Distribution and population structure of the crab Halicarcinus planatus (Brachyura, Hymenosomatidae) in the Beagle Channel, Tierra del Fuego

El cangrejo Halicarcinus planatus es el único himenosomátido que habita el extremo austral de Sudamérica, con una distribución subantártica, incluyendo las islas periantárticas y Nueva Zelanda. En este trabajo, se presenta información sobre la abundancia y estructura poblacional de H. planatus en el intermareal de Bahía Brown, Canal Beagle, Tierra del Fuego durante un año. Además, se muestran las variaciones en la estructura poblacional en otras playas y ambientes del canal. A diferencia de los machos, la densidad de hembras mostró fluctuaciones mensuales en el intermareal de Bahía Brown y fue mayor durante los meses de verano. Las altas densidades de H. planatus podrían relacionarse con la baja mortalidad de estadios larvales y las características oceanográficas de la bahía, probablemente aumentado por la presencia de bancos y cuerdas de cultivo de mejillones, sustratos donde ocurriría el asentamiento de H. planatus. La proporción de sexos poblacional estuvo sesgada hacia las hembras solo en verano, mientras que la proporción sexual operativa se sesgó hacia los machos durante casi todo el período estudiado, sugiriendo una fuerte competencia entre machos por el apareamiento. A su vez, los machos solo estuvieron presentes en el intermareal de Bahía Brown y en los grampones de Macrocystis pyrifera pero no se encontraron en el resto de los intermareales estudiados, probablemente relacionado con la ausencia de refugio en el submareal de Bahía Brown. El reclutamiento existiría en dos períodos diferentes, verano (enero-febrero) y otoño-invierno (mayo-junio), que se corresponde con las dos cohortes larvales de H. planatus presentes en el Canal Beagle.The crab Halicarcinus planatus is the only hymenosomatid that inhabits the southern tip of South America and has a sub-Antarctic distribution, including the peri-Antarctic islands and New Zealand. In this paper, we report the abundance and population structure of H. planatus for a year in the intertidal zone of Bahía Brown, Beagle Channel, Tierra del Fuego. Moreover, we show variations in the population structure in other beaches and environments of the channel. In contrast with males, female density showed monthly variations and was higher during austral summer months. High densities of H. planatus could be related with low mortality during the larval stage and oceanographic features of Bahía Brown, probably enhanced by the presence of both culture and mussel beds, substrates where settlement would occur. The populational sex ratio was biased towards females only in summer, while the operational sex ratio was biased towards males during all periods studied, suggesting strong competition among males for mating. In turn, males were present only in the intertidal zone of Bahía Brown and Macrocystis pyrifera but were absent in the other studied intertidal areas.This is perhaps related to the lack of shelter in the subtidal zone of Bahía Brown. Recruitment occurs in two different periods, summer (January-February) and autumn-winter (May-June), which corresponds with the two larval cohorts of H. planatus in the Beagle Channel.Fil: Diez, Mariano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Florentin, Olga Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Selection of white-rot fungi to formulate complex and coated pellets for Reactive Orange 165 decolourization

Six strains of white-rot fungi isolated from southern Chile were evaluated for their ergosterol/biomass correlation and ligninolytic potential in solid medium to formulate pellets for Reactive Orange 165 (RO165) decolourization. The fungus Anthracophyllum discolor was selected to formulate complex pellets (fungal mycelium, sawdust, and activated carbon), coated pellets (complex pellet + alginate) and simple pellets (fungal mycelium). The activity of ligninolytic enzymes (laccase, manganese peroxidase, manganese-independent peroxidase, and lignin peroxidase) was evaluated in both the complex and coated pellets in modified Kirk medium, and the morphology of the pellets was studied using scanning electron microscopy (SEM). Complex pellets of A. discolor showed a higher enzymatic production mainly MnP (38 U L-1 at day 15) compared to coated and simple pellets. Examinations using SEM showed that both pellets produced a black core that was entrapped by a layer of fungal mycelium. Decolourization of RO165 was demonstrated with all the pellets formulated. However, the highest and fastest decolourization was obtained with complex pellets (100% at day 8). Therefore, complex pellets of A. discolor can be used for the biological treatment of wastewater contaminated with RO165.This research was supported by a FONDECYT grant 1090678 and a Doctoral thesis fellowship CONICYT 24100149

