500 research outputs found
IDENTIFYING INTERACTIONS AMONG SALMON POPULATIONS FROM OBSERVED DYNAMICS
Abstract. A simple direct correlation analysis of individual counts between different populations often fails to characterize the true nature of population interactions; however, the most common data type available for population studies is count data, and one of the most important objectives in population and community ecology is to identify interactions among populations. Here, I examine the dynamics of the spawning abundance of fall-run chinook salmon spawning within the California Central Valley and the Klamath Basin, California, and the Columbia River Basin, Oregon. I analyzed multiple time series from each watershed using a multivariate time-series technique called maximum autocorrelation factor analysis. This technique was used for finding common underlying trends in escapement abundance within each watershed. These trends were further investigated to identify potential resource-mediated interactions among the three groups of salmon. Each group is affected by multiple trends that are likely to be affected by environmental factors. In addition, some of the trends are coherent with each other, and the differences in population dynamics originate from variations in the relative importance of these trends among the three watershed groups
Mark-recapture statistics and demographic analysis
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2002Mark-recapture analysis of populations is becoming an important tool in population biology.
Mark-recapture methods can be used to estimate transition probabilities among life-stages
from capture histories of marked individuals for which stages can be determined at each
sampling occasion. This method is called a multi-stage mark-recapture (MSMR) method.
In this thesis, I describe advances I made in the MSMR method and present analyses that
apply this method to actual data.
The advances I made in the MSMR method are motivated by a need to provide a link
between mark-recapture data and demographic models such as matrix population models
and integrodifference models. I resolve some issues that are commonly encountered during
sampling, such as the fact that the sex or life-stage of some individuals is unknown during
some sampling occasions and that individuals become unobservable during some life-stages.
I introduce a stage-structure that permits simple conversion of estimated transition probabilities
into a matrix population model. I describe an algorithm to simplify programming
for parameter estimation. I also introduce a method to estimate the distribution of dispersal
displacements (a dispersal kernel) from mark-recapture data.
I apply some of the methods described above to data of the North Atlantic right whale
(Eubalaena glacialis) The right whales are considered one of the most endangered mammals.
The current population size is about 300 in the northwestern Atlantic, and the
number is declining. I applied the multi-stage mark-recapture statistics to the 17-year individual
sighting history data. Using the estimated transition probabilities, I constructed
a population projection matrix, which was used for further demographic analyses. I found
that the population was slowly increasing in 1980, but it started to decline slowly around
1992. I show that (1) this change was caused by increased mortality of females that have
just given birth, (2) protecting two females a year from the deaths is enough to prevent the
declining trend, and (3) demographic stochasticity is a more important factor influencing
their long-term viability than environmental stochasticity.The David and Lucile Packard Foundation, the Rinehart Coastal Research Center, and
the Woods Hole Oceanographic Institution Sea Grant Program (NOAA NA86RG0075) supported
this work through grants to Hal Caswell. Graduate Research Fellowship from Woods
Hole Oceanographic Institution also supported the first year of my study
The K1.8BR spectrometer system at J-PARC
A new spectrometer system was designed and constructed at the secondary beam
line K1.8BR in the hadron hall of J-PARC to investigate interactions
and -nuclear bound systems. The spectrometer consists of a high
precision beam line spectrometer, a liquid He/He/D target system, a
Cylindrical Detector System that surrounds the target to detect the decay
particles from the target region, and a neutron time-of-flight counter array
located 15 m downstream from the target position. Details of the design,
construction, and performance of the detector components are described.Comment: 33 pages, 25 figure
The Effects of Disease-Induced Juvenile Mortality on the Transient and Asymptotic Population Dynamics of Chinook Salmon (Oncorhynchus tshawytscha)
The effects of an increased disease mortality rate on the transient and asymptotic dynamics of Chinook salmon (Oncorhynchus tshawytscha) were investigated. Disease-induced mortality of juvenile salmon has become a serious concern in recent years. However, the overall effects of disease mortality on the asymptotic and transient dynamics of adult spawning abundance are still largely unknown. We explored various scenarios with regard to the density-dependent process, the distribution of survivorship over the juvenile phase, the disease mortality rate, and the infusion of stray hatchery fish. Our results suggest that the sensitivity to the disease mortality rate of the equilibrium adult spawning abundance and resilience (asymptotic return rate toward this equilibrium following a small perturbation) varied widely and differently depending on the scenario. The resilience and coefficient of variation of adult spawning abundance following a large perturbation were consistent with each other under the scenarios investigated. We conclude that the increase in disease mortality likely has an effect on fishery yield under a fluctuating environment, not only because the mean equilibrium adult spawning abundance has likely been reduced, but also because the resilience has likely decreased and the variance in adult spawning abundance has likely increased. We also infer the importance of incorporating finer-scale spatiotemporal information into population models and demonstrate a means for doing so within a matrix population modeling framework.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund
High Energy Particle Measurements during Long Discharge in LHD
The spatial resolved energy spectra can be observed during a long discharge of NBI plasma bycontinuously scanning the neutral particle analyzer. In these discharges, the plasmas are initiated by the ECH heating, after that NBI#2 (Co-injection) sustains the plasma during 40-60 seconds. The scanned pitch angle is from 44 degrees to 74 degrees. The injected neutral beam (hydrogen) energy of NBI#2 is only 130 keV because the original ion source polarity is negative. The shape of spectra is almost similar from 44 degrees to 53 degrees. However the spectra from 55 degrees are strongly varied. It reflects the injection pitch angle of the beam according to the simulation (53 degrees ot R* = 3.75 m in simulation). The beam keeps the pitch angle at incidence until the beam energy becomes to the energy, which the pitch angle scattering is occurred by the energy loss due to the electron collision. The low flux region can be observed around 10-15 keV, which is 15 times of the electron temperature. The energy region may be equal to the energy at which the pitch angle scattering is occurred. At the energy, the particle is scattered by the collision with the plasma ions and some of particles may run away from the plasma because they have a possibility to enter the loss cone. According to the simulation, the loss cone can be expected at the 10 keV with the small angular dependence. The depth of the loss cone is deep at the small pitch angle. The hollow in the spectrum may be concluded to be the loss cone as the tendency is almost agreed with the experimental result
A critical analysis of the pneumatology of Thomas Erskine of Linlathen
In performing an analysis of the pneumatology of Thomas Erskine it is first
necessary to look for the presence of a traditional Trinitarian Pneumatology which is
based on the historical findings of the church and which deals with the subject of
hypostasis and the relationships between the Persons within the Godhead. This kind of
pneumatology is found to be lacking in Erskine’s writings. The next step is to proceed to
look for anything that could replace it. Erskine’s concept of the “first bond” of the flesh,
the role of the human conscience, and the place of the living Word are three things that
partially take the place of a formal pneumatology in Erskine’s thinking.
