bluuebunny/crossref_metadata_2025 huggingface dataset:
Amitriptyline: sex‐dependent effect on sympathetic response and anxiety in rats submitted to early maternal separation and variable chronic stress in adulthood
Authors: Díaz Luján V.E. , Castellanos M.M. , Levin G. , Suárez M.M.
Published: March 2008

The aim of the present study was to determine the effects of chronic treatment with the antidepressant amitriptyline on sympathetic nervous system activity and anxiety in male and female rats submitted to maternal separation (MS) and variable chronic stress (VCS). We observed that the treatment with amitriptyline produced a significant increase in norepinephrine (NE) plasma levels in non‐maternally separated (NMS), non‐stressed (NVCS) males in relation to vehicle‐treated males, whereas in females the antidepressant produced a significant decrease in epinephrine (E) and NE when compared to the vehicle‐treated group. In NMS/VCS males, amitriptyline produced a significant increase in the time spent on the open arms (TIME) in relation to the vehicle‐treated group. In NMS/VCS females, amitriptyline produced a significant increase in TIME when compared to males. MS/VCS females showed a significant increase in the number of entries into the open arms (ENTRIES) in relation to males with the same treatment. This result suggests that there is a dimorphic response in coping with physical or emotional stressful situations and that amitriptyline acts in a differential way, being more effective in females.
Chronic developmental exposure to phenytoin has long‐term behavioral consequences
Authors: Mowery Todd M. , McDowell Angela L. , Garraghty Preston E.
Published: March 2008

Anti‐epileptic compounds have been linked to several developmental disorders. Specifically, fetal exposure to phenytoin is linked to fetal hydantoin syndrome in humans. We have developed a rat model of fetal hydantoin syndrome in an effort to explore the relationship between drug exposure, development, and learning and memory. Previous studies of this animal model have used various embryological periods of exposure; however, the human syndrome is reported in the offspring of mothers that maintain drug regimens throughout gestation and nursing. To that end, the present study investigated associative learning in rats exposed to therapeutic levels of phenytoin throughout prenatal development and the postnatal pre‐weaning period. We used an instrumental appetitive‐to‐aversive transfer paradigm, which has hippocampal‐dependent components, and an avoidance‐conditioning paradigm to test simple associative learning and higher‐order learning and memory. Compared to controls, we report increased rates of acquisition and performance by the phenytoin group in both the appetitive and the avoidance learning paradigm, and a substantial impairment in avoidance learning following the transfer from appetitive to aversive conditioning. The positive deficit observed with simple associative learning and the negative transfer effect associated with higher order learning suggests that chronic exposure to phenytoin throughout gestation disrupts hippocampal development, which subsequently leads to impaired function in adulthood.
Current crustal deformation in the northern Tien Shan: GPS and seismological data
Authors: Tychkov S.A. , Kuchai O.A. , Bushenkova N.A. , Bragin V.D. , Kalmetieva Z.A.
Published: March 2008

We study crustal deformation in the northern Tien Shan as recorded in strain rates derived from earthquake and GPS data. Geodetic strain rates indicate general shortening along the N-S component and agree with Quaternary fault slip rates and with the strain field obtained from earthquake mechanisms, all being signature of overall north-south contraction in the region.

The GPS strain field changes quickly in time, especially in the W-E direction, and is produced by a joint effect of elastic, plastic, and quasi-plastic deformation. The seismological strain field reflects the effect of external tectonic forces applied to seismogenic crust and the stress change due to crustal heterogeneity and geometry of the study area. Seismological and GPS strain rates carry information of different kinds. The former reflect formation of local structures mainly in the brittle crust, such as a local pull-apart in the center of the Lake Issyk Kul area, whereas the latter provide clues to mechanisms that drive the geological evolution of the mountain terrain as a whole. The current evolution may involve the effect of density instability at the lithosphere-asthenosphere boundary.
The genetic relationship of the deformed peridotites and garnet megacrysts from kimberlites with asthenospheric melts
Authors: Solov’eva L.V. , Lavrent’ev Yu.G. , Egorov K.N. , Kostrovitskii S.I. , Korolyuk V.N. , Suvorova L.F.
Published: March 2008

New data on geochemistry of incompatible trace elements (Nb, Zr, Hf, Ti, Y, REE) in garnets (Ga) and clinopyroxenes (Cpx) from deformed high-temperature garnet lherzolites, harzburgites, and garnet megacrysts from the Udachnaya pipe are presented. According to textures and petrographic composition, the deformed Ga-bearing peridotites are subdivided into coarse- and fine-porphyroclastic. Rocks of the first type (Ga-lherzolites) are enriched in Ga and Cpx (up to 30% each); among them, there are xenoliths with deformed Ga, Cpx, and Ol megacrysts. Deformed fine-porphyroclastic peridotites (Ga-lherzolites and Ga-harzburgites) are depleted in Ga (≤10%) and Cpx (≤3–5%). Four Ga megacrysts are typical of a Cr-poor association (0.33–1.63% Cr2O3; 0.56–1.05% TiO2; Mg# = 0.67–0.86). Garnets from deformed high-temperature coarse-porphyroclastic Ga-lherzolites are similar in geochemistry to Ga megacrysts: Their chondrite-normalized REE curves rise smoothly from La to Yb, and their spidergrams show peaks of Nb, Zr + Hf, and Ti. The narrow marginal zones of Ga grains from Ga-lherzolites are enriched in LREE. The peaks of HFSE in the Ga curves are smoothed out. The element patterns of garnet from fine-porphyroclastic Ga-lherzolites and Ga-harzburgites show a sinusoidal distribution of REE and Zr + Hf and Ti minima on the spidergrams. The element patterns of Cpx from both types of rocks are nearly the same: The curves are convex in the field of LREE, drastically drop from Nd to Yb, and have minima of Nb, Zr + Hf, and Ti. The curves of melts (L) equilibrated with Ga (calculated from partition coefficients) show a drastic enrichment in LREE and peaks of Nb, Zr + Hf, and Ti for garnet from deformed coarse-porphyroclastic lherzolites and megacrysts. The L curves of fine-porphyroclastic lherzolites and harzburgites have distinct minima of Zr + Hf and more sharply slope from Nd to Yb. The L curves of Cpx have minima of Nb, Zr + Hf, and Ti and lie near the field of basaltoid kimberlites from the Udachnaya pipe. All these data are consistent with the model of percolative fractional crystallization. The matter of mantle plume arrived from the mantle transition zone might have been the source of asthenospheric liquids inducing specific magmatic metasomatism at the continental lithosphere–asthenosphere boundary. The source material was enriched in majorite and silicate-perovskite or in ancient oceanic crustal matter.
HIV-1/parasite co-infection and the emergence of new parasite strains
Authors: LLOYD-SMITH JAMES O. , POSS MARY , GRENFELL BRYAN T.
Published: March 2008

HIV-1 and parasitic infections co-circulate in many populations, and in a few well-studied examples HIV-1 co-infection is known to amplify parasite transmission. There are indications that HIV-1 interacts significantly with many other parasitic infections within individual hosts, but the population-level impacts of co-infection are not well-characterized. Here we consider how alteration of host immune status due to HIV-1 infection may influence the emergence of novel parasite strains. We review clinical and epidemiological evidence from five parasitic diseases (malaria, leishmaniasis, schistosomiasis, trypanosomiasis and strongyloidiasis) with emphasis on how HIV-1 co-infection alters individual susceptibility and infectiousness for the parasites. We then introduce a simple modelling framework that allows us to project how these individual-level properties might influence population-level dynamics. We find that HIV-1 can facilitate invasion by parasite strains in many circumstances and we identify threshold values of HIV-1 prevalence that allow otherwise unsustainable parasite strains to invade successfully. Definitive evidence to test these predicted effects is largely lacking, and we conclude by discussing challenges in interpreting available data and priorities for future studies.
Measuring immune system variation to help understand host-pathogen community dynamics
Authors: BRADLEY J. E. , JACKSON J. A.
Published: March 2008

Carefully chosen immunological measurements, informed by recent advances in our understanding of the diversity and control of immune mechanisms, can add great interpretative value to ecological studies of infection. This is especially so for co-infection studies, where interactions between species are often mediated via the host's immune response. Here we consider how immunological measurements can strengthen inference in different types of co-infection analysis. In particular, we identify how measuring immune response variables in field studies can help reveal inter-species interactions otherwise obscured by confounding processes operating on count or prevalence data. Furthermore, we suggest that, due to the difficulty of quantifying microbial pathogen communities in field studies, innate responses against broad pathogen types (mediated by pattern response receptors) may be useful quantitative markers of exposure to bacteria and viruses. An ultimate goal of ecological co-infection studies may also be to understand how dynamics within host-parasite assemblages emerge from trade-offs involving different arms of the immune system. We reflect on the phenotypic measures that might best represent levels of responsiveness and bias in immune function. These include mediators associated with different T-helper cell subsets and innate responses controlled by pattern response receptors, such as the Toll-like receptors (TLRs).
Infection with acanthocephalans increases the vulnerability ofGammarus pulex(Crustacea, Amphipoda) to non-host invertebrate predators
Authors: KALDONSKI N. , PERROT-MINNOT M.-J. , MOTREUIL S. , CÉZILLY F.
Published: March 2008

Phenotypic alterations induced by parasites in their intermediate hosts often result in enhanced trophic transmission to appropriate final hosts. However, such alterations may also increase the vulnerability of intermediate hosts to predation by non-host species. We studied the influence of both infection with 3 different acanthocephalan parasites (Pomphorhynchus laevis,P. tereticollis, andPolymorphus minutus) and the availability of refuges on the susceptibility of the amphipodGammarus pulexto predation by 2 non-host predators in microcosms. Only infection withP. laevisincreased the vulnerability of amphipods to predation by crayfish,Orconectes limosus. In contrast, in the absence of refuges, the selectivity of water scorpions,Nepa cinerea, for infected prey was significant and did not differ according to parasite species. When a refuge was available for infected prey, however, water scorpion selectivity for infected prey differed between parasite species. BothP. tereticollis- andP. laevis-infected gammarids were more vulnerable than uninfected ones, whereas the reverse was true ofP. minutus-infected gammarids. These results suggest that the true consequences of phenotypic changes associated with parasitic infection in terms of increased trophic transmission of parasites deserve further assessment.
Incomplete stimulus representations and the loss of cognitive access in cerebral achromatopsia
Authors: Kentridge Robert William
Published: March 2008

When processing of stimuli occurs without attention, phenomenal experience, as well as cognitive access, may be lost. Sensory representations are, however, constructed by neural machinery extending far beyond sensory receptors. In conditions such as cerebral achromatopsia incomplete sensory representations may still elicit phenomenal experience but these representations might be too aberrant to be integrated into the wider cognitive workspace.
Phenomenology without conscious access is a form of consciousness without top-down attention
Authors: Koch Christof , Tsuchiya Naotsugu
Published: March 2008

We agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.
Partial awareness and the illusion of phenomenal consciousness
Authors: Kouider Sid , de Gardelle Vincent , Dupoux Emmanuel
Published: March 2008

The dissociation Block provides between phenomenal and access consciousness (P-consciousness and A-consciousness) captures much of our intuition about conscious experience. However, it raises a major methodological puzzle, and is not uniquely supported by the empirical evidence. We provide an alternative interpretation based on the notion of levels of representation and partial awareness.
Two kinds of access
Authors: Levine Joseph
Published: March 2008

I explore the implications of recognizing two forms of access that might be constitutively related to phenomenal consciousness. I argue, in support of Block, that we don't have good reason to think that the link to reporting mechanisms is the kind of access that distinguishes an experience from a mere state.
Dodging the explanatory gap – or bridging it
Authors: McDermott Drew
Published: March 2008

Assuming our understanding of the brain continues to advance, we will at some point have a computational theory of how access consciousness works. Block's supposed additional kind of consciousness will not appear in this theory, and continued belief in it will be difficult to sustain. Appeals to “what it's like” to experience such-and-such will carry little weight when we cannot locate a subject for whom it might be like something.
Reportability and illusions of phenomenality in the light of the global neuronal workspace model
Authors: Naccache Lionel , Dehaene Stanislas
Published: March 2008

Can we ever experimentally disentangle phenomenal consciousness from the cognitive accessibility inherent to conscious reports? In this commentary, we suggest that (1) Block's notion of phenomenal consciousness remains intractably entangled with the need to obtain subjective reports about it; and (2) many experimental paradigms suggest that the intuitive notion of a rich but non-reportable phenomenal world is, to a large extent illusory – in a sense that requires clarification.
Phenomenal consciousness lite: No thanks!
Authors: O'Regan J. Kevin , Myin Erik
Published: March 2008

The target article appeals to recent empirical data to support the idea that there is more to phenomenality than is available to access consciousness. However, this claim is based on an unwarranted assumption, namely, that some kind of cortical processing must be phenomenal. The article also considerably weakens Block's original distinction between a truly nonfunctional phenomenal consciousness and a functional access consciousness. The new form of phenomenal consciousness seems to be a poor-man's cognitive access.
Phenomenological overflow and cognitive access
Authors: Rosenthal David M.
Published: March 2008

I argue that the partial-report results Block cites do not establish that phenomenology overflows cognitive accessibility, as Block maintains. So, without additional argument, the mesh he sees between psychology and neuroscience is unsupported. I argue further that there is reason to hold, contra Block, that phenomenology does always involve some cognitive access to the relevant experience.
Modelling of a special class of spherical parallel manipulators with Euler parameters
Authors: Bai Shaoping , Hansen Michael R. , Andersen Torben O.
Published: March 2008

A method of workspace modelling for spherical parallel manipulators (SPMs) of symmetrical architecture is developed by virtue of Euler parameters in the paper. The adoption of Euler parameters in the expression of spatial rotations of SPMs helps not only to eliminate the possible singularity in the rotation matrix, but also to formulate all equations in polynomials, which are more easily manipulated. Moreover, a homogeneous workspace can be obtained with Euler parameters for the SPMs, which facilitates the evaluation of dexterity. In this work, the problem of workspace modelling and analysis is formulated in terms of Euler parameters. An equation dealing with boundary surfaces is derived and branches of boundary surface are identified. Evaluation of dexterity is explored to quantitatively describe the capability of a manipulator to attain orientations. The singularity identification is also addressed. Examples are included to demonstrate the application of the proposed method.
Weak*- continuous homomorphisms of Fourier–Stieltjes algebras
Authors: ILIE MONICA , STOKKE ROSS
Published: March 2008

For a locally compact group G, let B(G) denote its Fourier–Stieltjes algebra. Any continuous, piecewise affine map α: Y ⊂ H → G induces a completely bounded algebra homomorphism jα: B(G) → B(H) [14, 15] and we prove that jα is w* – w* continuous if and only if α is an open map. This extends one of the main results in [3], due to M.B. Bekka, E. Kaniuth, A.T. Lau and G. Schlichting. Several classical theorems regarding isomorphisms and extensions of homomorphisms on group algebras of abelian groups are extended to the setting of Fourier–Stieltjes algebras of amenable groups. As applications, when G is amenable we provide complete characterizations of those maps between Fourier–Stieltjes algebras that are either associated to a piecewise affine mapping, or are completely bounded and w* – w* continuous.
Stromboli 2007 eruption: Deflation modeling to infer shallow‐intermediate plumbing system
Authors: Bonaccorso A. , Gambino S. , Guglielmino F. , Mattia M. , Puglisi G. , Boschi E.
Published: March 2008

During the effusive phase of the Stromboli 2007 eruption, the GPS and tilt stations recorded small but significant changes which, for the first time at this volcano, clearly indicated a deflation. We modeled the deflation, inferring a depressurizing vertically elongated source with centre under the volcano edifice about 2.8 km below sea level. The model, whose position is above the magma source region inferred by petrological studies, and the associated rapid deflation suggest a near free pathway for magma ascent from this source to the upper shallow conduit.
Typical auroral substorm: A bifurcated oval
Authors: Gjerloev J. W. , Hoffman R. A. , Sigwarth J. B. , Frank L. A. , Baker J. B. H.
Published: March 2008

Utilizing global auroral images obtained by Polar Visible Imaging System Earth Camera, we have analyzed the UV emissions from 116 auroral substorms. The events selected were fairly isolated and had to expand from a localized onset. It was found that essentially all auroral events fulfilling these simple criteria expand into the Akasofu (1964) bulge‐type aurora. Averaged auroral emission patterns were compiled for 11 time steps of the substorm covering 20 min prior to the onset until well into the recovery phase. This compilation required a three‐step normalization technique, one temporal based on the expansion time and two spatial, magnetic local time and latitude. These average patterns were then fit to either a single or double Gaussian distribution in latitude for each of 24 magnetic local times. On the basis of this analysis we made the following conclusions. The normalization technique is highly efficient in maintaining the key features in the individual auroral emission patterns, even though the individual events varied significantly in intensity, size, position, and lifetime. Thus our normalization results quantitatively validate the Akasofu (1964) assumption that key auroral features exist in the bulge‐type auroral substorm. After the substorm onset the auroral oval becomes clearly bifurcated consisting of two components: the oval aurora in the latitude range of the preonset oval and expanding primarily eastward postmidnight, and the bulge aurora, which emerges out of the oval, expanding poleward and both east and west in MLT. The oval aurora decay faster than the bulge emissions indicating that the decays have separate time constants. Owing to the pronounced difference in the spatiotemporal behavior of the two auroral components we suggest that their sources are quasi‐independent.
Superdiffusive transport of electrons accelerated at corotating interaction regions
Authors: Perri Silvia , Zimbardo Gaetano
Published: March 2008

Energetic particles in the solar wind are accelerated at interplanetary shock waves associated with corotating interaction regions (CIRs) and propagate in the presence of a spectrum of magnetic turbulence, which causes pitch angle scattering upstream of the shock. Besides normal diffusive transport, we study the possibility of superdiffusive transport characterized by Levy random walks. We consider the relevant propagator, which is a power law with slope 2 < μ < 3, instead of being a Gaussian, as for standard diffusion. We show that in the case of superdiffusive transport, the time profile of particles accelerated at a travelling planar shock is a power law with slope γ = μ−2, rather than an exponential decay as expected in the case of normal diffusion. We consider a data set of interplanetary shocks in the solar wind, the CIR‐associated forward and reverse shocks detected by Ulysses between January 1992 and May 1993. We find that the time profiles of energetic electrons, with energies between 42 and 290 keV, correspond to power laws, with slopes γ≃ 0.60–0.98, implying superdiffusive transport. These results show that the propagation of energetic electrons in the turbulent environment of the solar wind is intermediate between ballistic (or scatter‐free) and diffusive, in agreement with the results of recent numerical simulations. Our results promise to have application in models of shock particle acceleration and represent a new tool for the interpretation of the observed particle profiles throughout the heliosphere.
Numerical studies on three‐dimensional earthward fast plasma flows in the near‐Earth plasma sheet by the spontaneous fast reconnection model
Authors: Kondoh K. , Ugai M.
Published: March 2008

The spontaneous fast reconnection model is applied to the earthward fast flow events observed in the near‐Earth plasma sheet. Here, the earthward fast flow events include both of bursty bulk flow events and flow burst events. In order to apply it directly to actual observations, virtual probes are located in the plasma sheet region in the three‐dimensional simulation domain so that we can directly observe the temporal variations of plasma quantities in accordance with the growth and proceeding of the fast reconnection. In this model, magnetic reconnection drastically evolves and Alfvénic fast plasma jet flows in the very restricted narrow channel, and a large‐scale plasmoid is formed ahead of the fast plasma jet. The results of virtual observation of these evolutions are found to be in good agreement with actual satellite observations. At the same time, in the lobe region, travelling compression regions (TCRs) are observed in connection with the fast flow events. The temporal profiles of magnetic fields detected by the virtual probes are also in good agreement with actual satellite observations. It is concluded that the earthward fast flow events and earthward TCR events result from the fast reconnection mechanism.
Paleogene biomarker records from the central Arctic Ocean (Integrated Ocean Drilling Program Expedition 302): Organic carbon sources, anoxia, and sea surface temperature
Authors: Weller Petra , Stein Ruediger
Published: March 2008

During Integrated Ocean Drilling Program Expedition 302 (Arctic Coring Expedition (ACEX)) a more than 200 m thick sequence of Paleogene organic carbon (OC)‐rich (black shale type) sediments was drilled. Here we present new biomarker data determined in ACEX sediment samples to decipher processes controlling OC accumulation and their paleoenvironmental significance during periods of Paleogene global warmth and proposed increased freshwater discharge in the early Cenozoic. Specific source‐related biomarkers includingn‐alkanes, fatty acids, isoprenoids, carotenoids, hopanes/hopenes, hopanoic acids, aromatic terpenoids, and long‐chain alkenones show a high variability of components, derived from marine and terrestrial origin. The distribution of hopanoic acid isomers is dominated by compounds with the biological 17β(H), 21β(H) configuration indicating a low level of maturity. On the basis of the biomarker data the terrestrial OC supply was significantly enriched during the late Paleocene and part of the earliest Eocene, whereas increased aquatic contributions and euxinic conditions of variable intensity were determined for the Paleocene‐Eocene thermal maximum and Eocene thermal maximum 2 events as well as the middle Eocene time interval. Furthermore, samples from the middle Eocene are characterized by the occurrence of long‐chain alkenones, high proportions of lycopane, and high ratios (>0.6) of (n‐C35+ lycopane)/n‐C31. The occurrence of C37‐alkenenones, which were first determined toward the end of theAzollafreshwater event, indicates that the OC becomes more marine in origin during the middle Eocene. Preliminary U37K′‐based sea surface temperature (SST) values display a long‐term temperature decrease of about 15°C during the time interval 49–44.5 Ma (25° to 10°C), coinciding with the global benthicδ18O cooling trend after the early Eocene climatic optimum. At about 46 Ma, parallel with onset of ice‐rafted debris, SST (interpreted as summer temperatures) decreased to values <15°C. For the late early Miocene a SST of 11°–15°C was determined. Most of the middle Eocene ACEX sediments are characterized by a smooth short‐chainn‐alkane distribution, which may point to natural oil‐type hydrocarbons from leakage of petroleum reservoirs or erosion of related source rocks and redeposition.
Widespread distribution of proteorhodopsins in freshwater and brackish ecosystems
Authors: Atamna-Ismaeel Nof , Sabehi Gazalah , Sharon Itai , Witzel Karl-Paul , Labrenz Matthias , Jürgens Klaus , Barkay Tamar , Stomp Maayke , Huisman Jef , Beja Oded
Published: March 2008

