106,836 research outputs found
Discussion - An empirical model of fatalities and injuries due to floods in Japan by Guofang Zhai, Teruki Fukuzono, and Saburo Ikeda
No full text[No abstract available]ASAAF H, 2002, P CAN DAM ASS CDA 20; ASSAF H, 2001, WORLD WAT ENV RES C; BROWN CA, 1988, WATER RESOUR BULL, V24, P1303; DEKAY ML, 1993, RISK ANAL, V13, P193, DOI 10.1111-j.1539-6924.1993.tb01069.x; JONKMAN SN, 2002, FLOOD DEFENCE 2002, P196; MILLER DM, 1984, AM STAT, V38, P124, DOI 10.2307-268324712
A hydro-economic model for managing groundwater resources in semi-arid regions
No full textAccess to fresh water resources is a limiting factor in the socio-economical development of countries located in semi-arid regions. Water scarcity in these regions, particularly the North Africa and Middle East (MENA) region, is expected to intensify not only due to projected decline in effective precipitation due to climate change and variability, but also due to excessive growth in demand driven by explosive growth in population and improvement in living standards. The meager surface water resources in these regions have already been exploited and significantly polluted leading many governments to deplete their fossil and poorly recharged aquifers mostly to support inefficient and unsustainable agricultural policies and heavy subsidy of municipal water demand. The paper presents an interactive decision support model developed based on economic principles and simple aquifer representation using the STELLA system dynamics development environment. The model is designed to help water policy makers and managers and other stakeholders formulate and assess alternative water allocation policies among the municipal, industrial and agriculture sectors. Model users will be able to set and interactively manipulate key parameters that influence economic values and sustainability of alternative water policies. These parameters are associated with energy prices, discount rates, planning horizon, demographic factors, willingness-to-pay, hydro-meteorological conditions, aquifer characteristics, and industrial water productivities cropping patterns and agricultural water productivities. Long-term projections of economic value, withdrawals, and remaining water stocks in addition to water demand are presented in tabular and graphical forms. The paper presents a case application of the model for managing the Amman-Zarqa aquifer in Jordan. The aquifer is considered a crucial water resource in water poor Jordan. © 2009 WIT Press.ABDULLA F, 2008, WATER RESOURCES MANA; Assaf H, 2008, ENVIRON MODELL SOFTW, V23, P1327, DOI 10.1016-j.envsoft.2008.03.006; Chebaane M, 2004, HYDROGEOL J, V12, P14, DOI 10.1007-s10040-003-0313-1; GISSER M, 1983, J POLIT ECON, V91, P1001, DOI 10.1086-261197; Griffin R.C., 2006, WATER RESOURCE EC; *ISEE SYST, STELLA SYST THINK ED; Schiffler M., 1998, EC GROUNDWATER MANAG; Winz I, 2007, P 25 INT C SYST DYN1
Geostatistical assessment of groundwater nitrate contamination with reflection on DRASTIC vulnerability assessment: The case of the upper litani basin, Lebanon
No full textGroundwater constitutes the largest single source of fresh water in many parts of the world and provides a risk buffer to sustain critical water demands during cyclic and prolonged dry periods, especially in semi-arid and arid regions. However, unprecedented socio-economical growths are threatening the viability of these precious resources through fast depletion of already critically low stocks accompanied by persistent degradation of water quality due to salinization, and contamination by pesticides and fertilizers, urban sewage and industrial waste. These circumstances are particularly true of the Upper Litani Basin (ULB), which houses over 500,000 of Lebanon's 4 million