bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF SWEET POTATO CULTIVARS AND HEATING METHODS FOR CONTROL OF MALTOSE PRODUCTION, VISCOSITY AND SENSORY QUALITY
Authors: RIDLEY STEPHEN C. , LIM MIANG , HEENAN SAM , BREMER PHIL
Published: June 2005

Two varieties of sweet potato were subjected to four cooking temperature‐time combinations. A fifth treatment involved adding maltose syrup. Raw comminuted sweet potato mash and cooked sweet potato puree were evaluated for total solids, alcohol insoluble solids, commonly occurring sugars, viscosity (puree only) and for starch gelatinization temperatures. The uncooked Owairaka Red variety was higher in total solids and in alcohol insoluble solids than the Toka Toka Gold. With the exception of the cooked puree with added maltose, baking at 200C resulted in puree with the highest maltose levels. A very fast cooking procedure tended to result in puree with lower levels of maltose and high viscosity. Sensory studies revealed that the Owairaka Red variety produced puree with more viscous and adhesive mouth feel.  It  was  concluded  that  cooking  alone  could  not  be  used  to  optimize  both maltose production and viscosity.
FIBER CONTENT IN THE EDIBLE PORTION OF EIGHT MANDARIN ORANGES CULTIVARS
Authors: PÉREZ‐LÓPEZ A.J. , CARBONELL‐BARRACHINA A.A.
Published: June 2005

Eight commercial varieties of mandarin oranges grown in Spain (Nova, Ortanique, Satsuma, Marisol, Fortuna, Ellendale, Clementine and ecologic Clementine) were harvested in winter and analyzed for their fiber composition. The neutral detergent fiber (NDF) content, 21.32 ± 0.09%, was higher than the crude fiber (CF) content, 15.42 ± 0.10%, and the acid detergent fiber (ADF) content, 8.59 ± 0.05%. The CF contents were in the range of 14.55–16.50%, lower than previously reported, because only the edible portion was considered in this study. The relative content of CF of the eight cultivars studied was not consistent with those of the NDF and/or ADF. Clementine had the highest values of CF, but the lowest of NDF, with intermediate values of ADF. On the other hand, the cvs. Nova and Ortanique had the lowest values of CF, but the highest values of both NDF and ADF. Therefore, the most valuable mandarin orange cultivars, according to their fiber content, were traditional and ecologic Clementine, Nova and Ortanique.
EFFECTS OF USING ROSEMARY EXTRACT AND ONION JUICE ON OXIDATIVE STABILITY OF SARDINE (SARDINA PILCHARDUS) MINCE
Authors: SERDAROĞLU MELTEM , FELEKOĞLU ELVAN
Published: June 2005

Sardine (Sardina pilchardus) mince was treated with rosemary extract (RE – 300 ppm) and onion juice (OJ – 1 mL/100 g) then stored at −20C for 5 months. Proximate composition, thiobarbutiric acid (TBA), free fatty acids (FFA) and peroxide value (PV) were determined on 0 and 15 days and 1, 2, 3, 4 and 5 months of storage. Fatty acid composition was also determined on 0 and 5 months of frozen storage. TBA, PV and FFA levels increased on all experimental groups due to the lipid oxidation. RE showed antioxidative effect on sardine mince during frozen storage as indicated by TBA, PV and FFA levels. Oxidation was delayed for 3 months by OJ treatment. At the end of 5 months’ storage, the TBA values in OJ treatment and control (C) treatment were out of consumable limits. After frozen storage of 5 months polyunsaturated fatty acid level decreased and saturated fatty acid level increased in the control treatment. No significant change was observed in fatty acid composition in samples of RE and OJ treatments.
Maximal force, voluntary activation and muscle soreness after eccentric damage to human elbow flexor muscles
Authors: Prasartwuth O. , Taylor J. L. , Gandevia S. C.
Published: June 2005

Muscle damage reduces voluntary force after eccentric exercise but impaired neural drive to the muscle may also contribute. To determine whether the delayed‐onset muscle soreness, which develops ∼1 day after exercise, reduces voluntary activation and to identify the possible site for any reduction, voluntary activation of elbow flexor muscles was examined with both motor cortex and motor nerve stimulation. We measured maximal voluntary isometric torque (MVC), twitch torque, muscle soreness and voluntary activation in eight subjects before, immediately after, 2 h after, 1, 2, 4 and 8 days after eccentric exercise. Motor nerve stimulation and motor cortex stimulation were used to derive twitch torques and measures of voluntary activation. Eccentric exercise immediately reduced the MVC by 38 ± 3% (mean ±s.d., n= 8). The resting twitch produced by motor nerve stimulation fell by 82 ± 6%, and the estimated resting twitch by cortical stimulation fell by 47 ± 15%. While voluntary torque recovered after 8 days, both measures of the resting twitch remained depressed. Muscle tenderness occurred 1–2 days after exercise, and pain during contractions on days 1–4, but changes in voluntary activation did not follow this time course. Voluntary activation assessed with nerve stimulation fell 19 ± 6% immediately after exercise but was not different from control values after 2 days. Voluntary activation assessed by motor cortex stimulation was unchanged by eccentric exercise. During MVCs, absolute increments in torque evoked by nerve and cortical stimulation behaved differently. Those to cortical stimulation decreased whereas those to nerve stimulation tended to increase. These findings suggest that reduced voluntary activation contributes to the early force loss after eccentric exercise, but that it is not due to muscle soreness. The impairment of voluntary activation to nerve stimulation but not motor cortical stimulation suggests that the activation deficit lies in the motor cortex or at a spinal level.
Confocal imaging of [Ca2+] in cellular organelles by SEER, shifted excitation and emission ratioing of fluorescence
Authors: Launikonis Bradley S. , Zhou Jingsong , Royer Leandro , Shannon Thomas R. , Brum Gustavo , Ríos Eduardo
Published: June 2005

