422 research outputs found

    Synergistic effect of vascular endothelial growth factor gene inactivation in endothelial cells and skeletal myofibres on muscle enzyme activity, capillary supply and endurance exercise in mice

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    NEW FINDINGS: What is the central question of this study? Dose VEGF expressed by both endothelial cells and skeletal myofibers maintain the number of skeletal muscle capillaries and regulate endurance exercise. What is the main finding and its importance? VEGF expressed by both endothelial cells and skeletal myofibers is not essential for maintaining capillary number but does contribute to exercise performance. ABSTRACT: Many chronic diseases lead to exercise intolerance, with loss of skeletal muscle capillaries. While many muscle cell types (myofibers, satellite cells, endothelial cells, macrophages and fibroblasts) express VEGF, most muscle VEGF is stored in myofibers vesicles which can release VEGF to signal VEGF receptor-expressing cells. VEGF gene ablation in myofibers or endothelial cells alone does not cause capillary regression. We hypothesized that simultaneously deleting endothelial cell (EC) and skeletal myofiber (Skm) VEGF would cause capillary regression and impair exercise performance. This was tested in adult mice by simultaneous conditional deletion of the VEGF gene (Skm/EC-VEGF-/- mice) through the use of VEGFLoxP, HSA-Cre-ERT2 and PDGFb-iCre-ERT2 transgenes. These double-deletion mice were compared to three control groups - WT, EC VEGF deletion alone and myofiber VEGF deletion alone. Three weeks after initiating gene deletion, Skm/EC-VEGF-/- mice, but not SkmVEGF-/- or EC-VEGF-/- mice, reached exhaustion 40 minutes sooner than WT mice in treadmill tests (p = 0.002). WT, SkmVEGF-/-, and EC-VEGF-/-, but not Skm/EC-VEGF-/- mice, gained weight over the three weeks. Capillary density, fiber area and capillary:fiber ratio in soleus, plantaris, gastrocnemius and cardiac papillary muscle were similar across the groups. Phosphofructokinase and pyruvate dehydrogenase activities increased only in Skm/EC-VEGF-/- mice. These data suggest that deletion of VEGF signaling simultaneously in endothelial cells and myofibers, while reducing treadmill endurance and despite compensatory augmentation of glycolysis, is not required for muscle capillary maintenance. Reduced endurance remains unexplained, but may possibly be related to a role for VEGF in controlling perfusion of contracting muscle

    A corpus-based study of Spanish L2 mispronunciations by Japanese speakers

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    Abstract In a companion paper (Carranza et al.) submitted to this conference we discuss the importance of collecting specific L1-L2 speech corpora for the sake of developing effective Computer Assisted Pronunciation Training (CAPT) programs. In this paper we examine this point more deeply by reporting on a study that was aimed at compiling and analysing such a corpus to draw up an inventory of recurrent pronunciation errors to be addressed in a CAPT application that makes use of Automatic Speech Recognition (ASR). In particular we discuss some of the results obtained in the analyses of this corpus and some of the methodological issues we had to deal with. The corpus features 8.9 hours of spontaneous, semi-spontaneous and read speech recorded from 20 Japanese students of Spanish L2. The speech data was segmented and transcribed at the orthographic, canonical-phonemic and narrow-phonetic level using Praat software We report on the analyses of the combined annotations and draw up an inventory of errors that should be addressed in the training. We then consider how ASR can be employed to properly detect these errors. Furthermore, we suggest possible exercises that may be included in the training to improve the errors identified

    Utilización de inmunoreacciones para la detección de Scrapie en Óbex de ovinos provenientes de la XII Región de Chile

