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Pre-Session Pairing and Instructional Fading Prior to Instruction
Get PDFGiven that instructional demands can become aversive with children with ASD, pairing is an effective tool used to decrease problematic behaviors. Previous research has evaluated the effect of antecedent manipulations strategies such as pre-session pairing. Pairing the therapist and teaching environment with highly preferred items can decrease problematic behaviors during instruction. Pre-session pairing and instructional fading might aid in not only decreasing those behaviors but increasing overall responding. Two participants with ASD and ADHD were included in the following study. These participants progressed through 8 stages of pairing and instructional fading. Problem behavior decreased from baseline for both participants in the post-pairing stage
The regulation of stress steroid release in freshwater turtles
Get PDFThe goal of this study is to characterize the Hypothalamic-Pituitary-Adrenal (HPA) axis regulators of the stress response in a turtle species, the Red-Eared slider, Trachemys scripta elegans and to determine if NPY acts as a secretagogue for adrenal steroids in reptilian species, as it does in mammals. Here, I caught turtles using baited hoop traps. Then, I used pharmacological injections of ACTH (intermediate in HPA axis), dexamethasone (DEX, a synthetic steroid that blocks ACTH release and induces HPA negative feedback), NPY (starvation hormone), and NPY receptor agonists. Each turtle received a single injection upon capture, and I recorded whether adrenal steroid secretion is stimulated or decreased due to negative feedback. The measured changes in adrenal secretion suggested two specific conclusions: 1) A novel connection between the starvation and stress response 2) There may be two independent pathways for stress hormone synthesi
Synthesis and Evaluation of Novel Tyrosinase Inhibitors
Get PDFMelanin is responsible for the protection against ultraviolet light and the pigmentation of mammalian skin, hair, and eyes.1–3 This indolic polymer is located in the epidermis of mammals and is produced through melanogenesis in specialized cells called melanocytes. Over production of melanin in humans can produce unwanted aesthetic products such as dark spots, freckles, solar lentigo (age spots), melasma, and even cancer.2,4,5 The overproduction of melanin during post-harvest handling causes enzymatic browning of produce resulting in a loss of nutritional value, a decrease in shelf life, and a decline flavor.2,6–8 Tyrosinase is an oxidoreductase, type-3, copper-containing glycoprotein located in the membrane of a melanosome. This enzyme catalyzes three steps in the production of melanin, one of which is the rate limiting step of the biosynthetic process.9,10 Melanogenesis, is initiated by the oxidation of L-tyrosine (monophenol) and/or dopaquinone/L-DOPA (diphenol) to dopaquinone by the key enzyme tyrosinase. 1,11Through the inhibition and regulation of tyrosinase, a crucial enzyme in the process of melanogenesis, pharmaceutical, cosmetic, and agricultural industries are developing inhibitory mechanisms to modulate the production and concentration of melanin with hopes to combat the effects of browning in the skin of humans and produce alike. Currently the disruption of melanogenesis through the synthetic or natural inhibition of tyrosinase is the most popular approach. Thalassotalic acid A-C, a series of natural products isolated from the marine bacterium Thalassotalea in 2016, was shown to have high inhibitory activity against tyrosinase compared to popular inhibitors such as kojic acid, arbutin, aloesin, and hydroquinone.8 This research hopes to further optimize and evaluate Thalassotalic acid A by synthesizing analogues with metal chelating and hydrophobic groups, properties that are known to have high inhibitory rates against mushroom and human tyrosinase