Variabilidad en el tamaño de ovocitos y fecundidad parcial de anchoveta (Engraulis ringens, Jenyns 1842) en dos áreas de desove de la costa de Chile

Utilising histological preparations of ovaries from Engraulis ringens females collected in two contrasting spawning habitats along the Chilean coast, we assess the variability in oocyte size and batch fecundity during the peak spawning seasons in three years. The effects of female size (length and weight), batch fecundity and mean sea surface temperature on oocyte size were also examined. Results showed larger oocytes and lower batch fecundity in females from the southern area. Oocyte volume differences persisted inter-annually and were not explained by differences in female sizes. Since ovary weight was similar between areas, the cost of producing larger oocytes in the south population seems to be a fecundity reduction. The latitudinal variations in oocyte number and size seem to be determined by the predominant environmental conditions in each habitat. Hence, female E. ringens seem to adapt their reproductive tactics by producing eggs sizes and quantities that favour survival of their offspring under the environmental conditions in which they are to develop.Utilizando preparaciones histológicas de ovarios de anchovetas (Engraulis ringens) colectadas en dos hábitats contrastantes a lo largo de la costa de Chile, se estudia la variabilidad en tamaño de ovocitos y fecundidad parcial en la estación de máximo desove durante tres años. Los efectos de tamaño de hembra (longitud total y peso total), fecundidad parcial y temperatura superficial del mar sobre el tamaño de los ovocitos, también fueron investigados. Los resultados mostraron ovocitos más grandes y menor fecundidad en hembras de la zona sur. Las diferencias en volumen de ovocitos persistieron inter-anualmente y no fueron explicadas por diferencias en el tamaño de las hembras. Dado que los pesos de los ovarios fueron similares entre zonas, el coste de producir ovocitos más grandes en la población del sur sería la reducción en la fecundidad. Las variaciones latitudinales en número y tamaño de ovocitos parecen ser determinadas por las condiciones ambientales predominantes en cada hábitat de desove. De este modo, las hembras de E. ringens adaptarían sus tácticas reproductivas produciendo tamaño y cantidades de huevos que favorezcan la supervivencia de sus descendientes a las condiciones ambientales en las que se desarrollarán

Simultaneous Grafting of Poly(Acrylic Acid) and Poly(Ethylene Glycol) onto Chitosan using Gamma Radiation: Polymer Networks for Removal of Textile Dyes

Chitosan is a bio-based polyelectrolyte with high potential for wastewater treatment. Chitosan can remove anionic dyes by adsorption but it has low performance in the removal of cationic dyes. In this work, we report the synthesis of chitosan-based graft-copolymers using gamma radiation. Acrylic acid and poly(ethylene glycol) were grafted successfully onto chitosan applying a radiation dose of 12 kGy at a dose rate of 8 kGyh-1. The grafted-copolymers have improved adsorptive properties for the removal of basic dyes reaching a maximum adsorption capacity higher than 300 mgg-1. The Lanmguir’s isotherm model described satisfactorily the interaction between the grafted copolymers and basic dyes. Freundlich’s isotherm model described the adsorption of anionic dye acid orange 52. The grafted copolymers removed successfully textile dyes from wastewater of the dyeing process. The best results were obtained in the removal of direct and basic dyes. Further, poly(ethylene glycol) grafted on the copolymer conferred better swelling behavior making easy the separation of the adsorbent after dye removal. The results showed that the adsorbent materials synthesized by radiochemical graftcopolymerization are more efficient than the beads, composite materials, and blends of chitosan

Graft-Copolymerization of Acrylate Monomers onto Chitosan Induced by Gamma Radiation: Amphiphilic Polymers and Their Behavior at The Air-Water Interface

Graft polymerization induced by ionizing radiation is a powerful tool in materials science to modifying the physical properties of polymers. Chitosan is a biocompatible, biodegradable, antibacterial, and highly hydrophilic polysaccharide. In this work, we report the obtaining of amphiphilic polymers through graft polymerization of acrylic monomers (methyl acrylate, t-butyl acrylate, and hexyl acrylate) onto chitosan. The polymerization reaction was carried out by simultaneous irradiation of monomers and chitosan using a gamma radiation source of 60Co. The formation of Langmuir films of amphiphilic polymers was studied at the air-water interface through surface pressure versus main molecular area isotherms (Π-A) and hysteresis cycles of compression and decompression. Finally, it was analyzed the transferring of Langmuir films towards solid substrates to obtaining Langmuir-Blodgett films with potential application as an antibacterial coating. The microstructure of the Langmuir-Blodgett films was characterized by AFM microscopy observing a regular topography with roughness ranging between 0.53 and 0.6 μm

Modelos Cognitivos de Ensino e Práticas Pedagógicas - Planificação de uma Aula de História segundo o Modelo Resolução de Problemas

Com este trabalho pretendo aprofundar a compreensão do paradigma cognitivo, a partir da sua relação com um dos modelos nele inspirado, o modelo Resolução de Problemas, aplicado a uma aula de História. Na primeira parte, começarei por clarificar os conceitos de pressuposto, paradigma emodelo, evidenciando a sua relação dialéctica. Seguidamente, procederei à caracterização do paradigma cognitivo, referindo os suportes em que assenta, as linhas estruturantes e os seus aspectos caracterizadores. Após uma abordagem dos modelos cognitivos de ensino, onde farei referência aos suportes conceptuais que caracterizam as suas principais práticas, destacarei o modelo Resolução de Problemas e descreverei a sua sintaxe. Numa segunda parte, irei enfrentar o desafio de aplicar o modelo em causa, a um cenário de uma aula de História do Ensino Secundário, em torno de um problema ligado à História Local

Characterization of grapevine (Vitis vinifera L.) cultivars from northern Portugal using RAPD and microsatellite markers

Twelve grapevine cultivars from northern Portugal were characterized with RAPD and microsatellites. Nine primers were used in the RAPD analysis; 8 of the varieties showed monotypic patterns. With the 6 microsatellite loci a total of 38 alleles was obtained. Relationships among the studied varieties were observed. Both types of molecular markers have proved useful for identification. Existence of synonymies is discussed.

Sludge volume index and suspended solids estimation of mature aerobic granular sludge by quantitative image analysis and chemometric tools

Aerobic granular sludge (AGS) is considered a promising technology for wastewater treatment. Furthermore, it is recognized that the stability of the process is related to the balanced growth of the suspended (floccular) and granular fractions. Therefore, the development of adequate techniques to monitor this balance is of interest. In this work the sludge volume index (SVI), volatile suspended solids (VSS) and total suspended solids (TSS) of mature AGS were successfully predicted with multilinear regression (MLR) models using data obtained from quantitative image analysis (QIA) of both fractions (suspended and granular). Relevant predictions were obtained for the SVI (R2 of 0.975), granules TSS (R2 of 0.985), flocs TSS (R2 of 0.971), granules VSS (R2 of 0.984) and flocs VSS (R2 of 0.986). The estimation of the granular fraction ratio from the predicted TSS and VSS was also successful (R2 of 0.985). The predictions help to avoid instability episodes of the AGS system, such as changes in biomass morphology, structure and settling properties.The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte and the project AGeNT – PTDC/BTA-BTA/31264/2017 (POCI-01-0145-FEDER031264). We would also like to thank the scientific collaboration under the FCT project UID/Multi/50016/2019. Cristiano Leal is recipient of a fellowship supported by a doctoral advanced training (call NORTE-692015-15) funded by the European Social Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. A. Val del Rio is supported by Xunta de Galicia (ED418B 2017/075) and program Iacobus (2017/2018).info:eu-repo/semantics/publishedVersio

Promoção do consumo de frutas, legumes e verduras em escolas: diagnóstico inicial.

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Assessment of an aerobic granular sludge system in the presence of pharmaceutically active compounds by quantitative image analysis and chemometric techniques

In this study, a sequencing batch reactor (SBR) with aerobic granular sludge (AGS) was operated with synthetic wastewater containing environmental relevant concentrations of 17-estradiol (E2), 17-ethinylestradiol (EE2) and sulfamethoxazole (SMX). Despite the presence of the studied PhAC, the granular fraction clearly predominated (TSSgran/TSS ranging from 0.82 to 0.98) throughout the monitoring period, presenting aggregates with high organic fraction (VSS/TSS above 0.83) and good settling characteristics (SVI5 ranging from 15 to 39 mL/gTSS). A principal component analysis (PCA) with quantitative image analysis (QIA) based data allowed to distinguish the different operational periods, namely with mature granules (CONT), and the E2, EE2, and SMX feeding periods. It further revealed a positive relationship between the biomass density, sludge settling ability, overall and granular biomass contents, granulation properties, granular biomass fraction and large granules fraction and size. Moreover, a discriminant analysis (DA) allowed to successfully discriminate not only the different operational periods, mainly by using the floccular apparent density, granular stratification and contents data, but also the PhAC presence in samples. The filamentous bacteria contents, sludge settling properties, settling properties stability and granular stratification, structure and contents parameters were found to be crucial for that purpose.The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project AGeNT - PTDC/BTA-BTA/31264/2017 (POCI-01-0145-FEDER-031264). We would also like to thank the scientific collaboration under the FCT project UIDB/50016/2020. The authors wish to thank the company Águas do Tejo Atlântico, S.A. for supplying the granules. Cristiano Leal is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. A. Val del Rio is supported by Xunta de Galicia (ED418B 2017/075) and program Iacobus (2018/2019). Daniela P. Mesquita and Cristina Quintelas thanks FCT for funding through program DL 57/2016 – Norma transitória. Cristiano Leal also thank to Renê Benevides for all the support during the experimental activities.info:eu-repo/semantics/publishedVersio