bluuebunny/crossref_metadata_2025 huggingface dataset:
Sacredness in an experimental chamber
Authors: Lefebvre Vladimir A.
Published: February 2007

I focus on the problem of whether a specific biologic basis exists for reinforcing the power of money. I argue in favor of its existence based on a new interpretation of data obtained in experiments with pigeons and rats in an experimental chamber. The experiments demonstrated that in the animals' behavior we can observe some features that had been considered pertinent to human beings only, such as making certain sources of utility “sacred.”
Cruelty's utility: The evolution of same-species killing
Authors: Potts Malcolm
Published: February 2007

Human beings, like chimpanzees, deliberately kill their own species in order to expand their territory. For a self-aware social animal to attack its own kind, it would need to evolve a mechanism to dehumanize, or “dechimpanzee-ize” those it attacks. It is suggested that cruelty reflects such an evolved predisposition. The implications for violence prevention are discussed.
Animal cruelty: Definitions and sociology
Authors: Rowan Andrew Nicholas
Published: February 2007

The definition of cruelty used by the author is broad and ambiguous and does not distinguish between acts of sadism, abuse, and neglect that all lead to the suffering of other beings. Some of the research involving animal cruelty is reviewed with the aim of raising questions about the relevance of the pain–blood–death (PBD) complex described by Nell.
How relevant are fluid cognition and general intelligence? A developmental neuroscientist's perspective on a new model
Authors: Wilke Marko
Published: February 2007

Blair boldly proposes a model integrating different aspects of intelligence. Its real-life value can be put to the test by using programs designed to develop children's abilities in areas predicted to be crucial for minimizing adverse outcome. Until support from such programs is available, the model is an interesting hypothesis, albeit with remarkable possible repercussions. As such, it seems worthy of further development.
Language and life history: Not a new perspective
Authors: Ragir Sonia , Brooks Patricia J.
Published: February 2007

The uniqueness of human cognition and language has long been linked to systematic changes in developmental timing. Selection for postnatal skeletal ossification resulted in progressive prolongation of universal patterns of primate growth, lengthening infancy, childhood, and adolescence. Language emerged as communication increased in complexity within and between communities rather than from selection for some unique features of childhood or adolescence, or both.
Memetics and money
Authors: Stanovich Keith E.
Published: February 2007

Lea & Webley's (L&W's) Drug Theory solves many puzzles surrounding money-related behavior. I explore supplementing the Drug Theory with ideas from gene-culture coevolution theory and memetic theory.
Uniqueness of human childhood and adolescence?
Authors: Weisfeld Glenn E.
Published: February 2007

Locke & Bogin (L&B) propose that humans are unique in possessing stages of childhood and adolescence. Arguments to the contrary include evidence for a similar and adaptive juvenile period in simians of slow growth, intense play and learning, and provisioning with solid food by adults. Likewise, simians as well as humans undergo a compensatory growth spurt during puberty.
Torturers, horror films, and the aesthetic legacy of predation
Authors: Tiger Lionel
Published: February 2007

A Rousseauist bias towards the study of human aggression has treated it as a regrettable anomaly rather than a volatile reflection of important forces in human evolution. Intrepidly, Nell displays the arc of connection between predation in humans and other animals and the neurophysiological factors that underlie chronic interest in accident, death, and harsh force.
“Language impairment gene” does not necessarily equate to “language gene”
Authors: Workman Lance
Published: February 2007

The finding of the same language deficit in half the members of the KE family is taken as suggesting that a specific allele (FOXP2) is normally involved in the development of language. Recent studies, however, question the exclusivity of FOXP2, and it is argued that the finding of a gene that disrupts language should not be taken as strong evidence for the existence of genes that underlie it.
Life history and language: Selection in development
Authors: Locke John L. , Bogin Barry
Published: February 2007

Language, like other human traits, could only have evolved during one or more stages of development. We enlist the theoretical framework of human life history to account for certain aspects of linguistic evolution, with special reference to initial phases in the process. It is hypothesized that selection operated at several developmental stages, the earlier ones producing new behaviors that were reinforced by additional, and possibly more powerful, forms of selection during later stages, especially adolescence and early adulthood. Peer commentaries have provided opportunities to explain human life history more comprehensively, and to add details to our account of spoken language. We made no attempt to explain syntax in the target article, but we propose here that selection for “vocal plumage” may have increased our species’ capacity for utterance complexity, a development that would have benefited all levels of language.
Do Depressive Symptoms Differ Between Medically Ill and Non-Medically Ill Patients Referred for Psychological Therapy? Comparing Negative Thoughts about the Self in Cancer and Non-Cancer Patients
Authors: Moorey Stirling , Steiner Herbert
Published: February 2007

Negative thoughts about the self are a core component of Beck's cognitive triad of depression, and are seen by some as the central cognitive symptom of the disorder. The role of negative thoughts about the self in secondary depression associated with medical illness is less clear: thoughts relating to hopelessness and helplessness rather than guilt, self blame and failure may be more prominent. This study tested the hypothesis that the cognitive symptoms of depression in cancer patients would be less negatively self-referent than a psychiatric control group. Forty patients with cancer referred to a psychological medicine department were matched for age, sex and BDI score with 40 patients referred to a psychological therapies department for CBT. The cognitive-affective section of the BDI (items 1–14) was divided into a negative self-referent cognitions subscale (items 3, 5, 7, 8) and a mood-motivation subscale. These two subscales were then compared with the somatic-performance subscale (items 15–21). As a percentage of the total matched BDI score, the cancer patients had more somatic symptoms (42.7 v 34.8%), equivalent mood/motivation symptoms (44.5 v 45.6%) and less negative self-referent symptoms (12.8 v 19.5%). This difference may apply more to mild symptoms than moderate-severe symptoms. Some preliminary support for the hypothesis is therefore available.
Improving Performance of Mammalian Cells in Fed‐Batch Processes through “Bioreactor Evolution”
Authors: Prentice Holly L. , Ehrenfels Barbara N. , Sisk William P.
Published: February 2007

