2,798 research outputs found
Variation in Restaurant Sanitary Scores in New York City
The purpose of this study was to determine whether restaurants that are homogenous in nature would exhibit substantially different hygiene scores based on the underlying consumer learning behaviors present in the neighborhoods in which the restaurants are located
Accuracy and Stability of Integration Methods for Neutrino Transport in Core Collapse Supernovae
Bioinformatics and Handwriting/Speech Reconition: Uncoventional Applications of Similarity Search Tools
This work introduces two unconventional applications for sequence alignment algorithms outside the domain of bioinformatics: handwriting recognition and speech recognition. In each application we treated data samples, such as the path of a and written pen stroke, as a protein sequence and use the FastA sequence alignment tool to classify unknown data samples, such as a written character. That is, we handle the handwriting and speech recognition problems like the protein annotation problem: given a sequence of unknown function, we annotate the sequence via sequence alignment. This approach achieves classification rates of 99.65% and 93.84% for the handwriting and speech recognition respectively. In addition, we provide a framework for applying sequence alignment to a variety of other non–traditional problems.Singapore-MIT Alliance (SMA
Characterizing hormesis and the in vitro effects of sub-lethal fungicide exposure in sclerotinia homoeocarpa
Dollar spot, caused by Sclerotinia homoeocarpa F.T. Bennett, is the most economically important disease of turfgrass. Dollar spot reduces aesthetics and playability of turfgrass, and when left uncontrolled can result in plant death and weed encroachment. Sterol demethylase inhibiting (DMI) fungicides are valuable for dollar spot control due to their broad spectrum of activity with single applications. Previous studies have shown sub-lethal concentrations of fungicides can cause plant pathogens to exhibit hormesis. The first goal of this research was to evaluate the effects of sub-lethal doses of DMI fungicides on the mycelial growth of a range of S. homoeocarpa isolates via an in vitro fungicide assay. The second goal was to examine the impact of sub-lethal doses of DMI fungicides on the production of oxalic acid in S. homoeocarpa. The third goal was to determine the effects of low doses of DMI fungicides on the disease severity of resistant and sensitive populations of S. homoeocarpa on creeping bentgrass. Sub-lethal concentrations of DMI fungicides did not cause significant increases of mycelial growth in vitro when compared to mycelial growth of untreated isolates. A method to detect oxalic acid via high performance liquid chromatography was developed in this research. Oxalic acid concentrations were greatest when isolates were treated with a high rate of DMI fungicides. In the greenhouse, area under the disease progress curve (AUDPC) was consistently increased by a sub-lethal rate of DMI fungicides when compared to untreated inoculum. A sublethal rate of DMI fungicides consistently caused increased mean disease severity as early as 21 days after treatment. Results of this study suggest sub-lethal concentrations of fungicides may induce hormesis in S. homoeocarpa, resulting in increased dollar spot pressure in creeping bentgrass.Includes bibliographical reference
Fragment Coupling and the Construction of Quaternary Carbons Using Tertiary Radicals Generated From tert-Alkyl N-Phthalimidoyl Oxalates By Visible-Light Photocatalysis.
The coupling of tertiary carbon radicals with alkene acceptors is an underdeveloped strategy for uniting complex carbon fragments and forming new quaternary carbons. The scope and limitations of a new approach for generating nucleophilic tertiary radicals from tertiary alcohols and utilizing these intermediates in fragment coupling reactions is described. In this method, the tertiary alcohol is first acylated to give the tert-alkyl N-phthalimidoyl oxalate, which in the presence of visible-light, catalytic Ru(bpy)3(PF6)2, and a reductant fragments to form the corresponding tertiary carbon radical. In addition to reductive coupling with alkenes, substitution reactions of tertiary radicals with allylic and vinylic halides is described. A mechanism for the generation of tertiary carbon radicals from tert-alkyl N-phthalimidoyl oxalates is proposed that is based on earlier pioneering investigations of Okada and Barton. Deuterium labeling and competition experiments reveal that the reductive radical coupling of tert-alkyl N-phthalimidoyl oxalates with electron-deficient alkenes is terminated by hydrogen-atom transfer
Machine Learning Approaches to Modeling the Physiochemical Properties of Small Peptides
Peptide and protein sequences are most commonly represented as a strings: a series of letters selected from the twenty character alphabet of abbreviations for the naturally occurring amino acids. Here, we experiment with representations of small peptide sequences that incorporate more physiochemical information. Specifically, we develop three different physiochemical representations for a set of roughly 700 HIV–I protease substrates. These different representations are used as input to an array of six different machine learning models which are used to predict whether or not a given peptide is likely to be an acceptable substrate for the protease. Our results show that, in general, higher–dimensional physiochemical representations tend to have better performance than representations incorporating fewer dimensions selected on the basis of high information content. We contend that such representations are more biologically relevant than simple string–based representations and are likely to more accurately capture peptide characteristics that are functionally important.Singapore-MIT Alliance (SMA
Suitability of Commercial Transport Media for Biological Pathogens under Nonideal Conditions
There is extensive data to support the use of commercial transport media as a stabilizer for known clinical samples; however, there is little information to support their use outside of controlled conditions specified by the manufacturer. Furthermore, there is no data to determine the suitability of said media for biological pathogens, specifically those of interest to the US military. This study evaluates commercial off-the-shelf (COTS) transport media based on sample recovery, viability, and quality of nucleic acids and peptides for nonpathogenic strains of Bacillus anthracis, Yersinia pestis, and Venezuelan equine encephalitis virus, in addition to ricin toxin. Samples were stored in COTS, PBST, or no media at various temperatures over an extended test period. The results demonstrate that COTS media, although sufficient for the preservation of nucleic acid and proteinaceous material, are not capable of maintaining an accurate representation of biothreat agents at the time of collection
Rollerjaw Rock Crusher
The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments
- …