Prolonged neglect following unilateral disruption of a prefrontal cortical-dorsal striatal system.

We investigated the potential function of the system formed by connections between the medial prefrontal cortex and the dorsomedial striatum in aspects of attentional function in the rat. It has been reported previously that disconnection of the same corticostriatal circuit produced marked deficits in performance of a serial, choice reaction-time task while sparing the acquisition of an appetitive Pavlovian approach behaviour in an autoshaping task (Christakou et al., 2001). Here, we hypothesized that unilateral disruption of the same circuit would lead to hemispatial inattention, contrasting with the global attention deficit following complete disconnection of the system. Combined unilateral lesions of the medial prefrontal cortex (mPFC) and the medial caudate-putamen (mCPu) within the same hemisphere produced a severe and long-lasting contralesional neglect syndrome while sparing the acquisition of autoshaping. These results provide further evidence for the involvement of the medial prefrontal-dorsomedial striatal circuit in aspects of attentional function, as well as insight into the nature of neglect deficits following lesions at different levels within corticostriatal circuitry.

Functional disconnection of a prefrontal cortical-dorsal striatal system disrupts choice reaction time performance: implications for attentional function

This series of experiments investigated the role of a prefrontal cortical-dorsal striatal circuit in attention, using a continuous performance task of sustained and spatially divided visual attention. A unilateral excitotoxic lesion of the medial prefrontal cortex and a contralateral lesion of the medial caudate-putamen were used to "disconnect" the circuit. Control groups of rats with unilateral lesions of either structure were tested in the same task. Behavioral controls included testing the effects of the disconnection lesion on Pavlovian discriminated approach behavior. The disconnection lesion produced a significant reduction in the accuracy of performance in the attentional task but did not impair Pavlovian approach behavior or affect locomotor or motivational variables, providing evidence for the involvement of this medial prefrontal corticostriatal system in aspects of visual attentional function.

Origin and evolution of 3'UTR of flaviviruses: long direct repeats as a basis for the formation of secondary structures and their significance for virus transmission

The 3' untranslated regions (3'UTRs) of flaviviruses are reviewed and analyzed in relation to short sequences conserved as direct repeats (DRs). Previously, alignments of the 3'UTRs have been constructed for three of the four recognized flavivirus groups, namely mosquito-borne, tick-borne, and nonclassified flaviviruses (MBFV, TBFV, and NCFV, respectively). This revealed (1) six long repeat sequences (LRSs) in the 3'UTR and open-reading frame (ORF) of the TBFV, (2) duplication of the 3'UTR of the NCFV by intramolecular recombination, and (3) the possibility of a common origin for all DRs within the MBFV. We have now extended this analysis and review it in the context of all previous published analyses. This has been achieved by constructing a robust alignment between all flaviviruses using the published DRs and secondary RNA structures as "anchors" to reveal additional homologies along the 3'UTR. This approach identified nucleotide regions within the MBFV, NKV (no-known vector viruses), and NCFV 3'UTRs that are homologous to different LRSs in the TBFV 3'UTR and ORF. The analysis revealed that some of the DRs and secondary RNA structures described individually within each flavivirus group share common evolutionary origins. The 3'UTR of flaviviruses, and possibly the ORF, therefore probably evolved through multiple duplication of an RNA domain, homologous to the LRS previously identified only in the TBFV. The short DRs in all virus groups appear to represent the evolutionary remnants of these domains rather than resulting from new duplications. The relevance of these flavivirus DRs to evolution, diversity, 3'UTR enhancer function, and virus transmission is reviewed.

The transition of the Polish real estate market within a Central and Eastern European context

The real estate market in Poland is a relatively immature market, but one that has been experiencing substantial transformation. The development of the market has been encouraged by a number of factors, including changes arising as a result of new legislation and the migration of capital between capital markets. The progress of the real estate sector towards a western style competitive market has taken place within the gradual transformation of the Polish economy into a free market economy. As investment grade property is in relatively short supply in Poland, investors consider opportunities within the wider CEE block. An analysis of the risk-return characteristics of the three largest CEE real estate markets namely, Poland, Hungary and Czech Republic, shows that the returns in these markets have been negatively correlated with the UK. As these economies and markets evolve, and being part of the wider EU trading block, their economic performance will slowly converge and become more synchronized with their western counterparts. However, the catch-up of the CEE markets to western European performance cycles will be protracted and consequently there are likely to be significant ongoing portfolio risk reduction opportunities

Structural transformation of graphite by arc-discharge

The formation of novel structures by the passage of an electric current through graphite is described. These structures apparently consist of hollow three-dimensional graphitic shells bounded by curved and faceted planes, typically made up of two graphene layers. The curved structures were frequently decorated with nano-scale carbon particles, or short nanotubes. In some cases, nanotubes were found to be seamlessly connected to the thin shells, indicating that the formation of the shells and the nanotubes is intimately connected. Small nanotubes or nanoparticles were also sometimes found encapsulated inside the hollow structures, while fullerene-like particles were often seen attached to the outside surfaces. With their high surface areas and structural perfection, the new carbon structures may have applications as anodes of lithium ion batteries or as components of composite materials.

New insights on regulation of LMTK2, a membrane kinase integrating pathways central to neurodegeneration

In a short communication in this issue (Manser et al. 2012), Christopher Miller’s group at the Institute of Psychiatry, King’s College London present an elegant and convincing set of experiments using molecular techniques to show that a brain-enriched membrane-associated protein kinase, lemur tyrosine kinase-2 (LMTK2), is directly phosphorylated by the cyclin-dependent kinase-5/p35 and this event is sufficient for LMTK2 to phosphorylate an abundant protein phosphatase, PP1C. LMTK2 has been little studied to date and, despite its name, is a kinase which phosphorylates serine or threonine residues of protein substrates. The paper adds to the evidence that this enzyme is a potentially important mediator positioned to integrate a number of intracellular signalling pathways relevant to neurodegeneration.

Effects of phthalic acid esters on the liver and thyroid

The effects, over periods from 3 days to 9 months of administration, of diets containing di-2-ethylhexyl phthalate are very similar to those observed in rats administered diets containing hypolipidemic drugs such as clofibrate. Changes occur in a characteristic order commencing with alterations in the distribution of lipid within the liver, quickly followed by proliferation of hepatic peroxisomes and induction of the specialized P-450 isoenzyme(s) catalyzing omega oxidation of fatty acids. There follows a phase of mild liver damage indicated by induction of glucose-6-phosphatase activity and a loss of glycogen, eventually leading to the formation of enlarged lysosomes through autophagy and the accumulation of lipofuscin. Associated changes are found in the kidney and thyroid. The renal changes are limited to the proximal convoluted tubules and are generally similar to changes found in the liver. The effects on the thyroid are more marked. Although the levels of thyroxine in plasma fail to about half normal values, serum triiodothyronine remains close to normal values while the appearance of the thyroid varies, very marked hyperactivity being noted 7 days after commencement of treatment, this is less marked at 14 days, but even after 9 months treatment there is clear cut evidence for hyperactivity with colloid changes which indicate this has persisted for some time. Straight chain analogs of di-2-ethylhexyl phthalate, di-n-hexyl phthalate and di-n-oxtyl phthalate differ entirely in their short-term effects on the liver and kidney but have similar effects on the thyroid. The short-term in vivo hepatic effects of the three phthalate esters can be reproduced in hepatocytes in tissue culture. All three phthalate esters, as well as clofibrate, have early marked effects on the metabolism of fatty acids in isolated hepatocytes. The nature of these changes is such as to increase storage of lipid in the liver. A hypothesis is presented to explain the progress from these initial metabolic effects to the final formation of liver tumors.

Trading death: the implications of annuity replication for the annuity puzzle, arbitrage, speculation and portfolios

Annuities are perceived as being illiquid financial instruments, and this has limited their attractiveness to consumers and their inclusion in financial models. However, short positions in annuities can be replicated using life insurance and debt, permitting long positions in annuities to be offset, or short annuity positions to be created. The implications of this result for the annuity puzzle, arbitrage between the annuity and life insurance markets, and speculation on expected longevity are investigated. It is argued that annuity replication could help reduce the annuity puzzle, improve the price efficiency of annuity markets and promote the inclusion of annuities in household portfolios.

Developing temporary manufacturing facilities for residential building: a case of the modern flying factory

The building industry is often berated for its short comings in meeting up with the demand for the provision of new housing. Addressing the need for new housing stock is a challenge that has led to debates among professional bodies, the construction sector, housing industry and government. The introduction of new manufacturing technologies is often offered as a solution, but the challenges of increasing the amount of off-site construction in residential building are well known and well-rehearsed. The modern flying factory (MFF) is a concept that involves the manufacture of specific components or modules in temporary off- or near- site locations using relatively simple and quick to set up and dismantle technologies and processes. The aim is to produce short batches and hence achieve some of the benefits of off-site manufacture on a much smaller scale than in dedicated factory environments. A case study of a modern flying factory being set up to produce pre-assembled utility cupboards for a large residential development in London is presented, involving participant observation and informal interviews with key actors on the design and operationalising of the process. The case reveals that although there are costs, efficiency and health and safety benefits to using MFF approaches, there are also challenges to overcome over the time required to set up and establish the process for relatively short runs, and in evaluating whether the MFF or traditional site based production is most effective for particular aspects of projects.

