Woo J.,Davis College |
Park E.,University of California at Davis |
Dinesh-Kumar S.P.,Davis College
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014
Autophagy is a highly conserved biological process during which double membrane bound autophagosomes carry intracellular cargo material to the vacuole or lysosome for degradation and/or recycling. Autophagosome biogenesis requires Autophagy 4 (Atg4) cysteine protease-mediated processing of ubiquitin-like Atg8 proteins. Unlike single Atg4 and Atg8 genes in yeast, the Arabidopsis genome contains two Atg4 (AtAtg4a and AtAtg4b) and nine Atg8 (AtAtg8aAtAtg8i) genes. However, we know very little about specificity of different AtAtg4s for processing of different AtAtg8s. Here, we describe a unique bioluminescence resonance energy transfer-based AtAtg8 synthetic substrate to assess AtAtg4 activity in vitro and in vivo. In addition, we developed a unique native gel assay of superhRLUC catalytic activity assay to monitor cleavage of AtAtg8s in vitro. Our results indicate that AtAtg4a is the predominant protease and that it processes AtAtg8a, AtAtg8c, AtAtg8d, and AtAtg8i better than AtAtg4b in vitro. In addition, kinetic analyses indicate that although both AtAtg4s have similar substrate affinity, AtAtg4a is more active than AtAtg4b in vitro. Activity of AtAtg4s is reversibly inhibited in vitro by reactive oxygen species such as H2O2. Our in vivo bioluminescence resonance energy transfer analyses in Arabidopsis transgenic plants indicate that the AtAtg8 synthetic substrate is efficiently processed and this is AtAtg4 dependent. These results indicate that the synthetic AtAtg8 substrate is used efficiently in the biogenesis of autophagosomes in vivo. Transgenic Arabidopsis plants expressing the AtAtg8 synthetic substrate will be a valuable tool to dissect autophagy processes and the role of autophagy during different biological processes in plants.
Sohler N.L.,Davis College |
Jerant A.,University of California at Davis |
Franks P.,University of California at Davis
Patient Education and Counseling | Year: 2015
Objective: CRC screening interventions tailored to the Expanded Health Belief Model (EHBM) socio-psychological factors have been developed, but the contributions of individual factors to screening outcomes are unclear. Methods: In observational analyses of data from a randomized intervention trial, we examined the independent associations of five EHBM factors - CRC screening knowledge, self-efficacy, stage of readiness, barriers, and discussion with a provider - with objectively measured CRC screening after one year. Results: When all five factors were added simultaneously to a base model including other patient and visit characteristics, three of the factors were associated with CRC screening: self-efficacy (OR = 1.32, p = 0.001), readiness (OR = 2.72, p<. 0.001), and discussion of screening with a provider (OR = 1.59, p = 0.009). Knowledge and barriers were not independently associated with screening. Adding the five socio-psychological factors to the base model improved prediction of CRC screening (area under the curve) by 7.7%. Conclusion: Patient CRC screening self-efficacy, readiness, and discussion with a provider each independently predicted subsequent screening. Practice implications: Self-efficacy and readiness measures might be helpful in parsimoniously predicting which patients are most likely to engage in CRC screening. The importance of screening discussion with a provider suggests the potential value of augmenting patient-focused EHBM-tailored interventions with provider-focused elements. © 2015 Elsevier Ireland Ltd.
