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COMPARISON OF DIATOM COMMUNITIES IN LOW-IMPACT STREAMS IN MIDDLE GEORGIA
No full textProtecting ecological integrity of aquatic systems and reducing years of nutrient increase are major goals of the Clean Water Act. Reference streams serve as comparisons to streams with questionable ecological status, with reference criteria being set based on remaining at or below the 25th percentile from the desired chemical concentrations. Middle Georgia, within EPA region IV, has criteria set for total phosphorus (TP) and total nitrogen as 0.037 mg/L and 0.69 mg/L, respectively. Algae are sensitive bioindicators, having short generation times and significant bottom-up control. The goals of this study were to compare water quality indices for two low-impact streams in Middle Georgia. Tobler Creek, enclosed within the property of the historic Andalusia Farm, is a recovering stream after years of agricultural activities stopped in 1980. Closely positioned, Murder Creek is located within the Oconee National Forest, which is protected. In 2011, Tobler Creek met reference criteria for nitrate nitrogen, but not for TP, it took another 11 years to meet reference criteria for both nutrients. Periphyton samples from both streams were collected in 2022 following standard protocol and assessed with community indices. Diatoms dominated primary communities. Species richness was significantly higher in Tobler Creek 2022 than in 2011 (χ2=42.09, p\u3c0.01), but for both years stayed below species richness and diversity documented for Murder creek. Estimating total ecological health, the Multi-Metric Index was significantly lower for Tobler Creek (χ2=18.46, p\u3c0.01), indicating that despite a 42-year recovery from agricultural use, the stream has not achieved regional expected criteria. For the recovering stream, % SSN (surirelloid, nitzschoid, naviculoid) taxa were significantly higher (χ2=101.25, p\u3c0.01), indicating that ecological degradation was driven by sedimentation and not nutrients. These findings suggest that while limiting nutrients can help improve trophic status of a stream, other factors could decrease water quality in those dynamic aquatic habitats
THE POPULATION GENETICS OF THE WHITE TUBERCLED CRAYFISH (PROCAMBARUS SPICULIFER, LECONTE 1856) FROM THE OCONEE RIVER DRAINAGE OF GEORGIA**
No full textThe southeastern United States is a global hotspot in terms of freshwater biodiversity and is home to nearly one-third of the over 640 species of crayfish known worldwide. Unfortunately, over 30% of crayfish are threatened with extinction with the biggest threats being habitat loss, the introduction of invasive species and habitat fragmentation. These threats are exemplified in Georgia which is home to over 70 different crayfishes and more than 4,500 man-made dams. The White Tubercled Crayfish (Procambarus spiculifer, LeConte 1856) is a common stream dwelling crayfish found inhabiting a wide range of flowing water habitats across the state. Given their restricted dispersal abilities, physiological constraints, and the fragmented nature of their habitat, it is hypothesized that P. spiculifer will exhibit high levels of population structure throughout its range. To test this, the genetic structure of P. spiculifer populations throughout the Oconee River Basin is being investigated by sequence analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Preliminary analysis has revealed little to no population structure within the limited regions of the Lower Oconee sampled to date. However, additional sampling may reveal population structure corresponding to specific barriers (e.g., Wallace and Sinclair Dams) and/or geologic regions (e.g., Piedmont and Coastal Plains). This project has the potential to provide valuable information that can be used for the conservation and management of crayfish and other freshwater species throughout Georgia and the southeastern United States
HIGH-FREQUENCY ACCELEROMETER RECORDING OF KEY PREDATORY BEHAVIORS IN VIPERS: A CASE STUDY WITH TIMBER RATTLESNAKES (CROTALUS HORRIDUS)**
No full textTri-axial accelerometers (ACTs) are becoming increasingly common in studies of animal behavior wherein direct observation of subjects in nature is constrained or impossible. ACTs are small (\u3c 1 g) piezo-electric (spring-like) sensors that measure three-dimensional acceleration (upward, downward, and side-to-side) derived from subject motion. When leveraged with advanced machine learning techniques, these data can enable precise automated classification of a wide range of movement-mediated behaviors. Until recently, ACTs were largely reserved for larger-bodied organisms or those most amenable to the temporary external attachment of devices. Ongoing ACT miniaturization has now expanded the breadth of organisms amenable to these methods. This project aims to expand on a recently developed framework for ACT monitoring in wild-ranging snakes, a group that has been mostly overlooked in biologging applications. We have completed extensive captive ACT validation trials with timber rattlesnakes (Crotalus horridus) and have used these datasets in the training and testing of robust classification models of foraging behaviors, i.e. strike and swallowing of prey items. Using AcceleRater, a free online service available to the community, we trained, tested and compared linear SVM, decision tree, and random forest classification models for strike, movement, and stillness using a window size of 0.4 seconds. Separate linear SVM, decision tree and random forest models were trained, tested, and compared with a window size of three seconds for swallowing behaviors. Following validation of these models, we translated this method to the field with a population of C. horridus in the lower Piedmont of middle Georgia to evaluate the efficacy of externally attached ACTs for remote and continuous monitoring of predatory behaviors by wild-ranging vipers
