bluuebunny/crossref_metadata_2025 huggingface dataset:
Significance of Sharp Waves in Routine EEGs After Epilepsy Surgery
Authors: Godoy Jaime , Lüders H. , Dinner D. S. , Morris H. H. , Wyllie E. , Murphy D.
Published: August 2005

Summary: We retrospectively analyzed the presence of sharp waves in 2‐h EEGs performed 6 months after epilepsy surgery in 59 patients. To study the significance of the postoperative interictal epileptiform activity in the tissue remaining after resection, we included only patients with a single epileptic focus (as defined preoperatively by prolonged video/EEG recordings and subdural electrode arrays studies) and no progressive structural lesions. Temporal lobectomy was performed in 51 patients (86%); extratemporal resections were performed in the remainder. The epileptogenic focus was completely resected in 26 patients (44%). The immediate postoperative electro‐corticograms (EcoG) showed spikes in 13 patients (22%). At 6‐month follow‐up, 43 patients (73%) were seizure‐free or had auras only and 12 patients (20%) had epileptiform activity on EEG. A significant correlation was noted between presence of sharp waves in the 6‐month postoperative EEG and recurrence of seizures (Fisher's exact test p = 0.011) and also with the extent of the resection (complete vs. incomplete p = 0.042). We noted no correlation between postoperative epileptiform activity and location of the resection (temporal vs. extratemporal), presence of spikes in immediate postoperative EcoG, or occurrence of auras only at 6‐month follow‐up.
Magnetic Resonance Imaging in Infantile Spasms: Effects of Hormonal Therapy
Authors: Konishi Yukuo , Yasujima Miki , Kuriyama Masonori , Konishi Kaoru , Hayakawa Katsumi , Fuji Yasushi , Ishii Yasushi , Sudo Masakatsu
Published: August 2005

Summary: Magnetic resonance imaging (MRI) was per‐formed on five patients with infantile spasms who were treated with relatively low doses of adrenocorticotrophic hormone (ACTH) to study the extent of brain shrinkage induced by ACTH therapy. MRI prior to ACTH therapy revealed periventricular hyperintensity (PVH) areas and poor myelination in four patients. In one case, MRI per‐formed 2 days after initiation of ACTH therapy also showed PVH and poor myelination. Brain shrinkage was observed 2 weeks after initiation of ACTH therapy. The most impressive follow‐up finding upon MRI was the de‐crease in PVH found in four patients. The differentiation between myelinated white matter and surrounding cortex became poorer in three cases. Cortical atrophy progressed in all patients but ventricular dilation progressed in only one patient. At the end of ACTH therapy, ventricular dilation progressed in all cases. These findings suggest that loss of water not only from periventricular white matter but also from cortex is the main etiological factor of brain shrinkage induced by ACTH.
The Sudden Unexplained Death Syndrome in Epilepsy: Demographic, Clinical, and Postmortem Features
Authors: Earnest Michael P. , Thomas George E. , Eden Randall A. , Hossack Kenneth F.
Published: August 2005

Summary:Sudden unexplained death syndrome (SUDS) accounts for about 10% of deaths in patients with epilepsy. It is associated with subtherapeutic postmortem serum antiepileptic drug (AED) levels but no anatomic cause of death on autopsy. The mechanisms of death are not known. We investigated 44 cases of SUDS for details of seizure history, treatment, medical and psychological history, events at the time of death, and postmortem findings. Cases of status epilepticus, drowning or other identifiable causes of death were excluded. Two groups emerged: five children with uncontrolled seizures receiving multiple AEDs and good compliance with medications, and 39 adults with less frequent seizures, often receiving monotherapy, but noncompliant with medications. Four children (80%) but only one adult (3%) had fully therapeutic postmortem AED levels. Sixty‐three percent of adults recently had experienced an unusually stressful life event. Investigation of the circumstances at the time of death suggested two possible modes of death: (a) a seizure with an immediately fatal arrhythmia, or, (b) a seizure, recovery, then delayed secondary respiratory arrest or arrhythmia. Even though the mechanisms of death are unknown, the risk of SUDS may be reduced by encouraging patients to be compliant with medications, especially in times of unusual life stress.
Neuropsychological Abilities Before and After 5 Years of Stable Antiepileptic Drug Therapy
Authors: Dodrill Carl B. , Wilensky Alan J.
Published: August 2005

Summary: Detailed neuropsychological evaluations were conducted on 198 adults with epilepsy before and after a 5‐year study period. Of these, three groups of 11 persons each were formed in which the patients did not change their medication: (a) phenytoin (PHT) monotherapy; (b) PHT and other drug(s); (c) drug regimens exclusive of PHT. The typical patient had few seizures during the study period. Examination of data from 20 neuropsychological and intellectual variables obtained at the beginning and end of the 5‐year study period revealed few statistically significant changes in mental abilities and no losses. Thus, we were unable to find evidence for insidious cognitive losses with PHT and other drugs over time with normal therapeutic serum levels and in the absence of active seizure disorders.
Intrarectal Diazepam in Epileptic Adults
Authors: Remy C. , Jourdil N. , Villemain D. , Favel P. , Genton P.
Published: August 2005

Summary:Intrarectally (i.r.) administered diazepam (DZP) solution at doses of 20 and 30 mg in the treatment of serial seizures was studied in 39 adult patients with refractory partial epilepsy. Patients were randomly distributed into two groups (20 mg, n = 21; 30 mg, n = 18). Plasma levels of DZP were assessed over 24 h following i.r. injection. The efficacy of i.r. DZP in the treatment of serial seizures in adults was confirmed; onset of effect was noted ∼10 min after the injection, and the effective dose was 0.50 mg/kg. Tolerance and acceptability were good. Intrarectal injection of DZP can be performed even by unskilled personnel and may be recommended in patients with serial seizures in the hope of preventing development of status epilepticus.
Effects of Ketamine Anesthesia on Phenytoin Biodisposition
Authors: Sechi GianPietro , Caria Marcello A. , Melis Francesco , Tanca Salvatore , Canu Maria , Deserra Francesca , Rosati Giulio
Published: August 2005

Summary: After oral administration (10% suspension in arabic gum, at 500 mg/kg), total phenytoin (PHT) concentrations were measured in the blood and brain of rats anesthetized with ketamine (60 mg/kg, intraperitoneally i.p.) and in a control group that received only PHT. The concentration of PHT in blood and brain was significantly higher in the ketamine than in the control group. At 1,1.5, 2, and 3 h, increased brain PHT reflected increased blood concentrations. At all times, the plasma protein binding of PHT was similar in both groups. After intravenous (i.v.) administration, instead, at 10 mg/kg, total PHT concentrations were similar in rats anesthetized with ketamine (60 mglkg, i.p.) and in a control group that received only PHT under mild ether anesthesia. Thus, the main factor involved with the altered PHT biodisposition caused by ketamine anesthesia appears to be increased absorption of the drug.
Phenytoin‐Folate Interactions: Differing Effects of the Sodium Salt and the Free Acid of Phenytoin
Authors: Carl G. F. , Smith M. L.
Published: August 2005

Summary: Chronic phenytoin (PHT) treatment has long been associated with folate deficiency. It has been suggested that pH changes in the gut associated with PHT ingestion may be responsible for decreased folate uptake either by direct inhibition of folate transport into the intestinal mucosa or by inhibition of folate conjugase activity. To examine these possibilities, rats were gavaged chronically with PHT using either the sodium salt (NaPHT) or the free acid (HPHT) in the presence of folk acid as the dietary source of folate. The NaPHT caused a greater depletion of folate in the liver and brain and a significant increase in methylenetetrahydrofolate reductase activity in the liver. The HPHT caused a significantly decreased weight gain over the 8 weeks of treatment and resulted in a much higher liver PHT concentration and a slightly lower plasma PHT concentration. These data support the hypothesis that PHT‐induced changes in pH in the gut affect the enterohepatic circulation of folate.
Alterations of Ballistic Movements in Epileptic Patients with Phenytoin Intoxication
Authors: Benvenuti F. , Bandinelli S. , Mencarelli M. A. , Lunardelli M. L. , Campostrini R. , Zaccara G. , Pantaleo T.
Published: August 2005

Summary: We assessed the effects of phenytoin (PHT) overdosage on ballistic arm abduction movements in nine epileptic patients receiving long‐term PHT treatment. During the overdosage period, all but one showed clinical abnormalities referable to impaired cerebellar function; one also had slowness of movement. Ballistic movements showed abnormalities in all of the patients although a great variability was present in the type and severity of abnormalities. In four patients, kinematic and EMG recordings differed least from the normal, in four they resembled those described in patients with cerebellar deficits, and in one those described in patients with Parkinson disease. The type and severity of clinical disturbances of voluntary motor control as well as alterations of ballistic movements were not related to specific PHT plasma concentrations. One month after the adjustment of PHT dosage, the patients who had clinical abnormalities completely recovered or markedly improved. Previously observed kinematic and EMG abnormalities completely disappeared or improved markedly.
Hierarchy of Seizure States in the Electrogenic Limbic Status Epilepticus Model: Behavioral and Electrographic Observations of Initial States and Temporal Progression
Authors: Handforth Adrian , Ackermann Robert F.
Published: August 2005

Summary: Repeated electrical stimulation was delivered to the amygdala in a paradigm of electrogenic limbic status epilepticus induction in rats. We observed four distinct initial behavioral states associated with prolonged spiking, comprising an ordered hierarchy of severity: immobile, exploratory, minor convulsive, and clonic convulsive. The EEG and behavioral topography of the initial prolonged seizure state behaviorally and electrographically resembled the acute seizures that occurred earlier during induction. Onset of status epilepticus on limbic induction appears to represent not a new type of seizure activity, but instead the extended version of repeated brief limbic‐onset seizures as seizure‐terminating mechanisms gradually become ineffective. These prolonged seizure states can therefore be used to study the anatomy and mechanisms of brief limbic seizures. We also examined the temporal progression of amygdala‐induced prolonged‐seizure states. At one end of the severity spectrum, immobile‐associated spiking was prone to terminate early, within 90 min, accompanied by normalization of behavior. At the other end of the spectrum, clonic convulsive status epilepticus slowly decreased in behavioral severity together with a change in EEG from fast to slow spiking. Exploratory status epilepticus was characterized by incessant explorationlike behavior that could last hours and was associated with slow periodic spikecomplexes on EEG. The long‐term course consisted either of slow devolution, with eventual cessation of spiking, or of spontaneous late ascension to convulsive status. Prolonged‐seizure states may thus be considered to fall not only within an anatomiclbehavioral hierarchy of severity, but also within a temporal physiologic progression.
In Vitro Quantitative Autoradiography of [3H]‐L‐Deprenyl and [3H]‐PK 11195 Binding Sites in Human Epileptic Hippocampus
Authors: Kumlien Eva , Hilton‐Brown Per , Spännare Bo , Gillberg Per‐Göran
Published: August 2005

Summary: Distribution of the enzyme monoamine oxidase B (MAO‐B) and the peripheral benzodiazepine binding site (ψ3 site) was studied by quantitative autoradiography using [3H]L‐deprenyl and [3H]PK 11195, two tentative glial markers, as ligands. Sclerotic hippocampus from seven patients who had had anterotemporal lobe resection because of intractable complex partial epilepsy were investigated and compared with postmortem hippocampus from three nonepileptic controls. A significantly higher degree of L‐deprenyl and PK 11195 binding was observed in the epileptic cases. The increased binding of both ligands correlated to extent of neuronal loss, but only PK 11195 showed correlation to degree of gliosis. We conclude that both ligands could provide useful markers for quantitating the degree of gliosis in pathologic states such as epilepsy. They may be applicable in future in vivo studies with positron emission tomography (PET).
Increased pH and Seizure Foci Inorganic Phosphate in Temporal Demonstrated by [31P]MRS
Authors: Laxer Kenneth D. , Hubesch Bruno , Sappey‐Marinier Dominique , Weiner Michael W.
Published: August 2005

Summary: To investigate alterations of brain metabolism associated with temporal lobe epilepsy, [31P]MRS studies were performed on the anterotemporal lobes of patients with medically refractory complex partial seizures. Interictally, the pH was significantly more alkaline in the temporal lobe ipsilateral to the seizure focus (7.25 vs. 7.08, p < 0.05), and the inorganic phosphorous concentration was greater on the side of the epileptogenic focus (1.9 vs. 1. 1 mM, p < 0.05). These changes in pH and inorganic phosphate may represent metabolic alterations secondary to seizures. Alternatively, because alkalosis enhances neural excitability and may enhance seizure activity, the increased pH of the seizure focus may provide insight into the pathophysiologic mechanism of epileptic seizures.
Long‐Term Follow‐Up of Stereotactic Lesionectomy in Partial Epilepsy: Predictive Factors and Electroencephalographic Results
Authors: Cascino Gregory D. , Kelly Patrick J. , Sharbrough Frank W. , Hulihan Joseph F. , Hirschorn Kathryn A. , Trenerry Max R.
Published: August 2005

Summary: We performed an extended follow‐up study assessing the efficacy of stereotactic lesionectomy in 23 patients with foreign‐tissue lesions and intractable partial epilepsy. Sixteen lesions involved functional or eloquent cortex as determined by anatomic localization. By definition, the surgical objective in these patients was excision of the lesion, and not the surrounding cerebral cortex. The mean duration of follow‐up was 48.5 months (range 26–69 months). Seventeen patients (74%) had a significant reduction in seizures (90%) after lesionectomy. Thirteen patients (56%) had a class I operative out‐come (seizure‐free, single seizure episode, or auras only). Five of these patients were successfully discontinued from antiepileptic drug (AED) therapy. Patients with temporal lobe lesions were statistically less likely to be rendered seizure‐free (p < 0.05). Age at operation, duration of epilepsy, and underlying pathology were not significant predictors of seizure outcome. The anatomic distribution of extracranial EEG recorded epileptiform activity did not appear to be an important determinant of outcome. The absence of interictal epileptiform activity in the 3‐month postoperative EEG correlated with a significant reduction in seizures. Long‐term follow‐up indicates that lesionectomy may be effective in select patients with medically refractory partial seizure disorders.
Controlled Examination of Effects of Progressive Relaxation Training on Seizure Reduction
Authors: Puskarich Cathryn A. , Whitman Steven , Dell Jade , Hughes John R. , Rosen Alexander J. , Hermann Bruce P.
Published: August 2005

Summary: We determined the efficacy of progressive muscle relaxation in reducing seizure frequency. Subjects were 24 people with epilepsy attending an urban neurology clinic. The experimental design consisted of an 8‐week baseline period, a treatment period of six sessions of progressive relaxation training (PRT, n = 13) or quiet sitting (QS, n = 11) and an 8‐week follow up. In the PRT group, 11 subjects reported a decrease in seizure frequency (p < 0.01), and in the QS group, 7 reported a decrease (p > 0.05). The mean decrease in seizure frequency was 29% for the PRT group (p < 0.01) but only 3% for the QS group (p > 0.05). This is the fifth recent report of a controlled study documenting the success of progressive relaxation therapy in seizure reduction. PRT is inexpensive and noninvasive and facilitates patient participation. Such a technique should be incorporated into clinical practice.
Relation of Plasma and Brain Concentrations of the Anticonvulsant Ameltolide to Its Pharmacologic Effects
Authors: Leander J. David , Parli C. John , Potts Brian , Lodge David
Published: August 2005

Summary: Ameltolide, a newly described anticonvulsant, was studied to determine the relation between dose administered, plasma and brain concentrations, and pharmacologic effects. The relation of the N‐acetyl metabolite and the OH‐N‐acetyl metabolite to the dose administered and to the pharmacologic effects was also determined. Ameltolide plasma concentrations in both mice and rats were linearly related to dose administered over the entire dose range from low doses, at which the anticonvulsant effects were noted, to high doses, at which neurologic impairment occurred. The plasma concentrations of the metabolites were not as consistently linearly dose‐related in the two species. In rats, the brain concentrations of ameltolide were highly correlated with plasma concentrations and the doses administered. Ameltolide was shown to have a phenytoin (PHT)‐like anticonvulsant profile in vitro in the cortical slice preparation. These data confirm the potent anticonvulsant profile of ameltolide and the lack of significant activity of the metabolites. Key Words: Ameltolide‐Anticonvulsants‐Plasma‐Brain‐Mice‐Rats‐Pharmacology.
Phenytoin Pharmacokinetics: Before and After Folic Acid Administration
Authors: Berg Mary J. , Fincham Richard W. , Ebert Barbara E. , Schottelius Dorothy D.
Published: August 2005

Summary: Phenytoin (PHT) exhibits linear and Michaelis‐Menten pharmacokinetics. PHT decreases serum folate; the vitamin folk acid (FA) is hypothesized to be a cofactor in the metabolism of PHT. The depletion of serum folate may explain the unpredictability of measured total serum PHT concentrations and time to steady state as compared with the Michaelis‐Menten predictive calculations. We examined PHT pharmacokinetics before and after FA supplementation in 13 healthy male volunteers. The study was divided into two phases. Phase 1 determined Vmax (mg/day) and Km (μg/ml) of PHT to calculate PHT doses needed for the second phase. Phase 11 was a four‐way cross‐over study to examine the effect of 1 and 5 mg FA on total serum PHT concentrations 1 μg/ml less and 5 μg/ml greater than the subject's Km, K−1, and Km+5, respectively. Predicted versus measured total serum PHT concentrations, t90% (days to steady state), and the effect of FA were calculated for Km−1, and Km+5 before and after 1 or 5 mg FA. The measured total serum PHT concentration was always greater than the calculated concentration (p < 0.05), and t90% was always longer than the calculated t90% (p < 0.05) for Km−1, before FA (all subjects decreased serum FA); the same was observed for Km+5. If folate is assumed to be a cofactor in PHT metabolism, these results are expected, because depletion of the vitamin would indicate less folate to drive the metabolism of PHT, resulting in higher total serum PHT concentrations and longer time to reach steady state. Even though steady‐state criterion was satisfied, “pseudo‐steady state” could have occurred, making the time to steady state longer and possibly increasing total serum PHT further. When FA was added, the same results were obtained. Neither was there any difference in total serum PHT concentration before and after either 1 or 5 mg FA. These latter results may be explained by the fact that depletion of FA had to be corrected first before the role of FA as a cofactor in PHT metabolism could be used. Therefore, the interdependence of PHT and FA may explain the pseudo‐steady state observed for PHT and the deviations from the Michaelis‐Menten predictive calculations. Perhaps FA supplementation should be recommended when PHT therapy is initiated.
Effects of Valproate in a Model Nervous System (Buccal Ganglia of Helix Pomatia): I. Antiepileptic Actions
Authors: Altrup U. , Gerlach G. , Reith H. , Said M. N. , Speckmann E.‐J.
Published: August 2005

Summary:Cellular actions of valproate (VPA) were studied using intracellular recordings of identified neuronal individuals in the buccal ganglia ofHelix pomatia.Under nonepileptic conditions, VPA induced (a) a hyperpolarization, (b) slight changes in action potentials (AP), and (c) an increase in membrane resistance. Under epileptic conditions (i.e., during application of an epileptogenic drug), extracellular application of VPA decreased frequency of occurrence of epileptic depolarizations (early effect) and led to a decay in paroxysmal depolarizations (late effect). Intracellular injection of VPA could block epileptic activity in the treated neuron immediately. A metabolite of VPA (trans‐2‐en VPA) mainly lacked the late effect (decay in epileptic depolarizations) obtained with VPA. Results suggest that the early antiepileptic effect is exerted from the extracellular side of the neuronal membrane and that the late effect results from intracellular actions of VPA being delayed by slow access to an intracellular site.
Effects of Valproate in a Model Nervous System (Buccal Ganglia of Helix Pomatia): II. Epileptogenic Actions
Authors: Altrup U. , Reith H. , Speckmann E.‐J.
Published: August 2005

Summary: High concentrations of valproate (VPA; ≥20 nM) depolarized identified neuronal individuals in the buccal ganglia of Hetix pomutia and transiently induced paroxysmal depolarization shifts (PDS). Threshold concentration of VPA for the induction of PDS was decreased (a) by increased seizure susceptibility, (b) by increased concentrations of derivatives of VPA, and (c) by increased H + concentrations. Intrasomatic injection of VPA did not induce PDS. The epileptogenic action of VPA is believed to be exerted from the extracellular side of the cell membrane.
The Limits of Financial Globalization
Authors: STULZ RENÉ M.
Published: August 2005

Despite the dramatic reduction in explicit barriers to international investment activity over the last 60 years, the impact of financial globalization has been surprisingly limited. I argue that country attributes are still critical to financial decision‐making because of “twin agency problems” that arise because rulers of sovereign states and corporate insiders pursue their own interests at the expense of outside investors. When these twin agency problems are significant, diffuse ownership is inefficient and corporate insiders must co‐invest with other investors, retaining substantial equity. The resulting ownership concentration limits economic growth, financial development, and the ability of a country to take advantage of financial globalization.
Time Variation in the Covariance between Stock Returns and Consumption Growth
Authors: DUFFEE GREGORY R.
Published: August 2005

