96 research outputs found

    Effectiveness of Case Management with Problem-Solving Therapy for Rural Older Adults with Depression

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    Objective To evaluate the effect of case management with problem solving therapy (CM-PST) on depression and disability among rural older adults and compare its effect with outcomes derived from a previous, but similar study among 84 urban older adults. Methods This study examined the comparative effectiveness of a CM-PST intervention for older adults with depression and unmet needs across rural and urban settings. Participants received 12 one-hour sessions of CM-PST with a master's-level clinician. A total of 56 rural and 84 urban adults aged 60 and older experiencing mild to moderate depression received services in their homes. Results The rural CM-PST intervention resulted in significantly reduced depression (reduction of 13.9 points, 95% CI 12.2 to 15.7, t(422)= 15.35, p<0.0001) and disability by week 12 (reduction of 6.7 points, 95% CI 4.8 to 8.5, t(425)= 7.01, p<0.0001). Reductions in depression and disability were sustained through week 24. The reductions in depression (F=3.98 df=4,388. p=0.0035) and disability (F=2.71, df=4,381, p=0.03) found in the rural sample were comparable to, or better than, those found in the urban sample. Improvements in unmet need and resilience predicted lower depression scores at 12 weeks, while improvements in unmet need and hopelessness predicted improvements in disability. No moderators of depression were identified, but baseline values of self-efficacy, resilience, and hopelessness moderated disability. Conclusions CM-PST was as effective at reducing depression and disability among rural older adults as it was for urban older adults. Home-delivered CM-PST can be successfully adapted to meet the specific needs of rural seniors using resources often available in rural communities.publishedVersio

    Effect of Polycaprolactone Scaffold Permeability on Bone Regeneration In Vivo

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    Successful bone tissue engineering depends on the scaffold's ability to allow nutrient diffusion to and waste removal from the regeneration site, as well as provide an appropriate mechanical environment. Since bone is highly vascularized, scaffolds that provide greater mass transport may support increased bone regeneration. Permeability encompasses the salient features of three-dimensional porous scaffold architecture effects on scaffold mass transport. We hypothesized that higher permeability scaffolds will enhance bone regeneration for a given cell seeding density. We manufactured poly---caprolactone scaffolds, designed to have the same internal pore design and either a low permeability (0.688-10-7m4/N-s) or a high permeability (3.991-10-7m4/N-s), respectively. Scaffolds were seeded with bone morphogenic protein-7-transduced human gingival fibroblasts and implanted subcutaneously in immune-compromised mice for 4 and 8 weeks. Micro-CT evaluation showed better bone penetration into high permeability scaffolds, with blood vessel infiltration visible at 4 weeks. Compression testing showed that scaffold design had more influence on elastic modulus than time point did and that bone tissue infiltration increased the mechanical properties of the high permeability scaffolds at 8 weeks. These results suggest that for polycaprolactone, a more permeable scaffold with regular architecture is best for in vivo bone regeneration. This finding is an important step toward the end goal of optimizing a scaffold for bone tissue engineering.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90462/1/ten-2Etea-2E2010-2E0560.pd

    Thermal Kinetic Inductance Detectors for millimeter-wave detection

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    Thermal Kinetic Inductance Detectors (TKIDs) combine the excellent noise performance of traditional bolometers with a radio frequency multiplexing architecture that enables the large detector counts needed for the next generation of millimeter-wave instruments. In this paper, we first discuss the expected noise sources in TKIDs and derive the limits where the phonon noise contribution dominates over the other detector noise terms: generation-recombination, amplifier, and two-level system (TLS) noise. Second, we characterize aluminum TKIDs in a dark environment. We present measurements of TKID resonators with quality factors of about 10510^5 at 80 mK. We also discuss the bolometer thermal conductance, heat capacity, and time constants. These were measured by the use of a resistor on the thermal island to excite the bolometers. These dark aluminum TKIDs demonstrate a noise equivalent power NEP = 2×1017W/Hz2 \times 10^{-17} \mathrm{W}/\mathrm{\sqrt{Hz}} , with a 1/f1/f knee at 0.1 Hz, which provides background noise limited performance for ground-based telescopes observing at 150 GHz.Comment: 15 pages, 12 figure

    MKID development for SuperSpec: an on-chip, mm-wave, filter-bank spectrometer

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    SuperSpec is an ultra-compact spectrometer-on-a-chip for millimeter and submillimeter wavelength astronomy. Its very small size, wide spectral bandwidth, and highly multiplexed readout will enable construction of powerful multibeam spectrometers for high-redshift observations. The spectrometer consists of a horn-coupled microstrip feedline, a bank of narrow-band superconducting resonator filters that provide spectral selectivity, and Kinetic Inductance Detectors (KIDs) that detect the power admitted by each filter resonator. The design is realized using thin-film lithographic structures on a silicon wafer. The mm-wave microstrip feedline and spectral filters of the first prototype are designed to operate in the band from 195-310 GHz and are fabricated from niobium with at Tc of 9.2K. The KIDs are designed to operate at hundreds of MHz and are fabricated from titanium nitride with a Tc of 2K. Radiation incident on the horn travels along the mm-wave microstrip, passes through the frequency-selective filter, and is finally absorbed by the corresponding KID where it causes a measurable shift in the resonant frequency. In this proceedings, we present the design of the KIDs employed in SuperSpec and the results of initial laboratory testing of a prototype device. We will also briefly describe the ongoing development of a demonstration instrument that will consist of two 500-channel, R=700 spectrometers, one operating in the 1-mm atmospheric window and the other covering the 650 and 850 micron bands.Comment: As submitted, except that "in prep" references have been update

    The cryomechanical design of MUSIC: a novel imaging instrument for millimeter-wave astrophysics at the Caltech Submillimeter Observatory

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    MUSIC (Multicolor Submillimeter kinetic Inductance Camera) is a new facility instrument for the Caltech Submillimeter Observatory (Mauna Kea, Hawaii) developed as a collaborative effect of Caltech, JPL, the University of Colorado at Boulder and UC Santa Barbara, and is due for initial commissioning in early 2011. MUSIC utilizes a new class of superconducting photon detectors known as microwave kinetic inductance detectors (MKIDs), an emergent technology that offers considerable advantages over current types of detectors for submillimeter and millimeter direct detection. MUSIC will operate a focal plane of 576 spatial pixels, where each pixel is a slot line antenna coupled to multiple detectors through on-chip, lumped-element filters, allowing simultaneously imaging in four bands at 0.86, 1.02, 1.33 and 2.00 mm. The MUSIC instrument is designed for closed-cycle operation, combining a pulse tube cooler with a two-stage Helium-3 adsorption refrigerator, providing a focal plane temperature of 0.25 K with intermediate temperature stages at approximately 50, 4 and 0.4 K for buffering heat loads and heat sinking of optical filters. Detector readout is achieved using semi-rigid coaxial cables from room temperature to the focal plane, with cryogenic HEMT amplifiers operating at 4 K. Several hundred detectors may be multiplexed in frequency space through one signal line and amplifier. This paper discusses the design of the instrument cryogenic hardware, including a number of features unique to the implementation of superconducting detectors. Predicted performance data for the instrument system will also be presented and discussed

    1.6:1 bandwidth two-layer antireflection structure for silicon matched to the 190–310  GHz atmospheric window

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    Although high-resistivity, low-loss silicon is an excellent material for terahertz transmission optics, its high refractive index necessitates an antireflection treatment. We fabricated a wide-bandwidth, two-layer antireflection treatment by cutting subwavelength structures into the silicon surface using multi-depth deep reactive-ion etching (DRIE). A wafer with this treatment on both sides has <−20  dB (<1%) reflectance over 187–317 GHz at a 15° angle of incidence in TE polarization. We also demonstrated that bonding wafers introduce no reflection features above the −20  dB level (also in TE at 15°), reproducing previous work. Together these developments immediately enable construction of wide-bandwidth silicon vacuum windows and represent two important steps toward gradient-index silicon optics with integral broadband antireflection treatment
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