bluuebunny/crossref_metadata_2025_split huggingface dataset:
MHMR: mobility‐based hybrid multicast routing protocol in mobile ad hoc wireless networks
Authors: An Beongku , Papavassiliou Symeon 
Published: March 2003

AbstractThe field of mobile ad hoc networking has enjoyed dramatic increase in popularity over the last few years. However, owing to the fact that such networks have dynamic, sometimes rapidly changing, random, multihop topologies, the development of efficient and applicable multicast routing protocols presents many issues and challenges. In this paper we propose a Mobility‐based Hybrid Multicast Routing (MHMR) protocol suitable for mobile ad hoc networks. The main features that our proposed protocol introduces are the following: (i) mobility‐based clustering and group‐based hierarchical structure, in order to effectively support stability and scalability; (ii) group‐based (limited) mesh structure and forwarding tree concepts, in order to support the robustness of the mesh topologies, which provides ‘limited’ redundancy and the efficiency of tree forwarding simultaneously; and (iii) combination of proactive and reactive concepts that provide low route acquisition delay and low overhead. The use of dynamic mobility‐based clustering as the underlying structure is motivated by the observation that in mobile ad hoc networks communications are often among teams that tend to coordinate their movements, and as a result we can dynamically and adaptively partition the network into several groups, each with its own mobility characteristics and behaviors. In our protocol we support the creation of a limited mesh structure based on the clusterheads of the various created clusters, and not among all the members that participate in the multicast session and route, thereby reducing significantly the complexity of the created mesh topology. The performance evaluation of the proposed protocol is achieved via modeling and simulation. The corresponding results demonstrate the proposed multicast protocol's efficiency in terms of packet delivery ratio, scalability, control overhead, end‐to‐end delay as a function of mobility, packet transmission rate, and multicast group size. Copyright © 2003 John Wiley & Sons, Ltd.
A node scheduling scheme for energy conservation in large wireless sensor networks
Authors: Tian Di , Georganas Nicolas D. 
Published: March 2003

AbstractIn wireless sensor networks that consist of a large number of low‐power, short‐lived, unreliable sensors, one of the main design challenges is to obtain long system lifetime without sacrificing system original performances (sensing coverage and sensing reliability). In this paper, we propose a node‐scheduling scheme, which can reduce system overall energy consumption, therefore increasing system lifetime, by identifying redundant nodes in respect of sensing coverage and then assigning them an off‐duty operation mode that has lower energy consumption than the normal on‐duty one. Our scheme aims to completely preserve original sensing coverage theoretically. Practically, sensing coverage degradation caused by location error, packet loss and node failure is very limited, not more than 1% as shown by our experimental results. In addition, the experimental results illustrate that certain redundancy is still guaranteed after node‐scheduling, which we believe can provide enough sensing reliability in many applications. We implement the proposed scheme in NS‐2 as an extension of the LEACH protocol and compare its energy consumption with the original LEACH. Simulation results exhibit noticeably longer system lifetime after introducing our scheme than before. Copyright © 2003 John Wiley & Sons, Ltd.
The failure of new entrants in commercial banking markets: a split‐population duration analysis
Authors: DeYoung Robert 
Published: March 2003

AbstractAlmost one in four of the new commercial banks chartered in the United States during the 1980s failed. This study uses a split‐population duration model to examine failure patterns and failure determinants for these banks and compares the results to a benchmark model estimated for small established banks. The results are consistent with a “life cycle” pattern of new bank failure: compared to small established banks, newly chartered banks are initially less likely, then substantially more likely, and finally equally likely to fail. These patterns were most extreme for banks chartered just prior to the banking recession of the late 1980s or early 1990s.
Do credit unions use their tax advantage to benefit members? Evidence from a cost function
Authors: Scott Frame W , Karels Gordon V , McClatchey Christine A 
Published: March 2003

AbstractThis paper examines whether the credit union income tax subsidy is passed along to members or consumed by managers. To that end, we estimate a translog cost function for credit unions and mutual thrifts that is tailored to the unique objectives of mutually owned depository institutions. We find that credit unions with residential common bonds have higher costs than mutual thrifts, but single common bond occupational and associational credit unions are more cost efficient. Thus, it appears that residential credit unions engage in expense preference behavior and hence redirect some portion of their tax benefit away from members.
Market structure, consumer banking, and optimal level of service quality
Authors: Jackson William E. , Nandakumar Purushottaman , Roth Aleda V. 
Published: March 2003

AbstractIn this article, we use a very simple game theoretic model to investigate the influence of differing market structures, or competitive conditions, on a bank's decision to increase the level of quality of the retail, or consumer, services that it markets. The results from our model suggest that the optional level of a bank's service quality depends critically on the competitive structure of the market in which the bank operates, the degree of demand interaction between banks, and the ease of imitation of competitors' service quality innovations.We find that banks in low demand interaction markets will adopt different strategies, inducing each bank to develop its own “unique” brand of quality. It is not necessarily the case that the leading banks will lead in quality improvements. This may partially explain why some of the largest banks do not have the highest levels of consumer service quality.
An analysis of advisor choice, fees, and effort in mergers and acquisitions
Authors: Hunter William C. , Jagtiani Julapa 
Published: March 2003

AbstractThis paper investigates the choice of financial advisors in mergers and acquisitions, the fees that the targets and the acquiring firms pay to these advisors, and the speed with which advisors complete transactions. Our sample includes 5337 merger deals announced during the period January 1995 to June 2000, that involved publicly traded targets and acquirers. We find that top‐tier advisors are more likely to complete deals and to complete them in less time than lower tier advisors. However, the synergistic gains realized by the acquirers declined when top advisors were used. We also find that contingent fees play a significant role in expediting the deal completion. Surprisingly, we find that deals that are initiated by the advisors do not seem to take less time to complete. Our results suggest that the payment of larger advisory fees do not play an important role in determining the likelihood of completing the deal, but they are associated with greater acquisition gains realized by the acquirer. In addition, these synergistic gains are also associated with the switching by acquirers of their financial advisors within the same tier.
The determination of commercial bank reserve requirements
Authors: Lown Cara S. , Wood John H. 
Published: March 2003

AbstractExcess reserve ratios have been studied extensively and are believed to be endogenously determined. In contrast, required reserve ratios are conventionally treated as exogenous. However, there are public policy reasons for a positive response of reserve requirements to interest rates. These are opposed by private incentives to secure lower requirements when their cost rises with interest rates. Several kinds of evidence support the hypothesis that reserve requirements are inverse functions of interest rates, sometimes with long lags that reflect the political process. The results also suggest that banks are not passive creatures of regulation but mold their environment.
The Basel Committee proposals for a new capital accord: implications for Italian banks
Authors: Sironi Andrea , Zazzara Cristiano 
Published: March 2003

AbstractFollowing a few general considerations on the recently proposed revision of the Basel Agreement on capital adequacy, this paper focuses on the first pillar of the Basel Committee proposals, the handling of capital requirements for credit risk in the banking book. The Basel Committee envisages an approach alternatively based on external ratings or on internal rating systems for the determination of the minimum capital requirement related to bank loan portfolios. This approach supports a system of capital requirements that is more sensitive to credit risk. On the basis of specific assumptions, these requirements provide a measure of the value at risk (VaR) produced by models used by major international banks. We first address the impact of the standardised and (internal ratings‐based) IRB foundation approach using general data on Italian banks loans' portfolios default rates. We then simulate the impact of the proposed new rules on the corporate loan portfolios of Italian banks, using the unique data set of mortality rates recently published by the Bank of Italy. Three main conclusions emerge from the analysis: (i) the standardised approach implicitly penalizes Italian banks in their interbank funding as their rating is generally below AA/Aa, (ii) the average default rate experienced by Italian banks is higher than the one implied in the benchmark risk weight (BRW) proposed by the Basel Committee for the IRB foundation approach, thereby potentially leading to an increase in the regulatory risk weights, and (iii) the risk‐weight is based on an average asset correlation that is significantly higher than the one historically recorded within the Italian banks' corporate borrowers. These findings support the need for a significant revision of the basic inputs and assumptions of the Basel proposals. Finally, in relation to the conditions that allow the capital market to effectively discipline banks, we comment on the proposals advanced in relation to the third pillar of the new capital adequacy scheme.
Isozyme‐specific induction of low‐dose aspirin on cytochrome P450 in healthy subjects
Authors: Chen Xiao‐Ping , Tan Zhi‐Rong , Huang Song‐Lin , Huang Zheng , Ou‐Yang Dong‐Sheng , Zhou Hong‐Hao 
Published: March 2003

ObjectiveThis study was designed to define the effect of low‐dose aspirin administration on the activity of cytochrome P450 (CYP) in normal human subjects.MethodsAspirin, 50 mg daily, was given for 14 days to 18 nonsmoking healthy male volunteers. A modified 5‐drug cocktail procedure consisting of caffeine, mephenytoin, metoprolol, chlorzoxazone, and midazolam was performed to simultaneously assess in vivo activity of CYP1A2, CYP2C19, CYP2D6, CYP2E1, and CYP3A, respectively. The activities were assessed on 4 occasions including at baseline, after 7 and 14 daily doses of aspirin, and at 7 days after discontinuation of aspirin. Concentrations of parent drugs and corresponding metabolites in biologic samples were assayed by reversed‐phase HPLC.ResultsBoth 7‐day and 14‐day aspirin intake increased the activity of CYP2C19 significantly, as indicated by 4‐hydroxymephenytoin urinary recovery (P < .001). Induction of low‐dose aspirin on CYP2C19 was time‐dependent. CYP3A activity indices increased moderately but significantly by both 7‐day and 14‐day aspirin treatment (P < .05), but the percentage changes in CYP3A activity indices were not significant. Low‐dose aspirin had no effect on CYP1A2, CYP2D6, and CYP2E1 in vivo activity by either 7‐day or 14‐day treatment.ConclusionsThe effect of low‐dose aspirin on CYPs was enzyme‐specific. Both 7‐day and 14‐day low‐dose aspirin induced the in vivo activities of CYP2C19 but did not affect the activities of CYP1A2, CYP2D6, and CYP2E1. The effect of low‐dose aspirin on CYP3A activity awaits further confirmation. When low‐dose aspirin is used in combination with drugs that are substrates of CYP2C19, doses of the latter should be adjusted to ensure their efficacy.Clinical Pharmacology & Therapeutics (2003) 73, 264–271; doi: 10.1067/mcp.2003.14
Effect of hepatic impairment on the pharmacokinetics of atomoxetine and its metabolites
Authors: Chalon Stephan A. , Desager Jean‐Pierre , DeSante Karl A. , Frye Reginald F. , Witcher Jennifer , Long Amanda J. , Sauer John‐Michael , Golnez Jean‐Luc , Smith Brian P. , Thomasson Holly R. , Horsmans Yves 
Published: March 2003

Background and ObjectivesAtomoxetine is a treatment for attention‐deficit/hyperactivity disorder and is primarily eliminated via cytochrome P4502D6 (CYP2D6). The pharmacokinetics of atomoxetine and its primary metabolites were investigated in 10 adults with hepatic impairment (6 moderate, 4 severe) and 10 age‐ and sex‐matched control subjects, all being genotyped as CYP2D6 extensive metabolizers.MethodsA single oral 20‐mg dose of atomoxetine was given. Multiple blood samples were collected for 48 hours in healthy subjects and for 120 hours in patients. Urine was collected up to 24 hours. Before atomoxetine administration (10–20 days), sorbitol clearance and debrisoquin (INN, debrisoquine) metabolic ratio were determined as markers of hepatic blood flow and CYP2D6 activity, respectively.ResultsThe systemic clearance of atomoxetine was significantly reduced in those with hepatic impairment compared with controls, thereby resulting in increased exposure (area under the concentration‐time curve from time 0 to infinity, 1.58 versus 0.85 μg · h−1 · mL−1; P = .035) but no change in maximum concentration. Mean 4‐hydroxyatomoxetine area under the concentration‐time curve from time 0 to time t and maximum concentration were increased approximately 7‐fold and 2‐fold, respectively (P = .0001 and P = .0056, respectively). For the glucuronide conjugate of 4‐hydroxyatomoxetine, the mean half‐life was longer and the mean area under the concentration‐time curve from time 0 to infinity and the maximum concentration were lower (P = .0028, P = .003, and P = .0001, respectively). The sorbitol clearance was lower and the debrisoquin metabolic ratio was higher, reflecting reduced hepatic blood flow and decreased CYP2D6 activity, respectively. Decreased atomoxetine clearance in patients with hepatic impairment was clearly correlated with decreased CYP2D6 activity and decreased hepatic blood flow. Mean atomoxetine plasma protein binding was lower in patients with hepatic impairment compared with controls (96.5% versus 98.7%, P = .0008). Atomoxetine was well tolerated in the 2 populations.ConclusionFor patients with attention‐deficit/hyperactivity disorder who have hepatic impairment, dosage adjustment is recommended. Initial target doses should be reduced to 25% and 50% of the normal dose for patients with severe and moderate hepatic impairment, respectively.Clinical Pharmacology & Therapeutics (2003) 73, 178–191; doi: 10.1067/mcp.2003.25
Itraconazole increases but grapefruit juice greatly decreases plasma concentrations of celiprolol
Authors: Lilja Jari J. , Backman Janne T. , Laitila Jouko , Luurila Harri , Neuvonen Pertti J. 
Published: March 2003

