3,001 research outputs found
Causality in Quantiles and Dynamic Stock Return-Volume Relations
This paper investigates the causal relations between stock return and volume based on quantile regressions. We first define Granger non-causality in all quantiles and propose testing non-causality by a sup-Wald test. Such a test is consistent against any deviation from non-causality in distribution, as opposed to the existing tests that check only noncausality in certain moment. This test is readily extended to test non-causality in different quantile ranges, and the testing results enable us to identify the quantile range for which causality is relevant. In the empirical studies of 3 major stock market indices, we find that, while the conventional test suggests no causality in mean, there are strong evidences that lagged volume Granger causes return in all but some middle quantiles. In particular, the causal effects have opposite signs at lower and upper quantiles and are stronger at more extreme quantiles. These relations form (symmetric) V shapes across quantiles. They also show that the dispersion of the return distribution increases with volume so that volume has a positive effect on return volatility. It is also shown that the quantile causal effects of lagged return on volume are mainly negative.Granger non-causality in quantiles, quantile causal effect, quantile regression, return-volume relation, sup-Wald test
The Effects of Green Energy Production on Farmland: A Case Study in Yunlin County, Taiwan
Taiwan enacted the Act of Renewable Energy in the year 2009 which promotes energy safety, green economy, and a sustainable environment, and with that the government envisages a contribution of photovoltaic energy of up to 20% by the year 2025. In this study we look into the motivation and background of this energy policy, plans for implementation and associated challenges, and its actual consequences for farmland use and farmers. In addition, we take a look into the implementation of mixed-use farmland in which agricultural activity and photovoltaic installations are planned to coexist in order to increase land value and productivity. We furthermore report on some of our findings related to a field survey conducted in Taiwan’s corn chamber of Yunlin County which has been facing a number of socioeconomic challenges
Application of Embryonic Stem Cells on Parkinson's Disease Therapy
Embryonic stem (ES) cells have the ability to reproduce themselves for a long period and differentiate into specific morphological and functional cells. The ES cells are an important material in developmental biology, genomics, and transgenic methods, as well as in potential clinical applications, gene therapy and tissue engineering. The pluripotent ES cells will be a valuable source in the treatment of numerous functional degenerative pathologies including Parkinson's disease (PD), which is characterized by progressive and selective loss of dopaminergic neurons in the midbrain substantia nigra. Thus, the most important for using ES cells in PD therapy is to direct their differentiation into dopaminergic phenotype to replace the degenerated cells. In this review, we summarize the neural differentiation directing protocol, transplantation results, and behavioral recovery of ES cells derived dopaminergic neurons in the therapeutic studies in PD animal models
Poly[(μ6-benzene-1,3,5-tricarboxylato-κ6 O 1:O 1′:O 3:O 3′:O 5:O 5′)tris(N,N-dimethylformamide-κO)tris(μ3-formato-κ2 O:O′)trimagnesium(II)]
The title complex, [Mg3(CHO2)3(C9H3O6)(C3H7NO)3]n, exhibits a two-dimensional structure parallel to (001), which is built up from the MgII atoms and bridging carboxylate ligands (3 symmetry). The MgII atom is six-coordinated by one O atom from a dimethylformamide molecule, two O atoms from two μ6-benzene-1,3,5-tricarboxylate ligands and three O atoms from three μ3-formate ligands in a distorted octahedral geometry
Rapid identification of Mycobacterium tuberculosis infection by a new array format-based surface plasmon resonance method
Tubercle bacillus [TB] is one of the most important chronic infectious diseases that cause millions of deaths annually. While conventional smear microscopy and culture methods are widely used for diagnosis of TB, the former is insensitive, and the latter takes up to 6 to 8 weeks to provide a result, limiting the value of these methods in aiding diagnosis and intermediate decisions on treatment. Therefore, a rapid detection method is essential for the diagnosis, prognosis assessment, and recurrence monitoring. A new surface plasmon resonance [SPR] biosensor based on an array format, which allowed immobilizing nine TB antigens onto the sensor chip, was constructed. Simultaneous determination of multiple TB antibodies in serum had been accomplished with this array-based SPR system. The results were compared with enzyme-linked immunosorbent assay, a conventional immunological method. Array-based SPR showed more advantages in providing label-free and real-time detection. Additionally, the high sensitivity and specificity for the detection of TB infection showed its potential for future development of biosensor arrays for TB diagnosis
Synthia's Melody: A Benchmark Framework for Unsupervised Domain Adaptation in Audio
Despite significant advancements in deep learning for vision and natural
language, unsupervised domain adaptation in audio remains relatively
unexplored. We, in part, attribute this to the lack of an appropriate benchmark
dataset. To address this gap, we present Synthia's melody, a novel audio data
generation framework capable of simulating an infinite variety of 4-second
melodies with user-specified confounding structures characterised by musical
keys, timbre, and loudness. Unlike existing datasets collected under
observational settings, Synthia's melody is free of unobserved biases, ensuring
the reproducibility and comparability of experiments. To showcase its utility,
we generate two types of distribution shifts-domain shift and sample selection
bias-and evaluate the performance of acoustic deep learning models under these
shifts. Our evaluations reveal that Synthia's melody provides a robust testbed
for examining the susceptibility of these models to varying levels of
distribution shift
Regulation of Skp2 Expression and Activity and Its Role in Cancer Progression
The regulation of cell cycle entry is critical for cell proliferation and tumorigenesis. One of the key players regulating cell cycle progression is the F-box protein Skp2. Skp2 forms a SCF complex with Skp1, Cul-1, and Rbx1 to constitute E3 ligase through its F-box domain. Skp2 protein levels are regulated during the cell cycle, and recent studies reveal that Skp2 stability, subcellular localization, and activity are regulated by its phosphorylation. Overexpression of Skp2 is associated with a variety of human cancers, indicating that Skp2 may contribute to the development of human cancers. The notion is supported by various genetic mouse models that demonstrate an oncogenic activity of Skp2 and its requirement in cancer progression, suggesting that Skp2 may be a novel and attractive therapeutic target for cancers
Poly[diaqua-μ4-biphenyl-4,4′-dicarboxylato-magnesium(II)]
The solvothermal reaction of magnesium nitrate with biphenyl-4,4′-dicarboxylic acid in N,N-dimethylformamide and water leads to the formation of crystals of the title complex, [Mg(C14H8O4)(H2O)2]n. In the crystal structure, the Mg cations are coordinated by six O atoms from two water molecules and four symmetry-related biphenyl-4,4′-dicarboxylate anions within slightly distorted octahedra. The Mg cations are located on a center of inversion, the biphenyl-4,4′-dicarboxylate anions around a twofold rotation axis and the water molecule in a general position. The Mg cations are linked by the anions into a three-dimensional framework
Effects of phorbol myristate acetate and sivelestat on the lung injury caused by fat embolism in isolated lungs
<p>Abstract</p> <p>Background</p> <p>Fat embolism syndrome (FES) associated with acute lung injury (ALI) is a clinical condition following long bone fracture. We have reported 14 victims due to ALI with FES. Our laboratory has developed an animal model that produced fat emboli (FE). The major purpose of this study was to test whether neutrophil activation with phorbol myristate acetate (PMA) and inhibition with sivelestat (SVT) exert protection on the lung.</p> <p>Methods</p> <p>The lungs of Sprague-Dawley rats were isolated and perfused. FE was produced by addition of corn oil micelles into the lung perfusate. PMA and SVT were given simultaneously with FE. Parameters such as lung weight/body weight ratio, LW gain, exhaled nitric oxide (NO), protein concentration in bronchoalveolar lavage relating to ALI were measured. The neutrophil elastase (NE), myeloperoxidase, malondialdehyde and phopholipase A<sub>2 </sub>activity were determined. We also measured the nitrate/nitrite, methyl guanidine (MG), and cytokines. Pulmonary arterial pressure and microvascular permeability were assessed. Lung pathology was examined and scored. The inducible and endothelial NO synthase (iNOS and eNOS) were detected.</p> <p>Results</p> <p>FE caused ALI and increased biochemical factors. The challenge also resulted in pulmonary hypertension and increased microvascular permeability. The NE appeared to be the first to reach its peak at 1 hr, followed by other factors. Coadministration with PMA exacerbated the FE-induced changes, while SVT attenuated the effects of FE.</p> <p>Conclusions</p> <p>The FE-induced lung changes were enhanced by PMA, while SVT had the opposite effect. Sivelestat, a neutrophil inhibitor may be a therapeutic choice for patients with acute respiratory distress syndrome (ARDS) following fat embolism.</p
PDA: Pooled DNA analyzer
BACKGROUND: Association mapping using abundant single nucleotide polymorphisms is a powerful tool for identifying disease susceptibility genes for complex traits and exploring possible genetic diversity. Genotyping large numbers of SNPs individually is performed routinely but is cost prohibitive for large-scale genetic studies. DNA pooling is a reliable and cost-saving alternative genotyping method. However, no software has been developed for complete pooled-DNA analyses, including data standardization, allele frequency estimation, and single/multipoint DNA pooling association tests. This motivated the development of the software, 'PDA' (Pooled DNA Analyzer), to analyze pooled DNA data. RESULTS: We develop the software, PDA, for the analysis of pooled-DNA data. PDA is originally implemented with the MATLAB(® )language, but it can also be executed on a Windows system without installing the MATLAB(®). PDA provides estimates of the coefficient of preferential amplification and allele frequency. PDA considers an extended single-point association test, which can compare allele frequencies between two DNA pools constructed under different experimental conditions. Moreover, PDA also provides novel chromosome-wide multipoint association tests based on p-value combinations and a sliding-window concept. This new multipoint testing procedure overcomes a computational bottleneck of conventional haplotype-oriented multipoint methods in DNA pooling analyses and can handle data sets having a large pool size and/or large numbers of polymorphic markers. All of the PDA functions are illustrated in the four bona fide examples. CONCLUSION: PDA is simple to operate and does not require that users have a strong statistical background. The software is available at
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