Optical and Ionospheric Phenomena at EISCAT under continuous X-mode HF pumping

We present experimental results from multiinstrument observations in the high-latitude ionospheric F2 layer at the EISCAT (European Incoherent Scatter Scientific Association) heating facility. The results come from a set of experiments, when an X-polarized HF pump wave at high heater frequencies (fH > 6.0 MHz) was injected into the F region of the ionosphere toward the magnetic zenith. Experiments were carried out under quiet magnetic conditions with an effective radiated power of 458–548 MW. HF pumping was produced at different heater frequencies, away from electron gyroharmonic frequencies, and different durations of heater pulses. We show the first experimental evidence of the excitation of artificial optical emissions at red (630 nm) and green (557.7 nm) lines in the high-latitude ionospheric F2 layer induced by an X-polarized HF pump wave. Intensities at red and green lines varied in the range 110–950 R and 50–350 R, respectively, with a ratio of green to red line of 0.35–0.5. The results of optical observations are compared with behaviors of the HF-enhanced ion and plasma lines from EISCAT UHF incoherent scatter radar data and small-scale field-aligned artificial irregularities from Cooperative UK Twin Located Auroral Sounding System observations. It was found that the X-mode radio-induced optical emissions coexisted with HF-enhanced ion and plasma lines and strong artificial field-aligned irregularities throughout the whole heater pulse. It is indicative that parametric decay or oscillating two-stream instabilities were not quenched by fully established small-scale field-aligned artificial irregularities excited by an X-mode HF pump wave

Metastability in the dilute Ising model

Consider Glauber dynamics for the Ising model on the hypercubic lattice with a positive magnetic field. Starting from the minus configuration, the system initially settles into a metastable state with negative magnetization. Slowly the system relaxes to a stable state with positive magnetization. Schonmann and Shlosman showed that in the two dimensional case the relaxation time is a simple function of the energy required to create a critical Wulff droplet. The dilute Ising model is obtained from the regular Ising model by deleting a fraction of the edges of the underlying graph. In this paper we show that even an arbitrarily small dilution can dramatically reduce the relaxation time. This is because of a catalyst effect---rare regions of high dilution speed up the transition from minus phase to plus phase.Comment: 49 page

Negative information seeking experiences of long-term prostate cancer survivors

Purpose Many prostate cancer survivors have lasting symptoms and disease-related concerns for which they seek information. To understand survivors’ information seeking experiences, we examined the topics of their information searches, their overall perceptions of the search, and perceptions of their health information seeking self-efficacy (i.e., confidence in their ability to obtain information). We hypothesized that negative search experiences and lower health information seeking self-efficacy would be associated with certain survivor characteristics such as non-white race, low income, and less education. Methods This was a retrospective study using data from the Michigan Prostate Cancer Survivor Study (state-based survey of long-term prostate cancer survivor outcomes, N=2,499, response rate = 38%). Participants recalled their last search for information and reported the topics and overall experience. We conducted multivariable regression to examine the association between survivor characteristics and the information-seeking experience. Results Nearly a third (31.7%) of prostate cancer survivors (median age of 76 years and 9 years since diagnosis) reported having negative information seeking experiences when looking for information. However, only 13.4% reported having low health information seeking self-efficacy. Lower income and less education were both significantly associated with negative information seeking experiences. Conclusions Our findings suggest that many long-term prostate cancer survivors have negative experiences when searching for information, and lower income and less education were survivor factors related to negative information seeking experiences. Implications for cancer survivors We advocate for ongoing, information needs assessment at the point-of-care as the survivorship experience progresses to assess and potentially improve survivors’ quality of life

Dynamical frustration in ANNNI model and annealing

Zero temperature quench in the Axial Next Nearest Neighbour Ising (ANNNI) model fails to bring it to its ground state for a certain range of values of the frustration parameter $\kappa$, the ratio of the next nearest neighbour antiferromagnetic interaction strength to the nearest neighbour one. We apply several annealing methods, both classical and quantum, and observe that the behaviour of the residual energy and the order parameter depends on the value of $\kappa$ strongly. Classical or thermal annealing is found to be adequate for small values of $\kappa$. However, neither classical nor quantum annealing is effective at values of $\kappa$ close to the fully frustrated point $\kappa=0.5$, where the residual energy shows a very slow algebraic decay with the number of MCS.Comment: 6 pages,10 figures, to be published in Proceedings of " The International Workshop on Quantum annealing and other Optimization Methods

Addressing the research and development gaps in modern phage therapy

Antimicrobial resistance is on the rise globally, prompting increased research and development (R&D) of phage therapy as a strategy to address difficult-to-treat bacterial infections. We review the current state of phage therapy research, including major operational, epistemic, and biological challenges for phage R&D, and discuss some new approaches to developing the technology motivated by recent breakthroughs such as artificial intelligence and synthetic phage production. In addition, we contextualize these R&D challenges and opportunities in light of the ongoing predicament of commercial antimicrobial innovation and current publicprivate efforts to reinvigorate the pipeline of antimicrobial drug discovery. We conclude with reflections on the potential for new phage therapies to be readily accessible across all income contexts to better ensure broad patient access, and consider possible alternatives to current public and publicprivate solutions for phage therapy and production.Research reported in this publication is supported by CARB-X. CARB-X’s funding for this project is provided in part with federal funds from the U.S. Department of Health and Human Services, Administration for Strategic Preparedness and Response, BARDA, under agreement number: 75A50122C00028, and by an award from Wellcome (WT224842). K.K.F.C. was supported by PHAG-ONE (Agence Nationale de la Recherche). C.K. was supported by Wellcome Trust University Award (218118_Z_19_Z(2)). The contribution from M.G.M. to this project was made possible with funds from the Leibniz Competition, project T134/2022, of the Leibniz Association.info:eu-repo/semantics/publishedVersio