420 research outputs found
Diclidophora nezumiae sp. n. (Monogenea: Diclidophoridae) and Its Ecological Relationships with the Macrourid Fish Nezumia bairdii (Goode and Bean, 1877)
Diclidophora nezumiae sp. n. is described from the gills of the rat-tail fish Nezumia bairdii (Goode and Bean, 1877) taken from the environs of Hudson Submarine Canyon in the northwest Atlantic. The host-parasite relationships were studied in the host population. The new species is most similar to small species of Diclidophora having short bodies that taper to maximum width at the level of the first pair of clamps. It may be differentiated from other species by the following: clamps wider than long, noticeably decreasing in size posteriorly; lamellate extension of sclerite b does not fuse with sclerite c1; unsclerotized diaphragm; a relatively small clamp sucker; 10-13 cirrus hooks; 10-30 intercecal, postovarian testes; Unilobed seminal receptacle; filamented eggs; and body dimensions. Of 378 N. bairdii specimens examined, 106 (28%) were infected with 1-21 D. nezumiae per host. The parasite occurred most frequently on filaments of the first gill arch. Infected fish ranged from 61-428mm in total length. They were collected at depths of 300-1900 m. Both incidence and intensity of infection were greater for hosts collected between 700- 1000 m. Depth of capture of the host was more strongly correlated with fish abundance than with fish size
Methyl 5,6-dimethoxy-1H-indole-2-carboxylate
The title compound, C12H13NO4, was prepared as a precursor to an indole derivative with possible antimitotic properties. The molecule is very nearly planar; the maximum deviation of any non-H atom from the mean plane of the indole ring is 0.120 (3) Å for each of two methoxy C atoms. The pairs of molecules related by the inversion centre at (0,0,) are connected by two symmetry-equivalent N—H⋯O hydrogen bonds, while the pairs of molecules related by the inversion centre at (0,0,0) exhibit a π-stacking interaction of the indole rings, with an interplanar separation of 3.39 (3) Å
5-Methoxy-1-(3,4,5-trimethoxyphenyl)-1H-indole
The title compound, C18H19NO4, was prepared as an indole derivative with possible antimitotic properties. The planes of the indole and trimethoxyphenyl rings make a dihedral angle of 45.35 (5)° with one another. In the crystal, molecules related by a twofold screw axis exhibit arene C—H⋯arene-π interactions which are 3.035 (1) Å in length
Bis(2-naphthylmethyl)diphenylsilane
The title compound, C34H28Si, was prepared as an internal standard for diffusion-ordered NMR spectroscopy. The four ligands are arranged tetrahedrally around the Si atom. The two naphthalene systems are nearly perpendicular, making an angle of 86.42 (4)° with one another. A naphthalene system and a phenyl ring are also nearly perpendicular, making an angle of 86.18 (6)° with one another. In the crystal, the molecules pack in columns parallel to the a axis, and exhibit arene C—H⋯π(arene) interactions both within and between columns
Bis(benzenethiolato)(2,2′-biquinoline)zinc(II)
The title compound, [Zn(C6H5S)2(C18H12N2)], was prepared as a model for future complexes that will be incorporated into light-harvesting arrays. The ZnII atom lies on a twofold rotation axis and the ligands are arranged tetrahedrally around this atom. The benzenethiolate ligand and the biquinoline ligand are nearly perpendicular to one another, making a dihedral angle of 84.09 (5)°. The biquinoline ligand is nearly planar, with a maximum deviation of 0.055 (3) Å from the mean plane of the ring system. In the crystal, the molecules pack in a manner such that the biquinoline ligands are parallel to one another, with a π–π interaction [interplanar distance = 3.38 (1) Å] with the neighboring biquinoline ligand
Cooling the Collective Motion of Trapped Ions to Initialize a Quantum Register
We report preparation in the ground state of collective modes of motion of
two trapped 9Be+ ions. This is a crucial step towards realizing quantum logic
gates which can entangle the ions' internal electronic states. We find that
heating of the modes of relative ion motion is substantially suppressed
relative to that of the center-of-mass modes, suggesting the importance of
these modes in future experiments.Comment: 5 pages, including 3 figures. RevTeX. PDF and PostScript available at
http://www.bldrdoc.gov/timefreq/ion/qucomp/papers.htm . final (published)
version. Eq. 1 and Table 1 slightly different from original submissio
An osseous lesion in a 10-year-old boy with Hodgkin's lymphoma: a case report
<p>Abstract</p> <p>Introduction</p> <p>Osseous involvement of Hodgkin's lymphoma is uncommon. When osteolytic lesions are seen on imaging it is important to evaluate potential other causes.</p> <p>Case presentation</p> <p>We report the case of a 10-year-old Caucasian boy who presented to our facility with a bony lesion of the right clavicle and enlarged cervical lymph nodes. A simultaneous biopsy of the lymph node and of the osteolytic process of his right proximal clavicle was performed and revealed two different kinds of lesions: a mixed cellularity Hodgkin's lymphoma and an osteochondroma.</p> <p>Conclusions</p> <p>Since the latter is a common benign bone tumor, which should not interfere with the staging of the lymphoma, we emphasize the importance of ensuring that all efforts are made to acquire a diagnostic biopsy of all atypical lesions.</p
A Quantum Scattering Interferometer
The collision of two ultra-cold atoms results in a quantum-mechanical
superposition of two outcomes: each atom continues without scattering and each
atom scatters as a spherically outgoing wave with an s-wave phase shift. The
magnitude of the s-wave phase shift depends very sensitively on the interaction
between the atoms. Quantum scattering and the underlying phase shifts are
vitally important in many areas of contemporary atomic physics, including
Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic
clocks, and magnetically-tuned Feshbach resonances. Precise measurements of
quantum scattering phase shifts have not been possible until now because, in
scattering experiments, the number of scattered atoms depends on the s-wave
phase shifts as well as the atomic density, which cannot be measured precisely.
Here we demonstrate a fundamentally new type of scattering experiment that
interferometrically detects the quantum scattering phase shifts of individual
atoms. By performing an atomic clock measurement using only the scattered part
of each atom, we directly and precisely measure the difference of the s-wave
phase shifts for the two clock states in a density independent manner. Our
method will give the most direct and precise measurements of ultracold
atom-atom interactions and will place stringent limits on the time variations
of fundamental constants.Comment: Corrected formatting and typo
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