Petrographic and micro-Raman study of thermal and shock metamorphism in Mezőmadaras, Knyahinya and Mócs L-Chondrites

We investigated three Hungarian L-chondrites: Mezőmadaras, Knyahinya, and Mócs sample. In Knyahinya chondrite, two phenomena were observed as follows: the weak mosaicism (S4) and mechanical twins in pyroxene. The Mócs sample is characterized by strong shock metamorphic effects such as high density of fractures and abundant shock-veins. Planar Deformation Features (PDFs) were identified in two olivine grains, and an olivine grain shows well-developed Planar Fractures (PFs). In Mezőmadaras sample, there are irregular fractures (S1), and PFs (S3), and mechanical twins in pyroxene. We have reinvestigated of these meteorite samples using Raman spectroscopy for the identification of shock-metamorphic effects, which occurred in the structure changes of olivine and pyroxene grains. The olivine doublet peak position is shifted to higher wavenumbers, due to partly disordered olivine structure. We observed that minerals with mechanical twins exhibit less interference color, compared to the non-shocked minerals, especially pyroxene. It is important to note that, the mechanical twins were complicated to describe, only the direction of the deformation was determined. On the basis of the measured FWHM, the following structural disordering degree of the selected samples can be determined as a (growing rate): Castle Rock, Mezőmadaras, Shergotty and Mócs. The result reveals that amorphization rate is the highest in Mócs and Shergotty pyroxene grains

Dihydrolipoic acid reduces cytochrome b561 proteins.

Cytochrome b561 (Cyt-b561) proteins constitute a family of trans-membrane proteins that are present in a wide variety of organisms. Two of their characteristic properties are the reducibility by ascorbate (ASC) and the presence of two distinct b-type hemes localized on two opposite sides of the membrane. Here we show that the tonoplast-localized and the putative tumor suppressor Cyt-b561 proteins can be reduced by other reductants than ASC and dithionite. A detailed spectral analysis of the ASC-dependent and dihydrolipoic acid (DHLA)-dependent reduction of these two Cyt-b561 proteins is also presented. Our results are discussed in relation to the known antioxidant capability of DHLA as well as its role in the regeneration of other antioxidant compounds of cells. These results allow us to speculate on new biological functions for the trans-membrane Cyt-b561 proteins

Variation of non-reductive geometric invariant theory

Two decades ago Thaddeus, and independently Dolgachev and Hu, studied the dependence of geometric invariant theoretic quotients on the linearisations used in their construction. In this article we show that a similar picture of Variation of Geometric Invariant Theory (VGIT) exists for suitable non-reductive GIT quotients