65 research outputs found
Is the observed high-frequency radio luminosity distribution of QSOs bimodal?
The distribution of QSO radio luminosities has long been debated in the
literature. Some argue that it is a bimodal distribution, implying that there
are two separate QSO populations (normally referred to as 'radio-loud' and
'radio-quiet'), while others claim it forms a more continuous distribution
characteristic of a single population. We use deep observations at 20 GHz to
investigate whether the distribution is bimodal at high radio frequencies.
Carrying out this study at high radio frequencies has an advantage over
previous studies as the radio emission comes predominantly from the core of the
AGN, hence probes the most recent activity. Studies carried out at lower
frequencies are dominated by the large scale lobes where the emission is built
up over longer timescales (10^7-10^8 yrs), thereby confusing the sample. Our
sample comprises 874 X-ray selected QSOs that were observed as part of the 6dF
Galaxy Survey. Of these, 40% were detected down to a 3 sigma detection limit of
0.2-0.5 mJy.
No evidence of bimodality is seen in either the 20 GHz luminosity
distribution or in the distribution of the R_20 parameter: the ratio of the
radio to optical luminosities traditionally used to classify objects as being
either radio-loud or radio-quiet. Previous results have claimed that at low
radio luminosities, star formation processes can dominate the radio emission
observed in QSOs. We attempt to investigate these claims by stacking the
undetected sources at 20 GHz and discuss the limitations in carrying out this
analysis. However, if the radio emission was solely due to star formation
processes, we calculate that this corresponds to star formation rates ranging
from ~10 solar masses/yr to ~2300 solar masses/yr.Comment: 13 pages, 11 figures. Accepted for publication in Ap
Familial Mediterranean fever, Inflammation and Nephrotic Syndrome: Fibrillary Glomerulopathy and the M680I Missense Mutation
BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by inflammatory serositis (fever, peritonitis, synovitis and pleuritis). The gene locus responsible for FMF was identified in 1992 and localized to the short arm of chromosome 16. In 1997, a specific FMF gene locus, MEFV, was discovered to encode for a protein, pyrin that mediates inflammation. To date, more than forty missense mutations are known to exist. The diversity of mutations identified has provided insight into the variability of clinical presentation and disease progression. CASE REPORT: We report an individual heterozygous for the M680I gene mutation with a clinical diagnosis of FMF using the Tel-Hashomer criteria. Subsequently, the patient developed nephrotic syndrome with biopsy-confirmed fibrillary glomerulonephritis (FGN). Further diagnostic studies were unremarkable with clinical workup negative for amyloidosis or other secondary causes of nephrotic syndrome. DISCUSSION: Individuals with FMF are at greater risk for developing nephrotic syndrome. The most serious etiology is amyloidosis (AA variant) with renal involvement, ultimately progressing to end-stage renal disease. Other known renal diseases in the FMF population include IgA nephropathy, IgM nephropathy, Henoch-Schönlein purpura as well as polyarteritis nodosa. CONCLUSION: To our knowledge, this is the first association between FMF and the M680I mutation later complicated by nephrotic syndrome and fibrillary glomerulonephritis
Fetal Demise and Failed Antibody Therapy During Zika Virus Infection of Pregnant Macaques
Zika virus (ZIKV) infection of pregnant women is associated with pathologic complications of fetal development. Here, we infect pregnant rhesus macaques (Macaca mulatta) with a minimally passaged ZIKV isolate from Rio de Janeiro, where a high rate of fetal development complications was observed. The infection of pregnant macaques with this virus results in maternal viremia, virus crossing into the amniotic fluid (AF), and in utero fetal deaths. We also treated three additional ZIKV-infected pregnant macaques with a cocktail of ZIKV-neutralizing human monoclonal antibodies (nmAbs) at peak viremia. While the nmAbs can be effective in clearing the virus from the maternal sera of treated monkeys, it is not sufficient to clear ZIKV from AF. Our report suggests that ZIKV from Brazil causes fetal demise in non-human primates (NHPs) without additional mutations or confounding co-factors. Treatment with a neutralizing anti-ZIKV nmAb cocktail is insufficient to fully stop vertical transmission
Teleconsultation Improves Primary Care Clinicians’ Confidence about Caring for HIV
BackgroundTelemedicine can facilitate communication between primary care clinicians and specialists. Generalists who use telemedicine for consultation (teleconsultation) may be able to practice more independently and reduce the number of formal referrals to specialists. In the United States, a federally funded human immunodeficiency virus (HIV) teleconsultation service (HIV Warmline) offers clinicians live telephone access to HIV specialists; however, its impact on clinicians' self-perceived clinical competence and referral rates has not been studied.ObjectiveTo determine if primary care clinicians who used the HIV Warmline felt more capable of managing HIV in their own practices.DesignOnline survey.ParticipantsPrimary care physicians and mid-level practitioners who used the HIV Warmline for teleconsultation between 1/2008 and 3/2010.Main measuresParticipants compared the HIV Warmline to other methods of obtaining HIV clinical support, and then rated its impact on their confidence in their HIV skills and their referral patterns.Key resultsRespondents (N = 191, 59% response rate) found the HIV Warmline to be quicker (65%), more applicable (70%), and more trustworthy (57%) than other sources of HIV information. After using the HIV Warmline, 90% had improved confidence about caring for HIV, 67% stated it changed the way they managed HIV, and 74% were able to avoid referring patients to specialists. All valued the availability of live, free consultation.ConclusionsPrimary care clinicians who called the HIV Warmline reported increased confidence in their HIV care and less need to refer patients to specialists. Teleconsultation may be a powerful tool to help consolidate HIV care in the primary care setting, and could be adapted for use with a variety of other medical conditions. The direct impact of teleconsultation on actual referral rates, quality of care and clinical outcomes needs to be studied
Familial Mediterranean fever, Inflammation and Nephrotic Syndrome: Fibrillary Glomerulopathy and the M680I Missense Mutation
Abstract Background Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by inflammatory serositis (fever, peritonitis, synovitis and pleuritis). The gene locus responsible for FMF was identified in 1992 and localized to the short arm of chromosome 16. In 1997, a specific FMF gene locus, MEFV, was discovered to encode for a protein, pyrin that mediates inflammation. To date, more than forty missense mutations are known to exist. The diversity of mutations identified has provided insight into the variability of clinical presentation and disease progression. Case Report We report an individual heterozygous for the M680I gene mutation with a clinical diagnosis of FMF using the Tel-Hashomer criteria. Subsequently, the patient developed nephrotic syndrome with biopsy-confirmed fibrillary glomerulonephritis (FGN). Further diagnostic studies were unremarkable with clinical workup negative for amyloidosis or other secondary causes of nephrotic syndrome. Discussion Individuals with FMF are at greater risk for developing nephrotic syndrome. The most serious etiology is amyloidosis (AA variant) with renal involvement, ultimately progressing to end-stage renal disease. Other known renal diseases in the FMF population include IgA nephropathy, IgM nephropathy, Henoch-Schönlein purpura as well as polyarteritis nodosa. Conclusion To our knowledge, this is the first association between FMF and the M680I mutation later complicated by nephrotic syndrome and fibrillary glomerulonephritis.</p
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