Civitas: Implementation of a Threshold Cryptosystem

This paper describes the implementation of a threshold cryptosystem for Civitas, a secure electronic voting system. The cryptosystem improves the availability of Civitas by enabling tabulation to complete despite the failure of some agents. The implementation includes a sophisticated distributed key generation protocol, which was designed by Gennaro, Jarecki, Krawczyk, and Rabin. The cryptosystem is implemented in Jif, a security-typed language

Image Bodies, Avatar Ontologies: Rendering the Virtual in Digital Culture

In 2009 five avatar-themed films were released, one of which became the highest grossing film to date, signaling that in addition to their popularity in videogames and virtual worlds, avatars are culturally salient figures which demand scholarly attention. Avatars, virtual environments, and user behavior have evolved significantly since virtual reality captured public and academic attention at the close of the twentieth century, and this dissertation is an attempt to theorize the avatar in contemporary digital culture. By interlacing new media philosophy and analyses of cinematic texts I situate the avatar at the nexus between digital images and interactive bodies, with implications for both cinema and virtual environments. Avatarial interfaces position users in an embodiment of connections which in some ways evokes the cyborg body, but the avatar as a theoretical figure places greater stress on the relation between human embodiment and (digital) images, as well as suggesting a move from cyborg fragmentation toward an avatarial gestalt. Avatars are also fruitful bodies for thinking through agency and gender in contemporary society, and engaging the lost `body\u27 of the picture as film has been supplanted by digital imagery. In this regard, virtuality, as a conceptual state pertaining to images, embodiment, technology, and philosophy, serves as the connective theoretical tissue linking bodies and images. Ultimately, in this dissertation I employ the avatar in an exploration of the ways in which we are already virtual, and how we have become avatarial in our own skin

Functional genomics with a comprehensive library of transposon mutants for the sulfate-reducing bacterium Desulfovibrio alaskensis G20.

UnlabelledThe genomes of sulfate-reducing bacteria remain poorly characterized, largely due to a paucity of experimental data and genetic tools. To meet this challenge, we generated an archived library of 15,477 mapped transposon insertion mutants in the sulfate-reducing bacterium Desulfovibrio alaskensis G20. To demonstrate the utility of the individual mutants, we profiled gene expression in mutants of six regulatory genes and used these data, together with 1,313 high-confidence transcription start sites identified by tiling microarrays and transcriptome sequencing (5' RNA-Seq), to update the regulons of Fur and Rex and to confirm the predicted regulons of LysX, PhnF, PerR, and Dde_3000, a histidine kinase. In addition to enabling single mutant investigations, the D. alaskensis G20 transposon mutants also contain DNA bar codes, which enables the pooling and analysis of mutant fitness for thousands of strains simultaneously. Using two pools of mutants that represent insertions in 2,369 unique protein-coding genes, we demonstrate that the hypothetical gene Dde_3007 is required for methionine biosynthesis. Using comparative genomics, we propose that Dde_3007 performs a missing step in methionine biosynthesis by transferring a sulfur group to O-phosphohomoserine to form homocysteine. Additionally, we show that the entire choline utilization cluster is important for fitness in choline sulfate medium, which confirms that a functional microcompartment is required for choline oxidation. Finally, we demonstrate that Dde_3291, a MerR-like transcription factor, is a choline-dependent activator of the choline utilization cluster. Taken together, our data set and genetic resources provide a foundation for systems-level investigation of a poorly studied group of bacteria of environmental and industrial importance.ImportanceSulfate-reducing bacteria contribute to global nutrient cycles and are a nuisance for the petroleum industry. Despite their environmental and industrial significance, the genomes of sulfate-reducing bacteria remain poorly characterized. Here, we describe a genetic approach to fill gaps in our knowledge of sulfate-reducing bacteria. We generated a large collection of archived, transposon mutants in Desulfovibrio alaskensis G20 and used the phenotypes of these mutant strains to infer the function of genes involved in gene regulation, methionine biosynthesis, and choline utilization. Our findings and mutant resources will enable systematic investigations into gene function, energy generation, stress response, and metabolism for this important group of bacteria

Loss of the PTCH1 tumor suppressor defines a new subset of plexiform fibromyxoma.

BackgroundPlexiform fibromyxoma (PF) is a rare gastric tumor often confused with gastrointestinal stromal tumor. These so-called "benign" tumors often present with upper GI bleeding and gastric outlet obstruction. It was recently demonstrated that approximately one-third of PF have activation of the GLI1 oncogene, a transcription factor in the hedgehog (Hh) pathway, via a MALAT1-GLI1 fusion protein or GLI1 up-regulation. Despite this discovery, the biology of most PFs remains unknown.MethodsNext generation sequencing (NGS) was performed on formalin-fixed paraffin-embedded (FFPE) samples of PF specimens collected from three institutions (UCSD, NCI and OHSU). Fresh frozen tissue from one tumor was utilized for in vitro assays, including quantitative RT-PCR and cell viability assays following drug treatment.ResultsEight patients with PF were identified and 5 patients' tumors were analyzed by NGS. An index case had a mono-allelic PTCH1 deletion of exons 15-24 and a second case, identified in a validation cohort, also had a PTCH1 gene loss associated with a suspected long-range chromosome 9 deletion. Building on the role of Hh signaling in PF, PTCH1, a tumor suppressor protein, functions upstream of GLI1. Loss of PTCH1 induces GLI1 activation and downstream gene transcription. Utilizing fresh tissue from the index PF case, RT-qPCR analysis demonstrated expression of Hh pathway components, SMO and GLI1, as well as GLI1 transcriptional targets, CCND1 and HHIP. In turn, short-term in vitro treatment with a Hh pathway inhibitor, sonidegib, resulted in dose-dependent cell killing.ConclusionsFor the first time, we report a novel association between PTCH1 inactivation and the development of plexiform fibromyxoma. Hh pathway inhibition with SMO antagonists may represent a target to study for treating a subset of plexiform fibromyxomas

YabA of Bacillus subtilis controls DnaA-mediated replication initiation but not the transcriptional response to replication stress

yabA encodes a negative regulator of replication initiation in Bacillus subtilis and homologues are found in many other Gram-positive species. YabA interacts with the β-processivity clamp (DnaN) of DNA polymerase and with the replication initiator and transcription factor DnaA. Because of these interactions, YabA has been proposed to modulate the activity of DnaA. We investigated the role of YabA in regulating replication initiation and the activity of DnaA as a transcription factor. We found that YabA function is mainly limited to replication initiation at oriC. Loss of YabA did not significantly alter expression of genes controlled by DnaA during exponential growth or after replication stress, indicating that YabA is not required for modulating DnaA transcriptional activity. We also found that DnaN activates replication initiation apparently through effects on YabA. Furthermore, association of GFP-YabA with the replisome correlated with the presence of DnaN at replication forks, but was independent of DnaA. Our results are consistent with models in which YabA inhibits replication initiation at oriC, and perhaps DnaA function at oriC, but not with models in which YabA generally modulates the activity of DnaA in response to replication stress.United States. Public Health Service (Grant GM41934)National Institutes of Health (U.S) ( Kirschstein NRSA postdoctoral fellowship 5 F32 G-076950

Compensatory responses to insulin resistance in obese A frican‐ A merican and L atina girls

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101770/1/ijpo184.pd

Georgia Academy of Science, University of North Georgia, March 15th-16th, 2019

The annual meeting of the Georgia Academy of Science took place March 15–16, 2019, at the University of North Georgia in Oakwood. The keynote speaker was Dr. Marguerite Madden, Professor in the University of Georgia\u27s Department of Geography and Director of the Center for Geospatial Research. Her presentation was entitled Geospatial Technologies and Augmented Reality Spark Excitement in Science Education, Research and Outreach. Additional presentations were provided by members of the Academy who represented the following sections: I. Biological Sciences, II. Chemistry, III. Earth & Atmospheric Sciences, IV. Physics, Mathematics, Computer Science, Engineering, & Technology, V. Biomedical Sciences, VI. Philosophy & History of Science, VII. Science Education, and VIII. Anthropology

Barriers to using new needles encountered by rural Appalachian people who inject drugs: implications for needle exchange

Background Using a new needle for every injection can reduce the spread of infectious disease among people who inject drugs (PWID). No previous study has examined new needle use barriers among PWIDs residing in the rural Appalachian part of the United States, an area currently in the midst of a heroin epidemic. Objective Therefore, our primary aim was to explore self-reported barriers to using a new needle by PWID attending a needle exchange program (NEP). Methods We conducted a cross-sectional survey of PWID attending two NEPs in rural West Virginia located in the heart of Central Appalachia. A convenience sample of PWID (n = 100) completed the Barriers to Using New Needles Questionnaire. Results The median number of barriers reported was 5 (range 0–19). Fear of arrest by police (72% of PWID “agreed” or “strongly agreed”) and difficulty with purchasing needles from a pharmacy (64% “agreed” or “strongly agreed”) were the most frequently cited barriers. Conclusions/Importance Congruent with previous findings from urban locations, in rural West Virginia, the ability of PWID to use a new needle obtained from a needle exchange for every injection may be compromised by fear of arrest. In addition, pharmacy sales of new needles to PWID may be blunted by an absence of explicit laws mandating nonprescription sales. Future studies should explore interventions that align the public health goals of NEPs with the occupational safety of law enforcement and health outreach goals of pharmacists

Behavioural micro-dynamics of car ownership and travel in the Seattle metropolitan region from 1989 to 2002

In this paper data from 230 households observed in ten different occasions (waves) from 1989 to 2002 in the Puget Sound region are used to explore relationships among number of cars owned, number of trips driving alone, and number of trips sharing cars with household members. Using a mixture latent class Markov model we identify four distinct groups that are a High Mobility group with more cars and car trips, an Average Mobility group with lower car ownership and trips driving alone, a third group with relatively high car ownership but few car sharing trips, and a fourth group of Low Mobility characterized by the low car ownership and trips. Households change behaviour adapting to internal and external changes to their environment but they also anticipate changes and go through a "preparation" stage (e.g., adding another car in their fleet in expectation of adding another employed person). Land use plays a somewhat secondary role. The analysis also reveals three classes (hidden Markov chains) of households underlying behavioural dynamics with increases in the low car ownership categories (zero and one car per household), decreases in the high car ownership (three cars and four or more cars per household) and stable behaviour in the two cars per household group. Household membership in these classes is significantly influenced by householder ratings to parking availability, schedule flexibility, bus transfers, and day-to-day costs of driving. The findings here show attitudes and land use enhance understanding of longitudinal heterogeneity

Qualitative case study of needle exchange programs in the Central Appalachian region of the United States

Background The Central Appalachian region of the United States is in the midst of a hepatitis C virus epi- demic driven by injection of opioids, particularly heroin, with contaminated syringes. In response to this epidemic, several needle exchange programs (NEP) have opened to pro- vide clean needles and other supplies and services to people who inject drugs (PWID). How- ever, no studies have investigated the barriers and facilitators to implementing, operating, and expanding NEPs in less populous areas of the United States. Methods This qualitative case study consisted of interviews with program directors, police chiefs, law enforcement members, and PWID affiliated with two NEPs in the rural state of West Virginia. Interview transcripts were coded inductively and analyzed using qualitative data analysis software. Final common themes related to barriers and facilitators of past program open- ings, current program operations, and future program plans, were derived through a consen- sus of two data coders. Results Both NEPs struggled to find existing model programs, but benefited from broad community support that facilitated implementation. The largest operational barrier was the legal conun- drum created by paraphernalia laws that criminalize syringe possession. However, both PWID and law enforcement appreciated the comprehensive services provided by these pro- grams. Program location and transportation difficulties were additional noted barriers. Future program operations are threatened by funding shortages and bans, but necessitated by unexpected program demand. Conclusion Despite broad community support, program operations are threatened by growing partici- pant volumes, funding shortages, and the federal government’s prohibition on the use of funds to purchase needles. Paraphernalia laws create a legal conundrum in the form of criminal sanctions for the possession of needles, which may inadvertently promote needle sharing and disease transmission. Future studies should examine additional barriers to using clean needles provided by rural NEPs that may blunt the effectiveness of NEPs in pre- venting disease transmission