Hatching a Hydra at the University of Maryland

Poster presentation for Hydra Connect 2016 conference describing the UMD Libraries' strategy for rolling out a new digital collections repository system based on Fedora 4

Newspapers Re-Issued: Developing a custom IIIF based newspaper viewer at the University of Maryland Libraries

Poster presentation at Code4Lib Conference 2017Many institutions are creating archives of digital newspapers, yet it is notoriously challenging to deliver an engaging and uncomplicated end user interface for such content. At the University of Maryland Libraries, we have created a custom portal for our crowdfunded campus newspaper digitization project, which is scheduled to debut in the spring of 2017. Based on stakeholder feedback, our portal’s newspaper viewer needed to support four unique features: (1) keyword search highlighting from the main portal application, (2) intuitive image clipping, (3) article segmentation highlighting, and (4) side-by-side display of OCR text with the digitized image. After evaluation, we determined that IIIF would be the most appropriate framework to integrate into existing UMD repository systems. In order to deliver the requested features, we chose Loris and Mirador as our server and viewer applications, respectively, and developed customizations for each, which have in turn been contributed back to their respective communities. Furthermore, we developed a PCDM Manifest application to take metadata about each newspaper issue from our Fedora 4 repository, transform it, and deliver IIIF manifests. UMD Libraries has also created a proof-of-concept method for embedding ALTO XML text coordinates in a Solr index, in order to enable dynamic annotation generation within the viewer. This development work ultimately enables our metadata to be repurposed across application boundaries for novel representations of our digital and digitized newspapers

Electrolyzers Enhancing Flexibility in Electric Grids

This paper presents a real-time simulation with a hardware-in-the-loop (HIL)-based approach for verifying the performance of electrolyzer systems in providing grid support. Hydrogen refueling stations may use electrolyzer systems to generate hydrogen and are proposed to have the potential of becoming smarter loads that can proactively provide grid services. On the basis of experimental findings, electrolyzer systems with balance of plant are observed to have a high level of controllability and hence can add flexibility to the grid from the demand side. A generic front end controller (FEC) is proposed, which enables an optimal operation of the load on the basis of market and grid conditions. This controller has been simulated and tested in a real-time environment with electrolyzer hardware for a performance assessment. It can optimize the operation of electrolyzer systems on the basis of the information collected by a communication module. Real-time simulation tests are performed to verify the performance of the FEC-driven electrolyzers to provide grid support that enables flexibility, greater economic revenue, and grid support for hydrogen producers under dynamic conditions. The FEC proposed in this paper is tested with electrolyzers, however, it is proposed as a generic control topology that is applicable to any load

A Catalytic Role for C–H/π Interactions in Base Excision Repair by <i>Bacillus cereus</i> DNA Glycosylase AlkD

DNA glycosylases protect genomic integrity by locating and excising aberrant nucleobases. Substrate recognition and excision usually take place in an extrahelical conformation, which is often stabilized by π-stacking interactions between the lesion nucleobase and aromatic side chains in the glycosylase active site. <i>Bacillus cereus</i> AlkD is the only DNA glycosylase known to catalyze base excision without extruding the damaged nucleotide from the DNA helix. Instead of contacting the nucleobase itself, the AlkD active site interacts with the lesion deoxyribose through a series of C–H/π interactions. These interactions are ubiquitous in protein structures, but evidence for their catalytic significance in enzymology is lacking. Here, we show that the C–H/π interactions between AlkD and the lesion deoxyribose participate in catalysis of glycosidic bond cleavage. This is the first demonstration of a catalytic role for C–H/π interactions as intermolecular forces important to DNA repair