Search Results (311)

Utilizing a dataset of 190 risk factors spanning over three decades, we apply a swarm-based classification model to estimate factor velocity and analyze its implications for asset pricing. Our results show that slower-moving factors generate higher abnormal returns than their faster-moving counterparts, underscoring the critical role of price adjustment speed in market dynamics. Furthermore, our results suggest that trading frictions impede the rapid assimilation of information, contributing to the observed return patterns. This research offers new insights into return predictability and demonstrates the potential of swarm intelligence as a powerful tool for financial modeling. Full article

We construct a novel hand-collected large dataset of 205 U.S. hedge funds and 1025 activist events over the period 2005–2013, which records both the Schedule 13D filing date and the voice date, and explore the role of voice in value creation. We employ alternative inferential statistical approaches, including parametric, non-parametric, and heteroscedasticity-robust tests. We reveal that the voice date is important in creating short-term firm value and provide strong evidence that voice is associated with positive abnormal returns. These findings suggest that voice leads to information revelation, with implications for U.S. stock market arbitrage. Full article

Gulf War Veterans (GWVs) presenting with irritable bowel syndrome-diarrhea (IBS-D) often exhibit concurrent post-traumatic stress disorder (PTSD) or traumatic brain injury (TBI). All Veterans’ Affair physicians are required to assess symptoms of depression, anxiety, and suicide ideation by maintaining yearly training. In a previous study for IBS-D (3), we identified significant vitamin D deficiency (VDD), with an average level of 19 ng/mL. This includes those with and without PTSD, TBI, showing depression and anxiety symptoms. Since VDD is associated with PTSD, and all veterans not on supplementation were found to be VDD (>90%) at our facility, we investigated a possible association between VDD and these neuropsychological conditions. While age and body mass index (BMI), seasons, and demographic locations are known to affect vitamin D levels, we found no correlation between these factors and VDD in the PTSD group and those with IBS-D. In the TBI group, VDD did correlate with BMI. Multiple deployments appeared to have a minor negative effect on vitamin D levels (a 11–13% contribution) in veterans with either PTSD or TBI. Although these veterans showed signs of inflammation with elevated minor C-reactive protein (CRP) levels (4.7 mg/L), there was a negative correlation between CRP and vitamin D to suggest that inflammation is not the primary cause of PTSD or TBI. Following daily vitamin D treatment, vitamin D levels returned to a normal average of 30 ng/mL (less than 30 ng/mL is abnormal). Treatment had no effect on serum calcium levels, but did lead to a resolution of depression, anxiety, TBI, and PTSD symptoms in the majority of patients. These findings suggest that correcting VDD in GWVs visiting GI clinics with co-occurring PTSD and TBI had reduced psychological symptoms. Replacing vitamin D is a simple strategy to implement, rather than increasing neurotrophic medications in some patients. Full article

The rise of fintech has disrupted traditional financial services, prompting banks and asset managers to respond strategically, often through mergers and acquisitions. This study investigates the short-term market reaction to M&A announcements involving fintech targets by incumbent financial institutions. Using an event study methodology centered on different event windows and cumulative abnormal returns computed via the market model, the analysis incorporates regression models with bidder-, deal-, and target-level variables to identify the drivers of performance. The results show that, on average, financial institutions experience negative abnormal returns around announcement dates, suggesting limited short-term value creation. Higher market-to-book ratios and tax rates are positively associated with CARs, while lower profit margins are linked to better market reactions. Subsample comparisons reveal that U.S. acquirers underperform their European peers, commercial banks fare worse than asset managers and investment banks, and pre-COVID-19 deals yield more favorable returns than post-COVID-19 ones. Robustness checks using different market benchmarks demonstrate that key patterns—especially those related to geography and timing—are sensitive to benchmark selection. Overall, this study highlights market skepticism toward fintech acquisitions by traditional financial institutions, particularly in specific contexts, and emphasizes the importance of controlling for structural factors when interpreting abnormal returns. Full article

Bypass graft is widely used, especially in cardiovascular diseases, to detour clogged blood vessels, alleviating and correcting the manifestation of the symptoms of damaged blood vessels. Bypass grafting is also used in hemodialysis treatment, specifically an arteriovenous bypass graft, considering the repeated withdrawal of blood, for the dialysis machine to filter the blood and return it to the body to circulate. Nonetheless, bypass grafts are susceptible to failure due to the abnormal hemodynamic performance of the blood flowing to the graft, leading to complications such as thrombosis, intimal hyperplasia, and atherosclerosis. Multiple bypass graft designs are continuously developed to optimize the desirable hemodynamics of the blood, which is essential to avoid complications. This study examines helical arteriovenous bypass graft (AVG) hemodynamic performance using Computational Fluid Dynamics (CFD) simulations to identify enhanced blood flow characteristics. The analysis concentrated on area-weighted average wall shear stress (AWA-WSS), helicity, pressure drop, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) from twenty-seven graft models changing anastomosis angles, helical diameters, and helical pitches. Model 25-13-30 (25-degree anastomosis angle, 13 mm helical diameter, 30 mm helical pitch) demonstrated the most favorable overall hemodynamic performance based on the variables considered. The results indicate that integrating helical shape into bypass grafts improves hemodynamic performance, reduces intimal hyperplasia risk, and may prolong graft durability. These findings provide valuable insights and suggestions for enhancing AVG designs to support patient outcomes. Full article

Strategic mergers and acquisitions (M&A) can support sustainable business models by enabling firms to adapt their capabilities and competitive positions as conditions change. This study examines how target listing status (public vs. private) and acquirer size shape short-term shareholder wealth in Korean SMEs (Small- and medium-sized enterprise), and links announcement reactions to subsequent operating outcomes. Using an event study and multivariate regressions on 155 M&A announcements by KOSDAQ-listed SMEs (Korean Securities Dealers Automated Quotations) (2016–2020), we find that smaller acquirers earn significantly higher announcement-period cumulative abnormal returns (CAR)—i.e., smaller firm size is positively associated with superior market-adjusted performance around M&A events. Although acquisitions of privately held targets and diversifying deals show higher unadjusted means, their effects become statistically insignificant once firm fundamentals and size are controlled for. To connect M&A strategy with business-model sustainability, we operationalize sustainability as the alignment between short-term market expectations (CAR) and realized operating performance over 1–2 years, measured by return on operating cash flow (ROCF); medium-term checks indicate that the short-run “size effect” attenuates, underscoring the role of execution and scale in longer-run outcomes. Overall, the evidence highlights the primacy of firm-specific fundamentals, strategic fit, and integration capacity in guiding M&A decisions that advance both near-term performance and longer-term resilience. The Korean SME setting—marked by concentrated ownership, resource constraints, and a chaebol-influenced market and policy environment—provides a stringent context for these tests. Full article

Environmental, Social, and Governance (ESG) communications have proliferated across Fortune 500 companies, yet no validated frameworks exist for systematically distinguishing authentic from superficial positioning. This study develops and validates the Dynamic Authenticity Evaluation Model (DAEM), measuring three interactive dimensions of ESG communication authenticity: operational alignment, temporal consistency, and communication specificity. Through dual-evaluator protocols applied to eight mega-cap companies, DAEM achieves excellent inter-rater reliability (ICC = 0.85; Krippendorff’s α = 0.83). An event study analysis across sixteen major ESG announcements reveals no significant correlation between communication authenticity and abnormal stock returns (r = 0.289; p = 0.491), with effects being bounded below ±0.30% cumulative abnormal returns through equivalence testing. Preliminary stakeholder analysis suggests differential authenticity sensitivity, with employee engagement showing a stronger association with DAEM scores (r = 0.423) than market reactions (r = 0.289). Results indicate that authentic ESG communications influence non-market stakeholders more than short-term stock prices, suggesting that market value creation requires operational rather than symbolic approaches, while authentic communication remains important for stakeholder relationship management. Full article

CblC deficiency is the most common intracellular disorder of vitamin B12 metabolism. Expanded newborn screening (NBS) plays a key role in early diagnosis, allowing timely treatment and preventing serious complications. However, traditional first-tier markers—such as propionylcarnitine (C3) and its ratios with other metabolites (e.g., methionine, carnitine, and acetylcarnitine)—have limited sensitivity, particularly for mild forms, leading to missed or delayed diagnoses. In this study, we analyzed data from the NBS Center of the Lazio region (Italy) and identified nine newborns with confirmed CblC deficiency. All were recalled due to abnormalities in C3 or related ratios, along with elevated methylmalonic acid (MMA) levels. Notably, three infants had completely normal C3 levels and ratios during the second screening test, yet they showed MMA levels above the cut-off value (2 µmol/L), enabling a diagnosis of otherwise undetectable mild CblC cases. Our center regularly measures MMA in dried blood spots, even when first-tier markers return to normal on the second sample. This approach allows for early diagnosis and immediate treatment with hydroxocobalamin in patients with mild CblC deficiency, resulting in early intervention, effective metabolic control, and, based on current follow-up, normal neurodevelopmental outcomes. Our findings highlight the essential role of second-tier MMA testing in improving the detection of mild CblC deficiency during NBS. Full article

Abnormal CO gas concentration is one of the common problems in coal mine safety production. In view of the phenomenon of CO overrun in the working face, this paper takes the fully mechanized discharge working face of Zhaoxian Mine as the research object, analyzes the occurrence of primary coal seam gas through the coal sample tank analysis experiment and the indoor crushing experiment, and explores the source of CO in the fully mechanized working face. According to the calculation model, the predicted value of CO concentration at the return air corner of the working face was calculated and, combined with the gas data of the working face monitored on site, it was proven that the CO concentration of the working face was in the normal range. This study found that the oxidation of residual coal in the goaf and the generation of CO during the mining process were the main reasons for the high CO concentration in the working face, rather than the occurrence of raw coal. This study reduces the interference of CO concentration on the determination of coal spontaneous combustion, prevents the misjudgment of coal spontaneous combustion, ensures the safe production of the Zhaoxian Coal Mine, provides data and theoretical support for the subsequent establishment of the CO prevention and control system of the working face, and provides a solution and technical reference for the CO overrun phenomenon in the working face of other high-gas mines. Full article

Background: Metabolic memory refers to the long-term adverse effects of short-term disturbances in glucose metabolism. Recent evidence indicates that hyperglycemia-induced metabolic memory contributes to sustained cellular damage even after glycemic control, driven by increased production of reactive oxygen species (ROS), activation of inflammatory pathways, and accumulation of advanced glycation end products (AGEs). Although well characterized in endothelial and smooth muscle cells, this phenomenon may also occur in other cell types, including glial cells. Objective: This study aimed to evaluate the persistence of high-glucose (HG)-induced alterations after returning to normal glucose (NG) conditions in primary mixed glial cell (MGC) cultures. Methods: Primary MGCs were obtained from neonatal Wistar rat pups and cultured under three conditions for 21 days: NG (5.5 mM glucose), HG (25 mM glucose), and HG-NG (14 days in HG followed by 7 days in NG). Cell proliferation, apoptosis, ROS production, lipid peroxidation, mitochondrial activity, TNF-α, IL-6, and AGE formation were assessed. Results: MGCs cultured under HG and HG-NG conditions exhibited reduced proliferation without increased apoptosis. Both HG and HG-NG conditions promoted ROS overproduction accompanied by reduced mitochondrial activity, whereas only HG increased lipid peroxidation. Notably, TNF-α and AGE levels were elevated in both HG and HG-NG conditions, while IL-6 production decreased exclusively in HG-NG. Conclusions: These findings demonstrate the persistence of deleterious effects induced by HG in MGCs, even after restoration to NG conditions. Full article

This study challenges the conventional wisdom that investor reactions to Environmental, Social, and Governance (ESG) information are primarily driven by disclosure sentiment. We propose and test an alternative hypothesis: that for investors navigating information-rich environments, the frequency of ESG disclosures can serve as a more potent signal of a firm’s underlying commitment and risk profile than the sentiment of the announcements themselves. Focusing on Taiwan’s capital market—a globally pivotal technology hub—we analyze 2576 firm-initiated ESG events from 2014 to 2023 using an event study methodology. We innovate by employing a BERT-based NLP model, specifically fine-tuned for Traditional Chinese, to disentangle the effects of disclosure frequency from sentiment. Our results reveal that announcement frequency is a more robust predictor of abnormal returns than sentiment, but its effect is highly contingent on the ESG pillar. A higher frequency of negative Social (S) and Governance (G) disclosures incurs a significant market penalty, whereas frequent proactive Environmental (E) disclosures are rewarded. These findings establish a “disclosure frequency premium/penalty” and offer critical, nuanced insights for corporate strategy and sustainable investment. By demonstrating how communication patterns shape market perceptions, this research directly informs UN SDG 12 (Responsible Production) and SDG 16 (Strong Institutions). Full article

Background: Cervical cancer ranks among the most prevalent tumors in low-income countries, with the Pap test as one of the primary screening tools. The Pap smear detects abnormal cells, the CLART test identifies specific HPV genotypes, and HPV self-sampling allows for self-collected HPV testing. This study aimed to evaluate the feasibility of the first smartphone-based health device for home-collection HPV testing. Methods: Enrolled patients during the gynecological examination underwent three different samplings: Pap smear, HPV DNA genotyping test CLART, and vaginal HPV-Selfy swab. Each patient received a kit including an activation code, vaginal swab, and instructions. After performing the self-sample, patients returned the kit to our laboratory. Both the samples collected by the gynecologist and those collected by the patients themselves were analyzed. Results: A total of 277 patients were enrolled, with 226 self-collected swabs received for analysis. The assay yielded valid results for both self-collected and clinician-collected swabs in 190 patients. When comparing these results with paired clinician-taken vaginal swabs, we observed an agreement of 95.2% (Cohen’s Kappa: 0.845). We report an agreement of 93.7% (Cohen’s Kappa: 0.798). Conclusions: The study demonstrated the feasibility of HPV-Selfy as a complementary tool in cervical cancer screening, especially where adherence to traditional surveillance is low. Full article

Prior research often portrays Corporate Social Responsibility (CSR) as a coercive institutional force compelling firms to passively conform for legitimacy. More recent studies, however, suggest firms actively pursue CSR to gain sustainable competitive advantages. Yet, how and when CSR buffers firms against adverse shocks of crises remains insufficiently understood. This study addresses this gap by using multiple regression analysis to examine the buffering effects of CSR investments during the COVID-19 crisis, which severely disrupted capital markets and firm valuation. Drawing on signaling theory and CSR literature, we analyze the stock market performance of China’s A-share listed firms using a sample of 2577 observations as of the end of 2019. Results indicate that firms with higher CSR investments experienced significantly greater cumulative abnormal returns during the pandemic. Moreover, the buffering effect is amplified among firms with higher debt burdens, greater financing constraints, and those operating in regions with stronger social trust and more severe COVID-19 impact. These findings are robust across multiple robustness checks. This study highlights the strategic value of CSR as a resilience mechanism during crises and supports a more proactive view of CSR engagement for sustainable development, complementing the traditional legitimacy-focused perspective in existing literature. Full article

A real-time structural health monitoring (SHM) system of an airplane composite wing with adjustable damage is reported, where testing under realistic flight conditions is carried out in the controllable and repeatable environment of an industrial wind tunnel. An FBG-based sensing array monitors a debonded region, whose compromised structural strength is regained by a set of lockable fasteners. Damage tunability is achieved by loosening some of or all these fasteners. Real-time analysis of the data collected involves Principal Component Analysis, followed by Hotelling’s T-squared and Q measures. With previously set criteria, real-time data collection and processing software can declare the structural health status as normal or abnormal. During testing, the system using the Q measure successfully identified the initiation of the damage and its extent, while the T-squared one returned limited outcomes. Full article

Past studies have observed that the low (high) accrual portfolio in the accrual anomaly consists of firms with high (low) credit risk, and have suggested that the abnormal return in the accrual anomaly arises from buying (selling) stocks with high (low) credit risk. In this paper, I first investigate whether the low accrual portfolio is indeed dominated by firms with higher credit risk. I find that this claim is not necessarily true. Next, I regress the abnormal return on both the level of accrual and credit risk. The regression is repeated using both decile ranking and actual values. In both cases, I find that the level of accrual is always statistically significant and negative. Finally, I investigate the claim that the abnormal return in the accrual anomaly is due to taking a long (short) position in stocks with high (low) credit risk. In each year, to control for credit risk, I first rank all firms by both their level of accrual and credit risk. The ranking for accrual and credit risk are independently determined. I require that in each year, the long position (in the low accrual decile) and short position (in high accrual decile) are equally weighted within each credit risk decile. After controlling for credit risk, I find that the abnormal return from Sloan’s accrual trading strategy is still positive, statistically significant and economically significant. I conclude that the accrual anomaly cannot be explained by credit risk. All findings in this paper are robust as to whether credit risk is measured using Altman’s z-score or the Standard & Poor’s credit rating. Full article