sanitation for human settlements; water and sanitation safety risk management; water security and scarcity; hydroclimate-ecosystem-Anthropocene dynamics; multi-level governance; and knowledge production. These questions offer an interdisciplinary and multi-scalar framework for guiding the nature and space of water research for the coming decades

Spectroscopy of the Einstein-Maxwell-Dilaton-Axion black hole

The entropy spectrum of a spherically symmetric black hole was derived via the Bohr-Sommerfeld quantization rule in Majhi and Vagenas's work. Extending this work to charged and rotating black holes, we quantize the horizon area and the entropy of an Einstein-Maxwell-Dilaton-Axion (EMDA) black hole via the Bohr-Sommerfeld quantization rule and the adiabatic invariance. The result shows the area spectrum and the entropy spectrum are respectively equally spaced and independent on the parameters of the black hole.Comment: 9 page

Urinary exosome miR-146a is a potential marker of albuminuria in essential hypertension

BACKGROUND: There is increasing interest in using extracellular vesicle-derived microRNAs (miRNAs) as biomarkers in renal dysfunction and injury. Preliminary evidence indicates that miRNAs regulate the progression of glomerular disease. Indeed, exosomes from the renal system have provided novel evidence in the clinical setting of albuminuria. Thus, the aim of this study was to quantify the urinary miRNAs present in exosome and microvesicles (MVs), and to assess their association with the presence of increased urinary albumin excretion in essential hypertension. METHODS: Exosomes were collected from urine specimens from a cohort of hypertensive patients with (n = 24) or without albuminuria (n = 28), and from 20 healthy volunteers as a control group. Urinary exosomes were phenotyped by Western blot, tunable resistive pulse sensing, and electronic microscopy. Expression of miR-146a and miR-335* was analysed by qRT-PCR and any associations between albuminuria and exosomal miRNAs were analysed. RESULTS: Urinary miRNAs are highly enriched in exosome subpopulations compared to MVs, both in patients with or without increased albuminuria (p < 0.001), but not in the control group. High albuminuria was associated with 2.5-fold less miR-146a in exosomes (p = 0.017), whereas miR-146a levels in MV did not change. In addition, exosome miR-146a levels were inversely associated with albuminuria (r = 0.65, p < 0.0001), and discriminated the presence of urinary albumin excretion presence [area under the curve = 0.80, 95% confidence interval: 0.66-0.95; p = 0.0013]. CONCLUSIONS: Our results indicate that miRNAs were enriched in the urinary exosome subpopulation in hypertensive patients and that low miR-146a expression in exosomes was associated with the presence of albuminuria. Thus, urinary exosome miR-146a may be a potentially useful tool for studying early renal injury in hypertension

Turismo y Género. Una mirada desde Iberoamérica

En las últimas cuatro décadas ha crecido el interés de la academia, gobiernos y organizaciones internacionales por estudiar cómo ha sido, en qué circunstancias y qué efectos ha traído la incorporación de las mujeres al turismo. De esta forma se inicia un debate internacional en el que se cuestionan, por un lado, los efectos negativos de esta actividad en la vida de las mujeres y, por el otro, se realzan beneficios económicos que mejoran su calidad de vida y la de sus familias. A pesar del interés y la importante participación de mujeres en el sector turístico, aún son insuficientes los estudios enfocados en explicar y evidenciar su situación laboral. En este contexto, surge la idea de publicar un libro que compilara trabajos recientes en torno a las condiciones de las trabajadoras en el sector turístico de Iberoamérica.Esta obra se compone de tres secciones, Aproximaciones teórico metodológicas, Mujer y turismo en zonas rurales y La mujer en empresas turísticas, cuyas investigaciones abordan distintos temas para evidenciar los problemas enfrentados por las mujeres, proponer diversas soluciones y comprender su escenario laboral. En la primera sección, hay dos capítulos que proponen marcos teóricos para analizar el empoderamiento de las mujeres en el turismo rural. Los resultados de investigaciones de la segunda sección visibilizan las desigualdades, reflexionan y proponen acciones para mejorar las condiciones de las trabajadoras turísticas. En la última, en los tres capítulos, concentrados en las actividades empresariales, se estudian las desventajas y obstáculos de la empleada en alguna compañía turística.Universidad Autónoma del Estado de México

Drivers of joint cropland management strategies in agri-food cooperatives

[EN] In several Spanish regions, collective action through production and marketing cooperatives has traditionally concentrated the food supply of small and medium-sized farms. However, many cooperatives are threatened by the risk of abandonment of members' cropland, which reduces their sourcing capacity. In this context, joint cropland management initiatives have become a useful form of social and organizational innovation. This research's contribution is twofold: it examines the relevance of some drivers of this organizational innovation, and it determines the cooperative characteristics or combinations of characteristics that can sufficiently explain the adoption of a joint cropland management strategy. Some cooperatives' features have been a priori identified as related to the achievement of joint cropland initiatives: economic size, social innovation, innovative behavior, and collaborative orientation. The study is mainly based on data from a cooperatives survey, and fuzzy set Qualitative Comparative Analysis (fsQCA) methodology has been used. The analysis has been completed by surveying cooperatives' managers about their opinions on a joint cropland management strategy's main advantages and drivers. Results indicate that social and economic innovation, size, and propensity to cooperate with other cooperatives are key factors that help create a cooperative profile capable of tackling the challenge of land abandonment and the consequent loss of production.Ministry of Science and Innovation, Spain, European Regional Development Fund, European Commission. Project "Strengthening innovation policy in the agri-food sector" (RTI2018-093791-B-C22).Piñeiro, V.; Martinez Gomez, VD.; Melia-Marti, E.; García Alvarez-Coque, JM. (2021). Drivers of joint cropland management strategies in agri-food cooperatives. Journal of Rural Studies. 84:162-173. https://doi.org/10.1016/j.jrurstud.2021.04.003S1621738

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO