bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of energetic advantages of burst swimming of fish
Authors: Stöcker Sabine , Weihs Daniel 
Published: September 2002

AbstractIt is well‐known that fish can swim more efficiently by alternating periods of accelerated motion and powerless gliding. It has been shown numerically that this strategy is most effective for small velocities and very small variations of the accelerating and gliding mode. In the paper presented here, this has been reinvestigated analytically. By that means, the maximum energy saving obtained can be evaluated. Knowing the cheapest swimming mode in terms of energy of fish enables knowing its minimal oxygen need. In calculating the volume a fish crosses using this cheapest mode, we are able to estimate the least required oxygen concentration of the surrounding water. Therefore, we can also calculate the restriction on the size of fish schools due to oxygen limitations. The theoretical value for the maximum size of a school increases if one considers energetic advantages of schooling. These evaluations are of special interest for the estimation of fish stocks and for fishery. Copyright 2001 John Wiley & Sons, Ltd.
Control of the impedance bandwidth of wideband planar monopole antennas using a beveling technique
Authors: Ammann M. J. 
Published: September 2002

AbstractWideband planar monopole antennas have recently been proposed for use on digital mobile terminals. The square planar monopole is the simplest to analyze, and suffers little degradation of radiation pattern within the impedance bandwidth. The addition of a bevel on one or both sides of the feed probe is shown to increase the bandwidth with good control of the upper edge frequency. The impedance bandwidth ratio for this antenna is shown to vary from 2:1 to 6:1, which can be controlled by beveling the planar geometry. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 229–232, 2001.
Plasma levels of natriuretic peptides in relation to doxorubicin‐induced cardiotoxicity and cardiac function in children with cancer
Authors: Hayakawa H. , Komada Y. , Hirayama M. , Hori H. , Ito M. , Sakurai M. 
Published: September 2002

AbstractBackgroundAnthracyclines are effective anticancer drugs for childhood cancer with dose‐limiting cardiotoxicity. Children who have received anthracyclines thus need periodical cardiac evaluation. The plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) have been shown to increase in proportion to severity of cardiac dysfunction. We examined whether plasma levels of ANP and BNP, in addition to echocardiographic evaluation, can be used as specific markers for doxorubicin‐induced cardiotoxic effects in children.ProcedureConsecutively, 34 patients (18 boys and 16 girls) who had previously received doxorubicin‐containing chemotherapy were enrolled in this study. Plasma ANP and BNP were assayed simultaneously at the time of first cardiac function evaluation by echocardiography.ResultsOf the 34 patients, 8 (23.5%) had left ventricular dysfunction as assessed by echocardiography. Both ANP and BNP plasma levels in these patients were significantly elevated in comparison with healthy controls (P < 0.01) or patients with normal cardiac function (P < 0.05). It should be also noted that ANP and BNP levels were correlated significantly with cardiac systolic function, but not with diastolic function.ConclusionsThese results suggest that plasma ANP and BNP levels could be markers for doxorubicin‐induced cardiotoxicity in children. Measurement of natriuretic peptide levels during treatment may allow earlier‐identification of individuals at risk for severe cardiac damage. Med. Pediatr. Oncol. 37:4–9, 2001. © 2001 Wiley‐Liss, Inc.
Primary Ewing tumor of the vertebrae: Clinical characteristics, prognostic factors, and outcome*
Authors: Venkateswaran Lakshmi , Rodriguez‐Galindo Carlos , Merchant Thomas E. , Poquette Catherine A. , Rao Bhaskar N. , Pappo Alberto S. 
Published: September 2002

