4,924 research outputs found
Effects of environmental perturbations during postnatal development on the phenotypic integration of the skull
Integration and modularity are fundamental determinants of how natural selection effects evolutionary change in complex multivariate traits. Interest in the study of the specific developmental basis of integration through experimental approaches is fairly recent and it has mainly focused on its genetic determinants. In this study, we present evidence that postnatal environmental perturbations can modify the covariance structure by influencing the variance of some developmental processes relative to the variances of other processes that contribute to such structure. We analyzed the effects of the reduction of nutrient supply in different ontogenetic stages (i.e. before and after weaning, and from birth to adulthood) in Rattus norvegicus. Our results show that this environmental perturbation alters the phenotypic variation/covariation structure of the principal modules of the skull (base, vault, and face). The covariance matrices of different treatment groups exhibit low correlations and are significantly different, indicating that the treatments influence covariance structure. Postnatal nutrient restriction also increases the variance of somatic growth. This increased variance drives an increase in overall integration of cranial morphology through the correlated allometric effects of size variation. The extent of this increase in integration depends on the time and duration of the nutritional restriction. These results support the conclusion that environmental perturbations can influence integration and thus covariance structure via developmental plasticity.Fil: Gonzalez, Paula Natalia. University of Calgary; CanadáFil: Oyhenart, Evelia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Hallgrimsson, Benedikt. University of Calgary; Canad
Prenatal development of skull and brain in a mouse model of growth restriction
Patterns of covariation result from the over-lapping effect of several developmental processes. By perturbing certain specific developmental processes, ex-perimental studies contribute to a better understanding of their particular effects on the generation of phenotype. The aim of this work was to analyze the interactions among morphological traits of the skull and the brain during late prenatal life (18.5 days postconception) in mice exposed to maternal protein undernutrition. Images from the skull and brain were obtained through micro-computed tomography and 3D landmark coordinates were digitized in order to quantify shape and size of both structures with geometric morphometric techniques. The results highlight a systemic effect of protein restriction on the size of the skull and the brain, which were both significantly reduced in the under-nourished group compared to control group. Skull shape is partially explained by brain size, and patterns of shape variation were only partially coincident with previous re-ports for other ontogenetic stages, suggesting that allomet-ric trajectories across pre- and postnatal ages change their directions. Within the skull, neurocranial and facial shape traits covaried strongly, while subtle covariation was found between the shape of the skull and the brain. These find-ings are in line with former studies in mutant mice and reveal the importance of carrying out analyses of pheno-typic variation in a broad range of developmental stages. The present study contributes to the basic understanding of epigenetic relations among growing tissues and has di-rect implications for the field of paleoanthropology, where inferences about brain morphology are usually derived from skull remains.Los patrones de covariación entre rasgos fenotí-picos resultan de la acción de diversos procesos que se sola-pan durante el desarrollo. Los estudios experimentales cons-tituyen la aproximación más adecuada para evaluar el efecto de procesos específicos en la generación de tales patrones. El objetivo de este trabajo es analizar las interacciones entre rasgos morfológicos craneofaciales y cerebrales durante la vida prenatal tardía (18,5 días posconcepción) en ratones ex-puestos a desnutrición proteica materna. Se obtuvieron imá-genes del cráneo y cerebro a partir de microtomografía com-putada y se digitalizaron landmarks en 3D para cuantificar la forma y tamaño con técnicas de morfometría geométrica. Los resultados subrayan un efecto sistémico de la restricción proteica en el tamaño del cráneo y el cerebro. La forma del cráneo es parcialmente explicable por el tamaño cerebral y los patrones de variación en forma fueron sólo en parte coin-cidentes con los reportados antes para otras edades, lo cual sugiere que las trayectorias alométricas a lo largo de la vida pre- y posnatal cambian su dirección. Los rasgos de forma del neurocráneo y el esqueleto facial covariaron fuertemen-te, aunque se encontró una asociación débil entre la forma del cráneo y del cerebro. Estos resultados concuerdan con estudios previos en ratones mutantes y revelan la relevancia de analizar la variación fenotípica en distintas etapas. El pre-sente estudio contribuye al conocimiento básico de las inte-racciones epigenéticas entre tejidos en crecimiento y tiene implicancias en el campo paleoantropológico en el que las inferencias acerca de la morfología cerebral son usualmen-te derivadas del análisis del cráneo.Fil: Barbeito Andrés, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Gonzalez, Paula Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Hallgrimsson, Benedikt. University of Calgary; Canad
Una cartografía de las desigualdades y los conflictos desde los sistema mundo
Los mapas siempre nos ayudan a tener una visión, si no exacta, por lo menos general, de los fenómenos; el libro reseñado es eso, un mapa particular de las crisis globales vistas desde la investigación para la paz y la teoría de los sistema mundo, como acercamientos teórico-metodológicos a las desigualdades, los con ictos y las violencias que se producen en estas nuevas relaciones NorteSur. Sin embargo, es una cartografía que analiza las crisis de los países centrales, que los hacen transitar a las fronteras de lo periférico y sus consecuencias para los países considerados periféricos
¿Es posible explorar nuevas alternativas para la formación de creencias en la decisión de invertir en capital humano?
