bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychiatry in the future
Authors: Priebe Stefan
Published: August 2004

European nations – including Britain – have a common pattern in their history of mental health care. Most western and central European countries established large asylums in the 19th century and engaged in some form of de-institutionalisation during the second half of the 20th century. Since the 1950s, major mental health reforms have significantly improved the quality of care. Although time of onset, pace, fashion and outcomes of reforms varied greatly between countries, throughout western Europe community-based services have been established and become part of routine service provision (Becker & Vázquez-Barquero, 2001). Compared with the heyday of the reform spirit in the 1970s, we now appear to be experiencing a relatively calm period. Developments currently seem to be dominated by fragmented pragmatism rather than by dreamy visions. This may reflect a wider trend in politics: throughout Europe, ambitious long-term visions appear less relevant as drivers for political change than was the case a few decades ago.
Upper bounds on the expected time to ruin and on the expected recovery time
Authors: Frostig Esther
Published: August 2004

It is shown that the time to ruin and the recovery time in a risk process have the same distribution as the busy period in a certain queueing system. Similarly, the deficit at the time of ruin is distributed as the idle period in a single-server queueing system. These duality results are exploited to derive upper bounds for the expected time to ruin and the expected recovery time as defined by Egídio dos Reis (2000). When the claim size is generally distributed, Lorden's inequality is applied to derive the bounds. When the claim-size distribution is of phase type, tighter upper bounds are derived.
Ergodicity properties of stress release, repairable system and workload models
Authors: Last Günter
Published: August 2004

In this paper we derive some of the main ergodicity properties of a class of Markov renewal processes and the associated marked point processes. This class represents a generic model of applied probability and is of importance in earthquake modeling, reliability theory and queueing.
Markovian bulk-arriving queues with state-dependent control at idle time
Authors: Chen Anyue , Renshaw Eric
Published: August 2004

This paper considers a Markovian bulk-arriving queue modified to allow both mass arrivals when the queue is idle and mass departures which allow for the possibility of removing the entire workload. Properties of queues which terminate when the server becomes idle are developed first, since these play a key role in later developments. Results for the case of mass arrivals, but no mass annihilation, are then constructed with specific attention being paid to recurrence properties, equilibrium queue-size structure, and waiting-time distribution. A closed-form expression for the expected queue size and its Laplace transform are also established. All of these results are then generalised to allow for the removal of the entire workload, with closed-form expressions being developed for the equilibrium size and waiting-time distributions.
Measure change in multitype branching
Authors: Biggins J. D. , Kyprianou A. E.
Published: August 2004

The Kesten-Stigum theorem for the one-type Galton-Watson process gives necessary and sufficient conditions for mean convergence of the martingale formed by the population size normed by its expectation. Here, the approach to this theorem pioneered by Lyons, Pemantle and Peres (1995) is extended to certain kinds of martingales defined for Galton-Watson processes with a general type space. Many examples satisfy stochastic domination conditions on the offspring distributions and suitable domination conditions combine nicely with general conditions for mean convergence to produce moment conditions, like the X log X condition of the Kesten-Stigum theorem. A general treatment of this phenomenon is given. The application of the approach to various branching processes is indicated. However, the main reason for developing the theory is to obtain martingale convergence results in a branching random walk that do not seem readily accessible with other techniques. These results, which are natural extensions of known results for martingales associated with binary branching Brownian motion, form the main application.
Level-crossing probabilities and first-passage times for linear processes
Authors: Basak Gopal K. , Ho Kwok-Wah Remus
Published: August 2004

Discrete time-series models are commonly used to represent economic and physical data. In decision making and system control, the first-passage time and level-crossing probabilities of these processes against certain threshold levels are important quantities. In this paper, we apply an integral-equation approach together with the state-space representations of time-series models to evaluate level-crossing probabilities for the AR(p) and ARMA(1,1) models and the mean first passage time for AR(p) processes. We also extend Novikov's martingale approach to ARMA(p,q) processes. Numerical schemes are used to solve the integral equations for specific examples.
A random hierarchical lattice: the series-parallel graph and its properties
Authors: Hambly B. M. , Jordan Jonathan
Published: August 2004

We consider a sequence of random graphs constructed by a hierarchical procedure. The construction replaces existing edges by pairs of edges in series or parallel with probability p. We investigate the effective resistance across the graphs, first-passage percolation on the graphs and the Cheeger constants of the graphs as the number of edges tends to infinity. In each case we find a phase transition at
Bose-Einstein-type statistics, order statistics and planar random motions with three directions
Authors: Leorato S. , Orsingher E.
Published: August 2004

In this paper we study different types of planar random motions (performed with constant velocity) with three directions, defined by the vectors dj = (cos(2πj/3), sin(2πj/3)) for j = 0, 1, 2, changing at Poisson-paced times. We examine the cyclic motion (where the change of direction is deterministic), the completely uniform motion (where at each Poisson event each direction can be taken with probability ) and the symmetrically deviating case (where the particle can choose all directions except that taken before the Poisson event). For each of the above random motions we derive the explicit distribution of the position of the particle, by using an approach based on order statistics. We prove that the densities obtained are solutions of the partial differential equations governing the processes. We are also able to give the explicit distributions on the boundary and, for the case of the symmetrically deviating motion, we can write it as the distribution of a telegraph process. For the symmetrically deviating motion we use a generalization of the Bose-Einstein statistics in order to determine the distribution of the triple (N0, N1, N2) (conditional on N(t) = k, with N0 + N1 + N2
= N(t) + 1, where N(t) is the number of Poisson events in [0, t]), where Nj denotes the number of times the direction dj (j = 0, 1, 2) is taken. Possible extensions to four directions or more are briefly considered.
A second-order Markov-modulated fluid queue with linear service rate
Authors: Rabehasaina Landy , Sericola Bruno
Published: August 2004

