bluuebunny/crossref_metadata_2025 huggingface dataset:
On the pattern of discovery of introduced species
Authors: Costello Christopher J. , Solow Andrew R.
Published: March 2003

Introductions of nonindigenous species can have significant effects. It is commonly claimed that the rate of species introductions to the United States has increased over time. This claim is based in part on the increasing rate of discoveries of introduced species. This discovery rate is influenced by factors other than the introduction rate. These include the sampling rate and population growth in the introduced species. In this article, we show that the discovery rate can increase even when there is no increase in either the introduction rate or the sampling rate. This suggests that the basis for some claims regarding an increasing rate of introductions may be invalid.
Interplay of the
Arabidopsis
nonhost resistance gene
NHO1
with bacterial virulence
Authors: Kang Li , Li Jianxiong , Zhao Tiehan , Xiao Fangming , Tang Xiaoyan , Thilmony Roger , He ShengYang , Zhou Jian-Min
Published: March 2003

It is poorly understood why a particular plant species is resistant to the vast majority of potential pathogens that infect other plant species, a phenomenon referred to as “nonhost” resistance. Here, we show that
Arabidopsis NHO1
, encoding a glycerol kinase, is required for resistance to and induced by
Pseudomonas syringae
isolates from bean and tobacco.
NHO1
is also required for resistance to the fungal pathogen
Botrytis cinerea
, indicating that
NHO1
is not limited to bacterial resistance. Strikingly,
P. s.
pv.
tomato
DC3000, an isolate fully virulent on
Arabidopsis
, actively suppressed the
NHO1
expression. This suppression is abolished in
coi1
plants, indicating that DC3000 required an intact jasmonic acid signaling pathway in the plant to suppress
NHO1
expression. Constitutive overexpression of
NHO1
led to enhanced resistance to this otherwise virulent bacterium. The presence of
avrB
in DC3000, which activates a cultivar-specific “gene-for-gene” resistance in
Arabidopsis
, restored the induction of
NHO1
expression. Thus,
NHO1
is deployed for both general and specific resistance in
Arabidopsis
and targeted by the bacterium for parasitism.
An A−71C substitution in a green gene at the second position in the red/green visual-pigment gene array is associated with deutan color-vision deficiency
Authors: Ueyama Hisao , Li Yao-Hua , Fu Gui-Lian , Lertrit Patcharee , Atchaneeyasakul La-ongsri , Oda Sanae , Tanabe Shoko , Nishida Yasuhiro , Yamade Shinichi , Ohkubo Iwao
Published: March 2003

We studied 247 Japanese males with congenital deutan color-vision deficiency and found that 37 subjects (15.0%) had a normal genotype of a single red gene followed by a green gene(s). Two of them had missense mutations in the green gene(s), but the other 35 subjects had no mutations in either the exons or their flanking introns. However, 32 of the 35 subjects, including all 8 subjects with pigment-color defect, a special category of deuteranomaly, had a nucleotide substitution, A−71C, in the promoter of a green gene at the second position in the red/green visual-pigment gene array. Although the −71C substitution was also present in color-normal Japanese males at a frequency of 24.3%, it was never at the second position but always found further downstream. The substitution was found in 19.4% of Chinese males and 7.7% of Thai males but rarely in Caucasians or African Americans. These results suggest that the A−71C substitution in the green gene at the second position is closely associated with deutan color-vision deficiency. In Japanese and presumably other Asian populations further downstream genes with −71C comprise a reservoir of the visual-pigment genes that cause deutan color-vision deficiency by unequal crossing over between the intergenic regions.
Low‐cost visual localization and mapping for consumer robotics
Authors: Pirjanian Paolo , Karlsson Niklas , Goncalves Luis , Di Bernardo Enrico
Published: March 2003

One difficult problem in robotics is localization: the ability of a mobile robot to determine its position in the environment. Roboticists around the globe have been working to find a solution to localization for more than 20 years; however, only in the past 4‐5 years we have seen some promising results. In this work, we describe a first‐of‐a‐kind, breakthrough technology for localization that requires only one low‐cost camera (less than 50USD) and odometry to provide localization. Because of its low‐cost and robust performance in realistic environments, this technology is particularly well‐suited for use in consumer and commercial applications.
Innovation at IMTS
Authors: Bloss Richard
Published: March 2003

Robotic technology in North America is moving in opposing directions, toward smaller more compact pre‐engineered packages and faster operating speeds and to reach more applications, into greater payload capacity and greater reach. Suppliers of end of arm equipment are matching the greater payload designs with quick exchange units to match the new higher load capacity.
Pane relief: robotic solutions for car windshield assembly
Authors: Mazzocchi Enrico
Published: March 2003

Just looking through a car's windshield does not give us much reason to wonder about how it is made. The idea that special manufacturing expertise might be required can hardly occur to anyone, but that is exactly what is needed to ensure crystal‐clear visibility, not to mention a perfect fit every time one is pressed into place on a car production line. Comprising two thin glass sheets joined by a vinyl interlayer, windshields are assembled – usually manually – to a very precise product and environmental specifications. To make sure this is done as perfectly as possible, the industry invests heavily in the equipment used for their fabrication. ABB has now developed a robot‐based Compact Assembling System for the automatic assembly of laminated windshields that speeds up production and increases cost efficiency.
Disaster management and the role of the intelligence and security services
Authors: Trim Peter R.J.
Published: March 2003

The intelligence and security services are working closely with law enforcement agencies to counteract the activities of organized criminal syndicates and international terrorist organizations. Intelligence work is expected to become more broad based in the future and experts from the private sector will work more closely with personnel from the public sector. A number of long‐term workable partnership arrangements will be formed based on trustworthy behaviour. A greater commitment to disaster management and recovery should witness a greater emphasis on business continuity planning, and this should result in more robust corporate security systems being developed and installed.
COMPUTING INVARIANT SETS
Authors: HOMBURG ALE JAN , DE VILDER ROBIN , SANDS DUNCAN
Published: March 2003

We describe algorithms for computing hyperbolic invariant sets of diffeomorphisms and their stable and unstable manifolds. This includes the calculation of Smale horseshoes and the stable and unstable manifolds of periodic points in any finite dimension.
PARTIAL OBSERVERS AND PARTIAL SYNCHRONIZATION
Authors: SANTOBONI GIOVANNI , POGROMSKY ALEXANDER YU. , NIJMEIJER HENK
Published: March 2003

In this Letter we analyze the concept of partial synchronization as observer design. Our aim is to estimate a signal, the function of the coordinates of a particular system that, when considering a specific output, is not necessarily fully observable.
ON MULTITASKING IN PARALLEL CHEMICAL PROCESSORS: EXPERIMENTAL FINDINGS
Authors: DE LACY COSTELLO B. P. J. , ADAMATZKY A. I.
Published: March 2003

A parallel chemical processor is a thin-layer of a reagent mixture which reacts to changes in its concentration — data configuration — in a predictable way to form a stationary pattern corresponding to the concentration of the reagent — result configuration. A computation in the chemical processor is implemented via the spreading and interaction of diffusive or phase waves. We design chemical processors that solve a classical problem of computational geometry — computation of a Voronoi diagram. Namely, we study the possibility of designing a multitasking chemical processor that independently and simultaneously computes Voronoi diagrams of two different data planar sets. We define a two-tasking chemical processor as two distinct reactant–substrate couples within a reaction–diffusion processor that solve separate tasks but share the same physical space. A micro-volume of the physical space is an elementary processor of a massively parallel chemical processor, therefore two reaction–diffusion systems occupying the same space are considered to be a single chemical processor. We found that when a single reactant is on a gel layer containing either one or two substrates the same single Voronoi diagram corresponding to the original location of the reactant drops is constructed. However, when two reactants are on a gel containing two substrates and where there is extremely limited cross reactivity between the separate reactant-substrate couples then two Voronoi diagrams of the data planar points (two sets of drops of separate reactants) are constructed; the third "complementary" pattern is also constructed. The first Voronoi diagram constructed is identical at least in position to the one constructed where one reactant was with one substrate (with the same original configuration of reactant drops). After the formation of the first diagram is completed the diffusion fronts corresponding to unlike reactants cross and are only annihilated where they meet another reactant front composed of the same reactant. The result is the computation of two additional Voronoi diagrams pertaining to the spatial positions of the two sets of reactant drops. The outcomes of this experiment albeit in a simple chemical system are significant because the system constitutes the first class of a synthetic chemical parallel processor capable of at least two computations at the same time.
AN ONTOLOGY FOR SEMANTIC INTEGRATION OF LIFE SCIENCE WEB DATABASES
Authors: MILED ZINA BEN , WEBSTER YUE W. , LIU YANG , LI NIANHUA
Published: March 2003

The incompatibilities among complex data formats and various schema used by biological databases that house these data are becoming a bottleneck in biological research. For example, biological data format varies from simple words (e.g. gene name), numbers (e.g. molecular weight) to sequence strings (e.g. nucleic acid sequence), to even more complex data formats such as taxonomy trees. Some information is embedded in narrative text, such as expert comments and publications. Some other information is expressed as graphs or images (e.g. pathways networks). The confederation of heterogeneous web databases has become a crucial issue in today's biological research. In other words, interoperability has to be archieved among the biological web databases and the heterogeneity of the web databases has to be resolved. This paper presents a biological ontology, BAO, and discusses its advantages in supporting the semantic integration of biological web databases are discussed.
THE DISSOCIATION AND ISOMERIZATION REACTIONS OF N11 ISOMERS
Authors: LI QIAN SHU , LIU YONG DONG
Published: March 2003

The dissociation and isomerization reactions of N 11 isomers, including the two structures 1 and 3 previously studied as well as the three new structures 2, 4, and 5, were investigated by the density functional theory (DFT) at the B3LYP/6-31G(d), B3LYP/6-311G(d), and B3LYP/6-311+G(3df)//B3LYP/6-311G(d) levels of theory. The results indicate that, similar to previous results on N 9 and N 10 isomers, the barrier heights for structures 1 and 2 to lose N 2 are about 10–15 kcal/mol whereas the barrier heights for structures 1–3 to lose N 3 are about 25–30 kcal/mol. Therefore, it seems that N 2 is easier to be eliminated than is N 3 from the relatively larger nitrogen isomers. In addition, for structures 1 and 3, both dissociation and isomerization can occur in the N8–N9 bond, due partly to its character in having an aromatic bond. Moreover, the isomerization is preferred compared with dissociation because of its relatively lower energy barrier height.
IMPROVED PREDICTION OF CRITICAL TEMPERATURES AND CRITICAL PRESSURES FOR NORMAL ALKANES CnH2n+2 WITH n ≤ 43 AND BRANCHED ALKANES WITH n ≤ 9 FROM RATHER SIMPLE TOPOLOGICAL DESCRIPTORS
Authors: KRENKEL GERMÁN , CASTRO EDUARDO A.
Published: March 2003

