126 research outputs found

    Anfibios y reptiles de la región centro-sur del departamento de Caldas, Colombia

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    Based on specimens housed in a scientific collection, besides literature and field observations, we present an updated list of the herpetofauna of the south-central region of Caldas, Colombia. The composition of anurans, lizards and snakes was compared with other Colombian assemblages. In addition, all species were categorized according to the extent of its distribution range. A total of 36 amphibians (35 anurans and one salamander) and 38 reptiles (15 lizards, 22 snakes and one turtle) are currently known for the south-central region of Caldas. Comparisons of the amphibians and reptiles assemblages showed low and moderate values (Coefficient of biogeographic resemblance, range = 0,018–0,440; X̅ = 0,152), indicating that about frogs, lizards, snakes, and overall herpetofauna, the south-central region of Caldas is more akin to the Yotoco Forestal Reserve (0.326, 0.421, 0.585, 0.440, respectively). Regarding geographical distribution patterns, six species (8.1%) are endemic to the Northern region of the Cordillera Central, 40 species (54%) correspond to elements of an Andean-tropical fauna, 14 species (18.9%) are distributed from Central America to the Andes, and eight species (10.8%) have a wide distribution throughout the continent.Se presenta un listado actualizado sobre la herpetofauna de la región comprendida entre el centro y el sur del departamento de Caldas, con base en especímenes de colección, literatura especializada y observaciones en campo. La composición de anuros, lagartos y serpientes, se analiza y compara con otras regiones de Colombia. Todas las especies registradas fueron categorizadas según el patrón de su distribución geogrí¡fica en función de su amplitud. Un total de 36 anfibios (35 anuros y una salamandra) y 38 reptiles (15 lagartos, 22 serpientes y una tortuga), son conocidos actualmente para la región centro-sur de Caldas. Las comparaciones de los ensamblajes de anfibios y reptiles conjuntamente mostraron valores bajos y moderados (coeficiente de semejanza biogeográfica, intervalo = 0,018–0,440; X̅ = 0,152), indicando que en cuanto a anuros (0,326), lagartos (0,421), serpientes (0,585), y la herpetofauna en general (0,440), la región analizada es más afín al bosque de la Reserva Forestal Yotoco. Seis especies (8,1%) son endémicas del norte de la Cordillera Central, 40 especies (54%) corresponden a elementos propios de la fauna andina-tropical, 14 especies (18,9%) están distribuidas desde Centroamérica hasta los Andes, y ocho especies (10,8%) presentan una amplia distribución en todo el continente

    Clasificación automática de las vocales en el lenguaje de señas colombiano

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    Sign language recognition is a highly-complex problem due to the amount of static and dynamic gestures needed to represent such language, especially when it changes from country to country. This article focuses on static recognition of vowels in Colombian Sign Language. A total of 151 images were acquired for each class, and an additional non-vowel class with different scenes was also considered. The object of interest was cut out of the rest of the scene in the captured image by using color information. Subsequently, features were extracted to describe the gesture that corresponds to a vowel or to the class that does not match any vowel. Next, four sets of features were selected. The first one contained all of them; from it, three new sets were generated. The second one was extracted from a subset of features given by the Principal Component Analysis (PCA) algorithm. The third set was obtained by Sequential Feature Selection (SFS) with the FISHER measure. The last set was completed with SFS based on the performance of the K-Nearest Neighbor (KNN) algorithm. Finally, multiple classifiers were tested on each set by cross-validation. Most of the classifiers achieved a performance over 90%, which led to conclude that the proposed method allows an appropriate class distinction.El reconocimiento del lenguaje de señas es un problema de alta complejidad, debido a la cantidad de gestos estáticos y dinámicos necesarios para representar dicho lenguaje, teniendo en cuenta que el mismo variará para cada país en particular. Este artículo se enfoca en el reconocimiento de las vocales del lenguaje colombiano de señas, de forma estática. Se adquirieron 151 imágenes por cada clase, teniendo en cuenta también una clase no vocal adicional con diferentes escenas. A partir de cada imagen capturada se separa el objeto de interés del resto de la escena usando información de color; luego, se extraen características para describir el gesto correspondiente a cada vocal o a la clase que no corresponde a ninguna vocal. Posteriormente, se seleccionan cuatro conjuntos de características. El primero con la totalidad de ellas; a partir de este salen tres nuevos conjuntos: el segundo extrayendo un subconjunto de características mediante el algoritmo de Análisis de Componentes Principales (PCA). El tercer conjunto, aplicando Selección Secuencial hacia Adelante (SFS), mediante la medida de FISHER y el último conjunto con SFS basado en el desempeño del clasificador de los vecinos más cercanos (KNN). Finalmente se prueban múltiples clasificadores para cada conjunto por medio de validación cruzada, obteniendo un desempeño superior al 90% para la mayoría de los clasificadores, concluyendo que la metodología propuesta permite una adecuada separación de las clases

