Targeted Mutagenesis of the Oligopeptide Repeat Domain of the Yeast Prion Sup35

The formation of prions in the baker’s yeast Saccharomyces cerevisiae is determined by amino acid composition rather than the primary sequence of amino acids. The infectious amyloid proteins known as prions undergo nucleation and propagation, two distinct activities critical for prion formation. The ability for prions to be transferred from cell to cell, or propagate, is of interest not only in yeast prions but also in prion diseases such as the mammalian spongiform encephalopathies. Prion formation has been widely studied in yeast prions, however, the fundamental mechanisms behind the specific process of propagation of prions from cell to cell are not yet understood. In the most well-studied yeast prion, the prion form [PSI+] of Sup35, a domain of 5 ½ degenerate oligopeptide repeats called the oligopeptide repeat domain (ORD) has been shown to be important for prion propagation and to have a distinct amino acid composition as compared to the nucleation domain region. A library mutagenesis experiment has identified amino acids that favor or disfavor prion propagation in yeast cells. To confirm the results of the random library mutagenesis experiment, we generated several clones in which a portion of the ORD (the fourth oligopeptide repeat) was replaced with defined sequences expected to propagate or fail to propagate

Mapping the Beta-Sheet Structure of the Yeast Prion Sup35 through Creation of Targeted Mutant Forms

Proteins with an aggregated form rich in beta-sheet structure are known as amyloids, of which a subset are infectious. These infectious proteins are known as prions and cause diseases including bovine spongiform encephalopathy (“Mad Cow” disease). Several prions have been identified in the baker’s yeast, Saccharomyces cerevisiae. One of the most well-studied yeast prions is the protein Sup35. To understand the fine protein structure of Sup35 better, we used PCR-based mutagenesis to introduce a lysine residue (a charged amino acid) at five defined places in the protein sequence of Sup35. We describe our process for creating these mutant versions and the results of DNA sequencing of each mutant version. The next step will be to assess prion formation and stability of clones with the correct sequences. Understanding the behavior of yeast prions has proven helpful in understanding human amyloid diseases and further studies on these yeast prions, including Sup35, will expand our knowledge further

Fort Worth Zoo Creek Drainage Improvements Project Tarrant County, Texas

The City of Fort Worth is proposing to construct storm drainage improvements along Zoo Creek in Tarrant County, Texas. The project area is located in the southern 10.5 acres of Forest Park in central Fort Worth. The parcel is bounded by Park Hill Drive (Dr) on the north, Sandage Avenue (Ave) on the west, McPherson Ave on the south, and McCart Ave on the east. South (S.) Forest Dr bisects the property. This project consists of the construction of a stormwater detention wall to help alleviate flooding in the area. There will be four main impact areas and portions of S. Forest Dr will be repaved. The deepest impacts will occur in the northern portion of the park where the detention wall will be built along the Park Hill Dr Bridge. The second impact area will be for the new sanitary sewer being rerouted along McCart Ave. The third is the replacement of a low water crossing culvert on S. Forest Dr near the central part of the parcel. The final impact will be for a stormwater outfall on Zoo Creek to be constructed on the south end of the park where the creek intersects McPherson Ave. A 30-meter area around all four impact areas was surveyed for a total of 1.72 acres. The purpose of this investigation was to determine if significant cultural resources are present in the proposed impact areas as part of the Section 106 process. The area had potential for both historic and prehistoric resources. Ten negative shovel tests were excavated throughout the survey areas. Two historic-age resources were recorded as archaeological sites and evaluated by an architectural historian. Site 41TR306 is a historic culvert on S. Forest Dr. This culvert will be replaced and is not recommended eligible for listing on the National Register of Historic Places or as a State Antiquities Landmark. Site 41TR307, is a park shelter over 50 meters outside the culvert’s direct impact area. The structure will not be impacted, but is recommended as eligible. No other cultural resources were identified on or below the surface during the survey. Based on the results of the survey, AR Consultants, Inc. concludes that further cultural resource investigations for this project are unwarranted, and requests that the Texas Historical Commission and the U.S. Army Corps of Engineers concur with this recommendation. However, if buried cultural materials are discovered during construction, both agencies should be notified. Work should not resume until all coordination with agencies is completed. The project will be curated with the Center for Archaeological Studies at Texas State University

One- and two-axis squeezing of atomic ensembles in optical cavities

The strong light-matter coupling attainable in optical cavities enables the generation of highly squeezed states of atomic ensembles. It was shown in [Phys. Rev. A 66, 022314 (2002)] how an effective one-axis twisting Hamiltonian can be realized in a cavity setup. Here, we extend this work and show how an effective two-axis twisting Hamiltonian can be realized in a similar cavity setup. We compare the two schemes in order to characterize their advantages. In the absence of decoherence, the two-axis Hamiltonian leads to more squeezing than the one-axis Hamiltonian. If limited by decoherence from spontaneous emission and cavity decay, we find roughly the same level of squeezing for the two schemes scaling as (NC)^(1/2) where C is the single atom cooperativity and N is the total number of atoms. When compared to an ideal squeezing operation, we find that for specific initial states, a dissipative version of the one-axis scheme attains higher fidelity than the unitary one-axis scheme or the two-axis scheme. However, the unitary one-axis and two-axis schemes perform better for general initial states.Comment: 13 pages, 6 figure

Eagle Mountain To Big Fossil Creek Diversion Tarrant, County, Texas

The City of Fort Worth is proposing to construct the Eagle Mountain to Big Fossil Diversion Pipeline in northern Tarrant County. Alan Plummer Associates, Inc. is handling the environmental permitting for the construction of the pipeline. AR Consultants, Inc. was contracted to conduct a cultural resource survey, which included archival research, to determine the presence of prehistoric and historic archaeological sites along the route and make recommendations about eligibility for the National Register of Historic Places (NRHP) and State Antiquities Landmark (SAL) designation. Four survey areas were identified, totaling approximately 3.1 kilometers of the approximately 9-km-long route. The westernmost survey area of the pipeline crosses Dosier Creek on the northside of Boat Club Road. The central segment out of the four survey areas is parallel to Park Drive and was investigated due to the presence of structures shown on historic maps within the 100-foot survey corridor. The longest segment in the east is parallel an intermittent tributary flowing northeast into Big Fossil Creek, while the final survey area approaches Big Fossil Creek in its floodplain. Survey of the approximately 25 acres was conducted on January 09, 2018. One site, 41TR309, was recorded and represents the remains of a historic farmstead. The site is not recommended eligible for NRHP or SAL. No other cultural resources were identified on or below the surface during the survey. Based on the results of the survey, ARC concludes that further cultural resource investigations for this project are unwarranted, and requests that the Texas Historical Commission (THC) concur with this recommendation. However, if buried cultural materials are discovered during construction, the Archeology Division of the THC should be notified. The records will be curated at the Center for Archaeological Studies at Texas State University in San Marcos

Archeological Survey Of The Proposed Sanger Outfall Pipeline Denton County, Texas

The City of Sanger is proposing to construct the 3.06-kilometer-long Sanger Outfall Pipeline in Denton County, Texas. Alan Plummer Associates, Inc. contracted with AR Consultants, Inc. to survey a 100-foot-wide corridor along the proposed route. AR Consultants, Inc. hypothesized that there would be low potential for both prehistoric and historic cultural resources. These hypotheses were based on the location of the pipeline route in the narrow Ranger Branch floodplain and lack of mapped historic structures remaining in the project area. Fieldwork was conducted on May 31, 2018 under Texas Antiquities permit 8338, during which 19 shovel tests were excavated and a total of 11 acres were surveyed. No historic or prehistoric cultural resources were noted within the survey corridor. As such, AR Consultants, Inc. recommends that no further cultural resource investigations are necessary for this project, and requests that the Texas Historical Commission concur with this recommendation. Project documents will be curated at the Center for Archaeological Studies, Texas State University, San Marcos

Osteocytic connexin 43 is not required for the increase in bone mass induced by intermittent PTH administration in male mice

Objective: To investigate whether osteocytic connexin 43 (Cx43) is required for the bone response to intermittent PTH administration, and whether the connexin is involved in maintaining the bone matrix. Methods: Human PTH(1-34) was injected to adult male mice expressing (Cx43fl/fl) or not osteocytic Cx43 (Cx43fl/fl;DMP1-8kb-Cre) daily (100 μg/kg/d) for 14 days. Results: Cx43fl/fl;DMP1-8kb-Cre mice have no difference in body weight and BMD from 1 to 4 months of age. Intermittent PTH administration increased BMD and BV/TV and induced a similar increase in type I collagen, alkaline phosphatase, runx2, osteocalcin, and bone sialoprotein expression in mice from both genotypes. On the other hand, osteocytic deletion of Cx43 did not alter mRNA levels of glycosaminoglycans, proteoglycans, collagens and osteoblast-related genes. In addition, expression of collagens assessed by immunohistochemistry was not affected by deleting osteocytic Cx43. However, PTH administration increased type II collagen only in Cx43fl/fl control mice, whereas hormone increased type I collagen expression only in Cx43fl/fl;DMP1-8kb-Cre mice. Furthermore, PTH increased maturity of collagen fibers in control, but not in Cx43-deficient mice. Conclusion: Expression of Cx43 in osteocytes is dispensable for bone anabolism induced by intermittent PTH administration; but it can modulate, at least in part, the effect of PTH on the bone matrix environment

Distributed subglacial discharge drives significant submarine melt at a Greenland tidewater glacier

Submarine melt can account for substantial mass loss at tidewater glacier termini. However, the processes controlling submarine melt are poorly understood due to limited observations of submarine termini. Here at a tidewater glacier in central West Greenland, we identify subglacial discharge outlets and infer submarine melt across the terminus using direct observations of the submarine terminus face. We find extensive melting associated with small discharge outlets. While the majority of discharge is routed to a single, large channel, outlets not fed by large tributaries drive submarine melt rates in excess of 3.0 m d−1 and account for 85% of total estimated melt across the terminus. Nearly the entire terminus is undercut, which may intersect surface crevasses and promote calving. Severe undercutting constricts buoyant outflow plumes and may amplify melt. The observed morphology and melt distribution motivate more realistic treatments of terminus shape and subglacial discharge in submarine melt models

Systematic Definition of Protein Constituents along the Major Polarization Axis Reveals an Adaptive Reuse of the Polarization Machinery in Pheromone-Treated Budding Yeast

Polarizing cells extensively restructure cellular components in a spatially and temporally coupledmanner along the major axis of cellular extension. Budding yeast are a useful model of polarized growth, helping to define many molecular components of this conserved process. Besides budding, yeast cells also differentiate upon treatment with pheromone from the opposite mating type, forming a mating projection (the ‘shmoo’) by directional restructuring of the cytoskeleton, localized vesicular transport and overall reorganization of the cytosol. To characterize the proteomic localization changes ac-companying polarized growth, we developed and implemented a novel cell microarray-based imaging assay for measuring the spatial redistribution of a large fraction of the yeast proteome, and applied this assay to identify proteins localized along the mating projection following pheromone treatment. We further trained a machine learning algorithm to refine the cell imaging screen, identifying additional shmoo-localized proteins. In all, we identified 74 proteins that specifically localize to the mating projection, including previously uncharacterized proteins (Ycr043c, Ydr348c, Yer071c, Ymr295c, and Yor304c-a) and known polarization complexes such as the exocyst. Functional analysis of these proteins, coupled with quantitative analysis of individual organelle movements during shmoo formation, suggests a model in which the basic machinery for cell polarization is generally conserved between processe

Letting nature do the work : managing wildfires for resource objectives in New Mexico

2 pagesIn millions of acres of fire-adapted landscapes across the West, the need for forest restoration and wildfire mitigation outpaces capacity to respond, posing risks to homes, communities, and forest health. Land managers are increasingly looking for tools to help address these risks. One approach is to manage naturally ignited wildfires at appropriate intensities and severities to reduce fuel loads and improve forest health. This fact sheet describes managing naturally ignited wildfires for resource objectives and how multiple public, private and nongovernmental entities are working on wildfire mitigation, pre-planning, and suppression in northern New Mexico to foster the necessary conditions for this approach.FUNDER: Joint Fire Science Program