13 research outputs found
Recommended from our members
Policy Entrepreneurship by International Bureaucracies: The Evolution of Public Information in UN Peacekeeping
The UN Secretariat’s role in the expansion of peacekeeping after the cold war is debated. Different theoretical accounts offer competing interpretations: principal–agent models and sociological institutionalism tend to emphasize the Secretariat’s risk-averse behaviour; organizational learning scholarship and international political sociology find evidence of the Secretariat’s activism; constructivism analyses instances of both. I argue that the UN Secretariat can be both enthusiastic and cautious about new tasks depending on the circumstances and the issue area. For example, UN officials have been the driving force behind the development of public information campaigns by peacekeeping missions aimed at the local population. During the cold war, it was not regarded as necessary for UN missions to communicate with the public in the area of operation: their interlocutors were parties to the conflict and the diplomatic community. With the deployment of the first multidimensional missions in the late 1980s and the early 1990s, UN staff realized the need to explain the organization’s role to the local population and provide information about UN-supported elections. In promoting this innovation, they played the role of policy entrepreneurs. The institutionalization of this innovation, however, was not an automatic process and required continuous advocacy by UN information staff
Steno bredanensis, demographic and morphometric data from 2004 and 2005 Florida mass strandings
Design, Analysis, and Test of a High-Powered Model Rocket-1
This paper describes the design of a high-powered model rocket (HPMR) that incorporates innovative subsystems for stage separation, and recovery. The first stage of the HPMR is separated using a set of airbrakes deployed in flight. The second stage uses an autorotation system to control the descent velocity. An analysis of the composite motor was completed using Cantera and COMSOL to model the chemical equilibrium reaction and evaluate the temperature distribution in the motor during flight. These results were used to provide chamber conditions in a MATLAB model for ideal rocket performance. The electrical and thermal characteristics of the e-match ignitor were also modeled using COMSOL. Aerodynamic loads on the vehicle airframe, autorotation blades, air brakes, and fins used for spin stabilization were evaluated using computational fluid dynamic (CFD) tools in Ansys Fluent. Results from the CFD analysis were used as inputs to a dynamical simulation of the vehicle trajectory, implemented in MATLAB. Ansys Workbench was used for structural analysis. Results are presented from these analyses as well as a description of prototype construction and testing completed at the subsystem level
Recommended from our members
Clinical and Genomic Correlates of Neutrophil Reactive Oxygen Species Production in Pediatric Patients With Crohn’s Disease
Background & aimsIndividuals with monogenic disorders of phagocyte function develop chronic colitis that resembles Crohn's disease (CD). We tested for associations between mutations in genes encoding reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, neutrophil function, and phenotypes of CD in pediatric patients.MethodsWe performed whole-exome sequence analysis to identify mutations in genes encoding NADPH oxidases (such as CYBA, CYBB, NCF1, NCF2, NCF4, RAC1, and RAC2) using DNA from 543 pediatric patients with inflammatory bowel diseases. Blood samples were collected from an additional 129 pediatric patients with CD and 26 children without IBD (controls); we performed assays for neutrophil activation, reactive oxygen species (ROS) production, and bacteria uptake and killing. Whole-exome sequence analysis was performed using DNA from 46 of the children with CD to examine associations with NADPH gene mutations; RNA sequence analyses were performed using blood cells from 46 children with CD to test for variations in neutrophil gene expression associated with ROS production.ResultsWe identified 26 missense mutations in CYBA, CYBB, NCF1, NCF2, and NCF4. Patients with CD who carried mutations in these genes were 3-fold more likely to have perianal disease (P = .0008) and stricturing complications (P = .002) than children with CD without these mutations. Among patients with CD with none of these mutations, 9% had undergone abdominal surgery; among patients with mutations in these NADPH oxidase genes, 31% had undergone abdominal surgery (P = .0004). A higher proportion of neutrophils from children with CD had low ROS production (47%) than from controls (15%) among the 129 patients tested for ROS (P = .002). Minor alleles of the NADPH genes were detected in 7% of children with CD whose neutrophils produced normal levels of ROS vs 38% of children whose neutrophils produced low levels of ROS (P = .009). Neutrophils that produced low levels of ROS had specific alterations in genes that regulate glucose metabolism and antimicrobial responses.ConclusionsWe identified missense mutations in genes that encode NADPH oxidases in children with CD; these were associated with a more aggressive disease course and reduced ROS production by neutrophils from the patients
Recommended from our members
Genetic and Transcriptomic Variation Linked to Neutrophil Granulocyte-Macrophage Colony-Stimulating Factor Signaling in Pediatric Crohn's Disease.
BACKGROUND:Granulocyte-macrophage colony-stimulating factor auto-antibodies (GMAbs) suppress neutrophil-extrinsic GM-CSF signaling and increase risk for stricturing behavior in Crohn's disease (CD). We aimed to define clinical, genomic, and functional associations with neutrophil-intrinsic GM-CSF signaling. METHODS:Missense mutations in CSF2RA, CSF2RB, JAK2, STAT5A, and STAT5B were identified using whole-exome sequencing in 543 pediatric inflammatory bowel disease (IBD) patients. Neutrophil-intrinsic GM-CSF signaling was defined using the GM-CSF-induced STAT5 stimulation index (GMSI) in 180 pediatric IBD patients and 26 non-IBD controls. Reduced GM-CSF signaling (GMSI-Lo) was defined as the 20th percentile within the control group. Variation in neutrophil phospho-protein abundance, bacterial killing, and the global pattern of gene expression with the GMSI was determined. RESULTS:We validated 18 potentially damaging missense mutations in CSF2RA and CSF2RB. CSF2RA A17G carriage increased from 10% in those with intact neutrophil GMSI to 32% in those with low GMSI (P = 0.02). The frequency of reduced Staphylococcus aureus killing increased from 17% in those with intact neutrophil GMSI to 35% in GMSI-Lo neutrophils (P = 0.043). Crohn's disease neutrophils with low GMSI exhibited specific alterations in phospho-protein networks and genes regulating cytokine production, wound healing, and cell survival and proliferation. Stricturing behavior increased from 7% in patients with both low GMAb and intact GMSI to 64% in patients with both elevated GMAb and low GMSI (P < 0.0001). CONCLUSIONS:Low/normal neutrophil-intrinsic GM-CSF signaling is associated with CSF2RA missense mutations, alterations in gene expression networks, and higher rates of disease complications in pediatric CD
Recommended from our members
Genetic and Transcriptomic Variation Linked to Neutrophil Granulocyte-Macrophage Colony-Stimulating Factor Signaling in Pediatric Crohn's Disease.
BACKGROUND:Granulocyte-macrophage colony-stimulating factor auto-antibodies (GMAbs) suppress neutrophil-extrinsic GM-CSF signaling and increase risk for stricturing behavior in Crohn's disease (CD). We aimed to define clinical, genomic, and functional associations with neutrophil-intrinsic GM-CSF signaling. METHODS:Missense mutations in CSF2RA, CSF2RB, JAK2, STAT5A, and STAT5B were identified using whole-exome sequencing in 543 pediatric inflammatory bowel disease (IBD) patients. Neutrophil-intrinsic GM-CSF signaling was defined using the GM-CSF-induced STAT5 stimulation index (GMSI) in 180 pediatric IBD patients and 26 non-IBD controls. Reduced GM-CSF signaling (GMSI-Lo) was defined as the 20th percentile within the control group. Variation in neutrophil phospho-protein abundance, bacterial killing, and the global pattern of gene expression with the GMSI was determined. RESULTS:We validated 18 potentially damaging missense mutations in CSF2RA and CSF2RB. CSF2RA A17G carriage increased from 10% in those with intact neutrophil GMSI to 32% in those with low GMSI (P = 0.02). The frequency of reduced Staphylococcus aureus killing increased from 17% in those with intact neutrophil GMSI to 35% in GMSI-Lo neutrophils (P = 0.043). Crohn's disease neutrophils with low GMSI exhibited specific alterations in phospho-protein networks and genes regulating cytokine production, wound healing, and cell survival and proliferation. Stricturing behavior increased from 7% in patients with both low GMAb and intact GMSI to 64% in patients with both elevated GMAb and low GMSI (P < 0.0001). CONCLUSIONS:Low/normal neutrophil-intrinsic GM-CSF signaling is associated with CSF2RA missense mutations, alterations in gene expression networks, and higher rates of disease complications in pediatric CD