1,160,541 research outputs found
Automorphism groups of some AG codes
We show that in many cases, the automorphism group of a curve and the
permutation automorphism group of a corresponding AG code are the same. This
generalizes a result of Wesemeyer beyond the case of planar curves.Comment: added a reference, fixed error in remark
State Litigation during the Obama Administration: Diverging Agendas in an Era of Polarized Politics
Throughout the Obama Administration, state attorneys general (AGs) have collaborated on several high-profile political issues. To get a fuller picture of this contemporary AG activism, this article analyzes AG participation in lawsuits and amicus curiae briefs before the U.S. Supreme Court across three presidential administrations. The results suggest that AGs’ agendas have increasingly diverged throughout the Obama Administration, reflecting greater vertical conflict between AGs and the federal government as well as horizontal conflict among AGs themselves. Several factors have contributed to this development, including the broader polarization of American politics, intensified activism among Republican AGs, and increased collaborations between AGs and ideological interest groups. Much as with partisan contestation in other venues, these AG conflicts show few signs of abating
A hexahomotrioxacalix[3]arene-based ditopic receptor for alkylammonium ions controlled by Ag + ions 4
A receptor cone-1 based on a hexahomotrioxacalix[3]arene bearing three pyridyl groups 21 was successfully synthesized, which has a C3-symmetric conformation and is capable of binding 22 alkylammonium and metal ions simultaneously in a cooperative fashion. It can bind 23 alkylammonium ions through the -cavity formed by three aryl rings. This behaviour is consistent 24 with the cone-in/cone-out conformational rearrangement needed to reorganize the cavity for 25 endo-complexation. As a C3-symmetrical pyridyl-substituted calixarene, receptor cone-1 can also 26 bind a Ag + ion and the nitrogen atoms are turned towards the inside of the cavity and interact with 27 Ag +. After complexation of tris(2-pyridylamide) derivative receptor cone-1 with Ag + , the original 28 C3-symmetry was retained and higher complexation selectivity for n-BuNH3 + versus t-BuNH3 + was 29 observed. Thus, it is believed that this receptor will have a role to play in the sensing, detection, and 30 recognition of Ag + and n-BuNH3 + ions. 3
On Modulo AG-groupoids
A groupoid G is called an AG-groupoid if it satisfies the left invertive law:
(ab)c = (cb)a. An AG-group G, is an AG-groupoid with left identity e \in G
(that is, ea = a for all a \in G) and for all a \in G there exists a' \in G
such that a.a' = a'.a = e. In this article we introduce the concept of
AG-groupoids (mod n) and AG-group (mod n) using Vasantha's constructions [1].
This enables us to prove that AG-groupoids (mod n) and AG-groups (mod n) exist
for every integer n \geq 3. We also give some nice characterizations of some
classes of AG-groupoids in terms of AG-groupoids (mod n).Comment: 10 page
Selection of bioantagonistic bacteria to be used in biological control of Rhizoctonia solani in tomato
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602011000100002&lng=es&nrm=isoBacteria from the rhizoplane and surrounding soil of healthy and Rhizoctonia
solani diseased tomato plants, cropped in greenhouse of the V Region of Chile,
were collected. The best bacterial strains, based on their ability to control
development of three R. solani isolates (identified as belonging to the anastomosis
groups AG-2-1, AG-4), were identified as B. subtilis (one isolate) and B. lentimorbus (two
different isolates). All bacterial isolates resulted effective for the in vitro control of growth of all
R. solani isolates, where the control mechanisms used by the bacteria do not involve the
secretion of fungal cell wall hydrolytic enzymes. R. solani AG-2-1 was more sensitive than R.
solani AG-4. On the other hand, all bacteria grew well in conditions similar to those that can be
found at the field level (considering pH, salinity, Fe3+ and temperature) and showed a good
capacity of tomato root colonization. These results suggest that the B. subtilis and B.
lentimorbus isolates studied have an excellent potential to be used as biocontrol agents of R.
solani in tomato greenhouses at the field level
The endothelial glycocalyx prefers albumin for evoking shear stress-induced, nitric oxide-mediated coronary dilatation
Background: Shear stress induces coronary dilatation via production of nitric oxide ( NO). This should involve the endothelial glycocalyx ( EG). A greater effect was expected of albumin versus hydroxyethyl starch ( HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. Methods: Isolated hearts ( guinea pigs) were perfused at constant pressure with Krebs-Henseleit buffer augmented with 1/3 volume 5% human albumin or 6% HES ( 200/0.5 or 450/0.7). Coronary flow was also determined after EG digestion ( heparinase) and with nitro-L-arginine ( NO-L-Ag). Results: Coronary flow ( 9.50 +/- 1.09, 5.10 +/- 0.49, 4.87 +/- 1.19 and 4.15 +/- 0.09 ml/ min/ g for `albumin', `HES 200', `HES 450' and `control', respectively, n = 5-6) did not correlate with perfusate viscosity ( 0.83, 1.02, 1.24 and 0.77 cP, respectively). NO-L-Ag and heparinase diminished dilatation by albumin, but not additively. Alone NO-L-Ag suppressed coronary flow during infusion of HES 450. Electron microscopy revealed a coronary EG of 300 nm, reduced to 20 nm after heparinase. Cultured endothelial cells possessed an EG of 20 nm to begin with. Conclusions: Albumin induces greater endothelial shear stress than HES, despite lower viscosity, provided the EG contains negative groups. HES 450 causes some NO-mediated dilatation via even a rudimentary EG. Cultured endothelial cells express only a rudimentary glycocalyx, limiting their usefulness as a model system. Copyright (c) 2007 S. Karger AG, Basel
Relative hyperbolicity and relative quasiconvexity for countable groups
We lay the foundations for the study of relatively quasiconvex subgroups of
relatively hyperbolic groups. These foundations require that we first work out
a coherent theory of countable relatively hyperbolic groups (not necessarily
finitely generated). We prove the equivalence of Gromov, Osin, and Bowditch's
definitions of relative hyperbolicity for countable groups.
We then give several equivalent definitions of relatively quasiconvex
subgroups in terms of various natural geometries on a relatively hyperbolic
group. We show that each relatively quasiconvex subgroup is itself relatively
hyperbolic, and that the intersection of two relatively quasiconvex subgroups
is again relatively quasiconvex. In the finitely generated case, we prove that
every undistorted subgroup is relatively quasiconvex, and we compute the
distortion of a finitely generated relatively quasiconvex subgroup.Comment: 44 pages, 2 figures. Version 3 addresses some minor concerns of the
referee regarding the exposition. To appear in AG
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