Animated computer graphics models of space and earth sciences data generated via the massively parallel processor

The capability was developed of rapidly producing visual representations of large, complex, multi-dimensional space and earth sciences data sets via the implementation of computer graphics modeling techniques on the Massively Parallel Processor (MPP) by employing techniques recently developed for typically non-scientific applications. Such capabilities can provide a new and valuable tool for the understanding of complex scientific data, and a new application of parallel computing via the MPP. A prototype system with such capabilities was developed and integrated into the National Space Science Data Center's (NSSDC) Pilot Climate Data System (PCDS) data-independent environment for computer graphics data display to provide easy access to users. While developing these capabilities, several problems had to be solved independently of the actual use of the MPP, all of which are outlined

Climatology of Haleakalā

The steep mountain slopes of Haleakalā Volcano (Maui, HI) support some of the most spatially diverse environments on the planet. Microclimates found across vertical gradients on the mountain slopes can change over relatively short differences in slope exposure and elevation and are strongly influenced by a persistent temperature inversion and northeast trade winds that are characteristic of this region. Eleven climate stations, which comprise the HaleNet climate network, have been monitoring climatic conditions along a 2030-m leeward (960 to 2990 m) and a 810-m windward (1650 to 2460 m) elevational transect, beginning as early as June of 1988. Hourly measurements of solar radiation, net radiation, relative humidity, wind speed, temperature, precipitation and soil moisture, and derived variables including potential evapotranspiration, vapor pressure deficit, soil heat flux, and daytime cloud attenuation of sunlight are analyzed in this study. This report documents the annual, diurnal and elevational characteri tics of these climatic variables as well as their behavior over the period-of-record (~1988 to 2013) in both the 6-month dry (May – October) and wet (November to April) seasons. Results show that the climate gradients along both leeward and windward elevation transects are highly influenced by the trade wind inversion in both dry and wet seasons. Period-of-record trends in the dry-season, show increases in energy and decrease in moisture at high elevations (>2000 m). Significant dry season changes include: decreases in precipitation (5 to 8% decade-1), relative humidity (3 to 5% decade-1) and cloud attenuation of sunlight (-2 to -5% decade-1) and increase in solar radiation (2 to 4% decade-1), vapor pressure deficit (9 to 10 % decade-1), zero precipitation days (4 to 5% decade-1) and potential evapotranspiration (3 to 7% decade -1). For the wet season, an opposite signal of change was observed at high elevation although trends were not as robust as the dry season trends. Reported dry season trends are potenti lly explained by a 4% significant increase in TWI frequency identified over a similar observation period (1991-2013). In addition to a climate variable analysis, this report also highlights other past and ongoing research projects that have taken place on the mountain and provides a summary of the history of the HaleNet climate network, the people and organizations that have contributed to its operation, and a list of publications that have made use of HaleNet climate data. It is the authors’ hope that this information will aid resource managers in protecting the ecosystems and other natural resources, and provide insight into ongoing and future climate changes on Haleakalā.The data analysis presented here and the preparation of this report were supported by the acific Island Climate Science Center (PICSC) and the Pacific Island Climate Change Cooperative (PICCC) and the Pacific Island Ecosystem Research Center (PIERC). We also thank Paul Krushelnycky, Shelley Crausbay, Abby Frazier, Henry Diaz, Erica von Allmen, Thomas Schroeder and Ross Sutherland for their contributions to this report. In conducting fieldwork on Maui, the authors were given support, encouragement, and assistance by numerous ndividuals. We extend our gratitude especially to Jotoku and Doris Asato, Dennis Nullet, Bill Minyard, Ryan Mudd, Dave Penn, Ron Nagata, Ted Rodrigues, Timmy Bailey, Matt Brown, Pamela Waiolena, Chuck Chimera, Kathy Wakely, Philip Thomas, and Sabine Jessel. We thank Haleakalā National Park and PIERC, and the USGS, for their long support of the HaleNet system. We owe a special debt of gratitude to Gordon Tribble of PIERC for his unwavering commitment to sustaining HaleNet. We would also like to thank Jeff Burgett of PICCC, Deborah Solis of the U.S. Army Corps of Engineers and Neil Fujii and Jeremy Kimura of the Commission on Water Resource Management. Over the years, HaleNet research has also been supported with funding from the University of Hawai‘i Research Council, the Water Resources Institute Program of the U.S. Geological Survey, the Cooperative National Parks Resources Study Unit, NSF EPSCoR (under award 0903833), and PICCC

Thermal reaction norms and the scale of temperature variation: latitudinal vulnerability of intertidal Nacellid limpets to climate change

The thermal reaction norms of 4 closely related intertidal Nacellid limpets, Antarctic (Nacella concinna), New Zealand (Cellana ornata), Australia (C. tramoserica) and Singapore (C. radiata), were compared across environments with different temperature magnitude, variability and predictability, to test their relative vulnerability to different scales of climate warming. Lethal limits were measured alongside a newly developed metric of “duration tenacity”, which was tested at different temperatures to calculate the thermal reaction norm of limpet adductor muscle fatigue. Except in C. tramoserica which had a wide optimum range with two break points, duration tenacity did not follow a typical aerobic capacity curve but was best described by a single break point at an optimum temperature. Thermal reaction norms were shifted to warmer temperatures in warmer environments; the optimum temperature for tenacity (Topt) increased from 1.0°C (N. concinna) to 14.3°C (C. ornata) to 18.0°C (an average for the optimum range of C. tramoserica) to 27.6°C (C. radiata). The temperature limits for duration tenacity of the 4 species were most consistently correlated with both maximum sea surface temperature and summer maximum in situ habitat logger temperature. Tropical C. radiata, which lives in the least variable and most predictable environment, generally had the lowest warming tolerance and thermal safety margin (WT and TSM; respectively the thermal buffer of CTmax and Topt over habitat temperature). However, the two temperate species, C. ornata and C. tramoserica, which live in a variable and seasonally unpredictable microhabitat, had the lowest TSM relative to in situ logger temperature. N. concinna which lives in the most variable, but seasonally predictable microhabitat, generally had the highest TSMs. Intertidal animals live at the highly variable interface between terrestrial and marine biomes and even small changes in the magnitude and predictability of their environment could markedly influence their future distributions

A KRAS-directed transcriptional silencing pathway that mediates the CpG island methylator phenotype

Approximately 70% of KRAS-positive colorectal cancers (CRCs) have a CpG island methylator phenotype (CIMP) characterized by aberrant DNA hypermethylation and transcriptional silencing of many genes. The factors involved in, and the mechanistic basis of, CIMP is not understood. Among the CIMP genes are the tumor suppressors p14(ARF), p15(INK4B), and p16(INK4A), encoded by the INK4-ARF locus. In this study, we perform an RNA interference screen and identify ZNF304, a zinc-finger DNA-binding protein, as the pivotal factor required for INK4-ARF silencing and CIMP in CRCs containing activated KRAS. In KRAS-positive human CRC cell lines and tumors, ZNF304 is bound at the promoters of INK4-ARF and other CIMP genes. Promoter-bound ZNF304 recruits a corepressor complex that includes the DNA methyltransferase DNMT1, resulting in DNA hypermethylation and transcriptional silencing. KRAS promotes silencing through upregulation of ZNF304, which drives DNA binding. Finally, we show that ZNF304 also directs transcriptional silencing of INK4-ARF in human embryonic stem cells. DOI: http://dx.doi.org/10.7554/eLife.02313.001

Quantum-Hall plateau-plateau transition in top-gated epitaxial graphene grown on SiC (0001)

We investigate the low-temperature magneto-transport properties of monolayer epitaxial graphene films formed on the Si-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. A high-k top-gate on the epitaxial graphene is realized by inserting a fully oxidized nanometer thin aluminum film as a seeding layer, followed by an atomic layer deposition process. At low temperatures, the devices demonstrate a strong field effect by the top gate with an on/off ratio of ~7 and an electron mobility up to ~3250 cm^2/Vs. After the observation of the half-integer quantum Hall effect for monolayer epitaxial graphene films, detailed magneto-transport measurements have been carried out including varying densities, temperatures, magnetic fields and currents. We study the width of the distinguishable quantum-Hall plateau to plateau transition (Landau level index n=0 to n=1) as temperature (T) and current are varied. For both gate voltage and magnetic field sweeps and T>10 K the transition width goes as T^{-\kappa} with exponent \kappa ~0.42. This universal scaling exponent agrees well with those found in III-V heterojunctions with short range alloy disorders and in exfoliated graphene.Comment: accepted by Journal of Applied Physic

Antisense Suppression of the Small Chloroplast Protein CP12 in Tobacco Alters Carbon Partitioning and Severely Restricts Growth

Abstract The thioredoxin-regulated chloroplast protein CP12 forms a multienzyme complex with the Calvin-Benson cycle enzymes phosphoribulokinase (PRK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). PRK and GAPDH are inactivated when present in this complex, a process shown in vitro to be dependent upon oxidized CP12. The importance of CP12 in vivo in higher plants, however, has not been investigated. Here, antisense suppression of CP12 in tobacco (Nicotiana tabacum) was observed to impact on NAD-induced PRK and GAPDH complex formation but had little effect on enzyme activity. Additionally, only minor changes in photosynthetic carbon fixation were observed. Despite this, antisense plants displayed changes in growth rates and morphology, including dwarfism and reduced apical dominance. The hypothesis that CP12 is essential to separate oxidative pentose phosphate pathway activity from Calvin-Benson cycle activity, as proposed in cyanobacteria, was tested. No evidence was found to support this role in tobacco. Evidence was seen, however, for a restriction to malate valve capacity, with decreases in NADP-malate dehydrogenase activity (but not protein levels) and pyridine nucleotide content. Antisense repression of CP12 also led to significant changes in carbon partitioning, with increased carbon allocation to the cell wall and the organic acids malate and fumarate and decreased allocation to starch and soluble carbohydrates. Severe decreases were also seen in 2-oxoglutarate content, a key indicator of cellular carbon sufficiency. The data presented here indicate that in tobacco, CP12 has a role in redox-mediated regulation of carbon partitioning from the chloroplast and provides strong in vivo evidence that CP12 is required for normal growth and development in plants.</jats:p

TEDI: the TripleSpec Exoplanet Discovery Instrument

The TEDI (TripleSpec - Exoplanet Discovery Instrument) will be the first instrument fielded specifically for finding low-mass stellar companions. The instrument is a near infra-red interferometric spectrometer used as a radial velocimeter. TEDI joins Externally Dispersed Interferometery (EDI) with an efficient, medium-resolution, near IR (0.9 - 2.4 micron) echelle spectrometer, TripleSpec, at the Palomar 200" telescope. We describe the instrument and its radial velocimetry demonstration program to observe cool stars.Comment: 6 Pages, To Appear in SPIE Volume 6693, Techniques and Instrumentation for Detection of Exoplanets II

A luminosity distribution for kilonovae based on short gamma-ray burst afterglows

The combined detection of a gravitational-wave signal, kilonova, and short gamma-ray burst (sGRB) from GW170817 marked a scientific breakthrough in the field of multi-messenger astronomy. But even before GW170817, there have been a number of sGRBs with possible associated kilonova detections. In this work, we re-examine these "historical" sGRB afterglows with a combination of state-of-the-art afterglow and kilonova models. This allows us to include optical/near-infrared synchrotron emission produced by the sGRB as well as ultraviolet/optical/near-infrared emission powered by the radioactive decay of $r$-process elements (i.e., the kilonova). Fitting the lightcurves, we derive the velocity and the mass distribution as well as the composition of the ejected material. The posteriors on kilonova parameters obtained from the fit were turned into distributions for the peak magnitude of the kilonova emission in different bands and the time at which this peak occurs. From the sGRB with an associated kilonova, we found that the peak magnitude in H bands falls in the range [-16.2, -13.1] ($95\%$ of confidence) and occurs within $0.8-3.6\,\rm days$ after the sGRB prompt emission. In g band instead we obtain a peak magnitude in range [-16.8, -12.3] occurring within the first $18\,\rm hr$ after the sGRB prompt. From the luminosity distributions of GW170817/AT2017gfo, kilonova candidates GRB130603B, GRB050709 and GRB060614 (with the possible inclusion of GRB150101B) and the upper limits from all the other sGRBs not associated with any kilonova detection we obtain for the first time a kilonova luminosity function in different bands.Comment: Published in MNRAS, 24 pages, 14 figure