On the Ado Theorem for finite Lie conformal algebras with Levi decomposition

We prove that a finite torsion-free conformal Lie algebra with a splitting solvable radical has a finite faithful conformal representation.Comment: 11 page

On Griess Algebras

In this paper we prove that for any commutative (but in general non-associative) algebra A with an invariant symmetric non-degenerate bilinear form there is a graded vertex algebra V = V₀ + V₂ + V₃ + ..., such that dim V₀ = 1 and V₂ contains A. We can choose V so that if A has a unit e, then 2e is the Virasoro element of V, and if G is a finite group of automorphisms of A, then G acts on V as well. In addition, the algebra V can be chosen with a non-degenerate invariant bilinear form, in which case it is simple

Acceso al mercado de productos lácteos de Europa: Un análisis de equilibrio parcial para evaluar las potenciales ganancias de los exportadores argentinos

A partial equilibrium model is used to quantify price differentials not explained by tax policy and efficiency cost in the international trade of dairy products between Argentina and some countries of European Union (EU). Prices of imports of EU from Argentina and European producer of the domestic variety welfare fall when liberalization of non-tariff barriers are reduced or eliminated as well as European consumer’s welfare and Argentinean exporter’s earnings are increased. A sensibility analysis is carried out, changing substitution and supply elasticity and exporter’s earnings are shown for four alternative stages. The conclusions are that exporters obtain higher earnings by eliminating or reducing non-tariff barriers when substitution elasticity is higher, mainly for cheese. More inelastic supply products obtain higher earnings for Argentinean exporters (mainly in powdered milk). Finally, an alternative stage is explored where elimination of non-tariff barriers results in higher imports from the rest of the world. Results show a greater increase in Argentinean exporter’s earnings for cheese products and lower earnings for powdered milk

Representation of numerosity in posterior parietal cortex

Humans and animals appear to share a similar representation of number as an analog magnitude on an internal, subjective scale. Neurological and neurophysiological data suggest that posterior parietal cortex (PPC) is a critical component of the circuits that form the basis of numerical abilities in humans. Patients with parietal lesions are impaired in their ability to access the deep meaning of numbers. Acalculiac patients with inferior parietal damage often have difficulty performing arithmetic (2 + 4?) or number bisection (what is between 3 and 5?) tasks, but are able to recite multiplication tables and read or write numerals. Functional imaging studies of neurologically intact humans performing subtraction, number comparison, and non-verbal magnitude comparison tasks show activity in areas within the intraparietal sulcus (IPS). Taken together, clinical cases and imaging studies support a critical role for parietal cortex in the mental manipulation of numerical quantities. Further, responses of single PPC neurons in non-human primates are sensitive to the numerosity of visual stimuli independent of low-level stimulus qualities. When monkeys are trained to make explicit judgments about the numerical value of such stimuli, PPC neurons encode their cardinal numerical value; without such training PPC neurons appear to encode numerical magnitude in an analog fashion. Here we suggest that the spatial and integrative properties of PPC neurons contribute to their critical role in numerical cognition

Cocliques of maximal size in the prime graph of a finite simple group

In this paper we continue our investgation of the prime graph of a finite simple group started in http://arxiv.org/abs/math/0506294 (the printed version appeared in [1]). We describe all cocliques of maximal size for all finite simple groups and also we correct mistakes and misprints from our previous paper. The list of correction is given in Appendix of the present paper.Comment: published version with correction

Access to European dairy product markets: A Computable Partial Equilibrium analysis to assess Argentine exporters surplus

A partial equilibrium model is used to quantify price differentials not explained by tax policy and efficiency cost in the international trade of dairy products between Argentina and some countries of European Union (EU). Prices of imports of EU from Argentina and European producer of the domestic variety welfare fall when liberalization of non-tariff barriers are reduced or eliminated as well as European consumer’s welfare and Argentinean exporter’s earnings are increased. A sensibility analysis is carried out, changing substitution and supply elasticity and exporter’s earnings are shown for four alternative stages. The conclusions are that exporters obtain higher earnings by eliminating or reducing non-tariff barriers when substitution elasticity is higher, mainly for cheese. More inelastic supply products obtain higher earnings for Argentinean exporters (mainly in powdered milk). Finally, an alternative stage is explored where elimination of non-tariff barriers results in higher imports from the rest of the world. Results show a greater increase in Argentinean exporter’s earnings for cheese products and lower earnings for powdered milk.Computable partial equilibrium; dairy market; non-tariff barriers

Monotonic Coding of Numerosity in Macaque Lateral Intraparietal Area

As any child knows, the first step in counting is summing up individual elements, yet the brain mechanisms responsible for this process remain obscure. Here we show, for the first time, that a population of neurons in the lateral intraparietal area of monkeys encodes the total number of elements within their classical receptive fields in a graded fashion, across a wide range of numerical values (2–32). Moreover, modulation of neuronal activity by visual quantity developed rapidly, within 100 ms of stimulus onset, and was independent of attention, reward expectations, or stimulus attributes such as size, density, or color. The responses of these neurons resemble the outputs of “accumulator neurons” postulated in computational models of number processing. Numerical accumulator neurons may provide inputs to neurons encoding specific cardinal values, such as “4,” that have been described in previous work. Our findings may explain the frequent association of visuospatial and numerical deficits following damage to parietal cortex in humans

Assessing the efects of eliminating non-tariff barriers over the Argentine Textile Exports

This paper offers a quantification of price differentials not explained by tariff policy and the assessment of efficiency costs burned on different economic agents involved in textile products trade between Argentina (exporter) and Brazil (domestic producer). Simulations are carried out to show the effects of the distortion of price differentials, considered like non tariff barriers or a set of them and others obstacle to trade. From the removal of non tariff barriers results that consumers and exporters obtain grater consumer surplus and profits, respectively, while domestic producers loose part of their producer surplus. Consumers and exporters are better because of changes in terms of trade; in some products consumers obtain graters benefits than exporters and vice versa. Likewise, changes in elasticities (direct elasticity of supply and demand) were simulated to observe distortions in previous results.Textile sector; computable partial equilibrium; commercial policy