bluuebunny/crossref_metadata_2025 huggingface dataset:
Distance training for the restoration of motor function
Authors: van Dijk H , Hermens H J
Published: March 2004

We reviewed the literature on distance training for the restoration of motor function. Computerized literature searches were performed using the MEDLINE, EMBASE, Cinahl and Cochrane databases. Articles that met the criteria for inclusion were divided into three general areas concerning the type of training in relation to motor functions - muscle/joint, balance and cognition. From the publications identified in the literature search, 11 articles met the selection criteria. Six were related to muscle/joint functions, four to balance functions and one to cognitive functions. The articles were graded according to the strength of the scientific evidence they offered. The review revealed some promising applications of distance motor training, such as virtual reality (VR) and robotic devices. The strength of the evidence from these studies was poor, however, probably because the technology is relatively new. In contrast to the studies using VR and robotic devices, those using electromyographic (EMG) biofeedback showed a good to fair strength of scientific evidence. This can be explained by the substantial history of research on the restoration of motor function through the use of EMG biofeedback techniques. When implemented in clinical practice, these applications could reduce the pressure on scarce health-care resources.
Publication output in telemedicine during the period January 1964 to July 2003
Authors: Moser Patrizia L , Hauffe Heinz , Lorenz Ingo H , Hager Martina , Tiefenthaler Werner , Lorenz Helene M , Mikuz Gregor , Soegner Peter , Kolbitsch Christian
Published: March 2004

The MEDLINE database was used to survey the period January 1964 to July 2003 for the number of publications relating to telemedicine ( n = 5911), as well as their distribution by country ( n = 42). Publications per million inhabitants were then correlated with each country's population density, gross national product, human development index (HDI) and number of PCs per 1000 inhabitants. Telemedicine publications made up 0.05% of all medical publications cited in MEDLINE. American and European countries along with others classified as industrialized produced 97% of all telemedicine publications. In terms of publications per million inhabitants, Norway and Finland took the lead. There were significant correlations between telemedicine publications per capita and HDI ( r = -0.60), number of PCs per 1000 inhabitants ( r = 0.73) and gross national product per capita ( r = 0.69), but not population density ( r = -0.12).
A cost-effectiveness analysis of interactive paediatric telecardiology
Authors: Sicotte Claude , Lehoux Pascale , Van Doesburg Nicolaas , Cardinal Godefroy , Leblanc Yves
Published: March 2004

We analysed the cost-effectiveness of a teleconsultation service after five years of operation. The service provides diagnostic consultation at a distance for children suffering from cardiac pathologies. A retrospective study was performed with all 78 infants who had received a paediatric cardiology teleconsultation over a four-year period from January 1998. The cost-effectiveness of telecardiology was compared with that of the conventional means of providing services. Teleconsultation proved to be an effective and reliable method of enhancing access to tertiary care. The number of patient journeys (both emergency transfers and semi-urgent or elective visits to the tertiary care centre) was reduced by 42%. However, the cost analysis demonstrated that teleconsultation did not result in overall cost savings: the total cost of telecardiology was C$272,327 and the total cost of conventional care would have been C$157,212. There were direct savings for patients but not for the health-care system, because of the high cost of the equipment and telecommunication fees. Telemedicine therefore represented a supplementary cost of C$1500 per patient. In summary, telemedicine added to cost but increased effectiveness. The incremental cost-effectiveness ratio of teleconsultation was estimated to C$3488 per patient journey avoided.
Success factors in the long-term sustainability of a telediabetes programme
Authors: Whittaker Sheila L , Adkins Sherry , Phillips Richard , Jones Jean , Horsley Mary A , Kelley George
Published: March 2004

We studied a telediabetes programme that had been in operation for 10 years, to identify the factors in its sustainability. We reviewed archive documents, conducted interviews with programme administrators and primary care providers, observed diabetes consultations and surveyed patient satisfaction. Three success factors were identified: the administration took a long-term view of the value of the telemedicine service; telediabetes enabled structured use of staff time and facilities; and service delivery followed national diabetes standards and a well defined cycle of care within a long-term quality improvement programme. However, the present study did not address the three other key theoretical dimensions of systems design beyond sustainability: size, scalability and scope.
Physician perceptions of the effect of telemedicine on rural retention and recruitment
Authors: Sargeant Joan , Allen Michael , Langille Donald
Published: March 2004

We conducted a postal survey of 140 family and community specialist physicians in a predominantly rural area which had received clinical telemedicine services and videoconferenced continuing medical education (CME) for two years. The questionnaire contained 46 items. The response rate was 47%. Most respondents (83%) reported having attended videoconferenced CME sessions and 45% reported having referred patients for teleconsultation. Physicians in more rural areas used these services more frequently. Ratings of two statements assessing the value of telemedicine in community support were significantly and positively correlated with the number of videoconferenced CME sessions attended and the number of telemedicine services used. In relation to their decision to stay in their community for at least one year, respondents rated telemedicine lower in importance than all but one of 17 other factors expected to influence physician recruitment and retention in rural communities. The influences on physician rural recruitment and retention are complex. However, telemedicine was used more frequently by the more rural physicians, and there was a relationship between higher usage and higher ratings of its value as a community support.
General practitioners' perceptions of asynchronous telemedicine in a randomized controlled trial of teledermatology
Authors: Collins Karen , Bowns Ian , Walters Stephen
Published: March 2004

We studied the perceptions of general practitioners (GPs) towards teledermatology, before and after its introduction into eight general practices for the purposes of a randomized controlled trial. A postal questionnaire was distributed before the trial and again one year later. Thirty-six of the 42 GPs responded on each occasion (a response rate of 86%). In the second survey, only 21% of respondents indicated that they were satisfied with teledermatology in their practice, while 47% said that they were dissatisfied. Thirty-one per cent said that they felt confident about diagnosis and management of care through teledermatology, and 28% reported that they were unconfident. Only 23% of respondents said that they would consider using a telemedicine system in the future, while 34% said they would not (43% were unsure). There were no significant findings to suggest that the GPs' perceptions changed over time. Less favourable responses to telemedicine were found than has been observed in previous studies, which suggests that the model of telemedicine described in this study would not be widely acceptable to GPs.
Teleconsultation in diagnostic pathology: experience from Iran and Germany with the use of two European telepathology servers
Authors: Mireskandari Masoud , Kayser Gian , Hufnagl Peter , Schrader Thomas , Kayser Klaus
Published: March 2004

Eighty pathology cases were sent independently to each of two telepathology servers. Cases were submitted from the Department of Pathology at the University of Kerman in Iran (40 cases) and from the Institute of Pathology in Berlin, Germany (40 cases). The telepathology servers were located in Berlin (the UICC server) and Basel in Switzerland (the iPATH server). A scoring system was developed to quantify the differences between the diagnoses of the referring pathologist and the remote expert. Preparation of the cases, as well as the submission of images, took considerably longer from Kerman than from Berlin; this was independent of the server system. The Kerman delay was mainly associated with a slower transmission rate and longer image preparation. The diagnostic gap between referrers' and experts' diagnoses was greater with the iPATH system, but not significantly so. The experts' response time was considerably shorter for the iPATH system. The results showed that telepathology is feasible for requesting pathologists working in a developing country or in an industrialized country. The key factor in the quality of the service is the work of the experts: they should be selected according to their diagnostic expertise, and their commitment to the provision of telepathology services is critical.
An investigation of videoconferenced geriatric medicine grand rounds in Alberta
Authors: Sclater Keith , Alagiakrishnan Kannayiram , Sclater Anne
Published: March 2004

Geriatric medicine grand rounds (GMGR) from the University of Alberta are videoconferenced weekly to health-care providers at up to 9 urban and 14 rural sites across Alberta. A questionnaire was given to all participants attending 20 consecutive GMGR presentations from January 2002. The response rate was 85% ( n = 625) for all participants and 99% ( n = 123) for physicians alone. The audience was composed of registered nurses (42%), physicians (17%) and other health-care professionals. 'Interest in topic' was cited by 95% as the main reason for attendance. Doctors and nurses cited continuing medical education as an additional factor. The highest attendance was for the topics vascular dementia, behavioural problems in dementia, the genetics of dementia and falls prevention. Participants at the remote sites gave lower evaluations of quality of the GMGR presentations than those at the hub site. The measurement, care and treatment of dementia appeared to be the main concerns of health-care providers across the province. The videoconferencing of GMGR appears to be an effective method of meeting the demands of physicians and allied health professionals for education in geriatric medicine.
A feasibility study of remote consultation to determine suitability for surgery in stroke rehabilitation
Authors: Buurke J H , Kleissen R F M , Nene A , Bloo J K C , Renzenbrink G J , Zeegers A V C M , Doederlein L , Hermens H J
Published: March 2004

We studied knowledge transfer for the determination of the suitability of stroke patients for a specialist surgical procedure (split anterior tibial tendon transfer). Gait analysis data from patients at a general hospital were discussed with an expert in another country using personal computers, an ISDN connection (128 kbit/s) and TCP/IP-based communication tools. The key issue was whether the staff in the general hospital became better able to determine suitability for surgery. Twelve patients were studied. In three of the first four cases the advice of the remote expert changed the plan for surgery. After that the treatment plans did not change after consultation. After eight cases the local clinicians did not need to ask for further advice. There was a rapid increase in skill in determining suitability for surgery. The experience and skills of the local clinicians were thought to increase more rapidly than would have been the case without the consultations with a remote expert.
A pilot study of nurse-led, home-based telecardiology for patients with chronic heart failure
Authors: Scalvini Simonetta , Zanelli Emanuela , Volterrani Maurizio , Martinelli Giovanna , Baratti Doriana , Buscaya Osvaldo , Baiardi Paola , Glisenti Fulvio , Giordano Amerigo
Published: March 2004

We assessed the feasibility of home-based telecardiology for patients with chronic heart failure (CHF). Seventy-four CHF patients were enrolled into a programme of telephone follow-up and single-lead electrocardiography (ECG) monitoring. The patients transmitted their ECG data by fixed telephone line to a receiving station, where a nurse was available for an interactive teleconsultation. Patients were followed up for a mean (SD) of 307 (108) days; 1467 calls were analysed (213 ad hoc consultations and 1254 scheduled consultations). A total of 124 cardiovascular events were recorded. Modifications to therapy were suggested in response to 119 calls; hospital admissions were suggested for 13 patients, further investigations for 7 and a consultation with the patient's general practitioner for 13. No action was taken after 1330 calls. Twenty-two ECG abnormalities were recorded. In 63 patients receiving the beta-blocker carvedilol, the mean dosage increased from 36 to 42 mg. In the previous year there were 1.8 hospitalizations per patient, while in the follow-up period there were 0.2 hospitalizations per patient. Following up CHF patients using a nurse-led telecardiology programme seems to be feasible and useful.
Use of interactive videoconferencing to deliver asthma education to inner-city immigrants
Authors: Reznik Marina , Sharif Iman , Ozuah Philip O
Published: March 2004