Critical temperatures and critical pressures are calculated within the framework of the QSPR theory for a set of normal alkanes and a set of branched alkanes. The chosen molecular descriptors are the simplest topological properties: number of atoms, coordination numbers and chemical bonds. Predictions are quite satisfactory when compared with the available experimental data. These results are in line with other similar ones for a set of diverse organic compounds. Some possible future extensions are pointed out.
Information Technology and U.S. Energy Consumption: Energy Hog, Productivity Tool, or Both?
Authors: Laitner John A. “Skip”
Published: March 2003

A significant debate has emerged with respect to the energy requirements of the Internet. The popular literature has echoed a misleading study that incorrectly suggests the growth of the information economy will require huge amounts of new energy resources. Even correcting the misleading assumptions in that study, discussion on this topic tends to result in a highly limited and unsatisfactory review of many larger issues. Although the evidence suggests a relatively small amount of energy is required to power today's information needs—;about 3% of total electricity consumption in the United States—;the complexity and connectivity of the Internet, and, more generally, the information economy, yield a deep uncertainty about the eventual long‐term impact on energy consumption. Although we may not yet be able to generalize about the future long‐term energy needs associated with the information economy, the evidence points to continuing technical changes and the growing substitution of knowledge for material resources. These interrelated trends will likely generate small decreases in energy intensity and reduce subsequent environmental impacts relative to many baseline projections. Despite these trends, a number of questions need to be addressed before any solid long‐term conclusions might be forthcoming. The article reviews some of the dimensions of these possible changes and suggests further directions for research that may help answer these important questions.
Expression of hepcidin in hereditary hemochromatosis: evidence for a regulation in response to the serum transferrin saturation and to non-transferrin-bound iron
Authors: Gehrke Sven G. , Kulaksiz Hasan , Herrmann Thomas , Riedel Hans-Dieter , Bents Karin , Veltkamp Claudia , Stremmel Wolfgang
Published: March 2003

Experimental data suggest the antimicrobial peptide hepcidin as a central regulator in iron homeostasis. In this study, we characterized the expression of human hepcidin in experimental and clinical iron overload conditions, including hereditary hemochromatosis. Using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we determined expression of hepcidin and the most relevant iron-related genes in liver biopsies from patients with hemochromatosis and iron-stain-negative control subjects. Regulation of hepcidin mRNA expression in response to transferrin-bound iron, non-transferrin-bound iron, and deferoxamine was analyzed in HepG2 cells. Hepcidin expression correlated significantly with serum ferritin levels in controls, whereas no significant up-regulation was observed in patients with hemochromatosis despite iron-overload conditions and high serum ferritin levels. However, patients with hemochromatosis showed an inverse correlation between hepcidin transcript levels and the serum transferrin saturation. Moreover, we found a significant correlation between hepatic transcript levels of hepcidin and transferrin receptor-2 irrespective of the iron status. In vitro data indicated that hepcidin expression is down-regulated in response to non-transferrin-bound iron. In conclusion, the presented data suggest a close relationship between the transferrin saturation and hepatic hepcidin expression in hereditary hemochromatosis. Although the causality is not yet clear, this interaction might result from a down-regulation of hepcidin expression in response to significant levels of non-transferrin-bound iron. (Blood. 2003;102:371-376)
Alterations in the intrinsic properties of the GPIbα–VWF tether bond define the kinetics of the platelet-type von Willebrand disease mutation, Gly233Val
Authors: Doggett Teresa A. , Girdhar Gaurav , Lawshe Avril , Miller Jonathan L. , Laurenzi Ian J. , Diamond Scott L. , Diacovo Thomas G.
Published: March 2003

Platelet-type von Willebrand disease (PTVWD) is a bleeding disorder in which an increase of function mutation in glycoprotein Ibα (GPIbα), with respect to binding of von Willebrand factor (VWF), results in a loss of circulating high molecular weight VWF multimers together with a mild-moderate thrombocytopenia. To better ascertain the specific perturbations in adhesion associated with this disease state, we performed a detailed analysis of the kinetic and mechanical properties of tether bonds formed between PT-VWD platelets and the A1-domain of VWF. Results indicate that the GPIbα mutation, Gly233Val, promotes and stabilizes platelet adhesion to VWF at shear rates that do not support binding between the native receptor-ligand pair due to enhanced formation and increased longevity of the mutant tether bond (k0off values for mutant versus native complex of 0.67 ± 0.11 s-1 and 3.45 ± 0.37 s-1, respectively). By contrast, the sensitivity of this interaction to an applied force, a measure of bond strength, was similar to the wild-type (WT) receptor. Although the observed alterations in the intrinsic properties of the GPIbα–VWF tether bond are comparable to those reported for the type 2B VWD, distinct molecular mechanisms may be responsible for these function-enhancing bleeding disorders, as interactions between the mutant receptor and mutant ligand resulted in a greater stability in platelet adhesion. We speculate that the enhanced cellular on-rate together with the prolongation in the lifetime of the mutant receptor-ligand bond contributes to platelet aggregation in circulating blood by permitting the formation of multiple GPIbα–VWF-A1 interactions. (Blood. 2003;102:152-160)
A role for actin dynamics in individualization during spermatogenesis inDrosophila melanogaster
Authors: Noguchi Tatsuhiko , Miller Kathryn G.
Published: March 2003

