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Influence of natural heterogeneity on the efficiency of chemical floods in source zones.

Several technologies for cleaning up DNAPLs in source zones rely on solubilizing contaminants or destroying them in situ. Typically, these approaches employ an injection/withdrawal system to recirculate this treatment fluids. Our interest is in examining factors that influence delivery efficiency. Although many factors can affect this efficiency, this study looks at the combined influence of density-driven flow and porous media heterogeneities. The analysis is based on a series of numerical simulations of hypothetical chemical floods (e.g., potassium permanganate), which are highly resolved in space and time with a scale that is typical of field installations. Results indicate that the characteristics of convective mixing, i.e., natural, forced, and mixed convection, greatly affect delivery efficiency and patterns of mass transport. The ratio of the Grashof number (Gr) and Reynolds number (Re) proved useful in interpreting the patterns of flooding in a homogeneous porous medium. When higher-permeability layers are included in the domain, they act as conduits, effectively expediting the transport of treatment chemicals from injection to recovery wells. These large fluxes of chemicals in the high-permeability layers produce significant flooding inefficiencies. The problem is less severe in heterogeneous medium where the connectivity through the treatment zone is less well developed. Overall, this paper illustrates that density effects and high-permeability pathways need to be considered in designing chemical floods.

Disasters↗

Measurement of hepatic protein synthesis in unrestrained mice-evaluation of the 'flooding technique'.

Controversy exists regarding the validity of various techniques for estimating rates of protein synthesis in vivo. In the present report, we have compared estimates of hepatic protein synthesis in normal mice with a pulse labelling of [1-14C]leucine and calculated hepatic protein synthetic rates in a conventional two-pool model and in a five-pool compartment analysis. Results obtained with pulse labelling were also compared to those obtained in animals receiving a flooding dose of 1.5 mumol L-phenylalanine and 0.4 microCi [U-14C]phenylalanine per gram of body weight or 1.0 mumol L-leucine and 0.4 microCi [l-14C]leucine per gram of body weight. Estimates of protein synthesis were calculated with plasma free amino acid, liver acid-soluble fraction and acylated tRNA specific radioactivities as being representative of the precursor pool for protein synthesis. Rates of hepatic protein synthesis obtained with pulse labelling and either leu-tRNA or acid-soluble fractions of liver leucine as the precursor for protein synthesis gave similar results (37 +/- 5 vs 42 +/- 5% per day) in a two-pool model, but disagreed in a five-pool model (37 +/- 5 vs 6 +/- 2% per day). Estimates based on plasma enrichment in leucine were only one fifth of values obtained with tRNA in labelling experiments. When the plasma pool with tracer amino acids was used to indicate the precursor labelling of protein synthesis, values obtained with the flooding dose of either phenylalanine or leucine agreed with those obtained with pulse labelling and enrichment in tRNA (30 +/- 3 nmol min-1 vs 28 +/- 4 nmol min-1); with however no agreement when the enrichment in the liver mixed tissue pool was used (76 +/- 5 nmol min-1). Complete equilibration of the amino acid pools did not occur despite flooding. Therefore, the flooding technique may only represent an approximate method to measure protein synthesis in vivo, although it gives absolute values that agree well with results from labelling techniques based on tRNA enrichment provided the plasma pool is used as the precursor enrichment.

Amino Acids↗

Virus movement in soil columns flooded with secondary sewage effluent.

Secondary sewage effluent containing about 3 X 10(4) plaque-forming units of polio virus type 1 (LSc) per ml was passed through columns 250 cm in length packed with calcareous sand from an area in the Salt River bed used for ground-water recharge of secondary sewage effluent. Viruses were not detected in 1-ml samples extracted from the columns below the 160-cm level. However, viruses were detected in 5 of 43 100-ml samples of the column drainage water. Most of the viruses were adsorbed in the top 5 cm of soil. Virus removal was not affected by the infiltration rate, which varied between 15 and 55 cm/day. Flooding a column continuosly for 27 days with the sewage water virus mixture did not saturate the top few centimeters of soil with viruses and did not seem to affect virus movement. Flooding with deionized water caused virus desorption from the soil and increased their movement through the columns. Adding CaCl2 to the deionized water prevented most of the virus desorption. Adding a pulse of deionized water followed by sewage water started a virus front moving through the columns, but the viruses were readsorbed and none was detected in outflow samples. Drying the soil for 1 day between applying the virus and flooding with deionized water greatly reduced desorption, and drying for 5 days prevented desorption. Large reductions (99.99% or more) of virus would be expected after passage of secondary sewage effluent through 250 cm of the calcareous sand similar to that used in our laboratory columns unless heavy rains fell within 1 day after the application of sewage stopped. Such virus movement could be minimized by the proper management of flooding and drying cycles.

Adsorption↗

Effects of flooding amino acids on incorporation of labeled amino acids into human muscle protein.

We investigated the effects of the nature of the flooding amino acid on the rate of incorporation of tracer leucine into human skeletal muscle sampled by biopsy. Twenty-three healthy young men (24.5 +/- 5. 0 yr, 76.2 +/- 8.3 kg) were studied in groups of four or five. First, the effects of flooding with phenylalanine, threonine, or arginine (all at 0.05 g/kg body wt) on the incorporation of tracer [13C]leucine were studied. Then the effects of flooding with labeled [13C]glycine [0.1 g/kg body wt, 20 atoms percent excess (APE)] and [13C]serine (0.05 g/kg body wt, 15 APE) on the incorporation of simultaneously infused [13C]leucine were investigated. When a large dose of phenylalanine or threonine was administered, incorporation of the tracer leucine was significantly increased (from 0.036 to 0. 067 %/h and 0.037 to 0.070 %/h, respectively; each P < 0.01). However, when arginine, glycine, or serine was administered as a flooding dose, no stimulation of tracer leucine incorporation could be observed. These results, together with those previously obtained, suggest that large doses of individual essential, but not nonessential, amino acids are able to stimulate incorporation of constantly infused tracer amino acids into human muscle protein.

Adult↗

Aminoacyl-tRNA and tissue free amino acid pools are equilibrated after a flooding dose of phenylalanine.

The flooding dose method, which is used to measure tissue protein synthesis, assumes equilibration of the isotopic labeling between the aminoacyl-tRNA pool and the tissue and blood free amino acid pools. However, this has not been verified for a phenylalanine tracer in an in vivo study. We determined the specific radioactivity of [(3)H]phenylalanine in the aminoacyl-tRNA and the tissue and blood free amino acid pools of skeletal muscle and liver 30 min after administration of a flooding dose of phenylalanine along with [(3)H]phenylalanine. Studies were performed in neonatal pigs in the fasted and refed states and during hyperinsulinemic-euglycemic-amino acid clamps. The results showed that, 30 min after the administration of a flooding dose of phenylalanine, there was equilibration of the specific radioactivity of phenylalanine among the blood, tissue, and tRNA precursor pools. Equilibration of the specific radioactivity of the three precursor pools for protein synthesis occurred in both skeletal muscle and liver. Neither feeding nor insulin status affected the aminoacyl-tRNA specific radioactivity relative to the tissue free amino acid specific radioactivity. The results support the assumption that the tissue free amino acid pool specific radioactivity is a valid measure of the precursor pool specific radioactivity and thus can be used to calculate protein synthesis rates in skeletal muscle and liver when a flooding dose of phenylalanine is administered.

Amino Acids↗

Pulmonary vascular extraction and distribution of antipyrine with alveolar flooding.

Transport characteristics of antipyrine (AP), 22Na+, and tritiated water (THO) were assessed in dog lungs by multiple indicator-dilution experiments in vivo with anesthesia and in isolated perfused preparations before and after alveolar flooding. In controls, outflow patterns of AP and THO were nearly identical. In flooding, AP and THO patterns separated. THO upslopes decreased and mean (t) and modal (tmax) transit times increased as flooding increased; AP initial upslopes remained relatively unchanged but t increased, whereas tmax decreased. Patterns of 22Na+ were unchanged. The results indicate 22Na+ limitation at the endothelium, AP limitation only at the epithelium, and no THO limitation. A mathematical model is based on axial and orthogonal distribution of AP and THO. With alveolar flooding, diffusional distance may be a limiting factor in this distribution.

