Young Scholars Research Program
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The Young Scholars Reseach Program program offers students opportunities for exploration and discovery through tailored, cutting-edge research projects. Students receive mentorship in scholarly paper writing under the guidance of our dedicated faculty, resulting in the development and publication of professional research papers within their chosen fields.
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Publication Analysis of the Exoplanet Host Star Candidacy of TOI 5938.01(George Mason University, 2023-10) Harish, Harisudhan; Plavchan, PeterThis study aimed to confirm if there is an exoplanet for TOI 5938.01. This goal was accomplished by using AstroImageJ to run multi-aperture photometry to generate a light curve for the TOI and then analyzing the light curve for the results. Through the light curve generated, I was able to confirm that TOI 5938.01 has a planet. This result is important for future missions, as the list of known exoplanets will have expanded with my analysis.Item Evaluation of Antithymocyte Globulin and Basiliximab as Induction Therapy in Kidney Transplant Recipients(George Mason University, 2023-12) Bhalla, Arnav; Katasani, Hamsini; Herdrich, KyleBackground The roles of induction and maintenance therapies are becoming increasingly critical in promoting the long-term success of renal transplants and the reduction of post-surgery acute rejection. From 1998 to 2007, 78% of kidney transplant recipients (KTR) in the U.S. received immunosuppressive induction therapy [1]; fast forward to 2014, that percentage increased to 90%. [2] The three most popular antibodies used in induction therapy for KTRs in the U.S. are Antithymocyte Globulin (“Thymo”), Basiliximab (“Simulect”), and Alemtuzumab (“Campath”). According to Koyawala, et al., rabbit Thymo is used in approx. 50% of indication therapies for KTRs, Basiliximab 20%, and Campath 15%. [2] Thymo is a polyclonal antibody and lymphocytedepleting agent sourced from rabbits or horses that were immunized with human thymocytes. [3] By reducing the count of T cells, Thymo prevents KTRs’ white blood cells from rejecting the transplanted organs. Rabbit Thymo was approved in 2017 for KTRs’ induction therapy. Before then, Basiliximab was the only FDA approved induction agent for KTRs in the U.S. Basiliximab is a chimeric mouse-human antibody and an interleukin-2 receptor antagonist (IL2RA) agent that decreases patients’ T cell production by blocking certain receptors on T cells. On the other hand, Campath is a lab-produced humanized rat monoclonal antibody that works to deplete capable immune cells, T and B cells. [4] In terms of efficacy, outcomes, and side effects after renal transplantation, Thymo and Campath are found to be most effective at preventing rejection among high-risk kidney recipients; however, Thymo is also correlated with higher rate of infections, cancer, and lymphoproliferative disease incidents. [3, 5, 6] In contrast, Basiliximab recipients showed the lowest rate of infections and side effects. Cost-wise, Basiliximab is a more cost-effective alternative to Thymo for standard and low-risk KTRs. [3, 5] An analysis of ten randomized controlled trials (over 1200 patients included) compared the efficacy of Campath relative to IL2RAs (Basiliximab and Daclizumab) and Thymo. [4] The 2012 study found that Campath resulted in a lower rate of biopsy-proven acute rejection than the induction using IL2Ras, but there was no significant difference when compared to rabbit Thymo. The study also found no apparent difference in terms of graft loss, patient death, and new-onset diabetes mellitus among the induction agents. On the other hand, a 2019 study by Alloway et.al. examined the results of two international randomized trials (508 KTRs included) to compare the efficacy of rabbit Thymo vs. Basiliximab. [7] The study found that 1 year and 5 years after transplantation, the rate of reported treatment failures was nearly 11% lower in rabbit Thymo recipients compared to the Basiliximab recipients. Furthermore, the 10-year data of the rabbit Thymo recipients showed a 10% lower acute rejection rate than the Basiliximab recipients. One new development in renal induction therapy is the combined use of Thymo and Basiliximab. The combined therapy has been used as a feasible alternative for patients who could not take full dosage of Thymo due to various health reasons such as thrombocytopenia, leukopenia, or cytokine release syndrome. Since Basiliximab on its own was sometimes considered too weak to prevent graft failure, an induction therapy consisting of both Thymo and Basiliximab became a plausible option. A 2023 retrospective study of 80 KTRs showed that one-year graft