Exponential martingales and changes of measure for counting processes

We give sufficient criteria for the Dol\'eans-Dade exponential of a stochastic integral with respect to a counting process local martingale to be a true martingale. The criteria are adapted particularly to the case of counting processes and are sufficiently weak to be useful and verifiable, as we illustrate by several examples. In particular, the criteria allow for the construction of for example nonexplosive Hawkes processes as well as counting processes with stochastic intensities depending on diffusion processes

A comparative study of cranial, blunt trauma fractures as seen at medicolegal autopsy and by Computed Tomography

<p>Abstract</p> <p>Background</p> <p>Computed Tomography (CT) has become a widely used supplement to medico legal autopsies at several forensic institutes. Amongst other things, it has proven to be very valuable in visualising fractures of the cranium. Also CT scan data are being used to create head models for biomechanical trauma analysis by Finite Element Analysis. If CT scan data are to be used for creating individual head models for retrograde trauma analysis in the future we need to ascertain how well cranial fractures are captured by CT scan. The purpose of this study was to compare the diagnostic agreement between CT and autopsy regarding cranial fractures and especially the precision with which cranial fractures are recorded.</p> <p>Methods</p> <p>The autopsy fracture diagnosis was compared to the diagnosis of two CT readings (reconstructed with Multiplanar and Maximum Intensity Projection reconstructions) by registering the fractures on schematic drawings. The extent of the fractures was quantified by merging 3-dimensional datasets from both the autopsy as input by 3D digitizer tracing and CT scan.</p> <p>Results</p> <p>The results showed a good diagnostic agreement regarding fractures localised in the posterior fossa, while the fracture diagnosis in the medial and anterior fossa was difficult at the first CT scan reading. The fracture diagnosis improved during the second CT scan reading. Thus using two different CT reconstructions improved diagnosis in the medial fossa and at the impact points in the cranial vault. However, fracture diagnosis in the anterior and medial fossa and of hairline fractures in general still remained difficult.</p> <p>Conclusion</p> <p>The study showed that the forensically important fracture systems to a large extent were diagnosed on CT images using Multiplanar and Maximum Intensity Projection reconstructions. Difficulties remained in the minute diagnosis of hairline fractures. These inconsistencies need to be resolved in order to use CT scan data of victims for individual head modelling and trauma analysis.</p

Impact of sex on response to neoadjuvant chemotherapy in patients with bladder cancer

© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/.Objective: To assess the effect of patient's sex on response to neoadjuvant chemotherapy (NAC) in patients with clinically nonmetastatic muscle-invasive bladder cancer (MIBC). Methods: Complete pathologic response, defined as ypT0N0 at radical cystectomy, and downstaging were evaluated using sex-adjusted univariable and multivariable logistic regression modeling. We used interaction terms to account for age of menopause and smoking status. The association of sex with overall survival and cancer-specific survival was evaluated using Cox regression analyses. Results: A total of 1,031 patients were included in the analysis, 227 (22%) of whom were female. Female patients had a higher rate of extravesical disease extension (P = 0.01). After the administration of NAC, ypT stage was equally distributed between sexes (P = 0.39). On multivariable logistic regression analyses, there was no difference between the sexes or age of menopause with regards to ypT0N0 rates or downstaging (all P > 0.5). On Cox regression analyses, sex was associated with neither overall survival (hazard ratio 1.04, 95% confidence interval 0.75–1.45, P = 0.81) nor cancer-specific survival (hazard ratio 1.06, 95% confidence interval 0.71–1.58, P = 0.77). Conclusion: Our study generates the hypothesis that NAC equalizes the preoperative disparity in pathologic stage between males and females suggesting a possible differential response between sexes. This might be the explanation underlying the comparable survival outcomes between sexes despite females presenting with more advanced tumor stage.Peer reviewedFinal Accepted Versio