bluuebunny/crossref_metadata_2025 huggingface dataset:
Running the gauntlet: the predation environment of small fish in the northern Gulf of St Lawrence, Canada
Authors: Duplisea Daniel E.
Published: February 2005

Predation size spectra were constructed for the northern Gulf of St Lawrence, covering prey size ranges that include pre-recruit cod. Predation by fish and harp seals was modelled with a log-normally distributed predator–prey size ratio along with a relationship between predator body size and the energy required. Fish concentrate predation on prey of weight 0.5–2 g, whereas harp seals prefer prey of 60–125 g. It is speculated that predation caused by harp seals on pre-recruits could be a major factor limiting cod recruitment in the system. The northern Gulf of St Lawrence is a cold boreal system with a large predatory seal population, and cod recruit older than elsewhere. Therefore, cod recruitment may be more strongly affected by predation in the northern Gulf of St Lawrence than in warmer systems such as the North Sea, where recruitment is strongly influenced by temperature.
A framework for making qualities of indicators transparent
Authors: Hauge Kjellrun Hiis , Olsen Erik , Heldal Hilde Elise , Skjoldal Hein Rune
Published: February 2005

A framework is presented to communicate different qualities of and uncertainties in indicators, and to enhance the transparency of conclusions and scientific advice based on them. The framework consists of four parts: Advice Statement, Power of Explanation, Robustness, and Performance Perspectives. The Advice Statement is descriptive and largely quantitative; the last three parts are more analytical and qualitative. Power of Explanation addresses the strength of the associated scientific knowledge. Robustness seeks to clarify how sensitive the indicator value and advice are to underlying assumptions. Performance Perspectives highlight prospects and drawbacks in a management context. The framework and its discussion are illustrated by examples on spawning-stock biomass of Northeast Arctic cod, technetium-99 concentrations in lobster, and harbour porpoise bycatch rates.
Management of the Failed Biaxial Wrist Replacement
Authors: TALWALKAR S. C. , HAYTON M. J. , TRAIL I. A. , STANLEY J. K.
Published: February 2005

Nine cases of failed biaxial wrist replacement underwent revision surgery and subsequent clinical and radiographic assessment at a mean follow-up of 28 months. Clinical assessment included the hospital for special surgery (HSS) and activities of daily living scoring systems. Five patients had a revision biaxial wrist replacement, three had wrist fusions and two underwent an excision arthroplasty. The mean HSS score was 73 for the revision biaxial replacements, 63 for the wrist fusions and 92 for the excision arthroplasties. The mean activities for daily living score was 16 for the revision biaxial replacements, 14 for the wrist fusion and 20 for the excision arthroplasties. Despite the experience of implant failure, six patients would still choose a primary wrist replacement again. All patients in this small series appear to have had good clinical outcomes. Revision to another wrist replacement appears no worse than a wrist fusion in the short term and patients value the preservation of movement that an implant offers.
Multibeam bathymetric and sediment profiler evidence for ice grounding on the Chukchi Borderland, Arctic Ocean
Authors: Jakobsson Martin , Gardner James V. , Vogt Peter R. , Mayer Larry A. , Armstrong Andrew , Backman Jan , Brennan Rick , Calder Brian , Hall John K. , Kraft Barbara
Published: February 2005

Multibeam bathymetry and 3.5-kHz sub-bottom profiler data collected from the US icebreakerHealyin 2003 provide convincing evidence for grounded ice on the Chukchi Borderland off the northern Alaskan margin, Arctic Ocean. The data show parallel, glacially induced seafloor scours, or grooves, and intervening ridges that reach widths of 1000 m (rim to rim) and as much as 40 m relief. Following previous authors, we refer to these features as “megascale glacial lineations (MSGLs).” Additional support for ice grounding is apparent from stratigraphic unconformities, interpreted to have been caused by ice-induced erosion. Most likely, the observed sea-floor features represent evidence for massive ice-shelf grounding. The general ESE/WNW direction of the MSGLs, together with sediment, evidently bulldozed off the Chukchi Plateau, that is mapped on the western (Siberian) side of the plateau, suggests ice flow from the Canada Basin side of Chukchi Borderland. Two separate generations of glacially derived MSGLs are identified on the Chukchi Borderland from theHealygeophysical data. The deepest and oldest extensive MSGLs appear to be draped by sediments less than 5 m thick, whereas no sediment drape can be distinguished within the resolution of the sub-bottom profiles on the younger generation.
New evidence for an extended occupation of the Provo shoreline and implications for regional climate change, Pleistocene Lake Bonneville, Utah, USA
Authors: Godsey Holly S. , Currey Donald R. , Chan Marjorie A.
Published: February 2005

Lake Bonneville was a climatically sensitive, closed-basin lake that occupied the eastern Great Basin during the late Pleistocene. Ongoing efforts to refine the record of lake level history are important for deciphering climate conditions in the Bonneville basin and for facilitating correlations with regional and global records of climate change. Radiocarbon data from this and other studies suggest that the lake oscillated at or near the Provo level much longer than depicted by current models of lake level change. Radiocarbon data also suggest that the lake dropped from threshold control much more rapidly than previously supposed. These revisions to the Lake Bonneville hydrograph, coupled with independent evidence of climate change from vegetation and glacial records, have important implications for conditions in the Bonneville basin and during the Pleistocene to Holocene transition.
Coping with unreliable public water supplies: Averting expenditures by households in Kathmandu, Nepal
Authors: Pattanayak Subhrendu K. , Yang Jui‐Chen , Whittington Dale , Bal Kumar K. C.
Published: February 2005

This paper investigates two complementary pieces of data on households' demand for improved water services, coping costs and willingness to pay (WTP), from a survey of 1500 randomly sampled households in Kathmandu, Nepal. We evaluate how coping costs and WTP vary across types of water users and income. We find that households in Kathmandu Valley engage in five main types of coping behaviors: collecting, pumping, treating, storing, and purchasing. These activities impose coping costs on an average household of as much as 3 U.S. dollars per month or about 1% of current incomes, representing hidden but real costs of poor infrastructure service. We find that these coping costs are almost twice as much as the current monthly bills paid to the water utility but are significantly lower than estimates of WTP for improved services. We find that coping costs are statistically correlated with WTP and several household characteristics.
Hemispheric asymmetry of the afternoon electron aurora
Authors: Fillingim M. O. , Parks G. K. , Frey H. U. , Immel T. J. , Mende S. B.
Published: February 2005

Using ultraviolet images from two global auroral imagers, IMAGE FUV in the northern hemisphere and Polar UVI in the south, we present the first synoptic scale conjugate observations of the dayside aurora. We find that the morphology of the afternoon aurora is significantly different in the two hemispheres. Multiple spots in a “string of pearls” configuration are seen in the southern hemisphere while the northern aurora is unstructured. We relate the observed asymmetry in the aurora to the Y GSM component of the IMF: a strong IMF BY modifies the ionospheric convection and field aligned current patterns, leading to the auroral asymmetry. Additionally, we suggest that the instability giving rise to the multiple spot morphology occurs at low altitude.
Rayleigh‐Taylor instability of a particle packed viscous fluid: Implications for a solidifying magma
Authors: Michioka Hiroki , Sumita Ikuro
Published: February 2005

We performed laboratory experiments of Rayleigh‐Taylor instability of superposed viscous fluids where the upper layer contains denser spherical solid particles. A series of experiments are made by varying the viscosity and the particle diameter, and we measure the growth rate and the wave length of the instability. The instability consists of fine‐scaled plumes, which coalesce as they descend. Plumes are observed to form intermittently and the particle layer thins with time, which finally descend as blobs. We find that the growth rate can be explained by using the linear stability analysis for Rayleigh‐Taylor instability of viscous fluids, by taking the effective viscosity of particle bed to be 20 times that of the fluid, and scale the thickness of the upper layer by twice the particle diameter. Using this scaling, we find that a partially solidified layer beneath the surface of a lava lake may become unstable by this mechanism.
Nonlinear impact of plasma sheet density on the storm‐time ring current
Authors: Ebihara Y. , Fok M.‐C. , Wolf R. A. , Thomsen M. F. , Moore T. E.
Published: February 2005

We investigated the nonlinear impact of the plasma sheet density on the total energy of the storm‐time ring current by means of a numerical simulation that self‐consistently solves the kinetic equation of ring current protons and the closure of the electric current between the magnetosphere and ionosphere. Results of the simulation indicate that when the convection electric field is self‐consistently coupled with the ring current, the total energy of the ring current ions trapped by the Earth's magnetic field is roughly proportional to ∼Nps1/2, where Nps is the plasma sheet density. This nonlinear response results from the strengthened shielding electric field with increasing Nps. The total energy is almost proportional to Nps when using an empirical convection electric field, which is independent of the condition of the simulated ring current. An empirical relationship between Nps and the solar wind density was used to estimate time‐dependent Nps. The result shows that the calculated Dst* tends to overshoot the observed one when the non‐self‐consistent electric field is employed. A better agreement was obtained with the self‐consistent electric field. We suggest that the nonlinear response of the ring current to Nps is one of the mechanisms that impedes the growth of the storm‐time ring current. Another mechanism is probably the saturation of the polar cap potential drop for high solar wind electric field.
Soil Conservation Service Curve Number method: How to mend a wrong soil moisture accounting procedure?
Authors: Michel Claude , Andréassian Vazken , Perrin Charles
Published: February 2005

This paper unveils major inconsistencies in the age‐old and yet efficient Soil Conservation Service Curve Number (SCS‐CN) procedure. Our findings are based on an analysis of the continuous soil moisture accounting procedure implied by the SCS‐CN equation. It is shown that several flaws plague the original SCS‐CN procedure, the most important one being a confusion between intrinsic parameter and initial condition. A change of parameterization and a more complete assessment of the initial condition lead to a renewed SCS‐CN procedure, while keeping the acknowledged efficiency of the original method.
crossveinless defines a new family of Twisted‐gastrulation‐like modulators of bone morphogenetic protein signalling
Authors: Vilmos Peter , Sousa‐Neves Rui , Lukacsovich Tamas , Lawrence Marsh J
Published: February 2005

The Twisted gastrulation (Tsg) proteins are modulators of bone morphogenetic protein (BMP) activity in both vertebrates and insects. We find that the crossveinless (cv) gene of Drosophila encodes a new tsg‐like gene. Genetic experiments show that cv, similarly to tsg, interacts with short gastrulation (sog) to modulate BMP signalling. Despite this common property, Cv shows a different BMP ligand specificity as compared with Tsg, and its expression is limited to the developing wing. These findings and the presence of two types of Tsg‐like protein in several insects suggest that Cv represents a subgroup of the Tsg‐like BMP‐modulating proteins.
Ras binding opens c‐Raf to expose the docking site for mitogen‐activated protein kinase kinase
Authors: Terai Kenta , Matsuda Michiyuki
Published: February 2005

A key signalling molecule, c‐Raf, is situated downstream from Ras and upstream from the mitogen‐activated protein kinase kinase (MEK). We studied the mechanism underlying the signal transduction from Ras to MEK by using probes based on the principle of fluorescence resonance energy transfer. In agreement with previous models, it was found that c‐Raf adopted two conformations: open active and closed inactive. Ras binding induced the c‐Raf transition from closed to open conformation, which enabled c‐Raf to bind to MEK. In the presence of a cytosolic Ras mutant, c‐Raf bound to, but failed to phosphorylate, MEK in the cytoplasm. In contrast, the cytosolic Ras mutant significantly enhanced MEK phosphorylation by a membrane‐targeted c‐Raf. These results demonstrated the essential role of Ras‐induced conformational change in MEK activation by c‐Raf.
Structure and dynamics of electrostatically interacting magnetic nanoparticles in suspension
Authors: Robert Aymeric , Wagner Joachim , Autenrieth Tina , Härtl Wolfram , Grübel Gerhard
Published: February 2005

We investigate the structure and dynamics of charge-stabilized CoFe2O4–SiO2 core-shell magnetic nanoparticles in suspensions. Small angle x-ray scattering and x-ray photon correlation spectroscopy allow us to analyze the intraparticle (core-shell) and interparticle structure of the suspension, as well as their dynamic and hydrodynamic behavior. Due to the weak magnetic interactions, the liquidlike structure is governed by screened Coulomb interactions. The hydrodynamic interactions of the measured systems are significantly stronger than predicted by current theories.
Modified Kelvin–Thomson equation considering ion-dipole interaction: Comparison with observed ion-clustering enthalpies and entropies
Authors: Yu Fangqun
Published: February 2005

The classical Kelvin–Thomson (CKT) equation does not consider the interaction of condensing molecules with the ions and hence is not able to treat polar and nonpolar molecules differently. The ion-clustering enthalpy and entropy changes predicted by CKT equation for small ions are known to be significantly less negative than those observed. In this paper, we derive a modified Kelvin–Thomson (MKT) equation, which considers the effect of dipole-ion interaction, by taking into account the kinetic energy change of condensing polar ligands as they approach the ions or the extra energy needed for dipole molecules to escape from the ion cluster. The clustering enthalpies and entropies for protonated clusters (H+Ln, with L=H2O, NH3, CH3OH, and C5H5N) are calculated based on MKT equation and compared with experimental data. Our calculations indicate that enthalpy values given by MKT equation are in very good agreement with experimental results for small ions (n⩽5) of all four species investigated. MKT predictions appear to be consistent with observed enthalpies for CH3OH at n⩾6 and for H2O at n=14–25, however, MKT equation cannot reproduce the observed discontinuous transition in enthalpy changes at n=6 for NH3 and at n=7–13 for H2O which is probably associated with the formation of inner shell. The stepwise entropy changes for small ions are 5–15calmol−1K−1 more negative when the effect of dipole-ion interaction is considered, which suggests that the ordered structure of the cluster ions can somewhat be accounted for by the dipole-ion interaction term.
Corrections to the law of mass action and properties of the asymptotic t=∞ state for reversible diffusion-limited reactions
Authors: Voituriez R. , Moreau M. , Oshanin G.
Published: February 2005

For diffusion-limited reversible A+A⇌B reactions we reexamine two fundamental concepts of classical chemical kinetics—the notion of “chemical equilibrium” and the “law of mass action.” We consider a general model with distance-dependent reaction rates, such that any pair of A particles, performing standard random walks on sites of a d-dimensional lattice and being at a distance μ apart of each other at time moment t, may associate forming a B particle at the rate k+(μ). In turn, any randomly moving B particle may spontaneously dissociate at the rate k−(λ) into a geminate pair of As “born” at a distance λ apart of each other. Within a formally exact approach based on Gardiner’s Poisson representation method we show that the asymptotic t=∞ state attained by such diffusion-limited reactions is generally not a true thermodynamic equilibrium, but rather a nonequilibrium steady state, and that the law of mass action is invalid. The classical concepts hold only in case when the ratio k+(μ)∕k−(μ) does not depend on μ for any μ.
Chemical reaction rates from ring polymer molecular dynamics
Authors: Craig Ian R. , Manolopoulos David E.
Published: February 2005

We show how the ring-polymer molecular dynamics method can be adapted to calculate approximate Kubo-transformed flux-side correlation functions, and hence rate coefficients for condensed phase reactions. An application of the method to the standard model for a chemical reaction in solution—a quartic double-well potential linearly coupled to a bath of harmonic oscillators—is found to give results of comparable accuracy to those of the classical Wigner model and the centroid molecular dynamics method. However, since the present method does not require that one evaluate the Wigner transform of a thermal flux operator or that one perform a separate path integral calculation for each molecular dynamics time step, we believe it will prove easier to apply to more general problems than either of these alternative techniques. We also present a (logarithmic) discretization scheme for the Ohmic bath in the system-bath model that gives converged results with just nine bath modes—a surprisingly small number for a model of a condensed phase reaction. Finally, we present some calculations of the transmission through an Eckart barrier which show that the present method provides a satisfactory (although not perfect) description of the deep quantum tunneling regime. Part of the reason for the success of the method is that it gives the exact quantum-mechanical rate constant for the transmission through a parabolic barrier, as we demonstrate analytically in the Appendix.
Ab initio potential-energy surfaces for complex, multichannel systems using modified novelty sampling and feedforward neural networks
Authors: Raff L. M. , Malshe M. , Hagan M. , Doughan D. I. , Rockley M. G. , Komanduri R.
Published: February 2005

A neural network/trajectory approach is presented for the development of accurate potential-energy hypersurfaces that can be utilized to conduct ab initio molecular dynamics (AIMD) and Monte Carlo studies of gas-phase chemical reactions, nanometric cutting, and nanotribology, and of a variety of mechanical properties of importance in potential microelectromechanical systems applications. The method is sufficiently robust that it can be applied to a wide range of polyatomic systems. The overall method integrates ab initio electronic structure calculations with importance sampling techniques that permit the critical regions of configuration space to be determined. The computed ab initio energies and gradients are then accurately interpolated using neural networks (NN) rather than arbitrary parametrized analytical functional forms, moving interpolation or least-squares methods. The sampling method involves a tight integration of molecular dynamics calculations with neural networks that employ early stopping and regularization procedures to improve network performance and test for convergence. The procedure can be initiated using an empirical potential surface or direct dynamics. The accuracy and interpolation power of the method has been tested for two cases, the global potential surface for vinyl bromide undergoing unimolecular decomposition via four different reaction channels and nanometric cutting of silicon. The results show that the sampling methods permit the important regions of configuration space to be easily and rapidly identified, that convergence of the NN fit to the ab initio electronic structure database can be easily monitored, and that the interpolation accuracy of the NN fits is excellent, even for systems involving five atoms or more. The method permits a substantial computational speed and accuracy advantage over existing methods, is robust, and relatively easy to implement.
Dynamics of turbulence spreading in magnetically confined plasmas
Authors: Gürcan Ö. D. , Diamond P. H. , Hahm T. S. , Lin Z.
Published: February 2005

A dynamical theory of turbulence spreading and nonlocal interaction phenomena is presented. The basic model is derived using Fokker–Planck theory, and supported by wave-kinetic and K-ϵ type closures. In the absence of local growth, the model predicts subdiffusive spreading of turbulence. With local growth and saturation via nonlinear damping, ballistic propagation of turbulence intensity fronts is possible. The time asymptotic front speed is set by the geometric mean of local growth and turbulent diffusion. The leading edge of the front progresses as the turbulence comes to local saturation. Studies indicate that turbulence can jump gaps in the local growth rate profile and can penetrate locally marginal or stable regions. In particular, significant fluctuation energy from a turbulent edge can easily spread into the marginally stable core, thus creating an intermediate zone of strong turbulence. This suggests that the traditional distinction between core and edge should be reconsidered.
Comparative analysis of two clinically active BCR-ABL kinase inhibitors reveals the role of conformation-specific binding in resistance
Authors: Burgess Michael R. , Skaggs Brian J. , Shah Neil P. , Lee Francis Y. , Sawyers Charles L.
Published: February 2005

Structural studies suggest that most point mutations in the BCR-ABL kinase domain cause resistance to the ABL kinase inhibitor imatinib by impairing the flexibility of the kinase domain, restricting its ability to adopt the inactive conformation required for optimal imatinib binding, rather than by directly interfering with drug contact residues. BMS-354825, currently in clinical development for imatinib-resistant chronic myelogenous leukemia, is a dual SRC/ABL kinase inhibitor that binds ABL in both the active and inactive conformation. To examine the potential role of conformational binding properties in drug resistance, we mapped the mutations in BCR-ABL capable of conferring resistance to BMS-354825. Through saturation mutagenesis, we identified 10 such BCR-ABL mutations, 8 of which occurred at drug contact residues. Some mutants were unique to BMS-354825, whereas others also conferred imatinib resistance. Remarkably, the identity of the amino acid substitution at either of two contact residues differentially affects sensitivity to imatinib or BMS-354825. The combination of imatinib plus BMS-354825 greatly reduced the recovery of drug-resistant clones. Our findings provide further rationale for considering kinase conformation in the design of kinase inhibitors against cancer targets.
Global mapping of the protein structure space and application in structure-based inference of protein function
Authors: Hou Jingtong , Jun Se-Ran , Zhang Chao , Kim Sung-Hou
Published: February 2005

We have constructed a map of the “protein structure space” by using the pairwise structural similarity scores calculated for all nonredundant protein structures determined experimentally. As expected, proteins with similar structures clustered together in the map and the overall distribution of structural classes of this map followed closely that of the map of the “protein fold space” we have reported previously. Consequently, proteins sharing similar molecular functions also were found to colocalize in the protein structure space map, pointing toward a previously undescribed scheme for structure-based functional inference for remote homologues based on the proximity in the map of the protein structure space. We found that this scheme consistently outperformed other predictions made by using either the raw scores or normalized
Z
-scores of pairwise
dali
structure alignment.
Vaccinia viruses with a serpin gene deletion and expressing IFN-γ induce potent immune responses without detectable replicationin vivo
Authors: Legrand Fatema A. , Verardi Paulo H. , Chan Kenneth S. , Peng Yue , Jones Leslie A. , Yilma Tilahun D.
Published: February 2005

In a continuing effort to develop safe and efficacious vaccine and immunotherapeutic vectors, we constructed recombinant vaccinia virus (rVV) vaccines lacking either the B13R (SPI-2) or the B22R (SPI-1) immune-modulating gene and coexpressing IFN-γ. B13R and B22R are nonessential VV immune-modulating genes that have antiapoptotic and antiinflammatory properties with sequence homology to serine protease inhibitors (serpins). IFN-γ is a cytokine with potent immunoregulatory, antineoplastic, and antiviral properties. We observed that these rVVs with a deletion in a serpin gene and expressing IFN-γ replicated to high titers in tissue culture yet were avirulent in both immunocompromised and immunocompetent mice with no detectable viral replication in these animals. A single immunization elicited potent humoral, T helper, and cytotoxic T cell immune responses in mice despite the absence of any detectable virus replicationin vivo. IFN-γ coexpression and the inactivation of one or more VV immune-modulating genes provide an optimized method for increasing the safety while maintaining the efficacy of rVV vaccines. This strategy provides a method for developing highly safe and efficacious vaccines for smallpox and other diseases and immunotherapeutic vectors.
An initial blueprint for myogenic differentiation
Authors: Blais Alexandre , Tsikitis Mary , Acosta-Alvear Diego , Sharan Roded , Kluger Yuval , Dynlacht Brian David
Published: February 2005

We have combined genome-wide transcription factor binding and expression profiling to assemble a regulatory network controlling the myogenic differentiation program in mammalian cells. We identified a cadre of overlapping and distinct targets of the key myogenic regulatory factors (MRFs)—MyoD and myogenin—and Myocyte Enhancer Factor 2 (MEF2). We discovered that MRFs and MEF2 regulate a remarkably extensive array of transcription factor genes that propagate and amplify the signals initiated by MRFs. We found that MRFs play an unexpectedly wide-ranging role in directing the assembly and usage of the neuromuscular junction. Interestingly, these factors also prepare myoblasts to respond to diverse types of stress. Computational analyses identified novel combinations of factors that, depending on the differentiation state, might collaborate with MRFs. Our studies suggest unanticipated biological insights into muscle development and highlight new directions for further studies of genes involved in muscle repair and responses to stress and damage.
CORONA, a Member of the Class III Homeodomain Leucine Zipper Gene Family in Arabidopsis, Regulates Stem Cell Specification and Organogenesis
Authors: Green Kirsten A. , Prigge Michael J. , Katzman Rebecca B. , Clark Steven E.
Published: February 2005

Organogenesis at the shoot meristem requires a delicate balance between stem cell specification and differentiation. In Arabidopsis thaliana, WUSCHEL (WUS) is a key factor promoting stem cell identity, whereas the CLAVATA (CLV1, CLV2, and CLV3) loci appear to promote differentiation by repressing WUS expression. In a screen for mutations modifying clv1 mutants, we have identified a novel regulator of meristem development we term CORONA (CNA). Whereas cna single mutant plants exhibit subtle defects in meristem development, clv cna double mutants develop massively enlarged apices that display early loss of organogenesis, misexpression of WUS and CLV3, and eventual differentiation of the entire apex. The CNA gene was isolated by positional cloning and found to encode a class III homeodomain Leu zipper protein. A missense mutation resulting in the dominant-negative cna-1 allele was identified in a conserved domain of unknown function, and a likely null allele was shown to display a similar but weaker phenotype. CNA is expressed in developing vascular tissue, diffusely through shoot and flower meristems, and within developing stamens and carpels. Our analysis of WUS expression in wild-type, clv, and clv cna plants revealed that, contrary to current models, WUS is neither necessary nor sufficient for stem cell specification and that neither WUS nor CLV3 is a marker for stem cell identity. We propose that CNA functions in parallel to the CLV loci to promote organ formation.
Effects of temperature and delayed initial feeding on the survival and growth of Japanese flounder larvae
Authors: Dou S. Z. , Masuda R. , Tanaka M. , Tsukamoto K.
Published: February 2005

The effects of the timing of initial feeding (0, 1, 2, 3 and 4 days after yolk exhaustion) and temperature (15, 18 and 21° C) on the point‐of‐no‐return (PNR), survival and growth of laboratory‐reared Japanese flounder Paralichthys olivaceus larvae were studied under controlled conditions. The larvae reached PNR on 7·7, 5·2 and 4·2 days‐post‐hatching (dph) at 15, 18 and 21° C, respectively. At each temperature, larval growth did not differ significantly among the delayed initial feedings 1 day before PNR but decreased significantly in larvae first fed after that. In the treatments where initial feeding was equally delayed, larvae grew significantly faster at 18 and 21° C than at 15° C. The larvae survived apparently better at 15 and 18° C than at 21° C when initial feeding was equally delayed. At each temperature, survival of the larvae first fed before PNR did not differ noticeably, while delayed initial feeding after that apparently reduced their survival. These results indicated that there existed a negatively temperature‐dependent PNR in the Japanese flounder larvae. Survival and growth of the larvae strongly depended on temperature as well as the timing of initial feeding. High temperature accelerated the yolk exhaustion and growth of the larvae and thus reduced their starvation tolerance and survival. To avoid potential starvation mortality and obtain good growth, the Japanese flounder larvae must establish successful initial feeding within 2 days after yolk exhaustion at 15° C and within 1 day at both 18 and 21° C.
Unusual gonad structure in the paedomorphic teleost Schindleria praematura(Teleostei: Gobioidei): a comparison with other gobioid fishes
Authors: Thacker C. , Grier H.
Published: February 2005

The gonads of eight gobioid species were examined histologically, including Pandaka pygmaea and Schindleria praematura, in order to investigate the manifestations of miniaturization and paedomorphosis in the gonads. Rearrangements of reproductive structures were found only in S. praematura, and included only the gonad tissues, not the gametes. Both sexes of S. praematura maintain basic germinal components: the spermatocyst composed of Sertoli cells and spermatogonia in the testis and the follicle and oocyte complex in the ovary. The stromal ovarian tissue and testicular interstitial tissue, however, is reduced compared to other gobies, and the number and location of gonial cells is restricted. This sequestered pattern of gonial cells is known as a restricted spermatogonial type in the testis, and has been reported only in atherinomorphs. The restriction of gonial cells in the ovary is extremely rare among teleosts, known only from one other species. These restricted gonial patterns in S. praematura are probably related to the overall reduction of morphological complexity in this genus, due to its extreme paedomorphosis.
Relationships between river flows and recreational catches of Australian bass
Authors: Growns I. , James M.
Published: February 2005

The relationship between river flows, summarized by hydrological indices, and catches of Australian bass Macquaria novemaculeata from recreational fishing competitions were examined in the Hawkesbury‐Nepean River system. Between 55 and 198 fishermen took part in six monthly fishing competitions. The number of hours fished increased from 570 to 1800 h between 1998 and 2001. A total of 11 275 Australian bass were caught over the study period. The percentage of young‐of‐the‐year (YOY) Australian bass and the catch of fish per unit effort was influenced by either the flow regime occurring in the same year and flow in the previous year. The number of Australian bass caught per unit effort was positively associated with the median volume of water and the number and duration of high flow events occurring in the previous year. The percentage of YOY Australian bass caught in any one year was positively associated with the median flow in the same year of capture and the maximum, mean and variation of daily flows, the number and duration of high flow events and the greatest rise and fall of daily flows in the previous year.
A new technique to gather 3‐D spatial information using a single camera
Authors: Laurel B. J. , Laurel C. J. , Brown J. A. , Gregory R. S.
Published: February 2005

A new technique using a single camera and shadows to determine 3‐D spatial positions of fishes in the laboratory is described. The apparatus consisted of a large aquarium (2·0 × 1·5 × 0·4 m), a wide‐angle camera mounted above and two light sources to cast shadows to either side of the fish. Using image analysis and vector mathematics, aquarium objects were plotted within 1·5 cm of their actual location along the x‐, y‐ and z‐axis. The technique was also successful in quantifying changes in 3‐D spatial pattern of juvenile fish, Atlantic cod Gadus morhua(7·4–8·6 cm standard length, LS) and cohabitant piscivorous shorthorned sculpin Myoxocephalus scorpinus(12·0–25·8 cm LS), at these same viewing fields. The new technique should have a wide application, largely because it is potentially less expensive, laborious and invasive than alternative methods for determining 3‐D positions of fishes.
Characterization of cortical alveoli content in several species of Antarctic notothenioids
Authors: Motta C. M. , Tammaro S. , Simoniello P. , Prisco M. , Ricchiari L. , Andreuccetti P. , Filosa S.
Published: February 2005

Cytochemical analyses was used to study the organization and content of cortical alveoli in eight species of Antarctic teleosts belonging to three different families of notothenioids: nototheniids, bathydraconids and channichthyids. Results indicated differences existed among the various species in alveolar size and distribution and in their content. In nototheniids, in particular, typical nucleoids were formed that could be large and single or small and multiple, according to the species considered. As demonstrated by the affinity to periodic acid‐Schiff (PAS) and lectin staining, these nucleoids were rich in glycoconjugates, whose nature was extremely varied in the different species, but not in lipo‐ or acidic proteins as indicated by Sudan Black B and silver salts staining. Protein extracts, electrophoresed and stained with Sudan, PAS and two lectins demonstrated that the alveoli in the two species, Trematomus bernacchii and Trematomus newnesi, contained c. 80 kDa protein rich in N‐acetylglucosamine groups. By contrast, the typical hyosophorins, described as the major alveolar content in other fishes, were apparently present only in T. newnesi.
Survival and behaviour of post‐smolt Atlantic salmon in coastal habitat with extreme tides
Authors: Lacroix G. L. , Knox D. , Stokesbury M. J. W.
Published: February 2005

The early marine migration of 55 Atlantic salmon post‐smolts tagged with acoustic transmitters was automatically monitored using 13 to 25 km long arrays of receivers deployed inside the Bay of Fundy, a coastal system on the east coast of Canada. The survival of post‐smolts from groups with short‐ and long‐term transmitters in coastal habitat up to 10 km from the river was 92 to 100%, indicating a successful transition to salt water and departure. Migration for 68 to 77% of post‐smolts followed a direct route and it was rapid (transit time usually <12 h). Post‐smolts initially migrated in a south to south‐west direction (i.e. orientation towards the mouth of the bay) and they were aggregated near the coast. Post‐smolts with long‐term transmitters were monitored 20 km from the river where they continued to be aggregated, moving near the coast through a ‘common corridor’, and their survival to that point was at least 84%. Post‐smolts from both groups travelled heading out of the coastal system during ebb tides. Flood tides interrupted migration, and they caused changes in travel direction and delays in departure for post‐smolts not leaving by a direct route. Monitoring of coastal habitat inside the Bay of Fundy intercepted 62% of migrating post‐smolts with long‐term transmitters returning after an initial absence of 2 to 22 days. Returning post‐smolts displayed a resident behaviour, using the habitat monitored inside the Bay of Fundy during July and August.
Occurrence of the parasite Glugea hertwigi in young‐of‐the‐year smelt in Lake Tuusulanjärvi
Authors: Pekcan‐Hekim Z. , Rahkonen R. , Horppila J.
Published: February 2005

Young‐of‐the‐year smelt Osmerus eperlanus in Lake Tuusulanjärvi were examined for Glugea hertwigi cysts. Cysts were visible on smelt in the beginning of August and showed a peak at the end of August. Glugea hertwigi may cause mortality among the most heavily infected young‐of‐the‐year smelts.
Estimating sampling bias when using electrofishing to catch stone loach
Authors: Reyjol Y. , Loot G. , Lek S.
Published: February 2005

Point abundance sampling, using electrofishing, for stone loach Barbatula barbatula in two habitats, riffle and pool, showed that there was no difference in density between the two habitats. The density of fish increased significantly (1·8 fold; P < 0·001) when the substratum of small cobbles (128–256 mm) was removed and electrofishing repeated.
Ontogenetic changes in temperature preference of Atlantic cod
Authors: Lafrance P. , Castonguay M. , Chabot D. , Audet C.
Published: February 2005

Final thermal preferendum (T) experiments were conducted in a horizontal thermal gradient tank from the beginning of August 2001 to mid‐November 2001 using Atlantic cod Gadus morhua from 6·5 to 79·0 cm fork length (LF). The value of T varied significantly (P < 0·005) with LF(T = 7·23–0·054LF), with smaller (younger) fish choosing higher temperatures than larger (older) fish. The preferendum varied from 6·9° C for fish of 6·5 cm to 3·0° C for those of 79·0 cm. Experiments comparing fish positions in the gradient tank between thermal gradients of 0·5–11·0 and 4·5–14·5° C demonstrated that fish positions were determined by temperature selection instead of undesirable tank effects. This study is the first to demonstrate the effect of ontogeny on temperature preferences of a marine fish species.
Preparing sagittae for examination of daily growth increments of young‐of‐the‐year fishes: a modification of the embed method
Authors: Plaza G. , Honda H. , Sakaji H. , Nashida K.
Published: February 2005

A modification (termed the slide‐glass‐embed‐method, SGEM) of the embed method for preparing fish sagittae is described. The SGEM is based on a very simple principle: a dome of mixed resin containing the embedded sagittae loses hardness after being heated and can be easily cut with dissecting scissors.
Improved Hydration Resistance of Synthesized Magnesia–Calcia Clinker by Surface Modification
Authors: Chen Shujiang , Lu Pingge , Chen Guorong , Cheng Jijian
Published: February 2005

Hydration resistance of synthesized MgO–CaO clinker was improved by surface modification using oleic acid, stearic acid, or complex acids as modifiers, with phosphoric acid as a reference. Unmodified and modified samples were evaluated using a powdering resistance test, weight change test, and flowability test. The remarkable effects of the modifiers on the hydration resistance and flowability of the clinker were manifested, and the complex modifier caused the most significant effect. The mechanism involved the formation of calcium‐containing films on the surfaces of the clinker particles, which protected them from hydration. The flowability of the clinker also increased with improved hydration resistance because of the decreased bonded‐moisture content. Comparison of infrared spectra between unmodified and modified samples confirmed the formation of surface films.
Low‐Temperature Synthesis of Fully Crystallized Spherical BaTiO3 Particles by the Gel–Sol Method
Authors: Hwang Un‐Yeon , Park Hyung‐Sang , Koo Kee‐Kahb
Published: February 2005

The synthesis of spherical BaTiO3 particles was attempted by a new technique, the “gel–sol method,” at 45°C. The (Ba–Ti) gel used as a starting material was prepared by aging mixtures of titanyl acylate with a barium acetate aqueous solution ([glacial acetic acid (AcOH)]/[titanium isopropoxide (TIP)] = 4, [barium acetate]/[TIP] = 1) at 45°C for 48 h. Potassium hydroxide (KOH) was used as a catalyst for the formation of BaTiO3. Powder X‐ray diffractometry (XRD) results and Fourier‐transform infrared (FT‐IR) measurements for the (Ba–Ti) gel showed that the gel was amorphous, but the spatial arrangement of barium and titanium in the (Ba–Ti) gel is similar to that in crystalline BaTiO3 particles. Fully crystallized spherical BaTiO3 powder with a particle size of 40–250 nm formed at the very low reaction temperature of 45°C. Scanning electron microscopy images showed that the final particles formed via aggregation of the fine particles that seem to be the primary particles of bulk (Ba–Ti) gel. From the XRD, FT‐IR, and Raman spectroscopy analysis, it was found that the crystal structure of the as‐prepared particles continuously transformed from cubic to tetragonal as the calcination temperature increased, and high crystalline tetragonal BaTiO3 phase was obtained at 1000°C after 1 h of heat treatment.
Influence of Impurities on Dispersion Properties of Bayer Alumina
Authors: Kiennemann J. , Pagnoux C. , Chartier T. , Baumard J. F. , Lamérant J. M.
Published: February 2005

Among the different impurities contained in Bayer alumina (Ca, Fe, Na, Si, Mg), calcium was found to greatly influence the dispersion of alumina particles in water. Up to 90% of calcium is dissolved at acidic pH, whereas calcium remains on the alumina surface in the basic pH range and screens the negative Al–O− charges. The presence of calcium, through reducing repulsive interactions between particles, has a negative effect on the dispersion of alumina. The adsorption of the Na+ salt of poly(acrylic acid) (PAA‐Na) is strongly influenced by Ca2+/PAA‐Na interactions in suspension with an increase of the maximum adsorbed amount of PAA‐Na in the presence of calcium. The amount of PAA‐Na needed to reach a high electrostatic repulsion and a minimum of viscosity is 2 times higher in the presence of 400 pm calcium than for a low calcium content (∼80 ppm). Finally, with an appropriate amount of PAA‐Na, a similar state of dispersion can be reached with or without the presence of calcium.
Dielectric Properties of Ba(SnxTi1−x)O3 Thin Films Grown by a Sol–Gel Process
Authors: Zhai Jiwei , Shen Bo , Yao Xi , Zhang Liangying , Chen Haydn
Published: February 2005

Ferroelectric Ba(SnxTi1−x)O3 (BTS) thin films were deposited using a sol–gel process on LaNiO3‐coated silicon substrates. The films showed a (100) preferred orientation depending on composition. The grain size decreased and the microstructure became denser with increasing tin content. The decreasing grain size with increasing tin may be attributable to lower grain‐growth rates from the more slowly diffusing Sn4+ ion, which has a larger ionic radius than Ti4+. The ferroelectric phase transition temperature of Ba(SnxTi1−x)O3 thin films with (a) x= 0, (b) x= 0.05, (c) x= 0.10, and (d) x= 0.15 occurs at about 150°, 45°, 28°, and 20°C, respectively. The highest K (figure of merit defined as K= tunability/tan δ={[ɛ(0) −ɛ(E)]/ɛ(E)}/tan δ) was found for BTS thin films with x= 0.10, even though tunability was highest with x= 0.05. An increase of dielectric loss as compared with films with x= 0.10 produced a decrease in K value. The J–E characteristics were highly nonlinear and the electric field resulting in nonlinearity moved to lower electric fields with decreasing tin content.
Tetragonal‐to‐Monoclinic Phase Transitions in Nanocrystalline Rare‐Earth‐Stabilized Zirconia Prepared by a Mild Hydrothermal Method
Authors: Xu Gang , Zhang Ya‐Wen , Liao Chun‐Sheng , Yan Chun‐Hua
Published: February 2005

Nanocrystalline 4‐mol%‐Sc2O3‐stabilized zirconia (4ScSZ) and 4‐mol%‐Y2O3‐stabilized zirconia (4YSZ) powders were prepared by a mild urea‐based hydrothermal method. The as‐prepared 4ScSZ and 4YSZ powders behaved with different tetragonal–monoclinic (t–m) transitions on calcination at temperatures between 400° and 1400°C. For the as‐calcined 4ScSZ samples, the monoclinic phase fraction varies discontinuously with increasing temperature, i.e., first increases, then decreases, and finally increases again; whereas the monoclinic phase content reduces monotonously for the as‐calcined 4YSZ samples, and only tetragonal phase is present over 1000°C. Such interesting results can be explained satisfactorily by considering the combined influences of crystallite size effect, microstrain, and the stabilization effect of the dopant. The microstrain relaxation is mainly responsible for the unusual phase transition in the 4ScSZ samples, while for the 4YSZ samples, the microstrain effect and crystallite size effect can be masked by the stabilization effect of the Y2O3 dopant due to its stronger stabilization capability.
Ambipolar Diffusion in Sintering and Diffusional Creep of Ionic Compounds
Authors: Kang Suk‐Joong L. , Yoo Han‐Il
Published: February 2005

The effective diffusion coefficient D̄ during sintering or diffusional creep of a polycrystalline ionic (ceramic) compound MaXb has been reexamined and suggested to be D̄=DMDX/(bDM+aDX), where Di is the diffusion coefficient of ion i (=M, X), in agreement with some previous investigations. This expression should be applicable to any system where ambipolar diffusion is driven by a stress gradient.
Anomalous Dynamical Charge Change Behavior of Nanocrystalline 3C‐SiC upon Compression
Authors: Liu Haozhe , Jin Changqing , Chen Jiuhua , Hu Jingzhu
Published: February 2005

Using diamond anvil cell (DAC) technique, in situ high‐pressure Raman scattering and energy‐dispersive X‐ray diffraction (EDXRD) experiments were used at room temperature to study 3C‐SiC with an average grain size of 30 nm. In contrast to its bulk counterpart, a decrease of the Born's transverse effective charge of these nanocrystals was observed with increasing pressure from measurements of the longitudinal and transverse optical phonon modes (longitudinal optical–transverse optical) splitting. This is therefore indicative of a diminishing ionicity of nanocrystalline 3C‐SiC on compression.