bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased In Vivo Activation of Microglia and Astrocytes in the Brains of Mice Transgenic for an Infectious R5 Human Immunodeficiency Virus Type 1 Provirus and for CD4-Specific Expression of Human Cyclin T1 in Response to Stimulation by Lipopolysaccharides
Authors: Sun Jinglin , Zheng Jian Hua , Zhao Mengliang , Lee Sunhee , Goldstein Harris
Published: March 2008

Inflammatory mediators and viral products produced by human immunodeficiency virus (HIV)-infected microglia and astrocytes perturb the function and viability of adjacent uninfected neuronal and glial cells and contribute to the pathogenesis of HIV-associated neurocognitive disorders (HAND). In vivo exposure to lipopolysaccharide (LPS) activates parenchymal microglia and astrocytes and induces cytokine and chemokine production in the brain. HIV-infected individuals display increased circulating LPS levels due to microbial translocation across a compromised mucosa barrier. We hypothesized that HIV-infected microglia and astrocytes display increased sensitivity to the proinflammatory effects of LPS, and this combines with the increased levels of systemic LPS in HIV-infected individuals to contribute to the development of HAND. To examine this possibility, we determined the in vivo responsiveness of HIV-infected microglia and astrocytes to LPS using our mouse model, JR-CSF/human cyclin T1 (JR-CSF/hu-cycT1) mice, which are transgenic for both an integrated full-length infectious HIV type 1 (HIV-1) provirus derived from the primary R5-tropic clinical isolate HIV-1JR-CSFregulated by the endogenous HIV-1 long terminal repeat and the hu-cycT1 gene under the control of a CD4 promoter. In the current report, we demonstrated that in vivo-administered LPS more potently activated JR-CSF/hu-cycT1 mouse microglia and astrocytes and induced a significantly higher degree of monocyte chemoattractant protein production by JR-CSF/hu-cycT1 astrocytes compared to that of the in vivo LPS response of control littermate mouse microglia and astrocytes. These results indicate that HIV infection increases the sensitivity of microglia and astrocytes to inflammatory stimulation and support the use of these mice as a model to investigate various aspects of the in vivo mechanism of HIV-induced neuronal dysfunction.
Coreceptor Tropism Can Be Influenced by Amino Acid Substitutions in the gp41 Transmembrane Subunit of Human Immunodeficiency Virus Type 1 Envelope Protein
Authors: Huang Wei , Toma Jonathan , Fransen Signe , Stawiski Eric , Reeves Jacqueline D. , Whitcomb Jeannette M. , Parkin Neil , Petropoulos Christos J.
Published: March 2008

Many studies have demonstrated that the third variable region (V3) of the human immunodeficiency virus type 1 (HIV-1) envelope protein (Env) is a major determinant of coreceptor tropism. Other regions in the surface gp120 subunit of Env can modulate coreceptor tropism in a manner that is not fully understood. In this study, we evaluated the effect of
env
determinants outside of V3 on coreceptor usage through the analysis of (i) patient-derived
env
clones that differ in coreceptor tropism, (ii) chimeric
env
sequences, and (iii) site-directed mutants. The introduction of distinct V3 sequences from CXCR4-using clones into an R5-tropic
env
backbone conferred the inefficient use of CXCR4 in some but not all cases. Conversely, in many cases, X4- and dual-tropic
env
backbones containing the V3 sequences of R5-tropic clones retained the ability to use CXCR4, suggesting that sequences outside of the V3 regions of these CXCR4-using clones were responsible for CXCR4 use. The determinants of CXCR4 use in a set of dual-tropic
env
sequences with V3 sequences identical to those of R5-tropic clones mapped to the gp41 transmembrane (TM) subunit. In one case, a single-amino-acid substitution in the fusion peptide of TM was able to confer CXCR4 use; however, TM substitutions associated with CXCR4 use varied among different
env
sequences. These results demonstrate that sequences in TM can modulate coreceptor specificity and that
env
sequences other than that of V3 may facilitate efficient CXCR4-mediated entry. We hypothesize that the latter plays an important role in the transition from CCR5 to CXCR4 coreceptor use.
Homologous Recombination Is Very Rare or Absent in Human Influenza A Virus
Authors: Boni Maciej F. , Zhou Yang , Taubenberger Jeffery K. , Holmes Edward C.
Published: March 2008

To determine the extent of homologous recombination in human influenza A virus, we assembled a data set of 13,852 sequences representing all eight segments and both major circulating subtypes, H3N2 and H1N1. Using an exhaustive search and a nonparametric test for mosaic structure, we identified 315 sequences (∼2%) in five different RNA segments that, after a multiple-comparison correction, had statistically significant mosaic signals compatible with homologous recombination. Of these, only two contained recombinant regions of sufficient length (>100 nucleotides [nt]) that the occurrence of homologous recombination could be verified using phylogenetic methods, with the rest involving very short sequence regions (15 to 30 nt). Although this secondary analysis revealed patterns of phylogenetic incongruence compatible with the action of recombination, neither candidate recombinant was strongly supported. Given our inability to exclude the occurrence of mixed infection and template switching during amplification, laboratory artifacts provide an alternative and likely explanation for the occurrence of phylogenetic incongruence in these two cases. We therefore conclude that, if it occurs at all, homologous recombination plays only a very minor role in the evolution of human influenza A virus.
Nuclear Localization Sequences in Cytomegalovirus Capsid Assembly Proteins (UL80 Proteins) Are Required for Virus Production: Inactivating NLS1, NLS2, or Both Affects Replication to Strikingly Different Extents
Authors: Nguyen Nang L. , Loveland Amy N. , Gibson Wade
Published: March 2008

