No description available.

Eastern hemlock (Tsuga canadensis) is in decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; ‘HWA’) and, to a lesser extent, the elongate hemlock scale (Fiorinia externa; ‘EHS’). Many conifers respond to insect herbivory by inducing oleoresin-based defenses, however it is unknown whether eastern hemlock is capable of this inducible response. We conducted a plantation setting study of artificially infested saplings to determine if feeding by HWA or EHS induces changes in the tree’s volatile chemistry. The induced changes in volatiles we found were unlike the terpenoid-based defenses of related conifers. Only HWA feeding elevated methyl salicylate, a plant signal for systemic acquired resistance, and benzyl alcohol, a known antimicrobial and aphid deterrent. The influence of environmental conditions and tree life-stage on hemlock volatile chemistry, potentially important factors for wild hemlock populations, is unknown. We investigated whether mature and immature forest trees respond to HWA infestation with the same patterns of volatile production as plantation saplings in full sun and amended soils. HWA induced volatile changes comparable to those of plantation saplings, with many-fold benzenoid increases and no terpenoid-based resinosis. Nearly all volatiles were substantially more abundant in forest than plantation trees, suggesting the effect of site conditions should be addressed in investigations of mechanisms operative in HWA-resistant biotypes of eastern hemlock. Our findings represent the first important step toward understanding the influence of inducible phytochemical responses on hemlock susceptibility to exotic pests, and highlight the possibility of salicylic acid-dependent biosynthetic activity in this gymnosperm system.

Cyber-attacks are an increasing problem for organizations across the world. The attacks on systems are getting more and more sophisticated and thereby more and more difficult to protect against. The security of systems is crucial to protect your data from unauthorized access. One approach for testing the resilience of these systems is the use of threat modelling and attack simulations. The use of threat models also enables you to identify vulnerabilities in your infrastructure. The overall resilience of the system can then be increased by implementing protection against these vulnerabilities which can take many forms. There can be security issues regarding a single component in the infrastructure and more structural issues concerning more than one component in the system. Meta Attack Language (MAL) is a meta language to write threat languages of different systems. In MAL there exits different components called assets, these assets can have defenses. The problem is that structural weaknesses cannot be identified in the current state of the language. This thesis work will provide a solution to identify vulnerable patterns in a threat model and translate these pattern to secure patterns. A prototype has been created that take a threat model as input and outputs a new updated threat model. The prototype will translate the input to a graph database and run a series of predefined queries on the database that will identify and replace vulnerable patterns. A formal logic for finding vulnerable patterns is suggested and an API to change these patterns is implemented. The result shows that by running a model through the prototype, structural vulnerabilities can be identified and mitigated. This could potentially increase the overall resilience of the system. / Attacker på IT system är ett ökande problem för organisationer runt om i världen. Attackerna blir mer och mer sofistikerade och därmed svårare att skydda sig emot. Säkerheten av systemen är väldigt viktigt för att skydda data från obehörig åtkomst. Ett tillvägagångssätt för att testa säkerheten mot attacker är att använda hotmodeller och attack-simuleringar. Resultatet av en sådan simulering kan sedan användas för att göra systemet säkrare genom att implementera skydd mot kända sårbarheter. Dessa sårbarheter kan komma i många olika former. De kan finnas på en enskild komponent i arkitekturen eller så kan de bero på mer strukturella svagheter där flera komponenter berörs. Meta Attack Language (MAL) är ett meta-språk som kan användas för skapa hot-språk. I MAL så finns det olika komponenter som kan ha försvar associerat till sig. Problemet är att i det nuvarande stadiet av MAL så går det inte att identifiera strukturella svagheter där fler än en komponent är en del av problemet. Det här arbetet föreslår en lösning till att identifiera skadliga mönster och översätta dessa mönster till säkra mönster. En prototyp har tagits fram som tar en hotmodell som in-data och returnerar en uppdaterad hotmodell. Prototypen översätter hotmodellen till en grafdatabas och exekverar en serie av sökningar som identifierar och uppdaterar skadliga mönster. En logik för att hitta mönster föreslås och ett API av funktioner för att ändra mönster har utvecklats. Resultaten visar att genom körning av en modell genom prototypen så skulle detta potentiellt kunna öka systemens säkerhet.

No description available.

曹玉騫. / "2009年8月". / "2009 nian 8 yue". / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 128-133). / Abstracts in Chinese and English. / Cao Yuqian. / 引言 --- p.1 / Chapter 第一章 --- 河西地區出土簡牘硏究回顧 --- p.3 / 附：河西四郡建置過程及兩關位置考述 --- p.17 / Chapter 第一節 --- 四郡的建置年代 --- p.18 / Chapter 第二節 --- 兩關位置考述 --- p.25 / Chapter 第二章 --- 居延都尉下轄殄北候官、甲渠候官之烽隧及分布狀況 --- p.30 / Chapter 第一節 --- 殄北候官烽隧建置 --- p.31 / Chapter 第二節 --- 甲渠候官烽隧建置及方位分布 --- p.37 / Chapter 第三章 --- 居延都尉下轄卅井候官之烽隧及分布狀況 --- p.51 / Chapter 第四章 --- 肩水都尉下轄各候官之烽隧及邊塞分布狀況 --- p.66 / Chapter 第一節 --- 廣地候官烽隧建置 --- p.66 / Chapter 第二節 --- 橐他候官烽隧建置 --- p.68 / Chapter 第三節 --- 肩水候官烽隧建置 --- p.70 / Chapter 第四節 --- 肩水都尉轄區其它候官 --- p.83 / Chapter 第五章 --- 居延、肩水地區郵路走向考述 --- p.85 / Chapter 第一節 --- 居延都尉轄區郵驛里程考析 --- p.85 / Chapter 第二節 --- 肩水都尉轄區郵驛里程考析 --- p.98 / Chapter 第六章 --- 居延、肩水地區的烽隧及郵路建設與漢代邊防的關係 --- p.106 / 總結 --- p.119 / 附圖一今日甘肅省與漢代涼州剌史部所轄區域之比較 --- p.123 / 附圖二漢代河西地區塹壕、塞墙分布與郵路走向 --- p.123 / 附圖三張掖郡居延都尉轄區烽隧分布圖 --- p.124 / 附圖四張掖郡肩水都尉轄區烽隧分布圖 --- p.125 / 附圖五張掖郡居延、肩水兩都尉轄區烽隧分布全圖 --- p.126 / 附圖六張掖郡居延一一肩水地區郵路走向圖 --- p.127 / 參考書目 --- p.128

This article addresses the question of whether extreme weather events should form the basis for individuals or even the States, may be exempted from complying with its legal obligations.The old, but still very viable institution of force majeure can empower both companies and nations to absolve themselves of their responsibilities and duties. However, in a world where human-induced climate change is proven, could we say that such disasters are truly«natural»? Does it make sense, from a legal and factual matter, that they continue to allow the parties to be exempt from liability when modern science has shown that in all probability people, not some enigmatic power, have caused most universally of the problems that hold us harmless looking?Force majeure is based on the idea that the «man» somehow is separate from «nature». This article challenges this idea and argues that, in many cases, no longer makes sense to apply the institution of force majeure. At least, judges should be very careful in doing so for reasons of public policy and allocation of risks. In addition, the contracting parties must have enough caution to claim that they may be able to exempt themselves from future liability clauses appealing «force majeure». / Este artículo aborda la pregunta sobre si los eventos de clima extremo deben servir de base para que los particulares o, incluso los Estados, puedan eximirse de cumplir con sus obligaciones legales.La antigua, pero aún muy viable, institución de la fuerza mayor, puede facultar tanto a las empresas como a los Estados-Nación a eximirse de sus responsabilidades y deberes. Sin embargo, en un mundo donde el cambio climático antropogénico está probado,¿podríamos decir que tales desastres son verdaderamente «naturales»? ¿Acaso tiene sentido, desde un punto de vista legal y fáctico, que se les siga permitiendo a las partes eximirse de responsabilidad legal cuando la ciencia moderna ha demostrado con toda probabilidad que, las personas -no algún misterioso poder universal- han ocasionado la mayoría de los problemas por los que buscamos eximirnos de responsabilidad?La fuerza mayor se basa en la idea de que el «hombre», de alguna manera, se encuentra separado de la «naturaleza». Este artículo cuestiona esta idea y argumenta que, en muchos casos, ya no tiene sentido aplicar la institución de la fuerza mayor. Al menos, los jueces deben ser muy cuidadosos al hacerlo por razones de política pública y asignación de riesgos, así como las partes contratantes deben tener la suficiente precaución al pensar o pretender que pueden ser capaces de eximirse de responsabilidad futura invocando cláusulas de «fuerza mayor».

No description available.

The aim of this dissertation is to show how counter missile tactics for a fast attack craft armed with missiles [FAC(M)] against a surface-to-surface, fireand- forget missile [SSM] can be optimised. As a result the ship and missile will be modelled as generic concepts while the environment will be a chosen area of operations. The applicable methodology is to simulate the ship, missile and environment as well as the interactions between them. At the same time, the ship will be carrying out combinations of five separate missile counter measures. The methodology is then to build a dynamic simulation model to optimise soft kill tactics by a generic F AC(M) against a generic SSM in the chosen environment and evaluate the outcome of the simulation by viewing the experiment as a 25 factorial design and to analyse it accordingly. / Operations Research / M.Sc. (Operations Research)

Des études présentées dans cette thèse ont permis de démontrer que le gène du groupe Polycomb (PcG) Bmi1 est essentiel à l’auto-renouvellement des progéniteurs rétiniens immatures et pour le développement rétinien après la naissance. Ce travail illustre chez l’embryon que Bmi1 est hautement enrichie dans une sous-population de progéniteurs rétiniens exprimant le marqueur de surface SSEA-1 et différents marqueurs de cellules souches. À tous les stades de développement analysés, l’absence de Bmi1 résulte en une diminution de la prolifération et de l’auto-renouvellement des progéniteurs immatures. Pour mieux comprendre la cascade moléculaire en absence de Bmi1, nous avons inactivé p53 dans les colonies Bmi1-/-. Cette inactivation a permis une restauration partielle du potentiel d’auto-renouvellement. De plus, en absence de Bmi1, la prolifération et la maintenance de la population de progéniteurs rétiniens immatures localisés dans le corps ciliaire sont aussi affectées après la naissance. Bmi1 permet donc de distinguer les progéniteurs immatures de la population principale de progéniteurs, et est requis pour le développement normal de la rétine. Nous avons également démontré que l’oncogène Bmi1 est requis dans les neurones pour empêcher l’apoptose et l’induction d’un programme de vieillissement prématuré, causé par une baisse des défenses anti-oxydantes. Nous avons observé dans les neurones Bmi1-/- une augmentation des niveaux de p53, de la concentration des ROS et de la sensibilité aux agents neurotoxiques. Nous avons démontré ainsi que Bmi1 contrôle les défenses anti-oxydantes dans les neurones en réprimant l’activité pro-oxydante de p53. Dans les neurones Bmi1-/-, p53 provoque la répression des gènes anti-oxydants, induisant une augmentation des niveaux de ROS. Ces résultats démontrent pour la première fois que Bmi1 joue un rôle critique dans la survie et le processus de vieillissement neuronal. / The studies presented in this thesis establish that the Polycomb Group (PcG) gene Bmi1 is required for the self-renewal of immature retinal progenitor cells (RPCs) and for postnatal retinal development. Work performed in mouse embryos reveals that Bmi1 is highly enriched in a RPC subpopulation expressing the cell surface antigen SSEA-1 and different stem cell markers. Furthermore, at all developmental stages analysed, Bmi1 deficiency resulted in reduced proliferation and self-renewal of immature RPCs. To better understand the molecular cascade leading to this phenotype, we inactivated p53 in Bmi1-deficient colonies. p53 inactivation partially restored RPCs self-renewal potential. Moreover, the proliferation and the postnatal maintenance of an immature RPC population located in the ciliary body was also impaired in absence of Bmi1. Thus, Bmi1 distinguishes immature RPCs from the main RPC population and is required for normal retinal development. We have also shown that the oncogene Bmi1 is required in neurons to prevent apoptosis and the induction of a premature aging-like program characterized by reduced antioxidant defenses. We observed in Bmi1-deficient neurons an increased p53 and ROS levels, and a hypersensitivity to neurotoxic agents. We demonstrated that Bmi1 regulate antioxidant defenses in neurons by suppressing p53 pro-oxidant activity. In Bmi1-/- neurons, p53 induces antioxidant genes repression, resulting in increased ROS levels. These findings reveal for the first time the major role of Bmi1 on neuronal survival and aging.

L’œuf est un aliment riche en divers composés dont de nombreuses molécules antimicrobiennes qui sont les effectrices de son système de défense moléculaire innée et complètent l’action des immunoglobulines (IgYs) afin de protéger l’embryon. La composition en IgYs de l’œuf est sous la dépendance notamment des stimulations microbiennes de la poule. L’objectif de notre travail a été d’évaluer l’influence de ces mêmes stimulations sur le système de défense moléculaire innée du blanc d’œuf. Nous avons exploré cette hypothèse en utilisant deux approches expérimentales. La première était basée sur la comparaison de l’activité antibactérienne des blancs d’œufs de poules axéniques, de poules exemptes d’organismes pathogènes spécifiques (EOPS), et de poules conventionnelles. La seconde approche a testé les effets de deux types d’inductions du système immunitaire chez la poule: injection d’un immunostimulant, le lipopolysaccharide bactérien (LPS) et administration oral de souches vaccinales atténuées (virale, bactérienne et parasitaire). Nos résultats montrent que l’activité antibactérienne du blanc d’œuf est augmentée en fonction de la charge microbienne du milieu de vie de la poule, après stimulation de celle-ci par voie intraveineuse avec du LPS ou suite à la vaccination avec des souches atténuées virale ou bactérienne. Néanmoins cette augmentation est modérée de par son amplitude et son spectre antibactérien. Ces résultats suggèrent que les poules peuvent renforcer modérément l’activité antimicrobienne du blanc d’œuf en réponse à des stimuli microbiens de leur milieu et anticiper ainsi les besoins de l’embryon en termes de protection. / The egg is a balanced source of different nutrients and contains a myriad of antibacterial peptides/proteins that ensure its chemical protection. These molecules are a part of its innate molecular defense and, in addition to the maternal immunoglobulins IgY, contribute to the protection of the forming embryo whose development occurs ex utero. It is well documented that yolk immunoglobulin deposition is induced by the environmental microbiome of the hen but no such evidence is available for antimicrobial peptides/proteins. Therefore the aim of this thesis was to assess whether the hen has the ability to stimulate the innate molecular immunity of the egg white when facing a higher environmental microbial load (commensal or pathogenic). To address these questions, we developed two main experimental approaches; the first assessed the impact of the hen environmental microbial load through the comparison of three groups of hens with different immune status:-Germ free, -Specific pathogen free (SPF), and -conventional. The second approach explored the effect of different types of immune stimulation in hens: non-infectious stimulation (systemic injection of bacterial lipopolysaccharide (LPS)); immune stimulation using attenuated live vaccines (Infectious bronchitis virus vaccine, Salmonella enterica Enteritidis vaccine and a complex of Eimeria vaccine). Our results show that the activity of egg white is increased in response to higher microbial environmental charge, after LPS systemic stimulation or after vaccinating hens with live attenuated viral and bacterial strains. However this response is moderate both in its amplitude and microbial spectrum. Altogether, it appears that hens when subjected to immune stimuli, have the ability to reinforce moderately the antibacterial activity of the egg white as an attempt to anticipate the need of protection of their embryos.