Overcoming Obstacles - Biomimetic Lessons from the Swarming Behavior of Artemia Franciscana

We investigated the formation of Artemia franciscana swarms of freshly hatched instar I nauplii larvae. Nauplii were released into light gradients but then interrupted by light-direction changes, small obstacles, or long barriers. All experiments were carried out horizontally. Each experiment used independent replicates. Freshly produced Artemia broods were harvested from independent incubators thus providing true replicate cohorts of Artemia subjected as replicates to the experimental treatments. We discovered that Artemia nauplii swarms can: 1. repeatedly react to non-obstructed light gradients that undergo repeated direction-changes and do so in a consistent way, 2. find their way to a light source within maze-like arrangements made from small transparent obstacles, 3. move as a swarm around extended transparent barriers, following a light gradient. This paper focuses on the recognition of whole-swarm behaviors, the description thereof and the recognition of differences in whole-swarm movements comparing non-obstructed swarming with swarms encountering obstacles. Investigations of the within-swarm behaviors of individual Artemia nauplii and their interactions with neighboring nauplii are in progress, e.g. in order to discover the underlying swarming algorithms and differences thereof comparing non-obstructed vs. obstructed pathways

Desert ants: is active locomotion a prerequisite for path integration?

Desert ants Cataglyphis fortis have been shown to be able to employ two mechanisms of distance estimation: exploiting both optic flow and proprioceptive information. This study aims at understanding possible interactions between the two possibly redundant mechanisms of distance estimation. We ask whether in Cataglyphis the obviously minor contribution of optic flow would increase or even take over completely if the ants were deprived of reliable proprioceptive information. In various experimental paradigms ants were subjected to passive horizontal displacements during which they perceived optic flow, but were prohibited from active locomotion. The results show that in desert ants active locomotion is essential for providing the ants' odometer and hence its path integrator with the necessary informatio

Passive Control of Attachment in Legged Space Robots

In the space environment the absence of gravity calls for constant safe attachment of any loose object, but the low-pressure conditions prohibit the use of glue-type adhesives. The attachment system of freely hunting spiders, e.g. Evarcha arcuata, employs van der Waals forces and mechanical interlocking. Furthermore, detachment is achieved passively and requires little force. Hence, the spider serves as a model for a versatile legged robot for space applications, e.g. on the outer surface of a space station. In this paper, we analyse the dry attachment systems ofE. arcuataand geckos as well as the kinematics of freely hunting spiders. We generalise the results of biological studies on spider locomotion and mobility, including the major movement and the position constraints set by the dry adhesion system. From these results, we define a simplified spider model and study the overall kinematics of the legs both in flight and in contact with the surface. The kinematic model, the data on spider gait characteristics and the adhesion constraints are implemented in a kinematic simulator. The simulator results confirm the principal functionality of our concept

Utilizing Multi-Level Concepts for Multi-Phase Modeling

In model-based systems engineering projects, engineers from multiple domains collaborate by establishing a common system model. Multi-level modeling is a technique that can be used to model the development from abstract ideas to concrete implementations. However, current multi-level modeling approaches are not adequate for processes with multiple modeling phases that might have to be rearranged later. In this paper, we introduce multi-phase modeling that utilizes concepts of multi-level modeling by considering a description of the expected phase ordering per domain. Constraints aware of this context can express that certain elements are only valid in specific phases without having to determine a concrete phase ordering for a particular model. This enables using multi-phase modeling in flexible workflows, adapting to changing requirements and the definition of access rules in domain notation. We show feasibility of this multi-phase modeling by applying it to multiple real-life systems engineering projects of the aerospace domain

Playful learning. Möglichkeiten, mit LEGO® den Schreibprozess zu unterstützen

Wie wäre es mit einer LEGO-Metapher? In diesem Artikel geht es darum, wie man mit LEGO-Steinen den Schreibprozess unterstützen kann. Die Autoren Louise Hoffmann und Tobias Seidl stellen eine Methode vor, bei der Studierende mithilfe von LEGO-Modellen an die Thematik des Verweisens in eigenen wissenschaftlichen Texten herangeführt werden können. Die Methode ist themenunabhängig und kann somit problemlos auf verschiedene fachliche Kontexte übertragen werden. Die Übung erfüllt zwei Funktionen: zum einen als Auflockerung des Workshops und zum anderen, um den Studierenden das Thema Intertextualität „begreifbarer“ zu machen. Die Methode folgt dem Modell des Experiential Learning Cycles von Kolb und das Arbeiten mit dem haptischen Material spielt eine große Rolle für den Erfolg der Übung. Der Artikel zeigt, dass beim Einsatz dieser Übung der Konstruktionsprozess nicht nur im Kopf der Teilnehmenden, sondern auch durch das Bauen von LEGO-Modellen auf dem Tisch stattfindet. (Herausgeber)How about a LEGO metaphor? This article is about how to use LEGO bricks to support the writing process. The authors Louise Hoffmann and Tobias Seidl present a method in which students can be introduced to the topic of referencing in their own academic texts with the help of LEGO models. The method is topic-independent and can thus be easily transferred to different subject contexts. The exercise serves two functions: on the one hand, to lighten up the workshop and, on the other hand, to make the topic of intertextuality more "comprehensible" to the students. The method follows Kolb\u27s Experiential Learning Cycles model and working with the haptic material plays a major role in the success of the exercise. The article shows that when using this exercise, the construction process takes place not only in the minds of the participants, but also by building LEGO models on the table. (Editor

11 Prinzipien zum gehirngerechten Lehren und Lernen

Als Lehrende sind wir auch gleichzeitig und lebenslang Lernende. Diesen Prozess wollen wir mit dem vorliegenden Arbeitsbuch unterstützen und Hochschullehrenden Anregungen und Ideen zum Umsetzen in die Hochschullehre geben. Gehirngerecht Lehren und Lernen bedeutet, die Funktionsweise unseres Gehirns bei der Gestaltung von Lernprozessen zu berücksichtigen. Die „11 Prinzipien zum gehirngerechten Lehren und Lernen“ sollen den einfachen Transfer von Erkenntnissen der Lehr-Lernforschung in Lehrveranstaltungen unterstützen

A Cadaveric Pilot Study

This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm × 15 mm full- thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds . PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation

Arthroscopic Fixation of Cell Free Polymer-Based Cartilage Implants with a Bioinspired Polymer Surface on the Hip Joint: A Cadaveric Pilot Study

This study investigates the adhesion capacity of a polyglycolic acid-(PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm x 15 mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds (P = 0.03752, P = 0.03078, P = 0.00512, P = 0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation