67 research outputs found

    Reproductive ecology of wrinkle-lipped free-tailed bats Chaerephon plicatus (Buchannan, 1800) in Rrelation to Guano Production in Cambodia

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    Wildlife populations in Southeast Asia are subject to increasing pressure from climate change, habitat loss and human disturbance. Cave-roosting bats are particularly vulnerable to all three factors. Because of the ecological services they provide, it is important to assess specific vulnerabilities to inform their conservation management. We evaluated the reproductive phenology and body condition of Chaerephon plicatus for 14 months in 2015–2016 and quantified guano harvesting at the largest colony in Cambodia in 2011–2016. As in Thailand and Myanmar, two annual breeding cycles were recorded, characterized as continuous bimodal polyoestry, with parturition primarily occurring in April and October. Significant declines occurred in body condition between the late wet season and the late dry season, suggesting that bats experience increasing energetic stress as the dry season progresses. Annual guano harvests increased over the study period but could not be used as a proxy for monitoring population size due to the loss of unknown amounts during the wet season and unquantified movements of bats between C. plicatus colonies in the region. We recommend studies to determine the scale and drivers of such movements and creation of sustainable guano harvesting and population monitoring initiatives to ensure the conservation of C. plicatus colonies in Cambodia

    Recursive quantum repeater networks

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    Internet-scale quantum repeater networks will be heterogeneous in physical technology, repeater functionality, and management. The classical control necessary to use the network will therefore face similar issues as Internet data transmission. Many scalability and management problems that arose during the development of the Internet might have been solved in a more uniform fashion, improving flexibility and reducing redundant engineering effort. Quantum repeater network development is currently at the stage where we risk similar duplication when separate systems are combined. We propose a unifying framework that can be used with all existing repeater designs. We introduce the notion of a Quantum Recursive Network Architecture, developed from the emerging classical concept of 'recursive networks', extending recursive mechanisms from a focus on data forwarding to a more general distributed computing request framework. Recursion abstracts independent transit networks as single relay nodes, unifies software layering, and virtualizes the addresses of resources to improve information hiding and resource management. Our architecture is useful for building arbitrary distributed states, including fundamental distributed states such as Bell pairs and GHZ, W, and cluster states.Comment: 14 page

    Climate Change Adaptation in Post-Disaster Recovery Processes: Flood-Affected Communities in Cambodia and Fiji

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    By adopting an integrated and participatory action-research approach, this project explores how rural communities living in flood-prone river basins of Cambodia and Fiji respond to increasing variability of flood incidences and other natural hazards under the influence of climate change and other risk factors, such as hydro-electric power development, forest conversion and environmental degradation. Particular emphasis is placed on risk perceptions and adaptive strategies of individuals, families and social groups with regard to regular and catastrophic floods and how the livelihoods of vulnerable groups are affected by floods and other disasters. Our research approach integrates the food, water and energy security nexus with the rural livelihood framework. The objectives of the project are to (1) identify the spatial extent and dynamics of flood hazards as a result of multiple risk factors; (2) determine the various factors that can enhance resilience and adaptive capacities of flood-affected communities in a changing environment, and (3) provide examples of successful community-based flood management and climate change adaptation that can serve as best-practice models for other flood affected communities in the Asia-Pacific region

    Path Selection for Quantum Repeater Networks

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    Quantum networks will support long-distance quantum key distribution (QKD) and distributed quantum computation, and are an active area of both experimental and theoretical research. Here, we present an analysis of topologically complex networks of quantum repeaters composed of heterogeneous links. Quantum networks have fundamental behavioral differences from classical networks; the delicacy of quantum states makes a practical path selection algorithm imperative, but classical notions of resource utilization are not directly applicable, rendering known path selection mechanisms inadequate. To adapt Dijkstra's algorithm for quantum repeater networks that generate entangled Bell pairs, we quantify the key differences and define a link cost metric, seconds per Bell pair of a particular fidelity, where a single Bell pair is the resource consumed to perform one quantum teleportation. Simulations that include both the physical interactions and the extensive classical messaging confirm that Dijkstra's algorithm works well in a quantum context. Simulating about three hundred heterogeneous paths, comparing our path cost and the total work along the path gives a coefficient of determination of 0.88 or better.Comment: 12 pages, 8 figure

    evaluation of advanced routing strategies with information theoretic complexity measures

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    Based on hierarchy and recursion (shortly, HR), recursive networking has evolved to become a possible architecture for the future Internet. In this paper, we advance the study of HR-based routing by means of the Gershenson-Fernandez information-theoretic framework, which provides four different complexity measures. Then, we introduce a novel and general approach for computing the information associated to a known or estimated routing table. Finally, we present simulation results regarding networks that are characterized by different topologies and routing strategies. In particular, we discuss some interesting facts we observed while comparing HR-based to traditional routing in terms of complexity measures

