Variaciones de la comunidad edáfica dentro de suelos cultivados y de estepa en la Patagonia Norte

Los microartrópodos de la mesofauna edáfica (MME), integran procesos ecosistémicos que determinan propiedades y funcionamiento del suelo. El valle inferior del río Negro, Argentina, comprende una estepa arbustivo-graminosa, con 24.000ha irrigadas. Como práctica de conservación se realiza una rotación de cultivos de cebolla 6 meses y alfalfa 5 años. Los objetivos del trabajo fueron: evaluar variaciones en la abundancia de los MME bajo un ciclo de rotación y las variaciones de las propiedades físicas y químicas (FQ) del suelo. Se planteó como hipótesis que los cultivos afectan negativamente la abundancia de microartrópodos y el ciclo de rotación disminuye estos efectos. Los tratamientos evaluados fueron: T1: cebolla; T2 alfalfa con 5 meses de implantada; T3 alfalfa con 5 años de implantada y T4 estepa. Se trabajó sobre 9 muestras (3 por réplica), para análisis biológicos, físicos y químicos, por tratamiento. Las variables FQ medidas fueron: densidad aparente (DA), porcentaje de humedad (%H), conductividad eléctrica (CE), pH en pasta de suelo (pH) y porcentaje de materia orgánica total (MO). Los MME extraídos con embudos de Berlese, fueron contados y separados en categorías taxonómicas superiores. Se ordenaron las réplicas con un análisis de componentes principales (PCA) y las diferencias entre tratamientos se analizaron con Modelos Lineales Generalizados Mixtos (MLGM). E PCA agrupó las réplicas de T4 por mayores valores de CE y menores de %H, DA y pH. El resto de los tratamientos mostró tendencias opuestas. El MLGM de las variables FQ, genero agrupamientos similares al PCA, respecto a CE y %H. El MLGM de abundancia de individuos (m2 a 0,07 m de profundidad), mostró diferencias significativas para Astigmata y Colémbolos. El ciclo de rotación permitiría el establecimiento de una comunidad edáfica con mayores abundancias que la estepa, los tratamientos se diferenciaron significativamente por los taxa de Colémbolos y Astigmata.Facultad de Ciencias Naturales y Muse

Deserción estudiantil en el pregrado de la Facultad de Odontología de la Universidad de Antioquia 2004-2014

ABSTRACT: Academic dropout is described as the permanent abandonment of classrooms and the lack of continuity in education. The overall goal of the present study was to identify the main causes leading to academic dropout among students enrolled in the Universidad de Antioquia School of Dentistry between 2004 and 2014. Methods: a descriptive and retrospective study including quantitative and qualitative techniques based on an individual survey to 16 dropouts and 18 reentry students, who voluntarily responded their respective surveys; descriptive statistics was conducted using version 23 of the IBM-SPSS software, and qualitative methods were used to analyze the categories found in the informal questions. Results: dropout was due in 37.5% of cases to academic difficulties, 31.3% to academic program change, 18.8% to economic or work-related reasons, 6.2% to relocation to another city, and 6.2% of participants did not respond. The reasons why reentry students fail courses include academic difficulties (38.9%), work-related reasons (27.8%), and physical or mental health, such as lack of self-esteem (33.3%). The students’ opinion on the education received while enrolled in the School of Dentistry was excellent by 50%, good by 43.8% and poor by 6.3%. Conclusions: academic dropout in higher education is a complex, personal, family, institutional, and social phenomenon. But the most important thing for the School of Dentistry and Universidad de Antioquia as a whole is to think of diverse strategies to ensure student retention.RESUMEN: La deserción estudiantil se entiende como el abandono definitivo de las aulas de clase y la falta de continuidad en la formación académica. El objetivo general del presente estudio consistió en identificar las principales causas de la deserción académica de los estudiantes que ingresaron a la Facultad de Odontología de la Universidad de Antioquia entre 2004 y 2014. Métodos: estudio descriptivo y retrospectivo con técnicas cuantitativas y cualitativas basado en una encuesta individual a 16 estudiantes de deserción y a 18 estudiantes de reingreso, quienes voluntariamente respondieron sus respectivas encuestas; para ello se utilizó estadística descriptiva con el programa IBM-SPSS versión 23, y por métodos cualitativos se analizaron las categorías encontradas en las preguntas no estructuradas. Resultados: la cancelación del semestre de los desertores obedeció en el 37,5% de los casos a las dificultades académicas, el 31,3% se dio por cambio de programa, el 18,8% por razones económicas o motivos laborales, el 6,2% por traslado a otra ciudad y el 6,2% no respondieron. Las razones por las cuales los estudiantes de reingreso perdieron los cursos son: el 38,9% por dificultades académicas, el 27,8% por motivos laborales y el 33,3% por razones de salud física o mental (falta de autoestima). La opinión sobre la formación recibida durante su permanencia en la facultad fue excelente para el 50%, buena para el 43,8% y regular para el 6,3%. Conclusiones: la deserción estudiantil en la educación superior es un fenómeno complejo, personal, familiar, institucional y social. Pero lo más importante para la Facultad de Odontología y para la Universidad de Antioquia en general es pensar diversas estrategias que les garanticen a los estudiantes la permanencia en la universidad

