bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE CASE FOR RESEARCH ON THE EFFECTS OF ZEBRA MUSSELS IN LAKE ERIE: VISUALIZATION OF INFORMATION FROM AUGUST AND SEPTEMBER 1993
Authors: CHARLTON MURRAY N. 
Published: November 2004

Recent concern about the effects of Zebra mussels has centred on potential loss of fish production and potential loss of fish edibility. The mussels are thought to cause these effects by diversion of energy flow and alteration of contaminant processing. Because management options are limited to controls on nutrients and fish harvest/stocking, it is important to determine the extent and degree of Zebra Mussel effects. Some effects of the mussels are obvious in sheltered shallow areas but the effects on the whole ecosystem are not known. A series of research surveys done in 1993 is reported in this paper. The effects of the mussels seem to result in a loss of about 25 % of the standing algal biomass in some areas. Although an attempt was made to visit many areas of the lake, more extensive work is needed to find whole ecosystem effects. The difficulty in delineating the effects of the mussels is caused by the coincidental achievement of nutrient loading goals. Because the distribution of zebra mussels is uneven their effects may be found through extensive spatial surveys.
DEMONSTRATION OF 1/f FLUCTUATIONS AND WHITE NOISE IN THE HUMAN HEART RATE BY THE VARIANCE-TIME-CURVE: IMPLICATIONS FOR SELF-SIMILARITY
Authors: MEESMANN MALTE , BOESE JAN , CHIALVO DANTE R. , KOWALLIK PETER , BAUER WOLFGANG R. , PETERS WERNER , GRÜNEIS FERDINAND , KNIFFKI KLAUS-DIETRICH 
Published: November 2004

Spectral analysis of heart rate variability is usually performed by Fast Fourier Transform. Here we demonstrate the self-affine properties of the human heart rate using a spectral analysis based on counting statistics. Each QRS complex is considered to be a point event and from the number of events N(Δt) in consecutive time windows Δt the variance is calculated. From the finding that the variance of N(Δt) follows a power law proportional to (Δt)1+b in case of 1/fb noise, it is shown that the variance of the heart rate as determined for windows of length Δt, i.e., N(Δt)/Δt, is proportional to (Δt)b−1. From a 12-day Holter recording, the scaling region could be determined to cover 0.16 to 0.000136 Hz. A function X(t) is self-affine if X(t) and X(rt)/rH have the same distribution functions. From the variance-time-curve, it can be shown that the exponent H is dependent on b with b=2H−1. In young healthy men, the parameter b fluctuates between 0.2 and 1.0 during 24 h and thus determines the self-affine scaling factor H=(b−1)/2 for the amplitude of heart rate, if the time axis is scaled by r. Thus, during periods of 1/f noise, the heart rate scales with H=0, and for periods of almost white noise, with H close to [Formula: see text].
TEMPORAL FLUCTUATIONS IN BIORHYTHMS: EXPRESSION OF SELF-ORGANIZED CRITICALITY?
Authors: KNIFFKI KLAUS-D. , MANDEL WOLFGANG , TRAN-GIA PHUOC 
Published: November 2004

Recently, a general organizing principle has been reported connecting 1/f-noise with the self-similar scale-invariant ‘fractal’ properties in space, hence reflecting two sides of a coin, the so-called self-organized critical state. The basic idea is that dynamical systems with many degrees of freedom operate persistently far from equilibrium at or near a threshold of stability at the border of chaos. Temporal fluctuations which cannot be explained as consequences of statistically independent random events are found in a variety of physical and biological phenomena. The fluctuations of these systems can be characterized by a power spectrum density S(f) decaying as f−b at low frequencies with an exponent b<1.5. We present a new approach to describe the individual biorhythm of humans using data from a colleague who has kept daily records for two years of his state of well-being applying a fifty-point magnitude category scale. This time series was described as a point process by introducing two discriminating rating levels R for the occurrence of R≥40 and R≤10. For b<1 a new method to estimate the low frequency part of S(f) was applied using counting statistics without applying Fast Fourier Transform. The method applied reliably discriminates these types of fluctuations from a random point process, with b=0.0. It is very tempting to speculate that the neural mechanisms at various levels of the nervous system underlying the perception of different values of the subjective state of well-being, are expressions of a self-organized critical state.
INTERFACIAL AGGREGATION OF FLOATING MICROPARTICLES UNDER THE CONTROL OF SHORT-RANGE COLLOID AND VERY LONG-RANGE CAPILLARY FORCES
Authors: HÓRVÖLGYI Z. , ZRINYI M. 
Published: November 2004

Interfacial aggregation of surface modified glass beads (62–74 μm diameter) at water/air interface was carried out by using two differently hydrophobic samples, respectively. The effect of aggregation time on the self-similar structure of forming aggregates was studied comparing the actual results to those obtained previously.1 The time dependence of restructuring from the point of view of fractal geometry has been proved but the results call attention to another time dependent process— orientation of growing clusters during their collisions due to anisotropy of cluster-cluster interactions.
SOME LONG-RUN PROPERTIES OF CLIMATIC RECORDS
Authors: BODRI L. 
Published: November 2004

Fractal analysis allows for a mathematical comparison of climatic changes obtained from a variety of observations and recorded at different time scales. Analysis of the oxygen isotope curve of Pacific core V28–239 indicated fractal geometry of the oxygen isotope record for time scales 5000 to 2000000 years, with a fractal dimension of 1.22. On a time scale of some hundred years, tree ring index values yield an average fractal dimension of 1.32±0.02. For annual precipitation records from between 1817 and 1963 at nine major cities in the United States, a mean fractal dimension of 1.26±0.03 was found. Analysis of the annual mean surface air temperatures at seven meteorological stations in Hungary for the period of 1901–1991, indicates that the considered temperatures are fractals with a mean fractal dimension of 1.23±0.01. For the global surface air temperature change estimated from meteorological station records from 1880 to 1985, we derive in the present study a fractal dimension of 1.21. It is reasonable therefore to assume that climatic changes are characterized by one general fractal dimension over the spectral range 10 to 106 years. Records with such values of fractal dimension have some long-term persistence: even observations sufficiently distant from each other are not completely independent. If these conclusions become confirmed through analysis of a wider set of climatic records, long-run climatic prediction (in statistical sense) on different time scales will appear feasible.
NUMERICAL ESTIMATES OF THE FRACTAL DIMENSION D AND THE LACUNARITY L BY THE MASS RADIUS RELATION
Authors: OBERT MARTIN 
Published: November 2004

The mass radius relation (mrr) allows the estimation of a local fractal dimension Dl, which depends on a chosen site l of a set, taken as center position for the mrr. We find an unexpected wide range of Dl-values for a numerically analyzed Sierpinski triangle. The analysis of a computer simulation of a biological branching pattern shows rather small Dl-values at the border lines to major empty areas and rather high Dl-values in densely grown regions. The local impression by many Dl of a growth pattern can be interpreted biologically as an inverse measure of, for example, the local immune activity in a living object. We also apply the mrr to investigate the lacunarity L of Cantor dusts. Since numerical difficulties to obtain L are based on the finiteness of a set, we analyze projections of fractals on the unit circle, such that a well-defined largest possible gap size is introduced. The first preliminary results imply rather stable numerical values for L and D for many sets, where D is the average over many Dl. L depends on the size of the smallest details in a set. L is larger if many different gap sizes are given in a generator for a fractal curve as opposed to curves, where only one gap size is given. We assume that a totally different approach has to be set up to obtain L numerically of sets of finite size, since projections of sets or the introduction of periodic boundaries seem inadequate.
TWO VERSIONS OF QUASI-NEWTON METHOD FOR MULTIDIMENSIONAL INVERSE SCATTERING PROBLEM
Authors: GUTMAN SEMION , KLIBANOV MICHAEL 
Published: November 2004

Suppose that a medium with slowly changing spatial properties is enclosed in a bounded 3-dimensional domain and is subjected to a scattering by plane waves of a fixed frequency. Let measurements of the wave scattering field induced by this medium be available in the region outside of this domain. We study how to extract the properties of the medium from the information contained in the measurements. We are concerned with the weak scattering case of the above inverse scattering problem (ISP), that is, the unknown. spatial variations of the medium are assumed to be close to a constant. Examples can be found in the studies of the wave propagation in oceans, in the atmosphere, and in some biological media. Since the problems are nonlinear, the methods for their linearization (the Born approximation) have been developed. However, such an approach often does not produce good results. In our method, the Born approximation is just the first iteration and further iterations improve the identification by an order of magnitude. The iterative sequence is defined in the framework of a Quasi-Newton method. Using the measurements of the scattering field from a carefully chosen set of directions we are able to recover (finitely many) Fourier coefficients of the sought parameters of the model. Numerical experiments for the scattering from coaxial circular cylinders as well as for simulated data are presented.
AN APPROACH TO GOAL-ORIENTED REASONING BASED ON FUZZY SETS
Authors: FATHI MADJID , HÖFFMANN ACHIM 
Published: November 2004

