bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggravated Lyme Carditis in CD11a−/−and CD11c−/−Mice
Authors: Guerau-de-Arellano Mireia , Alroy Joseph , Bullard Daniel , Huber Brigitte T.
Published: October 2005

CD18 hypomorph mice expressing reduced levels of the common β2 integrin chain develop aggravated Lyme carditis, compared to that developed by wild-type (WT) mice, upon infection with the spirocheteBorrelia burgdorferi. The enhancement of Lyme carditis in these mice is characterized by increased macrophage infiltration, correlating with augmented expression of the monocyte/macrophage chemoattractant protein 1 (MCP-1). The lack of CD18 results in the deficiency of all β2 integrins, i.e., CD11a/CD18 (LFA-1), CD11b/CD18 (Mac-1/CR3), CD11c/CD18 (p150,95/CR4), and CD11d/CD18. To determine the roles of the various β2 integrins in controlling the development of aggravated Lyme carditis, disease induction was analyzed in CD11a−/−, CD11b−/−, and CD11c−/−mice. CD11a−/−and CD11c−/−mice, but not CD11b−/−mice, developed aggravated Lyme carditis after exposure toB. burgdorferi. Similarly to CD18 hypomorph mice, CD11c−/−mice expressed higher levels of MCP-1, compared to both WT and CD11a−/−mice, as determined by in vitro analysis of MCP-1 secretion by bone marrow-derived dendritic cells and in vivo analysis of MCP-1 mRNA expression inB. burgdorferi-infected hearts. On the other hand, CD11a deficiency was associated with heightened heartB. burgdorferiburden relative to that of WT mice. Overall, our results suggest that the increased severity of Lyme carditis in CD18 hypomorph mice is caused by deficiency in CD11a or CD11c, possibly via different mechanisms.
Role of Motility in the Colonization of Uropathogenic
Escherichia coli
in the Urinary Tract
Authors: Lane M. Chelsea , Lockatell Virginia , Monterosso Greta , Lamphier Daniel , Weinert Julia , Hebel J. Richard , Johnson David E. , Mobley Harry L. T.
Published: October 2005

Uropathogenic
Escherichia coli
(UPEC) causes most uncomplicated urinary tract infections (UTIs) in humans. Flagellum-mediated motility and chemotaxis have been suggested to contribute to virulence by enabling UPEC to escape host immune responses and disperse to new sites within the urinary tract. To evaluate their contribution to virulence, six separate flagellar mutations were constructed in UPEC strain CFT073. The mutants constructed were shown to have four different flagellar phenotypes:
fliA
and
fliC
mutants do not produce flagella; the
flgM
mutant has similar levels of extracellular flagellin as the wild type but exhibits less motility than the wild type; the
motAB
mutant is nonmotile; and the
cheW
and
cheY
mutants are motile but nonchemotactic. Virulence was assessed by transurethral independent challenges and cochallenges of CBA mice with the wild type and each mutant. CFU/ml of urine or CFU/g bladder or kidney was determined 3 days postinoculation for the independent challenges and at 6, 16, 48, 60, and 72 h postinoculation for the cochallenges. While these mutants colonized the urinary tract during independent challenge, each of the mutants was outcompeted by the wild-type strain to various degrees at specific time points during cochallenge. Altogether, these results suggest that flagella and flagellum-mediated motility/chemotaxis may not be absolutely required for virulence but that these traits contribute to the fitness of UPEC and therefore significantly enhance the pathogenesis of UTIs caused by UPEC.
Uropathogenic
Escherichia coli
Flagella Aid in Efficient Urinary Tract Colonization
Authors: Wright Kelly J. , Seed Patrick C. , Hultgren Scott J.
Published: October 2005

In the murine model of urinary tract infections (UTI), cystitis by uropathogenic
Escherichia coli
(UPEC) occurs through an intimate relationship with the bladder superficial umbrella cell entailing cycles of adherence, invasion, intracellular bacterial community (IBC) formation, and dispersal (fluxing) from the intracellular environment. IBC dispersal is a key step that results in the spread of bacteria over the epithelial surface to initiate additional rounds of IBC formation. We investigated the role of flagella in mediating adherence and motility during UTI, hypothesizing that the dispersion of the IBC would be incomplete in the absence of motility, thus interrupting the IBC pathway and attenuating the infection. Using
gfp
reporter fusions, the expression of the flagellar class I
flhDC
and class III
fliC
genes was monitored to track key points of regulation throughout the pathogenic cascade. In vitro, growth under conditions promoting motility resulted in the robust expression of both fusions. In contrast, only the class I fusion produced significant expression throughout early stages of IBC development including the dispersion stage. Thus, unlike in vitro modeling of motility, the regulatory cascade appeared incomplete in vivo. Throughout IBC formation, nonmotile Δ
fliC
mutants achieved the same number of IBCs as the wild-type (
wt
) strain, demonstrating that flagella are neither essential nor required for first- or second-generation IBC formation. However, in competition experiments between
wt
and Δ
fliC
strains, the
wt
was shown to have a fitness advantage in persisting throughout the urinary tract for 2 weeks, demonstrating a subtle but measurable role for flagella in virulence.
Cardiac Apoptosis in Severe Relapsing Fever Borreliosis
Authors: Londoño Diana , Bai Yunhong , Zückert Wolfram R. , Gelderblom Harald , Cadavid Diego
Published: October 2005

