136 research outputs found
Non-asymptotic analysis of quantum metrology protocols beyond the Cramér-Rao bound
Many results in the quantum metrology literature use the Cramér-Rao bound and the Fisher information to compare different quantum estimation strategies. However, there are several assumptions that go into the construction of these tools, and these limitations are sometimes not taken into account. While a strategy that utilises this method can considerably simplify the problem and is valid asymptotically, to have a rigorous and fair comparison we need to adopt a more general approach. In this work we use a methodology based on Bayesian inference to understand what happens when the Cramér-Rao bound is not valid. In particular we quantify the impact of these restrictions on the overall performance of a wide range of schemes including those commonly employed for the estimation of optical phases. We calculate the number of observations and the minimum prior knowledge that are needed such that the Cramér-Rao bound is a valid approximation. Since these requirements are state-dependent, the usual conclusions that can be drawn from the standard methods do not always hold when the analysis is more carefully performed. These results have important implications for the analysis of theory and experiments in quantum metrology
Synthesis and in vitro evaluation of a multifunctional and surface-switchable nanoemulsion platform
We present a multifunctional nanoparticle platform that has targeting moieties shielded by a matrix metalloproteinase-2 (MMP2) cleavable PEG coating. Upon incubation with MMP2 this surface-switchable coating is removed and the targeting ligands become available for binding. The concept was evaluated in vitro using biotin and αvβ3-integrin-specific RGD-peptide functionalized nanoparticles.National Heart, Lung, and Blood InstituteNational Institutes of Health (U.S.) (Program of Excellence in Nanotechnology (PEN) Award Contract HHSN268201000045C
Quantum interferometry with three-dimensional geometry
Quantum interferometry uses quantum resources to improve phase estimation
with respect to classical methods. Here we propose and theoretically
investigate a new quantum interferometric scheme based on three-dimensional
waveguide devices. These can be implemented by femtosecond laser waveguide
writing, recently adopted for quantum applications. In particular, multiarm
interferometers include "tritter" and "quarter" as basic elements,
corresponding to the generalization of a beam splitter to a 3- and 4-port
splitter, respectively. By injecting Fock states in the input ports of such
interferometers, fringe patterns characterized by nonclassical visibilities are
expected. This enables outperforming the quantum Fisher information obtained
with classical fields in phase estimation. We also discuss the possibility of
achieving the simultaneous estimation of more than one optical phase. This
approach is expected to open new perspectives to quantum enhanced sensing and
metrology performed in integrated photonic.Comment: 7 pages (+4 Supplementary Information), 5 figure
Standardized NEON organismal data for biodiversity research
Understanding patterns and drivers of species distribution and abundance, and thus biodiversity, is a core goal of ecology. Despite advances in recent decades, research into these patterns and processes is currently limited by a lack of standardized, high-quality, empirical data that span large spatial scales and long time periods. The NEON fills this gap by providing freely available observational data that are generated during robust and consistent organismal sampling of several sentinel taxonomic groups within 81 sites distributed across the United States and will be collected for at least 30 years. The breadth and scope of these data provide a unique resource for advancing biodiversity research. To maximize the potential of this opportunity, however, it is critical that NEON data be maximally accessible and easily integrated into investigators\u27 workflows and analyses. To facilitate its use for biodiversity research and synthesis, we created a workflow to process and format NEON organismal data into the ecocomDP (ecological community data design pattern) format that were available through the ecocomDP R package; we then provided the standardized data as an R data package (neonDivData). We briefly summarize sampling designs and data wrangling decisions for the major taxonomic groups included in this effort. Our workflows are open-source so the biodiversity community may: add additional taxonomic groups; modify the workflow to produce datasets appropriate for their own analytical needs; and regularly update the data packages as more observations become available. Finally, we provide two simple examples of how the standardized data may be used for biodiversity research. By providing a standardized data package, we hope to enhance the utility of NEON organismal data in advancing biodiversity research and encourage the use of the harmonized ecocomDP data design pattern for community ecology data from other ecological observatory networks
The elusive Heisenberg limit in quantum enhanced metrology
We provide efficient and intuitive tools for deriving bounds on achievable
precision in quantum enhanced metrology based on the geometry of quantum
channels and semi-definite programming. We show that when decoherence is taken
into account, the maximal possible quantum enhancement amounts generically to a
constant factor rather than quadratic improvement. We apply these tools to
derive bounds for models of decoherence relevant for metrological applications
including: dephasing,depolarization, spontaneous emission and photon loss.Comment: 10 pages, 4 figures, presentation imporved, implementation of the
semi-definite program finding the precision bounds adde
Synthesis and in vitro evaluation of a multifunctional and surface-switchable nanoemulsion platform
We present a multifunctional nanoparticle platform that has targeting moieties shielded by a matrix metalloproteinase-2 (MMP2) cleavable PEG coating. Upon incubation with MMP2 this surface-switchable coating is removed and the targeting ligands become available for binding. The concept was evaluated in vitro using the biotin and αvβ3-integrin-specific RGD-peptide functionalized nanoparticles
A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins
Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin similar to 100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants
The use of chemical markers for the identification of farm escapees in feral mink populations
Harnessing the NEON data revolution to advance open environmental science with a diverse and data-capable community
It is a critical time to reflect on the National Ecological Observatory Network (NEON) science to date as well as envision what research can be done right now with NEON (and other) data and what training is needed to enable a diverse user community. NEON became fully operational in May 2019 and has pivoted from planning and construction to operation and maintenance. In this overview, the history of and foundational thinking around NEON are discussed. A framework of open science is described with a discussion of how NEON can be situated as part of a larger data constellation—across existing networks and different suites of ecological measurements and sensors. Next, a synthesis of early NEON science, based on >100 existing publications, funded proposal efforts, and emergent science at the very first NEON Science Summit (hosted by Earth Lab at the University of Colorado Boulder in October 2019) is provided. Key questions that the ecology community will address with NEON data in the next 10 yr are outlined, from understanding drivers of biodiversity across spatial and temporal scales to defining complex feedback mechanisms in human–environmental systems. Last, the essential elements needed to engage and support a diverse and inclusive NEON user community are highlighted: training resources and tools that are openly available, funding for broad community engagement initiatives, and a mechanism to share and advertise those opportunities. NEON users require both the skills to work with NEON data and the ecological or environmental science domain knowledge to understand and interpret them. This paper synthesizes early directions in the community’s use of NEON data, and opportunities for the next 10 yr of NEON operations in emergent science themes, open science best practices, education and training, and community building
Industrial implementation as a research work keynote of the Electrical Drives and Electrical Machines Department
W artykule przedstawiono aktualną ofertę badawczo wdrożeniową Katedry Napędów i Maszyn Elektrycznych Politechniki Lubelskiej. Ofertę tą przedstawiono na tle historycznej działalności Katedry kierowanej przez poprzednich kierowników. Podkreślono praktyczny charakter badań. Wyróżniono kierunki prac wdrożeniowych obejmujących m.in. napędy i sterowanie dźwigów osobowych, układy elektromaszynowe zasilane ze źródeł fotowoltaicznych i współpracę elektrowni wiatrowych z siecią elektroenergetyczną. Zaznaczono również aktywny udział pracowników i doktorantów katedry w dostosowywaniu oferty dydaktycznej do potrzeb rynku i kształcenie kadr na studiach podyplomowych.The paper presents current offer of the implementation research at Electrical Drives and Electrical Machines Department at Lublin University of Technology. The offer was presented on the background of the historic activity of Department led by former managers. The practical nature of the research was emphasized. Implementation directions including, i.e. drives and passenger lifts control, electromechanical systems powered by renewable solar and wind power cooperation to the grid were distinguished. The active participation of the department employees and PhD students in adapting the educational offer to the market needs, as well as postgraduate staff training were also noticed
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