The Effect of the Visual System and Habitat Light on the Colors of Anolis Lizard Visual Signals

Lizards of the genus Anolis communicate almost exclusively with visual signals that include the extension of a colorful, extensible throat fan called a dewlap. Dewlap color exhibits impressive diversity across anoline species and is thought to have evolved due to two simultaneous sets of selection pressures: (1) selection for high detectability, and (2) selection for a color that is different from the dewlap color of other sympatric species of Anolis in order to facilitate species recognition. In order for a dewlap display to be successful, it must be “detected” by the intended viewer. We hypothesize that a detectable dewlap should be distinct from its natural background in terms of brightness and color. We collected and analyzed spectral data for dewlap color and habitat light conditions for four species of anoles inhabiting the island of Puerto Rico. Background and dewlap colors were plotted in a three-dimensional tetrahedral perceptual color space based on the relative stimulation of each of the four types of cone photoreceptors of the anoline visual system. We found that for each species, dewlap colors were distinct from the range of background colors. We also found that for three out of the four species, dewlaps were typically brighter than the background patches of their habitats. We carried out an additional behavioral experiment testing the likeliness of an anoline visual response being elicited as a function of the difference in brightness between a stimulus and a complex background. Our data suggest that the more a dewlap differs in brightness from the brightness patches in its background, the greater its visibility. Results from both experiments support the hypothesis that natural selection for high detectability in a complex environment has played a major role in the evolution of anoline lizard visual signal color

For What It's Worth: Reward Value Drives Visual Selective Attention

Theeuwes, J.L. [Promotor

The role of Virus "X" (Tortoise Picornavirus) in kidney disease and shell weakness syndrome in European tortoise species determined by experimental infection

Tortoise Picornavirus (ToPV) commonly known as Virus "X" was recently discovered in juvenile European tortoises suffering from soft carapace and plastron as well as kidney disease. Therefore, this virus was a potential candidate to be a causative agent for these disease patterns. Spur thighed tortoises (Testudo graeca) seemed to be more susceptible to establish clinical symptoms than other European species like T. hermanni. Thus this trial investigated the role of ToPV in the described syndrome. Two groups of juvenile European tortoises (T. graeca and T.hermanni) each of 10 animals, were cloacally, oronasally and intracoelomically inoculated with an infectious dose (~ 2000 TICD) of a ToPV strain isolated from a diseased T. graeca. A control group of two animals of each species received non-infected cell culture supernatant. The tortoises were examined daily and pharyngeal and cloacal swabs for detection of ToPV-RNA by RT-PCR were taken from each animal every six days for a period of 6 months. At the end of the study the remaining animals were euthanised and dissected. Bacteriological and parasitological tests were performed and organ samples of all tortoises were investigated by RT-PCR for the presence of ToPV and histopathology. Animals that were euthanised at the end of the experiment, were examined for presence of specific anti-ToPV antibodies. Several animals in both inoculated groups showed retarded growth and a light shell weakness, in comparison to the control animals. Three animals were euthanised during the trial, showing reduced weight gain, retarded growth, severe shell weakness and apathy, in parallel to clinical observations in naturally infected animals. In all inoculated animals of both species an intermittent virus shedding, starting from 18 days post inoculation (d.p.i.), till 164 d.p.i. was detected, while the control animals remained negative. The virus was successfully reisolated in terrapene heart cell culture in 16 of 20 inoculated animals of both species. Histopathology of most inoculated animals revealed a lack of bone remodeling and vacuolisation in kidney tubuli which supports the described pathogenesis of nephropathy and osteodystrophy. Anti- ToPV antibody titres ranged from 1:2 to >1:256 in 13 of 20 animals, whereas all control animals were seronegative. The study proofed the Henle Koch`s postulates of ToPV as causative agent for shell dystrophy and kidney disease in both testudo species. The proposed species specific sensitivity towards clinical disease was not observed

Microbial Resuspension in the Built Environment: The Role of Flooring Materials and Anthropogenic Traffic on Taxonomic Diversity

The interplay between humans and built environments is a new frontier for microbial ecology. Approximately 90% of human activities occur indoors, and current estimates for microorganism diversity in buildings are in the trillions. Previous studies have investigated microbial resuspension (i.e., the surface to air release of biotic and abiotic particulate matter) via temporal analysis of human occupancy patterns and spatial analysis of different flooring materials. However, prior research has not sufficiently addressed flooring structure, human-mediated resuspension in unconstrained environments, and phylogenetic analysis within the context of a single study. Our investigation examined the effect of surface composition and human traffic intensity on the taxonomic composition of airborne microbial communities. In a college academic building, 24 air samples were collected over carpeting during high (n=6) and low (n=6) human activity periods and over linoleum during high (n=6) and low (n=6) activity. DNA was extracted, amplified using prokaryotic 16S primers, sequenced using the Illumina MiSeq platform, and analyzed with the Quantitative Insights into Microbial Ecology statistical package. Prior to merging reads and quality filtering, 227 sequences were yielded across 14 samples and one control. Alpha (within sample) diversity indices of genera richness and evenness were reported along with beta diversity (between sample) comparisons of sequence counts and shared genera across sampling conditions. While low sequence yields precluded the determination of the explanatory power for the activity and flooring variables, the present study’s limitations and new directions for investigating the composition of indoor microbial communities were discussed. With methodological revisions, we anticipate that future studies will help to elucidate the role of building design in modulating microbial resuspension dynamics induced by human traffic patterns between indoor and outdoor environments

