Browsing by Author "Earley, Ryan L."
Now showing 1 - 20 of 31
Results Per Page
Sort Options
Item Aggression and Related Behavioral Traits: The Impact of Winning and Losing and the Role of Hormones(Oxford University Press, 2012) Chang, Ching; Li, Cheng-Yu; Earley, Ryan L.; Hsu, Yuying; National Taiwan Normal University; University of Alabama TuscaloosaA suite of correlated behaviors reflecting between-individual consistency in behavior across multiple situations is termed a "behavioral syndrome." Researchers have suggested that a cause for the correlation between different behaviors might lie in the neuroendocrine system. In this study, we examined the relationships between aggressiveness (a fish's readiness to perform gill display to its mirror image) and each of boldness (the readiness to emerge from a shelter), exploratory tendency (the readiness to approach a novel shelter), and learning performance (the probability of entering the correct reservoir in a T-maze test) in a mangrove rivulus, Kryptolebias marmoratus. We explored the possibility that the relationships between them arise because these behaviors are all modulated by cortisol and testosterone. We also tested the stability of the relationships between these behaviors shortly after using a winning or losing experience to alter individuals' aggressiveness. The results were that aggressiveness correlated positively with boldness and the tendency to explore, and that these three behavioral traits were all positively correlated with pre-experience testosterone levels. Aggressiveness and boldness also positively correlated with pre-experience cortisol levels; exploratory tendency did not. The relationship between aggressiveness and boldness appeared to be stronger than that between either of them and exploratory tendency. These results suggest that testosterone and cortisol play important roles in mediating the correlations between these behavioral traits. Learning performance was not significantly correlated with the other behavioral traits or with levels of testosterone or cortisol. Recent experience in contests influenced individuals' aggressiveness, tendency to explore, and learning performance but not their boldness; individuals that received a winning experience were quicker to display to their mirror image and performed better in the learning task but were slower to approach a novel object than were individuals that lost. Contest experience did not, however, significantly influence the relationships between aggressiveness and any of boldness, exploratory tendency, or learning performance. The results show that the individual components of a suite of correlated behaviors can preserve a flexibility to respond differently to environmental stimuli.Item Blood lactate and electromyograpy during aerobic exercise(University of Alabama Libraries, 2017) Snarr, Ronald Lee; Bishop, Phillip A.; Esco, Michael R.; University of Alabama TuscaloosaThe assessment of lactate threshold (LT) is an important measurement to prescribe training intensities and monitor chronic adaptations in athletes. A non-invasive method, electromyography (EMG), has been suggested as an alternative approach to LT testing. Three experiments determined the ability of EMG incorporated into compression shorts to estimate LT, effect of exercise on LT and EMG threshold (EMGT), and determined the most appropriate filtering method of the EMG signal to estimate LT. In the first investigation, participants performed an incremental exercise test while blood lactate and EMG were measured. EMG displayed no differences from blood lactate in the ability to predict LT (p = 0.08). EMGT and LT showed a moderate correlation (r = 0.68, p = 0.01) between the determination of work rates. The EMGT occurred at the same stage of the incremental test as LT in 11 out of the 13 participants (85%). No differences were seen between percentage of maximal oxygen consumption or percentage of maximal heart rate between LT and EMGT. In the second study, the effect of exercise on LT and EMGT measurement was evaluated. Participants completed two maximal exercise tests separated by 30-minutes of exercise. Individual agreement demonstrated that pre- and post-exercise LT occurred at the same work rate in 5 of 10 participants; while pre- and post- EMGT occurred at the same work rate in 6 of 10 participants. Results indicated no significant difference between the work rates of the pre-exercise LT and EMGT (0.43), although post-trial LT was significantly lower than post-trial EMGT (p = 0.007). No difference in test stage were seen between the pre- and post-exercise EMGT; however, post-trial LT occurred at a lower work rate as compared to pre-trial LT (p = 0.03). In the final study, four popular methods of EMG signal transformation were examined in order to determine their effectiveness in estimating