bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing refractive index changes and differential bending in microcantilever arrays
Authors: Huber François , Lang Hans Peter , Hegner Martin , Despont Michel , Drechsler Ute , Gerber Christoph
Published: August 2008

A new microcantilever array design is investigated comprising eight flexible microcantilevers introducing two solid bars, enabling to subtract contributions from differences in refractive index in an optical laser read out system. Changes in the refractive index do not contribute undesirably to bending signals at picomolar to micromolar DNA or protein concentrations. However, measurements of samples with high salt concentrations or serum are affected, requiring corrections for refractive index artifacts. Moreover, to obtain a deeper understanding of molecular stress formation, the differential curvature of cantilevers is analyzed by positioning the laser spots along the surface of the levers during pH experiments.
Optically induced transport properties of freely suspended semiconductor submicron channels
Authors: Rossler C. , Hof K.-D. , Manus S. , Ludwig S. , Kotthaus J. P. , Simon J. , Holleitner A. W. , Schuh D. , Wegscheider W.
Published: August 2008

We report on optically induced transport phenomena in freely suspended channels containing a two-dimensional electron gas. The submicron devices are fabricated in AlGaAs∕GaAs heterostructures by etching techniques. The photoresponse of the devices can be understood in terms of the combination of photogating and a photodoping effect. The hereby enhanced electronic conductance exhibits a time constant in the range of 1–10ms.
Empirical valence bond model of an SN2 reaction in polar and nonpolar solvents
Authors: Benjamin Ilan
Published: August 2008

A new model for the substitution nucleophilic reaction (SN2) in solution is described using the empirical valence bond (EVB) method. The model includes a generalization to three dimensions of a collinear gas phase EVB model developed by Mathis et al. [J. Mol. Liq. 61, 81 (1994)] and a parametrization of solute-solvent interactions of four different solvents (water, ethanol, chloroform, and carbon tetrachloride). The model is used to compute (in these four solvents) reaction free energy profiles, reaction and solvent dynamics, a two-dimensional reaction/solvent free energy map, as well as a number of other properties that in the past have mostly been estimated.
Theory of dark optical solitons
Authors: Martinez J. C. , Shutler P. M. E. , Toon A.
Published: August 2008

We study the quantum fluctuations about a dark soliton generated in a photon fluid confined in a Kerr-effect nonlinear microcavity. Semiclassical quantization imposes quantization conditions that lend a particle interpretation to the fluctuations. A Bogoliubov–de Gennes analysis complements this view by yielding the single-particle energies and wave functions. The zero modes are found to correspond to the background while the scattering solutions to the notch. We compute the mass associated with the soliton.
Existence and uniqueness theorem for a class of delay differential equations with left and right Caputo fractional derivatives
Authors: Maraaba (Abdeljawad) Thabet , Baleanu Dumitru , Jarad Fahd
Published: August 2008

The existence and uniqueness theorems for functional right-left delay and left-right advanced fractional functional differential equations with bounded delay and advance, respectively, are proved. The continuity with respect to the initial function for these equations is also proved under some Lipschitz kind conditions. The Q-operator is used to transform the delay-type equation to an advanced one and vice versa. An example is given to clarify the results.
Notes on “Ewald summation of electrostatic multipole interactions up to quadrupolar level” [J. Chem. Phys. 119, 7471 (2003)]
Authors: Laino Teodoro , Hutter Jürg
Published: August 2008

In an article [A. Aguado and P. A. Madden, J. Chem. Phys. 119, 7471 (2003)] published in this journal, Ewald summation expressions were derived for the energy, interatomic forces, pressure tensor, electrostatic field, and electrostatic field gradients in simulation system composed of molecules with charges, induced dipoles, and quadrupoles. In this letter we propose an alternative formulation of the reciprocal space terms generalized to higher multipoles, providing, at the same time, a few important corrections for previously published derivations. The present expressions, more compact than the ones proposed in the original work, provide a straightforward approach to implement an Ewald summation scheme for multipole interactions in codes where a standard Ewald summation is already available. A major result of the present derivation is an increase in the computational efficiency compared to the previous implementation of the several different electrostatic terms.
Proof of the identity between the depletion layer thickness and half the average span for an arbitrary polymer chain
Authors: Wang Yanwei , Hansen Flemming Y. , Peters Günther H. , Hassager Ole
Published: August 2008

The confinement analysis from bulk structure (CABS) approach [Y. Wang et al., J. Chem. Phys. 128, 124904 (2008)] is extended to determine the depletion profiles of dilute polymer solutions confined to a slit or near an inert wall. We show that the entire spatial density distributions of any reference point in the polymer chain (such as the center of mass, middle segment, and end segments) can be computed as a function of the confinement size solely based on a single sampling of the configuration space of a polymer chain in bulk. Through a simple analysis based on the CABS approach in the case of a single wall, we prove rigorously that (i) the depletion layer thickness δ is the same no matter which reference point is used to describe the depletion profile and (ii) the value of δ equals half the average span (the mean projection onto a line) of the macromolecule in free solution. Both results hold not only for ideal polymers, as has been noticed before, but also for polymers regardless of details in molecular architecture and configuration statistics.
Effects of dust size distribution on dust acoustic waves in magnetized two-ion-temperature dusty plasmas
Authors: Liu Zong-ming , Duan Wen-shan , He Guang-jun
Published: August 2008

A Zakharov–Kuznetsov (ZK) equation, a modified ZK (mZK) equation, and a coupled ZK (cZK) equation for small but finite amplitude dust acoustic waves in a magnetized two-ion-temperature dusty plasma with dust size distribution have been investigated in this paper. The variations of the linear dispersion relation and group velocity, nonlinear solitary wave amplitude, and width with an arbitrary dust size distribution function are studied numerically. We conclude that they all increase as the total number density of dust grains increases, and they are greater for unusual dusty plasma (the number density of larger dust grains is greater than that of smaller dust grains) than that of usual dusty plasma (the number density of smaller dust grains is greater than that of larger dust grains). It is noted that the frequency of the linear wave increases as the wave number along the magnetic direction increases. Furthermore, the width of the nonlinear waves increases but its amplitude decreases as the wave number along the magnetic direction increases.
Experimental studies of transverse metastable ion velocity distribution functions in the presheath of a weakly collisional argon plasma
Authors: Lee Dongsoo , Hershkowitz Noah , Severn Greg
Published: August 2008

Laser-induced fluorescence measurements of the transverse metastable ion velocity distribution function near a negatively biased plate in a low temperature (Te<1eV), low pressure (p0<1mTorr) dc multi-dipole argon discharge plasma have been made with a diode laser. The metastable argon ions in the 3s23p4(P3)3d4F7∕2 state are found to be characterized by a Maxwellian temperature transverse to the direction normal to the plate. For a neutral pressure of 0.3mTorr, the transverse temperature increases along the presheath from 0.026eV in the bulk plasma to 0.058eV at the presheath sheath boundary.
Nonlinear evolution of kinetic Alfvén waves and the turbulent spectra
Authors: Sharma R. P. , Kumar Sachin , Singh H. D.
Published: August 2008

This paper presents the model equation governing the nonlinear dynamics of the kinetic Alfvén wave (KAW) in the low-β plasmas (β⪡me∕mi) and intermediate-β plasmas (me∕mi⪡β⪡1), where β is thermal pressure to background magnetic pressure ratio, me∕mi is the electron to ion mass ratio. When the ponderomotive and Joule heating nonlinearities are incorporated in the KAW dynamics, the model equation turns out to be a modified nonlinear Schrödinger equation. Numerical solution of this has been obtained when the incident pump KAW is having a small perturbation. Energy exchange between main KAW and perturbation and the resulting filamentary structures of the KAW have been studied. More detail diagnostics reveal that the dynamics of the wave is chaotic. We have presented a simplified model also to explain some of the features of this evolution. Nonlinear saturation of the instability in the form of localized structures and the resulting power spectra of the magnetic field has also been studied.
Cryogenic transimpedance amplifier for micromechanical capacitive sensors
Authors: Antonio D. , Pastoriza H. , Julián P. , Mandolesi P.
Published: August 2008

We developed a cryogenic transimpedance amplifier that works at a broad range of temperatures, from room temperature down to 4 K. The device was realized with a standard complementary metal oxide semiconductor 1.5 μm process. Measurements of current-voltage characteristics, open-loop gain, input referred noise current, and power consumption are presented as a function of temperature. The transimpedance amplifier has been successfully applied to sense the motion of a polysilicon micromechanical oscillator at low temperatures. The whole device is intended to serve as a magnetometer for microscopic superconducting samples.
Low Schottky barrier height for silicides on n-type Si (100) by interfacial selenium segregation during silicidation
Authors: Wong Hoong-Shing , Chan Lap , Samudra Ganesh , Yeo Yee-Chia
Published: August 2008

The electron Schottky barrier height ΦBn modulation for NiSi and PtSi formed on selenium-implanted n-type Si (100) has been experimentally investigated. Selenium (Se) segregation is observed at the silicide/n-Si(100) interface during silicidation process. ΦBn of 83 and 120 meV were achieved for Se segregated NiSi and PtSi on n-Si (100) interfaces, respectively. Contrary to previously reported Fermi level depinning effect in monolayer Se-passivated n-Si (100), the low ΦBn achieved in this work points to metal silicide Fermi level pinning near to conduction band EC of n-Si (100).
Modeling of stochastic broadening in a poloidally diverted discharge with piecewise analytic symplectic mapping flux functions
Authors: Punjabi Alkesh , Ali Halima , Evans Todd , Boozer Allen
Published: August 2008

