bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrophysiological differences in seropositive and seronegative Lambert–Eaton myasthenic syndrome
Authors: Oh Shin J. , Hatanaka Yuki , Claussen Gwen C. , Sher Emanuele 
Published: October 2006

AbstractIn order to determine whether there is any difference between voltage‐gated calcium‐channel antibody (VGCC‐Ab)–positive and –negative groups in Lambert–Eaton myasthenic syndrome (LEMS), we compared the clinical and electrophysiological features between 13 patients with VGCC‐Ab and 6 VGCC‐Ab–negative patients. No obvious difference was observed in the various clinical features or findings on single‐fiber electromyography between seropositive and seronegative cases. In seropositive cases, the compound muscle action potential (CMAP) amplitude was lower but the increment on post‐exercise facilitation (PEF) and high‐rate stimulation (HRS) was significantly higher than in the seronegative group, indicating that the repetitive nerve stimulation (RNS) test in the seropositive group is more typical of LEMS and more severe. A 100% increment as the diagnostic criterion in the routine RNS test was satisfied in all seropositive cases but in only three seronegative cases, whereas a 60% increment as the diagnostic criterion was found in all seronegative cases. The classic triad (low CMAP amplitude, decrement at low rate of stimulation, and increment at PEF or HRS) of RNS is rare, adding to the difficulty in diagnosing LEMS in the seronegative group, and making a 60% increment criterion more critical for the diagnosis of this disorder. Muscle Nerve, 2006
Electrophysiological study of ephaptic axono‐axonal responses in hemifacial spasm
Authors: Montero J. , Junyent J. , Calopa M. , Povedano M. , Valls‐Sole J. 
Published: October 2006

AbstractOne of the classic features of hemifacial spasm (HFS) is spread of the blink reflex responses to muscles other than the orbicularis oculi. The pathophysiological mechanisms underlying the generation of such abnormal responses include lateral spread of activity between neighboring fibers of the facial nerve and hyperexcitability of facial motoneurons. In this report we present evidence for another mechanism that can contribute to the generation of responses in lower facial muscles resembling the R1 response of the blink reflex. In 13 HFS patients, we studied the responses induced in orbicularis oris by electrical stimuli applied at various sites between the supraorbital and zygomatic areas. We identified responses with two different components: an early and very stable component, with an onset latency ranging from 10.5 to 14.8 ms, and a more irregular longer‐latency component. Displacement of the stimulation site away from the supraorbital nerve and towards the extracranial origin of the facial nerve caused a progressive shortening of response latency. These features indicate that, in our patients, the shortest latency component of the orbicularis oris response was likely generated by antidromic conduction in facial nerve motor axons followed by axono‐axonal activation of the fibers innervating the lower facial muscles. Our results suggest that motor axono‐axonal responses are generated by stimulation of facial nerve terminals in HFS. Muscle Nerve, 2006
A comparison of factors associated with collagen metabolism in different skeletal muscles from dystrophic (mdx) mice: Impact of pirfenidone
Authors: Gosselin Luc E. , Williams Jacqueline E. , Personius Kirkwood , Farkas Gaspar A. 
Published: October 2006

AbstractSkeletal muscles in mdx mice exhibit differential degrees of pathological changes and fibrosis. The purpose of this study was to examine differences in various indices of collagen metabolism in skeletal muscles with widely different functions and activity profiles in mdx mice, and to determine whether pirfenidone would attenuate the development of fibrosis. Mice in the pirfenidone group were orally fed pirfenidone (500 mg/kg) daily for 4 weeks. Marked differences were noted in hydroxyproline concentration between muscles, which could not be explained solely by the level of type I collagen and transforming growth factor‐β1 (TGF‐β1) mRNA. In normal mice, matrix metalloproteinase (MMP)‐2 mRNA was significantly higher in the gastrocnemius than in the diaphragm or genioglossus muscles, suggesting that collagen degradation plays an important role in regulating collagen accretion in skeletal muscle. In mdx mice, the levels of both MMP‐2 and MMP‐9 mRNA were significantly elevated relative to control, although the response was muscle specific. Pirfenidone treatment resulted in a significant reduction in the level of hydroxyproline concentration across all muscles, although the effect was small. Results from this study reveal intrinsic dissimilarities in collagen metabolism between functionally different skeletal muscles. Moreover, the pharmacological use of pirfenidone may be beneficial in preventing fibrosis in muscular dystrophy. Muscle Nerve, 2006
High‐resolution analysis of neuronal growth cone morphology by comparative atomic force and optical microscopy
Authors: Grzywa Emilie L. , Lee Aih Cheun , Lee Gil U. , Suter Daniel M. 
Published: October 2006

