Ising pyrochlore magnets: Low temperature properties, ice rules and beyond

Pyrochlore magnets are candidates for spin-ice behavior. We present theoretical simulations of relevance for the pyrochlore family R2Ti2O7 (R= rare earth) supported by magnetothermal measurements on selected systems. By considering long ranged dipole-dipole as well as short-ranged superexchange interactions we get three distinct behaviours: (i) an ordered doubly degenerate state, (ii) a highly disordered state with a broad transition to paramagnetism, (iii) a partially ordered state with a sharp transition to paramagnetism. Thus these competing interactions can induce behaviour very different from conventional ``spin ice''. Closely corresponding behaviour is seen in the real compounds---in particular Ho2Ti2O7 corresponds to case (iii) which has not been discussed before, rather than (ii) as suggested earlier.Comment: 5 pages revtex, 4 figures; some revisions, additional data, additional co-authors and a changed title. Basic ideas of paper remain the same but those who downloaded the original version are requested to get this more complete versio

The potential link between sugar-sweetened beverage consumption and post-exercise airway narrowing across puberty: a longitudinal cohort study

Citation: Emerson, S. R., Rosenkranz, S. K., Rosenkranz, R. R., Kurti, S. P., & Harms, C. A. (2016). The potential link between sugar-sweetened beverage consumption and post-exercise airway narrowing across puberty: a longitudinal cohort study. Public Health Nutrition, 19(13), 2435-2440. doi:10.1017/s1368980015003109Objective The prevalence of asthma is rising, presenting serious public health challenges. Recent data suggest that sugar-sweetened beverage (SSB) consumption plays a role in asthma aetiology. The purpose of the present study was to determine whether SSB consumption is linked to post-exercise airway narrowing (predictor of asthma development) across puberty. Design Participants completed pulmonary function tests, physical activity and dietary habit questionnaires, and an exercise test to exhaustion. Setting Community in Manhattan, Kansas, USA. Subjects We recruited ten boys and ten girls from an original cohort of forty participants tested in our laboratory approximately 5 years prior. Participants were aged 97 (sd 09) years at baseline and 147 (sd 09) years at follow-up. Results Pre-puberty, boys consumed 68 (sd 48) servings/week and girls consumed 69 (sd 37) servings/week, while post-puberty boys consumed 115 (sd 53) servings/week and girls consumed 77 (sd 43) servings/week. Using Pearson correlation, SSB consumption was not significantly related to post-exercise airway narrowing at pre-puberty (r=-035, P=0130). In linear regression analyses, SSB consumption was significantly related to post-exercise airway narrowing post-puberty before (standardized =-060, P=0005) but not after (standardized =-033, P=0211) adjustment for confounders. Change in SSB consumption from pre- to post-puberty was significantly associated with post-exercise airway narrowing post-puberty (r=-061, P=0010) and change in post-exercise airway narrowing from pre- to post-puberty (r=-045, P=0048) when assessed via Pearson correlations. Conclusions These findings suggest a possible link between SSB consumption and asthma development during maturation. Reduced SSB intake may be a possible public health avenue for blunting rising asthma prevalence

Household Air Pollution Exposure and Influence of Lifestyle on Respiratory Health and Lung Function in Belizean Adults and Children: A Field Study

Citation: Kurti, S. P., Kurti, A. N., Emerson, S. R., Rosenkranz, R. R., Smith, J. R., Harms, C. A., & Rosenkranz, S. K. (2016). Household Air Pollution Exposure and Influence of Lifestyle on Respiratory Health and Lung Function in Belizean Adults and Children: A Field Study. International Journal of Environmental Research and Public Health, 13(7), 12. doi:10.3390/ijerph13070643Household air pollution (HAP) contributes to the global burden of disease. Our primary purpose was to determine whether HAP exposure was associated with reduced lung function and respiratory and non-respiratory symptoms in Belizean adults and children. Our secondary purpose was to investigate whether lifestyle (physical activity (PA) and fruit and vegetable consumption (FV)) is associated with reported symptoms. Belizean adults (n = 67, 19 Male) and children (n = 23, 6 Male) from San Ignacio Belize and surrounding areas participated in this cross-sectional study. Data collection took place at free walk-in clinics. Investigators performed initial screenings and administered questionnaires on (1) sources of HAP exposure; (2) reported respiratory and non-respiratory symptoms and (3) validated lifestyle questionnaires. Participants then performed pulmonary function tests (PFTs) and exhaled breath carbon monoxide (CO). There were no significant associations between HAP exposure and pulmonary function in adults. Increased exhaled CO was associated with a significantly lower forced expiratory volume in 1-s divided by forced vital capacity (FEV1/FVC) in children. Exposed adults experienced headaches, burning eyes, wheezing and phlegm production more frequently than unexposed adults. Adults who met PA guidelines were less likely to experience tightness and pressure in the chest compared to those not meeting guidelines. In conclusion, adults exposed to HAP experienced greater respiratory and non-respiratory symptoms, which may be attenuated by lifestyle modifications

Analysis of Jovian decamteric data: Study of radio emission mechanisms

This research effort involved careful examination of Jovian radio emission data below 40 MHz, with emphasis on the informative observations of the Planetary Radio Astronomy experiment (PRA) on the Voyager 1 and 2 spacecraft. The work is divided into three sections, decametric arcs, decametric V bursts, and hectometric modulated spectral activity (MSA)

Destroying coherence in high temperature superconductors with current flow

The loss of single-particle coherence going from the superconducting state to the normal state in underdoped cuprates is a dramatic effect that has yet to be understood. Here, we address this issue by performing angle resolved photoemission spectroscopy (ARPES) measurements in the presence of a transport current. We find that the loss of coherence is associated with the development of an onset in the resistance, in that well before the midpoint of the transition is reached, the sharp peaks in the ARPES spectra are completely suppressed. Since the resistance onset is a signature of phase fluctuations, this implies that the loss of single-particle coherence is connected with the loss of long-range phase coherence.Comment: 7 pages, 7 figure

Wildcat wellness coaching feasibility trial: protocol for home-based health behavior mentoring in girls

Citation: Cull, B. J., Rosenkranz, S. K., Dzewaltowski, D. A., Teeman, C. S., Knutson, C. K., & Rosenkranz, R. R. (2016). Wildcat wellness coaching feasibility trial: protocol for home-based health behavior mentoring in girls. Pilot and Feasibility Studies, 2(1), 26. https://doi.org/10.1186/s40814-016-0066-yChildhood obesity is a major public health problem, with one third of America’s children classified as either overweight or obese. Obesity prevention and health promotion programs using components such as wellness coaching and home-based interventions have shown promise, but there is a lack of published research evaluating the impact of a combined home-based and wellness coaching intervention for obesity prevention and health promotion in young girls. The main objective of this study is to test the feasibility of such an intervention on metrics related to recruitment, intervention delivery, and health-related outcome assessments. The secondary outcome is to evaluate the possibility of change in health-related psychosocial, behavioral, and biomedical outcomes in our sample of participants

Superconductivity and hybrid soft modes in TiSe2_2

The competition between superconductivity and other ground states of solids is one of the challenging topics in condensed matter physics. Apart from high-temperature superconductors [1,2] this interplay also plays a central role in the layered transition-metal dichalcogenides, where superconductivity is stabilized by suppressing charge-density-wave order to zero temperature by intercalation [3] or applied pressure [4-7]. 1T-TiSe$_2$ forms a prime example, featuring superconducting domes on intercalation as well as under applied pressure. Here, we present high energy-resolution inelastic x-ray scattering measurements of the CDW soft phonon mode in intercalated Cu$_x$TiSe$_2$ and pressurized 1T-TiSe$_2$ along with detailed ab-initio calculations for the lattice dynamical properties and phonon-mediated superconductivity. We find that the intercalation-induced superconductivity can be explained by a solely phonon-mediated pairing mechanism, while this is not possible for the superconducting phase under pressure. We argue that a hybridization of phonon and exciton modes in the pairing mechanism is necessary to explain the full observed temperature-pressure-intercalation phase diagram. These results indicate that 1T-TiSe$_2$ under pressure is close to the elusive state of the excitonic insulator