Digital Commons @ the Georgia Academy of Science
Not a member yet
1290 research outputs found
Sort by
RHODAMINE-BASED FABRIC SENSOR FOR ACID RECOGNITION
No full textHalochromic dyes are important pH sensors/indicators, that can be utilized for many processes. In our past work we developed an acid fabric sensor utilizing crystal violet intercalated into the interstices of a layered material (alpha-Zirconium phosphate) using simple techniques. we are currently developing a new sensor by infusing rhodamine in an alcohol solution on a fabric. Our presentation will include data collected from powder X-Ray diffraction, FTIR, UV and other techniques as well as our sensor test results
A COMPARISON OF MICROPLASTIC CONCENTRATIONS IN FRESHWATER COLUMNS**
No full textThis research describes the capture of microplastics (MPs) in different aquatic environments within the same geographical area. It was hypothesized that areas of more stagnant water would possess higher MP quantities. Replicate samples were withdrawn from the water columns of impounded and free-flowing aquatic environments within the former Lake Demorest, GA, U.S. lakebed. Data was collected through a systematic point count. Analysis revealed that there is a significant difference in total MP counts between the locations analyzed. The results are contrary to those hypothesized, indicating higher MP counts in the flowing water environment. This may be related to the surface area drained by the catchment basins analyzed. MP fragments were also categorized by color and shape. Further analyses will be performed to determine if significant variation exists between sites and within sites by MP color and shape
jGrader: Development of a Software System to Grade Object-Oriented Programs
No full textA first course in computing (CS 1) typically involves learning the basics of expressing an algorithm in code: variables, conditionals, repetition, functions, and arrays. A second course (CS 2) typically covers the basics of object-oriented programming (OOP) where the goal is to learn how to create classes (and abstract classes and interfaces) and relationships between classes as the building blocks for developing software systems. CS 1 assignments are relatively small and it is relatively straightforward to grade them – run the code and observe if the output is correct. As a result, there is software, mostly proprietary for automating the grading process. In CS 2, the situation is different, assignments are much larger and assessment is concerned with the correct construction and composition of classes so that they collaborate to produce any number of correct results. We have developed a software system for auto-grading OO systems, jGrader. An instructor who uses jGrader must do three things in advance of grading. First, they must have a correct implementation of the software, called the solution. Next, the instructor must write test cases as individual methods in a TestSuite class and assign point values in a particular format. Finally, the instructor must run the jGrader against the solution in order to obtain the correct (expected) results. To grade student assignments, the instructor simply runs jGrader against each student solution which compares their results to the expected results. jGrader produces a report for each student showing the expected and actual output for each test case, whether the test succeed or failed, the incremental points awarded, and the final tally of points. This work describes the architecture of jGrader and the markup used to write the test cases
Modeling Automata with Classical Mechanics
No full textA model of a moving mechanical device known as automata is carried out with an analytically solved system of differential equations. The system of equations used is that of two masses coupled through a spring. The system is solved by considering a center of mass - relative coordinate approach. Once a solution of the relative coordinate is effected, each mass\u27s coordinate is obtained as a function of time. To model the automata one has to keep in mind that the spring must have an equilibrium length so as to mimic movement and to prevent the masses from overlapping. The masses in this model take the place of the automata\u27s head and tail, respectively. Once initial conditions are provided, the masses\u27 positions versus time are animated so as to simulate the automata\u27s motion
The geographic distribution and parasite infection rate of Anopheles crucians
