Isomerization Mechanism in Hydrazone-Based Rotary Switches: Lateral Shift, Rotation, or Tautomerization?

Two intramolecularly hydrogen-bonded arylhydrazone (aryl = phenyl or naphthyl) molecular switches have been synthesized, and their full and reversible switching between the E and Z configurations have been demonstrated. These chemically controlled configurational rotary switches exist primarily as the E isomer at equilibrium and can be switched to the protonated Z configuration (Z-H^+) by the addition of trifluoroacetic acid. The protonation of the pyridine moiety in the switch induces a rotation around the hydrazone C═N double bond, leading to isomerization. Treating Z-H^+ with base (K_(2)CO_3) yields a mixture of E and “metastable” Z isomers. The latter thermally equilibrates to reinstate the initial isomer ratio. The rate of the Z → E isomerization process showed small changes as a function of solvent polarity, indicating that the isomerization might be going through the inversion mechanism (nonpolar transition state). However, the plot of the logarithm of the rate constant k vs the Dimroth parameter (E_T) gave a linear fit, demonstrating the involvement of a polar transition state (rotation mechanism). These two seemingly contradicting kinetic data were not enough to determine whether the isomerization mechanism goes through the rotation or inversion pathways. The highly negative entropy values obtained for both the forward (E → Z-H^+) and backward (Z → E) processes strongly suggest that the isomerization involves a polarized transition state that is highly organized (possibly involving a high degree of solvent organization), and hence it proceeds via a rotation mechanism as opposed to inversion. Computations of the Z ↔ E isomerization using density functional theory (DFT) at the M06/cc-pVTZ level and natural bond orbital (NBO) wave function analyses have shown that the favorable isomerization mechanism in these hydrogen-bonded systems is hydrazone–azo tautomerization followed by rotation around a C–N single bond, as opposed to the more common rotation mechanism around the C═N double bond

Software lliure aplicat a un institut

Aquest projecte intenta donar una alternativa al software privatiu, fent servir el software lliure, i per aconseguir aquest objectiu es crea una distribució GNU/Linux adaptada a les necessitats del institut IES Sabadell. També es realitza un petit estudi dels dos tipus de software, lliure i privatiu, en que es mostrà la historia, tipus de llicències, models de negoci i les avantatges que tenen.Este proyecto intenta dar una alternativa al software privativo, usando el software libre, y para conseguir este objetivo se crea una dis-tribución GNU / Linux adaptada a las necesidades del instituto IES Sa-badell. También se realizó un pequeño estudio de los dos tipos de software, li-bre y privativo, en que se mostró la historia, tipos de licencias, modelos de negocio y las ventajas que tienen.This project aims to provide an alternative to proprietary sof-tware, using free software, and to achieve this target creates a distribu-tion GNU / Linux tailored to the needs of the institute IES Sabadell. We also performed a small study of two types of software free and pro-prietary, see the history, types of licenses, business models and the advantages they have

Recovering the real-space correlation function from photometric redshift surveys

Measurements of clustering in large-scale imaging surveys that make use of photometric redshifts depend on the uncertainties in the redshift determination. We have used light-cone simulations to show how the deprojection method successfully recovers the real space correlation function when applied to mock photometric redshift surveys. We study how the errors in the redshift determination affect the quality of the recovered two-point correlation function. Considering the expected errors associated to the planned photometric redshift surveys, we conclude that this method provides information on the clustering of matter useful for the estimation of cosmological parameters that depend on the large scale distribution of galaxies.Comment: 11 pages, 8 figures. Accepted for publication in MNRA

Estudio de plantas alimenticias consumidas por la población en el Área Metropolitana de San Salvador (AMSS) y municipios aledaños: Fase I

