A novel approach to the global analysis of proton form factors in elastic electron-proton scattering

We present a novel method for the global analysis of elastic electron-proton scattering when combining data sets from experiments with different overall normalization uncertainties. The method is a modification of one employed by the NNPDF collaboration in the fitting of parton distribution data. This method is an alternative to the 'penalty trick' method traditionally employed in global fits to proton electric and magnetic form factors, while avoiding the biases inherent in that approach. We discuss issues that arise when extending the method to nonlinear models. For data with $Q^2>1$ GeV$^2$ we find relatively minor differences to traditional model fits when the normalization uncertainties from different experiments are correctly accounted for. We discuss implications of this method for the well-known discrepancy between the form factor ratio $G_E/G_M$ extracted from the Rosenbluth and polarization transfer techniques.Comment: 5 pages, 4 figures, 2 table

Near threshold all-optical backaction amplifier

A near threshold all-optical backaction amplifier is realized. Operating near threshold in an integrated micronscale architecture allows a nearly three orders of magnitude improvement in both gain and optical power requirements over the only previous all-optical implementation, with 37 dB of gain achieved for only 12 uW of input power. Minor adjustments to parameters allows optical filtering with narrow bandwidth dictated by the mechanical quality factor. Operation at cryogenic temperatures may enable standard quantum limit surpassing measurements and ponderomotive squeezing.Comment: 4 pages, 5 figure

Cavity optoelectromechanical regenerative amplification

Cavity optoelectromechanical regenerative amplification is demonstrated. An optical cavity enhances mechanical transduction, allowing sensitive measurement even for heavy oscillators. A 27.3 MHz mechanical mode of a microtoroid was linewidth narrowed to 6.6\pm1.4 mHz, 30 times smaller than previously achieved with radiation pressure driving in such a system. These results may have applications in areas such as ultrasensitive optomechanical mass spectroscopy

Response to Teladorsagia circumcincta infection in Scottish Blackface lambs with divergent phenotypes for nematode resistance

peer-reviewedThe objective of this study was to identify Scottish Blackface lambs that were at the extremes of the spectrum of resistance to gastrointestinal nematodes and characterise their response to an experimental nematode challenge. Lambs (n = 90) were monitored for faecal egg count (FEC) (2 samples from each of 2 independent natural infections). The most resistant (n = 10) and susceptible (n = 10) individuals were selected and challenged with 30,000 Teladorsagia circumcincta larvae (L3) at 9 months of age. Response to infection was monitored by measuring FEC, plasma pepsinogen, serum antibodies against nematode larval antigens and haematology profile, until necropsy at 71 days post infection. Worm burden, worm fecundity and the level of anti-nematode antibodies in abomasal mucosa were determined at necropsy. FEC was consistently higher in susceptible animals (P < 0.05), validating the selection method. Worm fecundity was significantly reduced in resistant animals (P = 0.03). There was also a significant correlation (r = 0.88; P < 0.001) between the number of adult worms and FEC at slaughter. There was no effect of phenotype (resistance/susceptibility) on plasma pepsinogen or on haematology profile. Phenotype had a significant effect on the level of anti-nematode IgA antibodies in serum (P < 0.01), reflecting a higher peak in resistant animals at day 7 post infection. It is concluded that significant variation in the response to gastrointestinal nematode challenge exists within the Scottish Blackface population with resistant animals displaying significantly lower FEC, lower worm fecundity and higher concentration of anti-nematode IgA antibodies in serum.Kathryn McRae was supported by a Teagasc Walsh fellowship and the Allan and Grace Kay Overseas Scholarship

Social Affect Regulation in University Students During the COVID-19 Pandemic

Given how much time humans spend in social contexts, interest has been growing in socially mediated forms of affect regulation. Historically, though, research on affect regulation has focused on individual forms of regulation, such as cognitive reappraisal. To address this gap, we investigated social affect regulation in university students through an online survey, with a particular focus on social reappraisal. Specifically, we tested whether the frequency with which students communicate with their social contacts is related to how much social reappraisal support they receive from those contacts, and whether social reappraisal support is associated with mental health. Our final sample consisted of 152 undergraduates from across North America who reported on a total of 1,124 social contacts. We consistently found that communication frequency was positively associated with perceived social reappraisal support across several modalities of communication (e.g., text-based, video-based, in-person). However, we observed no associations between levels of social reappraisal support and measures of mental health. This research was part of a preregistered project on social affect regulation in university students in the context of the COVID-19 pandemic (https://osf.io/q7bvw/). Thus, we present findings in relation to this context. These findings underscore that social forms of affect regulation play a significant role in university students’ lives, emphasizing the value of further research into their mechanisms and effects

Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity

Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report the results from a heat treatment study of a large-grain 1.5 GHz single-cell cavity made of "medium purity" Nb. The baseline surface preparation prior to heat treatment consisted of standard buffered chemical polishing. The heat treatment in the range 800 - 1400 C was done in a newly designed vacuum induction furnace. Q0 values of the order of 2x1010 at 2.0 K and peak surface magnetic field (Bp) of 90 mT were achieved reproducibly. A Q0-value of (5+-1)1010 at 2.0 K and Bp = 90 mT was obtained after heat treatment at 1400 C. This is the highest value ever reported at this temperature, frequency and field. Samples heat treated with the cavity at 1400 C were analyzed by secondary ion mass spectrometry, secondary electron microscopy, energy dispersive X-ray, point contact tunneling and X-ray diffraction and revealed a complex surface composition which includes titanium oxide, increased carbon and nitrogen content but reduced hydrogen concentration compared to a non heat-treated sample

Interferometric detection of mode splitting for whispering gallery mode biosensors

Sensors based on whispering gallery mode resonators can detect single nanoparticles and even single molecules. Particles attaching to the resonator induce a doublet in the transmission spectrum which provides a self-referenced detection signal. However, in practice this spectral feature is often obscured by the width of the resonance line which hides the doublet structure. This happens particularly in liquid environments that reduce the effective Q factor of the resonator. In this paper we demonstrate an interferometric set-up that allows the direct detection of the hidden doublet and thus provides a pathway for developing practical sensor applications.Comment: 9 page

Time-delayed entanglement from coherently coupled nonlinear cavities

The output fields of a pair of coherently coupled nonlinear optical cavities are found to exhibit strong optical entanglement. For sufficiently strong coupling time-delayed quantum correlations are observed providing a resource for quantum information protocols such as all-optical quantum memories. A straightforward experimental implementation applicable to whispering gallery mode resonators such as microtoroids is proposed

Undiagnosed diabetes from cross-sectional GP practice data: an approach to identify communities with high likelihood of undiagnosed diabetes

OBJECTIVES To estimate undiagnosed diabetes prevalence from general practitioner (GP) practice data and identify areas with high levels of undiagnosed and diagnosed diabetes. DESIGN Data from the North-West Adelaide Health Survey (NWAHS) were used to develop a model which predicts total diabetes at a small area. This model was then applied to cross-sectional data from general practices to predict the total level of expected diabetes. The difference between total expected and already diagnosed diabetes was defined as undiagnosed diabetes prevalence and was estimated for each small area. The patterns of diagnosed and undiagnosed diabetes were mapped to highlight the areas of high prevalence. SETTING North-West Adelaide, Australia. PARTICIPANTS This study used two population samples-one from the de-identified GP practice data (n=9327 active patients, aged 18 years and over) and another from NWAHS (n=4056, aged 18 years and over). MAIN OUTCOME MEASURES Total diabetes prevalence, diagnosed and undiagnosed diabetes prevalence at GP practice and Statistical Area Level 1. RESULTS Overall, it was estimated that there was one case of undiagnosed diabetes for every 3-4 diagnosed cases among the 9327 active patients analysed. The highest prevalence of diagnosed diabetes was seen in areas of lower socioeconomic status. However, the prevalence of undiagnosed diabetes was substantially higher in the least disadvantaged areas. CONCLUSIONS The method can be used to estimate population prevalence of diabetes from general practices wherever these data are available. This approach both flags the possibility that undiagnosed diabetes may be a problem of less disadvantaged social groups, and provides a tool to identify areas with high levels of unmet need for diabetes care which would enable policy makers to apply geographic targeting of effective interventions