Photometric defocus observations of transiting extrasolar planets

We have carried out photometric follow-up observations of bright transiting extrasolar planets using the CbNUOJ 0.6m telescope. We have tested the possibility of obtaining high photometric precision by applying the telescope defocus technique allowing the use of several hundred seconds in exposure time for a single measurement. We demonstrate that this technique is capable of obtaining a root-mean-square scatter of order sub-millimagnitude over several hours for a V $\sim$ 10 host star typical for transiting planets detected from ground-based survey facilities. We compare our results with transit observations with the telescope operated in in-focus mode. High photometric precision is obtained due to the collection of a larger amount of photons resulting in a higher signal compared to other random and systematic noise sources. Accurate telescope tracking is likely to further contribute to lowering systematic noise by probing the same pixels on the CCD. Furthermore, a longer exposure time helps reducing the effect of scintillation noise which otherwise has a significant effect for small-aperture telescopes operated in in-focus mode. Finally we present the results of modelling four light-curves for which a root-mean-square scatter of 0.70 to 2.3 milli-magnitudes have been achieved.Comment: 12 pages, 11 figures, 5 tables. Submitted to Journal of Astronomy and Space Sciences (JASS

A review of complications and outcomes following vertebral column resection in adults

The correction of rigid spinal deformities in adult patients can require a three-column osteotomy (pedicle subtraction osteotomy [PSO] or vertebral column resection [VCR]) to obtain spinal balance. Unfortunately, the existing adult deformity literature frequently reports the outcomes and complications of these procedures together even though VCR is a more extensive procedure with potentially higher rates of complications. We sought to address this shortcoming and provide clinicians with an overview of the existing literature regarding VCR in adult patients. The goals of this review are: to determine the rate of overall and neurologic complications following VCR, the rate of complications with VCR compared to PSO, and the impact of VCR on clinical and radiographic outcomes. An electronic literature search was used to identify studies reporting outcomes or complications following VCR in adult patients. Raw data on patient demographics, case information, radiographic outcomes, complications and clinical outcomes were extracted. Data were pooled to report a rate of overall complications and neurologic complications. A pooled relative risk of complications following PSO vs. VCR was also calculated. Eleven retrospective studies (Level IV) met our inclusion criteria. The overall rate of complications was 69.2%. The reoperation rate was 9.6%. The rate of neurologic complications was 13.3% (range, 6.3% to 15.8%) with most cases being transient. The rate of permanent neurologic deficits was 2.0%. We found a significantly higher rate of all complications with VCR compared to PSO (relative risk, 1.36; 95% confidence interval, 1.24–1.49; p<0.001). All studies reporting clinical outcomes showed significant improvements in functional outcome postoperatively

Ball Trajectory Inference from Multi-Agent Sports Contexts Using Set Transformer and Hierarchical Bi-LSTM

As artificial intelligence spreads out to numerous fields, the application of AI to sports analytics is also in the spotlight. However, one of the major challenges is the difficulty of automated acquisition of continuous movement data during sports matches. In particular, it is a conundrum to reliably track a tiny ball on a wide soccer pitch with obstacles such as occlusion and imitations. Tackling the problem, this paper proposes an inference framework of ball trajectory from player trajectories as a cost-efficient alternative to ball tracking. We combine Set Transformers to get permutation-invariant and equivariant representations of the multi-agent contexts with a hierarchical architecture that intermediately predicts the player ball possession to support the final trajectory inference. Also, we introduce the reality loss term and postprocessing to secure the estimated trajectories to be physically realistic. The experimental results show that our model provides natural and accurate trajectories as well as admissible player ball possession at the same time. Lastly, we suggest several practical applications of our framework including missing trajectory imputation, semi-automated pass annotation, automated zoom-in for match broadcasting, and calculating possession-wise running performance metrics