ObjectivesOur objective was to evaluate the effects of itraconazole and grapefruit juice on the pharmacokinetics of the β‐adrenergic receptor‐blocking agent celiprolol in healthy volunteers.MethodsIn a randomized 3‐phase crossover study, 12 healthy volunteers took itraconazole 200 mg orally or placebo twice a day or 200 mL grapefruit juice 3 times a day for 2 days. On the morning of day 3, 1 hour after ingestion of itraconazole, placebo, or grapefruit juice, each subject ingested 100 mg celiprolol with 200 mL of water (placebo and itraconazole phases) or grapefruit juice. In addition, 200 mL of water or grapefruit juice was ingested 4 and 10 hours after celiprolol intake. The plasma concentrations of celiprolol, itraconazole, and hydroxyitraconazole and the excretion of celiprolol into urine were measured up to 33 hours after dosing. Systolic and diastolic blood pressures and heart rate were recorded with subjects in a sitting position before the administration of celiprolol and 2, 4, 6, and 10 hours later.ResultsDuring the itraconazole phase, the mean area under the plasma concentration‐time curve from 0 to 33 hours [AUC(0–33)] of celiprolol was 80% greater (P < .05) than in the placebo phase. During the grapefruit juice phase, the mean AUC(0–33) and peak plasma concentration values of celiprolol were reduced to about 13% (P < .001) and 5% (P < .001) of the respective placebo phase values. The cumulative excretion into urine of celiprolol was increased by 59% by itraconazole (P < .05) and decreased by 85% by grapefruit juice (P < .001). Hemodynamic variables did not differ between the phases.ConclusionsItraconazole almost doubles but grapefruit juice greatly reduces plasma concentrations of celiprolol. The itraconazole‐celiprolol interaction most likely resulted from increased absorption of celiprolol possibly as a result of P‐glycoprotein inhibition in the intestine. The reduced celiprolol concentrations during the grapefruit juice phase were probably caused by physicochemical factors that interfered with celiprolol absorption, although other mechanisms cannot be excluded. The grapefruit juice‐celiprolol interaction is probably of clinical relevance.Clinical Pharmacology & Therapeutics (2003) 73, 192–198; doi: 10.1067/mcp.2003.26
P‐glycoprotein‐mediated intestinal and biliary digoxin transport in humans
Authors: Drescher Siegfried , Glaeser Hartmut , Mürdter Thomas , Hitzl Monika , Eichelbaum Michel , Fromm Martin F. 
Published: March 2003