SYNTHESIS, GELATION, AND STEADY STATE FLUORESCENCE PROPERTIES OF ALKYLOXYCOUMARIN DERIVATIVES **
No full textMolecular gels play an essential role in biomedical applications, such as drug-delivery systems and sensors. Fluorescent molecular gels are reported to have potential applications in sensing since its light-emitting devices. Coumarin is an aromatic organic compound that exhibits fluorescence properties and has been reported to find applications as sensors and in medical imaging. In the present study, a series of four alkylated coumarin derivatives were prepared from 7-hydroxycoumarin and 4-hydroxycoumarin by varying the alkyl chain lengths (n= C10H21, C12H25). The synthesized compounds were characterized using spectroscopic and thermal analysis. The Gelating ability of the synthesized compounds in various polarity liquids as well as the steady-state fluorescence and thermal properties will be presented
OPTIMIZATION OF A BALL\u27S LAUNCH IN SPORTS
No full textNewton\u27s law of motion is used to study the effects of air resistance on an object\u27s motion. In ball-related sports such as baseball, soccer, etc., understanding the effects of air resistance is essential to optimize ball launch performance. This performance optimization can be studied by identifying the minimal time it takes for a ball with speed v to travel a certain distance. We work with two models that apply to an object\u27s motion. In model 1, we make use of a linear air drag force, f=cv, where c, has units of kg/s. In model 2 we make use of a quadratic air drag force, f= γv^2, where γ has units of kg/m. Newton\u27s second law leads to a differential equation, which can be solved to obtain the object\u27s total air time. By differentiating this function, one can identify the minimum time of flight and thus optimize the launch efficiency. The analytic calculations are compared to MATLAB\u27s numerical results
CARABELLI\u27S TRAIT EXPRESSION IN AGILE MANGABEYS (CERCOCEBUS AGILIS), ANGOLAN COLOBUS MONKEYS (COLOBUS ANGOLENSIS) AND OLIVE BABOONS (PAPIO ANUBIS): THE ROLE OF SIZE AND PHYLOGENY
No full textCarabelli’s trait is an extension of the cingulum at the base of the lingual surface of the protocone on the maxillary molars. This trait can range from a small pit to a large cusp with a free apex. Since the expression of Carabelli’s trait is neutral with respect to selection, its presence or absence serves to approximate relatedness. Carabelli’s trait is commonly found in humans, apes and baboons, and understanding its varying expression can aid in reconstructing the diversification of fossil primates during the Miocene, 23-5 million years ago. In addition to phylogeny, tooth size may also influence trait expression with larger molars tending to exhibit morphological traits that are not present in smaller counterparts. To examine the extent to which size and phylogeny influence the expression of Carabelli’s cusp in catarrhine monkeys, we examined three taxa, including agile mangabeys (Cercocebus agilis, n = 45) and Angolan colobus monkeys (Colobus angolensis, n = 24), which are similar in size but distantly related, and olive baboons (Papio anubis, n = 21) which are much larger than the other two but more closely related to mangabeys. Individuals were compared using the Great Ape Dental Scoring System in which Carabelli’s trait is categorized as exhibiting four discrete morphological stages of expression. We anticipated Papio to exhibit the greatest degree of expression of Carabelli’s trait given its larger size and complex dental morphology, followed by Cercocebus due to phylogeny. The results indicate that larger primates (Papio) do indeed present a greater frequency of Carabelli’s trait. Papio often exhibits a larger Carabelli’s trait compared to the other taxa which are restricted to a minimal expression. Cercocebus yields a slightly greater frequency than Colobus. Although its expression is limited, this is likely to be the first reported incidence of Carabelli’s trait in Cercocebus and Colobus
EVALUATING MATCHING AND ODDITY-TO-SAMPLE LEARNING IN HOUSE CRICKETS**
No full textMatching-to-Sample (MTS) and Oddity-to-Sample (OTS) are behavioral tasks often used in research focusing on animal cognition in vertebrate species. These tasks require a subject to perceive a sample stimulus and then direct their attention to two choice stimuli. We began exploring these tasks using House crickets in a Grice box maze that has a start box which widens slightly to allow for two parallel alleys and goal boxes at their ends. We tested crickets using three configurations of the maze and two sets of stimuli. The first configuration was flat on a table using 60 grit and 220 grit sandpaper as our stimuli. We had two out of seven crickets meet criterion on their assigned association. Our second configuration shifted the maze into a 30-degree angle taking advantage of crickets’ tendency toward negative geotaxis and hoping the differences in grit count would be more salient, but only three out of 12 crickets met criterion. Finally, we laid the maze flat and replaced the sandpaper stimuli with Green and Ultraviolet LEDs while again suspecting stimulus saliency may be a factor. This final configuration resulted in four out of eight crickets meeting criterion. A chi-square test comparing the number of crickets that made criterion on each configuration for MTS versus OTS yielded a significant outcome (χ2(2) = 10.96, p \u3c .01) indicating there are differences between subjects due to their treatments. When subjects met criterion, they were switched to the opposite task. Reversals challenged the crickets’ behavioral flexibility. Initial trials typically reflected previous learning and often resulted in the crickets not moving beyond the choice point in the maze while vacillating between the two choices after their early choices were not reinforced. We are continuing our research using LEDs as the stimuli
