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In this paper, we analyze share repurchase rumors comparing them with share repurchase announcements in the period from 1999 to 2010. We found the empirical evidence that share repurchase rumors exhibit positive signaling effect comparable to the announcement effect of share repurchases. We then extend the existing theory of rumors (information transmission) by introducing the concept of publication status. Publication of rumors changes their status from private to public information. This transition results in smaller abnormal returns and acceleration in uninformed liquidity trading. In addition, empirical evidence suggests that the stock market differentiates information from different publication sources, e.g., major news providers versus self reporting company presses.

비대면 교육 서비스의 효과를 높이기 위해서는 표준화된 웹 환경 제공, 정보보안 서비스 강화, 온라인 환경 가이드 개선, 교육 서비스 홍보, 신청, 프로그램 이용, 성과 확인까지 이용자와 상호작용 할 수 있는 플랫폼 확보 등과 같은 문제를 해결해야 한다. 재택근무나 원격교육 등 현실적으로 비대면 서비스의 핵심 적인 기술은 바로 화상회의라 할 수 있다. 화상회의는 비디오와 오디오 스트리밍 기술, 멀티미디어 생성 및 제어 기술, 효율적인 전송을 위한 압축기술, 이를 P2P(Peer-to-Peer) 혹은 중계 서버를 통해 실시간으 로 전달하는 전송기술 등 다양한 요소들이 포함되어 있다. 본 논문은 웹 기반 화상회의 시스템에서 종단 간 암호화 서비스 (E2EE: End-to-end Encryption)를 제공하기 위한 서비스 구조를 제안하였다.

In order to increase the effectiveness of non-face-to-face education services, problems such as providing a standardized web environment, strengthening information security services, improving online environment guides, and securing a platform for interaction with users must be solved. The core technology of non-face-to-face services such as telecommuting or distance education is video conferencing. Video conferencing includes various elements such as video and audio streaming technology, multimedia creation and control technology, compression technology for efficient transmission, and transmission technology that delivers it in real time through P2P (Peer-to-Peer) or a relay server. In this paper, a service structure is proposed to provide an end-to-end encryption service in a web-based video conferencing system.

In this study, we explore a condition where corporate debt can be strategically used in the stock market by governing its interpretations from investors. To disentangle the performance implications of corporate debt, we pay attention to the signaling aspect of debt financing. Acknowledging that investors can interpret the value of a firm with the level of debt, we postulate that debt can convey differentiated signals (i.e. driver vs. distress). In addition, we argue that the bifurcated role of debt can be moderated by marketing activities, which can affect the stakeholders’ interpretations. This idea is empirically examined in a population of SMEs (Small- and Medium-sized Enterprises). Using COMPUSTAT database of 2,174 U.S. public firms ranging from 1982 to 2010, we find resource-independent debt (called idiosyncratic debt) has bifurcated impacts on Buy-and-Hold Abnormal Returns (BHARs) and the marketing moderation of such relationship is also bifurcated.

Previous studies present the mixed results on online reputation mechanism. In this study, we have found that an approach based on Bayesian statistics can explain most results of previous studies which are conflicting with each others. With this model, we explain why negative ratings have more significant marginal impacts on sellers' reputation than positive ones do. Furthermore, we even show why the feedbacks with a few negative ratings may increase the value of the item and final prices by confirming buyers' prior beliefs on the sellers' reputation much more than those without negative ratings. Also, we explain why there are not many negative ratings. Even though some studies suggest this because of generosity of users, our model shows that the reason is that the existence of FS itself prevents bad sellers from participating to the market as a signal itself. Even further, we show how this extreme tendency of positive ratings gets even stronger as markets evolve. Finally, to validate our analytical results, we examine the previous studies and see what factors effect the outcomes of their analyses.

Massive multiple-input multiple-output can significantly increase the system capacity by allowing vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) networks to share the radio resource pool, if the inter-network interference is constrained. However, in order to control the inter-network interference, it is necessary to exchange channel state information (CSI) between the V2I and V2V networks, which requires a huge amount of signaling resources. This paper proposes an one-bit signaling-based interference management scheme to reduce the signaling overhead while controlling the interference from the V2V network to the V2I network.

