Cephalopods are a group of marine invertebrates that have received little attention as sentinel species in comparison to other molluscs, such as bivalves. Consequently, their physiological and ...biochemical xenobiotic metabolism responses are poorly understood. Here we undertake a comparative analysis of the enzymatic activities involved in detoxification reactions and neural transmission in the digestive tract of two commercial cephalopods: the Common octopus, Octopus vulgaris, and the European cuttlefish, Sepia officinalis. For methodological purposes, several common B-esterases (five carboxylesterase (CE) substrates and three cholinesterase (ChE) determinations) were assayed as a proxy of metabolic and neuronal activities, respectively. Four components of the digestive tract in each species were considered: salivary glands, the stomach, the digestive gland and the caecum. The in vitro responses of digestive gland homogenates to model chemicals and contaminants of environmental concern were contrasted between both cephalopod species. The baseline biochemical activities in the four digestive tract components were also determined. Moreover, in order to validate the protocol, purified proteins, recombinant human CE (CE1 and CE2) and purified eel acetylcholinesterase (AChE) were included in the analysis. Overall, carboxylesterase activities were higher in octopus than in cuttlefish, with the activity quantified in the digestive tract components in the following order: digestive gland ≈ caecum > stomach ≈ salivary glands, with higher hydrolysis rates reached with naphthyl-derived substrates. In contrast, cuttlefish hydrolysis rates with ChE substrates were higher than in octopus. This trend was also reflected in a higher sensitivity to CE inhibitors in octopus and to AChE inhibitors in cuttlefish. Given the detoxification character of CEs and its protective role preventing AChE inhibition, octopus could be regarded as more efficiently protected than cuttlefish from neurotoxic exposures. A full characterisation of B-esterases in the digestive tract of the two common cephalopods is also provided.
•First time B-esterases characterisation in the digestive tract of two cephalopods.•Octopus carboxylesterase was sensitive to chemicals of environmental concern.•Cuttlefish acetylcholinesterase was sensitive to neurotoxic chemicals.•The flame retardant TBBPA interferes in vitro with carboxylesterases.•Cuttlefish AChE in vitro sensitive to organophosphorus flame retardants.
Abstract
Cuttlefish are an important global fisheries resource, and their demand is placing increasing pressure on populations in many areas, necessitating conservation measures. We reviewed evidence ...from case studies spanning Europe, Africa, Asia, and Australia encompassing diverse intervention methods (fisheries closures, protected areas, habitat restoration, fishing-gear modifications, promoting egg survival, and restocking), and we also discuss the effects of pollution on cuttlefish. We conclude: (1) spatio-temporal closures need to encompass substantial portions of a species’ range and protect at least one major part of their life cycle; (2) fishing-gear modifications have the potential to reduce unwanted cuttlefish capture, but more comprehensive trials are needed; (3) egg survival can be improved by diverting and salvaging from traps; (4) existing lab rearing and restocking may not produce financially viable results; and (5) fisheries management policies should be regularly reviewed in light of rapid changes in cuttlefish stock status. Further, citizen science can provide data to reduce uncertainty in empirical assessments. The information synthesized in this review will guide managers and stakeholders to implement regulations and conservation initiatives that increase the productivity and sustainability of fisheries interacting with cuttlefish, and highlights gaps in knowledge that need to be addressed.
Ser director es una tarea altamente demandante y estresante, especialmente por la gran cantidad de conflictos que requieren afrontar en el desempeño de ese rol. El objetivo de esta investigación fue ...identificar los tipos de conflictos que enfrentan los directores con distintos actores de la comunidad, analizando el nivel de intensidad y su frecuencia. Mediante una encuesta en línea enviada a directores de establecimientos municipalizados de Chile (n=395) se constata que los conflictos con los adultos son más intensos que con los estudiantes. Dentro de los actores adultos, los apoderados (41,5%) son los más conflictivos. Los tipos de conflictos que enfrentan los directores con estos actores se relacionan con denuncias realizadas por estos, la resistencia en acatar y seguir las directrices de la escuela, situaciones de violencia en contra de la escuela, problemas de comunicación, falta de compromiso con la tarea educativa y, finalmente, con la negligencia de la escuela ante situaciones específicas con los estudiantes. Las conclusiones del estudio evidencian la necesidad de desarrollar una comprensión más profunda de los tipos de conflictos y estrategias de resolución empleadas por los líderes escolares.
