1,941 research outputs found
Ex Vivo Generation of Dendritic Cells Within a Vascular Bioreactor
Dendritic cells (DCs) play a prime role in the activation and control of the immune system and have promising potential in the treatment of cancer, viral infection, autoimmune diseases and transplantation rejection. DCs can be generated ex vivo from human monocytes by the use of growth factors or during transendothelial migration. Many studies have generated DCs under static, “no flow” conditions. However, such studies do not mimic the “flow” occurring in the capillaries. The objective of this study was to see if we could generate functional DCs within a novel bioreactor system under flow conditions. A HUVEC monolayer was grown on a porous membrane and added it to a bioreactor at 0.4 mL/min. Inflammation was mimicked by adding TNF-α to the system for 48 h. Cell morphology, viability, CAM expression and MCP-1 were measured. CFSE-labeled monocytes were added above the flow path. Monocytes were analyzed for location based on fluorescent intensity and migration markers. Finally, we looked at the differentiation of monocytes into DCs by looking at common DC markers. To test for functionality, we performed a mixed leukocyte reaction (MLR) for seven days and measured proliferation and activation of T-cells.HUVECs maintained a compact network after 72 h. Cell viability with and without TNF-α was 78% and 82%, respectively. Increased VCAM-1 expression (37%) and MCP-1 (6x) act as inflammatory responses to send signals for recruitment of leukocytes. Increased monocyte migration through the stimulated endothelium could be due loose HUVEC junctions. All migration marker expression was downregulated in a stimulated system, possibly due to monocyte shifting away from lineage or differentiation into DCs. DCs from the bioreactor had no morphological differences when compared to static culture. DCs attached to the endothelium expressed 80% CD206, possibly playing a role in their attachment to the endothelium. DCs after culture expressed CD86 and after adding maturation cytokines, bioreactor and static DCs matured as indicated by CD83 expression (72% and 84.9%, respectively). DCs from the bioreactor proliferated activated T-cells more than static DCs as indicated by MFI. Overall, the system was able to generate functional DCs that promoted better T-cell proliferation than traditional methods
\u3cem\u3eWhile dreaming, while writing\u3c/em\u3e (excerpt) by Max Alhau
A free rendering of Max Alhau\u27s While dreaming, while writing, with commentary. The original source text is included
The flight robotics laboratory
The Flight Robotics Laboratory of the Marshall Space Flight Center is described in detail. This facility, containing an eight degree of freedom manipulator, precision air bearing floor, teleoperated motion base, reconfigurable operator's console, and VAX 11/750 computer system, provides simulation capability to study human/system interactions of remote systems. The facility hardware, software and subsequent integration of these components into a real time man-in-the-loop simulation for the evaluation of spacecraft contact proximity and dynamics are described
Transition from PowerPoint to Prezi: Leave the Linear Behind
The purpose of this presentation is to encourage attendees to consider transitioning or trying to develop Prezi presentations. Survey results from Saint Leo University will provide valuable information pertaining to the current use and familiarity of Prezi on a university campus. Results will be based on responses from both a faculty and student perspective. Prezi can often seem overwhelming because of the creativity level of the program. By introducing a step by step process with importing an existing lecture that has been created in PowerPoint, educators may find that using Prezi in the class room does not have to be overwhelming. A number of questions will be addressed regarding how to import an existing PowerPoint directly into Prezi. The objective is to show how to develop a Prezi presentation by utilizing existing PowerPoint presentations. The experience will hopefully ignite interest for educators when delivering new material
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On Cluelessness
This thesis explores the significance of our cluelessness for the general project of moral philosophy. In the first chapter I continue a tradition which uses the facts of our cluelessness to argue against consequentialist accounts of right action. In the second chapter I develop a new cluelessness argument against recently popular relevance approaches to claims aggregation, approaches under which agents are required to maximise the strength-weighted satisfaction of relevant claims upon their conduct. In
the third chapter I respond to the Paralysis Argument, a novel objection developed by Andreas Mogensen & William MacAskill which uses the facts of our cluelessness to undercut the traditional non-consequentialist distinction between reasons for doing versus allowing harm. In responding to the Paralysis Argument, I offer a refined version of the doctrine of doing and allowing harm, one which gives intuitively plausible verdicts in cases of risk and uncertainty. In the fourth chapter I examine whether we might sometimes interpret cluelessness arguments as action-guidingness objections: under action-guidingness objections, a particular moral principle is said to be incorrect insofar as that principle cannot be used by suitably motivated agents in regulating their conduct. I argue against the general merits of action-guidingness objections. I suggest that cluelessness arguments against consequentialism, for instance, can instead be given a more fruitful epistemic reading, a reading I defend in closing
Reduced-order modelling of vortex-induced vibration of catenary riser
A new reduced-order model capable of analyzing the vortex-induced vibration of catenary riser in the ocean current has been developed. This semi analytical-numerical approach is versatile and allows for a significant reduction in computational effort for the analysis of fluid-riser interactions. The incoming current flow is assumed to be steady, uniform, unidirectional and perpendicular to the riser plane of initial equilibrium curvatures. The equations of riser 3-D motion are based on a pinned-pinned, tensioned-beam or flexural cable, modelling which accounts for overall effects of riser bending, extensibility, sag, inclination and structural nonlinearities. The unsteady hydrodynamic forces associated with cross-flow and in-line vibrations are modelled as distributed van der Pol wake oscillators. This hydrodynamic model has been modified in order to capture the effect of varying initial curvatures of the inclined flexible cylinder and to describe the space-time fluctuation of lift and drag forces. Depending on the vortex-excited in-plane/out-of-plane modes and system fluid-structure parameters, the parametric studies are carried out to determine the maximum response amplitudes of catenary risers, along with the occurrence of uni-modal lock-in phenomenon. The obtained results highlight the effect of initial curvatures and geometric nonlinearities on the nonlinear dynamics of riser undergoing vortex-induced vibration
An adaptive depth control system for high speed submarines.
http://www.archive.org/details/adaptivedepthcon00willU.S. Navy (U.S.N.) author
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