37 research outputs found
SOF’S ROLE IN STRATEGIC COMPETITION: A WARGAME
Includes Supplementary MaterialCan a wargame effectively model how Special Operation Forces’ (SOF) irregular warfare capabilities influence strategic competition, and more broadly, do wargames have a place in the education of SOF professionals? SOF needs educational tools that stimulate critical thinking and intellectual creativity to address the challenges and complexities of irregular warfare and strategic competition so they can maintain their position as the DOD’s premier option for irregular warfare. Educational wargames have an extensive history in professional military organizations, and the wargame Tears of Tyranny is ready for use now to educate joint SOF on irregular warfare at the tactical and operational levels. Further development of Tears of Tyranny should include digitization and refinement through an additional capstone team.Outstanding ThesisMajor, United States ArmyMajor, United States ArmyMajor, United States ArmyMajor, United States ArmyApproved for public release. Distribution is unlimited
Air quality and error quantity: pollution and performance in a high-skilled, quality-focused occupation
We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly-skilled, quality-focused employees. We repeatedly observe the decision-making of individual professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle effects of multiple pollutants and identify previously under-explored acute effects. We find a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls and a 10 mg/m3 increase in 12-hour PM2.5 causes a 2.6% increase. We control carefully for a variety of potential confounders and results are supported by robustness and falsification checks
Exhaustive Sampling of Docking Poses Reveals Binding Hypotheses for Propafenone Type Inhibitors of P-Glycoprotein
Overexpression of the xenotoxin transporter P-glycoprotein (P-gp) represents one major reason for the development of multidrug resistance (MDR), leading to the failure of antibiotic and cancer therapies. Inhibitors of P-gp have thus been advocated as promising candidates for overcoming the problem of MDR. However, due to lack of a high-resolution structure the concrete mode of interaction of both substrates and inhibitors is still not known. Therefore, structure-based design studies have to rely on protein homology models. In order to identify binding hypotheses for propafenone-type P-gp inhibitors, five different propafenone derivatives with known structure-activity relationship (SAR) pattern were docked into homology models of the apo and the nucleotide-bound conformation of the transporter. To circumvent the uncertainty of scoring functions, we exhaustively sampled the pose space and analyzed the poses by combining information retrieved from SAR studies with common scaffold clustering. The results suggest propafenone binding at the transmembrane helices 5, 6, 7 and 8 in both models, with the amino acid residue Y307 playing a crucial role. The identified binding site in the non-energized state is overlapping with, but not identical to, known binding areas of cyclic P-gp inhibitors and verapamil. These findings support the idea of several small binding sites forming one large binding cavity. Furthermore, the binding hypotheses for both catalytic states were analyzed and showed only small differences in their protein-ligand interaction fingerprints, which indicates only small movements of the ligand during the catalytic cycle
Being Good or Being Known: An Empirical Examination of the Dimensions, Antecedents, and Consequences of Organizational Reputation
Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission
AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p
Breast Cancer Resistance Protein Interacts with Various Compounds in Vitro, but Plays a Minor Role in Substrate Efflux at the Blood-Brain Barrier
Expression of breast cancer resistance protein (Bcrp) at the blood-brain
barrier (BBB) has been revealed recently. To investigate comprehensively the
potential role of Bcrp at the murine BBB, a chemically diverse set of model
compounds (cimetidine, alfuzosin, dipyridamole, and LY2228820) was evaluated
using a multiexperimental design. Bcrp1 stably transfected MDCKII cell
monolayer transport studies demonstrated that each compound had affinity for
Bcrp and that polarized transport by Bcrp was abolished completely by the Bcrp
inhibitor chrysin. However, none of the compounds differed in brain uptake
between Bcrp wild-type and knockout mice under either an in situ brain
perfusion or a 24-h subcutaneous osmotic minipump continuous infusion
experimental paradigm. In addition, alfuzosin and dipyridamole were shown to
undergo transport by P-glycoprotein (P-gp) in an MDCKII-MDR1 cell monolayer
model. Alfuzosin brain uptake was 4-fold higher in
mdr1a(–/–) mice than in mdr1a(+/+) mice in in
situ and in vivo studies, demonstrating for the first time that it undergoes
P-gp-mediated efflux at the BBB. In contrast, P-gp had no effect on
dipyridamole brain penetration in situ or in vivo. In fact, in situ BBB
permeability of these solutes appeared to be primarily dependent on their
lipophilicity in the absence of efflux transport, and in situ brain uptake
clearance correlated with the intrinsic transcellular passive permeability
from in vitro transport and cellular accumulation studies. In summary, Bcrp
mediates in vitro transport of various compounds, but seems to play a minimal
role at the BBB in vivo