Constraining the parameter space of comet simulation experiments

Our interpretation of the data returned by Rosetta and other cometary missions is based on the predictions of theoretical models and the results of laboratory experiments. For example, Kossacki et al. (2015) showed that 67P's surface hardness reported by Spohn et al. (2015) can be explained by sintering. The present work supports Rosetta's observations by investigating the hardening process of the near-surface layers and the change in surface morphology during insolation. In order to create as simple an analogue as possible our sample consists of pure, porous H2O ice and carbon black particles. The observations suggest that translucence of the near-surface ice is important for enabling subsurface hardening. As an end product of our experiments we also obtained carbon agglomerates with some residual strength

Hardness and Yield Strength of CO2 Ice Under Martian Temperature Conditions

Although ice fracturing and deformation is key to understanding some of the landforms encountered in the high-latitude regions on Mars and on other icy bodies in the solar system, little is known about the mechanical characteristics of CO2 ice. We have measured the hardness of solid CO2 ice directly in the laboratory with a Leeb hardness tester and calculated the corresponding yield strength. We have also measured the hardness of water ice by the same method, confirming previous work. Our results indicate that CO2 ice is slightly weaker, ranging between Leeb ∼200 and 400 (∼10 and 30 MPa yield strength, assuming only plastic deformation and no strain hardening during the experiment), for typical Martian temperatures. Our results can be used for models of CO2 ice rupture (depending on the deformation timescales) explaining surface processes on Mars and solar system icy bodies

A Literature Review Exploring the use of Programming in Mathematics Education

Programming is now included in mathematics curricula in several countries; thus, the purpose of this literature review is to determine the research-based justifications for these educational decisions. From a selection of relevant articles, 15 articles were identified and analyzed, each of which had varying study types, themes, and designs. Three themes from the studies were identified: the motivation to learn mathematics, student performance in mathematics, and the collaboration between students and the changed role of the teacher. It was found that in certain circumstances, including programming in mathematics education could improve student motivation to learn mathematics and improve student performance in mathematics. To gain a better understanding of the potential of programming in mathematics education, the entire collective learning process should be considered by discussing the roles of the teacher and the collaboration between students as part of these roles.publishedVersio

A Simple Way of Simulating Insolation on a Rotating Body with a Commercial Solar Simulator

The surfaces of all solid bodies in the solar system, planets, moons, comets and asteroids, experience short-term temporal variations of solar irradiation which depend on their respective spin rates. These so-called insolation cycles affect temperature variations, climate, photosynthesis in plants, etc. Hence, experimental reproduction of these cycles is important for space analogue simulations. In this short note we describe a simple, low-cost method to simulate diurnal cycles in the laboratory using a type of commercial solar simulator commonly used for experimental investigation in planetary science

Evaluating an implementation strategy in cardiovascular prevention to improve prescribing of statins in Germany: an intention to treat analysis

BACKGROUND: The prescription of statins is an evidence-based treatment to reduce the risk of cardiovascular events in patients with elevated cardiovascular risk or with a cardiovascular disorder (CVD). In spite of this, many of these patients do not receive statins. METHODS: We evaluated the impact of a brief educational intervention in cardiovascular prevention in primary care physicians' prescribing behaviour regarding statins beyond their participation in a randomised controlled trial (RCT). For this, prescribing data of all patients >= 35 years who were counselled before and after the study period were analysed (each n > 75000). Outcome measure was prescription of Hydroxymethylglutaryl-CoA Reductase Inhibitors (statins) corresponding to patients' overall risk for CVD. Appropriateness of prescribing was examined according to different risk groups based on the Anatomical Therapeutic Chemical Classification System (ATC codes). RESULTS: There was no consistent association between group allocation and statin prescription controlling for risk status in each risk group before and after study participation. However, we found a change to more significant drug configurations predicting the prescription of statins in the intervention group, which can be regarded as a small intervention effect. CONCLUSION: Our results suggest that an active implementation of a brief evidence-based educational intervention does not lead to prescription modifications in everyday practice. Physician's prescribing behaviour is affected by an established health care system, which is not easy to change.Trial registration: ISRCTN71348772

Pottery technology among hunter-gatherers in the interhills area: the case study of Hangar Site (General Lamadrid county, province of Buenos Aires)

En las últimas décadas se desarrollaron estudios arqueológicos sistemáticos en la cuenca del arroyo Salado (partido de Lamadrid, área Interserrana, provincia de Buenos Aires). No obstante, los restos de alfarería son uno de los ítems materiales que aún no había sido estudiado en detalle debido a su escasez y alta fragmentación a nivel local. En este trabajo se presentan los primeros resultados del análisis macro y microscópico realizado al conjunto cerámico procedente del sitio Hangar, para el cual se cuenta con dos fechados que lo sitúan cronológicamente en el Holoceno tardío final. Mediante la evaluación de las elecciones técnicas se identificaron vasijas de morfologías simples y superficies alisadas. Composicionalmente se distinguen dos tipos de pastas que dan cuenta de la preparación y uso de diferentes materias primas para la producción de las piezas. Finalmente, se discute si esta tecnología fue manufacturada localmente o fue obtenida por interacciones con grupos vecinos.During recent decades systematic archaeological studies have been carried out in the Salado creek basin (Lamadrid county, Interhills area, Buenos Aires province). However, potsherds are one of the material items that have not yet been studied in detail due to their scarcity and high fragmentation at the local level. This work presents the first results of the macroscopic and microscopic analysis of the ceramic assemblage from the Hangar site, dated to the final Late Holocene. By evaluating the technical choices, vessels with simple morphologies and smooth surfaces were identified. Compositionally, two types of pastes were distinguished that account for the preparation and use of different raw materials for the production of the vessels. Finally, it is discussed whether this technology was produced locally or was obtained through interactions with neighboring groups.Sociedad Argentina de Antropologí

Correction: TNFR2 induced priming of the inflammasome leads to a RIPK1-dependent cell death in the absence of XIAP.

The original version of this article contained an error in the name of one of the co-authors (Erika Owsley). This has been corrected in the PDF and HTML versions

Is living in a household with children associated with SARS-CoV-2 seropositivity in adults? Results from the Swiss national seroprevalence study Corona Immunitas.

BACKGROUND We aimed to determine whether living in a household with children is associated with SARS-CoV-2 seropositivity in adults and investigated interacting factors that may influence this association. METHODS SARS-CoV-2 serology testing was performed in randomly selected individuals from the general population between end of October 2020 and February 2021 in 11 cantons in Switzerland. Data on sociodemographic and household characteristics, employment status, and health-related history was collected using questionnaires. Multivariable logistic regression was used to examine the association of living with children <18 years of age (number, age group) and SARS-CoV-2 seropositivity. Further, we assessed the influence of reported non-household contacts, employment status, and gender. RESULTS Of 2393 working age participants (18-64 years), 413 (17.2%) were seropositive. Our results suggest that living with children and SARS-CoV-2 seropositivity are likely to be associated (unadjusted odds ratio (OR) 1.22, 95% confidence interval [0.98-1.52], adjusted OR 1.25 [0.99-1.58]). A pattern of a positive association was also found for subgroups of children aged 0-11 years (OR 1.21 [0.90-1.60]) and 12-17 years (OR 1.14 [0.78-1.64]). Odds of seropositivity were higher with more children (OR 1.14 per additional child [1.02-1.27]). Men had higher risk of SARS-CoV-2 infection when living with children than women (interaction: OR 1.74 [1.10-2.76]). CONCLUSIONS In adults from the general population living with children seems associated with SARS-CoV-2 seropositivity. However, child-related infection risk is not the same for every subgroup and depends on factors like gender. Further factors determining child-related infection risk need to be identified and causal links investigated. TRIAL REGISTRATION https://www.isrctn.com/ISRCTN18181860

Is living in a household with children associated with SARS-CoV-2 seropositivity in adults? Results from the Swiss national seroprevalence study Corona Immunitas

BACKGROUND: We aimed to determine whether living in a household with children is associated with SARS-CoV-2 seropositivity in adults and investigated interacting factors that may influence this association. METHODS: SARS-CoV-2 serology testing was performed in randomly selected individuals from the general population between end of October 2020 and February 2021 in 11 cantons in Switzerland. Data on sociodemographic and household characteristics, employment status, and health-related history was collected using questionnaires. Multivariable logistic regression was used to examine the association of living with children <18 years of age (number, age group) and SARS-CoV-2 seropositivity. Further, we assessed the influence of reported non-household contacts, employment status, and gender. RESULTS: Of 2393 working age participants (18-64 years), 413 (17.2%) were seropositive. Our results suggest that living with children and SARS-CoV-2 seropositivity are likely to be associated (unadjusted odds ratio (OR) 1.22, 95% confidence interval [0.98-1.52], adjusted OR 1.25 [0.99-1.58]). A pattern of a positive association was also found for subgroups of children aged 0-11 years (OR 1.21 [0.90-1.60]) and 12-17 years (OR 1.14 [0.78-1.64]). Odds of seropositivity were higher with more children (OR 1.14 per additional child [1.02-1.27]). Men had higher risk of SARS-CoV-2 infection when living with children than women (interaction: OR 1.74 [1.10-2.76]). CONCLUSIONS: In adults from the general population living with children seems associated with SARS-CoV-2 seropositivity. However, child-related infection risk is not the same for every subgroup and depends on factors like gender. Further factors determining child-related infection risk need to be identified and causal links investigated

Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium.

Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P &lt; 0.0001), lower modularity (P &lt; 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions