bluuebunny/crossref_metadata_2025 huggingface dataset:
Local starbursts seen when the Universe was 2–4 Gyr old
Authors: Petty S. M. , de Mello D. F. , Gardner J. P. , Gallagher J. S.
Published: January 2010

We explore the multiwavelength properties of three nearby starburst galaxies: NGC 3079, NGC 7673, and Mrk 08. We established that each of these galaxies has similar rest-frame far-ultraviolet (FUV) morphologies as Lyman-break galaxies (LBGs) at z ~ 1.5 and 4, when the age of the Universe was ~ 4.3 and ~ 1.6 Gyr, respectively. LBGs are at an important stage in galaxy evolution when the Universe had a peak in the star-formation-rate density. Many LBGs are primarily composed of star-forming clumps, i.e., stellar clusters, with a significant lack of older stellar populations. Here, we present the comparison of the spectral-energy distributions (SEDs) of three nearby starburst galaxies with those of typical LBGs. From our nearby sample, each object has been artificially redshifted to observe what the galaxies would look like at z ~ 1 to 4 in the rest-frame FUV. NGC 3079 is an edge-on Seyfert 2 galaxy. It has a bright bulge and is interacting with two other galaxies, with extended Hi only along NGC 3079. The redshifting process changes its appearance, so that at high z it looks like a chain galaxy with multiple knots of star formation and no bulge. NGC 7673 has extended Hi and the star formation is mostly within the inner optical region in the multiple star-forming clumps defining the galaxy morphology. In the FUV, the galaxy looks highly compact with little detail resolved. As it is artificially redshifted, the galaxy continues to look more spherical. Mrk 8 is a merging pair, with the two galaxies observable in the visible spectrum. It is classified as a Wolf–Rayet galaxy, which suggests a very young burst, and is composed of several large star-forming regions. The FUV image does not resolve the separate galaxies, and the appearance remains similar for each redshift. We use the Gini coefficient, M20, and the Sérsic index to quantify the morphologies. The SEDs of the objects have similarities with LBG stellar population models. Because these local galaxies can be studied in more detail, they act as a bridge between nearby observations of starburst galaxies and high-z starburst galaxies such as LBGs.
The molecular cloud and embedded young stellar population associated with IRAS 18236–1205
Authors: Retes Ricardo , Luna Abraham , Mayya Divakara , Carrasco Luis
Published: January 2010

We test a membership method to select embedded young stellar objects (YSOs) from a Galactic molecular cloud with ongoing massive star formation using multiband analysis. We select and discuss the embedded stellar population in the molecular cloud associated with IRAS 18235−1205, a small, geometrically well-defined Galactic molecular cloud. The IRAS source has infrared fluxes characteristic of an UCHii region, CS(J = 2 − 1) emission, and methanol and water maser emission, suggesting that this region is a good candidate for studies of young, massive star formation. The selection method of embedded stellar populations is based on the spatial distribution of 13CO(J = 1 − 0) and Spitzer/MIPS 24 μm point sources. Photometric analysis using near/mid-infrared images are used to test our selection criteria. Three objects are associated with the IRAS source; two have a characteristic spectral-energy distribution (SED) of a Class I/0 object (protostar) and the third has an SED of Class II.
Internal dynamics of the NGC 3603 young cluster
Authors: Rochau Boyke , Brandner Wolfgang , Stolte Andrea , Gennaro Mario , Henning Thomas
Published: January 2010

Starburst clusters are spectacular young and dense stellar systems containing copious numbers of massive O-type and Wolf–Rayet stars. These objects depict a stellar population comprising stars over the entire mass range, making them ideal objects to study cluster formation and evolution as well as to test and calibrate stellar evolutionary models. Among the Galactic spiral-arm starburst clusters, NGC 3603 Young Cluster (YC), which is located in the Carina spiral arm, is the youngest and most compact one. Galactic starburst clusters also serve as templates for extragalactic super star clusters as observed, e.g., in the Antennae galaxies. Based on two epochs (obtained 10 yr apart) of high-quality astrometric HST/WFPC2 observations, we derive individual proper motions for several hundred stars. The proper motions enable us to distinguish cluster members from field stars, and to derive a first estimate of the internal cluster dynamics. Photometry of the clean sample of cluster stars allows us to create color–magnitude diagrams (CMDs) that are not contaminated by field stars, and to compare the sequence of cluster members with different sets of theoretical isochrones and evolutionary tracks. We clearly identify a lower-mass pre-main-sequence and a higher-mass main-sequence stellar population in NGC 3603. A particular focus of our comparison with theoretical isochrones is the exact shape and extent of the pre-main-sequence/main-sequence transition region in NGC 3603 YC. The proper motions also contain dynamical information. From this, we derive a velocity dispersion, which leads to the first dynamical mass estimate of the NGC 3603 cluster. We also investigate whether or not NGC 3603 YC is virialized, and study evidence for primordial versus dynamical mass segregation. Past and future evolution of NGC 3603 YC can be studied and will tell us about the clusters ‘fate’ and its long-term survival chances.
Nonradial pulsations in the open cluster NGC 3766
Authors: Roettenbacher Rachael M. , Amouzou Ernest C. , McSwain M. Virginia
Published: January 2010

Nonradial pulsations (NRPs) are a proposed mechanism for the formation of decretion disks around Be stars. They are important tools to study the internal structure of stars. NGC 3766 has an unusually large fraction of transient Be stars, so it is an excellent location to study the formation mechanism of Be-star disks. High-resolution spectroscopy can reveal line-profile variations from NRPs, allowing measurements of both the degree, l, and azimuthal order, m. However, spectroscopic studies require large amounts of time with large telescopes to achieve the necessary high signal-to-noise ratio and time-domain coverage. On the other hand, multicolor photometry can be performed more easily with small telescopes to measure l only. Here, we present representative light curves of Be stars and nonemitting B stars in NGC 3766 from the CTIO 0.9m telescope in an effort to study NRPs in this cluster.
Extreme-mass-ratio solar-type binaries and their implications for cluster environs
Authors: Samec R. G. , Labadorf Christa M. , Figg E. R. , Loflin Trevor S. , Behn Gregory R. , Hawkins Nathan A. , Chamberlain Heather A. , Faulkner D. R. , Van Hamme W.
Published: January 2010

During the past decade, the number known shallow-amplitude, yet totally eclipsing, extreme-mass-ratio binaries has increased from one (AW UMa, which is now in doubt) to about a dozen. Statistics are accumulating that will tell us the nature of these once rare systems. These individual interacting field binaries are believed to be the progenitors of FK Comae-type fast-rotating subgiants, which are similar to the cluster stars called ‘variable blue stragglers.’ We review our recent observations and new analyses of the individual systems, V409 Hya, GSC 1283 0053 Ori, GSC 2537 520 CVn, using the 2007 Wilson Code and summarize results from our previous observations (V802 Aql, V902 Sgr) and those from the literature (e.g., CK Boo, GR Vir, HV Aqr, UY UMa, EM Pis, CU Tau, TV Mus) to disclose a preliminary picture of the character of this interesting class of binary stars.
Astrometry and photometry of stars and star clusters in M33
Authors: San Roman Izaskun , Sarajedini Ata , Gallart Carme , Aparicio Antonio
Published: January 2010

We present positions and magnitudes of stars and star clusters in a 1°
× 1° area centered on M33. The survey is based on deep
archival ground-based images using the MegaPrime camera on the 3.6m
Canada–France–Hawaii telescope. We
provide u′, g′,
r′, i′,
z′ magnitudes by performing standard profile-fitting
photometry of these images and apply image classification algorithms such as
SExtractor. We also present a catalog of extended sources by
applying visual-inspection classification. This complete catalog provides
promising targets for deep photometry with HST and for
high-resolution spectroscopy to study the structure and star-formation history
of the disk and halo of M33.
Study of the young and old compact stellar cluster population in M81
Authors: Santiago-Cortés M. , Mayya Y. D. , Rosa-González D.
Published: January 2010

We study the population of compact stellar clusters in M 81 using the HST/ACS images in the filters F435W, F606W and F814W that cover a total field of view of approximately 340 square arcmin, the largest area covered to date for this galaxy. We present details about the selection criteria, which were based on both morphological and photometrical features. The extracted sample of compact stellar clusters shows the presence of two cluster populations, a blue cluster group (young) with more than 300 objects, and a red cluster group (old) containing 138 objects. Surprisingly, the young group lacks clusters more massive than 10 000 M⊙ which are present in large numbers in its neighbor M 82. The luminosity function of the young group follows a power-law distribution with an index of 2.0. The luminosity function of the red group closely resembles that of the globular clusters in the Milky Way. Assuming an age of 5 Gyr, these red clusters have masses between 0.1 and 10 × 106 M⊙.
Astrophysical properties of binary star clusters in the Small Magellanic Cloud
Authors: Santos João F. C. , Schmidt Alex A. , Bica Eduardo
Published: January 2010

To study the evolution of binary star clusters, we have imaged seven systems in the Small Magellanic Cloud with the SOAR 4m telescope using B and V filters. The sample contains pairs with well-separated components (d < 30 pc) as well as systems that apparently have merged, as evidenced by their unusual structures. By employing isochrone fitting to their color–magnitude diagrams, we have determined reddening values, ages and metallicities, and by fitting King models to their radial stellar-density profiles we estimated core radii. Disturbances of the density profiles are interpreted as evidence of interactions. Properties such as the distances between their components and their age differences are addressed in terms of the timescales involved, to assess the physical connection of the system. In two cases, the age difference is more than 50 Myr, which suggests a chance alignment, capture or sequential star formation.
Sulfur in the globular clusters 47 Tuc and NGC 6752
Authors: Sbordone L. , Chieffi A. , Limongi M. , Caffau E. , Ludwig H.-G. , Bonifacio P.
Published: January 2010

The light elements Li, O, Na, Al, and Mg are known to show star-to-star variations in the globular clusters 47 Tuc and NGC 6752. We have investigated the behavior of the α element sulfur, for which no previous measurements exist in any Galactic globular cluster. We used high-resolution UVES spectra of Si multiplet 1 around 923 nm, and determined S abundances by means of ATLAS static plano-parallel models. NLTE corrections were applied and 3D corrections were also computed from co5bold 3D hydrodynamical models. Sulfur has been measured in four subgiant stars in NGC 6752, leading to an average value of [S/Fe] = +0.49 ± 0.15 dex, consistent with what is observed in field stars of similar metallicity. In 47 Tuc, we measured S in four turnoff (TO) and five subgiant (SG) stars, for an average value of [S/Fe] = 0.18 ± 0.14 dex. While the measurement errors are consistent with a constant value among all cluster stars analyzed, we detected a highly significant correlation with sodium abundance, as well as a tentative one with silicon. The sulfur–sodium correlation is difficult to explain in terms of nucleosynthesis. Given its high statistical significance, it is also difficult to dismiss it as fortuitous. Until better data for more stars are available, the question as to its origin remains open.
The massive star-forming region Cygnus OB2
Authors: Wright N. J. , Drake J. J.
Published: January 2010

We present results from a catalogue of 1696 X-ray point sources detected in the massive star-forming region Cygnus OB2, the majority of which have optical or near-infrared associations. We derive ages of 3.5 and 5.25 Myr for the stellar populations in our two fields, in agreement with recent studies that suggest that the central 1–3 Myr-old OB association is surrounded and contaminated by an older population with an age of 5–10 Myr. The fraction of sources with protoplanetary disks, as traced by K-band excesses, is unusually low. Although this has previously been interpreted as due to the influence of the large number of OB stars in Cyg OB2, contamination from an older population of stars in the region could also be responsible. An initial mass function is derived and found to have a slope of Γ = −1.27, in agreement with the canonical value. Finally, we introduce the recently approved Chandra Cygnus OB2 Legacy Survey that will image a 1 square degree area of the Cygnus OB2 association to a depth of 120~ks, likely detecting ~ 10 000 stellar X-ray sources.
A 40 Gbps electro-absorption modulator integrated laser modeling method for optical transmitter in ultra-wide band radio-over-fiber systems
Authors: Deshours Frédérique , Billabert Anne-Laure , Algani Catherine , Blache Fabrice , Rumelhard Christian , Alquié Georges
Published: January 2010

The great interest of optical fiber links in communicating systems especially in ultra-wide band (UWB) communications has grown up in the last decade and requires co-simulation for mixed circuits design exploiting both optical and microwave domains. In this paper, we report an original modeling method of an electro-absorption modulator associated with a distributed-feedback laser to simulate an optical transmitter of an UWB over fiber system. Large signal optoelectronic device models can be developed and implemented in a high-frequency simulator, such as advanced design system-Ptolemy to analyze the performances of fiber radio links and study the impact of the transmitter characteristics. This specific simulation way, taking into account precisely electrical characteristics of both electrical and optical circuits, links two different frequency domains by coupling electrical and optical modules in the same system simulator. Therefore, a complete simulation of an UWB multi-band orthogonal frequency division multiplexing signal transmission over fiber with an external modulator is investigated.
SIP antenna on 0.13 µm SiGe technology at 79 GHz for SRR automotive radar
Authors: Pinto Yenny , Person Christian , Gloria Daniel , Cathelin Andreia , Belot Didier , Pruvost Sébastien , Plana Robert
Published: January 2010

This paper describes the analysis and the design of an integrated antenna on 0.13 µm SiGe BICMOS technology. A non-resonant dipole antenna integrated on SiGe is electromagnetically coupled to a radiating element reported on a printed circuit board (PCB) substrate. This integrated solution, also compatible with system in package (SIP) concept, provides significant improvements with respect to direct System On Chip (SoC) integration. The main objective of this SIP antenna lies on the optimization of integrated millimeter wave front-ends modules, considering the immediate antenna environment (especially the lossy substrate and technological dielectric/metallic levels), in order to achieve performances compatible with short range radar specifications at 79–81 GHz. One solution, using a RT/Rogers Duroid 6006 PCB (er = 6, thicknessh = 127 µm), is presented, providing a 2.93 dBi gain, and 45% radiation efficiency antenna.
Modeling effects of tidal and wave mixing on circulation and thermohaline structures in the Bering Sea: Process studies
Authors: Hu Haoguo , Wang Jia
Published: January 2010

Ocean circulation and the tidal current in the Bering Sea are simulated simultaneously using a coupled ice‐ocean model (CIOM) with tidal and parameterized wave mixing to investigate several important physical processes. The simulated circulation pattern in the deep basin is relatively stable, cyclonic, and has little seasonal change. The Bering Slope Current is estimated at 5 Sv and the Kamchatka Current at 20 Sv. The modeled volume transports through the Aleutian passes compared reasonably well with observations. It is confirmed that subtidal clockwise circulation around St. George and St. Paul islands are driven by tidal rectification. The simulation results show that wind‐wave mixing and tidal stirring are the main factors controlling the formation of the upper and the bottom mixed layers, respectively. The mechanism of thermocline and the cold pool (summer minimum‐temperature water) formation in the middle shelf are investigated in depth. The CIOM reproduces the cold winter‐convective water in the middle shelf that forms the bottom cold pool, which persists throughout the summer until sea surface cooling and strong wind mixing in fall, leading to an unstable vertical water column and eventually to vertically well‐mixed water in the winter. Sensitivity experiments show that tidal and wind‐wave mixing are two important factors in accurately estimating the volume of the cold pool, which is the ideal marine habitat for cold water species.
Two types of precipitation particle distribution in convective cells accompanying a Baiu frontal rainband around Okinawa Island, Japan
Authors: Oue M. , Uyeda H. , Shusse Y.
Published: January 2010

