The rate of thermal dissociation of direnzyl

1) The most recent work on the pyrolysis of dibenzyl suggested that a thermal equilibrium:- PhCH₂CH₂Ph == 2 PhCH₂- was set up as a preliminary to decomposition. The aim of this research was to test this idea by heating mixtures of PhCH₂CH₂Ph (M.W. 182) and PhCD₂CD₂Ph (M.W. 186) and following mass spectrometrically the growth of PhCH₂CH₂Ph (M.W. 184) formed by radical recombination. 2) A four stage synthesis of deuterated dibenzyl was developed and used to prepare dibenzyl of 95% isotopic purity with the composition:- PhCD₂CD₂Ph, 81%; PhCD₂CDHPh, 18 %; PhCDHCDHPh, 1%. PhCH₂CD₂Ph was synthesized by the same sequence of reactions. 3) In order to provide the necessary experimental equipment, the following items have been developed and constructed and descriptions of them are given in this Thesis:- a) a 2 litre reaction vessel with an electronically controlled furnace was arranged with a gas circulating system feeding the inlet of a mass spectrometer; b) an existing mass spectrometer was extensively modified in order to give resolution of 1 in 200:- i) the spectrometer tube was stiffened and accurately re-aligned; ii) the ion collector unit was made detachable and its construction improved; iii) a new ion source was designed and built to the required high accuracy; iv) a new scanning unit was built for variation of the magnetic field. 4) The rate of formation of PhCH₂CD₂Ph was followed in mixtures of PhCH₂CD₂Ph and PhCD₂CD₂Ph at pressures of 0.08 to 0.66 mm. in the reaction vessel, and at pressure up to 142 mm. in sealed tubes, using temperatures between 400° and 500°C. Data were also obtained on the rate of decomposition of PhCH₂CH₂Ph alone in similar systems. 5) The rate of radical exchange was found to be first order, independent of surface and of pressure of added A, N₂, D₂, and O₂. The decomposition reaction was shown to be 1.5 order at low pressures, and tended to first order at high pressures. At lower pressures it was much slower than the radical exchange. 6) A rate equation for radical exchange in terms of the rate of dissociation of dibenzyl, making due allowance for the simultaneous decomposition of dibenzyl has been developed and applied in the lower pressure region where exchange was of major importance. It gives:- kf sec⁻¹ = 10 ¹⁴.⁰³ exp -6000/RT 7) The energy of activation in 6) has been identified with D(PhCH₂-CD₂Ph) in dibenzyl. This value has been discussed in relation to current data on the heat of formation of the benzyl radical and bond dissociation energies in benzyl compounds, notably D(PhCH₂-H) in toluene. 8) The energy of activation for the decomposition was found to be 47 kcal and the nature and proportions of the reaction products were established and compared with previous work. The proportions of side-chain deuterated toluenes formed were consistent with a deuterium isotope effect of 2 or less, and with toluene being made by the abstraction of hydrogen from the central carbon atoms of dibenzyl by benzyl radicals. Benzyl radicals were also shown to react with deuterium to form toluene

An inconvenient dissident: human rights activism in the case of Julian Assange

The article is based on investigations by two branches of the United Nations Human Rights Council into the treatment of the whistleblower journalist, Julian Assange – the UN Working Group on Arbitrary Detention and The UN Special Rapporteur on Torture. The UN investigations analysed for this ‘Acting Up’ article show that Julian Assange is an inconvenient dissident, who has been subjected to persecution by liberal democracies rather than authoritarian regimes. Previous research into whistleblowing has highlighted the courage and risks taken by individual whistleblowers in speaking truth to power however, this case highlights a different facet of speaking truth to power which shows how lawyers, activists and other professionals often refuse to do this because of the professional costs of speaking up for an apparently toxic individual. This article argues that the UN investigations have built a ‘counter-archive’ of suppressed facts about the case, which challenges the ‘collective amnesia’ of the public discourse. This case demonstrates that speaking truth to power requires not only individual courage but the active support of inconvenient dissidents, who lack other civil society support

Changing Patterns of Human Campylobacteriosis, England and Wales, 1990–2007

To explore hypotheses for age-related changes in the incidence of Campylobacter infections in England and Wales during 1990–2007, we analyzed electronic laboratory data. Disease incidence was reduced among children, and the greatest increase in risk was for those >60 years of age. Risk factors for campylobacteriosis in the elderly population should be identified

Towards an Open Infrastructure for Relating Scholarly Assets.