This study investigated changes in gene expression by dietary fat source, i.e., beef tallow, soybean oil, olive oil, andcoconut oil (each 3% in feed), in both male and female growing-finishing pigs. Real-time PCR was conducted onseven genes (insulin receptor; INSR, insulin receptor substrate; IRS, phosphatidylinositol (3,4,5)-triphosphate; PIP3,3-phosphoinositide-dependent protein kinase-1; PDK1, protein kinase B; Akt, forkhead box protein O1; FOXO1 andcGMP-inhibited 3’, 5’-cyclic phosphodiesterase; PDE3) located upstream of the insulin signaling pathway in thelongissimus dorsi muscle (LM) of pigs. The INSR, IRS, PIP3, and PDE3 genes showed significantly differentialexpression in barrow pigs. Expression of the PIP3 and FOXO1 genes was significantly different among the fourdietary groups in gilt pigs. In particular, the PIP3 gene showed the opposite expression pattern between barrowand gilt pigs. These results show that dietary fat source affected patterns of gene expression according to animalgender. Further, the results indicate that the type of dietary fat affects insulin signaling-related gene expression in theLM of pigs. These results can be applied to livestock production by promoting the use of discriminatory feed supplies.

We investigated the effects of regular treadmill exercise for 6 weeks on NGF, tyrosine kinase receptor A(TrkA), p75 receptor, phosphatidylinositol 3-kinase(PI3-K), mitogen-activated protein kinase(MAPK)/extracellular signal-regulated kinase 1/2(Erk1/2), cyclic AMP response element-binding protein(CREB), and caspase-3 protein levels in the hippocampus of diabetic rats; we also assessed cell survival and cognitive function. Forty male Sprague-Dawley(SD) rats were divided into four groups: (1) normal control group(NCG: n ＝ 10); (2) normal exercise group(NEG: n ＝ 10); (3) diabetes control group(DCG: n ＝ 10), and (4) diabetes exercise group(DEG: n ＝ 10). Diabetes was induced by injecting streptozotocin(STZ; 55 mg/kg dissolved in 0.05 M citrate buffer, pH 4.5, i.p.) into rats. Rats were subjected to treadmill exercise for 5 days a week over 6 weeks, and the speed of the treadmill was gradually increased. In a passive avoidance test, the retention latency in the DCG was significantly shorter than that in the DEG(p < 0.05). Increased BrdU-labeled cells(p < 0.001) and significant increases in NGF and TrkA protein levels were observed in the hippocampal dentate gyrus in the NEG and DEG(p < 0.001 and p < 0.01, respectively). The p75 receptor protein level significantly increased in the NEG but decreased in the DCG(p < 0.001). The p-PI3-K and t-CREB protein levels significantly increased in the NEG(p < 0.001 and p < 0.05, respectively), whereas t-Erk1/2 significantly decreased in the DCG(p < 0.01, p < 0.01, respectively). p-Erk1/2 and p-CREB protein levels significantly increased in the NEG and DEG(p < 0.001, p < 0.001, and p < 0.01, respectively). Caspase-3 protein levels significantly increased in the DCG(p < 0.001). These results show that treadmill exercise improves cognitive function, increases the number of BrdU-labeled cells, and increases NGF levels, by the activation of the MAPK/Erk1/2 signaling pathway in the hippocampus of diabetic rats.