Conformational preferences for some 2-substituted N-methoxy-N-methylacetamides through spectroscopic and theoretical studies

The analysis of the IR carbonyl band of the 2-substituted N-methoxy-N-methylacetamides Y-CH(2)C(O)-N(OMe)Me (Y = F1, OMe 2, OPh 3, Cl 4), supported by B3LYP/6-311++G(3df, 3pd) calculations along with the NBO analysis for 1-4, indicated the existence of cis-gauche conformers i.e. (c) and (g) for 1 and 3, (c(1), c(2)) and (g(1), g(2)) for 2, and (c) and (g(1), g(2)) for 4. In the gas phase, the g conformer population prevails over the c one, for 1 and 3, the (c(1) + c(2)) population prevails over the (g(1) + g(2)) one for 2, and the (g(1) + g(2)) conformer population is more abundant than (c) one for 4. In n-hexane solution, the cis conformer is more abundant for 1-3. The occurrence of Fermi resonance in the nu(CO) region, in n-hexane, precludes the estimative of relative populations of the (c, g(1), g(2)) conformers for 4. The SCI-PCM calculations agree with the solvent effect on the nu(CO) band component relative intensities for 1-3. NBO analysis showed that the n(N) -> pi.(CO), orbital interaction is the main factor which stabilizes the gauche (g, g(1), g(2)) conformers for 1-4 into a larger extent relative to the cis (c, c(1), c(2)) ones. The n(y) -> pi(.)(Co,) sigma(C-Y) -> pi.(CO,) pi(CO) -> sigma(C-Y) and 7co orbital interactions still contribute, but into a minor extent for the stabilization of the gauche conformers relative to the cis ones. The existence of some pyramidalization at the nitrogen atom of the Weinreb amides 1-4 is responsible for the occurrence of Y(delta)-(4)center dot center dot center dot O(delta)-(9) and Y(delta)-(4)center dot center dot center dot N(delta)-(7) short contacts in the gauche (g, g(1), g(2)) conformers, which originates strong repulsive Coulombic interactions, acting in opposition to the large orbital stabilization of the gauche conformer with respect to the cis one. Therefore, a delicate balance of the Coulombic and orbital interactions seems to be responsible for the observed stabilization of the gauche (g, g(1), g(2)) and cis (c, c(1), c(2)) conformers, both in the gas phase and in the solution for 1-4. However, the cis conformer predominance, in non polar solvents, for the 2-substituted N-methoxy-N-methyl acetamides 1-3, bearing in a first raw (fluorine and oxygen) atoms, is in the opposite direction to the gauche conformer preference for the corresponding 2-substituted N,N-dialkyl-acetamides. (C) 2010 Elsevier B.V. All rights reserved.

Robustness of stationary tests under long-memory alternatives

This paper investigates the presence of long memory in financiaI time series using four test statistics: V/S, KPSS, KS and modified R/S. There has been a large amount of study on the long memory behavior in economic and financiaI time series. However, there is still no consensus. We argue in this paper that spurious short-term memory may be found due to the incorrect use of data-dependent bandwidth to estimating the longrun variance. We propose a partially adaptive lag truncation procedure that is robust against the presence of long memory under the alternative hypothesis and revisit several economic and financiaI time series using the proposed bandwidth choice. Our results indicate the existence of spurious short memory in real exchange rates when Andrews' formula is employed, but long memory is detected when the proposed lag truncation procedure is used. Using stock market data, we also found short memory in returns and long memory in volatility.

Títulos de dívida corporativa de empresas brasileiras: investir em emissões do mercado interno ou externo?

O objetivo deste trabalho é analisar a diferença de rentabilidade entre emissões de títulos de dívida corporativa de empresas brasileiras nos mercados local e externo. Sob a ótica do investidor interessado em comprar esses títulos, busca-se responder se, protegendo-se contra oscilações de fatores como câmbio e juros e controlando pelo prazo de vencimento, seria mais rentável em média adquirir um título local (debênture) ou externo (bond) de um mesmo emissor. Para isso, analisamos 177 emissões de debêntures e 119 emissões de bonds de 31 companhias não financeiras brasileiras no período entre janeiro de 2004 e abril de 2013. Regressões em painel com efeitos fixos para controlar pelas características de cada emissor verificam que, em média, o título do mercado externo paga de 164 a 197 bps a mais que o do mercado local, e que tal diferença é estatisticamente significante. A diferença deve-se à maior oferta e variedade de títulos de dívida corporativa no mercado externo, à existência de uma demanda cativa de investidores institucionais por debêntures no mercado local e à falta de integração entre os mercados. A participação de pessoas físicas no mercado externo também é identificada como fator relevante, assim como o possível maior custo de estruturação de dívida cobrado por bancos de investimento no mercado doméstico. Dentre as hipóteses formuladas para o motivo dessa diferença de rentabilidade não ser arbitrada, destacam-se o desconhecimento dos investidores e obstáculos operacionais, como custos de transação, impossibilidade de operação no mercado internacional e de venda a descoberto no mercado local. Tal fato causa ainda uma supervalorização das debêntures pela atuação dos investidores mais otimistas. A alta sensibilidade dos investidores institucionais locais à volatilidade dos retornos, também aparece como fator relevante.

Estímulos fiscais em um modelo estrutural para o Brasil

A atual crise econômica internacional mostrou que o combate a hiatos do produto utilizando apenas a política monetária pode não ser suficiente. Neste contexto, questões sobre a eficácia de estímulos fiscais temporários como política anticíclica foram levantadas, e adicionalmente quais estímulos fiscais seriam mais benéficos às economias. Este trabalho desenvolveu um modelo estrutural DSGE com características e calibrações para a economia brasileira. O objetivo era realizar um exercício com choques fiscais expansionistas, de modo a analisar seus multiplicadores fiscais. Os resultados sugerem que o impacto de gastos correntes do governo obteve melhor multiplicador fiscal, tanto no curto quanto no longo prazo, porém teve efeitos acumulativos decrescentes. Por outro lado, o choque de diminuição da alíquota dos impostos sobre consumo obteve baixos multiplicadores fiscais a curto prazo, porém com efeitos crescentes a longo prazo, alcançando multiplicadores de longo prazo similares aos dos gastos do governo.

Capitalismo de estado e inovação: facetas da relação entre estado e iniciativa privada no desenvolvimento nacional

While countries managed to rapidly rise and recover economically, Brazilian social indicators have advanced at short pace in the last decades. Although millions of Brazilians have recently left poverty, Brazil still has a long way to go regarding its socioeconomic development. Circa one fifth of the population is still considered functionally illiterate, basic education has one of the poorest performances in the world, the country has no top-level universities nor produces technology or patents at relevant levels. This paper, at first, analyses how the interaction between government and private agents influenced Brazil’s industrial and economic development, identifying the existence of bonds based on the exchange of private interests that at great extension kept public policies from reaching goals of national interest – the so called crony capitalism. Secondly, the paper verifies how development policies based on the promotion of innovative companies and segments of the industry may positively impact broad socioeconomic development. The paper delves specifically into the cooperation between universities and industry as a development tool. Enterprises and universities, guided by their endogenous interests, may be combined for the structuring of a national innovation system. While universities are fundamentally interested in promoting knowledge accumulation, enterprises are willing to invest financial capital in universities in exchange for the economic exploitation of products developed within the academic environment and direct access to its human capital. Lastly, the paper identifies the legal and cultural barriers and advances of this mechanism in Brazil. It verifies that, notwithstanding the institutional advance promoted by the Law of Innovation to the university-enterprise cooperation in Brazil, the law wasn’t entirely capable of eliminating the legal uncertainty of this relationship and capturing in an efficient way the interests of the agents involved. Recently, federal law n. 12.863/2013 officially offered universities the option of bypassing problems related to public law by regulating support foundations, which conceives greater certainty and simplicity to the cooperation. There are, however, remaining uncertainties regarding the norms to be edited by the executive power, as well as conflicts of interest linked to the property rights over patents resulting from this kind of cooperation. The paper verifies, moreover, the existence of ideological resistance to this tool within universities, in such a way that it is unlikely that those relationships develop in a systematic way throughout the country without further engagement from the government and its executive and legislative bodies.

Citologia: uma proposta formativa na EaD - UFRN a partir de concepções alternativas

Learning difficulties can have a direct influence on the teaching-learning process of students by reducing their school performance. One factor that may contribute to this negative influence on learning refers to the presence of alternative conceptions, which may have different origins in the educational process. It is of paramount importance, for teachers, for example, to identify the concepts and the difficulties of their students in order for that knowledge can be able to contribute significantly to improve the teaching and learning process. From the following considerations, the present study (still in progress) aims to investigate aspects related to the concepts and difficulties of graduating students in relation to the contents of Biology. The participants of the research were undergraduate students in Biological Sciences from UFRN, studying by Distance Learning (Educação a Distância). To develop the survey, questionnaires were developed to identify the contents in Biology that these students have more difficulties as well as an interview to raise misconceptions regarding the content of cytology. Another tool developed was a textbook evaluation form, which was applied in conjunction with a questionnaire in workshops (short courses) in order to identify possible errors and mistakes that could jeopardize the process of teaching and learning, such as the importance that these learners assign to textbooks in the educational process. From the data collected, a booklet on the content of cytology was developed as a product. It is expected that it can be applied in classrooms in order to improve the teaching and learning in references to Biology, to minimize, for example, alternative conceptions than can occur related to the theme