26 research outputs found

    Evidence on Night Movements of Macroinvertebrates to Macrophytes in a Pampean Stream

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    Abstract Nocturnal invertebrate abundance peaks in lotic systems are usually associated to drift, however, diel migrations other than drift may be important in slow-flowing systems. Then, macroinvertebrate distribution on macrophytes may change along the day as result of vertical or horizontal migration from sediments or the water column. My objective was to determine whether macroinvertebrate abundance on macrophytes changes along 24 h. Three Ceratophyllum demersum patches were sampled in late spring from the Las Flores stream (Central Argentina) at 11:20 h, 17:10 h, 23:00 h and 5:00 h. Macroinvertebrates were counted and identified, and relative abundances were estimated for each sampling time. The dominant groups of macroinvertebrates sampled were Oligochaeta, Amphipoda and Cladocera. The relative abundance of macroinvertebrates on macrophytes was the highest at 5:00 h, when dissolved oxygen in water reached its minimum. In conclusion, the abundance of macroinvertebrates on macrophytes in Pampean streams may increase at night, probably as result of nocturnal migration driven by changes in predation risk or dissolved oxygen

    Manual do anticoagulado

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    Elaboración de manual técnico de operación y mantenimiento de miniplanta piloto de flotación móvil para la empresa SGS Minerals

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    281 p.El proceso productivo del cobre integra diversas tareas que deben ser realizadas para conseguir el producto final. Estas tareas nos entregan muchos desafíos para quienes deben ejecutar las mismas, así con la finalidad de obtener el mineral en su máxima pureza, altamente rentable y con las mayores medidas de seguridad existentes. Es por esto, que antes de realizar cualquier proceso a gran escala, se deben realizar estudios de laboratorio y pruebas piloto. Las cuales nos permiten cuantificar el funcionamiento, optimizando sus parámetros de ejecución. En busca de entregar las mejores soluciones ingenieriles para la industria minera, SGS Minerals ha desarrollado una Miniplanta piloto de flotación móvil, la cual permite transportar un laboratorio a la zona de trabajo y realizar simulaciones a escala del proceso de flotación que se ejecuta a nivel industrial. Por esta razón, durante el desarrollo y diseño de la Miniplanta fue necesario normalizar y estandarizar los procesos, equipos y arquitectura de funcionamiento. Así, el objetivo de esta memoria es realizar un manual técnico de operación y mantenimiento para asegurar el correcto uso de la Miniplanta y optimizar su vida útil, considerando también todas las medidas de seguridad pertinentes para el caso. Este proyecto busca ser la base de trabajo para las futuras modificaciones o necesidades que pueda tener la Miniplanta piloto, asegurando el óptimo funcionamiento y conseguir un proceso de flotación a escala totalmente disponible para su interpretación a nivel industrial

    Developmental genoarchitectonics as a key tool to interpret the mature anatomy of the chondrichthyan hypothalamus according to the prosomeric model

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    The hypothalamus is a key vertebrate brain region involved in survival and physiological functions. Understanding hypothalamic organization and evolution is important to deciphering many aspects of vertebrate biology. Recent comparative studies based on gene expression patterns have proposed the existence of hypothalamic histogenetic domains (paraventricular, TPa/PPa; subparaventricular, TSPa/PSPa; tuberal, Tu/RTu; perimamillary, PM/PRM; and mamillary, MM/RM), revealing conserved evolutionary trends. To shed light on the functional relevance of these histogenetic domains, this work aims to interpret the location of developed cell groups according to the prosomeric model in the hypothalamus of the catshark Scyliorhinus canicula, a representative of Chondrichthyans (the sister group of Osteichthyes, at the base of the gnathostome lineage). To this end, we review in detail the expression patterns of ScOtp, ScDlx2, and ScPitx2, as well as Pax6-immunoreactivity in embryos at stage 32, when the morphology of the adult catshark hypothalamus is already organized. We also propose homologies with mammals when possible. This study provides a comprehensive tool to better understand previous and novel data on hypothalamic development and evolutionThis work was supported by Ministerio de Economía, Industria y Competitividad – Agencia Estatal de Investigación (grant No. BFU2017-89861-P) partially financed by the European Social Fund, and by Xunta de Galicia (grant No. ED431C 2021/18)S

    Aplicaciones médico-quirúrgicas de la anatomía ósea del seno frontal en relación al trauma cráneo facial

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    Los senos frontales son dos cavidades en forma de pirámide triangular, de vértice superior y base inferior, a cada lado de la línea media y excavados en el espesor de este hueso. La anatomía y morfología de los senos frontales se utiliza desde hace años en la medicina forense para la identificación de cadáveres dada su gran versatilidad. En lo que respecta a la cirugía maxilofacial es de suma importancia la presencia de megasenos frontales en el diagnóstico y tratamiento de fracturas hundimiento por ruptura de la tabla externa ante trauma de dicha región, observándose la presencia de las mismas ante patrones de senos anormalmente desarrollados.Facultad de Ciencias Médica

    Prosomeric organization of the hypothalamus in an elasmobranch, the catshark Scyliorhinus canicula

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    The hypothalamus has been a central topic in neuroanatomy because of its important physiological functions, but its mature organization remains elusive. Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain. Here we studied the molecular organization of the hypothalamus and neighboring telencephalic domains in a cartilaginous fish, the catshark, Scyliorhinus canicula, focusing on ScFoxg1a, ScShh, ScNkx2.1, ScDlx2/5, ScOtp, and ScTbr1 expression profiles and on the identification αacetylated-tubulin-immunoreactive (ir), TH-ir, 5-HT-ir, and GFAP-ir structures by means of immunohistochemistry. Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates. These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates.This work was supported by grants from the Spanish Dirección General de Investigación-FEDER (BFU2010- 15816), the Xunta de Galicia (10PXIB200051PR, CN 2012/237), European Community-Research Infrastructure Action under the FP7 “Capacities” Specific Programme (ASSEMBLE 227799), the Région Centre, Région Bretagne (EVOVERT grant number 049755; PEPTISAN project), National Research Agency (grant ANR-09-BLAN-026201), CNRS, Université d’Orléans and Université Pierre et Marie Curie. GNSD would like to thank Spanish SEPE for its funding supportS

    Incidence, clinical characteristics and management of inflammatory bowel disease in Spain: large-scale epidemiological study

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    (1) Aims: To assess the incidence of inflammatory bowel disease (IBD) in Spain, to describe the main epidemiological and clinical characteristics at diagnosis and the evolution of the disease, and to explore the use of drug treatments. (2) Methods: Prospective, population-based nationwide registry. Adult patients diagnosed with IBD—Crohn’s disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)—during 2017 in Spain were included and were followed-up for 1 year. (3) Results: We identified 3611 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 million inhabitants. The overall incidence (cases/100, 000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U; 53% of patients were male and median age was 43 years (interquartile range = 31–56 years). During a median 12-month follow-up, 34% of patients were treated with systemic steroids, 25% with immunomodulators, 15% with biologics and 5.6% underwent surgery. The percentage of patients under these treatments was significantly higher in CD than UC and IBD-U. Use of systemic steroids and biologics was significantly higher in hospitals with high resources. In total, 28% of patients were hospitalized (35% CD and 22% UC patients, p < 0.01). (4) Conclusion: The incidence of IBD in Spain is rather high and similar to that reported in Northern Europe. IBD patients require substantial therapeutic resources, which are greater in CD and in hospitals with high resources, and much higher than previously reported. One third of patients are hospitalized in the first year after diagnosis and a relevant proportion undergo surgery. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain : Large-Scale Epidemiological Study

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    (1) Aims: To assess the incidence of inflammatory bowel disease (IBD) in Spain, to describe the main epidemiological and clinical characteristics at diagnosis and the evolution of the disease, and to explore the use of drug treatments. (2) Methods: Prospective, population-based nationwide registry. Adult patients diagnosed with IBD-Crohn's disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)-during 2017 in Spain were included and were followed-up for 1 year. (3) Results: We identified 3611 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 million inhabitants. The overall incidence (cases/100,000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U; 53% of patients were male and median age was 43 years (interquartile range = 31-56 years). During a median 12-month follow-up, 34% of patients were treated with systemic steroids, 25% with immunomodulators, 15% with biologics and 5.6% underwent surgery. The percentage of patients under these treatments was significantly higher in CD than UC and IBD-U. Use of systemic steroids and biologics was significantly higher in hospitals with high resources. In total, 28% of patients were hospitalized (35% CD and 22% UC patients, p < 0.01). (4) Conclusion: The incidence of IBD in Spain is rather high and similar to that reported in Northern Europe. IBD patients require substantial therapeutic resources, which are greater in CD and in hospitals with high resources, and much higher than previously reported. One third of patients are hospitalized in the first year after diagnosis and a relevant proportion undergo surgery

    Correction : Chaparro et al. Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain: Large-Scale Epidemiological Study. J. Clin. Med. 2021, 10, 2885

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    The authors wish to make the following corrections to this paper [...]

    Influence of macrophyte patch environmental heterogeneity on associated organisms in a Pampean stream

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    En los arroyos pampeanos, las abundantes y diversas plantas acuáticas constituyen la principal fuente de heterogeneidad ambiental. La hipótesis de trabajo fue que la heterogeneidad de diferentes especies de macrófitas, cuantificada por la dimensión fractal (DF), tiene un efecto positivo sobre la abundancia y diversidad de macroinvertebrados que viven sobre ellas, debido a la influencia positiva de la complejidad sobre el espacio habitable por organismos pequeños y la heterogeneidad del hábitat. Se realizaron tres muestreos estacionales de seis parches mixtos con distintas macrófitas sumergidas (Ceratophyllum demersum, Egeria densa, Elodea ernstae, Stuckenia striata) en un tramo del arroyo Las Flores (NE de pcia. Buenos Aires). En cada ocasión, se estimaron las DF de las macrófitas, la biomasa de algas epífitas, así como la abundancia, biomasa, diversidad y tamaño de los invertebrados asociados. La DF de las macrófitas se encontró relacionada positivamente con la densidad de macroinvertebrados pero no con su biomasa, riqueza o diversidad. La relación entre la DF y la abundancia relativa de invertebrados por clase de tamaño, fue positiva para los organismos pequeños y negativa para los organismos grandes. Se realizaron varios experimentos de campo y laboratorio con E. densa, E. ernstae y análogos plásticos, encontrándose una correlación significativa y positiva entre la DF y la densidad de macroinvertebrados, independientemente del tamaño de los organismos. En los arroyos pampeanos, la complejidad de la arquitectura de las macrófitas afecta positivamente a la abundancia de invertebrados pero no a su biomasa ni diversidad.Dense and diverse communities of macrophytes are the main source of environmental heterogeneity in Pampean streams. The hypothesis was that heterogeneity caused by different macrophyte species, measured as fractal dimension (FD), has a positive effect on associated macroinvertebrate density and diversity due to a positive effect of complexity on available space for small organisms and habitat heterogeneity. Field work consisted in three sampling dates when six macrophyte patches with several submerged species (Ceratophyllum demersum, Egeria densa, Elodea ernstae, Stuckenia striata) were sampled in a reach of Las Flores stream (NE of Buenos Aires province). Macrophyte FD, epiphytic algae biomass, and macroinvertebrate density, biomasss, richness, diversity and size were estimated each time. Macrophyte FD was positively associated to macroinvertebrate density but not to macroinvertebrate biomass, richness or diversity. FD and macroinvertebrate relative abundance were positively related for small organisms and negatively related for big invertebrates. Several field and laboratory experiments were conducted with E. densa, E. ernstae and plastic analogs. Macroinvertebrate density was positively affected by FD but no effect of invertebrate size on this relationship was detected. According to this, in Pampean streams macrophyte architecture complexity has a positive effect on associated macroinvertebrate abundance but not on its biomass or diversity.Fil:Ferreiro, Nicolás Andrés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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