Social and environmental regulation of signal plasticity and signal reliability in the electric fish Brachyhypopomus gauderio

The balance between the costs and benefits of conspicuous signals ensures that the expression of those signals is related to the quality of the bearer. Plastic signals could enable males to maximize conspicuous traits to impress mates and competitors, but reduce the expression of those traits to minimize signaling costs, potentially compromising the information conveyed by the signals. ^ I investigated the effect of signal enhancement on the information coded by the biphasic electric signal pulse of the gymnotiform fish Brachyhypopomus gauderio. Increases in population density drive males to enhance the amplitude of their signals. I found that signal amplitude enhancement improves the information about the signaler's size. Furthermore, I found that the elongation of the signal's second phase conveys information about androgen levels in both sexes, gonad size in males and estrogen levels in females. Androgens link the duration of the signal's second phase to other androgen-mediated traits making the signal an honest indicator of reproductive state and aggressive motivation. ^ Signal amplitude enhancement facilitates the assessment of the signaler's resource holding potential, important for male-male interactions, while signal duration provides information about aggressive motivation to same-sex competitors and reproductive state to the opposite sex. Moreover, I found that female signals also change in accordance to the social environment. Females also increase the amplitude of their signal when population density increases and elongate the duration of their signal's second phase when the sex ratio becomes female-biased. Indicating that some degree of sexual selection operates in females. ^ I studied whether male B. gauderio use signal plasticity to reduce the cost of reproductive signaling when energy is limited. Surprisingly, I found that food limitation promotes the investment in reproduction manifested as signal enhancement and elevated androgen levels. The short lifespan and single breeding season of B. gauderio diminishes the advantage of energy savings and gives priority to sustaining reproduction. I conclude that the electric signal of B. gauderio provides reliable information about the signaler, the quality of this information is reinforced rather than degraded with signal enhancement.^

Entering an academic discourse community: A case study of the coping strategies of eleven English as a Second Language students

This case study follows eleven non-English speaking students as they adapt to community college, content courses. The three classes examined are required freshman classes--Humanities, Social Environment, and Individual in Transition. In order to cope with the demands of these classes, students must penetrate the academic discourse community and have effective relationships with their instructors and their peers. The results of the study are based on interviews with eleven non-native speaking (NNS) students and their instructors and on an analysis of student writing assignments, course syllabi, and exams. Three general areas are examined: (a) students' first-language (L$\sb1$) education, (b) the requirements of their content classes, and (c) the affective factors which influence their adaptation process.^ The case of these students reveals that: (1) Students draw on their L$\sb1$ education, especially in terms of content, as they cope with the demands of these content classes. (2) In some areas L$\sb1$ educational experiences interfere with students' ability to adapt. (3) The content classes require students to have well developed reading, writing, oral, and aural skills. (4) Students must use higher level cognitive skills to be successful in content classes. (5) Affective factors play a role in students' success in content classes. The discussion section includes possible implications of this data for college level English as a Second Language courses. ^

Socioemotional outcomes of children sexually abused during early childhood

This study investigated the nature and impact of the sexual abuse of children ages birth through 6 years. The purpose was to enhance knowledge about this understudied population through examination of: (1) characteristics of the abuse; (2) socioemotional developmental outcomes of young victims; and (3) potential moderating effects of family dynamics. An ecological-developmental theoretical framework was applied. Secondary data analysis was conducted using data collected from the consortium Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). A sample of 250 children was drawn from LONGSCAN data, including children who were sexually abused (n=125) and their nonabused counterparts (n=125), matched on demographic variables. Results revealed that young victims of sexual abuse were disproportionately female (91 girls; 73%). The sexual abuse committed against these youngsters was severe in nature, with 111 children (89%) experiencing contact offenses ranging from fondling to forcible rape. Sixty-two percent of child victims demonstrated borderline, clinical, or less than adequate functioning on normative, expected socioemotional outcomes. Child victims reported low degrees of perceived competence and satisfaction in the social environment. When compared with their nonabused counterparts, child victims demonstrated significantly poorer socioemotional functioning, as evidenced by aggressive behaviors, attention and thought problems. Sexually abused youngsters also reported lower self-perceptions of cognitive and physical competence and maternal acceptance. Family dynamic factors did not significantly moderate the relationships between abuse and socioemotional outcomes, with one exception. The caregivers’ degree of empathy for their children had a significant moderating effect on the children’s social problems. This study contributes to an otherwise scant body of literature on the sexual abuse of preschoolers. Findings provide implications for social work practice, especially in the development of assessment and prevention strategies.

Do long-tailed macaques (Macaca fascicularis) know what others can and cannot hear?

Theory of mind has been defined as the ability to attribute mental sates such as perceptions, knowledge, and belief to others. Studies examining theory of mind in primates have been the center of intense controversy. Much of the research on this subject has focused on designing methodologies to test a primate’s ability to discern the perceptions of others. Namely, many studies have examined an individual’s knowledge of what others can and cannot see. However, other sensory modalities have not undergone as much extensive research. This study aimed to replicate the methodology of a previous experiment with the addition of two novel experimental conditions. Individual long-tailed macaques (Macaca fascicularis) were allowed to approach one of two identical, lidded, clear boxes which had jingle bells attached to them. One of the boxes had the metal bits removed from inside of the jingle bells attached to it, thus creating one “silent” box and leaving the remaining one “noisy”. The experimenter either looked directly at the subject, down at the ground between their knees, or in the novel conditions, turned their back to the subject, or wore a welder’s mask while facing the subject after demonstrating each box’s auditory properties. It was predicted that subjects would choose to approach the silent container in the latter three conditions. The results indicated that subjects selected boxes at random in all conditions. Additionally, in order to explore the possibility of perspective-taking representing a derived trait in the genus Macaca, a phylogeny of the genus was created and annotated to display the presence of perspective-taking as a phenotypic trait in extant species. Three likely evolutionary scenarios leading to the current distribution of perspective-taking are postulated and analyzed for parsimony through the number of assumed gains and losses. The most parsimonious tree suggests that perspective taking could be a conserved trait among the order, giving credence to the argument that some other variable was responsible the negative results in this experiment. It is suggested that the results of the present study represent an artifact of the social environment of the subject population. Moreover, arguments are made for the development of more naturalistic studies for examining mental state attribution in primates.

The effect of male -male competition and its underlying regulatory mechanisms on the electric signal of the gymnotiform fish Brachyhypopomus gauderio

Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. The ability to dynamically regulate the signal in a context-dependent manner can further minimize the costs of male aggressive interactions. Such is the case in the gymnotiform fish Brachyhypopomus gauderio, which, by coupling its electric organ discharge (EOD) waveform to endocrine systems with circadian, seasonal, and behavioral drivers, can regulate its signal to derive the greatest reproductive benefit. My dissertation research examined the functional role of the EOD plasticity observed in male B. gauderio and the physiological mechanisms that regulate the enhanced male EOD. To evaluate whether social competition drives the EOD changes observed during male-male interactions, I manipulated the number of males in breeding groups to create conditions that exemplified low and high competition and measured their EOD and steroid hormone levels. My results showed that social competition drives the enhancement of the EOD amplitude of male B. gauderio. In addition, changes in the EOD of males due to changes in their social environment were paralleled by changes in the levels of androgens and cortisol. I also examined the relationship between body size asymmetry, EOD waveform parameters, and aggressive physical behaviors during male-male interactions in B. gauderio, in order to understand more fully the role of EOD waveforms as reliable signals. While body size was the best determinant of dominance in male B. gauderio, EOD amplitude reliably predicted body condition, a composite of length and weight, for fish in good body condition. To further characterize the mechanisms underlying the relationship between male-male interactions and EOD plasticity, I identified the expression of the serotonin receptor 1A, a key player in the regulation of aggressive behavior, in the brains of B. gauderio. I also identified putative regulatory regions in this receptor in B. gauderio and other teleost fish, highlighting the presence of additional plasticity. In conclusion, male-male competition seems to be a strong selective driver in the evolution of the male EOD plasticity in B. gauderio via the regulatory control of steroid hormones and the serotonergic system.

Syndemic health disparities and resilience processes related to HIV transmission risk among African American/Black men in south Florida

Rates of HIV infection continue to climb among minority populations and men who have sex with men (MSM), with African American/Black MSM being especially impacted. Numerous studies have found HIV transmission risk to be associated with many health and social disparities resulting from larger environmental and structural forces. Using anthropological and social environment-based theories of resilience that focus on individual agency and larger social and environmental structures, this dissertation employed a mixed methods design to investigate resilience processes among African American/Black MSM.^ Quantitative analyses compared African American/Black (N=108) and Caucasian/White (N=250) MSM who participated in a previously conducted randomized controlled trial (RCT) of sexual and substance use risk reduction interventions. At RCT study entry, using past 90 day recall periods, there were no differences in unprotected sex frequency, however African American/Black MSM reported higher frequencies of days high (P<0.000), and drugs and sex used in combination (P<0.000), and substance dependence (P<0.000) and lower levels of social support (P<0.024) compared to Caucasian/White MSM. At 12- month follow-up, multi-level statistical models found that African American/Black MSM reduced their frequencies of days high and unprotected sex at greater rates than Caucasian/White MSM (P<0.001).^ Qualitative data collected among a sub-sample of African American/Black MSM from the RCT (N=21) described the men's experiences of living with multiple health and social disparities and the importance of RCT study assessments in facilitating reductions in risk behaviors. A cross-case analysis showed different resilience processes undertaken by men who experienced low socioeconomic status, little family support, and homophobia (N=16) compared to those who did not (N=5).^ The dissertation concludes that resilience processes to HIV transmission risk and related health and social disparities among African American/Black MSM varies and are dependent on specific social environmental factors, including social relationships, structural homophobia, and access to social, economic, and cultural capital. Men define for themselves what it means to be resilient within their social environment. These conclusions suggest that both individual and structural-level resilience-based HIV prevention interventions are needed.^

The Effect of male-male competition and its Underlying Regulatory Mechanisms on the Electric Signal of the Gymnotiform fish Brachyhypopomus gauderio

Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. The ability to dynamically regulate the signal in a context-dependent manner can further minimize the costs of male aggressive interactions. Such is the case in the gymnotiform fish Brachyhypopomus gauderio, which, by coupling its electric organ discharge (EOD) waveform to endocrine systems with circadian, seasonal, and behavioral drivers, can regulate its signal to derive the greatest reproductive benefit. My dissertation research examined the functional role of the EOD plasticity observed in male B. gauderio and the physiological mechanisms that regulate the enhanced male EOD. To evaluate whether social competition drives the EOD changes observed during male-male interactions, I manipulated the number of males in breeding groups to create conditions that exemplified low and high competition and measured their EOD and steroid hormone levels. My results showed that social competition drives the enhancement of the EOD amplitude of male B. gauderio. In addition, changes in the EOD of males due to changes in their social environment were paralleled by changes in the levels of androgens and cortisol. I also examined the relationship between body size asymmetry, EOD waveform parameters, and aggressive physical behaviors during male-male interactions in B. gauderio, in order to understand more fully the role of EOD waveforms as reliable signals. While body size was the best determinant of dominance in male B. gauderio, EOD amplitude reliably predicted body condition, a composite of length and weight, for fish in good body condition. To further characterize the mechanisms underlying the relationship between male-male interactions and EOD plasticity, I identified the expression of the serotonin receptor 1A, a key player in the regulation of aggressive behavior, in the brains of B. gauderio. I also identified putative regulatory regions in this receptor in B. gauderio and other teleost fish, highlighting the presence of additional plasticity. In conclusion, male-male competition seems to be a strong selective driver in the evolution of the male EOD plasticity in B. gauderio via the regulatory control of steroid hormones and the serotonergic system.

Socioemotional Outcomes of Children Sexually Abused during Early Childhood

This study investigated the nature and impact of the sexual abuse of children ages birth through 6 years. The purpose was to enhance knowledge about this understudied population through examination of: (1) characteristics of the abuse; (2) socioemotional developmental outcomes of young victims; and (3) potential moderating effects of family dynamics. An ecological-developmental theoretical framework was applied. Secondary data analysis was conducted using data collected from the consortium Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). A sample of 250 children was drawn from LONGSCAN data, including children who were sexually abused (n=125) and their nonabused counterparts (n=125), matched on demographic variables. Results revealed that young victims of sexual abuse were disproportionately female (91 girls; 73%). The sexual abuse committed against these youngsters was severe in nature, with 111 children (89%) experiencing contact offenses ranging from fondling to forcible rape. Sixty-two percent of child victims demonstrated borderline, clinical, or less than adequate functioning on normative, expected socioemotional outcomes. Child victims reported low degrees of perceived competence and satisfaction in the social environment. When compared with their nonabused counterparts, child victims demonstrated significantly poorer socioemotional functioning, as evidenced by aggressive behaviors, attention and thought problems. Sexually abused youngsters also reported lower self-perceptions of cognitive and physical competence and maternal acceptance. Family dynamic factors did not significantly moderate the relationships between abuse and socioemotional outcomes, with one exception. The caregivers’ degree of empathy for their children had a significant moderating effect on the children’s social problems. This study contributes to an otherwise scant body of literature on the sexual abuse of preschoolers. Findings provide implications for social work practice, especially in the development of assessment and prevention strategies.

Entering an academic discourse community: A case study of the coping strategies of eleven english as a second language students

This case study follows eleven non-English speaking students as they adapt to community college, content courses. The three classes examined are required freshman classes--Humanities, Social Environment, and Individual in Transition. In order to cope with the demands of these classes, students must penetrate the academic discourse community and have effective relationships with their instructors and their peers. The results of the study are based on interviews with eleven non-native speaking (NNS) students and their instructors and on an analysis of student writing assignments, course syllabi, and exams. Three general areas are examined: (a) students' first-language (L1) education, (b) the requirements of their content classes, and (c) the affective factors which influence their adaptation process. The case of these students reveals that: 1. Students draw on their L1 education, especially in terms of content, as they cope with the demands of these content classes. 2. In some areas L1 educational experiences interfere with students' ability to adapt. 3. The content classes require students to have well developed reading, writing, oral, and aural skills. 4. Students must use higher level cognitive skills to be successful in content classes. 5. Affective factors play a role in students' success in content classes. The discussion section includes possible implications of this data for college level English as a Second Language courses.

Mand – to Tact Training Transfer Acquisition Rates in Children Diagnosed with Autism Spectrum Disorder with Limited Verbal Skills

Autism Spectrum Disorder () is defined as “the presence of severe and pervasive impairments in reciprocal social interaction and in verbal and nonverbal communication skills” (Diagnostic & Statistical Manual, 2000). It is estimated that 1 in 68 children across the United States are diagnosed with ASD. One of the most common delays that children diagnosed with ASD experience are language delays. Children with ASD that have a language delay will often develop maladaptive behaviors as a result of poor communication skills (Carr & Durand, 1985). The failure to develop mand acquisition in typical fashion results in behaviors ranging from social withdrawal to self-injurious behaviors (Cooper et. al, 2007). A lack of a strong tact repertoire can further impede and complicate the learning of other necessary components of language due to the inability to successfully label items and events in the physical environment of the child. The purpose of this study is to replicate with a reversal in verbal operant training of the procedures described in Wallace et al. (2006) in which two children with ASD underwent tact training to facilitate the formation of mands; essentially this study aims to accomplish mand training first to establish as tact. It is hypothesized that mand training will result in a greater repertoire of tacts due to strength of the relationship between mands and the control over the social environment (Cooper et al., 2007). The two children in the study will be taught to mand items that will be ranked in order of preference via stimulus preference assessment. This study is of great importance due to the indispensable value of effective social communication skills. Data gathered on improving communication skills is of great value to the ASD community as the implications for functional skills result in better communication with family and greater control of individual functioning.

Mand – to Tact Training Transfer Acquisition Rates in Children Diagnosed with Autism Spectrum Disorder with Limited Verbal Skills

Autism Spectrum Disorder () is defined as “the presence of severe and pervasive impairments in reciprocal social interaction and in verbal and nonverbal communication skills” (Diagnostic & Statistical Manual, 2000). It is estimated that 1 in 68 children across the United States are diagnosed with ASD. One of the most common delays that children diagnosed with ASD experience are language delays. Children with ASD that have a language delay will often develop maladaptive behaviors as a result of poor communication skills (Carr & Durand, 1985). The failure to develop mand acquisition in typical fashion results in behaviors ranging from social withdrawal to self-injurious behaviors (Cooper et. al, 2007). A lack of a strong tact repertoire can further impede and complicate the learning of other necessary components of language due to the inability to successfully label items and events in the physical environment of the child. The purpose of this study is to replicate with a reversal in verbal operant training of the procedures described in Wallace et al. (2006) in which two children with ASD underwent tact training to facilitate the formation of mands; essentially this study aims to accomplish mand training first to establish as tact. It is hypothesized that mand training will result in a greater repertoire of tacts due to strength of the relationship between mands and the control over the social environment (Cooper et al., 2007). The two children in the study will be taught to mand items that will be ranked in order of preference via stimulus preference assessment. This study is of great importance due to the indispensable value of effective social communication skills. Data gathered on improving communication skills is of great value to the ASD community as the implications for functional skills result in better communication with family and greater control of individual functioning.

Syndemic Health Disparities and Resilience Processes Related to HIV Transmission Risk among African American/Black Men in South Florida

Rates of HIV infection continue to climb among minority populations and men who have sex with men (MSM), with African American/Black MSM being especially impacted. Numerous studies have found HIV transmission risk to be associated with many health and social disparities resulting from larger environmental and structural forces. Using anthropological and social environment-based theories of resilience that focus on individual agency and larger social and environmental structures, this dissertation employed a mixed methods design to investigate resilience processes among African American/Black MSM. Quantitative analyses compared African American/Black (N=108) and Caucasian/White (N=250) MSM who participated in a previously conducted randomized controlled trial (RCT) of sexual and substance use risk reduction interventions. At RCT study entry, using past 90 day recall periods, there were no differences in unprotected sex frequency, however African American/Black MSM reported higher frequencies of days high (P Qualitative data collected among a sub-sample of African American/Black MSM from the RCT (N=21) described the men’s experiences of living with multiple health and social disparities and the importance of RCT study assessments in facilitating reductions in risk behaviors. A cross-case analysis showed different resilience processes undertaken by men who experienced low socioeconomic status, little family support, and homophobia (N=16) compared to those who did not (N=5). The dissertation concludes that resilience processes to HIV transmission risk and related health and social disparities among African American/Black MSM varies and are dependent on specific social environmental factors, including social relationships, structural homophobia, and access to social, economic, and cultural capital. Men define for themselves what it means to be resilient within their social environment. These conclusions suggest that both individual and structural-level resilience-based HIV prevention interventions are needed.