bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional cerebral volume measurements in late‐life depression: relationship to clinical correlates, neuropsychological impairment and response to treatment
Authors: Simpson Steve W. , Baldwin R. C. , Burns Alistair , Jackson Alan
Published: August 2002

Background

Elderly people who develop depression have demonstrable changes in cerebral structure but little is known of the relationship between regional cerebral volumes, treatment response and cognitive impairment.

Method

Forty‐four patients with major depression diagnosed according to DSM‐IIIR criteria underwent magnetic resonance imaging and regional cerebral volumes were quantified using multispectral analysis. Response to antidepressant treatment was assessed prospectively and a neuropsychological test battery was administered.

Results

There was a trend for smaller fronto‐temporal volumes in the treatment‐resistant patients. Impaired immediate working memory was linked with reduced frontal and parietal lobe volume and impaired short‐term memory functioning was associated with reduced temporal lobe volume. Ventricular enlargement was associated with prior administration of electro‐convulsive therapy, poor physical health and later age at onset of first episode of depression.

Conclusion

In late‐life depression, brain changes should not preclude vigorous antidepressant treatment. Regional cerebral volume changes may be a complication of poor physical health and are associated with memory dysfunction even upon recovery from depression. Copyright © 2001 John Wiley & Sons, Ltd
Citalopram augmentation of antipsychotic treatment in older schizophrenia patients
Authors: Kasckow John W. , Mohamed Somaia , Thallasinos Arthur , Carroll Brendan , Zisook Sidney , Jeste Dilip V.
Published: August 2002

Background

Depressive symptoms are common in older patients with schizophrenia; yet, few studies have examined the usefulness of antidepressants in this population.

Objective

We conducted a 10‐week single‐blind trial of citalopram (20–40 mg/day) vs no citalopram augmentation in 19 middle‐aged and elderly patients with schizophrenia hospitalized for more than six of the last 12 months. At study‐entry, the patients had been on stable doses of antipsychotics for at least two weeks, and had a 17‐item Hamilton Depression Rating (HAM‐D) scale score of 12 or greater. Nine patients were randomly assigned to citalopram augmentation, and 10 to no augmentation of antipsychotics.

Results

Patients in both groups improved on positive and negative symptoms, but the citalopram group had significantly greater improvement in HAM‐D and Clinical Global Impression Scale scores than the control group. There were no major side effects.

Conclusion

Larger double‐blind studies are needed to follow up on these preliminary findings. Copyright © 2001 John Wiley & Sons, Ltd.
Do visuospatial and constructional disturbances differentiate frontal variant of frontotemporal dementia and Alzheimer's disease? An experimental study of a clinical belief
Authors: Grossi Dario , Fragassi Nina Antonetta , Chiacchio Laura , Valoroso Luigi , Tuccillo Rosaria , Perrotta Concetta , Rapone Paola , Conchiglia Giovanna , Trojano Luigi
Published: August 2002

Background

In recent years several attempts have been made to distinguish frontotemporal dementia (FTD) from Alzheimer's disease (AD) on neuropsychological grounds; in particular, it has been suggested that FTD patients show spared spatial abilities with respect to AD patients.

Objective

We aimed at verifying whether patients with the frontal variant of frontotemporal dementia (fv‐FTD) and AD patients perform differently on visuospatial and constructional tasks.

Methods

We assessed a wide range of visuospatial abilities and provided a qualitative analysis of constructional performances in 14 fv‐FTD patients and 11 AD patients, matched for general cognitive abilities.

Results

The two groups of patients achieved similar scores on two copying tasks, presented similar drawing procedures in copying Rey complex figure and made a similar quantitative and qualitative pattern of errors in copying simple geometrical drawings. Moreover, no significant difference was found between fv‐FTD and AD patients on a specific battery for visuospatial abilities.

Conclusions

Our data and a review of the literature suggest that basic visuospatial and constructional skills cannot be taken as a reliable diagnostic criterion for distinguishing fv‐FTD and AD at a mild to moderate disease stage and that the clinical belief of spared spatial abilities in fv‐FTD has to be referred to the lack of topographic disorientation in comparison to AD. Copyright © 2002 John Wiley & Sons, Ltd.
Timing and connectivity in the human somatosensory cortex from single trial mass electrical activity
Authors: Ioannides Andreas A. , Kostopoulos George K. , Laskaris Nikolaos A. , Liu Lichan , Shibata Tadahiko , Schellens Marc , Poghosyan Vahe , Khurshudyan Ara
Published: August 2002

Parallel‐distributed processing is ubiquitous in the brain but often ignored by experimental designs and methods of analysis, which presuppose sequential and stereotypical brain activations. We introduce here a methodology that can effectively deal with sequential and distributed activity. Regional brain activations elicited by electrical median nerve stimulation are identified in tomographic estimates extracted from single trial magnetoencephalographic signals. Habituation is identified in both primary somatosensory cortex (SI) and secondary somatosensory cortex (SII), often interrupted by resurgence of strong activations. Pattern analysis is used to identify single trials with homogeneous regional brain activations. Common activity patterns with well‐defined connectivity are identified within each homogeneous group of single trials across the subjects studied. On the contralateral side one encounters distinct sets of single trials following identical stimuli. We observe in one set of trials sequential activation from SI to SII and insula with onset of SII at 60 msec, whereas in the other set simultaneous early co‐activations of the same two areas. Hum. Brain Mapping 15:231–246, 2002. © 2002 Wiley‐Liss, Inc.
Nonparametric permutation tests for functional neuroimaging: A primer with examples
Authors: Nichols Thomas E. , Holmes Andrew P.
Published: August 2002

