Abstract:
This study develops a methodology to analize the demand for health services. It is based on dichotomic regressions aimed at determining why consumers prefer certain services and do not demand other. It discusses the possible impact on the number of medical vis its of changes in health costs and households income, and focuses on highlighting some criteria regarding the efficiency and fairness of current policies of coverage and finance. The empirical analysis uses information from the National Survey on Health Expenditures (Endesa, 1995), which obtained data on health and demographic variables from a sample of 1,290 households and 6,366 individuals. This study develops a methodology to analize the demand for health services. It is based on dichotomic regressions aimed at determining why consumers prefer certain services and do not demand other. It discusses the possible impact on the number of medical vis its of changes in health costs and households income, and focuses on highlighting some criteria regarding the efficiency and fairness of current policies of coverage and finance. The empirical analysis uses information from the National Survey on Health Expenditures (Endesa, 1995), which obtained data on health and demographic variables from a sample of 1,290 households and 6,366 individuals.

Abstract:
We determine explicitly the irreducible components of the singular locus of any Schubert variety for GL_n(K), K being an algebraically closed field of arbitrary characteristic. We also describe the generic singularities along these components. The case of covexillary Schubert varieties was solved in an earlier work of the author [Ann. Inst. Fourier vol. 51 fasc. 2 (2001), 375-393]. Here, we first exhibit some irreducible components of the singular locus of X_w, by describing the generic singularity along each of them. Let S_w be the union of these components. As mentioned above, the equality S_w = Sing X_w is known for covexillary varieties, and we base our proof of the general case on this result. More precisely, we study the exceptional locus of certain quasi-resolutions of a non-covexillary Schubert variety X_w, and we relate the intersection of these loci to S_w. Then, by induction on the dimension, we can establish the equality.

Abstract:
In this paper, we are considering the Cauchy problem of the nonlinear heat equation $u\_t -\Delta u= u^{3 },\ u(0,x)=u\_0$. After extending Y. Meyer's result establishing the existence of global solutions, under a smallness condition of the initial data in the homogeneous Besov spaces $\dot{B}\_{p}^{-\sigma, \infty}(\mathbb{R}^{3})$, where $3 \textless{} p \textless{} 9$ and $\sigma=1-3/p$, we prove that initial data $u\_0\in \mathcal{S}(\mathbb{R}^{3})$, arbitrarily small in ${\dot B^{-2/3,\infty}\_{9}}(\mathbb{R}^{3})$, can produce solutions that explode in finite time. In addition, the blowup may occur after an arbitrarily short time.

Abstract:
presidential elections in brazil have been regularly a dispute between pt and psdb. no third alternative has been able to threaten the control these parties have over the majority of the electorate. the way presidential elections are structured has an influence over the elections at state level, reproducing the same pattern. the parties' strategy, negotiating the launching and withdrawal of candidacies, is the key to understanding the dynamics of electoral disputes in brazil.

Abstract:
a checklist for species and a key for genera of epiphyte ferns that occur on the roots and trunks of tree ferns within both cyatheaceae and dicksoniaceae from cloud forest of venezuela, are presented

Abstract:
there is an extensive literature to study the effects of the judiciary power on how political systems work. is there a judicialization of politics? our point is that the answer to that question is connected to theoretical questions about the ways to prove and where scholars should look in order to detect the effect of judiciary in democratic systems. in this work we analyze the judicialization of politics under the perspective of the definition of the rules of electoral competition. in order to prove our argument, this article studies how tse (brazilian judiciary court) rules coalitions in brazil's political system, known as "verticaliza？？o" _the uniformity of party coalitions at state and federal levels. our case study shows that tse, in fact, not only interprets the law but, actually, establishes rules, taking the place of the legislative body _which, in turn, made another move. the analysis suggests that the question of judiciary of politics should be seen as an strategic interaction between the two powers.

Abstract:
this paper is motivated by the result of berge who generalized tutte's theorem which states that: given a graph g with |v(g)| vertices and n(g) the number of edges in a maximum matching, then there is a subset x í v(g) such that |v(g)|+|x| - w(g\x) - 2n( g)=0, where w(g\x) denotes the number of odd components of g\x, such expression is called tutte-berge's equation associated to g, denoted by t(g;x)=0. these graphs are then studied from solutions of t(g;x)=0. a graph g is called immersible graph if and only if, its associated equation t(g;x)=0 has at least one non-emptyset for x, and it is non-immersible graph if and only if, the unique solution to t(g;x)=0 is the emptyset. the main result of this work is the characterization of immersible graphs via complete antifactor sets, moreover we prove that factorizable graphs are included in the class of immersible graphs.

Abstract:
during the 1990's, brazil experienced a remarkable increase in its unemployment rate, the intensity of this process was higher for unskilled and semiskilled workers than for skilled. the objective of this paper is to evaluate the role of skill-biased shifts in the structure of labor demand for the patterns of unemployment rate by skill. in order to do so, a model with two kinds of shocks, aggregate and relative, was used. the aggregate shocks are those that are equal to all skill groups, and the relative ones are related to labor demand structural changes. the parameters of the model were estimated using pnads (pesquisa nacional por amostra de domicílio) data from 1990 to 1999. then, the impact of each shock on unemployment rate by skill was evaluated. according to the evidence found in this paper, the demand for skilled workers increased compared to semi-skilled and unskilled, leading to a reduction on skilled workers relative unemployment rate.

Abstract:
the present text seeks to discuss the matter of interpretation, especially during literacy practices in school context, reacting to theoretical conceptions which indicate the reflections presented here and which position language as an instrument to represent the world or as praxis, and also those ones which are positioned in the tension between those poles. therefore, the objective of this work is to defend a more poetic attitude towards the work of interpretation during literacy practices in school context, adopting a posture of reaction to the text, which involves the notion of reading acts as performances, and not as a decoding or a discovery exercise.

Abstract:
the present text seeks to discuss the matter of interpretation, especially during literacy practices in school context, reacting to theoretical conceptions which indicate the reflections presented here and which position language as an instrument to represent the world or as praxis, and also those ones which are positioned in the tension between those poles. therefore, the objective of this work is to defend a more poetic attitude towards the work of interpretation during literacy practices in school context, adopting a posture of reaction to the text, which involves the notion of reading acts as performances, and not as a decoding or a discovery exercise.