128 research outputs found
A variable streamflow velocity method for global river routing model: model description and preliminary results
International audienceThis paper presents an attempt of simulating daily fluctuations of river discharge at global scale. Total Runoff Integrating Pathways (TRIP) is a global river routing model which can help to isolate the river basins, inter-basin transport of water through river channels, as well as collect and route runoff to the river mouths for all the major rivers. In the previous version of TRIP (TRIP 1.0), a simple approach of constant river flow velocity is used. In general, that approach is sufficient to model mean long-term discharges. However, to model short-term fluctuations, more sophisticated approach is required. In this study, we implement a variable streamflow velocity method to TRIP (TRIP 2.0) and validate the new approach over the world's 20 major rivers. Two numerical experiments, one with the TRIP 1.0 and another with TRIP 2.0 are performed. Input runoff is taken from the multi-model product provided by the second Global Soil Wetness Project. For the rivers which have clear daily fluctuations of river discharge, TRIP 2.0 shows advantages over TRIP 1.0, suggesting that TRIP 2.0 can be used to model flood events
A case of hepatic cyst-induced internal jugular venous thrombosis
• Echocardiography can demonstrate hepatic cyst–induced right atrial compression. • Hepatic cyst–induced blood flow stasis can cause internal jugular venous thrombus. • Laparoscopic deroofing of hepatic cysts is a safe and effective treatment
CW Interference Effects on High Data Rate Transmission Through the ACTS Wideband Channel
Satellite communications channels are susceptible to various sources of interference. Wideband channels have a proportionally greater probability of receiving interference than narrowband channels. NASA's Advanced Communications Technology Satellite (ACTS) includes a 900 MHz bandwidth hardlimiting transponder which has provided an opportunity for the study of interference effects of wideband channels. A series of interference tests using two independent ACTS ground terminals measured the effects of continuous-wave (CW) uplink interference on the bit-error rate of a 220 Mbps digitally modulated carrier. These results indicate the susceptibility of high data rate transmissions to CW interference and are compared to results obtained with a laboratory hardware-based system simulation and a computer simulation
Impact of perception and assessment of consumers on willingness to pay for upgraded fresh pork: An experimental study in Vietnam
Traditional pork shops play an essential role in delivering pork, the most popular food in Vietnam, to consumers. Studies have shown the need for investment in training and equipment to improve the safety of pork sold at traditional shops. However, it remains unclear how consumers perceived improvement to the hygiene in pork shops and if they are ready to pay premium prices for safer products. This study used an experimental approach to determine consumers' perception and assessment of improved pork shops and their willingness to pay (WTP) for pork products. A total of 152 respondents in two provinces in Vietnam joined in a Becker–DeGroot–Marschak (BDM) mechanism experiment to collect data on WTP for pork from typical and upgraded pork shops. A questionnaire was used to record consumers' perceptions and assessments of the pork shops and products. Overall, consumers were willing to pay 20% more for upgraded fresh pork than for what is currently available on the market. Consumers trusted in the effectiveness of the upgraded intervention and the quality of pork at the pork shop, which increased their WTP for the upgraded pork. Concerns about contaminated pork had a negative impact on the WTP for typical pork, while the high frequency of pork consumption and the existence of elderly family members led to higher WTP for both products. The findings indicate the potential economic benefit of upgrading pork shops, which would be an important driver to motivate sellers to improve food safety
Social Determinants of Long Lasting Insecticidal Hammock-Use Among the Ra-Glai Ethnic Minority in Vietnam: Implications for Forest Malaria Control
