126 research outputs found
City Open Data Policies
The capture and analysis of data is transforming the 21st Century. As society becomes more data driven, data has the ability to drive the bottom line for private companies and help the public sector to define where and how services can best be delivered. In City Open Data Policies: Learning by Doing, the National League of Cities identifies how cities can take advantage of the opportunities presented by open data initiatives.SUMMARY OF RECOMMENDATIONSLeadership: Political support stands out as one of the key requirements to implementing a successful open data project.Appropriate Legislation: Enacting legislation or formal policies is a crucial step toward ensuring the growth and sustainability of open data portals. Funding: Open data initiatives do not require high levels of funding. It is, however, important that the programs have their own budget line items where resources are specifically allocated. Technical Approach: Leading U.S. cities rely on commercial platforms that facilitate the implementation of open data initiatives, provide technical expertise, and ensure 24/7 customer support, often at a lower cost than providing these services in-house. Stakeholder Involvement: Open data is a two-way process. It is, therefore, essential to encourage participation and engagement among multiple stakeholders including: community members; non-profits; universities; the press; businesses; city departments; and other levels of government. Many cities adopt a flexible, and usually informal, approach to interact with the stakeholders. Measuring Success: Developing evaluation tools should be an integral part of any future open data policies
On Interferometric Duality in Multibeam Experiments
We critically analyze the problem of formulating duality between fringe
visibility and which-way information, in multibeam interference experiments. We
show that the traditional notion of visibility is incompatible with any
intuitive idea of complementarity, but for the two-beam case. We derive a
number of new inequalities, not present in the two-beam case, one of them
coinciding with a recently proposed multibeam generalization of the inequality
found by Greenberger and YaSin. We show, by an explicit procedure of
optimization in a three-beam case, that suggested generalizations of Englert's
inequality, do not convey, differently from the two-beam case, the idea of
complementarity, according to which an increase of visibility is at the cost of
a loss in path information, and viceversa.Comment: 26 pages, 1 figure, substantial changes in the text, new material has
been added in Section 3. Version to appear in J.Phys.
The Physics of Maxwell's demon and information
Maxwell's demon was born in 1867 and still thrives in modern physics. He
plays important roles in clarifying the connections between two theories:
thermodynamics and information. Here, we present the history of the demon and a
variety of interesting consequences of the second law of thermodynamics, mainly
in quantum mechanics, but also in the theory of gravity. We also highlight some
of the recent work that explores the role of information, illuminated by
Maxwell's demon, in the arena of quantum information theory.Comment: 24 pages, 13 figures. v2: some refs added, figs improve
Quantum key distribution without alternative measurements
Entanglement swapping between Einstein-Podolsky-Rosen (EPR) pairs can be used
to generate the same sequence of random bits in two remote places. A quantum
key distribution protocol based on this idea is described. The scheme exhibits
the following features. (a) It does not require that Alice and Bob choose
between alternative measurements, therefore improving the rate of generated
bits by transmitted qubit. (b) It allows Alice and Bob to generate a key of
arbitrary length using a single quantum system (three EPR pairs), instead of a
long sequence of them. (c) Detecting Eve requires the comparison of fewer bits.
(d) Entanglement is an essential ingredient. The scheme assumes reliable
measurements of the Bell operator.Comment: REVTeX, 5 pages, 2 figures. Published version with some comment
Quantum Distribution of Gaussian Keys with Squeezed States
A continuous key distribution scheme is proposed that relies on a pair of
canonically conjugate quantum variables. It allows two remote parties to share
a secret Gaussian key by encoding it into one of the two quadrature components
of a single-mode electromagnetic field. The resulting quantum cryptographic
information vs disturbance tradeoff is investigated for an individual attack
based on the optimal continuous cloning machine. It is shown that the
information gained by the eavesdropper then simply equals the information lost
by the receiver.Comment: 5 pages, RevTe
Conceptual Inadequacy of the Shannon Information in Quantum Measurements
In a classical measurement the Shannon information is a natural measure of
our ignorance about properties of a system. There, observation removes that
ignorance in revealing properties of the system which can be considered to
preexist prior to and independent of observation. Because of the completely
different root of a quantum measurement as compared to a classical measurement
conceptual difficulties arise when we try to define the information gain in a
quantum measurement using the notion of Shannon information. The reason is
that, in contrast to classical measurement, quantum measurement, with very few
exceptions, cannot be claimed to reveal a property of the individual quantum
system existing before the measurement is performed.Comment: 11 pages, 5 figures, important Ref. [6] is now cited in all
appropriate place
Quantum information with continuous variables
Quantum information is a rapidly advancing area of interdisciplinary
research. It may lead to real-world applications for communication and
computation unavailable without the exploitation of quantum properties such as
nonorthogonality or entanglement. We review the progress in quantum information
based on continuous quantum variables, with emphasis on quantum optical
implementations in terms of the quadrature amplitudes of the electromagnetic
field.Comment: accepted for publication in Reviews of Modern Physic
Gene content evolution in the arthropods
Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity
Phase I interim results of a phase I/II study of the IgG-Fc fusion COVID-19 subunit vaccine, AKS-452
To address the coronavirus disease 2019 (COVID-19) pandemic caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a recombinant subunit vaccine, AKS-452, is being developed comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain (SP/RBD) antigen and human IgG1 Fc emulsified in the water-in-oil adjuvant, Montanide™ ISA 720. A single-center, open-label, phase I dose-finding and safety study was conducted with 60 healthy adults (18–65 years) receiving one or two doses 28 days apart of 22.5 µg, 45 µg, or 90 µg of AKS-452 (i.e., six cohorts, N = 10 subjects per cohort). Primary endpoints were safety and reactogenicity and secondary endpoints were immunogenicity assessments. No AEs ≥ 3, no SAEs attributable to AKS-452, and no SARS-CoV-2 viral infections occurred during the study. Seroconversion rates of anti-SARS-CoV-2 SP/RBD IgG titers in the 22.5, 45, and 90 µg cohorts at day 28 were 70%, 90%, and 100%, respectively, which all increased to 100% at day 56 (except 89% for the single-dose 22.5 µg cohort). All IgG titers were Th1-isotype skewed and efficiently bound mutant SP/RBD from several SARS-CoV-2 variants with strong neutralization potencies of live virus infection of cells (including alpha and delta variants). The favorable safety and immunogenicity profiles of this phase I study (ClinicalTrials.gov: NCT04681092) support phase II initiation of this room-temperature stable vaccine that can be rapidly and inexpensively manufactured to serve vaccination at a global scale without the need of a complex distribution or cold chain
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