bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative frequency of peripheral odontogenic tumors: a study of 45 new cases and comparison with studies from the literature
Authors: Buchner Amos , Merrell Phillip W. , Carpenter William M.
Published: July 2006

Background:  Peripheral (extraosseous) odontogenic tumors are rare, and reports in the literature have mainly been single case reports or a small series of cases. The aim of this study was to determine the relative frequency of peripheral (extraosseous) odontogenic tumors relative to one another and relative to their central (intraosseous) counterparts in an oral pathology biopsy service and to compare these data with information available in the literature.

Methods:  The files of the Pacific Oral and Maxillofacial Pathology Laboratory of the University of the Pacific, San Francisco, CA, USA, served as the source of material for this study. Files were systematically searched for all cases of peripheral odontogenic tumors (POTs) during a 20‐year‐period.

Results:  There were 91 178 cases accessed in which central and POTs were identified in 1133 (1.24%), central tumors in 1088 (1.2%), and peripheral tumors in 45 (0.05%). Peripheral tumors accounted for 4% of all 1133 central and POTs. Peripheral odontogenic fibroma (PODF) was the most common of the 45 POTs accounting for 51.1% (23 cases) followed by peripheral ameloblastoma (PA) 28.9% (13 cases) and peripheral calcifying cystic odontogenic tumor (PCCOT) 13.3% (six cases). Peripheral calcifying epithelial odontogenic tumor, peripheral ameloblastic fibroma, and peripheral ameloblastic carcinoma were also identified – each comprised 2.2% (one case each). PODF was more common than its central counterpart by a 1.4:1 ratio. This was the only peripheral tumor that was more common than its central counterpart. PA accounted for 9.3% of all ameloblastomas and PCCOT for 26% of all calcifying cystic odontogenic tumors.

Conclusion:  There is only scarce information in the literature on the relative frequency of POTs. Additional studies should be conducted to determine the true relative frequency. To ensure accuracy, pathologists with experience in the field of odontogenic tumors should conduct these studies. Intraosseous tumors that perforate through the bone to the gingival tissue, clinically presenting as ‘peripheral tumors’ should be excluded.
Effect of photoperiod on the fish innate immune system: a link between fish pineal gland and the immune system
Authors: Ángeles Esteban M. , Cuesta Alberto , Rodríguez Alejandro , Meseguer José
Published: July 2006

Abstract:  The pineal gland via its secretory product, melatonin, influences the light–dark rhythm in most vertebrates including fish. Apart from the information concerning this circadian rhythm, the interrelation of the melatonin with other physiological processes has not been considered in fish. Thus, we evaluated the changes in the humoral innate immune system of seabream (Sparus aurata L.) and sea bass (Dicentrarchus labrax L.) specimens exposed to a constant light–dark photoperiod (12 hr L:12 hr D). Serum was obtained from blood samples collected at 02:00, 08:00 hr (light‐on), 14:00, 20:00 hr (light‐off) and at 08:00 hr again. Among the humoral innate immune responses, complement, lysozyme and peroxidase activities were determined. Complement activity was higher during the day than during the night in both fish species. Seabream lysozyme activity reached its maximum at 20:00 and 02:00 hr but was hardly affected in sea bass. Finally, the peroxidase activity of seabream was significantly higher at 08:00 hr than during the rest of the cycle while, in sea bass, it showed little variation. The present results demonstrate that the humoral innate immune system has a circadian rhythm based on the light–dark cycle and that this cycle might be affected by the pineal gland.
Maternal Employment in Childhood and Adults’ Retrospective Reports of Parenting Practices
Authors: Nomaguchi Kei M. , Milkie Melissa A.
Published: July 2006

Do adults’ perceptions of their mothers’ and fathers’ parenting practices in childhood vary by their mothers’ employment status? Among adults in the Survey of Midlife Development in United States who lived with 2 biological parents until the age of 16 years (N = 2,246), those who had employed mothers during most or all of their childhood reported less support and less discipline from both parents than those who had stay‐at‐home mothers. Sons but not daughters who had employed mothers reported more verbal or physical assaults by both parents than their counterparts who had homemaker mothers. Despite greater social acceptance of maternal employment among younger Americans, cohort differences were not evident. These findings underscore the significance of mothers’ economic roles in influencing offspring’s perceptions of family dynamics.
What Makes Someone Family? Adult Children’s Perceptions of Current and Former Stepparents
Authors: Schmeeckle Maria , Giarrusso Roseann , Feng Du , Bengtson Vern L.
Published: July 2006

This study examined the extent to which adult children perceived current and former, legal or cohabiting, partners of biological parents as family members and parents and determined what factors were associated with these perceptions. Data come from 443 adult children participating in the 1997 wave of the Longitudinal Study of Generations. Hypotheses were developed on the basis of a synthesis of the solidarity‐conflict model and the life course perspective. Results revealed diversity in adult children’s perceptions of family membership and parentage and support for the theoretical perspectives. Structural, associational, and normative solidarity were all associated with adult children’s perceptions of current and former stepparents as family members and parents. Substantive and theoretical implications are discussed.
Interracial and Intraracial Patterns of Mate Selection Among America’s Diverse Black Populations
Authors: Batson Christie D. , Qian Zhenchao , Lichter Daniel T.
Published: July 2006

