824 research outputs found
The radio-infrared correlation in galaxies
The radio-infrared correlation was explained as a direct and linear
relationship between star formation and IR emission. However, one fact making
the IR-star formation linkage less obvious is that the IR emission consists of
at least two emission components, cold dust and warm dust. The cold dust
emission may not be directly linked to the young stellar population.
Furthermore, understanding the origin of the radio-IR correlation requires to
discriminate between the two main components of the radio continuum emission,
free-free and synchrotron emission. Here, we present a multi-scale study of the
correlation of IR with both the thermal and non-thermal (synchrotron)
components of the radio continuum emission from the nearby galaxies M33 and
M31.Comment: To appear in Highlights of Astronomy, Volume 15, XXVIIth IAU General
Assembly, August 200
The Local Radio-IR Relation in M51
We observed M51 at three frequencies, 1.4 GHz (20 cm), 4.9 GHz (6 cm), and 8.4 GHz (3.6 cm), with the Very Large Array and the Effelsberg 100 m telescope to obtain the highest quality radio continuum images of a nearby spiral galaxy. These radio data were combined with deconvolved Spitzer IRAC 8 μm and MIPS 24 μm images to search for and investigate local changes in the radio-IR correlation. Utilizing wavelet decomposition, we compare the distribution of the radio and IR emission on spatial scales between 200 pc and 30 kpc. We show that the radio-IR correlation is not uniform across the galactic disk. It presents a complex behavior with local extrema corresponding to various galactic structures, such as complexes of H II regions, spiral arms, and interarm filaments, indicating that the contribution of the thermal and non-thermal radio emission is a strong function of environment. In particular, the relation of the 24 μm and 20 cm emission presents a linear relation within the spiral arms and globally over the galaxy, while it deviates from linearity in the interarm and outer regions as well in the inner region, with two different behaviors: it is sublinear in the interarm and outer region and overlinear in the central 3.5 kpc. Our analysis suggests that the changes in the radio/IR correlation reflect variations of interstellar medium properties between spiral arms and interarm region. The good correlation in the spiral arms implies that 24 μm and 20 cm are tracing recent star formation, while a change in the dust opacity, "Cirrus" contribution to the IR emission and/or the relation between the magnetic field strength and the gas density can explain the different relations found in the interarm, outer, and inner regions
Glycated hemoglobin measurements from dried blood spots: Reliability and relation to results obtained from whole blood samples
Background: Main objective was to measure glycated hemoglobin (HbA1c) in dried blood spots on paper filter and in whole blood samples in diabetic patients to evaluate relationship between two methods and their respective reliability. Methods: The 20�10 μl of venous blood samples of 33 diabetics were blotted onto the filter paper allowed to dry at room temperature and then stored at 25°C and 4°C. HbA1c was measured via the Turbidimetric Inhibition Immunoassay Technique. The relation was evaluated with correlation and linear regression tests using STATA software and SPSS. Agreement between the results obtained from the dried blood spots and others was evaluated using the Bland and Altman. The pitman's permutation test was also employed to compare the difference in variance. Results: A high positive correlation was detected between whole blood samples and dried blood spots stored at 4°C (r2 =0.90) and at 25°C (r2 = 0.95). The Bland and Altman graphs, as well as the Pitman tests, showed statistically significant differences in variability between the values obtained from whole blood samples and those derived from dried spots stored at 4°C (p=0.05) or 25°C (p=0.004). Conclusion: HbA1c measurements from dried blood spots on the filter paper yielded reliable results. That the Hitachi autoanalyzer is available in most countries renders this assay less costly than the High Performance Liquid Chromatography Method (HPLC). In addition, the filter paper method for Immuno-turbidimetric estimations of HbA1c at different temperatures is reliable and may be particularly useful in outpatient diabetes clinic
The Magnetized Disk-Halo Transition Region of M51
An excellent laboratory for studying large scale magnetic fields is the grand
de- sign face-on spiral galaxy M51. Due to wavelength-dependent Faraday
depolarization, linearly polarized synchrotron emission at different radio
frequencies gives a picture of the galaxy at different depths: Observations at
L-band (1-2 GHz) probe the halo region while at C- and X- band (4-8 GHz) the
linearly polarized emission probe the disk region of M51. We present new
observations of M51 using the Karl G. Jansky Very Large Array (VLA) at S-band
(2-4 GHz), where previously no polarization observations existed, to shed new
light on the transition region between the disk and the halo. We discuss a
model of the depolarization of synchrotron radiation in a multilayer
magneto-ionic medium and compare the model predictions to the multi-frequency
polarization data of M51 between 1-8GHz. The new S-band data are essential to
distinguish between different models. Our study shows that the initial model
parameters, i.e. the total reg- ular and turbulent magnetic field strengths in
the disk and halo of M51, need to be adjusted to successfully fit the models to
