Cultivo de microalgas unicelulares para determinação da produção lipídica e sequestro de carbono

Tese de mestrado. Biologia (Biologia Celular e Biotecnologia). Universidade de Lisboa, Faculdade de Ciências, 2011O uso de microalgas como fonte de biocombustível adquire grande relevância, numa altura em que o mundo se depara com uma crise energética, devido à depleção do petróleo e outros combustíveis fósseis, cujo uso crescente e continuado, desde a industrialização, tem conduzido à degradação ambiental. As grandes vantagens da utilização destes microorganismos como matéria-prima na produção de biocombustível residem: no facto de as consequentes emissões de CO2 corresponderem à quantidade sequestrada deste gás, através da fotossíntese, durante o crescimento da biomassa; na grande capacidade de fixar dióxido de carbono e de acumular lípidos. Desta forma, a presente dissertação teve como principal finalidade o cultivo de clorófitas unicelulares, Ankistrodesmus fusiformis e Scenedesmus sp.1, de modo a determinar o sequestro de carbono (medição da produtividade primária) e a produção lipídica, visando a possível obtenção de biodiesel. O cultivo em fotobioreactores air-lift permitiu elevadas taxas de crescimento e produtividade da biomassa. Em geral, evidenciou-se aumento da concentração dos pigmentos na fase estacionária e redução dos parâmetros fotossintéticos rETRmax, α e Fv/Fm nesta mesma fase, relativamente à exponencial. A aplicação das metodologias de determinação da produtividade primária (método de Winkler e método do 14C) permitiram verificar uma elevada e maior capacidade fotossintética em Scenedesmus sp.1, PBmax=57 μmol O2 (mg Chla)-1h-1 e 225,4 μmolC(mg Chla)-1h-1, comparativamente a Ankistrodesmus fusiformis, PBmax=31 μmol O2 (mg Chla)-1h-1 e 165,5 μmol C (mg Chla)-1h-1. A produção lipídica das espécies foi semelhante, quer observando os resultados obtidos para o conteúdo lipídico, quer pelo perfil de ácidos gordos. O conteúdo lipídico total em Ankistrodesmus fusiformis foi de 17,1% (fase estacionária); em Scenedesmus sp.1 foi de 18,3% (fase exponencial) e 14,9% (fase estacionária). Embora estes valores não sejam muito elevados, a predominância do ácido palmítico (16:0) e ácido oleico (18:1) nas fases do crescimento das espécies, torna estas algas adequadas para a produção de biodiesel. Os valores máximos registados corresponderam a C18:1, na fase estacionária, tanto em Ankistrodesmus fusiformis (37,8±6,9 %) como em Scenedesmus sp.1 (38,2 ±2,4 %). Os resultados e conclusões obtidos fazem valer a pena a concretização de mais estudos relativos à optimização das condições de cultura destas microalgas, visando um maior sequestro de carbono e maior produção lipídica.The use of microalgae as biofuel source gathers great relevance in a time when world faces an energy crisis, due to oil and other fossil fuels depletion, whose continued and growing use, since the industrialization, has been leading to environmental degradation. The great use advantages of these microorganisms, as feedstock in biofuel production, reside: in fact of the resulting CO2 emissions match the sequestered quantity of this gas, through photosynthesis, during biomass growth; microalgae have great capacity to fixate carbon dioxide and to accumulate lipids. Thus, this dissertation had as its main purpose, the cultivation of unicellular chlorophyte, Ankistrodesmus fusiformis and Scenedesmus sp.1, to determine the carbon sequestration (measurement of primary productivity) and lipid production, possible in order to obtain biodiesel. The cultivation in air-lift photobioreactors allowed high growth rates and biomass productivity. In general, there was increasing concentration of pigments and reduction of photosynthetic parameters rETRmax, α and Fv/Fm, in the stationary phase, concerning the exponential phase. The application of primary productivity determination methodologies (Winkler and 14C methods) allowed confirmation of a high and higher photosynthetic capacity in Scenedesmus sp.1, PBmax=57 μmol O2 (mg Chla)-1h-1 and 225,4 μmol C (mg Chla)-1h-1, comparatively to Ankistrodesmus fusiformis, PBmax=31 μmol O2 (mg Chla)-1h-1 and 165,5 μmol C (mg Chla)-1h-1. The lipid production of both species was alike, whether looking at the lipid content results, either by the fatty acid profile. The total lipid content of Ankistrodesmus fusiformis was 17.1% (stationary phase); in Scenedesmus sp.1 was 18,3% (exponential phase) and 14.9% (stationary phase). Although these numbers are not very high, the predominance of palmitic acid (16:0) and oleic acid (18:1) in the species growth phases, makes these algae proper for biodiesel production. The top values recorded corresponded to C18:1, in the stationary phase, both in Ankistrodesmus fusiformis (37,8 ±6,9 %) as in Scenedesmus sp.1 (38,2 ±2,4 %). The obtained results and conclusions make worth the execution of more studies on the optimization of culture conditions for these microalgae, aiming a greater carbon sequestration and a bigger lipid production

características clínicas e revisão da literatura

Introdução: A Hipomineralização incisivo-molar (HIM) é uma patologia de origem sistémica caracterizada pela redução da mineralização de um a quatro primeiros molares permanentes, podendo também afetar os incisivos permanentes. Objetivo: A presente revisão da literatura tem como objetivo sistematizar o conhecimento existente sobre HIM, assumindo como foco de discussão central, a caracterização do quadro clínico e o padrão de distribuição das lesões observadas nas crianças com HIM. Metodologia: Realizou-se uma pesquisa bibliográfica nas bases de dados MEDLINE, PubMed, B-on, ScienceDirect, Elsevier e Google Académico, com as palavras-chave “molar incisor hypomineralization”, ”prevalence”, “amelogenesis”, “ etiology”, “clinical features”, “diagnosis”, “differential diagnosis” e “treatment” conjugadas com os conectores boleanos “AND” e “OR”. Os critérios de inclusão foram: artigos em inglês, espanhol e português, com data de publicação nos últimos 20 anos. Foram considerados relevantes 68 artigos. Na observação, foram observadas 18 crianças com idades compreendidas entre os 8 e os 14 anos de um total de 238 crianças rastreadas nas escolas. Como critérios de inclusão, foram incluídas crianças com idades compreendidas entre os 7 e os 16 anos, que apresentavam pelo menos um dos primeiros molares permanentes com HIM. Nos critérios de exclusão, foram consideradas não elegíveis, crianças com opacidades 2mm, FPE, sensibilidade dentária, restaurações atípicas, carie dentária e extrações devido a HIM. Resultados: Das 18 crianças observadas 7.6% tinham HIM. Dos 216 dentes observados, 25.9% tinham HIM ligeira, 17.1 % tinham HIM severa, 43.1% tinham opacidades >2mm, 6.9% tinham FPE, 15.7% tinham sensibilidade dentária, 8.3% tinham restaurações atípicas, 7.9% tinham carie dentária e 0.9% foram extraídos devido a HIM. Conclusão: A HIM é um defeito qualitativo do esmalte de etiologia desconhecida. A sua prevalência diverge de acordo com os critérios de diagnóstico e metodologia utilizada, pelo que são necessários mais estudos.Introduction: Molar-incisor hypomineralization (MIH) is a pathology of systemic origin characterized by the reduction of mineralization from one to four first permanent molars, which often also affects permanent incisors. Objective: This literature review aims to systematize the existing knowledge about HIM, taking as a central discussion the characterization of the clinical picture and the pattern of distribution of lesions observed in children with MIH. Methodology: A bibliographic search was carried out in the Medline, PubMed, B-on, ScienceDirect, Elsevier and Academic Google databases, with the keywords “molar incisor hypomineralization”, ”prevalence”, “amelogenesis”, “etiology”, “clinical features”, “diagnosis”, “differential diagnosis” and “treatment” combined with the “AND” and “OR” boolean connectors. The inclusion criteria were: articles in English, Spanish and Portuguese, published in the last 20 years. 68 articles were considered relevant. In observation, 18 children aged between 8 and 14 were observed out of a total of 238 children screened in schools. As inclusion criteria, children aged between 7 and 16 years, who had at least one of the first permanent molars with MIH, were included. The exclusion criteria, children with opacities 2mm, FPE, tooth sensitivity, atypical restorations, tooth decay and extractions due to MIH were recorded. Results: Of the 18 children observed, 7.6% had MIH. Of the 216 teeth observed, 25.9% had mild MIH, 17.1% had severe MIH, 43.1% had opacities >2mm, 6.9% had FPE, 15.7% had tooth sensitivity, 8.3% had atypical restorations, 7.9% had dental caries and 0.9% were extracted due to MIH. Conclusion: MIH is a qualitative enamel defect of unknown etiology. Its prevalence differs according to the diagnostic criteria and methodology used, so further studies are needed

Purposes of Performance Appraisal: A Systematic Review and Agenda for Future Research

Purpose: This study expands the knowledge on theoretical and practical performance appraisal purposes (PAPs) explanations.   Theoretical framework: Performance Appraisal (PA) has already demonstrated its peculiar characteristic of being the foundation on which decision-making on other Human Resource (HR) policies is based, such as salary increase, training, identification and separation of poor performance. Despite that, there is a general understanding that among the criteria for measuring performance appraisal effectiveness, PAPs have been little explored by academics and researchers. However, the importance of PAPS in employees' reactions is recognized.   Design/methodology/approach: Based on a systematic literature review, we synthesized 24 peer-reviewed journal papers published in the last ten years: 2012-2022.   Findings: The descriptive results suggest that there has been a decrease in interest in researching on PAPs. At some time, the thematic results suggest that PAPs have been operationalized as an independent variable.   Research, Practical & Social implications: Our findings broaden the understanding on PAPs in different cultural and organizational contexts, especially in Asia and Africa. On the other hand, this article can help to improve the perception of appraisers and appraisees on the usefulness of the appraisal system. This way, helping to reduce the prevailing perception that RH practices are not efficient and effective.   Originality/value: The line of investigation on PAPs is aligned with previous research whose prevailing domain of administrative and development purposes is still a reality in studies on the topic. However, the novelty in this study is the growing concern with the accuracy and reliability dimension of PAPs

Balanço económico e de carbono da exploração agrícola Maria Joana Velez do Peso de Moura e Herdeiros

Mestrado em Engenharia Agronómica / Instituto Superior de Agronomia. Universidade de LisboaAs Alterações Climáticas constituem uma das problemáticas mais preocupantes e, por isso, mais importantes dos dias de hoje. Tendo em conta a urgência e a importância do fenómeno das alterações climáticas e a responsabilidade, ainda que modesta (menos de 10%), do sector agrícola no problema, é necessária a adoção de soluções conducentes à redução das suas emissões de gases com efeito de estufa (GEE). Neste trabalho pretende-se perceber o impacto económico e ambiental de um projeto real de investimento levado a cabo na exploração agrícola “Maria Joana Velez do Peso de Moura e Herdeiros”, situada no distrito de Portalegre, no concelho de Monforte, dedicando-se principalmente à produção agropecuária extensiva em modo produção biológico. O objetivo principal deste estudo é, pois, o de apurar se com a implementação deste projeto, alcançaremos não só o ganho económico esperado, mas também uma redução do impacte ambiental da atividade agrícola na referida exploração. As emissões e sequestro de carbono são calculadas através da metodologia do IPCC metodologia também utilizada pela APA para a elaboração do Relatório do Inventário Nacional, segundo a metodologia do ICNF para a elaboração do Inventário Florestal e segundo o Introductory Carbon Balance. Para avaliar a viabilidade económica do projeto de investimento são calculados indicadores usualmente utilizados numa análise de investimento, o valor atualizado líquido, a taxa interna de rentabilidade, o período de recuperação e o acréscimo de benefício líquidoN/

Trauma Exposure and Mental Health Problems Among Adults in Central Vietnam: A Randomized Cross-Sectional Survey

Background: There is relatively little evidence about the psychological and social impacts of trauma exposure in the general population in East Asian countries. Vietnam has a long history of war and poverty, is prone to natural disasters and has high mortality related to traffic accidents. The mental health systems may be inadequate to cope with the resultant trauma.Objectives: This research examines the lifetime prevalence of single and multiple traumas and the association between trauma exposure and depression, anxiety and post-traumatic stress disorder (PTSD) among a randomly selected sample of the adult population in Thua Thien-Hue province in central Vietnam.Methods: Six hundred and eight Vietnamese adults aged 18 years or older participated in the survey. The main tools in the face-to-face interview included the Life Event Checklist (LEC) to measure trauma exposure, the Hospital Anxiety and Depression Scale (HADS) and the PTSD Checklist for DSM-IV (PCL-IV). Hierarchical multiple logistic regression was used to examine associations between trauma exposure and mental health.Results: Forty seven percent of the participants experienced at least one traumatic event in their lifetime and about half of these people were exposed to multiple traumas. The prevalence of depression, anxiety, and PTSD symptoms among the total sample was 12.7, 15.5, and 6.9%, respectively. Prevalence of PTSD among those reporting trauma exposure was 14.8%. Exposure to a higher number of trauma types was associated with increased risk of having depression, anxiety, and PTSD symptoms. Interpersonal traumas were strongly associated with symptoms of all three mental disorders while non-interpersonal traumas were only associated with depressive symptoms.Conclusion: Our findings indicate high burden of lifetime trauma and mental ill health in the adult population of central Vietnam and show a cumulative effect of multiple traumas on symptoms of the three mental disorders. Interpersonal trauma appears to have a more harmful effect on mental health than non-interpersonal trauma. Efforts to improve mental health in Vietnam should focus on reducing risk of preventable interpersonal trauma in every stage of life, and more broadly, ensure greater availability of trauma-sensitive mental health programs and services

A prevalência de suicídio em idosos da região nordeste: Um estudo ecológico The prevalence of suicide in elderly people from the northeast region: An ecological study

 O suicídio na população idosa aumentou de maneira alarmante o mundo. De acordo com a OMS, os números de suicídio são elevados em pessoas com idade acima de 70 anos em quase todas as regiões do planeta. Um estudo realizado com 530 idosos atendidos pela Estratégia Saúde da Família constatou que 15,7% dos idosos apresentavam risco de suicídio.  Semelhantemente, outros autores destacam que mais de dois terços dos idosos procuraram atendimento na ESF trinta dias antes de se suicidar. O objetivo deste estudo é analisar a prevalência de suicídios em idosos na região Nordeste do Brasil. Trata-se de um estudo descritivo, ecológico de abordagem quantitativa sobre prevalência de suicídio no Nordeste brasileiro entre os anos de 2012 a 2016. Entre os cinco anos estudados, ocorreram 2120 casos de suicídio em idosos apenas na região Nordeste do país. Houve um aumento de 1,6 % entre os anos de 2015 e 2016. O suicídio em idosos deve ser visto com atenção, pois se trata de uma população que está convivendo com questões sociais que não são debatidas em nosso cotidiano.  

BeaverCube: Coastal Imaging with VIS/LWIR CubeSats

BeaverCube is a student-built 3U CubeSat that has two main objectives: one science objective and one technology objective. The science goal of BeaverCube is to demonstrate that it is possible to develop and apply platforms that can leverage statistical relationships between temperature and co-varying bio-optical properties, such as light absorption by colored dissolved organic matter. The technology goal of BeaverCube is to demonstrate electrospray propulsion for CubeSats, enabling more coordinated and targeted science missions among multiple spacecraft. The science objective for BeaverCube involves measuring temperature and color, which are key oceanographic properties, through a low-cost platform. Temperature and salinity are used to determine the density of watermasses. This is then used to physically classify them. Thermohaline circulation is a part of large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes. Thermohaline circulation plays an important role in supplying heat to the polar regions; it influences the rate of sea ice formation near the poles, which in turn affects other aspects of the climate system, such as the albedo, and thus solar heating, at high latitudes. Small- and meso-scale ocean features such as fronts and eddies canal so be identified and tracked solely using sea surface temperature properties. BeaverCube will track warm core rings on the Northeastern section of the US coast, one of the regions in the world that is heating the fastest due to climate change. Wide geospatial coverage with near-simultaneous measurements of thermal and bio-optical ocean properties by a CubeSat has the potential to address many important oceanographic questions for both basic science and Naval applications. The majority of space-borne optical oceanographic parameters observed from CubeSats rely on atmospheric corrections to provide useful data. BeaverCube will both obtain data and help determine to what extent supplemental data will still be required for atmospheric corrections. BeaverCube will make sea surface and cloud top temperature measurements using three cameras: one visible and two FLIR Boson LWIR cameras. In-situ measurements will be coordinated with an array of ocean buoys to support calibration and validation. The student team successfully tested the LWIR camera on a high-altitude balloon launch in November 2019 to an altitude of 110,000 feet, demonstrating the imaging functionality in a near-space environment. The technology goal for BeaverCube is to demonstrate the operation of the Tiled Ionic Liquid Electrospray (TILE2) propulsion technology from Accion Systems, Inc. for orbital maneuvering. BeaverCube will be deployed in Low Earth Orbit from the International Space Station. The plan is to change the altitude of BeaverCube by 480 meters using 50 micro-Newtons of thrust, detected by an onboard GPS receiver. With a goal of launching in late 2020 or early 2021, BeaverCube passed Critical Design Review in Spring 2020, with subsystems designed and procured, including components from AAC Clyde Space (power), ISIS (ADCS), Near Space Launch (BlackBox with GlobalStar simplex radio and NovAtel GPS), and others (OpenLST radio and Raspberry Pi based C&DH board). Assembly and integration prior to environmental testing are planned for late summer 2020

Travel risk behaviours and uptake of pre-travel health preventions by university students in Australia

<p>Abstract</p> <p>Background</p> <p>Forward planning and preventative measures before travelling can significantly reduce the risk of many vaccine preventable travel-related infectious diseases. Higher education students may be at an increased risk of importing infectious disease as many undertake multiple visits to regions with higher infectious disease endemicity. Little is known about the health behaviours of domestic or international university students, particularly students from low resource countries who travel to high-resource countries for education. This study aimed to assess travel-associated health risks and preventative behaviours in a sample of both domestic and international university students in Australia.</p> <p>Methods</p> <p>In 2010, a 28 item self-administered online survey was distributed to students enrolled at the University of New South Wales, Sydney, Australia. Multiple methods of distributing links to the online survey were utilised. The survey examined the international travel history, travel intentions, infection control behaviours and self-reported vaccination history.</p> <p>Results</p> <p>A total of 1663 respondents completed the online survey, 22.1% were international students and 83.9% were enrolled at an undergraduate level. Half had travelled internationally in the previous 12 months, with 69% of those travelling only once during that time with no difference in travel from Australia between domestic and international students (<it>p </it>= 0.8). Uptake of pre-travel health advice was low overall with 68% of respondents reporting they had not sought any advice from a health professional prior to their last international trip. Domestic students were more likely to report uptake of a range of preventative travel health measures compared to international students, including diarrhoeal medication, insect repellent, food avoidance and condoms (<it>P </it>< 0.0001). Overall, students reported low risk perception of travel threats and a low corresponding concern for these threats.</p> <p>Conclusions</p> <p>Our study highlights the need to educate students about the risk associated with travel and improve preventative health-seeking and uptake of precautionary health measures in this highly mobile young adult population. Although immunisation is not an entry requirement to study at Universities in Australia, large tertiary institutions provide an opportunity to engage with young adults on the importance of travel health and provision of vaccines required for travel, including missed childhood vaccines.</p