Pulsed laser deposition growth of Fe3O4 on III–V semiconductors for spin injection

We report on the growth of thin layers of Fe3O4 on GaAs and InAs by pulsed laser deposition. It is found that Fe3O4 grows epitaxially on InAs at a temperature of 350 °C. X-ray photoelecton spectroscopy (XPS) studies of the interface show little if any interface reaction resulting in a clean epitaxial interface. In contrast, Fe3O4 grows in columnar fashion on GaAs, oriented with respect to the growth direction but with random orientation in the plane of the substrate. In this case XPS analysis showed much more evidence of interface reactions, which may contribute to the random-in-plane growth

The most massive galaxies in clusters are already fully grown at z∼0.5z \sim 0.5

By constructing scaling relations for galaxies in the massive cluster MACSJ0717.5 at $z=0.545$ and comparing with those of Coma, we model the luminosity evolution of the stellar populations and the structural evolution of the galaxies. We calculate magnitudes, surface brightnesses and effective radii using HST/ACS images and velocity dispersions using Gemini/GMOS spectra, and present a catalogue of our measurements for 17 galaxies. We also generate photometric catalogues for $\sim 3000$ galaxies from the HST imaging. With these, we construct the colour-magnitude relation, the fundamental plane, the mass-to-light versus mass relation, the mass-size relation and the mass-velocity dispersion relation for both clusters. We present a new, coherent way of modelling these scaling relations simultaneously using a simple physical model in order to infer the evolution in luminosity, size and velocity dispersion as a function of redshift, and show that the data can be fully accounted for with this model. We find that (a) the evolution in size and velocity dispersion undergone by these galaxies between $z \sim 0.5$ and $z \sim 0$ is mild, with $R_e(z) \sim (1+z)^{-0.40\pm0.32}$ and $\sigma(z) \sim (1+z)^{0.09 \pm 0.27}$, and (b) the stellar populations are old, $\sim 10$ Gyr, with a $\sim 3$ Gyr dispersion in age, and are consistent with evolving purely passively since $z \sim 0.5$ with $\Delta \log M/L_B = -0.55_{-0.07}^{+0.15} z$. The implication is that these galaxies formed their stars early and subsequently grew dissipationlessly so as to have their mass already in place by $z \sim 0.5$, and suggests a dominant role for dry mergers, which may have accelerated the growth in these high-density cluster environments.Comment: 20 pages; accepted for publication in MNRA

Hairy St. John’s-wort (Hypericum hirsutum L.) in the Toronto Area, New to North America

Hairy St. John’s-wort (Hypericum hirsutum L.) is newly reported for Canada and North America based on two collections from the Toronto, Ontario, area. This perennial Eurasian herb has a large natural range from western Europe to western China. It grows in moist successional, edge, and meadow habitats. It should be looked for in such habitats elsewhere in eastern North America

Association of the Covid-19 lockdown with smoking, drinking, and attempts to quit in England: an analysis of 2019-2020 data

Aim: To examine changes in smoking, drinking and quitting/reduction behaviour following the COVID‐19 lockdown in England. Design/setting: Monthly cross‐sectional surveys representative of the adult population in England, aggregated before (April 2019–February 2020) versus after (April 2020) lockdown. Participants: A total of 20 558 adults (≥ 16 years). Measurements: The independent variable was the timing of the COVID‐19 lockdown (before versus after March 2020). Dependent variables were: prevalence of smoking and high‐risk drinking, past‐year cessation and quit attempts (among past‐year smokers), past‐year attempts to reduce alcohol consumption (among high‐risk drinkers) and use of evidence‐based (e.g. prescription medication/face‐to‐face behavioural support) and remote support [telephone support/websites/applications (apps)] for smoking cessation and alcohol reduction (among smokers/high‐risk drinkers who made a quit/reduction attempt). Covariates included age, sex, social grade, region and level of nicotine and alcohol dependence (as relevant). Findings: The COVID‐19 lockdown was not associated with a significant change in smoking prevalence [17.0% (after) versus 15.9% (before), odds ratio (OR) = 1.09, 95% CI = 0.95–1.24], but was associated with increases in quit attempts [39.6 versus 29.1%, adjusted odds ratio (ORadj) = 1.56, 95% CI = 1.23–1.98], quit success (21.3 versus 13.9%, ORadj = 2.01, 95% CI = 1.22–3.33) and cessation (8.8 versus 4.1%, ORadj = 2.63, 95% CI = 1.69–4.09) among past‐year smokers. Among smokers who tried to quit, there was no significant change in use of evidence‐based support (50.0 versus 51.5%, ORadj = 1.10, 95% CI = 0.72–1.68) but use of remote support increased (10.9 versus 2.7%, ORadj = 3.59, 95% CI = 1.56–8.23). Lockdown was associated with increases in high‐risk drinking (38.3 versus 25.1%, OR = 1.85, CI = 1.67–2.06), but also alcohol reduction attempts by high‐risk drinkers (28.5 versus 15.3%, ORadj = 2.16, 95% CI = 1.77–2.64). Among high‐risk drinkers who made a reduction attempt, use of evidence‐based support decreased (1.2 versus 4.0%, ORadj = 0.23, 95% CI = 0.05–0.97) and there was no significant change in use of remote support (6.9 versus 6.1%, ORadj = 1.32, 95% CI = 0.64–2.75). Conclusions: Following the March 2020 COVID‐19 lockdown, smokers and high‐risk drinkers in England were more likely than before lockdown to report trying to quit smoking or reduce alcohol consumption and rates of smoking cessation and use of remote cessation support were higher. However, high‐risk drinking prevalence increased post‐lockdown and use of evidence‐based support for alcohol reduction by high‐risk drinkers decreased with no compensatory increase in use of remote support

Anomalous Rotational Relaxation: A Fractional Fokker-Planck Equation Approach

In this study we obtained analytically relaxation function in terms of rotational correlation functions based on Brownian motion for complex disordered systems in a stochastic framework. We found out that rotational relaxation function has a fractional form for complex disordered systems, which indicates relaxation has non-exponential character obeys to Kohlrausch-William-Watts law, following the Mittag-Leffler decay.Comment: Revtex4, 9 pages. Paper was revised. References adde

Mapping the landscape of climate engineering.

In the absence of a governance framework for climate engineering technologies such as solar radiation management (SRM), the practices of scientific research and intellectual property acquisition can de facto shape the development of the field. It is therefore important to make visible emerging patterns of research and patenting, which we suggest can effectively be done using bibliometric methods. We explore the challenges in defining the boundary of climate engineering, and set out the research strategy taken in this study. A dataset of 825 scientific publications on climate engineering between 1971 and 2013 was identified, including 193 on SRM; these are analysed in terms of trends, institutions, authors and funders. For our patent dataset, we identified 143 first filings directly or indirectly related to climate engineering technologies-of which 28 were related to SRM technologies-linked to 910 family members. We analyse the main patterns discerned in patent trends, applicants and inventors. We compare our own findings with those of an earlier bibliometric study of climate engineering, and show how our method is consistent with the need for transparency and repeatability, and the need to adjust the method as the field develops. We conclude that bibliometric monitoring techniques can play an important role in the anticipatory governance of climate engineering

Factors associated with drinking behaviour during COVID-19 social distancing and lockdown among adults in the UK

Aim: To assess what factors were associated with reported changes to usual alcohol drinking behaviour during the start of lockdown in the UK. / Design: Online cross-sectional survey from 21st March to 4th April 2020. / Setting: UK. / Participants: 30,375 adults aged ≥ 18y. / Measurements: Changes in drinking over the past week, sociodemographic characteristics, diagnosed or suspected COVID-19, adherence to COVID-19 protective behaviours, stress about COVID-19, finances or boredom, recent drop in household income, key worker status, and health conditions. / Findings: Of 22,113 drinkers (65.7% of analytic sample), 48.1% (95% CI=47.0-49.1%) reported drinking about the same as usual, 25.7% (24.8-26.6%) reported drinking less than usual, and 26.2% (25.4-27.1%) reported drinking more than usual over the past week. Drinking less than usual was independently associated with being younger (OR=0.88 [95% CI=0.83-0.93]), male (OR=0.76 [0.68-0.84]), of an ethnic minority (OR=0.76 [0.61-0.97]), low annual household income (OR=0.74 [0.66-0.83]), having diagnosed or suspected COVID-19 (OR=2.04 [1.72-2.41]), adhering to COVID-19 protective behaviours (OR=1.58 [1.08-2.32]), being significantly stressed about becoming seriously ill from COVID-19 (OR=1.26 [1.08-1.48]) and not being a key worker (OR=0.87 [0.76-0.99]). Drinking more than usual was independently associated with being younger (OR=0.73 [0.69-0.78]), female (OR=1.36 [1.22-1.51]), post-16 qualifications (OR=1.21 [1.04-1.40]), high annual household income (OR=1.43 [1.27-1.61]), being significantly stressed about catching (OR=1.22 [1.03-1.45]) or becoming seriously ill from COVID-19 (OR=1.28 [1.10-1.48]), being significantly stressed about finances (OR=1.43 [1.24-1.66]), and having a diagnosed anxiety disorder (OR=1.24 [1.05-1.46]). / Conclusions: In a representative sample of adults in the UK, about half of drinkers reported drinking the same amount of alcohol as usual during the start of the COVID-19 related lockdown, with a quarter drinking more and a quarter drinking less than usual. Drinking more than usual was associated with being younger, female, high socioeconomic position, having an anxiety disorder, and being stressed about finances or COVID-19. These groups may benefit targeted alcohol reduction support if there are further periods of lockdown. / Registration: The analysis plan was pre-registered on Open Science Framework (https://osf.io/pnrhq/)

Grazing Management of Tagasaste (Chamaecytisus Proliferus) for Sheep and Cattle Production in Southern Australia

Direct grazing of hedgerows of tagasaste (Chamaecytisus proliferus) by sheep or cattle appear to be very robust systems. Tagasaste persists under a continuous grazing regime with cattle such that plant regrowth maintained between 5 and 10 cm in length produces in excess of 215 kg of animal liveweight/ha/year. This level of production is also sustained within a rotational grazing regime. Under both grazing systems cattle production within a year is highly seasonal, with liveweight gains from young cattle peaking at 1.0-1.5 kg/head/day in winter and spring, but dropping to maintenance only by late summer-autumn. Sheep, like cattle, can be grazed on tagasaste at any time of the year, however their different grazing habits demand sheep be used in an intensive, short-term grazing system for approximately 30 days at a time on any one stand of tagasaste

The Effect on Intake Palatability and Digestibility of Phenolic Compounds in Tagasaste (Chamaecytisus proliferus)

The major secondary metabolites currently identified in tagasaste (Chamaecytisus proliferus) belong to the phenolic group of compounds. The principal phenolic compounds are the flavones, apigenin and luteolin, but low concentrations of condensed tannins, the isoflavonoid daidzein and the alkaloid sparteine have also been detected in some samples. No flavonols have been detected. There is a strong relationship between the concentration of phenolic compounds in tagasaste and its palatability. Furthermore, digestibility of tagasaste is relatively high throughout the year, thereby implicating intake as the major factor influencing the seasonality of liveweight performance of livestock grazing tagasaste. Despite confirmation of the presence of a number of secondary metabolites in tagasaste, there remains an urgent need to screen tagasaste for all possible compounds of this kind in order to fully understand the seasonal constraints to livestock production associated with this important fodder shrub

Using the fractional interaction law to model the impact dynamics in arbitrary form of multiparticle collisions

Using the molecular dynamics method, we examine a discrete deterministic model for the motion of spherical particles in three-dimensional space. The model takes into account multiparticle collisions in arbitrary forms. Using fractional calculus we proposed an expression for the repulsive force, which is the so called fractional interaction law. We then illustrate and discuss how to control (correlate) the energy dissipation and the collisional time for an individual article within multiparticle collisions. In the multiparticle collisions we included the friction mechanism needed for the transition from coupled torsion-sliding friction through rolling friction to static friction. Analysing simple simulations we found that in the strong repulsive state binary collisions dominate. However, within multiparticle collisions weak repulsion is observed to be much stronger. The presented numerical results can be used to realistically model the impact dynamics of an individual particle in a group of colliding particles.Comment: 17 pages, 8 figures, 1 table; In review process of Physical Review