bluuebunny/crossref_metadata_2025 huggingface dataset:
Singularity avoidance, lattices, and quantum gravity
Authors: Husain V
Published: June 2008

An ingredient in recent discussions of curvature singularity avoidance in quantum gravity is the “inverse scale factor” operator in quantum cosmology, and its generalizations to field theoretic models such as scalar-field collapse in spherical symmetry. I describe a general lattice origin of this idea, and show how it applies to the Coulomb singularity in quantum mechanics. The example demonstrates that a discretized Schrodinger equation is computationally equivalent to the so-called polymer quantization derived loop quantum gravity. This applies also to lattice discretized forms of the Wheeler–deWitt equation.PACS Nos.: 04.60.–m, 04.60.Ds, 04.70.Dy
Catalyzed Big-Bang nucleosynthesis
Authors: Pospelov M
Published: June 2008

We point out that the existence of metastable, τ >103 s, negatively charged electroweak-scale particles (X–) alters the predictions for lithium and other primordial elemental abundances for A > 4 via the formation of bound states with nuclei during Big-Bang nucleosynthesis (BBN). In particular, we show that the bound states of X– with helium, formed at temperatures of about T = 108 K, lead to the catalytic enhancement of 6Li production, which is eight orders of magnitude more efficient than the standard channel. In particle physics models, where subsequent decay of X– does not lead to large nonthermal BBN effects, this directly translates to the level of sensitivity to the number density of long-lived X– particles (τ > 105 s) relative to entropy of nX – / s [Formula: see text] 3 × 10–17, which is one of the most stringent probes of electroweak scale remnants known to date. It is also argued that unstable charged particles with lifetime of order ~2000 s may naturally lead to the depletion of 7Li by a factor of two, making it consistent with observationally determined abundances. PACS No.: 98.80.Ft
Entangling identical bosons in optical tweezers via exchange interaction
Authors: Babcock N S , Stock R , Raizen M G , Sanders B C
Published: June 2008

We first devise a scheme to perform a universal entangling gate via controlled collisions between pairs of atomic qubits trapped with optical tweezers. Second, we present a modification to this scheme to allow for the preparation of atomic Bell pairs via selective excitation, suitable for quantum-information-processing applications that do not require universality. Both these schemes are enabled by the inherent symmetries of identical composite particles, as originally proposed by Hayes et al. Our scheme provides a technique for producing weighted graph states, entangled resources for quantum communication, and a promising approach to performing a “loophole free” Bell test in a single laboratory.PACS Nos.: 03.65.Ud, 03.67.Mn, 32.80.Pj, 42.50.Vk
CALCULATION OF ELECTRONIC STRUCTURE OF A SPHERICAL QUANTUM DOT USING A COMBINATION OF QUANTUM GENETIC ALGORITHM AND HARTREE–FOCK–ROOTHAAN METHOD
Authors: ÇAKIR BEKİR , ÖZMEN AYHAN , ATAV ÜLFET , YÜKSEL HÜSEYİN , YAKAR YUSUF
Published: June 2008

The electronic structure of Quantum Dot (QD), GaAs/Al x Ga 1-x As , has been investigated by using a combination of Quantum Genetic Algorithm (QGA) and Hartree–Fock–Roothaan (HFR) method. One-electron system with an on-center impurity is considered by assuming a spherically symmetric confining potential of finite depth. The ground and excited state energies of one-electron QD were calculated depending on the dot radius and stoichiometric ratio. Expectation values of energy were determined by using the HFR method along with Slater-Type Orbitals (STOs) and QGA was used for the wavefunctions optimization. In addition, the effect of the size of the basis set on the energy of QD was investigated. We also calculated the binding energy for a dot with finite confining potential. We found that the impurity binding energy increases for the finite potential well when the dot radius decreases. For the finite potential well, the binding energy reaches a peak value and then diminishes to a limiting value corresponding to the radius for which there are no bound states in the well. Whereas in previous study, in Ref. 40, for the infinite potential well, we found that the impurity binding energy increases as the dot radius decreases.
THE GALAM MODEL OF MINORITY OPINION SPREADING AND THE MARRIAGE GAP
Authors: KUŁAKOWSKI KRZYSZTOF , NAWOJCZYK MARIA
Published: June 2008

In 2002, Serge Galam designed a model of a minority opinion spreading. The effect is expected to lead a conservative minority to prevail if the issue is discussed long enough. Here we analyze the marriage gap, i.e., the difference in voting for Bush and Kerry in 2004 and for Bush and Gore in 2000 between married and unmarried people. It seems possible to interpret the data in terms of the Galam model.
ANALYTICAL APPROACH TO BIT-STRING MODELS OF LANGUAGE EVOLUTION
Authors: ZANETTE DAMIÁN H.
Published: June 2008

A formulation of bit-string models of language evolution, based on differential equations for the population speaking each language, is introduced and preliminarily studied. Connections with replicator dynamics and diffusion processes are pointed out. The stability of the dominance state, where most of the population speaks a single language, is analyzed within a mean-field-like approximation, while the homogeneous state, where the population is evenly distributed among languages, can be studied. This analysis discloses the existence of a bistability region, where dominance coexists with homogeneity as possible asymptotic states. Numerical resolution of the differential system validates these findings.
TREATMENTS OF THE EXCHANGE ENERGY IN DENSITY-FUNCTIONAL THEORY
Authors: GÁL TAMÁS
Published: June 2008

