bluuebunny/crossref_metadata_2025 huggingface dataset:
Dielectrophoresis of nanoparticles
Authors: Kadaksham Arun T. J. , Singh Pushpendra , Aubry Nadine
Published: November 2004

A numerical scheme based on the distributed Lagrange multiplier method (DLM) is used to study the motion of nano‐sized particles of dielectric suspensions subjected to uniform and nonuniform electric fields. Particles are subjected to both electrostatic and hydrodynamic forces, as well as Brownian motion. The results of the simulations presented in this paper show that uniform electric fields the evolution of the particle structures depends on the ratio of electrostatic particle‐particle interactions and Brownian forces. When this ratio is of the order of 100 or greater, particles form stable chains and columns, whereas when it is of the order of 10 or smaller the particle distribution is random. For the nonuniform electric field cases considered in this paper, the relative magnitude of Brownian forces is in the range such that it does not influence the eventual collection of particles by dielectrophoresis and the particular locations where the particles are collected. However, Brownian motion is observed to influence the transient particle trajectories. The deviation of the particle trajectories compared to those determined by the electrostatic and hydrodynamic forces alone is characterized by the ratio of Brownian and dielectrophoretic forces.
Integrated selective enrichment target – a microtechnology platform for matrix‐assisted laser desorption/ionization‐mass spectrometry applied on protein biomarkers in prostate diseases
Authors: Ekström Simon , Wallman Lars , Malm Johan , Becker Charlotte , Lilja Hans , Laurell Thomas , Marko‐Varga György
Published: November 2004

The performance of a miniaturized sample processing platform for matrix‐assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS), manufactured by silicon microfabrication, called integrated selective enrichment target (ISET) technology was evaluated in a biological context. The ISET serves as both sample treatment device and MALDI‐MS target, and contains an array of 96 perforated nanovials, which each can be filled with 40 nL of reversed‐phase beads. This methodology minimizes the number of sample transfers and the total surface area available for undesired adsorption of the analytes in order to provide high‐sensitivity analysis. ISET technology was successfully applied for characterization of proteins coisolated by affinity chromatography of prostate‐specific antigen (PSA) from human seminal fluid. The application of ISET sample preparation enabled multiple analyses to be performed on a limited sample volume, which resulted in the discovery that prolactin inducible protein (PIP) was coisolated from the samples.
Recent developments in detection for microfluidic systems
Authors: Mogensen Klaus B. , Klank Henning , Kutter Jörg P.
Published: November 2004

Microfluidic systems have become more and more important in the field of analytical chemistry. Detection methods on these microsystems are essential for the identification and quantification of chemical species that are being analyzed. This review concentrates on the latest developments of optical detection methods and mass spectrometry in conjunction with microfluidic systems. Electrochemical methods are discussed in another review in the same issue of this journal. Within the optical detection section, topics such as multiplexed detection and the use of waveguides are discussed. Within the discussion of mass spectrometry, the main focus is on electrospray emitters as interfaces between microsystem and spectrometer. Apart from optical detection and mass spectrometry, other techniques such as flame ionization and nuclear magnetic resonance are also mentioned.
Peak compression and resolution for electrophoretic separations in diverging microchannels
Authors: Ross David , Ivory Cornelius F. , Locascio Laurie E. , Van Cott Kevin E.
Published: November 2004

We report the results of experiments and simulations on electrokinetic flow in diverging microchannels (with cross‐sectional area that increases with distance along the channel). Because of conservation of mass and charge, the velocity of an analyte in the channel decreases as the channel cross‐section increases. Consequently, the leading edge of a band of sample moves more slowly than the trailing edge and the sample band is compressed. Sample peak widths, rather than increasing diffusively with time, can then be controlled by the geometry of the channel and can even be made to decrease with time. We consider the possibility of using this peak compression effect to improve the resolution of electrophoretic separations. Our results indicate that for typical separations that are dispersion limited, this peak compression effect is more than offset by the decreased distance between peaks, and the separation resolution in diverging channels is worse than that found for straight channels at the same applied voltage. For separations in very short channels or at very high field strengths, however, when the separation efficiency is injection limited, the peak compression effect is dominant and diverging channels can then be used to achieve improved separation resolution.
Antihyperlipidaemic effect of Aegle marmelos fruit extract in streptozotocin‐induced diabetes in rats
Authors: Kamalakkannan N , Stanely Mainzen Prince P
Published: November 2004

The present study determines the effect of an aqueous extract of Aegle marmelos fruits on serum and tissue lipids in experimental diabetes. Albino Wistar rats were rendered diabetic by intraperitoneal administration of streptozotocin (45 mg kg−1). Serum and tissue lipids such as total cholesterol, triglycerides, free fatty acids and phospholipids were elevated in diabetic rats. Oral administration of A marmelos fruit extract at doses of 125 and 250 mg kg−1 to diabetic rats twice daily for 1 month led to a significant lowering of these lipids in diabetic rats. The effect exerted by the fruit extract at a dose of 250 mg kg−1 was greater than that of the dose of 125 mg kg−1 or of glibenclamide (300 µg kg−1). The results of this study demonstrate that an aqueous A marmelos fruit extract exhibits an antihyperlipidaemic effect in streptozotocin‐induced diabetic rats. Copyright © 2004 Society of Chemical Industry
Denk das Undenkbare!
Authors: Erben Roland Franz , Romeike Frank
Published: November 2004

