2,594 research outputs found
Gene Flow Between Great Lakes Region Populations of the Canadian Tiger Swallowtail Butterfly, \u3ci\u3ePapilio Canadensis\u3c/i\u3e, Near the Hybrid Zone With \u3ci\u3eP. Glaucus\u3c/i\u3e (Lepidoptera: Papilionidae)
Papilio canadensis were sampled from three locations on either side of Lake Michigan to study gene flow near and through a butterfly hybrid zone. Allele frequencies at four polymorphic enzyme loci, as indicated by allozyme electrophoresis, were similar in all samples. Values for FST were close to zero, indicating that gene flow is high among these populations, even when separated by Lake Michigan. We developed a mitochondrial DNA marker with diagnostic differences between P. canadensis and its parapatric sister species Papilio glaucus, based on PCR-RFLP. P. glaucus haplotypes of this mtDNA marker and P. glaucus alleles of a diagnostic allozyme locus (PGD) were found in P. canadensis populations sampled in Michigan’s Lower Peninsula but not in the Upper Peninsula or Northern Minnesota. The presence of P. glaucus alleles in P. canadensis populations could be due to introgression through hybridization, or could be remnants of a P. glaucus population that was inundated by an influx of P. canadensis alleles
Pirates and Librarians: Big Media, Technology, and the Role of Liberal Education
The widespread appearance of computers in libraries during the early 1990s elicited a debate among those who welcomed new technologies and those who perceived such changes as a threat to the traditional role of academic libraries and the values of liberal education. At the same time, increasing consolidation of major media channels—including sources of scholarly communication—has allowed a small number of corporations to control distribution and access to the materials libraries offer, through tools such as licensing fees, copyright restrictions, and digital rights management. In response to these barriers, librarians and educators have embraced open access publishing and Creative Commons licensing as viable alternatives. Some go further in their struggle to separate content from its proprietors, through channels such as torrent sites that undermine conventional notions of ownership. This paper will argue that restricting information and denying access to resources without addressing the systemic failure of affordable access weakens critical thinking and threatens the mission of liberal education. By pursuing new models for scholarly communication and resource sharing, libraries can both reassert control over their collections and help support the mission of libera
Magnetic field--induced modification of selection rules for Rb D line monitored by selective reflection from a vapor nanocell
Magnetic field-induced giant modification of the probabilities of five
transitions of of Rb and
three transitions of of Rb
forbidden by selection rules for zero magnetic field has been observed
experimentally and described theoretically for the first time. For the case of
excitation with circularly-polarized () laser radiation, the
probability of transition becomes
the largest among the seventeen transitions of Rb group, and the probability of transition becomes the largest among the nine transitions of
Rb group, in a wide range of magnetic
field 200 -- 1000 G. Complete frequency separation of individual Zeeman
components was obtained by implementation of derivative selective reflection
technique with a 300 nm-thick nanocell filled with Rb, allowing formation of
narrow optical resonances. Possible applications are addressed. The theoretical
model is perfectly consistent with the experimental results.Comment: 6 pages, 5 figure
Critical Information Literacy and the Technology of Control: The Case of Armenia
As direct providers of information literacy, librarians can help patrons analyze the social and economic forces involved in the creation and use of information. This chapter will discuss why critical information literacy and critical pedagogy are especially important in the Armenian context, with its unique historical, cultural, and geopolitical concerns. The authors will document how the Armenian government has used cutting-edge Internet controls to block online content or misdirect users. We will also examine how Armenians perceive the independence of their available media and explore current efforts by telecom, publishing, and governmental concerns to restrict Internet freedom. The authors suggest ways for users to regain control over restricted media and argue that an open online culture cannot exist without local self-determination and a basic human right to produce and share information
Supervised learning with quantum enhanced feature spaces
Machine learning and quantum computing are two technologies each with the
potential for altering how computation is performed to address previously
untenable problems. Kernel methods for machine learning are ubiquitous for
pattern recognition, with support vector machines (SVMs) being the most