Following a recent work [Gál, Phys. Rev. A64, 062503 (2001)], a simple derivation of the density-functional correction of the Hartree–Fock equations, the Hartree–Fock–Kohn–Sham equations, is presented, completing an integrated view of quantum mechanical theories, in which the Kohn–Sham equations, the Hartree–Fock–Kohn–Sham equations and the ground-state Schrödinger equation formally stem from a common ground: density-functional theory, through its Euler equation for the ground-state density. Along similar lines, the Kohn–Sham formulation of the Hartree–Fock approach is also considered. Further, it is pointed out that the exchange energy of density-functional theory built from the Kohn–Sham orbitals can be given by degree-two homogeneous N-particle density functionals (N = 1, 2, …), forming a sequence of degree-two homogeneous exchange-energy density functionals, the first element of which is minus the classical Coulomb-repulsion energy functional.
TEMPERATURE DEPENDENCE OF ELECTRICAL CHARACTERISTICS OF Cr/p–Si(100) SCHOTTKY BARRIER DIODES
Authors: ERTURK K. , HACIISMAILOGLU M. C. , BEKTORE Y. , AHMETOGLU M.
Published: June 2008

The electrical characteristics of Cr / p – Si (100) Schottky barrier diodes have been measured in the temperature range of 100–300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41×10-3 Acm-2 K -2 is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm-2 K -2 for p-type Si . It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p – Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.
THE EFFECT OF THE INCREASE OF LINEAR DIMENSIONS ON EXPONENTS OBTAINED BY FINITE-SIZE SCALING RELATIONS FOR THE FOUR-DIMENSIONAL ISING MODEL ON THE CREUTZ CELLULAR AUTOMATON
Authors: MÜLAZIMOGLU G. , DURAN A. , MERDAN Z. , GUNEN A.
Published: June 2008

The four-dimensional Ising model is simulated on the Creutz cellular automaton using finite-size lattices with linear dimension 4 ≤ L ≤ 22. The exponents in the finite-size scaling relations for the order parameter, the magnetic susceptibility at the finite-lattice critical temperature and the specific heat at the infinite-lattice critical temperature are computed to be β = 0.5072(58), γ = 1.0287(56) and α = -0.096(17), respectively, which are consistent with the renormalization group prediction of β = 0.5, γ = 1 and α = 0. The critical temperatures for the infinite lattice are found to be [Formula: see text] and [Formula: see text], which are also consistent with the precise results.
STRESS DISTRIBUTION AND DAMAGE MODE OF CERAMIC–DENTIN BILAYER SYSTEMS
Authors: KURTOGLU CEM , DEMIROZ S. SUNA , MEHMETOV EMIRULLAH , UYSAL HAKAN
Published: June 2008

The aim of this study was to evaluate the damage modes of ceramic systems bonded to dentin under Hertzian indentation. Single-cycle Hertzian contact test over 150–850 N load range was applied randomly to 210 ceramic–dentin bilayer disc specimens of zirconia or IPS Empress II -1 mm, -1.5 mm and of feldspathic porcelain -1 mm, -1.5 mm, -2 mm. Optical microscopy was employed for the identification of quasiplastic mode and radial cracks. Finite element analysis was used to analyze the stress distribution. Our results showed that the degree of damage in both modes evolved progressively and the origin changed with contact load. Stress location and value were consistent with the mechanical test results. It was concluded that microstructure and thickness of the material have a significant effect on the damage modes of ceramic layer systems.
INTERMEDIATE VALENCE METALS
Authors: LAWRENCE JON
Published: June 2008

The ground state of rare earth intermediate valence (IV) metals is that of a heavy mass Fermi liquid. The transport, optical conductivity, dHvA signals, and Q-resolved neutron spectra reflect the existence of a Fermi surface with strongly renormalized masses and a hybridization gap. On the other hand, properties such as the susceptibility, specific heat, valence and spin dynamics that are dominated by the spin fluctuations, which are highly localized, can be understood qualitatively (and sometimes quantitatively) as those of a collection of non-interacting Anderson/Kondo impurities. Anomalies exist in some compounds both in the low temperature behavior and in the rate of crossover from Fermi liquid to local moment behavior which may reflect non-universal behavior of the Anderson lattice.
GENERATION OF STRONGLY CHAOTIC BEATS
Authors: ŚLIWA I. , SZLACHETKA P. , GRYGIEL K.
Published: June 2008

This letter proposes a procedure for generating strongly chaotic beats that have been hardly obtainable hitherto. The beats are produced in a nonlinear optical system governing second-harmonic generation of light. The proposition is based on the concept of an optical coupler, but can be easily adopted to other nonlinear systems and Chua's circuits.
A SYSTEM AND CIRCUIT FOR GENERATING "MULTI-BUTTERFLIES"
Authors: ELWAKIL A. S. , ÖZOGUZ S.
Published: June 2008

A system for generating a multi-butterfly chaotic attractor using the multi-level-logic pulse-excitation technique is proposed. Two-butterfly, three-butterfly and four-butterfly attractors are demonstrated. Results from an experimental setup are also shown.
FEIGENBAUM ATTRACTOR AND THE GENERATION STRUCTURE OF PARTICLE PHYSICS
Authors: GOLDFAIN ERVIN
Published: June 2008

