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We present the analysis of global sympagic primary production (PP) from 300 years of pre-industrial and historical simulations of the E3SMv1.1-BGC model. The model includes a novel, eight-element sea ice biogeochemical component, MPAS-Seaice zbgc, which is resolved in three spatial dimensions and uses a vertical transport scheme based on internal brine dynamics. Modeled ice algal chlorophyll-a concentrations and column-integrated values are broadly consistent with observations, though chl-a profile fractions indicate that upper ice communities of the Southern Ocean are underestimated. Simulations of polar integrated sea ice PP support the lower bound in published estimates for both polar regions with mean Arctic values of 7.5 and 15.5 TgC/a in the Southern Ocean. However, comparisons of the polar climate state with observations, using a maximal bound for ice algal growth rates, suggest that the Arctic lower bound is a significant underestimation driven by biases in ocean surface nitrate, and that correction of these biases supports as much as 60.7 TgC/a of net Arctic PP. Simulated Southern Ocean sympagic PP is predominantly light-limited, and regional patterns, particularly in the coastal high production band, are found to be negatively correlated with snow thickness.
Background: With advancements in technology, the use of video as a pedagogical method in medical education has gained in popularity, and may aid in teaching clinical skills. In the UBC MD program, videos have been used to assist in teaching the -neurological exam for several decades, but the currently available videos are outdated and not of contemporary quality. Methods: Drawing upon the cognitive theory of multimedia learning from Mayer and Moreno (2003) which describes methods to maximize learning by minimizing cognitive load, we developed a tool to systematically assess pedagogical videos. We inventoried twelve existing neurology videos and analyzed their use of methods such as weeding (removing extraneous information), signalling (visually highlighting important information), and chunking (grouping similar information together). Results: Generally, older videos had poor audiovisual quality that introduced extraneous load, while more current videos had higher production value, albeit inconsistent with the depth of their content. We therefore produced a new three-part neurological exam video series. We wrote storyboards, filmed with a focus on visually depicting the exam and findings, and edited to elucidate relevant physiological concepts. Conclusions: The end product has been adopted by the UBC MD program, and can be shared with other programs who may wish to adopt them.
To determine whether probiotic prophylaxes reduce the odds of Clostridium difficile infection (CDI) in adults and children.
Individual participant data (IPD) meta-analysis of randomized controlled trials (RCTs), adjusting for risk factors.
We searched 6 databases and 11 grey literature sources from inception to April 2016. We identified 32 RCTs (n=8,713); among them, 18 RCTs provided IPD (n=6,851 participants) comparing probiotic prophylaxis to placebo or no treatment (standard care). One reviewer prepared the IPD, and 2 reviewers extracted data, rated study quality, and graded evidence quality.
Probiotics reduced CDI odds in the unadjusted model (n=6,645; odds ratio [OR] 0.37; 95% confidence interval [CI], 0.25–0.55) and the adjusted model (n=5,074; OR, 0.35; 95% CI, 0.23–0.55). Using 2 or more antibiotics increased the odds of CDI (OR, 2.20; 95% CI, 1.11–4.37), whereas age, sex, hospitalization status, and high-risk antibiotic exposure did not. Adjusted subgroup analyses suggested that, compared to no probiotics, multispecies probiotics were more beneficial than single-species probiotics, as was using probiotics in clinical settings where the CDI risk is ≥5%. Of 18 studies, 14 reported adverse events. In 11 of these 14 studies, the adverse events were retained in the adjusted model. Odds for serious adverse events were similar for both groups in the unadjusted analyses (n=4,990; OR, 1.06; 95% CI, 0.89–1.26) and adjusted analyses (n=4,718; OR, 1.06; 95% CI, 0.89–1.28). Missing outcome data for CDI ranged from 0% to 25.8%. Our analyses were robust to a sensitivity analysis for missingness.
Moderate quality (ie, certainty) evidence suggests that probiotic prophylaxis may be a useful and safe CDI prevention strategy, particularly among participants taking 2 or more antibiotics and in hospital settings where the risk of CDI is ≥5%.
Children with CHD and acquired heart disease have unique, high-risk physiology. They may have a higher risk of adverse tracheal-intubation-associated events, as compared with children with non-cardiac disease.
Materials and methods
We sought to evaluate the occurrence of adverse tracheal-intubation-associated events in children with cardiac disease compared to children with non-cardiac disease. A retrospective analysis of tracheal intubations from 38 international paediatric ICUs was performed using the National Emergency Airway Registry for Children (NEAR4KIDS) quality improvement registry. The primary outcome was the occurrence of any tracheal-intubation-associated event. Secondary outcomes included the occurrence of severe tracheal-intubation-associated events, multiple intubation attempts, and oxygen desaturation.
A total of 8851 intubations were reported between July, 2012 and March, 2016. Cardiac patients were younger, more likely to have haemodynamic instability, and less likely to have respiratory failure as an indication. The overall frequency of tracheal-intubation-associated events was not different (cardiac: 17% versus non-cardiac: 16%, p=0.13), nor was the rate of severe tracheal-intubation-associated events (cardiac: 7% versus non-cardiac: 6%, p=0.11). Tracheal-intubation-associated cardiac arrest occurred more often in cardiac patients (2.80 versus 1.28%; p<0.001), even after adjusting for patient and provider differences (adjusted odds ratio 1.79; p=0.03). Multiple intubation attempts occurred less often in cardiac patients (p=0.04), and oxygen desaturations occurred more often, even after excluding patients with cyanotic heart disease.