BACKGROUND: Long-lasting insecticidal hammocks (LLIHs) are being evaluated as an additional malaria prevention tool in settings where standard control strategies have a limited impact. This is the case among the Ra-glai ethnic minority communities of Ninh Thuan, one of the forested and mountainous provinces of Central Vietnam where malaria morbidity persist due to the sylvatic nature of the main malaria vector An. dirus and the dependence of the population on the forest for subsistence - as is the case for many impoverished ethnic minorities in Southeast Asia. METHODS: A social science study was carried out ancillary to a community-based cluster randomized trial on the effectiveness of LLIHs to control forest malaria. The social science research strategy consisted of a mixed methods study triangulating qualitative data from focused ethnography and quantitative data collected during a malariometric cross-sectional survey on a random sample of 2,045 study participants. RESULTS: To meet work requirements during the labor intensive malaria transmission and rainy season, Ra-glai slash and burn farmers combine living in government supported villages along the road with a second home at their fields located in the forest. LLIH use was evaluated in both locations. During daytime, LLIH use at village level was reported by 69.3% of all respondents, and in forest fields this was 73.2%. In the evening, 54.1% used the LLIHs in the villages, while at the fields this was 20.7%. At night, LLIH use was minimal, regardless of the location (village 4.4%; forest 6.4%). DISCUSSION: Despite the free distribution of insecticide-treated nets (ITNs) and LLIHs, around half the local population remains largely unprotected when sleeping in their forest plot huts. In order to tackle forest malaria more effectively, control policies should explicitly target forest fields where ethnic minority farmers are more vulnerable to malaria
Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts
As the adverse impacts of hydrological extremes increase in many regions of the world, a better
understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk
management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about
the processes, interactions, and feedbacks in complex human–water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e. two floods
or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and
cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both
floods and droughts, in the number of cases assessed and in the quantity of socio-hydrological data. The benchmark dataset comprises (1) detailed review-style reports about the events and key processes between the two
events of a pair; (2) the key data table containing variables that assess the indicators which characterize management shortcomings, hazard, exposure, vulnerability, and impacts of all events; and (3) a table of the indicators
of change that indicate the differences between the first and second event of a pair. The advantages of the
dataset are that it enables comparative analyses across all the paired events based on the indicators of change
and allows for detailed context- and location-specific assessments based on the extensive data and reports of
the individual study areas. The dataset can be used by the scientific community for exploratory data analyses, e.g. focused on causal links between risk management; changes in hazard, exposure and vulnerability; and
flood or drought impacts. The data can also be used for the development, calibration, and validation of sociohydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al., 2023,
https://doi.org/10.5880/GFZ.4.4.2023.001)
Seasonal and annual fluxes of nutrients and organic matter from large rivers to the Arctic Ocean and surrounding seas
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 35 (2012): 369-382, doi:10.1007/s12237-011-9386-6.River inputs of nutrients and organic matter impact the biogeochemistry of arctic
estuaries and the Arctic Ocean as a whole, yet there is considerable uncertainty about the
magnitude of fluvial fluxes at the pan-arctic scale. Samples from the six largest arctic
rivers, with a combined watershed area of 11.3 x 106 km2, have revealed strong seasonal
variations in constituent concentrations and fluxes within rivers as well as large
differences among the rivers. Specifically, we investigate fluxes of dissolved organic
carbon, dissolved organic nitrogen, total dissolved phosphorus, dissolved inorganic
nitrogen, nitrate, and silica. This is the first time that seasonal and annual constituent
fluxes have been determined using consistent sampling and analytical methods at the pan
arctic scale, and consequently provide the best available estimates for constituent flux
from land to the Arctic Ocean and surrounding seas. Given the large inputs of river water
to the relatively small Arctic Ocean, and the dramatic impacts that climate change is
having in the Arctic, it is particularly urgent that we establish the contemporary river
fluxes so that we will be able to detect future changes and evaluate the impact of the
changes on the biogeochemistry of the receiving coastal and ocean systems.This work was supported by the National Science Foundation through grants
OPP-0229302, OPP-0519840, OPP-0732522, and OPP-0732944. Additional support was
provided by the U. S. Geological Survey (Yukon River) and the Department of Indian
and Northern Affairs (Mackenzie River)
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