The standard model (SM) for high-energy physics describes fundamental interactions between subatomic particles down to a distance scale on the order of 10-18 m. Despite its widespread acceptance, SM operates with a large number of arbitrary parameters whose physical origin is presently unknown. Our work suggests that the generation structure of at least some SM parameters stems from the chaotic regime of renormalization group flow. Invoking the universal route to chaos in systems of nonlinear differential equations, we argue that the hierarchical pattern of parameters amounts to a series of scaling ratios depending on the Feigenbaum constant. Leading order predictions are shown to agree reasonably well with experimental data.
SPECIFICATION AND COMPUTING STATES IN FUZZY ALGORITHMS
Authors: LOPEZ VICTORIA , MONTERO JAVIER , GARMENDIA LUIS , RESCONI GERMANO
Published: June 2008

Since many complex decision making problems can be solved solely by means of an appropriate algorithm, checking the quality of such algorithm is a key issue, even more relevant in the presence of fuzzy uncertainty. In this paper we postulate that the design and formal specification of algorithms can be translated into a fuzzy framework introducing fuzzy first order logic and assert transformations. Following the classical crisp scheme we first formalize the concepts of a fuzzy algorithm specification and a fuzzy computing state, and then a new fuzzy computational logic is presented, so we can derive a computational reasoning for correctness of algorithms. A proposal for the evaluation and setting of suitable degrees of truth to computing states is also introduced.
USING GENETIC ALGORITHMS TO SOLVE FUZZY FLOW SHOP SCHEDULING PROBLEMS BASED ON POSSIBILITY AND NECESSITY MEASURES
Authors: LAI PENG-JEN , WU HSIEN-CHUNG
Published: June 2008

The scheduling problems with fuzzy processing times and fuzzy due dates are investigated in this paper. The concepts of earliness and tardiness are interpreted by using the concepts of possibility and necessity measures that were developed in fuzzy sets theory. Many types of objective function will be taken into account through the different combinations of possibility and necessity measures. The purpose of this paper is to obtain the optimal schedules based on these objective functions. The genetic algorithm will be invoked to tackle these objective functions. Four numerical examples are also provided and solved by using the commercial software MATLAB.
Software design and the monkey's brain
Authors: Glass Robert L.
Published: June 2008

Attempting to capture the nature of software design.
Information accountability
Authors: Weitzner Daniel J. , Abelson Harold , Berners-Lee Tim , Feigenbaum Joan , Hendler James , Sussman Gerald Jay
Published: June 2008

With access control and encryption no longer capable of protecting privacy, laws and systems are needed that hold people accountable for the misuse of personal information, whether public or secret.
Ubiquitous access
Authors: Abraham Chon , Watson Richard T. , Boudreau Marie-Claude
Published: June 2008

UA initiatives help allay potentially fatal errors, improve patient safety, and boost overall quality of care.
Foundational certified code in the Twelf metalogical framework
Authors: Crary Karl , Sarkar Susmit
Published: June 2008

Foundational certified code systems seek to prove untrusted programs to be safe relative to safety policies given in terms of actual machine architectures, thereby improving the systems' flexibility and extensibility. Using the Twelf metalogical framework, we have constructed a safety policy for the IA-32 architecture with a trusted runtime library. The safety policy is based on a formalized operational semantics. We have also developed a complete, foundational proof that a fully expressive typed assembly language satisfies that safety policy.
Inferring non-suspension conditions for logic programs with dynamic scheduling
Authors: Genaim Samir , King Andy
Published: June 2008

A logic program consists of a logic component and a control component. The former is a specification in predicate logic whereas the latter defines the order of subgoal selection. The order of subgoal selection is often controlled with delay declarations that specify that a subgoal is to suspend until some condition on its arguments is satisfied. Reasoning about delay declarations is notoriously difficult for the programmer and it is not unusual for a program and a goal to reduce to a state that contains a subgoal that suspends indefinitely. Suspending subgoals are usually unintended and often indicate an error in the logic or the control. A number of abstract interpretation schemes have therefore been proposed for checking that a given program and goal cannot reduce to such a state. This article considers a reversal of this problem, advocating an analysis that for a given program infers a class of goals that do not lead to suspension. This article shows that this more general approach can have computational, implementational and user-interface advantages. In terms of user-interface, this approach leads to a lightweight point-and-click mode of operation in which, after directing the analyser at a file, the user merely has to inspect the results inferred by the analysis. In terms of implementation, the analysis can be straightforwardly realized as two simple fixpoint computations. In terms of computation, by modeling
n
! different schedulings of
n
subgoals with a single Boolean function, it is possible to reason about the suspension behavior of large programs. In particular, the analysis is fast enough to be applied repeatedly within the program development cycle. The article also demonstrates that the method is precise enough to locate bugs in existing programs.
Abstract state machines capture parallel algorithms
Authors: Blass Andreas , Gurevich Yuri
Published: June 2008

