O fotográfico como retrato e “Readymade” a propósito de Alfred Hitchcock

Revista do IHA, N.5 (2008), pp.208-217Sempre que se fotografa alguém faz-se retrato. Retrato, precisamente segundo os critérios tradicionais da análise formal: representa-se alguém concreto com fidelidade ao visível. Se a fotografia faz, sempre, mesmo que secundariamente, retrato, isso acontece pela “natureza” do fotográfico: a fotografia é “retrato” do mundo - seu duplo mimético exacto. Não é a Verónica que faz do ícone retrato e, portanto, “verdadeiro” (verum Eikôn)? Não é a fotografia, numa das suas mais antigas e perduráveis ficções, verdadeiramente fundadora, uma verónica da Natureza? Este Mandilion, esta cópia automática do mundo, não é, também, readymade? Apropriação, ficcionalmente sem outra intervenção senão a da escolha.Fundação para a Ciência e a Tecnologia (FCT); Direcção-Geral do Livros e das Bibliotecas (DGLB

Actividade física em adultos e idosos avaliados por acelerometria

OBJECTIVE: To review the use of accelerometry as an objective measure of physical activity in adults and elderly people. METHODS: A systematic review of studies on the use of accelerometty as an objective measure to assess physical activity in adults were examined in PubMed Central, Web of Knowledge, EBSCO and Medline databases from March 29 to April 15, 2010. The following keywords were used: "accelerometry," "accelerometer," "physical activity," "PA," "patterns," "levels," "adults," "older adults," and "elderly," either alone or in combination using "AND" or "OR." The reference lists of the articles retrieved were examined to capture any other potentially relevant article. Of 899 studies initially identified, only 18 were fully reviewed, and their outcome measures abstracted and analyzed. RESULTS: Eleven studies were conducted in North America (United States), five in Europe, one in Africa (Cameroon) and one in Australia. Very few enrolled older people, and only one study reported the season or time of year when data was collected. The articles selected had different methods, analyses, and results, which prevented comparison between studies. CONCLUSIONS: There is a need to standardize study methods for data reporting to allow comparisons of results across studies and monitor changes in populations. These data can help design more adequate strategies for monitoring and promotion of physical activity.OBJETIVO: Analizar el uso de la acelerometría como medida objetiva de actividad física en adultos y ancianos. MÉTODOS: Revisión sistemática en las bases PubMed, Web of Knowledge, EBSCO y Medline, del 29 de marzo al 15 de abril de 2010. Se utilizaron en la búsqueda las palabras-clave: "accelerometry", "accelerometer", "physical activity", "PA", "patterns", "levels", "adults", "older adults" y "elderly", de forma aislada o combinadas usando "and" o "or". Las listas de referencias de los artículos recuperados fueron examinadas para encontrar artículos potenciales. De los 899 estudios localizados, 18 fueron revisados integralmente, y sus datos extraídos y analizados. RESULTADOS: Once estudios se realizaron en los Estados Unidos, cinco en Europa, uno en Camerún y otro en Australia. Pocos involucraron ancianos, y sólo uno se refirió a la estación o período del año en que transcurrió la colecta de datos. Los métodos, análisis y resultados discreparon entre los estudios, imposibilitando un análisis más a fondo. CONCLUSIONES: Se debe promover la estandarización de procedimientos que permitan comparar resultados entre estudios y monitorear alteraciones en una población. Estos datos contribuyen adecuación de las estrategias de monitoreo y promoción de la actividad física.OBJETIVO: Analisar o uso da acelerometria como medida objetiva da atividade física em adultos e idosos. MÉTODOS: Revisão sistemática nas bases PubMed, Web of Knowledge, EBSCO e Medline, de 29 de março a 15 de abril de 2010. As palavras-chave utilizadas na busca foram: "accelerometry", "accelerometer", "physical activity", "PA", "patterns", "levels", "adults", "older adults" e "elderly", isoladamente ou combinadas usando "and" ou "or". As listas de referências dos artigos recuperados foram examinadas para captar artigos potenciais. Dos 899 estudos localizados, 18 foram revistos integralmente, com seus dados extraídos e analisados. RESULTADOS: Onze estudos foram realizados nos Estados Unidos, cinco na Europa, um em Camarões e outro na Austrália. Poucos envolveram idosos, e apenas um referiu a estação ou período do ano em que decorreu a coleta de dados. Os métodos, análises e resultados divergiram entre os estudos, impossibilitando uma análise mais aprofundada. CONCLUSÕES: Deve-se promover a padronização de procedimentos que permitam comparar resultados entre estudos e monitorizar alterações numa população. Esses dados contribuem para a adequação das estratégias de monitoramento e promoção da atividade física

