Mobility enhancement among older adults 75 + in rural areas: Study protocol of the MOBILE randomized controlled trial

Background: Maintaining mobility in old age is crucial for healthy ageing including delaying the onset and progress of frailty. However, the extent of an individuals' mobility relies largely on their personal, social, and environmental resources as outlined in the Life-Space Constriction Model. Recent studies mainly focus on facilitating habitual out-of-home mobility by fostering one type of resources only. The MOBILE trial aims at testing whether tablet-assisted motivational counselling enhances the mobility of community-dwelling older adults by addressing personal, social, and environmental resources. Methods: In the MOBILE randomized controlled trial, we plan to enrol 254 community-dwelling older adults aged 75 and older from Havelland, a rural area in Germany. The intervention group will receive a tablet-assisted motivational counselling at the participant's home and two follow-up telephone sessions. Main focus of the counselling sessions lays on setting and adapting individual mobility goals and applying action planning and habit formation strategies by incorporating the personal social network and regional opportunities for engaging in mobility related activities. The control group will receive postal general health information. The primary mobility outcome is time out-of-home assessed by GPS (GPS.Rec2.0-App) at three points in time (baseline, after one month, and after three months for seven consecutive days each). Secondary outcomes are the size of the GPS-derived life-space convex hull, self-reported life-space mobility (LSA-D), physical activity (IPAQ), depressive symptoms (GDS), frailty phenotype, and health status (SF-12). Discussion: The MOBILE trial will test the effect of a motivational counselling intervention on out-of-home mobility in community-dwelling older adults. Novel aspects of the MOBILE trial include the preventive multi-level intervention approach in combination with easy-to-use technology. The ecological approach ensures low-threshold implementation, which increases the benefit for the people in the region

Effect of Nuclear Quadrupole Interaction on the Relaxation in Amorphous Solids

Recently it has been experimentally demonstrated that certain glasses display an unexpected magnetic field dependence of the dielectric constant. In particular, the echo technique experiments have shown that the echo amplitude depends on the magnetic field. The analysis of these experiments results in the conclusion that the effect seems to be related to the nuclear degrees of freedom of tunneling systems. The interactions of a nuclear quadrupole electrical moment with the crystal field and of a nuclear magnetic moment with magnetic field transform the two-level tunneling systems inherent in amorphous dielectrics into many-level tunneling systems. The fact that these features show up at temperatures $T<100mK$, where the properties of amorphous materials are governed by the long-range $R^{-3}$ interaction between tunneling systems, suggests that this interaction is responsible for the magnetic field dependent relaxation. We have developed a theory of many-body relaxation in an ensemble of interacting many-level tunneling systems and show that the relaxation rate is controlled by the magnetic field. The results obtained correlate with the available experimental data. Our approach strongly supports the idea that the nuclear quadrupole interaction is just the key for understanding the unusual behavior of glasses in a magnetic field.Comment: 18 pages, 9 figure

International expert consensus on a scientific approach to training novice cardiac resynchronization therapy implanters using performance quality metrics

Aims: Pacing and Cardiac Resynchronization Therapy (CRT) procedural training for novice operators usually takes place in-vivo and methods vary across countries/institutions. No common system exists to objectively assess trainee ability to perform required tasks at predetermined performance levels prior to in-vivo practice. We sought to characterize and validate with experts a reference approach to pacing/CRT implants based on objective and explicit performance quality metrics, for the development of a reproducible, simulation-based, training curriculum aiming to operator proficiency. Methods: Three experienced CRT implanters, a behavioural scientist and two engineers performed a detailed task deconstruction of the pacing/CRT procedure and identified the performance metrics (phases, steps, errors, critical errors) that constitute an optimal CRT implant for training purposes. The metrics were stress tested to determine reliability and score-ability and then subjected to detailed systematic review by an international panel of 15 expert implanters in a modified Delphi process. Results: Thirteen procedure phases were identified, consisting of 196 steps, 122 errors, 50 critical errors. The expert panel deliberation added 16 metrics, deleted 12, and modified 43. Unanimous panel consensus on the resulting CRT procedure metrics was obtained, which verified face and content validity. Conclusion: A reference pacing/CRT procedure and metrics created by a core group of experts accurately characterize the essential components of performance and were endorsed by an international panel of experienced peers. The metrics will underpin quality-assured novice implanter training

International expert consensus on a scientific approach to training novice cardiac resynchronization therapy implanters using performance quality metrics

Aims: Pacing and Cardiac Resynchronization Therapy (CRT) procedural training for novice operators usually takes place in-vivo and methods vary across countries/institutions. No common system exists to objectively assess trainee ability to perform required tasks at predetermined performance levels prior to in-vivo practice. We sought to characterize and validate with experts a reference approach to pacing/CRT implants based on objective and explicit performance quality metrics, for the development of a reproducible, simulation-based, training curriculum aiming to operator proficiency. Methods: Three experienced CRT implanters, a behavioural scientist and two engineers performed a detailed task deconstruction of the pacing/CRT procedure and identified the performance metrics (phases, steps, errors, critical errors) that constitute an optimal CRT implant for training purposes. The metrics were stress tested to determine reliability and score-ability and then subjected to detailed systematic review by an international panel of 15 expert implanters in a modified Delphi process. Results: Thirteen procedure phases were identified, consisting of 196 steps, 122 errors, 50 critical errors. The expert panel deliberation added 16 metrics, deleted 12, and modified 43. Unanimous panel consensus on the resulting CRT procedure metrics was obtained, which verified face and content validity. Conclusion: A reference pacing/CRT procedure and metrics created by a core group of experts accurately characterize the essential components of performance and were endorsed by an international panel of experienced peers. The metrics will underpin quality-assured novice implanter training

