Electron microscopic and biochemical characterization of Fraction 1 protein

High resolution electron microscopy of Fraction I protein from plant leave

Discovery of the supernova remnant G351.0-5.4

Context. While searching the NRAO VLA Sky Survey (NVSS) for diffuse radio emission, we have serendipitously discovered extended radio emission close to the Galactic plane. The radio morphology suggests the presence of a previously unknown Galactic supernova remnant. An unclassified {\gamma}-ray source detected by EGRET (3EG J1744-3934) is present in the same location and may stem from the interaction between high-speed particles escaping the remnant and the surrounding interstellar medium. Aims. Our aim is to confirm the presence of a previously unknown supernova remnant and to determine a possible association with the {\gamma}-ray emission 3EG J1744-3934. Methods. We have conducted optical and radio follow-ups of the target using the Dark Energy Camera (DECam) on the Blanco telescope at Cerro Tololo Inter-American Observatory (CTIO) and the Giant Meterwave Radio Telescope (GMRT). We then combined these data with archival radio and {\gamma}-ray observations. Results. While we detected the extended emission in four different radio bands (325, 1400, 2417, and 4850 MHz), no optical counterpart has been identified. Given its morphology and brightness, it is likely that the radio emission is caused by an old supernova remnant no longer visible in the optical band. Although an unclassified EGRET source is co-located with the supernova remnant, Fermi-LAT data do not show a significant {\gamma}-ray excess that is correlated with the radio emission. However, in the radial distribution of the {\gamma}-ray events, a spatially extended feature is related with SNR at a confidence level $\sim 1.5$ {\sigma}. Conclusions. We classify the newly discovered extended emission in the radio band as the old remnant of a previously unknown Galactic supernova: SNR G351.0-5.4.Comment: 6 pages, 6 figures, accepted A&

Constraining magnetic fields in galaxy clusters

Magnetic fields originate small-scale instabilities in the plasma of the intra-cluster medium, and may have a key role to understand particle acceleration mechanisms. Recent observations at low radio frequencies have revealed that synchrotron emission from galaxy clusters is more various and complicated than previously thought, and new types of radio sources have been observed. In the last decade, big steps forward have been done to constrain the magnetic field properties in clusters thanks to a combined approach of polarisation observations and numerical simulations that aim to reproduce Faraday Rotation measures of sources observed through the intra-cluster medium. In this contribution, I will review the results on magnetic fields reached in the last years, and I will discuss the assumptions that have been done so far in light of new results obtained from cosmological simulations. I will also discuss how the next generation of radio instruments, as the SKA, will help improving our knowledge of the magnetic field in the intra-cluster medium

Reassociation of hemocyanins from subunit mixtures

Reactions of hemocyanin from different biological origins studied by electron microscop

Exploring the relation between turbulent velocity and density fluctuations in the stratified intracluster medium

Context. The dynamics of the intracluster medium (ICM) is affected by turbulence driven by several processes, such as mergers, accretion and feedback from active galactic nuclei. Aims. X-ray surface brightness fluctuations have been used to constrain turbulence in galaxy clusters. Here, we use simulations to further investigate the relation between gas density and turbulent velocity fluctuations, with a focus on the effect of the stratification of the ICM. Methods. In this work, we studied the turbulence driven by hierarchical accretion by analysing a sample of galaxy clusters simulated with the cosmological code ENZO. We used a fixed scale filtering approach to disentangle laminar from turbulent flows. Results. In dynamically perturbed galaxy clusters, we found a relation between the root mean square of density and velocity fluctuations, albeit with a different slope than previously reported. The Richardson number is a parameter that represents the ratio between turbulence and buoyancy, and we found that this variable has a strong dependence on the filtering scale. However, we could not detect any strong relation between the Richardson number and the logarithmic density fluctuations, in contrast to results by recent and more idealised simulations. In particular, we find a strong effect from radial accretion, which appears to be the main driver for the gas fluctuations. The ubiquitous radial bias in the dynamics of the ICM suggests that homogeneity and isotropy are not always valid assumptions, even if the turbulent spectra follow Kolmogorov's scaling. Finally, we find that the slope of the velocity and density spectra are independent of cluster-centric radii

Macromolecular organization of hemocyanins and apohemocyanins as revealed by electron microscopy

Comparative high resolution electron microscopic studies of structural organization of hemocyanins and apohemocyanins from mollusca and arthropod

Probing the origin of extragalactic magnetic fields with Fast Radio Bursts

The joint analysis of the Dispersion and Faraday Rotation Measure from distant, polarised Fast Radio Bursts may be used to put constraints on the origin and distribution of extragalactic magnetic fields on cosmological scales. While the combination of Dispersion and Faraday Rotation Measure can in principle give the average magnetic fields along the line-of-sight,in practice this method must be used with care because it strongly depends on the assumed magnetisation model on large cosmological scales. Our simulations show that the observation of Rotation Measures with greater than or equal to 1 − 10 rad/m2 in ∼ 10^2 − 10^3 Fast Radio Bursts will likely be able to discriminate between extreme scenarios for the origin of cosmic magnetic fields, independent of the exact distribution of sources with redshift. This represent a strong case for incoming (e.g. ALERT, CHIME) and future (e.g. with the Square Kilometer Array) radio polarisation surveys of the sky