Despite recent immigration from Africa and the Caribbean, Blacks in America are still viewed as a monolith in many previous studies. In this paper, we use newly released 2000 census data to estimate log‐linear models that highlight patterns of interracial and intraracial marriage and cohabitation among African Americans, West Indians, Africans, and Puerto Rican non‐Whites, and their interracial marriage and cohabitation with Whites. Based on data from several metropolitan areas, our results show that, despite lower socioeconomic status, native‐born African Americans are more likely than other Blacks to marry Whites; they also are more likely to marry other Black ethnics. West Indians, Africans, and Puerto Rican non‐Whites are more likely to marry African Americans than to marry Whites. Interracial relationships represent a greater share of cohabiting unions than marital unions. The majority of interracial unions, including native and immigrant Blacks, consist of a Black man and White woman. The implications for marital assimilation are discussed.
Cohesion and Enmeshment Revisited: Differentiation, Identity, and Well‐Being in Two European Cultures
Authors: Manzi Claudia , Vignoles Vivian L. , Regalia Camillo , Scabini Eugenia
Published: July 2006

We examined the nature and implications of family differentiation among adolescents facing a life transition in 2 European countries with differing family cultures. One hundred and twenty‐four Italian and 109 U.K. adolescents completed measures of family differentiation (cohesion and enmeshment), identity threat (perception of threat to the self associated with finishing school), life satisfaction, depressive symptoms, and anxiety. Confirmatory factor analyses showed that cohesion and enmeshment were distinguishable in both countries, orthogonal in the U.K. but positively correlated in Italy. Family cohesion was associated with better psychological well‐being in both countries; enmeshment was associated with poorer psychological well‐being in the U.K. but not in Italy. Structural equation models showed that effects on well‐being were fully mediated by identity threat in both cultures.
The Dyadic Adjustment Scale: A Reliability Generalization Meta‐Analysis
Authors: Graham James M. , Liu Yenling J. , Jeziorski Jennifer L.
Published: July 2006

We conducted a reliability generalization meta‐analysis to examine the internal consistency of Dyadic Adjustment Scale (DAS; Spanier, 1976) scores across 91 published studies with 128 samples and 25,035 participants. The DAS was found to produce total and Dyadic cohesion, Consensus, and Satisfaction scores of acceptable internal consistency, although lower than those originally reported by Spanier (1976). Reliability estimates of these scores did not differ by the sexual orientation, gender, marital status, or ethnicity of the sample. The Affective Expression subscale was found to produce scores with poor Cronbach’s alpha across studies. Reliability estimates of Affective Expression scores were highly influenced by sample characteristics. The implications of these results are discussed as they relate to the use of the DAS in research.
The Prevalence and Correlates of Multipartnered Fertility Among Urban U.S. Parents
Authors: Carlson Marcia J. , Furstenberg Frank F.
Published: July 2006

Recent trends in marriage and fertility have increased the number of adults having children by more than 1 partner, a phenomenon that we refer to as multipartnered fertility. This article uses data from the Fragile Families and Child Wellbeing Study to examine the prevalence and correlates of multipartnered fertility among urban parents of a recent birth cohort (N = 4,300). We find that unmarried parents are much more likely to have had a child by a previous partner than married parents. Also, race/ethnicity is strongly associated with multipartnered fertility, as is mothers’ young age at first birth, and fathers’ history of incarceration. To the extent that childrearing across households diminishes parental resources, multipartnered fertility has important consequences for children’s well‐being.
Inhibitory Effects of Cytostatically Active 6‐Aminobenzo[c]phenanthridines on Cytochrome P450 Enzymes in Human Hepatic Microsomes
Authors: Zebothsen Inga , Kunze Thomas , Clement Bernd
Published: July 2006

Abstract:Besides assays for the evaluation of efficacy new drug candidates have to undergo extensive testings for enhancement of pharmaceutical drug safety and optimization of application. The objective of the present work was to investigate the pharmacokinetic drug drug interaction potential for the cytostatically active 6‐aminobenzo[c]phenanthridines BP‐11 (6‐amino‐11,12‐dihydro‐11‐(4‐hydroxy‐3,5‐dimethoxyphenyl)benzo[c]phenanthridine) and BP‐D7 (6‐amino‐11‐(3,4,5‐trimethoxyphenyl)benzo[c]phenanthridine)in vitrothrough incubation with human hepatic microsomes and marker substrates. For these studies the cytochrome P‐450 isoenzymes and corresponding marker substrates recommended by the EMEA (The European Agency for the Evaluation of Medicinal Products) were chosen. In detail these selective substrates were caffeine (CYP1A2), coumarin (CYP2A6), tolbutamide (CYP2C9), S‐(+)‐mephenytoin (CYP2C19), dextromethorphane (CYP2D6), chlorzoxazone (CYP2E1) and testosterone (CYP3A4). Incubations with each substrate were carried out without a possible inhibitor and in the presence of a benzo[c]phenanthridine or a selective inhibitor at varying concentrations. Marker activities were determined by HPLC (high performance liquid chromatography). For the isoenzymes showing more than 50% inhibition by the addition of 20 μM BP‐11 or BP‐D7 additional concentrations of substrate and inhibitor were tested for a characterization of the inhibition. The studies showed a moderate risk for BP‐11 for interactions with the cytochrome P‐450 isoenzymes CYP1A2, CYP2C9, CYP2D6 and CYP3A4. BP‐D7, the compound with the highest cytotstatic efficacy, showed only a moderate risk for interactions with drugs, also metabolized by CYP3A4.
Effects of Volatile Constituents of Rosemary Extract on Lung Inflammation Induced by Diesel Exhaust Particles
Authors: Inoue Ken‐ichiro , Takano Hirohisa , Shiga Akira , Fujita Yoji , Makino Hiroaki , Yanagisawa Rie , Kato Yoji , Yoshikawa Toshikazu
Published: July 2006

Abstract: Epidemiological and experimental studies have implicated that diesel exhaust particles are involved in increases in morbidity and mortality from lung diseases. Recently, we have demonstrated that rosmarinic acid, a polyphenolic liquid component in perilla, inhibits lung inflammation induced by diesel exhaust particles in vivo, partly through its antioxidative property. We have also shown the antioxidative activities of volatile constituents of rosemary extract, the gaseous component in perilla, in vitro. The purpose of this study was to evaluate the effects of intratracheal administration of volatile rosemary extract on lung inflammation induced by diesel exhaust particles. ICR mice were treated with intratracheal administration of volatile rosemary extract before intratracheal exposure to diesel exhaust particles. Twenty‐four hr later, diesel exhaust particles exposure elicited lung inflammation characterized by the infiltration of neutrophils and eosinophils, which was confirmed by cellular profile of bronchoalveolar lavage fluid and histological examination. Diesel exhaust particles enhanced the protein expressions of interleukin‐1β, macrophage inflammatory protein‐1α, macrophage chemoattractant protein‐1, and keratinocyte chemoattractant in the lung. Pretreatment with rosemary extract significantly inhibited the diesel exhaust particles‐induced lung inflammation. Rosemary extract treatment also suppressed the diesel exhaust particles‐enhanced lung expression of macrophage inflammatory protein‐1α, macrophage chemoattractant protein‐1, and keratinocyte chemoattractant. These results suggest that intratracheal administration of rosemary extract can prevent lung inflammation induced by diesel exhaust particles. The preventive effect is mediated, at least partly, through the inhibition of the enhanced lung expressions of macrophage inflammatory protein‐1α, macrophage chemoattractant protein‐1, and keratinocyte chemoattractants.
Pioglitazone is Metabolised by CYP2C8 and CYP3A4 in vitro: Potential for Interactions with CYP2C8 Inhibitors
Authors: Jaakkola Tiina , Laitila Jouko , Neuvonen Pertti J. , Backman Janne T.
Published: July 2006

Abstract: Our objective was to identify the cytochrome P450 (CYP) enzymes that metabolise pioglitazone and to examine the effects of the CYP2C8 inhibitors montelukast, zafirlukast, trimethoprim and gemfibrozil on pioglitazone metabolism in vitro. The effect of different CYP isoform inhibitors on the elimination of a clinically relevant concentration of pioglitazone (1 μM) and the formation of the main primary metabolite M‐IV were studied using pooled human liver microsomes. The metabolism of pioglitazone by CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5 was investigated using human recombinant CYP isoforms. In particular, the inhibitors of CYP2C8, but also those of CYP3A4, markedly inhibited the elimination of pioglitazone and the formation of M‐IV by HLM. Inhibitors selective to other CYP isoforms had a minor effect only. Of the recombinant isoforms, CYP2C8 (20 pmol/ml) metabolised pioglitazone markedly (56% in 60 min.), and also CYP3A4 had a significant effect (37% in 60 min.). Montelukast, zafirlukast, trimethoprim and gemfibrozil inhibited pioglitazone elimination in HLM with IC50 values of 0.51 μM, 1.0 μM, 99 μM and 98 μM, respectively, and the formation of the metabolite M‐IV with IC50 values of 0.18 μM, 0.78 μM, 71 μM and 59 μM, respectively. In conclusion, pioglitazone is metabolised mainly by CYP2C8 and to a lesser extent by CYP3A4 in vitro. CYP2C9 is not significantly involved in the elimination of pioglitazone. The effect of different CYP2C8 inhibitors on pioglitazone pharmacokinetics needs to be evaluated also in vivo because, irrespective of their in vitro CYP2C8 inhibitory potency, their pharmacokinetic properties may affect the extent of interaction.
Ocelot (Leopardus pardalis) Predation on Agouti (Dasyprocta punctata)1
Authors: Aliaga‐Rossel Enzo , Moreno Ricardo S. , Kays Roland W. , Giacalone Jacalyn
Published: July 2006

We collected details on the predation of four agoutis (Dasyprocta punctata) by ocelots (Leopardus pardalis). All kills were made outside of the typical agouti activity period (<0500 h). Agoutis were captured from behind and killed with a bite through the back of the skull. The kill sites for two female agoutis were significantly closer to their den sites than expected, while kill sites for two males were not. All carcasses were completely covered by leaves during the day and were fed on during night hours. Predation by ocelots can be a significant cause of mortality for agoutis at Barro Colorado Island (BCI).
The universal rotation curve of spiral galaxies
Authors: Kirillov A. A. , Turaev D.
Published: July 2006

The observed strong dark-to-luminous matter coupling is described by a bias relation between visible and dark matter sources. We discuss the bias which emerges in the case where the topological structure of the Universe at very large distances does not properly match that of the Friedman space. With the use of such ‘topological’ bias, we construct the universal rotation curve (URC) for spirals which happens to be in striking agreement with the empirically known URC. We also show that the topological bias explains the origin of the Tully–Fisher relation (L∼V4) and predicts peculiar oscillations in the URC with a characteristic length .
Subsurface Disposal of Liquid Industrial Wastes in Alabama—A Current Status Reporta
Authors: Tucker William E.
Published: July 2006

Four subsurface disposal wells have been drilled and completed in Alabama. These are: Stauffer Chemical Company, Mobile County; Ciba‐Geigy, Inc., Washington County; U. S. Steel Corp., Jefferson County; and Reichhold Chemicals, Inc., Tuscaloosa County. The Geological Survey of Alabama has been directly involved in all four projects. The Survey served as a consultant to the Alabama Water Improvement Commission, the State agency responsible for protection of surface and ground water in Alabama, on the Stauffer and Ciba‐Geigy projects, and as consultant and supervisor on the U. S. Steel Corporation and Reichhold Chemicals, Inc., projects. These projects were undertaken as a research effort to insure that the responsible State agencies are fully cognizant of all aspects of this method of waste disposal. It is a policy in Alabama that subsurface disposal is permissible for some wastes if the well is properly designed and completed in an appropriate geologic environment and if conventional methods of waste treatment have been evaluated and proved to be inadequate.

The Stauffer well, operating at 75 gallons per minute and 500 psi, is the only subsurface disposal system, other than oilfield brine disposal wells, that is currently in operation. The Stauffer and Ciba‐Geigy wells are in the Coastal Plains geological province and the U. S. Steel and Reichhold Chemicals, Inc., wells are in Paleozoic sediments of the Warrior Basin. A general discussion of the geology, drilling, completion, and testing techniques is presented for the two geologic provinces involved.
Subsurface Storage and Disposal in Illinoisa
Authors: Smith H. F.
Published: July 2006

The storage of both liquids and gases in underground strata has become rather common in Illinois.

The problem of disposal of fluid industrial wastes has caused greatest concern, especially for the possible effects on ground‐water quality. Necessary precautions have been established in the requirements of the Illinois Environmental Protection Agency (IEPA) which has authority to control, prevent, and abate pollution of streams, lakes, ponds, and other surface and underground waters in the State. Before any construction can begin on storage in subsurface strata, a permit must be secured from the IEPA. Eight basic design policies have been adopted that have to be met before a construction permit will be issued.

Sandstone, limestone, and dolomite are the basic lithologies most commonly considered as potential disposal reservoirs in Illinois. From well cores of such formations, essential laboratory studies are conducted defining the rate of fluid movement, porosity, and permeability of the rock and the pressure distribution within the aquifer.

Plugging of the injection horizon is the most serious cause of damage to a fluid injection system and results from the forming of an impermeable deposit on the well bore or plugging in the formation itself. In either case the plugging may result from a number of listed causes.

To date there have been four industrial waste disposal wells in Illinois. Variation in conditions is illustrated by these cases of disposal wells that have been authorized by the State.

The first practical use of underground gas storage in Illinois was at Waterloo in 1950. Since then, the number of projects and their capacities have grown continuously. At the present time there are 24 underground gas storage projects. Gas injection pressures must be kept below the fracturing pressure of the caprock. In underground gas storage reservoirs in Illinois, injection pressures of approximately 0.55 psi per foot are often used.

Secondary recovery by water flooding accounted for 73.4 percent of the total oil production in Illinois during 1968. In that year there were 880 active projects in Illinois with 13,107 water injection wells that injected 2581 million gallons of water.
Feasibility of Recharging Treated Sewage Effluent into a Deep Sandstone Aquifera
Authors: Schicht Richard J.
Published: July 2006

Artificial recharge with tertiary treated sewage effluent has been suggested as one remedial measure for projected ground‐water deficits in the Chicago region. A deep sandstone aquifer, an important source of ground water in the region, offers the best opportunity for artificial recharge. Recharge will be through wells since the aquifer is deeply buried. Expected problems in maintaining well injection capacity were studied by recharging treated effluent through formation cores of the sandstone. Some success was had in maintaining recharge rates at constant heads for several days.
Pesticide Contamination of a Shallow Bored Well in the Southeastern Coastal Plainsa
Authors: Lewallen M. J.
Published: July 2006

A comprehensive examination was made of a shallow farm well which was contaminated with persistent pesticides when contaminated soil was used as backfill material around the well casing. The well location was less than 25 feet from a site previously used for flushing an insecticide sprayer.

Pesticide level in the water has been monitored for more than 4 years, during which a gradual decline in concentration has occurred. Soil core samples taken in the area surrounding the well indicate relatively high surface contamination but very little downward movement. Sediment samples from the bottom of the well exhibited highest concentration of all samples.
Methods of Geologic Evaluation of Pollution Potential at Mountain Homesitesa
Authors: Waltz James P.
Published: July 2006

Development of mountain homesites is accelerating in the Rocky Mountains of central Colorado. These homesites often require individual water wells and sewage disposal systems. Unfortunately, the widely used septic tankleach field system generally is not suited for use in the mountainous terrain where soils are thin or missing. Although current federal regulations call for six feet or more of soil at the leach field site, many of the individual sewage disposal systems now in operation in the Rocky Mountain Region of Colorado fail to meet this requirement. Sewage effluent at these sites may directly enter bedrock fractures and travel large distances without being purified. As a consequence, contamination of streams, lakes, and ground water from these malfunctioning leach fields has become a problem of increasing magnitude.

