bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geologic and Hydrologic Factors Controlling Radon‐222 in Ground Water in Maine
Authors: Brutsaert Willem F. , Norton Stephen A. , Hess Charles T. , Williams John S. 
Published: July 2006

ABSTRACTHigh Radon‐222 (222Rn) concentrations exist in ground water from most granitic rocks in Maine. Some values exceed the suggested limit of 500 pCi/1 (E.P.A., 1976) by more than 100 times. Although high values (x̄= 22,100 pCi/1) are conclusively linked with the granites, high values are also present in ground water in metasedimentary rocks from sillimanite‐ (x̄= 13,630 pCi/1) and sillimanite‐orthoclase zone metamorphic terrains. Metamorphic (anatectic) pegmatites with hydrothermally introduced uranium are thought to be the source of radon in high grade terrain. At lower grade (chlorite to staurolite), no relationship exists between 222Rn content and metamorphic grade, although each rock formation has a somewhat characteristic 222Rn range from ground water, ranges which overlap. Considerable local 222Rn variations exist within the same rock body, reflecting local geologic and hydrologic conditions. Data on well depth, type of well, well yield, overburden type and thickness, and water chemistry show that 222Rn may increase slightly with well depth up to 50 to 75 m and is essentially constant thereafter. Low yield wells, generally associated with areas of thin overburden, tend to have higher 222Rn values than high yield wells, normally associated with thick sand and gravel overburdens. 222Rn concentrations decrease with increasing sodium concentrations, suggesting that low 222Rn wells are closely linked with surface waters. No other chemical parameter (Na, K, Ca, Mg, Fe, Mn, Zn, and Cu) correlates with 222Rn content within a single rock unit.
Hydrodynamic Response of Nakhon Luang Aquifer, Bangkok, Thailand
Authors: Das Gupta A. , Siddique M. 
Published: July 2006

ABSTRACTThe development of ground‐water resources in the Bangkok Metropolis over the last decades in an unplanned manner has resulted in a continual decline of the piezometric head in three aquifers underlying the city. One of these three aquifers identified as Nakhon Luang Aquifer provides the major portion of the ground‐water supply and has been considered for analyzing the hydrodynamic behavior under different operating schemes.It is predicted that continuation of the present rate of water withdrawal will result in a severe decline of the piezometric head, and by the year 2000 most of the public supply wells will no longer be in operation due to water level decline below the maximum depth provided for pump installation. Governmental authorities are actively considering the possibilities of increasing supply from surface‐water sources so that the ground‐water use can be phased out. A need to adopt policies to control the private and industrial usage of ground water in order to maintain its future availability is indicated.
Aquifer Decontamination for Volatile Organics: A Case History
Authors: Althoff William F. , Cleary Robert W. , Roux Paul H. 
Published: July 2006

ABSTRACTOrganic solvents, including 1,1,1‐trichloroethane at concentrations up to 40,000 ppb, were detected in the Old Bridge aquifer under an industrial plant in South Brunswick Township, New Jersey. A hydrogeologic investigation defined the ground‐water flow system and a plume of contamination which extended, at a concentration of at least 100 ppb, for a distance of about 1000 feet down‐gradient of the plant. A contamination abatement system was designed and installed to prevent this plume from reaching a municipal well located about 2500 feet from the site. The system includes seven extraction wells and a water treatment facility. The locations of the extraction wells and their combined pumping rate were determined in part by a computer simulation of the aquifer, which was subsequently checked by a 20‐day pumping test of the system. The on‐site treatment facility uses two cooling towers in series to air‐strip the volatile organics, and two infiltration ponds to return the treated water to the aquifer. The abatement system has been operating for about 10 months. Ground‐water monitoring results show that the plume is now significantly smaller and less concentrated than before the abatement system was installed. It is projected that in several years the aquifer will be largely decontaminated.
Estimating Aquifer Parameters for Large‐Diameter Wells
Authors: Rushton K. R. , Holt Sarah M. 
Published: July 2006

ABSTRACTTwo alternative methods of analyzing the response of large‐diameter wells are considered—the curve matching technique based on analytical solutions and the use of a numerical model. For ideal situations the methods give the same results but for unconfined aquifers where the decrease in saturated depth is significant, the curve matching technique is unreliable. Two particular examples are considered in detail. In a confined aquifer, where the diameter of the dug portion of the well is much larger than the diameter of the hole bored through the confined stratum, the response is found to be particularly sensitive to the ratio of these diameters. In an unconfined aquifer test, the important feature is the reduction in abstraction rate as the well is emptied. For each example, the recovery data is of critical importance in analyzing the tests.
The Use of Geologic, Hydrologic, and Geochemical Mapping Techniques in Environmental Assessmenta
Authors: Coe Curtis J. 
Published: July 2006

ABSTRACTA method of researching data at a mine to determine the environmental and economic impact to the operator has been developed. This method consists of developing geologic, hydrologic, and geochemical maps that can be used to provide a three‐dimensional view of the subsurface environment before, during, and after mining.The following maps were developed: a standard topographic base map, structure contour maps, static water level maps, and several iso‐concentration maps for pH, iron, manganese, sulfate, and specific conductance. Where possible geologic‐hydrologic cross sections were drawn to aid in the environmental interpretations. It is possible to use the data to develop the best possible mining plan for a geologic region which considers geographic, technical, economic, and environmental parameters. The iso‐concentration maps for a proposed surface mine site can be used to define the extent of concentration fields, point source locations, and concentration gradients.To demonstrate the use and interpretations of the data provided by this method, the results of two mine site case studies are presented that will discuss: (1) Dewatering problems; (2) Mining recharge areas; (3) Mining coal overlain by an acid overburden; and (4) The impact of prior surface mining.
Management of Ground Water Contaminated by Aromatic Hydrocarbons in the Aquifer Supplying Ames, Iowa
Authors: Yazicigil Hasan , Sendlein Lyle V. A. 
Published: July 2006

ABSTRACTA digital model of a buried channel aquifer contaminated by hydrocarbons is used to evaluate development alternatives. The response to ground‐water pumping is critical because the hydrocarbons cause taste and odor problems. The source of contamination is an abandoned pit used to dispose of coal tar residues from an old coal‐gas plant. The hydrocarbon residues overflowed the pit, migrated a short distance and seeped into flood plain soils. The downward movement of the hydrocarbons stopped at the water table but some dissolved into the ground water. Three general approaches taken to evaluate management alternatives include: (1) regulation of pumping of the city wells and of drawdown, and recovery periods are considered and the model stressed with various pumping rates and times; (2) construction of a pumping trough barrier is considered and a hypothetical control well is simulated; (3) new well field developments in various locations are considered. Results suggest that there is no way to prevent movement of contaminants to the well field. The only feasible solution is the removal of coal tar residues from the source area and construction of a pumping trough barrier.
Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis in the cavalier King Charles spaniel
Authors: Barnett K. C. 
Published: July 2006

Objectives: To record a previously unreported congenital and hereditary condition affecting the eyes and skin in the cavalier King Charles spaniel. Methods: Nineteen cases (13 litters) were investigated, with particular reference to eye and skin clinical signs. In addition, five generation pedigrees were obtained and studied from all cases with the exception of one. Results: The eye signs were due to keratoconjunctivitis sicca, a common ocular disease in the dog, but rarely of congenital origin. The skin signs were of an ichthyosiform dermatosis; ichthyosis being a rare skin disease in the dog. In human beings, ichthyosis is a similar disease, mainly inherited and with a neonatal onset, and sometimes accompanied by other developmental defects. In the cavalier King Charles spaniel, the coat abnormality was noted at birth by the breeders as a ‘curly coat’, with deterioration of the skin signs as the animal became adult. Clinical Significance: These two conditions occurring together in this breed is well recognised by some breeders but rarely by the veterinary profession. Successful treatment is not possible, although some improvement, particularly of the keratoconjunctivitis sicca, can be obtained. The probable hereditary nature of the condition is an important factor for control.
The Effect of Inertia on Radial Flows—Application to Hydrostatic Seals
Authors: Brunetière Noël , Tournerie Bernard 
Published: July 2006