AbstractNeuronal growth cones are motile sensory structures at the tip of axons, transducing guidance information into directional movements towards target cells. The morphology and dynamics of neuronal growth cones have been well characterized with optical techniques; however, very little quantitative information is available on the three‐dimensional structure and mechanical properties of distinct subregions. In the present study, we imaged the large Aplysia growth cones after chemical fixation with the atomic force microscope (AFM) and directly compared our data with images acquired by light microscopy methods. Constant force imaging in contact mode in combination with force‐distant measurements revealed an average height of 200 nm for the peripheral (P) domain, 800 nm for the transition (T) zone, and 1200 nm for the central (C) domain, respectively. The AFM images show that the filopodial F‐actin bundles are stiffer than surrounding F‐actin networks. Enlarged filopodia tips are 60 nm higher than the corresponding shafts. Measurements of the mechanical properties of the specific growth cone regions with the AFM revealed that the T zone is stiffer than the P and the C domain. Direct comparison of AFM and optical data acquired by differential interference contrast and fluorescence microscopy revealed a good correlation between these imaging methods. However, the AFM provides height and volume information at higher resolution than fluorescence methods frequently used to estimate the volume of cellular compartments. These findings suggest that AFM measurements on live growth cones will provide a quantitative understanding of how proteins can move between different growth cone regions. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Consistent dynamics suggests tight regulation of biophysical parameters in a small network of bursting neurons
Authors: Szücs Attila , Selverston Allen I. 
Published: October 2006

AbstractThe neuronal firing patterns in the pyloric network of crustaceans are remarkably consistent among animals. Although this characteristic of the pyloric network is well‐known, the biophysical mechanisms underlying the regulation of the systems output are receiving renewed attention. Computer simulations of the pyloric network recently demonstrated that consistent motor output can be achieved from neurons with disparate biophysical parameters among animals. Here we address this hypothesis by pharmacologically manipulating the pyloric network and analyzing the emerging voltage oscillations and firing patterns. Our results show that the pyloric network of the lobster stomatogastric ganglion maintains consistent and regular firing patterns even when entire populations of specific voltage‐gated channels and synaptic receptors are blocked. The variations of temporal parameters used to characterize the burst patterns of the neurons as well as their intraburst spike dynamics do not display statistically significant increase after blocking the transient K‐currents (with 4‐aminopyridine), the glutamatergic inhibitory synapses (with picrotoxin), or the cholinergic synapses (with atropine) in pyloric networks from different animals. These data suggest that in this very compact circuit, the biophysical parameters are cell‐specific and tightly regulated. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Synthesis and characterization of multiblock copolymers composed of poly(5‐methyl‐5‐benzyloxycarbonyl‐1,3‐dioxan‐2‐one) outer blocks and poly(L‐lactide) inner blocks
Authors: Messman Jamie M. , Storey Robson F. 
Published: October 2006