LT. The methods used were root mean square (10- and 60-second epochs), 60- second Smoothing, and 60-secons peak-amplitude averaging. Results indicated no differences in the ability of any signal processing variations to predict LT or in relation to %VO2peak at each threshold level. In conclusion, EMG has been demonstrated to be a viable tool to estimate LT and may provide a reliable low-cost, non-invasive method of prescribing training intensities based upon EMGT testing.Item Cardiovascular drift and maximal oxygen uptake during heat stress in women(University of Alabama Libraries, 2019) Stone, Tori; Wingo, Jonathan E.; University of Alabama TuscaloosaDuring prolonged constant-rate exercise, heart rate and stroke volume progressively increase and decrease, respectively, characterizing cardiovascular (CV) drift. CV drift is greater when driven by hyperthermia and generally results in proportional decreases in maximal oxygen uptake (V̇O2max). Less is known about CV drift and decrements in V̇O2max in women because nearly all studies on this topic focused on men. This dissertation determined the effects of hormonal status, fitness level, and sudomotor function on CV drift and V̇O2max in women. In 3 separate studies, CV drift was measured during 45 min of cycling in 35 °C, immediately followed by measurement of V̇O2max. V̇O2max also was measured after 15 min in a separate trial to assess changes in V̇O2max over the same time interval that CV drift occurred. Study 1 compared follicular (FP) and luteal phases (LP) of the menstrual cycle during exercise at 60% V̇O2max. Resting and exercise core temperatures (Tre) were higher in LP, but increases during exercise (ΔTre) were similar to FP, so the CV drift/V̇O2max relationship was not modulated by phase. Study 2 compared high-fit (HI) and low-fit (LO) women during exercise at 60% V̇O2max (REL) and 500 W of metabolic heat production (FIXED). During REL, heat production and ΔTre were significantly greater in HI versus LO, as were magnitudes of CV drift and decrements in V̇O2max. During FIXED, heat production, ΔTre, CV drift, and V̇O2max were similar between groups. Study 3 compared women to men during exercise at 500 W of metabolic heat production. For women, sweating plateaued and accelerated ΔTre compared to men, but differences in CV drift and V̇O2max were not statistically discernible between sexes. In conclusion, the relationship between CV drift and V̇O2max during heat stress does not change across the menstrual cycle and is not affected by fitness level, independent of metabolic heat production. The relationship is similar between men and women during 45 min of exercise at the same, relatively high load.Item Development of G: a test in an amphibious fish(Springer Nature, 2019) Styga, Joseph M.; Houslay, Thomas M.; Wilson, Alastair J.; Earley, Ryan L.; University of Alabama Tuscaloosa; University of Cambridge; University of ExeterHeritable variation in, and genetic correlations among, traits determine the response of multivariate phenotypes to natural selection. However, as traits develop over ontogeny, patterns of genetic (co)variation and integration captured by the G matrix may also change. Despite this, few studies have investigated how genetic parameters underpinning multivariate phenotypes change as animals pass through major life history stages. Here, using a self-fertilizing hermaphroditic fish species, mangrove rivulus (Kryptolebias marmoratus), we test the hypothesis that G changes from hatching through reproductive maturation. We also test Cheverud's conjecture by asking whether phenotypic patterns provide an acceptable surrogate for patterns of genetic (co)variation within and across ontogenetic stages. For a set of morphological traits linked to locomotor (jumping)performance, we find that the overall level of genetic integration (as measured by the mean-squared correlation across all traits) does not change significantly over ontogeny. However, we also find evidence that some trait-specific genetic variances and pairwise genetic correlations do change. Ontogenetic changes in G indicate the presence of genetic variance for developmental processes themselves, while also suggesting that any genetic constraints on morphological evolution may be age-dependent. Phenotypic correlations closely resembled genetic correlations at each stage in ontogeny. Thus, our results are consistent with the premise that-at least under common environment conditions-phenotypic correlations can be a good substitute for genetic correlations in studies of multivariate developmental evolution.Item Development of G: a test in an amphibious fish (vol 122, pg 696, 2018)(Nature Portfolio, 2019) Styga, Joseph M.; Houslay, Thomas M.; Wilson, Alastair J.; Earley, Ryan L.; University of Alabama Tuscaloosa; University of Cambridge; University of ExeterItem DNA methylation in adults and during development of the self-fertilizing mangrove rivulus, Kryptolebias marmoratus(Wiley, 2018) Fellous, Alexandre; Labed-Veydert, Tiphaine; Locrel, Melodie; Voisin, Anne-Sophie; Earley, Ryan L.; Silvestre, Frederic; University of Namur; University of Alabama TuscaloosaIn addition to genetic variation, epigenetic mechanisms such as DNA methylation might make important contributions to heritable phenotypic diversity in populations. However, it is often difficult to disentangle the contributions of genetic and epigenetic variation to phenotypic diversity. Here, we investigated global DNA methylation and mRNA expression of the methylation-associated enzymes during embryonic development and in adult tissues of one natural isogenic lineage of mangrove rivulus fish, Kryptolebias marmoratus. Being the best-known self-fertilizing hermaphroditic vertebrate affords the opportunity to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. Using the LUminometric Methylation Assay (LUMA), we described variable global DNA methylation at CpG sites in adult tissues, which differed significantly between hermaphrodite ovotestes and male testes (79.6% and 87.2%, respectively). After fertilization, an immediate decrease in DNA methylation occurred to 15.8% in gastrula followed by re-establishment to 70.0% by stage 26 (liver formation). Compared to zebrafish, at the same embryonic stages, this reprogramming event seems later, deeper, and longer. Furthermore, genes putatively encoding DNA methyltransferases (DNMTs), Ten-Eleven Translocation (TET), and MeCP2 proteins showed specific regulation in adult gonad and brain, and also during early embryogenesis. Their conserved domains and expression profiles suggest that these proteins play important roles during reproduction and development. This study raises questions about mangrove rivulus' peculiar reprogramming period in terms of epigenetic transmission and physiological adaptation of individuals to highly variable environments. In accordance with the general-purpose genotype model, epigenetic mechanisms might allow for the expression of diverse phenotypes among genetically identical individuals. Such phenotypes might help to overcome environmental challenges, making the mangrove rivulus a valuable vertebrate model for ecological epigenetic studies. The mangrove rivulus, Kryptolebias marmoratus, is the best-known self-fertilizing hermaphroditic vertebrate that allows to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. The reprogramming event is later, more dramatic and longer than in other described vertebrates. High evolutionary conservation and expression patterns of DNMT, TET, and MeCP2 proteins in K. marmoratus suggest biological roles for each member in gametogenesis and development.Item Does Body Shape in Fundulus Adapt to Variation in Habitat Salinity?(Frontiers, 2019) Styga, Joseph M.; Pienaar, Jason; Scott, Peter A.; Earley, Ryan L.; University of Alabama Tuscaloosa; University of California Los AngelesUnderstanding the ecological pressures that generate variation in body shape is important because body shape profoundly affects physiology and overall fitness. Using Fundulus, a genus of fish that exhibits considerable morphological and physiological variation with evidence of repeated transitions between freshwater and saltwater habitats, we tested whether habitat salinity has influenced the macroevolution of body shape at different stages in development. After accounting for phylogenetic inertia, we find that body shape deviates from the optimal streamlined shape in a manner consistent with different osmoregulatory pressures exerted by different salinity niches at every stage of ontogeny that we examined. We attribute variation in body shape to differential selection for osmoregulatory efficiency because: (1) saline intolerant species developed body shapes with relatively low surface areas more conducive to managing osmoregulatory demands and (2) inland species that exhibit high salinity tolerances have body shapes similar to saline tolerant species in marine environments.Item Examining the association between callous-unemotional traits, bullying and victimization in preschoolers(University of Alabama Libraries, 2012) O'Brien, Christopher; Tullos-Gilpin, Ansley; University of Alabama TuscaloosaPeer victimization and bullying are a widespread problem among children, which can lead to mental, behavioral and physical adjustment problems. Due to these excessive costs, much attention has been directed at identifying and examining risk factors for engaging in bullying behaviors. Previous research has examined callous-unemotional (CU) traits as a risk factor for bullying and victimization. The present study examined the impact of CU traits in putting preschoolers at risk for bullying and victimization as well as how