bluuebunny/crossref_metadata_2025 huggingface dataset:
Blind and Sighted Pedestrians' Judgments of Gaps in Traffic at Roundabouts
Authors: Guth David , Ashmead Daniel , Long Richard , Wall Robert , Ponchillia Paul
Published: August 2005

This paper reports two experiments about street crossing under conditions of free flowing traffic, with a focus on modern roundabout intersections. Experiment 1 was conducted at three roundabouts varying in size and traffic volume. Six totally blind and six sighted adults judged whether gaps in traffic were long enough to permit crossing to the median (splitter) island before the next vehicle arrived. Gap distributions and measures of judgment quality are reported. Overall, blind participants were about 2.5 times less likely to make correct judgments than sighted participants, took longer to detect crossable gaps, and were more likely to miss crossable gaps altogether. However, the differences were significant only at the two higher volume roundabouts. In Experiment 2, we evaluated the response of drivers to pedestrians with and without mobility devices (i.e., long canes, dog guides). The experiment was conducted at a single-lane roundabout, a midblock crossing, and a two-way-stop-controlled intersection. Site-specific characteristics appeared to have a greater impact on drivers' yielding than did a mobility device. Actual or potential applications of this research include the development of methods for assessing pedestrian safety and driver behavior as well as identifying intersections that may require modification in order to be accessible to blind pedestrians.
Older Driver Failures of Attention at Intersections: Using Change Blindness Methods to Assess Turn Decision Accuracy
Authors: Caird Jeff K. , Edwards Christopher J. , Creaser Janet I. , Horrey William J.
Published: August 2005

A modified version of the flicker technique to induce change blindness was used to examine the effects of time constraints on decision-making accuracy at intersections on a total of 62 young (18-25 years), middle-aged (26-64 years), young-old (65-73 years), and old-old (74 + years) drivers. Thirty-six intersection photographs were manipulated so that one object (i.e., pedestrian, vehicle, sign, or traffic control device) in the scene would change when the images were alternated for either 5 or 8 s using the modified flicker method. Young and middle-aged drivers made significantly more correct decisions than did young-old and old-old drivers. Logistic regression analysis of the data indicated that age and/or time were significant predictors of decision performance in 14 of the 36 intersections. Actual or potential applications of this research include driving assessment and crash investigation.
The Form of Augmented Force-Feedback Fields and the Efficiency and Satisfaction in Computer-Aided Pointing Tasks
Authors: Keuning Hilde , Monné Tom K. J. , IJsselsteijn Wijnand A. , Houtsma Adrianus J. M.
Published: August 2005

This study investigates operation efficiency and user satisfaction for spatial and temporal shapes of augmented force-feedback fields to be used with computer pointing devices in target acquisition tasks. In an experiment, three different force-field shapes at two different mean force levels were compared, with an electromechanical forcefeedback trackball as control device and with efficiency and user satisfaction as dependent variables. Efficiency was measured by the time required to perform a certain task, and user satisfaction was measured through a subjective rating procedure. Satisfaction results indicate that to a rough approximation, participants can be grouped into those who prefer high and those who prefer low force levels. Members of the former group were most satisfied with force fields with a gradual start and an abrupt ending. This force-field shape also proved to be the most efficient for both groups. When all participants were considered as a single group, none of the effects was found to be statistically significant. A gender effect was also found; in both preference groups women achieved significantly shorter task completion times than men. Actual or potential applications of this research include enabling computer interaction for people prone to repetitive strain injuries and the increment of efficiency and satisfaction in human-computer interaction in general.
Cholinergic Suppression of KCNQ Channel Currents Enhances Excitability of Striatal Medium Spiny Neurons
Authors: Shen Weixing , Hamilton Susan E. , Nathanson Neil M. , Surmeier D. James
Published: August 2005

In response to glutamatergic synaptic drive, striatal medium spiny neuronsin vivotransition to a depolarized “up state” near spike threshold. In the up state, medium spiny neurons either depolarize enough to spike or remain below spike threshold and are silent before returning to the hyperpolarized “down state.” Previous work has suggested that subthreshold K+channel currents were responsible for this dichotomous behavior, but the channels giving rise to the current and the factors determining its engagement have been a mystery. To move toward resolution of these questions, perforated-patch recordings from medium spiny neurons in tissue slices were performed. K+channels with pharmacological and kinetic features of KCNQ channels potently regulated spiking at up-state potentials. Single-cell reverse transcriptase-PCR confirmed the expression of KCNQ2, KCNQ3, and KCNQ5 mRNAs in medium spiny neurons. KCNQ channel currents in these cells were potently reduced by M1muscarinic receptors, because the effects of carbachol were blocked by M1receptor antagonists and lost in neurons lacking M1receptors. Reversal of the modulation was blocked by a phosphoinositol 4-kinase inhibitor, indicating a requirement for phosphotidylinositol 4,5-bisphosphate resynthesis for recovery. Inhibition of protein kinase C reduced the efficacy of the muscarinic modulation. Finally, acceleration of cholinergic interneuron spiking with 4-aminopyridine mimicked the effects of exogenous agonist application. Together, these results show that KCNQ channels are potent regulators of the excitability of medium spiny neurons at up-state potentials, and they are modulated by intrastriatal cholinergic interneurons, providing a mechanistic explanation for variability in spiking during up states seenin vivo.
Dopamine Receptor Stimulation Modulates AMPA Receptor Synaptic Insertion in Prefrontal Cortex Neurons
Authors: Sun Xiu , Zhao Yun , Wolf Marina E.
Published: August 2005

Addiction is believed to involve glutamate-dependent forms of synaptic plasticity that promote the formation of new habits focused on drug seeking. We used primary cultures of rat prefrontal cortex (PFC) neurons to explore mechanisms by which dopamine-releasing psychomotor stimulants such as cocaine and amphetamine influence synaptic plasticity, focusing on AMPA receptor trafficking because of its key role in long-term potentiation (LTP). Brief stimulation of D1dopamine receptors increased surface expression of glutamate receptor 1 (GluR1)-containing AMPA receptors through a protein kinase A-dependent mechanism, by increasing their rate of externalization at extrasynaptic sites. Newly externalized GluR1 remained extrasynaptic under basal conditions but could be translocated into synapses by subsequent NMDA receptor activation. These results suggest that D1receptors may facilitate LTP by increasing the AMPA receptor pool available for synaptic insertion. However, stimulation of D2receptors decreased surface and synaptic GluR1 expression. These findings are discussed in the context of evidence that D1and D2receptors act independently rather than antagonistically in the intact PFC. D1receptor facilitation of AMPA receptor synaptic insertion helps explain D1receptor-dependent facilitation of LTP and learning in the normal brain. Abnormal engagement of this mechanism during unregulated dopamine release may account for maladaptive plasticity after repeated exposure to cocaine or amphetamine.
Using Progenitor Strain Information to Identify Quantitative Trait Nucleotides in Outbred Mice
Authors: Yalcin B , Flint J , Mott R
Published: August 2005

We have developed a fast and economical strategy for dissecting the genetic architecture of quantitative trait loci at a molecular level. The method uses two pieces of information: mapping data from crosses that involve more than two inbred strains and sequence variants in the progenitor strains within the interval containing a quantitative trait locus (QTL). By testing whether the strain distribution pattern in the progenitor strains is consistent with the observed genetic effect of the QTL we can assign a probability that any sequence variant is a quantitative trait nucleotide (QTN). It is not necessary to genotype the animals except at a skeleton of markers; the genotypes at all other polymorphisms are estimated by a multipoint analysis. We apply the method to a 4.8-Mb region on mouse chromosome 1 that contains a QTL influencing anxiety segregating in a heterogeneous stock and show that, under the assumption that a single QTN is present and lies in a region conserved between the human and mouse genomes, it is possible to reduce the number of variants likely to be the quantitative trait nucleotide from many thousands to <20.
Polymorphisms in Cinnamoyl CoA Reductase (CCR) Are Associated With Variation in Microfibril Angle in Eucalyptus spp.
Authors: Thumma Bala R , Nolan Maureen F , Evans Robert , Moran Gavin F
Published: August 2005

Linkage disequilibrium (LD) mapping using natural populations results in higher resolution of marker-trait associations compared to family-based quantitative trait locus (QTL) studies. Depending on the extent of LD, it is possible to identify alleles within candidate genes associated with a trait. Analysis of a natural mutant in Arabidopsis has shown that mutations in cinnamoyl CoA reductase (CCR), a key lignin gene, affect physical properties of the secondary cell wall such as stiffness and strength. Using this gene, we tested whether LD mapping could identify alleles associated with microfibril angle (MFA), a wood quality trait affecting stiffness and strength of wood. We identified 25 common single-nucleotide polymorphism (SNP) markers in the CCR gene in Eucalyptus nitens. Using single-marker and haplotype analyses in 290 trees from a E. nitens natural population, two haplotypes significantly associated with MFA were found. These results were confirmed in two full-sib families of E. nitens and Eucalyptus globulus. In an effort to understand the functional significance of the SNP markers, we sequenced the cDNA clones and identified an alternatively spliced variant from the significant haplotype region. This study demonstrates that LD mapping can be used to identify alleles associated with wood quality traits in natural populations of trees.
Mcm10 Is Required for the Maintenance of Transcriptional Silencing in Saccharomyces cerevisiae
Authors: Liachko Ivan , Tye Bik K
Published: August 2005

Mcm10 is an essential protein that participates in both the initiation and the elongation of DNA replication. In this study we demonstrate a role for Mcm10 in the maintenance of heterochromatic silencing at telomeres and HM loci of budding yeast. Two mcm10 mutants drastically reduce silencing of both URA3 and ADE2 reporter genes integrated into these silent loci. When exposed to α-factor, mcm10 mutant cells display a “shmoo-cluster” phenotype associated with a defect in the maintenance of silencing. In addition, when combined with a defect in the establishment of silent chromatin, mcm10 mutants demonstrate a synergistic defect in HML silencing. Consistent with a direct silencing function, Mcm10p shows a two-hybrid interaction with Sir2p and Sir3p that is destroyed by the mcm10-1 mutation and dependent on the C-terminal 108 amino acids. Tethering GBD-MCM10 to a defective HMR-E silencer is not sufficient to restore silencing. Furthermore, mutations in MCM10 inhibit the ability of GBD-SIR3 to restore silencing when tethered to a defective HMR-E. Suppressor mutations in MCM2, which suppress the temperature sensitivity of mcm10-1, fail to overcome the mcm10-1 silencing defect, suggesting that MCM10's role in transcriptional silencing may be separate from its essential functions in DNA replication.
Maximum-Likelihood Estimation of Coalescence Times in Genealogical Trees
Authors: Meligkotsidou Loukia , Fearnhead Paul
Published: August 2005