Effects of intervention programs on child and adolescent BMI: a meta-analysis study

This meta-analysis study aims to assess the efficacy of school-based and after-school intervention programs on the BMIs of child and adolescents, addressing the correlation between some moderating variables. Methods: We analyzed 52 studies (N = 28,236) published between 2000-2011. Results: The overall effect size was 0.068 (P < .001), school (r = .069) and after-school intervention (r = .065). Programs conducted with children aged between 15-19 years were the most effective (r = .133). Interventions programs with boys and girls show better effect sizes (r = .110) than programs that included just girls (r = .073). There were no significant differences between the programs implemented in school and after-school (P = .770). The effect size was higher in interventions lasting 1 year (r = .095), with physical activity and nutritional education (r = .148), and that included 3-5 sessions of physical activity per week (r = .080). The effect size also increased as the level of parental involvement increased. Conclusions: Although of low magnitude (r = .068), the intervention programs had a positive effect in prevention and decreasing obesity in children. This effect seems to be higher in older children's, involving interventions with physical activity and nutritional education combined, with parent's participation and with 1-year duration. School or after-school interventions had a similar effect

The influence of ACE ID and ACTN3 R577X polymorphisms on lower-extremity function in older women in response to high-speed power training

Background: We studied the influence of the ACE I/D and ACTN3 R577X polymorphisms (single or combined) on lower-extremity function in older women in response to high-speed power training. Methods: One hundred and thirty-nine healthy older Caucasian women participated in this study (age: 65.5 ± 8.2 years, body mass: 67.0 ± 10.0 kg and height: 1.57 ± 0.06 m). Walking speed (S10) performance and functional capacity assessed by the “get-up and go” (GUG) mobility test were measured at baseline (T1) and after a consecutive 12-week period of high-speed power training (40-75% of one repetition maximum in arm and leg extensor exercises; 3 sets 4–12 reps, and two power exercises for upper and lower extremity). Genomic DNA was extracted from blood samples, and genotyping analyses were performed by PCR methods. Genotype distributions between groups were compared by Chi-Square test and the gains in physical performance were analyzed by two-way, repeated-measures ANOVA. Results: There were no significant differences between genotype groups in men or women for adjusted baseline phenotypes (P > 0.05). ACE I/D and ACTN3 polymorphisms showed a significant interaction genotype-training only in S10 (P = 0.012 and P = 0.044, respectively) and not in the GUG test (P = 0.311 and P = 0.477, respectively). Analyses of the combined effects between genotypes showed no other significant differences in all phenotypes (P < 0.05) at baseline. However, in response to high-speed power training, a significant interaction on walking speed (P = 0.048) was observed between the “power” (ACTN3 RR + RX & ACE DD) versus “non-power” muscularity-oriented genotypes (ACTN3 XX & ACE II + ID)]. Conclusions: Thus, ACE I/D and ACTN3 R577X polymorphisms are likely candidates in the modulation of exercise-related gait speed phenotype in older women but not a significant influence in mobility traits.The study was developed with the aid of a research fellowship, reference number SFRH/BD/47114/2008, funded by POPH – QREN, shared by the European Social Fund and the national funds of MCTES. This work was supported in part by the Spanish Department of Health and Institute Carlos III of the Government of Spain [Spanish Net on Aging and frailty; (RETICEF)] and Economy and Competitivity Department of the Government of Spain, under grants numbered RD12/043/0002, and DEP2011-24105, respectively

Conformational study of erythritol and threitol in the gas state by density functional theory calculations

Density functional theory calculations using the B3LYP functional and the 6-311++G(d,p) basis set were carried out on the isolated molecules of erythritol and L-threitol. For the meso isomer, a relatively large number of conformers have to be considered to describe the gas state structure. The lowest energy conformer is characterized by the establishment of a strong intramolecular H-bond between the two terminal hydroxyl groups, giving rise to a seven-membered ring and two additional weaker H-bonds between vicinal OH groups. In the case of L-threitol, two conformers are predominant in the gas state, and both are stabilized by the formation of a cyclic system of four intramolecular hydrogen bonds involving all OH groups. The conformational stability in both diastereomers is discussed in terms of the electronic energy and of the Gibbs energy. The weighted mean enthalpy of both diastereomers in the gas state at 298.15 K was obtained from the thermodynamic data and Boltzmann populations of the low-energy conformers.http://www.sciencedirect.com/science/article/B6TFF-4F31PT7-3/1/ae9dae05894f1bf2f4865221eb1b29b

Sistemas híbridos de armazenamento e produção de energia

O presente documento tem como objetivo o estudo das características técnicas e económicas de sistemas de armazenamento de energia e as possibilidades, vantagens e condicionantes da sua integração em centrais de produção de energia intermitente. Numa fase posterior será apresentado o caso de estudo composto por três partes, sendo a primeira uma avaliação técnica da reconversão da central termoelétrica, respeitando o projeto proposto pela Endesa; seguindo-se uma análise do comportamento distinto do sistema de armazenamento de energia elétrica e da produção de hidrogénio, durante 3 meses de inverno e 3 meses de verão.info:eu-repo/semantics/publishedVersio

Will Casuarina glauca Stress Resilience Be Maintained in the Face of Climate Change?

Actinorhizal plants have been regarded as promising species in the current climate change context due to their high tolerance to a multitude of abiotic stresses. While combined salt-heat stress effects have been studied in crop species, their impact on the model actinorhizal plant, Casuarina glauca, has not yet been fully addressed. The effect of single salt (400 mM NaCl) and heat (control at 26/22 C, supra optimal temperatures at 35/22 C and 45/22 C day/night) conditions on C. glauca branchlets was characterised at the physiological level, and stress-induced metabolite changes were characterised by mass spectrometry-based metabolomics. C. glauca could withstand single salt and heat conditions. However, the harshest stress condition (400 mM NaCl, 45 C) revealed photosynthetic impairments due to mesophyll and membrane permeability limitations as well as major stress-specific differential responses in C and N metabolism. The increased activity of enzymatic ROS scavengers was, however, revealed to be sufficient to control the plant oxidative status. Although C. glauca could tolerate single salt and heat stresses, their negative interaction enhanced the effects of salt stress. Results demonstrated that C. glauca responses to combined salt-heat stress could be explained as a sum of the responses from each single applied stressinfo:eu-repo/semantics/publishedVersio

Zinc Biofortification in Vitis vinifera: Implications for Quality and Wine Production

Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO4 at concentrations of 150, 450, and 900 g ha1 during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO4-450 g ha1). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO4, without significantly affecting the physicochemical characteristics of grapesinfo:eu-repo/semantics/publishedVersio

Protective Responses at the Biochemical and Molecular Level Differ between a Coffea arabica L. Hybrid and Its Parental Genotypes to Supra-Optimal Temperatures and Elevated Air [CO2]

