Antipredator behavior and cue recognition by multiple Everglades prey to a novel cichlid predator

Novel predator introductions are thought to have a high impact on native prey, especially in freshwater systems. Prey may fail to recognize predators as a threat, or show inappropriate or ineffective responses. The ability of prey to recognize and respond appropriately to novel predators may depend on the prey’s use of general or specific cues to detect predation threats.We used laboratory experiments to examine the ability of three native Everglades prey species (Eastern mosquitofish, flagfish and riverine grass shrimp) to respond to the presence, as well as to the chemical and visual cues of a native predator (warmouth) and a recentlyintroduced non-native predator (African jewelfish). We used prey from populations that had not previously encountered jewelfish. Despite this novelty, the native warmouth and nonnative jewelfish had overall similar predatory effects, except on mosquitofish, which suffered higher warmouth predation. When predators were present, the three prey taxa showed consistent and strong responses to the non-native jewelfish, which were similar in magnitude to the responses exhibited to the native warmouth. When cues were presented, fish prey responded largely to chemical cues, while shrimp showed no response to either chemical or visual cues. Overall, responses by mosquitofish and flagfish to chemical cues indicated low differentiation among cue types, with similar responses to general and specific cues. The fact that antipredator behaviours were similar toward native and non-native predators suggests that the susceptibility to a novel fish predator may be similar to that of native fishes, and prey may overcome predator novelty, at least when predators are confamilial to other common and longer-established non-native threats.

Understanding the role of Dimethylsulfoniopropionate as a potential chemotactic cue for coral-associated bacteria

Most reef-building corals are known to engage in non-pathogenic symbiosis not only with unicellular dinoflagellates from the genus Symbiodinium, but also with other microscopic organisms such as bacteria, fungi, and viruses. The functional details of these highly complex associations remain largely unclear. The impetus of this study is to gain a better understanding of the symbiotic interaction between marine bacteria and their coral host. Studies have shown that certain bacterial orders associate with specific certain coral species, thus making the symbiotic synergy a non-random consortium. Consequently both corals and bacteria may be capable of emitting chemical cues that enable both parties to find one another and thus generate the symbiosis. The production of these cues by the symbionts may be the result of environmental stimuli such as elevated ocean temperatures, increased water acidity, and even predation. One potential chemical cue could be the compound DMSP (Dimethylsulfoniopropionate) and its sulphur derivatives. Reef-building corals are believed to be the major producers of the DMSP during times of stress. Marine bacteria utilize DMSP as a source of sulfur and carbon. As a result corals could potentially attract their bacterial consortium depending on their DMSP production. This would enable them to adapt to fluctuating environmental conditions by changing their bacterial communities to that which may aid in survival. To test the hypothesis that coral-produced DMSP plays a role in attracting symbiotic bacteria, this study utilized the advent of high-throughput sequencing paired with chemotactic assays to determine the response of coral-associated bacterial isolates towards the DMSP compound at differing concentrations. Chemotaxis assays revealed that some isolates responded positively towards the DMSP compound. This finding adds to existing evidence suggesting that coral-associated pathogens utilize chemotaxis as a host colonization and detection mechanism. Thus the symbiotic bacteria that make up the coral microbiome may also employ this process. Furthermore this study demonstrates that bacterial motility may be a strong contributing factor in the response to the chemotactic cue. Swarming motility may be better suited for bacteria that need to respond to a chemical gradient on the surface of the coral. Therefore the isolates that were able to swarm seemed to respond more strongly to the DMSP.

Understanding the role of Dimethylsulfoniopropionate as a Potential Chemotactic Cue for Coral-Associated Bacteria

Most reef-building corals are known to engage in symbiosis not only with unicellular dinoflagellates from the genus, Symbiodinium, but they also sustain highly complex symbiotic associations with other microscopic organisms such as bacteria, fungi, and viruses. The details of these non-pathogenic interactions remain largely unclear. The impetus of this study is to gain a better understanding of the symbiotic interaction between marine bacteria and a variety of coral species representative of differing morphologies. Studies have shown that certain bacterial orders associate specifically with certain coral species, thus making the symbiotic synergy a non-random consortium. Consequently both corals and bacteria may be capable of emitting chemical cues that enables both parties to find one another and thus creating the symbiosis. One potential chemical cue could be the compound DMSP (Dimethylsulfoniopropionate) and its sulphur derivatives. Reef-building corals are believed to be the major producers of the DMSP and its derivatives during times of stress. As a result corals could potentially attract their bacterial consortium depending on their DMSP production. Corals may be able to adapt to fluctuating environmental conditions by changing their bacterial communities to that which may aid in survival. The cause of this attraction may stem from the capability of a variety of marine bacteria to catabolize DMSP into different metabolically significant pathways, which may be necessary for the survival of these mutualistic interactions. To test the hypothesis that coral-produced DMSP play a role in attracting symbiotic bacteria, this study utilized the advent of high-through sequencing paired with bacterial isolation techniques to properly characterize the microbial community in the stony coral Porites astreoides. We conducted DMSP swarming and chemotaxis assays to determine the response of these coral-associated bacterial isolates towards the DMSP compound at differing concentrations. Preliminary data from this study suggests that six out of the ten bacterial isolates are capable of conducting unidirectional motility; these six isolates are also capable of conducting swarming motility in the direction of an increasing DMSP concentration gradient. This would indicate that there is a form of positive chemotaxis on behalf of the bacteria towards the DMSP compound. By obtaining a better understanding of the dynamics that drive the associations between bacterial communities and corals, we can further aid in the protection and conservation processes for corals. Also this study would further elucidate the significance of the DMSP compound in the survival of corals under times of stress.

Understanding the role of Dimethylsulfoniopropionate as a Potential Chemotactic Cue for Coral-Associated Bacteria

Most reef-building corals are known to engage in symbiosis not only with unicellular dinoflagellates from the genus, Symbiodinium, but they also sustain highly complex symbiotic associations with other microscopic organisms such as bacteria, fungi, and viruses. The details of these non-pathogenic interactions remain largely unclear. The impetus of this study is to gain a better understanding of the symbiotic interaction between marine bacteria and a variety of coral species representative of differing morphologies. Studies have shown that certain bacterial orders associate specifically with certain coral species, thus making the symbiotic synergy a non-random consortium. Consequently both corals and bacteria may be capable of emitting chemical cues that enables both parties to find one another and thus creating the symbiosis. One potential chemical cue could be the compound DMSP (Dimethylsulfoniopropionate) and its sulphur derivatives. Reef-building corals are believed to be the major producers of the DMSP and its derivatives during times of stress. As a result corals could potentially attract their bacterial consortium depending on their DMSP production. Corals may be able to adapt to fluctuating environmental conditions by changing their bacterial communities to that which may aid in survival. The cause of this attraction may stem from the capability of a variety of marine bacteria to catabolize DMSP into different metabolically significant pathways, which may be necessary for the survival of these mutualistic interactions. To test the hypothesis that coral-produced DMSP play a role in attracting symbiotic bacteria, this study utilized the advent of high-through sequencing paired with bacterial isolation techniques to properly characterize the microbial community in the stony coral Porites astreoides. We conducted DMSP swarming and chemotaxis assays to determine the response of these coral-associated bacterial isolates towards the DMSP compound at differing concentrations. Preliminary data from this study suggests that six out of the ten bacterial isolates are capable of conducting unidirectional motility; these six isolates are also capable of conducting swarming motility in the direction of an increasing DMSP concentration gradient. This would indicate that there is a form of positive chemotaxis on behalf of the bacteria towards the DMSP compound. By obtaining a better understanding of the dynamics that drive the associations between bacterial communities and corals, we can further aid in the protection and conservation processes for corals. Also this study would further elucidate the significance of the DMSP compound in the survival of corals under times of stress.

Parental behaviors in child anxiety: An observational study

The increasing awareness of the prevalence, impairment, and long-term consequences of childhood anxiety disorders have led investigators to explore psychosocial factors in the etiology of these disorders. Recent investigations have begun to focus on family-level processes in the etiology and/or maintenance of childhood anxiety disorders, specifically patterns of parent-child interaction. The present study compared parent-child interactions across three problem-solving tasks of clinically anxious children and their mothers versus non-referred children and their mothers in terms of (1) direct observation measures, (2) children's, mothers', and independent observer's subjective ratings, (3) and children's evaluations using videotape-aided thought reconstruction. ^ Results suggested that the mothers of clinically anxious children engaged in fewer positive and more negative parenting strategies as compared to the mothers of non-referred children across three tasks. Although not significant, trends were evident among the subjective ratings reported by the clinically anxious children, mothers, and observer for the global perception indices. When videotape-aided thought reconstruction was used as a cue to elicit children's perceptions of the parent-child interactions, clinically anxious children reported less mother-referent positive statements and more mother-referent negative statements than non-referred children. ^

How source credibility and message claims interact in determining advertising effectiveness

Credible endorsers are often used in advertisements. However, there is conflicting evidence on the role source credibility plays in persuasion. Early research found that source credibility affects persuasion when subjects pay attention to the communication. Other research indicates that a credible source enhances persuasion when people do not scrutinize the message claims carefully and thoroughly. This effect is opposite to what was indicated by early research. More recent research indicates that source credibility may affect persuasion when people scrutinize the message claims, but limits this effect to advertisements with certain type of claims (i.e., ambiguous or extreme claims). This dissertation proposes that source credibility might play a broader role during persuasion than suggested by the empirical literature. Source credibility may affect persuasion, at low levels of involvement, by serving as a peripheral cue. It may also affect persuasion, at high involvement, by serving as an argument or biasing elaboration. ^ Each of these possibilities was explored in an experiment using a 3 (source credibility) x 2 (type of claim) x 2 (levels of involvement) full factorial design. The sample consisted of 180 undergraduate students from a major southeastern University. ^ Results indicated that, at high levels of involvement, the credibility of the source affected persuasion. This effect was due to source credibility acting as an argument within the advertisement. This study did not find that source credibility affected persuasion by biasing elaboration, at high involvement, or by serving as a peripheral cue, at low involvement. ^

Ecfrasis: Escritura y pintura en el costumbrismo argentino

This dissertation examines the discursive practice of Argentine costumbrista texts from a novel perspective. In (re)reading the works of selected prominent writers from the late colonial period to the end of the Nineteenth Century, including those of Alonso Carrió de la Vandera, Emeric Essex Vidal, León Pallière, Lucio Vicente López, Lucio V. Mansilla, and Pastor Obligado we focus on the presence of ekphrastic enunciations with a view toward linking the plastic, painterly dimensions of the prose to parallel representations by artists of the same period. Thus the costumbristas are studied in tandem with the watercolors, oil paintings and lithographic compositions of artists such as Carlos Enrique Pellegrim, César Hipólito Bacle, Raymond Monvoisin and Hipólito Moulin. The resulting comparative study of the two arts---the verbal and the pictorial---illustrates the notion described by W. J. T. Mitchell that a literary text may well "represent a work of visual or graphic art." And thus, it provides us with visual, spatial motifs that enhance its powers of representation. ^ In developing our focus on ekphrastic representations we have followed the theoretic studies of Murray Krieger, Jean H. Hagstrum, James Hefferman, John Hollander, W. J. T. Mitchell, Johann Gottfried Herder, and Wendy Steiner among others, all of whom in various ways take their cue from Horace's Ut pictura poesis and the notion that poetry, that is literary discourse, can be likened to a panting and that in both arts there is a refractive quality that makes literature a spoken vehicle of expression and painting a silent, complementary voice. ^ In studying the literary and plastic discourses comparatively what becomes evident is that they share cultural and ideological concerns that center around the notion of self-definition, national identity, and the relation of the individual to the incipient national community (Benedict Anderson). These concerns are highlighted via the depiction of customs, mores, dress, work habits, professions, and social classes. In late colonial literature and painting and especially in the Nineteenth Century, which constitutes the defining period of Argentine political independence, the confluence of the two disciplinary discourses addresses, and underscores the issues of socio-political empowerment in the new Argentine nation. ^

The interactive effects of predators, resources, and disturbance on freshwater snail populations from the Everglades

The origins of population dynamics depend on interplay between abiotic and biotic factors; the relative importance of each changing across space and time. Predation is a central feature of ecological communities that removes individuals (consumption) and alters prey traits (non-consumptive). Resource quality mitigates non-consumptive predator effects by stimulating growth and reproduction. Disturbance resets predator-prey interactions by removing both. I integrate experiments, time-series analysis, and performance trials to examine the relative importance of these on the population dynamics of a snail species by studying a variety of their traits. A review of ninety-three published articles revealed that snail abundance was much less in the Everglades and similar ecosystems compared to all other freshwater ecosystems considered. Separating consumptive from non-consumptive (cues) predator effects at different phosphorous levels with an experiment determined that phosphorous stimulated, but predator cues inhibited snail growth (34% vs. 23%), activity (38% vs. 53%), and reproductive effort (99% vs. 90%) compared to controls. Cues induced taller shells and smaller openings and moved to refugia where they reduced periphyton by 8%. Consumptive predator effects were minor in comparison. In a reciprocal transplant cage experiment along a predator cue and phosphorous gradient created by a canal, snails grew 10% faster and produced 37% more eggs far from the canal (fewer cues) when fed phosphorous-enriched periphyton from near the canal. Time-series analysis at four sites and predator performance trials reveal that phosphorous-enriched regions support larger snail populations, seasonal drying removes snails at all sites, crayfish negatively affect populations in enriched regions, and molluscivorous fish consume snails in the wet season. Combining these studies reveals interplay between resources, predators, and seasonality that limit snail populations in the Everglades and lead to their low abundance compared to other freshwater ecosystems. Resource quality is emerging as the critical factor because improving resources profoundly improved growth and reproduction; seasonal drying and predation become important at times and places. This work contributes to the general understanding in ecology of the relative importance of different factors that structure populations and provides evidence that bolsters monitoring efforts to assess the Comprehensive Everglades Restoration Plan that show phosphorous enrichment is a major driver of ecosystem change.

A model of mistaken alibis: How innocent alibi providers generate inaccurate alibis

This dissertation comprised two experiments, which addressed three main goals: (a) to test a new paradigm for measuring objectively the accuracy of alibis, (b) to explore the effectiveness of three retrieval cues (time only, location only, and time-and-location) in an alibi context, and (c) to explore the metacognitive strategies of innocent alibi providers who experience different financial incentives as well as different motivations for reporting (be informative vs. be convincing). ^ The novel paradigm appears promising: by surreptitiously controlling the whereabouts of future alibi providers during a critical time, objective accuracy measurements were in fact possible. Such accuracy measurements revealed that time-cued retrieval can be devastating to innocent alibi providers. Participants who attempted to recall their whereabouts via a time cue were significantly less accurate than participants who attempted recall via a location cue (Experiment 1). ^ Innocent alibi providers, when cued effectively, may not, however, report their memories differently from memory reporters in non-alibi contexts. When cued effectively, participants who experienced a goal of being convincing did not differ in accuracy from participants who experienced a goal of merely being informative (Experiment 2). Similarly, participants did not differ from one another in accuracy across different levels of financial incentive (Experiment 2). ^ Despite the indistinguishable accuracy rates of alibi providers and non-alibi memory reporters when retrieval was cued effectively, proffering mistaken alibis presents a real risk for innocent suspects. Future research needs to address methods by which that risk can be reduced. ^

The differential effects of *American and British trial proceedings on juror decision-making

Seven basic elements differentiate British from American trial procedures: confining attorneys to their tables; dealing with objections outside the presence of the jury; resolving disagreements between attorneys prior to objections being made; presenting the defense opening statement at the close of the prosecution case; the judge directly questions witnesses and has a wider latitude in controlling the evidence; and the judge gives a summation of all the evidence presented to the jury (Fulero & Turner, 1997). The present experiment examined the influence of these different courtroom procedures, judges' non-verbal behavior, and evidence strength on juror decision-making. Using models of persuasion to understand how the varying elements may effect juror decision-making, it was predicted that trials following American courtroom procedures would be more distracting for jurors and as such, they would be more likely to rely on the peripheral cue of the judge's expectations for trial outcome as expressed in his nonverbal behavior. In trials following British procedures jurors should be less distracted and better able to scrutinize the strength of the evidence that in turn should minimize the influence of the judge's nonverbal behavior. Two hundred forty-five participants viewed a mock civil trial in which courtroom procedure, judge's nonverbal behavior, and evidence strength were varied. Analyses suggest that courtroom procedure and evidence strength influenced the direction of participants' verdicts, but that judge's nonverbal behavior did not have a direct impact on verdict preference. Judge's nonverbal behavior appeared to influence other measures related to verdict. Participants were more confident in their verdicts when they agreed with judge's nonverbal behavior and when they viewed British courtroom procedures. Participants were more likely to return estimates of the defendant's liability that reflected judge's nonverbal behavior and a congruency with evidence strength. Participants also recalled more facts in the British conditions than in the American conditions. These findings are interpreted as indicating the importance of the impact of trial procedures and of nonverbal influence. ^

Two -way direction of influence in mother-infant interaction as denoted by concurrent reciprocal learning processes

This series of 5 single-subject studies used the operant conditioning paradigm to investigate, within the two-way influence process, how (a) contingent infant attention can reinforce maternal verbal behaviors during a period of mother-infant interaction and under subsequent experimental manipulation. Differential reinforcement was used to determine if it is possible that an infant attending to the mother (denoted by head-turns towards the image of the mother plus eye contact) increases (reinforces) the mother's verbal response (to a cue from the infant) upon which the infant behavior is contingent. There was also (b) an evaluation during the contrived parent-infant interaction for concurrent operant learning of infant vocal behavior via contingent verbal responding (reinforcement) implemented by the mother. Further, it was noted (c) whether or not the mother reported being aware that her responses were influenced by the infant's behavior. Findings showed: the operant conditioning of the maternal verbal behaviors were reinforced by contingent infant attention; and the operant conditioning of infant vocalizations was reinforced by contingent maternal verbal behaviors. No parent reported (1) being aware of the increase in their verbal response reinforced during operant conditioning of parental behavior nor a decrease in those responses during the DRA reversal phase, or (2) noticing a contingency between infant's and mother's response. By binomial 1-tail tests, the verbal-behavior patterns of the 5 mothers were conditioned by infant reinforcement (p < 0.02) and, concurrently, the vocal-response patterns of the 5 infants were conditioned by maternal reinforcement (p < 0.02). A program of systematic empirical research on the determinants of concurrent conditioning within mother-child interaction may provide a way to evaluate the differential effectiveness of interventions aimed at improving parent-child interactions. The work conducted in the present study is one step in this direction. ^

Aedes aegypti pharate first instar aseasonal quiescence cues anticipatory plasticity with implications for urban vector ecology and control

The eggs of the dengue fever vector Aedes aegypti possess the ability to undergo an extended quiescence period hosting a fully developed first instar larvae within its chorion. As a result of this life history stage, pharate larvae can withstand months of dormancy inside the egg where they depend on stored reserves of maternal origin. This adaptation known as pharate first instar quiescence, allows A. aegypti to cope with fluctuations in water availability. An examination of this fundamental adaptation has shown that there are trade-offs associated with it. ^ Aedes aegypti mosquitoes are frequently associated with urban habitats that may contain metal pollution. My research has demonstrated that the duration of this quiescence and the extent of nutritional depletion associated with it affects the physiology and survival of larvae that hatch in a suboptimal habitat; nutrient reserves decrease during pharate first instar quiescence and alter subsequent larval and adult fitness. The duration of quiescence compromises metal tolerance physiology and is coupled to a decrease in metallothionein mRNA levels. My findings also indicate that even low levels of environmentally relevant larval metal stress alter the parameters that determine vector capacity. ^ My research has also demonstrated that extended pharate first instar quiescence can elicit a plastic response resulting in an adult phenotype distinct from adults reared from short quiescence eggs. Extended pharate first instar quiescence affects the performance and reproductive fitness of the adult female mosquito as well as the nutritional status of its progeny via maternal effects in an adaptive manner, i.e., anticipatory phenotypic plasticity results as a consequence of the duration of pharate first instar quiescence and alternative phenotypes may exist for this mosquito with quiescence serving as a cue possibly signaling the environmental conditions that follow a dry period. M findings may explain, in part, A. aegypti's success as a vector and its geographic distribution and have implications for its vector capacity and control.^

Inducible Overexpression of Endothelin-3 in a Transgenic Mouse Leads to Hyperpigmentation That Decreases Over Time

Endothelin-3 (Edn3) has been shown to be an essential environmental cue in melanocyte development. Edn3 and its receptor, EdnrB, are allelic to mouse mutations occurring at the lethal spotting and piebald loci, respectively; these mutations result in hypopigmentation phenotypes. Mutations in the genes for both Edn3 and EdnrB are implicated in human pigmentation disorders such as Waardenburg-Shah syndrome, which is characterized by pigmentation defects, deafness, and megacolon. In this study, a tetracycline-inducible transgenic mouse model that overexpresses Edn3 under the control of the Keratin 5 promoter was shown to produce a hyperpigmentation phenotype that decreases over time. The expression pattern of transgenic Edn3 and its effects on the melanocyte population were examined in transgenic embryos, postnatal skin, and the skin of adult mice that exhibit faded hyperpigmentation. These studies suggest that overexpression of Edn3 in this model is restricted primarily to the roof plate of the neural tube and surface ectoderm in the developing embryo and to keratinocytes in the epidermis of postnatal mice. A decline in transgenic expression and a reduction in the dermal melanocytes and free melanin that characterize the phenotype in juvenile mice were shown to correlate with the fading of the hyperpigmentation phenotype. Transgenic mice in which transgenic expression was repressed (resulting in the disappearance of the hyperpigmentation phenotype) also exhibited a decrease in the dermal melanocyte population. The Edn3-overexpressing mice used in this study might be helpful m understanding human skin conditions characterized by dermal melanocytosis.

A scalable multimedia content processing framework with application to TV shopping

The advent of smart TVs has reshaped the TV-consumer interaction by combining TVs with mobile-like applications and access to the Internet. However, consumers are still unable to seamlessly interact with the contents being streamed. An example of such limitation is TV shopping, in which a consumer makes a purchase of a product or item displayed in the current TV show. Currently, consumers can only stop the current show and attempt to find a similar item in the Web or an actual store. It would be more convenient if the consumer could interact with the TV to purchase interesting items. ^ Towards the realization of TV shopping, this dissertation proposes a scalable multimedia content processing framework. Two main challenges in TV shopping are addressed: the efficient detection of products in the content stream, and the retrieval of similar products given a consumer-selected product. The proposed framework consists of three components. The first component performs computational and temporal aware multimedia abstraction to select a reduced number of frames that summarize the important information in the video stream. By both reducing the number of frames and taking into account the computational cost of the subsequent detection phase, this component component allows the efficient detection of products in the stream. The second component realizes the detection phase. It executes scalable product detection using multi-cue optimization. Additional information cues are formulated into an optimization problem that allows the detection of complex products, i.e., those that do not have a rigid form and can appear in various poses. After the second component identifies products in the video stream, the consumer can select an interesting one for which similar ones must be located in a product database. To this end, the third component of the framework consists of an efficient, multi-dimensional, tree-based indexing method for multimedia databases. The proposed index mechanism serves as the backbone of the search. Moreover, it is able to efficiently bridge the semantic gap and perception subjectivity issues during the retrieval process to provide more relevant results.^

Characterization of the Anti-Quorum Sensing Activity Exhibited by Marine Macro algae of South Florida

Quorum sensing is a communication mechanism employed by many bacteria. The bacteria secrete signal molecules known as acyl homoseriene lactones (AHLs) that cue to population size/density. Bacteria can be alerted of this optimum population by the concentration of these signal molecules. When the concentration of AHLs exceed a threshold valve, they enter the bacterial cell and causes the transcription of genes encoding virulence factors necessary for their colonization and survival. The marine algae Delise a pulchra, found off the coast of Australia is thought to produce compounds that inhibit the activity of the AHLs. The algae employ these compounds, known as furanones, as an anti-fouling agent. We postulated that marine algae of South Florida might contain similar activity; we screened 30 different algal species and found 22 species had the activity. Algal extracts were made from Halimeda incrassata using hexane, chloroform, ethyl acetate and methanol as solvents. The extracts were assayed for anti-quorum sensing activity. The results showed many of the South Florida green algae to possess anti-quorum sensing activity, however extracts of H incrassata did not show quorum sensing inhibition.