Degenerate and Other Neutrino Mass Scenarios and Dark Matter

I discuss in this talk mainly three topics related with dark matter motivated neutrino mass spectrum and a generic issue of mass pattern, the normal versus the inverted mass hierarchies. In the first part, by describing failure of a nontrivial potential counter example, I argue that the standard 3 $\nu$ mixing scheme with the solar and the atmospheric $\Delta m^2$'s is robust. In the second part, I discuss the almost degenerate neutrino (ADN) scenario as the unique possibility of accommodating dark matter mass neutrinos into the 3 $\nu$ scheme. I review a cosmological bound and then reanalyze the constraints imposed on the ADN scenario with the new data of double beta decay experiment. In the last part, I discuss the 3 $\nu$ flavor transformation in supernova (SN) and point out the possibility that neutrinos from SN may distinguish the normal versus inverted hierarchies of neutrino masses. By analyzing the neutrino data from SN1987A, I argue that the inverted mass hierarchy is disfavored by the data

Directed evolution of APEX2 for electron microscopy and proximity labeling

APEX is an engineered peroxidase that functions as an electron microscopy tag and a promiscuous labeling enzyme for live-cell proteomics. Because limited sensitivity precludes applications requiring low APEX expression, we used yeast-display evolution to improve its catalytic efficiency. APEX2 is far more active in cells, enabling the use of electron microscopy to resolve the submitochondrial localization of calcium uptake regulatory protein MICU1. APEX2 also permits superior enrichment of endogenous mitochondrial and endoplasmic reticulum membrane proteins.National Institutes of Health (U.S.) (DP1 OD003961

Sidescan backscatter variations of cold seeps on the Hikurangi Margin (New Zealand): indications for different stages in seep development

Cold seeps on the Hikurangi Margin off New Zealand exhibit various seabed morphologies producing different intensity patterns in backscatter images. Acoustic backscatter characteristics of 25 investigated seep sites do not show a continuous range of patterns between two end members, but fall into four distinct types characterised by variations in backscatter intensity, distribution and inferred structural heights. The types reflect different carbonate morphologies including up to 20 m high structures (type 1), low-relief crusts (type 2), scattered blocks (type 3) and carbonate free sites (type 4). Each seep corresponds to a single type; ntermediates were not observed. Although the observed morphologies and backscatter patterns may have been caused by variations in sediment burial of seep carbonates or differential exhumation by erosion, they probably epresent varying onsets of authigenic carbonate precipitation. Precipitation of carbonate is episodic, which is likely the result of internal forcing. Blocking and subsequent reorganisation of the seep plumbing system lead to abandonment of old seeps and formation of new sites