Publications Resulting from CASIS-Sponsored Projects
Below, explore published research articles and book chapters that result from and acknowledge CASIS sponsorship of ISS National Lab R&D. For a more extensive list of spaceflight-related publications (not limited to CASIS sponsorship), see our ISS research publication database or International Space Station Research Results Citations on the NASA website.
The Effects of Thermal Precondition on Oncogenic and Intraspinal Cord Growth Features of Human Glioma Cells
Authors: Zeng X, Han I, Abd-El-Barr M, Anderson JE, Chi JH, Zafonte RD, Teng YD
Year of Publication: 2016
Citation: The Effects of Thermal Precondition on Oncogenic and Intraspinal Cord Growth Features of Human Glioma Cells. Cell Transplantation.
Abstract: The adult rodent spinal cord presents an inhibitory environment for donor cell survival, impeding efficiency for xenograft-based modeling of gliomas. We postulated that mild thermal precondition may influence the fate of the implanted tumor cells. To test this hypothesis, high grade human astrocytoma G55 and U87 cells were cultured under 37°C and 38.5°C, to mimic regular experimental or core body temperature of rodents, respectively. In vitro, 38.5°C-conditioned cells, relative to 37°C, grew slightly faster. Comparing to U87, G55 demonstrated greater response to the temperature difference. Hyperthermal culture markedly increased production of HSP27 in most G55 but only promoted transient expression of cancer stem cell marker CD133 in a small cell subpopulation. We subsequently transplanted G55 cells following 37°C or 38.5°C culture into the C2 or T10 spinal cord of adult female immunodeficient rats (3 rats/each locus/per temperature; total: 12 rats). Systematical analyses revealed that 38.5°C-preconditioned G55 grew more malignantly at either C2 or T10 as determined by tumor size, outgrowth profile, resistance to bolus intratumor administration of 5-fluorouracil (0.1 micromole), and post-tumor survival (P < 0.05; n = 6/group). Therefore, thermal precondition of glioma cells may be an effective way to influence the in vitro and in vivo oncological contour of glioma cells. Future studies are needed for assessing potential oncogenic modifying effect of hyperthermia regimens on glioma cells.
Description: This article describes the experimental results from utilizing mild thermal preconditioning before implantation of human glioblastoma cells into the spinal cord of rodent models. The incidence of intramedullary spinal cord gliomas (ISCG) is rising and more effective treatments are needed, thus a robust disease model is critical. However, few studies have been done on ISCG, in part, due to limited successful engraftment of tumor cells into the spinal cord of rodent models. Dr. Teng and his team hypothesized that mild thermal preconditioning (culturing the tumor cells at a slightly warmer temperature before implantation) may influence the survivability of the transplanted cells in rodents. To test this hypothesis, two different human glioblastoma cell lines were cultured at 37°C and 38.5°C. The investigators found that the cells cultured at 38.5°C grew slightly faster than those cultured at 37°C. Following culture, cells that demonstrated a greater response to the temperature difference were then implanted into the spinal cord of immunodeficient adult female rats at one of two locations. Results showed that the cells preconditioned at 38.5°C grew more robustly in both spinal cord locations than the cells cultured at 37°C. These findings demonstrate that culture temperature plays a role in tumor cell optimization for implantation into the spinal cord of rodent models, which could help researchers more successfully model ISCG.
Earth Benefit: Glioblastoma multiforme is the most aggressive and highly resistant type of glioma in the central nervous system. Although primary gliomas in the spinal cord are less common than those in the brain, the incidence of ISCG is rising. Additionally, the survival rate of ISCG is low—less than 2 years with maximum intervention—due to poor response to conventional treatments. Thus, a robust model of ISCG is critical to achieving a better understanding of the mechanisms behind ISCG and to developing more effective treatments. An increasing mortality rate from glioblastomas is driving the treatment market toward nearly $1 billion by 2022.
Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells
Authors: Jha R, Wu Q, Singh M, Preininger MK, Han P, Ding G, Cho HC, Jo H, Maher KO, Wagner MB, Xu C
Year of Publication: 2016
Citation: Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells. Scientific Reports 6:30956.
Abstract: Efficient generation of cardiomyocytes from human pluripotent stem cells is critical for their regenerative applications. Microgravity and 3D culture can profoundly modulate cell proliferation and survival. Here, we engineered microscale progenitor cardiac spheres from human pluripotent stem cells and exposed the spheres to simulated microgravity using a random positioning machine for 3 days during their differentiation to cardiomyocytes. This process resulted in the production of highly enriched cardiomyocytes (99% purity) with high viability (90%) and expected functional properties, with a 1.5 to 4-fold higher yield of cardiomyocytes from each undifferentiated stem cell as compared with 3D-standard gravity culture. Increased induction, proliferation and viability of cardiac progenitors as well as up-regulation of genes associated with proliferation and survival at the early stage of differentiation were observed in the 3D culture under simulated microgravity. Therefore, a combination of 3D culture and simulated microgravity can be used to efficiently generate highly enriched cardiomyocytes.
Description: This paper describes a method to generate cardiomyocytes (heart cells) from human pluripotent stem cells (hPSCs). The method involves differentiating hPSCs into cardiomyocytes by introducing growth factors and other inducers of cell proliferation and/or differentiation. The hPSCs were isolated in microwells, forcing them to aggregate into 3-D spheres. The spheres were then transferred to a cell culture plate and grown in simulated microgravity, where a random positioning machine continuously reoriented the gravity vector. Culturing the cells in simulated microgravity resulted in osteocytes with higher levels of contractility, maturity markers, and viability than cells cultured in standard gravity. In addition, the overall cardiomyocyte yield was up to four times higher when cultured in simulated microgravity. This comparison was also tested using human embryonic cell lines, which obtained similar results.
Earth Benefit: Heart disease is the leading cause of death in the United States and costs an estimated $207 billion each year in healthcare services, medications, and missed work. Pre-clinical studies have shown that the therapeutic use of cardiomyocytes derived from hPSCs can prevent the progression of heart failure and can function as a biological pacemaker. A reliable and safe production method for these cells may advance the timeline toward clinical human application.
A Human Pluripotent Stem Cell Model of Catecholaminergic Polymorphic Ventricular Tachycardia Recapitulates Patient-Specific Drug Responses
Authors: Preininger MK, Jha R, Maxwell JT, Wu Q, Singh M, Wang B, Dalal A, Mceachin Z, Rossoll W, Hales CM, Fischbach PS, Wagner MB, Xu C
Year of Publication: 2016
Citation: A Human Pluripotent Stem Cell Model of Catecholaminergic Polymorphic Ventricular Tachycardia Recapitulates Patient-Specific Drug Responses. Disease Models and Mechanisms 9(9):927-939.
Abstract: Beta-blockers are unsuccessful in eliminating stress-induced ventricular arrhythmias in approximately 25% of patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from these patients have potential for investigating the phenomenon, but it remains unknown whether they can recapitulate patient-specific drug responses to beta-blockers. This study assessed whether the inadequacy of beta-blocker therapy in an individual can be observed in vitro using patient-derived CPVT iPSC-CMs. A CPVT patient harboring a novel mutation in the type 2 cardiac ryanodine receptor (RyR2) was identified whose persistent ventricular arrhythmias during beta-blockade with nadolol were abolished during flecainide treatment. iPSC-CMs generated from this patient and two control individuals expressed comparable levels of excitation-contraction genes, but assessment of the sarcoplasmic reticulum Ca2+ leak and load relationship revealed intracellular Ca2+ homeostasis was altered in CPVT iPSC-CMs. beta-adrenergic stimulation potentiated spontaneous Ca2+ waves and unduly frequent, large, and prolonged Ca2+ sparks in CPVT compared to control iPSC-CMs, validating the disease phenotype. Pursuant to the patient's in vivo responses, nadolol treatment during beta-adrenergic stimulation achieved negligible reduction of Ca2+ wave frequency and failed to rescue Ca2+ spark defects in CPVT iPSC-CMs. In contrast, flecainide reduced both frequency and amplitude of Ca2+ waves and restored the frequency, width, and duration of Ca2+ sparks to baseline levels. By recapitulating a CPVT patient's improved response to flecainide compared to beta-blocker therapy in vitro, these data provide new evidence that iPSC-CMs can capture basic components of patient-specific drug responses.
Description: This article describes a patient-specific disease model to study insufficient beta-blocker response observed in certain patients with a genetic disorder that causes stress-induced arrhythmias (irregular heartbeat patterns). Arrhythmias caused by this genetic disorder are called catecholaminergic polymorphic ventricular tachycardia (CPVT). The model was created using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) derived from a CPVT patient. Beta-blockers are the first-line pharmacological therapy to prevent arrhythmias in patients with CPVT; however, for unknown reasons, such therapy is unsuccessful in about 25% of patients. In this study, Dr. Xu and her team sought to determine whether the inadequate beta-blocker response could be observed in vitro using iPSC-CMs from CPVT patients in which beta-blocker therapy was unsuccessful. For the study, iPSCs were derived from such a patient and converted into cardiomyocytes (heart cells), thereby retaining any genetic mutation(s) that cause arrhythmias and preserving the disease phenotype. A stimulant was then administered to the cardiomyocytes, triggering in vitro arrhythmias. The cellular response to beta-blocker therapy and alternative drug therapies (in comparison with that of cardiomyocytes derived from non-CPVT control subjects) was evaluated. Results confirmed that iPSC-CMs can be used to recapitulate in vitro the insufficient beta-blocker response observed in certain patients with CPVT, thus validating this patient-specific disease model. In addition, the results suggest that cardiomyocyte-specific factors may be involved in beta-blocker therapy response in CPVT patients.
Earth Benefit: CPVT is a life-threatening genetic disorder that causes stress-induced arrhythmias, which can lead to cardiac arrest. The first-line treatment for CPVT patients is beta-blocker therapy; however, for unknown reasons, it is unsuccessful in about 25% of patients. If clinicians could anticipate a CPVT patient’s response to beta-blocker therapy based on a molecular signature, it would greatly aid in decision making about the patient’s treatment plan. A patient-specific disease model, such as the one described in this article, could help researchers better understand the insufficient beta-blocker response observed in certain patients with CPVT and what factors could play a role in determining beta-blocker response.
Genetic and Environmental Models of Circadian Disruption Link SRC-2 Function to Hepatic Pathology
Authors: Fleet T, Stashi E, Zhu B, Rajapakshe K, Marcelo KL, Kettner NM, Gorman BK, Coarfa C, Fu L, O'Malley BW and York B
Year of Publication: 2016
Citation: Genetic and Environmental Models of Circadian Disruption Link SRC-2 Function to Hepatic Pathology. Journal of Biological Rhythms.
Abstract: Circadian rhythmicity is a fundamental process that synchronizes behavioral cues with metabolic homeostasis. Disruption of daily cycles due to jet lag or shift work results in severe physiological consequences including advanced aging, metabolic syndrome, and even cancer. Our understanding of the molecular clock, which is regulated by intricate positive feedforward and negative feedback loops, has expanded to include an important metabolic transcriptional coregulator, Steroid Receptor Coactivator-2 (SRC-2), that regulates both the central clock of the suprachiasmatic nucleus (SCN) and peripheral clocks including the liver. We hypothesized that an environmental uncoupling of the light-dark phases, termed chronic circadian disruption (CCD), would lead to pathology similar to the genetic circadian disruption observed with loss of SRC-2 We found that CCD and ablation of SRC-2 in mice led to a common comorbidity of metabolic syndrome also found in humans with circadian disruption, non-alcoholic fatty liver disease (NAFLD). The combination of SRC-2(-/-) and CCD results in a more robust phenotype that correlates with human non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) gene signatures. Either CCD or SRC-2 ablation produces an advanced aging phenotype leading to increased mortality consistent with other circadian mutant mouse models. Collectively, our studies demonstrate that SRC-2 provides an essential link between the behavioral activities influenced by light cues and the metabolic homeostasis maintained by the liver.
Description: This paper describes the importance of Steroid Receptor Coactivator-2 (SRC-2), a metabolic transcriptional coregulator, in the maintenance of metabolism and circadian rhythm, the daily cycle of physiological processes in organisms cued by external stimuli. Chronic circadian disruption can have a serious impact on physiological processes and increases the risk of metabolic dysfunction. In this study, Dr. York and his team examined the effects on metabolism and locomotive behavior in mice lacking SRC-2. The study builds on the team’s previous work that found that mice lacking SRC-2 exhibit altered circadian behavior and an increased risk of metabolic dysfunction and liver cancer. This publication details the contribution of SRC-2 function to maintaining the coordinated balance of metabolism, circadian biology, and optimal sleep/wake work cycles.
