Definição dos mecanismos de polaridade celular durante a citocinese

Dissertação de Mestrado, Oncobiologia – Mecanismos Moleculares do Cancro, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2016A conclusão do processo da citocinese é o evento final da divisão celular. De forma a garantir a estabilidade genética dos organismos a citocinese não pode ocorrer antes que os cromossomas sejam fielmente segregados. Falhas neste processo são uma importante causa de instabilidade genética, ou seja, quando desregulado este processo poderá conduzir a anormalidades em organismos multicelulares, como o cancro. Durante a citocinese há a constrição do anel de actmiosina, seguindo-se a formação da ponte intercelular, na qual no meio se encontra o midbody. Este é constituído por várias proteínas que são necessárias para o início da abscisão (ex: hsMOB4A e hsMOB4B, γ-tubulina, centriolina, etc). Trabalhos anteriores do nosso grupo mostraram que as proteínas hsMOB4A e hsMOB4B são essenciais para a execução da abscisão e que quando depletadas aumentam a mobilidade celular. Muitas proteínas que se localizam no midbody, encontram-se também noutras estruturas (ex: centrossomas). Esta diversidade de localizações e funções, torna a dissecação do mecanismo citocinético complicado, sendo de difícil análise a função de cada proteína associada a uma localização celular, apenas através da técnica de RNAi. Uma técnica que permite a inactivação temporal e local é a Chromophore Assited Laser Inactivation (CALI). A base desta técnica é a inactivação local da proteína de interesse devido a geração de espécies reactivas de oxigénio (ROS) após a iluminação com um laser. Neste trabalho, foram desenvolvidas ferramentas para a realização de ensaios de CALI. Criaram-se linhas estáveis a expressar β-tubulina-SNAP-tag e γ-tubulina-SNAP-tag para otimização dos ensaios de CALI e, também, para analisar qual a função destas proteínas na abscisão. Para ensaios de CALI em conjunto com a técnica de RNAi (para deplecção da hsMOB4A e hsMOB4B endógenas) nas proteínas hsMOB4A e hsMOB4B, foram concebidos e caracterizados clones hsMOB4A e hsMOB4B resistentes ao RNAi, com o objectivo da geração de duas linhas estáveis, SNAP-tag-hsMOB4A e SNAP-tag-hsMOB4B resistentes ao RNAi, de modo a perceber qual a localização necessária destas proteínas para que ocorra o processo de abscisão. Todas estas ferramentas desenvolvidas ao longo deste trabalho, permitirão realizar ensaios de CALI nas proteínas de interesse e compreender qual a sua localização para que ocorra o evento final da citocinese, a abscisão.The completion of cytokinesis process is the final event of cell division. In order to guarantee the genetic stability of organisms cytokinesis cannot occur before the chromosomes are properly segregated. Failures in this process are an important cause of genetic instability, that is, when dysregulated this may lead to abnormalities in multicellular organisms, such as câncer. During cytokinesis there is a constriction actmiosin ring, following the formation of the intercellular bridge, in which in the middle is the midbody. This is composed of various proteins, these proteins which are necessary for the start of the constriction (eg hsMOB4A and hsMOB4B, γ-tubulin, centriolin etc.). Previous work from our group showed that the hsMOB4A and hsMOB4B proteins are essential for the implementation of abscission and when depleted increase cell motility. Many proteins that are located in the midbody, are also found on other structures (eg centrosomes). This diversity of locations and functions turns the dissect of cytokinetic mechanism difficult, and is also difficult to analyze the function that is associated with the location of each protein trough the RNAi technique. The technique that allows temporal inactivation and locally is the Chromophore-Assisted Laser Inactivation (CALI). The basis of this technique is the local inactivation of the protein of interest due to generation of reactive oxygen species (ROS) after illumination with a laser. In this work, tools have been developed for conducting assays CALI. Stable lines were created, expressing β-tubulin-SNAP-tag and γ-tubulin-SNAP-tag for optimization of CALI tests and also to analyze what the function of these proteins in abscission. For CALI tests together with the RNAi technique (for depletion of endogenous and hsMOB4A hsMOB4B) in the hsMOB4A and the hsMOB4B proteins, the hsMOB4A and hsMOB4B RNAi-resistant clones were designed and characterized, with the aim of generating two stable lines, SNAP- hsMOB4A and SNAP-tag-tag-resistant hsMOB4B RNAi, in order to understand what is localization of this protein to occur the abscission process. All of these tools developed during this work, will allow to perform CALI tests in proteins of interest and, understand what is the location that the signal has to come to occur the final event of cytokinesis, the abscission

Quality assessment of chilled and frozen fish: mini review

Fish is a very perishable food and therefore several storage strategies need to be employed to increase its shelf-life, guaranteeing its safety and quality from catch to consumption. Despite the advances in modern fish storage technologies, chilling and freezing are still the most common preservation methods used onboard. The present review aims to summarize strategies to increase the shelf-life of fresh (chilled) and frozen fish, as whole, gutted, or fillet, involving the assessment of different traditional cooling and freezing conditions of di erent fish species caught in different locations. Although there are other factors that influence the fish shelf-life, such as the fish species and the stress suffered during catch, storage time and temperature and the amount of ice are some of the most important. In addition, the way that fish is stored (whole, fillet, or gutted) also contributes to the final quality of the product. In most studies, whole chilled and frozen fish present longer shelf-life than those preserved as gutted and filleted. However, it should be noted that other factors related to the organism, capture method, and transport to the preparation/processing industry should be considered for shelf-life extension.info:eu-repo/semantics/publishedVersio

Application of microalgae as natural colorant for pastry and confectionary products

Modern consumers demand the replacement of synthetic colorants with natural alternatives. Microalgae can serve as an alternative source for these colorants since they hold significant amounts of pigments. This study aimed to evaluate the potential of using microalgae biomass and extracts as natural colorants for pastry and confectionary products. The application of different biomass and levels of Chlorella vulgaris (White, Honey, and a mixture of both) was evaluated in brioche-type breads as egg substitute to confer the typical yellow coloration to the product. A mixture of 1% Chlorella vulgaris (White: Honey [1:1]) showed potential as egg substitute, having minimal impact on the physical–chemical, microbiological, nutritional, and sensory characteristics of the products. Hydroalcoholic Tetraselmis chuii extracts were applied in fondant at a concentration of 0.05%, providing a green coloration with minimal impact on the quality of the product. This study supported the potential of using microalgae, biomass, and extracts, as alternative natural colorants in pastry and confectionary products.info:eu-repo/semantics/publishedVersio

Reproduction of the Blue Jack Mackerel, Trachurus picturatus, in Western Portugal: Microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns

This study was partially supported by the European Maritime and Fisheries Fund MAR2020 project “VALOREJET: Valorização de espécies rejeitadas e de baixo valor comercial”, MAR- 01.03.01-FEAMP-0003 and by Fundação para a Ciência e Tecnologia through research contracts attributed to Vera Sequeira (CEECIND/02705/2017) and Ana Rita Vieira (CEECIND/01528/2017) and strategic project UIBD/04292/2020.Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population off the west coast of Portugal. The proportion and length range of males and females were similar. Only three of the specimens collected were categorized as immature, indicating that the fish caught in the fishery are primarily mature. The spawning season lasted from late January until the end of March, with gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low number of females showing direct evidence of imminent or recent spawning suggests a low number of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning events. This study highlights the importance of accounting for skipped spawning events and ovary abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio

The Lockdown Impact on the Relations between Portuguese Parents and Their 1- to 3-Year-Old Children during the COVID-19 Pandemic

Funding Information: In Portugal, during the first lockdown, with few exceptions, families with children under 12 years old were given a choice. One parent could suspend his/her professional activity temporarily and receive financial support from the National Social Security System []. Most families, especially those with little children, chose this option. Publisher Copyright: © 2022 by the authors.Many countries have applied mandatory confinement measures in response to the COVID-19 pandemic, such as school and kindergarten closures, which confined families to their homes. The study concerns the impacts of the first COVID-19 lockdown on the relationships between Portuguese parents and their children, in a non-clinical population composed of fathers and mothers of children between the ages of 12 months and 3 years and 364 days. An online questionnaire (set by the research team) and the Parenting Daily Hassles Scale (PDHS) concerning the confinement period were applied between 17 June and 29 July 2020. To assess the impacts of the lockdown, outcomes regarding the impacts perceived by the parents, the potential regression in the development of children, and the willingness to promote changes in family routines in the future, were considered. Of the total sample (n = 1885), 95.4% of the parents (n = 1798) said that, after confinement, the relationship with their children had improved or remained similar to the pre-confinement period; 97.3% (n = 1835) noticed positive changes in the development of their children, and 63.7% (n = 1200) noted that the relationships with their children during the confinement period would lead to some changes in family routines in the future. Multivariate regression analyses showed that most of the sociodemographic variables chosen were not associated with the outcomes. However, significant levels of pressure over parenting and parental overload (reported by high scores in the PDHS intensity and frequency scales), challenging behaviors of the children, and the impacts they had on parental tasks had negative influences on the studied outcomes. On the contrary, the number of adults living with their children, the perceptions regarding the development of their children, and sharing new experiences with them were significant factors for positively-perceived impacts on the relationships between them or in the desire to bring about changes in family routines in the future. The impacts of the lockdown on the relationships between parents and children aged between 1 and 3 years old were more dependent on relational aspects and on the parents’ sense of competence in exercising parental functions. We conclude that, despite the increased demands imposed by the lockdown, nearly all of the parents evaluated the quality of the relationship with their children as positive after this period.publishersversionpublishe

Seasonal sensory evaluation of low commercial value or unexploited fish species from the Portuguese coast

Overfishing is increasing over time, and according to FAO (Food and Agriculture Organization), about one third of the world’s fish stocks are now overfished. Thus, diversifying the target species is essential for fisheries sustainability contributing to improve resource-effcient processes. Non-target species can be valuable resources for the development of new food products. However, those species are scarcely studied, and it is of high importance to trace their seasonal sensory profile as a first step towards their valorisation. Therefore, in this study, seasonal influence on sensory properties of five low commercial value or unexploited fish species, namely Trachurus picturatus (blue jack mackerel), Spondyliosoma cantharus (black seabream), Trigla lyra (piper gurnard), Serranus cabrilla (comber) and Capros aper (boarfish), was assessed in order to identify the most favourable season for catching each species. Fish samples were assessed by a panel of 16 semi-trained assessors for sensory attributes previously identified. The evaluation takes place every 2 months. Statistical differences were reported between attributes and seasons for all species, except for T. lyra, which did not present any di erence in its sensory attributes throughout the year.info:eu-repo/semantics/publishedVersio

Aumentar el conocimiento biológico para una mejor gestión de las especies de captura incidental: edad, crecimiento y mortalidad de garneo y arete (Teleostei: Triglidae)

Gurnards are a valuable by-catch of mixed demersal fisheries and are commercially important in European waters, but they are often discarded, reported under “mixed gurnards” and with incomplete biological information by species. In the present work, a total of 558 piper gurnard specimens of between 10.9 and 44.4 cm (1 to 11 years) and 425 red gurnard specimens of between 10.2 and 42.1 cm (0 to 9 years) from the northeast Atlantic (Portuguese) coast were used to study age and growth. The von Bertalanffy growth parameters for piper gurnard were estimated through the combination of whole-otolith readings and back-calculation (L∞=44.7 cm, k=0.16 yr–1 and t0=–2.781 yr). For red gurnard the same growth parameters were estimated using whole-otolith readings (L∞=40.2 cm, k=0.28 yr–1 and t0=–1.074 yr). The results indicate that the red gurnard reaches a smaller length, although it grows faster than the piper gurnard. Natural, instantaneous and fishing mortalities were estimated as well as the exploitation rate for both species. For the Portuguese coast, the red gurnard showed a higher fishing mortality and exploitation rate than the piper gurnard, raising concerns about its sustainable management.Los rubios son una captura incidental valiosa de las pesquerías demersales mixtas y comercialmente importantes en las aguas europeas, pero a menudo se descartan, se informan como “rubios mixtos” y con información biológica incompleta por especie. En el presente trabajo se han recogido un total de 558 ejemplares de ganeo, de entre 10,9 y 44,4 cm (1 a 11 años), y 425 individuos de arete, de entre 10,2 y 42,1 cm (0 a 9 años) procedentes del Atlántico nororiental (costa portuguesa) se utilizaron para estudiar la edad y el crecimiento. Los parámetros de crecimiento de von Bertalanffy para ganeo se estimaron mediante la combinación de lecturas de otolitos enteros y retrocálculo (L∞=44,7 cm, k=0,16 año–1 y t0=-2,781 años). Para el arete se estimaron los mismos parámetros de crecimiento usando lecturas de otolito entero (L∞=40.2 cm, k=0.28 año–1 y t0=–1.074 año). Los resultados indican que el arete alcanza una talla menor, aunque crece más rápido que el ganeo. Se estimó la mortalidad natural, instantánea y por pesca, así como la tasa de explotación para ambas especies. Para la costa portuguesa, el arete presentó una mortalidad por pesca y una tasa de explotación más altas que el ganeo, lo que generó preocupaciones sobre su gestión sostenible