Animals↗

Different medical needs between hurricane and flood victims.

OBJECTIVE: Through the review of patient records seen by the New Mexico-1 Disaster Medical Assistance Team (NM-1DMAT) after various disasters, we hoped to find patterns that might help in disaster planning. Our hypothesis was that flood and hurricane victims have different medical conditions and needs. METHODS: We conducted a retrospective review of patient records for NM-1DMAT deployments to Hurricane Andrew in Florida (August 1992) and the Houston, TX flood caused by Tropical Storm Allison (June 2001). We compared age, gender, chief complaint, medical history, diagnosis, diagnostic testing, treatment rendered, triage category, and patient disposition. RESULTS: We found several differences between the patients presenting after Hurricane Andrew and those presenting after Tropical Storm Allison. The chief complaint, diagnosis, presence of medical history, diagnostic testing, treatment rendered, triage category, and disposition all differed between the 2 disasters. The mean ages in both groups were similar. CONCLUSIONS: The needs of the patients differed in several areas between Hurricane Andrew and the Houston flood. This information should be tested in a future hurricane or flood and taken into account when planning for deployments.

Adult↗

Flooded native pastures of the northern region of the Pantanal of Mato Grosso: biomass and primary productivity variations.

The Pantanal comprises a number of landscape units, submitted to a flood pulse with variable intensity or regularity. One of these units, the flooded plains, is important in cattle raising. This study was carried out in the northern portion of the Pantanal and presents data related to the productive dynamics of the flooded native pastures both protected from and exposed to cattle. The greatest total biomass values were for the protected pasture due to accumulated dead biomass. Net primary production presented smaller values at the flood-season start and increasing gradually beginning in the subsequent rainy season. However, consumption by cattle was also more intense during the months of greater precipitation. The effect of cattle in pastures is of fundamental importance to management since it prevents the dead biomass excess that increases fire risks.

Animal Feed↗

The importance of fires and floods on tree ages along mountainous gravel-bed streams.

This paper examines the commonly accepted assumption in the riparian literature that areas adjacent to streams do not burn. Using time-since-fire distributions, derived from stand-origin maps for a watershed in the front ranges of the Canadian Rocky Mountains, we found that the areas adjacent to streams and the whole study watershed have similar fire frequencies. In addition, the relative importance of fires and floods is regulated by a change in channel morphology associated with the creation of bars. The results demonstrate that fires solely control tree establishment along straight streams without bars, while the influence of floods is observed at the onset of lateral- and point-bar formation. This occurs because bars are formed in-channel and require smaller discharges in order to be flooded, compared to higher terraces. Consequently, bars are the only surfaces being flooded more frequently than they are being burned. Thus, overall the results indicate that, on this watershed, areas adjacent to streams are not less likely to burn than the uplands, except for lateral and point bars. The generality of these results to other systems should be tested as they have important implications for current forest ecological definition of "riparian zones," which typically include all fluvially derived landforms, from the channel banks to the terraces. Indeed, this study suggests that along smaller, headwater, gravel-bed mountain watersheds, the forests found on terraces are only influenced by fire and not fluvial processes and should therefore not be included in the riparian zone, while the forests on bars are the only surfaces currently being influenced by fluvial processes. Such a change in definition has implications for both ecologists and forest managers aiming to protect areas along streams as they now must take into account the effects of two disturbances on these small gravel-bed streams.

Conservation of Natural Resources↗

Phosphate release from seasonally flooded soils: a laboratory microcosm study.

Phosphorus derived from agricultural practices has been targeted as a leading cause of water quality degradation in Lake Champlain. Mobilization of P from seasonally flooded agricultural soils is a concern. Using 14 soils from a research farm in New York's Champlain Valley, we characterized the available P status, extractable Fe and Al, P sorption capacities, and soluble phosphate release in flooded laboratory microcosms. Quantities of NH4-acetate available P ranged from 3 to 100 mg kg(-1) and fluoride-extractable P from 10 to 211 mg kg(-1). Flooding soils induced significant release of phosphate to the porewater over a 60- to 90-d period in 13 of the 14 soils studied. Porewater phosphate increases ranged from 2.2 to 27.0 times the initial phosphate concentrations. However, floodwater phosphate increases were much lower, with a maximum of 3.6 times the initial concentration. Average porewater phosphate concentrations over the flooding period ranged from 0.046 to 7.0 mg L(-1) and average floodwater P from 0.032 to 3.70 mg L(-1). Ammonium-acetate P and the degree of phosphorus saturation (DPS) were highly correlated with the average porewater and floodwater phosphate concentration. Average ratio of porewater to floodwater phosphate concentrations ranged from 1.0 to 3.3. Five soils that were lower in fluoride-extractable P had increasing porewater phosphate accompanied by increasing porewater Fe2+ and decreasing floodwater phosphate. Results suggest that P solubility and mobility were a function of both the available P status and redox cycling.