En este estudio se obtuvieron políticas de operación del tipo curvas Z, usando dos métodos de optimización: el de gradiente reducido generalizado (GRG) no lineal y un algoritmo genético (AG) simple, ...y se aplicaron a un sistema de aprovechamiento hidráulico localizado en la cuenca del lago de Cuitzeo, que juega un papel importante en el abastecimiento de agua a una parte de la población de la ciudad de Morelia y en el riego de varios módulos del Distrito de Riego (DR) 020, conocido como Morelia-Queréndaro. Con cada política obtenida se simuló el funcionamiento del sistema, usando el registro histórico de volúmenes de ingreso al sistema, para poder comparar con lo reportado por la Comisión Nacional del Agua (Conagua), y se eligieron aquellas que mantuvieron el balance entre cumplimiento de demandas y menor presencia de derrames o de déficits. Finalmente, con el fin de revisar el comportamiento del sistema en el largo plazo al utilizarse las políticas seleccionadas, se simularon series de volúmenes de ingreso mensual sintéticos con 100 años de registro, generados con el método de Svanidze. La comparación de los resultados de déficit y derrames a nivel mensual y anual de las simulaciones realizadas con la curva Z histórica, AG y GRG, indicaron que el AG tuvo un comportamiento aceptable tanto en el periodo histórico como a largo plazo, pues aunque los volúmenes derramados aumentaron, la magnitud en la que lo hicieron es menor a la magnitud en la que se redujo el déficit, y como la presa de Cointzio ha sido utilizada para suministro de agua a la planta potabilizadora de Vista Bella y para riego de 4 de los 5 módulos del Distrito de Riego 020 se eligió la regla de operación que controló mejor el evento de déficit. El algoritmo GRG reportó múltiples ventajas, entre ellas su facilidad de uso y la rapidez con la que encuentra resultados, siempre que no se indiquen demasiadas iteraciones; sin embargo, una desventaja del método es que no siempre converge a un óptimo global, ya que para distintos valores iniciales de la política Z el algoritmo dio diferentes valores óptimos. El AG, por su parte, converge a óptimos globales para cada simulación debido a que cada vez que se aplica el proceso se genera aleatoriamente una población y el resultado fue el mismo para unas condiciones de coeficientes de penalización dadas. Una limitante del método de los AG es el tiempo de cómputo empleado para la obtención de resultados.
The paper aims to identify industry and macrolevel factors that affect competitiveness of selected sectors upon the implementation of the JPEPA. Priority sectors identified by the Department of Trade ...and Industry, accounting for 82% of total Philippine exports to Japan in 2002, were included in the study. For Philippine industries to gain, market access issues on trade facilitation, nontariff barriers and recognition of standards come into play especially for the service and agricultural sectors. Internal industry-level factors deal with access to raw materials, lowering input costs through growth of support industries and infrastructure development, SME financing, exploiting economies of scale, firm-level flexibility in part due to utilization of new technologies, greater knowledge of the Japanese market and sustainability of human capital competitiveness through training. Social safety nets, if required, may be more effective if they focus on retraining and relocation of displaced workers. Cement, the import competing industry identified in the paper, will only face limited competition due to the constrained capacity and market of the Japanese cement importer. Industry-level competition or triangular relations with complementary counterparts in ASEAN countries to serve the Japanese market should be explored especially given that an ASEAN-Japan FTA is also being negotiated. The main macrolevel factor is on poor governance leading to political and economic uncertainty which adversely affect the attractiveness of the country as an investment site.
The paper aims to identify industry and macrolevel factors that affect competitiveness of selected sectors upon the implementation of the JPEPA. Priority sectors identified by the Department of Trade ...and Industry, accounting for 82% of total Philippine exports to Japan in 2002, were included in the study. For Philippine industries to gain, market access issues on trade facilitation, nontariff barriers and recognition of standards come into play especially for the service and agricultural sectors. Internal industry-level factors deal with access to raw materials, lowering input costs through growth of support industries and infrastructure development, SME financing, exploiting economies of scale, firm-level flexibility in part due to utilization of new technologies, greater knowledge of the Japanese market and sustainability of human capital competitiveness through training. Social safety nets, if required, may be more effective if they focus on retraining and relocation of displaced workers. Cement, the import competing industry identified in the paper, will only face limited competition due to the constrained capacity and market of the Japanese cement importer. Industry-level competition or triangular relations with complementary counterparts in ASEAN countries to serve the Japanese market should be explored especially given that an ASEAN-Japan FTA is also being negotiated. The main macrolevel factor is on poor governance leading to political and economic uncertainty which adversely affect the attractiveness of the country as an investment site.
ABSTRACT Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. ...Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life‐threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.
Significant consequences of COVID-19 within academic/professional life are, at the psychological level, related to worry, tension, stress; coping strategies and lifestyle changes. This study ...describes the process of design and validation of an inventory (QPIC), which aims to assess the psychological impact that a situation of confinement can produce among university students and teachers.
Design of the instrument and psychometric tests. A sample of 862 students and 229 professors affiliated to Spanish and Colombian universities was used. Data were collected in April 2020 with the request of the favourable Bioethics Committee IR/2020.
Six experts carried out the content validation. A confirmatory factor analysis of the theoretical dimensions proposed for the scales was performed and the internal consistency of each of the three initial scales was confirmed (0.866, 0.813 and 0.834).
A rigorous and reliable instrument is achieved, consisting of two final scales: (a) Worry, tension and stress scale (b) Coping scale, which helps to measure individual psychological effects in housebound situations. It is an instrument designed, constructed ad hoc to assess the impact of confinement and subjected to validation. The factor structure and reliability of the instrument are examined and good psychometric properties are obtained. The application of this inventory will make it possible to assess the impact on people's mental health during a period of confinement.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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