Malnutrition is one of the characteristics of "Iow- and middle-income" countries as El Salvador; but poverty is not the only cause of the problem, since malnutrition can also be explained taking into account variables such as culture, that influences people to sells their nutritious foods and to purchase other with less or no nutritional value, indueed by propaganda of social media. Aecording to Food and Agriculture Organitation (FAO) El Salvador ranks tenth in Latin America in the prevalence rote of obesity in adults over 20 years with a 27.0 %, this inereases the risk of ehronic diseases sueh as hypertensiol1, diabetes, cancer; among others, having an impaet on the quality oflife ofindividuals (1). In order to positively influence to salve this problem, there have been important hut insufficient contributions to the reseue of the edible plants in the region. In this study, a survey was conducted in the AMSS and surrounding municipalities, obtaining a total of 91 plants with their common names - 45 exotic, 39 native, and 4 naturalized-, ofwhich 88 could be identified taxonomically and 3 could not be I identified beca use no references in the different databases were found. Also the results were compared with other listings, [inding 7 species that have notyet been reported. Finally the ten species with the highest frequency ofuse and their nutritional value, coincidentally evaluated species higher nutritional value are the same as reported a higher frequency of use, which are: Solanum nigrum -blackberry- (22.20 %), Crotalaria longirostrata -chipilín- (18.33 %), and Spinacia oleracea, -spinach- (12.20 %).La desnutrición es una de las características de los "países de bajo y mediano ingreso" como El Salvador; pero la pobreza no es la única causa de este problema. La desnutrición también puede explicarse tomando en cuenta variables como la cultura, que incide para que las personas comercialicen sus alimentos nutritivos y compren otros de menor o ningún valor nutricional, inducidos por la propaganda de los medios de comunicación social. Según datos de la Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO), El Salvador ocupa el décimo lugar en América Latina en el Índice de prevalencia de obesidad en adultos mayores de 20 años, con un 27 %, esto aumenta el riesgo de padecer enfermedades crónicas (1).Con el propósito de incidir positivamente para resolver esta problemática, se han realizado aportes importantes pero insuficientes en el rescate de las plantas comestibles en la región. En el presente estudio se realizó una encuesta en el AMSS y municipios aledaños, obteniendo un total de 91 plantas con sus nombres comunes, de las cuales se pudieron identificar taxonómicamente 88, y 3 no pudieron ser identificadas debido a que no se encontraron referencias en los diferentes bancos de datos. Además, se cotejaron los resultados obtenidos con otros listados, encontrando 7 especies que aún no han sido reportadas. Finalmente, se evaluaron las diez especies con mayor frecuencia de uso y su valor nutricional, coincidentemente las especies de mayor valor nutricional son las mismas que reportan una mayor frecuencia de uso, siendo estas: Solanum nigrum -mora- (22.20 %), Crotalaria longirostrata -chipilín- (18.33 %), Y Spinacia oleracea -espinaca- (12.20 %)

Estudio de plantas alimenticias consumidas por la población en el Área Metropolitana de San Salvador (AMSS) y municipios aledaños. Fase I

La desnutrición es una de las características de los “países de bajo y mediano ingreso” como El Salvador; pero la pobreza no es la única causa de este problema. La desnutrición también puede explicarse tomando en cuenta variables como la cultura, que incide para que las personas comercialicen sus alimentos nutritivos y compren otros de menor o ningún valor nutricional,inducidos por la propaganda de los medios de comunicación social. Según datos de la Organización de las Naciones Unidas para la Alimentación y la Agricultura(FAO), El Salvador ocupa el décimo lugar en América Latina en el índice de prevalencia de obesidad en adultos mayores de 20 años,con un 27%, esto aumenta el riesgo de padecer enfermedades crónicas(1). Con el propósito de incidir positivamente para resolver esta problemática, se han realizado aportes importantes pero insuficientes en el rescate de las plantas comestibles en la región. En el presente estudio se realizó una encuesta en el AMSS y municipios aledaños, obteniendo un total de 91 plantas con sus nombres comunes, de las cuales se pudieron identificar taxonómicamente 88, y 3 no pudieron ser identificadas debido a que no se encontraron referencias en los diferentes bancos de datos. Además, se cotejaron los resultados obtenidos con otros listados, encontrando 7 especies que aún no han sido reportadas. Finalmente, se evaluaron las diez especies con mayor frecuencia de uso y su valor nutricional, coincidentemente las especies de mayor valor nutricional son las mismas que reportan una mayor frecuencia de uso, siendo estas: Solanum nigrum- mora–(22.20 %),Crotalaria longirostrata–chipilín(18.33 %), y Spinacia oleracea –espinaca– (12.20 %)

Alternativa de tratamiento de aguas residuales para hoteles campestres en el departamento de Santander

