bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency dependence and gender effects in visual cortical regions involved in temporal frequency dependent pattern processing
Authors: Kaufmann Christian , Elbel Gregor‐Konstantin , Gössl Christoff , Pütz Benno , Auer Dorothee P. 
Published: August 2002

AbstractNeural response to flickering stimuli has been shown to be frequency dependent in the primary visual cortex. Controversial gender differences in blood oxygen level dependent (BOLD) amplitude upon 6 and 8 Hz visual stimulation have been reported. In order to analyze frequency and gender effects in early visual processing we employed a passive graded task paradigm with a dartboard stimulus combining eight temporal frequencies from 0 to 22 Hz in one run. Activation maps were calculated within Statistical Parametric Mapping, and BOLD amplitudes were estimated for each frequency within the striate and extrastriate visual cortex. The BOLD amplitude was found to steadily rise up to 8 Hz in BA 17 and 18 with an activation plateau at higher frequencies. In addition, we observed a laterality effect in the striate cortex with higher BOLD contrasts in the right hemisphere in men and in women. BOLD response rises similarly in men and women up to 8 Hz but with lower amplitudes in women at 4, 8, and 12 Hz (30% lower). No frequency effect above 1 Hz was found in the extrastriate visual cortex. There was also a regional specific gender difference. Men activated more in the right lingual gyrus (BA 18) and the right cerebellum compared with women, whereas women showed more activation in the right inferior temporal gyrus (BA 17). The study indicates that frequency dependent processing at the cortical level is limited to the striate cortex and may be associated with a more global information processing (right hemisphere dominance), particularly in men. The finding of significantly lower BOLD amplitudes in women despite previously shown larger VEP (visual evoked potential) amplitudes might suggest gender differences in cerebral hemodynamics (baseline rCBV, rCBF, or neurovascular coupling). The regional distinction points at additional differences in psychological processing even when using a simple visual stimulus. Hum. Brain Mapping 14:28–38, 2001. © 2001 Wiley‐Liss, Inc.
Quantitative structure–property relationships in the pyridine series
Authors: Pankratov Alexei N. 
Published: August 2002

AbstractBy means of the MNDO, AM1, and PM3 methods, standard heats of formation, entropies, ionization potentials, and molecular dipole moments of the pyridine series compounds have been computed. The information on the experimental values of the above quantities has been systematized. Linear dependencies allowing a priori evaluation of thermodynamic and molecular characteristics of pyridines have been stated. Correlations of the 2,2′‐bipyridines pKa values for aqueous solutions with the gaseous‐phase proton affinities have been found. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:229–241, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10013
Asymmetric synthesis of epoxides from aromatic aldehydes and benzyl halides catalyzed by C2 symmetric optically active sulfides having a binaphthyl skeleton
Authors: Miyake Yoshihiro , Oyamada Arihiro , Nishibayashi Yoshiaki , Uemura Sakae 
Published: August 2002

AbstractReactions of aromatic aldehydes with benzyl bromide or iodide in the presence of a catalytic amount (10 mol%) of a C2 symmetric sulfide having a binaphthyl skeleton afford the corresponding trans‐stilbene oxides in moderate to good yields with moderate enantioselectivities (up to 55% enantiomeric excess). The addition of tetra‐n‐butylammonium iodide to the catalytic reaction system much improves the yield of the epoxides. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:270–275, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10028
Diisothiocyanates as heterodienophiles or dipolarophiles in the presence of α‐thioxothioamides or mesoionic thiazoles
Authors: Morel Georges , Marchand Evelyne 
Published: August 2002

AbstractReactions of α‐thioxothioamides (1) with diisothiocyanates were carried out in the hope of generating the N,N′‐bis(1,3‐thiazoline‐2‐thiones) (A). Although that purpose could not be achieved, we succeeded in preparing the monocycloadducts 7 from the phenylene‐1,2‐diisothiocyanate (4). The benzimidazole derivatives 8 and 9 were also characterized and a mechanism was assumed to account for this intramolecular process. On the other hand, the regioselective synthesis of the N,N′‐biimidazole (13) containing the phenylene bridge was performed by the treatment of the 5‐aminothiazolium chloride (2) with the diisothiocyanate (4) in a basic medium. The mesoionic derivative 13 probably arises from the monoimidazolium‐4‐thiolate (12) which was shown to react with the salt 2 under similar conditions to give the primary cycloadduct 14 as an intermediate towards the bis(imidazolium) (13). © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:617–624, 2001
How reliable are hospital efficiency estimates? Exploiting the dual to homothetic production
Authors: Folland Sherman T. , Hofler Richard A. 
Published: August 2002

