Sequence- and site-specific photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue

Oh, Joo Yeon,Moon, Jeong Hee,Kim, Myung Soo John Wiley Sons, Ltd. 2004 Rapid communications in mass spectrometry Vol.18 No.22

<P>Photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue was investigated using a homebuilt tandem time-of-flight mass spectrometer equipped with a matrix-assisted laser desorption/ionization source. Efficient photodissociation of the protonated peptides was demonstrated. Most of the intense peaks in the laser-induced tandem mass spectra were sequence ions. Furthermore, sequence ions due to cleavages at all the peptide bonds were observed; this is a feature of the technique that is particularly useful for peptide sequencing. Fragmentations at both ends of the tryptophanyl residue were especially prevalent, which can be useful for location of the tryptophanyl chromophore in a peptide. Copyright © 2004 John Wiley & Sons, Ltd.</P>

Client ahead-of-time compiler for embedded Java platforms

Hong, Sunghyun,Kim, Jin-Chul,Moon, Soo-Mook,Shin, Jin Woo,Lee, Jaemok,Oh, Hyeong-Seok,Choi, Hyung-Kyu John Wiley Sons, Ltd. 2009 SOFTWARE-PRACTICE & EXPERIENCE Vol.39 No.3

<P>Many embedded Java platforms execute two types of Java classes: those installed statically on the client device and those downloaded dynamically from service providers at run time. For achieving higher performance, the static Java classes can be compiled into machine code by ahead-of-time compiler (AOTC) in the server, and the translated machine code can be installed on the client device. Unfortunately, AOTC cannot be applicable to the dynamically downloaded classes. This paper proposes client-AOTC (c-AOTC), which performs AOTC on the client device using the just-in-time compiler (JITC) module installed on the device, obviating the JITC overhead and complementing the server-AOTC. The machine code of a method translated by JITC is cached on a persistent memory of the device, and when the method is invoked again in a later run of the program, the machine code is loaded and executed directly without any translation overhead. A major issue in c-AOTC is relocation because some of the address constants embedded in the cached machine code are not correct when the machine code is loaded and used in a different run; those addresses should be corrected before they are used. Constant pool resolution and inlining complicate the relocation problem, and we propose our solutions. The persistent memory overhead for saving the relocation information is also an issue, and we propose a technique to encode the relocation information and compress the machine code efficiently. We developed a c-AOTC on Sun's CDC VM reference implementation, and our evaluation results indicate that c-AOTC can improve the performance significantly, as much as an average of 12% for EEMBC and 4% for SpecJVM98, with a persistent memory overhead of 1% on average. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Performance analysis of APSK modulation for DVB-S2 transmission over nonlinear channels

Sung, Wonjin,Kang, Seokheon,Kim, Pansoo,Chang, Dae-Ig,Shin, Dong-Joon John Wiley Sons, Ltd. 2009 International journal of satellite communications Vol.27 No.6

<P>For increased bandwidth efficiency and receiver performance, standards for satellite broadcasting systems are evolving by utilizing efficient transmission techniques. The second-generation digital video broadcasting for satellites (DVB-S2) adopts the amplitude phase shift keying (APSK) modulation for enhanced performance over nonlinear channels. In this paper, we derive error rate bounds for APSK modulated symbols and generalize the bounds to the case of distorted constellation, which occurs when the maximum transmission amplitude is saturated by the soft-limiter type channel. The derived bound is shown to significantly improve the previously known result, to accurately predict both the symbol error rate and bit error rate in the entire signal-to-noise ratio (SNR) region of interest. Using the derived formula, the optimal input power level for the soft-limiter channel is determined, and the corresponding minimal error rates for 16- and 32-APSK are quantified. The result is also interpreted in terms of optimal input back-off (IBO) for nonlinear power amplifiers by evaluating the performance degradation as a function of IBO. Copyright © 2009 John Wiley & Sons, Ltd.</P>

Kinetics and mechanism of the aminolysis of dimethyl and methyl phenyl phosphinic chlorides with anilines

Dey, Nilay Kumar,Hoque, Md. Ehtesham Ul,Kim, Chan Kyung,Lee, Bon-Su,Lee, Hai Whang John Wiley Sons, Ltd. 2009 Journal of physical organic chemistry Vol.22 No.5

<P>The reactions of dimethyl phosphinic chloride (1) and methyl phenyl phosphinic chloride (2) with X-anilines have been studied kinetically in acetonitrile at 15.0 and 55.0 °C, respectively. The deuterium kinetic isotope effects (KIEs) involving deuterated aniline nucleophiles (XC<SUB>6</SUB>H<SUB>4</SUB>ND<SUB>2</SUB>) are also reported for the same reactions. The obtained KIEs for 1 are secondary inverse (k<SUB>H</SUB>/k<SUB>D</SUB> = 0.703–0.899 < 1), while those for 2 are primary normal (k<SUB>H</SUB>/k<SUB>D</SUB> = 1.62–2.10 > 1). A concerted mechanism involving predominantly backside nucleophilic attack is proposed for the anilinolysis of 1. A concerted mechanism involving predominantly frontside attack via a hydrogen-bonded four-center-type transition state is proposed for the anilinolysis of 2. The degree of steric hindrance is the major factor that determines both the reactivity of the phosphinates and the direction of the nucleophilic attack on the phosphinates. Copyright © 2008 John Wiley & Sons, Ltd.</P> <B>Graphic Abstract</B> <P>Phosphoryl transfer reactions are known to proceed via two main types of mechanisms: a stepwise mechanism involving a trigonal bipyramidal pentacoordinate (TBP-5C) intermediate and a concerted mechanism via a single TBP-5C transition state (TS). When the nucleophile attacks the reaction center from the side opposite the leaving group (backside attack), the configuration is inversed. However, when the nucleophile attacks from the leaving group side (frontside attack), the configuration is retained. <img src='wiley_img/08943230-2009-22-5-POC1478-gra001.gif' alt='wiley_img/08943230-2009-22-5-POC1478-gra001'> </P>

Composite beam composed of steel and pre-cast concrete. (Modularized Hybrid System, MHS) Part II: analytical investigation

Hong, Won-Kee,Kim, Jin-Min,Park, Seon-Chee,Kim, Seung-Il,Lee, Seung-Geun,Lee, Ho-Chan,Yoon, Ki-Joon John Wiley Sons, Ltd. 2009 The structural design of tall and special building Vol.18 No.8

<P>This paper introduces the concept of a wide flange steel beam with the bottom flange encased in pre-cast concrete. These composite beams utilize the merits of both steel and concrete materials. The effective interaction between the two materials can reduce the size of the steel beams. The reinforcement and the concrete are pre-integrated with the bottom flange of the steel beam at a manufacturing plant. In this paper, the analytical investigation of the flexural moment strength of the composite beams at both the yield limit state and the maximum load limit state is performed and compared with the experimental results. The depth of the equivalent rectangular stress block of the beams is obtained using an equilibrium equation when both the compression steel reinforcements are present. The post-yield behaviour of the composite beams is also investigated based on the normalized effective stiffness <TEX> <img src='wiley_img/15417794-2009-18-8-TAL484-ueq001.gif' alt='wiley_img/15417794-2009-18-8-TAL484-ueq001'> </TEX> versus the normalized drift ratio <TEX> <img src='wiley_img/15417794-2009-18-8-TAL484-ueq002.gif' alt='wiley_img/15417794-2009-18-8-TAL484-ueq002'> </TEX>. The stiffness of the composite beams degrades gradually with sufficient ductility and dissipating energy capability. A six-step procedure provides a fast, effective and accurate way of investigating the post-yield behaviour of the composite beams. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Qualitative and quantitative comparison of N-glycans between pig endothelial and islet cells by high-performance liquid chromatography and mass spectrometry-based strategy

Kim, Yun-Gon,Gil, Geun-Cheol,Jang, Kyung-Soon,Lee, Sukmook,Kim, Hyoung-Il,Kim, Jung-Sik,Chung, Junho,Park, Chung-Gyu,Harvey, David J.,Kim, Byung-Gee John Wiley Sons, Ltd. 2009 Journal of mass spectrometry Vol.44 No.7

<P>N-glycan structures released from miniature pig endothelial and islet cells were determined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), negative ion electrospray ionization (ESI) MS/MS and normal-phase high performance liquid chromatography (NP-HPLC) combined with exoglycosidase digestion. Totally, the identified structures were 181 N-glycans including 129 sialylated and 18 α-galactosylated glycans from pig endothelial cells and 80 N-glycans including 41 sialylated and one α-galactosylated glycans from pig islet cells. The quantity of the α-galactosylated glycans from pig islet cells was certainly neglectable compared to pig endothelial cells. A number of NeuGc-terminated N-glycans (80 from pig endothelial cells and 13 from pig islet cells) are newly detected by our mass spectrometric strategies. The detailed structural information will be a matter of great interest in organ or cell xenotransplantation using α 1,3-galactosyltransferase gene-knockout (GalT-KO) pig. Copyright © 2009 John Wiley & Sons, Ltd.</P>

Performance test of a tuned liquid mass damper for reducing bidirectional responses of building structures

Heo, Jae-Sung,Lee, Sung-Kyung,Park, Eunchurn,Lee, Sang-Hyun,Min, Kyung-Won,Kim, Hongjin,Jo, Jiseong,Cho, Bong-Ho John Wiley Sons, Ltd. 2009 The structural design of tall and special building Vol.18 No.7

<P>In this study, a tuned liquid mass damper (TLMD) was proposed to reduce bidirectional responses of building structures, and its control performance was experimentally evaluated. The proposed TLMD with only one device body reduces bidirectional responses of building structures by behaving as a TMD and a TLCD in the weak and strong axial directions of a building floor plan, respectively. First, the control performance of a TLMD mounted on a scale-downed single-degree-of-freedom building model was experimentally evaluated by exciting this system with an actuator. Then, the real-time hybrid shaking table testing method (RTHSTTM) was performed to assess the control efficiency of the total system by adopting the TLCD and the building model as the experimental and numerical parts, respectively. It was confirmed by comparing uncontrolled and controlled testing results that the proposed TLMD can be applied to reduce the responses in both the weak and strong directions of building structures. Also, the results from RTHSTTM showed that the performance of TLMD-controlled building structure can be accurately evaluated by this method only using a TLMD as the experimental part. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Predicting mating flights through meteorological cues using multi-scale logistic regression

Kim, MyungSuk,Lim, Johan,Wang, Suojin John Wiley Sons, Ltd. 2009 Environmetrics Vol.20 No.3

<P>The red imported fire ant is one of the most destructive animals in the US. Its prolific ability through mating flights has aggravated the situation. Understanding the environmental cues triggering mating flights would be important for a comprehensive control solution. Fire ant colony activities related to mating flights were daily monitored from April 2001 to March 2002, and the associated weather data were documented. The method of logistic regression is used to identify environmental factors associated with mating flight where multi-scale decomposition of the meteorological variables is considered to identify the within and the between cues for mating flights. Our empirical results indicate that ambient temperature, relative humidity, wind speed, barometric pressure, and recent rain are significant factors that trigger or influence fire ant mating flights. Among those factors, the ambient temperature, the change in barometric pressure, relative humidity, wind speed, and recent rain are found to be the macro-scale cues, whereas the ambient temperature is also found to be the micro-scale cues. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Oxidative stress resistance through blocking Hsp60 translocation followed by SAPK/JNK inhibition in aged human diploid fibroblasts

Lee, Young-Hee,Govinda, Bhattarai,Kim, Jae-Cheol,Kim, Tae-Il,Lee, Nan-Hee,Lee, Jung-Chang,Yi, Ho-Keun,Jhee, Eun-Chung John Wiley Sons, Ltd. 2009 CELL BIOCHEMISTRY AND FUNCTION Vol.27 No.1

<P>The stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) pathway is a well-known senescence-related stress activated protein kinase. Multiple environmental stresses induce programmed cell death, such as apoptosis. Normal human diploid fibroblast (HDF) cells have a limited life span in vitro, halting proliferation after a fixed number of cell divisions. Aged passage HDF showed resistance to oxidative stress involving heat shock proteins (Hsp60) through a mechanism involving the translocation of Hsp60 from the mitochondria to the cytosol. The present study showed that the translocation of Hsp60 from the mitochondria to the cytosol followed by high levels of p-SAPK/JNK activation as a result of oxidative stress was observed in the young cells only. The inhibition of SAPK/JNK activation by SP600125 under oxidative stress almost completely blocked the translocation of Hsp60 in both young and aged cells. This suggests that aged HDF cells are resistant to oxidative stress by blocking the translocation of Hsp60 from the mitochondria to the cytosol followed by SAPK/JNK inhibition. Overall, the mechanism of resistance by oxidative stress in aged cells is induced by blocked of the translocation of Hsp60 followed by SAPK/JNK inactivation. Copyright © 2008 John Wiley & Sons, Ltd.</P>

KAI1/CD82 decreases Rac1 expression and cell proliferation through PI3K/Akt/mTOR pathway in H1299 lung carcinoma cells

Choi, Un-Jong,Jee, Bo-Keun,Lim, Young,Lee, Kweon-Haeng John Wiley Sons, Ltd. 2009 CELL BIOCHEMISTRY AND FUNCTION Vol.27 No.1

<P>Although the KAI1/CD82 protein has been reported to inhibit cell metastasis in many studies, its mechanism of action has not yet been fully elucidated. In the present study, we investigated the possible effects of KAI1/CD82 on the metastatic phenotype in H1299 lung carcinoma cells. These studies were based on the pivotal role that the acquisition of motile phenotype plays on the initial steps of metastasis. KAI1/CD82-mediated morphological changes were observed using phase contrast microscopy. We report here, that a KAI1/CD82-induced phenotypic change was involved in the decrease of Rac1 expression and GTPase activity. However, we found that KAI1/CD82 did not regulate Rac1 mRNA levels. This suggests the existence of another regulatory mechanism of Rac1 protein maturation or activation. To identify the signaling pathway of Rac1 regulation, we investigated the PI3K/Akt/mTOR pathway, since the PI3K/Akt pathway regulates Rac1 activation and mTOR is known to play a regulatory role in protein translation. H1299/CD82-transfectants showed lower mTOR expression and cell growth than the control group. The data obtained from this study suggested that KAI1/CD82 decreased the metastatic phenotype of H1299 lung carcinoma cells by down-regulating Rac1 expression through the PI3K/Akt/mTOR pathway. Copyright © 2008 John Wiley & Sons, Ltd.</P>