Hyperfine frequency shift in two-dimensional atomic hydrogen

We propose the explanation of a surprisingly small hyperfine frequency shift in the two-dimensional (2D) atomic hydrogen bound to the surface of superfluid helium below 0.1 K. Owing to the symmetry considerations, the microwave-induced triplet-singlet transitions of atomic pairs in the fully spin-polarized sample are forbidden. The apparent nonzero shift is associated with the density-dependent wall shift of the hyperfine constant and the pressure shift due to the presence of H atoms in the hyperfine state $a$ not involved in the observed $b\to c$ transition. The interaction of adsorbed atoms with one another effectively decreases the binding energy and, consequently, the wall shift by the amount proportional to their density. The pressure shift of the $b\to c$ resonance comes from the fact that the impurity $a$-state atoms interact differently with the initial $b$-state and final $c$-state atoms and is also linear in density. The net effect of the two contributions, both specific for 2D hydrogen, is comparable with the experimental observation. To our knowledge, this is the first mentioning of the density-dependent wall shift. We also show that the difference between the triplet and singlet scattering lengths of H atoms, $a_t-a_s=30(5)$ pm, is exactly twice smaller than the value reported by Ahokas {\it et al.}, Phys. Rev. Lett. {\bf101}, 263003 (2008).Comment: 4 pages, no figure

Perceived barriers towards healthy eating and their association with fruit and vegetable consumption

Acknowledgements The authors would like to thank the anonymous reviewer, staff at the Health Economics Research Unit and the Rowett Institute of Nutrition and Health for helpful comments on the manuscript. Funding This work was supported by the Scottish Government Rural and Environment Science and Analytical Services (RESAS) division.Peer reviewedPostprin

An early evaluation of the 2050 Calculator international outreach programme

This paper presents the findings of an early evaluation of the UK Department of Energy and Climate Change’s 2050 Calculator International Outreach Programme. The programme supported eleven countries to develop their own versions of the 2050 Calculator. Drawing on interviews with stakeholders who were involved directly and indirectly in the development of the 2050 Calculators, this paper evaluates the process of developing these tools in different national contexts and discusses the lessons learnt so far. The findings discussed include the original motivations for involvement and how these evolved through the project, and the process of stakeholder engagement. The latter was expected to be a key benefit of the Calculator, and one which would open up debate about long term energy futures. While the teams developing the Calculators faced challenges, including data availability, political buy-in, and defining scenario trajectories, a flexible approach enabled countries to develop Calculators that were tailored to their national objectives and political environments. Overall, the 2050 Calculators have led to a wide range of benefits and there is ongoing commitment to develop new iterations and applications to use these Calculators to support planning of, and debate on, future energy and emissions trajectories

Effects of sleep hygiene and artificial bright light interventions on recovery from simulated international air travel

© 2014, Springer-Verlag Berlin Heidelberg. Purpose: Despite the reported detrimental effects of international air travel on physical performance, a paucity of interventions have been scientifically tested and confirmed to benefit travelling athletes. Consequently, the aim of the present study was to examine the effects of sleep hygiene and artificial bright light interventions on physical performance following simulated international travel. Methods: In a randomized crossover design, 13 physically active males completed 24 h of simulated international travel with (INT) and without (CON) the interventions. The mild hypoxia and cramped conditions typically encountered during commercial air travel were simulated in a normobaric, hypoxic room. Physical performance, subjective jet-lag symptoms and mood states were assessed in the morning and evening on the day prior to and for two days post-travel. Sleep quantity and quality were monitored throughout each trial. Results: Sleep duration was significantly reduced during travel in both trials (P  0.05) performance, were significantly reduced the evening of day 1 and 2 post-travel, with no differences between trials (P > 0.05). Furthermore, vigour was significantly greater (P = 0.04) the morning of day 2 in INT [5.3 (3.9–6.7)] compared to CON [2.8 (1.4–4.2)], and subjective jet-lag symptoms and mood states were significantly worse on day 2 in CON only (P < 0.05). Conclusions: Whilst reducing travel-induced sleep disruption may attenuate travel fatigue, no improvements in the recovery of physical performance were apparent

Adsorption and two-body recombination of atomic hydrogen on 3^3He-4^4He mixture films

We present the first systematic measurement of the binding energy $E_a$ of hydrogen atoms to the surface of saturated $^3$He-$^4$He mixture films. $E_a$ is found to decrease almost linearly from 1.14(1) K down to 0.39(1) K, when the population of the ground surface state of $^3$He grows from zero to $6\times10^{14}$ cm$^{-2}$, yielding the value $1.2(1)\times 10^{-15}$ K cm$^2$ for the mean-field parameter of H-$^3$He interaction in 2D. The experiments were carried out with overall $^3$He concentrations ranging from 0.1 ppm to 5 % as well as with commercial and isotopically purified $^4$He at temperatures 70...400 mK. Measuring by ESR the rate constants $K_{aa}$ and $K_{ab}$ for second-order recombination of hydrogen atoms in hyperfine states $a$ and $b$ we find the ratio $K_{ab}/K_{aa}$ to be independent of the $^3$He content and to grow with temperature.Comment: 4 pages, 4 figures, all zipped in a sigle file. Submitted to Phys. Rev. Let

Synthetic DNA immunotherapy in biochemically relapsed prostate cancer

Background: INO-5150 (PSA and PSMA) +/- INO-9012 (IL-12), a synthetic DNA immunotherapy, was assessed for safety, immunogenicity and efficacy in biochemically recurrent prostate cancer patients (pts). Methods: Phase I, open-label, multi-center study in the US included pts with rising PSA after surgery and/or RT, PSA doubling time (PSADT) \u3e3 months (mos), testosterone \u3e150 ng/dL and no concurrent ADT. Safety, immunogenicity and efficacy (PSA kinetics, PFS) were evaluated in 4 treatment arms of 15 pts each. Arms A: 2mg INO-5150, B: 8.5 mg INO-5150, C: 2mg INO-5150 + 1mg INO-9012 and D: 8.5mg INO-5150 + 1mg INO-9012. Pts received 4 IM doses of vaccine followed by electroporation on day 0, wks 3, 12 and 24 and were followed for 72 wks. Results: 50/61 (82%) pts completed all visits and treatments were well tolerated with no safety concerns. Median PFS for overall population [N = 61, baseline (D0) PSADT range (mos) 1.5-217.1, median 9.8] and for a subset of pts with D0 PSADT ≤12mos (N = 36) has not yet been reached (FU 3-19 mos). 86% of pts with D0 PSADT ≤12 mos were progression free through 19mos FU. 27 out of 36 (75%) pts with D0 PSADT≤ 12 mos had disease stabilization at wks 27 evidenced by significant improvement in log2PSA change over time (slope) and PSADT from D0 (Slope=0.19 declined to 0.1, PSADT=5.3 improved to 10.1 mos, p = \u3c0.0001). This effect was maintained at wk 72 (Slope=0.09, PSADT=10.6, p = \u3c0.0001). Immunogenicity was observed in 77% (47/61) of pts by multiple immunologic assessments. Patient immunogenicity to INO-5150 as determined by CD38 and Perforin + CD8 T cell immune reactivity correlated with attenuated % PSA rise compared to pts without reactivity (p = 0.05, n = 50). Conclusions: INO-5150 +/- INO-9012 was safe, well tolerated and immunogenic. Clinical efficacy was observed in the patients with D0 PSADT≤ 12 mos as evidenced by a significant dampening of log2PSA change over time and increased PSADT up to 72 weeks FU. Additional genomic analyses are ongoing to further elucidate the correlation of immunologic efficacy and clinical benefit. (NCT02514213)