Erskine was very interested in the West Country revival which began in Scotland
in 1829. He visited the area and wrote about his observations and experiences there. This
increased his interest in the actions of the Holy Spirit both in experience and the
scriptures. Even though he later recanted his endorsement of these manifestations in his
own day, he held to his belief that such phenomena should appear in a healthy church
which follows a New Testament pattern.
In this thesis Erskine’s writings are analyzed by scanning all of them into a
computer database and searching for references to the actions of the Holy Spirit. From
this a dynamic pneumatology emerges. A dynamic pneumatology is not concerned with
historic creeds or the relationships within the Godhead, John McIntyre defines a dynamic
pneumatology as one that speaks of what the Holy Spirit does. McIntyre’s taxonomy
sets forth eleven patterns of dynamic pneumatology with many sub-patterns. This
examination of the writings of Erskine reveals a strong dynamic pneumatology which is
both relational and ecclesial
MPP6 stimulates both RRP6 and DIS3 to degrade a specified subset of MTR4-sensitive substrates in the human nucleus
ヒト細胞内でRNA分解時に働く因子の役割を解明 --細胞内におけるRNA分解機構の全容解明に期待--. 京都大学プレスリリース. 2022-08-05.Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome. Using RNA polymerase II-transcribed poly(A)⁺ substrate accumulation as an indicator of a perturbed exosome, we found functional redundancy between RRP6 and MPP6 in the decay of these poly(A)⁺ transcripts. MTR4 binding to the exosome core via MPP6 was essential for MPP6 to exert its redundancy with RRP6. However, at least for the decay of our identified exosome substrates, MTR4 recruitment by MPP6 was not functionally equivalent to recruitment by RRP6. Genome-wide classification of substrates based on their sensitivity to each exosome component revealed that MPP6 deals with a specific range of substrates and highlights the importance of MTR4 for their decay. Considering recent findings of competitive binding to the exosome between auxiliary complexes, our results suggest that the MPP6-incorporated MTR4-exosome complex is one of the multiple alternative complexes rather than the prevailing one
Computation of Temperature Elevation in Rabbit Eye Irradiated By 2.45-Ghz Microwaves With Different Field Configurations
This study calculated the temperature elevation in the rabbit eye caused by 2.45-GHz near-field exposure systems. First, we calculated specific absorption rate distributions in the eye for different antennas and then compared them with those observed in previous studies. Next, we re-examined the temperature elevation in the rabbit eye due to a horizontally-polarized dipole antenna with a C-shaped director, which was used in a previous study. For our computational results, we found that decisive factors of the SAR distribution in the rabbit eye were the polarization of the electromagnetic wave and antenna aperture. Next, we quantified the eye average specific absorption rate as 67 W kg-1 for the dipole antenna with an input power density at the eye surface of 150 mW cm-2, which was specified in the previous work as the minimum cataractogenic power density. The effect of administrating anesthesia on the temperature elevation was 30% or so in the above case. Additionally, the position where maximum temperature in the lens appears is discussed due to different 2.45-GHz microwave systems. That position was found to appear around the posterior of the lens regardless of the exposure condition, which indicates that the original temperature distribution in the eye was the dominant factor.application/pdfjournal articl
Temperature elevation in the eye of anatomically based human head models for plane-wave exposures
This study investigated the temperature elevation in the eye of anatomically based human head models for plane-wave exposures. The finite-difference time-domain method is used for analyzing electromagnetic absorption and temperature elevation. The eyes in the anatomic models have average dimensions and weight. Computational results show that the ratio of maximum temperature in the lens to the eye-average SAR (named 'heating factor for the lens') is almost uniform (0.112?0.147 °C kg W?1) in the frequency region below 3 GHz. Above 3 GHz, this ratio increases gradually with an increase of frequency, which is attributed to the penetration depth of an electromagnetic wave. Particular attention is paid to the difference in the heating factor for the lens between this study and earlier works. Considering causes clarified in this study, compensated heating factors in all these studies are found to be in good agreement.application/pdfjournal articl
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