Micromagnetic Domain Structures in Cylindrical Nickel Dots

The magnetic domain structures of cylindrical nickel dots (diameters from 40 nm to 1700 nm) with anisotropy parallel to the cylinder axis is predicted by the ratio of the dot diameter to the stripe period of unpatterned films with the same perpendicular anisotropy. The dominant domain structure for a given ratio increases in complexity as the ratio increases. We present evidence for the full micromagnetic domain structure for the simplest cases

Attention control comparisons with SLT for people with aphasia following stroke: methodological concerns raised following a systematic review

Objective: Attention control comparisons in trials of stroke rehabilitation require care to minimize the risk of comparison choice bias. We compared the similarities and differences in SLT and social support control interventions for people with aphasia. Data sources: Trial data from the 2016 Cochrane systematic review of SLT for aphasia after stroke. Methods: Direct and indirect comparisons between SLT, social support and no therapy controls. We double-data extracted intervention details using the template for intervention description and replication. Standardized mean differences and risk ratios (95% confidence intervals (CIs)) were calculated. Results: Seven trials compared SLT with social support (n  =  447). Interventions were matched in format, frequency, intensity, duration and dose. Procedures and materials were often shared across interventions. Social support providers received specialist training and support. Targeted language rehabilitation was only described in therapy interventions. Higher drop-out (P  =  0.005, odds ratio (OR) 0.51, 95% CI 0.32–0.81) and non-adherence to social support interventions (P  <  0.00001, OR 0.18, 95% CI 0.09–0.37) indicated an imbalance in completion rates increasing the risk of control comparison bias. Conclusion: Distinctions between social support and therapy interventions were eroded. Theoretically based language rehabilitation was the remaining difference in therapy interventions. Social support is an important adjunct to formal language rehabilitation. Therapists should continue to enable those close to the person with aphasia to provide tailored communication support, functional language stimulation and opportunities to apply rehabilitation gains. Systematic group differences in completion rates is a design-related risk of bias in outcomes observed

Brightest galaxies as halo centre tracers in SDSS DR7

Determining the positions of halo centres in large-scale structure surveys is crucial for many cosmological studies. A common assumption is that halo centres correspond to the location of their brightest member galaxies. In this paper, we study the dynamics of brightest galaxies with respect to other halo members in the Sloan Digital Sky Survey DR7. Specifically, we look at the line-of-sight velocity and spatial offsets between brightest galaxies and their neighbours. We compare those to detailed mock catalogues, constructed from high-resolution, dark-matter-only $N$-body simulations, in which it is assumed that satellite galaxies trace dark matter subhaloes. This allows us to place constraints on the fraction $f_{\rm BNC}$ of haloes in which the brightest galaxy is not the central. Compared to previous studies we explicitly take into account the unrelaxed state of the host haloes, velocity offsets of halo cores and correlations between $f_{\rm BNC}$ and the satellite occupation. We find that $f_{\rm BNC}$ strongly decreases with the luminosity of the brightest galaxy and increases with the mass of the host halo. Overall, in the halo mass range $10^{13} - 10^{14.5} h^{-1} M_\odot$ we find $f_{\rm BNC} \sim 30\%$, in good agreement with a previous study by Skibba et al. We discuss the implications of these findings for studies inferring the galaxy--halo connection from satellite kinematics, models of the conditional luminosity function and galaxy formation in general.Comment: 24 pages, 15 figures. Accepted for publication in MNRA

Phonon lasing from optical frequency comb illumination of a trapped ion

An atomic transition can be addressed by a single tooth of an optical frequency comb if the excited state lifetime ($\tau$) is significantly longer than the pulse repetition period ($T_\mathrm{r}$). In the crossover regime between fully-resolved and unresolved comb teeth ($\tau \lessapprox T_\mathrm{r}$), we observe Doppler cooling of a pre-cooled trapped atomic ion by a single tooth of a frequency-doubled optical frequency comb. We find that for initially hot ions, a multi-tooth effect gives rise to lasing of the ion's harmonic motion in the trap, verified by acoustic injection locking. The gain saturation of this phonon laser action leads to a comb of steady-state oscillation amplitudes, allowing hot ions to be loaded directly into the trap and laser cooled to crystallization despite the presence of hundreds of blue-detuned teeth.Comment: 5 pages, 4 figure

Troubling stoicism:Sociocultural influences and applications to health and illness behaviour

In light of the ambiguity of meanings attributed to the concept of stoicism we critically explore its use as a label to explain and describe health and illness behaviour, juxtaposing the often negative portrayals of contemporary stoicism against its classical and philosophical origins. By reflecting critically on the term ‘stoicism’, its application and dimensionality, we show how the term has evolved from classical to contemporary times in relation to changing context, and explore different understandings of the term across medical and health literature. We attend to sociocultural factors that are seen to influence the conceptualization of stoicism such as generational influences, gender and geographies. We make the assertion that by applying the label of ‘stoicism’ as it is known today, there is a danger of too readily accepting a term that masks particular health behaviours while missing an array of sociological factors that are important to how people deal with adversity arising from chronic health problems. We therefore encourage further questioning of this term. </jats:p

The initiator methionine tRNA drives cell migration and invasion leading to increased metastatic potential in melanoma

The cell's repertoire of transfer RNAs (tRNAs) has been linked to cancer. Recently, levels of the initiator methionine tRNA (tRNAiMet) in stromal fibroblasts have been shown to influence extracellular matrix (ECM) secretion to drive tumour growth and angiogenesis. Here we show that increased tRNAiMet within cancer cells does not influence tumour growth, but drives cell migration and invasion via a mechanism that is independent from ECM synthesis and dependent on α5β1 integrin and levels of the translation initiation ternary complex. In vivo and ex vivo migration (but not proliferation) of melanoblasts is significantly enhanced in transgenic mice which express additional copies of the tRNAiMet gene. We show that increased tRNAiMet in melanoma drives migratory, invasive behaviour and metastatic potential without affecting cell proliferation and primary tumour growth, and that expression of RNA polymerase III-associated genes (which drive tRNA expression) are elevated in metastases by comparison with primary tumours. Thus specific alterations to the cancer cell tRNA repertoire drive a migration/invasion programme that may lead to metastasis