bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro anti‐mycobacterial activities of three species of Cola plant extracts (Sterculiaceae)
Authors: Adeniyi B. A. , Groves M. J. , Gangadharam P. R. J.
Published: May 2004

Extracts obtained from three Nigerian Sterculiaceae plants: Cola accuminata, C. nitida and C. milleni were screened for anti‐mycobacterium properties using a slow growing Mycobacterium bovis ATCC 35738 (designated BCG Mexican and known to have some virulence in mouse and guinea pig) at 1000 µg/ml using the radiometric (BACTEC) method. The extracts were also tested against six fast growing ATCC strains of M. vaccae using the broth microdilution method.

The methanol extracts from both leaves, stem bark and root bark of Cola accuminata and from the leaves and stem bark of C. nitida and C. milleni were not active at the highest concentration of 1000 µg/ml. Only the methanol extract of root bark for both C. nitida and C . milleni were found to be potent against both M. bovis and strains of M. vaccae. The minimum inhibitory concentration (MIC) of C. nitida against M. bovis is 125 µg/ml while the MIC of C. milleni against M. bovis is 62.5 µg/ml after at least 6 days of inhibition with growth index (GI) units lesser than or equal to the change in GI units inoculated with a 1/100 of the BACTEC inoculum for a control vial.

The minimum inhibitory concentration of C. milleni against the six ATCC strain of M. vaccae ranged from 62.5 µg/ml to 250 µg/ml while for C. nitida ranged from 500 µg/ml to above1000 µg/ml. Evidently, C. milleni has the highest inhibitory activity against both M. bovis and strains of M. vaccae used. Rifampicin, the positive control used has strong activity against M. bovis at the tested concentration of 5 µg and 10 µg/ml and 4 to 8 µg/ml against the six strains of M. vaccae. Copyright © 2004 John Wiley & Sons, Ltd.
Patented antiinﬂammatory plant drug development from traditional medicine
Authors: Darshan S. , Doreswamy R.
Published: May 2004

Patents secured on antiinﬂammatory plant drugs derived from 38 plants are reviewed. An attempt has been made to compare the modern and traditional use of plant drugs and to establish the relevance of folk claims in developing modern drugs. The role of plant botanicals such as polysaccharides, terpenes, curcuminoids, alkaloids, etc. in alleviating inﬂammatory diseases including arthritis, rheumatism, acne skin allergy and ulcers is highlighted. Chemicals that alleviate swelling are derived from plants including grape, boswellia, turmeric, devil's claw and some essential oils such as clove, eucalyptus, rosemary, lavender, mint, myrrh, millefolia and pine have been patented and used as mixed formulations. Plants containing polysaccharides are the most potent in curing inﬂammatory diseases. Copyright © 2004 John Wiley & Sons, Ltd.
Accuracy Analysis of the Estimated Process Yield Based on Spk
Authors: Pearn W. L. , Chuang C. C.
Published: May 2004

Process yield has been the most basic and common criterion used in the manufacturing industry as a base for measuring process performance. Boyles considered a measurement formula called Spk, which establishes the relationship between the manufacturing specification and the actual process performance, providing an exact (rather than approximate) measure of process yield. Unfortunately, the sampling distribution and the associated statistical properties of Spk are analytically intractable. In this paper, we consider the natural estimator of the measure Spk. We investigate the accuracy of the natural estimator of Spk computationally, using a simulation technique to find the relative bias and the relative mean square error for some commonly used quality requirements. Extensive simulation results are provided and analyzed, which are useful to the engineers for factory applications in measuring process performance. Copyright © 2004 John Wiley & Sons, Ltd.
Automatic Petri Net Simulation Model Generation for a Continuous Flow Transfer Line with Unreliable Machines
Authors: Sörensen Kenneth , Janssens Gerrit K.
Published: May 2004

A production line is studied with several machines in series. The machines are separated with finite buffers. They can break down and have to be repaired. Production is assumed to be continuous, i.e. no individual products can be identified. Analytical models for the performance evaluation of such a system are scarce. Analytical results for the throughput can be obtained only under very restrictive assumptions. The performance study of longer transfer lines requires either approximation or simulation. A Petri net model is developed for an n‐machine $(n-1)$‐buffer system. The rules to design the Petri net transitions are given. The automatic generation of a discrete‐event simulation model from the Petri net model is explained. Finally, some potential applications of the Petri net are illustrated. These applications include the simulation of transfer lines with complex stochastic behaviour, the optimization of buffer size and allocation and the evaluation of approximation models for long transfer lines. Using the simulation model described in this paper, quality and reliability engineers can simulate the performance of a given continuous flow transfer line and evaluate the effect of performance‐increasing measures such as the insertion of extra buffer space or the use of more reliable machines. Copyright © 2004 John Wiley & Sons, Ltd.
Comparison of Methods to Estimate the Time‐to‐failure Distribution in Degradation Tests
Authors: de Oliveira Viviane Ribeiro Branco , Colosimo Enrico Antônio
Published: May 2004

Degradation tests are alternative approaches to lifetime tests and accelerated lifetime tests in reliability studies. Based on a degradation process of a product quality characteristic over time, degradation tests provide enough information to estimate the time‐to‐failure distribution. Some estimation methods, such as analytical, the numerical or the approximated, can be used to obtain the time‐to‐failure distribution. They are chosen according to the complexity of the degradation model used in the data analysis. An example of the application and analysis of degradation tests is presented in this paper to characterize the durability of a product and compare the various estimation methods of the time‐to‐failure distribution. The example refers to a degradation process related to an automobile's tyre, and was carried out to estimate its average distance covered and some percentiles of interest. Copyright © 2004 John Wiley & Sons, Ltd.
Adaptive tracking control of flexible‐joint manipulators without overparametrization
Authors: Kim Min S. , Lee Jin S.
Published: May 2004

In this paper, an adaptive controller is designed for rigid‐link flexible‐joint robot manipulators based on link and actuator position measurements only. It is based on the adaptive integrator backstepping method and the link and actuator velocity filters are used to estimate the unknown velocity terms. Moreover, the proposed controller exploits the estimate of the joint stiffness matrix inverse to overcome the overparametrization problem, which has been a significant drawback in adaptive partial state feedback controllers. It achieves asymptotic tracking of link positions while keeping all states and signals bounded. The tracking capability of the presented method is shown through simulation results of one‐ and two‐link flexible joint manipulators. © 2004 Wiley Periodicals, Inc.
Dynamic process programming for a robotic manipulator based on hopfield NN monotonous optimization searching
Authors: Yu Zhongwei , Chen Huitang , Woo Peng‐Yung
Published: May 2004

A new approach to programming the optimal dynamic process for an n‐joint
rigid robotic manipulator with the use of the monotonous optimization searching
ability of a Hopfield NN is presented. By combining robotic dynamics, this
paper designs a programmed controller, which satisfies the aforementioned
dynamic process. The convergence of the programmed controller is investigated.
Simulations and experiments demonstrate the effectiveness of the scheme described. ©
2004 Wiley Periodicals, Inc.
A new space and time sensor fusion method for mobile robot navigation
Authors: Jin TaeSeok , Lee JangMyung , Tso S. K.
Published: May 2004

To fully utilize the information from the sensors of mobile robot, this paper proposes a new sensor‐fusion technique where the sample data set obtained at a previous instant is properly transformed and fused with the current data sets to produce a reliable estimate for navigation control. Exploration of an unknown environment is an important task for the new generation of mobile service robots. The mobile robots may navigate by means of a number of monitoring systems such as the sonar‐sensing system or the visual‐sensing system. Notice that in the conventional fusion schemes, the measurement is dependent on the current data sets only. Therefore, more sensors are required to measure a given physical parameter or to improve the reliability of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequences of the data sets are stored and utilized for the purpose. The basic principle is illustrated by examples and the effectiveness is proved through simulations and experiments. The newly proposed STSF (space and time sensor fusion) scheme is applied to the navigation of a mobile robot in an environment using landmarks, and the experimental results demonstrate the effective performance of the system. © 2004 Wiley Periodicals, Inc.
The distribution of the size of the ancestor‐tree and of the induced spanning subtree for random trees
Authors: Panholzer Alois
Published: May 2004

We consider two tree statistics that extend in a natural way the parameters depth of a node resp. distance between two nodes. The ancestor‐tree of p given nodes in a rooted tree T is the subtree of T, spanned by the root and these p nodes and generalizes the depth (ancestor‐tree of a single node), whereas the spanning subtree induced by p given nodes in a tree T generalizes the distance (induced spanning subtree of two nodes). We study the random variables size of the ancestor‐tree resp. spanning subtree size for two tree families, the simply generated trees and the recursive trees. We will assume here the random tree model and also that all () possibilities of selecting p nodes in a tree of size n are equally likely. For random simply generated trees we can then characterize for a fixed number p of chosen nodes the limiting distribution of both parameters as generalized Gamma distributions, where we prove the convergence of the moments too. For some specific simply generated tree families we can give exact formulæ for the first moments. In the instance of random recursive trees, we will show that the considered parameters are asymptotically normally distributed, where we can give also exact formulæ for the expectation and the variance. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
Is the degree of fetal hepatosplenomegaly with transient abnormal myelopoiesis closely related to the postnatal severity of hematological abnormalities in Down syndrome?
Authors: Ogawa M. , Hosoya N. , Sato A. , Tanaka T.
Published: May 2004

We present three cases of transient abnormal myelopoiesis associated with trisomy 21 in which hepatomegaly was apparent during the fetal period. In the first case, the fetal hepatosplenomegaly was severe, multiple organ failure occurred in the neonatal period and death ensued at 4 weeks of age. In the second case, the hepatomegaly was moderate, and with conservative treatment in the neonatal period the outcome was good. In the third case, hepatomegaly was mild and improved spontaneously, and the hematological abnormalities required only conservative treatment in the neonatal period. Our experience raises the question of whether fetal hepatosplenomegaly is a predictor of transient myeloproliferative disorder with trisomy 21 and whether the degree of fetal hepatomegaly is a marker for the neonatal severity of hematological abnormalities. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Smoothing effects of distributed wind turbines. Part 1. Coherence and smoothing effects at a wind farm
Authors: Nanahara Toshiya , Asari Masahiro , Sato Takamitsu , Yamaguchi Koji , Shibata Masaaki , Maejima Tsutomu
Published: May 2004