Deoxynivalenol (DON) is the most common mycotoxin contaminant of food or feed worldwide and causes disease in animals. Lauric acid (LA) is a medium-chain fatty acid useful for barrier functions such as antimicrobial activity in the intestine of monogastric animals. However, the molecular mechanisms by which lauric acid exerts its effects on the deoxynivalenolexposed small intestine have not been studied. We used an intestinal porcine epithelial cell line (IPEC-J2) as an in vitro model to explore the molecular mechanism of lauric acid in alleviating deoxynivalenol-induced damage. We found that lauric acid reversed deoxynivalenol-induced reduction in cell viability. Our quantitative real-time polymerase chain reaction results indicated that lauric acid alleviated deoxynivalenol-induced apoptosis through Annexin-V. Additionally, immunofluorescence and Western blotting showed that lauric acid attenuated deoxynivalenol-induced forkhead box O3 (FOXO3a) translocation into the nucleus. These results suggest that lauric acid attenuates forkhead box O3 translocation in the small intestine damaged by deoxynivalenol, thereby reducing apoptosis. In conclusion, this study found that lauric acid alleviates deoxynivalenol-induced damage in intestinal porcine epithelial cell line through various molecular mechanisms.

Background: This study was performed to investigate the impact of exogenous ghrelin on the pancreatic α-amylase outputs and responses of pancreatic proteins to ghrelin that may relate to pancreatic exocrine. Methods: Sprague-Dawley male rats (9 weeks old, 300 ± 10 g) were injected with ghrelin via intraperitoneal (i.p.) infusion at dosage of 0, 0.1, 1.0 and 10.0 μg/kg body weight (BW), respectively. The plasma ghrelin and cholecystokinin (CCK) level were determined using enzyme immunoassay kit; the mRNA expression of ghrelin receptor (GHSR-1α) and growth hormone (GH) receptor were assessed by reverse transcription PCR; the expressions of pancreatic α-amylase activity, extracellular-signal-regulated kinases (ERK), phosphorylated extracellular-signal-regulated kinases (pERK) and c-Jun N-terminal kinase (JNK) were evaluated by western blotting; moreover the responses of pancreatic proteins to ghrelin were analyzed using the two-dimensional gel electrophoresis system. Results: The exogenous ghrelin (1.0 and 10.0 μg/kg BW) elevated the level of plasma ghrelin (p < 0.05), and suppressed the expression of pancreatic α-amylase at a dose of 10.0 μg/kg BW (p < 0.05). No difference in the level of plasma CCK was observed, even though rats were exposed to any dose of exogenous ghrelin. In addition, a combination of western blot and proteomic analysis revealed exogenous ghrelin (10.0 μg/kg BW) induced increasing the JNK and ERK expressions (p < 0.05) and four proteins such as Destrin, Anionic trypsin-1, Trypsinogen, and especially eukaryotic translation initiation factor 3 in rat pancreas. Conclusions: Taken together, exogenous ghrelin by i.p. infusion plays a role in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling pathway.

The objective of this study was to determine the effect of different stocker management programs on skeletal muscle development and growth characteristics, satellite cell (SC) activity in growing-finishing beef cattle as well as the effects of SC-conditioned media on preadipocyte gene expression and differentiation. Fall-weaned Angus steers (n = 76; 258 ± 28 kg) were randomly assigned to 1 of 4 stocker production systems: 1) grazing dormant native range (NR) supplemented with a 40% CP cottonseed meal-based supplement (1.02 kg ? steer?1 ? d?1) followed by long-season summer grazing (CON, 0.46 kg/d); 2) grazing dormant NR supplemented with a ground corn and soybean meal-based supplement fed at 1% of BW followed by short-season summer grazing (CORN, 0.61 kg/d); 3) grazing winter wheat pasture (WP) at high stocking density (3.21 steers/ha) to achieve a moderate rate of gain (LGWP, 0.83 kg/d); and 4) grazing winter WP at low stocking density (0.99 steers/ha) to achieve a high rate of gain (HGWP, 1.29 kg/d). At the end of the stocker (intermediate harvest, IH) and finishing (final harvest, FH) phases, 4 steers / treatment were harvested and longissimus muscles (LM) sampled for cryohistological immunofluorescence analysis and SC culture assays. At IH, WP steers had greater LM fiber cross-sectional area than NR steers; however, at FH, the opposite was observed (p < 0.0001). At IH, CORN steers had the lowest Myf-5+:Pax7+ SC density (p = 0.020), while LGWP steers had the most Pax7+ SC (p = 0.043). At FH, CON steers had the highest LM capillary density (p = 0.003) and their cultured SC differentiated more readily than all other treatments (p = 0.017). At FH, Pax7 mRNA was more abundant in 14 d-old SC cultures from HGWP cattle (p = 0.03). Preadipocytes exposed to culture media from proliferating SC cultures from WP cattle isolated at FH had more PPARγ (p = 0.037) and less FABP4 (p = 0.030) mRNA expression compared with NR cattle. These data suggest that different stocker management strategies can impact skeletal muscle growth, SC function, and potentially impact marbling development in growing-finishing beef cattle.

Palatal development is one of the crucial events in craniofacial morphogenesis, according to the significant signaling pathway. In the fusion of palatal shelves, EMT is a fundamental process to achieve the proper morphogenesis of palate. Mechanisms of EMT have been reported as the processes of migration, apoptosis or general EMT through the modulations through various signalling molecules. Rgs19, known as a RGS family through GTPase activity, showed the interesting epithelial expression patterns in various organogenesis including the significant expression patterns of Rgs19 in palatal development. To evaluate the precise function of Rgs19 in palatogenesis, we employed the loss of function studies using AS-ODN treatments while in vitro palate organ cultivations. Knock-down of Rgs19 using treatments of AS-ODN showed the retarded palatal fusion with the decreased patterns of apoptosis in mesial epithelium edge (MEE). In addition, alteration patterns of related genes were examined with the qRT-PCR. And EMT process was delayed in MEE throught staining of pancytokeratin, which known as epithelial cell marker. These results show that expression of Rgs19 in MEE has crucial role of EMT, also Rgs19 affects to palatal fusion by regulation of apoptosis through the signalling modulations. Palatal development is one of the crucial events in craniofacial morphogenesis, according to the significant signaling pathway. In the fusion of palatal shelves, EMT is a fundamental process to achieve the proper morphogenesis of palate. Mechanisms of EMT have been reported as the processes of migration, apoptosis or general EMT through the modulations through various signalling molecules. Rgs19, known as a RGS family through GTPase activity, showed the interesting epithelial expression patterns in various organogenesis including the significant expression patterns of Rgs19 in palatal development. To evaluate the precise function of Rgs19 in palatogenesis, we employed the loss of function studies using AS-ODN treatments while in vitro palate organ cultivations. Knock-down of Rgs19 using treatments of AS-ODN showed the retarded palatal fusion with the decreased patterns of apoptosis in mesial epithelium edge (MEE). In addition, alteration patterns of related genes were examined with the qRT-PCR. And EMT process was delayed in MEE throught staining of pancytokeratin, which known as epithelial cell marker. These results show that expression of Rgs19 in MEE has crucial role of EMT, also Rgs19 affects to palatal fusion by regulation of apoptosis through the signalling modulations.

Sharing economy platforms, represented by Uber or Airbnb have recently grown rapidly. Unlike the traditional online p2p market, providers in sharing economy platform become part of the service and have a significant impact on the overall service experience. Consequently, consumers should explore not only the product but also providers’ information before making a purchase to reduce the uncertainty of the overall quality of service. Furthermore, frequent crimes in Airbnb and Uber are increasing the importance of knowing provider information. However, the information of providers exposed on most platforms is limited to self-introduction and profile pictures. Accordingly, users should rely on this limited information to reduce service uncertainty. In this paper, we found that having a group-type host profile picture has a positive effect on the reservation rate in Airbnb. In addition, the impact of profile pictures is stronger in the cities with the high crime rate. The findings demonstrate that hosts’ group-type profile picture could serve as a signal on safety in sharing economy platforms.

A startup may have little track record and investors may not have the exact information about an entrepreneur’s true success probability. To model this, we consider a patent signaling model for startup financing where the entrepreneur signals his type by acquiring patents at his own cost and investors have coarse information about the entrepreneur’s true success probability. Rather than having the exact information about each type’s true success probability, investors only perceive the ranges of the entrepreneur’s possible success probabilities. Adopting perfect Bayesian equilibrium (PBE) as a solution concept, we consider only pure-strategy separating and pooling PBEs of the signaling game between the entrepreneur and investors. By invoking an extension of Cho and Kreps’ (1987) Intuitive Criterion adapted to our model, we obtain the unique least-cost perfect Bayesian equilibrium. In the refined equilibrium, as investors consider a higher success probability of each type, it takes more equity share. Furthermore, a high-type entrepreneur may get a smaller equity share despite of acquiring a higher level of patent than in the benchmark where investors know the exact possible success probabilites of the entrepreneur. This implies that coarse information faced by investors may lead to less effective patent-signaling than in the benchmark.

Maternal separation in the developmental stage has a negative influ-ence on brain development and causes depression. The extracellular ligand, Wnt, and its receptors play an important role in axis formation and neural development. Exercise inhibits apoptosis, increases cell proliferation, and exerts antidepressive effect. In this study, the effect of treadmill exercise on the maternal separation-induced depression was investigated in the aspect of Wnt signaling pathway. The maternal sep-aration started on the postnatal day 14. The rat pups in the exercise groups were forced to run on a treadmill for 30 min once a day from postnatal day 21 to postnatal day 34. The rat pups in the maternal sepa-ration and fluoxetine-treated group were intraperitoneally injected with 5-mg/kg fluoxetine once a day from postnatal day 21 to postnatal day 34. Forced swimming test was performed to evaluate the depression level. Western blotting was performed for the expressions of Wnt sig-naling ligands, Wnt2 and Wnt3a, and Wnt signaling inhibitors, Dkk1, and sFRP3. Maternal separation showed depressive behaviors in the forced swimming test. Treadmill exercise alleviated depressive behaviors in the maternal separation rat pups. Expressions of Wnt2 and Wnt3a were decreased by maternal separation. Treadmill exercise alleviated mater-nal separation-induced reduction of Wnt2 and Wnt3a expressions. Ex-pressions of Dkk1 and sFRP3 in the hippocampus were increased by maternal separation. Treadmill exercise alleviated maternal separa-tion-induced reduction of Dkk1 and sFRP3 expressions. Our study demonstrated that treadmill exercise activates Wnt signaling pathway, and then exerted antidepressive effect.

We consider a patent signaling model for startup financing where an entrepreneur signals his type by acquiring patents and investors have coarse information about the entrepreneur’s true success probability. By invoking an extension of Cho and Kreps’ (1987) Intuitive Criterion adapted to our model, we obtain the least-cost perfect Bayesian equilibrium, in which a high-type entrepreneur may receive a lower equity share despite acquiring a higher patent level than in the benchmark, where investors do not face coarse information. This implies that coarse information faced by investors may lead to less effective patent signaling than in the benchmark.

Notch 신호전달체계는 줄기세포의 항상성 조절뿐만 아니라 모낭을 포함한 다세포 조직의 발달 조절에도 주요한 역할을 담당한다. 다양한 연구논문을 통해 Notch 활성은 모낭 발달과정에 있어 세포의 운명을 결정하는데 매우 중대한 역할을 수행한다고 밝혀졌다. 또한, 모낭 줄기세포의 운명 조절과 모발 주기 조절 그리고 손상된 두피의 재건에도 중심적인 역할을 담당한다고 보고되고 있다. 게 다가 모구에 있어 Notch 신호전달체계는 모낭줄기세포의 분화 조절까지 그 기능이 보고되고 있다. 본 총설은 모낭의 발달 및 모낭 의 항상성 유지에 관여하는 Notch 신호전달체계 및 관련 조절 단백질들에 대한 최신 지견을 요약하고자 한다.

Notch pathway has been known as a major signal transduction route regulating stem cell homeostasis and development in multicellular organisms including hair follicles. Many studies have represented that Notch activity is critical to determine cell fate decision during hair follicle development. Also, growing results have revealed the pivotal role of Notch signaling pathway in controlling of hair follicle stem cell fates, regulation of hair cycles and resuscitation of injured hair organs. Furthermore, in hair bulb, Notch signaling pathway regulates hair follicle stem cell differentiation. The purpose of this review is to summarize considerable recent evidences in our understanding of Notch signaling and their regulating factors in hair follicle development to maintain their hair follicle homeostasis.

Notch信号通路被认为是不仅调节干细胞稳态，而且调节包括毛囊在内的多细胞组织发育的重要信号转导途径。许多研究 表明，在毛囊发育过程中，Notch活性在细胞命运决定方面起着关键作用。还有越来越多的研究结果表明，Notch信号通 路在控制毛囊干细胞命运、调控毛发周期和损伤毛发器官再生方面起着关键性的作用。此外，在毛球中，Notch信号通路 调节毛囊干细胞分化方面发挥了重要作用。本文综述了近年来参与毛囊发育和维持毛囊稳态的Notch信号通路以及相关调 控蛋白的最新研究进展。

모낭은 상피와 간엽 부분으로 구성된 작은 조직기관으로서, 모발의 발달과 성장에 매우 중요한 역할을 담당하고 있다. 배아초기단계에서 나타나는 모낭의 형성은 주로 모낭 니치(niche) 안에서의 상피-간엽 상호작용을 통해 조절되며, 이러한 상호작용은 또한 출생 이후의 모발 성장 주기와 재생에도 관여한다. 진피 모유두 세포는 모구(hair bulb)의 간엽부분에 존재하는 주요한 구성세포로, 다양한 신호물질을 발생시켜 인접한 상피세포에 전달하여 해당 세포의 행동을 조절한다. 현재까지 많은 신호전달체계들이 모낭의 발달과 성장에 관여됨이 보고되고 있으며, 가장 대표적으로 진피 모유두 세포 내 Wnt/β-catenin 기반 신호가 모낭세포와 상피세포간의 상호작용에 중요하다고 보고되고 있다. 이러한 Wnt/β-catenin 신호전달체계는 모낭 형성 및 재생에 중요하게 관여된다. 본 총설은 모낭 형성 및 주기에 있어 Wnt 신호전달체계에 대하여 현재까지 밝혀진 연구결과를 요약하고자 한다.

Hair follicle (HF) is a miniature organ composed of epithelial and mesenchymal (dermal) compartments, and has a pivotal role in hair development and growth. In embryonic, the formation of HF is mainly regulated by mesenchymal-epithelial interactions within the dermal papilla (DP) niche, and this interaction is also responsible for the postnatal hair growth cycle and regeneration. DP cells are the main components of the mesenchymal compartments in hair bulb, and have an instruction role by generating several signals to regulate the behavior of neighbor epithelial cells in hair cycle. Among the many signaling pathways implicated in HF development and growth, Wnt/β-catenin signaling in DP cells plays critical roles in the reciprocal instructive communication between DP and epithelial cells. It is clear that Wnt/β-catenin signaling pathway is important for HF morphogenesis and regeneration. The goal of this review is to summarize our current knowledge of Wnt signaling pathway in HF development and cycling.

毛囊是由上皮及真皮间充质组成的微型器官，在头发发展和生长中起关键作用。在胚胎初期，毛囊的形成主要由真皮乳 头细胞生态位内的上皮-间充质相互作用调节，并且这种相互作用也涉及生长后的毛发生长周期和再生。真皮乳头细胞是 毛球（hair bulb）内的间充质组成成分，并且通过产生多种信号来调节周围相邻的上皮细胞的行为。至今，有许多信号 通路涉及毛囊的发展和生长的报道中，真皮乳头细胞内Wnt/β-catenin信号通路对毛囊细胞和上皮细胞之间的相互作用起 关键作用。这种Wnt/β-catenin信号通路对毛囊的形成和再生是重要的。本文综述了Wnt信号通路在毛囊形成和周期中的 研究。