AbstractA theoretical study of thin fluid film flows between rotating and stationary disks is presented. Inertia terms are included using an averaged method. It is assumed that inertia effects do not influence the shape of velocity profiles. It is shown that this assumption applies in many cases encountered in fluid film lubrication. The model is validated by comparison with experimental data and previous theoretical studies. A thermoelastohydrodynamic analysis of a hydrostatic seal is performed. The substantial influence of inertia terms on leakage rate prediction is demonstrated.
Squeeze Effects in a Flat Liquid Bridge Between Parallel Solid Surfaces
Authors: Meurisse Marie-Hélène , Querry Michel 
Published: July 2006

Abstract
When a liquid lubricant film fractionates into disjointed liquid bridges, or a unique liquid bridge forms between solid surfaces, capillary forces strongly influence the action of the fluid on the solid surfaces. This paper presents a theoretical analytical model to calculate the normal forces on the solid surfaces when squeezing a flat liquid bridge. The model takes into account hydrodynamic and capillary effects and the evolution of the geometry of the liquid bridge with time. It is shown that the global normal force reverses during the squeezing motion except in the case of perfect nonwetting; it is attractive at the beginning of the squeezing motion, and becomes repulsive at small gaps. When the external load is constant, capillary suction tends to accelerate the decrease in gap dramatically.
Approximate Analytical Model for Hertzian Elliptical Contact
Problems
Authors: Antoine J-F. , Visa C. , Sauvey C. , Abba G. 
Published: July 2006

Abstract
In rolling bearing analysis Hertzian contact theory is used to compute local contact stiffness. This theory does not have a closed form analytical solution and requires numerical calculations to obtain results. Using approximations of elliptical functions and with a mathematical study of Hertzian results, an empirical explicit formulation is proposed in this paper and allows us to obtain the dimensions, the displacement, and the contact stress with at least 0.003% precision and it can be applied to a large range of ellipticity of the contact surface.
Enhancement of In Vitro Growth of Pathogenic Bacteria by Norepinephrine: Importance of Inoculum Density and Role of Transferrin
Authors: O'Donnell Phyllis M. , Aviles Hernan , Lyte Mark , Sonnenfeld Gerald 
Published: July 2006

ABSTRACT
Norepinephrine is a stress hormone that enhances bacterial growth. We examined the effects of a small inoculum on the norepinephrine-induced growth of species previously reported to be unaffected by norepinephrine. The results indicated that a reduced inoculum density is essential for observing norepinephrine-induced effects. Additional studies using serum-free media suggested that transferrin plays a role in norepinephrine-induced growth.
Method for Assessment of Viability and Morphological Changes of Bacteria in the Early Stage of Colony Formation on a Simulated Natural Environment
Authors: Shimomura Yumi , Ohno Ryuzo , Kawai Fusako , Kimbara Kazuhide 
Published: July 2006

ABSTRACT

A quantitative analysis of changes in the physiological status of bacterial cells is a fundamental type of study in microbiological research. We devised a method for measuring the viability of bacteria in the early stage of colony formation on a simulated natural environment. In this method, a solid medium containing soil extract was used, and the formation of bacterial microcolonies on a membrane filter was determined by use of a laser scanning cytometer combined with live-dead fluorescent dyes. A polychlorinated biphenyl degrader,
Comamonas testosteroni
TK102, was used in this study. Surprisingly, approximately 20% of the microcolonies had their growth stopped and eventually died. In the presence of biphenyl, the growth arrest was increased to 50%, and filamentous cells were observed in the colonies. Predicted intermediate metabolites of biphenyl were added to the medium to determine the relationship between the change of viability and the production of metabolites, and the addition of 2,3-dihydroxybiphenyl showed low viability. The arrest was not observed to occur on nutrient-rich medium, suggesting that the change in viability might occur in a nutrient-poor natural condition. The results of this study demonstrated that toxic metabolites of xenobiotics might change cell viability in the natural environment.
Cladophora
(Chlorophyta) spp. Harbor Human Bacterial Pathogens in Nearshore Water of Lake Michigan
Authors: Ishii Satoshi , Yan Tao , Shively Dawn A. , Byappanahalli Muruleedhara N. , Whitman Richard L. , Sadowsky Michael J. 
Published: July 2006

