Properties of ultra-cool dwarfs with Gaia. An assessment of the accuracy for the temperature determination

We aimed to assess the accuracy of the Gaia teff and logg estimates as derived with current models and observations. We assessed the validity of several inference techniques for deriving the physical parameters of ultra-cool dwarf stars. We used synthetic spectra derived from ultra-cool dwarf models to construct (train) the regression models. We derived the intrinsic uncertainties of the best inference models and assessed their validity by comparing the estimated parameters with the values derived in the bibliography for a sample of ultra-cool dwarf stars observed from the ground. We estimated the total number of ultra-cool dwarfs per spectral subtype, and obtained values that can be summarised (in orders of magnitude) as 400000 objects in the M5-L0 range, 600 objects between L0 and L5, 30 objects between L5 and T0, and 10 objects between T0 and T8. A bright ultra-cool dwarf (with teff=2500 K and \logg=3.5 will be detected by Gaia out to approximately 220 pc, while for teff=1500 K (spectral type L5) and the same surface gravity, this maximum distance reduces to 10-20 pc. The RMSE of the prediction deduced from ground-based spectra of ultra-cool dwarfs simulated at the Gaia spectral range and resolution, and for a Gaia magnitude G=20 is 213 K and 266 K for the models based on k-nearest neighbours and Gaussian process regression, respectively. These are total errors in the sense that they include the internal and external errors, with the latter caused by the inability of the synthetic spectral models (used for the construction of the regression models) to exactly reproduce the observed spectra, and by the large uncertainties in the current calibrations of spectral types and effective temperatures.Comment: 18 pages, 17 figures, accepted by Astronomy & Astrophysic

Aprendizaje colaborativo en entornos virtuales en el desarrollo de competencias de parasitología médica en estudiantes de medicina humana de Ica, 2022

Para esta investigación se planteó como objetivo general: Determinar la influencia del aprendizaje colaborativo en entornos virtuales en el desarrollo de competencias en parasitología médica en los estudiantes en una Escuela de Medicina Humana de Ica, 2022. La investigación fue cuantitativa, longitudinal, de diseño correlacional y causal. La muestra estuvo conformada por 266 estudiantes del cuarto semestre. Se desarrolló un modelo de aprendizaje mediante del trabajo colaborativo en una plataforma virtual, aplicando un pre y post test. El grado de confiabilidad de los instrumentos fue terminada con la prueba de Alfa de Cronbach 0,97 y su aprobación por juicio de expertos. Se concluye aceptando la hipótesis general alterna con un nivel de significancia del 0,000 < 0,05 determinando que el aprendizaje colaborativo en entornos virtuales influye en el desarrollo de competencias en parasitología médica. Para las hipótesis específicas tenemos que: la interdependencia positiva (p valor 0,03), la responsabilidad individual y en equipo (p valor 0,04), la interacción estimuladora (p valor 0,00), la gestión interna del equipo (p valor 0,33) y la evaluación interna del equipo (p valor 0,01), influyen significativamente en el desarrollo de competencias en parasitología médica aplicando como estrategia de aprendizaje colaborativo en entornos virtuales

La importancia del coaching en el desarrollo de las habilidades blandas del personal de la empresa Marcimex en la ciudad de Trujillo año 2016

El presente estudio se ha realizado con el propósito de determinar si es importante el coaching en el desarrollo de las habilidades blandas del personal de la empresa Marcimex en la ciudad de Trujillo. El problema formulado para la investigación fue: ¿Es importante el coaching en el desarrollo de las habilidades blandas del personal de la empresa Marcimex en la ciudad de Trujillo? Y se tuvo como hipótesis: Si es importante el coaching en el desarrollo de habilidades blandas del personal de la empresa Marcimex en la ciudad de Trujillo. Como objetivos específicos tenemos: Identificar los indicadores que afectan al coaching de la empresa Marcimex en la ciudad de Trujillo, determinar las habilidades blandas que presentan actualmente el personal de la empresa Marcimex, establecer la motivación en el personal de la empresa Marcimex en la ciudad de Trujillo. La población sujeta a estudio estuvo conformada por 100 personas que laboran en la empresa Marcimex y por el gerente de la tienda en Trujillo. Al ser una población pequeña se considera la población como muestra. El diseño de investigación utilizado fue descriptivo simple, en cuanto a las técnicas e instrumentos de recolección de datos se utilizó la encuesta y la entrevista. La conclusión a la que se llego fue: que hay evidencia suficiente para demostrar que si es importante el coaching en el desarrollo de habilidades blandas del personal de la empresa Marcimex en la ciudad de Trujillo.The present study was carried out with the purpose of determining if coaching is important in the development of the soft skills of the staff of the company Marcimex in the city of Trujillo The problem formulated for the research was: Is development coaching important Of the soft skills of the staff of the company Marcimex in the city of Trujillo? And it was hypothesized: If coaching is important in the development of soft skills of the staff of the company Marcimex in the city of Trujillo. As specific objectives we have: Identify the indicators that affect the coaching of the company Marcimex in the city of Trujillo, determi ne the soft skills that currently present the staff of the company Marcimex, establish the motivation in the staff of the company Marcimex in the city of Trujillo. The population subject to study was made up of 100 people who work in the company Marcimex and the manager of the store in Trujillo. Being a small population is considered the population as a sample. The research design used was descriptive simple, as far as the techniques and instruments of data collection were used the survey and the interview. The conclusion reached was: that there is sufficient evidence to show that if coaching is important in the development of soft skills of the staff of the Marcimex company in the city of TrujilloTesi

