Genetic Mechanisms for Anoxia Survival in C. Elegans

Oxygen deprivation can be pathological for many organisms, including humans. Consequently, there are several biologically and economically relevant negative impacts associated with oxygen deprivation. Developing an understanding of which genes can influence survival of oxygen deprivation will enable the formulation of more effective policies and practices. In this dissertation, genes that influence adult anoxia survival in the model metazoan system, C. elegans, are identified and characterized. Insulin-like signaling, gonad function and gender have been shown to influence longevity and stress resistance in the soil nematode, C. elegans. Thus, either of these two processes or gender may influence anoxia survival. The hypothesis that insulin-like signaling alters anoxia survival in C. elegans is tested in Aim I. The hypotheses that gonad function or gender modulates anoxia survival are tested in Aim II. Insulin-like signaling affects anoxia survival in C. elegans. Reduction of insulin-like signaling through mutation of the insulin-like receptor, DAF-2, increases anoxia survival rates in a gpd-2/3 dependent manner. The glycolytic genes gpd-2/3 are necessary for wild-type response to anoxia, and sufficient for increasing anoxia survival through overexpression. Gonad function and gender both affect anoxia survival in C. elegans. A reduction of ovulation and oocyte maturation, as measured by oocyte flux, is associated with enhanced anoxia survival in all cases examined to date. Reduction of function of several genes involved in germline development and RTK/Ras/MAPK signaling reduce ovulation and oocyte maturation while concurrently increasing anoxia survival. The act of mating does not influence anoxia survival, but altering ovulation through breeding or chemical treatment does. The male phenotype also increases anoxia survival rates independent of genotype. These studies have identified and characterized over ten different genotypes that affect adult survival of anoxia in C. elegans. Before these studies were conducted, there were no genes known to influence adult anoxia survival in C. elegans. Furthermore, these studies have begun to uncouple mechanisms of longevity and stress resistance

Future Proof: Preserving and Providing Access to Columbia's Audio Visual Collections

As part of a larger hidden collections initiative, in 2018, Columbia University Libraries embarked on a seven year project to digitize their unique audiovisual holdings. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with analog film/video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync both published and unpublished metadata between systems including our Voyager ILS and Hyacinth, and plan for an exponential increase in how digital media collections would be used by both patrons and staff. This presentation will examine the development, implementation, and lessons learned of these cross-departmental workflows as they pertain to the complex landscape of large-scale digital media preservation and access within research libraries

Unhiding the audiovisual past at Columbia University Libraries

As part of a larger hidden collections initiative, Columbia University Libraries initiated plans in 2018 to digitize their unique audiovisual holdings over seven years. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with audio and video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync metadata between systems including our Voyager ILS and Hyacinth, and plan for new initiatives such as the implementation of a rights management module and integration of crosswalks to ArchivesSpace. One additional outcome of the project’s first year is a deeper analysis of project statistics and workflows using project management methods to inform the future development and planning of the project for years 2-7. This presentation will examine the development of these shared workflows across curatorial, preservation, metadata, and digital technology units, challenges overcome, and lessons learned

Making Software into a Program: Columbia University Libraries' Hyacinth User Group

This presentation, delivered at the 2019 meeting of the Digital Library Forum, highlights the work of the Hyacinth User Group at Columbia University Libraries. The group has members from many divisions of the library including Application Development, Cataloging, Digital Collections, Institutional Repository and Digital Conversion. These staff members have come together to administer Hyacinth, Columbia’s metadata and content management application. This presentation focuses on two case studies that show the value such an administrative group can bring to the shared use of software - implementing relatedness statements and managing controlled vocabularies. In the case of relatedness statements, the group navigated the varied expressions of relatedness required by different library divisions avoiding collisions and blocks to future development. Shared management of controlled vocabularies has required the group to produce robust documentation and develop clear user permissions to prevent alteration of terms as well as a remediation process for safely removing erroneous terms from the system and records. In the pursuit of these projects, we have seen the vital need for software developers and metadata practitioners to work together. Each has a unique perspective of the problems at hand. The developers have created a powerful tool to organize and publish metadata to numerous websites and digital collections. The Hyacinth User Group has developed the policies and communication flows to ensure the application’s diverse group of users can wield that tool effectively and efficiently

Quantifying Phenotypic Variation in Isogenic Caenorhabditis elegans Expressing Phsp-16.2::gfp by Clustering 2D Expression Patterns

Isogenic populations of animals still show a surprisingly large amount of phenotypic variation between individuals. Using a GFP reporter that has been shown to predict longevity and resistance to stress in isogenic populations of the nematode Caenorhabditis elegans, we examined residual variation in expression of this GFP reporter. We found that when we separated the populations into brightest 3% and dimmest 3% we also saw variation in relative expression patterns that distinguished the bright and dim worms. Using a novel image processing method which is capable of directly analyzing worm images, we found that bright worms (after normalization to remove variation between bright and dim worms) had expression patterns that correlated with other bright worms but that dim worms fell into two distinct expression patterns. We have analysed a small set of worms with confocal microscopy to validate these findings, and found that the activity loci in these clusters are caused by extremely bright intestine cells. We also found that the vast majority of the fluorescent signal for all worms came from intestinal cells as well, which may indicate that the activity of intestinal cells is responsible for the observed patterns. Phenotypic variation in C. elegans is still not well understood but our proposed novel method to analyze complex expression patterns offers a way to enable a better understanding

From START to FINISH : the influence of osmotic stress on the cell cycle

Peer reviewedPublisher PD

Systematic Studies of the Centrality and sqrt(s_NN) Dependence of dE_T/deta and dN_ch/deta in Heavy Ion Collisions at Mid-rapidity

The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The sqrt(s_NN) dependence of dE_T/deta and dN_ch/deta per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dE_T/deta and dN_ch/deta is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with sqrt(s_NN). A survey of comparisons between the data and available theoretical models is also presented.Comment: 327 authors, 25 pages text, 19 figures, 17 tables, RevTeX 4. To be submitted to Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

ICAR: endoscopic skull‐base surgery

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Explaining the effect of rapid internationalization on horizontal foreign divestment in the retail sector. An extended penrosean perspective

Building on and extending Penrosean logic we argue that rapid international expansion by firms might lead to a breach of Penrosean constraints on efficient expansion and to subsequent divestment of international operations to bring firm scope back into Penrosean constraints. We further predict that intra-regional concentration and international experience moderate the above effect because they influence firms ability to avoid a breach of Penrosean constraints and/or weaken the consequences of such a breach. Using data on the international expansion and divestment of large retail MNEs over the period 2003-2012 we find empirical support for the proposed extended Penrose effect in explaining international divestment as well as for the moderating effects of intra-regional concentration and international experience. Our study contributes to the development of Penrosean logic and to our understanding of the factors that drive firms to divest overseas operations