bluuebunny/crossref_metadata_2025 huggingface dataset:
Adrenocorticotropic Hormone Immunoreactivity in the Hippocampal Formation of Temporal Lobe Epilepsy Patients
Authors: Lynd‐Balta Eileen , Pilcher Webster H. , Joseph Shirley A.
Published: August 2005

Summary: Purpose: We wished to identify immunocytochemically the distribution of proopiomelanocortin‐related peptides in the hippocampal formation of patients with epilepsy.

Methods: Surgical hippocampal specimens from temporal lobe epilepsy (TLE) patients and autopsy control tissue were examined immunocytochemically for ACTH, α‐melanocyte‐stimulating hormone (α‐MSH) and α‐endorphin.

Results: There was a dense distribution of ACTH‐immunoreactive neurons in the hippocampal formation of patients with mesial TLE syndrome (MTLE). These hippocampal specimens showed significant cell loss. ACTH‐positive neurons were most prominent in the subiculum, with scattered ACTH‐immunoreactive neuronal elements distributed in the cornu ammonis fields and hilus. Light ACTH immunoreactivity was detected in the tumor‐related epileptic hippocampal specimens, which showed minimal cell loss. Although autopsy control tissue from the hypothalamus showed intense ACTH staining patterns in cells and fibers, there was little or no ACTH immunoreactivity in the autopsy hippocampal tissue. The expression of ACTH immunoreactive elements was correlated with patterns of cell loss. No α‐MSH‐ or β‐endorphin‐immunoreactive neurons were detected in any of the hippocampal specimens.

Conclusions: ACTH has anticonvulsant properties, and its novel expression in the glutamatergic subicular neurons, which provide the main outflow of the hippocampal formation, may represent an attempt by the damaged hippocampal circuit to restore the balance of excitatory/inhibitory neurotransmission in TLE.
Reduced Plasma Nisoldipine Concentrations in Phenytoin‐Treated Patients with Epilepsy
Authors: Michelucci R. , Cipolla G. , Passarelli D. , Gatti G. , Ochan M. , Heinig R. , Tassinari C. A. , Perucca E.
Published: August 2005

Summary: Purpose: To assess whether phenytoin affects the pharmacokinetics of the dihydropyridine calcium antagonist nisoldipine.

Methods: Twelve patients with epilepsy receiving chronic phenytoin therapy and 12 healthy control subjects matched for age and gender received a single oral dose of nisoldipine (40 and 20 mg, respectively). Blood samples were collected for up to 48 h for estimation of plasma nisoldipine levels by capillary gas chromatography.

Results: Mean plasma nisoldipine concentrations were much lower in the patients. Geometric means for areas under the concentration‐time curve (AUC0‐tn) normalized to a 20‐mg dose were 1.6 μg/L/h (95% confidence intervals, 0.6–3.8 μg/L/h) in the patients compared with 15.2 (10.7–21.6) μg/L/h in control subjects (p < 0.002).

Conclusions: These results suggest that phenytoin increases the first‐pass metabolism of nisoldipine to a clinically important extent. In view of the magnitude and variability of interaction, use of nisoldipine in patients receiving chronic phenytoin therapy is contraindicated. Key Words: Epilepsy‐ Nisoldipine‐Phenytoin‐Pharmacokinetics‐Drug interaction.
Nonconvulsive Status Epilepticus After Intravenous Contrast Medium Administration
Authors: Lukovits Timothy G. , Fadul Camilo E. , Pipas J. Marc , Williamson Peter D.
Published: August 2005

Summary: Purpose: We describe a 52‐year‐old man with a glioblastoma multiforme who had a prolonged partial seizure immediately after undergoing a computed tomography (CT) scan of the head with intravenous contrast medium.

Methods: Earlier computed tomography (CT) had demonstrated a ring‐enhancing hypodense mass. The patient was treated with a regimen of intravenous Tirapazamine and brain irradiation. After CT scan performed on the day of his second hospitalization, the patient became aphasic. EEG showed continuous high‐voltage semirhythmic sharp and slow waves in the left posterior temporal and parietal regions consistent with status epilepticus (SE). Intravenous lorazepam and a loading dose of phenytoin were administered.

Results: On the next morning, the patient's condition had improved almost to baseline. He had no recurrent seizures. EEG at 2‐month follow‐up showed no epileptiform discharges.

Conclusion: This appears to be the first reported case of contrast medium‐induced status epilepticus.
Intractable Epilepsy in Children
Authors: Holmes Gregory L.
Published: August 2005

Summary: Although most children with epilepsy have a good prognosis, a small but significant minority have seizures that either do not respond to conventional antiepileptic drugs (AEDs) or have significant adverse reactions to AEDs. Many children may benefit from epilepsy surgery. Surgical treatment of epilepsy is becoming a well‐established therapy for infants and young children with severe, medically intractable seizures. As in older children and adults, the presurgical evaluations of possible surgical candidates typically consist of a detailed history, neurologic and neuropsychologic examination, and anatomic and functional neuroimaging. The “gold standard” test, however, is the recording of ictal events by using simultaneous EEG and videomonitoring. Although temporal lobe resection is the most commonly performed surgery in older children and adults, nontemporal lobe resection, corpus callosotomy, and hemispherectomy are commonly performed in younger children. Efficacy of surgery in children compares favorably with results from adult patients. In addition, because the immature brain is more plastic than the mature brain, recovery of function is often greater after surgery in children than in adults. Early surgery in children with intractable epilepsy is recommended.
Quality of Life in Adult Patients with Epilepsy
Authors: Kugoh Toshiaki
Published: August 2005

