bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring with benthic fauna in Italian coastal lagoons: new tools for new prospects
Authors: Munari Cristina , Warwick Richard M. , Mistri Michele 
Published: November 2008

Abstract
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

Abstract
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

Abstract
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

Abstract
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

AbstractNumerical 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

AbstractWe 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

AbstractWe 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

AbstractIn 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

AbstractWe 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

AbstractIn 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

AbstractWe 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

AbstractThe 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

AbstractThe 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

AbstractWe 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

AbstractWe 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

AbstractWe 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

AbstractWe 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

AbstractNumerical 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

AbstractSuppose 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.