Foreign reserves’ strategic asset allocation

Despite foreign reserves’ strategic asset allocation relies mainly on Modern Portfolio Theory (MPT), the unique characteristics of central banks obliges them to articulate and reconcile typical optimization procedures with reserves’ management objectives such as providing confidence regarding the ability to meet the country’s external commitments. Moreover, further involvedness come from broad economic factors as diverse as the openness of capital and current accounts, external debt’s maturity and currency composition, and exchange rate regime. Therefore, in order to alleviate the divergence from theory and practice regarding foreign reserves’ strategic asset allocation, this paper describes the methodologies and procedures developed and employed by the Foreign Reserves Department of Banco de la República. The mainstay of the paper is a long-term-dependence-adjusted and non-loss-constrained version of the Black-Litterman model for obtaining the efficient frontier from a set of investments complying with safety, liquidity and return criteria, where the choice of the portfolio which maximizes utility makes use of an estimation of the Board of Directors’ risk aversion. Results exhibit the effects of the unique nature of foreign reserves management for emerging markets. Typical features of foreign reserves management by central banks, such as non-loss restrictions due to capital preservation objectives, result in increased complexity in the optimization process and in asset allocations significantly distant from standard MPT’s optimality.Foreign reserves, Black-Litterman, strategic asset allocation. Classification JEL: G11, E58, C11, C61.

Too-connected-to-fail Institutions and Payments System’s Stability: Assessing Challenges for Financial Authorities

The most recent episode of market turmoil exposed the limitations resulting from the traditional focus on too-big-to-fail institutions within an increasingly systemic-crisis-prone financial system, and encouraged the appearance of the too-connected-to-fail (TCTF) concept. The TCTF concept conveniently broadens the base of potential destabilizing institutions beyond the traditional banking-focused approach to systemic risk, but requires methodologies capable of coping with complex, cross-dependent, context-dependent and non-linear systems. After comprehensively introducing the rise of the TCTF concept, this paper presents a robust, parsimonious and powerful approach to identifying and assessing systemic risk within payments systems, and proposes some analytical routes for assessing financial authorities’ challenges. Banco de la Republica’s approach is based on a convenient mixture of network topology basics for identifying central institutions, and payments systems simulation techniques for quantifying the potential consequences of central institutions failing within Colombian large-value payments systems. Unlike econometrics or network topology alone, results consist of a rich set of quantitative outcomes that capture the complexity, cross-dependency, context-dependency and non-linearity of payments systems, but conveniently disaggregated and dollar-denominated. These outcomes and the proposed analysis provide practical information for enhanced policy and decision-making, where the ability to measure each institution’s contribution to systemic risk may assist financial authorities in their task to achieve payments system’s stability.Payments systems, too-connected-to-fail, too-big-to-fail, systemic risk, network topology, simulation, central bank liquidity. Classification JEL:E58, E44, C63, G21, D85.

Does the Use of Foreign Currency Derivatives Affect Colombian Firms’ Market Value?

Classic financial theory relies on the absolute perfection of capital markets, which results in one of the milestones of theoretical corporate finance: the firm’s value is invariant to the choice of capital structure. As an extension to the aforementioned proposition by Modigliani and Miller (1958), corporate risk management is also futile. Nevertheless, it is clear that capital markets do not work with absolute perfection. There exist frictions which make risk management decisions essential for the firm’s value. Moreover, derivatives’ market vast importance is a good proxy of the relevance of hedging decisions for corporate finance. There is a remarkable volume of literature which tests the effects of risk management and hedging decisions for the value of the firm, mainly for the US corporate market. However, there is little effort on this subject for markets which work even farther from absolute perfection. This document undertakes such task for the Colombian market. Focused on non-financial firms and the local’s most liquid derivatives market, we find that for a panel of eight large Colombian corporations, the growth rate of Tobin´s Q depends significantly on firm´s size and hedging. Our results suggests that, after controlling for relevant financial variables such as firm´s profitability and leverage, and other variables such as firm´s age, an increase in hedging leads to a higher growth in the firm´s value.Modigliani-Miller, risk management, hedging, firm value, emerging market, Tobin´s Q. Classification JEL: G32, G30, L25.

ICE: Enabling Non-Experts to Build Models Interactively for Large-Scale Lopsided Problems

Quick interaction between a human teacher and a learning machine presents numerous benefits and challenges when working with web-scale data. The human teacher guides the machine towards accomplishing the task of interest. The learning machine leverages big data to find examples that maximize the training value of its interaction with the teacher. When the teacher is restricted to labeling examples selected by the machine, this problem is an instance of active learning. When the teacher can provide additional information to the machine (e.g., suggestions on what examples or predictive features should be used) as the learning task progresses, then the problem becomes one of interactive learning. To accommodate the two-way communication channel needed for efficient interactive learning, the teacher and the machine need an environment that supports an interaction language. The machine can access, process, and summarize more examples than the teacher can see in a lifetime. Based on the machine's output, the teacher can revise the definition of the task or make it more precise. Both the teacher and the machine continuously learn and benefit from the interaction. We have built a platform to (1) produce valuable and deployable models and (2) support research on both the machine learning and user interface challenges of the interactive learning problem. The platform relies on a dedicated, low-latency, distributed, in-memory architecture that allows us to construct web-scale learning machines with quick interaction speed. The purpose of this paper is to describe this architecture and demonstrate how it supports our research efforts. Preliminary results are presented as illustrations of the architecture but are not the primary focus of the paper

Uma família de raça negra com fibrose cística.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Pediatria, Curso de Medicina, Florianópolis, 198

IAA : Información y actualidad astronómica (15)

Sumario : INVESTIGACIÓN. Aerosoles atmosféricos: sus efectos en el clima de las atmósferas del sistema solar.-- El gas molecular en las galaxias.-- VENTANA ABIERTA. Todo un privilegio.-- CHARLAS CON...Vicent Martínez.-- ACTUALIDAD CIENTÍFICA. Un sistema planetario joven en torno a Beta Pictores.-- Una nueva visita a Canis Major .-- ACTIVIDADES IAA.-- AGENDA.Esta revista se publica con la ayuda de la Accion Especial DIF 2001-4284-E del Programa Nacional de Difusión de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.N

A importância do exercício físico para crianças portadoras do transtorno do espectro autista

O Transtorno do Espectro Autista (TEA) caracteriza-se por alteração no neurodesenvolvimento, em que o paciente possui dificuldade de estabelecer relacionamentos sociais e emocionais, apresenta padrões de repetição no comportamento e atitudes estereotipadas. Crianças com TEA também têm limites na coordenação motora, dificultando a prática de exercícios físicos. Sabe-se que os exercícios desenvolvem o sistema cardiorrespiratório, a habilidade motora e a força muscular, além de reduzir o índice de massa corporal. Para crianças portadoras de TEA, eles também diminuem comportamentos estereotipados, ajudam nos relacionamentos sociais e emocionais e desenvolvem a cognição, levando à melhoria da qualidade de vida. Descrever a importância da prática de exercício físico para o bom prognóstico dos pacientes da faixa etária infantil portadores do Transtorno do Espectro Autista. Trata-se de uma revisão integrativa da literatura, descritiva, na qual foram selecionados 6 artigos científicos obtidos nas plataformas Scielo e PubMed e com a utilização dos Descritores em Ciência da Saúde (DeCS): “Autism”, “Impact” e “Physical activity”. Foram utilizados apenas artigos originais e de revisão, de periódicos nacionais e internacionais, escritos nas línguas inglesas e portuguesas e publicados no período de 2015 a 2020. A falta de habilidade motora em pacientes com TEA caracteriza-se por problemas cognitivos, de equilíbrio e de coordenação, levando à fraqueza postural, dificuldade de movimento e força. Foi observado, na prática de exercícios físicos, que a criança com TEA pode apresentar dificuldades cognitivas, como seguir regras, acompanhar jogos, interpretar e responder a comunicação usadas pela equipe. Assim, essas situações podem predispor um estilo de vida sedentário à criança. A prática regular de exercícios físicos, entretanto, contribuem para diversas melhorias funcionais e comportamentais, ajudando o paciente a desenvolver habilidades sociais, visto que estimulam a formação de novos relacionamentos e o trabalho em equipe. Referente ao tipo de exercício físico, ainda não há estudos conclusivos para notar se há maior vantagem em exercícios aeróbicos ou de resistência para mudanças expressivas na TEA. No entanto, atividades aquáticas e esportes que envolvam trabalho em equipe são os mais utilizados, pois é importante trabalhar o aspecto social dos indivíduos e, assim, ajudá-los nos seus relacionamentos interpessoais. O exercício físico é capaz de diminuir o IMC, melhorar as habilidades sociais e motoras, a atenção, a memória, e, ainda, diminuir os comportamentos clássicos do TEA. Após o início dessa prática, observa-se uma grande melhora na coordenação manual, força, agilidade e coordenação corporal, diminuindo o comprometimento corporal como barreira para engajamento social

Opposing roles for Hoxa2 and Hoxb2 in hindbrain oligodendrocyte patterning

Oligodendrocytes are the myelin-forming cells of the vertebrate CNS. Little is known about the molecular control of region-specific oligodendrocyte development. Here, we show that oligodendrogenesis in the mouse rostral hindbrain, which is organized in a metameric series of rhombomere-derived (rd) territories, follows a rhombomere-specific pattern, with extensive production of oligodendrocytes in the pontine territory (r4d) and delayed and reduced oligodendrocyte production in the prepontine region (r2d, r3d). We demonstrate that segmental organization of oligodendrocytes is controlled by Hoxgenes, namely Hoxa2 and Hoxb2. Specifically, Hoxa2 loss of function induced a dorsoventral enlargement of the Olig2/Nkx2.2-expressing oligodendrocyte progenitor domain, whereas conditional Hoxa2 overexpression in the Olig2(+) domain inhibited oligodendrogenesis throughout the brain. In contrast, Hoxb2 deletion resulted in a reduction of the pontine oligodendrogenic domain. Compound Hoxa2(-/-)/Hoxb2(-/-) mutant mice displayed the phenotype of Hoxb2(-/-) mutants in territories coexpressing Hoxa2 and Hoxb2 (rd3, rd4), indicating that Hoxb2 antagonizes Hoxa2 during rostral hindbrain oligodendrogenesis. This study provides the first in vivo evidence that Hox genes determine oligodendrocyte regional identity in the mammalian brain

Com o diabo no corpo: os terríveis papagaios do Brasil colônia

Desde a Antiguidade, papagaios, periquitos e afins (Psittacidae) fascinaram os europeus por seu vivo colorido e uma notável capacidade de interação com seres humanos. A descoberta do Novo Mundo nada faria além de acrescentar novos elementos ao tráfico de animais exóticos há muito estabelecido pelos europeus com a África e o Oriente. Sem possuir grandes mamíferos, a América tropical participaria desse comércio com o que tinha de mais atrativo, essencialmente felinos, primatas e aves - em particular os papagaios, os quais eram embarcados em bom número. Contudo, a julgar pelos documentos do Brasil colônia, esses voláteis podiam inspirar muito pouca simpatia, pois nenhum outro animal - exceto as formigas - foi tantas vezes mencionado como praga para a agricultura. Além disso, alguns psitácidas mostravam-se tão loquazes que inspiravam a séria desconfiança de serem animais demoníacos ou possessos, pois só três classes de entidades - anjos, homens e demônios - possuíam o dom da palavra. Nos dias de hoje, vários representantes dos Psittacidae ainda constituem uma ameaça para a agricultura, enquanto os indivíduos muito faladores continuam despertando a suspeita de estarem possuídos pelo demônio. Transcendendo a mera curiosidade, essa crença exemplifica o quão intrincadas podem ser as relações do homem com o chamado “mundo natural”, revelando um universo mais amplo e multifacetado do que se poderia supor a princípio. Nesse sentido, a existência de aves capazes de falar torna essa relação ainda mais complexa e evidencia que as dificuldades de estabelecer o limite entre o animal e o humano se estendem além dos primatas e envolvem as mais inusitadas espécies zoológicas.Since ancient times, parrots and their allies (Psittacidae) have fascinated Europeans by their striking colors and notable ability to interact with human beings. The discovery of the New World added new species to the international exotic animal trade, which for many centuries had brought beasts to Europe from Africa and the Orient. Lacking large mammals, tropical America participated in this trade with its most appealing species, essentially felines, primates and birds - especially parrots - which were shipped in large numbers. It should be noted, however, that at times these birds were not well liked. In fact, according to documents from colonial Brazil, only the ants rank higher than parrots as the animals most often mentioned as agricultural pests. On the other hand, some of these birds were so chatty that people suspected them to be demonic or possessed animals, since only three classes of beings - angels, men and demons - have the ability to speak. Nowadays, several Psittacidae still constitute a threat to agriculture, and the suspicion that extremely talkative birds were demon possessed has also survived. More than a joke or a mere curiosity, this belief exemplifies how intricate man’s relationships with the “natural world” may be. In this sense, the existence of birds that are able to speak adds a further twist to these relationships, demonstrating that the problem of establishing a boundary between the animal and the human does not only involve primates, but also includes some unusual zoological species