NMR Characterizations of Candidate Battery Electrolytes

Enormous strides have been made in next-generation power sources to build a more sustainable society. Energy storage has become a limiting factor in our progress, and there are huge environmental and financial incentives to find the next step forward in battery technology. This work discusses NMR methods for characterizing materials for use in battery application, with a special focus on relaxometry and diffusometry. Examples are provided of various recent investigations involving novel candidate electrolyte materials with different collaborators. Works discussed in this thesis include: the characterization of a new disruptive solid polymer electrolyte technology, investigations of the dynamics of super concentrated aqueous electrolytes, and studies of glyme-based electrolytes. Experimental results are interpreted and the impact on the continued development of the materials is analyzed

Community structures, interactions and dynamics in London’s bicycle sharing network

Bikesharing schemes are transportation systems that not only provide an efficient mode of transportation in congested urban areas, but also improve last-mile connectivity with public transportation and local accessibility. Bikesharing schemes around the globe generate detailed trip data sets with spatial and temporal dimensions, which, with proper mining and analysis, reveal valuable information on urban mobility patterns. In this paper, we study the London bicycle sharing dataset to explore community structures. Using a novel clustering technique, we derive distinctive behavioural patterns and assess community interactions and spatio-temporal dynamics. The analyses reveal self-contained, interconnected and hybrid clusters that mimic London’s physical structure. Exploring changes over time, we find geographically isolated and specialized communities to be relatively consistent, while the remaining system exhibits volatility, especially during and around peak commuting times. By increasing our understanding of the collective behaviour of the bikesharing users, this analysis supports policy appraisal, operational decision-making and motivates improvements in infrastructure design and management

Benzo-fused Lactams from a Diversity-oriented Synthesis (DOS) Library as Inhibitors of Scavenger Receptor BI (SR-BI)-mediated Lipid Uptake

We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure–activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50 = 0.10 μM) and solubility (79 μM in PBS), and it was designated as probe ML312

HIV Care Providers’ Role Legitimacy as Supporters of Their Patients’ Alcohol Reduction

Although HIV care providers are strategically situated to support their patients’ alcohol reduction efforts, many do not do so, sometimes failing to view this support as consistent with their roles. Using data collected from 112 HIV providers in 7 hospital-based HIV Care Centers in the NYC metropolitan area, this paper examines the correlates of providers’ role legitimacy as patients’ alcohol reduction supporters. Results indicate that providers (1) responsible for a very large number of patients and (2) with limited confidence in their own ability to give this assistance, but high confidence intheir program’s ability to do so, were less likely to have a high level of role legitimacy as patients’ alcohol reduction supporters. Findings suggest the types of providers to target for alcohol reduction support training

Estimating age-dependent survival from age-aggregated ringing data - extending the use of historical records

Bird ring-recovery data have been widely used to estimate demographic parameters such as survival probabilities since the mid-twentieth century. However, while the total number of birds ringed each year is usually known, historical information on age at ringing is often not available. A standard ring-recovery model, for which information on age at ringing is required, cannot be used when historical data are incomplete. We develop a new model to estimate agedependent survival probabilities from such historical data when age at ringing is not recorded; we call this the historical data model. This new model provides an extension to the model of Robinson (2010) by estimating the proportion of the ringed birds marked as juveniles as an additional parameter. We conduct a simulation study to examine the performance of the historical data model and compare it with other models including the standard and conditional ringrecovery models. Simulation studies show that the approach of Robinson (2010) can cause bias in parameter estimates. In contrast, the historical data model yields similar parameter estimates to the standard model. Parameter redundancy results show that the newly developed historical data model is comparable to the standard ring-recovery model, in terms of which parameters can be estimated, and has fewer identifiability issues than the conditional model. We illustrate the new proposed model using Blackbird and Sandwich Tern data. The new historical data model allows us to make full use of historical data and estimate the same parameters as the standard model with incomplete data and in doing so, detect potential changes in demographic parameters further back in time

The Next Generation Virgo Cluster Survey. X. Properties of Ultra-Compact Dwarfs in the M87, M49 and M60 Regions

We use imaging from the Next Generation Virgo cluster Survey (NGVS) to present a comparative study of ultra-compact dwarf (UCD) galaxies associated with three prominent Virgo sub-clusters: those centered on the massive, red-sequence galaxies M87, M49 and M60. We show how UCDs can be selected with high completeness using a combination of half-light radius and location in color-color diagrams ($u^*iK_s$ or $u^*gz$). Although the central galaxies in each of these sub-clusters have nearly identical luminosities and stellar masses, we find large differences in the sizes of their UCD populations, with M87 containing ~3.5 and 7.8 times more UCDs than M49 and M60, respectively. The relative abundance of UCDs in the three regions scales in proportion to sub-cluster mass, as traced by X-ray gas mass, total gravitating mass, number of globular clusters, and number of nearby galaxies. We find that the UCDs are predominantly blue in color, with ~85% of the UCDs having colors similar to blue GCs and stellar nuclei of dwarf galaxies. We present evidence that UCDs surrounding M87 and M49 may follow a morphological sequence ordered by the prominence of their outer, low surface brightness envelope, ultimately merging with the sequence of nucleated low-mass galaxies, and that envelope prominence correlates with distance from either galaxy. Our analysis provides evidence that tidal stripping of nucleated galaxies is an important process in the formation of UCDs.Comment: 37 pages, 40 figures. To appear in The Astrophysical Journa

Piperazinyl quinolines as chemosensitizers to increase fluconazole susceptibility of Candida albicans clinical isolates

The effectiveness of the potent antifungal drug fluconazole is being compromised by the rise of drug-resistant fungal pathogens. While inhibition of Hsp90 or calcineurin can reverse drug resistance in Candida, such inhibitors also impair the homologous human host protein and fungal-selective chemosensitizers remain rare. The MLPCN library was screened to identify compounds that selectively reverse fluconazole resistance in a Candida albicans clinical isolate, while having no antifungal activity when administered as a single agent. A piperazinyl quinoline was identified as a new small-molecule probe (ML189) satisfying these criteria.National Institutes of Health (U.S.) (1 R03 MH086456-01

Murine Gut Microbiota Is Defined by Host Genetics and Modulates Variation of Metabolic Traits

The gastrointestinal tract harbors a complex and diverse microbiota that has an important role in host metabolism. Microbial diversity is influenced by a combination of environmental and host genetic factors and is associated with several polygenic diseases. In this study we combined next-generation sequencing, genetic mapping, and a set of physiological traits of the BXD mouse population to explore genetic factors that explain differences in gut microbiota and its impact on metabolic traits. Molecular profiling of the gut microbiota revealed important quantitative differences in microbial composition among BXD strains. These differences in gut microbial composition are influenced by host-genetics, which is complex and involves many loci. Linkage analysis defined Quantitative Trait Loci (QTLs) restricted to a particular taxon, branch or that influenced the variation of taxa across phyla. Gene expression within the gastrointestinal tract and sequence analysis of the parental genomes in the QTL regions uncovered candidate genes with potential to alter gut immunological profiles and impact the balance between gut microbial communities. A QTL region on Chr 4 that overlaps several interferon genes modulates the population of Bacteroides, and potentially Bacteroidetes and Firmicutes–the predominant BXD gut phyla. Irak4, a signaling molecule in the Toll-like receptor pathways is a candidate for the QTL on Chr15 that modulates Rikenellaceae, whereas Tgfb3, a cytokine modulating the barrier function of the intestine and tolerance to commensal bacteria, overlaps a QTL on Chr 12 that influence Prevotellaceae. Relationships between gut microflora, morphological and metabolic traits were uncovered, some potentially a result of common genetic sources of variation

Gene content evolution in the arthropods

Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity