Metal salt catalyzed carbenoids II

The interaction of diazomalonic esters with olefins in the presence of homogeneous Cu(II) catalyst species has been examined relating to olefin structure effects and catalyst structure effects using partial rate data as a method of determining the mechanistic aspects of the various reactions. It has been possible to examine the mechanistic details of cyclopropanation, C-H insertion, and both dimer forming reactions. Cyclopropanation proceeds via a transition state including olefin, copper (II), ligands, and carbene C-H insertion results from hydrogen abstraction prior to collapse of the transition state. Dimer is formed by the attack of diazo compound on the carbenoid carbon, with subsequent trans elimination of nitrogen and catalyst. The first copper catalyzed decomposition of a Δ-1 pyrazoline has been observed --Abstract, page iii

Analyzing P300 Distractors for Target Reconstruction

P300-based brain-computer interfaces (BCIs) are often trained per-user and per-application space. Training such models requires ground truth knowledge of target and non-target stimulus categories during model training, which imparts bias into the model. Additionally, not all non-targets are created equal; some may contain visual features that resemble targets or may otherwise be visually salient. Current research has indicated that non-target distractors may elicit attenuated P300 responses based on the perceptual similarity of these distractors to the target category. To minimize this bias, and enable a more nuanced analysis, we use a generalized BCI approach that is fit to neither user nor task. We do not seek to improve the overall accuracy of the BCI with our generalized approach; we instead demonstrate the utility of our approach for identifying target-related image features. When combined with other intelligent agents, such as computer vision systems, the performance of the generalized model equals that of the user-specific models, without any user specific data.Comment: 4 pages, 3 figure

Constrained K-Means Clustering Validation Study

Machine Learning (ML) is a growing topic within Computer Science with applications in many fields. One open problem in ML is data separation, or data clustering. Our project is a validation study of, “Constrained K-means Clustering with Background Knowledge by Wagstaff et. al. Our data validates the finding by Wagstaff et. al., which shows that a modified k-means clustering approach can outperform more general unsupervised learning algorithms when some domain information about the problem is available. Our data suggests that k-means clustering augmented with domain information can be a time efficient means for segmenting data sets. Our validation study focused on six classic data sets used by Wagstaff et. al. and does not consider the GPS data of the original study

Shaping the cellular landscape with Set2/SETD2 methylation

Chromatin structure is a major barrier to gene transcription that must be disrupted and re-set during each round of transcription. Central to this process is the Set2/SETD2 methyltransferase that mediates co-transcriptional methylation to histone H3 at lysine 36 (H3K36me). Studies reveal that H3K36me not only prevents inappropriate transcriptional initiation from arising within gene bodies, but that it has other conserved functions that include the repair of damaged DNA and regulation of pre-mRNA splicing. Consistent with the importance of Set2/SETD2 in chromatin biology, mutations of SETD2, or mutations at or near H3K36 in H3.3, have recently been found to underlie cancer development. This review will summarize the latest insights into the functions of Set2/SETD2 in genome regulation and cancer development

Constrained \u3ci\u3ek\u3c/i\u3e-Means Clustering Validation Study

Machine Learning (ML) is a growing topic within Computer Science with applications in many fields. One open problem in ML is data separation, or data clustering. Our project is a validation study of, “Constrained k-means Clustering with Background Knowledge by Wagstaff et. al. Our data validates the finding by Wagstaff et. al., which shows that a modified k-means clustering approach can outperform more general unsupervised learning algorithms when some domain information about the problem is available. Our data suggests that k-means clustering augmented with domain information can be a time efficient means for segmenting data sets. Our validation study focused on six classic data sets used by Wagstaff et. al. and does not consider the GPS data of the original study. We have published our code on a public SWOSU Github repository to enable other researchers to use our code as a starting point. Validation studies such as this provide great learning opportunities for students interested in working with Machine Learning, Artificial Intelligence, and other related applications. This research was funded in part by the Dr. Snowden Memorial Scholarship with the NASA OKLAHOMA Space Grant Consortium. This material is based upon work supported by the National Aeronautics and Space Administration issued through the Oklahoma Space Grant Consortium

Expanding the function of histone H3 lysine 36 methylation in Saccharomyces cerevisiae

Eukaryotic DNA is wrapped around an octamer of histone proteins, two each of H2A, H2B, H3, and H4, to form chromatin. The cell must negotiate the chromatin landscape to facilitate all DNA templated processes, including replication, repair, and transcription. The histone proteins themselves can be heavily modified by small chemical moieties like methyl, phospho, or ubiquitin groups, called post-translational modifications (PTMs). PTMs can both alter the electrostatic properties of chromatin, promoting an opening or closing of specific chromatin regions and/or as specific docking sites for effector proteins. The spatial-temporal localization of histone PTMs is highly regulated and when disrupted can lead to a variety of diseases. Methylation of histone H3 at lysine 36 (H3K36me) is a very well conserved and highly regulated histone modification laid down by the histone methyltransferase Set2 in the budding yeast S. cerevisiae. H3K36me occurs co-transcriptionally, thus marking actively transcribed genes. Though, H3K36me is associated with active transcription, it actually functions as a repressive mark, recruiting the Isw1b chromatin remodeling complex and the Rpd3S histone deacetylase complex (HDAC) to chromatin following the elongating RNA polymerase II (RNAPII) complex, preventing the binding of RNAPII to cryptic promoters within gene bodies. Here, three new aspects of H3K36me are elucidated. First, a new H3K36me binding protein is characterized, Pdp3. Pdp3 binds to H3K36me and is a member of the newly described NuA3b histone acetyltrasferase (HAT) complex. The binding of Pdp3 to H3K36me is necessary for the function of NuA3b for in the absence of Pdp3 or H3K36me, NuA3 target genes are down regulated and several other transcriptional defects are observed. Second, the role of the second plant homeodomain (PHD) finger in Rco1 of the Rpd3S complex is elucidated. Like the first PHD finger, it is necessary for Rpd3S localization to chromatin in addition to preventing aberrant transcription from occurring within gene bodies. Finally, a novel role for Set2 and H3K36me in the nutrient stress response is uncovered. Surprisingly, it is found that Set2 genetically interacts with several pathways critical for nutrient response signaling such as the Tor1, Tor2, and Slt2 mitogen-activated protein (MAP kinase) pathways. Without Set2 present, the kinetics and overall levels of signaling in these pathways is altered. Together, the work in this dissertation expands our understanding of the role H3K36me plays in transcription and cellular signaling and hopefully will guide future work in higher eukaryotes to better understand and treat human diseases.Doctor of Philosoph

Helping Low-Income Families Manage Childhood Asthma: Solutions for Healthcare & Beyond

Asthma is the most common childhood chronic illness, affecting more than seven million children nationwide. Managing chronic illness in a child is challenging for any family. Among the challenges is constant fear of an acute episode, a complex regimen of medications given daily or many times each day, frequent changes in prescriptions or dosages, coordinating multiple healthcare providers, and helping a child have as "normal" and active a childhood as his/her condition allows. Low-income children of color bear a heavier asthma burden than their white or more affluent peers. Those low-income children who live in urban areas such as Baltimore, Chicago, Los Angeles, and New York are particularly vulnerable. Families with limited resources struggle to provide their children with asthma the support that these children need

Aerodynamic Analysis of Simulated Heat Shield Recession for the Orion Command Module

The aerodynamic effects of the recession of the ablative thermal protection system for the Orion Command Module of the Crew Exploration Vehicle are important for the vehicle guidance. At the present time, the aerodynamic effects of recession being handled within the Orion aerodynamic database indirectly with an additional safety factor placed on the uncertainty bounds. This study is an initial attempt to quantify the effects for a particular set of recessed geometry shapes, in order to provide more rigorous analysis for managing recession effects within the aerodynamic database. The aerodynamic forces and moments for the baseline and recessed geometries were computed at several trajectory points using multiple CFD codes, both viscous and inviscid. The resulting aerodynamics for the baseline and recessed geometries were compared. The forces (lift, drag) show negligible differences between baseline and recessed geometries. Generally, the moments show a difference between baseline and recessed geometries that correlates with the maximum amount of recession of the geometry. The difference between the pitching moments for the baseline and recessed geometries increases as Mach number decreases (and the recession is greater), and reach a value of -0.0026 for the lowest Mach number. The change in trim angle of attack increases from approx. 0.5deg at M = 28.7 to approx. 1.3deg at M = 6, and is consistent with a previous analysis with a lower fidelity engineering tool. This correlation of the present results with the engineering tool results supports the continued use of the engineering tool for future work. The present analysis suggests there does not need to be an uncertainty due to recession in the Orion aerodynamic database for the force quantities. The magnitude of the change in pitching moment due to recession is large enough to warrant inclusion in the aerodynamic database. An increment in the uncertainty for pitching moment could be calculated from these results and included in the development of the aerodynamic database uncertainty for pitching moment