Background and AimsIntestinal transport by P‐glycoprotein is a recently recognized determinant of drug disposition. However, direct measurements of transporter‐mediated drug elimination into isolated segments of human small intestine are lacking.MethodsUsing a recently developed intestinal perfusion catheter, we perfused in healthy volunteers two 20‐cm jejunal segments with and without the P‐glycoprotein inhibitor quinidine before and during administration of the P‐glycoprotein inducer rifampin (INN, rifampicin).ResultsWithin 3 hours after intravenous administration of digoxin (1 mg), perfusate samples were collected. We found that 0.45% ± 0.24% and 0.83% ± 0.60% of the digoxin dose were eliminated into a jejunal segment and into bile, respectively. Perfusion of the isolated segment with quinidine reduced intestinal digoxin elimination (0.23% ± 0.08%, P = .031). During rifampin, intestinal digoxin elimination was 0.80 ± 0.59 (P = .383). Enterocyte P‐glycoprotein content correlated with the area under the plasma concentration‐time curve of digoxin (Spearman nonparametric correlation coefficient [rS] = −0.73, P = .003) and digoxin nonrenal clearance (rS = 0.52,
P = .056), as well as with intraluminal and plasma concentrations of quinidine (rS = 0.55, P = .041 and rS = −0.67, P = .009, respectively).ConclusionUsing segmental intestinal perfusion, we provide direct evidence that intestinal P‐glycoprotein mediates substantial drug elimination after intravenous administration from the systemic circulation into the gut lumen and prevents entry of luminally administered P‐glycoprotein substrates into the enterocytes. These data also highlight the relative importance of direct intestinal drug secretion in comparison with drug elimination through bile.Clinical Pharmacology & Therapeutics (2003) 73, 223–231; doi: 10.1067/mcp.2003.27
Cisapride: A potential model substrate to assess cytochrome P4503A4 activity in vivo
Authors: Lowry Jennifer A. , Kearns Gregory L. , Abdel‐Rahman Susan M. , Nafziger Anne N. , Khan Irim S. , Kashuba Angela D. M. , Schuetz Erin G. , Bertino Joseph S. , van den Anker John N. , Leeder J. Steven 
Published: March 2003

ObjectivesCisapride was compared with midazolam in vivo to determine its potential applicability as a cytochrome P450 (CYP) 3A4 “probe.” As well, we evaluated whether cisapride was transported by P‐glycoprotein.MethodsBidirectional transport assays were conducted in LLC‐PK1 cells and the derivative cell line L‐MDR1 to determine whether cisapride was a substrate for P‐glycoprotein. A pharmacokinetic study was also conducted in 17 healthy adults (n = 8 women) who received intravenous midazolam (0.025 mg/kg), oral midazolam (0.15 mg/kg), and oral cisapride (0.07 mg/kg) in a randomized crossover design. Plasma concentrations were quantitated from repeated after‐dosing blood samples by HPLC with ultraviolet detection for midazolam and HPLC with tandem mass spectrometry detection for cisapride and norcisapride. Pharmacokinetic parameters were determined by noncompartmental methods. Both linear and nonlinear regression analyses were used to examine the association between the apparent plasma clearance of midazolam and cisapride and the cisapride/norcisapride plasma concentration ratios.ResultsAlthough not a substrate for P‐glycoprotein, cisapride inhibited P‐glycoprotein with an apparent inhibition constant (Ki) of 16.1 μmol/L. Linear correlations between cisapride clearance and both intravenous and oral midazolam clearance (P = .01, r2 = 0.43 and P = .001, r2 = 0.46, respectively) were found. Cisapride/norcisapride plasma concentration ratios at 8 hours (P = .001, r2 = 0.90) and 12 hours (P = .001, r2 = 0.96), as well as cisapride plasma concentrations at these time points, were shown to accurately predict the area under the plasma concentration versus time curve for cisapride.ConclusionsCYP3A4 activity reflected by the total body clearance after oral administratioin of cisapride should be independent of transport by P‐glycoprotein. Concordance between the pharmacokinetics for cisapride and midazolam support the applicability of oral cisapride as a pharmacologic substrate to assess total CYP3A4 activity in vivo. Cisapride plasma concentration ratios at 8 or 12 hours after a single oral cisapride dose may prove useful as a single‐point determination to reflect the area under the plasma concentration versus time curve and the plasma clearance of cisapride and, as well, total CYP3A4 activity in vivo.Clinical Pharmacology & Therapeutics (2003) 73, 209–222; doi: 10.1067/mcp.2003.29