well-known method for classification problems. However, there are limitations
to the successful solution to such problems when the feature space becomes
large, and the kernel functions become computationally expensive to estimate. A
core element to computational speed-ups afforded by quantum algorithms is the
exploitation of an exponentially large quantum state space through controllable
entanglement and interference. Here, we propose and experimentally implement
two novel methods on a superconducting processor. Both methods represent the
feature space of a classification problem by a quantum state, taking advantage
of the large dimensionality of quantum Hilbert space to obtain an enhanced
solution. One method, the quantum variational classifier builds on [1,2] and
operates through using a variational quantum circuit to classify a training set
in direct analogy to conventional SVMs. In the second, a quantum kernel
estimator, we estimate the kernel function and optimize the classifier
directly. The two methods present a new class of tools for exploring the
applications of noisy intermediate scale quantum computers [3] to machine
learning.Comment: Fixed typos, added figures and discussion about quantum error
mitigatio
Use and Awareness of Library Services among Faculty at Two Armenian Universities
This study surveyed instructional faculty at two Armenian universities to determine use and awareness of academic library services or resources including reference, interlibrary loan, subscription databases, subject liaisons, and more. A minority of respondents reported making frequent use of the services investigated, with usage varying according to such factors as academic rank, length of employment, and full- or part-time status. Many participants also had suggestions for services not available at their libraries. These results help illuminate user preferences among faculty at these universities and could help librarians at similar institutions identify underutilized resources to promote or new services to offer
Adaptive versus non-adaptive strategies for quantum channel discrimination
We provide a simple example that illustrates the advantage of adaptive over
non-adaptive strategies for quantum channel discrimination. In particular, we
give a pair of entanglement-breaking channels that can be perfectly
discriminated by means of an adaptive strategy that requires just two channel
evaluations, but for which no non-adaptive strategy can give a perfect
discrimination using any finite number of channel evaluations.Comment: 11 page
Validity of discrepancy criteria for identifying children with developmental language disorders
Empirical data from two studies address the clinical validity of discrepancy criteria for identification of children with developmental language disorders (DLD). Study 1 involved 256 preschoolers clinically defined as DLD and meeting inclusionary criteria for normal hearing, intellectual, neurological, and psychiatric status. Application of alternative psychometrically derived discrepancy criteria identified only 40% to 60% of the clinically defined group as language disordered. Study 2 applied nonverbal IQ-language performance discrepancy criteria to 368 eight-year-old, randomly selected control subjects, resulting in over 45% of the controls being identified as DLD. Factors contributing to underidentification in Study 1 and overidentification in Study 2 are discussed, raising questions regarding the validity of discrepancy criteria for identification of DLD children
Wightman function and vacuum fluctuations in higher dimensional brane models
Wightman function and vacuum expectation value of the field square are
evaluated for a massive scalar field with general curvature coupling parameter
subject to Robin boundary conditions on two codimension one parallel branes
located on -dimensional background spacetime
with a warped internal space . The general case of different Robin
coefficients on separate branes is considered. The application of the
generalized Abel-Plana formula for the series over zeros of combinations of
cylinder functions allows us to extract manifestly the part due to the bulk
without boundaries. Unlike to the purely AdS bulk, the vacuum expectation value
of the field square induced by a single brane, in addition to the distance from
the brane, depends also on the position of the brane in the bulk. The brane
induced part in this expectation value vanishes when the brane position tends
to the AdS horizon or AdS boundary. The asymptotic behavior of the vacuum
densities near the branes and at large distances is investigated. The
contribution of Kaluza-Klein modes along is discussed in various
limiting cases. As an example the case is considered,
corresponding to the bulk with one compactified dimension. An
application to the higher dimensional generalization of the Randall-Sundrum
brane model with arbitrary mass terms on the branes is discussed.Comment: 25 pages, 2 figures, discussion added, accepted for publication in
Phys.Rev.
- …