Summary: Quality of life (QOL) must be determined from the patients’ subjective viewpoint. To determine QOL in epilepsy, it is necessary to use disease‐specific scales. We introduced the Side Effects and Life Satisfaction (SEALS) scale to Japan and performed a comparative study on adult patients with epilepsy and normal subjects. The results for patients with epilepsy were determined by the number of prescribed antiepileptic drugs (AEDs), the total dosage, and the type of epilepsy. Problems in patients with epilepsy were expressed by vertically crossing lines. A horizontal line expressed the severity of disease, and a vertical line expressed the psychosocial functioning. Therefore we cannot separate the severity and QOL when considering the influence of epilepsy disorders on individual patients. These two components compose the biphasic dimensions of QOL and thus are analyzed coincidentally. The concepts of QOL and comprehensive management in epilepsy are closely related, but the fundamental viewpoints are located at opposite positions. The former is based on the physicians’ viewpoints and the latter on the patients’ viewpoints. Although ideally these two concepts should be in harmony, they are in reality frequently dissociated. In comprehensive management, the treating physician must vigorously consider the influence of therapy on the patients’ QOL.
An Anthropological View of Quality of Life: Therapeutic Objectives and Social Contradictions
Authors: Yeh E. Ann
Published: August 2005

Summary: The improvement of quality of life (QOL) is now widely accepted as an important goal of health care. Underlying the acceptance of QOL is the unspoken assumption that therapies and practices associated with QOL are inherently beneficial. The uses of QOL in the treatment of epilepsy need scrutiny. Close attention must be given to the effects of policies instituted in the name of QOL, as significant social consequences may result from these policies.
Antiepileptic Drug Use in Nursing Home Residents: Effect of Age, Gender, and Comedication on Patterns of Use
Authors: Lackner Thomas E. , Cloyd James C. , Thomas Lucy W. , Leppik Ilo E.
Published: August 2005

Summary: Purpose: Examine antiepileptic drug (AED) use in nursing homes by age, gender, and use of comedication that can interact with AEDs.

Methods: Two point‐prevalence evaluations of AED use from computerized medical records of nursing home residents throughout the United States (set 1, 43,757; set 2, 41,386) 65 years and older serviced by PHARMERICA.

Results: 10.5% of residents received an AED. Of the age group 65–84 years, 15% received an AED compared with 6.1% of those 85 years or older (p < 0.001). Gender differences were present; 13.4% of the male residents and 9.4% of the female residents were treated with an AED (p < 0.001). The most frequently prescribed AEDs were phenytoin, carbamazepine, clonazepam, or phenobarbital. The average number of routine medications taken by AED recipients was 5.6, greater than the average of 4.6 for other residents.

Conclusions: AEDs are extensively prescribed for elderly nursing home residents. Men and persons aged 65–85 years were more likely to receive AEDs than were women or those older than 85 years. AED recipients receive more routine medications than do other residents, including co‐medications that alter hepatic metabolism and clinical response. The reasons for age and gender differences are unclear and require further study.
A Stereoelectroencephalographic (SEEG) Study of Light‐Induced Mesiotemporal Epileptic Seizures
Authors: Isnard Jean , Guénot Marc , Fischer Catherine , Mertens Patrick , Sindou Marc , Mauguière François
Published: August 2005

Summary: Purpose: This study explored the mechanism of light‐induced complex partial seizures by using ictal intracerebral recordings in a patient with refractory epilepsy of the right temporal lobe.

Methods: Presurgical evaluation of this patient was realized by means of video‐EEG recordings, WADA test, magnetic resonance imaging (MRI), F18‐deoxyglucose and C11‐flumazenil positron emission tomography (PET) interictal neuroimaging data, and stereoelectroencephalographic (SEEG) ictal recordings.

Results: SEEG investigations demonstrated the right mesiotemporal origin of all the patient's seizures. This result was confirmed by a successful right temporal lobectomy. Moreover, SEEG recordings revealed a frequent interictal spiking activity in the right occipital visual cortex that was undetectable on scalp recordings. However, the occipital cortex was not involved at the onset of mesiotemporal ictal discharges and was not hyperresponsive to focal electrical stimulation.

Conclusions: This study shows that, in spite of interictal occipital spiking, the photosensitivity of mesiotemporal seizures can be observed in both the absence of occipital cortex involvement during ictal discharges and demonstrable hyper‐excitability of the occipital cortex to light or direct electrical stimulation.
Carbamazepine Intoxication with Negative Myoclonus After the Addition of Clobazam
Authors: Genton Pierre , Nguyen Vi Huong , Mesdjian Edouard
Published: August 2005

Summary: We report a case a carbamazepine (CBZ) intoxication with negative myoclonus that occurred 4 weeks after dobazam (CLB) had been added to a stable regimen of CBZ and topiramate (TPM). Both CBZ and CBZ‐epoxide (CBZ‐E) blood levels were elevated, and the symptoms resolved quickly when CBZ dosage was reduced and CLB discontinued. CLB was reintroduced a year later with the patient's consent, and the time course of the interaction was studied: CBZ and CBZ‐E levels increased slowly over 12 days. The interaction is thus probably related to the progressive increase in Nor‐CLB.
Uncoupling of Blood Flow and Metabolism in Focal Epilepsy
Authors: Bruehl Claus , Hagemann Georg , Witte Otto W.
Published: August 2005

Summary: Purpose: Interictal measurements of cerebral blood flow are less helpful in localizing epileptic foci than are measurements of brain metabolism. This may be related to an uncoupling of blood flow and metabolism. In this study, brain metabolism and blood flow were compared in an acute experimental model of focal interictal epilepsy.

Methods: Interictal epileptic foci were induced by an epicor‐tical application of penicillin in rats. After 1 h, stereotyped interictal activity was initiated, lasting until the end of the experiment. Brain metabolism was determined with [14C]deoxyglucose, and cerebral blood flow with [14C]iodoan‐tipyrine autoradiography.

Results: In control experiments, metabolism and blood flow were coupled. In animals with focal interictal epileptic activity, the metabolism was strongly increased in the focus and reduced in areas lateral to the focus. In contralateral brain areas, blood flow and metabolism varied in a parallel fashion. Ipsilateral to the focus, however, blood flow and metabolism were altered disproportionately. In the focus, the increase of blood flow was less marked than the increase of metabolism, and the area with increased blood flow was larger than the area with increased metabolism. Lateral to the focus, in the area with a hypome‐tabolism, blood flow was not concomitantly reduced.

Conclusions: The experiments show that blood flow and rnetabolism in focal epilepsy may be uncoupled in widespread regions. This is due neither to structural abnormalities nor to the duration or discharge pattern of epileptic activity. The results explain why interictal metabolic investigations have a higher predictive value in presurgical epilepsy evaluation than do interictal measurements of blood flow.
Activation of the Locus Coeruleus After Amygdaloid Kindling
Authors: Silveira D. C. , Liu Z. , de LaCalle S. , Lu J. , Klein P. , Holmes G. L. , Herzog A. G.
Published: August 2005

Summary: Purpose: Substnatia nigra (SN) and locus coeruleus (LC) neurons are implicated in the propagation and suppression of amygdaloid seizures. Both structures are activated concomitant with amygdaloid seizure discharges. Their rnechanisms of activation, however, remain to be elucidated. SN firing is not associated with the induction of Fos imrnunoreactiv‐ity (ir), a marker of excitatory neuronal activation. LC has not been studied. The purpose of this investigation was to determine if amygdala‐kindled generalized seizures could induce Fos‐ir in the LC.

Methods: Female Sprague‐Dawley rats were killed after generalized seizures induced by amygdala electrical stimulation and stained by using Fos irnmunocytochemistry. The number of Fos‐ir neurons was compared between 15 animals with generalized seizures and four implanted, unstimulated controls.

Results: LC‐ir neurons were significantly (p < 0.05) more prevalent after seizures than in control animals. Their numbers correlated very highly with Fos‐ir in the central nucleus of the amygdala (p < 0.0001). No Fos induction was observed in LC in controls or in the SN in either group.

Conclusions: Amygdala‐induced generalized seizures result in Fos‐ir in the LC but not in the SN. This is consistent with different mechanisms of activation possibly involving disinhi‐bition in the SN and direct excitation in the LC.
Neurocysticercosis in Persons with Epilepsy in Medellín, Colombia
Authors: Palacio L. Guillermo , Jiménez Ivan , Garcia H. Hugo , Jiménez Marta E. , Sánchez Jorge L. , Noh John , Ahn IlLisa , Mora Ofelia , Giraldo Margarita , Tsang Victor C. W. ,   The Neuroepidemiological Research Group of Antioquia
Published: August 2005

Summary:Purpose: A prospective series of 643 persons with epilepsy attending a reference neurologic center in Medellin, Colombia, was examined by computed tomography (CT scan) or serology or both with the enzyme‐linked immunoelectrotransfer blot assay (EITB) to assess the prevalence of Taenia solium cysticercosis.

Methods:All presenting patients were consecutively enrolled in the study. Five hundred forty‐six persons underwent cerebral CT scans; 376 of them also had serum EITB performed.

Results:Prevalence of neurocys@ercosis by CT scan was 13.92%. Overall prevalence ofT.solium antibodies with EITB was 9.82%, but for those with late‐onset epilepsy (onset after age 30 years), prevalence increased to 17.5% and 19% for those who originated from outside urban Medellin. Seroprevalence in individuals with mixed lesions (cysts and calcifications) was 88.2% and 64.10% in those with live cysts. Conversely, only 2.72% of persons with CT findings not related to neurocysticercosis had positive EITB tests.

Conclusions:Our study shows that an important proportion of individuals with epilepsy have radiologic or serologic evidence ofT.solium infection, suggesting that neurocysticercosis is an important etiology for epilepsy in Colombia.
Excision of Cortical Dysplasia in the Language Area with Use of a Surgical Navigator: A Case Report
Authors: Ozlen Fatma , Nakajima Shin , Chabrerie Alexandra , Leventon Michael E. , Grimson Eric , Kikinis Ron , Jolesz Ferenc , Black Peter McL.
Published: August 2005

Summary: Purpose: We have developed an intraoperative optical tracking‐based navigational system that allows localization in the operative space. Using three‐dimensional reconstruction, this system has provided precise spatial information for intraoperative cortical mapping in patients with intractable epilepsy in whom the lesion lies close to eloquent cortex.