Terror, Naturkatastrophen, die Risiken der Technik … in der jüngsten Vergangenheit ist unsere Welt nicht unbedingt sicherer geworden. Wir sprachen Dr. Lutz Cleemann über die dramatischen Veränderungen der Risiko‐Situation und wie Unternehmen hierauf reagieren können.
A continuous record of temperature evolution over a sequence of Dansgaard‐Oeschger events during Marine Isotopic Stage 4 (76 to 62 kyr BP)
Authors: Landais A. , Barnola J. M. , Masson‐Delmotte V. , Jouzel J. , Chappellaz J. , Caillon N. , Huber C. , Leuenberger M. , Johnsen S. J.
Published: November 2004

Our knowledge of the temperature evolution over Greenland during Dansgaard‐Oeschger events (DO) is currently qualitatively described through the water isotopic profile. Using two independent paleothermometry methods, one based on air isotopic measurements and the other on the combined measurements of water isotopes (δD and δ18O), we show a complete and quantitative reconstruction of temperature at the NorthGRIP site over the period 76 to 62 kyr BP (DO 18, 19 and 20). We confirm that the associated warmings are larger than those conventionally depicted by the water isotopes (11°C, 16°C and 11°C for DO 18, 19 and 20). Secondly, we demonstrate that the relationship between temperature and δ18O varies rapidly during the last glacial period, even over a DO. Finally, our temperature reconstruction over DO 19 agrees well with that predicted from simple climate models linking the DO to iceberg discharges.
NMR structure of the bovine prion protein isolated from healthy calf brains
Authors: Hornemann Simone , Schorn Christian , Wüthrich Kurt
Published: November 2004

NMR structures of recombinant prion proteins from various species expressed in Escherichia coli have been solved during the past years, but the fundamental question of the relevancy of these data relative to the naturally occurring forms of the prion protein has not been directly addressed. Here, we present a comparison of the cellular form of the bovine prion protein isolated and purified from healthy calf brains without use of detergents, so that it contains the two carbohydrate moieties and the part of the GPI anchor that is maintained after enzymatic cleavage of the glycerolipid moiety, with the recombinant bovine prion protein expressed in E. coli. We show by circular dichroism and 1H‐NMR spectroscopy that the three‐dimensional structure and the thermal stability of the natural glycoprotein and the recombinant polypeptide are essentially identical. This result indicates possible functional roles of the glycosylation of prion proteins in healthy organisms, and provides a platform and validation for future work on the structural biology of prion proteins, which will have to rely primarily on the use of recombinant polypeptides.
Role of strategic investors in Polish companies: Catalysts for organizational change or opportunists?
Authors: Janowicz Martyna , Piaskowska Dorota , Trojanowski Grzegorz
Published: November 2004

Abstract The entry of large activist (or so‐called ‘strategic’) investors has become a prevalent phenomenon in transforming economies, such as the Polish one. This paper investigates the relationship between firm performance and the likelihood of a strategic investor entry, as well as the changes firms undergo under control of an activist investor. Theoretical predictions and empirical analyses of 211 Polish companies in the period of 1994–2000 allow us to conclude that strategic investors are more likely to buy stakes in firms of higher labor productivity, and tend to catalyze changes in poorly performing firms. There is also some evidence that investors refrain from committing resources to restructuring the target firms before seizing significant control over them.
1. The Poverty of Deductivism: A Constructive Realist Model of Sociological Explanation
Authors: Gorski Philip S.
Published: November 2004

Despite the lip service which many sociologists pay to Popper's hypothetico-deductive model (HDM) of theory testing, few if any major social theories have been definitively falsified. The reason is that sociological explanations do not fit the deductivist model of explanation: They do not contain universal or statistical “covering laws” from which falsifiable hypotheses could be deduced. Sociological explanations are better conceived in realist terms as causal models of the social processes that produce certain outcomes. While few models are completely false, some are nonetheless more empirically adequate than others. This essay argues that (1) the CLM is inadequate to sociology and that (2) attempts to reformulate the HDM are therefore destined to fail. It then outlines (3) a constructive realist model (CRM) of sociological explanation and uses it to develop (4) explanatory realist (ER) criteria for evaluating explanations. Deductivist and realist approaches to methodology are then compared through an examination of Skocpol's States and Social Revolutions.
3. Measures of Spatial Segregation
Authors: Reardon Sean F. , O'Sullivan David
Published: November 2004

The measurement of residential segregation patterns and trends has been limited by a reliance on segregation measures that do not appropriately take into account the spatial patterning of population distributions. In this paper we define a general approach to measuring spatial segregation among multiple population groups. This general approach allows researchers to specify any theoretically based definition of spatial proximity desired in computing segregation measures. Based on this general approach, we develop a general spatial exposure/isolation index ( ), and a set of general multigroup spatial evenness/clustering indices: a spatial information theory index ( ), a spatial relative diversity index ( ), and a spatial dissimilarity index ( ). We review these and previously proposed spatial segregation indices against a set of eight desirable properties of spatial segregation indices. We conclude that the spatial exposure/isolation index *—which can be interpreted as a measure of the average composition of individuals' local spatial environments—and the spatial information theory index —which can be interpreted as a measure of the variation in the diversity of the local spatial environments of each individual—are the most conceptually and mathematically satisfactory of the proposed spatial indices.
5. Sampling and Estimation in Hidden Populations Using Respondent-Driven Sampling
Authors: Salganik Matthew J. , Heckathorn Douglas D.
Published: November 2004

Standard statistical methods often provide no way to make accurate estimates about the characteristics of hidden populations such as injection drug users, the homeless, and artists. In this paper, we further develop a sampling and estimation technique called respondent-driven sampling, which allows researchers to make asymptotically unbiased estimates about these hidden populations. The sample is selected with a snowball-type design that can be done more cheaply, quickly, and easily than other methods currently in use. Further, we can show that under certain specified (and quite general) conditions, our estimates for the percentage of the population with a specific trait are asymptotically unbiased. We further show that these estimates are asymptotically unbiased no matter how the seeds are selected. We conclude with a comparison of respondent-driven samples of jazz musicians in New York and San Francisco, with corresponding institutional samples of jazz musicians from these cities. The results show that some standard methods for studying hidden populations can produce misleading results.
7. Assessing Bias in the Estimation of Causal Effects: Rosenbaum Bounds on Matching Estimators and Instrumental Variables Estimation with Imperfect Instruments
Authors: DiPrete Thomas A. , Gangl Markus
Published: November 2004

Propensity score matching provides an estimate of the effect of a “treatment” variable on an outcome variable that is largely free of bias arising from an association between treatment status and observable variables. However, matching methods are not robust against “hidden bias” arising from unobserved variables that simultaneously affect assignment to treatment and the outcome variable. One strategy for addressing this problem is the Rosenbaum bounds approach, which allows the analyst to determine how strongly an unmeasured confounding variable must affect selection into treatment in order to undermine the conclusions about causal effects from a matching analysis. Instrumental variables (IV) estimation provides an alternative strategy for the estimation of causal effects, but the method typically reduces the precision of the estimate and has an additional source of uncertainty that derives from the untestable nature of the assumptions of the IV approach. A method of assessing this additional uncertainty is proposed so that the total uncertainty of the IV approach can be comparedwith the Rosenbaum bounds approach to uncertainty using matching methods. Because the approaches rely on different information and different assumptions, they provide complementary information about causal relationships. The approach is illustrated via an analysis of the impact of unemployment insurance on the timing of reemployment, the postunemployment wage, and the probability of relocation, using data from several panels of the Survey of Income and Program Participation (SIPP).
Macular amyloidosis: An assessment of prevalence, sex, and age
Authors: Rasi Abbas , Khatami Alireza , Javaheri Saeid Mirzazadeh
Published: November 2004

Macular amyloidosis is a relatively common cutaneous disease in Asia and the Middle East. It is characterized by a reticulated or rippled pattern of pigmentation mostly in the upper back. This study was performed not only to determine the disease sex and age distribution, but also to evaluate its risk factors and the frequency among the dermatology clinic patients.

Based on the clinical and random histopathologic findings, 100 macular amyloidosis patients were evaluated in a period of 3 years. Although the sex distribution (9 : 1, female : male ratio) differed dramatically from most of the previous reports, it was consistent with few other series. Eighty one percent of patients were between 21 and 50 years of age. The mean age of the female patients was higher than that of the males (difference of two means was 10.26 years and P = 0.027). Backscatching during bathing probably is not a common practice in Iran, therefore we could not consider this as a risk factor in our study. We found no evidence of any other associated risk factors.
Keratosis lichenoides chronica
Authors: Miller Tara D. , Chilukuri Suneel , Bayer‐Garner Ilene B. , Hsu Sylvia
Published: November 2004

Keratosis lichenoides chronica (KLC) is a rare chronic disorder of keratinization, characterized by the progressive development of erythematosquamous plaques and violaceous lichenoid hyperkeratotic papules, nodules and ridges. These lesions are most commonly found in a symmetrical distribution on the trunk and extremities and display a unique linear and/or reticulate pattern. The etiology of KLC remains unknown and the eruptions tend to be refractory to treatment. We describe a case of keratosis lichenoides chronica that improved with systemic retinoids.
p16 expression in psoriatic lesions following therapy with propylthiouracil, an antithyroid thioureylene
Authors: Elias A. N. , Barr R. J. , Nanda V. S.
Published: November 2004

Plaque formation is a characteristic finding in patients with psoriasis and reflects cytokine‐induced keratinocyte proliferation and/or impaired apoptosis of keratinocytes. Antithyroid thioureylenes such as propylthiouracil (PTU) and methimazole (MMI) are effective in the treatment of plaque psoriasis. Following PTU and MMI treatment, proliferative cell nuclear antigen (PCNA) expression is significantly reduced, suggesting that these medications have an antiproliferative effect. p16 is an antiapoptotic protein that is present in relative abundance in psoriatic plaques and is believed to play a potential role in the persistent senescence and impaired apoptosis of the keratinocytes in the plaque. This study examined p16 expression in biopsy samples of eight patients with plaque psoriasis given 300 mg of propylthiouracil in divided doses for 3 months. Despite significant clinical and histological improvement with PTU treatment, p16 expression was essentially unchanged, suggesting that the beneficial effect of PTU in psoriasis is not mediated through a decrease in p16 expression. The effect of PTU on other antiapoptotic proteins such as bcl‐xL remains to be determined.
Surgical pearl: the safety pin as a better alternative to the versatile paper clip comedo extractor
Authors: Mukhtar Muhammed , Sharma Rajeev
Published: November 2004

