Simulated forecasts for primordial B-mode searches in ground-based experiments

Detecting the imprint of inflationary gravitational waves on the $B$-mode polarization of the Cosmic Microwave Background (CMB) is one of the main science cases for current and next-generation CMB experiments. In this work we explore some of the challenges that ground-based facilities will have to face in order to carry out this measurement in the presence of Galactic foregrounds and correlated atmospheric noise. We present forecasts for Stage-3 (S3) and planned Stage-4 (S4) experiments based on the analysis of simulated sky maps using a map-based Bayesian foreground cleaning method. Our results thus consistently propagate the uncertainties on foreground parameters such as spatially-varying spectral indices, as well as the bias on the measured tensor-to-scalar ratio $r$ caused by an incorrect modelling of the foregrounds. We find that S3 and S4-like experiments should be able to put constraints on $r$ of the order $\sigma(r)=(0.5-1.0)\times10^{-2}$ and $\sigma(r)=(0.5-1.0)\times10^{-3}$ respectively, assuming instrumental systematic effects are under control. We further study deviations from the fiducial foreground model, finding that, while the effects of a second polarized dust component would be minimal on both S3 and S4, a 2\% polarized anomalous dust emission (AME) component would be clearly detectable by Stage-4 experiments.Comment: 19 pages, 11 figure

The internal and external loading differences between part-time (U16) and full-time (U18) elite English academy footballers

The aim of this study was to quantify and compare total loading (TL) of part and full- time elite English academy footballers over a 10-week period. Nineteen male youth players were categorised into their age groups; U18’s (17.7 ± 0.6 years) and U16’s (16.1 ± 0.4 years). Global Positioning Systems (GPS) and Session-Rate of Perceived Exertion (SRPE) were used to assess the external and internal measures of TL. The U18’s participated in 45 sessions as opposed to 30 for the U16’s. The U16’s (n = 48) had 22% more unexplained absences compared to the U18’s (n = 0). The TL was greater for the U18’s over a 10-week period. For the U18’s, Total Distance Covered was likely greater (54%; Moderate ES; ± 90% CL) and possibly greater for HSR (160%; Large ES; ± 90% CL) and SRPE (50%; Large ES; ± 90% CL). It was unclear if there was a difference in ACC and DEC between the ages. This study also assessed the intensities of two separate drills, session 1 (TS1) in respective age groups and session 2 (TS2) in mixed age groups. During TS1 and TS2 it was difficult to distinguish whether there were external loading differences between the age groups. Whereas, internal load was very likely greater (TS1, 18%; TS2, 22%; Large ES; 90% CL) suggesting that the U16’s perceived the drills to be harder than the U18’s. The main finding was that the U16’s had less compliance to sessions, indicating a variability in TL, which could put them at greater risk of injury. Practitioners must ensure that appropriate loading strategies are in place so that part-time players are prepared to step up to the demands of a full-time environment

Finding the chiral gravitational wave background of an axion-SU(2) inflationary model using CMB observations and laser interferometers

A detection of B-mode polarization of the Cosmic Microwave Background (CMB) anisotropies would confirm the presence of a primordial gravitational wave background (GWB). In the inflation paradigm this would be an unprecedented probe of the energy scale of inflation as it is directly proportional to the power spectrum of the GWB. However, similar tensor perturbations can be produced by the matter fields present during inflation, breaking this simple relationship. It is therefore important to be able to distinguish between different generation mechanisms of the GWB. In this paper, we analyse the detectability of a new axion-SU(2) gauge field model using its chiral, scale-dependent tensor spectrum. We forecast the detectability of the resulting CMB TB and EB cross-correlations by the LiteBIRD satellite, considering the effects of residual foregrounds, gravitational lensing, and for the first time assess the ability of such an experiment to jointly detect primordial TB and EB spectra and self-calibrate its polarimeter. We find that LiteBIRD will be able to detect the chiral signal for $r_*>0.03$ with $r_*$ denoting the tensor-to-scalar ratio at the peak scale, and that the maximum signal-to-noise for $r_*<0.07$ is $\sim 2$. We go on to consider an advanced stage of a LISA-like mission, and find that such experiments would complement CMB observations by providing sensitivity to GWB chirality on scales inaccessible to the CMB. We conclude that in order to use the CMB to distinguish this model from a conventional vacuum fluctuation model two-point statistics provide some power, but to achieve high statistical significance we would require higher order statistics which take advantage of the model's non-Gaussianity. On the other hand, in the case of a spectrum peaked at very small scales, inaccessible to the CMB, a highly significant detection could be made using space-based laser interferometers.Comment: 24 pages, 12 figures, accepted by PhysRev

An Analysis of European Shale Gas Policies: Why EU Member States are Pursuing Divergent 'Fracking' Strategies

The recent progression in hydraulic fracturing or `fracking' has enabled energy companies to extract once-considered, inaccessible hydrocarbons. The United States has been at the forefront of this controversial industry, revolutionizing the energy market by becoming the world's largest oil and natural gas producer as a result of its vast shale deposits. Shale oil and gas deposits are not unique to North America, however. EU member states are faced with the dilemma of whether to permit fracking domestically or suspend operations. The United Kingdom and Romania have issued concessions for exploring their reserves, while France and Bulgaria have halted all drilling efforts, citing environmental concerns. This paper evaluates why these four European countries pursued divergent fracking policies, arguing that energy security and Russian-relations are more relevant and powerful explanatory factors than a country's commitment to protecting the environment.Master of Art

Integrated livestock feed

United States Agency for International Developmen

Bio-SIEVE: Exploring Instruction Tuning Large Language Models for Systematic Review Automation

Medical systematic reviews can be very costly and resource intensive. We explore how Large Language Models (LLMs) can support and be trained to perform literature screening when provided with a detailed set of selection criteria. Specifically, we instruction tune LLaMA and Guanaco models to perform abstract screening for medical systematic reviews. Our best model, Bio-SIEVE, outperforms both ChatGPT and trained traditional approaches, and generalises better across medical domains. However, there remains the challenge of adapting the model to safety-first scenarios. We also explore the impact of multi-task training with Bio-SIEVE-Multi, including tasks such as PICO extraction and exclusion reasoning, but find that it is unable to match single-task Bio-SIEVE's performance. We see Bio-SIEVE as an important step towards specialising LLMs for the biomedical systematic review process and explore its future developmental opportunities. We release our models, code and a list of DOIs to reconstruct our dataset for reproducibility

Detection of prions in the faeces of sheep naturally infected with classical scrapie

Classical scrapie is a naturally transmitted prion disease of sheep and goats. Contaminated environments may contribute to the spread of disease and evidence from animal models has implicated urine, blood, saliva, placenta and faeces as possible sources of the infection. Here we sought to determine whether sheep naturally infected with classical scrapie shed prions in their faeces. We used serial protein misfolding cyclic amplification (sPMCA) along with two extraction methods to examine faeces from sheep during both the clinical and preclinical phases of the disease and showed amplification of PrPSc in 7 of 15 and 14 of 14 sheep respectively. However PrPSc was not amplified from the faeces of 25 sheep not exposed to scrapie. These data represent the first demonstration of prion shedding in faeces from a naturally infected host and thus a likely source of prion contamination in the environment

A critical re-evaluation of the Thorne-Zytkow object candidate HV 2112

It has been argued in the literature that the star HV 2112 in the Small Magellanic Cloud (SMC) is the first known example of a Thorne–Żytkow object (TŻO), a red supergiant with a degenerate neutron core. This claim is based on the star having a high luminosity (log (L/L⊙) ≳ 5), an extremely cool effective temperature, and a surface enriched in in lithium, calcium, and various irp-process elements. In this paper we re-examine this evidence, and present new measurements of the stellar properties. By compiling archival photometry from blue to mid-infrared for HV 2112 and integrating under its spectral energy distribution, we find a bolometric luminosity in the range of log (L/L⊙) = 4.70–4.91, lower than that found in previous work and comparable to bright asymptotic giant branch (AGB) stars. We compare a VLT+XSHOOTER spectrum of HV 2112 to other late-type, luminous SMC stars, finding no evidence for enhancements in Rb, Ca, or K, though there does seem to be an enrichment in Li. We therefore conclude that a much more likely explanation for HV 2112 is that it is an intermediate mass (∼5 M⊙) AGB star. However, from our sample of comparison stars we identify a new TŻO candidate, HV 11417, which seems to be enriched in Rb but for which we cannot determine a Li abundance