The overall incidence of adverse tracheal-intubation-associated events in cardiac patients was not different from that in non-cardiac patients. However, the presence of a cardiac diagnosis was associated with a higher occurrence of both tracheal-intubation-associated cardiac arrest and oxygen desaturation.
Los Angeles County's civil service rule specifies a 70% cutoff score regardless of the situation (type of job, type of assessment, or outcome of interest). This civil service rule would be difficult to defend if it were challenged in court, and the rule places the county at increased risk in the event of employment litigation, particularly with public safety jobs (police, fire, sheriff, etc.). Additionally, it is unlikely that this cutoff would optimally balance the county's interests in fair employment practices and expected job performance (SIOP, 2003). Given the propensity for public safety candidates and employees to file lawsuits related to hiring and promotions, and given the fact that public safety agencies in this county have been subjected to a number of employment-related lawsuits in the past, the current rule is problematic. Prior to this rule's development, as well as after its implementation in 1988, there has been substantial litigation related to cutoff scores, and courts have identified what they consider to be more and less appropriate methods for setting cutoff scores.
Emerging applications require batteries to have both high energy and high power which are not necessarily compatible. The typical inverse relationship between power and energy in batteries is often due to the slow ion diffusion in electrode materials. While the optimization of current battery technology may be sufficient to fully address this issue, we present here that novel chemistry-focused strategies based on new fundamental understanding of materials may be applied to lead to the development of a new generation of batteries that store energy sufficiently and deliver it rapidly.
Multiwall carbon nanotubes (MWCNTs) are utilized to resolve low coupling coefficient issue by dispersing MWCNTs in poly(vinylidene fluoride) matrix to create stress reinforcing network, dispersant, and electron conducting functions for barium titanate (BT) nanoparticles. Various BT and MWCNT percentages of nanocomposite film are fabricated by FDM three-dimensional (3D) printing which can simplify the fabrication process as well as lower cost and design flexibility. Increasing MWCNTs and BT particles gradually increase piezoelectric coefficient (d31) by 0.13 pC/N with 0.4 wt%-MWCNTs/18 wt%-BT. These results provide not only a technique to print piezoelectric nanocomposites but also unique materials combination for sensor application.
Single-walled carbon nanotube (SWNT) radical anions will react with tetrahydrofuran and generate ethylene, enolates, and a partially hydrogenated nanotube backbone. The experimental evidence suggests that there are sp3 C–H binding interactions. The total gravimetric content of hydrogen on a sample averages from 3.5% to 3.9% w/w, about four times the total amount observed for nanotubes hydrogenated via traditional Birch reduction reactions. Furthermore, the hydrogen desorbs at temperatures up to 400 °C less than those observed for the hydrogenated SWNTs formed after the Birch reduction. Finally, the first room temperature electron spin resonance spectrum of a nanotube radical ion is also reported.
This study uses the eastern Canadian continental margin as a type example to assess controls on the distribution of different types of submarine landslides. A brief summary is provided of the major styles of submarine landslides recognized globally, their transport mechanisms, and the factors responsible for both preconditioning and triggering failure. The eastern Canadian continental margin differs along its length as a result of the northward-decreasing age of oceanic rifting and resulting depth of the ocean floor. It has been strongly modified by Quaternary glaciation. Landslides on the margin are recognized from 2D and 3D seismic data, multibeam bathymetry, and 10-m-long cores. The ages of landslides are well defined from regional stratigraphic studies. The distribution of different types of landslides on the eastern Canadian margin depends on whether the margin is progradational or erosional. Progradational slopes have unconsolidated sediment available for retrogressive slumps, whereas on more erosional slopes more consolidated sediment is available to form blocky disaggregated landslides. Most large landslides appear to result from regional failure during large, but rare, passive-margin earthquakes. Preconditioning factors such as sedimentation rate or flux of basinal fluids do not seem to have had a major impact on the distribution of larger failures, but could be locally significant for small landslides.
Despite the importance of Supreme Court opinions for the American polity, scholars have dedicated little systematic research to investigating the factors that contribute to the content of the justices’ opinions. In this article, we examine the ability of lower federal courts to shape the content of Supreme Court opinions. We argue that lower court opinions will influence the content of the Court’s opinions to the extent that the justices perceive that integrating language from lower court opinions will aid them in making efficacious law and policy. Utilizing plagiarism detection software to compare lower federal court opinions with the majority opinions of the Supreme Court during the 2002–2004 terms, we uncover evidence that the Court systematically incorporates language from the lower federal courts into its majority opinions.
We expected that the commentary process would provide valuable feedback to improve our ideas and identify potential obstacles, and we were not disappointed. The commentaries were generally in agreement that synthetic validity is a good idea, although we also received a fair amount of suggestions for improvements, conditional or tempered praise, and explicitly critical comments. We address the concerns that were raised and conclude that we should move forward with developing a large-scale synthetic validity database, incorporating the suggestions of some of the commentators.
