bluuebunny/crossref_metadata_2025 huggingface dataset:
The blocking probability of spider‐web networks
Authors: Pippenger Nicholas
Published: July 2010

We determine the limiting behavior of the blocking probability for spider‐web networks, a class of crossbar switching networks proposed by Ikeno. We use a probabilistic model proposed by the author, in which the busy links always form disjoint routes through the network. We show that if the occupancy probability is below the threshold 2 ‐ √2 = 0.5857…, then the blocking probability tends to zero, whereas above this threshold it tends to one. This provides a theoretical explanation for results observed empirically in simulations by Bassalygo, Neiman, and Vvedenskaya.
Probabilistic analysis of some distributed algorithms
Authors: Louchard G. , Schott R.
Published: July 2010

In this paper we analyze: (i) a storage allocation algorithm (D.E. Knuth, The Art of Computer Programming‐Vol. I, Addison‐Wesley, Reading, MA, 1969, Ex. 2.2.2.13) which permits one to maintain two stacks inside a shared (continuous) memory area of a fixed size, and (ii) the well‐known banker algorithm which plays a fundamental role in parallel processing (J. Francon, Combinatoire et Parallelisme; Journees Informatique et Mathematique; Lumigny, October 15‐17, 1987; A. N. Habermann, in Current Trends in Programming Methodology, Vol. 3, K. M. Chandy and R. T. Yeh, Eds., Prentice‐Hall, Englewood Cliffs, NJ, 1987; J. Peterson and A. Silberschatz, Operating Systems Concepts, Addison‐Wesley, Reading, MA, 1983). The natural formulation of the problems to be solved here is in terms of random walks. For (i) the random walk Ym(‐) takes place in a triangle in a two‐dimensional lattice space with two reflecting barriers along the axes (a deletion has no effect on an empty stack) and one absorbing barrier along the diagonal (the algorithm stops when the combined sizes of the stacks exhaust the available storage). For (ii) the random walk takes place in a rectangle with broken corner and has four reflecting barriers and one absorbing barrier (see Fig. 10). With the help of diffusion techniques, we obtain, asymptotically as m: →∞.

the distributions of the hitting place (Zm) and hitting time (Tm) on the absorbing boundary.

the joint distribution of Zm and Tm.

the distribution P[Ym(n) ≦ ym, n < Tm].
Limit laws for local counters in random binary search trees
Authors: Devroye Luc
Published: July 2010

Limit laws for several quantities in random binary search trees that are related to the local shape of a tree around each node can be obtained very simply by applying central limit theorems for w‐dependent random variables. Examples include: the number of leaves (Ln), the number of nodes with k descendants (k fixed), the number of nodes with no left child, the number of nodes with k left descendants. Some of these results can also be obtained via the theory of urn models, but the present method seems easier to apply.
Stability of vertices in random boolean cellular automata
Authors: Luczak Tomasz , Cohen Joel E.
Published: July 2010

Based on computer simulations, Kauffman (Physica D, 10, 145‐156, 1984) made several generalizations about a random Boolean cellular automaton which he invented as a model of cellular metabolism. Here we give the first rigorous proofs of two of Kauffman's generalizations: a large fraction of vertices stabilize quickly, consequently the length of cycles in the automaton's behavior is small compared to that of a random mapping with the same number of states; and reversal of the states of a large fraction of the vertices does not affect the cycle to which the automaton moves.
A parallel algorithmic version of the local lemma
Authors: Alon Noga
Published: July 2010

The Lovasz Local Lemma is a tool that enables one to show that certain events hold with positive, though very small probability. It often yields existence proofs of results without supplying any efficient way of solving the corresponding algorithmic problems. J. Beck recently has found a method for converting some of these existence proofs into efficient algorithmic procedures, at the cost of losing a little in the estimates. His method does not seem to be parallelizable. Here we modify his technique and achieve an algorithmic version that can be parallelized, thus obtaining deterministicNClalgorithms for several interesting algorithmic problems.
Colliding stacks: A large deviations analysis
Authors: Maier Robert S.
Published: July 2010

We analyze the performance of a prototypical scheme for shared storage allocation: two initially empty stacks evolving in a contiguous block of memory of size m. We treat the case in which the stacks are more likely to shrink than grow, but with the probabilities of insertion and deletion allowed to depend arbitrarily on stack height as a fraction of m. New results are obtained on the m → ∞ asymptotics of the stack collision time, and of the final stack heights. The results of Wentzell and Freidlin on the large deviations of Markov chains are used, and the relation of their formalism to the Hamiltonian formulation of classical mechanics is emphasized. Certain results on higher‐order asymptotics follow from WKB expansions.
On the inner structure of multidimensional simply generated trees
Authors: Kemp Rainer
Published: July 2010

The well‐known concept of a “simply generated family of trees” is generalized to the multidimensional case. Such trees represent a symbiosis of trees and tries and they essentially arise in the construction of search trees for multidimensional keys. The set of nodes in a d‐dimensional simply generated tree can be partitioned into layers according to the nodes appearing in the ith dimension. We shall present a detailed average‐case analysis of these trees including the number of such trees of given size, the size of the ith layer, and the number of special nodes. The main result is that a multidimensional simply generated tree tends to a structure consisting of a collection of linear chains, on the average; in other words, for large;i ∈ [1: d], the ith layer consists only of one‐node trees.
On classification in presence of measurement errors
Authors: Kolchin V. F.
Published: July 2010