Videoconferencing to deliver asthma health education to patients or their parents has not been widely used in the USA. We used two 90 min interactive videoconferences to deliver an asthma education programme to a convenience sample of mainly Latino immigrant parents in the Bronx, New York. In these sessions short presentations were given on asthma triggers, medications and the prevention of asthma exacerbations. To test gains in knowledge, we administered a self-completion questionnaire consisting of true/false statements before and after the videoconferences. Sixty subjects participated in the first videoconference and 56 in the second. Asthma knowledge improved significantly after both. Three months later, knowledge retention from the first videoconference was good. The majority of subjects asked questions and commented on their personal experiences of asthma. Interactive videoconferencing allowed asthma education to be delivered to a large immigrant population, elicited concerns from the audience and was effective in improving knowledge.
Work Groups, Structural Diversity, and Knowledge Sharing in a Global Organization
Authors: Cummings Jonathon N.
Published: April 2004

Effective work groups engage in external knowledge sharing—the exchange of information, know-how, and feedback with customers, organizational experts, and others outside of the group. This paper argues that the value of external knowledge sharing increases when work groups are more structurally diverse. A structurally diverse work group is one in which the members, by virtue of their different organizational affiliations, roles, or positions, can expose the group to unique sources of knowledge. It is hypothesized that if members of structurally diverse work groups engage in external knowledge sharing, their performance will improve because of this active exchange of knowledge through unique external sources. A field study of 182 work groups in a Fortune 500 telecommunications firm operationalizes structural diversity as member differences in geographic locations, functional assignments, reporting managers, and business units, as indicated by corporate database records. External knowledge sharing was measured with group member surveys and performance was assessed using senior executive ratings. Ordered logit analyses showed that external knowledge sharing was more strongly associated with performance when work groups were more structurally diverse. Implications for theory and practice around the integration of work groups and social networks are addressed.
The Dynamic Pricing Problem from a Newsvendor's Perspective
Authors: Monahan George E. , Petruzzi Nicholas C. , Zhao Wen
Published: April 2004

The dynamic pricing problem concerns the determination of selling prices over time for a product whose demand is random and whose supply is fixed. We approach this problem in a novel way by formulating a dynamic optimization model in which the demand function is isoelastic but the random demand process is quite general. Ultimately, what we find is a strong parallel between the dynamic pricing problem and dynamic inventory models. This parallel leads to a reinterpretation of the dynamic pricing problem as a price-setting newsvendor problem with recourse, which is useful not only because it yields insights into the optimal solution, but also because it leads to additional insights into how pricing recourse affects the actions and profits of a price-setting newsvendor. We make contributions in three areas: First, we develop structural properties that define an optimal pricing strategy over a finite horizon and investigate how that policy impacts a newsvendor's optimal procurement policy and optimal expected profit. Second, we establish a practical and efficient algorithm for computing the optimal prices. Third, we examine how market parameters affect the optimal solution through a series of numerical experiments that utilize the algorithm.
DDI‐μFIA—A Readily Configurable Microarray‐Fluorescence Immunoassay Based on DNA‐Directed Immobilization of Proteins
Authors: Wacker Ron , Niemeyer Christof M.
Published: April 2004

We describe a chip‐based immunoassay for multiplex antigen detection, based on the self‐assembly of semi‐synthetic DNA–protein conjugates to generate an easily configurable protein microarray. The general principle of this microarray‐fluorescence immunoassay (μFIA) is similar to that of a two‐sided (sandwich) immunoassay. However, covalent single‐stranded DNA–streptavidin conjugates are employed for the efficient immobilization of biotinylated capture antibodies through hybridization to complementary surface‐bound DNA oligomers. In a model system, we use the DNA‐directed immobilization (DDI) of antibodies to generate an antibody microarray for the parallel detection of the tumor marker human carcinoembryonic antigen (CEA), recombinant mistletoe lectin rViscumin (rVis), ceruloplasmin (CEP), and complement‐1‐inactivator (C1 A) in human blood serum samples. Detection limits down to 400 pg mL−1 are reached. In addition, we describe a method for the internal standardization of protein microarray analyses, based on the simultaneous measurement of constant amounts of the blood proteins CEP and C1 A, intrinsically present in human serum, to compensate for interexperimental variations usually occurring in microarray analyses. The standardization leads to a significantly higher data reliability and reproducibility in intra‐ and interassay measurements. We further demonstrate that the DDI‐μFIA can also be carried out in a single step by tagging of the analyte simultaneously with both capture and detection antibody and subsequent immobilization of the immunocomplex formed, on the DNA microarray capture matrix. This protocol significantly reduces handling time and costs of analysis.
Immunological Optimization of a Generic Hydrophobic Pocket for High Affinity Hapten Binding and Diels–Alder Activity
Authors: Piatesi Andrea , Hilvert Donald
Published: April 2004

Antibody 1E9, which binds a tetrachloronorbornene derivative with subnanomolar affinity and catalyzes the Diels–Alder reaction between tetrachlorothiophene dioxide and N‐ethylmaleimide with high efficiency, arose from a family of highly restricted germ‐line immunoglobulins that bind diverse hydrophobic ligands. Two somatic mutations, one at position L89 in the light chain (SerL89Phe) and another at position H47 in the heavy chain (TrpH47Leu), have been postulated to be responsible for the unusually high degree of shape and chemical complementarity observed in the crystal structure of 1E9 complexed with its hapten. To test this hypothesis, the germ‐line sequence at these two positions was restored by site‐directed mutagenesis. The ensuing 160 to 3900‐fold decrease in hapten affinity and the complete loss of catalytic activity support the hypothesis that these somatic mutations substantially remodel the antibody binding pocket. Mutation of the highly conserved hydrogen‐bond donor AsnH35, which sits at the bottom of the active site and is a hallmark of this family of antibodies, is also catastrophic with respect to hapten binding and catalysis. In contrast, residues in the CDR H3 loop, which contributes a significant fraction of the hapten‐contacting protein surface, have a more subtle influence on the properties of 1E9. Interestingly, while most changes in this loop have neutral or modestly deleterious effects, replacement of MetH100b at the floor of the pocket with phenylalanine leads to a significant sevenfold increase in catalytic activity. The latter result is surprising given the unusually close fit of the parent antibody to the transition‐state analogue. Further fine‐tuning of the interactions between 1E9 and its ligands by introducing mutations outside the active site could conceivably yield substantially more active catalysts.
Membrane Protein–Lipid Interactions in Mixed Micelles Studied by NMR Spectroscopy with the Use of Paramagnetic Reagents
Authors: Hilty Christian , Wider Gerhard , Fernández César , Wüthrich Kurt
Published: April 2004

For solution NMR studies of the structure and function of membrane proteins, these macromolecules have to be reconstituted and solubilized in detergent micelles. Detailed characterization of the mixed detergent/protein micelles is then of key importance to validate the results from such studies, and to evaluate how faithfully the natural environment of the protein in the biological membrane is mimicked by the micelle. In this paper, a selection of paramagnetic probes with different physicochemical properties are used to characterize the 60 kDa mixed micelles consisting of about 90 molecules of the detergent dihexanoylphosphatidylcholine (DHPC) and one molecule of the Escherichia coli outer‐membrane protein X (OmpX), which had previously been extensively studied by solution NMR techniques. The observation of highly selective relaxation effects on the NMR spectra of OmpX and DHPC from a water‐soluble relaxation agent and from nitroxide spin labels attached to lipophilic molecules, confirmed data obtained previously with more complex NMR studies of the diamagnetic OmpX/DHPC system, and yielded additional novel insights into the protein–detergent interactions in the mixed micelles. The application of paramagnetic probes to the well‐characterized OmpX/DHPC system indicates that such probes should be widely applicable as an efficient support of NMR studies of the topology of mixed membrane protein–detergent micelles.
Isolation and developmental expression of Mitf in Xenopus laevis
Authors: Kumasaka Mayuko , Sato Hiraku , Sato Shigeru , Yajima Ichiro , Yamamoto Hiroaki
Published: April 2004

Mitf (gene for microphthalmia‐associated transcription factor) encodes a transcription factor of the basic/helix‐loop‐helix/leucine‐zipper family and is a key regulator during the development of two different types of melanin‐producing cell lineages, namely neural crest‐derived melanocytes/melanophores, and the retinal pigment epithelium (RPE) differentiated from the outer layer of the eye cup. Mitf‐deficient mice show a lack of melanocytes and small eyes caused by abnormal RPE development. An interesting feature of Mitf is the existence of multiple isoforms with different amino termini and their functions in the development of these melanin‐producing pigment cells. In this study, we isolated two Mitf homologues (XlMitfα and XlMitfβ) and their isoforms from Xenopus laevis. Alignment analysis of the amino acid sequences of the N‐termini suggests that these isoforms are homologues of mouse Mitf‐M (expressed specifically in the melanocyte lineage) and Mitf‐A (strongly expressed in the RPE, although this expression is ubiquitous). In Xenopus, XlMitfα is strongly expressed in the melanophore lineage (especially in premigratory melanoblasts) and the presumptive RPE and the epiphysis, in which melanin‐producing cells differentiate in some vertebrates. Conservation of the Mitf isoforms expected to possess specific functions in the development of melanin‐producing cells and of the expressions in such cell types in Xenopus suggest that XlMitf plays a central role in the development of melanin‐producing cell lineages, and that, as in mice and humans, most of the signaling molecules or transcription factors implicated genetically in the development of melanin‐producing cell lineages affect either Mitf expression or its function (Goding [2000] Genes Dev. 14:1712–1728). Developmental Dynamics 230:107–113, 2004. © 2004 Wiley‐Liss, Inc.
Different molecular mechanisms underlie placental overgrowth phenotypes caused by interspecies hybridization, cloning, and Esx1 mutation
Authors: Singh Umashankar , Fohn Laurel E. , Wakayama Teruhiko , Ohgane Jun , Steinhoff Christine , Lipkowitz Bettina , Schulz Ralph , Orth Annie , Ropers H. Hilger , Behringer Richard R. , Tanaka Satoshi , Shiota Kunio , Yanagimachi Ryuzo , Nuber Ulrike A. , Fundele Reinald
Published: April 2004