Analizando la problemática por la cual los sistemas naturales y la biodiversidad de algunos municipios del departamento Santander están pasando a causa de las aguas servidas en el ejercicio y desarrollo de las actividades hoteleras rurales que impulsan la economía de estas zonas, se han presentado diferentes afectaciones a las fuentes hídricas donde se vierten los residuos producidos por dichos establecimientos; los principales vertimientos de contaminantes se observa en las quebradas, ya es alerta para las autoridades ambientales quienes tienen la obligación de proceder para mitigar los impactos y daños ambientales, la mayoría de estos establecimientos no cuentan con una infraestructura adecuada para el manejo de dichas aguas servidas, con la consecuencia de convertirse en un potencial foco de contaminación para los cuerpos de aguas y suelos. Traen diversas afectaciones en la salud de las comunidades aledañas, ecosistemas y especies de animales que se abastecen de este recurso, se busca mejorar la calidad del agua y reducir la contaminación del recurso hídrico en diferentes zonas de Colombia buscando una alternativa de tratamiento para las aguas residuales del gremio hotelero rural. Con base a esto se determinará una buena alternativa para mejorar las condiciones de calidad de efluentes con un tratamiento de estas aguas servidas antes de ser vertidas.Universidad Libre Seccional Socorro -- Facultad de Ingeniería y ciencias agropecuarias --Especialización en gestión ambientalAnalyzing the problem by which the natural systems and biodiversity of some municipalities of the Santander department are experiencing sewage in the exercise and development of rural hotel activities that drive the economy of these areas, different effects have been presented to the water sources where the waste produced by said establishments is dumped; The main dumping of pollutants is observed in the streams, it is already an alert for the environmental authorities who have the obligation to proceed to mitigate environmental impacts and damages, most of these establishments do not have adequate infrastructure for the management of said sewage , with the consequence of becoming a potential source of contamination for water bodies and soils. They bring various effects on the health of the surrounding communities, ecosystems and animal species that are supplied with this resource, they seek to improve the quality of the water and reduce the contamination of the water resource in different areas of Colombia, seeking an alternative treatment for the waters residuals of the rural hotel union. Based on this, a good alternative will be determined to improve effluent quality conditions with a treatment of these sewage before being discharged

Sentiment Analysis on Twitter: Role of Healthcare Professionals in the Global Conversation during the AstraZeneca Vaccine Suspension

The vaccines against COVID-19 arrived in Spain at the end of 2020 along with vaccination campaigns which were not free of controversy. The debate was fueled by the adverse effects following the administration of the AstraZeneca-Oxford (AZ) vaccine in some European countries, eventually leading to its temporary suspension as a precautionary measure. In the present study, we analyze the healthcare professionals’ conversations, sentiment, polarity, and intensity on social media during two periods in 2021: the one closest to the suspension of the AZ vaccine and the same time frame 30 days later. We also analyzed whether there were differences between Spain and the rest of the world. Results: The negative sentiment ratio was higher (U = 87; p = 0.048) in Spain in March (Med = 0.396), as well as the daily intensity (U = 86; p = 0.044; Med = 0.440). The opposite happened with polarity (U = 86; p = 0.044), which was higher in the rest of the world (Med = −0.264). Conclusions: There was a general increase in messages and interactions between March and April. In Spain, there was a higher incidence of negative messages and intensity compared to the rest of the world during the March period that disappeared in April. Finally, it was found that the dissemination of messages linked to negative emotions towards vaccines against COVID-19 from healthcare professionals contributed to a negative approach to primary prevention campaigns in the middle of the pandemicThis research was funded by Fundación Banco Santander and Fundación Alfonso X el Sabio, grant number 1012031. Partial funding for open access charge: Universidad de Málag

Multi-station volcano tectonic earthquake monitoring based on transfer learning

Introduction: Developing reliable seismic catalogs for volcanoes is essential for investigating underlying volcanic structures. However, owing to the complexity and heterogeneity of volcanic environments, seismic signals are strongly affected by seismic attenuation, which modifies the seismic waveforms and their spectral content observed at different seismic stations. As a consequence, the ability to properly discriminate incoming information is compromised. To address this issue, multi-station operational frameworks that allow unequivocal real-time management of large volumes of volcano seismic data are needed.Methods: In this study, we developed a multi-station volcano tectonic earthquake monitoring approach based on transfer learning techniques. We applied two machine learning systems—a recurrent neural network based on long short-term memory cells (RNN–LSTM) and a temporal convolutional network (TCN)—both trained with a master dataset and catalogue belonging to Deception Island volcano (Antarctica), as blind-recognizers to a new volcanic environment (Mount Bezymianny, Kamchatka; 6 months of data collected from June to December 2017, including periods of quiescence and eruption).Results and discussion: When the systems were re-trained under a multi correlation-based approach (i.e., only seismic traces detected at the same time at different seismic stations were selected), the performances of the systems improved substantially. We found that the RNN-based system offered the most reliable recognition by excluding low confidence detections for seismic traces (i.e., those that were only partially similar to those of the baseline). In contrast, the TCN-based network was capable of detecting a greater number of events; however, many of those events were only partially similar to the master events of the baseline. Together, these two approaches offer complementary tools for volcano monitoring. Moreover, we found that our approach had a number of advantages over the classical short time average over long time-average (STA/LTA) algorithm. In particular, the systems automatically detect VTs in a seismic trace without searching for optimal parameter settings, which makes it a portable, scalable, and economical tool with relatively low computational cost. Moreover, besides obtaining a preliminary seismic catalog, it offers information on the confidence of the detected events. Finally, our approach provides a useful tentative label for subsequent analysis carried out by a human operator. Ultimately, this study contributes a new framework for rapid and easy volcano monitoring based on temporal changes in monitored seismic signals