Health risks of irrigation with untreated urban wastewater in the southern Punjab, Pakistan

Irrigation water / Water quality / Water reuse / Waste waters / Risks / Public health / Diseases / Farmers / Pakistan / Southern Punjab / Haroonabad

Epistemic Protocols for Distributed Gossiping

Gossip protocols aim at arriving, by means of point-to-point or group communications, at a situation in which all the agents know each other's secrets. We consider distributed gossip protocols which are expressed by means of epistemic logic. We provide an operational semantics of such protocols and set up an appropriate framework to argue about their correctness. Then we analyze specific protocols for complete graphs and for directed rings.Comment: In Proceedings TARK 2015, arXiv:1606.0729

Optimal linear estimation and data fusion

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Optimal mean square linear estimators are determined for general uncorrelated noise. We allow the noise variance matrix in the observation process to be singular. This requires properties of generalized inverses which are developed in Section II. The proofs appear to be new. When there are two observation sequences the optimal method of recursively fusing the two is determined. We derive a new formula for the covariance of the two estimates which then provides exact dynamics for a fused estimate.Elliott, R.J. ; van der Hoek, J

A deterministic discretisation-step upper bound for state estimation via Clark transformations

Copyright © 2004 Hindawi Publishing CorporationWe consider the numerical stability of discretisation schemes for continuous-time state estimation filters. The dynamical systems we consider model the indirect observation of a continuous-time Markov chain. Two candidate observation models are studied. These models are (a) the observation of the state through a Brownian motion, and (b) the observation of the state through a Poisson process. It is shown that for robust filters (via Clark's transformation), one can ensure nonnegative estimated probabilities by choosing a maximum grid step to be no greater than a given bound. The importance of this result is that one can choose an a priori grid step maximum ensuring nonnegative estimated probabilities. In contrast, no such upper bound is available for the standard approximation schemes. Further, this upper bound also applies to the corresponding robust smoothing scheme, in turn ensuring stability for smoothed state estimates.W. P. Malcolm, R. J. Elliott, and J. van der Hoe

Potential and Constraints for Animal Feed as an Objective of Poor Farmers in Participatory Research with Multipurpose Forage Crops in Central-America

Multipurpose forage crops can play an important role in improving the environmental and socio- economic sustainability of smallholder production systems in fragile environments. However, since the forage technology development framework has not been sufficiently applicable for poor farmers, adoption of especially legumes has been generally low (Peters et al., 2001). In a participatory research effort with smallholder farmers in Honduras focused at forage based technologies, food security turned out to be the main selection criterion whereas animal feed was secondary. Since animal feed related activities (farmer-led forage seed systems, production of dry season feed) have been identified as promising income generating options for poor farmers in the hillsides of Central-America, a further analysis was carried out to identify the (mainly household related) factors inducing or inhibiting farmers to opt for production of animal feed

Use of untreated wastewater in peri-urban agriculture in Pakistan: risks and opportunities

Water reuse / Waste waters / Water quality / Groundwater / Irrigation practices / Soil properties / Environmental effects / Conjunctive use / Pakistan / Haroonabad

Economic Benefits of Sustainable, Forage-Based Cattle Systems in Colombia and Nicaragua

Forage-based cattle systems play a key role in rural economies of developing countries in terms of food security and poverty alleviation, particularly in tropical Latin America. However, they are often related to being a major cause of negative environmental impacts by contributing to increased greenhouse gas emissions, land degradation, and the reduction of biodiversity. Significant resources have been allocated to research and development in forage material improvement, including selection and breeding. A broad range of improved materials were released by private and public sector actors showing superior characteristics in terms of productivity and environmental impacts compared to native or naturalized materials. Profitability is a fundamental attribute to incentivize or generate adoption of new systems by cattle producers, but this information is often not available to the livestock producer or the extension agents supporting decision-making processes. This research provides an overview on the economic viability of integrating different improved forage varieties in sustainably intensified cattle production systems in Colombia and Nicaragua. Our evaluations show that, despite higher establishment and management costs, integrating improved forage technologies (and management practices) in sustainably intensified cattle systems, either as monoculture, grass-legume associations, silvo-pastoral systems, or in combination with improved management strategies (e.g., intensive, or rotational grazing), not only make sense from the environmental and productive perspectives but also in terms of economic viability. In nearly all evaluated scenarios, the economic indicators improve by integrating improved forage technologies. Strong increases were observed for the following indicators: a) net income, b) unit profit margin, c) Net Present Value, d) Internal Rate of Return, and f) benefit-cost ratio. Strong decreases were observed for the following indicators: a) unit production cost, b) risk of obtaining economic loss, c) payback time, d) minimum area required for a profitable system, and e) sensitivity of the system to external shocks. This information will help cattle producers, extensionists and policymakers to make more holistic and informed land-use decisions that include productive, environmental, economic, and social benefits, and by this contributes to the broader adoption of more sustainable production systems

