Motor learning principles during rehabilitation after anterior cruciate ligament injury:Time to create an enriched environment to improve clinical outcome

Athletes who wish to resume high-level activities after an injury to the anterior cruciate ligament (ACL) are often advised to undergo surgical reconstruction. Nevertheless, ACL reconstruction (ACLR) does not equate to normal function of the knee or a reduced risk of subsequent injuries. A rising concern is the high rate of secondary ACL injuries, particularly in young athletes, with up to 40% of those returning to sport in the first year after surgery experiencing a second ACL rupture. Aside from the increased risk of secondary injury, patients after ACLR have an increased risk of developing early-onset osteoarthritis. Unfortunately, current ACLR rehabilitation programs may not be optimally effective in terms of addressing deficits related to the initial injury and the subsequent surgical intervention. Motor learning to (re)acquire motor skills and neuroplastic capacities are not sufficiently incorporated during traditional rehabilitation, attesting to the high reinjury rates. The purpose of this article is to present novel clinically integrated motor learning principles to support neuroplasticity that can improve patient functional performance and reduce the risk of secondary ACL injury. The novel motor learning principles presented in this manuscript may optimize future rehabilitation programs to reduce the risk of secondary ACL injury and early development of osteoarthritis by targeting changes in neural networks.</p

A Bayesian Approach to Risk Management in a World of High-Frequency Data

A Realised Volatility GARCH model using high-frequency data is developed within a Bayesian framework for the purpose of forecasting Value at Risk and Conditional Value at Risk. A Skewed Student-t return distribution is combined with a Student-t distribution in the measurement equation in a GARCH framework. Realised Volatility GARCH models show a marked improvement compared to ordinary GARCH. A Skewed Student-t Realised DCC copula model using Realised Volatility GARCH marginal functions is developed within a Bayesian framework for the purpose of forecasting portfolio tail risk. The use of copulas is implemented so that the marginal distributions can be separated from the dependence structure to produce tail forecasts. This is compared to using traditional GARCH-copula models, and GARCH on an aggregated portfolio. Copula models implementing a Realised Volatility GARCH framework show an improvement over traditional GARCH models. A Bayesian detection of regime changes utilizing high-frequency data is developed, once again for the purpose of forecasting portfolio tail risk. The use of high-frequency data improves the accuracy of regime change detection compared to daily data. Monte Carlo sampling schemes are employed for the estimation of these models

Water in massive star-forming regions: HIFI observations of W3 IRS5

We present Herschel observations of the water molecule in the massive star-forming region W3 IRS5. The o-H17O 110-101, p-H18O 111-000, p-H2O 22 202-111, p-H2O 111-000, o-H2O 221-212, and o-H2O 212-101 lines, covering a frequency range from 552 up to 1669 GHz, have been detected at high spectral resolution with HIFI. The water lines in W3 IRS5 show well-defined high-velocity wings that indicate a clear contribution by outflows. Moreover, the systematically blue-shifted absorption in the H2O lines suggests expansion, presumably driven by the outflow. No infall signatures are detected. The p-H2O 111-000 and o-H2O 212-101 lines show absorption from the cold material (T ~ 10 K) in which the high-mass protostellar envelope is embedded. One-dimensional radiative transfer models are used to estimate water abundances and to further study the kinematics of the region. We show that the emission in the rare isotopologues comes directly from the inner parts of the envelope (T > 100 K) where water ices in the dust mantles evaporate and the gas-phase abundance increases. The resulting jump in the water abundance (with a constant inner abundance of 10^{-4}) is needed to reproduce the o-H17O 110-101 and p-H18O 111-000 spectra in our models. We estimate water abundances of 10^{-8} to 10^{-9} in the outer parts of the envelope (T < 100 K). The possibility of two protostellar objects contributing to the emission is discussed.Comment: Accepted for publication in the A&A HIFI special issu

The Different Structures of the Two Classes of Starless Cores

We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows that the structure and behavior of the cores is significantly different depending on whether the central density is either above or below about 10^5 cm-3. This density is significant as the critical density for gas cooling by gas-dust collisions and also as the critical density for dynamical stability, given the typical properties of the starless cores. The starless cores thus divide into two classes that we refer to as thermally super-critical and thermally sub-critical.This two-class distinction allows an improved interpretation of the different observational data of starless cores within a single model.Comment: ApJ in pres