survival rate was not significantly different between the Basiliximab recipients and the Thymo-Basiliximab combined recipients, suggesting a positive support for the dual induction therapy consisted of low-dosage Thymo and Basiliximab. [8] On the other hand, a national study published in 2021 by Lam et. al [9] concluded that patients who received the Thymo-Basiliximab combined induction therapy have an increased risk of graft loss and mortality five years after transplantation when compared to those who received Thymo-only induction therapy. This study analyzed data of over 150,000 KTRs from a national registry between 2005 and 2018. The other new trend worth noting is the exclusion of steroids from maintenance therapy. Due to their anti-inflammatory and immunosuppressive properties, steroids have historically been used to prevent acute rejection after renal surgeries. However, long-term steroid use could cause adverse side effects such as osteoporosis, cataract, and higher cardiovascular and infection risks. A 2016 study by Haller et al. found that the acute rejection risk was noticeably higher for patients who were subjected to steroid reduction or withdrawal. [10] However, a couple other studies found steroid reduction techniques to be safe and effective as steroid-based maintenance therapy, and that steroid withdrawal are especially beneficial to certain patient groups, including African American recipients, sensitized patients, and pediatric patients. [11, 12] The purpose of this study is two-fold: One is to evaluate whether the combined Thymo-Basiliximab induction therapy is as effective as other regimens (Thymo, Simulect, Campath) in preventing graft failures and patient death. The other is to examine whether the steroid-free maintenance therapy is as effective as the steroid-included maintenance therapy in graft failures and patient mortality.Item Evaluation of Pancreatic Re-transplantation Outcomes(George Mason University, 2023-12) Sharma, Grace; Yallapragada, VinayBackground In this literature review, we will cover details of prior research. This review includes studies published after 2012. There is extremely limited information available about the outcomes of pancreas retransplants. Most studies in this field are single-center reports with small datasets. This literature review can be divided into three main areas: 1. Analysis of graft survival in different forms of pancreas transplants 2. Analysis of patient survival in different forms of pancreas transplants 3. Review of recommendations to consider pancreas retransplants for patients Several studies have identified the graft survival rates of retransplant patients and compared them with graft survival rates for other pancreas transplant patients. In [7], authors compared the graft survival between 187 primary transplant and 26 retransplant patients, noting that graft survival rates were lower amongst retransplants than primary transplants. In 2018, Gasteiger et al. [4] concluded that graft survival in first-time retransplant patients was similar to graft survival amongst patients that received more than one retransplant. In [1], Hollinger determined that graft survival was similar amongst patients who received an early retransplant and a delayed retransplant. Most studies analyzing graft survival rates in pancreas retransplants are single-center reports studying less than 50 patients each. In 2015, Siskind et al. [6] reviewed more than a thousand retransplants in a larger database, UNOS; the authors determined that graft survival in retransplant patients was significantly lower than primary transplant patients. Most studies determining graft survival rates of retransplant patients also studied patient survival rates. In [2], the authors conducted an in-depth analysis of retransplants done after 2003 and determined that there was no significant difference between the patient survival rates of primary transplant and retransplant patients. In [7], the authors concluded that patient survival was not different for primary transplant patients and retransplant patients. The analysis on the UNOS database revealed that patient survival was greater in the retransplant group than the primary transplant group [6]. Most work in this field has concluded by supporting pancreas retransplants as a viable option for patients. In [5], the authors state that retransplants are feasible and that it should be considered for diabetic patients who have lost their first pancreas. In [3], where the authors analyzed 18 retransplant patients, the study concluded by determining that retransplants are a safe and effective procedure. In [7], the authors had determined that retransplants had lower graft survival than primary transplants yet concluded that it can be offered