Nucleosynthesis: Stellar and Solar Abundances and Atomic Data

Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy -- the progenitors of the halo stars -- responsible for neutron-capture synthesis. Comparisons of abundance trends can be used to understand the chemical evolution of the Galaxy and the nature of heavy element nucleosynthesis. In addition age determinations, based upon long-lived radioactive nuclei abundances, can now be obtained. These stellar abundance determinations depend critically upon atomic data. Improved laboratory transition probabilities have been recently obtained for a number of elements. These new gf values have been used to greatly refine the abundances of neutron-capture elemental abundances in the solar photosphere and in very metal-poor Galactic halo stars. The newly determined stellar abundances are surprisingly consistent with a (relative) Solar System r-process pattern, and are also consistent with abundance predictions expected from such neutron-capture nucleosynthesis.Comment: 8 pages, 2 figures, 1 table. To appear in the Proceedings of the NASA Laboratory Astrophysics Workshop in Las Vegas, NV (February 2006

The Westerville Naturals Baseball Team & Otterbein Health And Sport Sciences, Student Project

We had the privilege to give back to our community in the form of manual labor. The Westerville Naturals baseball team needed a hand moving gravel in order to store a shed behind their field. The team provided a gator to transport the gravel from the parking lot to the field. The objective was to scoop shovels full of gravel into the back of the gator. We took multiple trips to load the five tons of gravel and transport it to the new location. Once moved, the sheds needed a facelift so it was decided to paint the sheds. We were able to get in-touch with the coach and schedule a date and time that worked best with all of our schedules. We have also organized the opportunity for the Westerville Naturals’ players take the field with the Otterbein baseball players at a home game, while the national anthem was played. We are hoping this will be the start of a tradition/legacy that the kids look forward too for many years to come. The practice and game field conditions for the youth team will be much more efficient in setting up and tearing down each day. Now that equipment storage is in place, with a more sturdy foundation than before, the team has a tangible reminder about the work that are students were willing to do for them, in order to show support of their team. The entire project has proven to be successful, the only difficult thing being the scheduling. We had to make sure it worked with their team as well as our schedules before we could get started. In the future we would recommend having a few gators to transport the gravel, as it seemed we were standing around waiting for it to get back after being dumped. We would have also liked to have had a larger budget to provide the youth athletes with a piece of memorabilia to remind them of their experience with the Otterbein Baseball Team

Pancreatic β-Cell Death in Response to Pro-Inflammatory Cytokines Is Distinct from Genuine Apoptosis

A reduction in functional β-cell mass leads to both major forms of diabetes; pro-inflammatory cytokines, such as interleukin-1beta (IL-1β) and gamma-interferon (γ-IFN), activate signaling pathways that direct pancreatic β-cell death and dysfunction. However, the molecular mechanism of β-cell death in this context is not well understood. In this report, we tested the hypothesis that individual cellular death pathways display characteristic phenotypes that allow them to be distinguished by the precise biochemical and metabolic responses that occur during stimulus-specific initiation. Using 832/13 and INS-1E rat insulinoma cells and isolated rat islets, we provide evidence that apoptosis is unlikely to be the primary pathway underlying β-cell death in response to IL-1β+γ-IFN. This conclusion was reached via the experimental results of several different interdisciplinary strategies, which included: 1) tandem mass spectrometry to delineate the metabolic differences between IL-1β+γ-IFN exposure versus apoptotic induction by camptothecin and 2) pharmacological and molecular interference with either NF-κB activity or apoptosome formation. These approaches provided clear distinctions in cell death pathways initiated by pro-inflammatory cytokines and bona fide inducers of apoptosis. Collectively, the results reported herein demonstrate that pancreatic β-cells undergo apoptosis in response to camptothecin or staurosporine, but not pro-inflammatory cytokines. DOI: 10.1371/journal.pone.002248

An adenovirus-derived protein: A novel candidate for anti-diabetic drug development

© 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). Aims Exposure to human adenovirus Ad36 is causatively and correlatively linked with better glycemic control in animals and humans, respectively. Although the anti-hyperglycemic property of Ad36 may offer some therapeutic potential, it is impractical to use an infectious agent for therapeutic benefit. Cell-based studies identified that Ad36 enhances cellular glucose disposal via its E4orf1 protein. Ability to improve glycemic control in vivo is a critical prerequisite for further investigating the therapeutic potential of E4orf1. Therefore, the aim of this study was to determine the ability of E4orf1 to improve glycemic control independent of insulin despite high fat diet. Materials & Methods 8-9wk old male C57BL/6J mice fed a high-fat diet (60% kcal) were injected with a retrovirus plasmid expressing E4orf1, or a null vector (Control). Glycemic control was determined by glucose and insulin tolerance test. Islet cell size, amount of insulin and glucagon were determined in formalin-fixed pancreas. Rat insulinoma cell line (832/13) was infected with E4orf1 or control to determine changes in glucose stimulated insulin secretion. Protein from flash frozen adipose tissue depots, liver and muscle was used to determine molecular signaling by western blotting. Results In multiple experiments, retrovirus-mediated E4orf1 expression in C57BL/6J mice significantly and reproducibly improved glucose excursion following a glucose load despite a high fat diet (60% energy). Importantly, E4orf1 improved glucose clearance without increasing insulin sensitivity, production or secretion, underscoring its insulin-independent effect. E4orf1 modulated molecular signaling in mice tissue, which included greater protein abundance of adiponectin, p-AKT and Glucose transporter Glu4. Conclusions This study provides the proof of concept for translational development of E4orf1 as a potential anti-diabetic agent. High fat intake and impaired insulin signaling are often associated with obesity, diabetes and insulin resistance. Hence, the ability of E4orf1 to improve glycemic control despite high fat diet and independent of insulin, is particularly attractive