ABSTRACT

Cladophora glomerata
, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently,
Cladophora
has been shown to harbor high densities of the fecal indicator bacteria
Escherichia coli
and enterococci.
Cladophora
may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached
Cladophora
, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing
Escherichia coli
(STEC),
Salmonella
,
Shigella
, and
Campylobacter
. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. While
Shigella
and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of
Salmonella
in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 × 10
3
cells per g
Cladophora
. Similarly, these PCR methods allowed enumeration of up to 5.4 × 10
2
Campylobacter
cells/g
Cladophora
in 60 to 100% of lake- and ditchside samples. The
Campylobacter
densities were significantly higher (P < 0.05) in the lakeside
Cladophora
samples than in the ditchside
Cladophora
samples. DNA fingerprint analyses indicated that genotypically identical
Salmonella
isolates were associated with geographically and temporally distinct
Cladophora
samples. However,
Campylobacter
isolates were genetically diverse. Since animal hosts are thought to be the primary habitat for
Campylobacter
and
Salmonella
species, our results suggest that
Cladophora
is a likely secondary habitat for pathogenic bacteria in Lake Michigan and that the association of these bacteria with
Cladophora
warrants additional studies to assess the potential health impact on beach users.
Diversity ofPlanctomycetesin Soil in Relation to Soil History and Environmental Heterogeneity
Authors: Buckley Daniel H. , Huangyutitham Varisa , Nelson Tyrrell A. , Rumberger Angelika , Thies Janice E. 
Published: July 2006

ABSTRACTMembers of thePlanctomycetes, which were once thought to occur primarily in aquatic environments, have been discovered in soils on five continents, revealing that theseBacteriaare a widespread and numerically abundant component of microbial communities in soil. We examined the diversity ofPlanctomycetesin soil samples obtained from experimental plots at an agricultural site in order to assess the extent ofPlanctomycetesdiversity in soil, to determine whether management effects such as past land cover and compost addition affected the composition of thePlanctomycetescommunity, and to determine whether the observations made could provide insight into the ecological distribution of these organisms. Analysis ofPlanctomycetes16S rRNA gene sequences revealed a total of 312 ± 35 unique phylotypes in the soil at the site examined. The majority of thesePlanctomycetessequences were unique, and the sequences had phylogenetic affiliations that included all major lineages in thePlanctomycetaceae, as well as several novel groups of deeply divergentPlanctomycetes. Both soil management history and compost amendment had significant effects on thePlanctomycetesdiversity, and variations in soil organic matter, Ca2+content, and pH were associated with variations in thePlanctomycetescommunity composition. In addition,Planctomycetesrichness increased in proportion to the area sampled and was correlated with the spatial heterogeneity of nitrate, which was associated with the soil management history at the orchard site examined. This report provides the first systematic assessment of the diversity ofPlanctomycetesin soil and also provides evidence that the diversity of this group increases with area as defined by the general power law description of the taxon-area relationship.
Characterization of Emetic
Bacillus weihenstephanensis
, a New Cereulide-Producing Bacterium
Authors: Thorsen Line , Hansen Bjarne Munk , Nielsen Kristian Fog , Hendriksen Niels Bohse , Phipps Richard Kerry , Budde Birgitte Bjørn 
Published: July 2006

ABSTRACT

Cereulide production has until now been restricted to the species
Bacillus cereus.
Here we report on two psychrotolerant
Bacillus weihenstephanensis
strains, MC67 and MC118, that produce cereulide. The strains are atypical with regard to pheno- and genotypic characteristics normally used for identification of emetic
B. cereus
strains. MC67 and MC118 produced cereulide at temperatures of as low as 8°C.
Further Comparison of Temperature Effects on Growth and Survival of
Clostridium perfringens
Type A Isolates Carrying a Chromosomal or Plasmid-Borne Enterotoxin Gene
Authors: Li Jihong , McClane Bruce A. 
Published: July 2006

