bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of low‐dose mitozantrone to treat aggressive multiple sclerosis: a single‐centre open‐label study using patient self‐assessment and clinical measures of multiple sclerosis status
Authors: Ostberg A. , Pittas F. , Taylor B.
Published: June 2005

Abstract

Background:  There is significant evidence supporting the use of mitozantrone in the treatment of multiple sclerosis (MS) but few data on the subtypes of MS that respond or which measures of disease status are most useful.

Aims:  To assess the efficacy of low‐dose (5 mg/m2 3 monthly) mitozantrone using patient self‐assessment questionnaire (SAQ), expanded disability status score (EDSS), multiple sclerosis functional composite score (MSFC), and the fatigue severity scale (FSS). Then, to compare the responses of a subgroup of relapsing remitting MS (RRMS) and secondary progressive MS (SPMS) patients to treatment, and to assess which measures of MS disease status are the most useful in a study of this type.

Method:  Thirty‐one patients with definite (McDonald criteria) active MS were commenced on mitozantrone 5 mg/m2 every 3 months. EDSS, MSFC and FSS data collected before treatment and after 12 months were analysed. The SAQ was administered after at least 12 months of therapy.

Results:  RRMS patients showed significantly more response to mitozantrone than SPMS patients in terms of MSFC (P = 0.02) and SAQ (P = 0.01).

Conclusions:  Low‐dose mitozantrone was well tolerated and useful in active RRMS in the short term; however, mitozantrone did not display any useful activity in SPMS patients over this time interval or at the mitozantrone dose used. Patient perception of treatment is a worthwhile outcome measure and the MSFC is the most useful objective measure of MS status change in this type of study. (Intern Med J 2005; 35: 382–387)
Delayed onset refractory dystonic movements following propofol anesthesia
Authors: SARAVANAKUMAR K. , VENKATESH P. , BROMLEY P.
Published: June 2005

Neuroexcitation is an uncommon but well recognized side effect of propofol anesthesia and sedation. We present a patient who, despite an intact mental status and without any preexisting movement disorder, experienced delayed onset of involuntary dystonic movements involving head, neck and shoulder for 11 h following emergence from propofol/nitrous oxide anesthesia.
Perioperative pharmacokinetics of ibuprofen enantiomers after rectal administration
Authors: KYLLÖNEN MATTI , OLKKOLA KLAUS T. , SEPPÄLÄ TIMO , RYHÄNEN PAULI
Published: June 2005

Background : Ibuprofen is a nonsteroidal anti‐inflammatory drug which has both peripheral and central analgesic effects. Ibuprofen has been shown to be an effective antipyretic and postoperative analgesic drug both in adults and children with few side effects. Pharmacokinetics of rectal ibuprofen has not been studied, although suppositories are frequently used for perioperative pain control in children.

Methods : There were four study groups: full‐term infants aged 1–7 weeks (n = 9), infants aged 8–25 weeks (n = 8), and infants aged 26–52 weeks (n = 7). Adult patients were 20–40 years old (n = 7). Ibuprofen suppository 20 mg·kg−1 was administered after induction of anesthesia. Blood samples were collected from 20 min to 10 h after dosing and pharmacokinetic analysis of ibuprofen enantiomers were done.

Results : Both ibuprofen enantiomers were detectable in blood in 20 min. Total ibuprofen plasma concentrations >10 mg·l−1 were seen from 40 min to 8 h. Values for Tmax of ibuprofen enantiomers and total ibuprofen were higher in the adult group than any of the infant groups (P < 0.05). In addition, values for physiological (standardized) t1/2 of (R)‐(−)‐ and (S)‐(+)‐ibuprofen were higher in infants aged 1–7 weeks than the adults (P < 0.05). None of the other pharmacokinetic variables, Cmax, AUC, chronological t1/2 or AUC ratio differed between the groups.

Conclusions : A single dose of ibuprofen suppository 20 mg·kg−1 after induction of anesthesia guarantees analgesic plasma concentrations during the early postoperative period. Except for the delayed absorption of ibuprofen in adults and higher physiological t1/2 in infants aged 1–7 weeks, no major pharmacokinetic differences were observed between study groups.
Giving parents written information about children's anesthesia: Are setting and timing important?
Authors: SPENCER CAROLINE , FRANCK LINDA S.
Published: June 2005

Background:  Research indicates that parents wish to receive more information and are anxious about anesthesia prior to their child's surgery.

Methods:  A pilot randomized controlled trial was conducted to ascertain if parents who received a general anesthesia information leaflet by post 1 week following their presurgical assessment clinic visit (n = 19) had greater knowledge, reduced anxiety, or greater satisfaction with anesthetic information on the day of surgery than parents who received the leaflet at the clinic visit (n = 21).

Results:  Parents had important knowledge deficits on the day of surgery, despite receiving the leaflet in addition to standard verbal communication. Parents who were given the leaflet at the presurgical assessment clinic had a modest 10% increase in knowledge compared with parents who received the leaflet by post. However, parents who received the leaflet within 2 weeks for their child's surgery also had 10% greater knowledge, regardless of the method of delivery. There were no differences in parental anxiety or satisfaction with the information related to method or timing of delivery. Parents appreciated receiving written information and a slight majority of parents (56%) preferred to receive the information at the presurgical assessment clinic visit.