Intracellular calcium signals regulate multiple cellular functions. They depend on release of Ca2+ from cellular stores into the cytosol, a process that appears to be tightly controlled by changes in [Ca2+] within the store. A method to image free [Ca2+] within cellular organelles was devised, which provided the first quantitative confocal images of [Ca2+] inside the sarcoplasmic reticulum (SR) of skeletal muscle. The method exploits, for greater sensitivity, the dual spectral shifts that some fluorescent dyes undergo upon binding Ca2+. It was implemented with mag‐indo‐1 trapped in the intracellular organelles of frog skeletal muscle and validated showing that it largely monitors [Ca2+] in a caffeine‐sensitive compartment with the structure of the SR cisternae. A tentative calibration in situ demonstrated an increase in the dye's dissociation constant, not unlike that observed for other dyes in cellular environments. This increase, together with other characteristics of the ratioing method, placed the half‐signal [Ca2+] near 1 mm, a value suitable for cellular stores. Demonstrated advantages of the technique include accuracy (that of a calibrated ratiometric method), dynamic range and sensitivity (from the combination of two spectral shifts), spatial and temporal resolution, and compatibility with a vast array of visible dyes to monitor diverse aspects of cellular function. SEER (shifted excitation and emission ratioing) also provides a [Ca2+]‐independent measure of dye concentration in the cell. Store and mitochondrial [Ca2+] ([Ca2+]SR and [Ca2+]mito) could be measured separately using the high spatial resolution of SEER. Evolution of [Ca2+]SR was followed upon changes in cytosolic [Ca2+] ([Ca2+]cyto). At [Ca2+]cyto= 100 nm, [Ca2+]mito remained near the lower limit of detection and [Ca2+]SR stabilized at values that were submillimolar according to our tentative calibration. Steady [Ca2+]SR was only slightly higher in 800 nm[Ca2+]cyto, and essentially did not decrease unless [Ca2+]cyto was reduced below 10 nm. While the increase of [Ca2+]SR was limited by loss through Ca2+ release channels, its decrease in low [Ca2+]cyto was largely dependent on leaks through the SR Ca2+ pump.
Hemicerebellectomy blocks the enhancement of cortical motor output associated with repetitive somatosensory stimulation in the rat
Authors: Nordeyn Oulad Ben Taib , Mario Manto , Massimo Pandolfo , Jacques Brotchi
Published: June 2005

Repetitive peripheral stimulation is associated with an enhancement of the intensity of corticomotor responses. We analysed the effects of hemicerebellectomy on the modulation of cortical motor output associated with repetitive electrical stimulation of the sciatic nerve in the rat. Hemicerebellectomy blocked the enhancement of the corticomotor response. The cerebellum is a key player in this form of short‐term plasticity.
The influence of small fibre muscle mechanoreceptors on the cardiac vagus in humans
Authors: Gladwell V. F. , Fletcher J. , Patel N. , Elvidge L. J. , Lloyd D. , Chowdhary S. , Coote J. H.
Published: June 2005

We have previously shown that activation of muscle receptors by passive stretch (PS) increases heart rate (HR) with little change in blood pressure (BP). We proposed that PS selectively inhibits cardiac vagal activity. We attempted to test this by performing PS during experimental alterations in vagal tone. Large decreases in vagal tone were induced using either glycopyrrolate or mild rhythmic exercise. Milder alterations in vagal tone were achieved by altering carotid baroreceptor input: neck pressure (NP) or neck suction (NS). PS of the triceps surae was tested in 14 healthy human volunteers. BP, ECG and respiration were recorded. PS alone caused a significant decrease (P< 0.05) in R–R interval (962 ± 76 ms at baseline compared to 846 ± 151 ms with PS), and showed a reduction in HR variability, which was not significant. The decrease in R–R interval with PS was significantly less (P< 0.05,n= 3) following administration of glycopyrrolate (−8.1 ± 4.5 ms) compared to PS alone (−54 ± 11 ms), and also with PS during handgrip (+10 ± 10 ms) compared with PS alone (−74 ± 15 ms) (P< 0.05,n= 5). Milder reductions in vagal activity (NP) resulted in a small but insignificant further decrease in R–R interval in response to PS (−107 ± 17 ms compared to PS alone −96 ± 13 ms,n= 5). Mild increases in vagal activity (NS) during PS resulted in smaller decreases in R–R interval (−39 ± 5.5 ms) compared to PS alone (−86 ± 17 ms) (P< 0.05,n= 8). BP was not significantly changed by stretch in any tests. The results indicate that amongst muscle receptors there is a specific group activated by stretch that selectively inhibit cardiac vagal tone to produce tachycardia.
Profound regulation of neonatal CA1 rat hippocampal GABAergic transmission by functionally distinct kainate receptor populations
Authors: Maingret François , Lauri Sari E. , Taira Tomi , Isaac John T. R.
Published: June 2005

Neonatal hippocampus exhibits distinct patterns of network activity that are dependent on the interaction between inhibitory and excitatory transmission. Kainate receptors are ideally positioned to regulate this activity by virtue of their ability to regulate presynaptic function in GABAergic interneurones. Indeed, kainate receptors are highly expressed in neonatal hippocampal interneurones, yet the role and mechanisms by which they might regulate neonatal circuitry are unexplored. To address this we investigated the kainate receptor‐dependent regulation of GABAergic transmission onto neonatal CA1 pyramidal neurones. Kainate receptor activation produced two distinct opposing effects, a very large increase in the frequency of spontaneous IPSCs, and a robust depression of evoked GABAergic transmission. The up‐regulation of spontaneous transmission was due to activation of somatodendritic and axonal receptors while the depression of evoked transmission could be fully accounted for by a direct regulation of GABA release by kainate receptors located at the terminals. None of the effects of kainate receptor agonists were sensitive to GABAB receptor antagonists, nor was there any postsynaptic kainate receptor‐dependent effects observed in CA1 pyramidal cells that could account for our findings. Our data demonstrate that kainate receptors profoundly regulate neonatal CA1 GABAergic circuitry by two distinct opposing mechanisms, and indicate that these two effects are mediated by functionally distinct populations of receptors. Thus kainate receptors are strategically located to play a critical role in shaping early hippocampal network activity and by virtue of this have a key role in hippocampal development.
Complete Replication of Hepatitis C Virus in Cell Culture
Authors: Lindenbach Brett D. , Evans Matthew J. , Syder Andrew J. , Wölk Benno , Tellinghuisen Timothy L. , Liu Christopher C. , Maruyama Toshiaki , Hynes Richard O. , Burton Dennis R. , McKeating Jane A. , Rice Charles M.
Published: June 2005

Many aspects of the hepatitis C virus (HCV) life cycle have not been reproduced in cell culture, which has slowed research progress on this important human pathogen. Here, we describe a full-length HCV genome that replicates and produces virus particles that are infectious in cell culture (HCVcc). Replication of HCVcc was robust, producing nearly 10
5
infectious units per milliliter within 48 hours. Virus particles were filterable and neutralized with a monoclonal antibody against the viral glycoprotein E2. Viral entry was dependent on cellular expression of a putative HCV receptor, CD81. HCVcc replication was inhibited by interferon-α and by several HCV-specific antiviral compounds, suggesting that this in vitro system will aid in the search for improved antivirals.
Metabolic Engineering in the -omics Era: Elucidating and Modulating Regulatory Networks
Authors: Vemuri Goutham N. , Aristidou Aristos A.
Published: June 2005

The importance of regulatory control in metabolic processes is widely acknowledged, and several enquiries (both local and global) are being made in understanding regulation at various levels of the metabolic hierarchy. The wealth of biological information has enabled identifying the individual components (genes, proteins, and metabolites) of a biological system, and we are now in a position to understand the interactions between these components. Since phenotype is the net result of these interactions, it is immensely important to elucidate them not only for an integrated understanding of physiology, but also for practical applications of using biological systems as cell factories. We present some of the recent “-omics” approaches that have expanded our understanding of regulation at the gene, protein, and metabolite level, followed by analysis of the impact of this progress on the advancement of metabolic engineering. Although this review is by no means exhaustive, we attempt to convey our ideology that combining global information from various levels of metabolic hierarchy is absolutely essential in understanding and subsequently predicting the relationship between changes in gene expression and the resulting phenotype. The ultimate aim of this review is to provide metabolic engineers with an overview of recent advances in complementary aspects of regulation at the gene, protein, and metabolite level and those involved in fundamental research with potential hurdles in the path to implementing their discoveries in practical applications.
Cell Wall Integrity Signaling inSaccharomyces cerevisiae
Authors: Levin David E.
Published: June 2005

The yeast cell wall is a highly dynamic structure that is responsible for protecting the cell from rapid changes in external osmotic potential. The wall is also critical for cell expansion during growth and morphogenesis. This review discusses recent advances in understanding the various signal transduction pathways that allow cells to monitor the state of the cell wall and respond to environmental challenges to this structure. The cell wall integrity signaling pathway controlled by the small G-protein Rho1 is principally responsible for orchestrating changes to the cell wall periodically through the cell cycle and in response to various forms of cell wall stress. This signaling pathway acts through direct control of wall biosynthetic enzymes, transcriptional regulation of cell wall-related genes, and polarization of the actin cytoskeleton. However, additional signaling pathways interface both with the cell wall integrity signaling pathway and with the actin cytoskeleton to coordinate polarized secretion with cell wall expansion. These include Ca2+signaling, phosphatidylinositide signaling at the plasma membrane, sphingoid base signaling through the Pkh1 and -2 protein kinases, Tor kinase signaling, and pathways controlled by the Rho3, Rho4, and Cdc42 G-proteins.
Microbial Dextran-Hydrolyzing Enzymes: Fundamentals and Applications
Authors: Khalikova Elvira , Susi Petri , Korpela Timo
Published: June 2005

Dextran is a chemically and physically complex polymer, breakdown of which is carried out by a variety of endo- and exodextranases. Enzymes in many groups can be classified as dextranases according to function: such enzymes include dextranhydrolases, glucodextranases, exoisomaltohydrolases, exoisomaltotriohydrases, and branched-dextran exo-1,2-α-glucosidases. Cycloisomalto-oligosaccharide glucanotransferase does not formally belong to the dextranases even though its side reaction produces hydrolyzed dextrans. A new classification system for glycosylhydrolases and glycosyltransferases, which is based on amino acid sequence similarities, divides the dextranases into five families. However, this classification is still incomplete since sequence information is missing for many of the enzymes that have been biochemically characterized as dextranases. Dextran-degrading enzymes have been isolated from a wide range of microorganisms. The major characteristics of these enzymes, the methods for analyzing their activities and biological roles, analysis of primary sequence data, and three-dimensional structures of dextranases have been dealt with in this review. Dextranases are promising for future use in various scientific and biotechnological applications.
Enteric Viruses of Humans and Animals in Aquatic Environments: Health Risks, Detection, and Potential Water Quality Assessment Tools
Authors: Fong Theng-Theng , Lipp Erin K.
Published: June 2005