social-neuro-cognitive variables may moderate this relation. CU traits were a significant predictor for both bullying and victimization. Furthermore, cognitive inhibition and verbal intelligence moderated the relation between CU traits and bullying. However, no moderation effects were found for victimization. Other frequently studied predictors, such as age or income, did not discriminate within the sample. These findings suggest that in a preschool sample, CU traits not only serve as risk factors for bullying and being victimized, but are also associated with normative social cognitive functioning.Item Fighting experience alters brain androgen receptor expression dependent on testosterone status(Royal Society of London, 2014) Li, Cheng-Yu; Earley, Ryan L.; Huang, Shu-Ping; Hsu, Yuying; National Taiwan Normal University; University of Alabama TuscaloosaContest decisions are influenced by the outcomes of recent fights (winner-loser effects). Steroid hormones and serotonin are closely associated with aggression and therefore probably also play important roles in mediating winner-loser effects. In mangrove rivulus fish, Kryptolebias marmoratus, individuals with higher testosterone (T), 11-ketotestosterone and cortisol levels are more capable of winning, but titres of these hormones do not directly mediate winner-loser effects. In this study, we investigated the effects of winning/losing experiences on brain expression levels of the receptor genes for androgen (AR), oestrogen alpha/beta (ER alpha/beta), glucocorticoid (GR) and serotonin (5-HT1AR). The effect of contest experience on AR gene expression depended on T levels: repeated losses decreased, whereas repeated wins increased AR gene expression in individuals with low T but not in individuals with medium or high T levels. These results lend strong support for AR being involved in mediating winner-loser effects, which, in previous studies, were more detectable in individuals with lower T. Furthermore, the expression levels of ER alpha/beta, 5-HT1AR and GR genes were higher in individuals that initiated contests against larger opponents than in those that did not. Overall, contest experience, underlying endocrine state and hormone and serotonin receptor expression patterns interacted to modulate contest decisions jointly.Item Fitness Costs of Maternal Ornaments and Prenatal Corticosterone Manifest as Reduced Offspring Survival and Sexual Ornament Expression(Frontiers, 2022) Assis, Braulio A.; Avery, Julian D.; Earley, Ryan L.; Langkilde, Tracy; Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaColorful traits (i.e., ornaments) that signal quality have well-established relationships with individual condition and physiology. Furthermore, ornaments expressed in females may have indirect fitness effects in offspring via the prenatal physiology associated with, and social consequences of, these signaling traits. Here we examine the influence of prenatal maternal physiology and phenotype on condition-dependent signals of their offspring in adulthood. Specifically, we explore how prenatal maternal testosterone, corticosterone, and ornament color and size correlate with female and male offspring survival to adulthood and ornament quality in the lizard Sceloporus undulatus. Offspring of females with more saturated badges and high prenatal corticosterone were less likely to survive to maturity. Badge saturation and area were negatively correlated between mothers and their male offspring, and uncorrelated to those in female offspring. Maternal prenatal corticosterone was correlated negatively with badge saturation of male offspring in adulthood. Our results indicate that maternal ornamentation and prenatal concentrations of a stress-relevant hormone can lead to compounding fitness costs by reducing offspring survival to maturity and impairing expression of a signal of quality in surviving males. This mechanism may occur in concert with social costs of ornamentation in mothers. Intergenerational effects of female ornamentation and prenatal stress may be interdependent drivers of balancing selection and intralocus sexual conflict over signaling traits.Item Genetic integration of behavioural and endocrine components of the stress response(eLife Sciences Publications, 2022) Houslay, Thomas M.; Earley, Ryan L.; White, Stephen J.; Lammers, Wiebke; Grimmer, Andrew J.; Travers, Laura M.; Johnson, Elizabeth L.; Young, Andrew J.; Wilson, Alastair; University of Exeter; University of Alabama Tuscaloosa; University of East AngliaThe vertebrate stress response comprises a suite of behavioural and physiological traits that must be functionally integrated to ensure organisms cope adaptively with acute stressors. Natural selection should favour functional integration, leading to a prediction of genetic integration of these traits. Despite the implications