303 research outputs found

    Developing enterprise culture in a northern educational authority in the UK: involving trainee teachers in learning-orientated evaluation

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    In this paper we discuss our use of innovative methods - at least in the context of regeneration evaluation - to help evaluate an enterprise project in northern England, paying particular attention to the involvement of trainee teachers. We discuss the methods used and critically appraise the methods and methodology, present some emerging findings from the trainee teachers strand and conclude by discussing the place of what might be termed 'learning-orientated evaluation' in relation to the currently dominant output-focussed evaluation paradigm.</p

    Constraint-based, Single-point Approximate Kinetic Energy Functionals

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    We present a substantial extension of our constraint-based approach for development of orbital-free (OF) kinetic-energy (KE) density functionals intended for the calculation of quantum-mechanical forces in multi-scale molecular dynamics simulations. Suitability for realistic system simulations requires that the OF-KE functional yield accurate forces on the nuclei yet be relatively simple. We therefore require that the functionals be based on DFT constraints, local, dependent upon a small number of parameters fitted to a training set of limited size, and applicable beyond the scope of the training set. Our previous "modified conjoint" generalized-gradient-type functionals were constrained to producing a positive-definite Pauli potential. Though distinctly better than several published GGA-type functionals in that they gave semi-quantitative agreement with Born-Oppenheimer forces from full Kohn-Sham results, those modified conjoint functionals suffer from unphysical singularities at the nuclei. Here we show how to remove such singularities by introducing higher-order density derivatives. We give a simple illustration of such a functional used for the dissociation energy as a function of bond length for selected molecules.Comment: 16 pages, 9 figures, 2 tables, submitted to Phys. Rev.

    Unconventional quantum Hall effect and Berry’s phase 2pi in bilayer graphene.

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    There are known two distinct types of the integer quantum Hall effect. One is the conventional quantum Hall effect, characteristic of two-dimensional semiconductor systems, and the other is its relativistic counterpart recently observed in graphene, where charge carriers mimic Dirac fermions characterized by Berry’s phase pi, which results in a shifted positions of Hall plateaus. Here we report a third type of the integer quantum Hall effect. Charge carriers in bilayer graphene have a parabolic energy spectrum but are chiral and exhibit Berry’s phase 2pi affecting their quantum dynamics. The Landau quantization of these fermions results in plateaus in Hall conductivity at standard integer positions but the last (zero-level) plateau is missing. The zero-level anomaly is accompanied by metallic conductivity in the limit of low concentrations and high magnetic fields, in stark contrast to the conventional, insulating behavior in this regime. The revealed chiral fermions have no known analogues and present an intriguing case for quantum-mechanical studies

    Association of Cumulative Social Risk and Social Support With Receipt of Chemotherapy Among Patients With Advanced Colorectal Cancer

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    Importance: Approximately 38% of patients with advanced colorectal cancer do not receive chemotherapy. Objective: To determine whether cumulative social risk (ie, multiple co-occurring sociodemographic risk factors) is associated with lower receipt of chemotherapy among patients with advanced colorectal cancer and whether social support would moderate this association. Design, Setting, and Participants: This cross-sectional, population-based, mailed survey study was conducted from 2012 to 2014. Participants were recruited between 2011 and 2014 from all adults within 1 year after diagnosis of stage III colorectal cancer in the Detroit, Michigan, and State of Georgia Surveillance, Epidemiology, End-Results cancer registries. Patients were eligible if they were aged 18 years or older, had undergone surgery 4 or more months ago, did not have stage IV cancer, and resided in the registry catchment areas. Data analyses were conducted from March 2017 to April 2021. Main Outcomes and Measures: The primary outcome was receipt of chemotherapy. Cumulative social risk represented a sum of 8 risk factors with the potential to drain resources from participants\u27 cancer treatment (marital status, employment, annual income, health insurance, comorbidities, health literacy, adult caregiving, and perceived discrimination). Social support was operationalized as emotional support related to colorectal cancer diagnosis. Results: Surveys were mailed to 1909 eligible patients; 1301 completed the survey (response rate, 68%). A total of 1087 participants with complete data for key variables were included in the sample (503 women [46%]; mean [SD] age, 64 [13] years). Participants with 3 or more risk factors were less likely to receive chemotherapy than participants with 0 risk factors (3 factors, odds ratio [OR], 0.48 [95% CI, 0.26-0.87]; 4 factors, OR, 0.41 [95% CI, 0.21-0.78]; 5 factors, OR, 0.42 [95% CI, 0.20-0.87]; ≥6 factors, OR, 0.22 [95% CI, 0.09-0.55]). Participants with 2 or more support sources had higher odds of undergoing chemotherapy than those without social support (2 sources, OR, 3.05 [95% CI, 1.36-6.85]; 3 sources, OR, 3.24 [95% CI, 1.48-7.08]; 4 sources, OR, 3.69 [95% CI, 1.71-7.97]; 5 sources, OR, 4.40 [95% CI, 1.98-9.75]; ≥6 sources, OR 5.95 [95% CI, 2.58-13.74]). Within each social support level, participants were less likely to receive chemotherapy as cumulative social risk increased. Conclusions and Relevance: Cumulative social risk was associated with reduced receipt of chemotherapy. These associations were mitigated by social support. Assessing cumulative social risk may identify patients with colorectal cancer who are at higher risk for omitting chemotherapy who can be targeted for support programs to address social disadvantage and increase social support

    The relationship between left ventricular wall thickness, myocardial shortening and ejection fraction in hypertensive heart disease:insights from cardiac magnetic resonance: LVH independently augments EF in hypertension

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    Hypertensive heart disease is often associated with a preserved left ventricular ejection fraction despite impaired myocardial shortening. The authors investigated this paradox in 55 hypertensive patients (52±13 years, 58% male) and 32 age‐ and sex‐matched normotensive control patients (49±11 years, 56% male) who underwent cardiac magnetic resonance imaging at 1.5T. Long‐axis shortening (R=0.62), midwall fractional shortening (R=0.68), and radial strain (R=0.48) all decreased (P<.001) as end‐diastolic wall thickness increased. However, absolute wall thickening (defined as end‐systolic minus end‐diastolic wall thickness) was maintained, despite the reduced myocardial shortening. Absolute wall thickening correlated with ejection fraction (R=0.70, P<.0001). In multiple linear regression analysis, increasing wall thickness by 1 mm independently increased ejection fraction by 3.43 percentage points (adjusted β‐coefficient: 3.43 [2.60–4.26], P<.0001). Increasing end‐diastolic wall thickness augments ejection fraction through preservation of absolute wall thickening. Left ventricular ejection fraction should not be used in patients with hypertensive heart disease without correction for degree of hypertrophy

    Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

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    Background People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID. Methods In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity. Findings We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40–2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28–2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94–1·65) and a 21% increase in HCV (1·21, 1·02–1·43) acquisition risk. Interpretation Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID

    Usage of low dead space syringes and association with hepatitis C prevalence amongst people who inject drugs in the UK

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    IntroductionSyringes with attached needles (low dead space syringes [LDSS]) retain far less blood following injection than syringes with detachable needles (high dead space syringes [HDSS]). People who inject drugs (PWID) who share needles/syringes may be less likely to acquire Hepatitis C virus (HCV) infection using LDSS, compared with HDSS, but data are limited.MethodsUtilising drug behaviour and HCV antibody testing data from the UK 2014/2015 Unlinked Anonymous Monitoring Survey of PWID, we calculated the percentage of syringes used in the past month that were LDSS. We investigated which injecting characteristics and demographic factors were associated with 100% LDSS (against 0-99%) usage, and whether 100% LDSS use was associated with antibody HCV-status, after adjusting for confounders.ResultOf 2,174 participants, 55% always used LDSS, 27% always used HDSS, and 17% used both LDSS and HDSS. PWID that had injected into their groin during the past month were unlikely to use LDSS, adjusted odds ratio (aOR) 0.14 (95% confidence interval 0.11-0.17), compared to those not using the groin. Those injecting crack were less likely to use LDSS than those not, aOR 0.79 (0.63-0.98). Polydrug use was negatively associated with LDSS use, aOR 0.88 (0.79-0.98) per additional drug. LDSS use was associated with lower prevalent HCV among all PWID (aOR 0.77, [0.64-0.93]), which was stronger among recent initiates (aOR 0.53 [0.30-0.94]) than among experienced PWID (aOR 0.81 [0.66-0.99]).DiscussionPeople who inject into their groin were less likely to use LDSS. Exclusive LDSS use was associated with lower prevalence of HCV amongst PWID that started injecting recently, suggesting LDSS use is protective against HCV

    Association of results of four lateral flow antibody tests with subsequent SARS-CoV-2 infection

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine coverage remains incomplete, being only 15% in low-income countries. Rapid point-of-care tests predicting SARS-CoV-2 infection susceptibility in the unvaccinated may assist in risk management and vaccine prioritization. We conducted a prospective cohort study in 2,826 participants working in hospitals and Fire and Police services in England, UK, during the pandemic (ISRCTN5660922). Plasma taken at recruitment in June 2020 was tested using four lateral flow immunoassay (LFIA) devices and two laboratory immunoassays detecting antibodies against SARS-CoV-2 (UK Rapid Test Consortium’s AbC-19 rapid test, OrientGene COVID IgG/IgM rapid test cassette, SureScreen COVID-19 rapid test cassette, and Biomerica COVID-19 IgG/IgM rapid test; Roche N and Euroimmun S laboratory assays). We monitored participants for microbiologically confirmed SARS-CoV-2 infection for 200 days. We estimated associations between test results at baseline and subsequent infection, using Poisson regression models adjusted for baseline demographic risk factors for SARS-CoV-2 exposure. Positive IgG results on each of the four LFIAs were associated with lower rates of subsequent infection with adjusted incidence rate ratios (aIRRs) of 0.00 (95% confidence interval, 0.00 to 0.01), 0.03 (0.02 to 0.05), 0.07 (0.05 to 0.10), and 0.09 (0.07 to 0.12), respectively. The protective association was strongest for AbC-19 and SureScreen. The aIRR for the laboratory Roche N antibody assay at the manufacturer-recommended threshold was similar to those of the two best performing LFIAs at 0.03 (0.01 to 0.10). Lateral flow devices measuring SARS-CoV-2 IgG predicted disease risk in unvaccinated individuals over a 200-day follow-up. The association of some LFIAs with subsequent infection was similar to laboratory immunoassays. IMPORTANCE Previous research has demonstrated an association between the detection of antibodies to SARS-CoV-2 following natural infection and protection from subsequent symptomatic SARS-CoV-2 infection. Lateral flow immunoassays (LFIAs) detecting anti-SARS-CoV-2 IgG are a cheap, readily deployed technology that has been used on a large scale in population screening programs, yet no studies have investigated whether LFIA results are associated with subsequent SARS-CoV-2 infection. In a prospective cohort study of 2,826 United Kingdom key workers, we found positivity in lateral flow test results had a strong negative association with subsequent SARS-CoV-2 infection within 200 days in an unvaccinated population. Positivity on more-specific but less-sensitive tests was associated with a markedly decreased rate of disease; protection associated with testing positive using more sensitive devices detecting lower levels of anti-SARS-CoV-2 IgG was more modest. Lateral flow tests with high specificity may have a role in estimation of SARS-CoV-2 disease risk in unvaccinated populations
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