This study involved the examination of parental beliefs and practices about early literacy and language and how they influence observed literacy behaviors of their 18-36 month old toddlers. Observed literacy behaviors of the toddlers included phonological awareness (PA) and written language awareness (WLA). The objectives of this study were to (a) characterize the emergent literacy behaviors of toddlers, (b) characterize parental beliefs and practices regarding emergent literacy with respect to toddlers, and (c) determine the relationship between toddlers’ emergent literacy behaviors and their parents’ beliefs and behaviors. Participants included 15 mother-toddler dyads. Mean age of mothers was 35.2 years (SD = 4.0). All mothers qualified as middle- upper socioeconomic status according to Hollingshead (1975). Toddlers were typically developing with a mean age of 26.74 months (SD = 5.3). Quantitative and qualitative methods were used to collect and analyze data. Main data collection measures included: (a) home literacy environment observation; (b) shared reading observations; and (c) parent questionnaire. Data from these measures were coded and organized into emergent literacy domains PA & WLA. Based on pilot findings, only one PA category (i.e., rhyming) was used. Four main WLA categories were used: (a) book conventions; (b) print conventions; (c) letter knowledge; and (d) story grammar. Characteristics of child-directed speech from shared reading interactions were analyzed. These characteristics included: (a) topic initiating utterances; (b) conversation eliciting utterances; (c) behavior directing utterances; (d) mean length of utterance; (e) rate; and (f) length of turn. Results indicated that these mothers engaged in several emergent literacy and language practices with their toddlers. Some of these behaviors were correlated with the observable emergent literacy skills of their children. For example, book convention behaviors of parents were moderately correlated with letter knowledge behaviors of toddlers (r = .549, p = .017). Letter knowledge behaviors of parents were moderately correlated with letter knowledge behaviors of toddlers (r = .524, p = .023). Additionally, length of turn for mothers was moderately correlated with print conventions behaviors of toddlers (r = .618, p = .007). These and other findings will be discussed in regards to their implications for early intervention practices.

With temperatures rising globally, assessing the possible impacts of the changing climate becomes more and more urgent. Ectotherms are excellent indicators of potential climatic ramifications on biodiversity because of their heavy reliance on the environment for their thermoregulation. Studies have historically looked at thermal tolerance values to establish predictive models for population and species extinctions. In chapter 1, we looked at recent studies that suggest that thermal tolerance may be a plastic trait and test the effects empirically. Most studies are based on captive lizards acclimated to laboratory conditions that do not necessarily reflect natural environments, and if thermal tolerance is plastic and affected by the recent thermal history of the animal, then the data may not be accurate. We tested the critical thermal maximum of the western fence lizard, Sceloporus occidentalis, in all four seasons, both under field (same-day) and short (two-day) lab-acclimated conditions. We found that thermal tolerance varied seasonally, with the lowest values in the summer in both same-day and two-day acclimated lizards. Additionally, we found that the thermal tolerance of lizards tested on the same day was higher in spring than in fall, but two days of acclimation to lab conditions eliminated this difference. We also tested the thermal tolerance of lizards housed at several constant acclimation temperatures for one or three weeks and compared these values to those of lizards housed in a terrarium allowing thermoregulation, and to same-day lizards. While the thermal tolerance of all lab-acclimated lizards was higher than that of same-day lizards, there was no significant difference in thermal tolerance among any of the acclimation treatments. Overall, our results show that thermal tolerance may be plastic in some situations in S. occidentalis, but that this species overall shows little plasticity in response to acclimation. In chapter 2, we evaluated the thermal environment of S.occidentalis using operative temperature models. Using operative temperature models combined with field lizard body temperatures and a lab-determined selected body temperature range, we evaluated the thermal environment of Sceloporus occidentalis to identify habitat quality, thermoregulatory effectiveness, and thermal exploitation index. Additionally, we used two predictive climate change models at a 1°C and 2°C increase to project the potential changes in habitat quality in the future. The thermal quality was highest for shady microhabitats, lowest for sunny microhabitats, and intermediate for mixed sunny/shady microhabitats. S. occidentalis were able to maintain their body temperatures in their Tset range for 6 hours, indicating the ability to exploit multiple microhabitats. Neither climate change scenario (1°C or 2°C increase) placed S. occidentalis at risk of extinction, likely because the coastal field site has a relatively mild climate. However, both scenarios greatly decreased the thermal quality of the environment, causing S. occidentalis to lose up to 2.5 hours of activity time per day. This highlights that even animals that inhabit mild climates are likely to experience sub-lethal effects of climate change.