To obtain a deeper insight into the genes and gene networks involved in the development of placentopathies, we have assessed global gene expression in three different models of placental hyperplasia caused by interspecies hybridization (IHPD), cloning by nuclear transfer, and mutation of the Esx1 gene, respectively. Comparison of gene expression profiles of approximately 13,000 expressed sequence tags (ESTs) identified specific subsets of genes with changed expression levels in IHPD, cloned, and Esx1 mutant placentas. Of interest, only one gene of known function and one EST of unknown function were found common to all three placentopathies; however, a significant number of ESTs were common to IHPD and cloned placentas. In contrast, only one gene was shared between IHPD and Esx1 mutant, and cloned and Esx1 mutant placentas, respectively. These genes common to different abnormal placental growth genotypes are likely to be important in the occurrence of placentopathy. Developmental Dynamics 230:149–164, 2004. © 2004 Wiley‐Liss, Inc.
Synthesis, Structures and Luminescent Properties of σ‐Alkynyl Complexes of Orthomercuriated Schiff Bases
Authors: Wong Wai‐Yeung , Lu Guo‐Liang , Liu Li , Shi Jian‐Xin , Lin Zhenyang
Published: April 2004

A novel series of σ‐alkynyl complexes of orthomercuriated Schiff bases of substituted benzylideneanilines and anthracenylmethyleneanilines were synthesised in good yields by alkynylation of the mercuric chlorides of the appropriate Schiff bases with terminal alkynes RC≡CH (R = Ph, ferrocenyl, p‐ferrocenylphenyl) at room temperature in a basic medium. All the new compounds generally displayed good solubility in polar organic solvents and their identities were completely elucidated by various spectroscopic methods. The X‐ray crystal structures of these acetylide‐functionalised compounds represent the first structurally characterised examples of such alkynylmercury(II) complexes and confirmed that the alkynylmercury(II) moiety is directed to the ortho position of the N‐phenyl ring of the Schiff bases. In one instance, the crystal structure reveals that a loose 1D polymeric aggregate is formed for the first time through a combination of weak intermolecular Hg···Hg and Hg···η2‐C≡C interactions to afford an infinite zigzag chain of Hg atoms supported by acetylide linkages. All the complexes in this study were found to exhibit rich luminescence and solution redox behaviour and correlation of these data with the theoretical calculations by the density functional theory was made. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Characterisation of Two Supramolecular Polymers [CuAg4(CN)6(tacn)]n and [CuAu2(CN)4(tacn)]n Containing Metal−Metal Interactions
Authors: Han Wei , Yi Long , Liu Zhan‐Quan , Gu Wen , Yan Shi‐Ping , Cheng Peng , Liao Dai‐Zheng , Jiang Zong‐Hui
Published: April 2004

Two novel heterobimetallic supramolecular polymers, [CuAg4(CN)6(tacn)]n (1) and [CuAu2(CN)4(tacn)]n (2) (tacn = 1,4,7‐triazacyclononane), have been synthesised from the building block [Cu(tacn)]2+, together with [Ag(CN)2]− (for 1) and [Au(CN)2]− (for 2). The large difference in structural type between 1 and 2 is probably due to the fact that the AgI centre is three‐coordinate and trigonal whereas the AuI centre is linear. Metal−metal interactions play an important role in the formation of the supramolecular framework of 1 and the novel topology of 2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Optically Active Phospholanes as Substituents on Ferrocene and Chromium‐Arene Complexes
Authors: Braun Wolfgang , Calmuschi Beatrice , Haberland Jürgen , Hummel Werner , Liese Andreas , Nickel Thomas , Stelzer Othmar , Salzer Albrecht
Published: April 2004

An improved synthesis of (R,R)‐ and (S,S)‐hexane‐2,5‐diol is presented. The (S,S)‐derivative was converted into a cyclic sulfate, which on treatment with NaPH2 in liquid ammonia ultimately gave the secondary (R,R)‐2,5‐dimethylphospholane. This phospholane can be introduced into the side chain of chiral tricarbonylchromium and ferrocene derivatives to give new bidentate ligands of the Josiphos and Daniphos type. Both the ferrocene‐ and tricarbonylchromium‐based diphosphanes have been characterized by X‐ray diffraction analysis. A discussion of their structural features is included. The new ligands were successfully applied to the enantioselective hydrogenation of itaconic acid esters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Five‐ and Six‐Coordinate Ruthenium(II) Complexes Containing the Bidentate Phosphane (−)‐N,N‐Bis(diphenylphosphanyl)‐(S)‐1‐phenylethylamine [(S)‐peap]: X‐ray Crystal Structure of the First 16‐Electron Ruthenium Complex Bearing a Four‐Membered Ring [RuCl{κ2‐P,P‐(S)‐peap}2][SbF6]·C2H4Cl2
Authors: Díez Josefina , Gamasa M. Pilar , Gimeno José , Rodríguez Yolanda , García‐Granda Santiago
Published: April 2004

