bluuebunny/crossref_metadata_2025 huggingface dataset:
AUTOMATIC SERVICE COMPOSITION VIA SIMULATION
Authors: BERARDI DANIELA , CHEIKH FAHIMA , DE GIACOMO GIUSEPPE , PATRIZI FABIO
Published: April 2008

In this paper we study the issue of service composition, for services that export a representation of their behavior in the form of a finite deterministic transition system. In particular, given a specification of the target service requested by the client as a finite deterministic transition system, the problem we face is how we can exploit the computations of the available services for realizing the computations of the target service. While ways to tackle such a problem are known, in this paper we present a new technique that is based on the notion of simulation, which is still optimal from the computational complexity point. Notably, such a technique, opens up the possibility of devising composition in a "just-in-time" fashion. Indeed, we show that, by exploiting simulation, it is actually possible to implicitly compute all possible compositions at once, and delay the choice of the actual composition to run-time.
Enhanced exocytotic-like insertion of Orai1 into the plasma membrane upon intracellular Ca2+ store depletion
Authors: Woodard Geoffrey E. , Salido Ginés M. , Rosado Juan A.
Published: April 2008

Ca+ release-activated Ca2+ (CRAC) channels are activated when free Ca2+ concentration in the intracellular stores is substantially reduced and mediate sustained Ca2+ entry. Recent studies have identified Orai1 as a CRAC channel subunit. Here we demonstrate that passive Ca2+ store depletion using the inhibitor of the sarcoendoplasmic reticulum Ca2+-ATPase, thapsigargin (TG), enhances the surface expression of Orai1, a process that depends on rises in cytosolic free Ca2+ concentration, as demonstrated in cells loaded with dimethyl BAPTA, an intracellular Ca2+ chelator that prevented TG-evoked cytosolic free Ca2+ concentration elevation. Similar results were observed with a low concentration of carbachol. Cleavage of the soluble N-ethylmaleimide-sensitive-factor attachment protein receptor, synaptosomal-assiciated protein-25 (SNAP-25), with botulinum neurotoxin A impaired TG-induced increase in the surface expression of Orai1. In addition, SNAP-25 cleaving by botulinum neurotoxin A reduces the maintenance but not the initial stages of store-operated Ca2+ entry. In aggregate, these findings demonstrate that store depletion enhances Orai1 plasma membrane expression in an exocytotic manner that involves SNAP-25, a process that contributes to store-dependent Ca2+ entry.
Induction of Na+/K+/2Cl− cotransporter expression mediates chronic potentiation of intestinal epithelial Cl− secretion by EGF
Authors: O'Mahony Fiona , Toumi Ferial , Mroz Magdalena S. , Ferguson Gail , Keely Stephen J.
Published: April 2008

Alterations in EGF receptor (EGFR) signaling occur in intestinal disorders associated with dysregulated epithelial transport. In the present study, we investigated a role for the EGFR in the chronic regulation of intestinal epithelial secretory function. Epithelial Cl− secretion was measured as changes in short-circuit current ( Isc) across voltage-clamped monolayers of T84 cells in Ussing chambers. Acute treatment of T84 cells with EGF (100 ng/ml, 15 min) chronically enhanced Isc responses to a broad range of secretagogues. This effect was apparent within 3 h, maximal by 6 h, and sustained for 24 h after treatment with EGF. The Na+/K+/2Cl− cotransporter (NKCC1) inhibitor bumetanide (100 μM) abolished the effect of EGF, indicating increased responses are due to potentiated Cl− secretion. Neither basal nor agonist-stimulated levels of intracellular Ca2+ or PKA activity were altered by EGF, implying that the effects of the growth factor are not due to chronic alterations in levels of second messengers. EGF increased the expression of NKCC1 with a time course similar to that of its effects on Cl− secretion. This effect of EGF was maximal after 6 h, at which time NKCC1 expression in EGF-treated cells was 199.9 ± 21.9% of that in control cells ( n = 21, P < 0.005). EGF-induced NKCC1 expression was abolished by actinomycin D, and RT-PCR analysis demonstrated EGF increased expression of NKCC1 mRNA. These data increase our understanding of mechanisms regulating intestinal fluid and electrolyte transport and reveal a novel role for the EGFR in the chronic regulation of epithelial secretory capacity through upregulation of NKCC1 expression.
Acute alcohol intoxication increases atrogin-1 and MuRF1 mRNA without increasing proteolysis in skeletal muscle
Authors: Vary Thomas C. , Frost Robert A. , Lang Charles H.
Published: April 2008

Acute alcohol intoxication decreases muscle protein synthesis, but there is a paucity of data on the ability of alcohol to regulate muscle protein degradation. Furthermore, various types of atrophic stimuli appear to regulate ubiquitin-proteasome-dependent proteolysis by increasing the muscle-specific E3 ligases atrogin-1 and MuRF1 (i.e., “atrogenes”). Therefore, the present study was designed to test the hypothesis that acute alcohol intoxication increases atrogene expression leading to an elevated rate of muscle protein breakdown. In male rats, the intraperitoneal injection of alcohol dose- and time-dependently increased atrogin-1 and MuRF1 mRNA in gastrocnemius, the latter of which was most pronounced. A comparable change was absent in the soleus and heart. The ability of in vivo-administered ethanol to increase atrogene expression was independent of the route of alcohol administration (intraperitoneal vs. oral), as well as of nutritional status (fed vs. fasted) and gender (male vs. female). The increase in atrogin-1 and MuRF1 was independent of alcohol metabolism, and the overproduction of endogenous glucocorticoids and could not be prevented by maintaining the circulating concentration of insulin-like growth factor-I. Despite marked changes in atrogene expression, acute alcohol in vivo did not alter the release of either 3-methylhistidine (MH) or tyrosine from the isolated perfused hindlimb, suggesting that the rate of muscle proteolysis remains unchanged. Moreover, alcohol did not increase the directly determined rate of protein degradation in isolated epitrochlearis muscles or cultured myocytes. Finally, no increase in atrogene expression or 3-MH release was detected in muscle from rats fed an alcohol-containing diet. Our results indicate that although acute alcohol intoxication increases atrogin-1 and MuRF1 mRNA preferentially in fast-twitch skeletal muscle, this change was not associated with increased rates of muscle proteolysis. Therefore, the loss of muscle mass/protein in response to chronic alcohol abuse appears to result primarily from a decrement in muscle protein synthesis, not an increase in degradation.
Effect of renal denervation on prenatal programming of hypertension and renal tubular transporter abundance
Authors: Dagan Amit , Kwon H. Moo , Dwarakanath Vangipuram , Baum Michel
Published: April 2008

Prenatal glucocorticoids are often administered to pregnant women to accelerate pulmonary maturation. We have demonstrated that administration of dexamethasone during specific periods of pregnancy in the rat causes hypertension in the offspring when they are studied as adults. The purpose of the present study was to determine whether the hypertension due to prenatal dexamethasone was mediated by renal nerves. We administered dexamethasone to rats daily for 4 days between days 15 and 18 of gestation. Rats underwent bilateral renal denervation or sham operation at 6 wk of age, and blood pressure was measured at 8 wk of age. Prenatal dexamethasone in the sham operation group resulted in an increase in blood pressure compared with vehicle-treated sham controls (134 ± 3 vs. 145 ± 3 mmHg, P < 0.05). Renal denervation did not affect blood pressure significantly in the prenatal vehicle-treated control group but resulted in normalization in blood pressure in the prenatal dexamethasone group and (130 ± 3 and 128 ± 5 mmHg, respectively). Prenatal dexamethasone increased type 3 Na+/H+ exchanger (NHE3), Na+-K+-2Cl− cotransporter (NKCC2), and Na+-Cl− cotransporter (NCC), but not α-, β-, and γ-epithelial Na+ channel (ENaC) protein abundance compared with controls. The increase in NHE3, NKCC2, and NCC protein abundance by prenatal dexamethasone was not seen in 8-wk-old rats 2 wk after renal denervation. Renal denervation did not affect NHE3, NKCC2, and NCC protein abundance in prenatal vehicle-treated animals. This study is consistent with renal nerves playing a role in mediating the hypertension by prenatal programming by dexamethasone.
Exploring mechanisms involved in renal tubular sensing of mechanical stretch following ureteric obstruction
Authors: Quinlan Mark R. , Docherty Neil G. , Watson R. William G. , Fitzpatrick John M.
Published: April 2008

Tubular mechanical stretch is the key primary insult in obstructive nephropathy. This review addresses how the renal tubular epithelium senses and responds to mechanical stretch. Using data from renal and nonrenal systems, we describe how sensing of stretch initially occurs via the activation of ion channels and subsequent increases in intracellular calcium levels. Calcium influxes activate a number of adaptive and proinjury responses. Key among these are 1) the activation of Rho, consequent cytoskeletal rearrangements, and downstream increases in focal adhesion assembly; and 2) phospholipase activation and resultant mitogen-activated protein kinase activation. These early signaling events culminate in adaptive cellular coupling to the extracellular matrix, a process termed the cell strengthening response. Direct links can be made between increased expression of genes involved in the development of obstructive nephropathy and initial sensing of mechanical stretch. The review illustrates the repercussions of mechanical stretch as a renal stress stimulus, specific to ureteric obstruction, and provides an insight into how tubular responses to mechanical stretch are ultimately implicated in the development of obstructive nephropathy.
Computational Role of Large Receptive Fields in the Primary Somatosensory Cortex
Authors: Foffani Guglielmo , Chapin John K. , Moxon Karen A.
Published: April 2008

Computational studies are challenging the intuitive view that neurons with broad tuning curves are necessarily less discriminative than neurons with sharp tuning curves. In the context of somatosensory processing, broad tuning curves are equivalent to large receptive fields. To clarify the computational role of large receptive fields for cortical processing of somatosensory information, we recorded ensembles of single neurons from the infragranular forelimb/forepaw region of the rat primary somatosensory cortex while tactile stimuli were separately delivered to different locations on the forelimbs/forepaws under light anesthesia. We specifically adopted the perspective of individual columns/segregates receiving inputs from multiple body location. Using single-trial analyses of many single-neuron responses, we obtained two main results. 1) The responses of even small populations of neurons recorded from within the same estimated column/segregate can be used to discriminate between stimuli delivered to different surround locations in the excitatory receptive fields. 2) The temporal precision of surround responses is sufficiently high for spike timing to add information over spike count in the discrimination between surround locations. This surround spike-timing code (i) is particularly informative when spike count is ambiguous, e.g., in the discrimination between close locations or when receptive fields are large, (ii) becomes progressively more informative as the number of neurons increases, (iii) is a first-spike code, and (iv) is not limited by the assumption that the time of stimulus onset is known. These results suggest that even though large receptive fields result in a loss of spatial selectivity of single neurons, they can provide as a counterpart a sophisticated temporal code based on latency differences in large populations of neurons without necessarily sacrificing basic information about stimulus location.
NMDA Receptor Desensitization Regulated by Direct Binding to PDZ1-2 Domains of PSD-95
Authors: Sornarajah Lavan , Vasuta Oana Cristina , Zhang Lily , Sutton Christine , Li Bo , El-Husseini Alaa , Raymond Lynn A.
Published: April 2008

