Structures for caribou management and their status in the circumpolar north

Large herds of caribou (Rangifer tarandus) in Canada, Alaska, and Russia that winter in northern coniferous forests and summer in tundra of the Arctic have provided a sustainable source of meat and other products for indigenous peoples for thousands of years. Several different administrative structures for management of large caribou herds have emerged throughout the circumpolar North. In Russia under the previous Soviet government, the herd of the Taimyr Region, numbering around 500 000 caribou, was managed under a harvest quota system for both subsistence use by indigenous people and commercial sale of meat and skins. In North America, as indigenous peoples have gained increasing political empowerment, systems for caribou management have been undergoing change. Establishment of the Beverly and Qamanirjuaq Caribou Management Board in Canada, with majority representation from users of the resource, provides a model and a test of the effectiveness of a comanagement system. The Western Arctic Herd in northwestern Alaska, numbering close to 500 000 caribou, has been managed under the traditional American system of game management, with user advisory groups, but with management decisions resting with a statewide Board of Game, whose major representation is from sport-hunting interests. The Porcupine Caribou Herd, which is shared by the United States and Canada, is the focus of an international agreement, in principle designed to assure its continued productivity and well-being. The diversity of systems for caribou management in the circumpolar North provides an opportunity for comparing their effectiveness

Assessing effectiveness of caribou management systems: Alaska's Western Arctic Herd and Canada's Beverly and Qamanirjuaq Herds

Our hope is that this analysis will highlight the best elements of each management system, which collectively will serve as a model to improve the management of large caribou herds in North America

Glycemic response of poultries in different feeding systems

The management of poultry feed is an important welfare promoter and the glycemic index a noninvasive evaluation. The aim was to evaluate the glycemic response of broiler breeders in restricted feeding system, and broilers receiving ad libitum feeding. Two experiments were carried out: I) 39-week-oldbroiler breeders, fed with three sources of fiber, in a completely randomized design in factorial scheme (3 fiber diets x 7 collection periods); and II) broilers, 42 days old, housed in different light systems, in a completely randomized design in factorial design (2 sexes x 2 lighting conditions x 13 collection periods). Blood glucose levels were measured at random collecting one blood drop from foot, with three replicates in each condition and treatment. In broiler breeder different fiber sources had no effect on glycemia, but the period affected circulating glucose levels, presenting a minimum of 184.3 mg dL -1 before feed and, a maximum of 242.5 mg dL -1 four hours after feeding. In broilers, there was a significant effect in glycemia for collection period and for sex, and interaction between lighting conditions and collection period. Further studies are needed to establish reference values to compare blood glucose levels in poultry.41

Measurement of CH2O in low and atmospheric pressure flames by Laser Induced Fluorescence and Cavity RingDown absorption

We have investigated the spatial structure of formaldehyde usinglaser-induced fluorescence (LIF), LIF imaging, and cavity ringdownspectroscopy (CRDS) in two flames. The first is an atmospheric pressureBunsen flame, into which are inserted various metal to simulatedifferent types of heat removal inserts in appliance flames. Here LIFimaging is used. The second is a low pressure flat flame that can bemodeled with a one-dimensional code. All three techniques are used. Theresults in both cases show that CH2O appears prior to CH, inlower pressure regions of the flame

Unitarity and the Bethe-Salpeter Equation

We investigate the relation between different three-dimensional reductions of the Bethe-Salpeter equation and the analytic structure of the resultant amplitudes in the energy plane. This correlation is studied for both the $\phi^2\sigma$ interaction Lagrangian and the $\pi N$ system with $s$-, $u$-, and $t$-channel pole diagrams as driving terms. We observe that the equal-time equation, which includes some of the three-body unitarity cuts, gives the best agreement with the Bethe-Salpeter result. This is followed by other 3-D approximations that have less of the analytic structure.Comment: 17 pages, 8 figures; RevTeX. Version accepted for publication in Phys. Rev.

Columnar defects and vortex fluctuations in layered superconductors

We investigate fluctuations of Josephson-coupled pancake vortices in layered superconductors in the presence of columnar defects. We study the thermodynamics of a single pancake stack pinned by columnar defects and obtain the temperature dependence of localization length, pinning energy and critical current. We study the creep regime and compute the crossover current between line-like creep and pancake-like creep motion. We find that columnar defects effectively increase interlayer Josephson coupling by suppressing thermal fluctuations of pancakes. This leads to an upward shift in the decoupling line most pronounced around the matching field.Comment: 5 pages, REVTeX, no figure

Quantum dots in magnetic fields: thermal response of broken symmetry phases

We investigate the thermal properties of circular semiconductor quantum dots in high magnetic fields using finite temperature Hartree-Fock techniques. We demonstrate that for a given magnetic field strength quantum dots undergo various shape phase transitions as a function of temperature, and we outline possible observable consequences.Comment: In Press, Phys. Rev. B (2001

Relativistic effects and quasipotential equations

We compare the scattering amplitude resulting from the several quasipotential equations for scalar particles. We consider the Blankenbecler-Sugar, Spectator, Thompson, Erkelenz-Holinde and Equal-Time equations, which were solved numerically without decomposition into partial waves. We analyze both negative-energy state components of the propagators and retardation effects. We found that the scattering solutions of the Spectator and the Equal-Time equations are very close to the nonrelativistic solution even at high energies. The overall relativistic effect increases with the energy. The width of the band for the relative uncertainty in the real part of the scattering $T$ matrix, due to different dynamical equations, is largest for backward-scattering angles where it can be as large as 40%.Comment: Accepted for publication in Phys. Rev.

Reduction of myocardial infarction by postischemic administration of the calpain inhibitor A-705253 in comparison to the Na(+)/H(+) exchange inhibitor Cariporide (R) in isolated perfused rabbit hearts

The calpain inhibitor A-705253 and the Na(+)/H(+) exchange inhibitor Cariporide (R) were studied in isolated perfused rabbit hearts subjected to 60 min occlusion of the ramus interventricularis of the left coronary artery (below the origin of the first diagonal branch), followed by 120 min of reperfusion. The inhibitors were added to the perfusion fluid solely or in combination at the beginning of reperfusion. Hemodynamic monitoring and biochemical analysis of perfusion fluid from the coronary outflow were performed. Myocardial infarct size and area at risk (transiently not perfused myocardium) were determined from left ventricular slices after a special staining procedure with Evans blue and 2,3,5-triphenyltetrazolium chloride. The infarcted area (dead myocardium) was 72.7 +/- 4.0% of the area at risk in untreated controls, but was significantly smaller in the presence of the inhibitors. The largest effect was observed with 10(-6) M A-705253, which reduced the infarcted area to 49.2 +/- 4.1% of the area at risk, corresponding to a reduction of 33.6%. Cariporide (R) at 10(-6) M reduced the infarct size to the same extent. The combination of both inhibitors, however, did not further improve cardioprotection. No significant difference was observed between the experimental groups in coronary perfusion, left ventricular pressure, heart rate, or in the release of lactate dehydrogenase and creatine kinase from heart muscle