53 research outputs found
The Effects of Aluminum Exposure on Planarian Photophobic Response to Different Wavelengths of Light
Building Skills for and Implementing Course Based Undergraduate Research Experiences (CUREs) Across an Environmental Studies Curriculum
Course Based Undergraduate Research Experiences (CUREs) are an effective method of teaching students not only content, but also critical thinking, scientific practice, and other skills beneficial to their education and success. They lower the barrier to participation in undergraduate research, thereby increasing access to entry. Thus, CUREs are especially valuable to under-performing students as they are an effective means of bridging the achievement gap. Due to the value and effectiveness of CUREs in student development, Lynn University has implemented a means by which students are exposed to CUREs and skills necessary to complete a CURE throughout the Environmental Studies major curriculum. This presentation will give a description of the curriculum and how CUREs and CURE-required skills are taught throughout the curriculum culminating in a fully independent capstone research project
Building Skills for and Implementing Course Based Undergraduate Research Experiences (CUREs) Across an Environmental Studies Curriculum
Building Skills for and Implementing Course Based Undergraduate Research Experiences (CUREs) Across an Environmental Studies Curriculum
Course Based Undergraduate Research Experiences (CUREs) are an effective method of teaching students not only content, but also critical thinking, scientific practice, and other skills beneficial to their education and success. They lower the barrier to participation in undergraduate research, thereby increasing access to entry. Thus, CUREs are especially valuable to under-performing students as they are an effective means of bridging the achievement gap. Due to the value and effectiveness of CUREs in student development, Lynn University has implemented a means by which students are exposed to CUREs and skills necessary to complete a CURE throughout the Environmental Studies major curriculum. This presentation will give a description of the curriculum and how CUREs and CURE-required skills are taught throughout the curriculum culminating in a fully independent capstone research project
Effect of Cadmium Exposure on Planarian Regeneration
Cadmium is a neurotoxic chemical widely distributed within our environments, persevering for long periods. It can be found in cigarettes, batteries, plastics, and other products used daily. Exposure to cadmium can have toxic effects, altering the balance between the production of reactive oxygen species (ROS) and the ability of cells to detoxify and repair the damage. Its accumulation can cause organ damage, cancer, respiratory and reproductive toxicity, and neurological defects. Planaria regeneration is a complex biological process that involves the activation of stem cells, called neoblasts, to regenerate lost tissues and organs. Neoblasts can divide and differentiate into various cell types, allowing planaria to rapidly regrow lost body parts, including the head and tail. Research has suggested that ROS play a critical role in this process. However, if an overproduction occurs, oxidative stress can inhibit regeneration. A trunk fragment assay will be conducted on Girardia dorotocephala to monitor the progression of head regeneration over a two-week period. This assay will be used in future work, exposing planarians to varying concentrations of cadmium chloride. Exposure to high levels of cadmium is said to inhibit blastema repair, so introducing the flatworms to an antioxidant should cause a rescuing effect and progress its regeneration. Antioxidants mitigate damages by neutralizing ROS by donating an electron to stabilize oxidative stress and enhance regenerative capacity. The study of planarian regeneration holds great promise for developing regenerative medicine approaches for humans
Calcium Ions Effect on Planaria Feeding Behavior
Calcium is important for the contraction of muscles, neurotransmission, and signaling in animals. Like other active movers, invertebrate planarian flatworms have musculature for motility. Therefore, it can be inferred that without the proper concentration of calcium ions in the water they can’t undulate or extend the pharynx, a muscular feeding structure. Planaria are generally cultured at a 0.5 g/L concentration of instant ocean sea salt (IOS), which contains calcium ion of 0.126 mM. However, there is uncertainty in the concentrations of important ions, such as calcium, which are optimal for the maintenance and homeostasis of the planaria. Previous research on water quality and planarian behavior has focused on species Schmidtea mediterranea, Dugesia japonica, and Girardia guanjuatiensis, but not Girardia dorotocephala (G. dorotocephala), the species currently cultured at Lynn University. Because other than being just readily available these species of worms haven’t undergone research in the frame of calcium ions. G. dorotocephala may require different concentrations of calcium ions than those of other relative species, an analysis of their requirements is warranted. For this experiment, we plan to specify which concentration of calcium is required for G. dorotocephala cultures. We hypothesize that G. dorotocephala requires micronutrient concentrations differing from standard IOS water, as has been observed for other species of planaria. We base this hypothesis on our observations of their feeding behavior following starvation. To conduct this experiment, we plan to assay food localization behavior under different concentrations of calcium
Tert-Butyl Hydroperoxide Stimulates Parturition-Associated Pathways in a Human Placental Cell Line.
Preterm birth is a leading cause of infant mortality and morbidity. Increased understanding of the etiology of preterm birth is needed to accelerate medical and public health interventions. Parturition is associated with markers of the damaging effects of reactive oxygen species (ROS). Whereas roles for prostaglandins, cytokines, and apoptosis in parturition have been described, the effect of ROS on these parturition pathways is unclear. Using the human placental trophoblast cell line HTR-8/SVneo, we investigated the effect of the lipophilic ROS-producing chemical tert-butyl hydroperoxide (TBHP) on trophoblast apoptosis, prostaglandin production, and cytokine release.
Exposure to TBHP stimulated significant, though modest, increases in redox- related responses including production of ROS, glutathione redox potential (Eh), reporter activity at the antioxidant response element (ARE), and expression of the antioxidant genes thioredoxin reductase 1 and glutaredoxin 2. Under our treatment conditions, TBHP significantly increased caspase 3/7 activity and decreased cell viability, indicative of apoptosis. Apoptotic responses were inhibited by the iron-chelating antioxidant, deferoxamine. Likewise, TBHP stimulated release of prostaglandin E2 (PGE2) and mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme in the prostaglandin synthetic pathway. In addition, TBHP increased release of the cytokine interleukin-6 (IL-6) and reporter activity of the proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB). Cotreatment with the PTGS inhibitor indomethacin or the antioxidants butylated hydroxyanisole (BHA) and diphenyl phenylenediamine (DPPD) blocked the TBHP-stimulated PGE2 response. Similarly, TBHP-stimulated IL-6 release was blocked by the antioxidants BHA, DPPD, and deferoxamine.
We next examined the redox-sensitive mitogen activated protein kinases (MAPKs) as an upstream pathway for the TBHP-stimulated responses. Treatment with TBHP increased phosphorylation of p38 MAPK, indicative of activation, and pretreatment with the p38 MAPK inhibitor PD169316 blocked the TBHP-stimulated increases in IL-6 as well as PGE2 and PTGS2, suggesting dependence of these responses on p38 MAPK activity.
In summary, these results suggest that exposure to an ROS-producing chemical stimulates responses in human placental cells linked to parturition. Because exposure to some environmental pollutants causes cellular ROS formation, these findings suggest a plausible mechanism that may underlie associations between pollutant exposures and increased risk for preterm birth.PhDToxicologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102346/1/kortecas_1.pd
The Effectiveness of Different Types of Sunscreen against UV Light on Escherichia coli
Ultraviolet (UV) light from the sun damages the DNA of our skin cells which could potentially lead to development of skin cancer (Mahroos, Yaar, Phillps, Bhawan, & Gilchrest, 2002). Sunscreen is used to protect our skin from this damage. The two most commonly used sunscreens are physical and chemical sunscreens. Physical sunscreens, also referred to as mineral sunscreens, work by sitting on top of your skin and reflecting UV light, whereas chemical sunscreens penetrate the skin and absorb UV light. There are many different brands of these sunscreens in the market. We hypothesized that the physical sunscreens would serve as better protection than the chemical sunscreens due to their high cost and natural ingredients. Brands that we used that represent physical sunscreens were Badger and Goddess Garden. Brands of chemical sunscreens were Aveeno, Hawaiian Tropic, and Up & Up Target Sports. All the sunscreens were creamy and had an SPF of 30. On average, the physical sunscreens were two times more expensive than chemical sunscreens. To test our hypothesis, we used the bacterium Escherichia coli (E. coli) as a model organism and exposed it to UV light while using the various sunscreens for protection. We then counted the survival rate of the E.coli colonies that were exposed. Our results demonstrated that there was no statistical significance in sunscreen protection. We concluded that physical sunscreens are not worth their price
Personal Care Products: Where are the Phthalates?
Phthalates are chemicals that are commonly used as a plasticizer in personal care products. This class of compounds is added to help prevent products from drying out. Phthalates have been shown to have potential negative impacts on reproductive organs, cause birth defects, effect the endocrine system, as well as causing other ill effects. For example, previous work found that phthalates can have an effect on the endocrine system of adolescent individuals. In an intervention study, phthalate exposure was reduced when these products were not being used. The purpose of the present study is to examine phthalate abundance in personal care products and to design an intervention study to lessen exposure.
To identify products containing phthalates, we used the Environmental Working Group’s Skin Deep cosmetic database. This database contains personal care products and their ingredients. We used the database to identify products that contain phthalates and the type of phthalates used. The most commonly used phthalate is polyethylene terephthalate, with it currently found in 610 products, with 314 of which are nail polish. There are also 12 other kinds of phthalates that are regularly used in personal care products, ranging from lipstick to sunscreen. We can see that there are still a multitude of products that contain potentially harmful phthalates. This study is the foundation to future work looking at exposure to phthalates in adult populations and assessing sources of exposure from personal care products
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