AbstractFor scientific use, stochastic frontier estimates of hospital efficiency must be robust to plausible departures from the assumptions made by the investigator. Comparisons of alternative study designs, each well within the ‘accepted’ range according to current practice, generate similar mean inefficiencies but substantially different hospital rankings. The three alternative study contrasts feature (1) pooling vs partitioned estimates, (2) a cost function dual to a homothetic production process vs the translog, and (3) two conceptually valid but empirically different cost‐of‐capital measures. The results suggest caution regarding the use of frontier methods to rank individual hospitals, a use that seems to be required for reimbursement incentives, but they are robust when generating comparisons of hospital group mean inefficiencies, such as testing models that compare non‐profits and for‐profits by economic inefficiency. Demonstrations find little or no efficiency differences between these paired groups: non‐profit vs for‐profit; teaching vs non‐teaching; urban vs rural; high percent of Medicare reliant vs low percent; and chain vs independent hospitals. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluating the donor site after harvest of free jejunum grafts
Authors: Uchiyama Kiyotaka , Kimata Yoshihiro , Ebihara Satoshi , Nakatsuka Takashi , Harii Kiyonori 
Published: August 2002

AbstractBackgroundFree jejunal grafts are commonly used for reconstruction after surgery for hypopharyngeal and cervical esophageal cancer. However, few reports have addressed postoperative morbidity at the abdominal donor site.MethodsPreoperative morbidity and postoperative complications were analyzed in 126 patients in whom free jejunal grafts had been harvested from 1992 through 1996.ResultsAlthough 27 patients had previously undergone abdominal surgery, there was no correlation between previous abdominal surgery and abdominal complications after graft harvest (p > .25). Abdominal complications were not correlated with patient age (p > .25).ConclusionsOur findings suggest that previous abdominal surgery (except on the ileum) and patient age are not contraindications to free jejunal graft harvest. © 2002 Wiley Periodicals, Inc.
Phase precession and phase‐locking of hippocampal pyramidal cells
Authors: Bose Amitabha , Recce Michael 
Published: August 2002

AbstractWe propose that the activity patterns of CA3 hippocampal pyramidal cells in freely running rats can be described as a temporal phenomenon, where the timing of bursts is modulated by the animal's running speed. With this hypothesis, we explain why pyramidal cells fire in specific spatial locations, and how place cells phase‐precess with respect to the EEG theta rhythm for rats running on linear tracks. We are also able to explain why wheel cells phase‐lock with respect to the theta rhythm for rats running in a wheel. Using biophysically minimal models of neurons, we show how the same network of neurons displays these activity patterns. The different rhythms are the result of inhibition being used in different ways by the system. The inhibition is produced by anatomically and physiologically diverse types of interneurons, whose role in controlling the firing patterns of hippocampal cells we analyze. Each firing pattern is characterized by a different set of functional relationships between network elements. Our analysis suggests a way to understand these functional relationships and transitions between them. Hippocampus 2001;11:204–215. © 2001 Wiley‐Liss, Inc.
The demand for child curative care in two rural thanas of Bangladesh: effect of income and women's employment
Authors: Levin Ann , Rahman M. A. , Quayyum Zahidul , Routh Subrata , Barkat‐e‐Khuda  
Published: August 2002

AbstractThis paper seeks to investigate the determinants of child health care seeking behaviours in rural Bangladesh. In particular, the effects of income, women's access to income, and the prices of obtaining child health care are examined. Data on the use of child curative care were collected in two rural areas of Bangladesh—Abhoynagar Thana of Jessore District and Mirsarai Thana of Chittagong District—in March 1997. In estimating the use of child curative care, the nested multinomial logit specification was used.The results of the analysis indicate that a woman's involvement in a credit union or income generation affected the likelihood that curative child care was used. Household wealth decreased the likelihood that the child had an illness episode and affected the likelihood that curative child care was sought. Among facility characteristics, travel time was statistically significant and was negatively associated with the use of a provider. Copyright © 2001 John Wiley & Sons, Ltd.
Hold the Line: An Examination of Line vs. Staff Differences
Authors: Church Allan H. , Waclawski Janine 
Published: August 2002

