Epitaxial growth of few-layer MoS2(0001) on FeS2{100}.

Physical vapour deposition of Mo on an FeS2{100} surface was performed at 170 K. Near-epitaxial growth of MoS2(0001) overlayers of the order of 1 nm thickness was observed when the Mo-covered substrate was subsequently heated to 600 K.The authors thank the EPSRC (grant ref. EP/E039782/1) for funding.This is the final published version. It first appeared at http://pubs.rsc.org/en/Content/ArticleLanding/2015/CC/c4cc06628f#!divAbstract

A mechanistic modelling approach for the determination of the mechanisms of inhibition by cyclosporine on the uptake and metabolism of atorvastatin in rat hepatocytes using a high throughput uptake method

(1) Determine the inhibition mechanism through which cyclosporine inhibits the uptake and metabolism of atorvastatin in fresh rat hepatocytes using mechanistic models applied to data generated using a high throughput oil spin method. (2) Atorvastatin was incubated in fresh rat hepatocytes (0.05–150 nmol/ml) with or without 20 min pre-incubation with 10 nmol/ml cyclosporine and sampled over 0.25–60 min using a high throughput oil spin method. Micro-rate constant and macro-rate constant mechanistic models were ranked based on goodness of fit values. (3) The best fitting model to the data was a micro-rate constant mechanistic model including non-competitive inhibition of uptake and competitive inhibition of metabolism by cyclosporine (Model 2). The association rate constant for atorvastatin was 150-fold greater than the dissociation rate constant and 10-fold greater than the translocation into the cell. The association and dissociation rate constants for cyclosporine were 7-fold smaller and 10-fold greater, respectively, than atorvastatin. The simulated atorvastatin-transporter-cyclosporine complex derived using the micro-rate constant parameter estimates increased in line with the incubation concentration of atorvastatin. (4) The increased amount of data generated with the high throughput oil spin method, combined with a micro-rate constant mechanistic model helps to explain the inhibition of uptake by cyclosporine following pre-incubation

Star Clusters

This review concentrates almost entirely on globular star clusters. It emphasises the increasing realisation that few of the traditional problems of star cluster astronomy can be studied in isolation: the influence of the Galaxy affects dynamical evolution deep in the core, and the spectrum of stellar masses; in turn the evolution of the core determines the highest stellar densities, and the rate of encounters. In this way external tidal effects indirectly influence the formation and evolution of blue stragglers, binary pulsars, X-ray sources, etc. More controversially, the stellar density appears to influence the relative distribution of normal stars. In the opposite sense, the evolution of individual stars governs much of the early dynamics of a globular cluster, and the existence of large numbers of primordial binary stars has changed important details of our picture of the dynamical evolution. New computational tools which will become available in the next few years will help dynamical theorists to address these questions.Comment: 10 pages, 3 figures, Te

The role of rewilding in mitigating hydrological extremes: State of the evidence

Landscape rewilding has the potential to help mitigate hydrological extremes by allowing natural processes to function. Our systematic review assessed the evidence base for rewilding-driven mitigation of high and low flows. The review uncovers a lack of research directly addressing rewilding, but highlights research in analogue contexts which can, with caution, indicate the nature of change. There is a lack of before-after studies that enable deeper examination of temporal trajectories and legacy effects, and a lack of research on the scrub and shrubland habitats common in rewilding projects. Over twice as much evidence is available for high flows compared to low flows, and fewer than one third of studies address high and low flows simultaneously, limiting our understanding of co-benefits and contrasting effects. Flow magnitude variables are better represented within the literature than flow timing variables, and there is greater emphasis on modeling for high flows, and on direct measurement for low flows. Most high flow studies report a mitigating effect, but with variability in the magnitude of effect, and some exceptions. The nature of change for low flows is more complex and suggests a higher potential for increased low flow risks associated with certain trajectories but is based on a very narrow evidence base. We recommend that future research aims to: capture effects on both high and low flow extremes for a given type of change; analyze both magnitude and timing characteristics of flow extremes; and examine temporal trajectories (before and after data) ideally using a full before-after-control-impact design. This article is categorized under: Human Water > Value of Water Science of Water > Hydrological Processes Science of Water > Water Extremes Water and Life > Conservation, Management, and Awareness

Infrared Spectroscopy of Ammonia on Iron: Adsorption, Synthesis and the Influence of Oxygen

