The Magnetic Field of the Solar Corona from Pulsar Observations

We present a novel experiment with the capacity to independently measure both the electron density and the magnetic field of the solar corona. We achieve this through measurement of the excess Faraday rotation due to propagation of the polarised emission from a number of pulsars through the magnetic field of the solar corona. This method yields independent measures of the integrated electron density, via dispersion of the pulsed signal and the magnetic field, via the amount of Faraday rotation. In principle this allows the determination of the integrated magnetic field through the solar corona along many lines of sight without any assumptions regarding the electron density distribution. We present a detection of an increase in the rotation measure of the pulsar J1801$-$2304 of approximately 160 \rad at an elongation of 0.95$^\circ$ from the centre of the solar disk. This corresponds to a lower limit of the magnetic field strength along this line of sight of $> 393\mu\mathrm{G}$. The lack of precision in the integrated electron density measurement restricts this result to a limit, but application of coronal plasma models can further constrain this to approximately 20mG, along a path passing 2.5 solar radii from the solar limb. Which is consistent with predictions obtained using extensions to the Source Surface models published by Wilcox Solar ObservatoryComment: 16 pages, 4 figures (1 colour): Submitted to Solar Physic

High-velocity microsprays enhance antimicrobial activity in S. mutans biofilms

Streptococcus mutans in dental plaque biofilms play a role in caries development. The biofilm’s complex structure enhances the resistance to antimicrobial agents by limiting the transport of active agents inside the biofilm. We assessed the ability of high-velocity water microsprays to enhance delivery of antimicrobials into 3-days old S. mutans biofilms. Biofilms were exposed to a 90° or 30° impact, firstly using a 1-?m tracer beads solution (109 beads/mL) and secondly, a 0.2% Chlorhexidine (CHX) or 0.085% Cetylpyridinium chloride (CPC) solution. For comparison, a 30-sec diffusive transport and simulated mouthwash were also performed. Confocal microscopy was used to determine number and relative bead penetration depth (RD) into the biofilm. Assessment of antimicrobial penetration was determined by calculating the killing depth (KD) detected by live/dead viability staining. We firstly demonstrated that the microspray was able to deliver significantly more microbeads deeper in the biofilm compared to diffusion and mouthwashing exposures. Next our experiments revealed that the microspray yielded better antimicrobial penetration evidenced by deeper killing inside the biofilm and a wider killing zone around the zone of clearance than a diffusion transport with the same antimicrobials. Interestingly the 30° impact in the distal position delivered approximately 16 times more microbeads and yielded approximately 20% more bacteria killing (for both CHX and CPC) than the 90o impact. These data suggest that high-velocity water microsprays can be used as an effective mechanism to deliver micro-particles and antimicrobials inside S. mutans biofilms. High shear stresses generated at the biofilm/burst interface might have enhanced beads and antimicrobials delivery inside the remaining biofilm by combining forced advection into the biofilm matrix and physical restructuring of the biofilm itself. Further, the impact angle has potential to be optimized both for biofilm removal and active agents’ delivery inside biofilm in those protected areas where some biofilm might remai

A system of ODEs for a Perturbation of a Minimal Mass Soliton

We study soliton solutions to a nonlinear Schrodinger equation with a saturated nonlinearity. Such nonlinearities are known to possess minimal mass soliton solutions. We consider a small perturbation of a minimal mass soliton, and identify a system of ODEs similar to those from Comech and Pelinovsky (2003), which model the behavior of the perturbation for short times. We then provide numerical evidence that under this system of ODEs there are two possible dynamical outcomes, which is in accord with the conclusions of Pelinovsky, Afanasjev, and Kivshar (1996). For initial data which supports a soliton structure, a generic initial perturbation oscillates around the stable family of solitons. For initial data which is expected to disperse, the finite dimensional dynamics follow the unstable portion of the soliton curve.Comment: Minor edit

Magnetic Fields in the Milky Way

This chapter presents a review of observational studies to determine the magnetic field in the Milky Way, both in the disk and in the halo, focused on recent developments and on magnetic fields in the diffuse interstellar medium. I discuss some terminology which is confusingly or inconsistently used and try to summarize current status of our knowledge on magnetic field configurations and strengths in the Milky Way. Although many open questions still exist, more and more conclusions can be drawn on the large-scale and small-scale components of the Galactic magnetic field. The chapter is concluded with a brief outlook to observational projects in the near future.Comment: 22 pages, 5 figures, to appear in "Magnetic Fields in Diffuse Media", eds. E.M. de Gouveia Dal Pino and A. Lazaria

A Framework for Multi-Omic Prediction of Treatment Response to Biologic Therapy for Psoriasis.

Biologic therapies have shown high efficacy in psoriasis, but individual response varies and is poorly understood. To inform biomarker discovery in the Psoriasis Stratification to Optimise Relevant Therapy (i.e., PSORT) study, we evaluated a comprehensive array of omics platforms across three time points and multiple tissues in a pilot investigation of 10 patients with severe psoriasis, treated with the tumor necrosis factor (TNF) inhibitor, etanercept. We used RNA sequencing to analyze mRNA and small RNA transcriptome in blood, lesional and nonlesional skin, and the SOMAscan platform to investigate the serum proteome. Using an integrative systems biology approach, we identified signals of treatment response in genes and pathways associated with TNF signaling, psoriasis pathology, and the major histocompatibility complex region. We found association between clinical response and TNF-regulated genes in blood and skin. Using a combination of differential expression testing, upstream regulator analysis, clustering techniques, and predictive modeling, we show that baseline samples are indicative of patient response to biologic therapies, including signals in blood, which have traditionally been considered unreliable for inference in dermatology. In conclusion, our pilot study provides both an analytical framework and empirical basis to estimate power for larger studies, specifically the ongoing PSORT study, which we show as powered for biomarker discovery and patient stratification

Light microscopic observations of the ruminal papillae of cattle on diets with divergent forage to cereal ratios

High levels of supplementation with cereal increases production rates in cattle but can increase incidence of disease, ranging from mild indigestion to acute ruminal acidosis and death. Therefore, there is motivation to determine biological markers which can be used to identify whether animals have been, or are being fed, sufficient or excessive cereals. This study aimed to describe light microscopic findings from animals being fed diverse dietary cereal proportions and to test the performance of a novel rumen epithelial scoring system. Rumen wall tissue samples were obtained from the abattoir from 195 cattle from 11 Scottish farms and processed for histological examination. Light microscopic examination was used to characterise ruminal epithelial response to dietary challenge. Secondary objectives included describing the distribution of immune-related cells in bovine ruminal epithelium and assessing the use of a modified Elastin Martius Scarlet Blue stain (EMSB) for histological examination of the rumen epithelium. Cells staining positive for cluster of differentiation 3 were distributed mainly in the lower layers of the stratum basale and were found in higher densities in animals offered lower cereal proportion diets. Cells staining positive for major histocompatibility complex class 2 (MHCII) were most common in perivascular locations and in the junction between the lower stratum basale and the propria-submucosa. The density of MHCII positive staining cells was higher in animals on lower cereal diets. The level of supplementation with cereal was also associated with the thickness of the stratum corneum (SCT) and stratum granulosum (SGT), the integrity of the stratum corneum and sloughing of cornified cells. There were no advantages in using EMSB stain over haematoxylin and eosin (H and E) in this scoring system. We concluded that a scoring system that included only SCT, SGT and a measure of the loss of appearance of intercellular space allowed differentiation of groups of animals according to the level of cereal supplementation

Social and clinical determinants of preferences and their achievement at the end of life: Prospective cohort study of older adults receiving palliative care in three countries

© 2017 The Author(s). Background: Achieving choice is proposed as a quality marker. But little is known about what influences preferences especially among older adults. We aimed to determine and compare, across three countries, factors associated with preferences for place of death and treatment, and actual site of death. Methods: We recruited adults aged ≥65-years from hospital-based multiprofessional palliative care services in London, Dublin, New York, and followed them for >17 months. All services offered consultation on hospital wards, support for existing clinical teams, outpatient services and received funding from their National Health Service and/or relevant Insurance reimbursements. The New York service additionally had 10 inpatient beds. All worked with and referred patients to local hospices. Face-to-face interviews recorded most and least preferred place of death, treatment goal priorities, demographic and clinical information using validated questionnaires. Multivariable and multilevel analyses assessed associated factors. Results: One hundred and thirty eight older adults (64 London, 59 Dublin, 15 New York) were recruited, 110 died during follow-up. Home was the most preferred place of death (77/138, 56%) followed by inpatient palliative care/hospice units (22%). Hospital was least preferred (35/138, 25%), followed by nursing home (20%) and home (16%); hospice/palliative care unit was rarely least preferred (4%). Most respondents prioritised improving quality of life, either alone (54%), or equal with life extension (39%); few (3%) chose only life extension. There were no significant differences between countries. Main associates with home preference were: cancer diagnosis (OR 3.72, 95% CI 1.40-9.90) and living with someone (OR 2.19, 1.33-3.62). Adults with non-cancer diagnoses were more likely to prefer palliative care units (OR 2.39, 1.14-5.03). Conversely, functional independence (OR 1.05, 1.04-1.06) and valuing quality of life (OR 3.11, 2.89-3.36) were associated with dying at home. There was a mismatch between preferences and achievements - of 85 people who preferred home or a palliative care unit, 19 (25%) achieved their first preference. Conclusion: Although home is the most common first preference, it is polarising and for 16% it is the least preferred. Inpatient palliative care unit emerges as the second most preferred place, is rarely least preferred, and yet was often not achieved for those who wanted to die there. Factors affecting stated preferences and met preferences differ. Available services, notably community support and palliative care units, require expansion. Contrasting actual place of death with capacity for meeting patient and family needs may be a better quality indicator than simply 'achieved preferences'

A High Statistics Search for Ultra-High Energy Gamma-Ray Emission from Cygnus X-3 and Hercules X-1

We have carried out a high statistics (2 Billion events) search for ultra-high energy gamma-ray emission from the X-ray binary sources Cygnus X-3 and Hercules X-1. Using data taken with the CASA-MIA detector over a five year period (1990-1995), we find no evidence for steady emission from either source at energies above 115 TeV. The derived upper limits on such emission are more than two orders of magnitude lower than earlier claimed detections. We also find no evidence for neutral particle or gamma-ray emission from either source on time scales of one day and 0.5 hr. For Cygnus X-3, there is no evidence for emission correlated with the 4.8 hr X-ray periodicity or with the occurrence of large radio flares. Unless one postulates that these sources were very active earlier and are now dormant, the limits presented here put into question the earlier results, and highlight the difficulties that possible future experiments will have in detecting gamma-ray signals at ultra-high energies.Comment: 26 LaTeX pages, 16 PostScript figures, uses psfig.sty to be published in Physical Review