529 research outputs found
Photon Number Resolving Detection with a Single-Photon Detector and Adaptive Storage Loop
Photon number resolving (PNR) measurements are beneficial or even necessary
for many applications in quantum optics. Unfortunately, PNR detectors are
usually large, slow, expensive, and difficult to operate. However, if the input
signal is multiplexed, photon "click" detectors, that lack an intrinsic photon
number resolving capability, can still be used to realize photon number
resolution. Here, we investigate the operation of a single click detector,
together with a storage line with tunable outcoupling. Using adaptive feedback
to adjust the storage outcoupling rate, the dynamic range of the detector can
in certain situations be extended by up to an order of magnitude relative to a
purely passive setup. An adaptive approach can thus allow for photon number
variance below the quantum shot noise limit under a wider range of conditions
than using a passive multiplexing approach. This can enable applications in
quantum enhanced metrology and quantum computing.Comment: 16 pages, 8 figure
Concerted adoption as an emerging strategy for digital transformation of healthcare - lessons from Australia, Canada, and England
Objectives: With an increasing focus on the digitalization of health and care settings, there is significant scope to learn from international approaches to promote concerted adoption of electronic health records. Materials and methods: We review three large-scale initiatives from Australia, Canada, and England, and extract common lessons for future health and social care transformation strategy. Results: In doing so, we discuss how, despite differences in contexts, concerted adoption enables sharing of experience and learning to streamline the digital transformation of health and care. Discussion and conclusion: Concerted adoption can be accelerated through building communities of expertise and partnerships promoting knowledge transfer and circulation of expertise, commonalities in geographical and cultural contexts, and commonalities in technological systems
Product Counterfeiting Legislation in the United States: A Review and Assessment of Characteristics, Remedies, and Penalties
Product counterfeiting crimes have detrimental effects on consumers, brand owners, public health, the economy, and even national security. Over time, as product counterfeiting crimes and the response to them have evolved, U.S. federal legislation has developed and state legislation has followed suit, but with considerable variation across the states. The purpose of this article is to place product counterfeiting in the context of intellectual property rights, provide a historical review of relevant federal legislation, and systematically examine the extent to which state laws differ in terms of characteristics, remedies, and penalties. Additionally, we calculate indices of civil and criminal protections that illustrate the overall strength of each stateâs legislative framework. Collectively, this assessment provides a solid foundation for understanding the development of product counterfeiting legislation and serves as a basis for advancing research, policy, and practice
Role of PKR and Type I IFNs in Viral Control during Primary and Secondary Infection
Type I interferons (IFNs) are known to mediate viral control, and also promote survival and expansion of virus-specific CD8+ T cells. However, it is unclear whether signaling cascades involved in eliciting these diverse cellular effects are also distinct. One of the best-characterized anti-viral signaling mechanisms of Type I IFNs is mediated by the IFN-inducible dsRNA activated protein kinase, PKR. Here, we have investigated the role of PKR and Type I IFNs in regulating viral clearance and CD8+ T cell response during primary and secondary viral infections. Our studies demonstrate differential requirement for PKR, in viral control versus elicitation of CD8+ T cell responses during primary infection of mice with lymphocytic choriomeningitis virus (LCMV). PKR-deficient mice mounted potent CD8+ T cell responses, but failed to effectively control LCMV. The compromised LCMV control in the absence of PKR was multifactorial, and linked to less effective CD8+ T cell-mediated viral suppression, enhanced viral replication in cells, and lower steady state expression levels of IFN-responsive genes. Moreover, we show that despite normal expansion of memory CD8+ T cells and differentiation into effectors during a secondary response, effective clearance of LCMV but not vaccinia virus required PKR activity in infected cells. In the absence of Type I IFN signaling, secondary effector CD8+ T cells were ineffective in controlling both LCMV and vaccinia virus replication in vivo. These findings provide insight into cellular pathways of Type I IFN actions, and highlight the under-appreciated importance of innate immune mechanisms of viral control during secondary infections, despite the accelerated responses of memory CD8+ T cells. Additionally, the results presented here have furthered our understanding of the immune correlates of anti-viral protective immunity, which have implications in the rational design of vaccines
Evaluation of the diagnostic accuracy of prototype rapid tests for human African trypanosomiasis
Peer reviewedPublisher PD
The FEAR network
Mitosis is governed by the oscillation of cyclin dependent kinase (CDK) activity and
ubiquitin-dependent proteolysis. Entry into mitosis is initiated by mitotic cyclin-CDK
activation. Anaphase onset occurs upon activation of the Anaphase Promoting
Complex/Cyclosome (APC/C), a ubiquitin ligase that promotes the destruction of the
anaphase inhibitor Securin. Destruction of Securin initiates chromosome segregation by
activation of the protease Separase, allowing it to cleave a subunit of the cohesin
complexes that hold the duplicated sister chromatids together. Upon completion of
nuclear division cells exit from mitosis, a process defined by the inactivation of CDKs,
disassembly of the mitotic spindle, and cytokinesis. In the budding yeast S. cerevisiae, a
signaling network known as the FEAR network is critical to ensure accurate anaphase
chromosome segregation and the integration of this process with other anaphase
events. Here, we summarize what is known about the regulation and function of the
FEAR network in budding yeast and discuss the potential for conserved FEAR network
functions in other eukaryotes.National Science Foundation (U.S.)Howard Hughes Medical Institute (Investigator
Experimental infections of Norway rats with avianâderived lowâpathogenic influenza A viruses
Influenza A viruses (IAVs) are a public-health, veterinary, and agricultural concern. Although wild birds are considered the primary reservoir hosts for most IAVs, wild-bird IAV strains are known to spill over into poultry, domestic or wild mammals, and humans. Occasionally, spillover events may result in adaptation or reassortment with other strains. Moreover, some IAV strains found in wild waterfowl mutate into highly pathogenic forms in poultry, causing tremendous economic losses. When domestic animals, wildlife, and humans dwell in close proximity to each other, such as may be the case with agricultural operations, wildlife may represent a potential risk for interspecies pathogen transmission. Understanding the pathways through which IAV strains could spillover from waterfowl reservoirs into humans and domestic animals is important for limiting the spread of IAVs, as well as developing biosecurity and containment procedures in livestock and poultry production. Experimental studies of common wild mammals in the U.S., bank voles (Myodes glareolus) in Europe and Asia, and black rats (Rattus rattus) in Japan have shown varying degrees of IAV susceptibility and/or transmission in these synanthropic species. While Norway rats (Rattus norvegicus) are ubiquitous throughout rural and urban areas of the world and have the ability to range between these areas, only limited investigations of this species have been conducted, and their role in IAV transmission has not been clearly established. The main objective of this study was to further characterize IAV infection in Norway rats using IAV strains derived from poultry and wild water birds
Ultra-high-Q resonances in plasmonic metasurfaces
Plasmonic nanostructures hold promise for the realization of ultra-thin
sub-wavelength devices, reducing power operating thresholds and enabling
nonlinear optical functionality in metasurfaces. However, this promise is
substantially undercut by absorption introduced by resistive losses, causing
the metasurface community to turn away from plasmonics in favour of alternative
material platforms (e.g., dielectrics) that provide weaker field enhancement,
but more tolerable losses. Here, we report a plasmonic metasurface with a
quality-factor (Q-factor) of 2340 in the telecommunication C band by exploiting
surface lattice resonances (SLRs), exceeding the record by an order of
magnitude. Additionally, we show that SLRs retain many of the same benefits as
localized plasmonic resonances, such as field enhancement and strong
confinement of light along the metal surface. Our results demonstrate that SLRs
provide an exciting and unexplored method to tailor incident light fields, and
could pave the way to flexible wavelength-scale devices for any optical
resonating application.Comment: 15 pages, includes supporting informatio
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