Agriculture↗

Some age-related effects of the 1974 Brisbane floods.

Some age-related effects of the 1974 Brisbane floods are examined. The impact of the floods on health increased in those over 35 years of age probably because they were more likely to be householders. Women under 65 years of age had more psychiatric symptoms than men, but this sex difference disappeared in those over 65 years, perhaps because the working man is not constantly confronted with the damage to his home in the way that others are. The possibility that people over 75 years living in flood-affected suburbs experienced increased morbidity even though not themselves flooded cannot be excluded.

Adolescent↗

[The analysis of the course of pregnancy, delivery and postpartum among women touched by flood disaster in Kotlin Kłodzki in July 1997].

OBJECTIVES: A natural disaster has been defined as a disruption of human ecology that exceeds the capacity of the community to function normally. Little is known about the influence of flood disaster on reproductive outcomes. DESIGN: This study reviews perinatal medical problems in pregnant women during the flood disaster from Kłodzko Region in July 1997. MATERIALS AND METHODS: 47 pregnant women were investigated which injured from the flood disaster. We observed a psychosocial stress in this women. A control random group consists of 100 pregnant women in 1996. RESULTS: Reproductive outcomes include pregnancy loss in 55.3% and other severe disorders: premature delivery, missed abortion, birth asphyxia, premature rupture of membranes, intrauterine growth retardation. CONCLUSIONS: Psychosocial stress observed during the flood disaster cause many perinatal complications and pregnancy loss. Intensive perinatal medical care must usually be provided from outside the disaster area.

Adolescent↗

After the flood. A strategic primary health care plan for homeless and migrant populations during an environmental disaster.

An environmental crisis, such as a flood, can significantly affect health care delivery and services in a community. Environmental disasters can be particularly devastating to already vulnerable populations such as the homeless and migrants, who, because of social, political, and economic constraints, experience special health care needs. In 1993, after Iowa experienced the worst flood in its history, President Clinton declared the entire state a federal disaster area. Later, the Iowa Department of Public Health received a federal grant to evaluate the health care delivered during the flood and develop a strategic plan to enhance primary health care for the homeless and migrant populations during future environmental disasters. The plan was based on data obtained during and after the flood in three critical areas--communication, health care delivery, and community. These areas were themes that emerged from a series of interviews with representatives from health care agencies and clients themselves. Each theme became the focus of specific, comprehensive recommendations and strategies to meet the daily challenges of the homeless and migrants, as well as to enhance the delivery of primary health care services in the future.

Disaster Planning↗

Flood disaster in the Czech Republic in July, 1997--operations of the emergency medical service.

This report is a review of the response and the activities of the Emergency Medical Services during a huge flood that devastated one-third of the territory of the Czech Republic in July 1997. The Emergency Medical Services personnel extracted by helicopter a great number of citizens who were trapped in their flats and homes. For diabetics and cardiacs who were isolated from the surface transport, the EMS personnel supplied necessary medication, and transported patients to hemodialysis. The cooperation between non-medical emergency services and the district crisis staff of the Integrated Rescue System, varied in different districts. However, in most flooded districts, the cooperation was satisfactory. In addition, a large number of volunteers helped in the first days of the flood. Unfortunately, 49 people died because of the flood. Nevertheless, since the EMS was able to manage the extraordinary needs, the number of emergencies and hospitalizations was low.

Czech Republic↗

[The scientific bases for determining the health losses of the affected population in catastrophic flooding].

