bluuebunny/crossref_metadata_2025 huggingface dataset:
Diabetes and Risk of Non-Hodgkin's Lymphoma
Authors: Mitri Joanna , Castillo Jorge , Pittas Anastassios G.
Published: November 2008

OBJECTIVE—To examine the epidemiologic association between diabetes and risk of non-Hodgkin's lymphoma (NHL).

RESEARCH DESIGN AND METHODS—We searched MEDLINE for observational studies on the association between diabetes and NHL in adults using the keywords “diabetes” and “lymphoma.” Prospective cohort studies that reported relative risks or standardized incidence ratios and case-control studies that reported odds ratios with 95% CIs were included. A random-effects model was used to combine results from the individual studies.

RESULTS—A total of 15 manuscripts (reporting data from 5 prospective cohort and 11 case-control studies) met the inclusion criteria. Combining data from all studies, the risk ratio (RR) of developing NHL in patients with diabetes was 1.19 (95% CI 1.04–1.35). Based on prospective studies, patients with diabetes had an RR of developing NHL of 1.41 (1.07–1.88), without heterogeneity among studies (I2 = 34.3%; P > 0.10). Based on case-control studies, patients with diabetes had an RR of 1.12 (95% CI 0.95–1.31) of developing NHL compared with people without diabetes, with some heterogeneity among studies (I2 = 36.28%; P = 0.09).

CONCLUSIONS—Diabetes is associated with a moderately increased risk of NHL, which is consistent with other reported associations between diabetes and malignancies. Future studies should focus on elucidating potential pathophysiologic links between diabetes and NHL.
Enhancing In-Car Navigation Systems with Personal Experience
Authors: Bederson Benjamin B. , Clamage Aaron , Plaisant Catherine
Published: November 2008

Computers are extremely powerful for data processing but less adept at handling problems that involve subjective reasoning. People, on the other hand, are good at such tasks. A framework is presented for adding subjective human experience to in-car navigation systems. People often rely on personal experience when planning trips, choosing the route that is fastest, prettiest, or recommended by a friend. A set of methods was developed to help people record personal driving history, add textual annotations describing subjective experiences, and share data with friends and family or even the broader community. Users can then learn from personal data or harness the multiplicity of individual experiences to enjoy new routes. This approach can be used in conjunction with traditional in-car navigation systems.
New Active Traffic Management Approach for Metropolitan Freeway Networks
Authors: DeCorla-Souza Patrick
Published: November 2008

A new active traffic management approach that could be implemented in the near term is illustrated for two of the most congested U.S. metropolitan areas using a sketch-planning tool. The approach involves converting existing freeways into premium service, free-flowing highways that provide fast, frequent, and inexpensive express bus service, while charging all private vehicles a variable toll, except for authorized buses and certified ridesharing vehicles. Public concerns about having a free travel choice are addressed by creating a toll-free bypass lane in advance of toll gantries placed across the freeway where those not wanting to pay for premium congestion-free services may wait in a queue. The monetary value of the wait time in the queue would be in equilibrium with the toll rate in effect. The toll would vary by level of demand and would be set high enough to guarantee that excessive demand would not cause a breakdown of traffic flow. Implementing the concept in Los Angeles, California, could reduce peak-period congestion delay by up to 33 h per traveler annually and save each traveler up to 83 gal of fuel annually. New toll revenues would be more than adequate to pay for all highway, transit, and park-and-ride costs and would generate significant surpluses.
Genotype-by-Environment Interactions for Seed Composition Traits of Breeding Lines in The Uniform Peanut Performance Test
Authors: Isleib T. G. , Tillman B. L. , Pattee H. E. , Sanders T. H. , Hendrix K. W. , Dean L. O.
Published: November 2008

Peanut composition is influenced by several groups of factors: environmental, genetic, and their interaction. This study evaluated the relative contributions of these factors using data from the USDA-ARS quality testing program using samples from the multi-state Uniform Peanut Performance Tests (UPPT). Data were subjected to restricted maximum likelihood estimation of variance components reflecting the main effects of year, production region, location within region, genotype (cultivar or breeding line), and kernel grade (“seed size”) within genotype, and the interactions among these main effects. Genetic variation in oil content was low (9% of total variation); however, fatty acid composition of the oil was highly influenced by genotype (34–77%) with the exception of lignoceric acid (1%). Genetic influence on tocopherols was generally less than that of fatty acids. Environmental variation of tocopherols was greater than the variation attributable to genotype-by-environment interaction. The lowest genetic variation was observed in sugar content; however, environmental variation was high (68%). The magnitude of genetic influence on oil content and fatty acid concentrations suggests that these traits are amenable to improvement through breeding.
Total Synthesis and Antimicrobial Activity of (±)-Laurelliptinhexadecan-1-one and (±)-Laurelliptinoctadecan-1-one
Authors: Nimgirawath Surachai , Udomputtimekakul Phansuang , Pongphuttichai Samathi , Wanbanjob Asawin , Taechowisan Thongchai
Published: November 2008

The structures previously assigned to (+)-laurelliptinhexadecan-1-one (1a) and (+)-laurelliptinoctadecan-1-one (1b) from Cocculus orbiculatus (L.) DC. (Menispermaceae) have been confirmed by total synthesis of the racemic alkaloids. The key step of the synthesis involved formation of ring C of the aporphines by a radical-intiated cyclisation. Both (±)-laurelliptinhexadecan-1-one (1a) and (±)-laurelliptinoctadecan-1-one (1b) were inactive against Staphylococcus aureus ATCC25932, Escherichia coli ATCC10536 and Candida albicans ATCC90028.
Identification of a CREB‐dependent serotonergic pathway and neuronal circuit regulating foraging behavior in Caenorhabditis elegans: A useful model for mental disorders and their treatments?
Authors: Zubenko George S. , Jones Michelle L. , Estevez Annette O. , Hughes Hugh B. , Estevez Miguel
Published: November 2008

The cAMP‐response element binding protein (CREB)‐mediated cell signaling pathway is conserved through evolution and participates in a broad range of complex behaviors of divergent species including man. This study describes the integration of genetic, pharmacologic, and anatomic methods to elucidate a serotonergic signaling pathway by which the CREB homolog CRH‐1 controls foraging rate (FR) in the model organism Caenorhabditis elegans, along with the complete neuronal circuit through which this pathway operates. In the anterior afferent arm of the circuit, CRH‐1 controls FR by regulating the expression of tph‐1, the sole structural gene for tryptophan hydroxylase, in serotonergic sensory (ADF) neurons whose post‐synaptic effects are mediated through 5HT2‐like SER‐1 receptors. The posterior afferent limb of the circuit includes an interneuron (RIH) that does not express tph‐1 and whose serotonergic phenotype is dependent on the contribution of this neurotransmitter from another source, probably the ADF neurons. The postsynaptic effects of the RIH interneuron are mediated through 5HT1‐like SER‐4 receptors. This model has potential utility for the study of clinical disorders and experimental therapeutics. Furthermore, the discovery of serotonergic neurons that depend on other sources for their neurotransmitter phenotype could provide a mechanism for rapidly altering the number and distribution of serotonergic pathways in developing and adult nervous systems, providing a dimension of functional complexity that has been previously unrecognized. © 2008 Wiley‐Liss, Inc.
Evaluation of alginate–chitosan bioadhesive beads as a drug delivery system for the controlled release of theophylline
Authors: Elzatahry A. A. , Eldin M. S. Mohy , Soliman E. A. , Hassan E. A.
Published: November 2008

This study describes the preparation of mucoadhesive alginate–chitosan beads containing theophylline intended for colon‐specific delivery. The calcium alginate beads were coated with chitosan by the ionotropic hydrogelation method with a polyelectrolyte complex reaction between two oppositely charged polyions. The release profiles of theophylline from the beads were determined by ultraviolet–visible absorption measurement at 272 nm. Scanning electron microscopy was used for morphology observation. The in vitro mucoadhesive tests for particles were carried out with the freshly excised jejunum of Sprague‐Dawley rats. The bead particles, which ranged in size from 200 to 400 μm, exhibited excellent mucoadhesive properties. The results showed that the formulated coated beads succeeded in controlling the release of theophylline over a 24‐h period. In conclusion, the release of theophylline was found to be dependent on the composition of the beads, the component polymer and its possible interactions, and the bioadhesiveness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of high‐density polypropylene‐grafted polyethylene via a macromolecular reaction and its rheological behavior
Authors: Yao Zhen , Lu Zhan‐Quan , Zhao Xi , Qu Bang‐Wei , Shen Zhi‐Cheng , Cao Kun
Published: November 2008

High‐density polyethylene grafted isotactic polypropylene (PP‐g‐HDPE) was prepared by the imidization reaction between maleic anhydride grafted polyethylene and amine‐grafted polypropylene in a xylene solution. The branch density was adjusted by changes in the molar ratio between maleic anhydride and primary amine groups. Dynamic rheology tests were conducted to compare the rheological properties of linear polyolefins and long‐chain‐branched polyolefins. The effects of the density of long‐chain branches on the rheological properties were also investigated. It was found that long‐chain‐branched hybrid polyolefins had a higher storage modulus at a low frequency, a higher zero shear viscosity, a reduced phase angle, enhanced shear sensitivities, and a longer relaxation time. As the branch density was increased, the characteristics of the long‐chain‐branched structure became profounder. The flow activation energy of PP‐g‐HDPE was lower than that of neat maleic anhydride grafted polypropylene (PP‐g‐MAH) because of the lower flow activation energy of maleic anhydride grafted high‐density polyethylene (HDPE‐g‐MAH). However, the flow activation energy of PP‐g‐HDPE was higher than that of PP‐g‐MAH/HDPE‐g‐MAH blends because of the presence of long‐chain branches. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Radiopaque acrylic bone cements with bromine‐containing monomer
Authors: Rusu Marius Ciprian , Ibanescu Constanta , Cameliu Ichim Ionut , Riess Gerard , Popa Marcel , Rusu Daniela , Rusu Mihai
Published: November 2008

