bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of cortical astrocyte differentiation by Hes6 requires amino‐ and carboxy‐terminal motifs important for dimerization and phosphorylation
Authors: Belanger‐Jasmin Stephanie , Llamosas Estelle , Tang Yeman , Joachim Kerline , Osiceanu Ana‐Maria , Jhas Sumit , Stifani Stefano
Published: September 2007

Hairy/Enhancer of split (Hes) 6 is a basic helix‐loop‐helix protein that interacts with the transcriptional co‐repressor, Groucho, and antagonizes the neural functions of the Notch pathway. More specifically, mouse Hes6 regulates cerebral corticogenesis by promoting neurogenesis and suppressing astrocyte differentiation. The molecular mechanisms underlying the anti‐astrogenic function of Hes6 are poorly defined. Here we describe studies aimed at testing whether Hes6 inhibits astrocyte differentiation by antagonizing the transcription repression activity of Notch‐activated Hes family members like Hes1. It is reported that Hes6 preferentially forms homodimers. Heterodimerization with Hes1 is antagonized in part by a conserved N‐terminal patch of negatively charged residues. Mutation of this motif enhances heterodimerization with Hes1 and increases Hes6 ability to antagonize Hes1‐mediated transcriptional repression. However, this mutation does not increase, but instead decreases, the anti‐astrogenic activity of Hes6. It is shown further that Hes6 harbors a second conserved sequence, a C‐terminal SPXXSP motif. This sequence is phosphorylated by the mitogen activated protein kinase pathway and its mutation disrupts the anti‐astrogenic activity of Hes6 without affecting its ability to suppress Hes1. Together, these observations suggest that Hes6 homodimers regulate astrocyte differentiation through mechanisms that depend on the phosphorylation of Hes6 C‐terminal domain but are independent of its ability to suppress Hes1‐mediated transcriptional repression.
Cell‐type specific induction of tryptophan hydroxylase‐2 transcription by calcium mobilization
Authors: Lenicov Federico Remes , Lemonde Sylvie , Czesak Margaret , Mosher Tera M. , Albert Paul R.
Published: September 2007

Alterations in brain serotonin levels are implicated in major depression and are regulated by tryptophan hydroxylase‐2 (TPH2). To study its regulation, we measured TPH2 RNA by quantitative RT‐PCR in differentiated serotonergic rat raphe RN46A and GH4C1 pituitary cells, which express TPH2. Upon calcium mobilization using KCl (40 mmol/L), TPH2 RNA was rapidly (1 h) and strongly (> 10‐fold) induced in differentiated RN46A cells, but not in GH4C1 cells. This effect was blocked by actinomycin D, implicating transcriptional activation. Similarly, calcium ionophore ionomycin induced TPH2 RNA by threefold in RN46A cells. To address the promoter sites involved, the transcription start site was identified and a series of TATA‐containing TPH2 promoter‐luciferase constructs were analyzed. In differentiated RN46A cells, the TPH2 promoter was induced 2.5‐fold by ionomycin, similar to its action on TPH2 RNA. By contrast, ionomycin had no effect on TPH2 promoter activity in GH4C1 cells or TPH2‐negative L6 myoblasts. Ionomycin sensitivity was localized to within 88 bp of the start site, containing putative CCATT‐enhancer binding protein element, activator protein‐1 and ‐2 (AP‐1, AP‐2) elements. These results are the first to identify calcium‐mediated regulation of the proximal TPH2 promoter as critical for cell‐specific TPH2 expression.
Chronic exposure to sub‐lethal beta‐amyloid (Aβ) inhibits the import of nuclear‐encoded proteins to mitochondria in differentiated PC12 cells*
Authors: Sirk Daniel , Zhu Ziping , Wadia Jehangir S. , Shulyakova Natalya , Phan Nam , Fong Jamie , Mills Linda R.
Published: September 2007

Studies on amyloid beta (Aβ|), the peptide thought to play a crucial role in the pathogenesis of Alzheimer’s disease, have implicated mitochondria in Aβ‐mediated neurotoxicity. We used differentiated PC12 cells stably transfected with an inducible green fluorescent protein (GFP) fusion protein containing an N′‐terminal mitochondrial targeting sequence (mtGFP), to examine the effects of sub‐lethal Aβ on the import of nuclear‐encoded proteins to mitochondria. Exposure to sub‐lethal Aβ25–35 (10 μmol/L) for 48 h inhibited mtGFP import to mitochondria; average rates decreased by 20 ± 4%. Concomitant with the decline in mtGFP, cytoplasmic mtGFP increased significantly while mtGFP expression and intramitochondrial mtGFP turnover were unchanged. Sub‐lethal Aβ1–42 inhibited mtGFP import and increased cytoplasmic mtGFP but only after 96 h. The import of two endogenous nuclear‐encoded mitochondrial proteins, mortalin/mtHsp70 and Tom20 also declined. Prior to the decline in import, mitochondrial membrane potential (mmp), and reactive oxygen species levels were unchanged in Aβ‐treated cells versus reverse phase controls. Sustained periods of decreased import were associated with decreased mmp, increased reactive oxygen species, increased vulnerability to oxygen‐glucose deprivation and altered mitochondrial morphology. These findings suggest that an Aβ‐mediated inhibition of mitochondrial protein import, and the consequent mitochondrial impairment, may contribute to Alzheimer’s disease.
Timing of potential and metabolic brain energy
Authors: Korf Jakob , Gramsbergen Jan Bert
Published: September 2007

