606 research outputs found

    A STUDY OF THE ESTABLISHMENT AND OPERATION OF AN ADULT DAY CARE CENTER IN SOUTHSIDE VIRGINIA

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    Adult Day Cares are a viable option for many Americans with elderly parents. Whether both partner work full-time and are unable to care for their parents, or their parents need the socialization that a group setting would provide, many view these centers as a practical option for them. An Adult Day Care is the mediator between the strict supervision that a hospital setting would provide and the lack of supervision while the adult is at their home. This study examines the history of Adult Day Care Centers, the Adult Day Care options in Southside Virginia, and develops a thorough plan for a successful operation of an adult day care in Virginia

    Patents and Business Models for Software Firms

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    We analyze the relation between patents and the different business models available to firms in the software industry. The paper builds on Cusumano\u27s work defining the differences among firms that sell products, those that provide services, and the hybrid firms that fall between those polar categories. Combining data from five years of Software Magazine\u27s Software 500 with data about the patenting practices of those software firms, we analyze the relation between the share of revenues derived from product sales and the firm\u27s patenting practices. Accounting for size, R&D intensity, and sector-specific effects, the paper finds a robust positive correlation between product-based business models and patenting rates. We also present in this draft preliminary results suggesting that there is no significant relation between patenting practices and the extent to which the firm\u27s revenues are derived from software products and services, as opposed to hardware or other lines of business

    Biodegradable Wound Dressing for Skin Regeneration

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    Using the delayed healing model of diabetic (db/db) mice, we evaluated the ability of a novel silk based dressing to facilitate healing of full-thickness excisional wounds. Silk protein from Bombyx mori was used to create wound dressings via a proprietary electrospinning technique. The resulting dressing is vapor and air transmissible. Eight millimeter diameter full-thickness wounds were created on the backs of diabetic mice and covered with either a standard (n=12) telfa-gauze or the silk (n=12) dressing. At 2 day intervals, the telfa dressings were removed, the wounds photographed, measured and fresh dressings placed. For mice receiving the silk dressing, it was allowed to remain in place unless it became dislodged. In that case, a fresh dressing was placed into the wound bed. Wound healing was followed for 21 days at which time the mice were sacrificed, the wound areas excised and subjected to H & E and Trichrome staining. Wounds covered with the silk dressings developed an eschar encompassing the silk whereas wounds dressed with gauze remained moist and without eschar throughout the study period. Upon histologic examination, 1 of the gauze dressed wounds developed a complete epithelial layer across the wound. The remaining 11 wounds had large areas remaining without an epithelial cover. In contrast, 5 of 12 mice receiving the silk dressing developed complete epithelial layers, 2 additional mice had very small areas remaining without a complete epithelium. The remaining 5 had modest areas without an epithelial covering. The ability of silk dressings to permit the formation of an eschar versus gauze in which the wounds remained wet may contribute significantly to the healing response observed. These results suggest that the breathable, vapor transmissible nature of the silk dressing may be an effective dressing for difficult to heal wounds such as diabetic foot ulcers

    Preliminary SP-100/Stirling heat exchanger designs

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    Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems

    Preliminary Design of a SP-100/Stirling Radiatively Coupled Heat Exchanger

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    Several methods for coupling the SP-100 space nuclear reactor to the NASA Lewis Research Center's Free Piston Stirling Power Convertor (FPSPC) are presented. A 25 kWe, dual opposed Stirling convertor configuration is used in these designs. The concepts use radiative coupling between the SP-100 lithium loop and the sodium heat pipe of the Stirling convertor to transfer the heat from the reactor to the convertor. Four separate configurations are presented. Masses for the four designs vary from 41 to 176 kgs. Each design's structure, heat transfer characteristics, and heat pipe performance are analytically modeled

    Longitudinal patterns of antidepressant prescribing in primary care in the UK: comparison with treatment guidelines

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    The objective of this study was to determine whether patients beginning therapy on the most common tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) differed in their likelihood of having antidepressant treatment that was consistent with recommended treatment guidelines in the UK. An analytical file constructed from a large general practitioner medical records database (DIN-LINK) from the UK for the years 1992-97 was constructed. A total of 16 204 patients with a new episode of antidepressant therapy who initiated therapy on one of the most often prescribed TCAs (amitriptyline, dothiepin, imipramine and lofepramine) or SSRIs (fluoxetine, paroxetine and sertraline) were analysed. A dichotomous measure was defined to indicate whether subjects were prescribed at least 120 days of antidepressant therapy at an adequate average daily dose within the first 6 months after initiation of therapy. Only 6.0% of patients initiating therapy on aTCA and 32.9% of patients initiating therapy on a SSRI were prescribed antidepressant treatment that was consistent with treatment guidelines. After controlling for observable characteristics, patients who initiated therapy on a SSRI were much more likely (odds ratio=7.473, p<0.001) to have a prescribed average daily dose and duration consistent with recommended treatment guidelines within the first 6 months of initiating therapy than were patients who initiated therapy on a TCA. These findings suggest that initial antidepressant selection is an important determinant of whether the subsequent course of treatment is consistent with current national guidelines for the treatment of depression in the UK.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68732/2/10.1177_026988119901300204.pd

