1,968 research outputs found

    Hydrostatic Equilibrium of a Perfect Fluid Sphere with Exterior Higher-Dimensional Schwarzschild Spacetime

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    We discuss the question of how the number of dimensions of space and time can influence the equilibrium configurations of stars. We find that dimensionality does increase the effect of mass but not the contribution of the pressure, which is the same in any dimension. In the presence of a (positive) cosmological constant the condition of hydrostatic equilibrium imposes a lower limit on mass and matter density. We show how this limit depends on the number of dimensions and suggest that Λ>0\Lambda > 0 is more effective in 4D than in higher dimensions. We obtain a general limit for the degree of compactification (gravitational potential on the boundary) of perfect fluid stars in DD-dimensions. We argue that the effects of gravity are stronger in 4D than in any other number of dimensions. The generality of the results is also discussed

    Phantom cosmology with a decaying cosmological function Λ(t)\Lambda(t) induced from five-dimensional (5D) geometrical vacuum

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    Introducing a variable cosmological function Λ(t)\Lambda (t) in a geometrical manner from a 5D Riemann-flat metric, we investigate the possibility of having a geometrical criterion to choose a suitable cosmological function Λ(t)\Lambda (t) for every 4D dynamical hypersurface capable of generate phantom cosmologies.Comment: final versio

    Pharmacological and partial biochemical characterization of Bmaj-9 isolated from Bothrops marajoensis snake venom

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    Bmaj-9, a basic PLA2 (13679.33 Da), was isolated from Bothrops marajoensis snake venom through only one chromatographic step in reversed phase HPLC on ¼-Bondapak C-18 column. The amino acid composition showed that Bmaj-9 had a high content of Lys, His, and Arg, typical of a basic PLA2. The sequence of Bmaj-9 contains 124 amino acid residues with a pI value of 8.55, such as DLWQWGQMIL KETGKLPFSY YTAYGCYCGW GGRGGKPKAD TDRCCFVHDC, revealing a high homology with Asp49 PLA2 from other snake venoms. It also exhibited a pronounced phospholipase A2 activity when compared with crude venom. In chick biventer cervicis preparations, the time for 50% and 100% neuromuscular paralysis was respectively (in minutes): 110 ± 10 (1 µg/mL); 40 ± 6 and 90 ± 2 (5 µg/mL); 30 ± 3 and 70 ± 5 (10 µg/mL); 42 ± 1 and 60 ± 2 (20 µg/mL), with no effect on the contractures elicited by either exogenous ACh (110 µM) or KCl (20 mM). Bmaj-9 (10 µg/mL) neither interfered with the muscular response to direct electrical stimulation in curarized preparations nor significantly altered the release of CK at 0, 15, 30 and 60 minutes incubations (27.4 ± 5, 74.2 ± 8, 161.0 ± 21 and 353.0 ± 47, respectively). The histological analysis showed that, even causing blockade at the maximum dosage (5 µg/mL), the toxin does not induce significant morphological alterations such as necrosis or infiltration of inflammatory cells. These results identified Bmaj-9 as a new member of the basic Asp49 PLA2 family able to interact with the motor nerve terminal membrane, thereby inducing a presynaptic neuromuscular blockade181627

    Interacting Kasner-type cosmologies

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    It is well known that Kasner-type cosmologies provide a useful framework for analyzing the three-dimensional anisotropic expansion because of the simplification of the anisotropic dynamics. In this paper relativistic multi-fluid Kasner-type scenarios are studied. We first consider the general case of a superposition of two ideal cosmic fluids, as well as the particular cases of non-interacting and interacting ones, by introducing a phenomenological coupling function q(t)q(t). For two-fluid cosmological scenarios there exist only cosmological scaling solutions, while for three-fluid configurations there exist not only cosmological scaling ones, but also more general solutions. In the case of triply interacting cosmic fluids we can have energy transfer from two fluids to a third one, or energy transfer from one cosmic fluid to the other two. It is shown that by requiring the positivity of energy densities there always is a matter component which violates the dominant energy condition in this kind of anisotropic cosmological scenarios.Comment: Accepted for publication in Astrophysics &Space Science, 8 page

    Diagnostic Accuracy of Anthropometric Markers of Obesity for Prediabetes: A Systematic Review and Meta-Analysis