The temporal relationship between cerebral electro‐physiological activities, higher brain functions and brain energy metabolism is reviewed. The duration of action potentials and transmission through glutamate and GABA are most often less than 5 ms. Subjects may perform complex psycho‐physiological tasks within 50 to 200 ms, and perception of conscious experience requires 0.5 to 2 s. Activation of cerebral oxygen consumption starts after at least 100 ms and increases of local blood flow become maximal after about 1 s. Current imaging technologies are unable to detect rapid physiological brain functions. We introduce the concepts of potential and metabolic brain energy to distinguish trans‐membrane gradients of ions or neurotransmitters and the capacity to generate energy from intra‐ or extra‐cerebral substrates, respectively. Higher brain functions, such as memory retrieval, speaking, consciousness and self‐consciousness are so fast that their execution depends primarily on fast neurotransmission (in the millisecond range) and action‐potentials. In other words: brain functioning requires primarily maximal potential energy. Metabolic brain energy is necessary to restore and maintain the potential energy.
Increased expression of lysosomal acid phosphatase in CLN3‐defective cells and mouse brain tissue
Authors: Pohl Sandra , Mitchison Hannah M. , Kohlschütter Alfried , Diggelen Otto van , Braulke Thomas , Storch Stephan
Published: September 2007

Juvenile neuronal ceroid lipofuscinosis (Batten disease) is a neurodegenerative disorder caused by defective function of the lysosomal membrane glycoprotein CLN3. The activity of the lysosomal acid phosphatase (LAP/ACP2) was found to be significantly increased in the cerebellum and brain stem of Cln3‐targeted mice during the early stages of postnatal life. Histochemical localization studies revealed an increased LAP/ACP2 staining intensity in neurons of the cerebral cortex of 48‐week‐old Cln3‐targeted mice as compared with controls. Additionally, the expression of another lysosomal membrane protein LAMP‐2 was increased in all brain areas. Knockdown of CLN3 expression in HeLa cells by RNA interference also resulted in increased LAP/ACP2 and LAMP‐2 expression. Finally in fibroblasts of two juvenile neuronal ceroid lipofuscinosis patients elevated levels of LAP/ACP2 were found. Both activation of gene transcription and increased protein half‐life appear to contribute to increased LAP/ACP2 protein expression in CLN3‐deficient cells. The data suggest that lysosomal dysfunction and accumulation of storage material require increased biogenesis of LAP/ACP2 and LAMP‐2 positive membranes which makes LAP/ACP2 suitable as biomarker of Batten disease.
PERMANENT GENETIC RESOURCES: Identification of nuclear microsatellite loci for Ipomopsis aggregata and the distribution of pairwise relatedness in a natural population
Authors: STEARNS FRANK , BOLES SANDRA , HURSTON HEATHER , VO TANYA , BUTLER DALE , SHUHAM WALTER , JUENGER THOMAS E.
Published: September 2007

Nine microsatellite loci were developed from enriched libraries of scarlet gilia (Ipomopsis aggregata). A screen of 160 individuals from a population identified reduced levels of heterozygosity, low levels of relatedness, and weak spatial genetic patterns. The population inbreeding coefficient was calculated to be 0.19 (SE = 0.04). These patterns are consistent with those expected from low levels of biparental inbreeding in an obligate outcrosser and extensive seed and pollen dispersal. These preliminary data confirm the usefulness of microsatellite markers for breeding system studies of I. aggregata.
STARFISH DIVERSITY IN THE WENLOCK OF ENGLAND
Authors: HERRINGSHAW LIAM G. , THOMAS ALAN T. , SMITH M. PAUL
Published: September 2007

Abstract:  Although their record extends back to the Early Ordovician, the occurrence of fossil starfish (Echinodermata: Asteroidea) is dependent almost exclusively upon horizons of exceptional preservation. Thus, asteroids found in Silurian obrution deposits of the English Midlands and Welsh Borderlands are particularly significant to an understanding of the early diversity of the group. Six species are described here: Hudsonaster? carectum sp. nov. (Hudsonasteridae), from the lower part of the Lower Elton Formation; and, from the Much Wenlock Limestone Formation, the hudsonasterids Doliaster brachyactis gen. et sp. nov. and Siluraster? ketleyi (Spencer, 1916), the lepidasterids Lepidaster grayi Forbes, 1850 and Lepidactis wenlocki Spencer, 1918, and the palasterinid Palasterina orchilocalia sp. nov. Though few in number, they show a diverse range of body morphologies when compared with Ordovician taxa: L. wenlocki had long, slender rays when fully grown whereas D. brachyactis is the first asteroid with the short‐rayed body form of extant cushion stars. Most distinctive of all is L. grayi, the earliest multiradiate taxon known, all complete specimens of which have 13 rays. This morphological variety is interpreted as indicating that by the Early Silurian starfish were exploiting a wide range of feeding habits and ecological niches.
REVISION OF THE TYPE MATERIAL AND NOMENCLATURE OFMASTODONSAURUS GIGANTEUS(JAEGER) (TEMNOSPONDYLI) FROM THE MIDDLE TRIASSIC OF GERMANY
Authors: MOSER MARKUS , SCHOCH RAINER
Published: September 2007

Abstract: The type material ofMastodonsaurusis revised and its complicated taxonomic history resolved. The genus was erected by Jaeger in 1828 without a species name, which was added subsequently by Holl (1829) who named the type speciesMastodonsaurus jaegeri.The large tooth on which Jaeger based hisMastodonsaurusis chosen herein as lectotype of the type species. A smaller second individual, represented by a piece of an occiput, was also named by Jaeger in 1828 asSalamandroides giganteusand, owing to the find of a complete skull, was recognized in 1833 by the same author as belonging to the same species as theMastodonsaurus. Therefore,Mastodonsaurus giganteus(Jaeger, 1828) is a senior subjective synonym of the type speciesM. jaegeriHoll, 1829. The precedence of the two generic names was chosen in 1834 by the first reviser, von Alberti, in favour ofSalamandroides, but all later authors, including von Alberti himself, followed Jaeger, who decided in 1837 to retain the nameMastodonsaurus. The established usage ofMastodonsaurusis preserved formally herein (nomen protectum). The namesBatrachosaurusFitzinger, 1837, andLabyrinthodonOwen, 1841 are unjustified replacement names ofMastodonsaurus. The namesM. jaegerivon Meyer, 1832,S. jaegerivon Alberti, 1834 andM. salamandroidesJaeger, 1837 are junior homonyms and synonyms ofM. jaegeriHoll, 1829, andM. giganteus(Jaeger, 1828), respectively. A recent attempt to replace the universally used Capitosauroidea Watson, 1919 by the unused and newly elevated Mastodonsauroidea Lydekker, 1885 is rejected. Two older synonyms of Mastodonsauridae Lydekker, 1885 (nomen protectum) are rejected as unavailable (Labyrinthodontidae vonMeyer, 1842) andnomen oblitum(Batrachosauridae Fitzinger, 1843), respectively. The holotype ofMastodonsaurus giganteusis reinstated and valid on the basis of three diagnostic features present: the tripartite posterior rim of the parasphenoid, a laterally pushed suture between the parasphenoid and basipterygoid, and a wide slit‐like eustachian tube opening.Mastodonsaurusis known from specimens representing a continuous growth series, now also encompassing the lectotype ofMastodonsaurus jaegeri, which until rather recently stood isolated from other specimens as the largest find by far.
Gastric Stasis Occurs in Spontaneous, Visually Induced, and Interictal Migraine
Authors: Aurora Sheena , Kori Shashidhar , Barrodale Patricia , Nelsen Andrew , McDonald Susan
Published: September 2007

Objective.— To evaluate and compare gastric motility and emptying during spontaneous migraine to previous observations from induced migraine.

Blackground.— We have previously demonstrated a delay in gastric emptying both during the interictal period and during an induced migraine. A limitation noted in these studies was whether there are differences gastrointestinally during a visually induced migraine compared to spontaneous migraines. To address this, 9 additional studies have been performed to ascertain if there is a similar delay during spontaneous migraine

Methods.— Gastric scintigraphy using a standard meal was performed in 3 subjects during 3 periods: spontaneous migraine, induced migraine, and interictal period.

Results.— On average, the time to half emptying was delayed during spontaneous migraine (124 minutes), during induced migraine (182 minutes), and during the interictal period migraine (243 minutes) compared to normative values established at our center (112 minutes). On average, similar gastric slowing was seen in all 3 groups when the percentage of nuclear material remaining in the stomach at 2 hours was measured.

Conclusions.— This study provides additional evidence of gastric stasis in migraineurs interictally during induced and spontaneous migraine.
Densification, Sintering Reactions, and Properties of Titanium Diboride With Titanium Disilicide as a Sintering Aid
Authors: Raju G. Brahma , Basu Bikramjit
Published: September 2007

In the present investigation, we explore the feasibility of using TiSi2 as a sintering aid to densify titanium diboride (TiB2) at a lower sintering temperature (<1700°C). The hot‐pressing experiments were conducted in the temperature range of 1400°–1650°C for 1 h in an argon atmosphere and TiSi2 addition to TiB2 was restricted up to 10 wt%, with an overall objective to densify the materials with a fine microstructure as well as to assess the feasibility of enhancing the mechanical and electrical properties. When all the materials were hot pressed at 1650°C, the hot‐pressed TiB2–X% TiSi2 (X=0, 2.5, 5, 10 wt%) composites were found to be densified to more than 98%ρth (theoretical density), except monolithic TiB2 (∼94%ρth). An interesting observation is the formation of a Ti5Si3 phase and this phase formation is described by thermodynamically feasible sintering reactions. Our experimental results suggest that the optimal TiB2–5 wt% TiSi2 composite can exhibit an excellent combination of properties, including a high hardness of 25 GPa, an elastic modulus of 518 GPa, an indentation toughness of ∼6 MPa·m1/2, a four‐point flexural strength of more than 400 MPa, and an electrical resistivity of 10 μΩ·cm.
Thermodynamic Studies on the AlN Sintering Powders Treated With Phosphate Species
Authors: Olhero Susana Maria , Jensen Morten Sundheim , Einarsud Mari‐Ann , Grande Tor , Ferreira José Maria Fonte
Published: September 2007

The processing of aluminum nitride (AlN) ceramics in aqueous media requires the use of a surface layer to protect the surface of the particles against hydrolysis. This surface layer might influence the densification, affecting the reactions between AlN and sintering additives. The present paper describes a thermodynamic and experimental approach to evaluate the effects of a phosphate‐based protecting surface layer on the densification of AlN in the presence of YF3–CaF2 as sintering aids, and to predict the densification behavior during sintering using thermodynamic assessments. Based on thermodynamic calculations and the measured weight loss of the samples during heating to sintering temperature, the chemical reactions occurring during firing were proposed. The proposed reactions were related to the experimental results as well as the final properties of the AlN samples, namely, thermal conductivity, microstructure, secondary phases, and density.
Rapid Synthesis of Ferromagnetic La1−xNaxMnO3 (0.00≤x≤0.25) by the Solution Combustion Method
Authors: Shivakumara Chikkadasappa , Bellakki Manjunath B. , Prakash Annigere S. , Vasanthacharya Nagsampagi Y.
Published: September 2007

