Real Options: Strategic Technology Migration Options in Wireless Industry

The major US wireless operators already have announced their plans for evolution of their networks, but some uncertainties remain, such as emergence of new technologies (WiMAX and WLAN) and consolidation among operators (AT&T Mobile and Sprint Nextel). The paper proposes a real option based model for technology decisions and applies it to the US wireless industry as a case study. We also discuss what decisions are made, what the outcomes are, and how the options model is validated. The preliminary results show that the evolution of wireless network technologies between generations (intergenerations migration scenario) is desirable (a positive net option value), but not desirable (a negative net option value) within generations (intra-generation migration scenario)

Analyzing User Behavior Against Phishing Emails

One of the most common cyberattacks is phishing, which preys on unsuspecting users to click hyperlinks to activate malicious software (called ‘malware’). A phishing attack is designed for the purpose of either damaging the victim’s computer or more commonly, hijacking that person’s computer to steadily relay personal information to a host. However, it is less understood what the various attributes and characteristics of a specific phishing attack are leading to successful execution of a malware attack. Rather, it is even less understood what types of human behaviors are leading to the initial allowance of this attack. The objectives of this study are to observe and identify the behavior of a participant (victim) during and after a phishing attack, and to understand the various behavioral characteristics of a phishing attack’s victim. This study conducted an experiment to identify the various behavioral characteristics of a phishing attack’s victim both during and after a successful phishing attack has been executed

The Real Options to Technology Management: Strategic Options for 3G Wireless Network Architecture and Technologies

The increasing demands for high-quality multimedia services have challenged the wireless industry to rapidly develop wireless network architecture and technologies. These demands have led wireless service providers to struggle with the current network migration dilemma of how to best deliver high-quality multimedia services. Currently, there are many alternative wireless network technologies, such as TDMA, GSM, GPRS, EDGE, WCDMA, cdma2000, etc. These wireless technology choices require close examination when making strategic decisions involving network evolution.This study assesses the technology options for wireless networks to establish next generation networks (i.e., 3G), based on the real options approach (ROA), and discusses wireless network operators¡¯ technology migration strategies. The goal of this study is to develop a theoretical framework for wireless network operators to support their strategic decision-making process when considering technology choices. The study begins by tracing the evolution of technologies in wireless networks to place them in the proper context, and continues by developing the strategic technology option model (STOM) using ROA as an assessment tool. Finally, STOM is applied to the world and US wireless industries for the formulation of technology migration strategies. Consequently, this study will help wireless network service providers make strategic decisions when upgrading or migrating towards the next generation network architecture by showing the possible network migration paths and their relative value. Through this study, network operators can begin to think in terms of the available network options and to maximize overall gain in networks. Since the migration issues concerning the next generation wireless network architecture and technologies remain the subject of debate, with no substantial implementation in progress now, this study will help the industry to decide where best to focus its efforts and can be expanded for further research

ねじれ積多様体上の共調和変換

We study the twisted product manifold with vanishing conharmonic curvature tensor which is invariant under the conharmonic transformation, and characterize the total space, base space and each fibre

Solution-processed germanium nanowire-positioned Schottky solar cells

Germanium nanowire (GeNW)-positioned Schottky solar cell was fabricated by a solution process. A GeNW-containing solution was spread out onto asymmetric metal electrodes to produce a rectifying current flow. Under one-sun illumination, the GeNW-positioned Schottky solar cell yields an open-circuit voltage of 177 mV and a short-circuit current of 19.2 nA. Schottky and ohmic contacts between a single GeNW and different metal electrodes were systematically investigated. This solution process may provide a route to the cost-effective nanostructure solar architecture

TRAIL sensitize MDR cells to MDR-related drugs by down-regulation of P-glycoprotein through inhibition of DNA-PKcs/Akt/GSK-3β pathway and activation of caspases

