The risk of death by predation has been a major driver of group living in many prey animals. Animals must adapt to temporal and spatial variation in predation risk and would benefit from using relevant and reliable sources of information both from conspecifics and heterospecifics to better learn about danger. Research on the effects of group living on antipredator strategy has focused largely on group size. However, sociality is often more complex than simple amalgamations of individuals. Those living in groups are likely exposed to unequal levels of predation risk; some are exposed to more danger than others because of factors related to their age, sex, and spatial or social positioning. An individual’s antipredator strategy should reflect its perceived safety levels. I studied antipredator strategies in blue monkeys (Cercopithecus mitis stuhlmanni) in the Kakamega Forest, Kenya. Blue monkeys are arboreal guenons that live in matrilineally-based social groups and form differentiated social relationships. These social relationships could affect how monkeys respond to variable predation risk. Blue monkeys live in dense, biodiverse rain forests and are preyed upon by both aerial and terrestrial predators. They have a well-developed acoustic communication repertoire and have been known to associate with other primates to reduce predation risk (Cords 1987). I conducted five playback experiments and two sets of observational studies, and used data gathered on social interactions among adult females to further our understanding of how group living affects antipredator strategies. I also used 14 years of social interaction data to explore the heritability of social tendencies. In the first chapter, I present a comprehensive literature review of the connections between group living and antipredator behavior. I describe the effects of group size on antipredator behavior and how research on sociality has shifted towards focusing on individuals’ specific relationships and social connectivity. I then describe several ways in which social connectivity has been shown to influence antipredator behavior. I conclude with future directions and then introduce the dissertation. In the second chapter, I focus on heterospecific eavesdropping. I identified the extent to which blue monkey adult females respond to playbacks of alarm and social calls of two syntopic non-predatory bird species—black-faced rufous warblers (Bathmocercus rufus) and joyful greenbuls (Chlorocichla laetissima). Blue monkeys responded differentially depending on both call type and species. I then evaluated differential responses to conspecific and heterospecific callers, hypothesizing that conspecific signals would trigger stronger anti-predator responses because conspecifics are more relevant signals of risk. I conducted a playback experiment in which adult females were presented simultaneously with one alarm or social call from both conspecifics and warblers (4 combinations of alarm and social calls), or ambient rain forest sound (control). Subjects did not differentiate their responses to simultaneous calls according to the type of playback stimulus. These findings suggest that blue monkeys do not differentiate their responses to alarm calls according to caller relevance. Heterogeneous results among different response variables also highlight the importance of examining multiple modes of antipredator behavior. Next, I examine how an individual’s social connectivity influences its antipredator strategy, hypothesizing that more socially connected individuals would benefit from the proximity of more and closely bonded groupmates in enhancing predator avoidance. In Chapter 3, I evaluate the effects of social connectivity on acute antipredator responses, antipredator vigilance, and responses to signals related to various levels of predator-related threat. I first assessed how social connectivity affects the rate at which adult females exhibit acute antipredator responses (such as diving down in trees, climbing up trees, or alarm calling) and the proportion of responses that are major (lasting >30 s), statistically controlling for age, the presence of an infant, and 2-month “seasons”. I predicted that more socially connected individuals would exhibit less frequent acute antipredator responses because they would be better-informed about risk and therefore would exhibit fewer false alarms. I For the same reasons, I also predicted that they would exhibit more major (vs. minor) responses because false alarms are more likely to involve shorter responses (Cords 1987). Contrary to predictions, however, more closely connected individuals exhibited higher rates of acute antipredator responses, which might reflect their enhanced ability to learn about danger from surrounding groupmates, allowing them to detect more potential threats. There was no evidence that social connectivity was associated with the proportion of responses that lasted >30 s. I also found that the rate of acute antipredator responses and the proportion of responses that lasted >30 s varied with season. I then conducted 90-s focal vigilance follows, to assess how long females exhibit antipredator vigilance after controlling for other social and microhabitat factors (e.g., surrounding vegetation density), which can influence conspecific monitoring and exposure to potential predators. I predicted that more well-connected individuals would exhibit lower levels of antipredator vigilance in the absence of any imminent threats and after controlling for other social and spatial factors. More closely connected individuals who were in the spatial center of their social group did spend less time vigilant, but social connectivity was not associated with vigilance times when subjects