514 research outputs found
Soyasaponin and α-tomatine inhibit in vitro bioaccessibility of cholesterol
Saponins are a structurally diverse family of secondary plant metabolites that confer protection against pathogens and predators. These compounds consist of triterpene or steroidal nuclei (aglycones) covalently linked to either mono- or oligo-saccharides. In vitro and several in vivo studies have suggested that these amphipathic compounds possess anti-carcinogenic, hypo-lipemic, hypo-cholesterolemic and immuno-enhancing activities. Limited investigations indicate that saponins are poorly absorbed, but their potential impact on digestion and gut health remains unknown. We have initiated studies to compare the effects of saponins extracted from soy, tomato, chickpea, fenugreek and a commercial mixture of phytosterols (positive control) on cholesterol absorption and metabolism, as well as on interactions between microflora and the gut epithelium. Pilot studies demonstrate significant differences in the ability of equimolar concentrations of saponins from these sources to inhibit micellarization of cholesterol from a food matrix during simulated digestion with α-tomatine >> phytosterols > soyasaponin. Removal of the oligosaccharide from tomatine to generate tomatidine markedly decreased activity. Saponins from soya and tomato, as well as their aglycones, and phytosterols all slightly, but significantly, impaired transfer of cholesterol from micelles to human intestinal Caco-2 cells. These preliminary observations suggest that saponins from crops important to Ohio economic status can modulate the bioavailability of dietary cholesterol.OARDCUSDA BARD gran
Gastrointestinal activity of saponins from soy and tomato
Saponins, a structurally diverse family of secondary plant metabolites, possess anti-carcinogenic, hypolipemic, hypocholesterolemic, and immune-enhancing activities. We have initiated studies comparing the effects of saponins extracted from several sources soy and a commercial mixture of phytosterols (positive control) on GI metabolism and transport of cholesterol and on interactions between gut microbes and intestinal epithelial cells. Saponins from tomato reduced the incorporation of cholesterol into synthetic micelles by 60%, whereas other test compounds (saponins from soya, chickpea and fenugreek and phytosterols) were without effect. During simulated gastric and small intestinal digestion, saponins (90 µM) from tomato and mixed phytosterols significantly inhibited micellarization of cholesterol (14 µM) from a food matrix. Saponins from soy and tomato, as well as phytosterols, also significantly impaired the micellar transfer of cholesterol into differentiated cultures of human intestinal Caco-2 cells. Additionally, soyasaponins decreased adherence and invasion of Caco cells by Salmonella enterica. These preliminary observations suggest that saponins from crops important to Ohio’s economy may contribute to cardiovascular and gastrointestinal health.
Supported by OARDC and USDA BARD grant.
Abstract was reviewed by M. Failla, Ms. Carlson’s advisor ([email protected])OARDCUSDA BARD gran
Comprehending Climate Change in the Himalayas: An exercise in digital storytelling
This study was completed as an attempt to visualize, contextualize, and humanize the effects of climate change in the Himalayan orogen through the lens of digital storytelling. The ArcGIS software application, Story Maps, was used to create a highly visual “storytelling” webpage. It combines spatial and empirical data from across the whole Himalayan range with stories and case studies collected in eight villages of Lower Mustang, Nepal. This project is thus a union of climatologic and ethnographic research. As climate change continues to charge ahead in an incredibly vulnerable part of the world, the people of the region face the challenges of natural disasters, season unpredictability, undependable water resources, and the uncertain future of these resources. 27 interviews were conducted in eight villages of the Lower Mustang region of Nepal: Lupra, Kagbeni, Phalyak, Dhagarjun, Pigling, Tiri, Jharkot, and Chongur. The final Story Map website presents these experiences in a highly visual and interactive manner; thus, the dissemination of the resulting discussion is much more accessible and engaging than a traditional academic journal entry. The ultimate goal of this project is to act as a call to action, encouraging those who are more cushioned from the effects of climate change to be inspired to make drastic lifestyle changes on behalf of the people of Mustang and beyond
Ripple Migration and Boundary Layer Dynamics on a Natural Sand Bed
A laboratory study was conducted in a field scale flume to further examine the very near-bed dynamics in the near-shore environment using natural, non-cohesive sediments with d50 = 0.22 mm. A Particle Imaging Velocimetry (PIV) system was used to capture the dynamics of the movable ripple bed and the 2D flow field in the vertical (z) and along-tank (x) direction in 1.6 m still water depth. Two wave types were analyzed: regular waves with periods ranging from 4 s to 8 s and bimodal wave pairs with periods of 3.7 and 4.3 s. Orbital ripples developed in all wave environments with ripple wavelengths ranging from 5 to 15 cm.
Following Roth and Katz (1995), instantaneous ripple migration rates were calculated by spatially shifting subsequent bed profiles until a minimum difference was achieved. The ripple migration signature is cyclical but asymmetric, with higher amplitudes during onshore directed movement. This asymmetry leads to a net onshore migration, ranging from 0.1 to 0.6 cm/min in the wave conditions tested. The cyclic motion of the ripple field was compared to potential dominant forcing mechanisms: bed shear stress, coherent structure generation, and free-stream velocity.
Peak ripple migration rates occurred during strengthening onshore flow, which coincides with peak bed shear stresses and the onset of coherent structure formation identified with the swirling strength criteria of Zhou et al. (1999). Two estimates of bed shear stress were similar in magnitude and phase, with direction changes coincident with the bed migration. The combined sediment mobilization parameter of Foster et al. (2006) was found to be consistent with the bed migration signature. Oscillations associated with the wave groups caused periods of high suspension which were coincident with an increase in onshore migration rates. Low energy waves (period of 6 s and height of 10 cm) did not result in ripple motion.