The article focuses on methodological approaches to the determination of sanitary losses among population in a catastrophic flood. An emergency is considered that can arise in the destruction of the water-development project assemblies. The following items were taken account of in working out of the above approaches: population density in the territories found to be in the zone of flood: notification and evacuation of the population from the zone of catastrophe in a timely fashion, the distance from the site of formation of the wave of breaking to the populated locality, the height and velocity of the wave of breaking, time of the year and day of the catastrophe. Scientific and methodological approaches and the mathematical model "Povin'" ("Flood") developed with the aid of such approaches permit analyzing the situation having presented itself, working out administrative decisions for the territorial public health services directing bodies to be taken in the current situation, instituting measures designed to eliminate medicosanitary effects of the catastrophic flood within the shortest time possible.

Disaster Planning↗

[Post-traumatic stress disorder. After the flood in Saguenay].

OBJECTIVE: To measure the prevalence of posttraumatic stress disorder and emotional distress among victims of the Saguenay flood compared with those who were not affected by the flood. DESIGN: Cross-sectional study using a telephone survey of victims and a control group. SETTING: Chicoutimi, Que. PARTICIPANTS: Sixty-two adults in a flooded area and a control group of 79 volunteers chosen randomly from an adjacent area. MAIN OUTCOME MEASURES: Diagnostic criteria for posttraumatic stress disorder measured using the Post-traumatic Stress Disorder Reaction Index and high scores on the Self-Reporting Questionnaire on emotional distress. RESULTS: Socially and demographically, study group and control group were comparable. Prevalence of posttraumatic stress disorder in the study group was close to 20% (odds ratio [OR] 6.08; 95% confidence interval [CI] 1.63 to 22.64). Prevalence of emotional distress in the study group was 29% (OR 2.42; 95% CI 1.04 to 5.61). CONCLUSION: The Saguenay flood caused psychological distress that was measurable 4 months later. Health care professionals should be aware of the psychological effects of natural disasters.

Adolescent↗

A study of intersectoral co-ordination in disaster management in flood prone districts of West Bengal.

Disaster management is essentially a multi-sectoral and multidisciplinary endeavor. The status of disaster preparedness, coordination among different sectors and its impact on disaster management performance were studied and compared in two flood prone comparable districts viz. Midnapore and Murshidabad of West Bengal. The perception of state level officers about important job responsibilities of other departments in relation to disaster management and its intersectoral co-ordination was found mostly satisfactory; but this desired status did not prevail at district level. Lack of co-ordination among some sectors at district levels persisted in Murshidabad district, indicating comparatively better intersectoral co-ordination in Midnapore district. Thus, 'early response following flood' the most important indicator of adequacy of pre-disaster preparedness was found significantly better in Midnapore district. On the contrary, due to liberal use of Radio transmission set for flood warning, a significantly higher proportion of affected families in Murshidabad district received early flood warning compared to Midnapore. Organisational aspects of disaster management need to be improvised with role clarity of different departments in relation to other sectors involved in this endeavor.

Disaster Planning↗

[Effect of flooding stress on transpiration of poplar I-69/55].

The rates of transpiration(Tr) and photosynthesis(Pn) of poplar I-69/55 trees were measured under flooding stress. Flooding stress caused Pn and Tr decreasing, while in the period of measurement, Pn almost didn't change. The longer the period of flooding stress was, the more the Tr and stomatal conductance (Gs) decreased. Undre no stress, Pn and Tr of test trees displayed daily double-peak curves and seasonal variations, with the maximum in summer. Water use efficiency also displayed seasonal variation, with the maximum in autumn. Under no stress, Tr obviously changed with tree ages, with the order of 1 year-old > 3 year-old > 7 year-old. The rate of Tr/Pn in spring, summer and autumn was higher than that of other deciduous broad-leaved trees in the same region, especially in summer. The high Tr/Pn ratio means a high water consumption, which is beneficial to water loss of poplar I-69/55. In shoal sites, the temperature of leaf surface in summer and autumn is the most important factor that affects the transpiration rate of poplar I-69/55, suggesting that decreasing the temperature of leaf suface is beneficial to increase the transpiration rate. During the two days after flooding, the temperature of leaf surface is still the important factor that affects transpiration rate.

Disasters↗