    Multicenter Clinical Evaluation of the Automated Aries Bordetella Assay

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    Molecular methods offer superior sensitivity and specificity and reduce testing turnaround time from days to hours for detection of Bordetella pertussis and Bordetella parapertussis In this study, we evaluated the performance of the automated PCR-based Aries Bordetella Assay, which detects both B. pertussis and B. parapertussis directly from nasopharyngeal swab specimens. The limits of detection (LoDs) were 1,800 CFU·ml-1 for B. pertussis and 213 CFU·ml-1 for B. parapertussis The assay detected 16/18 unique B. pertussis/B. parapertussis strains. Of 71 potentially cross-reacting organisms, 5 generated false positives in 1/6 replicates; none of 6 additional Bordetella spp. were erroneously detected. Specimens were stable at 20 to 25°C for at least 10 h, at 4 to 8°C for 10 days, and at temperatures not exceeding -70°C for 6 months. Of 1,052 nasopharyngeal specimens from patients with suspected pertussis, 3.0% (n = 32) were B. pertussis positive and 0.2% (n = 2) were B. parapertussis positive. Combining these data with Aries Bordetella Assay data from 57 nasopharyngeal samples with previously confirmed B. pertussis or B. parapertussis data and with data from 50 contrived B. parapertussis samples, the proportions of positive and negative agreement of the respective Aries assays with the reference assays were 97.1% and 99.0% for B. pertussis and 100% and 99.7% for B. parapertussis The Aries Bordetella Assay provides accurate detection and distinction of B. pertussis and B. parapertussis infections within 2 h. (This study has been registered at ClinicalTrials.gov under registration no. NCT02862262.)

    Ecosystem fluxes of hydrogen: a comparison of flux-gradient methods

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    Our understanding of biosphere–atmosphere exchange has been considerably enhanced by eddy covariance measurements. However, there remain many trace gases, such as molecular hydrogen (H[subscript 2]), that lack suitable analytical methods to measure their fluxes by eddy covariance. In such cases, flux-gradient methods can be used to calculate ecosystem-scale fluxes from vertical concentration gradients. The budget of atmospheric H[subscript 2] is poorly constrained by the limited available observations, and thus the ability to quantify and characterize the sources and sinks of H[subscript 2] by flux-gradient methods in various ecosystems is important. We developed an approach to make nonintrusive, automated measurements of ecosystem-scale H2 fluxes both above and below the forest canopy at the Harvard Forest in Petersham, Massachusetts, for over a year. We used three flux-gradient methods to calculate the fluxes: two similarity methods that do not rely on a micrometeorological determination of the eddy diffusivity, K, based on (1) trace gases or (2) sensible heat, and one flux-gradient method that (3) parameterizes K. We quantitatively assessed the flux-gradient methods using CO[subscript 2] and H[subscript 2]O by comparison to their simultaneous independent flux measurements via eddy covariance and soil chambers. All three flux-gradient methods performed well in certain locations, seasons, and times of day, and the best methods were trace gas similarity for above the canopy and K parameterization below it. Sensible heat similarity required several independent measurements, and the results were more variable, in part because those data were only available in the winter, when heat fluxes and temperature gradients were small and difficult to measure. Biases were often observed between flux-gradient methods and the independent flux measurements, and there was at least a 26% difference in nocturnal eddy-derived net ecosystem exchange (NEE) and chamber measurements. H[subscript 2] fluxes calculated in a summer period agreed within their uncertainty and pointed to soil uptake as the main driver of H[subscript 2] exchange at Harvard Forest, with H[subscript 2] deposition velocities ranging from 0.04 to 0.10 cm s[superscript −1].National Science Foundation (U.S.) (NSF Graduate Research Fellowship)United States. National Aeronautics and Space Administration (Advanced Global Atmospheric Gases Experiment (AGAGE))Massachusetts Institute of Technology. Joint Program on the Science & Policy of Global ChangeMartin Family Society of Fellows for SustainabilityMassachusetts Institute of Technology (Ally of Nature Research Fund)Massachusetts Institute of Technology (William Otis Crosby Lectureship)Massachusetts Institute of Technology (Warren Klein Fund

    Recent Applications of Higher-Order Spectral Analysis to Nonlinear Aeroelastic Phenomena

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    Recent applications of higher-order spectral (HOS) methods to nonlinear aeroelastic phenomena are presented. Applications include the analysis of data from a simulated nonlinear pitch and plunge apparatus and from F-18 flight flutter tests. A MATLAB model of the Texas A&MUniversity s Nonlinear Aeroelastic Testbed Apparatus (NATA) is used to generate aeroelastic transients at various conditions including limit cycle oscillations (LCO). The Gaussian or non-Gaussian nature of the transients is investigated, related to HOS methods, and used to identify levels of increasing nonlinear aeroelastic response. Royal Australian Air Force (RAAF) F/A-18 flight flutter test data is presented and analyzed. The data includes high-quality measurements of forced responses and LCO phenomena. Standard power spectral density (PSD) techniques and HOS methods are applied to the data and presented. The goal of this research is to develop methods that can identify the onset of nonlinear aeroelastic phenomena, such as LCO, during flutter testing
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