720 research outputs found
Effects of Dynamic Properties of Rockfill Materials on Seismic Response of Concrete-Faced Rockfill Dams
In this paper, the equivalent-linear method is used for three-dimensional seismic response analyses of concrete-faced rockfill dams (CFRDs). Different combinations of various parameters such as small-strain shear modulus, strain-dependent patterns of modulus and hysteretic damping, are considered to systematically investigate the effects of dynamic properties of rockfill-type coarse-grained materials on seismic dynamic response of CFRDs. It is concluded that the nonlinearity of embankment material has a significant effect on both vibration characteristics and seismic response behavior of CFRDs. Numerical results presented are instructive to gain a better understanding on earthquake-resistant behavior of CFRDs and the effects of dynamic properties of rockfills
Management of Symptomatic Sacral Perineural Cysts
BACKGROUND: There has been no consensus on the optimal treatment of symptomatic sacral perineural cysts. Most previous reports concerning the management methods were either sporadic case reports or a series of limited cases. This study is to further optimize the management for patients with symptomatic sacral perineural cysts by analyzing the outcomes of a cohort of patients who were treated with different strategies. METHODS AND FINDINGS: We reviewed the outcomes of 15 patients with symptomatic sacral perineural cysts who were managed by three different modalities from 1998 through 2010. Six patients underwent microsurgical cyst fenestration and cyst wall imbrication. Seven patients underwent a modified surgical procedure, during which the cerebrospinal fluid leak aperture was located and repaired. Two patients were treated with medication and physical therapy. Outcomes of the patients were assessed by following up (13 months to 10 years). All of the six patients treated with microsurgical cyst fenestration and cyst wall imbrication experienced complete or substantial relief of their preoperative symptoms. However, the symptoms of one patient reappeared eight months after the operation. Another patient experienced a postoperative cerebrospinal fluid leakage. Six of the seven patients treated with the modified surgical operation experienced complete or substantial resolution of their preoperative symptoms, with only one patient who experienced temporary worsening of his preoperative urine incontinence, which disappeared gradually one month later. No new postoperative neurological deficits, no cerebrospinal fluid leaks and no recurrence were observed in the seven patients. The symptoms of the two patients treated with conservative measures aggravated with time. CONCLUSIONS: Microsurgical operation should be a treatment consideration in patients with symptomatic sacral perineural cysts. Furthermore, the surgical procedure with partial cyst removal and aperture repair for prevention of cerebrospinal fluid leakage seemed to be more simple and effective
Relightable Neural Assets
High-fidelity 3D assets with materials composed of fibers (including hair),
complex layered material shaders, or fine scattering geometry are ubiquitous in
high-end realistic rendering applications. Rendering such models is
computationally expensive due to heavy shaders and long scattering paths.
Moreover, implementing the shading and scattering models is non-trivial and has
to be done not only in the 3D content authoring software (which is necessarily
complex), but also in all downstream rendering solutions. For example, web and
mobile viewers for complex 3D assets are desirable, but frequently cannot
support the full shading complexity allowed by the authoring application. Our
goal is to design a neural representation for 3D assets with complex shading
that supports full relightability and full integration into existing renderers.
We provide an end-to-end shading solution at the first intersection of a ray
with the underlying geometry. All shading and scattering is precomputed and
included in the neural asset; no multiple scattering paths need to be traced,
and no complex shading models need to be implemented to render our assets,
beyond a single neural architecture. We combine an MLP decoder with a feature
grid. Shading consists of querying a feature vector, followed by an MLP
evaluation producing the final reflectance value. Our method provides
high-fidelity shading, close to the ground-truth Monte Carlo estimate even at
close-up views. We believe our neural assets could be used in practical
renderers, providing significant speed-ups and simplifying renderer
implementations
CCR: Facial Image Editing with Continuity, Consistency and Reversibility
Three problems exist in sequential facial image editing: incontinuous
editing, inconsistent editing, and irreversible editing. Incontinuous editing
is that the current editing can not retain the previously edited attributes.
Inconsistent editing is that swapping the attribute editing orders can not
yield the same results. Irreversible editing means that operating on a facial
image is irreversible, especially in sequential facial image editing. In this
work, we put forward three concepts and corresponding definitions: editing
continuity, consistency, and reversibility. Then, we propose a novel model to
achieve the goal of editing continuity, consistency, and reversibility. A
sufficient criterion is defined to determine whether a model is continuous,
consistent, and reversible. Extensive qualitative and quantitative experimental
results validate our proposed model and show that a continuous, consistent and
reversible editing model has a more flexible editing function while preserving
facial identity. Furthermore, we think that our proposed definitions and model
will have wide and promising applications in multimedia processing. Code and
data are available at https://github.com/mickoluan/CCR.Comment: 10 pages, 11 figure
The relationship between job performance and perceived organizational support in faculty members at Chinese universities: a questionnaire survey
BACKGROUND: Although several studies have been conducted to investigate the relationship between perceived organizational support (POS) and job performance (JP), it remains unclear whether this relationship is appropriate for faculty members at Chinese universities. The objectives of this study were to (a) examine the correlation between POS andJP; (b) identify the predictors of POS, including demographic and organizational characteristics among faculty members at a Chinese university; (c) investigate the influence of mediating factors between POS and JP; and (d) compare the findings of this study with related studies. METHODS: A cross-sectional questionnaire survey was used in this study. The questionnaire was administered to 700 faculty members who were randomly selected from all faculty members at six universities. A total of 581 questionnaires were obtained. A statistical model for JP was developed based on the literature review. RESULTS: The analysis results indicated that the relationship between POS and JP was mediated by job satisfaction (JS), positive affectivity (PA), and affective commitment (AC). In addition, procedural and distributive justice contribute to POS. CONCLUSIONS: The study concludes that the relationship between POS and JP is mediated by JS, PA, and AC and is influenced by POS. These results can provide evidence for university administrators to improve POS and increase the JP of faculty members at universities
A Novel Fused Optimization Algorithm of Genetic Algorithm and Ant Colony Optimization
A novel fused algorithm that delivers the benefits of both genetic algorithms (GAs) and ant colony optimization (ACO) is proposed to solve the supplier selection problem. The proposed method combines the evolutionary effect of GAs and the cooperative effect of ACO. A GA with a great global converging rate aims to produce an initial optimum for allocating initial pheromones of ACO. An ACO with great parallelism and effective feedback is then served to obtain the optimal solution. In this paper, the approach has been applied to the supplier selection problem. By conducting a numerical experiment, parameters of ACO are optimized using a traditional method and another hybrid algorithm of a GA and ACO, and the results of the supplier selection problem demonstrate the quality and efficiency improvement of the novel fused method with optimal parameters, verifying its feasibility and effectiveness. Adopting a fused algorithm of a GA and ACO to solve the supplier selection problem is an innovative solution that presents a clear methodological contribution to optimization algorithm research and can serve as a practical approach and management reference for various companies
Value of reduced glomerular filtration rate assessment with cardiometabolic index: insights from a population-based Chinese cohort
Abstract
Background
Recent studies have suggested that cardiometabolic index (CMI), a novel estimate of visceral adipose tissue, could be of use in the evaluation of cardiovascular risk factors. However, the potential utility and clinical significance of CMI in the detection of reduced estimated glomerular filtration rate (eGFR) remains uncertain. The purpose of this study was to investigate the usefulness of CMI in assessing reduced eGFR in the general Chinese population.
Methods
This cross-sectional analysis included 11,578 participants (mean age: 53.8 years, 53.7% females) from Northeast China Rural Cardiovascular Health Study (NCRCHS) of general Chinese population (data collected from January 2013 to August 2013). CMI was calculated by triglyceride to high density lipoprotein cholesterol ratio multiply waist-to-height ratio. Reduced eGFR was defined as eGFR< 60 ml/min per 1.73m2. Multivariate regressions were performed to determine CMI’s association with eGFR value and eGFR reduction, ROC analyses were employed to investigate CMI’s discriminating ability for decreased eGFR.
Results
The prevalence of reduced eGFR was 1.7% in males and 2.5% in females. CMI was notably more adverse in reduced eGFR groups, regardless of genders. In fully adjusted multivariate linear models, each 1 SD increment of CMI caused 3.150 ml/min per 1.73m2 and 2.411 ml/min per 1.73m2 loss of eGFR before CMI reached 1.210 and 1.520 in males and females, respectively. In logistic regression analyses, per 1 SD increase of CMI brought 51.6% additional risk of reduced eGFR in males while caused 1.347 times of risk in females. After divided into quartiles, people in the top quartile of CMI had higher adjusted ORs of having reduced eGFR, with ORs of 4.227 (1.681, 10.627) and 3.442 (1.685–7.031) for males and females respectively. AUC of CMI was revealed to be 0.633 (0.620–0.646) in males and 0.684 (0.672–0.695) in females.
Conclusions
Higher CMI was independently associated with greater burden of reduced eGFR, highlighting VAT distribution and dysfunction as a potential mechanism underlying the association of obesity with kidney damage and adverse cardiovascular outcomes. The findings from this study provided important insights regarding the potential usefulness and clinical relevance of CMI in the detection of reduced eGFR among general Chinese population.https://deepblue.lib.umich.edu/bitstream/2027.42/146138/1/12882_2018_Article_1098.pd
In situ Raman quantitative monitoring of methanogenesis: Culture experiments of a deep-sea cold seep methanogenic archaeon
Gas production from several metabolic pathways is a necessary process that accompanies the growth and central metabolism of some microorganisms. However, accurate and rapid nondestructive detection of gas production is still challenging. To this end, gas chromatography (GC) is primarily used, which requires sampling and sample preparation. Furthermore, GC is expensive and difficult to operate. Several researchers working on microbial gases are looking forward to a new method to accurately capture the gas trends within a closed system in real-time. In this study, we developed a precise quantitative analysis for headspace gas in Hungate tubes using Raman spectroscopy. This method requires only a controlled focus on the gas portion inside Hungate tubes, enabling nondestructive, real-time, continuous monitoring without the need for sampling. The peak area ratio was selected to establish a calibration curve with nine different CH4–N2 gaseous mixtures and a linear relationship was observed between the peak area ratio of methane to nitrogen and their molar ratios (A(CH4)/A(N2) = 6.0739 × n(CH4)/n(N2)). The results of in situ quantitative analysis using Raman spectroscopy showed good agreement with those of GC in the continuous monitoring of culture experiments of a deep-sea cold seep methanogenic archaeon. This method significantly improves the detection efficiency and shows great potential for in situ quantitative gas detection in microbiology. It can be a powerful complementary tool to GC
Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma
Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelial–mesenchymal transition (EMT)–related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process
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