We report on reflection absorption infrared spectroscopy (RAIRS) investigations into the influence of oxygen on the surface chemistry of NH3 on Fe{111}. Pre-adsorption of oxygen is found to strengthen the interaction between ammonia and the surface, albeit at the lowest oxygen coverage examined the effect is only notable when the ammonia coverage becomes high. At higher oxygen coverage, the same effect is observed even with very low ammonia coverage. In cases where the oxygen overlayer is ordered, the effects are seen quite clearly, but for disordered overlayers the surface heterogeneity makes assignment of absorption features more difficult; nevertheless, comparison with the ordered examples allows us to identify the same underlying behaviour. When potassium is coadsorbed with oxygen, the effect on ammonia adsorption is threefold, including potassium-dominated and oxygen-dominated features, alongside features that suggest either cancelling or absent influences from the atomic adsorbates. Synthesis of ammonia from nitrogen adatoms in 0.6 mbar H2 shows clear evidence of very similar surface interactions

Flavour in supersymmetry: horizontal symmetries or wave function renormalisation

We compare theoretical and experimental predictions of two main classes of models addressing fermion mass hierarchies and flavour changing neutral currents (FCNC) effects in supersymmetry: Froggatt-Nielsen (FN) U(1) gauged flavour models and Nelson-Strassler/extra dimensional models with hierarchical wave functions for the families. We show that whereas the two lead to identical predictions in the fermion mass matrices, the second class generates a stronger suppression of FCNC effects. We prove that, whereas at first sight the FN setup is more constrained due to anomaly cancelation conditions, imposing unification of gauge couplings in the second setup generates conditions which precisely match the mixed anomaly constraints in the FN setup. Finally, we provide an economical extra dimensional realisation of the hierarchical wave functions scenario in which the leptonic FCNC can be efficiently suppressed due to the strong coupling (CFT) origin of the electron mass.Comment: 23 page

Global parameter search reveals design principles of the mammalian circadian clock

Background: Virtually all living organisms have evolved a circadian (~24 hour) clock that controls physiological and behavioural processes with exquisite precision throughout the day/night cycle. The suprachiasmatic nucleus (SCN), which generates these ~24 h rhythms in mammals, consists of several thousand neurons. Each neuron contains a gene-regulatory network generating molecular oscillations, and the individual neuron oscillations are synchronised by intercellular coupling, presumably via neurotransmitters. Although this basic mechanism is currently accepted and has been recapitulated in mathematical models, several fundamental questions about the design principles of the SCN remain little understood. For example, a remarkable property of the SCN is that the phase of the SCN rhythm resets rapidly after a 'jet lag' type experiment, i.e. when the light/ dark (LD) cycle is abruptly advanced or delayed by several hours. Results: Here, we describe an extensive parameter optimization of a previously constructed simplified model of the SCN in order to further understand its design principles. By examining the top 50 solutions from the parameter optimization, we show that the neurotransmitters' role in generating the molecular circadian rhythms is extremely important. In addition, we show that when a neurotransmitter drives the rhythm of a system of coupled damped oscillators, it exhibits very robust synchronization and is much more easily entrained to light/dark cycles. We were also able to recreate in our simulations the fast rhythm resetting seen after a 'jet lag' type experiment. Conclusion: Our work shows that a careful exploration of parameter space for even an extremely simplified model of the mammalian clock can reveal unexpected behaviours and non-trivial predictions. Our results suggest that the neurotransmitter feedback loop plays a crucial role in the robustness and phase resetting properties of the mammalian clock, even at the single neuron level

The effects of childbirth on the pelvic-floor

Basically, vaginal delivery is associated with the risk of pelvic floor damage. The pelvic floor sequelae of childbirth includes anal incontinence, urinary incontinence and pelvic organ prolapse. Pathophysiology, incidence and risk factors for the development of the respective problems are reviewed. Where possible, recommendations for reducing the risk of pelvic floor damage are given

You turn me cold: evidence for temperature contagion

Introduction During social interactions, our own physiological responses influence those of others. Synchronization of physiological (and behavioural) responses can facilitate emotional understanding and group coherence through inter-subjectivity. Here we investigate if observing cues indicating a change in another's body temperature results in a corresponding temperature change in the observer. Methods Thirty-six healthy participants (age; 22.9±3.1 yrs) each observed, then rated, eight purpose-made videos (3 min duration) that depicted actors with either their right or left hand in visibly warm (warm videos) or cold water (cold videos). Four control videos with the actors' hand in front of the water were also shown. Temperature of participant observers' right and left hands was concurrently measured using a thermistor within a Wheatstone bridge with a theoretical temperature sensitivity of <0.0001°C. Temperature data were analysed in a repeated measures ANOVA (temperature × actor's hand × observer's hand). Results Participants rated the videos showing hands immersed in cold water as being significantly cooler than hands immersed in warm water, F(1,34) = 256.67, p0.1). There was however no evidence of left-right mirroring of these temperature effects p>0.1). Sensitivity to temperature contagion was also predicted by inter-individual differences in self-report empathy. Conclusions We illustrate physiological contagion of temperature in healthy individuals, suggesting that empathetic understanding for primary low-level physiological challenges (as well as more complex emotions) are grounded in somatic simulation