Hints against the cold and collisionless nature of dark matter from the galaxy velocity function

The observed number of dwarf galaxies as a function of rotation velocity is significantly smaller than predicted by the standard model of cosmology. This discrepancy cannot be simply solved by assuming strong baryonic feedback processes, since they would violate the observed relation between maximum circular velocity ($v_{\rm max}$) and baryon mass of galaxies. A speculative but tantalising possibility is that the mismatch between observation and theory points towards the existence of non-cold or non-collisionless dark matter (DM). In this paper, we investigate the effects of warm, mixed (i.e warm plus cold), and self-interacting DM scenarios on the abundance of dwarf galaxies and the relation between observed HI line-width and maximum circular velocity. Both effects have the potential to alleviate the apparent mismatch between the observed and theoretical abundance of galaxies as a function of $v_{\rm max}$. For the case of warm and mixed DM, we show that the discrepancy disappears, even for luke-warm models that evade stringent bounds from the Lyman-$\alpha$ forest. Self-interacting DM scenarios can also provide a solution as long as they lead to extended ($\gtrsim 1.5$ kpc) dark matter cores in the density profiles of dwarf galaxies. Only models with velocity-dependent cross sections can yield such cores without violating other observational constraints at larger scales.Comment: Matches published versio

Application of the modified Delphi method for the validation of a questionnaire on the incorporation of ICT in teaching practice

La incorporación de las TIC en los escenarios educativos representa un reto para los docentes en el sentido de auto orientarse en la forma en la que utilizan estas herramientas en su práctica áulica e incluso en sus actividades cotidianas, cabe mencionar que estas formas de impactan directamente en la formación de los estudiantes, en la manera de conducirse a lo largo del proceso enseñanza-aprendizaje, así como en su formación personal. En este artículo se documenta el proceso de diseño y validación de un cuestionario para analizar cómo estos docentes están incorporando las TIC desde el referente teórico de la práctica docente. Para tal fin, se utilizó una variación del Método Delphi que permitió una respuesta eficiente de los expertos seleccionados para la validación. Como resultado se logró obtener un cuestionario con una escala tipo Likert en donde se refleja la experiencia profesional de expertos de distintas universidades para otorgar elaborar un cuestionario con claridad en las preguntas e ítems pertinentesThe incorporation of ICT in educational scenes represents a challenge for teachers in a self-oriented way in which they use those tools in their classroom practice and even in their daily activities. It should be mentioned that these forms of use, make an impact on the formation of the students, in the way they conduct themselves throughout the teaching-learning process, as well as in their personal formation. The purpose of this paper is to document the design and validation process of a questionnaire to analyze how some teachers are incorporating ICT from the theoretical reference of a teaching practice. For this purpose, a variation of the Delphi Method was used, which allowed an efficient response of the experts selected for the validation. As a result, a questionnaire with a Likert-type scale was obtained and the professional experience of teachers from different universities to grant a questionnaire with clarity in the questions and pertinent item

Código de ética y compromiso organizacional en la Municipalidad Distrital de Nuevo Chimbote, 2021

La presente tesis tuvo como objetivo general determinar, la relación que existe entre la aplicación del código de ética de la función pública y compromiso organizacional de la municipalidad, distrital de Nuevo, Chimbote, en el año 2021. Para ello se empleó el tipo de investigación básica, de enfoque cuantitativo, con un diseño no experimental, transversal y correlacional. Empleándose para ello una población muestral conformada por 41 funcionarios a quienes se les aplico la técnica de la encuentra a través de dos instrumentos (cuestionarios) para la recolección de datos compuestos por 19 y 18 ítems respectivamente, validados por tres expertos y sometidos a la prueba de confiabilidad de Alfa de Cronbach con un valor de 0,877 y 0,857, indicando que existe una confiabilidad alta en el instrumento. Se empleó el coeficiente de correlación de Rho de Spearman. determinando que el coeficiente de correlación rxy = 0,820, indica que el grado de relación entre las variables de estudio es positiva de intensidad fuerte. Además, con un nivel de significancia 0,05 el valor de p = 0,000 < 0,05, con lo cual se demuestra que existe relación significativa entre las el código de ética y el compromiso organizacional, afirmándose la hipótesis general

Evaluación del sobreancho en vehículos tipo articulado para infraestructuras viales del Perú

En la presente tesis se ha planteado como problema general: ¿Cuáles son los resultados de la evaluación del sobreancho en vehículos tipo articulado para infraestructuras viales del Perú?, siendo el objetivo general: Evaluar los resultados del sobreancho en vehículos tipo articulado para infraestructuras viales del Perú. Y como hipótesis general: La evaluación del sobreancho presenta resultados eficientes en vehículos tipo articulado para infraestructuras viales del Perú. En la investigación se empleó el método científico, nivel de investigación correlacional, diseño no experimental y el tipo de investigación aplicativo ya que se resuelve un problema real por lo que se realizó una recolección entre los resultados de sobreancho de acuerdo a la norma AASHTO, INVIAS y simulación en el software Vehicle Traking. Afirmando que se identificó al realizar el análisis del sobreancho por la normatividad INVIAS Y AASHTO para el vehículo T3S2 la variación que hay muestran una variación de sobreancho adicional de seguridad mayor al identificado con la simulación a causa de los factores de seguridad generando así sobreanchos mayores que reducen la cantidad de accidentes de tránsito

Another baryon miracle? Testing solutions to the 'missing dwarfs' problem

The dearth of dwarf galaxies in the local universe is hard to reconcile with the large number of low mass haloes expected within the concordance $\Lambda$CDM paradigm. In this paper we perform a systematic evaluation of the uncertainties affecting the measurement of DM halo abundance using galaxy kinematics. Using a large sample of dwarf galaxies with spatially resolved kinematic data we derive a correction to obtain the observed abundance of galaxies as a function of their halo maximum circular velocity from the line-of-sight velocity function in the Local Volume. This estimate provides a direct means of comparing the predictions of theoretical models and simulations (including nonstandard cosmologies and novel galaxy formation physics) to the observational constraints. The new "galactic $V_{max}$" function is steeper than the line-of-sight velocity function but still shallower than the theoretical CDM expectation, showing that some unaccounted physical process is necessary to reduce the abundance of galaxies and/or drastically modify their density profiles compared to CDM haloes. Using this new galactic $V_{max}$ function, we investigate the viability of baryonic solutions such as feedback-powered outflows and photoevaporation of gas from an ionising radiation background. At the 3-$\sigma$ confidence level neither energetic feedback nor photoevaporation are effective enough to reconcile the disagreement. In the case of maximum baryonic effects, the theoretical estimate still deviates significantly from the observations for $V_{max} < 60$ km/s. CDM predicts at least 1.8 times more galaxies with $V_{max} = 50$ km/s and 2.5 times more than observed at $30$ km/s. Recent hydrodynamic simulations seem to resolve the discrepancy but disagree with the properties of observed galaxies with resolved kinematics. (abridged)Comment: 17 pages, 22 figures; major revisions include clarification of the method, expanded comparison with simulations with a new figure, analysis of uncertainties in model as well as pressure support corrections, and a new table with nomenclatur

Complicación que se presenta en los pacientes al tratamiento con heberprot-p en un área de salud

Introduction: diabetes is considered an epidemic in the world. Diabetic foot is a serious health problem in Cuba. Heberprot-p is a novel drug that can solve a medical need not covered worldwide. Objective: to determine the complication that occurred during therapy with heberprot-p. Method: a descriptive longitudinal study was performed in 108 patients treated with heberprot-p in “Manuel Piti Fajardo” Policlinic in Santo Domingo between January 2012 and December 2015, the sample consisted of 14 patients who had a non-satisfactory evolution. The information was obtained by the survey method and through the review of medical records and treatment registration cards. Results: 87% of the patients who received heberprot-p treatment had a satisfactory outcome; of patients with unsatisfactory outcome the main complication was local infection (100%); 64,3% were males and 78,6% were older than 60 years, 64,3% had more than 10 years of diabetes and the most prevalent risk factors were hyperglycemia, overweight and obesity (or both), followed by dyslipidemia and depression, respectively. Conclusions: it was determined that local infection was the most frequent complication and hyperglycemia was the main risk factor.Introducción: la diabetes es considerada una epidemia en el mundo. El pie diabético constituye un serio problema de salud en Cuba. El heberprot-p es un novedoso medicamento que puede solucionar una necesidad médica no cubierta a nivel mundial. Objetivo: determinar la complicación que se presentó durante la terapia con heberprot-p. Método: se realizó en el “Policlínico Manuel Piti Fajardo” de Santo Domingo entre enero de 2012 y diciembre de 2015 un estudio descriptivo de corte longitudinal a los 108 pacientes tratados con heberprot-p, la muestra estuvo conformada por los 14 que tuvieron una evolución no satisfactoria. La información se obtuvo por el método de encuesta y a través de la revisión de las historias clínicas y de las tarjetas de registro de tratamiento. Resultados: de la población estudio el 87% de los pacientes que llevaron tratamiento con heberprot-p tuvieron una evolución satisfactoria; de los pacientes con evolución no satisfactoria la principal complicación fue la infección local (100%); el 64,3% eran del sexo masculino y el 78,6% tenía edad mayor de 60 años, el 64,3% tenían más de 10 años de evolución de la diabetes y los factores de riesgo de mayor prevalencia fueron la hiperglucemia, el sobrepeso y la obesidad (o ambos), seguidos de la dislipidemia y la depresión, respectivamente. Conclusiones: se determinó que la infección local fue la complicación más frecuente y la hiperglucemia el principal factor de riesgo

How Can Vaccines Against Influenza and Other Viral Diseases Be Made More Effective?

A large fraction of the world’s most widespread and problematic pathogens, such as the influenza virus, seem to persist in nature by evading host immune responses by inducing immunity to genetically and phenotypically plastic epitopes (aka antigenic variation). The more recent re-emergence of pandemic influenza A/ H1N1 and avian H5N1 viruses has called attention to the urgent need for more effective influenza vaccines. Developing such vaccines will require more than just moving from an egg-based to a tissueculture–based manufacturing process. It will also require a new conceptual understanding of pathogen–host interactions, as well as new approaches and technologies to circumvent immune evasion by pathogens capable of more genetic variation. Here, we discuss these challenges, focusing on some potentially fruitful directions for future research

Dynamic shear deformation in high purity Fe

The forced shear test specimen, first developed by Meyer et al. [Meyer L. et al., Critical Adiabatic Shear Strength of Low Alloyed Steel Under Compressive Loading, Metallurgical Applications of Shock Wave and High Strain Rate Phenomena (Marcel Decker, 1986), 657; Hartmann K. et al., Metallurgical Effects on Impact Loaded Materials, Shock Waves and High Strain rate Phenomena in Metals (Plenum, 1981), 325-337.], has been utilized in a number of studies. While the geometry of this specimen does not allow for the microstructure to exactly define the location of shear band formation and the overall mechanical response of a specimen is highly sensitive to the geometry utilized, the forced shear specimen is useful for characterizing the influence of parameters such as strain rate, temperature, strain, and load on the microstructural evolution within a shear band. Additionally, many studies have utilized this geometry to advance the understanding of shear band development. In this study, by varying the geometry, specifically the ratio of the inner hole to the outer hat diameter, the dynamic shear localization response of high purity Fe was examined. Post mortem characterization was performed to quantify the width of the localizations and examine the microstructural and textural evolution of shear deformation in a bcc metal. Increased instability in mechanical response is strongly linked with development of enhanced intergranular misorientations, high angle boundaries, and classical shear textures characterized through orientation distribution functions

Caracterización clínica-demográfica y de eventos adversos durante el tratamiento con Heberprot-P

Introduction: Heberprot-P is a novel drug that has come for the reduction of amputation risks; like any drug it is not devoid of adverse events.Objectives: to characterize patients during Heberprot-P treatment according to demographic and clinical variables, as well as to describe adverse events reported during therapy.Methods: a longitudinal study was conducted at the Comprehensive Care Clinic for patients with diabetic foot ulcers at "Policlínico Manuel Piti Fajardo" in Santo Domingo, Villa Clara, between January 2017 and September 2019. The sample was 104 patients who were applied the Heberprot-P. Variables used were: age, sex, Wagner's classification, etiopathogenic classification of the diabetic foot, treatment effectiveness and reported adverse events (frequency, intensity, severity and causality relationship were addressed).Results: females and patients over 60 years old predominated (67.31%). According to Wagner's classification for diabetic foot ulcer, grade 1 prevailed (73.08%), and according to etiopathogenesis, patients with neuroinfective foot prevailed (58.65%). Total effectiveness of treatment was 90.38%. The most frequent adverse events were burning, pain and headache. Adverse events dependent on the mode of administration and the product itself (burning and pain) predominated, mostly of mild intensity and defined causality.Conclusions: the beneficial effect of Heberprot-P in diabetic foot ulcers to achieve granulation was confirmed. Adverse events associated with treatment present similar characteristics to those reported at national and international level.Introducción: el Heberprot-P es un novedoso medicamento que ha llegado para la reducción de los riesgos de amputación; como cualquier medicamento no está desprovisto de eventos adversos.Objetivos: caracterizara los pacientes durante el tratamiento con Heberprot-P de acuerdo a variables demográficas y clínicas, así como describir los eventos adversos informados durante la terapia.Métodos: se realizó en la Consulta de Atención Integral al paciente con úlceras del pie diabéticodel “Policlínico Manuel Piti Fajardo” de Santo Domingo, Villa Clara, un estudio longitudinalentre enero de 2017 y septiembre de 2019. La muestrafue de104 pacientes a los que se les aplicó el Heberprot-P. Se utilizaron las variables: edad, sexo, clasificación de Wagner, clasificación etiopatogénica del pie diabético, efectividad del tratamiento y eventos adversos informados (se trataron la frecuencia, la intensidad, la gravedad y la relación de causalidad).Resultados: predominaron las féminas y los pacientes con más de 60 años (67,31%). Prevalecieron, según la clasificación de Wagner para la úlcera de pie diabético, elgrado 1 (73,08%), y según la etiopatogenia, los pacientes con pie neuroinfeccioso (58,65%).Se apreció una efectividad total del 90,38% al tratamiento. Los eventos adversos más frecuentes fueron el ardor, el dolor y la cefalea. Predominaron los eventos adversos dependientes del modo de administración y del producto en si (ardor y dolor), en su mayoría de intensidad leve y causalidad definida.Conclusiones: se confirmó el efecto beneficioso del Heberprot-P en úlceras de pie diabético para lograr la granulación, los eventos adversos asociados al tratamiento presentan similares características a lo informado a nivel nacional e internacional