The Insulin-Mediated Modulation of Visually Evoked Magnetic Fields Is Reduced in Obese Subjects

BACKGROUND: Insulin is an anorexigenic hormone that contributes to the termination of food intake in the postprandial state. An alteration in insulin action in the brain, named "cerebral insulin resistance", is responsible for overeating and the development of obesity. METHODOLOGY/PRINCIPAL FINDINGS: To analyze the direct effect of insulin on food-related neuronal activity we tested 10 lean and 10 obese subjects. We conducted a magnetencephalography study during a visual working memory task in both the basal state and after applying insulin or placebo spray intranasally to bypass the blood brain barrier. Food and non-food pictures were presented and subjects had to determine whether or not two consecutive pictures belonged to the same category. Intranasal insulin displayed no effect on blood glucose, insulin or C-peptide concentrations in the periphery; however, it led to an increase in the components of evoked fields related to identification and categorization of pictures (at around 170 ms post stimuli in the visual ventral stream) in lean subjects when food pictures were presented. In contrast, insulin did not modulate food-related brain activity in obese subjects. CONCLUSIONS/SIGNIFICANCE: We demonstrated that intranasal insulin increases the cerebral processing of food pictures in lean whereas this was absent in obese subjects. This study further substantiates the presence of a "cerebral insulin resistance" in obese subjects and might be relevant in the pathogenesis of obesity

Gender and Weight Shape Brain Dynamics during Food Viewing

Hemodynamic imaging results have associated both gender and body weight to variation in brain responses to food-related information. However, the spatio-temporal brain dynamics of gender-related and weight-wise modulations in food discrimination still remain to be elucidated. We analyzed visual evoked potentials (VEPs) while normal-weighted men (n = 12) and women (n = 12) categorized photographs of energy-dense foods and non-food kitchen utensils. VEP analyses showed that food categorization is influenced by gender as early as 170 ms after image onset. Moreover, the female VEP pattern to food categorization co-varied with participants' body weight. Estimations of the neural generator activity over the time interval of VEP modulations (i.e. by means of a distributed linear inverse solution [LAURA]) revealed alterations in prefrontal and temporo-parietal source activity as a function of image category and participants' gender. However, only neural source activity for female responses during food viewing was negatively correlated with body-mass index (BMI) over the respective time interval. Women showed decreased neural source activity particularly in ventral prefrontal brain regions when viewing food, but not non-food objects, while no such associations were apparent in male responses to food and non-food viewing. Our study thus indicates that gender influences are already apparent during initial stages of food-related object categorization, with small variations in body weight modulating electrophysiological responses especially in women and in brain areas implicated in food reward valuation and intake control. These findings extend recent reports on prefrontal reward and control circuit responsiveness to food cues and the potential role of this reactivity pattern in the susceptibility to weight gain

Electromechanically optimized cardiac pacing through prevention of unneeded and improved application of required stimulation

Elektromechanische myokardiale Asynchronie ist als bedeutsamer Kofaktor an der Verursachung oder Verschlechterung einer Herzinsuffizienz beteiligt und begünstigt das Auftreten von Herzrhythmusstörungen. Myokardiale Asynchronie kann durch konventionelle Kammerstimulation verursacht und durch kardiale Resynchronisationstherapie gemindert werden. Die vorliegende Arbeit befasst sich mit der Pathophysiologie der kardialen Asynchronie und diskutiert Strategien zur elektromechanischen Optimierung der Herzschrittmachertherapie durch Vermeidung unnötiger und verbesserte Applikation indizierter Schrittmacherstimulation.Electromechanical myocardial dyssynchrony is an important cofactor favoring the development and impairment of heart failure and promoting arrhythmias. Myocardial dyssynchrony can be produced by conventional ventricular pacing and can be attenuated through cardiac resynchronization therapy. This publication is concerned with the pathophysiology of cardiac dyssynchrony and discusses strategies to optimize cardiac pacing through prevention of unneeded stimulation and improved application of required pacing

Optimal CRT Implantation—Where and How To Place the Left-Ventricular Lead?

Purpose of review!#!Cardiac resynchronization therapy (CRT) represents a well-established and effective non-pharmaceutical heart failure (HF) treatment in selected patients. Still, a significant number of patients remain CRT non-responders. An optimal placement of the left ventricular (LV) lead appears crucial for the intended hemodynamic and hence clinical improvement. A well-localized target area and tools that help to achieve successful lead implantation seem to be of utmost importance to reach an optimal CRT effect.!##!Recent findings!#!Recent studies suggest previous multimodal imaging (CT/cMRI/ECG torso) to guide intraprocedural LV lead placement. Relevant benefit compared to empirical lead optimization is still a matter of debate. Technical improvements in leads and algorithms (e.g., multipoint pacing (MPP), adaptive algorithms) promise higher procedural success. Recently emerging alternatives for ventricular synchronization such as conduction system pacing (CSP), LV endocardial pacing, or leadless pacing challenge classical biventricular pacing. This article reviews current strategies for a successful planning, implementation, and validation of the optimal CRT implantation. Pre-implant imaging modalities offer promising assistance for complex cases; empirical lead positioning and intraoperative testing remain the cornerstone in most cases and ensure a successful CRT effect