834 research outputs found
Semantic Shift to Pragmatic Meaning in Shared Decision Making: Situation Theory Perspective
The way humans establish communication depends on the generation and conveyance of meaning. Linguistically, meaning in information is dependent on the meaning that is ascribed to signifiers in the context of the communication. These signifiers can include items such as words, phrases, signs, and symbols. Conveyance of meaning may, however, imprecise and prone to error. The meaning of information in communication may arise from a change in the context in which a signifier is placed (intrinsic), or a change in the paradigm with which the signifier and context are perceived (extrinsic). In simple situations, where paradigms are reconcilable, semantic shift is solely intrinsic. In complex situations, where differing paradigms will generally lead to irreconcilable perspectives (paradoxes and dualities); the semantic shift will be both intrinsic and extrinsic. Decisions are based on an individual\u27s (or individuals\u27 shared) understanding and understanding is in turn contingent on perspective. Decision making will, therefore, be affected by discrepancies in meaning. It is critical to understand the nature of the discrepancies where shared awareness is necessary to enable group decisions. The theoretical construct presented recognizes that (1) a semantic shift may be required where multiple perspectives based on different paradigms come into play and (2) a semantic shift may introduce error, inefficiency, noise or redundancy. Therefore, individual limits can be recognized via shared awareness, which can be studied with situation theory. © 2015 WIT Press
Response
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26159/1/0000236.pd
Simultaneous dual-species laser cooling using an optical frequency comb
We demonstrate 1D simultaneous laser cooling of Rb and Rb atoms
using an optical frequency comb. By adjusting the pulse repetition frequency
and the offset frequency, the frequency comb spectrum is tuned to ensure that
two distinct frequency comb modes are simultaneously red-detuned from the
cooling transitions, one mode for each species. Starting from a pre-cooled
cloud of Rb atoms at above-Doppler temperatures, we show simultaneous
cooling of both species down to the Doppler temperature using two
counter-propagating /-polarized beams from the
frequency comb. The results indicate that simultaneous dual-species frequency
comb cooling does not affect the cooling characteristics of individual atomic
species. The results of this work imply that several atomic species could be
cooled simultaneously using a single frequency comb source. This comb-based
multi-channel laser cooling could bring significant advances in multi-species
atom interferometers for space applications and in the study of multi-species
interactions
Parabolic resonances and instabilities in near-integrable two degrees of freedom Hamiltonian flows
When an integrable two-degrees-of-freedom Hamiltonian system possessing a
circle of parabolic fixed points is perturbed, a parabolic resonance occurs. It
is proved that its occurrence is generic for one parameter families
(co-dimension one phenomenon) of near-integrable, t.d.o. systems. Numerical
experiments indicate that the motion near a parabolic resonance exhibits new
type of chaotic behavior which includes instabilities in some directions and
long trapping times in others. Moreover, in a degenerate case, near a {\it flat
parabolic resonance}, large scale instabilities appear. A model arising from an
atmospherical study is shown to exhibit flat parabolic resonance. This supplies
a simple mechanism for the transport of particles with {\it small} (i.e.
atmospherically relevant) initial velocities from the vicinity of the equator
to high latitudes. A modification of the model which allows the development of
atmospherical jets unfolds the degeneracy, yet traces of the flat instabilities
are clearly observed
Arene oxidation with malonoyl peroxides
Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the
oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol
which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic
labeling, Hammett analysis, EPR investigations and reactivity profile studies is proposed
Naloxone enhancement of DMT and LSD-25 induced suppression of food-rewarded bar pressing behavior in the rat
The narcotic antagonist naloxone was tested to determine its possible interaction with N,N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained to press a bar on a fixed-ratio four schedule (FR 4 ), i.e., every fourth press earned a reward of 0.01 ml sugar sweetened milk. LSD (0.1 mg/kg) or increasing doses of DMT (1.0, 3.2, and 10.0 mg/kg) were administered i.p. to disrupt food-rewarded fixed ratio bar pressing in a dose related fashion. Pretreatment (5–10 min) with behaviorally ineffective doses of naloxone (1.0–5.6 mg/kg) dramatically enhanced the effects of DMT and LSD. The content of DMT in the brain and liver of rats injected with DMT alone (10 mg/kg) and with a 5 min pretreatment of naloxone (3.2 mg/kg) was determined by radiochemical analysis at 30 and 90 min after 14 C-DMT injection. There was no significant difference for either brain or liver 14 C-DMT levels when control DMT rats were compared with the naloxone pretreated rats. These results seem to rule out interference by naloxone with the metabolism of DMT as a mechanism of the observed behavioral potentiation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46408/1/213_2004_Article_BF00431949.pd
Interactions of partial LSD analogs with behavioral disrupting effects of LSD and DMT in the rat
Adult male Holtzman rats were trained to barpress on a schedule whereby every fourth press earned a reward of 0.01 ml of sugar-sweetened milk (FR4). After an i.p. injecton of LSD (0.1 mg/kg) or DMT (3.2 or 10 mg/kg) such barpressing is abolished completely and resumed, usually within an hour, at a rate near the preinjection control rate of pressing. It continues at a steady, uninterrupted pace until animals are removed from the operant chamber one-half hour later. A series of N,N-diethylnipecotamide derivatives were synthesized and tested for their ability to modify the disruptive effect of these hallucinogens. N,N-diethylbutyramide (DBA) and 1-methyl-1,2,5,6-tetrahydropyridine-3-(N,N-diethylcarboxamide) (THPC) were also tested. Pretreatment with a single i.p. injection of any of these compounds (5-40 mg/kg) either had no effect on or else prolonged the duration of hallucinogen-induced cessation of barpressing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22701/1/0000255.pd
Solutions for the General, Confluent and Biconfluent Heun equations and their connection with Abel equations
In a recent paper, the canonical forms of a new multi-parameter class of Abel
differential equations, so-called AIR, all of whose members can be mapped into
Riccati equations, were shown to be related to the differential equations for
the hypergeometric 2F1, 1F1 and 0F1 functions. In this paper, a connection
between the AIR canonical forms and the Heun General (GHE), Confluent (CHE) and
Biconfluent (BHE) equations is presented. This connection fixes the value of
one of the Heun parameters, expresses another one in terms of those remaining,
and provides closed form solutions in terms of pFq functions for the resulting
GHE, CHE and BHE, respectively depending on four, three and two irreducible
parameters. This connection also turns evident what is the relation between the
Heun parameters such that the solutions admit Liouvillian form, and suggests a
mechanism for relating linear equations with N and N-1 singularities through
the canonical forms of a non-linear equation of one order less.Comment: Original version submitted to Journal of Physics A: 16 pages, related
to math.GM/0002059 and math-ph/0402040. Revised version according to
referee's comments: 23 pages. Sign corrected (June/17) in formula (79).
Second revised version (July/25): 25 pages. See also
http://lie.uwaterloo.ca/odetools.ht
Nonintegrability of the two-body problem in constant curvature spaces
We consider the reduced two-body problem with the Newton and the oscillator
potentials on the sphere and the hyperbolic plane .
For both types of interaction we prove the nonexistence of an additional
meromorphic integral for the complexified dynamic systems.Comment: 20 pages, typos correcte
- …