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    Scrapie is an neurodegenerative and infectious disease that affects sheep and goats. The purpose of this study is to compare both tecniques, ELISA and IHC, to determine the application factibility giving the conditions of the laboratory in the country. To develop this assay, fourty obex samples were taken from sheep of the XII Region of Chile and were processed for both techniques ELISA and IHC. The results showed 100% of the samples negative for Scrapie, using both diagnostic methods. Based in obtained and previously reported results, ELISA technique can be recommended to use in massive screening, since yields reliable and rapid test results and IHC is a confirmatory technique. Both techniques are necessary in the creation of current epidemiological surveillance programs in Chile. ELISA and IHC are easily performed given the current laboratories conditions of the Chilean country.    El Scrapie es una enfermedad infecciosa neurodegenerativa que afecta a ovinos y caprinos. Dada la importancia que tiene esta enfermedad es que se desarrolló este estudio enmarcado en la comparación de la técnica de ELISA y la de inmunohistoquímica en el diagnóstico de Scrapie, para determinar la factibilidad de aplicarlas en las condiciones de laboratorio país. Para ello se procesaron 40 muestras de óbex de ovinos en duplicado, provenientes de la XII Región de Chile, las cuales fueron sometidas paralelamente a la técnica de ELISA e IHQ. Como resultados se obtuvo un 100% de muestras negativas a Scrapie, sometidas a ambos métodos diagnósticos. Con los valores informados previamente y los obtenidos en esta investigación, es posible recomendar el ELISA como una técnica utilizable en muestreos masivos, ya que aporta resultados confiables de manera más rápida. La IHQ corresponde a una técnica confirmatoria y que ambas, son necesarias en la creación de programas de vigilancia epidemiológica activa en Chile, siendo factibles de realizar en las actuales condiciones de laboratorio país.  

    Prevalence and molecular identification of zoonotic Anisakis and Pseudoterranova species in fish destined to human consumption in Chile

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    Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94-1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23-0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097-0.309) in Chilean hakes, 15% (CI: 0.07-0.26) in snoeks, and 1.7% (CI: 0-0.089) in sea breams. Meanwhile, prevalence of anisakid larvae in internal organs showed highest values for peritoneum (100% and 83.3%) for snoeks and Chilean hakes, respectively, for liver (96.7%) and gonads (86.6%) in Chilean hakes, and for intestine (98.3%) in snoeks. Molecular analysis of collected anisakid L3 unveiled presence of two potentially zoonotic nematode species, i.e., Pseudoterranova cattani and Anisakis pegreffii. P. cattani was found in Chilean hakes and snoeks being the first molecular host species report for Chilean snoeks. Besides, A. pegreffii was also identified in these species being the first molecular report on this regard. These findings are relevant for better understanding of epidemiology of anisakiasis in Chilean coasts and for public health issues considering potential risk of human population due to its culinary preferences in eating raw fish

    Effect of the presence of inorganic ions and operational parameters on free cyanide degradation by ultraviolet C activation of persulfate in synthetic mining wastewater

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    This work studied the influence of several parameters on free cyanide (CN−) degradation (50 mg L−1) by the UVC-activated persulfate (PS) at alkaline conditions (UVC/PS). Firstly, photolysis and alkaline activation of PS were evaluated. Then, the effect of initial PS concentration (0.2, 0.4, and 0.6 g L−1) and dissolved oxygen in solution (absence/presence) were studied. Lastly, the influence of phosphate, carbonate, and nitrate presence at different concentrations (50, 150, 350, and 500 mg L−1) on CN− elimination was tested. Additionally, the electric energy per order (EEO), a measure of the energy consumption in the process was determined, and a mechanistic view of CN− degradation was proposed. The results show that photolysis and alkaline activation of PS degraded 8 and 11% of CN−, respectively, whereas their combination presented a synergistic effect on CN− pollutant elimination. While oxygen had a vital role in photolysis due to the formation of 1O2 to oxidize CN− to CNO−, HO• and SO4•− were primarily responsible for CN− degradation by UVC/PS. It was also found that cyanide removal followed a pseudo-first-order kinetics whose apparent reaction rate constant (k) increased from 0.0104 to 0.0297 min−1 as the initial concentration of PS increased from 0.2 to 0.6 g L−1, indicating a strong dependency of the removal efficiency on the PS amount. Remarkably, cyanide degradation by the combined UVC/PS showed a high CN− conversion and selectivity even in the presence of high concentrations of phosphate, carbonate, and nitrate ions (500 mg L−1), which resulted in CN− removals higher than 80% after 60 min of degradation treatment. Furthermore, the EEO values were similar in the presence and absence of phosphate or carbonate; however, they decreased slightly with nitrate presence. All these results suggest the feasibility of the combined UVC/PS process for the elimination of cyanide such as that found in mining wastewater

    Thermographic imaging in sports and exercise medicine: A Delphi study and consensus statement on the measurement of human skin temperature

