Silicon isotopes highlight the role of glaciated fjords in modifying coastal waters

Glaciers and ice sheets are experiencing rapid warming under current climatic change and there is increasing evidence that glacial meltwaters provide key dissolved and dissolvable amorphous nutrients to downstream ecosystems. However, large debate exists around the fate of these nutrients within complex and heterogenous fjord environments, where biogeochemical cycling is still often poorly understood. We combine silicon (Si) concentration data with isotopic compositions to better understand silicon cycling and export in two contrasting fjordic environments in south-west Greenland. We show that both fjords have isotopically light dissolved silicon (DSi) within surface waters, despite an apparently rapid biological drawdown of DSi with increasing salinity. We hypothesise that such observations cannot be explained by simple water mass mixing processes, and postulate that an isotopically light source of Si, most likely glacially-derived amorphous silica (ASi), is responsible for further modifying these coastal waters within the fjords and beyond. Fjord to coastal exchange is likely a relatively slow process (several months), and thus is less impacted by short-term (< seasonal) changes of glacial meltwater input into the fjord, which has implications when considering the role of glacial meltwaters on nutrient export beyond the shelf break. We highlight the need for isotopic studies combined with dissolved and particulate nutrient concentration analysis to provide a more detailed analysis into the biogeochemical cycles within these highly dynamic fjord environments

Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Effect of textured insoles on balance and gait in people with multiple sclerosis: an exploratory trial

Objectives: To investigate the immediate effects of textured insoles on balance and gait in people with multiple sclerosis (MS), and to explore any effects after 2 weeks of wear. Study design: Within-session repeated-measures design with an exploratory follow-up period. Setting: Hospital gait laboratory. Participants: Forty-six individuals with MS (34 females, 12 males), with a mean (SD) age of 49 (7) years, who could walk 100. m unassisted or using one stick/crutch. Intervention: Participants were tested wearing three types of insoles in a random order: control (smooth), Texture 1 (Algeos) or Texture 2 (Crocs™). Participants were allocated at random to wear one type of textured insoles for 2 weeks, after which they were retested. Main outcome measures: Standing balance (centre of pressure excursions and velocity) was measured with eyes open and eyes closed on a Kistler force platform. Spatio-temporal parameters of gait were measured using a GAITRite system. Results: The textured insoles had no significant immediate effects on balance or gait, apart from an increase in anteroposterior sway range with eyes open for Texture 2 insoles [mean difference 4.5 (95% confidence interval 0.6 to 8.4). mm]. After 2 weeks, balance was not significantly different, but both types of textured insoles showed significant effects on spatio-temporal parameters of gait, with mean stride length increases of 3.5. cm (Texture 1) and 5.3. cm (Texture 2) when wearing the insoles. Conclusions: After 2 weeks of wear, there were improvements in spatio-temporal parameters of gait. However, it is unclear whether this was a placebo effect or a learning effect

Gendered Performances in a Male-Dominated Subculture: 'Girl Racers', Car Modification and the Quest for Masculinity

This paper discusses female participation in the male-dominated 'boy racer' culture. Little is known about girls who join male-dominated subcultures while studies of car cultures have tended to describe girls as peripheral participants and emphasise the link between the car and masculinity. Hence this paper provides an analysis of 'girl racers'; those drivers who are active participants in the 'racer' culture through their positioning in the 'driver's seat'. Gender is understood as 'performative' and Connell's notions of 'hegemonic masculinity' and 'emphasized femininity' frame the analysis. For the 'girl racers', 'doing gender' involved negotiating a complex set of norms while reconciling the competing discourses of the masculine 'racer' scene and femininity. In order to be viewed as authentic participants, females were required to act like 'one of the boys' through their style of dress, driving, language and attitudes. They internalised the gender norms of the culture rather than resisting them explicitly, for fear of being excluded from the group. However, the feminine ways in which they modified their cars allowed them to retain an element of femininity within the world of 'boy racers'. Thus, 'girl racers' resourcefully negotiated their way through the culture by employing a combination of complex strategies involving compliance, resistance and cooperation with the masculine values of the group. Findings are presented from participant observation, semi-structured and ethnographic interviews with members of the 'racer' culture in Aberdeen, Scotland, and semi-structured interviews with members of 'outside' groups