Conclusions:  Parents have unmet information needs related to children's anesthetic care. Written information may improve parent knowledge and enhance satisfaction, but the setting and timing of information delivery are also important to consider.
Thoracoscopic repair of esophageal atresia with tracheoesophageal fistula: anesthetic and intensive care management of a series of eight neonates
Authors: KROSNAR SUZANNE , BAXTER ALISTAIR
Published: June 2005

Advances in minimally invasive techniques have made pediatric laparoscopic surgery commonplace. Thoracoscopic surgery in children however is still performed in only a few centers throughout the world. Between July 2001 and January 2004, the first eight esophageal atresia with tracheoesophageal fistula repairs were performed thoracoscopically at the Royal Hospital for Sick Children in Edinburgh. This article presents their anesthetic management, their postoperative management in the pediatric intensive care unit and reviews the complications seen in both the intraoperative and postoperative periods. Finally we discuss how our experience to date influences our perioperative management of these challenging cases.
Prolonged infusion of dexmedetomidine for sedation following tracheal resection
Authors: HAMMER GREGORY B. , PHILIP BRIDGET M. , SCHROEDER ALAN R. , ROSEN FREDERICK S. , KOLTAI PETER J.
Published: June 2005

Dexmedetomidine is a centrally acting alpha‐2 adrenergic agonist that is currently approved by the US Food and Drug Administration for short‐term use (≤24 h) to provide sedation in adults in the ICU. This drug has been shown to be efficacious in adult medical and surgical patients in providing sedation, anxiolysis, and analgesia. Dexmedetomidine has been associated with rapid onset and offset, hemodynamic stability, and a natural, sleep‐like state in mechanically ventilated adults. To date, there are few publications of the use of this drug in children, and prolonged infusion has not been described. We report our use of dexmedetomidine in a child during a 4‐day period of mechanical ventilation following tracheal reconstruction for subglottic stenosis.
Investigation Into Sleep Disturbance of Patients Suffering from Cluster Headache
Authors: Nobre ME , Leal AJ , Filho PMF
Published: June 2005

The new discoveries relating to cluster headache (CH) encouraged the study of the relationship of the hypothalamus to respiratory physiology and its comorbidity with sleep apnoea. The question is whether the apnoeas are more frequent during REM sleep and the desaturations could be involved as triggers of the cluster attacks. Furthermore, could the connection with the hypothalamus, already proved, be responsible for an alteration in the structure of REM sleep and a chemoreceptor dysfunction. We set out to analyse when polysomnography investigation is necessary in patients with CH. We studied 37 patients suffering from episodic CH, 31 (83.8%) men and six (16.2%) women. For the control group, we selected 35 individuals, 31 (88.6%) men and four (11.4%) women. There was a greater percentage of obstructive sleep apnoea (OSA) in patients with CH (58.3%) compared with the control group (14.3%) and with the general population (2-4%). In cases of pain during sleep, the majority is deflagrated during the REM phase, following a desaturation episode. A stratified analysis of the apnoea/hypnoea index relating to body mass index (BMI) and age showed that patients with CH have 8.4 times more chance of exhibiting OSA than normal individuals ( P < 0001). This risk increases to 24.38 in patients with a BMI > 25 kg/m2 and increases to 13.5 in patients > 40 years old. Surprisingly, the risk decreases sharply in patients with a BMI < 25 kg/m2 and who are < 40 years old. Due to the fact that polysomnography is a complex, costly and sometimes difficult examination, we suggest, in concordance with the results, that it should be carried out routinely in patients with CH that exhibit a BMI of > 25 kg/m2 and/or in patients who are > 40 years of age.
Psychiatric Comorbidity in the Evolution From Migraine to Medication Overuse Headache
Authors: Radat F , Creac'h C , Swendsen JD , Lafittau M , Irachabal S , Dousset V , Henry P
Published: June 2005

We set out to study the role of psychiatric comorbidity in the evolution of migraine to medication overuse headache (MOH) by a comparative study of 41 migraineurs (MIG) and 41 patients suffering from MOH deriving from migraine. There was an excess risk of suffering from mood disorders [odds ratio (OR) = 4.5, 95% confidence interval (CI) 1.5, 13.5], anxiety (OR = 5, 95% CI 1.2, 10.7) and disorders associated with the use of psychoactive substances other than analgesics (OR = 7.6, 95% CI 2.2, 26.0) in MOH compared with MIG. Retrospective study of the order of occurrence of disorders showed that in the MOH group, psychiatric disorders occurred significantly more often before the transformation from migraine into MOH than after. There was no crossed-family transmission between MOH and psychiatric disorders, except for substance-related disorders. MOH patients have a greater risk of suffering from anxiety and depression, and these disorders may be a risk factor for the evolution of migraine into MOH. Moreover, MOH patients have a greater risk of suffering from substance-related disorders than MIG sufferers. This could be due to the fact that MOH is part of the spectrum of addictive disorders.
When Should an Epidural Blood Patch be Performed in Postlumbar Puncture Headache? A Theoretical Approach Based on a Cohort of 79 Patients
Authors: Vilming ST , Kloster R , Sandvik L
Published: June 2005

