Farnesol secretion as a possible driving force for maintaining \u3ci\u3eCandida albicans\u3c/i\u3e as a diploid

Candida albicans is a pathogenic dimorphic fungus which is invariably found as a diploid in patients. C. albicans secretes the sesquiterpene farnesol both as a quorum sensing molecule which blocks the yeast to hypha conversion and as a virulence factor for pathogenicity. 20-25 μM farnesol kills other competing yeasts and fungi, often by triggering apoptosis, and yet wild type diploid C. albicans tolerates 300-500 μM farnesol. The recent availability of 10 haploid strains of C. albicans (5 mating type aand 5 mating type α) allowed us to compare their production of and sensitivity to farnesol. On average, the heterozygous diploid strains of C. albicans were 2.4 times more resistant to 20-40 μM farnesol than MTLa haploid cells and 4.6 times more resistant than MTLα haploid cells. Furthermore, the MTLa haploids produce approximately 10 times more farnesol than do the MTLα haploids. Prior work concluded that haploid strains exhibited such low fitness that C. albicans was thought to be an obligate diploid. We now suggest that increased farnesol secretion by the MTLa haploids and increased farnesol sensitivity of the MTLα haploids is a mechanism for maintaining the dominant heterozygous diploid status of C. albicans. This idea is based on the observation that the a-factor peptide pheromone is farnesylated but the α-factor pheromone is not farnesylated. Our working hypothesis is that farnesol is secreted in part via Ste6 and imported in part via Ste3, the proteins which export and import the farnesylated a-pheromone. We also examined whether farnesol was excreted in extracellular vesicles

Microstructural evolution of environmental barrier coatings in high-temperature steam

Environmental Barrier Coatings (EBCs) are required for use of SiC-based composites in hot sections of gas turbine engines. The primary function of EBCs is to limit the interaction of SiC with steam in the combustion environment. Due to the additional constraints of thermal expansion match and chemical compatibility with the SiC substrate, state-of-the art EBCs are typically fabricated from complex silicates. These silicates typically have sufficiently high silica activities that they also react with the steam by the following generic reaction. Please click Additional Files below to see the full abstract

Homeless Negotiations of Public Space in Two California Cities

People experiencing homelessness find movement in urban public space constrained. Scholars have attributed this lack of accessibility to the consequences of anti-homeless laws, social exclusions and economic factors. I draw from spatial and mobility theory to frame movement and transgression within the partitioned city. I accompanied homeless people on walking interviews to discuss their movements, transgressions, and public space they occupied. I also mapped people’s behavior in public space, comparing the movements of homeless people with the movements of people with homes. The results indicate homeless people negotiate urban space by walking, biking and riding the bus in a manner that maximizes their ability to manage relationships as they travel. Constraints in movement arise from the partitioning of the city, i.e. the division into public and private, making it difficult to both rest in public space and move in socially-acceptable manners. The findings suggest cities can improve homeless movement through setting limits on the automobile and removing limits (or partitions) on informal patterns of movement

KSU Philharmonic and Concert Band

KSU School of Music presents Philharmonic and Concert Band.https://digitalcommons.kennesaw.edu/musicprograms/1113/thumbnail.jp

Cone beam neutron interferometry: from modeling to applications

Phase-grating moire interferometers (PGMIs) have emerged as promising candidates for the next generation of neutron interferometry, enabling the use of a polychromatic beam and manifesting interference patterns that can be directly imaged by existing neutron cameras. However, the modeling of the various PGMI configurations is limited to cumbersome numerical calculations and backward propagation models which often do not enable one to explore the setup parameters. Here we generalize the Fresnel scaling theorem to introduce a k-space model for PGMI setups illuminated by a cone beam, thus enabling an intuitive forward propagation model for a wide range of parameters. The interference manifested by a PGMI is shown to be a special case of the Talbot effect, and the optimal fringe visibility is shown to occur at the moire location of the Talbot distances. We derive analytical expressions for the contrast and the propagating intensity profiles in various conditions, and analyze the behaviour of the dark-field imaging signal when considering sample characterization. The model's predictions are compared to experimental measurements and good agreement is found between them. Lastly, we propose and experimentally verify a method to recover contrast at typically inaccessible PGMI autocorrelation lengths. The presented work provides a toolbox for analyzing and understanding existing PGMI setups and their future applications, for example extensions to two-dimensional PGMIs and characterization of samples with non-trivial structures

#35 - Enamel isotopes reveal late Pleistocene ecosystem dynamics in southeastern North America

The end of the late Pleistocene (~10,000 years ago) witnessed the extinction of over seventy percent of North America’s megafaunal genera. Although this pattern has been extensively investigated, its causal mechanisms remain elusive. Much of this difficulty is related to the spatial and temporal discontinuity of sites dating to the period leading up to the extinctions. Due to its removal from glacial conditions, southeastern North America provides a unique window into ecosystem dynamics just prior to human arrival in the region. In this study, we present new stable carbon and oxygen isotope data from Mammuthus columbiand Bison latifronsteeth collected from a well-dated Last Glacial Maximum (~20,000 rcybp) locality called Clark Quarry in coastal Georgia, USA. We compare these data to those from similarly aged (middle and late Rancholabrean) localities from Florida and demonstrate the presence of a vegetation gradient with elevated levels of C3vegetation at higher latitudes. We hypothesize that this pattern may have contributed to previously described migratory patterns of mastodon (Mammut) populations in southeastern North America. Serially-sampled δ13C and δ18O values suggest that Clark Quarry Mammuthus and Bison changed their diet seasonally with the incorporation of elevated quantities of C4vegetation during warmer periods. Our data indicate more exaggerated seasonal dietary variability in these taxa at Clark Quarry relative to those collected from the interglacial locality of Waccasassa River in Florida, providing additional evidence for the significant influence of glacial dynamics in structuring North American ecosystems

Efficient factorization with a single pure qubit and logN mixed qubits.

Published versio

The Burden of Skin and Subcutaneous Diseases in the United States From 1990 to 2017

IMPORTANCE Skin and subcutaneous diseases affect the health of millions of individuals in the US. Data are needed that highlight the geographic trends and variations of skin disease burden across the country to guide health care decision-making. OBJECTIVE To characterize trends and variations in the burden of skin and subcutaneous tissue diseases across the US from 1990 to 2017. DESIGN, SETTING, AND PARTICIPANTS For this cohort study, data were obtained from the Global Burden of Disease (GBD), a study with an online database that incorporates current and previous epidemiological studies of disease burden, and from GBD 2017, which includes more than 90 000 data sources such as systematic reviews, surveys, population-based disease registries, hospital inpatient and outpatient data, cohort studies, and autopsy data. The GBD separated skin conditions into 15 subcategories according to incidence, prevalence, adequacy of data, and standardized disease definitions. GBD 2017 also estimated the burden from melanoma of the skin and keratinocyte carcinoma. Data analysis for the present study was conducted from September 9, 2019, to March 31, 2020. MAIN OUTCOMES AND MEASURES Primary study outcomes included age-standardized disability-adjusted life-years (DALYs), incidence, and prevalence. The data were stratified by US states with the highest and lowest age-standardized DALY rate per 100 000 people, incidence, and prevalence of each skin condition. The percentage change in DALY rates in each state was calculated from 1990 to 2017. RESULTS Overall, age-standardized DALY rates for skin and subcutaneous diseases increased from 1990 (821.6; 95% uncertainty interval [UI], 570.3-1124.9) to 2017 (884.2; 95% UI, 614.0-1207.9) in all 50 states and the District of Columbia. The degree of increase varied according to geographic location, with the largest percentage change of 0.12% (95% UI, 0.09%-0.15%) in New York and the smallest percentage change of 0.04% (95% UI, 0.02%-0.07%) in Colorado, 0.04% (95% UI, 0.01%-0.06%) in Nevada, 0.04% (95% UI, 0.02%-0.07%) in New Mexico, and 0.04% (95% UI, 0.02%-0.07%) in Utah. The age-standardized DALY rate, incidence, and prevalence of specific skin conditions differed among the states. New York had the highest age-standardized DALY rate for skin and subcutaneous disease in 2017 (1097.0 [95% UI, 764.9-1496.1]), whereas Wyoming had the lowest age-standardized DALY rate (672.9 [95% UI, 465.6-922.3]). In all 50 states and the District of Columbia, women had higher age-standardized DALY rates for overall skin and subcutaneous diseases than men (women: 971.20 [95% UI, 676.76-1334.59] vs men: 799.23 [95% UI, 559.62-1091.50]). However, men had higher DALY rates than women for malignant melanoma (men: 80.82 [95% UI, 51.68-123.18] vs women: 42.74 [95% UI, 34.05-70.66]) and keratinocyte carcinomas (men: 37.56 [95% UI, 29.35-49.52] vs women: 14.42 [95% UI, 10.01-20.66]). CONCLUSIONS AND RELEVANCE Data from the GBD suggest that the burden of skin and subcutaneous disease was large and that DALY rate trends varied across the US; the age-standardized DALY rate for keratinocyte carcinoma appeared greater in men. These findings can be used by states to target interventions and meet the needs of their population

Design, construction, and characterization of a compact DD neutron generator designed for 40Ar/39Ar geochronology

A next-generation, high-flux DD neutron generator has been designed, commissioned, and characterized, and is now operational in a new facility at the University of California Berkeley. The generator, originally designed for 40Ar/39Ar dating of geological materials, has since served numerous additional applications, including medical isotope production studies, with others planned for the near future. In this work, we present an overview of the High Flux Neutron Generator (HFNG) which includes a variety of simulations, analytical models, and experimental validation of results. Extensive analysis was performed in order to characterize the neutron yield, flux, and energy distribution at specific locations where samples may be loaded for irradiation. A notable design feature of the HFNG is the possibility for sample irradiation internal to the cathode, just 8 mm away from the neutron production site, thus maximizing the neutron flux (n/cm2/s). The generator's maximum neutron flux at this irradiation position is 2.58e7 n/cm2/s +/- 5% (approximately 3e8 n/s total yield) as measured via activation of small natural indium foils. However, future development is aimed at achieving an order of magnitude increase in flux. Additionally, the deuterium ion beam optics were optimized by simulations for various extraction configurations in order to achieve a uniform neutron flux distribution and an acceptable heat load. Finally, experiments were performed in order to benchmark the modeling and characterization of the HFNG.Comment: 31 pages, 20 figure