bluuebunny/crossref_metadata_2025 huggingface dataset:
Noise Induced Multi-Mode Neural Firings in a Period Adding Bifurcation Scenario
Authors: Gu Huaguang , Yang Minghao , Li Li , Liu Zhiqiang , Ren Wei
Published: October 2003

A series of new firing patterns lying between two kinds of periodic bursting patterns and randomly alternating on the two kinds of periodic bursts, were discovered in the experiment on neural pacemaker and induced by noise in Chay model near each bifurcation point in a period adding bifurcation scenario without chaos, exhibiting multi-mode characteristics that was the signature of autonomous stochastic resonance in neuronal firing. Two endogenous characteristics near each bifurcation point that made noise induce the new firing patterns were identified. One was that there existed critical phase between the trajectories of the two kinds of bursting patterns. The other was that the periods of the two kinds of bursting patterns near each bifurcation point were small.
Controlling Chaos in a Neural Network Based on the Phase Space Constraint
Authors: He Guoguang , Cao Zhitong , Chen Hongping , Zhu Ping
Published: October 2003

The chaotic neural network constructed with chaotic neurons exhibits very rich dynamic behaviors and has a nonperiodic associative memory. In the chaotic neural network, however, it is difficult to distinguish the stored patters from others, because the states of output of the network are in chaos. In order to apply the nonperiodic associative memory into information search and pattern identification, etc, it is necessary to control chaos in this chaotic neural network. In this paper, the phase space constraint method focused on the chaotic neural network is proposed. By analyzing the orbital of the network in phase space, we chose a part of states to be disturbed. In this way, the evolutional spaces of the strange attractors are constrained. The computer simulation proves that the chaos in the chaotic neural network can be controlled with above method and the network can converge in one of its stored patterns or their reverses which has the smallest Hamming distance with the initial state of the network. The work clarifies the application prospect of the associative dynamics of the chaotic neural network.
Transport of Heap Formed by Granular Materials on an Inclined Surface
Authors: Huang Kai , Miao Guoqing , Wei Rongjue
Published: October 2003

We study experimentally the transport of heap formed by granular materials vertically vibrated on an inclined surface. A relationship is presented of how the velocity of heap changing with driving acceleration and frequency. The shape of the heap bottom is measured by detecting the colliding phase of the heap bottom with plane. An analogous experiment is performed with a heap shape block of Plexiglas. The mechanism for transport of the heap is presented.
Factors of the Transition from Dilute Flow to Dense Flow in Two-Dimensional Channel
Authors: Zhang Xun-Sheng , Bao De-Song , Xu Guang-Lei , Hu Guo-Qi , Pan Zheng-Quan , Chen Wei , Hou Mei-Ying , Lu Kun-Quan
Published: October 2003

Granular flow of steel beads from dilute flow to dense flow on an inclined two-dimensional channel is studied. The initial inflow Q0 is always a dilute flow. A transition from dilute to dense is observed when D≤Dc. In the dense flow the outflow rate (Q) depends only on opening (D), given by [Formula: see text]. For different inflow rate Q0 in the dilute flow case, the relation between the transition critical exit width (Dc) and the channel width (W) is given. And in larger inflow, the critical exit width is approximately in proportion to the square root of inflow rate, [Formula: see text].
A Parallel Implementation of a Computational Aeroacoustic Algorithm for Airfoil Noise
Authors: Lockard David P. , Morris Philip J.
Published: October 2003

The long-term objective of the research described in this paper is to use CAA methodology and parallel computers to increase the understanding of broadband blade noise. In a systematic progression towards simulations of completely realistic configurations and conditions, some simplified problems that address the important features of the flow are investigated. A two-dimensional, Euler code, implemented using the message passing library and Fortran 90 on the IBM SP2, is used to perform the calculations. Results are presented for the interaction of a vortical gust and a flat plate.
Second-Order Fourier Synthesis of Broadband Acoustic Signals Using Normal Modes
Authors: Skarsoulis E. K.
Published: October 2003

A scheme for approximate normal-mode calculation of broadband acoustic signals in the time domain is proposed based on a second-order Taylor expansion of eigenvalues and eigenfunctions with respect to frequency. For the case of a Gaussian impulse source a closed-form expression is derived for the pressure in the time domain. Using perturbation theory, analytical expressions are obtained for the involved first and second frequency-derivatives of eigenvalues and eigenfunctions. The proposed approximation significantly accelerates arrival-pattern calculations, since the eigenvalues, the eigenfunctions and their frequency-derivatives need to be calculated at a single frequency, the central frequency of the source. Furthermore, it offers a satisfactory degree of accuracy for the lower and intermediate order modes. This is due to the fact that essential wave-theoretic mechanisms such as dispersion and frequency dependence of mode amplitudes are contained in the representation up to a sufficient order. Numerical results demonstrate the efficiency of the method.
Synthesis of progressively-variant textures on arbitrary surfaces
Authors: Zhang Jingdan , Zhou Kun , Velho Luiz , Guo Baining , Shum Heung-Yeung
Published: October 2003

We present an approach for decorating surfaces with
progressively-variant textures
. Unlike a homogeneous texture, a progressively-variant texture can model local texture variations, including the scale, orientation, color, and shape variations of texture elements. We describe techniques for modeling progressively-variant textures in 2D as well as for synthesizing them over surfaces. For 2D texture modeling, our
feature-based
warping technique allows the user to control the shape variations of texture elements, making it possible to capture complex texture variations such as those seen in animal coat patterns. In addition, our
feature-based blending
technique can create a smooth transition between two given homogeneous textures, with progressive changes of both shapes and colors of texture elements. For synthesizing textures over surfaces, the biggest challenge is that the synthesized texture elements tend to break apart as they progressively vary. To address this issue, we propose an algorithm based on texton masks, which mark most prominent texture elements in the 2D texture sample. By leveraging the power of texton masks, our algorithm can maintain the integrity of the synthesized texture elements on the target surface.
Fragment-based image completion
Authors: Drori Iddo , Cohen-Or Daniel , Yeshurun Hezy
Published: October 2003

We present a new method for completing missing parts caused by the removal of foreground or background elements from an image. Our goal is to synthesize a complete, visually plausible and coherent image. The visible parts of the image serve as a training set to infer the unknown parts. Our method iteratively approximates the unknown regions and composites adaptive image fragments into the image. Values of an inverse matte are used to compute a confidence map and a level set that direct an incremental traversal within the unknown area from high to low confidence. In each step, guided by a fast smooth approximation, an image fragment is selected from the most similar and frequent examples. As the selected fragments are composited, their likelihood increases along with the mean confidence of the image, until reaching a complete image. We demonstrate our method by completion of photographs and paintings.
Globally smooth parameterizations with low distortion
Authors: Khodakovsky Andrei , Litke Nathan , Schröder Peter
Published: October 2003

Good parameterizations are of central importance in many digital geometry processing tasks. Typically the behavior of such processing algorithms is related to the smoothness of the parameterization and how much distortion it contains. Since a parameterization maps a bounded region of the plane to the surface, a parameterization for a surface which is not homeomorphic to a disc must be made up of multiple pieces. We present a novel parameterization algorithm for arbitrary topology surface meshes which computes a
globally
smooth parameterization with low distortion. We optimize the patch layout subject to criteria such as shape quality and metric distortion, which are used to steer a mesh simplification approach for base complex construction. Global smoothness is achieved through simultaneous relaxation over all patches, with suitable transition functions between patches incorporated into the relaxation procedure. We demonstrate the quality of our parameterizations through numerical evaluation of distortion measures and the excellent rate distortion performance of semi-regular remeshes produced with these parameterizations. The numerical algorithms required to compute the parameterizations are robust and run on the order of minutes even for large meshes.
Clustered principal components for precomputed radiance transfer
Authors: Sloan Peter-Pike , Hall Jesse , Hart John , Snyder John
Published: October 2003

We compress storage and accelerate performance of precomputed radiance transfer (PRT), which captures the way an object shadows, scatters, and reflects light. PRT records over many surface points a transfer matrix. At run-time, this matrix transforms a vector of spherical harmonic coefficients representing distant, low-frequency source lighting into exiting radiance. Per-point transfer matrices form a high-dimensional surface signal that we compress using
clustered principal component analysis
(CPCA), which partitions many samples into fewer clusters each approximating the signal as an affine subspace. CPCA thus reduces the high-dimensional transfer signal to a low-dimensional set of per-point weights on a per-cluster set of representative matrices. Rather than computing a weighted sum of representatives and applying this result to the lighting, we apply the representatives to the lighting per-cluster (on the CPU) and weight these results per-point (on the GPU). Since the output of the matrix is lower-dimensional than the matrix itself, this reduces computation. We also increase the accuracy of encoded radiance functions with a new least-squares optimal projection of spherical harmonics onto the hemisphere. We describe an implementation on graphics hardware that performs real-time rendering of glossy objects with dynamic self-shadowing and interreflection without fixing the view or light as in previous work. Our approach also allows significantly increased lighting frequency when rendering diffuse objects and includes subsurface scattering.
Layered acting for character animation
Authors: Dontcheva Mira , Yngve Gary , Popović Zoran
Published: October 2003

We introduce an acting-based animation system for creating and editing character animation at interactive speeds. Our system requires minimal training, typically under an hour, and is well suited for rapidly prototyping and creating expressive motion. A real-time motion-capture framework records the user's motions for simultaneous analysis and playback on a large screen. The animator's real-world, expressive motions are mapped into the character's virtual world. Visual feedback maintains a tight coupling between the animator and character. Complex motion is created by layering multiple passes of acting. We also introduce a novel motion-editing technique, which derives implicit relationships between the animator and character. The animator mimics some aspect of the character motion, and the system infers the association between features of the animator's motion and those of the character. The animator modifies the mimic by acting again, and the system maps the changes onto the character. We demonstrate our system with several examples and present the results from informal user studies with expert and novice animators.
The space of human body shapes
Authors: Allen Brett , Curless Brian , Popović Zoran
Published: October 2003

We develop a novel method for fitting high-resolution template meshes to detailed human body range scans with sparse 3D markers. We formulate an optimization problem in which the degrees of freedom are an affine transformation at each template vertex. The objective function is a weighted combination of three measures: proximity of transformed vertices to the range data, similarity between neighboring transformations, and proximity of sparse markers at corresponding locations on the template and target surface. We solve for the transformations with a non-linear optimizer, run at two resolutions to speed convergence. We demonstrate reconstruction and consistent parameterization of 250 human body models. With this parameterized set, we explore a variety of applications for human body modeling, including: morphing, texture transfer, statistical analysis of shape, model fitting from sparse markers, feature analysis to modify multiple correlated parameters (such as the weight and height of an individual), and transfer of surface detail and animation controls from a template to fitted models.
Structured importance sampling of environment maps
Authors: Agarwal Sameer , Ramamoorthi Ravi , Belongie Serge , Jensen Henrik Wann
Published: October 2003

We introduce
structured importance sampling
, a new technique for efficiently rendering scenes illuminated by distant natural illumination given in an environment map. Our method handles occlusion, high-frequency lighting, and is significantly faster than alternative methods based on Monte Carlo sampling. We achieve this speedup as a result of several ideas. First, we present a new metric for stratifying and sampling an environment map taking into account both the illumination intensity as well as the expected variance due to occlusion within the scene. We then present a novel hierarchical stratification algorithm that uses our metric to automatically stratify the environment map into regular strata. This approach enables a number of rendering optimizations, such as pre-integrating the illumination within each stratum to eliminate noise at the cost of adding bias, and sorting the strata to reduce the number of sample rays. We have rendered several scenes illuminated by natural lighting, and our results indicate that structured importance sampling is better than the best previous Monte Carlo techniques, requiring one to two orders of magnitude fewer samples for the same image quality.
Mathematical reasoning in software engineering education
Authors: Henderson Peter B.
Published: October 2003

Discrete mathematics, especially logic, plays an implicit role in software engineering similar to the role of continuous mathematics in traditional physically based engineering disciplines.
Survey of code-size reduction methods
Authors: Beszédes Árpád , Ferenc Rudolf , Gyimóthy Tibor , Dolenc André , Karsisto Konsta
Published: October 2003

Program code compression is an emerging research activity that is having an impact in several production areas such as networking and embedded systems. This is because the reduced-sized code can have a positive impact on network traffic and embedded system costs such as memory requirements and power consumption. Although code-size reduction is a relatively new research area, numerous publications already exist on it. The methods published usually have different motivations and a variety of application contexts. They may use different principles and their publications often use diverse notations. To our knowledge, there are no publications that present a good overview of this broad range of methods and give a useful assessment. This article surveys twelve methods and several related works appearing in some 50 papers published up to now. We provide extensive assessment criteria for evaluating the methods and offer a basis for comparison. We conclude that it is fairly hard to make any fair comparisons of the methods or draw conclusions about their applicability.
Where are the micropayments?
Authors: Treese Win
Published: October 2003

Since Internet commerce began in earnest nearly ten years ago, people have talked about the need for systems that allow small payments for digital content. Many systems for such payments---often called "micropayments"---have been devised, and many companies have tried to bring them to market. To date, none have succeeded, but every couple of years a new round of companies try again. Is it likely that one or more will make it in the future?
Intelligent Web services moving toward a framework to compose
Authors: Van Den Heuvel Willem-Jan , Maamar Zakaria
Published: October 2003

Intelligent Web services show promise as a means of supporting cross-organizational business transactions.
Self-Control, Social Consequences, and Criminal Behavior: Street Youth and the General Theory of Crime
Authors: Baron Stephen W.
Published: October 2003

Using a sample of 400 homeless street youth, this article examines the role that self-control plays in the generation of crime and drug use as well as its link to negative social consequences. It also explores if these social consequences are themselves related to crime as predicted in strain and differential association theory, or if their impact is eliminated by the presence of low self-control. The results reveal that low self-control predicts a range of criminal behaviors as well as drug use. Consistent with the general theory, low self-control influences the association with deviant peers, the adoption of deviant values, length of unemployment, and length of homelessness. However, the results reveal that a number of social consequences; including deviant peers, deviant values, length of homelessness, relative deprivation, and monetary dis-satisfaction; have an effect on criminal behavior and drug use controlling for self-control lending support to other theoretical perspectives. Results are discussed in terms of developing the general theory by incorporating other perspectives.
Individual Difference in the Pharmacokinetics of a Drug, Pravastatin, in Healthy Subjects
Authors: Ogawa Katsutoshi , Hasegawa Setsuo , Udaka Yuko , Nara Keinosuke , Iwai Shinichi , Oguchi Katsuji
Published: October 2003

The purpose of this investigation was to determine whether there were individual pharmacokinetic differences of a drug, pravastatin. Furthermore, the percentage of subjects who showed pharmacokinetic differences was determined. A single oral dose of pravastatin 10 mg was administered to 84 Japanese healthy male subjects. Serum concentrations of pravastatin were measured for 8 hours postdose. Area under the concentration‐time curve (AUC) and peak concentration (Cmax) were determined as primary evaluation parameters. An outlier was defined as follows:

Outlier 1 < Q1 ‐ (Q3 ‐ Q1) × 1.5 or Q3 + (Q3 ‐ Q1) × 1.5 < Outlier 1,

Outlier 2 < Q1 ‐ (Q3 ‐ Q1) × 3 or Q3 + (Q3 ‐ Q1) × 3 < Outlier 2.

Subjects who were outliers were regarded as having an individual difference in pharmacokinetic behavior. In AUC and Cmax, 4 of 84 subjects (4.8%) were higher outliers. Of these 4 subjects, 2 were high outliers in both AUC and Cmax. No subjects were low outliers. It was concluded that a significant individual difference in the pharmacokinetics of pravastatin was observed in 4.8% of the subjects (4/84).
Adults' Attitudes Toward Multiracial Children
Authors: Chesley Gayle L. , Wagner William G.
Published: October 2003

A between-groups experimental design was used to examine adults' attitudes to-ward multiracial children of African descent. The purpose was to determine if the races of the respondent, the child, and the child's friends are related to adults' ratings of children's self-perception and depressive symptoms. A total of 156 undergraduate students (African American = 78,European American = 78) read a vignette in which the race of the target child (European American, African American, or multiracial) and the child's friends (European American or African American) were experimentally controlled. Participants assessed the child using a revision of Harter's Self-Perception Profile for Children and a revised version of Kovacs's Children's Depression Inventory—Short Form. Ratings of the child's global self-worth and depressive symptoms were negatively correlated. The results of a 2 X 2 X 3 MANOVA revealed a significant three-way interaction for the races of the child, the respondent, and the child's friends on adults' ratings of the child's peer acceptance. The implications of these findings are discussed.
Intercultural Health Care as Reflective Negotiated Practice
Authors: Fuller Jeffrey
Published: October 2003

This interpretive study sought to understand how intercultural health care to immigrants can be practically conceptualized in multicultural populations. Interviews were conducted with 20 Canadian health service informants, and 12 interviews were staged during 31 months with a multicultural coordinator in an Australian teaching hospital. Transcripts of 11 previously con-ducted group discussions with 34 staff members from this same Australian hospital were also included. Interpretation was based on these data as well as on the literature and the author's own experience. It was concluded that intercultural health care can be practically conceptualized as reflective health worker practice. Through this practice, responsive care can be situationally negotiated between the health worker and the client in a framework of jointly considered needs. For implementation, the barriers to negotiation must be addressed.
Transitional Supportive Housing Programs: Battered Women's Perspectives and Recommendations
Authors: Melbin Anna , Sullivan Cris M. , Cain Debra
Published: October 2003

Finding safe, affordable housing is one of the greatest obstacles that women who leave abusive partners face. In response, advocates for battered women have begun to offer transitional supportive housing (TSH) programs. This article reports on interviews with 55 key stakeholders of these programs (direct service staff, current participants, former participants, and shelter residents) to examine the degree to which TSH programs fulfill the needs of the women who use them. Consistent with other research on empowerment-based services, the study found that the women were most satisfied when services were provided in a respectful and individualized manner. The women's recommendations included the implementation of safety protocols and the need for a variety of support services that should be offered but not mandated.
Bringing E-Democracy Back In
Authors: Chadwick Andrew
Published: October 2003

The author argues that contemporary digital information communication technologies (ICTs) facilitate new forms of e-government-enabled public sector policy making that enshrine some of the important norms and practices of e-democracy. The potential for linking e-democracy in civil society with e-government at the level of the local and national state is far from straightforward but nevertheless achievable. Following a consideration of the democratization effects of e-democracy and e-government, the author outlines how their norms and practices are converging in four principal areas: online consultations integrating civil societal groups with bureaucracies and legislatures, the internal democratization of the public sector itself, the involvement of users in the design and delivery of public services, and the diffusion of open-source collaboration in public organizations. These now feature as some of the core areas for research in this field and our broader understanding of how ICTs are reshaping governance, the state, and democracy.
An Experimental Comparison of Computer-Mediated and Face-to-Face Focus Groups
Authors: Underhill Christina , Olmsted Murrey G.
Published: October 2003

Conducting focus groups via computers is becoming an increasingly popular method for collecting data. The main benefits of Internet-based focus groups include lower cost, no travel expenses, automatic capture of the discussion data, and the ability to reach remote populations for participation. Although Internet-based focus groups are popular, little research has been done to compare the quantity and quality of the information obtained from traditional face-to-face focus groups and computer-based focus groups. This study compared the quantity and quality of information gained from face-to-face and two computer-based focus group conditions. Results indicated conducting focus groups using a computer produces similar amounts of information. Most important, the quality of the information obtained from computer-based focus groups is not significantly different from information obtained from face-to-face groups. Varying the levels of social interaction to cause different levels of perceived social presence did not produce differences in the quality or quantity of information.
Depressive Symptoms and Physical Health of Caregivers of Persons with Cognitive Impairment
Authors: O'rourke Norm , Cappeliez Philippe , Guindon Sophie
Published: October 2003

Objective: Research indicates that caregivers of persons with cognitive impairment are at elevated risk for clinical depression. The current study examines the association between physical illness and depressive symptoms among caregivers over a 5-year interval. Methods: Participants were recruited as part of a longitudinal study of dementia prevalence in Canada ( N = 382). Persons with cognitive loss and their primary caregivers were randomly identified from each Canadian province. Results:Subsequent to control for sociodemographic variables, patient illness characteristics and initial depressive symptomatology, baseline health of caregivers contributed significantly to the prediction of depressive symptoms five years later. In contrast, depressive symptomatology was not a significant predictor of physical health over this same interval (again controlling for sociodemographic variables, patient illness characteristics, and caregivers' health at baseline). Discussion: These analyses pro-vided partial support for reciprocal effects between physical illness and depression. Findings are discussed in terms of the applicability of a model of reciprocal effects to older adults.
Using Average Cost Methods to Estimate Encounter-Level Costs for Medical-Surgical Stays in the VA
Authors: Wagner Todd H. , Chen Shuo , Barnett Paul G.
Published: October 2003

The U.S. Department of Veterans Affairs (VA) maintains discharge abstracts, but these do not include cost information. This article describes the methods the authors used to estimate the costs of VA medical-surgical hospitalizations in fiscal years 1998 to 2000. They estimated a cost regression with 1996 Medicare data restricted to veterans receiving VA care in an earlier year. The regression accounted for approximately 74 percent of the variance in cost-adjusted charges, and it proved to be robust to outliers and the year of input data. The beta coefficients from the cost regression were used to impute costs of VA medical-surgical hospital discharges. The estimated aggregate costs were reconciled with VA budget allocations. In addition to the direct medical costs, their cost estimates include indirect costs and physician services; both of these were allocated in proportion to direct costs. They discuss the method's limitations and application in other health care systems.
Direct Measurement of Health Care Costs
Authors: Smith Mark W. , Barnett Paul G.
Published: October 2003

Cost identification is fundamental to many economic analyses of health care. Health care costs are often derived from administrative databases. Unit costs may also be obtained from published studies. When these sources will not suffice (e.g., in evaluating interventions or programs), data may be gathered directly through observation and surveys. This article describes how to use direct measurement to estimate the cost of an intervention. The authors review the elements of cost determination, including study perspective, the range of elements to measure, and short-run versus long-run costs. They then discuss the advantages and drawbacks of alternative direct measurement methods such as time-and-motion studies, activity logs, and surveys of patients and managers. A parsimonious data collection effort is desirable, although study hypotheses and perspective should guide the endeavor. Special reference is made to data sources within the Department of Veterans Affairs (VA) health care system.
Intranodal Administration of Peptide-Pulsed Mature Dendritic Cell Vaccines Results in Superior CD8+T-Cell Function in Melanoma Patients
Authors: Bedrosian Isabelle , Mick Rosemarie , Xu Shuwen , Nisenbaum Harvey , Faries Mark , Zhang Paul , Cohen Peter A. , Koski Gary , Czerniecki Brian J.
Published: October 2003

Purpose: We evaluated the feasibility, safety, and immunogenicity of mature, peptide-pulsed dendritic cell (DC) vaccines administered by different routes.

Patients and Methods: We performed a randomized, phase I, dose-escalation study in 27 patients with metastatic melanoma receiving four autologous peptide-pulsed DC vaccinations. Patients were randomly assigned to an intravenous (IV), intranodal (IN), or intradermal (ID) route of administration (ROA). For each route, primary end points were dose-limiting toxicity, maximum-tolerated dose, and T-cell sensitization. Sensitization was evaluated through tetramer staining, in vitro peptide recognition assays, and delayed-type hypersensitivity (DTH) responses.

Results: Twenty-two (81.5%) of 27 patients completed all four vaccinations. Vaccinations were well tolerated; a few patients exhibited grade 1 to 2 toxicities including rash, fever, and injection site reaction. All routes of administration induced comparable increases in tetramer-staining CD8+T cells (five of seven IV, four of seven IN, and four of six ID patients). However, the IN route induced significantly higher rates for de novo development of CD8+T cells that respond by cytokine secretion to peptide-pulsed targets (six [85.7%] of seven IN patients v two [33%] of six ID patients v none [0%] of six IV patients; P = .005) and de novo DTH (seven [87.5%] of eight IN patients v two [33.3%] of six ID patients v one [14.3%] of seven IV patients; P = .01) compared with other routes.

Conclusion: Administration of this peptide-pulsed mature DC vaccine by IN, IV, or ID routes is feasible and safe. IN administration seems to result in superior T-cell sensitization as measured by de novo target-cell recognition and DTH priming, indicating that IN may be the preferred ROA for mature DC vaccines.
Electrical activity of caudal neurosecretory neurons in seawater- and freshwater-adapted flounder: responses to cholinergic agonists
Authors: Brierley M. J. , Ashworth A. J. , Craven T. P. , Woodburn M. , Banks J. R. , Lu W. , Riccardi D. , Balment R. J. , McCrohan C. R.
Published: October 2003

The caudal neurosecretory system (CNSS) of the euryhaline flounder is involved in osmoregulatory responses underlying adaptation to seawater and freshwater. This study compared electrophysiological activity and responses to cholinergic agonists in the neuroendocrine Dahlgren cells in an in vitro preparation taken from fully seawater- (SWA) or freshwater-adapted(FWA) fish. Resting membrane and action potential parameters showed few differences between SWA and FWA cells. The hyperpolarisation-activated sag potential and depolarising afterpotential were present under both conditions;however, amplitude of the latter was significantly greater in SWA cells. The proportions of cells within the population exhibiting different firing patterns were similar in both adaptation states. However, bursting parameters were more variable in FWA cells, suggesting that bursting activity was less robust. The muscarinic agonist, oxotremorine, was largely inhibitory in Dahlgren cells, but increased activity in a non-Dahlgren cell population,α neurons. Nicotine promoted bursting activity in SWA Dahlgren cells,whereas it inhibited over half of FWA cells.
Seismic signals in a courting male jumping spider (Araneae:Salticidae)
Authors: Elias Damian O. , Mason Andrew C. , Maddison Wayne P. , Hoy Ronald R.
Published: October 2003

Visual displays in jumping spiders have long been known to be among the most elaborate animal communication behaviours. We now show that one species, Habronattus dossenus, also exhibits an unprecedented complexity of signalling behaviour in the vibratory (seismic) modality. We videotaped courtship behaviour and used laser vibrometry to record seismic signals and observed that each prominent visual signal is accompanied by a subsequent seismic component. Three broad categories of seismic signals were observed(`thumps', `scrapes' and `buzzes'). To further characterize these signals we used synchronous high-speed video and laser vibrometry and observed that only one seismic signal component was produced concurrently with visual signals. We examined the mechanisms by which seismic signals are produced through a series of signal ablation experiments. Preventing abdominal movements effectively`silenced' seismic signals but did not affect any visual component of courtship behaviour. Preventing direct abdominal contact with the cephalothorax, while still allowing abdominal movement, only silenced thump and scrape signals but not buzz signals. Therefore, although there is a precise temporal coordination of visual and seismic signals, this is not due to a common production mechanism. Seismic signals are produced independently of visual signals, and at least three independent mechanisms are used to produce individual seismic signal components.
Arsenic — a Review. Part II: Oxidation of Arsenic and its Removal in Water Treatment
Authors: Bissen Monique , Frimmel Fritz H.
Published: October 2003

In natural waters arsenic normally occurs in the oxidation states +III (arsenite) and +V (arsenate). The removal of As(III) is more difficult than the removal of As(V). Therefore, As(III) has to be oxidized to As(V) prior to its removal. The oxidation in the presence of air or pure oxygen is slow. The oxidation rate can be increased by ozone, chlorine, hypochlorite, chlorine dioxide, or H2O2. The oxidation of As(III) is also possible in the presence of manganese oxide coated sands or by advanced oxidation processes.

Arsenic can be removed from waters by coprecipitation with Fe(OH)3, MnO2 or during water softening. Fixed‐bed filters have successfully been applied for the removal of arsenic.The effectiveness of arsenic removal was tested in the presence of adsorbents such as FeOOH, activated alumina, ferruginous manganese ore, granular activated carbon, or natural zeolites. Other removal technologies are anion exchange, electrocoagulation, and membrane filtration by ultrafiltration, nanofiltration or reverse osmosis.
A view of our future: The case for redesigning rheumatology practice
Authors: Timothy Harrington J.
Published: October 2003

“At no time in the history of medicine has the growth in knowledge been so profound… As medical science and technology have advanced at a rapid pace, however, the health care delivery system has foundered in its ability to provide consistently high quality care for all Americans…The American health care delivery system is in need of fundamental change.” Committee on Quality Health Care in America, Institute of Medicine (1).
Microscopic polyangiitis and polyarteritis nodosa: How and when do they start?
Authors: Agard Christian , Mouthon Luc , Mahr Alfred , Guillevin Loïc
Published: October 2003

Objective

To describe initial clinical symptoms attributable to microscopic polyangiitis (MPA) or polyarteritis nodosa (PAN).

Methods

We retrospectively reviewed the medical files of 72 patients (mean followup 6.7 years) with biopsy‐proven MPA (n = 36) or PAN (n = 36).

Results

Initial manifestations were similar in both entities except for peripheral neuropathy (P = 0.02) and gastrointestinal tract involvement (P = 0.006), which were significantly more frequent in PAN, and general signs alone in MPA (8%; P = 0.02). The mean time to diagnosis was 9.8 ± 19.4 months; 35% of the patients died and 26% relapsed; significantly more MPA than PAN patients relapsed (P = 0.03). Time to diagnosis ≥90 days was associated with a trend toward more patients relapsing (P = 0.12), but not with an increased risk of mortality.

Conclusion

Initial symptoms of MPA and PAN are usually nonspecific and last for several months before the diagnosis is made. A longer time to diagnosis is associated with a tendency to a higher relapse rate.
The Effect of Ring Nitrogen Atoms on the Homolytic Reactivity of Phenolic Compounds: Understanding the Radical‐Scavenging Ability of 5‐Pyrimidinols
Authors: Valgimigli Luca , Brigati Giovanni , Pedulli Gian Franco , DiLabio Gino A. , Mastragostino Marina , Arbizzani Catia , Pratt Derek A.
Published: October 2003

Six substituted 5‐pyrimidinols were synthesized, and the thermochemistry and kinetics of their reactions with free radicals were studied and compared to those of equivalently substituted phenols. To assess their potential as hydrogen‐atom donors to free radicals, we measured their OH bond dissociation enthalpies (BDEs) using the radical equilibration electron paramagnetic resonance technique. This revealed that the OH BDEs in 5‐pyrimidinols are, on average, about 2.5 kcal mol−1 higher than those in equivalently substituted phenols. The results are in good agreement with theoretical predictions, and confirm that substituent effects on the OH BDE of 5‐pyrimidinol are essentially the same as those on the OH BDE in phenol. The kinetics of the reactions of these compounds with peroxyl radicals has been studied by their inhibition of the AIBN‐initiated autoxidation of styrene, and with alkyl and alkoxyl radicals by competition kinetics. Despite their larger OH BDEs, 5‐pyrimidinols appear to transfer their phenolic hydrogen‐atom to peroxyl radicals as quickly as equivalently substituted phenols, while their reactivity toward alkyl radicals far exceeds that of the corresponding phenols. We suggest that this rate enhancement, which is large in the case of alkyl radical reactions, small in the case of peroxyl radical reactions, and nonexistent in the case of alkoxyl radical reactions, is due to polar effects in the transition states of these atom‐transfer reactions. This hypothesis is supported by additional experimental and theoretical results. Despite this higher reactivity of 5‐pyrimidinols towards radicals compared to phenols, electrochemical measurements indicate that they are more stable to one‐electron oxidation than equivalently substituted phenols. For example, the 5‐pyrimidinol analogues of 2,4,6‐trimethylphenol and butylated hydroxytoluene (BHT) were found to have oxidation potentials approximately 400 mV higher than their phenolic counterparts, but reacted roughly one order of magnitude faster with alkyl radicals and at about the same rate with peroxyl radicals. The 5‐pyrimidinol structure should, therefore, serve as a useful template for the rational design of novel air‐stable radical scavengers and chain‐breaking antioxidants that are more effective than phenols.
Structure and Reactivity of Homoleptic Samarium(II) and Thulium(II) Phospholyl Complexes
Authors: Turcitu Daniela , Nief François , Ricard Louis
Published: October 2003

Potassium 2,5‐di‐tert‐butyl‐3,4‐dimethylphospholide K(dtp) (9) was synthesised in 45 % yield from commercially available starting materials by using zirconacyclopentadiene chemistry. Reaction of the K salt of this bulky anion and of the previously described potassium 2,5‐bis(trimethylsilyl)‐3,4‐dimethylphospholide K(dsp) (8) with SmI2 in diethyl ether afforded the homoleptic samarium(II) complexes 7 and 6, respectively, whose solid‐state structures, [{Sm(dtp)2}2] (7 a) and [{Sm(dsp)2}2] (6 a), are dimeric owing to coordination of the phosphorus lone pairs to samarium, as shown by X‐ray crystallography. Reaction of 8 with TmI2 in diethyl ether afforded [Tm(dsp)2(Et2O)], which could not be desolvated without decomposition. In contrast, the coordinated ether group of the solvate [Tm(dtp)2(Et2O)], obtained from 9 and TmI2, could easily be removed by evaporation of the solvent and extraction with pentane at room temperature, and the monomer [Tm(dtp)2] (5) could be isolated and was characterised by X‐ray crystallography. Presumably, steric crowding in 5 is too high for dimerisation to occur. Compound 5, the first TmII homoleptic sandwich complex, is remarkably stable at room temperature in solution and did not noticeably react with nitrogen, in sharp contrast with other thulium(II) species. As expected, 5, 6 and 7 all reacted with azobenzene to give the trivalent complexes [Tm(dtp)2(N2Ph2)] (13), [Sm(dsp)2(N2Ph2)], (14) and [Sm(dtp)2(N2Ph2)] (15), respectively; 13 and 14 were characterised by X‐ray crystallography. Complex 5 immediately reacted with triphenylphosphane sulfide at room temperature to give [{Tm(dtp)2}2(μ‐S)] (16), which was characterised by X‐ray crystallography, whereas samarium(II) complexes 6 and 7 did not noticeably react with Ph3PS over 24 h under the same conditions.
Self‐similar wavepackets for describing warm dense matter
Authors: Murillo M.S. , Timmermans E.
Published: October 2003

Using the time dependent variational principle, we develop a general formulation of single particle quantum dynamics within the assumption that the wavepacket's density remains self‐similar. We obtain the amplitudephase relationship from the continuity equation. We investigate the ground state properties of waves with Gaussian and exponential densities in hydrogenic and helium‐like systems. We show that the exponential wavepackets yield superior ground state energies ‐ an important advantage in describing warm dense matter (T < 50 eV) in which bound states form. Exponentials yield an improved ground state energy for molecular hydrogen, but with a bond length 13% short of the experimental value. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Results of lightning impulse tests for a 275‐kV full GIS substation
Authors: Hatano Ryosuke , Ishikawa Yasuhisa , Ueda Toshiaki , Nojima Kenichi , Motoyama Hideki
Published: October 2003

This paper describes the outline and results of the lightning impulse tests for a 275‐kV full GIS substation. The behavior of lightning surges is a very important factor for the rational design of substations and low‐voltage and control circuits inside the substations. For the above reason, we carried out lightning impulse tests for a new 275‐kV full GIS substation. In these tests, we measured voltage induced in low‐voltage and control circuits, transient characteristics of grounding grid, injected voltage and current waveforms, and so on.

By investigating these data, we confirmed the behavior of lightning surges inside the substation. We also compared simulated waveforms by EMTP analysis with the measured waveforms. The simulated results agreed well with the measured results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 46–58, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10230
Differential Pulse Polarography for a First‐Order EC Process and Its Diagnostic Parameters
Authors: Kim Myung‐Hoon , Yan Lei , Birke Ronald L. , Czae Myung‐Zoon
Published: October 2003

Theoretical expressions for differential pulse polarography (DPP) for a reversible electron transfer coupled with an irreversible follow‐up first‐order chemical reaction (ErCi) is derived approximately. The peaks as given by the current expressions are analyzed in terms of several parameters such as a ratio of anodic‐to‐cathodic peak‐currents (ipa/ipc), a separation of peak‐potentials (Epc−Epa), and a ratio of anodic‐to‐cathodic half‐peak‐widths (W1/2a/W1/2c) in order to characterize the ErCi process and distinguish it from other types of electrode processes. The anodic peak is found to be more susceptible to the post kinetics than the cathodic peak. The new parameter of W1/2a/W1/2c ratio is much more sensitive to the post kinetics than the peak separation (Epc−Epa). The peak current ratio (ipa/ipc) and the peak‐width ratio (W1/2a/W1/2c) have comparable sensitivities to the kinetics. Hence, W1/2a/W1/2c ratio is a better diagnostic parameters than (Epc−Epa) which has a poor sensitivity. This phenomenon is different from cyclic voltammetry (CV) in which Epc−Epa is as sensitive as ipa/ipc. The new criteria for EC with DPV is tested and successfully applied to several Co(III) complex systems, including coenzyme B12. The homogeneous rate constant (k) for the follow‐up step is estimated from the measurements of the experimental values of the parameters. The present treatment is valid quantitatively at lower values of k, yielding relatively larger errors for higher k values (k>10 s−1).
Rat liver transplantation for total vascular reconstruction, using a suture method
Authors: Inoue Seiichiro , Tahara Kazunori , Shimizu Hisashi , Yoshino Hiroyuki , Suzuki Chihiro , Kaneko Takashi , Hakamata Yoji , Takahashi Masafumi , Murakami Takashi , Kaneko Michio , Kobayashi Eiji
Published: October 2003

We developed a novel protocol for rat orthotopic liver transplantation (OLT), using a suture method to establish hepatic artery flow. After determining that early inferior vena cava (IVC) unclamping maintained better circulation compared with the portal vein (PV) using porto‐systemic shunted recipients, we developed a rat OLT model with total vascular reconstruction using a suture method. After connecting the suprahepatic IVC, the infrahepatic IVC was anastomosed, using a running suture method. IVC circulation was established immediately. The PV was anastomosed without intestinal congestion, using porto‐systemic shunted recipients. The aortic conduit, including the donor celiac and hepatic artery, was anastomosed to the recipient abdominal aorta end‐to‐side. Eight of 11 OLT cases (72.7%) survived indefinitely. Biliary connection was achieved using a one‐stent method. Three cases died 3–5 days postoperatively. Hepatic angiography showed good patency. The graft liver was histologically normal in long‐surviving rats. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:470–475 2003