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The objective of this study is to enhance the Ad hoc On-demand Distance Vector (AODV) routing protocol, a representative mobile ad hoc network environment routing protocol. In the existing AODV protocol, dynamic topology changes due to node mobility cause frequent route failures and network instability. We herein propose a local repair scheme to re-establish routes when links are broken and a dual-path routing scheme to improve network stability by employing alternate routes. After comparing the total data processing volumes, average packet end-to-end delays, numbers of connection pairs, energy consumptions, and numbers of generated packets of the enhanced AODV protocols, we discuss the optimal operating conditions for each scheme. We also investigated the performance variations resulting from changing the number of nodes and node mobility, using an NS-2 simulator. The results revealed that the dual-path protocol generally performs the best and improves the packet end-to-end delay by up to 45 %.

Conduction noise attenuation by composite sheets of high magnetic and dielectric loss has been analyzed by using electromagnetic field simulator which employs finite element method. The simulation model consists of microstrip line with planar input/output ports and noise absorbers (magnetic composite sheets containing iron flake particles as absorbent fillers). Reflection and transmission parameters and power loss are calculated as a function of frequency with variation of sheet size and thickness. The simulated value is in good agreement with measured one and it is demonstrated that the proposed simulation technique can be effectively used in the design and characterization of noise absorbing materials in the RF transmission lines.

Morphology of periodical nanoscale pores in AAO templates has been studied in relation with anodizing process, focusing on the growth of nickel nanowires by electrochemical deposition. The AAO templates were prepared by a two-step anodization process. The high purity aluminum plates were anodized in oxalic acid aqueous solution with variation of cell voltage. The pore size and interpore distance both increase with the applied potential. During the post treatment of barrier thinning, small-size pores with split-up structure at the tips are observed due to current-limited anodizing process (decreasing cell potential). The rectifying properties of the barrier layer allow the pores to be filled by nickel by AC electrodeposition. The nickel nanowires array shows the ferromagnetic properties with a preferred magnetic orientation along the wire axis. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Microwave absorbing properties of ferrite-epoxy composite (absorbing layer) attached on the carbon fiber polymer composite (reflective substrate) are analyzed on the basis of wave propagation theory. A modified equation for wave-impedance-matching at the front surface of absorbing layer including the effect of electrical properties of the quasi-conducting substrate is proposed. Based on this analysis, the frequency and layer dimension that produce zero-reflection can be estimated from the intrinsic material properties of the absorbing layer and the substrate. It is demonstrated that the microwave reflectivity of carbon fiber composite has a strong influence on the microwave absorbance of front magnetic layer. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Nickel nanowire arrays are fabricated by electrochemical deposition in highly ordered nanosized pores in AAO (anodized aluminum oxide) templates, and their static and high-frequency noise absorbing properties have been investigated. Using the channelled AAO templates, a nickel nanowires array was fabricated by DC electrodeposition. Magnetic hysteresis was observed with a coercivity of 250∼ 300 Oe depending on the field orientation with respect to wire axis. Noise absorbing properties of the nickel nanowires array was measured using the microstrip line. S 11 parameter increases with frequency and reaches a saturated value of about -10 dB. The reflected power (about 10%) is much less than that of nickel thin film (about -3 dB), which is due to higher in-plane electrical resistance of the nanowire array structure. S 21 decreases with frequency and has a value of -3 dB at 2 GHz. The attenuation of conduction noise through microstrip line is due to the magnetic loss of individual nickel nanowires. Power absorption of the Ni nanowire array was estimated to be 50% in the frequency range above 2 GHz.

DMKP-3 is a Drosophila dual-specificity phosphatase, which has high substrate specificity for Drosophila extracellular signal-regulated kinases (DERK). By in vitro reconstitution experiments, we found that DERK activates DMKP-3. Moreover, DMKP-3 was specifically activated by the addition of DERK but not by DJNK, Dp38, or Sevenmaker DERK D334N, a DMKP-3- binding mutant. The phosphatase activity of DMKP-3-R56A/R57A, a DERK-binding mutant, was not increased by DERK. Significantly, mammalian MKP-3 was also found to be activated by DERK. This cross-reactivity suggests a high level of conservation of the activation mechanism of ERK-specific phosphatases in Drosophila and mammals. When DMKP-3 was co-expressed with DERK in Drosophila Schneider cells, DMKP-3 protein levels increased, but this was not observed for the co-expressions of DJNK or Dp38. The stabilizations of the DERK binding mutants (DMKP-3-RR and DMKP-3-CA-RR) were not increased by DERK co-expression. Our results suggest that DERK specifically regulates DMKP-3 in terms of its enzyme activity and protein stability, and that direct protein-protein interaction is an essential aspect of this regulation.

Neuregulin-1 (NRG1) and its receptor ErbB4 influence several processes of neurodevelopment, but the mechanisms regulating this signalling in the mature brain are not well known. DISC1 is a multifunctional scaffold protein that mediates many cellular processes. Here we present a functional relationship between DISC1 and NRG1-ErbB4 signalling in mature cortical interneurons. By cell type-specific gene modulation in vitro and in vivo including in a mutant DISC1 mouse model, we demonstrate that DISC1 inhibits NRG1-induced ErbB4 activation and signalling. This effect is likely mediated by competitive inhibition of binding of ErbB4 to PSD95. Finally, we show that interneuronal DISC1 affects NRG1-ErbB4-mediated phenotypes in the fast spiking interneuron-pyramidal neuron circuit. Post-mortem brain analyses and some genetic studies have reported interneuronal deficits and involvement of the DISC1, NRG1 and ErbB4 genes in schizophrenia, respectively. Our results suggest a mechanism by which cross-talk between DISC1 and NRG1-ErbB4 signalling may contribute to these deficits., Neuregulin-1 and DISC1 signalling pathways have both been linked to neurodevelopment and schizophrenia. Here, Seshadri et al. demonstrate that DISC1 negatively regulates NRG1-induced ErbB4 signalling in adult cortical interneurons both in vitro and in vivo, possibly via competitive binding to PSD95.

A partial C-terminal cDNA sequence of a novel Drosophila mitogen-activated protein kinase phosphatase (MKP), designated DMKP-3, was identified from an epitope expressed sequence tag database, and the missing N-terminal cDNA fragment was cloned from a Drosophila cDNA library. DMKP-3 is a protein of 411 amino acids, with a calculated molecular mass of 45.8kDa; the deduced amino acid sequence is most similar to that of mammalian MKP-3. Recombinant DMKP-3 produced in Escherichia coli retained intrinsic tyrosine phosphatase activity. In addition, DMKP-3 specifically inhibited extracellular-signal-regulated kinase (ERK) activity, but was without a significant affect on c-Jun N-terminal kinase (JNK) and p38 activities, when it was overexpressed in Schneider cells. DMKP-3 interacted specifically with Drosophila ERK (DERK) via its N-terminal domain. In addition, DMKP-3 specifically inhibited Elk-1-dependent trans-reporter gene expression in mammalian CV1 cells, and dephosphorylated activated mammalian ERK in vitro. DMKP-3 is uniquely localized in the cytoplasm within Schneider cells, and gene expression is tightly regulated during development. Thus DMKP-3 is a Drosophila homologue of mammalian MKP-3, and may play important roles in the regulation of various developmental processes.

Saccharomyces cerevisiae Ste5 is a scaffold protein that recruits many pheromone signaling molecules to sequester the pheromone pathway from other homologous mitogen-activated protein kinase pathways. G1 cell cycle arrest and mating are two different physiological consequences of pheromone signal transduction and Ste5 is required for both processes. However, the roles of Ste5 in G1 arrest and mating are not fully understood. To understand the roles of Ste5 better, we isolated 150 G1 cell cycle arrest defective STE5 mutants by chemical mutagenesis of the gene. Here, we found that two G1 cell cycle arrest defective STE5 mutants (ste5MD248Vand ste5delta-776) retained mating capacity. When overproduced in a wild-type strain, several ste5 mutants also showed different dominant phenotypes for G1 arrest and mating. Isolation and characterization of the mutants suggested separable roles of Ste5 in G1 arrest and mating of S. cerevisiae. In addition, the roles of Asp-248 and Tyr-421, which are important for pheromone signal transduction were further characterized by site-directed mutagenesis studies.Key words: Ste5, Saccharomyces cerevisiae, signal transduction, mating, G1 cell cycle arrest.

DOC-2/DAB-2 interacting protein (Dab2IP) is a GTPase activating protein that binds to Disabled-1, a cytosolic adapter protein involved in Reelin signaling and brain development. Dab2IP regulates PI3K-AKT signaling and is associated with metastatic prostate cancer, abdominal aortic aneurysms and coronary heart disease. To date, the physiological function of Dab2IP in the nervous system, where it is highly expressed, is relatively unknown. In this study, we generated a mouse model with a targeted disruption of Dab2IP using a retrovirus gene trap strategy. Unlike reeler mice, Dab2IP knock-down mice did not exhibit severe ataxia or cerebellar hypoplasia. However, Dab2IP deficiency produced a number of cerebellar abnormalities such as a delay in the development of Purkinje cell (PC) dendrites, a decrease in the parallel fiber synaptic marker VGluT1, and an increase in the climbing fiber synaptic marker VGluT2. These findings demonstrate for the first time that Dab2IP plays an important role in dendrite development and regulates the number of synapses in the cerebellum.

Bacillus endophyticus 2102 is an endospore-forming, plant growth-promoting rhizobacterium isolated from a hypersaline pond in South Korea. Here we present the draft sequence of B. endophyticus 2102, which is of interest because of its potential use in the industrial production of algaecides and bioplastics and for the treatment of industrial textile effluents.

Dab2ip (DOC-2/DAB2 interacting protein) is a member of the Ras GTPase-activating protein (GAP) family that has been previously shown to function as a tumor suppressor in several systems. Dab2ip is also highly expressed in the brain where it interacts with Dab1, a key mediator of the Reelin pathway that controls several aspects of brain development and function. We found that Dab2ip is highly expressed in the developing cerebral cortex, but that mutations in the Reelin signaling pathway do not affect its expression. To determine whether Dab2ip plays a role in brain development, we knocked down or over expressed it in neuronal progenitor cells of the embryonic mouse neocortex using in utero electroporation. Dab2ip down-regulation severely disrupts neuronal migration, affecting preferentially late-born principal cortical neurons. Dab2ip overexpression also leads to migration defects. Structure-function experiments in vivo further show that both PH and GRD domains of Dab2ip are important for neuronal migration. A detailed analysis of transfected neurons reveals that Dab2ip down- or up-regulation disrupts the transition from a multipolar to a bipolar neuronal morphology in the intermediate zone. Knock down of Dab2ip in neurons ex-vivo indicates that this protein is necessary for proper neurite development and for the expression of several major neuronal microtubule associated proteins (MAPs), which are important for neurite growth and stabilization. Thus, our study identifies, for the first time, a critical role for Dab2ip in mammalian cortical development and begins to reveal molecular mechanisms that underlie this function.

Paenibacillus polymyxa is an endospore-forming Gram-positive soil bacterium that is well-known for its ability to promote plant growth. Here we report the draft genome sequence of P. polymyxa ATCC 842 T , the type strain of the species P. polymyxa , and the family Paenibacillaceae . The P. polymyxa genome contains a repertoire of biosynthetic genes for antibiotics and hydrolytic enzymes that account for its beneficial effects in the rhizosphere to the host plants it associates with.

This paper presents a method of reducing the feedback delay time of DWA(Data Weighted Averaging) used in sigma-delta modulators. The delay time reduction results from the elimination of the latch at the quantizer output and also from the falling edge operation. The designed sigma-delta modulator improves the timing margin about 16%. The sub-circuits of sigma-delta modulator such as SC(Switched Capacitor) integrator, 9-level quantizer, comparator, and DWA are designed with the non-ideal characteristics taken into account. The sigma-delta modulator has a maximum SNR (Signal to Noise Ratio) of 84 dB or 13 bit resolution., {"references":["I. Galton, \"Delta-sigma data conversion in wireless transceivers,\" IEEE\nTransaction on Microwave Theory and Techniques, vol. 50, no. 1, pp.\n302-316, Jan. 2002.","A. Marques, V. Peluso, M. S. Steyaert, W. M. Sansen, \"Optimal parameter\nfor ΣΔ modulator topologies,\" IEEE Transaction on Circuit and Systems,\nvol. 45, no. 9, pp. 1232-1241, Sep. 1998.","B. P. Brandt, B. A. Wooley, \"A 50MHz multibit sigma-delta modulator\nfor 12-b 2-MHz A/D conversion,\" IEEE J. Solid-State Circuit, vol. 26, pp.\n1746-1756, Dec. 1999","B. W. Cho, P. Choi, J. R. Choi, D. H. Kwon, B. K. Sohn, \"A second-order\nsigma-delta modulator with a gain scaling of ADC and simple multibit\nDAC,\" IEICE Trans. Fundamentals, vol. E83-A, no. 6, Jun. 2000.","E. N. Aghdam, P. Benabes, and J. Abbasszadeh, \"A completely first order\nand tone free partitioned data weighted averaging technique used in a\nmultibit delta sigma modulator,\" in Proc. IEEE ECCTD, pp. 53-56, Oct.\n2009.","J. Grilo, I. Galton, K. Wang, and R. Montemayor, \"A 12-mW ADC\ndelta-sigma modulator with 80dB of dynamic range integrated in a\nsinglel-chip bluetooth transceiver,\" IEEE J. Solid State Circuit, vol.\nsc-37, pp. 271-278, Mar. 2002.","Y. Greets, M. Steyaert, and W. Sansen, \"A high performance ΔΣ CMOS\nADC,\" IEEE J. Solid-State Circuit, vol. SC-35, pp. 1829-1840, Dec.\n2000.","F. Chen, B. Leung, \"A high resolution multibit sigma-delta modulator\nwith individual level averaging,\" IEEE J. Solid-State Circuits, vol. SC-30,\npp. 453-460, Apr. 1995.","M. R. Miller, C. S. Petrie, \"A multibit sigma-delta ADC for multimode\nreceivers,\" IEEE J. Solid-State Circuit, vol. SC-38, pp. 475-482, Mar.\n2003.\n[10] A. A. Hamoui and K. Martin, \"Linearity enhancement of multibit ΔΣ\nmodulator using pseudo data-weighted averaging,\" in Proc. IEEE ISCAS,\nPP. IIII 285-288, May. 2002."]}

A transceiver for ADSL systems contains an interpolated combfilter, halfband filters, oversampling sigma delta modulator, a current steering DAC and an analog filter. The circuit complexity of the architecture makes it necessary to use behavioral models to determine the system features. For this reason, we need a specific behavioral simulation environment using the Matlab program. The Matlab is crucial for these circuits to be rapidly incorporated in larger systems, in particular in the context of mixed-signal-test schemes. Design trade-off among the blocks has also been discussed. The design methodology is based on behavioral design and CMOS process.

This paper presents a multi-bit sigma-delta data converter with third-order 3-bit topology. This converter can achieve high resolution with a lower order modulator and lower oversampling ratio than single-bit converter. The dynamic element matching (DEM) algorithm is designed in such a way as to minimize delay within the feedback loop of the sigma-delta ADC. The behavioral model is used to simulate the designed sigma-delta data converter. The designed ADC achieves 14-bit resolution, a peak SNR of 87dB within a 1 MHz signal baseband at a clock rate of 50MHz.

Kluyveromyces marxianus is a thermotolerant yeast that has been explored for potential use in biotechnological applications, such as production of biofuels, single-cell proteins, enzymes, and other heterologous proteins. Here, we present the high-quality draft of the 10.9-Mb genome of K. marxianus var. marxianu s KCTC 17555 (= CBS 6556 = ATCC 26548).

Bacillus siamensis KCTC 13613 T , a novel halophilic Bacillus species isolated from a salted Thai food, produced antimicrobial compounds against plant pathogens and promoted plant growth by volatile emission. We determined the 3.8-Mb genome sequence of B. siamensis KCTC 13613 T to reveal the plant-beneficial effect at the genomic level.

Paenibacillus peoriae is a potentially plant-beneficial soil bacterium and is a close relative to Paenibacillus polymyxa, the type species of the genus Paenibacillus. Herein, we present the 5.77-Mb draft genome sequence of the P. peoriae type strain with the aim of providing insight into the genomic basis of plant growth-promoting Paenibacillus species.

This paper has been the analysis of passive devices in Si RF and microwave. Multilevel monolithic 3D inductors implemented in a standard CMOS technology are presented. Since on-chip inductors are constrained to be planar, the typical solution is to form a spiral. Proposed inductors are composed of 3D structures requiring no extra processing steps. Inductances are higher in increasing the mutual inductance besides the self-inductance. In this reason, this structure gives rise to a quality factor Q and a inductance using 3D geometry in small areas.

In order to develop wide-band noise absorbers with a focused design for low frequency performance, this study investigates hybrid absorbers that are composed of conductive indium-tin-oxide (ITO) thin film and magnetic composite sheets. The ITO films prepared via reactive sputtering exhibit a typical value of electrical resistivity of ≃10−4 Ω m. Rubber composites with flaky Fe-Si-Al particles are used as the magnetic sheet with a high permeability and high permittivity. For the ITO film with a low surface resistance and covered by the magnetic sheet, approximately 90% power absorption can be obtained at 1 GHz, which is significantly higher than that of the original magnetic sheet or ITO film. The high power absorption of the hybrid absorber is attributed to the enhanced ohmic loss of the ITO film through increased electric field strength bounded by the upper magnetic composite sheet. However, for the reverse layering sequence of the ITO film, the electric field experienced by ITO film is very weak due to the electromagnetic shielding by the under layer of magnetic sheet, which does not result in enhanced power absorption.

The Drosophila extracellular signal-regulated kinase (DERK) mitogen-activated protein kinase (MAPK) is involved in the regulation of multiple differentiation and developmental processes. Tight control of MAPK activity is critical for normal cell behaviour. We identified a novel Drosophila MAPK phosphatase (DMKP) cDNA from the expressed-sequence-tag database and characterized it. Analysis of the nucleotide sequence revealed an open reading frame encoding the 203-amino acid protein, with a calculated molecular mass of 23kDa, which has a high amino acid sequence similarity with ‘VH1-like’dual-specific phosphatases at the broad region near the catalytic sites. The expression of DMKP mRNA occurs from the late larval stages to adulthood in Drosophila development. The recombinant DMKP protein produced in yeast retained its phosphatase activity. When expressed in Schneider cells, DMKP dose-dependently inhibited DERK and Drosophila c-Jun N-terminal kinase activities with high selectivity towards DERK. However, DMKP did not have any affect on Drosophila p38 activity. When DMKP was expressed in yeast, it down-regulated the fus1-lacZ trans-reporter gene of the pheromone MAPK pathway without any significant effect on the high-osmolarity-glycerol-response pathway.

For the aim of wide-band noise absorbers with a special design for low frequency performance, this study proposes conductive indium-tin oxide (ITO) thin films as the absorbent materials in microstrip line. ITO thin films were deposited on the polyimide film substrates by rf magnetron cosputtering of In2O3 and Sn targets. The deposited ITO films show a typical value of electrical resistivity (∼10−4 Ω m) and sheet resistance can be controlled in the range of 20–230 Ω by variation in film thickness. Microstrip line with characteristic impedance of 50 Ω was used for determining their noise absorbing properties. It is found that there is an optimum sheet resistance of ITO films for the maximum power absorption. Reflection parameter (S11) is increased with decrease in sheet resistance due to impedance mismatch. On the while, transmission parameter (S21) is decreased with decrease in sheet resistance due to larger Ohmic loss of the ITO films. Experimental results and computational prediction show that the optimu...

135 통신저자:김 우 식 대전광역시 서구 가수원동 685 건양대학교 의과대학 정형외과학교실 Tel:042-600-6905, 9120.Fax:042-545-2373 E-mail:woosikkim@hanmail.net *본 논문의 요지는 2004년도 제48차 대한정형외과학회 추계학술대회에서 발 표되었음. Address reprint requests to:Woo-Sik Kim, M.D. Department of Orthopaedic Surgery, Konyang University College of Medicine, 685 Gasoowon-dong, Seo-Ku, Daejeon 302-718, Korea Tel:82-42-600-6905, 9120.Fax:82-42-545-2373 E-mail:woosikkim@hanmail.net 고에너지 손상에 의한 대퇴골 전자하부 분쇄 골절의 수술적 치료

Purpose : The aim of this study was to determine the effect of alcohol on the expression of VEGF-A, PEDF, and VEGFR-2 in human osteoblasts. Materials and Methods : Human osteoblasts primarily derived from the intertrochanteric region of the femur with osteonecrosis and fracture (control) were cultured with alcohol (0, 20, 100, 150 mM). The level of cell proliferation and the expression levels of VEGF-A mRNA, PEDF mRNA, and VEGFR-2 mRNA was evaluated according to the alcohol concentrations and the culture periods. Results : Osteoblasts with the added alcohol showed an early increase in cell population, and a subsequent decrease or steady level thereafter compared with those without alcohol (p＜0.05). The osteoblasts in the osteonecrosis group showed an increase in VEGF-A mRNA and PEDF mRNA expression at high alcohol concentrations (100, 150 mM), resulting in an decreased VEGF-A/PEDF ratio, while those in the control group showed an increase in VEGF-A mRNA expression and a decrease in PEDF mRNA expression, resulting in an increase in the VEGF-A/PEDF ratio (p＜0.05). Conclusion : Alcohol stops the proliferation of osteoblasts and can cause an imbalance between VEGF-A and PEDF, thereby inhibiting the neovascularization of osteonecrosis.

목 적: 동측 대퇴골 및 경골 간부 골절이 동반된 슬관절 불안정성의 발생 빈도와 유형을 대퇴골 간부 단독 골절 및 경골 간부 단독 골절 환자의 경우와 비교 분석하고, 그 중요성을 알아보고자 한다. 대상 및 방법: 2000년 2월부터 2004년 4월까지 치료받은 대퇴골 간부 단독 골절 80예, 경골 간부 단독 골절 176예, 동측 대퇴골 및 경골 간부 골절 23예의 총 279명을 대상으로 하였다. 이학적 검사, 단순 방사선 stress 사진 및 자기 공명 영상을 기초로 각각의 경우에서 슬관절 불안 정성 유무를 확인하였으며, 각각에 대해 슬관절 불안정성의 빈도, 진단 시기, 골유합 기간 및 최종 추시 시 Hospital for Special Surgery (HSS) 슬관절 점수를 이용하여 임상적 결과를 비교 분석하였다. 결 과: 슬관절 불안정성의 빈도는 대퇴골 간부 단독 골절의 경우는 6.3%였고, 경골 간부 단독 골절은 9.7%였으며, 동측 대퇴골 및 경골 간 부 골절은 30.4%였다. 불안정성의 진단 시기, 골유합 기간 및 최종 추시 시 HSS 슬관절 점수는 대퇴골 간부 단독 골절의 경우는 각각 평균 9.2개월, 평균 4.7개월, 평균 65점이었으며, 경골 간부 단독 골절의 경우는 각각 평균 9.1개월, 평균 4.2개월, 평균 69점이었고, 동측 대퇴골 간부 골절과 경골 간부 단독 골절의 경우는 각각 평균 8.7개월, 대퇴골은 평균 5.3개월, 경골은 평균 4.7개월, 평균 57점이었다. 결 론: 동측 대퇴골 및 경골 간부 골절 환자에서 수상 당시 자기 공명 영상 촬영을 고려해야 하며, 조기에 슬관절 불안정성에 대한 치료 계획 을 세우는 것이 필요할 것으로 생각한다.