Hanson M.L.,West Virginia University |
Brundage K.M.,West Virginia University |
Schafer R.,West Virginia University |
Tou J.C.,Davis College |
Barnett J.B.,West Virginia University
Toxicology and Applied Pharmacology | Year: 2010
Cadmium (Cd) is both an environmental pollutant and a component of cigarette smoke. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports in the literature of immunomodulatory effects of prenatal exposure to Cd. The sonic hedgehog (Shh) and Wnt/β-catenin pathways are required for thymocyte maturation. Several studies have demonstrated that Cd exposure affects these pathways in different organ systems. This study was designed to investigate the effect of prenatal Cd exposure on thymocyte development, and to determine if these effects were linked to dysregulation of Shh and Wnt/β-catenin pathways. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose (10 ppm) of Cd throughout pregnancy and effects on the thymus were assessed on the day of birth. Thymocyte phenotype was determined by flow cytometry. A Gli:luciferase reporter cell line was used to measure Shh signaling. Transcription of target genes and translation of key components of both signaling pathways were assessed using real-time RT-PCR and western blot, respectively. Prenatal Cd exposure increased the number of CD4+ cells and a subpopulation of double-negative cells (DN; CD4-CD8-), DN4 (CD44-CD25-). Shh and Wnt/β-catenin signaling were both decreased in the thymus. Target genes of Shh (Patched1 and Gli1) and Wnt/β-catenin (c-fos, and c-myc) were affected differentially among thymocyte subpopulations. These findings suggest that prenatal exposure to Cd dysregulates two signaling pathways in the thymus, resulting in altered thymocyte development. © 2009 Elsevier Inc. All rights reserved.
Mendez R.,Wayne State University |
Zheng Z.,Wayne State University |
Fan Z.,Peking Union Medical College |
Rajagopalan S.,Davis College |
And 3 more authors.
American Journal of Translational Research | Year: 2013
Recent epidemiological studies have suggested a link between exposure to ambient air-pollution and susceptibility to metabolic disorders such as Type II diabetes mellitus. Previously, we provided evidence that both short- and long-term exposure to concentrated ambient particulate matter with aerodynamic diameter <2.5 μm (PM2.5) induces multiple abnormalities associated with the pathogenesis of Type II diabetes mellitus, including insulin resistance, visceral adipose inflammation, brown adipose mitochondrial adipose changes, and hepatic endoplasmic reticulum (ER) stress. In this report, we show that chronic inhalation exposure to PM2.5 (10 months exposure) induces macrophage infiltration and Unfolded Protein Response (UPR), an intracellular stress signaling that regulates cell metabolism and survival, in mouse white adipose tissue in vivo. Gene expression studies suggested that PM2.5 exposure induces two distinct UPR signaling pathways mediated through the UPR transducer inositol-requiring 1α (IRE1α): 1) ER-associated Degradation (ERAD) of unfolded or misfolded proteins, and 2) Regulated IRE1-dependent Decay (RIDD) of mRNAs. Along with the induction of the UPR pathways and macrophage infiltration, expression of genes involved in lipogenesis, adipocyte differentiation, and lipid droplet formation was increased in the adipose tissue of the mice exposed to PM2.5. In vitro study confirmed that PM2.5 can trigger phosphorylation of the UPR transducer IRE1α and activation of macrophages. These results provide novel insights into PM2.5-triggered cell stress response in adipose tissue and increase our understanding of pathophysiological effects of particulate air pollution on the development of metabolic disorders.
News Article | September 28, 2016
It’s a new era for the solar industry. Today, technology innovation extends well beyond the solar panel to the entire system, which companies like SunPower believe is key to helping solar become a leading energy source. Last week, SunPower launched its third-generation Oasis platform for large-scale solar projects at the company’s new research and development facility in Davis, California. The latest iteration features advanced design tools, drones, robots and new agriculture practices that aim to improve project performance from site development through to operations and maintenance. “Right now, as we’re seeing [power-purchase agreement] rates fall, we really need to look at every detail in the system and find a way to optimize everything,” said Matt Campbell, vice president of power plant products for SunPower. More than 700 megawatts' worth of new Oasis platform projects have already been awarded, with construction starting in North America and China within the coming weeks. In 2017, all new SunPower solar plants will be built using the third-generation Oasis platform. “SunPower Oasis allows customers to generate more value from a broader selection of potential power-plant sites, at an accelerated pace,” said Tom Werner, SunPower president and CEO. “An Oasis solar power plant may be designed 90 percent faster than the time required to design conventional solar power plants. While flat, rectangular-shaped sites are required for