Exploring the relationships between International Classification of Functioning, Disability and Health (ICF) constructs of Impairment, Activity Limitation and Participation Restriction in people with osteoarthritis prior to joint replacement

<p>Abstract</p> <p>Background</p> <p>The International Classification of Functioning, Disability and Health (ICF) proposes three main constructs, impairment (I), activity limitation (A) and participation restriction (P). The ICF model allows for all paths between the constructs to be explored, with significant paths likely to vary for different conditions. The relationships between I, A and P have been explored in some conditions but not previously in people with osteoarthritis prior to joint replacement. The aim of this paper is to examine these relationships using separate measures of each construct and structural equation modelling.</p> <p>Methods</p> <p>A geographical cohort of 413 patients with osteoarthritis about to undergo hip and knee joint replacement completed the Aberdeen measures of Impairment, Activity Limitation and Participation Restriction (Ab-IAP). Confirmatory factor analysis was used to test the three factor (I, A, P) measurement model. Structural equation modelling was used to explore the I, A and P pathways in the ICF model.</p> <p>Results</p> <p>There was support from confirmatory factor analysis for the three factor I, A, P measurement model. The structural equation model had good fit [S-B Chi-square = 439.45, df = 149, CFI robust = 0.91, RMSEA robust = 0.07] and indicated significant pathways between I and A (standardised coefficient = 0.76 p < 0.0001) and between A and P (standardised coefficient = 0.75 p < 0.0001). However, the path between I and P was not significant (standardised coefficient = 0.01).</p> <p>Conclusion</p> <p>The significant pathways suggest that treatments and interventions aimed at reducing impairment, such as joint replacement, may only affect P indirectly, through A, however, longitudinal data would be needed to establish this.</p

Evidence That Two ATP-Dependent (Lon) Proteases in Borrelia burgdorferi Serve Different Functions

The canonical ATP-dependent protease Lon participates in an assortment of biological processes in bacteria, including the catalysis of damaged or senescent proteins and short-lived regulatory proteins. Borrelia spirochetes are unusual in that they code for two putative ATP-dependent Lon homologs, Lon-1 and Lon-2. Borrelia burgdorferi, the etiologic agent of Lyme disease, is transmitted through the blood feeding of Ixodes ticks. Previous work in our laboratory reported that B. burgdorferi lon-1 is upregulated transcriptionally by exposure to blood in vitro, while lon-2 is not. Because blood induction of Lon-1 may be of importance in the regulation of virulence factors critical for spirochete transmission, the clarification of functional roles for these two proteases in B. burgdorferi was the object of this study. On the chromosome, lon-2 is immediately downstream of ATP-dependent proteases clpP and clpX, an arrangement identical to that of lon of Escherichia coli. Phylogenetic analysis revealed that Lon-1 and Lon-2 cluster separately due to differences in the NH2-terminal substrate binding domains that may reflect differences in substrate specificity. Recombinant Lon-1 manifested properties of an ATP-dependent chaperone-protease in vitro but did not complement an E. coli Lon mutant, while Lon-2 corrected two characteristic Lon-mutant phenotypes. We conclude that B. burgdorferi Lons -1 and -2 have distinct functional roles. Lon-2 functions in a manner consistent with canonical Lon, engaged in cellular homeostasis. Lon-1, by virtue of its blood induction, and as a unique feature of the Borreliae, may be important in host adaptation from the arthropod to a warm-blooded host

Calculation of the optical transfer function of a light valve system with dark field observation

In a single light valve system, MTF curves and light efficiencies are calculated, which are only caused by the dark field method. Extended light sources in a regular arrangement with continuous spectral density in each of the three color channels-red, green, and blue-of the TV color projector are taken into account. Continuously tuned sinus modulation of the carrier gratings written into the control layer, acting as phase objects for the transmitted light, is chosen for the calculations. The results obtained are in good agreement with measurements

Design of a silica based AWG for visible light (lambda=670nm) applications

The suitability of silica based planar lightwave circuits, most commonly used for passive optical components in the telecom wavelength region 1.3¥ìm to 1.6¥ìm, is evaluated here for shorter wavelengths into the VIS range. Wavelength dependent scattering losses and minimum bending radii for different index differences .n are investigated. Exemplarily, a six channel AWG design around 670nm wavelength is presented

Arrayed waveguide gratings

Without abstrac

Two-dimensional arrays of diffractive microlenses for optical interconnects

Arrays of 16*16 diffractive optical microlenses are presented that are used in free space interconnection networks of electronic switching stages. They have been fabricated as 'binary optical elements' in glass substrates by microstructuring techniques. Individual elements have a diameter of 2 mm and 200 mu m and 16 levels per zone. Arrays with different F-number lenses for the two wavelengths 1.52 mu m and 0.63 mu m have been fabricated. In order to reduce reflection losses and cross talk in an interconnection network the lens arrays have been AR-coated with a two layer system of TiO2 and SiO2. The measured diffraction efficiency of the lenses with large F-numbers is 95%

Blazed Fresnel zone lenses approximated by discrete step profiles: Effects of fabrication errors

Blazed Fresnel zone lenses for 1.5 mu m wavelength were fabricated in quartz glass by means of microstructuring technology. The blazed profile in each zone of the lenses was approximated by two, four, and eight discrete levels. The effects of fabrication errors, such as depth and alignment errors, on the diffraction efficiency of the different Fresnel zone lenses were investigated. Further the location and intensity of the parasitic foci appearing due to the discrete level approximation are calculated. Theoretical results along with experimental measurements are presented

Arrayed waveguide gratings

Without abstrac

Arrayed-waveguide grating demultiplexer with variable transmission characteristic

A programmable arrayed-waveguide grating demultiplexer is presented. The device shows new functionalities, like a tunable center frequency and a variable transmission characteristic. The measured crosstalk was lower than -30 dB