Acne vulgaris is a very common, chronic inflammatory disease of the pilosebaceous apparatus. The comedo extractor is the instrument primarily used for comedo extraction. There are many types of more costly instruments available, but extraction can be achieved with the help of a modified versatile paper clip and disposable syringes. The disposable syringe is a good option for acne surgery, but a safety pin has been found to be more effective than the clip comedo extractor for extracting the comedo. The safety pin can be regarded as a “two‐in‐one” instrument for piercing the lesion and for extracting the keratinous material from the pilosebaceous canals.
Facial porokeratosis characterized by destructive lesions
Authors: Miranda Sandra Maria Bitencourt , De Miranda João Nestor Rodrigues , De Souza Filho João Basílio
Published: November 2004

Porokeratosis is a rare group of keratinizing diseases. It is inherited as an autosomal dominant disease with variable penetrance, although sporadic cases are often reported. Porokeratosis has as its histological hallmark the typical cornoid lamella. Porokeratosis lesions localized on the face can vary from superficial to destructive in nature. Only 12 cases have been reported in the literature to date. We report one more unusual case of destructive facial porokeratosis.
Dysferlinopathy associated with rigid spine syndrome
Authors: Nagashima Toshiko , Chuma Takayo , Mano Yukio , Goto Yu‐ichi , Hayashi Yukiko K. , Minami Narihiro , Nishino Ichizo , Nonaka Ikuya , Takahashi Toshiaki , Sawa Hirofumi , Aoki Masashi , Nagashima Kazuo
Published: November 2004

Dysferlinopathy and rigid spine syndrome occurring in a 50‐year‐old man is reported. The patient noticed stiffness of knee and ankle joints, which gradually extended to neck, wrist and elbow joints leading to difficulty in anterior flexion. Muscular weakness and wasting of the lower extremities  had  developed  since  age  40,  accompanied  by  a limitation of anterior bending of the spine. Elevated serum CK was noticed. Muscle CT revealed atrophy with moderate fatty replacement of muscles in the neck, shoulder and pelvic girdle, and marked replacement in the para‐vertebral muscles, posterior compartment of hamstrings and calf muscles. Electromyography showed a typical myogenic pattern, and muscle biopsy disclosed dystrophic changes, compatible with limb‐girdle muscular dystrophy 2B. Loss of dysferlin expression was verified by immunohistochemistry, which was confirmed by a mini‐multiplex Western blotting system. Gene analyses of the dysferlin gene disclosed compound heterozygotes for frameshift (G3016 + 1A) and a missense mutation (G3370T). This study might propose some clues to resolve the combination of musular dystrophies and rigid spine syndrome.
Integrating Decentralized Strategy Making and Strategic Planning Processes in Dynamic Environments
Authors: Andersen Torben Juul
Published: November 2004

abstract 

Decentralized post‐bureaucratic organizations are deemed to display superior performance in dynamic environments, but recent evidence indicates that centralized integrative cross‐functional processes may be equally critical. Accordingly, this paper hypothesizes that organizational performance can be ascribed to the simultaneous emphasis on decentralized strategy making and strategic planning processes. This is investigated in a study of 185 manufacturing organizations operating in diverse industries spanning food processing and computer products. The study shows that both decentralized decision structure and planning activities are associated with higher performance in dynamic environments. These findings confirm that effective organizations engage in more complex strategy formation processes that complement the decentralized post‐bureaucratic form with formal mechanisms of rational analyses and operational integration. The paper highlights a need to extend our understanding of the duality between decentralization and planning.
The Development of Corporate Charitable Contributions in the UK: A Stakeholder Analysis
Authors: Brammer Stephen , Millington Andrew
Published: November 2004

abstract 

This paper investigates the determinants of corporate charitable donations within a comparative study of corporate behaviour in two time periods, 1989–90 and 1998–99. The analysis is based on a longitudinal data set that includes over 400 UK listed companies. The determinants of corporate charitable donations are explored within a stakeholder model and the relationship between corporate charitable donations and a set of firm and industry variables is estimated using OLS. Particular emphasis is placed on industry effects and the impact of social and environmental stakeholders. The results highlight a significant change in behaviour between 1989–90 and 1998–99 that may reflect a strategic response by corporate decision‐makers to external concerns over corporate social responsibility. In the early period corporate charitable donations were substantially determined by profits. However, this relationship has weakened during the 1990s as firms have become increasingly responsive to stakeholder influences. The results for the later period emphasize the increasing importance of corporate visibility, and the development of social and environmental influences on corporate charitable contributions.
The Business School ‘Business’: Some Lessons from the US Experience*
Authors: Pfeffer Jeffrey , Fong Christina T.
Published: November 2004

abstract 

US business schools dominate the business school landscape, particularly for the MBA degree. This fact has caused schools in other countries to imitate the US schools as a model for business education. But US business schools face a number of problems, many of them a result of offering a value proposition that primarily emphasizes the career‐enhancing, salary‐increasing aspects of business education as contrasted with the idea of organizational management as a profession to be pursued out of a sense of intrinsic interest or even service. We document some of the problems confronting US business schools and show how many of these arise from a combination of a market‐like orientation to education coupled with an absence of a professional ethos. In this tale, there are some lessons for educational organizations both in the US and elsewhere that are interested in learning from the US experience.
Hypoxia potentiates transforming growth factor‐β expression of hepatocyte during the cirrhotic condition in rat liver
Authors: Jeong Won‐II , Do Sun‐Hee , Yun Hae‐Sun , Song Byoung‐Joon , Kim Seong‐Jin , Kwak Wie‐Jong , Yoo Sung‐Eun , Park Ho‐Yong , Jeong Kyu‐Shik
Published: November 2004

Abstract: Background/Aims: Many studies have reported that hypoxia might be associated with angiogenesis and fibrogenesis, and the level of transforming growth factor‐β1 (TGF‐β1) was increased in fibrotic liver and maximal at cirrhosis. Therefore, we examined the expression of TGF‐β1, phosphorylated‐Smad2/3 (p‐Smad2/3) of the TGF‐β immediate down stream signaling system and hypoxic status during hepatic fibrogenesis.