The bed shear stress analysis from this study provides further evidence for the reliable application of the DANS bed shear stress approach taken by Rodriguez-Abudo and Foster (2014). Paired with the ripple migration rate, this analysis can be applied to sediment transport models to more accurately represent the sediment and flow dynamics along sandy beaches that experience wave dominated forcing
The (not-so) “Brave New World of International Criminal Enforcement”: The Intricacies of Multi-Jurisdictional White-Collar Investigations
We have entered a new age of international white-collar crime and are seeing the growing interdependency of the Department of Justice (DOJ) and parallel foreign agencies to conduct investigations and subsequent prosecutorial proceedings. This coordination to combat these crimes, however, has revealed a troubling question—how can enforcement agencies work effectively together if they have fundamental differences in the legal authority governing testimony-gathering and what evidence is allowed before a grand jury? The Court of Appeals for the Second Circuit, in United States v. Allen, confronted this issue directly as it overturned two indictments arising out of suspected manipulation of a global benchmark interest rate. It held that the DOJ’s derivative use of compelled testimony in American courtrooms is prohibited under the Fifth Amendment, despite that testimony being legally obtained by UK’s equivalent enforcement agency, the Financial Conduct Authority (FCA). This note does not suggest that the Second Circuit erred in its decision nor does it encourage the DOJ to forgo upholding the values set forth in the Constitution. It does, however, seek to address this apparent international problem with a comparable solution—an international solution. This note proposes a renewed look on the out-of-date approach to conducting parallel white-collar investigations. Specifically, it offers that an agreement, notably an amended Mutual Legal Assistance Treaty between the DOJ and its foreign counterparts that currently use compelled testimony, can circumvent constitutional concerns and, most importantly, foster further cooperation to fight these complex financial crimes
Science Interest and Confidence in Middle School Aged Students
In the middle school science classroom, students begin to decide whether or not they like science. This decision has long term impacts on their interests, future studies, and ultimately career goals. Further, the impact of this decision can be felt by the STEM field when fewer and fewer students are interested in pursuing jobs within the field. To explore the attitudes and confidence of these students towards science and math, the CURE survey and Math Anxiety Scale were adapted to gather data from a group of middle school students after attending a Middle School Science Day event. Through the research, we wanted to get a look at why some students lose interest in science around the time they are in middle school. At the event, students worked in groups to complete an engineering challenge and had the opportunity to see various science demonstrations. After the day’s activities, students were asked to complete the surveys. Surprisingly, our surveys displayed a lack of connection between math anxiety and science interest at the middle school level. This research will be useful to teachers at the middle school level as well as above and below, as they work to engage students in science class and make the content interesting and relevant, in addition to encouraging their students to be curious about science. Further, the research has laid groundwork for using an adapted form of the CURE survey at the middle school level
Case-in-Point Methodology: Creating a Studio-Laboratory Environment in Every Classroom
Participants will explore the unique approach of case-in-point methodology which utilizes student experiences to transform the academic space, harness failure, and process life’s challenges. Emphasis will be given to designing tasks that promote problem solving, communication, and self-reflection across all age groups and disciplines. Borrowing from best practices utilized at Harvard Business School, the University of Minnesota, and Andrews University’s Undergraduate Leadership Program, attendees will learn how to create tasks designed to make use of both the explicit and underlying issues that surface in the day-to-day lives of students and connect those issues to course content
Rev1 Protein Purification
1 in every 15-30 million nucleotides can be considered a mutation in healthy individuals. Replication of damaged DNA leads to genetic mutations. Genetic mutations lead to disorders and cancer. Rev1, a Y family polymerase, prevents minor mutations, such as abasic sites and exocyclic guanines, in the template strand from shutting down the process of replication. Our mutant Rev1, R324G/L325G, has replaced both the arginine located on nucleotide base number 324 and the leucine on nucleotide base number 325 with glycine. The arginine and leucine have more complex side chains groups with specific hydrophobic/hydrophilic properties. By replacing them with glycine, the side chains are now simplified to hydrogen. Our hypothesis is that Rev1 evicts the nucleotide from the active site and replaces it with an arginine while the leucine stabilizes the template base outside of the active site. We hypothesis that arginine and leucine side chains provide the mechanism for Rev1 to be a functional polymerase. This mutated Rev1 should be unable to perform this mechanism. Based on protocol provided by Dr. Bret Freudenthal and his associates at the University of Kansas Medical Center and the support of the Phoebe Laser Research Group led by Dr. Carlson and Dr. Grace, and the Chemistry Department at Northwestern, we have grown E. coli with wild type and mutant Rev1 and are in the process of purifying the Rev1 protein for crystallography
Middle School Students: Science Outreach, Math Anxiety, and Resiliency
When students reach Middle School level academics, it is observed that their interest in STEM decreases. There are many theories that have been tested to discover why this shift occurs, however, it is thought that Math anxiety is the main contributor to this decline. Furthermore, there have been indications suggesting that Math anxiety is closely related to Resiliency. In this study, we are interested in looking at the relationship between Math anxiety and Resiliency in Middle School students. In doing so, a science outreach day was designed to both increase Middle school student\u27s interest and attitudes interest towards STEM. The students who attended self-selected into this science day and were surveyed on current levels of Math Anxiety and Resilience. This experiment allowed students to learn and explore science in their own creative way from a physics-based approach; and is an example of baseline student assessment that teachers can conduct in a classroom. Nevertheless, the same size was too small to confirm significance and it is encouraged that more research is conducted on the matter
- …