Using the literature to quantify the learning curve: a case study

Objective: To assess whether a literature review of a technology can allow a learning curve to be quantified. Methods: The literature for fibreoptic intubation was searched for studies reporting information relevant to the learning curve. The Cochrane Librar y, Medline, Embase and Science Citation index were searched. Studies that reported a procedure time were included. Data were abstracted on the three features of learning: initial level, rate of learning and asymptote level. Random effect meta-analysis was performed. Results: Only 21 studies gave explicit information concerning the previous experience of the operator(s). There were 32 different definitions of procedure time. From 4 studies of fibreoptic nasotracheal intubation, the mean starting level and time for the 10th procedure (95% confidence interval) was estimated to be 133s (113, 153) and 71s (62, 79) respectively. Conclusions: The review approach allowed learning to be quantified for our example technology. Poor and insufficient reporting constrained formal statistical estimation. Standardised reporting of non-drug techniques with adequate learning curve details is needed to inform trial design and costeffectiveness analysis

Nutrition Labeling in the United States and the Role of Consumer Processing, Message Structure, and Moderating Conditions

It has been since 1990 that the landmark Nutritional Labeling Education Act (NLEA) was passed in the United States, and since 1969 that the first White House Conference on Food, Nutrition and Health occurred. In the time since these important events, considerable research has been conducted on how U.S. consumers process and use nutritional labeling. An up-to-date review of nutritional labeling research must address key findings on the processing and use of nutrition facts panels (NFPs), restaurant labeling, front-of-pack (FOP) symbols, health and nutrient content claims, new labeling efforts (e.g., for meat products), and claims not regulated by the U.S. Food and Drug Administration (FDA). Message structure mediates the ways in which consumers process nutritional labeling while moderating conditions affect research outcomes associated with labeling efforts. The most recent policy issues and problems to be considered (e.g., by the FDA) include nutritional labeling as well as identifying opportunities for consumer research in helping to promote healthy lifestyles and reducing obesity in the United States and throughout the world. For example, several unanswered research questions remain regarding how the proposed changes to the NFPs—beef, poultry, and seafood labeling; restaurant chain calorie labeling; alternative FOP formats; and regulated and unregulated health and nutrient content claims—will affect consumers. Researchers have yet to examine not only these different labeling and nutrition information formats, but also how they might interact with one another and the role of key moderating conditions (e.g., one’s motivation, ability opportunity to process nutrition information) in affecting consumer processing and behavior

Prototyping of the ILC Baseline Positron Target

The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic field over the 1 ms ILC pulse train. We report on prototyping effort on this system.Comment: 7 pages, 9 figures, Proceedings of the International Workshop on Future Linear Colliders, Granada Spain, 26-30 September 201

The Black Body in Donald Pierson’s Thesis “Negroes in Brazil”

Este artigo tem como objetivo apresentar a abordagem do corpo negro na tese de doutorado de Donald Pierson (1900-1995). A questão a ser investigada é: como um dos primeiros estudos sobre questões raciais realizados no Brasil trata o corpo negro? O referencial teórico foi definido por autores das Ciências Sociais. A tese foi considerada como um documento histórico. Uma análise de conteúdo foi feita com base nos seguintes aspectos: estrutura física do trabalho, notas da segunda e da primeira introdução e abordagens sobre o corpo. Os resultados sugerem que o corpo negro não se revela exatamente como objeto de estudo, mas se trata de um elemento que está relacionado a aspectos biológicos e do movimento dos corpos negros. Conclui-se que retomar a investigação iniciada por Pierson sobre negros na Bahia é relevante por possibilitar o entendimento de marcadores do corpo negro no contexto brasileiro.This article aims to present the way the black body is approached in Donald Pierson’s (1900-1995) doctoral thesis. The question to be investigated is: how does one of the first studies on racial issues carried out in Brazil treat the black body? The theoretical framework was defined by authors from the social sciences. The thesis was considered as a historical document. A content analysis was made based on the following codes: the work’s physical structure, notes on the second and the first introductions, and approaches about the body. The results suggest that the black body did not properly qualify as an object of study, but it reveals an element that identifies both biological aspects and the movement of black bodies. It is concluded that resuming the investigation initiated by Pierson about blacks in Bahia is relevant because it allows the understanding of black body markers in the Brazilian context

A questionnaire elicitation of surgeons' belief about learning within a surgical trial

PMID: 23145113 [PubMed - indexed for MEDLINE] PMCID: PMC3493499 Free PMC ArticlePeer reviewedPublisher PD

Patellar tendinopathy: pathomechanics and a modern approach to treatment

Patellar tendinopathy, a common condition in sport, can be recurrent and resistant to treatment, Risk factors include the level of training, biomechanics, and genetic factors. This review discusses several programs based on eccentric exercise and suggests principles for nonoperative treatment including improving shock absorption, load modification, and adaptation of the tendon to sporting stress. The level of pain that patients are asked to tolerate during tendon-exercise programs varies among programs, and it is unclear what level is optimal to stimulate tendon recovery. Rehabilitation presents several challenges: It can take a long time (3-12 months), exercise prescription in an athlete who is continuing to compete is not straightforward, and guidelines for treatment progression are poor, Nonoperative treatment can fail because of inappropriate exercise prescription and poor athlete compliance. If this occurs and surgical intervention is required, the athlete might still have an unpredictable outcome. Solutions to these problems require additional clinical research.<br /

Petrogenesis and evolution of alkalic basaltic magmas in a continental intraplate setting: the South Auckland Volcanic Field, New Zealand

The South Auckland volcanic field (SAVF) is situated in a continental intraplate tectonic setting and consists of silica-undersaturated alkalic basalts that erupted from about 100 centres between 1.59 and 0.51 Ma. The basalts range in composition from basanites to quartz tholeiites. Two basalt groups are distinguished based on their contrasting mineralogical and geochemical characteristics: group A, a less silica-undersaturated transitional basalt to quartz tholeiite suite; and group B, a strongly silica-undersaturated basanite to nepheline hawaiite suite. The petrogenesis and evolution of the SAVF basalts is examined using new data from 200 samples on mineral chemistry from electron microprobe analyses, major and trace elements from XRF, incompatible trace elements and REE from ICP-MS, and Sr, Nd, and Pb isotopic data from TIMS analyses. Forsteritic olivine is the dominant phenocryst phase in each rock group (group A: Fo₆₁ - Fo₈₂; group B: Fo₆₄ - Fo₉₂). Clinopyroxene is abundant and ranges from augite (Wo₃₅₋₄₇ En₃₆₋₅₀ Fs₁₁₋₂₃) in group A to diopside (Wo₄₂₋₅₂ En₃₂₋₄₆ Fs₁₀₋₂₀) in group B basalts. Plagioclase (An₄₀₋₇₀) is found as a phenocryst only in group A basalts. The group A basalts are distinguished by their low total alkalis (3.0 - 4.8 wt.%), Nb (9 - 29 ppm) and Zr (97 - 210 ppm) abundances, and low (La/Yb)N (3.4- 7.6), which contrast with group B that have large total alkalis (3.3 - 7.9 wt.%), Nb (35 - 102 ppm) and Zr (194 - 491 ppm), and (La/Yb)N (12 - 47). The incompatible trace elements of group A lavas have characteristics indicating derivation from an enriched upper mantle source but relatively depleted in Th, K, Nb, Ta, and LREE with small LREE/HREE values, whereas those in group B exhibit strong trace element affinities (i.e., large Th, Nb, Ta, and LREE abundances) with an OIB-like source. Petrogenetic modelling suggests that the group A and B lavas evolved as discrete lineages that do not appear to be related to a common parental magma or source. Partial melting models indicate that < 8 % melting of a garnet-peridotite source is required to produce primary group B magmas, whereas primary group A magmas are generated from < 11 % melting of a spinel-peridotite source. Differentiation of basalts from each group is dominated by olivine and clinopyroxene fractionation, and only minor plagioclase in group A. Both rock groups fall within a narrow range of Sr and Nd isotopic compositions (⁸⁷Sr/⁸⁶Sr= 0.70273±19 - 0.70330±17 and εNd = + 5.97 to + 6.89) similar to the composition of HIMU-OIB, whereas Pb isotopic compositions are unradiogenic relative to HIMU-OIB (i.e., ²⁰⁶Pb/²⁰⁴Pb = 18.95 - 19.33; ²⁰⁷Pb/²⁰⁴Pb = 15.586 - 15.589; ²⁰⁸Pb/²⁰⁴Pb = 38.731 -38.906) and range between Atlantic MORB and EMII. The group A lavas have slightly higher ⁸⁷Sr/⁸⁶Sr and ²⁰⁷Pb/²⁰⁴Pb, lower ²⁰⁶Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb, and similar εNd values compared to those in group B, but there is no isotopic or geochemical evidence to suggest that any of the lavas have been contaminated by continental crust. Therefore, the relatively small but distinct differences in Sr and Pb isotopic compositions and similar εNd values are considered to be source-related. Variations in incompatible element ratios such as K/Nb and Zr/Nb indicate that the SA VF basalts were derived from two distinct sources. Group B basalts show incompatible trace element signatures characteristic of a LREE-enriched HIMU-OIB-like source, which can be accounted for by recycling of subducted oceanic crust at mantle depths. In contrast, the group A basalts have incompatible trace element affinities that are intermediate between a HIMU and an EMII-type component that could have resulted from subduction-related metasomatism of the subcontinental lithosphere modified by a HIMU plume. These events may have been connected with the subduction of the Phoenix plate and plume-related magmatism when New Zealand was at the eastern margin of the Gondwanaland supercontinent

EVALUATION OF PATELLAR TENDON MECHANICAL PROPERTIES AND THE PREFERRED LANDING LEG IN ELITE JUMPING ATHELTES

INTRODUCTION: The purpose of this investigation was to evaluate patellar tendon (PT) mechanical properties in healthy, elite jumping athletes and the association with their preferred landing leg

Detector and Telescope Development for ProtoEXIST and Fine Beam Measurements of Spectral Response of CZT Detectors

We outline our plan to develop ProtoEXIST, a balloon-borne prototype experiment for the Energetic X-ray Imaging Survey Telescope (EXIST) for the Black Hole Finder Probe. EXIST will consist of multiple wide-field hard X-ray coded-aperture telescopes. The current design of the EXIST mission employs two types of telescope systems: high energy telescopes (HETs) using CZT detectors, and low energy telescopes (LETs) using Si detectors. With ProtoEXIST, we will develop and demonstrate the technologies required for the EXIST HETs. As part of our development efforts, we also present recent laboratory measurements of the spectral response and efficiency variation of imaging CZT detectors on a fine scale (~0.5 mm). The preliminary results confirm the need for multi-pixel readouts and small inter-pixel gaps to achieve uniform spectral response and high detection efficiency across detectors.Comment: 9 pages, 12 figures, 1 table, appears in SPIE 2005 proceedings (5898: UV, X-ray, and Gamma-ray Space Instrumentation for Astronomy XIV

Regression discontinuity designs in health: a systematic review

Background: Regression discontinuity designs are non-randomized study designs that permit strong causal inference with relatively weak assumptions. Interest in these designs is growing but there is limited knowledge of the extent of their application in health. We aimed to conduct a comprehensive systematic review of the use of regression discontinuity designs in health research. Methods: We included studies that used regression discontinuity designs to investigate the physical or mental health outcomes of any interventions or exposures in any populations. We searched 32 health, social science, and grey literature databases (1 January 1960-1 January 2019). We critically appraised studies using eight criteria adapted from the What Works Clearinghouse Standards for regression discontinuity designs. We conducted a narrative synthesis, analyzing the forcing variables and threshold rules used in each study. Results: The literature search retrieved 7658 records, producing 325 studies that met the inclusion criteria. A broad range of health topics were represented. The forcing variables used to implement the design were age; socioeconomic measures; date or time of exposure or implementation; environmental measures such as air quality; geographic location; and clinical measures that act as a threshold for treatment. Twelve percent of the studies fully met the eight quality appraisal criteria. Fifteen percent of studies reported a pre-specified primary outcome or study protocol. Conclusions: This systematic review demonstrates that regression discontinuity designs have been widely applied in health research and could be used more widely still. Shortcomings in study quality and reporting suggest that the potential benefits of this method have not yet been fully realized