Although synthetic validation has long been suggested as a practical and defensible approach to establishing validity evidence, synthetic validation techniques are infrequently used and not well understood by the practitioners and researchers they could most benefit. Therefore, we describe the assumptions, origins, and methods for establishing validity evidence of the two primary types of synthetic validation techniques: (a) job component validity and (b) job requirements matrix. We then present the case for synthetic validation as the best approach for many situations and address the potential limitations of synthetic validation. We conclude by proposing the development of a comprehensive database to build prediction equations for use in synthetic validation of jobs across the U.S. economy and reviewing potential obstacles to the creation of such a database. We maintain that synthetic validation is a practically useful methodology that has great potential to advance the science and practice of industrial and organizational psychology.
Mineralogy and Remote Sensing of Rocks, Soil, Dust, and Ices
J. F. Bell, Cornell University, Department of Astronomy, 402 Space Sciences Building, Ithaca, NY 14853-6801, USA,
W. M. Calvin, Department of Geological Science, MS 172, University of Nevada Reno, NV 89557-0138, USA,
W. H. Farrand, Space Science Institute 4750 Walnut Street, # 205 Boulder, CO 80301, USA,
R. Greeley, Planetary Geology Group Arizona State University Tempe, AZ 85287-1404, USA,
J. R. Johnson, US Geological Survey Astrogeology Team 2255 N. Gemini Drive Flagstaff, AZ 86001-1698, USA,
B. Jolliff, Washington University, Campus Box 1169 One Bookings Drive St Louis, MO 63130, USA,
R. V. Morris, NASA/JSC Code KR, Building 31, Room 120 2101 NASA Road 1 Houston, TX 77058, USA,
R. J. Sullivan, CRSR Cornell University, 308 Space Sciences Building Ithaca, NY 14853, USA,
S. Thompson, Arizona State University, School of Earth and Space Exploration Box 871404 Tempe, AZ 85287, USA,
A. Wang, Department of Earth & Planetary Sciences, Washington University, Campus Box 1196 1 Bookings Drive St Louis, MO 63130-4862, USA,
C. Weitz, Planetary Science Institute, NASA 1700 East Fort Lowell Suite 106 Tuscon, AZ 85719, USA,
S. W. Squyres, Department of Astronomy, Cornell University, 428 Space Sciences Building, Ithaca, NY 14853, USA
Multispectral imaging from the Panoramic Camera (Pancam) instruments on the Mars Exploration Rovers (MERs) Spirit and Opportunity has provided important new insights about the geology and geologic history of the rover landing sites and traverse locations in Gusev crater and Meridiani Planum. Pancam observations from near-UV to near-infrared (NIR) wavelengths provide limited compositional and mineralogic constraints on the presence, abundance, and physical properties of ferric- and ferrous-iron–bearing minerals in rocks, soils, and dust at both sites. High-resolution and stereo morphologic observations have also helped to infer some aspects of the composition of these materials at both sites. Perhaps most importantly, Pancam observations were often efficiently and effectively used to discover and select the relatively small number of places where in situ measurements were performed by the rover instruments, thus supporting and enabling the much more quantitative mineralogic discoveries made using elemental chemistry and mineralogy data. This chapter summarizes the major compositionally and mineralogically relevant results at Gusev and Meridiani derived from Pancam observations. Classes of materials encountered in Gusev crater include outcrop rocks, float rocks, cobbles, clasts, soils, dust, rock grindings, rock coatings, windblown drift deposits, and exhumed whitish/yellowish sulfur- and silica-rich soils. Materials studied in Meridiani Planum include sedimentary outcrop rocks, rock rinds, fracture fills, hematite spherules, cobbles, rock fragments, meteorites, soils, and windblown drift deposits. This chapter also previews the results of a number of coordinated observations between Pancam and other rover-based and Mars-orbital instruments that were designed to provide complementary new information and constraints on the mineralogy and physical properties of Martian surface materials.
Carbon single-walled nanotubes (SWNTs) have been studied extensively as hydrogen storage materials. Herein, a novel hydrogen sorbtion behavior was observed for alkali metal reduced SWNTs and the mechanism of hydrogen binding in these materials has now been elucidated. SWNTs prepared by laser vaporization and purified by oxidation were reduced with Na in combination with naphthalene in tetrahydrofuran (THF) solution. The product, initially formulated as (Na+)xSWNTx-, was dark colored and insoluble in all common solvents examined. Temperature programmed desorption studies showed that hydrogen amounting to 3.5-4.2% w/w was released between 200 and 500°C from the Na-reduced material. This is consistent with hydrogenation of the reduced nanotubes to form C-H bonds with a C2H empirical formula. It appears that SWNT radical anions produced by reaction with sodium deprotonate THF to form hydrogenated nanotubes and the THF cleavage products ethylene and sodium enolate, as confirmed by isotope labeling. A structure consisting of pairs of lines of C-H units that spiral about the long tube axis with a coverage of 50% of the tube carbons is proposed.