Compensatory Arm Reactions in Individuals with Parkinson’s Disease

This study examined how perturbation-evoked compensatory arm reactions in individuals with Parkinson’s disease (PD) are influenced by explicit verbal instruction. Ten individuals with PD and 15 older adults without PD responded to surface translations with or without specific instruction to reach for and grasp the handrail. Electromyographic (EMG) and kinematic recordings were taken from the reaching arm. Results showed that individuals with and without PD benefitted similarly from explicit instruction. Explicit instruction resulted in earlier (p=0.005) and larger (p<0.001) medial deltoid EMG responses in comparison to no specific instructions. Compensatory arm reactions also occurred with a higher peak medio-lateral wrist velocity (p<0.001) and higher peak shoulder abduction angular velocity (p<0.001) with explicit instruction. Explicit instruction positively influenced compensatory arm reactions in individuals with and without PD. Future research is needed to determine whether the benefits of instruction persist over time and translate to a loss of balance in real life

Goddard's Astrophysics Science Divsion Annual Report 2014

The Astrophysics Science Division (ASD, Code 660) is one of the world's largest and most diverse astronomical organizations. Space flight missions are conceived, built and launched to observe the entire range of the electromagnetic spectrum, from gamma rays to centimeter waves. In addition, experiments are flown to gather data on high-energy cosmic rays, and plans are being made to detect gravitational radiation from space-borne missions. To enable these missions, we have vigorous programs of instrument and detector development. Division scientists also carry out preparatory theoretical work and subsequent data analysis and modeling. In addition to space flight missions, we have a vibrant suborbital program with numerous sounding rocket and balloon payloads in development or operation. The ASD is organized into five labs: the Astroparticle Physics Lab, the X-ray Astrophysics Lab, the Gravitational Astrophysics Lab, the Observational Cosmology Lab, and the Exoplanets and Stellar Astrophysics Lab. The High Energy Astrophysics Science Archive Research Center (HEASARC) is an Office at the Division level. Approximately 400 scientists and engineers work in ASD. Of these, 80 are civil servant scientists, while the rest are resident university-based scientists, contractors, postdoctoral fellows, graduate students, and administrative staff. We currently operate the Swift Explorer mission and the Fermi Gamma-ray Space Telescope. In addition, we provide data archiving and operational support for the XMM mission (jointly with ESA) and the Suzaku mission (with JAXA). We are also a partner with Caltech on the NuSTAR mission. The Hubble Space Telescope Project is headquartered at Goddard, and ASD provides Project Scientists to oversee operations at the Space Telescope Science Institute. Projects in development include the Neutron Interior Composition Explorer (NICER) mission, an X-ray timing experiment for the International Space Station; the Transiting Exoplanet Sky Survey (TESS) Explorer mission, in collaboration with MIT (Ricker, PI); the Soft X-ray Spectrometer (SXS) for the Astro-H mission in collaboration with JAXA, and the James Webb Space Telescope (JWST). The Wide-Field Infrared Survey Telescope (WFIRST), the highest ranked mission in the 2010 decadal survey, is in a pre-phase A study, and we are supplying study scientists for that mission

New Insights into the Landing Phase of Reactive Stepping: Predictors of Control, Muscle Recruitment, Movement Restraints and Two-Step Responses

Preventing falls and fall-related injuries are public health challenges of the upmost importance for Canadians, particularly for older adults. Due to the severe consequences that can accompany a fall (e.g., traumatic brain injuries, hip fractures), studying age-related changes in balance control is an important avenue towards informing more effective fall-prevention interventions. As tripping is a common cause of falling in older adults, many researchers have studied reactive stepping after a simulated trip. While the majority of studies have focused on recovery at foot-contact (FC), researchers have begun to focus on the landing phase (or restabilisation phase), which occurs after the point of FC of the reactive step. This thesis adds to the burgeoning insights in this important area by addressing the following four general objectives: i) determine which individual characteristics are predictive of center of mass (COM) displacement during the reactive stepping and landing phases in young and older adults (Study 1); ii) determine how lower-limb muscle recruitment patterns during the landing phase compare to earlier phases of the reactive stepping response, as well as how lower-limb electromyography signals relate to each other during the landing phase (Study 2); iii) determine if wide stepping and restricted arm movement influence balance control during the landing phase (Study 3); and, iv) to quantify balance control after FC when participants responded with two reactive steps (Study 4). Reactive stepping was evoked via a tether-release paradigm. In Study 1, it was found that for both young and older adults, regression models driven by specific tether-release metrics were stronger predictors of COM movement during the stepping and landing phases compared to general metrics, calculated separately from the tether-release trials (e.g., response time, range-of-motion, etc.). For Study 2, which quantified lower-limb electromyography (EMG), the peak timing and magnitude were generally slower (more variable) and smallest from the point of the maximum COM after FC to the end of the trial. The muscles which exhibited their highest peak magnitude during the landing phase were the biceps femoris of the step-leg, which was correlated with the peak medial gastrocnemius magnitude during landing, and the rectus femoris and tibialis anterior of the support-leg. Peak magnitudes suggest that the step-leg biceps femoris and medial gastrocnemius and support-leg rectus femoris (in continuation from the swing phase) and tibialis anterior are important during landing, while the step-leg rectus femoris and tibialis anterior are important in the swing phase. Regarding the investigation of wide stepping and restricted arm movement in Study 3, wide stepping resulted in the largest medio-lateral (ML) and anterior-posterior (AP) body movement after FC, regardless of age group. Second, despite limited AP influence, restricted arm movement resulted in larger ML body movement after FC, compared to the preferred stepping condition. During Study 4, analyses of the first step revealed that during the two-step condition peak AP COM displacement after FC was increased, while peak ML COM displacement was decreased, for both loading conditions. With asymmetrical loading, first step lengths were larger during the one-step condition, while first step width was reduced over both stepping tasks with asymmetrical loading. During two-steps, peak AP extrapolated COM (xCOM) displacement after FC was larger in the second vs. the first step with asymmetrical loading, yet the first step resulted in greater ML xCOM displacement vs. the second step, regardless of loading. Interestingly, first step width was narrower than the second with asymmetrical loading. As hypothesized, peak xCOM displacement between the first and second steps was correlated. As a whole, the results of these studies provide novel insights into the landing phase of reactive stepping. A consistent theme pertains to the potential ability of pro-actively training effective reactive stepping responses. The findings suggest that researchers and clinicians should consider task specificity if training reactive stepping responses. Furthermore, focus should be placed on the muscles which were their most active (and correlated) during landing, (i.e., the biceps femoris and medial gastrocnemius of the step-leg). The large stability margin observed during wide stepping suggests it can be a positive strategy for increased ML stability. Incorporating the arms into training would also be positive, as ML COM control decreased when the arms were restricted. Finally, multi-step balance control should not be inferred using single-step responses, as differences in COM\xCOM displacement existed between stepping tasks and step number. Further, xCOM correlations between the first and second step did not improve when the one-step responses were used for the first step metrics. To further enhance the evidence base in this area, future work could focus on characterizing landing phase control during more dynamic activities such as tripping during gait, ideally with participants who represent high-fall risk groups

Goddard's Astrophysics Science Division Annual Report 2013

The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for two orbiting astrophysics missions Fermi Gamma-ray Space Telescope and Swift as well as the Science Support Center for Fermi. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical community, and enable future missions by conceiving new concepts and inventing new technologies

Concert recording 2018-11-26b

[Track 1]. The song of King David / Norman Bolter -- [Track 2]. Elegy for Mippy II / Leonard Bernstein -- [Track 3]. Sonata Vox Gabrieli / Stjepan Šulek -- [Track 4]. Reflective mood / Sammy Nestico -- [Track 5]. Gospel time / Jeffery Agrell

Possible Applications of Surface Electromagnetic Waves to Measure Absorption Coefficients

We Show that Surface Electromagnetic Waves Can Probably Be Used to Measure the Absorption Coefficients of Materials overlaying Metals. the Proposed Experimental Method is Illustrated in the Infrared Frequency Range using Water, Teflon, and Polyethylene as Sample Materials

Concert recording 2018-04-08a

[Track 1]. Sonatina. 1. [Track 2]. 2. [Track 3]. 3. / Halsey Stevens -- [Track 4]. Songs of a wayfarer. I. Wenn mein Schatz Hochzeit macht [Track 5]. II. Ging heut Morgen uber\u27s Feld [Track 6]. III. Ich hab\u27 ein gluhend Messer [Track 7]. IV. Die Zwei Blauen Augen / Gustav Mahler -- [Track 8]. Sonata in F minor. I. Andante cantabile [Track 9]. II. Allegro [Track 10]. III. Andante / Georg Philipp Telemann -- [Track 11]. 10 pieces for two bass trombones. 1. The hitch hiker [Track 12]. 6. Cashmere [Track 13]. 8. Below 10 street / Tommy Pederson -- [Track 14]. Gospel time / Jeffrey Agrell

Concert recording 2018-04-26

[Track 1]. Concerto no. 1 / Alexander Lebedev -- [Track 2]. Andante et allegro / Joseph Edouard Barat -- [Track 3]. Sonata for trombone and piano. III. Allegro ritmico e vigoroso / George McKay -- [Track 4]. Sonata in F minor, TWV 41:1. I. Andante cantabile [Track 5]. II. Allegro / Georg Philipp Telemann -- [Track 6]. Grand concerto / Friedebald Gräfe -- [Track 7]. Concerto for trombone. I. Andante maestoso - allegro molto - andante maestoso / Gordon Jacob -- [Track 8]. Concerto in one movement / Alexander Lebedev

Association rule mining to identify potential under-coding of conditions in the problem list in primary care electronic medical records

Introduction The problem list of a patient’s primary care electronic medical record (EMR) generally reflects their important medical conditions. We will use association rule mining to assess between-provider and between-clinic variation in the coding of select conditions in the EMR problem list, in order to identify possible under-coding outliers. Objectives and Approach EMR data from participating clinics in the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) will be used, with a focus on three commonly-occurring conditions (hypertension, diabetes, and depression). Association rule mining will be used to develop association rules between these conditions and other clinical information available in the EMR, such as other diagnoses in the problem list, billing codes, medications, and laboratory results (e.g., a rule of “diabetic medication→diabetes” indicates that patients prescribed a diabetic medication are likely to have diabetes in the problem list). Under-coding outliers at the provider and clinic levels will be identified by comparing rule enforcement. Results Results from this work in progress will be presented at the conference. An estimated 270 clinics, 1340 providers, and 1.8 million patients will be included from the CPCSSN database. Rule ‘confidence’ will be used to identify outliers; the confidence of a rule X→Y is the proportion of individuals with X who also have Y (Pr(Y|X)). For example, we may find that on average 80% of patients prescribed a diabetic medication will also have a diagnosis of diabetes in the problem list (average confidence of 80%), but an outlier clinic may have a confidence of 40%; this low rule confidence may indicate under-coding of diabetes in the problem list. Confounding by patient demographics (e.g., age, sex, urban/rural) will be assessed and adjusted for, if necessary. Conclusion/Implications This work examines a novel method to identify potential under-coding in the EMR problem list. Providers/clinics could use this information to update patients’ problem list or inform quality improvement interventions. Researchers using primary care EMR data need to be aware of potential under-coding and take steps to mitigate the effects