Upon exposure to environmental stressors, amphibians such as Plethodon montanus will release corticosterone (CORT) thus causing a behavioral and physiological response to cope with the stress. Currently, there are several invasive ways of collecting CORT in salamanders. However, these techniques typically require euthanasia of the organism. We hypothesized that exposure of P. montanus to stressful handling conditions will result in elevations of CORT that can be detected through dermal swabbing. To test this, two experiments were conducted which involved swabbing the dorsal side of the trunk before and immediately after exposing P. montanus to two different environmental stressors. The first experiment involved placing P. montanus into a behavioral chamber for twelve hours while the second experiment involved restraining P. montanus in a plastic bag with a damp paper towel for ten minutes. While both experiments indicated an elevation in CORT after the respective treatments, between-replicate variability were high, and the differences were not statistically significant. The results of the first experiment did reveal a stress response when P. montanus were taken out of the chamber. The second experiment’s results also suggested that P. montanus did have an acute stress response when restrained. Future studies could replicate this research, but with a larger sample size and see if the results are congruent with the data obtained in this study.

Stress can be defined as feelings of frustration or anxiety that arise when individuals face challenges that exceed their capabilities or resources. Consequences of stress generally result from a suppressed immune system and include headaches, sleep problems, and muscle pain. Music as an intervention for relieving pain has increased due to its non-invasive nature, ease of administration, low cost, and lack of adverse side effects. While prior research on music therapy and pain has primarily focused on pain related to surgery, disease, or accidents, there have been no studies to date examining the association between music therapy and stress-induced muscle pain. I have designed a study proposal to establish the relationship between music therapy and muscle pain related to stress. The proposed study will compare salivary cortisol levels, pain visual analogue scale (VAS) scores, the number of painkillers consumed, and the number of doctor visits of healthy individuals experiencing the same stressor (MCAT or GRE) over a 3 month period. One group of participants will be randomly assigned to listen to an additional 30 minutes of self-chosen calming music a day, whereas the other will not listen to any additional music. It is hypothesized that the participants that listen to the additional calming music will experience significantly lower levels of stress and therefore lower muscle pain levels than the participants that did not listen to music. This research is potentially useful for students who undergo constant stress due to the demands of college. Future studies could include whether music therapy allows students to study longer by relieving some of the muscle pain caused by stress.

Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to various levels of PO2 (21.2, 15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) at two different temperatures (25°C and 30°C) to study the effects on developmental rate and heart rate. We also measured enzyme activity and quantified DNA content of individual embryos to compare differences among the varying levels of hypoxia and temperature. Hypoxia caused a significant decline in developmental rate and caused a stage-specific decline in heart rate. Higher temperature caused an increase in the developmental rate for those embryos incubated at PO2 of 6.1 kPa and greater. Temperature had a negative effect by hindering development below a PO2 of 6.1 kPa. Total embryonic DNA content was reduced at low partial pressures (15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) of oxygen. Citrate synthase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase were all down-regulated indicating a complete lack of enzymatic metabolic compensation to combat reduced oxygen levels.

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations of several metabolites. The most notable changes in metabolite concentration in response to anoxia were the increases of lactate, alanine, GABA and succinate as well as a pronounced decrease in aspartate concentrations. However, a complete understanding of the mechanisms by which anoxia tolerance is achieved remains elusive. Further studies into the tissue specific responses of anoxia would enable greater resolution when attempting to explain changes in concentrations of metabolites both during development and in response to anoxic insult.

Hypertension is a critical public health issue worldwide, and in the United States, it is the leading cause of heart disease, stroke, and kidney failure, contributing to more than 1,100 deaths per day. It is proposed that the renal medulla combats increased blood pressure by releasing a neutral lipid from the lipid droplets of medullary interstitial cells, termed medullipin, which induces diuresis- natriuresis and vasodepression. The renal medulla is enriched with fatty acid lipid ethanolamides including the endocannabinoid anandamide (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA), along with their primary hydrolyzing enzyme fatty acid amide hydrolase (FAAH). Our lab is investigating the relationship of these lipid ethanolamides and their metabolites to medullipin. We have shown that intramedullary infusion of AEA stimulated diuresis-natriuresis without changing mean arterial pressure (MAP) in an acute surgical model using anesthetized normotensive C57BL/6J mice. The hypothesis that infusion of a FAAH-selective inhibitor, PF-3845, would produce similar responses as exogenous AEA was tested. Intramedullary infusion of PF-3845 stimulated diuresis-natriuresis, decreased MAP, and increased lipid ethanolamide concentrations in kidney tissue in C57BL/6J mice. Since the decrease in MAP observed with PF-3845 was not consistent with the results of exogenous AEA, this study hypothesized that increased PEA concentrations in the renal medulla observed with PF-3845 produced the decrease in MAP. Therefore, the effects of PEA administration into the renal medulla were investigated. Intramedullary infusion of PEA stimulated diuresis and natriuresis without changing MAP in normotensive C57BL/6J mice. However, intramedullary PEA administration to mice made hypertensive using L-NAME, an inhibitor of nitric oxide synthase, was assessed. Intramedullary infusion of PEA stimulated diuresis, but also decreased MAP in L-NAME-induced hypertensive mice. The mechanism of PEA-induced diuresis was evaluated for the contributions of its FAAH-mediated hydrolysis and the CB1 receptor. Intramedullary infusion of PEA stimulated diuresis in FAAH knockout mice and CB1 knockout mice. The possible source of PEA in the renal medulla was investigated using renal medullary interstitial cells cultured from mice. In cultured mouse medullary interstitial cells (MMICs), treatment with PF-3845 increased cytoplasmic lipid droplets detected by Sudan Black B (SBB) staining and increased PEA in the culture medium. Physiologic stimuli that may regulate PEA production and release from MMICs were also evaluated. Increased osmolarity increased NAPE-PLD protein levels, increased SBB stained droplets in MMICs, and increased PEA concentrations in the culture medium. Overall, it is concluded that the PEA-induced diuretic and natriuretic effect is independent of FAAH-mediated hydrolysis and the CB1 receptor, and that PEA can serve as an antihypertensive regulator in the renal medulla that may be regulated by medullary interstitial cells.

Poikilothermic organisms experience trade-offs associated with life at different temperatures caused by incompatible physiological and biochemical demands caused by temperature extremes. As the result many such organisms exhibit acclamatory effects, adjusting their metabolism and physiology to recently experiences temperatures. One such acclamatory effect is the metabolic compensation that allows an organism to withstand increases in temperature by decelerating biological rates below Arrhenius expectations, presumably reducing energetic demand and reducing stress. Daphnia magna is resilient across a wide temperature range, and if acclimated to mildly stressful temperatures first, exhibits longer survival in lethal temperatures. Certain genotypes of Daphnia also exhibit higher acute thermal tolerance than others, indicating the presence of genetic variation and local adaptation in heat tolerance. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (2 generations at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia (4 with high acute temperature tolerance, and 4 low). There are nonlinear decelerations of Daphnia respiratory rates across a temperature gradient when acclimated to 25°C or following short 8-hour acclimation to measurement temperatures. Furthermore, Daphnia exposed to a near-lethal temperature (35°C) with a subsequent 24-hour recovery period at their native 25°C-acclimation temperature shows no indication of respiratory damage. Genotype showed no difference in metabolic compensation, indicating the process is genetically constrained. Regulation of mitochondrial and membrane function are promising areas to further characterize the mechanism of metabolic compensation found in this study.

Poikilothermic organisms experience trade-offs by differential physiological demands generated by temperature extremes. Many such organisms exhibit acclimatory effects, adjusting their metabolism and physiology to recently experienced temperatures. One such acclimatory effect is metabolic compensation, the deceleration of biological rates below Arrhenius expectations. Daphnia magna is eurythermal, and if acclimated to mildly stressful temperatures first, survives longer in lethal temperatures. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (lifetime at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia with high or low acute temperature tolerance. There were decelerations of respiratory rates across a temperature gradient when acclimated to 25°C or following short 8- hour acclimation to measurement temperatures. Daphnia exposed to a near-lethal temperature (35°C) with a 24-hour recovery period at 25°C-acclimation temperature showed no difference in respiratory control compared to unexposed 25°C-acclimated Daphnia. Genotypes showed no difference in potential compensatory ability.

We have examined potential influences of gender, age, and nutrition on the expression of circadian locomotor activity rhythms in the flesh fly Sarcophaga crassipalpis. We found no significant differences in endogenous circadian period under constant dark conditions resulting from gender, nutrition, or age. Male and female flesh flies were predominantly diurnal under light-dark cycles, but their entrainment patterns differed. Females displayed higher activity levels and increasing activity with age, unlike males. Moreover, females exhibited an extraordinary, but transient, departure from diurnality which we characterize as “extended dark activity” (EDA), a continuous bout of locomotor activity extending three hours, or longer, into the dark phase at twice the median of the individual’s overall locomotor activity. EDA occurred as an age-dependent response to liver consumption. Our results suggest a linkage between physiological events associated with egg provisioning and locomotor activity as well as multiple influences on the expression of circadian clock-regulated behavior.