1,276 research outputs found
Fine structure and functional morphology of the mouthparts of a male Veigaia sp (Gamasida: Veigaiidae) with remarks on the spermatodactyl and related sensory structures
Mites of the genus Veigaia are common gamasid
inhabitants of forest litter. They engage in the
peculiar reproductive strategy of podospermy which, along
with other morphological and behavioral adaptations, involves
modification of the chelicerae of the relatively rare
males into gonopods. Each movable digit is provided with
an appendage (spermatodactyl) that is involved in sperm
transfer. We describe the gross anatomy, fine structure,
and functional morphology of the mouthparts of a male
Veigaia species and give ultrastructural details for the
corniculi, laciniae, preoral cavity, labrum, pharynx, and
movable and fixed digits. The fine structure of the spermatodactyl
is illustrated here for the first time in detail. A
semischematic reconstruction of the gnathosoma and
spermatodactyl is provided. The spermatodactyl is totally
fused with the movable digit and a sperm transfer duct
runs along its entire length. This duct starts at the adaxial
base of the movable digit, continues inside the digit into
the tube of the spermatodactyl, and finally opens at the
distal abaxial surface of the spermatodactyl. Several sensory
structures associated with the spermatodactyl probably
provide the male with mechanical and chemical
clues
Removal of filler material from large high energy formed parts
Filler material is removed by applying steam heat at 88.99 C to underside of workpiece and allowing filler to melt and drain from the waffle grids
Recommended from our members
Allogynaspis flechtmanni, a new genus and species of the subfamily Macrochelinae (Acari: Mesostigmata: Macrochelidae) from southeastern Brazil, with comments on cheliceral dentition, reproductive strategies, and postepigynal platelets
Allogynaspis flechtmanni n. gen., n. sp. is described from litter bordering a stream in a forested area of Itatiaia National Park in southeastern Brazil. Although it shares a number of traits with the free-living macrochelid genera Nothrholaspis and Macrholaspis, the new species presents a unique combination of characters that argues against its inclusion in either genus, or in any other recognised macrochelid genus. A dichotomous key that distinguishes Allogynaspis from related macrocheline genera is included in the text
On the Bergman representative coordinates
We study the set where the so-called Bergman representative coordinates (or
Bergman functions) form an immersion. We provide an estimate of the size of a
maximal geodesic ball with respect to the Bergman metric, contained in this
set. By concrete examples we show that these estimates are the best possible.Comment: 20 page
Towards new background independent representations for Loop Quantum Gravity
Recently, uniqueness theorems were constructed for the representation used in
Loop Quantum Gravity. We explore the existence of alternate representations by
weakening the assumptions of the so called LOST uniqueness theorem. The
weakened assumptions seem physically reasonable and retain the key requirement
of explicit background independence. For simplicity, we restrict attention to
the case of gauge group U(1).Comment: 22 pages, minor change
Electronic Raman scattering in YBCO and other superconducting cuprates
Superconductivity induced structures in the electronic Raman spectra of
high-Tc superconductors are computed using the results of ab initio LDA-LMTO
three-dimensional band structure calculations via numerical integrations of the
mass fluctuations, either in the whole 3D Brillouin zone or limiting the
integrations to the Fermi surface. The results of both calculations are rather
similar, the Brillouin zone integration yielding additional weak structures
related to the extended van Hove singularities. Similar calculations have been
performed for the normal state of these high-Tc cuprates. Polarization
configurations have been investigated and the results have been compared to
experimental spectra. The assumption of a simple d_(x^2-y^2)-like gap function
allows us to explain a number of experimental features but is hard to reconcile
with the relative positions of the A1g and B1g peaks.Comment: 14 pages, LaTeX (RevTeX), 5 PostScript figures, uses multicol.sty,
submitted to PR
Chromosomal rearrangement segregating with adrenoleukodystrophy: associated changes in color vision.
3D integrated superconducting qubits
As the field of superconducting quantum computing advances from the few-qubit
stage to larger-scale processors, qubit addressability and extensibility will
necessitate the use of 3D integration and packaging. While 3D integration is
well-developed for commercial electronics, relatively little work has been
performed to determine its compatibility with high-coherence solid-state
qubits. Of particular concern, qubit coherence times can be suppressed by the
requisite processing steps and close proximity of another chip. In this work,
we use a flip-chip process to bond a chip with superconducting flux qubits to
another chip containing structures for qubit readout and control. We
demonstrate that high qubit coherence (, s) is
maintained in a flip-chip geometry in the presence of galvanic, capacitive, and
inductive coupling between the chips
Twin paradox and space topology
If space is compact, then a traveller twin can leave Earth, travel back home
without changing direction and find her sedentary twin older than herself. We
show that the asymmetry between their spacetime trajectories lies in a
topological invariant of their spatial geodesics, namely the homotopy class.
This illustrates how the spacetime symmetry invariance group, although valid
{\it locally}, is broken down {\it globally} as soon as some points of space
are identified. As a consequence, any non--trivial space topology defines
preferred inertial frames along which the proper time is longer than along any
other one.Comment: 6 pages, latex, 3 figure
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