212 research outputs found
Global Biofuel Expansion and the Demand for Brazilian Land: Intensification versus Expansion
We use a spatially disaggregated model of Brazilian agriculture to assess the implications of global biofuel expansion on Brazilian land usage at the regional level. This Brazilian model is part of the FAPRI agricultural modeling system, a multimarket, multi-commodity international agricultural model, used to quantify the emergence of biofuels and to analyze the impact of biofuel expansion and policies on both Brazilian and world agriculture. We evaluate two scenarios in which we introduce a 25% exogenous increase in the global demand for ethanol and one scenario in which we increase global ethanol demand by 50%. We then analyze the impact of these increases in terms of land-use change and commodity price changes particularly in Brazil. In the first scenario, we assume that the enforcement of the land-use reserve in Brazil remains at historically observed levels, and that abundant additional land can be readily incorporated into production. The second scenario involves implementing the same exogenous biofuel demand shock but with a different responsiveness in area expansion to price signals in Brazil, reflecting varying plausible assumptions on land availability for agricultural expansion. The third scenario, which is similar to the first scenario but with a larger increase in global ethanol demand, is run to check whether increasing volume of ethanol requires the incorporation of additional quantities of land per unit of ethanol. We find that, within Brazil, the expansion occurs mostly in the Southeast region. Additionally, total sugarcane area expansion in Brazil is higher than the increase in overall area used for agriculture. This implies that part of the sugarcane expansion displaced other crops and pasture that is not replaced, which suggests some intensification in land use. The lower land expansion elasticities in the second scenario result in a smaller expansion of area used for agricultural activities. A higher proportion of the expansion in sugarcane area occurs at the expense of pasture area, which implied land intensification of beef production. This explains the small change in commodity prices observed between the first and second scenarios. These results suggest that reducing the overall responsiveness of Brazilian agriculture may limit the land-use changes brought about by biofuel expansion, which would in turn reduce its environmental impacts in terms of land expansion. Additionally, the impacts on food prices are limited because of the ability of local producers to increase the intensity of land use in both crop (by double cropping and raising yields) and livestock production (by increasing the number of heads of cattle per hectare of pasture or stocking rate) releases area that can be used for crops. In scenario three, we find that larger ethanol volumes did not require more land per unit of ethanol. Doubling the demand for ethanol does not change the results, which indicates that the limit for intensification is beyond the 50% expansion assumed in Scenario 3. In this range, the same amount of land is incorporated into production per additional unit of ethanol.Biofuels, Brazil, land use, Land Economics/Use,
Sensitivity of Carbon Emission Estimates from Indirect Land-Use Change
We analyze the sensitivity of greenhouse gas (GHG) emissions from land-use change to modifications in assumptions concerning crop area, yield, and deforestation. For this purpose, we run a modified version of the Center for Agricultural and Rural Development (CARD) Agricultural Outlook Model, which was used previously to assess the impacts of energy price increases and biofuel policy changes on land conversion. To calculate the GHG implications of agricultural activity, we use GreenAgSiM, a model developed to evaluate emissions from land conversion and agricultural production. Both models are applied to scenarios that lead to higher US ethanol production. The results are contrasted with the findings of Searchinger et al., and we explain the role of model assumptions to elucidate the differences. We find that the payback period of corn ethanol’s carbon debt is sensitive to assumptions concerning land conversion and yield growth and can range from 31 to 180 years.biofuel, crop yield, greenhouse gas emissions, indirect land-use change.
Potential Nutrigenomic Approaches to Reduce the High Incidence of Obesity in Qatar
Obesity prevalence has been growing exponentially over the last few decades, with a high impact in high-income countries, like Qatar. Several approaches are attempting to understand the causes of this phenomenon however more important is what to do to reverse the trends. Obesity is widely studied, mostly in Europe and the Unites States, and a number of studies have demonstrate the role of specific gene patterns, transcriptome and proteome pathways, and gut microbiome strains. The Omics sciences have a great potential to investigate the determinants of non-communicable diseases, such as obesity. Nutritional genomics sciences apply all the Omics approaches to address nutrition-related diseases, investigating the interaction between genes and diet. To date, few data are available from nutrigenomic studies conducted in Middle East and particularly in Qatar to help the design of targeted
interventions. The high incidence of obesity and the peculiar genetic make-up of the Qatari population provide opportunities for exploring nutrigenomic approaches to help addressing the problem
Long-Term and Global Tradeoffs between Bio-Energy, Feed, and Food
Projections of U.S. ethanol production and its impacts on planted acreage, crop prices, livestock production and prices, trade, and retail food costs are presented under the assumption that current tax credits and trade policies are maintained. The projections were made using a multi-product, multi-country deterministic partial equilibrium model. The impacts of higher oil prices, a drought combined with an ethanol mandate, and removal of land from the Conservation Reserve Program (CRP) relative to baseline projections are also presented. The results indicate that expanded U.S. ethanol production will cause long-run crop prices to increase. In response to higher feed costs, livestock farmgate prices will increase enough to cover the feed cost increases. Retail meat, egg, and dairy prices will also increase. If oil prices are permanently $10-per-barrel higher than assumed in the baseline projections, U.S. ethanol will expand significantly. The magnitude of the expansion will depend on the future makeup of the U.S. automobile fleet. If sufficient demand for E-85 from flex-fuel vehicles is available, corn-based ethanol production is projected to increase to over 30 billion gallons per year with the higher oil prices. The direct effect of higher feed costs is that U.S. food prices would increase by a minimum of 1.1% over baseline levels. Results of a model of a 1988-type drought combined with a large mandate for continued ethanol production show sharply higher crop prices, a drop in livestock production, and higher food prices. Corn exports would drop significantly, and feed costs would rise. Wheat feed use would rise sharply. Taking additional land out of the CRP would lower crop prices in the short run. But because long-run corn prices are determined by ethanol prices and not by corn acreage, the long-run impacts on commodity prices and food prices of a smaller CRP are modest. Cellulosic ethanol from switchgrass and biodiesel from soybeans do not become economically viable in the Corn Belt under any of the scenarios. This is so because high energy costs that increase the prices of biodiesel and switchgrass ethanol also increase the price of corn-based ethanol. So long as producers can choose between soybeans for biodiesel, switchgrass for ethanol, and corn for ethanol, they will choose to grow corn. Cellulosic ethanol from corn stover does not enter into any scenario because of the high cost of collecting and transporting corn stover over the large distances required to supply a commercial-sized ethanol facility.biofuels, corn acreage, crop prices, ethanol production, food prices, Resource /Energy Economics and Policy,
Preparation, characterization and antibacterial effects of eco-friendly gold nanorods
Purpose: To synthesize and characterize eco-friendly gold nanorods (Au-NRs) and to assess their effects against two bacterial strains.Methods: Synthesis of eco-friendly gold nanorods was done from an aqueous solution of chloroauric acid and cetyltrimethylammonium bromide by mixing Olea europaea fruit and Acacia nilotica husk extracts with the latter as a reducing agent. The synthesis was monitored by ultraviolet–visible (UV) spectrophotmetry and a zetasizer, while the morphology of the resulting nanorods was assessed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled with an energy-dispersive spectrophotometer (EDS). The effect of the prepared eco-nanorods on growth of Escherichia coli and Staphylococcus aureus bacteria were investigated by agar diffusion method.Results: The synthesized Au-NRs were mostly rod-shaped, with mean size of 96 nm. They exhibited a potent antibacterial activity against Gram-positive and Gram-negative microorganisms (Escherichia coli and Staphylococcus aureus).Conclusion: The findings suggest that the nanoformulation of the biomaterial mix of Olea europaea fruit and Acacia nilotica husk extracts is a cost-effective, eco-friendly, and non-toxic synthesis of Au- NRs which has therpeautic potential.Keywords: Olea europaea, Acacia nilotica, Gold nanorods, Eco-friendly synthesis, Gram-positive and Gram-negative microorganism
Biofuel Expansion, Fertilizer Use, and GHG Emissions: Unintended Consequences of Mitigation Policies
Increased biofuel production has been associated with direct and indirect land-use change, changes in land management practices, and increased application of fertilizers and pesticides. This has resulted in negative environmental consequences in terms of increased carbon emissions, water quality, pollution, and sediment loads, which may offset the pursued environmental benefits of biofuels. This study analyzes two distinct policies aimed at mitigating the negative environmental impacts of increased agricultural production due to biofuel expansion. The first scenario is a fertilizer tax, which results in an increase in the US nitrogen fertilizer price, and the second is a policy-driven reversion of US cropland into forestland (afforestation). Results show that taxing fertilizer reduces US production of nitrogen-intensive crops, but this is partially offset by higher fertilizer use in other countries responding to higher crop prices. In the afforestation scenario, crop production shifts from high-yielding land in the United States to low-yielding land in the rest of the world. Important policy implications are that domestic policy changes implemented by a large producer like the United States can have fairly significant impacts on the aggregate world commodity markets. Also, the law of unintended consequences results in an inadvertent increase in global greenhouse gas emissions
Endocrine Disruptors and Obesity: An Examination of Selected Persistent Organic Pollutants in the NHANES 1999–2002 Data
Recent evidence suggests that endocrine disrupting chemicals (EDCs) may cause perturbations in endogenous hormonal regulation that predispose to weight gain. Using data from NHANES (1999–2002), we investigated the association between body mass index (BMI), waist circumference (WC) and selected persistent organic pollutants (POPs) via multiple linear regressions. Consistent interaction was found between gender, ln oxychlordane and ln p,p’ DDT. Also, we found an association between WC and ln oxychlordane and ln hpcdd in subjects with detectable levels of POPs, whereas an association between WC and ln p,p’ DDT was observed in all subjects. Furthermore, ln Ocdd showed an increase with higher WC and BMI, whereas, ln trans-nonachlor decreased with higher BMI. Hence, BMI and WC are associated with POPs levels, making the chemicals plausible contributors to the obesity epidemic
An Examination of the Association of Selected Toxic Metals with Total and Central Obesity Indices: NHANES 99-02
It is conceivable that toxic metals contribute to obesity by influencing various aspects of metabolism, such as by substituting for essential micronutrients and vital metals, or by inducing oxidative stress. Deficiency of the essential metal zinc decreases adiposity in humans and rodent models, whereas deficiencies of chromium, copper, iron, and magnesium increases adiposity. This study utilized the NHANES 99-02 data to explore the association between waist circumference and body mass index with the body burdens of selected toxic metals (barium, cadmium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten). Some of the associations were significant direct relationships (barium and thallium), and some of the associations were significant inverse relationships (cadmium, cobalt, cesium, and lead). Molybdenum, antimony, and tungsten had mostly insignificant associations with waist circumference and body mass index. This is novel result for most of the toxic metals studied, and a surprising result for lead because high stored lead levels have been shown to correlate with higher rates of diabetes, and obesity may be a key risk factor for developing diabetes. These associations suggest the possibility that environmental exposure to metals may contribute to variations in human weight gain/loss. Future research, such as prospective studies rather than the cross-sectional studies presented here, is warranted to confirm these findings
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