bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible all-solid-state switchable mirror on plastic sheet
Authors: Tajima Kazuki , Yamada Yasusei , Bao Shanhu , Okada Masahisa , Yoshimura Kazuki
Published: January 2008

We developed all-solid-state switchable mirror on flexible plastic [polyethylene terephthalate (PET)] sheet in the view point of low process cost and easy handling. Its optical switching property was investigated. Though the device on PET sheet showed over 4000cycles of switching in durability test, it was lower than that on glass. The reasons seemed to be related with heterogeneous structure, oxidation of surface layer and adhesion of the film. However, it remarkably results that the device on plastic sheet showed such a high durability nonetheless because the sheet is weak to mechanical stress.
Mesopiezoresistive effects in double-barrier resonant tunneling structures
Authors: Xu Liping , Wen Tingdun , Yang Xiaofeng , Xue Chenyang , Xiong Jijun , Zhang Wendong , Wu Mingzhong , Hochheimer Hans D.
Published: January 2008

This letter reports a mesopiezoresistive effect in a double-barrier resonant tunneling (DBRT) structure. In a DBRT system, an external mechanical stress causes a tensile strain, and the strain, in turn, affects the resonant tunneling and thereby the resistance. Theoretical analysis was carried out on an AlAs∕GaAs∕AlAs DBRT structure under in-plane uniaxial tensile stresses. The results show that the tunneling current and resistance of a DBRT structure change significantly with external stress-induced tensile strains. The results also show that the resistance-strain response can be tuned effectively by the external voltage. The effect has potential applications in miniature electromechanical devices.
At a glance determination of laser light polarization state
Authors: Castagna Riccardo , Lucchetta Daniele E. , Vita Francesco , Criante Luigino , Simoni Francesco
Published: January 2008

We report a simple technique for the visual determination of a laser light polarization state. The technique is based on a phenomenon occurring when laser light impinges on a particular photopolymerizable mixture sandwiched between two glass plates. After a brief irradiation, some polarization dependent patterns are observed far from the incidence spot. This effect is due to light scattered by the polymerized material and waveguided by the glass. A visual inspection of the characteristic patterns allows an immediate determination of the light polarization. This technique could be conveniently exploited for qualitative and/or quantitative polarimetry, as well as for designing polarization-driven devices.
Gain and continuous-wave laser power enhancement with a secondary discharge to predissociate molecular iodine in an electric oxygen-iodine laser
Authors: Benavides G. F. , Zimmerman J. W. , Woodard B. S. , Carroll D. L. , Verdeyen J. T. , Field T. H. , Palla A. D. , Solomon W. C.
Published: January 2008

Herein the authors report on the demonstration of a 50% enhancement in gain and 38% enhancement in continuous-wave laser power on the 1315nm transition of atomic iodine through the addition of a secondary discharge to predissociate the molecular iodine in an electric oxygen-iodine laser. In the primary discharge the O2(aΔ1) is produced by a radio-frequency-excited electric discharge sustained in an O2–He–NO gas mixture, and I(P1∕22) is then pumped using energy transferred from O2(aΔ1). A gain of 0.10%cm−1 was obtained and the total laser output power was 6.2W.
Polariton relaxation bottleneck and its thermal suppression in bulk GaN microcavities
Authors: Stokker-Cheregi F. , Vinattieri A. , Semond F. , Leroux M. , Sellers I. R. , Massies J. , Solnyshkov D. , Malpuech G. , Colocci M. , Gurioli M.
Published: January 2008

We discuss the presence of a polariton bottleneck in bulk GaN microcavities. Angle resolved photoluminescence measurements were performed using low excitation power densities for several negative detunings between the exciton and photon modes. At low temperatures, we observe an enhancement in the emission intensity at angles corresponding to the anticrossing of the lower and upper polariton modes, a clear demonstration of the polariton relaxation bottleneck. This feature becomes less prominent with increasing temperature, eventually disappearing at room temperature. We conclude that polariton-acoustic phonon scattering is the dominant polariton relaxation mechanism in bulk GaN microcavities, as supported by theoretical simulations.
Analyses on double resonance behavior in microwave magnetic permeability of multiwalled carbon nanotube composites containing Ni catalyst
Authors: Wen Fusheng , Yi Haibo , Qiao Liang , Zheng Hong , Zhou Dong , Li Fashen
Published: January 2008

The double resonance behavior of microwave magnetic permeability has been observed for multiwalled carbon nanotube composites containing Ni catalyst. One of them is due to the natural resonance at 6.00GHz and another is due to the exchange resonance at 10.11GHz. The natural resonance is dependent on magnetocrystalline anisotropy and shape anisotropy of Ni nanostick catalyst and the calculated result of exchange resonance mode with a few modifications was close to the experiment. It is believed that the coexistence of natural resonance and exchange resonance is benefial to large bandwidth as a microwave absorber.
Energy-band alignments of HfO2 on p-GaAs substrates
Authors: Dalapati Goutam Kumar , Oh Hoon-Jung , Lee Sung Joo , Sridhara Aaditya , Wong Andrew See Weng , Chi Dongzhi
Published: January 2008