Recently there has been a marked increase in wind power generation. From a power system point of view, because a wind turbine is an intermittent generator with large output fluctuation, any increase in the number of wind turbines gives rise to concerns about the adverse effects of wind turbines on power quality. The smoothing effects of wind turbine output fluctuation are of great importance in assessing the impacts of a large number of wind turbines. This article examines smoothing effects at a wind farm. First it presents a summary of wind measurements taken at two locations with six masts over a period of 1 year on both flat and complex terrain. Then the spatial coherence of wind speed is analysed, paying special attention to its dependence on the distance between observation points, wind direction, wind velocity and fluctuation frequency. Approximation equations for coherence of frequency and distance are obtained by applying Davenport's expression to the observed data. Second, coherence between turbine output at a wind farm is investigated; the results indicate that coherence for wind speed and turbine output shows a considerable resemblance. The article also examines smoothing effects at a wind farm using power spectral density through a theoretical approach. The study proves that smoothing effects can be approximated with a lowpass filter and that the effects at a wind farm should not be taken into account for periods of more than 10 min in case of assessing them on the safe side. Copyright © 2004 John Wiley & Sons, Ltd.
Grid impacts of wind power: a summary of recent studies in the United States
Authors: Parsons Brian , Milligan Michael , Zavadil Bob , Brooks Daniel , Kirby Brendan , Dragoon Ken , Caldwell Jim
Published: May 2004

Several detailed technical investigations of grid ancillary service impacts of wind power plants in the United States have recently been performed. These studies were applied to Xcel Energy (in Minnesota) and PacifiCorp and the Bonneville Power Administration (both in the northwestern United States). Although the approaches vary, three utility time frames appear to be most at issue: regulation, load following and unit commitment. This article describes and compares the analytic frameworks from recent analysis and discusses the implications and cost estimates of wind integration. The findings of these studies indicate that relatively large‐scale wind generation will have an impact on power system operation and costs, but these impacts and costs are relatively low at penetration rates that are expected over the next several years. Published in 2004 by John Wiley & Sons, Ltd.
Experimental results of the variable speed, direct drive multipole synchronous wind turbine TWT1650
Authors: Torres Eduardo , Garcia‐Sanz Mario
Published: May 2004

This article presents details of the new variable speed multipole large wind turbine TWT1650 designed by the M. Torres group and summarizes some experimental results of the control system. After several years of multidisciplinary research the first prototype TWT1650 began to work at Cabanillas Wind Farm (Spain) in August 2001. Since then a large number of operational data have been collected and used to improve the behaviour of the machine. The design and controller tuning have been accomplished using advanced QFT (quantitative feedback theory) robust control strategies and have been optimized based on analysis of that information. This article introduces the main advantages of the multipole system and shows and evaluates some of the most representative experimental results under extreme wind conditions. Copyright © 2004 John Wiley & Sons, Ltd.
On‐line assessment of prediction risk for wind power production forecasts
Authors: Pinson P. , Kariniotakis G.
Published: May 2004

The article introduces a new methodology for assessing on‐line the prediction risk of short‐term wind power forecasts. The first stage of this methodology consists in computing confidence intervals with a confidence level defined by the end‐user. The resampling approach is used, which, in contrast to existing methods for wind forecasting, does not need to make a restrictive hypothesis on the distribution of the errors. To account for the non‐linearity of the power curve and the cut‐off effect, the errors are classified using appropriate fuzzy sets. The confidence intervals are then fine‐tuned to reduce their width in the case of stable weather conditions. For this purpose an appropriate index, called the ‘meteo‐risk index’ (MRI), is defined reflecting the spread of the available numerical weather predictions. A linear relation between that index and the resulting prediction error is shown. The second part of the methodology is to use the MRI itself as a preventive on‐line tool to derive signals for the operator on the meteorological risk, i.e. the probabilities of the occurrence of high prediction errors depending on the weather stability. Evaluation results of this methodology over a 1 year period on the case study of Ireland are given, where the output of several wind farms is predicted using a dynamic fuzzy neural network‐based model. The proposed methodology is generic and can be applied to all kinds of wind power prediction models. Copyright © 2004 John Wiley & Sons, Ltd.
Aeroelastic stability analysis of wind turbines using an eigenvalue approach
Authors: Hansen M. H.
Published: May 2004

A design tool for performing aeroelastic stability analysis of wind turbines is presented in this paper. The method behind this tool is described in a general form, as independent of the particular aeroelastic modelling as possible. Here, the structure is modelled by a Finite beam Element Method, and the aerodynamic loads are modelled by the Blade Element Momentum method coupled with a Beddoes‐Leishman type dynamic stall model in a state‐space formulation. The linearization of the equations of motion is performed about a steady‐state equilibrium, where the deterministic forcing of the turbine is neglected. To eliminate the periodic coefficients and avoid using the Floquet Theory, the multi‐blade transformation is utilized. From the corresponding eigenvalue problem, the eigenvalues and eigenvectors can be computed at any operation condition to give the aeroelastic modal properties: Natural frequencies, damping and mode shapes. An example shows a good agreement between predicted and measured aeroelastic damping of a stall‐regulated 600 kW turbine. Copyright © 2004 John Wiley & Sons, Ltd.
Development of the Risø wind turbine airfoils
Authors: Fuglsang Peter , Bak Christian
Published: May 2004

