Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands

Acknowledgements This work contributes to the N-Circle project (grant number BB/N013484/1), and CINAg (BB/N013468/1) Virtual Joint Centres on Agricultural Nitrogen (funded by the Newton Fund via UK BBSRC/NERC), U-GRASS (grant number NE/M016900/1), the Belmont Forum/FACCE-JPI DEVIL project (grant number NE/M021327/1), Soils-R-GGREAT (grant number NE/P019455/1), ADVENT (grant number NE/M019713/1), Sêr Cymru LCEE-NRN project, Climate-Smart Grass and the Scottish Government’s Strategic Research Programme.Peer reviewedPublisher PD

Implications of Variability Patterns observed in TeV Blazars on the Structure of the Inner Jet

The recent long look X-ray observations of TeV blazars have revealed many important new features concerning their time variability. In this paper, we suggest a physical interpretation for those features based on the framework of the internal and external shock scenarios. We present a simplified model applicable to TeV blazars, and investigate through simulations how each of the model parameters would affect to the observed light curve or spectrum. In particular, we show that the internal shock scenario naturally leads to all the observed variability properties including the structure function, but for it to be applicable, the fractional fluctuation of the initial bulk Lorentz factors must be small, with sigma_gamma / gamma_average < 0.01. This implies very low dynamical efficiency of the internal shock scenario. We also suggest that several observational quantities -- such as the characteristic time scale, the relative amplitude of flares as compared to the steady (``offset'') component, and the slope of the structure function -- can be used to probe the inner jet. The results are applied to the TeV blazar Mrk421, and this, within the context of the model, leads to the determination of several physical parameters: the ejection of a shell with average thickness of ~1E13 cm occurs on average every 10 minutes, and the shells collide ~1E17 cm away from the central source.Comment: 12 pages, 13 figures, to appear in Ap

`In pursuit of the Nazi mind?' the deployment of psychoanalysis in the allied struggle against Germany

This paper discusses how psychoanalytic ideas were brought to bear in the Allied struggle against the Third Reich and explores some of the claims that were made about this endeavour. It shows how a variety of studies of Fascist psychopathology, centred on the concept of superego, were mobilized in military intelligence, post-war planning and policy recommendations for ‘denazification’. Freud's ideas were sometimes championed by particular army doctors and government planners; at other times they were combined with, or displaced by, competing, psychiatric and psychological forms of treatment and diverse studies of the Fascist ‘personality’. This is illustrated through a discussion of the treatment and interpretation of the deputy leader of the Nazi Party, Rudolf Hess, after his arrival in Britain in 1941

Lyman alpha absorption lines from mini pancakes

[Abridged abstract:] Recent numerical simulations show that many \lyal absorption lines of column densities \nha \la 10^{15} cm$^{-2}$ are produced in transient, mini pancakes. Such pancakes are modeled here, approximating the initial perturbation leading to the formation of the pancake as a single sinusoidal wave. The density and temperature profiles of the gas in the pancake are determined for $z_c \sim 3$, where $z_c$ is the collapse redshift. The \lyal absorption line profiles for a line of sight through the pancake are then calculated. The absorption lines in general have wings signifying bulk motions in the gas. It is shown that the deviation from a single Voigt profile is large for small H I column density lines, in which the effect of bulk motions is large. For lines with \nha > 10^{13} cm$^{-2}$, high temperature tend to wash out the signatures of bulk motion. The analytical modeling of mini pancakes associated with \lyal forest lines --- with 10^{13} \la \nha \la 10^{15} cm$^{-2}$---gives the corresponding mass scales. It is shown here that, for typical values of cosmological parameters, absorption lines with \nha \sim 10^{14} cm$^{-2}$ correspond to structures with baryonic mass of $M_b \sim 10^{10}$ M$_{\odot}$ with an overdensity of $\sim 10$ at $z \sim 3$. The value of \nha can change by a factor $\sim 3$ in the course of evolution of the pancake in time. It is also shown that there is an upper limit to \nha from a pancake due to the slow recombination rate and the importance of collisional ionization at high temperatures. Mini pancakes do not give rise to \lyal lines with \nha \ga 10^{14.5} cm$^{-2}$, for \j21=1 and $\Omega_{IGM} \sim 0.03$.Comment: Latex with aaspp4.sty (25 pages), 6 figures, Accepted for publication in The Astrophysical Journa

The Pulsar Wind Nebula Around PSR B1853+01 in the Supernova Remnant W44

We present radio observations of a region in the vicinity of the young pulsar PSR B1853+01 in the supernova remnant W44. The pulsar is located at the apex of an extended feature with cometary morphology. We argue on the basis of its morphology and its spectral index and polarization properties that this is a synchrotron nebula produced by the spin down energy of the pulsar. The geometry and physical parameters of this pulsar-powered nebula and W44 are used to derive three different measures of the pulsar's transverse velocity. A range of estimates between 315 and 470 km/s are derived, resulting in a typical value of 375 km/s. The observed synchrotron spectrum from radio to X-ray wavelengths is used to put constraints on the energetics of the nebula and to derive the parameters of the pulsar wind.Comment: ApJ Let (in press

Back pain in Portuguese schoolchildren: prevalence and risk factors

2 Centre of Research, Education, Innovation and Intervention In Sport, Faculty of Sport, University of Porto, Portugal Background: Regarding children aged _10 years, only a few international studies were conducted to determine the prevalence of and risk factors for back pain. Although other studies on the older Portuguese children point to prevalence between 17% and 39%, none exists for this specific age-group. Thus, the aim of this study was conducted to establish the prevalence of and risk factors for back pain in schoolchildren aged 7–10 years. Methods: A cross-sectional survey among 637 children was conducted. A self-rating questionnaire was used to verify prevalence and duration of back pain, life habits, school absence, medical treatments or limitation of activities. For posture assessment, photographic records with a bio-photogrammetric analysis were used to obtain data about head, acromion and pelvic alignment, horizontal alignment of the scapulae, vertical alignment of the trunk and vertical body alignment. Results: Postural problems were found in 25.4% of the children, especially in the 8- and 9-year-old groups. Back pain occurs in 12.7% with the highest values among the 7- and 10-year-old children. The probability of back pain increased 7 times when the children presented a history of school absences, 4.3 times when they experienced sleeping difficulties, 4.4 times when school furniture was uncomfortable, 4.7 times if the children perceived an occurrence of parental back pain and 2.5 times when children presented incorrect posture. Conclusions: The combination of school absences, parental pain, sleeping difficulties, inappropriate school furniture and postural deviations at the sagittal and frontal planes seem to prove the multifactorial aetiology of back pain

GeV Photons from Ultra High Energy Cosmic Rays accelerated in Gamma Ray Bursts

Gamma-ray bursts are produced by the dissipation of the kinetic energy of a highly relativistic fireball, via the formation of a collisionless shock. When this happens, Ultra High Energy Cosmic Rays up to 10^20 eV are produced. I show in this paper that these particles produce, via synchrotron emission as they cross the acceleration region, photons up to 300 GeV which carry away a small, ~0.01, but non-negligible fraction of the total burst energy. I show that, when the shock occurs with the interstellar medium, the optical depth to photon-photon scattering, which might cause energy degradation of the photons, is small. The burst thusly produced would be detected at Earth simultaneoulsy with the parent gamma-ray burst, although its duration may differ significantly from that of the lower energy photons. The expected fluences, ~10^{-5}-10^{-6} erg/cm^2 are well within the range of planned detectors. A new explanation for the exceptional burst GRB 940217 is discussed.Comment: Accepted for publication in The Physical Review Letters. 4 pages, RevTeX needed, no figure

Whole grain cereals for the primary or secondary prevention of cardiovascular disease

Background: There is evidence from observational studies that whole grains can have a beneficial effect on risk for cardiovascular disease (CVD). Earlier versions of this review found mainly short-term intervention studies. There are now longer-term randomised controlled trials (RCTs) available. This is an update and expansion of the original review conducted in 2007. Objectives:The aim of this systematic review was to assess the effect of whole grain foods or diets on total mortality, cardiovascular events, and cardiovascular risk factors (blood lipids, blood pressure) in healthy people or people who have established cardiovascular disease or related risk factors, using all eligible RCTs. Search methods: We searched CENTRAL (Issue 8, 2016) in the Cochrane Library, MEDLINE (1946 to 31 August 2016), Embase (1980 to week 35 2016), and CINAHL Plus (1937 to 31 August 2016) on 31 August 2016. We also searched ClinicalTrials.gov on 5 July 2017 and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) on 6 July 2017. We checked reference lists of relevant articles and applied no language restrictions. Selection criteria: We selected RCTs assessing the effects of whole grain foods or diets containing whole grains compared to foods or diets with a similar composition, over a minimum of 12 weeks, on cardiovascular disease and related risk factors. Eligible for inclusion were healthy adults, those at increased risk of CVD, or those previously diagnosed with CVD. Data collection and analysis: Two review authors independently selected studies. Data were extracted and quality-checked by one review author and checked by a second review author. A second review author checked the analyses. We assessed treatment effect using mean difference in a fixed-effect model and heterogeneity using the I2 statistic and the Chi2 test of heterogeneity. We assessed the overall quality of evidence using GRADE with GRADEpro software. Main results: We included nine RCTs randomising a total of 1414 participants (age range 24 to 70; mean age 45 to 59, where reported) to whole grain versus lower whole grain or refined grain control groups. We found no studies that reported the effect of whole grain diets on total cardiovascular mortality or cardiovascular events (total myocardial infarction, unstable angina, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, total stroke). All included studies reported the effect of whole grain diets on risk factors for cardiovascular disease including blood lipids and blood pressure. All studies were in primary prevention populations and had an unclear or high risk of bias, and no studies had an intervention duration greater than 16 weeks. Overall, we found no difference between whole grain and control groups for total cholesterol (mean difference 0.07, 95% confidence interval -0.07 to 0.21; 6 studies (7 comparisons); 722 participants; low-quality evidence). Using GRADE, we assessed the overall quality of the available evidence on cholesterol as low. Four studies were funded by independent national and government funding bodies, while the remaining studies reported funding or partial funding by organisations with commercial interests in cereals. Authors' conclusions: There is insufficient evidence from RCTs of an effect of whole grain diets on cardiovascular outcomes or on major CVD risk factors such as blood lipids and blood pressure. Trials were at unclear or high risk of bias with small sample sizes and relatively short-term interventions, and the overall quality of the evidence was low. There is a need for well-designed, adequately powered RCTs with longer durations assessing cardiovascular events as well as cardiovascular risk factors

The 74MHz System on the Very Large Array

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and resolution (~25 arcsec) for low-frequency observations. We review the hardware, the calibration and imaging strategies, comparing them to those at higher frequencies, including aspects of interference excision and wide-field imaging. Ionospheric phase fluctuations pose the major difficulty in calibrating the array. Over restricted fields of view or at times of extremely quiescent ionospheric ``weather'', an angle-invariant calibration strategy can be used. In this approach a single phase correction is devised for each antenna, typically via self-calibration. Over larger fields of view or at times of more normal ionospheric ``weather'' when the ionospheric isoplanatic patch size is smaller than the field of view, we adopt a field-based strategy in which the phase correction depends upon location within the field of view. This second calibration strategy was implemented by modeling the ionosphere above the array using Zernike polynomials. Images of 3C sources of moderate strength are provided as examples of routine, angle-invariant calibration and imaging. Flux density measurements indicate that the 74 MHz flux scale at the VLA is stable to a few percent, and tied to the Baars et al. value of Cygnus A at the 5 percent level. We also present an example of a wide-field image, devoid of bright objects and containing hundreds of weaker sources, constructed from the field-based calibration. We close with a summary of lessons the 74 MHz system offers as a model for new and developing low-frequency telescopes. (Abridged)Comment: 73 pages, 46 jpeg figures, to appear in ApJ

The balance of power: accretion and feedback in stellar mass black holes

In this review we discuss the population of stellar-mass black holes in our galaxy and beyond, which are the extreme endpoints of massive star evolution. In particular we focus on how we can attempt to balance the available accretion energy with feedback to the environment via radiation, jets and winds, considering also possible contributions to the energy balance from black hole spin and advection. We review quantitatively the methods which are used to estimate these quantities, regardless of the details of the astrophysics close to the black hole. Once these methods have been outlined, we work through an outburst of a black hole X-ray binary system, estimating the flow of mass and energy through the different accretion rates and states. While we focus on feedback from stellar mass black holes in X-ray binary systems, we also consider the applicability of what we have learned to supermassive black holes in active galactic nuclei. As an important control sample we also review the coupling between accretion and feedback in neutron stars, and show that it is very similar to that observed in black holes, which strongly constrains how much of the astrophysics of feedback can be unique to black holes.Comment: To be published in Haardt et al. Astrophysical Black Holes. Lecture Notes in Physics. Springer 201