Regulation of N-methyl-d-aspartate receptor (NMDAR) activity by desensitization is important in physiological and pathological states; NMDAR desensitization contributes in shaping synaptic responses and may be protective by limiting calcium influx during sustained glutamate insults. We previously reported that glycine-independent desensitization decreases during hippocampal neuronal development, correlating with NMDAR synaptic localization and association with postsynaptic density 95 (PSD-95). PSD-95/Discs large/zona occludens (PDZ)-1,2 domains of PSD-95 bind to the C-terminus of NMDAR NR2 subunits. The role of PSD-95 in anchoring signaling proteins near NMDARs is well documented. To determine if PSD-95-induced changes in NMDAR desensitization occur because of direct binding to NR2 or due to recruitment of regulatory proteins, we tested the effects of various PSD-95 constructs on NMDAR currents in human embryonic kidney 293 (HEK293) cells and neurons. In HEK cells, wild-type PSD-95 significantly reduced wild-type NMDAR desensitization without altering currents of NMDARs containing NR2A-S1462A, a mutation that abolishes PSD-95 binding. The PSD-95 N-terminus truncated after the PDZ1-2 domains was sufficient for this effect in neurons with low endogenous PSD-95 levels; in NMDAR-expressing HEK cells, the effect persisted when PSD-95 multimerization was eliminated. Moreover other PSD-95 family members with highly homologous PDZ1-2 domains significantly reduced NMDAR desensitization. In mature neurons, disruption of PSD-95/NMDAR interaction through protein kinase C (PKC) activation increased desensitization to levels found in immature neurons, and this effect was not due to PKC direct regulation of NMDAR activity. We conclude that direct binding of PSD-95 increases stability of NMDAR responses to agonist exposure in neuronal and nonneuronal cells.
Quality‐of‐Service Routing Using Path and Power Aware Techniques in Mobile Ad Hoc Networks
Authors: Asokan R. , Natarajan A. M. , Venkatesh C.
Published: April 2008

Mobile ad hoc network (MANET) is a collection of wireless mobile hosts dynamically forming a temporary network without the aid of any existing established infrastructure. Quality of service (QoS) is a set of service requirements that needs to be met by the network while transporting a packet stream from a source to its destination. QoS support MANETs is a challenging task due to the dynamic topology and limited resources. The main objective of this paper is to enhance the QoS routing for MANET using temporally ordered routing algorithm (TORA) with self‐healing and optimized routing techniques (SHORT). SHORT improves routing optimality by monitoring routing paths continuously and redirecting the path whenever a shortcut path is available. In this paper, the performance comparison of TORA and TORA with SHORT has been analyzed using network simulator for various parameters. TORA with SHORT enhances performance of TORA in terms of throughput, packet loss, end‐to‐end delay, and energy.
Multidisciplinary Optimization of Aerocapture Maneuvers
Authors: Armellin Roberto , Lavagna Michèle
Published: April 2008

A multidisciplinary‐multiobjective optimization of aerocapture maneuvers is presented. The proposed approach allows a detailed analysis of the coupling among vehicle′s shape, trajectory control, and thermal protection system design. A set of simplified models are developed to address this analysis and a multiobjective particle swarm optimizer is adopted to obtain the set of Pareto optimal solutions. In order to deal with an unconstrained multiobjective optimization, a two‐point boundary value problem is formulated to implicitly satisfy the constraints on the atmospheric exit conditions. The trajectories of the most promising solutions are further optimized in a more refined dynamical system by solving an optimal control problem using a direct multiple shooting transcription method. Furthermore, a more complete vehicle control is considered. All the simulations presented consider an aerocapture at Mars with a polar orbit of 200 km of altitude as target orbit.
The Effect of Sulphate Doping on Nanosized TiO2 and MoOx/TiO2 Catalysts in Cyclohexane Photooxidative Dehydrogenation
Authors: Ciambelli P. , Sannino D. , Palma V. , Vaiano V.
Published: April 2008

The effect of sulphate doping of titania in promoting activity and selectivity of MoOx/TiO2 catalysts for the cyclohexane photooxidative dehydrogenation has been investigated in a gas‐solid fluidized bed reactor. Sulphate and/or molybdate‐modified titania catalysts were prepared by incipient wet impregnation of nanosized (5–10 nm crystallite size) samples. At 60% of titania surface coverage
by MoOx, sulphate surface density was obtained up to 19 μmol/m2 without formation of MoO3. The catalysts were characterized by N2 adsorption‐desorption at −196∘C, micro‐Raman and UV‐visible reflectance spectroscopy, thermogravimetric analysis coupled with mass spectroscopy (TG‐MS), and mass titration. Unsulphated and sulphated titania are both active in cyclohexane total oxidation, but sulphate doping of titania has a detrimental effect on the reaction rate. On Mo‐based catalysts, polymolybdate species enabled sulphated titania to convert cyclohexane to benzene (99% selectivity) and cyclohexene, reducing at zero the formation of CO2. Cyclohexane conversion to benzene is almost linearly dependent on sulphate surface density, resulting in enhanced yield to benzene. The enhanced photooxidative dehydrogenation activity and benzene yield by sulphate doping could be attributed to the increase of surface acidity and, as a consequence, of cyclohexane adsorption.
Novel Anticancer Platinum(IV) Complexes with Adamantylamine: Their Efficiency and Innovative Chemotherapy Strategies Modifying Lipid Metabolism
Authors: Kozubík Alois , Vaculová Alena , Souček Karel , Vondráček Jan , Turánek Jaroslav , Hofmanová Jiřina
Published: April 2008