AbstractBackgroundFewer than 10% of Ewing family of tumors (EFT) arise in the vertebrae. Little information is available regarding the clinical presentation and outcome of these tumors.ProcedureWe reviewed the clinical features, prognostic factors, and outcome of EFT of the spine identified at our institution between 1962 and 1999.ResultsThirty‐three (10%) of 344 patients with EFT had a primary vertebral tumor. There were 21 (64%) males. Median age at diagnosis was 13.3 years. Six patients had metastatic disease and 10 had tumors  ≥ 8 cm in diameter. Primary sites were sacral (13), thoracic (10), lumbar (8), and cervical (2) vertebrae. We found no association between the affected spinal region and outcome, although sacral tumors were associated with delayed diagnosis (4 vs. 2 months after onset of symptoms, P = 0.076). Pain (n = 32) and neurologic deficits (n = 31; 82% motor, 58% sensory, 42% bladder, 27% bowel) were the most common presenting features. All patients received combination chemotherapy and local radiotherapy. With a median follow up of 9.7 years, 5‐year survival and event‐free survival ( ± SD) estimates were 48.1% (8.9%) and 35.6% (8.6%), respectively, comparable to those of other patients with EFT. Outcome was better for patients with tumor size  < 8 cm (P = 0.008) or localized disease (P = 0.084). Treatment era and specific tumor site did not affect outcome.ConclusionsOutcomes are similar for primary EFT of the spine and primary EFT in other sites. Unlike others, we found that patients with sacral tumors did not fare worse than patients with tumors at other spinal sites. Med. Pediatr. Oncol. 37:30–35, 2001. © 2001 Wiley‐Liss, Inc.
Pancreatoblastoma in childhood: Clinical course and therapeutic management of seven patients
Authors: Défachelles A.S. , Martin de Lassalle E. , Boutard P. , Nelken B. , Schneider P. , Patte C. 
Published: September 2002

AbstractBackgroundTo analyze the clinical course of pancreatoblastoma in children and to propose management and therapy.ProcedureRetrospective review of seven cases of pancreatoblastoma treated in France over a 20‐year period and literature review.ResultsMedian age of patients was 6 years. The tumor was well encapsulated in one patient and had direct extension to adjacent tissues in two others. Three patients had regional lymph node involvement and one had liver metastases. The tumor arose in the head of the pancreas in three children, in the tail and body in two and in the tail and in the body, one each. Elevation of AFP serum levels was noted in four out of 6 cases. Five tumor resections were performed, one initially and 4 after neoadjuvant chemotherapy, and cisplatin plus doxorubicin seemed effective. Two chidren received post‐operative irradiation because of incomplete resection. In all, four children are disease free with a median follow‐up of 50 months ( range, 5–120 months) : one had a complete removal of tumor at diagnosis and no further treatment, three had unresectable tumor at diagnosis and received neoadjuvant chemotherapy with cisplatin and doxorubicin. One of them also received post‐operative irradiation.ConclusionsPancreatoblastoma is a curable tumor. Examination of serum AFP levels may be useful for diagnosis and to follow the course of the disease. Complete resection is the treatment of choice. However, tumor is often unresectable at diagnosis and preoperative chemotherapy is needed to reduce tumor volume. We suggest a regimen that include cisplatin and doxorubicin. In patients with incompletely resected disease, postoperative radiation may be indicated. Med. Pediatr. Oncol. 37:47–52, 2001. © 2001 Wiley‐Liss, Inc.
Pulsed‐field gradient NMR study of sodium dodecyl sulfate micelle–peptide association
Authors: Deaton Kimberly R. , Feyen Elizabeth A. , Nkulabi Hassan J. , Morris Kevin F. 
Published: September 2002

AbstractPulsed‐field gradient (PFG) NMR spectroscopy was used to characterize the interactions between a series of small peptides and sodium dodecyl sulfate (SDS) micelles. The study was undertaken because peptide–micelle interactions are often exploited in the chromatographic analysis of complex mixtures, and therefore an accurate knowledge of peptide–micelle association constants is essential for a thorough understanding of the separation mechanism in these techniques. In the PFG‐NMR experiment, diffusion coefficients for each peptide were measured in free solution and in the presence of SDS micelles. These diffusion coefficients allowed the mole fraction of peptide molecules associated with SDS micelles and the peptide–micelle association constants, Keq, to be calculated. In a study of dipeptides derived from the leucine enkephalin (YGGFL) and D‐(Ala)2‐leucine enkephalin (YAGFL) amino acid sequences, only Phe–Leu was found to associate strongly with the micellar aggregates. The equilibrium constant for this dipeptide was found to be 69 ± 6 M−1. The dipeptides Tyr–Gly, Tyr–Ala, Gly–Gly and Gly–Phe exhibited little to no micelle binding, whereas Tyr–Leu had an association constant that was a factor of four less than the Phe–Leu value. Furthermore, the association constants for the pentapeptides leucine enkephalin and D‐(Ala)2‐leucine enkephalin (130 ± 8 and 584 ± 38, respectively) were both higher than the Keq values for all dipeptides investigated. These results suggest that micelle–induced changes in peptide conformation and peptide hydrophobicity both play important roles in governing peptide–micelle binding. Copyright © 2001 John Wiley & Sons, Ltd.
Real‐time measurements of cellular oxygen consumption, pH, and energy metabolism using nuclear magnetic resonance spectroscopy
Authors: Pilatus Ulrich , Aboagye Eric , Artemov Dmitri , Mori Noriko , Ackerstaff Ellen , Bhujwalla Zaver M. 
Published: September 2002