    Reliability and validity of an FFQ for South American children and adolescents from the SAYCARE study

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    Objective:The purpose of this study was to analyse the reliability and validity of a semi-quantitative FFQ to assess food group consumption in South American children and adolescents.Design:The SAYCARE (South American Youth/Child cARdiovascular and Environmental) study is an observational, multicentre, feasibility study performed in a sample of 3-to 18-year-old children and adolescents attending private and public schools from six South American countries. Participants answered the FFQ twice with a two-week interval and three 24-h dietary recalls. Intraclass and Spearman''s correlations, weighted Cohen''s kappa (¿w), percentage of agreement and energy-adjusted Pearson''s correlation coefficients were calculated.Setting:Seven cities in South America (Buenos Aires, Lima, Medelin, Montevideo, Santiago, Sao Paulo and Teresina).Subjects:A sample of 200 children and 244 adolescents for reliability analyses and 252 children and 244 adolescents for validity analyses were included.Results:Depending on the food group, for children and adolescents, reliability analyses resulted in Spearman''s coefficients from 0·47 to 0·73, intraclass correlation coefficients from 0·66 to 0·99, ¿w coefficients from 0·35 to 0·63, and percentage of agreement between 72·75 and 83·52 %. In the same way, validity analyses resulted in Spearman''s coefficients from 0·17 to 0·37, energy-adjusted Pearson''s coefficients from 0·17 to 0·61, ¿w coefficients from 0·09 to 0·24, and percentages of agreement between 45·79 and 67·06 %.Conclusion:The SAYCARE FFQ achieved reasonable reliability and slight-moderate validity for almost all food groups intakes. Accordingly, it can be used for the purpose of ranking the intake of individuals within a population

    Mitochondrial echoes of first settlement and genetic continuity in El Salvador

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    Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

    Remission of obesity and insulin resistance is not sufficient to restore mitochondrial homeostasis in visceral adipose tissue

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    Metabolic plasticity is the ability of a biological system to adapt its metabolic phenotype to different environmental stressors. We used a whole-body and tissue-specific phenotypic, functional, proteomic, metabolomic and transcriptomic approach to systematically assess metabolic plasticity in diet-induced obese mice after a combined nutritional and exercise intervention. Although most obesity and overnutrition-related pathological features were successfully reverted, we observed a high degree of metabolic dysfunction in visceral white adipose tissue, characterized by abnormal mitochondrial morphology and functionality. Despite two sequential therapeutic interventions and an apparent global healthy phenotype, obesity triggered a cascade of events in visceral adipose tissue progressing from mitochondrial metabolic and proteostatic alterations to widespread cellular stress, which compromises its biosynthetic and recycling capacity. In humans, weight loss after bariatric surgery showed a transcriptional signature in visceral adipose tissue similar to our mouse model of obesity reversion. Overall, our data indicate that obesity prompts a lasting metabolic fingerprint that leads to a progressive breakdown of metabolic plasticity in visceral adipose tissue

    Type 2 Diabetes Variants Disrupt Function of SLC16A11 through Two Distinct Mechanisms

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    Type 2 diabetes (T2D) affects Latinos at twice the rate seen in populations of European descent. We recently identified a risk haplotype spanning SLC16A11 that explains ∼20% of the increased T2D prevalence in Mexico. Here, through genetic fine-mapping, we define a set of tightly linked variants likely to contain the causal allele(s). We show that variants on the T2D-associated haplotype have two distinct effects: (1) decreasing SLC16A11 expression in liver and (2) disrupting a key interaction with basigin, thereby reducing cell-surface localization. Both independent mechanisms reduce SLC16A11 function and suggest SLC16A11 is the causal gene at this locus. To gain insight into how SLC16A11 disruption impacts T2D risk, we demonstrate that SLC16A11 is a proton-coupled monocarboxylate transporter and that genetic perturbation of SLC16A11 induces changes in fatty acid and lipid metabolism that are associated with increased T2D risk. Our findings suggest that increasing SLC16A11 function could be therapeutically beneficial for T2D. Video Abstract [Figure presented] Keywords: type 2 diabetes (T2D); genetics; disease mechanism; SLC16A11; MCT11; solute carrier (SLC); monocarboxylates; fatty acid metabolism; lipid metabolism; precision medicin
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