A highly accurate calculation of the magnetic field line Hamiltonian in DIII-D [J. L. Luxon and L. E. Davis, Fusion Technol. 8, 441 (1985)] is made from piecewise analytic equilibrium fit data for shot 115467 3000ms. The safety factor calculated from this Hamiltonian has a logarithmic singularity at an ideal separatrix. The logarithmic region inside the ideal separatrix contains 2.5% of toroidal flux inside the separatrix. The logarithmic region is symmetric about the separatrix. An area-preserving map for the field line trajectories is obtained in magnetic coordinates from the Hamiltonian equations of motion for the lines and a canonical transformation. This map is used to calculate trajectories of magnetic field lines in DIII-D. The field line Hamiltonian in DIII-D is used as the generating function for the map and to calculate stochastic broadening from field-errors and spatial noise near the separatrix. A very negligible amount (0.03%) of magnetic flux is lost from inside the separatrix due to these nonaxisymmetric fields. It is quite easy to add magnetic perturbations to generating functions and calculate trajectories for maps in magnetic coordinates. However, it is not possible to integrate across the separatrix. It is also difficult to find the physical position corresponding to magnetic coordinates. For open field lines, periodicity in the poloidal angle is assumed, which is not satisfactory. The goal of this paper is to demonstrate the efficacy of the symplectic mapping approach rather than using realistic DIII-D parameters or modeling specific experimental results.
Analytical theory of the probability distribution function of structure formation
Authors: Anderson Johan , Kim Eun-jin
Published: August 2008

The probability distribution function (PDF) tails of the zonal flow structure formation and the PDF tails of momentum flux are computed by incorporating the effect of a shear flow in ion-temperature-gradient (ITG) turbulence. The bipolar vortex soliton (modon) is assumed to be the coherent structure responsible for bursty and intermittent events driving the PDF tails. It is found that stronger zonal flows are generated in ITG turbulence than Hasegawa–Mima turbulence, as well as further from marginal stability. This suggests that although ITG turbulence has a higher level of heat flux, it also more likely generates stronger zonal flows, leading to a self-regulating system. It is also shown that shear flows can significantly reduce the PDF tails of Reynolds stress and structure formation.
A model of transluminal flow of an anti-HIV microbicide vehicle: Combined elastic squeezing and gravitational sliding
Authors: Szeri Andrew J. , Park Su Chan , Verguet Stéphane , Weiss Aaron , Katz David F.
Published: August 2008

Elastohydrodynamic lubrication over soft substrates is of importance in a number of biomedical problems: From lubrication of the eye surface by the tear film, to lubrication of joints by synovial fluid, to lubrication between the pleural surfaces that protect the lungs and other organs. Such flows are also important for the drug delivery functions of vehicles for anti-HIV topical microbicides. These are intended to inhibit transmission into vulnerable mucosa, e.g., in the vagina. First generation prototype microbicides have gel vehicles, which spread after insertion and coat luminal surfaces. Effectiveness derives from potency of the active ingredients and completeness and durability of coating. Delivery vehicle rheology, luminal biomechanical properties, and the force due to gravity influence the coating mechanics. We develop a framework for understanding the relative importance of boundary squeezing and body forces on the extent and speed of the coating that results. A single dimensionless number, independent of viscosity, characterizes the relative influences of squeezing and gravitational acceleration on the shape of spreading in the Newtonian case. A second scale, involving viscosity, determines the spreading rate. In the case of a shear-thinning fluid, the Carreau number also plays a role. Numerical solutions were developed for a range of the dimensionless parameter and compared well with asymptotic theory in the limited case where such results can be obtained. Results were interpreted with respect to trade-offs between wall elasticity, longitudinal forces, bolus viscosity, and bolus volume. These provide initial insights of practical value for formulators of gel delivery vehicles for anti-HIV microbicidal formulations.
Environmental Chemistry: Already having an Impact
Authors: Green Alison
Published: August 2008

Environmental Chemistry is placed in the top 15% of journals in the category of Environmental Sciences, according to Thomson ISI's Journal Citation Report for 2007.
Transcriptome analysis of leaf tissue from Bermudagrass (Cynodon dactylon) using a normalised cDNA library
Authors: Kim Changsoo , Jang Cheol Seong , Kamps Terry L. , Robertson Jon S. , Feltus Frank A. , Paterson Andrew H.
Published: August 2008

A normalised cDNA library was constructed from Bermudagrass to gain insight into the transcriptome of Cynodon dactylon L. A total of 15 588 high-quality expressed sequence tags (ESTs) from the cDNA library were subjected to The Institute for Genomic Research Gene Indices clustering tools to produce a unigene set. A total of 9414 unigenes were obtained from the high-quality ESTs and only 39.6% of the high-quality ESTs were redundant, indicating that the normalisation procedure was effective. A large-scale comparative genomic analysis of the unigenes was carried out using publicly available tools, such as BLAST, InterProScan and Gene Ontology. The unigenes were also subjected to a search for EST-derived simple sequence repeats (EST-SSRs) and conserved-intron scanning primers (CISPs), which are useful as DNA markers. Although the candidate EST-SSRs and CISPs found in the present study need to be empirically tested, they are expected to be useful as DNA markers for many purposes, including comparative genomic studies of grass species, by virtue of their significant similarities to EST sequences from other grasses. Thus, knowledge of Cynodon ESTs will empower turfgrass research by providing homologues for genes that are thought to confer important functions in other plants.
Adjustment of osmotic pressure coupled with change of growth mode in Spirogyra
Authors: Yoshida Katsuhisa , Ohtani Ai , Mimura Tetsuro , Shimmen Teruo
Published: August 2008

Spirogyra living in running water forms a rhizoid which anchors it to the substratum. Rhizoid differentiation can be induced in the laboratory by severing algal filaments. The terminal cell changes the growth mode from diffuse growth to tip growth, and finally differentiates to be a rhizoid. We found that the intracellular osmolarity of the rhizoid was significantly lower than that of other interjacent cells which did not form rhizoids. The decrease in the intracellular osmolarity began before the start of tip growth. TEA, a K+ channel blocker, inhibited the decrease in the intracellular osmolarity of the terminal cells; increase in the external K+ also inhibited this. It was suggested that K+ efflux through K+ channel is involved in the adjustment of osmotic pressure. When the adjustment of osmotic pressure was inhibited, tip growth did not start, inevitably, no rhizoid was formed. In Spirogyra sp. which was unable to form rhizoids, the terminal cell did not show the adjustment of osmotic pressure. Thus, this adjustment seems to be intimately coupled with the rhizoid differentiation. Possible roles of the adjustment of osmotic pressure in rhizoid differentiation are discussed.
Calmodulin dynamically regulates the trafficking of the metabotropic glutamate receptor mGluR5
Authors: Lee Jeong Ho , Lee Jinu , Choi Kyu Yeong , Hepp Regine , Lee Jae-Youn , Lim Mi Kyung , Chatani-Hinze Mayumi , Roche Paul A. , Kim Dong Goo , Ahn Young Soo , Kim Chul Hoon , Roche Katherine W.
Published: August 2008

Metabotropic glutamate receptors (mGluRs) 1–8 are G protein-coupled receptors (GPCRs) that modulate excitatory neurotransmission, neurotransmitter release, and synaptic plasticity. PKC regulates many aspects of mGluR function, including protein–protein interactions, Ca
2+
signaling, and receptor desensitization. However, the mechanisms by which PKC regulates mGluR function are poorly understood. We have now identified calmodulin (CaM) as a dynamic regulator of mGluR5 trafficking. We show that the major PKC phosphorylation site on the intracellular C terminus of mGluR5 is serine 901 (S901), and phosphorylation of this residue is up-regulated in response to both receptor and PKC activation. In addition, S901 phosphorylation inhibits mGluR5 binding to CaM, decreasing mGluR5 surface expression. Furthermore, blocking PKC phosphorylation of mGluR5 on S901 dramatically affects mGluR5 signaling by prolonging Ca
2+
oscillations. Thus, our data demonstrate that mGluR5 activation triggers phosphorylation of S901, thereby directly linking PKC phosphorylation, CaM binding, receptor trafficking, and downstream signaling.
Extreme diversity of tropical parasitoid wasps exposed by iterative integration of natural history, DNA barcoding, morphology, and collections
Authors: Smith M. Alex , Rodriguez Josephine J. , Whitfield James B. , Deans Andrew R. , Janzen Daniel H. , Hallwachs Winnie , Hebert Paul D. N.
Published: August 2008

We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservación Guanacaste (ACG) in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies
Apanteles leucostigmus
. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
Biological evaluation of Michigan's non-wadeable rivers using macroinvertebrates
Authors: Wessell Kelly J. , Merritt Richard W. , Wilhelm Jennifer G.O. , Allan J. David , Cummins Kenneth W. , Uzarski Donald G.
Published: August 2008

Non-wadeable rivers are relatively understudied compared to smaller, wadeable streams. Currently, protocols exist in most states, including Michigan, to evaluate the ecological condition of wadeable streams, but few protocols exist for larger, non-wadeable rivers. The goal of this research was to develop a multimetric index of biological integrity for Michigan's non-wadeable rivers, and we sampled 28 unique river reaches in Michigan that encompassed a wide range of human impacts and ecological conditions. In each reach, we collected physical, chemical, and macroinvertebrate samples. Using several techniques to eliminate redundancy among metrics and identify those biological attributes that correlated with anthropogenic influences, we developed a useful protocol that will allow the rapid bioassessment of such rivers in Michigan. When used together with the Non-wadeable Habitat Index, the Non-wadeable Index of Biotic Integrity (NW-IBI) will allow objective evaluation of non-wadeable rivers in Michigan.
Freshwater fishes, fisheries, and habitat prospects of Nepal
Authors: Sharma Chhatra M.
Published: August 2008

This paper deals with the status of fish, fisheries, and habitats in Nepal. Being a landlocked country, it has only freshwater habitats covering an area of 745,000 hectares (5% of the total area) that includes rivers, lakes, ponds, wetlands, reservoirs, and irrigated rice fields. It has a diverse fish species totaling 200 fish species, of which 191 are indigenous and nine exotic. Thirty-four fish species were categorized as threatened (IUCN categories), requiring due attention for the conservation. Legal protection is recommended for ten fish species in the endangered and vulnerable categories. Fish harvests are mainly based on the subsistence fish farming, and from capture fisheries. National fish production in the year 2000/01 was 33,270 metric tons. Lowland areas are most suitable for aquaculture, whereas hill streams have a great attraction for sport fishing. Some destructive fishing methods are in use in capture fishery, e.g., electric fishing, explosives and poisons. In Nepal, some of the major fish habitats are in protected conservation areas, e.g., national parks and World Ramsar Sites. However, proper consideration has not been given for fish habitat management. The national plan includes a fisheries/aquaculture sub sector mainly for supplying animal protein, and for generating self-employment and income of small-scale farmers. The number of people involved in the capture fisheries has increased and included 142,000 men and 223,000 women in the year 2000/01. At the same time, commercial trout farming in the private sector has increased. Long-term perspectives in the fields of aquatic ecology, genetics, biotechnology and ecotoxicology are essential to enhance the fish and fisheries science in the country.

[Supplementary material is available for this article. Go to the publisher's online edition of Aquatic Ecosystem Health & Management for the following free supplemental resource: an appendix containing a checklist of freshwater fishes of Nepal.]
Correlation Between Energy Transfer Rate and Atomization Energy of Some Trinitro Aromatic Explosive Molecules
Authors: Ge Su-hong , Cheng Xin-lu , Liu Zheng-lai , Yang Xiang-dong , Dong Fang-fang
Published: August 2008

An assumptive theoretical relationship is suggested to describe the property of molecular atomization energy and energy transfer rate in the initiation of explosions. To investigate the relationship between atomization energy and energy transfer rate, the number of doorway modes of explosives is estimated by the theory of Dlott and Fayer in which the rate is proportional to the number of normal mode vibrations. It was evaluated frequencies of normal mode vibrations of eight molecules by means of density functional theory (DFT) at the b3p86/6-31G(d,p) level. It is found that the number of doorway modes shows a linear correlation to the atomization energies of the molecules, which were also calculated by means of the same method. A mechanism of this correlation is discussed. It is also noted that in those explosives with similar molecular structure and molecular weight, the correlation between the atomization energy and the number of doorway modes is higher.
In situInvestigation on Layer-by-Layer Deposition of Polyelectrolytes by Quartz Crystal Microbalance
Authors: Yan Yun-feng , Liu Guang-ming , Tang Ye-cang , Zhang Guang-zhao
Published: August 2008

The effect of salt concentration on layer-by-layer deposition of poly(sodium 4-styrene sulfonate) (PSSS)/poly(vinylbenzyl trimethylammonium chloride) (PVTC) was investigated by use of quartz crystal microbalance with dissipation (QCM-D). The changes in frequency and dissipation demonstrate that the addition of NaCl leads the thickness of PSSS/PVTC multilayer to increase. The deposition of PSSS/PVTC is dominated by surface charge overcompensation level at lower salt concentrations. However, it is mainly determined by the interpenetration of polyelectrolytes at a higher salt concentration, as reflected in the oscillation of dissipation change.
CLASP Modulates Microtubule-Cortex Interaction during Self-Organization of Acentrosomal Microtubules
Authors: Ambrose J. Christian , Wasteneys Geoffrey O.
Published: August 2008

CLASP proteins associate with either the plus ends or sidewalls of microtubules depending on the subcellular location and cell type. In plant cells, CLASP's distribution along the full length of microtubules corresponds with the uniform anchorage of microtubules to the cell cortex. Using live cell imaging, we show here that loss of CLASP in Arabidopsis thaliana results in partial detachment of microtubules from the cortex. The detached portions undergo extensive waving, distortion, and changes in orientation, particularly when exposed to the forces of cytoplasmic streaming. These deviations from the normal linear polymerization trajectories increase the likelihood of intermicrotubule encounters that are favorable for subsequent bundle formation. Consistent with this, cortical microtubules in clasp-1 leaf epidermal cells are hyper-parallel. On the basis of these data, we identify a novel mechanism where modulation of CLASP activity governs microtubule-cortex attachment, thereby contributing to self-organization of cortical microtubules.
On the use of tagging data in statistical multispecies multi-area models of marine populations
Authors: Hannesson Sigurdur , Jakobsdottir Audbjorg , Begley James , Taylor Lorna , Stefansson Gunnar
Published: August 2008

Hannesson, S., Jakobsdottir, A., Begley, J., Taylor, L., and Stefansson, G. 2008. On the use of tagging data in statistical multispecies multi-area models of marine populations. – ICES Journal of Marine Science, 65: 1762–1772. The use of multispecies models of marine stocks along with recognition of the importance of temporal differences in spatial overlap has resulted in migration rates playing an increasingly important role in models of fish stocks. Moreover, traditional estimates of growth based on samples from fishing gear are confounded with the selection pattern, which is exacerbated when multispecies issues are considered. For these and other reasons, there is a need to include explicit tagging data as a component of fisheries models. A statistical multispecies multi-area framework has been extended to predict tag returns and subsequently to incorporate tagging data in likelihood components to be used when estimating migration rates. The information content of such data is not clear a priori, but simulations indicate the point estimates to be quite reasonable. A bootstrap method is proposed, based on bootstrapping entire tagging experiments (rather than individual fish). The resulting bootstrapped uncertainty estimates are generally applicable and are found to be close to the true values in the simulated examples.
Why do fiddler crabs build chimneys?
Authors: Slatyer R.A , Fok E.S.Y , Hocking R , Backwell P.R.Y
Published: August 2008

Chimneys are mud mounds built by fiddler crabs that encircle the entrance to their burrow. Their function in many species is unknown. In
Uca capricornis
, crabs of both sexes and all sizes build chimneys, but females do so disproportionately more often. There are no differences in the immediate physical or social environments between crabs with and without a chimney. Chimney owners spend less time feeding and more time underground than non-owners. We show experimentally that burrows with a chimney are less likely to be located by an intruder. It is possible that some crabs construct chimneys around their burrow to conceal the entrance and reduce the risk of losing it to an intruder.
Spondylodiscitis and paraspinal abscess caused by β-haemolytic group G streptococci spreading from infected leg ulcers
Authors: Lestin Franka , Mann Sascha , Podbielski Andreas
Published: August 2008

We report a case of spondylodiscitis due toStreptococcus dysgalactiaesubsp.equisimilisspreading from infected leg ulcers. The route of infection could be unequivocally demonstrated by culturing identical isolates from leg wounds, blood culture and intra-surgery specimens from the spine. The present case illustrates the pathogenic potential of group G streptococci also for non-diabetic adults.
Novel hypertonic saline–sodium hydroxide (HS–SH) method for decontamination and concentration of sputum samples for Mycobacterium tuberculosis microscopy and culture
Authors: Ganoza Christian A. , Ricaldi Jessica N. , Chauca José , Rojas Gabriel , Munayco César , Agapito Juan , Palomino Juan Carlos , Guerra Humberto
Published: August 2008

This study evaluated a new decontamination and concentration (DC) method for sputum microscopy and culture. Sputum samples from patients with suspected pulmonary tuberculosis (TB) (n=106) were tested using the proposed hypertonic saline–sodium hydroxide (HS–SH) DC method, the recommended N-acetyl-l-cysteine–sodium citrate–sodium hydroxide (NALC-NaOH) DC method and unconcentrated direct smear (Ziehl–Neelsen) techniques for the presence of mycobacteria using Löwenstein-Jensen culture and light microscopy. Of 94 valid specimens, 21 (22.3 %) were positive in culture and were further characterized as Mycobacterium tuberculosis. The sensitivity for acid-fast bacilli (AFB) smears was increased from 28.6 % using the direct method to 71.4 % (HS–SH) and 66.7 % (NALC-NaOH) using DC methods. Both concentration techniques were highly comparable for culture (kappa=0.794) and smear (kappa=0.631) for AFB. Thus the proposed HS–SH DC method improved the sensitivity of AFB microscopy compared with a routine unconcentrated direct smear; its performance was comparable to that of the NALC-NaOH DC method for AFB smears and culture, but it was methodologically simpler and less expensive, making it a promising candidate for evaluation by national TB control programmes in developing countries.
First case of post-endoscopic retrograde cholangiopancreatography bacteraemia caused by Acinetobacter ursingii in a patient with choledocholithiasis and cholangitis
Authors: de la Tabla Ducasse Victoria Ortiz , González Coral Martín , Sáez-Nieto Juan A. , Gutiérrez Félix
Published: August 2008

We describe what we believe to be the first case of biliary sepsis caused by Acinetobacter ursingii. The patient was a healthy woman with no comorbidities who presented with choledocholithiasis and cholangitis. The performance of an endoscopic cholangiopancreatography was the trigger for A. ursingii bacteraemia. This report highlights the inadequacies of conventional phenotypic tests usually available in clinical microbiology laboratories for the identification of Acinetobacter species.
Effect of triclosan on the formation of crystalline biofilms by mixed communities of urinary tract pathogens on urinary catheters
Authors: Williams Gareth J. , Stickler David J.
Published: August 2008

The crystalline bacterial biofilms that encrust Foley catheters compromise the care of many elderly and disabled patients. The aim of this study was to examine whether the biocide triclosan can prevent encrustation by the mixed flora of uropathogens that commonly infect patients undergoing long-term catheterization. Models of the catheterized bladder were inoculated with communities of organisms isolated from patients who were experiencing catheter blockage. The catheter retention balloons were inflated with water or triclosan (3 g triclosan l−1 in 0.1 M sodium carbonate) and urine was supplied to the models for up to 7 days. The effect of triclosan was recorded on the viable cell populations, the pH of the residual urine and the times that catheters took to block. The extent of encrustation of the catheters was visualized by scanning electron microscopy. In models inoculated with communities containing Proteus mirabilis, triclosan prevented the rise in urinary pH that drives crystalline biofilm formation and catheter blockage. The biocide had no effect on populations of Enterococcus faecalis and Pseudomonas aeruginosa, but Proteus mirabilis, Escherichia coli and Klebsiella pneumoniae were eliminated from the residual urine and the catheters drained freely for the 7-day experimental period. In models inoculated with a mixed community containing Providencia rettgeri, catheters inflated with triclosan continued to block rapidly. Although K. pneumoniae and Proteus vulgaris were eliminated from the residual urine, there was no effect on the viability of Providencia rettgeri. The results indicate that the triclosan strategy should be limited to the treatment of patients who are infected with Proteus mirabilis.
Importance of Lineage-Specific Expansion of Plant Tandem Duplicates in the Adaptive Response to Environmental Stimuli
Authors: Hanada Kousuke , Zou Cheng , Lehti-Shiu Melissa D. , Shinozaki Kazuo , Shiu Shin-Han
Published: August 2008

Plants have substantially higher gene duplication rates compared with most other eukaryotes. These plant gene duplicates are mostly derived from whole genome and/or tandem duplications. Earlier studies have shown that a large number of duplicate genes are retained over a long evolutionary time, and there is a clear functional bias in retention. However, the influence of duplication mechanism, particularly tandem duplication, on duplicate retention has not been thoroughly investigated. We have defined orthologous groups (OGs) between Arabidopsis (Arabidopsis thaliana) and three other land plants to examine the functional bias of retained duplicate genes during vascular plant evolution. Based on analysis of Gene Ontology categories, it is clear that genes in OGs that expanded via tandem duplication tend to be involved in responses to environmental stimuli, while those that expanded via nontandem mechanisms tend to have intracellular regulatory roles. Using Arabidopsis stress expression data, we further demonstrated that tandem duplicates in expanded OGs are significantly enriched in genes that are up-regulated by biotic stress conditions. In addition, tandem duplication of genes in an OG tends to be highly asymmetric. That is, expansion of OGs with tandem genes in one organismal lineage tends to be coupled with losses in the other. This is consistent with the notion that these tandem genes have experienced lineage-specific selection. In contrast, OGs with genes duplicated via nontandem mechanisms tend to experience convergent expansion, in which similar numbers of genes are gained in parallel. Our study demonstrates that the expansion of gene families and the retention of duplicates in plants exhibit substantial functional biases that are strongly influenced by the mechanism of duplication. In particular, genes involved in stress responses have an elevated probability of retention in a single-lineage fashion following tandem duplication, suggesting that these tandem duplicates are likely important for adaptive evolution to rapidly changing environments.
Parents’ personality and parenting stress in families of children with spina bifida
Authors: Vermaes I. P. R. , Janssens J. M. A. M. , Mullaart R. A. , Vinck A. , Gerris J. R. M.
Published: August 2008

Background  Spina bifida (SB) can place parents at risk for increased levels of parenting stress. Little is known, however, about the role of parents’ intrapersonal resources. Therefore, based on ideas of the Disability‐Stress‐Coping Model, relations between the severity of SB, parents’ personality traits and parenting stress were examined.

Methods  Forty‐six mothers and 37 fathers of children with SB (6–14 years) participated. Severity of SB (physical dysfunctions and cognitive functions), parental personality (Big Five) and parenting stress (Parenting Stress Index) were measured. Multiple regression analyses were performed.

Results  The severity of the child's physical dysfunctions was positively associated with parenting stress. Extraversion (mothers only), emotional stability and agreeableness (fathers only) were negatively related to parenting stress. In the final model, 64% of the variance in mothers’ and 67% of the variance in fathers’ levels of parenting stress was explained. Parents’ personality traits explained the largest proportions of variance in parenting stress.

Conclusion  Mobility, bladder and bowel dysfunctions in school‐aged children with SB represent ongoing stressors for parents. Parents’ intrapersonal resources of positive affectivity, however, are more important determinants of parental adjustment to SB than the child's physical dysfunctions.
Autism spectrum disorders: clinical and research frontiers
Authors: Reading Richard
Published: August 2008

.
 
Caronna E. B.,
Milunsky J. M. &
Tager‐Flusberg H.
(
2008
)

,
93
,
518
–
523
.
 
DOI: 10.1136/adc.2006.115337
.

Autism spectrum disorders (ASD) are common neurodevelopmental disorders that occur along a broad continuum of severity with impairments in social interactions, communication and behaviour. This review highlights recent advances in autism research that shed light on the causes of the disorder and that have implications for clinical practice. It focuses on (1) the rising prevalence of ASD with attention given to recent epidemiological studies, (2) important genetic discoveries that may affect clinical evaluation of children with ASD, (3) active areas of research in cognitive neuroscience that seek to explain the underlying mechanisms of a complex disorder and (4) important studies on clinical populations with implications for screening and early identification of infants and toddlers with ASD.
Importance of early neglect for childhood aggression
Authors: Reading Richard
Published: August 2008

.
 
Kotch J. B.,
Lewis T.,
Hussey J. M.,
English D.,
Thompson R.,
Litrownik A. J.,
Runyan D. K.
,
et al.
(
2008
)

,
121
,
725
–
731
.
 
DOI: 10.1542/peds.2006‐3622
.

Objective  The goal was to examine the association between early childhood neglect (birth to age 2 years) and later childhood aggression at ages 4, 6 and 8 years, compared with aggression's associations with early childhood abuse and later abuse and neglect.

Methods  A prospective cohort of 1318 predominantly at‐risk children, recruited from four US cities and one southern state, were monitored from birth to 8 years of age. Maltreatment was determined through review of local child protective services records. A hierarchical, linear model approach, a special case of general, linear, mixed modelling, was used to predict aggressive behaviour scores, as reported by the child's primary caregiver at ages 4, 6 and 8 years.

Results  Only early neglect significantly predicted aggression scores. Early abuse, later abuse and later neglect were not significantly predictive in a controlled model with all four predictors.

Conclusion  This longitudinal study suggests that child neglect in the first 2 years of life may be a more important precursor of childhood aggression than later neglect or physical abuse at any age.
Spreading and impact of the World Health Organization's Allergic Rhinitis and its Impact on Asthma guidelines in everyday medical practice in France. Ernani survey
Authors: Demoly P. , Concas V. , Urbinelli R. , Allaert F‐A.
Published: August 2008

Objectives
The aim of this study was to determine the spreading level of the WHO‐ARIA (World Health Organization's Allergic Rhinitis and its Impact on Asthma) guidelines among the medical community and their influence on medical practices.

Methods
A cross‐sectional study based on a questionnaire was performed between April and July 2005 on randomly chosen general practitioners (GPs) (943) and ear, nose and throat (ENT) physicians (277).

Results
About 54.4% of the physicians claimed to know the WHO‐ARIA guidelines and 49.7% said they followed them. These results vary significantly, mainly according to medical specialty (ENT vs. GP). In comparison to those who did not know the guidelines, their patients benefited more frequently (P<0.0001) from allergen search (42.2% vs. 31.7%), a nasal endoscopy (38.3% vs. 26.0%), a follow‐up consultation (64.9% vs. 52.6%) and written information on rhinitis (30.7% vs. 14.1%). Paradoxically, they do not search more frequently for asthma and do not provide different first‐line treatment strategy and duration.
Sleep loss affects vigilance: effects of chronic insomnia and sleep therapy
Authors: ALTENA ELLEMARIJE , VAN DER WERF YSBRAND D. , STRIJERS ROB L. M. , VAN SOMEREN EUS J. W.
Published: August 2008

Although complaints of impaired daytime functioning are essential to the diagnosis of primary insomnia, objective evidence for cognitive dysfunction has been hard to establish. A prerequisite for understanding the neurocognitive consequences of primary insomnia is to establish task paradigms that robustly differentiate insomniacs from well‐sleeping subjects. We hypothesized that the decline in performance that typically occurs with an increasing cognitive demand would provide a more sensitive measure than performance on a single task version. The hypothesis was tested, first, by assessing the performance on two vigilance tasks with different cognitive demands in 25 elderly patients with primary insomnia and 13 healthy well‐sleeping age‐matched subjects. Secondly, we investigated the performance response to sleep therapy using a waiting‐list controlled design. Sleep therapy consisted of a multi‐component intervention including sleep restriction, cognitive behavioral therapy, bright‐light therapy, structured physical activity and body temperature manipulations. The results show that insomniacs differed markedly from controls in their reaction times across tasks with different cognitive demands: patients responded faster on the ‘simple’ vigilance task, yet slower on the ‘complex’ vigilance task. Sleep therapy effectively restored normal performance: patients became significantly slower on the ‘simple’ task and faster on the ‘complex’ task, returning to the performance levels of control subjects. These findings indicate that the performance decline associated with increasing cognitive demands is possibly the first sensitive and robust measure of the neurocognitive sequelae of insomnia. We suggest that future studies on cognition in primary insomnia should apply a design that varies task demands.
Possibility that certain hypnotics might cause cancer in skin
Authors: KRIPKE DANIEL F.
Published: August 2008

Fifteen epidemiologic studies have associated hypnotic drugs with excess mortality, especially excess cancer deaths. Until recently, insufficient controlled trials were available to demonstrate whether hypnotics actually cause any cancers. The US Food and Drug Administration (FDA) Approval History and Documents were accessed for zaleplon, eszopiclone and ramelteon. Since zolpidem was used as a comparison drug in zaleplon trials, some zolpidem data were also available. Incident cancers occurring during randomized hypnotics administration or placebo administration were tabulated. Combining controlled trials for the four drugs, there were 6190 participants given hypnotics and 2535 given placebo in parallel. There were eight mentions of incident non‐melanoma skin cancers among participants receiving hypnotics but no comparable mentions of cancers among those receiving placebo (P = 0.064, one‐tailed). There were also four mentions of incident tumors of uncertain malignancy among those receiving hypnotics but none among those receiving placebo, so combining uncertain and definite malignancies yielded a more significant contrast (P = 0.016). FDA files revealed that all four of the new hypnotics were associated with cancers in rodents. Three had been shown to be clastogenic. Together with the epidemiologic data and laboratory studies, the available evidence signals that new hypnotics may increase cancer risk. Due to limitations in available data, confirmatory research is needed.