Observed Relationship between Ozone and Temperature for Urban Nonattainment Areas in the United States

This study examined the observed relationship between ozone (O3) and temperature using data from 1995 to 2020 at 20 cities across the United States (U.S.) that exceed the O3 National Ambient Air Quality Standard (NAAQS). The median slope of the O3 versus temperature relationship decreased from 2.8 to 1.5 parts per billion per degrees Celsius (ppb °C−1) in the eastern U.S., 2.2 to 1.3 ppb °C−1 in the midwestern U.S., and 1.7 to 1.1 ppb °C−1 in the western U.S. O3 in the eastern and midwestern U.S. has become less correlated with temperature due to emission controls. In the western U.S., O3 concentrations have declined more slowly and the correlation between O3 and temperature has changed negligibly due to the effects of high background O3 and wildfire smoke. This implies that meeting the O3 NAAQS in the western U.S. will be more challenging compared with other parts of the country.

Measures of Interjoint Coordination Post-stroke Across Different Upper Limb Movement Tasks

Background: Deficits in interjoint coordination, such as the inability to move out of synergy, are frequent symptoms in stroke subjects with upper limb impairments that hinder them from regaining normal motor function. Kinematic measurements allow a fine-grained assessment of movement pathologies, thereby complementing clinical scales, like the Fugl–Meyer Motor Assessment of the Upper Extremity (FMMA-UE). The study goal was to investigate the effects of the performed task, the tested arm, the dominant affected hand, upper limb function, and age on spatiotemporal parameters of the elbow, shoulder, and trunk. The construct validity of the metrics was examined by relating them with each other, the FMMA-UE, and its arm section.Methods: This is a cross-sectional observational study including chronic stroke patients with mild to moderate upper limb motor impairment. Kinematic measurements were taken using a wearable sensor suit while performing four movements with both upper limbs: (1) isolated shoulder flexion, (2) pointing, (3) reach-to-grasp a glass, and (4) key insertion. The kinematic parameters included the joint ranges of shoulder abduction/adduction, shoulder flexion/extension, and elbow flexion/extension; trunk displacement; shoulder–elbow correlation coefficient; median slope; and curve efficiency. The effects of the task and tested arm on the metrics were investigated using a mixed-model analysis. The validity of metrics compared to clinically measured interjoint coordination (FMMA-UE) was done by correlation analysis.Results: Twenty-six subjects were included in the analysis. The movement task and tested arm showed significant effects (p < 0.05) on all kinematic parameters. Hand dominance resulted in significant effects on shoulder flexion/extension and curve efficiency. The level of upper limb function showed influences on curve efficiency and the factor age on median slope. Relations with the FMMA-UE revealed the strongest and significant correlation for curve efficiency (r = 0.75), followed by shoulder flexion/extension (r = 0.68), elbow flexion/extension (r = 0.53), and shoulder abduction/adduction (r = 0.49). Curve efficiency additionally correlated significantly with the arm subsection, focusing on synergistic control (r = 0.59).Conclusion: The kinematic parameters of the upper limb after stroke were influenced largely by the task. These results underpin the necessity to assess different relevant functional movements close to real-world conditions rather than relying solely on clinical measures.Study Registration: clinicaltrials.gov, identifier NCT03135093 and BASEC-ID 2016-02075.

Abstract 125: Automated External Defibrillator Shock Advisement Performance Among Multiple Human Electrocardiographic Rhythms and Devices

Background: Automated external defibrillators (AEDs) perform rhythm analysis in order to facilitate defibrillation. The effectiveness of AEDs is dependent on the accuracy of their rhythm classification, which includes differentiation of shockable rhythms from non-shockable rhythms Independent (i.e. non-industry) evaluation of the performance of AEDs against real-world ECG could lead to improvements in their performance. Objective: To evaluate the sensitivity and specificity characteristics of commercial AEDs with respect to quantitative properties of the ECG waveform in several rhythm presentations using real world ECG data. Methods: We conducted a prospective simulation study evaluating three commercially available AEDs from Defibtech, Phillips, and Zoll on the determination of ECG rhythm shockability. Performance was evaluated for 181 human ECG recordings (101 ventricular fibrillation-VF, 55 PEA, and 25 asystole) ranging widely in signal characteristics, obtained from the Pittsburgh site of the Resuscitation Outcomes Consortium. We used a commercially available digital-to-analog converter (National Instruments USB-6001) to inject the recordings into each AED through a direct lead-wire interface, recording shock advisement decisions in a best-out-of-three approach for each device/rhythm pairing. We calculated the sensitivity and specificity for discriminating VF and non-VF rhythms for each device and overall. VF signal characteristics were calculated, including peak frequency, median amplitude, and peak amplitude, and the VF quantitative waveform measures AMSA and median slope. Results: The 101 VF trials featured signals with mean peak frequency 10.02 Hz(IQR 4.80 Hz), mean AMSA 9.13(IQR 7.29), mean median slope 6.72 (IQR 3.66). The sensitivities were: Defibtech 99.0%; Philips 97.0%; Zoll 98.0%. The specificities were: Defibtech 98.7%; Philips 96.2%; Zoll 97.4%. Defibtech recorded 5 discordant advisements and Philips and Zoll recorded eight each. The overall sensitivity was 98.0%, and the specificity 97.4%. Conclusion: Evaluated against a wide variety of real-world signal presentations, commercial AEDs demonstrated a high degree of sensitivity and specificity for shockable ECG rhythms.