We develop a method for maximum-likelihood estimation of coalescence times in genealogical trees, based on population genetics data. For this purpose, a Viterbi-type algorithm is constructed to maximize the joint likelihood of the coalescence times. Marginal confidence intervals for the coalescence times based on the profile likelihoods are also computed. Our method of finding MLEs and calculating C.I.'s appears to be more accurate than alternative numerical maximization methods, and maximum-likelihood inference appears to be more accurate than other existing model-free approaches to estimating coalescent times. We demonstrate the method on two different data sets: human Y chromosome DNA data and fungus DNA data.
Molecular Population Genetics of Accessory Gland Protein Genes and Testis-Expressed Genes in Drosophila mojavensis and D. arizonae
Authors: Wagstaff Bradley J , Begun David J
Published: August 2005

Molecular population genetic investigation of Drosophila male reproductive genes has focused primarily on melanogaster subgroup accessory gland protein genes (Acp's). Consistent with observations from male reproductive genes of numerous taxa, Acp's evolve more rapidly than nonreproductive genes. However, within the Drosophila genus, large data sets from additional types of male reproductive genes and from different species groups are lacking. Here we report findings from a molecular population genetics analysis of male reproductive genes of the repleta group species, Drosophila arizonae and D. mojavensis. We find that Acp's have dramatically higher average pairwise Ka/Ks (0.93) than testis-enriched genes (0.19) and previously reported melanogaster subgroup Acp's (0.42). Overall, 10 of 19 Acp's have Ka/Ks > 1 either in nonpolarized analyses or in at least one lineage of polarized analyses. Of the nine Acp's for which outgroup data were available, average Ka/Ks was considerably higher in D. mojavensis (2.08) than in D. arizonae (0.87). Contrasts of polymorphism and divergence suggest that adaptive protein evolution at Acp's is more common in D. mojavensis than in D. arizonae.
The Relationship of Nucleotide Polymorphism, Recombination Rate and Selection in Wild Tomato Species
Authors: Roselius Kerstin , Stephan Wolfgang , Städler Thomas
Published: August 2005

We analyzed the effects of mating system and recombination rate on single nucleotide polymorphisms using 14 single-copy nuclear loci from single populations of five species of wild tomatoes (Solanum section Lycopersicon). The taxa investigated comprise two self-compatible (SC) and three self-incompatible (SI) species. The observed reduction in nucleotide diversity in the SC populations compared to the SI populations is much stronger than expected under the neutral effects of the mating system on effective population size. Importantly, outgroup sequences available for 11 of the 14 loci yield strong positive correlations between silent nucleotide diversity and silent divergence, indicative of marked among-locus differences in mutation rates and/or selective constraints. Furthermore, using a physical estimate of local recombination rates, we find that silent nucleotide diversity (but not divergence) is positively correlated with recombination rate in two of the SI species. However, this correlation is not nearly as strong as in other well-characterized species (in particular, Drosophila). We propose that nucleotide diversity in Lycopersicon is dominated mainly by differences in neutral mutation rates and/or selective constraints among loci, demographic processes (such as population subdivision), and background selection. In addition, we hypothesize that the soil seed bank plays an important role in the maintenance of the large genetic diversity in the SI species (in particular L. peruvianum).
Bias and Precision in QST Estimates: Problems and Some Solutions
Authors: O'Hara R B , Merilä J
Published: August 2005

Comparison of population differentiation in neutral marker genes and in genes coding quantitative traits by means of FST and QST indexes has become commonplace practice. While the properties and estimation of FST have been the subject of much interest, little is known about the precision and possible bias in QST estimates. Using both simulated and real data, we investigated the precision and bias in QST estimates and various methods of estimating the precision. We found that precision of QST estimates for typical data sets (i.e., with <20 populations) was poor. Of the methods for estimating the precision, a simulation method, a parametric bootstrap, and the Bayesian approach returned the most precise estimates of the confidence intervals.
The Gene doublesex of the Fruit Fly Anastrepha obliqua (Diptera, Tephritidae)
Authors: Ruiz M Fernanda , Stefani Rominy N , Mascarenhas Rodrigo O , Perondini André L P , Selivon Denise , Sánchez Lucas
Published: August 2005

The gene doublesex of Anastrepha obliqua is composed of four instead of the usual six exons. It is transcribed in both sexes and its primary transcript undergoes sex-specific splicing, producing female DsxF and male DsxM proteins, which have in common the amino-terminal region but which differ at the carboxyl-terminal region.
Insertional Polymorphism and Antiquity ofPDR1Retrotransposon Insertions in Pisum Species
Authors: Jing Runchun , Knox Maggie R , Lee Jennifer M , Vershinin Alexander V , Ambrose Michael , Ellis T H Noel , Flavell Andrew J
Published: August 2005

Sequences flanking 73 insertions of the retrotransposon PDR1 have been characterized, together with an additional 270 flanking regions from one side alone, from a diverse collection of Pisum germ plasm. Most of the identified flanking sequences are repetitious DNAs but more than expected (7%) lie within nuclear gene protein-coding regions. The approximate age of 52 of the PDR1 insertions has been determined by measuring sequence divergence among LTR pairs. These data show that PDR1 transpositions occurred within the last 5 MY, with a peak at 1–2.5 MYA. The insertional polymorphism of 68 insertions has been assessed across 47 selected Pisum accessions, representing the diversity of the genus. None of the insertions are fixed, showing that PDR1 insertions can persist in a polymorphic state for millions of years in Pisum. The insertional polymorphism data have been compared with the age estimations to ask what rules control the proliferation of PDR1 insertions in Pisum. Relatively recent insertions (< ∼1.5MYA) tend to be found in small subsets of the Pisum accessions set, “middle-aged” insertions (between ∼1.5 and 2.5 MYA) vary greatly in their occurrence, and older insertions (> ∼2.5 MYA) are mostly found in small subsets of Pisum. Finally, the average age estimate for PDR1 insertions, together with an existing data set for PDR1 retrotransposon SSAP markers, has been used to derive an estimate of the effective population size for Pisum of ∼7.5 × 105.
Genetic Evidence That Drosophila frizzled Controls Planar Cell Polarity and Armadillo Signaling by a Common Mechanism
Authors: Povelones Michael , Howes Rob , Fish Matt , Nusse Roel
Published: August 2005

The frizzled (fz) gene in Drosophila controls two distinct signaling pathways: it directs the planar cell polarization (PCP) of epithelia and it regulates cell fate decisions through Armadillo (Arm) by acting as a receptor for the Wnt protein Wingless (Wg). With the exception of dishevelled (dsh), the genes functioning in these two pathways are distinct. We have taken a genetic approach, based on a series of new and existing fz alleles, for identifying individual amino acids required for PCP or Arm signaling. For each allele, we have attempted to quantify the strength of signaling by phenotypic measurements. For PCP signaling, the defect was measured by counting the number of cells secreting multiple hairs in the wing. We then examined each allele for its ability to participate in Arm signaling by the rescue of fz mutant embryos with maternally provided fz function. For both PCP and Arm signaling we observed a broad range of phenotypes, but for every allele there is a strong correlation between its phenotypic strength in each pathway. Therefore, even though the PCP and Arm signaling pathways are genetically distinct, the set of signaling-defective fz alleles affected both pathways to a similar extent. This suggests that fz controls these two different signaling activities by a common mechanism. In addition, this screen yielded a set of missense mutations that identify amino acids specifically required for fz signaling function.
Quantitative Trait Locus (QTL) Isogenic Recombinant Analysis: A Method for High-Resolution Mapping of QTL Within a Single Population
Authors: Peleman Johan D , Wye Crispin , Zethof Jan , Sørensen Anker P , Verbakel Henk , van Oeveren Jan , Gerats Tom , van der Voort Jeroen Rouppe
Published: August 2005

In the quest for fine mapping quantitative trait loci (QTL) at a subcentimorgan scale, several methods that involve the construction of inbred lines and the generation of large progenies of such inbred lines have been developed (Complex  Trait  Consortium 2003). Here we present an alternative method that significantly speeds up QTL fine mapping by using one segregating population. As a first step, a rough mapping analysis is performed on a small part of the population. Once the QTL have been mapped to a chromosomal interval by standard procedures, a large population of 1000 plants or more is analyzed with markers flanking the defined QTL to select QTL isogenic recombinants (QIRs). QIRs bear a recombination event in the QTL interval of interest, while other QTL have the same homozygous genotype. Only these QIRs are subsequently phenotyped to fine map the QTL. By focusing at an early stage on the informative individuals in the population only, the efforts in population genotyping and phenotyping are significantly reduced as compared to prior methods. The principles of this approach are demonstrated by fine mapping an erucic acid QTL of rapeseed at a subcentimorgan scale.
Acidic Groundwater Discharge and in Situ Egg Survival in Redds of Lake‐Spawning Brook Trout
Authors: Warren Dana R. , Sebestyen Stephen D. , Josephson Daniel C. , Lepak Jesse M. , Kraft Clifford E.
Published: August 2005

Spawning of brook troutSalvelinus fontinalisin lakes occurs over areas of groundwater discharge. The rate and chemistry of groundwater discharge influence brook trout egg survival and reproductive success. While most studies have reported that groundwater discharge in brook trout redds is buffered relative to the surrounding lake water, we documented brook trout spawning over an area of acidic groundwater discharge (pH as low as 4.7) in a lake with circumneutral surface waters (pH > 6.1). A follow‐up experiment that assessed in situ egg survival indicated 0% survival in redds with either low‐pH groundwater or adequate groundwater pH but low groundwater discharge. More than 80% of eggs survived in a reference lake with well‐buffered groundwater and adequate discharge rates. These results suggest that both low pH and low groundwater flow rates may contribute to brook trout egg mortality. Low‐pH groundwater may be a factor to consider in brook trout restoration efforts, especially in lakes where whole‐lake liming has been unsuccessful in reestablishing wild brook trout populations.
Soil Properties Affecting Wheat Yields following Drilling‐Fluid Application
Authors: Bauder T. A. , Barbarick K. A. , Ippolito J. A. , Shanahan J. F. , Ayers P. D.
Published: August 2005

Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (ECe), sodium adsorption ratio (SAR), extractable soil and total straw and grain trace metal and nutrient concentrations, and winter wheat (Triticum aestivumL. ‘TAM 107’) grain yield following water‐based, bentonitic drilling‐fluid application (0–94 Mg ha−1) to field test plots. Three methods of application (normal, splash‐plate, and spreader‐bar) were used to study compaction effects. We measured increasing SAR, ECe, and pH with drilling‐fluid rates, but not to levels detrimental to crop production. Field measurements revealed significantly higher compaction within areas affected by truck travel, but also not enough to affect crop yield. In three of four site years, neither drilling‐fluid rate nor application method affected grain yield. Extractions representing plant availability and plant analyses results indicated that drilling fluid did not significantly increase most trace elements or nutrient concentrations. These results support land application of water‐based bentonitic drilling fluids as an acceptable practice on well‐drained soils using controlled rates.
Orientated crystallization in discontinuous aramid fiber/isotactic polypropylene composites under shear flow conditions
Authors: Larin Boris , Marom Gad , Avila‐Orta Carlos A. , Somani Rajesh H. , Hsiao Benjamin S.
Published: August 2005

Melt blends of short aramid fibers (AF) and isotactic polypropylene (iPP) are subjected to shear at 145°C and the structural evolution and final morphology are examined by in situ synchrotron X‐ray scattering/diffraction and high‐resolution scanning electron microscopy, respectively. The results indicate that the presence of short AFs significantly enhances the crystallization of iPP. It is argued that shear flow in this system exerts a twofold orientating action, namely, on the bulk iPP molecules and on the short AFs. The resultant crystalline morphology reflects the combined effects of crystallization on orientated iPP molecules to facilitate a shish kebab morphology and at the interface of the aligned fibers, to form transcrystallinity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1113–1118, 2005
Effect of temperature on the dispersion properties of polypropylene fibers
Authors: Belal A. E. , Hamza A. A. , Sokkar T. Z. N. , El‐Bakary M. A. , Yassien K. M.
Published: August 2005

A Biolar PI polarizing interference microscope (a Pluta microscope) attached to a special hot stage was used to study the influence of temperature on the dispersion properties of polypropylene fibers with different deniers (6 D and 90 mm, 6 D and 150 mm, and 12 D and 150 mm) over the temperature range of 30–50°C. This study was carried out with a variable‐wavelength interferometry technique. Constant A of Cauchy's dispersion formula and the oscillation and dispersion energies for light vibrating parallel and perpendicularly to the fiber axis were determined at different temperatures. Microinterferograms are given for illustration. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1135–1141, 2005
Synthesis and characterization of sulfonated poly(ethylene terephthalate)/montmorillonite nanocomposites
Authors: Li Yang , Ma Jinghong , Wang Yiming , Liang Borun
Published: August 2005

Sulfonated poly(ethylene terephthalate) (SPET)/montmorillonite nanocomposites were prepared by in situ intercalative polymerization. The microstructure, morphology, and properties of the nanocomposites were studied with wide‐angle X‐ray diffraction, transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, and thermogravimetric analysis. The results indicated that an increase in the SO3Na content improved the dispersion of organically modified montmorillonite in the SPET ionomer matrix, and the dispersed layered silicates in the SPET matrix acted as nucleating agents in SPET crystallization processes and improved the thermal stability of SPET. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1150–1156, 2005
Synthesis and properties of polymer film modified electrodes to detect metal ions
Authors: Rivas Bernabé L. , Pooley S. Amalia , Brovelli Francisco , Pereira Eduardo , Basaez Luis , Osorio Felipe , Moutet Jean‐Claude , Saint–Aman Eric
Published: August 2005

In order to obtain modified polymeric electrodes, polymers were synthesized that are insoluble in water but soluble in common organic solvents and contain different functional groups that are able to coordinate metal ions from low concentrations. Poly(acrylic acid‐co‐styrene), poly(acrylamide‐co‐4‐vinyl pyridine), and poly(styrene‐co‐4‐vinyl pyridine) were synthesized by radical polymerization. The copolymers were characterized by FTIR, 1H‐NMR, 13C‐NMR, scanning electron microscopy, and thermal analysis. The molecular weight and molecular weight distribution were determined by size exclusion chromatography. These complexing polymers were used in the preparation by spin coating of complexing chemically modified electrodes. The polymer film modified electrodes were then tested for the detection of metal ions using the chemical preconcentration and anodic stripping technique. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1192–1197, 2005
Synthesis and characterization of poly(2‐ethylaniline)–poly(styrenesulfonic acid) and poly(o‐phenetidine)–poly(styrenesulfonic acid) complexes
Authors: Lin Der‐Shyu , Yang Sze‐Ming
Published: August 2005

