bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tidal Influences on Cluster Dwarf Evolution
Authors: Smith R. , Davies J. I. , Nelson A. 
Published: February 2008

AbstractUsing N-Body/Treecode, SPH simulations, including a self regulating Star Formation-feedback model, the influence of cluster tidal forces on infalling dwarf irregulars is investigated. Results suggest that an encounter with the cluster potential can disrupt a rotating disk causing morphological transformation of the gaseous component, resulting in an enhancement of star formation rates (SFRs) of up to an order of magnitude.
The Chemical Enrichment of the Diffuse Gas in the Outer Galaxy and the Abundance Gradient of the Milky Way
Authors: Song Limin , Tripp Todd M. , Bowen David V. , Sembach Kenneth R. 
Published: February 2008

AbstractUsing data from HST/STIS (Hubble Space Telescope / Space Telescope Imaging Spectrograph) and FUSE (Far Ultraviolet Spectroscopic Explorer) toward two QSOs, H1821+643 and HS0624+6907, we find that the overall metallicity of the Galactic “Outer Arm” is Z=0.3−0.5 Z⊙ with underabundant nitrogen and little depletion by dust. The results are consistent with those based on H II region measurements in the outer galaxy and provide additional constrains on models of the Galactic abundance gradient and Milky Way (MW) chemical evolution. The lower metallicity observed in the outer galaxy is consistent with abundance patterns observed in higher redshift damped Lyα absorbers (DLAs) extrapolated to z=0. The slow metallicity evolution of DLAs could be due to the larger cross sections of the outer regions of galaxies combined with the observed metallicity gradients.
The ALFA Zone of Avoidance Survey: Results from the Precursor Observations
Authors: Springob C. M. , Henning P. A. , Catinella B. , Day F. , Minchin R. , Momjian E. , Koribalski B. , Masters K. L. , Muller E. , Pantoja C. , Putman M. , Rosenberg J. L. , Schneider S. , Staveley-Smith L. 
Published: February 2008

AbstractThe Arecibo L-band Feed Array Zone of Avoidance Survey (ALFA ZOA) will map 1350-1800 deg2 at low Galactic latitude, providing HI spectra for galaxies in regions of the sky where our knowledge of local large scale structure remains incomplete, owing to obscuration from dust and high stellar confusion near the Galactic plane. Because of these effects, a substantial fraction of the galaxies detected in the survey will have no optical or infrared counterparts. However, near infrared follow up observations of ALFA ZOA sources found in regions of lowest obscuration could reveal whether some of these sources could be objects in which little or no star formation has taken place (“dark galaxies”). We present here the results of ALFA ZOA precursor observations on two patches of sky totaling 140 deg2 (near l = 40°, and l = 192°). We have measured HI parameters for detections from these observations, and cross-correlated with the NASA/IPAC Extragalactic Database (NED). A significant fraction of the objects have never been detected at any wavelength. For those galaxies that have been previously detected, a significant fraction have no previously known redshift, and no previous HI detection.
ALFALFA in the Leo Region: Looking for Missing Satellites in HI
Authors: Stierwalt Sabrina 
Published: February 2008

AbstractThe location of two nearby galaxy groups within ~20 Mpc in the Leo region allows for a detailed study of low-mass galaxies. A catalog of HI line detections in Leo (9h36m < α < 11h36m, +8° < δ < +16°) has been made from the blind HI survey ALFALFA. More sensitive single-pixel Arecibo observations targeted Leo dwarf candidates noted optically by Karachentsev et al. 2004 (K04) to determine group members and allow for a comparison of HI and optically-selected samples. This presentation highlights the differences between the two samples and the significant contribution blind HI surveys can make to the missing satellites problem.
The Northern HIPASS Optical/IR Catalogue (NOIRCAT)
Authors: Wong O. Ivy , Webster Rachel L. , Waugh Meryl , Kilborn Virginia A. , Staveley-Smith Lister 
Published: February 2008

AbstractWe present the Northern HIPASS Optical/Infrared Catalogue (NOIRCAT), an optical/near-infrared counterpart catalogue for the Northern HIPASS catalogue (NHICAT). Of the 1002 sources in NHICAT, 655 (66%) have optical counterparts with matching optical velocities. A further 87 sources have optical counterparts with matching velocities from previous radio emission line surveys. Assuming a dark galaxy to be an isolated HI source with no detectable stars, no candidate dark galaxies have been confirmed.
The MareNostrum Galaxy Formation Simulation Project
Authors: Yepes G. , Martinez-Vaquero L. , Khalatyan A. , Gottlöber S. , Hoeft M. , Teyssier R. 
Published: February 2008

AbstractThe goal of this unprecedented large scale numerical project is to run state-of-the-art cosmological simulations of galaxy formation with two different numerical techniques: the particle based code GADGET-2 and the Eulerian AMR code RAMSES, starting from the same initial conditions. Both codes are fully parallel with MPI and can make efficient use of thousands of processors of the Marenostrum Supercomputer in Barcelona, where these two numerical experiments are being run.
Constrained Simulations of the Local Universe
Authors: Yepes G. , Martinez-Vaquero L. , Hoffman Y. , Gottlöber S. , Klypin A. 
Published: February 2008

AbstractWe have studied the formation of the Local Universe using constrained cosmological simulations. To this end we use the observed local mass and velocity distributions to generate the initial density field. A variety of N-body simulations with different box sizes and resolutions have been done so far. The largest structures, such as Coma, Virgo and the Local Supercluster are reproduced with high accuracy. We have also been able to obtain a representation of the Local Group with unprecedented accuracy and resolution. From these simulations we are studying in detail the dynamics of the dark matter in our neighborhood. The next step will be to include baryons and study in detail the galaxy formation in our local universe.
New Episodes of Volcanism at Kilauea Volcano, Hawaii
Authors: Poland Michael , Miklius Asta , Orr Tim , Sutton Jeff , Thornber Carl , Wilson David 
Published: February 2008

Mid‐2007 was a time of intense activity at Kilauea Volcano, Hawaii (see Figure 1). In June, the long‐lived Pu'u 'Ō'ō—Kupaianaha eruption, a dual‐vent system along the east rift zone (ERZ) that has been erupting since 1983 [Heliker et al., 2003], paused due to the outbreak of a new vent farther up the rift (see Figure 2). The Pu'u 'Ō'ō vent collapsed following that activity, and the resulting reorganization of the magma plumbing system led to the formation of a second new eruptive vent 2 kilometers downrift of Pu'u 'Ō'ō.These events were well documented by geological, geophysical, and geochemical monitoring. This article summarizes results from these monitoring efforts and interprets the changes that have occurred at Kilauea since June 2007.
Converting Raw Data Into Ecologically Meaningful Products: Data‐Model Assimilation in Ecology: Techniques and Applications; Norman, Oklahoma, 22–24 October 2007
Authors: Hui Dafeng , Luo Yiqi , Schimel David , Clark James S. , Hastings Alan , Ogle Kiona , Williams Mathew 
Published: February 2008

A U.S. National Science Foundation workshop brought together more than 40 researchers from different disciplines to discuss applications of data assimilation techniques in ecology, define major scientific questions to be addressed, and identify future research challenges.The field of ecology has become a data‐rich enterprise, due largely to rapid development of measurement sensors and long‐term accumulation of data from research networks. With the implementation of the National Ecological Observatory Network (NEON), a network with different kinds of sensors at many locations over the nation, large volumes of ecological data will be generated every day. There will be an unprecedented demand to convert the massive raw data into ecologically meaningful products using data assimilation techniques.
McNutt Receives 2007 Maurice Ewing Medal
Authors: Watts Anthony B. , McNutt Marcia K. 
Published: February 2008

It is a great honor for me to have the opportunity to deliver this citation for Marcia K. McNutt, the 2007 recipient of AGU's Maurice Ewing Medal. Marcia has made a significant contribution to our understanding of the structure of oceanic lithosphere, served in leadership roles in the marine scientific community, and instigated new directions and technologies for ocean exploration.Marcia received her undergraduate degree in physics and studied for the Ph.D. with Bob Parker and the late Bill Menard at the Scripps Institution of Oceanography. Her thesis led to two seminal papers on oceanic and continental isostasy. The first showed that flexure due to a young volcanic load could influence the subsidence and uplift history of nearby, preexisting volcanoes. This hypothesis, which explains why some seamounts and oceanic islands show uplift rather than subsidence, has had wide implications for basin development and sea level change. The second used 3‐D spectral methods of analyzing topography and gravity data to argue that the Australian lithosphere responds to loads as a relatively strong structure at short time scales and a weak one at long geological times. This method is now widely used and is at the center of current debates concerning the rheology and strength of continental lithosphere.
AGU Revises Position Statement on Climate Change
Authors: Von Holle Kate 
Published: February 2008

