7,958 research outputs found
Singlet-triplet splittings in free and self-trapped excitons
We discuss the available experimental data for the singlet-triplet splitting of free and self-trapped excitons in alkali halides. These data are analysed quantitatively using the pseudopotential method of Bartram, Stoneham and Gash. The predictions confirm the trend emerging from the observed data, namely that the splittings are systematically lower for the self-trapped systems. This difference comes principally from the spread of the self-trapped hole onto two ions, and would not be expected, for example, if the hole were localised on a single site
A probability density function generator based on neural networks
© 2019 Elsevier B.V. In order to generate a probability density function (PDF) for fitting the probability distributions of practical data, this study proposes a deep learning method which consists of two stages: (1) a training stage for estimating the cumulative distribution function (CDF) and (2) a performing stage for predicting the corresponding PDF. The CDFs of common probability distributions can be utilised as activation functions in the hidden layers of the proposed deep learning model for learning actual cumulative probabilities, and the differential equation of the trained deep learning model can be used to estimate the PDF. Numerical experiments with single and mixed distributions are conducted to evaluate the performance of the proposed method. The experimental results show that the values of both CDF and PDF can be precisely estimated by the proposed method
Comparison of fatty-acid-binding protein 4 and adiponectin levels in infrapatellar fat pad and subcutaneous adipose tissue, synovial fluid and plasma in subjects with knee osteoarthritis
Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 2 - Basic Science/General Orthopaedics: no. 2.8Introduction: It was recently reported that inflammation is involved in the pathogenesis of osteoarthritis (OA). Fattyacid-binding
protein 4 (FABP4) and adiponectin are both adipocyte-derived cytokines closely related with inflammation
pathways. The FABP4 exhibits a pro-inflammatory property while adiponectin shows anti-inflammatory effect. The study
aimed to assess the expression of FABP4 and adiponectin in paired blood and synovial fluid from OA patients, and to
examine whether the infrapatellar fat pad (IPFP) from OA subjects would release FABP4 and adiponectin similar to that of
donor-matched subcutaneous adipose tissue (ScAT).
Materials and Methods: Plasma, synovial fluid, ScAT, and IPFP of 20 OA patients (4 males and 16 females) were collected
during total knee arthroplasty. Levels of FABP4 and adiponectin were measured in plasma, synovial fluid, and fat
conditioned media using ELISA (AIS, HKU).
Results: Levels of FABP4 were significantly higher in IPFP media than ScAT (p = 0.015), while the same were significantly
higher in synovial fluid than in plasma (p < 0.001). There were no significant differences of adiponectin levels between
IPFP and ScAT media (p = 0.737). Plasma levels of adiponectin were significantly higher than synovial fluid (p < 0.001).
Discussion and Conclusion: The OA patients exhibit an inflammatory state in local environment (IPFP and synovial fluid)
compared with systemic environment (ScAT and plasma). The IPFP may play a key role in OA inflammation and may be
an important resource of inflammatory mediators in synovial fluid.postprin
Presumed pseudokinase VRK3 functions as a BAF kinase
Vaccinia-related kinase 3 (VRK3) is known as a pseudokinase that is catalytically inactive due to changes in motifs that are essential for kinase activity. Although VRK3 has been regarded as a genuine pseudokinase from structural and biochemical studies, recent reports suggest that VRK3 acts as an active kinase as well as a signaling scaffold in cells. Here, we demonstrate that VRK3 phosphorylates the nuclear envelope protein barrier-to-autointegration factor (BAF) on Ser4. Interestingly, VRK3 kinase activity is dependent upon its N-terminal regulatory region, which is excluded from the determination of its crystal structure. Furthermore, the kinase activity of VRK3 is involved in the regulation of the cell cycle. VRK3 expression levels increase during interphase, whereas VRK1 is enriched in late G2 and early M phase. Ectopic expression of VRK3 induces the translocation of BAF from the nucleus to the cytoplasm. In addition, depletion of VRK3 decreases the population of proliferating cells. These data suggest that VRK3-mediated phosphorylation of BAF may facilitate DNA replication or gene expression by facilitating the dissociation of nuclear envelope proteins and chromatin during interphase. (C) 2015 Elsevier B.V. All rights reserved.1174Ysciescopu
Impact of different factors on the risk perceptions of employees in container shipping companies: a case study of Taiwan
This paper attempts to investigate the impact of several factors on the risk perception of the employees in container shipping companies. The investigation is conducted through an empirical study using Analysis of Variance (ANOVA) based on the Taiwan container shipping companies as a case study. The data were collected through a questionnaire survey in which the respondents were required to indicate their details (e.g. work experience, position, and department, etc.) and perceived risk factors in relation to container shipping logistics operations.
The study reveals that work experience has a significant impact on the perception of risks in aspects of financial loss and safety and security incident related loss. It is notable that the respondents whose work experience is less than 10 years have a significantly higher perception of risks than the others. The study also shows that the size of company impacts on risk perceptions in respect of financial loss and safety and security incident related loss. In addition, employeesâ position and their company type do not affect respondentsâ risk perception
Quantum-secure message authentication via blind-unforgeability
Formulating and designing unforgeable authentication of classical messages in
the presence of quantum adversaries has been a challenge, as the familiar
classical notions of unforgeability do not directly translate into meaningful
notions in the quantum setting. A particular difficulty is how to fairly
capture the notion of "predicting an unqueried value" when the adversary can
query in quantum superposition. In this work, we uncover serious shortcomings
in existing approaches, and propose a new definition. We then support its
viability by a number of constructions and characterizations. Specifically, we
demonstrate a function which is secure according to the existing definition by
Boneh and Zhandry, but is clearly vulnerable to a quantum forgery attack,
whereby a query supported only on inputs that start with 0 divulges the value
of the function on an input that starts with 1. We then propose a new
definition, which we call "blind-unforgeability" (or BU.) This notion matches
"intuitive unpredictability" in all examples studied thus far. It defines a
function to be predictable if there exists an adversary which can use
"partially blinded" oracle access to predict values in the blinded region. Our
definition (BU) coincides with standard unpredictability (EUF-CMA) in the
classical-query setting. We show that quantum-secure pseudorandom functions are
BU-secure MACs. In addition, we show that BU satisfies a composition property
(Hash-and-MAC) using "Bernoulli-preserving" hash functions, a new notion which
may be of independent interest. Finally, we show that BU is amenable to
security reductions by giving a precise bound on the extent to which quantum
algorithms can deviate from their usual behavior due to the blinding in the BU
security experiment.Comment: 23+9 pages, v3: published version, with one theorem statement in the
summary of results correcte
Risk analysis for container shipping: from a logistics perspective
Purpose â The purpose of this paper is to explore and analyse the risks in container shipping operations from a logistics perspective. In the paper, risks associated with the three flows in logistics â information, physical, and payment flow are identified and analysed.
Design/methodology/approach â The use of case study method was first explained and justified. Second, risk identification was started with supporting references, several interviews were then conducted to identify and validate the potential risks in container shipping operations. A questionnaire was deployed to collect related data; and the impacts of the risks were then assessed and ranked using the method of risk mapping.
Findings â The paper has identified a total of 35 risk factors and classified them into different categories. The paper has also revealed that the risks associated with physical flows have more serious risk impacts than the other types of risks; however, one of the risk factors associated with information flow (shippers hiding cargo information) is the most significant one among all the factors.
Originality/value â Although many studies have been conducted on container shipping operational risks, no studies so far have approached this issue from a perspective that inclusively examines all the possible risks and comprehensively evaluates the relative importance of each of them. This study has identified the risks in container shipping operations, and analysed and ranked the level of these risks. The research further ârefinesâ the findings of some previous studies by placing the risk factors addressed therein in a full ârisk pictureâ which was developed systematically
Evidence for Two Modes of Synergistic Induction of Apoptosis by Mapatumumab and Oxaliplatin in Combination with Hyperthermia in Human Colon Cancer Cells
Colorectal cancer is the third leading cause of cancer-related mortality in the world-- the main cause of death from colorectal cancer is hepatic metastases, which can be treated with isolated hepatic perfusion (IHP). Searching for the most clinically relevant approaches for treating colorectal metastatic disease by isolated hepatic perfusion (IHP), we developed the application of oxaliplatin concomitantly with hyperthermia and humanized death receptor 4 (DR4) antibody mapatumumab (Mapa), and investigated the molecular mechanisms of this multimodality treatment in human colon cancer cell lines CX-1 and HCT116 as well as human colon cancer stem cells Tu-12, Tu-21 and Tu-22. We showed here, in this study, that the synergistic effect of the multimodality treatment-induced apoptosis was caspase dependent and activated death signaling via both the extrinsic apoptotic pathway and the intrinsic pathway. Death signaling was activated by c-Jun N-terminal kinase (JNK) signaling which led to Bcl-xL phosphorylation at serine 62, decreasing the anti-apoptotic activity of Bcl-xL, which contributed to the intrinsic pathway. The downregulation of cellular FLICE inhibitory protein long isoform (c-FLIPL) in the extrinsic pathway was accomplished through ubiquitination at lysine residue (K) 195 and protein synthesis inhibition. Overexpression of c-FLIPL mutant (K195R) and Bcl-xL mutant (S62A) completely abrogated the synergistic effect. The successful outcome of this study supports the application of multimodality strategy to patients with colorectal hepatic metastases who fail to respond to standard chemoradiotherapy that predominantly targets the mitochondrial apoptotic pathway. © 2013 Song et al
Nonlinear structural behaviour and design formulae for calculating the ultimate strength of stiffened curved plates under axial compression
Cylindrically curved and stiffened plates are often used in ship and offshore structures. For example, they can be found in the cambered decks, fore and aft side shells and circular bilge parts of ships. A number of studies have investigated curved plates in which the buckling/ultimate strength is increased according to the curvature under various loading scenarios and design formulas. However, information regarding the nonlinear structural behaviour and design formulas for calculating the ultimate strength of the stiffened curved plates is currently limited. In this paper, a series of finite element analyses are performed on stiffened curved plates with varying geometric parameters. The existing curvatures are also analysed to clarify the effects of these parameters on the buckling/post-buckling characteristics and collapse behaviour under axial compression. The results are used to derive closed-form expressions to predict the ultimate compressive strength of curved stiffened plates for marine applications
Theatrical performance in the tourism industry: An Importance-Satisfaction Analysis
Theatrical performances have been developed quickly in many tourism destinations in China; however, little research has been focused on this important area. This study examined touristsâ perceptions towards The Romance of the Song Dynasty, one of the most successful performances targeted at tourists in China. Using Importance-Satisfaction Analysis (ISA), this study revealed that the most important and satisfied attributes by tourists were primarily associated with the core service attributes (i.e., performing art), whereas the most unimportant and dissatisfied attributes by tourists were mainly associated with the peripheral service attributes (i.e., venue environment, service, and tourist management). Both theoretical and practical contributions were provided in this study
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