Rapid synthesis of sodium‐substituted lanthanum manganite phases is reported by the solution combustion method using oxalyl dihydrazide (ODH), as fuel. As‐synthesized compounds are amorphous in nature; crystallinity was observed on heating at 800°C for 5 min. Structural parameters were determined by the Rietveld refinement method using powder X‐ray diffraction data. Parent LaMnO3 compound crystallizes in the orthorhombic structure (space group Pbnm No. 62). Sodium‐substituted compounds crystallize with rhombohedral symmetry (space group R‐3c, No.167). On increasing the sodium content, unit cell volume decreases and Mn–O–Mn bond angle increases. The fourier transform infrared spectrum shows two absorption bands around 600 and 400 cm−1 for the compositions x=0.0, 0.05, and 0.10. Mn3+/Mn4+ ratio was determined by iodometric titration. Electrical resistivity measurements reveal a composition‐controlled metal to insulator transition (TM–I), the maximum TM–I was observed for the composition La0.85Na0.15MnO3 at 285 K. Increase in magnetic moment is observed with increase in crystallite size. Room temperature vibrating sample magnetometer data indicate that for the composition up to x=0.10, the compounds are paramagnetic whereas composition with x=0.15, 0.20, and 0.25 show magnetic moments 34, 39, and 33 emu/g, respectively.
Photoluminescence from Boron‐Doped Titanium Nitride Nanocomposite Thin Films Prepared by the Magnetron Sputtering Method
Authors: Lu Sheng‐Guo , Lu Yong‐Hao , Xu Zheng‐Kui , Cheah Kwok‐Wai
Published: September 2007

Boron‐doped titanium nitride (TiBN) thin films with nanosized grains were prepared by a magnetron sputtering method. X‐ray diffraction and transmission electron microscopy observation indicated that TiBN thin films have a cubic structure with grains ∼5 nm in size. The photoluminescence (PL) of the films was investigated as a function of temperature over a wavelength range of 350–900 nm. Two PL peaks near 3.20 and 2.38 eV were conisdered to have resulted from the recombination of the donor‐bound excitons and deep‐trap defects with the holes in the valence band, respectively. An energy transfer from bound electrons to deep‐trap defects was observed in the nanocomposite thin film.
Lingual Retention and the Elimination of the Visible Clasp Arm
Authors: BRUDVIK JAMES S. , PALACIOS ROSARIO
Published: September 2007

The modern removable partial denture (RPD), in response to the increased esthetic demands of our patients, is no longer acceptable if it requires visible buccal and facial clasp arms for retention. By eliminating the bracing arm and having its functions taken by paralleled guide planes and precise, positive rests, the retentive element, a lingual circumferential wire clasp arm, will provide the same amount of retentive force as if it were placed on the buccal surface and will not be visible. Designs for the major connector either plate the lingual surface of the abutment or, as in a lingual bar, leave that surface open. Both of these situations are adaptable to the lingual retentive clasp and are illustrated in this article.

CLINICAL SIGNIFICANCE

Design features such as metal clasps needed for the retention of RPDs can be very unsightly, creating an esthetic problem. This article reviews the concepts for creating lingual clasp arms that enhance the esthetic quality of prostheses.

(J Esthet Restor Dent 19:247–255, 2007)
Inheritance tax – an equitable tax no longer: time for abolition?
Authors: Lee Natalie
Published: September 2007

Statistics from HM Revenue & Customs predict that receipts from inheritance tax will amount to some £3.56 billion in the tax year 2006/07. This compares to £1.68 billion in 1997/98. This paper explores the reason for the large increase in inheritance tax revenues and, in the light of those findings, together with a consideration of the recent public reaction to the changes to the inheritance taxation of trusts announced in the Budget 2006 and incorporated in the Finance Act 2006, argues that, whereas the justification for a tax on the value of property in a person’s estate on death (or within a certain number of years before death) was rooted in equity, equity now forms the argument for its abolition or, at least, its substantial reform.
Prolonged imatinib‐induced myelosuppression in chronic myeloid leukaemia with an unusually long survival
Authors: Busuttil D. P.
Published: September 2007

A case of Philadelphia chromosome positive chronic myeloid leukaemia (CML) with the longest survival ever reported in the medical literature is presented. The duration of the chronic phase was 29 years, the overall survival being 31 years. The clinical course, when challenged with imatinib in the later stages of the disease, was at variance with what is to be expected from the experience in similar situations. Lifelong myelosuppression resulted that interfered with further therapy and contributed to the demise of the patient from sepsis three years later. Caution is suggested with the use of imatinib in fibrotic CML with a low platelet count.
Pulsatile Blood Flow and Gas Exchange Across a Cylindrical Fiber Array
Authors: Chan Kit Yan , Fujioka Hideki , Hirshl Ronald B. , Bartlett Robert H. , Grotberg James B.
Published: September 2007

The pulsatile blood flow and gas transport of oxygen and carbon dioxide through a cylindrical array of microfibers are numerically simulated. Blood is modeled as a homogeneous Casson fluid, and hemoglobin molecules in blood are assumed to be in local equilibrium with oxygen and carbon dioxide. It is shown that flow pulsatility enhances gas transport and the amount of gas exchange is sensitive to the blood flow field across the fibers. The steady Sherwood number dependence on Reynolds number was shown to have a linear relation consistent with experimental findings. For most cases, an enhancement in gas transport is accompanied with an increase in flow resistance. Maximum local shear stress is provided as a possible indicator of thrombosis, and the computed shear stress is shown to be below the threshold value for thrombosis formation for all cases evaluated.
Response to Comments on "The Consensus Coding Sequences of Human Breast and Colorectal Cancers"
Authors: Parmigiani Giovanni , Lin Jimmy , Boca Simina M. , Sjöblom Tobias , Jones Siân , Wood Laura D. , Parsons D. Williams , Barber Thomas , Buckhaults Phillip , Markowitz Sanford D. , Park Ben Ho , Bachman Kurtis E. , Papadopoulos Nickolas , Vogelstein Bert , Kinzler Kenneth W. , Velculescu Victor E.
Published: September 2007

Forrest and Cavet, Getz
et al
., and Rubin and Green describe a variety of statistical methods to analyze the mutational data published in Sjöblom
et al
. However, their conclusions are inaccurate because they are based on analyses that do not fully take into account the experimental design and other critical features of our study. When these factors are incorporated, their methods provide estimates similar to those we reported and support the conclusion that a large number of genes are mutated at rates greater than the passenger mutation rate.
TLR3 Deficiency in Patients with Herpes Simplex Encephalitis
Authors: Zhang Shen-Ying , Jouanguy Emmanuelle , Ugolini Sophie , Smahi Asma , Elain Gaëlle , Romero Pedro , Segal David , Sancho-Shimizu Vanessa , Lorenzo Lazaro , Puel Anne , Picard Capucine , Chapgier Ariane , Plancoulaine Sabine , Titeux Matthias , Cognet Céline , von Bernuth Horst , Ku Cheng-Lung , Casrouge Armanda , Zhang Xin-Xin , Barreiro Luis , Leonard Joshua , Hamilton Claire , Lebon Pierre , Héron Bénédicte , Vallée Louis , Quintana-Murci Lluis , Hovnanian Alain , Rozenberg Flore , Vivier Eric , Geissmann Frédéric , Tardieu Marc , Abel Laurent , Casanova Jean-Laurent
Published: September 2007

Some Toll and Toll-like receptors (TLRs) provide immunity to experimental infections in animal models, but their contribution to host defense in natural ecosystems is unknown. We report a dominant-negative TLR3 allele in otherwise healthy children with herpes simplex virus 1 (HSV-1) encephalitis. TLR3 is expressed in the central nervous system (CNS), where it is required to control HSV-1, which spreads from the epithelium to the CNS via cranial nerves. TLR3 is also expressed in epithelial and dendritic cells, which apparently use TLR3-independent pathways to prevent further dissemination of HSV-1 and to provide resistance to other pathogens in TLR3-deficient patients. Human TLR3 appears to be redundant in host defense to most microbes but is vital for natural immunity to HSV-1 in the CNS, which suggests that neurotropic viruses have contributed to the evolutionary maintenance of TLR3.
Phase-Coherent Transport in Graphene Quantum Billiards
Authors: Miao F. , Wijeratne S. , Zhang Y. , Coskun U. C. , Bao W. , Lau C. N.
Published: September 2007

As an emergent electronic material and model system for condensed-matter physics, graphene and its electrical transport properties have become a subject of intense focus. By performing low-temperature transport spectroscopy on single-layer and bilayer graphene, we observe ballistic propagation and quantum interference of multiply reflected waves of charges from normal electrodes and multiple Andreev reflections from superconducting electrodes, thereby realizing quantum billiards in which scattering only occurs at the boundaries. In contrast to the conductivity of conventional two-dimensional materials, graphene's conductivity at the Dirac point is geometry-dependent because of conduction via evanescent modes, approaching the theoretical value 4e
2
/πh (where e is the electron charge and h is Planck's constant) only for short and wide devices. These distinctive transport properties have important implications for understanding chaotic quantum systems and implementing nanoelectronic devices, such as ballistic transistors.
Anti-Inflammatory Activity of Human IgG4 Antibodies by Dynamic Fab Arm Exchange
Authors: van der Neut Kolfschoten Marijn , Schuurman Janine , Losen Mario , Bleeker Wim K. , Martínez-Martínez Pilar , Vermeulen Ellen , den Bleker Tamara H. , Wiegman Luus , Vink Tom , Aarden Lucien A. , De Baets Marc H. , van de Winkel Jan G.J. , Aalberse Rob C. , Parren Paul W. H. I.
Published: September 2007

Antibodies play a central role in immunity by forming an interface with the innate immune system and, typically, mediate proinflammatory activity. We describe a novel posttranslational modification that leads to anti-inflammatory activity of antibodies of immunoglobulin G, isotype 4 (IgG4). IgG4 antibodies are dynamic molecules that exchange Fab arms by swapping a heavy chain and attached light chain (half-molecule) with a heavy-light chain pair from another molecule, which results in bispecific antibodies. Mutagenesis studies revealed that the third constant domain is critical for this activity. The impact of IgG4 Fab arm exchange was confirmed in vivo in a rhesus monkey model with experimental autoimmune myasthenia gravis. IgG4 Fab arm exchange is suggested to be an important biological mechanism that provides the basis for the anti-inflammatory activity attributed to IgG4 antibodies.
Lighting the Universe with Filaments
Authors: Gao Liang , Theuns Tom
Published: September 2007

The first stars in the universe form when chemically pristine gas heats as it falls into dark-matter potential wells, cools radiatively because of the formation of molecular hydrogen, and becomes self-gravitating. Using supercomputer simulations, we demonstrated that the stars' properties depend critically on the currently unknown nature of the dark matter. If the dark-matter particles have intrinsic velocities that wipe out small-scale structure, then the first stars form in filaments with lengths on the order of the free-streaming scale, which can be ∼10
20
meters (∼3 kiloparsecs, corresponding to a baryonic mass of ∼10
7
solar masses) for realistic “warm dark matter” candidates. Fragmentation of the filaments forms stars with a range of masses, which may explain the observed peculiar element abundance pattern of extremely metal-poor stars, whereas coalescence of fragments and stars during the filament's ultimate collapse may seed the supermassive black holes that lurk in the centers of most massive galaxies.
Structure of C8α-MACPF Reveals Mechanism of Membrane Attack in Complement Immune Defense
Authors: Hadders Michael A. , Beringer Dennis X. , Gros Piet
Published: September 2007

Membrane attack is important for mammalian immune defense against invading microorganisms and infected host cells. Proteins of the complement membrane attack complex (MAC) and the protein perforin share a common MACPF domain that is responsible for membrane insertion and pore formation. We determined the crystal structure of the MACPF domain of complement component C8α at 2.5 angstrom resolution and show that it is structurally homologous to the bacterial, pore-forming, cholesterol-dependent cytolysins. The structure displays two regions that (in the bacterial cytolysins) refold into transmembrane β hairpins, forming the lining of a barrel pore. Local hydrophobicity explains why C8α is the first complement protein to insert into the membrane. The size of the MACPF domain is consistent with known C9 pore sizes. These data imply that these mammalian and bacterial cytolytic proteins share a common mechanism of membrane insertion.
COMPOSITE ALGORITHMS IN IMAGE CONTENT SEARCHES
Authors: PARKER J. R. , BEHM BRAD
Published: September 2007

A combination of three algorithms is proposed that gives a reasonable rate of success in image similarity searches. All use region based statistical measures using a combination of color features, linear features, and intensities combined with a collection of methods for subdividing the image into regions. All possible combinations were evaluated and the best (highest success rate) was selected to be used as a practical image similarity measure. Component algorithms are combined using a simple decision fusion voting scheme, giving success rates in the range of 50–60%. For a web search application this is quite reasonable.
SHEAR VISCOSITY OF YANG–MILLS THEORY IN THE CONFINEMENT PHASE
Authors: BREVIK IVER , GHOROKU KAZUO
Published: September 2007

In terms of a simple holographic model, we study the absorption cross-section and the shear viscosity of a pure Yang–Mills field at low temperature where the system is in the confinement phase. Then we expect that the glueball states are the dominant modes in this phase. In our holographic model, an infrared cut-off rm is introduced as a parameter which fixes the lowest mass of the glueball. As a result, the critical temperature of gluon confinement is estimated to be Tc ~ 127 MeV . For T < Tc, we find that both the absorption cross-section and the shear viscosity are independent of the temperature. Their values are frozen at the values corresponding to the critical point, for 0 < T < Tc. We discuss this behavior by considering the glueball mass and its temperature dependence.
Epidemiology of Myopia
Authors: Saw Seang-Mei
Published: September 2007

The article is about the prevalence rates of myopia in Asian cities like Singapore.
New Solid State Refractive Laser
Authors: Constable Ian
Published: September 2007

The short article is about new solid state refractive laser.
Retinal Disorders in Asia-Pacific
Authors: Foulds Wallace S.
Published: September 2007

The article is about retinal diseases in the Asia Pacific region. It discusses about genetically determined retinal disorders such as retinitis pigmentosa, diabetic disease and myopia.
Laboratory Science Suggests New Approach to Diabetic Retinopathy
Authors: Constable Ian
Published: September 2007

This short article is on new approaches to diabetic retinopathy.
DCB's BioFronts Program
Authors: Lin Michelle M. S.
Published: September 2007

The article is about the development center for biotechnology, a non profit biotech research and development organization of about 300 employees.
Biotechnology at National Taiwan University
Authors: Chen Yih-ming
Published: September 2007

The article is about the current research in National Taiwan University and the center for biotechnology.
Rice Genomics and the Future of Publicly Funded Rice Research
Authors: Cantrell Ronald P.
Published: September 2007

The article is about the sequencing of the rice genome, benefits of biotechnology, beyond rice breeding, financial constraint, the cooperation with private sector, public-privatization act, International Functional Genomics Working Group and the training of the scientists.
Rice Functional Genomics by T-DNA Insertional Mutagenesis
Authors: An Gynheung
Published: September 2007

The article is about the rice functional genomics. There are details on the generation of T-DNA insertional mutant lines in rice, insertional lines for the isolation of mutants, how T-DNA vector can be used for entrapping tissue-specific genes and promoters, and the generation of database for T-DNA flanking sequences.
Rice Functional Genomics by Transposon Mutagenesis
Authors: Han Chang-deok
Published: September 2007

Transposable elements are powerful mutagens. Along with genomic sequences, knock-out phenotypes and expression patterns are important information to elucidate the function of genes. In this review, I propose a strategy to develop tranposant lines on a large scale by combining genetic cross and tissue culture of Ac and Ds lines. Based on the facts that Ds tends to be inactive in F2 or later generation and Ds becomes reactivated via tissue culture, a large scale of transposants can be produced by tissue culture of seeds carrying Ac and inactive Ds. In this review, I describe limitations and considerations in operating transposon tagging systems in rice. Also, I discuss the efficiency of our gene trap system and technical procedures to clone Ds flanking DNA.
Bioinfomatics in Singapore
Authors: Wong Limsoon
Published: September 2007

Singapore seeks to be an international center for the biomedical sciences and its related industries. Bioinformatics is seen as an important ingredient in this ambition. We provide in this short report a brief overview of bioinformatics in Singapore. We cover aspects such as training (Section 3), research (Section 4), and commercialization (Section 5). We also introduce some of the main centers of activities, as well as some of the bioinformaticists in these centers.
Ethnic Populations and the New Paradigm for Dissection of a Complex Disease
Authors: Majumder Partha P.
Published: September 2007

The article is about the study of the various ethnic groups resident in India that will provide insight on human evolutions and the evolution and spread of diseases.
A Survey on Knowledge, Attitudes and Usage of Complementary and Alternative Medicine in Singapore
Authors: Koh Hwee-Ling , Ng Hui-Ling , Teo Hsiao-Huei
Published: September 2007

The article is on a survey of knowledge, attitudes and the usage of complementary and alternative medicine in Singapore. It explains the methods, the results and the conclusion of the experiment.
WHY ARE MORE PEOPLE TURNING TOWARDS KAMPO MEDICINE?
Authors: Ushiroyama Takahisa
Published: September 2007

This article is about the concepts of modern western medicine and Kampo Medicines and the adequate combination of both medical approaches in practical medical care.
Ayurveda — For Optimal Health and Well-Being
Authors: Douillard John
Published: September 2007

The article is about how ayurveda is a unique system of medicine, It touches on how ayurveda is important in the prevention of diseases. It also talks about ayurvedic treatments.
Herbal Medicines for Diabetes and Cancer — A Global Perspective
Authors: Pushparaj Peter Natesan
Published: September 2007

This articles discusses how herbal medicine is used for diabetes and cancer.
The Use and Misuse of Ephedra
Authors: Motoo Yoshiharu
Published: September 2007

The article is about the use and misuse of Ephedra.
Alternative Medicine
Authors: Hong Yan , Guo Baolin
Published: September 2007

Utility of DNA Profiling in Quality Control of Medicinal Herbs.
Commentaries & Analyses — Recent Developments in the Biotech Industry in Asia Pacific
Authors: Bourinbaiar Aldar S.
Published: September 2007

The BIO 2005 international convention is the largest gathering of the biotech industry in the world. Last year, it was held on June 19-22 inside the behemoth Convention Center in downtown Philadelphia. It brought together 18 730 executives, investors, consultants, lawyers, politicians and scientists from 56 countries. More than 500 media representatives covered the event. Biotechnology research and findings presented by countries in the Asia Pacific region has begun to make a significant impact on these annual BIO gatherings. The achievements of some countries in this region are briefly reviewed.
The Buzz in Singapore's Biotech industry
Authors: Chan Yiu Lin
Published: September 2007

This article is about the buzz and the growth of Singapore's life science industry.
QUALITY IN CLINICAL TRIALS
Authors: Suresh Shirley
Published: September 2007

This articles is about the Product or Service in the Quality in Clinical Trials.
Clinical Trials in Australia
Authors: Nelson Lisa
Published: September 2007

This article is an overview of high quality and relatively low destination for Clinical Trials in Australia.
Special Feature — Lipidomics – New Frontiers in Lipid Research
Authors: Wenk Markus R.
Published: September 2007

It is clear that some of the greatest intellectual challenges of the 21st century will center around biological sciences and medicine. Lipidomics is a new 'omics.' Although this name was coined only recently, the importance of the systems biology of lipids is now widely recognized.
Biomedical IT Core Laboratory, Taiwan's National Genotyping Center
Authors: Yao Adam , Wang Elin , Tsai Ming-Fang , Chen Yan-Hau
Published: September 2007

This article deals about the IT infrastructure that supports major clinical projects on genetics in the institute of Taiwan.
Fighting Diseases with IT
Authors: Ng See-Kiong , Choo Justin
Published: September 2007

This article reveals the discovery and development of new drugs for the treatment of diseases aided with IT.
OUT-OF-PLANE FREE VIBRATIONS OF CIRCULAR STRIPS WITH VARIABLE BREADTH
Authors: LEE BYOUNG KOO , LEE TAE EUN , CARR ATHOL J. , OH SANG JIN
Published: September 2007

This paper deals with the out-of-plane free vibrations of circular strips with linearly varying breadth. In deriving the differential equations for such strips, the effects of the rotatory and torsional inertias and shear deformation are considered. The differential equations are numerically solved to calculate the natural frequencies and mode shapes. In the numerical examples, three end constraints, i.e. clamped–clamped, clamped-hinged and hinged–hinged ends, are considered. The five lowest frequency parameters and mode shapes are presented. The effects of the rotatory and torsional inertias, and shear parameter on the natural frequencies are evaluated. Parametric studies are carried out for the influence of following parameters of the strip on the natural frequencies: subtended angle, section ratio, thickness ratio, and slenderness ratio. Also presented are the experimental validations of the seven lowest predicted natural frequencies. The natural frequencies obtained by this study agree well with those by the finite element method for both the flexural and torsional modes.
POSTBUCKLING RESPONSE OF FUNCTIONALLY GRADED RECTANGULAR PLATES SUBJECTED TO THERMO-MECHANICAL LOADING
Authors: SHUKLA K. K. , RAVI KUMAR K. V. , PANDEY RAMESH , NATH Y.
Published: September 2007

The present work deals with the stability analysis of shear deformable functionally graded rectangular plates subjected to thermo-mechanical loads. The material properties of the functionally graded plates are assumed to vary continuously through the thickness, according to a simple power law distribution of the volume fraction of the constituents. An analytical approach based on fast converging Chebyshev polynomials is presented. The formulation is based on first-order shear deformation plate theory and von-Karman nonlinearity. The temperature-dependent thermal and mechanical properties of FGM plate are considered. The variations in the buckling load/temperature due to various parameters are studied. The postbuckling response of the clamped FGM plate, subjected to in-plane edge compressive mechanical loading (uniaxial, biaxial, shear), thermal (uniform in-plane temperature, transverse temperature gradient) and thermo-mechanical loading are presented. It is observed that volume fraction index greatly affects the buckling load/temperature of the plate.
COMPARISON OF MORPHOLOGICAL-BASED SEGMENTATION METHODS FOR FETAL FEMUR LENGTH MEASUREMENTS
Authors: RAHMATULLAH BAHBIBI , BESAR ROSLI
Published: September 2007

Measurement of fetal femur length is crucial for the estimation of fetal age and growth pattern. Due to the noisy nature of ultrasound images and the variation in image acquisition and measurement techniques, manual measurements are subject to interobserver and intraobserver variability. The motivation of this paper is to study the efficiency of automated methods used in the femur endpoint detection module of our proposed computer-assisted processing and analysis system, which is employed to determine the gestational age for promoting the standardization of fetal femur measurements, thus resulting in more reliable age estimates. The proposed methods are based on the morphological operators methods5and the morphological watershed segmentation method. We applied these methods on a set of 100 digitized fetal femur images of size 287 × 224 pixels with 256 gray-level images and a resolution of 100 pixels per inch (ppi) horizontally and vertically. The results showed that the watershed method was the more efficient one and gave reliable results for every femur image tested.
REPRESENTATIONS OF BINARY FORMS BY QUATERNARY FORMS
Authors: CHOIE Y. , CHUNG Y.
Published: September 2007

In this paper we study a family of quaternary forms which represent almost all binary forms of a certain type. The result follows from the representation number by the genus of ternary forms and a correspondence among theta series.
THE ERROR ZETA FUNCTION
Authors: HASSEN ABDUL , NGUYEN HIEU D.
Published: September 2007

This paper investigates a new special function referred to as the error zeta function. Derived as a fractional generalization of hypergeometric zeta functions, the error zeta function is shown to exhibit many properties analogous to its hypergeometric counterpart, including its intimate connection to Bernoulli numbers. These new properties are treated in detail and used to demonstrate a pre-functional equation satisfied by this special function.
A Model of early to middle Miocene Deep Ocean circulation for the Atlantic and Indian Oceans
Authors: Ramsay Anthony T. S. , Smart Christopher W. , Zachos James C.
Published: September 2007

Tethyan Outflow Water (TOW), characterized by high benthic δ
13
C values, was a component of the early Miocene deep water mass of the Atlantic (
c.
20 and
c.
13 Ma) and Indian (
c.
20 and
c.
14.5 Ma) Oceans. Fluctuations in temperature, salinity and quantity of dissolved oxygen coincided with high abundances of infaunal, smooth-walled bolivinids within the Atlantic and Indian Ocean TOW between 19.5 and 16.5 Ma.

High δO values recorded in the Atlantic water mass may have originated, in part, from evaporation and the formation of warm, saline water within the Tethys. The southward flowing Atlantic TOW at depths of 2–4.5 km enhanced meridional heat transport. It was overlain by Northern Component Water (NCW) with a lower δC signal. TOW and NCW were replaced by southward flowing North Atlantic Deep Water at
c.
13 Ma when cold dense Norwegian—Greenland Sea water flowed across the Greenland—Scotland Ridge.

Indian Ocean TOW was restricted laterally by the Chagos—Lacadive Ridge, and vertically (1.3 to 3 km) by overlying intermediate water, characterized by the occurrence of coarse-walled bolivinids, and underlying deep water characterized by high abundances (>10%) of
Nuttallides umboniferus
. The coarse-walled bolivinid and ‘
N. umboniferus
’ faunas were associated with lower temperature, salinity and higher oxygen concentrations. Tethyan outflow to the northwest Indian Ocean ended at
c.
14.5 Ma, probably in response to the closure of a gateway, and resulted in a two-component deep water mass structure. The coeval increase in the relative abundances of
N. umboniferus
at Indian Ocean Sites 237 (
c.
2 km) and 710 (
c.
3.5 km), at
c.
13 Ma, probably records the impact of this change on the nature of Indian Ocean deep water at depths between 2 and 4 km.

The termination of the Atlantic and, to a lesser extent, Indian Ocean TOW contributed to global cooling and to the expansion of the Antarctic Ice Sheet by limiting the meridional heat transport.
Lateral diapiric emplacement of Triassic evaporites at the southern margin of the Guadalquivir Basin, Spain
Authors: Berástegui X. , Banks C.J. , Puig C. , Taberner C. , Waltham D. , Fernàndez M.
Published: September 2007

The Guadalquivir Basin is the Neogene foreland basin of the central and western Betic thrust belt in southern Spain. At the boundary between the basin and the outcrops of thrust nappes of Mesozoic limestones of the Prebetic and Subbetic is a broad belt of outcrops of Triassic evaporitic sediments with scattered younger rocks: the so-called ‘Olistostrome’ unit. This is highly deformed, in places chaotic, and its mode of emplacement has been attributed by various authors to olistostromal debris flow, diapirism, or tectonic melange. Studies of outcrop data in conjunction with seismic and well data, integrated using restorable cross-sections lead us to propose the following sequence of emplacement mechanisms. (a) Loading above a Triassic evaporite formation, probably in the Intermediate Units depositional zone, by north vergent thrusting of thick nappes of Mesozoic sediments, causes northward expulsion of evaporitic sediments between a basal thrust and the base of the limestones. (b) Continued thrust loading drives the diapiric body forwards ahead of the thrust belt, into the floor of the deepening Miocene foreland basin. The body includes blocks of Triassic rocks in normal stratigraphic sequence, as well as blocks of younger rocks broken off the leading hanging-wall cutoffs of the nappes. (c) When the diapiric body reaches the sea-floor of the basin, its top becomes subject to modification by sedimentary processes such as dissolution of evaporites leaving a cap rock and debris flow, both submarine and subaerial but rarely, if ever, forming true olistostromes. (d) At the leading edge of the diapir, northward compression of Miocene basin sediments results in thin-skinned thrusting within these sediments, and formation of duplex structures with a north-dipping monoclinal deformation front. Results from analogue and numerical modelling match the main geological features observed in the study area, thus supporting the plausibility of the proposed lateral diapiric emplacement of the chaotic unit.