949 resultados para Reforestation Indexes


Relevância:

10.00% 10.00%

Publicador:

Resumo:

RESUMO: O envelhecimento populacional saudável ocupa parte da agenda do processo do envelhecimento humano, retratando uma preocupação social com repercussões nas economias societárias. O processo de envelhecimento, quando abordado fora do paradigma do envelhecimento saudável, desconsidera socialmente o potencial humano das pessoas idosas, promovendo a segregação e motivando atitudes de preconceito e discriminação, além de desperdiçar a experiência, o saber, a cultura e a capacidade de participação da pessoa idosa como contributo para a sociedade a que ela está inserida. O foco central da Política Nacional de Saúde do Idoso brasileira se inscreve na promoção de um envelhecimento saudável, nomeadamente por meio da manutenção da capacidade funcional ao valorizar a autonomia, a independência física e a integridade mental da pessoa idosa. O desafio para a viabilização do processo de envelhecimento ativo e bem-sucedido consiste na maximização das capacidades, potencialidades e recursos pessoais, comunitários e políticos. Pressupõe, também, uma concepção ampliada de viver, contextualizada no contínuo da vida, capaz de externar a preocupação com a saúde e o bem-estar, integrando as pessoas em fase de envelhecimento no contexto do ciclo de vida. Diante do exposto, a presente investigação objetivou conhecer os determinantes de envelhecimento ativo e bem-sucedido, numa população em processo de envelhecimento e relacioná-los com as ―práticas/conteúdos‖ e representações / significados‖ sobre o envelhecimento, as atividades físicas e a capacidade funcional. A investigação foi estruturada em três estudos: no primeiro foi criado e testado o instrumento ―Envelhecimento ativo, capacidade funcional e atividade física‖, na cidade de Lisboa, Portugal, e posteriormente realizada sua adaptação cultural e linguística do português de Portugal para o do Brasil. No segundo foi feita uma pesquisa observacional do tipo survey, descritiva e exploratória com o objetivo de conhecer as relações esteabelecidas entre o envelhecimento bem-sucedido, ativo, a atividade física e a capacidade funcional de uma população em processo de envelhecimento; e no terceiro momento foi realizado um estudo de cariz qualitativo com o objetivo de captar as percepções e comportamentos dos entrevistados diante do fato de se sentirem ou não pessoas idosas ou envelhecidas. Foram adotados os seguintes referenciais teóricos: envelhecimento ativo, envelhecimento bem sucedido, concepção muldidimensional do processual do envelhecimento (determinantes pessoais, familiares, sociais, psicocomunicacionais, econômicos e de saúde), atividade física e capacidade funcional e abordados à luz do perfil demográfico e da experiência das realidades européias, americana e brasileira. Foram triagulados métodos e técnicas (entrevista individual gravada, mensurações e questionário). Participaram pessoas com 60 anos de idade ou mais vinculadas que frequentam dois programas públicos destinados às pessoas idosas na cidade de Juiz de Fora, Minas Gerais, Brasil e foram excluidas as participações de pessoas com dependência para atividades da vida diária, para as atividades instrumentais da vida diária e com alteração do nível de consciência. Amostra aleatória estratificada composta por 326 participantes na qual foram realizadas mensurações e amostra por tipicidade construída a partir da base amostral composta de 87 participantes na qual foi realizada entrevista individual gravada. Atendidos todos os requisitos éticos e legais de pesquisa envolvendo seres humanos, segundo legislação brasileira. Aplicada Análise Fatorial e selecionados 11 fatores com 31 variáveis que contemplaram os determinantes do processo de envelhecimento ativo. Realizado reajustamento da análise fatorial,por questão de coerência conceptual, sendo selecionado oito fatores nomeados de acordo com o referencial teórico adotado que resultou em 25 variáveis que abordaram a participação em atividades e acesso aos serviços de saúde; à atividade física; à convivência, interação e avaliação do contato social; à escolaridade e renda; à saúde percebida e ao voluntariado. Utilizado como marcador para a atividade aeróbia o perfil da sobrecarga da atividade física semanal em consonância com diretrizes e recomendações de atividades aeróbias de intensidade moderada para as pessoas idosas. Identificado que 60,7% dos entrevistados realizam atividade física insuficiente. Os indicadores antropométricos utilizados evidenciaram índices de sobrepeso e de obesidade tanto entre os homens quanto entre as mulheres. Houve correlação do índice de massa corporal (IMC) com as medidas efetuadas segundo as faixas etárias. A análise