bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optoelectronic multiplexer for digital data processing based on lipid crystal pixels and optical fiber elements
Authors: Pérez I. , Pena J. , Torres J. , Manzanares R. , Marcos C. , Vázquez C. 
Published: April 2007

AbstractIn this work, we present an optoelectronic digital multiplexer 4:1 based on a multipixel nematic liquid crystal cell. This device uses two optical control signals to select one among four possible optical data inputs. These data signals are generated by four red LEDs, which are guided through plastic optical fiber towards liquid crystal pixels. For our purpose, only four pixels of the cell will be used to modulate the optical signal across them. Each pixel will be addressed by a square waveform coming from the conditioning circuit managed by a microcontroller system. The electronic control allows the multiplexer to work as as simple two input logical gates such as AND, NAND, OR, NOR, XOR and XNOR. The operation time of the device is limited by the response time of LC cell that is in the millisecond range.
Evaluation of infrared collimators for testing thermal imaging systems
Authors: Chrzanowski K. 
Published: April 2007

AbstractInfrared reflective collimators are important components of expensive sophisticated test systems used for testing thermal imagers. Too low quality collimators can become a source of significant measurement errors and collimators of too high quality can unnecessarily increase cost of a test system. In such a situation it is important for test system users to know proper requirements on the collimator and to be able to verify its performance. A method for evaluation of infrared reflective collimators used in test systems for testing thermal imagers is presented in this paper. The method requires only easily available optical equipment and can be used not only by collimator manufactures but also by users of test equipment to verify performance of the collimators used for testing thermal imagers.
A new multi-path scheme for adaptive computation-aware motion estimation
Authors: Jakubowski M. , Pastuszak G. 
Published: April 2007

AbstractAbility to work in a computation-limited and computation-variant environment described as “computational awareness” is a desirable feature of a real-time motion estimation system. In this paper, a new multi-path computation-aware algorithm is proposed. One-pass scheme, presented in the prior work by Chen et al., considers only one candidate point which is the median of neighbouring motion vectors (MVs). However, when computational resources are abundant, it is possible to investigate more search paths around points from the prediction set and get a significant improvement both in terms of quality and utilization of available search points (SPs). There are also other enhancements introduced regarding the way of selection of the starting SP and the search strategy, and allocation of resources, which leads to higher PSNR and a better utilization of computational resources.
Computation of Realizations Composed of Dynamic and Static Parts of Improper Transfer Matrices
Authors: Kaczorek Tadeusz 
Published: April 2007

Computation of Realizations Composed of Dynamic and Static Parts of Improper Transfer MatricesThe problem of computing minimal realizations of a singular system decomposed into a standard dynamical system and a static system of a given improper transfer matrix is formulated and solved. A new notion of the minimal dynamical-static realization is introduced. It is shown that there always exists a minimal dynamical-static realization of a given improper transfer matrix. A procedure for the computation of a minimal dynamical-static realization for a given improper transfer matrix is proposed and illustrated by a numerical example.
A Backstepping Approach to Ship Course Control
Authors: Witkowska Anna , Tomera Miroslaw , Śmierzchalski Roman 
Published: April 2007

A Backstepping Approach to Ship Course ControlAs an object of course control, the ship is characterised by a nonlinear function describing static manoeuvring characteristics that reflect the steady-state relation between the rudder deflection and the rate of turn of the hull. One of the methods which can be used for designing a nonlinear ship course controller is the backstepping method. It is used here for designing two configurations of nonlinear controllers, which are then applied to ship course control. The parameters of the obtained nonlinear control structures are tuned to optimise the operation of the control system. The optimisation is performed using genetic algorithms. The quality of operation of the designed control algorithms is checked in simulation tests performed on the mathematical model of a tanker. In order to obtain reference results to be used for comparison with those recorded for nonlinear controllers designed using the backstepping method, a control system with the PD controller is examined as well.
Zooplankton phosphorus excretion in Swarzędzkie Lake (Western Poland) and its influence on phytoplankton
Authors: Kowalczewska-Madura Katarzyna , Gołdyn Ryszard , Szyper Halina 
Published: April 2007