Methods: Fibrosis of rats was induced by carbon tetrachloride. Collagens were detected with Azan stain. Immunohistochemistry and immunoblotting was used.

Results: TGF‐β1 was mainly produced by hypoxic hepatocytes at cirrhosis although myofibroblasts (MFBs) and macrophages producing TGF‐β1 were decreased. Moreover, distribution of p‐Smad2/3 in hepatocytes was consistent with those of hypoxic hepatocytes regardless of MFBs. Furthermore, in recovery, most MFBs disappeared, whereas positive reactions of p‐Smad2/3 still existed in the hepatocytes of hypoxic areas. Therefore, TGF‐β1 expression in hepatocytes might have been associated with hypoxia.

Conclusions: We put forward the hypothesis that TGF‐β1 is mainly produced by MFBs and macrophages at early and middle stages of fibrotic processes, but it is predominantly released by hypoxic hepatocytes in the last fibrotic stage or cirrhosis.
Evaluation of transcatheter arterial embolization prior to percutaneous tumor ablation in patients with hepatocellular carcinoma: a randomized controlled trial
Authors: Akamatsu Masatoshi , Yoshida Haruhiko , Obi Shuntaro , Sato Shinpei , Koike Yukihiro , Fujishima Tomonori , Tateishi Ryosuke , Imamura Masatoshi , Hamamura Keisuke , Teratani Takuma , Shiina Shuichiro , Ishikawa Takashi , Omata Masao
Published: November 2004

Abstract: Background: Transcatheter arterial embolization (TAE) may reduce the risk of hepatocellular carcinoma (HCC) recurrence when performed before percutaneous tumor ablation (PTA), either percutaneous ethanol injection therapy (PEIT) or radiofrequency ablation (RFA). We conducted a randomized, controlled trial comparing the use of TAE combined with percutaneous ethanol injection therapy (TAE/PEIT) to the use of PEIT only to assess the effects on HCC recurrence and survival. We continued the study after the introduction of RFA and compared TAE combined with RFA (TAE/RFA) with RFA only.

Methods: Between March 1997 and April 2001, 42 HCC patients were enrolled who satisfied the following inclusion criteria: (1) uninodular HCC as determined by angiography under computed tomography, (2) arterial hypervascularity, and (3) no prior history of HCC treatment. Twenty‐two patients were treated with TAE/PTA (PEIT, 12; RFA, 10) and 20 patients with PTA only (PEIT, 14; RFA, 6).

Results: There were four cases of local recurrence in the PTA‐only group and none in the TAE/PTA group (P=0.043). The four patients with local recurrence were treated with PEIT. None of the patients treated with RFA showed local recurrence. The effect of TAE on overall recurrence was not significant (P=0.4179). In the multivariate analysis, prior TAE was not significant for survival (P=0.514).

Conclusions: TAE has a limited use in suppressing local recurrence when performed before PEIT but not before RFA.
Peginterferon α‐2b plus ribavirin compared with interferon α‐2b plus ribavirin for initial treatment of chronic hepatitis C in Saudi patients commonly infected with genotype 4
Authors: Alfaleh F. Z. , Hadad Q. , Khuroo M. S. , Aljumah A. , Algamedi A. , Alashgar H. , Al‐Ahdal M. N. , Mayet I. , Khan M. Q. , Kessie G.
Published: November 2004

Abstract: Aim: Comparing the efficacy of peginterferon α‐2b plus ribavirin with interferon α ‐2b plus ribavirin in Saudi patients with chronic hepatitis C virus (HCV) commonly infected with genotype 4.

Methods: A total of 96 patients with chronic HCV infection were randomly assigned to two treatment groups. Forty‐eight patients received once weekly 100 μg of peginterferon α‐2b plus ribavirin given orally 800 mg/day (peginterferon group). Another 48 patients received thrice weekly 3 million units of interferon α‐2b plus ribavirin 800 mg/day (interferon group). At the end of treatment (48 weeks) and sustained (72 weeks) biochemical and virologic responses were determined.

Results: In the peginterferon group, 70.8% (34/48) patients attained both biochemical and virologic responses at the end of the treatment as against 52.1% (25/48) patients in the interferon group. (P=0.09 for both). Similarly, sustained biochemical and virologic responses in the peginterferon group were attained in 52.1% (25/48) and 43.8% (21/48) patients as against 43.8% (21/48) and 29.2% (14/48) patients in the interferon group, respectively (P=0.54 and 0.20, respectively). The sustained virologic response rates in patients with genotype 4 were 42.9% (12/28) in the peginterferon group and 32.3% (10/31) in the interferon group (P=0.43). Patients in peginterferon group had higher, although statistically not significant adverse reactions.

Conclusions: Saudi patients with chronic HCV attained a higher, although statistically not significant sustained virologic response with pegylated interferon plus ribavirin compared with interferon plus ribavirin.
Lamivudine treatment for acute severe hepatitis B: a pilot study
Authors: Schmilovitz‐Weiss H. , Ben‐Ari Z. , Sikuler E. , Zuckerman E. , Sbeit W. , Ackerman Z. , Safadi R. , Lurie Y. , Rosner G. , Tur‐Kaspa R. , Reshef R.
Published: November 2004

Abstract: Background: Experience with lamivudine treatment of immunocompetent patients with acute hepatitis B is limited.