We consider an infinite-capacity second-order fluid queue governed by a continuous-time Markov chain and with linear service rate. The variability of the traffic is modeled by a Brownian motion and a local variance function modulated by the Markov chain and proportional to the fluid level in the queue. The behavior of this second-order fluid-flow model is described by a linear stochastic differential equation, satisfied by the transient queue level. We study the transient level's convergence in distribution under weak assumptions and we obtain an expression for the stationary queue level. For the first-order case, we give a simple expression of all its moments as well as of its Laplace transform. For the second-order model we compute its first two moments.
Explicit criteria for several types of ergodicity of the embedded M/G/1 and GI/M/nqueues
Authors: Hou Zhenting , Liu Yuanyuan
Published: August 2004

This paper investigates the rate of convergence to the probability distribution of the embedded M/G/1 and GI/M/nqueues. We introduce several types of ergodicity includingl-ergodicity, geometric ergodicity, uniformly polynomial ergodicity and strong ergodicity. The usual method to prove ergodicity of a Markov chain is to check the existence of a Foster–Lyapunov function or a drift condition, while here we analyse the generating function of the first return probability directly and obtain practical criteria. Moreover, the method can be extended to M/G/1- and GI/M/1-type Markov chains.
Adaptive simulation using perfect control variates
Authors: Henderson Shane G. , Simon Burt
Published: August 2004

We introduce adaptive-simulation schemes for estimating performance measures for stochastic systems based on the method of control variates. We consider several possible methods for adaptively tuning the control-variate estimators, and describe their asymptotic properties. Under certain assumptions, including the existence of a ‘perfect control variate’, all of the estimators considered converge faster than the canonical rate of n−1/2, where n is the simulation run length. Perfect control variates for a variety of stochastic processes can be constructed from ‘approximating martingales’. We prove a central limit theorem for an adaptive estimator that converges at rate A similar estimator converges at rate n−1. An exponential rate of convergence is also possible under suitable conditions.
Bubbles growing in supersaturated solutions at reduced gravity
Authors: Divinis N. , Karapantsios T. D. , Kostoglou M. , Panoutsos C. S. , Bontozoglou V. , Michels A. C. , Sneep M. C. , De Bruijn R. , Lotz H.
Published: August 2004

This work investigates bubbles growing in a liquid saturated with a dissolved gas when its temperature is locally raised above its saturation value, yet below boiling. Local supersaturation is realized by giving heat pulses of variable power and duration to a miniature heater. The experiments are conducted in a low‐gravity environment to decouple bubble growth from buoyancy effects. A diffusion model is formulated considering the spherical growth of an internally heated bubble inside a uniformly subcooled liquid. The simple case of an isothermal bubble growth is solved analytically and compared to measurements to gain some physical insight. Two distinct regions are identified in the measured bubble growth curves: the initial stages are satisfactorily described by a parabolic (diffusion) law, whereas the later stages are approximately linear. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2369–2382, 2004
New England medical center posterior circulation registry
Authors: Caplan Louis R. , Wityk Robert J. , Glass Thomas A. , Tapia Jorge , Pazdera Ladislav , Chang Hui‐Meng , Teal Phillip , Dashe John F. , Chaves Claudia J. , Breen Joan C. , Vemmos Kostas , Amarenco Pierre , Tettenborn Barbara , Leary Megan , Estol Conrad , Dewitt L. Dana , Pessin Michael S.
Published: August 2004

Among 407 New England Medical Center Posterior Circulation registry patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs then strokes, and 16% had only TIAs. Embolism was the commonest stroke mechanism (40% of patients including 24% cardiac origin, 14% intraarterial, 2% cardiac and arterial sources). In 32% large artery occlusive lesions caused hemodynamic brain ischemia. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes); the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Severe occlusive lesions (>50% stenosis) involved more than one large artery in 148 patients; 134 had one artery site involved unilaterally or bilaterally. The commonest occlusive sites were: extracranial vertebral artery (52 patients, 15 bilateral) intracranial vertebral artery (40 patients, 12 bilateral), basilar artery (46 patients). Intraarterial embolism was the commonest mechanism of brain infarction in patients with vertebral artery occlusive disease. Thirty‐day mortality was 3.6%. Embolic mechanism, distal territory location, and basilar artery occlusive disease carried the poorest prognosis. The best outcome was in patients who had multiple arterial occlusive sites; they had position‐sensitive TIAs during months to years. Ann Neurol 2004;56:389–398
Vascular endothelial growth factor prolongs survival in a transgenic mouse model of ALS
Authors: Zheng Chengyun , Nennesmo Inger , Fadeel Bengt , Henter Jan‐Inge
Published: August 2004