<p>Abstract</p> <p>Background</p> <p>The development of new modulator possessing high efficacy, low toxicity and high selectivity is a pivotal approach to overcome P-glycoprotein (P-gp) mediated multidrug resistance (MDR) in cancer treatment. In this study, we suggest a new molecular mechanism that TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) down-regulates P-glycoprotein (P-gp) through inhibition of DNA-PKcs/Akt/GSK-3β pathway and activation of caspases and thereby sensitize MDR cells to MDR-related drugs.</p> <p>Results</p> <p>MDR variants, CEM/VLB_10-2, CEM/VLB_55-8and CEM/VLB₁₀₀cells, with gradually increased levels of P-gp derived from human lymphoblastic leukemia CEM cells, were gradually more susceptible to TRAIL-induced apoptosis and cytotoxicity than parental CEM cells. The P-gp level of MDR variants was positively correlated with the levels of DNA-PKcs, pAkt, pGSK-3β and c-Myc as well as DR5 and negatively correlated with the level of c-FLIPs. Hypersensitivity of CEM/VLB₁₀₀cells to TRAIL was accompanied by the activation of mitochondrial apoptotic pathway as well as the activation of initiator caspases. In addition, TRAIL-induced down-regulation of DNA-PKcs/Akt/GSK-3β pathway and c-FLIP and up-regulation of cell surface expression of death receptors were associated with the increased susceptibility to TRAIL of MDR cells. Moreover, TRAIL inhibited P-gp efflux function via caspase-3-dependent degradation of P-gp as well as DNA-PKcs and subsequently sensitized MDR cells to MDR-related drugs such as vinblastine and doxorubicin. We also found that suppression of DNA-PKcs by siRNA enhanced the susceptibility of MDR cells to vincristine as well as TRAIL via down-regulation of c-FLIP and P-gp expression and up-regulation of DR5.</p> <p>Conclusion</p> <p>This study showed for the first time that the MDR variant of CEM cells was hypersensitive to TRAIL due to up-regulation of DR5 and concomitant down-regulation of c-FLIP, and degradation of P-gp and DNA-PKcs by activation of caspase-3 might be important determinants of TRAIL-induced sensitization of MDR cells to MDR-related drugs. Therefore, combination of TRAIL and chemotherapeutic drugs may be a good strategy for treatment of cancer with multidrug resistance.</p

Clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease according to their epitopes

BackgroundThe detection of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Ab) is essential for the diagnosis of MOG-Ab-associated disease (MOGAD). The clinical implications of different epitopes recognized by MOG-Ab are largely unknown. In this study, we established an in-house cell-based immunoassay for detecting MOG-Ab epitopes and examined the clinical characteristics of patients with MOG-Ab according to their epitopes.MethodsWe conducted a retrospective review of patients with MOG-Ab-associated disease (MOGAD) in our single center registry, and collected serum samples from enrolled patients. Human MOG variants were generated to detect epitopes recognized by MOG-Ab. The differences in clinical characteristics according to the presence of reactivity to MOG Proline42 (P42) were evaluated.ResultsFifty five patients with MOGAD were enrolled. Optic neuritis was the most common presenting syndrome. The P42 position of MOG was a major epitope of MOG-Ab. The patients with a monophasic clinical course and childhood-onset patients were only observed in the group that showed reactivity to the P42 epitope.ConclusionWe developed an in-house cell-based immunoassay to analyze the epitopes of MOG-Ab. The P42 position of MOG is the primary target of MOG-Ab in Korean patients with MOGAD. Further studies are needed to determine the predictive value of MOG-Ab and its epitopes

Effect of rapid influenza diagnostic tests on patient management in an emergency department

Objective We evaluated the effect of rapid influenza diagnostic tests (RIDTs) on patient management in an emergency department for 3 years after 2009, and also identified factors associated with the choice of treatment for patients with influenza-like illnesses. Methods The study period consisted of three influenza epidemic seasons. Patients older than 15 years who underwent RIDTs in the emergency department and were then discharged without admission were included. Results A total of 453 patients were enrolled, 114 of whom had positive RIDT results and 339 had negative results. Antiviral medication was prescribed to 103 patients (90.4%) who had positive RIDT results, while 1 patient (0.3%) who tested negative was treated with antivirals (P<0.001). Conservative care was administered to 11 RIDT-positive patients (9.6%) and 244 RIDT-negative patients (72.0%) (P<0.001). Symptom onset in less than 48 hours, being older than 65 years, and the presence of comorbidities were not associated with the administration of antiviral therapy. Conclusion RIDT results had a critical effect on physician decision-making regarding antiviral treatment for patients with influenza-like illnesses in the emergency department. However, symptom onset in less than 48 hours, old age, and comorbidities, which are all indications for antiviral therapy, were not found to influence the administration of antiviral treatment