BioTwist - overcoming severe distortions in ridge-based biometrics for successful identication

Biometrics rely on a physical trait's permanence and stability over time, as well as its individuality, robustness and ease to be captured. Challenges arise when working with newborns or infants because of the tininess and fragility of an infant's features, their uncooperative nature and their rapid growth. The last of these is particularly relevant when one tries to verify an infant's identity based on captures of a biometric taken at an earlier age. Finding a physical trait that is feasible for infants is often referred to as the infant biometric problem. This thesis explores the quality aspect of adult fingermarks and the correlation between image quality and the mark’s usefulness for an ongoing forensic investigation, and researches various aspects of the “ballprint” as an infant biometric. The ballprint, the friction ridge skin area of the foot pad under the big toe, exhibits similar properties to fingerprint but the ball possesses larger physical structures and a greater number of features. We collected a longitudinal ballprint database from 54 infants within 3 days of birth, at two months old, at 6 months and at 2 years. It has been observed that the skin of a newborn's foot dries and cracks so the ridge lines are often not visible to the naked eye and an adult fingerprint scanner cannot capture them. This thesis presents the physiological discovery that the ballprint grows isotropically during infancy and can be well approximated by a linear function of the infant's age. Fingerprint technology developed for adult fingerprints can match ballprints if they are adjusted by a physical feature (the inter-ridge spacing) to be of a similar size to adult fingerprints. The growth in ballprint inter-ridge spacing mirrors infant growth in terms of length/height. When growth is compensated for by isotropic rescaling, impressive verification scores are achieved even for captures taken 22 months apart. The scores improve even further when low-quality prints are rejected; the removal of the bottom third improves the Equal Error Rate from 1-2% to 0%. In conclusion, this thesis demonstrates that the ballprint is a feasible solution to the infant biometric problem

Schreibförderung lernen: Lehramtsstudierende als Schreibcoach/innen - ein Lehrexperiment

Die hohe Diversität (schrift-)sprachlicher Fähigkeiten von Lernenden erfordert, Lehrkräfte differenziert auf den adäquaten Umgang damit vorzubereiten. Dazu wurde ein Seminar entwickelt, das ein sprachdidaktisches Konzept der halbstandardisierten, individuellen Rückmeldung zur Textqualität förderbedürftiger Schüler/innen vermittelt. In einem Lehrexperiment mit Lehramtsstudierenden des Faches Deutsch (BA vs. MA) wurde das Seminar durchgeführt und in einem Prä?Post-Follow up-Design evaluiert. Erste Ergebnisse zeigen, dass sich die Studierenden unabhängig von ihrer Studienerfahrung verbessern und die Nachhaltigkeit der Leistungssteigerung je nach Aufgabenformat variiert. 13.10.2017 | Marei Kotzerke, Moti Mathiebe & Joachim Grabowsk

Identification performance of evidential value estimation for ridge-based biometrics

Law enforcement agencies around the world use ridge-based biometrics, especially fingerprints, to fight crime. Fingermarks that are left at a crime scene and identified as potentially having evidential value (EV) in a court of law are recorded for further forensic analysis. Here, we test our evidential value algorithm (EVA) which uses image features trained on forensic expert decisions for 1428 fingermarks to produce an EV score for an image. First, we study the relationship between whether a fingermark is assessed as having EV, either by a human expert or by EVA, and its correct and confident identification by an automatic identification system. In particular, how often does an automatic system achieve identification when the mark is assessed as not having evidential value? We show that when the marks are captured by a mobile phone, correct and confident automatic matching occurs for 257 of the 1428. Of these, 236 were marked as having sufficient EV by experts and 242 by EVA thresholded on equal error rate. Second, we test four relatively challenging ridge-based biometric databases and show that EVA can be successfully applied to give an EV score to all images. Using EV score as an image quality value, we show that in all databases, thresholding on EV improves performance in closed set identification. Our results suggest an EVA application that filters fingermarks meeting a minimum EV score could aid forensic experts at the point of collection, or by flagging difficult latents objectively, or by pre-filtering specimens before submission to an AFIS

Mutations of the ret protooncogene in German multiple endocrine neoplasia families: Relation between genotype and phenotype.