In order to better understand the mechanism of sperm individualization during spermatogenesis in Drosophila melanogaster, we have developed an in vitro culture system in which we can perform live observation of individualization in isolated cysts. The whole process of individualization,during which a bundle of 64 syncytial spermatids is separated into individual sperm, takes place in these cultures. Individualization complexes, which consist of 64 cones of actin that assemble around the sperm nuclei, move to the basal end of the tails, forming a characteristic `cystic bulge' that contains an accumulation of cytoplasm, syncytial membrane and vesicles. The cystic bulge is the site of membrane remodeling and its movement was used to follow the progress of individualization. The speed of cystic bulge movement is fairly constant along the length of the cyst. Actin drugs, but not microtubule drugs inhibit cystic bulge movement, suggesting that the movement requires proper actin dynamics but not microtubules. GFP-tagged actin was expressed in the cyst and fluorescence recovery after photobleaching was monitored using confocal microscopy to analyze actin dynamics in cones. Actin turns over throughout the cone, with that at the leading edge of the cones turning over with slightly faster kinetics. Actin does not treadmill from the front to the back of the cone. Actin in moving actin cones turns over in about 12 minutes, although prior to onset of movement, turnover is much slower. Visualization of membrane using FM1-43 reveals that the cystic bulge has an extremely complicated series of membrane invaginations and the transition from syncytial to individualized spermatids occurs at the front of the actin cones. We also suggest that endocytosis and exocytosis might not be important for membrane remodeling. This system should be suitable for analysis of defects in male sterile mutants and for investigating other steps of spermatogenesis.
Directional guidance of interneuron migration to the cerebral cortex relies on subcortical Slit1/2-independent repulsion and cortical attraction
Authors: Marín Oscar , Plump Andrew S. , Flames Nuria , Sánchez-Camacho Cristina , Tessier-Lavigne Marc , Rubenstein John L. R.
Published: March 2003

Tangential migration from the basal telencephalon to the cortex is a highly directional process, yet the mechanisms involved are poorly understood. Here we show that the basal telencephalon contains a repulsive activity for tangentially migrating cells, whereas the cerebral cortex contains an attractive activity. In vitro experiments demonstrate that the repulsive activity found in the basal telencephalon is maintained in mice deficient in both Slit1 and Slit2, suggesting that factors other than these are responsible for this activity. Correspondingly, in vivo analysis demonstrates that interneurons migrate to the cortex in the absence ofSlit1 and Slit2, or even in mice simultaneously lackingSlit1, Slit2 and netrin 1. Nevertheless, loss ofSlit2 and, even more so, Slit1 and Slit2 results in defects in the position of other specific neuronal populations within the basal telencephalon, such as the cholinergic neurons of the basal magnocellular complex. These results demonstrate that whereas Slit1and Slit2 are not necessary for tangential migration of interneurons to the cortex, these proteins regulate neuronal migration within the basal telencephalon by controlling cell positioning close to the midline.
Wear and deformation of ceramic-on-polyethylene total hip replacements with joint laxity and swing phase microseparation
Authors: Williams S , Butterfield M , Stewart T , Ingham E , Stone M , Fisher J
Published: March 2003

Wear of polyethylene and the resulting wear debris-induced osteolysis remains a major cause of long-term failure in artificial hip joints. There is interest in understanding engineering and clinical conditions that influence wear rates. Fluoroscopic studies have shown separation of the head and the cup during the swing phase of walking due to joint laxity. In ceramic-on-ceramic hips, joint laxity and microseparation, which leads to contact of the head on the superior rim of the cup, has led to localized damage and increased wear in vivo and in vitro. The aim of this study was to investigate the influence of joint laxity and microseparation on the wear of ceramic on polyethylene artificial hip joints in an in vitro simulator. Microseparation during the swing phase of the walking cycle produced contact of the ceramic head on the rim of the polyethylene acetabular cup that deformed the softer polyethylene cup. No damage to the alumina ceramic femoral head was found. Under standard simulator conditions the volume change of the moderately crosslinked polyethylene cups was 25.6 ± 5.3 mm3/million cycles and this reduced to 5.6 ± 4.2 mm3/million cycles under microseparation conditions. Testing under microseparation conditions caused the rim of the polyethylene cup to deform locally, possibly due to creep, and the volume change of the polyethylene cup when the head relocated was substantially reduced, possibly due to improved lubrication.

Joint laxity may be caused by poor soft tissue tension or migration and subsidence of components. In ceramic-on-polyethylene acetabular cups wear was decreased with a small degree of joint laxity, while in contrast in hard-on-hard alumina bearings, microseparation accelerated wear. These findings may have significant implications for the choice of fixation systems to be used for different types of bearing couples.
Antibiotic Resistance Among Gram-Negative Bacilli in US Intensive Care Units
Authors: Neuhauser Melinda M. , Weinstein Robert A. , Rydman Robert , Danziger Larry H. , Karam George , Quinn John P.
Published: March 2003

Context

Previous surveillance studies have documented increasing rates of antimicrobial resistance in US intensive care units (ICUs) in the early 1990s.

Objectives

To assess national rates of antimicrobial resistance among gram-negative aerobic isolates recovered from ICU patients and to compare these rates to antimicrobial use.

Design and Setting

Participating institutions, representing a total of 43 US states plus the District of Columbia, provided antibiotic susceptibility results for 35 790 nonduplicate gram-negative aerobic isolates recovered from ICU patients between 1994 and 2000.

Main Outcome Measures

Each institution tested approximately 100 consecutive gram-negative aerobic isolates recovered from ICU patients. Organisms were identified to the species level. Susceptibility tests were performed, and national fluoroquinolone consumption data were obtained.

Results

The activity of most antimicrobial agents against gram-negative aerobic isolates showed an absolute decrease of 6% or less over the study period. The overall susceptibility to ciprofloxacin decreased steadily from 86% in 1994 to 76% in 2000 and was significantly associated with increased national use of fluoroquinolones.

Conclusions

This study documents the increasing incidence of ciprofloxacin resistance among gram-negative bacilli that has occurred coincident with increased use of fluoroquinolones. More judicious use of fluoroquinolones will be necessary to limit this downward trend.
The National Resident Matching Program and Antitrust Law
Authors: Miller Frances H. , Greaney Thomas L.
Published: March 2003

In May 2002, a group of physicians filed a class action lawsuit alleging that the National Resident Matching Program (NRMP) violates antitrust laws. The plaintiffs contend that NRMP practices have stabilized lower-than-competitive wages and imposed exhausting working conditions on residents. They also maintain that NRMP procedures virtually force applicants for house officer positions to forfeit their right to negotiate for better wages and conditions. The plaintiffs also allege that the defendants have collectively fostered anticompetitive accreditation standards through the Accreditation Council for Graduate Medical Education. Jung v Association of American Medical Colleges could present antitrust law with some difficult challenges. Although the matching program on its face appears to limit competition in a manner that previous cases have found illegal, it operates in the context of important professional activities (medical education and quality improvement) that may generate some judicial deference. At this early stage, no confident prediction can be made about the outcome of the case if it goes to trial; however, the plaintiffs appear to have a plausible case under existing antitrust doctrine, and lengthy litigation is possible. Given the important questions that the litigation will not address, such as the potential costs of a finding of illegality to the government and other payers, and the impact of such a finding on the health care system as a whole, a legislative solution seems highly desirable.
Bounds on the complexity of neural‐network models and comparison with linear methods
Authors: Hlaváčková‐Schindler Kateřina , Sanguineti Marcello
Published: March 2003

A class of non‐linear models having the structure of combinations of simple, parametrized basis functions is investigated; this class includes widespread neural networks in which the basis functions correspond to the computational units of a type of networks. Bounds on the complexity of such models are derived in terms of the number of adjustable parameters necessary for a given modelling accuracy. These bounds guarantee a more advantageous tradeoff than linear methods between modelling accuracy and model complexity: the number of parameters may increase much more slowly, in some cases only polynomially, with the dimensionality of the input space in modelling tasks. Polynomial bounds on complexity allow one to cope with the so‐called ‘curse of dimensionality’, which often makes linear methods either inaccurate or computationally unfeasible. The presented results let one gain a deeper theoretical insight into the effectiveness of neural‐network architectures, noticed in complex modelling applications. Copyright © 2003 John Wiley & Sons, Ltd.
Dendrimer‐Based Hydroxyapatite Composites with Remarkable Materials Properties
Authors: Donners J.J.J.M. , Nolte R.J.M. , Sommerdijk N.A.J.M.
Published: March 2003

The biomimetic formation of hydroxyapatite composites using complexes of alkylated dendrimers (see Figure) and surfactants as templates is described. Despite a high organic content, high stiffness is displayed, and for one dendrimer/surfactant combination investigated, significant toughening is observed.
Guest Editorial: Chemistry and Physics of Nanowires
Authors: Xia Y. , Yang P.
Published: March 2003

In this Editorial for the Nanowires Special Issue of Advanced Materials, Younan Xia and Peidong Yang welcome you to this survey of the fast‐moving area of nanowire research. Communications and Research News articles covering vapor‐phase, solution‐based, and template‐directed routes to the synthesis of nanowires, self‐assembly with nanowires as the building blocks, and new physics associated with 1D nanostructures can all be found within.
High‐Quality Ultra‐Fine GaN Nanowires Synthesized Via Chemical Vapor Deposition
Authors: Chen X. , Xu J. , Wang R.M. , Yu D.
Published: March 2003

GaN nanowires with diameters in the quantum‐confinement size regime (4–10 nm, ∼10 nm in Figure) are prepared on large‐area substrates through catalytic reaction of Ga and NH3 in a hot‐filament chemical vapor deposition system. The synthetic method is reproducible and could be applied to the growth of other semiconductor nanostructures.
Growth of Arrayed Nanorods and Nanowires of ZnO from Aqueous Solutions
Authors: Vayssieres L.
Published: March 2003

A novel approach to the rational fabrication of smart and functional metal oxide particulate thin films and coatings is demonstrated on the growth of ZnO nanowires and oriented nanorod arrays. The synthesis involves a template‐less and surfactant‐free aqueous method, which enables the generation of, at large‐scale, low‐cost, and moderate temperatures, advanced metal oxide thin films with controlled complexity. The strategy consists of monitoring of the nucleation, growth, and aging processes by means of chemical and electrostatic control of the interfacial free energy. It enables the control of the size of nano‐, meso‐, and microcrystallites, their surface morphology, orientations onto various substrates, and crystal structure.
High incidence of autoimmune alterations in chronic myeloid leukemia patients treated with interferon‐α
Authors: Steegmann J.L. , Requena M.J. , Martín‐Regueira P. , de la Cámara R. , Casado F. , Salvanés F. Rodriguez , Fernández Rañada J.M.
Published: March 2003

Interferon‐α is the frontline therapy of the majority of chronic myeloid leukemia (CML) patients who are not eligible for bone marrow transplantation. Many patients are treated for long periods, and there is concern about the long‐term immune effects of its use. Autoimmune disorders in patients treated with IFN‐α may be related to the direct immunomodulating properties of IFN or may be linked to a possible toxic effect in target organs, triggering autoimmunity. On the other hand, the immune effects of IFN may play a role in its therapeutic actions. The aims of our study were to assess the incidence of autoimmune phenomena in these patients, and to measure the possible association between the generation of autoimmune phenomena and the antileukemic effect of IFN α. Therefore, 46 patients with Ph1+ CML in the first chronic phase were studied for the appearance of immune complications, their connection to IFN dose, time of appearance, and the possible association with the response to treatment. Autoimmune abnormalities have been found in 28% of our patients. Moreover, a significant association was found between autoimmune alterations and female sex (P = 0.02, OR 4.5, 95% CI 1.13–17.9) and a longer treatment time (1.6 vs. 4.1 years) (P = 0.02; OR 1.01, 95% CI 1–1.02). The Kaplan–Meier estimated probability of obtaining a cytogenetic response was significantly higher in patients who developed autoimmune alterations (P = 0.049), and this difference was also evident in Cox's analysis when controlling with other potentially confounding variables (P = 0.078). We conclude that CML patients treated with IFN alpha have a high incidence of autoimmune phenomenon. Am. J. Hematol. 72:170–176, 2003. © 2003 Wiley‐Liss, Inc.
Progressive osseous heteroplasia in the face of a child
Authors: Faust Russell A. , Shore Eileen M. , Stevens Christopher E. , Xu Meiqi , Shah Shefali , Phillips C. Douglas , Kaplan Frederick S.
Published: March 2003

We describe a rare case of progressive osseous heteroplasia of the face in a child. Biopsy showed osteoma cutis superficially with ectopic bone formation in the deeper tissues including skeletal muscle. Analysis of DNA from peripheral blood leukocytes showed mutations in the gene encoding the alpha subunit of the stimulatory G protein of adenylyl cyclase (GNAS1), confirming the diagnosis of progressive osseous heteroplasia.
Further delineation of the behavioral and neurologic features in Costello syndrome
Authors: Kawame Hiroshi , Matsui Mihoko , Kurosawa Kenji , Matsuo Mari , Masuno Mitsuo , Ohashi Hirofumi , Fueki Noboru , Aoyama Kouki , Miyatsuka Yukiko , Suzuki Kaoru , Akatsuka Akira , Ochiai Yukikatsu , Fukushima Yoshimitsu
Published: March 2003

To describe clinical and neurodevelopmental phenotypes of Costello syndrome, we performed a retrospective review of the clinical records and findings in 10 children with Costello syndrome. All patients showed significant postnatal growth retardation and severe feeding difficulties leading to failure to thrive from early infancy. All required tube feeding and some needed high‐calorie formulas for variable periods. Developmental quotients/IQs in seven children were 50 or less, and three were in the mildly retarded range. Five had seizures. Remarkable manifestations not previously reported were the characteristic behavior in infancy. Although happy and sociable personality was always emphasized in the genetic literature, all children showed significant irritability, including hypersensitivity to sound and tactile stimuli, sleep disturbance, and excess shyness with strangers in infancy. Those symptoms usually disappeared around age 2–4 years. Other clinical signs included cardiac abnormalities (8), musculoskeletal abnormalities (10), ophthalmological manifestations (5), increased urinary vanillymandelic acid (VMA) and homovanillic acid (HVA) (3), rhabdomyosarcoma (1), laryngomalacia (1), and cryptorchidism (1). Only three girls had papillomata. Family histories were negative for Costello syndrome. In conclusion, we confirm the wide spectrum of mental function in patients with Costello syndrome, which ranges from severe to mild. During infancy Costello syndrome showed remarkable irritability with severe feeding problems, which attributes significant difficulties to the parents of affected children. © 2003 Wiley‐Liss, Inc.
Mechanical properties of Mg(OH)2/polypropylene composites modified by functionalized polypropylene
Authors: Mai K. , Qiu Y. , Lin Z.
Published: March 2003

Modified Mg(OH)2/polypropylene (PP) composites were prepared by the addition of functionalized polypropylene (FPP); and acrylic acid (AA) and by the formation of in situ FPP. The effects of the addition of FPP and AA and the formation of in situ FPP on the mechanical properties of Mg(OH)2/PP composites were investigated. Experimental results indicated that the addition of Mg(OH)2 markedly reduced the mechanical properties of PP. The extent of reduction in notch impact strength of PP was higher than that in flexural strength and tensile strength. However, tensile modulus and flexural modulus increased with increased Mg(OH)2 content. The addition of FPP facilitated the improvement in the flexural strength and tensile strength of Mg(OH)2/PP composites. The higher the Mg(OH)2 content was, the more significant the effect of FPP was. The incorporation of AA resulted in further increased mechanical properties, in particular the flexural strength, tensile strength, and notch impact strength of Mg(OH)2/PP composites containing high levels of Mg(OH)2. It not only improved mechanical properties but also increased the flame retardance of Mg(OH)2/PP composites. Although the mechanical properties of composites modified by the formation of in situ FPP were lower than those of composites modified by only the addition of AA in the absence of diamylperoxide, the mechanical properties did not decline with increased Mg(OH)2 content. Moreover, the mechanical properties increased with increasing AA content. The addition of an oxidation resistant did not influence the mechanical properties of the modified Mg(OH)2/PP composites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2139–2147, 2003
Scaling functions of polymer‐induced turbulent drag reduction focusing on the polymer–solvent interaction
Authors: Kim Chul A. , Jhon Myung S. , Choi Hyoung J.
Published: March 2003

Based on turbulent drag reduction characteristics of polystyrene and polyisobutylene in a pipe flow and a rotating‐disk flow, respectively, a relationship between polymer concentration and drag reduction at a given Reynolds number was considered. The universal drag reduction equation of a three‐parameter relationship between drag reduction and polymer concentration was modified using intrinsic concentration and intrinsic viscosity, and it was then found to be the most useful formula for correlating DR data, especially for polymer–solvent interactions in a turbulent flow. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1836–1839, 2003
The viscoelastic properties of natural rubber pressure‐sensitive adhesive using acrylic resin as a tackifier
Authors: Leong Yub Choong , Lee Larry Mook Swee , Gan Seng Neon
Published: March 2003

Acrylic tackifier resins were prepared by free radical polymerization. A natural rubber base was prepared from Standard Malaysian Rubber through mechanical milling. The acrylic tackifier was blended with the rubber base in various ratios. The blends were coated onto strips of paper and tested for shear and peel strengths. Circular samples of the blends were cast onto release paper and their viscoelastic properties studied using DMTA. On plotting storage modulus G′ against frequency, differences between the low frequencies and high frequencies explain the change in pressure‐sensitive adhesive (psa) properties as the percentage of tackifier resin was varied. Blends with good psa have higher loss tangent at higher frequencies. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2118–2123, 2003
Anionic ring‐opening polymerization of adipic anhydride initiated by potassium poly(ethylene glycol)ate
Authors: Deng Xianmo , Li Zhen , Yuan Minglong , Hao Jianyuan
Published: March 2003

Poly(adipic anhydride) (PAA) was prepared by the ring‐opening polymerization of adipic anhydride (AA) initiated by potassium poly(ethylene glycol)ate. The effects of various factors, such as the amount of initiator, concentration of the monomer, reaction time and temperature, and polarity of the solvent on the polymerization were investigated. The crude polymerized product was a mixture of PAA homopolymer and poly(ethylene glycol)–poly(adipic anhydride) block copolymer, as confirmed by 1H‐NMR and gel permeation chromatography. Chain‐transfer reactions occurred intensively for the AA polymerization in both the nonpolar solvent toluene and the polar solvents CHCl3 and tetrahydrofuran, which predominantly determined the molecular weight and the monomer conversion for the polymerized product. The lower monomer conversion in toluene was ascribed to a lower livingness for the initiator in the nonpolar solvent when compared with other two, polar solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2194–2201, 2003
Surface analysis of cotton fabrics fluorinated in radio‐frequency plasma
Authors: McCord M. G. , Hwang Y. J. , Qiu Y. , Hughes L. K. , Bourham M. A.
Published: March 2003

Cotton fabrics were treated by radio‐frequency plasma with tetrafluoromethane (CF4) and hexafluoropropene (C3F6) gases under different exposure times, pressures, and power levels. The hydrophobicity and water repellency were analyzed with measurements of the cosine of the contact angle (cos θ) and wet‐out time. The hydrophobicity was enhanced with treatments of both gases. X‐ray photoelectron spectroscopy (XPS) revealed increases in the surface fluorine content of 1–2% for CF4 plasma and of 2.3–7.8% for C3F6 plasma. The relative chemical composition of the C1s spectra after CF4 and C3F6 plasma treatments showed increases in the relative amounts of COC and fluorocarbon groups (CF, CF2, and CF3), whereas peak areas for COH and COOH decreased. The hydrophobicity was enhanced by the increase in the fluorine content and fluorocarbon groups. C3F6 plasma treatment resulted in higher hydrophobicity than CF4 plasma treatment according to not only cos θ and wet‐out measurements but also XPS analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2038–2047, 2003
Conjugates of poly(N‐isopropyl acrylamide‐co‐acrylic acid) with alanine monopeptide, dipeptide, and tripeptide
Authors: Bulmuş Volga , Patır Süleyman , Ali Tuncel S. , Pişkin Erhan
Published: March 2003

A random copolymer of N‐isopropyl acrylamide (NIPAAm) and acrylic acid (AAc) with an AAc content of 3.1 ± 0.19 mmol of carboxylic acid groups per gram of the copolymer and with a number‐average molecular weight of 1400 was synthesized by free‐radical polymerization with 2,2′‐azoisobutyronitrile in dimethylformamide. Then, monopeptide, dipeptide, and tripeptide (i.e., alanine) conjugates of this copolymer were prepared with their carboxyl‐end‐protected (with methyl ester hydrochloride) form of alanine, with a water‐soluble carbodiimide. Of the carboxylic acids, 93, 69, and 57% were conjugated (loaded) with alanine at the monopeptide, dipeptide, and tripeptide conjugation steps, respectively. The chemical structures of the copolymer and conjugates were analyzed by Fourier transform infrared and 1H‐NMR, which revealed the conjugate formation. Amino acid conjugation caused significant decreases in the lower critical solution temperatures (LCST) of the copolymer, especially at pH 7.4. The LCST values of the dipeptide and tripeptide conjugates of poly(NIPAAm‐co‐AAc) at both pH 4.0 and 7.4 shifted to significantly higher temperatures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2012–2019, 2003
Ditch communities: a major contributor to floodplain biodiversity
Authors: Armitage Patrick D. , Szoszkiewicz Krzysztof , Blackburn John H. , Nesbitt Ian
Published: March 2003

Chalk stream floodplains are extensively managed and the high degree of connectivity associated with water meadows has been severely reduced. The main contributor to aquatic biodiversity is perceived to be the river itself. Ditches in these areas have been largely ignored as a contributor to total diversity.

Separate surveys of instream, bankside and ditch macroinvertebrates in a small area of floodplain provided a unique opportunity to assess the relative contribution of each locality to total aquatic diversity. The fauna and flora of a ditch on the lower River Frome floodplain was examined and compared with studies of adjacent bankside and instream habitat. A total of 145 macroinvertebrate taxa and 61 plant species were recorded from the ditch. Faunal abundance and richness were positively related to the diversity of aquatic plants. The ditch showed a clear linear trend in community type that appeared to be partly related to the acidic seepage from tertiary deposits at the source and percentage cover of vegetation.

There were large differences in the numbers of taxa collected in ditch, bankside, instream mesohabitat and RIVPACS surveys. Of the total 202 taxa recorded in the four surveys, the ditch contributed 59 unique taxa with 25 from the bankside and two and three from the mesohabitat and RIVPACS surveys, respectively.

The large contribution of the Rushton Ditch to aquatic biodiversity on the floodplain is due to three main factors: the chemically different and slow‐flowing environment, the connection to the main river, and a management regime which has halted hydroseral succession at a point where vegetation structure is for the most part open and able to support a wide range of ecological niches. The maintenance of these conditions requires sensitive management and further knowledge of the needs and interactions of faunal communities with vegetation.

Copyright © 2002 John Wiley & Sons, Ltd.
A poly(ADP‐ribose) polymerase haplotype spanning the promoter region confers susceptibility to rheumatoid arthritis
Authors: Pascual M. , López‐Nevot M. A. , Cáliz R. , Ferrer M. A. , Balsa A. , Pascual‐Salcedo D. , Martín J.
Published: March 2003

Objective

To investigate the association of the poly(ADP‐ribose) polymerase 1 (PARP‐1) gene promoter polymorphism with rheumatoid arthritis (RA) predisposition.

Methods

An association study with 213 Spanish RA patients and 242 healthy subjects was carried out to investigate the association of all known PARP‐1 gene promoter polymorphisms, i.e., a CA microsatellite repeat, a poly(A)n, and 3 single point mutations (C410T, C1362T, and G1672A), with disease susceptibility. Additionally, we analyzed the distribution of PARP‐1 polymorphisms in 58 Spanish families with 1 or more affected members.

Results

Upon complete genotyping of the panel of 455 samples, strong linkage disequilibrium was observed among the 5 PARP‐1 polymorphisms. Only 2 PARP‐1 haplotypes were detected: haplotype A (410T–[A]10–[CA]10–12–1362C, which includes short PARP‐1 CA alleles) and haplotype B (410C–[A]11–[CA]13–20–1362T, always paired with long PARP‐1 CA variants). Regarding the G1672A variation, although linkage disequilibrium was detected, it did not seem to be part of the conserved haplotypes described. Haplotype B was statistically overrepresented in the RA patient group compared with the healthy subjects (odds ratio 1.42, 95% confidence interval 1.06–1.91, P = 0.019). In addition, a significant dose effect of PARP‐1 haplotype carriage on disease predisposition was observed. Of note, within haplotype B, the PARP‐1 CA 97‐bp allele was found to be the RA‐predisposing marker (odds ratio 2.17, 95% confidence interval 1.27–3.72, P = 0.003, corrected P < 0.05).

Conclusion

Our results demonstrate the existence of 2 unique PARP‐1 haplotypes in the Spanish population and provide the first evidence that PARP‐1 haplotypes play a role in susceptibility to RA.