population and provides the bulk of the country's agricultural output. Uncontrolled urban, agricultural and industrial growths following a prolonged civil strife and foreign occupation have resulted in the deterioration of the quality of the basin's surface water and potentially its groundwater resources. An assessment study of groundwater quality conditions in the ULB was conducted in support of efforts to manage water quality in the basin. Geostatistical analysis of groundwater nitrate levels was conducted using data collected through an extensive basin-wide water quality survey sponsored by the USAID and covered two periods representing the summer and winter periods. The results of analysis include maps of nitrate contamination and probability of exceedance of drinking-water nitrate regulatory limit. The results indicate a significant, widespread and persistent nitrates contamination of groundwater in the ULB. Nitrate levels in groundwater exceed standard limits for drinking water in many parts of the basin. These findings were examined with respect to those of a DRASTIC groundwater vulnerability assessment conducted by the USAID BAMAS project. Comparative analysis of the two assessments shed the light on several issues related to the application and interpretation of DRASTIC scores and the groundwater nitrate contamination process. © Springer Science+Business Media B.V. 2008.ASSAF H, 2006, P IEMSS 3 BIENN M SU; *BAMAS, 2005, FIN REP; *BAMAS, 2005, TECHN SURV REP SUMM; *BAMAS, 2005, RAP REV REP; *BAMAS, 2005, GROUNDW FLOW MOD VUL; Basistha A, 2008, WATER RESOUR MANAG, V22, P1325, DOI 10.1007-s11269-007-9228-2; BELLER H, 2005, CALIFORNIA GAMA PROG; Canter LW, 1997, NITRATES GROUNDWATER; COOPER RM, 1988, J ENVIRON ENG-ASCE, V114, P270; Edmunds WM, 1997, J ENVIRON QUAL, V26, P1231; *FAO, 1997, REP DER LAND US MAP; Fritch TG, 2000, ENVIRON MANAGE, V25, P337, DOI 10.1007-s002679910026; Hamza MH, 2006, J ENVIRON MANAGE, V84, P12; Hossain F, 2007, WATER RESOUR MANAG, V21, P1245, DOI 10.1007-s11269-006-9079-2; Hussain I, 2001, 26 IWMI; Journel A. G., 1978, MINING GEOSTATISTICS; Kass A, 2005, J HYDROL, V300, P314, DOI 10.1016-j.jhydrol.2004.06.013; Li FM, 2001, AGR WATER MANAGE, V49, P173, DOI 10.1016-S0378-3774(01)00087-7; Mardikis MG, 2005, WATER RESOUR MANAG, V19, P251, DOI 10.1007-s11269-005-3179-2; ROSSI RE, 1992, ECOL MONOGR, V62, P277, DOI 10.2307-2937096; Tang C, 2004, HYDROL PROCESS, V18, P2303, DOI 10.1002-hyp.5531; VANGRINSVEN HJM, 2006, ENV HLTH, V5, P1; Vazquez JCG, 2005, WATER RESOUR MANAG, V19, P1, DOI 10.1007-s11269-005-0129-y; Ward MH, 2005, ENVIRON HEALTH PERSP, V113, P1607, DOI 10.1289-ehp.8043; Zizhen L., 1998, ECOL MODEL, V107, P279, DOI 10.1016-S0304-3800(98)00004-021191
Animal performance, carcass traits and meat characteristics of Assaf and Merino x Assaf growing lambs
No full text7 páginas, 5 tablas.This study was conducted to compare the growth, carcass and meat quality of light, intensively reared Assaf and crossbred Merino x Assaf lambs. Twelve Assaf and 12 Merino x Assaf lambs of both sexes were intensively reared from weaning until they reached 20 kg live body weight (LBW). Crossbreeding improved both daily weight gain (P<0.01) and feed conversion P<0.001), resulting in a reduction in accumulative dry matter consumption (P<0.05).
Carcass conformation was also improved by crossbreeding, although commercial cut category differences (P>0.05) were not observed. Carcass (P<0.10) and shoulder fat content (P<0.01) were breed dependent, with Assaf lambs yielding the highest values. Assaf lambs also displayed lower 24 h pH (P<0.01) and greater L* values (P<0.05) than the Merino x Assaf crossbreeds, but other, equally important parameters, such as cooking losses or shear force, were not breed dependent.