The complex trans‐[RuCl2{κ2‐P,P‐(S)‐peap}2] (1) has been stereoselectively prepared by the treatment of a stoichiometric mixture of complex [RuCl2(DMSO)4] (DMSO = dimethyl sulfoxide) and (S)‐peap [(S)‐peap = (−)‐N,N‐bis(diphenylphosphanyl)‐(S)‐1‐phenylethylamine] in refluxing toluene. Irradiation of a dichloromethane solution of 1 with a UV lamp (400 W) at −15 °C affords the complex cis‐[RuCl2{κ2‐P,P‐(S)‐peap}2] (2). The thermodynamically stable trans isomer 1 has also been obtained by heating complex 2 in toluene. The reaction of 1 with AgSbF6 in dichloromethane yields the complex [RuCl{κ2‐P,P‐(S)‐peap}2][SbF6] (3), the first 16‐electron cationic ruthenium complex bearing a four‐membered chelate diphosphane ligand which has been fully characterized including its X‐ray crystal structure. The reaction of unsaturated derivative 3 with CO gives the six‐coordinate complex cis‐[RuCl(CO){κ2‐P,P‐(S)‐peap}2][SbF6] (4) in a stereoselective manner, which slowly transforms into trans‐[RuCl(CO){κ2‐P,P‐(S)‐peap}2][SbF6] (5) in a dichloromethane solution. The reaction of [RuCl{κ2‐P,P‐(S)‐peap}2][BF4] with 1‐phenyl‐2‐propyn‐1‐ol in 1,2‐dichloroethane (60 °C) affords the allenylidene derivative trans‐[RuCl(=C=C=CHPh){κ2‐P,P‐(S)‐peap}2][BF4] (6). The cis‐[Ru(acac){κ2‐P,P‐(S)‐peap}2][SbF6] (7) is prepared by reaction of 3 and Na[acac]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Ruthenium(II) Complexes Bearing Carboxylato and 2‐Oxocarboxylato Ligands
Authors: Müller Rainer , Hübner Eike , Burzlaff Nicolai
Published: April 2004

The syntheses of ruthenium(II) acetato and benzoato complexes [Ru(bdmpza)(O2CCH3)(PPh3)] (6) and [Ru(bdmpza)(O2CPh)(PPh3)] (7) [bdmpza = bis(3,5‐dimethylpyrazol‐1‐yl)acetate] are reported. The complexes 6 and 7 are synthesized in high yield from [Ru(bdmpza)Cl(PPh3)2] (1) and thallium acetate (2) or thallium benzoate (3). In a similar substitution reaction a benzoylformate complex [Ru(bdmpza){O2CC(O)Ph}(PPh3)] (8) is obtained from 1 and thallium benzoylformate (4). Reaction of 6 or 7 with benzoylformic acid also yields 8. In analogous reactions several 2‐oxocarboxylato ruthenium(II) complexes [Ru(bdmpza){O2CC(O)R}(PPh3)] (9: R = CH2CH2CO2H, 10: R = Me, 11: R = Et) can be obtained. The low‐spin ruthenium(II) complexes 8 to 11 exhibit a purple or brownish‐red colour caused by MLCT transitions and thus a HOMO−LUMO gap which is almost identical to that of high‐spin 2‐oxoglutarate dependent iron oxygenases. 6 crystallises as a water adduct, 6·H2O and 8 forms an acetonitrile adduct 12. Crystal structures of the water adduct 6·H2O and 8 were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Sugar Syrup Concentration Using Reverse Osmosis Membranes
Authors: Madaeni S.S. , Tahmasebi K. , Kerendi S.H.
Published: April 2004

In sugar manufacturing industries, initially dilute syrup is obtained from the cane sugar or beetroot, which should be concentrated. In many factories, sugar syrup concentration is carried out using evaporation. This process has two main problems. Firstly, it consumes a huge amount of energy due to high latent heat of water and secondly, heating may decompose the sugar molecules resulting in low‐quality and dark‐colored sugar. Low energy consuming reverse osmosis may be employed for concentrating sugar syrup without decomposing the molecules, resulting in high‐quality sugar with low cost. In this study different commercial reverse osmosis membranes (DS, DSII, PVD, FT30, BW30) and one nanofiltration membrane (NF45) were used for sugar syrup concentration. The results show that nanofiltration NF45 membrane has no effect on sugar syrup concentration. The rejections of sugar using DSII and PVD reverse osmosis membranes vary between 23 % and 33 % for different operating conditions. DS membrane rejected around 10 % of the sugar molecules in best conditions. FT30 membrane initially showed better performance (55 %). However, the rejection was decreased during time (minimum 7 %). For BW30 membrane, the rejection of sugar was better (60 %) compared to the other membranes used in this work. For two‐stage processes (i.e. the permeate of the first stage used as a feed for the second stage) the highest rejection (88 %) was obtained.
Fungal Biodegradation and Detoxification of Cork Boiling Wastewaters
Authors: Mendonça E. , Pereira P. , Martins A. , Anselmo A.M.
Published: April 2004

The ability of several fungal strains to degrade and to detoxify cork boiling wastewaters was investigated. The fungal strains used in this work were Sporothrix sp., Trichoderma koningii, Chrysonilia sitophila and Penicillium glabrum isolated from cork bark as well as Fusarium flocciferum and Phanerochaete chrysosporium. The results obtained in the degradation experiments carried out with each fungus showed that all fungi display similar abilities, with a chemical oxygen demand reduction of 54.2 % (± 4.7 %) attained within five days of incubation. F. flocciferum presented the highest value for the reduction of chemical oxygen demand of 62 %. In addition, a rise in pH values of around 3 units was detected with all the strains, except for Penicillium glabrum. Toxicity tests performed on Vibrio fischeri revealed that fungal treatment of the wastewaters causes the complete loss of toxicity in the cases of Sporothrix sp., T. koningii, P. chrysosporium and F. flocciferum. The other two tested strains were also able to detoxify the raw wastewaters, causing a ten‐fold decrease in toxicity. The results obtained in sequential biodegradation experiments with different pairs of fungi showed that although the increment in the COD reduction did not exceed 10 %, an important reduction in toxicity and a pH rise were attained.
Enhancement of Lead(II) Biosorption by Microalgal Biomass Immobilized onto Loofa (Luffa cylindrica) Sponge
Authors: Akhtar N. , Iqbal J. , Iqbal M.
Published: April 2004

A unicellular green microalga, Chlorella sorokiniana, was immobilized on loofa (Luffa cylindrica) sponge and successfully used as a new biosorption system for the removal of lead(II) ions from aqueous solutions. The biosorption of lead(II) ions on both free and immobilized biomass of C. sorokiniana was investigated using aqueous solutions in the concentration range of 10–300 mg/L. The biosorption of lead(II) ions by C. sorokiniana biomass increased as the initial concentration of lead(II) ions increased in the medium. The maximum biosorption capacity for free and immobilized biomass of C. sorokiniana was found to be 108.04 and 123.67 mg lead(II)/g biomass, respectively. The biosorption kinetics were found to be fast, with 96 % of adsorption within the first 5 min and equilibrium reached at 15 min. The adsorption of lead(II) both by free and immobilized C. sorokiniana biomass followed the Langmuir isotherm. The biosorption capacities were detected to be dependent on the pH of the solution; and the maximum adsorption was obtained at a solution pH of about 5. The effect of light metal ions on lead(II) uptake was also studied and it was shown that the presence of light metal ions did not significantly affect lead(II) uptake. The loofa sponge‐immobilized C. sorokiniana biomass could be regenerated using 0.1 M HCl, with up to 99 % recovery. The desorbed biomass was used in five biosorption‐desorption cycles, and no noticeable loss in the biosorption capacity was observed. In addition, fixed bed breakthrough curves for lead(II) removal were presented. These studies demonstrated that loofa sponge‐immobilized biomass of C. sorokiniana could be used as an efficient biosorbent for the treatment of lead(II) containing wastewater.
Xylitol Production from D‐Xylose at Different Oxygen Transfer Coefficients in a Batch Bioreactor
Authors: Winkelhausen E. , Amartey S.A. , Kuzmanova S.
Published: April 2004

Conversion of D‐xylose to xylitol by Candida boidinii NRRL Y‐17213 was studied under anaerobic and oxygen limited conditions by varying the oxygen transfer coefficient kLa. Shake flask experiments were used to provide the preliminary information required to perform experiments in a bioreactor. The yeast did not grow under fully anaerobic conditions, but anaerobic formations of xylitol, ethanol, ribitol, and glycerol were observed as well as D‐xylose assimilation of 11 %. In shake flasks, with an initial D‐xylose concentration of 50 g/L, an increase in kLa from 8 to 46 h–1 resulted in a faster growth, higher rate of substrate uptake and lower yields of products. The highest xylitol productivity (0.052 g/L h) was attained at kLa = 8 h–1. At kLa = 46 h–1, 98.6 % of D‐xylose was consumed and mainly converted to biomass. Using 130 g/L D‐xylose, kLa was varied in the fermenter from 26 to 78 h–1. The percentage of consumed D‐xylose increased from 31 % at kLa = 26 h–1 to 93–94 % at all other aeration levels. Biomass yield increased with kLa, whereas ethanol, ribitol, and glycerol yields exhibited an opposite dependence on the oxygenation level. The most favorable oxygen transfer coefficient for xylitol formation, in the fermenter, was kLa = 47 h–1 when its concentration (57.5 g/L) surpassed ethanol accumulation by 3.6‐fold, and the glycerol plus ribitol by 10‐fold. Concurrently, xylitol yield and productivity reached 0.45 g/g and 0.26 g/L h, respectively. The volumetric xylitol productivity was affected more by changes in the aeration than the corresponding yield.
Effects of the Little Ice Age on avalanche boulder tongues in the French Alps (Massif des Ecrins)
Authors: Jomelli Vincent , Pech Pierre
Published: April 2004

Lichens of the subspecies Rhizocarpon geographicum s.l were measured on 25 avalanche boulder tongues in the Massif des Ecrins to elucidate the Little Ice Age history of avalanche activity. Results show: (1) an increase of lichen size from the median to the distal zone of deposits, and a decrease from the edges to the centre; (2) three types of lichen settlement. From the uppermost to the median zone, lichens are absent, because avalanche activity is very active. Down‐slope, lichens occur in two different zones: the median zone is colonized by 5–20 mm size lichens on sides of blocks protected from the abrasional action of avalanches, while in the distal zone lichen diameters are largest (>30 mm) and occur on all sides of the blocks.

The spatial distribution of the lichens and their size according to elevation make it possible to distinguish different phases during which avalanche activity has increased. At high elevation, the avalanche activity was at a maximum before ad 1650 and between ad 1730 and 1830. During these two periods avalanches had sufﬁcient magnitude to reach the basal zone of the deposits. At low elevation since ad 1650 the magnitude and frequency of avalanches have declined. Copyright © 2004 John Wiley & Sons, Ltd.
Improving simple explicit methods for unsteady open channel and river flow
Authors: Burguete J. , García‐Navarro P.
Published: April 2004

A rigorous study of the explicit Lax–Friedrichs scheme for its application to one‐dimensional shallow water flows is presented. The deficiencies of this method are identified and the way to overcome them are presented. It is compared to the explicit first order upwind scheme and to the explicit second order Lax–Wendroff scheme by means of the simulation of several test cases with exact solution. All three schemes in their best balanced version are applied to the simulation of a real river flood wave leading to very satisfactory results. Copyright © 2004 John Wiley & Sons, Ltd.
On the application of slip boundary condition on curved boundaries
Authors: Behr Marek
Published: April 2004