This paper presents the wind turbine airfoil development at Risø. The design method is described together with our target characteristics for wind turbine airfoils. The use of the CFD code Ellipsys2D for prediction of final target characteristics is described together with the VELUX wind tunnel testing setup. Three airfoil families were developed; Risø‐A1, Risø‐P and Risø‐B1. The Risø‐A1 airfoil family was developed for rotors of 600 kW and larger. Wind tunnel testing and field testing showed that this airfoil family is well suited for stall and active stall control. However, sensitivity to roughness was higher than expected. Field tests of a 600 kW active stall wind turbine showed an estimated reduction in blade fatigue loading of up to 15% at the same annual energy yield and at the same time reduced blade weight and blade solidity. The Risø‐P airfoils were developed to replace the Risø‐A1 airfoils for use on pitch controlled wind turbines. Improved design objectives should reduce the sensitivity to roughness, but measurements are not yet available. The Risø‐B1 airfoil family was developed for variable speed operation with pitch control of large megawatt sized rotors. Wind tunnel testing verified the high maximum lift for these airfoils, and the airfoils were found to be very insensitive to leading edge roughness. Performance with vortex generators and Gurney flaps in combination was found to be attractive for the blade root part. Field testing of a 1·5 MW rotor is in progress. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and Raman Spectroscopy of Nanoparticles of Crystalline and X‐ray Amorphous Germanium within Mesoporous SiO2
Authors: Schlecht Sabine , Yosef Maekele , Fröba Michael
Published: May 2004

Mesoporous hexagonally ordered SiO2 (SBA‐15) with a pore diameter of 7 nm was used as a host matrix for nanoparticles of amorphous and crystalline germanium. Raman spectra were recorded for these germanium nanoparticles and for bulk amorphous and crystalline germanium powder. The band shifts and line shapes of the Raman bands for the optical phonon at ∼300 cm—1 were analyzed and compared to the theoretical predictions derived from the phonon confinement model. In addition, the microstructure of amorphous hydrogenated germanium could be further elucidated by Raman spectroscopy and by thermal analysis.
On the Crystal Structure of K2Cu5Cl8(OH)4·2H2O
Authors: Kahlenberg Volker
Published: May 2004

Single crystals of K2Cu5Cl8(OH)4·2H2O were grown using hydrothermal techniques. The compound is monoclinic with a = 11.6424(11), b = 6.5639(4), c = 11.7710(10)Å, β = 91.09(1)°, V = 899.4(2)Å3, space group P21/c, Z = 2. The crystal structure was determined using single crystal X‐ray diffraction data and refined to a residual of R(|F|) = 0.025 for 1208 independent observed reflections with I > 2σ(I). Two out of three crystallographically independent Cu atoms are coordinated to four near hydroxyl groups or chlorine atoms and two more distant Cl atoms, giving an octahedrally Jahn‐Teller distorted (4+2)‐configuration. For the remaining third copper cation a square‐planar coordination can be found. Edge‐sharing of the octahedra results in the formation of kagome‐type sheets parallel to (100). The octahedral layers are decorated on both sides by planar [Cu(OH)2Cl2]‐units around the third Cu atom. The K atoms are located between adjacent sheets and are surrounded by six Cl atoms as well as two water molecules. The coordination polyhedra about the K‐atoms can be described as distorted bicapped trigonal prisms. Additional linkage is provided by intra‐ as well as inter‐layer hydrogen bonds (O—H···Cl, O—H···O).
Ramifications of metastability in bit variables explored via Simpson’s 4-slot mechanism
Authors: Paynter S. E. , Henderson N. , Armstrong J. M.
Published: May 2004

Protocol descriptions often fail to take metastability into account. Metastability, however, can undermine protocols which depend on shared bits. In this paper a series of increasingly realistic models of bits are developed in CSP to explore the implications of metastability for Simpson’s 4-slot asynchronous communication mechanism. It is shown that the 4-slot mechanism with realistic bit models preserves data-coherence, freshness, and sequencing, and is Lamport-atomic. We demonstrate that metastability can undermine the correctness of protocols demonstrated correct on the assumption that bits are Lamport-safe; furthermore, realistic bit models can demonstrate that protocols are correct which Lamport-safe bit models would suggest were incorrect or impossible.
Dispersal distance of corn pollen under fluctuating diffusion coefficient
Authors: Yamamura Kohji
Published: May 2004

I develop a mechanistic model for pollen dispersal by a generalization of the Brownian motion model. This model provides an explanation as to why the distribution of the dispersal distance is leptokurtic in most organisms. The pollen is assumed to move in a period betweenτandτ+Δτto the circumference of a circle of radius Δrτthat has a center at the current position. The angle of movement is chosen at random. Unlike the conventional Brownian motion model, the step length, Δrτ, fluctuates in a stochastic manner, obeying a generalized gamma distribution. The convection flow, i.e., the directional movement of pollen, is also considered. I show that this model is identical to the diffusion model where the dispersal duration weighted by the diffusion coefficient obeys a gamma distribution. Hence, the model is called the gamma model. The solution is given in an explicit form. The model is fitted to six data sets obtained from the literature by maximizing the quasi‐likelihood. Another model (the inverse gamma model), which is not a mechanistic model but a phenomenological model, is also fitted to the data to evaluate the validity of the gamma model.
Abortion laws and policies: challenges and opportunities
Authors: Cook Rebecca J.
Published: May 2004

An analysis of abortion law reform in all regions of the world in the past 20 years shows that countries have turned from a concentration upon criminality to a concern with women's health and family well‐being. Pragmatic approaches to achieve liberalization of abortion laws are described. Where legal reform is unlikely, specification of professional medical standards, clarification of laws and the scope of allowable action, as well as supportive statements by government officials, can facilitate services and may ultimately have a positive influence on legal reform.
Control of pain for women undergoing abortion
Authors: Stubblefield Phillip G.
Published: May 2004

To reduce the anxiety and pain experienced by women undergoing abortion, pre‐abortion psychological counseling should be given the first priority. Additional techniques for reducing pain are described, including the use of local anesthetic, sedatives, analgesics, and systemic anesthetic agents. Recommendations for practice include an improved technique for paracervical block, modified abortion technique to reduce painful stimulus, and safe use of low dose intravenous sedatives. General anesthesia should be avoided to improve abortion safety.
Risk factors for pain in children with severe cognitive impairments
Authors: Breau Lynn M , Camfield Carol S , Mc Grath Patrick J , Finley G Allen
Published: May 2004

Diagnosing cause of pain in children with severe cognitive impairments is difficult due to their problems with communication. Identification of risk factors for specific pain etiologies might help professionals in this task. The aim of this study was to determine whether child‐related characteristics increase risk for specific types of pain. Participants were the caregivers of 41 females and 53 males with moderate to profound mental retardation,* who were aged 3 to 18 years 8 months (mean 10:1, SD 4:4) but who communicated at the level of a typical child of 13.8 months (SD 10 months): 44 of the children had cerebral palsy (CP) and 59 a seizure disorder. Caregivers reported the cause of children's episodes of pain for four 1‐week periods over 1 year. Logistic regression analyses were used to predict occurrence of specific types of pain using children's demographic, medical, and physical characteristics. Children had 406 episodes of pain due to accident, gastrointestinal conditions, musculoskeletal problems, infection, recurrent conditions, and common childhood causes. Results indicated that a unique set of risk factors predicted each pain type in this sample. Significant risk factors for pain included: lack of visual impairment and leg impairment (accidental pain); seizures, leg impairment, and greater number of medications (non‐accidental pain); being male and tube fed (musculoskeletal pain); age <7 years, absence of CP, visual impairment, and less frequent medical monitoring (infection pain); being female and with arm impairment (gastrointestinal pain); and being tube fed and taking fewer medications (common childhood pains). In most cases, models were more specific than sensitive, indicating that the significant predictors are more useful for eliminating potential pain causes. These results suggest that population risk factors may be helpful in structuring diagnostic investigations for individual children with severe cognitive impairments.
Relationship between motor proficiency, attention, impulse, and activity in children with ADHD
Authors: Tseng Mei Hui , Henderson Anne , Chow Susanna M K , Yao Grace
Published: May 2004

The aim of this study was to investigate the relationship between motor performance, attention deficit, impulsiveness, and hyperactivity in children with attention‐deficit–hyperactivity disorder (ADHD). Participants were 42 school‐aged children with ADHD (36 males, 6 females; mean age 8 years 2 months, SD1 year 2 months; range 6 years to 11 years), and 42 age‐ and sex‐matched children without ADHD (mean age 8 years 3 months, SD 1 year 1 month; range 6 years to 11 years). Motor abilities were assessed with the Bruininks‐Oseretsky Test of Motor Proficiency. Attention and impulse control were measured with the Gordon Diagnostic System, and assessment of activity level was based on two Activity Level Rating Scales that were completed by parents and teachers. Analysis by t‐test revealed a significant difference between children with and without ADHD in fine and gross motor skills, impulse control, and attention. Stepwise regression indicated that attention, impulse control, and parent ratings of activity level were the three best predictors of gross motor skills for children with ADHD, accounting for 55.9% of the variance. Attention and impulse control were the two best predictors of fine motor skills, accounting for 45.7% of the variance. Attention and impulse control were consistently found to be important predictors of both fine and gross motor skills in children with ADHD. However, the fact that activity level was a predictor for gross motor proficiency but not for fine motor tasks suggests that different behavioral processes are involved in fine and gross motor performance to different extents.
Validation of a parent report measure of cognitive development in very preterm infants
Authors: Johnson Samantha , Marlow Neil , Wolke Dieter , Davidson Leslie , Marston Louise , O'Hare Ann , Peacock Janet , Schulte Jane
Published: May 2004

Parental report may provide an inexpensive alternative to standardized assessments of children's development. We have adapted and validated a parental questionnaire on cognitive development for use with very preterm infants. Sixty‐four 2‐year‐olds (28 males, 36 females) born less than 30 weeks' gestation (median 28.5 weeks, range 23 to 31 weeks), median birth weight 980g (range 500 to 1905g) were assessed using the Mental Development Index (MDI) of the Bayley Scales of Infant Development‐II and the parental questionnaire. Significant correlations between parent report and MDI scores (r=0.54−0.68, p<0.001) indicated good concurrent validity. Diagnostic use of the parent report for predicting an MDI score of less than 70 was assessed by using receiver operating characteristic (ROC) curves. The optimal cut off produced equal sensitivity and specificity (81%), indicating good discriminatory power in diagnosing developmental delay. Test‐retest reliability was demonstrated and accuracy of parent reporting was not affected by sociodemographic factors. Our questionnaire provides a valid outcome measure for use in randomized trials or large population surveys.
Effects of supramalleolar orthoses on postural stability in children with Down syndrome
Authors: Martin Kathy
Published: May 2004

This study explored the effects of a flexible supramalleolar orthosis (SMO), indicated to decrease pronation associated with hypotonia, on postural stability in children with Down syndrome. Seventeen children with Down syndrome (nine males, eight females; mean age 5 years 10 months, SD 17.2 months; range 3 years 6 months to 8 years) were tested three times in a 10‐week period (weeks 1,3, and 10) using the Standing and the Walking, Running, and Jumping dimensions of the Gross Motor Function Measure (GMFM), and the Balance subtest of the Bruininks‐Oseretsky Test of Motor Proficiency (BOTMP). Range of motion measurements were used to explore the influence of joint laxity. Significant improvement was found with SMOs compared with shoes only in the Standing dimension (p=0.001) and the Walking, Running, and Jumping dimension (p=0.0001) of the GMFM, both at the time of fitting (week 3) and after 7 weeks of wearing SMOs (week 10). For the BOTMP Balance subtest, significant improvement (p=0.027) was seen only at the end of the 7‐week study period. Amount of joint laxity did not influence response to orthotic intervention. This study showed that young children with Down syndrome showed immediate and longer‐term (after 7 weeks of use) improvement in postural stability with the use of flexible SMOs.
Remodeling of the proximal femur after varus osteotomy in children with cerebral palsy
Authors: Mazur John M , Danko Aileen M , Standard Shawn C , Loveless Eric A , Cummings R Jay
Published: May 2004

The purpose of this study was to determine and measure the factors that affect the remodeling of the proximal femur after varus osteotomy in children with spastic cerebral palsy (CP). Seventy‐five varus proximal osteotomies were performed on 44 children (26 females, 18 males) for hip dysplasia. Thirty‐nine patients had spastic CP and five had spastic diplegia; 35 patients used a wheelchair for mobility and nine could walk. Mean age at time of surgery was 8 years (SD 4 years), range 2 years 6 months to 15 years. Preoperative, immediate postoperative, and follow‐up (0 to 6 months, 6 months to <1 year, 1 year to <2 years, 2 years to <4 years, 4 years to <6 years, and 6 years to <8 years) radiographs were reviewed. Neck‐shaft angles were measured. Correlations to examine the relationship between age at time of surgery and ambulatory status with postoperative changes in neck‐shaft angles were reviewed. Remodeling of the proximal femur does occur after varus osteotomy as long as the physes of the proximal femur show growth potential. Remodeling was quite variable between patients: children younger than 4 years old at the time of surgery remodeled more than children who were older than 4 years. Ambulatory status has little effect on the magnitude of remodeling. This study reinforces the need to follow these patients with periodic hip radiographs until completion of growth.
Secondary impairments in young adults with spina bifida
Authors: Verhoef M , Barf HA , Post M W M , van Asbeck F W A , Gooskens R H J M , Prevo A J H
Published: May 2004

The aim of this study was to examine the prevalence of secondary impairments in young adults with spina bifida and to relate the prevalence to the type of spina bifida and the level of lesion. This cross‐sectional study is part of the ASPINE (Adolescents with Spina Bifida in the Netherlands) study. Data were collected on medical history, hydrocephalus (shunt: yes/no), neurological level of lesion (International Standards for Neurological and Functional Classification of Spinal Cord Injury), visual acuity (Landolt rings), spasticity (Modified Ash worth Scale), contractures (range of motion), scoliosis (deviation from perpendicular), ambulation (Hoffer criteria), pressure sores and blood pressure (physical examination), epilepsy, pain, incontinence and sexuality (questionnaire), and cognitive functioning (Raven Standard Progressive Matrices). In total, 179 patients with spina bifida participated (41% male, age range 16 to 25 years, mean 20 years 9 months, SD 2 years 11 months). These were 37 patients with spina bifida occulta, 119 patients with spina bifida aperta and hydrocephalus (AHC+) and 23 patients with spina bifida aperta without hydrocephalus (AHC−). Of our patient group, 73 had a high‐level lesion (L2 and above), 68 a mid‐level lesion (L3 to L5), and 38 a low‐level lesion (S1 and below). Both subdivisions were strongly related with patients with higher lesions more often having hydrocephalus. Most secondary impairments were found for patients with AHC+, and patients with AHC− were mostly comparable to patients with spina bifida occulta. According to level of lesion, most medical problems were found in the high‐level lesion group. However, all subgroups suffered from health problems.
Congenital ocular motor apraxia associated with idiopathic generalized epilepsy in monozygotic twins
Authors: Gonzalez‐Martin J A , Kaye L C , Brown M , Ellis I , Appelton R , Kaye S B
Published: May 2004

Identical female twins (age 11 years) with congenital ocular motor apraxia and generalized idiopathic epilepsy are reported. Their presenting symptoms were a long history of abnormal head and eye movements. One twin developed partial sensory seizures. The patients underwent 16‐channel EEG, electro‐oculographic recordings, MRI of the brain, and genetic and metabolic investigations. EEG findings were consistent with idiopathic generalized epilepsy. Electro‐oculographic recordings of the saccades confirmed an inability to elicit horizontal saccades without preceding head movement; saccades to the left were better than saccades to the right. MR scans for one twin showed normal findings, however, for the twin who had meningitis they revealed asymmetry between the right and left temporal lobes but no specific abnormality. DNA analysis using a series of autosomal polymorphic markers confirmed the monozygocity of the twins. White blood cell enzyme analysis excluded Sandhoff disease, Tay–Sachs disease, GM1 gangliosidosis, metacromatic leucodystrophy, Gaucher disease, Niemann‐Pick disease (A and B), and Krabbe leucodystrophy. Albumin and immunoglobulin (IgA, IgG, and IgM) levels were normal. It is concluded that autosomal recessive inheritance seems the most likely explanation here, as recent studies have found insertion and missense mutations of the aprataxin gene which have been related to an early onset form of ataxia with ocular motor apraxia and hypoalbuminaemia.
OPERATOR-VALUED FOURIER MULTIPLIERS ON PERIODIC BESOV SPACES AND APPLICATIONS
Authors: Arendt Wolfgang , Bu Shangquan
Published: May 2004

Let $1\leq p,q\leq\infty$, $s\in\mathbb{R}$ and let $X$ be a Banach space. We show that the analogue of Marcinkiewicz’s Fourier multiplier theorem on $L^p(\mathbb{T})$ holds for the Besov space $B_{p,q}^s(\mathbb{T};X)$ if and only if $1\ltp\lt\infty$ and $X$ is a UMD-space. Introducing stronger conditions we obtain a periodic Fourier multiplier theorem which is valid without restriction on the indices or the space (which is analogous to Amann’s result (Math. Nachr.186 (1997), 5–56) on the real line). It is used to characterize maximal regularity of periodic Cauchy problems.

AMS 2000 Mathematics subject classification: Primary 47D06; 42A45
GENERATORS FOR $\mathcal{H}$-INVARIANT PRIME IDEALS IN $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$
Authors: Launois Stéphane
Published: May 2004

It is known that, for generic $q$, the $\mathcal{H}$-invariant prime ideals in $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$ are generated by quantum minors (see S. Launois, Les idéaux premiers invariants de $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$, J. Alg., in press). In this paper, $m$ and $p$ being given, we construct an algorithm which computes a generating set of quantum minors for each $\mathcal{H}$-invariant prime ideal in $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$. We also describe, in the general case, an explicit generating set of quantum minors for some particular $\mathcal{H}$-invariant prime ideals in $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$. In particular, if $(Y_{i,\alpha})_{(i,\alpha)\in[[1,m]]\times[[1,p]]}$ denotes the matrix of the canonical generators of $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$, we prove that, if $u\geq3$, the ideal in $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$ generated by $Y_{1,p}$ and the $u\times u$ quantum minors is prime. This result allows Lenagan and Rigal to show that the quantum determinantal factor rings of $O_{q}(\mathcal{M}_{m,p}(\mathbb{C}))$ are maximal orders (see T. H. Lenagan and L. Rigal, Proc. Edinb. Math. Soc.46 (2003), 513–529).

AMS 2000 Mathematics subject classification: Primary 16P40. Secondary 16W35; 20G42
ON A THEOREM OF A. A. GOL’DBERG
Authors: Fenton P. C.
Published: May 2004

It is shown that a condition on the order of a meromorphic function in a result of A. A. Gol’dberg cannot be relaxed.

AMS 2000 Mathematics subject classification: Primary 30D35
EXISTENCE OF POSITIVE SOLUTIONS FOR BOUNDARY-VALUE PROBLEMS WITH SINGULARITIES IN PHASE VARIABLES
Authors: Agarwal Ravi P. , O’Regan Donal , Staněk Svatoslav
Published: May 2004

The singular boundary-value problem $(g(x'))'=\mu f(t,x,x')$, $x'(0)=0$, $x(T)=b>0$ is considered. Here $\mu$ is the parameter and $f(t,x,y)$, which satisfies local Carathéodory conditions on $[0,T]\times(\mathbb{R}\setminus\{b\})\times(\mathbb{R}\setminus\{0\})$, may be singular at the values $x=b$ and $y=0$ of the phase variables $x$ and $y$, respectively. Conditions guaranteeing the existence of a positive solution to the above problem for suitable positive values of $\mu$ are given. The proofs are based on regularization and sequential techniques and use the topological transversality theorem.

AMS 2000 Mathematics subject classification: Primary 34B16; 34B18
PROPAGATION OF SMALLNESS FOR SOLUTIONS OF GENERALIZED CAUCHY–RIEMANN SYSTEMS
Authors: Malinnikova E.
Published: May 2004

Let $u$ be a solution of a generalized Cauchy–Riemann system in $\mathbb{R}^n$. Suppose that $|u|\le1$ in the unit ball and $|u|\le\varepsilon$ on some closed set $E$. Classical results say that if $E$ is a set of positive Lebesgue measure, then $|u|\le C\varepsilon^\alpha$ on any compact subset of the unit ball. In the present work the same estimate is proved provided that $E$ is a subset of a hyperplane and the (capacitary) dimension of $E$ is greater than $n-2$. The proof gives control of constants $C$ and $\alpha$.

AMS 2000 Mathematics subject classification: Primary 31B35. Secondary 35B35; 35J45
SYSTEMS OF INTEGRAL EQUATIONS WITH WEIGHTED DIFFERENCE KERNELS
Authors: Porter D. , Biggs N. R. T.
Published: May 2004

Explicit expressions are derived for the inverses of operators of a particular class that includes the operator corresponding to a system of coupled integral equations having weighted difference kernels. The inverses are expressed in terms of a finite number of functions and a systematic way of generating different sets of these functions is devised. The theory generalizes those previously derived for a single integral equation and an integral-equation system with pure difference kernels. The connection is made between the finite generation of inverses and embedding.

AMS 2000 Mathematics subject classification: Primary 45A05
ON SUBFIELDS OF A FIELD GENERATED BY TWO CONJUGATE ALGEBRAIC NUMBERS
Authors: Drungilas Paulius , Dubickas Artūras
Published: May 2004

Let $k$ be a field, and let $\alpha$ and $\alpha'$ be two algebraic numbers conjugate over $k$. We prove a result which implies that if $L\subset k(\alpha,\alpha')$ is an abelian or Hamiltonian extension of $k$, then $[L:k]\leq[k(\alpha):k]$. This is related to a certain question concerning the degree of an algebraic number and the degree of a quotient of its two conjugates provided that the quotient is a root of unity, which was raised (and answered) earlier by Cantor. Moreover, we introduce a new notion of the non-torsion power of an algebraic number and prove that a monic polynomial in $X$—irreducible over a real field and having $m$ roots of equal modulus, at least one of which is real—is a polynomial in $X^m$.

AMS 2000 Mathematics subject classification: Primary 11R04; 11R20; 11R32; 12F10
A POLYNOMIAL MODEL FOR THE DOUBLE-LOOP SPACE OF AN EVEN SPHERE
Authors: Kamiyama Yasuhiko
Published: May 2004

It is well known that $\varOmega^2S^{2n+1}$ is approximated by $\textrm{Rat}_{k}(\mathbb{C}P^{n})$, the space of based holomorphic maps of degree $k$ from $S^2$ to $\mathbb{C}P^{n}$. In this paper we construct a space $G_{k}^{n}$ which is an analogue of $\textrm{Rat}_{k}(\mathbb{C}P^{n})$, and prove that under the natural map $j_k:G_{k}^{n}\to\varOmega^2S^{2n}$, $G_{k}^{n}$ approximates $\varOmega^2S^{2n}$.

AMS 2000 Mathematics subject classification: Primary 55P35
SHARP HEAT-KERNEL ESTIMATES FOR HIGHER-ORDER OPERATORS WITH SINGULAR COEFFICIENTS
Authors: Barbatis Gerassimos
Published: May 2004

We obtain heat-kernel estimates for higher-order operators with measurable coefficients that can be singular or degenerate. Precise constants are given, which are sharp for small times.

AMS 2000 Mathematics subject classification: Primary 35K30; 47D06. Secondary 35K25; 35K35
The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis
Authors: Silver Scott C. , Ostro Linde E. T. , Marsh Laura K. , Maffei Leonardo , Noss Andrew J. , Kelly Marcella J. , Wallace Robert B. , Gómez Humberto , Ayala Guido
Published: May 2004

Across their range jaguars Panthera onca are important conservation icons for several reasons: their important role in ecosystems as top carnivores, their cultural and economic value, and their potential conflicts with livestock. However, jaguars have historically been difficult to monitor. This paper outlines the first application of a systematic camera trapping methodology for abundance estimation of jaguars. The methodology was initially developed to estimate tiger abundance in India. We used a grid of camera traps deployed for 2 months, identified individual animals from their pelage patterns, and estimated population abundance using capture-recapture statistical models. We applied this methodology in a total of five study sites in the Mayan rainforest of Belize, the Chaco dry forest of Bolivia, and the Amazonian rainforest of Bolivia. Densities were 2.4–8.8 adult individuals per 100 km2, based on 7–11 observed animals, 16–37 combined ‘captures’ and ‘recaptures’, 486–2,280 trap nights, and sample areas of 107–458 km2. The sampling technique will be used to continue long-term monitoring of jaguar populations at the same sites, to compare with further sites, and to develop population models. This method is currently the only systematic population survey technique for jaguars, and has the potential to be applied to other species with individually recognizable markings.
An experimental study of passive dynamic walking
Authors: Wu Q. , Sabet N.
Published: May 2004

A two-straight-legged walking mechanism with flat feet is designed and built to study the passive dynamic gait. It is shown that the mechanism having flat feet can exhibit passive dynamic walking as those with curved feet, but the walking efficiency is significantly lower. It is also shown that the balancing mass and its orientation are effective for controlling side-to-side rocking and yaw, which have significant effects on steady walking. The effects of various parameters on the gait patterns are also studied. lt is shown
that changes in the ramp angle have the most dominant effect on the gait pattern as compared with the changes in the hip mass, ramp surface friction and size of the flat feet. More specifically, as the ramp angle increases, the step length increases while the range of the side-to side rocking angle decreases and the step length dictates the walking speed and the gravitational power. Another finding, is that adding a hip mass improves the walking efficiency by allowing the mechanism to walk on a flatter ramp. This research enables us to gain a better understanding of the mechanics of walking. Such an understanding will have a direct impact on better design of prostheses and on the active control aspects of bipedal robots.
A chess-playing robot control system based on Windows NT+RTX
Authors: He Jilin , Yang Ruqing , Zhao Qunfei , Wang Chunxiang
Published: May 2004

This paper presents the control system of a chess-playing robot developed by the Research Institute of Robots at the Shanghai Jiaotong University. Thanks to the Windows NT operation system and the RTX (Real-Time eXtension), the whole system can achieve good real-time performance. The control system, which is supported by a standard PC hardware platform and a modularized structure of system software, is open-ended and easily expansible.