bluuebunny/crossref_metadata_2025 huggingface dataset:
The Association between Postmenopausal Osteoporosis and Kidney-Vacuity Syndrome in Traditional Chinese Medicine
Authors: Chen Ya-Yin , Hsue Yin-Tzu , Chang Hen-Hong , Gee Mei-Jih
Published: November 2003

The aim of this study was to evaluate the association between postmenopausal osteoporosis and kidney-vacuity syndrome. Eighty-one postmenopausal women were enrolled; their age were between 40 to 65 years old. The mean ages of the non-osteoporosis group and osteoporosis group were 54.0 ± 4.8 and 58.9 ± 5.9 years old, respectively. Bone density examination was perfonned by DEXA technique and the diagnosis of osteoporosis was made by finding 2.5 standard deviations below the bone density of healthy youths. Kidney-vacuity syndrome was deduced according to the diagnostic criteria developed in the National Congress on Chinese Medicine and Sino-Western Combined Geriatric Medicine held in the People's Republic of China in 1986. The results showed that patients with kidney-qi-vacuity and kidney-yin-vacuity were more likely to have osteoporosis than those who were not. No significant difference in the rates of osteoporosis between the kidney-yang-vacuity group and non-kidney-yang-vacuity group was found. The kidney-qi-yin-vacuity group had a higher probability of developing osteoporosis than the kidney-qi-vacuity or kidney-yin-vacuity group. By logistic regression analysis, patients with kidney-qi-vacuity or kidney-yin-vacuity were more likely to develop osteoporosis than those who were not. In conclusion, a marked association between kidney-vacuity syndrome and postmenopausal osteoporosis was observed. Patients with kidney-qi-yin-vacuity syndrome were more likely to get osteoporosis than those with kidney-qi-vacuity syndrome or kidney-yin-vacuity syndrome.
Antiviral Effect of Gingyo-San, a Traditional Chinese Herbal Medicine, on Influenza A2Virus Infection in Mice
Authors: Kobayashi Makiko , Davis Stephen M. , Utsunomiya Tokuichiro , Pollard Richard B. , Suzuki Fujio
Published: November 2003

Gingyo-san is a crude drug containing extracts from 7 medicinal plants and fermented soybeans in a specific ratio. It has been used clinically in China as a therapeutic agent for the common cold. In the present study, we examined the antiviral effect of this agent on influenza virus infection in mice. Gingyo-san and its components were administered orally to mice 1 day before, then 1 and 4, days after the inhalation of a mouse-adopted strain of influenza A2(H2N2) virus. After infection with a 10 LD50of the virus, 100% of mice treated with 10 mg/kg of the agent survived as compared with a 0% survival of control mice treated with saline. Also, the mean survival days were ncreased and consolidation scores were decreased in treated mice as compared with those of control mice. Two components contained in the agent, extracts from Glycyrrhizae radix and Arctii fructus, expressed antiviral activities in mice infected with influenza virus. However, in vitro growth of influenza virus in MDCK cells or viability of the virus was not affected by these extracts or Gingyo-san. From these results Gingyo-san was shown to be an antiviral agent in mice infected with a lethal amount of a mouse-adopted strain of influenza A2virus.
The Evaluation of Antianaphylactic Effect ofOryza sativaL. in Rats
Authors: Kim Hyung Min , Yi Dong-Kue , Shin Hye Young
Published: November 2003

This study was carried out to examine the effect of methanol extract of Oryza sativa L. (Dong-Jin in Korean, abbreviate as Os-DJ hereafter) on anaphylaxis. Os-DJ (10-5to 1 g/kg) dose-dependently inhibited systemic anaphylaxis induced by compound 48/80 in rats. When Os-DJ was pretreated at concentration ranging from 10-5to 1 g/kg, the serum histamine levels were reduced in a dose-dependent manner. Os-DJ (1 g/kg) also significantly inhibited local anaphylaxis activated by anti-dinitrophenyl (DNP) IgE. Moreover, Os-DJ dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. These results indicate that Os-DJ possess anti anaphylactic activity by inhibition of histamine release from mast cells in vivo and in vitro.
Ameliorative Effect of an Urinary Preparation on Acetaminophen and D-galactosamine Induced Hepatotoxicity in Rats
Authors: Lai Tung-Yuan , Wu Yueh-Wern , Lin Wen-Chuan
Published: November 2003

The effect of oral administration of a preparation of human urine (PHU) on acute liver injury was examined in rats intoxicated with acetaminophen and D-galactosamine. The results indicated that PHU protected the liver from acetaminophen and D-galactosamine-induced injury as judged by morphological and biochemical observation. An increase in lipid peroxide concentrations and decrease in protein concentrations occurred in the liver by D-galactosamine injection, PHU administration significantly prevented these changes.
Effect of Panax notoginseng Extracts on Inferior Sperm Motility in vitro
Authors: Chen Jung-Chou , Xu Ming-Xiong , Chen Leih-Der , Chen Yan-Nian , Chiu Tsan Hung
Published: November 2003

