4,823 research outputs found
Almost sure exponential stability of the Euler–Maruyama approximations for stochastic functional differential equations
No full textBy the continuous and discrete nonnegative semimartingale convergence theorems, this paper investigates conditions under which the Euler–Maruyama (EM) approximations of stochastic functional differential equations (SFDEs) can share the almost sure exponential stability of the exact solution. Moreover, for sufficiently small stepsize, the decay rate as measured by the Lyapunov exponent can be reproduced arbitrarily accurately
A Sure Foundation
No full textA book in which the author expresses how he believes people can live a good life
An Axiomatization of Linear Cumulative Prospect Theory with Applications to Portfolio Selection and Insurance Demand
No full textThe present paper combines loss attitudes and linear utility by providing an axiomatic analysis of corresponding preferences in a cumulative prospect theory (CPT) framework. CPT is one of the most promising alternatives to expected utility theory since it incorporates loss aversion, and linear utility for money receives increasing attention since it is often concluded in empirical research, and employed in theoretical applications. Rabin (2000) emphasizes the importance of linear utility, and highlights loss aversion as an explanatory feature for the disparity of significant small-scale risk aversion and reasonable large-scale risk aversion. In a sense we derive a two-sided variant of Yaari s dual theory, i.e. nonlinear probability weights in the presence of linear utility. The first important difference is that utility may have a kink at the status quo, which allows for the exhibition of loss aversion. Also, we may have different probability weighting functions for gains than for losses. The central condition of our model is termed independence of common increments. The applications of our model to portfolio selection and insurance demand show that CPT with linear utility has more realistic implications than the dual theory since it implies only a weakened variant of plunging.
Children's Centres as spaces of interethnic encounter in North East England
No full textThis paper explores the role of Sure Start Children's Centres as spaces of encounter between new migrants to the UK and ‘White English’ residents in host communities. Children's Centres were selected as the context for the research because they serve people with common needs (families with pre-school children), and because building social capital and mutual support among parents is part of their core purpose (Department for Education. (2013). Sure Start Children's Centres: Statutory guidance for local authorities, commissioners of local health services and Jobcentre Plus. Retrieved from http://www.media.education.gov.uk/assets/files/pdf/s/childrens%20centre%20stat%20guidance%20april%202013.pdf). Drawing on data from semi-structured interviews conducted with service users from Black and Minority Ethnic backgrounds (recent migrants) and service users representing ‘the majority’ white population in two urban areas in North East England, it explores the role of ethnicity and other factors relating to migration in shaping encounters in these spaces, and considers the perceived benefits of these interactions. It finds that interethnic encounter in Children's Centres is often seen by new migrant parents/carers primarily as an opportunity to improve English language skills, meeting an additional need to that of local ‘indigenous’ parents/carers. It further found that new migrant parents/carers often perceived Children's Centres as an opportunity to experience a particular version of the local community, facilitating more predictable encounters than encounters in the wider host community
Using an Experiential Process to Move Rural and Small-Membership A.M.E. Churches From the Survival Mode to the Empowerment Model, 1998
No full textA myriad of issues face the rural and small membership A.M.E. churches, such as lack of long-range planning, high denominational assessments, recurring financial problems, inadequately trained pastors, frequent pastoral movement, and acceptance versus adoption, making survivorship difficult. Therefore, the EMPRO Model (i.e., The Empowerment Project) is an instrument that will positively impact the A.M.E. Church and its treatment of the rural and small membership churches. To be sure, the Empowerment Project is capable of delivering the necessary tools and skills (planning, budget preparation, polity, calendar preparation, church history, stewardship and tithing) to the leadership (clergy and laity) of rural and small membership churches which will enable them to perform at a much higher level. Succinctly, the Holy Spirit is the ultimate vehicle that enables the Empowerment Project to move forth. It was the invisible presence of the Holy Spirit that empowered the Fairfield A.M.E. Church to exhibit an outward resolve to keep hope alive. Empowerment is the enhanced ability to accomplish clearly identified goals and objectives. The procedure was to select five A.M.E. churches from the Atlanta/North Georgia Conference of the Sixth Episcopal District of the A.M.E. Church to participate in the Empowerment Project. Each church fits the definition of either rural or small membership, or both. Four of the five churches selected were actually located in rural areas. The other church is located in the city of Atlanta. The churches selected have experienced similar struggles and difficulties. The findings of the study showed that the training seminar forum is a powerful tool for imparting information. Other results were: (1) The topics offered during the seminar sessions strengthened the participants' knowledge and understanding of the A.M.E. Church in general. (2) The information relating to budget preparation and church planning provided additional insights into how the congregation would better be able to meet its goals because of better planning. (3) The session relating to the need for the local church to develop a mission statement that clearly outlined what it saw as its own identifiable mission caused the participants to be better able to identify 'do-able' local goals and objectives. (4) The seminar sessions provided an opportunity for useful dialogue to be exchanged between the key officers of the church concerning the mission and purpose of the local church. (5) The seminars provided the 'how to' for all of the participants involved. (6) Pastors viewed the training as an enormous help to their local church ministry. A more informed pastorate and a more informed laity bring about a much higher level of local church performance, i.e., empowerment. When folks know what to do and how to do it, the overall functioning of the church is enhanced and, thus, empowered
Genesis and biological activity of cerebral cavernomas in adult and pediatric patients: an immunohistochemical study of 87 patients
No full textDie vorliegende Arbeit soll zur Kärung der Genese und der biologischen Aktivität cerebraler Kavernome in adulten und pädiatrischen Patienten beitragen. Es wurden die Operationspräparate von 87 Kavernompatienten mittels immunhistochemischer Technik auf das Vorhandensein relevanter Antigene im Gewebe untersucht. Sowohl die Kavernome von Patientengruppen mit unterschiedlicher klinischer Symptomatik, als auch die Kavernome von adulten Patienten verglichen mit denen pädiatrischer Patienten, weisen eine unterschiedliche biologische Aktivität auf. Dabei kommt den Antigenen VEGF und Endoglin, sowie den mit diesen Antigenen assoziierten Pathways besondere Bedeutung zu.The thesis contributes to the illucidation of the genesis and the biological activity of cerebral cavernomas in adult and pediatric patients. The specimens of 87 patients suffering from cerebral cavernomas, who underwent surgery, were investigatet with immunohistochemical technique to give proof of the existance of relevant antigenes in the tissue. The cavernomas of patient groups with different clinical symptoms, as well as the cavernomas of adult patients compared to those of pediatric patients, had a different biological activity. Herewith the antigenes VEGF and Endoglin and the associated pathways play keyroles
Traces and shards of self-injury: Strange accounting with “Author X”
No full textIn this strange account autoethnography, three or four authors explore their lived experiences with self-injury. Strange accounting is both a post-modern style of text, and a method for keeping identities concealed when risks and secrets are in play. Author X, a post-modern place-keeper for an anonymous author who may or may not have contributed to this manuscript, introduces a new dimension and layer of concealment. With Author X in-play and under erasure, the reader will never be sure if there were three or four authors on this manuscript. Through strange accounting, a post-structuralist/postmodernist frame will be applied to understanding the self-injury experience. We frame self-injury as a social practice and, for some, an everyday norm, while remaining acutely aware of the stigma surrounding the topic of self-injury. Each of us, coupled with Author X, provide the others cover to trace stories of self-injury through the literature, our flesh, and our lives
From sapientia honorabilissima to nobilitas animae: a Note on the Concept of "Nobility" in Ulrich of Strasbourg’s De summo bono
No full textIn many respects, the adjective “noble” plays a signi cant role in Ulrich of Strasbourg’s De summo bono. It de nes contemplative happiness and philosophical wis- dom, and delineates a remarkable character of the intellect (human and divine). In ex- amining some signi cant occurrences of the term, I intend to focus my attention on its theoretical meaning and on the sources which have in uenced its use. In this way, I will demonstrate that “nobility” is a necessary, key factor for investigating what the real plea- sure of knowledge consists in for Ulrich
Qualitative detection of CCM1, CCM2 and CCM3 and analysis of morphological and proliferative changes after downregulation of expression of CCM1 in HUV endothelialcells
No full textKavernome sind vaskuläre Neubildungen im zentralen Nervensystem, welche aus dilatierten, dünnwandigen, sinusoidalen Blutgefäßen bestehen. Histologisch zeigen sich nur anormal vorhandene oder gänzlich fehlende Tight Junctions der Endothelzellen und teilweise fehlende astrozytische Fortsätze, was zu einer Vergrößerung der Zwischenräume der Zellen führt. Klinisch weisen die Patienten zerebrale Blutungen, Krampfleiden oder fokale neurologische Defizite auf. Die Prävalenz des Kavernoms beträgt 0,5%, von diesen weisen jedoch nur 20 bis 30% klinische Symptome auf. Das Kavernom tritt sowohl sporadisch als auch autosomal dominant vererbt auf. Die familiären Fälle stehen im Zusammenhang mit drei Genen und deren, zu einem Funktionsverlust führenden, Mutationen. Mutationen in CCM1 sind für 40 bis 50% der familiären Fälle verantwortlich, in CCM2 für 10 bis 20% und in CCM3 für etwa 40%. Das Modell der Entstehung des Kavernoms gründet sich auf dem von Knudson erstellten two-hit Mechanismus und wird von murinen Forschungsergebnissen mit Ccm1+/- Trp53-/- doppelt mutierten Mäusen unterstützt. Sowohl CCM1 (KRIT1) als auch CCM2 (Malcavernin) sind in den β1 Integrin Signalweg eingebunden, welcher unter anderem Zelladhäsion, Zellmigration und Zellproliferation reguliert. Außerdem sind beide Gene an der Aktivierung der p38MAPK beteiligt, von welcher murine Forschungsergebnisse zeigen konnten, dass Mäuse ohne p38αMapk signifikante Defekte in der plazentalen Angiogenese und in der Entwicklung der Blutgefäße, besonders im Bereich des Kopfes, aufwiesen. Außerdem konnte nachgewiesen werden, dass CCM3 (PDCD10) mit dem ERK Signalweg, welcher ebenfalls Einfluss auf Zellproliferation und Transformation hat, interagiert.
Ziel der Arbeit war es, die Expression der CCM Gene nachzuweisen und dadurch die Theorie, dass Endothelzellen in der Pathogenese des Kavernoms eine Hauptrolle spielen, zu unterstützen. Außerdem sollte ein Zellkultursystem erstellt werden, welches uns die Möglichkeit gibt, funktionelle Veränderungen der Endothelzellen nach Runterregulation von CCM1 festzustellen.
Mittels Echtzeit RT-PCR konnte nachgewiesen werden, dass HUV Endothelzellen alle drei CCM Gene exprimieren. Außerdem war es möglich, ein Zellkultursystem in HUV Endothelzellen zu etablieren, in welchem CCM1 erfolgreich runterreguliert werden konnte. Validiert wurde dieses System ebenfalls mittels Echtzeit RT-PCR. Nachfolgend wurden Veränderungen der Morphologie und der Proliferation erfasst. Morphologisch zeigten sich die Zellen nach Transfektion größer und spindelförmiger als die Kontrollen, und sie bildeten vermehrt strangförmige Strukturen. Diese Beobachtungen ähnelten Zellen isoliert aus Kavernomen in Angiogenese-Assays. Die Ergebnisse dieser Arbeit unterstützen die Vermutung, dass der Verlust der Funktion von CCM1 in Endothelzellen die Hauptrolle in der zum Kavernom führenden Veränderung spielt. Im Proliferationsassay ließ sich eine Verringerung der Proliferationsrate feststellen, welche zeigt, dass ein Funktionsverlust von CCM1 einen direkten Einfluss auf die Zellproliferation hat.Cerebral cavernous malformations are vascular neoplasms in the central nervous system. They consist of dilated, thinwalled, sinusoidal bloodvessels. Histologically the tight junctions of these endothelial cells forming the cerebral cavernous malformation are abnormal or totaly missing, also the appendages of the astrozytes can be partly missing, which results wider gaps between the cells.
Main Symptoms are cerebral bleeding, convulsion or focal neurological deficencies.
The prevalence of cerebral cavernous malformation averages at about 0,5%, of these only 20 to 30% present with clinical symptoms. Cerebral cavernous malformations can occur sporadic or can be autosomal dominant inherited. The familial cases are associated with loss of function mutations within three genes. Mutations of CCM1 are responsible for 40 to 50%, of CCM2 for 10 to 20% and mutations of CCM3 for about 40% of the familial cases.
The model of genesis of the cerebral cavernous malformation builds on the two-hit mechanisms established by Knudson, and is supported by Ccm1+/- Trp53-/- mice. CCM1 (KRIT1) as well as CCM2 (Malcavernin) are integrated in β1 integrine signaling, which among other factors regulates adhesion, migration and proliferation of cells. Also both genes are involved in activation of p38MAPK. P38Mapk-/- mice have significant defects in plazental angiogenesis and development of bloodvessels, especially in brain vessels. Moreover CCM3 (PDCD10) interacts with ERK signaling, which also affects proliferation and transformation of cells.
Aim of the present work was to detect the expression of all three CCM genes and to test the hypothesis that endothelial cells play a major role in the pathogenesis of cerebral cavernous malformations. Moreover we wanted to created a tissue culture system, to detect functional changes in endothelial cells after downregulation of CCM1.
Using real-time RT-PCR we found the expression of all three CCM genes in HUV endothelial cells. A tissue culture system was established also in HUV endothelial cells, where we were able to downregulate CCM1 by transient transfection with short interfering RNA.
Morphologically knock down cells were bigger and more fusiform compared to the control cells. The cells also formed more restiform structures. Similar observations were made in cells isolated from cerebral cavernous malformations in angiogenesis assays. The results of this thesis confirm, that the loss of function of CCM1 in endothelial cells plays a major role in changes leading to the pathogenesis of cerebral cavernous malformations.
The accomplished proliferationassay showed a reduction of proliferation, which demonstrates that the loss of function of CCM1 has a direct effect on cellproliferation
sj-docx-1-tan-10.1177_17562864211055694 – Supplemental material for Surgical outcome and prognostic factors in spinal cord ependymoma: a single-center, long-term follow-up study
No full textSupplemental material, sj-docx-1-tan-10.1177_17562864211055694 for Surgical outcome and prognostic factors in spinal cord ependymoma: a single-center, long-term follow-up study by Oliver Gembruch, Mehdi Chihi, Merle Haarmann, Ahmet Parlak, Marvin Darkwah Oppong, Laurèl Rauschenbach, Anna Michel, Ramazan Jabbarli, Yahya Ahmadipour, Ulrich Sure, Philipp Dammann and Neriman Özkan in Therapeutic Advances in Neurological Disorders</p
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