754 research outputs found

    H I observations of the peculiar galaxy NGC 660

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    The authors present observations of H I emission from the peculiar galaxy NGC 660. H I was detected in the companion galaxy UGC 01195 as well. Sixteen hours of observations were obtained with the VLA telescope of the National Radio Astronomy Observatory during December 1986 and March 1987

    Bonus points for maths

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    Abstract included in tex

    Standardizing and Disseminating Knowledge: The Role of the OECD in Global Governance

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    If ‘knowledge is power’, it is unsurprising that the production, legitimation, and application of social scientific knowledge, not least that which was designed to harness social organization to economic growth, is a potentially contentious process. Coping with, adapting to, or attempting to shape globalization has emerged as a central concern of policy-makers who are, therefore, interested in knowledge to assist their managerial activities. Thus, an organization that can create, synthesize, legitimate, and dissemination useful knowledge can play a significant role in the emerging global governance system. The OECD operates as one important site for the construction, standardization, and dissemination of transnational policy ideas. OECD staff conducts research and produces a range of background studies and reports, drawing on disciplinary knowledge (typically economics) supplemented by their ‘organizational discourses’. This paper probes the contested nature of knowledge production and attempts to evaluate the impact of the OECD’s efforts to produce globally applicable policy advice. Particular attention is paid to important initiatives in the labour market and social policy fields—the Jobs Study and Babies and Bosses

    Fluidic logic for the control and design of soft robotic systems

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    State-of-the-art in robotics are machines that do jobs. These jobs, for instance, can be automated routine procedures for delivering services with minimal human intervention or the task of building, maintaining or removing infrastructure in areas where it is too dangerous for humans to go. These assignments and tasks are open areas of research which can have a net-positive impact on society. We make robots from subsystems of hard components and rigid links in a physical system stacked in a hierarchy--building blocks of transistors on printed circuit boards in integrated approaches to control motors and end effectors. The hard characteristic of these systems means we can predict the motion and trajectory of robots. However, these constrained environments limit the places we can use robots. Suppose we would like to use a robot to interact with a human. In that case, the rigid materials and control systems may be incompatible with this unconstrained environment. Soft robots represent a change in thinking about robotic systems' dominant materials and control methods. Soft roboticists use soft materials, compliant joints with variable stiffness, and deformable systems in interaction with the environment. Rather than using motors, soft robots use air or other fluids to inflate and deflate chambers to make soft robots move and grasp. The design heuristic in soft robotics combines simple elements to create more complex systems. In this hierarchical architecture, there is a one-to-one mapping of control hardware to actuators resulting in systems that are increasingly capable of a diverse range of movements and actions. Nevertheless, as soft robots become even more capable, we will reach practical limits in size and control. This thesis explores the interdependence of architecture and control, moving beyond the current design heuristic to increase the capability of soft robots. An ideal control system in a soft robot has a low number of hardware outputs controlling a large number of actuators. Such an architecture could improve our ability to implement desired motions and behaviours to perform valuable tasks and move towards increased autonomy in soft robotics. This problem is reminiscent of the mechanical analogue systems developed in the \nth{20} century for numerical ballistic calculations. A solution using an abstract system of logic and philosophy ultimately led to the invention of the transistor and the electronics hierarchy of transistors on printed circuit boards and integrated systems in computers and robotics today. In this study, I use a fluidic transistor primitive to build memory elements based on logic gates and combinational logic to control arrays of actuators. The contributions of this thesis include the following: (i) a perspective on the current paradigm in soft robotic architecture and the scaling problem of control schemes in soft robots; (ii) the uses of stacking and hierarchy as a design principle in soft robots; (iii) the applications of sequential logic and memory for multi-state automata soft robots; (iv) a description of design dependencies for fluidic systems for medium-to-large scale integration. In summary, I address the significant challenge in soft robotic control and design, moving beyond the limitation of the control architecture toward autonomy using a fluidic architecture. I move through the levels of automata theory from combinational logic to sequential circuits and finite-state machines using fluidic transistors. My studies may help lay the foundations of a fluidic hardware description language for building large-scale integrated fluidic circuits in soft robotics design

    Efficient delivery of small interfering RNA for inhibition of IL-12p40 expression in vivo

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    Background: RNA interference is an evolutionary conserved immune response mechanism that can be used as a tool to provide novel insights into gene function and structure. The ability to efficiently deliver small interfering RNA to modulate gene expression in vivo may provide new therapeutic approaches to currently intractable diseases. Methods: In vitro, siRNA targeting IL-12p40 was delivered to the murine macrophage cell line (J774A.1) encapsulated in a liposome with an IL-12 inducing agent (LPS/IFN-γ) over a number of time points. Controls included a variety of non-target specific siRNA reagents. Supernatants were analyzed for cytokine production while the cells were removed for mRNA profiling. In vivo, siRNA-targeting IL-12p40 was delivered to the murine peritoneal cavity in a therapeutic fashion, after endotoxin (LPS) challenge. Cells from the peritoneal cavity were removed by lavage and analyzed by flow cytometry. Levels of IL-12 present in lavage and in serum were also examined by ELISA. Results: In this report, we show that IL-12p40 siRNA can specifically silence macrophage expression of IL-12p40 mRNA and IL-12p70 protein in vitro. We extend this finding to demonstrate that delivery of liposome encapsulated siRNA targeting IL-12p40 to the murine peritoneal cavity can modulate an inflammatory stimulus in vivo. Furthermore, specific siRNA can be used therapeutically after endotoxin challenge to reduce both the local and systemic inflammatory response. Thus, the delivery of siRNA can be used to elicit specific non-permanent inhibition of endogenous protein expression. Conclusion: In vitro silencing of IL-12p40 using siRNA at selected doses leads to specific knockdown of IL-12p70 protein production without inducing type I interferons. Furthermore, siRNA targeting murine IL-12p40 can be used therapeutically to counter an inflammatory response in vivo

    Efficient delivery of small interfering RNA for inhibition of IL-12p40 expression in vivo

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    Background: RNA interference is an evolutionary conserved immune response mechanism that can be used as a tool to provide novel insights into gene function and structure. The ability to efficiently deliver small interfering RNA to modulate gene expression in vivo may provide new therapeutic approaches to currently intractable diseases. Methods: In vitro, siRNA targeting IL-12p40 was delivered to the murine macrophage cell line (J774A.1) encapsulated in a liposome with an IL-12 inducing agent (LPS/IFN-γ) over a number of time points. Controls included a variety of non-target specific siRNA reagents. Supernatants were analyzed for cytokine production while the cells were removed for mRNA profiling. In vivo, siRNA-targeting IL-12p40 was delivered to the murine peritoneal cavity in a therapeutic fashion, after endotoxin (LPS) challenge. Cells from the peritoneal cavity were removed by lavage and analyzed by flow cytometry. Levels of IL-12 present in lavage and in serum were also examined by ELISA. Results: In this report, we show that IL-12p40 siRNA can specifically silence macrophage expression of IL-12p40 mRNA and IL-12p70 protein in vitro. We extend this finding to demonstrate that delivery of liposome encapsulated siRNA targeting IL-12p40 to the murine peritoneal cavity can modulate an inflammatory stimulus in vivo. Furthermore, specific siRNA can be used therapeutically after endotoxin challenge to reduce both the local and systemic inflammatory response. Thus, the delivery of siRNA can be used to elicit specific non-permanent inhibition of endogenous protein expression. Conclusion: In vitro silencing of IL-12p40 using siRNA at selected doses leads to specific knockdown of IL-12p70 protein production without inducing type I interferons. Furthermore, siRNA targeting murine IL-12p40 can be used therapeutically to counter an inflammatory response in vivo

    IL-1b and TNF-a induce increased expression of CCL28 by airway epithelial cells via an NFjB-dependent pathway

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    CCL28 is a mucosal chemokine that attracts eosinophils and T cells via the receptors CCR3 and CCR10. Consequently, it is a candidate mediator of the pathology associated with asthma. This study examined constitutive and induced expression of CCL28 by A549 human airway epithelial-like cells. Real-time RT-PCR and ELISA of cultured cells and supernatants revealed constitutive levels of CCL28 expression to be low, whereas IL-1b and TNF-a, induced signiï¬cantly increased expression. Observations from induced sputum and human airway biopsies supported this. Signal transduction studies revealed that IL-1b and TNF-a stimulation induced NFjB phosphorylation in A549 cells, but antagonist inhibition of NFjB p50âp65 phosphorylation correlated with marked reduction of IL-1b or TNF-a induced CCL28 expression. Together these studies imply a role for CCL28 in the orchestration of airway inï¬ammation, and suggest that CCL28 is one link between microbial insult and the exacerbation of pathologies such as asthma, through an NFjB-dependent mechanism

    Efficient delivery of small interfering RNA for inhibition of IL-12p40 expression in vivo

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    Background: RNA interference is an evolutionary conserved immune response mechanism that can be used as a tool to provide novel insights into gene function and structure. The ability to efficiently deliver small interfering RNA to modulate gene expression in vivo may provide new therapeutic approaches to currently intractable diseases. Methods: In vitro, siRNA targeting IL-12p40 was delivered to the murine macrophage cell line (J774A.1) encapsulated in a liposome with an IL-12 inducing agent (LPS/IFN-γ) over a number of time points. Controls included a variety of non-target specific siRNA reagents. Supernatants were analyzed for cytokine production while the cells were removed for mRNA profiling. In vivo, siRNA-targeting IL-12p40 was delivered to the murine peritoneal cavity in a therapeutic fashion, after endotoxin (LPS) challenge. Cells from the peritoneal cavity were removed by lavage and analyzed by flow cytometry. Levels of IL-12 present in lavage and in serum were also examined by ELISA. Results: In this report, we show that IL-12p40 siRNA can specifically silence macrophage expression of IL-12p40 mRNA and IL-12p70 protein in vitro. We extend this finding to demonstrate that delivery of liposome encapsulated siRNA targeting IL-12p40 to the murine peritoneal cavity can modulate an inflammatory stimulus in vivo. Furthermore, specific siRNA can be used therapeutically after endotoxin challenge to reduce both the local and systemic inflammatory response. Thus, the delivery of siRNA can be used to elicit specific non-permanent inhibition of endogenous protein expression. Conclusion: In vitro silencing of IL-12p40 using siRNA at selected doses leads to specific knockdown of IL-12p70 protein production without inducing type I interferons. Furthermore, siRNA targeting murine IL-12p40 can be used therapeutically to counter an inflammatory response in vivo
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