inferencial possibilitou relacionar os determinantes do envelhecimento ativo, as medidas antropométricas e as variáveis sociodemográficas (escolaridade e idade), sendo obtidos os seguintes destaques: 1) à medida em que a idade aumenta, diminuem os níveis de prática da atividade física, dos contatos com as pessoas para conversar (das relações de convivência), dos trabalhos de voluntariado e das relações familiares e intergeracionais; 2) foi identificado um alinhamento conceptual dos diferentes determinantes concorrentes para um envelhecimento ativo à luz da prática da atividade física com a convivência e interação com os familiares e com auto-avaliação positiva da saúde percebida e atividade física; 3) quanto maior a idade menor os anos de escolaridade; 4) a diminuição da área transversa do braço e do IMC à medida que a idade aumenta, retratou diminuição da adiposidade corporal que está associada à perda da massa magra. A categorização do discurso dos 87 entrevistados permitiu captar a percepção do processo de envelhecimento por dois critérios antagônicos: preservação da autonomia e presença da deterioração. Foi caracterizado o sistema de crenças dos participantes com 1090 emissões de crenças. Houve tendência do sistema de crenças à centralidade com 638 (58,6%) crenças retratando concepções e situações difíceis de serem modificadas por processos educacionais. Os resultados obtidos diagnosticaram e reiteraram a tendência de incremento numérico de pessoas com 60 anos de idade ou mais na cidade brasileira de Juiz de Fora. Embora o estatuto do idoso esteja alicerçado em princípios do envelhecimento saudável e ativo ficou evidenciado a necessidade de estratégias para implementá-la com vistas a impactos sociais, econômicas e de saúde na perspectiva da prática de atividade física e da preservação da capacidade funcional. Constituem contribuição da presente investigação: 1) fundamentos teóricos e informação sobre juiz-foranos com 60 anos de idade ou mais segundo dimensões social, econômica, cultural e espiritual numa concepção ampliada de saúde; 2) abordagem do envelhecimento de forma processual e integrada, multidimensional e articulada com o ciclo da vida; 3) diagnóstico do grau de autonomia dos participantes permitindo subsidiar decisões para melhorar a capacidade funcional dos mesmos; 4) processo investigativo utilizando modelos teóricos que permitiram estabelecer um diagnóstico local e contextualizar o processo de envelhecimento para os participantes e 5) sobrecarga semanal de atividade física e os indicadores antropométricos dos participantes a ponto de subsidiar parâmetros de indicação terapêutica para manutenção da capacidade funcional.-------- ABSTRACT: The populational healthy aging holds part of the process of the human aging agenda, portraying a social concern with the repercussion in societary economies. The aging process when addressed out of the healthy aging paradigm socially disregard the human potential of the elderly, promoting segregation and motivating acts of prejudice and discrimination, in addition to the waste of experience, knowledge, culture and the participatory capacity of an older person in contributting to the society they are a part of. The Brazilian National Health Policy for the Elderly has its main focus in promoting the healthy aging, namely through the maintenance of the functional capacity by valuing the autonomy, physical independence and the mental integrity of the elderly person. The challenge of enabling the process of a successful and active aging lays in maximazing the capabilities, potencialities and personal, communitary and political resources. It infers additionaly a broad view of living, contextualized in the continuum of life, able to express concern with health and well-being, integrating the people in aging phase to the context of the life cycle. Hence, this research aimed to learn the determinants of active and successful aging in a population in aging process and relate them with the "practices/contents" and "representations/meanings" about aging, the physical activities and functional capacity. The investigation was structured in three studies: in the first it was developed and tested the instrument "Active Aging, Functional Capacity and Physical Activity" in the city of Lisboa, Portugal, and afterwards it was culturally and linguistically adapted from Portugal Portuguese to Brazilian Portuguese. The second study was an observational research with survey, descriptive and exploratory methods which aimed to learn the relations established between the successful aging, active aging, the physical activity and the functional capacity of a population in aging process; and the third comprised a qualitative study with the objective to collect the understanding and behavior of the interviewees based on the fact of either they saw themselves as elder or aged person or not. As theoretical framework were explored: active aging, successful aging, multidimensional concept of aging process (personal, familial, social, psycho-communicational, economic determinants), physical activity and functional capacity and explored based in demographic profile and in the European, American a Brazilian realities. Performed triangulation of methods and tecniques (recorded individual interviews, measurements and questionnaires). Participants were aged 60 or older included in two public services for the elderly population in the city of Juiz de Fora, Minas Gerais, Brazil and were excluded persons with dependency in both daily activities and instrumental daily activities and the persons with altered level of conciousness. Stratified ramdon sample of 326 participants in which were performed the measurements and typicality sample constructed from the sample basis of 87 participants whereupon the recorded individual interview was performed. Conforming to all the ethical and legal requirements of research with human beings according to the Brazilian legislation. Applied Factor Analysis and selected 11 factors and 31 variables that convey the determinants of the active aging process. Executed reajustment of factor analysis, for conceptual coherence, being selected eight factors named accordingly to the theoretical framework that resulted in 25 variables which approached the participation in activities and access to health care services; to physical activity; to coexistence, interaction and evaluation of social contact; to scholarity and income; to perceived health and volunteering. Used as marker to aerobic activity the profile of weekly physical activity overload in accordance with guidelines and reccomendations for moderate-intensity aerobic activities for older people. Identified that 60,7% of interviewees practice enough physical activity. Anthropometric markers evidence overweight and obesity levels both within men and women. There was correlation between body mass index (BMI) and measures carried out according to age ranges. The inferential analysis allowed relating the active aging determinants, the anthropometric measurements and sociodemographic variables (scholarity and age), obtaining the following highlights: 1) to the extent that age increases, lowers the levels of physical activity practice, of contact with people to talk to (social relationships), of volunteering work and familial and intergenerational relationships; 2) it was identified a conceptual alignment of diferent determinants concurrent to an active aging in light of the physical activity practice with the relationship and interaction of family and with positive self-assessment of perceived health and physical activity; 3) the older the person, lower are scholarity levels; 4) the decrease of the cross-sectional area of the arm and BMI as the age increases portrayed decreased adiposity of the body that is associated with loss of lean body mass. The categorization of the speech of 87 interviewees allowed to collect the understanding of the aging process by two opposite criteria: preservation of autonomy and existance of decline. It marked the belief system of participants with 1090 beliefs expressed. With tendency of the belief system to centrality with 638(58,6%) beliefs showing concepts and dificult situations to be changed through educational processes. The results diagnosed and reiterated the tendency of increase in the number of people aged 60 or older in the Brazilian city of Juiz de Fora. Although the elderly statute is built upon principles of healthy and active aging it was evident the need of strategies to implement it aiming at social, economic and health impacts in the perspective of physical education and preservation of the functional capacity. Constitute contributions of this study: 1) theoretical fundaments and data about Juiz de Fora citizens aged 60 or more according to social, economic, cultural and spiritual dimensions in a broad concept of health; 2) approach of aging in a procedural and integrative, multidimensional manner, articulated with the life cycle; 3) diagnosis of degree of autonomy of participants enabling decisions on how to improve their functional capacities; 4) investigative process using theoretical models which permit to stablish a local diagnosis and contextualize the aging process of participants and 5) weekly overload of physical activity and anthropometric indexes of participants as to subsidize parameters to therapeutic indication to the maintainence of functional capacity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