AbstractChanges in molecular expression or apoptotic behavior, induced by malignant transformation or anticancer treatment, are frequently reflected in cellular metabolism and oxygen consumption. A technique to monitor oxygen consumption, cell physiology, and metabolism noninvasively would provide a better understanding of interactions between molecular changes and metabolism in malignant transformation and following cancer treatment. Such a system was developed in this study by adapting multinuclear MRI and spectroscopic techniques to an isolated cell perfusion system. The system was evaluated by studying the effects of two agents, carbonyl cyanide m‐chlorophenylhydrazone (CCCP) which is an uncoupler of oxidative phosphorylation, and antimycin, an inhibitor of oxidative phosphorylation, on the oxygen consumption and metabolism of MCF‐7 and MatLyLu cancer cell lines. Magn Reson Med 45:749–755, 2001. © 2001 Wiley‐Liss, Inc.
Detection of myocardial viability based on measurement of sodium content: A 23Na‐NMR study
Authors: Horn Michael , Weidensteiner Claudia , Scheffer Heike , Meininger Martin , de Groot Mark , Remkes Helga , Dienesch Charlotte , Przyklenk Karin , von Kienlin Markus , Neubauer Stefan 
Published: September 2002

AbstractMRI of total sodium (Na) content may allow assessment of myocardial viability, but information on Na content in normal myocardium, necrotic/scar tissue, and stunned or hibernating myocardium is lacking. Thus, the aims of the study were to: 1) quantify the temporal changes in myocardial Na content post‐myocardial infarction (MI) in a rat model (Protocol 1); 2) compare Na in normally perfused, hibernating, and stunned canine myocardium (Protocol 2); and 3) determine whether, in buffer‐perfused rat hearts, infarct scar can be differentiated from intact myocardium by 23Na‐MRI (Protocol 3). In Protocol 1, rats were subjected to LAD ligation. Infarct/scar tissue was excised at control and 1, 3, 7, 28, 56, and 128 days post‐MI (N = 6–8 each), Na content was determined by 23Na‐NMR spectroscopy (MRS) and ion chromatography. Na content was persistently increased at all time points post‐MI averaging 306*–160*% of control values (*P < 0.0083 vs. control). In Protocol 2, 23Na‐MRS of control (baseline), stunned and hibernating samples revealed no difference in Na. In Protocol 3, 23Na‐MRI revealed a mean increase in signal intensity, to 142 ± 6% of control values, in scar tissue. A threshold of 2 standard deviations of the image intensity allowed determination of infarct size, correlating with histologically determined infarct size (r = 0.91, P < 0.0001). Magn Reson Med 45:756–764, 2001. © 2001 Wiley‐Liss, Inc.
Single‐voxel proton MRS of the human brain at 1.5T and 3.0T
Authors: Barker Peter B. , Hearshen David O. , Boska Michael D. 
Published: September 2002

AbstractSingle‐voxel proton spectra of the human brain were recorded in five subjects at both 1.5T and 3.0T using the STEAM pulse sequence. Data acquisition parameters were closely matched between the two field strengths. Spectra were recorded in the white matter of the centrum semiovale and in phantoms. Spectra were compared in terms of resolution and signal‐to‐noise ratio (SNR), and transverse relaxation times (T2) were estimated at both field strengths. Spectra at 3T demonstrated a 20% improvement in sensitivity compared to 1.5T at short echo times (TE = 20 msec), which was lower than the theoretical 100% improvement. Spectra at long echo times (TE = 272 msec) exhibited similar SNR at both field strengths. T2 relaxation times were almost twofold shorter at the higher field strength. Spectra in phantoms demonstrated significantly improved resolution at 3T compared to 1.5T, but resolution improvements in in vivo spectra were almost completely offset by increased linewidths at higher field. Magn Reson Med 45:765–769, 2001. © 2001 Wiley‐Liss, Inc.
Examining a canine model of stunned myocardium with Gd‐DTPA‐enhanced MRI
Authors: Thornhill Rebecca E. , Prato Frank S. , Pereira Raoul S. , Wisenberg Gerald , Sykes Jane 
Published: September 2002

AbstractIt has previously been shown that the distribution volume of Gd‐DTPA (λ) in infarcted, canine myocardium is higher than that of normal tissue. The purpose of this study was to determine whether stunned myocardium exhibits increased λ. Stunning was produced in beagles by means of 30 min LAD occlusion followed by 3 weeks (n = 4) reperfusion. Gd‐DTPA was infused at each imaging session and λ determined in vivo using a saturation recovery turboFLASH sequence; cine imaging was used to assess ventricular wall thickening (%WT). 201Tl uptake was used as an independent assessment of viability. %WT data confirmed that the brief insult caused prolonged, yet reversible, regional contractile dysfunction in each animal. %WT was not significantly different from baseline values by 3 weeks post‐reflow. Normal 201Tl uptake confirmed the absence of infarction. The λ of stunned tissue (λ = 0.381 ± 0.030 ml/g) was not elevated above that of normal tissue (λ = 0.398 ± 0.027 ml/g, P = NS), at any time point studied, in vivo. These data suggest that an increase in λ is a specific indicator of irreversible damage. Magn Reson Med 45:864–871, 2001. © 2001 Wiley‐Liss, Inc.
Incidence of F waves in single human thenar motor units
Authors: Thomas Christine K. , Johansson Roland S. , Bigland‐Ritchie Brenda 
Published: September 2002

AbstractF‐wave generation, axon conduction velocities, and contractile properties were compared in 44 healthy individual human thenar motor units. Force and muscle action potentials were recorded when single motor axons were stimulated intraneurally about 10 cm proximal to the elbow. Each stimulus usually evoked only one electromyographic (EMG) potential. However, in seven units (16%), a single stimulus elicited an F wave in response to 1.7 ± 1.6% (mean ± SD) of the stimuli applied. Axon conduction velocity proximal to the site of stimulation was faster than distal conduction velocity (72.7 ± 8.0 m/s versus 64.2 ± 10.5 m/s). Distal conduction velocities, twitch forces, and contraction times were similar for units that did and did not generate F waves. Thus, no obvious subset of thenar motor units generated F waves. These results provide valuable baseline information on F waves that can be used to assess changes in axon conduction, motor unit contractile properties, and motoneuron excitability in disease. © 2002 John Wiley & Sons, Inc. Muscle Nerve 25: 77–82, 2002
Diabetes, peripheral neuropathy, and old age disability
Authors: Resnick Helaine E. , Stansberry Kevin B. , Harris Tamar B. , Tirivedi Mahdvi , Smith Kimberly , Morgan Polly , Vinik Aaaron I. 
Published: September 2002

AbstractThe purpose of this study was to determine whether peripheral neuropathy explains the apparent association between diabetes and disability in old age, and to evaluate the utility of lower extremity function tests in older diabetic adults with and without neuropathy. We evaluated 39 adults, aged 70–79 years, for pressure sensation (log10g), vibration perception threshold (VPT; microns), and electrophysiologic function of the peroneal nerve. The subjects included patients with established diabetic neuropathy (DN; n = 14), diabetic controls without neuropathy (DC; n = 13), and nondiabetic controls (NDC; n = 12). Nonparametric statistical methods were used to relate neuropathy measures to performance in tests of walking speed, static and dynamic balance, coordination, and ankle strength (kilograms). Significant age‐adjusted correlations were observed between measures of sensory neuropathy and a variety of performance measures, and electrophysiologic measures were related to static balance. DN subjects had significantly higher pressure sensation than NDC (5.17 vs 3.38g, P < 0.05), higher VPT (62.5 vs 21.7 μm, P < 0.05), and lower peroneal motor response amplitudes at multiple sites. Pressure sensation and nerve conduction measures did not differ between DC and NDC. Compared with NDC, DN subjects performed significantly worse on tests of walking speed (0.99 vs 1.34 m/s; P < 0.05), static balance (4.9 vs 20.4 s; P < 0.05), dynamic balance (9.23 vs 25.52 s; P < 0.05), and coordination (6.73 vs 4.76 s; P < 0.05). No differences were observed in these measures between DC and NDC. Observed differences in physical abilities between older diabetic and nondiabetic adults may have been due to the subset of diabetic individuals with peripheral neuropathy. Quantitative measures of sensory and motor nerve function have distinct effects on physical performance. Interventions aimed at reducing the impact of diabetes‐associated disability in old age may have the greatest impact among people with peripheral neuropathy. © 2002 John Wiley & Sons, Inc. Muscle Nerve 25: 43–50, 2002
Differential regulation of survival and growth in adult sympathetic neurons: An invitro study of neurotrophin responsiveness
Authors: Orike N. , Thrasivoulou C. , Wrigley A. , Cowen T. 
Published: September 2002

AbstractThe survival and growth of embryonic and postnatal sympathetic neurons is dependent on both NGF and NT3. While it has been established that adult sensory neurons survive independently of neurotrophins, the case is less clear for adult sympathetic neurons, where the studies of survival responses to neurotrophins have relied upon using long‐term cultures of embryonic neurons. We have previously established a method to culture purified young (7 day) and adult (12 week) sympathetic neurons isolated from adult rat superior cervical ganglia (SCG) in order to examine their survival and growth responses to neurotrophins. We now show that by 12 weeks after birth virtually all neurons (90%) survive for 24 h in the absence of neurotrophins. Neuron survival is unaffected by treatment with anti‐NGF antibodies (anti‐NGF) or with the tyrosine kinase inhibitor, K252a, confirming the lack of dependence on extrinsic neurotrophins. Duration of neuron survival in culture increases significantly between E19 and day 7 and week 12 posnatally, and is similarly unaffected by the presence of anti‐NGF or K252a. Saturating concentrations of NGF and NT3 are equipotent in promoting neurite extension and branching. However, we find that NGF is more potent than NT3 in promoting neurite growth, irrespective of postnatal age. The growth‐promoting effects of NGF and NT3 are almost entirely blocked by K252a, demonstrating that these effects are mediated via activation of Trk receptors, which therefore appear to remain crucial to plasticity of adult neurons. Our results indicate that maturing neurons acquire protection against cell death, induced in the absence of neurotrophin, while retaining their growth responsiveness to these factors. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 295–305, 2001
Local stability in endogenous growth models
Authors: Martínez‐García María Pilar 
Published: September 2002

AbstractThe local stability of balanced paths in endogenous growth models is investigated. Under the fulfillment of transversality conditions, a general instability result is established. It has been proved that models with one state variable are completely unstable, whereas two alternatives are possible in models with two states: complete instability or saddle point property. Balanced paths of models with three state variables can either be completely unstable, satisfy the saddle point property with a one‐dimensional stable manifold, or have a two‐dimensional manifold approaching them. Necessary and sufficient conditions for the saddle point property to occur are given. Transversality conditions guarantee that closed contours and periodic sinuoidal motions around the balanced path are ruled out. Copyright © 2001 John Wiley & Sons, Ltd.
A small civil service in transition: the case of Estonia
Authors: Randma Tiina 
Published: September 2002

AbstractAlthough scholars have shown consistent interest in small states in past decades, the Republic of Estonia has not been included in any study of small states owing to its brief history of independent statehood. This article provides an overview of the development of the Estonian civil service, to enable readers to understand the background and scope of reforms in the 1990s. The objective of the study is to test previous findings on small states using empirical research into the Estonian civil service. Interviews with civil servants reveal a few new characteristics attributable to the size of a state such as personalization of units and organizational objectives, and additional sources of organizational instability. However, it is argued that several problems of public administration in developing countries and small states overlap, which creates difficulties in distinguishing between developmental factors and the size of the state as determinants. Copyright © 2001 John Wiley & Sons, Ltd.
Decentralization of road administration: case studies in Africa and Asia
Authors: Robinson Richard , Stiedl David 
Published: September 2002

AbstractA study of decentralization of road administration in developing countries has been undertaken, including a literature review, and field studies in Nepal, Uganda and Zambia. The findings are reported under the headings of: constitutions and governance; policy and planning; financial and fiscal aspects; institutions, management and human resources; operations; and contribution to poverty alleviation. Decentralization of road administration has potential for improving the delivery of rural transport infrastructure services. But the evidence from this study suggests that it is proving difficult to realize fully the expected benefits. Problems include: lack of local government powers to exercise political influence; insufficient financial resources; lack of management capability; and a lack of accountability mechanisms. Limited data also suggest that there is little evidence of existing decentralized systems being particularly responsive to addressing the needs of the rural poor. There is a need for the poor to be involved more actively in the planning, financing and implementation process. Different models for administrative decentralization are described and recommendations are made for approaches likely to be the most appropriate for rural transport infrastructure administration and management. Copyright © 2001 John Wiley & Sons, Ltd.