bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of hydrologic alterations caused by Chi‐Chi diversion weir in Chou‐Shui Creek, Taiwan: opportunities for restoring natural flow conditions
Authors: Shiau Jenq‐Tzong , Wu Fu‐Chun 
Published: April 2004

AbstractThe Range of Variability Approach (RVA) is used to investigate the hydrologic impacts of a diversion weir on Chou‐Shui Creek, Taiwan. Thirty‐two hydrologic parameters, called Indicators of Hydrologic Alteration (IHA), are used to evaluate the flow conditions before and after weir construction. One standard deviation from the mean for each of the pre‐construction hydrologic parameters is set as the management target range. Under the prevailing diversion rules, large hydrologic alterations are observed, especially for low flows. The means of 19 hydrologic parameters presently fall outside of the targets and the average non‐attainment rate for the 32 indicators is 73.2%. Increasing the instream flow release or reducing diversions could mitigate the hydrologic impacts of weir construction. Increasing the instream flow to 40 m3/s and reducing monthly water demands by variable percentages significantly improves the altered flow conditions. Under the proposed water release and diversion scheme, 29 hydrologic parameters will fall within the management targets and the average non‐attainment rate will be reduced to 35.6%, much closer to the pre‐construction value of 25.3%. Restoring the natural flow variability is expected to promote the natural stream biota. Copyright © 2004 John Wiley & Sons, Ltd.
Negative association in uniform forests and connected graphs
Authors: Grimmett G. R. , Winkler S. N. 
Published: April 2004

AbstractWe consider three probability measures on subsets of edges of a given finite graph G, namely, those which govern, respectively, a uniform forest, a uniform spanning tree, and a uniform connected subgraph. A conjecture concerning the negative association of two edges is reviewed for a uniform forest, and a related conjecture is posed for a uniform connected subgraph. The former conjecture is verified numerically for all graphs G having eight or fewer vertices, or having nine vertices and no more than 18 edges, using a certain computer algorithm which is summarized in this paper. Negative association is known already to be valid for a uniform spanning tree. The three cases of uniform forest, uniform spanning tree, and uniform connected subgraph are special cases of a more general conjecture arising from the random‐cluster model of statistical mechanics. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
Fetal salvage with cervical cerclage
Authors: Wright E.A. 
Published: April 2004

AbstractA prospective study to evaluate the fetal salvage rate, cervical morbidity and cesarean section rate in patients with cervical incompetence using a cerclage procedure was conducted at the Jos University Teaching Hospital, Jos, Nigeria. The study group consisted of 71 patients who gave a history suggestive of cervical incompetence, had a dilated cervix at booking and included emergency patients in whom the cervix had dilated because of a febrile illness but had never undergone a cervical cerclage procedure. The fetal salvage rate was 23.7% in pregnancies occurring before and 94.4% after cervical cerclage procedure was performed. There were 57 term pregnancies, 10 pre‐term deliveries, and 4 abortions. The study clearly demonstrates the beneficial effects of cervical cerclage operations in patients who have suffered from preventable fetal losses because their incompetent cervix was undiagnosed. Our results were compared with those of other series. The diagnosis of cervical incompetence is discussed with particular emphasis on the use of screening tests in the detection and identification of cervical incompetence.
Serial serum ferritin and other hematological parameters in normal Nigerian primigravidae
Authors: Abudu O.O. , Macaulay K. , Oluboyede O.A. 
Published: April 2004

AbstractSerial hematological indices using Coulter Counter and serum ferritin using radioimmunoassay techniques were determined in 20 healthy Nigerian primigravidae with hemoglobin genotype AA. PCV fell significantly (P < 0.001) to a minimum value at 28 weeks that was 6% lower than the mean value at 8 weeks postpartum. PCV at 36 weeks was still significantly (P < 0.001) lower than the post partum value. There was an insignificant but progressive increase in MCV values throughout pregnancy. Changes in MCH and MCHC were insignificant. Ferritin levels in both the non‐pregnant and pregnant subjects were high and probably reflected the high iron content of Nigerian foods. Though the cord serum ferritin level was significantly higher (P < 0.001) than maternal ferritin at delivery there was no significant correlation between the two.
Shoulder dystocia: its incidence and associated risk factors
Authors: Sandmire H.F. , O'Halloin T.J. 
Published: April 2004

AbstractA case‐control study (73 cases, 146 controls) was conducted to evaluate maternal, obstetrical and fetal factors associated with shoulder dystocia. Several factors were identified that were associated with a higher incidence of shoulder dystocia. However, none of them accurately predict those deliveries that will be complicated by shoulder dystocia. Among the 73 shoulder dystocia cases there were no perinatal deaths and all birth‐related injuries associated with shoulder dystocia were temporary except for two cases of mild muscular weakness among 12 brachial palsy cases.
Radical vulvectomy for squamous cell carcinoma of the vulva
Authors: Ayhan Ali , Yüce K. , Pekin S. , Ayhan Ayse , Özen E. 
Published: April 2004

AbstractTwenty‐one patients with squamous cell carcinoma of the vulva who were subjected to radical vulvectomy and inguinal‐pelvic lymphadenectomy were studied. The overall mortality rate was 24%. Operative‐ and tumor‐related mortalities were 9.5% and 14.2%, respectively. Recurrence was seen in 5 patients. The most common complication was wound infection and breakdown.
Is routine episiotomy beneficial in the low birth weight delivery?
Authors: The T.G. 
Published: April 2004

AbstractThe outcome of 439 idiopathic singleton low birth weight spontaneous vertex deliveries in the university hospital of a developing country was analyzed. Any patient with a known complication of pregnancy was excluded from the study. The effects of maternal age were minimized by including only those mothers between the age of 17 and 34. The effect of maternal parity was minimized by analyzing the study in two parity groups. The birth weight distributions of the episiotomized and non‐episiotomized groups were comparable. There was no significant difference in the Apgar scores and neonatal mortality rates between these neonates delivered with an episiotomy and those without. This was the case, regardless of parity. The value of an episiotomy in the delivery of the low birth weight infant is questioned.
Early spontaneous rupture of the post myomectomy gravid uterus
Authors: Golan D. , Aharoni A. , Gonen R. , Boss Y. , Sharf M. 
Published: April 2004

AbstractRupture of a pregnant uterus is a serious threat to the mother's life and her fetus. Most of these cases have predisposing factors of which a post myomectomy scar is rare. Rupture of a post myomectomy gravid uterus usually occurs in the third trimester of pregnancy or during labor. We present a case of a very early spontaneous rupture which occurred at the 20th week of gestation in a post myomectomy uterus. To the best of our knowledge no previous report of a ruptured myomectomy scarred uterus has been described at such an early stage.
Combined subsequent development of intrauterine and extrauterine gestations
Authors: Vitoratos N. , Gregoriou O. , Chrysicopoulos A. , Zourlas P.A. 
Published: April 2004

AbstractA case of combined subsequent development of intrauterine and extrauterine pregnancy is reported. Signs of normal pregnancy associated with abdominal pains and an adnexal mass were the most significant symptoms and the final diagnosis was verified by laparoscopy in both cases. We consider that drugs for induction of ovulation (chlomiphene citrate and menopausal gonadotropins) were the causative factors of this rare obstetric complication.
Overexpression of vasopressin (V3) and corticotrophin‐releasing hormone receptor genes in corticotroph tumours
Authors: De Keyzer Y. , René P. , Beldjord C. , Lenne F. , Bertagna X. 
Published: April 2004

OBJECTIVEThe molecular mechanisms underlying ACTH‐secreting tumour formation remain unknown. Transmembrane signalling pathways play an important role in several endocrine disorders including pituitary tumours. To investigate the role of the pituitary vasopressin (V3) receptor (R) in ACTH‐secreting tumours we have qualitatively and quantitatively analysed its mRNA.DESIGNRT–PCR, denaturing gradient gel electrophoresis and S1 nuclease protection experiments were used to analyse V3 mRNA structure in ACTH‐secreting tumours. We also developed a competitive RT–PCR system to compare the levels of expression of POMC, V3 and CRH‐R genes. This system used as competitor a single mutant template (termed multi‐mutant) containing primers for the three genes flanking an unrelated core sequence allowing multiple quantifications from the same cDNA preparations. We analysed 12 normal pituitaries, 15 corticotroph pituitary adenomas and 6 ACTH‐secreting bronchial carcinoids.RESULTSThe V3 mRNA structure and sequence were found to be identical in normal and tumoural pituitary indicating that the tumoural Vs mRNA codes for a normal receptor. POMC RT–PCR signals in the pituitary tumour group were approximately 7‐fold higher than in the normal pituitary group. Similarly, V3 and CRH‐R signal were increased in pituitary tumors (mean ± SEM: 5.87 × 10−6 ± 1.73 × 10−6, and 2.33 × 10−4 ± 1.4 × 10−4, respectively), when compared to normal pituitaries (1.19 × 10−7 ± 2.39 × 10−8, and 1.7 × 10−6 ± 4.65 × 10−7, respectively) suggesting that these two genes are expressed at very high levels in corticotroph tumours. When expressed relative to the corresponding POMC signals, increases in V3 and CRH‐R signals reached 49‐fold and 137‐fold, respectively, in pituitary tumours. In ACTH‐secreting bronchial carcinoids V3 gene expression level was also higher than in normal pituitary, whereas CRH‐R signals were detected in only 4 of the 6 tumours with wide variations.CONCLUSIONOur results show that both vasopressin and CRH receptor genes are overexpressed in ACTH‐secreting pituitary tumours. They suggest that overexpression of G protein‐coupled receptors may be an additional mechanism through which membrane receptors may play a role in human tumours.
Therapieoptionen der Psoriasis im Kindes‐ und Jugendalter
Authors: Zappel Kristina , Sterry Wolfram , Blume‐Peytavi Ulrike 
Published: April 2004

ZusammenfassungDer Zeitpunkt der Erstmanifestation einer Psoriasis liegt bei etwa 30 % aller Psoriatiker im Kindes‐ und Jugendalter. Bei ¼ dieser Kinder zeigen sich psoriasiforme Hautveränderungen sogar schon um das 2. Lebensjahr. Die Behandlung der kindlichen Psoriasis unterscheidet sich in einigen Punkten wesentlich von der Psoriasistherapie im Erwachsenenalter, da nicht nur Lebensalter und Ausprägungsgrad, sondern auch Entwicklungszustand, prognostische Kriterien und soziales Umfeld berücksichtigt werden sollten. Richtlinien, qualitativ hochwertige Studien und konkrete Empfehlungen zur Therapieauswahl fehlen für die kindliche Psoriasis jedoch meistenteils.Dieser Artikel soll einen Überblick über das therapeutische Management der Psoriasis im Kindes‐ und Jugendalter geben. Wir diskutieren nach aktueller Literatur umfassend externe und interne Therapieoptionen unter kritischer Wertung und Berücksichtigung des Aspektes der Prävention und Verbesserung der Lebensqualität.
Elementanalytische Untersuchungen von Tätowierungsfarbstoffen – Besteht eine potentielle Gefährdung durch Tätowierungsfarbstoffe?
Authors: Schmitz I. , Müller K.‐M. 
Published: April 2004

Zusammenfassung Hintergrund: Auch heute verwendete, im Rahmen der Tätowierung kutan inkorporierte Farbstoffe können Fremdkörperreaktionen auslösen. Methodik: Da es für die Zusammensetzung der Inhaltsstoffe von Tattoofarben noch keine Richtlinien gibt, untersuchten wir in Tätowierungs‐Studios verwendete „neuere” Tattoofarbstoffe auf ihre Elementzusammensetzung, um Hinweise auf eine potentielle Gefährdung durch diese zu finden. Die elementanalytische Charakterisierung erfolgte im Rasterelektronenmikroskop mittels der energiedispersiven Röntgenmikroanalyse. Diese EDS‐Analyse weist Elemente ab der Natriumlinie nach und dient vor allem zum Beleg von Metallkomponenten; über chemische Bindungsverhältnisse können keine Aussagen getroffen werden. Ergebnisse: Unsere Untersuchungen zeigten, daß auch in heute verwendeten Tattoofarbstoffen vielfach Metallkomponenten nachweisbar sind, die als Ursachen persistierender Fremdkörperreaktion bekannt sind. Silizium, Aluminium, Titan und Kupfer fanden sich insbesondere in gelben, grünen und roten Farbstoffen einzelner Chargen. Die Zusammensetzung von Tattoofarben mit gleichen Farbtönen war in verschiedenen Chargen oft divergierend. Schlußfolgerungen: Auch die heute verwendeten „neueren” Tattoofarbstoffe sind nicht als „gewebe‐inert” zu werten und potentielle Ursachen von Fremdkörperreaktionen, die sich noch Jahre nach ihrer Inkorporation einstellen können.
Degree performance of Economics students in UK universities: absolute and relative performance in prior qualifications
Authors: Naylor Robin , Smith Jeremy 
Published: April 2004

