bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring the Interaction of Albumin with a Paclitaxel‐Polymer Conjugate: Complex with Warfarin as Local Probe
Authors: Wunderlich Stefan , Zähres Manfred , Jo Byung‐Wook , Hess Michael
Published: November 2007

Summary: We have used warfarin as a local probe to investigate the orientation of paclitaxel and water soluble polymer conjugates of paxlitaxel in albumin. The relative orientation of warfarin and paclitaxel in a 1:1 complex in solution was investigated by 1H‐NMR‐spektroskopy (NOESY) and the results are used for the interpretation of the steric situation of paclitaxel respectively the polymer conjugate in albumin.
Mesoporous Silica Applications
Authors: Giraldo L. F. , López B. L. , Pérez L. , Urrego S. , Sierra L. , Mesa M.
Published: November 2007

Summary: The mesoporous silica have been considered fascinating materials for many techonological applications due to their porous and morphological characteristics. This review focuses on their use as stationary phases for liquid chromatography, supports for immobilizing biomolecules, catalysts, agent for polymer reinforcement and hard templates for the preparation of mesoporous carbons.
Stress Cracking and Photodegradation: The Combination of Two Major Causes of HIPS Failure
Authors: Timóteo G.A.V. , Fechine G.J.M. , Rabello M.S.
Published: November 2007

Summary: This work investigates the effects of photodegradation on the stress cracking resistance of high impact polystyrene (HIPS). Injection moulded samples were exposed to the ultraviolet light for various times in the laboratory prior to solvent contact. The bars were then stressed with several different loads in a tensile testing machine under the presence of several types of alcohols (mostly butanol). During this period, the stress relaxation was monitored and, after unloading, the ultimate properties were evaluated. Complementary tests were done by size exclusion chromatography, and scanning electron microscopy. The results indicated that both photodegradation and butanol causes significant modification in HIPS properties, with reduction in mechanical properties. The previously degraded samples showed a higher level of stress relaxation and a greater loss in tensile strength in comparison to the undegraded ones. The synergistic action of photodegradation and stress cracking in polystyrene may be a consequence of the chemical changes caused by oxidation and the reduction in molecular sizes.
Effect of Hibiscus anthocyanins‐rich extract induces apoptosis of proliferating smooth muscle cell via activation of P38 MAPK and p53 pathway
Authors: Lo Chia‐Wen , Huang Hui‐Pei , Lin Hui‐Mei , Chien Cheng‐Ting , Wang Chau‐Jong
Published: November 2007

Hibiscus sabdariffa L. (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in Sudan and in eastern Taiwan. It has been reported to contain a number of protocatechuic acid and anthocyanins. In vitro experimental studies have shown that anthocyanins administration of the extract produces anti‐inflammation and chemoprevention effects. In spite of the wide use of Hibiscus sabdariffa L. in folk medicine for treating various diseases, our previous study indicated a potency of Hibiscus sabdariffa extract (HSE) in anti‐atherosclerosis. The mechanisms of anthocyanins administration of the extract produce from Hibiscus sabdariffa L. to attenuate atherosclerosis were not clarified. In this study, we found that Hibiscus anthocyanins (HAs) could inhibit the serum‐stimulated proliferation of smooth muscle cell (SMC) and result in cell apoptosis. The HAs inducing cell apoptosis was dose dependent. We further used SB203580 (p38 inhibitor) to block cellular apoptosis and evaluate its effect on the HAs‐inducing SMC death via some apoptosis criteria including DNA fragmentation and flow cytometry. We suggested that the mechanisms of the inhibitory effect of HAs on atherosclerosis could be via inhibiting the proliferation of SMC. HAs induces apoptosis via (i) activating p38 MAP kinase that subsequently phosphorylates target protein c‐Jun and transduces the signal to further activate the apoptotic protein cascades that contain Fas‐mediated signaling (Fas/caspase‐8 signaling module) and (ii) activating p53 and inducing bax expression. As an outcome of the events, cytochrome c releases from the mitochondria, leading to cell apoptosis. In these experiments, HAs showed strong potential to induce SMC cell apoptosis via p38 and p53 pathway. In consequence, the rate of atherosclerotic formation is slowed down, and the progress is suppressed.
Comparison of ODE methods for laminar reacting gas flow simulations
Authors: van Veldhuizen S. , Vuik C. , Kleijn C.R.
Published: November 2007

Two‐dimensional transient simulations are presented of the transport phenomena and multispecies, multireaction chemistry in chemical vapor deposition (CVD). The transient simulations are run until steady state, such that the steady state can be validated against the steady state solutions from literature. We compare various time integration methods in terms of efficiency and robustness. Besides stability, which is important due to the stiffness of the problem, preservation of non‐negativity is crucial. It appears that this latter condition on a time integration method is much more restrictive toward the time step size than stability. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Very low surface recombination velocity of crystalline silicon passivated by phosphorus‐doped a‐SicxNy:H(n) alloys
Authors: Ferre R. , Orpella A. , Munoz D. , Martín I. , Recart F. , Voz C. , Puigdollers J. , Cabarrocas P. Roca i , Alcubilla R.
Published: November 2007

Hydrogenated and phosphorus‐doped amorphous silicon carbonitride films (a‐SiCxNy:H(n)) were deposited by plasma‐enhanced chemical vapor deposition (PECVD) on crystalline silicon surface in order to explore surface passivation properties. Very silicon‐rich films yielded effective surface recombination velocities at 1 sun‐illumination as low as 3 cm s−1 and 2 cm s−1 on 1 Ω cm p‐ and n‐type crystalline silicon substrates, respectively. In order to use them as anti‐reflection coating, we increased alternatively either the carbon or nitrogen content of these films. Also, a combination of passivation and antireflective films was analyzed. Finally, we explored the passivation stability under high‐temperature steps. Copyright © 2007 John Wiley & Sons, Ltd.
The Effect of Grinding on the Ground Material Flowability
Authors: Grant Evgeny , Kalman Haim , Averbuh Moshe
Published: November 2007

In this paper, attempts have been made for the first time, to experimentally evaluate the transformation, decrease and dissipation of the energy consumed during grinding by measuring the physical, chemical and mechanical properties of the ground material. By using a standard shear tester (Jenike shear cell) the unconfined yield strength and major consolidation stress of the ground material were measured immediately and after a period of storage. Also the solubility rate (ground material in water) of the same materials was defined simultaneously by measuring the electrical conductivity. The new experimental results aid the understanding of the behavior of ground material and may help provide better engineering tools for industrial design. A clear correlation has been found between solubility and flowability. Therefore, the flowability variations can be explained in the same way as the solubility.
Dynamics of Multiple Drive Belt Conveyor Systems
Authors: Nuttall Ashley J. G. , Lodewijks Gabriël
Published: November 2007

This paper investigates the dynamic starting behavior of long multiple drive belt conveyors. By simulating a speed controlled start procedure with a dynamic model, a comparison is made between the starting behavior of a single and a multiple drive layout, with no load on the belt. These simulations are also compared with simulations of a multiple drive layout that is configured for a loaded belt. These results show that a link can be established between the dynamic behavior of the belt sections in a multiple drive belt conveyor and a single driven conveyor system.
Analysis of Dry Bulk Terminals: Chances for Exploration
Authors: Schott Dingena L. , Lodewijks Gabriël
Published: November 2007

Over the last ten years, global economic developments have had an increasing influence on supply and demand trend in the dry bulk market. This increase has impacted on the shipping, dry cargo handling, bulk terminal operations and transportation industries. As a result the capacity of bulk handling terminals had to be increased, where on the other hand discussions about environmental regulations and pollution increase.

The objective of this paper is to point out several issues to be solved in the near future. It results in an overview and analysis of differences and similarities of the facilities for the handling, storage, and processing of the bulk material.

The analysis will be used to set up research projects at the department of Marine and Transport Technology of Delft University of Technology to further investigate the chances and challenges on improving equipment for the storage and transportation of particulate solids as well as their logistics.
Effects of Cyclic Loading and Various Test Conditions in an Uniaxial Tester
Authors: Nysaeter Trude O. , Enstad Gisle G.
Published: November 2007

The effect of cyclic loading during consolidation in an uniaxial tester is investigated. The effect seems to be a reduction of the compressive strength of BCR limestone powder, except for consolidation stresses close to the stress level of the cyclic loading. The larger the consolidation stress level is, the more the compressive strength is reduced compared to standard consolidation without cycling. The velocity of the piston under consolidation, as well as the number of cycles and at what stress level the cycling took place, also affect the compressive strength.
Bulk Solid Interactions in Belt Conveying Systems: Transition Zone
Authors: Ilic Dusan D. , Wheeler Craig A. , Roberts Alan W.
Published: November 2007

In belt conveying systems, bulk solid material immediately prior to discharge moves from a troughed profile on the last idler set to a flat profile at the head pulley. How the bulk solid material behaves in this zone is a function of the material properties of the bulk solid and the transition time, which in turn depends on the transition length and belt speed. The accurate determination of the discharge profile is essential for effective transfer chute design.

This paper describes an experimental test rig which aims to simulate the motion of the bulk solid material on the conveyor belt during transportation and throughout the transition zone. Results are presented and compared to existing theoretical approximations.
Investigations of Porosity Changes during Granular Silo Flow Using Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV)
Authors: Niedostatkiewicz Maciej , Tejchman Jacek
Published: November 2007

The paper presents results of measurements of porosity changes in sand during granular flow in model silos using two different non‐invasive methods, i.e., Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV). The experiments in model silos are carried out with different initial unit weights of sand and silo wall roughness. Advantages and disadvantages of both methods are outlined.
The Pattern of Fine Comminution Products
Authors: Gente Vincenzo , Giancontieri Vincenzo , La Marca Floriana , Massacci Paolo
Published: November 2007

A new approach is suggested for the purposes of obtaining a proper character‐distribution pattern of a particle set. Different methods of modeling the series of size characterization data are examined. Fourier analysis is applied to detail new parameters (features) for enhancing the differences between size distributions under different comminution operating conditions. Size distribution relating to a set of comminuted particles is processed as a signal (size vector) to extract the feature set. The results are compared to provide an insight into the effectiveness of each data analysis method. In particular, some of the Fourier series sine‐coefficient values, relating to the size vector of a particle set, can represent the post‐comminution size‐distribution pattern. For example, size distribution following cryogenic comminution under different temperature conditions can be modeled using a second‐order equation function of four selected Fourier analysis sine coefficients.
A Rotational Tester for the Characterization of Aerated Shear Flow of Powders
Authors: Barletta Diego , Donsì Giorgio , Ferrari Giovanna , Poletto Massimo
Published: November 2007

A rotational shear tester for aerated shear flow was built on the work bench of a Peschl shear tester. Measurements with a conventional incipient shear test procedure and a purposely developed dynamic shear test procedure were carried out on two different cohesive powders: a magnesium carbonate powder and a silica powder. Permeability measurements were carried out in the dynamic shear test experiments to assess the effect of shearing. The results obtained at low powder consolidation levels confirm literature findings at higher degrees of consolidation. In particular, aeration does not appear to have the ability to change the rheological properties of the powder. Shear test results at different aeration intensities are the same if the stress changes induced by aeration on the shear plane are correctly accounted for. Permeability measurements were compared following uniaxial powder compaction and shearing powder compaction experiments. The internal powder structure of the magnesium carbonate powder appeared to change between experiments. Further investigations are required to determine if this change also occurs with the silica powder.
Investigation of Heat and Moisture Effects in Silos Containing Agricultural Bulk Solids
Authors: Prusiel Jolanta A. , Lapko Andrzej
Published: November 2007

This paper presents the results of experimental and theoretical analyses concerning thermal and moisture effects on a model cylindrical silo. The experimental studies were conducted on a thin‐walled cylindrical silo model bin of diameter 800 mm and total depth 2500 mm, filled with mustard seeds. For the purposes of modeling thermal changes in the particles, the external surface of the model silo bin was exposed to heating by electrical wires and then allowed to cool naturally, before filling the bin. The experimental results were compared with the numerical simulation results performed on the basis of equations of coupled heat and moisture transfer in the particulate solid and concrete wall, with the use of experimentally determined bulk solid properties.
2D‐Fractal Based Algorithms for Fine and Ultrafine Particulate Solids Systems Characterization
Authors: Bonifazi Giuseppe
Published: November 2007

Fractal geometry concerns the study of non‐Euclidean geometrical figures generated by a recursive sequence of mathematical operations. The proposed 2D‐fractal approach was applied to characterise the image structure and texture generated by fine and ultrafine particles when impacting on a flat surface. The work was developed with reference to particles usually produced in the ornamental stone sector during the different working phases carried out in dry conditions. Specific milling actions have been performed at a laboratoty scale on different ornamental stone products, in order to generate different particle populations to utilize in the study. The aim of the work was to develop a simple, reliable and low cost analytical set of procedures with the ability to establish correlations between particles detected by fractal characteristics and their classical attributes, e.g., i) size class distribution, ii) shape, iii) composition, etc. Such a logic should constitute the core of a control engine with the ability to optimize dust capture abatement strategies, according to produced dusts characteristics.
Effect of the Mineral Filler on the Surface Properties of Co‐Ground Polymeric Composites
Authors: Zapata‐Massot Céline , Le Bolay Nadine
Published: November 2007

This study presents results on the influence of the nature of the filler on the surface properties of polymeric composites produced by co‐grinding in a tumbling ball mill. The polymer used in the study was poly(vinyl acetate) which is a model material, while two mineral fillers were tested, i.e., calcium carbonate and silica. The variations of the surface properties of the separately ground and co‐ground materials were studied for different grinding times, using the sessile drop method, and the properties were compared to those of matrix‐filler blends. The different components of the surface energy were determined by Van Oss decomposition. Grinding generates a large change of the particle surface and especially of the Lewis acid‐base energy. These changes depend on the filler nature. In addition, particle agglomeration may be due to an electronic deficit at the particle surface, which is immediately replaced by another particle also possessing an electronic deficit.
Generalization of cluster treatment of characteristic roots for robust stability of multiple time‐delayed systems
Authors: Sipahi Rifat , Fazelinia Hassan , Olgac Nejat
Published: November 2007

