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Abstract: A recent direction in dark matter phenomenology has been to consider multi-component dark matter, containing subsectors with interesting interactions and structure. These include models where part of dark matter is dissipative. In these particular models, the dissipative subsector will cool to form a dark matter disk, whose size, density, and temperature can be predicted from the parameters of the model. I will discuss details of the model and of the disk formation process, as well as various observational constraints and possible evidence for such a disk. I will also discuss potential astrophysical constraints from recent Gaia data, and under what assumptions these constraints should be taken seriously.

Nature provides an excellent source of inspiration for optical and mechanical materials.
In this talk, I will discuss opto-mechanical structures with nano scale precision.
In particular, I will show our recent results on micro/nano robotic elements that use light as source of energy and that are controlled by light as well.

Surface force experiments by the Perkin group suggest that the Debye screening length in aqueous solutions is not monotonic in electrolyte concentration. I shall review the fundamentals of Debye-Huckel theory and discuss some possible scenarios to understand the experimental observations.

In yeast, the knock out of individual ribosomal protein (RP) genes
leads to a wide range of life span phenotypes, some mutants having
significantly increased, other significantly decreased life span. In
this talk I would like to present our efforts in characterizing the
regulation of mRNA translation in relation to cellular states, from
yeast to man. I will describe our work on inferring determinants of
protein synthesis rates in yeast, where we found that the Gcn4
transcription factor, which is induced in many conditions that enhance
yeast lifespan (RP gene knockout, calorie restriction, mTOR
inhibition) not only activates transcription of amino acid
biosynthesis genes, but also represses protein biosynthesis. How much
variation in RP expression is expected in human tissues has been
largely unknown, but RP gene mutations have been described in
association with hematological disorders. Through a comprehensive
analysis of human RP mRNAs expression pattern across 28 tissues, over
300 primary cells and 16 tumor types, we identified many RPs which
exhibit tissue-specific expression. In the hematopoietic system, a
small number of RP genes, possible regulated by transcription factors
with tissue-specific expression, unequivocally discriminate cells of distinct
lineages and developmental stages. Different cancer types also show
dysregulated expression of individual RPs, some RPs having a relative
increase and other decrease in expression. Finally, I will discuss our efforts
in mapping sites of snoRNA-guided RNA modifications.

HIV enters its host cells by membrane fusion, initiated by the gp41 subunit of its envelope protein. In addition, gp41 has been shown to prevent T-cell activation. This is suggested to occur during the membrane fusion process and is attributed to various membrane binding regions of gp41. Although extensively studied, the cytosolic region of gp41, termed the cytoplasmic tail (CT), has not been examined in the context of immune suppression. Here we investigated whether the CT inhibits T-cell activation by utilizing gp41 derived peptides and full gp41 constructs expressed in human T-cells. We found that a conserved region of the CT specifically inhibits T-cell activation through a unique inhibitory mechanism able to take place post membrane fusion.