101 research outputs found
Extragalactic Relativistic Jets and Nuclear Regions in Galaxies
Past years have brought an increasingly wider recognition of the ubiquity of
relativistic outflows (jets) in galactic nuclei, which has turned jets into an
effective tool for investigating the physics of nuclear regions in galaxies. A
brief summary is given here of recent results from studies of jets and nuclear
regions in several active galaxies with prominent outflows.Comment: 5 pages; contribution to ESO Astrophysical Symposia, "Relativistic
Astrophysics and Cosmology", eds. B. Aschenbach, V. Burwitz, G. Hasinger, B.
Leibundgut (Springer: Heidelberg 2006
Active Galactic Nuclei at the Crossroads of Astrophysics
Over the last five decades, AGN studies have produced a number of spectacular
examples of synergies and multifaceted approaches in astrophysics. The field of
AGN research now spans the entire spectral range and covers more than twelve
orders of magnitude in the spatial and temporal domains. The next generation of
astrophysical facilities will open up new possibilities for AGN studies,
especially in the areas of high-resolution and high-fidelity imaging and
spectroscopy of nuclear regions in the X-ray, optical, and radio bands. These
studies will address in detail a number of critical issues in AGN research such
as processes in the immediate vicinity of supermassive black holes, physical
conditions of broad-line and narrow-line regions, formation and evolution of
accretion disks and relativistic outflows, and the connection between nuclear
activity and galaxy evolution.Comment: 16 pages, 5 figures; review contribution; "Exploring the Cosmic
Frontier: Astrophysical Instruments for the 21st Century", ESO Astrophysical
Symposia Serie
Scale issues in soil moisture modelling: problems and prospects
Soil moisture storage is an important component of the hydrological cycle and plays a key role in land-surface-atmosphere interaction. The soil-moisture storage equation in this study considers precipitation as an input and soil moisture as a residual term for runoff and evapotranspiration. A number of models have been developed to estimate soil moisture storage and the components of the soil-moisture storage equation. A detailed discussion of the impli cation of the scale of application of these models reports that it is not possible to extrapolate processes and their estimates from the small to the large scale. It is also noted that physically based models for small-scale applications are sufficiently detailed to reproduce land-surface- atmosphere interactions. On the other hand, models for large-scale applications oversimplify the processes. Recently developed physically based models for large-scale applications can only be applied to limited uses because of data restrictions and the problems associated with land surface characterization. It is reported that remote sensing can play an important role in over coming the problems related to the unavailability of data and the land surface characterization of large-scale applications of these physically based models when estimating soil moisture storage.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Rho GTPase function in flies: insights from a developmental and organismal perspective.
Morphogenesis is a key event in the development of a multicellular organism and is reliant on coordinated transcriptional and signal transduction events. To establish the segmented body plan that underlies much of metazoan development, individual cells and groups of cells must respond to exogenous signals with complex movements and shape changes. One class of proteins that plays a pivotal role in the interpretation of extracellular cues into cellular behavior is the Rho family of small GTPases. These molecular switches are essential components of a growing number of signaling pathways, many of which regulate actin cytoskeletal remodeling. Much of our understanding of Rho biology has come from work done in cell culture. More recently, the fruit fly Drosophila melanogaster has emerged as an excellent genetic system for the study of these proteins in a developmental and organismal context. Studies in flies have greatly enhanced our understanding of pathways involving Rho GTPases and their roles in development
Track D Social Science, Human Rights and Political Science
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd
Cave-Obligate Biodiversity on the Campus of Sewanee: The University of the South, Franklin County, Tennessee
The southern Cumberland Plateau in Tennessee and Alabama has the greatest diversity of cave-obligate animals in the United States. The University of the South in Franklin County, TN is one of the largest private landholders on the southern Cumberland Plateau. Its 13,000-acre campus has more than 30 caves and is underlain by more than 14 km of horizontal passageways. We examined the biodiversity of cave animals on the campus at the species level and at the genetic level. Through a survey of seven caves on the campus, we identified 24 cave-obligate species, including two new county records. This total accounts for half of the cave-obligate species reported for Franklin County. For our genetic analysis, we selected six diverse taxa (two millipedes, a beetle, a fly, an aquatic isopod, and a spider) that were collected from multiple caves, and compared their mitochondrial cytochrome oxidase I gene sequences. Across the six taxa we found: (1) low genetic diversity within caves (mean nucleotide diversity within caves across all taxa: 0.25%), (2) high genetic divergence between caves (divergence between caves within taxa ranged from 2.5%â10.9%, with two exceptions), and (3) little evidence for gene flow between caves (FST between caves within taxa \u3e 0.57, with one exception). Thus, the campus supports tremendous species diversity, and even more remarkable genetic diversity within those species on a small geographic scale (no studied caves were \u3e7 km apart). The divergence between cave populations and lack of gene flow between them that we observed across a range of taxa highlight the importance of cave conservation on a regional scale
Management of adverse effects of Peg-IFN and ribavirin therapy for hepatitis C
HCV infects approximately 2-3% of the global population and is a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with Peg-IFN in combination with ribavirin can eradicate HCV infection in 40-90% of patients; however, a major barrier to treatment uptake and delivery is the association of this therapy with frequent and, at times, serious adverse effects. Recognition and effective management of these adverse effects are critical components of the successful treatment of chronic HCV infection. In clinical trials, approximately 10-15% of patients discontinue Peg-IFN and ribavirin therapy due to adverse effects; however, in clinical practice, the rate of treatment discontinuation has been reported to be substantially higher. The off-target effect of Peg-IFN and ribavirin impacts most, if not all, organ systems; the most common adverse effects are hematologic, dermatologic, neurologic, immunologic, gastrointestinal, pulmonary, cardiovascular, and ocular. Regional and global variability exists in the nature of these adverse effects and the strategies employed to ameliorate their impact. This article provides a comprehensive literature review that systematically describes the adverse effects of Peg-IFN-ι and ribavirin on various organ systems and, more importantly, recommends consensus approaches to managing those effects. Š 2011 Macmillan Publishers Limited. All rights reserved
Management of adverse effects of Peg-IFN and ribavirin therapy for hepatitis C
HCV infects approximately 2-3% of the global population and is a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with Peg-IFN in combination with ribavirin can eradicate HCV infection in 40-90% of patients; however, a major barrier to treatment uptake and delivery is the association of this therapy with frequent and, at times, serious adverse effects. Recognition and effective management of these adverse effects are critical components of the successful treatment of chronic HCV infection. In clinical trials, approximately 10-15% of patients discontinue Peg-IFN and ribavirin therapy due to adverse effects; however, in clinical practice, the rate of treatment discontinuation has been reported to be substantially higher. The off-target effect of Peg-IFN and ribavirin impacts most, if not all, organ systems; the most common adverse effects are hematologic, dermatologic, neurologic, immunologic, gastrointestinal, pulmonary, cardiovascular, and ocular. Regional and global variability exists in the nature of these adverse effects and the strategies employed to ameliorate their impact. This article provides a comprehensive literature review that systematically describes the adverse effects of Peg-IFN-ι and ribavirin on various organ systems and, more importantly, recommends consensus approaches to managing those effects. Š 2011 Macmillan Publishers Limited. All rights reserved
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