AbstractWe exploit individual‐level data on full cohorts of UK university leavers who were enrolled for an Economics degree during the period 1984–85 to 1992–93 or the academic year 1997–98. We analyse the determinants of degree performance and find that performance depends not only on prior qualifications as measured by A‐level scores, for example, but also on the individual student's ranking (based on their A‐level scores) within their cohort at their university. The students' performance is also enhanced by having previously studied mathematics, although there is no benefit from the prior study of Economics. We find that attendance at an Independent school has a negative effect on degree performance, and that there are comparatively few social class background effects. Females are more likely than males to obtain a good degree.
Are Higher Education Subsidies Second Best?
Authors: Wigger Berthold U. 
Published: April 2004

AbstractAn optimal taxation framework is considered in which part of the population can take advantage of investment in higher education. It is shown that social welfare can sometimes be increased by supplementing linear income taxes with a subsidy to material investment in higher education, but that social welfare can never be increased by supplementing a non‐linear income tax with such a subsidy.
The Taxation of Financial Capital under Asymmetric Information and the Tax‐competition Paradox
Authors: Eggert Wolfgang , Kolmar Martin 
Published: April 2004

AbstractInformation sharing between governments is examined in an optimal‐taxation framework. We introduce a taxonomy of alternative systems of international capital‐income taxation and characterize the choice of tax rates and information exchange. The model reproduces the conclusion found in earlier literature that integration of international caopital markets may lead to the under‐provision of publicly provided goods. However, in contrast to previous results in the literature, under‐provision occurs due to inefficiently coordinated expectations. We show that there exists a second equilibrium with an efficient level of public‐good provision as well as complete and voluntary information exchange between national tax authorities.
Dental pulp cells provide neurotrophic support for dopaminergic neurons and differentiate into neurons in vitro; implications for tissue engineering and repair in the nervous system
Authors: Nosrat Irina V. , Smith Christopher A. , Mullally Patrick , Olson Lars , Nosrat Christopher A. 
Published: April 2004

AbstractGlial cell line‐derived neurotrophic factor (GDNF) mRNA is highly expressed by dental pulp cells (DPCs) prior to the initiation of dental pulp innervation. We show that radioactively labelled exogenous GDNF is retrogradely transported from neonatal teeth and vibrissae to the trigeminal neurons, indicating that GDNF acts as a classical neurotrophic factor in the trigeminal system. We also show that DPCs from both rats and humans produce nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF) and GDNF mRNAs in vitro, promote the survival and phenotypic characteristics of embryonic dopaminergic (DA) neurons and protect DA neurons against the neurotoxin 6‐hydroxy‐dopamine (6‐OHDA) in vitro. By using inhibitory antibodies to NGF, BDNF and GDNF, we show that the promotion of DA neuron survival relates to the production and release of neurotrophic proteins by DPCs in vitro. We suggest that in vivo production of neurotrophic factors by DPCs play roles in tooth innervation. However, continued production of neurotrophic factors by the DPCs might have wider implications. We propose that the dental pulp is a viable source of easily attainable cells with possible potential for development of autologous cell transplantation therapies. We also show that a population of neural crest‐derived dental pulp cells acquire clear neuronal morphology and protein expression profile in vitro, indicating the presence of a cell population in the dental pulp with neuronal differentiation capacity that might provide additional benefits when grafted into the CNS.
Locus coeruleus activation shortens synaptic drive while decreasing spike latency and jitter in sensorimotor cortex. Implications for neuronal integration
Authors: Lecas Jean‐Claude 
Published: April 2004

AbstractChronic recording of locus coeruleus (LC) neurons in rat and monkey have pointed out that brief, phasic LC discharges, but not sustained activity, are specifically related to salient stimuli and attention. However, the sensory consequences of phasic activation of the noradrenergic system by a brief conditioning stimulation of the LC have not been fully investigated. This study examined the effect of LC activation on synaptic and neuronal responses to a tactile stimulus in the sensorimotor cortex of the anaesthetized rat, by analysing the fine temporal structure of sensory discharges and current source‐density profiles recorded from the same electrodes. LC stimulation, with minimal EEG effects, consistently reduced the synaptic input in layers IV and V–VI, by decreasing the amplitude and duration of short‐latency current sinks, but not the slope of their early rising phase. Simultaneously, most multiple and single unit excitatory responses were shortened by the suppression of their late component after 25–30 ms, whereas robust temporal facilitation of the early discharge was found for spike latency mean and variance, spike timing and synchronization to the stimulus, but leaving the number of spikes unaffected. These two apparently opposite effects on the synaptic drive and neuronal response are reminiscent of the noradrenergic depression of afferent synaptic potentials observed with an increased neuronal excitability in vitro. They are interpreted as a noradrenergic sharpening of thalamocortical processing consistent with a presumed role of synchronous discharges in perception that would depend on activated states, particularly when LC activity is correlated with vigilance or attention.
Ligand‐gated channels in early mesencephalic neuronal precursors: immunocytochemical and electrophysiological analysis
Authors: Schlesinger F. , Meywirth J. , Krampfl K. , Grosskreutz J. , Petri S. , Mauth C. , Just L. , Bader A. , Bufler J. 
Published: April 2004