the data.Comment: 4 Pages, 3 Figures, Conference Proceeding to IAU Focus Meeting 8: New
Insights in Extragalactic Magnetic Field
Occurrence and antimicrobial resistance of emergent Arcobacter spp. isolated from cattle and sheep in Iran
This study is conducted to determine the occurrence and antimicrobial resistance of Arcobacter spp. isolated from clinically healthy food animals. A total of 308 samples from cattle (200) and sheep (108) were collected from Shiraz slaughterhouse, southern Iran to investigate the presence of the important Arcobacter spp. using cultivation and Polymerase Chain Reaction (PCR) methods. Antimicrobial susceptibility of Arcobacter isolates was determined for 18 antibiotics using disk diffusion method. Among 308 samples, 27 (8.7) and 44 (14.28) were positive for the presence of Arcobacter species with cultivation and PCR procedures, respectively. The predominant species was A. butzleri in both cattle (58.33) and sheep (55). In addition, concurrent incidence of the species was observed in 25 of the positive samples. All Arcobacter isolates were resistant to rifampicin, vancomycin, ceftriaxone, trimethoprim and cephalothin. The isolates showed high susceptibility to tetracycline, oxytetracycline, erythromycin, ciprofloxacin, kanamycin, amikacin, gentamicin and enrofloxacin. No significant difference among cattle and sheep isolates in resistance pattern was observed. The results indicate that cattle and sheep are significant intestinal carriers for Arcobacter spp. Moreover, tetracycline and aminoglycosides showed great effects on Arcobacter species in antibiogram test and can be used for treatment of human Arcobacter infections. © 2015 Elsevier Ltd
Investigating the Effect of Zinc Chloride to Control External Bleeding in Rats
Background: Despite all progresses in surgical science, bleeding caused by traffic accidents is still a challenge for surgeons to save patients’ lives. Therefore, introducing an effective method to control external bleeding is an important research priority.
Objectives: This study aimed to compare haemostatic effect of zinc chloride and simple suturing to control external bleeding.
Materials and Methods: In this animal model study, 60 male Wistar rats were used. An incision (two cm in length and half a cm in depth) was made on shaved back of rats. The hemostasis time was measured once using zinc chloride with different concentrations (5%, 10%, 15%, 25%, and 50%) and then using simple suturing. Skin tissue was assessed for pathological changes. Due to abnormal distribution of variables in Kolmogorov-Smirnov test, the data was analyzed using Kruskal-Wallis test Mann-Whitney U tests.
Results: In all the groups, complete hemostasis occurred. Hemostasis times of different concentrations of zinc chloride were significantly less than that of the control group (P < 0.001).
Conclusions: Zinc chloride was effective to control external bleeding in rats
Quantum Correlations in Neutrino Oscillation: Coherence and Entanglement
In this paper, we consider the quantum correlations, coherence and
entanglement, in neutrino oscillation. We find that the -norm as a
coherence measure is equal to sum of the three possible concurrences for
measuring the entanglement among different flavor modes which were calculated
in the paper by (M. Blasone et al., Europhys. Lett., {\bf 112}, 20007). Our
result shows that the origin of the flavor entanglement in neutrino oscillation
is the same as that of quantum coherence. Furthermore, in the wave packet
framework, the variation of -norm is investigated by varying the wave
packet width . As it is expected the amount of coherence increases
by due to the increase in the overlapping of the mass eigenstates.Comment: 12 pages; 1 figur
High-resolution radio continuum survey of M33 II. Thermal and nonthermal emission
We determine the variation in the nonthermal radio spectral index in the
nearby spiral galaxy M33 at a linear resolution of 360 pc. We separate the
thermal and nonthermal components of the radio continuum emission without the
assumption of a constant nonthermal spectral index. Using the Spitzer FIR data
at 70 and 160 m and a standard dust model, we deredden the H
emission. The extinction corrected H emission serves as a template for
the thermal free-free radio emission. Subtracting from the observed 3.6 cm and
20 cm emission (Effelsberg and the VLA) this free-free emission, we obtain the
nonthermal maps. A constant electron temperature used to obtain the thermal
radio intensity seems appropriate for M~33 which, unlike the Milky Way, has a
shallow metallicity gradient. For the first time, we derive the distribution of
the nonthermal spectral index across a galaxy, M33. We detect strong nonthermal
emission from the spiral arms and star-forming regions. Wavelet analysis shows
that at 3.6 cm the nonthermal emission is dominated by contributions from
star-forming regions, while it is smoothly distributed at 20 cm. For the whole
galaxy, we obtain thermal fractions of 51% and 18% at 3.6 cm and 20 cm,
respectively. The thermal emission is slightly stronger in the southern than in
the northern half of the galaxy. We find a clear radial gradient of mean
extinction in the galactic plane. The nonthermal spectral index map indicates
that the relativistic electrons suffer energy-loss when diffusing from their
origin in star-forming regions towards interarm regions and the outer parts of
the galaxy. We also conclude that the radio emission is mostly nonthermal at R
5 kpc in M33.Comment: 15 pages, 14 figures, accepted for publication in the Astronomy and
Astrophysics journa
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