The impressive impact of cisplatin on cancer on one side and severe side effects, as well as the development of drug resistance during treatment on the other side, were the factors motivating scientists to design and synthesize new more potent analogues lacking disadvantages of cisplatin. Platinum(IV) complexes represent one of the perspective groups of platinum-based drugs. In this review, we summarize recent findings on both in vitro and in vivo effects of platinum(IV) complexes with adamantylamine. Based on a literary overview of the mechanisms of activity of platinum-based cytostatics, we discuss opportunities for modulating the effects of novel platinum complexes through interactions with apoptotic signaling pathways and with cellular lipids, including modulations of the mitochondrial cell death pathway, oxidative stress, signaling of death ligands, lipid metabolism/signaling, or intercellular communication. These approaches might significantly enhance the efficacy of both novel and established platinum-based cytostatics.
Improved Methodology for Monitoring Poly(amidoamine) Dendrimers Surface Transformations and Product Quality by Ultra Performance Liquid Chromatography
Authors: Cason Chevelle A. , Oehrle Stuart A. , Fabré Thomas A. , Girten Craig D. , Walters Keith A. , Tomalia Donald A. , Haik Kristi L. , Bullen Heather A.
Published: April 2008

Ultra performance liquid chromatography (UPLC) analysis was utilized for the first time as a methodology for monitoring poly(amidoamine) (PAMAM) dendrimer surface transformations and product quality. Results were compared to high‐performance liquid chromatography (HPLC) and were found to provide a vastly improved analytical method for the characterization of dendrimer polydispersity and variance in a typical surface modification. The application of UPLC increased the average number of theoretical plates by a factor of 7 and reduced retention times of analytes by 36%, while improving the resolution capability to discriminate surface variances in dendrimers. The new UPLC procedures were used to monitor surface modification of [core: ethylenediamine]; (G = 4); dendri‐poly(amidoamine)‐ (i.e., [EDA]; (G4); dendri‐PAMAM‐) to produce biotinylated dendrimer conjugates. The enhanced sensitivity and efficiency of the UPLC analyses allowed resolution of biotin substituent levels and a better characterization of the targeted dendrimer conjugates compared to traditional HPLC methodology.
Still in Womb: Intrauterine Acoustic Embedded Active Noise Control for Infant Incubators
Authors: Liu Lichuan , Gujjula Shruthi , Thanigai Priya , Kuo Sen M.
Published: April 2008

Excessive noise in neonatal care units and inside incubators can have a number of detrimental effects on an infant′s health. We proposed a novel, audio‐integrated approach to \tccheck{achieve} active noise control (ANC) for infant incubators. We also presented the implementation of the robust, nonlinear filtered‐X least mean M‐estimate algorithm, for reducing impulsive interference in incubators. The healthcare application is further enhanced by integrating the “womb effect”, that is, by using intrauterine and maternal heart sounds, proven to be beneficial to infant health, for soothing the infant and masking the residual noise. A computer model for audio‐integrated noise cancellation utilizing experimentally measured transfer functions is developed for simulations using real medical equipment noise. The simulation of the audio integrated ANC system produced optimal results and the system was further validated by real‐time experiments to be robust and efficient.
Surface Passivation and Photoluminescence of Mn-Doped ZnS Nanocrystals
Authors: Yang Ping , Bredol Michael
Published: April 2008

Enhanced photoluminescence (PL) is reported from Mn-doped ZnS nanocrystals (NCs) capped with ZnS (ZnS:Mn/ZnS core-shell NCs) and thioglycolic acid (TGA) (ZnS:Mn/ZnS core-shell NCs dispersed in an alkaline TGA solution). The NCs were prepared using a reverse micelle route. Comparing with initial ZnS:Mn core NCs, the ZnS:Mn/ZnS core-shell NCs exhibit much stronger orange PL (~580 nm). This is presumably the result of effective passivation of quenching ZnS:Mn NCs surface states by a pure ZnS shell. As for TGA-capped ZnS:Mn/ZnS core-shell NCs, the parallel decrease of a defect-related emission of ZnS is associated with the formation of a shell surface layer of TGA-Zn complexes. In summary, the combination of ZnS shells with TGA ligands was demonstrated to yield ZnS:Mn NCs with narrow size distribution and intense PL.
Benefits of Using Decorrelated Color Information for Face Segmentation/Tracking
Authors: Ionita Mircea C. , Corcoran Peter
Published: April 2008

We analyze in this paper the benefits that can be
derived from employing color image alignment techniques in the
context of face segmentation or tracking based on texture (defined
as the patch of intensities) template matching. By making full
use of the decorrelated color information, improvements on the
accuracy of the segmentation are demonstrated. This is intended
to enhance the face segmentation algorithm by increasing its
robustness to differences in images caused by various image
acquisition devices or settings or by variations in the ambient
illumination conditions.
Synthesis of Ag or Pt Nanoparticles by Hydrolysis of EitherAg2Naor PtNa
Authors: Wang Huabin , Northwood Derek O.
Published: April 2008

Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of eitherAg2Naor PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst forH2Oformation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.
Crystal Structure and Antitumor Activity of the Novel Zwitterionic Complex of tri‐n‐Butyltin(IV) with 2‐Thiobarbituric Acid
Authors: Balas Vasilios I. , Hadjikakou Sotiris K. , Hadjiliadis Nick , Kourkoumelis Nikolaos , Light Mark E. , Hursthouse Mike , Metsios Apostolos K. , Karkabounas Spyros
Published: April 2008

A novel tri‐n‐butyl(IV) derivative of 2‐thiobarbituric acid (HTBA) of formula [(n‐Bu) 3Sn(TBA) · H2O] (1) has been synthesized and characterized by elemental analysis and 119Sn‐NMR
and FT‐IR spectroscopic techniques. The crystal structure of
complex 1
has been determined by single crystal X‐ray diffraction analysis
at 120(2) K. The geometry around Sn(IV) is trigonal
bipyramidal. Three n‐butyl
groups and one oxygen atom from a deprotonated 2‐thiobarbituric
ligand are bonded to the metal center. The geometry is completed
with one oxygen from a water molecule. Compound 1 exhibits potent, in
vitro, cytotoxicity against sarcoma cancer cells (mesenchymal
tissue) from the Wistar rat, polycyclic aromatic hydrocarbons
(PAH, benzo[a]pyrene) carcinogenesis. In addition, the inhibition
caused by 1, in the rate of
lipoxygenase (LOX) catalyzed oxidation
reaction of linoleic acid to hyperoxolinoleic acid, has been also
kinetically and theoretically studied. The results are compared to
that of cisplatin.
TiO2/SiO2 Composite Films Immobilized on Foam Nickel Substrate for the Photocatalytic Degradation of Gaseous Acetaldehyde
Authors: Hu Hai , Xiao Wenjun , Yuan Jian , Shi Jianwei , Shangguan Wenfeng
Published: April 2008

The photocatalyst anatase titanium dioxide (TiO2) films were immobilized via sol‐gel technique on foam nickel modified with SiO2 films as transition layer (indicated as TiO2/SiO2 films). The structural properties of TiO2/SiO2 composite films were characterized using TG‐DSC, XRD, FE‐SEM, and BET. The photocatalytic activities of immobilized TiO2/SiO2 films were tested through photocatalytic degradation reactions of gaseous acetaldehyde under ultraviolet (UV) light irradiation. The substrate modification with transition layer of SiO2 films improved the specific surface area (SSA) of substrate and the acetaldehyde adsorption on photocatalyst film enormously and resulted in great enhancement of photocatalytic activity and stability. The degradation ratio of gaseous acetaldehyde (concentration of 100 ppmv) on TiO2/SiO2 photocatalysts reached 100% after 100 minutes of irradiation. The photocatalytic activity of TiO2/SiO2 films reduced about 15% after 9 consecutive runs, which was more stable than that of TiO2 films, and was completely recovered after heating at 300°C for 1 hour.
The Leishmania HSP20 Is Antigenic during Natural Infections, but, as DNA Vaccine, It does not Protect BALB/c Mice against Experimental L. amazonensis Infection
Authors: Montalvo-Álvarez Ana M. , Folgueira Cristina , Carrión Javier , Monzote-Fidalgo Lianet , Cañavate Carmen , Requena Jose M.
Published: April 2008

Protozoa of the genus Leishmania are causative agents
of leishmaniasis, an important health problem in both human and veterinary medicine. Here,
we describe a new heat shock protein (HSP) in Leishmania, belonging to
the small HSP (sHSP) family in kinetoplastids. The protein is highly conserved in
different Leishmania species, showing instead significant divergence
with sHSP′s from other organisms. The humoral response elicited against this protein
during Leishmania infection has been investigated in natural infected
humans and dogs, and in experimentally infected hamsters. Leishmania
HSP20 is a prominent antigen for canine hosts; on the contrary, the protein seems to
be a poor antigen for human immune system. Time‐course analysis of appearance of
anti‐HSP20 antibodies in golden hamsters indicated that these antibodies are produced
at late stages of the infection, when clinical symptoms of disease are patent. Finally, the
protective efficacy of HSP20 was assessed in mice using a DNA vaccine approach prior to
challenge with Leishmania amazonensis.
Optical Connecting of Fibersby Laser Beams Propagating from the Fibers Edges
Authors: Mensov Sergey Nikolayevich , Polushtaytsev Yuri Victorovich
Published: April 2008

A possibility to connect nonprecise positioned fibers in photopolymerizable compositions is under discussion in this paper. The processes of optical synthesis of connective waveguiding structures forming in such mediums directly by the radiation leaving the edges of connecting fibers are investigated numerically and experimentally as well. It was shown that nonlinear interaction of the light beams allows to connect misaligned and transversally shifted fibers with high efficiency.
Chromium‐Induced Nanocrystallization of a‐Si Thin Films into the Wurtzite Structure
Authors: Kumar K. Uma Mahendra , Krishna M. Ghanashyam
Published: April 2008

