Cerebral activations related to ballistic, stepwise interrupted and gradually modulated movements in parkinson patients

Patients with Parkinson's disease (PD) experience impaired initiation and inhibition of movements such as difficulty to start/stop walking. At single-joint level this is accompanied by reduced inhibition of antagonist muscle activity. While normal basal ganglia (BG) contributions to motor control include selecting appropriate muscles by inhibiting others, it is unclear how PD-related changes in BG function cause impaired movement initiation and inhibition at single-joint level. To further elucidate these changes we studied 4 right-hand movement tasks with fMRI, by dissociating activations related to abrupt movement initiation, inhibition and gradual movement modulation. Initiation and inhibition were inferred from ballistic and stepwise interrupted movement, respectively, while smooth wrist circumduction enabled the assessment of gradually modulated movement. Task-related activations were compared between PD patients (N = 12) and healthy subjects (N = 18). In healthy subjects, movement initiation was characterized by antero-ventral striatum, substantia nigra (SN) and premotor activations while inhibition was dominated by subthalamic nucleus (STN) and pallidal activations, in line with the known role of these areas in simple movement. Gradual movement mainly involved antero-dorsal putamen and pallidum. Compared to healthy subjects, patients showed reduced striatal/SN and increased pallidal activation for initiation, whereas for inhibition STN activation was reduced and striatal-thalamo-cortical activation increased. For gradual movement patients showed reduced pallidal and increased thalamo-cortical activation. We conclude that PD-related changes during movement initiation fit the (rather static) model of alterations in direct and indirect BG pathways. Reduced STN activation and regional cortical increased activation in PD during inhibition and gradual movement modulation are better explained by a dynamic model that also takes into account enhanced responsiveness to external stimuli in this disease and the effects of hyper-fluctuating cortical inputs to the striatum and STN in particular

The deuteron: structure and form factors

A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

K0S and Λ production in Pb-Pb collisions at sNN−−−−√=2.76 TeV

The ALICE measurement of K0S and Λ production at midrapidity in Pb-Pb collisions at sNN−−−√=2.76  TeV is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and in the pT range from 0.4  GeV/c (0.6  GeV/c for Λ) to 12  GeV/c. The pT dependence of the Λ/K0S ratios exhibits maxima in the vicinity of 3  GeV/c, and the positions of the maxima shift towards higher pT with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not observed in pp interactions at s√=0.9  TeV and at s√=7  TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured pT spectra above 2  GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of pT, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the pT dependence of the Λ/K0S ratio

Primary progressive aphasia: a clinical approach

This work was supported by the Alzheimer’s Society (AS-PG-16-007), the National Institute for Health Research University College London Hospitals Biomedical Research Centre and the UCL Leonard Wolfson Experimental Neurology Centre (PR/ylr/18575). Individual authors were supported by the Leonard Wolfson Foundation (Clinical Research Fellowship to CRM), the National Institute for Health Research (NIHR Doctoral Training Fellowship to AV), the National Brain Appeal–Frontotemporal Dementia Research Fund (CNC) and the Medical Research Council (PhD Studentships to CJDH and RLB, MRC Research Training Fellowship to PDF, MRC Clinician Scientist to JDR). MNR and NCF are NIHR Senior Investigators. SJC is supported by Grants from ESRC-NIHR (ES/L001810/1), EPSRC (EP/M006093/1) and Wellcome Trust (200783). JDW was supported by a Wellcome Trust Senior Research Fellowship in Clinical Science (091673/Z/10/Z)

Flight Results from the GeneSat-1 Biological Microsatellite Mission

The mission of the GeneSat-1 technology demonstration spacecraft is to validate the use of research-quality instrumentation for in situ biological research and processing. To execute this mission, the GeneSat-1 satellite was launched on December 16, 2006 from Wallops Flight Facility as a secondary payload off of a Minotaur launch vehicle. During the first week of operation, the core biological growth test was successfully executed, and by the end of the first month of operation all primary science and engineering test objectives had been successfully performed. In its current phase of operation, a variety of secondary technology characterizations tests are being performed, and a wide range of educational, training, and public outreach programs are being supported. This paper reviews the GeneSat-1 mission system, discusses the government-industry-university teaming approach, and presents flight results pertaining to the primary scientific and engineering experiments

Extended Life Flight Results from the GeneSat-1 Biological Microsatellite Mission

The Genesat-1 technology demonstration mission validated the use of research quality instrumentation for in situ biological research and processing. After its launch from Wallops Flight Facility as a secondary payload off a Minotaur launch vehicle on December 16, 2006, all primary science and engineering test objectives were completed successfully within one month of operation. Since that time, additional trend analyses and experiments have been performed to further quantify the performance of the bus; such quantification is of particular interest for at least five heritage-based missions currently in development, three of which are set to launch in 2008 and two slated for 2009. This paper revisits the GeneSat-1 mission system and presents results from the extended mission

O/OREOS Nanosatellite: A Multi-Payload Technology Demonstration

The Organism/Organic Exposure to Orbital Stresses (O/OREOS) nanosatellite follows in the footsteps of the successful GeneSat-1 and PharmaSat missions to validate key technologies developed to conduct compelling science experiments in space for a small price tag. Developed by the Small Spacecraft Division at NASA Ames Research Center, the 5.5-kg 3U satellite contains two completely independent payloads and a novel drag-enhancing device which shortens the spacecraft’s orbital lifetime, thereby mitigating orbital debris. This paper provides an overview of the mission as well as an in-depth discussion of each payload and the de-orbit mechanism (DOM) while highlighting lessons learned from the spacecraft’s development