583 research outputs found

    A sub-regional management framework for South Pacific longline fisheries

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    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

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    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

    ํ•œ๊ตญ์ธ์˜ ํ†ต์ผ๋ฐฉ์‹์— ๋Œ€ํ•œ ์ˆจ๊ฒจ์ง„ ์„ ํ˜ธ: ์„ ํƒํ˜• ์ปจ์กฐ์ธํŠธ ๋ถ„์„(Choice-based Conjoint Analysis) ๊ฒฐ๊ณผ๋ฅผ ์ค‘์‹ฌ์œผ๋กœ

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    ๋ณธ๊ณ ๋Š” ํ†ต์ผ์˜์‹ ์—ฐ๊ตฌ์—์„œ ๊ทธ๋™์•ˆ ํ™œ์šฉ๋˜์ง€์•Š์•˜๋˜ ์ปจ์กฐ์ธํŠธ ๋ถ„์„(conjoint analysis)์„ํ†ตํ•ด ํ•œ๊ตญ ๊ตญ๋ฏผ์˜ ํ†ต์ผ๋ฐฉ์‹์„ ๋” ์„ธ๋ถ€์ ์ด๊ณ ์ •๋ฐ€ํ•˜๊ฒŒ ์ธก์ •ํ•˜๋Š” ๋ฐ ๋ชฉ์ ์„ ๋‘”๋‹ค. ํ†ต์ผ์˜์‹์„ ์ธก์ •ํ•˜๋Š” ๊ธฐ์กด ์—ฐ๊ตฌ ๋ฐฉ๋ฒ•๋ก ์€ ์ง์ ‘ ๋‹จ๋‹ตํ˜•๋‹คํ•ญ ์„ ํƒ์‹ ๋ฌธํ•ญ์œผ๋กœ ํ†ต์ผ์˜ ํ•„์š”์„ฑ, ์‹œ๊ธฐ, ํ†ต์ผ๊ด€, ํ†ต์ผํ•œ๋ฐ˜๋„์˜ ์ •์น˜์ฒด์ œ ๋“ฑ ์ตœ์ข… ์ฒด์ œ์— ๊ด€ํ•œ ์งˆ๋ฌธ์œผ๋กœ ์ธก์ •ํ•ด์™”๋‹ค. ๊ทธ๋Ÿฐ๋ฐ ๊ฐ ๋ณ€์ˆ˜ ๋‚ด ์„ ํƒ์ง€์— ๋Œ€ํ•œ ์„ ํ˜ธ ํ˜น์€ ๋น„์„ ํ˜ธ์˜ ๊ฐ•๋„๋ฅผ ์ธก์ •ํ•  ์ˆ˜ ์—†์—ˆ๊ธฐ์— ์–ด๋Š ์กฐ๊ฑด์ด ๋” ์ค‘์š”ํ•˜๊ฒŒ ์—ฌ๊ฒจ์ง€๋Š”์ง€ ์•Œ ์ˆ˜ ์—†์—ˆ๋‹ค. ๋”ฐ๋ผ์„œ ๊ธฐ์กด ์กฐ์‚ฌ ๊ฒฐ๊ณผ๋ฅผ ํ™œ์šฉํ•œ ๋ณตํ•ฉ์  ์ •์ฑ… ์„ค๊ณ„๋Š” ํ•œ๊ณ„๊ฐ€์กด์žฌํ•œ๋‹ค. ๋ณธ ์—ฐ๊ตฌ๋Š” ์ปจ์กฐ์ธํŠธ ๋ถ„์„์ด๋ผ๋Š” ์‹คํ—˜์  ์กฐ์‚ฌ์„ค๊ณ„๋ฅผ ํ™œ์šฉํ•˜์—ฌ ํ†ต์ผ ํ›„์˜ ์ •์น˜์ฒด์ œ, ๋ถํ•œ ์ง€๋„๋ถ€ ์ •๋ฆฌ, ๋…ธ๋™๋‹น ๋‹น์› ์ •๋ฆฌ, ๋‚จํ•œ๊ธฐ์—…์˜ ๋ถํ•œ ๊ฒฝ์ œ์ฐธ์—ฌ, ๋ถํ•œ ์ง€์—ญ ๊ตฐ๋Œ€ ์ฃผ๋‘”๋ฌธ์ œ ๋“ฑ ์—ฌ๋Ÿฌ ์ฐจ์›์˜ ์†์„ฑ์ˆ˜์ค€์œผ๋กœ ์„ค๋ฌธ์ง€๋ฅผ๊ตฌ์„ฑํ•˜์—ฌ ์‹ค์ œ ์„ ํ˜ธ๋„๋ฅผ ๋„์ถœํ•˜๊ณ ์ž ํ•œ๋‹ค. ์—ฐ๊ตฌ ๊ฒฐ๊ณผ๋Š” ์—ฐํ•ฉ์ œ๋ณด๋‹ค ๋‹จ์ผ๋ฏผ์ฃผ ์ •๋ถ€์— ๋Œ€ํ•œ์„ ํ˜ธ, ๋…ธ๋™๋‹น ๋‹น์›์— ๋Œ€ํ•œ ๋ฏผ๊ฐํ•œ ์ง์œ„์˜ ๋ฐฐ์ œ์™€ ์ง€๋„๋ถ€์˜ ๊ธฐ์†Œ ๋“ฑ ์—ฌ๋Ÿฌ ์ฐจ์›์—์„œ ๊ฐ•ํ•œ ์„ ํ˜ธ๊ฐ€ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋ณธ ์—ฐ๊ตฌ๋Š” ํ•œ๊ตญ ๊ตญ๋ฏผ์˜ ํ†ต์ผ๋ฐฉ์•ˆ์— ๋Œ€ํ•œ ๊ตฌ์ฒด์ ์ธ ์„ ํ˜ธ๋ฅผ ๋ณด์—ฌ์คŒ์œผ๋กœ์จ, ํ†ต์ผ์ด ๊ฐ‘์ž‘์Šค๋Ÿฝ๊ฒŒ ์ด๋ฃจ์–ด์งˆ ๊ฒฝ์šฐ, ํ†ต์ผ์— ๋Œ€ํ•œ ์ •์ฑ…์„ค๊ณ„๋ฅผ ์œ„ํ•œ ์œ ์ตํ•œ ์ž๋ฃŒ๋ฅผ ์ œ๊ณตํ•  ๊ฒƒ์œผ๋กœ ๊ธฐ๋Œ€๋œ๋‹ค.Asian Studie

    Self-Organized Criticality in Compact Plasmas

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    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

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    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

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    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

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    Despite their reputation as being โ€˜red 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 โ€˜activeโ€™ 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 14โ€‰perโ€‰cent 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 โ€˜activityโ€™ 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 โ€˜activityโ€™ and the intracluster medium

    Electroproduction of the d* dibaryon

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    The unpolarized cross section for the electroproduction of the isoscalar Jฯ€=3+J^\pi = 3^+ di-delta dibaryon dโˆ—d^* is calculated for deuteron target using a simple picture of elastic electron-baryon scattering from the ฮ”ฮ”(7D1)\Delta \Delta (^7D_1) and the NN(3S1)NN (^3S_1) 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 10โˆ˜^\circ (30โˆ˜^\circ) 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 dโˆ—(ฮ”ฮ”7S3)d^*(\Delta\Delta ^7S_3) combined with a small experimental upper bound of 0.08 MeV for the dโˆ—d^* decay width appears to have excluded any low-mass dโˆ—d^* model containing a significant admixture of the ฮ”ฮ”(7S3)\Delta\Delta (^7S_3) configuration.Comment: 11 journal-style pages, 8 figure

    A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

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    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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