Malthus to Solow

A unified growth theory is developed that accounts for the roughly constant living standards displayed by world economies prior to 1800 as well as the growing living standards exhibited by modem industrial economies. Our theory also explains the industrial revolution, which is the transition from an era when per capita incomes are stagnant to one with sustained growth. This transition is inevitable given positive rates oftotal factor productivity growth. We use a standard growth mode1 with one good and two available techno10gies. The first, denoted the "Malthus" technology, requires 1and, labor and reproducible capital as inputs. The second, denoted the "Solow" technology, does not require land. We show that in the earIy stages of development, only the Malthus technology is used and, due to population growth, living standards are stagnant despite technological progresso Eventually, technological progress causes the Solow technology to become profitable and both technologies are employed. At this point, living standards improve since population growth has less influence on per capita income growth. In the limit, the economy behaves like a standard Solow growth model.

Debt and default in a growth model

This paper presents a small open economy model with capital accumulation and without commitment to repay debt. The optimal debt contract specifies debt relief following bad shocks and debt increase following good shocks and brings first order benefits if the country's borrowing constraint is binding. Countries with less capital (with higher marginal productivity of capital) have a higher debt-GDP ratio, are more likely to default on uncontingent bonds, require higher debt relief after bad shocks and pay a higher spread over treasury. Debt relief prescribed by the optimal contract following the interest rate hikes of 1980-81 is more than half of the debt forgiveness obtained by the main Latin American countries through the Brady agreements.

Fission track and U-Pb in situ dating applied to detrital zircon from the Vale do Rio do Peixe Formation, Bauru Group, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

From Amazonia to the Atlantic forest: Molecular phylogeny of Phyzelaphryninae frogs reveals unexpected diversity and a striking biogeographic pattern emphasizing conservation challenges

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Unfinished business in the international dialogue on debt

Includes bibliography

O cálculo e a invenção na poética de Stockhausen

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Public debt sustainability in the Caribbean

This paper analyses public debt in the most indebted Caribbean countries – i.e. Barbados, Belize, Guyana, Jamaica, Antigua and Barbuda, Dominica, Grenada, and St. Kitts and Nevis – from the standpoint of its sustainability. A level of debt is deemed to be sustainable when the debt-to-GDP ratio remains constant or declines. The concept of sustainability is closely linked to that of solvency. A government is solvent if the net present value of its future primary balances (i.e. that excludes interest payments) is equal to or greater than the present value of public debt stock. It can be demonstrated that if the debt-to-GDP ratio is not on an explosive path, that it either stable or decreasing, the solvency condition holds. It is worth noting that the concept of fiscal sustainability addressed in this paper differs from that of optimality of public debt. The analysis that follows is intended to determine whether the service of the current debt levels is consistent with the fiscal stance. Therefore, it does not set out to identify the target debt level based on any optimality criteria. The next section presents the main features of different theoretical approaches to analyse public debt sustainability.1 Section II discusses the situation of public debt in the Caribbean countries showing different indicators; Section III analyses debt sustainability in countries with access to market financing; Section IV does the same in Guyana – a country dependent on concessional financing and, as such, included in the Highly Indebted Poor Countries (HIPC) Initiative – and the countries of the Eastern Caribbean Currency Union (ECCU). Sections V and VI go beyond debt levels as determinants of fiscal sustainability, highlighting the importance of the currency composition of debt and the variability of fiscal revenue. The last section concludes.

Notas de testemunho e recalque: uma experiência musical dos traumas sociais brasileiros em Chico Buarque e Paulinho da Viola (de meados da década de 1960 a meados da década de 1970)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

O longo caminho: guerreiro ramos e a sociologia da administração antes de a nova ciência das organizações

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Autogenous bone grafts contamination after exposure to the oral cavity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tecnologias de Informação e Comunicação (TICs) e literatura, uma aposta notável

The aim of this study was to develop a qualitative research of bibliographic nature, in order to verify how has been the use of new Information and Communication Technologies (ICTs) and literary reading in early childhood education.. It is believed to be necessary for children, since their early childhood, to, be in contact with various literary works of aesthetic value, which will enable them to understand this particular literary language - and the imagery that comes with it - what can instigate appreciate literature and get the reading habit. The use of ICTs by children beyond the use of games and watching stories on computers, tablets and smartphones, for example, for the production of videos and slides or creating stories, enable new experiences of redesigning and construction of knowledge and culture. The idea for this research came from reading the numerous texts that deal with the need to understand the child as an active subject in the construction of culture and society, rather than as receiving reproductive and cultural orders (CRIANÇAS, 2012). In this sense, in addition to the newsletters Equity For Children: Latin America (CRIANÇAS, 2012), the understanding of childhood and child in the works of Walter O. Kohan (2005; 2006) supports this study. This research proposal was also based on authors and documents that point to the need to promote, since the first stages of Basic Education, the literary reading as a means of enjoyment and emancipation (LAJOLO 2001a; Barthes, 2007; FILIPOUSKY, 2009; BRAZIL, 2010; MACHADO, 2011; VASQUES, 2013), and an education connected to the technological advances of the twenty-first century (BRAZIL, 1997, CHAVES, 1998; DEMO, 2008)

Segregated anatomical input to sub-regions of the rodent superior colliculus associated with approach and defense

The superior colliculus (SC) is responsible for sensorimotor transformations required to direct gaze toward or a way from unexpected, biologically salient events. Significant changes in the external world are signaled to SC through primary multisensory afferents, spatially organized according to a retinotopic topography. For animals, where anunexpected event could indicate the presence of either predator or prey, early decisions to approach or avoid are particularly important. Rodents' ecology dictates predators are most often detected initially as movements in upper visual field (mapped in medial SC), while appetitive stimuli are normally found in lower visual field (mapped in lateral SC). Our purpose was to exploit this functional segregation to reveal neural sites that can bias or modulate initial approach or avoidance responses. Small injections of Fluoro-Gold were made into medial or lateral sub-regions of intermediate and deep layers of SC (SCm/SCl). A remarkable segregation of input to these two functionally defined areas was found. (i) There were structures that projected only to SCm (e.g., specific cortical areas, lateral geniculate and suprageniculate thalamic nuclei, ventromedial and premammillary hypothalamic nuclei, and several brain-stem areas) or SCl (e.g., primary somatosensory cortex representing upper body parts and vibrissae and parvicellular reticular nucleus in the brainstem). (ii) Other structures projected to both SCm and SCl but from topographically segregated populations of neurons (e.g., zona incerta and substantia nigra pars reticulata). (iii) There were a few brainstem areas in which retrogradely labeled neurons were spatially overlapping (e.g., pedunculopontine nucleus and locus coeruleus). These results indicate significantly more structures across the rat neuraxis are in a position to modulate defense responses evoked from SCm, and that neural mechanisms modulating SC-mediated defense or appetitive behavior are almost entirely segregated.

From Amazonia to the Atlantic forest: Molecular phylogeny of Phyzelaphryninae frogs reveals unexpected diversity and a striking biogeographic pattern emphasizing conservation challenges

Documenting the Neotropical amphibian diversity has become a major challenge facing the threat of global climate change and the pace of environmental alteration. Recent molecular phylogenetic studies have revealed that the actual number of species in South American tropical forests is largely underestimated, but also that many lineages are millions of years old. The genera Phyzelaphryne (1 sp.) and Adelophryne (6 spp.), which compose the subfamily Phyzelaphryninae, include poorly documented, secretive, and minute frogs with an unusual distribution pattern that encompasses the biotic disjunction between Amazonia and the Atlantic forest. We generated >5.8 kb sequence data from six markers for all seven nominal species of the subfamily as well as for newly discovered populations in order to (1) test the monophyly of Phyzelaphryninae, Adelophryne and Phyzelaphryne, (2) estimate species diversity within the subfamily, and (3) investigate their historical biogeography and diversification. Phylogenetic reconstruction confirmed the monophyly of each group and revealed deep subdivisions within Adelophryne and Phyzelaphryne, with three major clades in Adelophryne located in northern Amazonia, northern Atlantic forest and southern Atlantic forest. Our results suggest that the actual number of species in Phyzelaphryninae is, at least, twice the currently recognized species diversity, with almost every geographically isolated population representing an anciently divergent candidate species. Such results highlight the challenges for conservation, especially in the northern Atlantic forest where it is still degraded at a fast pace. Molecular dating revealed that Phyzelaphryninae originated in Amazonia and dispersed during early Miocene to the Atlantic forest. The two Atlantic forest clades of Adelophryne started to diversify some 7 Ma minimum, while the northern Amazonian Adelophryne diversified much earlier, some 13 Ma minimum. This striking biogeographic pattern coincides with major events that have shaped the face of the South American continent, as we know it today. (C) 2012 Elsevier Inc. All rights reserved.

I manoscritti miniati dell'Illustratore nella cultura figurativa del secondo quarto del XIV secolo

La tesi è dedicata alla personalità artistica dell’Illustratore, tra i protagonisti della miniatura bolognese degli anni trenta e quaranta del Trecento, così felicemente soprannominato da Roberto Longhi. Dopo un capitolo dedicato alla vicenda critica dell’artista, la tesi affronta il percorso artistico dell’Illustratore nell’ambito della decorazione libraria bolognese del secondo quarto del XIV secolo. Ho trattato le opere attribuite al’Illustratore insieme agli esempi contemporanei della miniatura bolognese, in modo da far emergere il ruolo di questo maestro nelle relazioni con il contesto cittadino. Nella successione cronologica dei manoscritti, emerge un nuovo sconvolgimento caotico che scardina l’ordine spaziale e compositivo delle opere iniziali debitrici del giottismo del Maestro del 1328. Il capitolo si conclude con alcune osservazioni sui rapporti tra il maestro e i suoi aiuti e sul rapporto con Buffalmacco. In questo capitolo sono inoltre presentate due nuove attribuzioni. Gli ultimi due capitoli sono un approfondimento sull’interazione tra il linguaggio figurativo dell’artista e la funzione dell’immagine quale forma di comunicazione visiva in stretta relazione con i testi scritti che accompagnano e sui caratteri della committenza, là dove è possibile definirli. La prima parte del terzo capitolo è dedicata all’illustrazione dei libri legales, mentre nella seconda parte si tratta di un caso particolare, le iniziali istoriate dell’Inferno e del Purgatorio di Dante Alighieri della Biblioteca Riccardiana di Firenze (ms. 1005), per molti aspetti riconducibili all’illustrazione giuridica. La mia intenzione in questo capitolo è di verificare come il caratteristico linguaggio narrativo espressivo e diretto dell’Illustratore abbia risposto alla funzione delle immagini dipinte nei codici giuridici di offrire una struttura materiale alla memorizzazione visiva per via di luoghi e figure dei contenuti di studio del diritto comune. In appendice alla tesi si trova un catalogo dei manoscritti decorati da miniature dell’Illustratore, comprensivo anche di una sezione per le opere di dubbia o erronea attribuzione.

Differential forms on Carnot groups

The main goal of this thesis is to understand and link together some of the early works by Michel Rumin and Pierre Julg. The work is centered around the so-called Rumin complex, which is a construction in subRiemannian geometry. A Carnot manifold is a manifold endowed with a horizontal distribution. If further a metric is given, one gets a subRiemannian manifold. Such data arise in different contexts, such as: - formulation of the second principle of thermodynamics; - optimal control; - propagation of singularities for sums of squares of vector fields; - real hypersurfaces in complex manifolds; - ideal boundaries of rank one symmetric spaces; - asymptotic geometry of nilpotent groups; - modelization of human vision. Differential forms on a Carnot manifold have weights, which produces a filtered complex. In view of applications to nilpotent groups, Rumin has defined a substitute for the de Rham complex, adapted to this filtration. The presence of a filtered complex also suggests the use of the formal machinery of spectral sequences in the study of cohomology. The goal was indeed to understand the link between Rumin's operator and the differentials which appear in the various spectral sequences we have worked with: - the weight spectral sequence; - a special spectral sequence introduced by Julg and called by him Forman's spectral sequence; - Forman's spectral sequence (which turns out to be unrelated to the previous one). We will see that in general Rumin's operator depends on choices. However, in some special cases, it does not because it has an alternative interpretation as a differential in a natural spectral sequence. After defining Carnot groups and analysing their main properties, we will introduce the concept of weights of forms which will produce a splitting on the exterior differential operator d. We shall see how the Rumin complex arises from this splitting and proceed to carry out the complete computations in some key examples. From the third chapter onwards we will focus on Julg's paper, describing his new filtration and its relationship with the weight spectral sequence. We will study the connection between the spectral sequences and Rumin's complex in the n-dimensional Heisenberg group and the 7-dimensional quaternionic Heisenberg group and then generalize the result to Carnot groups using the weight filtration. Finally, we shall explain why Julg required the independence of choices in some special Rumin operators, introducing the Szego map and describing its main properties.