The Role of Adenovirus Serotype 5 E4 11k in the Relocalization of the Cellular P Body Proteins
Get PDFHuman adenoviruses are a useful tool to understand basic cellular biology in addition to viral infections. Historically, cellular splicing was first discovered in adenovirus, but other cellular processes, such as double-strand break repair and aggresome formation, have been further elucidated through adenoviral infection. The adenovirus protein E4 11k has been shown to disrupt cytoplasmic processing bodies (p bodies), which are not well-understood but are involved in mRNA metabolism. Several p body proteins were found to be reorganized in the cytoplasm with adenovirus serotype 5 (Ad5) able to cause the colocalization of these p body proteins with aggresomes. The p body protein Lsm1 has been found to colocalize with E4 11k in aggresomes, but Edc3 and Pat1b are two p body proteins that have not been as well-studied in adenovirus-infected cells. Cells were treated with cadmium chloride or infected with wild-type and mutant viruses before staining them to visualize the p body proteins and a marker for viral infection by confocal microscopy. We were able to determine that the presence of E4 11k was not necessary for relocalization of either Lsm1 or Edc3 to aggresomes, while Pat1b did not localize to aggresomes under any conditions tested. We wanted to characterize Pat1b relocalization further so we counted the number of Pat1b foci in mock-infected cells and then the virally-infected cells, and were able to determine that Ad5 E4 11k is necessary and sufficient to induce an increase in cytoplasmic Pat1b foci. We also determined that this increase in Pat1b foci appears to be serotype-specific when compared to Ad9 and Ad12 E4 11k protein. The lack of apparent change with Pat1b localization with Ad9 E4 11k expression was a novel finding that suggests there may be something unique about Pat1b and p body localization
Making the Error Bar Overlap Myth a Reality: Comparative Confidence Intervals
Get PDFMany interpret error bars to mean that if they do not overlap the difference is statistically “significant”. This overlap rule is really an overlap myth; the rule does not hold true for any conventional type of error bar. There are rules of thumb for estimating P values, but it would be better to show error bars for which the overlap rule holds true. Here I explain how to calculate comparative confidence intervals which, when plotted as error bars, let us judge significance based on overlap or separation. Others have published on these intervals (the mathematical basis goes back to John Tukey) but here I advertise comparative confidence intervals in the hope that more people use them. Judging statistical “significance” by eye would be most useful when making multiple comparisons, so I show how comparative confidence intervals can be used to illustrate the results of Tukey test. I also explain how to use of comparative confidence intervals to illustrate the effects of multiple independent variables and explore the problems posed by heterogeneity of variance and repeated measures. When families of comparative confidence intervals are plotted around means, I show how box-and-whiskers plots make it easy to judge which intervals overlap with which. Comparative confidence intervals have the potential to be used in a wide variety of circumstances, so I describe an easy way to confirm the intervals’ validity. When sample means are being compared to each other, they should be plotted with error bars that indicate comparative confidence intervals, either along with or instead of conventional error bars
Brown Anole (Anolis sagrei) Hoxa5: Insights into the Divergence of Hoxa5 Gene Expression and Regulation Across Evolutionarily Divergent Gnathostome Vertebrates
Get PDFHox genes are evolutionarily conserved developmental regulatory genes that function, in part, to pattern the anterior-posterior (AP) axis of organs and organ systems during animal embryonic development. Hoxa5, specifically, is shown to be expressed in the spinal cord, somites, or transient compartments giving rise to the vertebrae and ribs, developing gut, lungs, and limbs of the mouse (Mus musculus). The cis-regulatory elements (CREs), or short DNA sequences, that direct Hoxa5 expression in these embryonic domains have been mapped and functionally tested in the mouse as well. Similar Hoxa5 expression patterns have been observed in chicken (Gallus gallus), American alligator (Alligator mississipiensis), and dogfish shark (Scyliorhinus canicular), but have shown divergence in the anterior limit of expression within the somites. Specifically, while mouse expression begins in somite 3, chicken, alligator, and shark begin in 8, 9, and 9, respectively. Further, no hoxa5 expression has been observed in the somites for teleost fish. Here, we present the embryonic Hoxa5 expression pattern within brown anole lizard (Anolis sagrei). Our data shows that Hoxa5 within the lizard has an anterior limit of expression in somite 6 and exhibits a more similar expression pattern to that of mouse, chicken, alligator, and shark than to teleost fishes. Furthermore, our comparative genomic DNA sequence analyses display that the functional CREs mapped in the mouse are conserved among the tetrapods, but not with the shark or teleost fishes. Our analyses suggest that divergent Hoxa5 expression patterns result from divergence within their respective CREs