828 research outputs found

    Understanding deforestation lock-in: Insights from Land Reform settlements in the Brazilian Amazon

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    Cropland and pasture expansion continues to erase natural ecosystems at a staggering speed globally, notably in the tropics. Conventional policy approaches, usually focused on a particular land-use change driver (e.g., specific commodities) or individual regulations (e.g., the Amazon Soy Moratorium), have consistently failed to achieve sufficient or sustained results. The swift reversal of Brazil’s earlier success in reducing Amazon deforestation – now again accelerated – offers perhaps the most sobering illustration of that. Therefore, this article draws from scholarship on sustainability transitions to propose a more comprehensive systems view of unsustainable land-use patterns. We examine persistent tropical deforestation as a case of “lock-in,” using a transitions lens, and explore its constitutive elements. As a case study, we analyze the situation of Land Reform settlements in the Brazilian Amazon, where as much as one-third of that biome’s deforestation takes place. While subject to some specific factors, those places are also enmeshed in a broader setting that is common across the Brazilian Amazon’s deforestation frontier (e.g., infrastructure conditions, market demands, and sociocultural norms). Drawing from document analysis of Brazilian policies and fieldwork in three Land Reform settlements in Pará State, we expose multiple forms of techno-economic, institutional, and socio-cognitive lock-in that together drive deforestation systemically in those settlements. These drivers form a strongly consolidated socio-technical regime around large-scale agriculture that includes material and immaterial factors (e.g., cultural ones), a regime that not only resists change but also – like a vortex – pulls others into it. Escaping deforestation lock-in may thus require outside forces to help local actors destabilize and eventually replace this unsustainable land-use regime. International zero-deforestation efforts offer a starting point, but a transition requires moving beyond piecemeal, incremental change or end-of-pipe approaches and toward concerted, strategic action that addresses multiple of those regime elements in a coordinated way to replace it as a system. We argue that understanding deforestation lock-in is vital for tackling its worrisome persistence and that sustainability transitions theory offers an illuminating, but still underutilized, framework to analyze and eventually overcome unsustainable land use

    Social-ecological trends: managing the vulnerability of coastal fishing communities

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    The loss of biodiversity, including the collapse of fish stocks, affects the vulnerability of social-ecological systems (SESs) and threatens local livelihoods. Incorporating community-centered indicators and SES drivers and exposures of change into coastal management can help anticipate and mitigate human and/or coastal vulnerability. We have proposed a new index to measure the social-ecological vulnerability of coastal fishing communities (Index of Coastal Vulnerability [ICV]) based on species, ecosystem, and social indicators. The ICV varies from 0 (no vulnerability) to 1 (very high vulnerability) and is composed of 3 components: species vulnerability, i.e., fish biological traits; ecosystem vulnerability, i.e., environmental indicators of ecosystem health; and adaptive capacity, i.e., human ability to cope with changes. We tested the ICV of Brazil’s 17 coastal states. The average ICV for the Brazilian coast was 0.77, and variation was low among states. More than half of the coastal states revealed very high vulnerability (> 0.8). The ecosystem vulnerability values were worse than the adaptive capacity and species vulnerability values, and the North and Northeast regions were revealed to be vulnerable hot spots. Additionally, we investigated how the ICV related to specific anthropogenic risks, i.e., fish landing richness, fishery instability, market, coastal extension, and coastal population, and found that states with fewer species landings and higher coastal populations presented higher ICVs. At a time when human impacts are overtaking natural processes, understanding how these impacts lead to coastal vulnerability can help improve conservation policies. For this case study, we suggest both fisheries management measures and restoration of sensitive habitats to protect species and decrease vulnerability. The integrated evaluation developed here could be used as a baseline for coastal monitoring and conservation planning and be applied to coastal regions in which governments evaluate both social and biological aspects.Postprint2,51

    A social-ecological approach to estimate fisher resilience: a case study from Brazil

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    Social-ecological systems (SESs), such as fishing communities, are human and biophysical subsystems that are intrinsically connected to one another and strongly depend on natural resources. That is why these human groups are usually the first to feel the effects of policies concerning fisheries and ocean governance and the most affected by them. These policies can potentially build or erode social-ecological resilience (SER), especially if they are coupled with environmental changes. SER assessments offer a valuable tool to identify human-nature linkages, and the implications and feedbacks in SESs when facing human-induced or natural changes. We created a SER index by combining interviews with fishers with environmental datasets on a fine scale that has never been presented for the Brazilian coast. This scale was then tested in marine protected areas that allow sustainable use. Our approach estimated SER from information on fisheries ecosystem services and adaptive capacity at the local scale, considering the individual and community levels. We synthesized blocks of critical indicators of an individual or community’s ability to build and maintain resilience in SESs, such as flexibility, ability to learn, ability to organize, assets, social capital, and ecological characteristics. We identified that fishers’ ability to learn and to organize, as well as the biological sensitivity of an ecosystem are determinant to enhancing SER in the studied coastal communities. A Bayesian model also showed that the fishers’ SER was related to socioeconomic factors, thereby indicating that older fishers, fishers who consistently catch more fish, and fishers with a higher reliance on fishing for their income presented lower index values. By knowing the variables that influence the ability of fishers to cope with changes to their SESs, we can devise smarter management approaches that may include compensatory mechanisms for more fragile fishers. Our findings can also inform decision making about where fisheries management strategies are likely to be more participative and effective in order to minimize the social impacts of policy decisions and increase SER in coastal communities.Postprint2,51

    Astronomia no Infravermelho de Estrelas Variáveis

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    Este trabalho tem por objetivo fazer um estudo fotométrico de estrelas variáveis utilizando dados fotométricos do projeto 2 Micron All Sky Survey. Foram analisados dados de fotometria infravermelho nas bandas JHKs de cinco tipos de estrelas variáveis: Wolf Rayet, RS Canum Venaticorum, Sistemas Binários de Raios-X, Fontes Super Soft e Estrelas Simbióticas. As materializações de diagramas Cor-Cor permitiram um estudo das propriedades fotométricas infravermelho intrínsecas destas fontes, e assim obteve-se uma ferramenta para identificação de alvos para estudos mais detalhados a serem realizados posteriormente com telescópios de maior porte

    Size matters: fishing less and yielding more in smaller-scale fisheries

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    Several factors influence catches and the sustainability of fisheries, and such factors might be different depending on the scale on which fisheries work. We investigated the existence of possible subdivisions within small-scale fisheries (SSF) themselves, regarding their economic performance and relative social and environmental impacts to understand which categories of these two types of fleets are best positioned to support sustainability. By doing so, we investigated if it is a good strategy for SSF to aim to grow towards larger scales. We obtained economic and ecological data from landing samplings and information on technological efficiency of this fleet, using a northeastern Brazilian state as a case study. We defined a cut-off point to separate the SSF into two categories of boats, according to their size and gear. We compared their cpue and the factors affecting it within each category; we also compared economic (number of boats, number of landings, jobs, gears, catch, travel time and total time of the fishery, revenues, costs, profits, revenue per unit of effort, and profit per unit of effort) and ecological factors (vulnerability of species caught) between the two categories. We found that small boats spent less time fishing and employed comparatively more people per landed value and catch. The cpue and profits of small boats were also higher. Both large and small boats exploit species with the same overall vulnerability. Therefore, being smaller, even within the SSF category, seems to be a more advantageous social and economic strategy for guaranteeing higher catches and more employment opportunities per catch. These findings need to be taken into account when defining new policies, such as the distribution of subsidies that support or not the sustainable use of fishery resources

    Massive lower gastrointestinal bleeding from idiopathic ileocolonic varix: report of a case

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    Dis Colon Rectum. 2006 Apr;49(4):524-6. Massive lower gastrointestinal bleeding from idiopathic ileocolonic varix: report of a case. Lopes LM, Ramada JM, Certo MG, Pereira PR, Soares JM, Ribeiro M, Areias J, Pinho C. SourceGastroenterology Department, Hospital Geral Santo António, Porto, Portugal. [email protected] Abstract Idiopathic varices of the entire colon are very rare. We report on a 64-year-old patient with massive lower gastrointestinal hemorrhage from an extensive ileocolonic varix. Diagnosis was established by colonoscopy. The patient underwent an emergency ileocolectomy with satisfactory results. This rare case shows the importance of colonoscopy in the evaluation of patients with lower gastrointestinal hemorrhage and reminds us that sometimes the diagnosis is not what we expect. Recognition of this abnormality is important because varices may be the cause of massive lower gastrointestinal hemorrhage. PMID: 16395635 [PubMed - indexed for MEDLINE

    Sphingomyelin is synthesized at the plasma membrane of oligodendrocytes and by purified myelin membranes: a study with fluorescent- and radio-labelled ceramide analogues

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    AbstractIn most cell types sphingomyelin is synthesized predominantly in the cis-medial compartments of the Golgi stacks whereas the contribution of the plasma membrane is much lower. The aim of this study was to assess the contribution of both compartments to the synthesis of sphingomyelin in myelinating cells. Therefore, oligodendrocytes from rat spinal cord were incubated in culture with fluorescently- or radiolabelled ceramides, and the effects of a block in the vesicular flow (monensin, brefeldin A, low temperature) on surface synthesis of sphingomyelin were evaluated. The results indicate that ≈50% of the sphingomyelin synthase is present at the plasma and myelin membranes of oligodendrocytes

    Inclusion Complex Of S(-) Bupivacaine And 2-hydroxypropyl- β-cyclodextrin: Study Of Morphology And Cytotoxicity

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    Local anesthetics (LA) belong to a class of pharmacological compounds that attenuate or eliminate pain by binding to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nerve impulse. S (-) bupivacaine (S(-) bvc) is a local anesthetic of amino-amide type, widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. This article focuses on the characterization of an inclusion complex of S(-) bvc in 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). Differential scanning calorimetry, scanning electron microscopy and X-Ray diffraction analysis showed structural changes in the complex. In preliminary toxicity studies, the cell viability tests revealed that the inclusion complex decreased the toxic effect (p<0.001) produced by S(-) bvc. These results suggest that the S(-) bvc:HP-β-CD inclusion complex represents a promising agent for the treatment of regional pain.273207212Araújo, D.R., Cereda, C.M., Brunetto, G.B., Pinto, L.M.A., Santana, M.H., de Paula, E., Encapsulation of mepivacaine prolongs the analgesia provided by sciatic nerve blockade in mice (2004) Can J Anaesth, 51, pp. 566-572Araújo, D.R., Fraceto, L.F., Braga, A.F.A., de Paula, E., Drug-delivery systems for racemic bupivacaine (S50-R50) and bupivacaine enantiomeric mixture (S75-R25):cyclodextrins complexation effects on sciatic nerve blockade in mice (2005) Rev Bras Anestesiol, 55, pp. 316-328Araújo, D.R., Moraes, C.M., Fraceto, L.F., Braga, A.F.A., de Paula, E., Cyclodextrin-bupivacaine enantiomeric mixture (S75-R25) inclusion complex and intrathecal anesthesia in rats (2006) Rev Bras Anestesiol, 56, pp. 495-506Bibby, D., Davies, N.M., Tueker, I.G., Mechanisms by which cyclodextrins modify drug release from polymeric drug delivery systems (2000) Int J Pharm, 197, pp. 1-11Covino, B.G., Vassalo, H.G., (1976) Local anesthetics: Mechanisms of action and clinical use, , New York: Grune and Stratton;, 255pFoster, R.H., Markham, A., Levobupivacaine. A review of its pharmacology and use as a local anaesthetic (2000) Drugs, 59, pp. 551-579Grant, G.J., Bansinath, M., Liposomal delivery systems for local anesthetics (2001) Reg Anesth Pain Med, 26, pp. 61-63Gristwood, R.W., Cardiac and CNS toxicity of levobupivacaine: Strengths of evidence for advantage over bupivacaine (2002) Drug Saf, 25, pp. 153-163Hirayama, F., Uekama, K., Cyclodextrin-based controlled drug release system (1999) Adv Drug Deliv Rev, 36, pp. 125-141Huang, Y.F., Pryor, M.E., Mather, L.E., Veering, B.T., Cardiovascular and central nervous system effects of intravenous S-bupivacaine and bupivacaine in sheep (1998) Anesth Analg, 86, pp. 797-804Jong, R.H., (1994) Local anesthetics, , Springfield: CC. Thomas;, 325pKohata, S., Jyodi, K., Ohyoshi, A., Thermal decomposition of cyclodextrins (α -, β-, γ, and modified β-CyD) and of metal-(β-CyD) complex in the solid phase (1993) Thermochim Acta, 217, pp. 187-198Loftsson, T., Brewster, M.E., Pharmaceutical application of Cyclodextrin. 1. Drug solubilization and stabilization (1996) J Pharm Sci, 85, pp. 1017-1025Loukas, Y.L., Vraka, V., Gregoriadis, G., Novel non-acidic formulations of haloperidol complexed with beta-cyclodextrin derivatives (1997) J Pharm Biomed Anal, 16, pp. 263-268Mather, L.E., McCall, P., McNicol, P.L., Bupivacaine enantiomer pharmacokinetics after intercostal neural blockade in liver transplant patients (1995) Anesth Analg, 80, pp. 328-335Michaud, M., Icart, S., Determination of the substitution of hydroxypropylbetadex using fourier transform infrared spectrophotometry (2001) PharmEuropa, 13, pp. 714-716Naidu, N.B., Chowdary, K.P.R., Murthy, K.V.R., Satyanarayana, V., Hayman, A.R., Becket, G., Physicochemical characterization and dissolution properties of meloxicam-cyclodextrin binary systems (2004) J Pharm Biomed Anal, 35, pp. 75-86Pinto, L.M.A., Fraceto, L.F., Santana, M.H.A., Pertinhez, T.A., Oyama, S., de Paula, E., Physico-chemical characterization of benzocaine-β-cyclodextrin inclusion complexes (2005) J Pharm Biomed Anal, 39, pp. 956-963Ren, X., Xue, Y., Liu, J., Zhang, K., Zheng, J., Lou, G., Gou, C., Shen, J., A novel cyclodextrin-deri ved tellurium compound with glutathione peroxidase (2002) Chembiochem, 3, pp. 363-365Rose, J.S., Neal, J.M., Kopacz, D.J., Extended-duration analgesia: Update on microspheres and liposomes (2005) Reg Anesth Pain Med, 30, pp. 275-285Strichartz, G.R., Ritchie, J.M., (1987) Local anesthetics: Handbook of experimental pharmacology, , Berlin: Springer-Verlag;, 445pThompson, D.O., Cyclodextrin-enabling excipients: Their present and future use in pharmaceuticals (1997) Crit Rev Ther Drug Carrier Syst, 14, pp. 1-10
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