Hydrodynamic simulations of sloshing phenomena often involve the application of slip boundary condition at the wetted surfaces. If these surfaces are curved, the ambiguous nature of the normal vector in the discretized problem can interfere with the application of such a boundary condition. Even the use of consistent normal vectors, preferred from the point of view of conservation, does not assure good approximation of the continuum slip condition in the discrete problem, and non‐physical recirculating flow fields may be observed. As a remedy, we consider the Navier slip condition, and more successfully, the so‐called BC‐free boundary condition. Copyright © 2004 John Wiley & Sons, Ltd.
Nutritional evaluation of some Nigerian wild seeds
Authors: Oboh Ganiyu , Ekperigin M. Mofoluso
Published: April 2004

Some wild seeds, namely Parkia biglobosa, Tetracarpidum conophorum, Pentaclethra macrophylla, Irvingia gabonensis, Afzelia africana, Prosporis africana and Monodora myristica, were randomly collected from various parts of Nigeria and analyzed with regard to their proximate, mineral, antinutrient composition and zinc bioavailability. The results revealed that the seeds had high protein (6.5–24.2%), fat (19.0–58.5%), mineral (Mg, Fe, Zn, Mn, Ca, Na, K, P) and phytate (1043.6–2905.2 mg/100 g) contents, while the cyanide content was low (3.7–6.4 mg/kg). However, Co, Pb and Ni were not detected in all the samples. The calculated [Ca] [phytate]/[Zn] molar ratios (which is the best index for predicting Zn bioavailability) for all the seeds revealed that Parkia biglobosa, Irvingia gabonensis and Prosporis africana had a calculated molar ratio above 0.50 mol/kg (critical level), thus indicating reduced bioavailability of Zn to a critical level. In view of the high fat, protein, mineral and low cyanide contents, the high phytate content would not be expected to reduce bioavailability of Zn in some of the wild seeds (Afzelia africana, Pentaclethra macrophylla and Monodora myristica). These wild seeds could be good nutrient sources if integrated fully into human and animal nutrition. However, further studies will be carried out on the protein quality and toxicological potentials of these wild seeds.
Moisture sorption characteristics of rice flour
Authors: Durakova Albena G. , Menkov Nikolay D.
Published: April 2004

Moisture equilibrium data (adsorption and desorption) of rice flour were determined using the static gravimetric method of saturated salt solutions at three storage temperatures: 10, 20 and 30°C. The range of water activities for each temperature was from 0.11 to 0.85. Equilibrium moisture content decreased with increase in storage temperature at any given water activity. The experimental data were fitted to four mathematical models (modified Oswin, modified Halsey, modified Chung‐Pfost and modified Henderson). The monolayer moisture content was estimated from sorption data using the Brunauer‐Emmett‐Teller (BET) equation. The isosteric heats of sorption were evaluated using Clausius‐Clapeyron equation.
Wheat flour confectionery products as a source of inorganic nutrients: Zinc and copper contents in hard biscuits
Authors: Šebečić Blaženka , Vedrina‐Dragojevic Irena
Published: April 2004

Cereal‐based confectionery products being consumed through whole human life are considered mainly to be a source of carbohydrates, that is energy, although cereals are a rich source of minerals as well. To evaluate some hard biscuits produced in Croatia as a source of different trace elements in nutrition, in this study Zn and Cu contents were determined in classic wheat flour biscuits and in dietetic biscuits enriched with whole wheat grain flour or whole wheat grain grits, soya flour and skimmed milk. Zn was determined by flame atomic absorption spectrometry (AAS); Cu was determined by inductively coupled plasma atomic emission spectroscopy (ICP‐AES). The results show that the Zn content in different kinds of biscuits ranges from 5.89 up to 17.64 mg/kg and the Cu content ranges from 1.15 up to 2.79 mg/kg depending on the type of wheat milling products and mineral content of other ingredients used. Enriched dietetic biscuits produced from wheat flour type 850 and whole wheat grain flour and/or soya flour and skimmed milk were almost 200% and 150% higher in Zn and Cu, respectively, in comparison to classic white wheat flour biscuits and can be considered as good sources of Zn and Cu in nutrition.
Scale and scope economies in nursing homes: A quantile regression approach
Authors: Christensen Eric W.
Published: April 2004

Nursing homes vary widely between facilities with very few beds and facilities with several hundred beds. Previous studies, which estimate nursing home scale and scope economies, do not account for this heterogeneity and implicitly assume that all nursing homes face the same cost structure. To account for heterogeneity, this paper uses quantile regression to estimate cost functions for skilled and intermediate care nursing homes. The results show that the parameters of nursing home cost functions vary significantly by output mix and across the cost distribution. Estimates show that product‐specific scale economies systematically increase across the cost distribution for both skilled and intermediate care facilities, with diseconomies of scale in the lower deciles and no significant scale economies in the higher deciles. As for ray scale economies, estimates show economies of scale in the lower deciles and diseconomies of scale or no significant scale economies at higher deciles. The estimates also show that scope economies exist in the lower cost deciles and that no scope economies exist in the higher cost deciles. Additionally, the degree of scope economies monotonically decreases across the deciles. Copyright © 2003 John Wiley & Sons, Ltd.