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The synthesis of the Aquatic Biodiversity and Ecosystems Conference (ABEC) 2015, which was held to assess scientific progress over the past twnety-five years, this book provides a comprehensive and global review of work since the 1992 publication of Plant-Animal Interactions in the Marine Benthos. Taking a regional and, where appropriate, habitat perspective, it considers sites of coastal biodiversity from around the world to incorporate a global approach. The volume analyses abiotic and biotic interactions, and the factors determining distribution patterns, community structure and ecosystem functioning of coastal systems. It explores themes of how phylogeography and biogeographic process influence assemblage composition, and hence drive community structure and the respective roles of environmental factors and biological interactions, with the overall goal to establish how general are the processes in different regions and habitats. For researchers, graduate students and academics studying coastal ecosystems, with interest for conservation practitioners managing areas of high biodiversity.
At the end of the 2015 Aquatic Biodiversity and Ecosystems Conference, a day was set aside for a workshop following up on the 1990 Plant–Animal Interactions meeting and its associated Systematics Association book – Plant–Animal Interactions in the Marine Benthos (John et al., 1992). Talks given throughout the 2015 conference also informed the present volume and its chapters. The 2015 workshop took a comparative approach with a series of informal presentations and discussion sessions from selected participants from around the world. The general aim was to take a regionally based view of the role of interactions in setting distribution patterns, community structure and functioning of shallow-water marine ecosystems. The coverage was predominantly coastal, down to the limit of light penetration. Most contributions were from those working on rocky intertidal and subtidal habitats, reflecting the size (and willingness to contribute) of the research community coupled with the greater tradition of experimental approaches to examine interactions on more tractable hard substrata. In addition, mangroves, biofilms and the deep sea were also considered as special systems that are ubiquitous across several oceans where significant advances have been made and, therefore, warranted inclusion. Recent advances in remotely operated vehicles, for example, have increased the scope for observation and experiment in the deep sea (Johnson et al., 2013); whereas mangroves are important ecosystem engineers which provide important ecosystem services, but are declining globally (Polidoro et al., 2010; Chee et al., 2017). Biofilms were also included as a subject given their global distribution and importance as the site of first settlement of macrobenthic organisms and as a food source for grazers (Abreu et al., 2007). While this volume does not feature any chapters specifically on artificial structures, ocean sprawl or eco-engineering, a large number of talks and posters at the conference dealt with these emerging issues, reflecting their global importance (see Firth et al., 2016; Bishop et al., 2017 and Strain et al., 2018 for reviews). A notable omission is coral reefs, which were not covered because they already have a well-established community of research workers and deserve a volume in their own right. Inevitably, there are gaps in coverage reflecting difficulties in soliciting and delivering input, especially on soft shores as well as certain geographic locations. Coverage in 1992 and 2018 is shown on the maps in Figure 1.1.
This volume has achieved a large coverage of the experimentally well-studied areas of the temperate and subtropical coasts of the world (see Figure 1.1) – venturing into the tropics in some regions (Chapter 14, South-East Asia) and including mangroves (Chapter 17). Coral reef systems have not been considered. Much of the emphasis has been on rocky habitats as this is where the majority of experimental work on interactions has been done (but see Chapter 6). As well as reviewing regions where there has been a long history of experimental research (e.g., Chapters 2–4, 6, 10, 11, 13, 15, 16), areas of emerging experimental research in the last twenty-five years (e.g., Chapter 8, western Mediterranean; Chapter 12, south-east Pacific) and understudied regions (e.g., Chapter 7, Argentina; Chapter 14, South-East Asia) have also been included, allowing more comprehensive insights into the processes important for shaping these communities. In this short synthesis chapter, we first consider the main processes determining patterns covered by the previous chapters. We then consider major human impacts in these regions. Finally, we identify gaps in knowledge and make some suggestions for the way forward. We make the case for combining phylogeographic studies with macro-ecology and biogeography, coupled with well-designed hypothesis testing experiments, to better understand processes generating patterns on micro-evolutionary (hundreds to thousands of years) and ecological (up to hundreds of years) time scales.
Filamentary structures can form within the beam of protons accelerated during the interaction of an intense laser pulse with an ultrathin foil target. Such behaviour is shown to be dependent upon the formation time of quasi-static magnetic field structures throughout the target volume and the extent of the rear surface proton expansion over the same period. This is observed via both numerical and experimental investigations. By controlling the intensity profile of the laser drive, via the use of two temporally separated pulses, both the initial rear surface proton expansion and magnetic field formation time can be varied, resulting in modification to the degree of filamentary structure present within the laser-driven proton beam.
Freshwater mussels (Mollusca: Unionidae) are filter feeders that are relatively immobile, widely distributed and are known to concentrate trace metals in their shells (1,2,3). These characteristics make them good candidates for monitoring metal pollution in lakes and rivers. Another characteristic of mussels that make them particularly attractive as pollution monitors is the fact the shell is deposited in distinctive, annual growth layers. The concentrations of metals in these shell layers may provide a history ol the metals present in the environment where the mussel was collected.
To assess variability in antimicrobial use and associations with infection testing in pediatric ventilator-associated events (VAEs).
Descriptive retrospective cohort with nested case-control study.
Pediatric intensive care units (PICUs), cardiac intensive care units (CICUs), and neonatal intensive care units (NICUs) in 6 US hospitals.
Children≤18 years ventilated for≥1 calendar day.
We identified patients with pediatric ventilator-associated conditions (VACs), pediatric VACs with antimicrobial use for≥4 days (AVACs), and possible ventilator-associated pneumonia (PVAP, defined as pediatric AVAC with a positive respiratory diagnostic test) according to previously proposed criteria.
Among 9,025 ventilated children, we identified 192 VAC cases, 43 in CICUs, 70 in PICUs, and 79 in NICUs. AVAC criteria were met in 79 VAC cases (41%) (58% CICU; 51% PICU; and 23% NICU), and varied by hospital (CICU, 20–67%; PICU, 0–70%; and NICU, 0–43%). Type and duration of AVAC antimicrobials varied by ICU type. AVAC cases in CICUs and PICUs received broad-spectrum antimicrobials more often than those in NICUs. Among AVAC cases, 39% had respiratory infection diagnostic testing performed; PVAP was identified in 15 VAC cases. Also, among AVAC cases, 73% had no associated positive respiratory or nonrespiratory diagnostic test.
Antimicrobial use is common in pediatric VAC, with variability in spectrum and duration of antimicrobials within hospitals and across ICU types, while PVAP is uncommon. Prolonged antimicrobial use despite low rates of PVAP or positive laboratory testing for infection suggests that AVAC may provide a lever for antimicrobial stewardship programs to improve utilization.
The earliest generations of stars were produced in galaxies at high redshift. The physical conditions in which these stars formed, produced heavy elements and dust, and subsequently ended their life cycles, however, are vastly different from those in the Milky Way. Nearby low metal-abundance galaxies provide critical laboratories within which it is possible to observe conditions similar to those at high redshift, shedding light on the lifecycle of dust and metals in the early Universe. Does the process of star formation change at low metallicity? How did galaxies in the early Universe produce significant amounts of dust without the elapsed time necessary for stars to evolve to the asymptotic giant branch (AGB) phase and contribute via mass loss? Here we present work cataloging dust-producing sources in the nearby metal-poor galaxy NGC 6822 and outline forthcoming GTO observations of this system and the blue compact dwarf I Zw 18 with JWST.
Small perturbations to a steady uniform granular chute flow can grow as the material moves downslope and develop into a series of surface waves that travel faster than the bulk flow. This roll wave instability has important implications for the mitigation of hazards due to geophysical mass flows, such as snow avalanches, debris flows and landslides, because the resulting waves tend to merge and become much deeper and more destructive than the uniform flow from which they form. Natural flows are usually highly polydisperse and their dynamics is significantly complicated by the particle size segregation that occurs within them. This study investigates the kinematics of such flows theoretically and through small-scale experiments that use a mixture of large and small glass spheres. It is shown that large particles, which segregate to the surface of the flow, are always concentrated near the crests of roll waves. There are different mechanisms for this depending on the relative speed of the waves, compared to the speed of particles at the free surface, as well as on the particle concentration. If all particles at the surface travel more slowly than the waves, the large particles become concentrated as the shock-like wavefronts pass them. This is due to a concertina-like effect in the frame of the moving wave, in which large particles move slowly backwards through the crest, but travel quickly in the troughs between the crests. If, instead, some particles on the surface travel more quickly than the wave and some move slower, then, at low concentrations, large particles can move towards the wave crest from both the forward and rearward sides. This results in isolated regions of large particles that are trapped at the crest of each wave, separated by regions where the flow is thinner and free of large particles. There is also a third regime arising when all surface particles travel faster than the waves, which has large particles present everywhere but with a sharp increase in their concentration towards the wave fronts. In all cases, the significantly enhanced large particle concentration at wave crests means that such flows in nature can be especially destructive and thus particularly hazardous.
Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers (e.g. the Extreme Light Infrastructure). We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP, providing an opportunity for comparison with existing charge separation models.
Introduction: Hospital-based gun violence is devastatingly traumatic for everyone present and recent events in Cobourg, Ontario underscore that an active shooter inside the emergency department (ED) is an imminent threat. In June 2016, the Ontario Hospital Association (OHA) added Code Silver to the list of standardized emergency preparedness colour codes and advised member hospitals to develop policies and train staff on how best to respond. Given that EDs are particularly susceptible to opportunistic breach by an active shooter, the impact of a Code Silver on ED functioning and staff members may be particularly acute. We hypothesized that there may not be a simple, one-size-fits-all-hospital-staff solution about how best to prepare EDs to respond to Code Silver. In order to inform and support future staff training initiatives related to Code Silver and other disaster situations in hospitals, we sought to investigate staff perspectives and behaviour related to personal safety at work and, in particular, an active shooter. Methods: We undertook a qualitative interview study of multi-disciplinary ED staff (MDs, RNs, clericals, allied health, administrators) at a single tertiary care centre in Toronto. The primary methods for data collection were in-depth qualitative interviews and focus groups. Participants were recruited using stakeholder and maximum variation sampling strategies. Data collection and analysis were concurrent and standard thematic analysis techniques were employed. Results: Sixteen (16) staff members participated in interviews and 40 participated in small focus group discussions. Data analysis revealed workplace violence and personal health risks have been normalized as expected, acceptable features of everyday life at work in the ED given that patients are perceived to be sick people in need of help that ED staff are trained for and prepared to provide. In contrast, weapons and active shooters challenge the boundaries of professional responsibility and readiness to respond to Code Silver is perceived by staff as a fallacy. Conclusion: Knowledge from this study gives us crucial insight into important areas for targeted training and opportunities for knowledge translation on the topic of implementing Code Silver in EDs across the country. Future interventions must include how to overcome normalization of workplace violence in the ED setting and negotiating competing professional obligations during crisis situations. Attention to these are crucial if we are to truly keep our staff safe during these traumatic events.
Introduction: Online medical education resources are widely used in emergency medicine (EM), but strategies to assess quality remain elusive. We previously derived the Medical Education Translational Resources: Impact and Quality (METRIQ) 8 instrument to evaluate quality in medical education blog posts. Methods: As part of a subsequent validation study (The METRIQ Blog Study), a mixed-methods usability analysis was performed to obtain user feedback on the quality assessment instrument in order to improve its clarity and reliability. Participants in the METRIQ Study were first asked to rate five blog posts using the METRIQ-8 Score. They then evaluated the METRIQ-8 instruments ease of use and likelihood of being recommended to others using a 7-point Likert scale and free text comments. Participants were also asked to flag and comment on items within the score that they felt were unclear. Global usability ratings were summarized using median scores or percent rated unclear. We used ANOVA to test associations between ease of use and demographic factors. A thematic analysis was performed on the comments. Results: 309 EM medical students, residents, and attendings completed the survey. Global ratings were generally very favorable (median 2 [IQR 2-3], with 7 being the lowest score) for ease of use and likelihood of recommendation, and did not vary by participants country of origin, frequency of blog use, or learner level. Participants stated that the score was structured, systematic, and straightforward. They found it useful for junior learners and for guiding blog creation. Four questions in the score (questions 2, 4, 5, and 7) were identified by 10% of subjects to be unclear. Thematic analysis of comments identified suggested four main themes for improving the score: adding clearer definitions with marking rubrics; shortening the 7-point scale; adding items evaluating blog post presentation and utility; and, rephrasing the wording of certain questions for clarity. Conclusion: A mixed methods usability analysis of the METRIQ-8 instrument for assessing blog quality was globally well received by EM medical students, residents, and attendings. Qualitative analyses revealed multiple areas to improve the instruments clarity and usability. The METRIQ score is a promising instrument for evaluating the quality of blogs; further development and testing is needed to improve its utility.
In this study, we report the characterization of a 304L stainless steel cylindrical projectile produced by additive manufacturing. The projectile was compressively deformed using a Taylor Anvil Gas Gun, leading to a huge strain gradient along the axis of the deformed cylinder. Spatially resolved neutron diffraction measurements on the HIgh Pressure Preferred Orientation time-of-flight diffractometer (HIPPO) and Spectrometer for Materials Research at Temperature and Stress diffractometer (SMARTS) beamlines at the Los Alamos Neutron Science CEnter (LANSCE) with Rietveld and single-peak analysis were used to quantitatively evaluate the volume fractions of the α, γ, and ε phases as well as residual strain and texture. The texture of the γ phase is consistent with uniaxial compression, while the α texture can be explained by the Kurdjumov–Sachs relationship from the γ texture after deformation. This indicates that the material first deformed in the γ phase and subsequently transformed at larger strains. The ε phase was only found in volumes close to the undeformed material with a texture connected to the γ texture by the Shoji–Nishiyama orientation relationship. This allows us to conclude that the ε phase occurs as an intermediate phase at lower strain, and is superseded by the α phase when strain increases further. We found a proportionality between the root-mean-squared microstrain of the γ phase, dominated by the dislocation density, with the α volume fraction, consistent with strain-induced martensite α formation. Knowledge of the sample volume with the ε phase from the neutron diffraction analysis allowed us to identify the ε phase by electron back scatter diffraction analysis, complementing the neutron diffraction analysis with characterization on the grain level.
Accurate and reproducible patient positioning is a critical step in radiotherapy for breast cancer. This has seen the use of permanent skin markings becoming standard practice in many centres. Permanent skin markings may have a negative impact on long-term cosmetic outcome, which may in turn, have psychological implications in terms of body image. The aim of this study was to investigate the feasibility of using a semi-permanent tattooing device for the administration of skin marks for breast radiotherapy set-up.
Materials and methods
This was designed as a phase II double-blinded randomised-controlled study comparing our standard permanent tattoos with the Precision Plus Micropigmentation (PPMS) device method. Patients referred for radical breast radiotherapy were eligible for the study. Each study participant had three marks applied using a randomised combination of the standard permanent and PPMS methods and was blinded to the type of each mark. Follow up was at routine appointments until 24 months post radiotherapy. Participants and a blind assessor were invited to score the visibility of each tattoo at each follow-up using a Visual Analogue Scale. Tattoo scores at each time point and change in tattoo scores at 24 months were analysed by a general linear model using the patient as a fixed effect and the type of tattoo (standard or research) as covariate. A simple questionnaire was used to assess radiographer feedback on using the PPMS.
In total, 60 patients were recruited to the study, of which 55 were available for follow-up at 24 months. Semi-permanent tattoos were more visible at 24 months than the permanent tattoos. Semi-permanent tattoos demonstrated a greater degree of fade than the permanent tattoos at 24 months (final time point) post completion of radiotherapy. This was not statistically significant, although it was more apparent for the patient scores (p=0·071) than the blind assessor scores (p=0·27). No semi-permanent tattoos required re-marking before the end of radiotherapy and no adverse skin reactions were observed.
The PPMS presents a safe and feasible alternative to our permanent tattooing method. An extended period of follow-up is required to fully assess the extent of semi-permanent tattoo fade.