1,321 research outputs found
In-vitro demonstration of cell-mediated immunity to vaccinia virus in man
Cell mediated immunity to vaccinia virus in man was studied by lymphocyte transformation. Vaccinia antigen, propagated on BHK-21 and Vero cells, could be used successfully for in-vitro testing after partial purification as well as crude infectious homogenates. Vaccinia antigen preparations were effective both in the infective and the inactivated state. Inactivation was usually accompanied with a certain loss of stimulating activity. Development of cell mediated immune response in-vitro after first vaccination was investigated in 17 adults. Vaccinia virus specific lymphocyte transformation was seen in the second week after vaccination in all cases. Following revaccination no increase of lymphocyte transformation ratio could be observed in 11 persons studied. At the same time the titers of humoral antibodies were elevated
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Centrifuge modelling of tunnelling with forepoling
Geotechnical centrifuge modelling provides a means by which geotechnical events and processes can be better understood. In particular, the technique has proved invaluable when investigating collapse mechanisms in small scale models that can be related to full scale events. A series of eight plane strain centrifuge model tests investigating the effect of inserting inclusions around the annulus of a single tunnel in over consolidated clay has been conducted using the geotechnical centrifuge at City University London. The model used a compressed air supported circular cavity to simulate the tunnel. Stiff resin inclusions embedded around its periphery were used to represent closely spaced forepoles forming grout umbrella arches. Image processing was used to obtain patterns of displacements at the subsurface and displacement transducers measured vertical settlement at the ground surface level. The investigation focused on how different arrangements of forepoling affected tunnel stability. The influence of forepoling on normally accepted plastic collapse mechanisms is discussed. An optimisation of the forepoling layout is uggested in accordance with the findings
Cultivating compliance: governance of North Indian organic basmati smallholders in a global value chain
Focusing on a global value chain (GVC) for organic basmati rice, we study how farmers’ practices are governed through product and process standards, organic certification protocols, and contracts with buyer firms. We analyze how farmers’ entry into the GVC reconfigures their agencements (defined as heterogeneous arrangements of human and nonhuman agencies which are associated with each other). These reconfigurations entail the severance of some associations among procedural and material elements of the agencements and the formation of new associations, in order to produce cultivation practices that are accurately described by the GVC’s standards and protocols. Based on ethnography of two farmers in Uttarakhand, North India, we find that the same standards were enacted differently on the two farmers’ fields, producing variable degrees of (selective) compliance with the ‘official’ GVC standards. We argue that the disjuncture between the ‘official’ scripts of the standards and actual cultivation practices must be nurtured to allow farmers’ agencements to align their practices with local sociotechnical relations and farm ecology. Furthermore, we find that compliance and disjuncture were facilitated by many practices and associations that were officially ungoverned by the GVC
On the Signed -independence Number of Graphs
In this paper, we study the signed 2-independence number in graphs and give new sharp upper and lower bounds on the signed 2-independence number of a graph by a simple uniform approach. In this way, we can improve and generalize some known results in this area
A frequency and sensitivity tunable microresonator array for high-speed quantum processor readout
Superconducting microresonators have been successfully utilized as detection
elements for a wide variety of applications. With multiplexing factors
exceeding 1,000 detectors per transmission line, they are the most scalable
low-temperature detector technology demonstrated to date. For high-throughput
applications, fewer detectors can be coupled to a single wire but utilize a
larger per-detector bandwidth. For all existing designs, fluctuations in
fabrication tolerances result in a non-uniform shift in resonance frequency and
sensitivity, which ultimately limits the efficiency of band-width utilization.
Here we present the design, implementation, and initial characterization of a
superconducting microresonator readout integrating two tunable inductances per
detector. We demonstrate that these tuning elements provide independent control
of both the detector frequency and sensitivity, allowing us to maximize the
transmission line bandwidth utilization. Finally we discuss the integration of
these detectors in a multilayer fabrication stack for high-speed readout of the
D-Wave quantum processor, highlighting the use of control and routing circuitry
composed of single flux-quantum loops to minimize the number of control wires
at the lowest temperature stage.Comment: 8 pages, 9 figure
The generalized 3-edge-connectivity of lexicographic product graphs
The generalized -edge-connectivity of a graph is a
generalization of the concept of edge-connectivity. The lexicographic product
of two graphs and , denoted by , is an important graph
product. In this paper, we mainly study the generalized 3-edge-connectivity of
, and get upper and lower bounds of .
Moreover, all bounds are sharp.Comment: 14 page
How to suppress undesired synchronization
It is delightful to observe the emergence of synchronization in the blinking
of fireflies to attract partners and preys. Other charming examples of
synchronization can also be found in a wide range of phenomena such as, e.g.,
neurons firing, lasers cascades, chemical reactions, and opinion formation.
However, in many situations the formation of a coherent state is not pleasant
and should be mitigated. For example, the onset of synchronization can be the
root of epileptic seizures, traffic congestion in communication networks, and
the collapse of constructions. Here we propose the use of contrarians to
suppress undesired synchronization. We perform a comparative study of different
strategies, either requiring local or total knowledge of the system, and show
that the most efficient one solely requires local information. Our results also
reveal that, even when the distribution of neighboring interactions is narrow,
significant improvement in mitigation is observed when contrarians sit at the
highly connected elements. The same qualitative results are obtained for
artificially generated networks as well as two real ones, namely, the Routers
of the Internet and a neuronal network
Optogenetics and deep brain stimulation neurotechnologies
Brain neural network is composed of densely packed, intricately wired neurons whose activity patterns ultimately give rise to every behavior, thought, or emotion that we experience. Over the past decade, a novel neurotechnique, optogenetics that combines light and genetic methods to control or monitor neural activity patterns, has proven to be revolutionary in understanding the functional role of specific neural circuits. We here briefly describe recent advance in optogenetics and compare optogenetics with deep brain stimulation technology that holds the promise for treating many neurological and psychiatric disorders
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