A small animal pet prototype with sub-millimetre spatial resolution based on tRPCs

The aim of this thesis is to explore the possibility of building a Positron Emission Tomography (PET) system with sub-millimetre spatial resolution and absence of parallax error based on timing Resistive Plate Chambers (tRPC), to be used in the imaging of small animals. An RPC-PET prototype has been built consisting in two detector heads. Each head is built from sixteen independent metal-glass RPCs with a gas gap of 0.300 mm working on avalanche mode in the standard mixture. The characteristics that could turn a RPC-PET into a competitive system can be summarized as follows: • Sub-millimetre spatial resolution uniform on the entire Field of View (FOV) (parallax free error). Approximately 0.500 mm Full Width at Half Maximun (FWHM), experimentally measured with a point-like 22Na source for a system diameter of 60 mm. • Simulated, absolute central point source sensitivity of 2.1 % and Noise Equivalent Count (NEC) peak of 320 kcps. • Low cost, less than 100 k€, due to the inexpensiveness of the materials used in its constructions (except the FEE and DAQ), allowing the fast spread of the system for many research groups

Effects of litter mixing on litter decomposition and soilproperties along simulated invasion gradients of non-nativetrees

Aims Plant invasions generally lead to mixtures betweennative and non-native litter. We assess the interactionsbetween leaf litters from two invasive non-native trees(Robinia pseudoacia or Ailanthus altissima) and the nativePopulus alba on litter decomposition, nutrient releaseand soil properties along two gradients of invasion.Methods Microcosms with field-collected soil coveredby varying proportions of native and non-native littersimulated the two invasion gradients. We assessed theproportion of remaining litter mass and nutrient mass(N, P, C), and soil C, N-NO3−, total N, and pH, fivetimes throughout a period of 11 months. Observedvalues were compared to the expected values on theassumption of no interactions.Results Litter mass and C mass decayed slower inRobinia and faster in Ailanthus than in Populus. Thethree species immobilized N and P. Soil properties didnot differ across pure litters. Both litter mixture gradientsshowed additive or antagonistic interactions onlitter decomposition, whereas N and P mass were equalor higher than expected. The proportion of non-nativelitter in the mixture had non-linear effects on mostvariables, suggesting that the impact of these nonnativetrees on litter decay levels off or even declinesas they become more abundant.Conclusion The impacts of Ailanthus and Robinia litteron soil processes should not be derived from singlespecies experiments, both due to non-additive effectsand to non-linear responses to litter abundance.Ministerio de Ciencia, Innovación y UniversidadesComunidad de Madri

School and Family Environment is Positively Associated with Extracurricular Physical Activity Practice among 8 to 16 Years Old School Boys and Girls

Extracurricular physical activity in children and adolescents can help achieve compliance with the World Health Organization (WHO) recommendations for physical activity. The purpose of this study was to evaluate factors in school and family environments of children and adolescents in Spain that could be related to the practice of extracurricular physical activity. Multistage random cluster sampling was conducted to include 128 schools with the participation of 10,096 students between the ages of 7 and 16. Participants completed the survey of sports habits designed by the National Sports Council. The results revealed a higher participation in extracurricular sports activities among boys (OR: 1.67 (1.5–1.9)) and students in primary education (up to 12 years old) (OR: 1.8 (1.7–2.0)). Likewise, a statistically significant relationship (p < 0.005) was observed between families where another family member practiced sports and lower number of screen time hours, improved academic performance, and better self-perceived health. Participation of children and adolescents in extracurricular sports activities seems to be associated with their immediate environment. It is therefore essential to emphasize the importance of establishing physical activity habits from an early age in family and school environments

Análisis evolutivo del concepto de familia: un estudio de cara con la jurisprudencia constitucional colombiana

This study is developed based on a compilation of jurisprudence issued by the Constitutional Court, taking into account the need to indicate the evolution and conceptualization that the concept of family has had in the legal system, taking as a basis what is contemplated in article 42 of the National Political Charter, and through said analysis it is concluded that the Institution of the family, fills many of the gaps to which socially and on a daily basis it is tried to respond, by virtue of the fact that it is the beginning and the end both in an individual and in the social dynamics in generally.El presente estudio se desarrolla con base a un compilado de jurisprudencias emitidas por las Corte Constitucional atendiendo a la necesidad de indicar la evolución y conceptualización que ha tenido el concepto de familia en el ordenamiento jurídico, tomando como base lo contemplado en el artículo 42 de la Carta Política nacional, y a través de dicho análisis se colige que la Institución de la familia, suple muchos de los vacíos a los que socialmente y a diario se intenta dar respuesta, en virtud de que aquella es principio y fin tanto en un individuo como en la dinámica social en general

Caracterización de síntomas del secamiento foliar progresivo, una nueva enfermedad de la palma de aceite, en el departamento del Magdalena

