Voting to select projects in participatory budgeting

In participatory budgeting, citizens are invited to vote on different projects. This paper sets out to study the voting stage of participatory budgeting from theoretical and practical perspectives. At theoretical level, the potential objectives of voting procedures are examined. From the practical point of view it should be easy to select projects, even when the number of projects is large. This paper proposes three algorithms which are theoretically justified and can be easily applied. Participatory budgeting in the town of Portugalete (Spain) provides a test for them. The results obtained with 2018 voting data suggest that the algorithm that includes the costs of the projects at the selection stage performs better than the others. KEYWORDS: decision processes; participatory budgeting; collective decision-making; cost-benefit analysis.     

Characterisation of Ba2In2 − x Sn x O5 + x/2 oxide ion conductors

The Ba₂In_2 − x Sn _x O_5 + x/2 solid solution was confirmed up to x = 1 by solid-state reaction. X-ray diffraction at room and at elevated temperatures, Raman scattering and impedance spectroscopy were used to characterise the samples. The structure refinement of the composition x = 0.1 from neutron diffraction data reveals that tin is preferentially located in the tetrahedral layers of the brownmillerite. Paper presented at the 11th EuroConference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15, 2007     

Parallel synthesis of a lipopeptide library by hydrazone-based chemical ligation

alpha-Melanocyte-stimulating hormone (alpha-MSH) is an endogeneous linear tridecapeptide with potential application for the modulation of skin tanning. To evaluate the interest of introducing a lipid moiety onto this peptide, we developed an efficient chemoselective parallel method to prepare a large series of analogues of alpha-melanocortin with high purity, varying the nature or the relative position of the lipid moiety. Two sets of building blocks containing lipidic alpha-oxo-aldehydes or alpha-hydrazinoacetyl peptides were combined to obtain a 102-membered library of amphiphilic alpha-MSH analogues. This library was pharmacologically tested at 1 x 10(-7) M for the ability to induce AMPc production in M4Be melanoma cell line after stimulation of the human melanocortin MC1 receptor. Among theses lipopeptides, 84 compounds exhibited an AMPc induction higher than Melitane, a patented alpha-MSH agonist. These results provide strong evidence of the interest of introduction of a lipid tail for the pharmacomodulation of bioactive peptides.     

Fourier and barycentric formulae for equidistant Hermite trigonometric interpolation

We consider the Hermite trigonometric interpolation problem of order 1 for equidistant nodes, i.e., the problem of finding a trigonometric polynomial t that interpolates the values of a function and of its derivative at equidistant points. We give a formula for the Fourier coefficients of t in terms of those of the two classical trigonometric polynomials interpolating the values and those of the derivative separately. This formula yields the coefficients with a single FFT. It also gives an aliasing formula for the error in the coefficients which, on its turn, yields error bounds and convergence results for differentiable as well as analytic functions. We then consider the Lagrangian formula and eliminate the unstable factor by switching to the barycentric formula. We also give simplified formulae for even and odd functions, as well as consequent formulae for Hermite interpolation between Chebyshev points.     

Micro Raman spectroscopy used for the study of corrosion products on copper alloys: study of the chemical composition of artificial patinas used for restoration purposes

Studying the atmospheric corrosion of copper alloy artifacts is important to acquire a better knowledge about the condition of the object and its possible conservation and restoration. The nature of the formed product, e.g. sulfate, carbonate or chloride, depends on factors such as the amount of polluting elements or humidity but may also depend on the nature of the underlying aesthetic patina, applied by the artist. The composition of the patination solution and the method of patination will both influence the nature of this aesthetic patina, i.e. its chemical composition and morphology. However, although a lot of patination recipes exist, little is known about these patinas as far as composition, structure and ageing is concerned. Therefore, a combination of several surface analytical techniques is required for the complete characterization of patina layers. In this paper, Raman spectroscopy is used to study the characteristics of several patinas obtained on copper following different traditional recipes.     

Recycling of homogeneous hydrogenation catalysts by dialysis coupled catalysis

Although transition-metal complexes are very attractive as homogeneous catalysts in fine chemistry, their high prices often limit their applications. A means to recycle those catalysts would solve this problem and would simultaneously facilitate the downstream purification of the product. This is now realized in a new concept in which homogeneous catalysis is coupled to dialysis. The advantages of homogeneous catalysis (off-the-shelf catalysts, high activities and selectivities) are thus combined with those of heterogeneous catalysis (easy catalyst separation from product solution, reuse of catalyst, and possibility for continuous operation). Since the heart of the process is the membrane, self-prepared membranes were preferred as they allow a better control and understanding of the separation characteristics. Rhodamine B was used as a probe molecule to define the working conditions of the membrane. The concept is proven to work for two relevant chiral reactions: a hydrogenation with Ru-BINAP and a hydrogen transfer reaction with Ru-TsDPEN [BINAP=(1,1'-binaphthalene)-2,2'-diylbis(diphenylphosphine); TsDPEN= tosyl-N,N'-diphenyl-1,2-ethanediamine].     

Quantification of the 35S promoter in DNA extracts from genetically modified organisms using real-time polymerase chain reaction and specificity assessment on various genetically modified organisms, part I: operating procedure

A highly sensitive quantitative real-time assay targeted on the 35S promoter of a commercial genetically modified organism (GMO) was characterized (sF/sR primers) and developed for an ABI Prism 7700 Sequence Detection System and TaqMan chemistry. The specificity assessment and performance criteria of sF/sR assay were compared to other P35S-targeted published assays. sF/sR primers amplified a 79 base pair DNA sequence located in a part of P35S that is highly conserved among many caulimovirus strains, i.e., this consensus part of CaMV P35S is likely to be present in many GM events. According to the experimental conditions, the absolute limit of detection for Bt176 corn was estimated between 0.2 and 2 copies of equivalent genome (CEG). The limit of quantification was reached below 0.1% Bt176 content. A Cauliflower Mosaic Virus control (CaMV) qualitative assay targeted on the ORF III of the viral genome was also used as a control (primers 3F/3R) to assess the presence of CaMV in plant-derived products. The specificity of this test was assessed on various CaMV strains, including the Figwort Mosaic Virus (FMV) and solanaceous CaMV strains. Considering the performance of sF/sR quantification test, the highly conserved sequence, and the small size of the amplicon, this assay was tested in a collaborative study in order to be proposed as an international standard.     

Thermodynamic origin of the chiral recognition of tryptophan on teicoplanin and teicoplanin aglycone stationary phases

The D-, L-tryptophan binding and the chiral recognition properties of the teicoplanin and teicoplanin aglycone (TAG) chiral stationary phase (CSPs) were compared at various column temperatures. The solute adsorption isotherms (bi-Langmuir model) were determined for both the two CSPs using the perturbation method. It was demonstrated that the sugar units were involved in the reduction of the apparent enantioselectivity through two phenomena: (i) the inhibition of some enantioselective contacts with low-affinity binding regions of the aglycone and (ii) a decrease in the stereoselective properties of the aglycone high-affinity binding pocket. The phenomenon (ii) was governed by both a decrease in the ratio of the enantiomer adsorption constant and a strong reduction of the site accessibility for D- and L-tryptophan. In addition, a temperature effect study was performed to investigate the chiral recognition mechanism at the aglycone high-affinity pocket. An enthalpy-entropy compensation analysis derived from the Grunwald model as well as the comparison with the literature data demonstrated that the enantioselective binding mode was dependent on an interface dehydration process. The change in the enantioselective process observed between the TAG and teicoplanin CSP was characterized by a difference of ca. 2-3 ordered water molecules released from the species interface.