Earth Benefit: Chronic disruption of circadian rhythm has been shown to seriously impact physiological processes and increase the risk of metabolic dysfunction, accelerated aging, and cancer. The results of this study could help advance the development of therapeutics aimed at resolving circadian disruption and comorbidities such as metabolic syndrome, cardiovascular disease, and inflammation. As this collection of disease pathologies impacts an overwhelming majority of the U.S. adult population, research aimed at circumventing these health problems represents a potentially intangible long-term benefit to improve human health.
Guidelines for Dual Energy X-Ray Absorptiometry Analysis of Trabecular Bone-Rich Regions in Mice: Improved Precision, Accuracy, and Sensitivity for Assessing Longitudinal Bone Changes
Authors: Shi J, Lee S, Uyeda M, Tanjaya J, Kim JK, Pan HC, Reese P, Stodieck L, Lin A, TingK, Kwak JH, Soo C
Year of Publication: 2016
Citation: Guidelines for Dual Energy X-Ray Absorptiometry Analysis of Trabecular Bone-Rich Regions in Mice: Improved Precision, Accuracy, and Sensitivity for Assessing Longitudinal Bone Changes. Tissue Engineering Part C: Methods, 5(22):451-463.
Abstract: Trabecular bone is frequently studied in osteoporosis research because changes in trabecular bone are the most common cause of osteoporotic fractures. Dual energy X-ray absorptiometry (DXA) analysis specific to trabecular bone-rich regions is crucial to longitudinal osteoporosis research. The purpose of this study is to define a novel method for accurately analyzing trabecular bone-rich regions in mice via DXA. This method will be utilized to analyze scans obtained from the International Space Station in an upcoming study of microgravity-induced bone loss. Thirty 12-week-old BALB/c mice were studied. The novel method was developed by preanalyzing trabecular bone-rich sites in the distal femur, proximal tibia, and lumbar vertebrae via high-resolution X-ray imaging followed by DXA and micro-computed tomography (micro-CT) analyses. The key DXA steps described by the novel method were (1) proper mouse positioning, (2) region of interest (ROI) sizing, and (3) ROI positioning. The precision of the new method was assessed by reliability tests and a 14-week longitudinal study. The bone mineral content (BMC) data from DXA was then compared to the BMC data from micro-CT to assess accuracy. Bone mineral density (BMD) intra-class correlation coefficients of the new method ranging from 0.743 to 0.945 and Levene's test showing that there was significantly lower variances of data generated by new method both verified its consistency. By new method, a Bland-Altman plot displayed good agreement between DXA BMC and micro-CT BMC for all sites and they were strongly correlated at the distal femur and proximal tibia (r = 0.846, p < 0.01; r = 0.879, p < 0.01, respectively). The results suggest that the novel method for site-specific analysis of trabecular bone-rich regions in mice via DXA yields more precise, accurate, and repeatable BMD measurements than the conventional method.
Description: This paper describes a novel method for using the bone densitometer hardware on the ISS to analyze regions of trabecular bone (porous bone) in mice. The hardware uses the gold standard for bone mineral density imaging in osteoporosis patients—dual energy X-ray absorptiometry (DEXA or DXA). The novel method will be utilized in Dr. Chia Soo’s upcoming flight research to test the ability of drug targeting a novel pathway to prevent bone loss and promote bone growth in mice experiencing osteoporosis accelerated by microgravity. This research will utilize the unique environment of space, in which microgravity accelerates the progression of osteoporosis, to study the efficacy of the new therapy. Decreased bone mineral density in trabecular bone is a major cause of osteoporotic fractures on Earth, thus areas of bone that are rich in trabecular bone are frequently regions of interest (ROI) in osteoporosis studies. To date, there is no standardized protocol for precise and accurate assessment of bone mineral density for specific ROIs in mice. This publication describes key steps for proper mouse positioning, ROI sizing, and ROI positioning. Together, these steps increase the accuracy and consistency of results over conventional methods.
Earth Benefit: Osteoporosis, the most common metabolic bone disease, affects more than 200 million people worldwide, with 10 million people affected in the United States alone. Therapeutic approaches to osteoporotic bone loss have focused thus far on either anabolic (accelerate the building of new bone) or antiresorptive (decelerate the degradation of old bone) agents, with only one anabolic agent being FDA-approved for the temporary treatment of osteoporosis. To address the pressing need for new therapies that are both anabolic and antiresorptive, new agents that increase bone signaling and play a key role in directing stem cell differentiation to osteoblasts and inhibiting osteoclast activity are needed. In addition, osteoporosis studies that rely on the bone densitometer will realize a greater degree of certainty for their results.
The Effect of Spaceflight on the Gravity-Sensing Auxin Gradient of Roots: GFP Reporter Gene Microscopy on Orbit
Authors: Ferl RJ and Paul A-L
Year of Publication: 2016
Citation: The Effect of Spaceflight on the Gravity-Sensing Auxin Gradient of Roots: GFP Reporter Gene Microscopy on Orbit. npj Microgravity 2(15023).
Abstract: Our primary aim was to determine whether gravity has a direct role in establishing the auxin-mediated gravity-sensing system in primary roots. Major plant architectures have long been thought to be guided by gravity, including the directional growth of the primary root via auxin gradients that are then disturbed when roots deviate from the vertical as a gravity sensor. However, experiments on the International Space Station (ISS) now allow physical clarity with regard to any assumptions regarding the role of gravity in establishing fundamental root auxin distributions. We examined the spaceflight green fluorescent protein (GFP)-reporter gene expression in roots of transgenic lines of Arabidopsis thaliana: pDR5r::GFP, pTAA1::TAA1–GFP, pSCR::SCR–GFP to monitor auxin and pARR5::GFP to monitor cytokinin. Plants on the ISS were imaged live with the Light Microscopy Module (LMM), and compared with control plants imaged on the ground. Preserved spaceflight and ground control plants were examined post flight with confocal microscopy. Plants on orbit, growing in the absence of any physical reference to the terrestrial gravity vector, displayed typically "vertical" distribution of auxin in the primary root. This confirms that the establishment of the auxin-gradient system, the primary guide for gravity signaling in the root, is gravity independent. The cytokinin distribution in the root tip differs between spaceflight and the ground controls, suggesting spaceflight-induced features of root growth may be cytokinin related. The distribution of auxin in the gravity-sensing portion of the root is not dependent on gravity. Spaceflight appears benign to auxin and its role in the development of the primary root tip, whereas spaceflight may influence cytokinin-associated processes.
Description: This study sought to determine gravity's role in establishing the auxin-mediated gravity sensing system in primary plant roots. Drs. Ferl and Paul examined green fluorescent protein-reporter gene expression in the plant Arabidopsis thaliana and found that plants grown on the ISS exhibit the same pattern of auxin distribution in the root tip as plants on Earth. Thus, auxin distribution in root tips is not guided by gravity, as scientists had long assumed, and is instead an inherent developmental feature of root growth. The results presented in the paper are a compilation of imaging data from two experiments—the CASIS-funded CARA experiment (Characterizing Arabidopsis Root Attractions) flown to the ISS in 2014 and the NASA Space Biology-funded APEX03-2 experiment (Advanced Plant Experiments) flown to the ISS in 2015.
Earth Benefit: An understanding of plant structure and behavior from spaceflight experiments allows researchers to better elucidate the inherent mechanisms involved in plant growth and development. Such knowledge can contribute to growing stronger crops on Earth as well as preparations to grow plants in space on long-term spaceflight missions.
Efficient Differentiation of Cardiomyocytes from Human Pluripotent Stem Cells with Growth Factors
Authors: Jha R, Xu R-H, Xu C.
Year of Publication: 2015
Citation: Efficient Differentiation of Cardiomyocytes from Human Pluripotent Stem Cells with Growth Factors. Methods Molecular Biology (1299):115-131.
Abstract: Human pluripotent stem cells have tremendous replicative capacity and demonstrated potential to generate functional cardiomyocytes. These cardiomyocytes represent a promising source for cell replacement therapy to treat heart disease and may serve as a useful tool for drug discovery and disease modeling. Efficient cardiomyocyte differentiation, a prerequisite for the application of stem cell-derived cardiomyocytes, can be achieved with a growth factor-guided method. Undifferentiated cells are sequentially treated with activin A and BMP4 in a serum-free and insulin-free medium and then maintained in a serum-free medium with insulin. This method yields as much as >75% cardiomyocytes in the differentiation culture within 2 weeks, and the beating cardiomyocytes have expected molecular, cellular, and electrophysiological characteristics. In this chapter, we describe in detail the differentiation protocol and follow-up characterization focusing on immunocytochemistry, quantitative RT-PCR, and flow cytometry analysis.
Description: This study seeks to develop and standardize the culture conditions for the growth and differentiation of cardiomyocytes—stem cells that will enable physicians to focus on the repair and potential cure of chronic heart conditions.
Earth Benefit: Stem cells are major focus areas of medical research for use in cell-based therapies to replace, regenerate, or engineer cells, tissues, and organs to restore, maintain, or improve human health. Stem cells are ideal for disease research, drug discovery, toxicity testing, and regenerative medicine on Earth. Exploration of their cultivation in microgravity promises to enable their enhanced use for translational medical applications on Earth.
Coactivator-dependent Oscillation of Chromatin Accessibility Dictates Circadian Gene Amplitude via REV-ERB Loading
Authors: Zhu B, Gates LA, Stashi E, Dasgupta S, Gonzales N, Dean A, Dacso CC, York B, O'Malley BW
Year of Publication: 2015
Citation: Coactivator-dependent Oscillation of Chromatin Accessibility Dictates Circadian Gene Amplitude via REV-ERB Loading. Molecular Cell 60(5): 769-783.
Abstract: A central mechanism for controlling circadian gene amplitude remains elusive. We present evidence for a "facilitated repression (FR)" model that functions as an amplitude rheostat for circadian gene oscillation. We demonstrate that ROR and/or BMAL1 promote global chromatin decondensation during the activation phase of the circadian cycle to actively facilitate REV-ERB loading for repression of circadian gene expression. Mechanistically, we found that SRC-2 dictates global circadian chromatin remodeling through spatial and temporal recruitment of PBAF members of the SWI/SNF complex to facilitate loading of REV-ERB in the hepatic genome. Mathematical modeling highlights how the FR model sustains proper circadian rhythm despite fluctuations of REV-ERB levels. Our study not only reveals a mechanism for active communication between the positive and negative limbs of the circadian transcriptional loop but also establishes the concept that clock transcription factor binding dynamics is perhaps a central tenet for fine-tuning circadian rhythm.
Description: Circadian rhythm is a roughly 24-hour cycle in the physiological processes of living organisms that has both direct and indirect effects on the maintenance of health. Circadian rhythms are modulated by external environmental cues but are endogenously generated and genetically regulated. Prolonged exposure to microgravity disrupts normal circadian rhythm and enables researchers to identify and better understand the endogenous genetic regulators of the circadian cycle and how they impact human health. This research explores the function of a transcription factor implicated as a putative master genetic regulator of the mammalian circadian clock with control of physiological and metabolic processes.
Earth Benefit: Exploration of the function of this transcription factor in space, where circadian rhythms are disrupted, will advance the diagnosis of metabolic diseases and the design of therapeutics for their treatment.
Comparative Analysis of GOCI Ocean Color Products
Authors: Amin R, Lewis MD, Lawson A, Gould Jr R.W, Martinolich P, Li RR, Ladner S, and Gallegos S
Year of Publication: 2015
Citation: Comparative Analysis of GOCI Ocean Color Products. Sensors 15: 25703-25715.
