bluuebunny/crossref_metadata_2025 huggingface dataset:
The morality of socioscientific issues: Construal and resolution of genetic engineering dilemmas
Authors: Sadler Troy D. , Zeidler Dana L.
Published: December 2003

The ability to negotiate and resolve socioscientific issues has been posited as integral components of scientific literacy. Although philosophers and science educators have argued that socioscientific issues inherently involve moral and ethical considerations, the ultimate arbiters of morality are individual decision‐makers. This study explored the extent to which college students construe genetic engineering issues as moral problems. Twenty college students participated in interviews designed to elicit their ideas, reactions, and feelings regarding a series of gene therapy and cloning scenarios. Qualitative analyses revealed that moral considerations were significant influences on decision‐making, indicating a tendency for students to construe genetic engineering issues as moral problems. Students engaged in moral reasoning based on utilitarian analyses of consequences as well as the application of principles. Issue construal was also influenced by affective features such as emotion and intuition. In addition to moral considerations, a series of other factors emerged as important dimensions of socioscientific decision‐making. These factors included personal experiences, family biases, background knowledge, and the impact of popular culture. The implications for classroom science instruction and future research are discussed. © 2003 Wiley Periodicals, Inc. Sci Ed 88:4–27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10101
The laboratory in science education: Foundations for the twenty‐first century
Authors: Hofstein Avi , Lunetta Vincent N.
Published: December 2003

The laboratory has been given a central and distinctive role in science education, and science educators have suggested that rich benefits in learning accrue from using laboratory activities. Twenty years have been elapsed since we published a frequently cited, critical review of the research on the school science laboratory (Hofstein & Lunetta, Rev. Educ. Res. 52(2), 201–217, 1982). Twenty years later, we are living in an era of dramatic new technology resources and new standards in science education in which learning by inquiry has been given renewed central status. Methodologies for research and assessment that have developed in the last 20 years can help researchers seeking to understand how science laboratory resources are used, how students' work in the laboratory is assessed, and how science laboratory activities can be used by teachers to enhance intended learning outcomes. In that context, we take another look at the school laboratory in the light of contemporary practices and scholarship. This analysis examines scholarship that has emerged in the past 20 years in the context of earlier scholarship, contemporary goals for science learning, current models of how students construct knowledge, and information about how teachers and students engage in science laboratory activities. © 2003 Wiley Periodicals, Inc. Sci Ed 88:28–54, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10106
Thomas Kuhn's impact on science education: What lessons can be learned?
Authors: Matthews Michael R.
Published: December 2003

Thomas Kuhn has had an impact in all academic fields. In science education, Kuhnian themes are especially noticeable in conceptual change research, constructivist theorizing, and multicultural education debates. Unfortunately the influence is frequently compromised by researchers having a limited understanding of Kuhn's original ideas, little exposure to the tradition of philosophical opposition to Kuhn's theories, and minimal appreciation of how Kuhn progressively qualified his initial “irrationalist'' views of scientific development. One lesson to be learnt is that the science education community should more seriously and effectively engage with on‐going debates and analysis in the history and philosophy of science. This is the same lesson that was learnt from the science education community's wholesale embrace of logical empiricism during the 1950s and 1960s. Another lesson is that there are powerful disciplinary, institutional, and subcultural barriers that mitigate against science educators seriously engaging with historical and philosophical scholarship. © 2003 Wiley Periodicals, Inc. Sci Ed 88:90–118, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10111
Images of nature in greek primary school textbooks
Authors: Korfiatis Kostas J. , Stamou Anastasia G. , Paraskevopoulos Stephanos
Published: December 2003

In this article, the environmental content of the textbooks used for the teaching of natural sciences in Greek primary schools was examined. Specifically, by employing the method of content analysis, both representational (metaphors, depictions, values, etc.) and cognitive (ecological concepts) elements, building images of nature, and shaping our opinion and attitudes towards the environment were examined. The results of the analysis revealed that a coherent whole was produced, where nature was in a condition of oscillating balance, with everything being connected with something else, and humans having absolute control over a nature whose only value was its usefulness as a resource for food and raw material. However, seen qualitatively, the edifice included many contradictory elements and inconsistencies, which, having evolved out of a specific context, might spread confusion and deprive pupils from critical thinking. On the other hand, the image of nature dominating disagreed with both a standpoint advocating an equal relationship between humans and nature and with that supporting a relationship of stewardship and care for nature, while it failed to provide students with proper and sufficient environmental knowledge. © 2003 Wiley Periodicals, Inc. Sci Ed 88:72–89, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10133
A systematic assessment of the empirical support for transaction cost economics
Authors: David Robert J. , Han Shin‐Kap
Published: December 2003

Transaction cost economics (TCE) is one of the leading perspectives in management and organizational studies, yet debate continues regarding its empirical support. In this paper, we take stock of the large body of extant research and provide a systematic assessment of empirical evidence. In all, 308 statistical tests from 63 articles, selected according to a set of clear criteria, were examined across various dimensions. We assess not only the level of empirical support for the theory, but also the degree of paradigm consensus present in the empirical literature. Our analysis shows that results are mixed: while we found support in some areas (e.g., with regard to asset specificity), we also found considerable disagreement on how to operationalize some of TCE's central constructs and propositions, and relatively low levels of empirical support in other core areas (e.g., surrounding uncertainty and performance). We conclude that a more thorough empirical grounding of the theory's foundation is crucial to its future development, and offer several strategies for doing this. Copyright © 2003 John Wiley & Sons, Ltd.
Strategic positioning, human capital, and performance in service organizations: a customer interaction approach
Authors: Skaggs Bruce C. , Youndt Mark
Published: December 2003