Requiring only minimal assumptions for validity, nonparametric permutation testing provides a flexible and intuitive methodology for the statistical analysis of data from functional neuroimaging experiments, at some computational expense. Introduced into the functional neuroimaging literature by Holmes et al. ([1996]: J Cereb Blood Flow Metab 16:7–22), the permutation approach readily accounts for the multiple comparisons problem implicit in the standard voxel‐by‐voxel hypothesis testing framework. When the appropriate assumptions hold, the nonparametric permutation approach gives results similar to those obtained from a comparable Statistical Parametric Mapping approach using a general linear model with multiple comparisons corrections derived from random field theory. For analyses with low degrees of freedom, such as single subject PET/SPECT experiments or multi‐subject PET/SPECT orfMRI designs assessed for population effects, the nonparametric approach employing a locally pooled (smoothed) variance estimate can outperform the comparable Statistical Parametric Mapping approach. Thus, these nonparametric techniques can be used to verify the validity of less computationally expensive parametric approaches. Although the theory and relative advantages of permutation approaches have been discussed by various authors, there has been no accessible explication of the method, and no freely distributed software implementing it. Consequently, there have been few practical applications of the technique. This article, and the accompanying MATLAB software, attempts to address these issues. The standard nonparametric randomization and permutation testing ideas are developed at an accessible level, using practical examples from functional neuroimaging, and the extensions for multiple comparisons described. Three worked examples from PET andfMRI are presented, with discussion, and comparisons with standard parametric approaches made where appropriate. Practical considerations are given throughout, and relevant statistical concepts are expounded in appendices. Hum. Brain Mapping 15:1–25, 2001. © 2001 Wiley‐Liss, Inc.
Pyridinium dichlorophosphinomethylides
Authors: Bansal Raj K. , Gupta Neelima , Baweja Mukta , Hemrajani Leena , Jain Vimal K.
Published: August 2002

Seven new pyridinium dichlorophosphinomethylides 2 have been obtained from dichlorophosphinylation of the pyridinium methylides generated in situ. 2 give 1,3‐bis(alkoxycarbonyl)‐2‐phosphaindolizines 4 through 1,5‐electrocyclization of the intermediate, bis(pyridinium ylidyl)phosphenium chloride 3 which is generated either from disproportionation of 2 or from the reaction of 2 with pyridinium methylide. Formation of 3 has been confirmed by carrying out a crossed reaction. 3‐Substituted 2 forms 4 regiospecifically. Intramolecular 1,5‐cyclocondensation of 2‐methylpyridinium dichlorophosphinomethylide is preferred over its disproportionation. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:602–609, 2001
Synthesis of phosphorylated 1,3,5‐oxadiazines via N‐acyltrifluoroacetimidoylphosphonates
Authors: Onys'ko Petro P. , Sinitsa Aleksei A. , Pirozhenko Vladimir V. , Chernega Aleksandr N.
Published: August 2002

N‐Benzoyl‐ and N‐methoxycarbonyltrifluoroacetimidoylphosphonates react with dimethylcyanamide in a [4+2]‐cycloaddition to give 4‐phosphorylated 1,3,5‐oxadiazines. The structures of the products were confirmed by NMR (1H, 13C, 19F, 31P) and IR spectra and by XRD analysis. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:22–26, 2002; DOI 10.1002/hc.1102
Recentering Learning: An Interdisciplinary Approach to Academic and Student Affairs
Authors: Guarasci Richard
Published: August 2002

An old campus is revitalized by a new vision for student learning built on student and academic affairs collaboration.
Academic background and admissions to American universities
Authors: Abel Charles F. , Sementelli Arthur J.
Published: August 2002

International students who apply to U.S. institutions of higher education need to understand how their academic credentials will be evaluated, and both international students and American students who study abroad need to be aware of how credits from a foreign university are evaluated if they are to be transferred.
On the societal value of health care: what do we know about the person trade‐off technique?
Authors: Green Colin
Published: August 2002

The person trade‐off (PTO) technique has been suggested as a means of eliciting social preferences for health care, both the valuation of health care interventions and, more recently, to inform on the weights that society may attach to other decision‐making criteria (e.g. the severity of a patients pre‐treatment condition). Given the increased attention afforded to the PTO technique, this review examines the current evidence to inform on the ability of the PTO to provide a measure of social preference. Applying criteria of practicality, reliability and validity to empirical and theoretical contributions to the PTO literature, the review finds that the technique has limited empirical support. Applications of the PTO have been in a largely experimental setting, the reliability of the PTO is unproven and the empirical validity of the technique, in terms its ability to reflect actual preferences, remains unclear. In the broader context of the valuation of health states or outcomes, all techniques are open to criticism. Given this position, the review finds support for the potential of the PTO in the assessment of the societal value of health care, and it supports further empirical inquiry on the PTO. Copyright © 2001 John Wiley & Sons, Ltd.
Estimating hospital costs with a generalized Leontief function
Authors: Li Tong , Rosenman Robert
Published: August 2002

This paper estimates a long‐run hospital cost function with multiple outputs and inputs using a panel data set from Washington State hospitals during 1988–1993. We find that with our data the generalized Leontief function is more appropriate than a translog for estimating hospital cost functions. With respect to hospital costs, we find that hospitals readily adjust the use of intermediate products. Radiology, therapies and surgery, and other inpatient days, all serve as substitutes for core inpatient days. Outpatient services are found to be complementary to core inpatient services, indicating that the growth of stand‐alone outpatient clinics might increase the costs of providing healthcare services. Our analysis finds that hospitals show significant economies of scale, but there is a limited amount of evidence of scope economies. Also, there is some evidence that profit‐seeking hospitals achieve some of their goals by controlling costs, and that diagnostically related groups (DRG)‐based Medicare services are effective in getting hospitals to control costs. Copyright © 2001 John Wiley & Sons, Ltd.
Cost efficiency of US hospitals: a stochastic frontier approach
Authors: Rosko Michael D.
Published: August 2002

This study examined the impact of managed care and other environmental factors on hospital inefficiency in 1631 US hospitals during the period 1990–1996. A panel, stochastic frontier regression model was used to estimate inefficiency parameters and inefficiency scores.

The results suggest that mean estimated inefficiency decreased by about 28% during the study period. Inefficiency was negatively associated with health maintenance organization (HMO) penetration and industry concentration. It was positively related with Medicare share and for‐profit ownership status. Copyright © 2001 John Wiley & Sons, Ltd.
Cost prediction models for the comparison of two groups
Authors: Willan Andrew R. , O'Brien Bernie J.
Published: August 2002

For trial‐based economic evaluation where patient‐specific cost data are not routinely available, cost prediction models are commonly used to estimate total cost for each patient. Typically, multiple regression techniques are used on data from diagnosis‐matched, non‐trial patients (where patient‐level cost data are available) to model cost as a function of covariates that are observed on the trial subjects (e.g. length of hospital stay, procedures, etc.). The estimated beta coefficients provide a means of estimating the total cost for each patient in the trial. However, the variability of the beta coefficients due the measurement and sampling error is seldom included in the overall variance expression for mean costs by treatment group. In this paper we provide a method for estimating this variance and provide an example application Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal screening for cystic fibrosis: an economic analysis
Authors: Nielsen Randi , Gyrd‐Hansen Dorte
Published: August 2002

Cystic fibrosis (CF) is the most common life‐shortening genetically transmitted disease in Denmark with a birth prevalence of 1 in 4700, resulting in 12–15 new cases of cystic fibroses annually.

The aim of this study is to disclose the societal resource implications of introducing a population wide prenatal screening programme for cystic fibrosis in Denmark. The present analysis is limited to the monetary consequences of introducing a screening programme, where costs of screening are compared to the potential benefits measured in cost savings involved if births of CF patients are avoided.

Screening costs in a Danish setting were estimated at DKK 2 771 262 (£231 438) per aborted affected fetus in the first screening round, stabilising at DKK 1 864 594 (£155 383) per aborted affected fetus at subsequent screening rounds. Comparing this figure with the estimated benefits of avoiding a CF case (DKK 2.1–4.4 million; £175 000–366 667) suggests that introducing a screening programme for cystic fibrosis will be net cost saving irrespective of the perspective of the analysis, assumptions on replacement children and method of estimating long‐term production gains/losses. Copyright © 2001 John Wiley & Sons, Ltd.
Is there a role for positron emission tomography with 18F‐fluorodeoxyglucose in the initial staging of nodal negative oral and oropharyngeal squamous cell carcinoma
Authors: Stoeckli Sandro J. , Steinert Hans , Pfaltz Madeleine , Schmid Stephan
Published: August 2002

Background

The aim of our study was to assess the value of positron emission tomography (PET) with 18F‐fluorodeoxyglucose (FDG) for the staging of clinically nodal negative necks in oral and oropharyngeal squamous cell carcinoma (SCC) using sentinel lymph node (SLN) biopsy and elective neck dissection (END) as “gold standard” for comparison.

Methods

Twelve patients (10 men, 2 women) with oral or oropharyngeal squamous cell carcinoma and no evidence of lymph node metastasis in the physical and radiologic examinations were eligible. At least 24 hours before surgery PET with FDG were performed. The SLN was localized by preoperative lymphoscintigraphy with 99m‐Tc‐Nanocoll and intraoperative use of a hand‐held gamma‐probe and selectively excised. All patients then underwent END.

Results

SLN and END revealed occult metastasis in 5 of 12 cases. SLN biopsy was accurately feasible in all 12 patients and diagnosed all 5 cases of occult metastasis (sensitivity and specificity of 100%). PET suggested two patients having occult metastasis, of which one turned out to be false positive (sensitivity 25%, specificity 88%). The mean size of the micrometastasis was 1.4 mm (range, 1.2–1.5 mm).

Conclusions

PET with FDG turned out to have a poor sensitivity and specificity in revealing occult metastasis and has no role for the evaluation of otherwise clinically N0 necks. The failure to detect micrometastasis by PET is due to the technical limitations of resolution (4–5 mm). SLN biopsy, with END in cases of positive SLN, provides a highly accurate staging of N0 necks in oral and oropharyngeal carcinoma. Patients with negative SLN could be spared the risks and the morbidity of END. © 2002 Wiley Periodicals, Inc. Head Neck 24: 345–349, 2002; DOI 10.1002/hed.10057
Sympathetic paraganglioma as an unusual cause of Horner's syndrome
Authors: Moyer Jeffrey S. , Bradford Carol R.
Published: August 2002

Background

Paragangliomas are rare tumors arising from paraganglionic tissue of neural crest origin. They are present in any location where autonomic ganglia are found. The most common location in the head and neck is the carotid body, followed by the jugular bulb and vagus nerve.

Methods

A 30‐year‐old woman with a slowly growing left neck mass, aniscoria, and left eyelid ptosis was found to have a vascular tumor consistent with a paraganglioma arising near the left carotid bifurcation. After preoperative embolization, the patient underwent resection of the tumor.

Results

The tumor was found to be arising from the left sympathetic trunk and did not involve any other surrounding structures. Histopathologic analysis revealed the typical findings of a paraganglioma.

Conclusions

Sympathetic paragangliomas are exceedingly rare tumors in the head and neck and should be considered in the differential diagnosis when clinical and radiographic evidence suggest a paraganglioma. The presentation is typically a slow‐growing neck mass with the presence of an ipsilateral Horner's syndrome. © 2001 John Wiley & Sons, Inc. Head Neck 23: 338–342, 2001.
The pectoralis major myocutaneous flap: Is the subclavicular route safe?
Authors: Kerawala Cyrus J. , Sun Jian , Zhang Zhi‐yuan , Guoyu Zhou
Published: August 2002

Background

The pectoralis major myocutaneous flap has a proven track record as a reconstructive tool, but excessive bulk and a limited arc of rotation can be problematic. Although this can be addressed by passing the pedicle deep to the clavicle, some authors consider that this modification may compromise the flap. This prospective study therefore sought to compare the supraclavicular and subclavicular routes with particular emphasis on potential vascular sequelae.

Methods

One‐hundred patients were randomly allocation into two groups. Following flap harvest, the pedicle was passed in either a supraclavicular or subclavicular plane depending upon allocation. The survival rate and complications of each flap were assessed at 1 month.

Results

Total flap necrosis occurred in three (7.0%) of the subclavicular flaps and two (3.5%) of the supraclavicular flaps. This difference was not significant (p = .77). Likewise no statistical difference was noted between the rates of partial flap necrosis, fistula formation infection, or secondary hemorrhage in either group.

Conclusions

The subclavicular route addresses the problem of pectoralis major myocutaneous flap bulk and may increase the arc of rotation of the flap without significantly compromising its vascular supply. © 2001 John Wiley & Sons, Inc. Head Neck 23: 879–884, 2001.
The professional working environment consultant—A new actor in the health and safety arena
Authors: Limborg Hans Jørgen
Published: August 2002

This article examines the development of the professionalized working environment activities as they are executed in the Danish Occupational Health Service (OHS). In an historical analysis of OHS, the development of professional approaches to the working environment is shown to have shifted in focus from: an early concern with the control of occupational diseases and machine safety, to a more technical prevention emphasis in the early 1980s, through to a change agent and process consultant approach. The article concludes that we are entering a new era for cooperation with new role models for working environment professionals. © 2001 John Wiley & Sons, Inc.
Structured implementation of information systems for concurrent engineering
Authors: Chung Walter W.C. , Chik Stanley K.O.
Published: August 2002

This article presents a collaboration approach to assimilate the best practice of concurrent engineering (CE) in a small manufacturing enterprise for gaining sustainable improvements. The major challenge in CE is sharing a mental model of parallel working across departments in a company to shorten the cycle time, and across organizations to form a supply chain for global competition. Action learning is found useful to develop self‐discipline in individuals to initiate changes and align the views with others both inside and outside the company for a vested interest to use information systems to make innovations for gaining competitive advantage. © 2001 John Wiley & Sons, Inc.
Dorsal/ventral hippocampus, fornix, and conditioned place preference
Authors: Ferbinteanu Janina , McDonald R.J.
Published: August 2002

Conditioned place preference (CPP) is a learning paradigm requiring formation of associations between reward and particular locations. White and McDonald (Behav Brain Res 1993;55:269–281) demonstrated that amygdala (AMG) lesions impair, while fornix (Fx) lesions enhance learning of this task. In the present experiments, we replicated the effects of AMG and Fx lesions, but we also found that complete hippocampal (HPC) lesions interfere with normal performance. Thus, the effects of Fx and HPC lesions on CPP are opposite. This is in contrast with spatial learning in the water maze. Because it has been demonstrated that damage of dorsal HPC interferes to a greater extent with spatial learning than damage of ventral HPC, we also tested animals with either dorsal or ventral HPC disruptions on CPP. Lesions limited to dorsal HPC were followed by impairment on this task. In contrast, lesions limited to ventral HPC resulted in enhanced learning. We argue that Fx and HPC lesions do not have interchangeable effects in all learning paradigms. To explain the complex pattern of results presently obtained, we propose a novel hypothesis regarding behavioral functions of HPC neural circuits. Implications regarding the interaction between memory systems are also considered. Hippocampus 2001;11:187–200. © 2001 Wiley‐Liss, Inc.
Health sector reform and STD/AIDS control in resource poor settings—the case of Tanzania
Authors: Hanson Stefan
Published: August 2002

Integration in health sector reform tends to mean horizontal interaction between vertical programmes. This can result in a larger more complex system than a set of individual vertical programmes. This article looks at the HIV/AIDS programme in Tanzania and the possible impact of system‐wide health sector reform involving ‘decentralization’ and horizontal integration. It implies that the build‐up to reform is likely to be costly, at least initially (although eventually the system may become more cost‐effective). Integration can thus save resources, but it will also demand additional inputs, and may lead to reduced service output if operations depend on horizontal functions that fail to deliver. The objective of reform must be to create a reasonably sized, well‐balanced, system which aims to maximize the output of quality services, both preventive and curative, and to facilitate community efforts to improve health. It is doubtful whether present reform efforts in Tanzania will contribute to more effective services, if not based on a more thorough analysis adapted to the local situation and given considerably more resources, both human and financial. There is also a risk that key preventive programmes, such as those aimed at the control of STD/AIDS, will be further weakened because of both integration with subsequent dependence on poorly functioning horizontal units and reduction in allocated resources. Copyright © 2000 John Wiley & Sons, Ltd.
Differences in health insurance and health service utilization among Asian Americans: method for using the NHIS to identify unique patterns between ethnic groups
Authors: Ryu Hosihn , Young Wendy B. , Kwak Hoil
Published: August 2002

The purpose of this study is to outline a method to identify the characteristics of socioeconomic variables in determining the differences in health insurance coverage and health services utilization patterns for different ethnic groups, using the behavioural model of health service utilization. A sample drawn from Asian American adult respondents to the 1992, 1993, and 1994 National Health Interview Surveys (NHIS) in the USA formed the data set. The results showed Asian Americans as not being homogeneous. There were distinctly different demographic and socioeconomic characteristics between six Asian American ethnic groups that affect health insurance coverage and health service utilization. The study method is useful for constructing health policy and services to address the general public need without adversely affecting smaller minority groups. Secondary analysis of well‐constructed national data sets such as the specific Asian ethnic groups in NHIS, offers a rich method for predicting the differential impact of specific health policies on various ethnic groups. Copyright © 2002 John Wiley & Sons, Ltd.
Strategic alignment of training, transfer‐enhancing behaviors, and training usage: A posttraining study
Authors: Montesino Max U.
Published: August 2002

This survey explored the alignment of an organization's specific training program with its strategic
direction and its practices to support usage of training on the job. The subjects, trainees and their immediate
supervisors, were participants in a targeted sales training program of a Fortune 200 pharmaceutical company
headquartered in the Midwest. This study found a low to moderate positive correlation between the perceived
alignment of training with the strategic direction of the organization and the presence of practices to support
usage of training. The group of trainees that self‐reported very high usage of training perceived a
significantly higher alignment of the training program with the strategic direction of the organization as
compared to the group of trainees that self‐reported low to high usage of training; field managers
did not differ significantly in that regard. Trainees who self‐reported very high usage of training also
reported a significantly higher presence of practices to support usage of training throughout the program than
the group of trainees that self‐reported low to high usage of training; field managers did not
differ significantly in that regard either. The study found a positive correlation between awareness of and
commitment to the strategic direction of the organization.
Managing Harassment
Authors: Bland Timothy S. , Stalcup Sue S.
Published: August 2002

Survey says: Sexual harassment complaints went up about 10% each year between 1995 and 1998! And even worse, 2 out of 3 complaints had some merit! Clearly, organizations need to learn how to manage this issue, not just be compliant with the law. This article provides interpretations of recent Supreme Court decisions for HR practitioners and new methods for managing harassment in workplaces. It may stimulate those who are reading the article to “step outside the box” and be more innovative in their approach to managing harassment in their organizations so as to create self‐sustaining environments where harassment is unwelcome. © 2001 John Wiley & Sons, Inc.
Large eddy simulation of passive scalar in complex turbulence with flow impingement and flow separation
Authors: Abe Ken‐ichi , Suga Kazuhiko
Published: August 2002

In order to reveal unknown characteristics of complex turbulent passive scalar fields, large eddy simulations in forced convection regimes have been performed under several strain conditions, including flow impingement and flow separation. By using the simulation results, relations between the dynamic and scalar fields are carefully examined. It is then confirmed that the scalar is transported by a large vortex structure near the examined regions wherever the mean shear vanishes, although in the high‐shear regions, the scalar transport is governed by a coherent structure due to the high shear strain. In addition, a priori explorations are attempted by processing the data, focusing on the derivation of a possible direction for modeling algebraically the passive scalar transport in a complex strain field. The a priori tests suggest that an expanded form of the GGDH model introducing a quadratic product of the Reynolds stresses is promising for general flow cases. © 2001 Scripta Technica, Heat Trans Asian Res, 30(5): 402–418, 2001
Caffeine (4 mg/kg) influences sustained attention and delayed free recall but not memory predictions
Authors: Kelemen William L. , Creeley Catherine E.
Published: August 2002

This experiment was conducted to examine the influence of a moderate dose of caffeine (4 mg/kg) on delayed memory, metamemory, and sustained attention. One hundred and forty‐two volunteers ingested either caffeine or placebo during a study session which included three different memory tasks (free recall, cued recall, and recognition), and they made predictions of future memory performance. On day 2, participants again ingested either caffeine or placebo and completed memory tests. Sustained attention performance was measured on both days, and caffeine reliably improved hit rates and response latencies. A reliable drug‐state interaction was detected only in the free recall test of memory. Caffeine did not affect the magnitude or accuracy of memory predictions, but there was some evidence that expectancies about caffeine were related to cognitive performance. Overall, caffeine's impact on memory and metamemory was not robust in this study. Copyright © 2001 John Wiley & Sons, Ltd.
Caffeine levels in saliva: associations with psychosocial factors and behavioural effects
Authors: Brice Carolyn , Smith Andrew
Published: August 2002

The present study had two main aims. The first was to examine associations between psychosocial factors, health‐related behaviours, regular level of caffeine consumption, time of day and levels of caffeine in saliva following acute caffeine challenges. The second aim was to determine whether individual differences in changes in performance following ingestion of caffeine were related to levels of caffeine in saliva. One hundred and forty‐four young adults participated in the study. Questionnaires were administered prior to the study to measure psychosocial characteristics, health‐related behaviours and habitual levels of caffeine consumption. Two double‐blind acute caffeine challenges were then carried out 1 week apart. Volunteers were given either placebo or 1.5 or 3 mg/kg of caffeine on each occasion. The challenges were carried out at 8 : 00, 11 : 00, 14 : 00 or 18 : 00 h so that the impact of time of day could be assessed. In the week between the two challenges the volunteers consumed either caffeinated or decaffeinated products. This allowed investigation of the effects of caffeine withdrawal on caffeine metabolism. Prior to each caffeine challenge volunteers performed a range of tasks, and a baseline saliva sample was taken. The tasks were repeated 1 h after ingestion of the caffeine, with saliva samples being taken at the start and end of the 1 h test battery. The results showed that the level of caffeine in the saliva was a good indicator of the dose of caffeine consumed and of compliance with the withdrawal manipulation. Caffeine levels were not influenced by time of day, habitual caffeine consumption, psychosocial factors or health‐related behaviours. Individual differences in caffeine levels in saliva were not related to the individual variation in the effects of caffeine on performance. Copyright © 2001 John Wiley & Sons, Ltd.
Differential effects of Ecstasy and cannabis on self‐reports of memory ability: a web‐based study
Authors: Rodgers J. , Buchanan T. , Scholey A. B. , Heffernan T. M. , Ling J. , Parrott A.
Published: August 2002

Given the legal status of MDMA (3,4‐methylenedioxymethamphetamine), or Ecstasy, face‐to‐face access to participants is sometimes difficult. The number of participants in studies of cognitive performance amongst Ecstasy users is variable, with the average being around 30. Access to a larger number of participants is clearly desirable. The present investigation accessed a larger sample size using a web‐based design. A website was developed and used for data collection. Prospective memory ability was assessed using the Prospective Memory Questionnaire. Self‐report of day‐to‐day memory performance was investigated using the Everyday Memory Questionnaire. The Drug Questionnaire assessed the use of other substances as well as Ecstasy, allowing a regression design to isolate the contribution of each substance to any variance on the cognitive measures. Preliminary findings (N = 488) indicate that there is a clear double dissociation between the impact of Ecstasy and cannabis. We found that cannabis was associated with reports of ‘here‐and‐now’ cognitive problems in short‐term and internally cued prospective memory. In contrast, Ecstasy was associated with reports of long‐term memory problems, which were more related to storage and retrieval difficulties. Copyright © 2001 John Wiley & Sons, Ltd.
Psychiatric disorders in Ecstasy (MDMA) users: a literature review focusing on personal predisposition and drug history
Authors: Soar K. , Turner J. J. D. , Parrott A. C.
Published: August 2002