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with the death of motor neurons in the spinal cord and brainstem. The cause of ALS is unknown and there is no cure. This study demonstrates, for the first time, that vascular endothelial growth factor (VEGF) delays progression of symptoms and prolongs survival in a Cu/Zn superoxide dismutase (SOD1) transgenic mouse model of ALS. These observations suggest that VEGF or related compounds, might be of value in the treatment of ALS patients. Ann Neurol 2004
Ataxin‐7 aggregation and ubiquitination in infantile SCA7 with 180 CAG repeats
Authors: Ansorge Olaf , Giunti Paola , Michalik Andrej , Van Broeckhoven Christine , Harding Brian , Wood Nicholas , Scaravilli Francesco
Published: August 2004

Extremely long (>150) CAG repeats are often used to create models of polyglutamine diseases yet are very rare in humans where they manifest as pediatric multisystem syndromes of little specificity. Here, we describe an infant with 180 CAG repeats in the spinocerebellar ataxia type 7 gene and focus on systemic ataxin‐7 aggregation. This was found in many organs, including the cardiovascular system. In the brain, the hippocampus emerged as a principal site of ataxin‐7 aggregation without cell loss. We note differential ubiquitination of aggregates and discuss how this may relate to selective vulnerability. Ann Neurol 2004;56:448–452
PINK1 mutations are associated with sporadic early‐onset parkinsonism
Authors: Valente Enza Maria , Salvi Sergio , Ialongo Tamara , Marongiu Roberta , Elia Antonio Emanuele , Caputo Viviana , Romito Luigi , Albanese Alberto , Dallapiccola Bruno , Bentivoglio Anna Rita
Published: August 2004

We have recently reported homozygous mutations in the PINK1 gene in three consanguineous families with early‐onset parkinsonism (EOP) linked to the PARK6 locus. To further evaluate the pathogenic role of PINK1 in EOP and to draw genotype–phenotype correlates, we performed PINK1 mutation analysis in a cohort of Italian EOP patients, mostly sporadic, with onset younger than 50 years of age. Seven of 100 patients carried missense mutations in PINK1. Two patients had two PINK1 mutations, whereas in five patients only one mutation was identified. Age at onset was in the fourth‐fifth decade (range, 37–47 years). The clinical picture was characterized by a typical parkinsonian phenotype with asymmetric onset and rare occurrence of atypical features. Slow progression and excellent response to levodopa were observed in all subject. Two of 200 healthy control individuals also carried one heterozygous missense mutation. The identification of a higher number of patients (5%) than controls (1%) carrying a single heterozygous mutation, along with previous positron emission tomography studies demonstrating a preclinical nigrostriatal dysfunction in PARK6 carriers, supports the hypothesis that haploinsufficiency of PINK1, as well as of other EOP genes, may represent a susceptibility factor toward parkinsonism. However, the pathogenetic significance of heterozygous PINK1 mutations still remains to be clarified. Ann Neurol 2004;56:336–341
Effects of diacrylate monomers on the mechanical properties of polymer concrete made with wet aggregates
Authors: Ahn Namshik
Published: August 2004

Because normal polymer concrete does not work well with wet aggregates, diacrylate (DA) monomers were evaluated for improving the mechanical properties of polymer concrete made with wet aggregates. Zinc diacrylate (ZDA) and calcium diacrylate (CDA) were each used as an additive to resins (two epoxies). The variables were the amount of diacrylate monomers and the aggregate conditions (wet or dry). Compressive strength, flexural strength, workability, working time, and curing time were measured. ZDA was found to improve the workability and the working time, and CDA was found to improve the compressive and the flexural strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1077–1085, 2004
Effect of primary polymer chain rigidity on intramolecular cyclization and intramolecular crosslinking in free‐radical crosslinking monomethacrylate/dimethacrylate copolymerizations
Authors: Ikeda Jun‐ichi , Hasei Yasuhide , Yasuda Yuduri , Aota Hiroyuki , Matsumoto Akira
Published: August 2004

d‐Bornyl methacrylate (BoMA) was chosen as a typical example of bulky monomethacrylate monomers, the polymerization of which led to the formation of a rigid polymer chain. To discuss the effect of primary polymer chain rigidity on intramolecular cyclization, we compared the solution copolymerization results of BoMA with 1 mol % ethylene dimethacrylate (EDMA; n = 1) and poly(ethylene glycol dimethacrylate) [CH2C(CH3)CO(OCH2CH2)nOCOC(CH3)CH2, n = 9 (PEGDMA‐9)] with those of methyl methacrylate (MMA) with 1 mol % EDMA and PEGDMA‐9; the dependence of the weight‐average degree of polymerization on conversion for the former BoMA copolymerization systems was completely opposed to that for the latter MMA systems, and this was a reflection of a reduced occurrence of intramolecular cyclization caused by the rigidity of the primary polymer chain. The effect of primary polymer chain rigidity on intramolecular crosslinking was discussed through a comparison of both BoMA/EDMA and MMA/EDMA copolymerizations. The correlations of the intrinsic viscosity, root‐mean‐square (rms) radius of gyration, and second virial coefficient with the molecular weight were examined for both BoMA/EDMA (90/10) and MMA/EDMA (90/10) copolymerizations in a dilute solution because microgelation was observed in solution MMA/EDMA (90/10) copolymerization as a reflection of a locally extensive occurrence of intramolecular crosslinking. The logarithmic plots of both the intrinsic viscosity and rms radius of gyration versus the molecular weight for MMA/EDMA copolymerization were compared with those for the corresponding BoMA/EDMA copolymerizations. The second virial coefficients were greater than 10−5 mol cm3 g−2 for BoMA/EDMA copolymers, even when the conversion was very close to the gel point, whereas they were quite low, that is, less than 10−5 mol cm3 g−2, for an MMA/EDMA copolymer obtained at more than 15% conversion. These were ascribed to a suppressed occurrence of intramolecular crosslinking, a reflection of the lessened flexibility of the polymer main chain and a steric effect due to the bulky d‐bornyl groups. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1086–1093, 2004
Optimization of mechanical properties of polymer concrete and mix design recommendation based on design of experiments
Authors: Muthukumar M. , Mohan D.
Published: August 2004

