The core of the cluster R136 in the Large Magellanic Cloud hosts the most massive stars known. The high mass-loss rates of these stars strongly impact their surroundings, as well as the evolution of the stars themselves. To quantify this impact accurate mass-loss rates are needed, however, uncertainty about the degree of inhomogeneity of the winds (‘wind clumping’), makes mass-loss measurements uncertain. We combine optical and ultraviolet HST/STIS spectroscopy of 56 stars in the core of R136 in order to put constraints on the wind structure, improving the accuracy of the mass-loss rate measurements. We find that the winds are highly clumped, and use our measured mass-loss rates to test theoretical predictions. Furthermore we find, for the first time, tentative trends in the wind-structure parameters as a function of mass-loss rate, suggesting that the winds of stars with higher mass-loss rates are less clumped than those with lower mass-loss rates.

Since the beginning of 2020, the coronavirus disease (COVID-19) pandemic has dramatically influenced almost every aspect of human life. Activities requiring human gatherings have either been postponed, canceled, or held completely virtually. To supplement lack of in-person contact, people have increasingly turned to virtual settings online, advantages of which include increased inclusivity and accessibility and a reduced carbon footprint. However, emerging online technologies cannot fully replace in-person scientific events. In-person meetings are not susceptible to poor Internet connectivity problems, and they provide novel opportunities for socialization, creating new collaborations and sharing ideas. To continue such activities, a hybrid model for scientific events could be a solution offering both in-person and virtual components. While participants can freely choose the mode of their participation, virtual meetings would most benefit those who cannot attend in-person due to the limitations. In-person portions of meetings should be organized with full consideration of prevention and safety strategies, including risk assessment and mitigation, venue and environmental sanitation, participant protection and disease prevention, and promoting the hybrid model. This new way of interaction between scholars can be considered as a part of a resilience system, which was neglected previously and should become a part of routine practice in the scientific community.

Northern Australia is a region where limited information exists on environments at the last glacial maximum (LGM). Girraween Lagoon is located on the central northern coast of Australia and is a site representative of regional tropical savanna woodlands. Girraween Lagoon remained a perennial waterbody throughout the LGM, and as a result retains a complete proxy record of last-glacial climate, vegetation and fire. This study combines independent palynological and geochemical analyses to demonstrate a dramatic reduction in both tree cover and woody richness, and an expansion of grassland, relative to current vegetation at the site. The process of tree decline was primarily controlled by the cool-dry glacial climate and CO2 effects, though more localised site characteristics restricted wetland-associated vegetation. Fire processes played less of a role in determining vegetation than during the Holocene and modern day, with reduced fire activity consistent with significantly lower biomass available to burn. Girraween Lagoon's unique and detailed palaeoecological record provides the opportunity to explore and assess modelling studies of vegetation distribution during the LGM, particularly where a number of different global vegetation and/or climate simulations are inconsistent for northern Australia, and at a range of resolutions.

The phenomenon of buying-shopping disorder (BSD) was described over 100 years ago. Definitions of BSD refer to extreme preoccupation with shopping and buying, to impulses to purchase that are experienced as irresistible, and to recurrent maladaptive buying excesses that lead to distress and impairments. Efforts to stop BSD episodes are unsuccessful, despite the awareness of repeated break-downs in self-regulation, experiences of post-purchase guilt and regret, comorbid psychiatric disorders, reduced quality of life, familial discord, work impairment, financial problems, and other negative consequences. A recent meta-analysis indicated an estimated point prevalence of BSD of 5%. In this narrative review, the authors offer a perspective to consider BSD as a mental health condition and to classify this disorder as a behavioral addiction, based on both research data and on long-standing clinical experience.

Even though one of the public health's top achievements of the 20th century involves tobacco cessation, a disproportionate burden of tobacco-related comorbidity still affects those with mental illness (Centers for Disease Control and Prevention, 2017; Cook et al., 2014). There is evidence suggesting that psychiatric disorders are associated with an increased prevalence in cigarette smoking (Tsoi, Porwa, & Webster, 2013). One explanation for this is the potentiating effect of nicotine on dopamine receptors (Mao, Gallagher, & McGehee, 2011). Other explanations include poverty, educational advancement and industry bias in tobacco marketing (MMWR Vital Signs: Current Cigarette, 2016; CDC Morbidity and Mortality, 2013). We know that adults with mental illness smoke at rates twice that of the general population, and are nicotine-dependent at rates up to three times higher than the general population (Cook et al., 2014; Grant, Hasin, Chou, Stinson, & Dawson, 2004). Adults with mental illness comprise about 19% of the population, but smoke approximately one-third of all the cigarettes smoked (MMWR Vital Signs: Current Cigarette, 2016). In the United States, the national tobacco use prevalence is estimated at 19%; however, prevalence among those with bipolar disorder is 51%–70% and 36%–80% among those with major depressive disorder (Grant et al., 2004; King, Dube, & Tynan, 2012; Lasser et al., 2000). Despite these high rates, recent studies suggest that smokers with mental illness are highly motivated to quit (Cook et al., 2014). However, it remains rare for mental and behavioural health professionals to offer tobacco cessation pharmacotherapy and counselling to clients with psychiatric disorders.

The lower Mississippian Ballagan Formation of northern Britain is one of only two successions worldwide to yield the earliest known tetrapods with terrestrial capability following the end-Devonian mass extinction event. Studies of the sedimentary environments and habitats in which these beasts lived have been an integral part of a major research project into how, why and under what circumstances this profound step in the evolution of life on Earth occurred. Here, a new palaeogeographic map is constructed from outcrop data integrated with new and archived borehole material. The map shows the extent of a very low-relief coastal wetland developed along the tropical southern continental margin of Laurussia. Coastal floodplains in the Midland Valley and Tweed basins were separated from the marginal marine seaway of the Northumberland–Solway Basin to the south by an archipelago of more elevated areas. A complex mosaic of sedimentary environments was juxtaposed, and included fresh and brackish to saline and hypersaline lakes, a diverse suite of floodplain palaeosols and a persistent fluvial system in the east of the region. The strongly seasonal climate led to the formation of evaporite deposits alternating with flooding events, both meteoric and marine. Storm surges drove marine floods from the SW into both the western Midland Valley and Northumberland–Solway Basin; marine water also flooded into the Tweed Basin and Tayside in the east. The Ballagan Formation is a rare example in the geological record of a tropical, seasonal coastal wetland that contains abundant, small-scale evaporite deposits. The diverse sedimentary environments and palaeosol types indicate a network of different terrestrial and aquatic habitats in which the tetrapods lived.

The majority of children with Down syndrome (DS) develop Alzheimer's disease (AD) at an early age. Although long-chain n-3 fatty acids (FA) are protective of neurodegeneration, little is known about the FA status in DS. In the present study, we aimed to investigate whether children with DS presented altered plasma and erythrocyte membrane phospholipids (PL) FA composition, when compared with their non-affected siblings. Venous blood samples were analysed for plasma and erythrocyte membrane FA composition by TLC followed by GC techniques. Lipid molecular species were determined by electrospray ionisation/tandem MS (ESI-MS/MS). FA analysis measured by standard GC showed an increased concentration of MUFA and a decreased concentration of plasmalogens in major PL fractions, but there were no differences in the concentrations of arachidonic acid or DHA. However, as identified by ESI-MS/MS, children with DS had increased levels of the following erythrocyte PL molecular species: 16 : 0–16 : 0, 16 : 0–18 : 1 and 16 : 0–18 : 2n-6, with reduced levels of 16 : 0–20 : 4n-6 species. Children with DS presented significantly higher levels of MUFA in both plasma and erythrocyte membrane, as well as higher levels of saturated and monounsaturated molecular species. Of interest was the almost double proportion of 16 : 0–18 : 2n-6 and nearly half the proportion of 16 : 0–20 : 4n-6 of choline phosphoacylglycerol species in children with DS compared with their non-affected siblings. These significant differences were only revealed by ESI-MS/MS and were not observed in the GC analysis. Further investigations are needed to explore molecular mechanisms and to test the association between the pathophysiology of DS and the risk of AD.

There has been a recent resurgence in interest in developing ohmic switches to complement transistors in order to address challenges associated with electrical current leakage. A critical limitation in ohmic switches remains the reliability of their electrical contacts. These contacts are prone to hydrocarbon induced contamination which progressively inhibits signal transmission, eventually leading to device failure. We report on progress made towards controlling the contamination phenomenon. We discuss how contact materials and operating environment affect device performance, showing that RuO2 coated microswitch contacts operating in the presence of O2 experience very limited contaminant accumulation even in hydrocarbon-rich environments. We then demonstrate that devices which have experienced contamination can recover their original performance by being operated in clean N2:O2 environment. Finally, we suggest that this resistance recovery is associated with the chemical transformation of the contaminant as opposed to its removal and that the transformed contaminant may shield the Pt coating from oxidation.

Spectra from 1 to 2·5 μm, at 230–430 spectral resolution, are presented of the fluorescent molecular hydrogen line emission from two locations in the reflection nebula NGC 2023. Over 100 H2 lines can be identified in the spectra, although blending and poor atmospheric transmission mean that reliable level column densities can only be obtained from 35 lines. This latter group includes lines from v = 1–8 and v = 10, spanning an energy range from 6000 to 45,000 K above the ground state. These data may be used to constrain models of photodissociation regions and of fluorescent excitation for molecular hydrogen.

The development of lower-glycaemic index (GI) foods requires simple, palatable and healthy strategies. The objective of the present study was to determine the most effective dose of a novel viscous fibre supplement (PGX®) to be added to starchy foods to reduce their GI. Healthy subjects (n 10) consumed glucose sugar (50 g in water × 3) and six starchy foods with a range of GI values (52–72) along with 0 (inert fibre), 2·5 or 5 g granular PGX® dissolved in 250 ml water. GI testing according to ISO Standard 26 642-2010 was used to determine the reduction in GI. PGX® significantly reduced the GI of all six foods (P < 0·001), with an average reduction of 19 % for the 2·5 g dose and 30 % for the 5 g dose, equivalent to a reducing the GI by 7 and 15 units, respectively. Consuming small quantities of the novel functional fibre PGX®, mixed with water at the start of a meal, is an effective strategy to reduce the GI of common foods.

Intramyocellular lipid (IMCL) and plasma NEFA are important skeletal muscle fuel sources. By raising blood insulin concentrations, carbohydrate ingestion inhibits lypolysis and reduces circulating NEFA. We hypothesised that differences in the postprandial glycaemic and insulin response to carbohydrates (i.e. glycaemic index; GI) could alter NEFA availability and IMCL use during subsequent exercise. Endurance-trained individuals (n 7) cycled for 90 min at 70 % V˙O2peak and then consumed either high GI (HGI) or low GI (LGI) meals over the following 12 h. The following day after an overnight fast, the 90 min cycle was repeated. IMCL content of the vastus lateralis was quantified using magnetic resonance spectroscopy before and after exercise. Blood samples were collected at 15 min intervals throughout exercise and analysed for NEFA, glycerol, glucose, insulin, and lactate. Substrate oxidation was calculated from expired air samples. The 90 min cycle resulted in >2-fold greater reduction in IMCL in the HGI trial (3·5 (sem 1·0) mm/kg wet weight) than the LGI trial (1·6 (sem 0·3) mm/kg wet weight, P < 0·05). During exercise, NEFA availability was reduced in the HGI trial compared to the LGI trial (area under curve 2·36 (sem 0·14) mEq/l per h v. 3·14 (sem 0·28) mEq/l per h, P < 0·05 respectively). No other differences were significant. The findings suggest that HGI carbohydrates reduce NEFA availability during exercise and increase reliance on IMCL as a substrate source during moderate intensity exercise.

Organic light-emitting diodes (OLED) offer the potential to replace conventional light sources such as incandescent bulbs and fluorescent tubes. The question which thin-film technology is most favorable to produce OLED on an industrial scale is still unanswered. The most established technology for the deposition of small-molecule organic layers is vacuum thermal evaporation. A comparably novel technology is organic vapor phase deposition (OVPD), which offers some unique features in terms of adjustable process parameters such as deposition chamber pressure (P) and substrate temperature (TS). The impact of these parameters on the morphology of organic single layers as well as on the performance of OLED is mostly unknown. In this work, phosphorescent red OLED were produced with different TS and a strong influence on the device efficiency was found. Atomic force microscopy measurements were conducted to investigate the morphology of the hole injection and hole transport layers of the devices deposited at different TS. In addition to this, the influence of TS and P on the performance of fluorescent blue OLED and the morphology of organic single layers was tested. By varying TS and P for the emission layer only, current efficiencies in the range from 4.3 to 6.8 cd/A were found despite the fact that all devices had the same structure. Atomic force microscopy measurements conducted on organic single layers which were deposited at the same process conditions showed rms values ranging from 1.4 to 57 nm.

In this paper we report on the development of micromachined filters for operation at terahertz frequencies. SU8, a negative photodefinable epoxy, is used to define arrays of high aspect ratio rods which are subsequently sputter coated in gold to form the filter. We fabricate and test a filter with a fixed period but variable diameter along the length of the array. By moving the array in the terahertz beam we demonstrate the ability to mechanically tune specific filter characteristics from a single device.