Objectives
This study surveyed the views of breast screening readers in the UK on how to incorporate Artificial Intelligence (AI) technology into breast screening mammography.
Methods
An online ...questionnaire was circulated to the UK breast screening readers. Questions included their degree of approval of four AI implementation scenarios: AI as triage, AI as a companion reader/reader aid, AI replacing one of the initial two readers, and AI replacing all readers. They were also asked to rank five AI representation options (discrete opinion; mammographic scoring; percentage score with 100% indicating malignancy; region of suspicion; heat map) and indicate which evidence they considered necessary to support the implementation of AI into their practice among six options offered.
Results
The survey had 87 nationally accredited respondents across the UK; 73 completed the survey in full. Respondents approved of AI replacing one of the initial two human readers and objected to AI replacing all human readers. Participants were divided on AI as triage and AI as a reader companion. A region of suspicion superimposed on the image was the preferred AI representation option. Most screen readers considered national guidelines (77%), studies using a nationally representative dataset (65%) and independent prospective studies (60%) as essential evidence. Participants’ free-text comments highlighted concerns and the need for additional validation.
Conclusions
Overall, screen readers supported the introduction of AI as a partial replacement of human readers and preferred a graphical indication of the suspected tumour area, with further evidence and national guidelines considered crucial prior to implementation.
Key points
Surveyed UK breast screening readers supported the introduction of AI.
Respondents approved of the replacement of one of the two initial readers.
Participants objected to the replacement of all human readers.
Respondents preferred the AI to graphically indicate the suspected tumour area.
Screen readers preferred forms of evidence based on national guidelines, national representative datasets, and independent prospective studies.
Tropical-tropopause-layer cirrus clouds and their radiative effects represent a major uncertainty in the evaluation of Earth’s energy budget. High-altitude aircraft offer an opportunity to provide ...observations at cirrus cloud altitudes, most commonly using in situ measurements of ice particle optical properties and composition. In particular, remote sensing of scattering properties and near-IR ice water absorption in the limb can provide unique insights into thin and sub-visible cirrus clouds. Here we present novel spectroscopic observations of path-averaged ice water absorptions on board NASA’s Global Hawk aircraft during the Airborne Tropical TRopopause Experiment (ATTREX), which took place in 2011, 2013, and 2014. The University of California Los Angeles and University of Heidelberg mini-differential optical absorption spectroscopy (mini-DOAS) instrument provided multi-angle limb-scanning observations of scattered solar radiation in the near-IR (900–1726 nm), allowing the identification of ice and liquid water, O2, CO2, and H2O. The VLIDORT-QS radiative transfer (RT) code was specifically developed for this study and used to simulate high-altitude limb observations for varied cloud scenarios. We performed a comprehensive sensitivity study, developing a fundamental understanding of airborne near-IR limb observations of cirrus clouds. We identified two general distinct cases: a linear regime for optically thin clouds, where the ice absorption is proportional to ice water content (IWC), and a regime for optically thick cirrus clouds, where ice absorption is in saturation and independent of IWC. Results also demonstrate how molecular oxygen absorption can be used to infer information on optical properties of ice particles in the second regime only, with minimal information for thin cirrus clouds. We also explored the feasibility of retrieving IWC from mini-DOAS path-averaged ice water absorption (SIWP) measurements. This innovative interpolation-based approach requires a small number of RT calculations per observation to determine the sensitivity of SIWP to IWC. Spectral retrievals were applied for a particularly interesting case during Science Flight 2 over Guam in February 2014, during which the aircraft flew in circles in the same general area for an extended period of time. Retrieved IWC results are consistent with independent in situ measurements from other instruments on board. The measurements of ice particle scattering and absorption at different azimuths relative to the sun and at different altitudes represent a unique opportunity to test our approach and to infer properties of the ice particles, together with information on cirrus cloud radiative transfer.
Abstract
Hydrodynamic forces on intertidal flats vary over a range of temporal and spatial scales. These spatiotemporal inhomogeneities have implications for intertidal flat morphodynamics and ...ecology. We determine whether storm events are capable of altering the long-term morphological evolution of intertidal flats, and unravel the contributions of tidal flow, wind-driven flow, waves, and water depth on inhomogeneities in bed level dynamics (bed level changes over ~days) across these areas. We complement decades of bed level measurements on eight intertidal flats in two estuaries in the Netherlands with an extensive 1-month field campaign on one of those flats. Across this intertidal flat, the hydrodynamics and morphodynamics of a storm event were captured, including the post-storm recovery. We show that individual events can persistently alter the morphological evolution of intertidal flats; magnitudes of some bed level changes are even comparable to years of continuous evolution. The morphological impacts of events are largely controlled by the relative timing of the forcing processes, and not solely by their magnitudes. Spatiotemporal variations in bed level dynamics of intertidal flats are driven by a combination of: (1) the inhomogeneous distributions of the hydrodynamic forcing processes (including the under-explored role of the wind); and (2) the linear proportionality between bed level dynamics and the local bed slope.
Signal intensity increases possibly suggestive of gadolinium retention have recently been reported on unenhanced T1-weighted images of the pediatric brain following multiple exposures to ...gadolinium-based MR contrast agents. Our aim was to determine whether T1 signal changes suggestive of gadolinium deposition occur in the brains of pediatric nonneurologic patients after multiple exposures to gadobenate dimeglumine.
Thirty-four nonneurologic patients (group 1; 17 males/17 females; mean age, 7.18 years) who received between 5 and 15 injections (mean, 7.8 injections) of 0.05 mmol/kg of gadobenate during a mean of 2.24 years were compared with 24 control patients (group 2; 16 males/8 females; mean age, 8.78 years) who had never received gadolinium-based contrast agents. Exposure to gadobenate was for diagnosis and therapy monitoring. Five blinded readers independently determined the signal intensity at ROIs in the dentate nucleus, globus pallidus, pons, and thalamus on unenhanced T1-weighted spin-echo images from both groups. Unpaired
tests were used to compare signal-intensity values and dentate nucleus-pons and globus pallidus-thalamus signal-intensity ratios between groups 1 and 2.
Mean signal-intensity values in the dentate nucleus, globus pallidus, pons, and thalamus of gadobenate-exposed patients ranged from 366.4 to 389.2, 360.5 to 392.9, 370.5 to 374.9, and 356.9 to 371.0, respectively. Corresponding values in gadolinium-based contrast agent-naïve subjects were not significantly different (
> .05). Similarly, no significant differences were noted by any reader for comparisons of the dentate nucleus-pons signal-intensity ratios. One reader noted a difference in the mean globus pallidus-thalamus signal-intensity ratios (1.06 ± 0.006 versus 1.02 ± 0.009,
= .002), but this reflected nonsignificantly higher T1 signal in the thalamus of control subjects. The number of exposures and the interval between the first and last exposures did not influence signal-intensity values.
Signal-intensity increases potentially indicative of gadolinium deposition are not seen in pediatric nonneurologic patients after multiple exposures to low-dose gadobenate.
We report measurements of CH4 (measured in situ by the Harvard University Picarro Cavity Ringdown Spectrometer (HUPCRS) and NOAA Unmanned Aircraft System Chromatograph for Atmospheric Trace Species ...(UCATS) instruments), O3 (measured in situ by the NOAA dual-beam ultraviolet (UV) photometer), NO2, BrO (remotely detected by spectroscopic UV–visible (UV–vis) limb observations; see the companion paper of Stutz et al., 2016), and of some key brominated source gases in whole-air samples of the Global Hawk Whole Air Sampler (GWAS) instrument within the subtropical lowermost stratosphere (LS) and the tropical upper troposphere (UT) and tropopause layer (TTL). The measurements were performed within the framework of the NASA-ATTREX (National Aeronautics and Space Administration – Airborne Tropical Tropopause Experiment) project from aboard the Global Hawk (GH) during six deployments over the eastern Pacific in early 2013. These measurements are compared with TOMCAT/SLIMCAT (Toulouse Off-line Model of Chemistry And Transport/Single Layer Isentropic Model of Chemistry And Transport) 3-D model simulations, aiming at improvements of our understanding of the bromine budget and photochemistry in the LS, UT, and TTL.Changes in local O3 (and NO2 and BrO) due to transport processes are separated from photochemical processes in intercomparisons of measured and modeled CH4 and O3. After excellent agreement is achieved among measured and simulated CH4 and O3, measured and modeled NO2 are found to closely agree with ≤ 15 ppt in the TTL (which is the detection limit) and within a typical range of 70 to 170 ppt in the subtropical LS during the daytime. Measured BrO ranges between 3 and 9 ppt in the subtropical LS. In the TTL, BrO reaches 0.5 ± 0.5 ppt at the bottom (150 hPa∕355 K∕14 km) and up to about 5 ppt at the top (70 hPa∕425 K∕18.5 km; see Fueglistaler et al., 2009 for the definition of the TTL used), in overall good agreement with the model simulations. Depending on the photochemical regime, the TOMCAT∕SLIMCAT simulations tend to slightly underpredict measured BrO for large BrO concentrations, i.e., in the upper TTL and LS. The measured BrO and modeled BrO ∕ Bryinorg ratio is further used to calculate inorganic bromine, Bryinorg. For the TTL (i.e., when CH4 ≥ 1790 ppb), Bryinorg is found to increase from a mean of 2.63 ± 1.04 ppt for potential temperatures (θ) in the range of 350–360 K to 5.11 ± 1.57 ppt for θ = 390 − 400 K, whereas in the subtropical LS (i.e., when CH4 ≤ 1790 ppb), it reaches 7.66 ± 2.95 ppt for θ in the range of 390–400 K. Finally, for the eastern Pacific (170–90° W), the TOMCAT/SLIMCAT simulations indicate a net loss of ozone of −0.3 ppbv day−1 at the base of the TTL (θ = 355 K) and a net production of +1.8 ppbv day−1 in the upper part (θ = 383 K).
Background: Female athletes participating in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate
than do male athletes.
Hypothesis: Prescreened female athletes ...with subsequent anterior cruciate ligament injury will demonstrate decreased neuromuscular control
and increased valgus joint loading, predicting anterior cruciate ligament injury risk.
Study Design: Cohort study; Level of evidence, 2.
Methods: There were 205 female athletes in the high-risk sports of soccer, basketball, and volleyball prospectively measured for neuromuscular
control using 3-dimensional kinematics (joint angles) and joint loads using kinetics (joint moments) during a jump-landing
task. Analysis of variance as well as linear and logistic regression were used to isolate predictors of risk in athletes who
subsequently ruptured the anterior cruciate ligament.
Results: Nine athletes had a confirmed anterior cruciate ligament rupture; these 9 had significantly different knee posture and loading
compared to the 196 who did not have anterior cruciate ligament rupture. Knee abduction angle ( P < .05) at landing was 8° greater in anterior cruciate ligamentâinjured than in uninjured athletes. Anterior cruciate ligamentâinjured
athletes had a 2.5 times greater knee abduction moment ( P < .001) and 20% higher ground reaction force ( P < .05), whereas stance time was 16% shorter; hence, increased motion, force, and moments occurred more quickly. Knee abduction
moment predicted anterior cruciate ligament injury status with 73% specificity and 78% sensitivity; dynamic valgus measures
showed a predictive r 2 of 0.88.
Conclusion: Knee motion and knee loading during a landing task are predictors of anterior cruciate ligament injury risk in female athletes.
Clinical Relevance: Female athletes with increased dynamic valgus and high abduction loads are at increased risk of anterior cruciate ligament
injury. The methods developed may be used to monitor neuromuscular control of the knee joint and may help develop simpler
measures of neuromuscular control that can be used to direct female athletes to more effective, targeted interventions.
Keywords:
neuromuscular control
dynamic valgus
knee joint load
anterior cruciate ligament (ACL) injury
injury prevention
gender differences
Abstract Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of ...clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities ( p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention.
The luminescence and scintillation properties of ZnO single crystals were studied by photoluminescence and X-ray-induced luminescence (XRIL) techniques. XRIL allowed a direct comparison to be made ...between the near-band emission (NBE) and trap emissions providing insight into the carrier recombination efficiency in the ZnO crystals. It also provided bulk luminescence measurements that were not affected by surface states. The origin of a green emission, the dominant trap emission in ZnO, was then investigated by gamma-induced positron spectroscopy (GIPS) - a unique defect spectroscopy method that enables positron lifetime measurements to be made for a sample without contributions from positron annihilation in the source materials. The measurements showed a single positron decay curve with a 175 ps lifetime component that was attributed to Zn vacancies passivated by hydrogen. Both oxygen vacancies and hydrogen-decorated Zn vacancies were suggested to contribute to the green emission. By combining scintillation measurements with XRIL, the fast scintillation in ZnO crystals was found to be strongly correlated with the ratio between the defect luminescence and NBE. This study reports the first application of GIPS to semiconductors, and it reveals the great benefits of the XRIL technique for the study of emission and scintillation properties of materials.
Riparian zones have been found to function as “sinks” for nitrate (NO3 -), the most common groundwater pollutant in the U. S., in many areas. The vast majority of riparian research, however, has ...focused on agricultural watersheds. There has been little analysis of riparian zones in urban watersheds, despite the fact that urban areas are important sources of NO3 - to nitrogen (N)-sensitive coastal waters in many locations. In this study, we measured stream incision, water table depths, and pools, production (mineralization, nitrification), and consumption (denitrification) of NO3 - in urban soils. Samples were taken from soil profiles (0−100 cm) of three forested urban and suburban zones and one forested reference riparian zone in the Baltimore, Maryland metropolitan area. Our objectives were to determine (1) if stream incision associated with urbanization results in lower riparian water tables, and (2) if pools, production, and consumption of NO3 - vary systematically with stream incision and riparian water table levels. Two of the three urban and suburban streams were more incised and all three had lower water tables in their riparian zones than the forested reference stream. Urban and suburban riparian zones had higher NO3 - pools and nitrification rates than the forested reference riparian zone, which was likely due to more aerobic soil profiles, lower levels of available soil carbon, and greater N enrichment in the urban and suburban sites. At all sites, denitrification potential decreased markedly with depth in the soil pro-file. Lower water tables in the urban and suburban riparian zones thus inhibit interaction of groundwater-borne NO3 - with near surface soils that have the highest denitrification potential. These results suggest that urban hydrologic factors can increase the production and reduce the consumption of NO3 - in riparian zones, reducing their ability to function as sinks for NO3 - in the landscape.
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