19,356 research outputs found

    Proforma-based reporting in rectal cancer

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    The improvements in outcomes associate with the use of preoperative therapy rather than postoperative treatment means that clinical teams are increasingly reliant on imaging to identify high-risk features of disease to determine treatment plans. For many solid tumours, including rectal cancer, validated techniques have emerged in identifying prognostic factors pre-operatively. In the MERCURY study, a standardised scanning technique and the use of reporting proformas enabled consistently accurate assessment and documentation of the prognostic factors. This is now an essential tool to enable our clinical colleagues to make treatment decisions. In this review, we describe the proforma-based reporting tool that enables a systematic approach to the interpretation of the magnetic resonance images, thereby enabling all the clinically relevant features to be adequately assessed. © 2009 International Cancer Imaging Society

    Joint evolution of multiple social traits: a kin selection analysis

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    General models of the evolution of cooperation, altruism and other social behaviours have focused almost entirely on single traits, whereas it is clear that social traits commonly interact. We develop a general kin-selection framework for the evolution of social behaviours in multiple dimensions. We show that whenever there are interactions among social traits new behaviours can emerge that are not predicted by one-dimensional analyses. For example, a prohibitively costly cooperative trait can ultimately be favoured owing to initial evolution in other (cheaper) social traits that in turn change the cost-benefit ratio of the original trait. To understand these behaviours, we use a two-dimensional stability criterion that can be viewed as an extension of Hamilton's rule. Our principal example is the social dilemma posed by, first, the construction and, second, the exploitation of a shared public good. We find that, contrary to the separate one-dimensional analyses, evolutionary feedback between the two traits can cause an increase in the equilibrium level of selfish exploitation with increasing relatedness, while both social (production plus exploitation) and asocial (neither) strategies can be locally stable. Our results demonstrate the importance of emergent stability properties of multidimensional social dilemmas, as one-dimensional stability in all component dimensions can conceal multidimensional instability

    Effectiveness of resistance training and associated program characteristics in patients at risk for type 2 diabetes:a systematic review and meta-analysis

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    BACKGROUND: Resistance training (RT) is an effective intervention for glycemic control and cardiometabolic health in individuals with type 2 diabetes (T2D). However, the use of RT in individuals at risk for T2D to prevent or delay the onset of T2D, and RT program characteristics that are most effective are still unknown. The purpose of this review is to determine the effects of RT on cardiometabolic risk factors in those at risk for T2D and to examine RT program characteristics associated with intervention effectiveness. METHODS: PubMed, Cochrane, Web of Science, and Embase databases were systematically searched for published controlled trials that compared cardiometabolic outcomes in adults with cardiometabolic risk for those that underwent an RT intervention with those that did not. A systematic review and meta-analysis was conducted to determine the effect of RT on glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), body fat percentage (BF%), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TG). Additional analyses examined effects of intervention duration and dietary intervention on FPG and TG. RESULTS: Fourteen trials with 668 participants were included. For RT compared to controls, the standardized mean difference (SMD) was −1.064 for HbA1c (95% confidence interval [CI] −1.802 to −0.327; p=0.005), −0.99 for FPG (95% CI −1.798 to −0.183; p=0.016), −0.933 for TC (95% CI −1.66 to −0.206; p=0.012), −0.840 for BF% (95% CI −1.429 to −0.251; p=0.005), −0.693 for HDL (95% CI −1.230 to −0.156; p=0.011), −1.03 for LDL (95% CI −2.03 to −0.050; p=0.039), and −0.705 for TG (95% CI −1.132 to −0.279; p=0.001). CONCLUSIONS: RT is beneficial for improving glycemic control, BF%, and blood lipids in those at risk for diabetes. The addition of a dietary component did not result in larger reductions in FPG and TG than RT alone. PROSPERO REGISTRATION ID: CRD42019122217 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40798-021-00321-x

    Mixed valency in cerium oxide crystallographic phases: Determination of valence of the different cerium sites by the bond valence method

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    We have applied the bond valence method to cerium oxides to determine the oxidation states of the Ce ion at the various site symmetries of the crystals. The crystals studied include cerium dioxide and the two sesquioxides along with some selected intermediate phases which are crystallographically well characterized. Our results indicate that cerium dioxide has a mixed-valence ground state with an f-electron population on the Ce site of 0.27 while both the A- and C-sesquioxides have a nearly pure f^1 configuration. The Ce sites in most of the intermediate oxides have non-integral valences. Furthermore, many of these valences are different from the values predicted from a naive consideration of the stoichiometric valence of the compound

