12 research outputs found
Magneto-optical Kerr effect in
We have measured the magneto-optical Kerr rotation of ferromagnetic
with x=0.2 and 0.4, as well as of serving as
the non-magnetic reference material. As previously for , we could
identify a feature at 1 in the Kerr response which is related with
electronic transitions involving the localized 4f electron states. The absence
of this feature in the data for confirms the relevance of the
partially occupied 4f states in shaping the magneto-optical features of
-based hexaborides. Disorder by -doping broadens the itinerant charge
carrier contribution to the magneto-optical spectra
X-Ray Polarization of Solar Flares Measured with Rhessi
The degree of linear polarization in solar flares has not yet been precisely
determined despite multiple attempts to measure it with different missions. The
high energy range in particular has very rarely been explored, due to its
greater instrumental difficulties. We approached the subject using the Reuven
Ramaty High Energy Spectroscopic Imager (RHESSI) satellite to study 6 X-class
and 1 M-class flares in the energy range between 100 keV and 350 keV. Using
RHESSI as a polarimeter requires the application of strict cuts to the event
list in order to extract those photons that are Compton scattered between two
detectors. Our measurements show polarization values between 2% and 54%, with
errors ranging from 10% to 26% in 1 sigma level. In view of the large
uncertainties in both the magnitude and direction of the polarization vector,
the results can only reject source models with extreme properties.Comment: 26 pages, 11 figures, accepted for publication by Solar Physic
Molecular phenotyping of multiple mouse strains under metabolic challenge uncovers a role for <i>Elovl2</i> in glucose-induced insulin secretion.
In type 2 diabetes (T2D), pancreatic β cells become progressively dysfunctional, leading to a decline in insulin secretion over time. In this study, we aimed to identify key genes involved in pancreatic beta cell dysfunction by analyzing multiple mouse strains in parallel under metabolic stress.
Male mice from six commonly used non-diabetic mouse strains were fed a high fat or regular chow diet for three months. Pancreatic islets were extracted and phenotypic measurements were recorded at 2 days, 10 days, 30 days, and 90 days to assess diabetes progression. RNA-Seq was performed on islet tissue at each time-point and integrated with the phenotypic data in a network-based analysis.
A module of co-expressed genes was selected for further investigation as it showed the strongest correlation to insulin secretion and oral glucose tolerance phenotypes. One of the predicted network hub genes was <i>Elovl2</i> , encoding Elongase of very long chain fatty acids 2. <i>Elovl2</i> silencing decreased glucose-stimulated insulin secretion in mouse and human β cell lines.
Our results suggest a role for <i>Elovl2</i> in ensuring normal insulin secretory responses to glucose. Moreover, the large comprehensive dataset and integrative network-based approach provides a new resource to dissect the molecular etiology of β cell failure under metabolic stress