Three algorithms of reconstruction of the true solution of a system of equations in GF(2) with distorted right‐hand sides are considered.
Random graph orders do not satisfy a 0–1 law
Authors: Brightwell Graham
Published: July 2010

The random graph order Pn p is defined by taking a random graph Gn p on vertex set [n], interpreting an edge between vertices i and j, with i <j in [n], as a relation i <j, and taking the transitive closure. We present a first—order property 𝓁 of Pn p such that the limiting probability of 𝓁. is bounded away from both 0 and 1 as n → ∞, whenever pn is bounded away from 0 and p is bounded away from 1. © 1995 John Wiley & Sons, Inc.
On the threshold of chaos in random boolean cellular automata
Authors: Lynch James F.
Published: July 2010

A random boolean cellular automaton is a network of boolean gates where the inputs, the boolean function, and the initial state of each gate are chosen randomly. In this article, each gate has two inputs. Let a (respectively c) be the probability that the gate is assigned a constant function (respectively a noncanalyzing function, i.e., EQUIVALENCE or EXCLUSIVE OR). Previous work has shown that when a>c, with probability asymptotic to 1, the random automaton exhibits very stable behavior: Almost all of the gates stabilize, almost all of them are weak, i.e., they can be perturbed without affecting the state cycle that is entered, and the state cycle is bounded in size. This article gives evidence that the condition a = c is a threshold of chaotic behavior: with probability asymptotic to 1, almost all of the gates are still stable and weak, but the state cycle size is unbounded. In fact, the average state cycle size is superpolynomial in the number of gates.
How to make a random graph irregular
Authors: Tuza Zsolt
Published: July 2010

An irregular edge labeling of a graph G = (V, E) is a weight assignment f: E→ N such that the sums f + (v):= Σv∈e∈E f(e) are pairwise distinct. If such labelings exist in G, then the value of minf Σe∈E (f(e) ‐ 1) measures the minimum number of edges needed to make G irregular. We prove that this minimum for the random graph G(n, p) with n vertices and edge probability p = p(n) is equal to n2/4 + o(n2) as n→∞, whenever p(n)‐n2/3→∞. This asymptotic result is deduced from a general estimate (valid for every graph) involving vertex degrees and the size of largest triangle packings. © 1995 John Wiley & Sons, Inc.
Correlations on the strata of a random mapping
Authors: Drmota Michael
Published: July 2010

Mutafchiev [7] observed that μn(k) the number of points in random mappings on {1,…, n} with distance k to cyclic points is asymptotically identically distributed with the number of cyclic points μn(0) if k = o(√n) by using the fact that (μn(k) ‐ μn(0))√n 0 in probability. The main purpose of this paper is to provide a local limit theorem for the joint distribution of μn(k1), μn(k2). Furthermore, we prove a local version of Mutafchiev's result. All results are obtained by applying singularity analysis of multivariate generating functions.
Sustainable consumption as a means to self‐realization: a Hindu perspective on when enough is enough
Authors: Narayanan Yamini
Published: July 2010

In this paper, I investigate the religious notion of self‐realization or self‐actualization in the context of sustainability, and argue that sustainability is the means to this end. I am particularly interested in Hindu perspectives on self‐realization or the Purusharthas. The Purusharthas provide an interesting sustainability critique because they consider the satisfaction of material want as an important step to self‐actualization; the reconciliation of want and need is a fundamental sustainability tension. The issue of growing want is doubtless an important one, given the rapidly growing middle classes in the developing world that aspire to Western material dreams, as illustrated by the case of Delhi. The Purusharthas may be seen to give consumption legitimacy; however, I argue that it is the selective understanding and institutionalization of the religious message that causes the sustainability problem. Viewed in their entirety, the Purusharthas provide the correct prescriptions for the sustainable enjoyment of want, and take the adherent beyond sustainability into greater transcendence or self‐awareness. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Useful yields of organic molecules under dynamic SIMS cluster bombardment
Authors: Gillen Greg , Szakal Christopher , Brewer Tim M.
Published: July 2010

Useful yields have been measured for a series of organic compounds using Ar+, SF5+ and Bi3+ primary ion bombardment under high dose (>1013 ions/cm2) SIMS sputtering conditions on both magnetic sector and ToF‐SIMS instruments. A precision inkjet deposition system was used to produce well defined arrays of microdrops on silicon with each deposit containing a known number of analyte molecules. The individual deposits were sputtered until consumed while monitoring the integrated characteristic molecular secondary ions for each analyte. The ratio of integrated counts to the number of molecules in the deposit defines the useful yield of the experiment. Measured useful yields varied from 1 × 10−2 to less than 1 × 10−8 depending on the compound examined, the probe beam used and the instrument configuration. Published in 2010 by John Wiley & Sons, Ltd.
Development and application of optical sum frequency microscopy
Authors: Mizutani Goro , Miyauchi Yoshihiro
Published: July 2010

We have developed a microscope for the acquisition of optical sum frequency (SF) intensity images and have observed two types of samples. We have observed resonant electronic and vibrational images of the H‐Si(111) surface in UHV conditions after IR light irradiation of pulse width ∼6 µs. In the resonant SF intensity images, we identified the images of areas covered by SiH species. Nonresonant SF signals appeared in the area irradiated by the IR light pulses, originating from a nonlinear optical transition involving the surface electronic levels in the Si dangling bonds. We also found an unidentified bonding state on the edges of the irradiated area in some light conditions. We have also observed images of a water plant Chara fibrosa by this SF microscope in air. We found that the starch is observed selectively in the oogonium of the water plant and the amylopectin was found to be one of the main ingredients in it. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of surface treatments on interfacial characteristics and band alignments of atomic‐layer‐deposited Al2O3 films on GaAs substrates
Authors: Gong You‐Pin , Li Ai‐Dong , Liu Xiao‐Jie , Zhang Wen‐Qi , Li Hui , Wu Di
Published: July 2010

The GaAs surfaces were passivated by two kinds of chemical pretreatments (using NH4OH and (NH4)2S as passivation agents) for atomic layer deposited (ALD) Al2O3 dielectric film growth. The chemical information at Al2O3/GaAs interfaces was carefully characterized. The impact of surface treatments on the band alignments of ALD Al2O3 films on nGaAs (100) substrates was also investigated. After postdeposition annealing, the NH4OH passivated samples not only have a slight increase of the AsAs peaks with an appearance of As suboxide (AsOx) feature at Al2O3/GaAs interfaces but also exhibit a serious interfacial interdiffusion between Al2O3 and GaAs. However, the (NH4)2S passivated samples produce the GaS and AsS overlayers on GaAs, effectively preventing from the intermixed diffusion between Al2O3 films and GaAs substrates with a sharper interface. Both NH4OH and (NH4)2S passivated Al2O3 samples show the same band gap of 6.67 eV. The conduction band offset at Al2O3/GaAs interface for the (NH4)2S passivated samples have a slight enhancement of 0.14 eV in comparison to NH4OH passivated ones. Copyright © 2010 John Wiley & Sons, Ltd.
ToF‐SIMS analysis of myocardial infarcted tissue
Authors: Park Ji‐Won , Cha Min‐Ji , Kyong Shon Hyun , Kim Se‐Hwa , Lee Tae Geol , Moon Dae Won , Hwang Ki‐Chul
Published: July 2010

Heart tissues from a normal rat, myocardial infarcted rat, and mesenchymal stem cell (MSC)‐treated rat after myocardial infarction (MI) were studied using ToF‐SIMS, with the assistance of principal component analysis (PCA). To our knowledge, this is the first such published study. In PCA results obtained from both positive and negative ion spectra of normal (control), MI, and MSC‐treated MI tissues, the normal and MSC‐treated tissues could be clearly distinguished from the MI tissue in terms of chemical composition. For the MI tissue, fatty acid signals from inside the cell and phosphocholine signals from the cell membrane decreased while glucose signals increased. In the MSC‐treated MI tissue, the signal levels of phosphocholine and fatty acids returned to those for normal tissue. Our observations for myocardium tissues are consistent with previous biological studies, which show that the loss of reversibility of cell injury associated with MI could cause degradation to the cell membrane, and that MI could slow fatty acid uptake and oxidation and increase glucose uptake and utilization for ATP synthesis in myocardium. This is, of course, because fatty acids need oxygen for β‐oxidation. We anticipate that this label‐free ToF‐SIMS method partnered with PCA will be helpful to the investigation of myocardial disease and MSC therapy since it is based on chemical information at the tissue level. Copyright © 2010 John Wiley & Sons, Ltd.
An XPS investigation on glucose oxidase and Ni/Al hydrotalcite interaction
Authors: Addari Danilo , Mignani Adriana , Scavetta Erika , Tonelli Domenica , Rossi Antonella
Published: July 2010

In this work, a Ni/Al hydrotalcite (HT) was used as glucose oxidase (GOx) immobilizer. Small‐area and angle‐resolved X‐ray photoelectron spectra were recorded on HTs electrosynthesized on Pt in the absence and in the presence of GOx, and compared with those obtained for a Pt surface, modified with the electrosynthesized HT, on which a drop of GOx solution was deposited. The simultaneous electrodeposition of HT + GOx resulted in a compact deposit, thicker than the XPS sampling depth (>10 nm), that is not homogeneous in the lateral and in‐depth composition. The presence of GOx can be deduced comparing the N1s spectra of HT and HT + GOx: in the latter, the N1s component at 400 eV binding energy (BE) is predominant whilst, depending on the analyzed point, a small or no contribution from the component at 407.2 eV, due to nitrate, is revealed. Angle‐resolved XPS provides evidence on the in‐depth composition of anions, cations and GOx. The results highlight the crucial role played by nickel in GOx immobilization. On the basis of the results, it can be suggested that enzyme activity is unevenly distributed and is localized in small areas, where Ni concentration is higher. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of vacuum heating in AISI 410 and AISI 321 stainless steels' surface layer revealed by SIMS/GDMS depth profile analysis
Authors: Konarski P. , Kaczorek K. , Senkara J.
Published: July 2010

Vacuum annealing of steels is employed for out‐gassing elements, surface activation and in different production purposes. Such procedure was applied for chromium–nickel AISI 321 and chromium AISI 410 stainless steels used in aviation technologies.

Depth profile analysis of the samples annealed in vacuum for 120 min. in 750 and 950 °C was performed by using two methods: SIMS and glow discharge mass spectrometry (GDMS). SIMS data were obtained with a 5 keV Ar+ ion gun. In GDMS analyzer, d.c. glow discharge was induced by 1.5 kV d.c. voltage in 1 mbar Ar pressure.

Analyses of AISI 321 samples annealed in 750 °C show enrichment of titanium, chromium and manganese in the depth range of 150 nm, and depletion in iron and nickel within this range. The sample treated in 950 °C shows mainly Ti enrichment into 300 nm depth. Vacuum heating of AISI 410 steel sample in 750 °C causes formation of 150‐nm‐thick surface layer enriched in Cr and Mn and depleted in Fe. In turn, 950 °C treatment results in only some increasing of Mn and Ni concentration within 70 nm distance from the surface.

