3,860 research outputs found

    Toward a Fairness-Aware Scoring System for Algorithmic Decision-Making

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    Scoring systems, as a type of predictive model, have significant advantages in interpretability and transparency and facilitate quick decision-making. As such, scoring systems have been extensively used in a wide variety of industries such as healthcare and criminal justice. However, the fairness issues in these models have long been criticized, and the use of big data and machine learning algorithms in the construction of scoring systems heightens this concern. In this paper, we propose a general framework to create fairness-aware, data-driven scoring systems. First, we develop a social welfare function that incorporates both efficiency and group fairness. Then, we transform the social welfare maximization problem into the risk minimization task in machine learning, and derive a fairness-aware scoring system with the help of mixed integer programming. Lastly, several theoretical bounds are derived for providing parameter selection suggestions. Our proposed framework provides a suitable solution to address group fairness concerns in the development of scoring systems. It enables policymakers to set and customize their desired fairness requirements as well as other application-specific constraints. We test the proposed algorithm with several empirical data sets. Experimental evidence supports the effectiveness of the proposed scoring system in achieving the optimal welfare of stakeholders and in balancing the needs for interpretability, fairness, and efficiency

    Preparation of Metal-Free Nitrogen-Doped Carbon Material and Its Catalytic Performance

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    Nitrogen-doped carbon materials (NCMs) were prepared via hydrothermal treatment together with pyrolysis under nitrogen atmosphere by using melamine as nitrogen source and sucrose as carbon source. The NCMs were characterized by X-ray diffraction (XRD), laser Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results showed that nitrogen species were successfully doped into NCMs in the formation of pyridinic N, pyrrolic N, graphitic N, and oxidized N. With the temperature of pyrolysis increasing, the total amount of nitrogen species decreased, while the proportion of graphitic N increased. The catalytic performance was investigated by the reduction of p-nitrophenol with excessive KBH4 at 30 ℃. The reaction rate constant can reach 1.06 min-1 for NCM-800. The NCM-800 has good stability, which can be used for 8 cycles without obvious deactivation.

    Adaptive Semantic-Visual Tree for Hierarchical Embeddings

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    Merchandise categories inherently form a semantic hierarchy with different levels of concept abstraction, especially for fine-grained categories. This hierarchy encodes rich correlations among various categories across different levels, which can effectively regularize the semantic space and thus make predictions less ambiguous. However, previous studies of fine-grained image retrieval primarily focus on semantic similarities or visual similarities. In a real application, merely using visual similarity may not satisfy the need of consumers to search merchandise with real-life images, e.g., given a red coat as a query image, we might get a red suit in recall results only based on visual similarity since they are visually similar. But the users actually want a coat rather than suit even the coat is with different color or texture attributes. We introduce this new problem based on photoshopping in real practice. That's why semantic information are integrated to regularize the margins to make "semantic" prior to "visual". To solve this new problem, we propose a hierarchical adaptive semantic-visual tree (ASVT) to depict the architecture of merchandise categories, which evaluates semantic similarities between different semantic levels and visual similarities within the same semantic class simultaneously. The semantic information satisfies the demand of consumers for similar merchandise with the query while the visual information optimizes the correlations within the semantic class. At each level, we set different margins based on the semantic hierarchy and incorporate them as prior information to learn a fine-grained feature embedding. To evaluate our framework, we propose a new dataset named JDProduct, with hierarchical labels collected from actual image queries and official merchandise images on an online shopping application. Extensive experimental results on the public CARS196 and CUB

    Effect of mesenchymal stem cell transplantation on behavior and structural changes in myelin in experimental rat autoimmune encephalomyelitis

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    Purpose: To investigate the effect of bone marrow mesenchymal stem cell (BM-MSC) transplantation on behavior and structural changes in myelin of experimental autoimmune encephalomyelitis (EAE) in rats.Methods: Wistar rats were randomly assigned to normal control, EAE, placebo injection treatment, and MSCs treatment. EAE, placebo injection treatment and MSCs treatment groups were further divided into six groups, i.e., 1-day, 3-day, 7-day, 14-day, 21-day, and 28-day post-onset. Changes in the diseasestatus of the rats and structural changes in myelin at different time points were assessed with silver staining.Results: Behavioral changes peaked between 13 to 17 days post-immunization (71.90 % incidence), while disease symptoms peaked between 3 and 5 days after onset, were sustained for about 7 days, and then eased gradually thereafter. The highest therapeutic scores and the entire course of the disease in EAE and placebo treatment groups were not significantly different (p > 0.05). However, in MSC treatment group, these parameters were significantly lower than in the above two groups (p < 0.05). In EAE and placebo treatment groups, myelin sheath lesions were obvious from day 3 to 7 but on day 14, the number of myelin sheath fragments decreased significantly. Recovery at different time points was also better than those in EAE and placebo treatment groups.Conclusion: MSC transplantation shortens the course of EAE, and also reduces its severity. Thus, it has some prospects for use in the management of EAE.Keywords: Bone marrow mesenchymal stem cells, Autoimmune encephalomyelitis, Transplantation, Myeli