This study employs a customer interaction approach to examine how service organizations' strategic positioning relates to their human capital, and how the interaction between strategic positioning and human capital impacts organizational performance. Results from 234 service organizations in 96 different industries indicate very strong relationships between strategic positioning choices and human capital. We also find that certain combinations of strategic positioning and human capital result in superior performance. Copyright © 2003 John Wiley & Sons, Ltd.
Guaranteed inconsistency avoidance during software evolution
Authors: Gallagher Keith , Harman Mark , Danicic Sebastian
Published: December 2003

The attempt to design and integrate consistent changes to an existing system is the essence of software maintenance. Software developers also confront similar problems: there are changes during testing and the release of new system builds. Whether in development or maintenance, changes to evolving systems must be made consistently; that is, without damaging correct computations. It is difficult for the programmer to ascertain the complete effect of a code change; the programmer may make a change to a program that is syntactically and semantically legal, but which has ripples into the parts of the program that were intended to remain unchanged.

Using the standard denotational semantics for procedural programming languages, this paper formalizes decomposition slicing, which identifies interferences between software components and isolates the components to be changed. We enumerate the conditions for changing one component in ways that will guarantee that changes to it will not interact inconsistently and prove that changes made under these conditions are sound. Thus, the programmer can then execute changes secure in the knowledge that the semantics of the new system are guaranteed to be consistent with the projection of the semantics of the original for which it behaved correctly. Validating that the changes do not interfere not only guarantees consistency with respect to previous unchanging behaviors, but can also be achieved with a complexity proportional to the size of the change to be made. Copyright © 2003 John Wiley & Sons, Ltd.
Automated elicitation of inclusion dependencies from the source code for database transactions
Authors: Tan Hee Beng Kuan , Zhao Yuan
Published: December 2003

Inclusion dependency is an important data dependency in databases. Enforcement of data dependencies is a major component in any database application. Due to the nature of software development and maintenance and the limitation of database management systems (DBMSs) in handling the enforcement of inclusion dependency, many inclusion dependencies are enforced not through the DBMS, but through the transactions that update the database. It is very difficult and time consuming to elicit (to extract or to recover) inclusion dependencies from transactions manually during the reengineering, verification and maintenance of database applications. With the use of program analysis, this paper proposes a novel approach for the automated elicitation of inclusion dependencies from the source code of transactions that update the database. The approach is based on detecting program path patterns for enforcing inclusion dependency. Copyright © 2003 John Wiley & Sons, Ltd.
New modules for PCR‐based gene targeting in Candida albicans: rapid and efficient gene targeting using 100 bp of flanking homology region
Authors: Gola Susanne , Martin Ronny , Walther Andrea , Dünkler Alexander , Wendland Jürgen
Published: December 2003

The use of PCR‐based techniques for directed gene alterations has become a standard tool in Saccharomyces cerevisiae. In our efforts to increase the speed of functional analysis of Candida albicans genes, we constructed a modular system of plasmid vectors and successfully applied PCR‐amplified functional analysis (FA)‐cassettes in the transformation of C. albicans. These cassettes facilitate: (a) gene disruptions; (b) tagging of 3′‐ends of genes with green fluorescent protein (GFP); and (c) replacements of endogenous promoters to achieve regulated expression. The modules consists of a core of three selectable marker genes, CaURA3, CaHIS1 and CaARG4. Modules for C‐terminal GFP‐tagging were generated by adding GFP‐sequences flanked at the 5′‐end by a (Gly‐Ala)3‐linker and at the 3′‐end by the S. cerevisiae URA3‐terminator to these selection markers. Promoter exchange modules consist of the respective marker genes followed by the regulatable CaMAL2 or CaMET3 promoters at their 3′‐ends. In order to ensure a reliably high rate of homologous gene targeting, the flanking homology regions required a size of 100 bp of gene‐specific sequences, which were provided with the oligonucleotide primers. The use of shorter flanking homology regions produced unsatisfactory results with C. albicans strain BWP17. With these new modules only a minimal set of primers is required to achieve the functional analysis of C. albicans genes and, therefore, provides a basic tool to increase the number of functionally characterized C. albicans genes of this human pathogen in the near future. Copyright © 2003 John Wiley & Sons, Ltd.
Genome‐wide monitoring of wine yeast gene expression during alcoholic fermentation
Authors: Rossignol Tristan , Dulau Laurent , Julien Anne , Blondin Bruno
Published: December 2003

The transcriptome of a wine yeast was monitored throughout an alcoholic fermentation under conditions mimicking an enological environment. Major changes in gene expression occurred during fermentation, affecting more than 2000 genes, as the yeast adapted to changing nutritional, environmental and physiological conditions. The genes of many pathways are regulated in a highly coordinated manner, and genes involved in the key metabolic pathways of fermentation are strongly expressed. We showed that, during fermentation of a synthetic medium mimicking a natural must in which growth arrest was caused by nitrogen exhaustion, entry into the stationary phase triggered major transcriptional reprogramming. Many TOR target genes involved in nitrogen utilization or other functions are induced at this stage, suggesting that this signalling pathway plays a critical role in changes in gene expression in response to nitrogen depletion. Entry into stationary phase is a key physiological event and is followed by a general stress response. The superimposition of multiple stresses, including starvation and ethanol stress, gives rise to a unique stress response, involving hundreds of genes encoding proteins involved in various cellular processes, many of unknown function. Copyright © 2003 John Wiley & Sons, Ltd.
Purification, characterization and functional cloning of inositol oxygenase from Cryptococcus
Authors: Kanter Ulrike , Becker Michael , Friauf Eckhard , Tenhaken Raimund
Published: December 2003

The enzyme inositol oxygenase (myo‐inositol : oxygen oxidoreductase; E.C. 1.13.99.1) is a monooxygenase that converts inositol into glucuronic acid in the presence of molecular oxygen. This enzyme is integrated into a pathway leading to either degradation and energy production or the biosynthesis of precursors for polysaccharides. The enzyme was purified from the yeast Cryptococcus lactativorus by a five‐step chromatography procedure. The purified enzyme shows a molecular mass of 37 kDa on SDS–PAGE, similar to the estimation of the size of the native enzyme determined by size exclusion chromatography. Peptides of the inositol oxygenase protein derived from a tryptic digest were sequenced de novo by nanoelectrospray tandem mass spectrometry. Using degenerate oligonucleotides, the corresponding gene was cloned from first strand cDNA. The open reading frame encodes a 315 amino acid polypeptide with a predicted molecular mass of 36.9 kDa. Inositol oxygenase is a single copy gene in C. lactativorus. It has close homologues in other fungi such as Cryptococcus neoformans and Neurospora crassa. Biochemical characterization of the enzyme showed a pH optimum of 6–6.5 and a temperature optimum of 30 °C. Myo‐inositol is the only accepted substrate with a Km of ca. 5 mM. The enzyme contains a Fe‐centre but the enzyme activity is resistant to KCN. Copyright © 2003 John Wiley & Sons, Ltd.
Role of Tea1p, Tea3p and Pom1p in the determination of cell ends in Schizosaccharomyces pombe
Authors: Niccoli Teresa , Arellano Manuel , Nurse Paul
Published: December 2003

Schizosaccharomyces pombe cells are rod‐shaped and grow along a single axis from their two ends. Microtubules extend from the cell centre terminating at the cell ends. The ERM(ezrin/radixin/moesin)‐like proteins Tea1p and Tea3p, and the Dyrk‐like kinase Pom1p are cell end markers involved in the regulation of growth and microtubular dynamics at the cell ends. We have analysed the relative contribution of these three proteins to the determination of cell ends as sites both for cell growth and for microtubular termination. Pom1Δ, in combination with Tea1Δ or Tea3Δ, has the greatest difficulty in relocalizing actin to the cell ends following actin depolymerization and generates the most defective growth pattern. Tea1Δ, in combination with Pom1Δ or Tea3Δ, displays the highest number of microtubules bending round the cell ends. Tea1ΔPom1Δ, which has the most defective growth pattern and microtubules, also displays the highest number of branched cells. We show that Tea1p, Tea3p and Pom1p all contribute, to different extents, to the determination of cell ends, as sites for both cell growth and microtubular termination. We also show that the fission yeast cell relies on both the positioning of landmarks and a properly organized microtubule cytoskeleton to direct cell growth. Copyright © 2003 John Wiley & Sons, Ltd.
Neural network solution for temperature profile retrieval from infrared spectra with high spectral resolution
Authors: Gribanov K.G. , Zakharov V.I.
Published: December 2003

A method based on artificial neural network for atmospheric temperature profile retrieval from spectra measured by nadir viewing high resolution Fourier transform spectrometers is presented. Very fast retrieval of temperature profile is approached. Impact of instrument noise on the retrieval results is considered. Copyright © 2003 Royal Meteorological Society. Published by Elsevier Ltd. All rights reserved.
Pharmacological treatment in patients with heart failure: patients knowledge and occurrence of polypharmacy, alternative medicine and immunizations
Authors: Martínez‐Sellés Manuel , Robles José A. García , Muñoz Roberto , Serrano José A. , Frades Elisa , Muñoa Marta Domínguez , Almendral Jesús
Published: December 2003

Aims:

To evaluate in patients with heart failure (HF) due to systolic dysfunction the occurrence of polypharmacy, alternative medicine, immunization against influenza, and patients’ knowledge about their medication.

Methods and results:

Sixty‐five patients, 49 men, mean age 60.5±12.0 years answered a confidential questionnaire during 2002. Polypharmacy was frequent, 48 (74%) were taking six or more pills per day and 18 (28%) 11 or more. Fifteen patients (23%) used over‐the‐counter analgesics. Eight patients (12%) used alternative medicine [five women (31%) vs. three men (6%), P=0.02]. Forty‐four patients (68%) received immunization against influenza (18 patients <65 years (54%) vs. 25 patients ≥65 years (79%), P=0.03). Half the patients knew that beta‐blockers and vasodilators decreased blood pressure, 31 patients receiving diuretics (88%) knew that this drugs help to eliminate liquids, 12 patients (38%) recognized this effect with low dose spironolactone and 23% or less with other drugs. Only 12 patients (42%) treated with acenocoumarol and 13 of those treated with aspirin (32%) recognized the action of these drugs.

Conclusion:

Patients with HF and systolic dysfunction have a poor knowledge about the medication they receive. Polypharmacy, over‐the‐counter, homeopathic and alternative medicine use is frequent whereas the rate of immunization against influenza is low.
Second trimester choroid plexus cysts and trisomy 18
Authors: Sahinoglu Z. , Uludogan M. , Sayar C. , Turkover B. , Toksoy G.
Published: December 2003

Objectives: In this study, the aims were to reveal the incidence of isolated choroid plexus cyst in our population, and to discuss the accuracy of distinguishing either an isolated or non‐isolated choroid plexus cyst. Methods: The study population was consisted of 10 594 pregnant women. The patients with choroid plexus cysts were classified into two groups: isolated and non‐isolated. Detailed ultrasonographic examination and genetic counseling were performed and triple screening test was ordered. The incidence, sensitivity, specificity, false‐positive rate and likelihood ratio of cases with isolated choroid plexus cyst for trisomy 18 were determined. Results: Choroid plexus cysts were identified in 109 patients (109/10 594; 1.02%). In 102 patients isolated choroid plexus cysts, and in seven patients additional fetal anomalies supporting trisomy 18 were detected. Trisomy 18 was detected in four patients, and one of them had isolated choroid plexus cyst. The likelihood ratio in cases of isolated choroid plexus cysts for trisomy 18 was 9.51 (95% confidence interval, 0.2–41). Conclusions: According to the study the individual risk for trisomy 18 in isolated choroid plexus cyst should be calculated by using the likelihood ratio. These data allows the physician to express the individual risk of trisomy 18 and permits more accurate genetic counseling.
Polymorphism p53 codon‐72 and invasive cervical cancer: a meta‐analysis
Authors: Jee S.H. , Won S.Y. , Yun J.E. , Lee J.E. , Park J.S. , Ji S.S.
Published: December 2003

Objectives: Although some studies have reported that the arginine isoform on codon 72 of p53 increases the susceptibility to invasive cervical cancer, such data remain controversial. The objective of this study was to quantitatively summarize the evidence for such a relationship. Methods: Our data sources consisted of a MEDLINE search of the literature published before December 2002, bibliography review, and expert consultation. Thirty‐seven studies met the inclusion criteria. Information on sample size, study design, Hardy–Weinberg equilibrium, and method of genotype determination was abstracted by two reviewers using a standardized protocol. The overall odds ratio (OR) of the p53 gene on invasive cervical cancer was estimated using the Mantel–Haenzel method. Results: The overall OR (95% confidence interval) for cervical cancer among those with the homozygous mutant (Arg/Arg) was 1.2 (1.1–1.3, P=0.001) compared with those with the heterozygous mutant (Arg/Pro). By a cellular type of cervical cancer, the overall OR among those with Arg/Arg was statistically significant in adenocarcinomas (1.7, 1.1–2.6, P=0.024), but not in squamous cell carcinomas (1.1, 0.9–1.2, P=0.960), compared with Pro/Pro. Compared with Arg/Pro, the OR among those with Arg/Arg was statistically significant in HPV types 16 (1,5, 1.2–2.0, P=0.002). Conclusions: Overall, the p53 gene was associated with increased risk for invasive cervical cancer. However, the risk varied by country, cellular, and HPV type.
Colposacrosuspension for severe genital prolapse
Authors: Cronjé H.S.
Published: December 2003

Objective: A descriptive study of 140 patients with severe genital prolapse managed by colposacrosuspension with mesh interposition and a modified Burch colposuspension. Methods: A laparotomy was performed with mobilization of the rectum and exploration of the rectovaginal septum. Vaginally, a longitudinal incision was made in the posterior vaginal wall which was completely separated from the rectum. A perineal repair was done, whereafter a strip of Vypro® (Johnson & Johnson, Brussels, Belgium) mesh was inserted from the perineum to the sacrum at S1. It was fixated to the perineum and vagina while the rectum was elevated and attached to the mesh. Where a perineal repair was deemed not necessary, the mesh extended from the mid‐vagina to the sacrum. A second mesh strip was placed anteriorly of the vagina, covering the upper third of the vagina and extending to the sacrum. After closure of the pelvic peritoneum, covering the mesh, a modified Burch colposuspension was performed. Follow‐up was done at 6 weeks, 6 months and yearly thereafter. Results: The median age was 61 years with a median parity of 3. All patients presented with grade 2 (extending to the vaginal introitus) or 3 (outside the vaginal introitus) prolapse. Approximately one‐third had urinary incontinence and a similar proportion complained of difficulty in defecation. All the patients underwent colposacrosuspension with the mesh extending to the perineum in 67% of the patients. A Burch colposuspension was performed in 79% of the women. Postoperatively, 97% of the patients were followed for 1–29 months with a median of 8.5 months (mean 10.2 months). Recurrent prolapse, grade 2 or 3, developed in 11 patients (8%) and 17 patients (12%) developed urinary incontinence, needing a transvaginal tape procedure. Removal of the mesh was necessary in one patient (0.7%). Conclusion: Colposacrosuspension for severe genital prolapse delivered satisfactory short‐term results. It is, however, a major surgical procedure and elderly or compromised patients may require less invasive procedures.
Human papillomavirus infection and cervical ectopy
Authors: Rocha‐Zavaleta L. , Yescas G. , Cruz R.M. , Cruz‐Talonia F.
Published: December 2003

