bluuebunny/crossref_metadata_2025 huggingface dataset:
Negotiating the Evolution of the Hr Function: Practical Advice From the Health Care Sector
Authors: Barnett Steve , Patrickson Margaret , Maddern Janny
Published: February 2007

This paper has two aims. First, to consider explanations for the apparent gap between the paradigm of strategic human resource management on the one hand and actual HR practice on the other. Second, to generate practical advice for senior HR specialists who are aspriring to develop a strategic role for their function. the research underpinning these findings was based on case studies in three hospitals in Adelaide and a comparison of the findings with the situation at Leicester General NHS Trust where the first named author of this article was the HR director and a senior board member. the analysis reveals that specific features of each organisation's history, current structure and management, shape powerfully the nature of the HR function. Moreover, the local shaping factors define the degrees of freedom open to the HR function, so much so, that the notion that it can choose its organisational stance is here challenged.
National Ownership and Hr Practices In Uk Greenfield Sites
Authors: Guest David E. , Hoque Kim
Published: February 2007

This article reports research on the influence of country of ownership on HR policy and practice in UK establishments. It is hypothesised that establishments will conform to national stereotypes in the practices they adopt and that establishments owned by firms from the USA, Japan and Germany, will, albeit in different ways, adopt more HR practices and report better outcomes than their UK counterparts. the research is based on the Third Workplace Industrial Relations Survey and on a sample of new establishments, opened in the 1980s. Analysis of the data from the 1990 Workplace Industrial Relations Survey finds no evidence that foreign‐owned firms are more likely to adopt HR practices. the study of new workplaces finds that UK‐owned establishments are as enthusiastic as the foreign‐owned in their adoption of HR policy and practice. There is also evidence to support, at least partially, the stereotypes of the American and Japanese approaches. However German‐owned establishments do not conform to the expected home country pattern. They are the least likely to adopt HR practices and also report poorer HR and employee relations outcomes. the study challenges the assumption that foreign‐owned firms in the UK are more likely to adopt HR practices and indicates that we must be cautious in applying stereotypical national approaches to HRM both among foreign and UK establishments.
Management training in small firms – a case of market failure?
Authors: Storey David J. , Westhead Paul
Published: February 2007

The take‐up of management training is lower in small than in large firms. A case is often made in the UK that this reflects an ignorance on the part of owner‐managers in small firms of the benefits of training. In other words, the argument is often put that the market is subject to failure and so justifies the provision of subsidies. This paper critiques this view. The analysis shows that market forces explain rather better the lower take‐up of management training by small firms. The authors therefore suggest the assumption of ignorance leading to market failure is unreasonable, and hence they question the case for further public‐funded subsidies.
Turnover culture in the hospitality industry
Authors: Iverson Roderick D. , Deery Margaret
Published: February 2007

Although turnover culture is considered to be a major problem in the hospitality industry, there is little to no research examining its influence on an employee's decision to stay or leave. This study attempts to address this deficiency by testing a causal model of employee intent to leave using a sample of 246 employees from six five‐star accommodation hotels in Australia. The results indicated that turnover culture was the most important determinant of intent to leave, followed by the variables of job search behaviour, job opportunity, organisational commitment, union loyalty, job satisfaction, career development, routinisation, promotional opportunity, role conflict, and negative affectivity. Based on these findings various HR strategies are formulated, which have wider implications for the management of turnover in other work settings.
ESTIMATING MONETARY POLICY RULES FOR SOUTH AFRICA
Authors: Knedlik Tobias
Published: February 2007

The paper combines the estimation of the Monetary Conditions Index (MCI) with the theoretic modelling of optimal monetary policy in South Africa. The idea that monetary policy is not only interested in optimal monetary conditions but also in external stability, provides the basis for the analysis. The paper introduces the concept of the MCI and estimates the relative influence of interest rates and exchange rates on the output gap. The estimated weights are 1.9:1. This estimation results is used to specify operating target rules for South African monetary policy.
The binaural performance of a cross-talk cancellation system with matched or mismatched setup and playback acoustics
Authors: Akeroyd Michael A. , Chambers John , Bullock David , Palmer Alan R. , Summerfield A. Quentin , Nelson Philip A. , Gatehouse Stuart
Published: February 2007

Cross-talk cancellation is a method for synthesizing virtual auditory space using loudspeakers. One implementation is the “Optimal Source Distribution” technique [T. Takeuchi and P. Nelson, J. Acoust. Soc. Am. 112, 2786–2797 (2002)], in which the audio bandwidth is split across three pairs of loudspeakers, placed at azimuths of ±90°, ±15°, and ±3°, conveying low, mid, and high frequencies, respectively. A computational simulation of this system was developed and verified against measurements made on an acoustic system using a manikin. Both the acoustic system and the simulation gave a wideband average cancellation of almost 25dB. The simulation showed that when there was a mismatch between the head-related transfer functions used to set up the system and those of the final listener, the cancellation was reduced to an average of 13dB. Moreover, in this case the binaural interaural time differences and interaural level differences delivered by the simulation of the optimal source distribution (OSD) system often differed from the target values. It is concluded that only when the OSD system is set up with “matched” head-related transfer functions can it deliver accurate binaural cues.
Method for detecting small changes in vibrotactile perception threshold related to tactile acuity
Authors: Brammer A. J. , Piercy J. E. , Pyykkö I. , Toppila E. , Starck J.
Published: February 2007

Two metrics, expressing the change in mechanoreceptor-specific vibrotactile thresholds at a fingertip over a time interval of months or years, and the shift in threshold from the mean values recorded from the fingertips of healthy persons, have been constructed for thresholds measured from individual fingers. The metrics assume the applicability of the acute adaptation property of mechanoreceptors, which has been confirmed by thresholds obtained from 18 forest workers on two occasions, separated by 5 years. Hence, when expressed in decibels, both threshold changes and threshold shifts may be averaged at frequencies mediated by the same receptor population to improve precision. Differences between threshold changes at frequencies mediated by the same receptor population may be used to identify inconsistent subject performance, and hence potentially erroneous results. For this group of subjects, the threshold changes and threshold shifts at frequencies believed mediated by the slowly adapting type I (SAI) (4 and 6.3Hz) and rapidly adapting type I (FAI) (20 and 32Hz) receptors within each finger were correlated. In these circumstances, which may be expected to occur for some work-induced and systemic peripheral neuropathies, both threshold changes and threshold shifts may be summed over SAI and FAI receptors to improve precision, and hence the potential for interpretation.
Basilar membrane tension calculations for the gerbil cochlea
Authors: Naidu Ram C. , Mountain David C.
Published: February 2007

Anatomical studies suggest that the basilar membrane (BM) supports a radial tension, which is potentially important in cochlear mechanics. Assuming that the tension exists, we have calculated its magnitude from measurements of BM stiffness, longitudinal coupling, and geometry using a BM model. Results for the gerbil cochlea show that the tension decreases from the base to the apex of the cochlea and generates a tensile stress that is comparable in magnitude to the stress generated in other physiological systems. The model calculations are augmented by experiments that investigate the source of BM tension. The experimental results suggest that BM tension is maintained by the spiral ligament.
Manipulation of micrometer sized particles within a micromachined fluidic device to form two-dimensional patterns using ultrasound
Authors: Oberti Stefano , Neild Adrian , Dual Jürg
Published: February 2007

Ultrasonic manipulation, which uses acoustic radiation forces, is a contactless manipulation technique. It allows the simultaneous handling of single or numerous particles (e.g., copolymer beads, biological cells) suspended in a fluid, without the need for prior localization. Here it is reported on a method for two-dimensional arraying based on the superposition of two in-plane orthogonally oriented standing pressure waves. A device has been built and the experimental results have been compared with a qualitative analytical model. A single piezoelectric transducer is used to excite the structure to vibration, which consists of a square chamber etched in silicon sealed with a glass plate. A set of orthogonally aligned electrodes have been defined on one surface of the piezoelectric. This allows either a quasi-one-dimensional standing pressure field to be excited in one of two directions or if both electrodes are activated simultaneously a two-dimensional pressure field to be generated. Two different operational modes are presented: two signals identical in amplitude and frequency were used to trap particles in oval shaped clumps; two signals with slightly different frequencies to trap particles in circular clumps. The transition between the two operational modes is also investigated.
A study of vibroacoustic coupling between a pump and attached water-filled pipes
Authors: Li Bilong , Hodkiewicz Melinda , Pan Jie
Published: February 2007

This paper presents a model for the vibroacoustical behavior of a pump coupled with water-filled pipes. Coupling between (a) the pump and the inlet and outlet pipes, and (b) the pipe wall and the fluid contained in the pipe, is investigated through analytical modeling and numerical simulation. In the model, the pump is represented by a rigid body supported by multiple elastic mounts, and the inlet and outlet pipes by two semi-infinite water-filled pipes. The vibration characteristics of the coupled system under the excitation of mechanical forces and fluid-borne forces at the pump are calculated. The results enhance our understanding about how the input mechanical and fluid excitation energy at the pump is transmitted to the pipes and how to relate the piping vibroacoustical response to the excitations at the pump. This study assists in predicting dynamic stress in pipes for given excitations at the pump, and in developing methods to identify the nature (fluid or mechanical) of the excitation forces at the pump using the vibration and dynamic pressure measurements on the pump/pipe system.
Coherent structures of the near field flow in a self-oscillating physical model of the vocal folds
Authors: Neubauer Jürgen , Zhang Zhaoyan , Miraghaie Reza , Berry David A.
Published: February 2007

Current theories of voice production depend critically upon knowledge of the near field flow which emanates from the glottis. While most modern theories predict complex, three-dimensional structures in the near field flow, few investigations have attempted to quantify such structures. Using methods of flow visualization and digital particle image velocimetry, this study measured the near field flow structures immediately downstream of a self-oscillating, physical model of the vocal folds, with a vocal tract attached. A spatio-temporal analysis of the structures was performed using the method of empirical orthogonal eigenfunctions. Some of the observed flow structures included vortex generation, vortex convection, and jet flapping. The utility of such data in the future development of more accurate, low-dimensional models of voice production is discussed.
Drive-point functions and modal density
Authors: Lyon Richard H.
Published: February 2007

It is well known that the real part of a drive-point function, averaged in frequency, can be estimated from the modal density and mass of a structure. Furthermore, the results are often the same as when the modal overlap is large due to damping or when the system boundaries are infinitely extended. The present Note examines the possible use of modal density in estimating the imaginary part of the same system drive-point function.
Acoustoelastic analysis of reflected waves in nearly incompressible, hyper-elastic materials: Forward and inverse problems
Authors: Kobayashi Hirohito , Vanderby Ray
Published: February 2007

Many materials (e.g., rubber or biologic tissues) are “nearly” incompressible and often assumed to be incompressible in their constitutive equations. This assumption hinders realistic analyses of wave motion including acoustoelasticity. In this study, this constraint is relaxed and the reflected waves from nearly incompressible, hyper-elastic materials are examined. Specifically, reflection coefficients are considered from the interface of water and uni-axially prestretched rubber. Both forward and inverse problems are experimentally and analytically studied with the incident wave perpendicular to the interface. In the forward problem, the wave reflection coefficient at the interface is evaluated with strain energy functions for nearly incompressible materials in order to compute applied strain. For the general inverse problem, mathematical relations are derived that identify both uni-axial strains and normalized material constants from reflected wave data. The validity of this method of analysis is demonstrated via an experiment with stretched rubber. Results demonstrate that applied strains and normalized material coefficients can be simultaneously determined from the reflected wave data alone if they are collected at several different (but unknown) levels of strain. This study therefore indicates that acoustoelasticity, with an appropriate constitutive formulation, can determine strain and material properties in hyper-elastic, nearly incompressible materials.
Estimating parameter uncertainties in matched field inversion by a neighborhood approximation algorithm
Authors: Yang Kunde , Ross Chapman N. , Ma Yuanliang
Published: February 2007

In Bayesian inversion, the solution is characterized by its posterior probability density (PPD). A fast Gibbs sampler (FGS) has been developed to estimate the multi-dimensional integrals of the PPD, which requires solving the forward models many times and leads to intensive computation for multi-frequency or range-dependent inversion cases. This paper presents an alternative approach based on a neighborhood approximation Bayes (NAB) algorithm. For lower dimension geoacoustic inversion, the NAB can approximate the PPD very well. For higher dimensional problems and sensitive parameters, however, the NAB algorithm has difficulty estimating the PPD accurately with limited model samples. According to the preliminary PPD estimation from the NAB, this paper developed a multi-step inversion scheme, which adjusts the parameter search intervals flexibly, in order to improve the approximation accuracy of the NAB and obtain more complete parameter uncertainties. The prominent feature of the NAB is to approximate the PPD by incorporating all models for which the forward problem has been solved into the appraisal stage. Comparison of the FGS and NAB for noisy synthetic benchmark test cases and Mediterranean real data indicates that the NAB provides reasonable estimates of the PPD moments while requiring significantly less computation time.
An equivalent roughness model for seabed backscattering at very high frequencies using a band-matrix approach
Authors: Wendelboe Gorm , Jacobsen Finn , Bell Judith M.
Published: February 2007

This work concerns modeling of very high frequency (>100kHz) sonar images obtained from a sandy seabed. The seabed is divided into a discrete number of 1D height profiles. For each height profile the backscattered pressure is computed by an integral equation method for interface scattering between two homogeneous media as formulated by Chan [IEEE Trans. Antennas Propag. 46, 142–149 (1998)]. However, the seabed is inhomogeneous, and volume scattering is a major contributor to backscattering. The SAX99 experiments revealed that the density in the unconsolidated sediment within the first 5mm exhibits a high spatial variation. For that reason, additional roughness is introduced: For each surface point a stochastic realization of the density along the vertical is generated, and the sediment depth at which the density has its maximum value will constitute the new height field value. The matrix of the full integral equation is reduced to a band matrix as the interaction between the point sources on the seabed is neglected from a certain range; this allows computations on long height profiles with lengths up to approximately 25m (at 300kHz). The equivalent roughness approach, combined with the band-matrix approach, agrees with SAX99 data at 300kHz.
Emergence of the acoustic Green’s function from thermal noise
Authors: Godin Oleg A.
Published: February 2007

The fluctuation-dissipation theorem is used to show how acoustic Green’s functions corresponding to sound propagation in opposite directions between any two given points can be extracted from time series of thermal noise recorded at these points. The result applies to arbitrarily inhomogeneous, moving or motionless fluids with time-independent parameters, and demonstrates that the two-point correlation function of thermal noise contains as much information about the environment as can be obtained acoustically by placing transceivers at the two points.
Loudness pattern-based speech quality evaluation using Bayesian modeling and Markov chain Monte Carlo methods
Authors: Chen Guo , Parsa Vijay
Published: February 2007

This work presents a speech quality evaluation method which is based on Moore and Glasberg’s loudness model and Bayesian modeling. In the proposed method, the differences between the loudness patterns of the original and processed speech signals are employed as the observed features for representing speech quality, a Bayesian learning model is exploited as the cognitive model which maps the features into quality scores, and Markov chain Monte Carlo methods are used for the Bayesian computation. The performance of the proposed method was demonstrated through comparisons with the state-of-the-art speech quality evaluation standard, ITU-T P.862, using seven ITU subjective quality databases.
Discrimination of starting phase with sinusoidal envelope modulation
Authors: Sheft Stanley , Yost William A.
Published: February 2007

Modulation-filterbank models discard phase information above very low rates of amplitude modulation (AM). The present work evaluated this restriction by measuring thresholds for discriminating the starting phase of sinusoidal modulators of wideband-noise carriers. Results showed a low-pass characteristic with some listeners unable to perform the task once the modulation rate was greater than 12.5Hz. For others, however, thresholds were obtained with AM rates of up to one to two octaves higher. Intersubject variability may in part relate to the presence of multiple discrimination cues, with only some based on comparison of the ongoing pattern of envelope fluctuation.
Addition of a C-Terminal Cysteine Improves the Anti-Herpes Simplex Virus Activity of a Peptide Containing the Human Immunodeficiency Virus Type 1 TAT Protein Transduction Domain
Authors: Bultmann Hermann , Teuton Jeremy , Brandt Curtis R.
Published: February 2007

