Esquemas de registro para alinear imágenes del cerebro

In this paper, the results obtained by the registration process of brain image volumes obtained by magnetic resonance imaging (MRI) and functional magnetic resonance imaging (MRI) using two different computational frameworks are presented. The objective is to compare the performance of each framework, focusing this comparison in the error measurement obtained by brain volumes registration. The comparison involves the intra patient and intra modality (MRI-MRI and fMRI-fMRI) registration. Statistical Parametric Mapping (SPM) and Insight Segmentation and Registration Toolkit (ITK) are chosen as registration frameworks. The proposed methodology considers the data sets generation, test planning, designing test cases, tests execution and evaluating. Finally, these results are analysed. The correspondence between the volumes registered and the target volume using the ITK framework is greater than that obtained with the SPM framework.En este artículo, se presentan los resultados obtenidos por el proceso de registro de los volúmenes de imágenes cerebrales obtenidos por resonancia magnética (MRI) y resonancia magnética funcional (fMRI) utilizando dos marcos computacionales diferentes. El objetivo es comparar el rendimiento de cada marco, enfocando esta comparación en la medición de error obtenida por el registro de volúmenes cerebrales. La comparación involucra el registro intramodal e intramodalidad (MRI-MRI y fMRI-fMRI). El Statistical Parametric Mapping (SPM) y el Insight Segmentation and Registration Toolkit (ITK) se eligen como marcos de registro. La metodología propuesta considera la generación de conjuntos de datos, planificación de pruebas, diseño de casos de prueba, ejecución de pruebas y evaluación. Finalmente, estos resultados son analizados. La correspondencia entre los volúmenes registrados y el volumen objetivo usando el marco ITK es mayor que la obtenida con el marco SPM

Minimal distance vector. A new approach to avoid tip-over on mobile manipulators

Muchas aplicaciones de los sistemas robóticos requieren que el manipulador desarrolle operaciones mientras se encuentra sobre una plataforma móvil,situación que a diferencia de un manipulador robótico fijo, puede tener un comportamiento inestable y quedar operativamente inutilizado por volcamiento, condición última que puede ser a causa del desplazamiento del centro de gravedad del conjunto al encontrarse sobre el nivel de la plataforma de transporte por efecto del peso del manipulador. Se presenta una nueva técnica para evitar la condición de volcado por la utilización del concepto de distancia mínima entre el centro rotacional del manipulador y el arco proyectado por el centro de masa sobre el suelo de tránsito, con el objeto de modificar el centro de gravedad del conjunto por la rotación del manipulador sobre la plataforma. El objetivo final es compensar el momento rotacional a muy baja velocidad por la utilización del concepto de contra-balance por cambio de posición.Many future applications of robotics systems will  require  that  manipulators  perform  operations while  being  carried  by  moving  vehicles.  However,  different from  a  manipulator  fixed  on  the  floor,  such  a  vehicle-mounted mobile manipulator might be unstable or even tip  over,  this condition  may  be  because  the  center  of mass  is  over  the  mobile  platform  by  the manipulator’s weight.  This  paper  presents  a  new  technique  to  avoid tip-over  condition  using  the  concept  of  minimal  distance  between  the  manipulator  rotational  center  and  the projection  mass  center  arc  in  the  soil  with  the  object of modificate the gravity center of the et changing the manipulator rotational position on mobile platform, the final objective is to compensate the rotational moment at low velocity using counter-balance concept

Direccionamiento de la investigación universitaria: aproximación teórica para su análisis

The objective was to develop a theoretical approach to the direction of research in universities. It was a mixed study, with field design and bibliographic support, of an explanatory level, being the specific context the Universidad Nacional Experimental del Táchira, Venezuela. The analysis revealed an academic system determined by the absence of strategic macro-institutional direction of research, relying on expert power (researchers), achievements in productivity and competitiveness. A theoretical approach emerges that is constituted by three dimensions: the strategic nature of the direction, the overall vision of the institutional system, and the power relations among the actors of the system.El objetivo fue desarrollar una aproximación teórica del direccionamiento de la investigación en las universidades. Fue un estudio mixto, con diseño de campo y apoyo bibliográfico, de nivel explicativo, siendo el contexto específico la Universidad Nacional Experimental del Táchira, Venezuela. El análisis reveló un sistema académico determinado por la ausencia de direccionamiento estratégico macro institucional de la investigación, reposando en el poder experto (investigadores), los logros en productividad y competitividad. Emerge una aproximación teórica constituida por tres dimensiones: el carácter estratégico del direccionamiento, la visión de conjunto del sistema institucional, y las relaciones de poder entre los actores del sistema

La gestión logística en las microempresas manufactureras del Estado Táchira, Venezuela.

The objective of the work was to describe the dynamics of logistics management in the manufacturing micro-enterprise of theTáchira State, Venezuela, based on the supply, production and distribution processes. It was a quantitative study, of descriptive level and fielddesign, developed in a sample of 205 micro-enterprises from 10 municipalities of the State, using the technique of the survey through aquestionnaire of 33 items applied in the period January-July 2019. Between The main findings stand out in terms of the supply process, seriousdrawbacks with the availability of raw materials and supplies, the variability in the prices of goods, and the limited opportunity, quantity and diversity of these in the market. Regarding the production process, the development of the planning process was not very assertive, while sales histories prevail before the changing needs of demand; likewise, the low technological level of machinery and equipment is a weakness. Regarding the distribution process, it is limited due to the precariousness of the transport systems themselves, and the difficulties of the external means. As a conclusion, it is considered that in the microenterprises studied, despite the weaknesses found, there are determining elements of the culture of this type of companies, which gives a dynamic character to the management of the supply, production and distribution processes, being able to improve these by starting of an assertive production planning based on the knowledge of the needs of the demand, and of the appropriation of the opportunities in the market and the environment in terms of the strategic obtaining of raw materials and financing, making possible a better and timely process of cateringEl objetivo del trabajo fue describir la dinámica de la gestión logística en la microempresa manufacturera del Estado Táchira, Venezuela, a partir de los procesos de abastecimiento, producción y distribución. Fue un estudio cuantitativo, de nivel descriptivo y diseño de campo, desarrollado en una muestra de 205 microempresas de 10 municipios del Estado, utilizándose la técnica de la encuesta a través de un cuestionario de 33 ítems aplicado en el período enero-julio 2019. Entre los principales hallazgos destacan en cuanto al proceso de abastecimiento, serios inconvenientes con la disponibilidad de materias primas e insumos, la variabilidad en los precios de las mercancías, y la poca oportunidad, cantidad y diversidad de éstos en el mercado. En cuanto al proceso de producción, se encontró el desarrollo poco asertivo del proceso planificador, en tanto prevalecen los históricos de ventas ante las necesidades cambiantes de la demanda; asimismo, es una debilidad el escaso nivel tecnológico de la maquinaria y equipos. Respecto al proceso de distribución, el mismo se ve limitado ante la precariedad de los sistemas propios de transporte, y las dificultades de los medios externos. Como conclusión, se considera que en las microempresas estudiadas pese a las debilidades encontradas, existen elementos determinantes de la cultura de este tipo de empresas lo cual imprime un carácter dinámico a la gestión de los procesos de abastecimiento, producción y distribución, pudiendo mejorar éstos partiendo de una asertiva planificación de la producción con base en el conocimiento de las necesidades de la demanda, y de la apropiación de las oportunidades del mercado y del entorno en cuanto a la obtención estratégica de materias primas y financiamiento, viabilizando un mejor y oportuno proceso de abastecimiento

Logistics management in manufacturing micro-enterprises in Táchira State, Venezuela

El objetivo del trabajo fue describir la dinámica de la gestión logística en la microempresa manufacturera del Estado Táchira, Venezuela, a partir de los procesos de abastecimiento, producción y distribución. Fue un estudio cuantitativo, de nivel descriptivo y diseño de campo, desarrollado en una muestra de 205 microempresas de 10 municipios del Estado, utilizándose la técnica de la encuesta a través de un cuestionario de 33 ítems aplicado en el período enero-julio 2019. Entre los principales hallazgos destacan en cuanto al proceso de abastecimiento, serios inconvenientes con la disponibilidad de materias primas e insumos, la variabilidad en los precios de las mercancías, y la poca oportunidad, cantidad y diversidad de éstos en el mercado. En cuanto al proceso de producción, se encontró el desarrollo poco asertivo del proceso planificador, en tanto prevalecen los históricos de ventas ante las necesidades cambiantes de la demanda; asimismo, es una debilidad el escaso nivel tecnológico de la maquinaria y equipos. Respecto al proceso de distribución, el mismo se ve limitado ante la precariedad de los sistemas propios de transporte, y las dificultades de los medios externos. Como conclusión, se considera que en las microempresas estudiadas pese a las debilidades encontradas, existen elementos determinantes de la cultura de este tipo de empresas lo cual imprime un carácter dinámico a la gestión de los procesos de abastecimiento, producción y distribución, pudiendo mejorar éstos partiendo de una asertiva planificación de la producción con base en el conocimiento de las necesidades de la demanda, y de la apropiación de las oportunidades del mercado y del entorno en cuanto a la obtención estratégica de materias primas y financiamiento, viabilizando un mejor y oportuno proceso de abastecimiento.The objective of the work was to describe the dynamics of logistics management in the manufacturing micro-enterprise of the Táchira State, Venezuela, based on the supply, production and distribution processes. It was a quantitative study, of descriptive leveland field design, developed in a sample of 205 micro-enterprises from 10 municipalities of the State, using the technique of the survey through a questionnaire of 33 items applied in the period January-July 2019. Between The main findings stand out in terms of the supply process, serious drawbacks with the availability of raw materials and supplies, the variability in the prices of goods, and the limited opportunity, quantity and diversity of these in the market. Regarding the production process, the development of the planning process was not very assertive, while sales histories prevail before the changing needs of demand; likewise, the low technological level of machinery and equipment is a weakness. Regarding the distribution process, it is limited due to the precariousness of the transport systems themselves, and the difficulties of the external means. As a conclusion, it is considered that in the microenterprises studied, despite the weaknesses found, there are determining elements of the culture of this type of companies, which gives a dynamic character to the management of the supply, production and distribution processes,being able to improve these by starting of an assertive production planning based on the knowledge of the needs of the demand, andof the appropriation of the opportunities in the market and the environment in terms of the strategic obtaining of raw materials andfinancing, making possible a better and timely process of catering