Aim of study: To evaluate the safety and efficacy of lamivudine for the treatment of acute severe hepatitis B virus (HBV) infection in immunocompetent adults.

Patients and Methods: Fifteen patients (10 men, 5 women, mean age 34.3±7.3 years) with severe acute HBV infection were treated with lamivudine 100 mg daily for 3–6 months, starting 3–12 weeks after onset of infection. Prior to treatment, 5 patients had grade 1–4 encephalopathy; all patients had severe coagulopathy (mean INR was 4.5±6.4), and all patients had evidence of severe hepatocyte lysis (mean alanine aminotransferase 3738±1659 U/L, and mean total serum bilirubin 18±6.8 mg/dl). All patients had evidence of highly replicative HBV (mean HBV DNA 13.5 × 106±11 × 106 copies/ml).

Results: Thirteen patients (86.6%) responded to treatment. Encephalopathy disappeared within 3 days of treatment and coagulopathy improved within 1 week. Serum HBV DNA was undetectable (by polymerase chain reaction) within 4 weeks, and serum liver enzyme levels normalized within 8 weeks. Two patients in whom lamivudine therapy was delayed developed fulminant hepatitis and underwent urgent liver transplantation. (One died of vascular complications 1 month later). The 11 patients who were serum HBeAg‐positive before treatment seroconverted, and HBeAb developed within 12 weeks in 9 of them; HBsAg was undetectable in all 11 tested patients, and protective titer of HBsAb developed within 12–16 weeks in 9 of them. Therapy was well tolerated in all cases.

Conclusions: These data indicate that lamivudine induces a prompt clinical, biochemical, serological and virological response in immunocompetent patients with de novo HBV infection. Lamivudine may prevent the progression of severe acute disease to fulminant or chronic hepatitis and should be considered for use in selected patients. A large randomized controlled, double‐blind prospective study is needed.
Volume sensitivity of the bestrophin family of chloride channels
Authors: Fischmeister Rodolphe , Hartzell H. Criss
Published: November 2004

Bestrophins are a newly identified family of Cl− channels. Mutations in the founding member of the family, human bestrophin‐1 (hBest1), are responsible for a form of early onset macular degeneration called Best vitelliform macular dystrophy. The link between dysfunction of  hBest1 and macular degeneration remains unknown. Because retinal pigmented epithelium (RPE) cells may be subjected to varying osmotic pressure due to light‐dependent changes in the ionic composition of the subretinal space and because RPE cells may undergo large volume changes during phagocytosis of shed photoreceptor discs, we investigated whether bestrophin currents were affected by cell volume. When hBest1 and mBest2 were overexpressed in HEK 293, HeLa, and ARPE‐19 cells, a new Ca2+‐activated Cl− current appeared. This current was very sensitive to cell volume. A 20% increase in extracellular osmolarity caused cell shrinkage and a ∼70–80% reduction in bestrophin current. Decreases in extracellular osmolarity increased the bestrophin currents slightly, but this was difficult to quantify due to simultaneous activation of endogenous volume‐regulated anion channel (VRAC) current. To determine whether a similar current was present in mouse RPE cells, the effect of hyperosmotic solutions on isolated mouse RPE cells was examined. Mouse RPE cells exhibited an endogenous Cl− current that resembled the expressed hBest1 in that it was decreased by hypertonic solution. We conclude that bestrophins are volume sensitive and that they could play a novel role in cell volume regulation of RPE cells.
Rise and Fall of the Beringian Steppe Bison
Authors: Shapiro Beth , Drummond Alexei J. , Rambaut Andrew , Wilson Michael C. , Matheus Paul E. , Sher Andrei V. , Pybus Oliver G. , Gilbert M. Thomas P. , Barnes Ian , Binladen Jonas , Willerslev Eske , Hansen Anders J. , Baryshnikov Gennady F. , Burns James A. , Davydov Sergei , Driver Jonathan C. , Froese Duane G. , Harington C. Richard , Keddie Grant , Kosintsev Pavel , Kunz Michael L. , Martin Larry D. , Stephenson Robert O. , Storer John , Tedford Richard , Zimov Sergei , Cooper Alan
Published: November 2004

The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been attributed to the depredations of humans; here we present genetic evidence that questions this assumption. We used ancient DNA and Bayesian techniques to reconstruct a detailed genetic history of bison throughout the late Pleistocene and Holocene epochs. Our analyses depict a large diverse population living throughout Beringia until around 37,000 years before the present, when the population's genetic diversity began to decline dramatically. The timing of this decline correlates with environmental changes associated with the onset of the last glacial cycle, whereas archaeological evidence does not support the presence of large populations of humans in Eastern Beringia until more than 15,000 years later.
Stokes Drag on a Sphere in a Nematic Liquid Crystal
Authors: Loudet J. C. , Hanusse P. , Poulin P.
Published: November 2004

The Stokes-Einstein relation relates the diffusion coefficient of a spherical Brownian particle in a viscous fluid to its friction coefficient. For a particle suspended in anisotropic liquid, theory predicts that the drag coefficient should also be anisotropic. Using video microscopy coupled with particle tracking routines, the Brownian fluctuations of micrometer-sized particles were analyzed to yield a quantitative measurement of the diffusion coefficients parallel and perpendicular to the nematic director. The experimental values agree quite well with recent numerical calculations that take into account the distortions of the director field in the vicinity of the particles.
Three-Dimensional Hydrogen Microscopy in Diamond
Authors: Reichart P. , Datzmann G. , Hauptner A. , Hertenberger R. , Wild C. , Dollinger G.
Published: November 2004

A microprobe of protons with an energy of 17 million electron volts is used to quantitatively image three-dimensional hydrogen distributions at a lateral resolution better than 1 micrometer with high sensitivity. Hydrogen images of a <110>-textured undoped polycrystalline diamond film show that most of the hydrogen is located at grain boundaries. The average amount of hydrogen atoms along the grain boundaries is (8.1 ± 1.5) × 10
14
per square centimeter, corresponding to about a third of a monolayer. The hydrogen content within the grain is below the experimental sensitivity of 1.4 × 10
16
atoms per cubic centimeter (0.08 atomic parts per million). The data prove a low hydrogen content within chemical vapor deposition–grown diamond and the importance of hydrogen at grain boundaries, for example, with respect to electronic properties of polycrystalline diamond.
Seismic Anisotropy Beneath Ruapehu Volcano: A Possible Eruption Forecasting Tool
Authors: Gerst Alexander , Savage Martha K.
Published: November 2004

The orientation of crustal seismic anisotropy changed at least twice by up to 80° because of volcanic eruptions at Ruapehu Volcano, New Zealand. These changes provide the basis for a new monitoring technique and possibly for future midterm eruption forecasting at volcanoes. The fast anisotropic direction was measured during three seismometer deployments in 1994, 1998, and 2002, providing an in situ measurement of the stress in the crust under the volcano. The stress direction changed because of an eruption in 1995–1996. Our 2002 measurements revealed a partial return to the pre-eruption stress state. These changes were probably caused by repeated filling and depressurizing of a magmatic dike system.
The Ethylene Signaling Pathway
Authors: Alonso Jose M. , Stepanova Anna N.
Published: November 2004

Plants use a structurally very simple gas molecule, the hydrocarbon ethylene, to modulate various developmental programs and coordinate responses to a multitude of external stress factors. How this simple molecule generates such a diverse array of effects has been the subject of intense research for the past two decades. A fascinating signaling pathway, with classical as well as novel plant-specific signaling elements, is emerging from these studies. We describe the four main modules that constitute this signaling pathway: a phosphotransfer relay, an EIN2-based unit, a ubiquitin-mediated protein degradation component, and a transcriptional cascade. The canonical and
Arabidopsis
ethylene signaling pathways in the Signal Transduction Knowledge Environment Connections Maps provide a complete panoramic view of these signaling events in plants.
CROSS SECTIONS FOR L X-RAY PRODUCTION IN Ba, La AND Ce BY 1 TO 3.5 MeV PROTONS
Authors: KADOM-AL-NEAMI A. , AL-NEAMI A. , BORDAS M. , LARCHER J. , HEITZ C.
Published: November 2004

Ba, La and Ce L X-ray production cross sections by 1 to 3.5 MeV protons have been measured for thin and thick targets. The experimental values are compared to those calculated from theoretical L subshell ionization cross sections and to experimental values determined by other authors for elements 50 to 92.
INVESTIGATING AN AUTOMATON OF "CLASS 4"
Authors: GALLAS JASON A. C. , HERRMANN HANS J.
Published: November 2004

We study the one-dimensional totalistic rule 20 with five cells per neighborhood. We find two transients both characterized by finite correlation lengths. The first transient of about 100 time-steps terminates in the glider phase. Collisions of gliders determine the second transient of about 30,000 time-steps. The final state has a finite magnetization and is indistinguishable from class 2 behaviour.
PARALLEL COMPUTING: SOME ACTIVITIES IN HIGH ENERGY PHYSICS
Authors: WILLERS IAN
Published: November 2004

This paper examines some activities in High Energy Physics that utilise parallel computing. The topic includes all computing from the proposed SIMD front end detectors, the farming applications, high-powered RISC processors and the large machines in the computer centers. We start by looking at the motivation behind using parallelism for general purpose computing. The developments around farming are then described from its simplest form to the more complex system in Fermilab. Finally, there is a list of some developments that are happening close to the experiments.
INSTANTONS AND EMC-EFFECT FOR SPIN-DEPENDENT FUNCTION
Authors: DOROKHOV A.E. , KOCHELEV N.I.
Published: November 2004

It is shown that the polarization contribution of the instanton vacuum of QCD gives 70% contribution to the nucleon helicity. However, it is cancelled by the contribution of sea quarks which are polarized against the nucleon spin.
LIMITS SET BY ANALYTICITY AND CURRENT ALGEBRA ON THE EXISTENCE OF A HEAVY NUCLEON
Authors: MASPERI LUIS , VIOLINI GALILEO
Published: November 2004

We estimate through the analysis of dispersion relations and current algebra sum rules that the experimentally searched excited state of nucleon with mass below pion-nucleon threshold must have a coupling one order of magnitude smaller than the normal pion-nucleon one [Formula: see text] as an upper bound.
ANOMALY FREEDOM THROUGH LEPTO-QUARK MATTER
Authors: RAJPOOT SUBHASH
Published: November 2004

Lepto-quark matter represents new fermionic matter that carries quark as well as lepton numbers. An extension of the standard model with three families of conventional quarks and leptons is presented in which freedom from anomalies is secured through the presence of lepto-quark matter representations. The gauge symmetry of the model is SU(2)L×U(1)q×U(1)l where U(1)q and U(1)l refer to distinct hypercharge sources for the quarks and the leptons.
q-ANALOGUE OF BOSON COMMUTATOR AND THE QUANTUM GROUPS SUq(2) AND SUq(1, 1)
Authors: UI HARUO , AIZAWA N.
Published: November 2004