The aim of the present study was to decide on which day in the course of postlumbar puncture headache (PPH) an epidural blood patch (EBP) should be performed to minimize suffering. A cohort of 79 patients (64 female, 15 male) was followed prospectively for 14 days and the consequences of performing an EBP on different days were studied. If no EBP was performed, the patients would accumulate 141 days with PPH5 (bedridden most of the day), 216 days with PPH4-5 (bedridden more than half the day), and 293 days with PPH3-5 (bedridden half the day or more). If these patients were patched on day 2, 3 or 4 after an initial observation of the PPH grade on day 1, the expected suffering was substantially reduced, and the more the earlier in the course the EBP was performed. If the strategy was to treat only patients with PPH5 with an expected 90% success rate, the reduction compared with no treatment was 50% if treated on day 2, 37% if treated on day 3, and 29% if treated on day 4. The corresponding figures for treating patients with PPH4-5 was a 51, 44 and 29% reduction, and for PPH3-5 the reduction was 62, 49 and 35%, respectively. Irrespective of strategy, the expected reduction of suffering in the cohort was greatest when the EBP was performed early in the course of PPH. It is suggested that the decision to perform an EBP should be made at an early stage and offered to patients who have to lie in bed for more than half a day despite conservative treatment.
The Impact of Migraine on Epilepsy: A Prospective Prognosis Study
Authors: Velioglu SK , Boz C , Özmenoglu M
Published: June 2005

The effect of migraine on the prognosis of epilepsy has not been reported. The aim of this prospective 5-10-year follow-up study was to examine some outcome measures and the cumulative probability of being seizure-free in epilepsy patients with migraine, and to compare their results with those of epilepsy patients without migraine. Fifty-nine patients (40 women; mean age 25 years) were diagnosed with both epilepsy and migraine (EM group). The control group consisted of 56 patients with epilepsy but without migraine (E group). Both groups were recruited and followed up over similar periods. We compared the outcome variables in the EM group with those in the E group. Kaplan-Meier methods were used to assess the seizure-free curves. The EM group had a significantly lower cumulative probability of being seizure-free over 10 years compared with the E group. The other epilepsy outcome measures at follow-up differed significantly between the groups, with the EM group having a longer duration of epilepsy, a lower early treatment response, and a higher incidence of intractable epilepsy and achieving remission with polytherapy, and more seizure control and medication problems for at least the last 2 years of follow-up. Comorbid migraine had a negative effect on the prognosis of epilepsy.
A site‐specific insertion sequence in flax genotrophs induced by environment
Authors: Chen Yiming , Schneeberger Richard G. , Cullis Christopher A.
Published: June 2005

• A single‐copy 5.7 kilobase (kb) DNA fragment, termed Linum Insertion Sequence 1 (LIS‐1), has been identified and characterized. This is one of the DNA changes associated with the environmentally induced heritable changes resulting in stable lines termed genotrophs in flax (Linum usitatissimum).

• The insertion sequence and its insertion site have been cloned from genomic libraries and sequenced. PCR products across the insertion and surrounding regions have also been cloned and sequenced.

• The 5.7 kb DNA fragment is inserted into a 3.7 kb EcoRI fragment in the plastic line (Pl) with the generation of a 3 base pair duplication at the insertion site, as well as additional sequence changes. The identical insertion was also found in other genotrophs and flax varieties. The intact element was not present in Pl but appeared to be generated by a reproducible series of complex rearrangements or insertion events.

• LIS‐1 is the result of a targeted, highly specific, complex insertion event that occurs during the formation of some of the genotrophs, and occurs naturally in many flax and linseed varieties.
Patterns of introgression across an expanding hybrid zone: analysing historical patterns of gene flow using nonequilibrium approaches
Authors: Cruzan Mitchell B.
Published: June 2005

Previous studies suggest that the hybrid zone between two taxa in thePiriqueta carolinianacomplex in central Florida (south‐eastern North America) has recently expanded with hybrids replacing parental genotypes across a broad region of the Florida peninsula.

Here I use patterns of genetic disequilibria and levels of differentiation among populations to infer historical patterns of introgression across this broad hybrid zone.

There were strong positive associations among taxon‐specific alleles at the southern extent of hybridization, but disequilibria values were close to zero across the central and northern portions of the hybrid zone. Levels of among‐population differentiation in the central portion of the hybrid zone were relatively low, and increased towards the northern extent of hybridization.