Polarimetric radar variables and ground‐based raindrop size distributions (DSDs) of two convective cells in a Baiu frontal rainband over the Okinawa region were analyzed to clarify the precipitation particle distributions in convective cells with low echo top heights. One cell existed in the stratiform rain zone, and the other was in the convective rain zone of the rainband. Both cells had echo top (30 dBZ) heights of approximately 5.5 km above sea level, with large radar reflectivity (Zh) greater than 50 dBZ in each core. For the cell in the stratiform rain zone, polarimetric variables indicated that small raindrops predominated; differential reflectivity (ZDR) was smaller than 1.5 dB, and the correlation coefficient (ρhv) was greater than 0.98 with large Zh (≥40 dBZ). The DSD showed high number densities of small raindrops with diameters of 1–2 mm. For the other cell, polarimetric variables indicated the presence of large raindrops; ZDR greater than 1.5 dB and ρhv smaller than 0.98 predominated in large Zh (≥40 dBZ). The DSD for this cell showed lower number densities of raindrops with diameters of 1–2 mm and higher number densities of raindrops exceeding 3 mm. The significance of these distributions was confirmed by the ZDR and ρhv for 25 cells in the stratiform rain zone and for 28 cells in the convective rain zone. It is notable that different precipitation particle distributions in convective cells were found in the stratiform and convective rain zones of a Baiu frontal rainband with common characteristics of low echo top heights and large Zh.
Functional interaction between Smad3 and S100A4 (metastatin-1) for TGF-β-mediated cancer cell invasiveness
Authors: Matsuura Isao , Lai Chen-Yu , Chiang Keng-Nan
Published: January 2010

TGF-β (transforming growth factor-β) induces a cytostatic response in most normal cell types. In cancer cells, however, it often promotes metastasis, and its high expression is correlated with poor prognosis. In the present study, we show that S100A4, a metastasis-associated protein, also called metastatin-1, can physically and functionally interact with Smad3, an important mediator of TGF-β signalling. In agreement with its known property, S100A4 binds to Smad3 in a Ca2+-dependent manner. The S100A4-binding site is located in the N-terminal region of Smad3. S100A4 can potentiate transcriptional activity of Smad3 and the related Smad2. When exogenously expressed in MCF10CA1a.cl1, an MCF10-derived breast cancer cell line, S100A4 increases TGF-β-induced MMP-9 (matrix metalloproteinase-9) expression. On the other hand, depletion of S100A4 by siRNA (small interfering RNA) from the MDA-MB231 cell line results in attenuation of MMP-9 induction by TGF-β. Consistent with these observations, S100A4 increases cell invasion ability induced by TGF-β in MCF10CA1a.cl1 cells, and depletion of the protein in MDA-MB-231 cells inhibits it. Because expression of both S100A4 and TGF-β is highly elevated in many types of malignant tumours, S100A4 and Smad3 may co-operatively increase metastatic activity of some types of cancer cells.
Physical interaction between the histone acetyl transferase Tip60 and the DNA double-strand breaks sensor MRN complex
Authors: Chailleux Catherine , Tyteca Sandrine , Papin Christophe , Boudsocq François , Puget Nadine , Courilleau Céline , Grigoriev Mikhaïl , Canitrot Yvan , Trouche Didier
Published: January 2010

Chromatin modifications and chromatin-modifying enzymes are believed to play a major role in the process of DNA repair. The histone acetyl transferase Tip60 is physically recruited to DNA DSBs (double-strand breaks) where it mediates histone acetylation. In the present study, we show, using a reporter system in mammalian cells, that Tip60 expression is required for homology-driven repair, strongly suggesting that Tip60 participates in DNA DSB repair through homologous recombination. Moreover, Tip60 depletion inhibits the formation of Rad50 foci following ionizing radiation, indicating that Tip60 expression is necessary for the recruitment of the DNA damage sensor MRN (Mre11–Rad50–Nbs1) complex to DNA DSBs. Moreover, we found that endogenous Tip60 physically interacts with endogenous MRN proteins in a complex which is distinct from the classical Tip60 complex. Taken together, our results describe a physical link between a DNA damage sensor and a histone-modifying enzyme, and provide important new insights into the role and mechanism of action of Tip60 in the process of DNA DSB repair.
The Ig-like domain of human GM-CSF receptor α plays a critical role in cytokine binding and receptor activation
Authors: Mirza Shamaruh , Walker Andrew , Chen Jinglong , Murphy James M. , Young Ian G.
Published: January 2010

