Cambios en el perfil de ácidos grasos del músculo de Holothuria forskali tras una exposición aguda a mercurio

The present study aimed to document the interaction between mercury (Hg), as a model chemical stressor to an aquatic organism, and Fatty acid (FA) profile in the longitudinal muscle of the sea cucumber Holothuria forskali. To assess the sensitivity of this species to the toxic effects of Hg, young H. forskali were exposed to gradual doses of Hg (40, 80 and160 µg·L-1) for 96 h. The results showed that following Hg exposure, the FA profile of H. forskali corresponded to an increase in the level of saturated fatty acids, and the decrease in the level of monounsaturated and polyunsaturated fatty acids. The most prominent changes in the FA composition were recorded at the lowest dose with noticeable decreases in linoleic, arachidonic and eicosapentaenoic acid levels and an increase of docosahexaenoic acid. The occurrence of a state of oxidative stress induced by Hg contamination was evidenced by the enhanced levels of malondialdehyde, hydrogen peroxide and lipid hydroperoxide. Overall, the low concentration of mercury exerted the most obvious effects on lipid metabolism, suggesting that changes in fatty acid composition may be act as an early biomarker to assess mercury toxicity in this ecologically and economically important species.El presente estudio tuvo como objetivo demostrar la interacción entre el mercurio (Hg), como modelo de estresor químico para el organismo acuático, y el perfil de ácidos grasos (FA) en el músculo longitudinal del pepino de mar Holothuria forskali. Para evaluar la sensibilidad de esta especie a los efectos tóxicos del Hg, los juveniles de H. forskali fueron expuestos a dosis graduales de Hg (40, 80 y 160 µg·L-1) durante 96 h. Los resultados mostraron que después de la exposición al Hg, el perfil de FA de H. forskali respondió con una tendencia direccional anclada por el aumento en el nivel de ácidos grasos saturados y la disminución en el nivel de ácidos grasos monoinsaturados y poliinsaturados. Los cambios más prominentes en la composición de AG se registraron a la dosis más baja con una disminución notable en los niveles de ácido linoleico, araquidónico y eicosapentaenoico frente a un aumento de ácido docosahexaenoico. La aparición de un estado de estrés oxidativo inducido por la contaminación con Hg se puso de manifiesto por el aumento en los niveles de malondialdehído, peróxido de hidrógeno e hidroperóxido de lípidos. En general, la concentración más baja de mercurio ejerció efectos más obvios sobre el metabolismo de los lípidos, lo que sugiere que los cambios en la composición de los ácidos grasos pueden actuar como un biomarcador anterior para evaluar la toxicidad del mercurio en esta especie de importancia ecológica y económica

Influence of the Linker Length on the Cytotoxicity of Homobinuclear Ruthenium(II) and Gold(I) Complexes

Dinudear metal complexes have emerged as a promising class of anticancer compounds with the ability to cross-link biomolecular targets. Here, we describe two novel series of phosphine-linked dinudear ruthenium(II) p-cyrnene and gold(I) complexes, in which the length of the connecting poly(ethylene glycol) chain has been systematically modified. The impact,Of the multinuclearity, lipophilicity, and linker length on the antiproliferative activity of the compounds-on tumorigenic,(A2780 and A2780cisR) and nonturnorigenic (HEK-293) cell lines was assessed. The dinuclear ruthenium(II) complexes were considerably more cytotoxic than their mononuclear : counterparts, and a correlation between the lipophilicity of the linker and the cytotoxicity was observed, whereas the cytotoxicity of the gold(I) series, is independent of these factors

Cambios en la composición de los ácidos grasos y evaluación de la oxidación de lípidos y proteínas en almejas comerciales (Ruditapes decussatus) cocinadas

