282 research outputs found
Rooftop and ground standard temperatures: a comparison of physical differences
July 2000.Includes bibliographical references (pages 48-49).Accuracy and continuity of surface air temperature measurements are critical for many meteorological activities including short-term weather forecasting, warnings, and climate monitoring. In the United States and worldwide, most air temperature observations have historically been taken at a height of approximately 1.25 to 1.5 meters above the ground over a grass surface. In the last two decades, there has been a rapid expansion of nonfederal weather station networks to support state, regional and community needs. Many of these new weather stations are located on rooftops for reasons of security or convenience. Mixing these rooftop observations indiscriminately with observations from standard screen-height can pose significant issues for weather forecasting and verification, weather and climate analysis and climate applications such as energy demand planning and forecasting by large public utilities. This study establishes the physical mechanisms which cause a rooftop sensor to have a temperature bias relative to a nearby ground sensor. From a surface energy balance perspective, the physical characteristics of a surface are analyzed and related to temperature bias. This study identifies the surfaces and conditions leading to rooftop temperature bias in both maximum and minimum temperatures. These concepts are verified through both surface radiating temperature measurements and air temperature measurements contrasting roof and ground temperatures. Guidelines are then proposed to establish which roofs are unsuitable for temperature measurements and under what conditions a rooftop is vulnerable to temperature bias. Results indicate that overcast skies lead to small rooftop to ground differences in both surface radiating temperature and air temperature. Observations show differences of approximately 1 degree C or less in radiating temperature and less than 1 degree C in air temperature. An exception was observed where a wall effect led to more than a 2 degree C difference in air temperatures between roof and ground. Clear or partly cloudy skies allow larger rooftop temperature biases to develop. Roof to ground differences in surface radiating temperatures of up to 30 degrees C were observed. Although air temperature measurements were not made at all locations, observations show roof to ground differences of 3 degrees C for radiating temperature differences of 14 degrees C. The potential for even greater roof-ground air temperature differences exists at sites where radiating temperatures are further apart.Supported by the NOAA, National Weather Service, Office of Meteorology under grant NA67RJ0 152 Amend 21
TRF1 and TRF2 Differentially Modulate Rad51-Mediated Telomeric and Nontelomeric Displacement Loop Formation in Vitro
A growing body of literature suggests that the homologous recombination/repair (HR) pathway cooperates with components of the shelterin complex to promote both telomere maintenance and nontelomeric HR. This may be due to the ability of both HR and shelterin proteins to promote strand invasion, wherein a single-stranded DNA (ssDNA) substrate base pairs with a homologous double-stranded DNA (dsDNA) template displacing a loop of ssDNA (D-loop). Rad51 recombinase catalyzes D-loop formation during HR, and telomere repeat binding factor 2 (TRF2) catalyzes the formation of a telomeric D-loop that stabilizes a looped structure in telomeric DNA (t-loop) that may facilitate telomere protection. We have characterized this functional interaction in vitro using a fluorescent D-loop assay measuring the incorporation of Cy3-labeled 90-nucleotide telomeric and nontelomeric substrates into telomeric and nontelomeric plasmid templates. We report that preincubation of a telomeric template with TRF2 inhibits the ability of Rad51 to promote telomeric D-loop formation upon preincubation with a telomeric substrate. This suggests Rad51 does not facilitate t-loop formation and suggests a mechanism whereby TRF2 can inhibit HR at telomeres. We also report a TRF2 mutant lacking the dsDNA binding domain promotes Rad51-mediated nontelomeric D-loop formation, possibly explaining how TRF2 promotes nontelomeric HR. Finally, we report telomere repeat binding factor 1 (TRF1) promotes Rad51-mediated telomeric D-loop formation, which may facilitate HR-mediated replication fork restart and explain why TRF1 is required for efficient telomere replication
Self-rated health in rural Appalachia: health perceptions are incongruent with health status and health behaviors
<p>Abstract</p> <p>Background</p> <p>Appalachia is characterized by poor health behaviors, poor health status, and health disparities. Recent interventions have not demonstrated much success in improving health status or reducing health disparities in the Appalachian region. Since one's perception of personal health precedes his or her health behaviors, the purpose of this project was to evaluate the self-rated health of Appalachian adults in relation to objective health status and current health behaviors.