Uncertainty in Catchment Delineations as a Result of Digital Elevation Model Choice

Nine digital elevation model (DEM) datasets were used for separate delineations of the Nam Co, Tibet catchment and its subcatchments, and these delineated areas were compared using the highest resolution dataset, TanDEM-X 12 m, as a baseline. The mean delineated catchment area was within 0.1% percent of the baseline delineation, with a standard error of the mean (SEM) that was 0.13% of the baseline. In a comparison of 49 subcatchment areas, TanDEM-X and ALOS datasets delineated similar areas, followed closely by SRTM 30 m, then SRTM 90 m, ACE2, and ASTER GDEM1. ASTER GDEM2 was a noteworthy outlier, having the largest mean subcatchment area that was nearly three times that of the baseline mean. Correlation coefficients were calculated for subcatchment parameters, SEM, and each DEM’s subcatchment area error. SEM had a weak but significant negative correlation with the mean and median slope. ASTER GDEM1 and GDEM2 were the only datasets that showed any significant correlations with the subcatchment environment variables, though these correlations were also weak. The 30 m posting ASTER GDEMs performed worse against the baseline than the other 30 m and 90 m datasets, showing that posting alone does not determine how good a dataset is. Our results show general small errors for catchment delineations, though there is the possibility for large errors, particularly in the older ASTER and SRTM datasets.

The allometry of brain size in mammals

Why some animals have big brains and others do not has intrigued scholars for millennia. Yet, the taxonomic scope of brain size research is limited to a few mammal lineages. Here we present a brain size dataset compiled from the literature for 1552 species with representation from 28 extant taxonomic orders. The brain-body size allometry across all mammals is (Brain) = −1.26 (Body)0.75. This relationship shows strong phylogenetic signal as expected due to shared evolutionary histories. Slopes using median species values for each order, family, and genus, to ensure evolutionary independence, approximate ∼0.75 scaling. Why brain size scales to the ¾ power to body size across mammals is, to our knowledge, unknown. Slopes within taxonomic orders exhibiting smaller size ranges are often shallower than 0.75 and range from 0.24 to 0.81 with a median slope of 0.64. Published brain size data is lacking for the majority of extant mammals (>70% of species) with strong bias in representation from Primates, Carnivores, Perrisodactyla, and Australidelphian marsupials (orders Dasyuromorphia, Diprotodontia, Peramelemorphia). Several orders are particularly underrepresented. For example, brain size data are available for less than 20% of species in each of the following speciose lineages: Soricomorpha, Rodentia, Lagomorpha, Didelphimorphia, and Scandentia. Use of museum collections can decrease the current taxonomic bias in mammal brain size data and tests of hypothesis.

Field and laboratory evaluation of a high time resolution x-ray fluorescence instrument for determining the elemental composition of ambient aerosols

Measuring the chemical composition of airborne particulate matter (PM) can provide valuable information on the concentration of regulated toxic metals, support modelling approaches for source detection and assist in the identification and validation of abatement techniques. Undertaking these at a high time resolution (1 h or less) enables receptor modelling techniques to be more robustly linked to emission processes. This study describes a comprehensive laboratory and field evaluation of a high time resolution x-ray fluorescence (XRF) instrument (CES XACT 625) for a range of elements (As, Ba, Ca, Cd, Ce, Cl, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Pt, S, Sb, Se, Si, Sr, Ti, V and Zn) against alternative techniques: high time resolution mass measurements, high time resolution ion chromatography, aerosol mass spectrometry, and established filter-based, laboratory analysis using inductively coupled plasma mass spectrometry (ICP-MS). Laboratory evaluation was carried out using a novel mass-based calibration technique to independently assess the accuracy of the XRF against laboratory generated aerosols, which resulted in slopes that were not significantly different from unity. This demonstrated that generated particles can serve as an alternative calibration method for this instrument.The XACT was evaluated in three contrasting field deployments; a heavily trafficked roadside site (PM10 and PM2.5), an industrial location downwind of a nickel refinery (PM10) and an urban background location influenced by nearby industries and motorways (PM10). The XRF technique agreed well with the ICP-MS measurements of daily filter samples in all cases with a median R2 of 0.93 and a median slope of 1.07 for the elements As, Ba, Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, Se, Sr, Ti, V and Zn. Differences in the results were attributed to a combination of inlet location and sampling temperature, variable blank levels in filter paper and recovery rates from acid digestion. The XRF technique also agreed well with the other high time resolution measurements but showed a clear positive difference (slopes between 1.41 and 4.6), probably due to differences in the size selection methodology, volatility and water solubility of the PM in aerosol mass spectrometry (SO4) and ion chromatography (Ca, Cl, K and SO4), respectively.A novel filter analysis technique using the XACT showed promising initial results: filters analysed off-line with the XACT compared well to in situ XACT measurements with a median R2 of 0.96 and median slope of 1.07. The resulting range of slopes was comparable to slopes produced in the ICP-MS comparison. This technique provides an opportunity to use the XACT when it is not deployed in the field; thus expanding the potential use of this instrument in future studies.

