583 research outputs found
A sub-regional management framework for South Pacific longline fisheries
The principal objective of this study was to determine if additional net benefits can be derived from the sub-regional longline fishery by the introduction of a new management agreement that would centre on the provision of licensing arrangements that would allow access by eligible
longline vessels to multiple Exclusive Economic Zones, i.e. Multi-zone Access. [90pp.
Time-in-area represents foraging activity in a wide-ranging pelagic forager
Successful Marine Spatial Planning depends upon the identification of areas with high importance for particular species, ecosystems or processes. For seabirds, advancements in biologging devices have enabled us to identify these areas through the detailed study of at-sea behaviour. However, in many cases, only positional data are available and the presence of local biological productivity and hence seabird foraging behaviour is inferred from these data alone, under the untested assumption that foraging activity is more likely to occur in areas where seabirds spend more time. We fitted GPS devices and accelerometers to northern gannets Morus bassanus and categorised the behaviour of individuals outside the breeding colony as plunge diving, surface foraging, floating and flying. We then used the locations of foraging events to test the efficiency of 2 approaches: time-in-area and kernel density (KD) analyses, which are widely employed to detect highly-used areas and interpret foraging behaviour from positional data. For KD analyses, the smoothing parameter (h) was calculated using the ad hoc method (KDad hoc), and KDh=9.1, where h = 9.1 km, to designate core foraging areas from location data. A high proportion of foraging events occurred in core foraging areas designated using KDad hoc, KDh=9.1, and time-in-area. Our findings demonstrate that foraging activity occurs in areas where seabirds spend more time, and that both KD analysis and the time-in-area approach are equally efficient methods for this type of analysis. However, the time-in-area approach is advantageous in its simplicity, and in its ability to provide the shapes commonly used in planning. Therefore, the time-in-area approach can be used as a simple way of using seabirds to identify ecologically important locations from both tracking and survey data
ํ๊ตญ์ธ์ ํต์ผ๋ฐฉ์์ ๋ํ ์จ๊ฒจ์ง ์ ํธ: ์ ํํ ์ปจ์กฐ์ธํธ ๋ถ์(Choice-based Conjoint Analysis) ๊ฒฐ๊ณผ๋ฅผ ์ค์ฌ์ผ๋ก
๋ณธ๊ณ ๋ ํต์ผ์์ ์ฐ๊ตฌ์์ ๊ทธ๋์ ํ์ฉ๋์ง์์๋ ์ปจ์กฐ์ธํธ ๋ถ์(conjoint analysis)์ํตํด ํ๊ตญ ๊ตญ๋ฏผ์ ํต์ผ๋ฐฉ์์ ๋ ์ธ๋ถ์ ์ด๊ณ ์ ๋ฐํ๊ฒ ์ธก์ ํ๋ ๋ฐ ๋ชฉ์ ์ ๋๋ค. ํต์ผ์์์ ์ธก์ ํ๋ ๊ธฐ์กด ์ฐ๊ตฌ ๋ฐฉ๋ฒ๋ก ์ ์ง์ ๋จ๋ตํ๋คํญ ์ ํ์ ๋ฌธํญ์ผ๋ก ํต์ผ์ ํ์์ฑ, ์๊ธฐ, ํต์ผ๊ด, ํต์ผํ๋ฐ๋์ ์ ์น์ฒด์ ๋ฑ ์ต์ข
์ฒด์ ์ ๊ดํ ์ง๋ฌธ์ผ๋ก ์ธก์ ํด์๋ค. ๊ทธ๋ฐ๋ฐ ๊ฐ ๋ณ์ ๋ด ์ ํ์ง์ ๋ํ ์ ํธ ํน์ ๋น์ ํธ์ ๊ฐ๋๋ฅผ ์ธก์ ํ ์ ์์๊ธฐ์ ์ด๋ ์กฐ๊ฑด์ด ๋ ์ค์ํ๊ฒ ์ฌ๊ฒจ์ง๋์ง ์ ์ ์์๋ค. ๋ฐ๋ผ์ ๊ธฐ์กด ์กฐ์ฌ ๊ฒฐ๊ณผ๋ฅผ ํ์ฉํ ๋ณตํฉ์ ์ ์ฑ
์ค๊ณ๋ ํ๊ณ๊ฐ์กด์ฌํ๋ค. ๋ณธ ์ฐ๊ตฌ๋ ์ปจ์กฐ์ธํธ ๋ถ์์ด๋ผ๋ ์คํ์ ์กฐ์ฌ์ค๊ณ๋ฅผ ํ์ฉํ์ฌ ํต์ผ ํ์ ์ ์น์ฒด์ , ๋ถํ ์ง๋๋ถ ์ ๋ฆฌ, ๋
ธ๋๋น ๋น์ ์ ๋ฆฌ, ๋จํ๊ธฐ์
์ ๋ถํ ๊ฒฝ์ ์ฐธ์ฌ, ๋ถํ ์ง์ญ ๊ตฐ๋ ์ฃผ๋๋ฌธ์ ๋ฑ ์ฌ๋ฌ ์ฐจ์์ ์์ฑ์์ค์ผ๋ก ์ค๋ฌธ์ง๋ฅผ๊ตฌ์ฑํ์ฌ ์ค์ ์ ํธ๋๋ฅผ ๋์ถํ๊ณ ์ ํ๋ค. ์ฐ๊ตฌ ๊ฒฐ๊ณผ๋ ์ฐํฉ์ ๋ณด๋ค ๋จ์ผ๋ฏผ์ฃผ ์ ๋ถ์ ๋ํ์ ํธ, ๋
ธ๋๋น ๋น์์ ๋ํ ๋ฏผ๊ฐํ ์ง์์ ๋ฐฐ์ ์ ์ง๋๋ถ์ ๊ธฐ์ ๋ฑ ์ฌ๋ฌ ์ฐจ์์์ ๊ฐํ ์ ํธ๊ฐ ๋ํ๋ฌ๋ค. ๋ณธ ์ฐ๊ตฌ๋ ํ๊ตญ ๊ตญ๋ฏผ์ ํต์ผ๋ฐฉ์์ ๋ํ ๊ตฌ์ฒด์ ์ธ ์ ํธ๋ฅผ ๋ณด์ฌ์ค์ผ๋ก์จ, ํต์ผ์ด ๊ฐ์์ค๋ฝ๊ฒ ์ด๋ฃจ์ด์ง ๊ฒฝ์ฐ, ํต์ผ์ ๋ํ ์ ์ฑ
์ค๊ณ๋ฅผ ์ํ ์ ์ตํ ์๋ฃ๋ฅผ ์ ๊ณตํ ๊ฒ์ผ๋ก ๊ธฐ๋๋๋ค.Asian Studie
Self-Organized Criticality in Compact Plasmas
Compact plasmas, that exist near black-hole candidates and in gamma ray burst
sources, commonly exhibit self-organized non-linear behavior. A model that
simulates the non-linear behavior of compact radiative plasmas is constructed
directly from the observed luminosity and variability. The simulation shows
that such plasmas self organize, and that the degree of non-linearity as well
as the slope of the power density spectrum increase with compactness. The
simulation is based on a cellular automaton table that includes the properties
of the hot (relativistic) plasmas, and the magnitude of the energy
perturbations. The plasmas cool or heat up, depending on whether they release
more or less than the energy of a single perturbation. The energy release
depends on the plasmas densities and temperatures, and the perturbations
energy. Strong perturbations may cool the previously heated plasma through
shocks and/or pair creation.
New observations of some active galactic nuclei and gamma ray bursters are
consistent with the simulationComment: 9 pages, 5 figures, AASTeX, Submitted to ApJ
Ferromagnetic transition in a double-exchange system
We study ferromagnetic transition in three-dimensional double-exchange model.
The influence of strong spin fluctuations on conduction electrons is described
in coherent potential approximation. In the framework of thermodynamic approach
we construct for the system "electrons (in a disordered spin configuration) +
spins" the Landau functional, from the analysis of which critical temperature
of ferromagnetic transition is calculated.Comment: 4 pages, 1 eps figure, LaTeX2e, RevTeX. References added, text
change
Parity Violation in Proton-Proton Scattering
Measurements of parity-violating longitudinal analyzing powers (normalized
asymmetries) in polarized proton-proton scattering provide a unique window on
the interplay between the weak and strong interactions between and within
hadrons. Several new proton-proton parity violation experiments are presently
either being performed or are being prepared for execution in the near future:
at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at
230 MeV and near 1.3 GeV. These experiments are intended to provide stringent
constraints on the set of six effective weak meson-nucleon coupling constants,
which characterize the weak interaction between hadrons in the energy domain
where meson exchange models provide an appropriate description. The 221 MeV is
unique in that it selects a single transition amplitude (3P2-1D2) and
consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The
TRIUMF 221 MeV proton-proton parity violation experiment is described in some
detail. A preliminary result for the longitudinal analyzing power is Az = (1.1
+/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are
commented on. The anomaly at 6 GeV/c requires that a new multi-GeV
proton-proton parity violation experiment be performed.Comment: 13 Pages LaTeX, 5 PostScript figures, uses espcrc1.sty. Invited talk
at QULEN97, International Conference on Quark Lepton Nuclear Physics --
Nonperturbative QCD Hadron Physics & Electroweak Nuclear Processes --, Osaka,
Japan May 20--23, 199
A Multiwavelength Photometric Census of AGN and Star Formation Activity in the Brightest Cluster Galaxies of X-ray Selected Clusters
Despite their reputation as being โred and deadโ, the unique environment inhabited by brightest cluster galaxies (BCGs) can often lead to a self-regulated feedback cycle between radiatively cooling intracluster gas and star formation and active galactic nucleus (AGN) activity in the BCG. However the prevalence of โactiveโ BCGs, and details of the feedback involved, are still uncertain. We have performed an optical, UV and mid-IR photometric analysis of the BCGs in 981 clusters at 0.03 < z < 0.5, selected from the ROSAT All Sky Survey. Using Pan-STARRS PS1 3ฯ, GALEX and WISE survey data we look for BCGs with photometric colours which deviate from that of the bulk population of passive BCGs โ indicative of AGN and/or star formation activity within the BCG. We find that whilst the majority of BCGs are consistent with being passive, at least 14โperโcent of our BCGs show a significant colour offset from passivity in at least one colour index. And, where available, supplementary spectroscopy reveals the majority of these particular BCGs show strong optical emission lines. On comparing BCG โactivityโ with the X-ray luminosity of the host cluster, we find that BCGs showing a colour offset are preferentially found in the more X-ray luminous clusters, indicative of the connection between BCG โactivityโ and the intracluster medium
Electroproduction of the d* dibaryon
The unpolarized cross section for the electroproduction of the isoscalar
di-delta dibaryon is calculated for deuteron target using a
simple picture of elastic electron-baryon scattering from the and the components of the deuteron. The calculated
differential cross section at the electron lab energy of 1 GeV has the value of
about 0.24 (0.05) nb/sr at the lab angle of 10 (30) for the
Bonn B potential when the dibaryon mass is taken to be 2.1 GeV. The cross
section decreases rapidly with increasing dibaryon mass. A large calculated
width of 40 MeV for combined with a small
experimental upper bound of 0.08 MeV for the decay width appears to have
excluded any low-mass model containing a significant admixture of the
configuration.Comment: 11 journal-style pages, 8 figure
A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment
TRIUMF experiment E497 is a study of parity violation in pp scattering at an
energy where the leading term in the analyzing power is expected to vanish,
thus measuring a unique combination of weak-interaction flavour conserving
terms. It is desired to reach a level of sensitivity of 2x10^-8 in both
statistical and systematic errors. The leading systematic errors depend on
transverse polarization components and, at least, the first moment of
transverse polarization. A novel polarimeter that measures profiles of both
transverse components of polarization as a function of position is described.Comment: 19 pages LaTeX, 10 PostScript figures. To appear in Nuclear
Instruments and Methods in Physics Research, Section
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