bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF SHELF LIFE AND SPOILAGE PATTERN OF AEROBICALLY STORED BUFFALO LIVER
Authors: DEVATKAL SURESH , MENDIRATTA S.K.
Published: July 2007

Buffalo meat significantly contributes toward sustainability of food chain in India and in developing countries. Buffalo liver is an important edible by‐product that can provide essential nutrients at a lower cost if utilized effectively. In this study, the shelf life and spoilage pattern of aerobically stored buffalo liver at 4 ± 1C were evaluated based on changes in pH, extract release volume (ERV), aerobic plate counts (APCs) at 37C; APC at 20C; and organoleptic scores. A significant (P < 0.05) decrease of pH from 6.43 to 5.96 was observed during 6 days of storage. An ERV value of 1.27 mL on day 0 gradually increased to 4.48 mL on the sixth day of storage. The average values of APC at 37C were 4.96, 5.76, 6.53 and 7.15 log10 cfu/g on days 0, 2, 4 and 6, respectively. Similarly, the mean values of APC at 20C were 5.23, 6.50, 7.10 and 7.48 log10 cfu/g on days 0, 2, 4 and 6, respectively. An organoleptic evaluation indicated that liver spoilage organisms preferentially utilize simple carbohydrates, such as glucose, and do not produce offensive odor during the initial storage period. The high glucose content of liver allows the spoilage bacteria to form visible colonies on the exposed surface before any off‐odor develops. These findings suggest that odor parameter may not be useful for the assessment of shelf life of liver, because an off‐odor appeared when microbial counts were log7 cfu/g and the livers have been previously rejected for overall appearance and the presence of surface colonies. Therefore, based on these results of shelf‐life evaluation, it was concluded that buffalo liver was acceptable microbiologically and organoleptically up to the third day of storage at 4C.
EFFECTS OF FAT LEVEL AND STORAGE TIME ON LIPID AND COLOR STABILITY OF NATURALLY FERMENTED TURKISH SAUSAGES (SUCUK)
Authors: SOYER AYLA , ERTAS AHMET HAMDI
Published: July 2007

Lipid oxidation, lipolysis and color stability of naturally fermented Turkish sausages with different initial fat content (10, 20 and 30%) were studied during 60 days of storage of the vacuum‐packed sausages at 4 ± 2°C. During storage, thiobarbituric acid (TBA) and total free fatty acids (FFAs) were measured to determine lipid oxidation and lipolysis. Changes in color were determined by measuring Commission Internationale de l'Eclairage (CIE) L* (lightness), a* (redness) and b* (yellowness) color variables. Vacuum packing prevented any drying. Initial fat content and storage time had a significant impact on FFA and TBA values of sausages. High fat contents and prolonged storage times resulted in high lipolytic activity and lipid oxidation. CIE L*, a* and b* color variables of the sausages were affected by fat content, whereas only the a* variable was affected by storage time. Higher initial fat content in the sausages and residual oxygen in vacuum packing could be responsible for the observed differences in oxidative stability. Lipid and color stability were not maintained in vacuum‐packed sausages with a high fat content.
Guidelines on the insertion and management of central venous access devices in adults
Authors: BISHOP L. , DOUGHERTY L. , BODENHAM A. , MANSI J. , CROWE P. , KIBBLER C. , SHANNON M. , TRELEAVEN J.
Published: July 2007

Central venous access devices are used in many branched of medicine where venous access is required for either long‐term or a short‐term care. These guidelines review the types of access devices available and make a number of major recommendations. Their respective advantages and disadvantages in various clinical settings are outlined. Patient care prior to, and immediately following insertion is discussed in the context of possible complications and how these are best avoided. There is a section addressing long‐term care of in‐dwelling devices. Techniques of insertion and removal are reviewed and management of the problems which are most likely to occur following insertion including infection, misplacement and thrombosis are discussed. Care of patients with coagulopathies is addressed and there is a section addressing catheter‐related problems.
Protective effects of BML‐111, a lipoxin A4 receptor agonist, on carbon tetrachloride‐induced liver injury in mice
Authors: Zhang Li , Wan Jingyuan , Li Hongzhong , Wu Ping , Jin Shengwei , Zhou Xiaoyan , Yuan Ping , Xiong Wei , Li Yongsheng , Ye Duyun
Published: July 2007

Background:  Lipoxins (LX) are trihydroxytetraene‐containing eicosanoids that display unique anti‐inflammatory and pro‐resolving actions during various inflammatory conditions, but the pathophysiological significance of LX in liver disorders remains unknown.

Methods:  In the present study, we used a murine model of carbon tetrachloride (CCl4)‐induced acute liver injury to investigate the effects of LX on the progression of acute liver injury.

Results:  The results indicated that the lipoxin A4 receptor (ALX) was upregulated after giving CCl4. BML‐111, a commercially available ALX agonist, effectively protected the liver from CCl4‐induced injury as evidenced by decreased serum aminotransferase (ALT, AST) levels and improved histological damage. The dampened liver injury was accompanied byreduced malondialdehyde (MDA) content in liver homogenates and decreased concentration of tumor necrosis factor‐α (TNF‐α) in the serum. Most interestingly, BML‐111 markedly upregulated hepatic heme oxygenase‐1 (HO‐1) expression in CCl4‐treated mice, which might provide antioxidative activities in the liver.

Conclusion:  These data indicate that ALX agonist BML‐111 plays a critical protective role in CCl4‐induced acute liver injury through limiting the inflammatory response and promoting antioxidative protein expression.
Separation of large mammalian ventricular myosin differing in ATPase activityThis paper is one of a selection of papers published in this Special Issue, entitled The Cellular and Molecular Basis of Cardiovascular Dysfunction, Dhalla 70th Birthday Tribute.
Authors: Rupp Heinz , Maisch Bernhard
Published: July 2007

To investigate a possible heterogeneity of human ventricular myosin, papillary muscles of patients with valvular dysfunction were examined using a modified native gel electrophoresis. Myosin was separated into 2 components termed VA and VB, whereby the VA to VB proportion appeared to depend on the ventricular load. The proportion of the faster migrating band VA was correlated (P < 0.05) with end-diastolic pressure and the aortic pressure-cardiac index product. The regression based on these variables accounted for 67% of the variation in VA (R2 = 0.67). The VA proportion was, however, not significantly correlated with cardiac norepinephrine concentration. The ATPase activity of the 2 components of myosin was assessed from the Ca3(PO4)2 precipitation by incubating the gel in the presence of ATP and CaCl2. The ATPase activity of VA was 60% of that of VB. The VA and VB forms were observed also in the cat (31.4% VA), dog (32.1% VA), pig (28.5% VA), wild pig (33.7% VA), and roe deer (30.5% VA). VA and VB were not detected in the rat exhibiting the 3 isoforms V1, V2, and V3, rabbit (100% V3), and hare (86% V1). The data demonstrate a heterogeneity of large mammalian ventricular myosin, whereby an increased cardiac load appeared to be associated with a higher myosin VA proportion that exhibited a reduced ATPase activity.
EQUATIONS IN FREE INVERSE MONOIDS
Authors: DEIS TIMOTHY , MEAKIN JOHN , SÉNIZERGUES G.
Published: July 2007

It is known that the problem of determining consistency of a finite system of equations in a free group or a free monoid is decidable, but the corresponding problem for systems of equations in a free inverse monoid of rank at least two is undecidable. Any solution to a system of equations in a free inverse monoid induces a solution to the corresponding system of equations in the associated free group in an obvious way, but solutions to systems of equations in free groups do not necessarily lift to solutions in free inverse monoids. In this paper, we show that the problem of determining whether a solution to a finite system of equations in a free group can be extended to a solution of the corresponding system in the associated free inverse monoid is decidable. We are able to use this to solve the consistency problem for certain classes of single-variable equations in free inverse monoids.
SOLVABILITY OF SYSTEMS OF POLYNOMIAL EQUATIONS OVER FINITE ALGEBRAS
Authors: ZÁDORI LÁSZLÓ
Published: July 2007

We study the algorithmic complexity of determining whether a system of polynomial equations over a finite algebra admits a solution. We prove that the problem has a dichotomy in the class of finite groupoids with an identity element. By developing the underlying idea further, we present a dichotomy theorem in the class of finite algebras that admit a non-trivial idempotent Maltsev condition. This is a substantial extension of most of the earlier results on the topic.
LIMIT GROUPS ARE CONJUGACY SEPARABLE
Authors: CHAGAS S. C. , ZALESSKII P. A.
Published: July 2007

A limit group is a finitely-generated subgroup of a fully residually free group. We prove in this paper the result announced in the title.
RANDOMIZED METHODS IN ARTIN GROUPS OF FINITE TYPE
Authors: BRADSHAW ROBERT W. , HUMPHRIES STEPHEN P.
Published: July 2007

We investigate the use of random algorithms for the solution of the conjugacy problems for certain types of Artin groups of finite type including the braid groups.
ON BOUNDED ARTINIAN-FINITARY MODULES
Authors: KURDACHENKO L. A. , SUBBOTIN I. YA. , CHUPORDYA V. A.
Published: July 2007

Let G be a group, R be a ring and A be an RG-module. We say that A is an Artinian-finitary module overRG if for every element g ∈ G, the factor-module A/CA(g) is an Artinian R-module. The study of these modules was initiated by Wehrfritz. If D is a Dedekind domain and U is an Artinian D-module, then we can associate with U some numerical invariants. If V is the maximal divisible submodule of U, then V is a direct sum of finitely many indecomposable submodules. The number bd(U) of these direct summands is an invariant of U. The composition length bF(U/V) of U/V is another invariant of U. We consider the following special case of Artinian-finitary modules. Let D be a Dedekind domain and G be a group. The DG-module A is said to be bounded Artinian-finitary, if A is Artinian-finitary and there are the numbers bF(A) = b, bd(A) = d ∈ ℕ and a finite subset bσ(A) = τ Spec (D) such that lF(A/CA(g)) ≤ b, ld(A/CA(g)) ≤ d and Ass D(A/CA(g)) ⊆ τ for every element g ∈ G. In the article, the bounded Artinian-finitary modules under some natural restriction are studied.
DERIVATIONS OF THE EVEN PARTS FOR MODULAR LIE SUPERALGEBRAS OF CARTAN TYPE W AND S
Authors: LIU WENDE , ZHANG YONGZHENG
Published: July 2007

Let 𝔽 be the underlying base field of characteristic p < 3 and denote by [Formula: see text] and [Formula: see text] the even parts of the finite-dimensional generalized Witt Lie superalgebra W and the special Lie superalgebra S, respectively. We first give the generator sets of the Lie algebras [Formula: see text] and [Formula: see text]. Using certain properties of the canonical tori of [Formula: see text] and [Formula: see text], we then determine the derivation algebra of [Formula: see text] and the derivation space of [Formula: see text] to [Formula: see text], where [Formula: see text] is viewed as a [Formula: see text]-module by means of the adjoint representation. As a result, we describe explicitly the derivation algebra of [Formula: see text]. Furthermore, we prove that the outer derivation algebras of [Formula: see text] and [Formula: see text] are abelian Lie algebras or metabelian Lie algebras with explicit structure. In particular, we give the dimension formulas of the derivation algebras and outer derivation algebras of [Formula: see text] and [Formula: see text]. Thus, we may make a comparison between the even parts of the (outer) superderivation algebras of W and S and the (outer) derivation algebras of the even parts of W and S, respectively.
OPTICAL ASPECTS OF POROUS MC-SILICON UNDER HEAT TREATMENTS
Authors: MOUSSI A. , BOUHAFS D. , BENREGUIA N. , MAHIOU L. , BELKAID M. S.
Published: July 2007

The aim of this study is the formation of porous silicon (PS) and the heat treatment effect on the optical properties of the PS layer. An optimized HF:HNO3 chemical solution is used at ambient temperature on the n + p silicon surface. Scanning electron microscopy (SEM) pictures show the form of the nanopores. We studied the effect of the heating on the morphology and the reflection of the PS layer. A chemical analysis of the surface is also carried out. The measurements show that the pore shape and the oxygen content on the surface are changing with temperature. Specular reflection spectra under variable incidence angles are measured on each treated surface. Curves of weighted reflection R w are drawn to illustrate the evolution with temperature. The modification of oxygen content of the porous surface is correlated with the sheet resistance of the emitter. Results show the lower the oxygen percent the lower the resistivity. The layout of R w according to the temperature of annealing indicates that the shape of the curve is the same for the angles of incidences 20°, 30°, 40°, and 50°. At a low temperature R w is minimal indicating the presence of an oxide coating on the porous layer an indication of optical adaptation between the air and the substrate of silicon.
TRIBOLOGICAL BEHAVIORS OF DUPLEX DLC/Al2O3 COATINGS FABRICATED USING MICRO-ARC OXIDATION AND FILTERED CATHODIC VACUUM ARC SYSTEM
Authors: WU X. L. , LI X. J. , ZHANG X. , XUE W. B. , CHENG G. A. , LIU A. D.
Published: July 2007

Micro-arc oxidation technique (MAO) treatment produces a layer of alumina film on the surface of the aluminum alloy. A hard and uniform tetrahedral amorphous carbon film (diamond-like carbon, DLC) was deposited on the top of the alumina layer of the 2024 aluminum alloy by a pulsed filtered catholic vacuum arc (FCVA) deposition system with a metal vapor vacuum arc (MEVVA) source. The morphology and tribological properties of the duplex DLC/ Al 2 O 3 coating were investigated by a scanning electron microscope (SEM) and a ball-on-disk sliding tester. These results suggested that the duplex DLC/ Al 2 O 3 coating had good adhesion and a low friction coefficient, which improved significantly the wear resistance of aluminum alloys.
PREPARATION AND DETERMINATION OF OPTICAL PROPERTIES OF NiO THIN FILMS DEPOSITED BY DIP COATING TECHNIQUE
Authors: GHODSI F. E. , KHAYATIYAN S. A.
Published: July 2007

The NiO thin films were prepared from NiCl 2 · 6 H 2 O precursor by using sol–gel route. The films were deposited on a glass substrate using dip-coating technique. The optical and structural properties of the NiO thin films were investigated with respect to dipping rate, number of layers, and annealing temperature. The microstructure of NiO thin films and powder were examined by X-ray diffraction (XRD). Various diffraction peaks of NiO powder were observed in the XRD pattern. The morphology of the films was studied by using scanning electron microscopy (SEM). The optical characteristics of the samples were determined by using UV–visible spectrophotometer. The results show that the NiO thin films are transparent in the visible range. Optical constants (refractive index, extinction coefficient…) were changed by varying dipping rate, number of layers, and annealing temperature.
MECHANISM OF SILICA NANO-PLATE FORMATION FROM LUCENTITE
Authors: TRAN N. H. , WILSON M. A. , MILEV A. S. , DENNIS G. R. , KANNANGARA G. S. K.
Published: July 2007

The mechanism of formation of silica nano-plates by exfoliation of a phyllosilicate magnesium containing clay, Lucentite, in an aqueous solution of poly(acrylic acid) has been studied. Fourier transform infrared spectroscopy and Mg K -edge near edge X-ray adsorption fine structure (NEXAFS) analysis shows that non-surface (bulk) Mg ions were not chemically involved in the poly(acrylic acid)/clay intercalation, but were substantially involved in the exfoliation resulting in the silica nano-plates. During intercalation, O K -edge NEXAFS shows that surface defects were formed which represent additional structural branches on the surface. During exfoliation, these increased significantly. Si L3,2-edge NEXAFS measurements shows that this occurred by migration of SiO 4 groups within the exfoliated silica plates.
ELECTROLESS PLATING OF COPPER ON POLYTETRAFLUOROETHYLENE FILMS MODIFIED BY SURFACE-INITIATED FREE RADICAL POLYMERIZATION OF 4-VINYLPYRIDINE
Authors: CHEN YIWANG , SUN WEI , DENG QILAN , CHEN LIE , HE XIAOHUI
Published: July 2007

Surface modification of polytetrafluoroethylene (PTFE) films is done by exposing the films to a sodium naphthalenide ( Na /naphtha) etchant, and esterification of 4,4'-azobis(4-cyanopentanoic acid) (ACP) with the hydroxyl groups covalently linked to the surface, followed by the surface-initiated free radical polymerization of 4-vinylpyridine (4 VP). The surface elemental composition and topography of the poly(4-vinylpyridine) (PVP) graft-functionalized PTFE surfaces (PTFE-g-PVP surfaces) were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance (ATR) FTIR spectroscopy, and atomic force microscopy (AFM). Water contact angles on the pristine PTFE surface and PTFE-g-PVP surfaces were measured. The PVP brushes on the PTFE surface with well-preserved pyridine groups were used not only as the chemisorption sites for the palladium complexes (without the need for prior sensitization by SnCl 2) during the electroless plating of copper, but also as an adhesion promotion layer to enhance the adhesion of the electrolessly deposited copper to the PTFE surfaces. The T-peel adhesion strength of the electrolessly deposited copper to the PVP grafted PTFE (PTFE-g-PVP) surface could reach about 7.2 N/cm. This adhesion strength was much higher than that of the electrolessly deposited copper to the pristine or Na /naphtha-treated PTFE surface. Effects of the graft polymerization time and the activation time in the PdCl 2 solution on the T-peel adhesion strength of the electrolessly deposited copper (from the Sn -free process) to the PTFE-g-PVP surface were determined.
INFLUENCE OF THE TECHNICAL PARAMETERS ON BIOACTIVE FILMS DEPOSITED BY PULSED LASER
Authors: ZHAO YAFAN , CHEN CHUANZHONG , SONG MINGDA , LIU JIAN
Published: July 2007

Pulsed laser deposition (PLD), which is a novel technique in producing thin films in the recent years, shows unique advantages for the deposition of bioactive films. Research states of the technical parameters of the pulsed laser deposited bioactive films, including substrate temperature, atmosphere pressure, energy density, wavelength, post-annealing, target, deposition rate, and thickness of the films, are systematically reviewed. Processing-microstructure-property relationships of bioactive films by pulsed laser deposition are discussed. The application prospect is pointed as well.
PEPTIDE NANOFILAMENTS USED FOR REPLICA-MOLDING: A COMBINATION OF "BOTTOM-UP" AND "TOP-DOWN"
Authors: TANG YUZHAO , ZHANG XIAODONG , SUN JIELIN , HU JUN , ZHANG FENG , HE JIANHUA
Published: July 2007

A novel nanofabrication method that combines both "bottom-up" (template-assisted peptide self-assembling) and "top-down" (replica molding) techniques is introduced. A designer peptide, GAV-9 (NH2-VGGAVVAGV-CONH2), can epitaxially self-assemble into nanofilaments on the surface of mica, which is further used as the diversified masters for the application of replica molding. With in situ atomic force microscopy monitoring, several typical masters are fabricated by peptide self-assembling on the surface of mica. These masters can be easily molded into hard poly(dimethylsiloxane) surfaces, and then further replica-molded into polyurethane surfaces. The polymeric surfaces with regular 1D and 2D patterns on the nanometer scale are expected to have new applications in nanostructure's fabrication.
CLUSTER-BASED EXTENSION OF THE GENERALIZED POISSON LOSS DYNAMICS AND CONSISTENCY WITH SINGLE NAMES
Authors: BRIGO DAMIANO , PALLAVICINI ANDREA , TORRESETTI ROBERTO
Published: July 2007

We extend the common Poisson shock framework reviewed for example in Lindskog and McNeil [15] to a formulation avoiding repeated defaults, thus obtaining a model that can account consistently for single name default dynamics, cluster default dynamics and default counting process. This approach allows one to introduce significant dynamics, improving on the standard "bottom-up" approaches, and to achieve true consistency with single names, improving on most "top-down" loss models. Furthermore, the resulting GPCL model has important links with the previous GPL dynamical loss model in Brigo et al. [6], which we point out. Model extensions allowing for more articulated spread and recovery dynamics are hinted at. Calibration to both DJi-TRAXX and CDX index and tranche data across attachments and maturities shows that the GPCL model has the same calibration power as the GPL model while allowing for consistency with single names.
ON THE TERM STRUCTURE OF LOSS DISTRIBUTIONS: A FORWARD MODEL APPROACH
Authors: SIDENIUS JAKOB
Published: July 2007

We define forward copula models and introduce the concept of "chaining" such models. We discuss the use of these concepts in the calibration to the term structure of tranche quotes.
EMPIRICAL COPULAS FOR CDO TRANCHE PRICING USING RELATIVE ENTROPY
Authors: DEMPSTER MICHAEL A. H. , MEDOVA ELENA A. , YANG SEUNG W.
Published: July 2007

We discuss the general optimization problem of choosing a copula with minimum entropy relative to a specified copula and a computationally intensive procedure to solve its dual. These techniques are applied to constructing an empirical copula for CDO tranche pricing. The empirical copula is chosen to be as close as possible to the industry standard Gaussian copula while ensuring a close fit to market tranche quotes. We find that the empirical copula performs noticeably better than the base correlation approach in pricing non-standard tranches and that the market view of default dependence is influenced by maturity.
Agency Costs of Controlling Shareholders' Share Collateral with Taiwan Evidence
Authors: Chen Anlin , Kao Lanfeng , Chen Yi-Kai
Published: July 2007

Controlling shareholders' share collateral is a new source of the deviation of cash flow rights and control rights leading to minority shareholder expropriation. However, controlling shareholders' share collateral is not forbidden and has not received particular restriction leading to its popularity in the capital markets. Neglecting the potential agency costs resulting from controlling shareholders' share collateral would hurt the interests of creditors and minority shareholders. We need legal regulation on controlling shareholders' share collateral to reinforce corporate governance mechanism to protect the interests of creditors and minority shareholders.
Calendar Spread Trading and the Efficiency of Australian Bank Accepted Bill Futures Market
Authors: Anderson John A. , Li Steven
Published: July 2007

This paper is concerned with the potential profit opportunities in trading calendar spreads of 90-day Bank Accepted Bill (BAB) futures contracts on the Sydney Futures Exchange (SFE) during the 1990s. It is shown that statistically significant gross profits can be generated by a naïve strategy for most of the considered holding periods ranging from 3 months to 18 months. However, after the deduction of generous transaction costs, the net profits are statistically significant only for the 6-month holding period returns. The implications of the profits produced by calendar spread trading methodology on the efficiency of the BAB futures market are also addressed. The empirical results reveal that the efficiency market hypothesis for the BAB futures market cannot be universally accepted in the 1990s.
The Jump Behavior of Foreign Exchange Market: Analysis of Thai Baht
Authors: Chang Jow-Ran , Hung Mao-Wei , Lee Cheng-Few , Lu Hsin-Min
Published: July 2007

We use square root stochastic volatility with or without jump model to study the heteroskedasticity and jump behavior of the Thai Baht. Bayesian factor is used to evaluate the explanatory power of competing model. It turns out that the square root stochastic volatility model with independent jump in observation and state equations (SVIJ) has the best explanatory power to our sample. Using the estimation results of the SVIJ model, we are able to link the major events of the Asian financial crisis to the jump behavior of either volatility or observation.
COEXISTENCE OF SOCIAL NORMS BASED ON IN- AND OUT-GROUP INTERACTIONS
Authors: FENT THOMAS , GROEBER PATRICK , SCHWEITZER FRANK
Published: July 2007

The question how social norms can emerge from microscopic interactions between individuals is a key problem in social sciences to explain collective behavior. In this paper, we propose an agent-based model to show that randomly distributed social behavior by way of local interaction converges to a state with a multimodal distribution of behavior. This can be interpreted as a coexistence of different social norms, a result that goes beyond previous investigations. The model is discrete in time and space, behavior is characterized in a continuous state space. The adaptation of social behavior by each agent is based on attractive and repulsive forces caused by friendly and adversary relations among agents. The model is analyzed both analytically and by means of spatio-temporal computer simulations. It provides conditions under which we find convergence towards a single norm, coexistence of two opposing norms, and coexistence of a multitude of norms. For the latter case, we also show the evolution of the spatio-temporal distribution of behavior.
TOWARD A HARMONIOUS UNIFYING HYBRID MODEL FOR ANY EVOLVING COMPLEX NETWORKS
Authors: FANG JINQING , BI QIAO , LI YONG , LU XIN-BIAO , LIU QIANG
Published: July 2007

The current interest in complex networks is a part of a broader movement towards research on complex systems. Motivation of this work raises the two challenging questions: (i) Are real networks fundamentally random preferential attached without any deterministic attachment for both un-weighted and weighted networks? (ii) Is there a coherent physical idea and model for unifying the study of the formation mechanism of complex networks? To answer these questions, we propose a harmonious unifying hybrid preferential model (HUHPM) to a certain class of complex networks, which is controlled by a hybrid ratio, d/r, and study their behavior both numerically and analytically. As typical examples, we apply the concepts and method of the HUHPM to un-weighted scale-free networks proposed by Barabasi and Albert (BA), weighted evolving networks proposed by Barras, Bartholomew and Vespignani (BBV), and the traffic driven evolution (TDE) networks proposed by Wang et al., to get the so-called HUHPM-BA, HUHPM-BBV and HUHPM-TDE networks. All the findings of topological properties in the above three typical HUHPM networks give certain universal meaningful results which reveal some essential hybrid mechanisms for the formation of nontrivial scale-free and small-world networks.
POPULAR WAVELET MODELS
Authors: DEBNATH LOKENATH , NADARAJAH SARALEES
Published: July 2007

The modern approach for wavelets imposes a Bayesian prior model on the wavelet coefficients to capture the sparseness of the wavelet expansion. The idea is to build flexible probability models for the marginal posterior densities of the wavelet coefficients. In this note, we derive exact expressions for two popular models for the marginal posterior density. We also illustrate the superior performance of these models over the standard models for wavelet coefficients.
SEMANTIC BASED LEARNING OF SYNTAX IN AN AUTONOMOUS ROBOT
Authors: MCCLAIN MATTHEW , LEVINSON STEPHEN
Published: July 2007

It is the goal of the Language Acquisition Group at the University of Illinois at Urbana-Champaign (LAR-UIUC) to build a robot that is able to learn language as well as humans through embodied sensori-motor interaction with the physical world. This paper proposes cognitive structures to enable an autonomous robot to learn the syntax of two-word sentences using its understanding of lexical semantics. A production rule of syntax in Chomsky Normal Form will be explicitly represented using a hidden Markov Model. Results of robotic experiments show that these models can learn representations of syntax in this form and that they can be used to produce novel sentences.
A COGNITIVE MODEL OF IMITATIVE DEVELOPMENT IN HUMANS AND MACHINES
Authors: SHON AARON P. , STORZ JOSHUA J. , MELTZOFF ANDREW N. , RAO RAJESH P. N.
Published: July 2007

Several algorithms and models have recently been proposed for imitation learning in humans and robots. However, few proposals offer a framework for imitation learning in noisy stochastic environments where the imitator must learn and act under real-time performance constraints. We present a novel probabilistic framework for imitation learning in stochastic environments with unreliable sensors. Bayesian algorithms, based on Meltzoff and Moore's AIM hypothesis for action imitation, implement the core of an imitation learning framework. Our algorithms are computationally efficient, allowing real-time learning and imitation in an active stereo vision robotic head and on a humanoid robot. We present simulated and real-world robotics results demonstrating the viability of our approach. We conclude by advocating a research agenda that promotes interaction between cognitive and robotic studies of imitation.
Hypoxia-induced changes in the expression of rat hepatobiliary transporter genes
Authors: Fouassier Laura , Beaussier Marc , Schiffer Eduardo , Rey Colette , Barbu Véronique , Mergey Martine , Wendum Dominique , Callard Patrice , Scoazec Jean-Yves , Lasnier Elisabeth , Stieger Bruno , Lienhart André , Housset Chantal
Published: July 2007

Cholestatic disorders may arise from liver ischemia (e.g., in liver transplantation) through various mechanisms. We have examined the potential of hypoxia to induce changes in the expression of hepatobiliary transporter genes. In a model of arterial liver ischemia subsequent to complete arterial deprivation of the rat liver, the mRNA levels of VEGF, a hypoxia-inducible gene, were increased fivefold after 24 h. The pattern of VEGF-induced expression and ultrastructural changes, including swelling of the endoplasmic reticulum, indicated that hypoxia affected primarily cholangiocytes, but also hepatocytes, predominantly in the periportal area. Serum and bile analyses demonstrated liver dysfunction of cholestatic type with reduced bile acid biliary excretion. Fluorescence-labeled ursodeoxycholic acid used as a tracer displayed no regurgitation, eliminating bile leakage as a significant mechanism of cholestasis in this model. In liver tissue, a marked reduction in the mRNA levels of Na+-taurocholate-cotransporting polypeptide (Ntcp), bile salt export protein (Bsep), and multidrug resistance-associated protein 2 (Mrp2) and an increase in those of Cftr were detected before bile duct proliferation occurred. In cultured hepatocytes, a nontoxic hypoxic treatment caused a decrease in the mRNA and protein expression of Ntcp, Bsep, and Mrp2 and in the mRNA levels of nuclear factors involved in the transactivation of these genes, i.e., HNF4α, RXRα, and FXR. In bile duct preparations, hypoxic treatment elicited an increase in Cftr transcripts, along with a rise in cAMP, a major regulator of Cftr expression and function. In conclusion, hypoxia triggers a downregulation of hepatocellular transporters, which may contribute to cholestasis, whereas Cftr, which drives secretion in cholangiocytes, is upregulated.
Cerebral oxygen delivery by liposome-encapsulated hemoglobin: a positron-emission tomographic evaluation in a rat model of hemorrhagic shock
Authors: Awasthi Vibhudutta , Yee Seong-Hwan , Jerabek Paul , Goins Beth , Phillips William T.
Published: July 2007

Liposome-encapsulated Hb (LEH) is being developed as an artificially assembled, low-toxicity, and spatially isolated Hb-based oxygen carrier (HBOC). Standard methods of evaluating oxygen carriers are based on surrogate indicators of physiology in animal models of shock. Assessment of actual delivery of oxygen by HBOCs and resultant improvement in oxygen metabolism at the tissue level has been a technical challenge. In this work, we report our findings from15O-positron emission tomographic (15O-PET) evaluation of LEH in a rat model of 40% hypovolemic shock. In vitro studies showed that PEGylated LEH formulation containing ∼7.5% Hb and consisting of neutral lipids (distearoylphosphatidylcholine:cholesterol:α-tocopherol, 51.4:46.4:2.2) efficiently picks up15O-labeled oxygen gas. The final preparation of LEH contained 5% human serum albumin to provide oncotic pressure. Cerebral PET images of anesthetized rats inhaling15O-labeled O2gas showed efficient oxygen-carrying and delivery capacity of LEH formulation. From the PET images, we determined cerebral metabolic rate of oxygen (CMRO2) as a direct indicator of oxygen-carrying capacity of LEH as well as oxygen delivery and metabolism in rat brain. Compared with control fluids [saline and 5% human serum albumin (HSA)], LEH significantly improved CMR[Formula: see text] to ∼80% of baseline level. Saline and HSA resuscitation could not improve hypovolemia-induced decrease in CMR[Formula: see text]. On the other hand, resuscitation of shed blood was the most efficient in restoring oxygen metabolism. The results suggest that15O-PET technology can be successfully employed to evaluate potential oxygen carriers and blood substitutes and that LEH resuscitation in hemorrhage enhances oxygen delivery to the cerebral tissue and improves oxygen metabolism in brain.
Statistics of Midbrain Dopamine Neuron Spike Trains in the Awake Primate
Authors: Bayer Hannah M. , Lau Brian , Glimcher Paul W.
Published: July 2007

Work in behaving primates indicates that midbrain dopamine neurons encode a prediction error, the difference between an obtained reward and the reward expected. Studies of dopamine action potential timing in the alert and anesthetized rat indicate that dopamine neurons respond in tonic and phasic modes, a distinction that has been less well characterized in the primates. We used spike train models to examine the relationship between the tonic and burst modes of activity in dopamine neurons while monkeys were performing a reinforced visuo-saccadic movement task. We studied spiking activity during four task-related intervals; two of these were intervals during which no task-related events occurred, whereas two were periods marked by task-related phasic activity. We found that dopamine neuron spike trains during the intervals when no events occurred were well described as tonic. Action potentials appeared to be independent, to occur at low frequency, and to be almost equally well described by Gaussian and Poisson-like (gamma) processes. Unlike in the rat, interspike intervals as low as 20 ms were often observed during these presumptively tonic epochs. Having identified these periods of presumptively tonic activity, we were able to quantitatively define phasic modulations (both increases and decreases in activity) during the intervals in which task-related events occurred. This analysis revealed that the phasic modulations of these neurons include both bursting, as has been described previously, and pausing. Together bursts and pauses seemed to provide a continuous, although nonlinear, representation of the theoretically defined reward prediction error of reinforcement learning.
Educational Differences, Value of Children and Fertility Outcomes in Germany
Authors: Klein Thomas , Eckhard Jan
Published: July 2007

Referring to the dependence of income and occupational opportunities on education as well as to the lower compatibility between career and parenthood for women, educational differences of family foundation rates are being interpreted as an expression of different opportunity costs by many researchers (opportunity cost hypothesis). This hypothesis is discussed and analysed in this article for the German case drawing on the German Family Survey (Familiensurvey). The analysis considers two aspects of fertility motivation: on the one hand, it refers to educational level and the perceived value of children for (potential) parents; on the other, it examines the behavioural relevance of these fertility motivations. The empirical results from national representative longitudinal data question the opportunity cost hypothesis. Neither the perception of the incompatibility between career and motherhood nor its effect on the desire to become a parent are stronger for more highly educated women than for women with a lower formal educational level. Moreover, the article provides empirical evidence that the well-known educational differentiation of family formation rates is associated with child-related utility expectations, such as stimulation and affect.
The Value of Children in Palestine and Turkey
Authors: Klaus Daniela , Suckow Jana , Nauck Bernhard
Published: July 2007

Recent data on fertility rates indicate tremendous differences between Palestine and Turkey: whereas the total fertility rate has decreased remarkably over the last few decades in Turkey, a rather stable, high fertility rate can be observed for Palestine. This study applies a reconceptualization of the value of children approach to explain this difference. Analyses were performed using a sample of 249 Palestinian and 622 Turkish mothers from the 2002 international Value of Children study. In a first step, it is revealed that in Palestine children are more important for parents' comfort and social esteem than in Turkey, while only slight country differences are found with respect to children's affection value. This is in line with the study's hypotheses. However, in a second step, the country-specific value of children is proved to be of only very limited predictive power with regard to the birth of children of different parity, which contradicts the expectations. A more detailed analysis suggests that it is rational to follow cultural routines with respect to children in Palestine but not in Turkey.
Factors Facilitating Japanese Married Women Entering the Labour Force
Authors: Kumagai Fumie , Kato Akihiko
Published: July 2007

This article evaluates factors that facilitate Japanese married women's entrance into the labour force. Logistic multiple regression analyses of a national representative sample revealed six significant factors: Japanese married women eagerly seek employment outside the home who co-reside with their mother-in-law; whose youngest child is 0—10 years old; whose husband's annual income is low; whose husband is non-salaried; who reside in small communities; or who possess liberal attitudes towards traditional marital roles. Working outside the home is an effective strategy adopted by married women in traditional intergenerational families to reduce conflict with in-laws, particularly the mother-in-law. In future studies, the authors hope to analyse the event history of longitudinal data to pinpoint causes of labour force participation of Japanese married women across communities.
Sibling Relationships in Adulthood and Old Age
Authors: Lu Pau-Ching
Published: July 2007

Using data from a study of 1996 adults aged 20 and older in Taiwan, this study examines the changing pattern of sibling relationships in adulthood across the life span, including young adulthood, middle age and old age. This study provides evidence that sibling ties in general provide more help in the form of social companionship and emotional support, and less in instrumental support. Furthermore, sibling contact and sibling support both vary inversely with age. In comparison to people in young adulthood and middle age, older people have less contact with siblings, and they also receive less assistance from siblings. This present study shows that the hypothesis generated by the life course perspective for analysis of changes in sibling relationships across life span is not supported. The results show that brother—brother dyads tend to provide the most help, which is different from the findings in western society where women are kin keepers. Such difference illustrates how the family—kinship institution affects sibling relationships across different cultures. Social companionship with siblings is a significant predictor of actual support from siblings, irrespective of whether it is emotional or instrumental in form.
Application of the Spectral Methods of Microstructure Design to Continuous Fiber-reinforced Composites
Authors: Kalidindi Surya R. , Houskamp Joshua R.
Published: July 2007

A new mathematical framework called microstructure-sensitive design (MSD) has recently been developed to facilitate solutions to inverse problems in microstructure design, where the goal is to identify the complete set of relevant microstructures that are theoretically predicted to satisfy a set of designer-specified criteria on effective properties or performance. This methodology has been applied previously to a few design-related case studies, mainly involving polycrystalline metals. This article describes the first application of MSD methodology to customized design of continuous fiber-reinforced composites for specified combinations of performance criteria. The main contribution of this study is that it presents a novel but simple mathematical framework for the application of first-order MSD to the design problems involving continuous fiber-reinforced composites. In the examples presented in this article, elementary first-order theories spanning two length scales have been selected to obtain effective properties of continuous fiber-reinforced composite material systems. Having selected these first-order theories, the authors proceed to demonstrate the viability of applying the first-order MSD framework to design the case studies in continuous fiber-reinforced composites.
Transverse Cracking of M40J/PMR-II-50 Composites under Thermal—Mechanical Loading: Part I — Characterization of Main and Interaction Effects using Statistical Design of Experiments
Authors: Ju Jaehyung , Morgan Roger J. , Creasy Terry S. , Shin E. Eugene
Published: July 2007

In this study, a novel conduction heating-based thermal cycling apparatus combined with large deflection bending is developed and utilized to identify the critical controlling parameters for microcracking of [90/0]1s, M40J/ PMR-II-50 high modulus carbon fiber/polyimide composite laminate under synergistic environmental conditions. The synergistic test involves four controlling parameters namely, average in-plane mechanical strains (0 and 0.488%), thermal cycling temperature amplitudes (—196—23 °C and —196—250°C), number of thermal cycles (1 and 8), and heating rate (1 and 4°C/min). The 2k factorial design is used for the four factors to provide their quantitative primary and interaction effects on crack density with a minimum number of experiments. The experimental results indicate that the number of thermal cycles is the primary controlling factor (41%), while the thermal cycling temperature amplitude (25%) or the in-plane strain (22%) is the secondary factor. The number of thermal cycles also exhibits a significant interaction effect on the development of microcracks when it was combined with either the temperature amplitude of thermal cycling (7%) or mechanical in-plane strain (5%).
Water Absorption Behavior and Its Influence on Properties of GRP Pipe
Authors: Yao J. , Ziegmann G.
Published: July 2007

With the rapid development of glass-fiber reinforced plastic (GRP) pipes in civil infrastructure under different environments, it is essential to understand the fundamental mechanisms responsible for the pipe failure. However, research reports on water absorption behavior and its influence on the performance of GRP pipe are few in the literatures. This study provides test results of water diffusion in a GRP pipe wall and its influence on the properties of the pipe. When the environment is water, it attacks each component of the GRP pipe. In this study, the water absorption behavior of three different types of GRP pipe is recorded. One of them (UP-A pipe) presents near-Fickian behavior, the other two types of pipe behave like a two-stage diffusion. A model developed from Fick's law is used to predict the water diffusion process for the three pipes. The prediction agrees well with the experimental data for the UP-A specimen, while the same cannot be transferred to EP-A and UP-B specimens because of the abnormal non-Fickian process. The influence of moisture on flexural properties, interlaminar shear strength, and viscoelastic properties of a GRP pipe is also discussed.
Thermodynamics Properties and Isothermal Crystallization Kinetics of Carbon Black/Poly(ethylene terephthalate) Composites
Authors: Zhang G.Q. , Sun F. , Gao L.P. , Wang L.N. , Shao M. , Liu J.Q.
Published: July 2007

Thermal properties, crystallization behavior and isothermal crystallization kinetics of poly(ethylene terephthalate) (PET) composites filled with nanophase carbon black (CB) have been investigated by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and wide angle X-ray diffractometer (WAXD). Compared with neat PET, thermal properties of the composites are changed significantly. The crystallization temperature decreases from 393 to 373 K when CB content in the composites increases from 0 to 12.5 wt%, while thermal stability of the CB/PET systems is enhanced as increasing initial decomposing temperature (Td) by 9—11 K. Avrami exponents n are evaluated to be 2.1—2.6 for neat PET and the composites. Carbon black nanoparticles acting as nucleating agent in the composites accelerates the crystallization rate as the decreasing half-time of crystallization (t 1/2), and the crystallinity of the composites is improved largely by addition of CB. The present study reveals several aspects of CB/PET composites crystallization behavior which should be considered when designing future applications of developed CB-filled electrical conductive polymer.
Cure Monitoring and Internal Strain Measurement of 3-D Hybrid Braided Composites using Fiber Bragg Grating Sensor
Authors: Jung Kyungho , Jin Kang Tae
Published: July 2007

Curing behavior and internal strain of 3-D hybrid braided composites is studied using embedded fiber Bragg grating (FBG) sensors. Thermo-optic coefficients and photo-elastic constant of fabricated FBG sensors are experimentally determined. A seven-layered three-dimensional (3-D) braided preform is fabricated. S2 glass fiber is used as the main braiding yarn, and Kevlar fiber is inserted in the exterior surface layer in the axial direction. Several nylon fibers are braided together in order to replace the FBG sensors after braiding. FBG sensors are embedded along the curved braiding yarn as well as in the machine direction. An FBG-embedded 3-D braided composite is fabricated using the resin-transfer molding (RTM) process. During the cure process, the expansion and contraction caused by the matrix cure as well as temperature changes are monitored. Local dimensional changes are measured quantitatively using an FBG sensor system. The FBG sensor embedded along a curved braiding yarn exhibited a relatively small amount of shrinkage. By using embedded FBG sensors and surface-bonded electric strain gages, internal strains of the 3-D braided composite are measured during compressive and flexural tests, and the results show good agreement with each other.