This study investigated dual-task processing in younger and older adults using a psychological refractory period procedure. The first task was to name the color framing a picture; the second task was to either press a button or tilt their body in the direction of the tilt of the picture. In the body-tilt condition, electromyography was used to determine the reaction time. The stimulus-onset asynchrony (SOA) between the onset of the color and tilting of the picture varied from 50 to 1000 ms. In contrast with the response selection bottleneck model, which claims that processing of a second task cannot be completed until the first task is finished, the mode of response for the two tasks directly impacted the ability to avoid the bottleneck. In the body-tilt condition the increase in reaction time to the second task with decreasing SOA was less than in the button press condition, suggesting that processing of the second task could begin before processing of the first task was completed. This was true for both younger and older adults. Contrary to previous findings that older adults cannot engage in simultaneous processing of two tasks, evidence was found that older adults, like younger adults, could bypass the cognitive bottleneck if the second task has a reflexive component.

I investigated parasitic infection and immunocompetence in populations of introduced bird species in New Zealand (NZ) that had experienced a range of population bottlenecks (11-808 individuals), and compared these parameters to non-bottlenecked conspecifics in the United Kingdom (UK). My aims were two-fold; firstly to assess if population bottlenecks are linked to increased parasite loads and/or decreased immunocompetence, and secondly, to assess at what severity of bottleneck these effects become evident. I found that ectoparasite load (chewing lice, Order: Phthiraptera, Sub-Orders: Amblycera & Ischnocera) was significantly higher in the more severely bottlenecked species in NZ than in the UK, whilst this difference became non-significant at more moderate bottlenecks. The difference was mainly driven by the Sub-Order Amblycera. The prevalence of avian malaria (Plasmodium spp.) was significantly negatively correlated to bottleneck size within NZ, after controlling for body mass. Total leucocyte and differential lymphocyte counts were elevated in the less bottlenecked species that were infected with malaria, whilst the populations at the more severe end of the bottleneck spectrum did not exhibit such a response. Furthermore, heterophil/lymphocyte (HL) ratio (a parameter used as an indicator of environmental and/or immunological stress), was significantly raised in the more bottlenecked species when compared to their UK counterparts, and this difference was correlated with the size of the bottleneck. Immunocompetence was further assessed by the experimental challenge of six introduced birds species in NZ with the mitogen phytohaemagglutinin (PHA). Immune response to PHA was significantly correlated to bottleneck size, but in the opposite direction to that predicted; immune response was greater in the more bottlenecked species. However, this may be an indication of increased investment in immunity, due to increased parasite and pathogen pressure or differential investment in varying components of the immune system. Finally, the immune response to PHA was compared in nestlings of two species that had experienced very different bottlenecks (70 vs. 653). After controlling for ectoparasitic infestation, I found no difference between the two species; however, this finding may be confounded by interspecific competition. Overall, my findings suggest that more severe population bottlenecks may result in increased susceptibility to pathogens, and impact on the immune system. This has a number of implications for the development of conservation protocols, and future avenues of research are suggested.

This Bachelor thesis reviews the concept of non-innovative faction groups in digital games and the cause and effect of such systems. The paper goes into detail on what diffractions are available to developers when creating a faction driven game. It also illuminates the need to be aware of consequences of small details in a big picture. It will outline what types of faction systems in games that can be argued to be outdated and repeated, and why such a thing can prove detrimental to the development of future games and to developers. The necessity of these design choices of factions will be outlined through design fundamentals regarding games, as well as through research of strategy games and how they employ factions through their semi-historical inspiration sources. The functionality of those design choices will be considered through heuristic evaluation and then determined what key components are necessary to the overall gameplay of such games. Gamemaker will also be discussed as a means of creating these systems in games and the limitations and opportunities presented by using that programming software.

MHC glycoproteins are an essential part of adaptive immunity and may also play a role in mate choice. In addition, MHC genes are the most variable of all known genes. For these reasons, they have been intensively studied for several last decades. However, research is complicated due to extreme variability and frequent duplications. The Eurasian beaver seems to serve as an interesting model. It underwent a dramatic bottleneck culminating in the end of 19th century, when only about 1,200 individuals survived in several isolated relic populations. Thanks to numerous reintroductions, beavers of various origin meet in newly established populations. However, knowledge of beaver MHC was very limited. Only a single MHC gene has been investigated in a detail, and some relic populations were not sampled. Utilising additional relic populations and additional MHC locus, I verified a significant reduction of the variability of beaver MHC genes and also found signs of selection in the past. Then I sequenced MHC loci in two newly formed populations. I confirmed the ongoing selection by the disruption of cytonuclear equilibrium and the advantage of divergent alleles. We therefore can have a unique insight into the several periods of the history of beaver populations: In the past, MHC diversity was shaped by a...

This diploma thesis is based on creation of a simulation model of the conveyor bridge between a paint-shop and an assembly hall in the company Škoda Auto, a.s. in Mladá Boleslav. The model was created in the simulation software Plant Simulation on the grounds of an existing model in simulation software SimPro. Analysis of the existing model in software SimPro as well as a system analysis of conveyors used in the respected production section is carried out in the thesis. Results of simulation experiments accomplished with the newly created model follow. These experiments verify the throughput rate for various production programmes. On the grounds of these results a bottleneck analysis of the conveyor system is carried out and arrangements leading to increase in its throughput rate are made.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13020号 / 論農博第2830号 / 新制||農||1042(附属図書館) / 学位論文||H28||N4966(農学部図書室) / 32948 / (主査)教授 祝前 博明, 教授 今井 裕, 教授 廣岡 博之 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Efficiently and accurately estimating bandwidths in packet networks is a problem that has intrigued researchers for years. There is no simple manner for estimating bandwidths in IPv4 networks that is accurate, efficient, flexible, and suitable for a variety of applications. Many of the available estimation techniques suffer from inherent flaws such as inaccuracy due to simple assumptions about the network or an overall high complexity that makes it inappropriate in all but a few highly specific situations. The next generation Internet Protocol, IP version 6, has the functionality necessary to implement feedback mechanisms to assist in accurate bandwidth estimations. This thesis proposes a timestamp hop-by-hop option for IPv6 and then applies this option to create a new bandwidth estimation technique. Instead of passive observations, the network infrastructure actively assists in bandwidth measurements resulting in a bandwidth estimation technique that is accurate, efficient, flexible, and suitable for many different applications and scenarios. Both analytical and simulation analysis show that the IPv6 bandwidth estimation technique outperforms a comparable IPv4 estimation method.

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Zahlreiche Studien belegen, dass Menschen Schwierigkeiten bei der simultanen Ausführung von 2 Aufgaben haben. Diese Schwierigkeiten sind durch zusätzliche Leistungskosten in Doppelaufgabensituationen im Vergleich zu Einzelaufgabensituationen gekennzeichnet (d.h. Doppelaufgabenkosten). Allerdings konnten jüngere Studien eine deutliche Reduktion der Doppelaufgabenkosten am Ende von Übung zeigen. Der Befund von Doppelaufgabenkosten am Beginn und die deutliche Reduktion davon am Ende der Übung indiziert, dass diese Reduktion durch spezifische Lernmechanismen geleistet wird. Obwohl sich frühere Studien bereits mit diesen Mechanismen befassen, bleiben die genauen Mechanismen der Reduktion der Doppelaufgabenkosten durch Übung unbekannt. Das Ziel von vier Studien der vorliegenden Arbeit ist die Spezifizierung dieser Mechanismen durch die Anwendung einer Doppelaufgabensituation mit einer visuellen und einer auditiven Teilaufgabe (Schumacher et al., 2001). Untersuchungen zu Lernmechanismen innerhalb der Teilaufgaben zielten auf die genaue Lokalisation von Verkürzungen der Verarbeitungszeit in diesen Aufgaben während der Übung. Erstmalig konnte ich zeigen, dass die Verkürzung der Aufgabenverarbeitung in Doppelaufgabensituationen vor allem durch eine verkürzte Antwortauswahlstufe erfolgt. Demgegenüber haben Untersuchungen zu Lernmechanismen zwischen den Teilaufgaben auf den Erwerb von Fertigkeiten der Aufgabenkoordination gezielt. Hier habe ich Nachweise erbracht, dass diese Fertigkeiten während der Übung von Doppelaufgaben erwerbbar sind, aber dass kein Erwerb während Einzelaufgabenübung erfolgt. Weiterhin habe ich gezeigt, dass diese Fertigkeiten in alternative Doppelaufgabensituationen transferierbar sind. Allerdings gibt es keinen Nachweis für den Fertigkeitstransfer in Aufgabenwechsel- und Attentional-Blink-Situationen. Um das Ergebnis von Lernmechanismen weiter zu spezifizieren, habe ich gezeigt, dass die Doppelaufgabenleistung in der visuellen aber nicht in der auditiven Teilaufgabe stabil ist nachdem die Übung beendet wurde. Die vorliegenden Befunde zu Lernmechanismen werden in ein Modell von geübter Doppelaufgabenleistung, das Latent Bottleneck Model, integriert und neue Annahmen im Rahmen dieses Modells diskutiert. / Numerous studies showed that people have difficulty performing two tasks at the same time. This difficulty is indicated by additional performance costs in dual-task situations when compared to single-task situations, i.e. dual-task costs. However, recent evidence has shown a substantial reduction of dual-task costs through practice. The finding of dual-task costs at the beginning and the reduction thereof at the end of practice indicates that this reduction must be accomplished via specific learning mechanisms. Although such mechanisms have been addressed in previous studies, the specific mechanisms contributing to practice related dual-task cost reduction remained unknown. The aim of four studies in the present work is to specify these mechanisms by applying a dual-task situation including a visual and an auditory component task (Schumacher et al., 2001). Investigations on learning mechanisms within the component tasks aimed to identify loci of stage shortening in these tasks through practice. For the first time I showed that component task processing in dual-task situations is mainly shortened through a shortening at the response selection stage. In contrast, investigations on learning mechanisms between the component tasks focussed on the acquisition of task coordination skills. Here I provided evidence that these skills are acquired during dual-task practice and there is no acquisition of these skills during single-task practice. Additionally, I demonstrated that these skills are transferable to alternative dual-task situations. There is, however, no evidence for transfer of these skills to task switching and attentional blink paradigms. In order to further specify the result of the learning mechanisms, I showed that dual-task performance in the visual but not in the auditory task is stable after practice has finished. The present findings on learning mechanisms are integrated into a model of practiced dual-task performance, the latent bottleneck model, and new assumptions in the framework of this model are discussed.