    The Triple Pulsar System PSR B1620-26 in M4

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    The millisecond pulsar PSR B1620-26, in the globular cluster M4, has a white dwarf companion in a half-year orbit. Anomalously large variations in the pulsar's apparent spin-down rate have suggested the presence of a second companion in a much wider orbit. Using timing observations made on more than seven hundred days spanning eleven years, we confirm this anomalous timing behavior. We explicitly demonstrate, for the first time, that a timing model consisting of the sum of two non-interacting Keplerian orbits can account for the observed signal. Both circular and elliptical orbits are allowed, although highly eccentric orbits require improbable orbital geometries. The motion of the pulsar in the inner orbit is very nearly a Keplerian ellipse, but the tidal effects of the outer companion cause variations in the orbital elements. We have measured the change in the projected semi-major axis of the orbit, which is dominated by precession-driven changes in the orbital inclination. This measurement, along with limits on the rate of change of other orbital elements, can be used to significantly restrict the properties of the outer orbit. We find that the second companion most likely has a mass m~0.01 Msun --- it is almost certainly below the hydrogen burning limit (m<0.036 Msun, 95% confidence) --- and has a current distance from the binary of ~35 AU and orbital period of order one hundred years. Circular (and near-circular) orbits are allowed only if the pulsar magnetic field is ~3x10^9 G, an order of magnitude higher than a typical millisecond pulsar field strength. In this case, the companion has mass m~1.2x10^-3 Msun and orbital period ~62 years.Comment: 12 pages, 6 figures, 3 tables. Very minor clarifications and rewording. Accepted for publication in the Astrophys.

    Cosmological constraints from COMBO-17 using 3D weak lensing

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    We present the first application of the 3D cosmic shear method developed in Heavens et al. (2006) and the geometric shear-ratio analysis developed in Taylor et al. (2006), to the COMBO-17 data set. 3D cosmic shear has been used to analyse galaxies with redshift estimates from two random COMBO-17 fields covering 0.52 square degrees in total, providing a conditional constraint in the (sigma_8, Omega_m) plane as well as a conditional constraint on the equation of state of dark energy, parameterised by a constant w= p/rho c^2. The (sigma_8, Omega_m) plane analysis constrained the relation between sigma_8 and Omega_m to be sigma_8(Omega_m/0.3)^{0.57 +- 0.19}=1.06 +0.17 -0.16, in agreement with a 2D cosmic shear analysis of COMBO-17. The 3D cosmic shear conditional constraint on w using the two random fields is w=-1.27 +0.64 -0.70. The geometric shear-ratio analysis has been applied to the A901/2 field, which contains three small galaxy clusters. Combining the analysis from the A901/2 field, using the geometric shear-ratio analysis, and the two random fields, using 3D cosmic shear, w is conditionally constrained to w=-1.08 +0.63 -0.58. The errors presented in this paper are shown to agree with Fisher matrix predictions made in Heavens et al. (2006) and Taylor et al. (2006). When these methods are applied to large datasets, as expected soon from surveys such as Pan-STARRS and VST-KIDS, the dark energy equation of state could be constrained to an unprecedented degree of accuracy.Comment: 10 pages, 4 figures. Accepted to MNRA

    The Magnetic Field of the H~II Region NGC 6334A

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    We have studied the polarization characteristics and Faraday rotation of the extragalactic radio source J17204−-3554, that appears projected on the north lobe of the galactic H II region NGC 6334A. From observations made with the Very Large Array at 6.0 and 3.6 cm in three different epochs (1994, 1997, and 2006), we estimate a rotation measure of +5100±\pm900 rad m−2^{-2} for the extragalactic source. This large rotation measure implies a line-of-sight average magnetic field of B∄≃+36±6B_\parallel \simeq +36\pm6 ÎŒ\muG, the largest obtained by this method for an H II region. NGC 6334A is significantly denser than other H II regions studied and this larger magnetic field is expected on the grounds of magnetic flux conservation. The ratio of thermal to magnetic pressure is ∌\sim5, in the range of values determined for more diffuse H II regions.Comment: 5 pages, 0 figure
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