It has been suggested that not only the position but also the nature of the mutations of the ret protooncogene strongly correlate with the clinical manifestation of the multiple endocrine neoplasm type 2 (MEN 2) syndrome. In particular, individuals with a Cys634-Arg substitution should have a greater risk of developing parathyroid disease. We, therefore, analyzed 94 unrelated families from Germany with inherited medullary thyroid carcinoma (MTC) for mutation of the ret protooncogene. In all but 1 of 59 families with MEN 2A, germline mutations in the extracellular domain of the ret protein were found. Some 81% of the MEN 2A mutations affected codon 634. Phenotype-genotype correlations suggested that the prevalence of pheochromocytoma and hyperparathyroidism is significantly higher in families with codon 634 mutations, but there was no correlation with the nature of the mutation. In all but 1 of 27 familial MTC (FMTC) families, mutations were detected in 1 of 4 cysteines in the extracellular domain of the ret protooncogene. Half of the FMTC mutations affected codon 634. Mutations outside of codon 634 occurred more often in FMTC families than in MEN 2A families. In all but 1 of 8 MEN 2B patients, de novo mutations in codon 918 were found. These data confirm the preferential localization of MEN 2-associated mutations and the correlation between disease phenotype and the position of the ret mutation, but there was no correlation between the occurrence of hyperparathyroidism or pheochromocytoma and the nature of the mutation

Epigenetic-Like Stimulation of Receptor Expression in SSTR2 Transfected HEK293 Cells as a New Therapeutic Strategy

Simple Summary Neuroendocrine tumors (NETs) expressing the somatostatin receptor subtype 2 (SSTR2) are promising targets for peptide receptor radionuclide therapy (PRRT) using the somatostatin analogue Lu-177-DOTATATE. Patients expressing low levels of SSTR2 do not benefit from PRRT. Therefore, an approach to increase the efficacy of PRRT utilizing the effects of 5-aza-2′-deoxycytidine (5-aza-dC) and valproic acid (VPA) on the SSTR2 expression levels is investigated. The cell lines HEKsst 2 and PC3 are incubated with 5-aza-dC and VPA in different combinations. The drug pretreatment of HEKsst 2 cells leads to increased Lu-177-DOTATATE uptake values (factor 28) and lower cell survival (factor 4) in comparison to unstimulated cells; in PC3 cells, the effects are negligible. Further, for the stimulated cell types, the maintenance of the intrinsic radiosensitivity in each cell type is confirmed by X-ray irradiation. The increased SSTR2 expression induced by VPA and 5-aza-dC stimulation in HEKsst 2 cells might improve treatment strategies for patients with NETs. Abstract The aim of the study was to increase the uptake of the SSTR2-targeted radioligand Lu-177-DOTATATE using the DNA methyltransferase inhibitor (DNMTi) 5-aza-2′-deoxycytidine (5-aza-dC) and the histone deacetylase inhibitor (HDACi) valproic acid (VPA). The HEKsst 2 and PC3 cells were incubated with variable concentrations of 5-aza-dC and VPA to investigate the uptake of Lu-177-DOTATATE. Cell survival, subsequent to external X-rays (0.6 or 1.2 Gy) and a 24 h incubation with 57.5 or 136 kBq/mL Lu-177-DOTATATE, was investigated via colony formation assay to examine the effect of the epidrugs. In the case of stimulated HEKsst 2 cells, the uptake of Lu-177-DOTATATE increased by a factor of 28 in comparison to the unstimulated cells. Further, stimulated HEKsst 2 cells demonstrated lower survival fractions (factor 4). The survival fractions of the PC3 cells remained almost unchanged. VPA and 5-aza-dC did not induce changes to the intrinsic radiosensitivity of the cells after X-ray irradiation. Clear stimulatory effects on HEKsst 2 cells were demonstrated by increased cell uptake of the radioligand and enhanced SST2 receptor quantity. In conclusion, the investigated approach is suitable to stimulate the somatostatin receptor expression and thus the uptake of Lu-177-DOTATATE, enabling a more efficient treatment for patients with poor response to peptide radionuclide therapy (PRRT)