Modelling Fish Growth with Imperfect Data: The Case of Trachurus picturatus

Growth modelling is essential to inform fisheries management but is often hampered by sampling biases and imperfect data. Additional methods such as interpolating data through back-calculation may be used to account for sampling bias but are often complex and time-consuming. Here, we present an approach to improve plausibility in growth estimates when small individuals are under-sampled, based on Bayesian fitting growth models using Markov Chain Monte Carlo (MCMC) with informative priors on growth parameters. Focusing on the blue jack mackerel, Trachurus picturatus, which is an important commercial fish in the southern northeast Atlantic, this Bayesian approach was evaluated in relation to standard growth model fitting methods, using both direct readings and back-calculation data. Matched growth parameter estimates were obtained with the von Bertalanffy growth function applied to back-calculated length at age and the Bayesian fitting, using MCMC to direct age readings, with both outperforming all other methods assessed. These results indicate that Bayesian inference may be a powerful addition in growth modelling using imperfect data and should be considered further in age and growth studies, provided relevant biological information can be gathered and included in the analyses.info:eu-repo/semantics/publishedVersio

Adding value to bycatch fish species captured in the Portuguese coast—development of new food products

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.info:eu-repo/semantics/publishedVersio

Characterization of Phthalate Exposure among Pregnant Women Assessed by Repeat Air and Urine Samples

Background: Although urinary concentrations of phthalate metabolites are frequently used as biomarkers in epidemiologic studies, variability during pregnancy has not been characterized. Methods: We measured phthalate metabolite concentrations in spot urine samples collected from 246 pregnant Dominican and African-American women. Twenty-eight women had repeat urine samples collected over a 6-week period. We also analyzed 48-hr personal air samples (n = 96 women) and repeated indoor air samples (n = 32 homes) for five phthalate diesters. Mixed-effects models were fit to evaluate reproducibility via intraclass correlation coefficients (ICC). We evaluated the sensitivity and specificity of using a single specimen versus repeat samples to classify a woman’s exposure in the low or high category. Results: Phthalates were detected in 85–100% of air and urine samples. ICCs for the unadjusted urinary metabolite concentrations ranged from 0.30 for mono-ethyl phthalate to 0.66 for monobenzyl phthalate. For indoor air, ICCs ranged from 0.48 [di-2-ethylhexyl phthalate (DEHP)] to 0.83 [butylbenzyl phthalate (BBzP)]. Air levels of phthalate diesters correlated with their respective urinary metabolite concentrations for BBzP (r = 0.71), di-isobutyl phthalate (r = 0.44), and diethyl phthalate (DEP; r = 0.39). In women sampled late in pregnancy, specific gravity appeared to be more effective than creatinine in adjusting for urine dilution. Conclusions: Urinary concentrations of DEP and DEHP metabolites in pregnant women showed lower reproducibility than metabolites for di-n-butyl phthalate and BBzP. A single indoor air sample may be sufficient to characterize phthalate exposure in the home, whereas urinary phthalate biomarkers should be sampled longitudinally during pregnancy to minimize exposure misclassification