AbstractEthylene glycol (EG) initiated, hydroxyl‐telechelic poly(L‐lactide) (PLLA) was employed as a macroinitiator in the presence of a stannous octoate catalyst in the ring‐opening polymerization of 5‐methyl‐5‐benzyloxycarbonyl‐1,3‐dioxan‐2‐one (MBC) with the goal of creating A–B–A‐type block copolymers having polycarbonate outer blocks and a polyester center block. Because of transesterification reactions involving the PLLA block, multiblock copolymers of the A–(B–A)n–B–A type were actually obtained, where A is poly(5‐methyl‐5‐benzyloxycarbonyl‐1,3‐dioxan‐2‐one), B is PLLA, and n is greater than 0. 1H and 13C NMR spectroscopy of the product copolymers yielded evidence of the multiblock structure and provided the lactide sequence length. For a PLLA macroinitiator with a number‐average molecular weight of 2500 g/mol, the product block copolymer had an n value of 0.8 and an average lactide sequence length (consecutive C6H8O4 units uninterrupted by either an EG or MBC unit) of 6.1. For a PLLA macroinitiator with a number‐average molecular weight of 14,400 g/mol, n was 18, and the average lactide sequence length was 5.0. Additional evidence of the block copolymer architecture was revealed through the retention of PLLA crystallinity as measured by differential scanning calorimetry and wide‐angle X‐ray diffraction. Multiblock copolymers with PLLA crystallinity could be achieved only with isolated PLLA macroinitiators; sequential addition of MBC to high‐conversion L‐lactide polymerizations resulted in excessive randomization, presumably because of residual L‐lactide monomer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6817–6835, 2006
Highly substituted poly(2,3‐diphenyl‐1,4‐phenylenevinylene) derivatives having bulky phenyl and fluorenyl pendant groups: Synthesis, characterization, and electro‐optical properties
Authors: Yang Sheng‐Hsiung , Li Hsing‐Chuan , Chen Chien‐Kai , Hsu Chain‐Shu 
Published: October 2006

AbstractTwo series of poly(2,3‐diphenyl‐1,4‐phenylenevinylene) (DP‐PPV) derivatives containing multiple bulky substituents were synthesized. In the first series, two different groups were incorporated on C‐5,6 positions of the phenylene moiety to increase steric hindrance and to obtain blue‐shifted emissions. In the second series, bulky fluorenyl groups with two hexyl chains on the C‐9 position were introduced on two phenyl pendants to increase the solubility as well as steric hindrance to prevent close packing of the main chain. Polymers with high molecular weights and fine‐tuned electro‐optical properties were obtained by controlling the feed ratio of different monomers during polymerization. The maximum photoluminescent emissions of the thin films are located between 384 and 541 nm. Cyclic voltammetric analysis reveals that the band gaps of these light‐emitting materials are in the range from 2.4 to 3.3 eV. A double‐layer EL device with the configuration of ITO/PEDOT/P4/Ca/Al emitted pure green light with CIE′1931 at (0.24, 0.5). Using copolymer P6 as the emissive layer, the maximum luminescence and current efficiency were both improved when compared with the homopolymer P4. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6738–6749, 2006
Novel amphiphilic graft copolymers bearing hydrophilic poly(acrylic acid) backbones and hydrophobic poly(butyl methacrylate) side chains
Authors: Peng Dan , Lu Guolin , Zhang Sen , Zhang Xiaohuan , Huang Xiaoyu 
Published: October 2006

AbstractA novel amphiphilic graft copolymer consisting of hydrophilic poly(acrylic acid) backbones and hydrophobic poly(butyl methacrylate) side chains was synthesized by successive atom transfer radical polymerization followed by hydrolysis of poly‐(methoxymethyl acrylate) backbone. A grafting‐from strategy was employed for the synthesis of graft copolymers with narrow molecular weight distributions (polydispersity index < 1.40). Hydrophobic side chains were connected to the backbone through stable CC bonds instead of ester connections. Poly(methoxymethyl acrylate) backbone was easily hydrolyzed to poly(acrylic acid) backbone with HCl without affecting the hydrophobic side chains. The amphiphilic graft copolymer could form stable micelles in water. The critical micelle concentration in water was determined by a fluorescence probe technique. The morphology of the micelles was preliminarily explored with transmission electron microscopy and was found to be spheres. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6857–6868, 2006
Phosphorylated copolymers containing pendant, crosslinkable spiro orthoester moieties
Authors: Canadell J. , Hunt B. J. , Cook A. G. , Mantecón A. , Cádiz V. 
Published: October 2006

AbstractThe synthesis of a novel spiro orthoester containing monomer, 1,4,6‐trioxaspiro[4.4]‐2‐nonylmethyl acrylate, is presented. This monomer was polymerized via a free‐radical system to yield the homopolymer and a series of copolymers with phosphorus‐containing comonomers. Diethyl vinyl phosphonate, allyldiphenylphosphine oxide, and diethyl(methacryoyoxymethyl)phosphonate were used in various feed ratios to produce copolymers with different phosphorous concentrations containing crosslinkable spiro orthoester side‐chain units. The crosslinking of the polymers was performed cationically with ytterbium triflate, and in all cases, the expansion of the polymer was observed. Moreover, the incorporation of phosphorus into the copolymers increased the limiting oxygen indices, regardless of the percentage of phosphorus used. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6728–6737, 2006
A mitochondrial‐targeting signal is present in the non‐catalytic domain of the MELK protein kinase
Authors: Chartrain Isabelle , Blot Joëlle , Lerivray Hubert , Guyot Nicolas , Tassan Jean‐Pierre 
Published: October 2006

AbstractMELK is a cell cycle‐regulated protein kinase involved in cell cycle progression, proliferation, tumor growth and mRNA splicing. MELK is localized in the cytoplasm and the nucleus during interphase and at the cell cortex during anaphase and telophase. In this report, we show that the regulatory domain of Xenopus MELK when tagged at its C‐terminus with the green fluorescent protein (GFP), co‐localizes with mitochondria in Xenopus XL2 cells. Significantly, the presence of a mitochondrial targeting signal at the N‐terminus of this fusion protein was predicted by bioinformatics analyses. In agreement with previous reports on mitochondrial proteins, placing the GFP at the N‐terminus inhibited the mitochondrial targeting of the MELK fragment and, furthermore, the regulatory domain without a tag co‐localizes with mitochondria. These results demonstrate the presence of a mitochondrial targeting signal at the N‐terminus of the MC domain of MELK. This mitochondrial targeting signal was also functional in human HeLa cells.
Variation in the catchability of yellow perch (Perca flavescens) in the fisheries of Lake Erie using a Bayesian error-in-variable approach
Authors: Jiao Yan , Reid Kevin , Nudds Tom 
Published: October 2006

AbstractCatch per unit effort (cpue) from fisheries, and abundance or biomass indices from fishery-independent surveys are often used to infer the dynamics of exploited populations. To do this, cpues and survey indices are usually assumed to be proportional to population size or biomass. Four sources of data on the cpue of yellow perch (Perca flavescens) in Lake Erie were available to evaluate this assumption: commercial gillnet and trapnet fisheries, an angling fishery, and a fishery-independent gillnet survey. The relationships between fisheries cpue and population biomass (estimated from an age-structured model), and between fisheries and survey cpues were analysed by error-in-variable (EIV) models because of the absence of independent estimates of population size. Cpues were not proportional to population size, estimated by biomass. Catchabilities varied widely among fisheries (gear types), time period, and areas (management units) within Lake Erie. A spatial EIV model showed that the migrations among management units were considerable. The whole-lake spatial EIV model showed that cpues were not proportional to population size.
THE ASSOCIATIONS BETWEEN SOCIOECONOMIC STATUS, ALLOSTATIC LOAD AND MEASURES OF HEALTH IN OLDER TAIWANESE PERSONS: TAIWAN SOCIAL ENVIRONMENT AND BIOMARKERS OF AGING STUDY
Authors: HU PEIFENG , WAGLE NAVEED , GOLDMAN NOREEN , WEINSTEIN§ MAXINE , SEEMAN TERESA E. 
Published: October 2006

SummaryData from a national representative sample of 1023 elderly and near-elderly Taiwanese were used to explore whether allostatic load is associated with health outcomes and mediates the association between socioeconomic status and health in a non-Western population. The information collected included: demographic characteristics; allostatic load scores; socioeconomic status, measured by education and income; health behaviours; health-related variables, including self-rated health, basic activities of daily living difficulties, instrumental activities of daily living difficulties, and physical activity difficulties. The adjusted prevalent odds ratios of higher allostatic load level were 1·25 (95% CI: 1·00, 1·56) for reporting one level worse in self-rated health and 1·43 (95% CI: 1·14, 1·82) for reporting one more physical activity difficulty. There were significant associations of lower education or less income with worse self-rated health and more difficulties with physical functioning. The associations between education, income and health status are not mediated by the conventional ten-point measure of allostatic load in older Taiwanese adults.
EVIDENCE FOR ASSORTATIVE MATING ON DIGIT RATIO (2D:4D), A BIOMARKER FOR PRENATAL ANDROGEN EXPOSURE
Authors: VORACEK MARTIN , DRESSLER STEFAN G. , MANNING JOHN T. 
Published: October 2006

SummaryThe second-to-fourth digit ratio (2D:4D) presents an anatomical sex difference in humans. On average, men tend to have lower 2D:4D compared with women. There is fairly strong evidence for a role of the 2D:4D ratio as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behaviour. Recently, an accumulating research programme has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced biosocial traits and phenotypes which reach into the domains of ability, behaviour, fertility, health, personality and sexuality. This study investigated the degree of assortative mating (spousal similarity) in a sample of 239 native Austrian couples of parental or grandparental age, all of them having reproduced. Results included: (i) significant spousal correlations of +0·19 and +0·18 for right-hand and left-hand 2D:4D, respectively, and +0·24 for average 2D:4D; (ii) no assortative mating effect on the right-minus-left difference in 2D:4D; (iii) indications consistent with a possible generational decrease of spousal similarity in 2D:4D; (iv) a prevalence of couples with a lower right-hand 2D:4D observed in the husband compared with his wife; and (v) relations of spousal 2D:4D patterns to spousal age differences, such that matings of men with more male-typical trait expressions (namely, a generally low right-hand 2D:4D or showing a lower right-minus-left 2D:4D difference than their wives) implicated larger male-minus-female age differences, i.e. younger wives. It is argued that assortative mating on 2D:4D operates indirectly and may be mediated through the assortment on other, more perceptible, physical traits and psychological phenotypes that entertain associations with 2D:4D and are relevant for courtship and mate choice.
INTELLIGENCE DIFFERENCES BETWEEN EUROPEAN AND ORIENTAL JEWS IN ISRAEL
Authors: DAVID HANNA , LYNN RICHARD 
Published: October 2006

Summary.A number of studies have found that Ashkenazi Jews in the United States have a high average IQ. It has been proposed by Cochran, Hardy and Harpending (2006) that this can be explained by the occupational constraints imposed on the Ashkenazi for many centuries in Europe, when they were largely confined to money-lending. They propose that this selected for the high verbal and mathematical intelligence that has several times been found in American Ashkenazim. The current study investigates how far this theory holds for European and Oriental Jews in Israel. A review of studies shows that Oriental Jews in Israel have an average IQ 14 points lower than that of European (largely Ashkenazi) Jews. It is proposed that this difference can be explained in terms of the Cochran, Hardy and Harpending theory because Oriental Jews were permitted to engage in a much wider range of occupations and hence did not come under the selection pressure to develop the high verbal and mathematical intelligence that was present for Ashkenazim.
Cosmological parameters from combining the Lyman-α forest with CMB, galaxy clustering and SN constraints
Authors: Seljak Uroš , Slosar Anže , McDonald Patrick 
Published: October 2006

We combine the Ly-α forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including three-year WMAP, and supernovae (SN) and galaxy clustering constraints to derive new constraints on cosmological parameters. The existing LYA power spectrum analysis is supplemented by constraints on the mean flux decrement derived using a principle component analysis for quasar continua, which improves the LYA constraints on the linear power. We find some tension between the WMAP3 and LYA power spectrum amplitudes, at the ∼2σ level, which is partially alleviated by the inclusion of other observations: we find σ8= 0.85 ± 0.02 compared to σ8= 0.80 ± 0.03 without LYA. For the slope, we findns= 0.965 ± 0.012. We find no evidence for the running of the spectral index in the combined analysis, dn/dlnk= −(1.5 ± 1.2) × 10−2, in agreement with inflation. The limits on the sum of neutrino masses are significantly improved:at 95% (<0.32 eV at 99.9%). This result, when combined with atmospheric and solar neutrino mixing constraints, requires that the neutrino masses cannot be degenerate,m3/m1>1.3 (95% c.l.). Assuming a thermalized fourth neutrino, we findms<0.26 eV at 95% c.l. and such a neutrino cannot be an explanation for the LSND results. In the limits of massless neutrinos, we obtain the effective number of neutrinosNνeff= 5.3−0.6+0.4−1.7+2.1−2.5+3.8andNνeff= 3.04 is allowed only at 2.4 sigma. The constraint on the dark energy equation of state isw= −1.04 ± 0.06. The constraint on curvature is Ωk= −0.003 ± 0.006. Cosmic strings limits areGμ<2.3 × 10−7at 95% c.l. and correlated isocurvature models are also tightly constrained.