bluuebunny/crossref_metadata_2025 huggingface dataset:
NONLINEAR STABILITY OF THE INITIAL-BOUNDARY VALUE PROBLEM FOR THE BROADWELL MODEL AROUND A MAXWELLIAN
Authors: LIN HUEY-ER
Published: May 2011

We study the nonlinear stability of the equilibrium state associated with the initial boundary value problem for the Broadwell model with transonic boundary. Based on the Green's function of this linearized initial boundary value problem and on the understanding of its action on microscopic data, we establish the pointwise convergence of the solution toward the equilibrium state under small perturbation, via a solution representation and Picard-like iterations.
GENERALIZED CHARACTERISTICS AND THE HUNTER–SAXTON EQUATION
Authors: DAFERMOS CONSTANTINE M.
Published: May 2011

The method of generalized characteristics yields an elementary proof of uniqueness of dissipative solutions to the Cauchy problem for the Hunter–Saxton equation.
REGULARITY OF WEAKLY WELL POSED HYPERBOLIC MIXED PROBLEMS WITH CHARACTERISTIC BOUNDARY
Authors: MORANDO ALESSANDRO , SECCHI PAOLO
Published: May 2011

We study the mixed initial-boundary value problem for a linear hyperbolic system with characteristic boundary of constant multiplicity. We assume the problem to be "weakly" well posed, in the sense that a unique L2-solution exists, for sufficiently smooth data, and obeys an a priori energy estimate with a finite loss of conormal regularity. This is the case of problems that do not satisfy the uniform Kreiss–Lopatinskiĭ condition in the hyperbolic region of the frequency domain. Under the assumption of the loss of one conormal derivative we obtain the regularity of solutions, in the natural framework of weighted anisotropic Sobolev spaces, provided the data are sufficiently smooth.
STRUCTURAL AND OPTICAL PROPERTIES OF Eu3+ DOPED CERIUM OXIDE NANOPHOSPHORS
Authors: SRINIVASAN R. , CHANDRA BOSE A.
Published: May 2011

Europium (3%) doped ceria nanoparticles were successfully prepared by 72 h hydrolysis assisted co-precipitation method. The average grain size of the as-prepared sample was 11 nm. The grain sizes were 12 and 18 nm for samples annealed at 500°C and 800°C respectively. The grain size effect on optical bandgap is investigated from diffuse reflectance spectroscopy (DRS). The orange and red color emissions of europium doped ceria nanoparticles were investigated by photoluminescence (PL) spectra under excitation of 330 nm. The high intense orange emission peak was found at 591 nm for as-prepared and annealed nanoparticles. This is the characteristic peak of the Eu 3+ ion corresponding to the parity allowed magnetic dipole transition between the 5 D 0–7 F 1 states. Site occupancy of europium ions was estimated by Red (R)/Orange (O) intensity ratio using PL spectrum.
THIOCYANATE-FREE, PANCHROMATIC RUTHENIUM (II) TERPYRIDINE SENSITIZER HAVING A TRIDENTATE DIETHYLENETRIAMINE LIGAND FOR NEAR-IR SENSITIZATION OF NANOCRYSTALINE TiO2
Authors: ISLAM ASHRAFUL , SINGH SURYA PRAKASH , HAN LIYUAN
Published: May 2011

A thiocyanate-free Ru (II) terpyridine complex containing a tridentate chelating ligand diethylenetriamine, Ru (4,4′, 4″-tricarboxy-2,2′:6′, 2″-terpyridine)(diethylenetriamine) 1 achieves very efficient panchromatic sensitization of nanocrystalline TiO 2 solar cell over the whole visible range extending into the near IR region (ca. 900 nm) with a maximum value of 76% at around 600 nm. A solar energy to electric power conversion efficiency (η) of 7.9% was attained under standard AM 1.5 irradiation (100 mW cm-2) with a short-circuit photocurrent density (J sc ) of 17.5 mA cm-2, an open-circuit photovoltage (V oc ) of 0.67 V, and a fill factor (ff) of 0.68.
TRAP DISTRIBUTION NEAR THE ENERGY BAND GAP EDGE IN MDMO-PPV
Authors: KAŽUKAUSKAS VAIDOTAS , PRANAITIS MINDAUGAS
Published: May 2011

Carrier transport and trapping was investigated in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) layers by thermally stimulated currents (TSC) depending on the exciting light spectral range. The upper edge of the light spectra was varied from 1.77 eV up to 3.1 eV to assure selective excitation of the defect states. We had shown that material conductivity is affected by several thermally activated processes, i.e., carrier generation from trapping states and thermally stimulated mobility growth. If the below band gap excitation was used, the effective photoconductivity activation energy values of 0.13–0.15 eV were obtained. After the above band gap excitation, the effective photoconductivity activation energy values decreased to 0.05 eV. The energy distribution of the trapping state density was shown to follow the Gaussian distribution function. The deeper states with activation energies of 0.28–0.3 eV and 0.8–0.85 eV were identified too. The results are direct indication by photo-thermo-electrical methods of distributed in energy trapping and transport states with the standard deviation of the density of states of about 0.015 eV.
STRUCTURAL, SINTERING AND OXYGEN SORPTION PROPERTIES OF A NOVELFe/NbCO-DOPED PEROVSKITEBa(Co0.8Fe0.1Nb0.1)O3-δOXIDE
Authors: LU HUI , ZHANG YAN , YIN CHUNLING , ZHANG YUJUN
Published: May 2011

The novel Fe/Nb co-doped Ba(Co0.8Fe0.1Nb0.1)O3-δoxide was synthesized by the solid-state reaction method. Structural, sintering and oxygen sorption properties of the Ba(Co0.8Fe0.1Nb0.1)O3-δoxide were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetry (TG). The results demonstrate that the structural stability of the Fe/Nb co-doped Ba(Co0.8Fe0.1Nb0.1)O3-δoxide is improved significantly. The oxygen sorption property of the Fe/Nb co-doped Ba(Co0.8Fe0.1Nb0.1)O3-δoxide was investigated in air between 300°C and 900°C, and an oxygen sorption capacity of 7.0 mL(STP) O2/g oxide is obtained.
THE EFFECT OF CARBON FILLER TYPE ON ACTUATION BEHAVIOR OF CONDUCTING POLYMER ACTUATOR
Authors: JO NAM-JU , LIM HYUN-OK , PARK MIN-YOUNG , PARK HYUN , LEE IN-WON , CHUN HO-HWAN
Published: May 2011

Conducting polymer (CP) actuators undergo a volume change as the redox state is changed. The volume change is caused by the movement of counter ions into the film during the electrical oxidation process. In freestanding CP actuators, the electrical resistance of a CP film can produce significant power-supply voltage (IR) drop along its length, which can restrict the actuator performance. To solve this problem, CP nanocomposite with carbon filler was introduced. This study aimed to improve conductivity and ease off the IR drop occurred during the actuation of CP actuator. CP nanocomposite actuator with 3:7 of CB:CNF co-filler content showed the maximum displacement due to the synergy effect, and did not involve IR drop when the length of actuator was 25 mm.
HIERARCHICAL CARBON NANOTUBE-INORGANIC HYBRID STRUCTURES INVOLVING CNT ARRAYS AND CNT FIBERS
Authors: NEOCLEUS S. , PATTINSON S. W. , MOISALA MOTTA A. M. , WINDLE A. H. , EDER D.
Published: May 2011

Carbon nanotube-inorganic hybrid materials have stimulated a new boost in CNT research as a new class of multifunctional materials with properties distinct from the well-known CNT composites. Synergistic effects based on interfacial charge and heat transfer processes commend these hybrids for use in photocatalysis, gas sensors and in electrochemical devices. A major challenge is the synthesis of hybrids with hierarchical architectures and controlled interfaces. Common wet-chemical techniques have the major drawback that the CNT array typically collapses upon drying due to stresses imposed by the surface tension of the solvent. In this work, we synthesized hierarchical hybrids with coherent 3D architectures using unique CNT fibers, based on the "Cambridge process" as well as vertical arrays of CNTs ("carpets"). We demonstrate that separating the liquid reactants from the CNT array is key to preserving the hybrid's architecture. In addition, we show that the presence of benzyl alcohol as a linking agent is beneficial to maximizing the interfacial area in TiO 2-coated CNT fibers.
DIELECTRIC PROPERTIES OF EPITAXIAL Ba1-xSrxTiO3 FILMS ON MgO SUBSTRATES
Authors: PARK BAE HO , LI Y. R. , XIONG J. , JIA Q. X.
Published: May 2011

We have systematically studied the dielectric properties of epitaxial barium strontium titanate, Ba1-xSrxTiO3 (x = 0.0, 0.1, 0.2, …, 1.0), films on MgO substrates grown by pulsed laser deposition. The dielectric properties of Ba1-xSrxTiO3 films at a frequency of 1 MHz and room temperature are a strong function of Ba/Sr ratio. The degree of electric field dependent dielectric constant is more pronounced with decrease of x values. The largest dielectric tunability and the figure of merit (or tunability/loss) are obtained at x = 0.3 and at x = 0.4, respectively.
ENHANCED ELECTROCALORIC PROPERTIES OF PMN-PT THIN FILMS WITH LSCO BUFFER LAYERS
Authors: HE Y. , LI X. M. , GAO X. D. , LENG X. , WANG W.
Published: May 2011

Lead magnesium niobate-lead titanate (PMN-PT) ferroelectric thin films were deposited on Ir/SrTiO3/TiN/Si (001) substrates by oxygen plasma assisted pulsed laser deposition (PLD) method. Effects of the lanthanum strontium cobaltite (LSCO) buffer layer between the PMN-PT film and the Ir layer on the crystallinity, microstructure, ferroelectric properties and electrocaloric effect of the film were investigated. Results show that the LSCO buffer layer can improve the crystallinity and electrocaloric properties effectively. By applying a voltage of 5V to the PMN-PT thin film without the LSCO buffer layer, the changes in the reversible adiabatic temperature measured at room temperature and at 508 K are respectively 0.73 K and 2.13 K, while by introducing a LSCO buffer layer, the corresponding values are increased to 1.41 K and 4.25 K.
EFFECTS OF ARGON+ ION BOMBARDMENT ON A PLATINUM/ZIRCONIUM DIOXIDE/IRIDIUM RESISTIVE SWITCHING MEMORY CELL
Authors: OH GWANGTAEK , HWANG INROK , KIM JIN-SOO , CHOI JINSIK , SON JONG WAN , HONG SAHWAN , PARK BAE HO
Published: May 2011

We have fabricated Pt/ZrO2/Ir memory cells with pristine and Ar+ ion bombarded ZrO2 films, which show unipolar resistive switching behaviors. Ar+ ion bombardment induces change in surface morphology and chemical states of ZrO2 films. We have found that forming voltage significantly decreases in a Pt/ZrO2/Ir memory cell whose Ar+ ion bombarded ZrO2 film shows oxygen vacancy like defects and the largest root-mean-square (RMS) roughness. It seems that forming process may be more easily induced in an Ar+ ion bombarded ZrO2 film with higher RMS roughness mainly due to locally enhanced electric field in a region with oxygen vacancy like defects.
SPINEL Li2MTi3O8(M = Mg, Mg0.5Zn0.5) NANOWIRES WITH ENHANCED ELECTROCHEMICAL LITHIUM STORAGE
Authors: HONG ZHENSHENG , LAN TONGBIN , ZHENG YONGZAN , JIANG LILONG , WEI MINGDENG
Published: May 2011

Spinel structural Li2MTi3O8 ( M = Mg, Mg0.5Zn0.5 ) nanowires have been successfully synthesized using titanate nanowires as a precursor and then have been used for the first time as anode materials in a rechargeable Li -ion battery. The cell composed of Li2MgTi3O8 nanowires exhibited a discharge capacity of 232 mAhg-1 at the second cycle, while only 159 mAhg-1 was obtained for the bulk prepared by a solid state reaction. The results of electrochemical impedance spectra indicate that spinel structural Li2MTi3O8 ( M = Mg, Mg0.5Zn0.5 ) nanowires can significantly reduce the charge transfer impedance, leading to enhanced capability of electrochemical lithium storage.
Conodont Colour Alteration pattern in the Carboniferous of the Craven Basin and adjacent areas, northern England
Authors: Metcalfe I. , Riley N. J.
Published: May 2011

Conodont Colour Alteration Indices (CAI) values in the Craven area show a general range of 2.5–3.5, the majority being a value of 3. The higher values generally occur in the south and south-west and low values are found on the Ashnott High (Ashnott Anticline and eastern closure of the Whitewell Anticline) and in Waulsortian limestones. These values are consistent with the limited vitrinite reflectance data and are a result of the Carboniferous sedimentary and tectonic history of the region. There is no evidence of significant modification by subsequent burial, igneous events, reheating or mineralization. Low values of CAI 2–2.5 on the Ashnott High are interpreted to be due to the thinner sedimentary cover in that area and possible insulation derived from underlying Waulsortian limestones. Relatively high values of CAI 4 for Dinantian strata in the Holme Chapel Borehole and 3.5 in the Silesian sediments to the south of the Craven Basin probably reflect a thicker Westphalian cover than further north.
The North Pennine batholith (Weardale Granite) of northern England: new data on its age and form
Authors: Kimbell G. S. , Young B. , Millward D. , Crowley Q. G.
Published: May 2011

A three-dimensional gravity model of the North Pennine batholith is interpreted to show that it comprises five contiguous steep-sided plutons. The North Pennine batholith was previously referred to as the Weardale Granite, but this term is now restricted to the largest, most central pluton, which was proved by the Rookhope Borehole in 1961. The surrounding plutons are the Tynehead and Scordale plutons in the west, and the Rowlands Gill and Cornsay plutons in the east. A new U–Pb zircon age of 399.3±0.7 Ma demonstrates an unequivocal Early Devonian (Emsian) age of emplacement for the Weardale Pluton. The similarity of the forms of the four unsampled plutons to the body beneath Rookhope, and to other Devonian granites in northern England, strongly suggests that they are also of Devonian age. Seismic reflection evidence supports a contrast between relatively deep-seated Devonian granites and tabular Ordovician granites in northern England. The most conspicuous magnetic anomalies over the North Pennine batholith are associated with the Early Permian Great Whin Sill, but there is also evidence of magnetized basement rocks or denser magnetic intrusive phases on the flanks of the non-magnetic, low density plutons. A long-wavelength magnetic low can be explained in part by the granite puncturing a deep magnetic basement, although the demagnetized zone may extend beneath the batholith. A spatial correlation between the vein systems in the Northern Pennine Orefield and the form of the batholith suggests that the granite masses played a significant role in focussing mineralizing fluids into the overlying Carboniferous rocks. The highest temperature mineralization occurs over the Weardale and Tynehead plutons, where there is also the clearest evidence for the channelling of mineralizing fluids through the batholith. The other plutons are generally associated with a lower intensity of mineralization, which occurs on their flanks rather than above their roofs. The Rookhope and Tynehead areas may therefore mark the location of convective ‘chimneys’ which were important in focussing the fluid circulation responsible for the mineralization. The coincidence of the ‘chimney’ zones with the minimum of the long wavelength magnetic low suggests that the hydrothermal system may also have played a role in modifying crustal magnetization.
Fatally bitten ammonites from the lower Lias Group (Lower Jurassic) of Lyme Regis, Dorset
Authors: Andrew Chris , Howe Paddy , Paul Christopher R. C. , Donovan Stephen K.
Published: May 2011

Little is known about ammonites as prey. Two papers report single British examples of fatally bitten ammonites. Globally, two previous papers describe damage similar to that recorded herein. Nevertheless, in the Charmouth Mudstone Formation of the lower Lias Group at Lyme Regis, up to 20% of small ammonites (
Promicroceras
,
Xipheroceras
,
Cymbites
,
Arnioceras
,
Asteroceras
,
Caenisites
,
Eoderoceras
and
Paltechioceras
?) show ventral damage at the rear of the body chamber that is far too consistent in morphology and position to result from accidents. Single pieces of shell, which extend almost symmetrically on either side and reach the umbilical seam on one side, are missing. Midpoint of the damage lies at 80% of the body chamber length back from the aperture, with a coefficient of variation of 10%. Damage at this position would sever attachment muscles and facilitate removal of the body from the aperture. Lack of shell chips preserved adjacent to damaged ammonites precludes scavenging or post-burial crushing as causes of the damage. Ammonites were caught in the water column, manipulated into a horizontal position and bitten at a precise point. The most likely predator was an active swimmer, able to hold and manipulate a smooth, possibly slippery, ammonite shell. The slightly asymmetrical damage is consistent with bites made by robust, parrot-like, cephalopod jaws (rhyncholites), which are known from the same stratigraphic interval. Ammonites are less likely predators than teuthoids. Belemnites, lacking suckers, are discounted. Lobster-like crustaceans are unlikely to have been able to catch, hold and manipulate shells. Lack of tooth marks precludes most vertebrate predators. These bite marks are referred to
Bicrescomanducator rolli
Donovan, Paul, Andrew & Howe igen. et isp. nov.
Kingsdale: the evolution of a Yorkshire dale
Authors: Waltham T. , Murphy P. , Batty A.
Published: May 2011

The glaciated trough of Kingsdale is a classic feature of the Yorkshire Dales, and is drained by a complex of cave systems. Within some cave passages, sediments and stalagmites have been dated to establish an absolute chronology for at least part of the dale's evolution. Much of the excavation of Kingsdale dates back to fluvial erosion early in the Pleistocene; the dale was then modified by pre-Devensian glaciers and excavated to almost its present depth. Devensian ice increased the depth profile by only a few metres, before leaving moraines that impounded a short-lived lake at the lower end of the dale. A post-Devensian channel now cuts through the main recessional moraine at Raven Ray, beneath which lies a deep buried valley.
Arginine synthesis from enteral glutamine in healthy adults in the fed state
Authors: Tomlinson Chris , Rafii Mahroukh , Ball Ronald O. , Pencharz Paul
Published: May 2011

Recent studies have documented transfer of labeled nitrogen from [2-15N]glutamine to citrulline and arginine in fasting human adults. Conversely, in neonates and piglets we have shown no synthesis of arginine from [2-15N]glutamate, and others have shown in mice that glutamine is a nitrogen, but not a carbon donor, for arginine synthesis. Therefore, we performed a multitracer study to determine whether glutamine is a nitrogen and/or carbon donor for arginine in healthy adult men. Two glutamine tracers, 2-15N and 1-13C, were given enterally to five healthy men fed a standardized milkshake diet. There was no difference in plasma enrichments between the two glutamine tracers. 1-13C isotopomers of citrulline and arginine were synthesized from [1-13C]glutamine. Three isotopomers each of citrulline and arginine were synthesized from the [2-15N]glutamine tracer: 2-15N, 5-15N, and 2,5-15N2. Significantly greater enrichment was found of both [5-15N]arginine (0.75%) and citrulline (3.98%) compared with [2-15N]arginine (0.44%) and [2-15N]citrulline (2.62%), indicating the amino NH2 from glutamine is mostly transferred to arginine and citrulline by transamination. Similarly, the enrichment of the 1-13C isotopomers was significantly less than the 2-15N isotopomers, suggesting rapid formation of α-ketoglutarate and recycling of the nitrogen label. Our results show that the carbon for 50% of newly synthesized arginine comes from dietary glutamine but that glutamine acts primarily as a nitrogen donor for arginine synthesis. Hence, studies using [2-15N]glutamine will overestimate arginine synthesis rates.
The role of the gut sweet taste receptor in regulating GLP-1, PYY, and CCK release in humans
Authors: Gerspach A. C. , Steinert R. E. , Schönenberger L. , Graber-Maier A. , Beglinger C.
Published: May 2011

The recent identification of sweet taste receptors in the gastrointestinal tract has important implications in the control of food intake and glucose homeostasis. Lactisole can inhibit the sweet taste receptor T1R2/T1R3. The objective was to use lactisole as a probe to investigate the physiological role of T1R2/T1R3 by assessing the effect of T1R2/T1R3 blockade on GLP-1, PYY, and CCK release in response to 1) intragastric administration of nutrients or 2) intraduodenal perfusion of nutrients. The study was performed as a randomized, double-blind, placebo-controlled crossover study that included 35 healthy subjects. In part I, subjects received intragastrically 75 g of glucose in 300 ml of water or 500 ml of a mixed liquid meal with or without lactisole. In part II, subjects received an intraduodenal perfusion of glucose (29.3 g glucose/100 ml; rate: 2.5 ml/min for 180 min) or a mixed liquid meal (same rate) with or without lactisole. The results were that 1) lactisole induced a significant reduction in GLP-1 and PYY but not CCK secretion in both the intragastric and the intraduodenal glucose-stimulated parts ( P ≤ 0.05), 2) comparison of the inhibitory effect of lactisole showed a significantly greater suppression of the hormone response in the intragastric part ( P = 0.023), and 3) lactisole had no effect on liquid meal-stimulated parameters. We conclude that T1R2/T1R3 is involved in glucose-dependent secretion of satiation peptides. However, the results of the liquid meal-stimulated parts show that the receptor alone is not responsible for peptide secretion.
Extra-adrenal glucocorticoids and mineralocorticoids: evidence for local synthesis, regulation, and function
Authors: Taves Matthew D. , Gomez-Sanchez Celso E. , Soma Kiran K.
Published: May 2011

Glucocorticoids and mineralocorticoids are steroid hormones classically thought to be secreted exclusively by the adrenal glands. However, recent evidence has shown that corticosteroids can also be locally synthesized in various other tissues, including primary lymphoid organs, intestine, skin, brain, and possibly heart. Evidence for local synthesis includes detection of steroidogenic enzymes and high local corticosteroid levels, even after adrenalectomy. Local synthesis creates high corticosteroid concentrations in extra-adrenal organs, sometimes much higher than circulating concentrations. Interestingly, local corticosteroid synthesis can be regulated via locally expressed mediators of the hypothalamic-pituitary-adrenal (HPA) axis or renin-angiotensin system (RAS). In some tissues (e.g., skin), these local control pathways might form miniature analogs of the pathways that regulate adrenal corticosteroid production. Locally synthesized glucocorticoids regulate activation of immune cells, while locally synthesized mineralocorticoids regulate blood volume and pressure. The physiological importance of extra-adrenal glucocorticoids and mineralocorticoids has been shown, because inhibition of local synthesis has major effects even in adrenal-intact subjects. In sum, while adrenal secretion of glucocorticoids and mineralocorticoids into the blood coordinates multiple organ systems, local synthesis of corticosteroids results in high spatial specificity of steroid action. Taken together, studies of these five major organ systems challenge the conventional understanding of corticosteroid biosynthesis and function.
Acute injection of ASP in the third ventricle inhibits food intake and locomotor activity in rats
Authors: Roy Christian , Roy Marie-Claude , Gauvreau Danny , Poulin Anne-Marie , Tom Fun-Qun , Timofeeva Elena , Richard Denis , Cianflone Katherine
Published: May 2011

Acylation-stimulating protein (ASP; also known as C3adesArg) stimulates triglyceride synthesis and glucose transport via interaction with its receptor C5L2, which is expressed peripherally (adipose tissue, muscle) and centrally. Previous studies have shown that ASP-deficient mice (C3KO) and C5L2-deficient mice (C5L2KO) are hyperphagic (59 to 229% increase, P < 0.0001), which is counterbalanced by increased energy expenditure measured as oxygen consumption (V̇o2) and a lower RQ. The aim of the present study was to evaluate ASP's effect on food intake, energy expenditure, and neuropeptide expression. Male rats were surgically implanted with intracerebroventricular (icv) cannulas directed toward the third ventricle. After a 5-h fast, rats were injected, and food intake was assessed at 0.5, 1, 2, 4, 16, 24, and 48 h, with a 5- to 7-day washout period between each injection. Acute icv injections of ASP (0.3–1,065 pmol) had a time-dependent effect on decreasing food intake by 20 to 57% ( P < 0.05). Decreases were detected by 30 min (maximum 57%, P < 0.01) and at the highest dose effects extended to 48 h (19%, P < 0.05, 24- to 48-h period). Daily body weight gain was decreased by 131% over the first 24 h and 29% over the second 24 h ( P < 0.05). A conditioned taste aversion test indicated that there was no malaise. Furthermore, acute ASP injection affected energy substrate usage, demonstrated by decreased V̇o2and RQ ( P < 0.05; implicating greater fatty acid usage), with a 49% decrease in total activity over 24 h ( P < 0.05). ASP administration also increased anorexic neuropeptide POMC expression (44%) in the arcuate nucleus, with no change in NPY. Altogether ASP may have central in addition to peripheral effects.
Urocortin 1 reduces food intake and ghrelin secretion via CRF2 receptors
Authors: Yakabi Koji , Noguchi Masamichi , Ohno Shino , Ro Shoki , Onouchi Tsuneko , Ochiai Mitsuko , Takabayashi Hidehiko , Takayama Kiyoshige , Harada Yumi , Sadakane Chiharu , Hattori Tomohisa
Published: May 2011

Although it is known that urocortin 1 (UCN) acts on both corticotropin-releasing factor receptors (CRF1 and CRF2), the mechanisms underlying UCN-induced anorexia remain unclear. In contrast, ghrelin, the endogenous ligand for the growth hormone secretagogue receptor, stimulates food intake. In the present study, we examined the effects of CRF1 and CRF2 receptor antagonists (CRF1a and CRF2a) on ghrelin secretion and synthesis, c-fos mRNA expression in the caudal brain stem, and food intake following intracerebroventricular administration of UCN. Eight-week-old, male Sprague-Dawley rats were used after 24-h food deprivation. Acylated and des-acylated ghrelin levels were measured by enzyme-linked immunosorbent assay. The mRNA expressions of preproghrelin and c-fos were measured by real-time RT-PCR. The present study provided the following important insights into the mechanisms underlying the anorectic effects of UCN: 1) UCN increased acylated and des-acylated ghrelin levels in the gastric body and decreased their levels in the plasma; 2) UCN decreased preproghrelin mRNA levels in the gastric body; 3) UCN-induced reduction of plasma ghrelin and food intake were restored by CRF2a but not CRF1a; 4) UCN-induced increase of c-fos mRNA levels in the caudal brain stem containing the nucleus of the solitary tract (NTS) was inhibited by CRF2a; and 5) UCN-induced reduction of food intake was restored by exogenous ghrelin and rikkunshito, an endogenous ghrelin secretion regulator. Thus, UCN increases neuronal activation in the caudal brain stem containing NTS via CRF2 receptors, which may be related to UCN-induced inhibition of both ghrelin secretion and food intake.
Gut sensing of dietary K+ intake increases renal K+ excretion
Authors: Oh Ki-Sook , Oh Young Taek , Kim Sang-Wook , Kita Toshihiro , Kang Insug , Youn Jang H.
Published: May 2011

Dietary K+ intake may increase renal K+ excretion via increasing plasma [K+] and/or activating a mechanism independent of plasma [K+]. We evaluated these mechanisms during normal dietary K+ intake. After an overnight fast, [K+] and renal K+ excretion were measured in rats fed either 0% K+ or the normal 1% K+ diet. In a third group, rats were fed with the 0% K+ diet, and KCl was infused to match plasma [K+] profile to that of the 1% K+ diet group. The 1% K+ feeding significantly increased renal K+ excretion, associated with slight increases in plasma [K+], whereas the 0% K+ diet decreased K+ excretion, associated with decreases in plasma [K+]. In the KCl-infused 0% K+ diet group, renal K+ excretion was significantly less than that of the 1% K+ group, despite matched plasma [K+] profiles. We also examined whether dietary K+ alters plasma profiles of gut peptides, such as guanylin, uroguanylin, glucagon-like peptide 1, and glucose-dependent insulinotropic polypeptide, pituitary peptides, such as AVP, α-MSH, and γ-MSH, or aldosterone. Our data do not support a role for these hormones in the stimulation of renal K+ excretion during normal K+ intake. In conclusion, postprandial increases in renal K+ excretion cannot be fully accounted for by changes in plasma [K+] and that gut sensing of dietary K+ is an important component of the regulation of renal K+ excretion. Our studies on gut and pituitary peptide hormones suggest that there may be previously unknown humoral factors that stimulate renal K+ excretion during dietary K+ intake.
Differences in the substrate binding regions of renal organic anion transporters 1 (OAT1) and 3 (OAT3)
Authors: Astorga Bethzaida , Wunz Theresa M. , Morales Mark , Wright Stephen H. , Pelis Ryan M.
Published: May 2011

This study examined the selectivity of organic anion transporters OAT1 and OAT3 for structural congeners of the heavy metal chelator 2,3-dimercapto-1-propanesulfonic acid (DMPS). Thiol-reactive reagents were also used to test structural predictions based on a homology model of OAT1 structure. DMPS was near equipotent in its ability to inhibit OAT1 (IC50 = 83 μM) and OAT3 (IC50 = 40 μM) expressed in Chinese hamster ovary cells. However, removal of a thiol group (3-mercapto-1-propanesulfonic acid) resulted in a 2.5-fold increase in IC50 toward OAT1 vs. a ∼55-fold increase in IC50 toward OAT3. The data suggested that compound volume/size is important for binding to OAT1/OAT3. The sensitivity to HgCl2 of OAT1 and OAT3 was also dramatically different, with IC50 values of 104 and 659 μM, respectively. Consistent with cysteines of OAT1 being more accessible from the external medium than those of OAT3, thiol-reactive reagents reacted preferentially with OAT1 in cell surface biotinylation assays. OAT1 was less sensitive to HgCl2 inhibition and less reactive toward membrane-impermeant thiol reactive reagents following mutation of cysteine 440 (C440) to an alanine. These data indicate that C440 in transmembrane helix 10 of OAT1 is accessible from the extracellular space. Indeed, C440 was exposed to the aqueous phase of the presumptive substrate translocation pathway in a homology model of OAT1 structure. The limited thiol reactivity in OAT3 suggests that the homologous cysteine residue (C428) is less accessible. Consistent with their homolog-specific selectivities, these data highlight structural differences in the substrate binding regions of OAT1 and OAT3.
The speed of context integration in the visual cortex
Authors: Sugihara Tadashi , Qiu Fangtu T. , von der Heydt Rüdiger
Published: May 2011

The observation of figure-ground selectivity in neurons of the visual cortex shows that these neurons can be influenced by the image context far beyond the classical receptive field. To clarify the nature of the context integration mechanism, we studied the latencies of neural edge signals, comparing the emergence of context-dependent definition of border ownership with the onset of local edge definition (contrast polarity; stereoscopic depth order). Single-neuron activity was recorded in areas V1 and V2 of Macaca mulatta under behaviorally induced fixation. Whereas local edge definition emerged immediately (<13 ms) after the edge onset response, the context-dependent signal was delayed by about 30 ms. To see if the context influence was mediated by horizontal fibers within cortex, we measured the latencies of border ownership signals for two conditions in which the relevant context information was located at different distances from the receptive field and compared the latency difference with the difference predicted from horizontal signal propagation. The prediction was based on the increase in cortical distance, computed from the mapping of the test stimuli in the cortex, and the known conduction velocities of horizontal fibers. The measured latencies increased with cortical distance, but much less than predicted by the horizontal propagation hypothesis. Probability calculations showed that an explanation of the context influence by horizontal signal propagation alone is highly unlikely, whereas mechanisms involving back projections from other extrastriate areas are plausible.
Concordance between perceptual and categorical repetition effects in the ventral visual stream
Authors: Fairhall Scott L. , Anzellotti Stefano , Pajtas Petra E. , Caramazza Alfonso
Published: May 2011

The process of object categorization is an integral part of human cognition. In the present study, we have used a repetition suppression paradigm to determine the degree to which the ventral visual cortex is sensitive to categorical relationships. By using images of animals and tools, suppression across perceptual (stimulus level) and categorical repetitions (basic level and domain level) was compared and contrasted across the domain-selective and hierarchical organization of the ventral visual stream. Both perceptual and categorical repetition effects were insensitive to domain-selective tuning, with suppression most prominent in regions responding maximally to images, irrespective of stimulus domain. Likewise, both perceptual and categorical repetition produced overlapping suppression across multiple regions of the visual hierarchy. Some divergent patterns were observed. The right superior temporal sulcus demonstrated repetition suppression only at the basic level (different examples of the same basic object), and the right anterior fusiform gyrus was sensitive to direct stimulus repetition but not basic-level categorical repetition. Because of the high concordance between the response profiles of perceptual and categorical repetition effects, we conclude they arise from a common cognitive mechanism.
Long-term systemic angiotensin II type 1 receptor blockade regulates mRNA expression of dorsomedial medulla renin-angiotensin system components
Authors: Gilliam-Davis Shea , Gallagher Patricia E. , Payne Valerie S. , Kasper Sherry O. , Tommasi Ellen N. , Westwood Brian M. , Robbins Michael E. , Chappell Mark C. , Diz Debra I.
Published: May 2011

In Fischer 344 (F344) rats, renin-angiotensin system (RAS) blockade for 1 yr with the angiotensin II type 1 (AT1) receptor blocker L-158,809 prevents age-related impairments in metabolic function, similar to transgenic rats with low glial angiotensinogen (Aogen). Brain RAS regulation may contribute to the benefits of long-term systemic AT1antagonism. We assessed the mRNA of RAS components in the dorsomedial medulla of F344 rats at 3 (young; n = 8) or 15 mo of age (old; n = 7) and in rats treated from 3 to 15 mo of age with 20 mg/l of the AT1receptor antagonist L-158,809 (Old+L; n = 6). Aogen and renin mRNA were lower in the young compared with old group. Angiotensin-converting enzyme (ACE) mRNA was lower in the old and Old+L compared with the young group. ACE2 and neprilysin expression were significantly higher in Old+L compared with young or old rats. AT1b, AT2, and Mas receptor mRNA were higher with treatment. Leptin receptor mRNA was lower in the old rats and this was prevented by L-158,809 treatment. Dual-specificity phosphatase 1 (DUSP1) mRNA was highest in the Old+L group. Aggregate correlate summation revealed a positive relationship for Mas receptor mRNA with food intake. The findings provide evidence for regulation of dorsomedial medullary renin and Aogen mRNA during aging. Long-term AT1receptor blockade increases the mRNA of the enzymes ACE2 and neprilysin and the MAS receptor, which could potentially shift the balance from ANG II to ANG-(1–7) and prevent age-related declines in the leptin receptor and its signaling pathway.
Understanding the Person through Narrative
Authors: Hall Joanne M. , Powell Jill
Published: May 2011

Mental health nurses need to know their clients at depth, and to comprehend their social contexts in order to provide holistic care. Knowing persons through their stories, narratives they tell, provides contextual detail and person-revealing characteristics that make them individuals. Narratives are an everyday means of communicating experience, and there is a place for storytelling in nearly all cultures. Thus narrative is a culturally congruent way to ascertain and understand experiences. This means the nurse should ask questions such as “How did that come about?” versus why questions. A narrative approach stands in contrast to a yes/no algorithmic process in conversing with clients. Eliciting stories illustrates the social context of events, and implicitly provides answers to questions of feeling and meaning. Here we include background on narrative, insights from narrative research, and clinical wisdom in explaining how narratively understanding the person can improve mental health nursing services. Implications for theory, practice, and research are discussed.
Transforming Arithmetic Asian Option PDE to the Parabolic Equation with Constant Coefficients
Authors: Elshegmani Zieneb Ali , Ahmad Rokiah Rozita , Jaaman Saiful Hafiza , Zakaria Roza Hazli
Published: May 2011

Arithmetic Asian options are difficult to price and hedge, since at present, there is no closed‐form analytical solution to price them. Transforming the PDE of the arithmetic the Asian option to a heat equation with constant coefficients is found to be difficult or impossible. Also, the numerical solution of the arithmetic Asian option PDE is not very accurate since the Asian option has low volatility level. In this paper, we analyze the value of the arithmetic Asian option with a new approach using means of partial differential equations (PDEs), and we transform the PDE to a parabolic equation with constant coefficients. It has been shown previously that the PDE of the arithmetic Asian option cannot be transformed to a heat equation with constant coefficients. We, however, approach the problem and obtain the analytical solution of the arithmetic Asian option PDE.
Comparison of the In Vivo Distribution of Four Different Annexin A5 Adducts in Rhesus Monkeys
Authors: McQuade Paul , Belanger Marie-Jose , Meng Xiangjun , Guenther Ilonka , Krause Stephen , Gonzalez Trotter Dinko , Reutelingsperger Chris , Hostetler Eric , Klimas Michael , Mehmet Huseyin , Cook Jacquelynn
Published: May 2011

Annexin A5 has been used for the detection of apoptotic cells, due to its ability to bind to phosphatidylserine (PS). Four different labeled Annexin A5 adducts were evaluated in rhesus monkey, with radiolabeling achieved via 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Of these adducts differing conjugation methods were employed which resulted in nonspecific radiolabeling (AxA5-I), or site-specific radiolabeling (AxA5-II). A nonbinding variant of Annexin A5 was also evaluated (AxA5-IINBV
), conjugation here was site specific. The fourth adduct examined had both specific and nonspecific conjugation techniques employed (AxA5-IImDOTA
). Blood clearance for each adduct was comparable, while appreciable uptake was observed in kidney, liver, and spleen. Significant differences in uptake of AxA5-I and AxA5-II were observed, as well as between AxA5-II and AxA5-IINBV
. No difference between AxA5-II and AxA5-IImDOTA
was observed, suggesting that conjugating DOTA nonspecifically did not affect the in vivo biodistribution of Annexin A5.
Development of a New Class of Thiocyanate-Free Cyclometalated Ruthenium(II) Complex for Sensitizing Nanocrystalline TiO2Solar Cells
Authors: Singh Surya Prakash , Islam Ashraful , Yanagida Masatoshi , Han Liyuan
Published: May 2011

We designed and developed a new class of thiocyanate-free cyclometalated ruthenium sensitizers for sensitizing nanocrystalline TiO2solar cells. This complex shows appreciably broad absorption range. Anchoring to nanocrystalline TiO2films for light to electrical energy conversion in regenerative photoelectrochemical cells achieves efficient sensitization to TiO2electrode. With this new sensitizer, there were a power conversion efficiency of 4.76%, a short-circuit photocurrent density of 11.21 mA/cm2, an open-circuit voltage of 0.62 V, and a fill factor of 0.68 obtained under standard AM 1.5 sunlight.
The Blood-Brain Barrier and Microvascular Water Exchange in Alzheimer's Disease
Authors: Anderson Valerie C. , Lenar David P. , Quinn Joseph F. , Rooney William D.
Published: May 2011

Alzheimer's disease (AD) is the most common form of dementia in the elderly. Although traditionally considered a disease of neurofibrillary tangles and amyloid plaques, structural and functional changes in the microvessels may contribute directly to the pathogenesis of the disease. Since vascular dysfunction often precedes cognitive impairment, understanding the role of the blood-brain barrier (BBB) in AD may be key to rational treatment of the disease. We propose that water regulation, a critical function of the BBB, is disturbed in AD and results in abnormal permeability and rates of water exchange across the vessel walls. In this paper, we describe some of the pathological events that may disturb microvascular water exchange in AD and examine the potential of a relatively new imaging technique, dynamic contrast-enhanced MRI, to quantify water exchange on a cellular level and thus serve as a probe of BBB integrity in AD.
Evaluation of the Effect of Consultant Characteristics on Telemedicine Diagnosis and Treatment
Authors: Bynum Ann B. , Irwin Cathy A.
Published: May 2011

This study examined teleconsultants' specialty, practice setting, type of employment, years and training in telemedicine to evaluate the effect of these characteristics on diagnoses and treatment. A postuse survey was conducted during 1998–2003 (n=454 consultations) in the University of Arkansas for Medical Sciences' Rural Hospital, Telehealth Project. There were 61 consultants who conducted the teleconsultations. The teleconsultants established a diagnosis in 121 consultations and reported a change in diagnoses in 29 consultations. The consultants established a treatment plan in 219 consultations and reported a change in the treatment plan in 100 consultations. Dermatologists were significantly more likely to establish (P<.01) and change (P=.005) the diagnosis and to establish a treatment plan (P=.03), when compared to all other specialties. Teleconsultants who were self-employed were significantly more likely to change the treatment plan (P=.012). The findings suggest that teleconsultants' characteristics can affect diagnoses and treatment in telemedicine.
Modeling and Syndromic Surveillance for Estimating Weather-Induced Heat-Related Illness
Authors: Perry Alexander G. , Korenberg Michael J. , Hall Geoffrey G. , Moore Kieran M.
Published: May 2011

This paper compares syndromic surveillance and predictive weather-based models for estimating emergency department (ED) visits for Heat-Related Illness (HRI). A retrospective time-series analysis of weather station observations and ICD-coded HRI ED visits to ten hospitals in south eastern Ontario, Canada, was performed from April 2003 to December 2008 using hospital data from the National Ambulatory Care Reporting System (NACRS) database, ED patient chief complaint data collected by a syndromic surveillance system, and weather data from Environment Canada. Poisson regression and Fast Orthogonal Search (FOS), a nonlinear time series modeling technique, were used to construct models for the expected number of HRI ED visits using weather predictor variables (temperature, humidity, and wind speed). Estimates of HRI visits from regression models using both weather variables and visit counts captured by syndromic surveillance as predictors were slightly more highly correlated with NACRS HRI ED visits than either regression models using only weather predictors or syndromic surveillance counts.
The Role of Proteasome Inhibition in Nonsmall Cell Lung Cancer
Authors: Escobar Mauricio , Velez Michel , Belalcazar Astrid , Santos Edgardo S. , Raez Luis E.
Published: May 2011

Lung cancer therapy with current available chemotherapeutic agents is mainly palliative. For these and other reasons there is now a great interest to find targeted therapies that can be effective not only palliating lung cancer or decreasing treatment‐related toxicity, but also giving hope to cure these patients. It is already well known that the ubiquitin‐proteasome system like other cellular pathways is critical for the proliferation and survival of cancer cells; thus, proteosome inhibition has become a very attractive anticancer therapy. There are several phase I and phase II clinical trials now in non‐small cell lung cancer and small cell lung cancer using this potential target. Most of the trials use bortezomib in combination with chemotherapeutic agents. This paper tends to make a state‐of‐the‐art review based on the available literature regarding the use of bortezomib as a single agent or in combination with chemotherapy in patients with lung cancer.
Outcome of Endometrial Cancer Stage IIIA with Adnexa or Serosal Involvement Only
Authors: Jobsen Jan J. , Naudin ten Cate Lambert , Lybeert Marnix L. M. , Scholten Astrid , van der Steen-Banasik Elzbieta M. , van der Palen Job , Stenfert Kroese Marika C. , Slot Annerie , Schutter Eltjo M. J. , Siesling Sabine
Published: May 2011

Objective. The aim of this study is to look at possible differences in outcome between serosa and adnexal involvement stage IIIA endometrial carcinoma.Methods. 67 patients with stage IIIA endometrial carcinoma were included, 46 with adnexal involvement and 21 with serosa. A central histopathological review was performed.Results. The 7-year locoregional failure rate was (LRFR) 2.2% for adnexal involvement and 16.0% for involvement of the serosa (P=.0522). The 7-year distant metastasis-free survival was 72.7% for adnexal involvement and 58.7% for serosa (P=.3994). The 7-year disease-specific survival (DSS) was 71.8% for patients with adnexal involvement and 75.4% for patients with serosa.Conclusion. Endometrial carcinoma stage IIIA with involvement of the adnexa or serosa showed to have a comparable disease-specific survival. Locoregional control was worse for serosa involvement compared to adnexa.
Delineation of a Cellular Hierarchy in Lung Cancer Reveals an Oncofetal Antigen Expressed on Tumor-Initiating Cells
Authors: Damelin Marc , Geles Kenneth G. , Follettie Maximillian T. , Yuan Ping , Baxter Michelle , Golas Jonathon , DiJoseph John F. , Karnoub Maha , Huang Shuguang , Diesl Veronica , Behrens Carmen , Choe Sung E. , Rios Carol , Gruzas Janet , Sridharan Latha , Dougher Maureen , Kunz Arthur , Hamann Philip R. , Evans Deborah , Armellino Douglas , Khandke Kiran , Marquette Kimberly , Tchistiakova Lioudmila , Boghaert Erwin R. , Abraham Robert T. , Wistuba Ignacio I. , Zhou Bin-Bing S.
Published: May 2011

Poorly differentiated tumors in non–small cell lung cancer (NSCLC) have been associated with shorter patient survival and shorter time to recurrence following treatment. Here, we integrate multiple experimental models with clinicopathologic analysis of patient tumors to delineate a cellular hierarchy in NSCLC. We show that the oncofetal protein 5T4 is expressed on tumor-initiating cells and associated with worse clinical outcome in NSCLC. Coexpression of 5T4 and factors involved in the epithelial-to-mesenchymal transition were observed in undifferentiated but not in differentiated tumor cells. Despite heterogeneous expression of 5T4 in NSCLC patient–derived xenografts, treatment with an anti-5T4 antibody–drug conjugate resulted in complete and sustained tumor regression. Thus, the aggressive growth of heterogeneous solid tumors can be blocked by therapeutic agents that target a subpopulation of cells near the top of the cellular hierarchy. Cancer Res; 71(12); 4236–46. ©2011 AACR.