Narrow Results

In the presence of home firm's ability to make a cost-reducing investment before or after the government set its subsidy level, this paper analyzes the impact of timing on the optimal policy of the government. We find that under complete information assumption, the firm will overinvest and consequently, the government will over-subsidize, resulting in lower welfare levels than would arise under non-intervention. We extend the model to the case in which the home firm has private information about its own costs, which it may want to signal to the government through its investment choice. We find that under this setup, the low-cost firm overinvests even more than under full information case, making the policy of non-intervention even more attractive.

In this paper, we conduct an incentive study on the adoption of the blockchain technology in a two-period model with retailer’s use of strategic inventory. Without the adoption of the blockchain technology, the retailer has private information regarding the market size. We investigate the retailer’s voluntary signaling decisions via his pricing and strategic inventory decisions. We determine the retailer’s equilibrium price and the manufacturer’s optimal wholesale price. Both separating and pooling equilibria are discussed, and the unique lexicographically maximum sequential equilibrium is identified. With the adoption of the blockchain technology, there is no information asymmetric between the supply chain members. We find that the manufacturer has the incentive to adopt the blockchain technology when the demand uncertainty is moderate to high, and the retailer has the incentive to adopt the blockchain technology when the demand uncertainty is low or high. When the manufacturer and the retailer have a misalignment in the adoption of the technology, a central planner can help to achieve coordination.

The effects of a single oral dose of liothyronine (L-T3) on thyroid stimulating hormone (TSH) and other related thyroid system parameters are partly understood despite therapeutic use of this hormone over many decades. We characterize individualized responses of the hypothalamus-pituitary-thyroid (HPT) axis and its related temporal hormonal profile using an electrical network model. Based on thyroid hormone responses from blood samples using a single 50$\mu$g oral dose of liothyronine in healthy persons with a normal operating euthyroid feedback HPT system, we derived an equivalent electrical circuit model for the system’s responses. The mathematical model was tested with a circuit simulator and validated with individualized clinical data. This signal processing technique makes the evaluation of bioequivalence and bioavailability of various preparations of liothyronine at an individualized level a feasible endeavor for clinical application.

SINGAPORE – Human Heart Tissue Grown from Stem Cells Improves Drug Testing.

UNITED STATES – Bioengineered Human Livers Mimic Natural Development.

UNITED STATES – New Cellular Target May Put the Brakes on Cancer’s Ability to Spread.

UNITED STATES – Does Consuming Low-Fat Dairy Increase the Risk of Parkinson’s Disease?

UNITED STATES – Memory Loss and Other Cognitive Decline Linked to Blood Vessel Disease in the Brain.

AUSTRALIA – Fabricating High Performance Nanohybrid Catalysts.

TAIWAN – US FDA Approves Zhaohe Cao-based Botanical Drug as an Investigational New Drug for Cancer Therapy.

KOREA – Distinguished Professor Sang Yup Lee Elected to the NAS.

This study examines the motive for stock repurchase. We examine four hypotheses — undervaluation, signaling, free cash flow, and optimal leverage hypotheses — using both short-run and long-run market reactions. We find that the undervaluation hypothesis is most consistent with both short-run and long-run tests. Improvement in operating performance following repurchase suggests the signaling hypothesis. However, the signaling hypothesis is supported only in the long-run test, not the short-run test, suggesting that market underreaction exists to the signaling initially. Of the control variables, the target purchase ratio and ownership by the largest shareholders are found significant, suggesting that the magnitude of repurchase and the ownership increase motive by the largest shareholders are also important factors that explain the repurchase.

I argue that paying dividends before issuing new stock can increase the stock price in the case when firms announce dividend payments and new stock issuance contemporaneously. It enables issuing firms to disentangle the agency problem of paying dividends by newly-raised funds from dividend information for new stock issuances. I employ the seasoned offerings of Taiwan listed firms as the sample, because of their practice of paying dividends once a year. The conditional event study strongly supports this argument and explains why previous studies fail to detect the information conveyed by dividends for new stock issuances.

Most Initial Public Offerings (IPOs) feature share lockup agreements, which prohibit insiders and other pre-IPO shareholders from selling their shares for a specified period of time following IPO. We explore possible reasons why some IPO firms voluntarily agree to have a much longer lockup period than other firms. We find evidence that lockup agreements are used to control agency costs. Longer lockups are significantly related to inferior long-run returns and this relationship is stronger for firms that have less reputable underwriters. We find no evidence that lockup agreements are used to signal firm quality and we are unable to relate firm quality, as measured by long-run returns, to information asymmetry variables.