Scaffolding proteins of spherical prokaryotic and eukaryotic viruses have critical roles in capsid assembly. The primary scaffolding components of cytomegalovirus, called the assembly protein precursor (pAP, pUL80.5) and the maturational protease precursor (pPR, pUL80a), contain two nuclear localization sequences (NLS1 and NLS2), at least one of which is required in coexpression experiments to translocate the major capsid protein (MCP, pUL85) into the nucleus. In the work reported here, we have mutated NLS1 and NLS2, individually or together, in human cytomegalovirus (HCMV, strain AD169) bacmid-derived viruses to test their effects on virus replication. Consistent with results from earlier transfection/coexpression experiments, both single-mutant bacmids gave rise to infectious virus but the double mutant did not. In comparisons with the wild-type virus, both mutants showed slower cell-to-cell spread; decreased yields of infectious virus (3-fold lower for NLS1
−
and 140-fold lower for NLS2
−
); reduced efficiency of pAP, pPR, and MCP nuclear translocation (sixfold lower for NLS1
−
and eightfold lower for NLS2
−
); increased amounts of a 120-kDa MCP fragment; and reduced numbers of intranuclear capsids. All effects were more severe for the NLS2
−
mutant than the NLS1
−
mutant, and a distinguishing feature of cells infected with the NLS2
−
mutant was the accumulation of large, UL80 protein-containing structures within the nucleus. We conclude that these NLS assist in the nuclear translocation of MCP during HCMV replication and that NLS2, which is unique to the betaherpesvirus UL80 homologs, may have additional involvements during replication.
Molecular cloning and mapping of casein kinase 2 alpha and beta subunit genes in barley
Authors: Kato K. , Kidou S. , Miura H.
Published: March 2008

Casein kinase 2 (CK2) is a ubiquitous, highly pleiotropic, constitutively active, and messenger-independent Ser/Thr protein kinase. It is found in two different forms: the heterotetrameric CK2, composed of two alpha catalytic subunits and two beta regulatory subunits, and the monomeric CK2 alpha, consisting of the alpha catalytic subunit. In the present study, we isolated barley cDNA clones of the CK2 alpha and beta subunit genes, designated HvCK2A and HvCK2B, respectively. Chromosome assignment, using a set of wheat–barley disomic chromosome addition lines, and RFLP mapping, using two doubled haploid populations, showed that HvCK2A was duplicated on the short arm of chromosome 2H and the long arm of chromosome 5H (designated HvCK2a-2H and HvCK2a-5H, respectively), and a single copy of HvCK2B was located on the long arm of chromosome 1H (designated HvCK2b). A PCR-Southern hybridization experiment demonstrated that the HvCK2A sequence originated from the HvCK2a-5H locus, showing that at least HvCK2a-5H was expressed. The present cDNA sequences and genomic organization of the two subunits will facilitate further functional analysis of CK2 in barley.
Divergent patterns of allelic diversity from similar origins: the case of oilseed rape (Brassica napusL.) in China and Australia
Authors: Chen S. , Nelson M. N. , Ghamkhar K. , Fu T. , Cowling W. A.
Published: March 2008

Oilseed rape ( Brassica napus ) in Australia and China have similar origins, with introductions from Europe, Canada, and Japan in the mid 20th century, and there has been some interchange of germplasm between China and Australia since that time. Allelic diversity of 72 B. napus genotypes representing contemporary germplasm in Australia and China, including samples from India, Europe, and Canada, was characterized by 55 polymorphic simple sequence repeat (SSR) markers spanning the entire B. napus genome. Hierarchical clustering and two-dimensional multidimensional scaling identified a Chinese group (China-1) that was separated from a “mixed” group of Australian, Chinese (China-2), European, and Canadian lines. A small group from India was distinctly separated from all other B. napus genotypes. Chinese genotypes, especially in the China-1 group, have inherited unique alleles from interspecific crossing, primarily with B. rapa, and the China-2 group has many alleles in common with Australian genotypes. The concept of “private alleles” is introduced to describe both the greater genetic diversity and the genetic distinctiveness of Chinese germplasm, compared with Australian germplasm, after 50 years of breeding from similar origins.
The first linkage map of the plant-pathogenic basidiomyceteTyphula ishikariensis
Authors: Chang S. W. , Jung G.
Published: March 2008

Speckled snow mold, caused by the basidiomycete Typhula ishikariensis Imai, is one of the most prominent winter diseases on perennial grasses and cereal crops in the northern hemisphere. The first linkage map of T. ishikariensis was constructed using a population of 93 sibling monokaryons derived from a single dikaryotic hybrid isolate that was created by a hyphal fusion of two monokaryotic parental isolates. The parental isolates were produced from a pathogenic dikaryotic isolate collected from a golf course in Wisconsin. The two parents exhibit significant differences in the production of aerial mycelium and sclerotia, and in their aggressiveness on creeping bentgrass ( Agrostis stolonifera L.). A total of 251 loci were mapped, comprising 89 inter-simple sequence repeat (ISSR) and 160 random amplified polymorphic DNA (RAPD) markers along with 2 phenotype-based mating-type (MAT) loci. The MAT loci were mapped on linkage groups (LGs) 1 and 7. The markers were evenly distributed over 7 LGs, covering 436 cM with an average marker interval of 2.2 cM. Seven chromosomes were cytologically observed using germ tube bursting methods with acetocarmine staining. This reference linkage map of T. ishikariensis should provide a framework for the mapping of quantitatively controlled traits such as fungal growth, survival, and virulence/avirulence under low temperatures. The map should also be utilized for studying the genome organization of the cold-loving plant-pathogenic Typhula spp. and for comparative genome analysis among fungal taxa.
Phylogenetic determination of the pace of transposable element proliferation in plants:copiaand LINE-like elements inGossypium
Authors: Hawkins Jennifer S. , Hu Guanjing , Rapp Ryan A. , Grafenberg Jessie L. , Wendel Jonathan F.
Published: March 2008