Biogenic silver nanoparticles associated with silver chloride nanoparticles (Ag@AgCl) produced by laccase from Trametes versicolor

In the present study, semi-purified laccase from Trametes versicolor was applied for the synthesis of silver nanoparticles, and the properties of the produced nanoparticles were characterized. All of the analyses of the spectra indicated silver nanoparticle formation. A complete characterization of the silver nanoparticles showed that a complex of silver nanoparticles and silver ions was produced, with the majority of the particles having a Ag(2+) chemical structure. A hypothetical mechanistic scheme was proposed, suggesting that the main pathway that was used was the interaction of silver ions with the T1 site of laccase, producing silver nanoparticles with the concomitant inactivation of laccase activity and posterior complexing with silver ions

Elaboración de un programa de intervención

El presente trabajo está enfocado en el área sensoriomotor, siguiendo las bases de la Estimulación Temprana desde la Terapia Ocupacional. Está dirigido a favorecer las destrezas motrices que permitan potenciar la independencia del niño, además de aportar conocimientos del desarrollo evolutivo. Se considera y se pone en marcha una intervención específica a un usuario, indicada a sus necesidades, para después detallar los objetivos planteados en el informe del caso, y se detallaran en él las características. En la actividad realizada se tendrá en cuenta la metodología, las actividades propuestas y la evaluación analizando los resultados obtenidos mediante las diferentes herramienta

Co-Infections by Fusarium circinatum and Phytophthora spp. on Pinus radiata: Complex Phenotypic and Molecular Interactions

This study investigated the complex phenotypic and genetic response of Monterey pine (Pinus radiata) seedlings to co-infections by F. circinatum, the causal agent of pine pitch canker disease, and the oomycetes Phytophthora xcambivora and P. parvispora. Monterey pine seedlings were wound-inoculated with each single pathogen and with the combinations F. circinatum/P. xcambivora and F. circinatum/P. parvispora. Initially, seedlings inoculated only with F. circinatum showed less severe symptoms than seedlings co-inoculated or inoculated only with P. xcambivora or P. parvispora. However, 30 days post-inoculation (dpi), all inoculated seedlings, including those inoculated only with F. circinatum, showed severe symptoms with no significant differences among treatments. The transcriptomic profiles of three genes encoding pathogenesis-related proteins, i.e., chitinase (PR3), thaumatin-like protein (PR5), phenylalanine ammonia-lyase (PAL), and the pyruvate decarboxylase (PDC)-encoding gene were analyzed at various time intervals after inoculation. In seedlings inoculated with single pathogens, F. circinatum stimulated the up-regulation of all genes, while between the two oomycetes, only P. xcambivora induced significant up-regulations. In seedlings co-inoculated with F. circinatum and P.xcambivora or P. parvispora none of the genes showed a significant over-expression 4 dpi. In contrast, at 11 dpi, significant up-regulation was observed for PR5 in the combination F. circinatum/P.xcambivora and PDC in the combination F. circinatum/P. parvispora, thus suggesting a possible synergism of multiple infections in triggering this plant defense mechanism

Carbendazim dissipation in the biomixture of on-farm biopurification systems and its effect on microbial communities

The impact of repeated carbendazim (CARB) applications on the extent of \CARB\ dissipation, the microbial diversity, the community level physiological profile (CLPP), and the enzymatic activity within the biomixture of an on-farm biopurification system was evaluated. After three successive \CARB\ applications, the \CARB\ dissipation efficiency was high; the efficiency of dissipation was 87%, 94% and 96% after each application, respectively. Although microbial enzymatic activity was affected significantly by \CARB\ application, it could recover after each \CARB\ pulse. Likewise, the numbers of cultivable bacteria, fungi and actinomycetes (as measured in CFUs) were slightly affected by the addition of CARB, but the inhibitory effect of the pesticide application was temporary. Denaturing gradient gel electrophoresis (DGGE) and Biolog Ecoplate assays demonstrated that the microbial populations remained relatively stable over time when compared to the control. The results obtained herein therefore demonstrate the high dissipation capacity of this biomixture and highlight the microbiological robustness of this biological system.This work was supported by FONDECYT project No 11100236