Investigations of geologic, topographic, and hydrologic conditions at over 100 homesites in the Rocky Mountains of north‐central Colorado have resulted in the development of objective criteria for evaluating pollution potential at mountain homesites. In addition, the results of these investigations indicate that contamination of water wells may be decreased significantly where geologic conditions are considered in the selection of sites for leach fields and wells. Although the results of these studies should be considered preliminary, they do tend to confirm that the orientation of jointing surfaces in the bedrock significantly affects the travel path of contaminants.
Salty Ground Water and Meteoric Flushing of Contaminated Aquifers in West Virginiaa
Authors: Wilmoth Benton M.
Published: July 2006

Salty ground water is commonly encountered at relatively shallow depths of 100 to 300 feet beneath the major stream channels in the western half of West Virginia. Because of the wide distribution of salty ground water and connate brine at various depths, it is difficult to distinguish natural contamination from that caused by subsurface industrial activities. Natural changes in quality apparently are minor. The available historical data indicate no large‐scale natural variations in salt content during the period of record. Histories of some water well developments show unnatural large‐scale increases in salt content from various industrial activities that affect the fresh water zones. Some records also reveal decreases in salt content after the source of the salt was eliminated or after the subsurface activity responsible for artificial migration of the salt water was stopped.

Artesian brine contaminated a fresh water aquifer in Fayette County. Chloride content changed from 53 mg/l to more than 1,900 mg/l in a period of 5½ years. When pumping was stopped, chloride content decreased to 55 mg/l in 10 years.

Heavy pumping of well fields in Charleston during 1930 to 1956 accelerated migration upward of salt water. Chloride content increased from less than 100 mg/l to more than 300 mg/l in some wells and to more than 1,000 mg/l at individual wells. Pumpage has declined greatly since 1956 and chloride content has decreased below 200 mg/l at some of the contaminated wells.

In an oil field of Kanawha County, a water well was contaminated by salt water accelerated by subsurface activities. Chloride content increased from less than 100 mg/l to more than 2,900 mg/l within 2 months. After the oil‐field activity was curtailed, chloride content decreased to 190 mg/l in about 2½ years. Road salt piles contaminated a carbonate aquifer in Monroe County. Chloride concentrations in wells located 1,500 feet from the piles increased from 185 mg/l to 1,000 mg/l in 5 years. The greatest change was 1,000 mg/l in 1969 to 7,200 mg/l in 1970 when the salt storage area was enlarged. All salt piles were removed in late 1970 and within 2 months chloride content decreased to 188 mg/l.
Hydrogeology Is More Than a Classical Sciencea
Authors: Stephenson D.
Published: July 2006

Contemporary use patterns of land and water resources create conflicts between natural and human environments. These conflicts are generally not discussed as part of a classical approach to geologic education. This paper addresses the need to increase non‐earth science training simultaneous with traditional training. The benefits to be gained will be welcomed by both students and their potential employers. One approach to suggested interdisciplinary water‐resource education is discussed.
Artificial Recharge — State of the Arta
Authors: Brown R. F. , Signor D. C.
Published: July 2006

The largest potential reservoir for the storage of potable water is in the unsaturated zone. Use of this space for the storage and retrieval of potable water is a multifaceted problem which requires application of the best talent from the scientific community.

Artificial recharge has many similarities to liquidwaste disposal through deep wells. In both, the problem is to place liquid in a permeable lithologic unit at an economic rate, to predict movement and the chemical reactions and physical changes that take place while the liquid is in the reservoir. Differences between the two operations are principally in the type of fluid injected and the ultimate objective. In artificial recharge the objective is to store and retrieve water of good quality; in waste disposal the objective is to store permanently water of objectionable quality. In both artificial recharge and liquid‐waste storage, the nature of the storage must be known, particularly that of the unsaturated zone. The techniques of investigation for recharge and waste disposal are generally the same.

Water commonly is recharged by surface spreading through basins or by induced recharge from adjacent streams and lakes or through injection wells. Research in recharge through basins has been dominated by mathematical models based on idealized conditions and empirical relations, derived by experimental sequencing of recharge operations, and operational controls in the pretreatment of recharge water. Recharge by injection wells has been undertaken in a variety of hydrologic environments. In Israel efforts have been directed toward the analyses of diffusion and dispersion of the injected water. Much research in the United States has been directed toward the movement of bacteria and organic matter through an aquifer and toward the chemical modeling of changes in recharged water as it moves.

Much more research is needed on the basic properties of aquifers, particularly in the unsaturated zone, and on all aspects of recharge‐water quality. Research and the use of data produced are increasingly the responsibility of interdisciplinary teams which consider the geologic, hydraulic, and economic aspects of the system.
New Priorities for Ground‐Water Quality Protectiona
Authors: Miller David W. , Scalf Marion R.
Published: July 2006

Four regional studies of the status of ground‐water pollution problems in 26 States have been sponsored by the U.S. Environmental Protection Agency. These investigations involved comprehensive reviews of the literature and contacts with public officials and others involved in water supply, so that individual case histories of ground‐water contamination problems could be evaluated. Septic tanks and cesspools, petroleum exploration and development, landfills, irrigation return flows, and surface discharges, impoundments, and spills are the principal sources leading to degradation of ground‐water quality.

Only a very small percentage of the instances of ground‐water contamination that probably exist has been discovered to date, and almost all the reported cases were only discovered after a water‐supply source had been noticeably affected by one or more pollutants. In the vast majority of cases inventoried, the problem has not been corrected and will become more troublesome in the future. A prime need in all four regions is a greater effort toward locating and evaluating as many additional cases of ground‐water contamination as possible.
Rational Basis for Septic Tank System Designa
Authors: Laak Rein , Healy Kent A. , Hardisty Dan M.
Published: July 2006

About 17 million families in the U. S. A. are served by septic tank and subsurface seepage systems. Rational design of these wastewater disposal systems includes three aspects. First the system must be hydraulically sound. This means that the flow regime and the storage and water carrying capacity of the receiving soil should be measured before design. A soil with a coefficient of permeability of less than 10‐4 ft/min (5 × 10‐5 cm/sec) suggests, for example, that the hydraulic capacity of the system governs the size of the subsurface leaching field. Seasonally high water tables or impervious strata may retard the flow and reduce the quantity of wastewater that can be carried away from the subsurface disposal area. In this case an elevated bed can be designed to increase the potential hydraulic gradient.

The second consideration concerns the biological mat in leaching fields. Leaching fields can be designed with higher loadings in soils having a greater coefficient of permeability than 10‐4 ft/min (5 × 10‐5 cm/sec) if increased pretreatment is used. A mathematical relationship was developed for reducing the size of leaching fields for effluents with a BOD5 plus suspended solids less than 250 mg/1. Leaching fields were projected to operate indefinitely. Long‐term loading rates for different soil permeabilities were plotted on a graph which can be used for sizing fields.

The third design consideration concerns preservation of the ground‐water quality. The travel of phosphate and nitrogen has been studied by others and by the authors. Concrete sand and silt with an unsaturated thickness of 1.5 feet (38.1 cm) still removed after 2 years of operation 30% of septic tank effluent phosphate and nitrogen. The effluent from the test soils had a concentration of about 13 mg/1 phosphate and 15 mg/1 nitrogen mostly in the NO‐3— N form.
Hydrocarbon Dispersion in Ground Water: Significance and Characteristicsa
Authors: Osgood John O.
Published: July 2006

Ground‐water contamination resulting from hydrocarbon spills is a significant problem which has received little attention. Over two hundred spills to the ground have been investigated during the last two and a half years by the Ground Water Section of the Pennsylvania Department of Environmental Resources. Explosions, injuries, damaged water supplies and other serious consequences have forced the recognition that these cases are important. Since Federal regulations are unsatisfactory in preventing spills to the ground, it is clearly the responsibility of the State to develop meaningful controls.

Hydrocarbon dispersion is essentially a shallow ground‐water problem. The hydrogeologic characteristics at the spill site are critical in determining dispersion once the hydrocarbon has reached the water table. The hydrocarbon is largely contained on top of the water table. In unconsolidated deposits or in fill material, the shallow ground‐water flow system and the direction of hydrocarbon dispersion will coincide. In sedimentary rocks the orientation of the rock becomes critical. When the dip is shallow enough to contain the water table, dispersion may either coincide with the major flow direction or may diverge from it where facies changes or significant changes in packing are encountered. Dispersion will parallel the strike of the rock in more steeply dipping rocks rather than the major ground‐water flow direction. Lateral movement will be controlled by jointing and fracturing. Solution channels and fractures exert the major controlling influence on heavily cemented soluble limestones. In tightly cemented clastics, crystalline rocks and less soluble carbonates, contaminant flows on top of the water table in fractures. Hydrocarbons may be imprisoned where solution channels and fractures do not intercept other openings within the water‐table plane.

Recovery programs for most hydrocarbon spills are complex. Larger cases receive the greatest attention; however, smaller ones are actually more significant since they are more common. Recovery costs are expensive and complete removal is extremely time‐consuming. Better maintenance and emergency response plans must be developed, even by small users. Federal and State governments must recognize the problem as being serious and must develop revolving product recovery funds to be used in ground‐water cases. Lastly, ground‐water spills must be handled by ground‐water specialists. Experimentation by those who lack the proper qualifications can prove very costly.
Pickling Liquors, Strip Mines, and Ground‐Water Pollutiona
Authors: Pettyjohn Wayne A.
Published: July 2006

In 1964 a waste disposal firm began dumping neutralized spent pickling liquors into an abandoned strip mine in eastern Ohio. In 1970 the disposal pit was enlarged and shortly thereafter significant water pollution problems began to occur. Highly mineralized fluids began to leak from the disposal pit into the surrounding spoil material and eventually into streams and ponds. These solutions are characterized by a low pH and excessive concentrations of dissolved solids, hardness, sulfate, chloride, nitrate, iron, fluoride, aluminum, chromium, nickel, and zinc.