Previous studies have shown that peptides containing the protein transduction domain (PTD) of the human immunodeficiency virus tat protein (GRKKRRQRRR) were effective inhibitors of herpes simplex virus type 1 (HSV-1) entry (H. Bultmann and C. R. Brandt, J. Biol. Chem. 277:36018-36023, 2002). We now show that the addition of a single cysteine residue to the C terminus of the TAT PTD (TAT-C peptide) improves the antiviral activity against HSV-1 and HSV-2. The principle effect of adding the cysteine was to enable the peptide to inactivate virions and to induce a state of resistance to infection in cells pretreated with peptide. The TAT-C peptide acted extracellularly, immediately blocked entry of adsorbed virus, prevented VP16 translocation to the nucleus, and blocked syncytium formation and cell-cell spread. Thus, TAT-C peptides are fusion inhibitors. The induction of the resistance of cells to infection was rapid, recovered with a half-life of 5 to 6 h, and could be reinduced by peptide treatment. TAT-C bound to heparan sulfate but was a poor competitor for viral attachment. The antiviral activity depended on the net positive charge of the peptide but not on chirality, and a free sulfhydryl group was not essential for antiviral activity because TAT-C dimers were at least as effective as monomers. The unique combination of antiviral activities and low toxicity combine to make TAT-C a strong candidate for further development as a drug to block HSV infection.
Development and Persistence of Antimicrobial Resistance in
Pseudomonas aeruginosa
: a Longitudinal Observation in Mechanically Ventilated Patients
Authors: Reinhardt Anita , Köhler Thilo , Wood Paul , Rohner Peter , Dumas Jean-Luc , Ricou Bara , van Delden Christian
Published: February 2007

Intubated patients frequently become colonized by
Pseudomonas aeruginosa
, which is subsequently responsible for ventilator-associated pneumonia. This pathogen readily acquires resistance against available antimicrobials. Depending on the resistance mechanism selected for, resistance might either be lost or persist after removal of the selective pressure. We investigated the rapidity of selection, as well as the persistence, of antimicrobial resistance and determined the underlying mechanisms. We selected 109 prospectively collected
P. aeruginosa
tracheal isolates from two patients based on their prolonged intubation and colonization periods, during which they had received carbapenem, fluoroquinolone (FQ), or combined β-lactam-aminoglycoside therapies. We determined antimicrobial resistance phenotypes by susceptibility testing and used quantitative real-time PCR to measure the expression of resistance determinants. Within 10 days after the initiation of therapy, all treatment regimens selected resistant isolates. Resistance to β-lactam and FQ was correlated with
ampC
and
mexC
gene expression levels, respectively, whereas imipenem resistance was attributable to decreased
oprD
expression. Combined β-lactam-aminoglycoside resistance was associated with the appearance of small-colony variants. Imipenem and FQ resistance persisted for prolonged times once the selecting antimicrobial treatment had been discontinued. In contrast, resistance to β-lactams disappeared rapidly after removal of the selective pressure, to reappear promptly upon renewed exposure. Our results suggest that resistant
P. aeruginosa
is selected in less than 10 days independently of the antimicrobial class. Different resistance mechanisms lead to the loss or persistence of resistance after the removal of the selecting agent. Even if resistant isolates are not evident upon culture, they may persist in the lung and can be rapidly reselected.
Neonatal Coinfection Model of Coagulase-Negative Staphylococcus (
Staphylococcus epidermidis
) and
Candida albicans
: Fluconazole Prophylaxis Enhances Survival and Growth
Authors: Venkatesh Mohan Pammi , Pham Don , Fein Mindy , Kong Lingkun , Weisman Leonard E.
Published: February 2007

Coagulase-negative staphylococci (CoNS) and
Candida
are among the most common causes of single infections and coinfections in neonates after 72 h of age. In neonates, coinfection increases the rate of mortality threefold and results in significantly greater morbidity compared to those that result from single infections. In an effort to better understand this phenomenon, we developed the first neonatal animal model of coinfection (with CoNS and
Candida
) and evaluated its effects on mortality and morbidity and the impact of antifungal prophylaxis with fluconazole. Neonatal Wistar rats were infected with
Candida albicans
and/or
Staphylococcus epidermidis
with doses of 2 × 10
8
and 2 × 10
6
CFU subcutaneously in different combinations and were monitored for mortality, weight gain, and bacteremia. The in vitro sensitivity of
C. albicans
to fluconazole was evaluated and the MIC was determined. A subset of rats in these experiments received fluconazole at 10 mg/kg of body weight/dose intraperitoneally starting 24 h before infection for 4 days, and the serum trough levels of fluconazole were measured. Coinfection in the suckling rat significantly increased the rate of mortality compared to that after infection with a single species (
P
< 0.001) and resulted in deaths even at sublethal doses. Coinfection also impaired weight gain significantly in severely infected pups compared to that achieved after infection with a single species (
P
< 0.001). Fluconazole prophylaxis significantly reduced mortality by 30% in the
Candida
group and 36% in the coinfection group and improved weight gain in this neonatal model of coinfection (
P
< 0.001). We developed a neonatal model of coinfection with
Candida
and CoNS, observed significantly greater mortality and morbidity with coinfection, and found that fluconazole prophylaxis significantly reduced the rates of both mortality and morbidity. Further research on neonatal coinfection is urgently needed to improve clinical outcomes.
Comparative Analysis of Amphotericin B Lipid Complex and Liposomal Amphotericin B Kinetics of Lung Accumulation and Fungal Clearance in a Murine Model of Acute Invasive Pulmonary Aspergillosis
Authors: Lewis Russell E. , Liao Guangling , Hou Jinggou , Chamilos Georgios , Prince Randall A. , Kontoyiannis Dimitrios P.
Published: February 2007

The reformulation of amphotericin B (AMB) into a lipid complex (AMB lipid complex [ABLC]) or liposomal carrier (liposomal AMB [L-AMB]) changes the rate and extent of drug distribution to the lung. The importance of pharmacokinetic differences among the various lipid AMB formulations in the treatment of invasive pulmonary aspergillosis (IPA) remains unknown. We compared the kinetics of AMB lung accumulation and fungal clearance of ABLC- and L-AMB-treated mice with acute IPA. BALB/c mice were immunosuppressed with cyclophosphamide and cortisone before intranasal inoculation with 1.5 × 10
6
Aspergillus fumigatus
293 conidia. ABLC or L-AMB was administered in daily intravenous doses (1, 5, or 10 mg/kg of body weight), starting 12 h after infection and continuing until day 5. At predetermined times (0, 24, 72, and 120 h), mice were euthanized, and lungs were harvested for determinations of lung fungal burdens (quantitative PCR) and total AMB lung tissue concentrations. Both ABLC and L-AMB were effective at reducing lung fungal burdens at doses of ≥5 mg/kg/day. Clearance of
A. fumigatus
during the first 24 h was associated with AMB tissue concentrations of >4 μg/g. At 5 mg/kg/day, ABLC produced a more rapid fungal clearance than did L-AMB, but at the end of therapy, fungal burden reductions were similar for both formulations and were not improved with higher dosages. These data suggest that ABLC delivers active AMB to the lung more rapidly than does L-AMB, resulting in faster
Aspergillus
clearance in an experimental model of IPA. However, pharmacodynamic differences between the two formulations were less apparent when mice were dosed at 10 mg/kg/day.
Genetic Elements Carrying
erm
(B) in
Streptococcus pyogenes
and Association with
tet
(M) Tetracycline Resistance Gene
Authors: Brenciani Andrea , Bacciaglia Alessandro , Vecchi Manuela , Vitali Luca A. , Varaldo Pietro E. , Giovanetti Eleonora
Published: February 2007

This study was directed at characterizing the genetic elements carrying the methylase gene
erm
(B), encoding ribosome modification-mediated resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics, in
Streptococcus pyogenes
. In this species,
erm
(B) is responsible for MLS resistance in constitutively resistant isolates (cMLS phenotype) and in a subset (iMLS-A) of inducibly resistant isolates. A total of 125
erm
(B)-positive strains were investigated, 81 iMLS-A (uniformly tetracycline susceptible) and 44 cMLS (29 tetracycline resistant and 15 tetracycline susceptible). Whereas all tetracycline-resistant isolates carried the
tet
(M) gene,
tet
(M) sequences were also detected in most tetracycline-susceptible isolates (81/81 iMLS-A and 7/15 cMLS). In 2 of the 8
tet
(M)-negative cMLS isolates,
erm
(B) was carried by a plasmid-located Tn
917
-like transposon.
erm
(B)- and
tet
(M)-positive isolates were tested by PCR for the presence of genes
int
(integrase),
xis
(excisase), and
tndX
(resolvase), associated with conjugative transposons of the Tn
916
family. In mating experiments using representatives of different combinations of phenotypic and genotypic characteristics as donors,
erm
(B) and
tet
(M) were consistently cotransferred, suggesting their linkage in individual genetic elements. The linkage was confirmed by pulsed-field gel electrophoresis and hybridization studies, and different elements, variably associated with the different phenotypes/genotypes, were detected and characterized by amplification and sequencing experiments. A previously unreported genetic organization, observed in all iMLS-A and some cMLS isolates, featured an
erm
(B)-containing DNA insertion into the
tet
(M) gene of a defective Tn
5397
, a Tn
916
-related transposon. This new element was designated Tn
1116
. Genetic elements not previously described in
S. pyogenes
also included Tn
6002
, an unpublished transposon whose complete sequence is available in GenBank, and Tn
3872
, a composite element resulting from the insertion of the Tn
917
transposon into Tn
916
[associated with a
tet
(M) gene expressed in some cMLS isolates and silent in others]. The high frequency of association between a tetracycline-susceptible phenotype and
tet
(M) genes suggests that transposons of the Tn
916
family, so far typically associated solely with a tetracycline-resistant phenotype, may be more widespread in
S. pyogenes
than currently believed.
Detection of UV-Induced Thymine Dimers in IndividualCryptosporidium parvumandCryptosporidium hominisOocysts by Immunofluorescence Microscopy
Authors: Al-Adhami B. H. , Nichols R. A. B. , Kusel J. R. , O'Grady J. , Smith H. V.
Published: February 2007

To investigate the effect of UV light onCryptosporidium parvumandCryptosporidium hominisoocysts in vitro, we exposed intact oocysts to 4-, 10-, 20-, and 40-mJ·cm−2doses of UV irradiation. Thymine dimers were detected by immunofluorescence microscopy using a monoclonal antibody against cyclobutyl thymine dimers (anti-TDmAb). Dimer-specific fluorescence within sporozoite nuclei was confirmed by colocalization with the nuclear fluorogen 4′,6′-diamidino-2-phenylindole (DAPI). Oocyst walls were visualized using either commercial fluorescein isothiocyanate-labeled anti-Cryptosporidiumoocyst antibodies (FITC-CmAb) or Texas Red-labeled anti-Cryptosporidiumoocyst antibodies (TR-CmAb). The use of FITC-CmAb interfered with TD detection at doses below 40 mJ·cm−2. With the combination of anti-TDmAb, TR-CmAb, and DAPI, dimer-specific fluorescence was detected in sporozoite nuclei within oocysts exposed to 10 to 40 mJ·cm−2of UV light. Similar results were obtained withC. hominis. C. parvumoocysts exposed to 10 to 40 mJ·cm−2of UV light failed to infect neonatal mice, confirming that results of our anti-TD immunofluorescence assay paralleled the outcomes of our neonatal mouse infectivity assay. These results suggest that our immunofluorescence assay is suitable for detecting DNA damage inC. parvumandC. hominisoocysts induced following exposure to UV light.
Prevalence ofStreptococcus suisGenotypes in Wild Boars of Northwestern Germany
Authors: Baums Christoph G. , Verkühlen Gerd Josef , Rehm Thomas , Silva Luciana M. G. , Beyerbach Martin , Pohlmeyer Klaus , Valentin-Weigand Peter
Published: February 2007

Invasive serotype 2 (cps2+) strains ofStreptococcus suiscause meningitis in pigs and humans. Four case reports ofS. suismeningitis in hunters suggest transmission ofS. suisthrough the butchering of wild boars. Therefore, the objective of this study was to investigate the prevalence of potentially human-pathogenicS. suisstrains in wild boars.S. suiswas isolated from 92% of all tested tonsils (n= 200) from wild boars. A total of 244S. suisisolates were genotyped using PCR assays for the detection of serotype-specific genes, the hemolysin genesly, and the virulence-associated genesmrpandepf. The prevalence of thecps2+genotype among strains from wild boars was comparable to that of control strains from domestic pig carriers. Ninety-five percent of thecps2+wild boar strains were positive formrp,sly, andepf*, the large variant ofepf. Interestingly,epf* was significantly more frequently detected incps2+strains from wild boars than in those from domestic pigs;epf* is also typically found in EuropeanS. suisisolates from humans, including a meningitis isolate from a German hunter. These results suggest that at least 10% of wild boars in Northwestern Germany carryS. suisstrains that are potentially virulent in humans. Additional amplified fragment length polymorphism analysis supported this hypothesis, since homogeneous clustering of theepf*mrp+sly+cps2+strains from wild boars with invasive human and porcine strains was observed.
Contributions of Pneumolysin, Pneumococcal Surface Protein A (PspA), and PspC to Pathogenicity ofStreptococcus pneumoniaeD39 in a Mouse Model
Authors: Ogunniyi Abiodun D. , LeMessurier Kim S. , Graham Rikki M. A. , Watt James M. , Briles David E. , Stroeher Uwe H. , Paton James C.
Published: February 2007

Successful colonization of the upper respiratory tract byStreptococcus pneumoniaeis an essential first step in the pathogenesis of pneumococcal disease. However, the bacterial and host factors that provoke the progression from asymptomatic colonization to invasive disease are yet to be fully defined. In this study, we investigated the effects of single and combined mutations in genes encoding pneumolysin (Ply), pneumococcal surface protein A (PspA), and pneumococcal surface protein C (PspC, also known as choline-binding protein A) on the pathogenicity ofStreptococcus pneumoniaeserotype 2 (D39) in mice. Following intranasal challenge with D39, stable colonization of the nasopharynx was maintained over a 7-day period at a level of approximately 105bacteria per mouse. The abilities of the mutant deficient in PspA to colonize the nasopharynx and to cause lung infection and bacteremia were significantly reduced. Likewise, the PspC mutant and, to a lesser extent, the Ply mutant also had reduced abilities to colonize the nasopharynx. As expected, the double mutants colonized less well than the parent to various degrees and had difficulty translocating to the lungs and blood. A significant additive attenuation was observed for the double and triple mutants in pneumonia and systemic disease models. Surprisingly, the colonization profile of the derivative lacking all three proteins was similar to that of the wild type, indicating virulence gene compensation. These findings further demonstrate that the mechanism of pneumococcal pathogenesis is highly complex and multifactorial but ascribes a role for each of these virulence proteins, alone or in combination, in the process.
Effect of Fatty Acids and Cholesterol Present in Bile on Expression of Virulence Factors and Motility of
Vibrio cholerae
Authors: Chatterjee Arpita , Dutta Pradeep K. , Chowdhury Rukhsana
Published: February 2007