The high levels of disequilibria are coincident with the sharp clines at the southern end of the hybrid zone, suggesting that there is a tension zone in this region that is maintained by selection against hybrids and dispersal from parental regions. The levels of disequilibria within populations and patterns of differentiation among populations are consistent with historical introgression and northward expansion of this hybrid zone, which may have slowed or ceased in recent generations.
Entrepreneurial Learning: Researching the Interface between Learning and the Entrepreneurial Context
Authors: Harrison Richard T. , Leitch Claire M.
Published: June 2005

The context for the research presented in this article arises from increasing interest, by academics and practitioners, in the importance of learning and knowledge in the knowledge–based economy. In particular, we consider the scope for applying concepts of learning within the field of entrepreneurship. While it has gained currency within the field of management, the application of these concepts to entrepreneurship has been limited. In this Introduction to the Special Issue, we review the development of the field of entrepreneurship as a context for the emergence of learning as an area of scholarly attention, summarize a number of key themes emerging from the organizational learning literature, and outline the article selection process and summarize the key elements of each of the included articles. The article concludes with some reflections on future research at the interface between learning and the entrepreneurial context.
When Do Venture Capital Firms Learn from Their Portfolio Companies?
Authors: De Clercq Dirk , Sapienza Harry J.
Published: June 2005

In this study, we examine when venture capital firms (VCFs) learn from their portfolio companies (PFCs). Relying primarily on learning and behavioral theories, we develop hypotheses regarding the effects of prior experience, knowledge overlap, trust, and PFC performance on learning by VCFs. We use a combination of primary and secondary data from 298 U.S.–based VCFs to test the hypotheses. Interview data are used to illuminate the results and to guide our discussion of implications.

 Many of our results were surprising. For example, we found that the VCF's overall experience is negatively related to VCF learning, and we found that trust in VCF–PFC dyads is also negatively associated with VCF learning. Whereas we expected to observe a curvilinear relationship between knowledge overlap and learning, we found that lower levels of knowledge overlap were associated with greater learning in a linear fashion. Finally, we found that VCFs perceive greater learning to occur in higher–performing PFCs. We discuss the limitations and implications of our findings and also suggest avenues for future research.
A CGE analysis of trade costs in the Russian agrofood sector
Authors: Kuhn Arnim
Published: June 2005

Ten years after the end of central planning, enormous interregional price differences indicate that Russian food markets are not well integrated spatially. Trade potentials are thus not exploited, most probably because of high trade costs. Besides transport costs, transaction costs seem to play an important role as an impediment to interregional arbitrage. These transaction costs can be very high in transition countries due to underdeveloped market structures and weak public institutions. After subtracting transport costs from interregional price differences, large differences remain, particularly in the case of high‐value products. It is assumed that these residual price differences constitute the transaction cost component of total trade costs. The regional economic impact of different trade cost components is quantified using a bi‐regional computable general equilibrium (CGE) model. Simulations show that the results are quite different between the two stylized regions (East and West), depending on which trade cost component is reduced. While the welfare effects of varying customs tariffs and transport margins are rather limited, lower transaction costs of trade seem to be a promising way to achieve a better functioning food market in Russia.
Output, prices, and the distribution of consumption in rural India
Authors: Bell Clive , Klonner Stefan
Published: June 2005

This article analyzes the relation among agricultural output, inflation, and the distribution of consumption in rural India, using both the Singh–Maddala and Dagum families to model the entire distribution parametrically. Employing a benchmark case in which growth is distributionally neutral and idiosyncratic shocks are completely smoothed, and using a GMM‐estimator to deal with potential simultaneity between output and consumption, we conclude that: (i) growth was not distributionally neutral; (ii) good harvests (relative to trend) yielded improvements according to first‐order stochastic dominance; (iii) slow growth before 1980 went with decreasing inequality; (iv) accelerated growth thereafter tended to increase inequality, though yielding improvements according to first‐order stochastic dominance; (v) consumption smoothing was incomplete.
Environmental impacts of technological change in Bangladesh agriculture: farmers' perceptions, determinants, and effects on resource allocation decisions
Authors: Rahman Sanzidur
Published: June 2005

This article measures the impact of modern technology adoption in raising farmers' environmental awareness and the impact of farmers' environmental awareness on resource use by utilizing survey data from 21 villages in three agro‐ecological regions of Bangladesh. The econometric analysis is based on the application of the Tobit model explaining farmers' environmental awareness in the first stage and a profit function examining environmental awareness and resource use relationships in the second stage. Results reveal that the “level” and “duration” of involvement with modern technology raises farmers' environmental awareness, and that farmers' environmental awareness reduces resource use including chemicals. Farmers, who are aware of the adverse environmental impacts of modern agricultural technology, use lower amounts of all inputs in order to avoid further environmental damage. Therefore, efforts to raise farmers' environmental awareness are expected to enhance intangible benefits accruing from a relatively less chemical‐intensive environment.
Substrate positioning by His92 is important in catalysis by purple acid phosphatase
Authors: Funhoff Enrico G. , Wang Yunling , Andersson Goran , Averill Bruce A.
Published: June 2005

Proteolysis of single polypeptide mammalian purple acid phosphatases (PAPs) results in the loss of an interaction between the loop residue Asp146 and the active site residues Asn91 and/or His92. While Asn91 is a ligand to the divalent metal of the mixed‐valent di‐iron center, the role of His92 in the catalytic mechanism is unknown. Site‐directed mutagenesis of His92 was performed to examine the role of this residue in single polypeptide PAP. Conversion of His92 into Ala, which eliminates polar interactions of this residue with the active site, resulted in a 10‐fold decrease in catalytic activity at the optimal pH. Conversely, conversion of this residue into Asn, which cannot function as either a proton donor or acceptor, but can provide hydrogen–bonding interactions, resulted in a three‐fold increase in activity at the optimal pH. Both mutant enzymes had more acidic pH optima, with pKes,1 values consistent with the involvement of an iron(III) hydroxide unit or a hydroxide in the second coordination sphere in catalysis. These results, together with EPR data, support a role of His92 in positioning either the nucleophile or the substrate, rather than directly in acid or base catalysis. The existence of an extensive hydrogen‐bonding network that could fine‐tune the position of His92 is consistent with this proposal.
Slc12a2 is a direct target of two closely related homeobox proteins, Six1 and Six4
Authors: Ando Zen‐ichi , Sato Shigeru , Ikeda Keiko , Kawakami Kiyoshi
Published: June 2005

Six genes are homologs of Drosophila sine oculis and encode transcription factors that are characterized by a conserved Six domain and homeodomain. Of the six family members (Six1–Six6) in mice, Six1 and Six4 show similar expression patterns during embryogenesis. Six1–/– mice show defective formation of various organs such as inner ear, nose, skeletal muscle, kidney and thymus, whereas Six4–/– mice show little anomaly in organogenesis. To understand the molecular basis for the differential function of Six1 and Six4 in vivo, we screened target genes of Six1 and Six4 and found that Six1 and Six4 differentially regulated a set of target genes. Gel‐retardation assays indicated that the promoter region of one of the targets, sodium–potassium–chloride cotransporter 1 (Slc12a2), contains multiple Six1‐binding sites and one common binding site of Six1 and Six4, suggesting that the DNA‐binding specificity of Six1 is distinct from that of Six4. This underlies the differential regulation of common target genes by Six1 and Six4. Furthermore, in situ hybridization demonstrated that the expression of Slc12a2 was reduced in the developing dorsal root ganglia of Six1–/–/Six4–/– mice, suggesting that Six1 and Six4 regulate Slc12a2 in vivo.
Two short protein domains are responsible for the nuclear localization of the mouse spermine oxidase µ isoform
Authors: Bianchi Marzia , Amendola Roberto , Federico Rodolfo , Polticelli Fabio , Mariottini Paolo
Published: June 2005

In mouse, at least two catalytically active splice variants (mSMOα and mSMOµ) of the flavin‐containing spermine oxidase enzyme are present. We have demonstrated previously that the cytosolic mSMOα is the major isoform, while the mSMOµ enzyme is present in both nuclear and cytoplasmic compartments and has an extra protein domain corresponding to the additional exon VIa. By amino acid sequence comparison and molecular modeling of mSMO proteins, we identified a second domain that is necessary for nuclear localization of the mSMOµ splice variant. A deletion mutant enzyme of this region was constructed to demonstrate its role in protein nuclear targeting by means of transient expression in the murine neuroblastoma cell line, N18TG2.
Allosteric functioning of dimeric class C G‐protein‐coupled receptors
Authors: Pin J‐P. , Kniazeff J. , Liu J. , Binet V. , Goudet C. , Rondard P. , Prézeau L.
Published: June 2005

Whereas most membrane receptors are oligomeric entities, G‐protein‐coupled receptors have long been thought to function as monomers. Within the last 15 years, accumulating data have indicated that G‐protein‐coupled receptors can form dimers or even higher ordered oligomers, but the general functional significance of this phenomena is not yet clear. Among the large G‐protein‐coupled receptor family, class C receptors represent a well‐recognized example of constitutive dimers, both subunits being linked, in most cases, by a disulfide bridge. In this review article, we show that class C G‐protein‐coupled receptors are multidomain proteins and highlight the importance of their dimerization for activation. We illustrate several consequences of this in terms of specific functional properties and drug development.
The study of G‐protein coupled receptor oligomerization with computational modeling and bioinformatics
Authors: Filizola Marta , Weinstein Harel
Published: June 2005

To achieve a structural context for the analysis of G‐protein coupled receptor (GPCR) oligomers, molecular modeling must be used to predict the corresponding interaction interfaces. The task is complicated by the paucity of detailed structural data at atomic resolution, and the large number of possible modes in which the bundles of seven transmembrane (TM) segments of the interacting GPCR monomers can be packed together into dimers and/or higher‐order oligomers. Approaches and tools offered by bioinformatics can be used to reduce the complexity of this task and, combined with computational modeling, can serve to yield testable predictions for the structural properties of oligomers. Most of the bioinformatics methods take advantage of the evolutionary relation that exists among GPCRs, as expressed in their sequences and measurable in the common elements of their structural and functional features. These common elements are responsible for the presence of detectable patterns of motifs and correlated mutations evident from the alignment of the sequences of these complex biological systems. The decoding of these patterns in terms of structural and functional determinants can provide indications about the most likely interfaces of dimerization/oligomerization of GPCRs. We review here the main approaches from bioinformatics, enhanced by computational molecular modeling, that have been used to predict likely interfaces of dimerization/oligomerization of GPCRs, and compare results from their application to rhodopsin‐like GPCRs. A compilation of the most frequently predicted GPCR oligomerization interfaces points to specific regions of TMs 4–6.
Methods to monitor the quaternary structure of G protein‐coupled receptors
Authors: Milligan Graeme , Bouvier Michel
Published: June 2005

