Dietary biodiesel-derived crude glycerol in gilthead seabream juveniles (Sparus aurata): effects on growth performance and metabolism

In the European Union the turn towards renewable energy sources has increased the production of biodiesel from rapeseed oil, leaving glycerol (also known as glycerin) as a valuable by-product. For every litre of biodiesel produced, approximately 79 g of crude glycerol are generated. As the biodiesel production grows, the quantity of crude glycerol generated will be considerable and its utilization will become an urgent topic. One possibility is the use of crude glycerol on animal feeds. Glycerol has been evaluated as a dietary energy source for several farm animals, including fish. A study was undertaken to assess the effect of dietary biodiesel-derived glycerol (from rapeseed oil) on the overall growth performance, digestive capacity and metabolic nutrient utilization in juvenile gilthead seabream fed a low fishmeal level diet. Two practical diets were formulated to be isonitrogenous (crude protein, 45.4% DM), isolipidic (18.5% DM) and isoenergetic (gross energy, 21.3 kJ/g DM). The control diet (CTRL) was formulated with intermediate levels of marine-derived proteins (19%). In the same basal formulation, 5% glycerol (GLY) was incorporated at the expenses of wheat. Each dietary treatment was tested in triplicate tanks over 63 days, with 20 gilthead seabream (Sparus aurata), with a mean initial body weight (IBW) of 27.9 0.12 g. At the end of the trial, fish fed the CTRL diet reached a final body weight of 84.3 2.2 g (more than 3-fold increase of initial body weight). Fish fed the GLY diet showed a significantly higher (P<0.05) growth, expressed in terms of final body weight and specific growth rate. Voluntary feed intake was similar between the two treatments, but both feed efficiency and protein efficiency ratio were significantly improved (P0.05) on the apparent digestibility of protein. In comparison to the control treatment, dietary glycerol significantly improved (P<0.05) protein and fat retention. Activities of digestive enzymes were significantly affected by the various dietary treatments. Fish fed the GLY diet showed an enhanced activity of alkaline phosphatase (ALP) and pepsin, while activities of lipase and leucine-alanine peptidase (LAP) were little affected by dietary glycerol. Fish show the ability to use crude glycerol as a dietary energy substrate.Na União Europeia, tem-se verificado uma procura crescente de novas fontes de energia renováveis, o que tem conduzido a um aumento da produção de biodiesel a partir de óleo de colza, originando o glicerol (também conhecido como glicerina) como um valioso subproduto. Por cada litro de biodiesel produzido, são geradas aproximadamente 79 g de glicerol bruto. À medida que a produção de biodiesel aumenta geram-se quantidades consideráveis de glicerol tornando-se urgente encontrar soluções adequadas à utilização deste excedente. Uma alternativa possível é a utilização de glicerol bruto na formulação de rações para animais. O glicerol tem sido estudado como fonte de energia nas dietas de diferentes animais, incluindo peixes. O presente trabalho descreve um estudo efectuado para avaliar o efeito da incorporação de glicerol bruto derivado da produção de biodiesel (a partir de óleo de colza) em dietas, com baixo teor em farinha de peixe, para juvenis de dourada (Sparus aurata). Os principais parâmetros avaliados foram o desempenho global de crescimento, a capacidade digestiva e a utilização metabólica de nutrientes. Duas dietas práticas foram formuladas para serem isoproteicas (proteína bruta, 45,4% de MS), isolipídicas (18,5% de MS) e isoenergéticas (energia bruta, 21,3 kJ / g MS). A dieta de controlo (CTRL) foi produzida com níveis intermédios de derivados de proteínas marinhas (19%). A partir da mesma formulação base, 5% de glicerol foi incorporado em detrimento do trigo obtendo-se a dieta glicerol (GLY). Os tratamentos foram testados em triplicado durante 63 dias, em grupos de 20 douradas com um peso médio inicial (PI) de 27,9 0,12 g. No final do ensaio, os peixes alimentados com a dieta CTRL atingiram um peso final (PF) de 84,3 2,2 g, triplicando o seu peso inicial. Os peixes alimentados com a dieta GLY mostraram um crescimento significativamente superior (P <0,05) em termos de peso final e taxa de crescimento específico. A ingestão de alimento foi similar entre os dois tratamentos, mas quer a eficiência alimentar quer o coeficiente de eficácia proteica melhoraram significativamente (P <0,05) nos peixes alimentados com a dieta GLY. A incorporação de glicerol na dieta não teve efeito (P> 0,05) sobre a digestibilidade aparente da proteína. Em comparação com o tratamento de controlo, o glicerol melhorou significativamente (P <0,05) a retenção de proteína e de gordura. A atividade dos enzimas digestivos foi significativamente alterada pelos diferentes tratamentos. Peixes alimentados com a dieta GLY mostraram um aumento da atividade da fosfatase alcalina (ALP) e da pepsina, enquanto a atividade da lipase e da leucina-alanina peptidase (LAP) foram pouco influenciadas pelo glicerol na dieta. A dourada demonstrou uma boa capacidade de utilizar glicerol bruto como uma fonte energética fornecida pela dieta

