418 research outputs found

    A search for non-thermal radio emission from jets of massive young stellar objects

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    Massive young stellar objects (MYSOs) have recently been shown to drive jets whose particles can interact with either the magnetic fields of the jet or ambient medium to emit non-thermal radiation. We report a search for non-thermal radio emission from a sample of 15 MYSOs to establish the prevalence of the emission in the objects. We used their spectra across the L, C, and Q bands along with spectral index maps to characterize their emission. We find that about 50 perā€‰cent of the sources show evidence for non-thermal emission with 40 perā€‰cent showing clear non-thermal lobes, especially sources of higher bolometric luminosity. The common or IRAS names of the sources that manifest non-thermal lobes are V645Cyg, IRAS 22134+5834, NGC 7538 IRS 9, IRAS 23262 + 640, AFGL 402d, and AFGL 490. All the central cores of the sources are thermal with corresponding mass-loss rates that lie in the range of āˆ¼3 Ɨ 10āˆ’7 to 7Ɨ10āˆ’6MāŠ™yrāˆ’1ā . Given the presence of non-thermal lobes in some of the sources and the evidence of non-thermal emission from some spectral index maps, it seems that magnetic fields play a significant role in the jets of massive protostars. Also noted is that some of the sources show evidence of binarity and variability

    Re-Assembly of the Genome of Francisella tularensis Subsp. holarctica OSU18

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    Francisella tularensis is a highly infectious human intracellular pathogen that is the causative agent of tularemia. It occurs in several major subtypes, including the live vaccine strain holarctica (type B). F. tularensis is classified as category A biodefense agent in part because a relatively small number of organisms can cause severe illness. Three complete genomes of subspecies holarctica have been sequenced and deposited in public archives, of which OSU18 was the first and the only strain for which a scientific publication has appeared [1]. We re-assembled the OSU18 strain using both de novo and comparative assembly techniques, and found that the published sequence has two large inversion mis-assemblies. We generated a corrected assembly of the entire genome along with detailed information on the placement of individual reads within the assembly. This assembly will provide a more accurate basis for future comparative studies of this pathogen

    A summer heat wave decreases the immunocompetence of the mesograzer, Idotea baltica

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    Extreme events associated with global change will impose increasing stress on coastal organisms. How strong biological interactions such as the hostā€“parasite arms-race are modulated by environmental change is largely unknown. The immune system of invertebrates, in particular phagocytosis and phenoloxidase activity response are key defence mechanisms against parasites, yet they may be sensitive to environmental perturbations. We here simulated an extreme event that mimicked the European heat wave in 2003 to investigate the effect of environmental change on the immunocompetence of the mesograzer Idotea baltica. Unlike earlier studies, our experiment aimed at simulation of the natural situation as closely as possible by using long acclimation, a slow increase in temperature and a natural community setting including the animalsā€™ providence with natural food sources (Zostera marina and Fucus vesiculosus). Our results demonstrate that a simulated heat wave results in decreased immunocompetence of the mesograzer Idotea baltica, in particular a drop of phagocytosis by 50%. This suggests that global change has the potential to significantly affect hostā€“parasite interactions

    ATLASGAL - properties of compact H II regions and their natal clumps

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    We present a complete sample of molecular clumps containing compact and ultracompact HII (UC HII) regions between ā„“ = 10Ā° and 60Ā° and |b| < 1Ā°, identified by combining the APEX Telescope Large Area Survey ofthe Galaxy submm and CORNISH radio continuum surveys with visual examination ofarchival infrared data. Our sample is complete to optically thin, compact and UC HII regions driven by a zero-age main-sequence star of spectral type B0 or earlier embedded within a 1000M clump. In total we identify 213 compact and UC HII regions, associated with 170 clumps. Unambiguous kinematic distances are derived for these clumps and used to estimate their masses and physical sizes, as well as the Lyman continuum fluxes and sizes of their embedded HII regions. We find a clear lower envelope for the surface density of molecular clumps hosting massive star formation of 0.05 g cm, which is consistent with a similar sample of clumps associated with 6.7 GHz masers. The mass of the most massive embedded starsis closely correlated with the mass of their natal clump. Young B stars appearto be significantly more luminous in the ultraviolet than predicted by current stellar atmosphere models. The properties of clumps associated with compact and UC HII regions are very similar to those associated with 6.7 GHz methanol masers and we speculate that there is little evolution in the structure of the molecular clumps between these two phases. Finally, we identifya significant peak in the surface density of compact and UC HII-regions associated with the W49A star-forming complex, noting that this complex is truly one of the most massive and intense regions of star formation in the Galaxy. Ā© 2013 The Authors, Published by Oxford University Press on behalf of the Royal Astronomical Society

    Second breast cancers in a Tuscan case series: characteristics, prognosis, and predictors of survival

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    Little is known about long-term outcomes following a second breast cancer diagnosis. We describe the epidemiology, characteristics and prognosis of second breast cancers in an Italian cohort. We identified women with two breast cancer diagnoses from 24ā€‰278 histology records at a Tuscan breast cancer service between 1980 and 2005, and determined their survival status. Disease-specific survival from second diagnosis was examined using Cox regression analyses. Second cancers were identified in 1044 women with a median age of 60 years. In all 455 were ipsilateral relapses and 589 were contralateral cancers. Median time between first and second diagnosis was 63.4 months. The majority of second cancers was small invasive or in situ tumours. Estimated 10-year survival from a second cancer diagnosis was 78%. Survival was poorest when the second cancer was large (HR=2.26) or node-positive (HR=3.43), when the time between the two diagnoses was <5 years (HR=1.45), or when the diagnosis was in an earlier epoch (HR=2.20). Second tumours were more likely to be large or node-positive if the first breast cancer had these features. Prognosis following a second breast cancer in this cohort was generally good. However, large or node-positive second tumours, and shorter intervals between diagnoses were indicators of poorer survival

    The Promise and Challenge of Therapeutic MicroRNA Silencing in Diabetes and Metabolic Diseases

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    MicroRNAs (miRNAs) are small, non-coding, RNA molecules that regulate gene expression. They have a long evolutionary history and are found in plants, viruses, and animals. Although initially discovered in 1993 in Caenorhabditis elegans, they were not appreciated as widespread and abundant gene regulators until the early 2000s. Studies in the last decade have found that miRNAs confer phenotypic robustness in the face of environmental perturbation, may serve as diagnostic and prognostic indicators of disease, underlie the pathobiology of a wide array of complex disorders, and represent compelling therapeutic targets. Pre-clinical studies in animal models have demonstrated that pharmacologic manipulation of miRNAs, mostly in the liver, can modulate metabolic phenotypes and even reverse the course of insulin resistance and diabetes. There is cautious optimism in the field about miRNA-based therapies for diabetes, several of which are already in various stages of clinical trials. This review will highlight both the promise and the most pressing challenges of therapeutic miRNA silencing in diabetes and related conditions

    Read Length and Repeat Resolution: Exploring Prokaryote Genomes Using Next-Generation Sequencing Technologies

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    Background: There are a growing number of next-generation sequencing technologies. At present, the most cost-effective options also produce the shortest reads. However, even for prokaryotes, there is uncertainty concerning the utility of these technologies for the de novo assembly of complete genomes. This reflects an expectation that short reads will be unable to resolve small, but presumably abundant, repeats. Methodology/Principal Findings: Using a simple model of repeat assembly, we develop and test a technique that, for any read length, can estimate the occurrence of unresolvable repeats in a genome, and thus predict the number of gaps that would need to be closed to produce a complete sequence. We apply this technique to 818 prokaryote genome sequences. This provides a quantitative assessment of the relative performance of various lengths. Notably, unpaired reads of only 150nt can reconstruct approximately 50 % of the analysed genomes with fewer than 96 repeat-induced gaps. Nonetheless, there is considerable variation amongst prokaryotes. Some genomes can be assembled to near contiguity using very short reads while others require much longer reads. Conclusions: Given the diversity of prokaryote genomes, a sequencing strategy should be tailored to the organism unde

    Current status and recommendations for biomarkers and biobanking in neurofibromatosis

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    Objective: Clinically validated biomarkers for neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis (SWN) have not been identified to date. The biomarker working group&apos;s goals are to (1) define biomarker needs in NF1, NF2, and SWN; (2) summarize existing data on biomarkers in NF1, NF2, and SWN; (3) outline recommendations for sample collection and biomarker development; and (4) standardize sample collection and methodology protocols where possible to promote comparison between studies by publishing standard operating procedures (SOPs). Methods: The biomarker group reviewed published data on biomarkers in NF1, NF2, and SWN and on biobanking efforts outside these diseases via literature search, defined the need for biomarkers in NF, and developed recommendations in a series of consensus meetings. Results: We describe existing biomarkers in NF and report consensus recommendations for SOP and a minimal clinical dataset to accompany samples derived from patients with NF1, NF2, and SWN in decentralized biobanks. Conclusions: These recommendations are intended to provide clinicians and researchers with a common set of guidelines to collect and store biospecimens and for establishment of biobanks for NF1, NF2, and SWN.N

    Identification of diagnostic serum protein profiles of glioblastoma patients

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    Diagnosis of a glioblastoma (GBM) is triggered by the onset of symptoms and is based on cerebral imaging and histological examination. Serum-based biomarkers may support detection of GBM. Here, we explored serum protein concentrations of GBM patients and used data mining to explore profiles of biomarkers and determine whether these are associated with the clinical status of the patients. Gene and protein expression data for astrocytoma and GBM were used to identify secreted proteins differently expressed in tumors and in normal brain tissues. Tumor expression and serum concentrations of 14 candidate proteins were analyzed for 23 GBM patients and nine healthy subjects. Data-mining methods involving all 14 proteins were used as an initial evaluation step to find clinically informative profiles. Data mining identified a serum protein profile formed by BMP2, HSP70, and CXCL10 that enabled correct assignment to the GBM group with specificity and sensitivity of 89 and 96%, respectively (pĀ <Ā 0.0001, Fischerā€™s exact test). Survival for more than 15Ā months after tumor resection was associated with a profile formed by TSP1, HSP70, and IGFBP3, enabling correct assignment in all cases (pĀ <Ā 0.0001, Fischerā€™s exact test). No correlation was found with tumor size or age of the patient. This study shows that robust serum profiles for GBM may be identified by data mining on the basis of a relatively small study cohort. Profiles of more than one biomarker enable more specific assignment to the GBM and survival group than those based on single proteins, confirming earlier attempts to correlate single markers with cancer. These conceptual findings will be a basis for validation in a larger sample size
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