Thermo-optical interactions in a dye-microcavity photon Bose-Einstein condensate

Superfluidity and Bose-Einstein condensation are usually considered as two closely related phenomena. Indeed, in most macroscopic quantum systems, like liquid helium, ultracold atomic Bose gases, and exciton-polaritons, condensation and superfluidity occur in parallel. In photon Bose-Einstein condensates realized in the dye microcavity system, thermalization does not occur by direct interaction of the condensate particles as in the above described systems, i.e. photon-photon interactions, but by absorption and re-emission processes on the dye molecules, which act as a heat reservoir. Currently, there is no experimental evidence for superfluidity in the dye microcavity system, though effective photon interactions have been observed from thermo-optic effects in the dye medium. In this work, we theoretically investigate the implications of effective thermo-optic photon interactions, a temporally delayed and spatially non-local effect, on the photon condensate, and derive the resulting Bogoliubov excitation spectrum. The calculations suggest a linear photon dispersion at low momenta, fulfilling the Landau's criterion of superfluidity . We envision that the temporally delayed and long-range nature of the thermo-optic photon interaction offer perspectives for novel quantum fluid phenomena.Comment: 21 pages, 5 figure

Physical and psychological challenges faced by military, medical and public safety personnel relief workers supporting natural disaster operations: a systematic review

Natural disasters, including floods, earthquakes, and hurricanes, result in devastating consequences at the individual and community levels. To date, much of the research reflecting the consequences of natural disasters focuses heavily on victims, with little attention paid to the personnel responding to such disasters. We conducted a systematic review of the challenges faced by military, medical and public safety personnel supporting natural disaster relief operations. Specifically, we report on the current evidence reflecting challenges faced, as well as positive outcomes experienced by military, medical and public safety personnel following deployment to natural disasters. The review included 382 studies. A large proportion of the studies documented experiences of medical workers, followed by volunteers from humanitarian organizations and military personnel. The most frequently reported challenges across the studies were structural (i.e., interactions with the infrastructure or structural institutions), followed by resource limitations, psychological, physical, and social challenges. Over 60% of the articles reviewed documented positive or transformative outcomes following engagement in relief work (e.g., the provision of additional resources, support, and training), as well as self-growth and fulfillment. The current results emphasize the importance of pre-deployment training to better prepare relief workers to manage expected challenges, as well as post-deployment supportive services to mitigate adverse outcomes and support relief workers’ well-being

Structure activity relations of Myxinidin, an antibacterial peptide derived from Epidermal Mucus of Hagfish.

The structure activity relations of myxinidin a peptide derived from epidermal mucus of hagfish, Myxine glutinosa L. were investigated. Analysis of key residues allowed us to design new peptides with increased efficiency. Antimicrobial activity of native and modified peptides demonstrated the key role of uncharged residues in the sequence; the loss of these residues reduces almost entirely Myxinidin antimicrobial activity, whilst insertion of arginine at charged and uncharged position increases antimicrobial activity as compared with native myxinidin. Particularly, we designed a peptide capable of achieving a high inhibitory effect on bacterial growth. Experiments were conducted using both Gram-negative and Gram-positive bacteria. NMR studies showed that myxinidin is able to form an amphipathic α-helical structure at the N-terminus and a random coil region at the C-terminus