32 research outputs found
Empirical Study on the Organizational Commitment of IT Expatriates in Different Matching Patterns of Employeesā and Enterprisesā Psychological Contracts
With the rapid development in China\u27s IT outsourcing industry, the number of employees in software outsourcing enterprises increases rapidly. IT expatriates not only bring huge economic benefits to the software company, but also reduce the customersā development and operation costs, improving IT performance. However, since these expatriates who are away from the parent company, are working in customer side for a long time, and do not belong to the client company either, they are always regarded as āthird country citizensā. Thus, identity disorder and lack of organizational commitment to their parent companies are always haunting around them. This paper studies the influences of employeesā and enterprisesā psychological contract in different matching patterns on organizational commitment by empirical analysis method. This research finds that employeesā relational psychological contract has a higher positive influence on organizational commitment than employeesā transactional psychological contract in both matching and mismatching situation, while enterprisesā relational psychological contract only affects the organizational commitment more positively than the transactional psychological contract in a matching situation. The employees of mutual-loyalty pattern and employee-dominating pattern will have a stronger organizational commitment in matching and mismatching situation separately. This research develops the relevant theory of psychological contract and organizational commitment in the background of IT outsourcing, improving the staff management for IT outsourcing enterprises efficiently
Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks
Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitude-modulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve healthy subjects. Taking advantage of the ASL noise properties, we were able to study tonic CBF changes during uninterrupted 6-min continuous performance of working memory and sustained attention tasks. For the visual sustained attention task, regional CBF increases (6ā12 ml/100 g/min) were detected in the right middle frontal gyrus, the bilateral occipital gyri, and the anterior cingulate/medial frontal gyri. During the 2-back working memory task, significantly increased activations (7ā11 ml/100 g/min) were found in the left inferior frontal/precentral gyri, the left inferior parietal lobule, the anterior cingulate/medial frontal gyri, and the left occipital gyrus. Locations of activated and deactivated areas largely concur with previous PET and BOLD fMRI studies utilizing similar paradigms. These results demonstrate that CASL perfusion fMRI can be successfully utilized for the investigation of the tonic CBF changes associated with high level cognitive operations. Increased applications of the method to the investigation of cognitively impaired populations are expected to follow
Text-Video Retrieval via Variational Multi-Modal Hypergraph Networks
Text-video retrieval is a challenging task that aims to identify relevant
videos given textual queries. Compared to conventional textual retrieval, the
main obstacle for text-video retrieval is the semantic gap between the textual
nature of queries and the visual richness of video content. Previous works
primarily focus on aligning the query and the video by finely aggregating
word-frame matching signals. Inspired by the human cognitive process of
modularly judging the relevance between text and video, the judgment needs
high-order matching signal due to the consecutive and complex nature of video
contents. In this paper, we propose chunk-level text-video matching, where the
query chunks are extracted to describe a specific retrieval unit, and the video
chunks are segmented into distinct clips from videos. We formulate the
chunk-level matching as n-ary correlations modeling between words of the query
and frames of the video and introduce a multi-modal hypergraph for n-ary
correlation modeling. By representing textual units and video frames as nodes
and using hyperedges to depict their relationships, a multi-modal hypergraph is
constructed. In this way, the query and the video can be aligned in a
high-order semantic space. In addition, to enhance the model's generalization
ability, the extracted features are fed into a variational inference component
for computation, obtaining the variational representation under the Gaussian
distribution. The incorporation of hypergraphs and variational inference allows
our model to capture complex, n-ary interactions among textual and visual
contents. Experimental results demonstrate that our proposed method achieves
state-of-the-art performance on the text-video retrieval task
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Biogeographic patterns and drivers of soil viromes
Viruses are crucial in shaping soil microbial functions and ecosystems. However, studies on soil viromes have been limited in both spatial scale and biome coverage. Here we present a comprehensive synthesis of soil virome biogeographic patterns using the Global Soil Virome dataset (GSV) wherein we analysed 1,824 soil metagenomes worldwide, uncovering 80,750 partial genomes of DNA viruses, 96.7% of which are taxonomically unassigned. The biogeography of soil viral diversity and community structure varies across different biomes. Interestingly, the diversity of viruses does not align with microbial diversity and contrasts with it by showing low diversity in forest and shrubland soils. Soil texture and moisture conditions are further corroborated as key factors affecting diversity by our predicted soil viral diversity atlas, revealing higher diversity in humid and subhumid regions. In addition, the binomial degree distribution pattern suggests a random co-occurrence pattern of soil viruses. These findings are essential for elucidating soil viral ecology and for the comprehensive incorporation of viruses into soil ecosystem models
Identification and characterization of the mitochondrial RNA polymerase and transcription factor in the fission yeast Schizosaccharomyces pombe
We have characterized the mitochondrial transcription factor (Mtf1) and RNA polymerase (Rpo41) of Schizosaccharomyces pombe. Deletion mutants show Mtf1 or Rpo41 to be essential for cell growth, cell morphology and mitochondrial membrane potential. Overexpression of Mtf1 and Rpo41 can induce mitochondrial transcription. Mtf1 and Rpo41 can bind and transcribe mitochondrial promoters in vitro and the initiating nucleotides were the same in vivo and in vitro. Mtf1 is required for efficient transcription. We discuss the functional differences between Mtf1 and Rpo41 of S. pombe with Saccharomyces cerevisiae and higher organisms. In contrast to S. cerevisiae, the established model for mitochondrial transcription, S. pombe, a petite-negative yeast, resembles higher organisms that cannot tolerate the loss of mitochondrial function. The S. pombe and human mitochondrial genomes are similar in size and much smaller than that of S. cerevisiae. This is an important first step in the development of S. pombe as an alternative and complementary model system for molecular genetic and biochemical studies of mitochondrial transcription and mitochondrialānuclear interactions. This is the first systematic study of the cellular function and biochemistry of Rpo41 and Mtf1 in S. pombe
Visualizing vein patterns from color skin images based on image mapping for forensics analysis
Traditionally, it was difficult to use vein patterns in evidence images for forensic identification, because they were nearly invisible in color images. We proposed a computational method based on skin optics to uncover vein patterns from color images. However, its performance is dependent on the accuracy of the skin optical model. In this paper, we propose an algorithm based on image mapping to visualize vein patterns. It extracts information from a pair of synchronized color and near infrared (NIR) images, and uses a neural network (NN) to map RGB values to NIR intensities. In addition, an NN weight adjustment scheme is proposed to improve the robustness of the algorithm. The proposed algorithm was examined on a database with 300 pairs of color and NIR images collected from the forearms of 150 subjects. The automatic matching results from the proposed algorithm were better than those from our previous method, and comparable to the results from matching NIR images with NIR images
Matching vein patterns from color images for forensic investigation
Child sexual abuse is a serious global problem and has gained public attention in recent years. Due to the popularity of digital cameras, many perpetrators take images of their sexual activities with child victims. Traditionally, it was difficult to use cutaneous vascular patterns for forensic identification, because they were nearly invisible in color images. Recently, this limitation was overcome using a computational method based on an optical model to uncover vein patterns from color images for forensic verification. This optical-based vein uncovering (OBVU) method is sensitive to the power of the illuminant and does not utilize skin color in images to obtain training parameters to optimize the vein uncovering performance. Prior publications have not included an automatic vein matching algorithm for forensic identification. As a result, the OBVU method only supported manual verification. In this paper, we propose two new schemes to overcome limitations in the OBVU method. Specifically, a color optimization scheme is used to derive the range of biophysical parameters to obtain training parameters and an automatic intensity adjustment scheme is used to enhance the robustness of the vein uncovering algorithm. We also developed an automatic matching algorithm for vein identification. This algorithm can handle rigid and non-rigid deformations and has an explicit pruning function to remove outliers in vein patterns. The proposed algorithms were examined on a database with 300 pairs of color and near infrared (NIR) images collected from the forearms of 150 subjects. The experimental results are encouraging and indicate that the proposed vein uncovering algorithm performs better than the OBVU method and that the uncovered patterns can potentially be used for automatic criminal and victim identification
Foodborne TiO2 Nanoparticles Induced More Severe Hepatotoxicity in Fructose-Induced Metabolic Syndrome Mice via Exacerbating Oxidative Stress-Mediated Intestinal Barrier Damage
The hazard of titanium dioxide nanoparticles (TiO2 NPs) in diseased population should be given focus due to the huge number of these NPs in foods and medicine. This study aimed to evaluate the stronger biological adverse effect of oral exposure to TiO2 NPs in a fructose-induced metabolic syndrome mouse model. Compared to the normal mice, low-dose (2 mg/kg) TiO2 NPs did not cause severe hepatotoxicity. However, high-dose (20 mg/kg) TiO2 NPs induced aggravated hepatic inflammation, fibrosis, and apoptosis, with substantial alteration of related biochemical parameters in the mouse model. Moreover, significantly increased Ti and lipopolysaccharide burden were observed in metabolic syndrome murine liver and serum, which possibly worsened the portend intestinal leakage. The expression of tight junction-related protein showed that TiO2 NPs induced further increase in serious intestinal permeability. The intestinal inflammatory and oxidative stress response in the model were also assessed. Results showed that TiO2 NPs caused more severe intestinal inflammatory injury by intensifying the oxidative stress in metabolic syndrome mice and then induced further liver injury. This work provides information on the insights into the toxic effect of TiO2 NPs in sub-healthy population
Mechanical Properties Damage, Fracture Evolution, and Constitutive Model of Siltstone under the Effect of Moisture Content
In order to study the weakening mechanism of mechanical properties and the evolution of fracture of water-bearing rocks, cylindrical standard siltstone samples with four moisture contents (0, 2.85, 3.87, and 4.25%) were prepared, and the mechanical properties, damage mode, AE characteristics, and fractal law of water-bearing rock samples were studied by means of uniaxial compression test and acoustic emission (AE) monitoring technique, and based on the test findings, a constitutive model of the entire process of rock deformation and damage under uniaxial compression was built with different moisture content of rock. The results show that with the increase of moisture content, the peak stress, the stress threshold of void compaction stage, and the stress threshold of elastic stage of the rock samples decreased linearly, elastic modulus decreased exponentially as a function, and the peak strain, the strain threshold of void compaction stage, and the strain threshold of elastic stage increased linearly. The higher the moisture content, the weaker the AE signal intensity and the smaller the AE count value. From dry to saturated, the damage form of rock samples gradually transitioned from predominantly tensile damage to predominantly shear damage. The fractal dimension of the broken block linearly decreases as the moisture content rises. The model constructed in this paper has good applicability to the deformation characteristics of water-bearing rocks under uniaxial compression before the peak stress; it especially can express the rock void compaction stage, but it cannot accurately describe the postpeak deformation characteristics