Arcbodies

1983 ◽  
Vol 94 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Maria Teresa Lozano
Keyword(s):  
Recent Work ◽  
Incompressible Surface ◽  
Incompressible Surfaces ◽  
Positive Genus

A Haken manifold is a compact, orientable, irreducible 3-manifold which contains a properly embedded 2-sided, incompressible surface of positive genus. These manifolds are important in connection with the work of Haken, Waldhausen and the more recent work of Thurston (8). Thus it is interesting to investigate criteria for testing incompressible surfaces on 3-manifolds.

scholarly journals Invariant incompressible surfaces in reducible 3-manifolds

2018 ◽  
Vol 39 (11) ◽  
pp. 3136-3143 ◽  
Author(s):  
CHRISTOFOROS NEOFYTIDIS ◽  
SHICHENG WANG
Keyword(s):  
Mapping Class Group ◽  
Class Group ◽  
Mapping Class ◽  
Incompressible Surface ◽  
Mapping Torus ◽  
Incompressible Surfaces ◽  
Hyperbolic Automorphism

We study the effect of the mapping class group of a reducible 3-manifold $M$ on each incompressible surface that is invariant under a self-homeomorphism of $M$ . As an application of this study we answer a question of F. Rodriguez Hertz, M. Rodriguez Hertz, and R. Ures: a reducible 3-manifold admits an Anosov torus if and only if one of its prime summands is either the 3-torus, the mapping torus of $-\text{id}$ , or the mapping torus of a hyperbolic automorphism.

scholarly journals INCOMPRESSIBLE SURFACES AND (1, 1)-KNOTS

2006 ◽  
Vol 15 (07) ◽  
pp. 935-948 ◽  
Author(s):  
MARIO EUDAVE-MUÑOZ
Keyword(s):  
Lens Space ◽  
Regular Neighborhood ◽  
Incompressible Surface ◽  
Special Position ◽  
Incompressible Surfaces ◽  
Toroidal Graph ◽  
Tunnel Number ◽  
Tunnel Number One Knots

Let M be S3, S1 × S2, or a lens space L(p, q), and let k be a (1, 1)-knot in M. We show that if there is a closed meridionally incompressible surface in the complement of k, then the surface and the knot can be put in a special position, namely, the surface is the boundary of a regular neighborhood of a toroidal graph, and the knot is level with respect to that graph. As an application we show that for any such M there exist tunnel number one knots which are not (1, 1)-knots.

Accidental surfaces in knot complements

2000 ◽  
Vol 09 (06) ◽  
pp. 725-733 ◽  
Author(s):  
Kazuhiro Ichihara ◽  
Makoto Ozawa
Keyword(s):  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Incompressible Surface ◽  
Incompressible Surfaces ◽  
Parallel Surface ◽  
Seifert Surfaces ◽  
Knot Complements ◽  
Necessary And Sufficient

It is well known that for many knot classes in the 3-sphere, every closed incompressible surface in their complements contains an essential loop which is isotopic into the boundary of the knot exterior. In this paper, we investigate closed incompressible surfaces in knot complements with this property. We show that if a closed, incompressible, non-boundary-parallel surface in a knot complement has such loops, then they determine the unique slope on the boundary of the knot exterior. Moreover, if the slope is non-meridional, then such loops are mutually isotopic in the surface. As an application, a necessary and sufficient condition for knots to bound totally knotted Seifert surfaces is given.

2-STRING FREE TANGLES AND INCOMPRESSIBLE SURFACES

2009 ◽  
Vol 18 (08) ◽  
pp. 1081-1087 ◽  
Author(s):  
YANNAN LI
Keyword(s):  
Positive Integer ◽  
Incompressible Surface ◽  
Connected Sum ◽  
Incompressible Surfaces

Suppose k is a connected sum of two knots, one of which admits a 2-string essential free tangle decomposition, then the exterior of k contains an incompressible surface of genus n for each positive integer n.

Centralizers of reflections in crystallographic groups

1982 ◽  
Vol 92 (1) ◽  
pp. 79-91 ◽  
Author(s):  
T. Baskan ◽  
A. M. Macbeath
Keyword(s):  
Fundamental Group ◽  
Hyperbolic Plane ◽  
Universal Covering ◽  
Interesting Case ◽  
Discrete Groups ◽  
Incompressible Surface ◽  
Crystallographic Groups ◽  
Incompressible Surfaces ◽  
Universal Covering Space ◽  
Manifold Theory

The study of hyperbolic 3-manifolds has recently been recognized as an increasingly important part of 3-manifold theory (see (9)) and for some time the presence of incompressible surfaces in a 3-manifold has been known to be important (see, for example, (4)). A particularly interesting case occurs when the incompressible surface unfolds in the universal covering space into a hyperbolic plane. The fundamental group of the surface is then contained in the stabilizer of the plane, or, what is the same thing, in the centralizer of the reflection defined by the plane. This is one motivation for studying centralizers of reflections in discrete groups of hyperbolic isometries, or, as we shall call them, hyperbolic crystallographic groups.

What sentimentalists should say about emotion

2019 ◽  
Vol 42 ◽  
Author(s):  
Charlie Kurth
Keyword(s):  
Moral Judgment ◽  
Recent Work ◽  
Relevant Information ◽  
Moral Cognition ◽  
Multilevel Structure

Abstract Recent work by emotion researchers indicates that emotions have a multilevel structure. Sophisticated sentimentalists should take note of this work – for it better enables them to defend a substantive role for emotion in moral cognition. Contra May's rationalist criticisms, emotions are not only able to carry morally relevant information, but can also substantially influence moral judgment and reasoning.

The Sun as a Magnetic Star

1976 ◽  
Vol 32 ◽  
pp. 457-463
Author(s):  
John M. Wilcox ◽  
Leif Svalgaard
Keyword(s):  
Recent Work ◽  
Rotation Axis ◽  
Polar Field ◽  
Magnetic Star ◽  
Rotational Axis ◽  
Field Variation ◽  
The Sun ◽  
Arbitrary Angle ◽  
Solar Magnetism ◽  
Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

Microstructural comparison of synthetic bioceramics with natural bioceramics

1991 ◽  
Vol 49 ◽  
pp. 38-39
Author(s):  
Shulin Wen ◽  
Jingwei Feng ◽  
A. Krajewski ◽  
A. Ravaglioli
Keyword(s):  
Recent Work ◽  
Human Body ◽  
Human Tissues ◽  
Main Constituent ◽  
Laboratory Furnace ◽  
Chinese Adult ◽  
Human Enamel ◽  
Biological Compatibility ◽  
Synthetic Hydroxyapatite ◽  
Synthetic Work

Hydroxyapatite bioceramics has attracted many material scientists as it is the main constituent of the bone and the teeth in human body. The synthesis of the bioceramics has been performed for years. Nowadays, the synthetic work is not only focused on the hydroapatite but also on the fluorapatite and chlorapatite bioceramics since later materials have also biological compatibility with human tissues; and they may also be very promising for clinic purpose. However, in comparison of the synthetic bioceramics with natural one on microstructure, a great differences were observed according to our previous results. We have investigated these differences further in this work since they are very important to appraise the synthetic bioceramics for their clinic application.The synthetic hydroxyapatite and chlorapatite were prepared according to A. Krajewski and A. Ravaglioli and their recent work. The briquettes from different hydroxyapatite or chlorapatite powders were fired in a laboratory furnace at the temperature of 900-1300°C. The samples of human enamel selected for the comparison with synthetic bioceramics were from Chinese adult teeth.

Substrate specificity and inducibility of TACE (tumour necrosis factor α-converting enzyme) revisited: the Ala-Val preference, and induced intrinsic activity

2003 ◽  
Vol 70 ◽  
pp. 39-52 ◽  
Author(s):  
Roy A. Black ◽  
John R. Doedens ◽  
Rajeev Mahimkar ◽  
Richard Johnson ◽  
Lin Guo ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Recent Work ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Transforming Growth Factor ◽  
Intrinsic Activity ◽  
Converting Enzyme ◽  
Tumour Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

Tumour necrosis factor α (TNFα)-converting enzyme (TACE/ADAM-17, where ADAM stands for a disintegrin and metalloproteinase) releases from the cell surface the extracellular domains of TNF and several other proteins. Previous studies have found that, while purified TACE preferentially cleaves peptides representing the processing sites in TNF and transforming growth factor α, the cellular enzyme nonetheless also sheds proteins with divergent cleavage sites very efficiently. More recent work, identifying the cleavage site in the p75 TNF receptor, quantifying the susceptibility of additional peptides to cleavage by TACE and identifying additional protein substrates, underlines the complexity of TACE-substrate interactions. In addition to substrate specificity, the mechanism underlying the increased rate of shedding caused by agents that activate cells remains poorly understood. Recent work in this area, utilizing a peptide substrate as a probe for cellular TACE activity, indicates that the intrinsic activity of the enzyme is somehow increased.

Recent work on group III antimonides and arsenides

Physica ◽  
1954 ◽  
Vol 3 (7-12) ◽  
pp. 1065-1067
Author(s):  
H HROSTOWSKI ◽  
M TANENBAUM
Keyword(s):  
Recent Work ◽  
Group Iii
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