Old adults preserve motor flexibility during rapid reaching

Purpose Our ability to flexibly coordinate the available degrees of freedom allows us to perform activities of daily living under various task constraints. Healthy old adults exhibit subclinical peripheral and central nervous system dysfunctions, possibly compromising the flexibility in inter-joint coordination during voluntary movements and the ability to adapt to varying task constraints. Method We examined how healthy old (75.4 +/- 5.2 years, n = 14) compared with young adults (24.3 +/- 2 years, n = 15) make use of the available motor flexibility to adapt to physical and dexterity constraints during a rapid goal-directed reaching task. We manipulated physical and dexterity demands by changing, respectively, external resistance and target size. Motor flexibility was quantified by an uncontrolled manifold (UCM) analysis. Results We found that healthy young and old adults employ similar motor flexibility as quantified by the ratio between goal equivalent and non-goal equivalent variability (V-Ratio) and were similarly able to adapt to increases in physical and dexterity demands during goal-directed rapid reaching (V-Ratio: p = .092; young: 0.548 +/- 0.113; old: 0.264 +/- 0.117). Age affected end-effector kinematics. Motor flexibility and end-effector kinematics did not correlate. Conclusions The data challenge the prevailing view that old age affects movement capabilities in general and provide specific evidence that healthy old adults preserve motor flexibility during a reaching task. Future studies applying UCM analysis should examine if experimental set-ups limit movement exploration, leaving possible age differences undetected

SImulator of GAlaxy Millimetre/submillimetre Emission (SIGAME): CO emission from massive z=2 main-sequence galaxies

We present SIGAME (SImulator of GAlaxy Millimetre/submillimetre Emission), a new numerical code designed to simulate the 12CO rotational line emission spectrum of galaxies. Using sub-grid physics recipes to post-process the outputs of smoothed particle hydrodynamics (SPH) simulations, a molecular gas phase is condensed out of the hot and partly ionized SPH gas. The gas is subjected to far-UV radiation fields and cosmic ray ionization rates which are set to scale with the local star formation rate volume density. Level populations and radiative transport of the CO lines are solved with the 3-D radiative transfer code LIME. We have applied SIGAME to cosmological SPH simulations of three disc galaxies at z=2 with stellar masses in the range ~(0.5-2)x10^11 Msun and star formation rates ~40-140 Msun/yr. Global CO luminosities and line ratios are in agreement with observations of disc galaxies at z~2 up to and including J=3-2 but falling short of the few existing J=5-4 observations. The central 5 kpc regions of our galaxies have CO 3-2/1-0 and 7-6/1-0 brightness temperature ratios of ~0.55-0.65 and ~0.02-0.08, respectively, while further out in the disc the ratios drop to more quiescent values of ~0.5 and <0.01. Global CO-to-H2 conversion (alpha_CO) factors are ~=1.5 Msun*pc^2/(K km s/1), i.e. ~2-3 times below typically adopted values for disc galaxies, and alpha_CO increases with radius, in agreement with observations of nearby galaxies. Adopting a top-heavy Giant Molecular Cloud (GMC) mass spectrum does not significantly change the results. Steepening the GMC density profile leads to higher global line ratios for J_up>=3 and CO-to-H2 conversion factors [~=3.6 Msun*pc^2/(K km/s)].Comment: 28 pages, 20 figures. Accepted for Publication in MNRAS. Substantial revisions from the previous version, including tests with model galaxies similar to the Milky Way. Improved figures and added table

Microvascular decompression for trigeminal neuralgia in the elderly: efficacy and safety

OBJECTIVE The safety and efficacy of surgical microvascular decompression (MVD) in elderly patients with trigeminal neuralgia (TN) is controversially discussed in the literature. A widespread reluctance to expose this cohort to major intracranial surgery persists. Our aim was to compare the efficacy and safety between older and younger patients with TN. METHODS In this cross-sectional study, 139 MVD procedures (103 patients < 70 and 36 patients ≥ 70) were included. Surgical fitness was assessed by the American Society of Anesthesiology (ASA) grade. The pain-free interval was evaluated using Kaplan-Meier analysis only in patients with a recent follow-up visit. Independent risk factors for recurrence in patients with a minimum 12-month follow-up were determined. RESULTS Patients ≥ 70 showed a significantly higher number of comorbidities. Pain intensity, affection of trigeminal branches and symptom duration was similar between groups. No significant difference in treatment associated complications and permanent neurological deficits was shown. There was no treatment-related mortality. A tendency towards a lower recurrence rate in patients < 70 did not reach statistical significance (17.6% vs. 28.6%, P = 0.274). Pain-free interval was not different between both cohorts (78.7 vs. 73.5 months, P = 0.391). CONCLUSION Despite a higher prevalence of comorbidities in elderly patients, complication rates and neurological deficits after MVD were comparable to younger patients. Rates of immediate and long-term pain relief compared favorably to previous studies and were similar between elderly and younger patients. These data endorse MVD as a safe and effective first-line surgical procedure for elderly patients with TN and neurovascular conflict on MRI

Galoisgruppen von Eisensteinpolynomen über p-adischen Körpern

Christian GrevePaderborn, Univ., Diss., 201

Conservative interventions to improve foot progression angle and clinical measures in orthopedic and neurological patients:A systematic review and meta-analysis

To establish the comparative effects of conservative interventions on modifying foot progression angle (FPA) in children and adults with orthopaedic and neurological disease was the main aim of the literature review. Pubmed, Embase, Cinahl, and Web of Science were systematically searched for studies evaluating the effects of conservative interventions on correcting the FPA. The study protocol was registered with PROSPERO (CRD42020143512). Two reviewers independently assessed studies for inclusion and quality. Studies that assessed conservative interventions that could have affected the FPA and objectively measured the FPA were included. Within group Mean Differences (MD) and Standardized Mean Differences (SMDs) of the interventions were calculated for the change in FPA and gait performance (walking speed, stride/step length) and clinical condition (pain). Intervention effects on FPA were synthesized via meta-analysis or qualitatively. 41 studies were identified. For patients with knee osteoarthritis gait training interventions (MD = 6.69° and MD = 16.06°) were significantly more effective than mechanical interventions (MD = 0.44°) in modifying the FPA towards in-toeing (p < 0.00001). Increasing or decreasing the FPA significantly improved pain in patients with medial knee OA. Results were inconclusive for the effectiveness of gait training and mechanical devices in patients with neurological diseases. Gait feedback training is more effective than external devices to produce lasting improvements in FPA, reduce pain, and maintain gait performance in patients with medial knee OA. However, in neurological patients, the effects of external devices on improvements in FPA depends on the interaction between patient-specific impairments and the technical properties of the external device