We consider parallel algorithms working in sequential global time, for example, circuits or parallel random access machines (PRAMs). Parallel abstract state machines (parallel ASMs) are such parallel algorithms, and the parallel ASM thesis asserts that every parallel algorithm is behaviorally equivalent to a parallel ASM. In an earlier article, we axiomatized parallel algorithms, proved the ASM thesis, and proved that every parallel ASM satisfies the axioms. It turned out that we were too timid in formulating the axioms; they did not allow a parallel algorithm to create components on the fly. This restriction did not hinder us from proving that the usual parallel models, like circuits or PRAMs or even alternating Turing machines, satisfy the postulates. But it resulted in an error in our attempt to prove that parallel ASMs always satisfy the postulates. To correct the error, we liberalize our axioms and allow on-the-fly creation of new parallel components. We believe that the improved axioms accurately express what parallel algorithms ought to be. We prove the parallel thesis for the new, corrected notion of parallel algorithms, and we check that parallel ASMs satisfy the new axioms.
Proof search in Hájek's basic logic
Authors: Bova Simone , Montagna Franco
Published: June 2008

We introduce a proof system for Hájek's logic
BL
based on a relational hypersequents framework. We prove that the rules of our logical calculus, called
RHBL
, are sound and invertible with respect to any valuation of
BL
into a suitable algebra, called (ω)[0,1]. Refining the notion of reduction tree that arises naturally from
RHBL
, we obtain a decision algorithm for
BL
provability whose running time upper bound is 2

O
(
n
)

, where
n
is the number of connectives of the input formula. Moreover, if a formula is unprovable, we exploit the constructiveness of a polynomial time algorithm for leaves validity for providing a procedure to build countermodels in (ω)[0, 1]. Finally, since the size of the reduction tree branches is
O
(
n
3
), we can describe a polynomial time verification algorithm for
BL
unprovability.
Evolution of Dim-Light and Color Vision Pigments
Authors: Yokoyama Shozo
Published: June 2008

A striking level of diversity of visual systems in different species reflects their adaptive responses to various light environments. To study the adaptive evolution of visual systems, we need to understand how visual pigments, the light-sensitive molecules, have tuned their wavelengths of light absorption. The molecular basis of spectral tuning in visual pigments, a central unsolved problem in phototransduction, can be understood only by studying how different species have adapted to various light environments. Certain amino acid replacements at 30 residues explain some dim-light and color vision in vertebrates. To better understand the molecular and functional adaptations of visual pigments, we must identify all critical amino acid replacements that are involved in the spectral tuning and elucidate the effects of their interactions on the spectral shifts.
Disorders of Lysosome-Related Organelle Biogenesis: Clinical and Molecular Genetics
Authors: Huizing Marjan , Helip-Wooley Amanda , Westbroek Wendy , Gunay-Aygun Meral , Gahl William A.
Published: June 2008

Lysosome-related organelles (LROs) are a heterogeneous group of vesicles that share various features with lysosomes, but are distinct in function, morphology, and composition. The biogenesis of LROs employs a common machinery, and genetic defects in this machinery can affect all LROs or only an individual LRO, resulting in a variety of clinical features. In this review, we discuss the main components of LRO biogenesis. We also summarize the function, composition, and resident cell types of the major LROs. Finally, we describe the clinical characteristics of the major human LRO disorders.
From Linkage Maps to Quantitative Trait Loci: The History and Science of the Utah Genetic Reference Project
Authors: Prescott Stephen M. , Lalouel Jean Marc , Leppert Mark
Published: June 2008

One of the early decisions in what became the Human Genome Project was to recruit families that would serve as a reference set, thereby focusing efforts to create human genetic maps on the same sets of DNA samples. The families recruited from Utah provided the most widely used samples in the Centre d′Etudes du Polymorphisme Humain (CEPH) set, were instrumental in generating human linkage maps, and often serve as the benchmark for establishing allele frequency when a new variant is identified. In addition, the immortalized cell lines created from the peripheral blood cells of these subjects are a broadly used resource and have yielded insights in many areas, from the genetics of gene expression to the regulation of telomeres. More recently, these families were recontacted and underwent extensive, protocol-based evaluation to create a phenotypic database, which will aid in the study of the genetic basis of quantitative traits. As with the earlier efforts, this project involved collaborations among many investigators and has yielded insights into multiple traits.
Rules of Engagement: Interspecies Interactions that Regulate Microbial Communities
Authors: Little Ainslie E.F. , Robinson Courtney J. , Peterson S. Brook , Raffa Kenneth F. , Handelsman Jo
Published: June 2008

Microbial communities comprise an interwoven matrix of biological diversity modified by physical and chemical variation over space and time. Although these communities are the major drivers of biosphere processes, relatively little is known about their structure and function, and predictive modeling is limited by a dearth of comprehensive ecological principles that describe microbial community processes. Here we discuss working definitions of central ecological terms that have been used in various fashions in microbial ecology, provide a framework by focusing on different types of interactions within communities, review the status of the interface between evolutionary and ecological study, and highlight important similarities and differences between macro- and microbial ecology. We describe current approaches to study microbial ecology and progress toward predictive modeling.
Population Structure of Toxoplasma gondii: Clonal Expansion Driven by Infrequent Recombination and Selective Sweeps
Authors: Sibley L. David , Ajioka James W.
Published: June 2008