A new perspective is presented for studying the stability robustness of nth order systems with p rationally independent delays. It deploys a holographic mapping procedure over the delay space into a new coordinate system in order to achieve the objective. This mapping collapses the entire set of potential stability switching points on a manageably small number of hypersurfaces, which are explicitly defined in the new domain. This property considerably alleviates the problem, which is otherwise infinite dimensional, and therefore notoriously complex to handle. We further declare some unrecognized features of these switching hypersurfaces, that they are (a) encapsulated within a higher‐dimensional cube with edges of length 2π, which we name the ‘building block’, and (b) the ‘offspring’ of this building block, which represent the secondary stability switchings, appear within the adjacent and identical building blocks (cubes) stacked up next to each other. The final outlook is an exclusive representation of stability for this general class of systems at any arbitrary point in the delay space. Two example case studies are also provided, which are not possible to analyze using any other methodology known to the authors. Copyright © 2007 John Wiley & Sons, Ltd.
Stable, High‐Efficiency Ionic‐Liquid‐Based Mesoscopic Dye‐Sensitized Solar Cells
Authors: Kuang Daibin , Klein Cedric , Zhang Zhipan , Ito Seigo , Moser Jacques‐E. , Zakeeruddin Shaik. M. , Grätzel Michael
Published: November 2007

Efficient and stable mesoscopic dye‐sensitized solar cells (DSCs) introducing a low‐viscosity binary ionic liquid (1‐propyl‐3‐methyl‐imidazolium iodide (PMII) and 1‐ethyl‐3‐methyl‐imidazolium tetracyanoborate (EMIB(CN)4)) electrolyte in combination with a new high‐molar‐extinction‐coefficient ruthenium complex, Ru(2,2′‐bipyridine‐4,4′‐dicarboxylic acid)(4,4′‐bis(2‐(4‐tert‐butyloxy ‐phenyl)ethenyl) −2,2′‐bipyridine) (NCS)2, are demonstrated. The dependence of photovoltaic performance, charge transport and electron lifetime on the composition of the binary ionic‐liquid electrolyte with different ratios of PMII/EMIB(CN)4 were investigated by electrochemical impedance and photovoltage transient techniques. A photovoltaic conversion efficiency of 7.6 % was obtained under simulated full sunlight illumination, which is a record for solvent‐free DSCs. These devices exhibit excellent stability at 80 °C in the dark or under visible‐light soaking at 60 °C during 1000 h of accelerated tests.
Simplified shallow water flow equations and their potential use in bottom profile optimization
Authors: Wiker N. , Klarbring A. , Borrvall T.
Published: November 2007

From the numerical examples it is concluded that natural–like designs can be created for proper choices of parameter values. However, presently the model is not physically validated and its exact domain of application is not yet known.
Chemical disulfide mapping identifies an inhibitor cystine knot in the agouti signaling protein
Authors: Yu Bin , Millhauser Glenn L.
Published: November 2007

The agouti signaling protein (ASIP) and its homolog, the agouti‐related protein (AgRP), act as inverse agonists that control, respectively, pigmentation and metabolic function in mammals. NMR investigations find that the C‐terminal domains of these proteins adopt a fold consistent with an inhibitor cystine knot (ICK), previously identified in invertebrate toxins. Although these structural studies suggest that ASIP and AgRP define a new mammalian protein fold class, the results with ASIP are inconclusive. Here, we apply direct chemical mapping to determine the complete set of disulfide linkages in ASIP. The results demonstrate unequivocally that ASIP adopts the ICK fold and thereby supports a recent evolution structure function analysis, which proposes that ASIP and AgRP arose from a common antagonist ligand.
Identification of the flavoprotein of succinate dehydrogenase and aconitase as in vitro mitochondrial substrates of Fgr tyrosine kinase
Authors: Salvi Mauro , Morrice Nick A. , Brunati Anna Maria , Toninello Antonio
Published: November 2007

Here, we provide evidence that the flavoprotein of succinate dehydrogenase and aconitase are “in vitro” substrates of Fgr tyrosine kinase. Fgr phosphorylates flavoprotein of succinate dehydrogenase at Y535 and Y596 and aconitase at Y71, Y544 and Y665. The significance of these findings is discussed.
ALLOCATING THE RISK OF ERROR:
Authors: Nance Dale A.
Published: November 2007

Review of Foundations of Evidence Law, by Alex Stein (Oxford University Press, 2005)
THE FIRST VIRTUE OF THE LAW COURTS AND THE FIRST VIRTUE OF THE LAW
Authors: Sheinman Hanoch
Published: November 2007

Justice, you might think, is the first virtue of the law. After all, we call our judges justices, the administration of law the administration of justice, and the government's legal department the Justice Department. We should reject thisPriority of Justice for the Lawin favor of the more moderatePriority of Justice for the Courts, the view that justice is the first virtue of the law courts. Under its comparative conception, justice is distinguishable by its concern with the relative positions of subjects. I claim that legal duties divide into primary and secondary, that primary legal duties are not essentially comparative, and that this impugns the Priority ofComparativeJustice for the Law. Still, the bipolar structure of litigation appears to suggest that comparative justice is the first virtue of thecourts. I explain why that is not so. I then introduce a desert-based conception of justice I dubrequitative justice. I argue that the Priority of Justice for the Law cannot draw succor from this conception of justice because primary legal duties are no more requitative than they are comparative. However, the special affinity between law courts and secondary legal duties suggests that requitative justice is the first virtue of the courts. Finally, I concede that the Priority of Justice for the Courts gives us reason to accept the Priority of Justice for the Law after all, if we accept the commonPriority of Courts for the Law, the view that the courts are the first institution of the law. We should not do so, however.
A hierarchical optimization approach to watershed land use planning
Authors: Yeo In‐Young , Guldmann Jean‐Michel , Gordon Steven I.
Published: November 2007

A hierarchical optimization framework is developed to analyze spatially complex watersheds and to support spatial decision making for land management practices. A watershed is subdivided into smaller spatial units according to its hierarchy, and a three‐level optimization approach determines optimal land allocations at the subarea, catchment, and 30 m cell levels. A storm water runoff simulation model is used to generate peak discharge pseudo data, under different land use patterns. The results are inputs to regression analyses, and the functional relationships between peak discharges and land use variables are estimated as quadratic functions (r2> 0.90). These functions are used in the optimization models to allocate future land uses to minimize peak discharges at the watershed and subarea outlets. The integrated hydrological land use optimization (IHLUO) model is next used to allocate land uses at the cell level. The results are promising, with a 46% reduction of the peak discharge rate as compared to the rate generated by the current land use pattern. The results provide site‐specific guidelines for land use management and practices at a high spatial resolution (30 m). The proposed methodology is applied to the Old Woman Creek watershed, located in the southwestern basin of Lake Erie (Ohio).
Evaluating specific error characteristics of microwave‐derived cloud liquid water products
Authors: Greenwald Thomas J. , L'Ecuyer Tristan S. , Christopher Sundar A.
Published: November 2007

Methods are presented for assessing minimum errors and cloud inhomogeneity effects in cloud liquid water path (LWP) products derived from passive microwave satellite measurements. Using coincident visible/infrared satellite data, errors are isolated by identifying certain cloud conditions within the microwave sensor's field of view. Analysis of 3 weeks of global pixel‐level LWP data revealed that 70% of the systematic errors occurred between −0.011 and +0.025 kgm−2, with the mean random error being 0.013 kgm−2. For overcast clouds these systematic errors translate to a mean lower‐bound relative error of about +23%. A significant correlation of these products with near‐surface wind speed was also shown. The LWP products were found to depend on cloud fraction as well, suggesting the influence of beam filling errors. This approach shows promise in characterizing the minimum errors in LWP products needed for climate and remote sensing studies as well as future data assimilation applications.
Source mechanics for monochromatic icequakes produced during iceberg calving at Columbia Glacier, AK
Authors: O'Neel Shad , Pfeffer W. T.
Published: November 2007

Seismograms recorded during iceberg calving contain information pertaining to source processes during calving events. However, locally variable material properties may cause signal distortions, known as site and path effects, which must be eliminated prior to commenting on source mechanics. We applied the technique of horizontal/vertical spectral ratios to passive seismic data collected at Columbia Glacier, AK, and found no dominant site or path effects. Rather, monochromatic waveforms generated by calving appear to result from source processes. We hypothesize that a fluid‐filled crack source model offers a potential mechanism for observed seismograms produced by calving, and fracture‐processes preceding calving.
Vertical profiles in NO3 and N2O5 measured from an aircraft: Results from the NOAA P‐3 and surface platforms during the New England Air Quality Study 2004
Authors: Brown Steven S. , Dubé William P. , Osthoff Hans D. , Stutz Jochen , Ryerson Thomas B. , Wollny Adam G. , Brock Charles A. , Warneke Carsten , de Gouw Joost A. , Atlas Eliot , Neuman J. Andrew , Holloway John S. , Lerner Brian M. , Williams Eric J. , Kuster William C. , Goldan Paul D. , Angevine Wayne M. , Trainer Michael , Fehsenfeld Frederick C. , Ravishankara A. R.
Published: November 2007

The nocturnal nitrogen oxides, NO3 and N2O5, are important to the chemical transformation and transport of NOx, O3 and VOC. Their concentrations, sources and sinks are known to be vertically stratified in the nighttime atmosphere. In this paper, we report vertical profiles for NO3 and N2O5 measured from an aircraft (the NOAA P‐3) as part of the New England Air Quality Study in July and August 2004. The aircraft data are compared to surface measurements made in situ from a ship and by long‐path DOAS. Consistent with previous, vertically resolved studies of NO3 and N2O5, the aircraft measurements show that these species occur at larger concentrations and are longer lived aloft than they are at the surface. The array of in situ measurements available on the P‐3 allows for investigation of the mechanisms that give rise to the observed vertical gradients. Selected vertical profiles from this campaign illustrate the role of biogenic VOC, particularly isoprene and dimethyl sulfide, both within and above the nocturnal and/or marine boundary layer. Gradients in relative humidity and aerosol surface may also create a vertical gradient in the rate of N2O5 hydrolysis. Low‐altitude intercepts of power plant plumes showed strong vertical stratification, with plume depths of 80 m. The efficiency of N2O5 hydrolysis within these plumes was an important factor determining the low‐level NOx and O3 transport or loss at night. Averages of nocturnal O3, NO2, NO3 and N2O5 binned according to altitude were consistent with the trends from individual profiles. While production rates of NO3 peaked near the surface, lifetimes of NO3 and N2O5 were maximum aloft, particularly in the free troposphere. Variability in NO3 and N2O5 was large and exceeded that of NO2 or O3 because of inhomogeneous distribution of NOx emissions and NO3 and N2O5 sinks.
Visualizing the effects of antigen affinity on T‐dependent B‐cell differentiation
Authors: Brink Robert , Phan Tri Giang , Paus Didrik , Chan Tyani D
Published: November 2007

Burnet's original description of the clonal selection hypothesis of antibody production included many prescient predictions of how ‘lymphocytes carrying reactive sites’ for foreign antigens might respond during immune responses. Somatic mutation, plasma cell differentiation and transition into memory cells were all described as potential fates for the ‘variety of descendents’ derived from proliferative expansion of antigen‐reactive clones. After 50 years much is known about the molecular controls that drive these various processes. Comparatively little insight has been gained, however, into why particular daughter cells progress down one response pathway versus another. In this article, we briefly describe the evolution of the genetic technologies that now allow us to visualize the very processes predicted by Burnet. An in‐depth description of the recently developed SWHEL mouse model and its utility for tracking in vivo B‐cell responses to various forms of hen‐egg lysozyme (HEL) is also provided. Recent data obtained with this system indicate that antigen‐dependent variables play a critical role in regulating the differentiation of responding B cells into antibody‐secreting plasma cells.
Development of Molecular Biology at the University of Wisconsin, Madison
Authors: Halvorson Harlyn O.
Published: November 2007

Dramatic changes in the foundation of academic departments in our universities are uncommon. With the demonstration that DNA was the cellular source of genetic information, and that this information could be regulated, the field of molecular biology was born. Later, when scientists found that they could tinker with this information, the field matured. In an unusually rapid manner, molecular biology was integrated into the University of Wisconsin, Madison, in the late 1950s and early 1960s. This present article is a chronology of how it happened. What are the factors that made this transition possible in the University of Wisconsin? What lessons have we learned from this experience?
Spatial updating grand canonical Monte Carlo algorithms for fluid simulation: Generalization to continuous potentials and parallel implementation
Authors: O’Keeffe C. J. , Ren Ruichao , Orkoulas G.
Published: November 2007

Spatial updating grand canonical Monte Carlo algorithms are generalizations of random and sequential updating algorithms for lattice systems to continuum fluid models. The elementary steps, insertions or removals, are constructed by generating points in space either at random (random updating) or in a prescribed order (sequential updating). These algorithms have previously been developed only for systems of impenetrable spheres for which no particle overlap occurs. In this work, spatial updating grand canonical algorithms are generalized to continuous, soft-core potentials to account for overlapping configurations. Results on two- and three-dimensional Lennard–Jones fluids indicate that spatial updating grand canonical algorithms, both random and sequential, converge faster than standard grand canonical algorithms. Spatial algorithms based on sequential updating not only exhibit the fastest convergence but also are ideal for parallel implementation due to the absence of strict detailed balance and the nature of the updating that minimizes interprocessor communication. Parallel simulation results for three-dimensional Lennard–Jones fluids show a substantial reduction of simulation time for systems of moderate and large size. The efficiency improvement by parallel processing through domain decomposition is always in addition to the efficiency improvement by sequential updating.
Unsteady features on one-dimensional hydrogen-air detonations
Authors: Daimon Yu , Matsuo Akiko
Published: November 2007

The features of one-dimensional unsteady detonations are studied numerically using a hydrogen-air detailed chemical reaction model. A series of simulations are carried out while degree of overdrive, initial pressure, initial temperature, and equivalence ratio are varied. The oscillation modes and mechanisms of the one-dimensional detonations are discussed with reference to shock pressure histories and x-t diagrams of density distributions. As the degree of overdrive is reduced with a stoichiometric mixture of hydrogen-air at P0=0.421atm and T0=293K, a steady state appears, along with a high-frequency mode and a low-frequency mode. The oscillation mechanism of the high-frequency mode is the same as that of the regular regime of unsteady shock-induced combustion observed around a spherical projectile flying at hypersonic velocity in detonable gases. The degree of overdrive threshold between the steady and unsteady region increases monotonically with initial pressure and decreases monotonically with initial temperature. When the equivalence ratio is changed, the threshold has a minimum value around ϕ=1. We focus attention on a nondimensional effective activation energy, which is generally used for linear stability analysis. The oscillation mode depends highly on the nondimensional effective activation energy. The oscillation of the detonation front appears as the nondimensional effective activation energy goes past a threshold value of 5.2. Furthermore, we investigate the failed regime and possible reignition in this regime. In the failed regime, a detonation wave breaks up into a leading shock, a contact discontinuity, and a rarefaction wave. When the shock is weak, reignition time becomes very long. Therefore, the reignition after the failed regime is difficult to reproduce in the restricted computational domain. The reignition process in the failed regime is investigated by means of analysis consisting of integration along the point of intersection between a Rayleigh line for weak leading shock and a partially burnt Hugoniot curve. The reignition time increases dramatically with decreasing temperature behind the shock wave, when the gas condition goes past the second explosion limit. The second explosion limit is one of the characteristics of the hydrogen-air detailed chemical reaction model and does not exist in the one-step chemical reaction model. Lastly, the reignition time obtained by the analysis is compared with that obtained by the simulation results. The simulation results agree well with the analytical results.
Some effects on quantum systems due to the gravitational field of a cosmic string
Authors: Marques Geusa de A. , de Assis J. G. , Bezerra V. B.
Published: November 2007