Transposable elements contribute significantly to plant genome evolution in myriad ways, ranging from local insertional mutations to global effects exerted on genome size through accumulation. Differential accumulation and deletion of transposable elements may profoundly affect genome size, even among members of the same genus. One example is that of Gossypium (cotton), where much of the 3-fold genome size variation is due to differential accumulation of one gypsy-like LTR retrotransposon, Gorge3. Copia and non-LTR LINE retrotransposons are also major components of the Gossypium genome, but unlike Gorge3, their extant copy numbers do not correlate with genome size. In the present study, we describe the nature and timing of transposition for copia and LINE retrotransposons in Gossypium. Our findings indicate that copia retrotransposons have been active in each lineage since divergence from a common ancestor, and that they have proliferated in a punctuated manner. However, the evolutionary history of LINEs contrasts markedly with that of the copia retrotransposons. Although LINEs have also been active in each lineage, they have accumulated in a stochastically regular manner, and phylogenetic analysis suggests that extant LINE populations in Gossypium are dominated by ancient insertions. Interestingly, the magnitude of transpositional bursts in each lineage corresponds directly with extant estimated copy number.
The development of a bin mapping population and the selective mapping of 103 markers in the diploidFragariareference map
Authors: Sargent D. J. , Cipriani G. , Vilanova S. , Gil-Ariza D. , Arús P. , Simpson D. W. , Tobutt K.R. , Monfort A.
Published: March 2008

We have identified a set of plants (the bin set) to permit “selective” or “bin” mapping using the diploid strawberry mapping population FV × FN, derived from the F2cross F. vesca 815 × F. nubicola 601, which has been used to develop the Fragaria reference map. The bin set consists of 8 plants: the F. vesca 815 parent, the F1hybrid individual, and 6 seedlings of the F2population. This bin set divides the 578 cM of the diploid Fragaria genome into 46 bins, the largest mapping bin being 26 cM in length and the average bin size being 12.6 cM. To validate the FV × FN bin set, we used it to locate 103 loci into bins on the FV × FN map. These loci comprised 61 previously described SSRs, 38 new SSRs developed in this investigation from Fragaria × ananassa genomic DNA, EST and gene sequences, and 4 ripening-related genes developed for Prunus . The 103 markers were located to bins on all 7 linkage groups of the Fragaria map and a new mapping bin was identified with the novel markers, demonstrating that the map covers the majority of the diploid Fragaria genome and that the 6 bin-set seedlings selected were appropriate for bin mapping using this progeny.
Large genomes among caridean shrimp
Authors: Rees David J. , Belzile Claude , Glémet Hélène , Dufresne France
Published: March 2008

Recent genome size estimates for Arctic amphipods have revealed the largest genomes known in the Crustacea. Here we provide additional data for 7 species of caridean shrimp collected from the Canadian Arctic and the Gulf of St. Lawrence. Genome sizes were estimated by flow cytometry and haploid C-values ranged from 8.53 ± 0.30 pg in Pandalus montagui (Pandalidae) to 40.89 ± 1.23 pg in Sclerocrangon ferox (Crangonidae). The value for S. ferox represents the largest decapod genome yet recorded and indicates a 38-fold variation in genome size within this order. These data suggest that large genomes may be relatively common in Arctic crustaceans, and underline the need for further comparative studies.
CHARGED AND NEUTRAL CURRENTS IN A 3-3-1 MODEL WITH RIGHT-HANDED NEUTRINOS
Authors: PALCU ADRIAN
Published: March 2008

The charged and the neutral currents are obtained by using a formal algebraical approach (developed and applied by the author) within the exact solution of a 3-3-1 gauge model with right-handed neutrinos. The entire Standard Model phenomenology is recovered without imposing any supplemental condition, but only by choosing an adequate set of parameters from the very beginning of the calculus. A new and rich phenomenology regarding the particles and their currents occurs as well. The appealing feature of our results resides in the exact expressions of the currents which need not the adjustment usually due to the small mixing angle ϕ between neutral bosons Z and Z′ (like in most of the papers in the literature treating the same issue). The required mixing was considered and already performed as an intermediate step by the solving method itself, since the physical eigenstates of those bosons were determined and then identified in the neutral currents.
HIGGS MECHANISM IN A LIGHT FRONT FORMULATION
Authors: MARTINOVIČ LUBOMÍR , GRANGÉ PIERRE
Published: March 2008

We give a simple derivation of the Higgs phenomenon in an Abelian light front gauge theory. It is based on a finite-volume quantization with antiperiodic scalar fields and periodic gauge field. An infinite set of degenerate vacua in the form of coherent states of the scalar field, that minimize the light front energy, is constructed. The corresponding effective Hamiltonian describes a massive vector field whose third component is generated by the would-be Goldstone boson. This mechanism, understood here quantum mechanically in the form analogous to the spacelike quantization, is derived without gauge fixing as well as in the unitary and the light-cone gauge.
INTEGRATED FIELD EQUATIONS OF HETEROTIC SUPERGRAVITIES
Authors: YILMAZ NEJAT T.
Published: March 2008

