FRANKLIN COUNTY, IOWA'S PROGRAM IN PUBLIC AFFAIRS

Public Economics,

Search for H₃⁺ isotopologues toward CRL 2136 IRS 1

Context. Deuterated interstellar molecules frequently have abundances relative to their main isotopologues much higher than the overall elemental D-to-H ratio in the cold dense interstellar medium. H₃⁺ and its isotopologues play a key role in the deuterium fractionation; however, the abundances of these isotopologues have not been measured empirically with respect to H₃⁺ to date. Aims. Our aim was to constrain the relative abundances of H₂D⁺ and D₃⁺ in the cold outer envelope of the hot core CRL 2136 IRS 1. Methods. We carried out three observations targeting H₃⁺ and its isotopologues using the spectrographs CRIRES at the VLT, iSHELL at IRTF, and EXES on board SOFIA. In addition, the CO overtone band at 2.3 μm was observed by iSHELL to characterize the gas on the line of sight. Results. The H₃⁺ ion was detected toward CRL 2136 IRS 1 as in previous observations. Spectroscopy of lines of H₂D⁺ and D₃⁺ resulted in non-detections. The 3σ upper limits of N(H₂D⁺)/N(H₃⁺) and N(D₃⁺)/N(H₃⁺) are 0.24 and 0.13, respectively. The population diagram for CO is reproduced by two components of warm gas with the temperatures 58 and 530 K, assuming a local thermodynamic equilibrium (LTE) distribution of the rotational levels. Cold gas (<20 K) makes only a minor contribution to the CO molecular column toward CRL 2136 IRS 1. Conclusions. The critical conditions for deuterium fractionation in a dense cloud are low temperature and CO depletion. Given the revised cloud properties, it is no surprise that H₃⁺ isotopologues are not detected toward CRL 2136 IRS 1. The result is consistent with our current understanding of how deuterium fractionation proceeds

Infective Native Aortic Aneurysm: a Delphi Consensus Document on Treatment, Follow Up, and Definition of Cure.

OBJECTIVE Evidence is lacking to guide the management of infective native aortic aneurysm (INAA). The aim of this study was to establish expert consensus on surgical and antimicrobial treatment and follow up, and to define when an INAA is considered cured. METHODS Delphi methodology was used. The principal investigators invited 47 international experts (specialists in infectious diseases, radiology, nuclear medicine, and vascular and cardiothoracic surgery) via email. Four Delphi rounds were performed, 3 weeks each, using an online questionnaire with initially 28 statements. The panelists rated the statements on a 5 point Likert scale. Comments on statements were analysed, statements were revised and added or deleted, and the results were presented in the iterative rounds. Consensus was defined as ≥ 75% of the panel rating a statement as strongly agree or agree on the Likert scale, and consensus on the final assessment was defined as Cronbach's α > 0.80. RESULTS All 49 panelists fulfilled all four rounds, resulting in 100% participation. One statement was added based on the results and comments of the panel, resulting in 29 final statements: n = 3 on need for consensus, n = 20 on treatment, n = 5 on follow up, and n = 1 on definition of cure. All 29 statements reached agreement of ≥ 86%. Cronbach's α increased for each consecutive round; round 1, 0.85; round 2, 0.90; round 3, 0.91; and round 4, 0.94. Thus, consensus was reached for all statements. CONCLUSION INAA is rare, and high level evidence is lacking to guide optimal management. This consensus document was established with the aim of helping clinicians manage these challenging patients, as a supplement to current guidelines. The presented consensus will need future amendments in accordance with newly acquired knowledge

Effects of Lepton Flavour Violation on Chargino Production at the Linear Collider

We study the effects of lepton flavour violation (LFV) on the production processes e+e- --> \chi+_i \chi-_j at a linear collider with longitudinal e+ and e- beam polarizations. In the case of LFV the sneutrino mass eigenstates have no definite flavour, therefore, in the t-channel more than one sneutrino mass eigenstate can contribute to the chargino production cross sections. Our framework is the Minimal Supersymmetric Standard Model (MSSM) including LFV terms. We show that in spite of the restrictions on the LFV parameters due to the current limits on rare lepton decays, the cross section \sigma(e+e- --> \chi+_1 \chi-_1) can change by a factor of 2 or more when varying the LFV mixing angles. We point out that even if the present bound on BR(tau- --> e- gamma) improves by a factor of thousand the influence of LFV on the chargino production cross section can be significant. These results could have an important impact on the strategies for determining the underlying model parameters at the linear collider.Comment: 11pp; final version for JHE

Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States

A climatological analysis of snowstorms across the contiguous United States, based on data from 1222 weather stations with data during 1901–2001, defined the spatial and temporal features. The average annual incidence of events creating 15.2 cm or more in 1 or 2 days, which are termed as snowstorms, exhibits great spatial variability. The pattern is latitudinal across most of the eastern half of the United States, averaging 0.1 storm (1 storm per 10 years) in the Deep South, increasing to 2 storms along the Canadian border. This pattern is interrupted by higher averages downwind of the Great Lakes and in the Appalachian Mountains. In the western third of the United States where snow falls, lower-elevation sites average 0.1–2 storms per year, but averages are much higher in the Cascade Range and Rocky Mountains, where 5–30 storms occur per year. Most areas of the United States have had years without snowstorms, but the annual minima are 1 or more storms in high-elevation areas of the West and Northeast. The pattern of annual maxima of storms is similar to the average pattern. The temporal distribution of snowstorms exhibited wide fluctuations during 1901–2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901–2000 was upward, corresponding to trends in strong cyclonic activity. The peak periods of storm activity in the United States occurred during 1911–20 and 1971–80, and the lowest frequency was in 1931–40. Snowstorms first occur in September in the Rockies, in October in the high plains, in November across most of the United States, and in December in the Deep South. The month with the season’s last storms is December in the South and then shifts northward, with April the last month of snowstorms across most of the United States. Storms occur as late as May and June in the Rockies and Cascades. Snowstorms are most frequent in December downwind of the Great Lakes, with the peak of activity in January for most other areas of the United States

Playing by the rules: A developmentally appropriate introduction to rugby union

The current study examined the effect of rules changes on game behaviours and opinions of under-nine rugby union players. Eighty-nine games were filmed in five counties in England; two governed by the then current rules and three governed by new pilot rules. The pilot rules were designed to create a less structured game; reducing numbers on the pitch and limiting set pieces and specialised skills. Games played under the pilot rules had 25% more ball-in-play time; 55% more runs with the ball; more than twice as many successful passes; and nearly twice as many tries scored (ps<.001). 272 players participated in a survey. Irrespective of the rules, players identified that passing, running and tackling were key activities, while having fun and playing with friends were their main reasons for playing rugby. The results suggest that the pilot rules create a competitive game that closely matches child-led informal activities.This research was funded by a CASE studentship from the ESRC’s Capacity Building Cluster in Sport, Leisure and Tourism, based at the University of Exeter (RES-187-24-0002), in partnership with the Rugby Football Union. The authors would like to thank all the clubs and players who took part in this research and to Gary Townsend (RFU) for facilitating the process. We would also like to thank Kris James for his assistance in performance analysis of matches

Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators

We describe a flexible and modular delayed-feedback nonlinear oscillator that is capable of generating a wide range of dynamical behaviours, from periodic oscillations to high-dimensional chaos. The oscillator uses electrooptic modulation and fibre-optic transmission, with feedback and filtering implemented through real-time digital-signal processing. We consider two such oscillators that are coupled to one another, and we identify the conditions under which they will synchronize. By examining the rates of divergence or convergence between two coupled oscillators, we quantify the maximum Lyapunov exponents or transverse Lyapunov exponents of the system, and we present an experimental method to determine these rates that does not require a mathematical model of the system. Finally, we demonstrate a new adaptive control method that keeps two oscillators synchronized even when the coupling between them is changing unpredictably.Comment: 24 pages, 13 figures. To appear in Phil. Trans. R. Soc. A (special theme issue to accompany 2009 International Workshop on Delayed Complex Systems