bluuebunny/crossref_metadata_2025 huggingface dataset:
A cross sectional study of the respiratory health of workers handling printing toner dust
Authors: Nakadate T , Yamano Y , Adachi C , Kikuchi Y , Nishiwaki Y , Nohara M , Satoh T , Omae K
Published: March 2006

Background:Although recent case reports have suggested possible respiratory effects of solid toner dust inhalation, this hypothesis has not been verified by epidemiological studies.

Objectives:To conduct a cross sectional study to evaluate the association between the biological indices of lung fibrosis and toner dust exposure in an occupational cohort handling solid toner dust in their work life.

Methods:A total of 600 male toner workers and 212 control subjects were surveyed in terms of their subjective respiratory symptoms, pulmonary functions, and chest radiographic findings. In addition to the exposure history, the current working conditions and personal exposure levels to toner dust were also examined.

Results:Although subjects handling toner for more than 20 years tended to show a higher prevalence of respiratory symptoms and minimal chestxray abnormalities, there was no consistent relation between the exposure to toner dust and the biological responses of the respiratory system.

Conclusion:Deterioration of respiratory health related to toner dust exposure is less likely to occur in current well controlled work environments, especially if the powdered toner is handled carefully. Nonetheless, it is important to collect further epidemiological evidence on the biological effects of toner dust inhalation, preferably using a longitudinal study design.
How consistently distributed are the socioeconomic differences in severe back morbidity by age and gender? A population based study of hospitalisation among Finnish employees
Authors: Kaila-Kangas L , Keskimäki I , Notkola V , Mutanen P , Riihimäki H , Leino-Arjas P
Published: March 2006

Aims:To study the socioeconomic distribution of severe back morbidity by age and gender, and to examine to what extent the differences in back morbidity between socioeconomic groups are particularly related to manual work in different age groups.

Methods:Hospital admissions in 1996 for back disorders of 25–64 year old men (3123 of a total 743 961) and women (3043 of 773 936) from the Finnish Hospital Discharge Register were linked with demographic and socioeconomic data from the 1995 population census. Poisson regression analysis was used to calculate the rate ratios for back related hospitalisation by occupational class and education. The distribution of cases according to occupational status and education was presented in relation to the whole occupationally active workforce by age and gender.

Results:Blue-collar (manual) workers had a higher risk of being hospitalised because of back disorders compared with white-collar employees (non-manual) in all age groups among both genders. Manual work versus non-manual work was associated with a 1.3 to 1.4-fold risk (95% CI 1.0 to 1.8) among women and a 1.3 to 1.6-fold risk (95% CI 1.1 to 2.2) among men. The risk of hospitalisation was further inversely associated with educational level within manual and non-manual work in all other age groups except in those aged 55–64 years. Gender related differences were much smaller compared with the socioeconomic ones.

Conclusions:Socioeconomic differences in back morbidity leading to hospitalisation were consistent by age and gender. The results suggest that not only the physical strenuousness of work, but also other causes of severe back disorders are clustered around a subject’s socioeconomic status, indicated by formal education. This may have implications for prevention and the planning of rehabilitation.
Reported occupational respiratory diseases in Catalonia
Authors: Orriols R , Costa R , Albanell M , Alberti C , Castejon J , Monso E , Panades R , Rubira N , Zock J-P
Published: March 2006

Objectives:A voluntary surveillance system was implemented in Catalonia (Spain) to ascertain the feasibility, incidence, and characteristics of occupational respiratory diseases and compare them with those of the compulsory official system.

Methods:In 2002, in collaboration with the Occupational and Thoracic Societies of Catalonia, occupational and chest physicians and other specialists were invited to report, on a bimonthly basis, newly diagnosed cases of occupational respiratory diseases. Information requested on each case included diagnosis, age, sex, place of residence, occupation, suspected agent, and physician’s opinion on the likelihood that the condition was work related. Compulsory official system data derived from statistics on work related diseases for possible disability benefits declared by insurance companies, which are responsible for declaring these diseases to the Autonomous Government of Catalonia.

Results:Of 142 physicians seeing patients with occupational respiratory diseases approached, 102 (74%) participated. Three hundred and fifty nine cases were reported, of which asthma (48.5%), asbestos related diseases (14.5%), and acute inhalations (12.8%) were the most common. Physicians rated 63% of suspected cases as highly likely, 28% as likely, and 8% as low likelihood. The most frequent suspected agents reported for asthma were isocyanates (15.5%), persulphates (12.1%), and cleaning products (8.6%). Mesothelioma (5.9%) was the most frequent diagnosis among asbestos related diseases. The number of acute inhalations reported was high, with metal industries (26%), cleaning services (22%), and chemical industries (13%) being the most frequently involved. The frequency of occupational respiratory diseases recorded by this voluntary surveillance system was four times higher than that reported by the compulsory official system.

Conclusions:The compulsory scheme for reporting occupational lung diseases is seriously underreporting in Catalonia. A surveillance programme based on voluntary reporting by physicians may provide better understanding of the incidence and characteristics of these diseases. Persulphates and cleaning products, besides isocyanates, were the most reported causes of occupational asthma. Metal industries and cleaning services were the occupations most frequently involved in acute inhalations with a remarkably high incidence in our register.
Biochemical Basis of the "Qi-Invigorating" Action of Schisandra Berry (Wu-Wei-Zi) in Chinese Medicine
Authors: Ko Kam-Ming , Chiu Po-Yee
Published: March 2006

Schisandra berry or Wu-Wei-Zi, meaning the "the fruit of five tastes" in Chinese, is a commonly used herb in traditional Chinese medicine (TCM). Based on the "Five-Element" theory in TCM, while the "five tastes" of Schisandra berry refer to its influence on the five visceral organs in the body, ancient Chinese herbalists specifically trumpeted the berry's beneficial effect on the "Qi" of the five visceral organs. "Qi" is a Chinese term used as a broad description of energy-dependent body functions. Over the past ten years, our laboratory has attempted to define the biochemical properties of Schisandra berry in regard to its purported "Qi-invigorating" properties. We have found, for the first time, an ability of Schisandra berry to fortify mitochondrial antioxidant status, thereby offering the body a generalized protection against noxious challenges both of internal and external origin. Given the indispensable role of the mitochondrion in generating cellular energy, the linking of Schisandra berry to the safeguarding of mitochondrial function provides a biochemical explanation for its "Qi-invigorating" action.
A Clinical Study of Acupuncture and SSP (Silver Spike Point) Electro-therapy for Dry Eye Syndrome
Authors: Tseng Kuo-Lieh , Liu Hsu-Jan , Tso Kam-Yuen , Woung Lin-Chung , Su Yi-Chang , Lin Jaung-Geng
Published: March 2006

The present study was designed as a clinical trial to assess the efficacy of acupuncture and silver spike point (SSP) electro-therapy on dry eye syndrome. A total of 43 dry eye syndrome patients participated in the present study. Subjects were divided into control, acupuncture and SSP electro-therapy groups. The three groups were all given artificial tears treatment. Patients in the treatment groups were given two 20-minute treatments of either acupuncture or SSP. Assessment was carried out using the Basal Schirmer test, tear break-up time (BUT), visual analog scale (VAS) and an overall score of eye condition. After four weeks of treatment, both the acupuncture and SSP treatment groups showed improvements over the control group, in Schirmer tests of the left eye and average tearing of both eyes. After 8 weeks of treatment, both treatment groups showed improvements over the control group both in Schirmer tests and VAS. For the right eye, treatment groups showed significant improvements in Schirmer test and VAS versus the control group averages for both eyes. There was no significant difference in BUT at any time. Comparing scores before and after treatment, the acupuncture and SSP groups showed a significant improvement compared to the control group. The acupuncture group showed a greater 8-week improvement in Schirmer tests scores compared to the SSP group. However, the SSP group patients used fewer applications of artificial tears. Acupuncture and SSP electro-therapy were effective in increasing tear secretion in patients with dry eye syndrome. The SSP electro-therapy not only alleviated dry eye syndrome, but also reduced the number of applications of artificial tears necessary.
Homoharringtonine-Induced Apoptosis of Human Leukemia HL-60 Cells is Associated with Down-Regulation of Telomerase
Authors: Xie Wan-Zhuo , Lin Mao-Fang , Huang He , Cai Zhen
Published: March 2006

Homoharringtonine (HHT), first isolated from the Chinese evergreen Cephalotaxus Harringtonia, has been shown inhibiting activity in leukemia in initial studies in China and in later studies in the US, but the detailed mechanism of action is still unclear. The goal of the experiments shown here is to explore the effect of HHT on the telomerase activity and apoptosis of human leukemia HL-60 cells. The telomerase activity of HL-60 cells was examined by the telomeric repeat amplification protocol (TRAP) — an enzyme-linked immunosorbent assay (ELISA). Apoptosis was analyzed by morphological observation, DNA agarose gel electrophoresis, flow cytometry (FCM), and TdT-mediated dUTP-biotin nick end labeling (TUNEL). After treatment with HHT at 5–500 μg/l for 48 hours, the level of telomerase activity in HL-60 cells decreased in a dose-and time-dependent manner. Simultaneously, HL-60 cells underwent apoptosis. In conclusion, our data suggest that HHT can inhibit the telomerase content of HL-60 cells effectively and induce apoptosis.
Baicalin-Induced Apoptosis is Mediated by Bcl-2-Dependent, but not p53-Dependent, Pathway in Human Leukemia Cell Lines
Authors: Shieh Den-En , Cheng Hua-Yew , Yen Ming-Hong , Chiang Lien-Chai , Lin Chun-Ching
Published: March 2006