Interfacial reaction and the energy-band alignments of HfO2 films on p-GaAs substrate were investigated by using x-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. It has been demonstrated that the alloying of HfO2 with Al2O3 (HfAlO) can significantly reduce native oxides formation and increases the valence-band offsets (VBOs) at HfO2∕p-GaAs interface. In addition, the effects of Si interfacial passivation layer on band alignments have also been studied. VBO at HfO2∕p-GaAs, HfAlO∕p-GaAs, and HfO2∕Si∕p-GaAs interfaces were 2.85, 2.98, and 3.07eV, respectively.
Organic-inorganic hybrid transparent materials containing chromium ion-doped forsterite crystals as gain media
Authors: Arai Yusuke , Qin Guanshi , Suzuki Takenobu , Ohishi Yasutake , Tani Takao , Saeki Shu
Published: January 2008

Organic-inorganic hybrid transparent materials containing chromium ion-doped forsterite (Cr:Mg2SiO4) crystals are investigated as gain media. Thin films and bulk samples are prepared by a sol-gel technique. Starting sols for host matrices, which are prepared from diphenyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and titanium tetra-n-butoxide, are mixed with flame spray made Cr:Mg2SiO4 nanocrystals ultrasonically. The hybrid materials containing Cr:Mg2SiO4 with high transparency are realized by matching refractive indices of the host matrices with that of Cr:Mg2SiO4 by controlling starting sols’ composition. A broad emission centered at 1170nm is confirmed under the excitation at 976nm.
Ultrafine-grained β-type titanium alloy with nonlinear elasticity and high ductility
Authors: Li S. J. , Cui T. C. , Li Y. L. , Hao Y. L. , Yang R.
Published: January 2008

Although stress-induced martensitic transformation accelerates grain refinement during plastic deformation, it results in serious damage to recoverable elasticity and ductility of severely cold-rolled multifunctional titanium alloys. Here, large-scale nonlinear elasticity and high ductility were achieved simultaneously in an ultrafine-grained Ti–Nb–Zr–Sn alloy by severe warm rolling at 473K to suppress the martensitic transformation from the β to the α″ phase. These results suggest that high strength can be attained in nonlinear elastic titanium alloys by improving the stability of the β phase with body-centered-cubic crystal structure through both composition design and grain refinement.
Donor nonuniformity in undoped and Si doped n-GaN prepared by epitaxial lateral overgrowth
Authors: Yakimov E. B. , Vergeles P. S. , Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Lee In-Hwan , Lee Cheul Ro , Pearton S. J.
Published: January 2008

Local donor concentrations were measured in the regions of lateral overgrowth and in the normal vertical growth regions of n-GaN films prepared by epitaxial lateral overgrowth (ELOG). The films were doped with Si to various concentrations. The local donor densities were determined from measurements of the collection efficiency dependence of the electron beam induced current (EBIC) on the energy of the probing electron beam. This dependence was compared with the results of theoretical modeling using the local donor density and diffusion length of charge carriers as fitting parameters. The results show that the donor concentration in the ELOG regions is systematically more than two times lower than the concentration in the vertical growth regions in the gaps of the SiO2 mask used for selective growth. The observed difference is ascribed to the anisotropy of the Si incorporation efficiency. Comparison of these EBIC results with the results of capacitance-voltage profiling obtained on large area Schottky diodes shows that the latter yield the donor concentration close to the concentration in the laterally overgrown regions.
When pliers become fingers in the monkey motor system
Authors: Umiltà M. A. , Escola L. , Intskirveli I. , Grammont F. , Rochat M. , Caruana F. , Jezzini A. , Gallese V. , Rizzolatti G.
Published: February 2008

The capacity to use tools is a fundamental evolutionary achievement. Its essence stands in the capacity to transfer a proximal goal (grasp a tool) to a distal goal (e.g., grasp food). Where and how does this goal transfer occur? Here, we show that, in monkeys trained to use tools, cortical motor neurons, active during hand grasping, also become active during grasping with pliers, as if the pliers were now the hand fingers. This motor embodiment occurs both for normal pliers and for “reverse pliers,” an implement that requires finger opening, instead of their closing, to grasp an object. We conclude that the capacity to use tools is based on an inherently goal-centered functional organization of primate cortical motor areas.
Liver X receptor β (LXRβ): A link between β-sitosterol and amyotrophic lateral sclerosis–Parkinson's dementia
Authors: Kim Hyun-Jin , Fan Xiaotang , Gabbi Chiara , Yakimchuk Konstantin , Parini Paolo , Warner Margaret , Gustafsson Jan-Åke
Published: February 2008

Administration of β-sitosterol (42 mg/kg per day) for 3 weeks to 8-month-old male LXRβ
−/−
mice resulted in the death of motor neurons in the lumbar region of the spinal cord and loss of tyrosine hydroxylase-positive dopaminergic neurons in the substantia nigra. In mice at 5 months of age, β-sitosterol had no observed toxicity but at 16 months of age, it caused severe paralysis and symptoms typical of dopaminergic dysfunction in LXRβ
−/−
mice. WT mice were not affected by these doses of β-sitosterol. In 5-month-old mice, levels of the intestinal transporters, ABCG5/8 and Niemann-Pick C1 Like 1, were not affected by loss of liver X receptor (LXR) β and/or treatment with β-sitosterol nor were there changes in plasma levels of cholesterol or β-sitosterol. In 8-month-old LXRβ
−/−
mice there was activation of microglia in the substantia nigra pars reticulata and aggregates of ubiquitin and TDP-43 in the cytoplasm of large motor neurons in the lumbar spinal cord. Brain cholesterol concentrations were higher in LXRβ
−/−
than in their WT counterparts, and treatment with β-sitosterol reduced brain cholesterol in both WT and LXRβ
−/−
mice. In LXRβ
−/−
mice but not in WT mice levels of 24-hydrocholesterol were increased upon β-sitosterol treatment. These data indicate that multiple mechanisms are involved in the sensitivity of LXRβ
−/−
mice to β-sitosterol. These include activation of microglia, accumulation of protein aggregates in the cytoplasm of large motor neurons, and depletion of brain cholesterol.
A vaccine strategy against AIDS: An HIV gp41 peptide immunization prevents NKp44L expression and CD4
+
T cell depletion in SHIV-infected macaques
Authors: Vieillard Vincent , Le Grand Roger , Dausset Jean , Debré Patrice
Published: January 2008

