7,356 research outputs found
C.C. Slaughter's Lazy S Ranch in Cochran and Hockley counties, 1898-1921.
Full text linkLikely added to or created for the author's thesis: "A Cattle Kingdom on Texas' Last Frontier: C. C. Slaughter's Lazy S Ranch" (Texas Tech University, 1970).Scale approximately 1:337,920 (W 102°59'24"--W 102°18'53"/N 33°50'54"--N 33°24'07")The map illustrates the 250,000-acre holdings of C.C. Slaughter, known as the "Cattle King of Texas," before the ranch's liquidation and subdivision beginning in 1921 (following his death in 1919)
Protein Free Energy Landscapes Remodeled by Ligand Binding
No full textAbstractGlucose/galactose binding protein (GGBP) functions in two different larger systems of proteins used by enteric bacteria for molecular recognition and signaling. Here we report on the thermodynamics of conformational equilibrium distributions of GGBP. Three fluorescence components appear at zero glucose concentration and systematically transition to three components at high glucose concentration. Fluorescence anisotropy correlations, fluorescent lifetimes, thermodynamics, computational structure minimization, and literature work were used to assign the three components as open, closed, and twisted conformations of the protein. The existence of three states at all glucose concentrations indicates that the protein continuously fluctuates about its conformational state space via thermally driven state transitions; glucose biases the populations by reorganizing the free energy profile. These results and their implications are discussed in terms of the two types of specific and nonspecific interactions GGBP has with cytoplasmic membrane proteins
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Full text linkThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Pinpointing sources of pollution using citizen science and hyperlocal low-cost mobile source apportionment
Full text linkCurrently, methodologies for the identification and apportionment of air pollution sources are not widely applied due to their high cost. We present a new approach, combining mobile measurements from multiple sensors collected from the daily walks of citizen scientists, in a high population density area of Birmingham, UK. The methodology successfully pinpoints the different sources affecting the local air quality in the area using only a handful of measurements. It was found that regional sources of pollution were mostly responsible for the PM2.5 and PM1 concentrations. In contrast, PM10 was mostly associated with local sources. The total particle number and the lung deposited surface area of PM were almost solely associated with traffic, while black carbon was associated with both the sources from the urban background and local traffic. Our analysis showed that while the effect of the hyperlocal sources, such as emissions from construction works or traffic, do not exceed the distance of a couple of hundred meters, they can influence the health of thousands of people in densely populated areas. Thus, using this novel approach we illustrate the limitations of the present measurement network paradigm and offer an alternative and versatile approach to understanding the hyperlocal factors that affect urban air quality. Mobile monitoring by citizen scientists is shown to have huge potential to enhance spatiotemporal resolution of air quality data without the need of extensive and expensive campaigns
Size distribution of airborne particles controls outcome of epidemiological studies
No full textEpidemiological studies typically using wide size range mass metrics (e.g. PM(10)) have demonstrated associations between airborne particulate matter and several adverse health outcomes. This approach ignores the fact that mass concentration may not correlate with regional lung dose, unlike the case of trace gases. When using measured particle size distributions as the basis for calculating regional lung dose, PM(10) mass concentration is found to be a good predictor of the mass dose in all regions of the lung, but is far less predictive of the surface area and particle number dose. On the other hand, measurements of particle number do not well predict mass dose, indicating that the chosen particle metric is likely to determine the health outcomes detectable by an epidemiological study. Consequently, epidemiological studies using mass metrics (PM(2.5) and PM(10)) may fail to recognise important health consequences of particulate matter exposure, leading to an underestimate of the public health consequences of particle exposure
Local and regional components of aerosol in a heavily trafficked street canyon in central London derived from PMF and cluster analysis of single-particle ATOFMS spectra
Full text link11 pages, supporting information http://pubs.acs.org/doi/suppl/10.1021/es506249zPositive matrix factorization (PMF) has been applied to single particle ATOFMS spectra collected on a six lane heavily trafficked road in central London (Marylebone Road), which well represents an urban street canyon. PMF analysis successfully extracted 11 factors from mass spectra of about 700 000 particles as a complement to information on particle types (from K-means cluster analysis). The factors were associated with specific sources and represent the contribution of different traffic related components (i.e., lubricating oils, fresh elemental carbon, organonitrogen and aromatic compounds), secondary aerosol locally produced (i.e., nitrate, oxidized organic aerosol and oxidized organonitrogen compounds), urban background together with regional transport (aged elemental carbon and ammonium) and fresh sea spray. An important result from this study is the evidence that rapid chemical processes occur in the street canyon with production of secondary particles from road traffic emissions. These locally generated particles, together with aging processes, dramatically affected aerosol composition producing internally mixed particles. These processes may become important with stagnant air conditions and in countries where gasoline vehicles are predominant and need to be considered when quantifying the impact of traffic emissions. © 2015 American Chemical SocietyPeer Reviewe
Variations in tropospheric submicron particle size distributions across the European continent 2008-2009
No full textBeddows, D. C. S. ... et. al.-- 22 pages, 11 figures, 1 table, supplementary material related to this article is available online at http://www.atmos-chem-phys.net/14/4327/2014/acp-14-4327-2014-supplement.pdfClusteranalysis of particle number size distributions frombackground sites across Europeis presented. This generated a total of nine clusters of particle size distributions which could be further combined into two main groups, namely: a south-to-north category (four clusters) and a west-to-east category (five clusters). The first group was identified as most frequently being detected inside and around northern Germany and neighbouring countries, showing clear evidence of local afternoon nucleation and growth events that could be linked to movement of air masses from south to north arriving ultimately at the Arctic contributing to Arctic haze.The second group of particle size spectra proved to have narrower size distributions and collectively showed a dependence of modal diameter upon the longitude of the site (west to east) at which they were most frequently detected.These clusters indicated regional nucleation (at the coastal sites) growing to larger modes further inland. The apparent growth rate of the modal diameter was around 0.6-0.9 nm h-1. Four specific air mass back-trajectories were successively taken as case studies to examine in real time the evolution of aerosol size distributions across Europe. While aerosol growth processes can be observed as aerosol traverses Europe, the processes are often obscured by the addition of aerosol by emissions en route. This study revealed that some of the 24 stations exhibit more complex behaviour than others, especially when impacted by local sources or a variety of different air masses. Overall, the aerosol size distribution clustering analysis greatly simplifies the complex data set and allows a description of aerosol aging processes, which reflects the longer-term average development of particle number size distributions as air masses advect across Europe. © 2014 Author(s)The National Centre for Atmospheric Science is funded by the UK Natural Environment Research Council. This work was also supported by the European Union EUCAARI (Contract Ref. 036833) and EUSAAR (Contract Ref. 026140) research projectsPeer Reviewe
Prompt charm production in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV
Full text linkCharm production at the LHC in pp collisions at s√=7 TeV is studied with the LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, D+s→ϕ(K−K+)π+, Λ+c→pK−π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0<pT<8 GeV/c and 2.0<y<4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above pT-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives
σ(cc¯)pT<8 GeV/c,2.0<y<4.5=1419±12(stat)±116(syst)±65(frag) μb,
where the uncertainties are statistical, systematic, and due to the fragmentation functions
Analýza souborového systému pomocí Verifying C Compiler
Full text linkNázev práce: Analýza souborového systému pomocí Verifying C Compiler Autor: Bc. David Škorvaga Katedra: Katedra distribuovaných a spolehlivých systémů Vedoucí diplomové práce: RNDr. Jan Kofroň, Ph.D. Abstrakt: Formální verifikace je jeden ze způsobů, jak zlepšit spolehlivost soft- warových systémů. Jeden z přístupů formální verifikace se zaměřuje na dokazo- vaní správnosti anotovaného zdrojového kódu v široce používaném programovacím jazyce. Verifier C Compiler (VCC) je verifikátor pro concurrent C, který přijímá anotovaný kód v jazyce C a automaticky ověřuje jeho správnost s ohledem na tuto anotaci. Už se objevily úspěšné pokusy o ověření některých kritických systémů, včetně jádra operačního systému. Další důležitou součástí operačního systému je jeho systém souborů. V diplomové práci jsme si vybrali souborový systém FatFs, odlehčenou implementaci souborového systému FAT, nezávislou na zařízení. V této práci vytvoříme specifikaci jeho části pomocí anotace VCC a úspěšně ověříme jeho korektnost. Klíčová slova: Formal Verification, File System, VCCTitle: Analysis of a File System Using the Verifying C Compiler Author: Bc. David Škorvaga Department: Department of Distributed and Dependable Systems Supervisor: RNDr. Jan Kofroň, Ph.D. Abstract: Formal verification is a way to improve reliability of software systems. One approach of formal verification is focused on proving correctness of annotat- ed source code of an established programming language. Verifying C Compiler (VCC) is a verifier for concurrent C that accepts an annotated code in C language and automatically verifies its correctness with respect to the given annotation. There have been successful attempts to verify some critical systems, including the operating system kernel. Another critical part of operating system is its file system. In the thesis, we choose FatFs file system, a simple device-independent implementation of the FAT file system. We specify a part of it using the VCC annotation and successfully verify its correctness. Keywords: Formal Verification, File System, VCCDepartment of Distributed and Dependable SystemsKatedra distribuovaných a spolehlivých systémůMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Dynamics and folding of single two-stranded coiled-coil peptides studied by fluorescent energy transfer confocal microscopy
No full textWe report single-molecule measurements on the folding and unfolding conformational equilibrium distributions and dynamics of a disulfide crosslinked version of the two-stranded coiled coil from GCN4. The peptide has a fluorescent donor and acceptor at the N termini of its two chains and a Cys disulfide near its C terminus. Thus, folding brings the two N termini of the two chains close together, resulting in an enhancement of fluorescent resonant energy transfer. End-to-end distance distributions have thus been characterized under conditions where the peptide is nearly fully folded (0 M urea), unfolded (7.4 M urea), and in dynamic exchange between folded and unfolded states (3.0 M urea). The distributions have been compared for the peptide freely diffusing in solution and deposited onto aminopropyl silanized glass. As the urea concentration is increased, the mean end-to-end distance shifts to longer distances both in free solution and on the modified surface. The widths of these distributions indicate that the molecules are undergoing millisecond conformational fluctuations. Under all three conditions, these fluctuations gave nonexponential correlations on 1- to 100-ms time scale. A component of the correlation decay that was sensitive to the concentration of urea corresponded to that measured by bulk relaxation kinetics. Thetrajectories provided effective intramolecular diffusion coefficients as a function of the end-to-end distances for the folded and unfolded states. Single-molecule folding studies provide information concerning the distributions of conformational states in the folded, unfolded, and dynamically interconverting states.Author manuscript. Published in final edited form as: Proc Natl Acad Sci U S A. 2000 November 21; 97(24): 13021-13026.The final published version of this article is located at: http://www.pnas.org/cgi/reprint/97/24/13021NIH GM54616; to William F. DeGradoNIH GM12592; to Robin M. HochstrasserNIH GM48130; to William F. Degrado and Robin M. HochstrasserThis work was supported by GM54616 (to W.F.D.), GM12592 (to R.M.H.) and GM48130 (to W.F.D. and R.M.H.) with instrumentation developed under RR01348. D.S.T. was supported by National Institutes of Health Grant NRSA F32-GM18589.Also available in PubMed Central. PMCID:PMC2717
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