In this paper concepts for goal-oriented reasoning within the blackboard development environment QBB are presented. The architecture of QBB supports the selection of problem solving actions with respect to the achivement of quality goals. Furthermore, interactions of goals are explicitly taken into account in action selection. The features of QBB to support goal-oriented reasoning are presented. Especially, it is described how mutual influence of actions with respect to goal achievement can explicitly modeled as relationships between actions, the so-called compensation relations. The usefullness of compensation relations has been tested by goal-oriented modeling of the travelling salesman problem.
MOVING SINGAPORE ENTREPRENEURSHIP TO NEW HEIGHTS
Authors: MUN CHEANG BERNARD BOEY , SIEW HOON SUSAN CHIAM-LEE 
Published: November 2004

Over the last three decades, Singapore had achieved a rate of economic progress equalled by few countries in the world. From a poor under-developed country with a per capita GNP of less than S$1000 in 1960, Singapore is today a newly industrialised economy with a per capita GNP of about S$24,000 and with full employment. Since the start of its industrialisation programme, Singapore has pursued actively a strategy to promote foreign investment, and this has been a major factor in its rapid economic growth, to the point that foreign investment policy is almost synonymous with its industrialisation strategy. However, changes in the business climate such as the economic slowdown in the industrialised world, growing global protectionism, spiralling business costs, changes in foreign investment patterns, just to identify some worrying trends, have led the government and the business community to work on developing a “second wing”. Singapore had leap-frogged the competition in earlier decades by riding piggyback on multinational corporations and this helped Singapore grow “one wing”— its domestic economy. Now the challenge is to nurture a new breed of entrepreneurs who can help Singapore to strengthen its domestic economy and also to seize opportunities to develop the second wing by way of an external economy that will see an increasing number of local companies venturing into the region.
Effects of Atorvastatin on Lipid Profile and Non-Traditional Cardiovascular Risk Factors in Diabetic Patients on Hemodialysis
Authors: Navarro Juan F. , Mora Carmen , Muros Mercedes , García-Idoate Gabriela 
Published: November 2004

<i>Background/Aims:</i> Dyslipidemia and non-traditional cardiovascular (CV) risk factors, such as lipoprotein(a) (Lp(a)), homocysteine, oxidative stress and inflammation, are important determinants in the increased CV risk of hemodialysis (HD) patients. The aim of our study was to evaluate the effects of atorvastatin on these parameters in one of the groups with the highest CV risk: diabetic patients with end-stage renal disease under HD therapy. <i>Methods:</i> Twenty maintenance HD diabetic patients (mean age 64 ± 10 years, mean time on HD 25 ± 11 months) with low-density lipoprotein cholesterol (LDL-C) >2.59 mmol/l received atorvastatin (10 mg/day) for 4 months. Lipid profile, including total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apolipoproteins A1 and B (Apo-A and Apo-B), and the non-traditional risk factors Lp(a), homocysteine, autoantibodies against oxidized LDL-C (anti-LDLox), total antioxidant status (TAS), and high sensitive C-reactive protein (hs-CRP), were measured at baseline and at the end of the study. Safety was assessed by clinical and laboratory (liver and muscle enzymes) monitoring once a month. <i>Results:</i> Mean percent reductions for TC, LDL-C and TG were 18.5% (p < 0.001), 22% (p < 0.001) and 19% (p < 0.01), respectively. The ratios of TC/HDL-C and LDL-C/HDL-C decreased after treatment (p < 0.05), whereas the ratios of LDL-C/Apo-B (p < 0.01) and Apo-A/Apo-B (p < 0.001) increased. No significant changes were observed in HDL-C. Concerning the non-traditional risk factors, levels of homocysteine, Lp(a), anti-LDLox and TAS did not change significantly. However, hs-CRP decreased from 5.4 (range 0.9–67.8) to 2.3 mg/l (range 0.4–21) (p < 0.01), whereas a concomitant increase in serum albumin was observed (from 38 ± 2 to 40 ± 1.7 g/l, p < 0.01). At baseline, hs-CRP was inversely associated with HDL-C and Apo-A, and directly related to Lp(a). The change in hs-CRP was inversely associated with the change of HDL-C, whereas a direct correlation was found with the change of TG. <i>Conclusions:</i> Atorvastatin administration to diabetic patients on HD is associated with improvement of lipid profile and reduction of hs-CRP. These effects may be critical for the reduction of CV risk and mortality in HD population.
Angiogenesis in Symptomatic Intracranial Atherosclerosis
Authors: Arenillas Juan F. , Álvarez-Sabín José , Montaner Joan , Rosell Anna , Molina Carlos A. , Rovira Alex , Ribó Marc , Sánchez Esther , Quintana Manuel 
Published: November 2004