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    Introduction: Prediabetes is a significant public health concern due to its high risk of progressing to diabetes. Anthropometric measures of obesity, including body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) have been demonstrated as key risk factors in the development of prediabetes. However, there is a lack of clarity on the diagnostic accuracy and cut-off points of these measures. Objective: To determine the diagnostic accuracy of these anthropometric measures for their most effective use in identifying prediabetes. Methodology: A systematic review (SR) with metanalysis of observational studies was carried out. The search was conducted in four databases: Pubmed/Medline, SCOPUS, Web of Science, and EMBASE. For the meta-analysis, sensitivity and specificity, together with their 95% confidence intervals (CI 95%) were calculated. Results: Among all the manuscripts chosen for review, we had four cross-sectional studies, and three were classified as cohort studies. The forest plots showed the combined sensitivity and specificity for both cross-sectional and cohort studies. For cross-sectional studies, the values were as follows: BMI had a sensitivity of 0.63 and specificity of 0.56, WC had a sensitivity of 0.59 and specificity of 0.58, and WHtR had a sensitivity of 0.63 and specificity of 0.73. In the cohort studies, the combined sensitivity and specificity were: BMI at 0.70 and 0.45, WC at 0.68 and 0.56, and WHtR at 0.68 and 0.56, respectively. All values are provided with 95% confidence intervals. Conclusions: This systematic review and meta-analysis evaluated the diagnostic accuracy of BMI, WC, and WHtR in identifying prediabetes. The results showed variations in sensitivity and specificity, with WHtR having the highest specificity in cross-sectional studies and BMI having improved sensitivity in cohort studies

    Desafíos y tendencias del México actual

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    Conjunto de once ensayos cuyo propósito es suscitar la reflexión sobre las tendencias más importantes que marcan el inicio del siglo XXI en México y Jalisco, sin obviar las direcciones que a escala mundial toman la vida social, política y económica.ITESO, A.C

    A global review of problematic and pathogenic parasites of farmed tilapia

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    Over the past 80 years, tilapia have been translocated globally for aquaculture; active production is recorded in >124 countries. Of 7 million tonnes of tilapia produced in aquaculture, 79% is from 79 countries outside the natural range of tilapia. Capture fisheries account for a further 723,627 tonnes of tilapia, and >47% of this is landed from established invasive populations outside Africa. Tilapias host a rich fauna of parasites, many of which have been translocated with their hosts. This review summarises >2500 host–parasite records from 73+ countries and >820 recorded tilapia translocations (provided in the supplementary materials). This work focuses on the notable pathogens that threaten the health of cultured populations of tilapia, providing a description of their pathology and includes species that also have substantial impacts on wild tilapia populations, where relevant. For each major parasite taxonomic group, we highlight which parasites have been translocated or have been acquired from the new environments into which tilapia have been introduced, together with remarks on standard treatment approaches and research on them and their management and control. Regarding the theme ‘Tilapia health: quo vadis?’, Africa has enormous potential for aquaculture growth, but substantial knowledge gaps about tilapia parasites in many African states remain, which creates associated production and biosecurity risks. For each parasitic group, therefore, the risks of parasite translocation to new regions as tilapia aquaculture industries expand are highlighted

    Walking family: Programme of parental skills during foster care and reunification. Summary of main findings of the Project I+D EDU2014-52921-C2. [Infographics]

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    Podeu consultar la versió castellana, francesa i portuguesa al recurs relacionat.Walking Family is a support programme for specific parenting skills in foster care and reunification. Its main aim is to promote the acceptance and involvement of the welfare measure and to foster and strengthen reunification. One of the most relevant aspects of the programme is its group methodology, as it can be used to convey effective coping strategies for everyday problems. Walking Family is characterised by three cornerstones of innovation: positive parenting and child welfare, child participation and family resilience. The programme is developed over 5 modules, each containing 3 sessions. Each session offers activities to do with the children, with the parents and with the family as a unit

    Factors that favor cervical cancer screening in women aged 12 to 49: sub-analysis of the 2019 demographic and family health survey, Peru

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    Introducción: La prueba de Papanicolau ayuda a detectar de manera oportuna en la intervención de rutina el cáncer de cuello uterino. Objetivo: Analizar factores asociados al tamizaje para cáncer de cuello uterino en mujeres de 12 a 49 años en Perú durante el año 2019. Metodología: Se realizó un estudio observacional, analítico-transversal de un análisis secundario de datos de la Encuesta Demográfica y de Salud Familiar del 2019. Muestreo bietápico, probabilístico, equilibrado y estratificado. Se utilizó estadística descriptiva y analítica (nivel de inferencia p<0,05). Para el análisis bivariado y multivariado se utilizaron razones de prevalencia con intervalo de confianza de 95 % y p<0,05. Resultados: La frecuencia de tamizaje de cáncer de cuello uterino en las regiones políticas con menores valores de prevalencia fueron Pasco (0,52 %) y Tumbes (0,55 %). Discusión: Los factores asociados al tamizaje de cáncer de cuello uterino son la edad, tener pareja, nivel educación superior, nivel socioeconómico pobre, residir en área rural, tener seguro de salud, edad de inicio de relaciones sexuales y haber escuchado del cáncer de cuello uterino.Introduction: The Papanicolaou test smear helps detect cervical cancer in a timely manner in routine intervention. Objective: To analyze factors associated with screening for cervical cancer in women aged 12 to 49 years in Peru in 2019. Methods: An observational, analytical-cross-sectional study of a secondary analysis of data from 2019 Demographic and Family Health Survey was carried out. Two-stage, probabilistic, balanced, and stratified sampling. Descriptive and analytical statistics were used (level of inference p<0.05). For the bivariate and multivariate analysis, prevalence ratios were used with a 95% confidence interval and p<0.05. Results: The frequency of cervical cancer screening in the political regions with the lowest prevalence values were Pasco (0.52%) and Tumbes (0.55%). Discussion: The factors associated with cervical cancer screening are age, having a partner, higher education level, poor socioeconomic level, residing in a rural area, having health insurance, age at the start of sexual relations, and having heard of cervical cancer

    Construction of reference chromosome-scale pseudomolecules for potato: integrating the potato genome with genetic and physical maps

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    The genome of potato, a major global food crop, was recently sequenced. The work presented here details the integration of the potato reference genome (DM) with a new STS marker based linkage map and other physical and genetic maps of potato and the closely related species tomato. Primary anchoring of the DM genome assembly was accomplished using a diploid segregating population, which was genotyped with several types of molecular genetic markers to construct a new ~936 cM linkage map comprising 2,469 marker loci. In silico anchoring approaches employed genetic and physical maps from the diploid potato genotype RH and tomato. This combined approach has allowed 951 superscaffolds to be ordered into pseudomolecules corresponding to the 12 potato chromosomes. These pseudomolecules represent 674 Mb (~93%) of the 723 Mb genome assembly and 37,482 (~96%) of the 39,031 predicted genes. The superscaffold order and orientation within the pseudomolecules is closely collinear with independently constructed high density linkage maps. Comparisons between marker distribution and physical location reveal regions of greater and lesser recombination, as well as regions exhibiting significant segregation distortion. The work presented here has led to a greatly improved ordering of the potato reference genome superscaffolds into chromosomal 'pseudomolecules'.Fil: Carboni, Martín Federico. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: D'ambrosio, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional San Cristobal de Huamanga. Laboratorio de Genética y Biotecnología Vegetal; PerúFil: Sharma, Sanjeev Kumar. The James Hutton Institute; Reino UnidoFil: Bolser, Daniel. University of Dundee; Reino UnidoFil: de Boer, Jan. Wageningen University & Researc; Países BajosFil: Sønderkær, Mads . Aalborg University; DinamarcaFil: Amoros, Walter. International Potato Center; PerúFil: de la Cruz, Germán. Universidad Nacional San Cristobal de Huamanga; PerúFil: Di Genova, Alex. Universidad de Chile; ChileFil: Douches, David S.. Michigan State University; Estados UnidosFil: Eguiluz, Maria. Universidad Peruana Cayetano Heredia; PerúFil: Guo, Xiao. Shandong Academy of Agricultural Sciences; ChinaFil: Guzman, Frank. Universidad Peruana Cayetano Heredia; PerúFil: Hackett, Christine A.. Biomathematics and Statistics Scotland; Reino UnidoFil: Hamilton, John P.. Crops Environment and Land Use Programme; IrlandaFil: Li, Guangcun. Shandong Academy of Agricultural Sciences; ChinaFil: Li, Ying. The New Zealand Institute for Plant & Food Research; Nueva ZelandaFil: Lozano, Roberto. Universidad Peruana Cayetano Heredia; PerúFil: Maass, Alejandro. Universidad de Chile; ChileFil: Marshall, David. The James Hutton Institute; Reino UnidoFil: Martinez, Diana. Universidad Peruana Cayetano Heredia; PerúFil: McLean, Karen. The James Hutton Institute; Reino UnidoFil: Mejía, Nilo. Instituto de Investigaciones Agropecuarias. Centro Regional de Investigación La Platina; ChileFil: Milne, Linda. The James Hutton Institute; Reino UnidoFil: Munive, Susan. International Potato Center; PerúFil: Nagy, Istvan. Crops Environment and Land Use Programme; IrlandaFil: Ponce, Olga. Universidad Peruana Cayetano Heredia; PerúFil: Ramirez, Manuel. Universidad Peruana Cayetano Heredia; PerúFil: Simon, Reinhard. International Potato Center; PerúFil: Thomson, Susan J.. Chinese Academy of Agricultural Sciences; Chin
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