The amount of recombinant product obtained from mammalian cells grown in a bioreactor is in part limited by achievable cell densities and the ability of cells to remain viable over extended periods of time. In an attempt to generate cell lines capable of better bioreactor performance, we subjected the DG44 Chinese Hamster Ovary (CHO) host cell line and a recombinant production cell line to an iterative process whereby cells capable of surviving the harsh conditions in the bioreactor were selected. This selective process was termed “bioreactor evolution”. Following the selective process, the “evolved” host cells attained a 2‐fold increase in peak cell density and a 72% increase in integral cell area. Transient transfection experiments demonstrate that the evolved cells have the same transfection efficiency and the same secretory potential as the initial cells. The “evolved” host was also found to contain a large subpopulation of cells that did not require insulin for growth. From this, a new population of growth‐factor‐independent cells was obtained. These improvements in host properties should prove beneficial in the expression of recombinant proteins in fed‐batch processes. The selective process was also applied to a recombinant production cell line. The evolved cells from this selection exhibited a 38% increase in peak cell density, a 30% increase in integral cell area, and a 36% increase in product titer. These increases were obtained without any appreciable impact on product quality, demonstrating the usefulness of this simple approach to improve the performance of recombinant cell lines.
In einem Lauf vom Bodensee an den Genfersee – Effekt auf Fett- und Muskelmasse
Authors: Knechtle  , Knechtle
Published: February 2007

Ein Langstreckenläufer hat die Strecke Rorschach-Vevey über rund 320 km mit fast 7000 Höhenmetern bei Temperaturen um 10° Celsius in 54 Stunden zurückgelegt. Dabei nahm er rund 15000 kcal auf, verbrauchte über 18000 kcal und ging ein Energiedefizit von über 3000 kcal ein. Es resultierte eine Abnahme des Körpergewichts um 0.400 kg, die Muskelmasse nahm um 1.020 kg und die Fettmasse um 0.300 kg ab.
An objective ocean temperature and salinity analysis using covariances from a global climate model
Authors: Smith Doug M. , Murphy James M.
Published: February 2007

Covariances are crucial for propagating information from data‐rich to data‐sparse regions, but owing to the sparsity of observations, previous analyses of subsurface ocean temperature and salinity have employed fairly crude parameterizations of covariances defined at resolutions much coarser than the required analysis. Here we investigate the use of covariances computed directly from a realistic coupled global climate model, HadCM3. We demonstrate that 50 to 80% of the monthly variance of both temperature and salinity at 300 m for the period 1950 to 2004 could potentially be captured by analyses based on perfect covariances. However, because of errors in the HadCM3 covariances, we estimate that our analysis captures on average 40% and 25% of the variance of temperature and salinity anomalies in the upper 300 m for this period, although we project both these percentages to increase to about 70% for future analyses benefiting from the full ARGO array. Assessed against tide gauge and altimeter data, our analysis is comparable to that of Ishii et al. (2003) (I03). However, the simple average of our analysis and I03 provides a clear improvement over I03. This improvement probably arises partly from additional observations and partly because errors in covariances will be reduced by taking the mean of an ensemble which samples their uncertainty. We recommend sampling all sources of uncertainty in future ensemble analyses, and anticipate that statistics from future more realistic climate models will become increasingly important to such an ensemble.
Impacts of meteorological uncertainties on ozone pollution predictability estimated through meteorological and photochemical ensemble forecasts
Authors: Zhang Fuqing , Bei Naifang , Nielsen‐Gammon John W. , Li Guohui , Zhang Renyi , Stuart Amy , Aksoy Altug
Published: February 2007

This study explores the sensitivity of ozone predictions from photochemical grid point simulations to small meteorological initial perturbations that are realistic in structure and evolution. Through both meteorological and photochemical ensemble forecasts with the Penn State/NCAR mesoscale model MM5 and the EPA Community Multiscale Air Quality (CMAQ) Model‐3, the 24‐hour ensemble mean of meteorological conditions and the ozone concentrations compared fairly well against the observations for a high‐ozone event that occurred on 30 August during the Texas Air Quality Study of 2000 (TexAQS2000). Moreover, it was also found that there were dramatic uncertainties in the ozone prediction in Houston and surrounding areas due to initial meteorological uncertainties for this event. The high uncertainties in the ozone prediction in Houston and surrounding areas due to small initial wind and temperature uncertainties clearly demonstrated the importance of accurate representation of meteorological conditions for the Houston ozone prediction and the need for probabilistic evaluation and forecasting for air pollution, especially those supported by regulating agencies.
Chemical composition of marine stratocumulus clouds over the eastern Pacific Ocean
Authors: Straub Derek J. , Lee Taehyoung , Collett Jeffrey L.
Published: February 2007