Chromium metal‐induced nanocrystallization of amorphous silicon (a‐Si) thin films is reported. The nanocrystalline nature of these films is confirmed from X‐ray diffraction and Raman spectroscopy. Significantly, the deconvolution of Raman spectra reveals that the thin films were crystallized in a mixed phase of cubic diamond and wurzite structure as evidenced by the lines at 512 and 496 cm−1, respectively. The crystallite sizes were between 4 to 8 nm. Optical properties of the crystallized silicon, derived from spectral transmittance curves, revealed high transmission in the region above the band gap. Optical band gap varied between 1.3 to 2.0 eV depending on the nature of crystallinity of these films and remained unaltered with increase in Cr addition from 5 to 30%. This signifies that the electronic structure of the nanocrystalline Silicon films is not affected considerably inspite of the presence of metal silicides and the process of crystallization.
Using a Semiconductor‐to‐Metal Transition to Control Optical Transmission through Subwavelength Hole Arrays
Authors: Donev E. U. , Suh J. Y. , Lopez R. , Feldman L. C. , Haglund R. F.
Published: April 2008

We describe a simple configuration in which the extraordinary optical transmission effect through subwavelength hole arrays in noble‐metal films can be switched by the semiconductor‐to‐metal transition in an underlying thin film of vanadium dioxide. In these experiments, the transition is brought about by thermal heating of the bilayer film. The surprising reverse hysteretic behavior of the transmission through the subwavelength holes in the vanadium oxide suggest that this modulation is accomplished by a dielectric‐matching condition rather than plasmon coupling through the bilayer film. The results of this switching, including the wavelength dependence, are qualitatively reproduced by a transfer matrix model. The prospects for effecting a similar modulation on a much faster time scale by using ultrafast laser pulses to trigger the semiconductor‐to‐metal transition are also discussed.
Effect of Ammonium Nitrate on Nanoparticle Size Reduction
Authors: Pingali Kalyana C. , Deng Shuguang , Rockstraw David A.
Published: April 2008

Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray‐pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order‐of‐magnitude (from 200 to 20 nm) smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm.
The Subwavelength Optical Field Confinement in a Multilayered Microsphere with Quasiperiodic Spherical Stack
Authors: Burlak Gennadiy N. , Diaz-de-Anda A.
Published: April 2008

We study the frequency spectrum of nanoemitters
placed in a microsphere with a quasiperiodic subwavelength
spherical stack. The spectral evolution of transmittancy at the
change of thickness of two‐layer blocks, constructed following the
Fibonacci sequence, is investigated. When the number of layers
(Fibonacci order) increases, the structure of spectrum acquires a
fractal form. Our calculations show the radiation confinement and
gigantic field enhancement, when the ratio of layers’ widths in
twolayer blocks of the stack is close to the golden mean
value.
Gold and TiO2 Nanostructurated Surfaces for Assembling of Electrochemical Biosensors
Authors: Curulli Antonella , Zane Daniela
Published: April 2008

Devices based on nanomaterials are emerging as a powerful and general class of ultrasensitive sensors for the direct detection of biological and chemical species. In this work, we report the preparation and the full characterization of nanomaterials such as gold nanowires and TiO2 nanostructured films to be used for assembling of electrochemical biosensors. Gold nanowires were prepared by electroless deposition within the pores of polycarbonate particle track‐etched membranes (PTMs). Glucose oxidase was deposited onto the nanowires using self‐assembling monolayer as an anchor layer for the enzyme molecules. Finally, cyclic voltammetry was performed for different enzymes to test the applicability of gold nanowires as biosensors. Considering another interesting nanomaterial, the realization of functionalised TiO2 thin films on Si substrates for the immobilization of enzymes is reported. Glucose oxidase and horseradish peroxidase immobilized onto TiO2‐based nanostructured surfaces exhibited a pair of well‐defined and quasireversible voltammetric peaks. The electron exchange between the enzyme and the electrodes was greatly enhanced in the TiO2 nanostructured environment. The electrocatalytic activity of HRP and GOD embedded in TiO2 electrodes toward H2O2 and glucose, respectively, may have a potential perspective in the fabrication of third‐generation biosensors based on direct electrochemistry of enzymes.
On Minimal Realizations and Minimal Partial Realizations of Linear Time‐Invariant Systems Subject to Point Incommensurate Delays
Authors: De la Sen M.
Published: April 2008

This paper investigates key aspects of realization and partial realization theories for linear time‐invariant systems being subject to a set of incommensurate internal and external point delays. The results are obtained based on the use of formal Laurent expansions whose coefficients are polynomial matrices of appropriate orders and which are also appropriately related to truncated and infinite block Hankel matrices. The above‐mentioned polynomial matrices arise in a natural way from the transcendent equations associated with the delayed dynamics. The results are linked to the properties of controllability and observability of dynamic systems. Some related overview is given related to robustness concerned with keeping the realization properties under mismatching between a current transfer matrix and a nominal one.
PPAR‐α Ligands as Potential Therapeutic Agents for Wet Age‐Related Macular Degeneration
Authors: del V Cano Marisol , Gehlbach Peter L.
Published: April 2008

