bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular infiltration at skin lesions and draining lymph nodes of sheep infested with adultHyalomma anatolicum anatolicumticks
Authors: BOPPANA D. K. V. , WIKEL S. K. , RAJ D. G. , MANOHAR M. B. , LALITHA J.
Published: July 2005

Immunohistochemical analysis of skin and draining lymph nodes of sheep repeatedly infested with the ixodid tickHyalomma anatolicum anatolicumwere studied for different antigen-presenting cells and lymphocyte subpopulations. Infiltration of neutrophils, macrophages and lymphocytes adjacent to the tick bite site were observed. Skin biopsies showed significant increases in dermal infiltration of CD8+and γδ+T cells at 72 h and 8 days after both primary and secondary infestation. Infiltrations of MHC-II DR/DQ decreased at 72 h after tick infestation, whereas significant increases were recorded for 8-day skin biopsies. CD1+cellular infiltrations were observed during secondary infestations at the dermis. Decreased ratios of CD4[ratio ]CD8 T cells and MHC-II[ratio ]CD1 antigen-presenting cells were observed in both infestations compared to healthy skin biopsies. Ratios of αβ[ratio ]γδ T cells increased gradually during infestation compared to uninfested skin. The regional lymph nodes from tick-infested sheep showed an increased CD8+, γδ+T and CD1+cellular infiltration compared to control lymph nodes. CD4+T cells were decreased. There were no significant changes in CD45R+cellular infiltration either at skin lesions or regional lymph nodes.
Population genetics of multi-host parasites – the case for molecular epidemiological studies of Schistosoma japonicum using larval stages from naturally infected hosts
Authors: SHRIVASTAVA J. , GOWER C. M. , BALOLONG E. , WANG T. P. , QIAN B. Z. , WEBSTER J. P.
Published: July 2005

Population genetics of multi-host pathogens offers great potential for the understanding of their complex epidemiology but care must be taken to ensure that the sampling procedure does not bias estimates of population indices. The transfer of material to laboratory passage, in particular, runs the risk of bottlenecking and imposing non-random host-induced selection pressures according to the hosts used in passage. We present a novel technique allowing single-locus microsatellite genotyping of the naturally sampled larval stages, enabling unbiased population genetic studies of the multi-host zoonotic parasite Schistosoma japonicum. The utility of these larval genotyping methods for molecular epidemiological studies are illustrated in results from 3 separate data sets. In the first data set, potential loss of alleles based on the definitive host species used for laboratory maintenance was identified by comparing adult worm populations derived from mice and rabbits infected with cercarial populations originating from the same set of snails. In the second data set, bottlenecking was demonstrated by the loss of alleles in adult worms derived within a single generation of laboratory maintenance compared to their parent field-collected cercarial samples. In the final data set, comparison of miracidia and adult worms recovered from naturally infected animals demonstrated that larval analyses can provide stage-specific epidemiological information and that population genetics of schistosomes can be well described by analysis of larval stages. Our results thus advocate the use of natural life-cycle stages to obtain an accurate and ethical representation of the population genetic structure of S. japonicum and other multi-host pathogens.
Does the addition of cognitive behavioral therapy improve panic disorder treatment outcome relative to medication alone in the primary-care setting?
Authors: CRASKE MICHELLE G. , GOLINELLI DANIELA , STEIN MURRAY B. , ROY-BYRNE PETER , BYSTRITSKY ALEXANDER , SHERBOURNE CATHY
Published: July 2005

Background.Randomized clinical trials indicate a benefit from combining medications with cognitive behavioral therapy (CBT) relative to medication alone for panic disorder. Using an as-treated analysis, we evaluated whether the addition of CBT enhanced outcomes for panic disorder relative to medications alone in the primary-care setting.

Method.Primary-care patients with panic disorder reported on their receipt of CBT and medications over the 3 months following baseline assessment. The degree to which outcomes for those who used anti-panic medications were enhanced by the receipt of at least one component of CBT was analyzed using a propensity score model that took into account observable baseline patient characteristics influencing both treatment selection and outcomes.

Results.The addition of CBT resulted in statistically and clinically significant improvements at 3 months on anxiety sensitivity, social avoidance, and disability. Also, patients receiving CBT in the first 3 months of the study were more improved at 12 months than patients who took medications only during the first 3 months of the study.

Conclusions.The clinical utility of the findings are discussed in terms of the importance of primary-care physicians encouraging their panic disorder patients to receive CBT as well as medications.
The rules versus similarity distinction
Authors: Pothos Emmanuel M.
Published: July 2005

The distinction between rules and similarity is central to our understanding of much of cognitive psychology. Two aspects of existing research have motivated the present work. First, in different cognitive psychology areas we typically see different conceptions of rules and similarity; for example, rules in language appear to be of a different kind compared to rules in categorization. Second, rules processes are typically modeled as separate from similarity ones; for example, in a learning experiment, rules and similarity influences would be described on the basis of separate models. In the present article, I assume that the rules versus similarity distinction can be understood in the same way in learning, reasoning, categorization, and language, and that a unified model for rules and similarity is appropriate. A rules process is considered to be a similarity one where only a single or a small subset of an object's properties are involved. Hence, rules and overall similarity operations are extremes in a single continuum of similarity operations. It is argued that this viewpoint allows adequate coverage of theory and empirical findings in learning, reasoning, categorization, and language, and also a reassessment of the objectives in research on rules versus similarity.
Redefining memory consolidation
Authors: Atienza Mercedes , Cantero Jose L.
Published: July 2005

Based on brain state-dependent behavioral changes, consolidation of sensorimotor memories has been posited to evolve in two different functional stages. Only the second of these stages requires sleep and leads to performance benefits. Recent results, however, suggest that sleep is not always crucial for the expression of delayed behavioral gains but might be critical for enhancing automaticity in the absence of attention, another expression of memory consolidation.
Real rules are conscious
Authors: Cleeremans Axel , Destrebecqz Arnaud
Published: July 2005

In general, we agree with Pothos's claim that similarity and rule knowledge are best viewed as situated on the extreme points of a single representational continuum. However, we contend that a distinction can be made between “rule-like” and “rule-based” knowledge: Rule-based, symbolic knowledge is necessarily conscious when it is applied. Awareness thus provides a useful criterion for distinguishing between sensitivity to functional similarity and knowledge of symbolic rules.
Processing is shaped by multiple tasks: There is more to rules and similarity than Rules-to-Similarity
Authors: Lupyan Gary , Vallabha Gautam
Published: July 2005

We argue that the Rules-Similarity continuum is only a useful formalism for particular, isolated tasks and must rest on the assumption that representations formed during a particular task are independent of other tasks. We show this to be an unrealistic conjecture. We additionally point out that describing categorization as selective weighing and abstracting of features misses the important step of discovering what the possible features are.
Exponentially slow transitions on a Markov chain: the frequency of Calcium Sparks
Authors: HINCH ROBERT , CHAPMAN S. JON
Published: July 2005

Calcium sparks in cardiac muscle cells occur when a cluster of Ca2+ channels open and release Ca2+ from an internal store. A simplified model of Ca2+ sparks has been developed to describe the dynamics of a cluster of channels, which is of the form of a continuous time Markov chain with nearest neighbour transitions and slowly varying jump functions. The chain displays metastability, whereby the probability distribution of the state of the system evolves exponentially slowly, with one of the metastable states occurring at the boundary. An asymptotic technique for analysing the Master equation (a differential-difference equation) associated with these Markov chains is developed using the WKB and projection methods. The method is used to re-derive a known result for a standard class of Markov chains displaying metastability, before being applied to the new class of Markov chains associated with the spark model. The mean first passage time between metastable states is calculated and an expression for the frequency of calcium sparks is derived. All asymptotic results are compared with Monte Carlo simulations.
The preservation of schwa in the converging phonological system of Frenchville (PA) French
Authors: BULLOCK BARBARA E. , GERFEN CHIP
Published: July 2005

The phonological system of the French of Frenchville, Pennsylvania (USA) demonstrates a dramatic case of transfer in the latest (and last) generation of bilingual French–English speakers: the mid front round vowels, [œ] and [ø], have often been replaced by the English rhoticized schwa as found in the word sir. However, French schwa, which is arguably phonetically non-distinct from the mid front round vowels, does not participate fully in this merger. This result is unexpected given both the phonetic identity of schwa and [ø], and the fact that our speakers are not literate in French and, as such, have no access to the differential orthographic representations manifest between schwa and the mid front round vowels. The data argue strongly that schwa is, in some sense, “real” for these speakers. Based on a phonetic analysis of the vowels under consideration, we argue that transfer between two sound systems cannot be perceived as a simple case of phonetic replacement. Instead, transfer or convergence with English must be viewed as a systemic process that preserves contrast in unexpected ways. In the case at hand, the data suggest that the traditional separation between the phonetic and phonological levels of grammar cannot be maintained as each level contributes to both provoking merger and maintaining contrast in bilingual speech.
The role of transfer in language variation and change: Evidence from contact varieties of French
Authors: TREFFERS-DALLER JEANINE , MOUGEON RAYMOND
Published: July 2005

In this Special Issue, the focus is on contact-induced language variation and change in situations of societal bilingualism that involve long-term contact between French and another language. As is well known, when two or more languages are spoken by groups of speakers in the same geographical area, over time, features from one language can be transferred to the other language, especially when the languages in question are unequal in terms of prestige, institutional support and demographic factors. The process that leads to the adoption of such features in the contact languages is generally known as INTERFERENCE or TRANSFER, and these terms are also used to describe the features in question (i.e. the end product of the process of transfer). In this issue we prefer to use the term TRANSFER over the use of the notion INTERFERENCE, as the former has fewer negative connotations than the latter.
Stressreaktivität: Theoretisches Konzept und Messung
Authors: Schulz Peter , Jansen Lars J. , Schlotz Wolff
Published: July 2005

