Small-Angle CMB Temperature Anisotropies Induced by Cosmic Strings

We use Nambu-Goto numerical simulations to compute the cosmic microwave background (CMB) temperature anisotropies induced at arcminute angular scales by a network of cosmic strings in a Friedmann-Lemaitre-Robertson-Walker (FLRW) expanding universe. We generate 84 statistically independent maps on a 7.2 degree field of view, which we use to derive basic statistical estimators such as the one-point distribution and two-point correlation functions. At high multipoles, the mean angular power spectrum of string-induced CMB temperature anisotropies can be described by a power law slowly decaying as \ell^{-p}, with p=0.889 (+0.001,-0.090) (including only systematic errors). Such a behavior suggests that a nonvanishing string contribution to the overall CMB anisotropies may become the dominant source of fluctuations at small angular scales. We therefore discuss how well the temperature gradient magnitude operator can trace strings in the context of a typical arcminute diffraction-limited experiment. Including both the thermal and nonlinear kinetic Sunyaev-Zel'dovich effects, the Ostriker-Vishniac effect, and the currently favored adiabatic primary anisotropies, we find that, on such a map, strings should be ``eye visible,'' with at least of order ten distinctive string features observable on a 7.2 degree gradient map, for tensions U down to GU \simeq 2 x 10^{-7} (in Planck units). This suggests that, with upcoming experiments such as the Atacama Cosmology Telescope (ACT), optimal non-Gaussian, string-devoted statistical estimators applied to small-angle CMB temperature or gradient maps may put stringent constraints on a possible cosmic string contribution to the CMB anisotropies.Comment: 17 pages, 9 figures. v2: matches published version, minor clarifications added, typo in Eq. (8) fixed, results unchange

Cosmic strings and Natural Inflation

In the present work we discuss cosmic strings in natural inflation. Our analysis is based entirely on the CMB quadrupole temperature anisotropy and on the existing upper bound on the cosmic string tension. Our results show that the allowed range for both parameters of the inflationary model is very different from the range obtained recently if cosmic strings are formed at the same time with inflation, while if strings are formed after inflation we find that the parameters of the inflationary model are similar to the ones obtained recently.Comment: 12 pages, 0 tables, 4 figures, accepted for publication in JHE

In-situ surface technique analyses and ex-situ characterization of Si1-xGex epilayers grown on Si(001)-2 ×1 by molecular beam epitaxy

Si1-xGex epilayers grown by Molecular Beam Epitaxy on Si(001) at 400 ○C have been analyzed in-situ by surface techniques such as X-ray and Ultraviolet Photoelectron Spectroscopies (XPS and UPS), Low Energy Electron Diffraction (LEED) and photoelectron diffraction (XPD). The Ge surface concentrations (x) obtained from the ratios of Ge and Si core level intensities are systematically higher than those obtained by the respective evaporation fluxes. This indicates a Ge enrichment in the first overlayers confirmed by Ge-like UPS valence band spectra. The structured crystallographic character of the epilayers is ascertained by LEED and XPD polar scans in the (100) plane since the Ge Auger LMM and the Si 2p XPD intensity patterns from the Si1-xGex epilayers are identical to those of the Si substrate. The residual stress in the epilayer is determined by ex-situ X-ray diffraction (XRD) which also allows, as Rutherford Back Scattering (RBS), Ge concentration determinations

From Resistance to Receptiveness: Farmer Willingness to Participate in Extension Discussions About Climate Variability and Climate Change

Identifying what Extension professionals believe are the critical elements of a communication strategy that is most likely to encourage agricultural producers to participate in discussions of climate variability and climate change is pivotal to providing timely solutions to issues facing farmers. The current study involved interviews with 50 Extension professionals from four southeastern states (Alabama, Florida, Georgia, and South Carolina) who were engaged in ongoing work related to climate and agriculture. Respondents were asked to assess how best to engage farmers in conversations related to climate variability and climate change. Qualitative analysis showed that Extension professionals recommended avoiding content related to politics, attribution of climate change to human causes, and telling farmers what to do. Respondents recommended emphasizing adaptation strategies, climate variability over climate change, evidence that climate change exists, and the financial benefits for farmers. In addition, Extension professionals proposed several delivery methods they thought would be most effective with farmers, including delivery tailored to the characteristics of the audience, a positive overall tone, and an understanding that engagement should be viewed as a long-term process based on building relationships with farmers. The findings suggest that farmers are a potentially receptive audience on climate issues when properly approached

Profitability, Engaging Delivery, and Trust: How Extension Professionals Can Optimize Farmer Adoption of Climate-related Adaptation Strategies

This study examined Extension professionals’ perspectives on how to optimize the chances that farmers will adopt climate adaptation strategies designed to minimize risks associated with climate variability and climate change. In-depth interviews were conducted with Extension professionals in four southeastern states (Alabama, Florida, Georgia, and South Carolina). Responses were coded and analyzed, resulting in three recommendations. First, focus on profitability and issues of immediate concern to farmers. Second, use engaging delivery methods, especially field trials conducted under realistic conditions. Third, build trust with farmers, primarily by focusing on research-based information. This study has practical implications for how Extension professionals should approach the work of addressing climate issues in agriculture

Climate-Related Risks and Management Issues Facing Agriculture in the Southeast: Interviews with Extension Professionals

To explore Extension professionals\u27 perceptions of the potential impact of climate variability and climate change on agriculture and to identify the top climate-related issues facing farmers, we conducted interviews with agricultural Extension personnel from Alabama, Florida, Georgia, and South Carolina. Of those interviewed, 92% believed climate change will affect agriculture a moderate amount or a great deal. Qualitative analyses revealed that the Extension professionals considered scarcity of water resources, temperature fluctuations, pest and disease pressures, forecast challenges, seasonal variability, and adaptation strategies as among the most important climate-related issues affecting agriculture in the Southeast

Transcatheter tricuspid valve implantation: A multicentre French study

SummaryBackgroundTranscatheter valve-in-valve (VIV) implantation in failing bioprosthesis is an emerging field in cardiology.AimTo report on a French multicentre experience and a literature review of tricuspid VIV implantation.MethodsWe approached different institutions and collected 10 unpublished cases; a literature review identified 71 patients, including our 10 cases. Clinical aspects and haemodynamic data are discussed.ResultsAmong our 10 unpublished cases, the reason for implantation was significant tricuspid stenosis (n=4), significant tricuspid regurgitation (n=1) or mixed lesion (n=5). Implantation was performed under general anaesthesia at mean age 28±17 years. The 22mm Melody valve was implanted in seven patients; the Edwards SAPIEN valve was implanted in three patients. The procedure succeeded in all cases, despite two embolizations in the right cardiac chambers; in both cases, the valve was stabilized close to the tricuspid annulus using a self-expandable stent, before implantation of a second Edwards SAPIEN valve. Functional class improved in all but one case. Mean diastolic gradient decreased from 9±2.45mmHg to 3.65±0.7mmHg (p=0.007); no more than trivial regurgitation was noticed. Among the published cases, the Melody valve was implanted in 41 patients, the Edwards SAPIEN valve in 29 patients and the Braile valve in one patient. Short-term results were similar for our 10 cases, but mid-term results are not yet available.ConclusionsTricuspid VIV implantation using the Melody or Edwards SAPIEN valves is a feasible and effective procedure for selected patients with failing bioprosthesis

Demonstration of the metaphylactic use of gamithromycin against bacterial pathogens associated with bovine respiratory disease in a multicentre farm trial

On five commercial cattle rearing sites across Europe, a total of 802 young cattle at high risk of developing bovine respiratory disease (BRD) associated with the bacterial pathogens Mannheimia haemolytica or Pasteurella multocida and/or Mycoplasma bovis were enrolled into a multicentre, controlled field trial. Half were treated with a single dose of gamithromycin at 6 mg/kg bodyweight by subcutaneous injection and half received an injection of a saline placebo as the control. All animals were observed daily for 14 days for signs of BRD as defined by set criteria. The proportion of metaphylactic preventive treatment successes, defined as animals surviving to day 14 without signs of BRD, in the gamithromycin-treated group (86 per cent) was significantly (P=0.0012) higher than in the saline-treated controls (61 per cent). Morbidity among the treated animals was reduced by 64 per cent compared with the controls

Toward Engagement in Climate Training: Findings from Interviews with Agricultural Extension Professionals

With scientific consensus regarding the occurrence of climate variability and climate change it is clear that farmers can benefit from science-based adaptation strategies for managing climate-related risk. To this end, cooperative extension professionals must engage in climate training events that are carefully planned and tailored to their specific needs. This study consisted of 50 interviews with extension professionals from four states (Alabama, Florida, Georgia, and South Carolina) and collected information about the perceptions of climate variability and change as well as the preferred approaches for climate-related training in extension. Results include the need for accessible, climate-related training that prepares extension professionals to: understand both management- and technology-related adaptation strategies, engage in productive conversations with all stakeholders, and participate in the coproduction of knowledge related to climate issues

D-term inflation in non-minimal supergravity

D-term inflation is one of the most interesting and versatile models of inflation. It is possible to implement naturally D-term inflation within high energy physics, as for example SUSY GUTs, SUGRA, or string theories. D-term inflation avoids the $\eta$-problem, while in its standard form it always ends with the formation of cosmic strings. Given the recent three-year WMAP data on the cosmic microwave background temperature anisotropies, we examine whether D-term inflation can be successfully implemented in non-minimal supergravity theories. We show that for all our choices of K\"ahler potential, there exists a parameter space for which the predictions of D-term inflation are in agreement with the measurements. The cosmic string contribution on the measured temperature anisotropies is always dominant, unless the superpotential coupling constant is fine tuned; a result already obtained for D-term inflation within minimal supergravity. In conclusion, cosmic strings and their r\^ole in the angular power spectrum cannot be easily hidden by just considering a non-flat K\"ahler geometry.Comment: 29 pages, 9 figures; minor changes to match publihed versio