Adventures in Time and Space: What Shapes Behavioural Decisions in Drosophila melanogaster?

Variation in behaviour can be observed both between individuals, based on their condition and experience as well as between populations due to sources of heterogeneity in the environment. These behavioural differences have evolved as a result of natural and sexual selection where different strategies may be favoured depending on the costs and benefits associated with those behaviours. In this thesis I examine two sources of heterogeneity within the environment and their behavioural consequences: how spatial complexity mediates sexual selection over time, and how inter and intraspecific signals and individual condition influence social oviposition behaviour. By increasing spatial complexity, we were able to manipulate male-female interaction rate which in turn influenced courtship behaviour and male-induced harm, the consequence of this was an increase in female fecundity especially in the later days of the assay and no change in offspring fitness. These results supported the idea that spatial complexity is able to mediate sexual selection through decreased harm to females. Oviposition decisions are of high consequence to an individual’s fitness and can be shaped by many environmental conditions. Instead of expending energy to evaluate all their different costs and benefits of the conditions of potential oviposition sites females can chose to rely on the signals left by others, in this case it would be beneficial for females to identify signals most like themselves. While we found females oviposited with individuals of the same species and diet, when given the option they showed more interest in and laid more eggs on media that previously held virgin males, bringing into question many assumptions of copying behaviour. In Drosophila melanogaster the only control females have over their offspring is who they mate with and where they oviposit their eggs, thus, these two factors can have a long-lasting impact on individual fitness for future generations. It is also important to consider how the standard lab environment may be shaping these behaviours, and the consequences this has for the evolutionary trajectory of lab populations

Behavioral Ecology of an Invasive Species: Habitat and Mate Preference(s) in Drosophila Suzukii

The invasive Spotted-Wing fruit fly, Drosophila suzukii, has inflicted substantial economic losses to the soft-fruit agriculture industry worldwide due to the ability of females in this species to use a large, serrated ovipositor to cut the fruit’s skin and lay eggs directly into the mesocarp of ripening fruit. Once the eggs hatch, larvae consume the fruit flesh, ultimately leaving the fruit unmarketable. This species parasitizes numerous commercial fruit types (including blueberries, blackberries, strawberries, raspberries and occasionally grapes) as well as fruits from a variety of wild plant species. Since fruit types vary in their nutritional composition, as well as their spatial and temporal availability, this suggests that D. suzukii experiences considerable environmental heterogeneity. The environment can have a large influence on the development and evolution of morphological, physiological, and behavioural phenotypes and, thus, can have significant implications for individual variation and population growth and change over time. Thus to better understand success if this invasive species we have examined the behavioural and developmental and reproductive performance of D. suzukii as it relates to their local environment. Specifically we focused on the role of the nutritional developmental history (NDH), which can either hinder or support offspring growth and survival, and may be an important factor when selecting habitats. Secondly, as the juvenile NDH has the potential to greatly influence adult phenotypes, and consequently individual reproductive potential, we also examined if NDH influenced the operation of sexual selection. Here we report evidence that NDH is an important factor for D. suzukii females when choosing oviposition sites, and can have dramatic consequences for offspring development, mate-choice, offspring fitness, and ultimately population growth. Information on these two subject areas (habitat and mate choice) is of great potential importance to bettering future management strategies (e.g. by manipulating fly numbers based on host preference and reproductive strategies), which are currently limited by lack of knowledge on the biology of this species

Impact of Environmental Factors on the Profit Efficiency of Rice Production: A Study in Vietnams Red River Delta

Environmental factors affect agriculture production productivity and efficiency in which result in a change of profit efficiency This paper seeks to estimate the impacts of environmental factors on the profitability of rice farmers in the Red River Delta of Vietnam The dataset was compiled from personal interviews in 349 farmers Both OLS and MLE translog profit functions were used in this study Five production inputs and four environmental factors were included in those functions The estimation of the stochastic profit frontier with a two-stage approach was used to measure profitability The results showed that the profit efficiency was about 75 on average and various environmental factors influence profit efficiency significantly as well as beside farm specific characteristics Plant disease soil fertility irrigation and water pollution were the four environmental factors that caused profit loss in rice production The results of the study indicated that farmers should reduce household size and the quantity of farm plots apply a row seeding technique and improve environmental factors to obtain high profit efficiency Special consideration should be given to irrigation infrastructure and water quality improvemen

Screening for antibiotic-producers in soil from a garden

Multidrug-resistant pathogens are the leading cause of nosocomial infection, which killed more than 30,000 people in the United States every year. Among these, ESKAPE strains bugs, which comprise six highly drug-resistant bacteria, pose the greatest challenge to the healthcare system. In order to fight the antibiotic-resistant crises, novel antibiotic-producers must be discovered. This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student sourcing antibiotic discovery from the soil. Pseudomonas was revealed to produce a zone of inhibition against Bacillus subtilis on LB media. The next step will be isolating the active antibiotic compounds and studying their mode of action

Adventures in Time and Space: What Shapes Behavioural Decisions in Drosophila melanogaster?

Variation in behaviour can be observed both between individuals, based on their condition and experience as well as between populations due to sources of heterogeneity in the environment. These behavioural differences have evolved as a result of natural and sexual selection where different strategies may be favoured depending on the costs and benefits associated with those behaviours. In this thesis I examine two sources of heterogeneity within the environment and their behavioural consequences: how spatial complexity mediates sexual selection over time, and how inter and intraspecific signals and individual condition influence social oviposition behaviour. By increasing spatial complexity, we were able to manipulate male-female interaction rate which in turn influenced courtship behaviour and male-induced harm, the consequence of this was an increase in female fecundity especially in the later days of the assay and no change in offspring fitness. These results supported the idea that spatial complexity is able to mediate sexual selection through decreased harm to females. Oviposition decisions are of high consequence to an individual’s fitness and can be shaped by many environmental conditions. Instead of expending energy to evaluate all their different costs and benefits of the conditions of potential oviposition sites females can chose to rely on the signals left by others, in this case it would be beneficial for females to identify signals most like themselves. While we found females oviposited with individuals of the same species and diet, when given the option they showed more interest in and laid more eggs on media that previously held virgin males, bringing into question many assumptions of copying behaviour. In Drosophila melanogaster the only control females have over their offspring is who they mate with and where they oviposit their eggs, thus, these two factors can have a long-lasting impact on individual fitness for future generations. It is also important to consider how the standard lab environment may be shaping these behaviours, and the consequences this has for the evolutionary trajectory of lab populations

Pulsed Chronopotentiometry with Polymer-Based Potassium-Selective Electrodes

This research aimed to develop ion-selective electrodes selective to potassium for use in measuring potassium concentration in blood. Potassium is an important electrolyte within the body, orchestrating nerve excitation, muscular function, and heart rate. Excessive or insufficient potassium levels can cause breakdowns in these systems difficult to differentiate from other potential causes. Isolating potassium concentration as the sole cause necessitates selective measurement. Pulsed Chronopotentiometry with polymer-based membrane electrodes offered a versatile route of interrogation: membrane composition and magnitude of applied current can be altered to assess selectivity in a fast and controlled manner. All potential measurements recorded corresponded to known concentrations of potassium. Known concentrations were first used to construct calibration curves, then to explore depletion of ions at the membrane surface. The latter offers a method of measurement not requiring calibration. Both methods saw success when measuring potassium alone, while depletion proved difficult in presence of sodium

Institutional Barriers to Black and Latino Male Collegians’ Success in Engineering and Related STEM Fields

Diverse people and perspectives are needed to spur innovation and tackle societal problems. A wealth of untapped intellectual and economic potential exists among historically underrepresented racial/ethnic groups – including Blacks and Latinos – who have not had equitable access to engineering and related STEM fields. For Blacks and Latinos who are accepted into engineering and related STEM fields, they face a number of barriers to their success which lead to low retention and graduation rates. In historically male-dominated fields such as engineering and related STEM disciplines, Black and Latino men have remained underrepresented at the student and faculty ranks. To uncover and tackle the “institutional barriers” that men of color face, nearly 50 interviews with Black and Latino collegians were analyzed to better understand the mechanisms that prevent them from maximizing their potential for success in engineering and related STEM fields. Interviews revealed that students must overcome institutional obstacles such as: (a) inadequate academic advising, (b) poor quality teaching, (c) limited course offerings, and (d) insufficient financial aid. This paper includes recommendations that are helpful to faculty, staff and administrators who are interested in increasing the number of Black and Latino male graduates in engineering and related STEM fields

Peirce Long Correspondence

Entries include typed letters, a biography written by Long\u27s relative, and a publisher advertisement with a photographic image of Long

Infographic: Career Readiness Challenge (CRC) Summary

This infographic summarizes the final report from a study titled, Gamified Online Platform to Support Student-Athlete Career Readiness, funded by the NCAA Innovations in Research and Practice Grant Program. The purpose of the study was to create a gamified online career readiness program to enhance attitudes towards career planning and support the translation of professional competencies. Over a span of seven weeks, 116 student-athletes from Embry-Riddle Aeronautical University (ERAU) - Daytona Beach participated in the study. The student-athletes competed in three different sports. Among ERAU student-athletes, the highest contribution of professional competencies involved: a) leadership, b) communication and c) collaboration. The final report and slides are publicly available via http://www.ncaa.org/about/resources/research/career-readiness-challeng

Various Differents for 0-Dimensional Schemes and Applications

This thesis attempts to investigate the Noether, Dedekind, and Kähler differents for a 0-dimensional scheme X in the projective n-space P^n_K over an arbitrary field K. In particular, we focus on studying the relations between the algebraic structure of these differents and geometric properties of the scheme X. In Chapter 1 we give an outline to the problems this thesis is concerned with, a brief literature review for each problem, and the main results regarding these problems. Chapter 2 contains background results that we will need in the subsequent chapters. We introduce the concept of maximal p_j-subschemes of a 0-dimensional scheme X and give some descriptions of them and their Hilbert functions. Furthermore, we generalize the notion of a separator of a subscheme of X of degree deg(X)-1 to a set of separators of a maximal p_j-subscheme of X. In Chapter 3 we explore the Noether, Dedekind, and Kähler differents for 0-dimensional schemes X. First we define these differents for X, and take a look at how to compute these differents and examine their relations. Then we give an answer to the question "What are the Hilbert functions of these differents?" in some cases. In Chapter 4 we use the differents to investigate the Cayley-Bacharach property of 0-dimensional schemes over an arbitrary field K. The principal results of this chapter are characterizations of CB-schemes and of arithmetically Gorenstein schemes in terms of their Dedekind differents and a criterion for a 0-dimensional smooth scheme to be a complete intersection. We also generalize some results such as Dedekind's formula and the characterization of the Cayley-Bacharach property by using Liaison theory. In addition, several propositions on the uniformities are proven. In Chapter 5 we are interested in studying the Noether, Dedekind, and Kähler differents for finite special classes of schemes and finding out some applications of these differents. First, we investigate these differents for reduced 0-dimensional almost complete intersections X in P^n_K over a perfect field K. Then we investigate the relationships between these differents and the i-th Fitting ideals of the module of Kähler differentials of the homogeneous coordinate ring of X. Finally, we look more closely at the Hilbert functions and the regularity indices of these differents for fat point schemes