Nutrition and the gastrointestinal tract

In this year’s issue, we again have a high-calibre collection of topical reviews. Gracie and Ford commence with an assessment of the role of symbiotics (i.e. probiotics and prebiotics given together) in patients with irritable bowel syndrome. They first review the many randomized trials of probiotics and the significant and persistent reductions in symptoms that (on balance) these yield – that may persist after the end of treatment. Pain, bloating and flatulence are all better than with placebo with a range of different regimens. However, although symbiotics appear promising, their current conclusion is that the evidence for superiority over probiotics alone is lacking. Jin and Vos then consider the pathophysiology of nonalcoholic fatty liver disease and specifically the role of fructose. Their synthesis of the literature includes the conclusion that unregulated lipogenesis is key to nonalcoholic fatty liver disease, linked to generalized increases in visceral adiposity – in turn probably secondary to changes in the intestinal microbiota. Dietary fructose seems an important determinant of these phenomena, and early-in-life exposure appears of most significance. Although dogmatic advice is not justified, continuing to argue for limitation of dietary fructose seems wise. Barrett et al. consider the immune response in patients on artificial nutrition in the current context wherein we aim for enteral nutrition whenever possible – thus recognizing that patients who need parenteral nutrition are then an especially high-risk group. They conclude from AQ3 a wide consideration of animal and human data that the intestinal epithelial barrier is significantly compromised and to a clinically relevant extent in patients on exclusive parenteral nutrition. They encourage targeted new work to exploit the mechanisms that have now been unearthed, such that future parenteral nutrition could be used with fewer adverse immunological consequences. Plank and Russell look at nutrition in liver transplantation incorporating new data from patients with concomitantmorbid obesity. It is of course clear that obesity is a perioperative risk factor but we lack proof that pretransplant weight loss would change this. The main issue here is probably the sarcopenic element, and weight loss without muscle preservation (or growth) would be unlikely to help. As obese patients are AQ4 being transplanted, better data are clearly needed to guide optimal nutritional strategies. After a comprehensive review on the state of the art on gluten sensitivity in the absence of coeliac disease by David Sanders, the issue finishes with a intriguing article by Murphy et al. in which they consider the evidence that chronic disease is made more likely by changes in the gut microbiota driven by a high-fat diet. Although dysbiosis is present and linked to obesity, on present evidence, this falls short of a direct causal relationship. We feel confident that readers will find plenty to provoke thought and hopefully to stimulate research in the many loci where data are sparse or inconclusive

Compatible Weighted Proper Scoring Rules

Many proper scoring rules such as the Brier and log scoring rules implicitly reward a probability forecaster relative to a uniform baseline distribution. Recent work has motivated weighted proper scoring rules, which have an additional baseline parameter. To date two families of weighted proper scoring rules have been introduced, the weighted power and pseudospherical scoring families. These families are compatible with the log scoring rule: when the baseline maximizes the log scoring rule over some set of distributions, the baseline also maximizes the weighted power and pseudospherical scoring rules over the same set. We characterize all weighted proper scoring families and prove a general property: every proper scoring rule is compatible with some weighted scoring family, and every weighted scoring family is compatible with some proper scoring rule

The Atmospheric Tides Middle Atmosphere Program (ATMAP)

Atmospheric tides, oscillations in meteorological fields occurring at subharmonics of a solar or lunar day, comprise a major component of middle atmosphere global dynamics. The purpose of the 1982 to 1986 Atmospheric Tides Atmosphere Program (ATMAP) was to foster an interaction between experimentalists, data analysts, and theoreticians and modelers, in order to better understand the physical mechanisms governing tides and their relationships to other scales of motion, and to thereby explain features of observed tidal structures in the mesosphere and lower thermosphere. The ATMAP consisted of seven observational campaigns, five workshops and a climatological study. A historical perspective is provided along with a summary of major results, conclusions, and recommendations for future study which have emerged from the ATMAP

Reviewing the effects of food provisioning on wildlife immunity

While urban expansion increasingly encroaches on natural habitats, many wildlife species capitalize on anthropogenic food resources, which have the potential to both positively and negatively influence their responses to infection. Here we examine how food availability and key nutrients have been reported to shape innate and adaptive immunity in wildlife by drawing from field-based studies, as well as captive and food restriction studies with wildlife species. Examples of food provisioning and key nutrients enhancing immune function were seen across the three study type distinctions, as were cases of trace metals and pharmaceuticals impairing the immunity of wildlife species. More generally, food provisioning in field studies tended to increase innate and adaptive responses to certain immune challenges, whereas patterns were less clear in captive studies. Mild food restriction often enhanced, whereas severe food restriction frequently impaired immunity. However, to enable stronger conclusions we stress a need for further research, especially field studies, and highlight the importance of integrating nutritional manipulation, immune challenge, and functional outcomes. Despite current gaps in research on this topic, modern high throughput molecular approaches are increasingly feasible for wildlife studies and offer great opportunities to better understand human influences on wildlife health.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'

MST radar detection of middle atmosphere tides

Meteorological and dynamical requirements pertaining to the specification of middle atmosphere tides by the MST radar technique are outlined. Major issues addressed include: (1) the extraction of tidal information from measurements covering a fraction of a day; (2) the ramifications of transient effects (tidal variability) on the determination and interpretation of tides; (3) required temporal and spatial resolutions and; (4) global distributions of MST radars, so as to complement existing MST, meteor wind, and partial reflection drift radar locations

Mirror Map as Generating Function of Intersection Numbers: Toric Manifolds with Two K\"ahler Forms

In this paper, we extend our geometrical derivation of expansion coefficients of mirror maps by localization computation to the case of toric manifolds with two K\"ahler forms. Especially, we take Hirzebruch surfaces F_{0}, F_{3} and Calabi-Yau hypersurface in weighted projective space P(1,1,2,2,2) as examples. We expect that our results can be easily generalized to arbitrary toric manifold.Comment: 45 pages, 2 figures, minor errors are corrected, English is refined. Section 1 and Section 2 are enlarged. Especially in Section 2, confusion between the notion of resolution and the notion of compactification is resolved. Computation under non-zero equivariant parameters are added in Section

Mass-energy balance for an S-1C rocket exhaust cloud during static firing

Rocket exhaust cloud mass-energy balance measurements for Saturn S1-C static firin

On the thermal durability of solar prominences, or how to evaporate a prominence

The thermal disappearance of solar prominences under strong perturbations due to wave heating, Ohmic heating, viscous heating or conduction was investigated. Specifically, how large a thermal perturbation is needed to destroy a stable thermal equilibrium was calculated. It was found that the prominence plasma appears to be thermally very rugged. Its cold equilibrium may most likely be destroyed by either strong magnetic heating or conduction in a range of parameters which is relevant to flares

Can prominences form in current sheets

Two-dimensional numerical simulations of the formation of cold condensations in a vertical current sheet have been performed using the radiative, resistive MHD equations with line-tied boundary conditions at one end of the sheet. Prominence-like condensations are observed to appear above and below an X-line produced by the onset of the tearing-mode instability. Cooling in the sheet is initiated by Ohmic decay, with the densest condensations occurring in the region downstream of a fast-mode shock. This shock, which is due to the line-tied boundary conditions, terminates one of the two supermagnetosonic reconnection jets that develop when the tearing is fully developed. The condensation properties of shock waves, which may trigger or considerably enhance the conditions for thermal condensation are emphasized