• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 38
  • 10
  • 5
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 106
  • 17
  • 15
  • 12
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

The lowest echelon in Network Centric Warfare : possibilities and limitations in the soldier level command, control and communication system

Hassgård, Ulf January 2002 (has links)
Like many other military forces around the world the Swedish Armed Forces have started a transition towards anetwork centric defence. This thesis will centre on what information services that will be needed in the lowestechelons of the network (i.e. at soldier level). The visions and predictions on the technical (r)evolution are in somecases exaggerated. Possible short-range communication techniques by the soldier in the frontline due to throughputlimitations have been analysed. IEEE 802.11x and Bluetooth are the leading short-range communications techniquesexamined along with techniques such as HiperLan/2, UWB and 60 GHz in this aspect. The conclusions will show howmuch data that will be possible to transmit in this short-range network. Through literature and comparative studiesbetween different countries’ projects for the future soldier, as well as interviews and study visits, the obviousconclusion is that the basic equipment for the soldier as a part of the Network will be devices for communications,navigation and positioning, and presentation. This will be complemented with weapons sensors, target acquisitionequipment, etc. In a 5 to 10-year perspective it will not be possible to transmit high-resolution video on a low-speeddata connection. It will, on the other hand, be possible to send speech, messages, still images, low quality video, targetdata, etc. to and from the future soldier. Apart from speech, all of the information above must be compiled andpresented in some way to the soldier in a C3-system. The human-machine interface will in many cases be built ongraphics and moving pictures. The resolution of these pictures, as another contributor to the throughput, will also beexamined in the context of this thesis as well as the contribution to the throughput from error correction andencryption. The result points out HiperLAN/2 as the most promising technique, followed by UWB or 60-GHz, but themost feasible in the near future will be IEEE 802.11b, since the others are not yet commercialised products. / Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP T 00-02
92

Protein engineering to explore and improve affinity ligands

Linhult, Martin January 2003 (has links)
<p>In order to produce predictable and robust systems forprotein purification and detection, well characterized, small,folded domains descending from bacterial receptors have beenused. These bacterial receptors, staphylococcal protein A (SPA)and streptococcal protein G (SPG), possess high affinity to IgGand / or HSA. They are composed of repetitive units in whicheach one binds the ligand independently. The domains foldindependently and are very stable. Since the domains also havewellknown three-dimensional structures and do not containcysteine residues, they are very suitable as frameworks forfurther protein engineering.</p><p>Streptococcal protein G (SPG) is a multidomain proteinpresent on the cell surface of<i>Streptococcus</i>. X-ray crystallography has been used todetermine the binding site of the Ig-binding domain. In thisthesis the region responsible for the HSA affinity of ABD3 hasbeen determined by directed mutagenesis followed by functionaland structural analysis. The analysis shows that the HSAbindinginvolves residues mainly in the second α-helix.</p><p>Most protein-based affinity chromatography media are verysensitive towards alkaline treatment, which is the preferredmethod for regeneration and removal of contaminants from thepurification devices in industrial applications. Here, aprotein engineering strategy has been used to improve thetolerance to alkaline conditions of different domains fromprotein G, ABD3 and C2. Amino acids known to be susceptibletowards high pH were substituted for less alkali susceptibleresidues. The new, engineered variants of C2 and ABD shownhigher stability towards alkaline pH. Also, very important forthe potential use as affinity ligands, these mutated variantsretained the secondary structure and the affinity to HSA andIgG, respectively. Moreover, dimerization was performed toinvestigate whether a higher binding capacity could be obtainedby multivalency. For ABD, binding studies showed that divalentligands coupled using non-directed chemistry demonstrated anincreased molar binding capacity compared to monovalentligands. In contrast, equal molar binding capacities wereobserved for both types of ligands when using a directed ligandcoupling chemistry involving the introduction and recruitmentof a unique C-terminal cysteine residue.</p><p>The staphylococcal protein A-derived domain Z is also a wellknown and thoroughly characterized fusion partner widely usedin affinity chromatography systems. This domain is consideredto be relatively tolerant towards alkaline conditions.Nevertheless, it is desirable to further improve the stabilityin order to enable an SPA-based affinity medium to withstandeven longer exposure to the harsh conditions associated withcleaning in place (CIP) procedures. For this purpose adifferent protein engineering strategy was employed. Smallchanges in stability due to the mutations would be difficult toassess. Hence, in order to enable detection of improvementsregarding the alkaline resistance of the Z domain, a by-passmutagenesis strategy was utilized, where a mutated structurallydestabilized variant, Z(F30A) was used as a surrogateframework. All eight asparagines in the domain were exchangedone-by-one. The residues were all shown to have differentimpact on the alkaline tolerance of the domain. By exchangingasparagine 23 for a threonine we were able to remarkablyincrease the stability of the Z(F30A)-domain towards alkalineconditions. Also, when grafting the N23T mutation to the Zscaffold we were able to detect an increased tolerance towardsalkaline treatment compared to the native Z molecule. In allcases, the most sensitive asparagines were found to be locatedin the loops region.</p><p>In summary, the work presented in this thesis shows theusefulness of protein engineering strategies, both to explorethe importance of different amino acids regarding stability andfunctionality and to improve the characteristics of aprotein.</p><p><b>Keywords:</b>binding, affinity, human serum albumin (HSA),albumin-binding domain (ABD), affinity chromatography,deamidation, protein A, stabilization, Z-domain, capacity,protein G, cleaning-in-place (CIP), protein engineering, C2receptor.</p>
93

Design and synthesis of wide bite angle phosphacyclic ligands

Gillespie, Jason A. January 2012 (has links)
By examining structure activity relationships for a given catalytic reaction it is possible to discover what ligand features and parameters lead to stable and highly active/selective catalyst systems. With this knowledge in hand it may be possible to rationally design next generation ligands and catalysts to affect improved substrate transformations, with higher selectivities and faster reaction times. The success of Burk's DuPhos ligands in asymmetric hydrogenation demonstrated that chiral phosphacycles can be a potent source of chiral induction, whilst in a similar vein the work of van Leeuwen and Kamer established the wide bite angle xanthene based ligands as excellent catalysts in a range of reactions including hydroformylation. In a preliminary study with Osborne they showed that combining these wide bite angle ligand backbones with Burk's phospholane moieties led to a new powerful ligand in asymmetric allylic substitution. To examine the potential of combining these two ligand features further we designed and synthesised nine new C2-symmetric bidentate wide bite angle bisphosphacyclic ligands, featuring phosphetane, phospholane or diazaphospholane rings, aiming at a wide diversity of steric and electronic properties. The application of these ligands as chiral auxiliaries in transition metal catalysed reactions, including; hydrogenation, hydrocyanation, hydroformylation and allylic alkylation has been investigated. Good to excellent enantioselectivities were observed in all reactions, with maximum ee's of 92.5% observed in hydrogenation, using N-(3,4-dihydro-1-napthalenyl)-acetamide as substrate, and of 96.2% in the alkylation of 1,3-diphenyl-2-propenyl acetate.
94

Measuring a Platoon Commander's Performance in a Complex, Dynamic and Information Rich Environment / Mätning av en Plutonchefs Prestation i en Komplex, Dynamisk och Informationsrik Miljö

Melbi, Alexander January 2021 (has links)
Command and control (C2) environments are complex, dynamic and rich in information. Thus, measuring the performance of an agent in a C2-system, in this case a platoon commander, poses a challenging task for the researcher. To measure the performance of a platoon commander in this thesis, the OODA loop is used as a model for representing the four processes in which the platoon commander is engaged in during a military C2 mission. In accordance with these processes, performance measurements for the platoon commander are identified. The relevance of the performance measurements, to the C2 tasks and goals of the platoon commander, are tested through three studies conducted in a simulated warfare scenario, and two workshops, one with a platoon commander and one with two scientists. As a result of the studies and workshops, an assessment tool for measuring the C2 tasks and goals of the platoon commander, is developed. This assessment tool consists of modified versions of the Crew Awareness Rating Scale (CARS), the Situation Awareness Global Assessment Technique (SAGAT) and the NASA-Task Load Index (NASA-TLX), as well as generic performance measurements measuring fratricide, deaths and completion of overarching goal.
95

Kristallstrukturen der C2B-Domäne von Rabphilin-3A und der PP2C-ähnlichen Phosphatase tPphA von Thermosynechococcus elongatus BP-1 / Crystal structures of the C2B domain of Rabphilin-3A and the PP2C-like phosphatase tPphA of Thermosynechococcus elongatus BP-1

Schlicker, Christine 05 June 2006 (has links)
No description available.
96

Approaching death in the classical tradition

Cameron, Peter January 2008 (has links)
The thesis consists of five chapters: the first functions as an overture; the second, third and fourth deal with Plato, Cicero and Montaigne respectively; and the fifth raises some questions. The overture explores the ways in which Odysseus, Lucretius and Seneca approached death, and in the process introduces some obvious distinctions - between death viewed as the act of dying and death viewed as the state of being dead, between the death which comes to everyone and the death which comes to me, between our own death and the death of others - and anticipates certain recurring themes. The second chapter, on Plato, is concerned chiefly with the Phaedo and the question of what is involved in "the practice of death". This entails an examination of related concepts and terminology in the Gorgias and the Republic, and of the whole subject of Platonic myth. The third chapter discusses Cicero's views on death and immortality - both the considered reflections of the philosopher and the spontaneous reactions of the bereaved father - principally as these emerge from the Tusculan Disputations and the letters to Atticus. The fourth chapter approaches Montaigne - his own experiences of death, the relationship between his earlier and later approaches, the tension between his professed Catholicism and his pagan inclinations, the difficulty and perhaps undesirability of extracting a 'message' from the Essais on this or any other subject. The conclusion asks to what extent these various approaches succeed in what they set out to do, and whether any generalised, objective approach to death can ever successfully address the individual predicament, either in relation to one's own death or in facing bereavement.
97

Command and control of Special Operations Forces missions in the US Northern Command Area of Responsibility

McGregor, Otis W., III 03 1900 (has links)
Approved for public release, distribution is unlimited / The need for a well thought out, planned, and rehearsed command and control organization to conduct special operations in the US Northern Command Area of Responsibility is vital to success in defending the Homeland. Currently, USNORTHCOM does not have an apportioned or assigned command and control structure for the conduct of special operations. This thesis analyzes three courses of action to fulfill this requirement: use the current USNORTHCOM battle staff command structure including the integration of the Standing Joint Force Headquarters-North; rely on the newly formed US Special Operations Command's Joint Task Force Structures; and establish a Theater Special Operations Command North assigned to USNORTHCOM. Through the conduct of analysis and research this thesis recommends that The Joint Staff direct the reorganization required to establish a Theater Special Operations Command North to exercise command and control of special operations forces conducting operations in the USNORTHCOM AOR. / Lieutenant Colonel, United States Army
98

Genealogy of Resilience in the Ontario Looking After Children System

Latour, Laurie-Carol 03 January 2017 (has links)
Resiliency has become common in child welfare parlance in recent decades and producing resilient youth is touted as the panacea to improving notoriously poor outcomes for youth in care, when compared to youth not in the care of the state. The Looking After Children (LAC) system emerged in the U.K out of neoliberal and managerial policies of the 1990s. The LAC system, and its corresponding Assessment and Action Record (AAR), was subsequently imported to Canada and has been heralded to foster resilience in youth in care. The AAR is composed of hundreds of tick box questions posed to young people in care, child welfare workers, and foster parents; these questions are pedagogical and the mined data from the AAR is aggregated to inform child welfare policy. The Looking After Children: A Practitioner’s Guide (Lemay & Ghazal, 2007) instructs workers how to administer the AAR, Second Canadian adaptation (AAR- C2), and it informs workers how to do their job. The notion of resilience in the Practitioner's Guide and the AAR-C2 are based in normative development and day to day experiences (Lemay & Ghazal, 2007). My interest in the LAC system emerges out of my experiences as a child welfare worker and my experience of being a youth in care. I wondered how it was, given the oppressive track record of child welfare in Canada, that the state could initiate a system to produce normal youth. This was a particularly salient question given the massive over- representation of Indigenous youth in foster care. With this critical curiosity as a point of departure I employed a Foucauldian inspired discourse analysis of the Looking After Children: A Practitioner’s Guide (2007, University of Ottawa Press), and three versions of its corresponding Assessment and Action Record, Second Canadian adaptation (AAR- C2) (2006, 2010, 2016, University of Ottawa). My analysis asked the question: How have we come to this ideal of resiliency? What were the contingencies and complex set of practices that enabled this specific notion of resilience to emerge in child welfare? What are the material outcomes of this notion of resilience? My findings suggest that: Youth in care are produced as deviant and outside of normal development, versus the desired resilient youth; youth in care and foster parents are responsibilized to produce resilient outcomes, which can never actually be achieved; the AAR-C2 acts as a surveillance system to enable to production of neoliberal subjects; the LAC system and the AAR-C2 are a method of colonization of Indigenous youth in care. / Graduate
99

NK Cell Tolerance of Self-Specific Apecific Activating Receptor KIR2DS1 in Individuals with Cognate HLA-C2 Ligand / Acquisition de la tolérance au soi des cellules tueuses naturelles (NK) KIR2DS1 chez des sujets exprimant des antigènes HLA-C2

Pittari, Gianfranco 12 July 2013 (has links)
Les cellules tueuses naturelles (NK) sont régulées par des récepteurs activateurs et inhibiteurs. La plupart des récepteurs inhibiteurs reconnaisse des molécules du complexe majeur d'histocompatibilité (CMH) de classe I, et protège les cellules saines des phénomènes d'auto-immunité médiés par les cellules NK. Cependant, certains récepteurs activateurs, incluant le récepteur killer cell Ig-like receptor (KIR) 2DS1, reconnaissent aussi des ligands CMH de classe I. Cela pose la question de savoir comment les cellules NK qui expriment des récepteurs activateurs deviennent tolérantes au soi. Nous avons cherché à déterminer si la présence de HLA-C2, le ligand du récepteurs 2DS1, peut induire les cellules NK qui expriment le 2DS1 à développer un état de tolérance au soi. Indépendamment de la présence ou de l'absence du ligand HLA-C2 dans le donneur, une activité anti-HLA-C2 a été identifiée in vitro dans certains clones NK 2DS1-positifs. La fréquence des clones NK avec réactivité anti-HLA-C2 était élevée parmi les donneurs homozygotes pour HLA-C1. De façon étonnante, nous n'avons pas constaté de différence statistiquement significative dans la fréquence de cytotoxicité anti-HLA-C2 entre les donneurs HLA-C2 hétérozygotes et les donneurs sans ligand HLA-C2. Par contre, les donneurs HLA-C2 homozygotes montrent une fréquence réduite de clones NK avec réactivité anti-HLA-C2 par rapport aux autres donneurs. Clones 2DS1-positifs qui co-expriment des KIR inhibiteurs spécifiques des molécules HLA de classe I du soi n’étaient pas communément cytotoxiques, et la cytotoxicité anti-HLA-C2 était limité presque exclusivement à des clones positifs seulement pour 2DS1 (« single positive » 2DS1 clones). Nous avons aussi identifié des clones 2DS1 « single positive » avec réactivité anti-HLA-C2 dans des patients recevant une greffe de cellules souches hématopoïétiques à partir de donneurs 2DS1. Ces résultats montrent que plusieurs cellules NK avec réactivité anti-HLA-C2 sont présentes dans des donneurs 2DS1 soit hétérozygotes soit homozygotes pour HLA-C1. En revanche, les clones 2DS1-positifs obtenus par des donneurs homozygotes pour HLA-C2 sont fréquemment tolérants aux antigènes HLA-C2. / NK cells are regulated by inhibiting and activating cell surface receptors. Most inhibitory receptors recognize MHC-class I antigens, and protect healthy cells from NK cell-mediated auto-aggression. However, certain activating receptors, including the human killer cell Ig-like receptor (KIR) 2DS1, also recognize MHC-class I. This raises the question of how NK cells expressing such activating receptors are tolerized to host tissues. We investigated whether the presence of HLA-C2, the cognate ligand for 2DS1, induces tolerance in 2DS1-expressing NK cells. Anti-HLA-C2 activity could be detected in vitro in some 2DS1 positive NK clones irrespective of presence or absence of HLA-C2 ligand in the donor. The frequency of anti-HLA-C2 reactivity was high in donors homozygous for HLA-C1. Surprisingly, there was no significant difference in frequency of anti-HLA-C2 cytotoxicity in donors heterozygous for HLA-C2 and donors without HLA-C2 ligand. However, donors homozygous for HLA-C2 had significantly reduced frequency of anti-HLA-C2 reactive clones as compared to all other donors. 2DS1 positive clones that express inhibitory KIR for self-HLA class I were commonly non-cytotoxic, and anti-HLA-C2 cytotoxicity was nearly exclusively restricted to 2DS1 single positive clones lacking inhibitory KIR. 2DS1 single positive NK clones with anti-HLA-C2 reactivity were also present post-transplantation in HLA-C2 positive recipients of hematopoietic stem cell transplants from 2DS1 positive donors. These results demonstrate that many NK cells with anti-HLA-C2 reactivity are present in HLA-C1 homozygous and heterozygous donors with 2DS1. In contrast, 2DS1 positive clones from HLA-C2 homozygous donors are frequently tolerant to HLA-C2.
100

Spectroscopie moléculaire : calcul de spectres, mesures des températures de rotation et de vibration dans les plasmas thermiques

Faure, Géraldine 05 December 1997 (has links) (PDF)
Ce travail porte sur le diagnostic des températures de vibration et de rotation des molécules dans les plasmas thermiques.<br /><br />Ce mémoire comporte deux grandes parties : l'une concerne le calcul de spectres moléculaires et la deuxième partie est consacrée à la comparaison des spectres dans quatre cas expérimentaux différents.<br /><br />Un code de calcul a été réalisé pour simuler des spectres d'espèces diatomiques. Ce code a été essentiellement appliqué aux radicaux C2, CN, à la molécule N2 et à l'ion N2+ avec comme paramètres variables les températures de vibration et de rotation. Cette partie commence par une description de la molécule diatomique et de ses propriétés. <br />Ensuite la méthode pour calculer les spectres est explicitée : <br />détermination des longueurs d'onde,<br />de leur intensité,<br />application d'une fonction d'appareil,<br />obtention du spectre final. <br />L'influence des températures de rotation et de vibration sur les intensités des raies est prise en compte ainsi que celle de la fonction d'appareil. Ces spectres sont calculés, pour une expérience donnée, de manière à déterminer ces deux paramètres par comparaison avec les spectres obtenus par la mesure.<br /><br />Cette méthode a été utilisée sur quatre plasmas différents : <br />une flamme oxy-acétylénique,<br />un arc stabilisé dans une chambre de Maecker,<br />une torche à plasma ICP,<br />une décharge entre deux électrodes liquides. <br />Les températures de rotation et de vibration ont été déterminées par la comparaison de spectres. Ainsi des profils de températures ont pu être réalisés.<br /><br />En annexe, les valeurs numériques nécessaires aux calculs de spectres sont répertoriées pour le système de Swan de C2, le système violet de CN, le second système positif de N2 et le premier système négatif de N2+.

Page generated in 0.0432 seconds