BIRC6 Is Associated with Vulnerability of Carotid Atherosclerotic Plaque

Carotid atherosclerotic plaque rupture can lead to cerebrovascular accident (CVA). By comparing RNA-Seq data from vascular smooth muscle cells (VSMC) extracted from carotid atheroma surgically excised from a group of asymptomatic and symptomatic subjects, we identified more than 700 genomic variants associated with symptomatology (p < 0.05). From these, twelve single nucleotide polymorphisms (SNPs) were selected for further validation. Comparing genotypes of a hospital-based cohort of asymptomatic with symptomatic patients, an exonic SNP in the BIRC6 (BRUCE/Apollon) gene, rs35286811, emerged as significantly associated with CVA symptomatology (p = 0.002; OR = 2.24). Moreover, BIRC6 mRNA levels were significantly higher in symptomatic than asymptomatic subjects upon measurement by qPCR in excised carotid atherosclerotic tissue (p < 0.0001), and significantly higher in carriers of the rs35286811 risk allele (p < 0.0001). rs35286811 is a proxy of a GWAS SNP reported to be associated with red cell distribution width (RDW); RDW was increased in symptomatic patients (p < 0.03), but was not influenced by the rs35286811 genotype in our cohort. BIRC6 is a negative regulator of both apoptosis and autophagy. This work introduces BIRC6 as a novel genetic risk factor for stroke, and identifies autophagy as a genetically regulated mechanism of carotid plaque vulnerability.This work was financially supported by grants from the Departments of Education (Ref. PIBA2018-67) and Health (Ref. RIS3-2019222038) of the Basque Government, Vitoria-Gasteiz, Spain; by the Spanish Neurovascular Network (INVICTUSplus) (Ref. RD16/0019/0007) funded by the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Madrid, Spain; and by the research project grant (IKERIKTUS) funded by the RefbioII Trans-Pyrenean Cooperation Network for Biomedical Research financed by Horizon 2020. I.A. is supported by the Maratón EiTB 2017 for Funding of Research into Stroke, Bilbao, Spain (Ref. BIO18/IC/005); R.T.N. is the recipient of a fellowship from the Secretaría Nacional de Ciencia y Tecnología e Innovación (SENACYT; Convocatoria Doctorado de Investigación Ronda III, 2018; Ref. BIDP-III-2018-12) of the Gobierno Nacional, República de Panamá

Causal factors of student desertion from the school of dentistry of the University of Antioquia from 1997 to 2004

