Although financial fraud detection research has made impressive progress because of advanced machine learning algorithms, constructing features (or attributes) that can effectively signal fraudulent ...behaviors remains a challenge. In recent years, a new type of fraud has emerged on peer-to-peer (P2P) lending platforms, where individuals can borrow money from others without a financial intermediary. In these markets, the information asymmetry problem is seriously elevated. Inspired by the fraud triangle theory and its extensions, and using the design science research methodology, we construct five categories of behavioral features directly from P2P lending transaction data, in addition to the baseline features regarding borrowers and loan requests. These behavioral features are intended to capture the fraud capability, integrity, and opportunity of fraudsters based on their loan requests and payment histories, connected peers, bidding process characteristics, and activity sequences. Using datasets from real users on two large P2P lending platforms in China, our evaluation results show that combining these additional features with the baseline features significantly enhances detection performance. This design science research contributes novel knowledge to the financial fraud detection literature and practice.
Background: In recent years, blockchain technology has attracted considerable attention. It records cryptographic transactions in a public ledger that is difficult to alter and compromise because of ...the distributed consensus. As a result, blockchain is believed to resist fraud and hacking. Results: This work explores the types of fraud and malicious activities that can be prevented by blockchain technology and identifies attacks to which blockchain remains vulnerable. Conclusions: This study recommends appropriate defensive measures and calls for further research into the techniques for fighting malicious activities related to blockchains.
We propose a research model based on media synchronicity theory (MST) and examine how the use of different symbol sets (e.g., images and text) is related to audience engagement on social media. We ...include uses and gratifications theory (UGT) in the model to identify task characteristics that are relevant to message recipients in the specific context of community policing. Based on our analyses of Facebook posts by five police departments, we find first that, consistent with MST, posts conveying information garner more responses when accompanied by more natural symbol sets, and more textual content is preferred to less, but responses differ depending on the type of engagement: intimacy (likes), interaction (comments), or influence (shares). Second, posts intended for meaning convergence gratify the audience's socialization and assistance needs and are positively related to intimacy and interaction. Finally, the fit between symbol sets and task characteristics impacts different dimensions of audience engagement. These findings provide empirical support for relying on MST when studying social media and for integrating with UGT to capture contextual task characteristics. We conclude the paper with a discussion of the implications of its findings for theory and offer recommendations for practice.
The limited information provided by peer-to-peer (P2P) lending platforms often is not sufficient for lenders to determine if a borrower is trustworthy and able to repay the loan. Using a unique ...dataset from a P2P lending platform, which allows lenders to seek information directly from borrowers and borrowers to respond to the questions and comments, we examine the impact of lender-borrower communication on funding outcomes and loan performance. Our results show that not only the amount but also the content of such direct communication matters. Specifically, the number of lender comments is negatively associated with funding success, while the number of borrower responses is positively associated with funding success, although only comments help reduce the final interest rate. The role of the communication is even stronger for listings with poor credit grades. Moreover, lenders are influenced by other lenders’ (positive or negative) comments and the quality of the information disclosed in borrower responses can affect funding outcomes. Loan performance (e.g., default ratio), however, cannot be predicted based on the amount of lender borrower communication. This research broadens and deepens our understanding of the roles of information disclosure, social influence, information quality, and trust in economic exchanges in online settings.
Many people face problems of emotional distress. Early detection of high-risk individuals is the key to prevent suicidal behavior. There is increasing evidence that the Internet and social media ...provide clues of people's emotional distress. In particular, some people leave messages showing emotional distress or even suicide notes on the Internet. Identifying emotionally distressed people and examining their posts on the Internet are important steps for health and social work professionals to provide assistance, but the process is very time-consuming and ineffective if conducted manually using standard search engines. Following the design science approach, we present the design of a system called KAREN, which identifies individuals who blog about their emotional distress in the Chinese language, using a combination of machine learning classification and rule-based classification with rules obtained from experts. A controlled experiment and a user study were conducted to evaluate system performance in searching and analyzing blogs written by people who might be emotionally distressed. The results show that the proposed system achieved better classification performance than the benchmark methods and that professionals perceived the system to be more useful and effective for identifying bloggers with emotional distress than benchmark approaches.
A variety of organizations around the world use complex information systems (e.g., enterprise resource planning and supply chain management systems). However, poor usability caused by system ...complexity continues to frustrate users and damage the reputation of these systems. In this study, we address usability issues with complex information systems from the human-computer collaboration perspective by modeling user-system interaction as a joint activity between the system and its users. We propose a conceptual model for user-system collaboration, elaborate on the components in the model and the relationships between the components, derive the required capabilities for collaborative information systems, and establish conceptual relationships between system collaborative behaviors and usability. We use empirical evidence gathered from a qualitative field study on ERP systems to illustrate the model and the possible impact of system collaborativeness (i.e., the presence or absence of collaborative capabilities) on usability. We do so to provide a strong conceptual foundation for modeling user-system collaboration and to encourage designers to employ the collaboration metaphor during system design and, thus, help them develop future complex information systems with better usability.
The role of microRNAs (miRNAs) in mediating adult neurogenesis after stroke has not been extensively studied. The present study investigated the function of the miR17-92 cluster in adult neural ...progenitor cells after experimental stroke. We found that stroke substantially up-regulated miR17-92 cluster expression in neural progenitor cells of the adult mouse. Overexpression of the miR17-92 cluster either in cultured ischemic neural progenitor cells or in the subventricular zone (SVZ) of ischemic animals significantly increased cell proliferation, whereas inhibition of individual members of the miR17-92 cluster, miR-18a and miR-19a, suppressed cell proliferation and increased cell death. The miR17-92 cluster mediated PTEN (phosphatase and tensin homolog) expression, which is a predicted target of the miR17-92 cluster. Addition of Sonic hedgehog (Shh) protein up-regulated miR17-92 expression and elevated c-Myc protein in ischemic neural progenitor cells, whereas blockade of the Shh signaling pathway down-regulated miR17-92 cluster expression and reduced c-Myc levels. Overexpression of c-Myc up-regulated miR17-92 cluster expression. Intraventricular infusion of Shh and a Shh receptor inhibitor, cyclopamine, to ischemic animals further elevated and suppressed, respectively, miR17-92 cluster expression in the SVZ. These data indicate that the miR17-92 cluster plays an important role in mediating neural progenitor cell function and that the Shh signaling pathway is involved in up-regulating miR17-92 cluster expression.
Background: The role of miRNAs in mediating stroke-induced neurogenesis remains largely unknown.
Results: The miR17-92 cluster regulated ischemia-induced neural progenitor cell proliferation, and activation of the Shh pathway up-regulated miR17-92 cluster expression.
Conclusion: The miR17-92 cluster plays an important role in mediating adult neural progenitor cell proliferation.
Significance: The present study provides molecular mechanisms underlying miR17-92 cluster in mediating stroke-induced neurogenesis.
Background
Fluoroquinolone resistance is an issue of concern amongst physicians worldwide. In urology, fluoroquinolones are often used in the treatment of acute pyelonephritis and prostatitis, as ...well as infections caused by multidrug‐resistant pathogens.
Aims
We aim to highlight the importance of antimicrobial stewardship and the need for ongoing biomedical research to discover novel agents in our losing battle against resistant pathogens.
Materials and methods
In this review, we survey the literature and summarise fluoroquinolone resistance as it pertains to pyelonephritis and prostatitis, as well as alternative treatment strategies and prevention of multidrug resistance.
Results
The rise of fluoroquinolone resistance in bacteria has reduced the available treatment options, often necessitating hospital admission for intravenous antibiotics, which places an additional burden on both patients and the healthcare system. Many countries such as Australia have attempted to limit fluoroquinolone resistance by imposing strict prescribing criteria, though these efforts have not been entirely successful. Solutions to overcome resistance include prevention, combination therapy and the development of novel antimicrobial agents.
Conclusions
Prevention of the proliferation of resistant organisms by antimicrobial stewardship is paramount, and urologists are obliged to be aware of responsible prescribing practices such as referring to local guidelines when prescribing. By reserving fluoroquinolones for infections in which they are truly indicated and by prescribing based on both patient and local environmental factors, we can preserve this effective resource for future use.
Purpose:
Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured ...by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates.
Methods:
The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors’ previous work K. Taguchi
et al.
, “Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects,” Med. Phys.
38(2), 1089–1102 (2011). The agreement between the x-ray spectra calculated by the cascaded SRE+PPE model and the measured spectra was evaluated for various levels of deadtime loss ratios (DLR) and incident spectral shapes, realized using different attenuators, in terms of the weighted coefficient of variation (COVW), i.e., the root mean square difference weighted by the statistical errors of the data and divided by the mean.
Results:
At low count rates, when DLR < 10%, the distorted spectra measured by the DXMCT-1 were in agreement with those calculated by SRE only, with COVW's less than 4%. At higher count rates, the measured spectra were also in agreement with the ones calculated by the cascaded SRE+PPE model; with PMMA as attenuator, COVW was 5.6% at a DLR of 22% and as small as 6.7% for a DLR as high as 55%.
Conclusions:
The x-ray spectra calculated by the proposed model agreed with the measured spectra over a wide range of count rates and spectral shapes. The SRE model predicted the distorted, recorded spectra with low count rates over various types and thicknesses of attenuators. The study also validated the hypothesis that the complex spectral distortions in a PCD can be adequately modeled by cascading the count-rate independent SRE and the count-rate dependent PPE.
The reliability of isokinetic peak torque (PT) has been reported mostly using a short-term (<~10 day) inter-trial testing time frame. However, many studies and programs utilize a long-term (several ...weeks to months) inter-trial testing period. Additionally, the methods by which the PT value is selected and reported from a multiple rep testing scheme have not been well investigated for both reliability and PT absolute performance comparisons. The purpose of this study was to investigate the long-term reliability of isokinetic and isometric PT of the leg extensors with an emphasis on the differences among several PT score selection methods. Thirteen men and women (age = 19.5 years) underwent two testing trials separated by 28.8 (±1.8) days. Testing included maximal voluntary contractions of three sets of three reps for two isokinetic contraction conditions of 60 (Isok60) and 240 (Isok240) deg/s velocities, and three sets of one rep of isometric contractions for the leg extensors. The PT score was derived from seven different methods (see text for descriptions). Reliability as assessed from intraclass correlation coefficients (ICCs) varied widely across contraction conditions and PT score selection parameters. The Isok60 velocity overall had lower reliability (ICCs = 0.48-0.81) than Isok240 (0.77-0.87) across the conditions whereas the isometric PT variables showed moderate reliability (0.71-0.73). Overall the set 1 PT score selection parameters were generally lower (
≤ 0.05) than those that involved sets two and three. Systematic error (
≤ 0.05) was shown for 6 out of the 17 PT selection variables. On a subjective interpretation basis, when taking everything into account the best overall combination of time/trial efficiency, reliability, best/highest PT score parameter, and reduced risk of systematic bias appears to be the PT variable that uses the average of the highest two reps of the first two sets of three reps-i.e., averaging the highest two values of the six total reps from the first two sets.