The results obtained by SIMS and GDMS confirm each other. However, higher depth profile resolution was obtained by GDMS due to the lower sputtering energy (1.5 kV glow discharge) and due to the use of multidirectional ion bombardment instead of unidirectional bombardment by ion beam in the SIMS method. Copyright © 2010 John Wiley & Sons, Ltd.
Surface analysis of protein‐resistant, plasma‐polymerized ethylene glycol thin films
Authors: Choi Changrok , Jung Donggeun , Moon Dae Won , Lee Tae Geol
Published: July 2010

Poly(ethylene glycol) (PEG) has been widely used in biomedical applications because of its protein‐resistant and nontoxic properties. In this study, a plasma‐polymerized ethylene glycol (PPEG) thin film was deposited on a substrate using a capacitively coupled plasma chemical vapour deposition (CCP‐CVD) method with various plasma powers and ethylene glycol as a precursor. The surfaces of the PPEG thin films were characterized using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) along with a principal component analysis (PCA), and XPS. We confirmed that the PPEG thin film deposited at low plasma power closely resembles PEG polymers in terms of surface chemical composition and protein‐resistant property. To make patterned surfaces with protein‐resistant property for proteins, a PPEG thin film was first uniformly deposited on a glass slide and patterns were produced on the PPEG coated surface by depositing a plasma‐polymerized amine film through a metal shadow mask. When we spotted proteins on the patterned surface, they were immobilized only onto the plasma‐polymerized amine areas but not onto the PPEG areas. These results show that PPEG surfaces would be useful for the construction of various protein arrays. Copyright © 2010 John Wiley & Sons, Ltd.
ToF‐SIMS and XPS characterization of antimicrobial textiles for the food processing industry
Authors: Brunon Céline , Bessueille François , Grossiord Carol , Chadeau Elise , Oulahal Nadia , Darroux Christine , Ferreira Isabelle , Bourgeois Michel , Simon Farida , Rimbault Fabrice , Yu Caroline , Leonard Didier
Published: July 2010

Textiles for the food processing industry are treated by a patented technology combining an ionic polymer (antimicrobial agent) and a precipitating agent to obtain an insoluble deposit expected to exhibit antimicrobial properties. ToF‐SIMS and XPS are used in the understanding of the surface chemistry at various steps of treatments (cleaning step prior to surface modification, antimicrobial deposit, industrial ISO 15797 washing). ToF‐SIMS and XPS analyses show that the signatures of the antimicrobial treatment are detected at the surface after treatment. After industrial ISO 15797 washings, the precipitating agent is rapidly removed (possibly replaced by washing agent components) while the antimicrobial agent (PHMB) is still detected but is significantly removed from the surface after five washings. ToF‐SIMS and XPS data are compared to microbiological tests specifically intended in relation with food processing industry applications. After the antimicrobial treatment, the surface is biocide as well as after a single ISO 15797 washing, but after 5 washings, either the surface is slightly active (cotton‐based textile) or not active anymore (polyester‐based textile). The XPS N atomic percentage variation is unable to explain this difference. Even though a slight difference is observed for the ToF‐SIMS normalized intensity for m/z = 184.1561 (PHMB molecular peak) between C/P and P/C samples, it can hardly be concluded that this would be the only explanation for the difference in activity. ToF‐SIMS indicates that cotton is the textile component still detected at the surface of the washed samples. This could play a role in the remaining efficiency of the antimicrobial treatment after industrial washing. Copyright © 2010 John Wiley & Sons, Ltd.
Optimization and comparison of depth profiling in GaAs and GaSb with TOF‐SIMS
Authors: Herrmann A. , Lehnhardt T. , Strauß M. , Kamp M. , Forchel A.
Published: July 2010

Depth profile analysis of GaAs/AlGaAs and GaSb/AlGaSb heterostructures was performed by SIMS and optimized with respect to the depth resolution. Different sputter ions like caesium, oxygen and argon were used with various sputter angles and ion energies. SEM images were taken from the sputter craters in order to determine the surface roughness which is correlated to the depth resolution. The best results for both material systems were achieved by using argon ions with 0.5 keV at an angle of 55° towards the sample normal. Copyright © 2010 John Wiley & Sons, Ltd.
Oxygen adsorption on Al (111) surface interstitial site calculated by density functional theory
Authors: Guo Jian‐Xin , Guan Li , Bian Fang , Zhao Qing‐Xun , Wang Ying‐Long , Liu Bao‐Ting
Published: July 2010

The adsorption possibilities of oxygen atoms at Al (111) surface for different oxygen atom coverages (Θ) from 0.25 to 1 ml have been studied using first principles based on density functional theory with generalized gradient approximation. The results show that the interstitial sites on Al (111) surface are relatively stable, in which binding energies are 0.6 ∼ 1 eV/atom lower than those on surface face centered cubic (fcc) sites for the different coverages. The binding energy and work function of the oxygen‐adsorbed surface increase with the oxygen atom coverage. Moreover, the oxygen atom at one tetrahedral site of Al (111) subsurface becomes more and more unstable with the decrease of the coverage, and it moves up to the Al (111) surface hexagonal close packed (hcp) site at Θ = 0.25. All the octahedral absorption sites are also unstable in relatively lower coverages (Θ = 0.5 and 0.25). The bond length and overlap population between Al and O, including the relaxation effects on the oxygen atom coverage are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization and electric field dependence of N,N′‐bis(9H‐fluoren‐9‐ylidene)benzene‐1, 4‐diamine thin film/substrate interface
Authors: Xin Hongliang , Li Zhuomin , He Tianxian , Deng Wenli
Published: July 2010

N,N′‐bis(9H‐fluoren‐9‐ylidene)benzene‐1,4‐diamine deposited onto highly oriented pyrolytic graphite (HOPG) was investigated by contact angle measurement(CAM), Raman spectroscopy and tunneling spectroscopy. The results of CAM and Raman spectra have confirmed that organic layers had deposited on substrate. Tunneling spectra obtained in the scanning tunneling microscopy measurement system were reported as a function of electrode potential. The tunneling current data were acquired at different electrode–electrode separations and depicted significant trend under the action of electric field. Under weak electric fields, the electrode–electrode separation has little effect on the potential of conductance peak. However, with the shrinkage of electrode–electrode separation, the electron transport model obeys the Ohmic law. Copyright © 2010 John Wiley & Sons, Ltd.
Acute and chronic effects of citalopram on 5‐HT1Areceptor—Labeling by [18F]MPPF and—Coupling to receptors‐G proteins
Authors: Moulin‐Sallanon Marcelle , Charnay Yves , Ginovart Nathalie , Perret Pascale , Lanfumey Laurence , Hamon Michel , Hen René , Fagret Daniel , Ibáñez Vicente , Millet Philippe
Published: July 2010

Selective serotonin reuptake inhibitors take several weeks to produce their maximal therapeutic antidepressant effect. This delay has been attributed to the gradual desensitization of somatodendritic serotonin 5‐HT1Aautoreceptors. We evaluated adaptive changes of 5‐HT1Areceptors after acute and chronic citalopram challenges in rat. Small animal positron emission tomography trial and quantitative ex vivo autoradiography studies using [18F]MPPF were employed, as well as in vitro 8‐OH‐DPAT‐stimulated [35S]‐GTPγS binding assay. Additionally, 5‐HT1Areceptor knock‐out mice were used to assess the specificity of [18F]MPPF. Acute treatment with citalopram did not alter [18F]MPPF binding in dorsal raphe nucleus (DR), frontal cortex, or hippocampus. The absence of [18F]MPPF binding in the brain of 5‐HT1Aknock‐out mice demonstrates the specificity of MPPF for 5‐HT1Areceptor brain imaging, but the high affinity of [18F]MPPF compared to 5‐HT suggests that it would only be displaced by dramatic increases in extracellular 5‐HT. Chronic citalopram did not modify 5‐HT1Areceptor density in any of the brain regions studied. In addition, this treatment did not modify 8‐OH‐DPAT‐stimulated [35S]‐GTPγS binding in DR, although a significant increase was observed in frontal cortex and hippocampus. [18F]MPPF appears to be an efficient radioligand to quantify specifically 5‐HT1Areceptor density in brain imaging. The delayed therapeutic efficacy of citalopram did not appear to be linked to either a downregulation of 5‐HT1Areceptors or to a 5‐HT1Areceptor‐G protein decoupling process in serotonergic neurons, but to increased functional sensitivity of postsynaptic 5‐HT1Areceptors. Synapse 63:106–116, 2009. ©2008 Wiley‐Liss, Inc.
Anti‐Retroviral Protease Inhibitors ‐ ‘A Two Edged Sword?’
Authors: Germinario Ralph J.
Published: July 2010

The use of anti‐retroviral protease inhibitors in combination with nucleoside analog or non nucleoside reverse transcriptase inhibitors (HAART) has led to dramatic decreases in the mortality seen with HIV infected patients. In concert with these treatment regimens, especially with the inclusion of the anti‐retroviral protease inhibitors (PI), a complex series of metabolic complications occurred. These included alterations of fat and carbohydrate metabolism. In some patients, one could observe either lipoatrophy (fat wasting) as well as lipohypertrophy (fat deposition) or both. The problem is that the lack of a case definition of the altered fat metabolism confuses diagnoses. In vitro, interference with fat cell differentiation has been demonstrated by PI. Further, in vitro studies demonstrate that indinavir, a PI currently used in HIV tretment, can interact with the insulin responsive glucose transporter (GLUT4). The activity of the GLUT4 is inhibited by indinavir and eventual insulin resistance has been shown (i.e. in vivo and in vitro). Also, controversy exists regarding insulin signaling in fat cells. Finally, the relationships between hyperlipidemia and/or lipolysis and altered carbohydrate metabolism (i.e. mild glucose intolerance, insulin resistance) suggest an association with cardiovascular risk in protease treated patients (Metabolic Syndrome X). In short, while multiple problems exist, no one mechanism can account for the changes observed.
Plant Peroxisomes, Reactive Oxygen Metabolism and Nitric Oxide
Authors: Del Río Luis A. , Corpas F. Javier , Sandalio Luisa M. , Palma José M. , Barroso Juan B.
Published: July 2010