HST Observations of Heavy Elements in Metal-Poor Galactic Halo Stars

We present new abundance determinations of neutron-capture elements Ge, Zr, Os, Ir, and Pt in a sample of 11 metal-poor (-3.1 <= [Fe/H] <= -1.6) Galactic halo giant stars, based on Hubble Space Telescope UV and Keck I optical high-resolution spectroscopy. The stellar sample is dominated by r-process-rich stars such as the well-studied CS 22892-052 and bd+173248, but also includes the r-process-poor, bright giant HD 122563. Our results demonstrate that abundances of the 3rd r-process peak elements Os, Ir and Pt in these metal-poor halo stars are very well-correlated among themselves, and with the abundances of the canonical r-process element Eu (determined in other studies), thus arguing for a common origin or site for r-process nucleosynthesis of heavier (Z>56) elements. However, the large (and correlated) scatters of [Eu,Os,Ir,Pt/Fe] suggests that the heaviest neutron-capture r-process elements are not formed in all supernovae. In contrast, the Ge abundances of all program stars track their Fe abundances, very well. An explosive process on iron-peak nuclei (e.g., the alpha-rich freeze-out in supernovae), rather than neutron capture, appears to have been the dominant synthesis mechanism for this element at low metallicities -- Ge abundances seem completely uncorrelated with Eu.Comment: 35 pages, 5 tables, 7 figures; To appear in the Astrophysical Journa

The Rise of the s-Process in the Galaxy

From newly-obtained high-resolution, high signal-to-noise ratio spectra the abundances of the elements La and Eu have been determined over the stellar metallicity range -3<[Fe/H]<+0.3 in 159 giant and dwarf stars. Lanthanum is predominantly made by the s-process in the solar system, while Eu owes most of its solar system abundance to the r-process. The changing ratio of these elements in stars over a wide metallicity range traces the changing contributions of these two processes to the Galactic abundance mix. Large s-process abundances can be the result of mass transfer from very evolved stars, so to identify these cases, we also report carbon abundances in our metal-poor stars. Results indicate that the s-process may be active as early as [Fe/H]=-2.6, alalthough we also find that some stars as metal-rich as [Fe/H]=-1 show no strong indication of s-process enrichment. There is a significant spread in the level of s-process enrichment even at solar metallicity.Comment: 64 pages, 15 figures; ApJ 2004 in pres

Hepatic IKKε expression is dispensable for high-fat feeding-induced increases in liver lipid content and alterations in glucose tolerance

© 2020 the American Physiological Society. There are endocrine and immunological changes that occur during onset and progression of the overweight and obese states. The inhibitor of nuclear factor-κB kinase-ε (IKKε) was originally described as an inducible protein kinase; whole body gene deletion or systemic pharmaceutical targeting of this kinase improved insulin sensitivity and glucose tolerance in mice. To investigate the primary sites of action associated with IKKε during weight gain, we describe the first mouse line with conditional elimination of IKKε in the liver (IKKεAlb-/-). IKKεAlb-/- mice and littermate controls gain weight, show similar changes in body composition, and do not display any improvements in insulin sensitivity or whole body glucose tolerance. These studies were conducted using breeder chow diets and matched low- vs. high-fat diets. While glycogen accumulation in the liver is reduced in IKKεAlb-/- mice, lipid storage in liver is similar in IKKεAlb-/- mice and littermate controls. Our results using IKKεAlb-/-mice suggest that the primary action of this kinase to impact insulin sensitivity during weight gain lies predominantly within extrahepatic tissues

Oral Corticosterone Administration Reduces Insulitis but Promotes Insulin Resistance and Hyperglycemia in Male Nonobese Diabetic Mice

© 2017 American Society for Investigative Pathology Steroid-induced diabetes is the most common form of drug-induced hyperglycemia. Therefore, metabolic and immunological alterations associated with chronic oral corticosterone were investigated using male nonobese diabetic mice. Three weeks after corticosterone delivery, there was reduced sensitivity to insulin action measured by insulin tolerance test. Body composition measurements revealed increased fat mass and decreased lean mass. Overt hyperglycemia (\u3e250 mg/dL) manifested 6 weeks after the start of glucocorticoid administration, whereas 100% of the mice receiving the vehicle control remained normoglycemic. This phenotype was fully reversed during the washout phase and readily reproducible across institutions. Relative to the vehicle control group, mice receiving corticosterone had a significant enhancement in pancreatic insulin-positive area, but a marked decrease in CD3+ cell infiltration. In addition, there were striking increases in both citrate synthase gene expression and enzymatic activity in skeletal muscle of mice in the corticosterone group relative to vehicle control. Moreover, glycogen synthase expression was greatly enhanced, consistent with elevations in muscle glycogen storage in mice receiving corticosterone. Corticosterone-induced hyperglycemia, insulin resistance, and changes in muscle gene expression were all reversed by the end of the washout phase, indicating that the metabolic alterations were not permanent. Thus, male nonobese diabetic mice allow for translational studies on the metabolic and immunological consequences of glucocorticoid-associated interventions in a mouse model with genetic susceptibility to autoimmune disease