A series of polymer concretes using furan resin, silica aggregates, and microfiller were prepared for statistically designed combinations. The combinations were designed based on the mixture‐design concept of design of experiments. The fillers chosen for the present investigation were high‐purity naturally occurring silica of different particle sizes, their mix proportion optimized to have minimum void. For each polymer concrete combination, the mechanical properties were studied. Each response (mechanical property) was individually optimized for maximum values and compared with the experimental data. To obtain a single‐input combination, having maximum values in all the responses, a combined optimization was done and a mix design was recommended. The coefficient of correlation between the experimental values and predicted values was found to be high, proving the fitness of the selected model. The effect of individual variables on the response was discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1107–1116, 2004
Phase behavior on the binary and ternary mixtures of poly(cyclohexyl acrylate) and poly(cyclohexyl methacrylate) in supercritical CO2
Authors: Byun Hun‐Soo
Published: August 2004

High‐pressure phase behavior was measured for the CO2–cyclohexyl acrylate and CO2–cyclohexyl methacrylate system at 40, 60, 80, 100, and 120°C and pressure up to 206 bar. This system exhibits type I phase behavior with a continuous mixture‐critical curve. The experimental results for the CO2–cyclohexyl acrylate and CO2–cyclohexyl methacrylate system were modeled using the Peng–Robinson equation of state. Experimental cloud‐point data, at a temperature of 250°C and pressure of 2800 bar, were presented for ternary mixtures of poly(cyclohexyl acrylate)–CO2–cyclohexyl acrylate and poly(cyclohexyl methacrylate)–CO2–cyclohexyl methacrylate systems. Cloud‐point pressures of poly(cyclohexyl acrylate)–CO2–cyclohexyl acrylate system were measured in the temperature range of 40 to 180°C and at pressures as high as 2200 bar with cyclohexyl acrylate concentrations of 22.5, 27.4, 33.2, and 39.2 wt %. Results showed that adding 45.6 wt % cyclohexyl acrylate to the poly(cyclohexyl acrylate)–CO2 mixture significantly changes the phase behavior. This system changed the pressure–temperature slope of the phase behavior curves from the upper critical solution temperature (UCST) region to the lower critical solution temperature (LCST) region with increasing cyclohexyl acrylate concentration. Poly(cyclohexyl acrylate) did not dissolve in pure CO2 at a temperature of 250°C and pressure of 2800 bar. Also, the ternary poly(cyclohexyl methacrylate)–CO2–cyclohexyl methacrylate system was measured below 187°C and 2230 bar, and with cosolvent of 27.4–46.7 wt %. Poly(cyclohexyl methacrylate) did not dissolve in pure CO2 at 240°C and 2500 bar. Also, when 53.5 wt % cyclohexyl methacrylate was added to the poly(cyclohexyl methacrylate)–CO2 solution, the cloud‐point curve showed the typical appearance of the LCST boundary. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1117–1125, 2004
Thermal behavior of poly(ether ketone ketone)/thermoplastic polyimide blends
Authors: Sung Chun Yong , Weiss R. A.
Published: August 2004

The phase behavior and crystallization of poly(ether ketone ketone)/polyimide blends was investigated by differential scanning calorimetry and dynamic mechanical analysis, and chemical interactions in the blends were probed by Fourier‐transform infrared spectroscopy. Amorphous blends were miscible over the entire range of composition, although mixing was most favorable at higher thermoplastic polyimide concentrations. Blending suppressed crystallization, especially of the minor component, but crystallization of both components, however, did occur in most of the blends. While blends quenched from the melt exhibited only a single amorphous phase, melt crystallized blends appeared to possess two amorphous phases with different compositions. Shifts in the vibration frequencies of the carbonyl and imide bonds were inconsistent with the development of strong, specific intermolecular interactions, but may be explained by a disruption of the packing of the two homopolymers by nature of the mixing. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1227–1235, 2004
Melt spinning and annealing of poly(ethylene terephthalate)/p‐hydroxybenzoate liquid crystalline polymer
Authors: Bang Yun Hyuk , Lee Sun Hee , Kwon Ik Hyun , Cho Hyun Hok
Published: August 2004

