Late on 2011 November 3, STEREO-A, STEREO-B, MESSENGER, and near-Earth spacecraft observed an energetic particle flux enhancement. Based on the analysis of in situ plasma and particle observations, ...their correlation with remote sensing observations, and an interplanetary transport model, we conclude that the particle increases observed at multiple locations had a common single-source active region and the energetic particles filled a very broad region around the Sun. The active region was located at the solar backside (as seen from Earth) and was the source of a large flare, a fast and wide coronal mass ejection, and an EIT wave, accompanied by type II and type III radio emission. In contrast to previous solar energetic particle events showing broad longitudinal spread, this event showed clear particle anisotropies at three widely separated observation points at 1 AU, suggesting direct particle injection close to the magnetic footpoint of each spacecraft, lasting for several hours. We discuss these observations and the possible scenarios explaining the extremely broad particle spread for this event.
Due to its Earth-like minimum mass of 1.27 ME and its close proximity to our solar system, Proxima Centauri b is one of the most interesting exoplanets for habitability studies. Its host star, ...Proxima Centauri, is however a strongly flaring star, which is expected to provide a very hostile environment for potentially habitable planets. We perform a habitability study of Proxima Centauri b assuming an Earth-like atmosphere under high stellar particle bombardment, with a focus on spectral transmission features. We employ our extensive model suite calculating energy spectra of stellar particles, their journey through the planetary magnetosphere, ionosphere, and atmosphere, ultimately providing planetary climate and spectral characteristics, as outlined in Herbst et al. Our results suggest that together with the incident stellar energy flux, high particle influxes can lead to efficient heating of the planet well into temperate climates, by limiting CH4 amounts, which would otherwise run into antigreenhouse for such planets around M stars. We identify some key spectral features relevant for future spectral observations: First, NO2 becomes the major absorber in the visible, which greatly impacts the Rayleigh slope. Second, H2O features can be masked by CH4 (near-infrared) and CO2 (mid- to far-infrared), making them nondetectable in transmission. Third, O3 is destroyed and instead HNO3 features become clearly visible in the mid- to far-infrared. Lastly, assuming a few percent of CO2 in the atmosphere, CO2 absorption at 5.3 m becomes significant (for flare and nonflare cases), strongly overlapping with a flare related NO feature in Earth's atmosphere.
Resective surgery is the treatment of choice for one-third of adult patients with focal, drug-resistant epilepsy. This procedure is associated with substantial clinical and cognitive risks. In ...clinical practice, there is no validated model for epilepsy surgery outcome prediction (ESOP). Meta-analyses on ESOP studies assessing prognostic factors report discrepancies in terms of study design. Our review aims to systematically investigate methodological and analytical aspects of studies predicting clinical and cognitive outcomes after temporal lobe epilepsy surgery. A systematic review of ESOP studies published between 2000 and 2022 from three databases (MEDLINE, Web of Science, and PsycINFO) was completed by following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. It yielded 4867 articles. Among them, 21 corresponded to our inclusion criteria and were therefore retained in the final review. The risk of bias was assessed using A Tool to Assess Risk of Bias and Applicability of Prediction Model Studies (PROBAST). Data extracted from the 21 studies were analyzed using narrative synthesis and descriptive statistics. Our findings show an increase in the use of multimodal datasets and machine learning analyses in recent ESOP studies, although regression remained the most frequently used approach. We also identified a more frequent use of network notions in recent ESOP studies. Nevertheless, several methodological issues were noted, such as small sample sizes, lack of information on the follow-up period, variability in seizure outcome, and the definition of neuropsychological postoperative change. Of 21 studies, only one provided a clinical tool to anticipate the cognitive outcome after epilepsy surgery. We conclude that methodological issues should be overcome before we move towards more complete models to better predict clinical and cognitive outcomes after epilepsy surgery. Recommendations for future studies to harness the possibilities of multimodal datasets and data fusion, are provided. A stronger bridge between fundamental and clinical research may result in developing accessible clinical tools.
