Measurement And Modeling Of Short Copper Cables For Ultra-wideband Communication

High-speed communication using the copper network, originally installed for telephony, is one of the dominant Internet access techniques. Several variants of a technology referred to as digital subscriber line (DSL) have been developed, standardized and installed during the last two decades. Essentially, DSL achieves high rates by exploiting wide bands of the copper cable channel. The shorter the cable, the wider the band that can be used efficiently for communication. Current DSL standards foresee the use of bands up to 30MHz. Cable properties have been studied by means of measurements, characterization and modeling up to frequencies of 30MHz. Recent investigations have shown that it is feasible both from technical and from economical point of view to exploit very short cables (up to 200m) even further and use bands above 30MHz. A prerequisite for further evaluation and the design of such ultra-wideband copper (UWBC) systems is the extension of existing cable models to higher frequencies. This paper presents wideband measurement results of insertion loss and crosstalk coupling in a 10-pair cable of various length values for frequencies up to 200MHz. We compare the results with extrapolations of cable models that are established in the 30MHz-range.6390Chen, W.Y., (1998) DSL: Simulation Techniques and Standards Development for Digital Subscriber Line Systems, , Macmillan Technical Publishing, ISBN 1-57870-017-5G.selt: Updated issues list for G.selt (2004) ITU-T Temporary Document SS U09, , ITU-TAsymmetric digital subscriber line (ADSL) transceivers (1999) ITU Recommendation G.992.1, , ITU-T, JuneAsymmetric digital subscriber line (ADSL) transceivers (1999) ITU Recommendation G.992.2, , ITU-T, JuneAsymmetric digital subscriber line (ADSL) extended bandwidth (ADSL2+) (2005) ITU Recommendation G.992.5, , ITU-TStarr, T., Cioffi, J.M., Silverman, P., (1998) Understanding Digital Subscriber Line Technology, , Prentice Hall, Englewood CliffsDedieu, H., The copper channel - Loop charactersitics and models (2005) Fundamentals of DSL Technology, , ch. ISBN 0849319137, AUERBACHVan Der Brink, R.F.M., (1998) Cable Reference Models for Simulating Metallic Access Networks, , Permanent Document TM6(97), ETSI STC TM6, Luleå, Sweden, JunePaul, C.R., (1994) Analysis of Multiconductor Transmission Lines, , Wiley, ISBN 0-471-02080-XCook, J.W., (1996) Parametric Modelling of Twisted Pair Cables for VDSL, , Temporary Document TD22, ETSI STC TM6, Vienna, Austria, MarVan Der Brink, R.F.M., (1997) Measurements and Models on Dutch Cables, , Temporary Document TD15, ETSI STC TM6, Tel Aviv, Israel, MarPollakowski, M., (1996) DTAG Cables Transmission Characteristics, , Temporary Document TD40, ETSI STC TM6, Vienna, Austria, MarPythoud, F., (1998) Model of Swiss Access Network Cables, , Temporary Document TD48, ETSI STC TM6, Madrid, Spain, JanHeylen, L., Musson, J., (1999) Cable Models Predict Physically Impossible Behavior in Time Domain, , Temporary Document TD08, ETSI STC TM6, Amsterdam, Netherlands, NovMusson, J., (1998) Maximum Likelihood Estimation of the Primary Parameters of Twisted Pair Cables, , Temporary Document TD06, ETSI STC TM6, Madrid, Spain, SeptBoets, P., Zekri, M., Van Biesen, L., Bostoen, T., Pollet, T., On the identification of cables for metallic access networks (2001) 18th IEEE Instrumentation and Measurement Technology Conference IMTC2001, 2, pp. 1348-1353. , Budapest, Hungary, MayBostoen, T., Boets, P., Zekri, M., Van Biesen, L., Pollet, T., Rabijns, D., Estimation of the transfer function of the access network by means of one-port scattering parameter measurements at the central office (2002) IEEE Journal on Selected Areas in Communication, 20, pp. 936-948. , JuneVery-high-bit-rate Digital Subscriber Line (VDSL) metallic interface part 1: Functional requirement and common specification (2001) T1E1.4/2000-009R3, , ANSI T1E1.4, FebVan Der Brink, R.F.M., (2001) Laboratory Performance Tests for XDSL Systems, , Permanent Document TM6(98)10, ETSI STC TM6, Sophia Antipolis, France, FebValenti, C., NEXT and FEXT models for twisted-pair North American loop plant (2002) IEEE Journal on Selected Areas in Communication, 20, pp. 893-900. , JuneNedev, N.H., McLaughlin, S., Cook, J.W., Wideband UTP cable measurements and modelling for MIMO systems (2004) Proc. European Signal Processing Conf. EUSIPCO 2004, , (Vienna, Austria), SeptMagesacher, T., Henkel, W., Tauböck, G., Nordström, T., Cable measurements supporting xDSL technologies (2002) Journal E&i Elektrotechnik und Informationstechnik, 199, pp. 37-43. , FebMagesacher, T., Ödling, P., Börjesson, P.O., Henkel, W., Nordström, T., Zukunft, R., Haar, S., On the capacity of the copper cable channel using the common mode (2002) Proc. IEEE Global Telecommun. Conf. GLOBECOM 2002, , (Taipei, Taiwan), NovTomita, N., Ohmura, M., Low-frequency crosstalk loss characteristics of balanced cables (1989) Electron. Commun. Japan, Part 1, 72 (3), pp. 95-105Goedbloed, J.J., Aspects of EMC at the equipment level (1997) Proc. 12th Intl. Symp. Electromagn. Compat., pp. 23-38. , (Zurich, Switzerland), FebWerner, J.J., The HDSL environment (1991) IEEE Journal on Selected Areas in Communication, 9, pp. 785-800. , AugConte, R.A., A crosstalk model for balanced digital transmission in multipair cables (1986) AT&T Tech. J., 65, pp. 41-59. , May-JunSchutt-Aine, J.E., High-frequency characterization of twisted-pair cables (2001) IEEE Trans. on Commun., 49, pp. 598-601. , AprGresh, P.A., Physical and transmission characteristics of customer loop plant (1969) The Bell System Technical Journal, 48, pp. 3337-3385. , DecManhire, L.M., Physical and transmission characteristics of customer loop plant (1978) The Bell System Technical Journal, 57, pp. 35-39. , JanPierce, S.B., Crosstalk in twisted pair circuits (1986) Proc. Intl. Wire and Cable Symp., pp. 349-354Fung, A., Lee, L.S., Falconer, D.D., A facility for near end crosstalk measurements on ISDN subscriber loops (1989) Proc. IEEE Global Telecommun. Conf, , paper 54.

Observation of Umklapp processes in non-crystalline materials

Umklapp processes are known to exist in cristalline materials, where they control important properties such as thermal conductivity, heat capacity and electrical conductivity. In this work we report the provocative observation of Umklapp processes in a non-periodical system, namely liquid Lithium. The lack of a well defined periodicity seems then not to prevent the existence of these scattering processes mechanisms provided that the local order of the systems i.e. the maxima of the static structure factor supply the equivalent of a reciprocal lattice vector in the case of cristalline materials.Comment: 13 pages P

Coupling Constant pH Molecular Dynamics with Accelerated Molecular Dynamics

An extension of the constant pH method originally implemented by Mongan et al. (J. Comput. Chem.2004, 25, 2038−2048) is proposed in this study. This adapted version of the method couples the constant pH methodology with the enhanced sampling technique of accelerated molecular dynamics, in an attempt to overcome the sampling issues encountered with current standard constant pH molecular dynamics methods. Although good results were reported by Mongan et al. on application of the standard method to the hen egg-white lysozyme (HEWL) system, residues which possess strong interactions with neighboring groups tend to converge slowly, resulting in the reported inconsistencies for predicted pKa values, as highlighted by the authors. The application of the coupled method described in this study to the HEWL system displays improvements over the standard version of the method, with the improved sampling leading to faster convergence and producing pKa values in closer agreement to those obtained experimentally for the more slowly converging residues

Prognostic significance of CD44s expression in resected non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>CD44s is a cell adhesion molecule known to mediate cellular adhesion to the extracellular matrix, a prerequisite for tumor cell migration. CD44s plays an important role in invasion and metastasis of various cancers. In the present study, we sought to determine whether CD44s is involved in clinical outcomes of patients with resected non-small cell lung cancer (NSCLC).</p> <p>Methods</p> <p>Using immunohistochemical staining, we investigated CD44s protein expression using tissue array specimens from 159 patients with resected NSCLC (adenocarcinoma (AC; <it>n </it>= 82) and squamous cell carcinoma (SCC; <it>n </it>= 77). Additionally, the immunoreactivity of cyclooxygenase (COX)-2 was also studied. The clinicopathological implications of these molecules were analyzed statistically.</p> <p>Results</p> <p>High CD44s expression was detected more frequently in NSCLC patients with SCC (66/72; 91.7%) than in those with AC histology (<it>P <</it>0.001). Additionally, high CD44s expression was significant correlated with more advanced regional lymph node metastasis (<it>P </it>= 0.021). In multivariate analysis of survival in NSCLC patients with AC histology, significant predictors were lymph node metastasis status (<it>P </it>< 0.001), high-grade tumor differentiation (<it>P = </it>0.046), and high CD44s expression (<it>P = </it>0.014). For NSCLC patients with SCC histology, the significant predictor was a more advanced tumor stage (<it>P = </it>0.015). No significant association was found between CD44s and clinical outcome (<it>P </it>= 0.311).</p> <p>Conclusions</p> <p>High CD44s expression was a negative prognostic marker with significance in patients with resected NSCLC, particularly those with AC histology, and was independent of tumor stage.</p

How predictive is the MMSE for cognitive performance after stroke?

Cognitive deficits are commonly observed in stroke patients. Neuropsychological testing is time-consuming and not easy to administer after hospital discharge. Standardised screening measures are desirable. The Mini-Mental State Examination (MMSE) is the test most widely applied to screen for cognitive deficits. Despite its broad use, its predictive characteristics after stroke have not been exhaustively investigated. The aim of this study was to determine whether the MMSE is able to adequately screen for cognitive impairment and dementia after stroke and whether or not the MMSE can predict further deterioration or recovery in cognitive function over time. To this end, we studied 194 first-ever stroke patients without pre-stroke cognitive deterioration who underwent MMSEs and neuropsychological test batteries at 1, 6, 12, and 24 months after stroke. The MMSE score 1 month after stroke predicted cognitive functioning at later follow-up visits. It could not predict deterioration or improvement in cognitive functioning over time. The cut-off score in the screening for 1 cognitive disturbed domain was 27/28 with a sensitivity of 0.72. The cut-off score in the screening for at least 4 impaired domains and dementia were 26/27 and 23/24 with a sensitivity of 0.82 and 0.96, respectively. The results indicated that the MMSE has modest qualities in screening for mild cognitive disturbances and is adequate in screening for moderate cognitive deficits or dementia in stroke patients 1 month after stroke. Poor performance on the MMSE is predictive for cognitive impairment in the long term. However, it cannot be used to predict further cognitive deterioration or improvement over time

Epigenetic Silencing of Host Cell Defense Genes Enhances Intracellular Survival of the Rickettsial Pathogen Anaplasma phagocytophilum

Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum–infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1) expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease

Balance perturbation system to improve balance compensatory responses during walking in old persons

Ageing commonly disrupts the balance control and compensatory postural responses that contribute to maintaining balance and preventing falls during perturbation of posture. This can lead to increased risk of falling in old adults (65 years old and over). Therefore, improving compensatory postural responses during walking is one of the goals in fall prevention programs. Training is often used to achieve this goal. Most fall prevention programs are usually directed towards improving voluntary postural control. Since compensatory postural responses triggered by a slip or a trip are not under direct volitional control these exercises are less expected to improve compensatory postural responses due to lack of training specificity. Thus, there is a need to investigate the use balance perturbations during walking to train more effectively compensatory postural reactions during walking