Climate changes with global warming associated with rising atmospheric [CO2] can strongly impact crop performance, including coffee, which is one of the most world’s traded agricultural commodities. Therefore, it is of utmost importance to understand the mechanisms of heat tolerance and the potential role of elevated air CO2 (eCO2) in the coffee plant response, particularly regarding the antioxidant and other protective mechanisms, which are crucial for coffee plant acclimation. For that, plants of Coffea arabica cv. Geisha 3, cv. Marsellesa and their hybrid (Geisha 3 Marsellesa) were grown for 2 years at 25/20 C (day/night), under 400 (ambient CO2, aCO2) or 700 L (elevated CO2, eCO2) CO2 L-1, and then gradually submitted to a temperature increase up to 42/30 C, followed by recovery periods of 4 (Rec4) and 14 days (Rec14). Heat (37/28 C and/or 42/30 C) was the major driver of the response of the studied protective molecules and associated genes in all genotypes. That was the case for carotenoids (mostly neoxanthin and lutein), but the maximal (a + b) carotenes pool was found at 37/28 C only in Marsellesa. All genes (except VDE) encoding for antioxidative enzymes (catalase, CAT; superoxide dismutases, CuSODs; ascorbate peroxidases, APX) or other protective proteins (HSP70, ELIP, Chape20, Chape60) were strongly upregulated at 37/28 C, and, especially, at 42/30 C, in all genotypes, but with maximal transcription in Hybrid plants. Accordingly, heat greatly stimulated the activity of APX and CAT (all genotypes) and glutathione reductase (Geisha3, Hybrid) but not of SOD. Notably, CAT activity increased even at 42/30 C, concomitantly with a strongly declined APX activity. Therefore, increased thermotolerance might arise through the reinforcement of some ROS-scavenging enzymes and other protective molecules (HSP70, ELIP, Chape20, Chape60). Plants showed low responsiveness to single eCO2 under unstressed conditions, while heat promoted changes in aCO2 plants. Only eCO2 Marsellesa plants showed greater contents of lutein, the pool of the xanthophyll cycle components (V + A + Z), and b-carotene, compared to aCO2 plants at 42/30 C. This, together with a lower CAT activity, suggests a lower presence of H2O2, likely also associated with the higher photochemical use of energy under eCO2. An incomplete heat stress recovery seemed evident, especially in aCO2 plants, as judged by the maintenance of the greater expression of all genes in all genotypes and increased levels of zeaxanthin (Marsellesa and Hybrid) relative to their initial controls. Altogether, heat was the main response driver of the addressed protective molecules and genes, whereas eCO2 usually attenuated the heat response and promoted a better recovery. Hybrid plants showed stronger gene expression responses, especially at the highest temperature, when compared to their parental genotypes, but altogether, Marsellesa showed a greater acclimation potential. The reinforcement of antioxidative and other protective molecules are, therefore, useful biomarkers to be included in breeding and selection programs to obtain coffee genotypes to thrive under global warming conditions, thus contributing to improved crop sustainabilityinfo:eu-repo/semantics/publishedVersio

Mitigation of the Negative Impact of Warming on the Coffee Crop: The Role of Increased Air [CO2] and Management Strategies

Crop sustainability can be threatened by new environmental challenges regarding predicted climate changes and global warming. Therefore, the study of real biological impacts of future environmental conditions (e.g., increased air [CO2], supra-optimal temperature and water scarcity) on crop plants, as well as the re-evaluation of management procedures and strategies, must be undertaken in order to improve crop adaptation and promote mitigation of negative environmental impacts, thus affording crop resilience. Coffee is a tropical crop that is grown in more than 80 countries, making it one of the world’s most traded agricultural products, while involving millions of people worldwide in the whole chain of value. It has been argued that this crop will be highly affected by climate changes, resulting in decreases in both suitable areas for cultivation and productivity, as well as impaired beverage quality in the near future. Here, we report recent findings regarding coffee species exposure to combined supra-optimal air temperatures and enhanced air [CO2], and impacts of drought stress on the crop. Ultimately, we discuss key strategies to improve coffee performance in the context of new environmental scenarios. The recent findings clearly show that high [CO2] has a positive impact on coffee plants, increasing their tolerance to high temperatures. This has been related to a better plant vigor, to the triggering of protective mechanisms, and to a higher functional status of the photosynthetic machinery. Even so, coffee plant is expected to suffer from water scarcity in a changing world. Therefore, discussion is focused on some important management strategies (e.g., shade systems, crop management and soil covering and terracing), which can be implemented to improve coffee performance and sustain coffee production in a continually changing environment