Zusammenfassung. Das Konstrukt Stressreaktivität bezieht sich auf die Disposition einer Person, Belastungen mit schnellen, intensiven und lang andauernden Stressreaktionen zu beantworten. Als Determinanten der Stressreaktivität werden ungünstige Ausprägungen von vier Personmerkmalen angenommen: hohe Besorgnisneigung, negatives Selbstkonzept eigener Fähigkeiten, hohe Erregbarkeit des ZNS und hohe Negative Affektivität. Die hier vorzustellende Stress-Reaktivitäts-Skala (SRS) erhebt neben der generellen auch belastungsspezifische Stressreaktivitäten. Die SRS wurde an einer Stichprobe von N = 975 Personen evaluiert. Trennschärfe- und Reliabilitätskoeffizienten sowie Verteilungseigenschaften erfüllen die teststatistischen Anforderungen. Im Zusammenhang mit der Validierung des Fragebogens werden Befunde zur faktoriellen Validität, Zusammenhänge zu anderen konstruktnahen Persönlichkeitsmerkmalen, Beschwerden, Schlafverhalten, chronischen Erkrankungen und Cortisolreaktionen in einer standardisierten Stresssituation, Ergebnisse zum Einfluss genetischer Faktoren sowie Geschlechtseffekte berichtet. Die Ergebnisse sprechen deutlich für die Validität der SRS. Der Fragebogen eignet sich für die klinische Forschung, Erfassung von individuellen Stressreaktivitäten und zur Evaluation von Anti-Stress-Trainings.
Variations in cutoff latitude during selected solar energetic proton events
Authors: Birch M. J. , Hargreaves J. K. , Senior A. , Bromage B. J. I.
Published: July 2005

Proton count rate measurements were obtained from the polar orbiting environmental satellites POES15 and POES16 during three solar proton events in 2001. From these data the invariant latitude of the cutoff in proton flux was determined at four local times. The satellites sample the edge of the northern polar cap at approximately 0300, 0830, 1230, and 1800 hours local time, covering the early morning, late morning, noon, and evening. During the event of 2 April the cutoff latitude for 35–70 MeV protons was almost constant, showing no more than 1.5° variation with local time. CME impacts occurred during the 24 September and 4 November events, the effects of which were to reduce the cutoff latitudes by between 5° and 8°. The equatorward displacement of the cutoff latitude was found to be strongly correlated with the magnetic storm indices (Dst and SYM‐H). Cutoff latitude prediction formulae are defined. Simulations using the Tsyganenko (2002) model of the magnetosphere are consistent with observations to within 2σ during quiet conditions and weak disturbances.
Continental collision with finite indenter strength: 1. Concept and model formulation
Authors: Robl Jörg , Stüwe Kurt
Published: July 2005

The partitioning of deformation during continental collision is modeled in plan view using a thin viscous sheet simulation. In contrast to many previous models, an indenter is defined here as a zone of finite viscosity contrast to the foreland and aspect ratio. Deformation is enforced by pushing the southern boundary into the model region. It is shown that deformation is equally partitioned between indenter and foreland if the aspect ratio of the indenter is about 1:2, and it is about twice as viscous as the foreland. For higher‐viscosity contrasts between the two plates, the partitioning of deformation between indenter and foreland depends more strongly on Argand number. The process of lateral extrusion is investigated by separating the lateral velocity field into a component that is due to lateral escape and a component that is due to gravitational extensional collapse. It is shown that lateral escape is roughly constant over time and is controlled by the convergence velocity and the obliquity of indentation.
Direct observations of eddy turbulence at a ridge in the Southern Ocean
Authors: Ansorge Isabelle J. , Lutjeharms Johann R. E.
Published: July 2005

Mesoscale turbulence in the ACC is concentrated where the current interacts with prominent bottom topography. An unusual region of high levels of turbulence is found downstream of the South‐West Indian Ridge. It has been inferred that this turbulence consists largely of eddies generated at a fracture zone in the ridge. A dedicated research cruise to the region has now presented data that allow us for the first time to track these eddies and to describe them in hydrographic detail. We show that these eddies are at least 1000 m deep, have a diameter of 250 km, exhibit azimuthal speeds of up to 0.74 ms−1, have subsequent translation speeds of up to 0.09 ms−1 and consist of water masses derived from either north or south of the SAF and APF. Eddies in general are shown to advect in a north‐eastward direction and dissipate before reaching a longitude of 40°E.
Budgeting sinks and sources of CO2 in the coastal ocean: Diversity of ecosystems counts
Authors: Borges A. V. , Delille B. , Frankignoulle M.
Published: July 2005

Air‐water CO2 fluxes were up‐scaled to take into account the latitudinal and ecosystem diversity of the coastal ocean, based on an exhaustive literature survey. Marginal seas at high and temperate latitudes act as sinks of CO2 from the atmosphere, in contrast to subtropical and tropical marginal seas that act as sources of CO2 to the atmosphere. Overall, marginal seas act as a strong sink of CO2 of about −0.45 Pg C yr−1. This sink could be almost fully compensated by the emission of CO2 from the ensemble of near‐shore coastal ecosystems of about 0.40 Pg C yr−1. Although this value is subject to large uncertainty, it stresses the importance of the diversity of ecosystems, in particular near‐shore systems, when integrating CO2 fluxes at global scale in the coastal ocean.
High trace‐velocity infrasound from pulsating auroras at Fairbanks, Alaska
Authors: Wilson Charles R. , Olson John V. , Stenbaek‐Nielsen Hans C.
Published: July 2005

We report here on infrasound signals observed using the infrasound microphone array at Fairbanks, Alaska that are apparently associated with the presence of pulsating auroras near the zenith. We have investigated the frequency domain coherence between the luminous intensity of the pulsating auroras and the high trace‐velocity infrasound received at the earth's surface. Video data of the aurora display from an All‐Sky video camera on the night of December 5, 2003 was compared with the pressure waveform data from the eight‐microphone infrasonic array at Fairbanks. Enhanced coherence between the two signals was observed when a propagation delay time for the infrasound sample with respect to the video data sample was used. The frequency domain coherence was found to be high between the pulsating aurora intensity above the array and the high trace‐velocity infrasound signals at the surface in the pass band from 0.03 to 0.08 Hz. Ray‐tracing studies indicate that such high trace‐velocity infrasound signals originate from sources within 35 km of the zenith above the array for a source height of 110 km. The presence of pulsating aurora patches within this area during the time interval of received infrasound and the high coherence between the video and infrasound data lead us to believe that periodic heating of the atmosphere by pulsating aurora is the actual source of the observed high trace‐velocity infrasound.
Water level changes at an ice‐dammed lake in west Greenland inferred from InSAR data
Authors: Furuya M. , Wahr J. M.
Published: July 2005

We detect ground displacements around an ice‐dammed lake (Lake Tiningnilik) in west Greenland, using ERS1/2 and Envisat radar interferograms. We associate those displacements with draining episodes (jökulhlaups in Icelandic) that occurred in 1993 and 2003. We confirm those episodes in backscatter intensity images. By assuming a 7.5 meter/year increase in water level and using an elastic loading model, we predict a rate and spatial pattern for the deformation that are in good agreement with the observations. By generating digital elevation models from radar interferograms for both the drained and undrained stages, we validate the inferred lake level changes.
Xenon Preconditioning Reduces Brain Damage from Neonatal Asphyxia in Rats
Authors: Ma Daqing , Hossain Mahmuda , Pettet Garry KJ , Luo Yan , Lim Ta , Akimov Stanislav , Sanders Robert D , Franks Nicholas P , Maze Mervyn
Published: July 2005

Xenon attenuates on-going neuronal injury in both in vitro and in vivo models of hypoxic-ischaemic injury when administered during and after the insult. In the present study, we sought to investigate whether the neuroprotective efficacy of xenon can be observed when administered before an insult, referred to as ‘preconditioning’. In a neuronal–glial cell coculture, preexposure to xenon for 2 h caused a concentration-dependent reduction of lactate dehydrogenase release from cells deprived of oxygen and glucose 24 h later; xenon's preconditioning effect was abolished by cycloheximide, a protein synthesis inhibitor. Preconditioning with xenon decreased propidium iodide staining in a hippocampal slice culture model subjected to oxygen and glucose deprivation. In an in vivo model of neonatal asphyxia involving hypoxic–ischaemic injury to 7-day-old rats, preconditioning with xenon reduced infarction size when assessed 7 days after injury. Furthermore, a sustained improvement in neurologic function was also evident 30 days after injury. Phosphorylated cAMP (cyclic adenosine 3′,5′-monophosphate)-response element binding protein (pCREB) was increased by xenon exposure. Also, the prosurvival proteins Bcl-2 and brain-derived neurotrophic factor were upregulated by xenon treatment. These studies provide evidence for xenon's preconditioning effect, which might be caused by a pCREB-regulated synthesis of proteins that promote survival against neuronal injury.
Evidence for hydrogen desorption through both interdimer and intradimer paths from Si(100)-(2×1)
Authors: Shi J. , Chuan Kang H. , Tok E. S. , Zhang J.
Published: July 2005

Despite intensive work there are still controversial issues about desorption and adsorption of hydrogen on Si(100)-(2×1). In particular, the relative importance of the various interdimer- and intradimer-desorption paths is not clear. Nanosecond-pulse-laser desorption data have been used to argue that the 4H interdimer path is important, while data from thermal-desorption time-of-flight measurements suggest a large translationally hot contribution which cannot arise from the 4H interdimer path. The observation of a translationally hot desorption fraction at low to medium coverage can be accounted for by including the 2H interdimer path in quantum dynamical calculations. In this paper we investigate this issue further and present evidence that supports the inclusion of the intradimer path. Specifically, our results show that the intradimer and 3H interdimer paths provide the major contributions to the translationally hot fraction in the desorbate. Our conclusions are based on density-functional calculations of hydrogen translational excitation, mean-field analysis of thermal-desorption experiments over a range of ramp rate, and Monte Carlo simulations of nanosecond-pulse-laser experiments.
NMR relaxation parameters of a Lennard-Jones fluid from molecular-dynamics simulations
Authors: Grivet Jean-Philippe
Published: July 2005

Ensembles of soft spheres or of Lennard-Jones atoms were studied by molecular dynamics at reduced temperatures from 0.8 to 3, and radial distribution functions, diffusion coefficients, and magnetic dipole-dipole correlation functions were measured as functions of system size. The expected relation between the values of the correlation functions at zero lag time and the integrals of the radial distribution was verified for each system. The measured correlation functions were compared with theoretical expressions derived by [Ayant et al., J. Phys. (Paris) 36, 991 (1975)] and by [Hwang and Freed, J. Chem. Phys. 63, 4017 (1975)]. It was shown that, in order to recover the long-time behavior characteristic of diffusion-controlled relaxation processes, the simulation must comprise at least 10 000 particles. By fitting the simulation results to the Hwang-Freed function, independent values of the diffusion coefficient were obtained, similar but not identical to those computed using the Green-Kubo formalism. The spectral densities of the dipole-dipole interaction were computed as Fourier transforms of the correlation functions. These quantities are less sensitive to model imperfections and reproduce quite well the values derived from theory. The dimensionless spin-lattice and spin-spin relaxation rates were derived from the spectral densities. It was shown that the spin-lattice (longitudinal) relaxation rate goes through a maximum as the temperature increases, while the spin-spin (transverse) rate decreases monotonously.
Estimates of electronic coupling for excess electron transfer in DNA
Authors: Voityuk Alexander A.
Published: July 2005

Electronic coupling Vda is one of the key parameters that determine the rate of charge transfer through DNA. While there have been several computational studies of Vda for hole transfer, estimates of electronic couplings for excess electron transfer (ET) in DNA remain unavailable. In the paper, an efficient strategy is established for calculating the ET matrix elements between base pairs in a π stack. Two approaches are considered. First, we employ the diabatic-state (DS) method in which donor and acceptor are represented with radical anions of the canonical base pairs adenine-thymine (AT) and guanine-cytosine (GC). In this approach, similar values of Vda are obtained with the standard 6-31G* and extended 6-31++G** basis sets. Second, the electronic couplings are derived from lowest unoccupied molecular orbitals (LUMOs) of neutral systems by using the generalized Mulliken-Hush or fragment charge methods. Because the radical-anion states of AT and GC are well reproduced by LUMOs of the neutral base pairs calculated without diffuse functions, the estimated values of Vda are in good agreement with the couplings obtained for radical-anion states using the DS method. However, when the calculation of a neutral stack is carried out with diffuse functions, LUMOs of the system exhibit the dipole-bound character and cannot be used for estimating electronic couplings. Our calculations suggest that the ET matrix elements Vda for models containing intrastrand thymine and cytosine bases are essentially larger than the couplings in complexes with interstrand pyrimidine bases. The matrix elements for excess electron transfer are found to be considerably smaller than the corresponding values for hole transfer and to be very responsive to structural changes in a DNA stack.
Irradiation effects on the compensation of semi-insulating GaAs for particle detector applications
Authors: Cavallini Anna , Polenta Laura
Published: July 2005

The distribution of the electric field and its spatial extent are key predictors of the charge collection efficiency of particle detectors. The electric field is strictly related to the electrically active defects, which are significantly modified by irradiation. In this paper we analyze the native and radiation-induced defects and infer the mechanisms controlling the electrical properties of semi-insulating GaAs Schottky diodes. The correlation between the electric-field distribution and deep levels confirms that the compensation mechanisms are mainly due to the donorlike centers and to their enhanced neutralization, which occurs for moderately high electric fields. Moreover, taking into account the charge balance among native and irradiation-induced defects, the active region extent is predicted.
Kramers–Kronig constrained variational analysis of optical spectra
Authors: Kuzmenko A. B.
Published: July 2005

A universal method of extraction of the complex dielectric function ϵ(ω)=ϵ1(ω)+iϵ2(ω) from experimentally accessible optical quantities is developed. The central idea is that ϵ2(ω) is parameterized independently at each node of a properly chosen anchor frequency mesh, while ϵ1(ω) is dynamically coupled to ϵ2(ω) by the Kramers–Kronig (KK) transformation. This approach can be regarded as a limiting case of the multioscillator fitting of spectra, when the number of oscillators is on the order of the number of experimental points. In the case of the normal-incidence reflectivity from a semi-infinite isotropic sample the new method gives essentially the same result as the conventional KK transformation of reflectivity. In contrast to the conventional approaches, the proposed technique is applicable, without readaptation, to virtually all types of linear-response optical measurements, or arbitrary combinations of measurements, such as reflectivity, transmission, ellipsometry, etc., done on different types of samples, including thin films and anisotropic crystals.
Long-range order parameter of single L10-FePd nanoparticle determined by nanobeam electron diffraction: Particle size dependence of the order parameter
Authors: Sato Kazuhisa , Hirotsu Yoshihiko , Mori Hirotaro , Wang Zhouguang , Hirayama Tsukasa
Published: July 2005

The long-range order (LRO) parameter (S) of single isolated L10-FePd nanoparticle was determined by quantitative analysis of nanobeam electron diffraction (NBD) intensities and intensity calculations considering the multiple scattering of electrons. The obtained order parameters of the nanoparticles larger than 8nm are distributed around the mean LRO parameter (S¯=0.79) which was determined by selected area electron diffraction intensity analysis, while the parameters slightly decreased gradually as the particle size decreased below about 8nm (S=0.60–0.73). The low degree of order in very small particles is responsible for the coercivity decrease of the L10 nanoparticles in smaller-sized regions. Quantitative NBD intensity analysis is quite useful for the determination of the LRO parameter of individual L10-FePd single crystalline nanoparticle. Experimental conditions required for NBD analysis are presented in detail and the possible experimental errors of the determined LRO parameters are discussed.
Ionization equilibrium and equation of state of partially ionized hydrogen plasmas: Pseudopotential approach in chemical picture
Authors: Arkhipov Yu. V. , Baimbetov F. B. , Davletov A. E.
Published: July 2005

Starting from the Bogolyubov hierarchy for the equilibrium distribution functions, a novel approach to the chemical model of partially ionized plasmas is proposed. Unlike the ordinary chemical picture it allows one to determine, in a self-consistent manner, both the ionization equilibrium and correlation functions as well. It is shown that the charged and neutral components of the plasma are closely interrelated and, as a consequence, the short-range order formation turns possible. The equation of state of partially ionized hydrogen plasmas is studied and detailed comparison with an exact quantum-mechanical expansion is made. The approach developed is quite analogous to the Debye–Hückel theory of weakly coupled fully ionized plasmas and includes it as a limiting case.
An ultrahigh vacuum dynamic force microscope for high resonance frequency cantilevers
Authors: Kawai Shigeki , Kobayashi Dai , Kitamura Shin-ichi , Meguro Sakae , Kawakatsu Hideki
Published: July 2005

We present the design of an ultrahigh vacuum dynamic force microscope incorporating a heterodyne Doppler interferometer and a superheterodyne circuit with an intermediate frequency of 10.7MHz. The method allowed the use of a low-noise narrow-band analog phase-locked loop with a voltage controlled crystal oscillator for demodulating the frequency shifts caused by the interaction force gradients between the tip and the sample at the intermediate frequency. The system could be used for a conventional cantilever operating in its fundamental and higher modes, as well as for small or stiff cantilevers with high resonance frequency up to 100MHz. A preliminary measurement was demonstrated by the observation of the Si(111)−7×7 reconstructed surface with the second resonance of 1.6MHz with subangstrom amplitudes.
Phylogeny of the Australian freshwater crayfish Cherax destructor-complex (Decapoda : Parastacidae) inferred from four mitochondrial gene regions
Authors: Nguyen Thuy T. T. , Austin Christopher M.
Published: July 2005

The phylogenetic relationships among 32 individuals of Australian freshwater crayfish belonging to the Cherax destructor-complex were investigated using a dataset comprising sequences from four mitochondrial gene regions: the large subunit rRNA (16S rRNA), cytochrome oxidase I (COI), adenosine triphosphatase 6 (ATPase 6), and cytochrome oxidase III (COIII). A total of 1602 bp was obtained, and a combined analysis of the data produced a tree with strong support (bootstrap values 94–100%) for three divergent lineages, verifying the phylogenetic hypotheses of relationships within the C. destructor species-complex suggested in previous studies. Overall, sequences from the 16S rRNA gene showed the least variation compared to those generated from protein coding genes, which presented considerably greater levels of divergence. The level of divergence within C. destructor was found to be greater than that observed in other species of freshwater crayfish, but interspecific variation among species examined in the present study was similar to that reported previously.
Three new genera of Indo-Australian Dermestidae (Coleoptera) and their phylogenetic significance
Authors: Lawrence John F. , Slipinski Adam
Published: July 2005

Three new genera are described, providing valuable new information on the phylogeny and biogeography of the family Dermestidae: Derbyana, gen. nov., containing only D. matthewsi, sp. nov. from north-western Australia; Orphilodes, gen. nov., with three Australian species, O. australis, sp. nov. (type of the genus), O. minor, sp. nov. and O. malleecola, sp. nov.; and Trichodryas, gen. nov., with one described species, T. esoterica sp. nov., from the Malay Peninsula and undescribed species from the Sulu Archipelago, Sabah, Kalimantan and Java. A cladistic analysis is included based on a matrix consisting of the three new genera, exemplar genera representing all major groups of Dermestidae and outgroup exemplars from the families Eucinetidae, Derodontidae, Nosodendridae, Endecatomidae and Bostrichidae. Based on the results, a new supergeneric classification is proposed and compared with those in other recent works on Dermestidae and related groups. Recognised subfamilies and tribes include Orphilinae, Attageninnae, Thorictinae, Dermestinae (Marioutini and Dermestini), Megatominae and Trinodinae (Thylodriini and Trinodini). Trichelodini is suppressed and Hexanodes Blair is removed from synonymy with Trichelodes Carter. Keys are given to adults and larvae of the subfamilies of Dermestidae and the genera of Orphilinae, Dermestinae and Trinodinae.
Paramyosin phosphorylation site disruption affects indirect flight muscle stiffness and power generation in
Drosophila melanogaster
Authors: Liu Hongjun , Miller Mark S. , Swank Douglas M. , Kronert William A. , Maughan David W. , Bernstein Sanford I.
Published: July 2005

The phosphoprotein paramyosin is a major structural component of invertebrate muscle thick filaments. To investigate the importance of paramyosin phosphorylation, we produced transgenic
Drosophila melanogaster
in which one, three, or four phosphorylatable serine residues in the N-terminal nonhelical domain were replaced by alanines. Depending on the residues mutated, transgenic lines were either unaffected or severely flight impaired. Flight-impaired strains had decreases in the most acidic paramyosin isoforms, with a corresponding increase in more basic isoforms. Surprisingly, ultrastructure of indirect flight muscle myofibrils was normal, indicating N-terminal phosphorylation is not important for myofibril assembly. However, mechanical studies of active indirect flight muscle fibers revealed that phosphorylation site mutations reduced elastic and viscous moduli by 21–59% and maximum power output by up to 42%. Significant reductions also occurred under relaxed and rigor conditions, indicating that the phosphorylation-dependent changes are independent of strong crossbridge attachment and likely arise from alterations in thick filament backbone properties. Further, normal crossbridge kinetics were observed, demonstrating that myosin motor function is unaffected in the mutants. We conclude that N-terminal phosphorylation of
Drosophila
paramyosin is essential for optimal force and oscillatory power transduction within the muscle fiber and is key to the high passive stiffness of asynchronous insect flight muscles. Phosphorylation may reinforce interactions between myosin rod domains, enhance thick filament connections to the central M-line of the sarcomere and/or stabilize thick filament interactions with proteins that contribute to fiber stiffness.
Cardiomyocyte hypertrophy and degradation of connexin43 through spatially restricted autocrine/paracrine heparin-binding EGF
Authors: Yoshioka Jun , Prince Robin N. , Huang Hayden , Perkins Scott B. , Cruz Francisco U. , MacGillivray Catherine , Lauffenburger Douglas A. , Lee Richard T.
Published: July 2005

Growth factor signaling can affect tissue remodeling through autocrine/paracrine mechanisms. Recent evidence indicates that EGF receptor transactivation by heparin-binding EGF (HB-EGF) contributes to hypertrophic signaling in cardiomyocytes. Here, we show that HB-EGF operates in a spatially restricted circuit in the extracellular space within the myocardium, revealing the critical nature of the local microenvironment in intercellular signaling. This highly localized microenvironment of HB-EGF signaling was demonstrated with 3D morphology, consistent with predictions from a computational model of EGF signaling. HB-EGF secretion by a given cardiomyocyte in mouse left ventricles led to cellular hypertrophy and reduced expression of connexin43 in the overexpressing cell and in immediately adjacent cells but not in cells farther away. Thus, HB-EGF acts as an autocrine and local paracrine cardiac growth factor that leads to loss of gap junction proteins within a spatially confined microenvironment. These findings demonstrate how cells can coordinate remodeling with their immediate neighboring cells with highly localized extracellular EGF signaling.
Factors that shape seed mass evolution
Authors: Moles Angela T. , Ackerly David D. , Webb Campbell O. , Tweddle John C. , Dickie John B. , Pitman Andy J. , Westoby Mark
Published: July 2005

We used correlated divergence analysis to determine which factors have been most closely associated with changes in seed mass during seed plant evolution. We found that divergences in seed mass have been more consistently associated with divergences in growth form than with divergences in any other variable. This finding is consistent with the strong relationship between seed mass and growth form across present-day species and with the available data from the paleobotanical literature. Divergences in seed mass have also been associated with divergences in latitude, net primary productivity, temperature, precipitation, and leaf area index. However, these environmental variables had much less explanatory power than did plant traits such as seed dispersal syndrome and plant growth form.
The solution structure of the Josephin domain of ataxin-3: Structural determinants for molecular recognition
Authors: Nicastro Giuseppe , Menon Rajesh P. , Masino Laura , Knowles Philip P. , McDonald Neil Q. , Pastore Annalisa
Published: July 2005

The Josephin domain plays an important role in the cellular functions of ataxin-3, the protein responsible for the neurodegenerative Machado–Joseph disease. We have determined the solution structure of Josephin and shown that it belongs to the family of papain-like cysteine proteases, sharing the highest degree of structural similarity with bacterial staphopain. A currently unique structural feature of Josephin is a flexible helical hairpin formed by a 32-residue insertion, which could determine substrate specificity. By using the Josephin structure and the availability of NMR chemical shift assignments, we have mapped the enzyme active site by using the typical cysteine protease inhibitors, transepoxysuccinyl-
l
-eucylamido-4-guanidino-butane (E-64) and [
l
-3-trans-(propylcarbamyl)oxirane-2-carbonyl]-
l
-isoleucyl-
l
-proline (CA-074). We also demonstrate that the specific interaction of Josephin with the ubiquitin-like domain of the ubiquitin- and proteasome-binding factor HHR23B involves complementary exposed hydrophobic surfaces. The structural similarity with other deubiquitinating enzymes suggests a model for the proteolytic enzymatic activity of ataxin-3.
Amyloid ion channels: A common structural link for protein-misfolding disease
Authors: Quist Arjan , Doudevski Ivo , Lin Hai , Azimova Rushana , Ng Douglas , Frangione Blas , Kagan Bruce , Ghiso Jorge , Lal Ratnesh
Published: July 2005

Protein conformational diseases, including Alzheimer's, Huntington's, and Parkinson's diseases, result from protein misfolding, giving a distinct fibrillar feature termed amyloid. Recent studies show that only the globular (not fibrillar) conformation of amyloid proteins is sufficient to induce cellular pathophysiology. However, the 3D structural conformations of these globular structures, a key missing link in designing effective prevention and treatment, remain undefined as of yet. By using atomic force microscopy, circular dichroism, gel electrophoresis, and electrophysiological recordings, we show here that an array of amyloid molecules, including amyloid-β(1–40), α-synuclein, ABri, ADan, serum amyloid A, and amylin undergo supramolecular conformational change. In reconstituted membranes, they form morphologically compatible ion-channel-like structures and elicit single ion-channel currents. These ion channels would destabilize cellular ionic homeostasis and hence induce cell pathophysiology and degeneration in amyloid diseases.
Progressive proximal expansion of the primate X chromosome centromere
Authors: Schueler Mary G. , Dunn John M. , Bird Christine P. , Ross Mark T. , Viggiano Luigi ,   NISC Comparative Sequencing Program∥, Rocchi Mariano , Willard Huntington F. , Green Eric D.
Published: July 2005

Previous studies of the pericentromeric region of the human X chromosome short arm (Xp) revealed an age gradient from ancient DNA that contains expressed genes to recent human-specific DNA at the functional centromere. We analyzed the finished sequence of this human genomic region to investigate its evolutionary history. Phylogenetic analysis of >1,500 alpha-satellite monomers from the region revealed the presence of five physical domains, each containing monomers from a distinct phylogenetic clade. The most distal domain contains long interspersed nucleotide element repeats that were active >35 million years ago, whereas the four proximal domains contain more recently active long interspersed nucleotide element repeats. An out-of-register, unequal recombination (i.e., crossover) detected at the edge of the X chromosome-specific alpha-satellite array (DXZ1) may reflect the most recent of a series of punctuating events during evolution that resulted in a proximal physical expansion of the X centromere. The first 18 kb of this array has 97–99% pairwise identity among all 2-kb repeat units. To perform more detailed evolutionary comparisons, we sequenced the junction between the ancient DNA of Xp and the primate-specific alpha satellite in chimpanzee, gorilla, orangutan, vervet, macaque, and baboon. The striking conservation found in all cases supports the ancestral nature of the alpha satellite at this location. These studies demonstrate that the primate X centromere appears to have evolved through repeated expansion events occurring within the central, active region of centromeric DNA, with the newly added sequences then conferring centromere function.
Foxn4 acts synergistically with Mash1 to specify subtype identity of V2 interneurons in the spinal cord
Authors: Li Shengguo , Misra Kamana , Matise Michael P. , Xiang Mengqing
Published: July 2005

Neuronal subtype diversification is essential for the establishment of functional neural circuits, and yet the molecular events underlying neuronal diversity remain largely to be defined. During spinal neurogenesis, the p2 progenitor domain, unlike others in the ventral spinal cord, gives rise to two intermingled but molecularly distinct subtypes of interneurons, termed V2a and V2b. We show here that the Foxn4 winged helix/forkhead transcription factor is coexpressed with the bHLH factor Mash1 in a subset of p2 progenitors. Loss of
Foxn4
function eliminates
Mash1
expression and V2b neurons and causes a fate-switch to V2a neurons, whereas the absence of
Mash1
displays a similar but less severe phenotype. Overexpression of Foxn4 alone in spinal neural progenitors promotes the V2a fate at the expense of the V2b fate, whereas Mash1 suppresses both the V2a and V2b fates. However, coexpression of both Foxn4 and Mash1 promotes the V2b fate while inhibiting the V2a fate, indicating that Foxn4 cooperates with Mash1 to specify the identity of V2b neurons from bipotential p2 progenitors.
Lack of meal intake compensation following nutritional supplements in hospitalised elderly women
Authors: Boudville Amanda , Bruce David G.
Published: July 2005

Undernutrition contributes to poor clinical outcomes in hospitalised elderly patients but the potential impact of oral nutritional supplements may be reduced by suppressing subsequent food intake. We investigated this possibility in elderly female patients recovering mainly from hip fracture by studying the effect of oral supplements on subsequent food intake during anad libitumbuffet luncheon meal. We tested the effect in seven women by giving the supplement 90 min before the meal and compared energy and macronutrient intake with a control water pre-load condition. A similar study was carried out in another seven women with the supplement or water drink given 30 min beforehand. Both self-rated appetite and energy intake were low in these women. The nutritional supplement did not alter ratings of hunger, fullness or prospective consumption or subsequent energy and macronutrient consumption whether given 90 or 30 min before the meal. There were significant independent correlations between the lack of adequate compensation of energy intake at meals and chronic undernutrition (as assessed by skinfold thickness) and energy intake during the control meal. We conclude that elderly women during the recovery phase after major fractures have low appetites and energy intakes and markedly impaired adjustment of energy intake following liquid oral nutritional supplements. The reasons for this are unknown but are related to anorexia and undernutrition. The consumption of liquid oral supplements given up to 30 min before a meal does not suppress subsequent energy intake from meals.