Search results for "Intersection"

PlaToLoCo: the first web meta-server for visualization and annotation of low complexity regions in proteins

2020

Abstract Low complexity regions (LCRs) in protein sequences are characterized by a less diverse amino acid composition compared to typically observed sequence diversity. Recent studies have shown that LCRs may co-occur with intrinsically disordered regions, are highly conserved in many organisms, and often play important roles in protein functions and in diseases. In previous decades, several methods have been developed to identify regions with LCRs or amino acid bias, but most of them as stand-alone applications and currently there is no web-based tool which allows users to explore LCRs in protein sequences with additional functional annotations. We aim to fill this gap by providing PlaToL…

Blood vessels and feature points detection on retinal images

2009

In this paper we present a method for the automatic extraction of blood vessels from retinal images, while capturing points of intersection/overlap and endpoints of the vascular tree. The algorithm performance is evaluated through a comparison with handmade segmented images available on the STARE project database (STructured Analysis of the REtina). The algorithm is performed on the green channel of the RGB triad. The green channel can be used to represent the illumination component. The matched filter is used to enhance vessels w.r.t. the background. The separation between vessels and background is accomplished by a threshold operator based on gaussian probability density function. The len…

CELEBRATING WOMEN ARTISTS IN JORDAN: REFRAMING GENDER ROLES AS RESISTANCE

This thesis focuses on women artists in the capital of Jordan, Amman, and particularly on their cultural practices as an expression of a creative agency. These women create independent spaces, cultural initiatives, public performances and original artworks that allow the reframing of gender roles in neoliberal patriarchal societies today. Beyond labeling the emergence of a new female activism, or femtivism, as feminist or revolutionary, I suggest reading it as the reconfiguration of a new wave of feminisms in Jordan, which engages with the visual arts, the contemporary cultural scene of Amman, the geography of the city and the political commitment, often in informal domains rather than in i…

Exploring the intersection of e-commerce and context in family business in China: the effects on organisational form and identity

2019

This chapter melds these interests of understanding how the context of e-Commerce and family business affects organisational form and subsequently organisational identity by integrating a narrative about the development of family business and e-Commerce in China with an exploratory analysis of two Chinese family businesses. Institutional theory informs this discussion (Scott, 2008: Suddaby, Elsbach, Greenwood, Meyer and Zilber, 2010). After describing why businesses adopt e-Commerce, and illustrating the contextual conditions in China that foster the development of private enterprises such as family businesses, and the adoption of e-Commerce, the chapter subsequently explores the question “…

Patricia Hill Collins e il femminismo nero

2022

The cointribution focuses on the fugura of Patricia Hill Collins. In 2009 she was the 100th president of the American Sociological Association (ASA) and the first African American woman elected to this position. Collins fits into the strand called Black Feminism although her main areas of research have touched on issues of racism, social inequality, sexuality and the sociology of knowledge in addition to gender issues.

Ultrafast ring-opening/closing and deactivation channels for a model spiropyran-merocyanine system.

2011

The photochemistry of a model merocyanine-spiropyran system was analyzed theoretically at the MS-CASPT2//SA-CASSCF(14,12) level. Several excited singlet states were studied in both the closed spiropyran and open merocyanine forms, and the paths to the different S(1)/S(0) conical intersections found were analyzed. After absorption of UV light from the spiropyran form, there are two possible ultrafast routes to efficient conversion to the ground state; one involves the rupture of the C(spiro)-O bond leading to the open form and the other involves the lengthening of the C(spiro)-N bond with no photoreaction. From the merocyanine side the excited state can reach a very broad S(1)/S(0) conical i…

Sign and rank covariance matrices

2000

The robust estimation of multivariate location and shape is one of the most challenging problems in statistics and crucial in many application areas. The objective is to find highly efficient, robust, computable and affine equivariant location and covariance matrix estimates. In this paper, three different concepts of multivariate sign and rank are considered and their ability to carry information about the geometry of the underlying distribution (or data cloud) are discussed. New techniques for robust covariance matrix estimation based on different sign and rank concepts are proposed and algorithms for computing them outlined. In addition, new tools for evaluating the qualitative and quant…

Large systems of path-repellent Brownian motions in a trap at positive temperature

2006

We study a model of $ N $ mutually repellent Brownian motions under confinement to stay in some bounded region of space. Our model is defined in terms of a transformed path measure under a trap Hamiltonian, which prevents the motions from escaping to infinity, and a pair-interaction Hamiltonian, which imposes a repellency of the $N$ paths. In fact, this interaction is an $N$-dependent regularisation of the Brownian intersection local times, an object which is of independent interest in the theory of stochastic processes. The time horizon (interpreted as the inverse temperature) is kept fixed. We analyse the model for diverging number of Brownian motions in terms of a large deviation princip…

Hitting straight lines by compound Poisson process paths

1990

In a recent article Mallows and Nair (1989,Ann. Inst. Statist. Math.,41, 1–8) determined the probability of intersectionP{X(t)=αt for somet≥0} between a compound Poisson process {X(t), t≥0} and a straight line through the origin. Using four different approaches (direct probabilistic, via differential equations and via Laplace transforms) we extend their results to obtain the probability of intersection between {X(t), t≥0} and arbitrary lines. Also, we display a relationship with the theory of Galton-Watson processes. Additional results concern the intersections with two (or more) parallel lines.

Linear Recursive Equations, Covariance Selection, and Path Analysis

1980

Abstract By defining a reducible zero pattern and by using the concept of multiplicative models, we relate linear recursive equations that have been introduced by econometrician Herman Wold (1954) and path analysis as it was proposed by geneticist Sewall Wright (1923) to the statistical theory of covariance selection formulated by Arthur Dempster (1972). We show that a reducible zero pattern is the condition under which parameters as well as least squares estimates in recursive equations are one-to-one transformations of parameters and of maximum likelihood estimates, respectively, in a decomposable covariance selection model. As a consequence, (a) we can give a closed-form expression for t…