Apoptosis and Medicine

This book looks at the latest research studies on apoptosis in medicine. It is divided into three sections for convenient and easy reading. The first section which comprises two chapters is an introduction of the subject of apoptosis to the uninitiated. The second section which comprises a single solitary chapter looks at apoptosis in normal physiology during bone resorption under mechanical stress. The third and the final section reviews apoptosis in a number of pathological conditions with an emphasis on cancer

Molecular regulation of mitochondrial dynamics by dynamin-related protein 1 (Drp1) and Bid in model systems of neuronal cell death

Mitochondrien sind Schlüsselorganelle in Signalwegen der neuronalen Apoptose und in Entwicklungs- und Alterungsprozessen der Zelle. Mitochondrien sind hoch dynamische Organelle, welche sich abhängig der physiologischen Bedingungen als lange miteinander verbundene Netzwerke oder als kleine, runde Organelle darstellen. Unter pathologischen Bedingungen und im neuronalen Zelltod ist die Regulation der Mitochondrienmorphologie deutlich verändert, wobei das Gleichgewicht der mitochondrialen Dynamik in Richtung Fragmentierung verschoben wird. Entsprechende Veränderungen der Mitochondrien treten z. B. im verzögerten neuronalen Zelltod nach Schlaganfall oder Schädel-Hirn-Trauma auf und vermehrt fragmentierte Mitochondrien sind auch in geschädigtem Hirngewebe bei alters-bedingten neurodegenerativen Erkrankungen, wie Morbus Alzheimer und Morbus Parkinson nachgewiesen worden. Im Rahmen dieser Arbeit wurde vor allem eine neuronale hippokampale Zelllinie (HT-22 Zellen) verwendet, um die Regulation und die Bedeutung der vermehrten Mitochondrienfragmentierung im oxidativen neuronalen Zelltod zu untersuchen. In diesen Zellen führt eine Behandlung mit Glutamat zu einem kontinuierlichen Abfall der intrazellulären Glutathionspiegel und induziert somit oxidativen Stress. Zusätzlich wurden primäre neuronale Zellkulturen und ein in vivo-Modell der zerebralen Ischämie eingesetzt, um die in HT-22 Zellen erhaltenen Ergebnisse zu bestätigen und auszubauen. Der erste Teil dieser Arbeit untersucht, ob verstärkte mitochondriale Fragmentierung den Glutamat-induzierten Zelltod begleitet. Die Ergebnisse zeigen eindeutig, dass Glutamat-induzierte Apoptose mit einer verstärkten Fragmentierung von Mitochondrien, dem Verlust von mitochondrialen Membranpotential und einer Umverteilung von fragmentierten Mitochondrien um den Zellkern verbunden ist. Weiter zeigen die hier dargestellten Ergebnisse eine Schlüsselrolle für das BH3-Protein Bid in der mitochondrialen Fragmentierung auf, die durch den oxidativen Stress ausgelöst wurde. Der zweite Teil der Arbeit untersucht die Rolle des Dynamin Proteins Drp1 im neuronalen Zelltod nach Glutamat-Schädigung in HT-22 Zellen und in primären kortikalen Neuronen. Um die Rolle von Drp1 im Glutamat-induzierten Zelltod nachzuweisen, wurde in dem hier angewendeten Modellsystem des oxidativen Stress zum ersten Mal hoch spezifische Drp1 Inhibitoren und Drp1 siRNA angewendet. Die Deletion von Drp1 durch siRNA oder durch den Drp1 Inhibitor zeigen, das mitochondriale Membranpotential aufrechterhalten werden kann und die mitochondriale Fragmentierung in HT-22 Zellen, als auch in primären Neuronen verhindert werden. Der Drp1 Inhibitor blockierte zudem den neuronalen Zelltod nach Sauerstoff-Glukose-Entzug in primären Neuronen und verringert auch signifikant das Infarktvolumen in einem Schlaganfallmodell in Mäusen. Diese Daten heben Drp1 als einen Schlüsselfaktor bei ischämisch- und Glutamat-induziertem neuronalen Zelltod hervor und identifizierten Drp1-abhängige mitochondriale Fragmentierung als eine mögliche therapeutischen Zielstruktur für die Therapie von akuten zerebrovaskulären Erkrankungen. Weitere Untersuchungen zu einer möglichen Wechselwirkung zwischen Bid und Drp1 im neuronalen Zelltod zeigten zudem erstmalig, dass offenbar beide Proteine nach oxidativem Stress zusammen an der Mitochondrienmembran agieren, um intrinsische Signalkaskaden der Apoptose zu induzieren. Die Hemmung eines der Proteine war ausreichend, um die mitochondriale Translokation bzw. die toxischen Effekte des Partners an den Mitochondrien zu hemmen und so den neuronalen Zelltod zu verhindern. Insgesamt konnte in dieser Arbeit zum ersten Mal gezeigt werden, dass Bid und Drp1 zusammen als Schlüsselregulatoren des mitochondrialen neuronalen Zelltodes in HT-22 Zellen agieren und das die Hemmung von Drp1 auch in primären Neuronen, und auch in einem Schlaganfallmodell in Mäusen eine protektive Wirkung vermittelt. Der Bid-vermittelte neuronale Zelltod umfasst Drp1-abhängige mitochondriale Fragmentierung, mitochondriale Umverteilung um den Zellkern, mitochondriale Membranschädigung und die Freisetzung von mitochondrialen Apoptose-Mediatoren wie AIF. Aus diesem Grund sind Bid und Drp1 vielversprechende therapeutische Zielstrukturen, die durch neuartige Inhibitor-Moleküle blockiert werden können, um mitochondriale Fragmentierung und Dysfunktion, als Kennzeichen des neuronalen Zelltodes bei akuten und chronischen neurodegenerativen Erkrankungen zu verhindern, in denen Glutamatschädigung bzw. oxidativer Stress zu den wesentlichen auslösenden Faktoren für die Nervenschädigung führen

Modeling and Simulation in Engineering

This book provides an open platform to establish and share knowledge developed by scholars, scientists, and engineers from all over the world, about various applications of the modeling and simulation in the design process of products, in various engineering fields. The book consists of 12 chapters arranged in two sections (3D Modeling and Virtual Prototyping), reflecting the multidimensionality of applications related to modeling and simulation. Some of the most recent modeling and simulation techniques, as well as some of the most accurate and sophisticated software in treating complex systems, are applied. All the original contributions in this book are jointed by the basic principle of a successful modeling and simulation process: as complex as necessary, and as simple as possible. The idea is to manipulate the simplifying assumptions in a way that reduces the complexity of the model (in order to make a real-time simulation), but without altering the precision of the results

Toward a further understanding of object feature binding: a cognitive neuroscience perspective.

The aim of this thesis is to lead to a further understanding of the neural mechanisms underlying object feature binding in the human brain. The focus is on information processing and integration in the visual system and visual shortterm memory. From a review of the literature it is clear that there are three major competing binding theories, however, none of these individually solves the binding problem satisfactorily. Thus the aim of this research is to conduct behavioural experimentation into object feature binding, paying particular attention to visual short-term memory. The behavioural experiment was designed and conducted using a within-subjects delayed responset ask comprising a battery of sixty-four composite objects each with three features and four dimensions in each of three conditions (spatial, temporal and spatio-temporal).Findings from the experiment,which focus on spatial and temporal aspects of object feature binding and feature proximity on binding errors, support the spatial theories on object feature binding, in addition we propose that temporal theories and convergence, through hierarchical feature analysis, are also involved. Because spatial properties have a dedicated processing neural stream, and temporal properties rely on limited capacity memory systems, memories for sequential information would likely be more difficult to accuratelyr ecall. Our study supports other studies which suggest that both spatial and temporal coherence to differing degrees,may be involved in object feature binding. Traditionally, these theories have purported to provide individual solutions, but this thesis proposes a novel unified theory of object feature binding in which hierarchical feature analysis, spatial attention and temporal synchrony each plays a role. It is further proposed that binding takes place in visual short-term memory through concerted and integrated information processing in distributed cortical areas. A cognitive model detailing this integrated proposal is given. Next, the cognitive model is used to inform the design and suggested implementation of a computational model which would be able to test the theory put forward in this thesis. In order to verify the model, future work is needed to implement the computational model.Thus it is argued that this doctoral thesis provides valuable experimental evidence concerning spatio-temporal aspects of the binding problem and as such is an additional building block in the quest for a solution to the object feature binding problem

Toward a further understanding of object feature binding : a cognitive neuroscience perspective

The aim of this thesis is to lead to a further understanding of the neural mechanisms underlying object feature binding in the human brain. The focus is on information processing and integration in the visual system and visual shortterm memory. From a review of the literature it is clear that there are three major competing binding theories, however, none of these individually solves the binding problem satisfactorily. Thus the aim of this research is to conduct behavioural experimentation into object feature binding, paying particular attention to visual short-term memory. The behavioural experiment was designed and conducted using a within-subjects delayed responset ask comprising a battery of sixty-four composite objects each with three features and four dimensions in each of three conditions (spatial, temporal and spatio-temporal).Findings from the experiment,which focus on spatial and temporal aspects of object feature binding and feature proximity on binding errors, support the spatial theories on object feature binding, in addition we propose that temporal theories and convergence, through hierarchical feature analysis, are also involved. Because spatial properties have a dedicated processing neural stream, and temporal properties rely on limited capacity memory systems, memories for sequential information would likely be more difficult to accuratelyr ecall. Our study supports other studies which suggest that both spatial and temporal coherence to differing degrees,may be involved in object feature binding. Traditionally, these theories have purported to provide individual solutions, but this thesis proposes a novel unified theory of object feature binding in which hierarchical feature analysis, spatial attention and temporal synchrony each plays a role. It is further proposed that binding takes place in visual short-term memory through concerted and integrated information processing in distributed cortical areas. A cognitive model detailing this integrated proposal is given. Next, the cognitive model is used to inform the design and suggested implementation of a computational model which would be able to test the theory put forward in this thesis. In order to verify the model, future work is needed to implement the computational model.Thus it is argued that this doctoral thesis provides valuable experimental evidence concerning spatio-temporal aspects of the binding problem and as such is an additional building block in the quest for a solution to the object feature binding problem.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Challenges for engineering students working with authentic complex problems

Engineers are important participants in solving societal, environmental and technical problems. However, due to an increasing complexity in relation to these problems new interdisciplinary competences are needed in engineering. Instead of students working with monodisciplinary problems, a situation where students work with authentic complex problems in interdisciplinary teams together with a company may scaffold development of new competences. The question is: What are the challenges for students structuring the work on authentic interdisciplinary problems? This study explores a three-day event where 7 students from Aalborg University (AAU) from four different faculties and one student from University College North Denmark (UCN), (6th-10th semester), worked in two groups at a large Danish company, solving authentic complex problems. The event was structured as a Hackathon where the students for three days worked with problem identification, problem analysis and finalizing with a pitch competition presenting their findings. During the event the students had workshops to support the work and they had the opportunity to use employees from the company as facilitators. It was an extracurricular activity during the summer holiday season. The methodology used for data collection was qualitative both in terms of observations and participants’ reflection reports. The students were observed during the whole event. Findings from this part of a larger study indicated, that students experience inability to transfer and transform project competences from their previous disciplinary experiences to an interdisciplinary setting

Exploring the practical use of a collaborative robot for academic purposes

This article presents a set of experiences related to the setup and exploration of potential educational uses of a collaborative robot (cobot). The basic principles that have guided the work carried out have been three. First and foremost, study of all the functionalities offered by the robot and exploration of its potential academic uses both in subjects focused on industrial robotics and in subjects of related disciplines (automation, communications, computer vision). Second, achieve the total integration of the cobot at the laboratory, seeking not only independent uses of it but also seeking for applications (laboratory practices) in which the cobot interacts with some of the other devices already existing at the laboratory (other industrial robots and a flexible manufacturing system). Third, reuse of some available components and minimization of the number and associated cost of required new components. The experiences, carried out following a project-based learning methodology under the framework of bachelor and master subjects and thesis, have focused on the integration of mechanical, electronic and programming aspects in new design solutions (end effector, cooperative workspace, artificial vision system integration) and case studies (advanced task programming, cybersecure communication, remote access). These experiences have consolidated the students' acquisition of skills in the transition to professional life by having the close collaboration of the university faculty with the experts of the robotics company.Postprint (published version