Waterborne enteric viruses threaten both human and animal health. These pathogens are host specific and cause a wide range of diseases and symptoms in humans or other animals. While considerable research has documented the risk of enteric viruses to human health from contact with contaminated water, the current bacterial indicator-based methods for evaluation of water quality are often ineffectual proxies for pathogenic viruses. Additionally, relatively little work has specifically investigated the risk of waterborne viruses to animal health, and this risk currently is not addressed by routine water quality assessments. Nonetheless, because of their host specificity, enteric viruses can fulfill a unique role both for assessing health risks and as measures of contamination source in a watershed, yet the use of animal, as well as human, host-specific viruses in determining sources of fecal pollution has received little attention. With improved molecular detection assays, viruses from key host groups can be targeted directly using PCR amplification or hybridization with a high level of sensitivity and specificity. A multispecies viral analysis would provide needed information for controlling pollution by source, determining human health risks based on assessments of human virus loading and exposure, and determining potential risks to production animal health and could indicate the potential for the presence of other zoonotic pathogens. While there is a need to better understand the prevalence and environmental distribution of nonhuman enteric viruses, the development of improved methods for specific and sensitive detection will facilitate the use of these microbes for library-independent source tracking and water quality assessment tools.
QCD4 GLUEBALL MASSES FROM AdS6 BLACK HOLE DESCRIPTION
Authors: WEN CONG-KAO , YANG HUAN-XIONG
Published: June 2005

By using the generalized version of gauge/gravity correspondence, we study the mass spectra of several typical QCD4 glueballs in the framework of AdS 6 black hole metric of Einstein gravity theory. The obtained glueball mass spectra are numerically in agreement with those from the AdS 7× S 4 black hole metric of the 11-dimensional supergravity.
THREE-BODY COULOMB FINAL-STATE INTERACTION EFFECTS IN THE COULOMB BREAKUP OF LIGHT NUCLEI
Authors: ALT E. O. , IRGAZIEV B. F. , MUKHAMEDZHANOV A. M.
Published: June 2005

Coulomb breakup of a projectile in the Coulomb field of a fully stripped heavy nucleus is at present one of the most popular experimental methods to obtain information on reactions of interest in nuclear astrophysics. Its theoretical interpretation presents, however, considerable difficulties, due to the three-body nature and the infinite range of the Coulomb forces involved. Among the uncertainties affecting present analyses, the possible modification of the dissociation cross-section by three-body Coulomb final-state interactions plays a major role. Various methods which have been proposed to deal with it are briefly reviewed. However, none of them is based on a consistent and mathematically satisfactory quantum mechanical treatment, with the exception of the one proposed recently. The latter, being based on the prior form of the dissociation amplitude, makes use of a genuine three-charged particle wave function for the final state which is an exact solution of the three-body Schrödinger equation, albeit only asymptotically, i.e. for large distances. Nevertheless, interesting conclusion can be drawn concerning the influence of three-body Coulomb final-state interactions on quantities of astrophysical interest.
ASSESSMENTS ON THE MULTIJUNCTION SOLAR CELLS PHOTOELECTRIC EFFICIENCY RELATED TO THE SEMICONDUCTOR BAND GAP AND OUTDOOR CONDITIONS
Authors: PAULESCU M. , TULCAN-PAULESCU E.
Published: June 2005

The solar cell photoelectric efficiency is a concept introduced to assess the energy conversion process of photons into electron-hole pairs. A study on the correlation between photoelectric efficiency and semiconductor materials band gap of multijunction solar cells is presented. This is based on an integrated computer model used to perform the simulations over solar standard spectrum AM1.5G as well as a non-standard case, which includes the cells operating in outdoor conditions. We find that over a diffuse solar flux, the solar cell photoelectric efficiency increases whenever the cells are made from a semiconductor material with band gap higher than that optimized over the AM1.5G spectrum. Consequently, this opens a new possibility to increase the photovoltaic modules efficiency.
IMPROVED SOLID-STATE DBD FOR PICOSECOND SWITCH
Authors: ZHANG FEI , YU WEN , LI CHENGFANG , SHI LINA , SUN XIAOWEI
Published: June 2005

We propose a Si -based delayed breakdown diode (DBD) with an improved three-step gradual changing doping structure for picosecond semiconductor closing switch and discuss the physical process, which underlies the operation principle of high-power closing switch. From the results of two-dimensional mixed device-circuit simulations and theoretical analysis, several parameters of utmost important on the optimal design of picosecond switch are discussed in detail. Performance comparisons of traditional and improved DBDs are given systematically.
TECHNOLOGIES FOR THE FABRICATION OF NANOSCALE SUPERCONDUCTING CIRCUITS
Authors: WATANABE MICHIO
Published: June 2005

Researches on the fabrication of ~ 0.1 × 0.1 μ m 2 superconductor–insulator–superconductor (SIS) Josephson junctions are reviewed. Today, a typical dimension is 1–10 μm for Josephson junctions in superconducting integrated circuits. These Josephson junctions are defined by well-established photolithographic technology with reactive ion etching (RIE), and for the superconductor, Nb is almost always used. The merits of Nb include the facts that the superconducting transition temperature Tc of Nb (9.2 K ) is higher than the boiling point of He (4.2 K ), and that Nb has excellent stability against thermal cycling between room temperature and liquid- He temperature. For the fabrication of ~ 0.1 × 0.1 μ m 2 junctions, on the other hand, there is a standard process with electron-beam lithography, shadow evaporation, and lift-off. This process works well for Al (Tc = 1.2 K ), however, it is not ideal for Nb . The scope of this brief review is the nanoscale junction with Nb electrodes. We will look at the efforts of optimizing the standard lift-off process for Nb , electron-beam-lithographic versions of the Nb Josephson-junction technology, focused-ion-beam (FIB) etching as a convenient alternative to electron-beam lithography and RIE, etc. In order to characterize nanoscale tunnel junctions, the single-charge transistor has been often fabricated. Therefore, a summary of its theoretical transport properties is also included.
INFLUENCE OF OPAL EQUATION OF STATE TO INTERIOR STRUCTURE AND EVOLUTION OF THE SUN
Authors: DURMUS AYSEN , CIVELEK RIKKAT
Published: June 2005

It was computed the interior structure and evolution of the Sun with the OPAL equation of state during the hydrogen burning phase. Theoretical evolution calculations of solar model, starting from threshold of stability point at which gravitational and internal energy are nearly the same, were carried out using Ezer equation of state through the gravitational contraction and premain sequence. Later, during hydrogen burning phase, solar model was constructed with OPAL equation of state which was defined in the temperature range 5000 ≤T ≤108 K . We compared our solar model with recent models computed by other groups and with helioseismic results.
GAUSS–LEGENDRE SKY PIXELIZATION (GLESP) FOR CMB MAPS
Authors: DOROSHKEVICH A. G. , NASELSKY P. D. , VERKHODANOV O. V. , NOVIKOV D. I. , TURCHANINOV V. I. , NOVIKOV I. D. , CHRISTENSEN P. R. , CHIANG L.-Y.
Published: June 2005

A new scheme of sky pixelization is developed for CMB maps. The scheme is based on the Gauss–Legendre polynomials zeros and allows one to create strict orthogonal expansion of the map. A corresponding code has been implemented and comparison with other methods has been done.
HAND–EYE COORDINATION THROUGH ENDPOINT CLOSED-LOOP AND LEARNED ENDPOINT OPEN-LOOP VISUAL SERVO CONTROL
Authors: GASKETT CHRIS , UDE ALEŠ , CHENG GORDON
Published: June 2005

We propose a hand-eye coordination system for a humanoid robot that supports bimanual reaching. The system combines endpoint closed-loop and open-loop visual servo control. The closed-loop component moves the eyes, head, arms, and torso, based on the position of the target and the robot's hands, as seen by the robot's head-mounted cameras. The open-loop component uses a motor-motor mapping that is learnt online to support movement when visual cues are not available.
A THEORY OF DEVELOPMENTAL MENTAL ARCHITECTURE AND THE DAV ARCHITECTURE DESIGN
Authors: WENG JUYANG , ZENG SHUQING
Published: June 2005

The software architecture of a developmental robot is a challenging new research subject. This paper presents a theory of developmental mental architecture. Five architecture types, from the simplest Type-1 (observation-driven Markov decision process) to Type-5 (DOSASE MDP), are introduced. The properties and limitations of a simpler one are discussed before the introduction of the next more complex one. Further, we present the architecture design of the Dav robot, a humanoid robot built in the Embodied Intelligence Laboratory at Michigan State University. The framework of the Dav architecture is hand-designed, but the actual controller is developed, i.e. generated autonomously by the developmental program through real-time, online interactions with the real physical environment. We present the Dav architecture and the major components that realize the architecture. The designed architecture for Dav is the next generation version from its extensively tested predecessor, the SAIL developmental robot. Closely related to the issue of performance metrics, the paper also introduces the notion of intelligence completeness (concept completeness, intelligence-metric completeness, and factor completeness) and establishes the concept of the completeness theorem for developmental robotics.
BILINEAR ESTIMATES ON CURVED SPACE–TIMES
Authors: KLAINERMAN SERGIU , RODNIANSKI IGOR
Published: June 2005

To settle the L2bounded curvature conjecture for the Einstein-vaccum equations one needs to prove bilinear type estimates for solutions of the homogeneous wave equation on a fixed background with H2local regularity. In this paper we introduce a notion of primitive parametrix for the homogeneous wave equation for which we can prove, under very broad assumptions, the desired bilinear estimates.
COSMOLOGICAL SINGULARITIES, EINSTEIN BILLIARDS AND LORENTZIAN KAC–MOODY ALGEBRAS
Authors: DAMOUR THIBAULT
Published: June 2005

The structure of the general, inhomogeneous solution of (bosonic) Einstein-matter systems in the vicinity of a cosmological singularity is considered. We review the proof (based on ideas of Belinskii–Khalatnikov–Lifshitz and technically simplified by the use of the Arnowitt–Deser–Misner Hamiltonian formalism) that the asymptotic behavior, as one approaches the singularity, of the general solution is describable, at each (generic) spatial point, as a billiard motion in an auxiliary Lorentzian space. For certain Einstein-matter systems, notably for pure Einstein gravity in any spacetime dimension D and for the particular Einstein-matter systems arising in String Theory, the billiard tables describing asymptotic cosmological behavior are found to be identical to the Weyl chambers of some Lorentzian Kac–Moody algebras. In the case of the bosonic sector of supergravity in 11 dimensional spacetime the underlying Lorentzian algebra is that of the hyperbolic Kac–Moody group E10, and there exists some evidence of a correspondence between the general solution of the Einstein-three-form system and a null geodesic in the infinite dimensional coset space E10/K(E10), where K(E10) is the maximal compact subgroup of E10.
DYNAMICAL PROPERTIES OF COSMOLOGICAL SOLUTIONS
Authors: ELLIS GEORGE F. R.
Published: June 2005

I will consider how there are FOSH formulations and associated results in relativistic cosmology expressed in 1+3 tetrad form. The characteristics of scalar and vector perturbations are timelike, hence the real domains of dependence in cosmology are much smaller than implied by the light cone, associated with gravitational wave perturbations.
THE SPACE OF COSMOLOGICAL SPACE–TIMES
Authors: ELLIS GEORGE F. R.
Published: June 2005

I first focus on how to best describe the space of cosmological space–times and what its essential properties are and some comments on the dynamical behavior revealed by studies that will be described in more detail by John Wainwright. I will then relate this both to observations and to anthropic issues (i.e. the possible existence of observers). This space includes some viable singularity free solutions which will be briefly described, thus posing the issue of the tension between very special initial conditions and the existence of initial singularities. I will conclude with remarks on the issue of realized infinities in this context and the concept of multiverses.
A MODEL PROBLEM FOR THE INITIAL-BOUNDARY VALUE FORMULATION OF EINSTEIN'S FIELD EQUATIONS
Authors: REULA OSCAR , SARBACH OLIVIER
Published: June 2005

In many numerical implementations of the Cauchy formulation of Einstein's field equations one encounters artificial boundaries which raises the issue of specifying boundary conditions. Such conditions have to be chosen carefully. In particular, they should be compatible with the constraints, yield a well posed initial-boundary value formulation and incorporate some physically desirable properties like, for instance, minimizing reflections of gravitational radiation.

Motivated by the problem in General Relativity, we analyze a model problem, consisting of a formulation of Maxwell's equations on a spatially compact region of space–time with timelike boundaries. The form in which the equations are written is such that their structure is very similar to the Einstein–Christoffel symmetric hyperbolic formulations of Einstein's field equations. For this model problem, we specify a family of Sommerfeld-type constraint-preserving boundary conditions and show that the resulting initial-boundary value formulations are well posed. We expect that these results can be generalized to the Einstein–Christoffel formulations of General Relativity, at least in the case of linearizations about a stationary background.
ROUGH SOLUTIONS OF THE EINSTEIN CONSTRAINT EQUATIONS ON COMPACT MANIFOLDS
Authors: MAXWELL DAVID
Published: June 2005

We construct low regularity solutions of the vacuum Einstein constraint equations on compact manifolds. On 3-manifolds we obtain solutions with metrics in Hs where s > 3/2. The constant mean curvature (CMC) conformal method leads to a construction of all CMC initial data with this level of regularity. These results extend a construction from [10] that treated the asymptotically Euclidean case.
NULL SURFACES AND CONTACT GEOMETRY
Authors: FRITTELLI S. , KAMRAN N. , KOZAMEH C. , NEWMAN E. T.
Published: June 2005

We give a self-contained and geometric account of a recent approach to the Einstein field equations of general relativity, based on families of null foliations of space–time. We then use exterior differential systems to make explicit the correspondence between conformal Lorentzian geometry in dimensions three and four and the contact geometry of special classes of differential systems.
CURVATURE BLOW UP ON A DENSE SUBSET OF THE SINGULARITY IN T3-GOWDY
Authors: RINGSTRÖM HANS
Published: June 2005

This paper is concerned with the Einstein vacuum equations under the additional assumption of T3-Gowdy symmetry. We prove that there is a generic set of initial data such that the corresponding solutions exhibit curvature blow up on a dense subset of the singularity. By generic, we mean a countable intersection of open sets (i.e. a Gδ set) which is also dense. Furthermore, the set of initial data is given the C∞ topology. This result was presented at a conference in Miami 2004. Recently, we have obtained a stronger result, but the argument to prove it is different and much longer. Therefore, we here wish to present the original argument. Finally, combining the results presented here with a paper by Chruściel and Lake, one obtains strong cosmic censorship for T3-Gowdy spacetimes.
COSMOLOGICAL MODELS FROM A DYNAMICAL SYSTEMS PERSPECTIVE
Authors: WAINWRIGHT J. , LIM W. C.
Published: June 2005

It is useful to study the space of all cosmological models from a dynamical systems perspective, that is, by formulating the Einstein field equations as a dynamical system using appropriately normalized variables. We will discuss various aspects of this work, the choices of normalization factor, multiple representations of models, the past attractor, nonlinear dynamics in close-to-Friedmann–Lemaître models, Weyl curvature dominance, and numerical simulations.
PROOF OF THE RIGIDITY OF HYPERBOLIC SPACES USING QUASILOCAL MASS TYPE THEOREMS
Authors: MIAO PENGZI
Published: June 2005

A proof of the rigidity of hyperbolic spaces is given for a class of conformally compact manifolds whose conformal infinity is the standard sphere. The method is based on quasilocal mass type theorems in general relativity.
Metabolic and cellular plasticity in white adipose tissue II: role of peroxisome proliferator-activated receptor-α
Authors: Li Pipeng , Zhu Zhengxian , Lu Yuyan , Granneman James G.
Published: June 2005

Chronic activation of adipocyte β-adrenergic receptors induces remodeling of white adipose tissue (WAT) that includes a transient inflammatory response followed by mitochondrial biogenesis, induction of fatty acid oxidation genes, and elevation of tissue oxidative metabolism. Gene profiling experiments of WAT during remodeling induced by the β3-adrenergic receptor agonist CL-316,243 (CL) suggested that peroxisome proliferator-activated receptor-α (Ppara), which is upregulated by CL, might be an important transcriptional regulator of that process. Histological, physiological, and molecular analysis of CL-induced remodeling in wild-type mice and mice lacking Ppara demonstrated that Ppara was important for inducing adipocyte mitochondrial biogenesis and upregulating genes involved in fatty acid oxidation. Furthermore, Ppara-deficient mice exhibited sustained WAT inflammation during CL treatment, indicating that upregulation of Ppara limits proinflammatory signaling during chronic lipolytic activation. Together, these data support the hypothesis that WAT remodeling is an adaptive response to excessive fatty acid mobilization whereby Ppara and its downstream targets elevate fatty acid catabolism and suppress proinflammatory signaling.
Impaired glucagon secretory responses in mice lacking the type 1 sulfonylurea receptor
Authors: Shiota Chiyo , Rocheleau Jonathan V. , Shiota Masakazu , Piston David W. , Magnuson Mark A.
Published: June 2005

Pancreatic α-cells, like β-cells, express ATP-sensitive K+(KATP) channels. To determine the physiological role of KATPchannels in α-cells, we examined glucagon secretion in mice lacking the type 1 sulfonylurea receptor ( Sur1). Plasma glucagon levels, which were increased in wild-type mice after an overnight fast, did not change in Sur1 null mice. Pancreas perfusion studies showed that Sur1 null pancreata lacked glucagon secretory responses to hypoglycemia and to synergistic stimulation by arginine. Pancreatic α-cells isolated from wild-type animals exhibited oscillations of intracellular free Ca2+concentration ([Ca2+]i) in the absence of glucose that became quiescent when the glucose concentration was increased. In contrast, Sur1 null α-cells showed continuous oscillations in [Ca2+]iregardless of the glucose concentration. These findings indicate that KATPchannels in α-cells play a key role in regulating glucagon secretion, thereby adding to the paradox of how mice that lack KATPchannels maintain euglycemia.
Sodium lactate increases LPS-stimulated MMP and cytokine expression in U937 histiocytes by enhancing AP-1 and NF-κB transcriptional activities
Authors: Nareika Alena , He Lin , Game Bryan A. , Slate Elizabeth H. , Sanders John J. , London Steven D. , Lopes-Virella Maria F. , Huang Yan
Published: June 2005

The plasma lactate concentration in patients with obesity and type 2 diabetes is often higher than that in nondiabetic individuals. Although it is known that increased lactate concentration is an independent risk factor for developing type 2 diabetes, the underlying mechanisms are not well understood. Because inflammation plays an important role in the development of type 2 diabetes, we postulated that increased lactate level might contribute to the pathogenesis of type 2 diabetes by enhancing inflammation. In the present study, we demonstrated that preexposure of U937 macrophage-like cells to sodium lactate increased LPS-stimulated matrix metalloproteinase (MMP)-1, IL-1β, and IL-6 secretion. Augmentation of LPS-stimulated MMP-1 secretion was diminished when sodium lactate was replaced by lactic acid that reduced pH in the culture medium. Furthermore, quantitative real-time PCR indicated that the increased secretion of MMP-1, IL-1β, and IL-6 was due to increased mRNA expression. To explore the underlying signaling mechanism, blocking studies using specific inhibitors for NF-κB and MAPK cascades were performed. Results showed that blocking of either NF-κB or MAPK pathways led to the inhibition of MMP-1, IL-1β, and IL-6 expression stimulated by sodium lactate, LPS, or both. Finally, electrophoretic mobility shift assays showed a synergy between sodium lactate and LPS on AP-1 and NF-κB transcriptional activities. In conclusion, this study has demonstrated for the first time that sodium lactate and LPS exert synergistic effect on MMP and cytokine expression through NF-κB and MAPK pathways and revealed a novel mechanism potentially involved in the development of type 2 diabetes and its complications.
Weight loss increases cardiovagal baroreflex function in obese young and older men
Authors: Alvarez Guy E. , Davy Brenda M. , Ballard Tasha P. , Beske Stacy D. , Davy Kevin P.
Published: June 2005

We tested the hypothesis that reductions in total body and abdominal visceral fat with energy restriction would be associated with increases in cardiovagal baroreflex sensitivity (BRS) in overweight/obese older men. To address this, overweight/obese (25 ≤ body mass index ≤ 35 kg/m2) young (OB-Y, n = 10, age = 32.9 ± 2.3 yr) and older (OB-O, n = 6, age = 60 ± 2.7 yr) men underwent 3 mo of energy restriction at a level designed to reduce body weight by 5–10%. Cardiovagal BRS (modified Oxford technique), body composition (dual-energy X-ray absorptiometry), and abdominal fat distribution (computed tomography) were measured in the overweight/obese men before weight loss and after 4 wk of weight stability at their reduced weight and compared with a group of nonobese young men (NO-Y, n = 13, age = 21.1 ± 1.0 yr). Before weight loss, cardiovagal BRS was ∼35% and ∼60% lower ( P < 0.05) in the OB-Y and OB-O compared with NO-Y. Body weight (−7.8 ± 1.1 vs. −7.3 ± 0.7 kg), total fat mass (−4.1 ± 1.0 vs. −4.4 ± 0.8 kg), and abdominal visceral fat (−27.6 ± 6.9 vs. −43.5 ± 10.1 cm2) were reduced (all P < 0.05) after weight loss, but the magnitude of reduction did not differ (all P > 0.05) between OB-Y and OB-O, respectively. Cardiovagal BRS increased (11.5 ± 1.9 vs. 18.5 ± 2.6 ms/mmHg and 6.7 ± 1.2 vs. 12.8 ± 4.2 ms/mmHg) after weight loss (both P < 0.05) in OB-Y and OB-O, respectively. After weight loss, cardiovagal BRS in the obese/overweight young and older men was ∼105% and ∼73% ( P > 0.05) of NO-Y (17.5 ± 2.2 ms/mmHg). Therefore, the results of this study indicate that weight loss increases the sensitivity of the cardiovagal baroreflex in overweight/obese young and older men.
Cardiac and renal antioxidant enzymes and effects of tempol in hyperthyroid rats
Authors: Moreno Juan Manuel , Gómez Isabel Rodríguez , Wangensteen Rosemary , Osuna Antonio , Bueno Pablo , Vargas Félix
Published: June 2005

This study evaluated the activity of cardiac and renal antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR)] and whether chronic treatment with tempol, a cell membrane-permeable SOD mimetic, ameliorates the hypertension of hyperthyroidism. Two experiments were performed. In experiment I, the following four groups of male Wistar rats were used: control group and three groups that received thyroxine (T4) at 10, 50, or 75 μg·rat−1·day−1. In experiment II, tempol was orally administered (18 mg·kg−1·day−1) to control and T4-treated (75 μg·rat−1·day−1) rats. All treatments were maintained for 6 wk. Body weight, tail systolic blood pressure (BP), and heart rate were measured one time a week, and direct BP and morphological, metabolic, plasma, and renal variables were measured at the end of the experiment. Enzymatic activities were measured in renal cortex and medulla and right and left ventricles. In renal cortex, SOD activity was decreased in the T4-75 group, and there was a dose-related increase in CAT activity and decrease in GPX and GR activities in T4-treated groups. Activity of all antioxidant enzymes was reduced in left ventricle in T4-50 and T4-75 groups and in right ventricle in the T4-75 group. Tempol reduced BP, plasma malondialdehyde, and total urinary excretion of F2isoprostanes in hypertensive hyperthyroid rats but not in controls. Tempol did not improve cardiac hypertrophy, proteinuria, or creatinine clearance in hyperthyroid rats. In conclusion, the results obtained indicate that the activity of SOD, GPX, and GR in renal and cardiac tissues is decreased in hyperthyroidism and that antioxidant treatment with tempol ameliorates T4-induced hypertension.
Impaired cardiac and sympathetic autonomic control in rats differing in acetylcholine receptor sensitivity
Authors: Padley James R. , Overstreet David H. , Pilowsky Paul M. , Goodchild Ann K.
Published: June 2005

Acetylcholine receptors (AChR) are important in premotor and efferent control of autonomic function; however, the extent to which cardiovascular function is affected by genetic variations in AChR sensitivity is unknown. We assessed heart rate variability (HRV) and baroreflex sensitivity (BRS) in rats bred for resistance (FRL) or sensitivity (FSL) to cholinergic agents compared with Sprague-Dawley rats (SD), confirmed by using hypothermic responses evoked by the muscarinic agonist oxotremorine (0.2 mg/kg ip) ( n ≥ 9 rats/group). Arterial pressure, ECG, and splanchnic sympathetic (SNA) and phrenic (PNA) nerve activities were acquired under anesthesia (urethane 1.3 g/kg ip). HRV was assessed in time and frequency domains from short-term R-R interval data, and spontaneous heart rate BRS was obtained by using a sequence method at rest and after administration of atropine methylnitrate (mATR, 2 mg/kg iv). Heart rate and SNA baroreflex gains were assessed by using conventional pharmacological methods. FRL and FSL were normotensive but displayed elevated heart rates, reduced HRV and HF power, and spontaneous BRS compared with SD. mATR had no effect on these parameters in FRL or FSL, indicating reduced cardiovagal tone. FSL exhibited reduced PNA frequency, longer baroreflex latency, and reduced baroreflex gain of heart rate and SNA compared with FRL and SD, indicating in FSL dual impairment of cardiac and circulatory baroreflexes. These findings show that AChR resistance results in reduced cardiac muscarinic receptor function leading to cardiovagal insufficiency. In contrast, AChR sensitivity results in autonomic and respiratory abnormalities arising from alterations in central muscarinic and or other neurotransmitter receptors.
Renal vascular response to static handgrip exercise: sympathetic vs. autoregulatory control
Authors: Momen Afsana , Bower Douglas , Leuenberger Urs A. , Boehmer John , Lerner Susan , Alfrey Edward J. , Handly Brian , Sinoway Lawrence I.
Published: June 2005

Static exercise causes activation of the sympathetic nervous system, which results in increased blood pressure (BP) and renal vascular resistance (RVR). The question arises as to whether renal vasoconstriction that occurs during static exercise is due to sympathetic activation and/or related to a pressure-dependent renal autoregulatory mechanism. To address this issue, we monitored renal blood flow velocity (RBV) responses to two different handgrip (HG) exercise paradigms in 7 kidney transplant recipients (RTX) and 11 age-matched healthy control subjects. Transplanted kidneys are functionally denervated. Beat-by-beat analyses of changes in RBV (observed via duplex ultrasound), BP, and heart rate were performed during HG exercise in all subjects. An index of RVR was calculated as BP/RBV. In protocol 1, fatiguing HG exercise (40% of maximum voluntary contraction) led to significant increases in RVR in both groups. However, at the end of exercise, RVR was more than fourfold higher in control subjects than in the RTX group (88 vs. 20% increase over baseline; interaction, P < 0.001). In protocol 2, short bouts of HG exercise (15 s) led to significant increases in RVR at higher workloads (50 and 70% of maximum voluntary contraction) in the control subjects ( P < 0.001). RVR did not increase in the RTX group. In conclusion, we observed grossly attenuated renal vasoconstrictor responses to exercise in RTX subjects, in whom transplanted kidneys were considered functionally denervated. Our results suggest that renal vasoconstrictor responses to exercise in conscious humans are mainly dependent on activation of a neural mechanism.