Efeitos da neuregulina-1 nas alterações metabólicas induzidas pela hipertensão arterial pulmonar

Pulmonary arterial hypertension (PAH) is a chronic rare disease, characterized by increased pulmonary vascular resistance (PVR) with progressive overload and remodelling of the right ventricle (RV), that eventually leads to right ventricular heart failure (RVHF). These derangements arise from a metabolic switch from glucose oxidation towards glycolysis, the Warburg effect, affecting glucose metabolism at the systemic level. The neuregulin-1 (NRG1), a protein that has been shown to play beneficial effects on PAH and RV hypertrophy, has also been associated with the regulation of glucose metabolism given its role in modulating the expression of glucose transporters (GLUTs). In this study we aimed to evaluate the effect of rhNRG1 chronic treatment on glycolysis pathway genes expression in the RV and skeletal muscle in a monocrotaline (MCT)-induced PAH animal model and in chronic hypoxia/Sugen5416 model that also reproduces key pathophysiological features from human PAH. We have found that RV GLUT1 and GLUT4 mRNA expression is altered in PAH and was similar between the MCT and hypoxia/Sugen5416 animal models, being this related with the development of RV hypertrophy (RVH). However, the treatment with rhNRG1 only attenuated GLUTs expression toward normal values in MCT-induced PAH model. The expression of GLUT1 and GLUT4 is correlated with cardiac markers of disease, while the glycolytic pathway genes are correlated with the morphophysiological changes resulting from the development of PAH in MCT model. From the analysis of some glycolytic pathway genes, we conclude that beyond GLUTs, several genes are related, not only with the Warburg effect, but also with the disease progression. We also found that the treatment with rhNRG1 attenuated the changes in some glycolytic pathway genes, resulting in an improvement of glucose metabolism. The glucose tolerance evaluation revealed that the animals with PAH from both models are insulin resistant and that the treatment with rhNRG1 regulated systemic glucose concentration in both animal models. In conclusion, the therapeutic effects of NRG1 in experimental PAH may be due, in part, to the regulation of metabolic changes associated with PAH progression and RV dysfunction, which were reflected in the reversion of the ventricular phenotype of the disease.A hipertensão arterial pulmonar (HAP) é uma doença crónica rara, caracterizada pelo aumento da resistência vascular pulmonar (RVP) com sobrecarga progressiva e remodelagem do ventrículo direito (VD), o que pode levar à insuficiência cardíaca do ventrículo direito (ICVD). Estas perturbações surgem na sequência de uma alteração metabólica na oxidação da glicose, um processo designado por efeito de Warburg, que afeta o metabolismo da glicose a nível sistémico. A neuregulina-1 (NRG1), uma proteína que demonstrou ter efeitos benéficos na hipertrofia do VD causada pela HAP, está também associada à regulação do metabolismo da glicose dado seu papel na modulação da expressão dos transportadores de glicose (GLUTs). Neste estudo, o nosso objetivo tinha por base a avaliação do efeito do tratamento crónico com rhNRG1 na expressão de genes da via da glicólise no VD e em músculo esquelético num modelo animal de HAP induzida por monocrotalina (MCT) e num um modelo crónico de hipoxia/Sugen5416, que reproduz algumas das principais características fisiopatológicas da HAP humana. Verificamos que a expressão de mRNA do GLUT1 e do GLUT4 no VD está alterada na HAP e que se demonstrou semelhante entre os modelos animais MCT e hipoxia/Sugen5416, estando relacionada com o desenvolvimento de hipertrofia do VD (HVD). No entanto, o tratamento com rhNRG1 apenas atenuou a expressão dos GLUTs para valores próximos aos normais no modelo de HAP induzida por MCT. Enquanto que a expressão do GLUT1 e do GLUT4 está correlacionada com marcadores cardíacos da doença, os genes da via glicolítica demonstraram estar correlacionados com as alterações morfofisiológicas resultantes do desenvolvimento da HAP no modelo MCT. A partir da análise de alguns genes da via glicolítica, concluímos que, para além dos GLUTs, alguns genes estão relacionados, não só com o efeito de Warburg, mas também com a progressão da doença. Verificamos também que o tratamento com rhNRG1 atenuou as alterações de expressão em alguns genes da via glicolítica, resultando numa melhoria do metabolismo da glicose. A avaliação da tolerância à glicose revelou que os animais com HAP de ambos os modelos são resistentes à insulina e que o tratamento com rhNRG1 regulou a concentração sistémica de glicose em ambos os modelos animais. Em conclusão, os efeitos terapêuticos da NRG1 na HAP experimental podem dever-se, em parte, à regulação das alterações metabólicas que estão associadas à progressão da HAP e à disfunção do VD, e que se refletiram na reversão do fenótipo ventricular da doença.Mestrado em Biologia Molecular e Celula

B cells at the crossroad of immune responses : insights from primary B-cell immunodeficiencies

Tese de doutoramento, Ciências Biomédicas (Imunologia), Universidade de Lisboa, Faculdade de Medicina, 2012B lymphocytes are important players in adaptive immunity and the main targets of current vaccination strategies, with the interaction between B and T cells being fundamental to generate long-term immunity. B cells also play a key role in linking innate and adaptive immunity by expressing receptors that recognize both specific antigens and microbial patterns. The general aim of this work was to investigate the interplay between B cells and other components of the immune system through the study of B-cell immunodeficiencies, namely Common Variable Immunodeficiency (CVID), characterized by impaired antibody production due to defective mature B-cell differentiation, and Congenital Agammaglobulinemia, where early Bcell development is abrogated, commonly resulting in the absence of peripheral B cells. We found BAFF-R expression to be reduced in CVID, particularly in patients with low memory B cells, and associated with high serum levels of BAFF, while TACI expression was significantly increased. BAFF induced BAFF-R down-regulation in vitro, both in healthy individuals and CVID patients. However, the degree of modulation in CVID was impaired, suggesting that these dynamics are affected, with a possible impact in B-cell homeostasis. We also observed that CVID was associated with monocyte activation, irrespective of LPS levels, but in direct association with T-cell activation and B-cell imbalances. To explore the mechanisms underlying chronic immune activation, we studied the role of IL-17, a major pro-inflammatory cytokine implicated in autoimmunity and inflammatory conditions, frequently found in CVID. However, no increase in TH17 cells was found and their frequency was inversely correlated with markers of germinal centre impairment. TH17 cells were severely reduced in Congenital Agammaglobulinemia and directly associated with switchedmemory B cells in healthy subjects. Our data support a link between B-cell differentiation and TH17 homeostasis, with implications for the understanding of the pathogenesis of inflammatory/autoimmune diseases and the physiology of B-cell depleting therapies.Linfócitos B têm um papel preponderante na imunidade adaptativa e são os principais alvos das estratégias de vacinação, sendo a interacção entre linfócitos B e T fundamental para desenvolver imunidade a longo prazo. Linfócitos B têm também um papel importante no estabelecimento da ponte entre imunidade inata e adaptativa. O objectivo principal deste trabalho foi investigar o diálogo entre linfócitos B e outros elementos do sistema imunitário, através do estudo da Imunodeficiência Comum Variável (IDCV), caracterizada por produção deficiente de anticorpos resultante de defeitos na maturação de linfócitos B, e da Agamaglobulinémia Congénita, em que ocorre um bloqueio precoce no desenvolvimento de linfócitos B, resultando frequentemente na sua ausência em circulação. A expressão de BAFF-R encontrou-se diminuída na IDCV, particularmente em doentes que possuíam uma frequência baixa de linfócitos B de memória, associada a níveis séricos de BAFF elevados. BAFF induziu diminuição de expressão de BAFF-R in vitro, no entanto de forma alterada na IDCV, sugerindo que esta dinâmica está afectada, com possível impacto na homeostasia de linfócitos B. A IDCV associou-se com activação monocitária, não relacionada com níveis de LPS, mas com activaçãode de linfócitos T e alterações de linfócitos B. Para explorar os mecanismos subjacentes à activação imunitária crónica, estudámos o papel da IL-17, citocina pró-inflamatória envolvida em autoimunidade e manifestações inflamatórias, as quais são frequentemente associadas a IDCV. No entanto, não houve aumento de linfócitos TH17 e a sua frequência associou-se inversamente com evidências de defeitos de centros germinativos. Linfócitos TH17 estavam reduzidos na Agamaglobulinémia Congénita, e em indivíduos saudáveis encontravam-se associados com a frequência de linfócitos B de memória com switch. Estes resultados mostram que a homeostasia de linfócitos TH17 se associa à maturação de linfócitos B, com implicações para a compreensão da patogénese de doenças inflamatórias/autoimunes e da fisiologia de terapêuticas depletivas de linfócitos B.Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/46542/2008); POCI 2010 e o FS

Nutritional risk and survival in cancer patients undergoing percutaneous Endoscopic Gastrostomy in the Instituto Português de Oncologia do Porto Francisco Gentil, EPE.

[resumo][abstract

The future is now: the impact of digital transformation on business models and corporate communication

We are living in a world of rapid evolving technologies that are fusing the physical, digital and biological worlds and impacting all disciplines, economies and industries, and even challenging ideas about what it means to be human (WEF, n.d.). Amidst the so-called 4th industrial revolution, every company’s success is now more than ever dependent on its capacity to adjust to this new era and make smart investments in the future. The aim of the present work is to demonstrate how Digital Transformation (DT) plays a key role in that process, shaping today’s business models, customer relationship and even the way we communicate. To accomplish that goal, examples of DT from Amazon, Santander and Emel shall be explored in order to illustrate this trend and showcase how these organizations, in particular, are progressing along the digital maturity path.Not Publishe

Empirically supported interventions in psychology: contributions of Research Domain Criteria

Empirically supported interventions in psychological disorders should provide (1) evidence supporting the underlying psychological mechanisms of psychopathology to target in the intervention and (2) evidence supporting the efficacy of the intervention. However, research has been dedicated in a greater extent to efficacy than to the acquisition of empirical support for the theoretical basis of therapies. Research Domain Criteria (RDoC) emerges as a new framework to provide empirically based theories about psychological mechanisms that may be targeted in intervention and tested for its efficacy. The current review aims to demonstrate the possible applications of RDoC to design empirically supported interventions for psychological disorders. Two RDoC-inspired interventions are reviewed, and the RDoC framework is broadly explored in terms of its contributions and limitations. From preliminary evidence, RDoC offers many avenues for improving evidence-based interventions in psyinfo:eu-repo/semantics/publishedVersio

A comprehensive review on photoacoustic-based devices for biomedical applications

The photoacoustic effect is an emerging technology that has sparked significant interest in the research field since an acoustic wave can be produced simply by the incidence of light on a material or tissue. This phenomenon has been extensively investigated, not only to perform photoacoustic imaging but also to develop highly miniaturized ultrasound probes that can provide biologically meaningful information. Therefore, this review aims to outline the materials and their fabrication process that can be employed as photoacoustic targets, both biological and non-biological, and report the main components’ features to achieve a certain performance. When designing a device, it is of utmost importance to model it at an early stage for a deeper understanding and to ease the optimization process. As such, throughout this article, the different methods already implemented to model the photoacoustic effect are introduced, as well as the advantages and drawbacks inherent in each approach. However, some remaining challenges are still faced when developing such a system regarding its fabrication, modeling, and characterization, which are also discussed.This work was supported by Fundação para a Ciência e Tecnologia national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020

Neural circuit basis of visuo-spatial working memory precision: A computational and behavioral study

The amount of information that can be retained in working memory (WM) is limited. Limitations of WM capacity have been the subject of intense research, especially in trying to specify algorithmic models for WM. Comparatively, neural circuit perspectives have barely been used to test WM limitations in behavioral experiments. Here we used a neuronal microcircuit model for visuo-spatial WM (vsWM) to investigate memory of several items. The model assumes that there is a topographic organization of the circuit responsible for spatial memory retention. This assumption leads to specific predictions, which we tested in behavioral experiments. According to the model, nearby locations should be recalled with a bias, as if the two memory traces showed attraction or repulsion during the delay period depending on distance. Another prediction is that the previously reported loss of memory precision for an increasing number of memory items (memory load) should vanish when the distances between items are controlled for. Both predictions were confirmed experimentally. Taken together, our findings provide support for a topographic neural circuit organization of vsWM, they suggest that interference between similar memories underlies some WM limitations, and they put forward a circuit-based explanation that reconciles previous conflicting results on the dependence of WM precision with load. Copyright © 2015 the American Physiological Society

Co-limitation of phytoplankton by N and P in a shallow coastal lagoon (Ria Formosa): implications for eutrophication evaluation

The Ria Formosa coastal lagoon is a highly productive shallow ecosystem in southern Portugal, subjected to nutrient inputs from anthropogenic and natural sources. Nutrients are major abiotic drivers of phytoplankton in this system, but their effects on phytoplankton assemblages and the occurrence of nutrient limitation are still poorly understood. The main goal of this study was, thus, to evaluate the occurrence, type, and effects of nutrient limitation on phytoplankton community and specific functional groups in the Ria Formosa coastal lagoon. We conducted nutrient enrichment experiments with factorial additions of nitrogen (N) and phosphorus (P) using natural phytoplankton assemblages from distinct locations in the Ria Formosa, throughout a yearly cycle. Phytoplankton composition and abundance were evaluated using inverted and epifluorescence microscopies, and spectrophotometric methods were used for biomass. Limitation was defined as higher phytoplankton growth following enrichment with a particular nutrient in relation to the non-enriched control. The most common type of phytoplankton limitation was simultaneous co-limitation by N and P; diatoms, as r-strategists, were the most frequently limited group. Single N and P limitation, and serial P limitation were also observed, as well as negative responses to nutrient enrichment. Group-specific responses to nutrient enrichment were not reflected in the relative abundance of phytoplankton groups within the whole assemblage, due to the numerical dominance of pico-sized groups (cyanobacteria and eukaryotic picophytoplankton). Ambient nutrient ratios and concentrations did not predict phytoplankton nutrient limitation, given the different nutrient utilisation traits among phytoplankton functional groups. Therefore, nutrient ratios should not be used as indicators of nutrient limitation in eutrophication assessment.LA/P/0069/2020info:eu-repo/semantics/publishedVersio

River damming leads to decreased phytoplankton biomass and disappearance of cyanobacteria blooms

The large Alqueva dam was built in the early 2000s in the Guadiana River (southern Portugal) and has highly controlled the freshwater flowing into the Guadiana estuary, leading to significant changes in the natural hydrological regime. To evaluate the impacts of water restriction and flow regularization on estuarine phytoplankton and their environmental variables, sampling campaigns were conducted in the Guadiana estuary throughout a 14-year period, covering different phases related to the Alqueva dam construction. Significant alterations in phytoplankton and their environmental drivers were observed. In the post-filling period, river flow became more constant throughout the year and its natural seasonal variability, with maxima in the winter and minima in the summer, was greatly reduced, leading to higher river flows in the summer and lower in the winter, in relation to the pre-filling phase. Nutrient and light availability and, hence, phytoplankton dynamics, were greatly affected. Phytoplankton abundance and biomass decreased in the post-filling phase related to a decrease in diatoms and cyanobacteria. Since cyanobacteria blooms in the Guadiana are frequently dominated by toxic species, this constitutes an improvement in water quality. However, the overall decrease in phytoplankton biomass and, specifically, the decline in diatom biomass, will have major consequences for the higher trophic levels that depend on planktonic food