The Tensor-Vector-Scalar theory and its cosmology

Over the last few decades, astronomers and cosmologists have accumulated vast amounts of data clearly demonstrating that our current theories of fundamental particles and of gravity are inadequate to explain the observed discrepancy between the dynamics and the distribution of the visible matter in the Universe. The Modified Newtonian Dynamics (MOND) proposal aims at solving the problem by postulating that Newton's second law of motion is modified for accelerations smaller than ~10^{-10}m/s^2. This simple amendment, has had tremendous success in explaining galactic rotation curves. However, being non-relativistic, it cannot make firm predictions for cosmology. A relativistic theory called Tensor-Vector-Scalar (TeVeS) has been proposed by Bekenstein building on earlier work of Sanders which has a MOND limit for non-relativistic systems. In this article I give a short introduction to TeVeS theory and focus on its predictions for cosmology as well as some non-cosmological studies.Comment: 44 pages, topical review for Classical and Quantum Gravit

Granulocyte-Colony Stimulating Factor (G-CSF) in Stroke Patients with Concomitant Vascular Disease—A Randomized Controlled Trial

G-CSF has been shown in animal models of stroke to promote functional and structural regeneration of the central nervous system. It thus might present a therapy to promote recovery in the chronic stage after stroke.Here, we assessed the safety and tolerability of G-CSF in chronic stroke patients with concomitant vascular disease, and explored efficacy data. 41 patients were studied in a double-blind, randomized approach to either receive 10 days of G-CSF (10 µg/kg body weight/day), or placebo. Main inclusion criteria were an ischemic infarct >4 months prior to inclusion, and white matter hyperintensities on MRI. Primary endpoint was number of adverse events. We also explored changes in hand motor function for activities of daily living, motor and verbal learning, and finger tapping speed, over the course of the study.Adverse events (AEs) were more frequent in the G-CSF group, but were generally graded mild or moderate and from the known side-effect spectrum of G-CSF. Leukocyte count rose after day 2 of G-CSF dosing, reached a maximum on day 8 (mean 42/nl), and returned to baseline 1 week after treatment cessation. No significant effect of treatment was detected for the primary efficacy endpoint, the test of hand motor function.These results demonstrate the feasibility, safety and reasonable tolerability of subcutaneous G-CSF in chronic stroke patients. This study thus provides the basis to explore the efficacy of G-CSF in improving chronic stroke-related deficits.ClinicalTrials.gov NCT00298597

Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

Contains fulltext : 110141.pdf (publisher's version ) (Open Access)BACKGROUND: Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy. METHODS: A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics. RESULTS: Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks. CONCLUSIONS: Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed

Health Status at Long-Term Follow-Up in Patients Treated for Extremity Localized Ewing Sarcoma or Osteosarcoma: A Scandinavian Sarcoma Group Study

Background. The purpose of this study was to evaluate late effects and symptom complaints in long-term survivors (>5 years) of Extremity Bone Sarcoma (EBS Survivors). The results were compared with findings in age- and gender-matched individuals from the general Population (NORMs). Patients and Methods. Among 155 EBS Survivors approached, 133 (86%) were included, and 110 of them (83%) attended an outpatient examination. Health status was evaluated by a mailed questionnaire concerning demographic and current health issues, and physical examinations at the outpatient clinic. Age- and gender-adjusted normative controls were drawn from participants of the Health Study of Nord-Trondelag County (HUNT 2). Results. Median age at follow-up was 29 (15-57) years. Median follow-up Was 12 (6-22) years. Of EBS Survivors 42% had >= 1 somatic disease, 33% had ototoxicity and 13% had reduced renal Function. EBS Survivors were more likely to have heart disease (odds ratio [OR], 7.9; 95% confidence interval [95% CI], 2.5-25.3; P=0.001), hypertension (OR, 3.4; 95% Cl, 1.1-10.1; P=0.03) and thyroid disease (OR, 3.0; 95%, Cl, 1.1-8.3; P=0.04) compared to NORMs. EBS Survivors reported more diarrhoea (29% vs. 19%, P=0.02), palpitations (23% vs. 13%, P=0.01) and shortness of breath (11% vs. 5%, P=0.01) than NORMs. Conclusions. EBS Survivors have poorer health status compared to age- and gender-matched controls. Long-term follow-up of these patients is therefore mandatory. Pediatr Blood Cancer 2009;53:84-89. (C) 2009 Wiley-Liss, Inc