Methods: A 23‐year‐old man with intractable complex partial seizures (CPS) presented to our institution. Proton‐density magnetic resonance imaging (MRI) showed a 3‐cm lesion which lay 2 cm beneath the left frontal operculum. A three dimensional model of the patient was reconstructed using MR modalities. Intraoperatively, subdural grid and strips were placed over the lesion and their electrodes were registered to the three‐dimensional model, which was displayed on a monitor. The navigational system was used to localize each electrode on the three‐dimensional model. By the second operation, the sites of seizure activity were established and recorded on the three‐dimensional model. A bipolar stimulator was also used to determine the speech area.

Results: The lesion, which proved to be cortical dysplasia, was removed completely and the cortical speech area was avoided. During the postoperative period, the patient had no neurological symptoms and no seizure activity.

Conclusions: The localization of a lesion and its correlation with epileptogenic foci is important in optimizing treatment in patients with cortical dysplasia. Our navigational system provided accurate localization of the lesion and correlation with the epileptogenic focus and related eloquent cortex. We believe that the safe removal of the lesion was facilitated by this system.
Challenges of an Outcome‐Based Perspective for Marriage and Family Therapy Education
Authors: Nelson Thorana S. , Smock Sara A.
Published: August 2005

Marriage and family therapy (MFT) and marriage and family therapy education (MFTE) have undergone many changes during the short history of MFT. This article describes the current trends and controversies in MFTE, including shifts toward outcome‐based education (OBE). We present recommendations for MFTE, including the move toward OBE, the development of core competencies of MFT, attention to interdisciplinary issues, and recognition of the need for both foundational education and encouragement of trainees' unique styles and approaches.
Patterns of Ground‐Water Chemistry, Ross Creek Basin, Alberta, Canada
Authors: Ophori D. U. , Tóth J.
Published: August 2005

On the basis of the degree of mineralization, approximately 40 percent of the ground water in Ross Creek Basin may be considered as fresh (TDS < 2,000 ppm), and 60 percent as brackish (2,000 < TDS < 10,000 ppm). At least 70 percent of the ground water is potable within treatable limits. Major ion analyses of over 167 water samples reveal a strikingly consistent regional pattern of hydrochemistry.

The hydrochemical pattern correlates with the flow pattern of ground water in the basin. Low total dissolved solids contents, high Ca2+:Mg2+ ratio, low SO42−, and high HCO3− occur in recharge areas, whereas opposite conditions are associated with discharge areas. In terms of hydrochemical facies, waters of the Ca‐Mg‐HCO3 and Na‐HCO3 types are dominant in recharge areas, and those of the Ca‐Mg‐SO4‐HCO3 and Na‐SO4‐HCO3 types prevail in discharge areas. The hydrochemical evolutionary trends appear to be strongly related to the flow paths.
Multivariate Analysis in Hydrochemistry: An Example of the Use of Factor and Correspondence Analyses
Authors: Usunoff Eduardo J. , Guzmán‐Guzmán Amado
Published: August 2005

Statistical‐based, semiquantitative techniques [Factor Analysis (FA) and Correspondence Analysis (CA)] were applied to chemical data from two aquifers to assess the usefulness of such techniques at the initial stages of hydrochemical studies.

For the first case, both FA and CA defined three factors to account for the major ion variations observed in the Milk River aquifer (Alberta, Canada), namely, sulfate reduction occurring in the recharge area and mixing of waters of different ages in the deeper portions of the aquifer, ion‐filtration processes, and ion exchange on clays. For the FA, the comparison between varimax and oblique rotations led to similar interpretations.

For the second study area, the San Pedro River basin (Arizona, U.S.A.), FA (Q‐mode) extracted two factors, which helped segregate waters from the two aquifers in the area. The CA, applied only to samples from the confined aquifer, drew two factors which were related to dissolution of gypsum coupled with ion exchange (softening) as the main mechanisms operating in the aquifer, along with a hypothetical presence of fluorite in the aquifer sediments to justify the rather high [F‐] observed in local ground waters.

Comparisons made between the results presented and the findings of earlier studies highlight the descriptive capabilities of FA and CA as exploratory tools in hydrochemical investigations.
Solute Transport Through Small and Large Unsaturated Soil Columnsa
Authors: Wierenga P. J. , Van Genuchten M. Th.
Published: August 2005

Unsaturated solute transport experiments were conducted using several small and one large column packed with the same sandy soil material.

