Integrating fish resources to agro-ecosystem analyses

In October 2005, a consortium of partners led by the International Water Management Institute (IWMI) proposed a project aimed at integrating fish resources management in agricultural management in the Tonle Sap area. This 2-years project assistance was accepted for funding by the Challenge Program on Water and Food and started in January 2008. The overall goal of this project is to improve allocation and use of water in combined farming and fishing systems in order to enhance food security of rural communities and water productivity. The general objectives of the Fisheries component are: 1) to contribute to the review of existing fisheries and aquaculture information, assessment and data collection systems and existing databases from a fisheries perspective 2) to determine key questions that could be asked at the commune level that would enable the identification of fisheries issues for different agroecosystem zones. These would include both threats and potential threats to fisheries based on key ecological variables and opportunities that fisheries and aquaculture could represent in local livelihoods.Research, Lake fisheries, Agropisciculture, Ecosystems, Analysis, Cambodia, Tonle Sap L.,

Cooperative and Distributed Localization for Wireless Sensor Networks in Multipath Environments

We consider the problem of sensor localization in a wireless network in a multipath environment, where time and angle of arrival information are available at each sensor. We propose a distributed algorithm based on belief propagation, which allows sensors to cooperatively self-localize with respect to one single anchor in a multihop network. The algorithm has low overhead and is scalable. Simulations show that although the network is loopy, the proposed algorithm converges, and achieves good localization accuracy

Distributed Local Linear Parameter Estimation using Gaussian SPAWN

We consider the problem of estimating local sensor parameters, where the local parameters and sensor observations are related through linear stochastic models. Sensors exchange messages and cooperate with each other to estimate their own local parameters iteratively. We study the Gaussian Sum-Product Algorithm over a Wireless Network (gSPAWN) procedure, which is based on belief propagation, but uses fixed size broadcast messages at each sensor instead. Compared with the popular diffusion strategies for performing network parameter estimation, whose communication cost at each sensor increases with increasing network density, the gSPAWN algorithm allows sensors to broadcast a message whose size does not depend on the network size or density, making it more suitable for applications in wireless sensor networks. We show that the gSPAWN algorithm converges in mean and has mean-square stability under some technical sufficient conditions, and we describe an application of the gSPAWN algorithm to a network localization problem in non-line-of-sight environments. Numerical results suggest that gSPAWN converges much faster in general than the diffusion method, and has lower communication costs, with comparable root mean square errors

Reconstructing past atmospheric circulation changes using oxygen isotopes in lake sediments from Sweden

Here we use lake sediment studies from Sweden to illustrate how Holocene-aged oxygen isotope records from lakes located in different hydrological settings, can provide information about climate change. In particular changes in precipitation, atmospheric circulation and water balance. We highlight the importance of understanding the present lake hydrology, and the relationship between climate variables and the oxygen isotopic composition of precipitation (18Op) and lake waters (18Olakewater) for interpretation of the oxygen isotopic record from the sediments (18O). Both precipitation reconstructions from northern Sweden and water balance reconstructions from south and central Sweden show that the atmospheric circulation changed from zonal to a more meridional airflow over the Holocene. Superimposed on this Holocene trend are δ18Op minima resembling intervals of the negative phase of the North Atlantic Oscillation (NAO), thus suggesting that the climate of Northern Europe is strongly influenced by atmospheric and oceanic circulation changes over the North Atlantic

Social-Aware Edge Caching in Fog Radio Access Networks

Fog radio access networks (F-RANs) are becoming an emerging and promising paradigm for fifth generation cellular communication systems. In F-RANs, distributed edge caching techniques among remote radio heads (RRHs) and user equipment (UE) can effectively alleviate the burdens on the fronthaul toward the base band unit pool and the bandwidth of the RANs. However, it is still not clear as to how social relationships affect the performance of edge caching schemes. This paper attempts to analyze the impact of mobile social networks (MSNs) on the performance of edge caching in F-RANs. We propose a Markov-chain-based model to analyze edge caching among edge nodes (i.e., RRHs and MSNs), as well as data sharing among the potential MSNs from the viewpoint of content diffusion in the F-RANs. Moreover, we analyze the edge caching schemes among UE to minimize the bandwidth consumption in the RANs. Finally, the optimal edge caching strategies among RRHs in terms of caching locations and time are introduced to minimize the bandwidth consumption of fronthaul and storage costs in the F-RANs. Simulation results show that the proposed edge caching schemes among UE and RRHs are able to reduce the bandwidth consumption of RANs and fronthaul effectively

Understanding the hydrogeology and surface flow in the Cuatrocienegas Basin (NE Mexico) using stable isotopes

In this paper we present surface water oxygen (δ18O), hydrogen (δD) and inorganic carbon (δ13CDIC) isotope data to gain a better understanding of the modern day hydrogeology of Cuatrociénegas Basin, a semi-arid region in northeastern Mexico. Our study focuses on 26 water samples collected in March 2008 to investigate: 1) current provenance and flow pathways of surface waters, 2) the use of stable isotopes in identifying water loss and environmental degradation, and 3) human influence on hydrogeology. δ18O for Cuatrociénegas water samples ranged from −7.99 to +4.97‰ (mean −5.23 ± 3.13‰), δD from −54.8 to +0.3‰ (mean −42.4 ± 14.4‰), and δ13CTDICfrom −21.6 to −9.2‰ (mean −14.3 ± 3.4‰). Samples collected progressively away from their respective spring lines display increasing δ18O and δD values. Isotope data suggest that where the residence time of the groundwater is long and/or the system is hydrologically open, δ18O may not be a reliable indicator of water loss and environmental degradation. Our data suggest the central ciénega (area W(b)) is the most viable area for palaeoenvironmental study and long term monitoring is an essential tool in the identification of ecosystem damage and response, allowing for better future management of the complex and fragile CCB ecosystem

Financial Technologies: a Note on Mobile Payment

The financial market is currently disrupted by the rise of new technologies "FinTech” a short form for financial technology, which profoundly reshapes the financial intermediary structure and makes financial services more efficient. Mobile technology with Internet-enabled devices are the next logical phase of the World Wide Web campaign such as mobile phone taking over the mass market and will fundamentally change the way products are buy and sell as well as financial services especially the mobile payment system. This research examines changes payment method in financial services, particularly those involving mobile payments that can create new channels for consumers to purchase goods and services using mobile phone. Mobile payment application is ready to replace traditional cash, checks, credit and debit card throughout the country. In this stage of development, the current situation of mobile payment market, review the previous literature on mobile payment services, analysis use of mobile payment worldwide and various initiatives use mobile phones to offer financial services for those ‘unbanked\u27