GM-CSF (granulocyte/macrophage colony-stimulating factor) is an important mediator of inducible haemopoiesis and inflammation, and has a critical role in the function of alveolar macrophages. Its clinical applications include the mobilization of haemopoietic progenitors, and a role as an immune stimulant and vaccine adjuvant in cancer patients. GM-CSF signals via a specific α receptor (GM-CSFRα) and the shared hβc (human common β-subunit). The present study has investigated the role of the Ig-like domain of GM-CSFRα in GM-CSF binding and signalling. Deletion of the Ig-like domain abolished direct GM-CSF binding and decreased growth signalling in the presence of hβc. To locate the specific residues in the Ig-like domain of GM-CSFRα involved in GM-CSF binding, a structural alignment was made with a related receptor, IL-13Rα1 (interleukin-13 receptor α1), whose structure and mode of interaction with its ligand has recently been elucidated. Mutagenesis of candidate residues in the predicted region of interaction identified Val51 and Cys60 as having critical roles in binding to the α receptor, with Arg54 and Leu55 also being important. High-affinity binding in the presence of hβc was strongly affected by mutation of Cys60 and was also reduced by mutation of Val51, Arg54 and Leu55. Of the four key residues, growth signalling was most severely affected by mutation of Cys60. The results indicate a previously unrecognized role for the Ig-like domain, and in particular Cys60, of GM-CSFRα in the binding of GM-CSF and subsequent activation of cellular signalling.
Versatile roles for myosin Va in dense core vesicle biogenesis and function
Authors: Kögel Tanja , Bittins Claudia Margarethe , Rudolf Rüdiger , Gerdes Hans-Hermann
Published: January 2010

The motor protein myosin Va is involved in multiple successive steps in the development of dense-core vesicles, such as in the membrane remodelling during their maturation, their transport along actin filaments and the regulation of their exocytosis. In the present paper, we summarize the current knowledge on the roles of myosin Va in the different steps of dense-core vesicle biogenesis and exocytosis, and compare findings obtained from different cell types and experimental systems.
Progeria, the nucleolus and farnesyltransferase inhibitors
Authors: Mehta Ishita S. , Bridger Joanna M. , Kill Ian R.
Published: January 2010

HGPS (Hutchinson–Gilford progeria syndrome) is a rare genetic disease affecting children causing them to age and die prematurely. The disease is typically due to a point mutation in the coding sequence for the nuclear intermediate-type filament protein lamin A and gives rise to a dominant-negative splice variant named progerin. Accumulation of progerin within nuclei causes disruption to nuclear structure, causes and premature replicative senescence and increases apoptosis. Now it appears that accumulation of progerin may have more widespread effects than previously thought since the demonstration that the presence and distribution of some nucleolar proteins are also adversely affected in progeria cells. One of the major breakthroughs both in the lamin field and for this syndrome is that many of the cellular defects observed in HGPS patient cells and model systems can be restored after treatment with a class of compounds known as FTIs (farnesyltransferase inhibitors). Indeed, it is demonstrated that FTI-277 is able to completely restore nucleolar antigen localization in treated progeria cells. This is encouraging news for the HGPS patients who are currently undergoing clinical trials with FTI treatment.
Devices based on random conduction with in plane gates: A possibility for three-dimensional integration
Authors: Pennelli Giovanni
Published: January 2010

Electrical conduction in chaotic media near the percolation threshold is investigated by means of Monte Carlo techniques. The main target is to demonstrate the possibility of modulating the conduction of a chaotic film by means of lateral gate electrodes fabricated in the plane of the film. Exponential variations in the conductivity due to the modification of random paths in the chaotic film can be exploited for the realization of devices with high on/off ratio. In this work it is demonstrated that despite the chaotic conduction driven by charge hopping between localized sites, an almost deterministic behavior can be obtained for suitable site concentrations. Transistors based on this concept could be realized on different layers, on the same substrate, with technologies similar to those actually used for conventional integrated circuits: this would make possible an effective three-dimensional integration of devices and circuits.
Real-time in situ nanoclustering during initial stages of artificial aging of Al–Cu alloys
Authors: Zatsepin Nadia A. , Dilanian Ruben A. , Nikulin Andrei Y. , Gao Xiang , Muddle Barry C. , Matveev Victor N. , Sakata Osami
Published: January 2010

We report an experimental demonstration of real-time in situ x-ray diffraction investigations of clustering and dynamic strain in early stages of nanoparticle growth in Al–Cu alloys. Simulations involving a simplified model of local strain are well correlated with the x-ray diffraction data, suggesting a redistribution of point defects and the formation of nanoscale clusters in the bulk material. A modal, representative nanoparticle size is determined subsequent to the final stage of artificial aging. Such investigations are imperative for the understanding, and ultimately the control, of nanoparticle nucleation and growth in this technologically important alloy.
Ring polymer molecular dynamics beyond the linear response regime: Excess electron injection and trapping in liquids
Authors: Menzeleev Artur R. , Miller Thomas F.
Published: January 2010