Earlier this month, Eos published three of the four position statements that were adopted by the AGU Council at its 14 December 2007 meeting. Last week, AGU released the fourth statement, “Human Impacts on Climate.” AGU formulates and maintains a number of position statements that reflect the concerns of the Union, none of which extends beyond the range of available geophysical data or the norms of legitimate scientific debate.The climate statement has been extensively revised from its original 2003 version, largely because of the significant amount of scientific data that have become available in the past 4 years. The statement also has been substantiated by the release last year of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report.
Science News for the U.S. Hispanic Audience
Authors: Showstack Randy 
Published: February 2008

A science and health news service targeted toward the U.S. Hispanic community was launched on 23 January. ConCiencia, billed as the first Spanish‐language science newswire service in the United States, provides free weekly news feeds to media targeting the U.S. Hispanic population. The news feeds, available to Spanish‐language newspapers and radio stations, include newspaper features, radio segments, and online news content.ConCiencia science advisor Bob Russell said it is critical to provide Hispanic media with an ongoing source of high‐quality science news that meets the needs and interests of Hispanics. He noted that “Latinos currently achieve lower‐than‐average math and science scores in public schools and are significantly underrepresented in science and engineering professions.”
Applying Rock Physics to Natural Hazards: Euro‐Conference of Rock Physics and Geomechanics on Natural Hazards: Thermo‐Hydro‐Mechanical Processes in Rocks; Erice, Italy, 25–30 September 2007
Authors: Vinciguerra Sergio , Bernabe Yves 
Published: February 2008

Natural hazards events such as earthquakes or volcanic eruptions involve activation of coupled thermo‐hydro‐chemo‐mechanical processes in rocks. A conference sponsored by the Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV), the French Centre National de la Recherche Scientifique (CNRS), and Exxon Mobil was held in Erice, Italy, to explore how rock physics experiments and models can help scientists understand natural hazards mechanisms, and to foster cross‐ disciplinary collaborations.The largest part of the conference was devoted to questions related to rock failure and earthquake source mechanisms. Several presentations showed that despite the huge reduction in scale, laboratory experiments sometimes display phenomena strikingly similar to field observations. For example, new very high slip‐rate friction experiments show significantly higher fault weakening than previously observed at the laboratory scale. These exploratory experiments may provide new insights into the mutual interactions of frictional shear failure, heat production, and fluid or melt lubrication. Another study revealed that tremor‐like events are generated in laboratory samples during melt propagation in cracks or dehydration of hydrated minerals, providing physical constraints to the open debate on the origin of volcanic and non‐volcanic deep tremors.
Summer School Seeks to Better Link Atmosphere and Ocean Convection Studies: Fundamental Issues in Geophysical and Environmental Fluid Mechanics: Atmosphere‐Ocean Convection in Climate Dynamics; Valsavaranche, Italy, 18–27 June 2007
Authors: Yano Jun‐Ichi , Griffiths Ross , Bouruet‐Aubertot Pascale 
Published: February 2008

To provide Ph.D. students with a coherent overview of the current understanding of atmosphere and ocean convection in the context of global climate modeling, an Alpine summer school was organized in Valsavaranche, Italy, during June 2007. About 50 students from five continents and three islands participated in this unique event. Lectures and class discussions covered topics including asymptotic analyses, computational modeling, field campaigns, and laboratory analogs.The emphasis of the school was on deep convection, the form of convection of greatest importance to global circulation and climate. However, a series of lecturers revealed that atmospheric and oceanographic convection each pose quite different complexities. The presence of water vapor as a minor constituent of the atmosphere substantially alters the thermodynamics, and lecturers discussed how it is necessary to model a water cycle complicated by cloud formation, a variety of ice crystals, precipitation, and reevaporation. Oceanographic convection, on the other hand, is complicated through strong coupling with wind stress forcing, bottom topography, and baroclinic eddies. It still remains a major challenge to identify the various processes governing deep convection in high‐latitude oceans and the tropical atmosphere, and the coupling of this convection with larger‐scale circulation. Parameterization of convection, though clearly essential in climate modeling, is simply too extensively relied upon in both atmosphere and ocean models.
Fiscal Year 2009 U.S. Budget Request Unveiled
Authors: Kumar Mohi , Von Holle Kate 
Published: February 2008

The Bush administration's proposed budget for fiscal year (FY) 2009, released on 4 February, requested roughly US$40 billion for projects that support research in Earth, environmental, space, and energy‐related sciences through the Department of Energy (DOE) Office of Science, NASA, the U.S. National Oceanic and Atmospheric Administration (NOAA), the U.S. National Science Foundation (NSF), the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (EPA). This request is about 4% more than the amount authorized by Congress to support such research in FY 2008.A significant portion of this budget increase is for programs that will address global climate change through advancing energy security and monitoring the Earth's dynamic system as global temperatures rise.
U.S. Geological Survey Budget Cuts Funds for Minerals, Hazards, and Water Programs
Authors: Showstack Randy 
Published: February 2008

The Bush administration's proposed US$968.5 million budget for the U.S. Geological Survey (USGS) for fiscal year (FY) 2009 is a $38 million decrease from the FY 2008 enacted level.The proposed budget also includes some increases for high‐priority programs. Funding includes an $8.2 million net increase for a water census that would be the first U.S.‐wide assessment of water availability and human and environmental water use and an increase of $7 million to support the U.S. Department of Interior's Ocean and Coastal Frontiers Initiative, which will acquire key ocean health data while also providing objective scientific data to evaluate U.N. Law of the Sea claims made by other nations.
Nitrogen fixation by phyllosphere bacteria associated with higher plants and their colonizing epiphytes of a tropical lowland rainforest of Costa Rica
Authors: Fürnkranz Michael , Wanek Wolfgang , Richter Andreas , Abell Guy , Rasche Frank , Sessitsch Angela 
Published: February 2008

Abstract
Leaf surfaces (phyllospheres) have been shown to provide appropriate conditions for colonization by microorganisms including diazotrophic bacteria that are able to fix atmospheric nitrogen (N2). In this study, we determined leaf-associated N2 fixation of a range of rainforest plants in Costa Rica, under different environmental conditions, by tracing biomass N incorporation from 15N2. N2-fixing bacterial communities of the plant species Carludovica drudei, Grias cauliflora and Costus laevis were investigated in more detail by analysis of the nifH gene and leaf-associated bacteria were identified by 16S rRNA gene analysis. N2 fixation rates varied among plant species, their growth sites (different microclimatic conditions) and light exposure. Leaf-associated diazotrophic bacterial communities detected on C. drudei and C. laevis were mainly composed of cyanobacteria (Nostoc spp.), whereas on the leaves of G. cauliflora γ-proteobacteria were dominant in addition to cyanobacteria. The complexity of diazotrophic communities on leaves was not correlated with N2 fixation activity. 16S rRNA gene sequence analysis suggested the presence of complex microbial communities in association with leaves, however, cyanobacteria showed only low abundance. Our findings suggest that cyanobacteria as well as γ-proteobacteria associated with leaf-colonizing epiphytes may provide significant nitrogen input into this rainforest ecosystem.
Influence of industrial contamination on mobile genetic elements: class 1 integron abundance and gene cassette structure in aquatic bacterial communities
Authors: Wright Meredith S , Baker-Austin Craig , Lindell Angela H , Stepanauskas Ramunas , Stokes Hatch W , McArthur J Vaun 
Published: February 2008

Abstract
The acquisition of new genetic material via horizontal gene transfer allows bacteria to rapidly evolve. One key to estimating the contribution of horizontal gene transfer to bacterial evolution is to quantify the abundance of mobile genetic elements (MGEs) in bacterial communities under varying degrees of selective pressure. We quantified class 1 integrase (intI1) gene abundance in total community DNA extracted from contaminated and reference riverine and estuarine microhabitats, and in metal- or antibiotic-amended freshwater microcosms. The intI1 gene was more abundant in all contaminant-exposed communities indicating that relative gene transfer potential is higher in these communities. A second key to assessing the contributions of MGEs to bacterial evolution is to examine the structure and function of the MGE-associated gene pool. We determined that the gene cassette pool is a novel and diverse resource available for bacterial acquisition, but that contamination has no discernible effect on cassette richness. Gene cassette profiles were more similar within sites than among sites, yet bacterial community profiles were not, suggesting that selective pressures can shape the structure of the gene cassette pool. Of the 46 sequenced gene cassette products, 37 were novel sequences, while the 9 gene cassettes with similarity to database sequences were primarily to hypothetical proteins. That class 1 integrons are ubiquitous and abundant in environmental bacterial communities indicates that this group of MGEs can play a substantial role in the acquisition of a diverse array of gene cassettes beyond their demonstrated impact in mediating multidrug resistance in clinical bacteria.
On ARS-interacting multifunctional protein p18
Authors: Deineko Viktor 
Published: February 2008