A wide range of approaches has been applied to examine the quaternary structure of G protein‐coupled receptors, the basis of such protein–protein interactions and how such interactions might modulate the pharmacology and function of these receptors. These include coimmunoprecipitation, various adaptations of resonance energy transfer techniques, functional complementation studies and the analysis of ligand‐binding data. Each of the available techniques has limitations that restrict interpretation of the data. However, taken together, they provide a coherent body of evidence indicating that many, if not all, G protein‐coupled receptors exist and function as dimer/oligomers. Herein we assess the widely applied techniques and discuss the relative benefits and limitations of these approaches.
Conformational properties of bacterial DnaK and yeast mitochondrial Hsp70
Authors: Moro Fernando , Fernández‐Sáiz Vanesa , Slutsky Olga , Azem Abdussalam , Muga Arturo
Published: June 2005

Among the eukaryotic members of the Hsp70 family, mitochondrial Hsp70 shows the highest degree of sequence identity with bacterial DnaK. Although they share a functional mechanism and homologous co‐chaperones, they are highly specific and cannot be exchanged between Escherichia coli and yeast mitochondria. To provide a structural basis for this finding, we characterized both proteins, as well as two DnaK/mtHsp70 chimeras constructed by domain swapping, using biochemical and biophysical methods. Here, we show that DnaK and mtHsp70 display different conformational and biochemical properties. Replacing different regions of the DnaK peptide‐binding domain with those of mtHsp70 results in chimeric proteins that: (a) are not able to support growth of an E. coli DnaK deletion strain at stress temperatures (e.g. 42 °C); (b) show increased accessibility and decreased thermal stability of the peptide‐binding pocket; and (c) have reduced activation by bacterial, but not mitochondrial co‐chaperones, as compared with DnaK. Importantly, swapping the C‐terminal α‐helical subdomain promotes a conformational change in the chimeras to an mtHsp70‐like conformation. Thus, interaction with bacterial co‐chaperones correlates well with the conformation that natural and chimeric Hsp70s adopt in solution. Our results support the hypothesis that a specific protein structure might regulate the interaction of Hsp70s with particular components of the cellular machinery, such as Tim44, so that they perform specific functions.
Variational mechanics in one and two dimensions
Authors: Hanc Jozef , Taylor Edwin F. , Tuleja Slavomir
Published: June 2005

We develop heuristic derivations of two alternative principles of least action. A particle moving in one dimension can reverse direction at will if energy conservation is the only criterion. Such arbitrary changes in the direction of motion are eliminated by demanding that the Maupertuis–Euler abbreviated action, equal to the area under the momentum versus position curve in phase space, has the smallest possible value consistent with conservation of energy. Minimizing the abbreviated action predicts particle trajectories in two and three dimensions and leads to the more powerful Hamilton principle of least action, which not only generates conservation of energy, but also predicts motion even when the potential energy changes with time. Introducing action early in the physics program requires modernizing the current obscure and confusing terminology of variational mechanics.
Superluminal apparent motions in distant radio sources
Authors: Chodorowski Michał J.
Published: June 2005

We derive the prediction of the standard model of superluminal radio sources for the apparent transverse velocity of a radio source located at redshift z. The apparent velocity of the source is reduced by a factor of 1+z compared to that of a similar nearby source. The cause of this reduction is recession of the distant source due to the expansion of the universe. The apparent velocity of a source can be estimated from its redshift and proper motion using the values of the Hubble constant and the mean densities of different energy components in the universe. We derive an expression for the velocity valid for the currently favored cosmological model: a flat universe with a nonzero cosmological constant.
The appearance, apparent speed, and removal of optical effects for relativistically moving objects
Authors: Deissler Robert J.
Published: June 2005

Because various parts of an object are different distances from an observer, and light takes a finite time to reach the observer, the appearance of a relativistically moving object will be very different from that given by the Lorentz contraction. We derive equations that can be applied to a photographic image so that the Lorentz contraction can still be observed. We also give equations that quantify the apparent deformation of the object and plots that show the apparent speed of the object as a function of time. In particular, as an object approaches, its apparent speed can be much greater than the speed of light. In addition, we derive equations that can be applied to photographic images to show how a relativistically moving image will appear. This transformation is applied to photographic images that demonstrate the changes in appearance of a relativistically moving object. The dominate effect is that of appearing to be rotated, that is, the Terrell effect.
Molecular and spin dynamics simulations using modern integration methods
Authors: Tsai Shan-Ho , Lee H. K. , Landau D. P.
Published: June 2005

Decomposition algorithms have proven useful for molecular dynamics and spin dynamics simulations of many-body systems. These methods are time reversible, symplectic, and the error in the total energy is bounded. In general, these techniques are accurate for much larger time steps than more standard integration methods. We review these decomposition algorithms and illustrate their performance for simulations of a Heisenberg ferromagnet.
Complementary Process to Response Bias in the Centromedian Nucleus of the Thalamus
Authors: Minamimoto Takafumi , Hori Yukiko , Kimura Minoru
Published: June 2005

