4,154 research outputs found
The post-fledging survival and movements of juvenile Barn Swallows (Hirundo rustica): an automated telemetry approach
For migratory songbirds, population dynamics are primarily influenced by juvenile or first year survival, but survival between fledging and fall migration is particularly important. Unfortunately, our knowledge of this post-fledging period is largely limited due to the difficulty of tracking juveniles outside the nest. For this thesis, I used automated radio telemetry to track the survival and post-fledging movements of 216 juvenile Barn Swallows (Hirundo rustica) from fledging up until departure for autumn migration in 2016-2017. Average apparent survival was 42% for both broods and nestlings in better body condition had higher survival. Nestlings from second broods migrated 21 days younger and moved less overall during the post-fledging period but had significantly higher daily post-fledging movements suggesting they might be trying to compensate for their shorter time near the breeding grounds. My results suggest that the post-fledging period is a critical period of survival and exploration for juvenile Barn Swallows
L-Visibility Drawings of IC-planar Graphs
An IC-plane graph is a topological graph where every edge is crossed at most
once and no two crossed edges share a vertex. We show that every IC-plane graph
has a visibility drawing where every vertex is an L-shape, and every edge is
either a horizontal or vertical segment. As a byproduct of our drawing
technique, we prove that an IC-plane graph has a RAC drawing in quadratic area
with at most two bends per edge
Solar flares and their associated processes
The evolution of the solar neutrino flux which is described by the wave
function
is examined. Our treatment of the problem holds for any standard model (SM)
extensions possessing nonzero dipole magnetic and anapole moments. When the
solar neutrino flux moves through the solar flare (SF) region in the preflare
period, then it undergoes the additional (compared with the SM) resonance
conversions. As a result, the weakening the electron neutrinos flux takes
place. On the other hand, existence of the additional resonances lead to
appearance of the and neutrinos
that could be detected by the terrestrial detectors.
The hypothesis of the -induced -decays is also discussed.
According to it, before the large SF, decreasing the -decay rate for
some elements takes place. The possible influence of the electron antineutrino
flux produced in the superflares on the regime of the hypothetical georeactor
is considered.Comment: 11 pages. arXiv admin note: text overlap with arXiv:hep-ph/0401221 by
other author
Onset of T=0 Pairing and Deformations in High Spin States of the N=Z Nucleus 48Cr
The yrast line of the N=Z nucleus 48Cr is studied up to high spins by means
of the cranked Hartree-Fock-Bogoliubov method including the T=0 and T=1 isospin
pairing channels. A Skyrme force is used in the mean-field channel together
with a zero-range density-dependent interaction in the pairing channels. The
extensions of the method needed to incorporate the neutron-proton pairing are
summarized. The T=0 pairing correlations are found to play a decisive role for
deformation properties and excitation energies above 16hbar which is the
maximum spin that can be obtained in the f7/2 subshell.Comment: LaTeX, 4 ps figure
Visibility Representations of Boxes in 2.5 Dimensions
We initiate the study of 2.5D box visibility representations (2.5D-BR) where
vertices are mapped to 3D boxes having the bottom face in the plane and
edges are unobstructed lines of sight parallel to the - or -axis. We
prove that: Every complete bipartite graph admits a 2.5D-BR; The
complete graph admits a 2.5D-BR if and only if ; Every
graph with pathwidth at most admits a 2.5D-BR, which can be computed in
linear time. We then turn our attention to 2.5D grid box representations
(2.5D-GBR) which are 2.5D-BRs such that the bottom face of every box is a unit
square at integer coordinates. We show that an -vertex graph that admits a
2.5D-GBR has at most edges and this bound is tight. Finally,
we prove that deciding whether a given graph admits a 2.5D-GBR with a given
footprint is NP-complete. The footprint of a 2.5D-BR is the set of
bottom faces of the boxes in .Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Inviscid limit of the active interface equations
We present a detailed solution of the active interface equations in the
inviscid limit. The active interface equations were previously introduced as a
toy model of membrane-protein systems: they describe a stochastic interface
where growth is stimulated by inclusions which themselves move on the
interface. In the inviscid limit, the equations reduce to a pair of coupled
conservation laws. After discussing how the inviscid limit is obtained, we turn
to the corresponding Riemann problem: the solution of the set of conservation
laws with discontinuous initial condition. In particular, by considering two
physically meaningful initial conditions, a giant trough and a giant peak in
the interface, we elucidate the generation of shock waves and rarefaction fans
in the system. Then, by combining several Riemann problems, we construct an
oscillating solution of the active interface with periodic boundaries
conditions. The existence of this oscillating state reflects the reciprocal
coupling between the two conserved quantities in our system.Comment: 22 pages, 11 figure
Molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) myostatin gene
Background: Myostatin (MSTN) is a member of the transforming growth factor-β superfamily that negatively regulates growth of skeletal muscle tissue. The gene encoding for the MSTN peptide is a consolidate candidate for the enhancement of productivity in terrestrial livestock. This gene potentially represents an important target for growth improvement of cultured finfish.\ud
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Results: Here we report molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) MSTN-1 gene. The barramundi MSTN-1 was encoded by three exons 379, 371 and 381 bp in length and translated into a 376-amino acid peptide. Intron 1 and 2 were 412 and 819 bp in length and presented typical GT...AG splicing sites. The upstream region contained cis-regulatory elements such as TATA-box and E-boxes. A first assessment of sequence variability suggested that higher mutation rates are found in the 5' flanking region with several SNP's present in this species. A putative micro RNA target site has also been observed in the 3'UTR (untranslated region) and is highly conserved across teleost fish. The deduced amino acid sequence was conserved across vertebrates and exhibited characteristic conserved putative functional residues including a cleavage motif of proteolysis (RXXR), nine cysteines and two glycosilation sites. A qualitative analysis of the barramundi MSTN-1 expression pattern revealed that, in adult fish, transcripts are differentially expressed in various tissues other than skeletal muscles including gill, heart, kidney, intestine, liver, spleen, eye, gonad and brain.\ud
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Conclusion: Our findings provide valuable insights such as sequence variation and genomic information which will aid the further investigation of the barramundi MSTN-1 gene in association with growth. The finding for the first time in finfish MSTN of a miRNA target site in the 3'UTR provides an opportunity for the identification of regulatory mutations on the expression of this gene
Dynamical density functional theory for interacting Brownian particles: stochastic or deterministic?
We aim to clarify confusions in the literature as to whether or not dynamical
density functional theories for the one-body density of a classical Brownian
fluid should contain a stochastic noise term. We point out that a stochastic as
well as a deterministic equation of motion for the density distribution can be
justified, depending on how the fluid one-body density is defined -- i.e.
whether it is an ensemble averaged density distribution or a spatially and/or
temporally coarse grained density distribution.Comment: 10 pages, 1 figure, to be submitted to Journal of Physics A:
Mathematical and Genera
The Chemical Compositions of the Type II Cepheids -- The BL Her and W Vir Variables
Abundance analyses from high-resolution optical spectra are presented for 19
Type II Cepheids in the Galactic field. The sample includes both short-period
(BL Her) and long-period (W Vir) stars. This is the first extensive abundance
analysis of these variables. The C, N, and O abundances with similar spreads
for the BL Her and W Vir show evidence for an atmosphere contaminated with
-process and CN-cycling products. A notable anomaly of the BL Her
stars is an overabundance of Na by a factor of about five relative to their
presumed initial abundances. This overabundance is not seen in the W Vir stars.
The abundance anomalies running from mild to extreme in W Vir stars but not
seen in the BL Her stars are attributed to dust-gas separation that provides an
atmosphere deficient in elements of high condensation temperature, notably Al,
Ca, Sc, Ti, and -process elements. Such anomalies have previously been seen
among RV Tau stars which represent a long-period extension of the variability
enjoyed by the Type II Cepheids. Comments are offered on how the contrasting
abundance anomalies of BL Her and W Vir stars may be explained in terms of the
stars' evolution from the blue horizontal branch.Comment: 41 pages including 11 figures and 4 tables; Accepted for publication
in Ap
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