Non Abelian TQFT and scattering of self dual field configuration

A non-abelian topological quantum field theory describing the scattering of self-dual field configurations over topologically non-trivial Riemann surfaces, arising from the reduction of 4-dim self-dual Yang-Mills fields, is introduced. It is shown that the phase space of the theory can be exactly quantized in terms of the space of holomorphic structures over stable vector bundles of degree zero over Riemann surfaces. The Dirac monopoles are particular static solutions of the field equations. Its relation to topological gravity is discussed.Comment: 13 pages, Late

Timing is everything: early degradation of abscission layer is associated with increased seed shattering in U.S. weedy rice

Background Seed shattering, or shedding, is an important fitness trait for wild and weedy grasses. U.S. weedy rice (Oryza sativa) is a highly shattering weed, thought to have evolved from non-shattering cultivated ancestors. All U.S. weedy rice individuals examined to date contain a mutation in the sh4 locus associated with loss of shattering during rice domestication. Weedy individuals also share the shattering trait with wild rice, but not the ancestral shattering mutation at sh4; thus, how weedy rice reacquired the shattering phenotype is unknown. To establish the morphological basis of the parallel evolution of seed shattering in weedy rice and wild, we examined the abscission layer at the flower-pedicel junction in weedy individuals in comparison with wild and cultivated relatives. Results Consistent with previous work, shattering wild rice individuals possess clear, defined abscission layers at flowering, whereas non-shattering cultivated rice individuals do not. Shattering weedy rice from two separately evolved populations in the U.S. (SH and BHA) show patterns of abscission layer formation and degradation distinct from wild rice. Prior to flowering, the abscission layer has formed in all weedy individuals and by flowering it is already degrading. In contrast, wild O. rufipogon abscission layers have been shown not to degrade until after flowering has occurred. Conclusions Seed shattering in weedy rice involves the formation and degradation of an abscission layer in the flower-pedicel junction, as in wild Oryza, but is a developmentally different process from shattering in wild rice. Weedy rice abscission layers appear to break down earlier than wild abscission layers. The timing of weedy abscission layer degradation suggests that unidentified regulatory genes may play a critical role in the reacquisition of shattering in weedy rice, and sheds light on the morphological basis of pa

PENSAMIENTO MATEMÁTICO EN RELACIÓN CON LAS PRUEBAS PISA

Los Lineamientos Curriculares para el área de matemáticas expedidos por el MEN, vigentes actualmente, plantean que su enseñanza se debe desarrollar en el marco de cinco procesos generales: resolución y planteamientos de problemas, modelación, razonamiento, comunicación y elaboración, comparación y ejercitación de procedimientos, en la perspectiva de promover y fomentar el desarrollo de pensamiento matemático. Teniendo en cuenta que en la prueba PISA, en lo que respecta a matemáticas, los contenidos, procesos y contextos son similares a los que plantea el MEN, se considera conveniente analizar el pensamiento matemático de los estudiantes a través de sus desempeños en PISA, porque allí se evalúa “…qué tan bien preparados están los estudiantes de 15 años de edad para enfrentar los retos de la vida adulta” (ICFES, 2013)

Climate change and healthy ageing: An assessment of the impact of climate hazards on older people

Copyright \ua9 2024 by the Journal of Global Health. All rights reserved. Background: Climate change not only directly impacts older people\u27s longevity but also healthy ageing, which is the process of maintaining physical and mental capacities while optimising functional abilities. The urgency to address both population ageing and climate change necessitates a rethink and assessment of the impact of climate change on older people. This includes identifying what can be done to anticipate, mitigate and adapt to climate change and engage older persons. Methods: A review of climate change and healthy ageing forms the basis of evidence in this report. We developed a comprehensive search to assess current literature, combining terms related to ageing and climate change across four major data sets and assessing articles published up to the end of 2021. Results: We summarised the current and future impact of climate change on older people and developed a framework identifying climate change impacts on older persons, recognising social and environmental determinants of healthy ageing. Major hazards and some key exposure pathways include extreme temperatures, wildfire, drought, flooding, storm and sea level rise, air quality, climate-sensitive infectious diseases, food and water insecurities, health and social care system displacement, migration, and relocation. Strategies to address climate change require interventions to improve systems and infrastructure to reduce vulnerability and increase resilience. As a heterogeneous group, older people\u27s perceptions of climate change should be integrated into climate activism. Increasing climate change literacy among older people and enabling them to promote intergenerational dialogue will drive the development and implementation of equitable solutions. Pathways may operate via direct or indirect exposures, requiring longitudinal studies that enable assessment of exposures and outcomes at multiple time points, and analyses of cumulative impacts of hazards across the life course. Conclusions: The lack of systematic reviews and primary research on the impact of most climate hazards, except for heat, on older people is apparent. Future research should include outcomes beyond mortality and morbidity and assess how older people interact with their environment by focusing on their capacities and optimising abilities for being and doing what they value

A model for the development of programming courses to promote the participation of young women in STEM

There is a gender gap in science, technology, engineering, and mathematics (STEM), and this is a global problem that affects society. However, it is worth pointing out that the gap is not uniform in all STEM fields. Women’s underrepresentation is more marked in physics, engineering, and computer science fields. Nowadays, the labor market is becoming more competitive, technology-based and demands a diverse workforce. Therefore, it is important to continue promoting the participation of women in STEM, and the universities play a leading role in it. Previous research has shown that early learning experiences in STEM can show female students that they can succeed in this fields. This paper describes a model for developing programming courses for pre-university students to promote the participation of young women in STEM programs. The course was developed in one week, 25 students (16 girls and 9 boys) participated. The instructors of the course were four female professors. The programming language was Python, and the methodology used case-based learning. Both instructors and students gave positive comments on their experience in the course. The proposed model, including instruments, learning resources, and methodology, can be replicated and adapted to be used even in other learning field

A complex relationship among chemical concentration, detection threshold and suprathreshold intensity of bitter compounds

Detection thresholds and psychophysical curves were established for caffeine, quinine-HCl (QHCl), and propylthiouracil (PROP) in a sample of 33 subjects (28 female mean age 24 &plusmn; 4). The mean detection threshold (&plusmn;standard error) for caffeine, QHCl, and PROP was 1.2 &plusmn; 0.12, 0.0083 &plusmn; 0.001, and 0.088 &plusmn; 0.07 mM, respectively. Pearson product&ndash;moment analysis revealed no significant correlations between detection thresholds of the compounds. Psychophysical curves were constructed for each bitter compound over 6 concentrations. There were significant correlations between incremental points of the individual psychophysical curves for QHCl and PROP. Regarding caffeine, there was a specific concentration (6 mM) below and above which the incremental steps in bitterness were correlated. Between compounds, analysis of psychophysical curves revealed no correlations with PROP, but there were significant correlations between the bitterness of caffeine and QHCl at higher concentrations on the psychophysical curve (P &lt; 0.05). Correlation analysis of detection threshold and suprathreshold intensity within a compound revealed a significant correlation between PROP threshold and suprathreshold intensity (r = 0.46&ndash;0.4, P &lt; 0.05), a significant negative correlation for QHCl (r = &ndash;0.33 to &ndash;0.4, P &lt; 0.05), and no correlation for caffeine. The results suggest a complex relationship between chemical concentration, detection threshold, and suprathreshold intensity.<br /

Medición de la autorregulación cerebral derivada de la espectroscopia de infrarrojo cercano en recién nacidos: de la herramienta de investigación al monitoreo multimodal junto a la cama

Cerebral autoregulation (CAR), the ability of the human body to maintain cerebral blood flow (CBF) in a wide range of perfusion pressures, can be calculated by describing the relation between arterial blood pressure (ABP) and cerebral oxygen saturation measured by near-infrared spectroscopy (NIRS). In literature, disturbed CAR is described in different patient groups, using multiple measurement techniques and mathematical models. Furthermore, it is unclear to what extent cerebral pathology and outcome can be explained by impaired CAR

Features of dengue and chikungunya infections of colombian children under 24 months of age admitted to the emergency department

We aimed to assess clinical and laboratory differences between dengue and chikungunya in children <24 months of age in a comparative study. We collected retrospective clinical and laboratory data confirmed by NS1/IgM for dengue for 19 months (1 January 2013 to 17 August 2014). Prospective data for chikungunya confirmed by real-time polymerase chain reaction were collected for 4 months (22 September 2014-14 December 2014). Sensitivity and specificity [with 95% confidence interval (CI)] were reported for each disease diagnosis. A platelet count <150 000 cells/ml at emergency admission best characterized dengue, with a sensitivity of 67% (95% CI, 53-79) and specificity of 95% (95% CI, 82-99). The algorithm developed with classification and regression tree analysis showed a sensitivity of 93% (95% CI, 68-100) and specificity of 38% (95% CI, 9-76) to diagnose dengue. Our study provides potential differential characteristics between chikungunya and dengue in young children, especially low platelet counts. © The Author [2017].Universidad Nacional de Colombia, UN Johns Hopkins University1Departamento de Epidemiologia, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Cartagena, Colombia 2Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia 3Departamento de Epidemiologia, Faculdade de Saúde Publica, Universidade de São Paulo, São Paulo, Brazil 4Facultad de Ingenería, Universidad Tecnológica de Bolívar, Cartagena, Colombia 5Facultad Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla, Colombia 6Facultad de Medicina, Universidad de Cartagena, Cartagena, Colombia 7Instituto de Investigaciones Biologicas del Tropico, Universidad de Córdoba, Montería, Colombia 8Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA Correspondence: Angel Paternina-Caicedo, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Bruselas Transversal 36 N. 36-33, Cartagena, Bolívar, Colombia. Tel: +1-412-3267809. E-mail or

The algebra of adjacency patterns: Rees matrix semigroups with reversion

We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion. In particular, the lattice of subvarieties of the variety generated by adjacency semigroups that are regular unary semigroups is essentially the same as the lattice of universal Horn classes of reflexive directed graphs. A number of examples follow, including a limit variety of regular unary semigroups and finite unary semigroups with NP-hard variety membership problems.Comment: 30 pages, 9 figure