    Application of handheld devices to field research among underserved construction worker populations: a workplace health assessment pilot study

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    This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Novel low-cost approaches for conducting rapid health assessments and health promotion interventions among underserved worker groups are needed. Recruitment and participation of construction workers is particularly challenging due to their often transient periods of work at any one construction site, and their limited time during work to participate in such studies. In the present methodology report, we discuss the experience, advantages and disadvantages of using touch screen handheld devices for the collection of field data from a largely underserved worker population. METHODS: In March 2010, a workplace-centered pilot study to examine the feasibility of using a handheld personal device for the rapid health assessment of construction workers in two South Florida Construction sites was undertaken. A 45-item survey instrument, including health-related questions on tobacco exposure, workplace safety practices, musculoskeletal disorders and health symptoms, was programmed onto Apple iPod Touch® devices. Language sensitive (English and Spanish) recruitment scripts, verbal consent forms, and survey questions were all preloaded onto the handheld devices. The experience (time to survey administration and capital cost) of the handheld administration method was recorded and compared to approaches available in the extant literature. RESULTS: Construction workers were very receptive to the recruitment, interview and assessment processes conducted through the handheld devices. Some workers even welcomed the opportunity to complete the questionnaire themselves using the touch screen handheld device. A list of advantages and disadvantages emerged from this experience that may be useful in the rapid health assessment of underserved populations working in a variety of environmental and occupational health settings. CONCLUSIONS: Handheld devices, which are relatively inexpensive, minimize survey response error, and allow for easy storage of data. These technological research modalities are useful in the collection and assessment of environmental and occupational research data.This study was supported in part by the National Institute for Occupational Safety and Health (NIOSH)'s Deep South Educational Research Center at the University of Alabama (sub-contract: 288477-10) as a Graduate Student Pilot Grant Award; the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) grant F31AR057687 and the National Institute for Occupational Safety and Health (NIOSH) grant R01 OH003915

    Development of a resource modelling tool to support decision makers in pandemic influenza preparedness: The AsiaFluCap Simulator.

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    BACKGROUND: Health care planning for pandemic influenza is a challenging task which requires predictive models by which the impact of different response strategies can be evaluated. However, current preparedness plans and simulations exercises, as well as freely available simulation models previously made for policy makers, do not explicitly address the availability of health care resources or determine the impact of shortages on public health. Nevertheless, the feasibility of health systems to implement response measures or interventions described in plans and trained in exercises depends on the available resource capacity. As part of the AsiaFluCap project, we developed a comprehensive and flexible resource modelling tool to support public health officials in understanding and preparing for surges in resource demand during future pandemics. RESULTS: The AsiaFluCap Simulator is a combination of a resource model containing 28 health care resources and an epidemiological model. The tool was built in MS Excel© and contains a user-friendly interface which allows users to select mild or severe pandemic scenarios, change resource parameters and run simulations for one or multiple regions. Besides epidemiological estimations, the simulator provides indications on resource gaps or surpluses, and the impact of shortages on public health for each selected region. It allows for a comparative analysis of the effects of resource availability and consequences of different strategies of resource use, which can provide guidance on resource prioritising and/or mobilisation. Simulation results are displayed in various tables and graphs, and can also be easily exported to GIS software to create maps for geographical analysis of the distribution of resources. CONCLUSIONS: The AsiaFluCap Simulator is freely available software (http://www.cdprg.org) which can be used by policy makers, policy advisors, donors and other stakeholders involved in preparedness for providing evidence based and illustrative information on health care resource capacities during future pandemics. The tool can inform both preparedness plans and simulation exercises and can help increase the general understanding of dynamics in resource capacities during a pandemic. The combination of a mathematical model with multiple resources and the linkage to GIS for creating maps makes the tool unique compared to other available software

    Climate change in North-Western Cambodia: impact assessment, vulnerability and scope for adaptation in upland agricultural systems

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    Increases in mean temperature, changes in rainfall patterns and increases in frequencies of extreme climate events have put more pressure on agriculture to meet the world’s food and fibre demand. Agricultural food produce amongst smallholder farms has a vital role in feeding the world population, particularly in developing countries. Over 80% of the food that is consumed in the developing world is produced by small-scale farmers. In general, small-scale farmers are unable to achieve potential yields due to inability to manage various yield-limiting factors. Predicted impact of climate change is one of the major threats to sustained agricultural productivity, especially for rainfed production systems. It is, therefore, critical to reduce constraints to achieving crop yield potential in order to minimise the adverse impacts of climate change. This study was conducted in North-West Cambodia where Pailin Province (12°52' N, 102°36' E) and Samlout District in Battambang Province (12°40' N, 102°45' E) were selected to examine climate change impacts and adaptation options for smallholder farms in the region. Locally relevant climate change projections for Battambang city (13°05' N, 103°13' E), 80 km from the study areas, were downscaled from Global Circulation Models (GCMs). The objectives of this study were to (1) better understand upland rainfed cropping systems and socio-economics of smallholder farms, (2) assess farmers' perceptions of climate variability and change against regional climate records and projections, (3) evaluate farmers’ autonomous adaptation options to short‐term climate change, and (4) investigate options for longer‐term planned adaptation measures. The thesis progresses through the following sequence. The initial stage of this study involved collection of baseline data from smallholder households on cropping systems, socio-economic context, production constraints, climate change perceptions, and perceived impacts and employed adaption options to climate change. The data were gathered from 390 representatives of households of the selected study areas in North-West (NW) Cambodia. The results showed upland crop production has a critical role in supporting the livelihoods and food security of the local people where about 70% of family income is obtained from crop production. These farmers have implemented crop intensification practices on small pieces of land to maximise their incomes. The farmers often face various significant challenges to their productivity and income such as: adverse climate impacts; soil fertility depletion; biotic constraints; high input costs; and unpredictable fluctuations in crop prices. For a five-year period between 2008 and 2012, farmers had experienced crop yield losses as perceived reductions of 16-27%. These yield reductions had posed a significant threat to the livelihoods, food security and welfare of the people. This has been in line with the rising number of young people leaving their home villages for casual employment in cities and outside the country. The baseline study also revealed that the local people perceived warming temperature, rising frequency and severity of drought and dry spells, declining annual rainfall, and a later start and later finish to the wet season. The variations and changes in climate parameters were perceived to have significant effects on the farmers’ crop productivity. The baseline study led to further research on climate change assessment and crop simulation modelling for the selected study areas. The climate assessment study involved gathering available climate records and downscaling climate change projections from 23 GCMs for the study locations. The records reveal that temperature has already become warmer, and is projected to continue warming over the remainder of the 21st century with average warming rates per decade of about 0.13oC and 0.24oC under intermediate emission (RCP4.5) and high emission scenarios (RCP8.5), respectively. The records for the current annual rainfall also showed no clear trend, but more fluctuations between years. Similarly, projections for past rainfall indicated neither downward nor upward trends, but exhibited a slight upward trend after the 2010s onwards. Furthermore, projections showed more rain would fall in the main wet season (May-October) and some would be in the very early dry season (November), while the rainfall was projected to remain low in the dry season (December-May). These findings should be taken into account in planning adaptation measures because farmers firstly need to perceive climate change correctly before they can employ effective actions to mitigate and adapt to climate change. Crop simulation modelling based on the downscaled climate change projections was used to examine climate change impacts on the current crop production strategies and explored various feasible adaptation measures for the study areas. Simulation modelling showed the current practice of planting the first crop in the late dry season (February/March) had failure rates of around 59% at Pailin and 32% at Samlout. In addition, the expected failure rates would be higher if soil fertility depletion was included in the simulation. The study suggested that farmers could grow two good crops of maize per year

    Climate change adaptation options in rainfed upland cropping systems in the wet tropics: A case study of smallholder farms in North-West Cambodia

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    While climate change is confirmed to have serious impacts on agricultural production in many regions worldwide, researchers have proposed various measures that farmers can apply to cope with and adapt to those changes. However, it is often the case that not every adaptation measure would be practical and adoptable in a specific region. Farmers may have their own ways of managing and adapting to climate change that need to be taken into account when considering interventions. This study aimed to engage with farmers to: (1) better understand small-holder knowledge, attitudes and practices in relation to perceived or expected climate change; and (2) document cropping practices, climate change perceptions, constraints to crop production, and coping and adaptation options with existing climate variability and expected climate change. This study was conducted in 2015 in Sala Krau village near Pailin (12°52′N, 102°45′E) and Samlout (12°39′N, 102°36′E) of North-West Cambodia. The methods used were a combination of focus group discussions and one-on-one interviews where 132 farming households were randomly selected. We found that farmers were conscious of changes in climate over recent years, and had a good understanding of likely future changes. While farmers are aware of some practices that can be modified to minimize risk and cope with anticipated changes, they are reluctant to apply them. Furthermore; there are no government agricultural extension services provided at the village level and farmers have relied on each other and other actors in the value chain network for information to support their decision-making. There is a lack of knowledge of the principles of conservation agriculture that urgently require agricultural extension services in the region to build farmer ability to better cope and adapt to climate change
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