Ring polymer molecular dynamics (RPMD) is used to directly simulate the injection and relaxation of excess electrons into supercritical helium fluid and ambient liquid water. A method for modulating the initial energy of the excess electron in the RPMD model is presented and used to study both low-energy (cold) and high-energy (hot) electron injections. For cold injection into both solvents, the RPMD model recovers electronically adiabatic dynamics with the excess electron in its ground state, whereas for hot electron injection, the model predicts slower relaxation dynamics associated with electronic transitions between solvent cavities. The analysis of solvent dynamics during electron localization reveals the formation of an outgoing solvent compression wave in helium that travels for over 2 nm and the delayed formation of water solvation shells on the timescale of 300 fs. Various system-size effects that are intrinsic to the simulation of excess electron injection are discussed. Comparison of the RPMD simulations with previous mixed quantum-classical dynamics simulations finds general agreement for both the mechanisms and timescales for electron localization, although the electron localization dynamics in the RPMD model is essentially completed within 400 fs in helium and 150 fs in water.
Accessibility and Urban Development: A Grid-Based Comparative Statistical Analysis of Dutch Cities
Authors: Borzacchiello Maria Teresa , Nijkamp Peter , Koomen Eric
Published: January 2010

Accessibility has become a key issue in modern urban planning. This paper aims to identify the impact of differences in spatial accessibility on the development of the built environment in cities. Using a few simple accessibility indicators, it tries to map out in a quantitative way the detailed implications of accessibility conditions for built-up areas, on the basis of a 25 m × 25 m grid cell approach. The statistical tool used here is logistic regression, followed by a GIS representation of the empirical results for four Dutch cities: Amsterdam, The Hague, Rotterdam, and Utrecht.
A Qualitative GIS Approach to Mapping Urban Neighborhoods with Children to Promote Physical Activity and Child-Friendly Community Planning
Authors: Wridt Pamela
Published: January 2010

As the obesity epidemic in children increases, it is important to consider the role of neighborhoods in supporting children's physical activity and healthy development, especially in low-income communities where obesity levels among children are higher than for their middle-income counterparts. I present a participatory and qualitative GIS approach to mapping children's own perceptions and use of their neighborhood for physical activity with ten and eleven year-olds growing up in a diverse low-income community in Denver, CO. Girls walk shorter distances to and use different types of community spaces for play and recreation from boys, some of which is explained by the differing environmental-socialization approaches employed by parents and carers. Children's perceptions of risk align spatially with features of the built environment, but do not correlate with reported crime. Results illustrate the utility of qualitative spatial analysis to understand relationships between children's perception, the built environment, and social factors that shape children's active transport, leisure, and recreation in their neighborhood. Children's local knowledge should be valued and solicited in community-level health and planning interventions to promote physical activity.
Estimating the Influence of the Neighbourhood in the Development of Residential Areas in the Netherlands
Authors: de Nijs Ton , Pebesma Edzer
Published: January 2010

Land-use models have been developed for predicting future land-use patterns. We describe a logistic regression model for residential development in the Netherlands that takes the neighbourhood effects of land use and infrastructure into account. Hereto, a new methodology was developed, single parameter impact estimation, for estimating the influence of land use and infrastructure in the neighbourhood on residential developments. The model also incorporates initial land use and a set of policy-related and suitability-related variables. In essence, the neighbourhood effects typically simulated with cellular automata-based land-use models have been integrated into a logistic regression model. The model was calibrated and validated on historic land-use developments in the Netherlands. On the basis of the model, residential areas develop preferably at the fringe of the city, on agricultural land in the neighbourhood of residential areas. The probability of residential development depends on the cluster size of the land-use categories. Large clusters of allotments, cemeteries, or sports fields are relatively attractive for residential development, while forest, nature, and industrial areas become more attractive when present in small clusters.
Hemispheric differences in processing of vocalizations depend on early experience
Authors: Phan Mimi L. , Vicario David S.
Published: January 2010

An intriguing phenomenon in the neurobiology of language is lateralization: the dominant role of one hemisphere in a particular function. Lateralization is not exclusive to language because lateral differences are observed in other sensory modalities, behaviors, and animal species. Despite much scientific attention, the function of lateralization, its possible dependence on experience, and the functional implications of such dependence have yet to be clearly determined. We have explored the role of early experience in the development of lateralized sensory processing in the brain, using the songbird model of vocal learning. By controlling exposure to natural vocalizations (through isolation, song tutoring, and muting), we manipulated the postnatal auditory environment of developing zebra finches, and then assessed effects on hemispheric specialization for communication sounds in adulthood. Using bilateral multielectrode recordings from a forebrain auditory area known to selectively process species-specific vocalizations, we found that auditory responses to species-typical songs and long calls, in both male and female birds, were stronger in the right hemisphere than in the left, and that right-side responses adapted more rapidly to stimulus repetition. We describe specific instances, particularly in males, where these lateral differences show an influence of auditory experience with song and/or the bird’s own voice during development.
A circadian clock in
Saccharomyces cerevisiae
Authors: Eelderink-Chen Zheng , Mazzotta Gabriella , Sturre Marcel , Bosman Jasper , Roenneberg Till , Merrow Martha
Published: January 2010