Previous studies revealed that the heart suffers significant injury during experimental Lyme and relapsing fever borreliosis when the immune response is impaired (D. Cadavid, Y. Bai, E. Hodzic, K. Narayan, S. W. Barthold, and A. R. Pachner, Lab. Investig.84:1439-1450, 2004; D. Cadavid, T. O'Neill, H. Schaefer, and A. R. Pachner, Lab. Investig.80:1043-1054, 2000; and D. Cadavid, D. D. Thomas, R. Crawley, and A. G. Barbour, J. Exp. Med. 179:631-642, 1994). To investigate cardiac injury in borrelia carditis, we used antibody-deficient mice persistently infected with isogenic serotypes of the relapsing fever agentBorrelia turicatae. We studied infection in hearts 1 to 2 months after inoculation by TaqMan reverse transcription-PCR and immunohistochemistry (IHC) and inflammation by hematoxylin and eosin and trichrome staining, IHC, and in situ hybridization (ISH). We studied apoptosis by terminal transferase-mediated DNA nick end labeling assay and measured expression of apoptotic molecules by RNase protection assay, immunofluorescence, and immunoblot. All antibody-deficient mice, but none of the immunocompetent controls, developed persistent infection of the heart. Antibody-deficient mice infected with serotype 2 had more severe cardiac infection and injury than serotype 1-infected mice. The injury was more severe around the base of the heart and pericardium, corresponding to sites of marked infiltration by activated macrophages and upregulation of interleukin-6 (IL-6). Infected hearts showed evidence of apoptosis of macrophages and cardiomyocytes as well as significant upregulation of caspases, most notably caspase-1. We conclude that persistent infection with relapsing fever borrelias causes significant loss of cardiomyocytes associated with prominent infiltration by activated macrophages, upregulation of IL-6, induction of caspase-1, and apoptosis.
Exposure to Mycobacteria Primes the Immune System for Evolutionarily Diverse Heat Shock Proteins
Authors: Qazi Khaleda Rahman , Qazi Mousumi Rahman , Julián Esther , Singh Mahavir , Abedi-Valugerdi Manuchehr , Fernández Carmen
Published: October 2005

During stress conditions, such as infection, the synthesis of heat shock proteins (HSPs) in microorganisms is upregulated. Since a high degree of homology exists within each HSP family, we postulated that exposure to microorganisms could prime the immune system for evolutionarily diverse HSPs. We tested this hypothesis by priming mice with three microorganisms, namely,Mycobacterium bovisBCG,Mycobacterium vaccae, andChlamydia pneumoniae.After this, mice received a dose of the various HSPs. We found that BCG andM. vaccaebut notC. pneumoniaeprimed the immune system for the induction of secondary immunoglobulin G (IgG) responses to most of the HSPs tested. Analysis of the IgG1 and IgG2a profile and gamma interferon production induced against the HSPs revealed the induction of a mixture of responses. We also observed that sera from mice treated withM. vaccaeand HSP70 were cross-reactive, but no antibody complexes were observed in their kidneys, which frequently are targets for autoantibody reactions. Our findings add further support for the use of HSPs as effective vaccine adjuvants.
Intranasal Immunization Strategy To Impede Pilin-Mediated Binding ofPseudomonas aeruginosato Airway Epithelial Cells
Authors: Hsieh Jennifer C. , Tham Doris M. , Feng Weijun , Huang Fan , Embaie Selamawit , Liu Keyi , Dean Deborah , Hertle Ralf , FitzGerald David J. , Mrsny Randall J.
Published: October 2005

Prevention of pulmonaryPseudomonas aeruginosainfections represents a critical unmet medical need for cystic fibrosis (CF) patients. We have examined the tenet that a mucosal immunization approach can reduce interactions of a piliated form of this opportunistic pathogen with respiratory epithelial cells. Vaccinations were performed using ntPEpilinPAK, a protein chimera composed of a nontoxic form ofP. aeruginosaexotoxin A (ntPE), where the C-terminal loop amino acid sequence of the PAK strain pilin protein was inserted in place of the ntPE Ib domain. Intranasal (i.n.) immunization of BALB/c mice with ntPEpilinPAK generated both serum and saliva immune responses. A series of in vitro studies showed that diluted samples of saliva obtained from immunized mice reduced pilin-dependentP. aeruginosabinding to polarized human tracheal epithelial cells, protected human pulmonary epithelial cells from cytotoxic actions associated with bacterial challenge, and reduced exotoxin A toxicity. Overall, i.n. administration of ntPEpilinPAK induced mucosal and systemic immune responses that may be beneficial for blocking early stage adhesion and/or infection events of epithelial cell-P. aeruginosainteractions at oropharyngeal surfaces.
Vaccination with a Sindbis Virus-Based DNA Vaccine Expressing Antigen 85B Induces Protective Immunity against
Mycobacterium tuberculosis
Authors: Derrick Steven C. , Yang Amy Li , Morris Sheldon L.
Published: October 2005

To improve DNA vaccination against
Mycobacterium tuberculosis
, we evaluated the effectiveness of a Sindbis virus-based DNA construct expressing the tuberculosis antigen 85B (Sin85B). The protective efficacy of Sin85B was initially assessed by aerogenically challenging immunized C57BL/6 mice with virulent
Mycobacterium tuberculosis
. At 1 and 7 months postinfection, the lung bacterial burdens were considerably reduced and the lung pathology was improved in vaccinated mice compared to naive controls. Furthermore, the mean survival period for Sin85B-immunized mice (305 ± 9 days) after the tuberculous challenge was extended 102 days relative to the naive mice (203 ± 13 days) and was essentially equivalent to the survival time of
Mycobacterium bovis
BCG-vaccinated mice (294 ± 15 days). The essential role of gamma interferon (IFN-γ) in Sin85B-mediated protection was established by showing that significantly increased levels of IFN-γ mRNA were present postinfection in lung cells from vaccinated mice relative to control mice and by demonstrating that IFN-γ depletion prior to challenge abolished the vaccine-induced protection. The substantial antituberculosis protective responses induced by Sin85B immunization of CD4
−/−
mice strongly suggested that CD8 cells partially mediate Sin85B-induced protective immunity. Interestingly, Sin85B vaccination did not protect RNase L
−/−
(a key enzyme in the innate antiviral response) mice while significant protection was detected in RNase L
−/−
mice immunized with either BCG or a conventional DNA plasmid expressing antigen 85B. These data show that immunization with Sin85B offers protection similar to BCG in a murine model of pulmonary tuberculosis and suggest that Sin85B-induced protection is dependent upon both innate and acquired immune mechanisms.
Whole-Body Imaging of Sequestration of
Plasmodium falciparum
in the Rat
Authors: Pettersson Fredrik , Vogt Anna M. , Jonsson Cathrine , Mok Bobo W. , Shamaei-Tousi Alireza , Bergström Sven , Chen Qijun , Wahlgren Mats
Published: October 2005

The occlusion of vessels by packed
Plasmodium falciparum
-infected (iRBC) and uninfected erythrocytes is a characteristic postmortem finding in the microvasculature of patients with severe malaria. Here we have employed immunocompetent Sprague-Dawley rats to establish sequestration in vivo. Human iRBC cultivated in vitro and purified in a single step over a magnet were labeled with
99m
technetium, injected into the tail vein of the rat, and monitored dynamically for adhesion in the microvasculature using whole-body imaging or imaging of the lungs subsequent to surgical removal. iRBC of different lines and clones sequester avidly in vivo while uninfected erythrocytes did not. Histological examination revealed that a multiadhesive parasite adhered in the larger microvasculature, inducing extensive intravascular changes while CD36- and chondroitin sulfate A-specific parasites predominantly sequester in capillaries, inducing no or minor pathology. Removal of the adhesive ligand
Plasmodium falciparum
erythrocyte membrane protein 1 (PfEMP1), preincubation of the iRBC with sera to PfEMP1 or preincubation with soluble PfEMP1-receptors prior to injection significantly reduced the sequestration. The specificity of iRBC binding to the heterologous murine receptors was confirmed in vitro, using primary rat lung endothelial cells and rat lung cryosections. In offering flow dynamics, nonmanipulated endothelial cells, and an intact immune system, we believe this syngeneic animal model to be an important complement to existing in vitro systems for the screening of vaccines and adjunct therapies aiming at the prevention and treatment of severe malaria.
Development of a Ligand-Directed Approach To Study the Pathogenesis of Invasive Aspergillosis
Authors: Lionakis Michail S. , Lahdenranta Johanna , Sun Jessica , Liu Wei , Lewis Russell E. , Albert Nathaniel D. , Pasqualini Renata , Arap Wadih , Kontoyiannis Dimitrios P.
Published: October 2005

Invasive aspergillosis is a leading cause of infectious death in immunosuppressed patients. Here, we adapted a phage display library-based selection to screen and identify binding peptides to the surface ofAspergillus fumigatusconidia and hyphae. We identified a peptide (sequence CGGRLGPFC) that reliably binds to the surface ofAspergillus fumigatushyphae. Binding was notAspergillusstrain specific, as it was also observed in hyphae of otherAspergillusclinical isolates. Furthermore, CGGRLGPFC-displaying phage targetsAspergillus fumigatushyphae on formalin-fixed paraffin-embedded histopathology sections of lung tissue recovered from mice with invasive pulmonary aspergillosis. This approach may yield reagents such as peptidomimetics for novel diagnostic and therapeutic interventions in invasive aspergillosis.
Memory T Lymphocytes Generated byMycobacterium bovisBCG Vaccination Reside within a CD4 CD44loCD62 LigandhiPopulation
Authors: Kipnis Andre , Irwin Scott , Izzo Angelo A. , Basaraba Randall J. , Orme Ian M.
Published: October 2005

In the lungs of mice vaccinated withMycobacterium bovisBCG, there was an accumulation of CD4 cells expressing the activated effector phenotype CD44hiCD62 ligandlo(CD62Llo) which were capable of secreting gamma interferon. Upon cell transfer, however, cells expressing a resting/naïve phenotype (CD44loCD62Lhi) were capable of protecting the recipients from a virulent challenge infection, suggesting the emergence of T-cell memory from within this subset.
Differential Use of the Two High-Oxygen-Affinity Terminal Oxidases of
Brucella suis
for In Vitro and Intramacrophagic Multiplication
Authors: Loisel-Meyer Séverine , de Bagüés Maria Pilar Jiménez , Köhler Stephan , Liautard Jean-Pierre , Jubier-Maurin Véronique
Published: October 2005

Expression of the high-oxygen-affinity cytochrome
cbb3
and cytochrome
bd
ubiquinol oxidases of
Brucella suis
was studied in vitro and in the intramacrophagic niche, which was previously proposed to be oxygen limited. The cytochrome
cbb3
oxidase was exclusively expressed in vitro, whereas the cytochrome
bd
oxidase was preferentially used inside macrophages and contributed to intracellular bacterial replication.
Decreased Virulence of a
gls24
Mutant of
Enterococcus faecalis
OG1RF in an Experimental Endocarditis Model
Authors: Nannini Esteban C. , Teng Fang , Singh Kavindra V. , Murray Barbara E.
Published: October 2005

In
the current study, the
gls24
disruption mutant TX10100,
previously shown to be more sensitive to bile salts and attenuated in a
mouse peritonitis model, showed an approximately fivefold higher 50%
infective dose than wild-type OG1RF in a rat endocarditis model. When
administered as a mixture, TX10100, unlike a downstream
glsB
mutant, was significantly outnumbered by OG1RF in vegetations, organs,
and blood, despite being inoculated in greater numbers. These results
indicate that
gls24
is important in the pathogenesis of
enterococcal
endocarditis.
Immunization with Recombinant
Streptococcus pneumoniae
Neuraminidase NanA Protects Chinchillas against Nasopharyngeal Colonization
Authors: Tong H. H. , Li D. , Chen S. , Long J. P. , DeMaria T. F.
Published: October 2005

Immunization with recombinant
S. pneumoniae
neuraminidase NanA (rNanA) resulted in a significant reduction in pneumococcal colonization in the chinchilla model. The bacteria were eliminated from the nasopharynx 1 week earlier than that from the control cohort. Our data suggest that rNanA affords protection against pneumococcal nasopharyngeal colonization.
The IncP Island in the Genome of
Brucella suis
1330 Was Acquired by Site-Specific Integration
Authors: Lavigne Jean-Philippe , Vergunst Annette C. , Bourg Gisèle , O'Callaghan David
Published: October 2005

An 18,228-bp region containing open reading frames predicted to be derived from the IncP plasmid or phage ancestors is present in the genomes of
Brucella suis
biovars 1 to 4,
B. canis
,
B. neotomae
, and strains isolated from marine mammals, but not in
B. melitensis
,
B. abortus
,
B. ovis
, and
B. suis
biovar 5. The presence of circular excision intermediates and the results of an analysis of sequenced bacterial genomes suggest that the region downstream of the
guaA
gene is a hotspot for site-specific integration of foreign DNA mediated by a CP4-like integrase.
In Vivo Expression Analysis of the P97 and P102 Paralog Families of
Mycoplasma hyopneumoniae
Authors: Adams Cary , Pitzer Joshua , Minion F. Chris
Published: October 2005

The P97 adhesin and P102 genes of
Mycoplasma hyopneumoniae
each have six paralogs in the genome. We tested whether these genes were expressed during infection. P102 is associated with the mycoplasma and with swine cilia. Further, most of the paralogs were transcribed in vivo in two gene transcriptional units.
Thrower’s fracture of the humerus with radial nerve palsy: an unfamiliar softball injury
Authors: Curtin P , Taylor C , Rice J
Published: October 2005

A fracture of the normal humerus in a healthy young adult most commonly results from significant direct trauma. Throwing sports have become increasingly popular outside of North America and bring with them a novel injury mechanism for clinicians. A 21 year old woman sustained a "thrower’s fracture" of the distal humerus and radial nerve palsy while throwing a softball. She was treated by internal fixation. Her fracture united, and radial nerve neurapraxia resolved after 8 weeks. Clinicians should be aware of this entity so that prodromal symptoms can be recognised early and thrower’s fractures are not investigated unnecessarily.
Rugby World Cup 2003 injury surveillance project
Authors: Best J P , McIntosh A S , Savage T N
Published: October 2005

Objectives:To study match injury patterns and incidence during the Rugby World Cup 2003 (RWC 2003); to compare these patterns and rates with comparative rugby injury data; and to assess differences between teams playing at different levels (eight finalistsv12 non-finalists).

Methods:Data were collected prospectively during the tournament. All injuries were recorded by the 20 participating team physicians. These were submitted to the tournament medical officer. An injury was defined as an event which forced a player either to leave the field or to miss a subsequent game or both.

Results:189 injuries were recorded over 48 matches. This corresponds to 97.9 injuries per 1000 player-hours. Pool matches yielded a higher injury rate than non-pool matches. The 12 non-finalist teams sustained significantly higher injury rates than the eight finalist teams. The player positions open side flanker, inside centre, and number 8 were the most frequently injured positions. There was a low concussion rate, which may reflect under-reporting. The non-finalist teams had a higher rate of recurrent injury.

Conclusions:The injury rate was higher than comparative data. Mismatches in the areas of skill, fitness, and the availability of resources for medical care of players may explain these differences.
Anthropometric and physiological profiles of sepak takraw players
Authors: Jawis M N , Singh R , Singh H J , Yassin M N
Published: October 2005

Objectives:Anthropometric and physiological profiles of national sepak takraw players were determined.

Methods:Thirty nine players, specialising in the three playing positions (tekong/server, feeder, and killer/spiker) were divided into three age categories of under 15 (U15), under 18 (U18), and under 23 (U23) years of age. Height, weight, percent body fat (%bf), maximum oxygen consumption (Vo2max), range of motion (ROM), back and leg strength, and heart rate, for the estimation of oxygen consumption during matches, were recorded. Statistical analysis was performed using one way ANOVA for independent measurements and data are presented as mean±standard deviation.