Chloride and tritium were used as tracers for water movement. Soil solution samples were collected as a function of time in the small columns and versus time and depth in the large column. The data were compared with solutions of the classical two‐parameter convection‐dispersion equation and also with solutions of a more elaborate four‐ parameter transport model that assumes a fraction of the water to be immobile. Fairly symmetrical effluent curves resulted from both the small and large columns, suggesting small transfer coefficients between mobile and immobile regions and small amounts of immobile water. Dispersivity values ranged from 1 cm for the small columns to about 5 cm for the 6‐m‐long column; retardation factors for chloride were nearly the same (about 0.8) for both column sizes. Thus, while the dispersivity measured in the small columns did not apply to the large columns, the same retardation factors could be applied to the different scale columns.
Dissolved Inorganic Carbon in the Tucson Basin Aquifer
Authors: Rose Seth , Long Austin
Published: August 2005

The concentration of dissolved inorganic carbon (DIC) species and the other major ionic constituents were determined at 45 sampling locations within the Tucson basin aquifer. The distribution and concentration of the various inorganic carbon species were related to the hydrogeological characteristics of the principal recharge zones within this alluvial basin. Bicarbonate alkalinity concentrations were highest subjacent to a floodplain where calcite and other relict salts likely precipitated in the shallow subsurface under past pluvial conditions.

Calculated partial pressure of carbon dioxide (PCO2) values were highest where the water table is sufficiently elevated to support phreatophyte growth. The regional distribution of PCO2 suggests that the generation of carbon dioxide is limited to the oxidation of influent plant detritus below the stream channels. The alkalinization of Tucson basin ground water is ultimately constrained by this limited production of CO2. The dissolution of calcite in young ground water (<200 years) and the precipitation of calcite in deeper, more chemically evolved ground water likely represent other important controls upon DIC concentrations.
A METHOD FOR INSTALLING AND MONITORING PIEZOMETERS IN BEDS OF SURFACE WATERS
Authors: Welch Stephen J. , Lee David R.
Published: August 2005

A method has been tested for manually driving piezometers into the bottom sediments of surface waters. It allows piezometers to be driven from a surface working platform and after installation leaves a flexible piezometer line that does not pose a safety hazard on the water surface. The piezometer line may be attached to a float on the water surface or be extended to the shoreline enabling measurement of hydraulic head and geochemical sampling. These piezometers have been successfully installed in 6 to 8 meters (m) of water, 40 m offshore and 2 to 2·5 m below the sediment surface in medium‐ to fine‐grained sand.
The Kinetics of Fe(II) Oxidation and Well Screen Encrustation
Authors: Applin Kenneth R. , Zhao Naiyu
Published: August 2005

The unconsolidatcd sediments which border the Missouri River constitute an important ground‐water aquifer that has been developed for municipal and industrial water supplies. The hydraulic efficiency of wells in these sediments decreases with time because of well screen encrustation caused by the oxidation of dissolved ferrous iron to insoluble ferric oxyhydroxides. The kinetics of ferrous iron oxidation are strongly dependent upon the solution pH and to a lesser extent the dissolved oxygen content. Chemical analyses of the well water including pH, Eh, dissolved oxygen, and dissolved iron indicate that at least one‐half time for ferrous iron oxidation occurs prior to ground water entering the wells. As ground‐water velocity increases near a pumping well, shallow, oxygen‐bearing ground water may mix with deeper, reduced water by mechanical dispersion and turbulent flow and facilitate the oxidation of dissolved ferrous iron. Although little can be done to prevent well screen encrustation, the rate of encrustation may be slowed by regulated pumping and avoidance of shutdowns.
Calculation of Constant‐Rate Drawdowns from Stepped‐Rate Pumping Tests
Authors: van der Kamp G.
Published: August 2005

Drawdown and recovery data obtained for stepped‐ rate pumping tests can be used to calculate the drawdowns that would occur if the test were carried out a constant rate without stopping. The recovery phase of constant‐rate pumping tests can be analyzed by the same method because cessation of pumping can be treated as a step change of pumping rate. The calculation assumes only that pumping during each step is at a constant rate, and that the principle of superposition is applicable, i.e., that the ground‐water system is linear and time‐invariant. It does not depend on the availability of theoretical expressions for the drawdown due to pumping. The calculation can be carried out for as long as water‐level measurements are continued; however, possible errors in the values of calculated drawdown increase with increasing time, thus limiting the practical length of time for which the calculated values are reliable.

The constant‐rate drawdown curves characterize the response of the linear time‐invariant ground‐water system to pumping. They can be used for the determination of formation parameters if an appropriate theoretical model is available. They can also be used directly to predict drawdowns, and the scope of this application can be broadened by use of the reciprocity principle. In either case the use of recovery data can significantly extend the effective duration of pumping tests.
Septic Tank Setback Distances: A Way to Minimize Virus Contamination of Drinking Watera
Authors: Yates Marylynn V. , Yates S. R.
Published: August 2005

Septic tanks are the most frequently reported causes of contamination in ground‐water disease outbreaks associated with the consumption of untreated ground water in the United States. The placement of septic tanks is generally controlled by county‐wide or state‐wide regulations, with little consideration given to the local hydrogeologic, climatic, and land‐use conditions. Using the travel time necessary to achieve a seven‐order‐of‐magnitude reduction in virus number as the criterion, a wide range of septic tank setback distances (from less than 15 m to greater than 300 m) were calculated for a part of the Tucson Basin. This study makes use of disjunctive kriging to calculate the conditional probabilities associated with the setback distance estimates. The results are presented in two different ways: first, given a setback distance (e.g., prescribed by law) the probabilities that the level of viruses will be within acceptable limits are calculated; and second, the desired probability level is specified (e.g., 90%) and the setback distances required to achieve that level of confidence that the water will be free of virus contamination are calculated. The methods have potential for use by local government officials for land‐use planning purposes.
Detergent Formula Effect on Transport of Nutrients to Ground Water from Septic Systems
Authors: Alhajjar Bashar J. , Harkin John M. , Chesters Gordon
Published: August 2005

Two groups of new septic systems in coarse‐textured soils overlying shallow ground water were monitored for two years to determine the potential of contamination of individual ground‐water supply from the use of phosphate‐ built (PO4) or carbonate‐built (CO3) detergents. The distribution of nutrients and chloride in the shallow aquifer were examined to trace contamination from the septic systems.

The data were evaluated statistically, and a stochastic nutrient transport model was compiled to simulate ground‐ water contamination by nutrients for a five‐county region. The stochastic modeling of the data showed that neither detergent caused delivery of total phosphorus to ground water in concentrations above 0.1 mg/1 as P. However, total nitrogen was removed more efficiently from systems receiving PC4‐built than CO3‐built detergents. The total nitrogen from septic systems reached the ground water in concentrations of 39 and 69 mg/1 as N from PO4‐ and CO3‐built detergent use, respectively, The detergent formula has a substantial effect on ground‐water contamination by nitrogen from septic systems.
The Bouwer and Rice Slug Test — An Updatea
Authors: Bouwer Herman
Published: August 2005

The Bouwer and Rice slug test was developed to measure aquifer hydraulic conductivity around boreholes (production, monitoring, or test wells). The wells can be partially penetrating and partially screened, perforated, or otherwise open. The slug test can be based on quickly with‐ drawing a volume of water from the well and measuring the subsequent rate of rise of the water level in the well, or by adding a slug of water and measuring the subsequent rate of fall of the water level in the well. While originally developed for unconfined aquifers, the method can also be used for confined or stratified aquifers if the top of the screen or perforated section is some distance below the upper confining layer. Anomalies (“double straight line effect”) sometimes observed in the measured rate of rise of the water level in the well are attributed to drainage of a gravel pack or developed zone around the well following lowering of the water level. The effect of this drainage can be eliminated by ignoring the early data points and using the second straight line portion in the data plot for calculation of hydraulic conductivity. The method is applicable to any diameter and depth of the borehole, provided that the dimensions of the system are covered by the ranges for which the geometry factor Re has been worked out. The smaller the diameter of the hole, however, the more vulnerable the results will be to aquifer heterogeneities and to inaccuracies in estimating effective well diameters. Computer programs for rapid processing of the field data have been developed.
The Coastal Ground‐Water Boundary
Authors: Urish Daniel W. , Ozbilgin Melih M.
Published: August 2005

In many island and coastal ground‐water problems, the position of the ground‐water/free sea‐water interface is an essential, but highly dynamic boundary. The fluctuating boundary commonly is simplified to a fixed position in problem formulation. This fixed position is frequently taken as the location of local mean free‐water level (mean sea level) in the adjacent salt‐water body. However, tidal fluctuation and wave runup on a sloping beach cause mounding of sea water in the upper beach with a consequent effective mean sea level as much as two feet higher than local mean sea level. This phenomenon is particularly important in small islands and coastal situations where the ground‐water flow pattern is highly dependent on the position of the effective boundary both vertically and horizontally. In coastal hydrological situations, a good approximation for the effective vertical position, i.e. effective mean sea level, of the ground‐water/free sea‐water boundary is the mean equivalent salt‐water head in a deep discretely screened piezometer located in the beach near the upper swash line. The veracity of this technique is demonstrated by the results of field research in a New England barrier beach.
The Hydrologic Responses to Development in Regional Sedimentary Aquifers
Authors: Johnston Richard H.
Published: August 2005

The hydrologic response to development of three of the most heavily pumped sedimentary aquifer systems in the United States is similar in some aspects and different in others. In the semiarid West, an unconfined sand aquifer and a confined sand and clay aquifer system have been subjected to withdrawals that are far greater than predevelopment recharge rates. As a result, the aquifers have large losses of ground water from storage. In the humid East, pumpage from a carbonate aquifer system has resulted in induced recharge and diversion of natural discharge with insignificant loss from storage. However, the following responses to development are common in all three aquifer systems: (1) ground‐water circulation has increased,

(2) rates of recharge have increased—mostly due to recirculation of pumped ground water, or infiltration of imported surface water used for irrigation in the semiarid West,

(3) locations of recharge areas have changed, and (4) natural discharge has decreased.

Regional water‐level declines associated with ground‐ water development are inevitably accompanied by some combination of elastic compaction of aquifer material, inelastic compaction of fine‐grained sediments and land subsidence, dewatering of aquifer material near pumping centers, and induced formation of sinkholes. The degree to which these changes occur is dependent on: (1) rates of pumping in relation to available recharge, and (2) lithology, specifically the proportion of sand, gravel, silt, clay, and carbonate rock that comprise the aquifer system.
Estimating Water‐Table Altitudes for Regional Ground‐Water Flow Modeling, U.S. Gulf Coast
Authors: Williams Thomas A. , Williamson Alex K.
Published: August 2005

Water‐table altitude, a controlling factor for ground‐ water flow, was estimated from detailed topographic data by subtracting the estimated depth‐to‐water. Land‐surface altitude of the Coastal Plain in the south‐central United States varies from 0 to more than 800 feet above sea level. Predevelopment depth‐to‐water in 6,825 wells less than 150 feet deep averages 25.7 feet (standard deviation, 19.5 feet). Most water‐table‐altitude variation is due to variation in land‐surface altitude and not due to variation in depth‐to‐ water. Digital topographic data, from 1:250,000 scale maps for every 30 seconds of latitude and longitude are available for the continental United States. About 90 altitudes were averaged for each 25‐square‐mile block of a rectangular grid used for ground‐water flow modeling. Multiple linear regressions of predevelopment water‐level data and topographic data were used to derive empirical equations relating water‐table altitude to topography.