Poly(ethylene terephthalate)/p‐hydroxybenzoate (PET/PHB) copolymer materials have relatively low melt viscosity because of the 60 mol % PHB material having a value that is lower by approximately two orders of magnitude than the value for PET homopolymer. The structure development during melt spinning and thermal treatment (annealing) of liquid crystalline copolyesters, with a rigid backbone structure, were analyzed through the density, birefringence, X‐ray diffraction, DSC, dynamic viscoelasticity, and tensile testing. As the take‐up velocity increased, the birefringence of PET/PHB as‐spun fiber increased, which indicated that it directly influenced the initial modulus and specific stress. The lateral packing of PHB molecular chain in a copolymer was shown to be loosened in the course of thermal treatment. The thermal treatment slightly increased the crystal orientation factor, whereas total molecular orientation was decreased by annealing. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1265–1278, 2004
Synthesis and characterization of hybrid membranes using poly(vinyl alcohol) and tetraethylorthosilicate for the pervaporation separation of water–isopropanol mixtures
Authors: Kulkarni Srikant S. , Kittur Arjumand A. , Aralaguppi Mrityunjaya I. , Kariduraganavar Mahadevappa Y.
Published: August 2004

Hybrid membranes were prepared using poly(vinyl alcohol) (PVA) and tetraethylorthosilicate (TEOS) via hydrolysis and cocondensation reaction for the pervaporation separation of water‐isopropanol mixtures. The resulting membranes were characterized by Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, and differential scanning calorimetry. The glass transition temperature of these membranes varied from 100 to 120°C with increasing TEOS content. Effects of crosslinking density and feed compositions on the pervaporation performances of the membranes were studied. The membrane containing 1.5:1 mass ratio of TEOS to PVA gave the highest separation selectivity of 900 at 30°C for 10 mass % of water in the feed mixture. It was found that the separation selectivity and permeation flux data are strongly dependent on the water composition of the feed and operating temperature. However, the membrane with the highest crosslinking density showed unusual pervaporation properties. The overall activation energy values were calculated using the Arrhenius‐type equation. The activation energy values for the permeation and diffusion varied from 49.18 to 64.96 and 55.13 to 67.31 kJ/mol, respectively. Pervaporation data have also been explained on the basis of thermodynamic quantities. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1304–1315, 2004
Anatomy of efferent hepatic nerves
Authors: McCuskey Robert S.
Published: August 2004

The role of neural elements in regulating blood flow through the hepatic sinusoids, solute exchange, and parenchymal function is incompletely understood. This is due in part to limited investigation in only a few species whose hepatic innervation may differ significantly from humans. For example, most experimental studies have used rats and mice having livers with little or no intralobular innervation. In contrast, most other mammals, including humans, have aminergic and peptidergic nerves extending from perivascular plexus in the portal space into the lobule, where they course in Disse's space in close relationship to stellate cells (fat storing cells of Ito) and hepatic parenchymal cells. While these fibers extend throughout the lobule, they predominate in the periportal region. Cholinergic innervation, however, appears to be restricted to structures in the portal space and immediately adjacent hepatic parenchymal cells. Neuropeptides have been colocalized with neurotransmitters in both adrenergic and cholinergic nerves. Neuropeptide Y (NPY) has been colocalized in aminergic nerves supplying all segments of the hepatic‐portal venous and the hepatic arterial and biliary systems. Nerve fibers immunoreactive for substance P and somatostatin follow a similar distribution. Intralobular distribution of all of these nerve fibers is species‐dependent and similar to that reported for aminergic fibers. Vasoactive intestinal peptide and calcitonin gene‐related peptide (CGRP) are reported to coexist in cholinergic and sensory afferent nerves innervating portal veins and hepatic arteries and their branches, but not the other vascular segments or the bile ducts. Nitrergic nerves immunoreactive for neuronal nitric oxide (nNOS) are located in the portal tract where nNOS colocalizes with both NPY‐ and CGRP‐containing fibers. In summary, the liver is innervated by aminergic, cholinergic, peptidergic, and nitrergic nerves. While innervation of structures in the portal tract is relatively similar between species, the extent and distribution of intralobular innervation are highly variable as well as species‐dependent and may be inversely related to the density of gap junctions between contiguous hepatic parenchymal cells. © 2004 Wiley‐Liss, Inc.
Tragfähigkeit dreiseitig eingespannter Rechteckplatten mit einem freien Rand unter Randbelastung
Authors: Herzog Max
Published: August 2004

Es wird die Berechnung der Tragfähigkeit dreiseitig eingespannter Rechteckplatten mit einem freien Rand unter einer Randstreckenlast und unter einer Randeinzellast mit dem Fließgelenkverfahren gezeigt und anhand eines Zahlenbeispiels mit der bisher üblichen “elastischen” Berechnung verglichen.
Stahlbetonträger mit zweiachsiger Querkraftbeanspruchung
Authors: Mark Peter
Published: August 2004

Für die Schubbemessung von Stahlbetonträgern mit zweiachsiger Querkraftbeanspruchung werden räumliche Fachwerkmodelle entwickelt. Dazu wird der Vektor der resultierenden Querkraft in Einzelanteile aufgeteilt und damit die schräge Betondruckstrebe in Einzelstreben aufgelöst. Die Modelle gelten für Stahlbetonträger mit Rechteckquerschnitt und bestehen aus Zugstreben von Bügeln und Längsstäben, allgemein räumlichen Betondruckstreben sowie aussteifenden Druckstreben in Bügelebene. Sie werden an Experimenten qualitativ verifiziert und zur Ableitung von Bemessungsdiagrammen für die Bügelbemessung erweitert. Ein Beispiel zeigt die praktische Anwendung der Diagramme.
Mammographic tumor features can predict long‐term outcomes reliably in women with 1–14‐mm invasive breast carcinoma
Authors: Tabar Laszlo , Tony Chen Hsiu‐Hsi , Amy Yen M. F. , Tot Tibor , Tung Tao‐Hsin , Chen Li‐Sheng , Chiu Yueh‐Hsia , Duffy Stephen W. , Smith Robert A.
Published: August 2004

BACKGROUND

The radiologic images of 1–14‐mm invasive breast carcinomas can be classified into 5 separate categories. The use of these mammographic indicators to predict patient outcome has important prognostic and therapeutic implications.

METHODS

To verify the results of previous studies conducted with smaller numbers of patients, the authors studied the 24‐year survival of 714 women with 1–14‐mm invasive breast carcinoma according to mammographic prognostic factors. The association of mammographic features with lymph node status, histologic malignancy grade, and 24‐year survival in 714 women with invasive breast carcinomas that measured 1–14 mm also was evaluated. Adjustments were made for tumor characteristics and treatment factors in the survival analysis.

RESULTS

The most common mammographic feature was a stellate lesion with no associated calcifications (420 women; 59%). Patients with stellate lesions had excellent long‐term survival (95%). Casting‐type calcifications were observed in 52 women (7%) and were associated significantly with a positive lymph node status (odds ratio [OR], 3.29; 95% confidence interval [95% CI], 1.41–7.67), poorer histologic grade (OR, 7.04; 95% CI, 3.77–13.16), and an increased risk of death from breast carcinoma (HR, 9.19; 95% CI, 4.18–20.17). Except for women who had tumors with associated casting‐type calcifications, all other women with tumors < 10 mm in size had excellent survival regardless of lymph node status, histologic grade, or treatment. For women who had casting‐type calcifications, survival was poorer even in the group with tumors that measured 1–9 mm (72% at 20 years). For women with 10–14‐mm tumors, the 20‐year survival rate was 52% for those who had casting calcifications and 86–100% those for those who had other mammographic features.

CONCLUSIONS

The subgroup of women who had small invasive breast carcinomas accompanied by casting‐type calcifications had an unexpectedly poor prognosis for this tumor‐size category. The process of neoductgenesis offers a possible explanation for the unexpectedly poor outcome. There is a need to develop treatment protocols for this group and to reevaluate the present TNM classification system for mammographically detected 1–14‐mm breast carcinomas. After excluding women who had tumors associated with casting‐type calcifications, the remaining women had an extremely good prognosis when they were treated with surgery alone. Due to their already excellent survival, adjuvant therapeutic regimens are unlikely to offer further benefit for these patients. Cancer 2004. © 2004 American Cancer Society.
Hydrodynamic and Kinetic Modelling of Dust Free and Dusty Radio‐Frequency Discharges
Authors: Goedheer W. J. , Akdim M. R. , Chutov Yu. I.
Published: August 2004

In this paper hydrodynamic and kinetic approaches to model low pressure capacitively coupled radio‐frequency discharges are discussed. In particular approaches and results for power modulated discharges in a mixture of silane and hydrogen and for discharges containing a considerable amount of dust particles will be presented. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurements of Electron‐Impact Excitation Cross Sections out of the Ground and Metastable Levels of Rare Gases with Applications to Low‐Temperature Plasmas
Authors: Lin Chun C.
Published: August 2004

Methods for measuring cross sections for electron‐impact excitation into the 2p levels (Paschen's notation) out of the metastable levels of argon are described. The results of the cross sections and their relation to the corresponding cross sections for excitation out of the ground state are explained by a multi‐pole field model. Applications to plasma diagnostics are discussed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plasma Processing of Materials at the Atomic Scale
Authors: Braithwaite N. St. J. , Matsuura T.
Published: August 2004

Plasma etching is finding new applications beyond the microelectronics industry. There are new challenges in the devising and controlling of plasma‐surface interactions. Atomic monolayers offer opportunities for passivation and etching. Maintaining appropriate plasma conditions to exploit such opportunities requires ‘intelligent’ strategies for the control of processing plasmas. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct Monte Carlo Methods in Nonequilibrium Kinetics
Authors: Bruno D. , Capitelli M. , Longo S.
Published: August 2004

In this paper we review our work in the field of simulation of nonequilibrium molecular flows by means of the Direct Simulation Monte Carlo method. The DSMC method is introduced and its peculiar features with respect to nonequilibrium modeling are discussed. Successful application of the method has been demonstrated for different situations where limitations and results will be presented. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High Density Cascaded Arc Produced Plasma Expanding in a Low Pressure Region
Authors: Dahiya R. P. , Kumari N. , Veremiyenko V. P. , van Rooij G. J. , de Groot B. , Goedheer W. J. , Kruijtzer G. L. , Wolff J. C. , Lopes Cardozo N. J.
Published: August 2004

Experimental measurements made in thermal expanding argon, nitrogen and hydrogen plasmas with particular reference to molecular kinetics, surface nitriding and intense flux in magnetic field are discussed. The plasma is generated in a cascaded arc source. In the presence of molecular species (H2 / N2) dissociative recombination reactions involving rovibrationally excited molecules contribute to a rapid decay of the plasma species, especially for hydrogen system. A combination of nitrogen and hydrogen plasma gives an efficient plasma nitriding process, which has been applied for case hardening of machinery components. In another setup a strong axial magnetic field (0.4 ‐ 1.6 T) contains and substantially prolongs the plasma beam in the chamber. In the presence of the magnetic field, an additional current drawn through the plasma beam using a biased substrate and a ring creates dense low temperature plasma giving a new unexplored plasma regime. The plasma kinetics are modified in this regime from the recombining to the ionising mode. When the additional current in the argon plasma beam exceeds 30 A, its light emission is predominantly in the blue region. With the additional current and magnetic field, the emission intensity of Hβ and other lines arising from higher energy levels in the hydrogen Balmer series is enhanced. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of flow cytometric immunophenotyping in improving the diagnostic accuracy in referred fine‐needle aspiration specimens
Authors: Sigstad Eva , Dong Hiep Phuc , Davidson Ben , Berner Aasmund , Tierens Anne , Risberg Björn
Published: August 2004

Flow cytometric (FCM) immunophenotyping has an important role in the diagnostic work up of fine‐needle aspiration (FNA) specimens obtained from lymphoid lesions. The objective of the present study was to evaluate the feasibility of this method with respect to referred FNA specimens. One hundred and two FNA specimens referred to our laboratory for FCM analysis during the last 3 years were studied. Specimens were sent, accompanied by cytological smears, from 11 distant hospitals by ordinary mail. The evaluation of potential B‐cell monoclonality, the main diagnostic issue to be resolved using FCM, was possible in 86 of these 102 cases. The remaining 16 samples could not be analyzed or adequately interpreted because of sparse or necrotic material. A monoclonal B‐cell population was found in 17/86 satisfactory cases, of which 16 were histologically confirmed. Eight cases contained cells positive for the epithelial marker Ber‐EP4 and were diagnosed accordingly as carcinomas. FCM analysis of specimens obtained with a clinical question of Hodgkin lymphoma or T‐cell lymphomas did not yield definitive data. The time lapse between sampling and analysis (12–84 hr) did not affect the results. This probably was due to the fact that all aspirates were taken in Roswell Park Memorial Institute (RPMI) cell medium, supplemented with 50% fetal calf serum. In conclusion, this retrospective study establishes that it is possible, in the majority of cases, to refer FNA material for FCM immunophenotyping by mail, and that results regarding B‐cell clonality in the case of small‐cell lymphomas are reliable also after a transportation period of 3–4 days. Carcinoma may be similarly diagnosed and a diagnosis of lymphoma may be excluded in reactive proliferations. Cases with only a few atypical cells or specimens from patients suspected of having Hodgkin lymphoma or T‐cell lymphomas are not suitable for analysis by FCM. Diagn. Cytopathol. 2004;31:159–163. © 2004 Wiley‐Liss, Inc.
Public and private pharmaceutical spending as determinants of health outcomes in Canada
Authors: Crémieux Pierre‐Yves , Meilleur Marie‐Claude , Ouellette Pierre , Petit Patrick , Zelder Martin , Potvin Ken
Published: August 2004

An Erratum has been published for this article in Health Economics; 14(2): 117 (2005).

Canadian per capita drug expenditures increased markedly in recent years and have become center stage in the debate on health care cost containment. To inform public policy, these costs must be compared with the benefits provided by these drugs. This paper measures the statistical relationship between drug spending in Canadian provinces and overall health outcomes. The analysis relies on more homogenous data and includes a more complete set of controls for confounding factors than previous studies. Results show a strong statistical relationship between drug spending and health outcomes, especially for infant mortality and life expectancy at 65. This relationship is almost always stronger for private drug spending than for public drug spending. The analysis further indicates that substantially better health outcomes are observed in provinces where higher drug spending occurs. Simulations show that if all provinces increased per capita drug spending to the levels observed in the two provinces with the highest spending level, an average of 584 fewer infant deaths per year and over 6 months of increased life expectancy at birth would result. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of practice budgets on patient waiting times: allowing for selection bias
Authors: Dusheiko Mark , Gravelle Hugh , Jacobs Rowena
Published: August 2004

Under the UK fundholding scheme, general practices could elect to hold a budget to meet the costs of some types of elective surgery (chargeable admissions) for their patients. It was alleged that patients of fundholding practices had shorter waits for elective surgery than the patients of non‐fundholders. Comparison of waiting times between fundholding and non‐fundholding practices are potentially confounded by selection bias as fundholding was voluntary. We estimate the effect of a practice's fundholding status on the waiting times of its patients using both cross‐sectional methods (OLS, propensity score, instrumental variables, Heckman selection correction and Heckman heterogenous effects estimators) and difference in differences methodologies to correct for selection bias. The estimated effect of fundholding status was to significantly reduce the waiting times for chargeable admissions of the patients of fundholders by 4.1–6.6% (or 4–7 days) with the instrumental variables and Heckman selection correction estimators yielding the highest estimates. We also find that patients of fundholding practices had shorter waits (by 3.7% or 2 days) for non‐chargeable elective admissions, suggesting that fundholders were able to obtain shorter waits for all types of elective admissions. Copyright © 2004 John Wiley & Sons, Ltd.
Crowding in extremophiles: linkage between solvation and weak protein–protein interactions, stability and dynamics, provides insight into molecular adaptation
Authors: Ebel Christine , Zaccai Giuseppe
Published: August 2004

The study of the molecular adaptation of microorganisms to extreme environments (solvent, temperature, etc.) has provided tools to investigate the complex relationships between protein–solvent and protein–protein interactions, protein stability and protein dynamics, and how they are modulated by the crowded environment of the cell. We have evaluated protein–solvent and protein–protein interactions by solution experiments (analytical ultracentrifugation, small angle neutron and X‐ray scattering, density) and crystallography, and protein dynamics by energy resolved neutron scattering. This review concerns work from our laboratory on (i) proteins from extreme halophilic Archaea, and (ii) psychrophile, mesophile, thermophile and hyperthermophile bacterial cells. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of macromolecular crowding on protein aggregation and amyloid fibril formation
Authors: Munishkina Larissa A. , Cooper Elisa M. , Uversky Vladimir N. , Fink Anthony L.
Published: August 2004

Macromolecular crowding is expected to have several significant effects on protein aggregation; the major effects will be those due to excluded volume and increased viscosity. In this report we summarize data demonstrating that macromolecular crowding may lead to a dramatic acceleration in the rate of protein aggregation and formation of amyloid fibrils, using the protein α‐synuclein. The aggregation of α‐synuclein has been implicated as a critical factor in development of Parkinson's disease. Various types of polymers, from neutral polyethylene glycols and polysaccharides (Ficolls, dextrans) to inert proteins, are shown to accelerate α‐synuclein fibrillation. The stimulation of fibrillation increases with increasing length of polymer, as well as increasing polymer concentration. At lower polymer concentrations (typically up to ∼100 mg/ml) the major effect is ascribed to excluded volume, whereas at higher polymer concentrations evidence of opposing viscosity effects become apparent. Pesticides and metals, which are linked to increased risk of Parkinson's disease by epidemiological studies, are shown to accelerate α‐synuclein fibrillation under conditions of molecular crowding. Copyright © 2004 John Wiley & Sons, Ltd.
Applications of time‐resolved resonance energy transfer measurements in studies of the molecular crowding effect
Authors: Ittah Varda , Kahana Edith , Amir Dan , Haas Elisha
Published: August 2004

The native structures of many globular proteins are only weakly stabilized and form in solution ensembles of multiple conformers. The energy differences between the conformers are assumed to be small. This is the case of flexible multidomain proteins where domain motions were observed. High concentrations of inert macrosolute, which create a crowded or confined environment, can cause shifts of the distribution of the conformers of such proteins towards the more compact structures. This effect may also promote compact structures in partially folded proteins. Time‐resolved dynamic non‐radiative excitation energy transfer (tr‐RET) is suitable for detection of either subtle or major changes in distributions of intramolecular distances in protein molecules in solutions. Two experiments were performed which demonstrated the applicability of tr‐RET for detection of the effect of macrosolutes on the conformational ensembles of flexible states of protein molecules. The distribution of distances between residues 203 and 169 in the CORE domain of E. coli adenylate kinase (AK) in the denatured state was determined in the presence of high concentrations of dextran 40. A significant shift of the mean of the distribution was observed without reduction of its width. This was interpreted as a shift to compact structure without change of the degree of disorder of the chain. In a second experiment the distribution of the distance between residues 55 and 169 in AK, which spans the cleft between the CORE and the AMPbind domains, was monitored. No clear effect of high concentrations of dextran 40 was found. These experiments show the strength of the application of tr‐RET in investigation of changes in the sub‐states of flexible conformations of globular protein. Networks of pairs of labeled sites can be prepared and tr‐RET experiments can be performed in order to search for the segments of the protein molecules, which respond to the presence of inert macromolecules in their environment. Copyright © 2004 John Wiley & Sons, Ltd.
A potential role for isothermal calorimetry in studies of the effects of thermodynamic non‐ideality in enzyme‐catalyzed reactions
Authors: Lonhienne Thierry G. A. , Winzor Donald J.
Published: August 2004

Attention is drawn to the feasibility of using isothermal calorimetry for the characterization of enzyme reactions under conditions bearing greater relevance to the crowded biological environment, where kinetic parameters are likely to differ significantly from those obtained by classical enzyme kinetic studies in dilute solution. An outline of the application of isothermal calorimetry to the determination of enzyme kinetic parameters is followed by considerations of the nature and consequences of crowding effects in enzyme catalysis. Some of those effects of thermodynamic non‐ideality are then illustrated by means of experimental results from calorimetric studies of the effect of molecular crowding on the kinetics of catalysis by rabbit muscle pyruvate kinase. This review concludes with a discussion of the potential of isothermal calorimetry for the experimental determination of kinetic parameters for enzymes either in biological environments or at least in media that should provide reasonable approximations of the crowded conditions encountered in vivo. Copyright © 2004 John Wiley & Sons, Ltd.