Acute lymphoblastic leukemia (ALL), especially T-acute lymphoblastic leukemia (T-ALL), is a common childhood malignant neoplastic disorder. Chemotherapy agents, particularly those that can induce apoptosis, are the major intervening strategy in the treatment of ALL. In this study, we investigated in T-ALL cell line, CCRF-CEM, the in vitro cytotoxic effect and the mechanism of action of baicalin, a compound extracted from Scutellaria baicalensis Georgi and S. rivularis Benth (Labiateae). Results demonstrated that baicalin displayed a remarkable cytotoxic effect in CCRF-CEM, with an IC50value of 10.6 μg/ml. It triggered apoptotic effect by fragmentizing cellular DNA and arrested the cell cycle at G0/ G1phase. Baicalin (37.5 μg/ml)had not effected the expression of p53 and Fas protein. It was shown to decline the expression of Bcl-2 (22.0 pg/ml), which consequently caused the loss (52.7%)of transmembrane potential (ΔΨm) in the mitochondria after 72 hours of treatment. Baicalin (37.5 μg/ml) also elevated the amount of cytosolic cytochrome c (19.2 μg/ml), which finally triggered the activation of caspase-3 (50.1 pmol/min). In conclusion, baicalin was found to induce apoptosis in T-ALL cell lines through multiple pathways. This finding encourages further investigation of baicalin in its role as a potential candidate for chemotherapeutic agents in T-ALL.
Curry Leaf (Murraya koenigii Spreng.) Reduces Blood Cholesterol and Glucose Levels in ob/ob Mice
Authors: Xie Jing-Tian , Chang Wei-Tien , Wang Chong-Zhi , Mehendale Sangeeta R. , Li Jing , Ambihaipahar Ramalingam , Ambihaipahar Umadevi , Fong Harry H. , Yuan Chun-Su
Published: March 2006

We observed that curry leaf (Murraya koenigii) extract possesses the property to decrease blood cholesterol and blood glucose levels in diabetic ob/ob mice. Mice received daily intraperitoneal injections of 80 mg/kg curry leaf extract for 10 consecutive days. The extract significantly decreased blood cholesterol level from 277.6 ± 16.6 mg/d (day 0) to 182.0 ± 15.3 mg/d (day 10, p < 0.01 compared with the change in vehicle group). The extract also significantly decreased blood glucose level from 387.0 ± 15.6 mg/dl (day 0) to 214.0 ± 26.6 mg/dl (day 10, p < 0.01). In addition, body weight was reduced after extract treatment. Our data suggest that curry leaf may be proved to be of clinical importance in improving the management of high cholesterol level and type 2 diabetes.
Effects of Goshajinkigan (Niu-Che-Sen-Qi-Wan) for Resiniferatoxin-Sensitive Afferents on Detrusor Overactivity Induced by Acetic Acid in Conscious Rats
Authors: Zhang Xiaoyang , Ishizuka Osamu , Tanabe Tomoaki , Satoh Tomoya , Nakayama Tsuyoshi , Imamura Tetsuya , Nishizawa Osamu
Published: March 2006

This study was performed to investigate the effects of goshajinkigan, a traditional Chinese herbal mixture, in conscious rats undergoing continuous cystometry. Systemic resiniferatoxin (RTX) pretreatment can block resiniferatoxin-sensitive (C-fiber) nerve-mediated bladder overactivity, such as that induced by intravesical administration of acetic acid. The effects of pretreatment with goshajinkigan and RTX alone or in combination on acetic acid-induced bladder overactivity in conscious rats were also compared. Female SD rats were divided into four groups. Groups 1 and 3 received normal food for 4 weeks, while groups 2 and 4 received goshajinkigan (0.09 g/kg/day) during the same period. Two days after bladder catheterization, groups 3 and 4 received RTX (0.3 mg/kg) injection, while groups 1 and 2 received vehicle alone. Cystometric investigations were performed on all animals 24 hours after RTX or vehicle injection. The effects of intravesical instillation of acetic acid ( pH = 4.0) were compared with those of intravesical saline. Goshajinkigan significantly increased threshold pressure, voiding interval, micturition volume, and bladder capacity. Intravesical instillation of acetic acid induced bladder overactivity in both normal rats and in those pretreated with goshajinkigan. However, the effects of acetic acid on voiding interval and micturition volume were significantly different between rats given normal diet and those pretreated with goshajinkigan. The effect of acetic acid was not different between goshajinkigan- and RTX-pretreated rats. The results of the present study indicated that goshajinkigan increases voiding interval, micturition volume, and bladder capacity, and pretreatment with goshajinkigan partially blocks the bladder overactivity induced by intravesical administration of acetic acid in rats.
Sheng-Mai-San Reduces Adriamycin-Induced Cardiomyopathy in Rats
Authors: You Jyh-Sheng , Huang Hui-Feng , Chang Ying-Ling , Lee Ying-Shiung
Published: March 2006

The traditional Chinese medicine prescription "Sheng-Mai-San (SMS)" has been used for treating patients with coronary heart disease for a long time and was found to have antioxidative effects. Here, we applied adriamycin (doxorubicin, ADR), a highly effective anticancer agent, as an inducer to establish the animal model of dose-related cardiomyopathy due to inhibition of nucleic acid as well as protein synthesis, formation of free radicals, and lipid peroxidation. The objective of this study was to investigate the protective effects of SMS on adriamycin-induced cardiomyopathy. Wistar rats were divided into four groups: CONT (control), ADR, SMS, and ADR + SMS. ADR (cumulative dose, 15 mg/kg) was administered to rats in six equal intraperitoneal injections over a period of 2 weeks and SMS was administered via a feeding tube throughout the mouth once a day for 30 days (cumulative dose, 150 g/kg). At the end of the 5-week post-treatment period, the hearts of the rats were surgically removed for the study of synthesis rates of DNA, RNA and proteins. Besides myocardial antioxidants, lipid peroxidation and morphological ultrastructure were also evaluated. Three weeks after the treatment, cardiomyopathy and congestive heart failure were characterized according to assessment in ascites, congested liver, depressed cardiac function and myocardial cell damage. The results demonstrated that nucleic acid as well as protein synthesis was inhibited, while lipid peroxidation was increased. Myocardial glutathione peroxidase (GSHPx) activity was decreased and electron microscopic examination revealed myocardial lesion indicative of ADR-induced cardiomyopathy. In contrast, administration of SMS before and concurrent with ADR significantly attenuated the myocardial effects. It also lowered mortality as well as the amount of ascites. In addition, indexes in myocardial GSHPx, macromolecular biosynthesis and superoxide dismutase activities were increasing, with a concomitant decrease in lipid peroxidation and preserved myocardial ultrastructure. These results indicated that SMS may be partially protective against ADR-induced cardiomyopathy.
Functional and Molecular Characterization for the Damp-Obstructed Rat Model in Chinese Medicine
Authors: Huang G. Steven , Hong Meng-Yen
Published: March 2006

Functional and molecular characterization was performed on the major organs of damp-obstructed rats by applying expression datasets of microarray experiments and real-time RT-PCR. Gene ontology repertoires, i.e. cellular component, molecular function, and biological process were used to classify differentially expressed genes in the major organs of rats upon treatment of dampness. As to the cellular component, over-expression of genes associated with the plasma membrane was observed in the stomach, spleen, kidney, heart, liver, and lung. Genes associated with translational machinery, endoplasmic recticulum membrane, Golgi apparatus, and nuclear envelope were down-regulated in the stomach. Concerning the molecular function, genes associated with oxidoreductase activity were up-regulated in the stomach, spleen, kidney, lung, and brain. Channel activity, membrane receptor, and electron transporter activity were up-regulated in stomach, kidney, and lung. Regarding the biological process, genes associated with signal transduction were up-regulated in the stomach, while genes associated with biosynthesis and ATP metabolism were down-regulated. In the spleen, melanin biosynthesis was up-regulated while hormone-related activities were down-regulated. In the kidney, genes associated with nucleotide biosynthesis and ATP metabolism were depressed. In the heart and liver, apoptosis was up-regulated while immune response and RAS signal transduction were down-regulated. Interestingly, genes associated with oncogenesis were up-regulated in the stomach and kidney. Functional fingerprints indicated that dampness weakened membrane structures, depressed metabolic activity (especially ATP metabolism), damaged matrix proteins, enhanced signal transduction, and revealed a positive association with oncogenesis. To quantify the functional impact at the molecular level, mRNA levels of key genes were determined by real-time RT-PCR. The results indicated that ATP storage in kidney, spleen, and stomach was depleted in damp-obstructed rats. We propose that oxidative stress, membrane integrity, melanin biosynthesis, ion channel activity, and ATP metabolism might be hallmarks for damp-obstructed rats. Our results also suggested dampness as a pathogenic factor in rats which is possibly associated with enhanced liabilities of cancer.
CLUSTERING STRUCTURES IN THE TIME-OCCURRENCE SERIES OF LIGHTNING
Authors: TELESCA LUCIANO , BERNARDI MARINA , ROVELLI CINZIA
Published: March 2006

Lightning data, measured from April to October 2002 in an area of northern Italy, have been analyzed by using the Allan Factor statistics. The sequence of lightning time-occurrences is characterized by two scaling regions, which reveal intra-cluster (inside an individual thunderstorm) and inter-cluster (among successive thunderstorms) time-clustering properties of lightning data. We investigated intra- and inter-cluster correlations for three classes of lightning: (i) the whole series, (ii) the sequence of only negative flashes and (iii) that of only positive flashes. Furthermore, we performed the analysis of the scaling behavior of the three classes of lightning varying the current intensity threshold.
PLAYER'S POSITIONAL DEPENDENCE OF FRACTAL BEHAVIORS IN A SOCCER GAME
Authors: KIM SANGRAK
Published: March 2006

This paper describes fractal behaviors in a soccer game according to the player's position. It is quite important for us to characterize the fractal motion behaviors of the objects during the game. We obtained two-dimensional coordinates of the objects using standard video processing techniques from a computer soccer game. We calculated values of regularization dimensions of the time series to characterize their fractal behaviors. To see positional dependence, we averaged individual player's values over the same position in the same team. When a team is one-sidedly experiencing a severe attack, its defenders have higher fractal dimensions than those of the opponent's corresponding players. We propose a new measure of relative dominance in attack against the opponent team.
A MULTISCALE WAVELET-INSPIRED SCHEME FOR NONLINEAR DIFFUSION
Authors: PLONKA GERLIND , STEIDL GABRIELE
Published: March 2006

Nonlinear diffusion filtering and wavelet shrinkage are two successfully applied methods for discontinuity preserving denoising of signals and images. Recently, relations between both methods have been established taking into account wavelet shrinkage at one scale. In this paper, we propose a new explicit scheme for nonlinear diffusion which directly incorporates ideas from multiscale Haar wavelet shrinkage. We prove that our scheme permits larger time steps while preserving convergence to the mean signal value. Numerical examples demonstrate the behavior of our scheme for two and three scales.
WAVELET NATURAL BOUNDARY ELEMENT METHOD FOR THE NEUMANN EXTERIOR PROBLEM OF STOKES EQUATIONS
Authors: CHEN WEN-SHENG , YOU XINGE , FANG BIN , TANG YUANYAN , HUANG JIAN
Published: March 2006

Natural boundary element approach is a promising method to solve boundary value problems of partial differential equations. This paper addresses the Neumann exterior problem of Stokes equations using the wavelet natural boundary element method. The Stokes exterior problem is reduced into an equivalent Hadamard-singular Natural Integral Equation (NIE). By virtue of the wavelet-Galerkin algorithm, the simple and accurate computational formulae of stiffness matrix are obtained. The 2J+3 × 2J+3 stiffness matrix is sparse and determined only by its 2J + 3J + 1 entries. It greatly decreases the computational complexity. Also, the condition number of stiffness matrix is [Formula: see text], where N is the discrete node number. This indicates that the proposed algorithm is more stable than that of classical finite element method. The error estimates are established for the wavelet-Galerkin approximate solution. Several numerical examples are given to evaluate the performance of our method with encouraging results.
ADAPTIVE WAVELETS FOR IMAGE COMPRESSION USING UPDATE LIFTING: QUANTIZATION AND ERROR ANALYSIS
Authors: HEIJMANS HENK J. A. M. , PIELLA GEMMA , PESQUET-POPESCU BÉATRICE
Published: March 2006

Classical linear wavelet representations of images have the drawback that they are not optimally suited to represent edge information. To overcome this problem, nonlinear multiresolution decompositions have been designed to take into account the characteristics of the input signal/image. In our previous work20,22,23 we have introduced an adaptive lifting framework, that does not require bookkeeping but has the property that it processes edges and homogeneous image regions in a different fashion. The current paper discusses the effects of quantization in such an adaptive wavelet decomposition. We provide conditions for recovering the original decisions at the synthesis and for relating the reconstruction error to the quantization error. Such an analysis is essential for the application of these adaptive decompositions in image compression.
ON THE USE OF THE COMPLEX WAVELET TRANSFORM FOR SUBJECTS CLASSIFICATION AND CYCLE IDENTIFICATION FROM SEMG ANALYSIS DURING WALKING
Authors: DE STEFANO ANTONIO
Published: March 2006

This work proposes several innovative methods to group subjects and to identify the phases of the gait cycle applying the complex wavelet transform (CWT) to signals describing the electrical activity of muscles (EMG) during walking. The subjects classification is based on the extraction of the activation patterns (timing vs. level of activation) from selected wavelets coefficients. The cycle selection is achieved using preliminary physiological assumptions derived from experience about the muscles behavior during walking to process the wavelet coefficients. Two muscles (lateral Gastrocnemius and Tibialis anterior), three groups of subjects (asymptomatic adults, asymptomatic children and pathological children), and footswitch signals acquired concurrently with the EMG have been used to evaluate the results. The experiments demonstrated the prevalence of the results achieved for Gastrocnemius muscle. For both muscles, the asymptomatic adult group results to be discernible from the other two groups and the average absolute timing error between footswitches and EMG based gait cycle estimations results to be smaller than 100 ms.
IMAGE RETRIEVAL BASED ON REGION SEPARATION AND MULTIRESOLUTION ANALYSIS
Authors: KSANTINI R. , ZIOU D. , DUBEAU F.
Published: March 2006

In this paper, a simple and fast querying method for content-based image retrieval is represented. Using the multispectral gradient, a color image is split into two disjoint parts that are the homogeneous color regions and the edge regions. The homogeneous regions are represented by the traditional color histograms, and the edge regions are represented by the multispectral gradient module mean histograms. In order to measure the similarity degree between two color images both quickly and effectively, we use a one-dimensional pseudo-metric, which makes use of the one-dimensional Daubechies decomposition and compression of the extracted histograms. Our querying method is invariant to the query color image object translations and color intensities. The experimental results are reported on a collection of 10,000 LAB color images.
A FOURIER-RADIAL DESCRIPTOR ALGORITHM FOR INVARIANT FEATURE EXTRACTION
Authors: SASTRY CHALLA S. , PUJARI ARUN K. , DEEKSHATULU B. L.
Published: March 2006

By integrating the Fourier techniques and the edge information obtained using the radial symmetric functions, we propose in this paper an invariant feature extraction algorithm. Unlike the Gabor feature extraction method, the present method does not use direction dependent filters, nor does it use the images in polar form, for rotation invariance. Besides, the present Fourier-Radial invariant feature extraction algorithm, suitable for both the texture and non-texture images, has functional analogy with the Gabor feature extraction method, and hence, is easily implementable. It is mathematically proved, and justified through computations, that the method can generate the invariant and discriminative feature vectors. Our simulation results demonstrate that the method can be used for such applications as content-based image retrieval.
WAVELET-BASED IDENTIFICATION AND CONTROL DESIGN FOR A CLASS OF NONLINEAR SYSTEMS
Authors: KARIMI H. R. , LOHMANN B. , MOSHIRI B. , MARALANI P. JABEHDAR
Published: March 2006

In this paper, we extend the wavelet networks for identification and H∞ control of a class of nonlinear dynamical systems. The technique of feedback linearization, supervisory control and H∞ control are used to design an adaptive control law and also the parameter adaptation laws of the wavelet network are developed using a Lyapunov-based design. By some theorems, it will be proved that even in the presence of modeling errors, named network error, the stability of the overall closed-loop system and convergence of the network parameters and the boundedness of the state errors are guaranteed. The applicability of the proposed method is illustrated on a nonlinear plant by computer simulation.
Developmental Regulation of Whole Cell Capacitance and Membrane Current in Identified Interneurons inC. elegans
Authors: Faumont Serge , Boulin Thomas , Hobert Oliver , Lockery Shawn R.
Published: March 2006

Postembryonic developmental changes in electrophysiological properties of the AIY interneuron class were investigated using whole cell voltage clamp. AIY interneurons displayed an increase in cell capacitance during larval development, whereas steady-state current amplitude did not increase. The time course of the outward membrane current, carried at least in part by K+ions, matured, from a slowly activating, sustained current to a rapidly activating, decaying current. We also investigated how the development of capacitance and outward current was altered by loss-of-function mutations in genes expressed in AIY. One such gene, the LIM homeobox gene ttx-3, is known to be involved in the specification of the AIY neuronal subtype. In ttx-3 mutants, capacitance and outward current matured precociously. In mutants of the gene wrk-1, an immunoglobulin superfamily (IgSF) member whose expression is regulated by ttx-3, capacitance matured normally, whereas outward current matured precociously. We conclude that AIY interneurons contain distinct pathways for regulating capacitance and membrane current.
The Interplay Between Homeostatic Synaptic Plasticity and Functional Dendritic Compartments
Authors: Rabinowitch Ithai , Segev Idan
Published: March 2006

Homeostatic synaptic plasticity (HSP) is an important mechanism attributed with the slow regulation of the neuron's activity. Whenever activity is chronically enhanced, HSP weakens the weights of the synapses in the dendrites and vice versa. Because dendritic morphology and its electrical properties partition the dendritic tree into functional compartments, we set out to explore the interplay between HSP and dendritic compartmentalization. For this purpose, we used a detailed model of a CA1 pyramidal neuron receiving a large number of activity-dependent plastic synapses and developed a novel approach for specifying functional dendritic subunits. We found that the degree of dendritic compartmentalization and the location-specificity of HSP are strongly tied. A local HSP mechanism, operating at the level of the individual synapse, will regard the neuron as a multiunit distributed system, each unit consisting of many synapses, and will thus support dendritic compartmentalization, whereas a global HSP mechanism, modifying all synapses in unison, will treat the neuron as a single centralized unit. Both local and global HSP can successfully counterbalance persistent, cell-wide perturbations of dendritic activity. The spatial distribution of synaptic weights throughout the dendrites will markedly differ under the local versus global HSP mechanisms. We suggest an experimental paradigm to unravel which type of HSP mechanism operates in the dendritic tree. The answer to this question will have important implications to our understanding of the functional organization of the neuron.
Responses of Neurons in Primary Auditory Cortex (A1) to Pure Tones in the Halothane-Anesthetized Cat
Authors: Moshitch Dina , Las Liora , Ulanovsky Nachum , Bar-Yosef Omer , Nelken Israel
Published: March 2006

The responses of primary auditory cortex (A1) neurons to pure tones in anesthetized animals are usually described as having mostly narrow, unimodal frequency tuning and phasic responses. Thus A1 neurons are believed not to carry much information about pure tones beyond sound onset. In awake cats, however, tuning may be wider and responses may have substantially longer duration. Here we analyze frequency-response areas (FRAs) and temporal-response patterns of 1,828 units in A1 of halothane-anesthetized cats. Tuning was generally wide: the total bandwidth at 40 dB above threshold was 4 octaves on average. FRA shapes were highly variable and many were diffuse, not fitting into standard classification schemes. Analyzing the temporal patterns of the largest responses of each unit revealed that only 9% of the units had pure onset responses. About 40% of the units had sustained responses throughout stimulus duration (115 ms) and 13% of the units had significant and informative responses lasting 300 ms and more after stimulus offset. We conclude that under halothane anesthesia, neural responses show many of the characteristics of awake responses. Furthermore, A1 units maintain sensory information in their activity not only throughout sound presentation but also for hundreds of milliseconds after stimulus offset, thus possibly playing a role in sensory memory.
Effects of Noise Correlations on Information Encoding and Decoding
Authors: Averbeck Bruno B. , Lee Daeyeol
Published: March 2006

Response variability is often correlated across populations of neurons, and these noise correlations may play a role in information coding. In previous studies, this possibility has been examined from the encoding and decoding perspectives. Here we used d prime and related information measures to examine how studies of noise correlations from these two perspectives are related. We found that for a pair of neurons, the effect of noise correlations on information decoding can be zero when the effect of noise correlations on the information encoded obtains its largest positive or negative values. Furthermore, there can be no effect of noise correlations on the information encoded when it has an effect on information decoding. We also measured the effect of noise correlations on information encoding and decoding in simultaneously recorded neurons in the supplementary motor area to see how well d prime accounted for the information actually present in the neural responses and to see how noise correlations affected encoding and decoding in real data. These analyses showed that d prime provides an accurate measure of information encoding and decoding in our population of neurons. We also found that the effect of noise correlations on information encoding was somewhat larger than the effect of noise correlations on information decoding, but both were relatively small. Finally, as predicted theoretically, the effects of correlations were slightly greater for larger ensembles (3–8 neurons) than for pairs of neurons.
Physiological Insights Into the Social-Context-Dependent Changes in the Rhythm of the Song Motor Program
Authors: Cooper Brenton G. , Goller Franz
Published: March 2006

Precisely timed behaviors are central to the survival of almost all organisms. Song is an example of a learned behavior under exquisite temporal control. Song tempo in zebra finches ( Taeniopygia guttata) is systematically modified depending on social context. When male zebra finches sing to females (directed), it is produced with a faster motor pattern compared with when they sing in isolation (undirected). We measured heart rate and air sac pressure during directed and undirected singing to quantify motivation levels and respiratory timing. Heart rate was significantly higher when male birds sang to females and was negatively correlated with song duration. The change in song tempo between directed and undirected song was accounted for by varying the duration of vocal expiratory events, whereas the duration of silent inspirations was unchanged. Song duration increased with repeated singing during directed song bouts, which was caused by a uniform increase in the duration of both expirations and inspirations. These results illustrate the importance of motivational state in regulating song tempo and demonstrate that multiple timing oscillators are necessary to control the rhythm of song. At least two different neural oscillators are required to control context-dependent changes in song tempo. One oscillator controlling expiratory duration varies as function of social context and another controlling inspiratory duration is fixed. In contrast, the song tempo change affecting expiratory and inspiratory duration within a directed bout of song could be achieved by slowing the output of a single oscillator.
Metabolic Energy Cost of Action Potential Velocity
Authors: Crotty Patrick , Sangrey Thomas , Levy William B
Published: March 2006

The action potential of the unmyelinated nerve is metabolically expensive. Using the energetic cost per unit length for the biophysically modeled action potential of the squid giant axon, we analyze this cost and identify one possible optimization. The energetic cost arising from an action potential is divided into three separate components: 1) the depolarization of the rising phase; 2) the hyperpolarization of the falling phase; and 3) the largest component, the overlapping of positive and negative currents, which has no electrical effect. Using both the Hodgkin–Huxley (HH) model and an improved version of the HH model (HHSFL), we investigate the variation of these three components as a function of easily evolvable parameters, axon diameter and ion channel densities. Assuming conduction velocity is well designed for each organism, the energy component associated with the rising phase attains a minimum near the biological values of the diameter and channel densities. This optimization is explained by the membrane capacitance per unit length. The functional capacitance is the sum of the intrinsic membrane capacitance and the gating capacitance associated with the sodium channel, and this capacitance minimizes at nearly the same values of diameter and channel density. Because capacitance is temperature independent and because this result is independent of the assumed velocity, the result generalizes to unmyelinated mammalian axons. That is, channel density is arguably an evolved property that goes hand-in-hand with the evolutionary stability of the sodium channel.
Transcriptome analysis of the ischemia-reperfused remodeling myocardium: temporal changes in inflammation and extracellular matrix
Authors: Roy Sashwati , Khanna Savita , Kuhn Donald E. , Rink Cameron , Williams Willis T. , Zweier Jay L. , Sen Chandan K.
Published: March 2006

cDNA microarray analysis was performed to screen 15,000 genes and expressed sequence tags (ESTs) to identify changes in the ischemia-reperfused (I-R) rat myocardial transcriptome in the early ( day 2) and late ( day 7) inflammatory phases of acute myocardial infarction. Lists of candidate genes that were affected by I-R transiently (2 or 7 days only) or on a more sustained basis (2 and 7 days) were derived. The candidate genes represented three major functional categories: extracellular matrix, apoptosis, and inflammation. To expand on the findings from microarray studies that dealt with the two above-mentioned time points, tissues collected from days 0, 0.25, 2, 3, 5, and 7 after reperfusion were examined. Acute myocardial infarction resulted in upregulation of IL-6 and IL-18. Genes encoding extracellular matrix proteins such as types I and III collagen were upregulated in day 2, and that response progressively grew stronger until day 7 after I-R. Comparable response kinetics was exhibited by the candidate genes of the apoptosis category. Caspases-2, -3, and -8 were induced in response to acute infarction. Compared with the myocardial tissue from the sham-operated rats, tissue collected from the infarct region stained heavily positive for the presence of active caspase-3. Laser microdissection and pressure catapulting technology was applied to harvest infarct and adjacent noninfarct control tissue from a microscopically defined region in the rat myocardium. Taken together, this work presents the first evidence gained from the use of DNA microarrays to understand the molecular mechanisms implicated in the early and late inflammatory phases of the I-R heart.
Chicken genomics resource: sequencing and annotation of 35,407 ESTs from single and multiple tissue cDNA libraries and CAP3 assembly of a chicken gene index
Authors: Carre Wilfrid , Wang Xiaofei , Porter Tom E. , Nys Yves , Tang Jianshan , Bernberg Erin , Morgan Robin , Burnside Joan , Aggrey Samuel E. , Simon Jean , Cogburn Larry A.
Published: March 2006

Its accessibility, unique evolutionary position, and recently assembled genome sequence have advanced the chicken to the forefront of comparative genomics and developmental biology research as a model organism. Several chicken expressed sequence tag (EST) projects have placed the chicken in 10th place for accrued ESTs among all organisms in GenBank. We have completed the single-pass 5′-end sequencing of 37,557 chicken cDNA clones from several single and multiple tissue cDNA libraries and have entered 35,407 EST sequences into GenBank. Our chicken EST sequences and those found in public databases (on July 1, 2004) provided a total of 517,727 public chicken ESTs and mRNAs. These sequences were used in the CAP3 assembly of a chicken gene index composed of 40,850 contigs and 79,192 unassembled singlets. The CAP3 contigs show a 96.7% match to the chicken genome sequence. The University of Delaware (UD) EST collection (43,928 clones) was assembled into 19,237 nonredundant sequences (13,495 contigs and 5,742 unassembled singlets). The UD collection contains 6,223 unique sequences that are not found in other public EST collections but show a 76% match to the chicken genome sequence. Our chicken contig and singlet sequences were annotated according to the highest BlastX and/or BlastN hits. The UD CAP3 contig assemblies and singlets are searchable by nucleotide sequence or key word ( http://cogburn.dbi.udel.edu ), and the cDNA clones are readily available for distribution from the chick EST website and clone repository ( http://www.chickest.udel.edu ). The present paper describes the construction and normalization of single and multiple tissue chicken cDNA libraries, high-throughput EST sequencing from these libraries, the CAP3 assembly of a chicken gene index from all public ESTs, and the identification of several nonredundant chicken gene sets for production of custom DNA microarrays.
The Prevalence of Diagnosed Cutaneous Manifestations during Ambulatory Diabetes Visits in the United States, 1998–2002
Authors: Wang Y. Richard , Margolis David
Published: March 2006

Background: The prevalence of diabetes has been rapidly increasing. Previous reports indicated that diabetics are prone to certain cutaneous diseases. Objective: To determine the frequencies of diagnosed skin conditions during ambulatory diabetes visits in the USA. Methods: We evaluated two national ambulatory medical care surveys between 1998 and 2002 and compared the diagnoses of 7 categories of skin conditions in diabetics (n = 9,626) to patients with hypertension (n = 15,997) or gastroesophageal reflux disease (GERD; n = 2,362) using χ2 tests and multivariate logistic regressions. Results: Diabetics were prone to chronic skin ulcers (odds ratio = 62.5, 95% confidence interval = 3.95–989 compared to GERD; 9.97, 6.34–15.7 compared to hypertension), bacterial skin infections (5.95, 2.86–12.4 compared to GERD; 5.15, 3.74–7.08 compared to hypertension) and fungal skin infections (2.66, 1.15–6.16 compared to GERD; 1.99, 1.32–3.01 compared to hypertension) but not to other skin conditions. These findings remained true during primary care physician visits. Conclusion: Chronic skin ulcers, bacterial and fungal skin infections are more frequently diagnosed in diabetics. We could not verify that other skin conditions are associated with diabetes, in part due to potential underdiagnosis and underreporting.
A Case of Pneumocystis jiroveci Pneumonia in X-Linked Agammaglobulinaemia Treated with Immunosuppressive Therapy: A Lesson for Immunologists
Authors: Sirianni Maria Caterina , Atzori Chiara , De Santis Wladimiro , Milito Cinzia , Esposito Antonella , Marziali Marco , Bernardi Maria Livia , Cargnel Antonietta , Aiuti Fernando
Published: March 2006

The case of a 20-year-old patient, affected by X-linked agammaglobulinaemia (XLA), who developed severe pneumonia from Pneumocystis jiroveci (formerly Pneumocystis carinii) (PCP), is reported. This infection usually affects patients with AIDS, children affected by severe combined immunodeficiency or hypogammaglobulinaemia with hyperimmunoglobulin M, or patients undergoing severe immunosuppression. The XLA patient developed PCP during therapy with steroids and cyclosporine A, carried out for several months, due to an extended skin vasculitis, accompanied by general symptoms. The pneumonia had a severe clinical course, requiring a long hospitalization. At the diagnosis of PCP, immunosuppressive therapy was suspended and the patient recovered after a long-term trimethoprim/sulfamethoxazole therapy. Immunological studies revealed an unexpected normal number of CD4+ and CD8+ T cells. The two subsets had an exclusive naïve phenotype (95% CD4+CD45RA+CD62L+ and 89% CD8+CD45RA+CD62L+ cells), with an absence of primed cells. Lymphoproliferative responses to P. carinii and recall antigens as well as to mitogens were extremely deficient. During the follow-up, memory cells appeared with recovery of the lymphoproliferative response to mitogens and maintained defective responses to antigens. This is one of the few reported XLA cases experiencing severe PCP. In this patient, the infection became clinically evident during immunosuppressive therapy. We believe that the absence of functional activities, despite a normal level of T lymphocyte counts, sustained this long-lasting infection. Thus, the CD4+ and CD8+ T cell count evaluation, without functional studies, may not be per se sufficient for predicting the risk of a severe clinical course of PCP in patients undergoing immunosuppression.