566 research outputs found

    Nut production in Bertholletia excelsa across a logged forest mosaic: implications for multiple forest use

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    Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù

    Development of forest structure and leaf area in secondary forests regenerating on abandoned pastures in Central Amazonia

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    The area of secondary forest (SF) regenerating from pastures is increasing in the Amazon basin; however, the return of forest and canopy structure following abandonment is not well understood. This study examined the development of leaf area index (LAI), canopy cover, aboveground biomass, stem density, diameter at breast height (DBH), and basal area ( BA) by growth form and diameter class for 10 SFs regenerating from abandoned pastures. Biomass accrual was tree dominated, constituting >= 94% of the total measured biomass in all forests abandoned >= 4 to 6 yr. Vine biomass increased with forest age, but its relative contribution to total biomass decreased with time. The forests were dominated by the tree Vismia spp. (> 50%). Tree stem density peaked after 6 to 8 yr ( 10 320 stems per hectare) before declining by 42% in the 12- to 14-yr-old SFs. Small-diameter tree stems in the 1-5-cm size class composed > 58% of the total stems for all forests. After 12 to 14 yr, there was no significant leaf area below 150-cm height. Leaf area return (LAI = 3.2 after 12 to 14 yr) relative to biomass was slower than literature-reported recovery following slash-and-burn, where LAI can reach primary forest levels ( LAI = 4 - 6) in 5 yr. After 12 to 14 yr, the colonizing vegetation returned some components of forest structure to values reported for primary forest. Basal area and LAI were 50% - 60%, canopy cover and stem density were nearly 100%, and the rapid tree-dominated biomass accrual was 25% - 50% of values reported for primary forest. Biomass accumulation may reach an asymptote earlier than expected because of even-aged, monospecific, untiered stand structure. The very slow leaf area accumulation relative to biomass and to reported values for recovery following slash-and-burn indicates a different canopy development pathway that warrants further investigation of causes ( e. g., nutrient limitations, competition) and effects on processes such as evapotranspiration and soil water uptake, which would influence long-term recovery rates and have regional implications

    Forecasting Tunisian type 2 diabetes prevalence to 2027: validation of a simple model.

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    BACKGROUND: Most projections of type 2 diabetes (T2D) prevalence are simply based on demographic change (i.e. ageing). We developed a model to predict future trends in T2D prevalence in Tunisia, explicitly taking into account trends in major risk factors (obesity and smoking). This could improve assessment of policy options for prevention and health service planning. METHODS: The IMPACT T2D model uses a Markov approach to integrate population, obesity and smoking trends to estimate future T2D prevalence. We developed a model for the Tunisian population from 1997 to 2027, and validated the model outputs by comparing with a subsequent T2D prevalence survey conducted in 2005. RESULTS: The model estimated that the prevalence of T2D among Tunisians aged over 25 years was 12.0% in 1997 (95% confidence intervals 9.6%-14.4%), increasing to 15.1% (12.5%-17.4%) in 2005. Between 1997 and 2005, observed prevalence in men increased from 13.5% to 16.1% and in women from 12.9% to 14.1%. The model forecast for a dramatic rise in prevalence by 2027 (26.6% overall, 28.6% in men and 24.7% in women). However, if obesity prevalence declined by 20% in the 10 years from 2013, and if smoking decreased by 20% over 10 years from 2009, a 3.3% reduction in T2D prevalence could be achieved in 2027 (2.5% in men and 4.1% in women). CONCLUSIONS: This innovative model provides a reasonably close estimate of T2D prevalence for Tunisia over the 1997-2027 period. Diabetes burden is now a significant public health challenge. Our model predicts that this burden will increase significantly in the next two decades. Tackling obesity, smoking and other T2D risk factors thus needs urgent action. Tunisian decision makers have therefore defined two strategies: obesity reduction and tobacco control. Responses will be evaluated in future population surveys

    Food for thought: The underutilized potential of tropical tree-sources foods for 21st century sustainable food systems

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    1. The global food system is causing large-scale environmental degradation and is a major contributor to climate change. Its low diversity and failure to produce enough fruits and vegetables is contributing to a global health crisis. 2. The extraordinary diversity of tropical tree species is increasingly recognized to be vital to planetary health and especially important for supporting climate change mitigation. However, they are poorly integrated into food systems. Tropical tree diversity offers the potential for sustainable production of many foods, providing livelihood benefits and multiple ecosystem services including improved human nutrition. 3. First, we present an overview of these environmental, nutritional and livelihood benefits and show that tree-sourced foods provide important contributions to critical fruit and micronutrient (vitamin A and C) intake in rural populations based on data from sites in seven countries. 4. Then, we discuss several risks and limitations that must be taken into account when scaling-up tropical tree-based food production, including the importance of production system diversity and risks associated with supply to the global markets. 5. We conclude by discussing several interventions addressing technical, financial, political and consumer behaviour barriers, with potential to increase the consumption and production of tropical tree-sourced foods, to catalyse a transition towards more sustainable global food systems

    Evaluation of the clinical and cost effectiveness of intermediate care clinics for diabetes (ICCD): A multicentre cluster randomised controlled trial

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    Background Configuring high quality care for the rapidly increasing number of people with type 2 diabetes (T2D) is a major challenge worldwide for both providers and commissioners. In the UK, about two thirds of people with T2D are managed entirely in primary care, with wide variation in management strategies and achievement of targets. Pay for performance, introduced in 2004, initially resulted in improvements but disparities exist in ethnic minorities and the improvements are levelling off. Community based, intermediate care clinics for diabetes (ICCDs) were considered one solution and are functioning across the UK. However, there is no randomised trial evidence for the effectiveness of such clinics. Trial Design, Methods and Findings This is a cluster-randomised trial, involving 3 primary care trusts, with 49 general practices randomised to usual care (n = 25) or intervention (ICCDs; n = 24). All eligible adult patients with T2D were invited; 1997 were recruited and 1280 followed-up after 18-months intervention. Primary outcome: achievement of all three of the NICE targets [(HbA1c≤7.0%/53 mmol/mol; Blood Pressure <140/80 mmHg; cholesterol <154 mg/dl (4 mmol/l)]. Primary outcome was achieved in 14.3% in the intervention arm vs. 9.3% in the control arm (p = 0.059 after adjustment for covariates). The odds ratio (95% CI) for achieving primary outcome in the intervention group was 1.56 (0.98, 2.49). Primary care and community clinic costs were significantly higher in the intervention group, but there were no significant differences in hospital costs or overall healthcare costs. An incremental cost-effectiveness ratio (ICER) of +£7,778 per QALY gained, indicated ICCD was marginally more expensive at producing health gain. Conclusions Intermediate care clinics can contribute to improving target achievement in patients with diabetes. Further work is needed to investigate the optimal scale and organisational structure of ICCD services and whether, over time, their role may change as skill levels in primary care increase. Trial Registration ClinicalTrials.gov NCT00945204; National Research Register (NRR) M0014178167.National Institute of Health Research Project number: SDO/110/2005. Initial service for support costs was provided by Department of health.NHS Leicester City, Thames Valley Diabetes Research Network (TVDRN), West Midlands South Comprehensive Local Research Network (CLRN), Primary Care Research Network (PCRN) and DIERT charity provided additional support for the successful completion of the study

    Trends in food supply, diet, and the risk of non-communicable diseases in three Small Island Developing States: implications for policy and research

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    IntroductionSmall island developing states (SIDS) are a diverse group of coastal and tropical island countries primarily located in the Caribbean and Pacific. SIDS share unique social, economic, and environmental vulnerabilities, high dependency on food imports, and susceptibility to inadequate, unhealthy diets, with high burdens of two or more types of malnutrition. Our objective was to examine trends in food availability, imports, local production, and risks of non-communicable diseases (NCDs) in three SIDS: Haiti, Saint Vincent and the Grenadines (SVG) and Fiji.MethodsData on food availability, imports, exports, and production was extracted from the Food and Agriculture Organization Database (FAOSTAT), and on overweight, obesity and diabetes prevalence from the NCD Risk Factor Collaboration database (NCD-RisC) from 1980 to 2018. Data were collated, graphed, and used to calculate import dependency ratios (IDRs) using Excel and R software.ResultsBetween 1980 and 2018, the availability of calories per capita per day has risen in Fiji and SVG by over 500, to around 3000. In Haiti, the increase is around 200, to a level of 2,200 in 2018, and in all three settings, &gt; 10% of calories in 2018 came from sugar. In Fiji and Haiti, the availability of fruit and vegetables is &lt;400 g per person per day (the minimum intake recommended by WHO). Between 1980 and 2010, both Fiji and SVG experienced high IDRs: around 80% (Fiji) and 65% (SVG). In Haiti, IDR has more than doubled since 1980, to around 30%. The prevalence of obesity (BMI &gt; 30 Kg/m2) has increased since 1980 (by 126% to 800%) and is substantially higher in women. In the most recent data for Fiji, an estimated 35% of women are obese (24% men); in SVG, 30% women (15% men); and in Haiti, 26% women (15% men).ConclusionThe increase in per capita availability of calories, which has taken place since 1980, is concurrent with an increase in IDR, a loss of local food, and increases in obesity prevalence. These findings highlight the importance of further research to understand the drivers of food supply transformations, and to influence improving nutrition, through production, availability, and consumption of nutritious local foods
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