Results:The U23 players were significantly taller and heavier with significantly better ROM of the neck, trunk, and ankle joints and back and leg strength than the U15 players. No significant difference was found in %bf between the three age categories. Mean maximum heart rate during exercise was significantly higher in the U15 group when compared to the U18 and U23 groups (p<0.05). Mean Vo2maxwas similar between the three groups. Estimated oxygen consumption during matches was 69.1%, 68.5%, and 56.4% of Vo2maxin the killer, tekong, and the feeder groups, respectively.

Conclusions:The mean height, body weight, and cardiopulmonary capacities of the players were within the Malaysian population norms, but were somewhat lower than those of players of other court games from other countries. %bf was also lower in these players. This study provides the much needed anthropometric and physiological data of sepak takraw players for further development of this sport.
Release of α-actin into serum after skeletal muscle damage
Authors: Martínez-Amat A , Boulaiz H , Prados J , Marchal J A , Padial Puche P , Caba O , Rodríguez-Serrano F , Aránega A
Published: October 2005

Objective:The skeletal muscle protein α-actin was investigated in the serum of subjects with severe skeletal muscle damage to assess its utility as a reliable and predictive marker of muscle damage.

Methods:Serum samples were obtained from 33 healthy controls and 33 patients with severe skeletal muscle damage, defined by a total creatine kinase value of >500 IU/l (Rosalki method). Troponin I, troponin T, and myoglobin concentrations were determined by immunoassay and α-actin concentrations by Western blot and densitometry.

Results:The mean serum concentration of α-actin in controls and patients with skeletal muscle damage was 600.9 and 1968.51 ng/ml, respectively, a statistically significant difference. Sera of patients with muscle damage showed higher levels of α-actin than of troponin or myoglobin. No significant difference in troponin I levels was observed between the groups.

Conclusions:According to these results, α-actin was the most significant skeletal muscle damage marker analysed and may be an ideal candidate for the identification of all types of myofibre injury, including sports injuries. Our findings support the use of α-actin as a marker alongside other currently used biological proteins.
Is postural control affected by expertise in alpine skiing?
Authors: Noé F , Paillard T
Published: October 2005

Objectives:This study examined the postural performance of two groups of male skiers competing at different levels and the consequences on postural control of the suppression of visual afferences by eye closure.

Methods:Seven national level (NAT) skiers and 7 regional level (REG) skiers were asked to stand as still as possible on a force platform with eyes opened and closed and while wearing or not wearing their ski boots in a stable posture and in two unstable postures (in the sagittal or frontal plane). Postural performance was assessed with centre of foot pressure measurements.

Results:REG and NAT skiers were similarly influenced by the absence of visual information and presented similar postural performance when tests were performed with ski boots. However, without ski boots, REG skiers displayed better postural performance than NAT skiers.

Conclusions:The inferior postural performance of NAT skiers without ski boots could be a long term effect of repetitive wearing of ski boots, which impairs postural performance by restricting the range of motion of the ankle-foot complex. Since individuals with decreased postural performance are believed to be more susceptible to ankle injury than those with finer postural control, NAT skiers should benefit from specific training aimed at improving postural ability and preventing ankle injury.
Is bowling workload a risk factor for injury to Australian junior cricket fast bowlers?
Authors: Dennis R J , Finch C F , Farhart P J
Published: October 2005

Objectives:To examine whether bowling workload is a risk factor for overuse injury to Australian junior cricket fast bowlers and to evaluate the appropriateness of current bowling workload guidelines.

Methods:Forty four male fast bowlers (mean (standard deviation) age 14.7 (1.4) years) were monitored prospectively over the 2002–2003 season. Bowlers completed a daily diary to record bowling workloads and self reported injuries, which were validated by a physiotherapist. Bowling workload prior to the first injury (for those bowlers who were injured) was compared to workload across the whole season for uninjured bowlers.

Results:Eleven (25%) bowlers reported an overuse-type injury, with seven of these sustaining a back injury. Injured bowlers had been bowling significantly more frequently than uninjured bowlers (median number of days since the previous bowling day: 3.2v3.9 days, Mann-Whitney U = 105.0, p = 0.038). Compared with bowlers with an average of ⩾3.5 rest days between bowling, bowlers with an average of <3.5 rest days were at a significantly increased risk of injury (risk ratio (RR) = 3.1, 95% confidence interval (CI) 1.1 to 8.9). There were also trends towards an increased risk of injury for those who bowled an average of ⩾2.5 days per week (RR = 2.5, 95% CI 0.9 to 7.4) or ⩾50 deliveries per day (RR = 2.0, 95% CI 0.7 to 5.4).

Conclusions:This study has identified high bowling workload as a risk factor for overuse injury to junior fast bowlers. Continued research is required to provide scientific evidence for bowling workload guidelines that are age-specific for junior fast bowlers.
Sit to stand transfer: performance in rising power, transfer time and sway by age and sex in senior athletes
Authors: Feland J B , Hager R , Merrill R M
Published: October 2005

Objective:To observe the differences in performance variables of the sit to stand transfer (as measured on the NeuroCom Balance Master) in a population of senior athletes.

Method:A convenience sample of 173 subjects aged 50 years and older. Data were obtained from voluntary participation in a health fair offered at the annual Huntsman World Senior Games in St George, Utah, USA. All sit to stand tests were performed on the NeuroCom Balance Master. The measured parameters were weight transfer time (WTT), rising power (force exerted to rise), and centre of gravity sway (COG sway) during the rising phase.

Results:A significant difference was found between stratified age groups (50–64 and 65+ years) on rising power. There was also a sex difference in rising power. No significant differences were found in weight transfer time or COG sway.

Conclusion:While rising power decreases with increasing age in senior athletes, WTT and COG sway remain similar regardless of age or sex. The maintenance of these other two variables (WTT and COG sway) may be attributable to physical activity and/or participation in sport.
Changes in performance, skinfold thicknesses, and fat patterning after three years of intense athletic conditioning in high level runners
Authors: Legaz A , Eston R
Published: October 2005

Objectives:To determine if the changes in specific skinfold sites induced by intense athletic conditioning over a three year period were associated with changes in running performance in high level athletes.

Methods:Thirty seven top class runners (eight male and five female sprint trained, 16 male and eight female endurance trained) volunteered to participate in the study. The athletes were divided into class A (n  =  18) and class B (n  =  17), with class A having the best performance. Biceps, triceps, subscapular, pectoral, iliac crest, abdominal, front thigh, and medial calf skinfold thickness and the best running performance were recorded at the beginning and after one, two, and three years of training. A one way analysis of variance and a linear regression analysis were conducted to determine changes and association between performance and skinfold thicknesses. Analyses were controlled for sex, sprint event or endurance event, and class.

Results:Training resulted in a significant increase in performance and decreases in sum of six skinfolds, abdominal, front thigh, and medial calf skinfolds, and the ratio of extremity to trunk skinfolds (E/T, ∑triceps, front thigh, medial calf/∑subscapular, iliac crest, abdominal). There were no significant differences in body weight. Except for the abdominal skinfold, there was no significant difference in trunk skinfolds. Significant differences in these changes were observed by sex for E/T, which decreased and increased in male and female runners respectively, and by class. Class B runners significantly improved performance, with decreased skinfold thicknesses in the lower limb. There were no significant changes in performance or skinfold thicknesses in class A runners. Improvements in performance were consistently associated with a decrease in the lower limb skinfolds.

Conclusions:On the basis of these findings, anthropometric assessment of top class athletes should include an evaluation of all skinfolds. The loss of body fat appears to be specific to the muscular groups used during training. The lower limb skinfolds may be particularly useful predictors of running performance.
Measurement of functional recovery in individuals with acute anterior cruciate ligament rupture
Authors: Button K , van Deursen R , Price P
Published: October 2005

Objectives:To measure functional recovery following acute anterior cruciate ligament (ACL) rupture using a simple and reliable clinical movement analysis system. Clinic based methods that simultaneously quantify different aspects of movement over a range of activities and model functional recovery will help guide rehabilitation.

Methods:A longitudinal study was used to measure gait variables at initial physiotherapy attendance and then at monthly intervals using a digital camcorder and computer for quantitative analysis. Jogging and distance hopping were added during recovery. A sample of 63 ACL deficient subjects entered the study and 48 subjects were measured at least three times. To determine the pattern of recovery, repeated measurements were analysed using a least square fit of the data.

Results:Gait variables took between 95 and 130 days post injury to reach the control mean and stabilise shortly after this. Hopping distance for the injured leg took 62 days to recover to within normal limits and 5 months post injury to reach the control mean. Jogging was already within the control limits at 30 days post injury and demonstrated little change with recovery.

Conclusions:Functional recovery of multiple variables has been modelled. In the early phase of post injury, gait velocity seems to be the most useful variable to measure improvement. Recovery of more challenging activities appears to take an average of 5 months. Therefore, patients may need to be monitored in physiotherapy until this time and advised not to return to sport until sufficient recovery is demonstrated on activities such as distance hopping.
Muscle activity during the golf swing
Authors: McHardy A , Pollard H
Published: October 2005

In the right hands, the golf swing is a motion that inspires looks of awe from the public. It is a complex movement of the whole body to generate power to a golf ball to propel the ball great distances with accuracy. This movement relies on the coordinated sequence of muscle activation to produce a fluid and reproducible movement. This paper reviews the literature on golf swing related muscle activity. The phases of this activity are discussed with a view to assisting the practitioner in understanding the swing. Such understanding may help in the management of the injured golfer.
SYSTEMATIC ANALYSIS OF CRITICAL POINT NUCLEI IN THE RARE-EARTH REGION WITH RELATIVISTIC MEAN FIELD THEORY
Authors: SHENG ZONG-QIANG , GUO JIAN-YOU
Published: October 2005

The shape phase transition between spherical U (5) and axially deformed SU (3) nuclei is investigated systemically for the rare-earth region nuclei by the constrained relativistic mean field theory with the interactions NL3. The properties of ground state for Nd , Gd and Dy isotopes are described fairly well as compared with experiments. By examining the potential energy curve and quadruple deformation β2 obtained with this microscopic approach, the possible critical point nuclei are suggested to be 148,150 Nd for Nd isotopes, but 148 Nd is the best candidate, and 150 Nd is slightly to the rotor side of the phase transition. For Gd and Dy isotopes, 150,152 Gd and 152,154 Dy are suggested to be the critical point nuclei. Similar conclusions are also drawn from the microscopic neutron single particle spectra.
SIMPLE COSMOLOGICAL MODEL WITH RELATIVISTIC GAS
Authors: DE BERREDO-PEIXOTO GUILHERME , SHAPIRO ILYA L. , SOBREIRA FLÁVIA
Published: October 2005

We construct simple and useful approximation for the relativistic gas of massive particles. The equation of state is given by an elementary function and admits analytic solution of the Friedmann equation, including more complex cases when the relativistic gas of massive particles is considered together with radiation or with dominating cosmological constant. The model of relativistic gas may be interesting for the description of primordial Universe, especially as a candidate for the role of a Dark Matter.
LOOP EQUATIONS IN ABELIAN GAUGE THEORIES
Authors: DI BARTOLO CAYETANO , LEAL LORENZO , PEÑA FRANCISCO
Published: October 2005

The equations obeyed by the vacuum expectation value of the Wilson loop of Abelian gauge theories are considered from the point of view of the loop-space. An approximative scheme for studying these loop-equations for lattice Maxwell theory is presented. The approximation leads to a partial difference equation in the area and length variables of the loop, and certain physically motivated ansatz is seen to reproduce the mean field results from a geometrical perspective.
ISOSPIN SYMMETRY BREAKING THROUGH π0–η–η′ MIXING
Authors: KROLL P.
Published: October 2005

Mixing of the pseudoscalar mesons is discussed in the quark-flavor basis. The divergences of the axial vector currents which embody the axial vector anomaly, combined with the assumption that the decay constants follow the pattern of particle state mixing in that basis, determine the mixing parameters for given masses of the physical mesons. These mixing parameters are compared with results from other work in some detail. Phenomenological applications of the quark-flavor mixing scheme are presented with particular interest focussed on isospin symmetry breaking which is generated by means of η and η′ admixtures to the pion. Consequences of a possible difference in the basis decay constants fuand fdfor the strength of isospin symmetry breaking are also examined.
COSMOLOGICAL INFLUENCE OF SUPER-HUBBLE PERTURBATIONS
Authors: KOLB EDWARD W. , MATARRESE SABINO , NOTARI ALESSIO , RIOTTO ANTONIO
Published: October 2005

The existence of cosmological perturbations of wavelength larger than the Hubble radius is a generic prediction of the inflationary paradigm. We provide the derivation beyond perturbation theory of a conserved quantity which generalizes the linear comoving curvature perturbation. As a by-product, we show that super-Hubble-radius (super-Hubble) perturbations have no physical influence on local observables (e.g. the local expansion rate) if cosmological perturbations are of the adiabatic type.
A SPECULATIVE RELATION BETWEEN THE COSMOLOGICAL CONSTANT AND THE PLANCK MASS
Authors: HSU S. , ZEE A.
Published: October 2005

We propose the relation MΛ ~ (M P MU)½ where MΛ, M P and MU denote the mass scale associated with the cosmological constant, the gravitational interaction, and the size of the universe respectively. The meaning of the phrase "the size of the universe" is discussed in the text.
COMPUTATIONS ON B-MODEL GEOMETRIC TRANSITIONS
Authors: FORBES BRIAN
Published: October 2005

We study geometric transitions on Calabi–Yau manifolds from the perspective of the B model at genus g=0, with h=1 holes. We first perform a trivial check of the physically predicted duality across the conifold transition. Afterwards, a more complicated case is worked out directly at the level of period integrals, without resorting to periods of the imbedded Riemann surface.
DELAY, PARAMETRIC EXCITATION, AND THE NONLINEAR DYNAMICS OF CUTTING PROCESSES
Authors: STÉPÁN GÁBOR , INSPERGER TAMÁS , SZALAI RÓBERT
Published: October 2005

It is a rule of thumb that time delay tends to destabilize any dynamical system. This is not true, however, in the case of delayed oscillators, which serve as mechanical models for several surprising physical phenomena. Parametric excitation of oscillatory systems also exhibits stability properties sometimes defying our physical sense. The combination of the two effects leads to challenging tasks when nonlinear dynamic behaviors in these systems are to be predicted or explained as well. This paper gives a brief historical review of the development of stability analysis in these systems, induced by newer and newer models in several fields of engineering. Local and global nonlinear behavior is also discussed in the case of the most typical parametrically excited delayed oscillator, a recent model of cutting applied to the study of high-speed milling processes.
BIFURCATION AND CHAOTIC MOTION OF AN ELASTIC PLATE OF LARGE DEFLECTION UNDER PARAMETRIC EXCITATION
Authors: HAN Q. , DAI L. , DONG M.
Published: October 2005

The dynamic behavior of a nonlinear elastic rectangular plate of large deflection subjected to harmonic excitation is investigated. Using the Galerkin principle, a double mode model is established for the plate. The stability and bifurcation behavior of the plate is studied in detail for various loading conditions and system parameters. A set of autonomous equations is derived with the method of averaging. The bifurcation behavior is examined on the basis of the autonomous equations, and the results of theoretical bifurcation analysis are numerically verified. The chaotic response of the plate to the external excitation is also investigated. The governing equations of single as well as double modes are established and the comparison between the single and double mode models is carried out. The applicable conditions of the single mode method are provided. The results obtained show that the single mode approach usually used may lead to incorrect conclusions under certain conditions.
NINETY PLUS THIRTY YEARS OF NONLINEAR DYNAMICS: LESS IS MORE AND MORE IS DIFFERENT
Authors: HOLMES PHILIP
Published: October 2005

I review the early (1885–1975) and more recent history of dynamical systems theory, identifying key principles and themes, including those of dimension reduction, normal form transformation and unfolding of degenerate cases. I end by briefly noting recent extensions and applications in nonlinear fluid and solid mechanics, with a nod toward mathematical biology. I argue throughout that this essentially mathematical theory was largely motivated by nonlinear scientific problems, and that after a long gestation it is propagating throughout the sciences and technology.
RECURRENCE OF ORDER IN CHAOS
Authors: CONTOPOULOS G. , HARSOULA M. , DVORAK R. , FREISTETTER F.
Published: October 2005