AbstractDespite common perceptions about the differences between line and staff personnel, few studies have provided answers as to which group is more effective. This study explores in detail key differences in managerial strengths between 46 line managers and 52 staff professionals in one of the fastest growing, highly service‐oriented retail organizations in the United States. Using behavioral data from a developmental multirater feedback effort, results suggest that staff personnel were more modest and accurate in their self‐assessments, while line managers were more service‐oriented but significantly weaker at relationships, openness to new ideas, demonstrating respect, and adaptability to change. © 2001 John Wiley & Sons, Inc.
The influence of three months of methylphenidate treatment on platelet‐poor plasma biogenic amine levels in boys with attention deficit hyperactivity disorder
Authors: Spivak B. , Vered Y. , Yoran‐Hegesh R. , Graff E. , Averbuch E. , Vinokurow S. , Weizman A. , Mester R. 
Published: August 2002

AbstractAttention deficit hyperactivity disorder (ADHD) is related to dysregulation in the activity of brain monoamines. The aim of the present study was to assess the impact of three months' methylphenidate (MPH) treatment on platelet‐poor plasma (PPP) norepinephrine (NE), dopa and serotonin (5‐HT) levels as well as on ADHD symptomatology. Three months of MPH treatment in 16 ADHD boys, aged 11.4 ± 1.6 years, resulted in a significant reduction in PPP NE levels (p < 0.05). A tendency towards a reduction of PPP 5‐HT and dopa levels was detected (p < 0.1 for both). The decrease in PPP biogenic amine levels after three months of MPH treatment was accompanied by a significant reduction in all psychometric characteristics of ADHD. This result indicates the possible role of overactivity of the noradrenergic system in the pathophysiology of ADHD and suggests that the MPH therapeutic action may be related to stimulant‐induced inhibitory effect on the noradrenergic system. Copyright © 2001 John Wiley & Sons, Ltd.
Sources of stream sulphate in headwater catchments in Otter Creek Wilderness, West Virginia, USA
Authors: Fitzhugh Ross D. , Furman Tanya , Korsak Andrea K. 
Published: August 2002

AbstractUpland forested catchments in the Appalachian Plateau region receive among the greatest rates of atmospheric sulphur (S) deposition in the eastern USA, although coal mines and S‐bearing minerals in bedrock may also contribute to stream acidity in this region. Watershed mass balance and stable S isotopic values (δ34S) of sulphate (SO42−) were used to assess the contributions to stream SO42− from atmospheric and lithogenic sources at Yellow Creek (YC), a headwater catchment on the Appalachian Plateau in West Virginia. Oxygen isotopic values (δ18O) of water were used to study catchment hydrology. Stream output of SO42− was c. 60% of atmospheric S deposition during a relatively dry year, whereas atmospheric S input was nearly balanced by stream output during a year with above normal amounts of precipitation. The temporal patterns and values of δ34S were similar between bulk precipitation and stream water at two upper elevation sites. At the lowest elevation site, stream δ34S values were similar to bulk precipitation values during the dormant season but were slightly lower than precipitation during the low‐flow summer, probably as the result of a greater proportion of stream water being derived from deep hydrological flowpaths that have contacted S‐bearing minerals with low δ34S values in coal seams. Stream δ34S values at YC were significantly higher than at Coal Run, a catchment containing abandoned coal prospects and having a greater amount of S‐bearing minerals than YC. Results suggested that lithogenic S is a relatively minor source and that atmospheric deposition is the principal source of stream SO42−, and thus stream acidity, at YC. Copyright © 2001 John Wiley & Sons, Ltd.
The role of overland flow and subsurface flow on the spatial distribution of soil moisture in the topsoil
Authors: van Asch Th. W. J. , van Dijck S. J. E. , Hendriks M. R. 
Published: August 2002

