169 research outputs found
Uterine Mast Cells and Immunoglobulin-E Antibody Responses During Clearance of \u3ci\u3eTritrichomonas foetus\u3c/i\u3e
We showed earlier that Tritrichomonas foetus–specific bovine immunoglobulin (Ig)G1 and IgA antibodies in uterine and vaginal secretions are correlated with clearance of this sexually transmitted infection. Eosinophils have been noted in previous studies of bovine trichomoniasis but the role of mast cells and IgE responses have not been reported. The hypothesis that IgE and mast cell degranulation play a role in clearance was tested in 25 virgin heifers inseminated experimentally and infected intravaginally with T. foetus strain D1 at estrus and cultured weekly. Groups were euthanatized at 3, 6, 9, or 12 weeks, when tissues were fixed and secretions were collected for culture and antibody analysis. Immunohistochemistry using a monoclonal antibody to a soluble lipophosphoglycan (LPG)–containing surface antigen (TF1.17) demonstrated antigen uptake by uterine epithelial cells. Lymphoid nodules were detected below antigen-positive epithelium. Little IgG2 antibody was detected but IgG1, IgA, IgM, and IgE T. foetus–specific antibodies increased in uterine secretions at weeks 6 and 9 after infection. This was inversely proportional to subepithelial mast cells numbers and most animals cleared the infection by the sampling time after the lowest mast cell count. Furthermore, soluble antigen was found in uterine epithelium above inductive sites (lymphoid nodules). Cross-linking of IgE on mast cells by antigen and perhaps LPG triggering appears to have resulted in degranulation. Released cytokines may account for production of predominantly Th2 (IgG1 and IgE) and IgA antibody responses, which are related to clearance of the infection
Hydrological, Sedimentological, and Meteorological Observations and Analysis on the Sagavanirktok River
The Dalton Highway near Deadhorse was closed twice during late March and early April 2015
because of extensive overflow from the Sagavanirktok River that flowed over the highway. That
spring, researchers from the Water and Environmental Research Center at the University of
Alaska Fairbanks (UAF) monitored the river conditions during breakup, which was characterized
by unprecedented flooding that overtopped and consequently destroyed several sections of the
Dalton Highway near Deadhorse. The UAF research team has monitored breakup conditions at
the Sagavanirktok River since that time. Given the magnitude of the 2015 flooding, the Alyeska
Pipeline Service Company started a long-term monitoring program within the river basin. In
addition, the Alaska Department of Transportation and Public Facilities (ADOT&PF) funded a
multiyear project related to sediment transport conditions along the Sagavanirktok River. The
general objectives of these projects include determining ice elevations, identifying possible water
sources, establishing surface hydro-meteorological conditions prior to breakup, measuring
hydro-sedimentological conditions during breakup and summer, and reviewing historical
imagery of the aufeis extent. In the present report, we focus on new data and analyze it in the
context of previous data.
We calculated and compared ice thickness near Franklin Bluffs for 2015, 2016, and 2017, and
found that, in general, ice thickness during both 2015 and 2016 was greater than in 2017 across
most of the study area. Results from a stable isotope analysis indicate that winter overflow,
which forms the aufeis in the river area near Franklin Bluffs, has similar isotopic characteristics
to water flowing from mountain springs.
End-of-winter snow surveys (in 2016/2017) within the watershed indicate that the average snow
water equivalent was similar to what we observed in winter 2015/2016. Air temperatures in May
2017 were low on the Alaska North Slope, which caused a long and gradual breakup, with peak
flows occurring in early June, compared with mid-May in both 2015 and 2016. Maximum
discharge measured at the East Bank station, near Franklin Bluffs was 750 m3/s (26,485 ft3/s) on
May 30, 2017, while the maximum measured flow was 1560 m3/s (55,090 ft3/s) at the same
station on May 20, 2015. Available cumulative rainfall data indicate that 2016 was wetter than
2017.
ii
In September 2015, seven dry and wet pits were dug near the hydro-sedimentological monitoring
stations along the Sagavanirktok River study reach. The average grain-size of the sediment of
exposed gravel bars at sites located upstream of the Ivishak-Sagavanirktok confluence show
relatively constant values. Grain size becomes finer downstream of the confluence.
We conducted monthly topo-bathymetric surveys during the summer months of 2016 and 2017
in each pit. Sediment deposition and erosion was observed in each of the pits. Calculated
sedimentation volumes in each pit show the influence of the Ivishak River in the bed sedimenttransport
capacity of the Sagavanirktok River. In addition, comparison between dry and wet pit
sedimentation volumes in some of the stations proves the complexity of a braided river, which is
characterized by frequent channel shifting
A two-dimensional hydraulic model is being implemented for a material site. The model will be
used to estimate the required sediment refill time based on different river conditions.ABSTRACT ..................................................................................................................................... i
LIST OF FIGURES ......................................................................................................................... i
LIST OF TABLES ....................................................................................................................... xiv
ACKNOWLEDGMENTS AND DISCLAIMER ........................................................................ xvi
CONVERSION FACTORS, UNITS, WATER QUALITY UNITS, VERTICAL AND
HORIZONTAL DATUM, ABBREVIATIONS, AND SYMBOLS .......................................... xvii
ABBREVIATIONS, ACRONYMS, AND SYMBOLS .............................................................. xix
1 INTRODUCTION ................................................................................................................... 1
2 STUDY AREA ........................................................................................................................ 2
2.1 Sagavanirktok River near MP318 Site 066 (DSS4) ......................................................... 7
2.2 Sagavanirktok River at Happy Valley Site 005 (DSS3) .................................................. 7
2.3 Sagavanirktok River below the Confluence with the Ivishak River (DSS2) ................... 9
2.4 Sagavanirktok River near MP405 Site 042 (DSS1) ....................................................... 10
3 METHODOLOGY AND EQUIPMENT .............................................................................. 13
3.1 Pits .................................................................................................................................. 13
3.1.1 Excavation............................................................................................................... 13
3.1.2 Surveying ................................................................................................................ 14
3.2 Surface Meteorology ...................................................................................................... 15
3.3 Aufeis Extent .................................................................................................................. 17
3.3.1 Field Methods ......................................................................................................... 18
3.3.2 Imagery ................................................................................................................... 18
3.4 Water Level Measurements ............................................................................................ 19
3.5 Runoff............................................................................................................................. 20
3.6 Suspended Sediment ...................................................................................................... 21
3.7 Turbidity ......................................................................................................................... 22
3.8 Stable Isotopes................................................................................................................ 22
4 RESULTS .............................................................................................................................. 23
4.1 Meteorology ................................................................................................................... 23
4.1.1 Air Temperature ...................................................................................................... 23
4.1.2 Precipitation ............................................................................................................ 31
4.1.2.1 Cold Season Precipitation ................................................................................ 31
4.1.2.2 Warm Season Precipitation ............................................................................. 36
4.1.3 Wind Speed and Direction ...................................................................................... 39
iv
4.2 Aufeis Extent .................................................................................................................. 40
4.2.1 Historical Aufeis at Franklin Bluffs ........................................................................ 41
4.2.2 Delineating Ice Surface Elevation with GPS and Aerial Imagery .......................... 45
4.3 Surface Water Hydrology ............................................................................................... 52
4.3.1 Sagavanirktok River at MP318 (DSS4) .................................................................. 58
4.3.2 Sagavanirktok River at Happy Valley (DSS3) ....................................................... 61
4.3.3 Sagavanirktok River near MP347 (ASS1) .............................................................. 65
4.3.4 Sagavanirktok River below the Ivishak River (DSS2) ........................................... 66
4.3.5 Sagavanirktok River at East Bank (DSS5) near Franklin Bluffs ............................ 70
4.3.6 Sagavanirktok River at MP405 (DSS1) West Channel .......................................... 78
4.3.7 Additional Field Observations ................................................................................ 82
4.3.8 Preliminary Rating Curves and Estimated Discharge ............................................. 85
4.4 Stable Isotopes................................................................................................................ 86
4.5 Sediment Grain Size Distribution .................................................................................. 90
4.5.1 Streambed Sediment Grain Size Distribution ......................................................... 90
4.5.2 Suspended Sediment Grain Size Distribution ......................................................... 94
4.6 Suspended Sediment Concentration ............................................................................... 95
4.6.1 Sagavanirktok River near MP318 (DSS4) .............................................................. 95
4.6.2 Sagavanirktok River at Happy Valley (DSS3) ..................................................... 100
4.6.3 Sagavanirktok River below the Ivishak River (DSS2) ......................................... 105
4.6.4 Sagavanirktok River near MP405 (DSS1) ............................................................ 111
4.6.5 Discussion ............................................................................................................. 114
4.7 Turbidity ....................................................................................................................... 116
4.7.1 Sagavanirktok River near MP318 (DSS4) ............................................................ 116
4.7.2 Sagavanirktok River at Happy Valley (DSS3) ..................................................... 119
4.7.3 Sagavanirktok River below the Ivishak (DSS2) ................................................... 124
4.7.4 Sagavanirktok River near MP405 (DSS1) ............................................................ 126
4.7.5 Discussion ............................................................................................................. 130
4.8 Analysis of Pits............................................................................................................. 130
4.8.1 Photographs of Pits ............................................................................................... 130
4.8.2 GIS Analysis of Pit Bathymetry ........................................................................... 141
4.8.3 Pit Sedimentation .................................................................................................. 142
4.8.4 Erosion Surveys .................................................................................................... 149
4.8.5 Patterns of Sediment Transport Along the River .................................................. 156
v
4.9 Hydraulic Modeling ..................................................................................................... 158
4.9.1 Model Development .............................................................................................. 160
4.9.2 Results of Simulation ............................................................................................ 165
5 CONCLUSIONS ................................................................................................................. 171
6 REFERENCES .................................................................................................................... 174
7 APPENDICES ..................................................................................................................... 18
The Dirichlet-to-Robin Transform
A simple transformation converts a solution of a partial differential
equation with a Dirichlet boundary condition to a function satisfying a Robin
(generalized Neumann) condition. In the simplest cases this observation enables
the exact construction of the Green functions for the wave, heat, and
Schrodinger problems with a Robin boundary condition. The resulting physical
picture is that the field can exchange energy with the boundary, and a delayed
reflection from the boundary results. In more general situations the method
allows at least approximate and local construction of the appropriate reflected
solutions, and hence a "classical path" analysis of the Green functions and the
associated spectral information. By this method we solve the wave equation on
an interval with one Robin and one Dirichlet endpoint, and thence derive
several variants of a Gutzwiller-type expansion for the density of eigenvalues.
The variants are consistent except for an interesting subtlety of
distributional convergence that affects only the neighborhood of zero in the
frequency variable.Comment: 31 pages, 5 figures; RevTe
From Linear Optical Quantum Computing to Heisenberg-Limited Interferometry
The working principles of linear optical quantum computing are based on
photodetection, namely, projective measurements. The use of photodetection can
provide efficient nonlinear interactions between photons at the single-photon
level, which is technically problematic otherwise. We report an application of
such a technique to prepare quantum correlations as an important resource for
Heisenberg-limited optical interferometry, where the sensitivity of phase
measurements can be improved beyond the usual shot-noise limit. Furthermore,
using such nonlinearities, optical quantum nondemolition measurements can now
be carried out at the single-photon level.Comment: 10 pages, 5 figures; Submitted to a Special Issue of J. Opt. B on
"Fluctuations and Noise in Photonics and Quantum Optics" (Herman Haus
Memorial Issue); v2: minor change
Positioning and clock synchronization through entanglement
A method is proposed to employ entangled and squeezed light for determining
the position of a party and for synchronizing distant clocks. An accuracy gain
over analogous protocols that employ classical resources is demonstrated and a
quantum-cryptographic positioning application is given, which allows only
trusted parties to learn the position of whatever must be localized. The
presence of a lossy channel and imperfect photodetection is considered. The
advantages in using partially entangled states is discussed.Comment: Revised version. 9 pages, 6 figure
Entanglement and visibility at the output of a Mach-Zehnder interferometer
We study the entanglement between the two beams exiting a Mach-Zehnder
interferometer fed by a couple of squeezed-coherent states with arbitrary
squeezing parameter. The quantum correlations at the output are function of the
internal phase-shift of the interferometer, with the output state ranging from
a totally disentangled state to a state whose degree of entanglement is an
increasing function of the input squeezing parameter. A couple of squeezed
vacuum at the input leads to maximum entangled state at the output. The fringes
visibilities resulting from measuring the coincidence counting rate or the
squared difference photocurrent are evaluated and compared each other.
Homodyne-like detection turns out to be preferable in almost all situations,
with the exception of the very low signals regime.Comment: 6 figs, accepted for publication on PRA, see also
http://enterprise.pv.infn.it/~pari
Quantum noise in the position measurement of a cavity mirror undergoing Brownian motion
We perform a quantum theoretical calculation of the noise power spectrum for
a phase measurement of the light output from a coherently driven optical cavity
with a freely moving rear mirror. We examine how the noise resulting from the
quantum back action appears among the various contributions from other noise
sources. We do not assume an ideal (homodyne) phase measurement, but rather
consider phase modulation detection, which we show has a different shot noise
level. We also take into account the effects of thermal damping of the mirror,
losses within the cavity, and classical laser noise. We relate our theoretical
results to experimental parameters, so as to make direct comparisons with
current experiments simple. We also show that in this situation, the standard
Brownian motion master equation is inadequate for describing the thermal
damping of the mirror, as it produces a spurious term in the steady-state phase
fluctuation spectrum. The corrected Brownian motion master equation [L. Diosi,
Europhys. Lett. {\bf 22}, 1 (1993)] rectifies this inadequacy.Comment: 12 pages revtex, 2 figure
The hybrid spectral problem and Robin boundary conditions
The hybrid spectral problem where the field satisfies Dirichlet conditions
(D) on part of the boundary of the relevant domain and Neumann (N) on the
remainder is discussed in simple terms. A conjecture for the C_1 coefficient is
presented and the conformal determinant on a 2-disc, where the D and N regions
are semi-circles, is derived. Comments on higher coefficients are made.
A hemisphere hybrid problem is introduced that involves Robin boundary
conditions and leads to logarithmic terms in the heat--kernel expansion which
are evaluated explicitly.Comment: 24 pages. Typos and a few factors corrected. Minor comments added.
Substantial Robin additions. Substantial revisio
Generation of squeezed states of light with a fiber-optic ring interferometer
Forward nondegenerate four-wave mixing in an optical-fiber ring resonator is proposed as a method to generate squeezed states of light. The nonlinear interactions are analyzed both with a self-consistent propagation-equation technique and with Fokker-Planck equations in the Glauber-Sudarshan P representation. Excellent squeezing is predicted at modest input power levels, with perfect quantum-noise squeezing at the critical points for optical bistability. A method to suppress the stimulated Brillouin effect is proposed and demonstrated experimentally, and the effects of forward spontaneous guided acoustic wave Brillouin scattering inside the resonator are analyzed. Methods are suggested for minimizing this noise under conditions where squeezing can be detected. Experimental apparatus and procedures are outlined for verifying the predictions of our theory and demonstrating squeezing of classical and quantum noise
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