Payments for Watershed Services: An Application to Irrigation Pricing in the El Angel Watershed, Carchi, Ecuador

Water scarcity is increasingly viewed as the principal constraint limiting agricultural production and human livelihood improvement in the rural areas of many developing countries. Policies that encourage more efficient and equitable water use - including the introduction of incentive-based water pricing systems - are an important challenge. This paper reports the results of a mathematical programming model which was constructed for the El Angel watershed in northern Ecuador with the goal of exploring the effects of several water pricing alternatives. The model incorporates farmers' crop and pasture planting and resource allocation decisions, based on maximizing regional gross margin subject to land, water, labor, seasonal, food security and other constraints. Four water pricing scenarios are examined. The results show that adequate water resources currently exist to permit a reallocation of water within the watershed, which would generate higher regional production and incomes. Several water pricing alternatives are explored which would discipline water use in those parts of the watershed where water is currently overused and unregulated. Incomes could be significantly increased in currently waterscarce parts of the watershed while generating only small reductions in production and incomes in water-abundant zones. While tradeoffs exist among economic, environmental and employment goals, significant net gains are achievable. If a differentiated system of water prices is considered to be unrealistic, a system of single seasonal prices would likely generate reduced, though significant, benefits. Introducing a system of comprehensive water charges would likely create similar benefits in other developing country watersheds facing similar resource constraints.Resource /Energy Economics and Policy,

Selective Jamming of LoRaWAN using Commodity Hardware

Long range, low power networks are rapidly gaining acceptance in the Internet of Things (IoT) due to their ability to economically support long-range sensing and control applications while providing multi-year battery life. LoRa is a key example of this new class of network and is being deployed at large scale in several countries worldwide. As these networks move out of the lab and into the real world, they expose a large cyber-physical attack surface. Securing these networks is therefore both critical and urgent. This paper highlights security issues in LoRa and LoRaWAN that arise due to the choice of a robust but slow modulation type in the protocol. We exploit these issues to develop a suite of practical attacks based around selective jamming. These attacks are conducted and evaluated using commodity hardware. The paper concludes by suggesting a range of countermeasures that can be used to mitigate the attacks.Comment: Mobiquitous 2017, November 7-10, 2017, Melbourne, VIC, Australi

Artificial Neural Networks for Control of a Grid-Connected Rectifier/Inverter Under Disturbance, Dynamic and Power Converter Switching Conditions

Three-phase grid-connected converters are widely used in renewable and electric power system applications. Traditionally, grid-connected converters are controlled with standard decoupled d-q vector control mechanisms. However, recent studies indicate that such mechanisms show limitations in their applicability to dynamic systems. This paper investigates how to mitigate such restrictions using a neural network to control a grid-connected rectifier/inverter. The neural network implements a dynamic programming algorithm and is trained by using backpropagation through time. To enhance performance and stability under disturbance, additional strategies are adopted, including the use of integrals of error signals to the network inputs and the introduction of grid disturbance voltage to the outputs of a well-trained network. The performance of the neural-network controller is studied under typical vector control conditions and compared against conventional vector control methods, which demonstrates that the neural vector control strategy proposed in this paper is effective. Even in dynamic and power converter switching environments, the neural vector controller shows strong ability to trace rapidly changing reference commands, tolerate system disturbances, and satisfy control requirements for a faulted power system

Analysis of very-high surface area 3D-printed media in a moving bed biofilm reactor for wastewater treatment