Objectives: To investigate the prevalence of human papillomavirus (HPV), and HPV type 16 (HPV16) infection in cervical ectopy, and the presence of anti‐HPV16 secretory IgA (sIgA) antibodies. Methods: DNA from patients with cervical ectopy (n=218), HPV‐associated lesions (n=111), and controls without evidence of cervical ectopy or HPV infection (n=93) were analyzed by PCR for the presence of HPV and HPV16. The presence of mucosal sIgA antibodies against HPV16 capsid antigens (VLP) was assayed in cervical mucus by ELISA. Results: Prevalence of HPV DNA was higher in cervical ectopy than in controls (P=0.04; OR=2.06; 95% CI 0.99–4.33). HPV16 was 6.3 times more prevalent in cervical ectopy than in controls. Anti‐HPV16 sIgA were detected more frequently in cervical ectopy patients than in controls (P=0.0004). Conclusions: Cervical ectopy correlates with HPV infection. HPV16 is highly prevalent in cervical ectopy. sIgA antibodies against HPV16 capsids are generated in patients with cervical ectopy.
Stimulation of bone cell differentiation by low‐intensity ultrasound—a histomorphometric in vitro study
Authors: Korstjens C. M. , Nolte P. A. , Burger E. H. , Albers G. H. R. , Semeins C. M. , Aartman I. H. A. , Goei S. W. , Klein‐Nulend J.
Published: December 2003

Several investigations have established a stimulatory effect of low‐intensity ultrasound treatment on osteogenesis and fracture healing. The objective of this study was to examine whether the stimulatory effect of low‐intensity ultrasound results in increased bone cell activity and/or proliferation.

Twenty‐four paired triplets of metatarsal bone rudiments of twelve 17‐days‐old fetal mice were dissected and divided into two groups. One group of bone rudiments was treated with pulsating low‐intensity ultrasound (30 mW/cm2; 1.5 MHz) for 20 min/day for a period of 3 or 6 days. The other group served as controls. After culture, the metatarsal bone rudiments were prepared for computer aided light microscopy. The following histomorphometric parameters were determined: length, width and volume of the calcified cartilage and of the bone collar, and cell number. GLM analysis demonstrated that bone collar volume and calcified cartilage percentage were significantly higher in the ultrasound‐stimulated rudiments compared to untreated controls. Further, the calcified cartilage volume bordering the hypertrophic zone was significantly higher than in the center of the bone rudiment. Ultrasound treatment did not change the number of the cells.

These results suggest that the stimulatory effect of low‐intensity ultrasound on endochondral ossification is likely due to stimulation of bone cell differentiation and calcified matrix production, but not to changed cell proliferation. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Femoral head blood flow reduction and hypercoagulability under 24 h megadose steroid treatment in pigs
Authors: Drescher Wolf , Weigert Karen P. , Bünger Mathias H. , Ingerslev Jørgen , Bünger Cody , Hansen Ebbe S.
Published: December 2003

The pathogenesis of corticosteroid‐induced femoral head necrosis is assumed to be ischemia. The purpose of this study was to investigate the perfusion pattern of the femoral head and plasma coagulability during 24 h corticosteroid megadose treatment, as recommended by the National Acute Spinal Cord Injury Studies (NASCIS), in the awake big animal model. Blindedly, 9 animals underwent megadose methylprednisolone infusion (30 mg/kg intravenously as an initial bolus, followed by 5.4 mg/kg/h for further 23 h) while 9 animals served as placebo treated controls. Regional blood flow of the systematically subdivided femoral head, proximal femur, acetabulum, and soft tissue hip regions was investigated by the microsphere technique at steady state (phase 1), after the initial bolus infusion (phase 2), and after the completed treatment (phase 3). Plasma coagulability was examined in phases 1 and 3. Blood flow of the femoral head epiphysis and metaphyseal cancellous bone was unchanged after one hour of steroid infusion, but decreased after the completed treatment at 24 h in the experimental group. Femoral head blood flow reduction was global without a tendency to more pronounced blood flow decrease in any subregion. Plasma fibrinogen was significantly higher after 24 h of steroid infusion than in the placebo control group. 24 h high dose methylprednisolone treatment causes femoral head blood flow reduction and hypercoagulability of plasma in the normal awake immature pig. These findings may be pathogenetic factors in the early stage of steroid‐induced osteonecrosis. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Extracorporeal shock waves promote healing of collagenase‐induced Achilles tendinitis and increase TGF‐β1 and IGF‐I expression
Authors: Chen Yeung‐Jen , Wang Ching‐Jen , Yang Kuender D. , Kuo Yur‐Ren , Huang Hui‐Chen , Huang Yu‐Ting , Sun Yi‐Chih , Wang Feng‐Sheng
Published: December 2003