The standard map x′ = x + y′, y′ = y + (K/2π) sin (2πx), where both x and y are given modulo 1, becomes mostly chaotic for K ≥ 8, but important islands of stability appear in a recurrent way for values of K near K = 2nπ (groups of islands I and II), and K = (2n + 1)π (group III), where n ≥ 1. The maximum areas of the islands and the intervals ΔK, where the islands appear, follow power laws. The changes of the areas of the islands around a maximum follow universal patterns. All islands surround stable periodic orbits. Most of the orbits are irregular, i.e. unrelated to the orbits of the unperturbed problem K = 0. The main periodic orbits of periods 1, 2 and 4 and their stability are derived analytically. As K increases these orbits become unstable and they are followed by infinite period-doubling bifurcations with a bifurcation ratio δ = 8.72. We find theoretically the connections between the various families and the extent of their stability. Numerical calculations verify the theoretical results.
SLOW HIGH-FREQUENCY EFFECTS IN MECHANICS: PROBLEMS, SOLUTIONS, POTENTIALS
Authors: THOMSEN JON JUEL
Published: October 2005

Strong high-frequency excitation (HFE) may change the "slow" (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening — an apparent change in the stiffness associated with an equilibrium; Biasing — a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening — a tendency for discontinuities to be apparently smeared out by HFE. The effects and a method for analyzing them are introduced, first in terms of simple physical examples, and then in generalized form for mathematical models covering broad classes of discrete and continuous mechanical systems. Several application examples are summarized. Three mathematical tools for analyzing HFE effects are described and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes with a suggestion that more vibration experts, researchers and students should be aware of HFE effects, for the benefit of general vibration troubleshooting, and also for furthering the creation of innovative technical devices and processes utilizing HFE effects.
WAVE ATTRACTORS: LINEAR YET NONLINEAR
Authors: MAAS LEO R. M.
Published: October 2005

A number of physical mechanisms give rise to confined linear wave systems whose spatial structure is governed by a hyperbolic equation. These lack the discrete set of regular eigenmodes that are found in classical wave systems governed by an elliptic equation. In most 2D hyperbolic cases the discrete eigenmodes are replaced by a continuous spectrum of wave fields that possess a self-similar spatial structure and have a (point, line or planar) singularity in the interior. These singularities are called wave attractors because they form the attracting limit set of an iterated nonlinear map, which is employed in constructing exact solutions of this hyperbolic equation. While this is an inviscid, ideal fluid result, observations support the physical relevance of wave attractors by showing localization of wave energy onto their predicted locations. It is shown that in 3D, wave attractors may co-exist with a regular kind of trapped wave. Wave attractors are argued to be of potential relevance to fluids that are density-stratified, rotating, or subject to a magnetic field (or a combination of these) all of which apply to geophysical media.
GEOMETRY OF VIBRATIONAL STABILIZATION AND SOME APPLICATIONS
Authors: LEVI MARK
Published: October 2005

This paper gives a short overview of various applications of stabilization by vibration, along with the exposition of the geometrical mechanism of this phenomenon. More specifically, the following observation is described: a rapidly vibrated holonomic system can be approximated by a certain associated nonholonomic system. It turns out that effective forces in some rapidly vibrated (holonomic) systems are the constraint forces of an associated auxiliary nonholonomic constraint. In particular, we review a simple but remarkable connection between the curvature of the pursuit curve (the tractrix) on the one hand and the effective force on the pendulum with vibrating support. The latter observation is a part of a recently discovered close relationship between two standard classical problems in mechanics: (1) the pendulum whose suspension point executes fast periodic motion along a given curve, and (2) the Chaplygin skate (known also as the Prytz planimeter, or the "bicycle"). The former is holonomic, the latter is nonholonomic. The holonomy of the skate shows up in the effective motion of the pendulum. This relationship between the pendulum with a twirled pivot and the Chaplygin skate has somewhat unexpected physical manifestations, such as the drift of suspended particles in acoustic waves. Finally, a higher-dimensional example of "geodesic motion" on a vibrating surface is described.
STABILITY AND BIFURCATION ANALYSIS ON A DELAYED NEURAL NETWORK MODEL
Authors: LI XIULING , WEI JUNJIE
Published: October 2005

A simple delayed neural network model with four neurons is considered. Linear stability of the model is investigated by analyzing the associated characteristic equation. It is found that Hopf bifurcation occurs when the sum of four delays varies and passes a sequence of critical values. The stability and direction of the Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. An example is given and numerical simulations are performed to illustrate the obtained results. Meanwhile, the bifurcation set is provided in the appropriate parameter plane.
BIFURCATIONS AND CHAOS IN TIME DELAYED PIECEWISE LINEAR DYNAMICAL SYSTEMS
Authors: SENTHILKUMAR D. V. , LAKSHMANAN M.
Published: October 2005

We reinvestigate the dynamical behavior of a first order scalar nonlinear delay differential equation with piecewise linearity and identify several interesting features in the nature of the associated bifurcations and chaos as a function of delay time and external forcing parameters. In particular, we point out that the fixed point solution exhibits a stability island in the two parameter space of time delay and strength of nonlinearity. The significant role played by transients in attaining steady state solutions is pointed out. Various routes to chaos and existence of hyperchaos even for low values of time delay evidenced by multiple positive Lyapunov exponents are brought out. The study is extended to the case of two coupled systems, one with delay and the other one without delay.