Moving Bed Biofilm Reactors (MBBRs) can efficiently treat wastewater by incorporating suspended biocarriers that provide attachment surfaces for active microorganisms. The performance of MBBRs for wastewater treatment is, among other factors, contingent upon the characteristics of the surface area of the biocarriers. Thus, novel biocarrier topology designs can potentially increase MBBR performance in a significant manner. The goal of this work is to assess the performance of 3-D-printed biofilter media biocarriers with varying surface area designs for use in nitrifying MBBRs for wastewater treatment. Mathematical models, rendering, and 3D printing were used to design and fabricate gyroid-shaped biocarriers with a high degree of complexity at three different levels of specific surface area (SSA), generally providing greater specific surface areas than currently available commercial designs. The biocarriers were inoculated with a nitrifying bacteria community, and tested in a series of batch reactors for ammonia conversion to nitrate, in three different experimental configurations: constant fill ratio, constant total surface area, and constant biocarrier media count. Results showed that large and medium SSA gyroid biocarriers delivered the best ammonia conversion performance of all designs, and significantly better than that of a standard commercial design. The percentage of ammonia nitrogen conversion at 8 hours for the best performing biocarrier design was: 99.33% (large SSA gyroid, constant fill ratio), 94.74% (medium SSA gyroid, constant total surface area), and 92.73% (large SSA gyroid, constant biocarrier media count). Additionally, it is shown that the ammonia conversion performance was correlated to the specific surface area of the biocarrier, with the greatest rates of ammonia conversion (99.33%) and nitrate production (2.7 mg/L) for manufactured gyroid biocarriers with a specific surface area greater than 1980.5 m2/m3. The results suggest that the performance of commercial MBBRs for wastewater treatment can be greatly improved by manipulation of media design through topology optimization

Platelets Regulate Pulmonary Inflammation and Tissue Destruction in Tuberculosis.

RATIONALE: Platelets may interact with the immune system in tuberculosis (TB) to regulate human inflammatory responses that lead to morbidity and spread of infection. OBJECTIVES: To identify a functional role of platelets in the innate inflammatory and matrix-degrading response in TB. METHODS: Markers of platelet activation were examined in plasma from 50 patients with TB before treatment and 50 control subjects. Twenty-five patients were followed longitudinally. Platelet-monocyte interactions were studied in a coculture model infected with live, virulent Mycobacterium tuberculosis (M.tb) and dissected using qRT-PCR, Luminex multiplex arrays, matrix degradation assays, and colony counts. Immunohistochemistry detected CD41 (cluster of differentiation 41) expression in a pulmonary TB murine model, and secreted platelet factors were measured in BAL fluid from 15 patients with TB and matched control subjects. MEASUREMENTS AND MAIN RESULTS: Five of six platelet-associated mediators were upregulated in plasma of patients with TB compared with control subjects, with concentrations returning to baseline by Day 60 of treatment. Gene expression of the monocyte collagenase MMP-1 (matrix metalloproteinase-1) was upregulated by platelets in M.tb infection. Platelets also enhanced M.tb-induced MMP-1 and -10 secretion, which drove type I collagen degradation. Platelets increased monocyte IL-1 and IL-10 and decreased IL-12 and MDC (monocyte-derived chemokine; also known as CCL-22) secretion, as consistent with an M2 monocyte phenotype. Monocyte killing of intracellular M.tb was decreased. In the lung, platelets were detected in a TB mouse model, and secreted platelet mediators were upregulated in human BAL fluid and correlated with MMP and IL-1β concentrations. CONCLUSIONS: Platelets drive a proinflammatory, tissue-degrading phenotype in TB

Delivering 21st century Antarctic and Southern Ocean science

The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access, providing logistics and infrastructure, and capitalizing on international co-operation. Technological requirements include: i) innovative automated in situ observing systems, sensors and interoperable platforms (including power demands), ii) realistic and holistic numerical models, iii) enhanced remote sensing and sensors, iv) expanded sample collection and retrieval technologies, and v) greater cyber-infrastructure to process ‘big data’ collection, transmission and analyses while promoting data accessibility. These technologies must be widely available, performance and reliability must be improved and technologies used elsewhere must be applied to the Antarctic. Considerable Antarctic research is field-based, making access to vital geographical targets essential. Future research will require continent- and ocean-wide environmentally responsible access to coastal and interior Antarctica and the Southern Ocean. Year-round access is indispensable. The cost of future Antarctic science is great but there are opportunities for all to participate commensurate with national resources, expertise and interests. The scope of future Antarctic research will necessitate enhanced and inventive interdisciplinary and international collaborations. The full promise of Antarctic science will only be realized if nations act together

Genetic Variation in Heat Tolerance of the Coral Platygyra Daedalea Indicates Potential for Adaptation to Ocean Warming

Ocean warming represents the greatest threat to the persistence of reef ecosystems. Most coral populations are projected to experience temperatures above their current bleaching thresholds annually by 2050. Adaptation to higher temperatures is necessary if corals are to persist in a warming future. While many aspects of heat stress have been well studied, few data are available for predicting the capacity for adaptive cross-generational responses in corals. Consistent sets of heat tolerant genomic markers that reliably predict thermal tolerance have yet to be identified. To address this knowledge gap, we quantified the heritability and genetic variation associated with heat tolerance in Platygyra daedalea from the Great Barrier Reef. We tracked the survival of ten quantitative genetic crosses of larvae produced form six parental colonies in a heat tolerance selection experiment. We also identified allelic shifts in heat-selected (35°C) survivors compared with paired, non-selected controls (27°C). The narrow-sense heritability of survival under heat stress was 0.66 and a total of 1,069 single nucleotide polymorphisms (SNPs) were associated with different survival probabilities. While 148 SNPs were shared between several experimental crosses, no common SNPs were identified for all crosses, which suggests that specific combinations of many markers are responsible for heat tolerance. However, we found two regions that overlap with previously identified loci associated with heat tolerance in Persian Gulf populations of P. daedalea, which reinforces the importance of these markers for heat tolerance. These results illustrate the importance of high heritability and the complexity of the genomic architecture underpinning host heat tolerance. These findings suggest that this P. daedalea population has the genetic prerequisites for adaptation to increasing temperatures. This study also provides knowledge for the development of high throughput genomic tools which may screen for variation within and across populations to enhance adaptation through assisted gene flow and assisted migration

Extraparenchymal neurocysticercosis in the United States: a case report

<p>Abstract</p> <p>Introduction</p> <p>Neurocysticercosis is endemic in the developing world, but is becoming more common in the United States due to immigration.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man presented with headache, nausea and vomiting and was found to have hydrocephalus and meningitis. Brain imaging and immunological studies were suggestive of neurocysticercosis. Endoscopic removal of the cyst resulted in resolution of symptoms. This case represents a combination of two rare presentations of extraparenchymal neurocysticercosis; intraventricular neurocysticercosis and subarachnoid neurocysticercosis.</p> <p>Conclusion</p> <p>Although neurocysticercosis is pleomorphic in its presentation, extraparenchymal neurocysticercosis may be challenging to diagnose and treat. Clinicians should be aware of this condition given increasing incidence in the United States.</p

Eruption type probability and eruption source parameters at Cotopaxi and Guagua Pichincha volcanoes (Ecuador) with uncertainty quantification

Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100&nbsp;years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100&nbsp;years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100&nbsp;years, too. However, there is a substantial probability (possibly &gt;40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels

Stabilizing Pd-cerium oxide-aluminum oxide catalysts for methane oxidation by reduction pretreatments

Pd-CeO2 based catalysts are state-of-the-art for methane oxidation, but deactivate due to Pd nanoparticle growth at high temperature. While encapsulation by CeO2 shells was reported to increase the stability of Pd nanoparticles (NPs), the established synthesis methods are not easily scalable. Here, we report the synthesis of PdO/CeOx/Al2O3 and CeOx/PdO/Al2O3 catalysts with improved stability for methane oxidation by sequential impregnation of Pd and Ce precursors on an Al2O3 support followed by reduction. The reduced catalysts displayed higher methane oxidation activity, and a lowering of the light-off temperature compared to the fresh calcined catalysts. High resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS) chemical imaging of the reduced catalysts indicated a redispersion of cerium oxide on the support surface and anchoring of Pd nanoparticles by cerium oxide. After aging at high temperature (850 °C), the activity of the reduced CeOx/PdO/Al2O3 catalysts remained high, while the activity of the calcined catalysts dropped significantly. The results showed that simple reduction pretreatments could improve the catalytic activity and stability of the catalysts at both low and high reaction temperatures through changing Pd-Ce interactions, restructuring of the surface and changes in the nature and types of adsorbed species, as shown by HRTEM, EDS and operando diffuse reflectance infrared Fourier transform spectroscopy. We believe that the proposed strategy can be used as a scalable alternative to embedding of Pd NPs by CeO2 in core-shell systems for enhanced thermal stability in exhaust after treatment applications