Using the C-O stretch to unravel the nature of hydrogen bonding in low-temperature solid methanol-water condensates

Transmission infrared spectroscopy has been used in a systematic laboratory study to investigate hydrogen bonding in binary mixtures of CH3OH and H2O, vapour deposited at 30 K, as a function of CH3OH/H2O mixing ratio, R. Strong intermolecular interactions are evident between CH3OH and H2O with infrared band profiles of the binary ices differing from that of the pure components and changing significantly with R. Consistent evidence from the O–H and C–H band profiles and detailed analysis of the C–O stretch band reveal two different hydrogen bonding structural regimes below and above R=0.6–0.7. The vapour deposited solid mixtures were found to exhibit behaviour similar to that of liquids with evidence of inhomogeneity and higher coordination number of hydrogen bonds that are concentration dependent. The C–O stretch band was found to consist of three components around 1039 cm-1 (’blue’), 1027 cm-1(’middle’) and 1011 cm-1 (’red’). The ’blue’ and ’middle’ components corresponding to environments with CH3OH dominating as a proton donor (PD) and proton acceptor (PA) respectively reveal preferential bonding of CH3OH as a PA and H2O as a PD in the mixtures. The ’red’ component is only present in the presence of H2O and has been assigned to the involvement of both lone pairs of electrons on the oxygen atom of CH3OH as a PA to two PD H2O atoms. Cooperative effects are evident with concurrent blue-shifts in the C–H stretching modes of CH3OH below R=0.6 indicating CH3 group participation in hydrogen bonding

Understanding Coronal Heating with Emission Measure Distributions

It is widely believed that the cross-field spatial scale of coronal heating is small, so that the fundamental plasma structures (loop strands) are spatially unresolved. We therefore must appeal to diagnostic techniques that are not strongly affected by spatial averaging. One valuable observable is the emission measure distribution, EM(T), which indicates how much material is present at each temperature. Using data from the Extreme-ultraviolet Imaging Spectrograph on the Hinode mission, we have determined emission measure distributions in the cores of two active regions. The distributions have power law slopes of approximately 2.4 coolward of the peak. We compare these slopes, as well as the amount of emission measure at very high temperature, with the predictions of a series of models. The models assume impulsive heating (nanoflares) in unresolved strands and take full account of non equilibrium ionization. A variety of nanoflare properties and initial conditions are considered. We also comment on the selection of spectral lines for upcoming missions like Solar Orbiter

Childhood abuse and the content of delusions

Original article can be found at: http://www.sciencedirect.com/science/journal/01452134 Copyright Elsevier Ltd.We aimed to investigate possible associations between histories of childhood abuse and the content of delusions for individuals with psychotic disorders. 39 participants with a psychotic disorder including one or more delusional beliefs successfully completed structured interviews about childhood trauma, delusional beliefs and associated anomalous perceptual experiences including hallucinations. The presence of hallucinations was predicted by greater physical abuse. Greater abuse in general was associated with delusions involving ‘special abilities’ (grandiosity) and, at trend levels, with those involving ‘defective self’. Though preliminary, these results suggest that further investigation is warranted. The presence and nature of abuse may be relevant to delusional presentations and should form an essential part of clinical assessment of psychotic disorder.Peer reviewe

An adaptive two-arm clinical trial using early endpoints to inform decision making : design for a study of sub-acromial spacers for repair of rotator cuff tendon tears

Background There is widespread concern across the clinical and research communities that clinical trials, powered for patient-reported outcomes, testing new surgical procedures are often expensive and time-consuming, particularly when the new intervention is shown to be no better than the standard. Conventional (non-adaptive) randomised controlled trials (RCTs) are perceived as being particularly inefficient in this setting. Therefore, we have developed an adaptive group sequential design that allows early endpoints to inform decision making and show, through simulations and a worked example, that these designs are feasible and often preferable to conventional non-adaptive designs. The methodology is motivated by an ongoing clinical trial investigating a saline-filled balloon, inserted above the main joint of the shoulder at the end of arthroscopic debridement, for treatment of tears of rotor cuff tendons. This research question and setting is typical of many studies undertaken to assess new surgical procedures. Methods Test statistics are presented based on the setting of two early outcomes, and methods for estimation of sequential stopping boundaries are described. A framework for the implementation of simulations to evaluate design characteristics is also described. Results Simulations show that designs with one, two and three early looks are feasible and, with appropriately chosen futility stopping boundaries, have appealing design characteristics. A number of possible design options are described that have good power and a high probability of stopping for futility if there is no evidence of a treatment effect at early looks. A worked example, with code in R, provides a practical demonstration of how the design might work in a real study. Conclusions In summary, we show that adaptive designs are feasible and could work in practice. We describe the operating characteristics of the designs and provide guidelines for appropriate values for the stopping boundaries for the START:REACTS (Sub-acromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery) study

Supporting Early-Career Academics in the UK Computer Science Community

The early career of a computer science academic in the United Kingdom (UK) — as with most other disciplines — is challenging in terms of balancing research aspirations, learning and teaching responsibilities, wider academic service commitments, as well as their own professional development. In terms of learning and teaching development, this commonly involves working towards Fellow- ship of the Higher Education Academy (now known as Advance HE), either by direct application or via successful completion of an accredited institutional taught postgraduate course. Typically, if a course is required (often as part of their academic probation), the focus will be general higher education learning and teaching pedagogy rather than specifically focused on computer science and cognate areas. The formal institutional course requirements are normally supplemented by mentoring from within their department from experienced academic colleagues. Thus, the quality of development for an early-career academic will be enhanced in part by the strength of the community of practice operating within the department and the communities of practice that exist at a national and international level, often through professional bodies, learned societies and sub-disciplinary groupings. This paper presents the work-in-progress to address some of these structural, cultural and community challenges at both the institutional and national level in the UK, based on empirical themes collected from a workshop held at UKICER’20. We identify a number of specific actions and recommendations to supplement the current formal institutional requirements with enhanced national-level academic practice support and professional development, alongside local and regional professional mentoring

Toward an assessment of the global inventory of present-day mercury releases to freshwater environments

Aquatic ecosystems are an essential component of the biogeochemical cycle of mercury (Hg), as inorganic Hg can be converted to toxic methylmercury (MeHg) in these environments and reemissions of elemental Hg rival anthropogenic Hg releases on a global scale. Quantification of effluent Hg releases to aquatic systems globally has focused on discharges to the global oceans, rather than contributions to freshwater systems that affect local exposures and risks associated with MeHg. Here we produce a first-estimate of sector-specific, spatially resolved global aquatic Hg discharges to freshwater systems. We compare our release estimates to atmospheric sources that have been quantified elsewhere. By analyzing available quantitative and qualitative information, we estimate that present-day global Hg releases to freshwater environments (rivers and lakes) associated with anthropogenic activities have a lower bound of ~1000 Mg· a−1. Artisanal and small-scale gold mining (ASGM) represents the single largest source, followed by disposal of mercury-containing products and domestic waste water, metal production, and releases from industrial installations such as chlor-alkali plants and oil refineries. In addition to these direct anthropogenic inputs, diffuse inputs from land management activities and remobilization of Hg previously accumulated in terrestrial ecosystems are likely comparable in magnitude. Aquatic discharges of Hg are greatly understudied and further constraining associated data gaps is crucial for reducing the uncertainties in the global biogeochemical Hg budget

Trainee teachers' use of blogs as private reflections for professional development

A collaborative research project between Sheffield Hallam University and Nottingham Trent University in the UK investigated the use of blogs with trainee teachers as an alternative to reflective paper-based diaries. An action research case study, involving focus groups of post-graduate (secondary) trainee teachers (one group from each University) was undertaken to determine attitudes and perceptions of blogging as an appropriate tool to support reflective professional development. The findings indicate that the use of blogs by the trainee teachers had a positive impact overall, and provide concrete evidence of their development as emerging professional teachers. Unlike traditional paper-based systems, blogs provided ongoing opportunities for the tutor to assist the trainees in their development as reflective practitioners. This paper seeks to share the findings of this research which the authors believe could be applicable to other areas of Higher Education.</p