A Basis Theorem for Perfect Sets

We show that if there is a nonconstructible real, then every perfect set has a nonconstructible element, answering a question of K. Prikry. This is a specific instance of a more general theorem giving a sufficient condition on a pair M ⊂ N of models of set theory implying that every perfect set in N has an element in N which is not in M

Promoting a Healthy Lifestyle

__Abstract__ In this thesis, the effectiveness of the Active Lifestyle and Sports participation intervention was evaluated among youth with Cerebral Palsy (CP). This intervention consisted of ADL counselling, fitness training and sports counselling. It was hypothesised that this lifestyle intervention would have added value for improving physical behaviour and physical fitness compared to regular therapy. We found that persons with CP had significantly lower levels of physical fitness and physical activity compared to a reference sample. These reduced levels were accompanied by increased levels of fatigue. The longitudinal analyses showed that the lifestyle intervention had favourable effects on self-reported physical activity and various components of physical fitness. Furthermore, fatigue severity was reduced after following the intervention. No effects for the intervention were found on objectively measured physical activity, quality of life and socila participation. Exploratory results of the cost-utility analysis showed that offering a lifestyle intervention for CP-populations might be cost-effective or cost-saving as compared to offering no intervention to improve physical behaviour and fitness

Multimodal probe for optical coherence tomography epidetection and micron-scale indentation

We present a multimodal ferrule-top sensor designed to perform the integrated epidetection of Optical Coherence Tomography (OCT) depth-profiles and micron-scale indentation by all-optical detection. By scanning a sample under the probe, we can obtain structural cross-section images and identify a region-of-interest in a nonhomogeneous sample. Then, with the same probe and setup, we can immediately target that area with a series of spherical-indentation measurements, in which the applied load is known with a μN precision, the indentation depth with sub-μm precision and a maximum contact radius of 100μm. Thanks to the visualization of the internal structure of the sample, we can gain a better insight into the observed mechanical behavior. The ability to impart a small, confined load, and perform OCT A-scans at the same time, could lead to an alternative, high transverse resolution, Optical Coherence Elastography (OCE) sensor

Mg/Ti multilayers: structural, optical and hydrogen absorption properties

Mg-Ti alloys have uncommon optical and hydrogen absorbing properties, originating from a "spinodal-like" microstructure with a small degree of chemical short-range order in the atoms distribution. In the present study we artificially engineer short-range order by depositing Pd-capped Mg/Ti multilayers with different periodicities and characterize them both structurally and optically. Notwithstanding the large lattice parameter mismatch between Mg and Ti, the as-deposited metallic multilayers show good structural coherence. Upon exposure to H2 gas a two-step hydrogenation process occurs, with the Ti layers forming the hydride before Mg. From in-situ measurements of the bilayer thickness L at different hydrogen pressures, we observe large out-of-plane expansions of the Mg and Ti layers upon hydrogenation, indicating strong plastic deformations in the films and a consequent shortening of the coherence length. Upon unloading at room temperature in air, hydrogen atoms remain trapped in the Ti layers due to kinetic constraints. Such loading/unloading sequence can be explained in terms of the different thermodynamic properties of hydrogen in Mg and Ti, as shown by diffusion calculations on a model multilayered systems. Absorption isotherms measured by hydrogenography can be interpreted as a result of the elastic clamping arising from strongly bonded Mg/Pd and broken Mg/Ti interfaces

Inactive and sedentary lifestyles amongst ambulatory adolescents and young adults with cerebral palsy

Background: To assess physical behaviour, including physical activity and sedentary behaviour, of ambulatory adolescents and young adults with cerebral palsy (CP). We compared participant physical behaviour to that of able-bodied persons and assessed differences related to Gross Motor Functioning Classification System (GMFCS) level and CP distribution (unilateral/bilateral). Methods. In 48 ambulatory persons aged 16 to 24 years with spastic CP and in 32 able-bodied controls, physical behaviour was objectively determined with an accelerometer-based activity monitor. Total duration, intensity and type of physical activity were assessed and sedentary time was determined (lying and sitting). Furthermore, distribution of walking bouts and sitting bouts was specified. Results: Adolescents and young adults with CP spent 8.6% of 24 hours physically active and 79.5% sedentary, corresponding with respectively 123 minutes and 1147 minutes per 24 hours. Compared to able-bodie

Inactive and sedentary lifestyles amongst ambulatory adolescents and young adults with cerebral palsy

textabstractBackground: To assess physical behaviour, including physical activity and sedentary behaviour, of ambulatory adolescents and young adults with cerebral palsy (CP). We compared participant physical behaviour to that of able-bodied persons and assessed differences related to Gross Motor Functioning Classification System (GMFCS) level and CP distribution (unilateral/bilateral). Methods. In 48 ambulatory persons aged 16 to 24 years with spastic CP and in 32 able-bodied controls, physical behaviour was objectively determined with an accelerometer-based activity monitor. Total duration, intensity and type of physical activity were assessed and sedentary time was determined (lying and sitting). Furthermore, distribution of walking bouts and sitting bouts was specified. Results: Adolescents and young adults with CP spent 8.6% of 24 hours physically active and 79.5% sedentary, corresponding with respectively 123 minutes and 1147 minutes per 24 hours. Compared to able-bodie

Ferrule-top nanoindenter: An optomechanical fiber sensor for nanoindentation

Ferrule-top probes are self-aligned all-optical devices obtained by fabricating a cantilever on the top of a ferruled optical fiber. This approach has been proven to provide a new platform for the realization of small footprint atomic force microscopes (AFMs) that adapt well to utilization outside specialized laboratories [D. Chavan, Rev. Sci. Instrum. 81, 123702 (2010)10.1063/1.3516044; D. Chavan, Rev. Sci. Instrum. 82, 046107 (2011)10.1063/1.3579496]. In this paper we now show that ferrule-top cantilevers can be also used to develop nanoindenters. Our instrument combines the sensitivity of commercial AFM-based indentation with the ease-of-use of more macroscopic instrumented indenters available today on the market. Furthermore, the all-optical design allows smooth operations also in liquids, where other devices are much more limited and often provide data that are difficult to interpret. This study may pave the way to the implementation of a new generation user-friendly nanoindenters for the measurement of the stiffness of samples in material sciences and medical research. © 2012 American Institute of Physics

Learn 2 Move 16-24: Effectiveness of an intervention to stimulate physical activity and improve physical fitness of adolescents and young adults with spastic cerebral palsy; a randomized controlled trial

Background: Persons with cerebral palsy (CP) are at risk for developing an inactive lifestyle and often have poor fitness levels, which may lead to secondary health complications and diminished participation and quality of life. However, persons with CP also tend not to receive structural treatment to improve physical activity and fitness in adolescence, which is precisely the period when adult physical activity patterns are established.Methods: We aim to include 60 adolescents and young adults (16-24 ye