bluuebunny/crossref_metadata_2025 huggingface dataset:
Microendmill Dynamics Including the Actual Fluted Geometry and Setup Errors—Part II: Model Validation and Application
Authors: Filiz Sinan , Ozdoganlar O. Burak
Published: June 2008

This paper presents a study to validate the microendmill dynamics model derived in Part I. A laser Doppler vibrometer system that is coupled with a microscope is used to measure the natural frequencies and mode shapes of nonrotating microendmills with different geometries. Free-free boundary conditions are obtained by suspending the microendmills using elastic bands. The dynamic excitation is delivered through miniature piezoelectric elements attached to the microendmill shanks. In each case, the model is compared to experimental results and solid-element finite-element (FE) models. To evaluate the model in the presence of rotational effects, the model is compared to an FE model. In most cases, the model was seen to capture the dynamic behavior of microendmills accurately. The validated model is used to investigate the effects of microendmill geometry, and radial and tilt runouts on the modal behavior of microendmills. Furthermore, possible geometric simplifications to fluted region are evaluated based on the accuracy of the predicted natural frequencies of the microendmills.
Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?
Authors: Albert J. , Aliu E. , Anderhub H. , Antonelli L. A. , Antoranz P. , Backes M. , Baixeras C. , Barrio J. A. , Bartko H. , Bastieri D. , Becker J. K. , Bednarek W. , Berger K. , Bernardini E. , Bigongiari C. , Biland A. , Bock R. K. , Bonnoli G. , Bordas P. , Bosch-Ramon V. , Bretz T. , Britvitch I. , Camara M. , Carmona E. , Chilingarian A. , Commichau S. , Contreras J. L. , Cortina J. , Costado M. T. , Covino S. , Curtef V. , Dazzi F. , De Angelis A. , De Cea del Pozo E. , de los Reyes R. , De Lotto B. , De Maria M. , De Sabata F. , Mendez C. Delgado , Dominguez A. , Dorner D. , Doro M. , Errando M. , Fagiolini M. , Ferenc D. , FernaÌndez E. , Firpo R. , Fonseca M. V. , Font L. , Galante N. , LoÌpez R. J. GarciÌa , Garczarczyk M. , Gaug M. , Goebel F. , Hayashida M. , Herrero A. , HoÌhne D. , Hose J. , Hsu C. C. , Huber S. , Jogler T. , Kneiske T. M. , Kranich D. , La Barbera A. , Laille A. , Leonardo E. , Lindfors E. , Lombardi S. , Longo F. , LoÌpez M. , Lorenz E. , Majumdar P. , Maneva G. , Mankuzhiyil N. , Mannheim K. , Maraschi L. , Mariotti M. , MartiÌnez M. , Mazin D. , Meucci M. , Meyer M. , Miranda J. M. , Mirzoyan R. , Mizobuchi S. , Moles M. , Moralejo A. , Nieto D. , Nilsson K. , Ninkovic J. , Otte N. , Oya I. , Panniello M. , Paoletti R. , Paredes J. M. , Pasanen M. , Pascoli D. , Pauss F. , Pegna R. G. , Perez-Torres M. A. , Persic M. , Peruzzo L. , Piccioli A. , Prada F. , Prandini E. , Puchades N. , Raymers A. , Rhode W. , RiboÌ M. , Rico J. , Rissi M. , Robert A. , RuÌgamer S. , Saggion A. , Saito T. Y. , Salvati M. , Sanchez-Conde M. , Sartori P. , Satalecka K. , Scalzotto V. , Scapin V. , Schmitt R. , Schweizer T. , Shayduk M. , Shinozaki K. , Shore S. N. , Sidro N. , Sierpowska-Bartosik A. , SillanpaÌaÌ A. , Sobczynska D. , Spanier F. , Stamerra A. , Stark L. S. , Takalo L. , Tavecchio F. , Temnikov P. , Tescaro D. , Teshima M. , Tluczykont M. , Torres D. F. , Turini N. , Vankov H. , Venturini A. , Vitale V. , Wagner R. M. , Wittek W. , Zabalza V. , Zandanel F. , Zanin R. , Zapatero J.
Published: June 2008

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.
A Phylogenomic Study of Birds Reveals Their Evolutionary History
Authors: Hackett Shannon J. , Kimball Rebecca T. , Reddy Sushma , Bowie Rauri C. K. , Braun Edward L. , Braun Michael J. , Chojnowski Jena L. , Cox W. Andrew , Han Kin-Lan , Harshman John , Huddleston Christopher J. , Marks Ben D. , Miglia Kathleen J. , Moore William S. , Sheldon Frederick H. , Steadman David W. , Witt Christopher C. , Yuri Tamaki
Published: June 2008

Deep avian evolutionary relationships have been difficult to resolve as a result of a putative explosive radiation. Our study examined ∼32 kilobases of aligned nuclear DNA sequences from 19 independent loci for 169 species, representing all major extant groups, and recovered a robust phylogeny from a genome-wide signal supported by multiple analytical methods. We documented well-supported, previously unrecognized interordinal relationships (such as a sister relationship between passerines and parrots) and corroborated previously contentious groupings (such as flamingos and grebes). Our conclusions challenge current classifications and alter our understanding of trait evolution; for example, some diurnal birds evolved from nocturnal ancestors. Our results provide a valuable resource for phylogenetic and comparative studies in birds.
Ordered Mesoporous Materials from Metal Nanoparticle–Block Copolymer Self-Assembly
Authors: Warren Scott C. , Messina Lauren C. , Slaughter Liane S. , Kamperman Marleen , Zhou Qin , Gruner Sol M. , DiSalvo Francis J. , Wiesner Ulrich
Published: June 2008

