951 research outputs found
Minnesota Tuning Project: Biology and Graphic Design
Within the tuning methodology, a key step is the utilization of a consultative survey. The objectives established in the Bologna process for the tuning survey “include gleaning current perspectives on the diversity of practice and commonality of knowledge across borders and traditions, and seeking a simple and accessible language to create a scaffolding on which the various degrees can work in comfort and trust” (Adelman, 2009, p. 49). The Minnesota tuning surveys sought the consultation of previous graduates, current students, employers of graduates, and academic faculty for each of the disciplines involved in tuning
Spatial distribution of Cherenkov radiation in periodic dielectric media
The nontrivial dispersion relation of a periodic medium affects both the
spectral and the spatial distribution of Cherenkov radiation. We present a
theory of the spatial distribution of Cherenkov radiation in the far-field zone
inside arbitrary three- and two-dimensional dielectric media. Simple analytical
expressions for the far-field are obtained in terms of the Bloch mode
expansion. Numerical examples of the Cherenkov radiation in a two-dimensional
photonic crystal is presented. The developed analytical theory demonstrates
good agreement with numerically rigorous finite-difference time-domain
calculations.Comment: 14 pages, 5 figures, Journal of Optics A (in press
Making identity assurance and authentication strength work for federated infrastructures
In both higher Research and Education (R&E) as well as in research-/ e-infrastructures (in short: infrastructures), federated access and single sign-on by way of national federations, operated in most cases by NRENs, are used as a means to provide users with access to a variety of services. Whereas in national federations institutional accounts, e.g. provided by a university, are typically used to access services, many infrastructures also accept other sources of identity: provided by \u27\u27community identity providers\u27\u27, social identity providers, or governmental IDs. In order to assess and communicate the quality of identities being used and authentications being performed, so called Level of Assurance (LoA) frameworks are used. Because sophisticated LoA frameworks like NIST 800-63-3, Kantara IAF 1420 or eIDAS regulation are often considered too complex to be used in R&E scenarios, the REFEDS Assurance Suite, a more lightweight approach, has been developed. To select an appropriate assurance level, Service Providers need to weigh risks and potential harms in relation to the kind of service they offer. However, the management of risks is often implicitly assumed and little or no guidance to determine the appropriate assurance level is given. In this paper, first, common LoA frameworks and their relation to risk management are investigated. Following that, their components are compared against the REFEDS Assurance Suite using a graphical representation. The focus of this paper lies in providing guidance and best practices based on example scenarios for both Service Providers to request the appropriate REFEDS assurance level, as well as for Identity Provider operators on how to implement REFEDS assurance components
Fabrication and characterization of terahertz anisotropic anti-rod dimer planar metamaterials
The Immediate and Short-Term Effects of Transcutaneous Spinal Cord Stimulation and Peripheral Nerve Stimulation on Corticospinal Excitability
Rehabilitative interventions involving electrical stimulation show promise for neuroplastic recovery in people living with Spinal Cord Injury (SCI). However, the understanding of how stimulation interacts with descending and spinal excitability remain unclear. In this study we compared the immediate and short-term (within a few minutes) effects of pairing Transcranial Magnetic Stimulation (TMS) with transcutaneous Spinal Cord stimulation (tSCS) and Peripheral Nerve Stimulation (PNS) on Corticospinal excitability in healthy subjects. Three separate experimental conditions were assessed. In Experiment I, paired associative stimulation (PAS) was applied, involving repeated pairing of single pulses of TMS and tSCS, either arriving simultaneously at the spinal motoneurones (PAS0ms) or slightly delayed (PAS5ms). Corticospinal and spinal excitability, and motor performance, were assessed before and after the PAS interventions in 24 subjects. Experiment II compared the immediate effects of tSCS and PNS on corticospinal excitability in 20 subjects. Experiment III compared the immediate effects of tSCS with tSCS delivered at the same stimulation amplitude but modulated with a carrier frequency (in the kHz range) on corticospinal excitability in 10 subjects. Electromyography (EMG) electrodes were placed over the Tibialis Anterior (TA) soleus (SOL) and vastus medialis (VM) muscles and stimulation electrodes (cathodes) were placed on the lumbar spine (tSCS) and lateral to the popliteal fossa (PNS). TMS over the primary motor cortex (M1) was paired with tSCS or PNS to produce Motor Evoked Potentials (MEPs) in the TA and SOL muscles. Simultaneous delivery of repetitive PAS (PAS0ms) increased corticospinal excitability and H-reflex amplitude at least 5 min after the intervention, and dorsiflexion force was increased in a force-matching task. When comparing effects on descending excitability between tSCS and PNS, a subsequent facilitation in MEPs was observed following tSCS at 30-50 ms which was not present following PNS. To a lesser extent this facilitatory effect was also observed with HF- tSCS at subthreshold currents. Here we have shown that repeated pairing of TMS and tSCS can increase corticospinal excitability when timed to arrive simultaneously at the alpha-motoneurone and can influence functional motor output. These results may be useful in optimizing stimulation parameters for neuroplasticity in people living with SCI
Strengths and weaknesses of the acute care systems in the United Kingdom and the Netherlands: what can we learn from each other?
Background The demand on Emergency Departments and acute medical services is increasing internationally, creating pressure on health systems and negatively influencing the quality of delivered care. Visible consequences of the increased demand on acute services is crowding and queuing. This manifests as delays in the Emergency Departments, adverse clinical outcomes and poor patient experience. Overview Despite the similarities in the UK’s and Dutch health care systems, such as universal health coverage, there are differences in the number of patients presenting at the Emergency Departments and the burden of crowding between these countries. Given the similarities in funding, this paper explores the similarities and differences in the organisational structure of acute care in the UK and the Netherlands. In the Netherlands, less patients are seen at the ED than in England and the admission rate is higher. GPs and so-called GP-posts serve 24/7 as gatekeepers in acute care, but EDs are heterogeneously organised. In the UK, the acute care system has a number of different access points and the accessibility of GPs seems to be suboptimal. Acute ambulatory care may relieve the pressure from EDs and Acute Medical Units. In both countries the ageing population leads to a changing case mix at the ED with an increased amount of multimorbid patients with polypharmacy, requiring generalistic and multidisciplinary care. Conclusion The acute and emergency care in the Netherlands and the UK face similar challenges. We believe that each system has strengths that the other can learn from. The Netherlands may benefit from an acute ambulatory care system and the UK by optimizing the accessibility of GPs 24/7 and improving signposting for urgent care services. In both countries the changing case mix at the ED needs doctors who are superspecialists instead of subspecialists. Finally, to improve the organisation of health care, doctors need to be visible medical leaders and participate in the organisation of care
Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials
We review the basic physics behind light interaction with plasmonic
nanoparticles. The theoretical foundations of light scattering on one metallic
particle (a plasmonic monomer) and two interacting particles (a plasmonic
dimer) are systematically investigated. Expressions for effective particle
susceptibility (polarizability) are derived, and applications of these results
to plasmonic nanoantennas are outlined. In the long-wavelength limit, the
effective macroscopic parameters of an array of plasmonic dimers are
calculated. These parameters are attributable to an effective medium
corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial
where plasmonic monomers or dimers have the function of "meta-atoms". It is
shown that planar dimers consisting of rod-like particles generally possess
elliptical dichroism and function as atoms for planar chiral metamaterials. The
fabricational simplicity of the proposed rod-dimer geometry can be used in the
design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.
Xist and Tsix transcription dynamics is regulated by the X-to-autosome ratio and semistable transcriptional states
In female mammals, X chromosome inactivation (XCI) is a key process in the control of gene dosage compensation between Xlinked genes and autosomes. Xist and Tsix, two overlapping antisense-transcribed noncoding genes, are central elements of the X inactivation center (Xic) regulating XCI. Xist upregulation results in the coating of the entire X chromosome by Xist RNA in cis, whereas Tsix transcription acts as a negative regulator of Xist. Here, we generated Xist and Tsix reporter mouse embryonic stem (ES) cell lines to study the genetic and dynamic regulation of these genes upon differentiation. Our results revealed mutually antagonistic roles for Tsix on Xist and vice versa and indicate the presence of semistable transcriptional states of the Xic locus predicting the outcome of XCI. These transcriptional states are instructed by the X-t
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