No full textAnopheles crucians Wiedmann (s. l.) is an anopheline species complex that is distributed broadly across North and Central America and the Caribbean. It is a potential vector of Plasmodium falciparum and Plasmodium vivax, as well as a number of arboviruses. More recently, it has been implicated as a vector of Dirofilaria immitis, a microscopic nematode worm that is the causative agent of heartworm disease. Although the members of this species complex are morphologically indistinguishable as adults, it is possible to assign individuals at the species level within the complex using a previously described polymerase chain reaction (PCR) assay based on amplification of the internal transcribed spacer 2 region (ITS2). An understanding of species composition and distribution could be critical in elucidating the role that this complex may play as a vector of D. immitis. Here we describe our initial efforts to determine the distribution, composition, and parasite infection rate of members of the An. crucians complex within a community in the Southeastern United States. We employed PCR amplification of the rDNA ITS2 sequence to differentiate over 240 individuals from the An. crucians complex collected from 10 different sample locations in Lowndes county GA. We observed individuals of this complex in sympatry in multiple locations throughout the county with several of these locations exhibiting three of the species (A, C, D) in sympatry. We also employed a PCR-based assay to amplify the D. immitis-16S rRNA gene within individual mosquitoes in order to determine if there are differences in parasite infection rates between different members of this species complex. This work represents a new step in understanding An. crucians ecology in the state of Georgia. An understanding of species distribution and vector competence within the An. crucians complex could allow for the development of improved vector control strategies
STUDENT-DEVELOPED LABORATORY ACTIVITIES USING ROLLING OBJECT ON AN INCLINED PLANE TO IMPROVE STUDENT LEARNING
Get PDFThis work presents an alternative method of teaching undergraduate introductory physics laboratory. Students are presented with an experimental scenario “Rolling object on an inclined plane” and guided to develop their own laboratory activities in a studio-style setting. The overall goal of this alternative approach is to shift part of the learning responsibility to students. Through guided self-developed activities, students establish the connections between different physics concepts. Such a shift makes students active participants in the classroom, allows them to explore ideas independently, and discover through doing the exploring. Furthermore, the pedagogy is aimed at (i) motivating and actively engaging students in the learning process, (ii) helping students learn how to think independently, (iii) developing scientific ideas, and (iv) taking ownership of the learning process. Assessment of data from a 3-year pilot study showed improvement in students’ technical writing skills (30%), creative lab and research skills (6%), as well as critical thinking and quantitative skills (6%). In addition, students who participated in the study scored higher (6%) than their control group counterparts on the final exam. Other benefits are improvement in understanding of the research process and laboratory technical skills
Preliminary Analysis of the Effects of Non-target Supplemental Feeding on Camera Trap Captures of Small Mammals in Central Georgia
Get PDFSupplemental bird feeding is a widespread hobby throughout western culture. Although it brings joy to many people, bird feeding has been shown to have potentially negative effects on local bird populations and small mammalian species. To study the differences in local occurrence of native small mammalian species around bird feeders and in more distant settings, six camera traps were placed in a rural residential area in Putnam County, Georgia. Three cameras were placed facing bird feeders and three placed a minimum of 60 m away from the feeders. Species presence was recorded three days a week from 12:00 am Monday to 12:00 am Thursday between 11 November 2019 and 29 January 2020. We recorded 5,073 images of mammals during the 36 days: gray squirrels (4,264), eastern chipmunks (458), raccoons (113), Virginia opossums (65), domestic cats (54), white-tailed deer (36), gray foxes (35), field mice (22), armadillos (11), eastern cottontail rabbits (11), and domestic dogs (4). Pair-wise t-tests indicate a greater frequency of image-captures of gray squirrels, chipmunks, raccoons, opossums and cats near the feeders compared to the area away from the feeders. Foxes and deer were imaged more frequently in the area away from the feeders. Not only do bird feeders contribute to a higher visitation frequency in certain species such as gray squirrels and raccoons, species known to depredate bird nests, the elevated densities of birds and mammals in the area also attract more predators such as domestic/feral cats. This study suggests that future research is needed to investigate the effects of bird feeders on the behavior of small mammals and the magnitude to which excess predation at supplemental bird feeders affects the community structure
CARBON AND OXYGEN ISOTOPE ANALYSIS OF PLEISTOCENE AMERICAN ALLIGATOR TEETH in progress
No full textIsotopic samples from fossilized American alligator (Alligator mississippiensis) teeth were used to infer aspects of the paleoenvironment of Georgia’s Coastal Plain during the Late Pleistocene. The teeth were recovered from Clark Quarry which has been dated to the late Pleistocene. δ13C and δ18O isotopic values are typically used to distinguish ecosystem-level variations in the floral community and climate (precipitation and temperature), respectively. Carbon isotope values from fossil herbivore enamel reflect ingested vegetation from the environment with more positive values (\u3e -1‰) indicating an increased prevalence of C4 plants (e.g., warm growing season grasses and sedges) in the diet, while more negative values (\u3c -8‰) indicate elevated quantities of C3 plants (e.g., trees, shrubs, and cool growing season grasses). Oxygen isotope values from fossil enamel correlate to the aridity of an environment with positive values associating with increased evaporation (i.e., warmer conditions) and more negative values indicating cooler, less-evaporative conditions. In this study, we obtained the δ13C and δ18O values from fossil alligator teeth collected at Clark Quarry and modern teeth from Jekyll Island, GA, and Aiken, SC. The samples were analyzed using gas bench chromatography at the Center for Applied Isotopic Sciences at the University of Georgia. Although this study is ongoing, we hypothesize that the paleoenvironment of Clark Quarry was similar to the environments of the contemporary Coastal Plain of Georgia. Comparable isotopic data from the teeth of wide-ranging herbivorous megafauna at Clark Quarry (Mammuthus columbi and Bison latifrons) indicate a seasonally variable diet. New isotopic data presented here will; 1) help illuminate the dietary patterns of carnivorous taxa from Clark Quarry, and 2) due to alligators’ dependence on local aquatic environments, provide a highly detailed record of water sources around Clark Quarry
PROTECTION BY FRUCTOSE FROM DENATURATION OF PHYCOCYANIN BY OCTANOL**
No full textWe have been developing an approach to monitoring environmental water bodies for the presence of cyanobacteria. The established approach to monitoring water for aqueous vegetation and cyanobacteria is to separately extract chlorophyll for the estimation of all aquatic vegetation and to extract phycocyanin for the estimation of cyanobacteria. The approach reported here uses a biphasic system composed of octanol and water for the simultaneous extraction of chlorophyll and phycocyanin from aquatic vegetation, resulting in the separation of the two pigments into different phases; chlorophyll in the upper octanol layer, and phycocyanin in the lower aqueous layer. Such separation of the two pigments allows for more sensitive detection of either pigment. A potential flaw in this approach is that phycocyanin (a protein) exposure to octanol during the extraction process tends to reduce the blue color used to measure the phycocyanin. We have now discovered that this loss of blue color, which we assume to be due to denaturation of the phycocyanin, can be prevented by making the aqueous phase 3M fructose. Others have shown a similar protective effect of fructose against protein denaturation. The data presented here show the protective effect observed in the extraction of phycocyanin from different strains of cyanobacteria. We also show relative detection limits for phycocyanin and chlorophyll by both optical density and intrinsic fluorescence measurements. In contrast, neither glycerol nor polyethylene glycol has this protective effect. The basis for the protective effect of fructose is under investigation. This work is funded by the Biology Department of East Georgia State College
DEVELOPMENT OF AN AUTOGRADER FOR JAVA PROGRAMS
No full textGrading computer programs for student submissions in introductory computer science classes is a long and laborious task if done by hand. Autograding software are available for purchase and for free; however, they all have limitations. We have developed a program that is quite general and will work for autograding any Java program. The only requirement is that the instructor must make available to the students the exact name of the required classes and signature of methods and these must be adhered to by the students. An instructor who uses the autograder must do three things in advance of grading. First, they must have a correct implementation of the program, called the solution. Next, the instructor must write test cases as individual methods in a TestSuite class and assign point values in a particular format. Finally, the instructor must run the autograder against the solution in order to obtain the correct (expected) results. Then, the instructor runs the autograder against each student solution which compares this to the expected results. The autograder produces a report for each student showing the expected and actual output for each test case, whether the test succeed or failed, the incremental points awarded, and the final tally of points. The autograder is comprised of two main classes: TestSuite which contains the test methods and TestEngine which uses reflection to discover the test methods in TestSuite, and the runs the test methods on the student submission, evaluates the student’s results, and generates the report