The synthesis of ordered mesoporous metal composites and ordered mesoporous metals is a challenge because metals have high surface energies that favor low surface areas. We present results from the self-assembly of block copolymers with ligand-stabilized platinum nanoparticles, leading to lamellar CCM-Pt-4 and inverse hexagonal (CCM-Pt-6) hybrid mesostructures with high nanoparticle loadings. Pyrolysis of the CCM-Pt-6 hybrid produces an ordered mesoporous platinum-carbon nanocomposite with open and large pores (≥10 nanometers). Removal of the carbon leads to ordered porous platinum mesostructures. The platinum-carbon nanocomposite has very high electrical conductivity (400 siemens per centimeter) for an ordered mesoporous material fabricated from block copolymer self-assembly.
Impact of Exogenous Sequences on the Characteristics of an Epidemic Type 2 Recombinant Vaccine-Derived Poliovirus
Authors: Riquet Franck B. , Blanchard Claire , Jegouic Sophie , Balanant Jean , Guillot Sophie , Vibet Marie-Anne , Rakoto-Andrianarivelo Mala , Delpeyroux Francis
Published: June 2008

Pathogenic circulating vaccine-derived polioviruses (cVDPVs) have become a major obstacle to the successful completion of the global polio eradication program. Most cVDPVs are recombinant between the oral poliovirus vaccine (OPV) and human enterovirus species C (HEV-C). To study the role of HEV-C sequences in the phenotype of cVDPVs, we generated a series of recombinants between a Madagascar cVDPV isolate and its parental OPV type 2 strain. Results indicated that the HEV-C sequences present in this cVDPV contribute to its characteristics, including pathogenicity, suggesting that interspecific recombination contributes to the phenotypic biodiversity of polioviruses and may favor the emergence of cVDPVs.
Stream fish occurrence in response to impervious cover, historic land use, and hydrogeomorphic factors
Authors: Wenger Seth J. , Peterson James T. , Freeman Mary C. , Freeman Byron J. , Homans D. David
Published: June 2008

We evaluated competing models explaining the occurrence of five stream fishes in an urbanizing watershed to determine the relative importance of (a) impervious surface and other indicators of current land use, (b) historic land use (e.g., agriculture, impoundments), and (c) hydrogeomorphic characteristics (e.g., stream size, elevation, geology). For four of five species, the best-supported models were those that included both current effective impervious cover and historic land use predictor variables, although models with only effective impervious cover were equally well supported for two of those species. For the best-supported models for three species, occurrence probability was predicted to approach zero at levels of development equivalent to about 2%–4% effective impervious cover in the surrounding region. Data were drawn from 357 fish collections made in the Etowah River basin, Georgia, USA, between 1998 and 2003 and analyzed using hierarchical logistic regression accounting for imperfect species detection. This is the first study we know of to examine the response of individual fish species to both increasing impervious cover and historic land use. Such individual species assessments will be increasingly necessary to guide policies for managing urban effects and preventing extirpations of sensitive species.
Population structure of striped marlin (Kajikia audax) in the Pacific Ocean based on analysis of microsatellite and mitochondrial DNA
Authors: McDowell Jan R. , Graves John E.
Published: June 2008

Genetic variation was surveyed at five microsatellite loci and the mitochondrial control region (819 bp) to test for the presence of genetic stock structure in striped marlin ( Kajikia audax ) collections taken from seven locations throughout the Pacific Ocean. Temporal replicates separated by 9 years were taken off Japan, and three temporal samples spanning 11 years were collected off the coast of eastern Australia. Analyses of multilocus microsatellite genotypes and mitochondrial control region sequences showed no significant heterogeneity among collections taken from the same location in different years; however, significant spatial genetic heterogeneity was observed across all samples for microsatellite markers (FST= 0.013, P < 0.001). Mitochondrial control region sequences were not different across all samples (ΦST= –0.01, P = 0.642). Analyses of molecular variance (AMOVA) revealed significant genetic differentiation between geographic regions for both microsatellite and mitochondrial markers. These results suggest the presence of genetically discrete populations within the Pacific Ocean and are supported by both the results of tagging studies, which show limited dispersal, and the presence of geographically separated spawning grounds.
Effect of ambient oxygen on growth and reproduction in Nile tilapia (Oreochromis niloticus)
Authors: Kolding Jeppe , Haug Lise , Stefansson Sigurd
Published: June 2008

Growth, size at maturity, gonadosomatic index (GSI), egg size, and absolute fecundity of Nile tilapia ( Oreochromis niloticus ) were significantly affected by oxygen levels (1.5 ± 1.0, 2.8 ± 1.4, and 6.0 ± 1.8 mg·L–1) in a controlled experiment designed to test the hypothesis (D. Pauly. 1984. J. Cons. Int. Explor. Mer, 41: 280–284) that O2 is the controlling factor for the transition from juvenile to adult in fish, in general, in the context of phenotypic life history plasticity and “stunting” in tilapias. Size at maturity and the estimated asymptotic size decreased with decreasing O2 concentration, as predicted by Pauly’s hypothesis. All fish matured at the same age (18 weeks old), which is in contrast to conventional definitions of stunting. This finding challenges the suggested plasticity in age at first maturity for tilapia. The results also challenge the hypothesis that stunting is a unique recruitment mechanism, as the smaller fish in the group with low oxygen concentration produced smaller and fewer eggs than the larger fish in the group with high oxygen concentration.
Properties of an artificially cemented clay
Authors: Fischer K. P. , Andersen K. H. , Moum J.
Published: June 2008

A high clay strength and apparent preconsolidation may be a result of chemical processes such as cementation at the contact points of the clay particles. In order to study some of the mechanical properties of a cemented clay two artificially cemented simple shear samples were produced and tested. Their engineering properties were compared to those of non-cemented clay samples with a real preloading. The cementing agent that was introduced into the sample was CaCO3. This was achieved by a sequence of treatments of CaCl2, Na2CO3, and original pore water. The different solutions were transported into the samples by diffusion. The cementation process took 90 days. The average amount of CaCO3 introduced into the two samples was 3.3 and 4.2%, respectively. By electron microscope techniques it was revealed that calcium carbonate was precipitated in spots of 5–10 μm diameter. One of the samples was run with undrained static loading. The other sample was first subjected to undrained cyclic loading and then to undrained static loading. Cementation increased the horizontal shear stress at failure by 35–40%. This corresponds to an apparent overconsolidation ratio of about 1.75. Both for static and cyclic loading the engineering properties were essentially independent of whether their high strength was achieved by cementation or by a real preloading.
Archival material and site investigations
Authors: Legget R. F. , Burn K. N.
Published: June 2008

The prediction of subsurface conditions at building sites is a prime responsibility of the geotechnical engineer, and the improved accuracy with which he can make such predictions is a continual challenge. Information is derived primarily by studying the local geological and groundwater conditions, and from sampling and testing of soil and rock. In most instances, this procedure provides adequate assessment of the conditions likely to be encountered during construction. Increasingly, however, particularly in towns and cities, building sites are located where the natural terrain may have been altered significantly by earlier human activity, such as the erection and demolition of buildings and other structures, excavation and subsequent filling of pits and quarries, and the reclamation of land at waterfronts. The remains of these activities are now buried and hidden from view but they may present unusual and sometimes unexpected conditions, which can complicate the construction of new foundations and lead to increased costs for unanticipated work. Records of these earlier activities are sometimes available in drawings, maps, and paintings housed in local archives, and it is the thesis of this paper that these often constitute a useful tool in subsurface investigations—one that is too often overlooked. To support this contention, several case histories illustrating valuable information derived from archival material are cited, including examples from Canada, the United States, and Europe. Key words: archival material, site investigation, anthropogenic material.
Catastrophic lake drainage within the Homathko River basin, British Columbia
Authors: Blown Iain , Church Michael
Published: June 2008

Three distinct phenomena related to sudden lake drainage, which occurred in a restricted area within the southern Coast Mountains of British Columbia, are described: (i) moraine breaching by solitary wave action following an icefall into a lake; (ii) failure of a glacier ice dam by flotation and melting to produce a ‘glacier outburst’ flood or ‘jökulhlaup;’ (iii) debris torrent following a moraine breach. The possibility for a fourth failure phenomenon: moraine failure by piping, is discussed. A first attempt to develop practical hazard evaluation methods before the event, which relies on simple scale relations or index relations developed from experience of events elsewhere, is presented. Key words: dam break, debris flow, hazard evaluation, jökulhlaup, lakes, lake drainage.
COMPACT OPERATORS AND THE PLURIHARMONIC BEREZIN TRANSFORM
Authors: BAUER WOLFRAM , FURUTANI KENRO
Published: June 2008

For a series of weighted Bergman spaces over bounded symmetric domains in ℂn, it has been shown by Axler and Zheng [1]; Englis [10] that the compactness of Toeplitz operators with bounded symbols can be characterized via the boundary behavior of its Berezin transform B a . In case of the pluriharmonic Bergman space, the pluriharmonic Berezin transform B ph fails to be one-to-one in general and even has non-compact operators in its kernel. From this point of view, perhaps surprisingly we show that via B ph the same characterization of compactness holds for Toeplitz operators on the pluriharmonic Fock space.
THE BIG CHERN CLASSES AND THE CHERN CHARACTER
Authors: RAMADOSS AJAY C.
Published: June 2008

Let X be a smooth scheme over a field of characteristic 0. The Atiyah class of the tangent bundle TXof X equips TX[-1] with the structure of a Lie algebra object in the derived category D+(X) of bounded below complexes of [Formula: see text] modules with coherent cohomology [6]. We lift this structure to that of a Lie algebra object [Formula: see text] in the category of bounded below complexes of [Formula: see text] modules in Theorem 2. The "almost free" Lie algebra [Formula: see text] is equipped with Hochschild coboundary. There is a symmetrization map [Formula: see text] where [Formula: see text] is the complex of polydifferential operators with Hochschild coboundary. We prove a theorem (Theorem 1) that measures how I fails to commute with multiplication. Further, we show that [Formula: see text] is the universal enveloping algebra of [Formula: see text] in D+(X). This is used to interpret the Chern character of a vector bundle E on X as the "character of a representation" (Theorem 4). Theorems 4 and 1 are then exploited to give a formula for the big Chern classes in terms of the components of the Chern character.
LIQUID FOAM DRAINAGE: AN OVERVIEW
Authors: SUN QICHENG , TAN LIANGHUI , WANG GUANGQIAN
Published: June 2008

Liquid foams are concentrated dispersions of gas bubbles in a small amount of surfactant solution, which are perpetually out of equilibrium systems. The process of liquid draining through networks of Plateau borders in a fresh foam is so-called foam drainage, as a result of both gravitational and capillary forces, which has great effect on the stability of foams. From the view of foam physics and dynamics, this paper briefly introduces foam structure and major lifetime limiting factors of foam. The substantial progress on the theory of drainage, measuring techniques for liquid fractions, drainage in both one dimension and two dimensions, and drainage in microgravity circumstances are overviewed throughout. Remaining tasks are discussed and a multiscale methodology for foam drainage is proposed for future investigations.
EXACT RESULTS OF THE MIXED-SPIN ISING MODEL ON A DECORATED SQUARE LATTICE WITH TWO DIFFERENT DECORATING SPINS OF INTEGER MAGNITUDES
Authors: ČANOVÁ LUCIA , STREČKA JOZEF , JAŠČUR MICHAL
Published: June 2008

The mixed-spin Ising model on a decorated square lattice with two different decorating spins of integer magnitudes S B = 1 and S C = 2 placed on horizontal and vertical bonds of the lattice, respectively, is examined within an exact analytical approach based on the generalized decoration–iteration mapping transformation. Besides the ground-state analysis, finite-temperature properties of the system are investigated in detail. The most interesting numerical result to emerge from our study relates to a striking critical behavior of the spontaneously ordered "quasi-1D" spin system. It was found that this quite remarkable spontaneous order arises when one sublattice of the decorating spins (either S B or S C ) tends toward their "nonmagnetic" spin state S = 0, and the system becomes disordered only upon further single-ion anisotropy strengthening. In particular, the effect of single-ion anisotropy upon the temperature dependence of the total and sublattice magnetization is investigated.
A NOVEL ASYMPTOTIC SOLUTION OF ONE NONLINEAR PROBLEM OF FILTERING
Authors: OSTAPENKO VICTOR A. , AWREJCEWICZ JAN
Published: June 2008

A boundary value problem associated with filtering governed by differential equations with time dependent coefficients and exhibiting a weak nonlinearity is solved. Namely, the boundary value problem is split into two independent boundary problems, i.e., that of Goursat for the concentration of a sorbate and that absorbed by a sorbent. Then each of the formulated problems is solved separately applying the Riemann transformation.
PARAMETER IDENTIFICATION AND ADAPTIVE SYNCHRONIZATION CONTROL OF A LORENZ-LIKE SYSTEM
Authors: WANG XINGYUAN , WANG YONG
Published: June 2008

This paper analyzes the synchronization control of new chaotic systems called Lorenz-like systems. Based on the Lyapunov stability theory, an adaptive controller and a parameter update rule are designed. It is proved that the controller and update rule not only achieve self-synchronization of Lorenz-like systems but can also make the Lorenz-like system asymptotically synchronized with the Rössler system, and further identify the uncertain system parameters. Numerical simulations have shown the effectiveness of the adaptive controller.
AXIAL COUETTE FLOW OF AN ELECTRICALLY CONDUCTING FLUID IN AN ANNULUS
Authors: HAYAT T. , MOMONIAT E. , MAHOMED F. M.
Published: June 2008

The unsteady flow in an annulus due to a velocity applied to one of the boundaries is addressed. The fluid considered is non-Newtonian, incompressible and electrically conducting. The strength of the applied magnetic field is time-dependent. Both analytical and numerical approaches are presented and compared. The nonlinear effects on the velocity profile are shown.
THE INFLUENCE OF NONLOCAL COULOMB INTERACTION ON GROUND-STATE PROPERTIES OF THE FALICOV–KIMBALL MODEL IN ONE AND TWO DIMENSIONS
Authors: ČENČARIKOVÁ HANA , FARKAŠOVSKÝ PAVOL , ŽONDA MARTIN
Published: June 2008

A combination of small-cluster exact diagonalizations and a well-controlled approximative method is used to study the ground states of the Falicov–Kimball model extended by nonlocal Coulomb interaction (Unon). It is shown that the ground-state phase diagram as well as the picture of valence and metal–insulator transitions found for the conventional Falicov–Kimball model are strongly changed when the nonlocal Coulomb interaction is added. This is illustrated for three selected values of the on-site Coulomb interaction (U) that represent typical behaviors of the model for small, intermediate and strong interactions. A number of remarkable results are found: (i) the phase separation takes place for a wide range of Unonin all three interaction limits; (ii) in the weak and intermediate coupling limit, the model exhibits the nonlocal Coulomb interaction–induced insulator–metal transition; (iii) depending on the value of Unon, the model is able to describe both the continuous and the discontinuous changes of the f-electron occupation number; (iv) new types of inhomogeneous charge ordering (including various types of axial and diagonal stripes) are observed for nonzero Unon.
DIMENSIONAL TRANSITIONS OF DENSITY OF STATES AND HEAT CAPACITY IN SPHERICAL QUANTUM DOTS
Authors: LEE SEUNG JOO , JEON HEE CHANG , KANG TAE WON , SOUMA SATOFUMI
Published: June 2008

We evaluate analytically and numerically the density of states (DOS) and the heat capacity in a spherical quantum dot formed by a spherical thin barrier. The control of the spherical barrier thickness or the potential barrier height is found to cause the dimensional transition from the three-dimensional (3D) behavior to the quasi-zero dimensional (Q0D) behavior in the DOS and the heat capacity. When the barrier is thick enough, the DOS shows the Q0D-like behavior but when the barrier is thin enough to allow electrons to tunnel through it, the temperature dependence of the heat capacity exhibits quite a distinct behavior depending on the electron density. Explicit numerical plots are given in the low density regime.
A NEW NON-DIMENSIONAL NUMBER FOR FRICTION CHARACTERISTIC OF FLOW IN MICRO-CHANNEL WITH SLIP
Authors: ZHANG T. T. , JIA L. , WANG Z. C.
Published: June 2008

A three-dimensional compressible numerical model of micro-channel is established with consideration of the effect of velocity slip near walls. Meanwhile the gas viscosity is modified based on the Knudsen number using Veijola's model. The model is proved to be credible by comparing with analytical data. A new non-dimensional parameter relative slip length Ls/Dh is found to be very useful for describing friction characteristic for compressible flow with slip in micro-scale. The correlation for fRe with this new non-dimensional parameter Ls/Dh is suggested.
RADICALS WITH THE α-AMITSUR PROPERTY
Authors: TUMURBAT SODNOMKHORLOO , WISBAUER ROBERT
Published: June 2008

A radical γ of rings is said to have the Amitsur property if for all rings A, γ(A[X]) = (γ(A[X]) ∩ A)[X]. Let Xα denote a set of indeterminates of cardinality α. We say that γ has the α-Amitsur property if for all rings A, γ(A[Xα]) = (γ(A[Xα]) ∩ A)[Xα]. We study properties of this type of radicals and show relationships with other known radicals for rings.

A ring A is said to be an absolute γ-ring if A[x1,…, xn] ∈ γ, for any n ∈ ℕ. We show that A is an absolute 𝔾-ring for the Brown–McCoy radical 𝔾, if and only if A is in the radical class S determined by the unitary strongly prime rings. Moreover, A is an absolute nil ring if and only if A is an absolute J-ring, where J denotes the Jacobson radical.
ON THE UNITS OF THE INTEGRAL GROUP RING Z[G × Cp]
Authors: LOW RICHARD M.
Published: June 2008

Describing the group of units U(ZG) of the integral group ring ZG, for a finite group G, is a classical and open problem. In this paper, it is shown that U(Z[G × Cp]) = M ⋊ U(ZG), a semi-direct product where M is a certain subgroup of U(Z[ζ]G) and p prime. For p = 2, this structure theorem is applied to give precise descriptions of U(ZG) for a non-abelian group G of order 32, G = C10, and G = C8 × C2.
Adaptation by alternative RNA splicing of slow troponin T isoforms in type 1 but not type 2 Charcot-Marie-Tooth disease
Authors: Larsson Lars , Wang Xin , Yu Fushun , Höök Peter , Borg Kristian , Chong Stephen M. , Jin J.-P.
Published: June 2008

Slow troponin T (TnT) plays an indispensable role in skeletal muscle function. Alternative RNA splicing in the NH2-terminal region produces high-molecular-weight (HMW) and low-molecular-weight (LMW) isoforms of slow TnT. Normal adult slow muscle fibers express mainly HMW slow TnT. Charcot-Marie-Tooth disease (CMT) is a group of inherited peripheral polyneuropathies caused by various neuronal defects. We found in the present study that LMW slow TnT was significantly upregulated in demyelination form type 1 CMT (CMT1) but not axonal form type 2 CMT (CMT2) muscles. Contractility analysis showed an increased specific force in single fibers isolated from CMT1 but not CMT2 muscles compared with control muscles. However, an in vitro motility assay showed normal velocity of the myosin motor isolated from CMT1 and CMT2 muscle biopsies, consistent with their unchanged myosin isoform contents. Supporting a role of slow TnT isoform regulation in contractility change, LMW and HMW slow TnT isoforms showed differences in the molecular conformation in conserved central and COOH-terminal regions with changed binding affinity for troponin I and tropomyosin. In addition to providing a biochemical marker for the differential diagnosis of CMT, the upregulation of LMW slow TnT isoforms under the distinct pathophysiology of CMT1 demonstrates an adaptation of muscle function to neurological disorders by alternative splicing modification of myofilament proteins.
Voluntary exercise improves insulin sensitivity and adipose tissue inflammation in diet-induced obese mice
Authors: Bradley Richard L. , Jeon Justin Y. , Liu Fen-Fen , Maratos-Flier Eleftheria
Published: June 2008

Exercise promotes weight loss and improves insulin sensitivity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Obesity correlates with increased production of inflammatory cytokines, which in turn, contributes to systemic insulin resistance. To test the hypothesis that exercise mitigates this inflammatory response, thereby improving insulin sensitivity, we developed a model of voluntary exercise in mice made obese by feeding of a high fat/high sucrose diet (HFD). Over four wk, mice fed chow gained 2.3 ± 0.3 g, while HFD mice gained 6.8 ± 0.5 g. After 4 wk, mice were subdivided into four groups: chow-no exercise, chow-exercise, HFD-no exercise, HFD-exercise and monitored for an additional 6 wk. Chow-no exercise and HFD-no exercise mice gained an additional 1.2 ± 0.3 g and 3.3 ± 0.5 g respectively. Exercising mice had higher food consumption, but did not gain additional weight. As expected, GTT and ITT showed impaired glucose tolerance and insulin resistance in HFD-no exercise mice. However, glucose tolerance improved significantly and insulin sensitivity was completely normalized in HFD-exercise animals. Furthermore, expression of TNF-α, MCP-1, PAI-1 and IKKβ was increased in adipose tissue from HFD mice compared with chow mice, whereas exercise reversed the increased expression of these inflammatory cytokines. In contrast, expression of these cytokines in liver was unchanged among the four groups. These results suggest that exercise partially reduces adiposity, reverses insulin resistance and decreases adipose tissue inflammation in diet-induced obese mice, despite continued consumption of HFD.
Measurement of pulsatile insulin secretion in the rat: direct sampling from the hepatic portal vein
Authors: Matveyenko Aleksey V. , Veldhuis Johannes D. , Butler Peter C.
Published: June 2008

It has previously been shown that insulin is secreted in discrete secretory bursts by sampling directly from the portal vein in the dog and humans. Deficient pulsatile insulin secretion is the basis for impaired insulin secretion in type 2 diabetes. However, while novel genetically modified disease models of diabetes are being developed in rodents, no validated method for quantifying pulsatile insulin secretion has been established for rodents. To address this we 1) developed a novel rat model with chronically implanted portal vein catheters, 2) established the parameters to permit deconvolution of portal vein insulin concentrations profiles to measure insulin secretion and resolve its pulsatile components, and 3) measured total and pulsatile insulin secretion compared with that in the dog, the species in which this sampling and deconvolution approach was validated for quantifying pulsatile insulin secretion. In rats, portal vein catheter patency and function were maintained for periods up to 2–3 wk with no postoperative complications such as catheter tract infection. Rat portal vein insulin concentration profiles in the fasting state revealed distinct insulin oscillations with a periodicity of ∼5 min and an amplitude of up to 600 pmol/l, which was remarkably similar to that in the dogs and in humans. Deconvolution analysis of portal vein insulin concentrations revealed that the majority of insulin (∼70%) in the rat is secreted in distinct insulin pulses occurring at ∼5-min intervals. This model therefore permits direct accurate measurments of pulsatile insulin secretion in a relatively inexpensive animal. With increased introduction of genetically modified rat models will be an important tool in elucidating the underlying mechanisms of impaired pulsatile insulin secretion in diabetes.
Effects of adlay hull extracts on uterine contraction and Ca2+mobilization in the rat
Authors: Hsia Shih-Min , Kuo Yueh-Hsiung , Chiang Wenchang , Wang Paulus S.
Published: June 2008

Dysmenorrhea is directly related to elevated PGF2αlevels. It is treated with nonsteroid antiinflammatory drugs (NSAIDs) in Western medicine. Since NSAIDs produce many side effects, Chinese medicinal therapy is considered as a feasible alternative medicine. Adlay ( Coix lachryma-jobi L. var. ma-yuen Stapf.) has been used as a traditional Chinese medicine for treating dysmenorrhea. However, the relationship between smooth muscle contraction and adlay extracts remains veiled. Therefore, we investigated this relationship in the rat uterus by measuring uterine contraction activity and recording the intrauterine pressure. We studied the in vivo and in vitro effects of the methanolic extracts of adlay hull (AHM) on uterine smooth muscle contraction. The extracts were fractionated using four different solvents: water, 1-butanol, ethyl acetate, and n-hexane; the four respective fractions were AHM-Wa, AHM-Bu, AHM-EA, and AHM-Hex. AHM-EA and its subfractions (175 μg/ml) inhibited uterine contractions induced by PGF2α, the Ca2+channel activator Bay K 8644, and high K+in a concentration-dependent manner in vitro. AHM-EA also inhibited PGF2α-induced uterine contractions in vivo; furthermore, 375 μg/ml of AHM-EA inhibited the Ca2+-dependent uterine contractions. Thus 375 μg/ml of AHM-EA consistently suppressed the increases in intracellular Ca2+concentrations induced by PGF2αand high K+. We also demonstrated that naringenin and quercetin are the major pure chemical components of AHM-EA that inhibit PGF2α-induced uterine contractions. Thus AHM-EA probably inhibited uterine contraction by blocking external Ca2+influx, leading to a decrease in intracellular Ca2+concentration. Thus adlay hull may be considered as a feasible alternative therapeutic agent for dysmenorrhea.
Lower uterine artery blood flow and higher endothelin relative to nitric oxide metabolite levels are associated with reductions in birth weight at high altitude
Authors: Julian Colleen Glyde , Galan Henry L. , Wilson Megan J. , DeSilva Wendy , Cioffi-Ragan Darleen , Schwartz Joel , Moore Lorna G.
Published: June 2008

Reduced uteroplacental blood flow is hypothesized to play a key role in altitude-associated fetal growth restriction. It is unknown whether reduced blood flow is a cause or consequence of reduced fetal size. We asked whether determinants of uteroplacental blood flow were altered prior to reduced fetal growth and whether vasoactive and/or angiogenic factors were involved. Women residing at low (LA; 1600 m, n = 18) or high altitude (HA; 3100 m, n = 25) were studied during pregnancy (20, 30, and 36 wk ) and 4 mo postpartum (PP) using Doppler ultrasound. In each study, endothelin (ET-1), nitric oxide metabolites (NO x), soluble fms-like tyrosine kinase (sFlt-1) and placental growth factor (PlGF) levels were quantified. At HA, birth weights were lower ( P < 0.01) and small-for-gestational age was more common ( P < 0.05) compared with LA. HA was associated with lower uterine artery (UA) diameter ( P < 0.01) and blood flow ( P < 0.05). Altitude did not affect ET-1, sFlt-1 or PlGF; however, ET-1/NO x was greater and NO x lower during pregnancy and PP at HA vs. LA. ET-1/NO x was negatively associated with birth weight (20 wk, P < 0.01; 36 wk, P = 0.05) at LA and HA combined. At HA, UA blood flow (30 wk) was positively associated with birth weight (†). UA blood flow and ET-1/NO x levels accounted for 45% (20 wk) and 32% (30 wk) of birth weight variation at LA and HA combined, primarily attributed to effects at HA. We concluded that elevated ET-1/NO x and altered determinants of uteroplacental blood flow occur prior to altitude-associated reductions in fetal growth, and therefore, they are likely a cause rather than a consequence of smaller fetal size.
Intrarenal angiotensin II and angiotensinogen augmentation in chronic angiotensin II-infused mice
Authors: Gonzalez-Villalobos Romer A. , Seth Dale M. , Satou Ryousuke , Horton Heather , Ohashi Naro , Miyata Kayoko , Katsurada Akemi , Tran Duy V. , Kobori Hiroyuki , Navar L. G.
Published: June 2008

The objectives of this study were to determine the effects of chronic angiotensin II (ANG II) infusions on ANG II content and angiotensinogen expression in the mouse kidney and the role of the angiotensin II type 1 receptor (AT1R) in mediating these changes. C57BL/6J male mice were subjected to ANG II infusions at doses of 400 or 1,000 ng·kg−1·min−1either alone or with an AT1R blocker (olmesartan; 3 mg·kg−1·day−1) for 12 days. Systolic and mean arterial pressures were determined by tail-cuff plethysmography and radiotelemetry. On day 13, blood and kidneys were collected for ANG II determinations by radioimmunoanalysis and intrarenal angiotensinogen expression studies by quantitative RT-PCR, Western blotting, and immunohistochemistry. ANG II infusions at the low dose elicited progressive increases in systolic blood pressure (135 ± 2.5 mmHg). In contrast, the high dose induced a rapid increase (152 ± 2.5, P < 0.05 vs. controls, 109 ± 2.8). Renal ANG II content was increased by ANG II infusions at the low dose (1,203 ± 253 fmol/g) and the high dose (1,258 ± 173) vs. controls (499 ± 40, P < 0.05). Kidney angiotensinogen mRNA and protein were increased only by the low dose to 1.13 ± 0.02 and 1.26 ± 0.10, respectively, over controls (1.00, P < 0.05). These effects were not observed in mice infused at the high dose and those receiving olmesartan. The results indicate that chronic ANG II infusions augment mouse intrarenal ANG II content with AT1R-dependent uptake occurring at both doses, but only the low dose of infusion, which elicited a slow progressive response, causes an AT1R-dependent increase in intrarenal angiotensinogen expression.
Doing Without Learning: Stimulation of the Frontal Eye Fields and Floccular Complex Does Not Instruct Motor Learning in Smooth Pursuit Eye Movements
Authors: Heuer Hilary W. , Tokiyama Stefanie , Lisberger Stephen G.
Published: June 2008

Under natural conditions, motor learning is instructed by sensory feedback. We have asked whether sensory signals that indicate motor errors are necessary to instruct learning or if the motor signals related to movements normally driven by sensory error signals would be sufficient. We measured eye movements in trained rhesus monkeys while employing electrical microstimulation of the floccular complex of the cerebellum and the smooth eye movement region of the frontal eye fields to alter ongoing pursuit eye movements. Repeated electrical stimulation at fixed times after the onset of target motion and pursuit failed to cause any learning that was retained beyond the time period used to instruct learning. Learning was not uncovered when the target was stabilized with respect to the moving eye to prevent competition between instructive signals created by electrical stimulation and visual image motion signals evoked when stimulation drove the eye away from the tracking target. We suggest that signals emanating from motor-related structures in the pursuit circuit do not instruct learning. Instead, instructive sensory error signals seem to be necessary.
Complex Temporal Response Patterns With a Simple Retinal Circuit
Authors: Werner Birgit , Cook Paul B. , Passaglia Christopher L.
Published: June 2008

The retina can respond to a wide array of features in the visual input. It was recently reported that the retina can even recognize complicated temporal input patterns and signal violations in the patterns. When a sequence of flashes was presented, ganglion cells exhibited a variety of firing profiles and many cells showed an “omitted stimulus response” (OSR), in which they fired strongly if a flash in the sequence was omitted. We examined the synaptic origins of the OSR by recording excitatory synaptic currents from ganglion cells in the salamander retina in response to periodic flash sequences. Consistent with previous spike recordings, ganglion cells exhibited an OSR in their current response and the OSR shifted in time with a change in flash frequency such that it could predict when the next flash should have occurred. Although the behavior may seem sophisticated, we show that a simple linear–nonlinear model with a spike threshold can account for the OSR in on ganglion cells and that the variety of complex firing profiles seen in other ganglion cells can be explained by adding contributions from the off pathway. We discuss the physiological and simulation results and their implications for understanding retinal mechanisms of visual information processing.
Using a Model to Assess the Role of the Spatiotemporal Pattern of Inhibitory Input and Intrasegmental Electrical Coupling in the Intersegmental and Side-to-Side Coordination of Motor Neurons by the Leech Heartbeat Central Pattern Generator
Authors: García Paul S. , Wright Terrence M. , Cunningham Ian R. , Calabrese Ronald L.
Published: June 2008

Previously we presented a quantitative description of the spatiotemporal pattern of inhibitory synaptic input from the heartbeat central pattern generator (CPG) to segmental motor neurons that drive heartbeat in the medicinal leech and the resultant coordination of CPG interneurons and motor neurons. To begin elucidating the mechanisms of coordination, we explore intersegmental and side-to-side coordination in an ensemble model of all heart motor neurons and their known synaptic inputs and electrical coupling. Model motor neuron intrinsic properties were kept simple, enabling us to determine the extent to which input and electrical coupling acting together can account for observed coordination in the living system in the absence of a substantive contribution from the motor neurons themselves. The living system produces an asymmetric motor pattern: motor neurons on one side fire nearly in synchrony (synchronous), whereas on the other they fire in a rear-to-front progression (peristaltic). The model reproduces the general trends of intersegmental and side-to-side phase relations among motor neurons, but the match with the living system is not quantitatively accurate. Thus realistic (experimentally determined) inputs do not produce similarly realistic output in our model, suggesting that motor neuron intrinsic properties may contribute to their coordination. By varying parameters that determine electrical coupling, conduction delays, intraburst synaptic plasticity, and motor neuron excitability, we show that the most important determinant of intersegmental and side-to-side phase relations in the model was the spatiotemporal pattern of synaptic inputs, although phasing was influenced significantly by electrical coupling.
Crystallochemistry and structural studies of two newly CaSb0.50Fe1.50(PO4)3 and Ca0.50SbFe(PO4)3 Nasicon phases
Authors: Aatiq Abderrahim , Tigha My Rachid , Hassine Rabia , Saadoune Ismael
Published: June 2008

Crystallographic structures of two new orthophosphates Ca0.50SbFe(PO4)3 and CaSb0.50Fe1.50(PO4)3 obtained by conventional solid state reaction techniques at 900 °C, were determined at room temperature from X-ray powder diffraction using Rietveld analysis. The two compounds belong to the Nasicon structural family. The space group is R3 for Ca0.50SbFe(PO4)3 and R3c for CaSb0.50Fe1.50(PO4)3. Hexagonal cell parameters for Ca0.50SbFe(PO4)3 and CaSb0.50Fe1.50(PO4)3 are: a=8.257(1) Å, c=22.276(2) Å, and a=8.514(1) Å, c=21.871(2) Å, respectively. Ca2+ and vacancies in {[Ca0.50]3a[◻0.50]3b}M1SbFe(PO4)3 are ordered within the two positions, 3a and 3b, of M1 sites. Structure refinements show also a quasi-ordered distribution of Sb5+ and Fe3+ ions within the Nasicon framework. Thus, in {[Ca0.50]3a[◻0.50]3b}M1SbFe(PO4)3, each Ca(3a)O6 octahedron shares two faces with two Fe3+O6 octahedra and each vacancy (◻(3b)O6) site is located between two Sb5+O6 octahedra. In [Ca]M1Sb0.50Fe1.50(PO4)3 compound (R3c space group), all M1 sites are occupied by Ca2+ and the Sb5+ and Fe3+ ions are randomly distributed within the Nasicon framework.
X-ray powder diffraction data for botallackite
Authors: Krause Werner
Published: June 2008

Botallackite, Cu2(OH)3Cl, from the Botallack mining area in Cornwall, United Kingdom, has been reinvestigated regarding physical, optical, chemical, and X-ray powder diffraction data. It forms emerald-green tabular crystals slightly elongated along [010] with {001} (dominant), {100}, {010}, and {011}. Botallackite is biaxial positive, 2V=70(2)°, the optical orientation is Y∧c 22(2)° (in obtuse β), Z=b. Electron-microprobe analyses gave CuO 73.26, ZnO 0.22, Cl 16.80, H2O (calc) 12.37, total 102.65, less O=Cl 3.79, total 98.86 wt %, corresponding to the empirical formula Cu1.99Zn0.01(OH)2.97Cl1.03 (based on four anions). Unit cell parameters refined from X-ray powder diffraction data are a 5.7155(5), b 6.1255(6), c 5.6336(4) Å, β 93.090(8), V 196.95(2)Å3,Z=2.
A Phase I and Pharmacokinetic Study of the Oral Histone Deacetylase Inhibitor, MS-275, in Patients with Refractory Solid Tumors and Lymphomas
Authors: Gore Lia , Rothenberg Mace L. , O'Bryant Cindy L. , Schultz Mary Kay , Sandler Alan B. , Coffin Denise , McCoy Candice , Schott Astrid , Scholz Catherine , Eckhardt S. Gail
Published: June 2008

Purpose: To evaluate the toxicity profile, pharmacologic, and biological properties of 3-pyridylmethyl N-{4-[(2-aminophenyl)carbamoyl]benzyl}carbamate (MS-275), a histone deacetylase inhibitor, when administered orally on three different dosing schedules.

Experimental Design: Patients with advanced solid malignancies and lymphomas were treated on three dose schedules: once every other week, twice weekly for 3 weeks every 28 days, and once weekly for 3 weeks every 28 days. First-cycle plasma pharmacokinetics and peripheral blood mononuclear cell histone acetylation were determined.

Results: Twenty-seven patients received ≥149 courses of treatment. Hypophosphatemia and asthenia were dose limiting on the weekly and twice-weekly dosing schedules; there was no dose-limiting toxicity on the every other week schedule. Pharmacokinetic variables revealed dose-dependent and dose-proportional increases. Two of 27 patients showed partial remissions, including one patient with metastatic melanoma who had a partial response and has remained on study for >5 years. Six patients showed prolonged disease stabilization. Levels of histone H3 and H4 acetylation in peripheral blood mononuclear cells increased qualitatively but with a high degree of interpatient variation.

Conclusions: MS-275 is well tolerated at doses up to 6 mg/m2 every other week or 4 mg/m2 weekly for 3 weeks followed by 1 week of rest and results in biologically relevant plasma concentrations and antitumor activity. Twice-weekly dosing was not tolerable due to asthenia, and further evaluation of this schedule was halted. The recommended dose for further disease-focused studies is 4 mg/m2 given weekly for 3 weeks every 28 days or 2 to 6 mg/m2 given once every other week.
A Novel CD11c Monoclonal Antibody Effective in Formalin-Fixed Tissue for the Diagnosis of Hairy Cell Leukemia
Authors: Jöhrens Korinna , Happerfield Lisa C. , Brown John P. , Erber Wendy N. , Stein Harald , Anagnostopoulos Ioannis
Published: June 2008

Objective: The diagnosis of hairy cell leukemia (HCL) and its distinction from other B-cell lymphomas can be difficult in formalin-fixed tissue. This is because the histology is not always classical, and despite having a characteristic phenotype, there are few relevant monoclonal antibodies with sufficient sensitivity and specificity that can be applied to fixed material. In this study, we assessed the utility of a newly developed antibody against a formalin-resistant CD11c epitope (5D11) for the diagnosis and monitoring of HCL in formalin-fixed tissue. Methods: We performed immunohistochemical staining for CD11c expression in formalin-fixed and also decalcified tissue of 196 small B-cell lymphomas, including 104 cases of HCL showing extensive to minimal infiltrates. Results: The CD11c antibody was both sensitive and specific for HCL, even in cases with minimal infiltration. Conclusion: We recommend that this CD11c antibody be added to a panel of antibodies for immunostaining of formalin-fixed material, for differentiation of HCL from other small B-cell lymphomas, and for detection of residual disease following therapy.