Computation of the ionization and radiation dose in arbitrary (exo‐) planetary atmospheres due to energetic particles is recently becoming more important due to several reasons that are either ...correlated with the detection of trace gases for life on exoplanets or with computing dose rates at arbitrary altitudes in the Earth atmosphere. We previously presented Atmospheric Radiation Interaction Simulator, a new Geant4‐based code tailored specifically to enable parametric studies of radiation propagation through exoplanetary atmospheres (Banjac et al., 2019 https://doi.org/10.1029/2018JA026042). Therein, the calculation of ion‐electron pair production rates, which are a mandatory input for chemical and atmospheric modeling, has been presented and validated against Earth measurements and also other, similar, but solar‐system‐specific Geant4‐based codes (PLANETOCOSMICS). In addition to providing input for atmospheric modeling of exoplanets, with AtRIS we aim to directly characterize the habitability by calculating the absorbed dose. In this technical validation study, after showing a detailed analysis of the secondary particles contributing to the atmospheric radiation, we describe a feature of the code which makes direct parametric studies of the interrelation of incident radiation and the resulting absorbed dose throughout the atmosphere possible. In a validation case study configured using an atmospheric model obtained with NRLMSISE‐00 and a primary proton and helium GCR flux calculated using a recent improvement of the force‐field approach, we have compared simulation results with measurements obtained with the Flight Radiation Environment Detector (FRED). We show that Atmospheric Radiation Interaction Simulator (AtRIS) can reproduce the measured dose rate dependence on altitude.
Key Points
Atmospheric Radiation Interaction Simulator AtRIS, a new Geant4‐based code, has been designed to calculate absorbed and equivalent dose rate in a water phantom
A detailed investigation of the secondary particle populations and their contribution to the absorbed dose and dose equivalent is presented
We show that our simulation results are in good agreement with measurements made on a stratospheric balloon
We aimed to identify cognitive signatures (phenotypes) of patients suffering from mesial temporal lobe epilepsy (mTLE) with respect to their epilepsy lateralization (left or right), through the use ...of SVM (Support Vector Machine) and XGBoost (eXtreme Gradient Boosting) machine learning (ML) algorithms. Specifically, we explored the ability of the two algorithms to identify the most significant scores (features, in ML terms) that segregate the left from the right mTLE patients. We had two versions of our dataset which consisted of neuropsychological test scores: a “reduced and working” version (n = 46 patients) without any missing data, and another one “original” (n = 57) with missing data but useful for testing the robustness of results obtained with the working dataset. The emphasis was placed on a precautionary machine learning (ML) approach for classification, with reproducible and generalizable results. The effects of several clinical medical variables were also studied. We obtained excellent predictive classification performances (>75%) of left and right mTLE with both versions of the dataset. The most segregating features were four language and memory tests, with a remarkable stability close to 100%. Thus, these cognitive tests appear to be highly relevant for neuropsychological assessment of patients. Moreover, clinical variables such as structural asymmetry between hippocampal gyri, the age of patients and the number of anti-epileptic drugs, influenced the cognitive phenotype. This exploratory study represents an in-depth analysis of cognitive scores and allows observing interesting interactions between language and memory performance. We discuss implications of these findings in terms of clinical and theoretical applications and perspectives in the field of neuropsychology.
•We report an original, robust and generalizable method to assess cognitive phenotypes.•Cognitive data alone predict the lateralization of epilepsy.•Some cognitive tests are more relevant than others for the NPE of mTLE patients.•Clinical variables modulate the cognitive phenotype observed in patients.•Observed synergy between cognitive domains leads to new perspectives to comprehend cognition.
Context. Ground-level enhancements (GLEs) are solar energetic particle events that show a significant intensity increase at energies that can be measured by neutron monitors. The most recent GLE-like ...events were recorded on May 17, 2012 and January 6, 2014. They were also measured by sophisticated instrumentation in space such as PAMELA and the Electron Proton Helium INstrument (EPHIN) onboard SOHO. Since neutron monitors are only sensitive to protons above 400 MeV with maximum sensitivity at 1 to 2 GeV, the spectra of such weak GLE-like events (January 6, 2014) can only be measured by space instrumentation. Aims. We show that the SOHO/EPHIN is capable of measuring the solar energetic particle proton event spectra between 100 MeV and above 800 MeV. Methods. We performed a GEANT Monte Carlo simulation to determine the energy response function of EPHIN. Based on this calculation, we derived the corresponding proton energy spectra. The method was successfully validated against previous PAMELA measurements. Results. We present event spectra from EPHIN for May 17, 2012 and January 6, 2014. During the event in May 2012, protons were accelerated to energies above 700 MeV, while we found no significant increase for protons above 600 MeV during the event on January 6, 2014.
The EPHIN instrument (Electron Proton Helium INstrument) forms a part of the COSTEP experiment (COmprehensive SupraThermal and Energetic Particle Analyzer) within the CEPAC collaboration on board of ...the SOHO spacecraft (SOlar and Heliospheric Observatory). The EPHIN sensor is a stack of six solid-state detectors surrounded by an anticoincidence. It measures energy spectra of electrons in the range 250 keV to > 8.7 MeV, and hydrogen and helium isotopes in the range 4 MeV nuc to > 53 MeV nuc. In order to improve the isotopic resolution, the first two detectors have been segmented: 5 sectors form a ring enclosing a central segment. This does not only allow to correct the energy-losses for particles with different path-lengths in the detectors, but allows also an estimation of the arrival direction with respect to the sensor axis. For that purpose we developed a method that allows for inferring the angle of incidence and angular distribution for ions. Here we describe the method and apply it to the November, 3, 2011 event. Due to the lack of magnetic field measurements and the restricted view cone of 83°, it is not possible to derive a real pitch angle distribution during this event. However, we can show that the particle distribution is anisotropic for several hours with a symmetry axis that deviates by about 20° from the sensor axis.
The link between the preeclampsia development and dyslipidemia has been established. Even though lipid profile parameters have been intensively investigated in the pathology of preeclampsia, their ...accurate molecular mechanisms of action have not been fully decoded.
We aimed to identify the specifics of cholesterol metabolism in women affected by late-onset preeclampsia and single out potential biomarkers associated with late-onset syndrome.
Ninety pregnant women with a priori risk for preeclampsia development were monitored in four points during gestation and, based on the outcome of pregnancy, they were classified into the high-risk (70 women), and preeclampsia group (20 women). Cholesterol metabolic profiling was done using liquid chromatography-tandem mass spectrometry.
The only significant change in the preeclampsia group was an increase in lathosterol (P=0.001). The 1st-trimester lathosterol was higher in preeclampsia compared to the high-risk group (P=0.02). Further, in the preeclampsia group, positive correlations were found between desmosterol and β-sitosterol (ρ=0.474, P=0.03) in the 3rd trimester, desmosterol and campesterol changes between the 2nd and 1st (ρ=0.546, P=0.02), and the 3rd and 1st trimesters (ρ=0.754, P<0.001), as well as between the desmosterol and β-sitosterol differences between the 3rd and 1st trimesters (ρ=0.568, P=0.01). No similar correlations were found in the high-risk group.
Late-onset preeclampsia could be associated with an altered lipid profile. By studying the quantitative metabolic signatures of cholesterol, we might assume that both cholesterol synthesis and absorption are increased, i.e., there is an imbalance in the cholesterol homeostasis regulation in women affected by the disease.
Extracorporeal carbon dioxide removal (ECCO
R) permits reductions in alveolar ventilation requirements that the lungs would otherwise have to provide. This concept was applied to a case of ...hypercapnia refractory to high-level invasive mechanical ventilator support. We present a case of an 18-year-old man who developed post-pneumonectomy acute respiratory distress syndrome (ARDS) after resection of a mediastinal germ cell tumor involving the left lung hilum. Hypercapnia and hypoxemia persisted despite ventilator support even at traumatic levels. ECCO
R using a miniaturized system was instituted and provided effective carbon dioxide elimination. This facilitated establishment of lung-protective ventilator settings and lung function recovery. Extracorporeal lung support increasingly is being applied to treat ARDS. However, conventional extracorporeal membrane oxygenation (ECMO) generally involves using large cannulae capable of carrying high flow rates. A subset of patients with ARDS has mixed hypercapnia and hypoxemia despite high-level ventilator support. In the absence of profound hypoxemia, ECCO
R may be used to reduce ventilator support requirements to lung-protective levels, while avoiding risks associated with conventional ECMO.
Due to its Earth-like minimum mass of 1.27 M\(_{\text{E}}\) and its close proximity to our Solar system, Proxima Centauri b is one of the most interesting exoplanets for habitability studies. Its ...host star, Proxima Centauri, is however a strongly flaring star, which is expected to provide a very hostile environment for potentially habitable planets. We perform a habitability study of Proxima Centauri b assuming an Earth-like atmosphere under high stellar particle bombardment, with a focus on spectral transmission features. We employ our extensive model suite calculating energy spectra of stellar particles, their journey through the planetary magnetosphere, ionosphere, and atmosphere, ultimately providing planetary climate and spectral characteristics, as outlined in Herbst et al. (2019). Our results suggest that together with the incident stellar energy flux, high particle influxes can lead to efficient heating of the planet well into temperate climates, by limiting CH\(_4\) amounts, which would otherwise run into anti-greenhouse for such planets around M-stars. We identify some key spectral features relevant for future spectral observations: First, NO\(_2\) becomes the major absorber in the visible, which greatly impacts the Rayleigh slope. Second, H\(_2\)O features can be masked by CH\(_4\) (near infra-red) and CO\(_2\) (mid to far infra-red), making them non-detectable in transmission. Third, O\(_3\) is destroyed and instead HNO\(_3\) features become clearly visible in the mid to far infra-red. Lastly, assuming a few percent of CO\(_2\) in the atmosphere, CO\(_2\) absorption at 5.3 \(\mu\)m becomes significant (for flare and non-flare cases), strongly overlapping with a flare related NO feature in Earth's atmosphere.
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