A μ-biomimetic uncooled infrared psensor based on the infrared receptors of <em>Melanophila acuminata</em>

The pyrophilous beetle Melanophila acuminata possesses an organ sensitive to IR radiation. It employs a photomechanic detection principle: A liquid filled pressure chamber is heated by absorbing the radiation. The liquid expands and leads to the deflection of a mechanosensitive dendrite. In addition, a sophisticated compensation mechanism prevents the build-up of large pressures. In this work, a biomimetic IR sensor based on the IR receptors of Melanophila acuminata is developed by means of micro systems technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of the chambers leads to the heating and expansion of a liquid. The increasing pressure deflects a membrane which is part of a plate capacitor with a diameter of 500 μm and an electrode distance of 500 nm. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. A theoretical model is developed which is able to predict the modulation frequency dependent response. It allows to calculate the filter properties of the compensation mechanism which is verified by an experimental test. A simplified sensor without the compensation mechanism is manufactured to analyse the influence of several parameters on the sensor’s sensitivity. Finally, a solution for the fabrication of the μ-capacitor is presented. The large aspect ratio between electrode diameter and distance prevents to use a standard sacrificial layer process. The obtained capacitors pave the way to fabricate the complete full-featured sensor

Studien zur Totalsynthese von Myxovalargin und Darstellung einer Myxovalargin-Bibliothek

Myxovalargin, ein lineares Peptid bestehend aus 14 Aminosäuren (AS), welches am C-Terminus mit 3-Methylbutansäure beginnt und am N-Terminus mit dem Amin Agmitin endet, wurde im Jahr 1981 aus dem Bakterium Myxococcus fulvus Mx f65 isoliert und entstammte ursprünglich einer Bodenprobe der Kaiserstuhl-Gebirge. Neben der nicht-kanonischen AS β-Tyrosin beinhaltet die Struktur des Myxovalargins Dehydrovalin und (E)-Dehydroisoleucin, Aminosäuren, deren Synthesen einen zentralen Aspekt dieser Arbeit darstellen. Seine bakterizide Wirkung gegenüber GRAM-positiven Bakterien beruht auf der Inhibierung der Proteinbiosynthese und macht das Myxovalargin zu einem Vertreter der Peptid-Antibiotika. Während ein Großteil der Aminosäuresequenz durch einen hohen Valin-Anteil sehr unpolar ist, besitzt das Peptid durch die Agmatin- und Arginin-Seitenketten einen kationischen Charakter in wässriger Lösung. Hieraus ergeben sich Sekundärinteraktionen mit der Zellmenbran und voraussichtlich auch die gemessene, nicht unerhebliche cyctotoxische Wirkung. Der erste Teil dieser Promotionsschrift befasst sich mit den Studien zur Totalsynthese des Myxovalargins und damit, wie ein Dipeptid und ein Tetrapeptid synthetisiert werden können, welche jeweils einmal Dehydrovalin beinhalten. Es wird gezeigt, wie der Baustein 3-Nitrovalin verwendet werden kann, um Doppelbindungen in Peptiden durch die Eliminierung der NO2-Funktion aufzubauen, was durch Verseifungsbedingungen oder den Einsatz starker Aminbasen gelingt. Außerdem befasst sich der erste Teil damit wie die Synthese eines Tripeptides, welches Dehydroisoleucin beinhaltet mithilfe einer Kupfer-katalysierten Kreuzkupplung gelingt, welche ein Vinyliodid und ein primäres Amid als Substrate verwendet. Das Vinyliodid konnte in der erforderlichen (E)-Konfiguration durch eine Cuprat-Addition an einen 2-Butinester gewonnen werden. Der zweite Teil dieser Arbeit handelt von der Synthese von vereinfachten Myxovalargin-Derivaten, welche für einen Festphasen-Ansatz optimiert werden und zwar mit dem Ziel, Informationen zu den Struktur-Wirk-Beziehungen der Dehydro-ASs zu erhalten und auf diese Weise zu überprüfen, ob diese eine Rolle für die biologische Aktivität spielen. Folglich werden Bestrebungen unternommen, zunächst alle Dehydroaminosäuren durch Kanonische Aminosäuren zu ersetzen. Im Laufe dieser Synthesestudien wurden entsprechend erste Erkenntnisse gewonnen, um Myxovalargin und seine Derivate unter den Bedingungen der Festphasenpeptidsynthese zugänglich zu machen.Myxovalargin, a linear peptide containing 14 amino acids (AA) and starting with 3-methylbutanic acid at its N-terminus and terminated with the amine agmatine at its C-terminus, was isolated from Myxococcus fulvus Mx f65 in 1981 after extraction from a soil sample of the Kaiserstuhl mountains. Beside the non-canonical AA β-tyrosine the structure of Myxovalargin contains dehydrovaline and dehydro-isoleucine, amino acids, whose syntheses represent the core of this work. Its bactercidal activity against GRAM-positve bacteria stems from the inhibition of protein synthesis and makes Myxovalargin a member of the peptide antibiotics. The structure of Myxovalargin is dominated by valine making its sequence unpolar to a great extend. But the peptide also contains agmatine and arginine sidechains making the molecule cationic in aqueous solution, which is supposed to cause cytotoxicity by secondary interactions with cell membranes. The first part of this work covers efforts towards the total synthesis of Myxovalargin, especially strategies on how to synthesize a dipeptide and a tetrapeptide containing a single dehydro-valine, respectively. It will be demonstrated, how the building block 3-NO2-valine can be used to build up α,β-alkenes in peptides by elimination of the NO2-group, which is achieved by saponification or by the use of strong amine bases. Furthermore, the first part will cover the synthesis of an (E)-dehydroisoleucine containing tripeptide, that can be achieved via copper-mediated cross-coupling starting from a primary amide and a vinyl iodide, whose (E)-selective synthesis was possible via a syn-selective cuprate-addition to a 2-pentyne ester. The second part of this work will be about the syntheses of simplified Myxovalargin derivatives. which are optimized for a solid phase approach with the main goal of getting insights into the structure-activity relationship of dehydo AAs and thus verifying their importance to the biologic activity. Therefore progress towards derivatives free of dehydro AAs has been pursued, replacing those AAs through canonical ones. In the course of these studies first insights into synthesizing Myxovalargin and its derivatives under solid-phase conditions were gained

Tigers vs Lions: Towards Characterizing Solitary and Group User Behavior in MMORPG

The development of Internet technologies enables software developers to build virtual worlds such as Massively Multi-Player Online Role-Playing Games (MMORPGs). The population of such games shows super-linear growing tendency. It is estimated that the number of Internet users subscribed in MMORPGs is more than 22 million worldwide [1]. However, only little is known about the characteristics of traffic generated by such games as well as the behavior of their subscribers. In this paper, we characterize the traffic behavior of World of Warcraft, the most subscribed MMORPG in the world, by analyzing Internet traffic data sets collected from a European tier-1 ISP in two different time periods. We find that World of Warcraft is an influential application regarding the time spent by users (1.76 and 4.17 Hours/day on average in our measurement), while its traffic share is comparatively low (< 1%). In this respect, we look at the World of Warcraft subscriber’s gaming behavior by categorizing them into two different types of users (solitary users and group users) and compare these two groups in relation to the playing behavior (duration as the metric) and the in-game behavior (distance as the metric)

Betrayed by the nervous system: a comparison group study to investigate the 'unsafe world' model of selective mutism

The study presented in the following verifies some assumptions of the novel 'unsafe world' model of selective mutism (SM). According to this model, SM is a stress reaction to situations erroneously experienced via cognition without awareness as 'unsafe'. It assumes a high sensitivity to unsafety, whereby the nervous system triggers dissociation or freeze mode at relatively low thresholds. We examine whether there is a correlation between SM, sensory-processing sensitivity and dissociation. We compared a sample of 28 children and adolescents with SM (mean age 12.66 years; 18 females) to 33 controls without SM (mean age 12.45 years; 21 females). Both groups were compared using a medical history sheet, the 'Selective Mutism Questionnaire' (SMQ), a 'Checklist for Speaking Behaviour' (CheckS), the 'Highly Sensitive Person Scale' (HSPS), the 'Child Dissociative Checklist' (CDC), the 'Adolescent Dissociative Experience Scale' (A-DES) and the 'Social Phobia and Anxiety Inventory for Children' (SPAIK). Appropriate parametric and non-parametric tests were conducted to examine differences between groups. The results indicate that sensory-processing sensitivity was significantly higher in the group of children and adolescents with SM [X2(1) = 7.224, p = 0.0007; d = 1.092]. Furthermore, dissociative symptoms were more common in children and adolescents with SM than in controls [F(1, 33) = 13.004, p = 0.001; d = 0.986]. The results indicate that sensory-processing sensitivity and dissociation are important factors of SM that may hold important implications for the treatment. TRIAL REGISTRATION: This study is registered with the ClinicalTrials.gov number NCT04233905

Family Relationships in Selective Mutism-A Comparison Group Study of Children and Adolescents

Selective mutism (SM) mostly develops early in childhood and this has led to interest into whether there could be differences in relationships in families with SM compared to a control group without SM. Currently, there are merely few empirical studies examining family relationships in SM. A sample of 28 children and adolescents with SM was compared to 33 controls without SM. The groups were investigated using self-report questionnaires (Selective Mutism Questionnaire, Child-Parent Relationship Test—Child Version) for the assessment of SM and family relationships. Children with SM did not report a significantly different relationship to their mothers compared with the control group without SM. However, the scores in respect to the relationship to their fathers were significantly lower in cohesion, identification and autonomy compared with children without SM. Relationships in families with SM should be considered more in therapy

Participant Reactions to Two-Way Immersion (TWI) Programs

The purpose of this study was to elicit participant reactions to two-way immersion (TWI) programs in the United States of America. A large number of recent studies have focused on instructor views and perspectives of two-way immersion programs, so this study aimed to gain insight from students who are, or who have, participated in TWI programs throughout North America. One hundred fifty-one TWI schools throughout the United States were contacted and asked to participate in this study. Two similar surveys were developed, one for current TWI students, and another for former TWI students. Students from these two groups were asked to fill out a confidential online survey that addressed specific linguistic skills, abilities, and preferences, as well as connection to the cultures of the target language. Forty-eight percent of the survey respondents were native speakers of English, and the remaining 52% were non-native speakers of English. The number of respondents to the former student survey was so low that the data were inconclusive, and, therefore, will not be included in this study. Since the survey was conducted online, the data were stored in a comma-delimited format for further evaluation. The data were then tallied and analyzed for common themes

Awareness of forensic anthropology in Switzerland: a survey among forensic practitioners, police, and prosecutors

Forensic anthropology (FA) as a specialized discipline has been practised in multi-lingual Switzerland for over a decade. A variety of expertise regarding osteological assessments as well as facial image comparison (FIC) is provided by different centres. Nevertheless, information is lacking about the awareness of FA and its benefits for forensic investigations among forensic stakeholders. Therefore, a survey was sent to Swiss anthropologists (AN) and related professions (police officers, prosecutors, and forensic pathologists) to assess three main aspects: (1) the experience of working (biological/forensic) anthropologists within FA; (2) how FA is perceived by other professions within the legal system; and (3) identify gaps (if any) in understanding of FA with the aim to suggest avenues for improvement if necessary. The results show that awareness of FA varies by occupation and cantonal regions. In areas where close collaborations between forensic anthropologists (FAs) and other stakeholders have been formally established, be it with focus on osteological analyses or FIC, the awareness of FA competencies was superior to areas where this was not the case. An overwhelming majority of forensic actors expressed interest in continuing education related to the role of FA. These findings indicate that facilitation of communication and collaboration leads to improvement in the awareness of the competencies of FAs and their contribution to forensic investigations

MorDIFF: Recognition Vulnerability and Attack Detectability of Face Morphing Attacks Created by Diffusion Autoencoders

Investigating new methods of creating face morphing attacks is essential to foresee novel attacks and help mitigate them. Creating morphing attacks is commonly either performed on the image-level or on the representation-level. The representation-level morphing has been performed so far based on generative adversarial networks (GAN) where the encoded images are interpolated in the latent space to produce a morphed image based on the interpolated vector. Such a process was constrained by the limited reconstruction fidelity of GAN architectures. Recent advances in the diffusion autoencoder models have overcome the GAN limitations, leading to high reconstruction fidelity. This theoretically makes them a perfect candidate to perform representation-level face morphing. This work investigates using diffusion autoencoders to create face morphing attacks by comparing them to a wide range of image-level and representation-level morphs. Our vulnerability analyses on four state-of-the-art face recognition models have shown that such models are highly vulnerable to the created attacks, the MorDIFF, especially when compared to existing representation-level morphs. Detailed detectability analyses are also performed on the MorDIFF, showing that they are as challenging to detect as other morphing attacks created on the image- or representation-level. Data and morphing script are made public: https://github.com/naserdamer/MorDIFF.Comment: Accepted at the 11th International Workshop on Biometrics and Forensics 2023 (IWBF 2023