Understanding Neural Pathways in Zebrafish through Deep Learning and High Resolution Electron Microscope Data

The tracing of neural pathways through large volumes of image data is an incredibly tedious and time-consuming process that significantly encumbers progress in neuroscience. We are exploring deep learning's potential to automate segmentation of high-resolution scanning electron microscope (SEM) image data to remove that barrier. We have started with neural pathway tracing through 5.1GB of whole-brain serial-section slices from larval zebrafish collected by the Center for Brain Science at Harvard University. This kind of manual image segmentation requires years of careful work to properly trace the neural pathways in an organism as small as a zebrafish larva (approximately 5mm in total body length). In automating this process, we would vastly improve productivity, leading to faster data analysis and breakthroughs in understanding the complexity of the brain. We will build upon prior attempts to employ deep learning for automatic image segmentation extending methods for unconventional deep learning data.Comment: 8 pages, 5 figures (1a to 5c), PEARC '18: Practice and Experience in Advanced Research Computing, July 22--26, 2018, Pittsburgh, PA, US

Why Are We Permanently Stuck in an Elevator? A Software Engineering Perspective on Game Bugs

In the past decade, the complexity of video games have increased dramatically and so have the complexity of software systems behind them. The difficulty in designing and testing games invariably leads to bugs that manifest themselves across funny video reels on graphical glitches and millions of submitted support tickets. This paper presents an analysis of game developers and their teams who have knowingly released bugs to see what factors may motivate them in doing so. It examines different development environments as well as inquiring into varied types of game platforms and play-style. Above all, it seeks out how established research on software development best practices and challenges should inform understanding of these bugs. These findings may lead to targeted efforts to mitigate some of the factors leading to glitches, tailored to the specific needs of the game development team

Faulhaber's Theorem on Power Sums

We observe that the classical Faulhaber's theorem on sums of odd powers also holds for an arbitrary arithmetic progression, namely, the odd power sums of any arithmetic progression $a+b, a+2b, ..., a+nb$ is a polynomial in $na+n(n+1)b/2$. While this assertion can be deduced from the original Fauhalber's theorem, we give an alternative formula in terms of the Bernoulli polynomials. Moreover, by utilizing the central factorial numbers as in the approach of Knuth, we derive formulas for $r$-fold sums of powers without resorting to the notion of $r$-reflexive functions. We also provide formulas for the $r$-fold alternating sums of powers in terms of Euler polynomials.Comment: 12 pages, revised version, to appear in Discrete Mathematic

Labor Union and Linguistic Attributes in Firm Disclosure

Little research examines managers’ language itself in the presence of labor unions, especially using a rich communication channel such as earnings conference calls. By disentangling the two latent components of linguistic complexity (i.e. information and obfuscation) using conference call transcripts, I find that firms with stronger labor unions tend to disclose less information and, surprisingly, employ less obfuscation. However, the negative relation between obfuscation and union strength is driven by the loss firms subsample, indicating that the strategic obfuscation of negative news is less likely for firms with a powerful labor union in order to be forthcoming about negative information to gain bargaining power. Furthermore, I document that unionized firms tend to disclose less forward-looking information, and use more negative words in their narratives. This study provides a comprehensive view on the nuanced linguistic styles and contents via which firms react to labor unions

A Study of Metadata Element Co-Occurrence

Purpose – This paper aims to investigate the internet web page metadata usage behavior in terms of their metadata element co-occurrences. Metadata are designed to facilitate both web publishers/authors to organize their web pages and search engines to index the web pages accurately

Bridge Resilience Assessment with INSPIRE Data

This project proposed a methodology to assess the impact of corrosion on the performance of bridges. The combined analytical and numerical modeling of shear-critical and lap-spliced columns is detailed, and outcomes are verified with previous experimental test data. The impact of corrosion on risk is assessed through conducting fragility analyses. Results quantify the increase in failure probabilities of these structures, measured by increasing probabilities of exceeding defined damage states, with increasing levels of corrosion. Corrosion is found to have a larger impact on increasing probabilities of exceeding more severe damage states. Twenty percent mass loss of reinforcement increases the probability of exceeding the complete damage state by up to 49% and 34% for a shear-critical and lap-spliced column, respectively. The effect is more pronounced at intermediate loading intensities, where there is uncertainty about the performance of the structure. Comparing between failure modes, bridges with columns of short lap splice are more vulnerable to collapse under the same degree of corrosion compared with shear-critical columns

Updating Bridge Resilience Assessment based on Corrosion and Foundation Scour Inspection Data

Aging and degradation of bridge structural components due to corrosion and scour create severe safety issues in the structural system and can lead to possible bridge failures. Collecting and analyzing inspection data provide a way to monitor and assess the safety condition of bridges. This paper proposes a framework to utilize collected inspection data to assess the condition of a bridge through updating both component- and system-level fragility curves of the bridge. Particularly, collected data such as mass loss of reinforcement and depth of scour hole are utilized to update the mechanical properties of structural members in the finite element model. Fragility curves are then updated through performing a series of nonlinear time analyses based on the inspection data. As bridges age, they are susceptible to increasing corrosion and scour. This study investigates the performance of bridges considering the combined effect of reinforcement corrosion and foundation scour under extreme loadings such as seismic events to assess bridge resilience. Fragility results quantify increases in the probabilities of damage and collapse of the structural system as measured mass loss and scour depth increase

Role of γ-glutamyltranspeptidase in the pathogenesis of Helicobacter suis and Helicobacter pylori infections

Helicobacter (H.) suis can colonize the stomach of pigs as well as humans, causing chronic gastritis and other gastric pathological changes including gastric ulceration and mucosa-associated lymphoid tissue (MALT) lymphoma. Recently, a virulence factor of H. suis, gamma-glutamyl transpeptidase (GGT), has been demonstrated to play an important role in the induction of human gastric epithelial cell death and modulation of lymphocyte proliferation depending on glutamine and glutathione catabolism. In the present study, the relevance of GGT in the pathogenesis of H. suis infection was studied in mouse and Mongolian gerbil models. In addition, the relative importance of H. suis GGT was compared with that of the H. pylori GGT. A significant and different contribution of the GGT of H. suis and H. pylori was seen in terms of bacterial colonization, inflammation and the evoked immune response. In contrast to H. pylori Delta ggt strains, H. suis Delta ggt strains were capable of colonizing the stomach at levels comparable to WT strains, although they induced significantly less overall gastric inflammation in mice. This was characterized by lower numbers of T and B cells, and a lower level of epithelial cell proliferation. In general, compared to WT strain infection, ggt mutant strains of H. suis triggered lower levels of Th1 and Th17 signature cytokine expression. A pronounced upregulation of B-lymphocyte chemoattractant CXCL13 was observed, both in animals infected with WT and ggt mutant strains of H. suis. Interestingly, H. suis GGT was shown to affect the glutamine metabolism of gastric epithelium through downregulation of the glutamine transporter ASCT2