School administrator preparation in Baja California

A team of US and Mexican researchers used focus groups to determine challenges faced by rural school directors who worked in isolated, poor communities. They had no preparation before becoming directors. Their stories express frustration with teachers who do not come to school on time and are not committed to education. Yet the directors throw themselves into their work and persist over the years. They ask for training in how to work with teachers, and they bring qualities of idealism and persistence to their work. The profiles of the directors suggest a changing dynamic on Hofstede's (2001) cultural dimension

A comparative study on the passivation and localized corrosion of α- and β-brass in borate buffer solutions containing sodium chloride—II. X-ray photoelectron and Auger electron spectroscopy data

The composition of corrosion layers formed on α-, β- and (α + β)-brass anodized in the passive region in borate-boric acid buffer and 0.5 M NaCl + borate-boric acid buffer (pH 9) was studied comparatively by X-ray photo-electron and Auger electron spectroscopy. Passivation of brass in both solutions involves the formation of a complex passive layer consisting of ZnO and Cu2O. In both solutions, the ZnO electroformation results in a dezincification so that a thin Cu rich layer is formed at the alloy/metal oxide interface. Passive layer composition and dezincification of the alloy surface explain the localized corrosion resistance of brass as compared to polycrystalline Cu and Zn.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Procedencia del material pétreo de los molinos de los yacimientos Cogotas I (Bronce Medio y Tardío) de la Cuenca del Duero y modelos consecuentes de flujo

The source provenance of twelve hand grindstones of Cogotian sites from the sedimentary Duero Basin was characterized using petrographic, mineralogical and geochemical criteria, according to an operational process previously proposed. Many of the provenances were determined after trace-element normalized diagrams and comparative diagrams with respect to available data from potential source areas. This methodology confirms that the geochemical signature can be seen as an archaeological fingerprint which allows the identification of facies or rock sub-types from the established source areas. Granite sources are the commonest provenance, although granodiorite, orthogneisses and sandstone are also involved, all of them belonging to the Variscan Basement. One of these source areas includes copper minerals, which could have been used for metallurgical purposes. Probably, since the early phase of Cogotas I, the principle of least effort no longer was a guiding force to boost the supply of material. The archaeological sites experienced a long-distance raw material supply in crossed directions, according to the established sources areas, indicating a dense network of connections between the commnunities of the region at a hecto-kilometric scale.Se ha estudiado la procedencia del material pétreo de doce molinos de diferentes yacimientos cogotenses de la Cuenca del Duero. Utilizando una marcha metodológica previa, se alcanza una caracterización petrográfica, mineralógica y geoquímica del material, incluyendo el tratamiento de elementos traza mediante diagramas de normalización y comparación con datos disponibles de áreas fuente potenciales. Esto ha permitido, en muchos casos, la identificación de áreas fuente locales ya que la signatura geoquímica representa una huella arqueológica fidedigna de las facies o subtipos de rocas implicadas. La mayoría de las áreas fuente identificadas son graníticas, existiendo también granodioritas, gneises y areniscas, todas ellas pertenecientes al basamento varisco. Una de estas áreas incluye minerales de cobre, eventualmente aprovechables para metalurgia. Probablemente, ya desde la fase inicial de Cogotas I dejó de regir el principio del mínimo esfuerzo en el aprovisionamiento del material. El suministro de materias primas a los yacimientos arqueológicos es de carácter lejano y en direcciones cruzadas, de acuerdo con las áreas fuente establecidas, indicando una densa red de conexiones entre las comunidades de la región a escala hectokilométric

Decisiones estratégicas y de alta dirección para la empresa Baldwin

El presente reporte de obtención de grado tiene como finalidad demostrar los conocimientos obtenidos en la maestría de administración de empresas, a través de un análisis detallado de desempeño de la empresa Baldwin de la cual los autores de este trabajo formaron el equipo directivo, en el simulador de negocios Capstone durante de ocho años de operación. El primer capítulo contiene el marco teórico, donde se encuentran teorías relacionadas con la planeación, desarrollo e implementación de una estrategia, modelos de negocios y liderazgo que permiten a las empresas ser exitosas en cualquier industria. Además, se citan diversos casos de éxito de empresas reales, donde se demuestra que la adecuada incorporación de estos conceptos ayuda alcanzar objetivos a largo plazo. El segundo capítulo expone el funcionamiento del simulador Capstone, las condiciones de la industria, los segmentos, los clientes y la competencia en general. Así mismo, se plantea la estrategia general de la empresa Baldwin, su filosofía empresarial y las diferentes tácticas por departamento. Los capítulos comprendidos del tres al seis evidencian los resultados obtenidos por la empresa en los años 2021 a 2028, analizando de manera detallada cuales fueron las tácticas por área y los desaciertos que implementó la compañía a través de los ocho años. Por último, el capítulo siete indica las conclusiones y enseñanzas generales por parte de cada uno de los integrantes del equipo que dejó el simulador y la maestría. Este trabajo es reflejo de las habilidades gerenciales, de los integrantes del equipo, ya que cada uno tenía a su cargo un área, aplicando diversos conocimientos adquiridos durante el MBA y sus respectivas trayectorias laborales.ITESO, A.C

Paediatricians provide higher quality care to children and adolescents in primary care: A systematic review

Aim: The number of primary care paediatricians is decreasing in Europe without a justifiable reason. We aimed to compare the clinical practice of paediatricians and family doctors attending children and adolescents in primary care. Methods: MEDLINE, Embase, CENTRAL, TRIP and Google Scholar were searched from December 2008 to February 2018. No language or study design restrictions were applied. Three reviewers assessed eligibility of the studies. Seven pairs of reviewers performed the data extraction and assessed the methodological quality independently. Discrepancies were resolved by consensus. Results: Fifty-four, out of 1150 studies preselected, were included. We found that paediatricians show more appropriate pharmacology prescription patterns for the illness being treated; they achieve higher vaccination rates and have better knowledge of vaccines and fewer doubts about vaccine safety; their knowledge and implementation of different screening tests are better; they prescribe psychoactive drugs more cautiously and more in line with current practice guidelines; their evaluation and treatment of obesity and lipid disorders follow criteria more consistently with current clinical practice guidelines; and they perform fewer diagnostic test, show a more suitable use of the test and request fewer referrals to specialists. Conclusion: According to published data, in developed countries, paediatricians provide higher quality care to children than family doctors

A comparative study on the passivation and localized corrosion of α- and β-brass in borate buffer solutions containing sodium chloride : II. X-ray photoelectron and Auger electron spectroscopy data

The composition of corrosion layers formed on α-, β- and (α + β)-brass anodized in the passive region in borate-boric acid buffer and 0.5 M NaCl + borate-boric acid buffer (pH 9) was studied comparatively by X-ray photo-electron and Auger electron spectroscopy. Passivation of brass in both solutions involves the formation of a complex passive layer consisting of ZnO and Cu2O. In both solutions, the ZnO electroformation results in a dezincification so that a thin Cu rich layer is formed at the alloy/metal oxide interface. Passive layer composition and dezincification of the alloy surface explain the localized corrosion resistance of brass as compared to polycrystalline Cu and Zn.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

A machine learning approach to personalized predictors of dyslipidemia: a cohort study

IntroductionMexico ranks second in the global prevalence of obesity in the adult population, which increases the probability of developing dyslipidemia. Dyslipidemia is closely related to cardiovascular diseases, which are the leading cause of death in the country. Therefore, developing tools that facilitate the prediction of dyslipidemias is essential for prevention and early treatment.MethodsIn this study, we utilized a dataset from a Mexico City cohort consisting of 2,621 participants, men and women aged between 20 and 50 years, with and without some type of dyslipidemia. Our primary objective was to identify potential factors associated with different types of dyslipidemia in both men and women. Machine learning algorithms were employed to achieve this goal. To facilitate feature selection, we applied the Variable Importance Measures (VIM) of Random Forest (RF), XGBoost, and Gradient Boosting Machine (GBM). Additionally, to address class imbalance, we employed Synthetic Minority Over-sampling Technique (SMOTE) for dataset resampling. The dataset encompassed anthropometric measurements, biochemical tests, dietary intake, family health history, and other health parameters, including smoking habits, alcohol consumption, quality of sleep, and physical activity.ResultsOur results revealed that the VIM algorithm of RF yielded the most optimal subset of attributes, closely followed by GBM, achieving a balanced accuracy of up to 80%. The selection of the best subset of attributes was based on the comparative performance of classifiers, evaluated through balanced accuracy, sensitivity, and specificity metrics.DiscussionThe top five features contributing to an increased risk of various types of dyslipidemia were identified through the machine learning technique. These features include body mass index, elevated uric acid levels, age, sleep disorders, and anxiety. The findings of this study shed light on significant factors that play a role in dyslipidemia development, aiding in the early identification, prevention, and treatment of this condition

The Galaxy Activity, Torus, and Outflow Survey (GATOS): III. Revealing the inner icy structure in local active galactic nuclei

We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to use subarcsecond angular resolution data of local obscured AGN to investigate the nuclear mid-IR absorption bands with a wide wavelength coverage (4.9–28.1 μm). All the nuclei show the 9.7 μm silicate band in absorption. We compare the strength of the 9.7 and 18 μm silicate features with torus model predictions. The observed silicate features are generally well explained by clumpy and smooth torus models. We report the detection of the 6 μm dirty water ice band (i.e., a mix of water and other molecules such as CO and CO2) at subarcsecond scales (∼0.26″ at 6 μm; inner ∼50 pc) in a sample of local AGN with different levels of nuclear obscuration in the range log NHX-Ray (cm−2)∼22 − 25. We find good correlation between the 6 μm water ice optical depths and NHX-Ray. This result indicates that the water ice absorption might be a reliable tracer of the nuclear intrinsic obscuration in AGN. The weak water ice absorption in less obscured AGN (log NHX-ray (cm−2)≲23.0 cm−2) might be related to the hotter dust temperature (> TsubH2O ∼ 110 K) expected to be reached in the outer layers of the torus due to their more inhomogeneous medium. Our results suggest it might be necessary to include the molecular content, such as H2O, aliphatic hydrocarbons (CH−), and more complex polycyclic aromatic hydrocarbon (PAH) molecules, in torus models to better constrain key parameters such as the torus covering factor (i.e., nuclear obscuration)