Influence of energy cost and physical fitness on the preferred walking speed and gait variability in elderly women

Typically gait speed decreases and gait variability increases in elderly. The aim of this study was to define the influence of energy cost of walking on gait speed and of health-related physical fitness on gait variability. Thirty healthy young and older women were recruited in the study. Energy cost of walking (NetCW) was analyzed with indirect calorimetry while a kinematic analysis was performed with an optoelectronic system to calculate gait variability (GV) during treadmill walking at different speeds. Gait speed was defined as the preferred walking speed (PWS) of the subject and health related physical fitness (HRPF) comprised body fat, strength, flexibility, and cardiorespiratory fitness. In healthy elderly women, the coefficient of variation of step width was found to be a better indicator of GV than stride time, stride length and double support coefficients of variation. GV was not affected by age allowing a high PWS. Furthermore, significant associations, adjusted for age, body mass index and number of falls, were identified neither between NetCW and the PWS, nor between HRPF and GV; only a significant association was found between hand-grip strength and gait stability. Findings highlighted the importance to evaluate hand-grip strength as an indicator of gait efficiency

Measurement of Dielectric Suppression of Bremsstrahlung

In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy photons in a medium is suppressed because of interactions between the produced photon and the electrons in the medium. This suppression occurs because the emission takes place over on a long distance scale, allowing for destructive interference between different instantaneous photon emission amplitudes. We present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data shows that dielectric suppression occurs at the predicted level, reducing the cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e

Anatomical variants of sphenoid sinuses pneumatisation: a CT scan study on a Northern Italian population

Sphenoid bone may be affected by different variants of pneumatisation, which have a relevant importance from a clinical and surgical point of view. The description of such variants in different populations may give useful information. However, few articles describe the variability of sphenoid pneumatised structures and none of them focuses on Northern Italian population. Variants of pneumatisation of sphenoid bone were described in a sample of 300 Northern Italian patients who underwent a CT scan. More than fifty-seven percent of patients showed a form of anatomical variant: the most common form was the pneumatised pterygoid processes (39.6%), followed by dorsum sellae (32.9%) and clinoid processes (20.3%), without statistically significant differences between males and females (p\ua0>\ua00.01). In 26.3% of patients, a combined pneumatisation of these three structures was observed, being the combination pterygoid processes-dorsum sellae the most frequent (11.3%). In 9.3%, all the three sphenoid structures were affected. This article is the first description of the prevalence of different variants of pneumatisation in a Northern Italian population: the occurrence of such forms has to be acknowledged for their possible clinical and surgical consequences

Kinematic evaluation of physical impairments of an elite Paralympic karateka

Karate is a Japanese martial art that counts millions of practitioners worldwide and that is spreading also in Paralympic competitions, requiring accurate categories definition for disabled athletes. The aim of the study is to present kinematic data of an elite Paralympic karateka, in comparison with able-bodied athletes. The authors also aim to promote a better classification within the discipline, based on objective biomechanical evaluations of physical impairments. A male black belt Paralympic karateka (age: 36 y; body weight: 75.5 kg; height: 173 cm) with lower limbs impairments was evaluated. The athlete had been performing high level karate for 20 years before the disability took place. After the post-operative rehabilitation, he attended 3/4 sessions of para- karate training per week. He performed a standardized sequence of movements, involving a sequence of offensive and defensive techniques, (kata) from traditional Shotokan karate. Joints and body Center of Mass (CoM) kinematics were collected with an optoelectronic motion capture system and compared with those obtained in two groups of able-bodied (elite and amateurs) athletes from a previous study1. Knee angular range of motion (RoM) and peak angular velocity were obtained. Coordinates of CoM were estimated, using the Segmental Centroid Method2, along with CoM average velocity and acceleration. To assess differences between Paralympic karateka and able-bodied groups, the one-sample t-test was performed. The sequence performed by the karateka lasted more than in both able-bodied groups. CoM average velocity and acceleration decreased in comparison with elite karateka. Knees range of movement and peak angular velocity were similar to amateur but lower than elite athletes. Results show that the physical impairments negatively affected the function of lower limbs in the Paralympic athlete. Fundamental skills in karate elite performance (dynamic balance control and joint RoM and angular velocity) were reduced

Everolimus and enteric-coated mycophenolate sodium Ab initio after liver transplantation: Midterm results

Background and aim. Everolimus (EVR) use in liver transplantation (OLT) has been prescribed with calcineurin inhibitors (CNIs), steroids, and monoclonal antibodies. The aim of our study was to evaluate the safety, feasibility, and impact on renal function of EVR ab initio, in combination with enteric-coated mycophenolate sodium (EC-MPS) without the use of induction treatment, steroids, or CNIs.Patients and methods. We retrospective analyzed nine consecutive patients who underwent OLT at our institution. The initial dose of EVR (1.5 mg/d) was adjusted to achieve trough levels of 8 to 12 ng/mL. EC-MPS introduced at 1080 mg/d was maintained at the same dose over time.Results. At a mean follow-up of 21.48 (standard deviation [SD] 1.4) months from OLT, 7/9 recipients were alive with stable graft function. The 2-year patient and graft survivals were 77%. One recipient died due to cerebral hemorrhage and one, lung failure. No clinical evidence of an acute rejection episode was observed. Mean estimated glomerular filtration rate value, according to the Modification of Diet in Renal Disease formula increased from 59.5 (SD 9.89) mL/min/1.73 m(2) at OLT to 100.2 (SD 47.5) mL/min/1.73 m(2) (P = .03) after 12 months and 98.71 (SD 33.74) mL/min/1.73 m(2) (P = .03) after 24 months' follow-up.Conclusion. A double immunosuppression therapy with EVR and EC-MPS ab initio seemed to be efficacions and safe, representing a valid alternative to CNIs to prevent renal failure after OLT

Statistical properties of genealogical trees

We analyse the statistical properties of genealogical trees in a neutral model of a closed population with sexual reproduction and non-overlapping generations. By reconstructing the genealogy of an individual from the population evolution, we measure the distribution of ancestors appearing more than once in a given tree. After a transient time, the probability of repetition follows, up to a rescaling, a stationary distribution which we calculate both numerically and analytically. This distribution exhibits a universal shape with a non-trivial power law which can be understood by an exact, though simple, renormalization calculation. Some real data on human genealogy illustrate the problem, which is relevant to the study of the real degree of diversity in closed interbreeding communities.Comment: Accepted for publication in Phys. Rev. Let

Inference of population splits and mixtures from genome-wide allele frequency data

Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In this model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively) to wolves subsequent to domestication, and that East Asian toy breeds (the Shih Tzu and the Pekingese) result from admixture between modern toy breeds and "ancient" Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.comComment: 28 pages, 6 figures in main text. Attached supplement is 22 pages, 15 figures. This is an updated version of the preprint available at http://precedings.nature.com/documents/6956/version/