    Invasive reperfusion after 12 hours of the symptom onset remains beneficial in patients with ST-segment elevation myocardial infarction: Evidence from a meta-analysis of published data

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    Background: Early myocardial reperfusion therapy (< 12 h) in patients with acute myocardial infarc­tion (AMI) can significantly improve their prognosis. However, the effect of late reperfusion (> 12 h) remains controversial. In this study, the effects of late reperfusion versus standard drug therapy on the outcomes of patients with AMI were evaluated by systematic review and meta-analysis. Methods: PubMed, Embase, Medline, Cochrane, Wanfang, and CNKI databases were searched for eligible studies for the present study. Meta-analysis was performed using RevMan 5.3.3 software. Rela­tive risk (RR) and the 95% confidence interval (CI) were used to compare the outcomes between the two groups. The main outcome measures were major adverse cardiac events (MACEs), all-cause mortality, recurrent myocardial infarction (MI), and heart failure. Results: Eighteen studies were identified including 14,677 patients, of whom 5157 received late reperfusion with percutaneous coronary intervention (PCI) and 9520 received medication therapy (MT). Compared to MT, late PCI was associated with decreased all-cause mortality (RR 0.60, 95% CI 0.44–0.83; p = 0.002), MACEs (RR 0.67; 95% CI 0.50–0.89; p < 0.001), and heart failure (RR 0.76; 95% CI 0.60–0.97; p = 0.03), while there was also a trend toward decreased recurrent MI (RR 0.70; 95% CI 0.47–1.05; p = 0.08). However, subgroup analysis according to time to PCI showed that the clinical benefit was only from PCI after 12 h but not from 2 to 60 days of the onset of symptoms. Conclusions: The present meta-analysis suggested that PCI performed > 12 h but not 2–60 days after AMI is associated with significant improvement in clinical outcomes. However, these results need further rigorously designed large sample size clinical trials to be validated

    Cross-linked CoMoO4/rGO nanosheets as oxygen reduction catalyst

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    Development of inexpensive and robust electrocatalysts towards oxygen reduction reaction (ORR) is crucial for the cost-affordable manufacturing of metal-air batteries and fuel cells. Here we show that cross-linked CoMoO4 nanosheets and reduced graphene oxide (CoMoO4/rGO) can be integrated in a hybrid material under one-pot hydrothermal conditions, yielding a composite material with promising catalytic activity for oxygen reduction reaction (ORR). Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to investigate the efficiency of the fabricated CoMoO4/rGO catalyst towards ORR in alkaline conditions. The CoMoO4/rGO composite revealed the main reduction peak and onset potential centered at 0.78 and 0.89 V (vs. RHE), respectively. This study shows that the CoMoO4/rGO composite is a highly promising catalyst for the ORR under alkaline conditions, and potential noble metal replacement cathode in fuel cells and metal-air batteries

    Innovative minimally invasive implants for osteoporosis vertebral compression fractures

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    With increasing population aging, osteoporosis vertebral compression fractures (OVCFs), resulting in severe back pain and functional impairment, have become progressively common. Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) as minimally invasive procedures have revolutionized OVCFs treatment. However, PVP- and PKP-related complications, such as symptomatic cement leakage and adjacent vertebral fractures, continue to plague physicians. Consequently, progressively more implants for OVCFs have been developed recently to overcome the shortcomings of traditional procedures. Therefore, we conducted a literature review on several new implants for OVCFs, including StaXx FX, Vertebral Body Stenting, Vesselplasty, Sky Bone Expander, Kiva, Spine Jack, Osseofix, Optimesh, Jack, and V-strut. Additionally, this review highlights the individualized applications of these implants for OVCFs. Nevertheless, current clinical studies on these innovative implants remain limited. Future prospective, randomized, and controlled studies are needed to elucidate the effectiveness and indications of these new implants for OVCFs
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