were at the group’s edge, where exposure to predators and thus predation risk should be highest and antipredator vigilance should generally be higher. In the spatial center of the group, more closely connected individuals should be in a better position to observe their social partners’ antipredator behavior. Microhabitat also influenced antipredator vigilance in multiple ways, which highlights the spatial variation of perceived predation risk in a complex environment. Lastly, I conducted a playback experiment where I examined responses to signals from conspecifics and heterospecifics that are associated with different levels of threat. I predicted that more poorly connected individuals would respond strongly to all signals that might be associated with predators because they must identify personally whether danger is real, whereas more well-connected individuals would have more differentiated responses because they should be near social partners more frequently and can rely on their partners’ antipredator reactions to assess risk levels. However, although subjects did respond more to direct cues of the predator’s presence (its own calls) than to indirect cues of its presence (alarm calls by conspecifics and heterospecifics), there was no evidence that social connectivity affected responses to playbacks. As expected, stimulus type did affect responses—calls from predators (vs. alarm calls or social calls from non-predators) elicited increased looking responses from subjects, which suggests that stimuli that directly signal predator presence will elicit antipredator behavior regardless of the listener’s social connectivity. Overall, social connectivity seems to play a limited role in blue monkeys’ antipredator strategy but there was some evidence that more well-connected individuals were less vigilant when surrounded by groupmates. The ability to distinguish alarm calls by individual callers has not been well-studied, but animals might benefit from making such distinctions if callers vary in how reliably they signal danger. For decades, researchers have tested whether animals can discriminate callers using the habituation-dishabituation paradigm. After habituating subjects by repeatedly presenting calls of one individual, A, they examine whether subjects dishabituate when they hear the calls of a different individual, B (test stimulus). In Chapter 4, I first review studies that used this paradigm to evaluate whether animals discriminate between conspecific callers and then report on two playback experiments which tested whether wild blue monkeys are capable of such discrimination. My review revealed much methodological variation, particularly in the habituation phase and criteria, statistical analysis, and controls. In experiments, I contrasted two methods of habituation, either presenting a fixed number of stimuli (set after pilot observations) or evaluating responses during the series before progressing to the test. Afterwards, I conducted Wilcoxon signed-rank tests to assess habituation statistically. In the first experiment where I played back a fixed number and rate of calls, it was statistically unclear whether subjects habituated to caller A, despite preliminary observations and similar studies that suggested that the experimental design would be appropriate. Because there was not strong evidence that subjects habituated, I did not evaluate statistically whether subjects differentiated between callers in the full dataset. However, in the second experiment where I assessed habituation during the trial, subjects did habituate to caller A and there was weak support that they dishabituated to caller B, which suggests that caller discrimination may occur. From my experiences, I propose an improved design for studies using the habituation-dishabituation paradigm. Lastly, I explore the mechanisms that drive phenotypic variation in social tendencies (and in turn, social connectivity) in adult females. For natural selection to occur, there must be variation in traits, differentiated fitness benefits based on phenotypes, and heredity or a genetic basis underlying phenotypic variation. The previous chapters highlight the variation in and some of the benefits of social connectivity. In Chapter 5, I conducted an exploratory analysis to examine what factors account for phenotypic variance. Using animal models, I found that both environmental and additive genetic variance accounted for some of the phenotypic variance seen in traits associated with social tendencies (using social connectivity as a proxy). Variance in the social environment (i.e., environmental variance) played a large role in shaping observed phenotypic variation in social connectivity. However, all six of the social network measures examined were weakly heritable, which suggests that there is also a genetic basis for behavioral variation, allowing selection to occur. This dissertation emphasizes the importance of examining both antipredator behavior and sociality using multiple experiments, observations, and measures, while also considering the importance of study species and habitat complexity. The relationship between antipredator behavior and social connectivity is not straightforward and can vary greatly between study systems. Although many of my predictions were not supported, I did find evidence that blue monkeys are receptive to heterospecifics, vary their acute antipredator responses and vigilance based on social relationships with conspecifics, adjust their antipredator vigilance according to spatial positioning, and potentially discriminate between alarm callers. The findings presented here expand our knowledge of how animals learn about predation risk by being attentive to conspecifics and heterospecifics.

The colobine monkey Simias concolor, endemic to the Mentawai Islands, West Sumatra, Indonesia, was studied on two is l ets adjacent to South Pagai. Habitat on these islands was observed and described, and observations were made there from September to November 1987. Group sizes ranged from 2 to >10. Population density may vary with habitat structure. Social groups appear to include one or more females. Contrary to some reports, male and female animals are sexually dimorphic. Inability to identify specific animals or groups prevented mapping of home range areas. Observations are correlated with what has been previously reported about this animal. Future research could be focused on further studies of habitat use and ranging behavior, determination of Simias population densities in possible reserve areas, interspecific interactions, and dietary composition. Without such studies, it is unlikely that adequate management plans can be devised. Prospects for the conservation of this species are reviewed. Suggestions which have been advanced to promote its conservation are also evaluated. The fate of this animal is strongly linked to local, provincial, and national cultural and developmental factors. These include forestry operations, agriculture, hunting, population growth, and transmigration plans.

Understanding spatial and temporal diversity and distribution patterns of species along with the drivers of these patterns has long been a theme of community ecology. Primates, a very species-rich taxonomic group, able to occupy various habitat types, are known for their broad behavioral repertoire and flexibility. This, in turn, allows them to adapt quickly to different ecological conditions. Therefore, they represent an ideal group for examining aspects of community ecology such as species diversity and co-occurrence, distribution patterns, and the ecological determinants of such factors. This dissertation investigates the ways in which members of a multispecies primate community inhabiting a mosaic landscape comprised of flooded and non-flooded forests in northeastern Peru (western Amazonia) distributes themselves across time and space. The main objectives of this study are threefold: 1) to categorize, confirm, and differentiate previously identified habitat types across a mosaic landscape; 2) to examine the diversity and distribution patterns (spatial and temporal) of a large multispecies primate community, and 3) to combine the habitat data with the primate data in order to determine which habitats are occupied by which species and to suggest ways in which the primates share and utilize the landscape throughout an annual cycle. However, special attention is paid to one particular species, the red uakari (Cacajao calvus ucayalii), because of its unusually large home and day ranges and its fluid social system known to change in size and composition daily and even hourly. One of the least studied primates to date, red uakaris, are investigated in order to determine whether or not their behavior varies across habitat types, seasons, and when other primates are present as they navigate a mosaic landscape. By identifying the ways in which uakaris modify their behaviors as they traverse multiple habitats throughout the year, determining both habitat-typical behaviors and seasonal behaviors exhibited by uakaris becomes possible. Moreover, shedding light on the community structure and habitat requirements of one of the least known primates has conservation implications. Research was conducted at the Tahuayo River Amazon Research Center (TRARC), located in northeastern Peru. Systematic data collection on primates and the environment occurred between September 2012 and February 2014, except April 2013. Sampling methods for primates consisted of two parts—a combination of line transect and reconnaissance (recce) surveys in order to determine encounter rates for each species across habitat types and 10-minute interval scan sampling during uakari follows in order to determine the effect that environmental and social factors have on their behavior as they traverse multiple habitats. Environmental sampling occurred in thirty plots established throughout the various habitat types. All trees within the test plots with a diameter breast height (DBH) > 10 cm were marked and the following parameters were recorded: DBH, height, and taxonomic classification. Additionally, plots were monitored monthly to record flooding data in order to determine variation in flooding patterns across habitat types. Plots allowed for the determination of which floristic variables and flood patterns are suitable to differentiate the habitat types described at the TRARC. Results indicate flood duration, average tree height, and (Importance Value Indices [IVIs] at the family, genus, and species levels) are suitable measures for defining and differentiating the five previously identified habitat types at the TRARC. Analysis of the entire primate community showed that the occurrence of species and patterns of distribution across a mosaic landscape vary throughout the year. Distribution patterns are more dependent on forest structure (habitat type) than on rainfall seasonality. While a few primates showed preferences for particular habitats (e.g., Lagothrix) or for certain seasons (e.g. Saimiri), the majority of primates demonstrated more generalized modes of ranging and foraging, with relatively equal encounter rates in all habitats across both wet and dry seasons. Results of the uakari data revealed that habitat and season had an effect on their behavior. There were meaningful differences in the behavioral categories of vocalizing, resting, moving, feeding, infant clinging, and being in polyspecific associations (PSAs) between flooded and non-flooded habitat