Intersection local times of fractional Brownian motions with H∈(0,1)H\in(0,1) as generalized white noise functionals

In $\R^d$, for any dimension $d\geq 1$, expansions of self-intersection local times of fractional Brownian motions with arbitrary Hurst coefficients in $(0,1)$ are presented. The expansions are in terms of Wick powers of white noises (corresponding to multiple Wiener integrals), being well-defined in the sense of generalized white noise functionals.Comment: 17 page

Introduction : nation branding and competitive identity in world politics

To date (critical) geopolitics has had little to say about contemporary competitive identity practices of nation branding in global politics, while existing analyses of nation branding in other disciplines have tended to overlook its geopolitical dimensions. This expanded Introduction (and the special issue as a whole) therefore seeks to explore some of the implications of nation branding for geopolitics, while simultaneously utilizing the insights of critical geopolitics to shed light on nation branding practices. The Introduction makes the case for a broad conception of nation branding that challenges claims it is immutably linked to capitalist logics in an era of globalization. It subsequently explores claims that nation branding is simply an updated form of nation building and that it is also an inherently benign and peace promoting activity. The Introduction ends by highlighting how, despite claims that the contemporary prevalence of nation branding practices is indicative of a categorical shift from a geopolitical to a geoeconomic world, nation branding practices frequently remain deeply infused with rather traditional geopolitical scripts

Transition Matrix Monte Carlo

Although histogram methods have been extremely effective for analyzing data from Monte Carlo simulations, they do have certain limitations, including the range over which they are valid and the difficulties of combining data from independent simulations. In this paper, we describe an complementary approach to extracting information from Monte Carlo simulations that uses the matrix of transition probabilities. Combining the Transition Matrix with an N-fold way simulation technique produces an extremely flexible and efficient approach to rather general Monte Carlo simulations.Comment: Maui Conference on Statistical Physic

POLAR: Instrument and Results

We describe the design, performance, and results of a polarimeter used to make precision measurements of the 2.7 K cosmic microwave background. In the Spring of 2000 the instrument searched for polarized emission in three microwave frequency bands spanning 26–36 GHz. The instrument achieved high sensitivity and long-term stability, and has produced the most stringent limits to date on the amplitude of the large angular scale polarization of the cosmic microwave background radiation

p53 mediates failure of human definitive hematopoiesis in dyskeratosis congenita

Summary: Dyskeratosis congenita (DC) is a bone marrow failure syndrome associated with telomere dysfunction. The progression and molecular determinants of hematopoietic failure in DC remain poorly understood. Here, we use the directed differentiation of human embryonic stem cells harboring clinically relevant mutations in telomerase to understand the consequences of DC-associated mutations on the primitive and definitive hematopoietic programs. Interestingly, telomere shortening does not broadly impair hematopoiesis, as primitive hematopoiesis is not impaired in DC cells. In contrast, while phenotypic definitive hemogenic endothelium is specified, the endothelial-to-hematopoietic transition is impaired in cells with shortened telomeres. This failure is caused by DNA damage accrual and is mediated by p53 stabilization. These observations indicate that detrimental effects of telomere shortening in the hematopoietic system are specific to the definitive hematopoietic lineages. This work illustrates how telomere dysfunction impairs hematopoietic development and creates a robust platform for therapeutic discovery for treatment of DC patients. : By directly assessing primitive or definitive hematopoiesis derived from telomerase-mutant hESCs, Batista and colleagues show that telomere shortening specifically impairs definitive hematopoietic potential, while primitive hematopoiesis is instead enhanced. This system offers the unprecedented capability to study hematopoietic failure and suggests that bone marrow failure in DC patients is reversible. Keywords: embryonic stem cells, hematopoiesis, bone marrow failure, telomerase, dyskeratosis congenita, disease modeling, telomeres, telomere damag