In addition to the contamination by steel mill wastes, acid‐mine drainage from surrounding areas degrades both surface and ground water. Acid‐mine drainage is characterized by a low pH, and high concentrations of dissolved solids, hardness, sulfate, and iron.

Geohydrologic and geochemical data clearly illustrate that abandoned strip mines should not be used for the storage of toxic liquid or semiliquid materials.
Investigating Ground‐Water Pollution from Indianapolis'Landfills ‐ The Lessons Learneda
Authors: Weist William G. , Pettijohn Robert A.
Published: July 2006

In cooperation with the city of Indianapolis, the U.S. Geological Survey undertook a study to determine the nature and extent of water pollution resulting from the operation of seven landfills in or near the city. To accomplish this, 10 to 36 observation wells, ranging from 14 to 170 feet (4 to 52 metres) deep, were installed in and around each landfill. The wells were installed variously by auger, rotary, and air‐rotary methods; the mud for the rotary drilling was natural mud, bentonite and(or) an organic polymer. The wells were constructed of 2‐inch (5‐centimetre) PVC casing, and ended either in slotted casing or PVC “wire‐wrapped” screen. After the wells were completed and developed, water samples were collected from selected wells for detailed chemical analysis. This type of analysis will be repeated yearly on selected wells. Every month the water levels are measured and field determination of four chemical and physical water parameters are made. Water samples have been collected using a bailer, a centrifugal pump, and a gas‐driven pump.

Based on the experiences so far, the following are considerations in planning future studies:

Keep the objectives of the study well in mind in planning the methods to be used and the financing.

Black iron pipe is suitable well casing except when careful analyses are needed for research projects, for sampling concentrated leachate, or where rapid corrosion can be expected.

Use of 4‐inch (10‐centimetre) casing may provide more options than 2‐inch (5‐centimetre) casing as to method of collecting water samples, and may be easier to install and develop.

A power auger is preferable for drilling and installing small‐diameter wells in refuse.

A drilling mud made with an organic polymer is effective, particularly if 2‐inch (5‐centimetre) casing is used, but provides a medium for bacterial growth.

When the water level is too deep for a centrifugal pump to function in a 2‐inch (5‐centimetre) well, a bailer is more efficient and fairly contaminant‐free.

Once good control on water quality is obtained, field determination of selected parameters is sufficient to follow movement of a leachate plume.
ERTS Imagery for Ground‐Water Investigations
Authors: Moore Gerald K. , Deutsch Morris
Published: July 2006

ERTS imagery offers the first opportunity to apply moderately high‐resolution satellite data to the nationwide study of water resources. This imagery is both a tool and a form of basic data. Like other tools and basic data, it should be considered for use in ground‐water investigations. The main advantage of its use will be to reduce the need for field work. In addition, however, broad regional features may be seen easily on ERTS imagery, whereas they would be difficult or impossible to see on the ground or on low‐altitude aerial photographs.

Some present and potential uses of ERTS imagery are to locate new aquifers, to study aquifer recharge and discharge, to estimate ground‐water pumpage for irrigation, to predict the location and type of aquifer management problems, and to locate and monitor strip mines which commonly are sources for acid mine drainage. In many cases, boundaries which are gradational on the ground appear to be sharp on ERTS imagery. Initial results indicate that the accuracy of maps produced from ERTS imagery is completely adequate for some purposes.
Ground‐Water Pollution by Wood Waste Disposal
Authors: Sweet H. R. , Fetrow R. H.
Published: July 2006

Timber production and wood products industries in the Mid‐Willamette Valley of Oregon annually dispose of about 547,000 tons (500,000 tonnes) of wood and bark wastes. Land storage or disposal of these wastes can result in the generation of significant volumes of leachate.

Wood waste leachates are commonly characterized by lignin‐tannin (measured as tannic acid), oxygen demanding materials, color, and odor. In this study, lignin‐tannin concentrations in the ground water ranged as high as 7.5 mg/l; iron and manganese were also shown to increase markedly relative to natural background concentrations, ranging as high as 13 mg/l and 106 mg/l, respectively.

In August 1972 the area affected by the contaminated ground water covered about 4 acres (1.6 hectares) and extended nearly 1,000 feet (330 meters) downgradient from the disposal site. By late January 1973 the plume had migrated laterally to affect an area of about 15 acres (6 hectares) while extending over 1,500 feet (460 meters) downgradient. The lateral migration is attributed to a seasonal change in the local flow system. At least eleven existing domestic water‐supply wells have been rendered nonpotable by this pollution.
Conjunctive Availability of Surface and Ground Water in the Albuquerque Area, New Mexico: A Modelling Approach
Authors: Brutsaert Willem F. , Gebhard Thomas G.
Published: July 2006

This study is part of an interdisciplinary analysis of the economic evaluation of the water resources of the Rio Grande region of New Mexico. It was elemental in obtaining dynamic water availabilities in time and space.

The relationship of dynamic ground‐water availability and aquifer behavior under projected stresses was modeled by a ground‐water system simulator based on a mass balance of the hydrologic basin. Conditions from extreme dry to extreme wet were modeled, combined with a range of different water demands. A vast amount of information was thus obtained in the form of aquifer responses for different conditions. An analogous relationship was constructed from these data by stepwise multiple regression analysis and was of the following form

λd = f (dn, L)

where λd = change in water‐table elevation for the time period considered, dn= water‐table elevation at the end of the previous time period, and L = a lump factor combining surface‐water inflow and outflow, precipitation, and beneficial and nonbeneficial water uses.

Other results readily obtainable from the simulation runs are river accretion or depletion curves as a function of time. These curves show the diversion effects of groundwater pumping upon the river.
The Solubility of Ferric Oxyhydroxides in Natural Waters
Authors: Whittemore Donald O. , Langmuir Donald
Published: July 2006

Iron in ground water is often present both in solution and as suspended ferric oxyhydroxides. In most instances amounts of dissolved iron in natural waters are limited by the solubility of the ferric oxyhydroxides, whether suspended or present as part of aquifer materials. Oxyhydroxide solubilities, which range widely in natural waters, may be described by pQ =‐log [Fe3+] [OH‐]3, where [Fe3+] [OH‐]3 is the product of ion activities in the water. pQ. values calculated from Fe(II), Eh, and pH measurements in several types of high iron ground and surface waters (Fe(II) = 0.02 to 1460 ppm) indicate that most of the waters are in equilibrium with ferric oxyhydroxides which range from amorphous material to crystalline goethite (pQ values at 25°C from about 37 to 44, respectively). Stabilities generally increase (higher pQ's) in a given water with time. In general, the lower the dissolved iron, the more soluble is the oxyhydroxide precipitated and the slower its increase in stability. This was observed both in coastal‐plain ground waters (pQ= 36.6 ‐ 42.7), and in laboratory aged solutions. The faster the oxidation and hydrolysis rate of dissolved Fe(II), the lower the pQ, as shown by the reaction of mineralized spring waters with varying amounts of surface waters (pQ= 37.2 ‐ 41.5). Where saturation of water with siderite occurs, the siderite is in equilibrium with amorphous ferric oxyhydroxides (pQ= 36.9 ‐ 37.4 for calcium, magnesium bicarbonate ground waters). pQ values > 44.2, in a flooded coal mines for example, indicate that another iron mineral such as pyrite may control dissolved iron level.
THE OCCURRENCE AND DEVELOPMENT OF GUEST SINK, HERNANDO COUNTY, FLORIDA
Authors: Boatwright Barbara A. , Allman David W.
Published: July 2006

The spectacular occurrence of a sinkhole near the Gulf Coast of Florida engulfed a well drilling rig, a water truck, and a load of PVC pipe on a trailer, all within less than 10 minutes. The 150‐foot diameter sinkhole, which was initially dry and extended to a depth of 59 feet below mean sea level, developed suddenly on September 19, 1974. This occurred during the drilling of a 6‐inch well in Hernando County, about 5 miles inland from the Gulf of Mexico at a land surface elevation of 11 feet above mean sea level. The sinkhole which displaced 6500 cubic yards began to develop when the drill bit entered a cavity at a depth of 202 feet. Numerous satellite sinks ranging up to 20 feet in diameter occurred simultaneously with the develop‐ ment of the parent sink. Within 24 hours, ground‐water discharge into the parent sink from the shallow, unconfined and unconsolidated aquifer had filled the sink to an elevation of 8 feet above mean sea level. The total esti‐ mated replacement cost of the equipment lost in the sinkhole is $120,000.
Aquifer Evaluation Using Depositional Systems: An Example in North‐Central Texas
Authors: Hall W. Douglas , Turk L. Jan
Published: July 2006

Delineation of major depositional systems and their component facies within the Lower Cretaceous Hosston and Hensel Sandstones provides a model for predicting the distribution and chemical composition of water in the aquifer. Two major depositional trends occur in the Hosston Formation: (1) a dip‐oriented meanderbelt fluvial system which supplied sediment to (2) a strike‐oriented, high‐destructive, wave‐dominated delta system in the east. The Hensel deposits prograded eastward across the featureless upper surface of the Pearsall Formation, forming two depositional systems similar to those of the Hosston. The meanderbelt sandstone facies of the fluvial systems and the coastal barrier facies of the delta systems are capable of supplying greater amounts of ground water than the floodbasin, lagoon‐marsh‐embayment, or prodelta/shelf facies. Ground water is dominantly of the calcium‐magnesium bicarbonate type in the fluvial systems but changes downdip to sodium sulfate and sodium bicarbonate types in the delta systems. The change in chemical equilibrium probably occurs as dolomite‐rich waters from the fluvial facies percolate downdip and dissolve anhydrite or oxidize pyrite in lagoonal facies within the delta system, and calcium may be exchanged for sodium on the marine clays.
Applications of Electro‐Osmosis to Ground‐Water Flow Problems
Authors: Lewis Roland W. , Humpheson Chris , Bruch John C.
Published: July 2006

The solution of two‐dimensional ground‐water flow in soils of low hydraulic conductivity under the influence of both electrokinetic and hydrodynamic forces is found using the finite element method. The example investigated deals with a confined aquifer in which there is a recharging as well as a discharging well present. The results demonstrate the effect of the application of the electro‐osmosis phenomenon. The formulation is general and permits the analysis of not only arbitrary shaped boundaries but also different electrode configurations.