Secamiento foliar progresivo or SFP is a disease Recorded in the late 90s in oil palm plantations in some municipalities of the department of Magdalena. This problem causes a gradual deterioration of plants, and general symptoms caused can be confused with those induced by other sanitary problems. In three crops, the symptoms of disease were characterized with objective to differentiate SFP of other diseases, and so, we can get necessary information for taking the best decision about management of the SFP. Internals and externals symptoms were characterized; were determined evolution of leaves symptoms per days and percentage of roots affected. Externals symptoms were evident only on leaves and they occurred gradually and descendant direction; they were observed initially on leaves levels second, showed yellow zones in any part of foliage similar to a band, but with initiation on apical leaf; after, leaves showed increase of size of yellow bands, and reddish shade and necrotic tissues. A severity scale was adjusted for evaluating external symptoms on leaves, with five levels. The development of foliar symptoms required a greater number of days in the upper levels that the lower levels leaves. In the same order, a greater number of days were necessary for the symptoms evolved from grade 1 to 2 than grade 2 to 3 and 3 to 4, respectively. As the leaves mature, the foliar symptoms are more severe, allowing infer that the problem is progressive and is the result accumulated permanent damage in roots of the plants. In plants with foliar symptoms grade 2, the percentage of damaged roots was 58% on average; those roots showed rotten and rusty zones and roots splited in two or more sitesSecamiento foliar progresivo o SFP, es una enfermedad registrada a finales de los 90 en plantaciones de palma de aceite en municipios del departamento del Magdalena, la cual causa deterioro gradual de las plantas y presenta síntomas que pueden confundirse con los de otros problemas fitosanitarios. Se caracterizó el cuadro sintomatológico del SFP para diferenciar este disturbio de los demás registrados en palma de aceite y, con ello, contribuir a mejorar la toma de decisiones sobre su manejo. En tres plantaciones se caracterizaron síntomas externos e internos, y se determinó la evolución de síntomas foliares por días y el porcentaje de raíces afectadas. Los síntomas externos fueron evidentes en hojas, ocurriendo de manera gradual y en forma descendente, observándose inicialmente en el segundo nivel de hojas; incluye zonas amarillas en forma de bandas en cualquier parte del foliolo, comenzando en el ápice de la hoja. Posteriormente, aumentan las zonas amarillas con cambios a tonalidades rojizas y necrosis de los tejidos. Se ajustó la escala de evaluación con cinco grados de intensidad de la expresión de los síntomas en foliolos. Se de requirió un mayor número de días en los niveles superiores de la planta que en los niveles inferiores, con el fin de que los síntomas evolucionaran de un grado de severidad a otro; un mayor número de días fue necesario para pasar de grado 2 a grado 3, que de grado 3 a 4. A medida que las hojas maduran los síntomas se expresan con mayor severidad, permitiendo inferir que el problema es progresivo y que es el resultado del daño permanente y acumulado que sufre la planta en sus raíces. En palmas con síntoma foliar en grado 2, el porcentaje de raíces dañadas es de 58 % en promedio, expresado en pudriciones, oxidaciones y bifurcacione

Searching for predictors of the variability of impacts caused by non-native trees on regulating ecosystem services worldwide

Humans have introduced non-native trees (NNT) all over the world to take advantage of the plethora of benefits they provide. However, depending on the context, NNT may present a diverse range of effects on ecosystem services (ES), from benefits to drawbacks, which may hinder the development of policies for these species. Unfortunately, the attempts so far to understand the impacts of NNT on ES only explained a low proportion of their variation. Here we analyze the variation in impacts of NNT on regulating ecosystem services (RES) by using a global database, which covers the effect size of multiple NNT species on six RES (climate regulation, soil erosion regulation, soil fertility, soil formation, hydrological cycle regulation, and fire protection). We used a wide range of predictors to account for the context-dependency of impacts distributed in five groups: the RES type, functional traits of both the NNT and the dominant NT of the recipient ecosystem, phylogenetic and functional distances between NNT and NT, climatic context, and human population characteristics. Using boosted regression trees and regression trees, we found that the most influential predictors of NNT impacts on RES were annual mean temperatures and precipitation seasonality, followed by the type of RES, human population density, and NNT height. In regions with warm temperatures and low seasonality, NNT tended to increase RES. NNT impacts were greater in densely populated regions. Smaller NNT exerted greater positive impacts on climate regulation and soil erosion regulation in tropical regions than in other climates. We highlight that benign climates and high population density exacerbate the effects of NNT on RES, and that soil fertility is the most consistently affected RES. Knowledge of the factors that modulate NNT impacts can help to predict their potential effects on RES in different parts of the world and at various environmental setting

Comparative study of the combustion, pyrolysis and gasification processes of Leucaena leucocephala: Kinetics and gases obtained

