Planar Rayleigh scattering results in helium-air mixing experiments in a Mach-6 wind tunnel

Planar Rayleigh scattering measurements with an argon—fluoride excimer laser are performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach-6 facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross-sectional area (5 cm × 10 cm) of the flow field in the absence of clusters

Diagnostic strategies used in primary care

The strategies used by general practitioners in making a diagnosis are being formally recognised; this article is the first in a series that will illustrate their application, and is accompanied by a case study (doi:10.1136/bmj.b1187

Probing High Permeability of Nuclear Pore Complexes by Scanning Electrochemical Microscopy: Ca2+ Effects on Transport Barriers

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http:doi.org/10.1021/acs.analchem.9b00796.The nuclear pore complex (NPC) solely mediates molecular transport between the nucleus and cytoplasm of a eukaryotic cell to play important biological and biomedical roles. However, it is not well-understood chemically how this biological nanopore selectively and efficiently transports various substances, including small molecules, proteins, and RNAs by using transport barriers that are rich in highly disordered repeats of hydrophobic phenylalanine and glycine intermingled with charged amino acids. Herein, we employ scanning electrochemical microscopy to image and measure the high permeability of NPCs to small redox molecules. The effective medium theory demonstrates that the measured permeability is controlled by diffusional translocation of probe molecules through water-filled nanopores without steric or electrostatic hindrance from hydrophobic or charged regions of transport barriers, respectively. However, the permeability of NPCs is reduced by a low millimolar concentration of Ca2+, which can interact with anionic regions of transport barriers to alter their spatial distributions within the nanopore. We employ atomic force microscopy to confirm that transport barriers of NPCs are dominantly recessed (∼80%) or entangled (∼20%) at the high Ca2+ level in contrast to authentic populations of entangled (∼50%), recessed (∼25%), and “plugged” (∼25%) conformations at a physiological Ca2+ level of submicromolar. We propose a model for synchronized Ca2+ effects on the conformation and permeability of NPCs, where transport barriers are viscosified to lower permeability. Significantly, this result supports a hypothesis that the functional structure of transport barriers is maintained not only by their hydrophobic regions, but also by charged regions

A cultura do girassol.

Introdução. Exigências climáticas. Escolha de área. Correção da acidez. Preparo do solo. Preparo convencional.Semeadura direta. Controle de plantas daninhas. Controle mecânico de plantas daninhas. Herbicidas para o manejo de plantas daninhas na semeadura direta. Herbicidas registrados para a cultura do girassol. Resíduo de herbicidas na cultura do girassol. Adubação. Época de semeadura. Semeadura. Espaçamento e densidade. Doenças. Pragas. Colheita. Custo de produção e rentabilidade da cultura do girassol. Literatura consultada.bitstream/item/77468/1/CNPSO-CIR.-TEC.-13-96.pd

A cultura do girassol.

Exigencias climaticas; Escolha de area; Correcao da acidez; Preparo do solo; Controle de plantas daninhas; Adubacao; Epoca de semeadura; Espacamento e densidade; Doencas; Pragas; Colheita; Custo de producao e rentabilidade da cultura do girassol.bitstream/item/42696/1/ID-2434.pd

Twist-3 contribution to the γ∗γ→ππ\gamma^*\gamma\to \pi\pi amplitude in the Wandzura-Wilczek approximation

We have calculated the Wandzura-Wilczek contribution to the twist-3 part of $\gamma^*\gamma\to 2\pi$ amplitude. It describes interaction of the longitudinally polarized virtual photon with the real one, and it is suppressed by 1/Q, where $Q^2$ is the virtuality of the $\gamma^*$, as compared to the twist-2 contribution. We have found that, in the Wandzura-Wilczek approximation, factorization applies to the twist-3 amplitude.Comment: 13 pages, 4 figure

Modeling power corrections to the Bjorken sum rule for the neutrino structure function F_1

Direct measurements of the the structure functions F_1^{nu p} and F_1^{nu n} at a neutrino factory would allow for an accurate extraction of alpha_s from the Q^2-dependence of the Bjorken sum rule, complementing that based on the Gross-Llewellyn-Smith sum rule for F_3. We estimate the power (1/Q^2-) corrections to the Bjorken sum rule in the instanton vacuum model. For the reduced matrix element of the flavor-nonsinglet twist-4 operator ubar_g_Gdual_gamma_gamma5_u - (u -> d) we obtain a value of 0.18 GeV^2, in good agreement with the QCD sum rule calculations of Braun and Kolesnichenko. Our result allows to reduce the theoretical error in the determination of alpha_s.Comment: 3 pages, 1 figure, uses iopart.cls. Proceedings of the 4th NuFact'02 Workshop "Neutrino Factories based on Muon Storage Rings", Imperial College, London, July 1-6, 200

Azimuthal asymmetries at CLAS: Extraction of e^a(x) and prediction of A_{UL}

First information on the chirally odd twist-3 proton distribution function e(x) is extracted from the azimuthal asymmetry, A_{LU}, in the electro-production of pions from deeply inelastic scattering of longitudinally polarized electrons off unpolarized protons, which has been recently measured by CLAS collaboration. Furthermore parameter-free predictions are made for azimuthal asymmetries, A_{UL}, from scattering of an unpolarized beam on a polarized proton target for CLAS kinematics.Comment: 9 pages, 5 figures, late

Advanced airway training in the UK : A national survey of senior anesthetic trainees

Background and Aims: High-quality training in advanced airway skills is imperative to ensure safe anesthetic care and develop future airway specialists. Modern airway management skills are continually evolving in response to advancing technology and developing research. Therefore, it is of concern that training provisions and trainee competencies remain current and effective. Material and Methods: A survey questionnaire based on the airway competencies described in the Royal College of Anaesthetists’ curriculum and Difficult Airway Society guidelines was posted to all United Kingdom (UK) National Health Service hospitals to be completed by the most senior anesthetic trainee (ST 5–7, resident). Results: A total of 149 responses were analyzed from 237 hospitals with eligible anesthetic trainees (response rate 63%), including 53 (36%) and 39 (26%) respondents who had completed higher and advanced level airway training respectively. Although clinical experience with videolaryngoscopy was satisfactory, poor confidence and familiarity was identified with awake fiberoptic intubation, high frequency jet ventilation, at risk extubation techniques, and airway ultrasound assessment. Only 26 (17%) respondents had access to an airway skills room or had regular airway emergency training with multidisciplinary theater team participation. Reported barriers to training included lack of training lists, dedicated teaching time, experienced trainers, and availability of equipment. Conclusions: This national survey identified numerous deficiencies in airway competencies and training amongst senior anesthetic trainees (residents) in the UK. Restructuring of the airway training program and improvements in access to training facilities are essential to ensure effective airway training and the capability to produce future airway specialists