226 research outputs found

    Radial and circumferential flow surveys at the inlet and exit of the Space Shuttle Main Engine High Pressure Fuel Turbine Model

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    The main objective of this test was to obtain detailed radial and circumferential flow surveys at the inlet and exit of the SSME High Pressure Fuel Turbine model using three-hole cobra probes, hot-film probes, and a laser velocimeter. The test was designed to meet several objectives. First, the techniques for making laser velocimeter, hot-film probe, and cobra probe measurements in turbine flows were developed and demonstrated. The ability to use the cobra probes to obtain static pressure and, therefore, velocity had to be verified; insertion techniques had to be established for the fragile hot-film probes; and a seeding method had to be established for the laser velocimetry. Once the measurement techniques were established, turbine inlet and exit velocity profiles, temperature profiles, pressure profiles, turbulence intensities, and boundary layer thicknesses were measured at the turbine design point. The blockage effect due to the model inlet and exit total pressure and total temperature rakes on the turbine performance was also studied. A small range of off-design points were run to obtain the profiles and to verify the rake blockage effects off-design. Finally, a range of different Reynolds numbers were run to study the effect of Reynolds number on the various measurements

    Next Step Toward Widespread Residential Deep Energy Retrofits

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    The complexity of deep energy retrofits warrants additional training to successfully manage multiple improvements that will change whole house air, heat, and moisture flow dynamics. The home performance contracting industry has responded to these challenges by aggregating skilled labor for assessment of and implementation under one umbrella. Two emerging business models are profiled that seek to resolve many of the challenges, weaknesses, opportunities, and threats described for the conventional business models

    Effect of pre-cardiac and adult stages of Dirofilaria immitis in pulmonary disease of cats: CBC, bronchial lavage cytology, serology, radiographs, CT images, bronchial reactivity, and histopathology

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    AbstractA controlled, blind study was conducted to define the initial inflammatory response and lung damage associated with the death of precardiac stages of Dirofilaria immitis in cats as compared to adult heartworm infections and normal cats. Three groups of six cats each were used: UU: uninfected untreated controls; PreS I: infected with 100 D. immitis L3 by subcutaneous injection and treated topically with selamectin 32 and 2 days pre-infection and once monthly for 8 months); IU: infected with 100 D. immitis L3 and left untreated. Peripheral blood, serum, bronchial lavage, and thoracic radiographic images were collected from all cats on Days 0, 70, 110, 168, and 240. CT images were acquired on Days 0, 110, and 240. Cats were euthanized, and necropsies were conducted on Day 240 to determine the presence of heartworms. Bronchial rings were collected for in vitro reactivity. Lung, heart, brain, kidney, and liver tissues were collected for histopathology. Results were compared for changes within each group. Pearson and Spearman correlations were performed for association between histologic, radiographic, serologic, hematologic and bronchoalveolar lavage (BAL) results. Infected cats treated with selamectin did not develop radiographically evident changes throughout the study, were heartworm antibody negative, and were free of adult heartworms and worm fragments at necropsy. Histologic lung scores and CT analysis were not significantly different between PreS I cats and UU controls. Subtle alveolar myofibrosis was noted in isolated areas of several PreS I cats and an eosinophilic BAL cytology was noted on Days 75 and 120. Bronchial ring reactivity was blunted in IU cats but was normal in PreS I and UU cats. The IU cats became antibody positive, and five cats developed adult heartworms. All cats with heartworms were antigen positive at one time point; but one cat was antibody positive, antigen negative, with viable adult females at necropsy. The CT revealed early involvement of all pulmonary arteries and a random pattern of parenchymal disease with severe lesions immediately adjacent to normal areas. Analysis of CT 3D reconstruction and Hounsfield units demonstrated lung disease consistent with restrictive pulmonary fibrosis with an interstitial infiltrate, absence of air trapping, and decrease in total lung volume in Group IU as compared to Groups UU and PreS I. The clinical implications of this study are that cats pretreated with selamectin 1 month before D. immitis L3 infection did not become serologically positive and did not develop pulmonary arterial hypertrophy and myofibrosis

    The paediatric flat foot and general anthropometry in 140 Australian school children aged 7 - 10 years

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    <p>Abstract</p> <p>Background</p> <p>Many studies have found a positive relationship between increased body weight and flat foot posture in children.</p> <p>Methods</p> <p>From a study population of 140 children aged seven to 10 years, a sample of 31 children with flat feet was identified by screening with the FPI-6. Basic anthropometric measures were compared between subjects with and without flat feet as designated.</p> <p>Results</p> <p>The results of this study, in contrast to many others, question the association of flat feet and heavy children. A significant relationship between foot posture and weight (FPI (L) r = -0.186 (p < 0.05), FPI(R) r = -0.194 (p < 0.05), waist girth (FPI (L) r = -0.213 (p < 0.05), FPI(R) r = -0.228 (p < 0.01) and BMI (FPI (L) r = -0.243 (p < 0.01), FPI(R) r = -0.263 (p < 0.01) was identified, but was both weak and inverse.</p> <p>Conclusions</p> <p>This study presents results which conflict with those of many previous investigations addressing the relationship between children's weight and foot posture. In contrast to previous studies, the implication of these results is that heavy children have less flat feet. Further investigation is warranted using a standardized approach to assessment and a larger sample of children to test this apparent contradiction.</p

    Plasticity in D1-Like Receptor Expression Is Associated with Different Components of Cognitive Processes

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    Dopamine D1-like receptors consist of D1 (D1A) and D5 (D1B) receptors and play a key role in working memory. However, their possibly differential contribution to working memory is unclear. We combined a working memory training protocol with a stepwise increase of cognitive subcomponents and real-time RT-PCR analysis of dopamine receptor expression in pigeons to identify molecular changes that accompany training of isolated cognitive subfunctions. In birds, the D1-like receptor family is extended and consists of the D1A, D1B, and D1D receptors. Our data show that D1B receptor plasticity follows a training that includes active mental maintenance of information, whereas D1A and D1D receptor plasticity in addition accompanies learning of stimulus-response associations. Plasticity of D1-like receptors plays no role for processes like response selection and stimulus discrimination. None of the tasks altered D2 receptor expression. Our study shows that different cognitive components of working memory training have distinguishable effects on D1-like receptor expression

    The real risks of steroid injection for plantar fasciitis, with a review of conservative therapies

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    This article presents a review of conservative therapies for plantar fasciitis pain reduction with a discussion of steroid therapy risks. The therapies reviewed include orthoses, stretching, extracorporeal shockwave, BTX-A, and corticosteroid injection/iontophoresis. These modes were included based on the availability of double blinded randomized controlled trials. We noted the following findings. Orthoses, regardless of type, can improve pain levels. Plantar stretching shows limited short-term benefit (1 month), but can reflect significant long-term improvement (10 months). Extracorporeal shockwave therapy shows equivocal benefit with some studies showing significant improvement and others showing none. Although BTX-A injections were the least studied, significant pain improvement was demonstrated in the short and long term. Steroid injection/iontophoresis showed significant improvement in the short term (1 month). Steroid therapy, when coupled with plantar stretching, can provide efficacious pain relief; however, steroid injections should be combined with ultrasound monitoring to reduce complications

    Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet

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    Osteoporosis and low bone mineral density affect millions of Americans. The majority of adults in North America have insufficient intake of vitamin D and calcium along with inadequate exercise. Physicians are aware that vitamin D, calcium and exercise are essential for maintenance of bone health. Physicians are less likely to be aware that dietary insufficiencies of magnesium, silicon, Vitamin K, and boron are also widely prevalent, and each of these essential nutrients is an important contributor to bone health. In addition, specific nutritional factors may improve calcium metabolism and bone formation. It is the authors’ opinion that nutritional supplements should attempt to provide ample, but not excessive, amounts of factors that are frequently insufficient in the typical American diet

    Severity dependent distribution of impairments in PSP and CBS: Interactive visualizations

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    BACKGROUND: Progressive supranuclear palsy (PSP) -Richardson's Syndrome and Corticobasal Syndrome (CBS) are the two classic clinical syndromes associated with underlying four repeat (4R) tau pathology. The PSP Rating Scale is a commonly used assessment in PSP clinical trials; there is an increasing interest in designing combined 4R tauopathy clinical trials involving both CBS and PSP. OBJECTIVES: To determine contributions of each domain of the PSP Rating Scale to overall severity and characterize the probable sequence of clinical progression of PSP as compared to CBS. METHODS: Multicenter clinical trial and natural history study data were analyzed from 545 patients with PSP and 49 with CBS. Proportional odds models were applied to model normalized cross-sectional PSP Rating Scale, estimating the probability that a patient would experience impairment in each domain using the PSP Rating Scale total score as the index of overall disease severity. RESULTS: The earliest symptom domain to demonstrate impairment in PSP patients was most likely to be Ocular Motor, followed jointly by Gait/Midline and Daily Activities, then Limb Motor and Mentation, and finally Bulbar. For CBS, Limb Motor manifested first and ocular showed less probability of impairment throughout the disease spectrum. An online tool to visualize predicted disease progression was developed to predict relative disability on each subscale per overall disease severity. CONCLUSION: The PSP Rating Scale captures disease severity in both PSP and CBS. Modelling how domains change in relation to one other at varying disease severities may facilitate detection of therapeutic effects in future clinical trials
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