Discovery of useful relationships between scholarly assets on the web is challenging, both in terms generating the right metadata around the assets, and in connecting all relevant digital entities in chain of provenance accessible to the whole community. This paper reports the development of a framework and tools enabling scholarly asset relationships to be expressed in a standard and open way, illustrated with use-cases of discovering new knowledge across cohort studies. The framework uses Research Objects for aggregation, distributed databases for storage, and distributed ledgers for provenance. Our proposal avoids management by a single central platform or organization, instead leveraging the use of existing resources and platforms across natural partnerships. Our proposed infrastructure will support a wide range of users from system administrators to researchers

International consensus on standard outcome measures for neurodevelopmental disorders: A consensus statement

Importance: The use of evidence-based standardized outcome measures is increasingly recognized as key to guiding clinical decision-making in mental health. Implementation of these measures into clinical practice has been hampered by lack of clarity on what to measure and how to do this in a reliable and standardized way. Objective: To develop a core set of outcome measures for specific neurodevelopmental disorders (NDDs), such as attention-deficit/hyperactivity disorder (ADHD), communication disorders, specific learning disorders, and motor disorders, that may be used across a range of geographic and cultural settings. Evidence Review: An international working group composed of clinical and research experts and service users (n = 27) was convened to develop a standard core set of accessible, valid, and reliable outcome measures for children and adolescents with NDDs. The working group participated in 9 video conference calls and 8 surveys between March 1, 2021, and June 30, 2022. A modified Delphi approach defined the scope, outcomes, included measures, case-mix variables, and measurement time points. After development, the NDD set was distributed to professionals and service users for open review, feedback, and external validation. Findings: The final set recommends measuring 12 outcomes across 3 key domains: (1) core symptoms related to the diagnosis; (2) impact, functioning, and quality of life; and (3) common coexisting problems. The following 14 measures should be administered at least every 6 months to monitor these outcomes: ADHD Rating Scale 5, Vanderbilt ADHD Diagnostic Rating Scale, or Swanson, Nolan, and Pelham Rating Scale IV; Affective Reactivity Index; Children’s Communication Checklist 2; Colorado Learning Disabilities Questionnaire; Children’s Sleep Habits Questionnaire; Developmental-Disability Children’s Global Assessment Scale; Developmental Coordination Disorder Questionnaire; Family Strain Index; Intelligibility in Context Scale; Vineland Adaptive Behavior Scale or Repetitive Behavior Scale–Revised and Social Responsiveness Scale; Revised Child Anxiety and Depression Scales; and Yale Global Tic Severity Scale. The external review survey was completed by 32 professionals and 40 service users. The NDD set items were endorsed by more than 70% of professionals and service users in the open review survey. Conclusions and Relevance: The NDD set covers outcomes of most concern to patients and caregivers. Use of the NDD set has the potential to improve clinical practice and research