Abstract
Zooplankton phosphorus excretion was studied in Swarzędzkie Lake in 2000-2002. Phosphorus excretion rates were high from spring through autumn, but low in winter. The highest value, 203.7 μgP 1-1 d-1 (vertical profile mean), was recorded in June 2000. The mean rate was 26.6 μgP 1-1 d-1 and was 10 times greater for rotifers than for both cladocerans and copepods. In most months, the calculated phosphorus excretion rate was greater than the sum of tributary external phosphorus loading and internal bottom sediment loading. Nevertheless, the influence of the zooplankton phosphorus excretion rate on yearly phytoplankton abundance, biomass and chlorophyll a was not statistically significant. Yearly variance in phytoplankton variables was best explained by a canonical variable composed of internal loading and zooplankton phosphorus excretion (total redundancy 32.8%).
Impact of neighborhood disadvantage on overt behavior problems during early childhood
Authors: Winslow Emily B. , Shaw Daniel S. 
Published: April 2007

AbstractResearchers have yet to examine the impact of neighborhood disadvantage on early child behavior problems (BPs) longitudinally. We examined the impact of neighborhood disadvantage on overt BPs in a low‐income, urban sample of 281 African American and European American boys followed longitudinally from toddlerhood to school entry. Measures included census data and maternal report of BPs, sociocultural factors, parental criminality, and maternal depressive symptomatology. After controlling for age 2 overt BPs, family selection variables, and residential instability, neighborhood effects on boys' behavior emerged, but only at age 6 and only at the extreme of neighborhood disadvantage (i.e., underclass). Findings suggest boys in underclass neighborhoods are at risk for overt BPs as they make the transition to elementary school. Aggr. Behav. 33:1–13, 2007.© 2007 Wiley‐Liss, Inc.
Registry‐based case–control study of cancer in California firefighters
Authors: Bates Michael N. 
Published: April 2007

AbstractBackgroundThere is no consensus whether firefighters are at increased cancer risk for particular cancers. Previous studies have been small, mostly investigated cancer mortality, and suggested increased risks for brain, bladder, testicular, prostate, thyroid and colo‐rectal cancers, leukemia, and melanoma.MethodsRecords of all male cancers registered in California during 1988–2003 were obtained. Firefighters were identified from occupation and industry text fields. Logistic regression analysis used other cancers as controls.ResultsOf the 804,000 eligible records, 3,659 had firefighting as their occupation. Firefighting was associated with testicular cancer (odds ratio = 1.54, 95% confidence interval: 1.18–2.02), melanoma (1.50, 1.33–1.70), brain cancer (1.35, 1.06–1.72), esophageal cancer (1.48, 1.14–1.91), and prostate cancer (1.22, 1.12–1.33).ConclusionsUse of other‐cancer controls and lack of an occupational history may have biased relative risks towards the null. However, this study, which contained more firefighter cancers than any previous epidemiologic study, produced evidence supporting some prior hypotheses. Am. J. Ind. Med. 50:339–344, 2007. © 2007 Wiley‐Liss, Inc.
Work postures and neck–shoulder pain among orchestra musicians
Authors: Nyman Teresia , Wiktorin Christina , Mulder Marie , Johansson Yvonne Liljeholm 
Published: April 2007

AbstractBackgroundThe purpose of the present study was to identify associations between a work posture with elevated arm position, duration of active playing time, and neck–shoulder pain among orchestra musicians.MethodsIn this study, with a cross‐sectional study design, a total of 235 subjects from 12 Swedish orchestras were categorized into four exposure groups according to arm position and duration of active playing time. Logistic regression analysis was used to calculate odds ratios (OR) for neck–shoulder pain in the four exposure groups.ResultsA higher prevalence of neck–shoulder pain were found in the groups “elevated arm position, <2 hr per workday” [OR 4.15 (1.30–13.22)], and “elevated arm position, >3 hr per workday” [OR 5.35 (1.96–14.62)] compared to the group “neutral arm position, <2 hr per workday”.ConclusionsMusicians working in an elevated arm position (e.g., violinists, violists, flutists, and trumpet players) had a higher prevalence of neck–shoulder pain than those working in a more neutral position. Am. J. Ind. Med. 50:370–376, 2007. © 2007 Wiley‐Liss, Inc.
Association studies testing for risk for late‐onset Alzheimer's disease with common variants in the β‐amyloid precursor protein (APP)
Authors: Nowotny Petra , Simcock Xavier , Bertelsen Sarah , Hinrichs Anthony L. , Kauwe John S.K. , Mayo Kevin , Smemo Scott , Morris John C. , Goate Alison 
Published: April 2007

AbstractLinkage studies have suggested a susceptibility locus for late‐onset Alzheimer's disease (LOAD) on chromosome 21. A functional candidate gene in this region is the β‐amyloid precursor protein (APP) gene. Previously, coding mutations in APP have been associated with early onset Alzheimer's Disease (EOAD). Three copies of APP are associated with AD pathology in Down's syndrome and in EOAD, suggesting that overexpression of APP may be a risk factor for LOAD. Although APP is a strong functional and positional candidate, to date there has been no thorough investigation using a dense map of SNPs across the APP gene. In order to investigate the role of common variation in the APP gene in the risk of LOAD, we genotyped 44 SNPs, spanning 300 kb spanning the entire gene, in a large case‐control series of 738 AD cases and 657 healthy controls. The SNPs showed no association in genotypic or allelic tests, even after stratification for presence or absence of the APOE ϵ4 allele. Haplotype analysis also failed to reveal significant association with any common haplotypes. These results suggest that common variation in the APP gene is not a significant risk factor for LOAD. However, we cannot rule out the possibility that multiple rare variants that increase APP expression or Aβ production might influence the risk for LOAD. © 2007 Wiley‐Liss, Inc.
MECP2 coding sequence and 3′UTR variation in 172 unrelated autistic patients
Authors: Coutinho Ana M. , Oliveira Guiomar , Katz Cécile , Feng Jinong , Yan Jin , Yang Chunmei , Marques Carla , Ataíde Assunção , Miguel Teresa S. , Borges Luís , Almeida Joana , Correia Catarina , Currais António , Bento Celeste , Mota‐Vieira Luísa , Temudo Teresa , Santos Mónica , Maciel Patrícia , Sommer Steve S. , Vicente Astrid M. 
Published: April 2007

AbstractMutations in the coding sequence of the methyl‐CpG‐binding protein 2 gene (MECP2), which cause Rett syndrome (RTT), have been found in male and female autistic subjects without, however, a causal relation having unequivocally been established. In this study, the MECP2 gene was scanned in a Portuguese autistic population, hypothesizing that the phenotypic spectrum of mutations extends beyond the traditional diagnosis of RTT and X‐linked mental retardation, leading to a non‐lethal phenotype in male autistic patients. The coding region, exon–intron boundaries, and the whole 3′UTR were scanned in 172 patients and 143 controls, by Detection of Virtually All Mutations‐SSCP (DOVAM‐S). Exon 1 was sequenced in 103 patients. We report 15 novel variants, not found in controls: one missense, two intronic, and 12 in the 3′UTR (seven in conserved nucleotides). The novel missense change, c.617G > C (p.G206A), was present in one autistic male with severe mental retardation and absence of language, and segregates in his maternal family. This change is located in a highly conserved residue within a region involved in an alternative transcriptional repression pathway, and likely alters the secondary structure of the MeCP2 protein. It is therefore plausible that it leads to a functional modification of MeCP2. MECP2 mRNA levels measured in four patients with 3′UTR conserved changes were below the control range, suggesting an alteration in the stability of the transcripts. Our results suggest that MECP2 can play a role in autism etiology, although very rarely, supporting the notion that MECP2 mutations underlie several neurodevelopmental disorders. © 2007 Wiley‐Liss, Inc.
Low brain‐derived neurotrophic factor (BDNF) levels in serum of Huntington's disease patients
Authors: Ciammola A. , Sassone J. , Cannella M. , Calza S. , Poletti B. , Frati L. , Squitieri F. , Silani V. 
Published: April 2007

AbstractHuntington's disease (HD) is a neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms and by a progressive degeneration of neurons in basal ganglia and in brain cortex. Brain‐derived neurotrophic factor (BDNF) is a pro‐survival factor for striatal neurons. Some evidence implicates a brain BDNF deficiency, related to mutated huntingtin expression, in the selective vulnerability of striatal neurons in HD. We compared BDNF serum levels in 42 patients with HD (range 28–72 years, mean age 51.9 ± 11.5), and 42 age‐matched healthy subjects (range 25–68 years, mean age 48.2 ± 12.5). We evaluated the potential relationship between BDNF serum levels, CAG repeat number (range 40–54, mean 44.8 ± 3.4) and duration of illness (range 6–228 months, mean 103.6 ± 62.1). Serum BDNF levels were significantly lower in patients than in age‐matched healthy subjects. Lower BDNF levels were associated with a longer CAG repeat length and a longer duration of illness. Severity of the illness, as assessed by the Unified Huntington's Disease Rating Scale (UHDRS) motor and cognitive scores, was negatively related to serum BDNF levels. These results in vivo confirm that the huntingtin mutation causes BDNF production to decline and show that the BDNF deficiency is detectable in HD patients' sera. Further studies on a larger sample size should confirm whether BDNF concentrations in patients' serum could be a useful clinical marker related to the patients' disease phenotype. © 2007 Wiley‐Liss, Inc.
Sustained attention and response inhibition in boys with fragile X syndrome: Measures of continuous performance
Authors: Sullivan Kelly , Hatton Deborah D. , Hammer Julie , Sideris John , Hooper Stephen , Ornstein Peter A. , Bailey Donald B. 
Published: April 2007

AbstractSustained attention and response inhibition were examined in boys with full mutation fragile X syndrome (FXS) using adapted visual and auditory continuous performance tests (CPTs). Only 61% of 56 boys with visual CPT data and 54% of 52 boys with auditory data were able to demonstrate sufficient understanding to complete the visual and auditory CPTs, respectively. Mental age (MA) predicted whether boys with FXS were able to demonstrate understanding of the CPTs. The performance of boys with FXS who were able to complete the CPTs was compared to a sample of boys without disabilities matched on MA. Boys with FXS demonstrated similar or smaller declines in sustained attention over task time than their MA‐matched peers on the visual and auditory CPTs, respectively, but consistently demonstrated greater declines in response inhibition over task time than their MA‐matched peers. There were no differences between groups for response time of hits. Higher MAs consistently predicted better sustained attention and response inhibition over task time on the visual and auditory CPTs. Furthermore, boys taking psychotropic medication performed better at the beginning of most tasks, although their performance deteriorated at a faster rate over time, and boys rated as meeting diagnostic criteria for ADHD‐hyperactive type had more difficulty over task time with response inhibition on the auditory CPT. For both boys with FXS and their MA matches, performance was better on the visual CPT than on the auditory CPT though this effect may be attributable to a number of factors other than the modality. © 2007 Wiley‐Liss, Inc.
Investigation of parent‐of‐origin effects in ADHD candidate genes
Authors: Kim Jang Woo , Waldman Irwin D. , Faraone Stephen V. , Biederman Joseph , Doyle Alysa E. , Purcell Shaun , Arbeitman Lori , Fagerness Jesen , Sklar Pamela , Smoller Jordan W. 
Published: April 2007

AbstractAttention deficit hyperactivity disorder (ADHD) is a common early‐onset childhood disorder with a strong genetic component. Results from previous studies have suggested that there may be a parent‐of‐origin effect for ADHD candidate genes. In particular, a recent investigation identified a pattern of paternal over‐transmission of risk alleles for nine ADHD candidate genes. We examined this phenomenon in a sample of 291 trios for five genes previously associated with ADHD (HTR1B, SNAP‐25, DRD5, DAT1, and BDNF). Using a dense map of markers and two analytic methods in this relatively large family‐based sample, we do not find any evidence for significant paternal over‐transmission of risk alleles in these candidate loci. Thus, we conclude that a substantial parent‐of‐origin effect is unlikely for these leading ADHD candidate genes. © 2007 Wiley‐Liss, Inc.
High‐strain deformation of polyethylenes in plane‐strain compression at elevated temperatures
Authors: Lezak E. , Bartczak Z. 
Published: April 2007

AbstractThe deformation and recovery behavior of several polyethylenes and ethylene‐based copolymers with various molecular architectures and a broad range of molecular masses and molecular mass distributions was studied. Because of the differences in the molecular characteristic, this series exhibited a relatively broad range of crystallite sizes and crystallinity levels. The samples were subjected to high strain compression under plane‐strain conditions at the elevated temperature of 80°C. The unloading of the compressed samples led to substantial nonelastic recovery of the strain. The stress–strain and recovery behavior was related to the molecular parameters. The results confirmed the common deformation scheme with four crossover points related to the activation of subsequent deformation mechanisms, as proposed by Strobl. Although the critical strains, related to the activation of deformation of the crystalline component, are invariant, the critical strain of the last point, which is related to the activation of chain disentanglement in the amorphous component, depends on the temperature of deformation. That critical strain decreases from 1.0 to approximately 0.8–0.9 as the temperature of deformation increases from room temperature to 80°C. This shift results from an increase in the chain mobility with increasing temperature, and this makes modification of the molecular network through chain disentanglements easier. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 14–24, 2007
Dispersions of organically modified boehmite particles and a carboxylated styrene–butadiene latix: A simple way to nanocomposites
Authors: Florjańczyk Zbigniew , Dębowski Maciej , Wolak Andrzej , Malesa Monika , Płecha Justyna 
Published: April 2007

AbstractBoehmite particles modified with organic ligands were prepared through the reaction of boehmite with acrylic acid or diethylphosphoric acid (formed in situ from triethyl phosphate). The chemical structures of these particles were determined, and it was shown that they formed stable aqueous dispersions with a particle size lower than 200 nm (average diameter = 40–100 nm, depending on the method of modification) for more than 90% of the population. These nanoparticle dispersions were mixed with carboxylated styrene–butadiene latex, and after water evaporation, homogeneous composites were obtained when the modifier concentration was in the range of 0.5–3 wt %. The mechanical properties of the composites were improved with respect to those of the unmodified rubber (tensile strength up to 200% and elongation at break up to 40%). The modifiers also improved some mechanical properties of rubbers cured with sulfur/N‐cyclohexylbenzothiazole‐2‐sulfenamide/ZnO/stearic acid or ZnO/stearic acid systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 80–88, 2007
Oriented crystallization of crosslinked cis‐1,4‐polybutadiene rubber
Authors: Saijo Kenji , Zhu Yu‐Ping , Hashimoto Takeji , Wasiak Andrzej , Brzostowski Norbert 
Published: April 2007

AbstractCrosslinked cis‐1,4‐polybutadiene (PB) rubber is known to undergo crystallization during mechanical deformation. This article presents small‐angle X‐ray scattering (SAXS), wide‐angle X‐ray scattering (WAXS), and stress‐relaxation studies of the structural development in crosslinked PB samples crystallized under various orientation regimes. The studies are concerned with isothermal crystallization at various temperatures (10 to −50°C) and at constant elongation ratios (1–4.5) and hence with the effects of weak‐to‐intermediate and high orientations on oriented crystallization versus the behavior of unoriented specimens. The results for weak‐to‐intermediate orientations indicate a decrease in the long spacing during crystallization, which is accompanied by an almost constant lamellar thickness as well as a significant time lag between the development of crystallinity revealed by WAXS and SAXS intensity measurements. The SAXS integral intensity shows an overshoot; that is, the intensity reaches a maximum after some crystallization time and then decreases. Stress measured during crystallization with constant elongation ratios shows decay, which depends on the isothermal crystallization temperature and elongation ratio. Although the crystallization in the weak‐to‐intermediate orientations is interpreted on the basis of nucleation growth, the crystallization under high orientations is best interpreted on the basis of spinodal crystallization. The most pronounced feature of structural formation during crystallization under high orientations is an almost constant long period from nearly the beginning of the crystallization, even in a timescale in which other physical quantities such as the WAXS crystallinity, SAXS integral intensity, and stress still change with time, suggesting spinodal‐like crystallization, orientation‐induced instability of molten network chains and their ordering, which involves spinodal‐decomposition‐like segregation of noncrystallizable parts (crosslinked points) and crystallizable parts (linear chains between the crosslinks) of network chains, and subsequent crystallization of crystallizable chains and pinning of the ordering process induced by crystallization. To the best of our knowledge, this work reports for the first time spinodal‐like crystallization on oriented crosslinked polymer melts. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 137–157, 2007