One important issue for the acrylic bone cements concerns the radiopacity, which may be achieved by different ways. In this work, a new bromine‐containing acrylic monomer, the 2‐(2‐bromopropionyloxy) propyl methacrylate (BPPM), was synthesized and proposed to be used for providing radiopaque bone cements. Different acrylic bone cements were realized by partially replacing the methyl methacrylate (MMA) monomer phase with 5–20% w/w of BPPM‐comonomer. The effect of this comonomer on the curing parameters of acrylic bone cements, on their thermal and rheological properties, water absorption, density, contact angle, compression tests, and radiopacity was studied. It appears that the presence of BPPM does provide radiopacity, improves the curing parameters by decreasing the maximum curing temperature and increasing the setting time. The new BPPM‐acrylic bone cements exhibit lower glass transition temperature and better thermal stability when compared with the classical radiolucent acrylic cements. Rheological measurements have shown that 10–20% w/w of BPPM in the liquid phase of acrylic bone cement formulations increase its flexibility, and may also induce a slight crosslinking reaction during the curing phase. BPPM‐modified acrylic bone cements present lower polymerization shrinkage and higher compression strength, and similar water uptake, porosity, and water contact angle as the radiolucent PMMA‐cements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of a dodecylsulfate‐modified magnesium–aluminum layered double hydroxide on the morphology and fracture of polystyrene and poly(styrene‐co‐acrylonitrile) composites
Authors: Realinho V. , Antunes M. , Arencón D. , Fernández A. I. , Velasco J. I.
Published: November 2008

Composites of polystyrene (PS) and poly(styrene‐co‐acrylonitrile) (SAN) containing a fraction of a dodecylsulfate‐modified Mg–Al layered double hydroxide (LDH) were prepared by means of a melt‐extrusion process. The structure and morphology were analyzed with wide‐angle X‐ray scattering and transmission electron microscopy, respectively. The X‐ray spectra of the PS matrix composite displayed the diffraction peak characteristic of the hybrid LDH basal plane at 2θ = 3.1 deg. The SAN matrix composite did not exhibit such a diffraction peak. Both PS and SAN composites displayed an intercalated type of morphology with respect to the LDH platelets, as assessed by transmission electron microscopy. A plasticizing effect due to the hybrid LDH particles was observed for all composites and was supported by a decrease in the glass‐transition temperature values and by Fourier transform infrared spectra. Besides tensile properties, the fracture toughness of the composites was compared with that of the pure polymers through the linear elastic fracture mechanics parameters. They were determined from fracture tests under a three‐point‐bending configuration. The results indicated that the effect of adding a small fraction of modified LDH particles to SAN caused an improvement in fracture toughness of 50% with respect to that of the pure polymer. Moreover, the relative increase in the fracture energy was about 200%. For PS matrix composites, both tensile properties and linear elastic fracture mechanics fracture parameters remained unaffected. These results were explained on the basis of the different plasticities developed by both polymers around the particles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of thermosensitive glycopolymers containing D‐glucose residue: Copolymers with N‐isopropylacrylamide
Authors: Shinde Vaishali S. , Pawar Vishwas U.
Published: November 2008

A new glycomonomer, 3‐acrylamido‐3‐deoxy‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose, was synthesized from D‐glucose. This monomer was homopolymerized and copolymerized with N‐isopropylacrylamide in different compositions by free‐radical polymerization. The composition of the copolymer was determined with 1H‐NMR spectroscopy. On acid hydrolysis, water‐soluble deprotected copolymers were obtained. The protected and deprotected copolymers showed a sharp cloud‐point temperature. A linear correlation was obtained between the lower critical solution temperatures and the concentration of glycomonomer in the copolymers © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Carboxymethyl guar: Its synthesis and macromolecular characterization
Authors: Pal Sagar
Published: November 2008

Guar gum was partially carboxymethylated by the reaction of the base polysaccharide with the sodium salt of monochloroacetic acid in presence of sodium hydroxide. The resulting products (carboxymethyl guar with different degrees of substitution) were characterized by a variety of material characterization techniques, such as intrinsic viscosity measurement, determination of molecular weight, elemental analysis, thermal analysis, 13C‐NMR spectra, and Fourier transform infrared analysis. Various grades of carboxymethyl guar gum, which were synthesized in the laboratory, were studied for their suitability as flocculants and viscosifiers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Monitoring with benthic fauna in Italian coastal lagoons: new tools for new prospects
Authors: Munari Cristina , Warwick Richard M. , Mistri Michele
Published: November 2008

The search for simple and effective descriptors of biological ecosystem components is a major challenge of monitoring the health of transitional waters.

The recent development of rapid environmental assessment techniques provides additional tools that can assist the monitoring and evaluation of the aquatic environment: (a) the taxonomic sufficiency perspective, which involves the identification of taxa only to a level of taxonomic resolution sufficient to permit the detection of changes in stressed assemblages; and (b) the taxonomic distinctness perspective, sample‐size/sample‐effort free indices that take into account the classification of species to higher categories along the phylogenetic/taxonomic tree. These techniques have rarely been applied to Italian transitional water ecosystems.

Quantitative data relating to the composition and abundance of macrofauna collected during several surveys between 1999 and 2005 from nine Italian transitional water (TW) ecosystems were analysed, in order to test whether these rapid environmental assessment techniques may have operational value in the management of these ecosystems.

This study emphasized a number of interesting features of taxonomic composition and relatedness of TW benthic macroinvertebrates: (a) analyses of the macrofauna in TWs at higher taxonomic resolution represents a valid tool in routine monitoring; (b) the taxonomic sufficiency is at quite a high taxonomic level (at the family level) in lagoonal systems; (c) the capacity of the taxonomic distinctness perspective to discriminate along gradients of environmental degradation, but also its difficulty in distinguishing between unperturbed and impacted sites where the benthic community is very low in species numbers.

Copyright © 2008 John Wiley & Sons, Ltd.
Survival rates for a declining population of bottlenose dolphins in Doubtful Sound, New Zealand: an information theoretic approach to assessing the role of human impacts
Authors: Currey Rohan J. C. , Dawson Stephen M. , Slooten Elisabeth , Schneider Karsten , Lusseau David , Boisseau Oliver J. , Haase Patti , Williams Jamelia A.
Published: November 2008

The bottlenose dolphins of Doubtful Sound, New Zealand are a declining population at the southern limit of the species' range, exposed to impacts from tourism and habitat modification. Patterns in apparent annual survival were analysed from photographic resightings of naturally marked adults (1990 to 2008) and calves within the first year of life (1994 to 2008) using capture‐recapture models.

The most parsimonious model for adults provided a time‐invariant, sex‐invariant estimate of survival (ϕa(1990–2008)=0.9374; 95% CI: 0.9170–0.9530), marginally lower than prior estimates for wild bottlenose dolphins.

The most parsimonious model for calves indicated a significant time‐variant decline in survival from an estimate similar to other populations (ϕc(1994–2001)=0.8621; 95% CI: 0.6851–0.9473) to a current estimate that is, to our knowledge, the lowest recorded for free‐ranging bottlenose dolphins (ϕc(2002–2008)=0.3750; 95% CI: 0.2080–0.5782).

Information theoretic evidence ratios suggested that observed patterns in calf survival were 22 times more likely to be explained by a decline coincident with the opening of a second tailrace tunnel for a hydroelectric power station than by a decline in any other year or across multiple years.

Projections using an age‐structured stochastic population model indicated that the current level of calf survival was unsustainable (population decline: 100% of model runs; population extinction: 41.5% of model runs) and was a key factor in the observed population decline in Doubtful Sound.

Copyright © 2008 John Wiley & Sons, Ltd.
Identification of a spatially efficient portfolio of priority conservation sites in marine and estuarine areas of Florida
Authors: Geselbracht Laura , Torres Roberto , Cumming Graeme S. , Dorfman Daniel , Beck Michael , Shaw Douglas
Published: November 2008

A systematic conservation planning approach using benthic habitat and imperilled species data along with the site prioritization algorithm, MARXAN, was used to identify a spatially efficient portfolio of marine and estuarine sites around Florida with high biodiversity value.

Ensuring the persistence of an adequate geographic representation of conservation targets in a particular area is a key goal of conservation. In this context, development and testing of different approaches to spatially‐explicit marine conservation planning remains an important priority.

This detailed case study serves as a test of existing approaches while also demonstrating some novel ways in which current methods can be tailored to fit the complexities of marine planning.

The paper reports on investigations of the influence of varying several algorithm inputs on resulting portfolio scenarios including the conservation targets (species observations, habitat distribution, etc.) included, conservation target goals, and socio‐economic factors.

This study concluded that engaging stakeholders in the development of a site prioritization framework is a valuable strategy for identifying broadly accepted selection criteria; universal target representation approaches are more expedient to use as algorithm inputs, but may fall short in capturing the impact of historic exploitation patterns for some conservation targets; socio‐economic factors are best considered subsequent to the identification of priority conservation sites when biodiversity value is the primary driver of site selection; and the influence of surrogate targets on portfolio selection should be thoroughly investigated to ensure unintended effects are avoided.

The priority sites identified in this analysis can be used to guide allocation of limited conservation and management resources.

Copyright © 2008 John Wiley & Sons, Ltd.
Risk factors in relation to human deaths and other tsunami (2004) impacts in Sri Lanka: the fishers'‐eye view
Authors: Venkatachalam A. J. , Price A. R. G. , Chandrasekara S. , Senaratna Sellamuttu S.
Published: November 2008

This study examines the perceptions of 500 Sri Lankan fishers about influences on the outcome of the 2004 Asian tsunami. It is based upon analysis of questionnaire data on 13 natural environmental and development risk factors, in relation to human deaths and house damage (impact indicators).

Mangroves, coral reefs and sand dunes afforded protection against tsunami damage (67–94% of fisher responses), as did housing and roads.

Fishers overall believed rivers/estuaries, concave coastlines and hotels exacerbated impacts. However, a significantly greater proportion of fishers living within 100 m of the coast reported that rivers/estuaries had a protective role than those living further inland. Rivers seemingly diverted ‘tsunami water’ far inland, where it overflowed and caused damage.

Risk and damage are multi‐faceted concepts and measurable in different ways. Findings are considered in the light of ecological studies and modelling, with special reference to mangroves, whose alleged protective role has become equivocal during post‐tsunami research.

Insights of fishers and other communities with intuitive knowledge add a valuable perspective to the understanding of natural disasters and environmental change. This approach is seen as complementary rather than an alternative approach to purely ‘scientific’ research.

Copyright © 2008 John Wiley & Sons, Ltd.
Galaxy mergers at high resolution: From elliptical galaxies to tidal dwarfs and globular clusters
Authors: Bournaud F. , Bois M. , Emsellem E. , Duc P.‐A.
Published: November 2008

Numerical simulations of galaxy mergers are a powerful tool to study these fundamental events in the hierarchical builtup of galaxies. Recent progress have been made owing to improved modeling, increased resolution and large statistical samples. We present here the highest‐resolution models of mergers performed so far. The formation of a variety of substructures ranging from kinematically decoupled cores to globular‐like clusters is directly resolved. In a resolution study, we show that the large‐scale structure of elliptical‐like merger remnants can be affected by the resolution, and a too modest resolution may affect the numerical predictions on the properties of major merger remnants: understanding precisely which kind of event or succession of events has formed the various types of elliptical galaxies remains an open challenge. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of the host galaxy kinematics on nuclear activity
Authors: Dumas G. , Mundell C.G. , Emsellem E. , Nagar N.
Published: November 2008

We investigate the kinematic properties of the stars and ionised gas in the circumnuclear regions of a matched sample of nearby Seyfert and non‐active galaxies, using the SAURON Integral‐Field Unit (IFU) on the William Herschel Telescope (WHT). In both active and non‐active galaxies, the stellar velocity fields present regular rotation patterns. After removal of the non‐gravitational components due to nuclear activity (e.g., AGN‐driven outflows) in the case of the Seyfert galaxies, the ionised gas kinematics in both populations is dominated by rotation. The non‐active galaxies present a global alignment between stellar and gaseous kinematics while majority of Seyfert galaxies present strong kinematics misalignments between the two components. A more refined analysis of our two‐dimensional kinematics maps reveal evidence for deviations from axial‐symmetry in the gaseous velocity fields. These deviations are moreover stronger in the case of Seyfert galaxies than their associated non‐active galaxies. This result suggests the presence of weak dynamical perturbations in the circumnuclear regions of Seyfert galaxies and provides a tentative link between nuclear activity and the host galaxy dynamics in these regions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of stellar orbits in the Galactic centre
Authors: Gualandris A. , Harfst S. , Merritt D. , Mikkola S.
Published: November 2008

We describe a novel N‐body code designed for simulations of the central regions of galaxies containing massive black holes. The code incorporates Mikkola's “algorithmic” chain regularization scheme including post‐Newtonian terms up to PN2.5 order. Stars moving beyond the chain are advanced using a fourth‐order integrator with forces computed on a GRAPE board. Performance tests confirm that the hybrid code achieves better energy conservation, in less elapsed time, than the standard scheme and that it reproduces the orbits of stars tightly bound to the black hole with high precision. The hybrid code is applied to two sample problems: the effect of finite‐N gravitational fluctuations on the orbits of the S‐stars; and inspiral of an intermediate‐mass black hole into the galactic centre. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Large‐scale distribution of interstellar matter in the central region of our Galaxy
Authors: Ferrière K.
Published: November 2008

In this paper, we review the present observational knowledge on the physical properties and the large‐scale spatial distribution of interstellar matter in the central region of our Galaxy, out to a distance of 3 kpc from the Galactic center. We mainly focus on the interstellar gas, which contains ∼98 % of the total interstellar mass, leaving the remaining ∼2 % to interstellar dust. In a second step, we present a global model of the interstellar gas distribution, which incorporates the relevant results of a vast number of observational studies as well as those of numerical simulations of gas flows in the gravitational potential of a barred galaxy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Termination of star formation by BH feedback in equal‐ and unequal‐mass mergers of disk and elliptical galaxies
Authors: Johansson P.H. , Naab T. , Burkert A.
Published: November 2008

We present binary galaxy merger simulations of gas‐rich disks (Sp‐Sp), of early‐type galaxies and disks (E‐Sp, mixed mergers), and mergers of early‐type galaxies (E‐E, dry mergers) with varying mass ratios and different progenitor morphologies. The simulations include radiative cooling, star formation and black hole (BH) accretion and the associated feedback processes. We find for Sp‐Sp mergers, that the peak star formation rate and BH accretion rate decrease and the growth timescales of the central black holes and newly formed stars increase with higher progenitor mass ratios. The termination of star formation by BH feedback in disk mergers is significantly less important for higher progenitor mass ratios (e.g. 3:1 and higher). In addition, the inclusion of BH feedback suppresses efficiently star formation in dry E‐E mergers and mixed E‐Sp mergers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sigma‐drop in galaxies and the sigma‐metallicity degeneracy
Authors: Koleva M. , Prugniel P. , De Rijcke S.
Published: November 2008

In some galaxies, the central velocity dispersion, σ, is depressed with respect to the surroundings. This sigma‐drop phenomenon may have different physical origins, bearing information about the internal dynamics of the host galaxy. In this article, we stress the importance also of observational artifacts due to the σ ‐metallicity degeneracy: when a spectrum of a population is compared with a template of miss‐matched metallicity, the velocity dispersion may be wrongly estimated. A sigma‐drop may appear in place of a metallicity peak. The discussion is illustrated using VLT/FORS spectra of diffuse elliptical galaxies. Some of the sigma‐drop galaxies reported in the literature may be analysis artifacts. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the structure of tidal tails
Authors: Küpper A.H.W. , Macleod A. , Heggie D.C.
Published: November 2008

We examine the longitudinal distribution of the stars escaping from a cluster along tidal tails. Using both theory and simulations, we show that, even in the case of a star cluster in a circular galactic orbit, when the tide is steady, the distribution exhibits maxima at a distance of many tidal radii from the cluster. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An instability in triaxial stellar systems
Authors: Antonini F. , Capuzzo‐Dolcetta R. , Merritt D.
Published: November 2008

The radial‐orbit instability is a collective phenomenon that has heretofore only been observed in spherical systems. We find that this instability occurs also in triaxial systems, as we checked by performing extensive N ‐body simulations whose initial conditions were obtained by sampling a self‐consistent triaxial model of a cuspy galaxy composed of luminous and dark matter (Capuzzo‐Dolcetta et al. 2007). N ‐body simulations show a time evolution of the galaxy that is not due to the development of chaotic motions but, rather, to the collective instability induced by an excess of radially biased (box) orbits. The instability quickly transforms such model into a more prolate configuration, with 0.64 < b/a < 0.77 and 0.6 < c/a < 0.7 for the dark halo and 0.64 < b/a < 0.77 and 0.59 < c/a < 0.67 for the luminous matter. Stable triaxial, cuspy galaxies with dark matter halo are obtained when the mass contribution of radially biased orbits to the solution is reduced. These results constitute the first evidence of radial orbit instability in triaxial stellar systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ordered and chaotic spiral arms
Authors: Patsis P.A.
Published: November 2008

The stellar flow at the arms of spiral galaxies is qualitatively different among different morphological types. The stars that reinforce the spiral arms can be either participating in an ordered or in a chaotic flow. Ordered flows are associated with normal (non‐barred) spiral galaxies. Typically they are described with precessing ellipses corresponding to stable periodic orbits at successive energies (Jacobi constants). On the contrary, the spiral arms in barred‐spiral systems may be supported by stars in chaotic motion. The trajectories of these stars are associated with the invariant manifolds of the unstable Lagrangian points (L1,2). Response and orbital models indicate that this kind of spirals either stop at an azimuth smaller than π /2, or present large gaps at about this angle. Chaotic spirals appear in strong bars having (L1,2) close to the ends of the bar. The arms of barred‐spiral systems with corotation away from the end of the bar can be either as in the case of normal spirals, or supported by banana‐like orbits surrounding the stable Lagrangian points (L4,5). We find also models combining ordered and chaotic flows. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Velocity distribution in stellar disks: Are higher order moments negligible?
Authors: Theis Ch. , Vorobyov E.I.
Published: November 2008

We analysed the structure of the velocity space in galactic disks which are subject to a rotating spiral perturbation. A key assumption of the Boltzmann moment equation approach is the zero‐heat flux approximation, i.e. the neglection of third order velocity terms. We tested this assumption by performing test particle simulations for stars in a disk galaxy subject to a rotating spiral perturbation. The third order velocity moments were typically small (normalized values reach 25% of the initial velocity dispersion) and uncorrelated over almost all of the disk with the exception of the 4:1 resonance region (UHR). Even there, the values are smaller than the initial velocity dispersion. Far outside the resonance position a bimodal distribution characterizes the 3rd order moments. A qualitatively similar distribution is found for the 5th order terms. Contrary to these odd moments, the 4th order terms exceed almost everywhere the initial velocity dispersion. Therefore, an extension of the Boltzmann moment equations by only one moment, i.e. up to the third order, is not reasonable without including the fourth order terms. For all moments a large‐scale structure (either two‐armed or four‐armed) is clearly visible inside the UHR. The odd moments show a patchy irregular pattern outside the UHR, whereas the fourth order moments show also a clear large‐scale pattern. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiple stellar populations in dwarf spheroidal galaxies
Authors: Ural U. , Wilkinson M.
Published: November 2008

We study the detectability of multiple stellar populations in small kinematic data sets. We investigate the expected significance of detection in several cases, with different parameters for the populations, i.e. number of stars, the separation between the velocity dispersions, the errors in the velocities and fraction of stars in the subpopulations. We find that for data sets smaller than 100 stars, it is hard to get detections at the 3σ confidence level using only kinematic data and conclude that additional information must be taken into account for the robust identification of distinct populations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Post‐Newtonian simulations of super‐massive black hole binaries in galactic nuclei
Authors: Berentzen I. , Preto M. , Berczik P. , Merritt D. , Spurzem R.
Published: November 2008

We present some preliminary results from recent numerical simulations that model the evolution of super‐massive black hole (SMBH) binaries in galactic nuclei. Including the post‐Newtonian terms for the binary system and adopting appropriate models for the galaxies allows us, for the.rst time, to follow the evolution of SMBH binaries from kpc scales down to the coalescence phase. We use our results to make predictions of the detectability of such events with the gravitational wave detector LISA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Orbital complexity in a time‐dependent potential
Authors: Boily C.M. , Detemple L. , Faber N.T.
Published: November 2008

We introduce a method to detect irregular or chaotic orbits in gravitational potentials based on a wavelet transform of stellar orbits. The method is based on a treatment of normalised frequency power‐spectrum coefficients, which we interpret as occupation probabilities (or, weights) of individual frequency modes. Each probability is fed to a Shannon informationentropy formula, before summing over the whole spectrum to compute the total entropy S. This entropy is then monitored in time as the wavelet coefficients change: each orbit is classi.ed as regular or not according to S and its dispersion. We find that diagrams of entropy versus entropy dispersion allow to identify orbits in a simple and efficient way, similarly to surface‐of‐section analysis but requiring less integration time. We apply the method to the case of a gravitational potential modulated by the periodic motion of a massive black hole and find that some 19% of stars are now shifted to highly irregular motion as a result of black hole orbital motion. This is the same fraction of stars that orbit within the black hole radius of influence. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of galaxies in pairs: Learning from simulations
Authors: Matteo P. Di , Combes F. , Chilingarian I. , Melchior A.‐L. , Semelin B.
Published: November 2008

Numerical simulations represent an essential instrument to understand the physical processes occurring in interacting and merging systems, giving insight into the evolution of their morphological and kinematical properties, their star‐formation histories, metal enrichement, etc. After a inexhaustive description of some of the physical phenomena related to galaxy collisions, we present the GalMer Project, a computational effort aiming at studying statistically the role that interactions play in determining galaxy evolution. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A behavioral account of compensation awarding decisions
Authors: Tsai Claire I. , Hsee Christopher K.
Published: November 2008

Suppose an individual loses an irreplaceable object and someone else is at fault. How much should he be compensated? Normatively, compensation should equal the value (utility) to the victim. Our experiments demonstrate that compensation decisions often ignore value and are instead based on cost (how much the victim originally paid for the item) except when cost is zero. For example, we found that people awarded $200 for a destroyed item worth $500 to the victim if the cost was $200; however, they awarded $500 if the original cost was zero. We explain these phenomena in terms of lay scientism (the tendency to base decisions on objective factors) and discuss how the prevalent cost‐based compensation rule hurts consumer welfare. Copyright © 2008 John Wiley & Sons, Ltd.
The Influence of Ligand Valency on Aggregation Mechanisms for Inhibiting Bacterial Toxins
Authors: Sisu Cristina , Baron Andrew J. , Branderhorst Hilbert M. , Connell Simon D. , Weijers Carel A. G. M. , de Vries Renko , Hayes Edward D. , Pukin Aliaksei V. , Gilbert Michel , Pieters Roland J. , Zuilhof Han , Visser Gerben M. , Turnbull W. Bruce
Published: November 2008

Divalent and tetravalent analogues of ganglioside GM1 are potent inhibitors of cholera toxin and Escherichia coli heat‐labile toxin. However, they show little increase in inherent affinity when compared to the corresponding monovalent carbohydrate ligand. Analytical ultracentrifugation and dynamic light scattering have been used to demonstrate that the multivalent inhibitors induce protein aggregation and the formation of space‐filling networks. This aggregation process appears to arise when using ligands that do not match the valency of the protein receptor. While it is generally accepted that multivalency is an effective strategy for increasing the activity of inhibitors, here we show that the valency of the inhibitor also has a dramatic effect on the kinetics of aggregation and the stability of intermediate protein complexes. Structural studies employing atomic force microscopy have revealed that a divalent inhibitor induces head‐to‐head dimerization of the protein toxin en route to higher aggregates.
pH‐Controlled Molecular Switches and the Substrate‐Directed Self‐Assembly of Molecular Capsules with a Calix[4]pyrrole Derivative
Authors: Cafeo Grazia , Kohnke Franz H. , Valenti Luca , White Andrew J. P.
Published: November 2008

10α,20α‐Bis(4‐nitrophenyl)calix[4]pyrrole (1) forms 1:1 complexes with anions of selected aromatic hydroxy acids in which the host orientation within the guest is controlled by a change in the pH value. Some bis‐anionic guests, including those obtained from 4‐hydroxybenzoic acid, 1,4‐ and 1,3‐benzenedicarboxylic acids, induce the self‐assembly of molecular capsules involving two molecules of the receptor. 1H NMR data and solid‐state structures of the 1:1 complex of 1 with p‐C6H4(COOH)(COO−)+NMe4 and the 2:1 capsule [(1)2m‐C6H4(COO−)2(+NMe4)2] provide structural details in solution and in the solid state.
Excitatory‐inhibitory relationship in the fascia dentata in the Ts65Dn mouse model of down syndrome
Authors: Belichenko Pavel V. , Kleschevnikov Alexander M. , Masliah Eliezer , Wu Chengbiao , Takimoto‐Kimura Ryoko , Salehi Ahmad , Mobley William C.
Published: November 2008

Down syndrome (DS) is a neurological disorder causing impaired learning and memory. Partial trisomy 16 mice (Ts65Dn) are a genetic model for DS. Previously, we demonstrated widespread alterations of pre‐ and postsynaptic elements and physiological abnormalities in Ts65Dn mice. The average diameter of presynaptic boutons and spines in the neocortex and hippocampus was enlarged. Failed induction of long‐term potentiation (LTP) due to excessive inhibition was observed. In this paper we investigate the morphological substrate for excessive inhibition in Ts65Dn. We used electron microscopy (EM) to characterize synapses, confocal microscopy to analyze colocalization of the general marker for synaptic vesicle protein with specific protein markers for inhibitory and excitatory synapses, and densitometry to characterize the distribution of the receptor and several proteins essential for synaptic clustering of neurotransmitter receptors. EM analysis of synapses in the Ts65Dn vs. 2N showed that synaptic opposition lengths were significantly greater for symmetric synapses (∼18%), but not for asymmetric ones. Overall, a significant increase in colocalization coefficients of glutamic acid decarboxylase (GAD)65/p38 immunoreactivity (IR) (∼27%) and vesicular GABA transporter (VGAT)/p38 IR (∼41%) was found, but not in vesicular glutamate transporter 1 (VGLUT1)/p38 IR. A significant overall decrease of IR in the hippocampus of Ts65Dn mice compared with 2N mice for glutamate receptor 2 (GluR2; ∼13%) and anti‐γ‐aminobutyric acid (GABA)A receptor β2/3 subunit (∼20%) was also found. The study of proteins essential for synaptic clustering of receptors revealed a significant increase in puncta size for neuroligin 2 (∼13%) and GABAA receptor‐associated protein (GABARAP; ∼13%), but not for neuroligin 1 and gephyrin. The results demonstrate a significant alteration of inhibitory synapses in the fascia dentata of Ts65Dn mice. J. Comp. Neurol. 512:453–466, 2009. © 2008 Wiley‐Liss, Inc.
Structural Changes in 2‐Diarylthiophene‐Substituted Starburst Compounds upon Charging: A Theoretical and Spectroelectrochemical Study
Authors: Šolc Roland , Lukeš Vladimír , Rapta Peter , Hartmann Horst , Dunsch Lothar
Published: November 2008

The role of charging in structural changes of 2‐diarylaminothiophene‐substituted starburst compounds is clarified by combining theoretical and spectroelectrochemical studies. A systematic and comparative theoretical calculation based on density functional theory and semiempirical Austin Model 1 (AM1) calculations is performed on the neutral and charged states of four model tris(5‐diarylamino‐5‐thienyl)‐terminated starburst compounds with a central triphenylamine and 1,3,5‐triphenylbenzene moiety. Our results indicate that the charging of molecules leads to structural changes by quinoid‐type components mostly on the dendrimers terminated by phenothiazinyl fragments. Based on the optimal geometries, the spectroscopic properties were calculated using the semiempirical Zerner’s intermediate neglect overlap method. The presented theoretical results and the spin electron distributions of charged states and their spectra are supported by the spectroelectrochemical observations caused by the different electron localization within the studied molecules after charging. The satisfactory agreement between theoretical electronic transitions and experimental values indicates that a rational design of tunable molecular layers in organic devices based on the starburst compounds described is possible.
Elastic constant measurements of super ionic LiKSO4:Na single crystals
Authors: Varughese G. , Kumar A. Santhosh , Philip J. , Louis G.
Published: November 2008

Elastic properties of sodium doped Lithium potassium sulphate, Li K0.9 Na 0.1 SO4, crystal has been studied by ultrasonic Pulse Echo Overlap [PEO] technique and are reported for the first time. The controversy regarding the type of crystal found while growth is performed at 35 °C with equimolar fraction of Li2SO4H2O, K2SO4 and Na2SO4 has been resolved by studying the elastic properties. The importance of this crystal is that it exhibits pyroelectric, ferroelectric and electro optic properties. It is simultaneously ferroelastic and superionic. The elastic properties of LiK0.9Na0.1SO4 crystal are well studied by measuring ultrasonic velocity in the crystal in certain specified crystallographic directions and evaluating the elastic stiffness constants, compliance constants and Poisson's ratios. The anisotropy in the elastic properties of the crystal are well explained by the pictorial representation of the surface plots of phase velocity, slowness and linear compressibility in a‐b and a‐c planes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and optical investigations on Mn doped Li2B4O7 crystals
Authors: Kar S. , Verma S. , Bartwal K. S.
Published: November 2008

Lithium tetraborate crystals have great demand due to its non‐critical phase matching at 90°. Transparent and good optical quality single crystals of undoped and Mn doped Li2B4O7 were grown by Czochralski technique in air atmosphere. The crystalline phase was determined by X‐ray diffraction. Doping of Mn in the grown crystals was confirmed by energy dispersive analysis of X‐rays (EDAX) technique. Transmission spectra show that the crystal is transparent in the visible region. Birefringence interferograms were recorded to qualitatively analyse the optical homogeneity of the grown crystals and to quantify the birefringence of the samples in desired crystal direction. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Practical and Benign Synthesis of Primary Amines through Ruthenium‐Catalyzed Reduction of Nitriles
Authors: Enthaler Stephan , Junge Kathrin , Addis Daniele , Erre Giulia , Beller Matthias
Published: November 2008

The catalytic hydrogenation of nitriles represents an atom‐economic and valuable route to amines. In the present study, the ruthenium‐catalyzed hydrogenation of various organic nitriles to give primary amines has been examined in detail. Straightforward ruthenium complexes modified by cheap and widely available triphenylphosphine allow for the efficient and general reduction of various aryl, alkyl, and heterocyclic nitriles. By using a practical in situ catalyst composed of [Ru(cod)(methylallyl2)] and PPh3, excellent yields and chemoselectivity were achieved. Moreover, the catalyst system displays broad functional group tolerance.