Females showed smaller weight gains (P<0.05) and higher feed conversion (P<0.01), due to differences in gain composition. Furthermore, internal (P<0.01) and shoulder fat (P<0.01) weights were higher in females. Sex dependent differences in meat quality were also related to meat fat content, with females yielding the highest values (P<0.01).
Raising Merino x Assaf lambs to a weight between suckling and fattening categories could avoid the seasonality problem in current suckling lamb production, by improving productive parameters such as growth or conformation.This work was supported by funds from FEDER (Project 1FD1997-1898) and Junta de Castilla y
León (Project GR158). Raúl Bodas has a JAE-Doc contract from the CSIC under the programme
“Junta para la Ampliación de Estudios”.Peer reviewe
Cyclic Derangements
No full textA classic problem in enumerative combinatorics is to count the number of derangements, that is, permutations with no fixed point. Inspired by a recent generalization to facet derangements of the hypercube by Gordon and McMahon, we generalize this problem to enumerating derangements in the wreath product of any finite cyclic group with the symmetric group. We also give q- and (q,t)-analogs for cyclic derangements, generalizing results of Gessel, Brenti and Chow.National Science Foundation (U.S.) (Mathematical Sciences Postdoctoral Research Fellowship DMS-0703567
Framework for Modeling Mass Disasters
No full textThis paper introduces a generic mass Disaster Modeling Framework (DMF) to support integrated sociophysical risk assessment and management of disasters. The DMF draws on the principles that disasters have many common features regardless of their instigating hazards and are the outcome of interaction between a hazard and society. The modular architecture of the DMF weakly couples three key applications: the Community Simulation Model (CSM), the Hazard Simulation Model (HSM), and the Evacuation Simulation Model (ESM). The CSM utilizes census, cadastral, and other data to construct an individual-based representation of the potentially impacted community. The CSM estimates people and built environment at risk at any given time of the day, week, and year. The CSM assessment along with the hazard simulation of the HSM feed into the ESM to simulate the progression of fatalities throughout the event. Dam failures, for which vivid and detailed accounts of human interaction with the incoming flood exist, served as case studies
Genetic dissection of "Caulobacter crescentus" surface colonization
No full textDuring its biphasic life cycle Caulobacter crescentus switches from a planktonic to surface attached life style. This transition requires the continuous remodeling of the cell poles through the temporally and spatially coordinated assembly and disassembly of polar organelles like the flagellum, pili, and an adhesive holdfast. A genetic screen for mutants affected in surface binding and colonization led to the identification of various genes required for motility, pili, and holdfast biogenesis, suggesting a specific role for all three organelles in C. crescentus surface colonization. Several novel holdfast genes were identified, which are potentially involved in the synthesis and regulation of the polysaccharidic component of the holdfast. Quantitative surface binding studies during the C. crescentus cell cycle revealed that optimal attachment coincides with the presence of flagellum, pili, and holdfast at the same pole. This indicated that accurate temporal control of polar appendices is critical for surface colonization of C. crescentus and represents the first example for developmentally controlled bacterial surface adhesion. We have used genetic and biochemical analyzes to demonstrate that di-cyclic guanosine monophosphate (c-di-GMP) is a central regulatory compound involved in the timing of C. crescentus pole development. Mutants lacking the diguanylatecyclase PleD show a dramatic delay of holdfast formation during swarmer cell differentiation. In contrast, cells lacking the GGDEF-EAL composite protein CC0091 show premature holdfast formation, while overexpression of CC0091 also leads to a delayed appearance of holdfast. The observation that CC0091 is a c-di-GMP specific phosphodiesterase indicated that the antagonistic activities of PleD and CC0091 could be responsible for the correct timing of holdfast formation and flagellum ejection. Finally, our genetic screen identified a candidate for the c-di-GMP effector protein, which mediates holdfast synthesis in response to fluctuating levels of c-di-GMP. The glycosyltransferase CC0095 is strictly required for holdfast formation and its overexpression leads to premature holdfast synthesis. This and the observation that CC0095 is able to bind c-di-GMP lead to the hypothesis that holdfast synthesis is
regulated via allosteric control of the CC0095 glycosyltransferase. These data provide the first
example of a developmental process being regulated by the bacterial second messenger, c-di-GMP
Assessing water quality management options in the Upper Litani Basin, Lebanon, using an integrated GIS-based decision support system
No full textThe widespread and relentless discharge of untreated wastewater into the Upper Litani Basin (ULB) river system in Lebanon has reached staggering levels rendering its water unfit for most uses especially during the drier times of the year. Despite the call by governmental and non-governmental agencies to develop several wastewater treatment plants and sewage networks in an effort to control this problem, these efforts do not seem to be coordinated or based on comprehensive and integrated assessments of current and projected conditions in the basin. This paper provides an overview of the development and implementation of an integrated decision support system (DSS) designed to help policy makers and other stakeholders have a clearer understanding of the key factors and processes involved in the sewage induced degradation of surface water quality in the ULB, and formulate, assess and evaluate alternative management plans. The DSS is developed based on the WEAP model, which provides a GIS based and visual simulation environment and scenario management and analysis capabilities. The DSS was used to assess two main water quality management plans taking into consideration hydrological, spatial and seasonal variabilities. An incremental cost-effectiveness analysis was conducted to identify best buy plans. The results have confirmed the gravity of this problem and demonstrated the importance of taking immediate action on curbing this onslaught on this valuable and scarce fresh water resource. © 2008 Elsevier Ltd. All rights reserved.*BAMAS, 2005, TECHN SURV REP; *BAMAS, 2005, TECHN SURV REP SUMM; Bowie G. L., 1985, RATES CONSTANTS KINE; Cadham John C., 2005, Lakes and Reservoirs Research and Management, V10, P141, DOI 10.1111-j.1440-1770.2005.00268.x; *CDR, 2005, PROGR REP 2005 MAIN; Chapman D., 1996, WATER QUALITY ASSESS; Chapra S, 1997, SURFACE WATER QUALIT; Cox BA, 2003, SCI TOTAL ENVIRON, V314, P335, DOI 10.1016-S0048-9697(03)00063-9; Eckenfelder Jr WW, 1961, BIOL WASTE TREATMENT; KASKAS A, 2000, LITANI RIVER LAKE QA; *LRA, 2004, 50 JUB BOOK LIT RIV; Pinkham R. D., 2004, CASE STUDIES EC ANAL; SIEBER J, 2005, WATER EVALUATION PLA; *US AG INT DEV, 2003, WAT QUAL ASS UPP LIT; *WHO, 1989, HLTH GUID US WAT AGR27282
Do Debit Flows Crowd out Equity Flows or the other way Round?
No full textIn the presence of asymmetric information, the stage at which financing decisions are made about investment projects in a small open economy is crucial for the composition of international capital inflows as well as for the efficiency of channeling savings into investment. This paper compares the implications of two extreme cases regarding the information possessed by the firms at their financing stage for whether inflows of foreign debt may crowd out foreign equity or the other way round. The scope for corrective tax policies is examined. We also provide a welfare comparison between the two mechanisms of capital flows.debt and equity flows; asymmetric information; bankruptcy costs; market failures; corrective taxation
Do Debt Flows Crowd Out Equity Flows Or the Other Way Round?
No full textIn the presence of asymmetric information, the stage at which financing decisions are made about investment projects in a small open economy is crucial for the composition of international capital inflows as well as for the efficiency of channeling savings into investment. This paper compares the implications of two extreme cases regarding the information possessed by the firms at their financing stage for whether inflows of foreign debt may crowd out foreign equity or the other way round. The scope for corrective tax policies is examined. We also provide a welfare comparison between the two mechanisms of capital flows.
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