Leucaena leucocephala is a fast-growing leguminous biomass with great energetical and valueadded chemical compounds potential (saccharides, biogas, bio-oil, etc.). Using the thermogravimetric and derivative thermogravimetric curves, the different trends followed by L. leucocephala during pyrolysis, 0.25 equivalence ratio (ER) of gasification, 0.50 equivalence ratio of gasification and combustion were analyzed, and the activation energies were obtained by Distributed Activation Energy Model (DAEM) method. Gas samples were collected through adsorption tubes during the gasification at 0.25 ER and 0.50 ER to observe the distribution of the main chemical products in this process by gas chromatography/mass spectrometry and were compared with pyrolysis products. It was found that small amounts of oxygen have changes in the kinetics of the process, leading to significant decreases in the activation energy at the beginning of the degradation of components such as cellulose (from 170 to 135 kJ mol-1 at 0.25 conversion at 0.50 ER gasification). The activation energy of lignin disintegration was also reduced (342 kJ mol-1), assimilating the beginnings of gasification processes such as the Boudouard reaction. 0.50 ER gasification is potentially an interesting process to obtain quality bio-oil, since a large amount of hexane is detected (44.96%), and value-added oxygenated intermediates such as alcohols and glycols. Gasification at 0.25 ER, on the other hand, is much more similar to pyrolysis, obtaining a wide variety of short-chain compounds resulting from the disintegration of the main lignocellulosic components, especially ketones such as 1-hydroxypropan-2-one (19.48%), and notable amount of furans and anhydrosugars like d-allose (5.50%).This study was supported by the Ministry of Economy and Competitiveness (Spain), as well as by the National Research Program Oriented to the Challenges of Society (Project PID2020-112875RB-C21 funded by MCIN/AEI 10.13039/501100011033, t)he Ministry of Innovation, Science and Business of the Government of the Junta of Andalusia (Spain), the Operative Program is framed within FEDER Andalusia 2014–2020 with Project number UHU-125540, and the CEPSA Foundation Chair. Funding for open access charge: Universidad de Huelva / CBUA

Factores de gestión que permiten una eficiente administración financiera en las universidades privadas, perspectiva teórica

En el presente trabajo se analizan desde una perspectiva teórica los factores de gestión que permiten una eficiente administración financiera en las universidades privadas. El artículo establece el sustento teórico en donde varios autores publican información que fundamenta cada una de las variables tanto dependiente como independientes, por lo que se detallan las definiciones de cada uno de los constructos, las relaciones entre los mismos y el porqué de esas relaciones. Se concluye con la propuesta de un modelo teórico que fundamenta y la hipótesis propuesta.&nbsp

Adaptação transcultural de uma escala sobre conhecimentos e atitudes de métodos contraceptivos em adolescentes, do contexto cultural peruano ao colombiano