The conditional covariance between aggregate stock returns and aggregate consumption growth varies substantially over time. When stock market wealth is high relative to consumption, both the conditional covariance and correlation are high. This pattern is consistent with the “composition effect,” where agents' consumption growth is more closely tied to stock returns when stock wealth is a larger share of total wealth. This variation can be used to test asset‐pricing models in which the price of consumption risk varies. After accounting for variations in this price, the relation between expected excess stock returns and the conditional covariance is negative.
Rational IPO Waves
Authors: PÁSTOR ĽUBOŠ , VERONESI PIETRO
Published: August 2005

We argue that the number of firms going public changes over time in response to time variation in market conditions. We develop a model of optimal initial public offering (IPO) timing in which IPO waves are caused by declines in expected market return, increases in expected aggregate profitability, or increases in prior uncertainty about the average future profitability of IPOs. We test and find support for the model's empirical predictions. For example, we find that IPO waves tend to be preceded by high market returns and followed by low market returns.
Does Prospect Theory Explain IPO Market Behavior?
Authors: LJUNGQVIST ALEXANDER , WILHELM WILLIAM J.
Published: August 2005

We derive a behavioral measure of the IPO decision‐maker's satisfaction with the underwriter's performance based on Loughran and Ritter (2002) and assess its ability to explain the decision‐maker's choice among underwriters in subsequent securities offerings. Controlling for other known factors, IPO firms are less likely to switch underwriters when our behavioral measure indicates they were satisfied with the IPO underwriter's performance. Underwriters also extract higher fees for subsequent transactions involving satisfied decision‐makers. Although our tests suggest that the behavioral model has explanatory power, they do not speak directly to whether deviations from expected utility maximization determine patterns in IPO initial returns.
Predatory Trading
Authors: BRUNNERMEIER MARKUS K. , PEDERSEN LASSE HEJE
Published: August 2005

This paper studies predatory trading, trading that induces and/or exploits the need of other investors to reduce their positions. We show that if one trader needs to sell, others also sell and subsequently buy back the asset. This leads to price overshooting and a reduced liquidation value for the distressed trader. Hence, the market is illiquid when liquidity is most needed. Further, a trader profits from triggering another trader's crisis, and the crisis can spill over across traders and across markets.
Strategic Behavior and Underpricing in Uniform Price Auctions: Evidence from Finnish Treasury Auctions
Authors: KELOHARJU MATTI , NYBORG KJELL G. , RYDQVIST KRISTIAN
Published: August 2005

We contribute to the debate on the optimal design of multiunit auctions by developing and testing robust implications of the leading theory of uniform price auctions on the bid distributions submitted by individual bidders. The theory, which emphasizes market power, has little support in a data set of Finnish Treasury auctions. A reason may be that the Treasury acts strategically by determining supply after observing bids, apparently treating the auctions as a repeated game between itself and primary dealers. Bidder behavior and underpricing react to the volatility of bond returns in a way that suggests bidders adjust for the winner's curse.
Market Timing and Managerial Portfolio Decisions
Authors: JENTER DIRK
Published: August 2005

This paper provides evidence that top managers have contrarian views on firm value. Managers' perceptions of fundamental value diverge systematically from market valuations, and perceived mispricing seems an important determinant of managers' decision making. Insider trading patterns shows that low valuation firms are regarded as undervalued by their own managers relative to high valuation firms. This finding is robust to controlling for noninformation motivated trading. Further evidence links managers' private portfolio decisions to changes in corporate capital structures, suggesting that managers try to actively time the market both in their private trades and in firm‐level decisions.
Do Insiders Learn from Outsiders? Evidence from Mergers and Acquisitions
Authors: LUO YUANZHI
Published: August 2005

I find that the market reaction to a merger and acquisition (M&A) announcement predicts whether the companies later consummate the deal. The relation cannot be explained by the market's anticipation of the closing decision or its perception of the deal quality at the announcement. Merging companies appear to extract information from the market reaction and later consider it in closing the deal. Furthermore, the relation varies with deal characteristics, suggesting that companies seem to have a higher incentive to learn from the market when canceling the announced deal is easier or when the market has more information that the companies do not know.
The Impact of Bank Consolidation on Commercial Borrower Welfare
Authors: KARCESKI JASON , ONGENA STEVEN , SMITH DAVID C.
Published: August 2005

We estimate the impact of bank merger announcements on borrowers' stock prices for publicly traded Norwegian firms. Borrowers of target banks lose about 0.8% in equity value, while borrowers of acquiring banks earn positive abnormal returns, suggesting that borrower welfare is influenced by a strategic focus favoring acquiring borrowers. Bank mergers lead to higher relationship exit rates among borrowers of target banks. Larger merger‐induced increases in relationship termination rates are associated with less negative abnormal returns, suggesting that firms with low switching costs switch banks, while similar firms with high switching costs are locked into their current relationship.
Practical Aspects in the Management of Vaginal Atrophy and Sexual Dysfunction in Perimenopausal and Postmenopausal Women
Authors: Goldstein Irwin , Alexander Jeanne Leventhal
Published: August 2005

Introduction

The decline in circulating estrogen levels in peri- and postmenopause has a wide range of physiological effects, including atrophy of tissues in the urogenital tract. Vaginal atrophy is an important contributor to postmenopausal sexual dysfunction.

