Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

Choreographing life-experiences of balance control in people with Parkinson’s disease

CITATION: LaGrone, S., et al. 2020. Choreographing life-experiences of balance control in people with Parkinson’s disease. BMC Neurology, 20:50, doi:10.1186/s12883-020-01632-4.The original publication is available at https://bmcneurol.biomedcentral.comBackground: Parkinson’s disease (PD) is a devastating neurodegenerative disorder. Reduced balance is one of the cardinal symptoms of PD, predisposing people living with PD to experience difficulties with the execution of tasks and activities, as well as hindering their involvement in meaningful life areas. The overarching aim of this study was to explore how deficits in balance control manifest in everyday life and how it is managed by people with PD (PwPD). Methods: Qualitative description was used as methodology, and in-depth interviews were conducted with 18 participants, between the ages of 46 to 83 years, with mild to severe PD. Interview transcripts were analyzed using qualitative content analysis, following an inductive approach. Results: One theme emerged from the analysis: Increased planning—choreographing life. Within this overarching theme, two categories were identified, namely Limitations in mobility and New restricted functioning in everyday life, each with 3–4 sub-categories. The categories described how PwPD handled decreased balance control in their everyday life by using motor and cognitive strategies as a consequence of not trusting their body’s capacity to control balance. Activities in everyday life, as well as the ability to partake in leisure and social activities were profoundly affected. Conclusion: People with mild to severe PD used strategies to handle decreased balance and they choreographed their lives around their individual current state of mobility and balance. The knowledge gained from this study can be used to develop targeted interventions addressing the nuances of balance deficits in everyday life.https://bmcneurol.biomedcentral.com/articles/10.1186/s12883-020-01632-4Publisher's versio

Characterization of Mild and Moderate Dysarthria in Parkinson's Disease : Behavioral Measures and Neural Correlates

PurposeAlterations in speech and voice are among the most common symptoms in Parkinson's disease (PD), often resulting in motor speech disorders such as hypokinetic dysarthria. We investigated dysarthria, verbal fluency, executive functions, and global cognitive function in relation to structural and resting-state brain changes in people with PD. MethodsParticipants with mild-moderate PD (n = 83) were recruited within a randomized controlled trial and divided into groups with varying degrees of dysarthria: no dysarthria (noDPD), mild dysarthria (mildDPD), moderate dysarthria (modDPD), and also combined mildDPD and modDPD into one group (totDPD). Voice sound level and dysphonia, verbal fluency, motor symptoms, executive functions, disease severity, global cognition, and neuroimaging were compared between groups. Gray matter volume and intensity of spontaneous brain activity were analyzed. Additionally, regressions between behavioral and neuroimaging data were performed. ResultsThe groups differed significantly in mean voice sound level, dysphonia, and motor symptom severity. Comparing different severity levels of dysarthria to noDPD, groups differed focally in resting-state activity, but not in brain structure. In totDPD, lower scores on semantic verbal fluency, a composite score of executive functions, and global cognition correlated with lower superior temporal gyrus volume. ConclusionThis study shows that severity of dysarthria may be related to underlying structural and resting-state brain alterations in PD as well as behavioral changes. Further, the superior temporal gyrus may play an important role in executive functions, language, and global cognition in people with PD and dysarthria

Implementation of highly challenging balance training for Parkinson’s disease in clinical practice : a process evaluation

CITATION: Leavy, B., et al. 2021. Implementation of highly challenging balance training for Parkinson’s disease in clinical practice : a process evaluation. BMC Geriatrics, 21:96, doi:10.1186/s12877-021-02031-1.The original publication is available at https://bmcgeriatr.biomedcentral.comBackground: Process evaluations provide contextual insight into the way in which interventions are delivered. This information is essential when designing strategies to implement programs into wider clinical practice. We performed a process evaluation of the HiBalance effectiveness trial investigating the effects of a 10-week of highly challenging and progressive balance training for mild-moderate Parkinson’s disease (PD). Study aims were to investigate i) the quality and quantity of intervention delivery and ii) barriers and facilitators for implementation. Methods: Process outcomes included; Fidelity; Dose (delivered and received) Recruitment and Reach. Investigation of barriers and facilitators was guided by the Consolidated Framework for Implementation Research. Program delivery was assessed across four neurological rehabilitation sites during a two-year period. Data collection was mixed-methods in nature and quantitative and qualitative data were merged during the analysis phase. Results: Thirteen program trainers delivered the intervention to 12 separate groups during 119 training sessions. Trainer fidelity to program core components was very high in 104 (87%) of the sessions. Participant responsiveness to the core components was generally high, although adherence to the home exercise program was low (50%). No significant context-specific differences were observed across sites in terms of fidelity, dose delivered/ received or participant characteristics, despite varying recruitment methods. Facilitators to program delivery were; PD-specificity, high training frequency and professional autonomy. Perceived barriers included; cognitive impairment, absent reactional balance among participants, as well a heterogeneous group in relation to balance capacity. Conclusion: These findings provide corroborating evidence for outcome evaluation results and valuable information for the further adaptation and implementation of this program. Important lessons can also be learned for researchers and clinicians planning to implement challenging exercise training programs for people with mildmoderate PD.https://bmcgeriatr.biomedcentral.com/articles/10.1186/s12877-021-02031-1Publisher's versio

Feasibility of preoperative supervised home-based exercise in older adults undergoing colorectal cancer surgery - A randomized controlled design

Preoperative physical exercise is emerging as a growing field of research globally. There are still challenges in recruiting vulnerable older people, and time constraints in preoperative cancer care to consider. We therefore evaluated the feasibility of short-term supervised home-based exercise in older people prior to colorectal cancer surgery. This feasibility study was conducted between September 2016 and June 2018. People ≥70 years scheduled for colorectal cancer surgery were recruited and randomized to an intervention group receiving supervised home-based physical exercise at a high level of estimated exertion or a standard care group following the standard preoperative path. The exercise (respiratory, strength, and aerobic) consisted of 2-3 supervised sessions a week in the participants' homes, for at least 2-3 weeks or until surgery, and a self-administered exercise program in between. The primary outcome was process feasibility, including aspects specifically related to recruitment rate, compliance to the intervention, and acceptability. The secondary outcome was scientific feasibility including treatment safety, description of dose level and response, and estimation of treatment results. Twenty-three participants were included (recruitment rate 35%). A median of 6 supervised sessions was conducted over a 17-day exercise period. Compliance with the supervised sessions was 97%, and participants found the intervention acceptable. Concerning the self-administered exercise, a median of 19 inspiratory muscle training, 6 functional strength, and 8.5 aerobic sessions were reported. Challenges reported by program instructors were time constraints and difficulties in achieving high exercise intensities on the Borg CR-10 scale. A statistically significant between-group difference was only found in inspiratory muscle strength, favoring the intervention group (p<0.01). A short-term preoperative supervised home-based physical exercise intervention can be conducted, with respect to compliance and acceptability, in older people with similar physical status as in this study prior to colorectal cancer surgery. However, modifications are warranted with respect to improving recruitment rates and achieving planned intensity levels prior to conducting a definitive trial

A study protocol of Older Person's Exercise and Nutrition Study (OPEN) - a sit-to-stand activity combined with oral protein supplement - effects on physical function and independence : a cluster randomized clinical trial

Background: Poor nutrition and age per see add to the development of sarcopenia, i.e. loss of muscle mass and strength, which contributes to increased risk of impaired activities of daily living (ADL) and reduced independence. Protein deficiency plays an important role in the development of sarcopenia. In order to increase the muscle mass protein intake should be combined with physical exercise. A daily physical activity, the sit-to-stand exercise, has been proven to decrease older persons' dependence in ADL. Our study aims to evaluate the effects of the sit-to-stand exercise in combination with a protein-rich nutritional supplement, on physical function and independence in frail nursing home residents. The resident's perceptions and experiences of the intervention and the staff's experiences of supporting the resident to complete the intervention will also be explored. Methods: The study is a two-arm cluster-randomized controlled trial which will be performed in nursing homes at two municipalities in Sweden. We will recruit 120 residents, age 75 or older and able to stand up from a seated position. Residents (n = 60) randomized to the intervention group will perform the sit-to-stand exercise at four occasions daily and will be offered a protein-rich oral supplement, twice a day. The intervention period will last for 12 weeks and measures of physical function, nutritional status, quality of life and health economy will be performed at baseline and at 12-weeks follow-up. The primary outcome will be the number of chair rises performed in 30 s. The control group will receive standard care. Data will be analysed by intention-to-treat analysis and with mixed effect models. During the last part of the intervention period individual interviews with the residents, on the topic of feasibility with the OPEN concept will be held. Likewise, focus-group-interviews with staff will be performed. Discussion: The residents' physical and mental health could be expected to improve. Even the work situation for staff could be positively affected. One innovative feature of the OPEN study is the simple intervention consisting of a basic daily activity that can be performed by several nursing home residents with the support of existing staff and available resources

Elevated Ventral Striatal Reactivity to Reward Following Sleep Deprivation

Sleep loss produces abnormal increases in reward-seeking, though the mechanisms underlying this phenomenon are poorly understood. In this study we examined the impact of sleep deprivation upon reward neural circuitry in healthy young adults using fMRI and a well-validated monetary reward paradigm.\ud \ud We found that activity in the ventral striatum and medial prefrontal cortex were significantly greater during reward trials under sleep-deprived versus rested conditions. Our findings suggest that sleep loss produces aberrant functioning in reward neural circuitry, possibly resulting in over-valuation of positively-reinforcing stimuli. In addition, sleep deprivation appeared to induce a failure to deactivate midline default-mode network structures during task performance, potentially interfering with efficient reward-related decision making. We believe these findings demonstrate how chronic sleep loss might contribute to the development and maintenance of psychiatric conditions in which sleep disturbance and abnormal reward behaviors co-occur

A study protocol of Older Person's Exercise and Nutrition Study (OPEN) - a sit-to-stand activity combined with oral protein supplement - effects on physical function and independence : a cluster randomized clinical trial

Background: Poor nutrition and age per see add to the development of sarcopenia, i.e. loss of muscle mass and strength, which contributes to increased risk of impaired activities of daily living (ADL) and reduced independence. Protein deficiency plays an important role in the development of sarcopenia. In order to increase the muscle mass protein intake should be combined with physical exercise. A daily physical activity, the sit-to-stand exercise, has been proven to decrease older persons' dependence in ADL. Our study aims to evaluate the effects of the sit-to-stand exercise in combination with a protein-rich nutritional supplement, on physical function and independence in frail nursing home residents. The resident's perceptions and experiences of the intervention and the staff's experiences of supporting the resident to complete the intervention will also be explored. Methods: The study is a two-arm cluster-randomized controlled trial which will be performed in nursing homes at two municipalities in Sweden. We will recruit 120 residents, age 75 or older and able to stand up from a seated position. Residents (n = 60) randomized to the intervention group will perform the sit-to-stand exercise at four occasions daily and will be offered a protein-rich oral supplement, twice a day. The intervention period will last for 12 weeks and measures of physical function, nutritional status, quality of life and health economy will be performed at baseline and at 12-weeks follow-up. The primary outcome will be the number of chair rises performed in 30 s. The control group will receive standard care. Data will be analysed by intention-to-treat analysis and with mixed effect models. During the last part of the intervention period individual interviews with the residents, on the topic of feasibility with the OPEN concept will be held. Likewise, focus-group-interviews with staff will be performed. Discussion: The residents' physical and mental health could be expected to improve. Even the work situation for staff could be positively affected. One innovative feature of the OPEN study is the simple intervention consisting of a basic daily activity that can be performed by several nursing home residents with the support of existing staff and available resources