392 research outputs found
The energy distribution of relativistic electrons in the kilo-parsec scale jet of M87 with Chandra
The X-ray emission from the jets in Active Galactic Nuclei (AGN) carries
important information on the distributions of relativistic electrons and
magnetic fields on large scales. We reanalyze archival Chandra observations on
the jet of M87 from 2000 to 2016 with a total exposure of 1460 kiloseconds to
explore the X-ray emission characteristics along the jet. We investigate the
variability behaviours of the nucleus and the inner jet component HST-1, and
confirm indications for day-scale X-ray variability in the nucleus
contemporaneous to the 2010 high TeV gamma-ray state. HST-1 shows a general
decline in X-ray flux over the last few years consistent with its synchrotron
interpretation. We extract the X-ray spectra for the nucleus and all knots in
the jet, showing that they are compatible with a single power-law within the
X-ray band. There are indications of the resultant X-ray photon index to
exhibit a trend, with slight but significant index variations ranging from
(e.g. in knot D) to (in the outer knots F, A, and
B). When viewed in a multi-wavelength context, a more complex situation is
arising. Fitting the radio to X-ray spectral energy distributions (SEDs)
assuming a synchrotron origin, we show that a broken power-law electron
spectrum with break energy around TeV allows a
satisfactorily description of the multi-band SEDs for most of the knots.
However, in the case of knots B, C and D we find indications that an additional
high energy component is needed to adequately reproduce the broadband SEDs. We
discuss the implications and suggest that a stratified jet model may account
for the differences.Comment: accepted for publication in A&
Concert recording 2020-01-18
[Track 1]. Sonata for two violins in E minor, Op. 3, No 5 I. Allegro ma poco II. Gavotte - andante grazioso III. Presto / Jean-Marie Leclair -- [Track 2]. From eight pieces for violin and cello, Op. 39 Prelude Intermezza Gavotte [Track 3]. Berceuse [Track 4]. Canzonetta [Track 5]. Scherzo / Reinhold Gliere -- [Track 6]. Piano quintet in A minor, Op. 84 I. Moderato - allegro [Track 7]. II. Adagio [Track 8]. III. Andante - allegro / Edward Elgar
Effect of Plant Population Density and Methods of Weed Control on The Yield of Pepper ( Capsicum annum L.) in Northeastern Nigeria
Field experiments were conducted at Yola and Garkida in Adamawa State,
North-Eastern Nigeria during the 2017 rainy season. In the Yola
location the experiment was conducted at the Teaching and Research Farm
of the Department of Crop Production and Horticulture, Modibbo Adama
University of Technology, Yola, and in Garkida it was conducted at
Garkida village in Gombi Local Government Area of Adamawa State. The
experiment was designed to study the effect of plant population density
and methods of weed control on the yield of pepper (Capsicum annum L.).
The treatments consist of three spacings, 25 x 30cm, 35 x 40cm and 45 x
50cm with four (4) different herbicides rates (No herbicide,
pyrithiobac sodium 65.5kg a.i/ha, pendimethalin 1kg a.i/ha +
pyrithiobac sodium 65.5kg a.i/ha and Haloxyfop 108g a.i/ha + hand hoe
weeding. The experimental design was a split-plot design replicated
three times. Spacing was assigned to the main plot while methods of
weed control as subplots. Parameters measured were weed density, number
of pepper fruits per plot, and fruit yield per hectare. All data were
subjected to analysis of variance (ANOVA) appropriate to the split-plot
design. The results of the experiment showed that herbicide pyrthiobac
sodium 65.5kg a.i/ha recorded the highest number of fruit per plot of
72.4 while herbicide haloxyfop 108g a.i/ha followed by hand weeding
recorded the least number of fruits of 50.1. The result of the
experiment shows that there was a significant effect on spacing in both
locations. Concerning yield per hectare spacing 25x30cm obtained the
highest yield per hectare of 945kg in Garkida, while the least was from
the Yola location which recorded 537kg. It was concluded that pepper
yield depends on the proper spacing and proper use of herbicide which
will suppress weed and increase yield significantly
Diffuse gamma-ray emission toward the massive star-forming region, W40
We report the detection of high-energy gamma-ray signal towards the young
star-forming region, W40. Using 10-year Pass 8 data from the Fermi Large Area
Telescope (Fermi-LAT), we extracted an extended gamma-ray excess region with a
significance of about 18sigma. The radiation has a spectrum with a photon index
of 2.49 +/- 0.01. The spatial correlation with the ionized gas content favors
the hadronic origin of the gamma-ray emission. The total cosmic-ray (CR) proton
energy in the gamma-ray production region is estimated to be the order of 10^47
erg. However, this could be a small fraction of the total energy released in
cosmic rays (CRs) by local accelerators, presumably by massive stars, over the
lifetime of the system. If so, W40, together with earlier detections of
gamma-rays from Cygnus cocoon, Westerlund 1, Westerlund 2, NGC 3603, and 30 Dor
C, supports the hypothesis that young star clusters are effective CR factories.
The unique aspect of this result is that the gamma-ray emission is detected,
for the first time, from a stellar cluster itself, rather than from the
surrounding "cocoons".Comment: 8 pages, 7 figures, accepted for publication in A&
New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk
To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P\u3c5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk
Changes in serum biomarker profiles after percutaneous mitral valve repair with the MitraClip system
BACKGROUND
Mitral regurgitation (MR) is one of the most common valvular diseases. Percu-taneous mitral valve repair with the MitraClipTM system is a novel percutaneous mitral valve repair (PMVR) technique for high-surgical-risk patients. However, the effect of PMVR on cir-culating cardiac or inflammatory biomarkers and their association with individual functional, echocardiographic and clinical outcomes is poorly investigated.
METHODS
A group of 144 patients with functional or degenerative MR (age, 75 ± 11 years; 41% females) underwent PMVR with the MitraClip system at the University Heart Center Zu-rich. Serum biomarkers as N-terminal pro-B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP) and creatinine were obtained from venous sampling at baseline and follow-up of 3-6 months.
RESULTS
Median NT-proBNP decreased insignificantly from 2,942 (IQR 1,596-5,722) to 2,739 (IQR 1,440-4,296) ng/L, p = 0.21. NT-proBNP changes did not correlate with baseline left ventricular (LV) ejection fraction or LV dimensions, with New York Heart Association class on follow-up, or with clinical events on follow-up. CRP levels reached a peak on the third postoperative day at 34.0 mg/L with a subsequent slow decrease over the ensuing days.
CONCLUSIONS
Despite successful PMVR, NT-proBNP remain fairly unchanged on follow-up and changes in NT-proBNP levels are poor predictors of functional improvement or clinical outcome after MitraClip treatment
Changes in serum biomarker profiles after percutaneous mitral valve repair with the MitraClip system
Background: Mitral regurgitation (MR) is one of the most common valvular diseases. PercuÂtaneous mitral valve repair with the MitraClipTM system is a novel percutaneous mitral valve repair (PMVR) technique for high-surgical-risk patients. However, the effect of PMVR on cirÂculating cardiac or inflammatory biomarkers and their association with individual functional, echocardiographic and clinical outcomes is poorly investigated.
Methods: A group of 144 patients with functional or degenerative MR (age, 75 ± 11 years; 41% females) underwent PMVR with the MitraClip system at the University Heart Center ZuÂrich. Serum biomarkers as N-terminal pro-B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP) and creatinine were obtained from venous sampling at baseline and follow-up of 3–6 months.
Results: Median NT-proBNP decreased insignificantly from 2,942 (IQR 1,596–5,722) to 2,739 (IQR 1,440–4,296) ng/L, p = 0.21. NT-proBNP changes did not correlate with baseline left ventricular (LV) ejection fraction or LV dimensions, with New York Heart Association class on follow-up, or with clinical events on follow-up. CRP levels reached a peak on the third postoperative day at 34.0 mg/L with a subsequent slow decrease over the ensuing days.
Conclusions: Despite successful PMVR, NT-proBNP remain fairly unchanged on follow-up and changes in NT-proBNP levels are poor predictors of functional improvement or clinical outcome after MitraClip treatment
Metabolic heterogeneity in adrenocortical carcinoma impacts patient outcomes
Spatially resolved metabolomics enables the investigation of tumoral metabolites in situ. Inter- and intratumor heterogeneity are key factors associated with patient outcomes. Adrenocortical carcinoma (ACC) is an exceedingly rare tumor associated with poor survival. Its clinical prognosis is highly variable, but the contributions of tumor metabolic heterogeneity have not been investigated thus far to our knowledge. An in-depth understanding of tumor heterogeneity requires molecular feature-based identification of tumor subpopulations associated with tumor aggressiveness. Here, using spatial metabolomics by high-mass resolution MALDI Fourier transform ion cyclotron resonance mass spectrometry imaging, we assessed metabolic heterogeneity by de novo discovery of metabolic subpopulations and Simpson's diversity index. After identification of tumor subpopulations in 72 patients with ACC, we additionally performed a comparison with 25 tissue sections of normal adrenal cortex to identify their common and unique metabolic subpopulations. We observed variability of ACC tumor heterogeneity and correlation of high metabolic heterogeneity with worse clinical outcome. Moreover, we identified tumor subpopulations that served as independent prognostic factors and, furthermore, discovered 4 associated anticancer drug action pathways. Our research may facilitate comprehensive understanding of the biological implications of tumor subpopulations in ACC and showed that metabolic heterogeneity might impact chemotherapy
Biomarkers of rapid chronic kidney disease progression in type 2 diabetes.
Here we evaluated the performance of a large set of serum biomarkers for the prediction of rapid progression of chronic kidney disease (CKD) in patients with type 2 diabetes. We used a case-control design nested within a prospective cohort of patients with baseline eGFR 30-60 ml/min per 1.73 m(2). Within a 3.5-year period of Go-DARTS study patients, 154 had over a 40% eGFR decline and 153 controls maintained over 95% of baseline eGFR. A total of 207 serum biomarkers were measured and logistic regression was used with forward selection to choose a subset that were maximized on top of clinical variables including age, gender, hemoglobin A1c, eGFR, and albuminuria. Nested cross-validation determined the best number of biomarkers to retain and evaluate for predictive performance. Ultimately, 30 biomarkers showed significant associations with rapid progression and adjusted for clinical characteristics. A panel of 14 biomarkers increased the area under the ROC curve from 0.706 (clinical data alone) to 0.868. Biomarkers selected included fibroblast growth factor-21, the symmetric to asymmetric dimethylarginine ratio, β2-microglobulin, C16-acylcarnitine, and kidney injury molecule-1. Use of more extensive clinical data including prebaseline eGFR slope improved prediction but to a lesser extent than biomarkers (area under the ROC curve of 0.793). Thus we identified several novel associations of biomarkers with CKD progression and the utility of a small panel of biomarkers to improve prediction.We acknowledge all the SUMMIT partners (http://www.imi-summit.eu/) for their assistance with this project. This work was funded by the Innovative Medicine Initiative under grant agreement no. IMI/115006 (the SUMMIT consortium) and the Go-DARTS cohort was funded by the Chief Scientists Office Scotland.This is the accepted manuscript of a paper published in Kidney International (Looker et al., Kidney International, 2015 doi: 10.1038/ki.2015.199). The final version is available at http://dx.doi.org/10.1038/ki.2015.19
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