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Frequentist nonparametric goodness-of-fit tests via marginal likelihood ratios
Hart, J.D.,Choi, T.,Yi, S. North-Holland Pub. Co ; Elsevier Science Ltd 2016 Computational statistics & data analysis Vol.96 No.-
<P>A nonparametric procedure for testing the goodness of fit of a parametric density is investigated. The test statistic is the ratio of two marginal likelihoods corresponding to a kernel estimate and the parametric model. The marginal likelihood for the kernel estimate is obtained by proposing a prior for the estimate's bandwidth, and then integrating the product of this prior and a leave-one-out kernel likelihood. Properties of the kernel-based marginal likelihood depend importantly on the kernel used. In particular, a specific, somewhat heavy-tailed, kernel K-0 yields better performing marginal likelihood ratios than does the popular Gaussian kernel. Monte Carlo is used to compare the power of the new test with that of the Shapiro-Wilk test, the Kolmogorov Smirnov test, and a recently proposed goodness-of-fit test based on empirical likelihood ratios. Properties of these tests are considered when testing the fit of normal and double exponential distributions. The new test is used to establish a claim made in the astronomy literature concerning the distribution of nebulae brightnesses in the Andromeda galaxy. Generalizations to the multivariate case are also described. (C) 2015 Elsevier B.V. All rights reserved.</P>
PHYSIOLOGY OF DIGESTION OF UREA-TREATED RICE STRAW IN SWAMP BUFFALO
Hart, F.J.,Wanapat, M. Asian Australasian Association of Animal Productio 1992 Animal Bioscience Vol.5 No.4
Four rumen-fistulated swamp buffaloes steers were used in a change-over experiment. This experiment was designed to provide a comparison of the effect of urea-ammonia treatment of rice straw with untreated rice straw. Nitrogen, mineral and trace elements were supplied at adequate levels to both diets in order to overcome deficiencies which may have otherwise confounded a direct comparison. There was a 46% increase in the intake of digestible organic matter (OM) with the urea-ammonia treated diet. This was contributed by a 17% increase in the digestibility of OM and a 25% increase in the voluntary intake of OM. Of the cell wall fraction, the digestibility of hemicellulose increased by the greatest amount (26%). There was an increased rate of passage of particulate matter out of the rumen for the treated straw, along with the increased rate of OM fermentation resulted in a 9% decrease in the amount of digesta dry matter (DM) contained in the rumen. The volatile fatty acid (VFA) pool in the rumen was 24% higher for the treated diet.
Biocompatible, smooth, plasma-treated nickel-titanium surface--an adequate platform for cell growth.
Chrzanowski, W,Szade, J,Hart, A D,Knowles, J C,Dalby, M J Technomic Pub 2012 Journal of biomaterials applications Vol.26 No.6
<P>High nickel content is believed to reduce the number of biomedical applications of nickel-titanium alloy due to the reported toxicity of nickel. The reduction in nickel release and minimized exposure of the cell to nickel can optimize the biocompatibility of the alloy and increase its use in the application where its shape memory effects and pseudoelasticity are particularly useful, e.g., spinal implants. Many treatments have been tried to improve the biocompatibility of Ni-Ti, and results suggest that a native, smooth surface could provide sufficient tolerance, biologically. We hypothesized that the native surface of nickel-titanium supports cell differentiation and insures good biocompatibility. Three types of surface modifications were investigated: thermal oxidation, alkali treatment, and plasma sputtering, and compared with smooth, ground surface. Thermal oxidation caused a drop in surface nickel content, while negligible chemistry changes were observed for plasma-modified samples when compared with control ground samples. In contrast, alkali treatment caused significant increase in surface nickel concentration and accelerated nickel release. Nickel release was also accelerated in thermally oxidized samples at 600 C, while in other samples it remained at low level. Both thermal oxidation and alkali treatment increased the roughness of the surface, but mean roughness R(a) was significantly greater for the alkali-treated ones. Ground and plasma-modified samples had 'smooth' surfaces with R(a)=4 nm. Deformability tests showed that the adhesion of the surface layers on samples oxidized at 600 C and alkali treatment samples was not sufficient; the layer delaminated upon deformation. It was observed that the cell cytoskeletons on the samples with a high nickel content or release were less developed, suggesting some negative effects of nickel on cell growth. These effects were observed primarily during initial cell contact with the surface. The most favorable cell responses were observed for ground and plasma-sputtered surfaces. These studies indicated that smooth, plasma-modified surfaces provide sufficient properties for cells to grow.</P>
Liu Jesse J,O’Neill Brannan E,Mazur-Hart David,Uluc Kutluay,Dogan Aclan,Cetas Justin S 대한뇌혈관외과학회 2022 Journal of Cerebrovascular and Endovascular Neuros Vol.24 No.3
Vascular compression of neural tissue causing neurological symptoms is a wellknown phenomenon. This is commonly seen in trigeminal neuralgia and, less commonly, in hemifacial spasm by small arteries, which can be treated by microvascular decompression. Rarely, larger arteries, such as the vertebral arteries, may compress the brainstem. This can lead to symptoms of pontine or medullary distress like hemiparesis, dysphagia, or respiratory distress. This is treated by macrovascular decompression. Due to the rare and heterogenous nature of this disease, there is no standardized approach. We describe a novel technique whereby the vertebrobasilar system is mobilized anterolaterally towards the occipital condyle with a sling to decompress the brainstem.<br/>We report two cases of vertebrobasilar dolichoectasia causing brainstem compression. A carotid patch graft sling with anterolateral mobilization to the occipital condyle is described as a surgical nuance to macrovascular decompressive surgery. Briefly, the vertebral artery was identified and dissected away from the brainstem and the bulbar cranial nerves. Bovine pericardium graft was used to create a sling around the artery by suturing the two ends together. The sling was then fixed either to the occipital condyle using cranial plating screws or suturing to the dura of the occipital condyle.<br/>A novel surgical technique for management of vertebrobasilar dolichoectasia causing brainstem compression with progressive neurological deterioration is reported. Anatomical location and the offending vessel should guide neurosurgeons to select the best surgical option to achieve complete decompression of the involved neural structures.
Comparative analysis of noise from three Falcon 9 launches
Mathews, Logan T.,Gee, Kent L.,Hart, Grant W.,Rasband, Reese D.,Novakovich, Daniel J.,Irarrazabal, Francisco I.,Vaughn, Aaron B.,Nelson, Pauline The Acoustical Society of Korea 2020 韓國音響學會誌 Vol.39 No.4
This study investigates the far-field noise from three Falcon 9 vehicle launches from Vandenberg Air Force Base, CA, USA, as measured from the same location within the nearby community of Lompoc. The overall sound pressure levels for the three launches are shown to be similar, but some differences in the early launch period are thought to be weather-related. The peak directivity angle in overall level is approximately 65 deg, which is consistent with horizontally-fired, static rocket data. For the third launch, waveforms and spectra are analyzed for different events during the launch sequence. The measured spectral bandwidth decreases with time, but spectral levels remain above the ambient noise throughout the main-engine firing. Additionally, late-launch phenomena observed in the data appear to be correlated with main-engine cutoff and second-stage engine start.
Sebastian Decker,Renaud Lafage,Christian Krettek,Robert Hart,Christopher Ames,Justin S. Smith,Douglas Burton,Eric Klineberg,Shay Bess,Frank J. Schwab,Virginie Lafage,International Spine Study Group 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.2
Study Design: Retrospective cohort study. Purpose: To investigate the role of sacral extension (SE) for the development of proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery. Overview of Literature: The development of PJK is multifactorial and different risk factors have been identified. Of these, there is some evidence that SE also affects the development of PJK, but data are insufficient. Methods: Using a combined database comprising two propensity-matched groups of fusions following ASD surgery, one with fixation to S1 or S1 and the ilium (SE) and one without SE but with a lower instrumented vertebra of L5 or higher (lumbar fixation, LF), PJK and the role of further parameters were analyzed. The propensity-matched variables included age, the upper-most instrumented vertebra (UIV), preoperative sagittal alignment, and the baseline to 1 year change of the sagittal alignment. Results: Propensity matching led to two groups of 89 patients each. The UIV, pelvic incidence minus lumbar lordosis, sagittal vertical axis, pelvic tilt, age, and body mass index were similar in both groups (p>0.05). The incidence of PJK at postoperative 1 year was similar for SE (30.3%) and LF (22.5%) groups (p=0.207). The PJK angle was comparable (p=0.963) with a change of −8.2° (SE) and −8.3° (LF) from the preoperative measures (p=0.954). A higher rate of PJK after SE (p=0.026) was found only in the subgroup of patients with UIV levels between T9 and T12. Conclusions: Instrumentation to the sacrum with or without iliac extension did not increase the overall risk of PJK. However, an increased risk for PJK was found after SE with UIV levels between T9 and T12.