A Spatial Analysis of Southern Gubernatorial Elections: 1965-1997

For nearly a century the Democratic Party exerted an unmatched influence at all levels of government in the southern United States. This is particularly true in the eleven former Confederate states: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia. In turn, the policies and personalities of politicians and voters in the South played immense roles in shaping the national Democratic Party and national policies. This paper illustrates the dynamics of political change in the South at the gubernatorial level, and quantifies the magnitude of change over time with statistical analysis

Commutative, idempotent groupoids and the constraint satisfaction problem

A restatement of the Algebraic Dichotomy Conjecture, due to Marti and McKenzie, postulates that if a finite algebra possesses a weak near-unanimity term, then the corresponding constraint satisfaction problem is tractable. A binary operation is weak near-unanimity if and only if it is both commutative and idempotent. Thus if the dichotomy conjecture is true, any finite commutative, idempotent groupoid (CI-groupoid) will be tractable. It is known that every semilattice (associative CI-groupoid) is tractable. A groupoid identity is of Bol-Moufang type if the same three variables appear on either side, one of the variables is repeated, the remaining two variables appear once, and the variables appear in the same order on either side (for example, x(x(yz))=(x(xy))z). These identities can be thought of as generalizations of associativity. We show that there are exactly 8 varieties of CI-groupoids defined by a single additional identity of Bol-Moufang type, derive some of their important structural properties, and use that structure theory to show that 7 of the varieties are tractable. We also characterize the finite members of the variety of CI-groupoids satisfying the self-distributive law x(yz)=(xy)(xz), and show that they are tractable. Varieties of CI-groupoids satisfying other identities strictly weaker than associativity are also considered, and shown to be tractable

The Effects of Integrating Lego Robotics Into a Mathematics Curriculum to Promote the Development of Proportional Reasoning

This mixed methods, action research case study sought to investigate the effects of incorporating LEGO robotics into a seventh-grade mathematics curriculum focused on the development of proportional reasoning through the lens of Social Constructivist Theory. Quantitative data was collected via a pre- and post-test from the mathematics class of six students. Qualitative data was collected from each of the students as they worked in groups of two to complete purposefully designed investigations and activities, from whole class discussions, and student artifacts. The quantitative analysis showed development of proportional reasoning skills with the greatest increase being from low-performing students. The qualitative analysis supports the inclusion of robotics as an avenue to promote student engagement and discussion as the students develop proportional reasoning skills. Overall, the inclusion of robotics was productive for learning; however, future studies should be completed, on larger student populations, as a means to validate the quantitative findings and continue to improve the curriculum via action research

Integrating LEGO Robotics Into a 5th Grade Cross Curricular Unit to Promote the Development of Narrative Writing Skills

This paper describes a unit designed to promote the development of narrative writing skills among 5th grade students through the use of LEGO robotics. Over the course of four, two and one-half hour sessions (one day per week for four consecutive weeks), the students learned how to construct and program robots, write and present a proposal to complete a mission, and connected the learning to their personal experiences with Hurricane Irma. The students began the activity with prior knowledge of World War II and Hiroshima. After learning the basics of building and programming robots, they were presented with a scenario similar to the impact of the bomb drop in Hiroshima – a city in ruins with survivors in need of supplies. Students took the role of engineers to work in pairs to create a proposal, which stated the problem and defined, and justified, a solution to pick up, and deliver, supplies through a specially-designed course using their robots. After the proposals were presented, and accepted, students programmed their robots according to their proposed solution; the activity required students to apply mathematical skills to measure distances in order to traverse parts of the course. Writing reflections were collected to determine individual student understanding and to include an additional element of writing. A final culminating activity required the students to write a narrative piece to relate the events of Hiroshima to their personal experiences with Hurricane Irma

The Effects of Integrating LEGO Robotics into a Mathematics Curriculum to Promote the Development of Proportional Reasoning

A mixed methods, action research case study was conducted to investigate the effects of incorporating LEGO robotics into a seventh-grade mathematics curriculum focused on the development of proportional reasoning through the lens of Social Constructivist Theory. This study applied students’ prior knowledge of the distance, rate, and time formula as they used LEGO EV3 robots to calculate the rate of a robot. The information gained was applied to different iterations, and structures, of the formula to support the development of proportional reasoning skills. The purposefully designed lessons were integral to the development of the students’ understanding of the proportionality existing among the variables. The quantitative analysis reflects the acquisition of understanding of proportional relationships with the greatest increase being from low-performing students. The qualitative analysis provides an in-depth look at how students used their understanding of the distance, rate, and time relationship to develop proportional reasoning skills. Overall, the inclusion of robotics was productive for learning; however, future studies should be completed, on larger student populations, as a means to validate the quantitative findings and continue to improve the curriculum