We previously showed that a gp41 peptide (3S) induces expression of a natural killer (NK) ligand (NKp44L) on CD4
+
T cells during HIV-1 infection and that those cells are highly sensitive to NK lysis. In HIV-infected patients, anti-3S antibodies are associated with the maintenance of CD4
+
T cell counts close to their baseline values, and CD4
+
T cells decrease with the antibody titer. This study sought to determine whether anti-3S immunization could prevent NKp44L expression on these CD4
+
T cells
in vivo
and inhibits the subsequent decline in CD4
+
T cell counts by immunizing macaques with 3S and then infecting them with simian HIV
162P3
. The results show that anti-3S antibodies inhibited NKp44L expression and NK activity and cytotoxicity. They also decreased the apoptosis rate of CD4
+
T cells in peripheral blood and lymph nodes. These data raise questions about the pathogenesis of HIV and present opportunities for both preventive and therapeutic HIV vaccine strategies.
Fourteen‐Month‐Olds Know What “We” Have Shared in a Special Way
Authors: Moll Henrike , Richter Nadja , Carpenter Malinda , Tomasello Michael
Published: February 2008

People often express excitement to each other when encountering an object that they have shared together previously in some special way. This study investigated whether 14‐month‐old infants know precisely what they have and have not shared in a special way (and with whom). In the experimental condition an adult and infant shared an object (the target) excitedly because it unexpectedly reappeared in several places. They then shared 2 other objects (the distractors) in a more normal fashion. Later, the adult reacted excitedly to a tray containing all 3 objects and then made an ambiguous request for the infant to hand “it” to her. There were 2 control conditions. In 1 of them, a different adult, who knew none of the 3 objects, made the ambiguous request. In the other control condition, the adult who made the request had previously experienced the objects only alone, while the infant looked on unengaged. Infants in the experimental condition chose the target object more often than the distractors and more often than they chose it in either control condition. These results demonstrate that 14‐month‐old infants can identify which one of a set of objects “we”—and not just I or you alone—have had a special experience with in the past.
On the accuracy of some mapping techniques used to study the magnetic field dynamics in tokamaks
Authors: Constantinescu D. , Dumbrajs O. , Igochine V. , Weyssow B.
Published: January 2008

The dynamics of magnetic field lines and of charged particles in toroidal chambers are commonly analysed by numerically solving the dynamical equations. They may also be analysed using deterministic reduced models, i.e. low-dimensional discrete time approximations (maps) of the Hamiltonian continuous time models. We report on the accuracy of the latter method by considering the mapping technique derived from the Hamilton–Jacobi equation. The optimum time stepping in some models for the study of the magnetic field in tokamaks is determined by using local criteria. Special attention is given to the analysis of stochasticity produced by time discretization.
Analysis of Unregulated Formin Activity Reveals How Yeast Can Balance F-Actin Assembly between Different Microfilament-based Organizations
Authors: Gao Lina , Bretscher Anthony
Published: January 2008

Formins are regulated actin-nucleating proteins that are widespread among eukaryotes. Overexpression of unregulated formins in budding yeast is lethal and causes a massive accumulation of disorganized cable-like filaments. To explore the basis of this lethality, a cDNA library was screened to identify proteins whose overexpression could rescue the lethality conferred by unregulated Bnr1p expression. Three classes of suppressors encoding actin-binding proteins were isolated. One class encodes proteins that promote the assembly of actin cables (TPM1, TPM2, and ABP140), suggesting that the lethality was rescued by turning disorganized filaments into functional cables. The second class encodes proteins that bind G-actin (COF1, SRV2, and PFY1), indicating that reduction of the pool of actin available for cable formation may also rescue lethality. Consistent with this, pharmacological or genetic reduction of available actin also protected the cell from overproduction of unregulated Bnr1p. The third class consists of Las17p, an activator of the formin-independent Arp2/3p-dependent actin nucleation pathway. These results indicate that proper assembly of actin cables is sensitive to the appropriate balance of their constituents and that input into one pathway for actin filament assembly can affect another. Thus, cells must have a way of ensuring a proper balance between actin assembly pathways.
Impaired Hair Follicle Morphogenesis and Polarized Keratinocyte Movement upon Conditional Inactivation of Integrin-linked Kinase in the Epidermis
Authors: Nakrieko Kerry-Ann , Welch Ian , Dupuis Holly , Bryce Dawn , Pajak Agnieszka , St. Arnaud René , Dedhar Shoukat , D'Souza Sudhir J. A. , Dagnino Lina
Published: January 2008

Integrin-linked kinase (ILK) is key for cell survival, migration, and adhesion, but little is known about its role in epidermal development and homeostasis in vivo. We generated mice with conditional inactivation of the Ilk gene in squamous epithelia. These mice die perinatally and exhibit skin blistering and severe defects in hair follicle morphogenesis, including greatly reduced follicle numbers, failure to progress beyond very early developmental stages, and pronounced defects in follicular keratinocyte proliferation. ILK-deficient epidermis shows abnormalities in adhesion to the basement membrane and in differentiation. ILK-deficient cultured keratinocytes fail to attach and spread efficiently and exhibit multiple abnormalities in actin cytoskeletal organization. Ilk gene inactivation in cultured keratinocytes causes impaired ability to form stable lamellipodia, to directionally migrate, and to polarize. These defects are accompanied by abnormal distribution of active Cdc42 to cell protrusions, as well as reduced activation of Rac1 upon induction of cell migration in scraped keratinocyte monolayers. Significantly, alterations in cell spreading and forward movement in single cells can be rescued by expression of constitutively active Rac1 or RhoG. Our studies underscore a central and distinct role for ILK in hair follicle development and in polarized cell movements, two key aspects of epithelial morphogenesis and function.
Sep7 Is Essential to Modify Septin Ring Dynamics and Inhibit Cell Separation duringCandida albicansHyphal Growth
Authors: González-Novo Alberto , Correa-Bordes Jaime , Labrador Leticia , Sánchez Miguel , Vázquez de Aldana Carlos R. , Jiménez Javier
Published: January 2008

When Candida albicans yeast cells receive the appropriate stimulus, they switch to hyphal growth, characterized by continuous apical elongation and the inhibition of cell separation. The molecular basis of this inhibition is poorly known, despite its crucial importance for hyphal development. In C. albicans, septins are important for hypha formation and virulence. Here, we used fluorescence recovery after photobleaching analysis to characterize the dynamics of septin rings during yeast and hyphal growth. On hyphal induction, septin rings are converted to a hyphal-specific state, characterized by the presence of a frozen core formed by Sep7/Shs1, Cdc3 and Cdc12, whereas Cdc10 is highly dynamic and oscillates between the ring and the cytoplasm. Conversion of septin rings to the hyphal-specific state inhibits the translocation of Cdc14 phosphatase, which controls cell separation, to the hyphal septum. Modification of septin ring dynamics during hyphal growth is dependent on Sep7 and the hyphal-specific cyclin Hgc1, which partially controls Sep7 phosphorylation status and protein levels. Our results reveal a link between the cell cycle machinery and septin cytoskeleton dynamics, which inhibits cell separation in the filaments and is essential for hyphal morphogenesis.
The Microtubule-severing Proteins Spastin and Katanin Participate Differently in the Formation of Axonal Branches
Authors: Yu Wenqian , Qiang Liang , Solowska Joanna M. , Karabay Arzu , Korulu Sirin , Baas Peter W.
Published: January 2008

Neurons express two different microtubule-severing proteins, namely P60-katanin and spastin. Here, we performed studies on cultured neurons to ascertain whether these two proteins participate differently in axonal branch formation. P60-katanin is more highly expressed in the neuron, but spastin is more concentrated at sites of branch formation. Overexpression of spastin dramatically enhances the formation of branches, whereas overexpression of P60-katanin does not. The excess spastin results in large numbers of short microtubules, whereas the excess P60-katanin results in short microtubules intermingled with longer microtubules. We hypothesized that these different microtubule-severing patterns may be due to the presence of molecules such as tau on the microtubules that more strongly shield them from being severed by P60-katanin than by spastin. Consistent with this hypothesis, we found that axons depleted of tau show a greater propensity to branch, and that this is true whether or not the axons are also depleted of spastin. We propose that there are two modes by which microtubule severing is orchestrated during axonal branch formation, one based on the local concentration of spastin at branch sites and the other based on local detachment from microtubules of molecules such as tau that regulate the severing properties of P60-katanin.
Galectin-1 Is a Novel Structural Component and a Major Regulator of H-Ras Nanoclusters
Authors: Belanis Liron , Plowman Sarah J. , Rotblat Barak , Hancock John F. , Kloog Yoel
Published: January 2008

The organization of Ras proteins into nanoclusters on the inner plasma membrane is essential for Ras signal transduction, but the mechanisms that drive nanoclustering are unknown. Here we show that epidermal growth factor receptor activation stimulates the formation of H-Ras.GTP-Galectin-1 (Gal-1) complexes on the plasma membrane that are then assembled into transient nanoclusters. Gal-1 is therefore an integral structural component of the H-Ras–signaling nanocluster. Increasing Gal-1 levels increases the stability of H-Ras nanoclusters, leading to enhanced effector recruitment and signal output. Elements in the H-Ras C-terminal hypervariable region and an activated G-domain are required for H-Ras–Gal-1 interaction. Palmitoylation is not required for H-Ras–Gal-1 complex formation, but is required to anchor H-Ras–Gal-1 complexes to the plasma membrane. Our data suggest a mechanism for H-Ras nanoclustering that involves a dual role for Gal-1 as a critical scaffolding protein and a molecular chaperone that contributes to H-Ras trafficking by returning depalmitoylated H-Ras to the Golgi complex for repalmitoylation.
Hard prey, soft jaws and the ontogeny of feeding mechanics in the spotted ratfishHydrolagus colliei
Authors: Huber Daniel R , Dean Mason N , Summers Adam P
Published: January 2008

The spotted ratfishHydrolagus collieiis a holocephalan fish that consumes hard prey (durophagy) but lacks many morphological characters associated with durophagy in other cartilaginous fishes. We investigated its feeding biomechanics and biting performance to determine whether it can generate bite forces comparable with other durophagous elasmobranchs, how biting performance changes over ontogeny (21–44 cm SL) and whether biomechanical modelling can accurately predict feeding performance in holocephalans.Hydrolagus collieican generate absolute and mass-specific bite forces comparable with other durophagous elasmobranchs (anterior=104 N, posterior=191 N) and has the highest jaw leverage of any cartilaginous fish studied. Modelling indicated that cranial geometry stabilizes the jaw joint by equitably distributing forces throughout the feeding mechanism and that positive allometry of bite force is due to hyperallometric mechanical advantage. However, bite forces measured through tetanic stimulation of the adductor musculature increased isometrically. The jaw adductors ofH. collieifatigued more rapidly than those of the piscivorous spiny dogfishSqualus acanthiasas well. The feeding mechanism ofH. collieiis a volume-constrained system in which negative allometry of cranial dimensions leaves relatively less room for musculature. Jaw adductor force, however, is maintained through ontogenetic changes in muscle architecture.
Fish mitochondrial genomics: sequence, inheritance and functional variation
Authors: Brown K. H.
Published: January 2008

Mitochondrial genomic research currently primarily focuses on the analysis and understanding of how mitochondrial mutations produce detrimental phenotypes in humans. Reasons for this focus on negative impacts include the large number of human diseases that are known to result from specific mitochondrial genomes, and the long held belief that mitochondria change only through the accumulation of mutations due to its clonal, maternal inheritance. Recent studies are beginning to challenge these preconceptions and have shown that mitochondrial genomes can have significant positive impacts. Although the number of studies using fishes as models in mitochondrial research is limited, many fish model species provide excellent opportunity for furthering the understanding of mitochondrial genomes, their interactions with the nuclear genome, the potential for understanding the mechanisms of how functional variation effects organisms and how selection for positive functional variation effects population variation.
Comparison of genetic diversity at microsatellite loci and quantitative traits in hatchery populations of Japanese flounder Paralichthys olivaceus
Authors: Shikano T. , Shimada Y. , Suzuki H.
Published: January 2008

Relationships of genetic diversity at microsatellite loci and quantitative traits were examined in hatchery‐produced populations of Japanese flounder using a relatively straightforward experiment. Five hatchery populations produced by wild‐caught and domesticated broodstocks were used to examine the effects of different levels (one to three generations) of domestication on the genetic characteristics of hatchery populations. Allelic richness at seven microsatellite loci in all hatchery populations was lower than that in a wild population. Genetic variation measured by allelic richness and heterozygosity tended to decrease with an increase in generations of domestication. In addition, the degree of genetic differentiation from a wild population increased with an increase in generations of domestication. Significant differences in three morphometric traits (dorsal and anal fin ray counts and vertebral counts) and three physiological traits (high temperature, salinity and formalin tolerance) were observed among the hatchery populations. The degree of phenotypic difference among populations was larger in morphometric traits than in physiological traits. The divergence pattern of some quantitative traits was similar to that observed at microsatellite loci, suggesting that domestication causes the decrease of genetic variation and the increase of genetic differentiation for some quantitative traits concomitantly with those for microsatellite loci. Significant positive correlation was observed between FST and the degree of phenotypic difference in the three morphometric traits and formalin tolerance, indicating that genetic variation at microsatellite loci predicts the degree of phenotypic divergence in some quantitative traits.
DNA barcoding reveals a likely second species of Asian sea bass (barramundi) (Lates calcarifer)
Authors: Ward R. D. , Holmes B. H. , Yearsley G. K.
Published: January 2008

DNA barcoding – the sequencing of a c. 650 base pair region of the mitochondrial cytochrome c oxidase I gene – strongly suggests that barramundi (Lates calcarifer) from Australia and from Myanmar are different species (Kimura 2 parameter distance of c. 9·5%). Cytochrome b sequence data support this conclusion (distance c. 11·3%). Further examination, both genetic and morphological, of L. calcarifer throughout its range is recommended.
Using genotype simulations and Bayesian analyses to identify individuals of hybrid origin in Australian bass: lessons for fisheries management
Authors: Schwartz T. S. , Beheregaray L. B.
Published: January 2008

Simulated genotypes, Bayesian analyses and molecular genetic data were used to detect individuals of hybrid origin and hybrid introgression between the Australian bass (Macquaria novemaculeata), a species extensively stocked in Australia, and estuary perch (Macquaria colonorum). Based on this analytical framework, 93% of the hybrids up to three generations later could be distinguished from the Australian bass. Individuals of hybrid origin were identified in all three rivers sampled. In addition, this study verified the fertility of hybrids between Australian bass and estuary perch as determined through genomic introgression. This study exemplifies an analytical procedure that has implications for identifying suitable individuals for use in breeding and restocking programmes for other species.
DNA barcoding for the identification of smoked fish products
Authors: Smith P. J. , McVeagh S. M. , Steinke D.
Published: January 2008

DNA barcoding was applied to the identification of smoked products from fish in 10 families in four orders and allowed identification to the species level, even among closely related species in the same genus. Barcoding is likely to become a standard tool for identification of fish specimens and products.
Species boundaries and evolutionary lineages in the blue green damselfishes Chromis viridis and Chromis atripectoralis (Pomacentridae)
Authors: Froukh T. , Kochzius M.
Published: January 2008

The blue green damselfishes were described as a complex of two species (Chromis viridis and Chromis atripectoralis), mainly based on the colouration of the pectoral fin base. In this study, the authors analysed the mitochondrial control region of 88 blue green damselfishes from Indonesia, the Philippines, Red Sea and the Great Barrier Reef. The phylogenetic analysis revealed four major monophyletic clades. Two clades included specimens of C. atripectoralis from the Great Barrier Reef and individuals of C. viridis from the Red Sea, respectively. The remaining individuals of C. viridis from Indonesia and the Philippines were grouped into two clades without phylogeographic structure. The obtained results (1) verified that C. viridis and C. atripectoralis are distinct species and (2) revealed three deep evolutionary lineages of C. viridis in the Indo‐Malay Archipelago and the Red Sea.
QTL for meat tenderness in the M. longissimus lumborum of cattle
Authors: Davis G. P. , Moore S. S. , Drinkwater R. D. , Shorthose W. R. , Loxton I. D. , Barendse W. , Hetzel D. J. S.
Published: January 2008

Meat tenderness has been difficult to improve using standard genetic selection. Marker assisted selection holds great promise if markers for meat tenderness can be identified. Here, we report quantitative trait loci (QTL) for beef tenderness identified in 598 animals of three Charolais–Brahman × Belmont Red pedigrees after screening the whole genome using 183 DNA markers. In addition to the usual Warner–Bratzler peak force measurements, tenderness was also measured using compression, adhesion and pressure‐heat‐treated peak force. Three QTL for meat tenderness in the M. longissimus lumborum muscle were found, two of which have not been reported before. One is located in the HEL9‐CSSM47 interval on bovine chromosome 8 with a LOD of 3.1 and an effect of 1.02 phenotypic standard deviations for tensile strength of cooked muscle as measured by adhesion. A second QTL is located near CSRM60 on bovine chromosome 10 with a LOD of 2.4 and an effect of 0.48 phenotypic standard deviations for compression. The third QTL is in a region of bovine chromosome 7 that has previously been reported to have a QTL affecting peak force. This region also shows effects on compression and a combined tenderness index. These QTL are all for the myofibrillar component of meat tenderness. No QTL were found for pressure‐treated peak force, which is an estimate of the connective tissue component muscle of meat tenderness.
Limited frequency of the CYP2C19*17 allele and its minor role in a Japanese population
Authors: Sugimoto Katsuyoshi , Uno Tsukasa , Yamazaki Hiroshi , Tateishi Tomonori
Published: January 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• A novel CYP2C19 gene variant, CYP2C19*17, is associated with increased metabolic activity.

• Ethnic differences in the frequency of the variant allele have been reported. However, the frequency of the CYP2C19*17 allele has not been studied in the Japanese population.

WHAT THIS STUDY ADDS

• In a population of 265 healthy Japanese subjects, a low frequency (1.3%) of the CYP2C19*17 allele was observed.

• The limited frequency of the *17 allele and the absence of a subject homozygous for *17 indicated that CYP2C19*17 would play a minor role in a Japanese population.

AIMS

We investigated the CYP2C19*17 allelic frequency in Japanese subjects, and evaluated whether CYP2C19*17 is an important determinant of interindividual variability of CYP2C19 activity.

METHODS

We enrolled 265 subjects to determine their CYP2C19 genotype and plasma metabolic ratio following a single dose of 40 mg omeprazole.

RESULTS

Seven subjects heterozygous for CYP2C19*17 and no *17/*17 subjects resulted in the CYP2C19*17 frequency being 1.3%. These heterozygotes had moderate metabolic activities when compared with the metabolic ratio of the other subjects.

CONCLUSIONS

The low frequency of CYP2C19*17 and the absence of *17/*17 indicates that CYP2C19*17 plays a minor role in the Japanese population.
Ezetimibe's effect on platelet aggregation and LDL tendency to peroxidation in hypercholesterolaemia as monotherapy or in addition to simvastatin
Authors: Hussein Osamah , Minasian LiLia , Itzkovich Yaroslav , Shestatski Karina , Solomon Lizora , Zidan Jamal
Published: January 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Statins demonstrate a pleiotropic effect which contributes beyond the hypocholesterolaemic effect to prevent atherosclerosis.

WHAT THIS STUDY ADDS

• Ezetimibe has an antioxidative effect when given as monotherapy or as an add‐on to the statin, simvastatin.

AIMS

To investigate the effect of lowering low‐density lipoprotein‐cholesterol (LDL‐C) on platelet aggregation and LDL tendency to peroxidation by ezetimibe alone or with simvastatin in hypercholesterolaemia.

METHODS

Sixteen patients with LDL‐C >3.4 mmol l−1 received ezetimibe for 3 months (Part I). Twenty‐two patients on fixed simvastatin dose with LDL‐C >2.6 mmol l−1 were enrolled (Part II). Part II patients continued simvastatin treatment 20 mg day−1 for 6 weeks, then received 20 mg day−1 simvastatin combined with ezetimibe 10 mg day−1 for another 6 weeks. The tendency of LDL to peroxidation measured by lag time in minutes required for initiation of LDL oxidation and by LDL oxidation at maximal point (plateau) was measured before and after ezetimibe treatment.

RESULTS

Part I: Ezetimibe 10 mg daily for 3 months decreased plasma LDL‐C level 16% (P = 0.002), prolonged lag time to LDL oxidation from 144 ± 18 min to 195 ± 16 min (P < 0.001), decreasing maximal aggregation from 83 ± 15% to 60 ± 36% (P = 0.04). Part II: Serum level LDL‐C decreased 23% (P = 0.02) and lag time in minutes to LDL oxidation was prolonged from 55.9 ± 16.5 to 82.7 ± 11.6 (P < 0.0001) using combined simvastatin–ezetimibe therapy. There were no differences in platelet aggregation.

CONCLUSIONS

Ezetimibe was associated with decreased platelet aggregation and LDL tendency to peroxidation. Treatment with ezetimibe in addition to simvastatin has an additive antioxidative effect on LDL.
Staged diabetes management according to individual patient insulin resistance and β‐cell function ameliorates glycaemic control in type 2 diabetes mellitus
Authors: Choi Sung Hee , Hur Kyu Yeon , Kim Dae Jung , Ahn Chul Woo , Kang Eun Seok , Cha Bong Soo , Lim Sung Kil , Huh Kap Bum , Lee Hyun Chul
Published: January 2008

Objective  The current consensus algorithm for management of type 2 diabetes is based on the fasting glucose concentration and glycated haemoglobin A1c (HbA1c) level. We applied a new therapeutic strategy by assessing insulin secretion and insulin resistance, in addition to glucose concentrations in individual patients.

Design and patients  We enrolled 193 patients with type 2 diabetes. The patients were assigned to one of six groups according to insulin secretion measured by the serum fasting C‐peptide concentration and insulin resistance measured by an insulin tolerance test (ITT). The two groups were treated differently: 108 patients were treated using a new staged diabetes management (SDM) strategy and 85 patients continued with conventional therapy.

Measurements  We compared metabolic variables in the two groups at baseline and 12 months after enrolment.

Results  In patients treated with the SDM strategy, fasting glucose concentration decreased from 9·8 ± 2·1 to 8·2 ± 1·7 mmol/l (P < 0·001). Postprandial 2‐h glucose concentration decreased from 14·19 ± 3·34 to 12·27 ± 3·24 mmol/l (P < 0·001). HbA1c level decreased from 8·37 ± 1·42% to 7·72 ± 1·39% (P < 0·001). About 43% of the new SDM group achieved an HbA1c of < 7·0% compared with 25% of patients in the conventional treatment group.

Conclusions  The new SDM strategy, based on individual data on insulin resistance and insulin secretion, may provide valuable clinical benefits in non‐obese Korean patients with type 2 diabetes.
Significant correlation of glycated albumin, but not glycated haemoglobin, with arterial stiffening in haemodialysis patients with type 2 diabetes
Authors: Kumeda Yasuro , Inaba Masaaki , Shoji Shigeichi , Ishimura Eiji , Inariba Hiromi , Yabe Sachiko , Okamura Mikio , Nishizawa Yoshiki
Published: January 2008

Objective  We recently reported that glycated albumin (GA) is a better indicator of glycaemic control compared with glycated haemoglobin (HbA1c) in haemodialysis (HD) patients with type 2 diabetes. As poor glycaemic control is considered an independent risk factor for atherosclerosis in diabetes, the relationship between GA, HbA1c and arterial stiffening was examined in HD patients with type 2 diabetes.

Patients and methods  The present study comprised 134 HD patients with type 2 diabetes, and 158 patients without diabetes. Brachial‐ankle pulse wave velocity (baPWV) was measured in all patients using a waveform analyser.

Results  The mean plasma glucose (PG), GA and HbA1c levels were 7·49 ± 2·28 mmol/l, 20·8 ± 5·57% and 5·62 ± 1·26%, respectively, in HD patients with diabetes (n = 134), which were significantly greater than the respective values of 5·77 ± 1·89 mmol/l, 15·6 ± 2·34% and 4·98 ± 0·80% in those without diabetes (n = 158) (P < 0·0001). BaPWV was 21·69 ± 6·90 m/s in HD patients with diabetes, which was significantly greater than the value of 18·74 ± 4·89 m/s in those without diabetes (P < 0·0001). When the analysis was performed in a combined population of those patients with and without diabetes, the mean PG (r = 0·155, P < 0·05) and GA (r = 0·117, P < 0·05), but not HbA1c (r = 0·092, P = 0·125), exhibited significant correlations with baPWV. Multivariate regression analysis, which included age, gender, mean blood pressure, and serum levels of albumin, creatinine and LDL cholesterol, to evaluate the independent association of each marker for glycaemic control with baPWV values in HD patients demonstrated that GA, but not HbA1c or PG, was an independent factor that was significantly associated in a positive manner with baPWV in HD patients.

Conclusion  It was suggested that poor glycaemic control, as reflected by increased GA values, might be associated with increased arterial stiffening in HD patients.
The use of the ‘borderline’ category in the reporting of cervical cytopathology in the UK: results of a survey conducted under the aegis of the British Society for Clinical Cytology
Authors: Duvall E.
Published: January 2008

Objective:  To determine how the ‘borderline’ category was used by cytopathologists in the UK when reporting cervical smears.

Methods:  A questionnaire was sent by email to members of the British Society for Clinical Cytology.

Results:  There is wide variation in the use of the ‘borderline’ category in the UK but the majority of respondents (77.6%) used it when reporting smears that were either on the borderline between negative and low grade squamous dyskaryosis (‘borderline ?low grade’), or on the borderline between negative and high grade squamous dyskaryosis (‘borderline ?high grade’), or on the borderline between negative and glandular dyskaryosis ‘borderline ?glandular dyskaryosis’). A significant minority (15.7%), however, did not use ‘borderline’ when reporting smears that showed an abnormality that was possibly high grade squamous dyskaryosis. A majority (79.1%) of respondents thought that it would be useful to have separate reporting categories for ‘borderline ?low grade’ and ‘borderline ?high grade’.

Conclusions:  There is diversity in the use of the category ‘borderline’ in the UK. The proposed revised BSCC terminology with separate categories for borderline ?low grade, borderline ?high grades and borderline ? glandular dyskaryosis reflects the opinion of the majority of respondents to the questionnaire.
Existing in plenty: abundance, biomass and diversity of ciliates and meiofauna in small streams
Authors: REISS JULIA , SCHMID‐ARAYA JENNY M.
Published: January 2008

1. The ciliate and metazoan meiofaunal assemblages of two contrasting lowland streams in south‐east England were examined over the period of a year, using a high taxonomic resolution. Monthly samples were taken from an oligotrophic, acid stream (Lone Oak) and a circumneutral, nutrient‐rich stream (Pant) between March 2003 and February 2004.

2. We assessed the relative importance of ciliates and rotifers within the small‐sized benthic assemblage with respect to their abundance, biomass and species richness. In addition, we examined the influence of abiotic and biotic parameters and season on the assemblage composition at two levels of taxonomic resolution (species and groups).

3. Ciliates dominated the assemblages numerically, with maximum densities of over 900 000 and 6 000 000 ind. m−2 in Lone Oak and Pant respectively. Rotifers and nematodes dominated meiofaunal densities, although their contribution to total meiofaunal biomass (maxima of 71.9 mgC m−2 in Lone Oak and of 646.8 mgC m−2 in the Pant) was low and rotifer biomass equalled that of ciliates.

4. Although the two streams differed in terms of total abundance of ciliates and meiofauna and shared only 7% of species, the relative proportion of groups was similar. Sediment grain size distribution (the percentile representing the 0.5–1 mm fraction) was correlated with assemblage structure at the species level, revealing the tight coupling between these small organisms and their physical environment. Seasonal changes in the relative abundance of groups followed similar patterns in both streams, and were correlated with the abundance of cyclopoid copepods and temperature.

5. Information on these highly abundant but often overlooked faunal groups is essential for estimates of overall abundance, biomass, species richness and productivity in the benthos, and as such has important implications for several areas of aquatic research, e.g. for those dealing with trophic dynamics.
Physiological and visual refuges in a metalimnion: an experimental study of effects of clay turbidity and an oxygen minimum on fish predation
Authors: LILJENDAHL‐NURMINEN ANNE , HORPPILA JUKKA , LAMPERT WINFRIED
Published: January 2008

1. The effectivity of elevated clay turbidity and low‐oxygen concentration in the metalimnion as refuges for chaoborid larvae against fish predation was studied in experimental water columns.

2. When 70–80 nephelometric turbidity unit clay turbidity was combined with 3–4 mg L−1 oxygen concentration, prey capture rate by fish (golden orfe Leuciscus idus) was reduced by 74% compared with the control treatment with no refuges. Oxygen and turbidity refuges alone did not significantly reduce the feeding rate.

3. All fish in the control treatment dwelled in the metalimnion, but 36% of the fish in the low‐oxygen treatment and 23% of the fish in the turbidity treatment stayed in the epilimnion. In the combined treatment, 54% of the fish were in the epilimnion.

4. The results demonstrated that a combination of moderately elevated turbidity and lowered oxygen concentration in the metalimnion is an effective protection against fish predation, while turbidity or oxygen refuge alone are much less effective.

5. In the treatment with the combined refuge, oxygen concentration limited the time fish could spend in the metalimnion and turbidity affected the detection of prey through changes in reactive distance.

6. Because of the combined effects of turbidity and oxygen refuges, planktivorous fish and phantom midge larvae may co‐occur in clay‐turbid lakes in high densities. Such situation is problematic for biomanipulation, which aims to enhance the grazing rate of zooplankton through reduction of planktivorous fish.
A latitudinal gradient in climate effects on seabird demography: results from interspecific analyses
Authors: SANDVIK HANNO , COULSON TIM , SÆTHER BERNT‐ERIK
Published: January 2008

For an understanding of the effect of climate change on animal population dynamics, it is crucial to be able to identify which climatologic parameters affect which demographic rate, and what the underlying mechanistic links are. An important reason for why the interactions between demography and climate still are poorly understood is that the effects of climate vary both geographically and taxonomically. Here, we analyse interspecifically how different climate variables affect the breeding success of North Atlantic seabird species along latitudinal and longitudinal gradients. By approaching the problem comparatively, we are able to generalize across populations and species. We find a strong interactive effect of climate and latitude on breeding success. Of the climatic variables considered, local sea surface temperatures during the breeding season tend to be more relevant than the North Atlantic Oscillation (NAO). However, the effect of NAO on breeding success shows a clear geographic pattern, changing in sign from positive in the south to negative in the north. If this interaction is taken account of, the model explains more variation than any model with sea surface temperature. This superiority of the NAO index is due to its ability to capture effects of more than one season in a single parameter. Mechanistically, however, several lines of evidence suggest that sea surface temperature is the biologically most relevant explanatory variable.