The purpose of this study was to investigate the effects of Panax notoginseng extracts on inferior sperm motility in vitro. Semen samples were collected from 23 patients with sperm motility between 20% and 40%. The sperm count was over 20 × 106/ml in accordance with the World Health Organization standard. 1.0 mg/ml and 2.0 mg/ml of Panax notoginseng extracts including aqueous extract, n-butanol extract, and polysaccharide fraction on sperm motility and progression were evaluated by computer assisted semen analysis. The results demonstrated that sperm motility as well as progression on inferior sperm motility were enhanced at 1 hour and 2 hours after incubation with all three types of extracts.
Effects of Acupuncture and An Agonist of Opiate Receptors on Heroin Dependent Patients
Authors: Timofeev M. F.
Published: November 2003

This study examined the influence of acupuncture and an agonist of opiate receptors (Procedol) by means of temperature in both the left and right auricular "Lung" points, and on the coefficIent of interhemisphere asymmetry. Twenty heroin dependent patients participated in this research. They were evenly divided into two groups. Both groups consisted of 10 male drug addicts (18-19 years old) who had been using heroin for 8-10 months. Group 1 received 1.0 ml procedol (i. m.). Group 2 were treated with acupuncture. Temperature was measured on the acupuncture points before and after treatment. Results of this study showed that temperature increased on the left and decreased on the right acupuncture points in both the procedol and acupuncture treated groups. The net changes before and after treatment were 92.87% and 92.53% in groups 1 and 2 respectively. The therapeutic effect of acupuncture on treatment of heroin dependence is through the same pathway as the agonist on opiate receptors, 20% of patients are resisted to acupuncture.
Effect of a Urinary Preparation on Liver Injury by Short-term Carbon Tetrachloride Treatment in Rats
Authors: Lai Tung-Yuan , Wu Yueh-Wern , Lin Wen-Chuan
Published: November 2003

The hepatoprotective effect of a preparation of human urine (PHU) was assessed against short-term carbon tetrachloride (CCl4) treatment in rats. Significant prevention of liver injury by PHU was found after CCl4treatment, judging by the changes of serum biochemical parameters, and hepatic protein and triglyceride contents. The increased liver lipid peroxidation, and decreased liver vitamin C concentrations observed after CCl4treatment were significantly prevented by PHU administration. The increase in liver glutathione (GSH) contents observed after CCl4treatment was further increased by PHU treatment. Liver catalase activity decreased after CCl4treatment, while liver superoxide dismutase and GSH-peroxidase activities did not change. PHU administration further inhibited the decrease in liver catalase activity after CCl4treatment. These results indicate that PHU administration can prevent liver injury induced by CCl4in rats by inhibiting enhanced lipid peroxidation and by improving disrupted active oxygen metabolism in the injured liver.
Miscarriage Prevention Tea Affects Plasma β-Endorphin Concentrations in Women with Early Threatened Abortions
Authors: Sun Fei , Yan Dun Qing , Zhang Gong Li , Yu Jin , Xiao En Nian
Published: November 2003

Twenty threatened abortive patients in the 7-8th week of gestation were treated with a classical miscarriage prevention tea (Shou-Tai-Tang) combined with psychological consultation. All of the patients had a history of unexplained recurrent abortions. This treatment succeeded in sixteen out of 20 patients. The plasma concentrations of ß-endorphin (ß-EP), gonadotrophin releasing hormone (GnRH), human chorionic gonadotrophin (hCG), and progesterone (P4) were measured by radioimmunoassay before and after treatment. Comparied to control subjects, ß-EP levels were significantly higher, while GnRH, hCG, and P4 were lower than before treatment. Concentrations of these peptides/hormones returned to normal ranges after successful treatment.
Effect of Koso-san on Globus Pharyngeus
Authors: Motoo Yoshiharu , Taga Hirorni , Su Shi-Bing , Sawabu Norio
Published: November 2003

Twenty-three patients with globus pharyngeus were treated with Koso-san (TJ- 70) at a dose of 7.5 g/day for at least 14 days. Symptoms disappeared in 18 cases and improved in 3 cases, therefore, the effective rate was 91.3% (21/23). The symptoms disappeared on average within 13.5 days. Terasawa qi-stasis scores were significantly decreased after the treatment. TJ-70 might thus be a remedy for globus pharyngeus with qi-stasis.
Effects of Acupuncture on Exercise-Induced Muscle Soreness and Serum Creatine Kinase Activity
Authors: Lin Jaung-Geng , Yang Shao-Hui
Published: November 2003

The purpose of this study was to determine the effects of acupuncture on delayed onset muscle soreness (DOMS) produced by exercise. Baseline data were collected on 20 male subjects for intensity of muscle soreness and serum creatine kinase (CK) activity. All values were subsequently reassessed 24, 48 and 72 hours after exercise. The experimental group received acupuncture treatment while the control group received no treatment. Muscle soreness perception was significantly less (P < 0.05) at 72 hours in the acupuncture treated group compared to control group. However, the change in CK was not significantly different between groups. These results suggest that acupuncture is effective in decreasing muscle soreness but does not prevent CK release from muscle.
Shini-San Inhibits Mast Cell-Dependent Immediate-Type Allergic Reactions
Authors: Kim H. M. , Lee Y. H. , Chae H. J. , Kim H. R. , Baek S. H. , Lim K. S. , Hwang C. Y.
Published: November 2003

Shini-San has been used for treatment of allergic disease in Korea. However, its effect in experimental models remains unknown. The mast cell plays a pivotal role in initiating allergic response by secreting intracytoplasmic granular mediators such as histamine. The present report describes an inhibitory effect of Shini-San on mast cell-mediated immediate-type allergic reactions. Topical application of compound 48/80 can induce an ear swelling response in normal (WBB6F1-+/+) mice but not in congenic mast cell-deficient WBB6F1-W/Wvmice. Shini-San inhibited concentration-dependent mast cell-dependent ear swelling response induced by compound 48/80 in normal mice. Shini-San inhibited concentration-dependent passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) immunoglobulin E (IgE) in rats by topical application. Shini-San also inhibited in concentration-dependent fashion the histamine release from the rat peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, Shini-San had a significant inhibitory effect on compound 48/80-induced systemic anaphylactic reaction. These results indicate that Shini-San inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.
Effects of Lu-Duo-Wei Capsule on Prolonging Life Span of Housefly and Drosophila Melanogaster
Authors: Cui Xu , Dai Xiang-Guo , Li Wen-Bin , Zhang Bing-Lie , Fang Yun-Zhong
Published: November 2003

Lu-Duo-Wei capsule is a product of Chinese medicine having high efficacy in scavenging superoxide and hydroxyl radicals. It contains antioxidants, which may increase longevity, but whether Lu-Duo-Wei capsule has such an effect is unknown. In this study, supplementing the basic diet with Lu-Duo-Wei resulted in prolonging the life span of houseflies and fruit flies. Moreover, the effect of prolonging the life span of houseflies by Lu-Duo- Wei was significantly higher than that of tea polyphenol. The result not only confirms our previous report but also supports the free radical theory of aging.
DIRAC ANALYSIS AND INTEGRABILITY OF GEODESIC EQUATIONS FOR CYLINDRICALLY SYMMETRIC SPACETIMES
Authors: CAMCI UGUR
Published: November 2003

Dirac's constraint analysis and the symplectic structure of geodesic equations are obtained for the general cylindrically symmetric stationary spacetime. For this metric, using the obtained first order Lagrangian, the geodesic equations of motion are integrated, and found some solutions for Lewis, Levi-Civita, and Van Stockum spacetimes.
SOME PREDICTIONS OF THE COSMOLOGICAL SCHRÖDINGER EQUATION
Authors: FEOLI ANTONIO
Published: November 2003

Starting from the apparently periodic structures of the universe, revealed in a series of recent observations, we suppose that Dark Matter is composed of a quantum particle of very low mass and is clustered around the luminous matter of galaxies. We reduce the cosmological Friedman–Einstein dynamical system to a sort of Schrödinger equation for this quantum particle with a simple first quantization scheme. Comparing the eigen-solutions of this Cosmological Schrödinger Equation with the experimental periodic large scale structure, we predict the possible value of the mass of the dark quantum particle in two remarkable cases.
FLAT COSMOLOGICAL MODELS WITH MASSIVE SCALAR FIELD IN GAUGE THEORIES OF GRAVITY
Authors: VERESHCHAGIN G. V.
Published: November 2003

Solutions of gravitational equations of gauge theories of gravity in homogeneous isotropic world with massive scalar field are investigated in the case of flat cosmological models. Special attention is dedicated to behavior of solutions on contraction stage. It is shown, that on expansion stage inflationary solutions are generic feature of the model. At the same time on contraction stage an effective equation of state can be similar to the case of massless scalar field p=ρ at the beginning of evolution and tends to the equation of ultrarelativistic gas p=ρ/3. The Hubble parameter tends to some negative value on contraction stage, depending on the mass of the scalar field. Nonsingular solutions in this model are unstable.
COSMOLOGICAL ISSUES FOR REVISED CANONICAL QUANTUM GRAVITY
Authors: MONTANI GIOVANNI
Published: November 2003

In a recent work1 we presented a reformulation of the canonical quantum gravity, based on adding the so-called kinematical term to the gravity-matter action. This revised approach leads to a self-consistent canonical quantization of the 3-geometries, which referred to the external time as provided via the added term.

Here, we show how the kinematical term can be interpreted in terms of a non-relativistic dust fluid which plies the role of a "real clock" for the quantum gravity theory, and, in the WKB limit of a cosmological problem, makes account for a dark matter component which, at present time, could play a dynamical role.
SYNTHESIS OF 2D QUASI-ALIGNED MULTIWALLED CARBON NANOTUBES BY CATALYTIC CHEMICAL VAPOR DEPOSITION METHOD
Authors: MUKHOPADHYAY KINGSUK , MATHUR GYANESH NARAYAN
Published: November 2003

Alignment or patterning of carbon nanotubes (CNTs) is particularly important for fabricating functional devices such as field emitters, nanophotonics, nanoelectronics, and ultrahydrophobic materials. This work reports on the synthesis of 2D quasi-aligned carbon nanotube bundles by catalytic chemical vapor deposition (CCVD) method using a series of catalysts and a study of their performance in a nutshell.
A COMPOSITE FROM SOY OIL AND CARBON NANOTUBES
Authors: IN HET PANHUIS MARC , THIELEMANS WIM , MINETT ANDREW I. , LEAHY RORY , LE FOULGOC BAPTISTE , BLAU WERNER J. , WOOL RICHARD P.
Published: November 2003

Carbon nanotubes (CNTs) were stabilized in solution through sonication-induced polymerization of acrylated epoxidized soybean oil (AESO) monomer. Transmission electron microscopy and atomic force microscopy showed that the resulting polymer coatings of nanotubes in solution were approximately 10–30 nm in thickness. Raman spectroscopy suggests that AESO intercalates Nanocyl bundles and coats the exterior of HiPco bundles. Using sonication a stable dispersion of as-produced carbon nanotube powder was formed. Mechanical measurements on macroscale composites samples showed modulus enhancement consistent with a lower bound rule of mixtures.
Phase 1 study of low-dose prolonged exposure schedules of the hypomethylating agent 5-aza-2′-deoxycytidine (decitabine) in hematopoietic malignancies
Authors: Issa Jean-Pierre J. , Garcia-Manero Guillermo , Giles Francis J. , Mannari Rajan , Thomas Deborah , Faderl Stefan , Bayar Emel , Lyons John , Rosenfeld Craig S. , Cortes Jorge , Kantarjian Hagop M.
Published: November 2003

Decitabine (5-aza-2′-deoxycytidine) inhibits DNA methylation and has dual effects on neoplastic cells, including the reactivation of silenced genes and differentiation at low doses and cytotoxicity at high doses. We evaluated, in a phase 1 study, low-dose prolonged exposure schedules of decitabine in relapsed/refractory leukemias. Patient cohorts received decitabine at 5, 10, 15, or 20 mg/m2 intravenously over one hour daily, 5 days a week for 2 consecutive weeks, doses 5- to approximately 30-fold lower than the maximum tolerated dose (MTD). There were 2 groups that also received 15 mg/m2 daily for 15 or 20 days. A total of 50 patients were treated (44 with acute myelogenous leukemia [AML]/myelodysplasia [MDS], 5 with chronic myelogenous leukemia [CML], and 1 with acute lymphocytic leukemia [ALL]), and the drug was well tolerated at all dose levels, with myelosuppression being the major side effect. Responses were seen at all dose levels. However, the dose of 15 mg/m2 for 10 days appeared to induce the most responses (11 of 17 or 65%), with fewer responses seen when the dose was escalated or prolonged (2 of 19 or 11%). There was no correlation between P15 methylation at baseline or after therapy and response to decitabine. We conclude that decitabine is effective in myeloid malignancies, and low doses are as or more effective than higher doses.
Mechanisms of homing in the fiddler crabUca rapax1. Spatial and temporal characteristics of a system of small-scale navigation
Authors: Layne John E. , Barnes W. Jon P. , Duncan Lindsey M. J.
Published: November 2003

Fiddler crabs Uca rapax are central-place foragers, making feeding excursions of up to 2 m from their burrows. We describe the natural feeding excursions of path-integrating fiddler crabs and analyze their paths for signs of significant systematic or random navigation errors. No signs of any systematic errors are evident. Random errors are small, probably due to a combination of the short length and low sinuosity of the foraging paths, as well as the fiddler crabs' unique method of locomotion that allows them to remain oriented to their burrows throughout the foraging path and to minimize large body turns. We further examined the extent to which their body orientation during foraging (transverse body axis pointing more or less towards home) accurately represented their stored home vector. By examining sequences of fast escape, we have shown that crabs can correct for deviations of their transverse body axis from home during their escape path. Thus their stored home vector is independent of their moment-to-moment body orientation.

Crabs were subjected to passive translational displacements and barrier obstructions. Responses to translational displacements were identical to those observed by previous authors, namely that crabs returned in the correct egocentric direction and distance as though no displacement had occurred. Covering the burrow entrance resulted in crabs returning to the correct position of the burrow, and then beginning to search. When a barrier was placed between foraging crabs and their burrow, crabs oriented their bodies toward the burrow as accurately as with no barrier.
Mechanics of wing-assisted incline running (WAIR)
Authors: Bundle Matthew W. , Dial Kenneth P.
Published: November 2003

A recently discovered locomotor behavior, wing-assisted incline running(WAIR), allows fully volant animals to `run' up vertical obstacles. Such a task would appear to be especially formidable for bipeds, yet WAIR is used preferentially by ground-dwelling birds, specifically chukar partridge Alectoris chukar, to reach refugia. The basic locomotor mechanics that enable this behavior are not fully understood. For instance, are there functional differences at the level of the wing during WAIR and free flight,and do the hindlimbs actively participate in propulsion during WAIR? To investigate wing function during these activities we used accelerometry to compare the instantaneous whole-body acceleration during WAIR and ascending free flights at a similar climb angle. Throughout a substantial portion of the wingbeat cycle, chukars engaged in WAIR experienced an acceleration oriented towards the substrate, whereas during ascending free flights the acceleration of the center of mass was parallel to the direction of travel. We investigated whether the animals were using their hindlimbs for propulsion, rather than for some other function (e.g. to maintain balance), by measuring ground reaction forces (GRF) during bouts of WAIR. Estimates of the contribution of the hindlimbs towards the vertical external work done by the bird were 98±8% of the total at an incline of 60° (the steepest angle that birds were able to negotiate without the use of their forelimbs). During vertical (90°) bouts of WAIR the hindlimb contribution was 37±5% of the total external work. Yet, the magnitude of the peak GRF at 90° was 175% of the value generated during level walking, revealing that birds engaged in WAIR do generate sizeable hindlimb forces even during vertical ascents. These data support the hypothesis that forelimbs are enabling hindlimb function, and we argue that this represents a locomotor strategy which may have been used by proto-birds during the evolution of flight.
Repeatability of standard metabolic rate and gas exchange characteristics in a highly variable cockroach,Perisphaeriasp.
Authors: Marais Elrike , Chown Steven L.
Published: November 2003

For natural selection to take place several conditions must be met,including consistent variation among individuals. Although this assumption is increasingly being explored in vertebrates, it has rarely been investigated for insect physiological traits, although variation in these traits is usually assumed to be adaptive. We investigated repeatability (r) of metabolic rate and gas exchange characteristics in a highly variable Perisphaeriacockroach species. Although this species shows four distinct gas exchange patterns at rest, metabolic rate (r=0.51) and the bulk of the gas exchange characteristics (r=0.08–0.91, median=0.42) showed high and significant repeatabilities. Repeatabilities were generally lower in those cases where the effects of body size were removed prior to estimation of r. However, we argue that because selection is likely to act on the trait of an animal of a given size, rather than on the residual variation of that trait once size has been accounted for, size correction is inappropriate. Our results provide support for consistency of variation among individuals, which is one of the prerequisites of natural selection that is infrequently tested in insects.
Na+/K+-ATPase α-isoform switching in gills of rainbow trout (Oncorhynchus mykiss) during salinity transfer
Authors: Richards Jeff G. , Semple Jeffrey W. , Bystriansky Jason S. , Schulte Patricia M.
Published: November 2003

We identified five Na+/K+-ATPase α-isoforms in rainbow trout and characterized their expression pattern in gills following seawater transfer. Three of these isoforms were closely related to other vertebrate α1 isoforms (designated α1a, α1b and α1c),one isoform was closely related to α2 isoforms (designated α2) and the fifth was closely related to α3 isoforms (designated α3). Na+/K+-ATPase α1c- and α3-isoforms were present in all tissues examined, while all others had tissue specific distributions. Four Na+/K+-ATPase α-isoforms were expressed in trout gills (α1a, α1b, α1c and α3). Na+/K+-ATPase α1c- and α3-isoforms were expressed at low levels in freshwater trout gills and their expression pattern did not change following transfer to 40% or 80% seawater. Na+/K+-ATPase α1a and α1b were differentially expressed following seawater transfer. Transfer from freshwater to 40% and 80% seawater decreased gill Na+/K+-ATPaseα1a mRNA, while transfer from freshwater to 80% seawater caused a transient increase in Na+/K+-ATPase α1b mRNA. These changes in isoform distribution were accompanied by an increase in gill Na+/K+-ATPase enzyme activity by 10 days after transfer to 80% seawater, though no significant change occurred following transfer to 40% seawater. Isoform switching in trout gills following salinity transfer suggests that the Na+/K+-ATPase α1a- andα1b-isoforms play different roles in freshwater and seawater acclimation, and that assays of Na+/K+-ATPase enzyme activity may not provide a complete picture of the role of this protein in seawater transfer.
Loss of gustatory responses to pyrrolizidine alkaloids after their extensive ingestion in the polyphagous caterpillar Estigmene acrea
Authors: Bernays E. A. , Rodrigues D. , Chapman R. F. , Singer M. S. , Hartmann T.
Published: November 2003

Electrophysiological recordings from taste sensilla of the caterpillar Estigmene acrea with the pyrrolizidine alkaloid (PA) seneciphylline N-oxide demonstrated that extensive feeding on plants rich in PAs caused a loss in response of the PA-sensitive cell in the lateral styloconic sensillum on the galea. The effect could be repeated using pure PAs fed to the insect in synthetic diets and by injection of PA into the hemolymph. The sensitivity loss lasted for approximately two hours and was less pronounced in individuals that had been reared on PA-containing food. Behavioral experiments and field observations demonstrate a parallel reduction in responsiveness to PAs and to PA-containing plants.
Influences of thermal acclimation and acute temperature change on the motility of epithelial wound-healing cells (keratocytes) of tropical,temperate and Antarctic fish
Authors: Ream Rachael A. , Theriot Julie A. , Somero George N.
Published: November 2003