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    This is an accepted manuscript of an article published by Elsevier in Journal of Thermal Biology on 18/07/2017, available online: https://doi.org/10.1016/j.jtherbio.2017.07.006 The accepted version of the publication may differ from the final published version.© 2017 Elsevier Ltd The importance of using infrared thermography (IRT) to assess skin temperature (tsk) is increasing in clinical settings. Recently, its use has been increasing in sports and exercise medicine; however, no consensus guideline exists to address the methods for collecting data in such situations. The aim of this study was to develop a checklist for the collection of tsk using IRT in sports and exercise medicine. We carried out a Delphi study to set a checklist based on consensus agreement from leading experts in the field. Panelists (n  =  24) representing the areas of sport science (n = 8; 33%), physiology (n = 7; 29%), physiotherapy (n = 3; 13%) and medicine (n = 6; 25%), from 13 different countries completed the Delphi process. An initial list of 16 points was proposed which was rated and commented on by panelists in three rounds of anonymous surveys following a standard Delphi procedure. The panel reached consensus on 15 items which encompassed the participants’ demographic information, camera/room or environment setup and recording/analysis of tsk using IRT. The results of the Delphi produced the checklist entitled “Thermographic Imaging in Sports and Exercise Medicine (TISEM)” which is a proposal to standardize the collection and analysis of tsk data using IRT. It is intended that the TISEM can also be applied to evaluate bias in thermographic studies and to guide practitioners in the use of this technique.Published versio

    Cinética de biodegradación de un nonilfenol polietoxilado en agua de río

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    [ES] En el presente trabajo se aborda el estudio cinético del proceso de biodegradación de uno de los tensioactivos sintéticos más consumidos en el mundo a nivel industrial, los alquilfenoles polietoxilados (APEO), en un medio natural como es el agua de río. El método de ensayo empleado ha sido el "River die away test" y para el análisis de la materia tensioactiva se ha empleado cromatografía líquida de alta resolución. El modelo cinético propuesto por los autores, ha sido aplicado a los datos de biodegradación obtenidos bajo diversas condiciones de temperatura y concentración inicial de materia activa. Los resultados muestran que el modelo se ajusta tanto a situaciones de periodos de inducción breves como prolongados y permite obtener parámetros cinéticos de interés como son, el contenido en substrato no biodegradable y la velocidad máxima de crecimiento microbiano.Manzano Quiñones, MA.; Perales Vargas-Machuca, JA.; Sales Márquez, D.; Quiroga Alonso, JM. (1998). Cinética de biodegradación de un nonilfenol polietoxilado en agua de río. Ingeniería del Agua. 5(3):27-32. https://doi.org/10.4995/ia.1998.2763SWORD273253Bayley, J. y Ollis, D. (1980) Biochemical Engineering Fundamentals. Ed. McGraw Hill.Gaden, E. (1959) Fermentation process kinetics. J. Biochem. Microbiol. Tech. Eng, 1. pp 63-70Larson, R. y Payne, A. (1981) Fate of the benzene ring of linear alkylbenzene sulfonate in natural waters. Appl. Environ. Microbiol, 41, 3, pp 621 -627.Okpokwasili, G.C. y Olisa, A.O. (1991) River-water biodegradation of surfactants in liquid detergents and shampoos. Water Research, 25.11, pp 1425-1429.Quiroga, J.M. y Sales, D. (1989) Ensayos de degradación con cepas puras de microorganismos. Ingeniería Química. Junio, pp 179-183.Quiroga, J.M. y Sales, D. (1991) Surfactant biodegradation in sea water. Tenside Surfactants Detergents, 28, 3, pp 200-203.Raymond, A. (1996) The global outlook for surfactant from a U.S. perspective. 4th World Surfactant Congress, Vol. 1, pp 21-36.Romero, L.; Perez, M.; Sales, D. (1997) Degradation kinetics of distillery wastewaters by immobilized anaerobic mixed cultures. The 8th International Conference on Anaerobic Digestion (AD-97). IAWQ. Japan, May.Schröder, H, Fr. (1993) Surfactants: non-biodegradable, significant pollutants in sewage treatment plant effluents. Journal of Chromatography, 647, pp 219-234.Sivak, A., Goyer, M. y Perwak, J. (1982) Environmental and human aspects of commercially important surfactants. Solution behaviour of surfactants. Ed. Plenum Publishing Corp.Vol 1, pp 161-188.Wang, Z. y Fingas, M. (1993) Rapid separation of non-ionic surfactants of polyethoxylated octylphenol and determination of ethylene oxide oligomer distribution by C1 column reversed-phase liquid chromatography. Journal of Chromatography, 637, pp 145-156.Yoshimura, K. (1986) Biodegradation and fish toxicity of nonionic surfactants. Japan Surface Active Agent Association. 63, 12, pp 1590-159
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