Samples of marine cloud water collected over the eastern Pacific Ocean have been analyzed for pH, major ions (Cl−, NO3−, SO42−, Na+, NH4+, K+, Ca2+, and Mg2+), hydrogen peroxide, formaldehyde, S(IV), Fe, Mn, and total organic carbon. The samples were obtained during the Dynamics and Chemistry of Marine Stratocumulus, Phase II (DYCOMS‐II) field project in July 2001. These measurements represent a unique in situ description of cloud water composition for stratocumulus clouds residing in the remote marine boundary layer, a regime for which there are few published cloud water composition data. A wide range of concentrations was observed for each species of interest, including sodium (36–2784 μN), sulfate (15–905 μN), nitrate (3–205 μN), hydrogen peroxide (37.8–283.2 μM), formaldehyde (2.2–8.7 μM) and Fe (<MDL–85.9 μg L−1). Chloride and potassium were present in expected seawater ratios while sulfate, magnesium, and calcium were enriched to varying degrees. Trends in cloud water concentrations with cloud liquid water content (LWC) and volume mean drop diameter show that dilution played a role in cloud drop solute concentration variations during individual flights and that solute concentrations are related to cloud drop size and ultimately to below‐cloud aerosol number concentration. Air equivalent concentrations (the amount of a solute in cloud water per unit volume of air) were derived in order to eliminate concentration dependence on LWC and to allow comparison with previous aerosol, trace gas, and cloud water studies. The analysis indicates that background marine conditions were not always encountered during the DYCOMS‐II mission as a result of anthropogenic or biogenic sources impacting the study region.
Four‐dimensional GPS imaging of space weather storms
Authors: Bust G. S. , Crowley G. , Garner T. W. , Gaussiran T. L. , Meggs R. W. , Mitchell C. N. , Spencer P. S. J. , Yin P. , Zapfe B.
Published: February 2007

Recent developments in tomographic imaging allow the use of GPS satellite data to image the Earth's ionosphere. Ground‐based GPS receivers monitor the Earth's ionosphere continuously, and a comprehensive database of ionospheric measurements suitable for tomographic processing now exists. The tomographic inversion of these GPS data in a three‐dimensional time‐dependent inversion algorithm can reveal the spatial and temporal distribution of ionospheric electron density. This new technique is unique for studying ionospheric physics because it gives a time‐continuous near‐global view of the ionosphere. The tomographic algorithms have been under continuous development for several years and are now yielding new geophysical results. Two fundamentally different algorithms (Multi‐instrument Data Analysis System and Ionospheric Data Assimilation Three‐Dimensional) are presented. They show the ionospheric impact of two major space weather events during the recent solar maximum. Results obtained from these two algorithms are similar, which provides additional confidence in the accuracy of the images.
Spatial and temporal variations in bed load transport intensity in a gravel bed river bend
Authors: Clayton Jordan A. , Pitlick John
Published: February 2007

Variability in bed load sediment transport is investigated for a bend of the Colorado River in Rocky Mountain National Park. Data from 190 bed load samples taken at 50 to 125% bankfull flow at a large number of locations throughout the reach indicate that the fine and coarse fractions of the load are differentially routed, such that fine grains are swept inward over the point bar, while coarse grains are routed outward toward the pool. At bankfull flow, all size fractions of the available sediment are transported throughout the bend, but the median grain size of the bed load increases with distance toward the outer bank. This differential routing decreases slightly with increasing discharge beyond bankfull, as indicated by a shift in the locus of coarse particle transport from the outside of the bend inward to the channel center. Furthermore, while fine sediments are fully mobile throughout the bend, partial mobility of the coarse fractions of the load transitions to full mobility toward the bend's outer region. These patterns are flow dependent; with increasing discharge the distribution of excess Shields stress becomes more uniform, resulting in reduced variability in bed load transport rates across the channel. These variations in transport intensity lead to a volumetric balance of transported sediment between the inner and outer regions of the channel, which thereby promotes the geomorphic stability of the bend.
Evaluation of Methods for Generating Parametric (R)-[11C]PK11195 Binding Images
Authors: Schuitemaker Alie , van Berckel Bart NM , Kropholler Marc A , Kloet Reina W , Jonker Cees , Scheltens Philip , Lammertsma Adriaan A , Boellaard Ronald
Published: February 2007

Activated microglia can be visualised using ( R)-[11C]PK11195 (1-[2-chlorophenyl]- N-methyl- N-[1-methyl-propyl]-3-isoquinoline carboxamide) and positron emission tomography (PET). In previous studies, various methods have been used to quantify ( R)-[11C]PK11195 binding. The purpose of this study was to determine which parametric method would be best suited for quantifying ( R)-[11C]PK11195 binding at the voxel level. Dynamic ( R)-[11C]PK11195 scans with arterial blood sampling were performed in 20 healthy and 9 Alzheimer's disease subjects. Parametric images of both volume of distribution ( Vd) and binding potential ( BP) were obtained using Logan graphical analysis with plasma input. In addition, BP images were generated using two versions of the basis function implementation of the simplified reference tissue model, two versions of Ichise linearisations, and Logan graphical analysis with reference tissue input. Results of the parametric methods were compared with results of full compartmental analysis using nonlinear regression. Simulations were performed to assess accuracy and precision of each method. It was concluded that Logan graphical analysis with arterial input function is an accurate method for generating parametric images of Vd. Basis function methods, one of the Ichise linearisations and Logan graphical analysis with reference tissue input provided reasonably accurate and precise estimates of BP. In pathological conditions with reduced flow rates or large variations in blood volume, the basis function method is preferred because it produces less bias and is more precise.
Bacterial Hydrogen Peroxide Contributes to Cerebral Hyperemia during Early Stages of Experimental Pneumococcal Meningitis
Authors: Hoffmann Olaf M , Becker Doreen , Weber Joerg R
Published: February 2007

