Impacts of Live Chat on Refund Intention: Evidence from an Online Labor Market

Live chat plays a significant role in online labor markets, which mitigates the information asymmetry caused by the highly customized nature of service products. This study examines the impacts of live chat on refund intention in online labor markets and how these impacts are moderated by business familiarity. We collect unique archived data from a leading online labor market in Asia and hypothesize that reply speed has a negative effect on refund intention while both politeness intensity and sentiment intensity have a U-shaped effect on refund intention. In addition, these effects are proposed to be weakened by business familiarity formed by previous transaction experience. The study not only offers theoretical contributions to the online labor market literature by providing empirical insights on the impact of live chat on refund intention but also yields managerial implications for service providers and platform operators

A novel machine-vision-based facility for the automatic evaluation of yield-related traits in rice

The evaluation of yield-related traits is an essential step in rice breeding, genetic research and functional genomics research. A new, automatic, and labor-free facility to automatically thresh rice panicles, evaluate rice yield traits, and subsequently pack filled spikelets is presented in this paper. Tests showed that the facility was capable of evaluating yield-related traits with a mean absolute percentage error of less than 5% and an efficiency of 1440 plants per continuous 24 h workday

Unsupervised Visible-Infrared Person ReID by Collaborative Learning with Neighbor-Guided Label Refinement

Unsupervised learning visible-infrared person re-identification (USL-VI-ReID) aims at learning modality-invariant features from unlabeled cross-modality dataset, which is crucial for practical applications in video surveillance systems. The key to essentially address the USL-VI-ReID task is to solve the cross-modality data association problem for further heterogeneous joint learning. To address this issue, we propose a Dual Optimal Transport Label Assignment (DOTLA) framework to simultaneously assign the generated labels from one modality to its counterpart modality. The proposed DOTLA mechanism formulates a mutual reinforcement and efficient solution to cross-modality data association, which could effectively reduce the side-effects of some insufficient and noisy label associations. Besides, we further propose a cross-modality neighbor consistency guided label refinement and regularization module, to eliminate the negative effects brought by the inaccurate supervised signals, under the assumption that the prediction or label distribution of each example should be similar to its nearest neighbors. Extensive experimental results on the public SYSU-MM01 and RegDB datasets demonstrate the effectiveness of the proposed method, surpassing existing state-of-the-art approach by a large margin of 7.76% mAP on average, which even surpasses some supervised VI-ReID methods

Temporal and spatial variations of macrofouling organisms on ecological floating beds in Yundang Lagoon, China

Abstract(#br)Spatial-temporal variations of macrofouling organisms that attach to ecological floating beds (EFBs) in the Yundang Lagoon were investigated to identify factors that influence the appearance of macrofouling organisms. Results show that the composition, abundance, biomass, and dominance of macrofouling organisms on EFBs exhibited significant seasonal variation. Pearson correlation analysis indicates that the abundance and biomass of the bivalve Mytilopsis sallei showed negative correlation with root biomass ( p < 0.05) and particulate matter ( p < 0.05). Environmental (temperature and salinity, p < 0.05) and biological (bottom-up control) factors are the main drivers of population turnover. There were significant species differences of macrofouling organisms within the different parts of the lagoon, which were attributed to environmental characteristics such as hydrodynamics, dissolved oxygen, and the degree of eutrophication. Results of this study provide a basis for controlling macrofouling organisms, while improving the stability of EFBs and the efficiency of ecological restoration

Parametric Images in Assessing Bone Grafts Using Dynamic 18F-Fluoride PET

The early identification of graft failure would improve patient management. 18F-fluoride is a suitable tracer for quantifying bone metabolism. Performance of parametric images constructed by Patlak graphical analysis (PGA) with various time periods was evaluated in the analysis of dynamic 18F-fluoride PET studies of eight patients with fibula bone grafts after limb salvage surgery. The PGA parametric image approach tended to underestimate influx rate. The linear portion of PGA analysis was found to be from 10 to 50 min. It shows promise in providing a quantitative assessment of the viability of bone grafts

Efficacy and safety of ultra-short wave diathermy on COVID-19 pneumonia: a pioneering study

BackgroundThe ultra-short wave diathermy (USWD) is widely used to ameliorate inflammation of bacterial pneumonia, however, for COVID-19 pneumonia, USWD still needs to be verified. This study aimed to investigate the efficacy and safety of USWD in COVID-19 pneumonia patients.MethodsThis was a single-center, evaluator-blinded, randomized controlled trial. Moderate and severe COVID-19 patients were recruited between 18 February and 20 April 2020. Participants were randomly allocated to receive USWD + standard medical treatment (USWD group) or standard medical treatment alone (control group). The negative conversion rate of SARS-CoV-2 and Systemic Inflammatory Response Scale (SIRS) on days 7, 14, 21, and 28 were assessed as primary outcomes. Secondary outcomes included time to clinical recovery, the 7-point ordinal scale, and adverse events.ResultsFifty patients were randomized (USWD, 25; control, 25), which included 22 males (44.0%) and 28 females (56.0%) with a mean (SD) age of 53 ± 10.69. The rates of SARS-CoV-2 negative conversion on day 7 (p = 0.066), day 14 (p = 0.239), day 21 (p = 0.269), and day 28 (p = 0.490) were insignificant. However, systemic inflammation by SIRS was ameliorated with significance on day 7 (p = 0.030), day 14 (p = 0.002), day 21 (p = 0.003), and day 28 (p = 0.011). Time to clinical recovery (USWD 36.84 ± 9.93 vs. control 43.56 ± 12.15, p = 0.037) was significantly shortened with a between-group difference of 6.72 ± 3.14 days. 7-point ordinal scale on days 21 and 28 showed significance (p = 0.002, 0.003), whereas the difference on days 7 and 14 was insignificant (p = 0.524, 0.108). In addition, artificial intelligence-assisted CT analysis showed a greater decrease in the infection volume in the USWD group, without significant between-group differences. No treatment-associated adverse events or worsening of pulmonary fibrosis were observed in either group.ConclusionAmong patients with moderate and severe COVID-19 pneumonia, USWD added to standard medical treatment could ameliorate systemic inflammation and shorten the duration of hospitalization without causing any adverse effects.Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2000029972

CT-based radiomics for predicting pathological grade in hepatocellular carcinoma

ObjectiveTo construct and validate radiomics models for hepatocellular carcinoma (HCC) grade predictions based on contrast-enhanced CT (CECT).MethodsPatients with pathologically confirmed HCC after surgery and underwent CECT at our institution between January 2016 and December 2020 were enrolled and randomly divided into training and validation datasets. With tumor segmentation and feature extraction, radiomic models were constructed using univariate analysis, followed by least absolute shrinkage and selection operator (LASSO) regression. In addition, combined models with clinical factors and radiomics scores (Radscore) were constructed using logistic regression. Finally, all models were evaluated using the receiver operating characteristic (ROC) curve with the area under the curve (AUC), calibration curve, and decision curve analysis (DCA).ResultsIn total 242 patients were enrolled in this study, of whom 170 and 72 formed the training and validation datasets, respectively. The arterial phase and portal venous phase (AP+VP) radiomics model were evaluated as the best for predicting HCC pathological grade among all the models built in our study (AUC = 0.981 in the training dataset; AUC = 0.842 in the validation dataset) and was used to build a nomogram. Furthermore, the calibration curve and DCA indicated that the AP+VP radiomics model had a satisfactory prediction efficiency.ConclusionsLow- and high-grade HCC can be distinguished with good diagnostic performance using a CECT-based radiomics model

Impact of cage aquaculture on water exchange in Sansha Bay

Abstract(#br)Influence of cage aquaculture on the flow field and water exchange in Sansha Bay is investigated based on in situ current measurements and output from a two-dimensional shallow water hydrodynamic finite element model (SHYFEM). Without cage influence, the flow is relatively uniform in the vertical except a bottom Ekman layer. An asymmetry of tidal current speed is also observed in Sansha Bay with a dominance of the ebb tide. Near-surface current speed squared in cage-free area is typically larger than that within cage area by a factor exceeding three in deep channels, and by a factor of two in tidal flats. Current speed profiles suggest that cage-induced drag on the flow field can reach as deep as 20 m in the relatively deep channels of Sansha Bay. A set of numerical experiments are designed to quantify the relative effect of cages in tidal flats and channels, respectively, on water exchange using SHYFEM. It is shown that cage aquaculture weakens the local flow but seems to strengthen the flow adjacent to cages. Reducing the frictional drag in channels significantly increases the water exchange rate both locally and in the near-field tidal flats. Therefore, certain clearance or rearrangement of cage aquaculture in channels would be more effective in improving the water exchange in the entire Sansha Bay

Analysis of solids with different matrices by buffer-gas-assisted laser ionization orthogonal time-of-flight mass spectrometry

A laser ionization orthogonal time-of-flight mass spectrometer with a low-pressure source and high laser irradiance was used to analyze 27 solid samples with 9 different matrices, including aluminium, soil, copper sulfide, zinc sulfide, iron, nickel, copper, zinc, and tungsten. The influence of laser energy on non-stoichiometric effects, such as matrix effects and elemental fractionation, has been investigated. The results indicate that matrix effects can be alleviated to a great extent at high laser irradiance. Additionally, with the irradiance of 10(10)-10(11) Wcm(-2), most elements presented relatively stable relative sensitivity coefficients (RSC), while W, Pb, and Bi demonstrated unusual characteristics that their RSCs increased along with increasing laser energy.National 863 program ; Natural Science Foundation of China ; Fujian Province Department of Science Technolog