Nuclei for totally point determining graphs

AbstractThe nucleus (edge nucleus) of a point determining graph is defined by Geoffroy and Sumner to be the set of all points (edges) whose removal leaves the graph point determining. It is the purpose of this paper to develop the analogous concepts for totally point determining graphs, that is, graphs in which distinct points have distinct neighborhoods and closed neighborhoods

Query-Based Summarization using Rhetorical Structure Theory

Research on Question Answering is focused mainly on classifying the question type and finding the answer. Presenting the answer in a way that suits the user’s needs has received little attention. This paper shows how existing question answering systems—which aim at finding precise answers to questions—can be improved by exploiting summarization techniques to extract more than just the answer from the document in which the answer resides. This is done using a graph search algorithm which searches for relevant sentences in the discourse structure, which is represented as a graph. The Rhetorical Structure Theory (RST) is used to create a graph representation of a text document. The output is an extensive answer, which not only answers the question, but also gives the user an opportunity to assess the accuracy of the answer (is this what I am looking for?), and to find additional information that is related to the question, and which may satisfy an information need. This has been implemented in a working multimodal question answering system where it operates with two independently developed question answering modules

Direction problems in affine spaces

This paper is a survey paper on old and recent results on direction problems in finite dimensional affine spaces over a finite field.Comment: Academy Contact Forum "Galois geometries and applications", October 5, 2012, Brussels, Belgiu

Nuclear rupture at sites of high curvature compromises retention of DNA repair factors.

The nucleus is physically linked to the cytoskeleton, adhesions, and extracellular matrix-all of which sustain forces, but their relationships to DNA damage are obscure. We show that nuclear rupture with cytoplasmic mislocalization of multiple DNA repair factors correlates with high nuclear curvature imposed by an external probe or by cell attachment to either aligned collagen fibers or stiff matrix. Mislocalization is greatly enhanced by lamin A depletion, requires hours for nuclear reentry, and correlates with an increase in pan-nucleoplasmic foci of the DNA damage marker γH2AX. Excess DNA damage is rescued in ruptured nuclei by cooverexpression of multiple DNA repair factors as well as by soft matrix or inhibition of actomyosin tension. Increased contractility has the opposite effect, and stiff tumors with low lamin A indeed exhibit increased nuclear curvature, more frequent nuclear rupture, and excess DNA damage. Additional stresses likely play a role, but the data suggest high curvature promotes nuclear rupture, which compromises retention of DNA repair factors and favors sustained damage

Earthtime Lesson Plan for U/Pb Dating (grade 8-12)

The Earthtime Lesson Plan is a complete description of a radiometric dating module taught to high school students at MIT. U/Pd dating and it's uses, teacher background, materials needed, time frame and National Science Standards are all provided as well as worksheets with teacher solutions. This module, consisting of three activities, is initially designed for a 90min period. Educational levels: High school