Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

STUDY OF THE Fe3+/Fe2+ RATIO IN NATURAL CHROMITES (Fex, Mg1-x) (Cr1-y-z, Fey, Alz)O4

Cinq chromites naturels, provenant de Madagascar, U.R.S.S., Iran et de l'Afrique du Sud ont été étudiés par spectroscopie Mössbauer dans la région paramagnétique entre 77 K (ou 50 K) et 300 K. Le résultat le plus important est la variation, en fonction de la température, durapport Fe3+/Fe2+ dû à l'effet de saut électronique avec une énergie d'activation dépendant du minerai. Les résultats obtenus nous ont montré que les 5 minéraux peuvent être classés en trois familles, suivant l'énergie d'activation et la gamme de températures dans laquelle se manifeste l'effet de saut électronique. Ces trois familles correspondent aussi à trois formules chimiques différentes proposées par les résultats combinés d'analyse chimique et d'intensité Mössbauer.Five spinel chromites minerals from Madagascar, U.S.S.R., Iran and South Africa were studied by Mössbauer spectroscopy in the paramagnetic region between 77 K (or 50 K) and 300 K. The more important result is the presence of a temperature dependent population Fe3+/Fe2+ ration due to hopping effect with different activation energy for the different minerals. The whole results allowed us to classify the five samples in three main classes of minerals. These are distinguished by a hopping effect manifested at different temperatures and with a different activation energy and correspond to three different chemical formulae proposed by combined chemical analysis and Mössbauer intensities

Processus électroniques dans le tellurure de fer γ

Le choix de la phase haute température du système fer-tellure pour une étude systématique de l’influence de la composition stœchiométrique sur les propriétés semiconductrices des composés d’éléments de transition a été déterminé par les 3 points suivants : son caractère semiconducteur semblait certain, le domaine d’homogénéité de la phase était large et, pour la première fois, un paramagnétisme de Pauli était signalé dans un cristal semiconducteur. Les mesures électriques et optiques s’accordent sur une hauteur de bande interdite de l’ordre de 0,6 eV, avec un niveau d’impuretés accepteur à 0,08 eV au-dessus de la bande de valence. Les mesures magnétiques, par contre, mettent en évidence le paramagnétisme de Pauli d’électrons d entièrement délocalisés, dont le nombre est minimum pour la composition Fe2Te3. La présence d’une bande 3 d possédant un minimum de densité d’états en son milieu et située dans la bande interdite rend compte de cette « composante métallique ». La délocalisation dans la bande 3 d est confirmée par l’étude du déplacement isomérique de la résonance Mössbauer du noyau Fe57 ainsi que celle de la chaleur spécifique électronique du cristal. La première met en évidence, pour la première fois, l’influence des électrons libres sur le déplacement isomérique. On discute enfin de la nature des liaisons interatomiques

STOICHIOMETRY DEPENDENCE OF ZEEMAN HYPERFINE INTERACTIONS IN Fe1+x Ti2(1+x)S4 (x = 0, 0.030, 0.052)

Le rôle de la méthode de préparation du traitement thermique et de la non stoechiométrie sur l'ordre cristallographique et les propriétés magnétiques du chalcogénure ternaire FeTi2S4, a été le sujet de contradictions ces dernières années. Afin de contribuer à l'étude de ces questions, nous avons pensé voir comment les paramètres mentionnés ci-dessus se reflètent dans les spectres Mössbauer. Les résultats obtenus entre 4,2 K et 300 K sont discutés par comparaison aux résultats cristallographiques et magnétiques antérieurs.The role of the method of preparation, of the heat treatment and of the non stoichiometry, on the crystallographic and magnetic ordering of the ternay chalcogenide FeTi2S4 is not well inderstood to date. In order to clarify these questions, or, at least, to give supplementary data for future discussions, we have looked how the parameters mentioned above are reflected in the Mössbauer spectra. The results obtained between 4.2 K and 300 K showed marked differences between stoichiometric and non stoichiometric samples, and small or no differences between the different heat treatments and the different methods of preparation, respectively, and are discussed in terms of crystallographic and magnetic ordering

‘Intellectual’ field: education reformers and conformers

© 2019, Springer Nature Singapore Pte Ltd. This chapter addresses the ‘intellectual’ field and focuses on the higher education sector. The practical experiences of returnees working in Vietnamese universities provide a neat instance of the high-skilled returnee experience, hinging on the dialectic of agency and structure. The chapter first describes the context of universities development in Vietnam and some of the opportunities and challenges that overseas-educated academics may encounter. Drawing on survey and interview data, the next section discusses the utility of overseas-acquired skills, knowledge and attributes across public and private universities. This is followed by accounts of returnees’ experiences in their teaching, research and career pathway in academia. The last part of the empirical discussion draws on the survey results to present returnees’ achieved functionings in terms of job roles, income levels and job satisfaction. The concluding section summarises the key findings and explication of the Sen-Bourdieu concepts of normative agency and situated freedom. It identifies some implications for Vietnamese universities in receiving overseas-educated academics

The influence of carbon on nitrogen substitution in iron ε-phases

Mössbauer spectroscopy of nitrided and carbonitrided iron powders and plates with total interstitial atom contents of between 24 and 33 at% has allowed the variation with composition of the hyperfine magnetic fields of metal atoms with 2 or 3 close interstitial atoms to be determined. Fe atoms with three non-metal nearest neighbours and paramagnetic behaviour have also been detected. Only when the content of non-metal atoms goes beyond 30 at%, do Fe atoms in ε-carbonitrides display higher magnetic fields than in the corresponding ε-nitrides. The lower number of electrons contributed to the iron 3d-orbitals by C atoms than by N atoms is considered the cause of the above phenomenon. The variation of other hyperfine parameters with composition is also discussed

Psychiatric comorbidity in treatment-seeking substance use disorder patients with and without attention deficit hyperactivity disorder: results of the IASP study.

AIMS: To determine comorbidity patterns in treatment-seeking substance use disorder (SUD) patients with and without adult attention deficit hyperactivity disorder (ADHD), with an emphasis on subgroups defined by ADHD subtype, taking into account differences related to gender and primary substance of abuse. DESIGN: Data were obtained from the cross-sectional International ADHD in Substance use disorder Prevalence (IASP) study. SETTING: Forty-seven centres of SUD treatment in 10 countries. PARTICIPANTS: A total of 1205 treatment-seeking SUD patients. MEASUREMENTS: Structured diagnostic assessments were used for all disorders: presence of ADHD was assessed with the Conners' Adult ADHD Diagnostic Interview for DSM-IV (CAADID), the presence of antisocial personality disorder (ASPD), major depression (MD) and (hypo)manic episode (HME) was assessed with the Mini International Neuropsychiatric Interview-Plus (MINI Plus), and the presence of borderline personality disorder (BPD) was assessed with the Structured Clinical Interview for DSM-IV Axis II (SCID II). FINDINGS: The prevalence of DSM-IV adult ADHD in this SUD sample was 13.9%. ASPD [odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.8-4.2], BPD (OR = 7.0, 95% CI = 3.1-15.6 for alcohol; OR = 3.4, 95% CI = 1.8-6.4 for drugs), MD in patients with alcohol as primary substance of abuse (OR = 4.1, 95% CI = 2.1-7.8) and HME (OR = 4.3, 95% CI = 2.1-8.7) were all more prevalent in ADHD+ compared with ADHD- patients (P < 0.001). These results also indicate increased levels of BPD and MD for alcohol compared with drugs as primary substance of abuse. Comorbidity patterns differed between ADHD subtypes with increased MD in the inattentive and combined subtype (P < 0.01), increased HME and ASPD in the hyperactive/impulsive (P < 0.01) and combined subtypes (P < 0.001) and increased BPD in all subtypes (P < 0.001) compared with SUD patients without ADHD. Seventy-five per cent of ADHD patients had at least one additional comorbid disorder compared with 37% of SUD patients without ADHD. CONCLUSIONS: Treatment-seeking substance use disorder patients with attention deficit hyperactivity disorder are at a very high risk for additional externalizing disorders