909 resultados para change factors
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Land cover change in the Neotropics represents one of the major drivers of global environmental change. Several models have been proposed to explore future trajectories of land use and cover change, particularly in the Amazon. Despite the remarkable development of these tools, model results are still surrounded by uncertainties. None of the model projections available in the literature plausibly captured the overall trajectory of land use and cover change that has been observed in the Amazon over the last decade. In this context, this study aims to review and analyze the general structure of the land use models that have most recently been used to explore land use change in the Amazon, seeking to investigate methodological factors that could explain the divergence between the observed and projected rates, paying special attention to the land demand calculations. Based on this review, the primary limitations inherent to this type of model and the extent to which these limitations can affect the consistency of the projections will also be analyzed. Finally, we discuss potential drivers that could have influenced the recent dynamic of the land use system in the Amazon and produced the unforeseen land cover change trajectory observed in this period. In a complementary way, the primary challenges of the new generation of land use models for the Amazon are synthesized. (c) 2014 Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Orange juice consumption can promote lower levels of oxidative stress and inflammation due to the antioxidant activity of citrus flavonoids and carotenoids. In addition, red-fleshed sweet orange juice (red orange juice) also contains lycopene. This study investigated the effects of red orange juice consumption on risk factors for metabolic syndrome. Volunteers consumed red orange juice daily for 8 weeks, with clinical and biochemical assessments performed at baseline and on the final day. There was no change in the abdominal obesity, but low-density lipoprotein cholesterol, C-reactive protein decreased, while there was an increase of the antioxidant activity in serum after red orange juice consumption. Insulin resistance and systolic blood pressure were reduced in normal-weight volunteers, while diastolic blood pressure decreased in overweight volunteers after intervention. Red orange juice showed anti-inflammatory, antioxidant, and lipid-lowering properties that may prevent the development of metabolic syndrome.
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The aim of this study was to investigate the rheological properties and antibacterial efficacy of chitosan/ alpha-hydroxy acids (lactic acid and glycolic acid) and cellulose polymers, both in hydrogels, in order to produce a formulation with improved activity against Propionibacterium acnes and Staphylococcus aureus, which can potentially be used in the treatment of acne. The rheological characterisation of the hydrogels was examined using continuous shear and viscoelastic creep. The antibacterial activities of formulations were performed by the well diffusion and broth microdilution. The hydrogels formulated with only chitosan showed pseudoplastic behavior while the chitosan hydrogels with cellulose polymers presented viscoelastic properties. The antibacterial activity was proportional to AHA and chitosan concentration. It was enhanced at low pH values and with high molecular weight chitosan and did not change with the incorporation of two cellulose polymers. The antibacterial mechanism of chitosan has currently been hypothesized as being related to surface interference. The results show that chitosan - based hydrogels containing AHA and cellulose polymers are viscoelastic,indicating good applicability onto the skin, and they present bacterial activity under various experimental conditions.
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Lifestyle is directly related to the incidence of type 2 diabetes mellitus (DM-2), a risk dramatically elevated by obesity and inactivity. Several studies have verified that educational interventions can delay the onset of DM-2. Some of the interventions strategies utilized medication and diet, diet and/or physical exercise or the combination of diet and exercise, generally referred to a change in lifestyle. Despite the evidence that DM-2 can be preventive, there is still limited availability of effective prevention programs. DM-2 is considered an emerging public health problem as it is estimated that by the year of 2030 there will be about 366 million people with diabetes worldwide. DM2 remains a leading cause of cardiovascular disorders and many other complications. Our intent with this paper is to present researches and strategies (diet and physical activity interventions) that successfully improved plasma glucose control as a result of an effective lifestyle intervention program.
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Purpose: To determine the proportion of blindness and investigate the relationships between risk factors based on clinical characteristics and development of blindness in patients with primary open-angle glaucoma (POAG) treated for at least 15 years. Methods: A retrospective observational chart review was performed with 403 patients referred to a tertiary level hospital, each with a diagnosis of primary open-angle glaucoma, treated for at least 15 years. Blindness attributable to glaucoma was defined based on visual acuity and/or visual field tests. Variables considered to be possible risk factors for blindness were evaluated using odds ratio (OR), confidence interval (95% CI), and univariate and multivariate analyses. Results: Thirty-one patients became blind [13/53 (24.5%) - unilaterally and 18/53 (34%) - bilaterally] during the follow-up period of treatment (19.5 +/- 4.6 years, range 15-31 years). Multivariate statistics with regression analysis revealed that persistency on initial therapy <= 6 months was significantly associated with blindness, both unilateral (OR: 8.4; 95% CI: 1.3-56.4) and bilateral (OR: 7.2; 95% CI: 1.3-39.6). Other potential factors such as race, age, gender or number of medications were not associated with blindness. Conclusion: Blindness from primary open-angle glaucoma was not uncommon in this population of treated patients after the long follow-up period proposed. Persistence rates with the first therapy, as measured by a medical decision to change, were low. Persistence <= 6 months was statistically associated with the development of unilateral and bilateral blindness from glaucoma.
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With the increase in research on the components of Body Image, validated instruments are needed to evaluate its dimensions. The Body Change Inventory (BCI) assesses strategies used to alter body size among adolescents. The scope of this study was to describe the translation and evaluation for semantic equivalence of the BCI in the Portuguese language. The process involved the steps of (1) translation of the questionnaire to the Portuguese language; (2) back-translation to English; (3) evaluation of semantic equivalence; and (4) assessment of comprehension by professional experts and the target population. The six subscales of the instrument were translated into the Portuguese language. Language adaptations were made to render the instrument suitable for the Brazilian reality. The questions were interpreted as easily understandable by both experts and young people. The Body Change Inventory has been translated and adapted into Portuguese. Evaluation of the operational, measurement and functional equivalence are still needed.
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In developed countries, children with intrauterine growth restriction (IUGR) or born preterm (PT) tend to achieve catch-up growth. There is little information about height catch-up in developing countries and about height catch-down in both developed and developing countries. We studied the effect of IUGR and PT birth on height catch-up and catch-down growth of children from two cohorts of liveborn singletons. Data from 1,463 children was collected at birth and at school age in Ribeirao Preto (RP), a more developed city, and in Sao Luis (SL), a less developed city. A change in z-score between schoolchild height z-score and birth length z-score >= 0.67 was considered catch-up; a change in z-score <=-0.67 indicated catch-down growth. The explanatory variables were: appropriate weight for gestational age/PT birth in four categories: term children without IUGR (normal), IUGR only (term with IUGR), PT only ( preterm without IUGR) and preterm with IUGR; infant's sex; maternal parity, age, schooling and marital status; occupation of family head; family income and neonatal ponderal index (PI). The risk ratio for catch-up and catch-down was estimated by multinomial logistic regression for each city. In RP, preterms without IUGR (RR = 4.13) and thin children (PI<10th percentile, RR = 14.39) had a higher risk of catch-down; catch-up was higher among terms with IUGR (RR = 5.53), preterms with IUGR (RR = 5.36) and children born to primiparous mothers (RR = 1.83). In SL, catch-down was higher among preterms without IUGR (RR = 5.19), girls (RR = 1.52) and children from low-income families ( RR = 2.74); the lowest risk of catch-down (RR = 0.27) and the highest risk of catch-up (RR = 3.77) were observed among terms with IUGR. In both cities, terms with IUGR presented height catch-up growth whereas preterms with IUGR only had height catch-up growth in the more affluent setting. Preterms without IUGR presented height catch-down growth, suggesting that a better socioeconomic situation facilitates height catch-up and prevents height catch-down growth.
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Purpose: To investigate the rate of visual field and optic disc change in patients with distinct patterns of glaucomatous optic disc damage. Design: Prospective longitudinal study. Participants: A total of 131 patients with open-angle glaucoma with focal (n = 45), diffuse (n = 42), and sclerotic (n = 44) optic disc damage. Methods: Patients were examined every 4 months with standard automated perimetry (SAP, SITA Standard, 24-2 test, Humphrey Field Analyzer, Carl Zeiss Meditec, Dublin, CA) and confocal scanning laser tomography (CSLT, Heidelberg Retina Tomograph, Heidelberg Engineering GmbH, Heidelberg, Germany) for a period of 4 years. During this time, patients were treated according to a predefined protocol to achieve a target intraocular pressure (IOP). Rates of change were estimated by robust linear regression of visual field mean deviation (MD) and global optic disc neuroretinal rim area with follow-up time. Main Outcome Measures: Rates of change in MD and rim area. Results: Rates of visual field change in patients with focal optic disc damage (mean -0.34, standard deviation [SD] 0.69 dB/year) were faster than in patients with sclerotic (mean - 0.14, SD 0.77 dB/year) and diffuse (mean + 0.01, SD 0.37 dB/year) optic disc damage (P = 0.003, Kruskal-Wallis). Rates of optic disc change in patients with focal optic disc damage (mean - 11.70, SD 25.5 x 10(-3) mm(2)/year) were faster than in patients with diffuse (mean -9.16, SD 14.9 x 10(-3) mm(2)/year) and sclerotic (mean -0.45, SD 20.6 x 10(-3) mm(2)/year) optic disc damage, although the differences were not statistically significant (P = 0.11). Absolute IOP reduction from untreated levels was similar among the groups (P = 0.59). Conclusions: Patients with focal optic disc damage had faster rates of visual field change and a tendency toward faster rates of optic disc deterioration when compared with patients with diffuse and sclerotic optic disc damage, despite similar IOP reductions during follow-up. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2012; 119: 294-303 (C) 2012 by the American Academy of Ophthalmology.
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Groundwater has a strategic role in times of climate change mainly because aquifers can provide water for long periods, even during very long and severe drought. The reduction and/or changes on the precipitation pattern can diminish the recharge mainly in unconfined aquifer, causing available groundwater restriction. The expected impact of long-term climate changes on the Brazilian aquifers for 2050 will lead to a severe reduction in 70% of recharge in the Northeast region aquifers (comparing to 2010 values), varying from 30% to 70% in the North region. Data referring to the South and Southeast regions are more favorable, with an increase in the relative recharge values from 30% to 100%. Another expected impact is the increase in demand and the decrease in the surface water availability that will make the population turn to aquifers as its main source of water for public or private uses in many regions of the country. Thus, an integrated use of surface and groundwater must therefore be considered in the water use planning. The solution of water scarcity is based on three factors: society growth awareness, better knowledge on the characteristics of hydraulic and chemical aquifers and effective management actions.
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The general aim of this dissertation is to describe and analyse how public old-age care in Sweden has developed and changed during the last century. The study applies a provider perspective on how care has been planned and professionally carried out. A broader social policy perspective, studying old-age care at central/national as well as local/municipal level, is also developed. A special focus is directed at the large local variation in care and services for the elderly. The empirical base is comprised of official documents and other public sources, survey data from interviews with elderly recipients of public old-age care, and official statistics on publicly financed and controlled old-age care and services. Study I addresses the development of old-age care in Sweden during the twentieth century by studying an important occupation in this field – the supervisors and their professional roles, tasks and working conditions. Throughout, the roles of supervisors have followed the prevailing official policy on the proper way to provide care for elderly people in Sweden; from poor relief at the beginning of the 1900s, via a generous level of services in the 1960s and 1970s, to today’s restricted and economy-controlled mode of operation. Study II describes and compares two main forms of public old-age care in Sweden today, home help services and institutional care. The care-load found in home-based care was comparable to and sometimes even larger than in service-homes and other institutions, indicating that large care needs among elderly people in Sweden today can be met in their homes as well as in institutional settings. Studies III and IV analyse the local variation in public old-age care in Sweden. During the last decades there has been an overall decline in home help services. The coverage of home help for elderly people shows large differences between municipalities throughout this period, and the relative variation has increased. The local disparity seems to depend more on historical factors, e.g., previous coverage rates, than on the present municipal situation in levels of need or local economy and politics. In an introductory part the four papers are linked together by an outline of the demographic situation and the social policy model for old-age care in Sweden. Trends that have been apparent over time, e.g. professionalisation and market orientation, are traced and discussed. Conflicts between prevailing ideologies are analysed, in regards to for instance home-based and institution-based care, social and medical culture, and local and central levels of decision-making. ’Welfare municipality’, ‘path dependency’, and ‘decentralisation’ are suggested as a conceptual framework for describing the large and increasing local variations in old-age care. Finally, implications of the four studies with regard to old-age care policy and further research are discussed.
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The presented study carried out an analysis on rural landscape changes. In particular the study focuses on the understanding of driving forces acting on the rural built environment using a statistical spatial model implemented through GIS techniques. It is well known that the study of landscape changes is essential for a conscious decision making in land planning. From a bibliography review results a general lack of studies dealing with the modeling of rural built environment and hence a theoretical modelling approach for such purpose is needed. The advancement in technology and modernity in building construction and agriculture have gradually changed the rural built environment. In addition, the phenomenon of urbanization of a determined the construction of new volumes that occurred beside abandoned or derelict rural buildings. Consequently there are two types of transformation dynamics affecting mainly the rural built environment that can be observed: the conversion of rural buildings and the increasing of building numbers. It is the specific aim of the presented study to propose a methodology for the development of a spatial model that allows the identification of driving forces that acted on the behaviours of the building allocation. In fact one of the most concerning dynamic nowadays is related to an irrational expansion of buildings sprawl across landscape. The proposed methodology is composed by some conceptual steps that cover different aspects related to the development of a spatial model: the selection of a response variable that better describe the phenomenon under study, the identification of possible driving forces, the sampling methodology concerning the collection of data, the most suitable algorithm to be adopted in relation to statistical theory and method used, the calibration process and evaluation of the model. A different combination of factors in various parts of the territory generated favourable or less favourable conditions for the building allocation and the existence of buildings represents the evidence of such optimum. Conversely the absence of buildings expresses a combination of agents which is not suitable for building allocation. Presence or absence of buildings can be adopted as indicators of such driving conditions, since they represent the expression of the action of driving forces in the land suitability sorting process. The existence of correlation between site selection and hypothetical driving forces, evaluated by means of modeling techniques, provides an evidence of which driving forces are involved in the allocation dynamic and an insight on their level of influence into the process. GIS software by means of spatial analysis tools allows to associate the concept of presence and absence with point futures generating a point process. Presence or absence of buildings at some site locations represent the expression of these driving factors interaction. In case of presences, points represent locations of real existing buildings, conversely absences represent locations were buildings are not existent and so they are generated by a stochastic mechanism. Possible driving forces are selected and the existence of a causal relationship with building allocations is assessed through a spatial model. The adoption of empirical statistical models provides a mechanism for the explanatory variable analysis and for the identification of key driving variables behind the site selection process for new building allocation. The model developed by following the methodology is applied to a case study to test the validity of the methodology. In particular the study area for the testing of the methodology is represented by the New District of Imola characterized by a prevailing agricultural production vocation and were transformation dynamic intensively occurred. The development of the model involved the identification of predictive variables (related to geomorphologic, socio-economic, structural and infrastructural systems of landscape) capable of representing the driving forces responsible for landscape changes.. The calibration of the model is carried out referring to spatial data regarding the periurban and rural area of the study area within the 1975-2005 time period by means of Generalised linear model. The resulting output from the model fit is continuous grid surface where cells assume values ranged from 0 to 1 of probability of building occurrences along the rural and periurban area of the study area. Hence the response variable assesses the changes in the rural built environment occurred in such time interval and is correlated to the selected explanatory variables by means of a generalized linear model using logistic regression. Comparing the probability map obtained from the model to the actual rural building distribution in 2005, the interpretation capability of the model can be evaluated. The proposed model can be also applied to the interpretation of trends which occurred in other study areas, and also referring to different time intervals, depending on the availability of data. The use of suitable data in terms of time, information, and spatial resolution and the costs related to data acquisition, pre-processing, and survey are among the most critical aspects of model implementation. Future in-depth studies can focus on using the proposed model to predict short/medium-range future scenarios for the rural built environment distribution in the study area. In order to predict future scenarios it is necessary to assume that the driving forces do not change and that their levels of influence within the model are not far from those assessed for the time interval used for the calibration.
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Die Fragmentierung von Waldgebieten, der Verlust geeigneter Habitate, die Invasion exotischer Arten und globale Klimaveränderung haben auf Artengemeinschaften erhebliche Auswirkungen. Vögel dienen in vielen Fällen als Indikatorarten für Umweltveränderungen und, besonders, für Veränderungen im Zusammenhang mit globaler Erwärmung. In meiner Arbeit habe ich zuerst einen Literaturüberblick über die Auswirkungen globaler Klimaveränderung auf die Verbreitungsgebiete, den Artenreichtum und die Zusammensetzung von Vogelgemeinschaften dargestellt. Zahlreiche Untersuchungen zeigen, daß die Grenzen der Verbreitungsgebiete der meisten Vogelarten mit klimatischen Faktoren korrelieren. Verschiebungen der Verbreitungsgebiete in nördliche Richtung oder in höhere Regionen im Gebirge konnten bereits für viele temperate Vogelarten beobachtet werden. Weiterhin wurde ein zunehmender Artenreichtum besonders in nördlichen Breiten und in höheren Lagen für viele temperate Vogelgemeinschaften vorhergesagt. In trockenen Gebieten ist dagegen mit einer Abnahme des Artenreichtums zu rechnen. Im zweiten Teil meiner Arbeit habe ich untersucht, ob beobachtete Veränderungen in der Zusammensetzung europäischer Vogelgemeinschaften tatsächlich durch aktuelle Klimaveränderungen beeinflußt werden. Das Zugverhalten der Arten war dabei ein Schwerpunkt der Untersuchung, weil zu erwarten war, daß Vogelarten mit verschiedenem Zugverhalten unterschiedlich auf Klimaveränderungen reagieren. Ich habe ein Regressionsmodell genutzt, welches die räumliche Beziehung zwischen dem Anteil von Langstreckenziehern, Kurzstreckenziehern und Standvögeln in europäischen Vogelgemeinschaften und verschiedenen Klimavariablen beschreibt. Für 21 Gebiete in Europa habe ich Daten über beobachtete Veränderungen in der Struktur der Vogelgemeinschaften und isochrone Klimaveränderungen zusammengetragen. Mit Hilfe dieser Klimaveränderungen und dem räumlichen Regressionsmodell konnte ich berechnen, welche Veränderungen in den Vogelgemeinschaften aufgrund der veränderten Klimabedingungen zu erwarten wären und sie mit beobachteten Veränderungen vergleichen. Beobachtete und berechnete Veränderungen korrelierten signifikant miteinander. Die beobachteten Veränderungen konnten nicht durch räumliche Autokorrelationseffekte oder durch alternative Faktoren, wie z.B. Veränderungen in der Landnutzung, erklärt werden. Im dritten Teil der Arbeit untersuchte ich für eine mitteleuropäische Vogelgemeinschaft welchen Einfluß Habitatveränderungen, die Invasion exotischer Arten und die Klimaveränderung auf Veränderungen der Häufigkeit und Verbreitungsgröße der 159 Vogelarten am Bodensee zwischen 1980-1981 und 2000-2002 hatten. Dabei konnte gezeigt werden, daß Veränderungen in der regionalen Abundanz sowohl durch Habitatveränderungen als auch durch Klimavänderungen hervorgerufen wurden. Exotische Arten schienen in dieser Zeit keinen bedeutenden Einfluß zu haben. Besonders bei Agrarlandarten, Arten mit nördlicheren Verbreitungsgebieten und bei Langstreckenziehern konnten signifikante Abnahmen in der Abundanz beobachtet werden. Vor allem die anhaltenden negativen Bestandsveränderungen bei Langstreckenziehern und die in den letzten zehn Jahren aufgetretenen Abnahmen nördlicher verbreiteter Vogelarten deuten darauf hin, daß die Klimaveränderung aktuell als der größte Einfluß für Vögel in Europa angesehen werden muß. Insgesamt zeigen die Ergebnisse dieser Arbeit, daß sich der anhaltende Druck auf die Umwelt in erster Linie durch Habitat- und Klimaveränderungen manifestiert.
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Der Globale Wandel ist im Begriff, den Tourismus zu verändern. Die Wechselwirkung von Tourismus und Klimawandel sind beidseitiger Art. Die vorliegende Arbeit zeigt Möglichkeiten der Adaption und einen wandelbaren Fremdenverkehr. Eine Übersicht der gängigen Tourismusmodelle stellt den Stand der Forschung dar. Der Fremdenverkehr ist durch drei Faktoren massiv geprägt: Die Nachfrage und Motivation, die Reisemittler und Veranstalter sowie das Destinationsangebot. Bei der Motivation wirken Motiv und Anreiz Motivationspsychologisch betrachtet auf die Reiseentscheidung deren Grundlage verarbeitete Informationen sind. Reisemittler und Veranstalter haben einen großen Einfluss auf Entscheidungsprozesse. Neue IuK Technologien haben deren Arbeit grundlegend verändert. Das Tourismusangebot wird stark durch die naturräumlichen Gegebenheiten sowie das politische System bestimmt. Überlebenswichtig für die Destination ist die evolutionstheoretisch etrachtete Fitnessmaximierung also Adaption und Wandel, um sich an geänderte Rahmenbedingungen anpassen zu können. Gerade im Bereich des Klimawandels müssen Maßnahmen ergriffen werden. Aber auch die Marktsättigung gerade in Verbindung mit der aktuellen Finanzkrise wirkt besonders schwer auf die Destination. Eine hohes Innovationsvermögen, Trendscanning und der Zusammenschluss in flexiblen Netzwerkclustern können einen Kundenmehrwert erzeugen. Die Fitnessmaximierung ist somit Überlebensziel der Destination und führt zur Kundenzufriedenheit die im Sättigungsmarkt alleinig Wachstum generieren kann.
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Studies on soil organic carbon (SOC) sequestration in perennial energy crops are available for North-Central Europe, while there is insufficient information for Southern Europe. This research was conducted in the Po Valley, a Mediterranean-temperate zone characterised by low SOC levels, due to intensive management. The aim was to assess the factors influencing SOC sequestration and its distribution through depth and within soil fractions, after a 9-year old conversion from two annual systems to Miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax). The 13C natural abundance was used to evaluate the amount of SOC in annual and perennial species, and determine the percentage of carbon derived from perennial crops. SOC was significantly higher under perennial species, especially in the topsoil (0-0.15 m). After 9 years, the amount of C derived from Miscanthus was 18.7 Mg ha-1, mostly stored at 0-0.15 m, whereas the amount of C derived from giant reed was 34.7 Mg ha-1, evenly distributed through layers. Physical soil fractionation was combined with 13C abundance analysis. C derived from perennial crops was mainly found in macroaggregates. Under giant reed, more newly derived-carbon was stored in microaggregates and mineral fraction than under Miscanthus. A molecular approach based on denaturing gradient gel electrophoresis (DGGE) allowed to evaluate changes on microbial community, after the introduction of perennial crops. Functional aspects were investigated by determining relevant soil enzymes (β-glucosidase, urease, alkaline phosphatase). Perennial crops positively stimulated these enzymes, especially in the topsoil. DGGE profiles revealed that community richness was higher in perennial crops; Shannon index of diversity was influenced only by depth. In conclusion, Miscanthus and giant reed represent a sustainable choice for the recovery of soils exhausted by intensive management, also in Mediterranean conditions and this is relevant mainly because this geographical area is notoriously characterised by a rapid turnover of SOC.