SATURN'S INNER SATELLITES: ORBITS, MASSES, AND THE CHAOTIC MOTION OF ATLAS FROM NEW CASSINI IMAGING OBSERVATIONS

We present numerically-derived orbits and mass estimates for the inner Saturnian satellites, Atlas, Prometheus, Pandora, Janus and Epimetheus from a fit to 2580 new Cassini ISS astrometric observations spanning February 2004 to August 2013. The observations are provided in a supplementary table. We estimate GM_ Atlas=0.384+/-0.001 x 10^(-3)km^3s^(-2), a value 13% smaller than the previously published estimate but with an order of magnitude reduction in the uncertainty. We also find GM_ Prometheus=10.677+/-0.006x10(-3)km^3s^(-2), GM_Pandora=9.133+/-0.009x10^(-3)km^3s^(-2), GM_Janus=126.51+/-0.03x10^(-3)km^3s^(-2) and GM_Epimetheus=35.110+/-0.009x10^(-3)km^3s^(-2), consistent with previously published values, but also with significant reductions in uncertainties. We show that Atlas is currently librating in both the 54:53 co-rotation-eccentricity resonance (CER) and the 54:53 inner Lindblad (ILR) resonance with Prometheus, making it the latest example of a coupled CER-ILR system, in common with the Saturnian satellites Anthe, Aegaeon and Methone, and possibly Neptune's ring arcs. We further demonstrate that Atlas's orbit is chaotic, with a Lyapunov time of ~10 years, and show that its chaotic behaviour is a direct consequence of the coupled resonant interaction with Prometheus, rather than being an indirect effect of the known chaotic interaction between Prometheus and Pandora. We provide an updated analysis of the second-order resonant perturbations involving Prometheus, Pandora and Epimetheus based on the new observations, showing that these resonant arguments are librating only when Epimetheus is the innermost of the co-orbital pair, Janus and Epimetheus. We also find evidence that the known chaotic changes in the orbits of Prometheus and Pandora are not confined to times of apse anti-alignement.Comment: 23 pages, 16 figures. Accepted for publication in The Astronomical Journal 23 September 2014 (corrected Fig. 11

CMV in the gut: a critical review of CMV detection in the immunocompetent host with colitis.

As scientific techniques for the detection of cytomegalovirus (CMV) improve, we are able to detect small amounts of CMV in the mucosal wall. As clinicians, we are unsure how to interpret the results of this novel test. There is controversy in the literature as to the significance of the detection of CMV in the gut. Whilst the importance of CMV and reactivation of the virus is clear in those patients such as allograft recipients with established immune compromise, the role is less clear in patients with less damaged immune systems. We explore whether the detection of CMV in such cases influences outcome and how it should be optimally managed. We discuss the optimal management of such cases, according to current guidelines, with a review of the literature

Mental health and mediumship: an interpretative phenomenological analysis

There is a lack of research examining the lived experience of mental health as a practicing medium, yet the nature of mediumship work inherently presents a number of challenges to the mental health of practitioners. In this study, we aimed to gain an understanding of how mediums experience their mental health in relation to their mediumistic practice and how they recognise and respond to psychological difficulties experienced by their clients. Fourteen mediums from the North West of England took part in one-to-one interviews, which were transcribed and subject to interpretative phenomenological analysis. Four themes were identified: From past traumas to mediumistic identity; Spirit makes sense, mental illness is chaos; Being resilient but vulnerable; and Ethical mediumistic practice. The research highlights the value of not dismissing or attempting to change appraisals of valued aspects of mediums’ anomalous experiences. However, the findings do indicate that support for exposure to clients’ difficulties (such as vicarious trauma) might be helpful, in the same way in which other professionals might receive support with such experiences. Future research into mediums’ help-seeking for mental health difficulties and their experiences of counselling or psychotherapy would be valuable in identifying if and how their psychological needs are met

Sustained benefit from intravenous immunoglobulin therapy for gastrointestinal involvement in systemic sclerosis

Objective. IVIG is known to confer significant benefit in rheumatologic conditions, including inflammatory myopathy. This study aimed to assess the efficacy of IVIG across different aspects of internal organ involvement in refractory active SSc, particularly the gastrointestinal (GI) system. / Methods. SSc patients with overlap polymyositis who remained active and unresponsive to conventional disease-modifying agents and who subsequently received IVIG were identified. GI symptoms were assessed using validated questionnaires. The Medical Research Council Sum Score for muscle strength and modified Rodnan skin score (mRSS) were assessed. Serial measurements were undertaken at baseline prior to the first IVIG treatment and post-treatment in the most recent assessment. / Results. Fifteen SSc patients were consecutively recruited into this observational study. The mean duration of IVIG treatment was 2.3 years, with treatment frequency ranging from every 6 weeks to 4 months. Compared with baseline, there was a significant reduction in gastro-oesophageal reflux frequency and intensity mean scores (P = 0.006 and P = 0.013, respectively). Significant improvement in the Gastrointestinal Tract (GIT) 2.0 score from a baseline mean score of 1.07 (s.d. 0.67) to 0.60 (0.46) (P = 0.002) was observed. There was regression in the markers of muscle disease with a reduction in the mean (s.d.) Medical Research Council sum score and the median creatine kinase level (P = 0.001 and P = 0.025, respectively). Significant amelioration of the mean basal modified Rodnan skin score from 21.5 (s.d. 13.8) to 10 (10.6) (P = 0.005) was observed. / Conclusion. IVIG may be a helpful adjunctive therapy in the amelioration of some key clinical aspects in refractory SSc. Sustained benefit from IVIG suggests a specific immunomodulatory effect on those with established SSc GI complications

Hardness of Sparse Sets and Minimal Circuit Size Problem

We develop a polynomial method on finite fields to amplify the hardness of spare sets in nondeterministic time complexity classes on a randomized streaming model. One of our results shows that if there exists a $2^{n^{o(1)}}$-sparse set in $NTIME(2^{n^{o(1)}})$ that does not have any randomized streaming algorithm with $n^{o(1)}$ updating time, and $n^{o(1)}$ space, then $NEXP\not=BPP$, where a $f(n)$-sparse set is a language that has at most $f(n)$ strings of length $n$. We also show that if MCSP is $ZPP$-hard under polynomial time truth-table reductions, then $EXP\not=ZPP$

The Relationship Between Mucosal Microbiota, Colitis, and Systemic Inflammation in Chronic Granulomatous Disorder

PURPOSE: Chronic granulomatous disorder (CGD) is a primary immunodeficiency which is frequently complicated by inflammatory colitis and is associated with systemic inflammation. Herein, we aimed to investigate the role of the microbiome in the pathogenesis of colitis and systemic inflammation. METHODS: We performed 16S rDNA sequencing on mucosal biopsy samples from each segment of 10 CGD patients’ colons and conducted compositional and functional pathway prediction analyses. RESULTS: The microbiota in samples from colitis patients demonstrated reduced taxonomic alpha-diversity compared to unaffected patients, even in apparently normal bowel segments. Functional pathway richness was similar between the colitic and non-colitic mucosa, although metabolic pathways involved in butyrate biosynthesis or utilization were enriched in patients with colitis and correlated positively with fecal calprotectin levels. One patient with very severe colitis was dominated by Enterococcus spp., while among other patients Bacteroides spp. abundance correlated with colitis severity measured by fecal calprotectin and an endoscopic severity score. In contrast, Blautia abundance is associated with low severity scores and mucosal health. Several taxa and functional pathways correlated with concentrations of inflammatory cytokines in blood but not with colitis severity. Notably, dividing patients into “high” and “low” systemic inflammation groups demonstrated clearer separation than on the basis of colitis status in beta-diversity analyses. CONCLUSION: The microbiome is abnormal in CGD-associated colitis and altered functional characteristics probably contribute to pathogenesis. Furthermore, the relationship between the mucosal microbiome and systemic inflammation, independent of colitis status, implies that the microbiome in CGD can influence the inflammatory phenotype of the condition

Autoantibody predictors of gastrointestinal symptoms in systemic sclerosis

Objectives: To assess the prevalence and burden of SSc-related gastrointestinal dysfunction (SSc-GI) and to evaluate associations with demographic, clinical and serological characteristics. // Methods: Patients completed the UCLA SCTC GIT 2.0 questionnaire for SSc-GI disease to assess the burden of GI disease across multiple functional and psychological domains. Questionnaire scores were assessed using non-parametric and quantile regression analyses. // Results: Our cohort included 526 patients with SSc, with a typical distribution of disease-associated autoantibodies (ACA, ARA, ATA, PM-Scl, U1RNP, U3RNP). We demonstrated associations between hallmark antibodies and the domain-specific burden of GI disease. In particular, ACA, ARA and ENA-negative demonstrated increased SSc-GI disease burden, while PM-Scl conferred relative protection. In a distributional analysis, associations with autoantibodies were particularly marked in those with the highest burden of GI disease. // Conclusion: There is a significant burden of SSc-GI disease in patients with SSc; reflux and bloating symptoms are most prominent. SSc hallmark antibodies may predict increased risk of SSc-GI disease, in particular ACA and ARA, while PM-Scl may be protective

Disability weights for comorbidity and their influence on Health-adjusted Life Expectancy

BACKGROUND: Comorbidity complicates estimations of health-adjusted life expectancy (HALE) using disease prevalences and disability weights from Burden of Disease studies. Usually, the exact amount of comorbidity is unknown and no disability weights are defined for comorbidity. METHODS: Using data of the Dutch national burden of disease study, the effects of different methods to adjust for comorbidity on HALE calculations are estimated. The default multiplicative adjustment method to define disability weights for comorbidity is compared to HALE estimates without adjustment for comorbidity and to HALE estimates in which the amount of disability in patients with multiple diseases is solely determined by the disease that leads to most disability (the maximum adjustment method). To estimate the amount of comorbidity, independence between diseases is assumed. RESULTS: Compared to the multiplicative adjustment method, the maximum adjustment method lowers HALE estimates by 1.2 years for males and 1.9 years for females. Compared to no adjustment, a multiplicative adjustment lowers HALE estimates by 1.0 years for males and 1.4 years for females. CONCLUSION: The differences in HALE caused by the different adjustment methods demonstrate that adjusting for comorbidity in HALE calculations is an important topic that needs more attention. More empirical research is needed to develop a more general theory as to how comorbidity influences disability