Omega time transmissions and receiving requirements

A short history is given of the development of dual VLF time transmission techniques. The theory of time recovery from the relative phase of the dual frequency transmission is presented. The transmission and receiving requirements for cycle identification and cycle ambiguity resolution are described. Finally, an experiment to test the capability of time transmission of the OMEGA system is propose

Engaged in Research/Achieving Balance: A Case Example of Teaching Research to Masters of Social Work Students

This article considers the use of participatory action research and Photovoice as a tool for engaging graduate level social work students in research education. Photovoice is an investigative tool that assists people in critically reflecting on the everyday social and political realities of their lives, enriching their understanding of their communities and the issues pertinent to them, while at the same time, giving them a voice from which to educate others on these issues. In the context of a group assignment, 26 social work students, enrolled in an introductory graduate research course, were asked to reflect upon the question, “What does balance look like for you in the MSW program?” Thirty-two photographs with captions were submitted and analyzed by class members for relevant themes. Balance was described as existing along a continuum from balanced to unbalanced and was comprised of four major themes: connection, nurturance, keeping perspective, and disengagement. Although this teaching strategy was not formally assessed, preliminary impressions are that students benefited from participating in the Photovoice activity

Uniqueness of Bessel models: the archimedean case

In the archimedean case, we prove uniqueness of Bessel models for general linear groups, unitary groups and orthogonal groups.Comment: 22 page

Effects of hatchery broodstock collection on adult Muskellunge populations

Muskellunge Esox masquinongy stocking programs throughout North America rely on the collection of wild adult Muskellunge to acquire gametes for hatchery propagation. The process of collecting, transporting, confining, handling, and spawning broodstock Muskellunge may cause mortality that could alter Muskellunge density, size structure, and population survival rates. We used long‐term Muskellunge capture‐recapture data collected from the Iowa Great Lakes and Clear Lake in northern Iowa, USA to estimate the number and proportion of Muskellunge captured annually and initial mortality rates resulting from broodstock collection. We also evaluated whether Muskellunge apparent survival rates differed between individuals used as broodstock and those that were not captured annually. Finally, we evaluated whether the number of initial mortalities or the number of individuals captured were related to annual population survival estimates. Collectively, 7,010 adult Muskellunge (3,896 males and 3,114 females) captures occurred between 2001‐2017 and population densities within a system ranged from 0.11 to 0.39 fish/ha. An average of 33% (range: 13% ‐76%) of the population was captured during broodstock operations annually. Between 0 and 28 (0.0000 to 0.0191 fish/ha) Muskellunge died at each hatchery annually and more males died than females (total of 150 males and 68 females; 3.9% and 2.2% of captured fish, respectively). However, annual mortalities were generally a low proportion of Muskellunge in the lake (\u3c2%; \u3c0.001 fish/ha). There was some evidence of size selective mortality, particularly for males, where larger individuals (875‐975 mm) were more likely to die, but we found no evidence to suggest that broodstock collection affected annual population survival estimates. Muskellunge broodstock mortality appears to act in a compensatory manner with natural mortality, and other sources of population mortality are more likely to have a greater effect on the population

Denominators of Eisenstein cohomology classes for GL_2 over imaginary quadratic fields

We study the arithmetic of Eisenstein cohomology classes (in the sense of G. Harder) for symmetric spaces associated to GL_2 over imaginary quadratic fields. We prove in many cases a lower bound on their denominator in terms of a special L-value of a Hecke character providing evidence for a conjecture of Harder that the denominator is given by this L-value. We also prove under some additional assumptions that the restriction of the classes to the boundary of the Borel-Serre compactification of the spaces is integral. Such classes are interesting for their use in congruences with cuspidal classes to prove connections between the special L-value and the size of the Selmer group of the Hecke character.Comment: 37 pages; strengthened integrality result (Proposition 16), corrected statement of Theorem 3, and revised introductio

Crystal constructions in Number Theory

Weyl group multiple Dirichlet series and metaplectic Whittaker functions can be described in terms of crystal graphs. We present crystals as parameterized by Littelmann patterns and we give a survey of purely combinatorial constructions of prime power coefficients of Weyl group multiple Dirichlet series and metaplectic Whittaker functions using the language of crystal graphs. We explore how the branching structure of crystals manifests in these constructions, and how it allows access to some intricate objects in number theory and related open questions using tools of algebraic combinatorics

Derivatives for smooth representations of GL(n,R) and GL(n,C)

The notion of derivatives for smooth representations of GL(n) in the p-adic case was defined by J. Bernstein and A. Zelevinsky. In the archimedean case, an analog of the highest derivative was defined for irreducible unitary representations by S. Sahi and called the "adduced" representation. In this paper we define derivatives of all order for smooth admissible Frechet representations (of moderate growth). The archimedean case is more problematic than the p-adic case; for example arbitrary derivatives need not be admissible. However, the highest derivative continues being admissible, and for irreducible unitarizable representations coincides with the space of smooth vectors of the adduced representation. In [AGS] we prove exactness of the highest derivative functor, and compute highest derivatives of all monomial representations. We prove exactness of the highest derivative functor, and compute highest derivatives of all monomial representations. We apply those results to finish the computation of adduced representations for all irreducible unitary representations and to prove uniqueness of degenerate Whittaker models for unitary representations, thus completing the results of [Sah89, Sah90, SaSt90, GS12].Comment: First version of this preprint was split into 2. The proofs of two theorems which are technically involved in analytic difficulties were separated into "Twisted homology for the mirabolic nilradical" preprint. All the rest stayed in v2 of this preprint. v3: version to appear in the Israel Journal of Mathematic

Behavioural syndrome in a solitary predator is independent of body size and growth rate.

Models explaining behavioural syndromes often focus on state-dependency, linking behavioural variation to individual differences in other phenotypic features. Empirical studies are, however, rare. Here, we tested for a size and growth-dependent stable behavioural syndrome in the juvenile-stages of a solitary apex predator (pike, Esox lucius), shown as repeatable foraging behaviour across risk. Pike swimming activity, latency to prey attack, number of successful and unsuccessful prey attacks was measured during the presence/absence of visual contact with a competitor or predator. Foraging behaviour across risks was considered an appropriate indicator of boldness in this solitary predator where a trade-off between foraging behaviour and threat avoidance has been reported. Support was found for a behavioural syndrome, where the rank order differences in the foraging behaviour between individuals were maintained across time and risk situation. However, individual behaviour was independent of body size and growth in conditions of high food availability, showing no evidence to support the state-dependent personality hypothesis. The importance of a combination of spatial and temporal environmental variation for generating growth differences is highlighted

Magnetic resonance imaging in patients with meningitis induced hearing loss

The aim of this multicentre study was to compare T1 with T2 weighted MRI scans of the labyrinth after meningitis and to investigate whether waiting with scanning improved the reliability of diagnosing an ongoing process such as cochlear osteogenesis. Forty-five patients were included who suffered from meningitis induced hearing loss (radiological imaging <1 year after meningitis). Twenty-one gadolinium enhanced T1 and 45 T2 weighted MRI scans were scored by two radiologists regarding the condition of the labyrinth. These radiological observations were compared with the condition of the cochlea as described during cochlear implantation. A higher percentage of agreement with surgery was found for T2 (both radiologists 73%) than for T1 weighted MRI scans (radiologist 1: 62%, radiologist 2: 67%), but this difference is not significant. There was no significant difference between early (0–3 months) and late (>3 months) scanning, showing that radiological imaging soon after meningitis allows early diagnosis without suffering from a lower agreement with surgical findings