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A PRELIMINARY TECHNOLOGICAL ANALYSIS OF MIDDLE PRECLASSIC SHELL BEADS FROM PACBITUN, BELIZE**
No full textThe ancient Maya had one of the most complex societies in the New World. Their society was driven by the production of goods, including items made from stone, bone, and shell. Shell objects were made into various shapes including pendants, bracelets, and beads, which were likely used as both jewelry and currency. During the Middle Preclassic (900-300 BC), shells were predominantly used to make beads for jewelry. At Pacbitun, located in west central Belize, thousands of shell beads, made from marine and freshwater species, have been found in and around domestic houses. In addition to the finished beads, many were found in various stages of production. Found in association with the complete and incomplete beads were also thousands of pieces of detritus and chert drills, both used during the manufacturing process. Their association indicates that during the last millennium BC the Maya at Pacbitun were manufacturing shell beads, likely more than what was needed at the household level. This project uses microscopic techniques to identify how the beads were drilled and also uses experimental archaeology to recreate how long it would have taken to produce each bead. If the drills were used in the production of the beads exactly how they were used is not known. As a consequence, cross-cultural information is needed from neighboring regions to help figure out the technology process
QUANTITATIVELY DETERMINE BENEFICIAL AND TOXIC ELEMENTS IN NEEM LEAF EXTRACT
No full textEven though minerals play an important role in maintaining proper function of human body, heavy metals can be highly toxic even at a very low concentration. Black tea and neem leaf powder are popular beverages, but there are toxic elements present that may cause adverse health effect, e.g., chromium, bromine, cadmium, and manganese. We will focus on both the beneficial minerals (potassium and iron) and toxic elements (bromine and chromium) in different brands of green tea and neem powder. We use inductively coupled plasma mass spectroscopy to determine the concentration of different metal elements in neem powder. We will later use laser induced breakdown spectroscopy to validate our measurement. The result would provide insights on daily consumption limit of tea and neem leaf powder in order to avoid too much intake of toxic elements
INVESTIGATION OF APPARENT PARASITISM OF BIPALIUM KEWENSE BY AN UNKNOWN NEMATODE SPECIES**
No full textTwo specimens of the terrestrial flatworm, Bipalium kewense, were initially collected for teaching purposes in Monroe, Georgia. Upon closer examination, both planarians were found to be internally inhabited by nematodes of an unknown species. Light microscopy revealed that these nematodes were sexually dimorphic and ovoviviparous, but the difficult nature of nematode identification from morphological characteristics necessitates the use of molecular genetics for species identification. In the current study, putative nematodes were collected, subjected to DNA extraction and underwent polymerase chain reaction (PCR) with primers for the mitochondrial cytochrome c oxidase subunit I (COI) gene. Sequencing will be performed on the PCR products, and sequencing analysis using BLASTn software may allow for accurate species identification. Parasitism of platyhelminths by nematodes is poorly understood; thus, these observations may constitute a previously undescribed phenomenon with implications for control of invasive Bipalium species
PREDICTING THE EFFECTS OF SEA-LEVEL RISE AND INCREASING SALINITY ON THE DISTRIBUTION OF CRAYFISH ON SAPELO ISLAND, GEORGIA
No full textBarrier islands have great ecological and economical importance. Their formation has been studied in the past and is mostly thought to be caused by sea-level increasing and submerging backdune areas, leaving the dunes exposed above sea-level to form barrier islands. In addition, longshore currents and offshore shoals may also play a role in shaping and creating these islands. Increasing sea-level due to climate change is certain. Although the extent and timing are unknown, Sapelo Island in Georgia will not be spared from these effects. Loss of the existing freshwater lens and ocean inundation could greatly change freshwater availability on the island. This could have significant ecological impacts, particularly with respect to freshwater macroinvertebrates such as crayfish like Procambarus lunzi, which are complexly intertwined into the trophic web of the island. This study seeks to investigate the salinity tolerances and preferences of crayfish found on Sapelo Island, Georgia. Crayfish were collected in March, June, and September 2019. A total of 172 crayfish were divided into a freshwater group, a saline group, and an intermediate group. The saline group had salinity increased by 3 ppt each week, while the intermediate group increased by half this rate throughout the duration of the study. Preliminary results have shown that this crayfish species has a surprising tolerance of increased salinity levels, with no mortality up to 30 ppt, while beginning to decline by 36 ppt (which approximates an ocean-level threshold). This conveys the potential for P. lunzi to tolerate some increase in salinity, though they may be outcompeted by other marine organisms more readily adapted to these conditions
SUBCASTE COMPOSITION OF ATTA CEPHALOTES FORAGING COLUMNS IN A TROPICAL CLOUD FOREST
No full textAtta cephalotes (Formicidae: Attini) is a leaf-cutter ant species that occurs throughout the Neotropics. The Atta worker caste system includes three subcastes (soldiers, foragers, minims) that perform different tasks. Soldiers are large ants that defend the foraging column from large predators and remove debris from the foraging path. Foragers are smaller ants that cut leaf fragments from forests and transport fragments to the subterranean nest where they are provisioned to mutualistic Leucoagaricus fungi. Minims are the smallest subcaste members and defend the foraging column against a variety of threats. We investigated whether subcaste representation differed in day and night foraging columns of A. cephalotes in a tropical cloud forest near San Luis, Monteverde, Costa Rica in June 2019. Four separate foraging columns were filmed (three 30 s videos each) during the day (1200-1700 h) and night (1900-2300 h). The number of ants in each subcaste was counted via slow motion video replay. Two-factor ANOVA (with replication) revealed significant differences in subcaste numbers (more foragers than minims and soldiers, F2,23 = 5.03, P = 0.02) and the numbers of ants in day versus night foraging columns (more ants at night, F1,23 = 4.65, P = 0.04). Subcaste representation did not differ between day and night foraging episodes [no interaction between subcaste representation and time of day (F2,23 = 1.09, P = 0.36)]. Although night foraging columns were larger than day foraging columns, caste representation remained consistent regardless of foraging time
Analysis of Microplastics on St. Simons Island, Georgia, USA
No full textPlastic particles of many shapes and sizes are currently wreaking havoc on aquatic ecosystems across the globe. Although research behind this field of study is still developing, larger pieces of plastic often degrade into microscopic pieces 5 millimeters or smaller in length. These particles have been termed “microplastics” and are very harmful to aquatic life. Because all plastic is extremely durable and easy to manufacture, microplastics are very prevalent in waterways and oceans. The goal of this study is to analyze the prevalence of microplastics in both sediment and water samples from the coastal area of St. Simons Island, Georgia. This area is a large attraction to tourists where significant human activity occurs, and it is expected that this area will contain a high concentration of microplastics. Water samples were collected in sampling bottles, and sediments were obtained at several sites across the island in January of 2019. Sediments were dried and 100 g of the sample was mixed with 250 milliliters of salt solution and left to settle for 2 hours. Both sediment and soil samples were then vacuum filtered through 55 mm filter paper and assessed under dissecting microscopes, and microplastics were identified using a microscope and based on methods published in literature. Initial findings on the island revealed that water samples contained 2-9 microplastics per liter of water, and soil samples containing 3-20 microplastics per gram of soil. The highest quantity of microplastics was discovered in sediment samples rather than water samples. The most microplastics were found in environments in close proximity to beaches implying that sand might be accumulating the plastics and in the future act as hot spot sources. Research is currently being continued to determine change over time and whether seasonality also impacts the prevalence of microplastics in this area
A Transdisciplinary Laboratory Course Increases STEM Retention
Get PDFSTEM retention is a national challenge. Recent literature suggests that students leave STEM for many reasons including lack of context, lack of academic preparedness for entering college, and challenges with quantitative reasoning. These observations compelled us to design an introductory, transdisciplinary STEM lab course which we describe herein. This course was designed to integrate the disciplines of biology, chemistry, physics, and mathematics with activities that engage students in real-world, inquiry-based exercises and help students develop quantitative reasoning skills. Assessment showed that students in this STEM lab have higher STEM retention rates than those in equivalent disciplinary courses. The largest gains in STEM retention were seen in the 4th semester for students who took the lab as underclassmen. Additionally, student surveys indicated that students found the context of the lab compelling. In contrast, there were no significant differences in gains in quantitative literacy and reasoning or GPA among STEM lab students and students in discipline-specific labs. These results suggest that students’ engagement in applications of STEM with context might be more important for increasing retention than just focusing on academic ability alone
The Trichoplusia Ni Gut Microbiome and Its Derivation from the Phyllosphere of Its Food Plants
Get PDFInsects are the most abundant and diverse animals on planet Earth and rely on their diverse microbiomes to be so. The insect gut microbiome is vital in the growth and development of many insect species. Trichoplusia ni, the cabbage looper, is a generalist herbivore, but little is known about its microbiome. In this study, a metagenomic analysis of fecal samples was used to determine the effect of diet on the microbiome of T. ni larvae. Larvae were reared on six plant species, the microbiome was sampled from fecal material, and the phyllosphere was sampled from leaves the larvae ate. Bacteria were identified using 16S ribosomal RNA gene sequences, and diversity was quantified. Similar phyla, classes, and families were found in both types of samples, suggesting T. ni larvae primarily obtain their gut microbiome from their diet. However, the gut microbiome of T. ni larvae is not identical to the phyllosphere, particularly in relative abundances, suggesting that other factors in the insect gut environment may further modify the diversity of the microbiome. This study adds to the growing body of evidence about the implications of diet for the insect gut microbiome
EXPLORING NOVEL REACTIVITY FOR ENGINEERED MYOGLOBINBIOCATALYST: [2,3] SIGMATROPIC REARRANGEMENT OF ALLYLIC ALCOHOLS
No full textBiocatalysis is a green, sustainable process in which enzymes, whole-cells or other biological catalysts perform a required synthetic transformation in a highly efficient manner. Recently, the heme protein myoglobin (Mb) has been emerged as a robust biocatalyst. The engineered versions of Mb biocatalyst have shown to perform non-native chemical transformations such as cyclopropanation of activated and unactivated alkenes, hetero-atom insertion (S-H, N-H) reactions etc. in very high yields and in excellent selectivity. Here, we explore the reactivity of engineered Mb variants toward the [2,3] sigmatropic rearrangement of allylic acetals and thioketals to provide a simple, environmentally friendly and sustainable route to synthetically useful multifunctional organic compounds. With the above goal in mind, a feasibility study was performed using acrolein dimethyl acetal and ethyl diazoacetate (EDA) in presence of engineered Mb catalyst, Mb H64V V68A. Along with preforming these reactions under anaerobic, semi-aerobic, and aerobic conditions, this study incorporates additionally diverse experimental and controlled variables such as concentrations of the substrate and enzyme, temperature, pH, time trials, and substrate ratios. Our hope is to explore the prime conditions for this engineered myoglobin biocatalyst and determine conditions that this enzyme is able to function optimally in. Gas chromatography (GC) and Gas chromatography-Mass spectrometry (GC-MS) were used to quantify the biocatalysis reaction yields, percent conversions, and reaction rates. Nuclear magnetic resonance spectroscopy (NMR) was used to characterize the standard products and the products obtained from enzyme reactions
A TWELVE COMPONENT BIOACTIVE COMPOSITION FOR THE TREATMENT FOR Tb
No full textThe bacterium Mycobacterium tuberculosis, also referred to as MTb, infects individuals in latent, active and resistant forms. There are recommended regiments for the delivery of established antibiotics to infected individuals. These regiments focus on the oral administration and involve relatively large doses that result in significant side effects. This invention is a biodegradable implant composed primarily of an inert saturated fatty acid. The antibiotic is incorporated into the stearic acid matrix along with other constituents. The composition also includes a salt to regulate the release rate of the antibiotic, a metal-stearate structure to provide additional toxicity against MTb, a vitamin, and unsaturated fatty acids in low concentrations. As the fatty acid implant dissolves it forms a micelle that encapsulates the antibiotic. The micelle is transported to the infected area by serum and, since it is a primary energy source for the bacterium, is consumed. The antibiotic is hidden in the matrix. The biodegradable implant, which can be inserted as a single component or as spheres of different sizes (i.e. micrometer), does not have to be removed. It can also be inhaled. We have developed a relationship (signed agreement) with a company in India, which has 500 million citizens infected with Tb, to test the medical and business segments for commercialization. There is currently a patent application being prepared for the implant composition. This poster will focus on this project