Image-guided neurosurgery allows surgeons to view their tools in relation to preoperatively acquired patient images and models. To continue using neuronavigation systems throughout operations, image ...registration between preoperative images typically magnetic resonance imaging (MRI) and intraoperative images (e.g., ultrasound) is common to account for brain shift (deformations of the brain during surgery). We implemented a method to estimate MRI-ultrasound registration errors, with the goal of enabling surgeons to quantitatively assess the performance of linear or nonlinear registrations. To the best of our knowledge, this is the first dense error estimating algorithm applied to multimodal image registrations. The algorithm is based on a previously proposed sliding-window convolutional neural network that operates on a voxelwise basis. To create training data where the true registration error is known, simulated ultrasound images were created from preoperative MRI images and artificially deformed. The model was evaluated on artificially deformed simulated ultrasound data and real ultrasound data with manually annotated landmark points. The model achieved a mean absolute error (MAE) of 0.977 ± 0.988 mm and a correlation of 0.8 ± 0.062 on the simulated ultrasound data, and an MAE of 2.24 ± 1.89 mm and a correlation of 0.246 on the real ultrasound data. We discuss concrete areas to improve the results on real ultrasound data. Our progress lays the foundation for future developments and ultimately implementation of clinical neuronavigation systems.
ABSTRACT
Blazars research is one of the hot topics of contemporary extragalactic astrophysics. That is because these sources are the most abundant type of extragalactic γ-ray sources and are ...suspected to play a central role in multimessenger astrophysics. We have used Swift$\_$xrtproc, a tool to carry out an accurate spectral and photometric analysis of the Swift-XRT data of all blazars observed by Swift at least 50 times between December 2004 and the end of 2020. We present a database of X-ray spectra, best-fit parameter values, count rates and flux estimations in several energy bands of over 31 000 X-ray observations and single snapshots of 65 blazars. The results of the X-ray analysis have been combined with other multifrequency archival data to assemble the broad-band Spectral Energy Distributions (SEDs) and the long-term light curves of all sources in the sample. Our study shows that large X-ray luminosity variability on different time-scales is present in all objects. Spectral changes are also frequently observed with a ‘harder-when-brighter’ or ‘softer-when-brighter’ behaviour depending on the SED type of the blazars. The peak energy of the synchrotron component (νpeak) in the SED of HBL blazars, estimated from the log-parabolic shape of their X-ray spectra, also exhibits very large changes in the same source, spanning a range of over two orders of magnitude in Mrk421 and Mrk501, the objects with the best data sets in our sample.
A minimal observable length is a common feature of theories that aim to merge quantum physics and gravity. Quantum mechanically, this concept is associated with a nonzero minimal uncertainty in ...position measurements, which is encoded in deformed commutation relations. In spite of increasing theoretical interest, the subject suffers from the complete lack of dedicated experiments and bounds to the deformation parameters have just been extrapolated from indirect measurements. As recently proposed, low-energy mechanical oscillators could allow to reveal the effect of a modified commutator. Here we analyze the free evolution of high-quality factor micro- and nano-oscillators, spanning a wide range of masses around the Planck mass mP (≈ 22 μg). The direct check against a model of deformed dynamics substantially lowers the previous limits on the parameters quantifying the commutator deformation.
Most cultivated apple cultivars are highly susceptible to fire blight, caused by
Erwinia amylovora
. However, differences in resistance levels are observed among cultivars and could be used in ...breeding. In this paper, we investigated the genetic basis of fire blight resistance of the cultivar ‘Enterprise’ and the advanced breeding selection X-6398. Genotyped pedigrees were used for validating and curating historic pedigree records. Various quantitative trait locus (QTL) discovery approaches were applied on the full-sib families ‘Gala’ × ‘Enterprise’ (GaEn) and X-6398 × X-6683 (IW) with the software FlexQTL™ and MapQTL®. The paternal lineage of ‘Enterprise’ was reconstructed and showed to include ‘Cox’s Orange Pippin’. The QTLs found varied with the software used. Using FlexQTL™, two were found on linkage groups (LGs) 7 and 13, favourable alleles inherited by Enterprise from ‘Cox’s Orange Pippin’ and ‘Golden Delicious’, respectively. The former was identical to the previously named
FB_F7
allele from ‘Fiesta’, while the latter is new and has been named
FB_13GD.
X-6398 had a QTL at the same position as
FB_F7
. Its favourable allele was new, originating from the unknown grandfather of X-4598, and was named
FB_7X-6398
. Using MapQTL® on GaEn,
FB_F7
was also identified. Performing the same analysis on the subset of offspring that carried the favourable allele of
FB_F7
, two putative QTLs on LG8 and on top of LG13 were identified, which showed interactions with
FB_F7
. Implication of the findings for breeding for fire blight-resistant apples is discussed. Single nucleotide polymorphism data on Enterprise and its ancestors are provided.
The self is the core of our mental life. Previous investigations have demonstrated a strong neural overlap between self‐related activity and resting state activity. This suggests that information ...about self‐relatedness is encoded in our brain's spontaneous activity. The exact neuronal mechanisms of such “rest‐self containment,” however, remain unclear. The present EEG study investigated temporal measures of resting state EEG to relate them to self‐consciousness. This was obtained with the self‐consciousness scale (SCS) which measures Private, Public, and Social dimensions of self. We demonstrate positive correlations between Private self‐consciousness and three temporal measures of resting state activity: scale‐free activity as indexed by the power‐law exponent (PLE), the auto‐correlation window (ACW), and modulation index (MI). Specifically, higher PLE, longer ACW, and stronger MI were related to higher degrees of Private self‐consciousness. Finally, conducting eLORETA for spatial tomography, we found significant correlation of Private self‐consciousness with activity in cortical midline structures such as the perigenual anterior cingulate cortex and posterior cingulate cortex. These results were reinforced with a data‐driven analysis; a machine learning algorithm accurately predicted an individual as having a “high” or “low” Private self‐consciousness score based on these measures of the brain's spatiotemporal structure. In conclusion, our results demonstrate that Private self‐consciousness is related to the temporal structure of resting state activity as featured by temporal nestedness (PLE), temporal continuity (ACW), and temporal integration (MI). Our results support the hypothesis that self‐related information is temporally contained in the brain's resting state. “Rest‐self containment” can thus be featured by a temporal signature.
Objective The study's objectives were to evaluate results and identify predictors of hospital and mid-term mortality after primary isolated aortic valve replacement; compare early and mid-term ...survival of patients aged more than 80 years or less than 80 years; and assess the effectiveness of the logistic European System for Cardiac Operative Risk Evaluation in predicting the risk for hospital mortality in octogenarians with a logistic European System for Cardiac Operative Risk Evaluation greater than 15% who are undergoing aortic valve replacement. Methods Data from 2256 patients undergoing primary isolated aortic valve replacement between January 2003 and December 2007 were prospectively collected in a Regional Registry (Regione Emilia Romagna Interventi Cardiochirurgia) and analyzed to estimate hospital and mid-term results. Results Overall hospital mortality was 2.2%. By multivariate analysis, New York Heart Association III and IV, Canadian Cardiovascular Society III and IV, pulmonary artery pressure greater than 60 mm Hg, dialysis, central neurologic dysfunction, and severe chronic obstructive pulmonary disease emerged as independent predictors of hospital mortality. At 3 years, the survival was 89.3%. The same predictors of hospital mortality plus ejection fraction of 30% to 50% and age more than 80 years emerged as independent risk factors for 3-year mortality. Compared with younger patients, octogenarians had a higher hospital mortality rate (3.72% vs 1.81%; P = . 0143) and a reduced 3-year survival (82.3% vs 91.3%; P < . 001). Three-year survival of octogenarians was comparable to the expected survival of an age- and gender-matched regional population ( P = . 157). The observed mortality rate in octogenarians with a logistic European System for Cardiac Operative Risk Evaluation greater than 15% (mean: 22.4%) was 7% ( P < . 001). Conclusions This study provides contemporary data on the characteristics and outcome of patients undergoing first-time isolated aortic valve replacement.
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