Guiding actions to control academic stress and during professional practices in nursing students

El presente articulo está orientado a plantear acciones que con- tribuyan a disminuir el estrés académico y durante las prácticas profesionales, presente en estudiantes del último semestre del programa de Enfermería de la UDES, sustentándose para ello en conocer, desde el paradigma cuantitativo, la percepción de los estudiantes sobre los factores relacionados con el grado de manifestación de estrés, tanto académico como en la realiza- ción de sus prácticas, lo que configuró un estudio de campo, no experimental, de nivel descriptivo, con muestra intencional de treinta estudiantes cursantes del 10mo semestre, empleado como instrumento de levantamiento de información el cuestio- nario. Entre los resultados, los factores relacionados con mayor nivel de estrés académico, en la dimensión situaciones gene- radoras: sobrecarga de tareas, entendimiento de los temas de clase y tiempo limitado para hacer los trabajos; en la dimensión reacciones físicas: trastornos del sueño, somnolencia y morder- se las uñas; y, en la dimensión reacciones psicológicas: inquie- tud, ansiedad y problemas de concentración; de los factores relacionados con nivel de estrés en prácticas profesionales, de la dimensión realización: no saber como responder al paciente, desmejora y denuncia del paciente; y, de la dimensión clima organizacional: carga laboral excesiva. Se concluye que los fac- tores relacionados con el nivel de estrés tienen énfasis en la for- mación académica y no poseen un nivel alto de impacto, plan- teándose acciones orientadoras para ser gestionados; además, la existencia de estrés académico es determinante estadística- mente de la existencia de estrés durante prácticas profesionales.This article is aimed at proposing actions that contribute to re- ducing academic stress and during professional practices, pres- ent in students of the last semester of the Nursing program of the UDES, based on knowing, from the quantitative paradigm, the perception of the students on the factors related to the degree of manifestation of stress, both academic and in the re- alization of their practices, which configured a field study, non- experimental, of descriptive level, with an intentional sample of thirty students attending the 10th semester, employing as an in- strument for gathering information, the questionnaire. Among the results, the factors related to a higher level of academic stress, in the dimension of the generating situation: task over- load, understanding of class topics, and limited time to do as- signments; in the physical reactions dimension: sleep disorders, drowsiness, and nail-biting; and, in the psychological reactions dimension: restlessness, anxiety and concentration problems; of the factors related to the level of stress in professional practices, of the achievement dimension: not knowing how to respond to the patient, deterioration, and complaint of the patient; and the organizational climate dimension: excessive workload. It is concluded that the factors related to the level of stress, have an emphasis on academic training and do not have a high level of impact, proposing guiding actions to be managed. Further- more, the existence of academic stress is a statistically deter- minant of the existence of stress during professional practices

Maximal respiratory pressure reference equations in healthy adults and cut-off points for defining respiratory muscle weakness

[Abstract] Introduction: Maximal inspiratory and expiratory pressures (PImax/PEmax) reference equations obtained in healthy people are needed to correctly interpret respiratory muscle strength. Currently, no clear cut-off points defining respiratory muscle weakness are available. We aimed to establish sex-specific reference equations for PImax/PEmax in a large sample of healthy adults and to objectively determine cut-off points for respiratory muscle weakness. Methods: A multicentre cross-sectional study was conducted across 14 Spanish centres. Healthy non-smoking volunteers aged 18-80 years stratified by sex and age were recruited. PImax/PEmax were assessed using uniform methodology according to international standards. Multiple linear regressions were used to obtain reference equations. Cut-off points for respiratory muscle weakness were established by using T-scores. Results: The final sample consisted of 610 subjects (314 females; 48 [standard deviation, SD: 17] years). Reference equations for PImax/PEmax included body mass index and a squared term of the age as independent variables for both sexes (p<0.01). Cut-off points for respiratory muscle weakness based on T-scores ≥2.5 SD below the peak mean value achieved at a young age were: 62 and 83cmH2O for PImax and 81 and 109cmH2O for PEmax in females and males, respectively. Conclusion: These reference values, based on the largest dataset collected in a European population to date using uniform methodology, help identify cut-off points for respiratory muscle weakness in females and males. These data will help to better identify the presence of respiratory muscle weakness and to determine indications for interventions to improve respiratory muscle function

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p &lt; 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics