979 resultados para Harmful cyanobacteria


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Background Recreational use of 3,4 methylenedioxymethamphetamine (ecstasy, MDMA) is increasing worldwide. Its use by pregnant women causes concern due to potentially harmful effects on the developing fetus. MDMA, an indirect monoaminergic agonist and reuptake inhibitor, affects the serotonin and dopamine systems. Preclinical studies of fetal exposure demonstrate effects on learning, motor behavior, and memory. In the first human studies, we found prenatal MDMA exposure related to poorer motor development in the first year of life. In the present study we assessed the effects of prenatal exposure to MDMA on the trajectory of child development through 2 years of age. We hypothesized that exposure would be associated with poorer mental and motor outcomes. Materials and Methods The DAISY (Drugs and Infancy Study, 2003–2008) employed a prospective longitudinal cohort design to assess recreational drug use during pregnancy and child outcomes in the United Kingdom. Examiners masked to drug exposures followed infants from birth to 4, 12, 18, and 24 months of age. MDMA, cocaine, alcohol, tobacco, cannabis, and other drugs were quantified through a standardized clinical interview. The Bayley Scales (III) of Mental (MDI) and Motor (PDI) Development and the Behavior Rating Scales (BRS) were primary outcome measures. Statistical analyses included a repeated measures mixed model approach controlling for multiple confounders. Results Participants were pregnant women volunteers, primarily white, of middle class socioeconomic status, average IQ, with some college education, in stable partner relationships. Of 96 women enrolled, children of 93 had at least one follow-up assessment and 81 (87%) had ≥ two assessments. Heavier MDMA exposure (M = 1.3 ± 1.4 tablets per week) predicted lower PDI (p < .002), and poorer BRS motor quality from 4 to 24 months of age, but did not affect MDI, orientation, or emotional regulation. Children with heavier exposure were twice as likely to demonstrate poorer motor quality as lighter and non-exposed children (O.R. = 2.2, 95%, CI = 1.02–4.70, p < .05). Discussion Infants whose mothers reported heavier MDMA use during pregnancy had motor delays from 4 months to two years of age that were not attributable to other drug or lifestyle factors. Women of child bearing age should be cautioned about the use of MDMA and MDMA-exposed infants should be screened for motor delays and possible intervention.

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Positive psychology, an emergent branch of scholarship concerned with wellbeing and flourishing, initially defined itself by a focus on “positive” emotions and qualities. However, critics soon pointed out that this binary logic—classifying phenomena as either positive or negative, and valorising the former while disparaging the latter—could be problematic. For example, apparently positive qualities can be harmful to wellbeing in certain circumstances, while ostensibly dysphoric emotional states may on occasion promote flourishing. Responding to these criticisms, over recent years a more nuanced “second wave” of positive psychology has been developing, in which wellbeing is recognized as involving a dialectical balance of light and dark aspects of life. This article introduces this emergent second wave, arguing that it is characterized by four dialectical principles. First, the principle of appraisal states that it is difficult to categorically identify phenomena as either positive or negative, since such appraisals are fundamentally contextually dependent. Second, the principle of co-valence holds that many states and qualities at the heart of flourishing, such as love, are actually a complex blend of light and dark elements. Third, the principle of complementarity posits that not only are such phenomena co-valenced, but that their dichotomous elements are in fact co-creating, two intertwined sides of the same coin. Finally, the principle of evolution allows us to understand second-wave positive psychology as itself being an example of a dialectical process. This article is published as part of a collection entitled “On balance: lifestyle, mental health and wellbeing”.

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Tese dout., Química, Universidade do Algarve, 2005

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Tese dout., Ciências do Mar (Ecologia Marinha), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2010

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Alterations of freshwater flow regimes and increasing eutrophication can lead to alterations in phytoplankton biomass, composition, and growth in estuaries and adjacent coastal waters. Since phytoplankton is the first trophic level of most aquatic foodwebs, these changes can be propagated to other biological compartments, eventually impacting water quality and ecosystem services. However, phytoplankton responses to environmental changes in abiotic variables (e.g., light, nutrients) are additionally controlled by mortality or removal processes (e.g., grazing, horizontal advection and viral lysis). Grazing exerted by microzooplankton, usually dominated by phagotrophic protists, is considered the most relevant phytoplankton mortality factor in most aquatic systems (see Calbet, Landry 2004). In fact, grazing impact of microzooplankton can prevent phytoplankton accumulation in marine systems despite an overall increase in phytoplankton replication rate. By consequence, microzooplankton grazing may minimize problems associated to increased eutrophication and, ultimately, prevent the occurrence of harmful phytoplankton blooms. Thus, microzooplankton grazing on phytoplankton constitutes a key biological process required to understand and predict relationships between hydrological and biological processes in aquatic ecosystems and to use ecosystem properties to improve water quality and enhance ecosystem services, general principles of the Ecohydrology Concept (Zalewski 2000).

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In ecotoxicology a major focus is in the aquatic environment, not only because it presents a great economic value to man but it is an ecosystem widely affected by the growing anthropogenic pollution. Most of the studies performed relate to adverse effects in development, reproductive or endocrine disruption but little is known about the possible effects in bone formation and skeletal development. In this study, we set out to evaluate the effects of 8 aquatic pollutants on the skeletal development using an in vivo system, the zebrafish larvae aged 20 days post-fertilization, through chronic exposure. Several endpoints were considered such as the cumulative mortality, total length, occurrence of skeletal deformities and marker gene expression. We were able to establish LD50 values for some pollutants, like 3-methylcholanthrene, lindane, diclofenac, cobalt and vanadate and found that the total length was not affected by any of the pollutants tested. Cobalt was the most harmful chemical to affect hatching time, severely affecting the ability of the zebrafish embryos to hatch and overall the number of deformities increased upon exposure to tested chemicals but no patterns of deformities were identified. We also propose that 3-methylcholanthrene has an osteogenic effect, affecting osteoblast and osteoclast function and that op levels can act as a mediator of 3-methylcholanthrene toxic stress to the osteoblast. In turn we found naphthalene to probably have a chondrogenic effect. Our results provided new insights into the potential osteotoxicity of environmental pollutants. Future studies should aim at confirming these preliminary data and at determining mechanisms of osteotoxicity.

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Dissertação de mestrado, Qualidade em Análises, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

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Tese de doutoramento, Ciências Biomédicas (Biologia Celular e Molecular), Universidade de Lisboa, Faculdade de Medicina, 2014

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Tese de doutoramento, Território, Risco e Politícas Públicas, Universidade de Lisboa, Instituto de Geografia e Ordenamento do Território, Universidade de Aveiro, 2015

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Senior thesis written for Oceanography 445

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‘Making space for queer-identifying religious youth’ (2011–2013) is an Economic and Social Research Council (ESRC)-funded project, which seeks to shed light on youth cultures, queer community and religiosity. While non-heterosexuality is often associated with secularism, and some sources cast religion as automatically negative or harmful to the realisation of lesbian, gay, bisexual and transgender (LGBT) identity (or ‘coming out’), we explore how queer Christian youth negotiate sexual–religious identities. There is a dearth of studies on queer religious youth, yet an emerging and continuing interest in the role of digital technologies for the identities of young people. Based on interviews with 38 LGBT, ‘religious’ young people, this article examines Facebook, as well as wider social networking sites and the online environment and communities. Engaging with the key concept of ‘online embodiment’, this article takes a closer analysis of embodiment, emotion and temporality to approach the role of Facebook in the lives of queer religious youth. Furthermore, it explores the methodological dilemmas evoked by the presence of Facebook in qualitative research with specific groups of young people.

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Background: Parenteral nutrition is central to the care of very immature infants. Current international recommendations favor higher amino acid intakes and fish oil–containing lipid emulsions. Objective: The aim of this trial was to compare 1) the effects of high [immediate recommended daily intake (Imm-RDI)] and low [incremental introduction of amino acids (Inc-AAs)] parenteral amino acid delivery within 24 h of birth on body composition and 2) the effect of a multicomponent lipid emulsion containing 30% soybean oil, 30% medium-chain triglycerides, 25% olive oil, and 15% fish oil (SMOF) with that of soybean oil (SO)-based lipid emulsion on intrahepatocellular lipid (IHCL) content. Design: We conducted a 2-by-2 factorial, double-blind, multicenter randomized controlled trial. Results: We randomly assigned 168 infants born at ,31 wk of gestation. We evaluated outcomes at term in 133 infants. There were no significant differences between Imm-RDI and Inc-AA groups for nonadipose mass [adjusted mean difference: 1.0 g (95% CI: 2108, 111 g; P = 0.98)] or between SMOF and SO groups for IHCL [adjusted mean SMOF:SO ratio: 1.1 (95% CI: 0.8, 1.6; P = 0.58]. SMOF does not affect IHCL content. There was a significant interaction (P = 0.05) between the 2 interventions for nonadipose mass. There were no significant interactions between group differences for either primary outcome measure after adjusting for additional confounders. Imm-RDI infants were more likely than Inc-AA infants to have blood urea nitrogen concentrations .7 mmol/L or .10 mmol/L, respectively (75% compared with 49%, P , 0.01; 49% compared with 18%, P , 0.01). Head circumference at term was smaller in the Imm-RDI group [mean difference: 20.8 cm (95% CI: 21.5, 20.1 cm; P = 0.02)]. There were no significant differences in any prespecified secondary outcomes, including adiposity, liver function tests, incidence of conjugated hyperbilirubinemia, weight, length, mortality, and brain volumes. Conclusion: Imm-RDI of parenteral amino acids does not benefit body composition or growth to term and may be harmful. This trial was registered at www.isrctn.com as ISRCTN29665319 and at eudract.ema.europa.eu as EudraCT 2009-016731-34.

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Tese de Doutoramento em Biologia apresentada à Faculdade de Ciências da Universidade do Porto, 2015.

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Dissertação para a obtenção do grau de Mestre em Engenharia Electrotécnica - ramo de Energia

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Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Estruturas