On numbers n with polynomial image coprime with the nth term of a linear recurrence

Let F be an integral linear recurrence, G be an integer-valued polynomial splitting over the rationals, and h be a positive integer. Also, let AF,G,h be the set of all natural numbers n such that gcd(F(n), G(n)) = h. We prove that AF,G,h has a natural density. Moreover, assuming F is non-degenerate and G has no fixed divisors, we show that d(AF,G,1) = 0 if and only if AF,G,1 is finite

Non-Ulrich representation type

We show that a smooth projective non-degenerate arithmetically Cohen-Macaulay subvariety X of P^N infinite Cohen-Macaulay type becomes of finite Cohen-Macaulay type by removing Ulrich bundles if and only if N = 5 and X is a quartic scroll or the Segre product of a line and a plane. In turn, we give a complete and explicit classification of ACM bundles over these varieties

Copper(II), nickel(II) and zinc(II) complexes of hexapeptides containing separate aspartyl and histidyl residues

Copper(II), nickel(II) and zinc(II) complexes of two N-terminally free and C-terminally blocked hexapeptides, NH2-ADAAAH-NH2 and NH2-AADAAH-NH2, containing separate aspartyl and histidyl residues have been studied by potentiometric, UV-Vis, CD and ESR spectroscopic methods. The amino termini were found as the primary anchoring sites of both ligands for the complexation with all three metal ions. The β-carboxylate function of the second or third aspartyl residue enhances the thermodynamic stability of the copper(II) and nickel(II) complexes and shifts the deprotonation of the subsequent amide functions into a more alkaline pH range. In the case of NH2-AADAAH-NH2 the imidazole-N donor of the histidyl residue does not have a significant contribution to the overall stability of the mononuclear complexes. The side chain imidazole, however, can be an independent metal binding site resulting in the formation of dinuclear or even mixed metal complexes. The stabilizing role of the histidyl residue is much more pronounced in the complexes of the NH2-ADAAAH-NH2 peptide. In this case a tridentately (NH2,N-,β-COO-)-coordinated species is formed and its stability is significantly enhanced by the macrochelation of the side chain imidazole. The presence of two anchoring sites (terminal amino and side chain imidazole) in one molecule enhances the stability of the corresponding zinc(II) complexes, too, but the amide nitrogens are not involved in metal binding in this case

Influence of temperature on the equilibria of oxidovanadium(IV) complexes in solution.

The equilibria at different temperatures of VIVOL2complexes were investigated in order to elucidate their interaction with proteins

Mapping and profiling of Albanian diaspora: an economic and social survey in five Italian regions: an overview of the situation in France and Belgium

The aim of the book is to better understand the characteristics of the Albanian diaspora in the three countries, investigating plans and expectations of migrating Albanian citizens with particular interest to a possible direct or indirect contribution and investment. Diaspora and diaspora networks are indeed considered key possible actors to economic and financial contribution to the country of origin, besides the help they grant through family remittances. More particularly, they are recognized for their more trusted and lasting relationships with domestic actors, being able to merge self-economic and solidarity motivation to invest in the country of origin and also be able to mobilize larger networks and forms for capitals and resources. Based on these assumptions, the research had been designed to verify and analyse the extent and the conditions in which could the Albania diaspora abroad be a relevant economic player benefiting the development and investment policies in Albania. The goal is not to make a comparison between Albanian Diaspora communities in Italy, France, and Belgium, but rather to provide an analysis on the driving factor, which has stimulated the migration in these countries. Meanwhile considering that the Albanian Diaspora in Italy is amongst the largest Diaspora abroad, the research is mainly focused on the different patterns of communities in the main five regions of Italy. Moreover, it provides a profiling of Albanian citizens residing in Italy, who have declared an interest in investing in Albania, in order to offer an instrument aimed at strengthening the role of the diaspora for the development of Albania

Unusual binding modes in the copper(II) and palladium(II) complexes of peptides containing both histidyl and cysteinyl residues

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Minerali secondari in ambiente sotterraneo: la miniera dell’Argentiera(Sardegna nord-occidentale)

Una serie di croste e speleotemi che stanno attualmente formandosi nelle gallerie della miniera abbandonata a Pb-Zn-As-Sb dell’Argentiera (Sassari) sono state campionate e sottoposte ad analisi mineralogiche. Oltre 20 fasi cristalline sono state determinate, tra cui molti solfati (barite, copiapite, epsomite, gesso, jarosite, melanterite, metavoltine, e sideronatrite) e carbonati (aragonite, calcite, dypingite, giorgiosite, hydromagnesite e idrozincite). Vari sono inoltre gli ossidi (ematite, akaganeite, e pseudoboleite), idrossidi (goethite, lepidocrocite e todorokite) e silicati (quarzo, illite, feldspato). L’associazione mineralogica più interessante (akaganeite, dypingite, giorgiosite, e hydromagnesite) è stata scoperta su un chiodo che ha fornito il ferro e il magnesio necessario alla loro formazione.A series of mineral crusts and speleothems currently forming in the abandoned tunnels and shafts of the Pb- Zn-As-Sb Argentiera mine (Sassari) have been sampled and analysed. Over 20 crystalline phases have been determined, among which many sulphates (barite, copiapite, epsomite, gypsum, jarosite, melanterite, metavoltine, and sideronatrite) and carbonates (aragonite, calcite, dypingite, giorgiosite, hydromagnesite, and hydrozincite). Also several oxides (hematite, akaganeite, and pseudoboleite), hydroxides (goethite, lepidocrocite, and todorokite) and silicates (quartz, illite, and feldspar) have been found. The most interesting mineral paragenesis (akaganeite, dypingite, giorgiosite, and hydromagnesite) has been discovered on a nail that has given both iron and magnesium necessary to their formation

Potentiometric and spectroscopic studies on the copper(ii) complexes of rat amylin fragments. The anchoring ability of specific non-coordinating side chains.

Copper(ii) complexes of peptides modelling the sequence of the 17-22 residues of rat amylin have been studied by potentiometric, UV-Vis, CD and ESR spectroscopic methods. The peptides were synthesized in N-terminally free forms, NH2-VRSSNN-NH2, NH2-VRSSAA-NH2, NH2-VRAANN-NH2, NH2-VRSS-NH2, NH2-SSNN-NH2, NH2-SSNA-NH2 and NH2-AANN-NH2, providing a possibility for the comparison of the metal binding abilities of the amino terminus and the -SSNN- domain. The amino terminus was the primary ligating site in all cases and the formation of only mononuclear complexes was obtained for the tetrapeptides. The thermodynamic stability of the (NH2, N-, N-) coordinated complexes was, however, enhanced by the asparaginyl moiety in the case of NH2-SSNN-NH2, NH2-SSNA-NH2 and NH2-AANN-NH2. Among the hexapeptides the formation of dinuclear complexes was characteristic for NH2-VRSSNN-NH2 demonstrating the anchoring ability of the -SSNN- (SerSerAsnAsn) domain. The complexes of the heptapeptide NH2-GGHSSNN-NH2 were also studied and the data supported the above mentioned anchoring ability of the -SSNN- site

Interaction of Vanadium(IV) Species with Ubiquitin : A Combined Instrumental and Computational Approach

Altres ajuts: COST Action CM1306The interaction of VIVO2+ ion and five VIVOL2 compounds with potential pharmacological application, where L indicates maltolate (ma), kojate (koj), acetylacetonate (acac), 1,2-dimethyl-3-hydroxy-4(1H)-pyridinonate (dhp), and l-mimosinate (mim), with ubiquitin (Ub) was studied by EPR, ESI-MS, and computational (docking and DFT) methods. The free metal ion VIVO2+ interacts with Glu, Asp, His, Thr, and Leu residues, but the most stable sites (named 1 and 2) involve the coordination of (Glu16, Glu18) and (Glu24, Asp52). In the system with VIVOL2 compounds, the type of binding depends on the vanadium concentration. When the concentration is in the mM range, the binding occurs with cis-VOL2(H2O), L = ma, koj, dhp, and mim, or with VO(acac)2: in the first case, the equatorial coordination of His68, Glu16, Glu18, or Asp21 residues yields species with formula n[VOL2]-Ub where n = 2-3, while with VO(acac)2 only noncovalent surface interactions are revealed. When the concentration of V is on the order of micromolar, themono-chelated species VOL(H2O)2+ with L = ma, koj, acac, dhp, and mim, favored by the hydrolysis, interact with Ub, and adducts with composition n[VOL]-Ub (n = 1-2) are observed with the contemporaneous coordination of (Glu18, Asp21) or (Glu16, Glu18), and (Glu24, Asp52) or (Glu51, Asp52) donors. The results of this work suggest that the combined application of spectroscopic, spectrometric, and computational techniques allow the complete characterization of the ternary systems formed by a V compound and a model protein such as ubiquitin. The same approach can be applied, eventually changing the spectroscopic/spectrometric techniques, to study the interaction of other metal species with other proteins

Potentiometric and spectroscopic studies on the copper(II) complexes of rat amylin fragments. The anchoring ability of specific non-coordinating side chains

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