</p> <p>Methods</p> <p>Appalachian adults (n = 1,576) were surveyed regarding health behaviors - soda consumer (drink ≥ 355 ml/d), or non-consumer (drink < 355 ml/d), fast food consumer (eating fast food ≥ 3 times/wk) or healthy food consumer (eating fast food < 3 times/wk), smoking (smoker or non-smoker), exercise (exerciser > 30 min > 1 d/wk) and sedentary (exercise < 30 min 1 d/wk), blood pressure medication (yes, no), and self-rated health. Blood pressure was measured through auscultation and serum cholesterol measured via needle prick. Weight status was based on BMI: normal weight (NW ≥ 18.5 and < 25.0), overweight (OW ≥ 25.0 and < 30.0), and obese (OB ≥ 30.0). Jaccard Binary Similarity coefficients, odds ratios, chi-square, and prevalence ratios were calculated to evaluate the relationships among self-rated health, objective health status, and health behaviors. Significance was set at p < 0.05.</p> <p>Results</p> <p>Respondents reported being healthy, while being sedentary (65%), hypertensive (76%), overweight (73%), or hyperlipidemic (79%). Between 57% and 66% of the respondents who considered themselves healthy had at least two disease conditions or poor health behaviors. Jaccard Binary Similarity coefficients and odds ratios showed the probability of reporting being healthy when having a disease condition or poor health behavior was high.</p> <p>Conclusions</p> <p>The association between self-rated health and poor health indicators in Appalachian adults is distorted. The public health challenge is to formulate messages and programs about health and health needs which take into account the current distortion about health in Appalachia and the cultural context in which this distortion was shaped.</p
Rif2 Promotes a Telomere Fold-Back Structure through Rpd3L Recruitment in Budding Yeast
Using a genome-wide screening approach, we have established the genetic requirements for proper telomere structure in
Saccharomyces cerevisiae. We uncovered 112 genes, many of which have not previously been implicated in telomere
function, that are required to form a fold-back structure at chromosome ends. Among other biological processes, lysine
deacetylation, through the Rpd3L, Rpd3S, and Hda1 complexes, emerged as being a critical regulator of telomere structure.
The telomeric-bound protein, Rif2, was also found to promote a telomere fold-back through the recruitment of Rpd3L to
telomeres. In the absence of Rpd3 function, telomeres have an increased susceptibility to nucleolytic degradation, telomere
loss, and the initiation of premature senescence, suggesting that an Rpd3-mediated structure may have protective
functions. Together these data reveal that multiple genetic pathways may directly or indirectly impinge on telomere
structure, thus broadening the potential targets available to manipulate telomere function
X-ray Evaluation of the Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS) Nickel-Replicated Mirrors
X-ray observations of astronomical objects provides diagnostics not available in any other wavelength regime, however the capability of making these observation at a high spatial resolution has proven challenging. Recently, NASA Marshall Space Flight Center (MSFC) has made good progress in employing computer numerical control (CNC) polishing techniques on electroless nickel mandrels as part of our replicated grazing incidence optics program. CNC polishing has afforded the ability to deterministically refine mandrel figure, thereby improving mirror performance. The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a MSFC-led sounding rocket instrument that is designed to make the first ever soft x-ray spectral observations of the Sun spatially resolved along a narrow slit. MaGIXS incorporates some of the first mirrors produced at MSFC using this polishing technique. Here we present the predicted mirror performance obtained from metrology, after completion of CNC polishing, as well as the results of X-ray tests performed on the MaGIXS telescope mirror before and after mounting
Distinguishing Tuberculosis from Nontuberculous Mycobacteria Lung Disease, Oregon, USA
To determine whether tuberculosis (TB) and nontuberculous mycobacteria (NTM) infection patients could be distinguished from one another with limited information, we compared pulmonary TB and NTM patients during 2005–2006. Our finding that age, birthplace, and presence of chronic obstructive pulmonary disease could differentiate TB and NTM disease could assist tuberculosis control efforts
SciClone: Inferring clonal architecture and tracking the spatial and temporal patterns of tumor evolution
The sensitivity of massively-parallel sequencing has confirmed that most cancers are oligoclonal, with subpopulations of neoplastic cells harboring distinct mutations. A fine resolution view of this clonal architecture provides insight into tumor heterogeneity, evolution, and treatment response, all of which may have clinical implications. Single tumor analysis already contributes to understanding these phenomena. However, cryptic subclones are frequently revealed by additional patient samples (e.g., collected at relapse or following treatment), indicating that accurately characterizing a tumor requires analyzing multiple samples from the same patient. To address this need, we present SciClone, a computational method that identifies the number and genetic composition of subclones by analyzing the variant allele frequencies of somatic mutations. We use it to detect subclones in acute myeloid leukemia and breast cancer samples that, though present at disease onset, are not evident from a single primary tumor sample. By doing so, we can track tumor evolution and identify the spatial origins of cells resisting therapy
Identification of PADI2 as a potential breast cancer biomarker and therapeutic target.
BACKGROUND: We have recently reported that the expression of peptidylarginine deiminase 2 (PADI2) is regulated by EGF in mammary cancer cells and appears to play a role in the proliferation of normal mammary epithelium; however, the role of PADI2 in the pathogenesis of human breast cancer has yet to be investigated. Thus, the goals of this study were to examine whether PADI2 plays a role in mammary tumor progression, and whether the inhibition of PADI activity has anti-tumor effects.
METHODS: RNA-seq data from a collection of 57 breast cancer cell lines was queried for PADI2 levels, and correlations with known subtype and HER2/ERBB2 status were evaluated. To examine PADI2 expression levels during breast cancer progression, the cell lines from the MCF10AT model were used. The efficacy of the PADI inhibitor, Cl-amidine, was tested in vitro using MCF10DCIS cells grown in 2D-monolayers and 3D-spheroids, and in vivo using MCF10DCIS tumor xenografts. Treated MCF10DCIS cells were examined by flow-cytometry to determine the extent of apoptosis and by RT2 Profiler PCR Cell Cycle Array to detect alterations in cell cycle associated genes.
RESULTS: We show by RNA-seq that PADI2 mRNA expression is highly correlated with HER2/ERBB2 (p = 2.2 x 106) in luminal breast cancer cell lines. Using the MCF10AT model of breast cancer progression, we then demonstrate that PADI2 expression increases during the transition of normal mammary epithelium to fully malignant breast carcinomas, with a strong peak of PADI2 expression and activity being observed in the MCF10DCIS cell line, which models human comedo-DCIS lesions. Next, we show that a PADI inhibitor, Cl-amidine, strongly suppresses the growth of MCF10DCIS monolayers and tumor spheroids in culture. We then carried out preclinical studies in nude (nu/nu) mice and found that Cl-amidine also suppressed the growth of xenografted MCF10DCIS tumors by more than 3-fold. Lastly, we performed cell cycle array analysis of Cl-amidine treated and control MCF10DCIS cells, and found that the PADI inhibitor strongly affects the expression of several cell cycle genes implicated in tumor progression, including p21, GADD45alpha, and Ki67.
CONCLUSION: Together, these results suggest that PADI2 may function as an important new biomarker for HER2/ERBB2+ tumors and that Cl-amidine represents a new candidate for breast cancer therapy
Berkeley Supernova Ia Program I: Observations, Data Reduction, and Spectroscopic Sample of 582 Low-Redshift Type Ia Supernovae
In this first paper in a series we present 1298 low-redshift (z\leq0.2)
optical spectra of 582 Type Ia supernovae (SNe Ia) observed from 1989 through
2008 as part of the Berkeley SN Ia Program (BSNIP). 584 spectra of 199 SNe Ia
have well-calibrated light curves with measured distance moduli, and many of
the spectra have been corrected for host-galaxy contamination. Most of the data
were obtained using the Kast double spectrograph mounted on the Shane 3 m
telescope at Lick Observatory and have a typical wavelength range of
3300-10,400 Ang., roughly twice as wide as spectra from most previously
published datasets. We present our observing and reduction procedures, and we
describe the resulting SN Database (SNDB), which will be an online, public,
searchable database containing all of our fully reduced spectra and companion
photometry. In addition, we discuss our spectral classification scheme (using
the SuperNova IDentification code, SNID; Blondin & Tonry 2007), utilising our
newly constructed set of SNID spectral templates. These templates allow us to
accurately classify our entire dataset, and by doing so we are able to
reclassify a handful of objects as bona fide SNe Ia and a few other objects as
members of some of the peculiar SN Ia subtypes. In fact, our dataset includes
spectra of nearly 90 spectroscopically peculiar SNe Ia. We also present
spectroscopic host-galaxy redshifts of some SNe Ia where these values were
previously unknown. [Abridged]Comment: 34 pages, 11 figures, 11 tables, revised version, re-submitted to
MNRAS. Spectra will be released in January 2013. The SN Database homepage
(http://hercules.berkeley.edu/database/index_public.html) contains the full
tables, plots of all spectra, and our new SNID template
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