The first-order bosonic field equations of the D-dimensional effective low energy theory which describes the massless background coupling of the D-dimensional fully Higgsed heterotic string are derived.
ALTERNATIVE VARIABLES FOR THE DYNAMICS OF GENERAL RELATIVITY
Authors: ROSAS-RODRÍGUEZ R.
Published: March 2008

A new form of the dynamical equations of vacuum general relativity is proposed. This form involves the canonical Hamiltonian structure but noncanonical variables. The new field variables are the electric field [Formula: see text] and the magnetic field [Formula: see text] which emerge from the Ashtekar's representation for canonical gravity. The constraint algebra is studied in terms of the new field variables and the counting of the degrees of freedom is done. The quantization is briefly outlined.
AN EXACT BIANCHI TYPE-I COSMOLOGICAL MODEL IN LYRA'S MANIFOLD
Authors: KUMAR SURESH , SINGH C. P.
Published: March 2008

A spatially homogeneous and anisotropic Bianchi type-I space–time has been studied within the framework of Lyra's geometry. Exact solutions of the Einstein's field equations have been obtained with a time dependent gauge function by using a special law of variation for Hubble's parameter that yields a constant value of deceleration parameter. It has been found that the solutions generalize the solutions obtained by Rahaman et al. [Astrophys. Space Sci.299, 211 (2005)] and are consistent with the recent observations of type Ia supernovae. A detailed study of physical and kinematical properties of the model has been carried out.
A CHIRAL SCHWINGER MODEL, ITS CONSTRAINT STRUCTURE AND APPLICATIONS TO ITS QUANTIZATION
Authors: BRACKEN PAUL
Published: March 2008

The Jackiw–Rajaraman version of the chiral Schwinger model is studied as a function of the renormalization parameter. The constraints are obtained and they are used to carry out canonical quantization of the model by means of Dirac brackets. By introducing an additional scalar field, it is shown that the model can be made gauge invariant. The gauge invariant model is quantized by establishing a pair of gauge fixing constraints in order that the method of Dirac can be used.
ROLE OF EXTRA DIMENSION IN ACCELERATED EXPANSION
Authors: PUROHIT K. D. , BHATT YOGESH
Published: March 2008

A five-dimensional FRW-type Kaluza–Klein cosmological model is taken to study the role of extra dimension in the expansion of the universe. Relation between scale factors corresponding to conventional four dimensions and the extra dimension has been established. Field equations are solved in order to find out the effect of pressure corresponding to these scale factors. Conditions for accelerated expansion are derived.
INFLUENCE OF WAITING TIME ON THE LEVITATION FORCE BETWEEN A PERMANENT MAGNET AND A SUPERCONDUCTOR
Authors: ZHANG XING-YI , ZHOU YOU-HE , ZHOU JUN
Published: March 2008

This paper describes the experimental results of the levitation force of single-grained YBaCuO bulk superconductors preparing by the top-seeded melt-growth method with different waiting time tw below an NdFeB permanent magnet. It was found that waiting time has large effects on the zero-field-cooled (ZFC) and field-cooled (FC) levitation force, and the levitation force shows aging characteristics at the liquid nitrogen temperature.
ALGORITHMS FOR FRACTAL DIMENSION CALCULATION
Authors: SHANKER O.
Published: March 2008

Algorithms to calculate the fractal dimension of a complex network are presented. One of the algorithms is applied to a parametrized class of models whose fractal dimension transitions from one to two. For the system size we considered here (16384 nodes), the transition takes place from one at p = 0 to essentially two at the small value p = 0.03. This seems to indicate that the transition is likely to become infinitely sharp and occur at p = 0 as the system size increases to infinity.
OPERATION FOR A NEW KIND OF FUZZY GENETIC ALGORITHM BASED ON THE TRANSFORMATION OF THE PRINCIPLE INDEX
Authors: LI FA-CHAO , JIN CHEN-XIA , YUE PAN-XIANG
Published: March 2008

By using the restricted and complementary relationship of the principle and secondary indexes, providing the description of the compound quantification of the fuzzy number, and analyzing the essential characteristic of fuzzy decision, we propose a kind of fuzzy genetic algorithm based on the principle index (PO-FGA for short) to deal with the fuzzy optimization and programming problems with fuzzy coefficients, fuzzy variables and fuzzy constraints. The concrete solution method is presented in accordance with the strategy of the unconditional penality transformation with conditional constrains. Then consider its convergence by using Markov chain theory and analyze its performance through two examples. All these indicate that this kind of algorithm is of faster speed of convergence, smaller number of iterations, has lower chances of trapping into the state of premature convergence and can be widely used in many problems of optimization.
AUTO ADAPTED ENGLISH PRONUNCIATION EVALUATION: A FUZZY INTEGRAL APPROACH
Authors: CHEN QINGCAI , WANG XIAOLONG , SU PENGFEI , YAO YI
Published: March 2008

To evaluate the pronunciation skills of spoken English is one of the key tasks for computer-aided spoken language learning (CALL). While most of the researchers focus on improving the speech recognition techniques to build a reliable evaluation system, another important aspect of this task has been ignored, i.e. the pronunciation evaluation model that integrates both the reliabilities of existing speech processing systems and the learner's pronunciation personalities. To take this aspect into consideration, a Sugeno integral-based evaluation model is introduced in this paper. At first, the English phonemes that are hard to be distinguished (HDP) for Chinese language learners are grouped into different HDP sets. Then, the system reliabilities for distinguishing the phonemes within a HDP set are computed from the standard speech corpus and are integrated with the phoneme recognition results under the Sugeno integral framework. The fuzzy measures are given for each subset of speech segments that contains n occurrences of phonemes within a HDP set. Rather than providing a quantity of scores, the linguistic descriptions of evaluation results are given by the model, which is more helpful for the users to improve their spoken language skills. To get a better performance, generic algorithm (GA)-based parameter optimization is also applied to optimize the model parameters. Experiments are conducted on the Sphinx-4 speech recognition platform. They show that, with 84.7% of average recognition rate of the SR system on standard speech corpus, our pronunciation evaluation model has got reasonable and reliable results for three kinds of test corpora.
A STRATEGY FOR SECURING APDU TRANSMISSION
Authors: LIU MING-SHENG , LIU HUI , ZHENG JIAN-WU
Published: March 2008

The smart card is being used all over the world, because of its power to store data securely and execute calculations confidentially. This paper proposes an easy way to implement the strategy which can guarantee data integrity and privacy in the transmission path between the terminal application of the smart card and the smart card. This strategy consists of cryptographic functions of message and methods for transmitting APDU and managing secret keys. Some cryptographic functions of message are defined and developed for transmitting APDU confidentially. These cryptographic functions can keep the byte length of input and output messages identical. This strategy for transmitting APDU points out how to call cryptographic functions to encode or decode the data body of APDU, and how to construct a modified APDU message structure according to the original APDU message structure, which will be sent to its intended recipient instead of the original APDU message structure. With the proper secret keys, the authorized party can recover this modified APDU to its corresponding original APDU properly, without any information leakage. The transfer of secret keys to other parties is the most difficult aspect of secure APDU transmission, whereas data encryption/decryption is relatively straightforward. Two distinct strategies for managing secret keys, namely the static and the dynamic are introduced and compared. The dynamic strategy is preferred for a terminal application and smart card which do not need to authenticate each other. The implementation of this dynamic strategy has been detailed.
FAST FUZZY MULTICATEGORY SVM BASED ON SUPPORT VECTOR DOMAIN DESCRIPTION
Authors: WANG XI-ZHAO , LU SHU-XIA , ZHAI JUN-HAI
Published: March 2008

This paper proposes a fast fuzzy classifier of multicategory support vector machines (FMSVM) based on support vector domain description (SVDD). The main idea is that the proposed FMSVM is obtained by directly considering all data in one optimization formulation, using a fuzzy membership to each input point. The fuzzy membership is determined by support vector domain description (SVDD). For making support vector machine (SVM) more practical, we use an implement of the modified sequential minimal optimization (SMO) that can quickly solve SVM quadratic programming (QP) problems without any extra matrix storage or the use of numerical QP optimization steps at all. Compared with the existing SVMs, the newly proposed FMSVM that uses the L2-norm in the objective function shows improvement with regards to accuracy of classification and reduction of the effects of noises and outliers. The experiment also shows the efficiency of the modified SMO for expediting the training of SVM.
THE LOCALIZED GENERALIZATION ERROR MODEL FOR SINGLE LAYER PERCEPTRON NEURAL NETWORK AND SIGMOID SUPPORT VECTOR MACHINE
Authors: NG WING W. Y. , YEUNG DANIEL S. , TSANG ERIC C. C.
Published: March 2008

We had developed the localized generalization error model for supervised learning with minimization of Mean Square Error. In this work, we extend the error model to Single Layer Perceptron Neural Network (SLPNN) and Support Vector Machine (SVM) with sigmoid kernel function. For a trained SLPNN or SVM and a given training dataset, the proposed error model bounds above the error for unseen samples which are similar to the training samples. As the major component of the localized generalization error model, the stochastic sensitivity measure formula for perceptron neural network derived in this work has relaxed the assumptions of same distribution for all inputs and each sample perturbed only once in previous works. These make the sensitivity measure applicable to pattern classification problems. The stochastic sensitivity measure of SVM with Sigmoid kernel is also derived in this work as a component of the localized generalization error model. At the end of this paper, we discuss the advantages of the proposed error bound over existing error bound.
ON THE AUTOMORPHISM GROUP OF A FREE METABELIAN LIE ALGEBRA
Authors: ROMAN'KOV VITALY
Published: March 2008

Let K be a field of any characteristic. We prove that a free metabelian Lie algebra M3of rank 3 over K admits wild automorphisms. Moreover, the subgroup I Aut M3of all automorphisms identical modulo the derived subalgebra [Formula: see text] cannot be generated by any finite set of IA-automorphisms together with the sets of all inner and all tame IA-automorphisms. In the case if K is finite the group Aut M3cannot be generated by any finite set of automorphisms together with the sets of all tame, all inner automorphisms and all one-row automorphisms. We present an infinite set of wild IA-automorphisms of M3which generates a free subgroup F∞modulo normal subgroup generated by all tame, all inner and all one-row automorphisms of M3.
THE FOX PROBLEM FOR FREE RESTRICTED LIE ALGEBRAS
Authors: USEFI HAMID
Published: March 2008

Let L be a free restricted Lie algebra and R a restricted ideal of L. Denote by u(L) the restricted enveloping algebra of L and by ω(L) the associative ideal of u(L) generated by L. The purpose of this paper is to identify the subalgebra R ∩ ωn(L)ω(R) in terms of R only. This problem is the analogue of the Fox problem for free groups.
POSET REPRESENTATIONS OF DISTRIBUTIVE SEMILATTICES
Authors: WEHRUNG FRIEDRICH
Published: March 2008

We prove that for every distributive 〈∨,0〉-semilattice S, there are a meet-semilattice P with zero and a map μ: P × P → S such that μ(x,z) ≤ μ(x,y) ∨ μ(y,z) and x ≤ y implies that μ(x,y) = 0, for all x, y, z ∈ P, together with the following conditions:.

(P1) μ(v,u) = 0 implies that u = v, for all u ≤ v in P.

(P2) For all u ≤ v in P and all a, b ∈ S, if μ(v,u) ≤ a ∨ b, then there are a positive integer n and a decomposition u = x0 ≤ x1 ≤ ⋯ ≤ xn = v such that either μ(xi + 1, xi) ≤ a or μ(xi+1, xi) ≤ b, for each i < n.

(P3) The subset {μ(x,0) | x ∈ P} generates the semilattice S.

Furthermore, every finite, bounded subset of P has a join, and P is bounded in case S is bounded. Furthermore, the construction is functorial on lattice-indexed diagrams of finite distributive 〈∨,0,1〉-semilattices.
Three-Dimensional Micro-Actuator Fabrication by Aluminum Anodizing, Laser Irradiation, and Electrodepopsition
Authors: Kikuchi Tatsuya , Ueda Shingo , Akiyama Yoshiyuki , Ueda Mikito , Sakairi Masatoshi , Takahashi Hideaki
Published: March 2008

Three-dimensional micro-actuators, consisting of three-layer structure of acrylic acid resin / Au / polypyrrole, were fabricated by aluminum anodizing, laser irradiation, and electrochemical techniques. Anodized aluminum tube specimens were irradiated with a pulsed Nd-YAG laser to remove anodic oxide films, and then an Au layer was deposited at the area where film had been removed. The subsequent electrophoretic deposition of acrylic acid resin on the Au layer, dissolution of anodic oxide film and the metal substrate, and deposition of polypyrrole on backside of Au layer by electro-polymerization enabled the fabrication of a three-layer actuator. Cyclic voltammetry of the actuator showed that redox reactions of polypyrrole are accompanied with doping and dedoping of hydrated cations. The three-dimensional micro-actuator showed good performance as a manipulator, gripping and moving objects of several mg in solutions.
Artificial Pit Studies of Anodic Dissolution Kinetics in Localised Corrosion of Aluminium
Authors: Soltis Jozef , Laycock Nick , Cook Anthony , Krouse Donal , White Stephen
Published: March 2008

A series of experiments were conducted to study anodic dissolution kinetics and pit morphology using 0.025 mm and 1 mm thick 99.99% Al wires, respectively. There is a strong dependence of the potentials associated with noise-cessation and pit repassivation on increasing concentration of HCl in the bulk electrolyte. The potential regions dominated by noiseless current signatures were likely associated with the salt-free surface of a given pit during the dissolution process. Change in pit anode resistance, Rp, with applied potential was assigned to the dependence of the pit solution resistance on concentration, and the current oscillations observed were related to hydrogen evolution. Crystallographic pit propagation was observed for 1 mm artificial pits and for pitting sites developed during potentiodynamic scans.
Growth of Anodic Aluminum Oxide Films Without pH-Buffer
Authors: Lee Hochun , Isaacs Hugh S.
Published: March 2008

The anodic behavior of abraded pure Al in un-buffered solutions has been addressed using the cyclic voltammetry and the numerical modeling. In buffer solutions such as borate and phosphate, the Al oxidation current increases rapidly at first and then reaches a plateau region, which can be explained in terms of the high field conduction model and oxide dissolution. However, the anodic current in un-buffered solutions such as sulfate solution continues to increase with potential, which necessitates modification to the conventional high field conduction model. The behavior in un-buffered solutions has been ascribed to the increases in acidity at oxide/electrolyte interface as the anodization proceeds. By assuming that the oxide formation efficiency is diminishing with the degree of surface acidity, features of the anodic behavior in un-buffered solutions, absent in buffered solutions, were simulated.
Corrosion Reliability of Electronic Systems
Authors: Ambat Rajan , Jensen Stine G. , Mo̸ller Per
Published: March 2008

Inherently two factors namely multi-material usage and potential bias makes electronic devices susceptible to corrosion if exposed to humid conditions. The problem is compounded today due to miniaturization and contamination effects. The reduction in size of the components and close spacing on a Printed Circuit Board (PCB) for high density packing has greatly increased the risk of corrosion under humid conditions. An important issue is the failures due to electrolytic metal migration. This paper describes an investigation of the electrolytic migration of Sn-Pb solder lines on PCBs in humid environments under applied potential conditions. Studies were carried out using two electrode potentiostatic polarization experiments and measuring the resulting current due to electrolytic migration. The surface morphology of the electrodes before and after migration testing was investigates using SEM and EDS. An in-service failure of a Ceramic Capacitor due to electrolytic migration in humid environments is also presented.
Benzotriazole Influence on Copper Pitting Corrosion in Hydrocarbonate-Chloride Solutions under Different Temperature
Authors: Skrypnikova Ekaterina A. , Kaluzhina Svetlana , Bocharova Irina
Published: March 2008

