Observational Constraints on the Ages of Molecular Clouds and the Star-Formation Timescale: Ambipolar-Diffusion--Controlled or Turbulence-Induced Star Formation?

We revisit the problem of the star formation timescale and the ages of molecular clouds. The apparent overabundance of star-forming molecular clouds over clouds without active star formation has been thought to indicate that molecular clouds are "short-lived" and that star formation is "rapid". We show that this statistical argument lacks self-consistency and, even within the rapid star-formation scenario, implies cloud lifetimes of approximately 10 Myr. We discuss additional observational evidence from external galaxies that indicate lifetimes of molecular clouds and a timescale of star formation of approximately 10 Myr . These long cloud lifetimes in conjunction with the rapid (approximately 1 Myr) decay of supersonic turbulence present severe difficulties for the scenario of turbulence-controlled star formation. By contrast, we show that all 31 existing observations of objects for which the linewidth, the size, and the magnetic field strength have been reliably measured are in excellent quantitative agreement with the predictions of the ambipolar-diffusion theory. Within the ambipolar-diffusion-controlled star formation theory the linewidths may be attributed to large-scale non-radial cloud oscillations (essentially standing large-amplitude, long-wavelength Alfven waves), and the predicted relation between the linewidth, the size, and the magnetic field is a natural consequence of magnetic support of self-gravitating clouds.Comment: 7 pages, 2 figures, uses emulateapj; accepted for publication in Ap

Dynamic Multi-Objective Optimization With jMetal and Spark: a Case Study

Technologies for Big Data and Data Science are receiving increasing research interest nowadays. This paper introduces the prototyping architecture of a tool aimed to solve Big Data Optimization problems. Our tool combines the jMetal framework for multi-objective optimization with Apache Spark, a technology that is gaining momentum. In particular, we make use of the streaming facilities of Spark to feed an optimization problem with data from different sources. We demonstrate the use of our tool by solving a dynamic bi-objective instance of the Traveling Salesman Problem (TSP) based on near real-time traffic data from New York City, which is updated several times per minute. Our experiment shows that both jMetal and Spark can be integrated providing a software platform to deal with dynamic multi-optimization problems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Age difference between heterosexual partners in Britain: Implications for the spread of Chlamydia trachomatis

Heterosexual partners often differ in age. Integrating realistic patterns of sexual mixing by age into dynamic transmission models has been challenging. The effects of these patterns on the transmission of sexually transmitted infections (STI) including Chlamydia trachomatis (chlamydia), the most common bacterial STI are not well understood. We describe age mixing between new heterosexual partners using age- and sex-specific data about sexual behavior reported by people aged 16-63 years in the 2000 and 2010 British National Surveys of Sexual Attitudes and Lifestyles. We incorporate mixing patterns into a compartmental transmission model fitted to age- and sex-specific, chlamydia positivity from the same surveys, to investigate C. trachomatis transmission. We show that distributions of ages of new sex partners reported by women and by men in Britain are not consistent with each other. After balancing these distributions, new heterosexual partnerships tend to involve men who are older than women (median age difference 2, IQR -1, 5 years). We identified the most likely age combinations of heterosexual partners where incident C. trachomatis infections are generated. The model results show that in >50% of chlamydia transmitting partnerships, at least one partner is ≥25 years old. This study illustrates how sexual behavior data can be used to reconstruct detailed sexual mixing patterns by age, and how these patterns can be integrated into dynamic transmission models. The proposed framework can be extended to study the effects of age-dependent transmission on incidence in any STI

Factores Asociados a la Gingivitis en Gestantes en una Población Desfavorecida

Objective: The objective was to determine the factors associated with gingivitis in pregnant women who come to the health center in the district of San José de Sisa.  Methodology: The research was of a basic type and the research design was non-experimental, descriptive, cross-sectional and correlational.  The population and sample was the same as the population, that is, 110 pregnant women from the District of San José de Sisa with a non-probabilistic sampling for convenience to which a questionnaire of 5 questions on oral hygiene habits and sociodemographic factors and a clinical evaluation to observe the gingival state were provided.  Results: The study revealed that the associated factors were socioeconomic status where it was found that 43.5% at the mean level had gingivitis with a p value = 0.002, with reference to the age group 48.2% with gingival disease were between 20 and 29 years old with a p value = 0.280; 43.6% of pregnant women with gingivitis reported brushing at least 2 times a day when obtaining a p =0.098, el 41.7% in the second trimester presented gingivitis with a p value = 0.004. When comparing the information of the degree of instruction it was found that pregnant women with gingivitis were found that 40% had only primary and 39.1% secondary, when obtaining a p value = 0.000.  Conclusions: It concluded that there is a significant relationship between gingivitis and socioeconomic status (p=0.002), with the trimester of pregnancy (p=0.004), and with the degree of education of the pregnant woman (p=0.000); but found no statistical relationship with the age group (p=0.280) or with oral hygiene habits (p=0.098).Objetivo: El objetivo fue determinar los factores asociados a la gingivitis en las gestantes que acuden al centro de salud del distrito de San José de Sisa. Metodología: La investigación fue de tipo básica y el diseño de investigación fue no experimental, descriptivo, transversal y correlacional. La población y muestra, fue la misma que la población es decir 110 gestantes del Distrito de san José de Sisa con un muestreo no probabilístico por conveniencia a las cuales se les brindó un cuestionario de 5 preguntas sobre hábitos de higiene oral y factores sociodemográficos y una evaluación clínica para observar el estado gingival. Resultados: El estudio revelo que los factores asociados fueron el estatus socioeconómico en donde se encontró que el 43,5% al nivel medio tenían gingivitis con un p valor =0,002, con referencia al grupo etario el 48,2% con enfermedad gingival tenían entre 20 y 29 años con un p valor =0,280; el 43,6% de gestantes con gingivitis refirió cepillarse por lo menos 2 veces al día al obtener un p=0,098, el 41,7% en el segundo trimestre presentó gingivitis con un p valor =0,004. Al cotejar la información del grado de instrucción se encontró que las gestantes con gingivitis se encontraron que 40% tenían sólo primaria y 39,1% secundaria, al obtener un p valor =0,000. Conclusiones: Concluyó que existe relación significativa entre gingivitis y el nivel socioeconómico (p=0,002), con el trimestre de embarazo (p=0,004), y con el grado de instrucción de la gestante (p=0,000); pero no encontró relación estadística con el grupo etario (p=0,280) ni con los hábitos de higiene oral (p=0,098)

Distinguishing Healthy Ageing from Dementia: A Biomechanical Simulation of Brain Atrophy Using Deep Networks

Biomechanical modeling of tissue deformation can be used to simulate different scenarios of longitudinal brain evolution. In this work, we present a deep learning framework for hyper-elastic strain modelling of brain atrophy, during healthy ageing and in Alzheimer’s Disease. The framework directly models the effects of age, disease status, and scan interval to regress regional patterns of atrophy, from which a strain-based model estimates deformations. This model is trained and validated using 3D structural magnetic resonance imaging data from the ADNI cohort. Results show that the framework can estimate realistic deformations, following the known course of Alzheimer’s disease, that clearly differentiate between healthy and demented patterns of ageing. This suggests the framework has potential to be incorporated into explainable models of disease, for the exploration of interventions and counterfactual examples

Behavioral Effects of Developmental Exposure to JWH-018 in Wild-Type and Disrupted in Schizophrenia 1 (disc1) Mutant Zebrafish

Synthetic cannabinoids can cause acute adverse psychological effects, but the potential impact when exposure happens before birth is unknown. Use of synthetic cannabinoids during pregnancy may affect fetal brain development, and such effects could be moderated by the genetic makeup of an individual. Disrupted in schizophrenia 1 (DISC1) is a gene with important roles in neurodevelopment that has been associated with psychiatric disorders in pedigree analyses. Using zebrafish as a model, we investigated (1) the behavioral impact of developmental exposure to 3 μM 1-pentyl-3-(1-naphthoyl)-indole (JWH-018; a common psychoactive synthetic cannabinoid) and (2) whether disc1 moderates the effects of JWH-018. As altered anxiety responses are seen in several psychiatric disorders, we focused on zebrafish anxiety-like behavior. Zebrafish embryos were exposed to JWH-018 from one to six days post-fertilization. Anxiety-like behavior was assessed using forced light/dark and acoustic startle assays in larvae and novel tank diving in adults. Compared to controls, both acutely and developmentally exposed zebrafish larvae had impaired locomotion during the forced light/dark test, but anxiety levels and response to startle stimuli were unaltered. Adult zebrafish developmentally exposed to JWH-018 spent less time on the bottom of the tank, suggesting decreased anxiety. Loss-of-function in disc1 increased anxiety-like behavior in the tank diving assay but did not alter sensitivity to JWH-018. Results suggest developmental exposure to JWH-018 has a long-term behavioral impact in zebrafish, which is not moderated by disc1

Memory consolidation in the cerebellar cortex

Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABA(A) agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage

Induction of fibroblast senescence generates a non-fibrogenic myofibroblast phenotype that differentially impacts on cancer prognosis

Cancer-associated fibroblasts (CAF) remain a poorly characterized, heterogeneous cell population. Here we characterized two previously described tumor-promoting CAF sub-types, smooth muscle actin (SMA)-positive myofibroblasts and senescent fibroblasts, identifying a novel link between the two