Author Archives: webmaster

Variation in Nest Temperatures of the American Alligator Found on the Kennedy Space Center Merritt Island National Wildlife Refuge

Abstract: Information on nest temperatures of the American Alligator (Alligator mississippiensis) constructed in the wild is limited. Nesting temperatures during a critical thermal sensitive period determine the sex of alligators and are therefore critical in establishing the sex biases in recruitment efforts of alligators within a given community. Nest components, varying environmental conditions, and global warming could have a significant impact on nest temperatures, thus affecting future generation…

Probabilistic Survivability Versus Time Modeling

Abstract: This presentation documents Kennedy Space Center’s Independent Assessment work completed on three assessments for the Ground Systems Development and Operations (GSDO) Program to assist the Chief Safety and Mission Assurance Officer during key programmatic reviews and provided the GSDO Program with analyses of how egress time affects the likelihood of astronaut and ground worker survival during an emergency. For each assessment, a team developed probability distributions for hazard scenarios t…

Fate and Transport of Hydrophobic and Hydrophilic Cyanotoxins through Granular Activated Carbons (abstract)

Cyanobacteria (also known as “blue-green algae”) are microscopic organisms that are found in most bodies of water, which can multiply to form harmful algal blooms (HABs) under favorable conditions (i.e., rich nutrients, strong sunlight, and high temperature). Many genera of cyanobacteria are known to produce cyanotoxins such as microcystins (MCs), cylindrospermopsin (CYN), saxitoxins, and anatoxin-a. HABs have been a major health and environmental issue in Europe, Asia as well as the United States. Cyanoxtoxins in water can be partitioned into two categories (i.e., intracellular and extracellular toxins). In most cases, cyanotoxins exist intracellularly in the cytoplasm of cyanobacteria. However, when the cells die or lyse, as well as in response to stressors in the environment, intracellular toxins may be released into the water, becoming extracellular cyanotoxins. According to literature, 95% of MCs are intracellular, but only 50% of CYN is typically intracellular under typical conditions.Cyanotoxins are relatively stable under a variety of water quality conditions and can be persistent in aquatic environments. Conventional drinking water treatment plants (DWTPs), which typically utilize coagulation/flocculation/sedimentation (C/F/S) and sand filtration (SF) have been considered as safe barriers for cyanobacteria and associated intracellular toxins. However, these conventional drinking water treatment processes are ineffective in removing hydrophilic dissolved toxins. Adsorption with carbon-based media such as powdered activated carbon (PAC) and granular activated carbon (GAC) is commonly utilized as a means to remove dissolved cyanotoxins. However, guidance for the selection of operating conditions to efficiently remove various cyanotoxins by GAC does not exist. Developing an understanding of the fate and transport of cyanotoxins through porous carbon barriers is important for management of the impacts of cyanobacterial blooms on public drinking water supply. In this study, we aimed to determine the effects of hydrophilicity/hydrophobicity of cyanotoxins such as MC-LR, MC-RR and CYN on fate and transport of the cyanotoxins through virgin GAC or reactivated GAC using rapid small-scale column tests (RSSCT) (Empty bed contact time, EBCT = 15 minutes) for 18 days. The cyanotoxins were spiked into the Ohio River water having 1.4 mg/L of total organic carbon (TOC). As a result, the relatively more hydrophilic cyanotoxins showed faster breakthrough from the GACs compared to the more hydrophobic cyanotoxins.

Formation of Heliospheric Arcs of Slow Solar Wind

Abstract: A major challenge in solar and heliospheric physics is understanding the origin and nature of the so-called slow solar wind. The Sun’s atmosphere is divided into magnetically open regions, known as coronal holes, where the plasma streams out freely and fills the solar system, and closed regions, where the plasma is confined to coronal loops. The boundary between these regions extends outward as the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much o…

Observation of Chorus Waves by the Van Allen Probes: Dependence on Solar Wind Parameters and Scale Size

Abstract: Highly energetic electrons in the Earths Van Allen radiation belts can cause serious damage to spacecraft electronic systems and affect the atmospheric composition if they precipitate into the upper atmosphere. Whistler mode chorus waves have attracted significant attention in recent decades for their crucial role in the acceleration and loss of energetic electrons that ultimately change the dynamics of the radiation belts. The distribution of these waves in the inner magnetosphere is commonl…

Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability

Abstract: The terrestrial phase of the water cycle can be seriously impacted by water management and human water use behavior (e.g., reservoir operation, and irrigation withdrawals). Here we outline a method for assessing water availability in a changing climate, while explicitly considering anthropogenic water demand scenarios and water supply infrastructure designed to cope with climatic extremes. The framework brings a top-down and bottom-up approach to provide localized water assessment based on lo…

Hydroxy-fipronil is a new urinary biomarker of exposure to fipronil

Occupational medical surveillance is highly desirable in manufacturing facilities where exposure to chemicals is significant. The insecticide fipronil is generally considered safe for humans but with increasing use, exposure to fipronil is of concern. Identification of urinary metabolites of fipronil may allow development of affordable, cheap and rapid procedures for human exposure evaluation. In this study we developed a fast and easy approach for synthesis of hydroxy-fipronil, a potential urinary metabolite of fipronil. This standard was used to develop a sensitive analytical LC-MS/MS method with a limit of quantification (LOQ) of 0.4 ng/mL. Fipronil sulfone, a known metabolite, and hydroxy-fipronil were quantified in urine samples from rats treated with a fipronil containing diet. Fipronil sulfone concentration centered around 20 ng/mL, while the concentration of hydroxy-fipronil was dose-dependent ranging in 10–10,000 ng/mL and thus being a more sensitive marker of fipronil exposure. A fipronil immunoassay with cross-reactivity to hydroxy-fipronil showed a good correlation in signal intensity with LC-MS data. It was also used to demonstrate the applicability of the method for sample screening in the evaluation of exposure levels.

