12,142 research outputs found
Home Ranges and Movements of Adult Deer on Fort Chaffee, Arkansas
We radio-tracked 27 white-tailed deer (Odocoileus virginianus) weekly for one year on Fort Chaffee, Arkansas, to investigate their seasonal home ranges and movements between hunted areas and refuges on this military base. This work resulted in2,123 separate radiolocations, of which 85% (1,799) were suitable for use in home range analyses. We used the McPAAL computer package to estimate home range using the Harmonic Mean and minimum convex polygon (MCP) methods. Harmonic mean estimates were based on 95% contour lines. Home range size differed between the sexes and methods. Male home ranges were larger than those of females (t= 3.32, P\u3c0.01; harmonic mean) (t=2.07, P\u3c0.05; MCP). Average home range sizes for males and females based on the harmonic mean method were estimated to be 483 ha and 181 ha, respectively, whereas home range estimates for males and females using the MCP method were 636 ha and 289 ha, respectively. The average home range size for all deer was 259 ha (harmonic mean) and 379 ha (MCP). We found no evidence that females restricted their home ranges during the fawning period. However, females\u27 home ranges expanded during the breeding season, perhaps to find mates. Few deer moved to refuge areas that were off-limits to hunters during the hunting season
Mortality of Adult White-Tailed Deer on Fort Chaffee, Arkansas
We conducted a telemetry study on Fort Chaffee, Arkansas, to estimate the extent, timing, and causes of mortality among resident adult white-tailed deer {Odocoileus virginianus). Twenty-seven deer were captured, radio-collared and monitored for 1 yr to assess seasonal mortality. Annual mortality rates differed considerably between sexes, with males exhibiting a much higher rate (86.1%) than females (5.3%). The primary causes of death among males were poaching, predation by coyotes, and legal harvest. Legal harvest by a gun-hunter accounted for the only female mortality. No mortalities were attributed to military exercises, which occurred frequently on the study area. Our results suggest that the male segment of the population would benefit from increased enforcement efforts to reduce illegal harvests and that continued liberal harvest of the female segment is advisable to maintain a balanced population sex ratio
Running coupling and mass anomalous dimension of SU(3) gauge theory with two flavors of symmetric-representation fermions
We have measured the running coupling constant of SU(3) gauge theory coupled
to Nf=2 flavors of symmetric representation fermions, using the Schrodinger
functional scheme. Our lattice action is defined with hypercubic smeared links
which, along with the larger lattice sizes, bring us closer to the continuum
limit than in our previous study. We observe that the coupling runs more slowly
than predicted by asymptotic freedom, but we are unable to observe fixed point
behavior before encountering a first order transition to a strong coupling
phase. This indicates that the infrared fixed point found with the thin-link
action is a lattice artifact. The slow running of the gauge coupling permits an
accurate determination of the mass anomalous dimension for this theory, which
we observe to be small, gamma_m < 0.6, over the range of couplings we can
reach. We also study the bulk and finite-temperature phase transitions in the
strong coupling region.Comment: 17 pages, 16 figures. Substantial modifications to explain why the
fat-link result for the beta function supersedes our thin-link result; also
updated the phase diagram to reflect additional numerical work. Added
references. Final versio
Importance of Tests for the Complete Lorentz Structure of the t --> W+ b vertex at Hadron Colliders
The most general Lorentz-invariant decay-density-matrix for , or for , is expressed in terms
of eight helicity parameters. The parameters are physically defined in terms of
partial-width-intensities for polarized-final-states in decay.
The parameters are the partial width, the quark's chirality parameter
, the polarimetry parameter , a "pre-SSB" test parameter
, and four - interference parameters , ,
, which test for violation. They can be
used to test for non-CKM-type CP violation, anomalous 's, top
weak magnetism, weak electricity, and second-class currents. By stage-two
spin-correlation techniques, percent level statistical uncertainites are
typical for measurements at the Tevatron, and several mill level uncertainites
are typical at the LHC.Comment: Minor clarifications. Expression for r_{+-} corrected. 19 pages LaTex
+ Tables + 1 Figur
Analyzing and improving throughput of Automated Storage and Retrieval Systems in personal computer manufacturing
Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2005.Includes bibliographical references (leaf 85).The content of this thesis draws heavily on work completed during a 6.5 month MIT Leaders for Manufacturing (LFM) internship at Dell Corporation's personal computer manufacturing facility in Lebanon, Tennessee (EG1) from June 2004 to December 2004. This work relates primarily to efforts to analyze and improve the throughput of the Automated Storage and Retrieval System (ASRS) in that factory. Wherever possible, the thesis abstracts from the EG1 factory case study to provide lessons for improving the throughput of ASRSs and accumulative manufacturing systems in general. In addition to this core of the thesis, specific implementation challenges encountered during the EG 1 case study are addressed. Finally, general cultural observations about Dell's manufacturing environment are discussed. The author believes the two most unique aspects of this work are the Crane Frontier framework developed for analyzing ASRS throughput (Section 2.6) and the range and taxonomy of ASRS throughput improvement solutions (Chapter 3).by G. Thomas Heaps-Nelson.S.M.M.B.A
Rigid Chiral Membranes
Statistical ensembles of flexible two-dimensional fluid membranes arise
naturally in the description of many physical systems. Typically one encounters
such systems in a regime of low tension but high stiffness against bending,
which is just the opposite of the regime described by the Polyakov string. We
study a class of couplings between membrane shape and in-plane order which
break 3-space parity invariance. Remarkably there is only {\it one} such
allowed coupling (up to boundary terms); this term will be present for any
lipid bilayer composed of tilted chiral molecules. We calculate the
renormalization-group behavior of this relevant coupling in a simplified model
and show how thermal fluctuations effectively reduce it in the infrared.Comment: 11 pages, UPR-518T (This replaced version has fonts not used
removed.
The Minimal Moose for a Little Higgs
Recently a new class of theories of electroweak symmetry breaking have been
constructed. These models, based on deconstruction and the physics of theory
space, provide the first alternative to weak-scale supersymmetry with naturally
light Higgs fields and perturbative new physics at the TeV scale. The Higgs is
light because it is a pseudo-Goldstone boson, and the quadratically divergent
contributions to the Higgs mass are cancelled by new TeV scale ``partners'' of
the {\em same} statistics. In this paper we present the minimal theory space
model of electroweak symmetry breaking, with two sites and four link fields,
and the minimal set of fermions. There are very few parameters and degrees of
freedom beyond the Standard Model. Below a TeV, we have the Standard Model with
two light Higgs doublets, and an additional complex scalar weak triplet and
singlet. At the TeV scale, the new particles that cancel the 1-loop quadratic
divergences in the Higgs mass are revealed. The entire Higgs potential needed
for electroweak symmetry breaking--the quartic couplings as well as the
familiar negative mass squared--can be generated by the top Yukawa coupling,
providing a novel link between the physics of flavor and electroweak symmetry
breaking.Comment: 15 pages. References added. Included clarifying comments on the
origin of quartic couplings, and on power-counting. More elegant model for
generating Higgs potential from top Yukawa coupling presente
Steric repulsion and van der Waals attraction between flux lines in disordered high Tc superconductors
We show that in anisotropic or layered superconductors impurities induce a
van der Waals attraction between flux lines. This attraction together with the
disorder induced repulsion may change the low B - low T phase diagram
significantly from that of the pure thermal case considered recently by Blatter
and Geshkenbein [Phys. Rev. Lett. 77, 4958 (1996)].Comment: Latex, 4 pages, 1 figure (Phys. Rev. Lett. 79, 139 (1997)
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