The CLEANED Approach for Flagging and Addressing Environmental Issues

While livestock presents an important livelihood strategy for many smallholders, it is also held responsible for important environmental impacts. In this paper, we used an online survey to identify the perceptions of global livestock experts on environmental impacts of livestock and how these might be tackled. We then explored how the CLEANED environmental ex-ante assessment tool (Comprehensive Livestock Environmental Assessment for improved Nutrition, a secured Environment and sustainable Development = CLEANED) responds to this and how it can be used to influence decision making towards more environmentally-friendly livestock production. According to the survey, there was general agreement between researchers, development practitioners and policy makers alike that livestock production systems are at risk of global environmental change while at the same time contributing to it. The major risks are perceived to be climate-related. The major impacts associated with livestock production, on the other hand, are considered to be land-related (degradation and competition for land), closely followed by pressure on water and GHG emissions. More sustainable livestock production practices are cited as most promising to reducing livestock’s environmental impact. The preferred technologies include managed grazing, improved pastures, silvo-pastoral systems and planted forages. A lack of rapidly available, site- and system-specific knowledge about such solutions and their potential environmental impacts are considered an important barrier to their successful implementation. The CLEANED environmental ex-ante assessment model aims to fill part of this gap. It can compare the relevant environmental impact indicators of the different solutions brought forward. The model has also been designed to be flexible when applied to a wide variety of contexts and provide systems-specific results. The expert survey further revealed that researchers, development practitioners and policy makers all based decisions on information, obtained from a variety of sources such as journal papers, internet searches and professional networks. The importance of journal papers, however, decreases as an information source from researchers over policy makers to development practitioners, while the use of professional networks and internet searches increases for these groups. This finding points to the importance of the participatory approach taken by the CLEANED team and the need to present results in appropriate multi-stakeholder forums and targeted internet posts. Further recommendations are made for increasing the use of the tool, i.e. making the outputs from the tool easier to interpret and training a variety of stakeholders in its use

Alternate wet/dry irrigation in rice cultivation: a practical way to save water and control malaria and Japanese encephalitis?

Water management / Water scarcity / Water use efficiency / Water conservation / Irrigated farming / Waterborne diseases / Rice / Malaria / Disease vectors / Productivity / Flood irrigation / Environmental control / Climate / China / East Africa / India / Indonesia / Japan / Philippines / Portugal / USA

Performance of Rotational Grazing of \u3ci\u3eUrochloa\u3c/i\u3e Hybrid cv. Cayman in the Caribbean Region of Costa Rica

In Costa Rica pasture-based grass is the basis for both dairy and beef production. The Caribbean region with a rainfall exceeding 3000 mm has four seasons: dry (Feb-May), rainy (May-Aug), less rainy (Sep-Oct) and intermediate (Oct-Feb). Many pastures are dominated by Ischaemum ciliare (“Retana”), of poor nutritional quality and permanently grazed with low stocking rates (one animal per ha). To assess the potential of combining improved grasses with rotational grazing, a trial with Urochloa hybrid cv. Cayman was implemented at the INTA research station in Guápiles, Limón province, during four years (2014 to 2018). An intensive pasture management system based on the Voisin rational grazing methodology was applied in 21 paddocks of 0.2 ha, using 10-15 Brahman or Brahman x Simbrah steers, with 2.3 days of grazing and 46 days of pasture regrowth. For each year, the effect of growing season was determined on botanical composition, biomass production, intake and live weight gain. The botanical composition remained generally unchanged, with some encroachment of I. ciliare. Dry matter production increased during the first three years from 3.8 to 6.7 Mg, stabilizing in the fourth year; biomass availability was highest during the rainy season (6.6 Mg of DM/ha) and lowest during the dry season (4.2 Mg of DM/ha). Intake was 2.4% of live weight. Dry matter digestibility and crude protein content were 61% and 7% respectively. Average stocking rate was 2.4 Livestock Units (of 450 kg LW) per ha. The climatic seasons affected significantly LWG, which varied from 0.40 (intermediate season) to 0.82 (dry season) kg day-1 animal-1. Intensive rotational grazing with improved grass cv. Cayman lead to superior forage availability, stocking rates and LWG. However, very humid conditions reduce daily live weight gain by 50% and ways must be sought to improve animal wellbeing during the rainy periods