We study the behavior of a nonrelativistic quantum particle interacting with different potentials in the background space-time generated by a cosmic string. We find the energy spectra for the quantum systems under consideration and discuss how they differ from their flat Minkowski space-time values.
Formation and optical properties of CdTe∕ZnTe nanostructures with different CdTe thicknesses grown on Si (100) substrates
Authors: Lee H. S. , Park H. L. , Lee I. , Kim T. W.
Published: November 2007

Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the formation and the optical properties of CdTe∕ZnTe nanostructures with various CdTe thicknesses grown on Si (100) substrates by using molecular beam epitaxy and atomic layer epitaxy. AFM images showed that uniform CdTe∕ZnTe quantum dots with a CdTe layer thickness of 2.5 ML (monolayer) were formed on Si (100) substrates. The excitonic peaks corresponding to transitions from the ground electronic subband to the ground heavy-hole band in the CdTe∕ZnTe nanostructures shifted to a lower energy with increasing thickness of the CdTe layer. The activation energies of the carriers confined in the CdTe∕ZnTe nanostructures grown on Si (100) substrates were obtained from the temperature-dependent PL spectra. The present observations can help improve understanding of the formation and the optical properties in CdTe∕ZnTe nanostructures with different CdTe thicknesses grown on Si (100) substrates.
Dynamics of ultrathin metal films on amorphous substrates under fast thermal processing
Authors: Favazza Christopher , Kalyanaraman Ramki , Sureshkumar Radhakrishna
Published: November 2007

A mathematical model is developed to analyze the growth/decay rate of surface perturbations of an ultrathin metal film on an amorphous substrate (SiO2). The formulation combines the approach of Mullins [W. W. Mullins, J. Appl. Phys. 30, 77 (1959)] for bulk surfaces, in which curvature-driven mass transport and surface deformation can occur by surface/volume diffusion and evaporation-condensation processes, with that of Spencer etal. [B. J. Spencer, P. W. Voorhees, and S. H. Davis, Phys. Rev. Lett. 67, 26 (1991)] to describe solid-state transport in thin films under epitaxial strain. Modifications of the Mullins model to account for thin-film boundary conditions result in qualitatively different dispersion relationships especially in the limit as kho≪1, where k is the wavenumber of the perturbation and ho is the unperturbed film height. The model is applied to study the relative rate of solid-state mass transport as compared to that of liquid phase dewetting in a thin film subjected to a fast thermal pulse. Specifically, we have recently shown that multiple cycles of nanosecond (ns) pulsed laser melting and resolidification of ultrathin metal films on amorphous substrates can lead to the formation of various types of spatially ordered nanostructures [J. Trice, D. Thomas, C. Favazza, R. Sureshkumar, and R. Kalyanaraman, Phys. Rev. B 75, 235439 (2007)]. The pattern formation has been attributed to the dewetting of the thin film by a hydrodynamic instability. In such experiments the film is in the solid state during a substantial fraction of each thermal cycle. However, results of a linear stability analysis based on the aforementioned model suggest that solid-state mass transport has a negligible effect on morphological changes of the surface. Further, a qualitative analysis of the effect of thermoelastic stress, induced by the rapid temperature changes in the film-substrate bilayer, suggests that stress relaxation does not appreciably contribute to surface deformation. Hence, surface deformation caused by liquid phase instabilities is rapidly quenched-in during the cooling phase. This deformed state is further evolved by subsequent laser pulses. These results have implications to developing accurate computer simulations of thin-film dewetting by energetic beams aimed at the manufacturing of optically active nanoscale materials for applications including information processing, optical devices, and solar energy harvesting.
Europeanising Advisory Expertise: The Role of ‘Independent, Objective, and Transparent’ Scientific Advice in Agri-Biotech Regulation
Authors: Levidow Les , Carr Susan
Published: November 2007

Since various crises concerning food safety in the European Union (EU), institutional reforms have been designed to regain public confidence in regulatory decisions and their expert basis. By Europeanising advisory expertise, the European Food Safety Authority (EFSA) was also intended to help harmonise ‘science-based regulation’ and thus facilitate EU decisions. In evaluating agri-biotech products during 2003 – 05, however, the EFSA procedure extended previous expert disagreements rather than overcome them. The EFSA was designed to demonstrate that expert advice would be ‘independent, objective, and transparent’; yet tensions arose between expert experience versus independence, between transparency versus objectivity, and between harmonisation versus precaution. These conflicts have been shaped by the dominant problem diagnosis, which favours a narrow expert consensus within a specific policy view. Alternative problem diagnoses suggest that expertise should instead be pluralised, so that norms and uncertainties become more explicit. Pressure for EU reform manifests tensions between the dominant and alternative problem diagnoses.
The Role of Universities in the Regional Innovation Systems of the North East of England and Scania, Sweden: Providing Missing Links?
Authors: Coenen Lars
Published: November 2007

The increased popularity of and attention paid to innovation-based regional growth and development has, among other things, raised the importance of universities in regional innovation systems (RIS). The triple-helix literature especially underscores the value of increased interaction and interdependence between universities, industry, and government in modern, knowledge-based, economies by acclaiming the rise of the entrepreneurial. The author provides a comparative analysis of the RIS problems in the North East in the United Kingdom and Scania in Sweden and the role of universities in regional innovation policies addressing these problems. The results of this comparison question a one-size-fits-all (entrepreneurial) model to harness university-based knowledge resources for regional development. Instead, it is shown that various constellations are possible dependent on the characteristics of the RIS problems.
The New Economic Geography of Old Industrial Regions: Universities as Global — Local Pipelines
Authors: Benneworth Paul , Hospers Gert-Jan
Published: November 2007

The knowledge economy appears to be problematic for old industrial regions, as lock-in and restructuring remove assets for innovation from their territories, as well as for the kinds of policy which can stimulate their economies. In this paper we explore whether universities can provide points of stability within which such locked-in regions can strengthen their innovation systems and attract external investment in knowledge capital. Using the case study of Twente in the eastern Netherlands, we explore whether universities can strengthen their regional innovation systems. We distinguish local networking from external-investment attraction to show that universities can become temporary venues for ‘local buzz’, building networks which become attractive to outside investors and promoting regional innovation. This suggests that an alternative approach to regional innovation policy, which we term ‘promoting smart hybridity’, may be useful in stimulating growth-based restructuring in such regions.
Intuitions of probabilities shape expectations about the future at 12 months and beyond
Authors: Téglás Ernő , Girotto Vittorio , Gonzalez Michel , Bonatti Luca L.
Published: November 2007

Rational agents should integrate probabilities in their predictions about uncertain future events. However, whether humans can do this, and if so, how this ability originates, are controversial issues. Here, we show that 12-month-olds have rational expectations about the future based on estimations of event possibilities, without the need of sampling past experiences. We also show that such natural expectations influence preschoolers' reaction times, while frequencies modify motor responses, but not overt judgments, only after 4 years of age. Our results suggest that at the onset of human decision processes the mind contains an intuition of elementary probability that cannot be reduced to the encountered frequency of events or elementary heuristics.
A T cell receptor associated with naturally occurring human tumor immunity
Authors: Santomasso Bianca D. , Roberts Wendy K. , Thomas Ashby , Williams Travis , Blachère Nathalie E. , Dudley Mark E. , Houghton Alan N. , Posner Jerome B. , Darnell Robert B.
Published: November 2007

The onconeural antigens appear to serve as tumor rejection antigens in the paraneoplastic neurologic disorders. Here, we used an unbiased peptide binding screen, followed by studies in HLA-A2.1 transgenic mice to identify naturally processed HLA-A2.1 restricted epitopes of the paraneoplastic cerebellar degeneration breast/ovarian cancer antigen cdr2. These mice were used to clone high-avidity cdr2-specific CD8+T cells that recognize human tumor cells presenting endogenously loaded MHC class I-cdr2 peptide. T cells with this specificity were detected in the peripheral blood of two HLA-A2.1+paraneoplastic cerebellar degeneration patients. We cloned T cell receptor (TCR) α and β genes from cdr2-specific T cells; electroporation of RNA encoding this TCR turned nonreactive donor T cells into efficient killers of human cdr2-expressing tumor cells. Cloned cdr2-specific TCR genes provide a clinically relevant means for immunologic targeting of human gynecologic cancers.
Development and regeneration of hair cells share common functional features
Authors: Levic Snezana , Nie Liping , Tuteja Dipika , Harvey Margaret , Sokolowski Bernd H. A. , Yamoah Ebenezer N.
Published: November 2007

The structural phenotype of neural connections in the auditory brainstem is sculpted by spontaneous and stimulus-induced neural activities during development. However, functional and molecular mechanisms of spontaneous action potentials (SAPs) in the developing cochlea are unknown. Additionally, it is unclear how regenerating hair cells establish their neural ranking in the constellation of neurons in the brainstem. We have demonstrated that a transient Ca
2+
current produced by the Ca
v
3.1 channel is expressed early in development to initiate spontaneous Ca
2+
spikes. Ca
v
1.3 currents, typical of mature hair cells, appeared later in development. Moreover, there is a surprising disappearance of the Ca
v
3.1 current that coincides with the attenuation of the transient Ca
2+
current as the electrical properties of hair cells transition to the mature phenotype. Remarkably, this process is recapitulated during hair-cell regeneration, suggesting that the transient expression of Ca
v
3.1 and the ensuing SAPs are signatures of hair cell development and regeneration.