Proterozoic Bushveld-Vredefort catastrophe: Possible causes and consequences

Bushveld Complex and Vredefort Dome are unique features, formed in close proximity during the same time interval, approximately 2 Ga. Both show evidence of catastrophic events in the shallow marine environment of the otherwise stable Kaapvaal Craton. Explanation by multiple impacts of an asteroid, brecciated by an inter-asteroidal collision and disintegrating in Earth's gravity field is supported by pseudotachylite, shatter cones, coesite, and stishovite at Vredefort but these shock phenomena were not found in the Bushveld Complex. The Bushveld Complex was formerly interpreted as a lopolith, a view incompatible with gravity, electrical resistivity, magnetic, and seismic-reflection data. It is outlined by five inward-dipping lobes of layered ultramafic-mafic plutonic rocks that partly coalesce to form a basin-like feature 400 km in diameter and 65,000 sq. km. in area, equivalent to a small lunar mare. The Bushveld Complex is orders of magnitudes larger than other proposed terrestrial impact structures and differs from them in important ways. Its principal members, in order of age, are Rooiberg Felsite, RLS, and Lebowa Granite. The Bushveld-Vredefort events occurred during the interval from neutral or reducing atmosphere to oxidizing atmosphere. This transition is usually related to the evolution of photosynthesizing organisms. If the impact hypothesis for Bushveld-Vredefort can be confirmed, it may represent a global catastrophe sufficient to contribute to environmental changes favoring aerobic photosynthesizing eukaryotes over anaerobic prokaryotes

Reducing weight and increasing physical activity in people at high risk of cardiovascular disease: a randomised controlled trial comparing the effectiveness of enhanced motivational interviewing intervention with usual care.

OBJECTIVE: The epidemic of obesity is contributing to the increasing prevalence of people at high risk of cardiovascular disease (CVD), negating the medical advances in reducing CVD mortality. We compared the clinical and cost-effectiveness of an intensive lifestyle intervention consisting of enhanced motivational interviewing in reducing weight and increasing physical activity for patients at high risk of CVD. METHODS: A three-arm, single-blind, parallel-group randomised controlled trial was conducted in consenting primary care centres in south London. We recruited patients aged 40-74 years with a QRisk2 score ≥20.0%, which indicates the probability of having a CVD event in the next 10 years. The intervention was enhanced motivational interviewing which included additional behaviour change techniques and was delivered by health trainers in 10 sessions over 1 year, in either group (n=697) or individual (n=523) format. The third arm received usual care (UC; n=522). The primary outcomes were physical activity (mean steps/day) and weight (kg). Secondary outcomes were changes in low-density lipoprotein cholesterol and CVD risk score. We estimated the relative cost-effectiveness of each intervention. RESULTS: At 24 months, the group and individual interventions were not more effective than UC in increasing physical activity (mean difference=70.05 steps, 95% CI -288.00 to 147.90 and mean difference=7.24 steps, 95% CI -224.01 to 238.50, respectively), reducing weight (mean difference=-0.03 kg, 95% CI -0.49 to 0.44 and mean difference=-0.42 kg, 95% CI -0.93 to 0.09, respectively) or improving any secondary outcomes. The group and individual interventions were not cost-effective at conventional thresholds. CONCLUSIONS: Enhancing motivational interviewing with additional behaviour change techniques was not effective in reducing weight or increasing physical activity in those at high CVD risk

Dilemmas and Challenges in the Marketing of Hybrid Organizations: A Theoretical Exploration of Dutch Sheltered Work Companies

__Abstract__ This article explores the dilemmas and challenges that hybrid organizations face when developing marketi

Public Managers, Media Influence, and Governance: Three Research Traditions Empirically Explored

Nowadays, media and media logic have become important and inherent elements in everyday practices of public administration and policy making. However, the logic of the media is often very different from, and conflicting with, the logic of political and administrative life. So the question of how public managers experience and deal with media attention is more relevant than ever. An analytical sketch of the literature on the relationship between public managers and media provides three main categories of literature (public relations, agenda, and mediatization tradition). These three categories are used to develop statements (so-called Q-sort statements) to capture the way public managers experience thei

A three-season comparison of match performances among selected and unselected elite youth rugby league players

This is an author's accepted manuscript of an article published in Journal of Sports Sciences, 28 February 2014, available online: http:www.tandfonline.com/10.1080/02640414.2014.889838This study compared technical actions, movements, heart rates and perceptual responses of selected and unselected youth rugby league players during matches (under-15 to under-17). The players’ movements and heart rates were assessed using 5 Hz Global Positioning Systems (GPS), while their technical actions were analysed using video analysis. The maturity of each player was predicted before each season for statistical control. There were no differences (P > 0.05) between selected and unselected players in the under-15 or the under-17 age groups for any variables. However, in the under-16 group, the selected players (57.1 ± 11.9 min) played for longer than the unselected players (44.1 ± 12.3 min; P = 0.017; ES = 1.08 ± CI = 0.87), and covered more distance (5,181.0 ± 1063.5 m cf. 3942.6 ± 1,108.6m, respectively; P = 0.012; ES = 1.14 ± CI = 0.88) and high intensity distance (1,808.8 ± 369.3 m cf. 1,380.5 ± 367.7 m, respectively; P = 0.011; ES = 1.16 ± CI = 0.88). Although successful carries per minute was higher in the selected under-15 group, there were no other differences (P > 0.05) in match performance relative to playing minutes between groups. Controlling for maturity, the less mature, unselected players from the under-16 group performed more high-intensity running (P < 0.05). Our findings question the use of match- related measurements in differentiating between selected and unselected players, showing that later maturing players were unselected, even when performing greater high-intensity running during matches

Introduction to Dry Gas Seals and Systems

TutorialDry gas seals are used as low-leakage shaft end seals for many centrifugal compressors and other turbomachines. This short course provides a comprehensive overview of sealing system and dry gas seals in various turbomachinery applications, addressing multiple topics ranging from fundamentals to detailed design considerations for reliable operation. A course attendee can expect a greater understanding of technologies, failure modes, and requirements for components in dry gas seals and seal supply/vent systems, with perspectives from an end user, a seal manufacturer, and a research organization.This short course will give listeners a thorough understanding of dry gas seals, including design, operation, and maintenance. Starting with the background of how dry gas seals were developed as a response to issues with wet seals, the course will then move into a detailed discussion on seal design. The instructors will explain how each component of the seal contributes to its operation and issues that can arise if parts are selected incorrectly. Next, seal selection for various applications (pipeline, process, advanced applications) will be discussed. Methods for seal testing to ensure that design conditions are met will be described, including test rigs studying off-design conditions, such as transients or contaminant injection.The gas conditioning process can be critical to successful seal operation, so seal gas panels and their components will be discussed in great detail. Operation during transients can be particularly challenging, so panel considerations specific to transient operation will be discussed. The recently-released API 692 will be discussed as it pertains to dry gas seal panel design, seal requirements, and seal testing.Understanding common failure modes is an important step to improving dry gas seal reliability. Recent research on dry gas seal failures will be presented, including failure statistics and failure modes. Insight on failure modes specific to heat generation from liquid contamination will be discussed, and recommendations will be provided to reduce failures.Copyright© 2020 by Turbomachinery Laboratory, Texas A&M Engineering Experiment StationThis short course is aimed primarily at end users, but the multifaceted approach (end user, OEM, research) will provide a valuable perspective on dry gas seals to anyone in the rotating equipment industry. By the end of the course, attendees will have a detailed understanding of dry gas seals and their associated systems

"I code as much as I can because you never know what they might ask for”. The role of the coach in Performance Analysis: The view of the analyst

Performance Analysis (PA) is viewed as an integral feature of soccer; however, the processes underpinning such practice are often described as simple, linear procedures. This fails to acknowledge the dynamism of PA and given increased investment and employment of analysts in professional soccer, scrutiny of the current processes and duties associated with the role would seem timely. To this purpose, eight full-time analysts in the English Football League (EFL) and English National League (National League) participated in in-depth semi-structured interviews and transcripts were subjected to inductive reflective thematic analysis. The data analysis revealed two higher-order categories (Flying solo / Coach control) and four themes classified as lower-order (PA pragmatism / Identifying indicators / The reticent coach / Autocratic presentations). The findings of this study highlight that the responsibilities of the performance analyst range from acting on their own initiative to responding to requests and instructions from the coach. Subsequently, the responsibility for individual actions/activities related to PA is dependent on what aspects of analysis are to be used, who is the recipient of the data/video/presentation, when in the relationship between analyst and coach the activities are developed and when in the match-play process they are carried out

Are you lookin’ at me? A mixed-methods case study to investigate the influence of coaches’ presence on performance testing outcomes in male academy rugby league players

The study used a mixed-methods approach to examine how the presence of coaches influenced male academy rugby league players’ performance during physical performance testing. Fifteen male rugby players completed two trials of 20 m sprint, countermovement jump and prone Yo-Yo test; one with only the sport scientist present and a second where the sport scientist conducted the battery with both the club's lead strength and conditioning coach, academy manager, and the first team assistant and head coach present. Players and coaches then completed one-to-one semi-structured interviews to explore their beliefs, attitudes and opinions towards physical performance testing. In all tests, the players’ performance was better when the coaches were present compared to when tests were conducted by the sport scientist alone. Interviews revealed performance testing was used by coaches to exercise their power over players to socialise them into the desired culture. Players’ own power was evident through additional effort during testing when coaches were present. Practitioners should ensure consistency in the presence of significant observers during performance testing of male rugby players to minimise their influence on test outcome

New diagnostic and treatment strategies in renal artery stenosis: a promising pursuit or disappointment foretold?

Clinical management of renal artery stenosis has seen a major shift, after randomised clinical trials have shown no group benefit of endovascular intervention relative to optimal medical control. However, the inclusion criteria of these trials have been criticised for focusing on a subset of patients with atherosclerotic renal artery stenosis where intervention was unlikely to be beneficial. Moreover, new imaging and computational techniques have become available, which have the potential to improve identification of patients that will respond to interventional treatment. This review addresses the challenges associated with clinical decision making in patients with renal artery stenosis. Opportunities for novel diagnostic techniques to improve patient selection are discussed, along with ongoing Dutch studies and network initiatives that investigate these strategies