Proteorhodopsins (PRs) are light-driven proton pumps that have been found in a variety of marine environments. The goal of this study was to search for PR presence in different freshwater and brackish environments and to explore the diversity of non-marine PR protein. Here, we show that PRs exist in distinctly different aquatic environments, ranging from clear water lakes to peat lakes and in the Baltic Sea. Some of the PRs observed in this study formed unique clades that were not previously observed in marine environments, whereas others were similar to PRs found in non-marine samples of the Global Ocean Sampling (GOS) expedition. Furthermore, the similarity of several PRs isolated from lakes in different parts of the world suggests that these genes are dispersed globally and that they may encode unique functional capabilities enabling successful competition in a wide range of freshwater environments. Phylogenomic analysis of genes found on these GOS scaffolds suggests that some of the freshwater PRs are found in freshwater Flavobacteria and freshwater SAR11-like bacteria.
Involvement of iNOS and NO in TNF‐α–downregulated Resistin Gene Expression in 3T3‐L1 Adipocytes
Authors: Juan Chi‐Chang , Lien Chih‐Chen , Chang Chih‐Ling , Huang Yu‐Han , Ho Low‐Tone
Published: March 2008

Objective: In order to characterize the regulation of resistin gene expression, we explore the effect of tumornecrosis factor‐α (TNF‐α) on resistin mRNA expression and its underlying mechanism in 3T3‐L1 adipocytes.

Methods and Procedures: Differentiated 3T3‐L1 adipocytes were treated for 24 h with 0–10 ng/ml of TNF‐α or with 2.5 ng/ml of TNF‐α for 0–24 h, and then resistin mRNA levels were measured by northern blotting. To further explore the involvement of nitric oxide (NO) in TNF‐α–regulated resistin expression, the effect of the NO donor, sodium nitroprusside (SNP), on resistin mRNA levels in adipocytes and the effect of the nitric oxide synthase (NOS) inhibitors, NG‐nitro‐l‐arginine methyl ester (l‐NAME), and S, S′−1,3‐phenylene‐bis(1,2‐ethanediyl)‐bis‐isothiourea·2HBr (PBITU), on the TNF‐α effect in adipocytes were examined. The effects of TNF‐α on inducible NOS (iNOS) protein expression in adipocytes were also measured by western blotting.

Results: Our results showed that TNF‐α caused a dose‐dependent reduction in resistin mRNA levels. This effect seemed to be associated with the TNF‐α–induced expression of iNOS. The results showed that TNF‐α induced iNOS expression and release of NO after 24‐h treatment of differentiated 3T3‐L1 adipocytes. Pretreatment with l‐NAME and PBITU significantly reversed the TNF‐α–induced downregulation of resistin expression, while treatment with SNP mimicked the inhibitory effect of TNF‐α on resistin expression. In addition, pretreatment with protein tyrosine kinase (PTK) inhibitors, genistein and AG‐1288, prevented TNF‐α–induced iNOS expression and subsequent resistin downregulation.

Discussion: Our data suggest that TNF‐α suppresses resistin expression by inducing iNOS expression, thus causing overproduction of NO, which downregulates resistin gene expression.
NASH Predicts Plasma Inflammatory Biomarkers Independently of Visceral Fat in Men
Authors: Targher Giovanni , Bertolini Lorenzo , Rodella Stefano , Lippi Giuseppe , Franchini Massimo , Zoppini Giacomo , Muggeo Michele , Day Christopher P.
Published: March 2008

We assessed the differential contribution of nonalcoholic steatohepatitis (NASH) and visceral adiposity to nontraditional cardiovascular risk biomarkers in adult men. We enrolled 45 consecutive, overweight, male patients with biopsy‐proven NASH, 45 overweight male patients without ultrasound‐diagnosed hepatic steatosis, and 45 healthy male volunteers. All participants were matched for age; NASH and overweight patients were also matched for BMI and visceral adiposity (as estimated by abdominal ultrasonography). Nontraditional cardiovascular risk biomarkers were measured in all participants. Plasma concentrations of high‐sensitivity C‐reactive protein (hs‐CRP), fibrinogen, plasminogen activator inhibitor‐1 (PAI‐1) activity, and adiponectin were markedly different among the groups; the lowest values (the highest for adiponectin) were in nonobese healthy subjects, intermediate in overweight nonsteatotic patients, and the highest (the lowest for adiponectin) in those with biopsy‐proven NASH. The marked differences in these cardiovascular risk biomarkers that were observed between overweight and NASH patients were only slightly weakened after adjustment for age, BMI, smoking, plasma triglycerides, and insulin resistance (IR) as assessed by homeostasis model assessment (HOMA). In multivariate regression analysis, NASH and visceral adiposity predicted cardiovascular risk biomarkers independently of potential confounders. In conclusion, our results suggest that NASH can predict a more atherogenic risk profile in a manner that is partly independent from the contribution of visceral adiposity in adult men.
Gene‐environment Association of an ITGB2 Sequence Variant With Obesity in Ethnic Japanese
Authors: Awaya Tomokazu , Yokosaki Yasuyuki , Yamane Kiminori , Usui Hiroshi , Kohno Nobuoki , Eboshida Akira
Published: March 2008

Mice lacking the integrin αMβ2 (Mac‐1, CD11b/CD18) develop an obese phenotype on western diet rich in fat. However, no association has been found between variations in the human genes encoding the integrin αMβ2 and obesity. This study was aimed to investigate the association between a single‐nucleotide polymorphism (SNP) (rs235326) in the gene encoding human integrin β2 subunit (ITGB2) with obesity. Our subject cohort comprised 651 people of Japanese ethnicity, of which 274 were Japanese Americans living in Hawaii, and the remaining 377 were native Japanese, two populations in the same genetic background with or without westernized life style. We genotyped the rs235326 polymorphism using a TaqMan assay. In the Japanese‐American population, the risk of obesity was found to be 3.29‐fold higher (a 95% confidence interval of 1.25–8.67, P = 0.02) in TT homozygotes than in C carriers, using a recessive model and logistic regression analysis that had been adjusted for age. This association was not found in native Japanese individuals. These results indicate that the rs235326 polymorphism in the ITGB2 gene is associated with obesity in Japanese living in the United States whose diet has become “westernized.”
Long‐term Effects of Maternal Magnesium Restriction on Adiposity and Insulin Resistance in Rat Pups
Authors: Venu Lagishetty , Padmavathi Inagadapa J.N. , Kishore Yedla D. , Bhanu Nandiwada V. , Rao Kalashikam R. , Sainath Pothaganti B. , Ganeshan Manisha , Raghunath Manchala
Published: March 2008

Objective: We investigated the long‐term effects of maternal/postnatal magnesium (Mg) restriction on adiposity, glucose tolerance, and insulin secretion in the offspring and the probable biochemical mechanisms associated with them.

Methods and Procedures: Female weanling Wistar/NIN (WNIN) rats received a control diet or 70% Mg‐restricted (MgR) diet for 9 weeks and mated with control males. A third of the restricted dams were shifted to control diet from parturition. Half of the pups born to the remaining restricted dams were weaned on to control diet, while the other half continued on MgR diet. Various parameters were determined in the offspring at 18 months of age.

Results: The percentage of body fat increased, lean body mass (LBM) and fat free mass (FFM) decreased in restricted offspring and were irreversible by rehabilitation. While glucose tolerance and insulin resistance (IR) were comparable among groups, glucose‐stimulated insulin secretion and basal glucose uptake by the diaphragm were significantly decreased in restricted offspring and not corrected by rehabilitation. Plasma leptin was lower, and tumor necrosis factor‐α (TNF‐α) was higher in restricted offspring, whereas expression of fatty acid synthase (FAS) and fatty acyl transport protein 1 (FATP 1) was higher in liver and adipose tissue. While changes in FAS and FATP 1 were not correctible by rehabilitation, those in leptin and TNF‐α were corrected by rehabilitation from parturition but not from weaning. Tissue oxidative stress and antioxidant status were comparable among groups.

Discussion: Results indicate that maternal and postnatal Mg status is important in the long‐term programming of body adiposity and insulin secretion in rat offspring.
Sparsely synchronized neuronal oscillations
Authors: Brunel Nicolas , Hakim Vincent
Published: March 2008

We discuss here the properties of fast global oscillations that emerge in networks of neurons firing irregularly at a low rate. We first provide a simple introduction to these sparsely synchronized oscillations, then show how they can be studied analytically in the simple setting of rate models and leaky integrate-and-fire neurons, and finally describe how various neurophysiological features can be incorporated in this framework. We end by a comparison of experimental data and theoretical results.
Magnetic anisotropic behavior in epitaxial La2∕3Ca1∕3MnO3∕YBa2Cu3O7−δ∕La2∕3Ca1∕3MnO3 and La2∕3Ca1∕3MnO3∕La1∕3Ca2∕3MnO3∕YBa2Cu3O7−δ trilayered structures
Authors: Morán O. , Perez F. , Saldarriaga W. , Gross K. , Baca E.
Published: March 2008

The temperature dependence of the magnetization along with magnetization hysteresis loops were measured on dc sputtered La2∕3Ca1∕3MnO3[ferromagnetic(F)]∕YBa2Cu3O7−δ[superconductor(S)]∕La2∕3Ca1∕3MnO3(F) and La2∕3Ca1∕3MnO3(F)∕La1∕3Ca2∕3MnO3[antiferromagnetic(AF)]∕YBa2Cu3O7δ(S) trilayered structures. The magnetic fields were applied both parallel (in-plane) and perpendicular (out-of-plane) to the film plane. Magnetization hysteresis loops, recorded at 5K, shown a clear central peak around zero field when the magnetic field was applied perpendicular to the film plane and a typical ferromagnetic behavior when applied parallel. Additionally, the dependence of the magnetization on the temperature, performed under the zero-field-cooling (ZFC) and field-cooling (FC) regimens, evidenced the active presence of the diamagnetic and ferromagnetic phases both in the F∕S∕F and F∕AF∕S trilayers. Thus, the diamagnetic phase was clearly observed under the ZFC regimen, whereas a possible paramagnetic Meissner effect was observed under the FC regimen.
Magnetoresistance in Co∕Pt based magnetic tunnel junctions with out-of-plane magnetization
Authors: Ducruet C. , Carvello B. , Rodmacq B. , Auffret S. , Gaudin G. , Dieny B.
Published: March 2008

Submicron magnetic tunnel junctions exhibiting perpendicular magnetic anisotropy have been prepared by sputtering. They associate a hard and a soft electrode based on Co∕Pt multilayers, separated by an amorphous alumina barrier. The soft electrode is either free or exchange biased by an antiferromagnetic layer. The magnetoresistance ratio reaches 8% at room temperature after patterning junctions with diameter down to 200nm. The macroscopic magnetic properties were investigated by extraordinary Hall effect and conventional magnetometry measurements. The magnetic moments of both electrodes are out of plane. Two well-separated switching fields allow the realization of well-defined parallel and antiparallel configurations of the magnetizations.
On the validity of the Arrhenius equation for electron attachment rate coefficients
Authors: Fabrikant Ilya I. , Hotop Hartmut
Published: March 2008

The validity of the Arrhenius equation for dissociative electron attachment rate coefficients is investigated. A general analysis allows us to obtain estimates of the upper temperature bound for the range of validity of the Arrhenius equation in the endothermic case and both lower and upper bounds in the exothermic case with a reaction barrier. The results of the general discussion are illustrated by numerical examples whereby the rate coefficient, as a function of temperature for dissociative electron attachment, is calculated using the resonance R-matrix theory. In the endothermic case, the activation energy in the Arrhenius equation is close to the threshold energy, whereas in the case of exothermic reactions with an intermediate barrier, the activation energy is found to be substantially lower than the barrier height.
Basis-set limit of the aurophilic attraction using the MP2 method: The examples of [ClAuPH3]2 dimer and [P(AuPH3)4]+ ion
Authors: Pyykkö Pekka , Zaleski-Ejgierd Patryk
Published: March 2008

The basis-set limit of the aurophilic attraction is studied at the MP2 level for the free model dimer [ClAuPH3]2 and for a [P(AuPH3)4]+ ion. The latter system is found to prefer a C4v symmetry, instead of Td, in agreement with Li and Pyykkö [Inorg. Chem. 32, 2630 (1993)] but in contradiction to recent results of Fang and Wang [J. Phys. Chem. A. 111, 1562 (2006)]. The Karlsruhe split valence and the Dunning correlation-consistent basis sets converge to the same limit.
Changes in single-walled carbon nanotube chirality during growth and regrowth
Authors: Zhu Wuming , Rosén Arne , Bolton Kim
Published: March 2008

A simple model for joining two single-walled carbon nanotubes (SWNTs) with different, arbitrary chiralities is used to systematically label junction structures which contain pentagon-heptagon pairs. The model is also used, together with density functional theory, to study the energetics of diameter and chirality changes of thin SWNTs during catalyzed growth or regrowth. We choose zigzag and armchair SWNTs attached to a Ni55 cluster for our case studies.
Wave celerity on a shear-thinning fluid film flowing down an incline
Authors: Millet S. , Botton V. , Rousset F. , Ben Hadid H.
Published: March 2008

This letter presents a phenomenological model predicting the celerity of long surface waves on a non-Newtonian fluid flowing down an inclined plane. We show that, for a shear-thinning fluid, the celerity is greater than the well-known value c=2U0. The developed model points at the significant effect of the viscosity disturbance and also provides a likely explanation for the decrease in threshold for the instability.
Asymmetric electrical bistable behavior of an eicosanoic acid/zirconium oxide bilayer system with rectifying effect
Authors: Tu Deyu , Liu Ming , Shang Liwei , Liu Xinghua , Xie Changqing
Published: March 2008

The electrical switching characteristics of eicosanoic acid (EA)/zirconium oxide (ZrO2) bilayer thin films are investigated in this letter. The devices have a sandwich structure of aluminum (Al)∕EA∕ZrO2∕gold (Au) and exhibit asymmetric electrical bistable behavior with a rectifying effect through resistive switching. Reversible and reproducible bistable switching properties were observed by applying certain voltages. The asymmetry and rectifying bistable behavior is proposed to result from the Schottky barrier that is present by reason of the ZrO2 layer. The rectifying effect can significantly improve misreading in matrix crossbar memory based on bistable two-terminal devices, paving a way for a practical crossbar molecular memory.
Solitons in dusty plasmas with positive dust grains
Authors: Baluku T. K. , Hellberg M. A. , Mace R. L.
Published: March 2008

Although “typical” micrometer-sized dust grains in a space or laboratory plasma are often negatively charged because of collisions with the mobile electrons, there are environments in which grains may take on a positive charge. We consider a dusty plasma composed of electrons, positive ions and positive dust grains, and use the fluid dynamic paradigm to identify existence domains in parameter space for both dust-acoustic (DA) and dust-modified ion-acoustic (DIA) solitons. Only positive potential DA solitons are found. This represents an expected antisymmetry with the case of negative dust, where previously only negative solitons were reported. However, whereas for negative dust DIA solitons of either sign of potential may exist, we find that for the case of positive dust, DIA solitons are restricted to positive potentials only. The results for both positive and negative dust are consistent with an hypothesis that, in the absence of flows, the sign(s) of the soliton potential coincide(s) with the sign(s) of the species whose inertia is included in the calculation; i.e., the cold, supersonic species present in the plasma.
Influence of oxygen vacancies on Schottky contacts to ZnO
Authors: Allen M. W. , Durbin S. M.
Published: March 2008

Ni, Ir, Pd, Pt, and silver oxide Schottky contacts were fabricated on the Zn-polar face of hydrothermally grown, bulk ZnO. A relationship was found between the barrier height of the contact and the free energy of formation of its “metal” oxide. This is consistent with the dominating influence of oxygen vacancies (VO) which tend to pin the ZnO Fermi level close to the VO (+2,0) defect level at approximately 0.7eV below the conduction band minimum. Therefore, a key goal in the fabrication of high quality Schottky contacts should be the minimization of oxygen vacancies near the metal-ZnO interface.
Thermal conductivity/diffusivity of Nd3+ doped GdVO4, YVO4, LuVO4, and Y3Al5O12 by temperature wave analysis
Authors: Morikawa Junko , Leong Ceelia , Hashimoto Toshimasa , Ogawa Takayo , Urata Yoshiharu , Wada Satoshi , Higuchi Mikio , Takahashi Jun-ichi
Published: March 2008

Thermal diffusivity and thermal conductivity of single crystals of Nd3+ doped GdVO4, YVO4, LuVO4, and Y3Al5O12 are precisely measured over a wide range of doping concentration from 0.5to15at.% by temperature wave analysis. Thermal diffusivity serves as the most sensitive parameter to detect the effect of doping on thermal properties, where Nd3+ doped GdVO4 exhibits a decrease in thermal diffusivity (it has changed about 20% in their values in the c axis) but an increase in heat capacity (only 1.7%). It has long been understood that the thermal conductivity of YVO4 is inferior to that of Y3Al5O12; however, the thermal conductivity of YVO4 in the c axis shows the highest value in all four crystals compared at 1at.% of Nd3+ doping concentration. Thermal conductivity exhibits a decrease (∝ε−1∕2, ε: mass variance) with an increase of doping concentration, that is characteristic of Klemens’ point defect model for the phonon scattering. In the numerical fitting, the anisotropic decrease of thermal conductivity in different crystal axes, [100], [001], and [110], is reflected as the different phonon velocities. The simulated and the experimental thermal conductivity show the various decreasing curvatures indicating that the effect of mass difference of the host and the doping cations serves as an important factor, as with the crystallographic anisotropy, on the thermal conductivity of the doped single crystals.
Neutron reflectometry study of hydrogen desorption in destabilized MgAl alloy thin films
Authors: Fritzsche H. , Saoudi M. , Haagsma J. , Ophus C. , Luber E. , Harrower C. T. , Mitlin D.
Published: March 2008

We studied the hydrogen absorption and desorption properties of thin Pd-covered Mg1−xAlx alloy films as a function of temperature and alloy composition. Using neutron reflectometry, we were able to determine the hydrogen content and the hydrogen distribution within these MgAl films in situ. For all films, hydrogen was uniformly dispersed within the MgAl film and no hydrogen was observable in the Pd cover layer. The Mg0.7Al0.3 film shows an appreciable 4.1wt% stored hydrogen and improved desorption characteristics with complete desorption at a temperature of 448K.
Soft x-ray source for nanostructure imaging using femtosecond-laser-irradiated clusters
Authors: Fukuda Y. , Faenov A. Ya. , Pikuz T. , Kando M. , Kotaki H. , Daito I. , Ma J. , Chen L. M. , Homma T. , Kawase K. , Kameshima T. , Kawachi T. , Daido H. , Kimura T. , Tajima T. , Kato Y. , Bulanov S. V.
Published: March 2008

The intense soft x-ray light source using the supersonic expansion of the mixed gas of He and CO2, when irradiated by a femtosecond Ti:sapphire laser pulse, is observed to enhance the radiation of soft x-rays from the CO2 clusters. Using this soft x-ray emissions, nanostructure images of 100-nm-thick Mo foils in a wide field of view (mm2 scale) with high spatial resolution (800nm) are obtained with high dynamic range LiF crystal detectors. The local inhomogeneities of soft x-ray absorption by the nanometer-thick foils is measured with an accuracy of less than ±3%.
Composition profiles within Al3Li and Al3Sc∕Al3Li nanoscale precipitates in aluminum
Authors: Krug Matthew E. , Dunand David C. , Seidman David N.
Published: March 2008

An Al–11.3Li–0.11Sc (at. %) alloy was double aged to induce first α′-Al3Sc and then δ′-Al3Li precipitates. Atom-probe tomography revealed both single-phase δ′-precipitates and core-shell α′∕δ′-precipitates (with respective average radii of 16 and 27nm and respective volume fractions of 12% and 9%) conferring a high strength to the alloy. Although the δ′-shells contain little Sc (∼0.027at.%), the α′-cores have a high Li content, with an average composition of Al0.72(Sc0.17Li0.11). The Li concentrations within the δ′-phase and the Li interfacial excess at the δ′∕α′-interface both exhibit wide precipitate-to-precipitate variations.