Bile induces pleiotropic responses that affect production of virulence factors, motility, and other phenotypes in the enteric pathogen
Vibrio cholerae
. Since bile is a heterogeneous mixture, crude bile was fractionated, and the components that mediate virulence gene repression and enhancement of motility were identified by nuclear magnetic resonance, gas chromatography (GC), and GC-mass spectrometry analyses. The unsaturated fatty acids detected in bile, arachidonic, linoleic, and oleic acids, drastically repressed expression of the
ctxAB
and
tcpA
genes, which encode cholera toxin and the major subunit of the toxin-coregulated pilus, respectively. The unsaturated fatty acid-dependent repression was due to silencing of
ctxAB
and
tcpA
expression by the histone-like nucleoid-structuring protein H-NS, even in the presence of the transcriptional activator ToxT. Unsaturated fatty acids also enhanced motility of
V. cholerae
due to increased expression of
flrA
, the first gene of a regulatory cascade that controls motility. H-NS had no role in the fatty acid-mediated enhancement of motility. It is likely that the ToxR/ToxT system that negatively regulates motility is rendered nonfunctional in the presence of unsaturated fatty acids, leading to an increase in motility. Motility and
flrA
expression were also increased in the presence of cholesterol, another component of bile, in an H-NS- and ToxR/ToxT-independent manner.
Extracellular Gelatinase ofEnterococcus faecalisDestroys a Defense System in Insect Hemolymph and Human Serum
Authors: Park Shin Yong , Kim Kyoung Mi , Lee Joon Ha , Seo Sook Jae , Lee In Hee
Published: February 2007

We isolatedEnterococcus faecalisfrom the body fluids of dead larvae of the greater wax moth,Galleria mellonella. Extracellular gelatinase (GelE) and serine protease (SprE), both of which are considered putative virulence factors ofE. faecalis, were purified from the culture supernatant ofE. faecalis. In an attempt to elucidate their virulence mechanisms, purified GelE and SprE were injected into hemolymph ofG. mellonellaand evaluated with regard to their effects on the immune system of insect hemolymph. As a result, it was determined thatE. faecalisGelE degraded an inducible antimicrobial peptide (Gm cecropin) which is known to perform a critical role in host defense during the early phase of microbial infection. The results obtained from theG. mellonella-E. faecalisinfection model compelled us to assess the virulence activity of GelE against the complement system in human serum.E. faecalisGelE hydrolyzed C3a and also mediated the degradation of the alpha chain of C3b, thereby inhibiting opsonization and the formation of the membrane attack complex resultant from the activation of the complement cascade triggered by C3 activation. In contrast,E. faecalisSprE exhibited no virulence effect against the immune system of insect hemolymph or human serum tested in this study.
Effects of short-term treatment strategies over 4 weeks in Achilles tendinopathy
Authors: Mayer Frank , Hirschmüller Anja , Müller Steffen , Schuberth Martin , Baur Heiner
Published: February 2007

Background:The therapeutic efficacy of non-surgical treatment strategies in Achilles tendinopathy (AT) has not been well clarified. Time-consuming and costly combinations of treatment for pain, physiotherapy and biomechanical procedures are often applied.

Objective:To analyse the efficacy of single therapeutic regimens commonly used over a short period of 4 weeks.

Methods:31 male runners (mileage >32 km/week) with unilateral, untreated AT completed 4 weeks of either physiotherapy (10 treatments: deep-friction, pulsed ultrasound, ice, sensory motor training; (P)), wearing custom fit semirigid insoles (I) or remained without treatment (control group C). Before and after treatment, all patients underwent a treadmill test and a plantar flexion strength exercise. Subjective pain (Pain Disability Index, Pain Experience Scale), as well as strength performance capacity (peak torque), was analysed (mean, 95% CI, repeated measures analysis of variance, α = 0.05).

Results:Pain was reduced to <50% of the baseline value after physiotherapy or after wearing insoles (p<0.05). Individual pain reduction was >50% (25%) in 89% (100%) of subjects in I and 55% (73%) in P. Higher eccentric plantar flexion peak torques after treatment were observed in I and P.

Conclusions:Most patients with AT experience a reduction in pain after only 4 weeks of differentiated, non-surgical treatment consisting of physiotherapy or semirigid insoles.
Changes in muscle temperature induced by 434 MHz microwave hyperthermia
Authors: Ichinoseki-Sekine Noriko , Naito Hisashi , Saga Norio , Ogura Yuji , Shiraishi Minoru , Giombini Arrigo , Giovannini Valentina , Katamoto Shizuo
Published: February 2007

Objective:To investigate the changes in temperature of human muscle during microwave hyperthermia.

Methods:Skin surface and muscle temperatures were measured in 11 healthy adult men (mean (SD) age 24.3 (2.2) years; height 174.2 (6.1) cm; weight 70.0 (5.3) kg) during a 30 min exposure of the thigh to 434 MHz microwave hyperthermia. Skin temperature was maintained at the pilot temperature of 40°C, and the temperature of the water in the bolus was 38°C. The peak power output was set at 60 W and controlled automatically to maintain the pilot temperature. The temperature was measured in the vastus lateralis muscle at an average muscle depth of 2.0 (0.2) cm, using a 23 G Teflon-shielded thermocouple. Biopsy specimens were obtained for light microscopy from three subjects. A muscle-equivalent phantom was used to evaluate the vertical heating pattern.

Results:Both skin and muscle temperatures increased from baseline, and muscle temperature was higher than skin temperature (skin temperature 39.2 (0.5)°C, temperature rise 5.0 (1.5)°C; muscle temperature 43.7 (0.8)°C, temperature rise 8.9 (1.4)°C). At the end of the hyperthermia treatment, muscle temperature decreased to 39.8 (0.9)°C, but was still 4.8 (1.5)°C higher than the baseline. No signs of muscle damage were observed on the basis of the blood creatine kinase activity and histological sections.

Conclusions:The results show that the 434 MHz microwave hyperthermia treatment increased and maintained muscle temperature locally by 6.3–11.4°C without muscle damage. These findings suggest that the microwave hyperthermia system provides effective and safe treatment.
Long-standing groin pain in sportspeople falls into three primary patterns, a “clinical entity” approach: a prospective study of 207 patients
Authors: Hölmich Per
Published: February 2007

Background:Groin pain remains a major challenge in sports medicine.

Aim:To examine 207 consecutive athletes (196 men, 11 women) with groin pain using a standardised and reliable clinical examination programme that focused on signs that suggest pathology in (1) the adductors, (2) the ilopsoas and (3) the rectus abdominis.

Patients and methods:Most patients were football players (66%) and runners (18%). In this cohort, the clinical pattern consistent with adductor-related dysfunction, was the primary clinical entity in 58% of the patients and in 69% of the football players. Iliopsoas-related dysfunction was the primary clinical entity in 36% of the patients. Rectus abdominis-related dysfunction was found in 20 (10%) patients but it was associated with adductor-related pain in 18 of these patients. Multiple clinical entities were found in 69 (33%) patients; of these, 16 patients had three clinical entities.

Conclusions:These descriptive data extend previous findings that physical examination for groin pain can be reliable. While underscoring the prevalence of adductor-related physical examination abnormality in football players, the data highlight the prevalence of examination findings localising to the iliopsoas among this cohort. Also, the fact that combinations of clinical entities were present has important implications for treatment. The finding of multiple abnormal clinical entities also raises the possibility that earlier presentation may be prudent; it is tempting to speculate that one clinical entity likely precedes other developing entities. These data argue for the need for a trial where clinical entities are correlated with systematic investigation including MRI and ultrasonography.
Full symptomatic recovery does not ensure full recovery of muscle-tendon function in patients with Achilles tendinopathy
Authors: Grävare Silbernagel Karin , Thomeé Roland , Eriksson Bengt I , Karlsson Jon
Published: February 2007

Objective:To assess the relationship between muscle-tendon function and symptoms in patients with Achilles tendinopathy using a validated test battery.

Design:A prospective non-randomised trial.

Setting:Orthopaedic Department, Sahlgrenska University Hospital, Sweden.

Patients:37 patients with a clinical diagnosis of Achilles tendinopathy in the midportion of the tendon, with symptoms for >2 months, were evaluated at the initiation of the study and after 1 year.

Intervention:The patients were treated using a rehabilitation programme, under the supervision of a physical therapist, for 6 months.

Main outcome measurements:The patients were evaluated using the Swedish version of the Victorian Institute of Sports Assessment—Achilles questionnaire (VISA-A-S) for symptoms, and a test battery for evaluation of the lower leg muscle-tendon function.

Results:There were significant improvements in the VISA-A-S score (p<0.00, n = 37) and the test battery (p<0.02, n = 19) at the 1-year follow-up. The VISA-A-S questionnaire had an effect size of 2.1 and the test battery had an effect size of 0.73. A low correlation (r = 0.178, p>0.05) was found between the VISA-A-S score and the test battery. A high correlation (r = 0.611, p<0.05) was found between the drop counter movement jump and the VISA-A-S score. All other tests in the test battery had low correlations (r = −0.305 to 0.155, p>0.05) with the VISA-A-S score. Only 25% (4/16) of the patients who had full symptomatic recovery had achieved full recovery of muscle–tendon function as measured by the test battery.

Conclusion:Full symptomatic recovery in patients with Achilles tendinopathy does not ensure full recovery of muscle–tendon function. The VISA-A-S questionnaire and the test battery are sensitive to clinically relevant changes with treatment and can be recommended for use in both the clinic and research.
Ice-water immersion and delayed-onset muscle soreness: a randomised controlled trial
Authors: Sellwood Kylie Louise , Brukner Peter , Williams David , Nicol Alastair , Hinman Rana
Published: February 2007

Objective:To determine if ice-water immersion after eccentric quadriceps exercise minimises the symptoms of delayed-onset muscle soreness (DOMS).

Design:A prospective randomised double-blind controlled trial was undertaken. 40 untrained volunteers performed an eccentric loading protocol with their non-dominant leg.

Interventions:Participants were randomised to three 1-min immersions in either ice water (5±1°C) or tepid water (24°C).

Main outcome measures:Pain and tenderness (visual analogue scale), swelling (thigh circumference), function (one-legged hop for distance), maximal isometric strength and serum creatine kinase (CK) recorded at baseline, 24, 48 and 72 h after exercise. Changes in outcome measures over time were compared to determine the effect of group allocation using independent t tests or Mann–Whitney U tests.

Results:No significant differences were observed between groups with regard to changes in most pain parameters, tenderness, isometric strength, swelling, hop-for-distance or serum CK over time. There was a significant difference in pain on sit-to-stand at 24 h, with the intervention group demonstrating a greater increase in pain than the control group (median change 8.0 vs 2.0 mm, respectively, p = 0.009).

Conclusions:The protocol of ice-water immersion used in this study was ineffectual in minimising markers of DOMS in untrained individuals. This study challenges the wide use of this intervention as a recovery strategy by athletes.