Toxoplasma gondii is among the most successful parasites. It is capable of infecting all warm-blooded animals and causing opportunistic disease in humans. T. gondii has a striking clonal population structure consisting of three predominant lineages in North America and Europe. Clonality is associated with the recent emergence of a monomorphic version of Chr1a, which drove a selective genetic sweep within the past 10,000 years. Strains from South America diverged from those in North America some 1–2 mya; recently, however, the monomorphic Chr1a has extended into regions of South America, where it is also associated with clonality. The recent spread of a few dominant lineages has dramatically shaped the population structure of T. gondii and has resulted in most lineages sharing a highly pathogenic nature. Understanding the factors that have shaped the population structure of T. gondii has implications for the emergence and transmission of human pathogens.
Functional and structural characterization of the zebrafish Na+-sulfate cotransporter 1 (NaS1) cDNA and gene (slc13a1)
Authors: Markovich Daniel , Romano Alessandro , Storelli Carlo , Verri Tiziano
Published: June 2008

Sulfate plays an essential role during growth, development and cellular metabolism. In this study, we characterized the function and structure of the zebrafish ( Danio rerio) Na+-sulfate cotransporter 1 (NaS1) cDNA and gene ( slc13a1). Zebrafish NaS1 encodes a protein of 583 amino acids with 13 putative transmembrane domains. Expression of zebrafish NaS1 protein in Xenopus oocytes led to Na+-sulfate cotransport, which was significantly inhibited by thiosulfate, selenate, molybdate, and tungstate. Zebrafish NaS1 transport kinetics were: Vmax = 1,731.670 ± 92.853 pmol sulfate/oocyte·hour and Km = 1.414 ± 0.275 mM for sulfate and Vmax = 307.016 ± 32.992 pmol sulfate/oocyte·hour, Km = 24.582 ± 4.547 mM and n (Hill coefficient) = 1.624 ± 0.354 for sodium. Zebrafish NaS1 mRNA is developmentally expressed in embryos from day 1 postfertilization and in the intestine, kidney, brain, and eye of adult zebrafish. The zebrafish NaS1 gene slc13a1 contains 15 exons spanning 8,716 bp. Characterization of the zebrafish NaS1 contributes to a greater understanding of sulfate transporters in a well-defined genetic model and will allow the elucidation of evolutionary and functional relationships among vertebrate sulfate transporters.
Preliminary Results of the Combination of Bevacizumab and Weekly Paclitaxel in Advanced Melanoma
Authors: González-Cao M. , Viteri S. , Díaz-Lagares A. , González A. , Redondo P. , Nieto Y. , Espinós J. , Chopitea A. , Ponz M. , Martín-Algarra S.
Published: June 2008

Background: Pretreated advanced melanoma is a poor prognosis scenario with few, if any, active therapeutic options. The antibody against vascular endothelial growth factor, bevacizumab, has demonstrated increased activity in combination with chemotherapy in many tumors. We intended to evaluate the activity of the combination of weekly paclitaxel and bevacizumab in previously treated metastatic melanoma. Patients and Methods: Patients with previously treated metastatic melanoma received paclitaxel 70 mg/m2 weekly and bevacizumab 10 mg/kg biweekly for 5 consecutive weeks every 6 weeks. Results: Twelve patients were treated. Two patients (16.6%) achieved a partial response and 7 patients (58.3%) stable disease. Responses were seen in soft tissue, lung and brain metastases. Median disease-free and overall survival times were 3.7 and 7.8 months, respectively. Treatment was well tolerated. Main toxicities were grade 3 asymptomatic lymphopenia in 6 patients, grade 3 leucopenia in 2 patients, and grade 3 thrombocytopenia in 1 patient. Conclusions: Our preliminary results suggest that the combination of bevacizumab and weekly paclitaxel is active and safe in patients with metastatic melanoma, warranting further investigation.
Cardiomyocyte Overexpression of Neuronal Nitric Oxide Synthase Delays Transition Toward Heart Failure in Response to Pressure Overload by Preserving Calcium Cycling
Authors: Loyer Xavier , Gómez Ana Maria , Milliez Paul , Fernandez-Velasco Maria , Vangheluwe Peter , Vinet Laurent , Charue Dominique , Vaudin Emilie , Zhang Wei , Sainte-Marie Yannis , Robidel Estelle , Marty Isabelle , Mayer Bernd , Jaisser Frédéric , Mercadier Jean-Jacques , Richard Sylvain , Shah Ajay M. , Bénitah Jean-Pierre , Samuel Jane-Lise , Heymes Christophe
Published: June 2008

Background—

Defects in cardiomyocyte Ca
2+
cycling are a signature feature of heart failure (HF) that occurs in response to sustained hemodynamic overload, and they largely account for contractile dysfunction. Neuronal nitric oxide synthase (NOS1) influences myocyte excitation-contraction coupling through modulation of Ca
2+
cycling, but the potential relevance of this in HF is unknown.