of such genetic integration for our understanding of human and animal health, as well as evolutionary responses to natural and anthropogenic stressors, formal quantitative genetic tests of this prediction are lacking. Here, we demonstrate that acute stress response components in Trinidadian guppies are both heritable and integrated on the major axis of genetic covariation. This integration could either facilitate or constrain evolutionary responses to selection, depending upon the alignment of selection with this axis. Such integration also suggests artificial selection on the genetically correlated behavioural responses to stress could offer a viable non-invasive route to the improvement of health and welfare in captive animal populations.Item The Genome of the Self-Fertilizing Mangrove Rivulus Fish, Kryptolebias marmoratus: A Model for Studying Phenotypic Plasticity and Adaptations to Extreme Environments(Oxford University Press, 2016) Kelley, Joanna L.; Yee, Muh-Ching; Brown, Anthony P.; Richardson, Rhea R.; Tatarenkov, Andrey; Lee, Clarence C.; Harkins, Timothy T.; Bustamante, Carlos D.; Earley, Ryan L.; Washington State University; Carnegie Institution for Science; Stanford University; University of California Irvine; Thermo Fisher Scientific; University of Alabama TuscaloosaThe mangrove rivulus (Kryptolebias marmoratus) is one of two preferentially self-fertilizing hermaphroditic vertebrates. This mode of reproduction makes mangrove rivulus an important model for evolutionary and biomedical studies because long periods of self-fertilization result in naturally homozygous genotypes that can produce isogenic lineages without significant limitations associated with inbreeding depression. Over 400 isogenic lineages currently held in laboratories across the globe show considerable among lineage variation in physiology, behavior, and life history traits that is maintained under common garden conditions. Temperature mediates the development of primary males and also sex change between hermaphrodites and secondary males, which makes the system ideal for the study of sex determination and sexual plasticity. Mangrove rivulus also exhibit remarkable adaptations to living in extreme environments, and the system has great promise to shed light on the evolution of terrestrial locomotion, aerial respiration, and broad tolerances to hypoxia, salinity, temperature, and environmental pollutants. Genome assembly of the mangrove rivulus allows the study of genes and gene families associated with the traits described above. Here we present a de novo assembled reference genome for the mangrove rivulus, with an approximately 900Mb genome, including 27,328 annotated, predicted, protein-coding genes. Moreover, we are able to place more than 50% of the assembled genome onto a recently published linkage map. The genome provides an important addition to the linkage map and transcriptomic tools recently developed for this species that together provide critical resources for epigenetic, transcriptomic, and proteomic analyses. Moreover, the genome will serve as the foundation for addressing key questions in behavior, physiology, toxicology, and evolutionary biology.Item Hemodynamic Responses to Resistance Exercise with Blood Flow Restriction Using a Practical Method Versus a Traditional Cuff-Inflation System(MDPI, 2022) Winchester, Lee J.; Blake, Morgan T.; Fleming, Abby R.; Aguiar, Elroy J.; Fedewa, Michael, V; Esco, Michael R.; Earley, Ryan L.; University of Alabama TuscaloosaThe aim of this study was to examine the potential differences in acute hemodynamic responses and muscular performance outcomes following resistance exercise between traditional blood flow restriction (TRA(BFR)) and a novel band tissue flossing method (BTFBFR). METHODS: Fifteen healthy young adults (23.27 +/- 2.69 years) visited the lab for three sessions (>= 72 h apart). Each session's exercise consisted of three sets of 20 maximum-effort seated leg extensions and flexions with one of three conditions: control (CON), TRA(BFR) (50% limb occlusion pressure (LOP)), or BTFBFR. During TRA(BFR) and BTFBFR sessions, occlusion was applied immediately prior to exercise and removed immediately after. Heart rate was collected prior to exercise, after onset of occlusion, immediately after exercise, and one-minute after removal of occlusion. Ultrasonography was performed prior to, and at least 30 s after, occlusion. RESULTS: BTFBFR caused greater reductions in arterial distance (14.28%, p = 0.010) and arterial area (28.43%, p = 0.020) than TRA(BFR). BTFBFR was able to significantly reduce arterial flow below pre-occlusion values, while TRA(BFR) did not. Both conditions caused significant elevations in heart rate following occlusion (TRA(BFR): +4.67 bpm, p = 0.046 and BTFBFR: +6.07 bpm, p = 0.034), immediately post-exercise (TRA(BFR): +56.93 