bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pilot Survey for National Point Prevalence Study of Healthcare-Associated Infections in Acute-Care Hospitals in South Korea
Authors: Lee Ji Young 
Published: November 2020

Background: The Korean National Healthcare-Associated Infections Surveillance System (KONIS) was established to conduct nationwide surveillance of device-associated healthcare-associated infections (HAIs) and surgical site infections annually in 2006. However, no surveillance on overall HAIs has been conducted. Objective: We conducted a point-prevalence survey of total HAIs to estimate the incidence rate of HAIs in acute-care hospitals in South Korea. Methods: We defined HAIs according to KONIS and NHSN criteria. In total, 29 acute-care hospitals including 9 tertiary-care hospitals (TCHs) and 20 secondary-care hospitals (SCHs) were recruited as representing the population of every metropolitan city and province in South Korea. Patients who stayed at the hospitals on August 1, 2018, were randomly selected: 100 for SCHs and 200 for TCHs. Their medical records were retrospectively reviewed for HAIs according to the NHSN criteria by the infection control nurses (ICNs) from each hospital. A web-based data collection and analysis program was developed, and participating ICNs were educated in a 1-day training course with pre- and postevaluations. They received continuous feedback of input data and questions through the web-based system during the study. To generate estimates of the incidence rate of HAIs, we converted prevalence to incidence using the formula of Rhame and Sudderth. Results: Of 4,296 patients, 133 had ≥1 HAI (3.1%). In total, 141 HAIs were identified: gastrointestinal infections (n = 30, 21.3%), bloodstream infections (n = 30, 21.3%), pneumonia (n = 29, 20.6%), urinary tract infection (n =26, 18.4%). Among the gastrointestinal infections, C. difficile infections were the most common (17.7%). Device-associated infections accounted for 34.8% of all HAIs. The overall incidence of HAIs in TCHs was 4.39%, which was a higher incidence than SCHs (3.76%). Intensive care units had 12.6% of HAIs, whereas general wards had 3.4%. HAI incidences were 5.7%, 2.8%, and 2.3%, respectively, for each of the medical wards, surgical wards, and pediatric wards. The 3 most common pathogens were Escherichia coli, Acinetobacter baumannii, and Enterococcus faecium. Conclusions: The prevalence of HAI in Korea is lower than in most Western countries. The HAI burden of Clostridium difficile infection is surprisingly high, which calls for prompt control at the national level. To obtain national-level data on HAI burdens, ongoing surveillance is needed.Funding: NoneDisclosures: None
Procalcitonin Use in a Large Community Healthcare System
Authors: Cooper Mandelin , Burgess Hayley , Cuthbert Jeffrey , Septimus Edward Joel , Signorelli Heather 
Published: November 2020

Background:
Appropriate testing of blood procalcitonin (PCT) can potentially inform antibiotic de-escalation in patients with severe infections. When used along with observed clinical improvements, PCT testing can support antimicrobial stewardship. However, this testing must be used optimally to ensure that it is actionable, cost-effective, and provides patient benefit. Although this test is widely used, little is known about the appropriateness of this testing in select populations. Methods: In this retrospective review, we evaluated PCT monitoring patterns and appropriateness of use and relationship to antibiotic days of therapy in a system of community hospitals. We evaluated the use of PCT testing in patients with known confounders, namely pregnancy, chronic kidney disease, or neutropenia, which we classified as “inappropriate use” because these conditions can affect the interpretation of PCT results. We also evaluated the relationship between PCT testing and antibiotic days of therapy for patients with sepsis, pneumonia, or lower respiratory tract infections. Results: In a 1-year period, ∼206,302 PCT tests were performed at 146 facilities, an average of ∼1,413 per facility per year. Approximately 27.7% of these tests were given to patients who were pregnant or had a confounding comorbidity such as chronic kidney disease or neutropenia. Of these “inappropriate” tests, >90% were given to patients with chronic kidney disease. Older patients (aged 60–80 years, n = 93,021) were more likely to receive a PCT test while also having a confounding comorbidities; 24% of older patients with a PCT test also had chronic kidney disease. Of all patients with a PCT test and chronic kidney disease, ∼76% were also diagnosed with either sepsis, pneumonia, or lower respiratory tract infections. Conclusions: Confounding conditions can affect PCT levels independently of infection. Additionally, some clinicians use PCT tests as probes for other physiological maladies. This analysis demonstrated that there is opportunity for education about the appropriate use of this test, how to interpret results in the presence of confounding conditions, and how to transform PCT test results into actions that facilitate antimicrobial stewardship and better patient care.Funding: NoneDisclosures: None
Tellurium in Late Permian‐Early Triassic Sediments as a Proxy for Siberian Flood Basalt Volcanism
Authors: Regelous Marcel , Regelous Anette , Grasby Stephen E. , Bond David P. G. , Haase Karsten M. , Gleißner Stefan , Wignall Paul B. 
Published: October 2020

AbstractWe measured the concentrations of trace elements in Late Permian to Early Triassic sediments from Spitsbergen. High mercury concentrations in sediments from the level of the Permo‐Triassic Mass Extinction (PTME) at this location were previously attributed to the emplacement of the Siberian Traps Large Igneous Province and used to link the timing of volcanism with the record of environmental change and extinction in these sediments. We investigated the use of the moderately to highly volatile, siderophile elements Ni, Zn, Cd, Sb, Te, Re, and Tl as proxies for the intensity of Siberian volcanism. These trace elements, like Hg, have high concentrations in volcanic gas compared to crustal rocks. Tellurium is highly enriched at the PTME, and Te/Th ratios increase by a factor of ∼20 across the PTME, similar to the variation in Hg/total organic carbon (TOC) in the same samples. Te/Th and Hg/TOC values imply that Siberian volcanism initiated at the onset of the PTME, coincident with the start of the δ13Corganic excursion and abrupt warming. Based on Te and Hg, most Siberian volcanism occurred between the two phases of the PTME boundary (a period of less than 100 ky), but also continued into the Early Triassic. The duration of Siberian volcanism inferred from Te/Th and Hg/TOC is shorter than that indicated by recent high‐precision U‐Pb ages of Siberian intrusive and extrusive rocks. Te concentrations and Te/Th ratios in sediments represent a useful new proxy for volcanism, which can be used to link the marine sedimentary record with large volcanic events on land.
Investigating Recent Changes in MJO Precipitation and Circulation in Multiple Reanalyses
Authors: Hsiao Wei‐Ting , Maloney Eric D. , Barnes Elizabeth A. 
Published: October 2020

AbstractRecent work using CMIP5 models under RCP8.5 suggests that individual multimodel mean changes in precipitation and wind variability associated with the Madden‐Julian oscillation (MJO) are not detectable until the end of the 21st century. However, a decrease in the ratio of MJO circulation to precipitation anomaly amplitude is detectable as early as 2021–2040, consistent with an increase in dry static stability as predicted by weak temperature gradient balance. Here, we examine MJO activity in multiple reanalyses (ERA5, MERRA‐2, and ERA‐20C) and find that MJO wind and precipitation anomaly amplitudes have a complicated time evolution over the record. However, a decrease in the ratio of MJO circulation to precipitation anomaly amplitude is detected over the observational period, consistent with the change in dry static stability. These results suggest that weak temperature gradient theory may be able to help explain changes in MJO activity in recent decades.
Origins of Major Element, Trace Element, and Isotope Garnet Signatures in Mid‐Ocean Ridge Basalts
Authors: Krein Stephanie Brown , Behn Mark Dietrich , Grove Timothy Lynn 
Published: October 2020

AbstractTo investigate whether the source of the globally occurring garnet signature in mid‐ocean ridge basalt (MORB) is “true” (imparted by melting a garnet‐bearing source) or “apparent” (produced without the involvement of garnet), we present the basalt petrogenesis model Petrogen. Petrogen is built on Kinzler and Grove (1992a, https://doi.org/10.1029/91JB02841) and Behn and Grove (2015, https://doi.org/10.1002/2015JB011885) and calculates the major element, trace element, and isotopic compositions of primary lherzolite‐saturated mantle melts and their subsequent evolution to eruption. This model is experimentally calibrated for melting in the plagioclase, spinel, and garnet fields with and without small amounts of water. Petrogen predicts that garnet‐lherzolite melting requires small mantle porosity (ϕ = ∼0.1%) and enriched (NaK# > 0.1), hot (>1400–1450°C), and damp mantle (>350–700 ppm water) sources. When garnet‐lherzolite melting does occur, the fraction of melting that takes place in the garnet field is not sufficient to impart a recognizable true garnet signature in the major and trace element composition of pooled melts except at ultraslow‐spreading rates (half rate ≤ 0.5 cm/yr). Therefore, for ambiguous garnet trace element signatures in MORB to be “true” would require that they are near‐fractional garnet‐lherzolite melts or garnet‐pyroxenite melts diluted by mixing in random proportions. While we do not test the process of random mixing, we find that near‐fractional and pooled melts of variable major and trace element mantle peridotite compositions at different mantle potential temperatures can explain the range of garnet signatures in MORB. For spinel‐peridotite melting to support garnet signatures requires mantle porosities ϕ = ∼0.1%; however, plagioclase‐peridotite melting, under specific circumstances, can explain MORB garnet signatures with ϕ = ∼1%.
P Wave Tomography Beneath Greenland and Surrounding Regions: 1. Crust and Upper Mantle
Authors: Toyokuni Genti , Matsuno Takaya , Zhao Dapeng 
Published: October 2020

AbstractWe study the 3‐D P wave velocity (Vp) structure of the crust and upper mantle beneath Greenland and surrounding regions using the latest P wave arrival time data. The Greenland Ice Sheet Monitoring Network (GLISN), initiated in 2009, is an international project for seismic observation in these regions using 34 stations. We use a regional seismic tomography method to simultaneously invert P wave arrival times of local earthquakes and P wave relative traveltime residuals of teleseismic events. These data are extracted from the ISC‐EHB catalog; however, for the teleseismic data, we picked new arrival times from seismograms using a cross‐correlation method. Our tomographic results clearly reveal the Iceland plume, the Jan Mayen plume, and a newly discovered “Svalbard plume,” which merge together in the mantle transition zone. A high‐Vp body exists beneath the Greenland Sea, which might act as an obstacle against the rising Svalbard plume. Furthermore, our results reveal a remarkable low‐Vp anomaly elongated in the NW‐SE direction at depths ≤250 km beneath central Greenland, which is connected with the Iceland and Jan Mayen hotspots. Although previous studies have suggested a similar feature, our result is the first to show the low‐Vp zone existing at all depths in the Greenland lithosphere, and its spatial distribution coincides with a high heat flux region. These characteristics indicate that the low‐Vp zone reflects residual heat from the Iceland plume when the Greenland lithosphere passed over this plume at ~80–20 Ma. Our results also indicate the possible existence of residual heat from the Jan Mayen plume.
Temporal Variations of the Marine Geoid
Authors: Siegismund F. , Köhl A. , Rummel R. , Stammer D. 
Published: October 2020

AbstractThe effects of temporal changes in the marine geoid on estimates of the ocean dynamic topography are being investigated. Influences from mass redistribution due to changes of land hydrology, ice sheets, glacial isostatic adjustment (GIA), and ocean and atmospheric dynamics are considered, and the associated crustal deformation is included. The strongest signals are associated with the seasonal cycle caused by changes in terrestrial water storage and ice sheets as well as the redistribution of atmospheric mass. Second to this is the importance of an overall trend caused by GIA and decreasing ice sheets over Greenland and Antarctica. On long spatial scales, the amplitude of regional trends estimated for the geoid height has a sizable fraction of those from sea level anomaly (SLA) for the period 1993–2016, also after subtraction of steric height of the upper 1,000 m to analyze trends in deep ocean geostrophic currents. The estimated strong negative geoid height trend south of Greenland for the period 1993–2016 opposes changes in dynamic sea level for the same period thereby affecting past studies on changes of both the strength of the subpolar gyre based on SLA and the meridional overturning circulation on a section between Cape Farewell and Portugal applying ocean dynamic topography and hydrography. We conclude that temporal geoid height trends should be considered in studies of (multi)decadal trends in sea level and circulation on large spatial scales based on altimetry data referenced to a geoid field.
Weak Response of Biological Productivity and Community Structure of Phytoplankton to Mesoscale Eddies in the Oligotrophic Philippine Sea
Authors: Yun Mi Sun , Kim Yejin , Jeong Yubeen , Joo Hui Tae , Jo Young‐Heon , Lee Chang Hwa , Bae Hyeonji , Lee Dabin , Bhavya P. S. , Kim Dongseon , Sun Jun , Lee Sang H. 
Published: October 2020

AbstractIn the Philippine Sea, mesoscale eddies have been frequently observed, but little is known about their contributions to the biological productivity and community structure of phytoplankton in the region. In situ carbon and nitrogen uptake rates and phytoplankton community structure were investigated in the Philippine Sea based on the 13C‐15N dual‐tracer technique and photosynthetic pigment analysis from late August to September 2018. Based on the comparison of the phytoplankton community structure among the cold eddy, warm eddy, and outer area, we found that the phytoplankton composition was different in the warm eddy with relatively lower contributions of large phytoplankton. However, a distinct enhancement in phytoplankton biomass over the euphotic zone was not detected even in eddy occurrence. In terms of community, the picoplankton Prochlorococcus was persistently dominant, which was attributed to a low supply and chemical composition of nutrients. The average integrated primary productions (IPP) were 80.4, 75.9, and 76.3 mg C m−2d−1 for the cold eddy, warm eddy, and outer area, respectively. The IPP under the eddy condition was not largely different from that in reference sites, even though the vertical distribution of productivity maximum was found to be different depending on eddy condition. These weak biological responses to mesoscale eddies might be attributed to the sustaining picoplankton‐dominant community structure and no substantial upward inputs of nutrients to the euphotic zone. Our findings represent an important contribution to understanding the biological response of mesoscale eddies in the oligotrophic Philippine Sea.
Inherent Optical Properties‐Reflectance Relationships Revisited
Authors: Lo Prejato Marilisa , McKee David , Mitchell Catherine 
Published: October 2020

AbstractUnderstanding the relationship between remote sensing reflectance, Rrs(λ) and the inherent optical properties (IOPs) of natural waters is potentially a key to improving our ability to determine biogeochemical constituents from radiometric measurements. These relationships are usually described as a function of absorption, a(λ), and backscattering, bb(λ), coefficients, with the literature providing various forms of equation operating on either bb(λ)/a(λ) or bb(λ)/[a(λ)+bb(λ)] to represent the impact of variations in light field geometries and changes in sea‐water composition. The performance of several IOP‐reflectance relationships is assessed using HydroLight radiative transfer simulations covering a broad range of Case 1 and Case 2 water conditions. While early versions of IOP‐reflectance relationships assigned variability to associated proportionality factors (e.g., f/Q) or low‐order polynomial functions, recent studies have demonstrated relationships between Rrs(λ) and bb(λ)/[a(λ)+bb(λ)] are well‐characterized by nonlinear (high‐order polynomial), monotonic functions. This study demonstrates that this approach is also valid for relationships operating on bb(λ)/a(λ) and that there is no intrinsic benefit to functions operating on bb(λ)/[a(λ)+bb(λ)] compared to bb(λ)/a(λ) for Case 2 waters, contrary to recent suggestions in the literature. In all cases it is necessary to carefully consider the performance of best fit relationships across the full range of variability of IOPs and Rrs(λ), with higher order polynomials required to enable equivalent performance across the range of natural variability. The analysis further demonstrates insignificant wavelength sensitivity across the visible region, limited sensitivity to changes in solar zenith angle and extends to relationships for below surface remote sensing reflectance, rrs(λ).
Parameterizations of Entrainment‐Mixing Mechanisms and Their Effects on Cloud Droplet Spectral Width Based on Numerical Simulations
Authors: Luo Shi , Lu Chunsong , Liu Yangang , Bian Jianchun , Gao Wenhua , Li Junjun , Xu Xiaoqi , Gao Sinan , Yang Suying , Guo Xiaohao 
Published: October 2020

AbstractEntrainment‐mixing mechanisms significantly affect cloud droplet number concentration, radius, and spectral shape. Quantitative examination of entrainment‐mixing effects on cloud droplet spectral width is lacking. This study examines the effects of entrainment‐mixing processes on cloud microphysics by 12,218 different setups, each simulated 10 times using the Explicit Mixing Parcel Model (EMPM) driven by the observational data from the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX‐III) campaign. Parameterizations of entrainment‐mixing mechanisms are developed by relating homogeneous mixing degree to transition scale number that depends on the dissipation rate and droplet evaporation time scale. The correlation between relative dispersion of cloud droplet size distribution and homogeneous mixing degree changes from negative to positive with the decreasing homogeneous mixing degree. The different relationships are closely related to the competition between complete and partial droplet evaporation and the number concentration of small droplets, which are quantitatively described by two newly introduced dimensionless numbers. The competition is significantly affected by relative humidity and mixing fraction of entrained air as well as turbulence dissipation rate, but not much by cloud droplet number concentration. Especially, when relative humidity and dissipation rate are high, there is only a negative correlation. This study sheds new light on generalizing the homogeneous/inhomogeneous concept by considering relative dispersion and also provides parameterizations of entrainment‐mixing processes and relative dispersion for atmospheric models.
Identification of Sea Breeze Recirculation and Its Effects on Ozone in Houston, TX, During DISCOVER‐AQ 2013
Authors: Li Wei , Wang Yuxuan , Bernier Claudia , Estes Mark 
Published: October 2020

AbstractIn coastal environments, sea breeze recirculation has been found to be an important mesoscale meteorological phenomenon that causes high ozone episodes, yet the identification of this small‐scale circulation pattern remains difficult. In this study, a new method was developed to automatically identify sea breeze recirculation in Houston, TX, by applying K‐Means clustering algorithm to surface winds measurements at near‐coast sites during the DISCOVER‐AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign period from August to October 2013. The key to the clustering algorithm is seven features derived from site‐based surface winds on each day, including zonal (U) and meridional (V) winds in the morning and afternoon, 24‐hr transport direction (θ) and the recirculation factor, which is the ratio of net transport distance (L) to wind run distance (S). For comparison, the same clustering was applied to San Antonio, TX, a noncoastal city yet within the synoptic‐scale distance from Houston. Four clusters were obtained for each region, including three synoptic patterns common to both regions and one mesoscale pattern that differs by region, classified as Stagnation and Sea Breeze Cluster for San Antonio and Houston, respectively. The clustering outputs were verified by wind profiler data in Houston. By linking the wind clusters with surface and aircraft ozone measurements, we revealed a clear connection between circulation patterns and daily ozone variability showing that maximum daily average 8‐hr (MDA8) ozone levels and spatial distributions differed by cluster type (e.g., the highest ozone found in the Stagnation/Sea Breeze Cluster and the lowest ozone in the Southerly Cluster). This automatable method of sea breeze identification we developed can be potentially applied to other coastal cities because it has low data requirement and no ad hoc location‐specific adjustments.
Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet
Authors: Ward Jamie L. , Flanner Mark G. , Dunn‐Sigouin Etienne 
Published: October 2020

AbstractClouds and blocking activity have been implicated as causes of increased Greenland Ice Sheet (GrIS) melt in the 21st century. Although Greenland blocks (i.e., long‐lasting, mostly stationary anticyclones) generally reduce cloud cover and move warm air over Greenland, the elevated GrIS perturbs air and moisture transport in complex ways, implying a need to better understand how blocks affect cloud and surface energy flux anomaly patterns. In this study, we use a combination of daily MODIS cloud data and meteorological and energy flux data from MERRA‐2 reanalysis to better understand how Greenland block location, separated into four equal‐area quadrants, affects regional cloud and surface energy flux spatial patterns in the summer months of 2002–2018. Overall, cloud fraction and cloud water path reductions are approximately four times greater during northern block days than southern block days. Net cloud radiative forcing anomalies are negative for all Greenland block locations because negative longwave cloud radiative forcing anomalies exceed positive shortwave cloud radiative forcing changes. However, greater cloud cover reductions during northern block days produce more negative net cloud radiative forcing anomalies than southern block days. Greenland‐average (i.e., latitude‐weighted average of all GrIS grids) net surface energy flux anomalies range from +7 to +12W/m2 for all block quadrants. While net shortwave energy anomalies dominate the total surface energy response during western Greenland block days, sensible heating is responsible for approximately half of positive total surface energy change during eastern Greenland block days.