Methods and Results—

We generated a transgenic mouse with conditional, cardiomyocyte-specific NOS1 overexpression (double-transgenic [DT]) and studied cardiac remodeling, myocardial Ca
2+
handling, and contractility in DT and control mice subjected to transverse aortic constriction (TAC). After TAC, control mice developed eccentric hypertrophy with evolution toward HF as revealed by a significantly reduced fractional shortening. In contrast, DT mice developed a greater increase in wall thickness (
P
<0.0001 versus control+TAC) and less left ventricular dilatation than control+TAC mice (
P
<0.0001 for both end-systolic and end-diastolic dimensions). Thus, DT mice displayed concentric hypertrophy with fully preserved fractional shortening (43.7±0.6% versus 30.3±2.6% in control+TAC mice,
P
<0.05). Isolated cardiomyocytes from DT+TAC mice had greater shortening, intracellular Ca
2+
transients, and sarcoplasmic reticulum Ca
2+
load (
P
<0.05 versus control+TAC for all parameters). These effects could be explained, at least in part, through modulation of phospholamban phosphorylation status.

Conclusions—

Cardiomyocyte NOS1 may be a useful target against cardiac deterioration during chronic pressure-overload–induced HF through modulation of calcium cycling.
Cyclophilin A Mediates Vascular Remodeling by Promoting Inflammation and Vascular Smooth Muscle Cell Proliferation
Authors: Satoh Kimio , Matoba Tetsuya , Suzuki Jun , O'Dell Michael R. , Nigro Patrizia , Cui Zhaoqiang , Mohan Amy , Pan Shi , Li Lingli , Jin Zheng-Gen , Yan Chen , Abe Jun-ichi , Berk Bradford C.
Published: June 2008

Background—

Oxidative stress, generated by excessive reactive oxygen species, promotes cardiovascular disease. Cyclophilin A (CyPA) is a 20-kDa chaperone protein secreted from vascular smooth muscle cells (VSMCs) in response to reactive oxygen species that stimulates VSMC proliferation and inflammatory cell migration in vitro; however, the role CyPA plays in vascular function in vivo remains unknown.

Methods and Results—

We tested the hypothesis that CyPA contributes to vascular remodeling by analyzing the response to complete carotid ligation in CyPA knockout mice, wild-type mice, and mice that overexpress CyPA in VSMC (VSMC-Tg). After carotid ligation, CyPA expression in vessels of wild-type mice increased dramatically and was significantly greater in VSMC-Tg mice. Reactive oxygen species–induced secretion of CyPA from mouse VSMCs correlated significantly with intracellular CyPA expression. Intimal and medial hyperplasia correlated significantly with CyPA expression after 2 weeks of carotid ligation, with marked decreases in CyPA knockout mice and increases in VSMC-Tg mice. Inflammatory cell migration into the intima was significantly reduced in CyPA knockout mice and increased in VSMC-Tg mice. Additionally, VSMC proliferation assessed by Ki67
+
cells was significantly less in CyPA knockout mice and was increased in VSMC-Tg mice. The importance of CyPA for intimal and medial thickening was shown by strong correlations between CyPA expression and the number of both inflammatory cells and proliferating VSMCs in vivo and in vitro.

Conclusions—

In response to low flow, CyPA plays a crucial role in VSMC migration and proliferation, as well as inflammatory cell accumulation, thereby regulating flow-mediated vascular remodeling and intima formation.
Obesity, Behavioral Lifestyle Factors, and Risk of Acute Coronary Events
Authors: Jensen Majken K. , Chiuve Stephanie E. , Rimm Eric B. , Dethlefsen Claus , Tjønneland Anne , Joensen Albert M. , Overvad Kim
Published: June 2008

Background—

Whether physical activity reduces the impact of obesity on the risk of acute coronary events is much debated. However, little is known about the role of other potentially modifiable lifestyle factors in combination with obesity.

Methods and Results—

We followed up 54 783 women and men from the prospective Danish Diet, Cancer and Health study who were 50 to 64 years at baseline (1993 to 1997) and free of coronary artery disease and cancer. During a median of 7.7 years, 1127 incident cases of acute coronary syndrome (ACS) occurred. After multivariable adjustments, each unit of body mass index was associated with a 5% and 7% higher risk of ACS among women and men, respectively (both
P
<0.0001 for trend). Overweight (body mass index, 25 to 29.9 kg/m
2
) and obesity (body mass index ≥30 kg/m
2
) were associated with a higher risk of ACS among the physically active and inactive, in nonsmokers and smokers, and among those who adhered more or less to a heart-healthy dietary pattern. Obese individuals who were active 1 to 3.5 h/wk had a lower risk than sedentary, obese individuals. In addition, obese nonsmokers had a lower risk than obese smokers. Adherence to a healthy diet was associated with a lower risk of ACS; however, the relative risk was not different among obese individuals with the most healthy diet versus obese individuals with a less healthy diet.

Conclusions—

Obesity confers an elevated risk of ACS in both healthy and less healthy subgroups of lifestyle behaviors. Adherence to healthy lifestyle behaviors was associated with a lower risk even among obese individuals.
Intracellular Protein Aggregation Is a Proximal Trigger of Cardiomyocyte Autophagy
Authors: Tannous Paul , Zhu Hongxin , Nemchenko Andriy , Berry Jeff M. , Johnstone Janet L. , Shelton John M. , Miller Francis J. , Rothermel Beverly A. , Hill Joseph A.
Published: June 2008

Background—

Recent reports demonstrate that multiple forms of cardiovascular stress, including pressure overload, chronic ischemia, and infarction-reperfusion injury, provoke an increase in autophagic activity in cardiomyocytes. However, nothing is known regarding molecular events that stimulate autophagic activity in stressed myocardium. Because autophagy is a highly conserved process through which damaged proteins and organelles can be degraded, we hypothesized that stress-induced protein aggregation is a proximal trigger of cardiomyocyte autophagy.

Methods and Results—

Here, we report that pressure overload promotes accumulation of ubiquitinated protein aggregates in the left ventricle, development of aggresome-like structures, and a corresponding induction of autophagy. To test for causal links, we induced protein accumulation in cultured cardiomyocytes by inhibiting proteasome activity, finding that aggregation of polyubiquitinated proteins was sufficient to induce cardiomyocyte autophagy. Furthermore, attenuation of autophagic activity dramatically enhanced both aggresome size and abundance, consistent with a role for autophagic activity in protein aggregate clearance.

Conclusions—

We conclude that protein aggregation is a proximal trigger of cardiomyocyte autophagy and that autophagic activity functions to attenuate aggregate/aggresome formation in heart. Findings reported here are the first to demonstrate that protein aggregation occurs in response to hemodynamic stress, situating pressure-overload heart disease in the category of proteinopathies.
Role of Inflammation in the Development of Renal Damage and Dysfunction in Angiotensin II–Induced Hypertension
Authors: Liao Tang-Dong , Yang Xiao-Ping , Liu Yun-He , Shesely Edward G. , Cavasin Maria A. , Kuziel William A. , Pagano Patrick J. , Carretero Oscar A.
Published: June 2008

Angiotensin II (Ang II)–induced hypertension is associated with an inflammatory response that may contribute to the development of target organ damage. We tested the hypothesis that, in Ang II–induced hypertension, CC chemokine receptor 2 (CCR2) activation plays an important role in the development of renal fibrosis, damage, and dysfunction by causing oxidative stress, macrophage infiltration, and cell proliferation. To test this hypothesis, we used CCR2 knockout mice (CCR2
−/−
). The natural ligand of CCR2 is monocyte chemoattractant protein-1, a chemokine important for macrophage recruitment and activation. CCR2
−/−
and age-matched wild-type (CCR2
+/+
) C57BL/6J mice were infused continuously with either Ang II (5.2 ng/10 g per minute) or vehicle via osmotic minipumps for 2 or 4 weeks. Ang II infusion caused similar increases in systolic blood pressure and left ventricular hypertrophy in both strains of mice. However, in CCR2
−/−
mice with Ang II–induced hypertension, oxidative stress, macrophage infiltration, albuminuria, and renal damage were significantly decreased, and glomerular filtration rate was significantly higher than in CCR2
+/+
mice. We concluded that, in Ang II–induced hypertension, CCR2 activation plays an important role in the development of hypertensive nephropathy via increased oxidative stress and inflammation.
Habitat Defense in Southeast Asian Cities
Authors: Aldrich Brian C.
Published: June 2008

Using interviews with public officials and activists as well as research reports available in Southeast Asia, this research compares the level of organization, mobilization and collective action among neolocal urban groups threatened with removal and relocation for large infrastructure projects. The results show that habitat defense is extensive in Bangkok, Jakarta and Manila, but minor or non-existent in Singapore, Hong Kong and Kuala Lumpur. A model of collective action is nested in an ecological model to explain differences in level of habitat defense among the six Southeast Asian cities.
The Political Role of the Indonesian Military: Past, Present and Future
Authors: Said Salim
Published: June 2008

This paper attempts to briefly examine the political role of the Indonesian military from its inception to its dominant position in Indonesian politics today. It also attempts to discuss whether or not it would continue to play the same role in the future. The paper will be divided into three sections: the political role of the military during the revolution, the increased political involvement of the military, conflicting interpretations of the military role and the possibility of future change.
Locating the Ottomans Among Early Modern Empires
Authors: Aksan Virginia H.
Published: June 2008

This paper describes the evolution of Ottoman military and defensive strategies in the Balkans from 1600 to 1800. It argues that three major imperial crises, engendered by sustained warfare, forced a transition from a standing army to state commissioned militias. To do so, it sites the Ottoman imperial context in a discussion of multiethnic eastern European empires, comparing Ottoman options and limitations with those of the Habsburgs and the Romanovs for the same period. The geopolitics of Danubian and Black Sea frontier territories, and the relationship between imperial center and native elites serve as two points of comparison, emphasizing the interplay between sovereignty, religious affiliation, and assimilation. By the end of the eighteenth century, Ottoman contraction and the movement of large numbers of Muslim refugees from surrendered territories, meant the increased nomadization of central Ottoman lands, and the almost total reliance on undisciplined, volunteer militias as a fighting force, whose acculturation to "Ottomanism" was never desired nor attempted by the ruling elite.
Crossing the Borders: Ireland and the Irish Between England and America
Authors: Hadfield Andrew
Published: June 2008

Historians of early modern Ireland have often been rather too monolithic in their readings of representations of Ireland and the Irish. Many commentators now insist that Ireland has to be viewed in terms of British or European developments. Using examples from a selection of writers—Luke Gernon, Sir Henry Sidney, Sir William Herbert, John Derricke, Barnaby Rich, Sir John Davies—this article argues that Ireland was invariably represented through the use of overlapping, often competing, discourses of savagery and domestic political concerns. In themselves, such discourses can be further sub-divided into various empirical and theoretical modes of writing. Moreover, identical representations were often produced or read in different ways so that the significance of context and register has to be taken into account when examining the evidence available.
Useful To Have, But Difficult To Govern. Inns and Taverns in Early Modern Bern and Vaud
Authors: Kümin Beat
Published: June 2008

This essay examines the significance of inns and taverns in the early modern period. Drawing above all on a series of registers from the French and German lands of the Swiss Republic of Bern, the discussion is presented in two parts. A first section investigates structural aspects such as ownership, clientele, and the remarkably multifunctional character of these establishments. The second part illustrates the continuing growth in provision during the Ancien Régime and the limited impact of government regulation. It is argued that inns and taverns became the most prominent social centres in early modern local communities and that popular demand for their services prevailed over sustained campaigns to restrict numbers and discipline patrons.
Invented Identities: Credulity in the Age of Prophecy and Exploration
Authors: Eliav-Feldon Miriam
Published: June 2008

The sixteenth century was a golden age for impostors and pretenders of many kinds. In addition to the pre-modem lack of means for establishing a person's identity, other contributing factors for the success of impostors were the inability to distinguish between fact and fiction in the flood of reports about newly-discovered lands, the desperate desire of European monarchs to believe in the existence of potential allies against Islam and the eschatological mood bred by the Age of Fear. This article attempts to gauge early modem gullibility by examining the attitudes towards David Reuveni, a self-proclaimed prince from a land of the lost tribes of Israel, who was accepted almost without reservations by Pope, kings and learned cardinals in the 1520s.
The Context of War and Violence in Sixteenth-Century English Society
Authors: Trim David J.B.
Published: June 2008

The Elizabethan epoch has long been regarded as a period in which England, isolated from the rest of Europe, fell behind the Continental powers during an era of "military revolution." More recently, England's sixteenth-century military history has attracted a growing number of scholars, but their conclusions vary widely and seem impossible to integrate. Yet recent analyses have generally been too narrowly focussed on events in Elizabethan England. This article (based on a synthesis of secondary studies, including social and cultural as well as military histories, but supported by evidence from the most important printed primary sources), attempts to put the military history of Tudor England in the setting, firstly of both earlier and later developments in England itself; and secondly, of the wider, contemporaneous experience of warfare in Europe as a whole. An understanding of the context of warfare can provide a better basis for future research into an issue with significant wider implications for early modern historiography.
Challenge To Orthodoxy: Beliefs and Values of the Eternal Mother Sects in Sixteenth-and Seventeenth-Century China
Authors: Shek Richard
Published: June 2008

Using the framework of orthodoxy versus heterodoxy, this paper attempts to establish the following points : (1) An orthodoxy existed in China since the middle of the second century before the common era and lasted until the turn of the present century. (2) This orthodoxy was not articulated by a religious authority, but rather by a political authority. (3) The content of this orthodoxy, socio-political-ethical in emphasis, was defined not by narrow sectarian doctrines but by a compromise consensus among all the major religious traditions in China. (4) Challenge to this orthodoxy was long-lasting and variegated in nature, but at the turn of the sixteenth century crystalized into a potent tradition revolving around a central matriarchal deity and a strong millenarian and eschatological vision. (5) This heterodox tradition, though similarly socio-ethical in content, was by definition also politically subversive and occasionally erupted into anti-dynastic rebellions.
Religion in Contemporary East African Art
Authors: Agthe Johanna
Published: June 2008

This article describes three aspects of religious art in East Africa: firstly it examines the artists' personal attitude to and motivation by the Christian religion; secondly, it looks at Christian and Bible subjects in their paintings; and lastly it considers traditional religion and the newer independent churches as motifs. It draws on interviews with artists, their works in the collection of the Frankfurt Museum für Völkerkunde and a recent unpublished diploma study by Alois Krammer. 1
The Taming of the Prophet Harris
Authors: Shank David A.
Published: June 2008

We have looked at illustrations from a process going from a culture gap in inter-personal contacts, to rapidly scrawled notes—sometimes in a French transcription of heard English, edited in a filled-out synthesis in French, then translated and edited in English, then re-edited and published as a 'full account.' At every stage of the process, one may observe mutations, governed no doubt in large part by the major preoccupation of legitimation of the Wesleyan mission, in all good faith. And it produced the dominant interpretation of the Prophet Harris. The reconstructed message did greatly profit Methodist developments, even though many Harrists could not accept the Wesleyan claim to Harris's authorization of their mission. More important, the Methodists did not stand up as his spokesperson for 'Ethiopian' ways of conjugality ; on the contrary, they used his legitimation to sanction a monogamous discipline. An inherent contradiction was present in that a ministry which they could accept but not fully approve, was used to validate their own. But even more, the Wesleyan Mission clearly did not become a spokesperson for Harris's warnings to the colonial authorities, nor did they wish to seek legitimate authorization for Harris's return ministry in the French colony.37 The consequences of these differences were to have all kinds of implications for the future relationships between Methodists and the Harrists, for whom even today the name and reputation of the white 'Pasteur Benoit' have become ignominious. But in the process, important information was also recorded to permit us to enter into a better understanding of the phenomenal prophet on his own terms, and recognizing—in his own language—that 'God moves in mysterious ways... and uses the foolish things in the world to confound the wise.'38