Direct measurement of carbon-14 in carbon dioxide by liquid scintillation counting

Liquid scintillation counting technique is applied to the direct measurement of carbon-14 in carbon dioxide. This method has high counting efficiency and eliminates many of the basic problems encountered with previous techniques. The technique can be used to achieve a percent substitution reaction and is of interest as an analytical technique

Recent development in organic scintillators

Discussion on recent developments of organic scintillators includes studies of organic compounds that form glass-like masses which scintillate and are stable at room temperature, correlations between molecular structure of organic scintillators and self-quenching, recently developed fast scintillators, and applications of liquid-scintillation counters

Lipid peroxidation is essential for α-synuclein-induced cell death.

Parkinson's disease is the second most common neurodegenerative disease and its pathogenesis is closely associated with oxidative stress. Deposition of aggregated α-synuclein (α-Syn) occurs in familial and sporadic forms of Parkinson's disease. Here, we studied the effect of oligomeric α-Syn on one of the major markers of oxidative stress, lipid peroxidation, in primary co-cultures of neurons and astrocytes. We found that oligomeric but not monomeric α-Syn significantly increases the rate of production of reactive oxygen species, subsequently inducing lipid peroxidation in both neurons and astrocytes. Pre-incubation of cells with isotope-reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of oligomeric α-Syn on lipid peroxidation. Inhibition of lipid peroxidation with D-PUFAs further protected cells from cell death induced by oligomeric α-Syn. Thus, lipid peroxidation induced by misfolding of α-Syn may play an important role in the cellular mechanism of neuronal cell loss in Parkinson's disease. We have found that aggregated α-synuclein-induced production of reactive oxygen species (ROS) that subsequently stimulates lipid peroxidation and cell death in neurons and astrocytes. Specific inhibition of lipid peroxidation by incubation with reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of α-synuclein on lipid peroxidation and cell death

Low Rank Vector Bundles on the Grassmannian G(1,4)

Here we define the concept of $L$-regularity for coherent sheaves on the Grassmannian G(1,4) as a generalization of Castelnuovo-Mumford regularity on ${\bf{P}^n}$. In this setting we prove analogs of some classical properties. We use our notion of $L$-regularity in order to prove a splitting criterion for rank 2 vector bundles with only a finite number of vanishing conditions. In the second part we give the classification of rank 2 and rank 3 vector bundles without "inner" cohomology (i.e. H^i_*(E)=H^i(E\otimes\Q)=0 for any $i=2,3,4$) on G(1,4) by studying the associated monads.Comment: 11 pages, no figure

Missouri grain sorghum performance trials, 1969

"MP 138, February, 1970""This bulletin reports on Department of Agronomy research project 351, Sorghum Testing. The statistics pertaining to sorghum production were furnished by R.S. Overton of the U.S. Department of Agriculture, Agricultural Marketing Service, Columbia, Missouri. Climatological data were furnished by W.L. Decker, Professor and Chairman, Department of Atmospheric Science, University of Missouri. The following individuals assisted in making the 1969 Grain Sorghum Trials possible: Larkin Langford, Louis Meinke, Earl Page, Dr. Norman Justus, Norman Brown, and N.G. Weir."--Page 2."Locations. Grain sorghum performance trials were conducted at four locations in 1969, Fig. 1. They were located at the North Missouri Center near Spickard in Grundy County, on the Earl Page farm near Palmyra in Marion County, on the N. G. Weir farm near Columbia in Boone County, and at the Southwest Center near Mt. Vernon in Lawrence County. A fifth location was planted at the Delta Center near Portageville in Pemiscot County but was not harvested due to hail and bird damage. The test site at the Southwest Center was located on a Gerald soil. This soil is characterized by very slow permeability to water and air, nearly level topography, moderate water storage capacity, a claypan subsoil, medium inherent fertility, and a tendency to be slighty doughty during summer months. These characteristics coupled with a May 1 to September 15 rainfall deficit of 6 to 8 inches resulted in greatly reduced yields (Table 9). The variation, due to soil, at this site was accentuated by the drought. Thus relatively large difference in yield among entries were required for statistical significance. State production. In 1968, 216,000 acres of grain sorghum were harvested in Missouri with an average yield of 66 bushels per acre. The 1969 estimate of harvested grain sorghum is 214,000 acres and 91. 1 percent of the 1960-1969 average. The state-wide 1969 estimate of 64 bushels per acre is 9. 7 bushels more than the 10-year average and six bushels less than the 1969 estimated corn yield. These data are summarized in Table 1. Sorghum vs corn. Comparisons between the yield of corn and grain sorghum at three of the testing sites can be made since these tests were located either in the same field or close proximity (Table 2). These comparisons are only suggestive; planting and cultural factors were not the same for corn and sorghum. Interpretation of differences in yield. Small yield differences should not be overemphasized since there was considerable inherent variation in the soil at each test site. Special planting arrangements and use of the statistical procedure called analysis of variance, from which the L. S. D. (least significant difference) value is computed, help make valid yield comparisons. The L. S. D. value, found at the bottom of the tables, simply states how much one hybrid must differ from another in yield to be reasonably confident of superior performance."--Introduction.R.D. Horrocks, F.D. Cloninge

Algorithm for Adapting Cases Represented in a Tractable Description Logic

Case-based reasoning (CBR) based on description logics (DLs) has gained a lot of attention lately. Adaptation is a basic task in the CBR inference that can be modeled as the knowledge base revision problem and solved in propositional logic. However, in DLs, it is still a challenge problem since existing revision operators only work well for strictly restricted DLs of the \emph{DL-Lite} family, and it is difficult to design a revision algorithm which is syntax-independent and fine-grained. In this paper, we present a new method for adaptation based on the DL $\mathcal{EL_{\bot}}$. Following the idea of adaptation as revision, we firstly extend the logical basis for describing cases from propositional logic to the DL $\mathcal{EL_{\bot}}$, and present a formalism for adaptation based on $\mathcal{EL_{\bot}}$. Then we present an adaptation algorithm for this formalism and demonstrate that our algorithm is syntax-independent and fine-grained. Our work provides a logical basis for adaptation in CBR systems where cases and domain knowledge are described by the tractable DL $\mathcal{EL_{\bot}}$.Comment: 21 pages. ICCBR 201

Triaging informative cis-regulatory elements for the combinatorial control of temporal gene expression during Plasmodium falciparum intraerythrocytic development

Background: Over 2700 genes are subject to stage-specific regulation during the intraerythrocytic development of the human malaria parasite Plasmodium falciparum. Bioinformatic analyses have identified a large number of over-represented motifs in the 5′ flanking regions of these genes that may act as cis-acting factors in the promoter-based control of temporal expression. Triaging these lists to provide candidates most likely to play a role in regulating temporal expression is challenging, but important if we are to effectively design in vitro studies to validate this role. Methods: We report here the application of a repeated search of variations of 5′ flanking sequences from P. falciparum using the Finding Informative Regulatory Elements (FIRE) algorithm. Results: Our approach repeatedly found a short-list of high scoring DNA motifs, for which cognate specific transcription factors were available, that appear to be typically associated with upregulation of mRNA accumulation during the first half of intraerythrocytic development. Conclusions: We propose these cis-trans interactions may provide a combinatorial promoter-based control of gene expression to complement more global mechanisms of gene regulation that can account for temporal control during the second half of intraerythrocytic development

An analysis of multispectral unmanned aerial systems for saltmarsh foreshore land cover classification and digital elevation model generation

1 online resource (viii, 84 p.) : illustrations (chiefly colored)Includes abstract in English and French.Includes appendix.Includes bibliographical references (p. 60-66).Recent advances in Unmanned Aerial Systems (UAS), and increased affordability, have proliferated their use in the scientific community. Despite these innovations, UAS attempts to map a site’s true elevation using Structure from Motion Multi-View Stereo (SFM-MVS) software are obstructed by vegetative canopies, resulting in the production of a Digital Surface Model (DSM), rather than the desired Digital Elevation Model (DEM). This project seeks to account for the varying heights of vegetation communities within the Masstown East saltmarsh, producing DEMs for mudflat/saltmarsh landscapes with an accuracy comparable to that the DSM. DEM generation has been completed in two separate stages. The first stage consists of land cover classifications using UAS derived, radiometrically corrected data. Respective land cover classifications are assessed using confusion matrices. Secondly, surveyed canopy heights and function derived heights are subtracted from their respective classes, generating the DEMs. DEM validation has been performed by comparing topographic survey point values to those modeled, using the Root Square Mean Error (RMSE) measure. The project then compares the various parameters implemented for land cover classifications, and DEM accuracy. DEM generation methods were then coupled to produce a final DEM with a RMSE of 6cm. The results suggest consumer grade Multispectral UAS can produce DEMs with accuracies comparable to the initial DSMs generated, and thus merit further studies investigating their scientific capacities