In plant cells, as in most eukaryotic organisms, peroxisomes are probably the major sites of intracellular H2O2 production, as a result of their essentially oxidative type of metabolism. Like mitochondria and chloroplasts, peroxisomes also produce superoxide radicals (O2.−) and there are, at least, two sites of superoxide generation: one in the organelle matrix, the generating system being xanthine oxidase, and another site in the peroxisomal membranes dependent on NAD(P)H. In peroxisomal membranes, three integral polypeptides (PMPs) with molecular masses of 18, 29, and 32 kDa have been shown to generate O2.− radicals. Besides catalase, several antioxidative systems have been demonstrated in plant peroxisomes, including different superoxide dismutases, the four enzymes of the ascorbate‐glutathione cycle plus ascorbate and glutathione, and three NADP‐dependent dehydrogenases. A CuZn‐SOD and two Mn‐SODs have been purified and characterized from different types of plant peroxisomes. The presence of the enzyme nitric oxide synthase (NOS) and its reaction product, nitric oxide (NO.), has been recently demonstrated in plant peroxisomes. Different experimental evidence has suggested that peroxisomes have a ROS‐mediated cellular function in leaf senescence and in stress situations induced by xenobiotics and heavy metals. Peroxisomes could also have a role in plant cells as a source of signal molecules like NO., O2.− radicals, H2O2, and possibly S‐nitrosoglutathione (GSNO). It seems reasonable to think that a signal molecule‐producing function similar to that postulated for plant peroxisomes could also be performed by human, animal and yeast peroxisomes, where research on oxy radicals, antioxidants and nitric oxide is less advanced than in plant peroxisomes.
Synthesis, Characterization, and Crystal Structure of Dinuclear Diorganotin(IV) Complexes Derived from Pyruvic Acid Picolinoacylhydrazone
Authors: Cui Jichun , Qiao Yanling , Yin Handong , Liu Ming
Published: July 2010

Three new diorganotin(IV) derivatives of pyruvic acid picolinoacylhydrazone, {Me2Sn[(2‐C5H4N)CONHNC(CH3)COO]}2·MeOH(1), {nBu2Sn[(2‐C5H4N)CONHNC(CH3)COO]}2 (2), and {Ph2Sn[(2‐C5H4N)CONHNC(CH3)COO]}2 (3) were synthesized by the reaction of Me2SnCl2, nBu2SnCl2, and Ph2SnCl2 with pyruvic acid picolinoacylhydrazone, respectively in the presence of sodium ethoxide. The prepared compounds were characterized by elemental analysis, IR, and 1H, 13C, and 119Sn NMR spectroscopy. Compounds 1 and 2 were also characterized by X‐ray diffraction analysis, which revealed that the compounds have similar structures containing two‐center‐two‐ligand skeletons. Furthermore, weak but significant intermolecular hydrogen bonds assemble these compounds into 1D or 2D supramolecular frameworks.
In vitro Effectiveness of Garlic (Allium sativum) Extract on Scolices of Hydatid Cyst
Authors: Moazeni Mohammad , Nazer Ali
Published: July 2010

Background

Surgery is still the main treatment for hydatid disease. Recurrence of the infection is one of the end points of surgery in treating the hydatid cyst which results from the dissemination of protoscolices‐rich fluid. Installation of a scolicidal agent into the cyst is the most commonly employed measure to prevent recurrence. Many scolicidal agents have been used for inactivation of the cyst’s content, but most of them are not safe due to their undesired side effects. In the present study, the scolicidal effect of methanolic extract of Allium sativum is investigated.

Methods

Protoscolices were aseptically collected from sheep livers containing hydatid cysts. Two concentrations (25 and 50 mg ml−1) of garlic extract were used for 10, 20, 30, 40, 50, and 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining.

Results

Allium sativum extract at the concentration of 25 mg ml−1 killed 87.9, 95.6, 96.8, 98.7, 99.6, and 100% of protoscolices following 10, 20, 30, 40, 50, and 60 min of application, respectively. Moreover, the scolicidal activity of Allium sativum extract at the concentration of 50 mg ml−1 was 100% after 10 min of application.

Conclusions

Methanolic extract of Allium sativum had a high scolicidal activity in vitro and thus might be used as a scolicidal agent in the surgical treatment of the hydatid cyst. However, further investigation on the in vivo efficacy of Allium sativum extract and its possible side effects is proposed.
Repletion of n‐3 Fatty Acid Deficient Dams with α‐Linolenic Acid: Effects on Fetal Brain and Liver Fatty Acid Composition
Authors: Harauma Akiko , Salem Norman , Moriguchi Toru
Published: July 2010

Docosahexaenoic acid (DHA) supply to the fetal brain depends upon the dam's dietary intake of n‐3 fats. In this study, we measured the incorporation of DHA into the fetal brain and liver in n‐3 fatty acid deficient (0.1% alpha‐linolenate) mice upon switching to an n‐3 fatty acid adequate (2.1% alpha‐linolenate) diet. Second generation mice raised and maintained on an n‐3 deficient diet during mating were switched to an n‐3 adequate diet on embryonic day 1 (ED 1) or ED 13. Fatty acid analysis was performed on fetal brains and livers and on maternal serum on ED 13, 15, 17, and 19. Although fetal brain and liver DHA began at a very low level (both exhibited an 85% decline), recovery was nearly complete by ED 15 in the group switched near conception but thereafter diverged. The maternal serum and fetal liver were very similar in their DHA and docosapentaenoic acid time courses. However, when repletion began on ED 13, brain DHA recovery was only about 44%. These results suggest that a nutritional intervention with alpha‐linolenic acid can nearly but incompletely rescue the mouse fetal DHA deficiency if began at the time of conception but that the third trimester is too late, thus leaving a large DHA gap.
The Complex and Important Cellular and Metabolic Functions of Saturated Fatty Acids
Authors: Legrand Philippe , Rioux Vincent
Published: July 2010

This review summarizes recent findings on the metabolism and biological functions of saturated fatty acids (SFA). Some of these findings show that SFA may have important and specific roles in the cells. Elucidated biochemical mechanisms like protein acylation (N‐myristoylation, S‐palmitoylation) and regulation of gene transcription are presented. In terms of physiology, SFA are involved for instance in lipogenesis, fat deposition, polyunsaturated fatty acids bioavailability and apoptosis. The variety of their functions demonstrates that SFA should no longer be considered as a single group.
The significance of the wall echo shadow triad on ultrasonography: a case series
Authors: Datta Anita , Garg Nidhi , Lema Penelope Chun
Published: July 2010

Background

The wall echo shadow (WES) triad, also known as the double-arc-shadow sign consists of a well-defined near wall, echos from stones immediately beneath the wall, and posterior shadowing caused by strong echoes from stones in the gallbladder fossa. It has been used for over 20 years as a nonspecific finding suggestive of a gallbladder lumen filled with either multiple stones or one large stone (Miller et al. J Emerg Med 30(1):69–74, 2006; Blaivas et al. Acad Emerg Med 10(6):1020–1023, 1999; Raptopoulos et al. AJR Am J Roentgenol 138(2):275–278, 1982). In the past, the WES triad has been correlated with underlying chronic cholecystitis. However, there are no studies that compare clinical findings to a gold standard such as surgical pathology.

Case reports

Three cases of the WES triad were reviewed at New York Medical Hospital of Queens over a 16-month period.
Pain processing in multisensory environments
Authors: Höfle Marion , Hauck M. , Engel A.K. , Senkowski D.
Published: July 2010

“Don’t look and it won’t hurt” is common ad­vice heard before receiving an injection, but is there any truth in this statement? Pain pro­cessing can be separated into two major components: a sensory-discriminative com­ponent, which reflects the location and inten­sity of a painful event, and an affective-mo­tivational component that reflects the un­pleasantness of pain. The differentiation be­tween these components and the effects of additional sensory inputs on them becomes apparent if you watch a needle penetrating your skin: On the one hand, it may be some­what reassuring to know precisely when and where to expect the pinprick, on the other hand, you eye-witness damage inflicted on your body, which can increase personal dis­tress. Here we review recent studies, which demonstrate that a host of variables such as onset timing, spatial alignment, semantic meaning, and attention differentially affect how visual inputs influence pain processing. These studies also indicate that there is some truth in the opening statement.
Intracellular ion homeostasis
Authors: Kelly T. , Rose C.R.
Published: July 2010

Hepatic encephalopathy (HE) is a neuropsy­chiatric disorder associated with acute and chronic liver failure. Ammonium is the most likely toxin responsible for the observed neu­rological deficits, reaching 5 mM in the CNS during acute HE. Additionally, ammonium preferentially affects astrocytes. Conversion of glutamate to glutamine, occurring exclu­sively in astrocytes, is the sole pathway for ammonium detoxification, while glutamine increases in astrocytes during HE. Further­more, elevated extracellular glutamate con­centrations, commonly observed in HE pa­tients, may result from reduced glutamate uptake into astrocytes. Finally, astrocytic swelling likely contributes to brain oedema, the predominant cause of mortality following acute liver failure. Alterations in intracellu­lar ion concentrations may contribute to the observed cellular changes in HE. Ammoni­um causes intracellular acidifications, and in­creases intracellular calcium and sodium con­centrations in astrocytes. In this review, we summarise current knowledge concerning ammonium-evoked changes in ion homeo­stasis, and discuss how such changes possibly contribute to the pathology of HE.
Exact reconstruction of damaged color images using a total variation model
Authors: Leoni G. , Maggi F. , Morini M. , Fonseca I.
Published: July 2010

In this paper the reconstruction of damaged piecewice constant color images is studied using an RGB total variation based model for colorization/inpainting. In particular, it is shown that when color is known in a uniformly distributed region, then reconstruction is possible with maximal fidelity.
Upregulation of Bcl2 inhibits apoptosis‐driven BAX insertion but favors BAX relocalization in mitochondria
Authors: Teijido O. , Dejean L.
Published: July 2010

MINT‐7945271: BAX (uniprotkb:Q07813) physically interacts (MI:0915) with Bcl‐2 (uniprotkb:P10417) by anti bait coimmunoprecipitation (MI:0006)
Direct interaction and functional coupling between voltage‐gated CaV1.3 Ca2+ channel and GABAB receptor subunit 2
Authors: Park Hye-Won , Jung Hana , Choi Kee-Hyun , Baik Ja-Hyun , Rhim Hyewhon
Published: July 2010

MINT‐7966026: GABABR2 (uniprotkb:O88871) and Cav1.3 (uniprotkb:P27732) colocalize (MI:0403) by fluorescence microscopy (MI:0416)
Atypical event‐related potentials in patients with mild cognitive impairment: An identification‐priming study
Authors: Galli Giulia , Ragazzoni Aldo , Viggiano Maria Pia
Published: July 2010

Background

Our goal was to verify whether behavioral and electrophysiological measures of visual object priming can differentiate between patients with mild cognitive impairment (MCI) and elderly control subjects.

Methods

An identification‐priming paradigm with spatially filtered stimuli was used. Subjects were presented with complete forms of the stimuli in the study phase. In the subsequent test phase, studied items were repeated in an ascending sequence of spatially filtered stimuli, following a coarse‐to‐fine order. Event‐related potentials and behavioral measures were recorded.

Results

Behavioral priming effects were observed in the elderly and in MCI participants. None of the well‐known event‐related potential indices of stimulus repetition emerged in the MCI group. In elderly controls, stimulus repetition was associated with a frontal modulation, likely indexing familiarity. Priming effects in the MCI group were probably based on memory mechanisms altered by degenerative pathology.

Conclusions

Event‐related potentials hold great potential for the early detection of subjects at risk for dementia, because they may reveal possible functional brain abnormalities that are not detectable at clinical or behavioral levels.
The boundary spanning capabilities of purchasing agents in buyer–supplier trust development
Authors: Zhang Chun , Viswanathan Sridhar , Henke John W.
Published: July 2010

This study examines how individual purchasing agents function as boundary spanners with suppliers to influence trust development in themselves and the buying firms that employ them. Building upon boundary theory and supply chain cooperation research, we identify three boundary spanning capabilities of purchasing agents and empirically test how these capabilities shape buyer–supplier trust development. Using two samples of data collected from suppliers in the automotive industry and food industry, we found that a purchasing agent's effectiveness in strategic communication with suppliers affects a supplier's trust in the buying firm, while an agent's professional knowledge and ability to reach compromises with suppliers affect a supplier's trust in the purchasing agent representing the firm. Trust in the purchasing agent in turn affects trust in the buying firm. Theoretical and managerial implications are discussed.
Reproducibility and validity of bioimpedance spectroscopy for tracking changes in total body water: implications for repeated measurements
Authors: Moon Jordan R. , Stout Jeffrey R. , Smith Abbie E. , Tobkin Sarah E. , Lockwood Christopher M. , Kendall Kristina L. , Graef Jennifer L. , Fukuda David H. , Costa Pablo B. , Stock Matt S. , Young Kaelin C. , Tucker Patrick S. , Kim Eonho , Herda Trent J. , Walter Ashley A. , Ferguson Steven L. , Sherk Vanessa D. , Cramer Joel T.
Published: July 2010

Bioimpedance spectroscopy (BIS) has been used to track changes in total body water (TBW). Accurate TBW estimations can be influenced by both methodological and biological factors. One methodological variation that contributes to BIS TBW errors is the electrode placement. The purpose of the present study was to compare the reproducibility and validity of fixed-distance electrode placements (5 cm) with the standard single-site electrode placements. Twenty-nine subjects (fifteen men and fourteen women) participated in the reproducibility study, while sixty-nine subjects (thirty-three men and thirty-six women) participated in the validity study. The reproducibility study included two measurements that were taken 24 h apart, while the validity study consisted of a 12-week exercise intervention with measurements taken at weeks 1 and 12. TBW was estimated using BIS and2H techniques. Reproducibility results indicated that fixed-distance electrodes reduced the day-to-day standard error of the measurement in men (from 1·13 to 0·81 litres) but not in women (0·47 litres).semvalues were lower for women than for men, suggesting that BIS TBW estimates are sex dependent. Validity results produced similar accurate findings (mean difference < 0·21 litres). However, fixed-distance electrodes improved delta TBW errors (mean difference improvements>0·04 litres in men, women, and men and women combined). When tracking changes in TBW, fixed-distance electrodes may reduce reproducibility errors and allow for smaller changes to be detected. However, the reduction of reproducibility errors may be greater for men than for women. Therefore, reproducibility calculations should be based on the sex of the sample population.
Taxonomic resolution in parasite community studies: are things getting worse?
Authors: POULIN R. , LEUNG T. L. F.
Published: July 2010

Species identification is crucial for studies of parasite diversity, yet most surveys include taxa identified only to genus or family level. Using a large dataset comprising 950 surveys of helminth communities from 650 different species of fish, bird and mammal hosts, we investigated what determines the level of taxonomic resolution achieved. Identification of all helminths down to species level was achieved in only one-third of surveys, whereas all taxa were identified at least to genus level in two-thirds of surveys. The species richness of a parasite community and past study effort on the host species did not correlate with taxonomic resolution. However, the higher the proportion of parasite taxa occurring as larvae in a community, the lower the resolution achieved. Also, taxonomic resolution was better overall for communities in birds or mammals than for those in fish, and better for trematodes and acanthocephalans than for cestodes and nematodes. Perhaps the most intriguing result was a clear significant effect of year of publication on the taxonomic resolution achieved in parasite surveys: the proportion of helminth taxa identified at least to genus level has remained high until the year 2000, but has dropped in studies published since then. The loss of expertize in parasite taxonomy happening worldwide is one possible explanation. This downward trend needs to be reversed if we are to monitor new parasite occurrences in the face of environmental changes.
More on moral critique of theodicies: reply to Robert Simpson
Authors: SØVIK ATLE OTTESEN
Published: July 2010

The article discusses moral critique of theodicies, and suggests the need for several distinctions in order to avoid misunderstanding. It distinguishes between moral critique of concrete theodicies and theodicies in general, and between moral critique of the content of theodicies and the consequences of theodicies. But there are also different kinds of moral critique of the content and the consequences. After presenting these distinctions, the article responds to Robert Simpson's ‘Some moral critique of theodicies is misplaced, but not all’.
A study of the role of user-centered design methods in design team projects
Authors: Lai Justin , Honda Tomonori , Yang Maria C.
Published: July 2010

User-centered approaches to design can guide teams toward an understanding of users and aid teams in better posing design problems. This paper investigates the role of user-centered design approaches in design process and outcome within the context of design team projects. The value of interaction with users is examined at several stages throughout the design process. The influence of user-centered design on the performance of design teams is also explored. Results suggest that the quantity of interactions with users and time spent interacting with users alone is not linked with better design outcome, but that iterative evaluation of concepts by users may be of particular value to design prototypes. Suggestions are made based on the reflections from the authors after conducting this study.