It was found out that benzotiazole shows inhibitive properties for copper pitting corrosion at investigated hydrocarbonate- chloride systems at both room and elevated temperature. Simultaneously it was obtained concentration range for using the present inhibitor for full copper pitting corrosion suppression caused by Cl- - ions.
Composite Passive Layers of Ni(OH)2/Poly-(Neutral Red) on Nickel in a Weakly Acid Sulphate Medium Grown under Potentiodynamic Conditions
Authors: Vicente Francisco , Agrisuelas Jerónimo , Gabrielli Claude , García-Jareño José Juan J. , Giménez-Romero David , Perrot Hubert
Published: March 2008

Poly-(Neutral Red) has been deposited on the Ni(OH)2 passive layer in consonance with the semi-conducting character of this layer. EQCM result shows that polymer obtained under such conditions hinders to a great extend nickel electrodissolution process. There exist evidences for the formation of a composite Ni(OH)2/Poly-(Neutral Red) material. The instantaneous mass/charge ratio Fdm/dQ analysis allows to obtain information about active/passive transition and nickel transpassive dissolution mechanisms.
Prolactin stimulates transepithelial calcium transport and modulates paracellular permselectivity in Caco-2 monolayer: mediation by PKC and ROCK pathways
Authors: Thongon Narongrit , Nakkrasae La-iad , Thongbunchoo Jirawan , Krishnamra Nateetip , Charoenphandhu Narattaphol
Published: March 2008

Prolactin (PRL) was previously demonstrated to rapidly enhance calcium absorption in rat duodenum and the intestine-like Caco-2 monolayer. However, its mechanism was not completely understood. Here, we investigated nongenomic effects of PRL on the transepithelial calcium transport and paracellular permselectivity in the Caco-2 monolayer by Ussing chamber technique. PRL increased the transcellular and paracellular calcium fluxes and paracellular calcium permeability within 60 min after exposure but decreased the transepithelial resistance of the monolayer. The effects of PRL could not be inhibited by RNA polymerase II inhibitor (5,6-dichloro-1-β-d-ribobenzimidazole), confirming that PRL actions were nongenomic. Exposure to protein kinase C (PKC) or RhoA-associated coiled-coil forming kinase (ROCK) inhibitors (GF-109203X and Y-27632, respectively) abolished the stimulatory effect of PRL on transcellular calcium transport, whereas ROCK inhibitor, but not PKC inhibitor, diminished the PRL effect on paracellular calcium transport. Knockdown of the long isoform of PRL receptor (PRLR-L) also prevented the enhancement of calcium transport by PRL. In addition, PRL markedly increased paracellular sodium permeability and the permeability ratio of sodium to chloride, which are indicators of the paracellular charge-selective property and are known to be associated with the enhanced paracellular calcium transport. The permeability of other cations in the alkali metal series was also increased by PRL, and such increases were abolished by ROCK inhibitor. It could be concluded that PRL stimulated transepithelial calcium transport through PRLR-L and increased paracellular permeability to cations in the Caco-2 monolayer. These nongenomic actions of PRL were mediated by the PKC and ROCK signaling pathways.
Inherited complex I deficiency is associated with faster protein diffusion in the matrix of moving mitochondria
Authors: Koopman Werner J. H. , Distelmaier Felix , Hink Mark A. , Verkaart Sjoerd , Wijers Mietske , Fransen Jack , Smeitink Jan A. M. , Willems Peter H. G. M.
Published: March 2008

Mitochondria continuously change shape, position, and matrix configuration for optimal metabolite exchange. It is well established that changes in mitochondrial metabolism influence mitochondrial shape and matrix configuration. We demonstrated previously that inhibition of mitochondrial complex I (CI or NADH:ubiquinone oxidoreductase) by rotenone accelerated matrix protein diffusion and decreased the fraction and velocity of moving mitochondria. In the present study, we investigated the relationship between inherited CI deficiency, mitochondrial shape, mobility, and matrix protein diffusion. To this end, we analyzed fibroblasts of two children that represented opposite extremes in a cohort of 16 patients, with respect to their residual CI activity and mitochondrial shape. Fluorescence correlation spectroscopy (FCS) revealed no relationship between residual CI activity, mitochondrial shape, the fraction of moving mitochondria, their velocity, and the rate of matrix-targeted enhanced yellow fluorescent protein (mitoEYFP) diffusion. However, mitochondrial velocity and matrix protein diffusion in moving mitochondria were two to three times higher in patient cells than in control cells. Nocodazole inhibited mitochondrial movement without altering matrix EYFP diffusion, suggesting that both activities are mutually independent. Unexpectedly, electron microscopy analysis revealed no differences in mitochondrial ultrastructure between control and patient cells. It is discussed that the matrix of a moving mitochondrion in the CI-deficient state becomes less dense, allowing faster metabolite diffusion, and that fibroblasts of CI-deficient patients become more glycolytic, allowing a higher mitochondrial velocity.
Phosphorylation of β-catenin by PKA promotes ATP-induced proliferation of vascular smooth muscle cells
Authors: Taurin Sebastien , Sandbo Nathan , Yau Douglas M. , Sethakorn Nan , Dulin Nickolai O.
Published: March 2008

Extracellular ATP stimulates proliferation of vascular smooth muscle cells (VSMC) through activation of G protein-coupled P2Y purinergic receptors. We have previously shown that ATP stimulates a transient activation of protein kinase A (PKA), which, together with the established mitogenic signaling of purinergic receptors, promotes proliferation of VSMC (Hogarth DK, Sandbo N, Taurin S, Kolenko V, Miano JM, Dulin NO. Am J Physiol Cell Physiol 287: C449–C456, 2004). We also have shown that PKA can phosphorylate β-catenin at two novel sites (Ser552 and Ser675) in vitro and in overexpression cell models (Taurin S, Sandbo N, Qin Y, Browning D, Dulin NO. J Biol Chem 281: 9971–9976, 2006). β-Catenin promotes cell proliferation by activation of a family of T-cell factor (TCF) transcription factors, which drive the transcription of genes implicated in cell cycle progression including cyclin D1. In the present study, using the phosphospecific antibodies against phospho-Ser552 or phospho-Ser675 sites of β-catenin, we show that ATP can stimulate PKA-dependent phosphorylation of endogenous β-catenin at both of these sites without affecting its expression levels in VSMC. This translates to a PKA-dependent stimulation of TCF transcriptional activity through an increased association of phosphorylated (by PKA) β-catenin with TCF-4. Using the PKA inhibitor PKI or dominant negative TCF-4 mutant, we show that ATP-induced cyclin D1 promoter activation, cyclin D1 protein expression, and proliferation of VSMC are all dependent on PKA and TCF activities. In conclusion, we show a novel mode of regulation of endogenous β-catenin through its phosphorylation by PKA, and we demonstrate the importance of this mechanism for ATP-induced proliferation of VSMC.
Image acquisition for colocalization using optical microscopy
Authors: Scriven David R. L. , Lynch Ronald M. , Moore Edwin D. W.
Published: March 2008

Colocalization, in which images of two or more fluorescent markers are overlaid, and coincidence between the probes is measured or displayed, is a common analytical tool in cell biology. Interpreting the images and the meaning of this identified coincidence is difficult in the absence of basic information about the acquisition parameters. In this commentary, we highlight important factors in the acquisition of images used to demonstrate colocalization, and we discuss the minimum information that authors should include in a manuscript so that a reader can interpret both the fluorescent images and any observed colocalization.
Effects of thyroidectomy, T4, and DITPA replacement on brain blood vessel density in adult rats
Authors: Schlenker Evelyn Heymann , Hora Megan , Liu Yingheng , Redetzke Rebecca A. , Morkin Eugene , Gerdes A. Martin
Published: March 2008

In hypothyroid patients, altered microvascular structure and function may affect mood and cognitive function. We hypothesized that adult male hypothyroid rats will have significantly lower forebrain blood vessel densities (BVD) than euthyroid rats and that treatment with 3,5-diiothyroprionic acid (DITPA) (a thyroid hormone analog) or thyroxine (T4) will normalize BVDs. The euthyroid group received no thyroidectomy or treatment. The other three groups received thyroidectomies and pellets. The hypothyroid group received a placebo pellet, the DITPA group received an 80-mg DITPA-containing pellet, and the T4group received a 5.2-mg T4slow-release pellet for 6 wk. Body weights, cardiac function, and body temperatures were measured. A monoclonal antiplatelet endothelial cell adhesion antibody was used to visualize blood vessels. The euthyroid group averaged body weights of 548 ± 54 g, while the hypothyroid group averaged a body weight of 332 ± 19 g ( P value < 0.001). Relative to the euthyroid group, the DITPA-treated group was significantly lighter ( P value < 0.05), while the T4-treated group was comparable in body weight to the euthyroid group. The same trends were seen with body temperature and cardiac function with the largest difference between the euthyroid and hypothyroid groups. BVD in the euthyroid group was 147 ± 12 blood vessels/mm2and in hypothyroid group 69 ± 5 blood vessels/mm2( P = 0.013) but similar among the euthyroid, DITPA, and T4groups. These results show that hypothyroidism decreased BVD in adult rat forebrain regions. Moreover, DITPA and T4were efficacious in preventing effects of hypothyroidism on cardiac function and BVD.
Inflammatory gene changes associated with the repeated-bout effect
Authors: Hubal Monica J. , Chen Trevor C. , Thompson Paul D. , Clarkson Priscilla M.
Published: March 2008

This study proposed that attenuated expression of inflammatory factors is an underlying mechanism driving the repeated-bout effect (rapid adaptation to eccentric exercise). We investigated changes in mRNA levels and protein localization of inflammatory genes after two bouts of muscle-lengthening exercise. Seven male subjects performed two bouts of lower body exercise (separated by 4 wk) in which one leg performed 300 eccentric-concentric actions, and the contralateral leg performed 300 concentric actions only. Vastus lateralis biopsies were collected at 6 h, and strength was assessed at baseline and at 0, 3, and 5 days after exercise. mRNA levels were measured via semiquantitative RT-PCR for the following genes: CYR61, HSP40, HSP70, IL1R1, TCF8, ZFP36, CEBPD, and MCP1. Muscle functional adaptation was demonstrated via attenuated strength loss (16% less, P = 0.04) at 5 days after bout 2 compared with bout 1 in the eccentrically exercised leg. mRNA expression of three of the eight genes tested was significantly elevated in the eccentrically exercised leg from bout 1 to bout 2 (+3.9-fold for ZFP36, +2.3-fold for CEBPD, and +2.6-fold for MCP1), while all eight mRNA levels were unaffected by bout in the concentrically exercised leg. Immunohistochemistry further localized the protein of one of the elevated factors [monocyte chemoattractant protein-1 (MCP1)] within the tissue. MCP1 colocalized with resident macrophage and satellite cell populations, suggesting that alterations in cytokine signaling between these cell populations may play a role in muscle adaptation to exercise. Contrary to our hypothesis, several inflammatory genes were transcriptionally upregulated (rather than attenuated) after a repeated exercise bout, potentially indicating a role for these genes in the adaptation process.