Currently sexual and reproductive education continues to be a taboo in some families, consequently, the responsibility of comprehensive sexuality education has been transmitted to schools. This education includes the family planning component, which must be approached in a timely manner, considering that in Colombia, the beginning of sexual activity occurs between approximately 14 and 15 years of age. An objective measurement of deficiencies in terms of sexual and reproductive education in adolescents can be obtained through scales with adequate psychometric characteristics. Therefore, the objective of this research article was to culturally adapt a validated Peruvian scale of knowledge and attitudes about contraceptive methods in adolescents. The methodology to carry out the adaptation process began with the authorization for the use of the scale by its authors, later a first focus group was carried out, the suggested modifications were notified, and when they were accepted a second focus group was carried out and the final version was built in Colombian Spanish. Ten high school students from two official schools in Bogotá were included; most of the suggested changes were due to unknown words, difficulties in understanding wording and interpretation problems. Finally, the modified scale can be considered for use in Colombia, considering that the cultural adaptation process was carried out in a school population. The importance of having the authorization of the authors of the scale and ideally adapting validated scales in populations with similar characteristics is emphasized. Actualmente la educación sexual y reproductiva continúa siendo un tabú para algunas familias, lo que ha relegado a los colegios la responsabilidad de la formación integral en sexualidad. Esta formación incluye el componente de planificación familiar, el cual debe ser abordado oportunamente, teniendo en cuenta que en Colombia el inicio de las relaciones sexuales ocurre entre los 14 y 15 años aproximadamente. Una medición objetiva sobre deficiencias en cuanto a educación sexual y reproductiva en los adolescentes es posible obtenerse por medio de escalas con adecuadas características psicométricas. Por lo tanto, el objetivo de este artículo de investigación fue adaptar culturalmente una escala peruana validada con conocimientos y actitudes sobre métodos anticonceptivos en adolescentes. La metodología para llevar a cabo el proceso de adaptación inició con la autorización para el uso de la escala por parte de sus autores, posteriormente se realizó un primer grupo focal, se notificaron las modificaciones sugeridas, y al ser aceptadas se llevó a cabo un segundo grupo focal y se construyó la versión final en español colombiano. Diez estudiantes de educación media de dos colegios oficiales de Bogotá fueron incluidos, la mayoría de los cambios sugeridos fueron debidos a palabras desconocidas, dificultades en la redacción y problemas de interpretación. Finalmente, la escala modificada puede considerarse para el uso en Colombia, teniendo en cuenta que se realizó el proceso de adaptación transcultural en una población escolar. Se recalca la importancia de contar con la autorización de los autores de la escala e idealmente adaptar escalas validadas en poblaciones con características similares. Atualmente, a educação sexual e reprodutiva continua sendo um tabu para algumas famílias, consequentemente, o que tornou às escolas a responsabilidade da formação integral em educação sexual integral.  Esta educação inclui o componente de planejamento familiar, que deve ser abordado oportunamente, levando em consideração que na Colômbia o início das relações sexuais ocorre aproximadamente entre os 14 e 15 anos de idade. Uma medida objetiva sobre as deficiências em termos de educação sexual e reprodutiva nos adolescentes pode ser obtida por meio de escalas com características psicométricas adequadas. Portanto, o objetivo deste artigo de pesquisa foi adaptar culturalmente uma escala peruana validada com conhecimentos e atitudes sobre métodos contraceptivos em adolescentes. A metodologia para a realização do processo de adaptação iniciou com a autorização para o uso da escala pelos seus autores, posteriormente foi realizado um primeiro grupo focal, notificaram-se as modificações sugeridas e, após aceitação, foi realizado um segundo grupo focal, construindo a versão final em espanhol colombiano. Foram incluídos dez alunos do ensino médio de duas escolas oficiais de Bogotá, a maioria das mudanças sugeridas foram devido a palavras desconhecidas, dificuldades na redação e problemas de interpretação. Finalmente, a escala modificada pode ser considerada para uso na Colômbia, levando em consideração que o processo de adaptação transcultural foi realizado em uma população escolar. Ressalta-se a importância de ter a autorização dos autores da escala e, idealmente, adaptar escalas validadas em populações com características semelhantes.

Diarrea por Campylobacter fetus jejuni y otros agentes infecciosos en niños del área rural de Puriscal, Costa Rica

artículo -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1984Between September 1979 and September 1981 a field study was conducted on the etiology of diarrhea' disease in the area of Puriscal, Costa Rica. The presence of enteric pathogens was investigated in the stools of 267 diarrheic children and 190 healthy controls. Both soups belong to yearly cohorts recruited at birth as part of a longitudinal multidisciplinary study of mothers and children. Campylobacter fetus lefuni was identified as the only pathogen in the stools of 24 diarrheic children (9%) and in four healthy controls (2% ), a significant difference (p< 0,05). The clinical features of the episodes were: irritability (77%), blood in stools (35%), anorexia (38,5%), and fever and vomiting (36%). Dehydration was not important among infected children (only one with 5% dehydration). All children received oral salt solutions and only two were treated with antibiotics. Rotaviruses were the main etiologic agents (17%) and Campylobacter ranked second (10,5% ). The frecuency of enterotoxigenic Enterobacteriaceae was similar in sick children and in controls (10%and 12%respectively).Entre setiembre de 1979 y setiembre de 1981, estudiamos 267 niños con diarrea aguda y 190 testigos, con el objeto de determinar la etiología y evaluar la importancia de Campylobacter fetus jejuni como agente etiológico y su influencia sobre el estado nutritional. Todos los niños tenían entre 0 y 24 meses de edad y pertenecen a las falanges anuales de un estudio longitudinal que realiza el INISA en el cantón de Puriscal, Costa Rica. Campylobacter fue el único agente en 24 niños con diarrea (9% ) y en cuatro niños sanos (2% ), encontrándose una diferencia significativa entre ambos grupos (x 2 = 9,05; p < 0,05). Además, se le encontró asociado a rotavirus o enterobacteriáceas toxigénicas en cuatro niños enfermos (1,5% ) y en dos testigos (1% ). El cuadro clínico se caracterizó por la evacuación de cinco a diez deposiciones líquidas al día, con sangre visible macroscópicamente en 39% de los casos. Los niños mostraron irritabilidad (77% ), anorexia (38,5% ), fiebre (36%) y vómitos (36%). Solo un niño presentó deshidratación del 5% y únicamente dos recibieron antibioticoterapia. El resto de los niños se recuperó satisfactoriamente mediante la administración de SUERORAL. El principal agente etiologico fue el rotavirus (17% ), seguido de Campylobacter (10,5%). La frecuencia de enterobacteriáceas toxigénicas fue similar en niños con diarrea y testigos (10% y 12% respectivamente).Universidad de Costa Rica, Instituto de investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA