Application of EREP imagery to fracture-related mine safety hazards in coal mining and mining-environmental problems in Indiana

The author has identified the following significant results. This investigation evaluated the applicability of a variety of sensor types, formats, and resolution capabilities to the study of both fuel and nonfuel mined lands. The image reinforcement provided by stereo viewing of the EREP images proved useful for identifying lineaments and for mined lands mapping. Skylab S190B color and color infrared transparencies were the most useful EREP imagery. New information on lineament and fracture patterns in the bedrock of Indiana and Illinois extracted from analysis of the Skylab imagery has contributed to furthering the geological understanding of this portion of the Illinois basin

Heterocyst placement strategies to maximize growth of cyanobacterial filaments

Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape while the average spacing between heterocysts continuously increases.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version will be available onlin

Primer registro de Anisodontherium (Mammalia, Xenarthra, Megatheriidae) en el Mioceno tardío del noroeste de Argentina

En Argentina, los Megatheriinae se registran desde el Colloncurense (Mioceno medio) hasta el Lujanense (Pleistoceno tardío-Holoceno). Para el Mioceno tardío-Plioceno del noroeste de Argentina están representados por Pyramiodontherium bergi (Moreno y Mercerat), P. brevirostrum Carlini, Brandoni, Scillato-Yané y Pujos y P. scillatoyanei De Iuliis, Ré y Vizcaíno. En la presente contribución se describe un ejemplar de megaterino hallado en sedimentos de la parte alta de la Formación Saladillo (unidad basal del Subgrupo Santa María), en el área de Cerro Castillo de Las Brujas, provincia de Tucumán. La unidad está integrada por areniscas finas, limolitas, areniscas medias y raramente areniscas gruesas y arcillitas. Próximo a los niveles portadores del material se observan clastos pumíceos de hasta 2cm de diámetro, que evidencian un aporte volcánico importante. Una datación efectuada en un nivel estratigráfica y geográficamente próximo indica una edad de 10 ± 0.3 Ma (Mioceno tardío). El ejemplar está representado por varios fragmentos de los cuales se destaca una mandíbula completa que se caracteriza por presentar: 1) los molariformes comprimidos anteroposteriormente y con un valle en V muy marcado, 2) el m4 anterior respecto del margen anterior del proceso coronoideo, siendo totalmente visible en vista lateral, 3) la abertura posterior del canal mandibular ubicada en la base del proceso coronoideo, 4) el margen posterior de la sínfisis mandibular por delante del m1. Dichas características se presentan en Anisodontherium halmyronomum (Cabrera) procedente de la Formación Arroyo Chasicó (Mioceno tardío), Buenos Aires. Por lo tanto, el ejemplar debiera referirse a Anisodontherium y, dado que presenta algunas diferencias respecto de A. halmyronomum, posiblemente represente una nueva especie de Megatheriinae. La presencia de Anisodontherium en el Mioceno tardío de Tucumán incrementa la distribución geográfica del género y amplía la diversidad de Megatheriinae en el noroeste de Argentina.Sesiones libresFacultad de Ciencias Naturales y Muse

Self-Organized Criticality model for Brain Plasticity

Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Here we present a model based on self-organized criticality and taking into account brain plasticity, which is able to reproduce the spectrum of electroencephalograms (EEG). The model consists in an electrical network with threshold firing and activity-dependent synapse strenghts. The system exhibits an avalanche activity power law distributed. The analysis of the power spectra of the electrical signal reproduces very robustly the power law behaviour with the exponent 0.8, experimentally measured in EEG spectra. The same value of the exponent is found on small-world lattices and for leaky neurons, indicating that universality holds for a wide class of brain models.Comment: 4 pages, 3 figure

The effects of individual nonheritable variation on fitness estimation and coexistence

Demographic theory and data have emphasized that non-heritable variation in individual frailty enables selection within cohorts, affecting the dynamics of a population while being invisible to its evolution. Here we include the component of individual variation in longevity or viability which is non-heritable in simple bacterial growth models and explore its ecological and evolutionary impacts. First, we find that this variation produces consistent trends in longevity differences between bacterial genotypes when measured across stress gradients. Given that direct measurements of longevity are inevitably biased due to the presence of this variation and ongoing selection, we propose the use of the trend itself for obtaining more exact inferences of genotypic fitness. Second, we show how species or strain coexistence can be enabled by non36 heritable variation in longevity or viability. These general conclusions are likely to extend beyond bacterial systems

UK Immunotherapy Study: reanalysis by a combined symptom and medication score

Reanalysis of UK22 subcutaneous immunotherapy trial according to WAO/EAACI recommendations revealed clinically relevant improvements at both doses. Starting at the lower dose should enable efficacy with lower risk of adverse events

RAPD PCR detects co-colonisation of multiple Group B Streptococcus genotypes: a practical molecular technique for screening multiple colonies

Group B Streptococcus (GBS) is a leading cause of neonatal meningitis, pneumonia, and sepsis. The biggest contributing factor of neonatal infections is due to vertical transmission from maternal colonisation of GBS in the genitourinary tract. Multiple serotype colonisation is often not investigated in epidemiological studies, but it is an important consideration for serotype-based vaccine development and implementation to ensure less abundant serotypes are not under-represented. In this study, we show that RAPD PCR is a quick tool useful in screening the presence of genetically different strains using multiple colony picks from a single patient swab. We observed a maximum of five different GBS strains colonising a single patient at a specific time

BAT AGN spectroscopic survey - XV: the high frequency radio cores of ultra-hard X-ray selected AGN

We have conducted 22 GHz radio imaging at 1 arcsec resolution of 100 low-redshift AGN selected at 14–195 keV by the Swift-BAT. We find a radio core detection fraction of 96 per cent, much higher than lower frequency radio surveys. Of the 96 radio-detected AGN, 55 have compact morphologies, 30 have morphologies consistent with nuclear star formation, and 11 have sub-kpc to kpc-scale jets. We find that the total radio power does not distinguish between nuclear star formation and jets as the origin of the radio emission. For 87 objects, we use optical spectroscopy to test whether AGN physical parameters are distinct between radio morphological types. We find that X-ray luminosities tend to be higher if the 22 GHz morphology is jet-like, but find no significant difference in other physical parameters. We find that the relationship between the X-ray and core radio luminosities is consistent with the L_R/L_X ∼ 10⁻⁵ of coronally active stars. We further find that the canonical fundamental planes of black hole activity systematically overpredict our radio luminosities, particularly for objects with star formation morphologies

Gadolinium-Enhanced Magnetic Susceptibility Contrast Is Reduced in the Corpus Callosum of a Mouse Model of Tauopathy

Alterations to white matter have been implicated in a number of neurodegenerative diseases. In this work we investigate the sensitivity of MRI magnetic susceptibility mapping to these changes using a mouse model of Tauopathy. A non-rigid registration of contrast enhanced, high resolution ex vivo mouse brain images is used to transform susceptibility maps into a common space and a voxel-wise group comparison is performed. Significant differences were observed that may indicate disruption to the tissue of the corpus callosum

Studies on the preparation, properties and analysis of high purity yttrium oxide and yttrium metal at the Ames Laboratory

The research and development work carried out at the Ames Laboratory on the chemistry and metallurgy of yttrium is described in detail in this report or companion reports to which references are herein made. Discussions of the separation of yttrium from the rare-earth elements by ion exchange, of comprehensive investigations of the preparation of yttrium fluoride, and of various ways of reducing the fluoride to the metallic state are presented. Chemical and spectrographic methods of analyzing yttrium and its compounds for oxygen and other impurities are described and comparisons made between the different methods. A pilot plant process for producing tonnage quantities of yttrium metal is presented with detailed descriptions of the equipment and operating procedures employed. The complete process entails the extraction of an yttrium and rare earth mixture from xenotime sand, separation of the yttrium from this mixture in thirty-inch-diameter columns, hydrofluorination of the resulting oxide and its subsequent reduction to the metal. The basic metal process consists of the reduction of yttrium fluoride with calcium, forming a low melting yttrium-magnesium alloy. The magnesium is subsequently removed by vacuum sublimation, producing a porous yttrium product. This is consolidated by vacuum arc melting into a six-inch-diameter ingot. Quantities of high purity yttrium metal were prepared by vacuum distillation and by-a sa,lt extraction refining process. Yttrium metal containing 100 to 300 ppm oxygen is soft, ductile and easily fabricated at room temperature