types. Seasonal differences were seen for vocalizing, traveling, resting, and time spent in PSAs. Although results revealed that red uakaris spent the majority of the time alone (71.86%), when they were in PSAs with one other primate species, squirrel monkeys (Saimiri sciureus) were the most common monkeys. When uakaris were in PSAs with two other species, squirrel monkeys were always present, but woolly monkeys (Lagothrix lagotricha poeppigii) were the second most frequent species. In general, uakaris demonstrated behavioral differences across habitats and seasons. However, some behavioral consistencies across seasons were evident (e.g., moving, feeding, infant clinging), suggesting ecological flexibility in the species. Results of this dissertation provide a basis for understanding ecological parameters best suited for characterizing and differentiating habitat types in upper Amazonia and describe the diversity and distribution patterns of a multispecies community of primates occurring across a mosaic landscape, reinforcing the view that New World primates are largely ecological generalists within forest environments. Understanding the spatio-temporal relationships between species and their environments can aid in predictions of species occurrence/abundance and contribute to better management strategies and conservation prioritization.

No description available.

As theoretical neuroscience has grown as a field, machine learning techniques have played an increasingly important role in the development and evaluation of theories of neural computation. Today, machine learning is used in a variety of neuroscientific contexts from statistical inference to neural network training to normative modeling. This dissertation introduces machine learning techniques for use across the various domains of theoretical neuroscience, and the application of these techniques to build theories of neural circuits. First, we introduce a variety of optimization techniques for normative modeling of neural activity, which were used to evaluate theories of primary motor cortex (M1) and supplementary motor area (SMA). Specifically, neural responses during a cycling task performed by monkeys displayed distinctive dynamical geometries, which motivated hypotheses of how these geometries conferred computational properties necessary for the robust production of cyclic movements. By using normative optimization techniques to predict neural responses encoding muscle activity while ascribing to an “untangled” geometry, we found that minimal tangling was an accurate model of M1. Analyses with trajectory constrained RNNs showed that such an organization of M1 neural activity confers noise robustness, and that minimally “divergent” trajectories in SMA enable the tracking of contextual factors. In the remainder of the dissertation, we focus on the introduction and application of deep generative modeling techniques for theoretical neuroscience. Specifically, both techniques employ recent advancements in approaches to deep generative modeling -- normalizing flows -- to capture complex parametric structure in neural models. The first technique, which is designed for statistical generative models, enables look-up inference in intractable exponential family models. The efficiency of this technique is demonstrated by inferring neural firing rates in a log-gaussian poisson model of spiking responses to drift gratings in primary visual cortex. The second technique is designed for statistical inference in mechanistic models, where the inferred parameter distribution is constrained to produce emergent properties of computation. Once fit, the deep generative model confers analytic tools for quantifying the parametric structure giving rise to emergent properties. This technique was used for novel scientific insight into the nature of neuron-type variability in primary visual cortex and of distinct connectivity regimes of rapid task switching in superior colliculus.

Alcohol abuse is one of the costliest human health problems in the United States. Studies assessing the etiology of alcohol use disorders (AUDs) in adulthood suggest that these disorders are predicted by trait-like differences, such as low or impaired central serotonin or temperamental anxiety. Few studies, however, have assessed neonatal, infant, and adolescent characteristics that lead to alcohol abuse in adolescence. Given that the expression of AUDs is rooted in biological processes, the set of studies presented in this work investigate the early origins of excessive alcohol use in adolescence, with an overall goal of identifying risk factors that may aid in prevention or intervention efforts to deter future alcohol abuse. Due to their evolutionary similarities, as well as similarities in their patterns of alcohol consumption, these studies utilize a nonhuman primate model (Macaca mulatta). A series of three studies investigating neonatal, infant, and adolescent predictors of adolescent alcohol intake were conducted. In study one, we assessed the relationship between neurobehavioral measures at two weeks of life and voluntary alcohol intake in adolescence. In study two, we assessed the relationship between behaviors that reflect an anxiety-like temperament in the first six months of life and excessive alcohol intake in adolescence. In study three, we investigated the relationship between infant and adolescent trait-like stress-induced cortisol and adolescent anxiety-like behaviors and alcohol intake in adolescence. The findings from this set of studies lends itself to an increased understanding of early-life, biologically-based predictors of excessive alcohol intake in adolescence and provides critical information to establishing early interventions for individuals at risk for the development of later AUDs.

No description available.

No description available.

Understanding the host response immediately following mucosal HIV-1 infection will be pivotal in determining whether the immune response induced by a vaccine will successfully sense and control viral replication. In order for effective vaccine strategies and modalities to be developed, these earliest immunological events must be fully assessed in a non-biased manner. Nonhuman primates (NHP), specifically Rhesus macaques (RM), serve as a model to investigate the immunological landscape immediately post-challenge and to define the spatiotemporal path of simian immunodeficiency virus (SIV). SIV infection of RM serves as a model of human HIV infection as it recapitulates many of the virological, immunological, and pathological features of HIV infection in the human host. In this thesis I will test the hypothesis whether transcriptional analysis will allow a sensitive measure of the early innate immune responses that accompany detection of the SIV virus in the periphery. I have determined that an early inflammatory profile arises early in tissues proximal to the challenge site that precedes widespread immune activation and the systemic antiviral interferon response. This study defines in detail the spatiotemporal relationship between virus and host immune response and may be a valuable resource in guiding future vaccine design strategies. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Introduction: Targeted pharmaceuticals for labelling with radio-isotopes for very specific imaging (and possibly later for targeted therapy) play a major role in Theranostics which is currently an important topic in Nuclear Medicine as well as personalised medicine. There was a need for a very specific lung cancer radiopharmaceutical that would specifically be uptaken in integrin 3 expression cells to image patients using a Positron Emission Tomography- Computed Tomography (PET-CT) scanner. Background and problem statement: Cold kits of c (RGDyK)–SCN-Bz-NOTA were kindly donated by Seoul National University (SNU) to help meet Steve Biko Hospital’s need for this type of imaging. These cold kits showed great results internationally in labelling with a 0.1 M 68Ge/68Ga generator (t1/2 of 68Ge and 68Ga are 270.8 days and 67.6 min, respectively). However the same cold kits failed to show reproducible radiolabeling with the 0.6 M generator manufactured under cGMP conditions at iThemba LABS, Cape Town and distributed by IDB Holland, the Netherlands. Materials and methods: There was therefore a need for producing an in-house NOTA-RGD kit that would enable production of clinical 68Ga-NOTA-RGD in high yields from the IDB Holland/iThemba LABS generator. Quality control included ITLC in citric acid to observe labelling efficiency as well as in sodium carbonate to evaluate colloid formation. HPLC was also performed at iThemba LABS as well as Necsa (South African Nuclear Energy Corporation). RGD was obtained from Futurechem, Korea. Kit mass integrity was determined by testing labelling efficiency of 10, 30 and 60 μg of RGD per cold kit. The RGD was buffered with sodium acetate trihydrate. The original kits were dried in a desiccator and in later studies only freeze dried. Manual labelling was also tested. The radiolabelled in-house kit’s ex vivo biodistribution in healthy versus tumour mice were examined by obtaining xenografts. The normal biodistribution was investigated in three vervet monkeys by doing PET-CT scans on a Siemens Biograph TP 40 slice scanner. Results: Cold kit formulation radiolabeling and purification methods were established successfully and SOPs (standard operating procedures) created. HPLC results showed highest radiochemical purity in 60 μg cold kit vials. 68Ga-NOTA-RGD showed increased uptake in tumours of tumour bearing mouse. The cold kit also showed normal distribution according to literature with fast blood clearance and excretion through kidneys into urine, therefore making it a suitable radiopharmaceutical for clinical studies. Conclusion: The in-house prepared cold kit with a 4 month shelf-life was successfully tested in mice and monkeys. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2014