Concentration dependent aerosol substrates: UV-vis attenuation measurement

Ultraviolet and visible (UV/vis) light were used to determine the composition of aerosol samples taken from several military bases located in the Middle East. The aerosols were collected using a cascade impactor placing time resolved aerosols on strips of Mylar. These strips were then fed into a fiber optic UV/vis spectrometer which passes light through the Mylar strip and detects the amount of transmitted light relative to a blank standard. By measuring the light transmitted, the amount of aerosol on the Mylar strip was determined proportional to a calibration curve of standard mass depositions. The UV/vis tests were then compared to results from β-gauge analysis performed on the same samples to determine the validity of optical transparency as a substitute for electron attenuation studies. It was determined that the UV/vis data is largely comparable to the β -gauge data showing that UV/vis is a viable alternative to the β -gauge method as well as being more convenient, expedient, and easier to perform

How BRCA1 deficiency affects emergency granulopoeisis in cells

BRCA1 mutation carriers are predisposed to breast and ovarian cancer. Chemotherapy is a common treatment used in breast cancer patients. However, chemotherapy can cause damage to bone marrow. Bone marrow is responsible for the production of white blood cells, namely neutrophils, which are the first line of defense in the innate immune system2. When an infectious or inflammatory challenge presents itself, neutrophils are used up in large quantities, and the hematopoietic system in the body has to rapidly adapt to increased demands by switching from the process of steady-state granulopoeisis to emergency granulopoeisis3. Evidence has shown that BRCA1 mutation carriers who have undergone chemotherapy treatment experience low counts of neutrophils1. Additional evidence has shown that the Fanconi gene pathway contributes to genomic stability during emergency granulopoeisis, and increased Fanconi C (Fancc) gene expression contributes to emergency granulopoeisis4. Since the BRCA1 gene is downstream of the FANCC gene, a myeloid leukemia cell line (U937) was tested to determine whether BRCA1 deficiency contributes to emergency granulopoeisis as well. Different concentrations of the protein IL-1Beta was added to the cells in order to mimic the emergency granulopoeisis response, and both FANCC and BRCA1 gene expression was measured. The general trend for the expression of both genes was found to be different than has previously been reported4. Shanley S et al. Clin Cancer Res. 2006; 12(23): 7033-7038. Kolaczkowzka E et al. Nat Rev Immunol. 2013; 13(3): 159-175. Manz M et al. Nature Reviews Immunology. 2014; 14: 302-314. Hu L et al. J Clin Invest. 2013; 123(9): 3952-3966

Identifying Student Discussion in Computer-Mediated Problem Solving Chat

The COMPS project employs computer chat for students working in small groups solving classroom problems. This summer’s project aims to build computer classifiers that could effectively “look over the shoulders” of the students while working, to approximately recognize whether the students are engaging in productive discussion. Research questions are: can we write machine classifiers that can recognize reasoning, agreement, and disagreement in student discussions? Can we achieve this using only a common English vocabulary? Several thousand lines of COMPS transcripts were manually annotated. A topic modelling program was used to determine 10 main topics which appeared in the transcripts and the words in those topics. A Linear Classifier and a Support Vector Machine Classifier used the topic model to predict the annotation of each line of dialogue. To address the common English vocabulary research question, an intersection of many transcripts from different sources was combined with Google word lists and modified to accommodate text-chat conventions. In the normal vocabulary, we found f1 scores of 0.7 and above for reasoning. Using only common vocabulary, the scores were slightly lower. The next step is to train our topic model on a combination of transcripts and apply it to other transcripts from different student discussions

Optimal Portfolio Using a Genetic Algorithm

Distributing the amount of money to invest in each stock of a portfolio, while maximizing profit and minimizing risk is key. This project applied the method of a genetic algorithm in order to select an optimal portfolio. A genetic algorithm generates solutions to optimization problems using techniques inspired by natural evolution. A five stock, five years’ portfolio was utilized in order to demonstrate the efficiency of a genetic algorithm. The most important steps of this method were the fitness function and the crossover. The fitness function is a formula that determined the effectiveness of the portfolio distribution; it returned a value for each portfolio distribution and the higher the value the better the distribution. The fitness function allowed us to rank and sort the generated distributions. Then, the crossover was performed in order to see how the genetic algorithm converges towards the optimal solution. The best portfolio distributions, according to the fitness function, were used for the crossover in order to generate even better distributions. Crossover was executed a couple of times by generating new generations of distributions, until the best distribution was produced. The best distribution produced a twenty-five percent average return and its computing time was eleven minutes

Data Reduction and Analysis of Photometric Data for 48 Evolved Stars from the All Sky Automated Survey and Valparaiso University Observatory

We are carrying out research to determine the pulsation period of a specific stage in evolved, low-mass stars’ life cycles called Proto-Planetary Nebulae. Our datasets come from The Valparaiso University Observatory (VUO), as well as The All Sky Automated Survey – All Sky Catalogue (ASAS-ASC), and The All Sky Automated Survey for Supernova (ASAS-SN). These datasets complement each other to ensure that we get high-quality data for our very faint objects over long intervals of time in both hemispheres. The VUO has been observing on this project for over 20 years. The ASAS-ASC and ASAS-SN data recently became open to the public and we are using them in our analysis. We are using these three datasets to search for periodic photometric variability in 48 evolved stars. We do this by using a sophisticated period search program called Period04. Our research has found 18 objects that have one or more significant periods ranging from 37 to 208 days

Electrochemical Reduction of CO2 using Cu-Pd clusters on Graphene

In this study, five copper-palladium clusters supported on defective graphene were investigated as catalysts for the electrochemical reduction of CO2 using the first-principles approach and the computational hydrogen electrode model. The limiting potential to reduce CO2 to CH4 using five different copper-palladium catalysts was determined. Of all the catalysts studied, the best one was the Cu2Pd cluster. This cluster showed the lowest necessary overpotential (0.93 V) out of all the catalysts examined to produce CH4. Reaction pathways to produce a variety of C1 products CO, HCOOH, HCHO, CH3OH and CH4 was studied in detail for Cu2Pd. From the pathways, it was determined that it will likely produce CH4 and HCOOH

Spectroscopic Classification of Post-AGB Candidates: (Searching for Proto-Planetary Nebulae)

We have determined the spectral classification of approximately 50 candidates for post-AGB, proto-planetary nebula (PPN) objects. The candidates were chosen based on their infrared excesses as seen in the IRAS data. The spectra are of low-resolution (R~550) and were obtained with the Kitt Peak National Observatory 2.1-m and the Steward Observatory 2.3-m telescopes. Spectroscopy has permitted us to discriminate between PPNe and other objects with dust, such as pre-main sequence stars and planetary nebulae. Most of the objects appear to be PPNe, ranging in spectral type from K to B, with some of the hotter ones showing hydrogen emission lines. A number of the objects have published classifications, which we list for comparison. Some were previously classified as PPNe but a few are new identifications. We are also carrying on a photometric monitoring program of many of these objects to study light variability. This research is supported by the NSF (most recently AST-1413660)

Spectroscopic Analysis of the Kinetics of Host-Guest Chemistry Abstract

Host-guest chemistry refers to the chemistry in which a host and a guest molecule come together to form an inclusion complex. These complexes are utilized in numerous fields, including pharmaceuticals, agriculture, and cosmetics. This study focuses on the kinetic and thermodynamic behavior of a guest molecule, Brooker\u27s merocyanine, in β-cyclodextrin and its different derivatives (the hosts) at a fundamental level in an attempt to increase stability of the complexes. UV-Vis spectroscopy was used to study the kinetic stability of Brooker\u27s merocyanine\u27s unique, energy dependent isomerization pathway inside the cavity of the host molecule in solution. It was found that when the guest molecule is in acidic conditions, it will isomerize more quickly from the trans form to the cis form when inside the cavity compared to solution; also, the cyclodextrin derivatives showed minimal differences on the rate of isomerization. Under basic conditions, it is well known that the guest molecule will isomerize from the cis form to the trans form with a required input of energy in solution; however, we found that no additional UV energy is needed for isomerization in complex. Fluorescence spectroscopy was used to study the thermodynamic stability of this system to determine how well the Brooker\u27s merocyanine interacts with different cyclodextrin derivatives

Neutral Pion Asymmetries at Intermediate Pseudorapidity in Transversely Polarized p + p Collisions at √ s = 200 GeV

Among the unanswered questions pertaining to nucleon spin physics is the origin of large azimuthal asymmetries (AN ) found in π forward pseudorapidity, η, from high-energy transversely polarized p + p collisions. One possible explanation is offered by twist-3 parton distribution and fragmentation functions. In order to test these and other mechanisms, it is important to study how the asymmetry changes over a range of pion kinematics. The STAR Endcap Electromagnetic Calorimeter (EEMC) is the only RHIC detector with the ability to study AN for π available at intermediate pseudorapidity, 0.8 ≤ η ≤ 2.0. STAR recently published the first measurement of AN for π using data collected in 2006 with collision energy √ STAR collected a high-statistics dataset with transverse beam polarization at √ s = 200 GeV. This offers over a five-fold increase in integrated luminosity relative to the 2006 dataset and a chance to enhance the precision of the previous results. The primary objective of this study is to determine the quality of the data from 2012 and to estimate the final statistical uncertainty.Preliminary results from this study indicate a significant improvement over the 2006 results

Network Visualization

Network science has become increasingly popular over the last several years as people have realized that networks have the ability to represent the relationships or connections between any objects. While some networks are small and easy to gather information from, others can be very large. It can be very difficult and time consuming to map out these large networks if we collect data from all the nodes in the network. Instead of examining all nodes, we seek to collect data incrementally from a portion of the network at a time to discover the whole network. This discovery occurs by successively placing monitors which can see a local portion of the graph. We then tested all of our algorithms on four different networks. Although there was no one algorithm that did best overall, we were able to see some of the strengths and weaknesses of each on various structures of networks