Prospects for measurement and control of the scattering length of metastable helium using photoassociation techniques

A numerical investigation of two-laser photoassociation (PA) spectroscopy on spin-polarized metastable helium (He*) atoms is presented within the context of experimental observation of the least-bound energy level in the scattering potential and subsequent determination of the s-wave scattering length. Starting out from the model developed by Bohn and Julienne [Phys. Rev. A \textbf{60}, (1999) 414], PA rate coefficients are obtained as a function of the parameters of the two lasers. The rate coefficients are used to simulate one- and two-laser PA spectra. The results demonstrate the feasibility of a spectroscopic determination of the binding energy of the least-bound level. The simulated spectra may be used as a guideline when designing such an experiment, whereas the model may also be employed for fitting experimentally obtained PA spectra. In addition, the prospects for substantial modification of the He* scattering length by means of optical Feshbach resonances are considered. Several experimental issues relating to the numerical investigation presented here are discussed.Comment: 9 pages, 7 figure

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

Measurement of the inclusive jet cross section in pp collisions at √s=2.76 TeV

The double-differential inclusive jet cross section is measured as a function of jet transverse momentum pT and absolute rapidity IyI, using proton-proton collision data collected with the CMS experiment at the LHC, at a center-of-mass energy of √s=2.76 TeV and corresponding to an integrated luminosity of 5.43 pb⁻¹. Jets are reconstructed within the pT range of 74 to 592 GeV and the rapidity range IyI < 3.0.The reconstructed jet spectrum is corrected for detector resolution. The measurements are compared to the theoretical prediction at next-to-leading-order QCD using different sets of parton distribution functions. This inclusive cross section measurement explores a new kinematic region and is consistent with QCD predictions

Mechanisms of glucocorticoid signalling

It has become increasingly clear that glucocorticoid signalling not only comprises the binding of the glucocorticoid receptor (GR) to its response element (GRE), but also involves indirect regulation glucocorticoid-responsive genes by regulating or interacting with other transcription factors. In addition, they can directly regulate gene expression by binding to negative glucocorticoid response elements (nGREs), to simple GREs, to GREs, or to GREs and GRE half sites (GRE1/2s) that are part of a regulatory unit. A response unit allows a higher level of glucocorticoid induction than simple GREs and, in addition, allows the integration of tissue-specific information with the glucocorticoid response. Presumably, the complexity of such a glucocorticoid response unit (GRU) depends on the number of pathways that integrate at this unit. Because GRUs are often located at distant sites relative to the transcription-start site, the GRU has to find a way to communicate with the basal-transcription machinery. We propose that the activating signal of a distal enhancer can be relayed onto the transcription-initiation complex by coupling elements located proximal to the promote

Collective Bargaining on Employment Security: The Influence of the Legal Framework

Employers’ organisations and trade unions (also called the social partners) are given a central role to play in the specification of employment security into concrete regulations through collective bargaining. The question is how employment security can be implemented through collective bargaining. This contribution builds on the assumption that collective bargaining outcomes are influenced by inter alia political, socio-economic, and legal constrains. The chapter seeks to explore the legal framework of collective bargaining in which employment security is (to be) developed and to point out the ways in which this framework can have an effect on employment security and the way it is being shaped