bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative studies of the auditory periphery of deep-sea fish.
Authors: Deng Xiaohong , Wagner H. Jochen , Popper Arthur N.
Published: January 2009

Many species of deep-sea fish have special sensory adaptations to help them survive at great depths and with lack of light. While such adaptations are best known in the visual system, it is likely that there are also auditory system adaptations that enable the fish to make use of the auditory scene. However, there are few data on the auditory system of deep-sea fish. The study compared inner ear structures between several such species. Some features in the ears in the species studied were similar to structures associated with enhanced hearing ability in the ears of some shallow water hearing specialists. These findings support the hypothesis that some deep-sea fishes have evolved specializations for hearing. We also report some features in the ears of deep-sea fishes that have never been seen in the ears of other vertebrates. These include specializations in the orientation of sensory hair cells, diversity in hair cell ciliary bundle shapes, and a number of unique otolith characteristics. While it is not possible to test hearing in deep-sea fishes, the various adaptations found suggest that at least some have evolved highly specialized adaptations to enable them to use sound in the deep sea.
Delivery of drug, or gene, to blood vessel wall using intravascular ultrasound and microbubbles.
Authors: Hossack John
Published: January 2009

Atherosclerotic arteries are routinely treated using balloon angioplasty followed by stent placement. We developed a concept for a new therapy to prevent restenosis involving using ultrasound and microbubble-based drug/gene carriers. A number of early in vitro and in vivo results are presented. In particular, data for delivery of antiproliferative gene via microbubbles ruptured via catheter-based intravascular ultrasound (IVUS) at the site of vessel injury in vivo in a pig coronary artery are presented. Optimal design of a modified IVUS catheter is discussed. The proposed catheter includes a bubble port, an elongated single element transducer to provide radiation force to cause the bubbles to traverse to the vessel wall, and a bubble rupture transducer. The bubble rupture transducer is ideally coincident with an imaging IVUS scanning single element or annular phased array. These requirements provide the impetus to develop enhanced designs of both PZT based transducers and silicon micromachined transducers. In our initial pig study, transfection efficiency was measured using fluorescence microscopy and quantified as the percent of vessel perimeter cells expressing red fluorescent protein. We observed 23.3±6.0% transfection in the treated vessel whereas the control exhibited 3.6±2% transfection.
Analysis of
Drosophila
Segmentation Network Identifies a JNK Pathway Factor Overexpressed in Kidney Cancer
Authors: Liu Jiang , Ghanim Murad , Xue Lei , Brown Christopher D. , Iossifov Ivan , Angeletti Cesar , Hua Sujun , Nègre Nicolas , Ludwig Michael , Stricker Thomas , Al-Ahmadie Hikmat A. , Tretiakova Maria , Camp Robert L. , Perera-Alberto Montse , Rimm David L. , Xu Tian , Rzhetsky Andrey , White Kevin P.
Published: January 2009

We constructed a large-scale functional network model in
Drosophila melanogaster
built around two key transcription factors involved in the process of embryonic segmentation. Analysis of the model allowed the identification of a new role for the ubiquitin E3 ligase complex factor SPOP. In
Drosophila
, the gene encoding SPOP is a target of segmentation transcription factors.
Drosophila
SPOP mediates degradation of the Jun kinase phosphatase Puckered, thereby inducing tumor necrosis factor (TNF)/Eiger–dependent apoptosis. In humans, we found that SPOP plays a conserved role in TNF-mediated JNK signaling and was highly expressed in 99% of clear cell renal cell carcinomas (RCCs), the most prevalent form of kidney cancer. SPOP expression distinguished histological subtypes of RCC and facilitated identification of clear cell RCC as the primary tumor for metastatic lesions.
Axon Regeneration Requires a Conserved MAP Kinase Pathway
Authors: Hammarlund Marc , Nix Paola , Hauth Linda , Jorgensen Erik M. , Bastiani Michael
Published: January 2009

Regeneration of injured neurons can restore function, but most neurons regenerate poorly or not at all. The failure to regenerate in some cases is due to a lack of activation of cell-intrinsic regeneration pathways. These pathways might be targeted for the development of therapies that can restore neuron function after injury or disease. Here, we show that the DLK-1 mitogen-activated protein (MAP) kinase pathway is essential for regeneration in
Caenorhabditis elegans
motor neurons. Loss of this pathway eliminates regeneration, whereas activating it improves regeneration. Further, these proteins also regulate the later step of growth cone migration. We conclude that after axon injury, activation of this MAP kinase cascade is required to switch the mature neuron from an aplastic state to a state capable of growth.
Relationship between spat density, food availability, and growth of spawners in cultured Mizuhopecten yessoensis in Funka Bay: concurrence with El Niño Southern Oscillation
Authors: Baba Katsuhisa , Sugawara Rieko , Nitta Hisashi , Endou Kiyoshi , Miyazono Akira
Published: January 2009

To elucidate the factors that influence the interannual variation in the density of cultured Japanese scallop ( Mizuhopecten yessoensis ) spat, we analyzed the relationship between spat density (Ds), monthly chlorophyll a (chl a) concentration, water temperature, and adductor muscle weight of spawners over 15 years (1992–2006) in Funka Bay (Japan) on the western North Pacific Ocean. The interannual variation of spat density was best explained by a campaniform model that used chl a concentration in February ([chl]Feb) and a categorical variable that indicates whether growth of spawners in a year is low or not as independent variables (R2 = 0.91). The gonadosomatic index increased fastest in February. Low growth years were detected as outliers in the Ds – [chl]Feb relationship and were characterized by an average weight of adductor muscles in February of <12 g. Therefore, food availability during gonadal development and growth conditions of spawners were the main factors determining spat density. The proportion of ovary necrosis was high in the years of low [chl]Feb and low growth. Those years corresponded with El Niño and La Niña years, respectively. Thus, global climatic anomalies apparently affect reproduction of the scallop in Funka Bay.
A biophysical model of Lake Erie walleye (Sander vitreus) explains interannual variations in recruitment
Authors: Zhao Yingming , Jones Michael L. , Shuter Brian J. , Roseman Edward F.
Published: January 2009

We used a three-dimensional coupled hydrodynamic–ecological model to investigate how lake currents can affect walleye ( Sander vitreus ) recruitment in western Lake Erie. Four years were selected based on a fall recruitment index: two high recruitment years (i.e., 1996 and 1999) and two low recruitment years (i.e., 1995 and 1998). During the low recruitment years, the model predicted that (i) walleye spawning grounds experienced destructive bottom currents capable of dislodging eggs from suitable habitats (reefs) to unsuitable habitats (i.e., muddy bottom), and (ii) the majority of newly hatched larvae were transported away from the known suitable nursery grounds at the start of their first feeding. Conversely, during two high recruitment years, predicted bottom currents at the spawning grounds were relatively weak, and the predicted movement of newly hatched larvae was toward suitable nursery grounds. Thus, low disturbance-based egg mortality and a temporal and spatial match between walleye first feeding larvae and their food resources were predicted for the two high recruitment years, and high egg mortality plus a mismatch of larvae with their food resources was predicted for the two low recruitment years. In general, mild westerly or southwesterly winds during the spawning–nursery period should favour walleye recruitment in the lake.
Mucus: a new tissue fraction for rapid determination of fish diet switching using stable isotope analysis
Authors: Church M. Robbins , Ebersole Joseph L. , Rensmeyer Kirk M. , Couture Ryan B. , Barrows Frederic T. , Noakes David L.G.
Published: January 2009

Stable isotope analysis of diet switching by fishes often is hampered by slow turnover rates of the tissues analyzed (usually muscle or fins). We examined epidermal mucus as a potentially faster turnover “tissue” that might provide a more rapid assessment of diet switching. In a controlled hatchery experiment, we switched the diet of juvenile steelhead (sea-run rainbow trout, Oncorhynchus mykiss ) from a plant-based feed with low δ13C and δ15N to a fish-meal-based diet with higher delta values. We found mucus to provide a significantly more rapid response to diet switching (half-life = 36 days for δ15N, 30 days for δ13C) than muscle tissue (half-life = 94 days for δ15N, 136 days for δ13C), even for growing juvenile fish. Mucus may provide a rapid turnover “tissue” for analysis of diet (or habitat) switching by fish. It has the additional advantage that it may be sampled nonlethally in some fishes, thereby avoiding problems in studying threatened or endangered species. This is the first report of the use of fish mucus in stable isotope analyses of fish tissues.
Resistance toGremmeniella abietina(European race, large tree type) in introducedPinus contortaand nativePinus sylvestrisin Sweden
Authors: Bernhold Andreas , Hansson Per , Rioux Danny , Simard Marie , Laflamme Gaston
Published: January 2009

To study the resistance of Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex Watts to large tree type (LTT) Gremmeniella abietina (Lagerberg) Morelet of the European race, seedlings of P. contorta and Pinus sylvestris L. were planted in gaps of an infected 40-year-old P. sylvestris stand in 2005 and assessed for symptoms in 2006–2007. In 2007, 45% and 32% of the P. contorta and P. sylvestris seedlings were infected, respectively. However, mortality was lower and recovery was better in the P. contorta seedlings. The mean infection length on surviving seedlings was significantly shorter in P. contorta (4 cm) compared with P. sylvestris (10 cm), and 47% of the P. contorta seedlings had developed new leader shoots in 2007 compared with 19% of the P. sylvestris seedlings. Histopathological examinations of the transition zone of infected shoots showed that P. contorta, as well as P. sylvestris, produced ligno-suberized boundaries extending from healthy needle bases transversally across the shoots. Together with areas of phenol-filled cells, these boundaries completed the compartmentalization of the invaded outermost parts of a majority of the infected seedlings. Our results indicate that P. contorta is more resistant to LTT G. abietina than P. sylvestris.
Are salamanders good bioindicators of sustainable forest management in boreal forests?
Authors: Pearce Jennie , Venier Lisa
Published: January 2009

Salamanders have been identified as potential indicators of sustainable forest management in boreal Ontario, Canada. However, little information is available on their distribution, abundance, and habitat associations within the boreal forests on which to base a monitoring program. We surveyed salamanders near White River, Ontario, and related their distribution to climate and vegetation information and to habitat suitability models currently used for forest planning within the region. Primarily red-backed salamanders ( Plethodon cinereus Green) and blue-spotted salamanders ( Ambystoma laterale Hallowell) were recorded, although both were observed in low numbers and captures varied spatially and temporally. Capture rates were 3–7 times lower for P. cinereus than has been reported elsewhere. Trend monitoring will be expensive and have low power to detect significant declines over moderate time frames unless capture rates can be doubled and within-site variability in capture rates halved. We found few strong habitat relationships using either coverboard or pitfall trap data. Plethodon cinereus was negatively correlated with the volume of downed wood, which has been noted in other regions and may be an artefact of the coverboard survey technique. Further focused studies in the boreal forest are required to support the use of both habitat supply models and trend analysis to monitor salamander populations.
AN ISOMORPHISM THEOREM FOR ALEXANDER BIQUANDLES
Authors: LAM DAISY , NELSON SAM
Published: January 2009

