Student Research Examples

Queensborough Community College Physics Department Student Research Project Examples

Analysis of SOHO Data during solar eruption

Nicholas Hunt-Walker

Coronal mass ejections that cause geomagnetic storms have been captured by the SOHO spacecraft during solar eruptions. The SOHO signal across the solar disc will be investigated for their statistical properties. A large flare event May 2 1998 was analyzed. We showed that the fluctuation exhibited oscillatory behavior minutes before the eruption and that the spatial variation decreases exponentially away from the eruption Generalization to solar flare eruption prediction was discussed.

Deep Water Chlorophyll Concentration Global Time Series Analysis

James Taylor

Chlorophyll concentration is the amount of chlorophyll produced in any time period (interval). By utilizing satellite imagery (method of pinpointing specific areas on earth’s surface and measuring energy values that may vary), chlorophyll concentration can be easily discovered. ACE (Accumulated Cyclone Energy) is a system that uses an approximation of energy used by tropical storms and is measured every 6 hours. This experiment is to discover whether or not there may be a formula or pattern of sorts utilizing chlorophyll concentration and ACE.

Auto-correlation analysis of extra-solar planet transit photometric data

Gregory Brathwaite

Extra-solar planet transit time series photometric data usually contain noise levels that are comparable to the transit signal drops. The analysis that assumes Gaussian noise and extensive data averaging calibrated to a reference star has been the traditionally used algorithm. This project studies the auto-correlation property of simulated time series data and establishes the limit of detection in terms of noise level, transit period, number of required reference stars. The data collected on HD 209458 will be used for application demonstration

Hubble constant estimation using bootstrap re-sampling

Karen Leon

It was reported that the use of t-distribution for the estimation of Hubble constant gave a value of 67 km/sec/Mpc, in contrast to the Gaussian distribution estimate of 71 km/sec/Mpc. (Gang Chen, J. Richard Gott, and Bharat Ratra, “Non-Gaussian Error Distribution of Hubble Constant Measurements”, arXiv:astro-ph/0308099 v1 6 Aug 2003). This project re-examined the Hubble constant data set compiled by Huchra with bootstrap re-sampling technique. The dataset has some 400 Hubble constant values. The bootstrap confidence interval will be used to estimate the variability of the universe’s age.

Johanna Espinoza (US citizen under-represented minority student)

Quasar without a home HE0450-2958

Johanna Espinoza

A Quasar usually gathers energy from the host galaxy. It was reported that the Quasar HE0450-2958 has no home, that is, no host galaxy. (Pierre Magain, Géraldine Letawe, Frédéric Courbin, Pascale Jablonka, Knud Jahnke, Georges Meylan and Lutz Wisotzki , “Discovery of a bright quasar without a massive host galaxy”, Nature 437, 381-384, September 2005). This project re-examined the presented data and studies the brightness fluctuation so as to get an estimate of the probability that HE0450-2958 was ejected from a collision of galaxies. HE1239-2326 and HE1503+0028, both with host galaxies, will also be studied for comparison.

Fractal Analysis of Electrostatic Potential Surface of Super-charged Green Fluorescence Protein

Nancy Gonzalez

It has been reported that super-charged Green Fluorescence Protein (GFP) can acquire superior ability to pass through mammalian cell membrane. (McNaughton et al, Mammalian cell penetration, siRNA transfection and DNA transfection by supercharged proteins, PNAS, Early Edition, March 23, 2009). It was reported that the penetration power is related to the amount of the super-charge on the GFP. The hypothesis that the membrane penetration is related to the surface complexity was tested by correlating the surface fractal dimension with the super-charge magnitude. The fractal dimension was calculated using the NIH ImageJ fractal box counting algorithm (free software from NIH available on the web). Our analysis yielded a correlation R-square of about 0.8 was obtained, consistent with the above hypothesis.

Complexity of crystal and functional states of groEL protein via cryo-microscopy

Fabian Garcia

The cryo-microscopy technique has been used by the National Center for Macro-molecular Imaging for probing the biological marco-molecule assemblies in their functional and structural states. The cryo microscopy data complements the X-ray crystallography data in the National Protein Data Bank. We showed that the GroEL protein cryo image has different statistical correlation property as compared to the X-ray crystallography data at the same resolution. The results showed that the GroEL cryo data exhibited correlation at larger length scale and suggested that structural changes of a biological marco-molecule assemble in its functional state from its crystallography state can be characterized by the auto-correlation technique and that the functional state has more order as compared to the native crystal state.

Lung CT Scan Image Analysis

Xavier Dunkley

Lung cancer kills 160,000 people each year. Lung Computer Tomography (CT) scans are able to resolve pulmonary nodules that are non-solid or partly solid. According to a 2006 Lung-CT Scans review, more work is needed for the characterization of non-solid pulmonary nodules. Another 2007 report on automated detection of pulmonary nodules also pointed out that sub-solid and complex structure nodules are difficult to detect. The purpose of this experiment is to determine if the CT-scan is a good method for determining whether a nodule is malignant when a mathematical process (Fano Factor) is used with it and give the result that reached a certain number and what that number is. The Fano Factor calculations showed that a value of 15% means that a nodule is developing.

RNA Polymerase Initial Transcriptional Motion

Osiris Hiciano

The movements of a bead that was fixed to one DNA end during RNA polymerase initial transcriptional motion can be captured in microscopy video. Newton laws of motion suggested that the DNA rotation would be a reaction of the motion of the RNA polymerase groove tracking action during promoter searching in the initial transcription process. Given that a groove is helical, longitudinal movement of a protein molecule should be accompanied by rotational motion relative to the DNA. Comparing web images/data for each system shows different fluctuations. This project used computer software to analyze and probe the fluctuations.

Electrostatic potentials of zinc finger bonds in ATRX protein and mental retardation

Marco Huerta

ATRX gene mutation causes X-syndrome mental retardation, including slow learning, genital deformation, etc. There are various reported mutations (Argentaro et al, PNAS vol 104, 2007), a mutation in an embedded zinc finger structure can be modeled with the modification of the corresponding Coulomb electrostatic potential energy. This project studied the ATRX GATA-1 zinc finger domain mutation at residue position 200 when Cysteine is replaced by Serine or Tyrosine. Our results suggested that the amino acid residue size and charge can modify the electrostatic interactions, thus affecting the protein expression levels. The electrostatic interactions in the PHD zinc finger domain mutations will also be discussed.