Advanced inversion Multi-term approach utilizing multiple a priori constraints is proposed. The approach is used as a base for the first unified algorithm GRASP that is applicable to diverse remote ...sensing observations and retrieving a variety of atmospheric properties. The utilization of GRASP for diverse remote sensing observations is demonstrated.
BACKGROUNDPediatric traumatic brain injury (TBI) and abusive head trauma (AHT) are leading causes of morbidity and mortality. Clinicians may not be aware of AHT at presentation to the emergency ...department (ED).
OBJECTIVEThe objective of this study was to determine which clinical features associated with head injury in children on initial presentation to the ED trauma bay predict 3 outcomes including clinically important TBI (CiTBI), classification as confirmed abuse by Child Protection Team (CPT), and poor neurologic status on hospital discharge.
PARTICIPANTS AND SETTINGInclusion for this study were children 3 years or younger, presenting to the ED with significant TBI. In addition, presentations where the mechanism of injury was not verifiable such as with falls, being struck by object, or no mechanism of injury reported by caregiver were included.
METHODSResearchers used 3 sources of information for this analysisa regional trauma registry, hospital records, and the CPT database. Clinical features included demographics, mechanisms of injury, physical, radiological findings, and CPT classification.
RESULTSOn pairwise analysis, seizures, apnea, and no mechanism of injury reported by caregiver were the only clinical features related to all 3 outcomes (P < 0.001). Rib fractures (relative risk RR, 3.3; P < 0.001), long bone fractures (RR, 3.1; P < 0.001), retinal hemorrhages (RR, 3.0; P < 0.001), seizures (RR, 3.6; P < 0.001), apnea (RR, 4.4; P < 0.001), and younger than 6 months (RR, 1.8; P < 0.001) were related to AHT. On multivariable logistic regression, no mechanism of injury reported by caregiver and seizures remained significantly related to CiTBI; seizures and retinal hemorrhage remained significantly related to classification as abuse by CPT, and no mechanism of injury by the caregiver, apnea, and seizures were significantly related to poor outcome on hospital discharge.
CONCLUSIONSNo mechanism of injury reported by the caregiver, seizures, and apnea at the time of presentation to the ED are important features associated with CiTBI, classification as AHT, and poor prognosis. In addition, younger age, retinal hemorrhage, rib, and long bone fractures were found to be important clinical features associated with AHT.
Proven by multiple theoretical and practical studies,
multi-angular spectral polarimetry is ideal for comprehensive retrieval of
properties of aerosols. Furthermore, a large number of advanced space
...polarimeters have been launched recently or planned to be deployed in the
coming few years (Dubovik et al.,
2019). Nevertheless, at present, practical utilization of aerosol products
from polarimetry is rather limited, due to the relatively small number of
polarimetric compared to photometric observations, as well as challenges in
making full use of the extensive information content available in these
complex observations. Indeed, while in recent years several new algorithms
have been developed to provide enhanced aerosol retrievals from satellite
polarimetry, the practical value of available aerosol products from
polarimeters yet remains to be proven. In this regard, this paper presents
the analysis of aerosol products obtained by the Generalized Retrieval of
Atmosphere and Surface Properties (GRASP) algorithm from POLDER/PARASOL
observations. After about a decade of development, GRASP has been adapted
for operational processing of polarimetric satellite observations and
several aerosol products from POLDER/PARASOL observations have been
released. These updated PARASOL/GRASP products are publicly available (e.g.,
http://www.icare.univ-lille.fr, last access: 16 October 2018, http://www.grasp-open.com/products/, last access: 28 March 2020); the dataset used in the current study is
registered under https://doi.org/10.5281/zenodo.3887265 (Chen
et al., 2020). The objective of this study is to comprehensively evaluate the GRASP aerosol
products obtained from POLDER/PARASOL observations. First, the validation of
the entire 2005–2013 archive was conducted by comparing to ground-based
Aerosol Robotic Network (AERONET) data. The subjects of the validation are
spectral aerosol optical depth (AOD), aerosol absorption optical depth
(AAOD) and single-scattering albedo (SSA) at six wavelengths, as well as
Ångström exponent (AE), fine-mode AOD (AODF) and coarse-mode AOD
(AODC) interpolated to the reference wavelength 550 nm. Second, an
inter-comparison of PARASOL/GRASP products with the PARASOL/Operational,
MODIS Dark Target (DT), Deep Blue (DB) and Multi-Angle Implementation of
Atmospheric Correction (MAIAC) aerosol products for the year 2008 was
performed. Over land both satellite data validations and inter-comparisons
were conducted separately for different surface types, discriminated by bins
of normalized difference vegetation index (NDVI): < 0.2, 0.2 ≤
and < 0.4, 0.4 ≤ and < 0.6, and ≥ 0.6. Three
PARASOL/GRASP products were analyzed: GRASP/HP (“High Precision”),
Optimized and Models. These different products are consistent but were
obtained using different assumptions in aerosol modeling with different
accuracies of atmospheric radiative transfer (RT) calculations.
Specifically, when using GRASP/HP or Optimized there is direct retrieval of
the aerosol size distribution and spectral complex index of refraction. When
using GRASP/Models, the aerosol is approximated by a mixture of several
prescribed aerosol components, each with their own fixed size distribution
and optical properties, and only the concentrations of those components are
retrieved. GRASP/HP employs the most accurate RT calculations, while
GRASP/Optimized and GRASP/Models are optimized to achieve the best trade-off
between accuracy and speed. In all these three options, the underlying
surface reflectance is retrieved simultaneously with the aerosol properties,
and the radiative transfer calculations are performed “online” during the
retrieval. All validation results obtained for the full archive of PARASOL/GRASP
products show solid quality of retrieved aerosol characteristics. The
GRASP/Models retrievals, however, provided the most solid AOD products, e.g.,
AOD (550 nm) is unbiased and has the highest correlation (R ∼ 0.92) and the highest fraction of retrievals (∼ 55.3 %)
satisfying the accuracy requirements of the Global Climate Observing System
(GCOS) when compared to AERONET observations. GRASP/HP and GRASP/Optimized
AOD products show a non-negligible positive bias (∼ 0.07) when
AOD is low (< 0.2). On the other hand, the detailed aerosol
microphysical characteristics (AE, AODF, AODC, SSA, etc.) provided by
GRASP/HP and GRASP/Optimized correlate generally better with AERONET than do
the results of GRASP/Models. Overall, GRASP/HP processing demonstrates the
high quality of microphysical characteristics retrieval versus AERONET.
Evidently, the GRASP/Models approach is more adapted for retrieval of total AOD,
while the detailed aerosol microphysical properties are limited when a
mixture of aerosol models with fixed optical properties are used. The results of a comparative analysis of PARASOL/GRASP and MODIS products
showed that, based on validation against AERONET, the PARASOL/GRASP AOD (550 nm) product is of similar and sometimes of higher quality compared to the
MODIS products. All AOD retrievals are more accurate and in good agreement
over ocean. Over land, especially over bright surfaces, the retrieval
quality degrades and the differences in total AOD products increase. The
detailed aerosol characteristics, such as AE, AODF and AODC from
PARASOL/GRASP, are generally more reliable, especially over land. The global
inter-comparisons of PARASOL/GRASP versus MODIS showed rather robust
agreement, though some patterns and tendencies were observed. Over ocean,
PARASOL/Models and MODIS/DT AOD agree well with the correlation coefficient
of 0.92. Over land, the correlation between PARASOL/Models and the different
MODIS products is lower, ranging from 0.76 to 0.85. There is no significant
global offset; though over bright surfaces MODIS products tend to show
higher values compared to PARASOL/Models when AOD is low and smaller values
for moderate and high AODs. Seasonal AOD means suggest that PARASOL/GRASP
products show more biomass burning aerosol loading in central Africa and
dust over the Taklamakan Desert, but less AOD in the northern Sahara. It is
noticeable also that the correlation for the data over AERONET sites are
somewhat higher, suggesting that the retrieval assumptions generally work
better over AERONET sites than over the rest of the globe. One of the
potential reasons may be that MODIS retrievals, in general, rely more on
AERONET climatology than GRASP retrievals. Overall, the analysis shows that the quality of AOD retrieval from
multi-angular polarimetric observations like POLDER is at least comparable
to that of single-viewing MODIS-like imagers. At the same time, the
multi-angular polarimetric observations provide more information on other
aerosol properties (e.g., spectral AODF, AODC, AE), as well as additional
parameters such as AAOD and SSA.
The Ocean and Land Color Instrument (OLCI) onboard the Copernicus Sentinel-3A satellite is a medium-resolution and multi-spectral push-broom imager acquiring radiance in 21 spectral bands covering ...from the visible to the far near-infrared. These measurements are primary dedicated to land & ocean color applications, but actually include also reliable information for atmospheric aerosol and surface brightness characterization. In the framework of the EUMETSAT funded study to support the Copernicus Program, we describe the retrieval of aerosol and surface properties from OLCI single-viewing multi-spectral Top-Of-Atmosphere (TOA) radiances based on the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) algorithm. The high potential of the OLCI/GRASP configuration stems from the attempt to retrieve both aerosol load and surface reflectance simultaneously using a globally consistent high-level approach. For example, both over land and ocean surfaces OLCI/GRASP uses 9 spectral channels (albeit with different weights), strictly the same prescribed aerosol models and globally the same a priori constraints (though with some differences for observations over land and ocean). Due to the lack of angular multi-viewing information, the directional properties of underlying surface are strongly constrained in the retrieval: over ocean the Fresnel reflection together with foam/whitecap albedo are exclusively computed using a priori wind speed; over land, the Bidirectional Reflectance Distribution Function (BRDF) is slightly adjusted from a priori values of climatological Ross-Li volumetric and geometric terms. Meanwhile, the isotropic reflectance is retrieved globally under mild spectral smoothness constraints. It should be noticed that OLCI/GRASP configuration employs innovative multi-pixel concept (Dubovik et al., 2011) that enhance retrieval by simultaneously inverting large group of pixels. The concept allows for benefiting from knowledge about natural variability of the retrieved parameters.
The obtained OLCI/GRASP products were validated with the Aerosol Robotic Network (AERONET) and Maritime Aerosol Network (MAN) and intercompared with the Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol and surface products. The overall performance is quite comparable to the community-referenced MODIS. Over ocean the OLCI/GRASP results are encouraging with 67% of the AOD (550 nm) satisfying the Global Climate Observing System (GCOS) requirement using AERONET coastal sites and 74% using MAN deep ocean measurements, and an AOD (550 nm) bias 0.01 with AERONET and nearly zero bias with MAN. Over land, 48% of OLCI/GRASP AOD (550 nm) satisfy the GCOS requirement and a bias within ±0.01 for total and AOD < 0.2. Key challenges are identified and discussed: adequate screening of cloud contaminations, retrieval of aerosol over bright surfaces and in the regions containing complex mixtures of aerosol.
•We retrieve aerosol and surface from OLCI/Sentinel-3A based on GRASP algorithm.•The directional BRDF are constrained using wind speed and climatology.•OLCI/GRASP products are validated with AERONET, MAN and intercompared with MODIS.
The Arm TrustZone is the de facto standard for hardware-backed Trusted Execution Environments (TEEs) on mobile devices, providing isolation for secure computations to be shielded from the normal ...world, and thus from the rest of the system. Most real-world TEEs are proprietary, difficult-to-inspect, and notoriously insecure: In the past years, it has been demonstrated over and over again that TEEs of millions of devices worldwide, and the Trusted Applications (TAs) they harbor, are often vulnerable to attacks such as control flow hijacking. Not only do we have to trust these TEEs to provide a secure environment for TAs such as keystore and Digital Rights Management (DRM), code running in the secure world provided by the Arm TrustZone also has full access to the memory of the regular operating system (OS). Since Thomas Roth first proposed a TrustZone-based rootkit in 2013, progress regarding such rootkits seems to have stalled in the offensive research community. The biggest challenge for TrustZone rootkits is that no interpretation of normal world memory is available in the secure world. Automated reverse engineering of kernel data structures at runtime is one way to implement rootkit functions. We present mechanisms to engineer the interpretation of Linux kernel memory for malicious subversion and the circumvention of basic protection mechanisms from the secure world. We provide a fully working proof-of-concept rootkit located in the Arm TrustZone to demonstrate the proposed mechanisms. We evaluate and show compatibility of the rootkit across different versions of the Linux kernel despite changing data structures. Our results highlight the feasibility of TrustZone rootkits that potentially survive kernel updates and raise awareness about the real danger of having to put trust into unvetted proprietary vendor code, which, as we show, can easily be abused.
A total of 110 patients with upper ureteral calculi was admitted to a prospective trial and randomly allocated to 2 groups: 1 group treated with in situ extracorporeal shock wave lithotripsy (ESWL) ...and 1 group treated with ureteral manipulation before ESWL. All patients had solitary upper ureteral calculi without urinary infection. The stones had to be smaller than 1 cm. and located more than 2 cm. lateral to the spine. ESWL was performed with the Dornier HM3 lithotriptor. One patient in the in situ ESWL group had to be treated twice because disintegration of the stone was insufficient after the initial treatment session. All other patients underwent only 1 treatment session. Because 16 patients were lost to followup, 94 were evaluable for the analysis of immediate and long-term results. For disintegration of the stones in situ ESWL needed significantly more shock waves (1,844 +/- 639 versus 1,297 +/- 473, p < 0.001) and a higher voltage (19.5 +/- 1.4 versus 18.7 +/- 0.9 kv., p < 0.001). There were no severe complications in either treatment group. At 3 months 44 of 46 patients (96%) after in situ ESWL and 45 of 48 (94%) after ureteral manipulation before ESWL were free of stones. In view of these results it is suggested that uncomplicated upper ureteral calculi (as defined previously) should be treated first with in situ ESWL, thus, avoiding an invasive procedure.
Summary Background Adjuvant endocrine therapy compromises bone health in patients with breast cancer, causing osteopenia, osteoporosis, and fractures. Antiresorptive treatments such as ...bisphosphonates prevent and counteract these side-effects. In this trial, we aimed to investigate the effects of the anti-RANK ligand antibody denosumab in postmenopausal, aromatase inhibitor-treated patients with early-stage hormone receptor-positive breast cancer. Methods In this prospective, double-blind, placebo-controlled, phase 3 trial, postmenopausal patients with early hormone receptor-positive breast cancer receiving treatment with aromatase inhibitors were randomly assigned in a 1:1 ratio to receive either denosumab 60 mg or placebo administered subcutaneously every 6 months in 58 trial centres in Austria and Sweden. Patients were assigned by an interactive voice response system. The randomisation schedule used a randomly permuted block design with block sizes 2 and 4, stratified by type of hospital regarding Hologic device for DXA scans, previous aromatase inhibitor use, and baseline bone mineral density. Patients, treating physicians, investigators, data managers, and all study personnel were masked to treatment allocation. The primary endpoint was time from randomisation to first clinical fracture, analysed by intention to treat. As an additional sensitivity analysis, we also analysed the primary endpoint on the per-protocol population. Patients were treated until the prespecified number of 247 first clinical fractures was reached. This trial is ongoing (patients are in follow-up) and is registered with the European Clinical Trials Database, number 2005-005275-15, and with ClinicalTrials.gov , number NCT00556374. Findings Between Dec 18, 2006, and July 22, 2013, 3425 eligible patients were enrolled into the trial, of whom 3420 were randomly assigned to receive denosumab 60 mg (n=1711) or placebo (n=1709) subcutaneously every 6 months. Compared with the placebo group, patients in the denosumab group had a significantly delayed time to first clinical fracture (hazard ratio HR 0·50 95% CI 0·39–0·65, p<0·0001). The overall lower number of fractures in the denosumab group (92) than in the placebo group (176) was similar in all patient subgroups, including in patients with a bone mineral density T-score of −1 or higher at baseline (n=1872, HR 0·44 95% CI 0·31–0·64, p<0·0001) and in those with a bone mineral density T-score of less than −1 already at baseline (n=1548, HR 0·57 95% CI 0·40–0·82, p=0·002). The patient incidence of adverse events in the safety analysis set (all patients who received at least one dose of study drug) did not differ between the denosumab group (1366 events, 80%) and the placebo group (1334 events, 79%), nor did the numbers of serious adverse events (521 vs 511 30% in each group). The main adverse events were arthralgia and other aromatase-inhibitor related symptoms; no additional toxicity from the study drug was reported. Despite proactive adjudication of every potential osteonecrosis of the jaw by an international expert panel, no cases of osteonecrosis of the jaw were reported. 93 patients (3% of the full analysis set) died during the study, of which one death (in the denosumab group) was thought to be related to the study drug. Interpretation Adjuvant denosumab 60 mg twice per year reduces the risk of clinical fractures in postmenopausal women with breast cancer receiving aromatase inhibitors, and can be administered without added toxicity. Since a main side-effect of adjuvant breast cancer treatment can be substantially reduced by the addition of denosumab, this treatment should be considered for clinical practice. Funding Amgen.
Photon-counting detector (PCD) CT could be useful to help address the typically high radiation doses of conventional energy-integrating detector (EID) CT of the lumbar spine.
The purpose of our study ...was to compare PCD CT and EID CT of the lumbar spine, both performed using tin filtration, in terms of radiation dose and image quality.
This study included a prospective sample of 39 patients (22 men, 17 women; mean age, 27.2 years) who underwent investigational PCD CT of the lumbar spine as part of a separate study and a retrospective sample of 39 patients (22 men, 17 women; mean age, 34.9 years) who underwent clinically indicated EID CT of the lumbar spine. In both groups, all examinations were performed using unenhanced technique with tin prefiltration between June 2022 and January 2023. Patients were matched between groups using age, sex, and BMI. A custom gaussian curve-fitting algorithm was used to automatically calculate image noise, SNR, and CNR for each examination, on the basis of all voxels within the image set. Three radiologists independently reviewed examinations to perform a subjective visual assessment of visualization of trabecular architecture, cortical bone, neuroforaminal content, paraspinal muscles, and intervertebral disk, as well as overall image quality, using a 4-point Likert scale (1 = poor, 4 = excellent). PCD CT and EID CT examinations were compared.
Mean CTDI
was 4.4 ± 1.0 (SD) mGy for PCD CT versus 11.1 ± 1.9 mGy for EID CT (
< .001). Mean size-specific dose estimate (SSDE) was 6.2 ± 1.0 (SD) mGy for PCD CT versus 14.2 ± 1.8 mGy for EID CT (
< .001). PCD CT and EID CT examinations were not significantly different in terms of image noise or SNR (both
> .05). PCD CT, in comparison with EID CT, showed significantly higher CNR (mean ± SD, 33.6 ± 3.3 vs 29.3 ± 4.1;
< .001). For all three readers, the median score for overall image quality was 4 (range, 3-4) for both PCD CT and EID CT. PCD CT and EID CT examinations showed no significant difference in terms of any qualitative measure for any reader (all
> .05).
PCD CT, in comparison with EID CT, yielded significantly lower radiation dose with preserved image quality.
The findings support expanded use of PCD CT for lumbar spine evaluation.
The aim of this study was to assess the diagnostic value of 3-dimensional dual-echo steady-state (DESS) magnetic resonance imaging (MRI) of the cervical spine at 7 T compared with 3 T in patients ...with cervical radiculopathy.
Patients diagnosed with cervical radiculopathy were prospectively recruited between March 2020 and January 2023 before undergoing surgical decompression and received 3-dimensional DESS imaging at 3 T and 7 T MRI. Cervical nerve root compression and the dimensions of the dorsal root ganglia were assessed by 2 radiologists independently. Signal intensity, visibility of nerve anatomy, diagnostic confidence, and image artifacts were evaluated with Likert scales. The degree of neuroforaminal stenosis was assessed on standard clinical 3 T scans. Statistics included the analysis of the diagnostic accuracy and interreader reliability. The Wilcoxon signed rank test was used to assess differences between the groups.
Forty-eight patients (mean age, 57 ± 12 years; 22 women) were included in the study with the highest prevalence of severe neuroforaminal stenosis observed at C6 (n = 68) followed by C7 (n = 43). Direct evaluation of nerve root compression showed significantly higher diagnostic confidence and visibility of cervical nerve rootlets, roots, and dorsal root ganglia on 7 T DESS than on 3 T DESS (diagnostic confidence: P = 0.01, visibility: P < 0.01). Assessment of nerve root compression using 7 T DESS allowed more sensitive grading than standard clinical MRI ( P < 0.01) and improved the performance in predicting sensory or motor dysfunction (area under the curve combined: 0.87).
7 T DESS imaging allows direct assessment of cervical nerve root compression in patients with radiculopathy, with a better prediction of sensory or motor dysfunction than standard clinical MRI. Diagnostic confidence and image quality of 7 T DESS were superior to 3 T DESS.
PDF
