697 research outputs found

    Nonperturbative hyperfine contribution to the b1b_1 and h1h_1 meson masses

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    Due to the nonperturbative contribution to the hyperfine splitting the mass of the n1P1n^1P_1 state is strongly correlated with the center of gravity Mcog(n3PJ)M_{\rm cog}(n^3P_J) of the n3PJn^3P_J multiplet: M(n1P1)M(n^1P_1) is less than Mcog(n3PJ)M_{\rm cog}(n^3P_J) by about 40 MeV (20 MeV) for the 1P (2P) state. For b1(1235)b_1(1235) the agreement with experiment is reached only if a0(980)a_0(980) belongs to the 13PJ1^3P_J multiplet. The predicted mass of b1(21P1)b_1(2^1P_1) is 1620\approx 1620 MeV. For the isoscalar meson a correlation between the mass of h1h_1(1170) (h1(1380))(h_1(1380)) and Mcog(13PJ)M_{cog}(1^3P_J) composed from light (strange) quarks also takes place.Comment: 22 pages RevTe

    Perfil de ingreso de los alumnos de Enfermería, Facultades de Estudios Superiores Iztacala y Zaragoza, UNAM

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    ResumenIntroducciónLa Universidad tiene como una de sus tareas conocer a los estudiantes, ya que en la medida que nuestro sistema de educación logre tener mayor información sobre el perfil de éstos y sus trayectorias escolares, se podrán diseñar e implementar políticas novedosas y funcionales que atiendan las necesidades específicas de su población.ObjetivoAnalizar el perfil de los estudiantes que ingresan a la Licenciatura en Enfermería de las Facultades de Estudios Superiores (FES) Iztacala y Zaragoza.MétodoEstudio descriptivo-transversal, con estudiantes de primer ingreso de la generación 2011-1 de la FES Zaragoza e Iztacala. La población de estudio fueron 600 alumnos. La recolección de la información fue a través de un cuestionario. La confiabilidad del instrumento fue de 0.875 con la prueba de Alfa de Cronbach. Para el manejo de la información se elaboró una base de datos con el programa SPSS® y se utilizó estadística descriptiva.ResultadosEl 49% de alumnos proviene de pase reglamentado, el promedio de ingreso es de 8.1 a 9.0; en el 61% Enfermería fue primera elección; el nivel socioeconómico de los alumnos es bajo; en el 74% el promedio durante el primer año fue de 8.0 a 10.0.DiscusiónA diferencia de otras Carreras de la Universidad Nacional Autónoma de México (UNAM), la de Enfermería da cabida a casi el 50% de los aspirantes de escuelas externas a ella. Los alumnos aún cuando son de nivel socioeconómico bajo, reúnen características favorables para su trayectoria escolar, entre ellas, un buen promedio y que fueron admitidos en la Carrera que seleccionaron.AbstractIntroductionThe University has as one of its tasks to better know the profiles and trajectories of students, so that supporting innovative and functional policies can be designed and implemented.ObjectiveTo analyze the profile of students enrolling into the Nursing Undergraduate System at the Iztacala and Zaragoza Superior Studies Faculty.MethodBasic-descriptive study with freshmen students of the 2011 -I generation of the Nursing Bachelors Degree program at the FES Zaragoza and Iztacala. The population was 600 alumni. A questionnaire was used to gather data. The instrument reliability was equivalent to a 0.875 Cronbach Alpha score. A SPSS8 database was created and data were analyzed through descriptive statistics.ResultsThe 49% of the students came from the “automatic pass” format. The enrollment grade point average went from 8.1 to 9.0. For the 61% of the students, nursing was their first choice of major. The socioeconomic level of the students was low. The 76% of the students obtained a grade point average between 8.0 and 10.0 during all their freshman year.DiscussionUnlike other careers at the Universidad Nacional Autónoma de México (UNAM), Nursing accepts almost 50% of the prospects from external schools, situation which does not occur in other careers. Although the majority of students who entered have a low social-economical level, they have other favorable characteristics for their school trajectory such as a good grade point average and that they were accepted in the career that they chose

    Effects of sublethal doses of methoxyfenozide on the development, survival and reproduction of Spodoptera frugiperda.

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    The lethal and sublethal effects of the ecdysone agonist methoxyfenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyfenozide-treated diet to ϐifth instars until pupation in doses corresponding to the LC 10 and LC 25 for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC 10 and 60% for the LC 25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a signiϐicant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from ϐifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armywor

    Phase space reduction of the one-dimensional Fokker-Planck (Kramers) equation

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    A pointlike particle of finite mass m, moving in a one-dimensional viscous environment and biased by a spatially dependent force, is considered. We present a rigorous mapping of the Fokker-Planck equation, which determines evolution of the particle density in phase space, onto the spatial coordinate x. The result is the Smoluchowski equation, valid in the overdamped limit, m->0, with a series of corrections expanded in powers of m. They are determined unambiguously within the recurrence mapping procedure. The method and the results are interpreted on the simplest model with no field and on the damped harmonic oscillator.Comment: 13 pages, 1 figur

    Two-way plant mediated interactions between root-associated microbes and insects: from ecology to mechanisms

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    Plants are members of complex communities and function as a link between above- and below-ground organisms. Associations between plants and soil-borne microbes commonly occur and have often been found beneficial for plant fitness. Root-associated microbes may trigger physiological changes in the host plant that influence interactions between plants and aboveground insects at several trophic levels. Aboveground, plants are under continuous attack by insect herbivores and mount multiple responses that also have systemic effects on belowground microbes. Until recently, both ecological and mechanistic studies have mostly focused on exploring these below- and above-ground interactions using simplified systems involving both single microbe and herbivore species, which is far from the naturally occurring interactions. Increasing the complexity of the systems studied is required to increase our understanding of microbe-plant-insect interactions and to gain more benefit from the use of non-pathogenic microbes in agriculture. In this review, we explore how colonization by either single non-pathogenic microbe species or a community of such microbes belowground affects plant growth and defense and how this affects the interactions of plants with aboveground insects at different trophic levels. Moreover, we review how plant responses to foliar herbivory by insects belonging to different feeding guilds affect interactions of plants with non-pathogenic soil-borne microbes. The role of phytohormones in coordinating plant growth, plant defenses against foliar herbivores while simultaneously establishing associations with non-pathogenic soil microbes is discussed

    Nonperturbative QCD Vacuum Effects in Nonlocal Quark Dynamics

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    A straightforward calculation reveals the essentially nonlocal character of the leading heavy QQˉQ\bar{Q} interaction arising from nonperturbative gluon field correlations in the model of a fluctuating QCD vacuum. In light of this quarkonium spin splitting ratio predictions which have supported the scalar confinement ansatz are reconsidered as a specific example of possible consequences for spectroscopy.Comment: Latex, 9 page

    Cell shape analysis of random tessellations based on Minkowski tensors

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    To which degree are shape indices of individual cells of a tessellation characteristic for the stochastic process that generates them? Within the context of stochastic geometry and the physics of disordered materials, this corresponds to the question of relationships between different stochastic models. In the context of image analysis of synthetic and biological materials, this question is central to the problem of inferring information about formation processes from spatial measurements of resulting random structures. We address this question by a theory-based simulation study of shape indices derived from Minkowski tensors for a variety of tessellation models. We focus on the relationship between two indices: an isoperimetric ratio of the empirical averages of cell volume and area and the cell elongation quantified by eigenvalue ratios of interfacial Minkowski tensors. Simulation data for these quantities, as well as for distributions thereof and for correlations of cell shape and volume, are presented for Voronoi mosaics of the Poisson point process, determinantal and permanental point processes, and Gibbs hard-core and random sequential absorption processes as well as for Laguerre tessellations of polydisperse spheres and STIT- and Poisson hyperplane tessellations. These data are complemented by mechanically stable crystalline sphere and disordered ellipsoid packings and area-minimising foam models. We find that shape indices of individual cells are not sufficient to unambiguously identify the generating process even amongst this limited set of processes. However, we identify significant differences of the shape indices between many of these tessellation models. Given a realization of a tessellation, these shape indices can narrow the choice of possible generating processes, providing a powerful tool which can be further strengthened by density-resolved volume-shape correlations.Comment: Chapter of the forthcoming book "Tensor Valuations and their Applications in Stochastic Geometry and Imaging" in Lecture Notes in Mathematics edited by Markus Kiderlen and Eva B. Vedel Jense

    Cross-country migration linked to people who inject drugs challenges the long-term impact of national HCV elimination programmes

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    To the Editor: As of 2018, the majority of Western European countries – including Spain – have lifted restrictions to therapy based on disease severity in the context of HCV infections.1 Long overdue, most national elimination programmes now also include access to care for people who inject drugs (PWID), 2 who are at the core of ongoing HCV transmission.3 Macías et al.4 have recently shown in this Journal that high viral cure rates can be achieved in this group, hereby providing evidence that targeting PWID in treatment programmes is worthwhile. However, the extent to which such national efforts can reduce the HCV burden not only depends on the uptake into care and treatment success rates, it is also determined by the relative importance of within-country transmission and virus importation from elsewhere. As the chronic nature of most HCV infections hampers reliably reconstructing contact networks from patient interviews, virus genetic data can be a valuable alternative source of information for elucidating the geographic history of virus lineages (e.g. [5], [6]). Using such data, we have recently shown that for the most prevalent subtype among PWID in Spain (40%, 7), HCV1a, infections often link to infections abroad – in recent years >50% link to Western European countries, mostly European Union (EU) member states – as opposed to other infections ..

    Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.

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    Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification
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