to diabetic patients. However, in [6], the authors analyzed over 1,000 retransplants and concluded that retransplants should not be considered for all patients.Item Evaluation of Transplanting Organs from Drowned Donors(George Mason University, 2023-12) Han, Caleb; Ho, Seraphina; Jung, IsaacBackground Donor-derived infections, transmitted from organ donor to organ recipient, while infrequent, often lead to the death of the organ recipient because of their compromised immune systems. A recent CDC publication reported that organ transplants from drowned organ donors potentially exposed to environmental molds (e.g. Scedosporium) through the aspiration of water may lead to invasive mold infections (IMIs) in the recipients of the exposed organs [1]. Scedosporium, a pathogenic soil-dwelling saprophyte often found in polluted water bodies, has emerged as the most common cause of drowned donor derived invasive fungal infections (IFIs), and can manifest as pneumonia, CNS disease, and dissemination [2]. Despite the significant developments made in regards to understanding IMIs from drowned donors, between 2000 and 2016, out of the 61 published cases of scedosporiosis following solid organ transplantation (SOT), 36 of these cases resulted in death, a high mortality rate of 59% [3]. Furthermore, in 2023, Xiaoli Lin and colleagues analyzed the perioperative infections, microbiological results, early transplant outcomes, and first-year clinical outcomes of 38 drowned donor renal recipients. The analyses revealed that when compared to the control group, drowned donors exhibited a significantly higher rate of positive fungal cultures (36.84% vs.13.15%,), and recipients displayed an increased prevalence of gram-negative bacteria (23.68% vs.5.26%) as well as multidrug-resistant GNB infections (18.42% vs. 3.95%) [4]. Additionally, studies regarding IMIs have identified a correlation between the necessary immunosuppressive medications taken by SOT recipients required to prevent organ rejection, and increased risks of contracting invasive mold infections (IMIs) [1, 5]. Currently, one of the most pressing issues in transplantation is the shortage of organs. To address this challenge, there is a growing emphasis on promoting the use of deceased donors, including drowned donors, in organ transplantation, despite the risk of IMIs. Due to persistent shortage of kidneys and livers for transplantation, most transplant centers have been considered to obtain and use the organs even from drowned donors [6]. However, there has been no report on the effects of kidney and/or liver transplants from drowned donors in light of graft failure and recipients’ mortality rates. Thus, studies on the outcomes of drowned donor kidney and liver transplants are required in comparison to other common accidents and injuries (i.e. Drug intoxication, Gunshot wound, Blunt injury, and Asphyxiation) to understand potentials of the drowned donor kidney and liver transplantation as another transplant resource. OBJECTIVE We aimed to investigate differences in graft failure and patient mortality rate between drowning, gunshot, drug intoxication, asphyxiation, and blunt injury.Publication Ground based light curve follow up confirmation of the planetary nature of TOI 3506.1(George Mason University, 2023-10) Kanigicherla, Aarushi; Plavchan, PeterThe Transiting Exoplanet Survey Satellite (TESS) mission gathers data for thousands of candidate exoplanets and their host stars (Zhang et al., 2022). In this paper we present research on candidate exoplanet TOI 3506.01, which orbits host star TOI 3506.01. The goal of this paper is to provide a ground based follow up of the planetary nature of TOI 3506.01. We took 249 exposures with the GMU 0.8 m telescope and reduced them, then we conducted ground based multi aperture photometry using AstroImageJ to generate a light curve. In addition, we plotted residuals and the fluxes of our target stars and adjusted trends within the data. We confirmed the planetary nature of TOI 3506.01, due to the visible transit on the ground based light curve.Publication Ground based light curve follow up observations and false positive testing for TESS Object of Interest 3553.01(George Mason University, 2023-10) Kanigicherla, Aarushi; Plavchan, Peter; Collins, KevinThe Transiting Exoplanet Survey Satellite (TESS) mission gathers data for thousands of candidate exoplanets and their host stars (Zhang et al., 2022). In this paper we present research of TOI 3553, which is orbited by candidate exoplanet TOI 3553.01. The goal of this paper is to provide a ground based follow up of the planetary nature of TOI 3553.01. We also will confirm if TOI 3553 is a near eclipsing binary (NEB). We took 303 exposures with the GMU 0.8 m telescope and reduced them, then we conducted ground based multi aperture photometry using AstroImageJ to generate a light curve. Lastly, we conducted an NEB analysis on TOI 3553. We determined that TOI 3553.01 is not a near eclipsing binary. Due to the fact that the transit did not happen during the expected time, we did not confirm the planetary nature of TOI 3553.01.Publication Ground Based Light Curve Follow-Up Validation Observations of TESS Object of Interest (TOI) 4620.01(George Mason University, 2023-10) Cao, David; Pich, Leo; Plavchan, PeterThe TESS satellite scans the sky for possible exoplanets using the transit photometry method. Any possible exoplanet candidates are marked as Objects of Interest and selected for follow-up ground-based observation. This paper presents the results of follow-up ground based observation conducted on the candidate exoplanet TOI 4620.01. The goal of this observation was to determine if the transit detected for TOI 4620.01 occurred near the predicted star, and at the predicted time, with the predicted duration and orbital depth. Our observations showed that the transit occurred with all of the expected characteristics. This indicates that TOI 4620.01 is likely an actual exoplanet.Publication Ground-Based Follow-Up Observations of TESS Object of Interest TOI 3779.1(George Mason University, 2023-10) Olaiz, Estefanía; Plavchan, PeterThis study presents the identification of an eclipsing binary system consisting of a 1.618-day orbital period, as determined through follow-up observations of the TESS Object of Interest (TOI) 3779.01 (TIC 275527293). Leveraging data from the Transiting Exoplanet Survey Satellite (TESS) and ground-based observations from George Mason University's 16″ Dobsonian Strickland telescope in Fairfax, VA, Multi-Aperture Photometry using AstroImageJ (AIJ) was performed for photometric measurements, light curve plotting, and transit analysis. The resulting light curve and validation tests suggest TOI-3779.1 is likely an eclipsing binary system. All outcomes, including light curves, detrended data, and measurements, were submitted to ExoFOP (Exoplanet Follow-up Observation Program) for further examination and archiving.Publication Ground-Based Light Curve Follow-Up Validation Observations of TESS Object of Interest 5691.01(George Mason University, 2023-10) Tong, Adam; Plavchan, Peter; Kriel, AidenContext. Transiting planets around host stars is crucial to understanding the formation and evolution of planetary systems. Through TESS, TOI-5691.01 was identified around a host star, TOI-5691. Aims. The focus of this paper is on validating the transiting method leading to the identification of TOI-5691.01. We present the characterization and possible confirmation of a transiting exoplanet around a host star Methods. Using the software Lightkurve, we create TESS light curves. Through transit photometry, we also created a ground-based light curve and performed analysis using the software AstroImageJ to validate the transit of our candidate exoplanet. Due to the limited scope of our research, we did not perform other detection methods such as radial velocity measurement using a high-resolution spectrograph, and false-positive analysis using Vespa.Publication Ground-based light curve follow-up validation observations of TESS object of interest TOI 3616.01(George Mason University, 2023-10) Bhardwaj, Tanush; Plavchan, PeterTESS object of interest TOI 3616 was investigated using George Mason University’s ground-based telescope. The goal of this investigation is to provide follow-up research on TOI 3616.01. Using AstroImageJ, a light curve was generated to provide more insight into the flux data. Due to the large amount of exposures needed to be removed, the data remains inconclusive. However, the generated light curve may produce viable data for future analyses.Publication Ground-based light curve follow-up validation observations of TESS object of interest TOI 3737.01(George Mason University, 2023-10) Yang, William; Plavchan, PeterContext: The study focuses on TESS Object of Interest (TOI) follow-ups, by light curve analysis of data taken by ground based observatories. TESS has provided a wealth of photometric data, but ground-based observations are essential to refine parameters and confirm planetary candidates. Aims: Our primary goal is to enhance the understanding of a TOI by conducting a meticulous ground-based follow-up. Through precise light curve analysis, we aim to confirm the planetary nature of TOI and refine its orbital parameters, ultimately contributing to the characterization of a possible exoplanet. Methods: We collected high-quality ground-based photometric data using observatory telescopes and instruments. By reducing and analyzing these data, we carried out a light curve analysis to validate TOI's planetary status.Publication Ground-based light curve follow-up validation observations of TESS object of interest TOI 3779.01(George Mason University, 2023-10) Joseph, Samuel T.; Plavchan, PeterThe objective of this study is to determine if TESS object of interest TOI 3779.01 is an exoplanet which is currently classified as a possible candidate in the NASA Exoplanet Archive. The raw telescope data of TOI 3779.01 was collected from the GMU Observatory. These images were reduced, plate solved, and aligned using AstroImageJ to generate a light curve of TOI 3779.01’s transit. There is a dimming of the host star during the transit period, however, since there was notable light pollution during the observational night and nearby reference stars failed the NEB (Nearby Eclipsing Binary) check, the aperture could have been contaminated. To find the planet-to-star radius ratio of TOI 3779.01 we first used the transit depth (6.93 ppt) calculated from our transit model in AstroImageJ to get a ratio value of 0.083246. Using the transit model ratio and transit depth, the radius of TOI 3779.01 is 0.09152 R☉(stellar radius). This value comes close with two other estimates: the first is using the TESS predicted transit depth (8.8) which yielded 0.103189 R☉ and the other is a python probabilistic model which predicted 0.037. These calculations assumes that the stellar radius of the host star is 1.1 R☉. Based on the large radius, we classified TOI 3779.01 as a Hot Jupiter. However, since the aperture was contaminated, the findings of this study can be further used by the TESS team to do more research employing other methods like spectroscopy and chromaticity.Publication Ground-based Light Curve Follow-up Validation Observations of TESS Object of Interest TOI 3792.01(George Mason University, 2023-10) Ellis, Abigael; Plavchan, PeterThe goal of this study was to further confirm, characterize, and classify TESS Object of Interest (TOI) 3792.01. This was done by analyzing the stellar light curve of this object. We remotely obtained ground based data from the Observatory at George Mason University. The data was visualized using the software AstroImageJ. Although the data was skewed due to a fluctuating thin cloud cover and an 8 hour uncertainty period when observed by TESS, we found that by using less obscured reference stars and the WIDTH_T1 Detrending Parameter, we were able to find data clear enough to work with. However, this data still retained a scatter percentage (RMS) of 1.8%. While comparing the estimated light curve to the data collected, we found that the RMS dropped suddenly to 1.28% during an 8 hour period. However, this is obviously still imperfect. Therefore, the results for this study are inconclusive but suggestive. Though no direct conclusion can be reached at this time, more data should be collected to compare to the current data in order to confirm TOI 3792.01 as a transit.Publication Ground-based light curve follow-up validation observations of TESS object of interest TOI 3877.01(George Mason University, 2023-10) Pierson, Kevin; Helm, Ian; Plavchan, PeterContext Exoplanets have been a fairly recent topic of interest in the field of astronomy, only having been discovered for a few decades. However, despite the youth of their discovery, they’ve been a crucial part of astronomical studies; especially those orbiting their parent star in the “Goldilocks Zone”. These Earth-like planets could potentially serve as future homes for humanity, which is why they’re a huge topic of interest. Aims The goal of this investigation is to study data regarding the star Tess Object of Interest (TOI) 3877 to confirm suspicions that it is an exoplanet transiting in front of its star that is responsible for the dimming of its light levels. Methods The app AstroImageJ will be used to study and interpret the data of TOI_3877 by taking multiple images captured during the night of observation, sorting them based on shutter settings and exposure length, aligning them, and finally by cutting out outside noise to gather the light levels taken over the period of exposure and making a light curve graph.Publication Ground-based light curve follow-up validation observations of TESS object of interest TOI 4620.01(George Mason University, 2023-10) Chen, Zirui; Plavchan, PeterThe Transiting Exoplanet Survey Satellite (TESS) is a space telescope for NASA's Explorer program, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission. During its first two years in orbit, the TESS spacecraft concentrated its gaze on several hundred thousand specially chosen stars, looking for small dips in their light caused by orbiting planets passing between their host star and us. Because of the low spatial resolution of its cameras, TESS is expected to detect several false positives (FPs). It can identify as NEB (Nearby Eclipsing Binary), BEB (Blended Eclipsing Binary) or EB (Eclipsing Binary).We use AIJ(AstroImageJ) to find the TOI 4620.01 and create the lightcurve. We found that the brightness of the planet tends to decrease around the predicted time. After that we identify there is a transit.Publication Ground-based Light Curve follow-up Validation Observations of TESS Object of Interest TOI 5147.01 with V-Shaped Profile(George Mason University, 2023-10) Xiao, Cindy; Plavchan, Peter; Collins, KevinContext The best-fit light curve model helps determine various characteristics of the exoplanet, such as its orbital period, radius, and sometimes even its atmospheric properties. Aims Conducting an analysis and interpretation of light curves derived from the provided dataset. The dataset contains various parameters for each observed slice of data, including saturated labels, Julian Dates, Heliocentric Julian Dates, Barycentric Julian Dates, air mass, object altitude, CCD temperature, exposure time, object coordinates, full width at half maximum (FWHM), source and sky radii, relative flux measurements, and associated errors for multiple comparison stars (C1 to C11) and the target star (T1). Methods Methodology employed for data processing, the extraction of photometric information, and the calculation of relevant parameters for each star in the dataset. The photometric measurements are compared to established values to validate the accuracy and consistency of the obtained results.Publication Ground-based Light Curve Follow-up Validation Observations of TESS Object of Interest TOI 5938.01(George Mason University, 2023-10) Zeng, Alan; Plavchan, PeterThe Transiting Exoplanet Survey Satellite (TESS) has been extensively used to discover new exoplanet candidates. This ground-based follow-up aimed to provide further data and confirm the existence of TESS Object of Interest (TOI) 5938.01. This was done by using AstroImageJ to create and analyze the light curve. Observation data of TOI 5938.01 was obtained from George Mason University and was reduced and plate-solved using AstroImageJ. After generating a light curve using AstroImageJ, it is inconclusive whether or not there is a transit. This study aims to provide a foundation for future work that is necessary to determine if TOI 5938.01 has a transit or not.Publication Ground-based Light Curve Follow-up Validation Observations of TESS Object of Interest TOI-4064.01(George Mason University, 2023-10) Howton, Cecilia; Plavchan, PeterThere have be 6,788 exo-planet candidates found by TESS alone, yet only 383 of them has been confirmed. We aimed to aid in the validation of these possible exo-planets, by checking for false positives (NEBs/EBs) and by using the transit method to analyze TOI 4064.01. Ultimately we did not receive a detection of a transit, possibly due to the dimness of the star or noise in our exposures.Publication Ground-based light curve follow-up validation observations of TESS object ofinterest TOI 3576.01(George Mason University, 2023-10) Suphian, Tayba; Plavchan, PeterTESS is a satellite dedicated to finding exoplanets that may be orbiting nearby stars. Since its launch, it has discovered more than 6000 TO Is, or Targets of lnterests. The goal of this study is to confirm that TOI-3576.01 is an exoplanet. We used multi-aperture photometry to analyze data and extract a light curve. Then, we analyzed the light curve in order to verify that there was a transit.Publication Ground-based light curve follow-up validation observations on TESS object TOI-5237.01(George Mason University, 2023-10) Riotto, Allen; Kriel, Aiden; Plavchan, PeterThe goal of this observational study is to perform follow-up investigations on a potential exoplanet discovered by the Transiting Exoplanet Survey Satellite (TESS), and validate if the findings by TESS are accurate. Potential exoplanet TOI-5237.01, discovered in 2022, is located 604 parsecs away from Earth, and our observational study attempts to confirm the existence of this exoplanet. This process would involve using George Mason University’s 0.8m telescope, ansvr, and AstroImageJ to create a seeing profile and light curve to determine if an exoplanet transit is occurring. If one is detected, follow-up observations and false-positive validation can occur to account for any potential error. Unfortunately, our findings lacked sufficient data to make any concrete claims, as not enough measurements were gathered during the predicted ingress and egress. It is interesting to note that a transit was detected, and even though insufficient results were obtained from this investigation, future investigations can be performed to discover the origin of the detection.