Search

Political insider trading has brought substantial attention to ethical considerations in the academic literature. While the Stop Trading on Congressional Knowledge (STOCK) Act prohibits members of Congress and their staff from leveraging non-public information to make investment decisions, political insider trading still prevails. We discuss political ethics and social contract theory to re-engage the debate on whether political insider trading is

Recent studies highlight positive effect of political connections on firm performance and stock returns. This paper shows that the positive effect of political connections on the cross-sectional stock returns disappears in the weak presidency period, defined as the last two years before the presidential party change, or period of low job approval ratings. The extent of the presidential party?s control over the Congress does not affect our main result. The result is driven by small firms, who typically do not have financial resources to hedge away political risks, and by the firms located in the states where residents more strongly support the president. Additional test suggests that the industries that rely on heavy government expenditure use a variety of political strategies to maintain the value of their political capital even during the weak presidency period.

We present evidence that the negative impact of CEO short-termism on firm value can be attributed to a sub-optimal exercise of real options. Accordingly, the value relevance of firms’ real options portfolios is maximized in the absence of CEO temporal myopia. Moreover, the impact of real options on firms’ stock returns’ idiosyncratic characteristics is more pronounced when CEOs’ decision horizons are longer, in line with the view that enhanced operating flexibility from longer decision horizons can amplify the convexity of real options’ payoffs. These findings have important implications regarding the impact of CEO career horizons on corporate strategies and board decisions related to CEO incentives and succession.

This study examines the contribution of CEO unobserved heterogeneity to CEO inside debt compensation. Using a three-way fixed effects model, we find that CEO fixed effects explain a majority of the variation in inside debt. The CEO inside debt compensation explained by CEO fixed effects is also positively associated with firm performance, while the distance from the predicted optimal inside debt is unrelated to firm performance. Further, firms appear to adjust inside debt toward their predicted optimums by minimizing year-over-year deviations. Collectively, our findings indicate that inside debt results from optimal-contracting and help align the interests of CEOs with those of debtholders.

We define areas with strong geographic ties to powerful politicians as politically vibrant and show that they are characterized by greater value‐relevant information generation and symptomatic of equity market segmentation. Political vibrancy entails greater levels of local bias and local comovement and has two important return predictability implications. First, it enhances local institutions’ informational advantages; their trades’ ability to forecast local stock returns exceeds that of nonlocal institutions. Second, in support of the view that information diffuses slowly into prices, stock returns of firms from politically vibrant areas predict returns of similar firms in other areas.

The gene

The gene whcE of Corynebacterium glutamicum plays a positive role in oxidative stress responses and the WhcE protein interacts with SpiE. By utilizing 2D-PAGE analysis, we identified the otsB gene to be under the control of whcE. The transcription of otsB, encoding trehalose 6-phosphatase, was stimulated by oxidative stress, and whcE and spiE were involved in diamide-mediated transcriptional stimulation. The ΔotsB strain was created and found to be sensitive to the thiol-specific oxidant diamide, suggesting a role of the gene in stress responses. Genes located upstream of otsB, such as NCgl2534 and otsA, formed an operon and purified WhcE was able to bind to the promoter region of the operon (PNCgl2534), but the binding was only possible in the presence of the oxidant diamide. In addition, the transcriptional activation of PNCgl2534 by WhcE was demonstrated in in vivo assays and the transcription was stimulated in cells exposed to the oxidant diamide. These findings indicate that WhcE is a transcriptional activator, and otsB, which is involved in trehalose biosynthesis, has a role in oxidative stress responses in C. glutamicum .

AIM To compare late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites with respect to soft tissue levels, esthetics, and patient-reported outcomes. MATERIALS AND METHODS Sixteen patients were randomly allocated to groups LP/ARP (n = 9) or EP (n = 7). Group LP/ARP received ARP using deproteinized bovine bone mineral containing 10% collagen and a native bilayer collagen membrane, and group EP received only extraction. Implant placement was performed 4-8 weeks post-extraction in group EP and 4 months post-alveolar ridge preservation in group LP/ARP. The soft tissue levels, pink/white esthetic scores, and periodontal parameters were evaluated 1-year post-loading. Patient's discomfort level was evaluated at the time of extraction/ARP and implant placement. RESULTS No implant failure or biologic complications occurred. There was no statistically significant difference in the median change of the midfacial mucosal margin (0.03 for group LP/ARP, -0.19 mm for group EP) and the mesial/distal papilla (0.62/0.25 mm for group LP/ARP, 0.29/-0.5 mm for group EP), pink/white esthetic scores, periodontal parameters, and patient's discomfort between the two groups. CONCLUSION Both implant placement protocols led to comparable outcomes in soft tissue levels, periodontal parameters, and patient's discomfort level.

The average investor who lives in a state with relatively higher alcohol consumption is more likely to buy and sell lottery-type stocks and to trade more often. Both of these activities entail sensation seeking; correspondingly, we find that speculative investment behavior is correlated with alcohol consumption only in states with lotteries and where a local tendency for sensation seeking behavior has not been diluted by an influx of migrants from other states where alcohol consumption is low. Most importantly, our results suggest that alcohol consumption does not per se drive a preference for investment gambles, but rather portrays the type of local culture in which the speculative investing occurs.

Using data on job approval ratings of governors, U.S. senators, and the president, we find that firms located in states with high approval ratings outperform firms located in states with low approval ratings by .64% per month. Furthermore, this relationship is stronger when investors are actively involved in politics, when local politicians are closer to the center of political power, for small firms that have a larger proportion of local investors, and for financially strong areas where investors are ready to execute investments in local stocks. Overall, our study shows that investors’ political sentiment is important in determining stock returns.

Purpose The aim of this retrospective study was to determine the prevalence of early implant failure using a single implant system and to identify the factors contributing to early implant failure. Methods Patients who received implant treatment with a single implant system (Luna®, Shinhung, Seoul, Korea) at Dankook University Dental Hospital from 2015 to 2017 were enrolled. The following data were collected for analysis: sex and age of the patient, seniority of the surgeon, diameter and length of the implant, position in the dental arch, access approach for sinus-floor elevation, and type of guided bone regeneration (GBR) procedure. The effect of each predictor was evaluated using the crude hazard ratio and the adjusted hazard ratio (aHR) in univariate and multivariate Cox regression analyses, respectively. Results This study analyzed 1,031 implants in 409 patients, who comprised 169 females and 240 males with a median age of 54 years (interquartile range [IQR], 47–61 years) and were followed up for a median of 7.2 months (IQR, 5.6–9.9 months) after implant placement. Thirty-five implants were removed prior to final prosthesis delivery, and the cumulative survival rate in the early phase at the implant level was 95.6%. Multivariate regression analysis revealed that seniority of the surgeon (residents: aHR=2.86; 95% confidence interval [CI], 1.37–5.94) and the jaw in which the implant was placed (mandible: aHR=2.31; 95% CI, 1.12–4.76) exerted statistically significant effects on early implant failure after adjusting for sex, age, dimensions of the implant, and type of GBR procedure (preoperative and/or simultaneous) (P, Graphical Abstract

We document significant heterogeneity in the relation between chief executive officer (CEO) equity incentives and firm value using quantile regression. We show that CEO delta is more effective in the presence of ample investment opportunities, while CEO vega is more beneficial for firms lacking investment opportunities. Further, Tobin's Q increases in CEO delta for more risk‐tolerant firms but increases in CEO vega for more risk‐averse firms. We also observe that higher monitoring intensity after the Sarbanes‐Oxley Act reduces CEO delta's role in compensation. Risk aversion alters the optimal incentive‐value relation, and the nature of this relation also depends on the level of Tobin's Q.

Eu1-xSrxAl2O4 (0.0 ≤ x ≤ 1.0) materials were successfully synthesized and characterized. Rietveld refinements revealed that the monoclinic phase with the P21 (No. 4) space group is thermodynamically stable within the wide EuO-SrO-AlO solid-solution range. Spectroscopic refinements using infrared (IR), Raman, and X-ray photoelectron spectroscopy (XPS) indicated that the vibrational modes are somewhat chemically shifted, most likely because of the difference in reduced mass (μ) between Eu‒O and Sr–O bond. Based on the binding energies of the reference compounds (Eu2O3 and EuCl2), the predominant Eu2+ species are partially oxidized to Eu3+ species in the near-surface region. The band-gap energies (Eg) of the Eu1-xSrxAl2O4 (x = 0.0, 0.5, and 1.0) materials were determined from the Kubelka-Munk transformation of the diffuse reflectance spectra (DRS) to be 2.56, 2.59, and 4.23 eV, respectively, in agreement with previously reported values determined by theoretical band calculation. The photoluminescence (PL) and LED-emission results revealed that the luminous efficiency of the Eu0.3Sr0.7Al2O4 was approximately 2.5 times higher than that of EuAl2O4 phosphor. Using Williamson−Hall (W−H) method, the determined structural strains of phosphors revealed that the compressive strain plays an important role in the enhanced PL intensity ofthese phosphors. These materials provide a platform for developing new phosphors for application in solid-state lighting.

The N3–-substituted Li2MSiO4:Eu2+ (M = Ca, Sr, and Ba) phosphors were systematically prepared and analyzed. Secondary-ion mass spectroscopy measurements revealed that the average N3– contents are 0.003 for Ca, 0.009 for Sr, and 0.032 for Ba. Furthermore, the N3– incorporation in the host lattices was corroborated by infrared and X-ray photoelectron spectroscopies. From the photoluminescence spectra of Li2MSiO4:Eu2+ (M = Ca, Sr, and Ba) phosphors before and after N3– doping, it was verified that the enhanced emission intensity of the phosphors is most likely due to the N3– doping. In Li2MSiO4:Eu2+ (M = Ca, Sr, and Ba) phosphors, the maximum wavelengths of the emission band were red-shifted in the order Ca < Ba < Sr, which is not consistent with the trend of crystal field splitting: Ba < Sr < Ca. This discrepancy was clearly explained by electron–electron repulsions among polyhedra, LiO4–MOn, SiO4–MOn, and MOn–M’On associated with structural difference in the host lattices. Therefore, the energy levels associated with the 4f65d energy levels of Eu2+ are definitely established in the following order: Li2CaSiO4:Eu2+ > Li2BaSiO4:Eu2+ > Li2SrSiO4:Eu2+. Furthermore, using the Williamson–Hall (W–H) method, the determined structural strains of Li2MSiO4:Eu2+ (M = Ca, Sr, and Ba) phosphors revealed that the increased compressive strain after N3– doping induces the enhanced emission intensity of these phosphors. White light-emitting diodes made by three N3–-doped phosphors and a 365 nm emitting InGaN chip showed the (0.333, 0.373) color coordinate and high color-rendering index (Ra = 83). These phosphor materials may provide a platform for development of new efficient phosphors in solid-state lighting field.

Background To evaluate gingival inflammation from fixed-dose combinations of vitamin C, vitamin E, lysozyme and carbazochrome (CELC) in the treatment of chronic periodontitis following scaling and root planing. Methods One hundred patients were randomly assigned to receive CELC (test) or placebo (control) for the first 4 weeks at a 1:1 ratio, and both groups received CELC for the remaining 4 weeks. Primary outcome was the mean change in the gingival index (GI) after 4 weeks. Secondary outcomes included mean change in GI after 8 weeks and plaque index, probing depth, clinical attachment level, and VAS at 4 weeks and 8 weeks. Results Ninety-three patients completed the study. The GI in the test group significantly decreased after 4 weeks (p

We examine whether the proportion of CEO inside debt holdings (pension and deferred compensation) to stock holdings benefit both shareholders and debtholders by relating CEO inside debt to a firm’s dividend payout policies. Based on the positive association of CEO inside debt and the propensity and the size of the dividend payout, we find that firms paying their CEOs with large inside debt present the lower cost of debt and default risk, and these benefits transfer to better firm performance and valuation. Moreover, we find that CEO inside debt is related to superior firm performance only in dividend-paying firms. Dividends tend to increase when firms with high agency costs of equity use inside debt. We conclude that dividends serve as a channel through which CEO inside debt compensation mitigates both agency costs of debt and agency costs of equity.

Self-emitting blue and red EuOX (X = F, Cl, Br, and I) were successfully synthesized and characterized. Far-infrared and Raman measurements revealed that the vibration modes prominently reflected the Eu-O and Eu-X bond characters of these materials. X-ray photoelectron spectroscopy (XPS) of the red-emitting EuOX compounds showed that Eu exclusively existed as Eu3+, while in the blue-emitting EuOX, a mixed Eu3+/Eu2+ state was observed. For the red-emitting EuOX (X = F, Cl, and Br), the maximum wavelengths of the charge-transfer (CT) bands were red-shifted: F → Cl → Br (282, 320, and 330 nm for F, Cl, and Br, respectively). Using one-electron spin-polarized band structure calculations, it was verified that the red-shift of the CT energy from F to Br in EuOX was mainly due to the relative positions of the halogen orbital energies being gradually increased, following the trend in their electronegativity. For the blue-emitting EuOX (X = Cl, Br, and I), the emission band maxima were red-shifted from Cl to I (409, 414, and 432 nm for Cl, Br, and I, respectively), which was quite opposite to the trend predicted based on the spectrochemical series in crystal field theory, which was in good agreement with the previous results of the calculated 5d → 4f transition energies of the Eu2+ activator based on the crystal field theory. Through photoluminescence, UV-visible absorbance, and XPS, it was elucidated that the red emission due to Eu3+ was strongly masked by the intensified blue emission associated with the small amount of Eu2+ in the blue-emitting EuOX (X = Cl, Br, and I). These materials may provide a platform for modeling new phosphors for application in solid-state lighting.

The aim of the present study was to re-visit the gingival dimension using digital scanning in a healthy Korean population. Forty-eight periodontally healthy volunteers (38 males and 10 females, mean age: 24.3 ± 2.2 years) were included. The mucogingival junction was highlighted using 2.5% diluted iodine solution. Then, the facial gingiva and mucosa of both jaws were digitally scanned using an intraoral digital scanner. Using computer software and periodontal probing, the heights and areas of keratinized gingiva (KG) and attached gingiva (AG) were measured. Similar distribution patterns in the gingival heights were noted in the maxilla and mandible. The maxilla showed substantially greater gingival values than the mandible. The heights of the KG and AG were notably smaller on the mandibular first premolar (2.37 mm and 1.07 mm, median value) and second molar (3.28 mm and 1.78 mm) than on the other teeth. The area of the KG was the largest in the canine (63.74 mm2 and 46.85 mm2) and first molar (64.14 mm2 and 58.82 mm2) in each jaw. Mandibular first and second molars, mandibular canine, and maxillary canine showed the highest value of the area under the receiver operation characteristics curve (&gt, 0.7) for differentiating between males and females. The gingival dimensions recorded using intraoral scanner demonstrated similar distribution patterns as in previous studies.

Information regarding profilometric changes at a soft tissue level following implant placement with different protocols is insufficient. Therefore, this study aimed to comparatively investigate the profilometric tissue changes with respect to late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites. Sixteen patients were randomly assigned to the following groups: implant placement 4 months post-ARP (group LP/ARP) and tooth extraction and implant placement 4–8 weeks post-extraction (group EP). Dental impressions were obtained immediately after final prosthesis insertion and at 3, 6, and 12 months. At the time of implant placement, bone augmentation was performed in the majority of the patients. Profilometric changes of the tissue contour were minimal between the final prosthesis insertion and 12 months in the mid-facial area (0.04–0.35 mm in group LP/ARP, 0.04–0.19 mm in group EP). The overall tissue volume increased in both groups (1.70 mm3 in group LP/ARP, 0.96 mm3 in group EP). In conclusion, LP/ARP and EP led to similar stability of the peri-implant tissue contour between the final prosthesis insertion and at 12 months. Moreover, the change of peri-implant tissue on the soft tissue level was minimal in both modalities.

Objective To explore how video learning strategies influence students' Flipped learning (FL) achievement, deep approach to learning (DAL) and lifelong learning (LL) orientations and how DAL and LL can be promoted. Methods Data were collected from 65 dental students enrolled in a 21-week clinical periodontology course. Partial least squares structural equation modeling was conducted to investigate factors and pathways affecting FL achievement, DAL, and LL. Results FL achievement was predicted by repeated and in-advance video learning strategies. In-advance, meticulous, and expanded video learning strategies directly influenced DAL, and indirectly influenced LL via DAL. LL was not affected by any of the video learning strategies but by the DAL. Conclusion This study implies that mere implementation of FL may not guarantee more developed DAL and enhanced LL. Redesigning a course with FL should entail revisiting and revising student assessment. LL is an inclusive approach that requires the long-term cultivation of meaning, experience, insight, learning, and practice.

We examine senators’ electronically filed stock transactions between 2012 and 2019 to assess the extent of politician’s insider trading. Our results suggest that senators use inside political information when investing and earn significant market-adjusted returns. To extend traditional return-based methods, we propose a new comprehensive approach based on abnormal idiosyncratic volatility (AIV), which captures the degree of information asymmetry around their trading dates. We document that senator trades are associated with substantially high levels of AIV, suggesting that they represent only a tip of the iceberg, since the mass of unfiled transactions using the same inside information remains undetected.

Excessive gingival display (EGD) is a common esthetic concern. Lip repositioning surgery (LRS) was introduced as one of the treatment options to manage EGD. LRS can be used for skeletally and/or muscularly induced EGD. The present case series applied LRS using an Er,Cr:YSGG laser to treat 24 patients with minor vertical maxillary overgrowth or a hypermobile lip. At 6 months, the gingival display had decreased by 3.79 ± 1.59 mm (mean ± standard deviation), and the visible lip body when smiling had increased by 1.23 ± 0.74 mm. A questionnaire revealed that the level of satisfaction with the smile increased among the patients and that they had a positive attitude toward Er,Cr:YSGG laser-assisted LRS.

Purpose This study investigated whether the placement of ribose cross-linked collagen (RCLC) membranes without primary soft tissue closure predictably resulted in sufficient alveolar ridge preservation in contained and non-contained extraction sockets. Methods Membranes were positioned across extraction sockets, undermining full-thickness flaps, and the gingival margins were fixed by double-interrupted sutures without crossed horizontal mattress sutures for 1 week. In non-contained sockets, a bone substitute was used to support the membrane within the bony envelope. Radiographs and clinical images obtained 4 months later were analyzed by ImageJ software using non-parametric tests. Results In 18 patients, 20 extraction sockets healed uneventfully and all sites received standard-diameter implants (4.1, 4.8, or 5.0 mm) without additional bone augmentation. Soft tissues and the muco-gingival border were well maintained. A retrospective analysis of X-rays and clinical photographs showed non-significant shrinkage in the vertical and horizontal dimensions (P=0.575 and P=0.444, respectively). The new bone contained vital bone cells embedded in mineralized tissues. Conclusions Within the limitations of this pilot study, open healing of RCLC membranes may result in sufficient bone volume for implant placement without additional bone augmentation in contained and non-contained extraction sockets., Graphical Abstract