The peroxisome proliferator‐activated receptors (PPAR′s) are members of the steroid/thyroid nuclear receptor, superfamily of transcription factors. There are currently three known PPAR subtypes, α, β, and γ. The PPARs are now recognized participants in a number
of biological pathways some of which are implicated in the
pathogenesis of age‐related macular degeneration (AMD). These
include immune modulation, lipid regulation, and
oxidant/antioxidant pathways important to the onset and
progression of “dry” AMD, and vascular endothelial
growth factor (VEGF) mediated pathways that stimulate choroidal
neovascularization (CNV), characteristic of “wet” AMD.
PPAR‐α is found in retina and also on vascular cells
important to formation of CNV. At this time, however, relatively
little is known about potential contributions of PPAR‐α to the pathogenesis of dry and wet AMD. This review examines current literature for potential roles of PPAR‐α in the pathogenesis and potential treatment of AMD with emphasis on prevention and treatment of wet AMD.
Global Self‐similar Solutions of a Class of Nonlinear Schrödinger Equations
Authors: YE Yaojun
Published: April 2008

For a certain range of the value p in the nonlinear term |u|pu, in this paper we mainly
study the global existence and uniqueness of global self‐similar solutions to the Cauchy problem for
some nonlinear Schrödinger equations using the method of harmonic analysis.
The New Generation System of Japan Standard Time at NICT
Authors: Hanado Yuko , Imamura Kuniyasu , Kotake Noboru , Nakagawa Fumimaru , Shimizu Yoshiyuki , Tabuchi Ryo , Takahashi Yukio , Hosokawa Mizuhiko , Morikawa Takao
Published: April 2008

NICT has completed a set of major upgrades in its systems for the realization of Japan standard time. One of the most significant changes is the introduction of hydrogen masers as signal sources for UTC (NICT) instead of Cs atomic clocks. This greatly improves the short‐term stability of UTC (NICT). Another major change is the introduction of a newly developed 24‐channel dual‐mixer‐time‐difference system (DMTD) as the main tool for measurements. The reliability of the system is also improved by enhanced redundancy and monitoring systems. The new JST system has been in regular operation since February 2006.
A Discrete Particle Swarm Optimization Algorithm for Uncapacitated Facility Location Problem
Authors: Guner Ali R. , Sevkli Mehmet
Published: April 2008

A discrete version of particle swarm optimization (DPSO) is employed to solve uncapacitated facility location (UFL) problem which is one of the most widely studied in combinatorial optimization. In addition, a hybrid version with a local search is defined to get more efficient results. The results are compared with a continuous particle swarm optimization (CPSO) algorithm and two other metaheuristics studies, namely, genetic algorithm (GA) and evolutionary simulated annealing (ESA). To make a reasonable comparison, we applied to same benchmark suites that are collected fromOR‐library. In conclusion, the results showed thatDPSOalgorithm is slightly better thanCPSOalgorithm and competitive withGAandESA.
Hyperphosphorylated Cortactin in Cancer Cells Plays an Inhibitory Role in Cell Motility
Authors: Jia Lin , Uekita Takamasa , Sakai Ryuichi
Published: April 2008

Cortactin is frequently overexpressed in cancer cells, and changes of the levels of its tyrosine phosphorylation have been observed in several cancer cells. However, how the expression level and phosphorylation state of cortactin would influence the ultimate cellular function of cancer cells is unknown. In this study, we analyzed the role of cortactin in gastric and breast cancer cell lines using RNA interference technique and found that knockdown of cortactin inhibited cell migration in a subset of gastric cancer cells with a lower level of its tyrosine phosphorylation, whereas it greatly enhanced cell migration and increased tyrosine phosphorylation of p130Cas in other subsets of cells with hyperphosphorylated cortactin. Consistent results were obtained when hyperphosphorylation of cortactin was induced in MCF7 breast cancer cells by expressing Fyn tyrosine kinase. Additionally, immunostaining analysis showed that knockdown of hyperphosphorylated cortactin resulted in the recruitment of p130Cas to focal adhesions. These results suggest that cortactin hyperphosphorylation suppresses cell migration possibly through the inhibition of membrane localization and tyrosine phosphorylation of p130Cas. (Mol Cancer Res 2008;6(4):654–62)
Vascular Endothelial Growth Factor Stimulates Organ-Specific Host Matrix Metalloproteinase-9 Expression and Ovarian Cancer Invasion
Authors: Belotti Dorina , Calcagno Catia , Garofalo Angela , Caronia Daniela , Riccardi Elena , Giavazzi Raffaella , Taraboletti Giulia
Published: April 2008

Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP) regulate each other, contributing to tumor progression. We have previously reported that MMP9 induces the release of tumor VEGF, promoting ascites formation in human ovarian carcinoma xenografts. The aim of this study was to investigate whether tumor-derived VEGF regulated the expression of gelatinase by the stroma, influencing the invasive properties of ovarian tumors. Tumor variants derived from 1A9 human ovarian carcinoma, stably expressing VEGF121 in the sense (1A9-VS-1) and antisense orientations (1A9-VAS-3), were used. In vivo, zymographic analysis of tumors from 1A9-VS-1 implanted in the peritoneal cavity of nude mice showed higher levels of gelatinases, particularly murine MMP9, indicating that VEGF stimulates host expression of the matrix-degrading enzyme. Murine MMP9 expression was also high in the ovaries of mice bearing 1A9-VS-1 tumors. The effect on host MMP9 activity was organ-specific. The levels of host pro-MMP9 in ovaries correlated with the plasma levels of tumor VEGF and with the selective invasion of the ovaries. Induction of host MMP9 expression in tumors and ovaries was independent of the site of tumor growth as it was seen in mice carrying both intraperitoneal and subcutaneous tumors. The anti-VEGF antibody bevacizumab (Avastin) inhibited MMP9 expression and tumor invasion in the ovaries of mice bearing 1A9-VS-1 tumors. These findings point to a complex cross-talk between VEGF and MMPs in the progression of ovarian tumor and suggest the possibility of using VEGF inhibitors to affect MMP-dependent tumor invasion. (Mol Cancer Res 2008;6(4):525–34)
DNA Damage Responses: Mechanisms and Roles in Human Disease
Authors: Kastan Michael B.
Published: April 2008

Significant progress has been made in recent years in elucidating the molecular controls of cellular responses to DNA damage in mammalian cells. Much of our understanding of the mechanisms involved in cellular DNA damage response pathways has come from studies of human cancer susceptibility syndromes that are altered in DNA damage responses. Ataxia-telangiectasia mutated (ATM), the gene mutated in the disorder ataxia-telangiectasia, codes for a protein kinase that is a central mediator of responses to DNA double-strand breaks (DSB) in cells. Once activated, ATM phosphorylates numerous substrates in the cell that modulate the response of the cell to the DNA damage. We recently developed a novel system to create DNA DSBs at defined endogenous sites in the human genome and used this system to detect protein recruitment and loss at and around these breaks by chromatin immunoprecipitation. Results from this system showed the functional importance of ATM kinase activity and phosphorylation in the response to DSBs and supported a model in which ordered chromatin structure changes that occur after DNA breakage and that depend on functional NBS1 and ATM facilitate DNA DSB repair. Insights about these pathways provide us with opportunities to develop new approaches to benefit patients. Examples and opportunities for developing inhibitors that act as sensitizers to chemotherapy or radiation therapy or activators that could improve responses to cellular stresses, such as oxidative damage, are discussed. Relevant to the latter, we have shown benefits of an ATM activator in disease settings ranging from metabolic syndrome to cancer prevention. (Mol Cancer Res 2008;6(4):517–24)
Hyperbaric Oxygen Treatment Restores Sudden Hearing Loss in a Patient with Fabry Disease
Authors: Frantz Markus C. , Pontz Bertram F. , Arnold Wolfgang
Published: April 2008

Fabry disease is an X-linked inherited disorder of glycosphingolipid metabolism due to the deficient activity of a lysosomal enzyme, α-galactosidase A. The resultant systemic accumulation of sphingolipids can lead to progressive and sudden hearing loss alongside renal, cardiac and cerebrovascular complications. Although replacement therapy seems to be beneficial for cochlear function, few data are available regarding treatment of sudden hearing loss. This case report describes the course of a unilateral sudden hearing loss in a young (15-year-old) male patient and its improvement following hyperbaric oxygen treatment.
Morphological Analysis of the Interstitial Ultrasonic Ablation in Porcine Liver in vivo
Authors: Seket B. , Lafon C. , Salomir R. , Chapelon J.Y. , Paquet C. , Scoazec J.Y. , Cathignol D.
Published: April 2008

Background: The shape of the induced thermal ablation area is as important as its dimension. The aim of this study was to analyze the size reproducibility and the aspect of the interstitial ultrasonic ablation obtained by a planar transducer in porcine liver in vivo. Methods: Five pigs were used. Two complete ultrasonic lesions were made in each animal under pedicle clamping. All the lesions underwent MR examination on day 7 and then a histological analysis. Results: The tested probe has the advantage of providing a step-by-step and highly directional treatment in the target zone. The ultrasonic lesions presented as well-defined and homogenous areas of tissue coagulation. The lesion volumes ranged from 8.1 to 92.3 cm3 with an averaged lesion length of 56 mm at gross examination. Three-dimensional reconstruction of the lesions from the MR images showed cylindrical and conical shapes. Large intrahepatic vessels distorted the lesion shape, and the vicinity of the application to the liver surface increased significantly the volume of the ultrasonic necrosis. Histological examination showed complete necrosis in the area of damage. Conclusion: The ultrasonic ablation has a regular shape, always with sharply defined borders. However, it showed some variability in the size of the induced lesions.
Britain, the Transatlantic Alliance, and the Arab-Israeli War of 1973
Authors: Hughes Geraint
Published: April 2008

This article analyzes the impact on transatlantic relations of the October 1973 Arab-Israeli war, focusing on the discrepancy between U.S. and British views of Middle Eastern security before and during the conflict. Despite the institutional factors shaping the U.S.-British “special relationship” and the much greater power of the United States compared to Britain, British policy during the 1973 war was sharply at odds with U.S. policy. This article shows that British policy toward the Middle East was shaped not only by economic concerns (namely the importance of Arab oil to the UK economy) but also by the strategic requirement to undermine Soviet influence in the region and strengthen ties between the Western powers and the Arab states.
TD-Gammon, a Self-Teaching Backgammon Program, Achieves Master-Level Play
Authors: Tesauro Gerald
Published: April 2008

TD-Gammon is a neural network that is able to teach itself to play backgammon solely by playing against itself and learning from the results, based on the TD(λ) reinforcement learning algorithm (Sutton 1988). Despite starting from random initial weights (and hence random initial strategy), TD-Gammon achieves a surprisingly strong level of play. With zero knowledge built in at the start of learning (i.e., given only a “raw” description of the board state), the network learns to play at a strong intermediate level. Furthermore, when a set of hand-crafted features is added to the network's input representation, the result is a truly staggering level of performance: the latest version of TD-Gammon is now estimated to play at a strong master level that is extremely close to the world's best human players.