ABSTRACT: Student desertion is the definitive abandonment of the classroom by different reasons and the non continuance of the academic program. There are different determining factors. These could be intrinsic, that is, belonging to the student, or extrinsic when they don’t depend on the student. Methods: this is retrospective, descriptive educational study with a qualitative - quantitative analysis that allows the determination of causal factors of student desertion in the School of Dentistry of the University of Antioquia. Of the 71 deserting in the period 1997-1 through 2004-1, only 50 answered the survey, 16 who reentered the program and 34 that deserted these were the two groups analyzed. A different survey was presented to each group in order to find the intrinsic and extrinsic factors, the social-cultural and demographic variables that might have influenced the desertion. The results of this survey were complemented for analyses with focus groups. Results: student desertion in the school is a phenomenon that has been slowly increasing during the past 10 years, with the highest peak in year 2001 (18.1% deserters, and 35.7% for reentering students). The highest desertion appeared in the fourth semester, (29.4% for deserters, and 31.3% for reentering students), this can be attributed according to the analysis with focal groups, to the initiation of clinical practice, where they confront their fears and have greater management and responsibility problems with patients. Conclusions: among the extrinsic factors in desertion in order according to relevance are: financial factors, work, academic load, poor methodology and sexual harassment. Among the intrinsic factors is noticeable the change of academic programs due to lack of motivation, and lack of time. It is suggested that Institutions of Higher Education offer a more flexible curricula specially in the scheduling in order to decrease student desertion.RESUMEN: La deserción estudiantil es el abandono definitivo de las aulas de clase por diferentes razones y la no continuidad en el programa académico. Existen diferentes factores que la determinan, tanto intrínsecos propios del estudiante como extrínsecos cuando estos no dependen del estudiante. Métodos: investigación educacional descriptiva retrospectiva, con análisis cualicuantitativo para determinar los factores causales de la deserción estudiantil en la Facultad de Odontología de la Universidad de Antioquia. De los 71 estudiantes desertores en el período comprendido entre 1997-1 y 2004-1, sólo 50 respondieron a la encuesta, 16 de reingreso y 34 desertores, los cuales se consideraron los dos grupos de estudio. Se realizó una encuesta diferente para cada grupo, para conocer los factores intrínsecos y extrínsecos, variables socioculturales y demográficas que pudieron influir en la deserción. Los resultados de estas encuestas se profundizaron para su análisis con grupos focales. Resultados: la deserción estudiantil en la Facultad es un fenómeno que paulatinamente ha aumentado en los últimos diez años, con el pico más alto en 2001 (18,1% para los desertores y 35,7% para reingreso). La mayor deserción se presentó en el cuarto semestre (29,4% para desertores y 31,3% para reingreso), puede atribuirse según el análisis llevado a cabo en el grupo focal, al inicio de la Clínica, donde confrontan sus temores y sienten mayores problemas de manejo y de responsabilidad frente al paciente. Conclusiones: entre de los factores extrínsecos de la deserción, en orden según su relevancia aparece el factor económico, por motivos laborales, carga académica, mala metodología y por acoso sexual. Entre los intrínsecos se destaca el cambio de programa por falta de motivación al no llenar sus expectativas y por falta de tiempo. Se sugiere que las instituciones de educación superior ofrezcan mayor flexibilidad curricular especialmente en sus horarios para disminuir la deserción estudiantil

Resistance of Leishmania (Viannia) Panamensis to Meglumine Antimoniate or Miltefosine Modulates Neutrophil Effector Functions

Leishmania (Viannia) panamensis (L. (V.) p.) is the main causative agent of cutaneous leishmaniasis in Colombia and is usually treated with either meglumine antimoniate (MA) or miltefosine (MIL). In recent years, there has been increasing evidence of the emergence of drug-resistance against these compounds. Neutrophils are known to play an important role in immunity against Leishmania. These cells are rapidly recruited upon infection and are also present in chronic lesions. However, their involvement in the outcome of infection with drug-resistant Leishmania has not been examined. In this study, human and murine neutrophils were infected in vitro with MA or MIL drug-resistant L. (V.) p. lines derived from a parental L. (V.) p. drug-susceptible strain. Neutrophil effector functions were assessed analyzing the production of reactive oxygen species (ROS), the formation of neutrophil extracellular trap (NET) and the expression of cell surface activation markers. Parasite killing by neutrophils was assessed using L. (V.) p. transfected with a luciferase reporter. We show here that MA and MIL-resistant L. (V.) p. lines elicited significantly increased NET formation and MA-resistant L. (V.) p. induced significantly increased ROS production in both murine and human neutrophils, compared to infections with the parental MIL and MA susceptible strain. Furthermore, neutrophils exposed to drug-resistant lines showed increased activation, as revealed by decreased expression of CD62L and increased expression of CD66b in human neutrophils yet presented higher survival within neutrophils than the drug-susceptible strain. These results provide evidence that parasite drug-susceptibility may influences neutrophil activation and function as well as parasite survival within neutrophils. Further investigaton of the inter-relationship of drug susceptibility and neutrophil effector function should contribute to better understanding of the factors involved in susceptibility to anti-Leishmania drugs

Low aerobic capacity in McArdle disease: A role for mitochondrial network impairment?

[Background]: McArdle disease is caused by myophosphorylase deficiency and results in complete inability for muscle glycogen breakdown. A hallmark of this condition is muscle oxidation impairment (e.g., low peak oxygen uptake (VO2peak)), a phenomenon traditionally attributed to reduced glycolytic flux and Krebs cycle anaplerosis. Here we hypothesized an additional role for muscle mitochondrial network alterations associated with massive intracellular glycogen accumulation. [Methods]: We analyzed in depth mitochondrial characteristics-content, biogenesis, ultrastructure-and network integrity in skeletal-muscle from McArdle/control mice and two patients. We also determined VO2peak in patients (both sexes, N = 145) and healthy controls (N = 133). [Results]: Besides corroborating very poor VO2peak values in patients and impairment in muscle glycolytic flux, we found that, in McArdle muscle: (a) damaged fibers are likely those with a higher mitochondrial and glycogen content, which show major disruption of the three main cytoskeleton components-actin microfilaments, microtubules and intermediate filaments-thereby contributing to mitochondrial network disruption in skeletal muscle fibers; (b) there was an altered subcellular localization of mitochondrial fission/fusion proteins and of the sarcoplasmic reticulum protein calsequestrin-with subsequent alteration in mitochondrial dynamics/function; impairment in mitochondrial content/biogenesis; and (c) several OXPHOS-related complex proteins/activities were also affected. [Conclusions]: In McArdle disease, severe muscle oxidative capacity impairment could also be explained by a disruption of the mitochondrial network, at least in those fibers with a higher capacity for glycogen accumulation. Our findings might pave the way for future research addressing the potential involvement of mitochondrial network alterations in the pathophysiology of other glycogenoses.The present study was funded by grants received from the Fondo de Investigaciones Sanitarias (FIS, PI17/02052, PI18/00139, PI19/01313, and PI20/00645) and cofunded by ‘Fondos FEDER’. Gisela Nogales-Gadea and Carmen Fiuza-Luces are supported by the Miguel Servet research contracts (ISCIII CD14/00032 and CP18/00034, respectively and cofounded by Fondos FEDER′). Research by Pedro L. Valenzuela is funded by a postdoctoral contract granted by Instituto de Salud Carlos III (Sara Borrell, CD21/00138). Monica Villarreal Salazar is supported by the Mexican National Council for Science and Technology (CONACYT)

Recent advances in the application of stable isotopes as nutritional tools in aquaculture

From an ecological point of view, aquaculture systems consist of simple food webs having a limited number of nutritional sources. These characteristics facilitate the application of stable isotope ratios of carbon and nitrogen (δ13C and δ15N) to assess the flow of dietary components. Due to rapid and measurable bioaccumulation of the heavier stable isotopes, such isotopic shifts can be tracked at different times and at each trophic step to provide an indicator of what dietary components are being incorporated into animal tissue and how fast. The present manuscript presents results from recent, controlled nutritional experiments designed to quantify the relative contribution of dietary carbon and nitrogen supplied by different dietary items. Stable isotopes ratios were measured in a range of food sources and experimental animals. In a first experiment, juvenile shrimp Litopenaeus vannamei were reared on co-feeding regimes having different proportions of live biomass of the green macroalgae Ulva clathrata and inert feed in order to identify nutritional contributions to tissue growth using dual stable isotope analysis. In another trial, nitrogen stable isotopes were measured to explore the relative dietary nitrogen contributions from fish meal and pea meal (Pisum sativum) to the growth of white shrimp postlarvae fed low protein diets having different proportions of both ingredients. In a third, multidisciplinary experiment, Senegalese sole (Solea senegalensis) larvae were used as a model to evaluate the effect of different larval feeding regimes on (1) trypsinogen gene expression (ssetryp1), (2) trypsin and chymotrypsin activities and (3) changes in stable isotope composition to estimate the assimilation of dietary carbon from the larval diets

Anemia hemolítica autoinmune postinfección por virus de la hepatitis A. Informe de caso

La anemia hemol&iacute;tica autoinmune se asocia con una variedad de virus hepatotr&oacute;picos, en particular citomegalovirus (CMV), virus del Epstein-Barr y de la hepatitis B. No es frecuente dentro de la historia natural de la hepatitis A, la aparici&oacute;n de anemia hemol&iacute;tica, y cuando se presenta, generalmente se asocia a deficiencia de glucosa-6-fosfato deshidrogenasa. Presentamos el caso de un paciente de sexo masculino sin hem&oacute;lisis previa, con astenia e ictericia de dos meses de evoluci&oacute;n y hepatomegalia 14 cm por debajo del reborde costal derecho. Los hallazgos en los ex&aacute;menes de laboratorios mostraron anemia hemol&iacute;tica con Coombs directo positivo, anticuerpos tipo inmunoglobulina M contra el virus de la hepatitis A positivos, niveles de bilirrubinas 20 veces y aminotrasferasas cuatro veces por arriba del rango normal; con estos datos el paciente fue diagnosticado como hepatitis A complicada con anemia hemol&iacute;tica y probable hepatitis autoinmune asociada, por lo que se inici&oacute; manejo con corticoides, alcanz&aacute;ndose mejor&iacute;a cl&iacute;nica. Resaltamos la importancia de descartar la infecci&oacute;n por el virus de la hepatitis A como posible etiolog&iacute;a de anemia hemol&iacute;tica autoinmune. &nbsp

ECONOMIC EVALUATION OF RECOVERING NATURAL PROTECTION WITH CONCURRENT RELOCATION OF THE POPULATION THREATENED BY TSUMANI HAZARDS IN CENTRAL COASTAL ECUADOR

Tsunamis are destructive forces which threaten life, social infrastructure and production, resulting in enormous economic losses. In the last two decades destructive tsunamis as those in Indonesia (2004), Japan (2011) and Chile (2010 and 2015), caused more than 366,353 deaths and economic losses over 355 billions US$. Our present study focuses on a theoretical case of economic and human losses that tsunami impact can have in Muisne, along the central Ecuadorian coast. Using a cost benefit analysis (BCA) framework, we estimate the cost of recovery of a mangrove ecosystem in Muisne, where earthquakes with magnitudes up to 8.8 Mw can generate tsunamis with run-ups up to 43 meters. Economic benefits of environmental goods and services from Muisne mangroves are estimated to reach 16.7 US$ million/year. To maintain local wellbeing and businesses in the region, it is estimated that the mangrove recovery costs may reach up to 7.3 million US$. In terms of preventing loss human loss of life and maintaining human wellbeing, we calculate the value of community relocation to be approximately 93.2 million US$. Therefore, the total economic benefits from a recovering the Muisne ecosystem would be around 109.9 million US$ and the benefit/cost ratio is B⁄C=1.16, meaning that the recovery of the Muisne mangroves has a higher value than resettlement costs, and that makes good public policy sense

Autoimmune haemolytic anaemia associated to hepatitis A. Case report

La anemia hemolÍtica autoinmune se asocia con una variedad de virus hepatotrópicos, en particular citomegalovirus (CMV), virus del Epstein-Barr y de la hepatitis B. No es frecuente dentro de la historia natural de la hepatitis A, la aparición de anemia hemolÍtica, y cuando se presenta, generalmente se asocia a deficiencia de glucosa-6-fosfato deshidrogenasa. Presentamos el caso de un paciente de sexo masculino sin hemólisis previa, con astenia e ictericia de dos meses de evolución y hepatomegalia 14 cm por debajo del reborde costal derecho. Los hallazgos en los exámenes de laboratorios mostraron anemia hemolÍtica con Coombs directo positivo, anticuerpos tipo inmunoglobulina M contra el virus de la hepatitis A positivos, niveles de bilirrubinas 20 veces y aminotrasferasas cuatro veces por arriba del rango normal; con estos datos el paciente fue diagnosticado como hepatitis A complicada con anemia hemolÍtica y probable hepatitis autoinmune asociada, por lo que se inició manejo con corticoides, alcanzándose mejorÍa clÍnica. Resaltamos la importancia de descartar la infección por el virus de la hepatitis A como posible etiologÍa de anemia hemolÍtica autoinmune.Autoimmune hemolytic anemia is associated with a variety of hepatotropic viruses, in particular cytomegalovirus (CMV), Epstein-Barr virus and hepatitis B. It is not frequent within the natural history of hepatitis A, the appearance of hemolytic anemia, and when it occurs, it is generally associated with glucose-6-phosphate dehydrogenase deficiency. We present the case of a male patient without previous hemolysis, with asthenia and jaundice for two months and hepatomegaly 14 cm below the right costal margin. Laboratory examination findings showed direct positive Coombs hemolytic anemia, positive immunoglobulin M antibodies against hepatitis A virus, bilirubin levels 20 times and aminotrases four times above the normal range; With these data, the patient was diagnosed as complicated hepatitis A with hemolytic anemia and probable associated autoimmune hepatitis, for which management with corticosteroids was initiated, achieving clinical improvement. We highlight the importance of ruling out hepatitis A virus infection as a possible etiology of autoimmune hemolytic anemia