Circadian timing is a fundamental biological process, underlying cellular physiology in animals, plants, fungi, and cyanobacteria. Circadian clocks organize gene expression, metabolism, and behavior such that they occur at specific times of day. The biological clocks that orchestrate these daily changes confer a survival advantage and dominate daily behavior, for example, waking us in the morning and helping us to sleep at night. The molecular mechanism of circadian clocks has been sketched out in genetic model systems from prokaryotes to humans, revealing a combination of transcriptional and posttranscriptional pathways, but the clock mechanism is far from solved. Although
Saccharomyces cerevisiae
is among the most powerful genetic experimental systems and, as such, could greatly contribute to our understanding of cellular timing, it still remains absent from the repertoire of circadian model organisms. Here, we use continuous cultures of yeast, establishing conditions that reveal characteristic clock properties similar to those described in other species. Our results show that metabolism in yeast shows systematic circadian entrainment, responding to cycle length and zeitgeber (stimulus) strength, and a (heavily damped) free running rhythm. Furthermore, the clock is obvious in a standard, haploid, auxotrophic strain, opening the door for rapid progress into cellular clock mechanisms.
Rapid evolution of stability and productivity at the origin of a microbial mutualism
Authors: Hillesland Kristina L. , Stahl David A.
Published: January 2010

Mutualistic interactions are taxonomically and functionally diverse. Despite their ubiquity, however, the basic ecological and evolutionary processes underlying their origin and maintenance are poorly understood. A major reason for this is the lack of an experimentally tractable model system. We examine the evolution of an experimentally imposed obligate mutualism between sulfate-reducing and methanogenic microorganisms that have no known history of previous interaction. Twenty-four independent pairings (cocultures) of the bacteriumDesulfovibrio vulgarisand the archaeonMethanococcus maripaludiswere established and followed for 300 community doublings in two environments, one allowing for the development of a heterogeneous distribution of resources and the other not. Evolved cocultures grew up to 80% faster and were up to 30% more productive (biomass yield per mole of substrate) than the ancestors. The evolutionary process was marked by periods of significant instability leading to extinction of two of the cocultures, but it resulted in more stable, efficient, and productive mutualisms for most replicated pairings. Comparisons of evolved cocultures with those assembled from one evolved mutualist and one ancestral mutualist showed that evolution of both species contributed to improved productivity. Surprisingly, however, overall improvements in growth rate and yield were less than the sum of the individual contributions, suggesting antagonistic interactions between mutations from the coevolved populations. Physical constraints on the transfer of metabolites in the evolution environment affected the evolution ofM. maripaludis, but not ofD. vulgaris. Together, these results demonstrate that challenges can imperil nascent obligate mutualisms and demonstrate the evolutionary responses that enable their persistence and future evolution.
A remorin protein interacts with symbiotic receptors and regulates bacterial infection
Authors: Lefebvre Benoit , Timmers Ton , Mbengue Malick , Moreau Sandra , Hervé Christine , Tóth Katalin , Bittencourt-Silvestre Joana , Klaus Dörte , Deslandes Laurent , Godiard Laurence , Murray Jeremy D. , Udvardi Michael K. , Raffaele Sylvain , Mongrand Sebastien , Cullimore Julie , Gamas Pascal , Niebel Andreas , Ott Thomas
Published: January 2010

Remorin proteins have been hypothesized to play important roles during cellular signal transduction processes. Induction of some members of this multigene family has been reported during biotic interactions. However, no roles during host-bacteria interactions have been assigned to remorin proteins until now. We used root nodule symbiosis between
Medicago truncatula
and
Sinorhizobium meliloti
to study the roles of a remorin that is specifically induced during nodulation. Here we show that this oligomeric remorin protein attaches to the host plasma membrane surrounding the bacteria and controls infection and release of rhizobia into the host cytoplasm. It interacts with the core set of symbiotic receptors that are essential for perception of bacterial signaling molecules, and thus might represent a plant-specific scaffolding protein.
Mask use, hand hygiene, and seasonal influenza-like illness among young adults: A randomized intervention trial
Authors: Aiello Allison E. , Murray Genevra F. , Perez Vanessa , Coulborn Rebecca M. , Davis Brian M. , Uddin Monica , Shay David K. , Waterman Stephen H. , Monto Arnold S.
Published: January 2010

Background . During the influenza A(H1N1) pandemic, antiviral prescribing was limited, vaccines were not available early, and the effectiveness of nonpharmaceutical interventions (NPIs) was uncertain. Our study examined whether use of face masks and hand hygiene reduced the incidence of influenza-like illness (ILI).

Methods . A randomized intervention trial involving 1437 young adults living in university residence halls during the 2006–2007 influenza season was designed. Residence halls were randomly assigned to 1 of 3 groups—face mask use, face masks with hand hygiene, or control— for 6 weeks. Generalized models estimated rate ratios for clinically diagnosed or survey-reported ILI weekly and cumulatively.

Results . We observed significant reductions in ILI during weeks 4–6 in the mask and hand hygiene group, compared with the control group, ranging from 35% (confidence interval [CI], 9%–53%) to 51% (CI, 13%–73%), after adjusting for vaccination and other covariates. Face mask use alone showed a similar reduction in ILI compared with the control group, but adjusted estimates were not statistically significant. Neither face mask use and hand hygiene nor face mask use alone was associated with a significant reduction in the rate of ILI cumulatively.

Conclusions . These findings suggest that face masks and hand hygiene may reduce respiratory illnesses in shared living settings and mitigate the impact of the influenza A(H1N1) pandemic.

Trial Registration . ClinicalTrials.gov identifier: NCT00490633.
The Green Tiger
Authors: Goldoftas Barbara
Published: January 2010

The Philippines was once famous for its reef-ringed islands, white beaches, and lush forests. In less than a half-century, these were degraded by deforestation, over-fishing, and destructive fishing. This rapid harvest of ecologically and economically critical natural resources brought droughts, deadly flash floods, and the collapse of fisheries and the timber industry. Regional rural economies weakened, sending hundreds of thousands of ecological refugees to cities where they overwhelmed the urban infrastructure. Today, the Philippines stands as an example of the profound and sweeping consequences of environmental degradation. This book documents this tragic trajectory, but the story it tells is not one of hopelessness and inevitable defeat. The book traces the struggle for natural resource conservation in the Philippines, from isolated villages to large cities, illustrating innovative ways that conservation and economic growth can effectively coexist. It describes how individuals and institutions at all levels of Philippine society have responded to the environmental change, and gives background information on environmental policy. It argues that recent initiatives to conserve or rehabilitate resources — by local and national government, non-governmental organizations, or communities — can be an important part of sustainable development and nation-building. It also questions whether western environmentalism, which can pit environmental protection against economic need, is appropriate for developing countries. The book offers in-depth case studies of environmental governance and sets the consequences of rapid industrialization and environmental change in their historical context.
The Language of Law School
Authors: Mertz Elizabeth
Published: January 2010

Anyone who has attended law school knows that it invokes an important intellectual transformation, frequently referred to as “learning to think like a lawyer”. This process, which forces students to think and talk in radically new and toward different ways about conflicts, is directed by professors in the course of their lectures and examinations, and conducted via spoken and written language. This book delves into that legal language to reveal the complexities of how this process takes place. The book bases its linguistic study on tape recordings from first year Contracts courses in eight different law schools. The book discusses how these schools employ the Socratic method between teacher and student, forcing the student to shift away from moral and emotional terms in thinking about conflict, toward frameworks of legal authority instead. This move away from moral frameworks is key, the book says, arguing that it represents an underlying world view at the core not just of law education, but for better or worse, of the entire U.S. legal system—which, while providing a useful source of legitimacy and a means to process conflict, fails to deal systematically with aspects of fairness and social justice. The latter part of the study shows how differences in race and gender makeup among law students and professors can subtly alter this process.
Mainstream Style
Authors: Haynes Bruce
Published: January 2010

Several factors can make one identify which style of music is being played, including continuous and strong vibrato, long- line phrasing, lack of beat hierarchy, unyielding tempos, unstressed dissonances, or rigidly equal 16th notes. There was a time, after World War II, when this was the only style. This was the way it was done, except for a few outdated codgers, still holding out for the old Romantic sentimentalism. Modern style has its place, and for a very limited repertoire of Stravinsky and the Neoclassicists, it is the most appropriate style around. The problem is that it has spread to musics where it acts as a restraint and a damper, since its practices are so different from either Eloquent or Romantic styles. This chapter discusses modernism and the Modern style of music, performance practices of Romantic style compared with Modern style, and the use of vibrato. Period style is compared with Modern style, and the Strait style of music is described.
Perpetual Revolution
Authors: Haynes Bruce
Published: January 2010

There are probably limits to how far we can go today in giving up our tastes, and they no doubt vary depending on the individual case. The most difficult examples may be the historical markers: historical techniques that have no equivalents in Modern style and are therefore unfamiliar; the messa di voce, for instance, dynamic inflection, phrasing based on gestures rather than “long-lines,” articulation syllables on woodwinds, and flattement (finger vibrato). These are not the subtle mannerisms that can overlay a basic modern technique: on the contrary, they negate many things musicians learn in Modern style, and they are immediately conspicuous in performance, probably even to non-musicians. To incorporate these techniques convincingly means rethinking the music because at first they often seem illogical, distasteful, and unmusical. This chapter discusses the illusion of an unbroken performing style from Mozart to contemporary times, Historically Inspired Performance (HIP) movement versus Romanticism, HIP versus classical music, perpetual revolution in music, and the pursuit of authenticity.
Islamic law as common law: Power, culture, and the reconfiguration of legal taxonomies
Authors: ROSEN LAWRENCE
Published: January 2010

Taxonomies of law often include a category called religious law. This chapter argues that this is useless, as is the Orientalist assumption that all law can be understood through the concepts generated by European legal systems. In fact, Islamic law is best seen as a kind of common law system, and a revised taxonomy of legal systems is offered within which Islamic law may now be placed.
Statistical Physics of Spin Glasses and Information Processing
Authors: Nishimori Hidetoshi
Published: January 2010

Spin glasses are magnetic materials with strong disorder. Statistical mechanics has been a powerful tool to theoretically analyse various unique properties of spin glasses. A number of new analytical techniques have been developed to establish a theory of spin glasses. Surprisingly, these techniques have offered new tools and viewpoints for the understanding of information processing problems, including neural networks, error-correcting codes, image restoration, and optimization problems. A vast, interdisciplinary field has consequently been developing between physics and information, or more specifically, between the statistical physics of spin glasses and several important aspects of information processing tasks. This book provides a broad overview of this new field. It also contains detailed descriptions of the theory of spin glasses.