AbstractNine aminoacyl-tRNA synthetases with three auxiliary components are forming a multisynthetase complex which is essential component of protein biosynthesis machinery. The smallest auxiliary component p18 takes part in biosynthesis channeling. It is also a regulator of p53 and has tumor suppressing function. Particular structure of this protein is still unknown. Here methods of structural bioinformatics were applied to generate a model of p18 spatial structure suitable for further research. The structure was created using homology modeling. DNA-binding residues of p18 were also derived both from raw sequence and from three-dimensional structure model.
Exploring a first-principles-based model for zooplankton respiration
Authors: Packard Ted T. , Gómez May 
Published: February 2008

AbstractPackard, T. T., and Gómez, M. 2008. Exploring a first-principles-based model for zooplankton respiration. – ICES Journal of Marine Science, 65: 371–378. Oxygen consumption (R) is caused by the respiratory electron transfer system (ETS), not biomass. ETS is ubiquitous in zooplankton, determines the level of potential respiration (Φ), and is the enzyme system that ultimately oxidizes the products of food digestion, makes ATP, and consumes O2. Current respiration hypotheses are based on allometric relationships between R and biomass. The most accepted version at constant temperature (T) is R = i0M0.75, where i0 is a constant. We argue that, for zooplankton, a Φ-based, O2-consuming algorithm is more consistent with the cause of respiration. Our point: although biomass is related to respiration, the first-principles cause of respiration is ETS, because it controls O2 consumption. Biomass itself is indirectly related to respiration, because it packages the ETS. Consequently, we propose bypassing the packaging and modelling respiration from ETS and hence Φ. This Φ is regulated by T, according to Arrhenius theory, and by specific reactants (S) that sustain the redox reactions of O2 consumption, according to Michaelis–Menten kinetics. Our model not only describes respiration over a large range of body sizes but also explains and accurately predicts respiration on short time-scales. At constant temperature, our model takes the form: where Ea is the Arrhenius activation energy, Rg, the gas constant, and Km, the Michaelis–Menten constant.
Ctf1, a transcriptional activator of cutinase and lipase genes in Fusarium oxysporum is dispensable for virulence
Authors: ROCHA ANA LILIA MARTÍNEZ , DI PIETRO ANTONIO , RUIZ‐ROLDÁN CARMEN , RONCERO M. ISABEL G. 
Published: February 2008

SUMMARYCutinolytic enzymes are secreted by fungal pathogens attacking the aerial parts of the plant, to facilitate penetration of the outermost cuticular barrier of the host. The role of cutinases in soil‐borne root pathogens has not been studied thus far. Here we report the characterization of the zinc finger transcription factor Ctf1 from the vascular wilt fungus Fusarium oxysporum, a functional orthologue of CTF1α that controls expression of cutinase genes and virulence in the pea stem pathogen Fusarium solani f. sp. pisi. Mutants carrying a Δctf1 loss‐of‐function allele grown on inducing substrates failed to activate extracellular cutinolytic activity and expression of the cut1 and lip1 genes, encoding a putative cutinase and lipase, respectively, whereas strains harbouring a ctf1C allele in which the ctf1 coding region was fused to the strong constitutive Aspergillus nidulans gpdA promoter showed increased induction of cutinase activity and gene expression. These results suggest that F. oxysporum Ctf1 mediates expression of genes involved in fatty acid hydrolysis. However, expression of lip1 during root infection was not dependent on Ctf1, and virulence of the ctf1 mutants on tomato plants and fruits was indistinguishable from that of the wild‐type. Thus, in contrast to the stem pathogen F. solani, Ctf1 is not essential for virulence in the root pathogen F. oxysporum.