3,4‐methylenedioxymethamphetamine (MDMA or Ecstasy) has been implicated in the onset of a number of psychological disorders and associated with a number of psychiatric symptoms that have persisted after cessation of the drug. This paper is a review of the published psychiatric case studies from the last 10 years involving MDMA. Only 24% of patients had a previous psychiatric history and 34% had a psychiatric illness amongst first degree relatives. The percentage of patients not having had a personal or family history of psychiatric illness and the temporal relationship between MDMA ingestion and the experience of recurring symptoms strongly suggest a causal relationship between the drug and neuropsychiatric manifestations. Further supporting evidence comes from several studies using non‐clinical samples. Ecstasy users that don't present themselves in healthcare settings as having clinical symptoms have significantly higher scores on certain subscales of the SCL‐90 compared with Ecstasy‐naive controls, with higher pathology scores in heavier Ecstasy users. The full‐blown psychiatric cases may represent the broad end of this problematic spectrum. Copyright © 2001 John Wiley & Sons, Ltd.
Spatial and temporal variations in annual balance of North Cascade glaciers, Washington 1984–2000
Authors: Pelto Mauri S. , Riedel Jon
Published: August 2002

Since 1984, annual glacier mass balance measurements have been conducted on eight glaciers by the North Cascades Glacier Climate Project (NCGCP). Since 1993 the National Park Service (NPS) has monitored the mass balance of four glaciers, and the NCGCP an additional two glaciers. This 14 glacier monitoring network, covering an area of 14 000 km2, represents the most extensive network of mass balance measurements for alpine glaciated areas in the world. The breadth of the record allows determination of the annual variability of annual balance from glacier to glacier, and from year to year.

Data indicate a broad regional continuity in the response of these glaciers to climate. All cross‐correlation values between any pair of the 14 glaciers ranged from 0·80 to 0·98. This strong degree of correlation indicates that regional‐scale climate conditions, not local microclimates, are the primary control of glacier annual balance in the North Cascades.

Data also indicate that the annual mass balance trend for glaciers was strongly negative from 1984 to 1994 and slightly positive from 1995 to 2000. The cumulative annual mass balance for eight glaciers between 1984 and 1994 was −0·39 m year−1. From 1995 to 2000 the cumulative annual mass balance of the same eight glaciers was +0·10 m year−1, and +0·15 m year−1 for all 14 glaciers in this study.

The correlation coefficients indicate the strongly similar response, not that the specific magnitude of the annual mass balance for each glacier is the same. There is a significant annual range in the individual glacier balances, averaging 1·01 m, and in the mean annual mass balance between glaciers. All of the glaciers with more positive annual mass balances since 1995 had either significant accumulation areas extending above 2300 m, and/or are east of the zone of maximum precipitation. The glaciers with the most negative annual mass balance are those with the lowest mean elevation. The record is, as yet, too short to explain the variability of mass balance fully using climate data and seasonal mass balance data. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of urbanization on streamflow in the Atlanta area (Georgia, USA): a comparative hydrological approach
Authors: Rose Seth , Peters Norman E.
Published: August 2002

For the period from 1958 to 1996, streamflow characteristics of a highly urbanized watershed were compared with less‐urbanized and non‐urbanized watersheds within a 20 000 km2 region in the vicinity of Atlanta, Georgia: in the Piedmont and Blue Ridge physiographic provinces of the southeastern USA. Water levels in several wells completed in surficial and crystalline‐rock aquifers were also evaluated. Data were analysed for seven US Geological Survey (USGS) stream gauges, 17 National Weather Service rain gauges, and five USGS monitoring wells. Annual runoff coefficients (RCs; runoff as a fractional percentage of precipitation) for the urban stream (Peachtree Creek) were not significantly greater than for the less‐urbanized watersheds. The RCs for some streams were similar to others and the similar streams were grouped according to location. The RCs decreased from the higher elevation and higher relief watersheds to the lower elevation and lower relief watersheds: values were 0·54 for the two Blue Ridge streams, 0·37 for the four middle Piedmont streams (near Atlanta), and 0·28 for a southern Piedmont stream. For the 25 largest stormflows, the peak flows for Peachtree Creek were 30% to 100% greater than peak flows for the other streams. The storm recession period for the urban stream was 1–2 days less than that for the other streams and the recession was characterized by a 2‐day storm recession constant that was, on average, 40 to 100% greater, i.e. streamflow decreased more rapidly than for the other streams. Baseflow recession constants ranged from 35 to 40% lower for Peachtree Creek than for the other streams; this is attributed to lower evapotranspiration losses, which result in a smaller change in groundwater storage than in the less‐urbanized watersheds. Low flow of Peachtree Creek ranged from 25 to 35% less than the other streams, possibly the result of decreased infiltration caused by the more efficient routing of stormwater and the paving of groundwater recharge areas. The timing of daily or monthly groundwater‐level fluctuations was similar annually in each well, reflecting the seasonal recharge. Although water‐level monitoring only began in the 1980s for the two urban wells, water levels displayed a notable decline compared with non‐urban wells since then; this is attributed to decreased groundwater recharge in the urban watersheds due to increased imperviousness and related rapid storm runoff. Copyright © 2001 John Wiley & Sons, Ltd.
Rethinking what constitutes suspended sediment
Authors: Droppo Ian G.
Published: August 2002

