Properties of some five dimensional Einstein metrics

The volumes, spectra and geodesics of a recently constructed infinite family of five-dimensional inhomogeneous Einstein metrics on the two $S^3$ bundles over $S^2$ are examined. The metrics are in general of cohomogeneity one but they contain the infinite family of homogeneous metrics $T^{p,1}$. The geodesic flow is shown to be completely integrable, in fact both the Hamilton-Jacobi and the Laplace equation separate. As an application of these results, we compute the zeta function of the Laplace operator on $T^{p,1}$ for large $p$. We discuss the spectrum of the Lichnerowicz operator on symmetric transverse tracefree second rank tensor fields, with application to the stability of Freund-Rubin compactifications and generalised black holes.Comment: 1+43 pages, 2 figures, LaTeX. Minor typos correcte

Defining Microbiome Health through a Host Lens.

We are walking ecosystems, inoculated at birth with a unique set of microbes that are integral to the functioning of our bodies. The physiology of our commensal microbiota is intertwined with our metabolism, immune function, and mental state. The specifics of this entanglement remain largely unknown and are somewhat unique to individuals, and when any one piece of this complex system breaks, our health can suffer. There appear to be many ways to build a healthy, functional microbiome and several distinct ways in which it can break. Despite the hundreds of associations with human disease, there are only a handful of cases where the exact contribution of the microbiome to the etiology of disease is known. Our laboratory takes a systems approach, integrating dynamic high-throughput host phenotyping with eco-evolutionary dynamics and metabolism of gut microbiota to better define health and disease for each individual at the ecosystem level

Microbial diversity - exploration of natural ecosystems and microbiomes

© The Author(s), 2015. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Current Opinion in Genetics & Development 35 (2015): 66-72, doi:10.1016/j.gde.2015.10.003.Microorganisms are the pillars of life on Earth. Over billions of years, they have evolved into every conceivable niche on the planet. Microbes reshaped the oceans and atmosphere and gave rise to conditions conducive to multicellular organisms. Only in the past decade have we started to peer deeply into the microbial cosmos, and what we have found is amazing. Microbial ecosystems behave, in many ways, like large-scale ecosystems, although there are important exceptions. We review recent advances in our understanding of how microbial diversity is distributed across environments, how microbes influence the ecosystems in which they live, and how these nano-machines might be harnessed to advance our understanding of the natural world.S.M.G. was supported by an EPA STAR Graduate Fellowship and by NIH training grant 5T-32EB-009412.2016-11-1

MICOM: Metagenome-Scale Modeling To Infer Metabolic Interactions in the Gut Microbiota.

Compositional changes in the gut microbiota have been associated with a variety of medical conditions such as obesity, Crohn\u27s disease, and diabetes. However, connecting microbial community composition to ecosystem function remains a challenge. Here, we introduce MICOM, a customizable metabolic model of the human gut microbiome. By using a heuristic optimization approach based on L2 regularization, we were able to obtain a unique set of realistic growth rates that corresponded well with observed replication rates. We integrated adjustable dietary and taxon abundance constraints to generate personalized metabolic models for individual metagenomic samples. We applied MICOM to a balanced cohort of metagenomes from 186 people, including a metabolically healthy population and individuals with type 1 and type 2 diabetes. Model results showed that individual bacterial genera maintained conserved niche structures across humans, while the community-level production of short-chain fatty acids (SCFAs) was heterogeneous and highly individual specific. Model output revealed complex cross-feeding interactions that would be difficult to measur

Axisymmetric non-abelian BPS monopoles from G_2 metrics

Exact $SU(2)\times U(1)$ self-gravitating BPS global monopoles in four dimensions are constructed by dimensional reduction of eight dimensional metrics with $G_2$ holonomy asymptotic to cones over $S^3\times S^3$. The solutions carry two topological charges in an interesting way. They are generically axially but not spherically symmetric. This last fact is related to the isometries and asymptotic topology of the $G_2$ metrics. It is further shown that some $G_2$ metrics known numerically reduce to supersymmetric cosmic strings.Comment: Latex. 1+21 pages. References update

Sub-classification based specific movement control exercises are superior to general exercise in sub-acute low back pain when both are combined with manual therapy: A randomized controlled trial

Background: Clinical guidelines recommend research on sub-groups of patients with low back pain (LBP) but, to date, only few studies have been published. One sub-group of LBP is movement control impairment (MCI) and clinical tests to identify this sub-group have been developed. Also, exercises appear to be beneficial for the management of chronic LBP (CLBP), but very little is known about the management of sub-acute LBP. Methods: A randomized controlled trial (RCT) was conducted to compare the effects of general exercise versus specific movement control exercise (SMCE) on disability and function in patients with MCI within the recurrent sub-acute LBP group. Participants having a MCI attended five treatment sessions of either specific or general exercises. In both groups a short application of manual therapy was applied. The primary outcome was disability, assessed by the Roland-Morris Disability Questionnaire (RMDQ). The measurements were taken at baseline, immediately after the three months intervention and at twelve-month follow-up. Results: Seventy patients met the inclusion criteria and were eligible for the trial. Measurements of 61 patients (SMCE n = 30 and general exercise n = 31) were completed at twelve months. (Drop-out rate 12.9 %). Patients in both groups reported significantly less disability (RMDQ) at twelve months follow-up. However, the mean Change on the RMDQ between baseline and the twelve-month measurement showed statistically significantly superior improvement for the SMCE group -1.9 points (-3.9 to -0.5) 95 % (CI). The result did not reach the clinically significant three point difference. There was no statistical difference between the groups measured with Oswestry Disability Index (ODI). Conclusion: For subjects with non-specific recurrent sub-acute LBP and MCI an intervention consisting of SMCE and manual therapy combined may be superior to general exercise combined with manual therapy. Trial registration: The study protocol registration number is ISRCTN48684087. It was registered retrospectively 18th Jan 2012