Submarine outfall of Mar del Plata (Argentina) : how did the construction impact on the intertidal benthic community?

Una solución adecuada al problema que deben resolver muchos países con respecto al tratamiento y el vertido de aguas cloacales, y su potencial impacto sobre el ambiente, podría ser verterlas por medio de emisarios submarinos. Hasta diciembre de 2014, los residuos cloacales de Mar del Plata se vertían de forma directa a la zona intermareal, sin tratamiento previo. En el año 2009 se comenzó a construir el emisario submarino (ES); la obra se inició con la incorporación de dos escolleras de abrigo y un frente de atraque. El ES, inaugurado en diciembre del 2014, descarga las aguas residuales sobre el submareal (4 km mar adentro). El objetivo de este trabajo fue evaluar los cambios en la estructura de la comunidad bentónica intermareal durante las distintas fases del proceso de construcción del ES (Antes, Durante y Después). Se consideraron tres sitios de muestreo localizados a diferentes distancias del efluente cloacal. Los resultados mostraron cambios en la comunidad bentónica intermareal como respuesta a la puesta en funcionamiento del ES. La abundancia de las especies sensibles a la contaminación aumentó en la etapa posterior a la puesta en funcionamiento del ES. Si bien la riqueza de especies alcanzó su pico máximo durante la fase de construcción del ES, la equitatividad y la diversidad aumentaron en la etapa posterior. Se observaron agrupamientos según la similitud en la composición específica según el factor etapa (Antes). Sin embargo, no se observaron agrupamientos con respecto a los sitios. En conclusión, los resultados obtenidos mostraron los cambios ocurridos en la estructura comunitaria intermareal asociados al nuevo vertido de aguas residuales generado por el emisario submarino construido en la ciudad.An adequate solution to the problem many countries must solve with respect to the treatment and discharge of sewage water, and its potential impacts on the environment, could be discharging them by means of submarine outfalls. Until December 2014, wastewater from Mar del Plata city was discharged untreated directly to the intertidal zone. In 2009, the construction of the submarine outfall (SO) began; two breakwaters and a docking front were built. The SO was inaugurated in December 2014 and the wastewater discharges directly over the subtidal (4 km offshore). The aim of this study was to evaluate the changes in the structure of the intertidal benthic community during the different phases of the SO construction [Before (A), During (Du) and After (De)]. Three sampling sites were located at different distances from the sewage effluent. The results showed changes in the intertidal benthic community in response to the functioning of the SO. The abundance of species sensitive to pollution increased in the posterior phase of the SO construction. Although the species richness peaked during the construction phase of the ES, evenness and diversity index increased in the subsequent phase (After). Groupings were observed according to the similarity in the specific composition according to the phase factor (Before, During and After). However, grouping of species according to the sites were not observed. In conclusion, the results obtained showed the changes occurred in the intertidal community structure associated with the new wastewater discharge generated by the submarine outfall built in the city

Validación y detección automática del transporte dispersivo del emisario submarino de Mar del Plata, Argentina

The submarine outfall of Mar del Plata city at Camet was projected considering the mean and maximum of forecasted sewage discharges, the inner-shelf depth, coliform concentration and its decay (T90) mainly induced by sunlight effect and costal salinity. In 2016 the outfall was operating with a length of 3,810 m and diffusers in the last 526 m. An economical method to monitor its performance in relation to the surroundings, is remote-sensing techniques, applying either visible or radar images. Tidal currents parallel to the coast are responsible for the transport of the sedimentary plume in the far field, after a primary dilution from a depth of 11 m. Visible images (1.5 to 6 m spatial resolution) are effective in monitoring the plume entrained in the upper portion of the water column. These analyses led to study the interaction between waves and coastal currents. Radar images (30 m resolution X and C bands) permit to survey the slick-alike plume that differs from the environment water by the surface roughness. Comparing both techniques visible images can distinguish the different colours of the plume; instead, the radar images are showing the surface roughness from the slick-alike plume. The main advantage of active sensors is that they can map the plume during a cloudy weather and even during night time.El emisario submarino de Mar del Plata en Camet fue proyectado considerando las descargas cloacales promedio y máximas previstas, la profundidad de la plataforma vecina, la concentración de coliformes y el decaimiento (T90) inducido por la luz solar y la salinidad. En 2016 el emisario operaba con una longitud de 3.810 m con difusores en los últimos 526 m. Un método poco oneroso para analizar su comportamiento en relación a su entorno es la aplicación de técnicas de teledetección tanto en el espectro visible como mediante imágenes de radar. Las corrientes de marea paralelas a la costa son responsables de una pluma sedimentaria en el campo lejano, luego de una dilución primaria desde una profundidad de 11 m. Las imágenes visibles (resolución espacial de 1,5 a 6 m) son efectivas para monitorear la pluma extendida en la capa superior del mar. Estos análisis permiten el estudio de la interacción entre olas y corrientes costeras. Las imágenes de radar (resolución de 30 m en las bandas X y C) permiten relevar plumas superficiales semejantes a derrames de aceites por su rugosidad. Comparando ambas técnicas las imágenes visibles pueden distinguir plumas de diferentes colores del agua; por el contrario, las imágenes de radar están mostrando diferencias en la tensión superficial. La principal ventaja de los sensores activos es que permiten monitorear la pluma durante tiempo nuboso incluso sin luz solar

Continental Origin for Q Haplogroup Patrilineages in Argentina and Paraguay

Haplogroup Q originated in Eurasia around 30,000 years ago. It is present in Y-chromosomes from Asia and Europe at rather low frequencies. Since America is undoubtedly one of the continents where this haplogroup is highly represented, it has been defined as one of the founding haplogroups. Its M3 clade has been early described as the most frequent, with Pan-American representation. However, it was also possible to find several other haplogroup Q clades at low frequencies. Numerous mutations have been described for haplogroup Q, allowing the analysis of its variability and the assignment of its geographic origin. We have analyzed 442 samples belonging to haplogroup Q of unrelated men from Argentina and Paraguay, but this work is specifically referred to 27 Q (xM3) lineages. We tested 3 SNPs by APLP, 3 for RFLP, 15 SNPs by Sanger sequencing, and 17 STRs. Our approach allowed us to identify 5 sub-haplogroups. Q-M3 and Q-CTS2730/Z780 are undoubtedly autochthonous lineages and represent the most frequent sub-haplogroups. With significant representation in self-defined aboriginal populations, their autochthonous status has been previously described. The aim of present work is to identify the continental origin of the remaining Q lineages. Thus, we analyzed the STR haplotypes for the samples of our series and compared them with haplotypes described by other authors for the rest of the world. Even when haplogroup Qs have been extensively studied in America, some of them could have their origin in post Columbian human migration from Europe and Middle East

Characteristics, management, and outcomes of patients with left‐sided infective endocarditis complicated by heart failure: a substudy of the ESC‐EORP EURO‐ENDO (European infective endocarditis) registry

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