Although cohesive suspended sediment is now known to be transported primarily as flocculated material, there is still a misconception of what constitutes suspended sediment. Flocs represent a complex matrix of microbial communities, organic particles (e.g. detritus, extracellular polymers and cellular debris), inorganic particles (e.g. clays and silts) and substantial interfloc spaces (pores), which allow for the retention or flow through of water. Flocculation results in significant alteration of the hydrodynamics of the constituent particles (by modifying their effective size, shape, density and porosity), thereby affecting the transport of sediment and associated contaminants. The composition and structure of a floc is in a continuous state of change as the medium in which it is transported provides the floc with further building materials, energy, nutrients and chemicals for biological growth, chemical reactions and morphological development. As such, a floc's physical (e.g. transport), chemical (e.g. contaminant adsorption) and biological (community development and contaminant biotransformation) behaviour are also in a continuous state of change, with concomitant effects on their aquatic environment as a whole. Although it is recognized that floc form will influence floc behaviour, there is still a basic lack of knowledge of the complex links between the structural components of a floc and how their individual properties and behaviours in combination with others will influence a floc's physical, chemical and biological behaviour. This paper provides a comprehensive conceptual model that links the many interrelated structural components of typical flocs and their interrelated behavioural aspects, in order to enhance our understanding of what constitutes suspended sediment. Copyright © 2001 John Wiley & Sons, Ltd.
Controls on old and new water contributions to stream flow at some nested catchments in Vermont, USA
Authors: Shanley James B. , Kendall Carol , Smith Thor E. , Wolock David M. , McDonnell Jeffrey J.
Published: August 2002

Factors controlling the partitioning of old and new water contributions to stream flow were investigated for three events in four catchments (three of which were nested) at Sleepers River Research Watershed in Danville, Vermont. In the 1993 snowmelt period, two‐component isotopic hydrograph separations showed that new water (meltwater) inputs to the stream ranged widely from 41 to 74%, and increased with catchment size (41 to 11 125 ha) (with one exception) and with open land cover (0–73%). Peak dissolved organic carbon concentrations and relative alkalinity dilution in stream water ranked in the same order among catchments as the new water fractions, suggesting that new water followed shallow flow paths. During the 1994 snowmelt, despite similar timing and magnitude of melt inputs, the new‐water contribution to stream flow ranged only from 30 to 36% in the four catchments. We conclude that the uncommonly high and variable new water fractions in streamwater during the 1993 melt were caused by direct runoff of meltwater over frozen ground, which was prevalent in open land areas during the 1993 winter. In a high‐intensity summer rainstorm in 1993, new water fractions were smaller relative to the 1993 snowmelt, ranging from 28 to 46%, but they ranked in the identical catchment order. Reconciliation of the contrasting patterns of new–old water partitioning in the three events appears to require an explanation that invokes multiple processes and effects, including:

topographically controlled increase in surface‐saturated area with increasing catchment size;

direct runoff over frozen ground;

low infiltration in agriculturally compacted soils;

differences in soil transmissivity, which may be more relevant under dry antecedent conditions.

These data highlight some of the difficulties faced by catchment hydrologists in formulating a theory of runoff generation at varying basin scales. Copyright © 2002 John Wiley & Sons, Ltd.
Modelling flow and nitrate transport in groundwater for the prediction of water travel times and of consequences of land use evolution on water quality
Authors: Molénat Jerome , Gascuel‐Odoux Chantal
Published: August 2002

A two‐dimensional model representing flow and nitrate transport in groundwater was developed and applied to a hillslope of the Kervidy catchment. The objective of the modelling was: (1) to characterize better the flow and nitrate transport in the groundwater and to determine the characteristic times of the system; (2) to explore the consequences of changes in nitrate leaching to groundwater on nitrate concentration in stream water. The finite‐difference code MODFLOW was used to simulate the distribution of hydraulic head within the groundwater. Nitrate transport was described by the convection equation solved using MT3D. MODPATH was also used to analyse flow paths and travel times in the groundwater. Four units were considered in the model: (i) the plough layer, (ii) the soil, (iii) the weathered shale and (iv) the fissured shale. Autotrophic denitrification in the shale and partly in the weathered shale was represented, as well as heterotrophic denitrification in the upper horizon of bottom land. A steady‐state average flow was assumed with a spatially uniform groundwater recharge of 2 mm day−1, corresponding to the winter mean daily recharge observed in the Kervidy catchment. Nitrate recharge rate was fixed at 100 mg l−1, which is equivalent to a nitrogen flux of 165 kg ha−1 year−1. Six scenarios of nitrate leaching changes were analysed with the model. The first two correspond to spatially uniform decreases of the nitrate recharge rate to 80 and 60 mg l−1, respectively. In the other four scenarios, nitrate recharge rate was spatially distributed along the hillslope so that the average nitrogen flux remained equal to 165 kg ha−1 year−1. Simulated hydraulic heads were similar to observed values along the hillslope, except for the summit. The transport model reproduced the spatial pattern of nitrate concentrations observed in the weathered shale groundwater, a deviation appearing only in the nearest piezometer to the stream. Travel times within the groundwater appeared to be highly variable, from a few days up to 3 years. Scenario analysis showed that a significant decrease of stream nitrate concentration can be expected following a global decrease in nitrate leaching along the hillslope. However, the fall could be very gradual in time. Copyright © 2002 John Wiley & Sons, Ltd.