AbstractMany investigations show relationships between topographical factors and the spatial distribution of soil moisture in catchments. However, few quantitative analyses have been carried out to elucidate the role of different hydrological processes in the spatial distribution of topsoil moisture in catchments. A spatially distributed rainfall—runoff model was used to investigate contributions of subsurface matric flow, macropore flow and surface runoff to the spatial distribution of soil moisture in a cultivated catchment. The model results show that lateral subsurface flow in the soil matrix or in macropores has a minor effect on the spatial distribution of soil moisture. Only when a perched groundwater table is maintained long enough, which is only possible if the subsurface is completely impermeable, may a spatial distribution in moisture content occur along the slope. Surface runoff, producing accumulations of soil moisture in flat flow paths of agricultural origin (field boundaries), was demonstrated to cause significant spatial variations in soil moisture within a short period after rainfall (<2 days). When significant amounts of surface runoff are produced, wetter moisture conditions will be generated at locations with larger upstream contributing areas. Copyright © 2001 John Wiley & Sons, Ltd.
On constraining TOPMODEL hydrograph simulations using partial saturated area information
Authors: Blazkova S. , Beven K. J. , Kulasova A. 
Published: August 2002

AbstractThis study uses field observations of the extent of saturated area over limited areas of the small Uhlirska catchment (1·87 km2) in the Czech Republic in calibrating the parameters of a version of TOPMODEL. The field information is used within the GLUE methodology, which involves evaluating many different randomly chosen parameter sets within the chosen model structure. The different parameter sets are evaluated on performance in both discharge prediction and prediction of the observed saturated areas using appropriate likelihood measures. The results show that the saturated area information results in a strong constraint of the transmissivity parameter of the model, but that the other parameters show good fits across most of the range over which they are sampled. Quite different posterior distributions for the transmissivity parameter are found for the two different years of data used in conditioning the model. The effect on the prediction bounds for stream discharges is much less, perhaps because the transmissivity parameter combines with different values of the other parameters in the two years to capture the dominant modes of discharge response of the catchment. Copyright © 2002 John Wiley & Sons, Ltd.
Aspects of river ice hydrology in Japan
Authors: Hirayama Kenichi , Yamazaki Makoto , Tao Shen Hung 
Published: August 2002

AbstractRivers in northern Japan are subjected to ice formation each winter. They are typically very steep with rapid changes in channel slope. As a result, ice covers are usually discontinuous with open water sections. Winter discharges in Japanese rivers are usually very small. Water temperature and ice production in these streams are very sensitive to the change in air temperature. The open water sections enable the formation of frazil and anchor ice during the winter. Owing to the relatively stable winter weather and heavy snow cover, premature break‐up and ice jams rarely occur, even though the channel geometry of these rivers is favourable for their occurrence. In this paper, hydrometeorological factors related to ice‐cover formation, frazil and anchor‐ice development, and ice‐jam formation, as well as measurements of the undercover discharge in rivers in northern Japan are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative evaluation of oxidative stress, chronic inflammatory indices and leptin in cancer patients: Correlation with stage and performance status
Authors: Mantovani Giovanni , Macciò Antonio , Madeddu Clelia , Mura Loredana , Gramignano Giulia , Lusso Maria Rita , Mulas Carlo , Mudu Maria Caterina , Murgia Viviana , Camboni Paolo , Massa Elena , Ferreli Luca , Contu Paolo , Rinaldi Augusto , Sanjust Enrico , Atzei Davide , Elsener Bernhard 
Published: August 2002

AbstractIn advanced cancer patients, the oxidative stress could take place either at the onset of disease or as a function of disease progression. To test this hypothesis, the following parameters were investigated: the erythrocyte activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), the serum activity of glutathione reductase (GR) and the serum total antioxidant status (TAS). The total antioxidant capacity of plasma LMWA was evaluated by the cyclic voltammetry methodology. We further determined the serum levels of proinflammatory cytokines (IL‐6 and TNFα), IL‐2, leptin and C‐reactive protein (CRP). All of these parameters have been correlated with the most important clinical indices of patients such as Stage of disease, ECOG PS and clinical response. Eighty‐two advanced stage cancer patients and 36 healthy individuals used as controls were included in the study. Our findings show that SOD activity was significantly higher in cancer patients than in controls and GPx activity was significantly lower in cancer patients than in controls. Serum values of IL‐6, TNFα and CRP were significantly higher in patients than in controls. Serum leptin values of cancer patients were significantly lower than controls. SOD activity increased significantly from Stage II/ECOG 0‐1 to Stage IV/ECOG 0–1, whereas it decreased significantly in Stage IV/ECOG 3. GPx activity decreased significantly in Stage IV/ECOG 2–3. An inverse correlation between ECOG PS and serum leptin levels was found. Serum levels of IL‐2 decreased from Stage II/ECOG 0–1 to Stage IV/ECOG 2–3. A direct correlation between Stage/ECOG PS and serum levels of both IL‐6 and CRP was observed. Cisplatin administration induced a significant increase of GPx after 24 hr. In conclusion, this is the first study that shows that several “biological” parameters of cancer patients such as antioxidant enzyme activity, cytokines, leptin and CRP strictly correlate with the most important clinical parameters of disease such as Stage and ECOG PS. © 2001 Wiley‐Liss, Inc.
Expression profiling of MMA‐1a and splice variant MMA‐1b: New cancer/testis antigens identified in human melanoma
Authors: de Wit Nicole J.W. , Weidle Ulrich H. , Ruiter Dirk J. , van Muijen Goos N.P. 
Published: August 2002

AbstractUsing high‐density oligonucleotide array analysis, we have recently compared the gene expression profiles of 2 human melanoma cell lines with marked difference in metastatic behavior after subcutaneous inoculation into nude mice (de Wit et al., Melanoma Res, in press). We identified an expressed sequence tag (EST), which we called malignant melanoma‐associated 1 (MMA‐1a), showing evident differential expression between the 2 cell lines. The MMA‐1a gene is localized on chromosome 21q22.2 and its mRNA exists of 4 exons. Homology search displayed a splice variant of MMA‐1a that lacks exon 3 and that was called MMA‐1b. Expression profiles of MMA‐1a and MMA‐1b are determined by reverse transciptase polymerase chain reaction (RT‐PCR) analysis. Among 30 different normal tissue samples, expression of MMA‐1a and MMA‐1b was exclusively found in the testis after a first PCR of 30 cycles. Even more sensitive screening achieved by performing multiple semi‐nested RT‐PCR showed no or very low expression in the other normal tissues tested. During melanocytic tumor progression, MMA‐1a and/or MMA‐1b exhibited an emergence of expression in primary melanoma (20%) and melanoma metastasis samples (30%) after only 1 round of PCR. Expression of MMA‐1a and/or MMA‐1b was also identified in other tumor cell lines and fresh tumor samples of variable origin, e.g., lung, liver, bladder and soft tissues (sarcomas). We conclude that MMA‐1a and MMA‐1b are new members of the family of cancer/testis antigens. © 2002 Wiley‐Liss, Inc.
Comparison of the effects of EM‐652 (SCH57068), tamoxifen, toremifene, droloxifene, idoxifene, GW‐5638 and raloxifene on the growth of human ZR‐75‐1 breast tumors in nude mice
Authors: Gutman Matthieu , Couillard Steeve , Roy Jenny , Labrie Fernand , Candas Bernard , Labrie Claude 
Published: August 2002

AbstractEM‐652 exerts pure antiestrogenic activity in the mammary gland and endometrium, while tamoxifen, the antiestrogen most widely used for the treatment of breast cancer, exerts mixed antiestrogenic–estrogenic activity in these tissues. Our objective was to compare the agonistic and antagonistic effects of EM‐652 with tamoxifen and 5 other antiestrogens on the growth of ZR‐75‐1 human breast xenografts in ovariectomized nude mice. During the 23 weeks of treatment at a daily oral dose of 50 μg, EM‐652 was the only compound that decreased tumor size relative to pretreatment values, whereas the 6 other antiestrogens only decreased to various extents the progression rate stimulated by estrone. Under estrone stimulation, all groups of animals had more than 60% of their tumors in the progression category except for the EM‐652–treated group, where only 7% of the tumors progressed. In the absence of estrone stimulation, progression was seen in 60%, 33%, 21% and 12% of tumors in the tamoxifen‐, idoxifene‐, toremifene‐ and raloxifene‐treated groups, respectively, while only 4% of tumors progressed in the EM‐652–treated group. The agonistic and antagonistic actions of each antiestrogen were also measured on endometrial epithelial cell thickness. Our present findings indicate that EM‐652, in addition to being the most potent antiestrogen on human breast tumor growth, has no agonistic effect in breast and endometrial tissues. Since previous data have shown benefits of EM‐652 on bone density and lipid profile, this compound could be an ideal candidate for chemoprevention of breast and uterine cancers, while protecting against osteoporosis and cardiovascular disease. © 2002 Wiley‐Liss, Inc.