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What was the impact of faculty learning from and with colleagues? An assessment of faculty professional development program sessions August 2013-February 2014
Get PDFThe professional literature suggests five levels of evaluation for faculty development programs. FPDP resource session participation was tracked through registration and attendance. Following the sessions participants were provided with a link to anonymous online evaluations with six Likert-scale items and three open-ended questions. A brief year-end survey will be sent to all participants in the 2013-14 resource sessions to further assess the systemic impact of the year’s programs
A high angular resolution survey of massive stars in Cygnus Ob2: Results from the Hubble Space Telescope fine guidance sensors
Get PDFWe present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the fine guidance sensor 1R (FGS1r) on the Hubble Space Telescope. FGS1r is able to resolve binary systems with a magnitude difference Delta V 60%. One of the new discoveries is a companion to the hypergiant star MT 304 = Cyg OB2-12, and future measurements of orbital motion should provide mass estimates for this very luminous star
Dynamic lithosphere within the Great Basin
Get PDFTo place new constraints on the short-term, broad-scale lithospheric evolution of plate interiors, we utilize broadband seismic data from the Great Basin region of the Western United States to produce high-resolution images of the crust and upper mantle. Our results suggest that parts of the Great Basin lithosphere has been removed, likely via inflow of hot asthenosphere as subduction of the Farallon spreading center occurred and the region extended. In our proposed model, fragments of thermal lithosphere removed by this process were gravitationally unstable and subsequently sank into the underlying mantle, leaving behind less dense, stronger, chemically depleted lithosphere. This destabilization process promotes volcanism, deformation, and the reworking of continental lithosphere inboard from plate margins. Our results provide evidence for a new mechanism of lithospheric evolution that is likely common and significant in postsubduction tectonic settings
Fact Sheet: Summer Habitat Use by Adult Female Mule Deer in a Restoration-Treated Ponderosa Pine Forest.
Get PDFMule deer (Odocoileus hemionus) populations in the Southwest have experienced declines in the past 50 years due to habitat degradation from fire suppression, exotic species invasion, and increased livestock grazing. Habitat requirements of mule deer include an abundance of high-quality herbaceous forage, vegetation cover that provides protection from predators and weather, and access to reliable water sources. Summer forage availability and quality affects doe productivity and lactation, and fawn survival and growth prior to a resource-limited winter; therefore, high-quality summer habitat is essential for maintaining healthy populations. In northern Arizona, mule deer summer home ranges commonly include ponderosa pine-dominated vegetation types, including extensive areas where large-scale restoration treatments have been implemented or are currently being planned. Restoration treatments that open tree canopies in ponderosa pine and mixed-conifer forests often increase forage abundance and diversity and subsequent use by mule deer; however, these treatments may also reduce hiding cover and alter the microclimate and physical characteristics of day-bed sites. In this study, we sought to examine the effects of forest restoration on the relative intensity of summer habitat-use patterns of mule deer. Our objectives were to 1) spatially define individual home range and core areas, 2) develop a spatially explicit statistical model of intensity of habitat use, and 3) make recommendations that will help land managers provide essential forage and cover attributes for mule deer while restoring forest structure and reducing the risk of uncharacteristic, high-intensity wildfire
Fact sheet: Characterizing spatial reference conditions in southwestern warm/dry mixed-conifer forests
Get PDFReference conditions describe attributes of ecosystem structure, composition, and function and are used to inform ecological restoration efforts. Reference condition information on tree spatial patterns that occurred prior to wide-spread fire exclusion is limited for warm/dry mixed-conifer forests of the western U.S. (Romme et al. 2009), particularly those in the Southwest (see Table 1). Spatial patterns of trees, and groups of trees, are important because they are known to influence understory biodiversity and productivity, fire behavior, distribution of surface fuels, wildlife habitat value, and regeneration (North et al. 2007, Sanchez Meador et al. 2009, Fry and Stephens 2010), yet this information is rarely quantified. The purpose of this fact sheet is to provide an overview of the existing research on spatial patterns in warm/dry mixed-conifer forests, and provide recommendations of future research
How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?
Get PDFA better understanding of ecosystem water-use efficiency (WUE) will help us improve ecosystem management for mitigation as well as adaption to global hydrological change. Here, long-term flux tower observations of productivity and evapotranspiration allow us to detect a consistent latitudinal trend in WUE, rising from the subtropics to the northern high-latitudes. The trend peaks at approximately 51°N, and then declines toward higher latitudes. These ground-based observations are consistent with global-scale estimates of WUE. Global analysis of WUE reveals existence of strong regional variations that correspond to global climate patterns. The latitudinal trends of global WUE for Earth's major plant functional types reveal two peaks in the Northern Hemisphere not detected by ground-based measurements. One peak is located at 20° ~ 30°N and the other extends a little farther north than 51°N. Finally, long-term spatiotemporal trend analysis using satellite-based remote sensing data reveals that land-cover and land-use change in recent years has led to a decline in global WUE. Our study provides a new framework for global research on the interactions between carbon and water cycles as well as responses to natural and human impacts
MetaGeniE: Characterizing human clinical samples using deep metagenomic sequencing
Get PDFWith the decreasing cost of next-generation sequencing, deep sequencing of clinical samples provides unique opportunities to understand host-associated microbial communities. Among the primary challenges of clinical metagenomic sequencing is the rapid filtering of human reads to survey for pathogens with high specificity and sensitivity. Metagenomes are inherently variable due to different microbes in the samples and their relative abundance, the size and architecture of genomes, and factors such as target DNA amounts in tissue samples (i.e. human DNA versus pathogen DNA concentration). This variation in metagenomes typically manifests in sequencing datasets as low pathogen abundance, a high number of host reads, and the presence of close relatives and complex microbial communities. In addition to these challenges posed by the composition of metagenomes, high numbers of reads generated from high-throughput deep sequencing pose immense computational challenges. Accurate identification of pathogens is confounded by individual reads mapping to multiple different reference genomes due to gene similarity in different taxa present in the community or close relatives in the reference database. Available global and local sequence aligners also vary in sensitivity, specificity, and speed of detection. The efficiency of detection of pathogens in clinical samples is largely dependent on the desired taxonomic resolution of the organisms. We have developed an efficient strategy that identifies “all against all” relationships between sequencing reads and reference genomes. Our approach allows for scaling to large reference databases and then genome reconstruction by aggregating global and local alignments, thus allowing genetic characterization of pathogens at higher taxonomic resolution. These results were consistent with strain level SNP genotyping and bacterial identification from laboratory culture
High frequency, spontaneous motA mutations in Campylobacter jejuni strain 81-176
Get PDFCampylobacter jejuni is an important cause of bacterial diarrhea worldwide. The pathogenesis of C. jejuni is poorly understood and complicated by phase variation of multiple surface structures including lipooligosaccharide, capsule, and flagellum. When C. jejuni strain 81-176 was plated on blood agar for single colonies, the presence of translucent, non-motile colonial variants was noted among the majority of opaque, motile colonies. High-throughput genomic sequencing of two flagellated translucent and two opaque variants as well as the parent strain revealed multiple genetic changes compared to the published genome. However, the only mutated open reading frame common between the two translucent variants and absent from the opaque variants and the parent was motA, encoding a flagellar motor protein. A total of 18 spontaneous motA mutations were found that mapped to four distinct sites in the gene, with only one class of mutation present in a phase variable region. This study exemplifies the mutative/adaptive properties of C. jejuni and demonstrates additional variability in C. jejuni beyond phase variation
Phylogeography of Bacillus anthracis in the country of Georgia shows evidence of population structuring and is dissimilar to other regional genotypes
Get PDFSequence analyses and subtyping of Bacillus anthracis strains from Georgia reveal a single distinct lineage (Aust94) that is ecologically established. Phylogeographic analysis and comparisons to a global collection reveals a clade that is mostly restricted to Georgia. Within this clade, many groups are found around the country, however at least one subclade is only found in the eastern part. This pattern suggests that dispersal into and out of Georgia has been rare and despite historical dispersion within the country, for at least for one lineage, current spread is limited
Sub-inhibitory fosmidomycin exposures elicits oxidative stress in Salmonella enterica Serovar typhimurium LT2
Get PDFFosmidomycin is a time-dependent nanomolar inhibitor of methylerythritol phosphate (MEP) synthase, which is the enzyme that catalyzes the first committed step in the MEP pathway to isoprenoids. Importantly, fosmidomycin is one of only a few MEP pathway-specific inhibitors that exhibits antimicrobial activity. Most inhibitors identified to date only exhibit activity against isolated pathway enzymes. The MEP pathway is the sole route to isoprenoids in many bacteria, yet has no human homologs. The development of inhibitors of this pathway holds promise as novel antimicrobial agents. Similarly, analyses of the bacterial response toward MEP pathway inhibitors provides valuable information toward the understanding of how emergent resistance may ultimately develop to this class of antibiotics. We have examined the transcriptional response of Salmonella enterica serovar typhimurium LT2 to sub-inhibitory concentrations of fosmidomycin via cDNA microarray and RTPCR. Within the regulated genes identified by microarray were a number of genes encoding enzymes associated with the mediation of reactive oxygen species (ROS). Regulation of a panel of genes implicated in the response of cells to oxidative stress (including genes for catalases, superoxide dismutases, and alkylhydrogen peroxide reductases) was investigated and mild upregulation in some members was observed as a function of fosmidomycin exposure over time. The extent of regulation of these genes was similar to that observed for comparable exposures to kanamycin, but differed significantly from tetracycline. Furthermore, S. typhimurium exposed to sub-inhibitory concentrations of fosmidomycin displayed an increased sensitivity to exogenous H2O2 relative to either untreated controls or kanamycin-treated cells. Our results suggest that endogenous oxidative stress is one consequence of exposures to fosmidomycin, likely through the temporal depletion of intracellular isoprenoids themselves, rather than other mechanisms that have been proposed to facilitate ROS accumulation in bacteria (e.g. cell death processes or the ability of the antibiotic to redox cycle)