392 research outputs found
The Full Automorphism Group of a Cyclic -gonal Surface
If is prime, a compact Riemann surface of genus is called
cyclic -gonal if it admits a cyclic group of automorphisms of order
such that the quotient space has genus 0. If in addition
is not normal in the full automorphism , then we call a non-normal
cyclic -gonal group. In the following we classify all non-normal -gonal
groups.Comment: 18 pages, 5 figure
Mary in Three Movements
Mary in Three Movements is an imagined account of how Mary might have felt and observed her experiences through the three most important events of both Christian and human existence, the conception, the birth, and finally the death of her son. I have attempted to remain true to the biblical Marian references which primarily speak to Mary as a young woman in a first century patriarchal Roman Jewish society. Therefore, I have taken these three events and put them to verse for mezzo-soprano with piano accompaniment. The accompanying paper outlines both the historical and musical context in which this project was framed as well as a brief analysis of the harmonic and textual structure
The minimal degree of plane models of double covers of smooth curves
If is a smooth curve such that the minimal degree of its plane models is
not too small compared with its genus, then has been known to be a double
cover of another smooth curve under some mild condition on the genera.
However there are no results yet for the minimal degrees of plane models of
double covers except some special cases. In this paper, we give upper and lower
bounds for the minimal degree of plane models of the double cover in terms
of the gonality of the base curve and the genera of and . In
particular, the upper bound equals to the lower bound in case is
hyperelliptic. We give an example of a double cover which has plane models of
degree equal to the lower bound.Comment: 13 pages; Sharpened the main result (Theorem 3.8); Corrected some
errors (Theorem 4.1); Final version to appear in JPA
Measuring the effectiveness of Seattleâs seawall enhancements on juvenile salmon-an acoustic perspective
Seattleâs waterfront is a key migration route for juvenile Pacific salmon including: Chinook (Oncorhynchus tshawytscha), pink (Oncorhynchus gorbuscha), and chum (Oncorhynchus keta). The hardwired tendency of these salmon to inhabit nearshore waters results in close association with coastline urbanization, including piers and seawalls. Part of Seattleâs seawall was replaced in 2018 with enhancements intended to aid the movement and distribution of juvenile salmon. These enhancements include: light-penetrating glass blocks in the overhanging sidewalk to decrease shade in the water below, a bench along the seawall to restore shallow water depths, and textured seawall and shelves for invertebrate colonization. The objective of our research is to study the effectiveness of the seawall enhancements on improving juvenile salmon habitat. We used a high-frequency acoustic camera mounted to the hull of a kayak to quantify salmon and other fish population densities along enhanced and original seawall habitats. Acoustic surveys during April-August 2019 compared salmon distributions and densities 1) between enhanced and original seawall habitat and a reference beach, 2) during day and night, 3) by overhead structures with varying ambient light, and 4) compared to fish densities from snorkel surveys. Preliminary results suggest higher salmon densities occur in 1) enhanced seawall sites compared to old seawall sites and the reference beach, 2) new pier enhanced corridor compared to old piers, and 3) nighttime enhanced corridor compared to daytime. Two main implications are that the seawall enhancements are important to juvenile salmon both during the day and night, and that juvenile salmon may still navigate more around pier ends along the old seawall that is not enhanced. Results from this study can be used to evaluate the cost-benefit of fish-friendly coastal armoring for the next phase of Seattleâs seawall and at similar sites throughout the world
Value-sharing of meromorphic functions on a Riemann surface
We present some results on two meromorphic functions from S to the Riemann
sphere sharing a number of values where S is a Riemann surface of one of the
following types: compact, compact minus finitely many points, the unit disk, a
torus, the complex plane.Comment: 15 page
Small linearly equivalent -sets and a construction of Beaulieu
Two -sets ( a finite group) are called linearly equivalent over a
commutative ring if the permutation representations and are
isomorphic as modules over the group algebra . Pairs of linearly equivalent
non-isomorphic -sets have applications in number theory and geometry. We
characterize the groups for which such pairs exist for any field, and give
a simple construction of these pairs. If is \Q, these are precisely the
non-cyclic groups. For any non-cyclic group, we prove that there exist -sets
which are non-isomorphic and \lineq over \Q, of cardinality \leq 3(#G)/2.
Also, we investigate a construction of P. Beaulieu which allows us to
construct pairs of transitive linearly equivalent -sets from arbitrary
-sets for an arbitrary group . We show that this construction works over
all fields and use it construct, for each finite set \mc P of primes,
-sets linearly equivalent over a field if and only if the
characteristic of lies in \mc P.Comment: v2: fixed proof of Lemma 2.
Infinite-genus surfaces and the universal Grassmannian
Correlation functions can be calculated on Riemann surfaces using the
operator formalism. The state in the Hilbert space of the free field theory on
the punctured disc, corresponding to the Riemann surface, is constructed at
infinite genus, verifying the inclusion of these surfaces in the Grassmannian.
In particular, a subset of the class of surfaces can be identified
with a subset of the Grassmannian. The concept of flux through the ideal
boundary is used to study the connection between infinite-genus surface and the
domain of string perturbation theory. The different roles of effectively closed
surfaces with Dirichlet boundaries in a more complete formulation of string
theory are identified.Comment: 14 pages, TeX, 3 figures. The July, 1995 version contains an expanded
introductio
Abelian Functions for Cyclic Trigonal Curves of Genus Four
We discuss the theory of generalized Weierstrass and functions
defined on a trigonal curve of genus four, following earlier work on the genus
three case. The specific example of the "purely trigonal" (or "cyclic
trigonal") curve is discussed in detail, including a list of some of the associated
partial differential equations satisfied by the functions, and the
derivation of an addition formulae.Comment: 23 page
Naturally occurring genotype 2b/1a hepatitis C virus in the United States
<p>Abstract</p> <p>Background</p> <p>Hepatitis C Virus (HCV) infected patients are frequently repeatedly exposed to the virus, but very few recombinants between two genotypes have been reported.</p> <p>Findings</p> <p>We describe the discovery of an HCV recombinant using a method developed in a United States clinical lab for HCV genotyping that employs sequencing of both 5' and 3' portions of the HCV genome. Over twelve months, 133 consecutive isolates were analyzed, and a virus from one patient was found with discordant 5' and 3' sequences suggesting it was a genotype 2b/1a recombinant. We ruled out a mixed infection and mapped a recombination point near the NS2/3 cleavage site.</p> <p>Conclusions</p> <p>This unique HCV recombinant virus described shares some features with other recombinant viruses although it is the only reported recombinant of a genotype 2 with a subtype 1a. This recombinant represents a conundrum for current clinical treatment guidelines, including treatment with protease inhibitors. This recombinant is also challenging to detect by the most commonly employed methods of genotyping that are directed primarily at the 5' structural portion of the HCV genome.</p
- âŠ