Aim

To provide a framework for clinical evaluation and clinical management of sexual dysfunction secondary to vaginal atrophy.

Method

Conduct a brief overview of literature on evaluation and treatment of vaginal atrophy, augmented with the authors’ clinical observations and experience.

Results

Estrogen decline disrupts many physiological responses characteristic of sexual arousal, including smooth muscle relaxation, vasocongestion, and vaginal lubrication; genital tissues depend on continued estrogen and androgen stimulation for normal function. An upward shift in vaginal pH as the result of vaginal atrophy alters the normal vaginal flora. Reduced lubrication capability and reduced tissue elasticity, in addition to shortening and narrowing of the vaginal vault, can lead to painful and/or unpleasant intercourse. At the same time, diminished sensory response may reduce orgasmic intensity. Other contributors to peri- and postmenopausal sexual dysfunction include reduced androgen levels, aging of multiple body systems, and side-effects of medications. Workup of sexual health problems starts by taking a comprehensive sexual, medical, and psychosocial history, followed by complete physical examination and laboratory evaluation. Clinical management includes measures to preserve and enhance overall health, adjustment of medication regimes to reduce or avoid side-effects, and topical or systemic hormone supplementation with estrogens and/or androgens.

Conclusions

No single therapeutic approach is appropriate for every woman with peri- or postmenopausal sexual dysfunction; instead, treatment should be based on a comprehensive evaluation and consideration of medical and psychosocial contributors to the individual's dysfunction. Further research is required to establish optimal regimens of hormonal and nonhormonal agents, including dosages/dosage forms and duration of treatment, for specific subtypes of sexual dysfunction.
A COMPARISON OF METHODS FOR MONITORING INDIVIDUAL PERFORMANCES IN TASTE SELECTION TESTS
Authors: CALVIÑO AMALIA , GARRIDO DELIA , DRUNDAY FABIÁN , TAMASI OLGA
Published: August 2005

The evaluation of panel performance was made by three methods: average of correct responses (A), comparison of distances of individual standardized judgments to the average standardized responses (D) and a principal components analysis (PCA). Thirty assessors identified water and basic tastes and discriminated different sweet stimuli in neutral or acidified vehicles using R‐index rating and ranking tests. By A and D methods 22 assessors were qualified as proficient. Composition of both panels was identical except for one judge. The output from PCA provided a graphical representation of the performance of the assessors and retained different subsets of 24–26 panelists for different proposals as discrimination of sweetness in acidified beverages, recognition of bitterness, sourness and discrimination of slight sweetness or evaluation of saltiness.
Domain analysis of Kv6.3, an electrically silent channel
Authors: Ottschytsch Natacha , Raes Adam L. , Timmermans Jean‐Pierre , Snyders Dirk J.
Published: August 2005

The subunit Kv6.3 encodes a voltage‐gated potassium channel belonging to the group of electrically silent Kv subunits, i.e. subunits that do not form functional homotetrameric channels. The lack of current, caused by retention in the endoplasmic reticulum (ER), was overcome by coexpression with Kv2.1. To investigate whether a specific section of Kv6.3 was responsible for ER retention, we constructed chimeric subunits between Kv6.3 and Kv2.1, and analysed their subcellular localization and functionality. The results demonstrate that the ER retention of Kv6.3 is not caused by the N‐terminal A and B box (NAB) domain nor the intracellular N‐ or C‐termini, but rather by the S1–S6 core protein. Introduction of individual transmembrane segments of Kv6.3 in Kv2.1 was tolerated, with the exception of S6. Indeed, introduction of the S6 domain of Kv6.3 in Kv2.1 was enough to cause ER retention, which was due to the C‐terminal section of S6. The S4 segment of Kv6.3 could act as a voltage sensor in the Kv2.1 context, albeit with a major hyperpolarizing shift in the voltage dependence of activation and inactivation, apparently caused by the presence of a tyrosine in Kv6.3 instead of a conserved arginine. This study suggests that the silent behaviour of Kv6.3 is largely caused by the C‐terminal part of its sixth transmembrane domain that causes ER retention of the subunit.
Mechanics of Bimaterial Interface: Shear Deformable Split Bilayer Beam Theory and Fracture
Authors: Wang Jialai , Qiao Pizhong
Published: August 2005

A novel split beam model is introduced to account for the local effects at the crack tip of bi-material interface by modeling a bi-layer composite beam as two separate shear deformable beams bonded perfectly along their interface. In comparisons with analytical two-dimensional continuum solutions and finite element analysis, better agreements are achieved for the present model, which is capable of capturing the local deformation at the crack tip in contrast to the conventional composite beam theory. New solutions of two important issues of cracked beams, i.e., local buckling and interface fracture, are then presented based on the proposed split bi-layer shear deformable beam model. Local buckling load of a delaminated beam considering the root rotation at the delamination tip is first obtained. By considering the root rotation at the crack tip, the buckling load is lower than the existing solution neglecting the local deformation at the delamination tip. New expressions of energy release rate and stress intensity factor considering the transverse shear effect are obtained by the solution of local deformation based on the novel split beam model, of which several new terms associated with the transverse shear force are present, and they represent an improved solution compared to the one from the classical beam model. Two specimens are analyzed with the present model, and the corresponding refined fracture parameters are provided, which are in better agreement with finite element analysis compared to the available classical solutions.
Harmonic Shapes in Finite Elasticity Under Nonuniform Loading
Authors: Wang G. F. , Schiavone P. , Ru C.-Q.
Published: August 2005