INTRODUCTION: Publications are often used as a measure of success in research work. Chagas disease occurs in Central and Southern America. However, during the past years, the disease has been occurring outside Latin America due to migration from endemic zones. This article describes a bibliometric review of the literature on Chagas disease research indexed in PubMed during a 70-year period. METHODS: Medline was used via the PubMed online service of the U.S. National Library of Medicine from 1940 to 2009. The search strategy was: Chagas disease [MeSH] OR Trypanosoma cruzi [MeSH]. RESULTS: A total of 13,989 references were retrieved. The number of publications increased steadily over time from 1,361 (1940-1969) to 5,430 (2000-2009) (coefficient of determination for linear fit, R²=0.910). Eight journals contained 25% of the Chagas disease literature. Of the publications, 64.2% came from endemic countries. Brazil was the predominant country (37%), followed by the United States (17.6%) and Argentina (14%). The ranking in production changed when the number of publications was normalized by estimated cases of Chagas disease (Panama and Uruguay), population (Argentina and Uruguay), and gross domestic product (Bolivia and Brazil). CONCLUSIONS: Several Latin American countries, where the prevalence of T. cruzi infection was not very high, were the main producers of the Chagas disease literature, after adjusting for economic and population indexes. The countries with more estimated cases of Chagas disease produced less research on Chagas disease than some developed countries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