bpm, p < 0.001 and BTFBFR: +52.79 bpm, p < 0.001) and one-minute post-exercise (TRA(BFR): +15.71, p = 0.003 and BTFBFR: +14.57, p < 0.001). Only BTFBFR caused significant reductions in performance as measured by average power per repetition. CONCLUSIONS: BTFBFR causes a more exaggerated decrease in arterial blood flow as well as muscular power when compared to traditional TRA(BFR) at 50% of LOP.Item Honest signals and sexual conflict: Female lizards carry undesirable indicators of quality(Wiley, 2021) Assis, Braulio A.; Avery, Julian D.; Tylan, Catherine; Engler, Heather, I; Earley, Ryan L.; Langkilde, Tracy; Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaSex differences in animal coloration often result from sex-dependent regulatory mechanisms. Still, some species exhibit incomplete sexual dimorphism as females carry a rudimentary version of a costly male trait, leading to intralocus sexual conflict. The underlying physiology and condition dependence of these traits can inform why such conflicts remain unresolved. In eastern fence lizards (Sceloporus undulatus), blue iridophore badges are found in males and females, but melanin pigmentation underneath and surrounding badges is male-exclusive. We track color saturation and area of badges across sexual maturity, and their relationship to individual quality (body condition and immunocompetence) and relevant hormones (testosterone and corticosterone). Saturation and testosterone were positively correlated in both sexes, but hormone and trait had little overlap between males and females. Saturation was correlated with body condition and immunocompetence in males but not in females. Co-regulation by androgens may have released females from resource allocation costs of color saturation, even when in high condition. Badge area was independent of testosterone, but associated with low corticosterone in females, indicating that a nonsex hormone underlies incomplete sexual dimorphism. Given the evidence in this species for female reproductive costs associated with ornamentation, this sex-nonspecific regulation of an honest signal may underlie intralocus sexual conflict.Item How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model(Wiley, 2015) Boulton, Kay; Couto, Elsa; Grimmer, Andrew J.; Earley, Ryan L.; Canario, Adelino V. M.; Wilson, Alastair J.; Walling, Craig A.; University of Edinburgh; Universidade do Algarve; University of Exeter; University of Alabama TuscaloosaIt is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive-proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy-bold) or coping style (reactive-proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive-reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling periods) of glucocorticoid traits are used in ecological or evolutionary studies focussed at the individual level.Item Lower-limb robotic devices: controls and design(University of Alabama Libraries, 2012) Wu, Sai Kit; Shen, Xiangrong; University of Alabama TuscaloosaLower limb robotic devices, like prostheses and orthosis, are required to work closely with human limbs, and thus an effective control framework and reliable design are both critical. This dissertation presents novel methods to control a DC powered knee prosthesis, a pneumatic prosthesis, and the progress of controlling a multifunctional orthosis. Moreover, this dissertation also presents a novel pneumatic knee prosthesis design. A novel high-level controller controls the DC powered knee prosthesis by utilizing the Electromyography (EMG) with biomechanical model. The controller combines an active control component that reflects the wearer's motion intention, with a reactive control component that implements the controllable impedance critical to the safe and stable interaction. The effectiveness of the proposed control approach is demonstrated through the experimental results for arbitrary free swing and level walking. A sliding mode low-level controller is applied to control the pneumatic prosthesis to overcome the highly nonlinearity from the properties of pneumatic muscle and the design of prosthesis. The effectiveness of the controller is demonstrated though experiments. The progress of making a complete control algorithm for a multifunctional orthosis consists of two major parts. One is the user movement classification methods. There are a total of three classifiers: the walk-to-stop classifier, the speed-changing classifier, and the movement start classifier, which includes climbing up a stair, climbing down a stair and level walking. The classification rate of all three qualifiers is 90% or more. The second major part of the research is high-level controllers for different functions. A high-level fuzzy impedance controller, which increases the flexibility of a regular impedance controller, has been developed for speed adaptive