49,539 research outputs found
Early egg traits in Cancer setosus (Decapoda, Brachyura): effects of temperature and female size
Previous study on Cancer setosus (Molina, 1782) had shown that latitudinal changes in temperature control the number of annual egg masses. This study focused on the effects of pre-oviposition temperature and female size on egg-traits in C. setosus from Northern (Antofagasta 23ÂșS) and Central-Southern (Puerto Montt 41ÂșS) Chile. Blastula eggs produced in nature ranged in dry mass (DM) from 9.1 to 15.1 ”g, in carbon (C) from 4.8 to 8.4 ”g, in nitrogen (N) from 1.0 to 1.6 ”g, in C:N ratio between 4.7 and 5.4, and in volume (V) between 152 and 276 mm3 x 10-4 per female. Blastula eggs from females caught early in the reproductive season in Puerto Montt (09/2006) were significantly higher in DM, C, N, and V than those of females caught two months later (11/2006), reflecting a seasonal increase in water temperature. In Puerto Montt âearlyâ and âlateâ season blastula eggs were about 32% and 20% higher in DM, C, N, and V as eggs from Antofagasta, respectively. Subsequent egg masses produced in captivity in Puerto Montt followed this pattern of smaller eggs with lower DM, C, and N content at higher pre-oviposition temperatures. In Antofagasta no significant difference in DM, C, N and V between eggs produced in nature and subsequent eggs produced in captivity was found and all egg traits were significantly positively affected by maternal size. Reproductive plasticity in C. setosus helps explaining the species wide latitudinal distribution range
VR/Urban: SMSlingshot
In this paper we describe the concept and design objectives of VR/Urban's media intervention tool SMSlingshot, which was presented at the Riga White Night Arts Festival 2009 for the first time
Swinging of red blood cells under shear flow
We reveal that under moderate shear stress (of the order of 0.1 Pa) red blood
cells present an oscillation of their inclination (swinging) superimposed to
the long-observed steady tanktreading (TT) motion. A model based on a fluid
ellipsoid surrounded by a visco-elastic membrane initially unstrained (shape
memory) predicts all observed features of the motion: an increase of both
swinging amplitude and period (1/2 the TT period) upon decreasing the shear
stress, a shear stress-triggered transition towards a narrow shear stress-range
intermittent regime of successive swinging and tumbling, and a pure tumbling
motion at lower shear stress-values.Comment: 4 pages 5 figures submitted to Physical Review Letter
Optimization of nanostructured permalloy electrodes for a lateral hybrid spin-valve structure
Ferromagnetic electrodes of a lateral semiconductor-based spin-valve
structure are designed to provide a maximum of spin-polarized injection
current. A single-domain state in remanence is a prerequisite obtained by
nanostructuring Permalloy thin film electrodes. Three regimes of aspect ratios
are identified by room temperature magnetic force microscopy: (i)
high-aspect ratios of provide the favored remanent single-domain
magnetization states, (ii) medium-aspect ratios to yield
highly remanent states with closure domains and (iii) low-aspect ratios of lead to multi-domain structures. Lateral kinks, introduced to bridge the
gap between micro- and macroscale, disturb the uniform magnetization of
electrodes with high- and medium-aspect ratios. However, vertical flanks help
to maintain a uniformly magnetized state at the ferromagnet-semiconcuctor
contact by domain wall pinning.Comment: revised version, major structural changes, figures reorganized,6
pages, 8 figures, revte
Microscopic model for Bose-Einstein condensation and quasiparticle decay
Sufficiently dimerized quantum antiferromagnets display elementary S=1
excitations, triplon quasiparticles, protected by a gap at low energies. At
higher energies, the triplons may decay into two or more triplons. A strong
enough magnetic field induces Bose-Einstein condensation of triplons. For both
phenomena the compound IPA-CuCl3 is an excellent model system. Nevertheless no
quantitative model was determined so far despite numerous studies. Recent
theoretical progress allows us to analyse data of inelastic neutron scattering
(INS) and of magnetic susceptibility to determine the four magnetic couplings
J1=-2.3meV, J2=1.2meV, J3=2.9meV and J4=-0.3meV. These couplings determine
IPA-CuCl3 as system of coupled asymmetric S=1/2 Heisenberg ladders
quantitatively. The magnetic field dependence of the lowest modes in the
condensed phase as well as the temperature dependence of the gap without
magnetic field corroborate this microscopic model.Comment: 6 pages, 5 figure
Optimization of Short Coherent Control Pulses
The coherent control of small quantum system is considered. For a two-level
system coupled to an arbitrary bath we consider a pulse of finite duration. We
derive the leading and the next-leading order corrections to the evolution
operator due to the non-commutation of the pulse and the bath Hamiltonian. The
conditions are computed that make the leading corrections vanish. The pulse
shapes optimized in this way are given for and pulses.Comment: 9 pages, 6 figures; published versio
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