In a private placement, the identity of the block purchaser has attracted much attention, while the characteristics of the issuing firm are sparsely noted. We hypothesize that the market concerns about the coupling between the issuing firm and the new block investor. Our empirical findings from a sample of 213 private equity placements in Taiwan indicate that the announcement effect of good-governance firms is significantly higher than that of bad-governance firms. Moreover, the induction of outside block investor further punctuates the coupling effect: the coupling between good-governance (poor-governance) firms and outside block investors yields even higher (lower) returns. Finally, the coupling effect remains significant in explaining the long-run performance of private-equity-placement firms.

Determining the productivity of individual workers engaged in team production is difficult. Monitoring expenses may be high, or the observable output of the entire team may be some single product. One way to collect information about individual productivity is to observe how total output changes when the composition of the team changes. While some employers may explicitly shift workers from team to team for exactly this reason, the most common reasons for changes in team composition are at least partly voluntary: vacation time and sick days. In this paper, we develop a model of optimal absenteeism by employees which accounts for strategic interactions between employees. We assume the employer uses both observed changes in output and the strategies of the employees to form beliefs about a given worker's type. We argue that the model we develop is applicable to a variety of workplace situations where signaling models are not, because it allows a worker's decisions to provide information about other workers, as well as about himself.

Focusing on signaling games, I illustrate the relevance of the rationalizability approach for the analysis multistage games with incomplete information. I define a class of iterative solution procedures, featuring a notion of "forward induction": the Receiver tries to explain the Sender's message in a way which is consistent with the Sender's strategic sophistication and certain given restrictions on beliefs. The approach is applied to some numerical examples and economic models. In a standard model with verifiable messages a full disclosure result is obtained. In a model of job market signaling the best separating equilibrium emerges as the unique rationalizable outcome only when the high and low types are sufficiently different. Otherwise, rationalizability only puts bounds on the education choices of different types.

The integrin family of adhesion receptors regulates basic functions of cells, and the signals they induce are altered in tumor cells. In this review we discuss how different integrin-dependent signals are generated during cell adhesion and by physical forces acting on cells. We also describe how reactive oxygen species are integral parts of integrin signaling and highlight a few important questions in the field. Answers to those may improve our understanding of integrins and their role in the development of cancer.

This study was based on the hypothesis that spatial–temporal characterization of contaminant-affected redox gradients in a quiescent system could be measured by microbial potentiometric sensor (MPS) arrays incorporated in large, natural biofilm networks. Two experimental chambers, each containing at least 48 equidistantly located MPS electrodes, were fabricated to examine reproducibility of the patterns. The MPS electrodes were exposed to biofilm growth conditions by introducing high dissolved organic carbon (DOC) and dechlorinated tap water at the bottom of the experimental chamber; and the spatial–temporal changes in the MPS array signals were recorded, which showed that signal trends were correlated to the induced changes in DOC. The results indicated that MPS arrays measured the spatial–temporal changes in the aqueous solution caused by an influx of carbon rich water, which could not be detected by conventional oxidation-reduction potential (ORP) electrodes. Interestingly, the experiments conducted over long time periods revealed unusual behaviors like electrical signaling and possible potentiometrically driven communication within the biofilm. These observed behaviors suggest that biofilms may create a large network through which communication signals can be generated and propagated by inducing changes in electric potentials similar to a sophisticated electronic device.

In the early 2000s, many developing countries in Eastern Europe, Latin America and Asia presented substantial corporate dollar debts. This paper suggests an explanation for this worrisome phenomenon, which builds on the traditional signaling approach. The model brings into the picture specific institutional characteristics of the credit market in these countries. If lenders have no direct possibility to infer a firm's financial status, sound firms might want to borrow dollars and bear a high clearance cost -- connected to the grant procedure -- just in order to signal their type. The success of this policy depends on the behavior of bad firms. When dollar borrowing clearance costs are relatively small with respect to the clearance cost of borrowing in the local currency, the whole corporate sector would opt for liability dollarization. In this most inefficient case, the signaling effect vanishes, while all firms bear high clearance costs. We also put forward the necessary conditions for a separating equilibrium to occur.

Mesenchymal stem cells (MSCs) differentiate to cells that are part of tissues, such as bone and cartilage, both during ontogeny and for the repair/regeneration and renewal of tissues during postnatal life. Accordingly, MSCs can be a powerful tool for regenerative medicine and tissue engineering interventions in musculoskeletal deficiencies. MSCs found in the bone marrow and connective tissues are exposed to biochemical and biophysical factors that modulate their biological behavior. Given that biochemical factors have been widely studied, research on the effect of biophysical stimuli on the differentiation of MSCs is scarce. An overview of the impact of biophysical factors on MSCs osteogenic differentiation could shed light on some of the signals to consider when developing new cell therapies or tissue engineering products for the treatment of bone traumatic defects and diseases. The aim of this review is to provide an overview of the effect of biophysical stimuli on osteogenic differentiation. It focuses on reviewing what has been published on the effect of compression, tension, hydrostatic pressure, shear stress, electromagnetic fields, low-intensity ultrasound, and niche signaling – including topography and substrate stiffness, paracrine and juxtracrine regulation – on MSCs osteogenic differentiation. The knowledge gained from studying how MSCs respond to mechanical forces has the potential to drive the creation of more advanced treatments for conditions where bones are injured. These therapies could rely on either physical methods or a combination of physical and chemical approaches, offering new possibilities for improving bone health.

Cancer Stem Cells (CSCs) are a small population of cells within tumors holding stemness properties that sustain cancer progression, such as enhanced capacities for self-renewal, growing, metastasizing, homing, and reproliferating. CSCs show remarkable organizing capacities as they can educate neighboring cells to provide nutrients and collaborate in the elusion from the immune system, creating an environment favorable for tumor growth. In particular, tumor-specific microenvironments comprise stromal cells, immune cells, networks of cytokines and growth factors, hypoxic regions, and the extracellular matrix. The contribution of the microenvironment in this picture is crucial: it is now accepted that the “cancer” scenario is not simply composed of transformed cells working together in isolated and strictly autonomous machinery. Tumor microenvironment actively collaborates with neoplastic cells at different levels: promoting proliferation while evading growth suppression and immune surveillance, overcoming cell death, modulating cell metabolism, activating angiogenesis and invasion/metastasis programs. Also, the interactions between CSC and microenvironment help in their survival of common anti-cancer therapies thus being partly responsible for disease recurrence. Further studies regarding CSC/microenvironment seem to be promising for new CSC-targeting therapies, which may represent an innovative strategy for the cure of lung cancer.

The traditional equilibrium models of signaling with debt-maturity require transaction costs by firms when raising new capital. In this paper, we propose a new model that has no such requirement. We demonstrate that a separating equilibrium of debt-maturity choice exists under a much more general condition, once accounting for the interactions between borrowers and lenders. The model is able to explain the observed complex financial structure. It is found that callable debt functions much like short-term debt, and serial debt similar to long-term debt. In equilibrium, high-quality firms issue short-term debt, and low-quality firms issue long-term debt.

As control plane and signaling seems to be a critical part in next generation networks, this paper proposes an integrated control plane (ICP) for IP enabled optical networks. Signaling procedure for ensuring dynamic end-to-end lightpath setup has also been presented. Path provisioning comprises a string of operations like service and neighbor discovery, route computation, signaling requests, and path setup.

Recent results indicate that cells not directly targeted with radiation exhibit responses directly attributed to their exposure to the irradiated cells or some product of those cells. Many responses, called “bystander effects,” have been measured in unirradiated cells, ranging from transient gene expression changes to permanent, heritable changes to the genetic material. In this review, current literature regarding the transmission and nature of the molecule responsible for the bystander effect and the variables surrounding both production of and receipt of these signals is presented. Finally, consideration of the risks posed and the evolutionary implications of this phenomenon are discussed.

The following sections are included:

• Introduction
• Identification of the human repertoire of Rho GTPases
• Ontogeny and early evolution of Rho GTPases
• Diversification of the Rho family in Metazoa
• Concluding remarks
• References

In this paper, we conduct an incentive study on the adoption of the blockchain technology in a two-period model with retailer’s use of strategic inventory. Without the adoption of the blockchain technology, the retailer has private information regarding the market size. We investigate the retailer’s voluntary signaling decisions via his pricing and strategic inventory decisions. We determine the retailer’s equilibrium price and the manufacturer’s optimal wholesale price. Both separating and pooling equilibria are discussed, and the unique lexicographically maximum sequential equilibrium is identified. With the adoption of the blockchain technology, there is no information asymmetric between the supply chain members. We find that the manufacturer has the incentive to adopt the blockchain technology when the demand uncertainty is moderate to high, and the retailer has the incentive to adopt the blockchain technology when the demand uncertainty is low or high. When the manufacturer and the retailer have a misalignment in the adoption of the technology, a central planner can help to achieve coordination.