124,306 research outputs found
Exceptional solutions to the eight-vertex model and integrability of anisotropic extensions of massive fermionic models
We consider several anisotropic extensions of the Belavin model, and show
that integrability holds also for the massive case for some specific relations
between the coupling constants. This is done by relating the S-matrix
factorization property to the exceptional solutions of the eight-vertex model.
The relation of exceptional solutions to the XXZ and six-vertex models is also
shown
The influence of the scene on linguistic expectations: Evidence from cross-model priming in visual worlds
- Numerous studies of utterance mediated gaze in visual scenes have demonstrated that sentence processing is not only incremental but also eager: During processing, listeners form expectations about upcoming arguments and make anticipatory eye movements to relevant displayed objects. - In particular, selectional information from verbs has been shown to guide visual attention to appropriate objects; upon hearing “the boy will eat”, listeners start looking at edible objects even before they are mentioned [1, 2]. - While these studies provide valuable insights into semantic processing, it is not clear whether anticipatory eye movements indeed reflect the purely linguistic activation of likely arguments or whether these anticipatory processes are influenced by the circumscribed visual context. - We present a German cross-modal priming experiment in which we examined listeners sensitivity to selectional restrictions between verbs and their object arguments
CROSSING THE NEXT MERIDIAN: THE ECONOMICS OF RURAL-URBAN INTERDEPENDENCE, INSTITUTIONS AND INCOME DISTRIBUTION IN THE AMERICAN WEST
This paper explores and develops three ideas: (1) that the aridity of western North America and its attendant characteristics have fundamentally shaped the work of western agricultural economists and encouraged some distinctive western contributions to the study of economics; (2) that, in order to understand economic relationships that are critical to rural western economic development, economists need to move beyond the standard equilibrium economic models and explore some emerging models of spatial development and institutional change in which the concept of "increasing returns" plays a key role; (3) that the West provides a fine laboratory for testing these frameworks.Institutional and Behavioral Economics,
Nonenzymatic formation of energy-rich lactoyl and glyceroyl thioesters from glyceraldehyde and a thiol
The energy rich thioester, N-acetyl-S-lactoylcysteine, is formed under anaerobic conditions from glyceraldehyde and N-acetylcysteine at ambient temperature in aqueous solutions of sodium phosphate (pH 7.0). The conversion occurs at a rate of about 0.4% per day in reactions with 10 millimoles (mM) glyceraldehyde, 10 mM thiol, and 500 mM sodium phosphate (pH 7.0). Thioester formation proceeds at an estimated efficiency of 76%. The formation of lactoyl thioester most likely occurs by the phosphate catalyzed dehydration of glyceraldehyde to give pyruvaldehyde, which combines with thiol to form a hemithioacetal that rearranges to the thioester. A second energy rich thioester, N-acetyl-S-glyceroylcysteine, is also produced from glyceraldehyde when these reactions are carried out in the presence of oxygen and to a limited extent in the absence of oxygen. In the presence of oxygen the formation of glyceroyl thioester continues until the thiol disappears completely by oxidation. The significance of these reactions to the energetics of the origin of life is discussed
Carbohydrates as a source of energy and matter for the origin of life
Recently, we proposed a new model of early glycolysis in which the oxidation of glyceraldehyde self-hemiacetals yielded energy rich polyglyceric acid instead of energy rich thioesters. In this model, polyglyceric acid not only acts as an energy source for phosphoanhydride synthesis, but also as an autocatalyst that can replicate the sequence of D and L residues in its structure. We began our investigation of this new hypothesis - the triose model - by developing a thermal method for the racemization-free synthesis of polyglyceric acid. The hydrolytic stability and the role of chirality in interactions of polyglyceric acid were studied using this thermal polymer. Next, we established that the 2- and 3-glycerol esters of polyglyceric acid are energy rich by measuring the Gibbs free energy change of hydrolysis of the 2- and 3-glycerol esters of 2 and 3-O-L glyceroyl-glyceric acid methyl ester - a model of polyglyceric acid. Recently, we discovered that glyceraldehyde is bound and oxidized to glyceric acid on the surface of ferric hydroxide and that soluble ferric ion catalyzes the rearrangement of glyceraldehyde to lactic acid. We are exploring the possibility that these reactions could yield polyglyceric acid and polylactic acid under plausible prebiotic conditions
CROSSING THE NEXT MERIDIAN: THE ECONOMICS OF RURAL-URBAN INTERDEPENDENCE, INSTITUTIONS, AND INCOME DISTRIBUTION IN THE AMERICAN WEST
This article explores and develops three ideas: (a) that the aridity of western North America and its attendant characteristics have fundamentally shaped the work of western agricultural economists and encouraged some distinctive western contributions to the study of economics; (b) that in order to understand economic relationships that are critical to rural western economic development, economists need to move beyond the standard equilibrium economic models and explore some emerging models of spatial development and institutional change in which the concept of “"increasing returns”" plays a key role; and (c) that the West provides a fine laboratory for testing these frameworks.Community/Rural/Urban Development,
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