Search

Bake hardening steels have to resist strain aging to prevent the yield strength increment and stretcher strain during press process and to enhance the bake hardenability during baking process after painting. The bake hardening steels need to control the solute carbon and the solute nitrogen to improve the bake hardenability. Ti and/or Nb alloying for nitride and carbide precipitation and low carbon content below 0.003% are used to solve strain aging and formability problem for automotive materials. However, in the present study, the effect of micro-precipitation of copper sulfide on the bake hardenability and fatigue properties of extremely low carbon steel has been investigated. The bake hardenability of Cu-alloyed bake hardening (Cu-BH) steel was slightly higher (5 MPa) than that of Nb-alloyed bake hardening (Nb-BH) steel, but the fatigue limit of Cu-BH steel was far higher (45 MPa) than that of Nb-BH steel. All samples showed the ductile fracture behavior and some samples revealed distinct fatigue stages, such as crack initiation, stable crack growth and unstable crack growth. (Received July 14, 2010)

Graft versus host disease (GvHD) caused by alloreactive donor lymphocytes is a fatal complication of hematopoietic stem cell transplant (HSCT). Conditioning regimen consisting of chemotherapy and/or radiation given prior to HSCT can cause the initial tissue damage, which triggers the cross-presentation of alloantigens to the donor immune cells. Previous studies have shown that water-soluble PEGylated bilirubin nanoparticles (BRNP) selectively accumulate at the site of inflammation and prevent further tissue damage through scavenging reactive oxygen species. Therefore we, hypothesized that BRNP treatment after conditioning regimen can reduce GvHD by abating the initial tissue damage in HSCT, and investigated therapeutic efficacy of BRNP using murine GVHD model. Sublethally irradiated recipient mice (Balb/c) were infused with 4×106 bone marrow and 1×106 splenic T cells from donor mice (C57/B6) on day 1, and with or without BRNP (10mg/kg) on days 0, 2, and 4. GvHD symptoms were monitored for 60 days, and scored for changes in fur, skin, posture, activity, and weight. Untreated recipient mice (n=9) developed significantly worse GVHD (mean GVHD score=4.667) compared to BRNP treated recipient mice (n=9, mean GVHD score=1.556) (p=0.0028). This translated into the significantly better survival of BRNP treated mice with day 60 survival of 65% as compared to the untreated recipient mice with day 60 survival of 11% (p=0.03). In summary, we show that BRNP treatment can ameliorate clinical GvHD symptoms and improve survival in murine GVHD model. In the future, we plan to investigate the role of reactive oxygen species in GVHD and mechanism of action on anti-GVHD effects by BRNP.

Two different methods are used to evaluate the performance of the consumption-based asset pricing models to explain the cross-section of expected stock returns in conditional moments: one is to scale the returns, and the other is to model time-varying factor loadings, using instrument variables. Maximum correlation portfolios are constructed to directly impose restrictions on the time-series intercepts, especially in a model whose factors are not returns. The empirical results are as follow: the consumption-based models perform no better than the standard CAPM; adding the return on human capital as an additional risk factor does not help explain the cross-section; and the FamaFrench three-factor model shows the best ability to lower the pricing error.

This paper investigates the liquidity risk of U.S. mortgage-backed securities (MBS) in comparison with government and agency securities from an empirical perspective. An empirical evaluation of liquidity risk is performed by negative tails from the historical changes of daily total transactions. A set of bond market risk factors is applied to control the pure market effects on transaction changes. Once market effects are controlled, negative tails are evaluated from the underlying distributions for residual transaction changes. During the recent five years, liquidity-driven MBS transaction changes show fat tail, as well as high sample volatility. This suggests that a sudden, large drop from the normal level of transactions is more likely for MBS than for government and agency bonds, in the case that there is negative liquidity shock.

H beam welds along rolling and transverse direction were investigated with nondestructive testing, mechanical testing and microstructural analysis. Crack and fracture occurred, during guided bend testing, in the specimens welded along rolling direction between flanges of the H beams with higher S content although no defect was detected prior to the bend test. The fracture seemed to be lamellar tearing because of step-like fracture propagation and terrace and wall fracture appearance of the ruptured bend test specimen. On top of this, lamellar tear was already created in the base metal area near the HAZ before the bend test in microstructural analysis on the welds. It seems that lamellar tearing occurred in the specimens welded along rolling direction between flanges of the H beams with higher S content as cracks were formed and propagated into a ferrite phase region in α-γ band structure in combination with low ductility in transverse direction due to MnS inclusions elongated along rolling direction.

This paper introduces a direct conversion transmitter for IEEE 802.15.4 applications with a high gain up-conversion mixer. An RF DCT (Direct Conversion Transmitter) is composed of differential-ended DAC (Digital to Analog Converter), passive low pass filter, quadrature active mixer, and drive amplifier. The most important thing in designing RF direct conversion transmitter is satisfying 2.4GHz Zigbee standards with using low power and compact cell configurations. Active mixer provides enough high gain as well as sufficient ACPR (Adjacent Channel Power ratio) performance.

This paper proposes a framework for security services using Software-Defined Networking (SDN) and Interface to Network Security Functions (I2NSF). It specifies requirements for such a framework for security services based on network virtualization. It describes two representative security systems, such as (i) centralized firewall system and (ii) DDoS-attack mitigation system. For each service, this paper discusses the limitations of existing systems and presents a possible SDN-based system to protect network resources by controlling suspicious and dangerous network traffic.

Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis. Due to the increasing rates of human campylobacteriosis, C. jejuni is considered as a serious public health concern worldwide. C. jejuni is a microaerophilic, fastidious bacterium. C. jejuni must overcome a wide range of stress conditions during foodborne transmission to humans, such as food preservation and processing conditions, and even in infection of the gastrointestinal tracts of humans. Particularly, this microaerophilic foodborne pathogen must survive in the atmospheric conditions prior to the initiation of infection. C. jejuni possesses unique regulatory mechanisms for oxidative stress resistance. Lacking OxyR and SoxRS that are highly conserved in other Gram-negative foodborne pathogens, C. jejuni modulates the expression of genes involved in oxidative stress resistance mainly via the peroxide resistance regulator and Campylobacter oxidative stress regulator. Based on recent findings of ours and others, in this review, we described how C. jejuni regulates the expression of oxidative stress defense.

The focus of intelligent vehicle technology is progressing rapidly from self-control to inter-vehicle control and vehicle-infrastructure control. While international standards have been established for the evaluation of inter-vehicle control systems, few studies exist on the evaluation of control systems between vehicles and infrastructure. This study provides evaluation criteria for vehicle control systems that utilize road information; it also evaluates control performance by conducting vehicle tests in the developed evaluation scenario. The results of this study will contribute to the development of advanced evaluation methods for control systems between vehicles and infrastructure.

Heterogeneous patterns of the diversification effects are identified across the full distributions of various risk-adjusted performance measures and over time using a quantile regression of U.S. bank holding company data for the period 2000-2010. The net effect of income diversification is determined by a positive indirect effect from a diversified income structure and a negative direct effect from an increased share of non-interest income. The first main empirical finding shows a greater discount in the upper quantiles of the performance distributions. Second, the net diversification effect changes from a discount to a premium over time. These findings suggest that the diversification discount reflects a loss of comparative advantage at the early adjustment stage of income diversification. However, after the costly adjustment, the diversification benefit becomes dominant and the net effect becomes a diversification premium.

We review our current progress on semiconductor nanowires of β-Ga2O3, Si and GaN. These nanowires were grown using both vapor–solid (VS) and vapor–liquid–solid (VLS) mechanisms. Using transmission electron microscopy (TEM) we studied their morphological, compositional and structural characteristics. Here we survey the general morphologies, growth directions and a variety of defect structures found in our samples. We also outline a method to determine the nanowire growth direction using TEM, and present an overview of device fabrication and assembly methods developed using these nanowires.

It is important for an IT service company (IS company) to fully take into account the differences in customer satisfaction across different customer groups. In this article, we consider three layers of customers in the client company. There are project directors who interface with and accept the final product (i.e. IT system) from the IS company, users who actually use the IT system for their daily operations, and finally operators who do maintenance works for the IT system. We propose that each customer group (i.e. project director, user, or operator) evaluates the IT systems success with a different set of criteria. Transaction relationship and partnership turn out to be important determinants for the project directors: task‐related and IS‐related output performances seem to be less influential. The reverse conclusion can be made for users and operators. One additional insight is that IS company’s efforts to understand its customer’s tasks and share risks with the customer company might have unexpected effects. Although the project directors seem to like such close involvement, it can be detrimental to the users’ satisfaction with the IS outsourcing projects.

In recent years, improving fuel economy for greenhouse gas (GHG) reduction has emerged as an important issue in the automotive industry. Consequently, the complex forming method for weight reduction has been applied to front axle beams for medium-duty commercial vehicles. For the strength analysis of lightweight front axle beams, the present study developed, tested, and verified a precise strength analysis model to which the dynamic technique had been applied. It will be possible to utilize these results usefully for strength analysis of lightweight front axle beams.

This study describes a technique to quantify muscle fascicle directions in the levator ani (LA) and tests the null hypothesis that the in vivo fascicle directions for each LA subdivision subtend the same parasagittal angle relative to a horizontal reference axis. Visible muscle fascicle direction in the each of the three LA muscle subdivisions, the pubovisceral (PVM; synonymous with pubococcygeal), puborectal (PRM), and iliococcygeal (ICM) muscles, as well as the external anal sphincter (EAS), were measured on 3-T sagittal MRI images in a convenience sample of 14 healthy women in whom muscle fascicles were visible. Mean ± standard deviation (SD) angle values relative to the horizontal were calculated for each muscle subdivision. Repeated measures ANOVA and post-hoc paired t tests were used to compare muscle groups. Pubovisceral muscle fiber inclination was 41 ± 8.0°, PRM was −19 ± 10.1°, ICM was 33 ± 8.8°, and EAS was −43 ± 6.4°. These fascicle directions were statistically different (p

The usual cross-sectional tests of asset pricing models suffer from lack of power because they do not impose the null hypothesis of zero pricing errors on a full set of test assets. This paper proposes a simple remedy using full-rank maximum correlation portfolios obtained by adding extra return bases to test assets, allowing the cross-sectional tests to be performed with full degrees of freedom. I show that the resulting test statistic is equivalent to the Hansen-Jagannathan distance with an expanded set of returns. The statistical test has more power and rejects most of the recent asset pricing models in the literature.

For the physical objectives of the KSTAR tokamak, a predictive transport/heating/current drive simulation package has been developed and named ASTRA/LSC/TORIC. A new simulation package consists of the ray tracing lower hybrid wave code LSC, a neutral beam Fokker-Planck solver and the ICRF full wave code TORIC together with the transport code ASTRA. The new simulation package ASTRA/LSC/TORIC can be applied to many interesting research areas such as heating and non-inductive current drive physics for a steady state plasma, predictive study of advanced tokamak modes with a, for example, high beta, high H factor and high bootstrap current. Studies into two kinds of question are made: (a) Can the total required plasma current Ip (a baseline heating mode with 1.5 MA and an upgrade heating mode with 2.0 MA) be driven fully non-inductively and be sustained during a flat-top phase of reasonable KSTAR reference plasma parameter ranges with the help of auxiliary KSTAR heating (H) and current drive (CD) systems (NBH/CD, LHH/CD and ICRH/CD)? (b) Can a reversed shear mode be developed in an early ramp-up phase and be sustained during a flat-top phase? These predictive simulation results using a newly developed simulation package are presented.

U.S. bank holding companies (BHCs) have experienced dynamic changes over a period of 2000–2010. We find that the size distribution of sample banks becomes highly positively skewed with a small number of big banks becoming super-sized, and these big banks tend to take extra risk by holding derivative positions for trading purposes. The ten largest risk-taking banks hold about 70% of total assets of all the sample banks in 2010. We investigate whether the risk-taking activities of the BHCs translate into higher risk-adjusted return performance. In extensive panel regression analyses, we find that the risk-taking strategies of large banks by holding derivative positions for trading purpose do not show the clear evidence of enhancing risk-adjusted performance. We find that negative impacts of extra risk-taking on the risk-adjusted performance become bigger with the size of banks.

Since the adoption of Bali Roadmap in 2007, the efforts to reduce Green House Gases (GHGs) Emissions are growing with concern of new agreement against climate change. Under Kyoto Protocol, Annex I parties which have received mandatory target of GHG emissions implement lots of policies for reducing GHG emissions. Beside Annex I parties, many countries set their own GHG emissions target and make efforts to achieve the target in many ways. Each country introduces voluntary agreements and negotiated agreements to reduce GHG emissions in industrial sector that occupies a large part of national GHG emissions. As the demand on reduction of GHG emission is strengthening, climate change policies come up in form of negotiated agreements. The existence of the obligation affects countries’ GHG reduction policies’ intensity. According to recent discussion about post-Kyoto protocol, it is expected that some countries as China, South Korea, and India would receive the mandatory target of GHG emission.

This paper explores a transmission mechanism of an exogenous shock to domestic financial markets by investigating the potential signaling role of the Monetary Stabilization Bond (MSB) spread together with several financial variables in Korea. The MSB spread widened and became more volatile during the crisis period after the variance change point at the end of 2007, when the causality relationships between the key variables became apparent. The empirical results illustrate that a foreign shock, which directly leads to rapid short-term capital flow and foreign exchange rate fluctuation, is likely to have a significant contagion effect on domestic financial markets in the case where it has a sizable negative impact on national foreign reserve holdings. The MSB is a monetary policy instrument for foreign exchange reserve management, and the daily observable MSB spread is a timelier signal in this transmission channel.

Specific information about how telomerase acts in vivo is necessary for understanding telomere dynamics in human tumor cells. Our results imply that, under homeostatic telomere length-maintenance conditions, only one molecule of telomerase acts at each telomere during every cell division and processively adds ∼60 nt to each end. In contrast, multiple molecules of telomerase act at each telomere when telomeres are elongating (nonequilibrium conditions). Telomerase extension is less processive during the first few weeks following the reversal of long-term treatment with the telomerase inhibitor Imetelstat (GRN163L), a time when Cajal bodies fail to deliver telomerase RNA to telomeres. This result implies that processing of telomerase by Cajal bodies may affect its processivity. Overexpressed telomerase is also less processive than the endogenously expressed telomerase. These findings reveal two major distinct extension modes adopted by telomerase in vivo.

The origin of the pubovisceral muscle (PVM) from the pubic bone is known to be at elevated risk for injury during difficult vaginal births. We examined the anatomy and histology of its enthesial origin to classify its type and see if it differs from appendicular entheses.Parasagittal sections of the pubic bone, PVM enthesis, myotendinous junction, and muscle proper were harvested from five female cadavers (51-98 years). Histological sections were prepared with hematoxylin and eosin, Masson's trichrome, and Verhoeff-Van Gieson stains. The type of enthesis was identified according to a published enthesial classification scheme. Quantitative imaging analysis was performed in sampling bands 2 mm apart along the enthesis to determine its cross-sectional area and composition.The PVM enthesis can be classified as a fibrous enthesis. The PVM muscle fibers terminated in collagenous fibers that insert tangentially onto the periosteum of the pubic bone for the most part. Sharpey's fibers were not observed. In a longitudinal cross-section, the area of the connective tissue and muscle becomes equal approximately 8 mm from the pubic bone.The PVM originates bilaterally from the pubic bone via fibrous entheses whose collagen fibers arise tangentially from the periosteum of the pubic bone.

A number of recent papers have developed multifactor extensions of the classic consumption capital asset pricing model (CCAPM) and generally concluded that conditioning information improves the empirical performance. However, the empirical work to date has primarily employed cross-sectional regressions that ignore theoretical restrictions on the time-series intercepts in regressions of stock returns on model’s factors. This paper asks whether the superior empirical performance of the multifactor CCAPMs is maintained once the time-series intercept restrictions have been explicitly tested. The empirical findings support the conclusion that multifactor CCAPMs can explain the cross-section of expected stock returns better than classic unconditional models. Moreover, several of the multifactor CCAPMs are shown to perform as well as or better than the Fama and French (1993) three-factor model.

Background: Stress Granules (SG) are sites of accumulation of stalled initiation complexes that are induced following a variety of cellular insults. In a genetic screen for factors involved in protecting human myoblasts from acute oxidative stress, we identified a gene encoding a protein we designate SGNP (Stress Granule and Nucleolar Protein). Methodology/Principal Findings: A gene-trap insertional mutagenesis screen produced one insertion that conferred resistance to sodium arsenite. RT-PCR/39 RACE was used to identify the endogenous gene expressed as a GFP-fusion transcript. SGNP is localized in both the cytoplasm and nucleolus and defines a non-nucleolar compartment containing 5.8S rRNA, a component of the 60S ribosomal subunit. Under oxidative stress, SGNP nucleolar localization decreases and it rapidly co-localizes with stress granules. The decrease in nucleolar SGNP following oxidative stress was accompanied by a large increase in nucleolar 5.8S rRNA. Knockdown of SGNP with shRNA increased global mRNA translation but induced growth arrest and cell death. Conclusions: These results suggest that SGNP is an essential gene that may be involved in ribosomal biogenesis and translational control in response to oxidative stress.

Gallium nitride (GaN) nanowires (NW) and various nanostructures were grown by thermal reaction of gallium oxide and ammonia. The interplay between Ga/N reactant ratio and characteristic lengths of polar surfaces explained morphology variation. Field effect transistors were patterned on 40~185 nm diameter NWs by Ga + focused ion beam (FIB) direct Pt deposition. The devices exhibited no gate responses with liner I-V for "small" diameter NWs. Linear I-V was unexpected since Pt forms Schottky barriers on n-GaN. I-V-T characteristics of the FIB-Pt contacts evolved from ohmic to rectifying with increasing NW diameter with strongly nonmetallic T-dependence. For small diameters, two-dimensional variable range hopping explained the contact conduction, the disorder being associated with ion-beam-induced sputtering and amorphization in the GaN under the FIB-Pt, as corroborated by transmission electron microscopy (TEM). For large diameters, back-to-back Schottky barriers explained the nonlinear I-V. High carrier concentration was confirmed explaining the absence of gate responses. Finally, Young's modulus E and quality factor Q of GaN NW were measured using in-situ TEM electromechanical resonance analysis. For large diameters, E was ~300 GPa but decreased for smaller diameters. Q was greater than was obtained from micromachined Si resonators with comparable surface-to-volume ratio, implying significant advantages of GaN NW for nanoelectromechanical applications.

CCAAT/enhancer-binding protein epsilon (C/EBPepsilon) is a neutrophil-specific transcription factor whose activity is controlled by juxtaposed activating and regulatory domains. We previously determined that the function of the major regulatory domain (RD1) in C/EBPepsilon was dependent on the integrity of a five-amino acid motif that was identical to the recognition site for members of the small ubiquitin-like modifier (SUMO) family of ubiquitin-related proteins. We show here that the SUMO attachment site (the regulatory domain motif) is necessary and sufficient both for the intrinsic inhibitory function of RD1 and for coactivation by PIASxalpha and PIASxbeta, two members of the protein inhibitor of activated STAT (PIAS) family of SUMO E3 ligases. PIASxbeta was a more potent coactivator than PIASxalpha of both full-length C/EBPepsilon and fusion proteins containing the N-terminal portion of C/EBPepsilon, whereas PIASxalpha was more active on fusion proteins containing a heterologous activation domain. Two modes of coactivation were observed, one that was dependent on the integrity of the RING finger (RF) domain and was shared by both PIASxalpha and PIASxbeta and a second mode that was independent of the RF and was only observed with PIASxbeta. Sumoylation of C/EBPepsilon was enhanced by coexpression of PIASxalpha, suggesting that this modification is associated with the enhanced activity of the target protein. These results suggest that a complex interplay of accessory factors, including SUMO and PIAS proteins, modulates the activity of C/EBPepsilon.

CCAAT/enhancer-binding proteins (C/EBPs) are basic region/leucine zipper transcription factors that function as regulators of cell growth and differentiation in numerous cell types. We previously localized transcriptional activation and inhibitory regions in one family member, C/EBP epsilon. Here we describe the further characterization of a C/EBP epsilon inhibitory domain termed regulatory domain I. We show that functionally related domains are present in C/EBP alpha, C/EBP beta, and C/EBP delta. These domains contain an evolutionarily conserved five-amino acid motif (the regulatory domain motif (RDM)) that conforms to the consensus sequence (I/V/L)KXEP. Mutagenesis studies revealed that the residues at positions 1, 2, and 4 of the RDM are critical for inhibitory domain function. Data base searches identified RDM-like sequences in a number of nuclear proteins. We found that small regions from c-Jun, JunB, and JunD containing this sequence also function as transcriptional inhibitory domains. Importantly, the RDM is similar to the recognition sequence for attachment of the ubiquitin-like protein, small ubiquitin-like modifier-1 (SUMO-1), and the conserved lysine residue of each C/EBP RDM served as an attachment site for SUMO-1. SUMO-1 attachment decreased the inhibitory effect of the C/EBP epsilon regulatory domain, suggesting that sumoylation may play an important role in modulating C/EBP epsilon activity as well as that of the other C/EBP family members.

The aqueous chemical coating route is highly effective in preparing BaTiO3 nanoparticles uniformly coated with additives. Such nanoparticles can be used to produce nano-grained temperature stable BaTiO3 ceramics with core–shell structure, fulfilling the need of next-generation ultrathin layer base metal electrode (BME) multilayer ceramic capacitors (MLCCs). Rare earth oxides are an important class of additives owing to their ability to fulfill both donor and acceptor roles. In this paper, the effects of Y2O3 and Ho2O3 co-dopant content on dielectric and microstructural properties were investigated. By applying chemical coating, BaTiO3-based high performance temperature stabilized ceramics with the average grain size of about 130 nm, which met the requirement of next generation BME MLCCs, were obtained.

Nanopatterned Pt by Ga+ focused ion beam (FIB) decomposition of an organometallic precursor forms low resistance ohmic contacts on 40–70nm diameter GaN nanowires (NWs) grown by thermal reaction of Ga2O3 and NH3. With no intentional doping, the wires are presumed to be n type. Thus, the linear I‐V behavior is surprising since evaporated Pt usually forms Schottky barriers on n GaN. Ohmic behavior was not obtained for 130–140 diameter wires, even with thicker Pt contacts. A second application of FIB Pt nanopatterning was demonstrated by position-selective growth of GaN NWs on Pt catalyst dots. NW locations and density are defined by the position, size, and thickness of the Pt deposit. Combining these techniques provides a versatile platform for nanostructure research and development.