Fouling control of submerged and side-stream membrane bioreactors based on the statistical analysis of mid-term assays

The response surface methodology has been applied to study reversible and irreversible fouling rates caused by anaerobic sludge in membrane bioreactors, with the aim of controlling membrane fouling by adjusting filtration conditions. The challenge of obtaining statistically significant results of long-term fouling by means of mid-term assays has been addressed. The individual and combined effects of the filtration flux, backwashing intensity, gas sparging and crossflow velocity on membrane fouling, were analyzed in two types of membranes: an external tubular membrane and a submerged hollow fiber membrane. In the external membrane, the reversible fouling rate was as low as 0.27 ± 0.10 mbar/min, depending mainly on the filtration flux and gas sparging. However, the principal control parameter of the irreversible fouling rate was the crossflow velocity, reaching 2.12 ± 1.75 1012 m−2 in terms of increase of resistance per cubic meter filtered by square meter of membrane. In the submerged membrane, the irreversible fouling rate was quite lower, 0.78 ± 0.40 mbar/d, despite the reversible fouling rate was higher, 1.26 ± 0.42 mbar/min. In this case, the irreversible fouling depended mainly on the backwashing frequency despite the reversible fouling was more affected by the filtration flux and gas sparging. Hence, the approach used to control the reversible fouling rate does not involve mitigating irreversible fouling on both submerged and external membranes. This study provides a methodological basis for the selection of site-specific operating conditions, under which sustainable operation of membrane bioreactors could be achieved.TCUE 2018–2020 cofounded by European Regional Development Fund (ERDF) and Junta de Castilla y León (Spain) and the inestimable collaboration of Campofrío Frescos and Grupo Ecoalia

Defensas antioxidantes y peroxidación de lípidos en dos especies de Lithodes del Atlántico Sur durante el verano

En el sur de Sudamérica Lithodes santolla y L. confundens representan las especies de centollas más apreciadas, debido a sus altos rendimientos y aceptación en los mercados. Desde un punto de vista fisiológico, las especies reactivas del oxígeno (ROS) son continuamente producidas como productos de la respiración celular. Estos ROS se transforman en metabolitos menos tóxicos por medio de enzimas antioxidantes. El objetivo fue determinar en Lithodes santolla (del Golfo San Jorge) y L. confundens (de la costa atlántica de Tierra del Fuego) el nivel de base de la actividad enzimática antioxidante y los niveles de peroxidación de lípidos. Las enzimas catalasa (CAT) y glutatión-S-transferasa (GST) y la peroxidación de lípidos se midieron en branquias, músculo y hepatopáncreas. Ambas especies mostraron actividad enzimática antioxidante, mientras que las branquias presentaron la mayor actividad enzimática de CAT. La actividad de CAT y GST fue mayor en L. confundens en el músculo y branquias respectivamente, comparado con L. santolla; mientras que la peroxidación de lípidos fue menor en ambos órganos. Estas diferencias entre ambas especies sugieren que L. confundens sería más eficiente ante situaciones de estrés oxidativo, debido probablemente a los periodos de anoxia que experimenta durante las bajas mareas de primavera. Además, estas diferencias podrían ser atribuidas a características intrínsecas de adaptación de cada especie de centolla y/o a condiciones ambientales de cada área de estudio en particular. Parámetros como CAT, GST y peroxidación de lípidos podrían proponerse como biomarcadores de estrés oxidativo en Lithodes santolla y L. confundens.In Southern South America Lithodes santolla and L. confundens are the most valuable king crabs species, specially due to their high yields and their high acceptance in the markets. From a physiological point of view, reactive oxygen species (ROS) are continuously produced as by-products of cell respiration. These ROS are transformed into less toxic metabolites by antioxidant enzymes. The aim of the present study was to determine in Lithodes santolla (from San Jorge Gulf) and L. confundens (from Atlantic coast of Tierra del Fuego) the baseline status of both antioxidant enzyme activity and lipid peroxidation levels. Activities of catalase (CAT), glutathione-S-transferase (GST), as well as lipid peroxidation were measured in the muscle, gills and hepatopancreas. Both species showed antioxidant enzyme activities, and the gills were the organs with the highest CAT enzyme activities. CAT and GST activities were higher in muscle and gills, respectively, in L. confundens compared with L. santolla, whereas lipid peroxidation was low in both organs. These differences between both species suggest that L. confundens is more capable to afford oxidative stress than L. santolla, which may be a response to the common occurrence of L. confundens at the intertidal during the spring low tides. Differences in the analysed parameters could be attributed to intrinsic adaptation features of each king crab species and/or to environmental conditions of each particular study area. Furthermore, our results showed that parameters as CAT, GST and lipid peroxidation could be proposed as biomarkers of oxidative stress in Lithodes santolla and L. confundens.Fil: Romero, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Schvezov, Natasha. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Sotelano, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Diez, Mariano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Florentin, Olga Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Tapella, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