Activity in several areas of the human brain and the monkey brain increases when a subject anticipates events associated with a reward, implicating a role for bias of decision and action. However, in real life, events do not always appear as expected, and we must choose an undesirable action. More than half of the neurons in the monkey centromedian (CM) thalamus were selectively activated when a small-reward action was required but a large-reward option was anticipated. Electrical stimulation of the CM after a large-reward action request substituted a brisk performance with a sluggish performance. These results suggest involvement of the CM in a mechanism complementary to decision and action bias.
Nature's Beauty and Haeckel's Talents
Authors: Laubichler Manfred
Published: June 2005

Proteus
. A Nineteenth Century Vision.
By David Lebrun
. First Run/Icarus Films, New York, 2004. 61 minutes.
www.frif.com/new2004/pro.html

Centered around Ernst Haeckel, this film touches on life in the deep seas, 19th-century oceanography, and a series of dualities: science and art, materialism and religion, rationality and mysticism, and the outer world and the inner psyche.
Twenty five year mortality and air pollution: results from the French PAARC survey
Authors: Filleul L , Rondeau V , Vandentorren S , Le Moual N , Cantagrel A , Annesi-Maesano I , Charpin D , Declercq C , Neukirch F , Paris C , Vervloet D , Brochard P , Tessier J-F , Kauffmann F , Baldi I
Published: June 2005

Aims and Methods:Long term effects of air pollution on mortality were studied in 14 284 adults who resided in 24 areas from seven French cities when enrolled in the PAARC survey (air pollution and chronic respiratory diseases) in 1974. Daily measurements of sulphur dioxide, total suspended particles, black smoke, nitrogen dioxide, and nitric oxide were made in 24 areas for three years (1974–76). Cox proportional hazards models controlling for individual confounders (smoking, educational level, body mass index, occupational exposure) were applied, and frailty models used to take into account spatial correlation. Indicators of air pollution were the mean concentration.

Results:Models were run before and after exclusion of six area monitors influenced by local traffic (NO/NO2>3 in ppb). After exclusion of these areas, analyses showed that adjusted risk ratios (95% CI) for TSP, BS, NO2, and NO for non-accidental mortality were 1.05 (1.02 to 1.08), 1.07 (1.03 to 1.10), 1.14 (1.03 to 1.25), and 1.11 (1.05 to 1.17) for 10 μg/m3respectively. Consistent patterns for lung cancer and cardiopulmonary causes were observed.

Conclusions:Urban air pollution assessed in the 1970s was associated with increased mortality over 25 years in France.
Mortality in the UK industrial silica sand industry: 1. Assessment of exposure to respirable crystalline silica
Authors: Brown T P , Rushton L
Published: June 2005

Aims:To develop a job-exposure matrix (JEM) from personal and static respirable crystalline silica (RCS) measurements in UK industrial silica sand workers.

Methods:A total of 2429 personal and 583 static RCS dust samples were collected using cyclone samplers at seven UK quarries between 1978 and 2000. These data were combined, and analysis of variance using general linear models was used to evaluate the effect of quarry, job, and year on RCS concentrations, and facilitate the creation of five quarry and three time categories with similar exposure levels by comparing the least-square GM RCS concentrations.

Results:The overall geometric mean (GM) RCS concentration was 0.09 mg/m3(geometric standard deviation 3.9). Silica flour and dry job categories tended to have the highest RCS exposure and 13.3% of all samples exceeded the UK maximum exposure level of 0.3 mg/m3. RCS levels generally decreased over time.

Conclusions:Data have been collected and used to develop a JEM for UK industrial silica sand workers between 1978 and 2000. Although there were some limitations in the data and certain assumptions were made, the use of available data to estimate exposure quantitatively is an improvement over the use of qualitative and surrogate measures of exposure. The continual collection of dust measurements in the industry is essential to facilitate the exploration of exposure-response relations that may exist between silica and silicosis, lung cancer, and other diseases.
GRAVITY TESTS IN THE SOLAR SYSTEM AND THE PIONEER ANOMALY
Authors: JAEKEL MARC-THIERRY , REYNAUD SERGE
Published: June 2005

We build up a new phenomenological framework associated with a minimal generalization of Einsteinian gravitation theory. When linearity, stationarity and isotropy are assumed, tests in the solar system are characterized by two potentials which generalize respectively the Newton potential and the parameter γ of parametrized post-Newtonian formalism. The new framework has the capability to account for the Pioneer anomaly while preserving the compatibility of other gravity tests with general relativity.
LOOP VARIABLES AND THE INTERACTING OPEN STRING IN A CURVED BACKGROUND
Authors: SATHIAPALAN B.
Published: June 2005

Applying the loop variable proposal to a sigma model (with boundary) in a curved target space, we give a systematic method for writing the gauge and generally covariant interacting equations of motion for the modes of the open string in a curved background. As in the free case described in an earlier paper, the equations are obtained by covariantizing the flat space (gauge invariant) interacting equations and then demanding gauge invariance in the curved background. The resulting equation has the form of a sum of terms that would individually be gauge invariant in flat space or at zero interaction strength, but mix amongst themselves in curved space when interactions are turned on. The new feature is that the loop variables are deformed so that there is a mixing of modes. Unlike the free case, the equations are coupled, and all the modes of the open string are required for gauge invariance.
ANALYSIS OF CORRELATION BETWEEN AIMING ADJUSTMENT TRAJECTORY AND TARGET
Authors: LIN KUO-BIN , HWANG CHI-KUANG
Published: June 2005