This study aimed to provide information about the changes in fatty acid composition and quality in Ruditapes decussatus tissue after four culinary treatments (steamed, baked, grilled and fried). All treated samples showed a significant decrease in moisture and protein. In contrast, a significant increase in fat content resulted from the grilled and fried treatments. Saturated fatty acid was significantly higher in fresh clams than all cooking processes, except in fried ones. Monounsaturated fatty acid and polyunsaturated fatty acid varied significantly between fresh and cooked clams with high values recorded for fried clams. The n-3/n-6 ratio, peroxide index, EPA+DHA and atherogenicity index decreased significantly after the cooking processes particularly in fried clams. The mineral levels (Mg, Ca and Mn) of cooked clams decreased considerably with grilled and fried treatments. The impacts of cooking on the fatty acid composition and protein content in clam tissue was evaluated by lipid peroxidation (TBARS, PV, FFA, TOR) and protein oxidation (AOPP and PCO), which varied statistically in fried, steamed, grilled and baked samples; indicating alterations in cooked clam tissues structure. Based on our results, steaming is recommended for the preparation of clams because it preserves the most nutritional tissue quality.El presente estudio tuvo como objetivo proporcionar información innovadora sobre los cambios en la composición y calidad de los ácidos grasos presentes en el tejido de Ruditapes decussatus tras cuatro tratamientos culinarios distintos (vapor, horno, parrilla y fritura). Todas las muestras tratadas mostraron una disminución significativa en el contenido de humedad y proteínas. Por el contrario, los tratamientos a la parrilla y frito resultaron en un aumento significativo de la cantidad de grasa. El contenido en ácidos grasos saturados fue significativamente mayor en las almejas frescas comparado con todas las almejas cocinadas, a excepción de las fritas. Los ácidos grasos mono- y poliinsaturados variaron significativamente entre las almejas frescas y cocinadas, mostrando el valor más alto en las almejas fritas. La relación n-3/n-6, el índice de peróxidos, el contenido de EPA + DHA y el índice de aterogenicidad disminuyeron significativamente después de todos los procesos de cocción, especialmente en las almejas fritas. Los niveles de minerales (Mg, Ca y Mn) de las almejas cocinadas disminuyeron considerablemente tras los tratamientos a la parrilla y frito. El impacto del cocinado sobre la calidad de los ácidos grasos y las proteínas se evaluó mediante la medida de la peroxidación de lípidos (TBARS, PV, FFA, TOR) y la oxidación de proteínas (AOPP y PCO), valores que variaron significativamente en las muestras fritas, al vapor, a la parrilla y al horno, indicando una alteración de la estructura de los tejidos de la almeja cocinada. De acuerdo a los resultados obtenidos, se recomienda la cocción al vapor para la preparación de las almejas, ya que es el tratamiento que mejor preserva calidad nutricional de los tejidos

Data-based investigation of the effects of canopy structure and shadows on chlorophyll fluorescence in a deciduous oak forest

Data from satellite, aircraft, drone, and ground-based measurements have already shown that canopy-scale sun-induced chlorophyll fluorescence (SIF) is tightly related to photosynthesis, which is linked to vegetation carbon assimilation. However, our ability to effectively use those findings are hindered by confounding factors, including canopy structure, fluctuations in solar radiation, and sun–canopy geometry that highly affect the SIF signal. Thus, disentangling these factors has become paramount in order to use SIF for monitoring vegetation functioning at the canopy scale and beyond. Active chlorophyll fluorescence measurements (FyieldLIF), which directly measures the apparent fluorescence yield, have been widely used to detect physiological variation of the vegetation at the leaf scale. Recently, the measurement of FyieldLIF has become feasible at the canopy scale, opening up new opportunities to decouple structural, biophysical, and physiological components of SIF at the canopy scale. In this study, based on top-of-canopy measurements above a mature deciduous forest, reflectance (R), SIF, SIF normalized by incoming photosynthetically active radiation (SIFy), FyieldLIF, and the ratio between SIFy and FyieldLIF (named Φk) were used to investigate the effects of canopy structure and shadows on the diurnal and seasonal dynamics of SIF. Further, random forest (RF) models were also used to not only predict FyieldLIF and Φk, but also provide an interpretation framework by considering additional variables, including the R in the blue, red, green, red-edge, and near-infrared bands; SIF; SIFy; and solar zenith angle (SZA) and solar azimuth angle (SAA). Results revealed that the SIF signal is highly affected by the canopy structure and sun–canopy geometry effects compared to FyieldLIF. This was evidenced by the weak correlations obtained between SIFy and FyieldLIF at the diurnal timescale. Furthermore, the daily mean SIF‾y captured the seasonal dynamics of daily mean F‾yieldLIF and explained 58 % of its variability. The findings also revealed that reflectance in the near-infrared (R-NIR) and the NIRv (the product of R-NIR and normalized difference vegetation index (NDVI)) are good proxies of Φk at the diurnal timescale, while their correlations with Φk decrease at the seasonal timescale. With FyieldLIF and Φk as outputs and the abovementioned variables as predictors, this study also showed that the RF models can explain between 86 % and 90 % of FyieldLIF, as well as 60 % and 70 % of Φk variations under clear-sky conditions. In addition, the predictor importance estimates for FyieldLIF RF models revealed that R at 410, 665, 740, and 830 nm; SIF; SIFy; SZA; and SAA emerged as the most useful and influential factors for predicting FyieldLIF, while R at 410, 665, 705, and 740 nm; SZA; and SAA are crucial for predicting Φk. This study highlighted the complexity of interpreting diurnal and seasonal dynamics of SIF in forest canopies. These dynamics are highly dependent on the complex interactions between the structure of the canopy, the vegetation biochemical properties, the illumination angles (SZA and SAA), and the light conditions (ratio of diffuse to direct solar radiation). However, such measurements are necessary to better separate the variability in SIF attributable to radiation and measurement conditions from the subtler variability attributable to plant physiological processes.</p