The ability to heal superficial wounds is an important element in an organism's repertoire of adaptive responses to environmental stress. In fish,motile cells termed keratocytes are thought to play important roles in the wound-healing process. Keratocyte motility, like other physiological rate processes, is likely to be dependent on temperature and to show adaptive variation among differently thermally adapted species. We have quantified the effects of acute temperature change and thermal acclimation on actin-based keratocyte movement in primary cultures of keratocytes from four species of teleost fish adapted to widely different thermal conditions: two eurythermal species, the longjaw mudsucker Gillichthys mirabilis (environmental temperature range of approximately 10-37°C) and a desert pupfish, Cyprinodon salinus (10-40°C), and two species from stable thermal environments, an Antarctic notothenioid, Trematomus bernacchii(-1.86°C), and a tropical clownfish, Amphiprion percula(26-30°C). For all species, keratocyte speed increased with increasing temperature. G. mirabilis and C. salinus keratocytes reached maximal speeds at 25°C and 35°C, respectively, temperatures within the species' normal thermal ranges. Keratocytes of the stenothermal species continued to increase in speed as temperature increased above the species'normal temperature ranges. The thermal limits of keratocyte motility appear to exceed those of whole-organism thermal tolerance, notably in the case of T. bernacchii. Keratocytes of T. bernacchii survived supercooling to -6°C and retained motility at temperatures as high as 20°C. Mean keratocyte speed was conserved at physiological temperatures for the three temperate and tropical species, which suggests that a certain rate of motility is advantageous for wound healing. However, there was no temperature compensation in speed of movement for keratocytes of the Antarctic fish, which have extremely slow rates of movement at physiological temperatures. Keratocytes from all species moved in a persistent,unidirectional manner at low temperatures but at higher temperatures began to take more circular or less-persistent paths. Thermal acclimation affected the persistence and turning magnitude of keratocytes, with warmer acclimations generally yielding more persistent cells that followed straighter paths. However, acclimation did not alter the effect of experimental temperature on cellular speed. These findings suggest that more than one temperature-sensitive mechanism may govern cell motility: the rate-limiting process(es) responsible for speed is distinct from the mechanism(s) underlying directionality and persistence. Keratocytes represent a useful study system for evaluating the effects of temperature at the cellular level and for studying adaptive variation in actin-based cellular movement and capacity for wound healing.
Promoting Relationship Learning
Authors: Selnes Fred , Sallis James
Published: November 2003

The authors develop a theory of how management can develop and promote the learning capabilities of targeted customer–supplier relationships. The theory suggests that a supplier and a customer can improve their joint learning activities by facilitating information exchange, developing common learning arenas, and updating their behavior accordingly. The authors suggest that learning within a customer–supplier relationship cannot be mandated by either organization, but rather learning depends on both parties’ willingness to cooperate in joint learning activities. Management can promote relationship learning by cultivating a collaborative culture, formulating specific objectives for joint learning activities, and developing relational trust. However, as relational trust develops, the effectiveness of learning is reduced as a result of “hidden costs” of trust. The authors use data from 315 dyads to test the theory empirically, and they find that the learning capability of a relationship has a strong, positive effect on performance. Their results also provide insight into how to address the hidden costs of trust.
Carrierless Amplitude–Phase Modulation
Authors: Saltzberg Burton R.
Published: November 2003

Carrierless Amplitude‐Phase Modulation (CAP) is a two‐dimensional digital modulation system very similar to Quadrature Amplitude Modulation (QAM). As in QAM, the modulated signal consists of two passband signals occupying the same spectrum. Instead of using explicit modulation by a pair of quadrature carriers as in QAM, CAP achieves orthogonality by passing the data signals through a pair of band‐pass filters which constitute a Hilbert pair. CAP has found application particularly in Digital Subscriber Line systems.
High‐Rate Punctured Convolutional Codes
Authors: Haccoun David
Published: November 2003

This chapter presents high‐rate punctured convolutional codes. Perforation matrices, weight spectra and upper bounds on the bit error probability of the best known punctured codes having memory 2 ≤ M ≤ 8, and coding rates 2/3 ≤ R ≤ 7/8 are provided. Rate‐2/3 and 3/4 long‐memory punctured convolutional codes with 9 ≤ M ≤ 23 are provided together with the leading terms of their weight spectra and their bit error performance bounds.
Trends in Wireless Indoor Networks
Authors: Pahlavan K. , Beneat J. , Li X.
Published: November 2003

This chapter provides an overview of the trends in wireless indoor networks. Since the late 1970's when the concept of wireless LAN was first introduced, this area has gone through significant ups and downs. After a very exciting development period in the late 1980's, market revenues still remained far below predictions in the mid 1990's. However, during the late 1990's with the introduction of wireless personal area networking, Bluetooth technology, and home networking, a new surge of excitement has emerged in the wireless indoor communication industry, resulting in a number of new start up projects. Furthermore in the past few years, the emergence of wireless indoor positioning systems to augment wireless indoor telecommunication services, has attracted tremendous attention to wireless indoor networks.
Frequency‐Division Multiple Access (
FDMA
): Overview and Performance Evaluation
Authors: Pavlidou Fotini‐Niovi
Published: November 2003

A general presentation of the Frequency Division Multiple Access Technique (FDMA) is tried. The main operation principles and the applications environment are presented first. The performance of the system is illustrated in terms of throughput and ‐noise ratio factors. The different kinds of noise affecting the system performance are described. Then, the quite numerous implementation alternatives are examined and the difference in the used terminology is investigated. A comparison with other Access Techniques is given finally with a reference list for further investigation.
Trellis Coding
Authors: Schlegel Christian
Published: November 2003

The tremendous growth of high‐speed logic circuits and very large‐scale integration (VLSI) has ushered in the digital information age, where information is stored, processed, and moved in digital format. in this article we discuss error control coding, which is accomplished by introducing dependencies among a large number of digital symbols. Trellis coding is a specific, widespread error control methodology.
Channel Modeling and Estimation
Authors: Tong Lang
Published: November 2003

The design of high performance communication systems often requires channel state information. For many applications, especially in wireless communications, such information must be obtained adaptively. In this article, a parametric model of the transmission of linearly modulated signals over a band‐limited channel is presented. Also included is an overview of various parameter estimation techniques and performance bounds of estimators under different model assumptions.
Antennas
Authors: Balanis Constantine A. , Polycarpou Anastasis C.
Published: November 2003

This chapter is a summary on the theory of antennas, and it has been written as an introduction for the technologist and as a review for the antenna expert. The paper traces the history of antennas and some of the most basic radiating elements, demonstrates the fundamental principles of antenna radiation, reviews Maxwell's equations, and outlines basic procedures and equations of radiation. Modeling of antenna sources excitation is illustrated, and antenna parameters and figures‐of‐merit are introduced. The basics of arrays, as well as those of adaptive arrays and smart antennas, are discussed.
Wireless Location
Authors: Sayed Ali H. , Yousef Nabil R.
Published: November 2003

This article provides an overview of wireless location technologies, methods and applications.
Cryptography
Authors: Blake Ian F.
Published: November 2003

This article gives an overview of current cryptographic theory and practice. The notions of symmetric and asymmetric, or public key, cryptography are introduced. It is shown how public key systems depend on notions from computational number theory for their properties. The fundamental ideas of key exchange and digital signatures are discussed. Other protocols such as authentication and identification are also noted.
Adaptive Receivers for Spread‐Spectrum Systems
Authors: Mitra Urbashi
Published: November 2003

Adaptive demodulation algorithms for direct‐sequence code‐division multiple‐Access (DSCDMA) signaling are described herein. The article begins with a review of multiple‐access signaling and DSCDMA modulation. Several key static (nonadaptive) multiuser reception schemes are described and some basic elements of adaptive algorithms are presented. Adaptive receivers for additive white Gaussian noise channels and frequency selective fading channels are provided.
Unequal Error Protection Codes
Authors: Aksu Arda
Published: November 2003

The error correcting capability of the Unequal Error Protection (UEP) codes is described in terms of correcting errors in specific digits of a codeword even though other digits may be decoded incorrectly. UEP codes were first studied in [1] by Masnick and Wolf. Since then, there has been a proliferation of studies in the field of UEP codes, both in theory and in practical applications. This article provides a tutorial treatment of UEP codes and describes some applications.
Acoustic Transducers
Authors: Massa Donald P.
Published: November 2003

The purpose of this article is to provide a brief overview of the very extensive topic of acoustic transducers. Transducers are devices that transform one form of energy into another. We present a brief historical overview and then discuss the many factors that affect the design of an electroacoustic transducer. Next, we discuss the various transduction materials and mechanisms needed to transform electrical energy into sound and vice versa. Finally, we present several short descriptions of the construction of a few electroacoustic transducers.
Active Antennas
Authors: Mickelson Alan R.
Published: November 2003

An active antenna is an antenna system in which the antenna is an integral part of the circuit supplying the signal to (driving) the antenna, in transmit mode, and/or the circuit receiving the signal from the antenna is an integral part of the antenna, in the receiving mode. Such an antenna system can exhibit characteristics which are quite distinct from those exhibited by an ideal linear antenna which is electrically isolated from its feed, or read‐out, network. The first section of this article gives an historical perspective on developments in radio technology before giving a qualitative discussion of transmission line modes and antenna modes and how these modes need to relate to one and another in an active configuration. The second section of this article is quantitative and first introduces the Poynting vector in order to analyze impedance matching from an electromagnetic viewpoint before presenting a circuit theoretical discussion of oscillators and their impedance matching requirements. The third section of the article discusses some applications such as active impedance matching, parametric down conversion, power boosting, proximity detection, and active retroflection as well as quasi‐optical power combining (borrowing from array concepts introduced in the second section)
Continuous Phase Frequency Shift Keying (
CPFSK
)
Authors: Schonhoff Thomas A.
Published: November 2003

Continuous Phase Frequency Shift Keying (CPFSK) is a modulation that, as its name implies, can be characterized as a traditional frequency shift keyed (FSK) signal constrained to maintain continuous phase at its symbol time boundaries. This constraint offers important advantages in error rate performance as well as signal spectrum containment. In this paper, the modulation is introduced and its relationship to the more general Continuous Phase Modulation (CPM) is outlined. The spectrum of CPFSK is presented and optimal coherent and noncoherent receiver structures are developed. Finally, the coherent and noncoherent error‐rate performance of CPFSK is presented.
Optical Solitons
Authors: Karlsson Magnus , Andrekson Peter
Published: November 2003

The properties and history of soliton pulse propagation in optical fibers are reviewed. Both fundamental mathematical aspects are discussed as well as applied engineering issues for e.g. the generation and use of solitons in fiber‐optic communication systems. We distinguish between conventional solitons, which have a constant dispersion along the transmission, and dispersion‐managed solitons for which the dispersion varies along the transmission line. Finally the most recent soliton field experiments are reviewed and discussed.
Optical SynchronousCDMASystems
Authors: Ohtsuki Tomoaki , Sasase Iwao
Published: November 2003

Optical CDMA systems have been investigated widely to apply for high speed LAN, because they allow multiple users to access the network simultaneously. For optical CDMA systems, both asynchronous and synchronous systems have been studied. With synchronous CDMA, the available number of signature codes is larger than that of asynchronous CDMA systems. For a given value of bit error rate, synchronous CDMA systems can accommodate more simultaneous users than asynchronous CDMA systems. Furthermore, synchronous CDMA can be efficiently used in conjunction with TDMA and WDMA on multimedia communication networks.

This chapter discusses sequences, modulations, system architectures used in optical synchronous CDMA systems and their performance.
Compensation of Nonlinear Distortion inRFPower Amplifiers
Authors: Chang Sekchin , Powers Edward J.
Published: November 2003

In this article the concept of using predistorters to compensate for distortion associated with the saturation properties of RF power amplifiers (PAs) is described. The nonlinear input‐output characteristics of RF PAs are described, and the sensitivity of multicarrier systems, such as orthogonal frequency division multiplexing (OFDM), to nonlinear PAs is discussed. A brief overview of various predistorters is presented and the ability of a particular Volterra‐based predistorter to reduce bit error rate (BER), total degradation, and output backoff is demonstrated via a simulation experiment using a 16‐QAM‐based OFDM system.
Trellis‐Coded Modulation
Authors: Wilson Stephen G.
Published: November 2003

Trellis‐coded modulation (TCM) is an important practical means of achieving several decibels in link efficiency on Gaussian channels, without bandwidth expansion, and is now a component of numerous wireline and wireless standards. This article surveys the important principles in the design and analysis of such encoders, provides tabulations of best codes, and illustrates with discussion of two standards employing TCM.
Reflector Antennas
Authors: Rappaport Carey
Published: November 2003

Reflector antennas are a primary means of transmitting communications signals from point‐to‐point. This section briefly summarizes the important characteristics and design considerations of reflector antennas, including farfield radiation pattern, antenna gain and beamwidth, single and dual reflectors, offset designs to prevent blockage, aperture phase errors and the effects of optical aberrations, and wide field of view scanning systems.
Characterization of Optical Fibers
Authors: Camilo Gilberto M.
Published: November 2003

Optical fibers are characterized according to their geometric, transmission and mechanical properties. Methods are described for measuring the important optical and structural parameters of optical fibers that affect their transmission capacity and their lifetime in the field.
Path Loss Prediction Models in Cellular Communication Channels
Authors: Bertoni H. L.
Published: November 2003

The characteristics of the radio channel provide a challenge to the communications engineer in designing systems that are spectrally efficient so as to provide high speed services to a large numbers of subscribers. Path loss is the most basic of the channel characteristics since it influences coverage and interference predictions for any system. Because the radio links in modern wireless systems are between low base station antennas and the subscribers over relatively short paths within cities, or even inside buildings, the buildings have a major influence on the received signal. Modern systems operate at frequenciesfin the UHF (300 MHz ‐ 3 GHz) and microwave bands, so that the radio waves have wavelength λ less than a meter. Since the buildings are large compared to wavelength, it is appropriate to think of the radio waves as traveling along rays between the base station and the subscriber. Ray concepts are used in this chapter to make quantitative predictions of the path loss. These predictions are to compare well with measurements, and measurement based prediction models.
Photonic Analog‐to‐Digital Converters
Authors: Shoop Barry L.
Published: November 2003

Photonic A/D converters have received and continue to receive considerable attention as an alternative approach to providing increased resolution and speed in high‐performance applications. Several potential advantages of using photonics technologies come in the form of high‐speed clocking, broadband sampling, reduced mutual interference of signals, and compatibility with existing photonic‐based systems. This chapter provides an introduction, discusses progress made and present research, and provides a glimpse of several promising future architectures and technologies.
HF
Communications
Authors: Bussgang Julian J. , Parl Steen A.
Published: November 2003

This chapter discusses the uses and evolution of HF radio communications. The characteristics of HF radio links are summarized and the different functions and components of an HF radio terminal explained. The state of the art in HF radio modems is outlined, with emphasis on higher data rate modems. Modeling of the channel, simulation, and testing are summarized. The chapter concludes with a projection of future trends.
Synchronization in Digital Communication Systems
Authors: Luise M. , Mengali U. , Morelli M.
Published: November 2003

Reliable data detection in digital communication receivers requires that the incoming waveform be time‐aligned with certain locally generated references, namely the data clock and the sinusoidal waveforms used for demodulation. Accomplishment of this goal is referred to assynchronization(abbreviated: sync) and represents a crucial issue in the design of communication systems. Inaccurate receiver synchronization has generally catastrophic effects on the communication link performance. In addition, synchronization circuits encompass such a large part of the receiver resources that they heavily affect the overall cost.

In the following we present an overview of the main synchronization functions for a large class of digitally modulated signals, including conventional (narrow‐band) modulations, direct‐sequence spread‐spectrum, and multicarrier signals. The different sync functions are split intosignalandnetworksynchronization. The former includes data clock and carrier frequency/phase recovery, and is typically carried out within the physical layer of a communication network. The latter is usually performed on digital data streams at the higher layers of the ISO/OSI stack, and deals with the time‐alignment of data frames within the format of the digital stream. As the advent of VLSI technology tends to render obsolete the analog circuits employed so far, this chapter is especially concerned with the description of digital signal processing (DSP)‐based synchronization functions.