44,107 research outputs found
Positive Representations of Split Real Simply-laced Quantum Groups
We construct the positive principal series representations for
 where  is of
simply-laced type, parametrized by  where  is the
rank of . We describe explicitly the actions of the generators in
the positive representations as positive essentially self-adjoint operators on
a Hilbert space, and prove the transcendental relations between the generators
of the modular double. We define the modified quantum group
 of the
modular double and show that the representations of both parts of the modular
double commute weakly with each other, there is an embedding into a quantum
torus algebra, and the commutant contains its Langlands dual.Comment: Finalized published version. Introduction has been rewritten to
  reflect recent progress and references added. Some typos fixe
Hong Kong\u27s democratic movement and the making of China\u27s offshore civil society
Hong Kong\u27s civil society has remained vibrant since the sovereignty handover in 1997, thanks to an active defense by the democratic movement against Beijing\u27s attempts to control civil liberties. Hong Kong is becoming mainland China\u27s offshore civil society, serving as a free platform for information circulation and organizing among mainland activists and intellectuals
Synthesis and properties of nickel-cobalt-boron nanoparticles
morphous cobalt nickel boride nanoparticles were synthesised by chemical reduction synthesis in aqueous solution. Careful control of synthesis conditions and post reaction oxidation enabled the nanoparticles to be converted into a core-shell structure comprising of an amorphous Co–Ni–B core and an outer metal oxide sheet. These particles had interesting magnetic properties including saturation magnetisations and coercivities of the order of 80 emu/g and 170 Oe respectively, making them suitable for a potential use as an exchange-pinned magnetic material
Practitioner requirements for integrated Knowledge-Based Engineering in Product Lifecycle Management.
The effective management of knowledge as capital is considered essential to the
success of engineering product/service systems. As Knowledge Management (KM) and
Product Lifecycle Management (PLM) practice gain industrial adoption, the
question of functional overlaps between both the approaches becomes evident.
This article explores the interoperability between PLM and Knowledge-Based
Engineering (KBE) as a strategy for engineering KM. The opinion of key KBE/PLM
practitioners are systematically captured and analysed. A set of ranked business
functionalities to be fulfiled by the KBE/PLM systems integration is elicited.
The article provides insights for the researchers and the practitioners playing
both the user and development roles on the future needs for knowledge systems
based on PLM
The future of ischemic stroke: flow from prehospital neuroprotection to definitive reperfusion.
Recent advances in ischemic stroke enable a seamless transition of the patient flow from the prehospital setting to definitive reperfusion, without the arbitrary separation of therapeutic phases of ischemia based on time alone. In 2013, the framework to understand and directly address the pathophysiology of cerebral blood flow that determines the timeline or evolution of ischemia in an individual case is given. This continuum of flow and the homeostasis of brain perfusion balanced by collaterals may be captured with serial imaging. Ongoing imaging core laboratory activities permit large-scale measurement of angiographic and tissue biomarkers of ischemia. Prehospital neuroprotection has become a reality and may be combined with revascularization therapies. Recent studies confirm that image-guided thrombolysis may be achieved without restrictive time windows. Baseline imaging patterns may be used to predict response to therapy and serial imaging may discern recanalization and reperfusion. Advanced techniques, such as arterial spin-labeled MRI, may also report hyperperfusion associated with hemorrhagic transformation. Endovascular therapies, including novel stent retriever devices, may augment revascularization and angiographic core laboratories may define optimal reperfusion. Serial evaluation of collaterals and reperfusion may identify definitive reperfusion linked with good clinical outcome rather than imposing arbitrary definitions of effective recanalization. Reperfusion injury and hemorrhagic transformation of various types may be detailed to explain clinical outcomes. Similar approaches may be used in intracranial atherosclerosis where flow, and not the degree of luminal stenosis, is paramount. Fractional flow may now be measured with computational fluid dynamics to identify high-risk lesions that require revascularization to restore the equilibrium of antegrade and collateral perfusion. Serial perfusion imaging of such cases may also illustrate inadequate cerebral blood volume gradients that may be more informative than blood flow delay alone. In sum, the growing understanding of collateral perfusion throughout all stages of ischemic stroke provides a framework for the future of ischemic stroke
inPractice: a practical nursing package for clinical decisions
This paper examines the recent development of a computer-assisted learning program-in Practice-at the School of Health Science, in the University of Wales Swansea. The project, which began in 2001, was developed in close collaboration with The Meningitis Trust, the aim being to produce a software package to increase nursing students knowledge of meningitis-related illnesses, and to enhance their decision-making and problem-solving skills by using lifelike scenarios. It incorporates two multimedia meningitis modules incorporating the use of text, film, and sound, in which students are presented with information about the illness (symptoms, treatment etc.), and are required to use their knowledge to make decisions at various key points. A general discussion of decision-making theories and CAL design principles is presented, which has provided a foundation for the main design aspects of the package. This is followed by an outline of how the program was created to promote students application of knowledge and their decision-making and problem-solving skills. Results from an evaluation questionnaire are presented. Consideration is also given as to how the program can be extended
What mechanisms dominate the activity of Geminid Parent (3200) Phaethon?
A long-term sublimation model to explain how Phaethon could provide the
Geminid stream is proposed. We find that it would take  Myr or more for
Phaethon to lose all of its internal ice (if ever there was) in its present
orbit. Thus, if the asteroid moved from the region of a 5:2 or 8:3 mean motion
resonance with Jupiter to its present orbit less than  Myr ago, it may have
retained much of its primordial ice. The dust mantle on the sublimating body
should have a thickness of at least  m but the mantle could have been less
than  m thick  years ago. We find that the total gas production rate
could have been as large as  then, and the gas flow could
have been capable of lifting dust particles of up to a few centimeters in size.
Therefore, gas production during the past millennium could have been sufficient
to blow away enough dust particles to explain the entire Geminid stream. For
present-day Phaethon, the gas production is comparatively weak. But strong
transient gas release with a rate of  is
expected for its south polar region when Phaethon moves from  to
 mean anomaly near perihelion. Consequently, dust particles with radii
of  can be blown away to form a dust tail. In addition, we find
that the large surface temperature variation of  K near perihelion can
generate sufficiently large thermal stress to cause fracture of rocks or
boulders and provide an efficient mechanism to produce dust particles on the
surface. The time scale for this process should be several times longer than
the seasonal thermal cycle, thereby dominating the cycle of appearance of the
dust tail.Comment: 10 pages, 5 figures, Accepted for publication in Monthly Notices of
  the Royal Astronomical Societ
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