140 research outputs found
Emergency Contracting: Themes from Agencies’ Disaster and Pandemic Response Efforts
Symposium PresentationApproved for public release; distribution is unlimited
Emergency Contracting: Themes from Agencies’ Disaster and Pandemic Response Efforts
Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumThe federal response to the rising number of natural disasters coupled with other emergency response efforts, such as those for COVID-19, have illustrated the important role that federal contracts have in providing life-saving and life-sustaining goods and services. However, contracting during an emergency can pose a unique set of challenges as contracting officials face significant pressure to provide these services as quickly as possible. Leveraging several U.S. Government Accountability Office (GAO) reviews of emergency contracting issues, this paper examines (1) contract and agreement mechanisms agencies used to facilitate response efforts; (2) challenges planning and executing contracts in an emergency environment; and (3) how tracking contract obligations and contracting lessons learned can inform future response efforts.Approved for public release; distribution is unlimited
Content Analysis of International STEM Education Research Journals
STEM education emerged as a focus for educators and researchers in the United States as more states and schools implement integrated, STEM-driven curricula and instruction in order to improve students’ STEM literacy, critical thinking skills, and 21st century workforce skills (Bybee, 2013). This study used content analysis (Grbich, 2013; Hsieh & Shannon, 2005) to investigate recent trends in STEM education research by analyzing all of the published articles in three international STEM education research journals. The criteria for journal selection were publication origination date, number of articles published, and ability to obtain the journals through student-accessible databases or journal websites. Data included the number and types of STEM subjects, whether or not the STEM subjects were integrated, the date of publication, and the setting and participants. Findings from this study suggest that STEM education research articles tend to focus on two or more STEM silos, with the number of iSTEM education research articles increasing in publication over time. Future research in STEM education should include K–12 settings to complement the work already being performed in higher education settings.
ReferencesBybee, R. W. (2013). The case for STEM education: Challenges and opportunities. Arlington, VA: National Science Teachers Association.Grbich, C. (2013). Qualitative data analysis: An introduction. Los Angeles, CA: SAGE.Hsieh, H. F., & Shannon, S. E. (2005). Three approaches to qualitative content analysis. Qualitative Health Research, 15(9), 1277–1288. doi:10.1177/104973230527668
Strategies to reduce attrition in managing paediatric obesity:A systematic review
OBJECTIVE: To conduct a systematic review of the literature for strategies designed to reduce attrition in managing paediatric obesity. METHODS: We searched Ovid Medline (1946 to May 6, 2020), Ovid Embase (1974 to May 6, 2020), EBSCO CINAHL (inception to May 6, 2020), Elsevier Scopus (inception to April 14, 2020), and ProQuest Dissertations & Theses (inception to April 14, 2020). Reports were eligible if they included any obesity management intervention, included 2 to 18 year olds with overweight or obesity (or if the mean age of participants fell within this age range), were in English, included experimental study designs, and had attrition reduction as a main outcome. Two team members screened studies, abstracted data, and appraised study quality. RESULTS: Our search yielded 5,415 original reports; six met inclusion criteria. In three studies, orientation sessions (n = 2) and motivational interviewing (MI) (n = 1) were used as attrition-reduction strategies before treatment enrollment; in three others, text messaging (n = 2) and MI (n = 1) supplemented existing obesity management interventions. Attrition-reduction strategies led to decreased attrition in two studies, increased in one, and no difference in three. For the two strategies that reduced attrition, (a) pre-treatment orientation and (b) text messaging between children and intervention providers were beneficial. The quality of the six included studies varied (good [n = 4]; poor [n = 2]). CONCLUSION: Some evidence suggests that attrition can be reduced. The heterogeneity of approaches applied and small number of studies included highlight the need for well-designed, experimental research to test the efficacy and effectiveness of strategies to reduce attrition in managing paediatric obesity
Assimilation of Oil-Derived Elements by Oysters Due to the Deepwater Horizon Oil Spill
During and after the Deepwater Horizon Oil Spill (DWHOS), oysters (Crassostrea virginica) were exposed to oil and susceptible to incidental consumption of surface and subsurface oil materials. We determined the contribution of oil materials from the DWHOS to diet of oysters by comparing carbon (C) and nitrogen (N) stable isotope ratios in oyster shell to ratios in suspended particulate matter (SPM) and in fresh and weathered oil. Average δ13C and δ15N values in oyster shell (−21 ± 1‰ and 9−11‰, respectively) were consistent with consumption of naturally available SPM as opposed to values in oil (−27 ± 0.2‰, 1.6 ± 0.4‰). Stable isotope ratios in oyster adductor muscle were similar to shell for δ15N but not δ13C, suggesting either a recent shift in diet composition or differential assimilation of C between tissue types. We found no evidence of assimilation of oil-derived C and N and, therefore, no evidence of an oyster-based conduit to higher trophic levels. Trace elements in shell were inconclusive to corroborate oil exposure. These findings are not an indication that oysters were not exposed to oil; rather they imply oysters either did not consume oil-derived materials or consumed too little to be detectable compared to natural diet
Epithelial-mesenchymal transitions: the importance of changing cell state in development and disease
The events that convert adherent epithelial cells into individual migratory cells that can invade the extracellular matrix are known collectively as epithelial-mesenchymal transition (EMT). Throughout evolution, the capacity of cells to switch between these two cellular states has been fundamental in the generation of complex body patterns. Here, we review the EMT events that build the embryo and further discuss two prototypical processes governed by EMT in amniotes: gastrulation and neural crest formation. Cells undergo EMT to migrate and colonize distant territories. Not surprisingly, this is also the mechanism used by cancer cells to disperse throughout the body
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Open Science principles for accelerating trait-based science across the Tree of Life.
Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles-open data, open source and open methods-is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges
Kynurenine Inhibits Autophagy and Promotes Senescence in Aged Bone Marrow Mesenchymal Stem Cells Through the Aryl Hydrocarbon Receptor Pathway
Osteoporosis is an age-related deterioration in bone health that is, at least in part, a stem cell disease. The different mechanisms and signaling pathways that change with age and contribute to the development of osteoporosis are being identified. One key upstream mechanism that appears to target a number of osteogenic pathways with age is kynurenine, a tryptophan metabolite and an endogenous Aryl hydrocarbon receptor (AhR) agonist. The AhR signaling pathway has been reported to promote aging phenotypes across species and in different tissues. We previously found that kynurenine accumulates with age in the plasma and various tissues including bone and induces bone loss and osteoporosis in mice. Bone marrow mesenchymal stem cells (BMSCs) are responsible for osteogenesis, adipogenesis, and overall bone regeneration. In the present study, we investigated the effect of kynurenine on BMSCs, with a focus on autophagy and senescence as two cellular processes that control BMSCs proliferation and differentiation capacity. We found that physiological levels of kynurenine (10 and 100 μM) disrupted autophagic flux as evidenced by the reduction of LC3B-II, and autophagolysosomal production, as well as a significant increase of p62 protein level. Additionally, Kynurenine also induced a senescent phenotype in BMSCs as shown by the increased expression of several senescence markers including senescence associated β-galactosidase in BMSCs. Additionally, western blotting reveals that levels of p21, another marker of senescence, also increased in kynurenine-treated BMSCs, while senescent-associated aggregation of nuclear H3K9me3 also showed a significant increase in response to kynurenine treatment. To validate that these effects are in fact due to AhR signaling pathway, we utilized two known AhR antagonists: CH-223191, and 3’,4’-Dimethoxyflavone to try to block AhR signaling and rescue kynurenine/AhR mediated effects. Indeed, AhR inhibition restored kynurenine-suppressed autophagy levels as shown by levels of LC3B-II, p62 and autophagolysosomal formation demonstrating a rescuing of autophagic flux. Furthermore, inhibition of AhR signaling prevented the kynurenine-induced increase in senescence associated β-galactosidase and p21 levels, as well as blocking aggregation of nuclear H3K9me3. Taken together, our results suggest that kynurenine inhibits autophagy and induces senescence in BMSCs via AhR signaling, and that this may be a novel target to prevent or reduce age-associated bone loss and osteoporosis
Design and Analysis of Rhesus Cytomegalovirus IL-10 Mutants as a Model for Novel Vaccines against Human Cytomegalovirus
Human cytomegalovirus (HCMV) expresses a viral ortholog (CMVIL-10) of human cellular interleukin-10 (cIL-10). Despite only ∼26% amino acid sequence identity, CMVIL-10 exhibits comparable immunosuppressive activity with cIL-10, attenuates HCMV antiviral immune responses, and contributes to lifelong persistence within infected hosts. The low sequence identity between CMVIL-10 and cIL-10 suggests vaccination with CMVIL-10 may generate antibodies that specifically neutralize CMVIL-10 biological activity, but not the cellular cytokine, cIL-10. However, immunization with functional CMVIL-10 might be detrimental to the host because of its immunosuppressive properties.Structural biology was used to engineer biologically inactive mutants of CMVIL-10 that would, upon vaccination, elicit a potent immune response to the wild-type viral cytokine. To test the designed proteins, the mutations were incorporated into the rhesus cytomegalovirus (RhCMV) ortholog of CMVIL-10 (RhCMVIL-10) and used to vaccinate RhCMV-infected rhesus macaques. Immunization with the inactive RhCMVIL-10 mutants stimulated antibodies against wild-type RhCMVIL-10 that neutralized its biological activity, but did not cross-react with rhesus cellular IL-10.This study demonstrates an immunization strategy to neutralize RhCMVIL-10 biological activity using non-functional RhCMVIL-10 antigens. The results provide the methodology for targeting CMVIL-10 in vaccine, and therapeutic strategies, to nullify HCMV's ability to (1) skew innate and adaptive immunity, (2) disseminate from the site of primary mucosal infection, and (3) establish a lifelong persistent infection
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