Resolution of Stratifolds and Connection to Mather's Abstract Pre-Stratified Spaces

Many spaces which naturally occur in topology and algebraic geometry are not manifolds, but have a decomposition as a disjoint union of manifolds. Examples include algebraic varieties, orbit spaces of proper smooth group actions on manifolds and mappings cylinders of maps between manifolds. In 1998 M. Kreck began to develop a concept of stratified spaces so called stratifolds such that their bordism theory leads to a homology theory, which has the same coefficients as singular homology. In this thesis we focus on two subclasses of stratifolds with more geometrical structure, namely p-stratifolds and cornered p-stratifolds. First, we consider p-stratifolds as objects with singularities and try to resolve them, leaving the smooth top stratum untouched. The topological definition of the resolution is modelled on the one from algebraic geometry. In the second part of the thesis we establish the connection between abstract pre-stratified spaces in the sense of J. Mather and cornered p-stratifolds

The development of a start-up from idea to feasible business concept

This thesis report describes the development of the author’s start-up company, “a thousand words”. A comprehensive account is provided of this venture’s development from the initial rough idea to a feasible business concept that is ready to go to market. It is the author’s ambition to provide realistic insights into the development process which may offer motivation and confidence to other start-up entrepreneurs. The academic goal is to delineate the role of the theoretical knowledge base in entrepreneurship and provide examples of the implementation of appropriate tools and methods in a real-life case scenario. The research-oriented approach for this project is innovation. The author used a variety of methods to reach her research objectives. These ranged from traditional methods, such as documentary research, qualitative interviews and a quantitative survey to the rarer encountered diary method. There is no strict division between the theoretical and empirical sections; rather, these are intertwined within the respective chapter and topic. Each chapter of the thesis report starts with a short description of its content. The respective chapter’s content is always structured in the following way. First, the theoretical background is highlighted, e.g. definitions are given, general information on the topic provided. Then the application of the theoretical findings and theories to the case start-up “a thousand words” is presented. Finally, the respective interim results and findings are summed up. The results of this research and development work are as follows. The author identifies business planning approaches and tools suitable for a small start-up. She conducts market research for the case start-up, “a thousand words”, with both its customer groups. Furthermore, she designs and develops a Business Model Canvas and an elevator pitch presentation for the case start-up. There follow the marketing strategy and a minimum viable product (MVP) for ”a thousand words”. Finally, the author identifies the most essential skills for start-up entrepreneurs

Cardiovascular Deconditioning Resulting from 28-hour Bed-rest and the Efficacy of the Fluid Loading Countermeasure

This study tested the hypotheses that 1) 28h head-down bed-rest (HDBR) would result in significant hypovolemia and cardiovascular deconditioning, and that 2) NASA’s fluid loading protocol (ingestion of 15 ml/kg water with a 1g NaCl for every 125ml of water consumed) would restore normovolemia and prevent cardiovascular deconditioning resulting from 28h HDBR. Nine healthy men were tested in 5 testing scenarios, with a progressive lower body negative pressure (LBNP) protocol performed before and after each scenario to measure the subjects’ cardiovascular responses to orthostasis. Subjects were tested in two 28h HDBR conditions, without fluid loading (NFL) and with fluid loading (FL), as well as in three 4-hour control conditions to isolate the effects of circadian rhythm, HDBR, and fluid loading. After 28h NFL HDBR, plasma volume was reduced by 8%. There were no symptoms of syncope during orthostatic testing following 28h NFL HDBR, however cardiovascular deconditioning was apparent as there were significant increases in heart rate, reductions in central venous pressure, and reductions in portal vein diameter during LBNP testing. There were no changes in stroke volume, cardiac output, systemic vasoconstriction, cardiac measures, and arterial and cardiopulmonary baroreflex responses, and no evidence of splanchnic or venous pooling. This study also found that NASA’s fluid loading protocol was ineffective at restoring normovolemia after 28h HDBR, as there were no differences in plasma volume between 28h FL HDBR post and 28h NFL HDBR post tests (p=0.22). Cardiovascular deconditioning was not prevented by fluid loading as the heart rate response remained elevated and central venous pressure remained reduced after 28h FL HDBR. In addition, four of the nine subjects experienced nausea during administration of the fluid loading protocol prescription and two subjects vomited, further evidence that NASA’s fluid loading protocol is not effective at preventing orthostatic hypotension. Investigation of control models verified that deconditioning was the result of HDBR. It was also concluded that circadian rhythm did not affect the measured cardiovascular responses and the fluid loading protocol was ineffective at increasing blood volume in the absence of HDBR

Resolutions of p-stratifolds with isolated singularities

Recently M. Kreck introduced a class of stratified spaces called p-stratifolds [M. Kreck, Stratifolds, Preprint]. He defined and investigated resolutions of p-stratifolds analogously to resolutions of algebraic varieties. In this note we study a very special case of resolutions, so called optimal resolutions, for p-stratifolds with isolated singularities. We give necessary and sufficient conditions for existence and analyze their classification.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-36.abs.htm

A Comprehensive Resource for Induced Pluripotent Stem Cells from Patients with Primary Tauopathies.

Primary tauopathies are characterized neuropathologically by inclusions containing abnormal forms of the microtubule-associated protein tau (MAPT) and clinically by diverse neuropsychiatric, cognitive, and motor impairments. Autosomal dominant mutations in the MAPT gene cause heterogeneous forms of frontotemporal lobar degeneration with tauopathy (FTLD-Tau). Common and rare variants in the MAPT gene increase the risk for sporadic FTLD-Tau, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). We generated a collection of fibroblasts from 140 MAPT mutation/risk variant carriers, PSP, CBD, and cognitively normal controls; 31 induced pluripotent stem cell (iPSC) lines from MAPT mutation carriers, non-carrier family members, and autopsy-confirmed PSP patients; 33 genome engineered iPSCs that were corrected or mutagenized; and forebrain neural progenitor cells (NPCs). Here, we present a resource of fibroblasts, iPSCs, and NPCs with comprehensive clinical histories that can be accessed by the scientific community for disease modeling and development of novel therapeutics for tauopathies