The regression method was more consistent, efficient, and accurate than manually digitizing values from manually contoured water‐table maps. Water‐table maps usually are prepared from few data that are concentrated in topographically flat areas. Manually digitizing water‐table maps on a regional scale introduces additional error. About 35 percent of the water‐table altitudes obtained manually were greater than average land‐surface altitudes from topographic data. The mean difference between water‐table altitudes from the two methods was less than 10 feet, which indicates no systematic error was incorporated in the regression method.
The Disposal of Nuclear Waste: A Problem in Mass Management?
Authors: Domenico P. A. , Lerman A. , Bartlett J. W.
Published: August 2005

A reference repository is examined for environmental compliance utilizing minimum performance standards as established by the Nuclear Regulatory Commission and the Environmental Protection Agency. These standards stipulate the amount of time the radionuclides must be retained in the barrier, the acceptable release rates from the barrier, and the acceptable mass release that can be registered at the accessible environment over a 10,000‐year time frame. The only natural, or geologic barrier standard specified is a minimum ground‐water travel time of 1000 years from the engineered barrier to the accessible environment. Other natural barrier processes including geochemical retardation and mass transfer, dilution, and dispersion are not specified. In attempting to determine the role that these unspecified components must play in order to comply with the mass release standard, we find that their role is minimal to the extent that virtually any rock type that can satisfy the minimum ground‐water travel time of 1000 years will satisfy the mass release requirements at the accessible environment. Full compliance with a concentration standard at the accessible environment requires that the nuclides contained within the larger inventories be fully contained with the controlled zone between the engineered barrier and the accessible environment
Identifying Fracture Interconnections Between Boreholes Using Natural Temperature Profiling: I. Conceptual Basis
Authors: Silliman S. , Robinson R.
Published: August 2005

In situ delineation of fracture characteristics is a difficult and often time‐consuming task. Several advantages would be gained from the development of simple field techniques which provide direct evidence of such parameters as fracture connectivity, fracture orientation, or fracture aperture. In this paper, such a technique for delineation of fracture connectivity between boreholes is introduced. The technique is based on utilizing the natural variation of water temperature within the subsurface as a natural ground‐water tracer. In this technique, thermal response in observation boreholes induced by local pumping or injection is related to the location of interconnected fractures. The technique provides several advantages including simple equipment and time requirements, direct evidence of fracture flow between boreholes, and the ability to test without contaminating a field site. The major limitations of the technique are related to the volume of fluid movement within an observation hole and are controlled by the geometry of the flow field in the vicinity of the pumping/ injection borehole. Two case studies are briefly outlined demonstrating application of the technique to both a fractured granite and a fractured dolomite. Part II of this paper (Robinson and Silliman, in preparation) contains a detailed discussion of the application of this technique to the second, fractured dolomite, case study.
Physical Controls on Hydrochemical Variability in the Inner Bluegrass Karst Region of Central Kentuckya
Authors: Scanlon B. R.
Published: August 2005

Areal and temporal variations in physical and chemical characteristics of ground water in the Inner Bluegrass Karst Region of central Kentucky were used to evaluate physical controls on hydrochemical variability. The karst region consists of flat‐lying interbedded limestones and shales. Physical attributes of the aquifer were assessed on the basis of spring discharges, static water levels in wells, and pumping tests. Areal and temporal variations in ground‐ water chemistry were determined from major‐ion analysis of water samples from 15 springs and 24 wells over a 17‐ month period.

Water samples were divided into three chemical types on the basis of the relative concentrations of the dominant ions; Ca‐Mg‐HCO3, Na‐HCO3, and Na‐Cl water. Ca‐Mg‐HCO3 water was divided further on the basis of Ca/Mg molar ratios into Ca subtype water (Ca/Mg > 6) and Ca‐Mg subtype water (Ca/Mg < 6). All springs are characterized by Ca subtype water. Pumping tests show that hydraulic conductivities in zones of Ca‐Mg‐HCO3 water are significantly higher than those in zones of Na‐HCO3 and Na‐Cl water. There is no regional trend in the distribution of these water types.

Temporal fluctuations in water chemistry correlate with seasonal fluctuations in recharge. Large seasonal variations in ionic concentrations occur primarily in Ca subtype water. Hydraulic conductivities, seasonal variations in ionic concentrations, and TDS suggest that ground‐water residence time is the primary control on the occurrence of the different water types. Differences in residence time are attributed to the presence of discontinuous, horizontal shales that control the rate and depth of active groundwater ciculation.
Numerical Identification of Parameters in Leaky Aquifers
Authors: Yeh Hund‐Der , Han Hung‐Yuang
Published: August 2005

A method using the nonlinear least‐squares and finite‐ difference Newton's method is presented to identify the parameters from pumping tests in homogeneous and isotropic leaky aquifers both for the situations with and without storage effects in the aquitard. Based on the least‐ squares approach, the sum of the squares of differences between the observed drawdowns and predicted drawdowns using the estimated parameters is minimized. The finite‐ difference Newton's method is used to solve the system of nonlinear least‐squares equations for the unknown aquifer parameters.