Field and laboratory evaluation of a high time resolution x-ray fluorescence instrument for determining the elemental composition of ambient aerosols

Measuring the chemical composition of airborne particulate matter (PM) can provide valuable information on the concentration of regulated toxic metals and their sources and assist in the identification and validation of abatement techniques. Undertaking these at a high time resolution (1 hour or less) enables receptor modelling techniques to be more robustly linked to emission processes. This study describes a comprehensive laboratory and field evaluation of a high time resolution x-ray fluorescence (XRF) instrument (CES XACT 625) for a range of elements (As, Ba, Ca, Cd, Ce, Cl, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Pd, Pt, S, Sb, Se, Si, Sr, Ti, V, Zn) against alternative techniques: high time resolution mass measurements, high time resolution ion chromatography, aerosol mass spectrometry, and established filter-based, laboratory analysis using inductively coupled plasma mass spectrometry (ICP-MS). 1) Laboratory evaluation was carried out using a novel mass-based calibration technique to independently assess the accuracy of the XRF against laboratory generated aerosols, which resulted in slopes that were not significantly different from unity. This demonstrated that generated particles can serve as an alternative calibration method for this instrument. 2) The XACT was evaluated in three contrasting field deployments; a heavily trafficked roadside site (PM10 and PM2.5), an industrial location downwind of a nickel refinery (PM10) and an urban background location influenced by nearby industries and motorways (PM10). The XRF technique agreed well with the ICP-MS measurements of daily filter samples in all cases with a median R2 of 0.93 and a median slope of 1.07. Differences were likely due to recovery rates from the sample digestion as well as filter sampling artefacts and matrix effects in the XRF technique. The XRF technique also agreed well with the other high time resolution measurements but showed a significant positive bias (slopes between 1.41 and 4.6), probably due to differences in the size selection methodology, volatility and water solubility of the PM in aerosol mass spectrometry and ion chromatography, respectively. 3) A novel filter analysis technique using the XACT showed promising initial results: filters analysed off-line with the XACT compared well to in-situ XACT measurements with a median R2 of 0.96 and median slope of 1.07. The resulting range of slopes was comparable to slopes produced in the ICP-MS comparison. This technique provides an opportunity to use the XACT when it is not deployed in the field; thus expanding the potential use of this instrument in future studies.

Identification and characteristics of surge-type glaciers on Novaya Zemlya, Russian Arctic

We present a comprehensive new inventory of surge-type glaciers on the Novaya Zemlya archipelago, using high-resolution (up to 4 m) satellite imagery from 1976/77 (Hexagon), 1989 (Landsat TM), 2001 (Landsat ETM+) and 2006 (ASTER). A total of 692 glaciers and their forelands were observed for glaciological and geomorphological criteria indicative of glacier surging (e.g. looped moraines, heavy surface crevassing, surface potholes, thrust-block moraines, concertina eskers). This enabled the identification of 32 potential surge-type glaciers (compared with four previously identified) representing 4.6% of the total but 18% by glacier area. We assess the characteristics of surge-type glaciers. Surge-type glaciers are statistically different from non-surge-type glaciers in terms of their area, length, surface slope, minimum elevation, mid-range elevation and terminus type. They are typically long (median length 18.5 km), large (median area 106.8 km2) outlet glaciers, with relatively low overall surface slopes (median slope 1.7°) and tend to terminate in water (marine or lacustrine). They are predominantly directed towards and located in the more maritime western region of the Russian Arctic, and we suggest that surge occurrence might be related to large and complex catchment areas that receive increased delivery of precipitation from the Barents Sea.

Abstract P53: Four Electrocardiogram Waveform Measures Quantify Differences between Electrically Induced and Ischemically Induced Ventricular Fibrillation

Background: Analysis of the ECG has been shown to be useful to estimate the duration of VF in swine and the probability of successful defibrillation in animals and in patients. We use four methods to analyze the waveform: the logarithm of the absolute correlations (LAC): the median slope (MS): the angular velocity (AV): the amplitude spectrum area (AMSA). We hypothesized that VF produced by ischemia differs from electrically induced VF when analyzed by these measures. Methods: Electrical VF (EVF) was induced in 10 anesthetized and instrumented swine using electrical stimulation of the endocardium. Ischemic VF (IVF) was induced in 10 animals by occlusion of the LAD. After 7 min of VF, chest compressions were performed for 1 min followed by defibrillation. The response to shock was recorded as ROSC if a BP of 60 mmHg was present. LAC, MS, AV and AMSA were calculated on sequential 5 second epochs of VF for 7 minutes. VF was analyzed in segments from1 to 3 minutes, 3 to 4 minutes, and 4 to 7 minutes using the generalized estimating equations method in SAS. Probability of ROSC at first shock was also evaluated for IVF and EVF groups. Results: Differences in curves for all four measures were significant for minutes 1–3 and 4 –7. Curves are shown in Figure . No measure was significant for minute 3– 4. Probability of ROSC at first shock was 50% in the electric VF group and 10% in the ischemic VF group (p=0.039 for mean LAC prior to shock). Conclusions: EVF differs significantly from IVF for all measures both in early VF from 1–3 minutes and late VF from 4 –7 minute. All methods may be valid in predicting “down time” and choosing CPR first or Shock first.

MRD Kinetics Can Predict the Time to Relapse after Autologous Stem Cell Transplantation (SCT) in Chronic Lymphocytic Leukemia (CLL).

Introduction: Ongoing studies suggest, that myeloablative conditioning chemotherapie with autologous SCT is not a curative treatment option in high risk CLL patients. For this reason a method to predict progression free survival (pfs) in individual patients (pts) is desirable. Minimal residual disease (MRD) short after auto SCT in pts with CLL are known to be homogeneous low with increasing MRD level at later time points. Early MRD increase is associated with clinical risk factors and high risk for clinical relapse. Methods: To estimate time to progression in individual patients we studied MRD kinetics between 12 and 36 months after SCT (observation period) by quantitative ASO-primer IgH PCR and/or MRD flow in 37 poor risk CLL pts (5 % with mutated IgH, advanced Binet stage, high lymphocyte count). We postulated LOG-linear growth kinetics from 12 months after SCT until clinical relapse, which allowed calculation of time to predicted hematologic relapse (pHR) after auto SCT. All patients were in clinical remission before myeloablative conditioning regimen of TBI and high-dose cyclophosphamide following autologous SCT. 16/37 pts. with relapsed disease served as a control group whereas 21 pts in continuing clinical remission defined an observation group. LOG-MRD kinetics were described by a linear standard curve defined by 2 or more samples of patients in clinical remission more than 6 months (mos) apart. Significant MRD change was defined by a change of more than 0.5 orders of magnitude within the observation time. By this standard curve time to pHR, defined as a CLL level of 0.5 (i.e. 50% of all blood cells are CLL cells), was estimated. Results: 28 of all 37 pts. showed increasing, 4 stable and 5 decreasing MRD level during the observation period. In the control group of 16 pts. with clinical relapse, MRD level of one pt. remained stable until 36 mos after SCT, whereas 15 pts. showed significant MRD increase with a median slope of 0.093 (0.04 to 0.25) LOG-MRD level and a median time to pHR of 51 (27 – 92) mos compared to an observed median pfs of 39 (28 – 64) mos after SCT (ns). Median difference between pfs and time to pHR was 3.5 (5.4 – 60) mos. Only in 5 of 15 pts this difference exceeded 12 mos of whom all relapsed earlier than the estimated time point. In the observation group of 21 pts 9 (4 and 5 respectively) pts showed stable MRD level or significant MRD decrease. 12/21 pts showed significant MRD increase with a median slope of 0.08 (0.03 – 0.17) and a median time to pHR of 57 (28 – 160) mos. Only in 2/12 pts the clinical relapse preceded the pHR (0.4 and 7.4 mos) within the median clinical follow up period of 45 (25 – 69) mos. Conclusions: LOG-linear MRD models can characterize CLL increase from 12 momths after SCT: Increasing MRD kinetics predict the time to clinical relapse with acceptable accuracy in the majority of CLL pts, although this simple model tends to overestimate the time to relapse. Further improvement of the model, e.g. by calculating absolute CLL numbers and/or by more sophisticated statistical methods might minimize this error. Nevertheless, this overestimation might also be caused by biological reasons, e.g. clonal evolution or subclone selection.