Association of Sleep Duration and Quality With Alterations in the Hypothalamic-Pituitary Adrenocortical Axis: The Multi-Ethnic Study of Atherosclerosis (MESA)

Context: Short sleep duration and poor sleep quality are associated with cardiovascular outcomes. One mechanism proposed to explain this association is altered diurnal cortisol secretion. Objective: The objective of the study was to examine the associations of sleep duration and sleep quality with diurnal salivary cortisol levels. Design: This was a cross-sectional analysis using data from examination 5 (2010–2012) of the Multi-Ethnic Study of Atherosclerosis. Actigraphy-based measures of sleep duration and efficiency were collected over 7 days, and salivary cortisol samples were collected over 2 days from participants aged 54–93 years (n = 600 with analyzable data). Results: Shorter average sleep duration (<6 h/night) was associated with less pronounced late decline in cortisol [2.2% difference in slope; 95% confidence interval (CI) 0.8–3.7; P ≤ .01] and less pronounced wake-to-bed slope (2.2% difference; 95% CI 1.0–3.4; P ≤ .001) compared with longer sleep duration (≥6 h/night). Lower sleep efficiency (<85%) was associated with less pronounced early decline in cortisol (29.0% difference in slope; 95% CI 4.1–59.7; P < .05) compared with higher sleep efficiency (≥85%). Subjects reporting insomnia had a flatter cortisol awakening response (−16.1% difference in slope; 95% CI −34.6 to −0.1; P < .05) compared with those not reporting insomnia. Conclusions: Shorter sleep duration, lower sleep efficiency, and insomnia are associated with alterations in diurnal cortisol levels consistent with changes in hypothalamic-pituitary-adrenal regulation

Selection of white-rot fungi to formulate complex and coated pellets for Reactive Orange 165 decolourization

Abstract Six strains of white-rot fungi isolated from southern Chile were evaluated for their ergosterol/biomass correlation and ligninolytic potential in solid medium to formulate pellets for Reactive Orange 165 (RO165) decolourization. The fungus Anthracophyllum discolor was selected to formulate complex pellets (fungal mycelium, sawdust, and activated carbon), coated pellets (complex pellet + alginate) and simple pellets (fungal mycelium). The activity of ligninolytic enzymes (laccase, manganese peroxidase, manganese-independent peroxidase, and lignin peroxidase) was evaluated in both the complex and coated pellets in modified Kirk medium, and the morphology of the pellets was studied using scanning electron microscopy (SEM). Complex pellets of A. discolor showed a higher enzymatic production mainly MnP (38 U L-1 at day 15) compared to coated and simple pellets. Examinations using SEM showed that both pellets produced a black core that was entrapped by a layer of fungal mycelium. Decolourization of RO165 was demonstrated with all the pellets formulated. However, the highest and fastest decolourization was obtained with complex pellets (100% at day 8). Therefore, complex pellets of A. discolor can be used for the biological treatment of wastewater contaminated with RO165