What’s with WET testing?

The Minnesota Wastewater Operators Association (MWOA) was created in 1956. This organization shares information with members and nonmembers through conferences, training sessions, and section meetings. The MWOA is an organization of professional operators, laboratory technicians, regulatory agencies, collection system specialists, maintenance personnel, engineers, and marketing consultants from all areas of Minnesota. Every member has a significant role in the success of MWOA. This association also helps state, regional, and local agencies make decisions that have an environmental impact on everyone. It is the association’s desire that we serve to help everyone do a better job in protecting our most valuable and renewable resource in the Land of 10,000 Lakes. Our goals are to inform and encourage others to take an active role in water quality issues and to support our members’ efforts in improving water quality. The MWOA Process Lab Committee organizes training to NPDES permitted facility laboratories and water quality laboratories on topics relating to analytical parameters and an opportunity to network with professionals in the field. Training covers various topics including sampling, analysis, data reporting, and regulatory updates.

Advancing Translational Space Research Through Biospecimen Sharing: Amplifying the Impact of Ground-Based Studies

Abstract: Biospecimen Sharing Programs (BSPs) have been organized by NASA Ames Research Center since the 1960s with the goal of maximizing utilization and scientific return from rare, complex and costly spaceflight experiments. BSPs involve acquiring otherwise unused biological specimens from primary space research experiments for distribution to secondary experiments. Here we describe a collaboration leveraging Ames expertise in biospecimen sharing to magnify the scientific impact of research informin…

Cause and Cure – Deterioration in Accuracy of CFD Simulations With Use of High-Aspect-Ratio Triangular Tetrahedral Grids

Abstract: Traditionally high-aspect ratio triangular/tetrahedral meshes are avoided by CFD re-searchers in the vicinity of a solid wall, as it is known to reduce the accuracy of gradient computations in those regions and also cause numerical instability. Although for certain complex geometries, the use of high-aspect ratio triangular/tetrahedral elements in the vicinity of a solid wall can be replaced by quadrilateral/prismatic elements, ability to use triangular/tetrahedral elements in such regions wi…

Drinking Water Microbiome as a Screening Tool for Nitrification in Chloraminated Drinking Water Distribution Systems (abstract)

Many water utilities in the US using chloramine as disinfectant treatment in their distribution systems have experienced nitrification episodes, which detrimentally impact the water quality. Here, we used 16S rRNA sequencing data to generate high-resolution taxonomic profiles of the bulk water (BW) microbiome from a chloraminated drinking water distribution system (DWDS) simulator. The DWDS was operated through four successive operational schemes, including two stable events (SS) and an episode of nitrification (SF), followed by a ‘chlorine burn’ (SR) by switching disinfectant from chloramine to free chlorine. Specifically, this study focuses on biomarker discovery and their potential use to classify SF episodes. Principal coordinate analysis identified two major clusters (SS and SF; PERMANOVA, p <0.0001) consistent with the effect of disturbance in the relative abundances of the core microbiome. The linear discriminant analysis (LDA) effect size algorithm (LEfSe) revealed both an enrichment and depletion of various bacterial populations associated with episodes of SS and SF. A supervised machine learning approach (naïve Bayes classifier) was used to classify samples from SS and SF. Classification models were trained with different types of biological and chemical datasets, including biomass (ATP), OTUs, genus-level taxonomic groups, and water quality (NH2Cl and Free-NH3). Performance of each model was examined using the area under the curve (AUC) from the receiver-operating characteristic (ROC) and precision-recall (PR) curves (AUC of 1.0 indicates an excellent classifier). AUC using biomass data were determined to be 0.596, which is equivalent to a random classification of the samples. The AUC gradually increased to 0.663 when genus-level taxonomic membership data were used in the classification model and increased significantly using OTU-level membership (0.884). Combining membership with distribution (i.e. community structure) significantly improved the predictive ability of the OTU and genus-level taxonomic model beyond that of membership only (AUC >0.976, p < 0.01). Furthermore, models were able to correctly predict 95% (AUC = 0.983, n = 104) and 96% (AUC = 0.973, n = 72) of samples of the DWDS (community structure of two published studies) and water quality datasets, respectively. The results from this study demonstrate the feasibility of selected BW microbiome signatures as predictive biomarkers of nitrification in DWDS. This new information can be used to optimize current nitrification monitoring plans.

MapX An In Situ, Full-frame X-Ray Spectroscopic Imager for Planetary Science and Astrobiology

Abstract: Microbial life exploits micron-scale disequilibria at boundaries where valence, chemical potential, pH, Eh, etc. vary on a length scale commensurate with the organisms – 10’s to 100’s of microns. The detection of accumulations of the biogenic elements C,N,O,P,S at appropriate concentrations on or in a mineral/ice substrate would constitute permissive evidence of extant life, but context is also required. Does the putative biosignature exist under habitable conditions? Under what conditions of…

Description of the TCERT Vetting Reports for Data Release 25

Abstract: The Q1Q17 DR25 TCERT Vetting Reports are a collection of plots and diagnostics used by the Threshold Crossing Event Review Team (TCERT) to evaluate threshold crossing events (TCEs). While designation of Kepler Objects of Interest (KOIs) and classification of them as Planet Candidates (PCs) or False Positives (FPs) is completely automated via a robotic vetting procedure (the Robovetter) for the Q1Q17 DR25 planet catalog, as described in Thompson et al. (2017), these reports help to visualize t…