Coordinated activation of VEGFR-1 and VEGFR-2 is a potent arteriogenic stimulus leading to enhancement of regional perfusion

Objective: The process of arteriogenesis is driven by various growth factors including vascular endothelial growth factor (VEGF)-A, which mediates its activity through VEGFR-2 (Flk-1/KDR) on endothelial cells and through VEGFR-1 (Flt-1) on endothelial cells and monocytes. The purpose of this study was to identify which of the VEGF receptors are involved in arteriogenesis in vivo. Methods: Collateral vessel growth was induced by femoral artery ligation in a mouse model of hindlimb ischemia. Following ligation, Balb/c mice were treated with different growth factors (VEGF-A, VEGF-E, PlGF-2, VEGF-E plus PlGF-2 or VEGF-A plus PlGF-2, activating either VEGFR-1, VEGFR-2, or both). After 1 week of treatment, hindlimb perfusion was assessed by perfusion scintigraphy using Tc-99m-MIBI. Results: The strongest improvement of regional perfusion was achieved by simultaneous activation of VEGFR-1 and VEGFR-2, using either VEGF-A or VEGF-A plus PlGF-2, with elevation of relative perfusion in the ischemic limbs from 0.61 to 0.83. The partial restoration in perfusion was associated with morphological changes typical for arteriogenesis. Moreover, specific inhibition of both VEGF-receptors using ZK 202650 resulted in a significant inhibition of arteriogenesis, indicating an active role of the VEGF system in compensatory arteriogenesis. Conclusion: The coordinated activation of both VEGFR-1 and VEGFR-2 represents a more potent arteriogenic stimulus compared to the isolated activation of either one of these two receptors. These data imply that the activation of both monocytes and endothelial cells is necessary to obtain a maximal VEGF-induced activation of arteriogenesi

A comparative study of machine learning methods for time-to-event survival data for radiomics risk modelling

Radiomics applies machine learning algorithms to quantitative imaging data to characterise the tumour phenotype and predict clinical outcome. For the development of radiomics risk models, a variety of different algorithms is available and it is not clear which one gives optimal results. Therefore, we assessed the performance of 11 machine learning algorithms combined with 12 feature selection methods by the concordance index (C-Index), to predict loco- regional tumour control (LRC) and overall survival for patients with head and neck squamous cell carcinoma. The considered algorithms are able to deal with continuous time-to-event survival data. Feature selection and model building were performed on a multicentre cohort (213 patients) and validated using an independent cohort (80 patients). We found several combinations of machine learning algorithms and feature selection methods which achieve similar results, e.g., MSR-RF: C-Index = 0.71 and BT-COX: C-Index = 0.70 in combination with Spearman feature selection. Using the best performing models, patients were stratified into groups of low and high risk of recurrence. Significant differences in LRC were obtained between both groups on the validation cohort. Based on the presented analysis, we identified a subset of algorithms which should be considered in future radiomics studies to develop stable and clinically relevant predictive models for time-to-event endpoints

Nuclear medicine procedures and the evaluation of male sexual organs: a short review

Sexuality consists of three aspects that are interrelated and inseparable, biological, physiological and social. The biological aspect considers the individual's capability to give and to receive pleasure. In consequence, it covers the functionality of the sexual organs and the physiology of human sexual response cycle. Diagnostic imaging modalities, such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) have been used to evaluate clinical disorders of the male reproductive system. PET and SPECT procedures basically involve the administration of a radiopharmaceutical that has a higher uptake in a specific tumor or tissue. The aim of this brief review is to present some radiopharmaceuticals that have been used in the clinical evaluation of the male sexual organs (testes, prostate, seminal vesicles, penis) related with male sexuality. This information could be useful in better understanding the male sexual response cycle, as well as the sexual disorders, when considering the male sexual organs and the pelvic floor. Moreover, the findings obtained with PET and SPECT imaging could help to evaluate the efficacy of clinical results of therapeutic procedures. In conclusion, the knowledge from these images could aid in better understanding the physiology of the different organs related with sexuality. Furthermore, they could be important tools to evaluate the physiological integrity of the involved organs, to improve clinical strategies and to accompany the patients under treatment