Spangolite: an s=1/2 maple leaf lattice antiferromagnet?

Spangolite, Cu6Al(SO4)(OH)12Cl.3H2O, is a hydrated layered copper sulphate mineral. The Cu2+ ions of each layer form a systematically depleted triangular lattice which approximates a maple leaf lattice. We present details of the crystal structure, which suggest that in spangolite this lattice actually comprises two species of edge linked trimers with different exchange parameters. However, magnetic susceptibility measurements show that despite the structural trimers, the magnetic properties are dominated by dimerization. The high temperature magnetic moment is strongly reduced below that expected for the six s=1/2 in the unit cell.Comment: Accepted for JPCM Frustrated Magnetism special issue, added reference [5] in replacemen

Selective targeting of activating and inhibitory Smads by distinct WWP2 ubiquitin ligase isoforms differentially modulates TGFβ signalling and EMT

Ubiquitin-dependent mechanisms have emerged as essential regulatory elements controlling cellular levels of Smads and TGFß-dependent biological outputs such as epithelial–mesenchymal transition (EMT). In this study, we identify a HECT E3 ubiquitin ligase known as WWP2 (Full-length WWP2-FL), together with two WWP2 isoforms (N-terminal, WWP2-N; C-terminal WWP2-C), as novel Smad-binding partners. We show that WWP2-FL interacts exclusively with Smad2, Smad3 and Smad7 in the TGFß pathway. Interestingly, the WWP2-N isoform interacts with Smad2 and Smad3, whereas WWP2-C interacts only with Smad7. In addition, WWP2-FL and WWP2-C have a preference for Smad7 based on protein turnover and ubiquitination studies. Unexpectedly, we also find that WWP2-N, which lacks the HECT ubiquitin ligase domain, can also interact with WWP2-FL in a TGFß-regulated manner and activate endogenous WWP2 ubiquitin ligase activity causing degradation of unstimulated Smad2 and Smad3. Consistent with our protein interaction data, overexpression and knockdown approaches reveal that WWP2 isoforms differentially modulate TGFß-dependent transcription and EMT. Finally, we show that selective disruption of WWP2 interactions with inhibitory Smad7 can stabilise Smad7 protein levels and prevent TGFß-induced EMT. Collectively, our data suggest that WWP2-N can stimulate WWP2-FL leading to increased activity against unstimulated Smad2 and Smad3, and that Smad7 is a preferred substrate for WWP2-FL and WWP2-C following prolonged TGFß stimulation. Significantly, this is the first report of an interdependent biological role for distinct HECT E3 ubiquitin ligase isoforms, and highlights an entirely novel regulatory paradigm that selectively limits the level of inhibitory and activating Smads

Evaluating the use of the Child and Adolescent Intellectual Disability Screening Questionnaire (CAIDS-Q) to estimate IQ in children with low intellectual ability

In situations where completing a full intellectual assessment is not possible or desirable the clinician or researcher may require an alternative means of accurately estimating intellectual functioning. There has been limited research in the use of proxy IQ measures in children with an intellectual disability or low IQ. The present study aimed to provide a means of converting total scores from a screening tool (the Child and Adolescent Intellectual Disability Screening Questionnaire: CAIDS-Q) to an estimated IQ. A series of linear regression analyses were conducted on data from 428 children and young people referred to clinical services, where FSIQ was predicted from CAIDS-Q total scores. Analyses were conducted for three age groups between ages 6 and 18 years. The study presents a conversion table for converting CAIDS-Q total scores to estimates of FSIQ, with corresponding 95% prediction intervals to allow the clinician or researcher to estimate FSIQ scores from CAIDS-Q total scores. It is emphasised that, while this conversion may offer a quick means of estimating intellectual functioning in children with a below average IQ, it should be used with caution, especially in children aged between 6 and 8 years old

Even low level of physical activity is associated with reduced mortality among people with metabolic syndrome, a population based study (the HUNT 2 study, Norway)

<p>Abstract</p> <p>Background</p> <p>Low levels of physical activity may increase the risk of developing metabolic syndrome, a cluster of metabolic factors that are associated with the risk of premature death. It has been suggested that physical activity may reduce the impact of factors associated with metabolic syndrome, but it is not known whether physical activity may reduce mortality in people with metabolic syndrome.</p> <p>Methods</p> <p>In a prospective study of 50,339 people, 13,449 had metabolic syndrome at baseline and were followed up for ten years to assess cause-specific mortality. The population was divided into two age groups: those younger than 65 years of age and those older than age 65. Information on their physical activity levels was collected at baseline.</p> <p>Results</p> <p>Metabolic syndrome was associated with higher mortality from all causes (hazard ratio (HR) 1.35, 95% confidence interval (95% CI) 1.20 to 1.52) and from cardiovascular causes (HR 1.78, 95% CI 1.39 to 2.29) in people younger than 65 years old than among other populations. In older people, there was no overall association of metabolic syndrome with mortality. People with metabolic syndrome who reported high levels of physical activity at baseline were at a reduced risk of death from all causes compared to those who reported no physical activity, both in the younger age group (HR 0.52, 95% CI 0.37 to 0.73) and in the older age group (HR 0.59, 95% CI 0.47 to 0.74).</p> <p>Conclusion</p> <p>Among people with metabolic syndrome, physical activity was associated with reduced mortality from all causes and from cardiovascular causes. Compared to inactivity, even low levels of physical activity were associated with reduced mortality.</p

Veterinary students' usage and perception of video teaching resources

<p>Abstract</p> <p>Background</p> <p>The purpose of our study was to use a student-centred approach to develop an online video learning resource (called 'Moo Tube') at the School of Veterinary Medicine and Science, University of Nottingham, UK and also to provide guidance for other academics in the School wishing to develop a similar resource in the future.</p> <p>Methods</p> <p>A focus group in the format of the nominal group technique was used to garner the opinions of 12 undergraduate students (3 from year-1, 4 from year-2 and 5 from year-3). Students generated lists of items in response to key questions, these responses were thematically analysed to generate key themes which were compared between the different year groups. The number of visits to 'Moo Tube' before and after an objective structured practical examination (OSPE) was also analysed to provide data on video usage.</p> <p>Results</p> <p>Students highlighted a number of strengths of video resources which can be grouped into four overarching themes: (1) teaching enhancement, (2) accessibility, (3) technical quality and (4) video content. Of these themes, students rated teaching enhancement and accessibility most highly. Video usage was seen to significantly increase (P < 0.05) prior to an examination and significantly decrease (P < 0.05) following the examination.</p> <p>Conclusions</p> <p>The students had a positive perception of video usage in higher education. Video usage increases prior to practical examinations. Image quality was a greater concern with year-3 students than with either year-1 or 2 students but all groups highlighted the following as important issues: i) good sound quality, ii) accessibility, including location of videos within electronic libraries, and iii) video content. Based on the findings from this study, guidelines are suggested for those developing undergraduate veterinary videos. We believe that many aspects of our list will have resonance in other areas of medicine education and higher education.</p

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration