Cosmological Model Predictions for Weak Lensing: Linear and Nonlinear Regimes

Weak lensing by large scale structure induces correlated ellipticities in the images of distant galaxies. The two-point correlation is determined by the matter power spectrum along the line of sight. We use the fully nonlinear evolution of the power spectrum to compute the predicted ellipticity correlation. We present results for different measures of the second moment for angular scales \theta \simeq 1'-3 degrees and for alternative normalizations of the power spectrum, in order to explore the best strategy for constraining the cosmological parameters. Normalizing to observed cluster abundance the rms amplitude of ellipticity within a 15' radius is \simeq 0.01 z_s^{0.6}, almost independent of the cosmological model, with z_s being the median redshift of background galaxies. Nonlinear effects in the evolution of the power spectrum significantly enhance the ellipticity for \theta < 10' -- on 1' the rms ellipticity is \simeq 0.05, which is nearly twice the linear prediction. This enhancement means that the signal to noise for the ellipticity is only weakly increasing with angle for 2'< \theta < 2 degrees, unlike the expectation from linear theory that it is strongly peaked on degree scales. The scaling with cosmological parameters also changes due to nonlinear effects. By measuring the correlations on small (nonlinear) and large (linear) angular scales, different cosmological parameters can be independently constrained to obtain a model independent estimate of both power spectrum amplitude and matter density \Omega_m. Nonlinear effects also modify the probability distribution of the ellipticity. Using second order perturbation theory we find that over most of the range of interest there are significant deviations from a normal distribution.Comment: 38 pages, 11 figures included. Extended discussion of observational prospects, matches accepted version to appear in Ap

Nutritional Characteristics of Four Species of Native Pastures from the Highlands of Central Mexico

Research in Mexico has been devoted to nutritional characterisation of improved pastures, but native species of grasses have not been studied. The aim of this experiment was to evaluate the nutritional value of four species of native pastures and composite samples of them

Blended teaching and learning methods in nursing and midwifery education: A scoping review of the literature

Background: Blended learning (BL) is defined as the combination of both traditional face-to-face learning and synchronous or asynchronous e-learning approaches. The aim of this scoping review was to explore the literature to obtain a broad understanding of the use of BLin nursing and midwifery education in general, in Sub-Saharan Africa (SSA), and in particular Rwanda.Methods: The literature published between 2010 and 2019 were reviewed from six electronic databases using keywords including blended learning, nursing education, midwifery education, higher education, SSA, and Rwanda. Arksey and O'Malley's framework was used in this review.Results: The initial search identified 1,283 records. Eleven articles were selected for this review after the application of predetermined inclusion criteria. Almost all reviewed articles indicated that the integration of BLmethods improved the quality of nursing and midwifery education in general, and in SSAcountries including Rwanda.Conclusions: Initial research in this area highlights that moving from traditional classroom-delivered programs to the BLapproach is feasible and can promote the quality of nursing and midwifery standards of education. This scoping review highlights a paucity of research on BL in nursing and midwifery education, particularly in SSAcountries. Keywords: Blended learning, nursing and midwifery education, SSA, Rwand

Experimental assessment of a numerical modelling code developed for the profile extrusion cooling stage

One of the critical stages in the extrusion of thermoplastic profiles is the cooling of the profile, which is usually undertaken in a metallic calibrator. In order to assure the highest possible productivity, the profile thermal energy must be removed as fast as possible. However, due to the typical low diffusivity of thermoplastic materials, the cooling stage is relatively long and the temperature gradients along the profile thickness are high, promoting the development of thermal residual stresses, which should be minimized. Consequently, designing an optimum calibration system that ensures fast and low level of thermal residual stresses is always a difficult task, especially when dealing with complex geometry profiles. In this work, we firstly report the experimental assessment of a previously developed numerical modelling code [1], which is able to model the thermal interchanges that take place at the profile extrusion calibration stage, and was developed in the framework of the OpenFOAM® [2] computational library. This task is undertaken with an industrial case study: a cooling system, composed by three calibrators in series, used in the production of a swimming pool cover profile. The experimental data of the temperature evolution along the calibration length was found to be similar to the numerical predictions, with a maximum relative error of circa 8.6% near the inlet of the second calibrator unit, which allowed the numerical code validation. Upon the experimental assessment the numerical code was used to support the redesign of the calibration system. This study led to an alternative calibration system design, which has a simpler constructive solution and a better performance than the original one, considered in the validation of the numerical code. As main conclusions, the results reported in this work prove the accuracy of the numerical code developed to compute the temperature distribution in the cooling/calibration extrusion stage, and its suitability to support the design of these systems.This work is funded by UID/CTM/50025/2013 - LA0025, with the financial support of FCT/MEC through national funds and when applicable by FEDER co-funded, within the partnership agreement PT2020

The observed infall of galaxies towards the Virgo cluster

We examine the velocity field of galaxies around the Virgo cluster induced by its overdensity. A sample of 1792 galaxies with distances from the Tip of the Red Giant Branch, the Cepheid luminosity, the SNIa luminosity, the surface brightness fluctuation method, and the Tully-Fisher relation has been used to study the velocity-distance relation in the Virgocentric coordinates. Attention was paid to some observational biases affected the Hubble flow around Virgo. We estimate the radius of the zero-velocity surface for the Virgo cluster to be within (5.0 - 7.5) Mpc corresponding to (17 - 26)^\circ at the mean cluster distance of 17.0 Mpc. In the case of spherical symmetry with cosmological parameter \Omega_m=0.24 and the age of the Universe T_0= 13.7 Gyr, it yields the total mass of the Virgo cluster to be within M_T=(2.7 - 8.9) * 10^{14} M_\sun in reasonable agreement with the existing virial mass estimates for the cluster.Comment: 22 pages, 11 figures, 2 tables. Accepted for publication in MNRA

The rise of rapid implementation: a worked example of solving an existing problem with a new method by combining concept analysis with a systematic integrative review

Background The concept of rapid implementation has emerged in the literature recently, but without a precise definition. Further exploration is required to distinguish the concept’s unique meanings and significance from the perspective of implementation science. The study clarifies the concept of rapid implementation and identifies its attributes, antecedents, and consequences. We present a theoretical definition of rapid implementation to clarify its unique meaning and characteristics. Methods Rodgers evolutionary concept analysis method, combined with a systematic integrative review, were used to clarify the concept of rapid implementation. A comprehensive search of four databases, including EMBASE, MEDLINE, SCOPUS, and WEB OF SCIENCE was conducted, as well as relevant journals and reference lists of retrieved studies. After searching databases, 2442 papers were identified from 1963 to 2019; 24 articles were found to fit the inclusion criteria to capture data on rapid implementation from across healthcare settings in four countries. Data analysis was carried out using descriptive thematic analysis. Results The results locate the introduction of rapid implementation, informed by implementation science. Guidance for further conceptualisation to bridge the gap between research and practice and redefine rigour, adapting methods used (current approaches, procedures and frameworks), and challenging clinical trial design (efficacy-effectiveness-implementation pipeline) is provided. Conclusions It is possible that we are on the cusp of a paradigm shift within implementation brought about by the need for faster results into practice and policy. Researchers can benefit from a deeper understanding of the rapid implementation concept to guide future implementation of rapid actionable results in clinical practice

Optical and Radio Observations of the Afterglow from GRB990510: Evidence for a Jet

We present multi-color optical and two-frequency radio observations of the bright SAX event, GRB 990510. The well-sampled optical decay, together with the radio observations are inconsistent with simple spherical afterglow models. The achromatic optical steepening and the decay of the radio afterglow both occuring at $t \sim 1$ day are evidence for hydrodynamical evolution of the source, and can be most easily interpreted by models where the GRB ejecta are collimated in a jet. Employing a simple jet model to interpret the observations, we derive a jet opening angle of $\theta_o = 0.08$, reducing the isotropic gamma-ray emission of $2.9 \times 10^{53}$ erg by a factor $\sim 300$. If the jet interpretation is correct, we conclude that GRB observations to-date are consistent with an energy for the central source of E \lsim 10^{52} erg.Comment: 12 pages, 2 figures. Version accepted for publication in ApJ Letter