INTRODUCTION: The study analyzed positivity of polymerase chain reaction (PCR) on detection of DNA from Leishmania in patients' samples. METHODS: Extracted DNA was submitted to L150/L152, 13Y/13Z, and seminested PCR (snPCR). RESULTS: Results were evidenced by bands of approximately 120, 720, and 670 bp for L150/L152, 13Y/13Z, and snPCR, respectively. L150/L152, 13Y/13Z, and snPCR positivity indexes were 76.9, 56.4, and 9.2 (p>0.05), respectively, for suspected and 93.7, 68.7, and 84.4 (p<0.05), respectively, for confirmed. CONCLUSIONS: Preliminary results showed that these assays, mainly L150/L152 and snPCR, can detect Leishmania DNA and carry potential on laboratory diagnosis of leishmaniasis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Taking a Media Anthropology’s approach to dynamics of mediated selfrepresentation in migratory contexts, this thesis starts by mapping radio initiatives produced by, for and/or with migrants in Portugal. To further explore dynamics of support of initial settlement in the country, community-making, cultural reproduction, and transnational connectivity - found both in the mapping stage and the minority media literature (e.g. Kosnick, 2007; Rigoni & Saitta, 2012; Silverstone & Georgiou, 2005) - a case study was selected: the station awarded with the first bilingual license in Portugal. The station in question caters largely to the British population presenting themselves as “expats” and residing in the Algarve. The ethnographic strategy to research it consisted of “following the radio” (Marcus, 1995) beyond the station and into the events and establishments it announces on air, so as to relate production and consumption realms. The leading research question asks how does locally produced radio play into “expats” processes of management of cultural identity – and what are the specificities of its role? Drawing on conceptualizations of lifestyle migration (Benson & O’Reilly, 2009), production of locality (Appadurai 1996) and the public sphere (Butsch, 2007; Calhoun & et al, 1992; Dahlgren, 2006), this thesis contributes to valuing radio as a productive gateway to research migrants’ construction of belonging, to inscribe a counterpoint in the field of minority media, and to debate conceptualizations of migratory categories and flows. Specifically, this thesis argues that the station fulfills similar roles to other minority radio initiatives but in ways that are specific to the population being catered to. Namely, unlike other minority stations, radio facilitates the process of transitioning between categories along on a continuum linking tourists and migrants. It also reflects and participates in strategies of reterritorialization that rest on functional and partial modes of incorporation. While contributing to sustain a translocality (Appadurai, 1996) it indexes and fosters a stance of connection that is symbolically and materially connected to the UK and other “neighborhoods” but is, simultaneously, oriented to engaging with the Algarve as “home”. Yet, besides reifying a British cultural identity, radio’s oral, repetitive and ephemeral discourse particularly trivializes the reproduction of an ambivalent stance of connection with place that is shared by other “expats”. This dynamic is related to migratory projects driven by social imaginaries fostered by international media that stimulate the search for idealized ways of living, which the radio associates with the Algarve. While recurrently localizing and validating the narrative projecting an idealized “good life”, radio amplifies dynamics among migrants that seem to reaffirm the migratory move as a good choice.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A Work Project, presented as part of the requirements for the Award of a Master’s Double Degree in Finance and Financial Economics from NOVA – School of Business and Economics and Maastricht University