Alterations of blood flow contribute to major clinical complications in invasive infections such as sepsis and bacterial meningitis. As a unique feature streptococci – in particular, Streptococcus pneumoniae, the most frequent pathogen in bacterial meningitis – release hydrogen peroxide (H2O2) because of the absence of functional catalase. In a 6 h rat model of experimental meningitis, we studied the impact of bacterial H2O2 production on regional cerebral blood flow (rCBF) and intracranial pressure (ICP). Compared to wild-type D39 pneumococci, the increase of rCBF was diminished in meningitis induced by the H2O2 defective SpxB− mutant (maximum increase, 135% ± 17% versus 217% ± 23% of the individual baseline; P < 0.01) or after treatment of D39-induced meningitis with H2O2-degrading catalase or with tetraethylammonium (TEA), a blocker of calcium-sensitive potassium channels, which mediate H2O2-induced vasodilation. Catalase did not significantly reduce the remaining rCBF increase caused by SpxB−, supporting the predominant role of bacterial H2O2. We conclude that in addition to host-sided mediators, bacterial-derived H2O2 acts as a potent vasodilator, which accounts for a certain proportion of the early cerebral hyperperfusion in pneumococcal meningitis.
Analysis of cross peaks in two-dimensional electronic photon-echo spectroscopy for simple models with vibrations and dissipation
Authors: Egorova Dassia , Gelin Maxim F. , Domcke Wolfgang
Published: February 2007

The recently developed efficient method for the calculation of four-wave mixing signals [M. F. Gelin et al., J. Chem. Phys. 123, 164112 (2005)] is employed for the calculation of two-dimensional electronic photon-echo spectra. The effect of the explicit treatment of vibrations coupled to the electronic transitions is systematically analyzed. The impact of pulse durations, optical dephasing, and temperature on the spectra is investigated. The study aims at an understanding of the mechanisms which may give rise to cross peaks in the two-dimensional electronic spectra and at clarifying the conditions of their detection.
Quantum-classical dynamics of wave fields
Authors: Sergi Alessandro
Published: February 2007

An approach to the quantum-classical mechanics of phase space dependent operators, which has been proposed recently, is remodeled as a formalism for wave fields. Such wave fields obey a system of coupled nonlinear equations that can be written by means of a suitable non-Hamiltonian bracket. As an example, the theory is applied to the relaxation dynamics of the spin-boson model. In the adiabatic limit, a good agreement with calculations performed by the operator approach is obtained. Moreover, the theory proposed in this paper can take nonadiabatic effects into account without resorting to surface-hopping approximations. Hence, the results obtained follow qualitatively those of previous surface-hopping calculations and increase by a factor of (at least) 2, the time length over which nonadiabatic dynamics can be propagated with small statistical errors. Moreover, it is worth to note that the dynamics of quantum-classical wave fields proposed here is a straightforward non-Hamiltonian generalization of the formalism for nonlinear quantum mechanics that Weinberg introduced recently.
Effects of structural nonplanarity on the magnetoresistance of Permalloy circular rings
Authors: Vavassori P. , Busato A. , Chiapatti A. , di Bona A. , Valeri S. , Metlushko V. , Ilic B.
Published: February 2007

We have measured magnetoresistance in single, 1μm external diameter, Permalloy (Ni80Fe20) circular rings with inner diameters of 150, 300, and 600nm and film thickness of 25nm. The ring structures were deposited on 25-nm-thick, 250-nm-wide Au nanocontacts previously fabricated on a SiO2∕Si substrate by e-beam lithography. Using a four contact geometry, we studied the dependence of the magnetoresistance on the direction of the applied field. The experimental data were compared with simulations based on the conventional anisotropic magnetoresistance effect and on numerical simulations of the current distribution within the samples combined with micromagnetic simulations of the field dependent magnetization profile. Two different approaches were used for the simulations: one assumes flat magnetic structures with the Au contacts deposited on top of them; in the second approach the simulations were carried out using nonplanar magnetic structures deposited on the Au contacts. The magnetoresistance curves calculated using the second approach differ considerably from those obtained assuming flat magnetic structures and reproduce the experimental curves. The results presented demonstrate that the nonplanarity of the magnetic structures affects profoundly the magnetoresistive behavior of the ring structures.
Predicting adsorption isotherms using a two-dimensional statistical associating fluid theory
Authors: Martinez Alejandro , Castro Martin , McCabe Clare , Gil-Villegas Alejandro
Published: February 2007

A molecular thermodynamics approach is developed in order to describe the adsorption of fluids on solid surfaces. The new theory is based on the statistical associating fluid theory for potentials of variable range [A. Gil-Villegas et al., J. Chem. Phys. 106, 4168 (1997)] and uses a quasi-two-dimensional approximation to describe the properties of adsorbed fluids. The theory is tested against Gibbs ensemble Monte Carlo simulations and excellent agreement with the theoretical predictions is achieved. Additionally the authors use the new approach to describe the adsorption isotherms for nitrogen and methane on dry activated carbon.
Simulation of the effect of surface-oxide formation on bistability in CO oxidation on Pt-group metals
Authors: Zhdanov Vladimir P.
Published: February 2007

The kinetics of CO oxidation on Pt-group metals are known to often exhibit bistability. During the low-reactive regime observed at relatively high CO pressure, the surface is primarily covered by CO and the reaction rate is controlled by O2 dissociation. During the high-reactive regime at relatively low CO pressure, in contrast, the surface is mainly covered by oxygen and the reaction rate is proportional to CO pressure. In the latter case, the adsorbed oxygen may be in the chemisorbed state and/or may form surface oxide. The experiments indicate that the formation of surface oxide often occurs via the island growth and accordingly should be described in terms of the theory of first-order phase transitions. Here, the author proposes a generic lattice-gas model satisfying this requirement and allowing one to execute the corresponding Monte Carlo simulations. Systematically varying the model parameters determining the oxide stability, he classifies the likely scenarios of the bistable reaction kinetics complicated by oxide formation.
Characterization of sputtering products during graphite exposure to deuterium ions by molecular dynamics
Authors: Marian Jaime , Zepeda-Ruiz Luis A. , Couto Nicole , Bringa Eduardo M. , Gilmer George H. , Stangeby Peter C. , Rognlien Thomas D.
Published: February 2007

We study sputtering by 100eV deuterium irradiation on deuterated amorphous carbon layers at 300K using molecular dynamics (MD) simulations. Two main results are reported here. First, a special mechanism for carbon release—additional to and distinct from the standard definitions for physical and chemical sputtering of carbon by hydrogen isotopes—has been identified and quantified. This process, here termed ion induced release of unsaturated hydrocarbons (IRUH’s), is primarily due to a recently identified atomic collision process where momentum from an impacting particle is transferred approximately perpendicular to the C–C bond, severing it. For the prescribed conditions, the IRUH yield has been found to be comparable to that of standard physical and chemical sputtering, the former being also consistently and simultaneously calculated here. IRUH release of single C atoms does not involve any hydrogenic chemistry and is therefore properly considered to be a distinct and additive type of physical sputtering to that of standard physical sputtering. For 100eV D+ the single C yields of the two physical sputtering mechanisms have been found to be approximately equal. IRUH release of carbon is directly from the surface region of the solid and is separate from, and additional to, standard chemical sputtering (not included in these MD calculations), which typically produces saturated hydrocarbons such as CD4, from regions extending over the stopping depth of the deuteron in the solid. IRUH is evidently included in experimental measurements of total sputtering yield, e.g., by weight loss. The average energy of IRUH carbon products is about 1eV and the angular distribution is consistent with a cosine distribution. Second, it is found that for the standard physically sputtered single C atoms the energy distribution is roughly consistent with the widely used Thompson distribution—this despite the fact that the assumptions on which the Thompson distribution is based are not satisfied for 100eV D on C. The angular distribution of the standard physically sputtered single C atoms is also found to be consistent with the usually assumed cosine distribution.
Towards a structural characterization of an epoxy based polymer using small-angle x-ray scattering
Authors: Medhioub H. , Zerrouki C. , Fourati N. , Smaoui H. , Guermazi H. , Bonnet J. J.
Published: February 2007

The grazing incidence x-ray reflectometry was used in this study to characterize an epoxy based polymer (Striasol 500). The possibility of using complementarily reflection and transmission of diffuse x ray has been emphasized. Measurements were made in both “detector scan” and “rocking curve” modes. For the first mode, results have shown that this polymer presents locally a periodic character, with various spacing structures (from 32to74nm), while the rocking curve measurements revealed that the mean orientation of these structures is slightly tilted (about 0.01°) compared to the surface sample. Reproducibility measurements have been equally demostrated showing a short distance order, as the periodic structures are observed only on some parts of the analyzed sample. At last, a stability study has shown that the structure of superficial and deeper parts of polymer varies differently after 15months.
Patterned films of size-selected Au clusters on optical substrates
Authors: Palomba S. , Palmer R. E.
Published: February 2007

The deposition of clusters produced by gas phase aggregation is a powerful tool for tailoring nanostructured materials. We report the successful preparation of patterned size-selected AuN (N=300–23000) clusters, on various optical substrates (glass, quartz, polymethyl methacrylate, and mica), as relevant to applications in photonics. Characterization of the film morphologies by atomic force microscopy showed stable, monodispersed arrangement even months after deposition. Laser scanning confocal microscopy of the ensemble demonstrates that the Au cluster plasmon is preserved in these arrays.
White light emission from Eu3+ in CaIn2O4 host lattices
Authors: Liu Xiaoming , Lin Cuikun , Lin Jun
Published: February 2007

Ca In 2 O 4 : x Eu 3 +  (x=0.5%,1.0%,1.5%) phosphors were prepared by the Pechini sol-gel process [U.S. Patent No. 3,330,697 (1967)] and characterized by x-ray diffraction and photoluminescence and cathodoluminescence spectra as well as lifetimes. Under the excitation of 397nm ultraviolet light and low voltage electron beams, these phosphors show the emission lines of Eu3+ corresponding to D0,1,2,35-FJ7 (J=0,1,2,3,4) transitions from 400to700nm (whole visible spectral region) with comparable intensity, resulting in a white light emission with a quantum efficiency near 10%. The luminescence mechanism for Eu3+ in CaIn2O4 has been elucidated.
On the universality of the long-/short-range separation in multiconfigurational density-functional theory
Authors: Fromager Emmanuel , Toulouse Julien , Jensen Hans Jørgen Aa.
Published: February 2007