other trackers on the market, Oasis can take advantage of unused, irregularly shaped areas and slopes up to 10 degrees to generate up to 60 percent more energy than conventional technology installed at the same site.” Each additional 10 acres of usable land on a given project site represents 2 to 4 more megawatts of power, Werner said. Therefore, the ability to maximize the use of a site can significantly impact a project’s bottom line, and help the large-scale solar sector grow as premium space becomes constrained. The next-generation Oasis platform includes SunPower’s new global energy optimization (GEO) system that automates project design using drones and proprietary software, developed with support from the Department of Energy’s SunShot Initiative. The drone is flown over a potential project site, collects images, and feeds those images into a cloud-based software system that comes up with dozens of site-design options. The platform allows developers to screen a large number of sites quickly, and allows owners to ensure their projects have been optimized to meet their financial and energy targets. “The drone is really just an imaging tool,” said Campbell. “The key is the software that was developed by SunPower, which takes the images, crosses them in our cloud servers, creates a three-dimensional map, and then the software comes in and proposes hundreds of layouts to optimize for capacity or financial return.” While the software is the secret sauce, the drones play a pivotal role. Drones not only help with project design, but they can also be used to track site production. Instead of sending expensive project managers out to a site, the drone uses a remote monitoring management tool to track progress and an infrared imaging system to detect any issues. All of that data is fed into the GEO system to ensure project deployment is smooth and speedy. Once built, robots used in the third-generation Oasis platform will be able to clean soiled panels using 75 percent less water than manual cleaning methods and operate at night to avoid interfering with daytime energy production. The robots were initially developed by Greenbotics, which SunPower acquired in 2013, and developed further with SunShot support. SunPower’s next-generation robotics cleaning technology is expected to be able to clean 10 megawatts' worth of panels in 10 hours with just three workers and a pickup truck. The pace is twice as fast as the company’s current robotic cleaning technology, and 10 times faster than competing manual cleaning methods. “It may not sound like that big of a deal, but as the cost of solar energy comes down for ground-mounted systems, the percentage of the costs of operations and maintenances goes up,” said Werner. “It can be as high as 15 percent [of the overall system cost], so having robots to clean the system is a huge deal.” With equipment costs falling and land constraints increasing, innovative solutions are needed to bring the solar sector meaningfully beyond 1 percent of U.S. energy generation. “A lot of the beginning of the solar industry was focused on the panel,” said Campbell. “Now we're looking at innovation all around the rest of the system. That's why we're always surveying new technology -- whether it's a robot, whether it's a drone, whether it's software -- and saying, ‘How can this help us reduce the cost of solar, build projects faster, and make them more reliable?’” Another element of SunPower’s new Oasis product is the redesigned tracker system, which will help to overcome concerns about land use. The next-generation Oasis trackers are unlinked, shorter and wider, which allows for plants to be built on slopes that were previously considered unsuitable for development. SunPower claims its systems can be built on gradients up to 10 degrees, compared to the 6-degree gradient limit for most of its competitors. Shortening the tracker row length from roughly 90 meters to 45 meters also makes the design more compatible with different location types. Each tracker is now also twice as wide with twice as many panels, which allows a single piece of infrastructure to produce more energy, while reducing the number of parts by roughly half. As part of the new integrated design, there are no combiner boxes, cable trays, motor batteries or other parts that can cause failure. Fewer parts are expected to translate to faster assembly time in the field and cheaper maintenance. In the past, the two-panel design wasn’t considered viable because wider arrays catch more wind. But SunPower insists wind issues have been completely overcome. “Doubling the number of panels so I can reduce the part count by 50 percent is really hard to do, but that’s what the SunPower design team has done,” said Werner. In addition, each Oasis tracker row now has an on-board actuator that uses real-time information on voltage and current to inform how the row is controlled, optimizing for performance. This is a departure from previous SunPower products that tracked the sun using GPS. SunPower is not the first company to deploy an unlinked architecture, but it claims to have the first fully integrated design. “We're taking a holistic view,” said Campbell. “We're the only ones in the world that cover the full spread of the power plant, from finding land through the long-term operation. I think in the future, this integrated approach will provide a lot of value.” While SunPower's insight into the entire solar value chain is considered to be an advantage, Werner added that the company also plans to forge strategic partnerships to accelerate sales internationally and recover from a poor second-quarter performance. As an example, SunPower plans to leverage its relationship with owner Total to deploy large-scale solar projects in Africa. "[A company] cannot afford to develop solar projects all over the world, so you have to partner more, and decide where you're going to develop, and where you spend money," said Werner. "I think this is the time for focusing, and also a separation of [where] the strong survive." Part of taking a holistic view means ensuring that solar power plants don’t conflict with the surrounding area, which is both an economic and environmental concern in many places. To that end, SunPower has partnered with the University of California, Davis to evaluate possible crop varieties that can coexist with large-scale, ground-mounted solar. The new Oasis design allows for multiple uses because each row is farther apart than in previous designs. And because the trackers are unlinked, there are no obstructions on the ground. In China, SunPower already built a solar farm for Apple that allows yaks to safety graze among the panels. These types of solutions will be needed all around the globe as more solar projects are deployed at gigawatt scale. “The idea of leveling a field and putting solar panels on it is less and less accepted,” said Werner. “What we would prefer is to take a field and put a solar plant on it and hardly disrupt the field…and we’re getting closer and closer to that.” The SunPower R&D Ranch -- where the company plans to test a suite of new technologies -- is currently attempting to grow tomatoes and peppers in between the Oasis arrays, but it will attempt to grow other types of crops too. Heiner Lieth, professor at the UC Davis College of Agriculture and Environmental Science, started a solar research project in 2010 and has successfully been able to grow crops in the shade of solar panels. But there’s a lot more work to be done in order to scale these solutions, he said. “I’m convinced it’s possible,” said Lieth. “The question is what the ideal balances are depending on what you’re going to be using for your cropping systems and what the market is for your electricity and agricultural products. And it opens up a whole world of questions.” Tomatoes probably aren’t the ideal crop to try to grow right off the bat, he said. Conventional rectangular solar panels probably aren’t the best solution, either. If solar is to become the dominant power source in the U.S. and abroad, it will have to learn how to coexist with agriculture and animals out of pure necessity, Lieth said. And in order to coexist, solar projects will likely need to be designed differently. “I think it’s a huge opportunity for everybody in the field, and to me, it’s a real surprise nobody has thought outside the box,” Lieth said.
News Article | December 20, 2016
A new study from Keith Baar's Functional Molecular Biology Laboratory at the UC Davis College of Biological Sciences and the Australian Institute of Sport suggests that consuming a gelatin supplement, plus a burst of intensive exercise, can help build ligaments, tendons and bones. The study is published in the January issue of the American Journal of Clinical Nutrition. Connective tissue and bone injuries are common in both athletes and the elderly, and interfere with peoples' ability (and enthusiasm) for exercise, whether they are an elite athlete or just trying to lose weight and maintain fitness and flexibility. Steps that can prevent injury and enhance recovery are therefore of great interest. Obviously, it's difficult to assess the direct effect of a supplement on tissues without opening up someone's knee. But Baar's laboratory has been developing techniques to grow artificial ligaments in the laboratory. They used their lab-dish ligaments as a stand-in for the real thing. Baar, Greg Shaw at the Australian Institute of Sport, and colleagues enrolled eight health young men in a trial of a gelatin supplement enhanced with vitamin C. The volunteers drank the supplement and had blood taken, and after one hour performed a short (five minute) bout of high-impact exercise (skipping). The researchers tested the blood for amino acids that could build up the collagen protein that composes tendons, ligaments, and bones. They also tested blood samples for their effect on Baar's lab-grown ligaments at UC Davis. The gelatin supplement increased blood levels of amino acids and markers linked to collagen synthesis, and improved the mechanics of the engineered lab-grown ligaments, they found. "These data suggest that adding gelatin and vitamin C to an intermittent exercise program could play a beneficial role in injury prevention and tissue repair," the researchers wrote. Read the paper here. The work was funded by the National Institute on Aging (NIH) and the Australian Institute of Sport.