Abstract: The Geostationary Ocean Color Imager (GOCI) is the first geostationary ocean color sensor in orbit that provides bio-optical properties from coastal and open waters around the Korean Peninsula at unprecedented temporal resolution. In this study, we compare the normalized water-leaving radiance (nLw) products generated by the Naval Research Laboratory Automated Processing System (APS) with those produced by the stand-alone software package, the GOCI Data Processing System (GDPS), developed by the Korean Ocean Research & Development Institute (KORDI). Both results are then compared to the nLw measured by the above water radiometer at the Ieodo site. This above-water radiometer is part of the Aerosol Robotic NETwork (AeroNET). The results indicate that the APS and GDPS processed nLw correlates well within the same image slot where the coefficient of determination (r2) is higher than 0.84 for all the bands from 412 nm to 745 nm. The agreement between APS and the AeroNET data is higher when compared to the GDPS results. The Root-Mean-Squared-Error (RMSE) between AeroNET and APS data ranges from 0.24 2 [mW/(cm srµm)] at 555 nm to 0.52 2 [mW/(cm srµm)] at 412 nm while RMSE between AeroNET and GDPS data ranges from 0.47 2 [mW/(cm srµm)] at 443 nm to 0.69 2 [mW/(cm srµm)] at 490 nm.
Description: This project was awarded in response to a CASIS solicitation promoting the use of imagery from the ISS-based sensor Hyperspectral Imager of the Coastal Ocean (HICO). When HICO became dysfunctional during the study period, the authors used other space-borne sensors, such as the Geostationary Ocean Color Imager (GOCI), to continue the research. In this paper, the authors compared ocean color data retrieved from GOCI and processed through the GOCI data processing system (GDPS) with data processed using the current standard for ocean color measurement, the Automated Processing System developed by the Naval Research Laboratory (collected from low Earth polar-orbiting satellite sensors, such as the Moderate Resolution Imaging Spectroradiometer [MODIS] and the Medium Resolution Imaging Spectrometer).
Earth Benefit: Validating the statistical accuracy of GDPS relative to APS is critical to ensure that data from the more timely collections of GOCI are applicable to the development of primary production models, carbon budgets, hypoxia, and eutrophication—the fundamental measures important to the study of water quality in coastal regions. While the results of this study were inconclusive, ongoing studies to develop and validate improved methods of monitoring water quality promise to ultimately benefit human health and the multibillion-dollar fishing and tourism industries.
Occurrence and Spatial Extent of HABs on West Florida Shelf
Authors: Amin R, Penta B, and deRada, S
Year of Publication: 2015
Citation: Occurrence and Spatial Extent of HABs on West Florida Shelf 2002-Present. IEEE Geoscience and Remote Sensing 12(10): 2080-2084.
Abstract: Harmful algal blooms (HABs) can lead to severe economic and ecological impacts in coastal areas and can threaten marine life and human health. About three quarters of these toxic blooms are caused by dinoflagellate species. One dinoflagellate species, i.e., Karenia brevis, blooms nearly every year in the Gulf of Mexico, particularly on the West Florida Shelf (WFS), where these blooms cause millions of dollars in socioeconomic damage. In this letter, we use the red band difference (RBD) bloom detection technique for detection of low backscattering phytoplankton blooms, such as K. brevis, and conduct time-series analyses of the spatial extent of these blooms using Moderate Resolution Imaging Spectroradiometer (MODIS) monthly mean data spanning July 2002 (sensor inception) to September 2014. The time-series results show that the RBD successfully detects the documented HABs in the region, illustrating the seasonal and interannual variability, including the extensive blooms of 2005 and 2014.
Description: As described above, this project was awarded in response to a CASIS solicitation promoting the use of imagery from HICO, which became dysfunctional during the study period, prompting the authors used other space-borne sensors, such as MODIS, to continue the research. In this letter, the authors report results on the seasonal formation of harmful algal blooms (HABs; e.g., red tide) off the Gulf Coast of Florida. Using the red band difference (RBD) bloom detection technique and conducting time-series analyses of the spatial extent of these blooms using MODIS data from July 2002 through September 2014, the authors show that the RBD successfully detects the documented HABs in the region, illustrating the seasonal and inter-annual variability. The results complement previous research from this team showing that the RBD technique is an effective detection tool for the species that cause HABs. The results also demonstrate the value of including the chlorophyll fluorescence channel in future satellite sensors such as those being planned for NASA’s hyperspectral PreAerosol-Cloud-Ecosystem (PACE) missions.
Earth Benefit: HABs in the Gulf of Mexico, particularly on the West Florida Shelf, cause millions of dollars in socioeconomic damage each year, threatening marine life and human health. The results of this study can be further examined not only to improve HAB detection techniques but also to understand the environmental processes that contribute to such events, ultimately benefiting human health and the multibillion-dollar fishing and tourism industries.