The role of land and water for trade and food production in Latin America: Environmental trade-offs of agricultural intensification versus extensification

One of humanity’s major challenges of the 21st century will be meeting future food demands on an increasingly resource constrained-planet. Global food production will have to rise by 70 percent between 2000 and 2050 to meet effective demand which poses major challenges to food production systems. Doing so without compromising environmental integrity is an even greater challenge. This study looks at the interdependencies between land and water resources, agricultural production and environmental outcomes in Latin America and the Caribbean (LAC), an area of growing importance in international agricultural markets. Special emphasis is given to the role of LAC’s agriculture for (a) global food security and (b) environmental sustainability. We use the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT)—a global dynamic partial equilibrium model of the agricultural sector—to run different future production scenarios, and agricultural trade regimes out to 2050, and assess changes in related environmental indicators. Results indicate that further trade liberalization is crucial for improving food security globally, but that it would also lead to more environmental pressures in some regions across Latin America. Contrasting land expansion versus more intensified agriculture shows that productivity improvements are generally superior to agricultural land expansion, from an economic and environmental point of view. Finally, our analysis shows that there are trade-offs between environmental and food security goals for all agricultural development paths

Determinants of facility level environmental inspections

As environmental regulatory agencies have limited resources to enforce compliance, they tend to optimize the efficiency of resource allocation by employing targeting strategies. This thesis investigates the scheduling of Clean Water Act inspections in Illinois and the extent to which these inspections are memoryless. Using facility level and local EPA agency level data, we test inspection strategies for common decision factors, such as environmental performance, and compare them across the different jurisdictions in Illinois. Our analysis has several key results. First, at the facility level, a majority of inspections are memoryless, though they are targeted according to local jurisdiction parameters. Second, although some facilities are targeted for more frequent non-memoryless inspections, none of our environmental performance parameters seem to influence this sorting. Finally, different inspection types are implemented in different ways, suggesting that they serve distinct purposes in the regulatory process

A Dynamic Simulation/optimization Model for Scheduling Restoration of Degraded Military Training Lands

Intensive use of military vehicles on Department of Defense training installations causes deterioration in ground surface quality. Degraded lands restrict the scheduled training activities and jeopardize personnel and equipment safety. We present a simulation-optimization approach and develop a discrete dynamic optimization model to determine an optimum land restoration for a given training schedule and availability of financial resources to minimize the adverse effects of training on military lands. The model considers weather forecasts, scheduled maneuver exercises, and unique qualities and importance of the maneuver areas. An application of this approach to Fort Riley, Kansas, shows that: i) starting with natural conditions, the total amount of training damages would increase almost linearly and exceed a quarter of the training area and 228 gullies would be formed (mostly in the intensive training areas) if no restoration is carried out over 10 years; ii) assuming an initial state that resembles the present conditions, sustaining the landscape requires an annual restoration budget of $957 thousand; iii) targeting a uniform distribution of maneuver damages would increase the total damages and adversely affect the overall landscape quality, therefore a selective restoration strategy may be preferred; and iv) a proactive restoration strategy would be optimal where land degradations are repaired before they turn into more severe damages that are more expensive to repair and may pose a higher training risk. The last finding can be used as a rule-of-thumb for land restoration efforts in other installations with similar characteristics

Discriminating between the activities of human cathepsin G and chymase using fluorogenic substrates

Cathepsin G (CG) (EC 3.4.21.20) and chymase (EC 3.4.21.39) are two closely-related chymotrypsin-like proteases that are released from cytoplasmic granules of activated mast cells and/or neutrophils. We investigated the potential for their substrate-binding subsites to discriminate between their substrate specificities, aiming to better understand their respective role during the progression of inflammatory diseases. In addition to their preference for large aromatic residues at P1, both preferentially accommodate small hydrophilic residues at the S1' subsite. Despite significant structural differences in the S2' subsite, both prefer an acidic residue at that position. The Ala226/Glu substitution at the bottom of the CG S1 pocket, which allows CG but not chymase to accommodate a Lys residue at P1, is the main structural difference, allowing discrimination between the activities of these two proteases. However, a Lys at P1 is accommodated much less efficiently than a Phe, and the corresponding substrate is cleaved by ?2-tryptase (EC 3.4.21.59).?We optimized a P1 Lys-containing substrate to enhance sensitivity towards CG and prevent cleavage by chymase and ?2-tryptase. The resulting substrate (ABZ-GIEPKSDPMPEQ-EDDnp) [where ABZ is O-aminobenzoic acid and EDDnp is N-(2,4-dinitrophenyl)-ethylenediamine] was cleaved by CG but not by chymase and tryptase, with a specificity constant of 190?mm(-1) ·s(-1) . This allows the quantification of active CG in cells or tissue extracts where it may be present together with chymase and tryptase, as we have shown using a HMC-1 cell homogenate and a sputum sample from a patient with severe asthma

A substrate-based approach to convert SerpinB1 into a specific inhibitor of proteinase 3, the Wegener's granulomatosis autoantigen.

International audienceThe physiological and pathological functions of proteinase 3 (PR3) are not well understood due to its close similarity to human neutrophil elastase (HNE) and the lack of a specific inhibitor. Based on structural analysis of the active sites of PR3 and HNE, we generated mutants derived from the polyvalent inhibitor SerpinB1 (monocyte/neutrophil elastase inhibitor) that specifically inhibit PR3 and that differ from wt-SerpinB1 by only 3 or 4 residues in the reactive center loop. The rate constant of association between the best SerpinB1 mutant and PR3 is 1.4 × 10⁷ M⁻¹ * s⁻¹, which is ∼100-fold higher than that observed with wt-SerpinB1 and compares with that of α1-protease inhibitor (α1-PI) toward HNE. SerpinB1(S/DAR) is cleaved by HNE, but due to differences in rate, inhibition of PR3 by SerpinB1(S/DAR) is only minimally affected by the presence of HNE even when the latter is in excess. SerpinB1(S/DAR) inhibits soluble PR3 and also membrane-bound PR3 at the surface of activated neutrophils. Moreover, SerpinB1(S/DAR) clears induced PR3 from the surface of activated neutrophils. Overall, these specific inhibitors of PR3 will be valuable for defining biological functions of the protease and may prove useful as therapeutics for PR3-related inflammatory diseases, such as Wegener's granulomatosis

Annual species risk of extinction and endangerment due to livestock production under different scenarios in Latin America and the Caribbean (2010–2050).

<p>The risk is expressed as an index in %. BAU refers to the Business-as-Usual scenario.BAU refers to the Business-as-Usual scenario. Scenarios are described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116733#pone.0116733.t001" target="_blank">Table 1</a>. The intensification (2) and sustainable intensification (3) scenarios are presented together, because both scenarios have the same productivity assumptions and they only differ in terms of water consumption and nitrogen-emissions.</p

Annual net changes in carbon stock losses due to crop production under different scenarios in Latin America and the Caribbean (2010–2050).

<p>The values represent carbon stock losses from additional land conversion occurring in each year between 2010 and 2050. The shaded area illustrates carbon storage losses between a defined lower and upper bound due to different land expansion pathways. The lower bound reflects carbon storage losses if 100% of crop land expands over existing pasture land, while the upper bound reflects carbon storage losses if 100% of crop land expands over natural vegetation. The line illustrates the mean of the lower bound and upper bound. BAU refers to the Business-as-Usual scenario. Scenarios are described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116733#pone.0116733.t001" target="_blank">Table 1</a>. The intensification (2) and sustainable intensification (3) scenarios are presented together, because both scenarios have the same productivity assumptions and they only differ in terms of water consumption and nitrogen-emissions.</p