85 research outputs found
Behavioral effects of continuous theta-burst stimulation in macaque parietal cortex
The neural mechanisms underlying the effects of continuous Theta-Burst Stimulation (cTBS) in humans are poorly understood. Animal studies can clarify the effects of cTBS on individual neurons, but behavioral evidence is necessary to demonstrate the validity of the animal model. We investigated the behavioral effect of cTBS applied over parietal cortex in rhesus monkeys performing a visually-guided grasping task with two differently sized objects, which required either a power grip or a pad-to-side grip. We used Fitts’ law, predicting shorter grasping times (GT) for large compared to small objects, to investigate cTBS effects on two different grip types. cTBS induced long-lasting object-specific and dose-dependent changes in GT that remained present for up to two hours. High-intensity cTBS increased GTs for a power grip, but shortened GTs for a pad-to-side grip. Thus, high-intensity stimulation strongly reduced the natural GT difference between objects (i.e. the Fitts’ law effect). In contrast, low-intensity cTBS induced the opposite effects on GT. Modifying the coil orientation from the standard 45-degree to a 30-degree angle induced opposite cTBS effects on GT. These findings represent behavioral evidence for the validity of the nonhuman primate model to study the neural underpinnings of non-invasive brain stimulation.Fonds voor Wetenschappelijk Onderzoek Vlaanderen, Odysseus (G.0007.12, G.0C51.13N)
The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
The Photodetector Array Camera and Spectrometer (PACS) is one of the three
science instruments on ESA's far infrared and submillimetre observatory. It
employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16x25
pixels, each, and two filled silicon bolometer arrays with 16x32 and 32x64
pixels, respectively, to perform integral-field spectroscopy and imaging
photometry in the 60-210\mu\ m wavelength regime. In photometry mode, it
simultaneously images two bands, 60-85\mu\ m or 85-125\mu\m and 125-210\mu\ m,
over a field of view of ~1.75'x3.5', with close to Nyquist beam sampling in
each band. In spectroscopy mode, it images a field of 47"x47", resolved into
5x5 pixels, with an instantaneous spectral coverage of ~1500km/s and a spectral
resolution of ~175km/s. We summarise the design of the instrument, describe
observing modes, calibration, and data analysis methods, and present our
current assessment of the in-orbit performance of the instrument based on the
Performance Verification tests. PACS is fully operational, and the achieved
performance is close to or better than the pre-launch predictions
Lysine acetylation regulates the interaction between proteins and membranes
Lysine acetylation regulates the function of soluble proteins in vivo, yet it remains largely unexplored whether lysine acetylation regulates membrane protein function. Here, we use bioinformatics, biophysical analysis of recombinant proteins, live-cell fluorescent imaging and genetic manipulation of Drosophila to explore lysine acetylation in peripheral membrane proteins. Analysis of 50 peripheral membrane proteins harboring BAR, PX, C2, or EHD membrane-binding domains reveals that lysine acetylation predominates in membrane-interaction regions. Acetylation and acetylation-mimicking mutations in three test proteins, amphiphysin, EHD2, and synaptotagmin1, strongly reduce membrane binding affinity, attenuate membrane remodeling in vitro and alter subcellular localization. This effect is likely due to the loss of positive charge, which weakens interactions with negatively charged membranes. In Drosophila, acetylation-mimicking mutations of amphiphysin cause severe disruption of T-tubule organization and yield a flightless phenotype. Our data provide mechanistic insights into how lysine acetylation regulates membrane protein function, potentially impacting a plethora of membrane-related processes
Effectiveness of a nurse-supported self-management programme for dual sensory impaired older adults in long-term care: a cluster randomised controlled trial
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190314.pdf (publisher's version ) (Open Access)OBJECTIVE: To evaluate the effectiveness of a nurse-supported self-management programme to improve social participation of dual sensory impaired older adults in long-term care homes. DESIGN: Cluster randomised controlled trial. SETTING: Thirty long-term care homes across the Netherlands. PARTICIPANTS: Long-term care homes were randomised into intervention clusters (n=17) and control clusters (n=13), involving 89 dual sensory impaired older adults and 56 licensed practical nurses. INTERVENTION: Nurse-supported self-management programme. MEASUREMENTS: Effectiveness was evaluated by the primary outcome social participation using a participation scale adapted for visually impaired older adults distinguishing four domains: instrumental activities of daily living, social-cultural activities, high-physical-demand and low-physical-demand leisure activities. A questionnaire assessing hearing-related participation problems was added as supportive outcome. Secondary outcomes were autonomy, control, mood and quality of life and nurses' job satisfaction. For effectiveness analyses, linear mixed models were used. Sampling and intervention quality were analysed using descriptive statistics. RESULTS: Self-management did not affect all four domains of social participation; however. the domain 'instrumental activities of daily living' had a significant effect in favour of the intervention group (P=0.04; 95% CI 0.12 to 8.5). Sampling and intervention quality was adequate. CONCLUSIONS: A nurse-supported self-management programme was effective in empowering the dual sensory impaired older adults to address the domain 'instrumental activities of daily living', but no differences were found in addressing the other three participation domains. Self-management showed to be beneficial for managing practical problems, but not for those problems requiring behavioural adaptations of other persons. TRIAL REGISTRATION NUMBER: NCT01217502; Results
Problems identified by dual sensory impaired older adults in long-term care when using a self-management program: A qualitative study
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170080.pdf (publisher's version ) (Open Access)OBJECTIVE: To gain insights into the problems of dual sensory impaired older adults in long-term care. Insights into these problems are essential for developing adequate policies which address the needs of the increasing population of dual sensory impaired older adults in long-term care. METHODS: A qualitative study was conducted in parallel with a cluster randomized controlled trial. Dual sensory impaired older adults in the intervention group (n = 47, age range 82-98) were invited by a familiar nurse to identify the problems they wanted to address. Data were taken from the semi-structured intervention diaries in which nurses noted the older adults' verbal responses during a five-month intervention period in 17 long-term care homes across the Netherlands. The data were analyzed using descriptive statistics and qualitative content analysis based on the Grounded Theory. FINDINGS: The 47 dual sensory impaired older adults identified a total of 122 problems. Qualitative content analysis showed that the older adults encountered participation problems and problems controlling what happens in their personal environment. Three categories of participation problems emerged: (1) existential concerns of not belonging or not being able to connect with other people, (2) lack of access to communication, information and mobility, and (3) the desire to be actively involved in care delivery. Two categories of control-in-personal-space problems emerged: (1) lack of control of their own physical belongings, and (2) lack of control regarding the behavior of nurses providing daily care in their personal environment. CONCLUSIONS: The invasive problems identified indicate that dual sensory impaired older adults experience great existential pressures on their lives. Long-term care providers need to develop and implement policies that identify and address these problems, and be aware of adverse consequences of usual care, in order to improve dual sensory impaired residents' autonomy and quality of life
Flip-chip joined 8X8 array of bottom-emitting 850-nm light-emitting diodes for interconnect applications
We present an array of GaAs-based light-emitting diodes emitting at 850 nm, which is designed to be flip-chip joined on carriers like a silicon CMOS circuit. The light-emitting diodes are grown by MBE. After processing of the array and flip-chip joining using Indium-bumps, the substrate of the LED array is removed completely. Individual light-emitting diodes reach an external quantum efficiency of 3.3% after the complete process.status: publishe
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