Relevância:

10.00% 10.00%

Publicador:

Resumo:

INTRODUCTION : Exercise-induced ventricular arrhythmia (EIVA) and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD) patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS : A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5) years, and 38 healthy individuals, aged 44.0 (9.2) years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS : The occurrence of EIVA was higher in the chagasic group (48%) than in the control group (23.7%) during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS : ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Abstract: INTRODUCTION Natural and artificial ecotope infestation by the kissing bug triatomines and their colonization and infection by Trypanosoma cruzi , the Chagas disease agent, were evaluated in nine municipalities of the State of Rio Grande do Norte, Brazil. METHODS Following identification, triatomine intestinal contents were analyzed by direct microscopic examination, xenoculture, and polymerase chain reaction (PCR) for parasite detection. Trypanosoma cruzi isolates were genotyped using three different markers. RESULTS Of 842 triatomines captured, 65% were Triatoma brasiliensis , 17.8% Triatoma pseudomaculata , 12.5% Panstrongylus lutzi , and 4.7% Rhodnius nasutus . Triatoma brasiliensis and P. lutzi adults were found in the intradomicile. T. brasiliensis, T. pseudomaculata , and R. nasutus nymphs and adults were found in the peridomicile and wild environment. Intradomiciliary and peridomiciliary infestation indexes were 5.6% and 33.7%, respectively. In the peridomicile, chicken coops were the most infested ecotope. The T. cruzi triatomine infection rate was 30.2%, of which PCR detected 29%. P . lutzi (78.1%), T . brasiliensis (24.5%), and T . pseudomaculata (22.7%) were the most infected species. TcII and III genotypes were detected in T. brasiliensis and TcIII in P. lutzi . CONCLUSIONS T. brasiliensis was found in all environments and most ecotopes with high T. cruzi infection rates. High infection rates were also detected in T . pseudomaculata and P. lutzi , suggesting their role in the interchange between the wild and peridomestic transmission cycles. The combination of PCR, microscopic examination, and xenoculture contributed to improving T. cruzi infection evaluation in triatomine bugs. The TcII and TcIII genotypes were predominant in the study area.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Hyperbaric oxygen has been successfully used on treatment of acute ischemic injuries involving soft tissues and chronic injuries. In nerve crush injuries, the mechanisms involved are very similar to those found in ischemic injuries. Consequently, it is logical to hypothesize that hyperbaric oxygen should improve nerve repair, which is a critical step on functional recovery. In the present study, we created standard nerve crush injuries on sciatic nerves of rats, which underwent treatment with hyperbaric oxygen. Results were assessed by functional evaluation using walking-track analysis. The functional recovery indexes observed did not differ from control group. We concluded that hyperbaric oxygen therapy, in the schedule used, had no influence on functional recovery after nerve crush injuries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE: It has been shown that the temporomandibular joint is frequently affected by juvenile idiopathic arthritis, and this degenerative disease, which may occur during facial growth, results in severe mandibular dysfunction. However, there are no studies that correlate oral health (tooth decay and gingival diseases) and temporomandibular joint dysfunction in patients with juvenile idiopathic arthritis. The aim of this study is to evaluate the oral and facial characteristics of the patients with juvenile idiopathic arthritis treated in a large teaching hospital. METHOD: Thirty-six patients with juvenile idiopathic arthritis (26 female and 10 male) underwent a systematic clinical evaluation of their dental, oral, and facial structures (DMFT index, plaque and gingival bleeding index, dental relationship, facial profile, and Helkimo's index). The control group was composed of 13 healthy children. RESULTS: The mean age of the patients with juvenile idiopathic arthritis was 10.8 years; convex facial profile was present in 12 juvenile idiopathic arthritis patients, and class II molar relation was present in 12 (P = .032). The indexes of plaque and gingival bleeding were significant in juvenile idiopathic arthritis patients with a higher number of superior limbs joints involved (P = .055). Anterior open bite (5) and temporomandibular joint noise (8) were present in the juvenile idiopathic arthritis group. Of the group in this sample, 94% (P = .017) had temporomandibular joint dysfunction, 80% had decreased mandibular opening (P = 0.0002), and mandibular mobility was severely impaired in 33% (P = .015). CONCLUSION: This study confirms that patients with juvenile idiopathic arthritis a) have a high incidence of mandibular dysfunction that can be attributed to the direct effect of the disease in the temporomandibular joint and b) have a higher incidence of gingival disease that can be considered a secondary effect of juvenile idiopathic arthritis on oral health.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

RESUMO - A definição e medição da produção são questões centrais para a administração hospitalar. A produção hospitalar, quando se consideram os casos tratados, baseia-se em dois aspectos: a definição de sistemas de classificação de doentes como metodologia para identificar produtos e a criação de índices de casemix para se compararem esses mesmos produtos. Para a sua definição e implementação podem ser consideradas características relacionadas com a complexidade dos casos (atributo da oferta) ou com a sua gravidade (atributo da procura), ou ainda características mistas. Por sua vez, a análise do perfil e da política de admissões dos hospitais adquire um maior relevo no contexto de novas experiências previstas e em curso no SNS e da renovada necessidade de avaliação e regulação que daí decorrem. Neste estudo pretendeu-se discutir a metodologia para apuramento do índice de casemix dos hospitais, introduzindo- se a gravidade dos casos tratados como atributo relevante para a sua concretização. Assim, foi analisada uma amostra de 950 443 casos presentes na base de dados dos resumos de alta em 2002, tendo- -se dado particular atenção aos 31 hospitais posteriormente constituídos como SA. Foram considerados três índices de casemix: índice de complexidade (a partir do peso relativo dos DRGs), índice de gravidade (a partir da escala de mortalidade esperada do disease staging recalibrada para Portugal) e índice conjunto (média dos dois anteriores). Verificou-se que a análise do índice de complexidade, de gravidade e conjunto dá informações distintas sobre o perfil de admissões dos hospitais considerados. Os índices de complexidade e de gravidade mostram associações distintas às características dos hospitais e dos doentes tratados. Para além disso, existe uma diferença clara entre os casos com tratamento médico e cirúrgico. No entanto, para a globalidade dos hospitais analisados observou-se que os hospitais que tratam os casos mais graves tratam igualmente os mais complexos, tendo-se ainda identificado alguns hospitais em que tal não se verifica e, quando possível, apontado eventuais razões para esse comportamento.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper studies the changes in European stock market indexes composition from 1995 to 2015. It was found that there are mixed price effects producing abnormal returns around the effective replacement of added and deleted stocks. The price pressure hypothesis seems to hold for added stocks in some indexes but not for deleted stocks as there is not a clear inversion of behaviour after the replacement. Finally, the building and back testing of a trading strategy aiming to capture some of those abnormal returns shows it yields a Sharpe Ratio of 1.4 and generates an annualised alpha of 11%.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The objective of this work is to develop an operational tool to analyze exchange rate pressure in the context of Angola. The Angolan economy exhibits a number of relevant characteristics: a closed financial account, a partially controlled current account, a highly dollarized economy and exports (oil) price determined in World markets. These features have a direct effect on the demand of foreign currency and motivate their inclusion in the specification of a model for Angola. The model provides the rational for a measure of an exchange market rate pressure (EMP) index that contains exports changes, imports changes, the foreign interest rate and inflation and the change in foreign reserves corrected for a measure dollarization. The empirical performance new measure is comparable (slightly better) to the performance of the EMP indexes obtained in Eichengreen Rose and Wyplosz (1994) and Klassen and Jager (2011).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the Brazilian Amazon, large areas of abandoned lands may revert to secondary forest. In the process, pioneer tree species have an important role to restore productivity in old fields and improve environmental conditions. To determine potential photosynthesis (Apot), stomatal conductance (g), transpiration (E), and leaf micronutrient concentrations in Ochroma pyramidale (Cav. ex Lam.) Urban a study was carried out in the Brazilian Amazon (01o 51' S; 60o 04' W). Photosynthetic parameters were measured at increasing [CO2], saturating light intensity (1 mmol (photons) m-2 s-1), and ambient temperature. The rate of electron-transport (J), Apot,and water-use efficiency (WUE) increased consistently at increasing internal CO2 concentration (Ci). Conversely, increasing [CO2] decreased gs, E, and photorespiration (Pr). At the CO2-saturated region of the CO2 response curve (1.1 mmol (CO2) mol-1(air), J was 120 μmol (e-) m-2s-1 and Apot reached up to 24 μmol (CO2) m-2s-1. Likewise, at saturating C1 g and E were 30 and 1.4 mmol (H2O) m-2s-1, respectively, and P 2 r about 1.5 μmol (CO2) m-2s-1. Foliar nutrients were 185, 134, 50, and 10 μmol (element) m-2 (leaf area) for Fe, Mn, Zn, and Cu, respectively. It was concluded that [CO ] probably limits light saturated photosynthesis in this site. Furthermore, from a nutritional point of view, the low Fe to Cu ratio (15:1) may reflect nutritional imbalance in O. pyramidale at this site.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Timber frame buildings are well known as an efficient seismic resistant structure popular all over the world not only due to their seismic performance, but also to their low cost and the strength they offer. These constructions still exist today and it is important to be able to preserve them, so a better knowledge on their behaviour is sought. Furthermore, historic technologies could be used even in modern constructions to build seismic resistant buildings using more natural materials with lesser costs. A great rehabilitation effort is being carried out on this type of buildings, as their neglect has led to decay or their change in use and alterations to the structure has led to the need to retrofit such buildings; only recently studies on their behaviour have become available and only a few of them address the issue of possible strengthening techniques for this kind of walls. In this scope, an innovative retrofitting technique (near surface mounted steel flat bars) is proposed and validated on traditional timber frame walls based on an extensive experimental program. The results of the static cyclic tests on distinct wall typologies retrofitted with the NSM technique are herein presented and discussed in detail. The main features on deformation, lateral stiffness, lateral resistance and seismic performance indexes are analysed

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Timber frame construction is characteristic of several historic city centres as well as of vernacular architecture in several countries around the world, either motivated by the availability of materials and construction traditions or by the need of reducing the seismic vulnerability of buildings, namely in south European countries, where this construction technique was adopted for seismic-resistance purposes. From past earthquakes, it has been seen that timber frame construction can be viewed as an interesting technology as it has exhibited a very reasonable behaviour when compared to other traditional construction techniques such as masonry walls. This chapter provides an overview of the main insights on the seismic performance of timber frame buildings from the evidences of past earthquakes and provides the main results of recent research focused on the in-plane cyclic behavior of timber frame walls with distinct geometrical configurations. Additionally, the main seismic performance indexes of timber frame walls, both unreinforced and retrofitted, are presented and discussed in detail.