Es imposible negar el sentimiento de fastidio por parte de uno que otro economista frente a la teoría clásica. Fastidio que nace cuando insistentemente se compara el supuesto de racionalidadperfecta y la manera como el ser humano en realidad se comporta. Pero, no sólo ha sido la insatisfacción de muchos economistas frente a dicha construcción teórica, sino tambiénlos intentos por reemplazar el modelo básico del hombre racional,los que han hecho que surjan una serie de propuestas para modelar el problema de la toma de decisiones de una manera diferente. Así como muchos han expresado su disconformidad,este artículo tendrá como propósito hacer lo mismo. Es decir, intentará explorar una nueva alternativa para entender cómo y por qué los agentes toman la decisión de invertir en capital humano.Procesamiento de información, formación de creencias, vista y oido como canales de transmisión
Building Engagement Through Developing Students’ Sense of Self-Control
Students who enter public schools in the United States in the latter part of their academic career may lack the English language proficiency or capital necessary to successfully participate in mainstream content courses. Students such as these, known as late arrivals, face even greater difficulties when they enter academic institutions that or not equipped to provide language supports that ensure students can access content. Arriving at a later age and grade level, places additional pressure on educators and students to enter mainstream language classrooms. With little control or access to be active participants in the new academic settings, these students often disengage from academic activities and the academic community as a whole. Students lack the knowledge of how their cultural wealth can be converted into academic capital, leading to low engagement and achievement. This project intends to address the problem of academic engagement of emergent bilingual students in secondary schools by providing teachers with curriculum that can be used to teach emergent bilingual students how their existing knowledge of language can be leveraged to access content in a new language. Therefore, this project intends to develop students sense of self-control through empowering them with tools to participate in the learning process even when English language support is limited.
The project takes the form of lessons to be delivered as a unit of instruction for students who are transitioning from sheltered English Language Development (ELD) classes into more mainstream classes. These lessons include detailed activities for teachers to help students identify the type of knowledge and cultural wealth they already possess and explicit ways students can use it to acquire content in mainstream language classes. The activities within the lessons also give students the opportunity to develop discussion norms and to practice producing written work similar to those expected in a mainstream content course. Through empowering students with tools to participate in the academic setting, this project will develop students’ sense of self-control because they become more invested in their academic coursework when they recognize that they can impact the outcome of their academic achievement
The role of parents in their children’s emotion regulation in Colombia
openEmotion regulation is a fundamental process influencing how individuals navigate their emotional well-being and interpersonal interactions. This study delves into the role of parents in shaping children's emotion regulation, exploring the relationship between children's and parents' emotion regulation strategies, family support perceptions, and cultural influences. Employing a well-established online survey encompassing diverse cultural contexts, the study uncovers a positive relationship between children's and parents' emotion regulation strategies, emphasizing the pivotal role of parental involvement. Additionally, it identifies a strong correlation between children's and parents' perceptions of maternal support, underlining the significance of familial support dynamics. Cultural analysis reveals distinct trust-related factors but no significant impact on emotion regulation strategies for both children and parents. This research underscores the importance of parental awareness and engagement in supporting their children's emotional development, offering valuable insights for parenting education and family therapy.Emotion regulation is a fundamental process influencing how individuals navigate their emotional well-being and interpersonal interactions. This study delves into the role of parents in shaping children's emotion regulation, exploring the relationship between children's and parents' emotion regulation strategies, family support perceptions, and cultural influences. Employing a well-established online survey encompassing diverse cultural contexts, the study uncovers a positive relationship between children's and parents' emotion regulation strategies, emphasizing the pivotal role of parental involvement. Additionally, it identifies a strong correlation between children's and parents' perceptions of maternal support, underlining the significance of familial support dynamics. Cultural analysis reveals distinct trust-related factors but no significant impact on emotion regulation strategies for both children and parents. This research underscores the importance of parental awareness and engagement in supporting their children's emotional development, offering valuable insights for parenting education and family therapy
Structure, kinetic characterization and subcellular localization of the two ribulose 5-phosphate epimerase isoenzymes from Trypanosoma cruzi
The enzyme of the pentose phosphate pathway (PPP) ribulose-5-phosphate-epimerase (RPE) is encoded by two genes present in the genome of Trypanosoma cruzi CL Brener clone: TcRPE1 and TcRPE2. Despite high sequence similarity at the amino acid residue level, the recombinant isoenzymes show a strikingly different kinetics. Whereas TcRPE2 follows a typical michaelian behavior, TcRPE1 shows a complex kinetic pattern, displaying a biphasic curve, suggesting the coexistence of -at least-two kinetically different molecular forms. Regarding the subcellular localization in epimastigotes, whereas TcRPE1 is a cytosolic enzyme, TcRPE2 is localized in glycosomes. To our knowledge, TcRPE2 is the first PPP isoenzyme that is exclusively localized in glycosomes. Over-expression of TcRPE1, but not of TcRPE2, significantly reduces the parasite doubling time in vitro, as compared with wild type epimastigotes. Both TcRPEs represent single domain proteins exhibiting the classical α/β TIM-barrel fold, as expected for enzymes with this activity. With regard to the architecture of the active site, all the important amino acid residues for catalysis -with the exception of M58- are also present in both TcRPEs models. The superimposition of the binding pocket of both isoenzyme models shows that they adopt essentially identical positions in the active site with a residue specific RMSD < 2Å, with the sole exception of S12, which displays a large deviation (residue specific RMSD: 11.07 A). Studies on the quaternary arrangement of these isoenzymes reveal that both are present in a mixture of various oligomeric species made up of an even number of molecules, probably pointing to the dimer as their minimal functional unit. This multiplicity of oligomeric species has not been reported for any of the other RPEs studied so far and it might bear implications for the regulation of TcRPEs activity, although further investigation will be necessary to unravel the physiological significance of these structural findings.Fil: Gonzalez, Soledad Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Valsecchi, Wanda Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Maugeri, Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Delfino, Jose Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Cazzulo, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin
Inestabilidad del desarrollo en estructuras craneo-faciales de poblaciones humanas sudamericanas
Diversos factores genéticos y ambientales pueden actuar sobre los mecanismos que amortiguan el efecto de perturbaciones aleatorias durante el desarrollo, resultando en un aumento de la inestabilidad del desarrollo (ID) y de la variación a nivel individual. El objetivo de este trabajo es analizar el grado y el patrón de asimetría fluctuante (AF) en el cráneo, como una medida de ID, en poblaciones con distinto tipo de subsistencia. Asimismo, se evalúa la existencia de diferencias entre la base, la bóveda y el esqueleto facial. Se relevaron landmarks tridimensionales sagitales y bilaterales en 109 cráneos de Chubut, San Juan y SO de Pampa. El método de Superposición Procrustes Generalizado fue usado para extraer los componentes simétrico y asimétrico de la forma. Los análisis preliminares indicaron que el error de medición y la asimetría direccional dan cuenta de un porcentaje reducido de la variación total, mientras que la AF explica entre el 10 y el 15% de la misma. La magnitud de AF –estimada como la distancia Procrustes entre las configuraciones originales y sus imágenes reflejadas– de la bóveda y la región facial resultó mayor en San Juan, mientras que la base no presentó diferencias entre las muestras. Los patrones de forma del componente asimétrico indican que la muestra de Chubut se diferencia en la base y la cara, mientras que la de San Juan se diferencia en la bóveda. En resumen, los resultados obtenidos sugieren variación modular en la ID del cráneo y diferencias entre las muestras analizadas.Regulatory mechanisms acting on the effect of stochastic perturbations during development can be modulated by diverse environmental and genetic factors, resulting in increased developmental instability (DI) and individual variation. It has been suggested that subsistence-related ecological changes could have significantly influenced craniofacial morphology of South American aboriginal populations. In this paper, the magnitude and pattern of fluctuating asymmetry, used as a DI measure, are compared among the samples with different subsistence strategies and among 3 craniofacial modules. Midline and bilateral 3D landmarks were recorded in 109 skulls from Chubut, San Juan and SW of the Pampean region. The Generalized Procrustes Superimposition method was used to extract the symmetric and asymmetric components of shape. Preliminary analyses show that measurement error and directional asymmetry account for a reduced amount of total variation, while FA explains 10 to 15% of it. FA magnitude –estimated as the Procrustes distances between the original configurations and their reflections– found in the vault and facial region was higher for San Juan sample, while the cranial base did not show any differences among samples. Shape patterns in the asymmetric component show that Chubut sample is different from the others as regards cranial base and facial configurations, while San Juan is different in relation to vault. Results suggest modular variation in skull DI and differences among the analyzed samples.Fil: Lotto, Federico Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Gonzalez, Paula Natalia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin
Novel missense variant in SPTBN2 possibly associated with spinocerebellar ataxia type 5 presenting as Parkinson´s disease
Spinocerebellar ataxias are a heterogeneous group of neurodegenerative diseases. There are more than 40 subtypes described so far, being spinocerebellar ataxia type 5 (SCA5) a rare autosomal-dominant ataxia with pure cerebellum involvement. The gene responsible is the non-erythrocyte beta 2 spectrin gene (SPTBN2), encoding β-III spectrin, highly expressed in Purkinje cells. Onset is usually before 30 years, although it ranges from infancy to 70 years. The main clinical manifestations are limb and gait ataxia (> 90%); however, some patients also show trunk ataxia, sensory deficits, abnormal eye movements, dysarthria, and hyperactive deep tendon reflexes (25–90%)
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