Background and Purpose—Angiogenesis may be beneficial in chronic myocardial and limb ischemia, but its role in intracranial atherosclerosis remains unknown. We aimed to investigate the relationship between the pro-angiogenic vascular endothelial growth factor (VEGF) and the anti-angiogenic endostatin, and the extent and risk of recurrence of symptomatic intracranial atherosclerosis.Methods—Of a total of 94 consecutive patients with symptomatic intracranial stenoses, 40 fulfilled all inclusion criteria. Intracranial stenoses were confirmed by magnetic resonance angiography. Magnetic resonance imaging (MRI) including diffusion-weighted sequences was conducted. Plasmatic VEGF and endostatin were determined from blood samples obtained 3 months after stroke onset, and patients were followed-up thereafter.Results—A total of 144 intracranial stenoses were confirmed (median number per patient=3). Endostatin/VEGF ratio gradually augmented with the increasing number of intracranial stenoses (r=0.35,P=0.02). Diabetes mellitus (OR, 6.04; CI, 1.1 to 32.2;P=0.03) and a higher endostatin/VEGF ratio (OR, 15.7; CI, 2.2 to 112.3;P=0.006) were independently associated with a greater extent of intracranial atherosclerosis. During a median follow-up of 13 months, 8 patients (20%) experienced a new cerebral ischemic event. A higher baseline endostatin concentration was an independent predictor of new events (hazard ratio, 7.24; CI, 1.6 to 33.8;P=0.011) in a Cox regression model after adjustment for age, sex, number of stenotic vessels, and risk factors. Patients with a higher endostatin level had a lower survival free of new events (P=0.01, log-rank test).Conclusions—A predominance of the inhibitor endostatin within the endogenous angiogenic response is associated with a greater extent and risk of recurrence of symptomatic intracranial atherosclerosis, suggesting that angiogenesis may be beneficial in this condition.
The learning of popular music: a pedagogical model for music educators
Authors: Winter Neal 
Published: November 2004

In order to evaluate the effects of an integrated curriculum on the learning of popular music, the Sting Curriculum was designed for senior secondary students of mixed ability. This nine-week program was presented to a sample of students aged between 16 and 18 years in urban Sydney (Australia). This article draws on some of the results from this broader study, examining the dynamic relationships between the three music learning activities of listening, performance, and composition, and extraneous variables (evident in the teacher and student samples). After a pilot study and implementation of the Sting Curriculum, student learning in popular music was measured using a specially constructed test. Test scores and data relating to the extraneous variables were analysed using stepwise multiple regression analysis, chi square (nonparametric) tests, and correlations using the Pearson r correlation coefficients function within SPSS for the Macintosh. The results indicate that students in the sample achieved high scores on the test when a greater emphasis was placed on performance than on the listening and composition activities. It is suggested that the Sting Curriculum was successful as a vehicle for learning popular music, providing students with an integrated and sequential program that motivated participants to become immersed in the music. In the context of an integrated curriculum, popular music learning was enhanced when teachers utilized a pedagogical approach which emphasized the performance activity.
Climatology of Dust Sources in North Africa and the Arabian Peninsula, Based on TOMS Data
Authors: Barkan J. , Kutiel H. , Alpert P. 
Published: November 2004

Aerosol Index ( AI) values from the TOMS instrument were used to compute AI climatology in Africa north of the equator and in the Saudi Arabian desert (30°W-60°E, 0°-50°), for the period 1979-1992. Monthly and annual averages are presented for the whole area as well as for 9 other source areas. The highest AI values were found in the summer months of May, June and July. The area around lake Chad has the highest value and, contrary to the other sources, is active throughout the year. The first 4 years of the research period has a significantly lower index value as compared with the later years. There is a sharp discontinuity between the years 1982 and 1983 in the western sources and a more moderate increase in the eastern sources. Two periods with very high AI values are identified, namely 1983-1984 and 1987-1988, while the year 1986 had a low index value. In 1991 and, to a lesser extent, in 1992, very high AI values were obtained in the eastern sources.
Jagged1-dependent Notch signaling is dispensable for hematopoietic stem cell self-renewal and differentiation
Authors: Mancini Stéphane J. C. , Mantei Ned , Dumortier Alexis , Suter Ueli , MacDonald H. Robson , Radtke Freddy 
Published: November 2004

AbstractJagged1-mediated Notch signaling has been suggested to be critically involved in hematopoietic stem cell (HSC) self-renewal. Unexpectedly, we report here that inducible Cre-loxP–mediated inactivation of the Jagged1 gene in bone marrow progenitors and/or bone marrow (BM) stromal cells does not impair HSC self-renewal or differentiation in all blood lineages. Mice with simultaneous inactivation of Jagged1 and Notch1 in the BM compartment survived normally following a 5FU-based in vivo challenge. In addition, Notch1-deficient HSCs were able to reconstitute mice with inactivated Jagged1 in the BM stroma even under competitive conditions. In contrast to earlier reports, these data exclude an essential role for Jagged1-mediated Notch signaling during hematopoiesis.
Functional characterization of telomerase RNA variants found in patients with hematologic disorders
Authors: Ly Hinh , Calado Rodrigo T. , Allard Paulette , Baerlocher Gabriela M. , Lansdorp Peter M. , Young Neal S. , Parslow Tristram G. 
Published: November 2004

AbstractHuman telomerase uses a specific cellular RNA, called hTERC, as the template to synthesize telomere repeats at chromosome ends. Approximately 10% to 15% of patients with aplastic anemia or other bone marrow failure syndromes are carriers of hTERC sequence variants whose functional significance, in most cases, is unknown. We screened 10 reported and 2 newly discovered hTERC variants from such patients and found that 10 of these negatively affected telomerase enzymatic function when they were used to reconstitute telomerase enzymatic function in human cells. Most functional deficits were due to perturbations of hTERC secondary structure and correlated well with the degrees of telomere shortening and reduced telomerase activity observed in peripheral blood lymphocytes of the representative patients. We also found no evidence of dominant-negative activity in any of the mutants. Therefore, loss of telomerase activity and of telomere maintenance resulting from inherited hTERC mutations may limit marrow stem cell renewal and predispose some patients to bone marrow failure.
α1A-Adrenoceptors Activate Glucose Uptake in L6 Muscle Cells through a Phospholipase C-, Phosphatidylinositol-3 Kinase-, and Atypical Protein Kinase C-Dependent Pathway
Authors: Hutchinson Dana S. , Bengtsson Tore 
Published: November 2004

AbstractThe role of α1-adrenoceptor activation on glucose uptake in L6 cells was investigated. The α1-adrenoceptor agonist phenylephrine [pEC50 (−log10 EC50), 5.27 ± 0.30] or cirazoline (pEC50, 5.00 ± 0.23) increased glucose uptake in a concentration-dependent manner, as did insulin (pEC50, 7.16 ± 0.21). The α2-adrenoceptor agonist clonidine was without any stimulatory effect on glucose uptake. The stimulatory effect of cirazoline was inhibited by the α1-adrenoceptor antagonist prazosin, but not by the β-adrenoceptor antagonist propranolol. RT-PCR showed that the α1A-adrenoceptor was the sole α1-adrenoceptor subtype expressed in L6 cells. Cirazoline- or insulin-mediated glucose uptake was inhibited by the phosphatidylinositol-3 kinase inhibitor LY294002, suggesting a possible interaction between the α1-adrenoceptor and insulin pathways. Cirazoline or insulin stimulated phosphatidylinositol-3 kinase activity, but α1-adrenoceptor activation did not phosphorylate Akt. Both cirazoline- and insulin-mediated glucose uptake were inhibited by protein kinase C (PKC), phospholipase C, and p38 kinase inhibitors, but not by Erk1/2 inhibitors (despite both treatments being able to phosphorylate Erk1/2). Insulin and cirazoline were able to activate and phosphorylate p38 kinase. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate and the calcium ionophore A23187 produced significant increases in glucose uptake, indicating roles for PKC and calcium in glucose uptake. Down-regulation of conventional PKC isoforms inhibited glucose uptake mediated by 12-O-tetradecanoylphorbol-13-acetate, but not by insulin or cirazoline. This study demonstrates that α1-adrenoceptors mediate increases in glucose uptake in L6 muscle cells. This effect appears to be related to activation of phospholipase C, phosphatidylinositol-3 kinase, p38 kinase, and PKC.