In many cases, the dynamic correlation can be calculated quite accurately and at a fairly low computational cost in Kohn-Sham density-functional theory (KS-DFT), using current standard approximate functionals. However, in general, KS-DFT does not treat static correlation effects (near degeneracy) adequately which, on the other hand, can be described in wave-function theory (WFT), for example, with a multiconfigurational self-consistent field (MCSCF) model. It is therefore of high interest to develop a hybrid model which combines the best of both WFT and DFT approaches. The merge of WFT and DFT can be achieved by splitting the two-electron interaction into long-range and short-range parts. The long-range part is then treated by WFT and the short-range part by DFT. In this work the authors consider the so-called “erf” long-range interaction erf(μr12)∕r12, which is based on the standard error function, and where μ is a free parameter which controls the range of the long-/short-range decomposition. In order to formulate a general method, they propose a recipe for the definition of an optimal μopt parameter, which is independent of the approximate short-range functional and the approximate wave function, and they discuss its universality. Calculations on a test set consisting of He, Be, Ne, Mg, H2, N2, and H2O yield μopt≈0.4a.u.. A similar analysis on other types of test systems such as actinide compounds is currently in progress. Using the value of 0.4a.u. for μ, encouraging results are obtained with the hybrid MCSCF-DFT method for the dissociation energies of H2, N2, and H2O, with both short-range local-density approximation and PBE-type functionals.
Compact wavelength detection system incorporating a guided-mode resonance filter
Authors: Ganesh Nikhil , Xiang Alan , Beltran Neill B. , Dobbs Dennis W. , Cunningham Brian T.
Published: February 2007

The authors demonstrate a compact system for the detection of the peak wavelength value emitted by a light source. The system is composed of only two components, a graded-wavelength guided-mode resonance filter placed before a charge-coupled device sensor array. The filter provides a spatially resolved transmission minimum, the position of which is controlled by the wavelength of the incoming light. The sensor array collects the spatially resolved transmitted intensity and the wavelength is determined by recording the position of the transmission minimum along its length. Using this technique, wavelength changes as small as 0.011nm can be detected.
Three dimensional controlled assembly of gold nanoparticles using a micromachined platform
Authors: Khanduja Nishant , Selvarasah Selvapraba , Chen Chia-Ling , Dokmeci Mehmet R. , Xiong Xugang , Makaram Prashanth , Busnaina Ahmed
Published: February 2007

By using optical lithographic procedures, the authors present a micromachined platform for large scale three dimensional (3D) assembly of gold nanoparticles with diameters of ∼50nm. The gold nanoparticles are formed into 3D low resistance bridges (two terminal resistance of ∼40Ω) interconnecting the two microelectrodes using ac dielectrophoresis. The thickness of the parylene interlevel dielectric can be adjusted to vary the height of the 3D platform for meeting different application requirements. This research represents a step towards realizing high density, three dimensional structures and devices for applications such as nanosensors, vertical integration of nanosystems, and characterization of nanomaterials.
Temperature dependence of the near-wall oscillation of microcantilevers submerged in liquid environment
Authors: Kim S. , Kihm K. D.
Published: February 2007

This letter presents theoretical and experimental investigations of the temperature effects (30–70°C) on the frequency responses of three different microcantilevers [thickness (h)/length (L)2=34.7,141,275m−1] near a solid surface in aqueous liquid. The peak resonance response frequency shifts in the near-wall region are dominated by the temperature effects associated with the pronounced viscous dissipative effect of liquid. A relatively short and thick cantilever with a large value of h∕L2 demonstrates higher thermal sensitivity Δf∕ΔT in the near-wall region.
Embedment of ZnO nanoparticles in SiO2 by ion implantation and low-temperature oxidation
Authors: Amekura H. , Umeda N. , Boldyryeva H. , Kishimoto N. , Buchal Ch. , Mantl S.
Published: February 2007

Samples of silica glass (SiO2) implanted with 60keV Zn ions to a fluence of 1.0×1017ions∕cm2 were annealed in oxygen gas to form ZnO nanoparticles (NPs). Although the ZnO NPs were formed mainly on the SiO2 surface after oxidation at 700°C for 1h, they were formed inside the SiO2 substrate after lower temperature and long-duration oxidation at 500°C for ∼70h, i.e., the embedment of ZnO NPs in SiO2 was attained. The embedded NPs show a slightly stronger exciton peak and much weaker defect luminescence than the NPs formed on the surface.
Electric-field-assisted bipolar charge generation from internal charge separation zone composed of doped organic bilayer
Authors: Terai Masaya , Tsutsui Tetsuo
Published: February 2007

For studying the mechanism of electric-field-assisted bipolar charges spouting from an internal charge separation (ICS) zone, three different categories of organic thin-film devices, which contain p-n heterojunction bilayer of tetrafluorotetracyanoquinodimethane-doped N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine and Mg-doped tris(8-quinolinolato)aluminum(III) for the ICS zone, have been fabricated. The bipolar charge separation mechanism in p- and n-doped organic bilayer system was explained in terms of the charge generation-recombination mechanism used in traditional inorganic p-n homojunction diodes.
Electrical properties of V-doped Bi3.15Nd0.85Ti3O12 thin films with different contents
Authors: Ye Z. , Tang M. H. , Zhou Y. C. , Zheng X. J. , Cheng C. P. , Hu Z. S. , Hu H. P.
Published: February 2007

Thin films of Nd3+-∕V5+-cosubstituted bismuth titanate, (Bi3.15Nd0.85)(Ti3−xVx)O12 (BNTV), were fabricated by chemical solution deposition technique. For different vanadium contents (x=0.03, 0.06, and 0.09), the crystallized phase and electrical properties of the films were investigated using x-ray diffraction, polarization hysteresis loops, leakage current-voltage, and capacitance butterfly loops. The authors found that increasing vanadium content leads to the decrease of coercive field and the increase of capacitance. The film of vanadium content x=0.09 exhibits fatigue-free and excellent leakage current characteristics with I=5.99×10−9A at applied voltage of 3V, which is much lower than that of Bi3.15Nd0.85Ti3O12 thin film [X. S. Gao and J. Wang, Thin Solid Films 515, 1683 (2006)]. The frequency dependence of the remanent polarization for the BNTV thin film was discussed.
Optically stimulated picosecond field emission pulses from gated p-silicon field emitter arrays
Authors: Chiang Chin-Jen , Liu Kendrick X. , Heritage Jonathan P.
Published: February 2007

Ultrashort current pulses of 130ps in duration were induced in an anode circuit from a gated p-type silicon field emitter array when excited by optical pulses of 110fs pulse width at 780nm wavelength. The speed of the photoresponse was limited by drift transient time spread through the depletion layer below the field emitter array (FEA) and not by gate capacitance. This result identifies the geometric origin of both drift limited and diffusion limited responses and demonstrates that a properly designed optically modulated gated FEA is a promising cold photocathode for the application of next generation microwave vacuum electronic devices.
NF-κB activation by the Toll-IL-1 receptor domain protein MyD88 adapter-like is regulated by caspase-1
Authors: Miggin Sinead M. , Pålsson-McDermott Eva , Dunne Aisling , Jefferies Caroline , Pinteaux Emmanuel , Banahan Kathy , Murphy Caroline , Moynagh Paul , Yamamoto Masahiro , Akira Shizuo , Rothwell Nancy , Golenbock Douglas , Fitzgerald Katherine A. , O'Neill Luke A. J.
Published: February 2007

Toll-like receptors (TLRs)-2 and -4 are important proteins in innate immunity, recognizing microbial products and eliciting host defense responses. Both use the adapter proteins MyD88 and MyD88 adapter-like (Mal) to activate signaling pathways. Here we report that Mal but not MyD88 interacts with caspase-1, the enzyme that processes the precursors of the proinflammatory cytokines IL-1β and IL-18. The interaction was found in a yeast two-hybrid screen and was confirmed by reciprocal GST pull-downs and coimmunoprecipitation of endogenous proteins. We were unable to implicate Mal in regulating caspase-1 activation. However, we found that Mal was cleaved by caspase-1 and that inhibition of caspase-1 activity blocked TLR2- and TLR4-mediated NF-κB and p38 MAP kinase activation but not IL-1 or TLR7 signaling, which are Mal independent. These responses, and the induction of TNF, were also attenuated in caspase-1-deficient cells. Finally, unlike wild-type Mal, a mutant Mal, which was not cleaved by caspase-1, was unable to signal and acted as a dominant negative inhibitor of TLR2 and TLR4 signaling. Our study therefore reveals a role for caspase-1 in the regulation of TLR2 and TLR4 signaling pathways via an effect on Mal. This functional interaction reveals an important aspect of the coordination between TLRs and caspase-1 during the innate response to pathogens.
Fusicoccins are biosynthesized by an unusual chimera diterpene synthase in fungi
Authors: Toyomasu Tomonobu , Tsukahara Mai , Kaneko Akane , Niida Rie , Mitsuhashi Wataru , Dairi Tohru , Kato Nobuo , Sassa Takeshi
Published: February 2007

Fusicoccins are a class of diterpene glucosides produced by the plant-pathogenic fungus
Phomopsis amygdali
. As modulators of 14-3-3 proteins, fusicoccins function as potent activators of plasma membrane H
+
-ATPase in plants and also exhibit unique biological activity in animal cells. Despite their well studied biological activities, no genes encoding fusicoccin biosynthetic enzymes have been identified. Cyclic diterpenes are commonly synthesized via cyclization of a C
20
precursor, geranylgeranyl diphosphate (GGDP), which is produced through condensation of the universal C
5
isoprene units dimethylallyl diphosphate and isopentenyl diphosphate by prenyltransferases. We found that (+)-fusicocca-2,10 (14)-diene, a tricyclic hydrocarbon precursor for fusicoccins, is biosynthesized from the C
5
isoprene units by an unusual multifunctional enzyme,
P. amygdali
fusicoccadiene synthase (PaFS), which shows both prenyltransferase and terpene cyclase activities. The functional analysis of truncated mutants and site-directed mutagenesis demonstrated that PaFS consists of two domains: a terpene cyclase domain at the N terminus and a prenyltransferase domain at the C terminus. These findings suggest that fusicoccadiene can be produced efficiently in the fungus by using the C
5
precursors, irrespective of GGDP availability. In fact, heterologous expression of PaFS alone resulted in the accumulation of fusicocca-2,10 (14)-diene in
Escherichia coli
cells, whereas no product was detected in
E. coli
cells expressing
Gibberella fujikuroi ent
-kaurene synthase, another fungal diterpene cyclase that also uses GGDP as a substrate but does not contain a prenyltransferase domain. Genome walking suggested that fusicoccin biosynthetic enzymes are encoded as a gene cluster near the PaFS gene.
Point mutations in TOR confer Rheb-independent growth in fission yeast and nutrient-independent mammalian TOR signaling in mammalian cells
Authors: Urano Jun , Sato Tatsuhiro , Matsuo Tomohiko , Otsubo Yoko , Yamamoto Masayuki , Tamanoi Fuyuhiko
Published: February 2007

Rheb is a unique member of the Ras superfamily GTP-binding proteins. We as well as others previously have shown that Rheb is a critical component of the TSC/TOR signaling pathway. In fission yeast, Rheb is encoded by therhb1gene. Rhb1p is essential for growth and directly interacts with Tor2p. In this article, we report identification of 22 single amino acid changes in the Tor2 protein that enable growth in the absence of Rhb1p. These mutants also exhibit decreased mating efficiency. Interestingly, the mutations are located in the C-terminal half of the Tor2 protein, clustering mainly within the FAT and kinase domains. We noted some differences in the effect of a mutation in the FAT domain (L1310P) and in the kinase domain (E2221K) on growth and mating. Although the Tor2p mutations bypass Rhb1p's requirement for growth, they are incapable of suppressing Rhb1p's requirement for resistance to stress and toxic amino acids, pointing to multiple functions of Rhb1p. In mammalian systems, we find that mammalian target of rapamycin (mTOR) carrying analogous mutations (L1460P or E2419K), although sensitive to rapamycin, exhibits constitutive activation even when the cells are starved for nutrients. These mutations do not show significant difference in their ability to form complexes with Raptor, Rictor, or mLST8. Furthermore, we present evidence that mutant mTOR can complex with wild-type mTOR and that this heterodimer is active in nutrient-starved cells.
SseL, a
Salmonella
deubiquitinase required for macrophage killing and virulence
Authors: Rytkönen Anne , Poh John , Garmendia Junkal , Boyle Cliona , Thompson Arthur , Liu Mei , Freemont Paul , Hinton Jay C. D. , Holden David W.
Published: February 2007

Expression of the
Salmonella enterica
serovar Typhimurium pathogenicity island 2 (SPI-2) type III secretion system is controlled by the two-component regulatory system SsrA-SsrB. We used a transcriptomic approach to help define the SsrA-SsrB regulon. We identified a gene encoding an uncharacterized effector (SseL) whose translocation into host cells depends on the SPI-2 secretion system. SseL has similarities to cysteine proteases with deubiquitinating activity. A GST-SseL fusion protein specifically hydrolyzed mono- and polyubiquitin substrates
in vitro
with a preference for K63-linked ubiquitin chains. Ubiquitin-modified proteins accumulated in macrophages infected with
Salmonella sseL
mutant strains but to a lesser extent when infected with bacteria expressing active protein, demonstrating that SseL functions as a deubiquitinase
in vivo. Salmonella sseL
mutant strains did not show a replication defect or induce altered levels of cytokine production upon infection of macrophages but were defective for a delayed cytotoxic effect and were attenuated for virulence in mice.
c-Myc-mediated genomic instability proceeds via a megakaryocytic endomitosis pathway involving Gp1bα
Authors: Li Youjun , Lu Jie , Prochownik Edward V.
Published: February 2007

Genomic instability (GI) is essential for the initiation and evolution of many cancers and often precedes frank neoplastic conversion. Although GI can occur at several levels, the most conspicuous examples involve gains or losses of entire chromosomes (aneuploidy), the antecedent of which may be whole genome duplication (tetraploidy). Through largely undefined mechanisms, the c-Myc oncoprotein and its downstream target, MTMC1, promote tetraploidy and other forms of GI. In myeloid cells, c-Myc and MTMC1 also regulate a common, small subset of c-Myc target genes including
GP1B
α, which encodes a subunit of the von Willebrand's factor receptor complex that mediates platelet adhesion and aggregation. Gp1bα also participates in megakaryocyte endomitosis, a form of controlled and precise whole-genome amplification. In this article, we show that both c-Myc and MTMC1 strongly up-regulate Gp1bα concurrent with their promotion of tetraploidy. shRNA-mediated inhibition of Gp1bα prevents tetraploidy by both c-Myc and MTMC1, whereas Gp1bα overexpression alone is sufficient to induce tetraploidy in established and primary cells. Once acquired, tetraploidy persists in most cases examined. Our results indicate that chromosome-level GI, induced by c-Myc overexpression, proceeds by means of the sequential up-regulation of MTMC1 and Gp1bα and further suggest that the pathways leading to megakaryocytic endomitosis and c-Myc-induced tetraploidy are mechanistically linked by their reliance on Gp1bα.
Cellular scaling rules for primate brains
Authors: Herculano-Houzel Suzana , Collins Christine E. , Wong Peiyan , Kaas Jon H.
Published: February 2007

Primates are usually found to have richer behavioral repertoires and better cognitive abilities than rodents of similar brain size. This finding raises the possibility that primate brains differ from rodent brains in their cellular composition. Here we examine the cellular scaling rules for primate brains and show that brain size increases approximately isometrically as a function of cell numbers, such that an 11× larger brain is built with 10× more neurons and ≈12× more nonneuronal cells of relatively constant average size. This isometric function is in contrast to rodent brains, which increase faster in size than in numbers of neurons. As a consequence of the linear cellular scaling rules, primate brains have a larger number of neurons than rodent brains of similar size, presumably endowing them with greater computational power and cognitive abilities.