Molecular analysis of Mycobacterium isolates from extrapulmonary specimens obtained from patients in Mexico

<p>Abstract</p> <p>Background</p> <p>Little information is available on the molecular epidemiology in Mexico of <it>Mycobacterium </it>species infecting extrapulmonary sites in humans. This study used molecular methods to determine the <it>Mycobacterium </it>species present in tissues and body fluids in specimens obtained from patients in Mexico with extrapulmonary disease.</p> <p>Methods</p> <p>Bacterial or tissue specimens from patients with clinical or histological diagnosis of extrapulmonary tuberculosis were studied. DNA extracts from 30 bacterial cultures grown in Löwenstein Jensen medium and 42 paraffin-embedded tissues were prepared. Bacteria were cultured from urine, cerebrospinal fluid, pericardial fluid, gastric aspirate, or synovial fluid samples. Tissues samples were from lymph nodes, skin, brain, vagina, and peritoneum. The DNA extracts were analyzed by PCR and by line probe assay (INNO-LiPA MYCOBACTERIA v2. Innogenetics NV, Gent, Belgium) in order to identify the <it>Mycobacterium </it>species present. DNA samples positive for <it>M. tuberculosis </it>complex were further analyzed by PCR and line probe assay (INNO-LiPA Rif.TB, Innogenetics NV, Gent, Belgium) to detect mutations in the <it>rpo</it>B gene associated with rifampicin resistance.</p> <p>Results</p> <p>Of the 72 DNA extracts, 26 (36.1%) and 23 (31.9%) tested positive for <it>Mycobacterium species </it>by PCR or line probe assay, respectively. In tissues, <it>M. tuberculosis </it>complex and <it>M. genus </it>were found in lymph nodes, and <it>M. genus </it>was found in brain and vagina specimens. In body fluids, <it>M. tuberculosis </it>complex was found in synovial fluid. <it>M. gordonae</it>, <it>M. smegmatis</it>, <it>M. kansasii</it>, <it>M. genus</it>, <it>M. fortuitum/M. peregrinum </it>complex and <it>M. tuberculosis </it>complex were found in urine. <it>M. chelonae/M. abscessus </it>was found in pericardial fluid and <it>M. kansasii </it>was found in gastric aspirate. Two of <it>M. tuberculosis </it>complex isolates were also PCR and LiPA positive for the <it>rpo</it>B gene. These two isolates were from lymph nodes and were sensitive to rifampicin.</p> <p>Conclusion</p> <p>1) We describe the <it>Mycobacterium </it>species diversity in specimens derived from extrapulmonary sites in symptomatic patients in Mexico; 2) Nontuberculous mycobacteria were found in a considerable number of patients; 3) Genotypic rifampicin resistance in <it>M. tuberculosis </it>complex infections in lymph nodes was not found.</p

Influence of The Association of The EVA and NBR on The Characteristics of Modified Bitumen

Durability and the performance of pavement depend mainly on the characteristics of materials which change over time like all other organic substances. They are subject to significant changes due to environmental conditions during the different phases of use. In the present work we investigated experimentally the influence of the association of ethyl vinyl acetate polymer (EVA) with an industrial waste, acrylonitrile-butadiene rubber (NBR) on the modification of bitumen AC 35-50 and its rheological behavior. The incorporation of NBR and EVA in the bitumen improved its intrinsic characteristics (softening point, penetration and ductility). In addition to improving the characteristics of bituminous binders that will affect the durability of bituminous structures, the environment will be preserved by the recycling of industrial waste

TCP flow control technique for an interworking interface: hardware implementation

Current TCP flow control depends on packet losses to find the workload that a network can support. A variety of situations, including lossy wireless networks, asymmetric networks and web traffic workload, violates many of the assumptions made by TCP, causing degraded end-to-end performances. To improve the performance of TCP over heterogeneous networks (Ethernet and ATM interconnection), we propose a new technique, which we call Vegas-Snoop+, based on Vegas and Snoop protocols. Two modified service elements take part on the Vegas-Snoop+ echnique. First, Vegas service element manages the connection parameters to achieve better throughput. Second, Snoop service element isolates the Ethernet senders from the characteristics of the ATM link. The objective in this paper is to win from advantages of Vegas and Snoop protocols, as well as to search an interconnection interface for networks interoperability. Actually, the development of two new integrated circuits (the BCM5680 (switch) and the BCM5401 (PHY)) orientate researchers to implement, at higher layer of the OSI model, flow control mechanisms to ensure reliability. Vegas-Snoop+ is an implementation of TCP, which gives in this way a solution for traffic management and congestion control improving good throughput with more reliabilit