In archery, there is the relationship among stability of the archer, adjustments made during the aiming procedure, and the targeting coordination. Twelve specialists from the male archery team of National College of Physical Education and Sports took part in this research, with 12 arrows sets up at a distance of 70 m. A laser pen is located on the bow handle for capturing the trajectory of the aiming procedure with a digital video camera, and the other camera for the coordination of target. The Ariel Performance Analysis System motion analysis system is used to obtain the x and y aiming trajectory coordinates for analyzing the correlation. Results of this research were: (1) Ten archers whose variation of the x axis is larger than that of the y axis. (2) There are four archers whose aiming adjustment procedure has all the positive correlation with the target in the x axis, but there are three archers with all negative correlation. (3) In terms of the correlation in the y axis, there are six archers with all positive correlation, but there are two archers with all negative correlation.
PERFORMANCE MEASUREMENT OF TENNIS EQUIPMENT
Authors: MILLER STUART
Published: June 2005

Equipment is exerting an increasing influence on the nature of tennis. The International Tennis Federation (ITF) Technical Centre was set up to ensure that the challenge and identity of the game is retained, while not discouraging technological innovation. As the physiological characteristics of the player are not under its control, the Technical Centre must pursue its mission through the understanding and control of equipment. This requires systematic testing to establish its characteristics, and research and development projects to identify methods of measuring those characteristics that are not currently covered by the Rules of Tennis. This paper describes tests, test methods and current research programs that the ITF has devised to measure the performance of tennis equipment. Although tennis balls are currently tested for size, mass, compression and rebound, two further variables are being researched to more fully specify its characteristics: dynamic coefficient of restitution and aerodynamics (lift and drag). The former project has suggested an inverse second-order relationship between coefficient of restitution and impact speed. A racket performance machine is described, which is designed to replicate the impact characteristics of tennis serves, and which will be used to benchmark the performance characteristics of tennis rackets. Initial results demonstrate the relationship between "power" and both impact speed and impact location. Surfaces, too, play an important role in determining ball rebound characteristics. A test that measures the frictional interaction between the ball and surface during impact, which is converted to a measure of surface "space" is described. The results of these projects will allow the ITF, in its role as guardian of the game, to make informed decisions on the rules relating to equipment, and help ensure that tennis retains its identity.
MOMENTUM TRANSFER OF UPPER EXTREMITY IN TENNIS ONE-HANDED BACKHAND DRIVE
Authors: WANG LIN-HWA , LIN HWAI-TING
Published: June 2005

Study Design: Linear momentum and angular momentum in trunk and upper extremity segments in one-handed backhand drive were calculated.

Objective: To investigate the characteristics and transfer of linear momentum and angular momentum from the trunk and upper extremity to racket during tennis one-handed backhand drive.

Background: Backhand stroke is one of the most frequently used techniques in playing tennis. Very few studies have taken the point of view from the transfer linear and angular momentum of the trunk and upper extremity to racket during tennis one-handed backhand drive.

Methods: Six right-handed elite male tennis players participated in this study. Mean age was 26 ± 2.71 years. Sixteen markers were attached on the selected anatomic landmarks unilaterally and three markers attached on the racket to define the coordinate system of the trunk, upper arm, forearm, hand, and racket.

Results: Hand contributed the most force for the changes of both linear momentum (leading and vertical direction) and angular momentum (supination). Racket and hand had similar curves in the three directions, which shows the main control racket is from hand and obvious effect in one-handed backhand stroke performance.

Conclusions: An understanding of kinetics of the backhand stroke is essential for understanding injury mechanisms and prevention.
BIOMECHANICAL STUDY ON A NEW TRAINING MACHINE AND METHOD FOR POWER AND STRENGTH
Authors: CHEN CHUAN-SHOW
Published: June 2005

Strength and power are important in sports competition, and increasing ability of explosive muscle contraction force is key to winning for sports performance in events like jumping or throwing.

In this study, Passive Repeated Plyometric (PRP) training method and the machine were designed. This machine allow one to training for top gear power with high frequency and without danger as compared with the conventional way of training like common way of plyomerics or using machine for isotonic muscle contraction. The PRP has it specific effects, which can be summarized as follow:

1. Motor driving PRP machine allow athlete training with high frequency, up to 300 rpm (0.2 Hz), especially for lower extremities to increase thrust force and force of body trunk.

2. PRP training method bring about the stretching reflex and elastic energy to recruit into a powerful muscle contraction.

3. This training machine formed a natural and powerful muscle contraction by stretching and shortening in a cycle of contraction, which is called stretching-shortening cycle or SSC.

4. Well-documented evidence from both theoretical and practical were achieved in 1998 Bangkok Asian game and the following Pusan2002 applying to track & field and basketball players.