walking control. The effectiveness of the controller is demonstrated through simulation. A novel knee prosthesis design which utilizes the rope pulley mechanism and slider crank mechanism. In the pulley design for the rope pulley mechanism, a superellipse pulley is chosen to give more variation. The parameters in those mechanisms and the prosthesis are optimized, so that the knee torque from the prosthesis is close to that in a biological leg. The design also reserves space for the components of an ankle prosthesis.Item Microevolutionary Distribution of Isogenicity in a Self-fertilizing Fish (Kryptolebias marmoratus) in the Florida Keys(Oxford University Press, 2012) Tatarenkov, Andrey; Earley, Ryan L.; Taylor, D. Scott; Avise, John C.; University of California Irvine; University of Alabama TuscaloosaThe mangrove rivulus Kryptolebias marmoratus and a closely related species are the world's only vertebrates that routinely self-fertilize. Such uniqueness presents a model for understanding why this reproductive mode, common in plants and invertebrates, is so rare in vertebrates. A survey of 32 highly polymorphic loci in > 200 specimens of mangrove rivulus from multiple locales in the Florida Keys, USA, revealed extensive population-genetic structure on microspatial and micro-temporal scales. Observed heterozygosities were severely constrained, as expected for a hermaphroditic species with a mixed-mating system and low rates of outcrossing. Despite the pronounced population structure and the implied restrictions on effective gene flow, isogenicity (genetic identity across individuals) within and among local inbred populations was surprisingly low even after factoring out probable de novo mutations. Results indicate that neither frequent bottlenecks nor directional genetic adaptation to local environmental conditions were the primary driving forces impacting multilocus population-genetic architecture in this self-fertilizing vertebrate species. On the other hand, a high diversity of isogenic lineages within relatively small and isolated local populations is consistent with the action of diversifying selection driven by the extreme spatio-temporal environmental variability that is characteristic of mangrove habitats.Item Mississippian kinship and the organization of the Koger's Island cemetery(University of Alabama Libraries, 2014) Wix, Elizabeth Grant Wilson; Knight, Vernon J.; University of Alabama TuscaloosaThe assumption that Mississippian societies were matrilineal and exogamous has not been tested. This pattern of kin group organization may be examined archaeologically through biodistance studies of cranial and dental remains. This study focuses on the Mississippian cemetery of Koger's Island to determine if average genetic homogeneity within spatial groupings at Koger's Island is greater than that between groups, and further, if there is greater homogeneity among females within spatial groups than males. If confirmed, it may be inferred that kin groups were both matrilineal and exogamous. Confirming matrilineality and exogamy within this cemetery population would contribute to a growing awareness that forms of kin groups were not uniform across the Mississippian Southeast. Visually, the Koger's Island burials appear to be arranged in rows. In previous studies the burials have been compared in terms of grave goods, age, sex, and trauma, but no prior biodistance study has been conducted to determine biological relationships within the cemetery. Previous research by Peebles (1971) suggested that rows may have been delineated by factors other than kinship. Marcoux (2010), in contrast, concluded that kinship may have been an important organizing principle on the island, but that the cemetery was not arranged in discrete rows on that basis (Marcoux 2010). In, this study, biodistances were calculated for each pair of individuals by mathematically combining 211 variables using a distance metric. Four different spatial configurations were tested to see if biodistance played a role in their formation. Cluster analysis was then used to examine overall patterning within a Gower's distance matrix. Clusters of individuals were predicted to fall into distinct spatial groups, indicating that individuals were interred with biological kin. Also, females within clusters were predicted to have greater homogeneity than males indicating the exogamous matrilineality expected for this Mississippian group. While clusters did not map so neatly as hypothesized, evidence was found to indicate that a biological component played some role in the Koger's Island cemetery burial organization.Item Monitoring heart rate variability in elite college football players throughout the preparatory and competitive season(University of Alabama Libraries, 2017) Flatt, Andrew A.; Esco, Michael R.; University of Alabama TuscaloosaVagally-mediated heart rate variability (lnRMSSD) reflects cardiac-parasympathetic modulation and may be a useful marker for reflecting recovery status and training adaptation in football players. Three studies were conducted to evaluate lnRMSSD responses to training based on playing position (SKILL, MID-SKILL and LINEMEN) among an elite college football team during three distinct phases of training including the off-season (Spring camp), preseason camp and the in-season competitive period. The first study evaluated daily and chronic lnRMSSD responses to training during Spring camp. Following ~20 h of recovery from a football practice, a significant reduction in lnRMSSD for LINEMEN was observed, while lnRMSSD for SKILL and MID-SKILL returned to near or within baseline values. Individual changes in lnRMSSD from baseline to 20 h post-training were significantly related to body mass with greater lnRMSSD reductions occurring among heavier players and vice versa. Chronic responses showed that individual coefficient of variation of lnRMSSD derived from the entire 4-week Spring camp was significantly inversely related to individual mean training load after adjusting for body mass. The second study evaluated daily lnRMSSD and perceived wellness responses to a 13-day intensive preseason training camp in hot and humid conditions. After the first few days of training, decrements in lnWellness and increases in lnRMSSD, peaking on Day 12 following a day of passive rest among SKILL and LINEMEN were observed. The peak in lnRMSSD was associated with the return of lnWellness to Day 1 values. MID-SKILL showed no meaningful changes in lnRMSSD while their lnWellness remained chronically suppressed throughout the duration of preseason camp. The third study evaluated the daily lnRMSSD response to the most intense training session of the week across three separate weeks during the first month of the competitive season. Compared to resting values, lnRMSSD ~20 h following training was significantly reduced for LINEMEN and MID-SKILL but not for SKILL. The individual change in lnRMSSD from rest to 20 h post training was significantly related to both body mass and training load. In conclusion, the lnRMSSD response to training among elite football players depends on playing position, body mass, training load and training phase. Subjects with greater body mass and lower mean training loads tend to show the largest reductions in lnRMSSD while subjects with lower body mass and higher mean training loads tend to show smaller daily changes in lnRMSSD. While these lnRMSSD responses to training were consistent during Spring camp and during the early in-season competitive phase, this trend was obscured during preseason training in hot and humid conditions. Rather than decreasing with accumulated fatigue, lnRMSSD tended to increase. Thus, heat acclimatization responses during preseason camp may prevent typical training-induced reductions in lnRMSSD observed during Spring camp and in-season.Item Natural hybridization between divergent lineages in a selfing hermaphroditic fish(Royal Society of London, 2018) Tatarenkov, Andrey; Earley, Ryan L.; Taylor, D. Scott; Davis, William P.; Avise, John C.; University of California Irvine; University of Alabama TuscaloosaBy definition, mating between individuals is infrequent in highly selfing organisms, and so too, therefore, hybridization should be rare between genetically divergent lineages in predominantly self-fertilizing species. Notwithstanding these expectations, here we report a remarkable case of natural hybridization between highly diverged phylogeographic lineages of the mangrove rivulus, a small killifish that reproduces predominantly by self-fertilization and typically is found as highly homozygous lines in most parts of its extensive geographical range. Two distinctive genetic lineages (Kryptolebias marmoratus and a 'Central clade' closely related to K. hermaphroditus) previously were not known in sympatry, but were found by us to co-occur on San Salvador, Bahamas. Genetic analyses of a mitochondrial and multiple nuclear markers determined the direction of a cross producing a hybrid fish. Furthermore, we show that this hybrid individual was viable, as it successfully reproduced by self-fertilization for two generations. Additional sampling of this population will be necessary to determine if backcrossing of hybrids to the parental lineages occurs in nature and to analyse whether such backcross progeny are viable. Application of the biological species concept (BSC) is traditionally difficult in clonally reproducing organisms. Our results show that although mangrove rivulus fish are mostly highly selfing in nature (resulting in isogenic, effectively clonal and homozygous progeny), classification within this taxonomic complex need not be incompatible with the BSC.