Returning a lost process by reintroducing a locally extinct digging marsupial

The eastern bettong (Bettongia gaimardi), a medium-sized digging marsupial, was reintroduced to a predator-free reserve after 100 years of absence from the Australian mainland. The bettong may have the potential to restore temperate woodlands degraded by a history of livestock grazing, by creating numerous small disturbances by digging. We investigated the digging capacity of the bettong and compared this to extant fauna, to answer the first key question of whether this species could be considered an ecosystem engineer, and ultimately if it has the capacity to restore lost ecological processes. We found that eastern bettongs were frequent diggers and, at a density of 0.3–0.4 animals ha−1, accounted for over half the total foraging pits observed (55%), with echidnas (Tachyglossus aculeatus), birds and feral rabbits (Oryctolagus cuniculus) accounting for the rest. We estimated that the population of bettongs present dug 985 kg of soil per ha per year in our study area. Bettongs dug more where available phosphorus was higher, where there was greater basal area of Acacia spp. and where kangaroo grazing was less. There was no effect on digging of eucalypt stem density or volume of logs on the ground. While bettong digging activity was more frequent under trees, digging also occurred in open grassland, and bettongs were the only species observed to dig in scalds (areas where topsoil has eroded to the B Horizon). These results highlight the potential for bettongs to enhance soil processes in a way not demonstrated by the existing fauna (native birds and echidna), and introduced rabbit

New species longevity record for the northern quahog (=hard clam), Mercenaria mercenaria

Author Posting. © National Shellfisheries Association, 2011. This article is posted here by permission of National Shellfisheries Association for personal use, not for redistribution. The definitive version was published in Journal of Shellfish Research 30 (2011): 35-38, doi:10.2983/035.030.0106.Twenty-two large shells (>90 mm shell height) from a sample of live collected hard shell clams, Mercenaria mercenaria, from Buzzards Bay, Woods Hole, Cape Cod, MA, were subjected to sclerochronological analysis. Annually resolved growth lines in the hinge region and margin of the shell were identified and counted; the age of the oldest clam shell was determined to be at least 106 y. This age represents a considerable increase in the known maximum life span for M. mercenaria, more than doubling the maximum recorded life span of the species (46 y). More than 85% of the clam shells aged had more than 46 annual increments, the previous known maximum life span for the species. In this article we present growth rate and growth performance indicators (the overall growth performance and phi prime) for this record-breaking population of M. mercenaria. Recently discovered models of aging require accurate age records and growth parameters for bivalve populations if they are to be utilized to their full potential.This work was supported by grants from the American Diabetes Association (to Z. U.), American Federation for Aging Research (to A. C.), the University of Oklahoma College of Medicine Alumni Association (to A. C.), the BBSRC (to C. A. R.),the National Institutes of Health (AT006526 and HL077256 to Z. U.; AG022873 and AG025063 to S. N. A.), and the DFG Cluster of Excellence ‘‘Future Ocean’’ (to E. P.)

COVID-19 in children: analysis of the first pandemic peak in England.

OBJECTIVES: To assess disease trends, testing practices, community surveillance, case-fatality and excess deaths in children as compared with adults during the first pandemic peak in England. SETTING: England. PARTICIPANTS: Children with COVID-19 between January and May 2020. MAIN OUTCOME MEASURES: Trends in confirmed COVID-19 cases, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity rates in children compared with adults; community prevalence of SARS-CoV-2 in children with acute respiratory infection (ARI) compared with adults, case-fatality rate in children with confirmed COVID-19 and excess childhood deaths compared with the previous 5 years. RESULTS: Children represented 1.1% (1,408/129,704) of SARS-CoV-2 positive cases between 16 January 2020 and 3 May 2020. In total, 540 305 people were tested for SARS-COV-2 and 129,704 (24.0%) were positive. In children aged <16 years, 35,200 tests were performed and 1408 (4.0%) were positive for SARS-CoV-2, compared to 19.1%-34.9% adults. Childhood cases increased from mid-March and peaked on 11 April before declining. Among 2,961 individuals presenting with ARI in primary care, 351 were children and 10 (2.8%) were positive compared with 9.3%-45.5% in adults. Eight children died and four (case-fatality rate, 0.3%; 95% CI 0.07% to 0.7%) were due to COVID-19. We found no evidence of excess mortality in children. CONCLUSIONS: Children accounted for a very small proportion of confirmed cases despite the large numbers of children tested. SARS-CoV-2 positivity was low even in children with ARI. Our findings provide further evidence against the role of children in infection and transmission of SARS-CoV-2

Antibody correlates of protection from SARS-CoV-2 reinfection prior to vaccination : a nested case-control within the SIREN study

Funding: This study was supported by the U.K. Health Security Agency, the U.K. Department of Health and Social Care (with contributions from the governments in Northern Ireland, Wales, and Scotland), the National Institute for Health Research, and grant from the UK Medical Research Council (grant number MR/W02067X/1). This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (CC2087, CC1283), the UK Medical Research Council (CC2087, CC1283), and the Wellcome Trust (CC2087, CC1283).Objectives To investigate serological differences between SARS-CoV-2 reinfection cases and contemporary controls, to identify antibody correlates of protection against reinfection. Methods We performed a case-control study, comparing reinfection cases with singly infected individuals pre-vaccination, matched by gender, age, region and timing of first infection. Serum samples were tested for anti-SARS-CoV-2 spike (anti-S), anti-SARS-CoV-2 nucleocapsid (anti-N), live virus microneutralisation (LV-N) and pseudovirus microneutralisation (PV-N). Results were analysed using fixed effect linear regression and fitted into conditional logistic regression models. Results We identified 23 cases and 92 controls. First infections occurred before November 2020; reinfections occurred before February 2021, pre-vaccination. Anti-S levels, LV-N and PV-N titres were significantly lower among cases; no difference was found for anti-N levels. Increasing anti-S levels were associated with reduced risk of reinfection (OR 0·63, CI 0·47-0·85), but no association for anti-N levels (OR 0·88, CI 0·73-1·05). Titres >40 were correlated with protection against reinfection for LV-N Wuhan (OR 0·02, CI 0·001–0·31) and LV-N Alpha (OR 0·07, CI 0·009–0·62). For PV-N, titres >100 were associated with protection against Wuhan (OR 0·14, CI 0·03–0·64) and Alpha (0·06, CI 0·008–0·40). Conclusions Before vaccination, protection against SARS-CoV-2 reinfection was directly correlated with anti-S levels, PV-N and LV-N titres, but not with anti-N levels. Detectable LV-N titres were sufficient for protection, whilst PV-N titres >100 were required for a protective effect. Trial registration number ISRCTN11041050Publisher PDFPeer reviewe

The Scottish Early Rheumatoid Arthritis (SERA) Study:an inception cohort and biobank

Background: The Scottish Early Rheumatoid Arthritis (SERA) study is an inception cohort of rheumatoid (RA) and undifferentiated arthritis (UA) patients that aims to provide a contemporary description of phenotype and outcome and facilitate discovery of phenotypic and prognostic biomarkers Methods: Demographic and clinical outcome data are collected from newly diagnosed RA/UA patients every 6 months from around Scotland. Health service utilization data is acquired from Information Services Division, NHS National Services Scotland. Plain radiographs of hands and feet are collected at baseline and 12 months. Additional samples of whole blood, plasma, serum and filtered urine are collected at baseline, 6 and 12 months Results: Results are available for 1073 patients; at baseline, 76 % were classified as RA and 24 % as UA. Median time from onset to first review was 163 days (IQR97-323). Methotrexate was first-line DMARD for 75 % patients. Disease activity, functional ability and health-related quality of life improved significantly between baseline and 24 months, however the proportion in any employment fell (51 to 38 %, p = 0.0005). 24 % patients reported symptoms of anxiety and/or depression at baseline. 35/391 (9 %) patients exhibited rapid radiographic progression after 12 months. The SERA Biobank has accrued 60,612 samples Conclusions: In routine care, newly diagnosed RA/UA patients experience significant improvements in disease activity, functional ability and health-related quality of life but have high rates of psychiatric symptoms and declining employment rates. The co-existence of a multi-domain description of phenotype and a comprehensive biobank will facilitate multi-platform translational research to identify predictive markers of phenotype and prognosis