Triply deuterated ammonia in NGC 1333

The Caltech Submillimeter Observatory has detected triply deuterated ammonia, ND3, through its 10a-00s transition near 310 GHz. Emission is found in the NGC 1333 region, both towards IRAS 4A and a position to the South-East where DCO+ peaks. In both cases, the hyperfine ratio indicates that the emission is optically thin. Column densities of ND3 are 3--6 x 10^11 cm^-2 for T_ex=10 K and twice as high for T_ex=5 K. Using a Monte Carlo radiative transfer code and a model of the structure of the IRAS source with temperature and density gradients, the estimated ND3 abundance is 3.2 x 10^-12 if ND3/H2 is constant throughout the envelope. In the more likely case that ND3/H2D+ is constant, ND3/H2 peaks in the cold outer parts of the source at a value of 1.0 x 10^-11. To reproduce the observed NH3/ND3 abundance ratio of ~1000, grain surface chemistry requires an atomic D/H ratio of ~0.15 in the gas phase, >10 times higher than in recent chemical models. More likely, the deuteration of NH3 occurs by ion-molecule reactions in the gas phase, in which case the data indicate that deuteron transfer reactions are much faster than proton transfers.Comment: 4 pages, 2 figures; to be published in Astronomy & Astrophysics (Letters

Sustained changes in lipid profile and macrophage migration inhibitory factor levels after anti-tumour necrosis factor therapy in rheumatoid arthritis

BACKGROUND: Macrophage migration inhibitory factor (MIF) has recently emerged as an important cytokine possibly linking rheumatoid arthritis (RA) and atherogenesis. Because atherogenesis is accelerated in RA this study was conducted to investigate whether anti-tumour necrosis factor (TNF) therapy could lead to sustained downregulation of systemic MIF levels and improvement in lipid profiles. METHODS: Fifty RA patients with active disease (disease activity score in 28 joints (DAS28) >or=3.2), who started adalimumab therapy at 40 mg every other week, were included. At baseline, weeks 16 and 52 serum levels of MIF and lipids were assessed. In addition, the DAS28 and serum C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were determined. RESULTS: After 16 weeks of adalimumab therapy, both DAS28 and MIF levels were significantly decreased (p<0.001 and p = 0.020, respectively). This was sustained up to week 52 (p<0.001 and p = 0.012, respectively). CRP levels and ESR were significantly reduced after 16 and 52 weeks of adalimumab therapy (p<0.001). High-density lipoprotein cholesterol levels increased at week 16 (p<0.001), but returned to baseline at week 52. Apolipoprotein (apo) A-I levels increased at week 16 (p<0.001) and remained stable (p = 0.005). This resulted in an improved apo B/A-I ratio. CONCLUSIONS: The results underline the sustained downregulation of MIF as a potential new mechanism by which anti-TNF therapy might reduce vascular inflammation, and as such perhaps cardiovascular morbidity in RA patients. This hypothesis is supported by an improved apo B/A-I ratio as well as reduced CRP levels in these patient

Monocyte migration to the synovium in rheumatoid arthritis patients treated with adalimumab

Objectives The mechanism of action of treatment with tumour necrosis factor (TNF) blockers in rheumatoid arthritis (RA) is still not completely understood. The aim of this study was to test if adalimumab treatment could affect the influx of monocytes into the synovium. Methods A novel technique was used to analyse the migration of labelled autologous monocytes before and 14 days after initiation of adalimumab treatment using scintigraphy. CD14 monocytes were isolated from patients with RA, using a positive selection procedure with magnetic-activated cell sorting, and labelled with technetium-99m-hexamethylpropylene-amino-oxime. Scintigraphic scans were made 1, 2 and 3 h after re-infusion. Results As early as 14 days after the start of treatment with adalimumab a significant decrease in disease activity score evaluated in 28 joints was shown. There was no significant decrease in the influx of monocytes into the joint at this time. Conclusions This study indicates that adalimumab treatment does not reduce the influx of monocytes into the synovium early after initiation of treatment. As previous studies showed a rapid decrease in macrophage infiltration after TNF-antibody therapy, which could not be explained by increased cell death, this points to an important role for enhanced efflux of inflammatory cells from the synoviu

Water abundances in high-mass protostellar envelopes: Herschel observations with HIFI

We derive the dense core structure and the water abundance in four massive star-forming regions which may help understand the earliest stages of massive star formation. We present Herschel-HIFI observations of the para-H2O 1_11-0_00 and 2_02-1_11 and the para-H2-18O 1_11-0_00 transitions. The envelope contribution to the line profiles is separated from contributions by outflows and foreground clouds. The envelope contribution is modelled using Monte-Carlo radiative transfer codes for dust and molecular lines (MC3D and RATRAN), with the water abundance and the turbulent velocity width as free parameters. While the outflows are mostly seen in emission in high-J lines, envelopes are seen in absorption in ground-state lines, which are almost saturated. The derived water abundances range from 5E-10 to 4E-8 in the outer envelopes. We detect cold clouds surrounding the protostar envelope, thanks to the very high quality of the Herschel-HIFI data and the unique ability of water to probe them. Several foreground clouds are also detected along the line of sight. The low H2O abundances in massive dense cores are in accordance with the expectation that high densities and low temperatures lead to freeze-out of water on dust grains. The spread in abundance values is not clearly linked to physical properties of the sources.Comment: 8 pages, 5 figures, accepted for publication the 15/07/2010 by Astronomy&Astrophysics as a letter in the Herschel-HIFI special issu