Characterization of cyclic-di-GMP signaling with the Lyme spirochete, Borrelia burgdorferi

Lyme disease is a tick-borne infection caused by Borrelia burgdorferi, B. garinii, and B. afzelii. These spirochetes experience environmental fluctuations as they are passed between mammalian and Ixodes tick hosts throughout their enzootic cycle. Recent studies have suggested cyclic diguanylate (c-di-GMP), a ubiquitous secondary messenger, is a key modulator of B. burgdorferi adaptive responses and may play a significant role in cycle progression. In this study, we examined the impact of the sole diguanylate cyclase (Rrp1), c-di-GMP binding proteins (PlzA and PlzB), and HD-GYP-containing phosphodiesterase (PdeB) in disease establishment of both murine and Ixodes tick systems. Strains harboring targeted gene deletions or plasmid-based constitutive gene expression constructs were generated. Rrp1 was required for tick colonization, yet overexpression abolished murine disease, thus implicating the requirement of finely regulated c-di-GMP levels for enzootic cycle progression. Deletion of rrp1 disrupted translational motion and swarming patterns by causing extended cell runs, eliminating stops/flexes, and reducing swarming capabilities. This was attributed to a defect in N-acetyl-D-glucosamine (NAG) metabolism and chemotaxis. NAG is a major source of nutrition for B. burgdorferi within the tick environment; therefore this defect would impede spirochete migration towards feeding ticks, as well as pathogen uptake and survival within the Ixodes vector. In contrast, the downstream c-di-GMP effector, PlzA, was critical for murine disease but nonessential for survival within ticks nor functionally complemented by PlzB. Deletion of plzA altered strain motility and swarming similarly to the rrp1 deletion mutant, yet had a distinct phenotype with significantly slower translational motion and no affect on NAG chemotaxis and metabolism. This indicates B. burgdorferi could possess alternate c-di-GMP effectors or Rrp1 could be directly influencing these cellular processes. Uniquely, PdeB did not abolish murine infection via needle inoculation, but wasrequired for natural transmission from ticks. This defect was linked to the decreased tick colonization efficiency upon pdeB deletion. Together, these analyses indicate that c-di-GMP signaling is an important virulence mechanism of Borrelia burgdorferi and demonstrate the complexity of this signaling pathway in an arthropod-borne pathogen. The data presented here additionally provide significant new insight into the gene regulatory mechanisms of the Lyme disease spirochetes

The Social Structure of the First Crusade

This books provides a detailed analysis of the social structure of the First Crusade (1096 – 1099) along with an original assessment of the sociology of its contemporary or near contemporary sources

Test Your Knowledge: STI Questionnaire and Education

Project aims to improve education concerning sexually transmitted infections (STIs) in the teenage patient population of Springfield Health Center Family Practice. Teenage patients were found to only cite pregnancy prevention, and not STI prevention, when asked by medical providers why they should use condoms.https://scholarworks.uvm.edu/fmclerk/1239/thumbnail.jp

Instrumental music in the Boston public schools

This item was digitized by the Internet Archive. Thesis (M.A.)--Boston Universityhttps://archive.org/details/instrumentalmusi00kos

Chapter 1 Cowboys, Cod, Climate, and Conflict

The DEH can be seen as an academic response to three major interwoven changes and challenges: the digital revolution; global warming and global warming and social-political agency related to environmental change. In the twenty-first century, we are challenged with a transformation in human collective intelligence. The key features of this transformation involve the “digital” replacing the “analogue”; design thinking and post-secularism supplanting tradition; and human agency emerging as the main driver of planetary change. Unlocking the keys to human perception, mitigating behavior and adaptive action may likely rank among the preeminent challenges we face in an age witnessing unprecedented rates of global change. The chapter showcases how the DEH is being applied by three international funded research projects: Larry McMurtry’s Literary Geography; NorFish (Environmental History of the North Atlantic Fisheries, 1500-1800); and the Climates of Conflict in Babylonia project

Leaf morphological and genetic variation between Quercus rubra and Quercus ellipsoidalis: comparison of sympatric and parapatric populations

Species boundaries in oaks are often not clear-cut, which is potentially a result of interspecific hybridization with trait introgression and phenotypic plasticity. Quercus rubra L. and Quercus ellipsoidalis E.J. Hill are two interfertile partially sympatric red oak species (section Lobatae) with different adaptations to drought. Quercus ellipsoidalis is the most drought tolerant of the North American red oak species and is characterized by deep tap roots, a shrubby growth and by deeply dissected leaves. Genetic differentiation between species is low for most molecular markers. However, one genic microsatellite in a CONSTANS-like (COL) gene, FIR013, was previously identified as outlier locus under strong divergent selection between species. In this study, we analyzed leaf morphometric traits in neighboring (parapatric) Q. rubra/Q. ellipsoidalis populations and in one sympatric population from the same region along an environmental gradient. Using multivariate statistics of leaf traits both species showed distinct bimodal frequency distributions for the first canonical discriminant function with some overlap in the phenotypic extremes, especially in the sympatric population. Leaf dissection traits showed strong and consistent differentiation between species in sympatric and parapatric populations, while differentiation for leaf size was lower in the sympatric population under more similar environmental conditions. Leaf phenotypes in F1 hybrids and introgressive forms suggested maternal effects and introgression of leaf traits between species. The association of outlier gene copy number at FIR013 with species-discriminating leaf traits in Quercus rubra can be a reflection of population differences since outlier gene copy number and population membership show significant collinearity. Similar environmental selection pressures on outlier alleles and leaf shape could also have resulted in this association. In future studies, segregating full-sib families could be used to test whether outlier alleles and associated genomic regions are indeed associated with leaf traits or other species-discriminating characters

Comprehensive Field Evaluation of Asphalt Patching Methods and Development of Simple Decision Trees and a Best Practices Manual

The long-term performance of pothole patches largely depends on the selection of the patching method. A number of pothole patching methods are in practice in Minnesota and other nearby states. However, pavement maintenance crews often encounter problems in selecting the most appropriate patching method because proper guidelines are not available. The objective of this project was to investigate the effectiveness of different pavement patching methods and to develop simple decision trees and a best practices manual. The performance of 20 different pothole patches, which were patched with four different types of patching methods and located at five different construction sites, were monitored for approximately two years. Based on the observed performance of the pothole patches considered in this study, two forms of decision trees and a best practices manual have been developed for selecting the most appropriate patching method for a given pothole condition. The developed decision trees can be used to select the patching method based on the location of the pothole (e.g., along longitudinal joints, localized potholes, etc.), construction season, condition of the pothole, and pothole area and depth. The best practices manual provides guidelines on the selection of patching method, pothole preparation, placement of patching materials, and compaction

Socially-critical software systems: Is extended regulation required?

Data has become a prevailing aspect of our daily lives, becoming ever more present since the beginning of the 21st century. It is a commodity in today’s world and the amount of data being produced has increased enormously. One of the major ways data is produced and collected is from the use of websites and web-based applications. This data is later used for many different purposes. This paper presents findings from a multivocal literature review, exploring the methods of how this data is collected, what the data is used for once it has been collected, the ethics of data and its collection, and the future of data collection. Among the possible futures, we introduce the concept of socially-critical applications, where data harvesting in web-based applications might require premarket disclosure and evaluation by notified bodies (instructed by regulation) as a means to break the existing cycle of technology companies outpacing under resourced and ill-equipped regulators. Rather than regulators continually falling short of enacting laws to satisfy the common good, a new class of socially-critical application could be created in law to permit pre-market evaluation of applications (or versions of applications) that could undermine or interrupt the common good