We propose a defining set of commutation relations to a q-analogue of boson operator; [Formula: see text], [Formula: see text] and [N, aq]=−aq, which contracts to the Heisenberg algebra of boson operators in the limit of q=1. Here, N is the number operator, [N]q being its q-analogue operator. By making use of this set, we construct a new realization of the “noncompact” quantum group SUq(1, 1) in addition to that of the SUq(2) recently proposed by Biedenharn. The explicit form of the number operator is given in terms of aq and [Formula: see text] and its positive definiteness is proved. A uniqueness of our commutators is also discussed. It is shown that the quantum group SUq(2) appears as a true symmetry group of a q-analogue of the two-dimensional harmonic oscillator and the SUq(1, 1) as its dynamical group.
NEW P-ADIC STRING AMPLITUDES
Authors: MARSHAKOV A.V. , ZABRODIN A.V.
Published: November 2004

It is shown that the branching multiplicative characters (corresponding to certain quadratic extensions) of the p-adic number fields can be used to construct the tree amplitudes in the p-adic string theory. In particular, the p-adic analogues of the tachyon amplitudes in the Neveu-Schwarz sector of the superstring and the p-adic amplitudes of the emission of the massless vector particles for the bosonic non-archimedean string are obtained.
SOLITONS FROM SUPERSYMMETRY
Authors: WANG QINMOU , SUKHATME UDAY P. , KEUNG WAI-YEE , IMBO TOM D.
Published: November 2004

Supersymmetry transformations constitute a new, powerful technique of generating families of isospectral potentials. We show that isospectral families of reflectionless potentials provide surprisingly simple expressions for the pure multi-soliton solutions of the KdV and other nonlinear evolution equations.
A SCHEME FOR COMPLEMENTARITY AND HIGGS PHASE ANALYSES
Authors: LU GONGRU , YOUNG BING-LIN , ZHANG XINMIN
Published: November 2004

We introduce a simple dynamical scheme to supplement the complementarity and Higgs phase analyses of composite models with semi-simple metacolor groups. The critical couplings which signal the dynamical breakdown of the various simple groups contained in the metacolor semi-simple group determine the order of appearance of the condensates of the simple groups. Together with the Higgs phase analysis, it helps to determine the global symmetry of the fermion composite. The global symmetry group will eventually be gauged to form the low energy dynamical symmetry group of the composite.
CLASSICAL VORTEX SOLUTIONS IN THREE-DIMENSIONAL SUPERSYMMETRIC ABELIAN-HIGGS MODEL
Authors: DE MELLO E.R. BEZERRA
Published: November 2004

Classical vortex solutions in a three-dimensional supersymmetric Abelian-Higgs model are presented. A cylindrically symmetric ansatz for the bosonic and fermionic fields is used, and the asymptotic behavior for these fields are also obtained. No electric charge for this model is found, although the temporal component for the bosonic gauge field is not zero. Finally, after we have integrated over all the fermionic degree of freedom, a purely bosonic action is obtained.
THE β-FUNCTION IN 4-DIMENSIONAL TOPOLOGICAL YANG-MILLS THEORY
Authors: MADSEN JENS OLE
Published: November 2004

We calculate the β-function in Witten's 4-dimensional topological Yang-Mills theory, using the heat kernel method.
ON THE W BOSON ANOMALOUS MAGNETIC MOMENT
Authors: SAMUEL KENNETH B. , SAMUEL MARK A. , LI G.
Published: November 2004

The anomalous magnetic moment of the W boson is computed as a function of the unknown Higgs mass (MH) and the unknown top quark mass (mt). The results for (g − 2)w are as follows [Formula: see text]
TWISTED CHARACTERS AND PARTITION FUNCTIONS IN EXTENDED VIRASORO ALGEBRAS
Authors: ZHENG HAI BIN , HO-KIM Q.
Published: November 2004

The characters of the degenerate representations of the extended Virasoro algebras associated with the 2-twisted Lie algebras [Formula: see text], [Formula: see text] and [Formula: see text] are derived and their modular transformation properties examined. Modular invariant partition functions for [Formula: see text] and [Formula: see text][Formula: see text] are presented.
OCTUPOLE DEFORMATION IN 221Fr; E1 TRANSITION RATES
Authors: LIANG C.F. , PÉGHAIRE A. , SHELINE R.K.
Published: November 2004

Experimental data following the alpha decay of 225 Ac are interpreted in terms of a spectroscopy in 221 Fr consistent with octupole deformation. However, the measured E1 transition probabilities suggest that the low lying bands in 221 Fr are considerably more mixed than in nuclei with slightly higher mass number. It is suggested that this mixing of states in 221 Fr is indicative of the partial collapse of Nilsson-like orbitals into more degenerate shell model orbitals.
SUPERSYMMETRY AND CONSERVATION LAWS IN THE KdV SYSTEM
Authors: ROY PRODYOT KUMAR , LAHIRI ANURADHA , BAGCHI BIJAN
Published: November 2004

The role of supersymmetry in the KdV-MKdV hierarchy of conservation laws is examined. Among all the fifth order evolution equations, the Lax equation turns out to be the only one which is mapped onto its modified partner through the pair of supersymmetric transformations.