On the existence of a Bose Metal at T=0

This paper aims to justify, at a microscopic level, the existence of a two-dimensional Bose metal, i.e. a metallic phase made out of Cooper pairs at T=0. To this end, we consider the physics of quantum phase fluctuations in (granular) superconductors in the absence of disorder and emphasise the role of two order parameters in the problem, viz. phase order and charge order. We focus on the 2-d Bose Hubbard model in the limit of very large fillings, i.e. a 2-d array of Josephson junctions. We find that the algebra of phase fluctuations is that of the Euclidean group $E_{2}$ in this limit, and show that the model is equivalent to two coupled XY models in (2+1)-d, one corresponding to the phase degrees of freedom, and the other the charge degrees of freedom. The Bose metal, then, is the phase in which both these degrees of freedom are disordered(as a result of quantum frustration). We analyse the model in terms of its topological excitations and suggest that there is a strong indication that this state represents a surface of critical points, akin to the gapless spin liquid states. We find a remarkable consistency of this scenario with certain low-T_c thin film experiments.Comment: 16 pages, 2 figure

Attitudes towards young people who self-harm: age, an influencing factor

Aim: To determine the attitudes of emergency care staff towards young people (aged 12–18 years) who self-harm and to gain an understanding of the basis of attitudes that exist. Background: Young people frequently attend emergency services following self-harm; it is unclear whether being a young person influences attitudes held. Design: Mixed methods using a triangulation convergent design. Methods: Survey of 143 staff members from four accident & emergency departments and one ambulance service. Semi-structured interviews with seven children's A&E nurses and five ambulance personnel from the same locality. Data were collected during 2010. Results/Findings: Pearson's product moment correlation coefficient confirmed a strong positive correlation between scores on the two scales used to measure attitudes; paired samples t-test revealed a statistically significant difference in scores across the scales; practitioners held more positive attitudes towards young people who self-harmed than young people per se. Both data sets confirmed the presence of ambivalence and ambiguity in attitudes held. The qualitative data revealed that because of their age and immaturity young people were not held responsible for their self-harming behaviours. Being young did though influence subsequent admission, with particular difficulty in securing admission for those aged 16–17 reported. Conclusion: Age is a factor in shaping practitioners' attitudes; age also directs and influences a young person's journey through emergency care, although due to ambiguity there is inconsistency in determining where those aged 16–17 years of age fit

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) aims to ‘prevent extinctions of known threatened species’. To measure its success, we used a Delphi expert elicitation method to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993 - 2020 (the lifetime of the CBD) and 2010 - 2020 (the timing of Aichi Target 12). We found that conservation prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and 2–7 mammal extinctions since 2010. Many remain highly threatened, and may still become extinct in the near future. Nonetheless, given that ten bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of the CBD) and 2010–2020 (the timing of Aichi Target 12). We found that conservation action prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and two to seven mammal extinctions since 2010. Many remain highly threatened and may still become extinct. Considering that 10 bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions.https://wileyonlinelibrary.com/journal/conlMammal Research Institut

Three short-period Jupiters from TESS: HIP 65Ab, TOI-157b, and TOI-169b

We report the confirmation and mass determination of three hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HIP 65Ab (TOI-129, TIC-201248411) is an ultra-short-period Jupiter orbiting a bright (V = 11.1 mag) K4-dwarf every 0.98 days. It is a massive 3.213 ± 0.078 MJ planet in a grazing transit configuration with an impact parameter of b = 1.17-0.08+0.10. As a result the radius is poorly constrained, 2.03-0.49+0.61RJ. The planet's distance to its host star is less than twice the separation at which it would be destroyed by Roche lobe overflow. It is expected to spiral into HIP 65A on a timescale ranging from 80 Myr to a few gigayears, assuming a reduced tidal dissipation quality factor of Qs′ = 107 - 109. We performed a full phase-curve analysis of the TESS data and detected both illumination- and ellipsoidal variations as well as Doppler boosting. HIP 65A is part of a binary stellar system, with HIP 65B separated by 269 AU (3.95 arcsec on sky). TOI-157b (TIC 140691463) is a typical hot Jupiter with a mass of 1.18 ± 0.13 MJ and a radius of 1.29 ± 0.02 RJ. It has a period of 2.08 days, which corresponds to a separation of just 0.03 AU. This makes TOI-157 an interesting system, as the host star is an evolved G9 sub-giant star (V = 12.7). TOI-169b (TIC 183120439) is a bloated Jupiter orbiting a V = 12.4 G-type star. It has a mass of 0.79 ±0.06 MJ and a radius of 1.09-0.05+0.08RJ. Despite having the longest orbital period (P = 2.26 days) of the three planets, TOI-169b receives the most irradiation and is situated on the edge of the Neptune desert. All three host stars are metal rich with [Fe / H] ranging from 0.18 to0.24

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

THE EFFECT OF ELECTIVE CATARACT EXTRACTION BY PHACOEMULSIFICATION IN EYES WITH VITREOMACULAR TRACTION SYNDROME

PURPOSE: To evaluate the effect of cataract extraction (CE) by phacoemulsification on the vitreomacular interface (VMI) of eyes with preexisting vitreomacular traction (VMT). METHODS: Retrospective, observational case series. Patients with VMT who elected to proceed with CE, before any vitreoretinal intervention, were studied. Eyes with at least a 12-month follow-up period were included. The status of the vitreomacular adhesion at different time points was assessed using spectral-domain optical coherence tomography. The best-corrected visual acuity was recorded at different time points. Other macular and systemic comorbidities were documented. RESULTS: Fifteen eyes from 15 phakic patients with symptomatic VMT were included. Six of them were male subjects. Seven patients had diabetes mellitus and two of them also had nonproliferative diabetic retinopathy. The preoperative macular comorbidities included macular hole in six eyes (Stage 1 in 3 eyes and Stage 2 or 3 in another 3 eyes), epiretinal membrane in five eyes, and cystoid macular edema in four eyes. After uncomplicated CE, the VMT was released in 5 eyes, whereas in 10 eyes, CE did not significantly change the status of the vitreomacular adhesion. Three of 3 eyes with preexisting full-thickness macular hole (Stage 2 or 3 macular hole) were found to have Stage 4 macular hole shortly after CE. In seven of seven patients with diabetes mellitus, the status of the vitreomacular interface did not change after CE. Eventually, 7 of 15 patients underwent additional pars plana vitrectomy. Compared with the baseline vision, and vision before other interventions, the visual acuity after CE improved in 5 patients, remained unchanged in 7 patients, and decreased in the 3 patients with Stage 2 or 3 macular hole. The mean preoperative and early postoperative visual acuity was 20/59 and 20/68, respectively (P &gt; 0.05). CONCLUSION: The effect of CE in phakic eyes with known VMT varies significantly. In the current case series, every eye with VMT and Stage 2 or 3 macular hole ended up with Stage 4 macular hole, although the VMT did not change significantly in the eyes of diabetic patients. Studies with larger sample size are needed to further elucidate the impact of elective CE on VMT