Moldovan L.,Davis Heart and Lung Research Institute |
Batte K.,Davis Heart and Lung Research Institute |
Wang Y.,Davis Heart and Lung Research Institute |
Wisler J.,Davis College |
Piper M.,Davis Heart and Lung Research Institute
Methods in Molecular Biology | Year: 2013
Small extracellular vesicles are released from both healthy and disease cells to facilitate cellular communication. They have a wide variety of names including exosomes, microvesicles and microparticles. Depending on their size, very small extracellular vesicles originating from the endocytic pathway have been called exosomes and in some cases nanovesicles. Collectively, extracellular vesicles are important mediators of a wide variety of functions including immune cell development and homeostasis. Encapsulated in the extracellular vesicles are proteins and nucleic acids including mRNA and microRNA molecules. MicroRNAs are small, non-coding RNA molecules implicated in the post-transcriptional control of gene expression that have emerged as important regulatory molecules and are involved in disease pathogenesis including cancer. In some diseases, not only does the quantity and the subpopulations of extracellular vesicles change in the peripheral blood but also microRNAs. Here, we described the analysis of peripheral blood extracellular vesicles by flow cytometry and the RNA extraction from extracellular vesicles isolated from the plasma or serum to profile microRNA expression. © Springer Science+Business Media New York 2013.
News Article | December 9, 2016
Too much of the advice provided to millennials is the same message, recycled. They need to follow their passion, do what they love, travel the world, and live in the moment. Not surprisingly, many of these same millennials end up let down by normal jobs. They dream of a fantasy life, rather than learning how to make the most of reality. To help solve this problem Kate Athmer and Rob Johnson, two Philadelphia-based millennial executives, have put together the tools, tips, and tricks to bridge the communication gaps between different generational workplace mentalities in their new book, Millennial Reboot: Our Generation's Playbook for Professional Growth. For millennials looking to balance their ideals with the demands of corporate culture, Millennial Reboot provides a guide to: Several business leaders have commented on the benefit of reading and applying the knowledge conveyed in Millennial Reboot. Scott Vaughan, the CMO at Integrate, described the book: "A new generation of professionals are entering the workforce and our communities with a very different view of the world. Kate and Rob - who have walked in their shoes - bring their real-world guidance and a playbook for the Millennial generation who will soon comprise the large majority of our workforce.” It is also being acclaimed by the academic world. A message from Neil Sullivan, University of Dayton’s athletic director: “Millennials: Read this book!” Millennial Reboot, published by Lioncrest Publishing, is available on Amazon in Kindle and paperback versions. Kate Athmer runs demand marketing for a software start-up, advocating regularly for technology to enable advanced strategies. As a cofounder of GreenLit Consulting, she also provides career and brand advice for peers, recent graduates, and anyone looking to advance. A graduate of the University of Dayton with an MBA from the University of Tennessee, Kate credits a combination of strong mentors, diverse educational and athletic opportunities, tenacity, and strategic content consumption for her success in the workplace. Rob Johnson has experience as a sports and entertainment executive, collegiate rowing coach, and adjunct professor. He is driven by creativity and innovation, which he puts to practice as a cofounder of GreenLit Consulting. Rob has grown his career in part by bridging the technology divide and committing to the professional development of others. A native of Margate, New Jersey, graduate of Marietta College and avid rower, Rob began his professional career as the Marketing Coordinator for the Jacksonville Jaguars (NFL). While in Jacksonville, he earned his MBA from the Davis College of Business at Jacksonville University.
Beitel D.,Davis College
91st International School of Hydrocarbon Measurements, ISHM 2016 | Year: 2016
Understanding and evaluation of the fundamental cause and effect relationships with the liquid to be measured will lead to a volume determination that most closely matches the "true" volume at the referenced "standard" pressure and temperature.
Beitel D.,Davis College
Proceedings of the 90th International School of Hydrocarbon Measurement, ISHM 2015 | Year: 2015
Understanding and evaluation of the fundamental cause and effect relationships with the liquid to be measured will lead to a volume determination that most closely matches the "true" volume at the referenced "standard" pressure and temperature. As defined by GPA Standard 8182-03, API MPMS 14.7, Mass Measurement Techniques are used for fluids in the 0.35