Soldered Bundle Background for the De Sitter Top

We prove that the mathematical framework for the de Sitter top system is the de Sitter fiber bundle. In this context, the concept of soldering associated with a fiber bundle plays a central role. We comment on the possibility that our formalism may be of particular interest in different contexts including MacDowell-Mansouri theory, two time physics and oriented matroid theory.Comment: 12 pages, Latex; some improvements introduced, reference added, typos correcte

The de Sitter Relativistic Top Theory

We discuss the relativistic top theory from the point of view of the de Sitter (or anti de Sitter) group. Our treatment rests on Hanson-Regge's spherical relativistic top lagrangian formulation. We propose an alternative method for studying spinning objects via Kaluza-Klein theory. In particular, we derive the relativistic top equations of motion starting with the geodesic equation for a point particle in 4+N dimensions. We compare our approach with the Fukuyama's formulation of spinning objects, which is also based on Kaluza-Klein theory. We also report a generalization of our approach to a 4+N+D dimensional theory.Comment: 25 pages, Latex,commnets and references adde

Predicting the Onset of Alcohol Use and the Development of Alcohol Use Disorder Among Indigenous Adolescents

Empirical efforts to identify the predictors of drinking behavior among North American Indigenous adolescents are relatively limited. Using longitudinal data, this study considers perceived discrimination, positive drinker prototypes, and peer drinking behavior as risk factors for the onset of alcohol use and development of an alcohol use disorder among 674 Indigenous adolescents as they progressed from early to late adolescence (M age at baseline = 11.11, SD = 0.83). Results showed that positive drinker prototypes and associations with peers who drink increased the risk for the onset of drinking, while perceived discrimination and associations with peers who drink increased the risk for the development of an alcohol use disorder. The theoretical and practical implications of our results are discussed

A Longitudinal Examination of the Measurement Properties and Predictive Utility of the Center for Epidemiologic Studies Depression Scale Among North American Indigenous Adolescents

We examined the longitudinal measurement properties and predictive utility of the Center for Epidemiologic Studies Depression Scale (CES-D) from early to late adolescence among a sample of North American Indigenous youths. Participants were 632 North American Indigenous adolescents (n = 632; 50.3% girls; M age at baseline = 11.11 years) participating in an 8-year, 8-wave longitudinal study. Via in-person interviews, participants completed the CES-D at Waves 1, 3, 5, and 7, and the major depressive disorder (MDD) module of the Diagnostic Interview Schedule for Children at Waves 1, 4, 6, and 8. Confirmatory factor analyses indicated that responses to the CES-D were similarly explained by 2-, 3-, and 4-factor models, as well as a 1-factor model with correlations between the error variances for the positively worded items. Longitudinal measurement equivalence analyses indicated full structural (i.e., factor structure), metric (i.e., factor loadings), and scalar (i.e., observed item intercepts) equivalence for each factor structure. Substantive analyses showed that the CES-D was significantly associated with MDD both concurrently and prospectively, although these effects were smaller than might be expected. Finally, the CES-D negative affect and somatic complaints subscales were the strongest and most consistent predictors of MDD. Among our sample of North American Indigenous youths, the measurement properties of the CES-D were stable from early to late adolescence. Moreover, somatic difficulties and depressed affect were the strongest predictors of MDD

Local diurnal wind‐driven variability and upwelling in a small coastal embayment

The oceanic response to high‐frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first‐mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal evolution of the hydrographic structure and circulation in the bay is examined using both individual events and composite‐day averages. During the late afternoon, the local wind strengthens and results in a sheared flow with near‐surface warm waters directed out of the bay and a compensating flow of colder waters into the bay over the bottom portion of the water column. This cold water intrusion into the bay causes isotherms to shoal toward the surface and delivers subthermocline waters to shallow reaches of the bay, representing a mechanism for small‐scale upwelling. When the local winds relax, the warm water mass advects back into the bay in the form of a buoyant plume front. Local diurnal winds are expected to play an important role in nearshore dynamics and local upwelling in other small coastal embayments with important implications for various biological and ecological processes

Aprovechamiento del bagazo de piña para obtener celulosa y bioetanol

Actualmente se están buscando nuevas alternativas energéticas a partir de biomasa, recursos renovables y desechos agroindustriales, para desarrollar nuevas tecnologías y procesos en la obtención de biocombustibles. El objetivo fue obtener celulosa y bio-etanol del bagazo de piña (desecho agrícola). El aprovechamiento de este bagazo evitará el consumo de cultivos destinados a la alimentación, evitando el uso excesivo de tierras y el empleo de residuos orgánicos agroindustriales. Además, el producto obtenido tiene un valor agregado y podría convertirse en un beneficio para los productores de piña. La finalidad fue estudiar un proceso para extraer celulosa del bagazo de piña, y mediante hidrólisis ácida de celulosa y bagazo se obtuvo glucosa. Esta glucosa se neutralizó a pH de 5 y se realizó la fermentación en un medio anaeróbico, utilizando el microorganismo Saccharomyces cerevisiae, variando tiempos de fermentación (36, 40, 48 y 72 h) y manteniendo la temperatura a 30ºC. La celulosa obtenida presentó una conversión del 60% y mediante FTIR se corroboró que la celulosa fue tipo II. Se obtuvo bio-etanol mediante destilación, presentando un rendimiento del 35% con bagazo y del 57% con celulosa con un tiempo de fermentación de 48 y 72 h, respectivamente

Global Rebalancing of Cellular Resources by Pleiotropic Point Mutations Illustrates a Multi-scale Mechanism of Adaptive Evolution

Pleiotropic regulatory mutations affect diverse cellular processes, posing a challenge to our understanding of genotype-phenotype relationships across multiple biological scales. Adaptive Laboratory Evolution (ALE) allows for such mutations to be found and characterized in the context of clear selection pressures. Here, several ALE-selected single-mutation variants in Escherichia coli's RNA polymerase (RNAP) are detailed using an integrated multi-scale experimental and computational approach. While these mutations increase cellular growth rates in steady environments, they reduce tolerance to stress and environmental fluctuations. We detail structural changes in the RNAP that rewire the transcriptional machinery to rebalance proteome and energy allocation towards growth and away from several hedging and stress functions. We find that while these mutations occur in diverse locations in the RNAP, they share a common adaptive mechanism. In turn, these findings highlight the resource allocation tradeoffs organisms face and suggest how the structure of the regulatory network enhances evolvability