bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex Interactions between Fish and Zooplankton: Quantifying the Role of an Open-Water Planktivore
Authors: DeVries Dennis R. , Stein Roy A.
Published: February 2009

An open-water planktivore, the gizzard shad (Dorosoma cepedianum), can drive complex interactions among fish and zooplankton in Ohio reservoirs. In Kokosing Lake, crustacean zooplankton density declined to near zero immediately after larval gizzard shad abundance peaked during 1987 and 1988. This decline can be attributed to increased death rates, due to predation, and to reduced number of eggs per cladoceran. In an enclosure/exclosure experiment, young-of-year gizzard shad at lake densities significantly reduced density of crustacean zooplankton and rotifers within 2 wk. In addition, phytoplankton that were edible to zooplankton were reduced in enclosures, likely due to a combination of direct herbivory by gizzard shad and reduced nutrient availability due to uptake by the growing gizzard shad. Gizzard shad not only directly influenced zooplankton via predation, they also indirectly affected zooplankton by reducing phytoplankton abundance. Because larval bluegill (Lepomis macrochira) migrated to the limnetic zone during or shortly after the zooplankton decline, food available to these zooplanktivorous larvae, as well as their ultimate recruitment, was reduced with gizzard shad. Through direct (i.e. predation) and indirect (i.e. influencing algal abundance) pathways, gizzard shad can drive zooplankton to extinction, thereby reducing recruitment of other fishes and controlling community composition.
Response of a Subarctic Lake Chain to Reduced Sewage Loading
Authors: Choulik O. , Moore T. R.
Published: February 2009

Changes in total phosphorus (TP), chlorophyll a (Chl a), and total nitrogen (TN) concentrations were monitored in a lake chain in northern Quebec to which sewage loading had been reduced by about 80% over 8 yr. Summer concentrations of TP and Chl a fell by 70 and 78%, respectively, in Lake Pearce, the uppermost lake most affected by eutrophication. Reductions in the two downstream lakes were 64 and 55% for TP and 45% for Chl a. The rapid response of the lakes to reduced sewage loading is related to the short residence time of water (60 d in winter to 2 d during snowmelt in Lake Pearce). Sediments in Lake Pearce showed thick (20–70 cm) accumulations of soft, organic-rich material (loss on ignition 10–50%), containing 4–20 mg P∙g−1; however, winter P release rates were small (about 0.2 mg P∙m−2∙d−1), possibly associated with the Fe-rich nature of the sediments. Although anoxic conditions still develop under the thick ice cover (1 m), the depth and intensity are less than before sewage reduction. Reductions in TP have been accompanied by increases in TN and TN:TP ratios (from < 10:1 to > 30:1), suggesting that there has been a shift from N to P limitation.
Assessment of Crab Limb Regeneration as an Assay for Developmental Toxicity
Authors: Clare Anthony S. , Costlow John D. , Bedair Hassan M. , Lumb George
Published: February 2009

The regeneration of a cheliped that is autotomised at the final larval stage, the megalopa, of the mud crab Rhithropanopeus harrisii (Gould) forms the basis of an assay for developmental toxicity. Cheliped regeneration is followed through to the third juvenile crab stage; a regenerate that is approximately two thirds full size normally emerges at the moult to the second crab, and full size is attained at crab 3. The absence of a regenerate at crab 2, or a regenerate that is smaller than normal and/or malformed, is scored as abnormal regeneration. Other parameters examined in this assay include survival and duration of development. The assay is of comparatively short duration (approximately 2 wk), and survival is high following autotomy under optimal conditions. Four insecticides and a herbicide have been tested in the assay at lethal and sublethal concentrations. Of these compounds, methomyl, carbofuran, and alachlor induced abnormal regeneration whereas cypermethrin and RH 5849 did not affect regeneration at the concentrations tested. Although reproducibility of results needs improvement, crab limb regeneration is otherwise a practical assay for developmental toxicity.
Evidence of creep in steep natural slopes of Champlain Sea clay
Authors: Eden W. J.
Published: February 2009

Three types of evidence of deep seated creep of steep natural slopes are considered: surface manifestations such as fissures and depressions; inclinometer measurements on three slopes in the Ottawa area; and movements of a bridge superstructure spanning a steep sided ravine.Results of measurements show that the movements are not continuous but occur in response to seasonal high levels of the groundwater table. The implications of the movements are discussed in relation to the stability of clay slopes.
Morphological variation of tracheids in the bolewood of mature Piceaengelmannii and Pinuscontorta
Authors: France Raymond C. , Mexal John G.
Published: February 2009

Variations in tracheid morphology with changes in height were examined for the bolewood of Piceaengelmannii Parry and Pinus contorta Dougl. ex Loud. Fiber length increased with increasing height to midbole, then decreased with further increases in height. Age and(or) height influenced maximum fiber length, but crown characteristics and species did not. Cell wall thickness varied independently of height in the bole. Both radial and tangential lumen diameter, lumen area, and lumen diameter to cell diameter (l/D) ratio responded to tree height similar to fiber length. Pit pore size of Engelmann spruce also varied in this manner. Collapsing force was determined from morphological information and was found to decrease to a minimum at midbole and then increase to the top of the tree.
Spatial and seasonal dietary patterns of the desert horned lizard (Phrynosoma platyrhinos): harvester ant specialist or generalist ant feeder?
Authors: Newbold T.A. Scott , MacMahon James A.
Published: February 2009

A suite of factors including prey availability and prey defenses influence prey selection by consumers and ultimately define an animal’s feeding strategy (e.g., generalist or specialist). Here we examined the relationship between availability and selection of ants by the desert horned lizard ( Phrynosoma platyrhinos Girard, 1852) to test the hypothesis that P. platyrhinos are specialist predators on harvester ants, and to investigate which factors influence the prey preference of lizards. Variation in ant availability and lizard diets was assessed using 83 plots established along a Great Basin shrub–steppe bajada in northwestern Utah, USA. Across the study site, 14 of 20 ant species were represented in the lizard diet. However, 70% of that diet consisted of just two species. In contrast to previous studies, P. platyrhinos did not show a disproportionate preference for harvester ants. Instead, larger ants of any species (including harvester ants) were preferentially selected over medium-sized and smaller ants. These findings suggest that desert horned lizards demonstrate an opportunistic feeding strategy in which lizards select ants based on their body size and abundance. More generally, these results emphasize the importance of assessing predator response across naturally varying gradients in prey availability to evaluate feeding specialization.
The seasonality of reproduction in photoperiod responsive and nonresponsive northern red-backed voles (Myodes rutilus) in Alaska
Authors: Stevenson K.T. , van Tets I.G. , Nay L.A.I.
Published: February 2009

High-latitude arvicoline rodents usually reproduce in warmer months, but winter breeding has been documented in several species, including the northern red-backed vole ( Myodes rutilus (Pallas, 1779) Wilson and Reader, 2005; formerly Clethrionomys rutilus (Pallas, 1779)). We tested whether the reproductive condition of the species is linked to changes in environmental parameters or its body condition, and we tested the frequencies at which different reproductive phenotypes are exhibited under field and laboratory conditions. Free-living voles in south-central Alaska reached peak reproductive organ masses in spring (females) and early summer (males). Between-subject comparisons showed an effect of body mass, photoperiod, percent fat, temperature, and snow depth on reproductive organ masses, depending on the sex and breeding period (p < 0.05). One instance of late-summer photoperiod nonresponsiveness was observed, but we detected no winter breeding. Captive male voles given food ad libitum and housed at room temperature exhibited strong phenotypic variation in testis mass in response to short photoperiods. The percentage of nonresponders was 28.2% and was within the known range of nonresponsiveness for lower latitude species (20%–40%). Thus, photoperiod nonresponsive morphs are conserved in at least one arctic and subarctic species at frequencies comparable to lower latitude voles despite no observance of winter breeding in the field. Voles exhibit reproductive elasticity and may breed in winter if environmental conditions enable them.
Activity budgets and sociality in a monomorphic ungulate: the African oryx (Oryx gazella)
Authors: Ruckstuhl K. E. , Neuhaus P.
Published: February 2009

Sexual size dimorphism in ruminants is associated with social and (or) habitat segregation, while monomorphic species often live alone, in monogamous pairs, or in mixed-sex groups. Most research on sexual differences in behaviour has been done on sexually size-dimorphic ruminants, whereas little is known about monomorphic species. We tested the activity budget hypothesis which predicts that similar-sized individuals should have similar activity budgets, while dissimilarly sized individuals should differ in their behaviours. We studied African oryx ( Oryx gazella (L., 1758)), which are size-monomorphic, to investigate how age, sex, or reproductive state affect their foraging behaviour. We expected that males and females have similar activity budgets, except for lactating females who were expected to spend slightly more time foraging. Younger, smaller animals were predicted to differ in their activity budgets from adults, owing to high energy demands. We predicted that air temperature, vegetation height, and group sizes would be more important in shaping activity budgets and feeding rates than sex or reproductive differences. The sexes did not differ in their behaviour, while subadults spent less time active than adults. Temperature and vegetation height significantly affected their behaviour. We discuss the importance of environmental, as well as intrinsic, factors when studying sexual differences in behaviour and habitat use.
CONSISTENCY CONDITION OF SPHERICALLY SYMMETRIC SOLUTIONS IN f(R) GRAVITY
Authors: SAFFARI REZA , RAHVAR SOHRAB
Published: February 2009

In this work we study the spherical symmetric solutions of f(R) gravity in the metric formalism. We show that for a generic f(R) gravity, the spherical symmetric solution is consistent with the modified gravity equations except in the case of imposing an extra condition for the metric.
THE LONG-RANGE INTERACTION IN MASSLESS (λΦ4)4THEORY
Authors: STEVENSON P. M.
Published: February 2009

Does massless (λΦ4)4theory exhibit spontaneous symmetry breaking (SSB)? The raw one-loop result implies that it does, but the "RG-improved" result implies the opposite. We argue that the appropriate "low-energy effective theory" is a nonlocal field theory involving an attractive, long-range interaction Φ2(x)Φ2(y)/|x-y|4. RG improvement then requires running couplings for both this interaction and the original pointlike interaction. A crude calculation in this framework yields SSB even after "RG improvement" and closely agrees with the raw one-loop result.
STABILITY OF THE VACUUM AND DIELECTRIC MODEL OF CONFINEMENT IN QCD
Authors: FUKUDA REIJIRO
Published: February 2009

After the gauge invariant gluon condensation, gluons remain as massless excitations. When the effective theory describing the condensation and the excitation is constructed, a constraint has to be imposed for the vacuum to be stable. The constraint implies the perfect dia-electricity and assures the solution of color flux tube when quarks are introduced. Thus the dia-electric model of Kogut–Susskind and 't Hooft is derived by the stability of the condensed vacuum.
STUDYING STRANGE MESON PRODUCTION WITH FOPI
Authors: HARTMANN OLAF N.
Published: February 2009

The production of mesons containing strangeness is studied using elementary and heavy-ion probes with the FOPI detector at GSI-SIS. The observed inclusive cross section of neutral kaons points to an in-medium modification in the production. The momentum dependent ratio of cross sections of light and heavy target nuclei turns out to be a sensitive observable for the in-medium potential strength in transport codes. The experiments will continue studying the production of charged kaons with elementary probes including the search for deeply bound antikaon nuclear clusters in proton proton collisions.
EXCLUSIVE PRODUCTION AT THE TEVATRON AND THE LHC
Authors: PINFOLD JAMES L.
Published: February 2009

We present the current status of the study at the Tevatron, of the exclusive processes: [Formula: see text] and [Formula: see text], produced via two photon interactions; [Formula: see text], [Formula: see text] and [Formula: see text] from Double Pomeron Exchange (DPE); and, [Formula: see text], [Formula: see text] and [Formula: see text]; from photon-pomeron fusion (photoproduction). In closing we briefly discuss the plans for, and benefits of, studying exclusive physics at the LHC.
THREE-NUCLEON INTERACTION DYNAMICS STUDIED VIA THE DEUTERON-PROTON BREAKUP
Authors: STEPHAN E. , KISTRYN St. , KALANTAR-NAYESTANAKI N. , BIEGUN A. , BODEK K. , CIEPAŁ I. , DELTUVA A. , EPELBAUM E. , ESLAMI-KALANTARI M. , FONSECA A. C. , GLÖCKLE W. , GOLAK J. , JHA V. , KAMADA H. , KIRILLOV DA. , KIRILLOV DI. , KIS M. , KLICZEWSKI St. , KŁOS B. , KOZELA A. , KRAVCIKOVA M. , KYRYANCHUK V. M. , LESIAK M. , MACHNER H. , MAGIERA A. , MAHJOUR-SHAFIEI M. , MARTINSKA G. , MESSCHENDORP J. , MICHERDZIŃSKA A. , NOGGA A. , PISKUNOV N. , PROTIC D. , RAMAZANI A. , VON ROSSEN P. , ROY B. J. , SAKAI H. , SAUER P. U. , SEKIGUCHI K. , SITNIK I. , SIUDAK R. , SKIBIŃSKI R. , SWORST R. , URBAN J. , WITAŁA H. , ZEJMA J. , ZIPPER W.
Published: February 2009

A large set of high precision cross sections, vector Ax, Ay and tensor Axx, Axy, Ayy analyzing powers for the [Formula: see text] breakup reaction were measured at 130 MeV beam energy with the detection system covering a large part of the phase space. Results are compared with rigorous theoretical calculations employing various models of the three-nucleon system dynamics. The cross section data allowed to establish evidence for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force in the breakup reaction. Analyzing power data are generally quite well described by theoretical predictions even with pure NN interactions. However, in some regions discrepancies has been observed for tensor analyzing powers, only rarely cured by inclusion of the three nucleon force. This indicates incompletness of the present-day treatment of the spin part of three nucleon system dynamics.
SOME PROPERTIES OF THE CENTRAL π--MESON CARBON INTERACTIONS AT 40 GeV/c
Authors: SULEYMANOV M. K. , KHAN E. U. , AHMED K. , HASEEB M. Q. , TAHIR F. , HUSEYNALIYEV Y. H. , AJAZ M. , KHAN K. H. , WAZIR Z.
Published: February 2009

We discuss some properties of the central π--meson carbon reactions at 40 GeV/c. While these results were obtained many years ago they have not been explained completely. We attempt to interpret following: results regime change on the behavior of some characteristics of the events as a function of the centrality; anomaly peak on the angular distributions of the slow protons emitted in these reactions; charge asymmetry on the π--mesons production in the back hemisphere in lcs.

Understanding of the results could help to explain the new ones coming from the modern central experiments at high and ultrarelativistic energies.
SYMPLECTIC NO-CORE SHELL MODEL
Authors: DRAAYER JERRY P. , DYTRYCH TOMÁŠ , SVIRATCHEVA KRISTINA D. , BAHRI CHAIRUL , VARY JAMES P.
Published: February 2009

The symplectic no-core shell model (Sp-NCSM) is described. The theory is applied to a study of the structure of 12 C and 16 O . Results from a full 6ħΩ NCSM calculation for low-lying states in these nuclei using a realistic nucleon-nucleon interaction are found to project at approximately the 90% level onto a few of the leading 0 p -0 h and 2 p -2 h symplectic representations. The results are nearly independent of the oscillator strength parameter and whether bare or renormalized effective interactions are used in the analysis. The Sp-NCSM model space is typically only a very small fraction (under 1%) of the NCSM space, and grows slowly with increasing ħΩ. The comparisons with NCSM results suggest either the effective nucleon-nucleon interaction possesses a heretofore unappreciated symmetry, namely Sp(3,R) and the complementary (spin-isospin) supermultiplet symmetry, or the nuclear many-body system acts as a filter that allows the symplectic symmetry to propagate in a coherent way into the many-body dynamics while tending to dampen out symplectic symmetry breaking terms. Also, since the Sp-NCSM is a multi-ħΩ generalization of the Elliott SU (3) model, the results obtained to date reaffirm the relevance of SU (3) to atomic nuclei.
MULTI-MAJOR-SHELL SHELL MODEL FOR HEAVY NUCLEI–AN EXTENDED PROJECTED SHELL MODEL
Authors: SUN YANG , WU CHENG-LI
Published: February 2009

The projected shell model (PSM) in its original version is an efficient shell model truncation scheme for well deformed nuclei. However, the model is applicable only to rotational motion, but not collective vibrations. In this paper, we discuss a scheme that extends the PSM applicability to low-lying rotational and vibrational states possibly in all kinds of heavy nuclei (from deformed via transitional to spherical), thus rendering it to be a more general multi-major-shell shell model for heavy nuclei. Three known types of vibration (β, γ, and scissors-mode) are discussed.
IMAGE RECONSTRUCTION BASED ON COMBINATION OF WAVELET DECOMPOSITION, INPAINTING AND TEXTURE SYNTHESIS
Authors: CHEN HUAWEI , HAGIWARA ICHIRO , TIEU A. KIET
Published: February 2009

Digital inpainting provides a means for reconstruction of damaged portions of an image. Although the inpainting basics are straightforward, most inpainting techniques published in the literature are only suitable for remarkable small portion or smooth color image. In order to avoid such shortcomings, we present a new algorithm for digital reconstruction based on combination of wavelet decomposition, surface-based/PDE-based inpainting and texture synthesis. In this algorithm, wavelet transform firstly decomposes the image into high frequency and low frequency level parts. Subsequently, CSRBF which is generally used for surface interpolation or PDE-based inpainting is employed for low frequency level and texture synthesis is used for high frequency level. It results in that not only slight portion but also the common blotched image can be reconstructed with high quality. Especially, our algorithm makes large-size blotched image possible and becomes more efficient as compared to individual PDE-based and CSRBF approaches.
A NONLINEAR FILTERING BASED OPTICAL FLOW COMPUTATION
Authors: ZONGQING LU , QINGMIN LIAO , JIHONG PEI
Published: February 2009

A novel optical flow estimation is proposed in this paper, which addresses some issues including the credible estimation of optical flow and the prevention of over-smoothing across motion boundaries. Our main contribution is that we estimated the optical flow by a nonlinear filtering process instead of an energy minimizing process, the latter often needs the corresponding smoothing constraint to be restricted to some form of convex and differentiable entity. In this way, it avoids some restrictions needed by the regularization. So we can choose a nonlinear filter from more flexible forms, which can help to deal with flow discontinuities more efficiently in some sense. We modified and extended a scalar 2D bilateral filter to optical flow field as the wanted nonlinear filter. Qualitative and quantitative results show that the new method can produce a reliable result.
PHOTOCATALYTIC DEGRADATION OF PYRENE IN POROUS Pt/TiO2–SiO2 PHOTOCATALYST SUSPENSION UNDER UV IRRADIATION
Authors: LUO ZHAOHUI , KATAYAMA-HIRAYAMA KEIKO , HIRAYAMA KIMIAKI , AKITSU TETSUYA , KANEKO HIDEHIRO
Published: February 2009

Pyrene is a high molecular weight polycyclic aromatic hydrocarbon (PAH) that is found in water systems worldwide. It is harmful to living organisms, even when taken in very small amounts. The photocatalytic degradation of pyrene in porous Pt / TiO 2– SiO 2 photocatalyst (PPtPC) suspension under UV irradiation was investigated in this study. PPtPC was prepared by a simple heat treatment of the compacted powder mixtures of anatase TiO 2 and amorphous SiO 2 with camphor as a pore directing template, followed by coating platinum by the dip-coating method. X-ray diffraction (XRD), scanning electron microscopy (SEM) with an integrated energy-dispersive analysis of the X-ray (EDX) system, and Brunauer–Emmett–Teller (BET) were used to characterize PPtPC. The degradation kinetics of pyrene in different experimental conditions, such as initial concentration of pyrene, oxygen concentrations, pH, and temperature, were investigated. The durability of PPtPC was also tested. The results indicate that the structure of TiO 2 in PPtPC is anatase. The aggregated size of PPtPC is in the range of 10–100 μm, the mean pore diameter is 3 nm, and the BET surface area is 109 m2 g-1. The photocatalytic degradation process of pyrene follows pseudo-first-order kinetics. The rate constants increase as the initial concentration of pyrene and pH decrease. Higher temperature slightly enhances the rate constant. The dissolved oxygen in the photocatalytic degradation process is not as important as in the photolysis process. The recovered PPtPC still shows high photoactivity. This work suggests that PPtPC offers a promising method for high molecular weight PAH removal.
COMPARISON OF THE REACTIVITY OF NANOSIZED ZERO-VALENT IRON (nZVI) PARTICLES PRODUCED BY BOROHYDRIDE AND DITHIONITE REDUCTION OF IRON SALTS
Authors: SUN QUAN , FEITZ ANDREW J. , GUAN JING , WAITE T. DAVID
Published: February 2009

Dithionite can be used to reduce Fe (II) and produce nanoscale zero-valent iron (nZVI) under conditions of high pH and in the absence of oxygen. The nZVI is coprecipitated with a sulfite hydrate in a thin platelet. The nanoparticles formed are not pure iron but this feature does not appear to affect their degradation performance under air or N 2 gas conditions. The efficiency of trichloroethylene (TCE) degradation, when one is employing nanoparticles manufactured using dithionite ( nZVI S 2 O 4), is similar to if not slightly better than that of the more conventional borohydride procedure ( nZVI BH 4). The other advantages of the dithionite method are that (i) it uses a less expensive and widely available reducing agent, and (ii) there is no production of potentially explosive hydrogen gas. Oxidation of benzoic acid using the nZVI S 2 O 4 particles results in different byproducts than those produced when nZVI BH4 particles are used. The low oxidant yield based on hydroxybenzoic acid generation is offset by the production of higher concentrations of phenol. The high concentration of phenol compared to hydroxybenzoic acids suggests that OH • addition is not the primary oxidation pathway when one is using the nZVI S 2 O 4 particles. It is proposed that sulfate radicals ([Formula: see text]) are produced as a result of hydroxyl radical attack on the sulfite matrix surrounding the nZVI S 2 O 4 particles, with these radicals oxidizing benzoic acid via electron transfer reactions rather than addition reactions.
GROWTH RATE MEASUREMENT OF C60 FULLERENE NANOWHISKERS
Authors: HOTTA KAYOKO , MIYAZAWA KUN'ICHI
Published: February 2009

The growth rate of C 60 fullerene nanowhiskers ( C 60NWs) prepared by the liquid–liquid interfacial precipitation method is measured and the growth mechanism is discussed. The growth of C 60NWs is investigated from the data obtained at the growth temperatures of 5, 10, 15 and 20°C. It is found that the convection of the solution scarcely influences the growth rate, suggesting that a surface reaction of C 60 molecules dominates the growth process. The activation energy of C 60NWs' growth is estimated at about 52.8 kJ/mol from their initial stage of growth. This activation energy is much greater than that of C 60 diffusion in solutions found in the literature. This result suggests that the desolvation process of C 60 on the whisker surface governs the growth of C 60NWs.
FORMATION OF ZnO NANOBRUSHES IN DIRECT ATMOSPHERE USING A CARBON CATALYST AND A Zn METAL SOURCE
Authors: SINGH SHUBRA , REDDY S. BHASKAR , KOTTAISAMY M. , RAO M. S. RAMACHANDRA
Published: February 2009

In this paper we report on the preparation of nanobrushes of ZnO on quartz substrate by a direct atmosphere evaporation method using Zn metal flakes. Activated charcoal was used as a catalyst that facilitated the formation of nanobrushes in which the brush stem was about 15–20 μm in length and the bristles (100–200 nm thick) were made up of nanofibrous ZnO whose tips were 10–15 nm in width and were angled in some cases. These aligned nanobrushes can find potential applications as nanopower generators and high aspect ratio AFM probes by virtue of the piezoelectric property of ZnO . This technique is simple for realizing aligned ZnO nanobrushes with metallic Zn as the source material.
SYNTHESIS AND MICROSTRUCTURE OF A NOVEL TiO2 AEROGEL–TiO2 NANOWIRE COMPOSITE
Authors: SUZUKI YOSHIKAZU , BERGER MARIE-HÉLÈNE , D'ELIA DANIELA , ILBIZIAN PIERRE , BEAUGER CHRISTIAN , RIGACCI ARNAUD , HOCHEPIED JEAN-FRANÇOIS , ACHARD PATRICK
Published: February 2009

TiO 2 aerogel–10 mol% TiO 2 nanowire composite was prepared by a sol–gel technique with the addition of TiO 2 nanowires to TiO 2 sol, followed by supercritical drying in CO 2. TiO 2 nanowires (anatase with minor rutile phases) as dispersoid were prepared by a hydrothermal process followed by calcination in air at 600°C. The TiO 2 nanowires were dispersed in a 2-propanol/ H 2 O / HNO 3 solution, and the mixture was added drop by drop to a tetrabutyl orthotitanate [i.e. Ti (IV) n-butoxide] solution in 2-propanol. After gelation, the TiO 2 alcogel– TiO 2 nanowire composite was dried in supercritical CO 2 to obtain the final, TiO 2 aerogel– TiO 2 nanowire composite. TEM analysis revealed that a unique "nanowire network" structure was formed within the mesoporous aerogel matrix. The aerogel– TiO 2 nanowire composite had a relatively large surface area 427 m2/g, with mesopores ~ 16 nm in diameter and a pore of volume of 1.63 cm3/g.
EXTRACTING ENERGY FROM NOISE: NOISE BENEFITS IN HYSTERETIC SYSTEMS
Authors: DIMIAN MIHAI
Published: February 2009

Noise plays a major role in the behavior of various physical and biological systems, its effects being increasingly pronounced with decrease in system size. While it is jeopardizing the future development of several nanotechnologies, such as magnetic data storage, noise can also play a constructive role in many nonlinear systems, activating a resonance response. In this paper, it is proven that various hysteretic systems can exhibit such coherent behavior — a phenomenon that is generally known as coherence resonance when is solely induced by noise, and stochastic resonance when an external oscillatory signal is present. The quantity used to characterize the regularity of the stochastic output is the power spectrum, which displays a maximum at the resonance frequency. The calculation of the spectral densities for the outputs of hysteretic systems is performed in the framework of stochastic processes defined on graphs. The case of hysteretic systems described by rectangular loops is discussed and analytical expressions for the output power spectra are derived. These theoretical results suggest that hysteretic systems can be used by nanotechnology for concentrating the energy of a flat, noisy input into a short bandwidth frequency region.
Fe-DECORATED FULLERENE (C60) NANOWHISKERS FOR ENVIRONMENTAL APPLICATION
Authors: SATHISH M. , MIYAZAWA K.
Published: February 2009

Fe -decorated fullerene nanowhiskers were prepared by using the liquid–liquid interfacial precipitation method. The prepared nanowhiskers were characterized using scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), X-ray diffraction (XRD) and Raman spectroscopy. Formation of both tubular and nontubular nanowhiskers was observed with fine dispersion of Fe ions. The XRD and Raman-spectroscopic studies showed the fcc crystalline nature and polymerization of the nanowhiskers, respectively. The results were compared with Ce - and Ni -incorporated fullerene nanowhiskers.
Downregulation of Grb2 contributes to the insulin-sensitizing effect of calorie restriction
Authors: Liu Xianling , Liu Meilian , Zhang Jingjing , Bai Xiang , Ramos Fresnida , Van Remmen Holly , Richardson Arlan , Liu Fu-You , Dong Lily Q. , Liu Feng
Published: February 2009

Calorie restriction (CR) alleviates insulin resistance and has a beneficial effect on numerous metabolic disorders, yet the underlying mechanism has not been fully elucidated. In the present study, we found that CR of mice (60% of the diet consumption compared with ad libitum mice) reduces the expression levels of Grb2 in skeletal muscle, an insulin target tissue that accounts for 85% of insulin-stimulated blood glucose clearance. To determine whether Grb2 downregulation contributes to increased insulin sensitivity in the regulation of glucose metabolism, we generated C2C12 cell lines in which the expression of Grb2 is suppressed by RNA interference. Suppressing Grb2 expression in C2C12 myoblasts enhances insulin-stimulated insulin receptor substrate (IRS)-1, tyrosine phosphorylation, and Akt phosphorylation, which is associated with decreased IRS-1 serine phosphorylation at residues 307, 612, and 636/639. In addition, reducing Grb2 expression levels increased insulin-stimulated glucose uptake in C2C12 myotubes. Reduced IRS-1 serine phosphorylation is also found in Grb2+/− heterozygous knockout mice, which is associated with enhanced insulin signaling and resistance to high-fat diet-induced glucose and insulin intolerance. All together, our results suggested that reducing the expression levels of Grb2 provides a mechanism by which CR increases insulin sensitivity in vivo.
Determinants of GH-releasing hormone and GH-releasing peptide synergy in men
Authors: Veldhuis Johannes D. , Bowers Cyril Y.
Published: February 2009

Age, sex steroids, and abdominal-visceral fat (AVF) jointly affect pulsatile growth hormone (GH) secretion. Pulsatile GH secretion in turn is controlled by GH-releasing hormone (GHRH), GH-releasing peptide (GHRP), and somatostatin. Marked stimulation of pulsatile GH secretion is achieved via GHRH-GHRP synergy. Nonetheless, how key modulators of GH secretion, such as age, sex steroids, and body mass index, modify GHRH-GHRP synergy is not known. The present strategy was to 1) infuse GHRH and GHRP-2 simultaneously to evoke synergy and 2) downregulate the gonadal axis with leuprolide and then restore placebo (Pl) or testosterone (T) to clamp the sex steroid milieu. Forty-seven men [18–74 yr of age, T = 7–1,950 ng/dl, estradiol (E2) = 5–79 pg/ml, insulin-like growth factor (IGF)-I = 115–817 μg/l, AVF = 11–349 cm2] were studied. GHRH-GHRP synergy correlated negatively with age and AVF (both P < 0.001) and positively with IGF-I ( P < 0.001) and IGF-binding protein (IGFBP)-3 ( P = 0.031). Unstimulated basal (nonpulsatile) GH secretion correlated positively with T ( P = 0.015) and E2 ( P = 0.004) concentrations. Fasting pulsatile GH secretion varied negatively with age ( P = 0.017) and positively with IGF-I ( P = 0.002) and IGFBP-3 ( P = 0.001). By stepwise forward-selection multivariate analyses, AVF, IGF-I, and IGFBP-3 together explained 60% of the variability in GHRH-GHRP synergy ( P < 0.001), E2 accounted for 17% of the variability in basal GH secretion ( P = 0.007), and IGF-I explained 20% of the variability in fasting pulsatile GH secretion ( P = 0.002). In conclusion, a paradigm examining GHRH-GHRP synergy under a sex steroid clamp reveals highly selective control of basal, pulsatile, and synergistic peptide-driven GH secretion by AVF, E2, and IGF-I in healthy men.
Elevated expression of protein biosynthesis genes in liver and muscle of hibernating black bears (Ursus americanus)
Authors: Fedorov Vadim B. , Goropashnaya Anna V. , Tøien Øivind , Stewart Nathan C. , Gracey Andrew Y. , Chang Celia , Qin Shizhen , Pertea Geo , Quackenbush John , Showe Louise C. , Showe Michael K. , Boyer Bert B. , Barnes Brian M.
Published: February 2009

We conducted a large-scale gene expression screen using the 3,200 cDNA probe microarray developed specifically for Ursus americanus to detect expression differences in liver and skeletal muscle that occur during winter hibernation compared with animals sampled during summer. The expression of 12 genes, including RNA binding protein motif 3 ( Rbm3), that are mostly involved in protein biosynthesis, was induced during hibernation in both liver and muscle. The Gene Ontology and Gene Set Enrichment analysis consistently showed a highly significant enrichment of the protein biosynthesis category by overexpressed genes in both liver and skeletal muscle during hibernation. Coordinated induction in transcriptional level of genes involved in protein biosynthesis is a distinctive feature of the transcriptome in hibernating black bears. This finding implies induction of translation and suggests an adaptive mechanism that contributes to a unique ability to reduce muscle atrophy over prolonged periods of immobility during hibernation. Comparing expression profiles in bears to small mammalian hibernators shows a general trend during hibernation of transcriptional changes that include induction of genes involved in lipid metabolism and carbohydrate synthesis as well as depression of genes involved in the urea cycle and detoxification function in liver.
Hepatitis B Associated Monoclonal Gammopathy That Resolved after Successful Liver Transplant
Authors: Sreenivasan P. , Nair S.
Published: February 2009

Monoclonal gammopathy of undetermined significance (MGUS) has been most commonly associated with diseases like multiple myeloma, Waldenstrom's macroglobulinemia, primary systemic amyloidosis, HIV, and other lymphoproliferative disorders. There has been an isolated report of MGUS in patients coinfected with HIV and Hepatitis B, as the work by Amara et al. in 2006. Here, we report a case of IgA-kappa light chain gammopathy secondary to Hepatitis B infection, which resolved after liver transplantation. To our knowledge, this is the first reported case of M protein spike seen in the context of Hepatitis B infection only.
Intramuscular Fetal Corticosteroid Therapy: Short-Term Effects on the Fetus
Authors: Babovic I. , Plesinac S. , Opalic J. , Devrnja V. , Pavlovic I. , Radojicic Z. , Plecas D. , Radunovic N. , Ljubic A.
Published: February 2009

Objective: The aim of the study was to assess the short-term effects of direct intramuscular (i.m.) corticosteroid therapy on fetal biophysical profile, baseline fetal heart rate and the nonstress test, which indicate the degree of fetal hypoxia. Method: We evaluated the effect of direct i.m. fetal single-dose dexamethasone (4 mg/kg) on the fetal biophysical profile 2 h before and 2–4 h after corticosteroid therapy in 41 fetuses in the 32nd week of gestation at risk of preterm delivery. Risk factors for preterm delivery included pregnancy-induced hypertension and preeclampsia. Result: There was a statistically significant difference between fetal breathing movements before and after corticosteroid therapy (p = 0.019; 95% confidence interval for difference –11.75, –1.12). No significant changes were observed between baseline fetal heart rate before and after corticosteroid therapy (p = 0.99; 95% confidence interval for difference –4.81, +4.81), biophysical profile before and after fetal corticosteroid therapy, p = 0.235 as well as the nonstress test before and after therapy (p = 0.564). Conclusion: Direct corticosteroid i.m. fetal therapy results in increasing profound short-term fetal breathing movements. There are no changes in baseline fetal heart rate, biophysical profile score, and nonstress test.
The German Transregional Collaborative Research Centre ‘Inflammatory Cardiomyopathy – Molecular Pathogenesis and Therapy’
Authors: Angelow A. , Weitmann K. , Schmidt M. , Schwedler S. , Vogt H. , Havemann C. , Staudt A. , Felix S.B. , Stangl K. , Klingel K. , Kandolf R. , Kühl U. , Lassner D. , v. Schlippenbach J. , Schultheiss H.-P. , Hoffmann W.
Published: February 2009

Objectives: This report focuses on the design and methods of the 3-centre clinical study of the Transregional Collaborative Research Centre ‘Inflammatory Cardiomyopathy – Molecular Pathogenesis and Therapy’, which aims to establish a comprehensive research registry on the diagnostics, therapy and disease outcomes of patients with inflammatory cardiomyopathy (CMi). The study goals are to investigate specific disease sub-entities and to develop standardised strategies for diagnostics and treatment. Methods: All consecutive patients with clinically suspected CMi, post-myocarditic cardiomyopathy and acute myocarditis are included in the research registry. Cardiopulmonary functional tests, clinical and patient data are obtained at baseline and subsequent readmission appointments and are linked to allow for prospective follow-up. Co-morbidities, quality of life, health- related behaviour and sociodemographic variables are ascertained using uniform self-administered questionnaires. Present Status: By May 2008, 2,061 cases had been included in the research registry (1,300 data-sets completed). At registration, 335 patients were diagnosed with CMi. The mean age was 50 ± 13 years and the mean ejection fraction was 39.9 ± 15.8%. Conclusions: The broad range of the acquired molecular-biological, histological, immunohistological, clinical and patient data makes this the most comprehensive research registry on patients with CMi to date.
Potential Role for Matrix Metallo- proteinase-3 in Gastric Ulcer Healing
Authors: Tomita Makoto , Ando Takafumi , Minami Masaaki , Watanabe Osamu , Ishiguro Kazuhiro , Hasegawa Motofusa , Miyake Nobuyuki , Kondo Shinya , Kato Tsuyoshi , Miyahara Ryoji , Ohmiya Naoki , Niwa Yasumasa , Goto Hidemi
Published: February 2009

Background/Aims: Matrix metalloproteinases (MMPs) are endopeptidases which perform important functions in extracellular matrix remodeling, cell proliferation, and inflammatory processes. Here, we compared MMP-3 levels with those of tissue inhibitor of metalloproteinases (TIMP)-1 and several inflammatory cytokines in gastric ulcer (GU) patients. Methods: This study enrolled 50 patients with GU and 6 with functional dyspepsia (FD). Samples of gastric mucosa from the antrum and the ulcer site were harvested from GU patients and of antral mucosa alone from FD patients during upper gastrointestinal endoscopy. Mucosal biopsy tissues were cultured for 24 h, and the culture supernatant was measured for levels of MMP-3, TIMP-1, IL-1β, IL-6, and IL-8. Results: All GU patients were positive for Helicobacter pylori, while all FD patients were negative. Antral levels of TIMP-1, IL-1β, IL-6, and IL-8 were significantly higher in GU than FD patients. Further, MMP-3 levels were significantly higher in GU patients at the ulcer site than in the antrum, and had a significantly positive correlation with TIMP-1, IL-1β, IL-6, and IL-8. Conclusion: MMP-3 levels were significantly higher at the ulcer site than in the antrum, suggesting that MMP-3 may perform an important function in gastric ulcer healing.
Pegylated Interferon plus Ribavirin Combination Therapy for Chronic Hepatitis C with High Viral Load of Serum Hepatitis C Virus RNA, Genotype 1b, Discontinued on Attaining Sustained Virological Response at Week 16 after Onset of Acute Pancreatitis
Authors: Kim Soo Ryang , Imoto Susumu , Mita Keiji , Taniguchi Miyuki , Sasase Noriko , Muramatsu Akira , Kudo Masatoshi , Kitai Satoshi , El-Shamy Ahmed , Hotta Hak , Hayashi Yoshitake
Published: February 2009

Recent clinical trials have shown that pegylated interferon-α (PEG-IFN-α) in combination with ribavirin (RBV) improves the rate of sustained virological response (SVR), with over 50% of patients demonstrating a positive response to treatment. However, no SVR has been reported when PEG-IFN/RBV combination therapy is discontinued by week 16, especially in cases of chronic hepatitis with a high viral load of serum hepatitis C virus (HCV) RNA, genotype 1b. Here, we describe SVR in a 67-year-old woman whose PEG-IFN/RBV combination therapy for chronic hepatitis C with a high viral load of serum HCV RNA, genotype 1b, was discontinued after 16 weeks because of the onset of PEG-IFN plus RBV-induced acute pancreatitis. Among viral factors, substitution of amino acid 70 (Arg) and 91 (Leu) in the core region and HCV RNA negativity were observed after 8 weeks. Host factors including low body weight, no alcohol consumption, no coinfection with hepatitis B virus, slight fibrosis, and viral factors including early viral clearance, double wild type in the core region, may have contributed to the SVR irrespective of the discontinuation of the combination therapy at week 16. Moreover, PEG-IFN plus RBV-induced acute pancreatitis might have been related to the SVR.
Pivotal Role of Bedside Doppler Echocardiography in the Assessment of Patients with Acute Heart Failure and Mitral Regurgitation
Authors: Ennezat Pierre Vladimir , Bellouin Annaïk , Maréchaux Sylvestre , Juthier Francis , Fayad Georges , Vincentelli André , Berrébi Alain , Auffray Jean Luc , Bauchart Jean Jacques , Mouquet Frédéric , Montaigne David , Asseman Philippe , Le Jemtel Thierry H. , Pibarot Philippe
Published: February 2009

Patients presenting with mitral regurgitation and acute heart failure remain a challenge for the clinicians. Bedside echocardiography ascertains the functional or primary nature of mitral regurgitation, thereby allowing to focus therapy on the left ventricle and mitral valve apparatus in patients with functional mitral regurgitation and to hasten mitral valve repair or replacement when acute heart failure results from primary mitral regurgitation. This short article reviews the evaluation by bedside echocardiography to guide management of these patients.
Assessment of Patient and Caregiver Experiences of Dementia-Related Symptoms: Development of the Multidimensional Assessment of Neurodegenerative Symptoms Questionnaire
Authors: Locke Dona E.C. , Dassel Kara B. , Hall Geri , Baxter Leslie C. , Woodruff Bryan K. , Hoffman Snyder Charlene , Miller Bruce L. , Caselli Richard J.
Published: February 2009

Background: To provide preliminary validation data on a self- or informant-report multidimensional questionnaire of symptoms associated with neurodegenerative disorders. Methods: Participants from 2 trials (n = 125), the Arizona APOE Cohort and the Arizona Alzheimer’s Disease Center, completed the Multidimensional Assessment of Neurodegenerative Symptoms questionnaire (MANS) and other related measures. Results: Measures of central tendency are provided for the sample as a whole and by cognitive status. Internal consistency of the MANS is excellent (α = 0.98). Factor analysis suggests 4 factors. Correlational analyses support the construct validity of the MANS with moderate to high (r = 0.54–0.87) correlations between the MANS and measures of mood, cognition and daily functioning. Conclusion: Results provide initial support for the MANS as a brief measure that is a reliable and valid indicator of cognitive, personality, functional and motor symptoms potentially related to neurodegenerative etiologies. Further research with the MANS is warranted.
Systemic Therapy of Metastatic Breast Cancer: The Truth Beyond the Clinical Trials
Authors: Gueth Uwe , Huang Dorothy Jane , Schoetzau Andreas , Holzgreve Wolfgang , Wight Edward
Published: February 2009

Objective: To depict a clear and coherent picture of the overall course of palliative treatment in an unselected study cohort over the course of time. Methods: We compared therapy type and course of 242 women whose distant metastatic disease was diagnosed from 1990 to 2006 and who ultimately died of the disease. We divided the patients into two subgroups depending on the year of diagnosis of metastases (group A: 1998–2006 vs. group B: 1990–1997). Results: In both subgroups, there were no significant differences in the general type of treatment and the number of administered therapy lines (no systemic therapy: 12.9 vs.13.7%, p = 0.848; endocrine therapy only: 20.4 vs. 25.2%, p = 0.430; chemotherapy only: 18.4 vs.16.9%, p = 0.735; sequential combination regimen including endocrine therapy/chemotherapy/trastuzumab: 46.9 vs. 44.2%, p = 0.694; median: 2 lines). In the cases where chemotherapy was administered, there were no differences between the number of lines among older and younger patients (median: two lines; ≥70 years vs. <70 years: p = 0.269). The median metastatic disease-specific survival increased from 16 months in the period from 1990 to 1997, to 21 months in the period from 1998 to 2000 (p = 0.062). Conclusion: The number of patients who died from metastatic breast cancer without receiving any antineoplastic therapy was surprisingly high. The use of newer agents and regimens in the treatment of metastatic breast cancer was associated with an improved survival over time. Chemotherapy is a feasible option also among older patients.
Mechanisms of Enhanced β-Adrenergic Reserve From Cardiac Resynchronization Therapy
Authors: Chakir Khalid , Daya Samantapudi K. , Aiba Takeshi , Tunin Richard S. , Dimaano Veronica L. , Abraham Theodore P. , Jaques Kathryn , Lai Edwin W. , Pacak Karel , Zhu Wei-Zhong , Xiao Rui-ping , Tomaselli Gordon F. , Kass David A.
Published: February 2009

Background—

Cardiac resynchronization therapy (CRT) is the first clinical heart failure treatment that improves chamber systolic function in both the short-term and long-term yet also reduces mortality. The mechanical impact of CRT is immediate and well documented, yet its long-term influences on myocyte function and adrenergic modulation that may contribute to its sustained benefits are largely unknown.

Methods and Results—

We used a canine model of dyssynchronous heart failure (DHF; left bundle ablation, atrial tachypacing for 6 weeks) and CRT (DHF for 3 weeks, biventricular tachypacing for subsequent 3 weeks), contrasting both to nonfailing controls. CRT restored contractile synchrony and improved systolic function compared with DHF. Myocyte sarcomere shortening and calcium transients were markedly depressed at rest and after isoproterenol stimulation in DHF (both anterior and lateral walls), and CRT substantially improved both. In addition, β
1
and β
2
stimulation was enhanced, coupled to increased β
1
receptor abundance but no change in binding affinity. CRT also augmented adenylate cyclase activity over DHF. Inhibitory G-protein (Gα
i
) suppression of β-adrenergic stimulation was greater in DHF and reversed by CRT. Gα
i
expression itself was unaltered; however, expression of negative regulators of Gα
i
signaling (particularly RGS3) rose uniquely with CRT over DHF and controls. CRT blunted elevated myocardial catecholamines in DHF, restoring levels toward control.

Conclusions—

CRT improves rest and β-adrenergic–stimulated myocyte function and calcium handling, upregulating β
1
receptors and adenylate cyclase activity and suppressing G
i
-coupled signaling associated with novel RGS upregulation. The result is greater rest and sympathetic reserve despite reduced myocardial neurostimulation as components underlying its net benefit.