Comparisons of the results among the proposed method, graphical method, and sensitivity analysis method when analyzing various data are presented. The proposed method has the merit of good accuracy and quick convergence from some initial guesses.
Dissimilatory Nitrate Reduction in a Waste‐Water Contaminated Aquifer
Authors: Bulger Paul R. , Kehew Alan E. , Nelson Richard A.
Published: August 2005

Ground water beneath the McVille, North Dakota Municipal Waste‐Stabilization Ponds was studied to determine the chemical effects of seepage on a shallow unconfined aquifer. Relatively coarse‐grained glaciofluvial sediments underlie the site and facilitate transport of partially treated waste water to the water table, altering the local ground‐water chemistry.

The plume resulting from infiltration contains elevated levels of dissolved organic carbon (DOC) and ammonium in areas of low redox potential. The presence of nutrients in waters of low redox potential promotes the growth of anaerobic bacteria. Ground water containing high nitrate concentrations, due to leachate from an adjacent abandoned landfill, occurs upgradient of the ponds. These high nitrate waters, traveling downgradient, mix with the low redox potential ground water beneath and downgradient of the lagoon. Ammonium concentrations, downgradient of the waste‐stabilization ponds, are greater than ammonium levels within the ponded waste water. The abundant microbial population appears to utilize DOC and nitrate as nutrients for growth and energy. The utilization of nutrients occurs in a redox reaction, in which nitrate is apparently reduced to ammonium and carbon is oxidized. The increase in ammonium levels and decrease in nitrate levels suggests nitrate is not assimilated into cell tissue, but instead dissimilatory nitrate reduction to ammonium takes place. Dissimilatory reduction refers to reduction of a compound for its energy yield, without conversion of the compound to biomass (Ceazan et al, 1984).
Expert Opinion and Ground‐Water Quality Protection: The Case of Nitrate in Drinking Water
Authors: Rajagopal R. , Tobin Graham
Published: August 2005

Ground‐water protection strategies have been constrained by the limited consideration of varied and new options relevant to particular problems. Consequently, management practices have tended to maintain the status quo regarding legislation and water‐quality standards. To examine the responses to specific issues, we presented an analysis of the problem of nitrate contamination of ground water in the Midwest to a community of experts. Ninety‐seven individuals, through a formal questionnaire, responded to a variety of questions pertaining to the issue. They showed definite preferences in dealing with certain aspects of the problem, although there was significant variability in responses due to such factors as length of ground‐water‐related professional experience and residential status. It was clear that respondents preferred immediate preventive or corrective action in a world of incomplete knowledge over extensive research; were willing to undertake personal action to seek nitrate‐free water rather than wait for official action; and favored local and state level involvement over federal intervention. Findings based on this survey research can be used effectively in the planning of future work to establish actual preferences in communities with serious nitrate contamination problems.
Experimental Research on Permeability of Granular Media
Authors: Er‐Hui Zhao
Published: August 2005

The coefficient of permeability or hydraulic conductivity is a basic parameter of a granular media. It is difficult to determine the coefficient of permeability because it depends on many factors. According to experiments and analysis, we think the permeability of a granular media results from the unified effect of an external factor—the hydraulic gradient, and internal factors—properties of the granular media itself and the fluid; therefore, the permeability of a granular media can be determined by a sieve analysis and physical characteristics of the fluid. Based on theoretical analysis and experiments, we advance a unified expression to calculate the coefficient of permeability of a granular media. The precision of the formula is up to practical requirements based on inspection of experimental data. The formula is
Geostatistical Estimation of Hydraulic Head Gradients
Authors: Philip Ross D. , Kitanidis Peter K.
Published: August 2005

This paper describes a technique for estimating gradients of hydraulic head from scattered measurements of head. Gradients of hydraulic head control the flow of ground water in aquifers and their determination is an important part of any ground‐water investigation. A best linear unbiased estimator of hydraulic head is derived which allows direct estimation of head gradients and mean square estimation error. The hydraulic head is broken into continuous and discontinuous components. The discontinuous component, which represents random measurement error and small‐scale variability, is filtered from the measurements. The technique is applied to measurements of head in the Wolfcamp aquifer in northern Texas.
WQSTAT II: A WATER QUALITY STATISTICS PACKAGE
Authors: Loftis J. C. , Phillips R. D. , Ward R. C. , Taylor C. H.
Published: August 2005

Abstract. Statistical analysis of monitoring data is becoming a necessary part of many ground‐ and surface‐water quality management activities. To meet this need a statistical software package for microcomputers called WQStat II has been designed and produced specifically for water quality applications. The software provides tools for data management, summarizing data characteristics, analyzing trends, comparing medians of two or more groups of data, and evaluating excursions or standards violations. To minimize problems associated with nonnormal data and nondetects, WQStat relies primarily on graphical and nonparametric approaches.