This research focuses on the synthesis of ethyl and ethoxy substituted polyaniline with poly(styrenesulfonic acid) comprising a poly(o‐phenetidine)–poly(styrenesulfonic acid) [P(OP)‐PSSA] and poly(2‐ethylaniline)–poly(styrenesulfonic acid) [P(2‐E)‐PSSA]. The complexes P(OP)‐PSSA and P(2‐E)‐PSSA were prepared by chemical polymerization of monomer (o‐phenetidine, 2‐ethylaniline) with PSSA using an oxidant of ammonium persulfate in 1M HCl solution; polyaniline (PANI), poly(2‐ethylaniline) (P2E), poly(o‐pheneditine) (POP), and polyaniline‐poly(styrenesulfonic acid) (PANI‐PSSA) also were prepared by chemical polymerization to be the reference samples. The products were characterized by IR, VIS, EPR, water solubility, elemental analysis, conductivity, SEM, and TEM. IR spectral studies shown that the structure of P(2‐E)‐PSSA and P(OP)‐PSSA complexes is similar to that of polyaniline. EPR and visible spectra indicate the formation of polarons. The morphology of the blend was investigated by measured SEM and TEM, indicating the conducting component and electrically conductive property of the polymer complexes. The pH value for deprotonation [pH ≥ 9.5 for P(2‐E)‐PSSA and pH ≥ 8.0 for P(OP)‐PSSA] are higher than that of corresponding HCl salts, indicating an intimate interaction between polymer chains. Elemental analysis results show that P(OP)‐PSSA has a nitrogen‐to‐sulfur ratio of ∼52%, larger than that for P(2‐E)‐PSSA, ∼41%. The conductivity of the complexes is around 10−2S/cm, and the solubility of P(2‐E)‐PSSA and P(OP)‐PSSA in water is 2.9 and 1.9 g/L, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1198–1205, 2005
Separation of polyunsaturated fatty acids by selective inclusion in guanidinium‐1,5‐naphthalenedisulfonate‐2‐methoxyethanol host networks
Authors: Voogt Jason N. , Blanch Harvey W.
Published: August 2005

Hydrogen‐bonded networks composed of guanidinium (G) and 1,5‐naphthalenedisulfonate (NDS) have been developed for the selective inclusion and separation of fatty acid esters based on their degree of unsaturation. Porous crystalline networks have been synthesized and include fatty acid esters during crystallization from both methanol and 2‐methoxyethanol. Crystalline networks formed in methanol are selective for the inclusion of saturates in preference to polyunsaturated fatty acid methyl esters, but their applicability is limited by the competing inclusion of the solvent methanol. In 2‐methoxyethanol, a three‐component host structure is formed that provides 4.1 × 4.7 Å2 pores which are also selective for saturated fatty acid ester inclusion. These networks do not suffer from the competing inclusion of the solvent 2‐methoxyethanol as is the case with methanol, and thus complete removal of initial saturated fatty acid 2‐methoxyethyl esters is possible. Binary selectivity experiments on mixtures of the 2‐methoxyethyl esters of saturated stearic acid and the omega‐3 fatty acid α‐linolenic acid reveal that this three‐component network structure provides nearly complete resolution of these two guests in the crystal and filtrate fractions. Separation of the 2‐methoxyethyl esters of α‐linolenic acid from the monounsaturated oleic acid is also possible, although with decreased efficiency in comparison to removal of the saturated fatty acid ester. © 2005 Wiley Periodicals, Inc.
The intelligence community and the war on terror: the role of behavioral science
Authors: Busch Kenneth G. , Weissman Sidney H.
Published: August 2005

The United States intelligence community has been under intense scrutiny from both inside and outside in the aftermath of September 11. Post mortem assessments of intelligence breakdowns may judge the events as more predictable than was in fact the actual reality. In a troubled world, when threats to national security can materialize very quickly, the intelligence community must be able to effectively and swiftly develop and implement plans to prevent further terrorist attacks on the homeland. Numerous scenarios need to be considered for the management of crisis situations. Intelligence actions must make it more difficult for terrorists to strike at their targets. The war on terror must confront a new generation of enemies who threaten to attack the United States with weapons of mass destruction. This essay will focus on the role of behavioral science and how related reforms within the intelligence community could improve its capability to respond to a huge challenge. Copyright © 2005 John Wiley & Sons, Ltd.
Al‐Qaeda's operational evolution: behavioral and organizational perspectives
Authors: Borum Randy , Gelles Michael
Published: August 2005

Al‐Qaeda is widely regarded by the military, law enforcement, diplomatic, and intelligence communities as being the foremost threat to U.S. national security and safety. The nature of this threat, however, has changed since al‐Qaeda first emerged in the late 1980s. This article describes the emergence of a new form of transnational terrorism and details al‐Qaeda's progression from being an organization to an ideological movement. Drawing on a theory of social movements, we analyze its trajectory and the levels of influence. We also offer a behavioral perspective in explaining how al‐Qaeda has adapted as a learning organization with new leadership, tactics, and patterns of recruitment and training. Copyright © 2005 John Wiley & Sons, Ltd.
Terrorism‐related risk management for health care facilities
Authors: Reid Daniel J. , Reid William H.
Published: August 2005

Clinicians should have a basic understanding of the physical and financial risk to mental health facilities related to external threat, such as (but not necessarily limited to) terrorism. Patient care and accessibility to mental health services rest not only on clinical skills, but on a place to practice them and an organized system supported by staff, physical facilities and funding. Clinicians who have some familiarity with the non‐clinical requirements for care are in a position to support non‐clinical staff in preventing care from being interrupted by external threats or events such as terrorist activity, and/or serving at the interface of facility operations and direct clinical care. Readers should note that this article is an introduction to the topic and cannot address all local, state, and national standards for hospital safety, or insurance providers' individual facility requirements. Copyright © 2005 John Wiley & Sons, Ltd.
Unique Nanoscale Morphologies Underpinning Organic Gel‐Phase Materials
Authors: Hirst Andrew R. , Smith David K. , Harrington John P.
Published: August 2005

This study investigates the self‐assembly of simple aliphatic diamines with a dendritic peptide. By controlling the molar ratio of this two‐component system, new nanoscale morphologies were generated. In the presence of relatively long aliphatic chains (C10, C12) a transition from nanoscale fibres to platelets was observed on changing the molar ratio, whereas, for shorter spacer chains (e.g., C9 and C8), interesting and unique morphological changes were observed by low voltage field emission gun scanning electron microscopy (SEM), with “nanosquares” or nanoscale “rosette” structures being formed. Remarkably, these discrete nanoscale structures were able to form sample‐spanning networks capable of supporting a gel‐phase material; whereas, most gels are usually based on fibrillar assemblies. In addition to SEM, the gels were characterised by using thermal measurements and circular dichroism spectroscopy. The length of the diamine spacer and the molar ratio of components controlled the self‐assembly process by modifying the spatial organisation of the dendritic head groups at the molecular level, which is transcribed into the aspect ratio of the self‐assembled state at the microscopic level. Ultimately, this led to diamine‐induced control of the macroscopic material's behaviour. When present in excess, the diamine controlled the observed nanoscale morphology as a consequence of undergoing a dendritically controlled nanocrystallisation process to form a network, an unusual and significant result.
Chemical Modification of the α‐Mannosidase Inhibitor Mannostain A: Synthesis of a Potent Inhibitor 1L‐(1,2,3,5/4)‐5‐Amino‐4‐O‐methyl‐1,2,3,4‐cyclopentanetetrol
Authors: Ogawa Seiichiro , Morikawa Takayuki
Published: August 2005

Demethylthio‐, S‐demethyl‐, and S‐ethyl derivatives of the α‐mannosidase inhibitor, mannostasin A, were synthesized and evaluated for their inhibition of Jack bean α‐mannosidase with the prime objective of elucidating the role of the methylthio group. All methylthio derivatives had significantly lowered inhibitory potentials. However, one mannostatin A analogue with a methoxyl instead of the methylthio group exhibited about twofold enhancement of the activity. The structure and inhibitory activity relationships of mannostatin A and related compounds are discussed in light of our results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Exact family‐based association tests for biallelic data
Authors: Schneiter Kady , Laird Nan , Corcoran Chris
Published: August 2005

Family‐based study designs have an important role in the search for association between disease phenotypes and genetic markers. Unlike traditional case‐control methods, family‐based tests use within‐family data to avoid identification of spurious associations that may result from population admixture. Many family‐based association tests have been proposed to accommodate a variety of ascertainment schemes and patterns of missing data. In this report, we describe exact family‐based association tests for biallelic data. Specifically, we discuss test of the null hypotheses “no linkage and no association” and “linkage, but no association”. These tests, which are valid under various models for inheritance and patterns of missingness, utilize the procedure proposed by Rabinowitz and Laird [2000: Hum Hered 50:211–223] that provides a unified framework for family based association testing (FBAT). The conditioning approach implemented in FBAT makes an exact test conceptually straightforward, but computationally difficult since the minimum sufficient statistics upon which we condition do not have a conventional form. An exact test may be especially critical when accurate computation of the extreme area of the FBAT statistic is needed, such as when the study design necessitates multiple comparisons adjustments. We describe the exact approach as a useful alternative to the aymptotic test and show that the exact tests for biallelic data may be most useful for the recessive disease model. Genet. Epidemiol. 2005 © 2005 Wiley‐Liss, Inc.
Dramatic synergistic anticancer effect of clinically achievable doses of lovastatin and troglitazone
Authors: Yao Chih‐Jung , Lai Gi‐Ming , Chan Chin‐Feng , Cheng Ann‐Lii , Yang Ya‐Yu , Chuang Shuang‐En
Published: August 2005

Lovastatin (an HMG‐CoA reductase inhibitor) and troglitazone (a PPAR‐γ agonist) have been intensively studied prospectively for their application in cancer treatment. However, clinical trials of lovastatin or troglitazone in cancer treatment resulted in only limited responses. To improve their efficacy, lovastatin and troglitazone have, respectively, been tried to combine with other anticancer agents with varied outcomes. In our study, we found a dramatic synergism between lovastatin and troglitazone in anticancer at clinically achievable concentrations. This synergism was found in far majority of cell lines tested including DBTRG 05 MG (glioblastoma) and CL1‐0 (lung). This amazing synergism was accompanied by synergistic modulation of E2F‐1 and p27Kip1, which were reported to mediate the anticancer activities of lovastatin and troglitazone, respectively, and other cell cycle regulating proteins such as CDK2, cyclin A and RB phosphorylation status. With this dramatic combination effect of lovastatin and troglitazone, a promising regimen of cancer therapy may be materialized in the future. © 2005 Wiley‐Liss, Inc.
Soluble MICA in malignant diseases
Authors: Holdenrieder Stefan , Stieber Petra , Peterfi Andrea , Nagel Dorothea , Steinle Alexander , Salih Helmut Rainer
Published: August 2005

The immunoreceptor NKG2D activates natural killer cells and costimulates CD8 T cells. The MHC class I–related MICA molecules are ligands of NKG2D and are expressed on malignant, but not on normal, cells. As NKG2D plays an important role in the immunosurveillance of tumors, studies suggest that release of MICA from cancer cells constitutes an immune escape mechanism that systemically impairs antitumor immunity. Here, we investigated the potential of soluble MICA (sMICA) as a marker in cancer. Analysis of sMICA in sera of 512 individuals revealed significantly (p < 0.0001) higher levels in patients with various malignancies (n = 296, median 161 pg/ml) than in healthy individuals (n = 62, median <30 pg/ml). Patients with benign diseases (n = 154, median 84 pg/ml) exhibited intermediate sMICA levels. In cancer patients, elevated sMICA levels correlated significantly with cancer stage and metastasis (p = 0.015 and p = 0.007, respectively). While release of MICA is thought to impair tumor immunity, determination of sMICA levels may provide useful additional information in the diagnosis and staging of cancer. © 2005 Wiley‐Liss, Inc.
Biodegradable membrane‐covered stent from chitosan‐based polymers
Authors: Thierry Benjamin , Merhi Yahye , Silver Jim , Tabrizian Maryam
Published: August 2005

Membrane‐covered devices could help treat disease of the vasculature such as aneurysm, rupture, and fistulas. They are also investigated to reduce embolic complication associated with revascularization of saphenous vein graft. The aim of this study is to design a clinically applicable biodegradable membrane‐covered stent based on the natural polysaccharide chitosan, which has been developed. The mechanical properties of the membrane is optimized through blending with polyethylene oxide (70:30% Wt CH:PEO). The membrane was able to sustain the mechanical deformation of the supporting self‐expandable metallic stents during its deployment. The membrane was demonstrated to resist physiological transmural pressure (burst pressure resistance >500 mm Hg) and presented a high‐water permeation resistance (1 mL/cm2 min−1 at 120 mmHg). The CH–PEO membrane showed a good hemocompatibility in an ex vivo assay. Heparin and hyaluronan surface complexation with the membrane further reduced platelet adhesion by 50.1 and 63% (p = 0.05). The ability of the membrane‐covered devices to be used as a drug reservoir was investigated using the nitric oxide donor sodium nitroprusside (SNP). SNP‐loaded membranes displayed significantly reduced platelet adhesion. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Angiostatin's molecular mechanism: Aspects of specificity and regulation elucidated
Authors: Wahl Miriam L. , Kenan Daniel J. , Gonzalez‐Gronow Mario , Pizzo Salvatore V.
Published: August 2005

Tumor growth requires the development of new vessels that sprout from pre‐existing normal vessels in a process known as “angiogenesis” [Folkman (1971) N Engl J Med 285:1182–1186]. These new vessels arise from local capillaries, arteries, and veins in response to the release of soluble growth factors from the tumor mass, enabling these tumors to grow beyond the diffusion‐limited size of approximately 2 mm diameter. Angiostatin, a naturally occurring inhibitor of angiogenesis, was discovered based on its ability to block tumor growth in vivo by inhibiting the formation of new tumor blood vessels [O'Reilly et al. (1994a) Cold Spring Harb Symp Quant Biol 59:471–482]. Angiostatin is a proteolytically derived internal fragment of plasminogen and may contain various members of the five plasminogen “kringle” domains, depending on the exact sites of proteolysis. Different forms of angiostatin have measurably different activities, suggesting that much remains to be elucidated about angiostatin biology. A number of groups have sought to identify the native cell surface binding site(s) for angiostatin, resulting in at least five different binding sites proposed for angiostatin on the surface of endothelial cells (EC). This review will consider the data supporting all of the various reported angiostatin binding sites and will focus particular attention on the angiostatin binding protein identified by our group: F1FO ATP synthase. There have been several developments in the quest to elucidate the mechanism of action of angiostatin and the regulation of its receptor. The purpose of this review is to describe the highlights of research on the mechanism of action of angiostatin, its' interaction with ATP synthase on the EC surface, modulators of its activity, and issues that should be explored in future research related to angiostatin and other anti‐angiogenic agents. © 2005 Wiley‐Liss, Inc.
Electronic excitations of green fluorescent proteins: Protonation states of chromophore model compound in solutions
Authors: Xie Daiqian , Zeng Jun
Published: August 2005

Green fluorescent proteins (GFPs) are widely used as tools in biochemistry, cell biology, and molecular genetics due to their unusual optical spectroscopic characteristics. The spectrophotometric and fluorescence properties of GFPs are controlled by the protonation states and possibly cis–trans isomerization of the chromophore (p‐hydroxybenzylideneimidazolinone). In this work, we have investigated electronic structures, liquid structures, and solvent shifts of the three possible protonated states (neutral, anionic, and zwitterionic) and their cis–trans isomerization of a model compound 4′‐hydroxybenzylidene‐2‐methyl‐imidazolin‐5‐one‐3‐acetate (HBMIA) in aqueous solutions. Our calculated results suggest that HBMIA could adopt both cis and trans conformations in a solution, and it exists in three different protonation states depending on the pH conditions. The absorption spectrum observed in neutral solution is thus assigned to the electronic excitations within the neutral form and the cis isomer of the zwitterionic form, while the absorption band at 425 nm in the basic solution is due to the excitations within the anionic form and the trans isomer of the zwitterionic form. Some technical problems related to the computation of electronic excitations within the HBMIA at the anionic state are also discussed. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1487–1496, 2005