ABSTRACT

Clostridium perfringens
type A isolates can carry the enterotoxin gene (
cpe
) on either their chromosome or a plasmid, but food poisoning isolates usually have a chromosomal
cpe
gene. This linkage between chromosomal
cpe
isolates and food poisoning has previously been attributed, at least in part, to better high-temperature survival of chromosomal
cpe
isolates than of plasmid
cpe
isolates. In the current study we assessed whether vegetative cells and spores of chromosomal
cpe
isolates also survive better than vegetative cells and spores of plasmid
cpe
isolates survive when the vegetative cells and spores are subjected to low temperatures. Vegetative cells of chromosomal
cpe
isolates exhibited about eightfold-higher decimal reduction values (D values) at 4°C and threefold-higher D values at −20°C than vegetative cells of plasmid
cpe
isolates exhibited. After 6 months of incubation at 4°C and −20°C, the average log reductions in viability for spores of plasmid
cpe
isolates were about fourfold and about threefold greater, respectively, than the average log reductions in viability for spores from chromosomal
cpe
isolates.
C. perfringens
type A isolates carrying a chromosomal
cpe
gene also grew significantly faster than plasmid
cpe
isolates grew at 25°C, 37°C, or 43°C. In addition, chromosomal
cpe
isolates grew at higher maximum and lower minimum temperatures than plasmid
cpe
isolates grew. Collectively, these results suggest that chromosomal
cpe
isolates are commonly involved in food poisoning because of their greater resistance to low (as well as high) temperatures for both survival and growth. They also indicate the importance of proper low-temperature storage conditions, as well as heating, for prevention of
C. perfringens
type A food poisoning.
Phase-Variable Surface Structures Are Required for Infection of
Campylobacter jejuni
by Bacteriophages
Authors: Coward Chris , Grant Andrew J. , Swift Craig , Philp Jennifer , Towler Rebecca , Heydarian Mohammad , Frost Jennifer A. , Maskell Duncan J. 
Published: July 2006

ABSTRACT

This study characterizes the interaction between
Campylobacter jejuni
and the 16 phages used in the United Kingdom typing scheme by screening spontaneous mutants of the phage-type strains and transposon mutants of the sequenced strain NCTC 11168. We show that the 16 typing phages fall into four groups based on their patterns of activity against spontaneous mutants. Screens of transposon and defined mutants indicate that the phage-bacterium interaction for one of these groups appears to involve the capsular polysaccharide (CPS), while two of the other three groups consist of flagellatropic phages. The expression of CPS and flagella is potentially phase variable in
C. jejuni
, and the implications of these findings for typing and intervention strategies are discussed.
Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from Hydrothermal Vent Fields in the Eastern Pacific Ocean
Authors: Csotonyi Julius T. , Stackebrandt Erko , Yurkov Vladimir 
Published: July 2006

ABSTRACT

This paper reports the discovery of anaerobic respiration on tellurate by bacteria isolated from deep ocean (1,543 to 1,791 m) hydrothermal vent worms. The first evidence for selenite- and vanadate-respiring bacteria from deep ocean hydrothermal vents is also presented. Enumeration of the anaerobic metal(loid)-resistant microbial community associated with hydrothermal vent animals indicates that a greater proportion of the bacterial community associated with certain vent fauna resists and reduces metal(loid)s anaerobically than aerobically, suggesting that anaerobic metal(loid) respiration might be an important process in bacteria that are symbiotic with vent fauna. Isolates from Axial Volcano and Explorer Ridge were tested for their ability to reduce tellurate, selenite, metavanadate, or orthovanadate in the absence of alternate electron acceptors. In the presence of metal(loid)s, strains showed an ability to grow and produce ATP, whereas in the absence of metal(loid)s, no growth or ATP production was observed. The protonophore carbonyl cyanide
m
-chlorophenylhydrazone depressed metal(loid) reduction. Anaerobic tellurate respiration will be a significant component in describing biogeochemical cycling of Te at hydrothermal vents.