Branding como estrategia de creación de valor en una empresa de prestación de servicios, Lima 2022

El branding en las organizaciones supone una serie de actividades que muchos microempresarios olvidan; por ello, el presente estudio tuvo como objetivo determinar la influencia del branding en la creación de valor de una empresa de prestación de servicios. En la cual se muestra como una herramienta de diferenciación en el mercado, ayudando a crear confianza en los clientes; el estudio fue de enfoque cuantitativo, de tipo aplicativo de nivel correlacional causal, de diseño no experimental transversal, la población fue de 510 pacientes de la empresa según el registro en su base de datos y se trabajó con la muestra probabilística de 220 clientes. Los instrumentos que se utilizaron fueron cuestionarios, los cuales gozaron de validación por expertos, análisis factorial y modelos estructurales SEM. Se comprobó que el branding influye en la creación de valor de una empresa de prestación de servicio, los valores que se obtuvieron fueron: en la prueba chi cuadrado 2=sig.0.000, (p<0.05) y Nagelkerke (0.656), demostrando que el branding influye significativamente en un 65.6% la creación de valor de una empresa de prestación de servicios

Evidence Against a Direct Antimicrobial Role of H2O2 in the Infection of Plants by Erwinia chrysanthemi

We have investigated the role of bacterial resistance to oxidative stress in pathogenesis. The oxyR gene from the pathogenic bacterium Erwinia chrysanthemi has been characterized. It is closely related to that found in Escherichia coli (88% overall amino acid identity). An E. chrysanthemi oxyR mutant strain was constructed by marker exchange. After induction with a sublethal dose of H2O2, this mutant was more sensitive to H2O2 and showed reduced levels of catalase and glutathione reductase activities, compared with the wild type. The oxyR mutant was unable to form individual colonies on agar plates unless catalase was added exogenously. However, it retained full virulence in potato tubers and tobacco leaves. These results suggest that the host-produced H2O2 has no direct antimicrobial effect on the interaction of E. chrysanthemi with the two plant species

Brenneria quercina and Serratia spp. isolated from Spanish oak trees: molecular characterization and PCR development

Brenneria quercina has been reported as one of the causal agents of oak decline in Spain. To investigate the bacterial variability of this pathogen from different Spanish oak forests, a collection of 38 bacterial isolates from seven geographic locations and from different oak species was analysed by sequencing 16S rDNA and rep-PCR fingerprinting. All Spanish isolates of B. quercina were grouped by rep-PCR into a homogenous cluster that differed significantly from B. quercina reference strains from California. 16S rDNA analysis revealed that 34 out of 38 isolates were Brenneria . However, four isolates belonged to the genus Serratia , suggesting that this bacterium could cause cankers in oak trees. The information obtained by rep-PCR fingerprint analysis was used to develop PCR primers for the sensitive and specific detection of B. quercina from infected plant tissues. Pathogenicity tests performed with Brenneria and Serratia isolates showed that both were able to grow and cause cankers in oak trees

ROBÓTICA COMO FERRAMENTA DE INCLUSÃO TECNOLÓGICA

Este artigo discute as contribuições que projetos de extensão envolvendo robótica podem trazer para o processo de ensino-aprendizagem e apresenta uma abordagem acessível para a sua utilização a partir da construção de um robô de baixo custo não baseado em sistemas eletrônicos. Ao final, são apresentados resultados de implementações já realizadas pelos autores

A collaboratively derived environmental research agenda for Galapagos

Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation. This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced. </jats:p

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity