Constructions for finite-state codes

A class of codes called finite-state (FS) codes is defined and investigated. These codes, which generalize both block and convolutional codes, are defined by their encoders, which are finite-state machines with parallel inputs and outputs. A family of upper bounds on the free distance of a given FS code is derived from known upper bounds on the minimum distance of block codes. A general construction for FS codes is then given, based on the idea of partitioning a given linear block into cosets of one of its subcodes, and it is shown that in many cases the FS codes constructed in this way have a d sub free which is as large as possible. These codes are found without the need for lengthy computer searches, and have potential applications for future deep-space coding systems. The issue of catastropic error propagation (CEP) for FS codes is also investigated

Filamentation of Campylobacter in broth cultures

The transition from rod to filamentous cell morphology has been identified as a response to stressful conditions in many bacterial species and has been ascribed to confer certain survival advantages. Filamentation of Campylobacter jejuni was demonstrated to occur spontaneously on entry in to stationary phase distinguishing it from many other bacteria where a reduction in size is more common. The aim of this study was to investigate the cues that give rise to filamentation of C. jejuni and C. coli and gain insights into the process. Using minimal medium, augmentation of filamentation occurred and it was observed that this morphological change was wide spread amongst C. jejuni strains tested but was not universal in C. coli strains. Filamentation did not appear to be due to release of diffusible molecules, toxic metabolites, or be in response to oxidative stress in the medium. Separated filaments exhibited greater intracellular ATP contents (2.66 to 17.4 fg) than spiral forms (0.99 to 1.7 fg) and showed enhanced survival in water at 4oC and 37oC compared to spiral cells. These observations support the conclusion that the filaments are adapted to survive extra-intestinal environments. Differences in cell morphology and physiology need to be considered in the context of the design of experimental studies and the methods adopted for the isolation of campylobacters from food, clinical and environmental sources

System Identification and Seismic Performance Evaluation of Earth Dams

A system identification technique is developed to provide dynamic properties of earth dams from their seismic records. The technique is utilized to assess the capabilities and limitation of analytical models in terms of dynamic nonlinear constitutive relationships as well as damping. The technique is based on the least square method using Gaussian hypothesis. Earth dams are modeled as a three-dimensional nonhomogeneous visco-elasto-plastic soil structure. The forward problem is solved using a Galerkin-Ritz formulation in which the solution is expanded using basis function, which is selected to be the eigenmodes. The spatial variation of the excitation is considered by using global shape functions defined on the boundary domain to interpolate the input motion on the dam boundaries using recorded motion at discrete locations. The constitutive model is used to accommodate the nonlinear path dependent behavior of the dam material as well as coupling between different constituent of the soil mixture. The model is implemented using Druker-Prager multi-yield surface model and linear Kelvin-Voigt model. Application to instrumented dams, in recent earthquake, showed significant match between the recorded response and the optimal estimated response

Anti-Tumour Effect In Vitro of Lymphocytes and Macrophages from Mice Treated with Corynebacterium Parvum

Cells from the spleen, lymph node, peripheral blood and peritoneal exudate of mice treated with C. parvum were tested for their ability to inhibit tumour growth in vitro. The peritoneal exudate cells from C. parvum treated mice were extremely effective in inhibiting tumour growth whereas the spleen and peripheral blood cells were only moderately so. In contrast, the lymph node cells caused only a modest inhibition of tumour growth at a very high effector to target cell ratio. Spleen cells from normal mice also exerted a moderate anti-tumour effect

Effect of C. Parvum on immunization with irradiated tumour cells.

S.c. injection of tumour cells or small pieces of tumour irradiated to a dose of 22,000 rad evoked resistance to live challenge with the same tumour (a CBA strain fibrosarcoma induced with methylcholanthrene) 14 days later. This resistance was, however, over-ridden if the challenging inoculum was sufficiently large, and did not develop if the cells were irradiated to 100,000 rad. The resistance evoked by injection of 10(6) irradiated tumour cells was impaired by i.p. injection of 1-4 mg C. parvum 5 days before, and virtually abolished by a similar injection 11 days after, the irradiated cells. The effect of s.c. injection of a mixture of 10(6) irradiated cells and C. parvum 14 days before live challenge depended on the dose of C. parvum. With 0-7 mg the development of resistance was largely but not completely abrogated; 0-35 mg resulted in a lesser degree of abrogation, and 0-09 mg or 0-02 mg had little or no effect

Sensitivity and Specificity of Cystatin C in Detecting Early Renal Impairment in Hypertensive Pregnancies

Purpose: To determine the cutoff point of cystatin C for the detection of renal impairment in hypertensive pregnancies.Methods: A cross-sectional study was conducted in an antenatal clinic and ward at Hospital Universiti Sains Malaysia, Kelantan, Malaysia from January 2009 until January 2010. Sixty four pregnant patients beginning at 2nd trimester, aged of 16 to 55 years and hypertensive, including gestational hypertension, chronic hypertension with superimposed preeclampsia, preeclampsia and unclassified hypertension, were included in the study. Consenting patients were required to provide 5 ml of blood and 24-h urine. Serum and reagent, N Latex cystatin C, were equilibrated at room temperature and measured by particle-enhanced nephelometric immunoassay (PENIA) using a BN II Dade Behring Nephelometer SystemResults: The mean age of the patients was 37.06 ±4.32 (range: 24 to 46 years). A majority (64.1 %) of the patients were in the second trimester of pregnancy and delivered in the gestational period of 38 - 40 weeks (54.7 %). The number of patients in chronic kidney disease (CKD) stages I, II, III, IV and V were 25 (39.1 %), 18 (28.1 %), 18 (28.1 %), 2 (3.1 %) and 1 (1.6 %), respectively. The mean systolic blood pressure was 149.59 ± 18.79 mm Hg, and diastolic blood pressure 91.53 ± 10.33 mm Hg. The cutoff point in detecting renal impairment using cystatin C was > 0.74 with 84.6 % sensitivity and 86.7 % specificity for second trimester and > 0.81 with sensitivity of 76.9 % and specificity of 60.0 % in detecting renal impairment for third trimester.Conclusion: The cutoff point in detecting renal impairment for second trimester is better than for third trimester since it maximizes the value of sensitivity and specificity.Keywords: Cystatin C, Sensitivity, Specificity, Renal impairment, Hypertension; Pregnanc

An Investigation of the dynamic characteristics of an earth dam

An investigation has been made to analyze observations of the effect of two earthquakes (with M L= 6. 3 and 4. 7) on Santa Felicia Dam, a rolled-fill embankment located in Southern California. The dam is 236.5 ft. high and 1,275 ft. long by 30 ft. wide at the crest. The purpose of the investigation is: (1) to study the nonlinear behavior of the dam during the two earthquakes, (2) to provide data on the in-plane dynamic shear moduli and damping factors for the materials of the dam during real earthquake conditions, and (3) to compare these properties with those previously available from laboratory investigations. From the recorded motions of the dam, amplification spectra were computed to indicate the natural frequencies of the dam and to estimate the relative contribution of different modes of vibrations. A comparison between these natural frequencies and those obtained by two elastic shear -beam models was made to obtain representative dam material properties. In addition, field wave-velocity measurements were carried out as a further check as well as to study the variation of shear wave velocity at various depths in the dam. The amplification spectra showed a predominant frequency of 1.45 Hz in the upstream/ downstream direction; in this direction the response was treated as that of a single-degree-of -freedom hysteretic structure. Three types of digital bandpass filtering of the crest and abutment records were used to enhance the hysteresis loops which show the relationship between the relative displacement of the crest with respect to the abutment and the absolute acceleration of the dam. A method is described which, using some of the existing elastic -response theories, enables the shear stresses and strains, and consequently the shear moduli, to be evaluated from the hysteresis loops. The equivalent viscous damping factors were calculated from the areas inside the hysteresis loops. The shear moduli and the damping factors were determined as functions of the induced strains in the dam. Finally, the shear moduli and damping factors obtained for the dam were compared with previously available laboratory data for sands and saturated clays

A Frequency Reconfigurable Compact Planar Inverted-F Antenna for Portable Devices

In this paper, a low-profile, compact size, inexpensive, and easily integrable frequency reconfigurable antenna system is proposed. The proposed antenna consists of an inverted-F shape antenna, capacitors, and switching PIN diodes. The designed antenna element is fabricated on easy available and less expensive FR-4 substrate (epsilon(r) = 4.4, tan delta = 0.02). The switching diodes are incorporated within the radiating structure of the antenna design, and by changing the different states of PIN diodes, frequency reconfigurable response is achieved. While adjusting the different states of the diodes, the antenna resonates between 0.841 GHz and 2.12 GHz and covers six different frequency bands. The proposed system has compact size of 44x14x3.2 mm(3). The gain of the antenna is between 1.89 and 2.12 dBi. The measurement results shows the good agreement with simulated results for different key performance parameters. Additionally, the proposed antenna shows omni-directional far-field characteristics for various different frequencies

Metamaterial based design of compact UWB/MIMO monopoles antenna with characteristic mode analysis

In this article, a novel metamaterial inspired UWB/multiple-input-multiple-output (MIMO) antenna is presented. The proposed antenna consists of a circular metallic part which formed the patch and a partial ground plane. Metamaterial structure is loaded at the top side of the patches for bandwidth improvement and mutual coupling reduction. The proposed antenna provides UWB mode of operation from 2.6-12 GHz. The characteristic mode theory is applied to examine each physical mode of the antenna aperture and access its many physical parameters without exciting the antenna. Mode 2 was the dominant mode among the three modes used. Considering the almost inevitable presence of mutual coupling effects within compact multiport antennas, we developed an additional decoupling technique in the form of perturbed stubs, which leads to a mutual coupling reduction of less than 20 dB. Finally, different performance parameters of the system, such as envelope correlation coefficient (ECC), channel capacity loss (CCL), diversity gain, total active reflection coefficient (TARC), mean effective gain (MEG), surface current, and radiation pattern, are presented. A prototype antenna is fabricated and measured for validation

Full-scale experimental investigation of a modern earth dam

An extensive investigation has been made based on the results of full-scale dynamic tests performed on a modern earth dam, Santa Felicia Cam in Southern California. This dam was chosen for the experimental studies because it had been subjected to strong shaking during two earthquakes: the strong, 6.3 local Richter magnitude San Fernando earthquake of 1971, and a 1976 earthquake of magnitude 4.7. The records recovered from these two earthquakes provided usable information on the dynamic characteristics of the dam which was instrumented with motion sensors to yield data on the structural response as well as the input ground motion at the site. In the test programs, various types of dynamic excitations were used including mechanical vibration, ambient vibration, hydrodynamically generated forces, and the two strong seismic ground motions; thus, the imposed dynamic forces varied greatly in their time-history characteristics, spatial distributions, and intensities. For the forced vibration tests, the dam was excited into resonance in the upstream-downstream direction and in the longitudinal direction by a coupled pair of mechanical vibration generators (200 feet apart) capable of producing force up to 10,000 lbs. Symmetric and antisymmetric vibrations were separated by synchronizing the two shakers to run in-phase and 1800 out-of-phase, respectively, with the aid of control units. During the ambient vibration tests, the naturally occurring vibrations of the dam caused by strong wind and the spilling of the reservoir were measured. The test of dam response to hydrodynamic forces involved the use of pressure waves (to impinge upon the upstream face of the dam) originating from a controlled, submerged release of gas under pressure in the reservoir water. During the dynamic tests, three-dimensional measurements of the motions of approximately 25 stations along the crest and seven stations on the downstream slope were recorded and then analyzed in both time and frequency domains. Modes of vibrations and associated natural frequencies as well as damping ratios were determined in the frequency range from 0.0 to 6.0 Hz. The reliability of the existing analytical techniques for earth dams, which are restricted to horizontal shear deformation in the upstreamdownstream direction, was examined. Finally, in order to reveal any change in the dynamic properties of the dam, the dam's natural frequencies, mode shapes, dynamic shear moduli and damping factors (the latter two as functions of the induced strains) estimated from the measured responses to the two earthquakes were compared with those determined from the full-scale dynamic excitation tests