We show that two Alexander biquandles M and M′ are isomorphic if and only if there is an isomorphism of ℤ[s±1, t±1]-modules h : (1 - st)M → (1 - st)M′ and a bijection g : Os(A) → Os(A′) between the s-orbits of sets of coset representatives of M/(1 - st)M and M′/(1 - st)M′ respectively satisfying certain compatibility conditions.
STRONGLY INTERACTING ELECTROWEAK THEORIES AND THEIR FIVE-DIMENSIONAL ANALOGS AT THE LHC
Authors: POMAROL ALEX
Published: January 2009

Strongly interacting theories of electroweak (EW) symmetry breaking provide an elegant solution to the hierarchy problem. In these models the EW symmetry can either be broken without a Higgs or by means of a composite Higgs boson. These scenarios have been recently investigated in the framework of five-dimensional warped models that, according to the AdS/CFT correspondence, have a four-dimensional holographic interpretation in terms of strongly coupled field theories. We describe the minimal Higgsless and composite Higgs model and show how they can successfully pass all the electroweak precision tests and solve the flavor problems. We explore the implications of these models at the LHC (Large Hadron Collider).
EFFECT OF LASER AND MECHANICAL PARAMETERS ON STRENGTH OF FIBER BRAGG GRATINGS
Authors: TAHIR BASHIR AHMED , RASHID ABDUL , ASIF M. , AFAQ A. , ALI JALIL , ABDUL RAHMAN ROSLY
Published: January 2009

The length of the optical fiber which contains the sensor must be able to withstand the tensile loads that will be placed on it during the duration of its service lifetime. It is important to assess the effect of the UV radiation and removal of coating on the strength of the fiber within the region where the grating has been written. In this study, we have identified the various mechanical and laser fabrication parameters which constrain the strength of fiber gratings. These factors include the laser pulse rate, laser energy per pulse, UV exposure time, methods of coating removal and environmental degradation (moisture). The variation in strength with respect to these factors is discussed in detail. However, it is observed in all the investigations that the average strength of all the fiber grating samples decreased. Finally, the enhancement of mechanical strength of fiber gratings can be achieved by adjusting the laser settings and improving the coating removal methods.
HPM AND VIM METHODS FOR FINDING THE EXACT SOLUTIONS OF THE NONLINEAR DISPERSIVE EQUATIONS AND SEVENTH-ORDER SAWADA–KOTERA EQUATION
Authors: GANJI D. D. , JAMSHIDI N. , GANJI Z. Z.
Published: January 2009

In this paper, nonlinear dispersive equations and seventh-order Sawada–Kotera equation are solved using homotopy perturbation method (HPM) and variational iteration method (VIM). The results obtained by the proposed methods are then compared with that of Adomian decomposition method (ADM). The comparisons demonstrate that the two obtained solutions are in excellent agreement. The numerical results calculated show that the methods can be accurately implemented to these types of nonlinear equations. The results of HPM and VIM confirm the correctness of those obtained by Adomian decomposition method.
PROPAGATION OF SOLITARY WAVES ON LOSSY NONLINEAR TRANSMISSION LINES
Authors: KENGNE E. , VAILLANCOURT R.
Published: January 2009

We present a lossy nonlinear transmission RLC line and show how the coupled Ginzburg–Landau equations can be derived in the small amplitude and long wavelength limit using a standard reductive perturbation method and complex expansion. Soliton-like solution of the simplified equation was searched and the instability of a class of phase-winding solutions was explored.
THE EFFECTS OF DAMPING AND TEMPERATURE OF MEDIUM ON THE SOLITON EXCITED IN α-HELIX PROTEIN MOLECULES WITH THREE CHANNELS
Authors: PANG XIAO-FENG , LIU MEI-JIE
Published: January 2009

We studied numerically the influences of damping and temperature of medium on the properties of the soliton transported bio-energy in the α-helix protein molecules with three channels by using the dynamic equations in the improved Davydov theory and fourth-order Runge–Kutta method. From the simulation experiments, we see that the new solitons can move along the molecular chains without dispersion at a constant speed, in which the shape and energy of the soliton can remain in the cases of motion, whether short-time at T=0 or long time at T=300 K. In these motions, the soliton can travel over about 700 amino acid residues, thus its lifetime is, at least, 120 ps at 300 K. When the two solitons undergo a collision, they can also retain themselves forms to transport towards. These results are consistent with the analytic result obtained by quantum perturbed theory in this model. However, the amplitudes of the solitons depress along with increase of temperature of the medium, and it begins to disperse at 320 K. In the meanwhile, the damping of the medium can influence the states and properties of the soliton excited in α-helix protein molecules. The investigation indicates that the amplitude and propagated velocity of the soliton decrease, when the damping of medium increases. The soliton is dispersed at the large damping coefficient Γ=4 Γ0 at 300 K. The results show that the soliton excited in the α-helix protein molecules with three channels is very robust against the damping and thermal perturbation of medium at biological temperature of 300 K. Thus we can conclude that the soliton can play important part in the bio-energy transport and the improved model is possibly a candidate for the mechanism of the energy transport in the α-helix proteins.
RISK OF DISEASE-SELECTIVE PREDATION IN AN INFECTED PREY-PREDATOR SYSTEM
Authors: ALAM SHARIFUL
Published: January 2009

In this paper the mathematical model of disease-selective predation as proposed by Roy and Chattopadhyay10 is considered to identify the true risk of selective predation where the predator can recognize the infected prey and avoids those during predation. Furthermore, the model is modified by adding a discrete time delay in the term involving the gestation of prey by the predator and analyzed both numerically and analytically to review the risk factors.
BIOLOGICAL ORGANIZATION AND ANTI-ENTROPY
Authors: BAILLY FRANCIS , LONGO GIUSEPPE
Published: January 2009

This paper proposes a systemic perspective for some aspects of both phylogenesis and ontogenesis by expressing biological organization in terms of "anti-entropy", a notion to be defined below and which conceptually differs from the common use of "negative entropy". To this purpose, we introduce two principles, in addition to the thermodynamic ones, which are (mathematically) compatible with traditional principles but which have no meaning with regard to inert matter. A traditional balance equation for the metabolism will then be extended to the new notion as specified by these principles. We examine far from equilibrium systems and we focus in particular on the production of global entropy associated to the irreversible character of the processes. A close analysis of anti-entropy will be performed from the perspective of a diffusion equation of biomass over "complexity" and, as a complementary approach and as a tool for specifying a source term, in connection to Schrödinger's method regarding his equation in the field of Quantum Mechanics. We borrow only the operatorial approach from this equation and do so using a classical framework, since we use real coefficients instead of complex ones, thus falling outside of the mathematical framework of quantum theories. The first application of our proposal is a simple mathematical reconstruction of Gould's complexity curve of biomass over complexity as it applies to evolution. We then present, based on the existence of different time scales, a partition of ontogenetic time, in reference to entropy and anti-entropy variation. On the grounds of this approach, we analyze the metabolism and scaling laws. This allows to compare various relevant coefficients appearing in these scaling laws, which fit empirical data. Finally, a tentative and quantitative evaluation of complexity is proposed, also in relation to some empirical data (Caenorhabditis elegans).
ANGIOGENESIS MODEL WITH CARRYING CAPACITY DEPENDING ON VESSEL DENSITY
Authors: BODNAR MAREK , FORYŚ URSZULA
Published: January 2009

In this paper we consider a modification of the model of angiogenesis process proposed by Agur et al., in Discrete & Cont. Dyn. Sys. B4(1): 29–38, 2004. The number of steady states and their stability depending on the model parameters are studied. The hysteresis effect and cusp catastrophe are found for some parameters. The effect of hysteresis when the number of positive steady states changes from one to three is studied. The time delays are introduced. Numerical simulations, which show that oscillatory behaviour is possible, are performed.
SPATIAL PATTERN IN AN EPIDEMIC SYSTEM WITH CROSS-DIFFUSION OF THE SUSCEPTIBLE
Authors: SUN GUI-QUAN , JIN ZHEN , LIU QUAN-XING , LI LI
Published: January 2009

In this paper, pattern formation of a spatial model with cross diffusion of the susceptible is investigated. We compute Hopf and Turing bifurcations for the model. In particular, the exact Turing domain is delineated in the parameter space. When the parameters are in that domain, a series of numerical simulations reveals that the typical dynamics of the infecteds class typically involves the formation of isolated groups, i.e., striped, spotted or labyrinthine patterns. Furthermore, spatial oscillatory and anti-phase dynamics of different spatial points were also found. These results demonstrate that cross diffusion of susceptibles may have great influence on the spread of the epidemic.
APPROXIMATIONS FOR ALL-TO-ALL UNIFORM TRAFFIC GROOMING ON UNIDIRECTIONAL RINGS
Authors: BERMOND JEAN-CLAUDE , COUDERT DAVID , LEVEQUE BENJAMIN
Published: January 2009

Traffic grooming in a WDM network consists of assigning to each request (lightpath) a wavelength with the constraint that a given wavelength can carry at most C requests or equivalently a request uses 1/C of the bandwidth. C is known as the grooming ratio. A request (lightpath) needs two SONET add-drop multiplexers (ADMs) at each end node; using grooming, different requests can share the same ADM. The so called traffic grooming problem consists of minimizing the total number of ADMs to be used (in order to reduce the overall cost of the network). Here we consider the traffic grooming problem in WDM unidirectional rings which has been recently shown to be APX-hard and for which no constant approximations are known. We furthermore suppose an all to all uniform unitary traffic. This problem has been optimally solved for specific values of the grooming ratio, namely C = 2, 3, 4, 5, 6. In this paper we present various simple constructions for the grooming problem providing approximation of the total number of ADMs with a small constant ratio. For that we use the fact that the problem corresponds to a partition of the edges of the complete graph into subgraphs, where each subgraph has at most C edges and where the total number of vertices has to be minimized.
A NEW CONTOURLET-DOMAIN BASED IMAGE WATERMARKING SCHEME RESILIENT TO GEOMETRICAL ATTACKS
Authors: LOU OU-JUN , WANG XIANG-HAI , WANG ZHENG-XUAN
Published: January 2009

Coping with geometrical attacks in transform domain is crucial when we design a robust image watermarking scheme. In this paper, a novel contourlet-domain image watermarking scheme, which is robust to common signal processing and geometrical attacks, is proposed. First, the region with maximum energy in the directional subbands is considered for watermarking, i.e. the watermark can be embedded into the significant region as well as highly textured region of the host image. Then, for each coefficient of the selected subband, the strength factor was adaptively adjusted in terms of the energy of its parent and neighbor coefficients. Consequently, the tradeoff between the transparency and robustness of watermark can be achieved. Furthermore, the robust feature points, which can survive various signal processing and affine transformation, are extracted by using the Harris–Laplace detector. In watermark detection, the geometrical distortion of image is identified by using the feature template constructed during embedding phase, i.e. watermark resynchronization is performed. Experimental results show that the proposed watermark scheme is invisible and robust against common signal processing such as median filtering, sharpening, noise adding and JPEG compression, etc and geometrical attacks such as rotation, translation, scaling, row or column removal, shearing and local random bend, etc.
STEP-FLOW GROWTH OF HETEROEPITAXIAL SrRuO3 THIN FILMS ON 0.04° SrTiO3 (001) VICINAL SUBSTRATES
Authors: ZHU T. J. , YANG S. H. , CHEN X. , LIU X. X. , ZHAO X. B. , LU L. , LAI M. O.
Published: January 2009

We have grown epitaxial SRO thin films of thickness of about 50 nm on the STO (001) substrates with a small miscut angle of 0.04° by step-flow mode. A mode transition from two-dimensional mixed growth of layer-by-layer and step-flow growth to complete step-flow growth was observed, which is associated with the change in the surface mobility of adatoms and the rate of edge diffusion along the steps.
EFFECT OF NICKEL NIOBATE B-SITE PRECURSORS ON PHASE FORMATION, MICROSTRUCTURE AND DIELECTRIC PROPERTIES OF PEROVSKITE PNN CERAMICS
Authors: ANANTA S. , YIMNIRUN R. , KHAMMAN O.
Published: January 2009

Relaxor perovskite lead nickel niobate (PNN) ceramics were fabricated by using B-site precursor method, in which both columbite- NiNb 2 O 6 and corundum- Ni 4 Nb 2 O 9 were separately employed as nickel niobate B-site precursors. It has been found that optimization of sintering condition can successfully lead to highly dense and pure PNN ceramics in both routes. Between the two B-site precursor routes, pure perovskite PNN ceramics with slightly better densification and dielectric properties can be produced by using the columbite-route.
PATTERNING OF SURFACE ELECTRONIC PROPERTIES AND SELECTIVE SILVER DEPOSITION ON LiNbO3 TEMPLATE
Authors: LIU XIAOYAN , OHUCHI FUMIO , KITAMURA KENJI
Published: January 2009

This paper presents the work undertaken to understand chemical reactivity on LiNbO 3 surface induced by thermal change and optical irradiation to the crystal. Kelvin probe-based, electrostatic force microscopy is applied to map potential distribution on the surface of the LiNbO 3 with nanodomain structures fabricated using piezoresponse force microscopy. In-vacuum observation shows that the potential contrast and polarity of the nanodomain structures can be controlled by shifting temperature between 298 and 393 K. The measured potential difference between domains of opposite polarity suggests that surface adsorption plays a key role in potential formation. Upon ultraviolet irradiation, a preferential deposition of Ag particles on the +Z surfaces of LiNbO 3 becomes possible. We have inferred a mechanism by which photovoltaic effect causes the Ag particles to be deposited selectively on the +Z surfaces. The photovoltaic current density and ferroelectric crystal thickness appear to be fundamental parameters of the photocatalytic deposition.
SHAPE MEMORY PROPERTIES OF RAPIDLY SOLIDIFIED Ti50Ni50-XCuX (X = 20, 25) ALLOY STRIPS
Authors: KIM YEON WOOK , NAM TAE HYUN
Published: January 2009

The shape memory alloy strips of Ti 50 Ni 30 Cu 20 and Ti 50 Ni 25 Cu 25 have been fabricated by arc melt overflow technique. Their microstructures and shape memory characteristics were investigated by means of X-ray diffraction (XRD), optical microscopy and differential scanning calorimetry (DSC). The microstructure of the as-cast strips exhibited columnar grains normal to the strip surface. XRD analysis showed that the martensitic transformation of B2–B19 occurred in the alloy strips. During thermal cyclic deformation with the applied stress of 60 MPa, transformation hysteresis and elongation associated with the B2–B19 transformation were observed to be 4.9°C and 1.8% in Ti 50 Ni 30 Cu 20 alloy strip and 3.5°C and 1.7% in Ti 50 Ni 25 Cu 25 alloy strip. The as-cast strip of Ti 50 Ni 25 Cu 25 alloy also showed a perfect superelasticity and its stress hysteresis was as small as 14 MPa. These mechanical properties and shape memory characteristics of the alloy strips were ascribed to B2–B19 transformation and the controlled microstructures produced by rapid solidification of the arc melt overflow process.
FLEXOELECTRIC EFFECT IN FERROELECTRICS
Authors: MA WENHUI
Published: January 2009

Flexoelectric effect and its influence on the application of multifunctional ferroelectrics have been investigated. Theory of flexoelectric coupling has indicated that mechanical strain gradient can impact polarization in a way analogous to electric field. Experimentally, magnitudes of the flexoelectric coefficients have been measured in ferroelectric, incipient ferroelectric and relaxor ferroelectric perovskites. Present data of flexoelectricity suggests that such unconventional electromechanical coupling could make unique contribution to properly engineered ferroelectric thin films and nanostructures. Flexoelectric effect is expected to intensify at small dimensions and get large enough at nanoscale to significantly impact phase transition and functional response in ferroelectrics.
FLUX BRIDGMAN GROWTH OF FUNCTIONAL OXIDE SINGLE CRYSTALS
Authors: XU JIAYUE
Published: January 2009

The vertical Bridgman technique was an effective technique to grow congruent oxide crystals. However, it is difficult to grow incongruent crystals due to the erosion of the fluxes on seeds which was usually put at the bottom of the crucible. Recently, we developed a flux Bridgman growth process for some difficult-grown functional crystals, such as PZNT, ZnO and SLN. The properties of as-grown crystals were characterized and the crystal quality was evaluated. The results show that the flux Bridgman method is a potential approach to grow incongruent oxide crystals for industrial applications.
My Journey from Horticulture to Plant Biology
Authors: Zeevaart Jan A.D.
Published: January 2009

The author describes the circumstances and opportunities that led him to higher education and to pursue a research career in plant biology. He acknowledges the important roles a few individuals played in guiding him in his career. His early work on flowering was followed by studies on the physiological roles and the metabolism of gibberellins and abscisic acid. He describes how collaborations and technical developments advanced his research from measuring hormones by bioassay to their identification and quantification by mass spectrometry and cloning of hormone biosynthetic genes
Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part II)
Authors: Lemaux Peggy G.
Published: January 2009

Genetic engineering provides a means to introduce genes into plants via mechanisms that are different in some respects from classical breeding. A number of commercialized, genetically engineered (GE) varieties, most notably canola, cotton, maize and soybean, were created using this technology, and at present the traits introduced are herbicide and/or pest tolerance. In 2007 these GE crops were planted in developed and developing countries on more than 280 million acres (113 million hectares) worldwide, representing nearly 10% of rainfed cropland. Although the United States leads the world in acres planted with GE crops, the majority of this planting is on large acreage farms. In developing countries, adopters are mostly small and resource-poor farmers. For farmers and many consumers worldwide, planting and eating GE crops and products made from them are acceptable and even welcomed; for others GE crops raise food and environmental safety questions, as well as economic and social issues. In Part I of this review, some general and food issues related to GE crops and foods were discussed. In Part II, issues related to certain environmental and socioeconomic aspects of GE crops and foods are addressed, with responses linked to the scientific literature.
Aquilegia: A New Model for Plant Development, Ecology, and Evolution
Authors: Kramer Elena M.
Published: January 2009

The lower eudicot genus Aquilegia holds enormous potential for investigating aspects of development, ecology, and evolution that are otherwise unrepresented among existing model systems. Its evolutionary history is of particular interest because it represents a phylogenetic midpoint between models such as Arabidopsis and Oryza but, at the same time, has experienced a recent adaptive radiation within the genus. To take advantage of these features, a collaborative group has developed a number of genetic and genomic resources for Aquilegia that have facilitated the study of its distinct morphology. This work has demonstrated that although the petaloid sepals of Aquilegia do not depend on B-class genes for their identity, these loci do control development of the petals, stamens, and novel staminodium. Overall, Aquilegia stands as a key example of the potential utility and speed of developing new genetic model systems.
Roles of Proteolysis in Plant Self-Incompatibility
Authors: Zhang Yijing , Zhao Zhonghua , Xue Yongbiao
Published: January 2009

Self-incompatibility (SI) is a genetically controlled system adopted by many flowering plants to avoid inbreeding and thus to maintain species diversity. Generally, self-pollen rejection occurs through active pollen and pistil recognition and subsequent signaling responses. So far, three different molecular controls of pollen and pistil recognition have been characterized and are exemplified by three families: the Solanaceae, the Papaveraceae, and the Brassicaceae. With more components involved in these SI systems coming to light, recent studies have provided intriguing insights into the downstream reactions that follow the initial SI signal perception. The process of pollen rejection is closely associated with rapid and effective proteolytic events, including the ubiquitin-proteasome pathway and the vacuolar sorting pathway. Here, we review our current understanding of the roles of proteolysis in SI responses of flowering plants.
Laryngeal constriction during hypoxic gasping and its role in improving autoresuscitation in two mouse strains
Authors: Song Z. , Harris K. A. , Thach B. T.
Published: January 2009

Laryngeal closure following hypoxic gasps has been documented, but its efficacy in improving autoresuscitation capacity is unknown. We studied SWR/J mice who normally cannot autoresuscitate and the C57/BLJ strain who can. We evaluated the effects of elevated end-inspiratory lung volume immediately following a gasp. We compared upper airway-intact mice with tracheostomized mice in which the vocal cords are bypassed. We used the techniques of repeated autoresuscitate trials to test autoresuscitation capability. Both SWR/J and C57/BLJ mice could maintain elevated lung volume immediately after a gasp (breath holding). Such breath holding increased autoresuscitation ability in C57/BLJ mice but did not in SWR/J mice. In SWR/J mice, the duration of the breath holds was less than that in the C57/BLJ mice. These findings indicate that gasp-associated breath holding improves autoresuscitation capability during repeated autoresuscitation trials. Also, they show that SWR/J mice have a deficiency in central nervous system mechanisms regulating glottic closure during hypoxic gasping.
Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle
Authors: Coffey Vernon G. , Pilegaard Henriette , Garnham Andrew P. , O'Brien Brendan J. , Hawley John A.
Published: January 2009

We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men [22.9 ± 6.3 yr, body mass of 73.2 ± 4.5 kg, peak O2 uptake (V̇o2peak) of 54.0 ± 5.7 ml·kg−1·min−1] were randomly assigned to complete trials consisting of either resistance exercise (8 × 5 leg extension, 80% 1 repetition maximum) followed by a bout of endurance exercise (30 min cycling, 70% V̇o2peak) or vice versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout, and after 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1Ser473 were elevated 15 min after resistance exercise compared with cycling, with the greatest increase observed when resistance exercise followed cycling (∼55%; P < 0.01). TSC2-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (−42%), whereas muscle ring finger mRNA was elevated when cycling was undertaken after resistance exercise (∼52%; P < 0.05). The hexokinase II mRNA level was higher after resistance cycling (∼45%; P < 0.05) than after cycling-resistance exercise, whereas modest increases in peroxisome proliferator-activated receptor gamma coactivator-1α mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates acute “interference.”
Human muscle protein synthesis and breakdown during and after exercise
Authors: Kumar Vinod , Atherton Philip , Smith Kenneth , Rennie Michael J.
Published: January 2009

Skeletal muscle demonstrates extraordinary mutability in its responses to exercise of different modes, intensity, and duration, which must involve alterations of muscle protein turnover, both acutely and chronically. Here, we bring together information on the alterations in the rates of synthesis and degradation of human muscle protein by different types of exercise and the influences of nutrition, age, and sexual dimorphism. Where possible, we summarize the likely changes in activity of signaling proteins associated with control of protein turnover. Exercise of both the resistance and nonresistance types appears to depress muscle protein synthesis (MPS), whereas muscle protein breakdown (MPB) probably remains unchanged during exercise. However, both MPS and MPB are elevated after exercise in the fasted state, when net muscle protein balance remains negative. Positive net balance is achieved only when amino acid availability is increased, thereby raising MPS markedly. However, postexercise-increased amino acid availability is less important for inhibiting MPB than insulin, the secretion of which is stimulated most by glucose availability, without itself stimulating MPS. Exercise training appears to increase basal muscle protein turnover, with differential responses of the myofibrillar and mitochondrial protein fractions to acute exercise in the trained state. Aging reduces the responses of myofibrillar protein and anabolic signaling to resistance exercise. There appear to be few, if any, differences in the response of young women and young men to acute exercise, although there are indications that, in older women, the responses may be blunted more than in older men.
The Brachial Artery Remodels to Maintain Local Shear Stress Despite the Presence of Cardiovascular Risk Factors
Authors: Chung William B. , Hamburg Naomi M. , Holbrook Monika , Shenouda Sherene M. , Dohadwala Mustali M. , Terry Dellara F. , Gokce Noyan , Vita Joseph A.
Published: January 2009

Objective—

Under physiological conditions, arteries remodel in response to changes in blood flow to maintain local shear stress. Risk factors and developing atherosclerosis may be associated with maladaptive remodeling that produces relatively large arteries with low levels of shear stress. Recent studies have shown that the brachial artery and other peripheral arteries are enlarged in patients with risk factors and cardiovascular disease, and we tested the hypothesis that this finding represents maladaptive remodeling.

Methods and Results—

We measured brachial artery diameter and flow by ultrasound and calculated shear stress in a diverse cohort of 1583 subjects (age 53±17 years, 62% male, and 51% with coronary artery disease and/or peripheral arterial disease). In a stepwise linear regression model, age (
P
<0.001), gender (
P
<0.001), body mass index (
P
<0.001), hypertension (
P
=0.005), and hypercholesterolemia (
P
=0.02) were associated with larger brachial diameter. Older age was associated with lower shear stress (
P
<0.01), consistent with maladaptive remodeling. However, body mass index, hypertension, hypercholesterolemia, and prevalent atherosclerosis were associated with proportionate changes in blood flow and no difference in shear stress compared to reference groups, suggesting adaptive remodeling.

Conclusions—

These findings suggest that enlargement of the brachial artery in the setting of obesity, hypertension, hypercholesterolemia, and atherosclerosis reflects adaptive remodeling. The results provide further support for the concept that arterial remodeling is an important homeostatic response that is maintained despite the presence of risk factors and developing atherosclerosis.
Leukotriene Receptor Antagonism and the Prevention of Extracellular Matrix Degradation During Atherosclerosis and In-Stent Stenosis
Authors: Hlawaty Hanna , Jacob Marie-Paule , Louedec Liliane , Letourneur Didier , Brink Charles , Michel Jean-Baptiste , Feldman Laurent , Bäck Magnus
Published: January 2009

Objective—

The lipid-derived inflammatory mediators leukotrienes (LTs) are produced during vascular injury. The aim of the present study was to determine the role of LT receptor signaling in the pathophysiology of in-stent stenosis.

Methods and Results—

New Zealand White rabbits were fed 0.3% cholesterol and subjected to angioplasty with balloon dilatation and stent implantation in the right carotid artery. Rabbits treated for 2 weeks with the BLT receptor antagonist BIIL284 (3 mg/kg once daily by oral gavage) displayed a significantly reduced in-stent intimal hyperplasia in carotid arteries compared with vehicle-treated rabbits. In addition, BIIL284 treatment significantly reduced the extracellular matrix metalloproteinase (MMP)-2 and MMP-9 activities in stented arteries. The inhibited MMP-9 activity was correlated with decreased macrophage content in the lesions. The LTB
4
-induced migration of vascular smooth muscle cells was significantly inhibited by transfection with siRNA against MMP-2. Finally, human arteries subjected to ex vivo angioplasty and stent implantation displayed an increased in-stent intimal hyperplasia and higher MMP-2 and -9 activities in the presence of LTB
4
.

Conclusions—

These results suggest a key role of LT signaling in the extracellular matrix degradation associated with hyperlipidemia and in-stent stenosis. In conclusion, targeting LT receptors may represent a therapeutic strategy in atherosclerosis and interventional cardiology.
Critical Role of Tissue Kallikrein in Vessel Formation and Maturation
Authors: Stone Oliver A. , Richer Christine , Emanueli Costanza , van Weel Vincent , Quax Paul H.A. , Katare Rajesh , Kraenkel Nicolle , Campagnolo Paola , Barcelos Luciola S. , Siragusa Mauro , Sala-Newby Graciela B. , Baldessari Danila , Mione Marina , Vincent Marie P. , Benest Andrew V. , Al Haj Zen Ayman , Gonzalez Julien , Bates David O. , Alhenc-Gelas Francois , Madeddu Paolo
Published: January 2009

Objective—Human Tissue Kallikrein (hKLK1) overexpression promotes an enduring neovascularization of ischemic tissue, yet the cellular mechanisms ofhKLK1-induced arteriogenesis remain unknown. Furthermore, no previous study has compared the angiogenic potency ofhKLK1, with its loss of function polymorphic variant, rs5515 (R53H), which possesses reduced kinin-forming activity.

Methods and Results—Here, we demonstrate thattissue kallikreinknockout mice (KLK1−/−) show impaired muscle neovascularization in response to hindlimb ischemia. Gene-transfer of wild-typeAd.hKLK1but notAd.R53H-hKLK1was able to rescue this defect. Similarly, in the rat mesenteric assay,Ad.hKLK1induced a mature neovasculature with increased vessel diameter through kinin-B2receptor-mediated recruitment of pericytes and vascular smooth muscle cells, whereasAd.R53H-hKLK1was ineffective. Moreover,hKLK1but notR53H-hKLK1overexpression in the zebrafish induced endothelial precursor cell migration and vascular remodeling. Furthermore,Ad.hKLK1activates metalloproteinase (MMP) activity in normoperfused muscle and fails to promote reparative neovascularization in ischemicMMP9−/−mice, whereas its proarteriogenic action was preserved inApoE−/−mice, an atherosclerotic model of impaired angiogenesis.

Conclusions—These results demonstrate the fundamental role of endogenous Tissue Kallikrein in vascular repair and provide novel information on the cellular and molecular mechanisms responsible for the robust arterialization induced byhKLK1overexpression.
Soluble Flt-1 Gene Transfer Ameliorates Neointima Formation After Wire Injury in flt-1 Tyrosine Kinase–Deficient Mice
Authors: Koga Jun-ichiro , Matoba Tetsuya , Egashira Kensuke , Kubo Mitsuki , Miyagawa Miho , Iwata Eiko , Sueishi Katsuo , Shibuya Masabumi , Sunagawa Kenji
Published: January 2009

Objective—

We have demonstrated that vascular endothelial growth factor (VEGF) expression is upregulated in injured vascular wall, and blockade of VEGF inhibited monocyte infiltration and neointima formation in several animal models. In the present study, we aimed to clarify relative role of two VEGF receptors, flt-1 versus flk-1/KDR, in neointima formation after injury using flt-1 tyrosine kinase-deficient (Flt-1 TK
−/−
) mice and soluble Flt-1(sFlt-1) gene transfer.

Methods and Results—

Neointima formation was comparable between wild-type and Flt-1 TK
−/−
mice 28 days after intraluminal wire injury in femoral arteries. By contrast, neointima formation was significantly suppressed by sFlt-1 gene transfer into Flt-1 TK
−/−
mice that blocks VEGF action on flk-1 (intima/media ratio: 2.8±0.4 versus 1.4±0.4,
P
<0.05). The inhibition of neointima formation was preceded by significant reduction of monocyte chemoattractant protein (MCP-1) expression in vascular smooth muscle cells (VSMCs) and monocyte infiltration 7 days after injury. Gene transfer of sFlt-1 or treatment of flk-1–specific antibody significantly inhibited VEGF-induced MCP-1 expression determined by RT-PCR in cultured aortic tissue and VSMCs. MCP-1–induced chemotaxis was equivalent between wild-type and Flt-1 TK
−/−
mice.

Conclusions—

These results suggest that endogenous VEGF accelerates neointima formation through flk-1 by regulating MCP-1 expression in VSMCs and macrophage-mediated inflammation in injured vascular wall in murine model of wire injury.