AbstractNeuronal precursors play an important role in potential regenerative therapeutic strategies in different neurodegenerative diseases, e.g. Parkinson's disease. To understand proliferation and differentiation of these cells in vitro and in vivo, it is important to characterize functional properties of neuronal precursors in detail. The aim of the present study was to analyse the electrophysiological characteristics of ligand‐gated channels of neuronal precursors prepared from the rat ventral mesencephalon (VM) of embryonic stage 12.5 during their in vitro differentiation. For the experiments we used the patch‐clamp technique in combination with a system for ultrafast solution exchange and immunocytochemistry. It could be shown that functional active AMPA‐type glutamate as well as GABAA receptor channels are expressed at an early stage of neuronal development. In culture we observed excitatory as well as inhibitory postsynaptic currents (defined by their different kinetics) which correspond to the activation of AMPAergic and GABAergic receptor channels. Two populations of glutamate‐activated currents could be differentiated by their different time course of desensitization whereas the time course of resensitization and deactivation was normally distributed in all cells. GABAergic currents could be blocked by bicuculline and their kinetics correspond to that of GABAA receptor channel currents. Summarizing the results, in the present study it was shown for the first time that neuronal embryonic precursors of the rat VM express both functional AMPA‐type glutamate and functional GABAA receptor channels in vitro.
Left hemisphere motor facilitation in response to manual action sounds
Authors: Aziz‐Zadeh Lisa , Iacoboni Marco , Zaidel Eran , Wilson Stephen , Mazziotta John 
Published: April 2004

AbstractPrevious studies indicate that the motor areas of both hemispheres are active when observing actions. Here we explored how the motor areas of each hemisphere respond to the sounds associated with actions. We used transcranial magnetic stimulation (TMS) to measure motor corticospinal excitability of hand muscles while listening to sounds. Sounds associated with bimanual actions produced greater motor corticospinal excitability than sounds associated with leg movements or control sounds. This facilitation was exclusively lateralized to the left hemisphere, the dominant hemisphere for language. These results are consistent with the hypothesis that action coding may be a precursor of language.
Plasticity of somatostatin and somatostatin sst2A receptors in the rat dentate gyrus during kindling epileptogenesis
Authors: Csaba Zsolt , Richichi Cristina , Bernard Véronique , Epelbaum Jacques , Vezzani Annamaria , Dournaud Pascal 
Published: April 2004

AbstractIncreasing evidence suggests that somatostatin may control neuronal excitability during epileptogenesis. In the hippocampus, sst2A receptors are likely to mediate somatostatin inhibitory actions but little is known about their status in kindled tissues. In the present study, sst2A receptor and somatostatin immunoreactivity were examined by confocal microscopy in the hippocampus during and after kindling acquisition. In control rats, somatostatin‐positive axon terminals were mainly found in the stratum lacunosum moleculare of CA1 area and in the outer molecular layer of the dentate gyrus. sst2A receptor immunoreactivity was diffusely distributed in the strata radiatum and oriens of CA1 and in the stratum moleculare of the dentate gyrus. Immunogold electron microscopy revealed that sst2A receptors were predominantly localized postsynaptically, at the plasma membrane of dendritic shafts and spines of principal neurons. During kindling epileptogenesis, qualitative and semiquantitative analysis revealed a progressive decrease of sst2A immunoreactivity in the outer molecular layer, which was spatially associated with an increase in somatostatin immunoreactivity. No obvious changes in sst2A receptor immunoreactivity were observed in other hippocampal subfields. These results suggest that the decrease of sst2A receptor immunoreactivity in the outer molecular layer reflects receptor down‐regulation in distal dendrites of granule cells in response to chronic somatostatin release. Because the sst2A receptor appears to mediate anticonvulsant and antiepileptogenic effects of somatostatin, this may represent a pivotal mechanism contributing to epileptogenesis.