Note on Invariants of the Weyl Tensor

Algebraically special gravitational fields are described using algebraic and differential invariants of the Weyl tensor. A type III invariant is also given and calculated for Robinson-Trautman spaces.Comment: 3 pages, no figures, corrected expression (12

Rediscovering the Artistic Side of Mathematics

Welcome to the inaugural issue of the LASER, a journal devoted to the problems at the interface of math and art. The terms ’math’ and ’art’ are to be broadly construed to encompass all quantitative sciences and forms of art. The journal’s name, acronym for Linking Art and Science through Education and Research, suggests our interest in the theory, practice and pedagogy of this interdisciplinary subject

The Mathematics of the Harp: Modeling the Classical Instrument and Designing Futuristic Ones

We analyze and model the neck of the classical harp based on the length of the strings, their tension and density. We then use the results to design new and innovative harp shapes by adjusting the parameters of the model

Anthropological Perspectives on Gender Politics in/of Europe

Over the last few decades, the politics of gender and sexuality have turned extremely hostile across Europe. Long fought for rights and antidiscriminatory politics have come under heavy attack, while Gender Studies programs have been banned. In tandem, feminist arguments are being instrumentalized by right-wing movements so as to cement nationalist projects and racist positions. This turmoil regarding the politics of gender in Europe has become even more complex as gender, sexuality, and race find themselves used as markers of both progress and backwardness within the postcolonial, postsocialist European landscape reproducing old and creating new hierarchies within the societies and between them. Based on the 2021 conference “Troubling Gender: New Turbulences in the Politics of Gender in Europe,” organized by the Commission on Gender Research and Queer Anthropology of the German Association for European Ethnology and Empirical Cultural Analyses, this issue of Berliner Blätter hence assembles an array of analytical papers as well as polyvocal written discussions seeking to make sense of these developments as well as of their local and regional articulations and effects. The issue brings together queer/feminist voices and analyses from the Eastern and Western European contexts; furthermore, it examines the possibilities for solidarity across different positionalities and engages with diverse histories of struggle. The issue presents analyses informed by gender and queer theory, as mostly based on ethnographic research, and thus ultimately allows us to better understand the current conjuncture of the politics of gender and sexuality in and of Europe. With this, it partakes in the ongoing feminist and queer struggles to build a better future for all those concerned.Im letzten Jahrzehnt haben sich Politiken rund um Geschlechter und Sexualitätspolitik in ganz Europa äußerst feindselig entwickelt. Erkämpfte Rechte und eine antidiskriminatorische Politik sind massiv unter Beschuss geraten, Studiengänge der Geschlechterforschung wurden verboten. Gleichzeitig werden feministische Argumente von rechtsgerichteten Bewegungen instrumentalisiert, um nationalistische Projekte und rassistische Positionen zu zementieren. Noch weiter kompliziert wird die Situation dadurch, dass Geschlecht, Sexualität und Rasse in der postkolonialen, postsozialistischen europäischen Landschaft als Marker für Fortschritt und Rückständigkeit dienen, wodurch alte Hierarchien innerhalb der Gesellschaften und zwischen ihnen reproduziert und neue geschaffen werden. Ausgehend von der Konferenz „Troubling Gender: Neue Turbulenzen in der Geschlechterpolitik in Europa“, organisiert 2021 von der Kommission für Geschlechterforschung und Queere Anthropologie in der Deutschen Gesellschaft für Europäische Ethnologie und Empirische Kulturwissenschaft (DGEKW), bringt die Ausgabe der Berliner Blätter queere und feministische Stimmen und Analysen aus dem ost- und westeuropäischen Kontext zusammen. Gemeinsam versuchen sie, diese Entwicklungen, ihre lokalen und regionalen Artikulationen und Auswirkungen zu verstehen. Neben den geschlechter- und queertheoretisch fundierten Analysen, die sich größtenteils auf ethnografische Forschungen stützen, ergründen polyvokale, dialogisch geschriebene Beiträge die Möglichkeiten der Solidarität über verschiedene Positionen hinweg und zeigen die verschiedenen Geschichten von gender- und queerpolitischen Kämpfen und Epistemologien in Europa. Die Ausgabe ermöglicht so ein differenziertes Verständnis der aktuellen Situation der Geschlechter- und Sexualitätspolitik in und für Europa und hat damit teil an den laufenden feministischen und queeren Kämpfen um eine bessere Zukunft für alle Beteiligten.Peer Reviewe

A unifying modelling of multiple land degradation pathways in Europe

Land degradation is a complex socio-environmental threat, which generally occurs as multiple concurrent pathways that remain largely unexplored in Europe. Here we present an unprecedented analysis of land multi-degradation in 40 continental countries, using twelve dataset-based processes that were modelled as land degradation convergence and combination pathways in Europe’s agricultural (and arable) environments. Using a Land Multi-degradation Index, we find that up to 27%, 35% and 22% of continental agricultural (~2 million km2) and arable (~1.1 million km2) lands are currently threatened by one, two, and three drivers of degradation, while 10–11% of pan-European agricultural/arable landscapes are cumulatively affected by four and at least five concurrent processes. We also explore the complex pattern of spatially interacting processes, emphasizing the major combinations of land degradation pathways across continental and national boundaries. Our results will enable policymakers to develop knowledge-based strategies for land degradation mitigation and other critical European sustainable development goals

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Wissenschaftliche Begründung der STIKO zur Empfehlung zur 2. COVID-19-Auffrischimpfung mit einem mRNA-Impfstoff für besonders gesundheitlich gefährdete bzw. exponierte Personengruppen

Die STIKO empfihlt nach abgeschlossener COVID-19-Grundimmunisierung und erfolgter 1. Auffrischimpfung eine 2. Auffrischimpfung (frühestens 3 Monate nach der 1. Auffrischimpfung) mit einem mRNA-Impfstoff für ≥ 70-Jährige, BewohnerInnen und Betreute in Einrichtungen der Pflege und für Personen mit Immundefizienz. Ebenfalls empfohlen wird die 2. Auffrischimpfung Tätigen in medizinischen Einrichtungen und Pflegeeinrichtungen, hier jedoch frühestens 6 Monate nach der 1. Auffrischimpfung. In begründeten Einzelfällen kann bei Letztgenannten die 2. Auffrischimpfung auch bereits nach frühestens 3 Monaten erwogen werden.Peer Reviewe

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication