Economic Clubs and European Commitment. Evidence from the International Business Cycles

This paper examines the emergence of economic clubs and its coherence with the european commitments. to this end, it analyses business cycle comovements in six industrialised economies, which are pooled into several clusters. results lead to conclude that an english-speaking club (canada, uk, us) is emerging in the last decades, whereas explicit and formal commitments seem to have had a relatively weaker power in determining euro-zone business cycles comovements. while the broad conclusions are consistent with the existing literature the proposed empirical framework is not based on correlations testing, under very few assumptions, the relative cyclical association via the marginal homogeneity in 2x2 contingency tables.business cycles, synchronization, turning points, nonparametric test

A quantitative view on policymakers’ goal, institutions and tax evasion

We develop a general theoretical model to compare two different policymakers both facing tax evasion. Policymakers differs in that they aim to maximize either the fiscal revenues (T) as in a social-democracy as, e.g., Sweden, or the GDP as in a capitalistic country as, e.g., the USA. Both Bureaus can manoeuvre the tax rate and the share of tax receipts spent to fight the tax evasion rather than to increase the public capital. Our model merges the indications of two distinct, and sometimes conflicting, approaches to the analysis of tax evasion in that reconciling them. We also find that the feedbacks between the private and public sector are linked to some Laffer-type relationships usually unexplored by the existing literature. As compared to capitalistic systems, then, our results show that social-democracies end up imposing higher tax rates and, possibly, more pervasive regulations. Consequently, they are likely to suffer from larger tax-evasion-to-GDP ratios. This notwithstanding,social-democracies spend relatively more to contrast tax dodgers. On the other hand, T-maximizing governments have better institutional settings and greater employment rates. Whichever the preferred target, however, no policymaker is able to erase totally the tax evasion, which may explain why this latter is so pervasive and persistent even among the richest countries

Bayesian estimation and entropy for economic dynamic stochastic models: An exploration of overconsumption

This paper examines psycho-induced overconsumption in a dynamic stochastic context. As emphasized by well-established psychological results, these psycho-distortions derive from a decision making based on simple rules-of-thumb, not on analytically sounded optimizations. To our end, we therefore compare two New Keynesian models. The first is populated by optimizing Muth-rational agents and acts as the normative benchmark. The other is a “psycho-perturbed” version of the benchmark that allows for the potential presence of overoptimism and, hence, of overconsumption. The parameters of these models are estimated through a Bayesian-type procedure, and performances are evaluated by employing an entropy measure. Such methodologies are particularly appropriate here since they take in full consideration the complexity generated by the randomness of the considered systems. In particular, they let to derive a not negligible information on the size and on the cyclical properties of the biases. In line with cognitive psychology suggestions our evidence shows that the overoptimism/overconsumption is: widespread—it is detected in nation-wide data; persistent—it emerges in full-sample estimations; it moves according to the expected cyclical behavior—larger in booms, and it disappears in crises. Moreover, by taking into account the effect of these psycho-biases, the model fits actual data better than the benchmark. All considered, then, enhancing the existing literature our findings: i) sustain the importance of inserting psychological distortions in macroeconomic models and ii) underline that system dynamics and psycho biases have statistically significant and economically important connections

Structure of a lectin with antitumoral properties in king bolete (Boletus edulis) mushrooms.

A novel lectin has been isolated from the fruiting bodies of the common edible mushroom Boletus edulis (king bolete, penny bun, porcino or cep) by affinity chromatography on a chitin column. We propose for the lectin the name BEL (B. edulis lectin). BEL inhibits selectively the proliferation of several malignant cell lines and binds the neoplastic cell-specific T-antigen disaccharide, Galβ1-3GalNAc. The lectin was structurally characterized: the molecule is a homotetramer and the 142-amino acid sequence of the chains was determined. The protein belongs to the saline-soluble family of mushroom fruiting body-specific lectins. BEL was also crystallized and its three-dimensional structure was determined by X-ray diffraction to 1.15 Å resolution. The structure is similar to that of Agaricus bisporus lectin. Using the appropriate co-crystals, the interactions of BEL with specific mono- and disaccharides were also studied by X-ray diffraction. The six structures of carbohydrate complexes reported here provide details of the interactions of the ligands with the lectin and shed light on the selectivity of the two distinct binding sites present in each protomer

Genetic analysis for sooty mold resistance and heart of palm yield in Archontophoenix.

Palmeiras do gênero Archontophoenix, utilizadas tanto como ornamentais quanto produtoras de palmito de qualidade, são susceptíveis à fumagina, doença associada à infestação por pulgões, que afeta a fotossíntese, o crescimento e a aparência das plantas. Foram avaliados a campo a resistência à fumagina conjuntamente com três caracteres associados ao crescimento em 24 famílias de meios-irmãos, 28 meses após o plantio, a fim de identificar a variabilidade genética para os caracteres resistência à fumagina, altura, diâmetro e número de folhas; estimar as correlações genotípicas e fenotípicas envolvendo esses quatro caracteres; e aplicar a estratégia de seleção usando o índice multiefeitos. Houve diferenças entre as famílias para os caracteres avaliados, sugerindo a possibilidade de seleção. O baixo coeficiente de variação observado para resistência à fumagina (9,48%) indica que o método de avaliação adotado, baseado em escala de notas após observação visual, foi eficiente e prático para comparar níveis de infestação do complexo fungo+pulgão em palmeiras do gênero Archontophoenix. As estimativas da herdabilidade no sentido restrito foram baixas a médias para os caracteres relacionados ao crescimento (0,10, 0,26 e 0,26 para número de folhas, diâmetro e altura da planta, respectivamente) e muito altas (0,91) para resistência à fumagina. Correlação genética positiva foi observada entre resistência à fumagina e altura da planta, indicando que a eliminação de plantas muito susceptíveis pode ser feita sem interferência na seleção indireta para produção de palmito. A estratégia de seleção pelo índice multiefeitos (com ganhos genéticos esperados variando de 6,23 a 11,83%) mostrou-se adequada para melhorar simultaneamente caracteres relacionados ao crescimento e à produção de palmito

Structural characterization and interaction studies of humanlipocalin-type prostaglandin D synthase (L-PGDS)

Lipocalin-type prostaglandin D synthase (L-PGDS) catalyzes the isomerisation of the 9,11-endoperoxide group of PGH2 (Prostaglandin H2) to produce PGD2 (Prostaglandin D2) with 9-hydroxy and 11-keto groups in the presence of sulphydryl compounds. PGH2 is a common precursor of all prostanoids, which include thromboxanes, prostacyclins and prostaglandins. PGD2 is synthesized in both the central and peripheral nervous system and it is involved in many regulatory events. L-PGDS, the first member of the important lipocalin family to be recognized as an enzyme, is also able to bind and transport small hydrophobic molecules and was formerly known as \u3b2-trace protein, the second most abundant protein in human cerebro-spinal fluid. L-PGDS is also detected in brain, testis and prostate, endothelial cells, placenta and heart tissue and even in macrophages infiltrated in atherosclerotic plaques. In these tissues it participates in many physiological activities as well as in the response to diseases. Currently the main structural and biochemical studies, present in the literature, concern recombinant rat and mouse L-PGDS. In this work we use recombinant human L-PGDS in order to solve its three-dimensional structure by X-ray diffraction and test its affinity for several ligands using Surface Plasmon Resonance (SPR). Wild type human L-PGDS and three mutants (C65A; C65A-K59A; C89/186A) were expressed using E. coli cell strains and subsequently purified by a chitin affinity column, size exclusion and hydrophobic interaction chromatography. Large and highly ordered crystals were used to collect X-ray diffraction data using either a rotating-anode generator or a synchrotron source. The multiple isomorphous replacement method was used to solve the phase problem. In the electron density maps an unidentified density was observed apparently interacting with lysine 59 inside the L-PGDS-C65A cavity; the foreign molecule is probably PEG, an additive present in the crystallization liquors. This hypothesis is supported by the fact that the L-PGDS-C65A/K59A crystals, which grow without PEG, show a completely free protein cavity. A seeding experiment of L-PGDS-C65A/K59A crystal, grown in L-PGDS-C65A crystallization conditions, partially confirmed this hypothesis since the foreign molecule was present in the L-PGDS-C65A/K59A cavity. Another crystal form was obtained by mixing L-PGDS-C65A/K59A with the amyloid \u3b2 peptide (1-40). Although the amyloid \u3b2 peptide is not visible in the maps, the packing of the protein molecules has changed in the presence of the peptide suggesting interaction of the two molecules. Wild type L-PGDS small crystals were recently obtained and will be tested as soon beam time at a synchrotron source becomes available. SPR experiments are also in progress and will be used to verify interaction of L-PGDS with PEG, the amyloid \u3b2 peptide and other ligands and to determine their binding constants

Structural studies of POL (Pleurotus ostreatus Lectin), a fungal lectin of medical interest

Lectins are proteins widely diffuse in nature that interact non-covalently with carbohydrates [1]. Of all the mushroom proteins, lectins are probably the most extensively investigated because it has been observed that they can exhibit antitumour activity on human cancer cells [2]. Among them, a lectin from the fruiting bodies of the edible oyster mushroom Pleurotus ostreatus was isolated since it appears to be able to inhibit the growth of human neoplastic cells [3]. It was named POL, Pleurotus ostreatus lectin and in our laboratory it is purified using two chromatographic steps: a hog gastric mucin column followed by a Sephacryl S-100 gel filtration column. Two alternative ways of elution from the affinity column (with lactose 0.2 M and with EDTA 5 mM) give the same yield (1-1.5 mg) of protein starting with 500 g of mushrooms. Crystals of 0,1-0,3 mm can be grown in two crystallization conditions: 1) 0.1 M Na Hepes pH 7.5 in the presence of 0.8 M potassium/sodium tartrate tetrahydrate and 2) 1.6 M Ammonium sulphate, 0.1 MES pH 6.5 and 10% v/v Dioxane. We have collected X-ray diffraction data at various beamlines of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The structure was solved by Single Isomorphous Replacement (SIR) with anomalous dispersion. The model was built with the program Coot and refinement was carried out with data collected from apo crystals at 2.05 \uc5 using RefMac 5. The unknown preliminary amino acid sequence of the polypeptide chain was obtained from the electron density maps. The asymmetric unit contains one monomer with two domains of 22 \u3b2-strand only: 10 forming the domain near the N-terminus and 12 the C-terminus nearer, with a conformation that resembles the \u3b2-barrel fold. \u3b2-sheets are radially arranged around a central tunnel packing face-to-face. Since there seems to be an enzymatic activity associated to POL, the purified lectin was routinely checked with DLS experiments to ensure that the eventual enzymatic activity was only due to the lectin and not to other contaminants [4]. The presence of a single peak confirmed the purity of the sample and so it was decided to perform enzymatic assays with four nitrophenol derivatives. The most reactive substrate for POL was 4-nitrophenyl-\u3b2-D-glucopyranoside with a Vmax=87.21 nmol sec-1 mg-1, kcat=43s-1 and Km=240 \ub5M. Since in the POL electron density maps there was a region too big for water fitting the presence of a metal cofactor was suspected. Experiments with the spectrofluorimeter, analyzing fluorescence protein quenching upon the addition of a metal, were carried out and confirmed the presence of Calcium bound to the lectin. As POL density maps did not reveal any density regions that could be ascribed to a carbohydrate, it will be necessary to crystallize the lectin with specific inhibitors bound at the active site (for example nojirimycin). In addition, POL was also tested on human pancreatic cancer cells (MiaPaCa-2) and its therapeutic effect was evident. The antitumoral activity of POL might be exploited to direct PLGA, poly(lactic-co-glycolic acid) nanoparticles, to different melanoma cell lines, and also to prepare POL-filled nanoparticles emulsions or patches applicable on melanomas. For this purpose, since the total yield of purified POL is very low, attempts of heterologous expression in Pichia pastoris and E. coli ,with the protein sequence optimized for the expression in this bacterial system, are still in progress

Structural characterization and interaction studies of human lipocalin-type prostaglandin D synthase (L-PGDS)

Structural characterization and interaction studies of human lipocalin-type prostaglandin D synthase (L-PGDS