We investigate the classic (inverse) problem concerned with the design of so-called harmonic shapes for an elastic material undergoing finite plane deformations. In particular, we show how to identify such shapes for a particular class of compressible hyperelastic materials of harmonic type. The “harmonic condition,” in which the sum of the normal stresses in the original stress field remains unchanged everywhere after the introduction of the harmonic hole or inclusion, is imposed on the final stress field. Using complex variable techniques, we identify particular harmonic shapes arising when the material is subjected nonuniform (remote) loading and discuss conditions for the existence of such shapes.
The Pseudo-Rigid Rolling Coin
Authors: Epstein Marcelo , Defaz R. Ivan
Published: August 2005

A pseudo-rigid coin is a thin disk that can deform only to the extent of undergoing an arbitrary affine deformation in its own plane. The coupling of the classical rolling problem with this deformability, albeit limited, may shed light on such phenomena as the production of noise by a twirling dish. From the point of view of analytical dynamics, one of the interesting features of this problem is that the rolling constraint turns out to be nonholonomic even in the case of motion on a straight line in a vertical plane. After the analytical formulation of the general problem, explicit solutions are obtained for special shape-preserving motions. For more general motions, numerical studies are carried out for various initial conditions.
Which Formulation Allows Using a Constant Shear Modulus for
Small-Strain Buckling of Soft-Core Sandwich Structures?
Authors: Bažant Zdeněk P. , Beghini Alessandro
Published: August 2005

Although the stability theories energetically associated with different finite strain measures are mutually equivalent if the tangential moduli are properly transformed as a function of stress, only one theory can allow the use of a constant shear modulus G if the strains are small and the material deforms in the linear elastic range. Recently it was shown that, in the case of heterogeneous orthotropic structures very soft in shear, the choice of theory to use is related to the problem of proper homogenization and depends on the type of structure. An example is the difference between Engesser’s and Haringx’s formulas for critical load of columns with shear, which were shown to be energetically associated with Green’s and Almansi’s Lagrangian finite strain tensors. In a previous brief paper of the authors in a conference special issue, it was concluded on the basis of energy arguments that, for constant G, Engesser’s formula is correct for sandwich columns and Haringx’s formula for elastomeric bearings, but no supporting experimental results were presented. To present them, is the main purpose of this technical brief.
Three-Dimensional Flexure of Rectangular Plates Made of Functionally Graded Materials
Authors: Elishakoff Isaac , Gentilini Cristina
Published: August 2005

A three-dimensional solution for the problem of transversely loaded, all-round clamped rectangular plates of arbitrary thickness is presented within the linear, small deformation theory of elasticity. The Ritz minimum energy principle is employed to derive the governing equation of the plate made of functionally graded materials. In theory, if we employ an infinite number of terms in the displacement series, the exact solution can be determined. However, a practical limit always exists due to numerical implementation. The solution has a validity comparable to some higher order theories. A power-law distribution for the mechanical characteristics is adopted to model the continuous variation of properties from those of one component to those of the other. The displacements and stresses of the plate for different values of the power-law exponent are investigated.
New Approximations for Elastic Spheres Under an Oscillating Torsional Couple
Authors: Segalman Daniel J. , Starr Michael J. , Heinstein Martin W.
Published: August 2005

The Lubkin solution for two spheres pressed together and then subjected to a monotonically increasing axial couple is examined numerically. The Deresiewicz asymptotic solution is compared to the full solution and its utility is evaluated. Alternative approximations for the Lubkin solution are suggested and compared. One approximation is a Padé rational function which matches the analytic solution over all rotations. The other is an exponential approximation that reproduces the asymptotic values of the analytic solution at infinitesimal and infinite rotations. Finally, finite element solutions for the Lubkin problem are compared with the exact and approximate solutions.
Flaw Tolerance in a Thin Strip Under Tension
Authors: Gao Huajian , Chen Shaohua
Published: August 2005

Recent studies on hard and tough biological materials have led to a concept called flaw tolerance which is defined as a state of material in which pre-existing cracks do not propagate even as the material is stretched to failure near its limiting strength. In this process, the material around the crack fails not by crack propagation, but by uniform rupture at the limiting strength. At the failure point, the classical singular stress field is replaced by a uniform stress distribution with no stress concentration near the crack tip. This concept provides an important analogy between the known phenomena and concepts in fracture mechanics, such as notch insensitivity, fracture size effects and large scale yielding or bridging, and new studies on failure mechanisms in nanostructures and biological systems. In this paper, we discuss the essential concept for the model problem of an interior center crack and two symmetric edge cracks in a thin strip under tension. A simple analysis based on the Griffith model and the Dugdale-Barenblatt model is used to show that flaw tolerance is achieved when the dimensionless number Λft=ΓE∕(S2H) is on the order of 1, where Γ is the fracture energy, E is the Young’s modulus, S is the strength, and H is the characteristic size of the material. The concept of flaw tolerance emphasizes the capability of a material to tolerate cracklike flaws of all sizes.
Buckling of Shallow Spherical Caps Subjected to External Pressure
Authors: Btachut J.
Published: August 2005

This contribution details buckling tests and numerical results for shallow spherical caps subjected to static and uniform external pressure. Six mild steel caps were carefully CNC-machined from a solid billet. Three caps were designed to fail elastically with the remaining three failing within the plastic range. Caps’ shallowness parameter, λ, varied from 3.5 to 5.5, and radius-to-thickness ratio varied from 300 to 1800.
TAZ, a Transcriptional Modulator of Mesenchymal Stem Cell Differentiation
Authors: Hong Jeong-Ho , Hwang Eun Sook , McManus Michael T. , Amsterdam Adam , Tian Yu , Kalmukova Ralitsa , Mueller Elisabetta , Benjamin Thomas , Spiegelman Bruce M. , Sharp Phillip A. , Hopkins Nancy , Yaffe Michael B.
Published: August 2005

Mesenchymal stem cells (MSCs) are a pluripotent cell type that can differentiate into several distinct lineages. Two key transcription factors, Runx2 and peroxisome proliferator–activated receptor γ (PPARγ), drive MSCs to differentiate into either osteoblasts or adipocytes, respectively. How these two transcription factors are regulated in order to specify these alternate cell fates remains a pivotal question. Here we report that a 14-3-3–binding protein, TAZ (transcriptional coactivator with PDZ-binding motif), coactivates Runx2-dependent gene transcription while repressing PPARγ-dependent gene transcription. By modulating TAZ expression in model cell lines, mouse embryonic fibroblasts, and primary MSCs in culture and in zebrafish in vivo, we observed alterations in osteogenic versus adipogenic potential. These results indicate that TAZ functions as a molecular rheostat that modulates MSC differentiation.
Direct Control of Germline Stem Cell Division and Cyst Growth by Neural Insulin in
Drosophila
Authors: LaFever Leesa , Drummond-Barbosa Daniela
Published: August 2005

Stem cells reside in specialized niches that provide signals required for their maintenance and division. Tissue-extrinsic signals can also modify stem cell activity, although this is poorly understood. Here, we report that neural-derived
Drosophila
insulin-like peptides (DILPs) directly regulate germline stem cell division rate, demonstrating that signals mediating the ovarian response to nutritional input can modify stem cell activity in a niche-independent manner. We also reveal a crucial direct role of DILPs in controlling germline cyst growth and vitellogenesis.
Insurance in a Climate of Change
Authors: Mills Evan
Published: August 2005

Catastrophe insurance provides peace of mind and financial security. Climate change can have adverse impacts on insurance affordability and availability, potentially slowing the growth of the industry and shifting more of the burden to governments and individuals. Most forms of insurance are vulnerable, including property, liability, health, and life. It is incumbent on insurers, their regulators, and the policy community to develop a better grasp of the physical and business risks. Insurers are well positioned to participate in public-private initiatives to monitor loss trends, improve catastrophe modeling, address the causes of climate change, and prepare for and adapt to the impacts.
Social-Ecological Resilience to Coastal Disasters
Authors: Adger W. Neil , Hughes Terry P. , Folke Carl , Carpenter Stephen R. , Rockström Johan
Published: August 2005

Social and ecological vulnerability to disasters and outcomes of any particular extreme event are influenced by buildup or erosion of resilience both before and after disasters occur. Resilient social-ecological systems incorporate diverse mechanisms for living with, and learning from, change and unexpected shocks. Disaster management requires multilevel governance systems that can enhance the capacity to cope with uncertainty and surprise by mobilizing diverse sources of resilience.
Nature of Phosphorus Limitation in the Ultraoligotrophic Eastern Mediterranean
Authors: Thingstad T. F. , Krom M. D. , Mantoura R. F. C. , Flaten G. A. F. , Groom S. , Herut B. , Kress N. , Law C. S. , Pasternak A. , Pitta P. , Psarra S. , Rassoulzadegan F. , Tanaka T. , Tselepides A. , Wassmann P. , Woodward E. M. S. , Riser C. Wexels , Zodiatis G. , Zohary T.
Published: August 2005

Phosphate addition to surface waters of the ultraoligotrophic, phosphorus-starved eastern Mediterranean in a Lagrangian experiment caused unexpected ecosystem responses. The system exhibited a decline in chlorophyll and an increase in bacterial production and copepod egg abundance. Although nitrogen and phosphorus colimitation hindered phytoplankton growth, phosphorous may have been transferred through the microbial food web to copepods via two, not mutually exclusive, pathways: (i) bypass of the phytoplankton compartment by phosphorus uptake in heterotrophic bacteria and (ii) tunnelling, whereby phosphate luxury consumption rapidly shifts the stoichiometric composition of copepod prey. Copepods may thus be coupled to lower trophic levels through interactions not usually considered.
Atomic-Scale Sources and Mechanism of Nanoscale Electronic Disorder in Bi
2
Sr
2
CaCu
2
O
8+δ
Authors: McElroy K. , Lee Jinho , Slezak J. A. , Lee D.-H. , Eisaki H. , Uchida S. , Davis J. C.
Published: August 2005

The randomness of dopant atom distributions in cuprate high–critical temperature superconductors has long been suspected to cause nanoscale electronic disorder. In the superconductor Bi
2
Sr
2
CaCu
2
O
8+δ
, we identified populations of atomic-scale impurity states whose spatial densities follow closely those of the oxygen dopant atoms. We found that the impurity-state locations are strongly correlated with all manifestations of the nanoscale electronic disorder. This disorder occurs via an unanticipated mechanism exhibiting high-energy spectral weight shifts, with associated strong superconducting coherence peak suppression but very weak scattering of low-energy quasi-particles.