Extracorporeal shock waves (ESW) have recently been used in resolving tendinitis. However, mechanisms by which ESW promote tendon repair is not fully understood. In this study, we reported that an optimal ESW treatment promoted healing of Achilles tendintis by inducing TGF‐β1 and IGF‐I. Rats with the collagenease‐induced Achilles tendinitis were given a single ESW treatment (0.16 mJ/mm2 energy flux density) with 0, 200, 500 and 1000 impulses. Achilles tendons were subjected to biomechanical (load to failure and stiffness), biochemical properties (DNA, glycosaminoglycan and hydroxyproline content) and histological assessment. ESW with 200 impulses restored biomechanical and biochemical characteristics of healing tendons 12 weeks after treatment. However, ESW treatments with 500 and 1000 impulses elicited inhibitory effects on tendinitis repair. Histological observation demonstrated that ESW treatment resolved edema, swelling, and inflammatory cell infiltration in injured tendons. Lesion site underwent intensive tenocyte proliferation, neovascularization and progressive tendon tissue regeneration. Tenocytes at the hypertrophied cellular tissue and newly developed tendon tissue expressed strong proliferating cell nuclear antigen (PCNA) after ESW treatment, suggesting that physical ESW could increase the mitogenic responses of tendons. Moreover, the proliferation of tenocytes adjunct to hypertrophied cell aggregate and newly formed tendon tissue coincided with intensive TGF‐β1 and IGF‐I expression. Increasing TGF‐β1 expression was noted in the early stage of tendon repair, and elevated IGF‐I expression was persisted throughout the healing period. Together, low‐energy shock wave effectively promoted tendon healing. TGF‐β1 and IGF‐I played important roles in mediating ESW‐stimulated cell proliferation and tissue regeneration of tendon. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Climatic and volcanic forcing revealed in a 50,000-year diatom record from Lake Massoko, Tanzania
Authors: Barker Philip , Williamson David , Gasse Françoise , Gibert Elisabeth
Published: December 2003

The interactions between climatic and volcanic forcing on diatom communities contained in a 50,000-year sedimentary sequence from Lake Massoko, Tanzania, were examined. At the century scale, 19 discrete tephra inputs to the lake isolated the sedimentary nutrient supply and shifted the diatom communities to those tolerant of low phosphorus levels, whereas at the millennial scale, diatom-inferred shifts in precipitation–evaporation based on conductivity optima and diatom life-form ratios were broadly similar to lake-level reconstructions from Lake Rukwa, Lake Malawi, and others in the region. Some fluctuations of Lake Massoko are consistent with the precession-driven changes in insolation, but the major climate shifts do not relate directly to orbital forcing of summer insolation south of the equator and show more consistency with records from the equatorial and northern tropics that receive rainfall from the passing of the intertropical convergence zone. Sea surface temperatures are strongly correlated to multimillennial-scale climate patterns over this region of Africa.
Holocene climate phases from buried soils in Tigray (northern Ethiopia): comparison with lake level fluctuations in the Main Ethiopian Rift
Authors: Dramis Francesco , Umer Mohammed , Calderoni Gilberto , Haile Mitiku
Published: December 2003

Stratigraphic analysis of alluvial/colluvial sequences and 14C dating have been used as proxies for Holocene climate changes in the highlands of Tigray (northern Ethiopia). The studied records show alternations of buried soils and peaty–clayey sediments, pointing to wet, stabilization phases, and organic-free colluvium layers resulting from the abrupt occurrence of dry-climate episodes. The 14C dates, mostly unpublished, cluster in the 11,090–9915, 9465–9135, 8450–7330, 6720–3635, 2710–2345, and 1265–790 cal yr B.P. time spans. Evidence of subsequent pedogenesis is lacking in the area, apart from a buried humified horizon dated at 300 ± 60 14C yr B.P. (460–295 cal yr B.P.). Both the timing and the pattern of Tigray paleoclimatic events fit the corresponding framework, based on lake level changes, previously implemented for the Main Rift Valley. These findings give further support for arguing that the forcing mechanisms of the wet/dry fluctuations during the Holocene were effective over a large scale.
The ubiquitin‐proteasome pathway is required for the function of the viral VP16 transcriptional activation domain
Authors: Zhu Qianzheng , Yao Jihong , Wani Gulzar , Chen Jianming , Wang Qi-En , Wani Altaf A
Published: December 2003

The ability of the activation domain of specific protein factors to regulate transcription is intimately connected to their ubiquitin‐mediated proteolysis. Here, we provide evidence that ubiquitin‐proteasome function is required for a family of synthetic viral VP16 transcription activators in mammalian cells. Blocking the degradation of VP16 activators, through proteasome inhibitors or by disrupting the ubiquitylation function, severely compromises their transcriptional activity. Overexpression of SUG‐1, a subunit of the proteasome, reduces both transactivation and degradation of VP16 activators. The inhibitory effect of SUG‐1 overexpression is enhanced when a single non‐removable ubiquitin moiety is fused to the amino‐terminus of the VP16 activator. The 19S regulatory subunit of the proteasome physically associates with the general transcription factor TFIIH, indicating the direct involvement of the proteasome in transcription. These results support a model in which ubiquitin plays an accessory role, in recruiting the 19S regulatory subunit of the proteasome, for transcriptional activation.
Engineering the serine/threonine protein kinase Raf‐1 to utilise an orthogonal analogue of ATP substituted at the N6 position
Authors: Hindley Alison D , Park Sungdae , Wang Lily , Shah Kavita , Wang Yanli , Hu Xiche , Shokat Kevan M , Kolch Walter , Sedivy John M , Yeung Kam C
Published: December 2003

One key area of protein kinase research is the identification of cognate substrates. The search for substrates is hampered by problems in unambiguously assigning substrates to a particular kinase in vitro and in vivo. One solution to this impasse is to engineer the kinase of interest to accept an ATP analogue which is orthogonal (unable to fit into the ATP binding site) for the wild‐type enzyme and the majority of other kinases. The acceptance of structurally modified, γ‐32P‐labelled, nucleotide analogue by active site‐modified kinase can provide a unique handle by which the direct substrates of any particular kinase can be displayed in crude mixtures or cell lysates. We have taken this approach with the serine/threonine kinase Raf‐1, which plays an essential role in the transduction of stimuli through the Ras→Raf→MEK→ERK/MAP kinase cascade. This cascade plays essential roles in proliferation, differentiation and apoptosis. Here we detail the mutagenesis strategy for the ATP binding pocket of Raf‐1, such that it can utilise an N
6‐substituted ATP analogue. We show that these mutations do not alter the substrate specificity and signal transduction through Raf‐1. We screen a library of analogues to identify which are orthogonal for Raf‐1, and show that mutant Raf‐1 can utilise the orthogonal analogue N
6(2‐phenethyl) ATP in vitro to phosphorylate its currently only accepted substrate MEK. Importantly we show that our approach can be used to tag putative direct substrates of Raf‐1 kinase with 32P‐N
6(2‐phenethyl) ATP in cell lysates.
Inhibition of angiotensin converting enzyme (ACE) activity by flavan‐3‐ols and procyanidins
Authors: Actis-Goretta Lucas , Ottaviani Javier I , Keen Carl L , Fraga Cesar G
Published: December 2003

It was determined that flavan‐3‐ols and procyanidins have an inhibitory effect on angiotensin I converting enzyme (ACE) activity, and the effect was dependent on the number of epicatechin units forming the procyanidin. The inhibition by flavan‐3‐ols and procyanidins was competitive with the two substrates assayed: N‐hippuryl‐L‐histidyl‐L‐leucine (HHL) and N‐[3‐(2‐furyl)acryloyl]‐L‐phenylalanylglycylglycine (FAPGG). Tetramer and hexamer fractions were the more potent inhibitors, showing Ki of 5.6 and 4.7 μM, respectively. As ACE is a membrane protein, the interaction of flavanols and procyanidins with the enzyme could be related to the number of hydroxyl groups on the procyanidins, which determine their capacity to be adsorbed on the membrane surface.
Growth hormone induces eNOS expression and nitric oxide release in a cultured human endothelial cell line
Authors: Thum Thomas , Tsikas Dimitris , Frölich Jürgen C , Borlak Jürgen
Published: December 2003

Growth hormone deficiency is linked to cardiovascular disease and particularly increased peripheral vascular resistance. Surprisingly, its role in endothelial nitric oxide (NO) synthetase (eNOS) regulation and NO release is basically unknown. We therefore studied the effects of different doses of somatotropin in cultures of a human endothelial cell line (EAhy926). We investigated expression and activity of eNOS, as well as other target genes known to be deregulated in cardiovascular disease including E‐selectin and the lectin‐like oxidized low density lipoprotein receptor. Treatment of cultured human endothelial cells with somatotropin resulted in significant (P<0.05) increases of eNOS gene and protein expression, as well as NO release, whereas production of intracellular reactive oxygen species was significantly reduced, at the highest somatotropin dose level. The enhanced eNOS gene/protein expression and enzyme activity correlate well. Our findings are suggestive for a novel role of growth hormone in endothelial biology, and particularly NO production.
Laparoscopic tubal anastomosis
Authors: Ribeiro S.C. , Tormena R.A. , Giribela C.G. , Izzo C.R. , Santos N.C. , Pinotti J.A.
Published: December 2003

Objectives: To evaluate the pregnancy outcome after laparoscopic tubal anastomosis. Methods: From December 1998 to December 2001, 26 patients with bilateral tubal ligation who underwent laparoscopic tubal anastomosis were prospectively evaluated. Patients’ age varied from 28 to 37 years. Results: Laparoscopic tubal reversal was performed in 23 patients. Bilateral reversal was possible in all but two patients. The operation time ranged from 95 to 155 min and all patients were discharged in the following morning after surgery. After 3 months, tubal patency was confirmed in 15 patients (15/23). Pregnancy rate was 56.5% (13/23), without ectopic pregnancies. The average time from tubal reversal and pregnancy was 6 months. Conclusions: In selected cases, laparoscopic tubal reversal can be offered to patients who had been submitted to tubal sterilization and desire new pregnancies. Patient selection as well as meticulous surgical technique are key factors in achieving satisfactory pregnancy rates.
Laparoscopic adnexectomy for benign tubo‐ovarian disease using abdominal wall lift: a comparison to laparotomy
Authors: Tintara H. , Choobun T.
Published: December 2003

Objectives: To evaluate the results of laparoscopic adnexectomy using an abdominal wall‐lifting device compared to laparotomy. Methods: From February 1997 to December 2001, laparoscopic adnexectomy was performed in 68 cases of benign diseases in a university hospital. Three cases (4.4%) were converted to laparotomy due to poor visualization. The control group was a similar cohort of 65 patients who underwent the same procedures using laparotomy. Results: There were 59 ovarian cysts and six tubal pregnancies in each group. Mean analgesic used, hospital stay, recovery period and blood loss were 11.5 mg, 2.0 days, 1.0 week and 49 ml, compared with 151.8 mg, 4.0 days, 3.0 weeks, and 122 ml in the laparotomy group (P<0.0005). Mean operating times and hospital charges were 81.7 min and $293.9 (US), compared with 77.1 min (P=0.108) and $272.7 (US) (P=0.033) in the laparotomy group. No serious complications were found in either group. Conclusions: Gasless laparoscopic adnexectomy is a safe and effective technique to provide laparoscopic benefit with minimal increase in hospital charges.
Mifepristone‐induced abortion and birth weight in the first subsequent pregnancy
Authors: Yimin C , Wei Y , Weidong C , Xianmi W , Junqing W , Lin L
Published: December 2003

Objectives: To assess the effect of a medically induced abortion (MA) on birth weight in the first subsequent pregnancy. Methods: Pregnant women who had had a MA, a surgical abortion (SA), or primigravidas with no history of abortion (NA), were recruited for a prospective cohort study between July 1998 and February 2001. The sample for the present analysis included 12 995 singleton live births at term. Results: The overall incidence rate of low birth weight (LBW) was 1.0%. The rates of LBW in the MA, SA, and NA groups were 1.0%, 0.9%, and 1.2, respectively. There were no significant differences in LBW rates between the MA and SA groups, neither between the MA and NA. Logistic regression analysis was used to estimate the effects of MA on birth weight, and we found no relationship between risk of LBW and MA. Conclusions: We did not find a statistically significant relationship between a history of one medically induced abortion and LBW for the first subsequent term pregnancy.
Quantitative considerations of dissolved barium as a tracer in the Arctic Ocean
Authors: Taylor John Ryan , Falkner Kelly Kenison , Schauer Ursula , Meredith Mike
Published: December 2003

Dissolved barium (Ba) was measured along transects across Fram and Denmark Straits as part of the 1998 ARK‐XIV/2 Polarstern expedition. Results are combined with other available tracer observations to analyze water mass composition at Fram Strait. A combination of Pacific water and Eurasian river runoff dominated (>80% and >10% of the total mass, respectively) the upper East Greenland Current (EGC), while the remainder of the section was dominated by North Atlantic water. A much smaller contribution of Pacific water to the EGC (≈50%) at Fram Strait in 1987 suggests that this component can be quite variable in time. North American river water was not detectable at Fram Strait in 1998. Presumably, the Eurasian river water we observed at Fram Strait transited eastward along shelf within the Arctic, mixed with Pacific water in the vicinity of the East Siberian Sea, and was borne by the transpolar drift across the Arctic Ocean. In the absence of significant net ice formation along the way such a pathway can be expected to produce more pronounced freshening of the EGC than when Eurasian river water mixes more directly off shelf into salty Atlantic waters and Pacific water is diverted largely through the Canadian archipelago. Existing measurements at the main Arctic gateways were used to construct a Ba budget for the Arctic Ocean under conditions of simultaneous mass, heat, and salt conservation. This preliminary budget is statistically consistent with the steady state hypothesis. On the Arctic basin scale, Ba appears to be conservative.
Frequency‐and‐angular HF sounding and ISR diagnostics of TIDs
Authors: Galushko V. G. , Beley V. S. , Koloskov A. V. , Yampolski Y. M. , Paznukhov V. V. , Reinisch B. W. , Foster J. C. , Erickson P.
Published: December 2003

A single digisonde, used as a receiver for ionospheric high frequency signals from broadcast stations, was able to determine the wave characteristics of traveling ionospheric disturbances (TIDs) using frequency shift and arrival angle measurements. During a measurement campaign, aimed at recovering large‐scale wave‐like processes in the upper atmosphere, in March 2001 at the MIT Haystack Observatory (Millstone Hill, MA), a Digisonde Portable Sounder (DPS) made simultaneous observations with the incoherent scatter radar (ISR). The DPS was upgraded to include the frequency and angular sounding (FAS) technique previously developed at the Institute of Radio Astronomy in Kharkov, Ukraine, for TID diagnostics. The DPS with four spaced receive antennas received the radio signals at 3.33 MHz and 7.335 MHz from Radio CHU of the Canadian Time Service (Ottawa, Ontario). The FAS technique recovered the basic parameters of TIDs, i.e., amplitude, speed, and the direction of the propagation vector by modeling the ionosphere as a perfectly reflecting surface. For three days during the campaign the Millstone Hill ISR monitored the ionospheric midpoint using a triangulation mode to identify the direction of motion and speed of the wave‐like ionospheric disturbances. Comparison of the results from the two diagnostic techniques showed good agreement. The wave directions were within 10 to 15 degrees, and speed and wavelength were within 10 to 12%.