Steric effects on uranyl complexation: synthetic, structural, and theoretical studies of carbamoyl pyrazole compounds of the uranyl(VI) ion

New bifunctional pyrazole based ligands of the type [C3HR2N2CONR'] (where R = H or CH3; R' = CH3, C2H5, or (C3H7)-C-i) were prepared and characterized. The coordination chemistry of these ligands with uranyl nitrate and uranyl bis(dibenzoyl methanate) was studied with infrared (IR), H-1 NMR, electrospray-mass spectrometry (ES-MS), elemental analysis, and single crystal X-ray diffraction methods. The structure of compound [UO2(NO3)(2)(C3H3N2CON{C2H5}(2))] (2) shows that the uranium(VI) ion is surrounded by one nitrogen atom and seven oxygen atoms in a hexagonal bipyramidal geometry with the ligand acting as a bidentate chelating ligand and bonds through both the carbamoyl oxygen and pyrazolyl nitrogen atoms. In the structure of [UO2(NO3)(2)(H2O)(2)(C5H7N2CON {C2H5}(2))(2)], (5) the pyrazole figand acts as a second sphere ligand and hydrogen bonds to the water molecules through carbamoyl oxygen and pyrazolyl nitrogen atoms. The structure of [UO2(DBM)(2)C3H3N2CON{C2H5}(2)] (8) (where DBM = C6H5COCHCOC6H5) shows that the pyrazole ligand acts as a monodentate ligand and bonds through the carbamoyl oxygen to the uranyl group. The ES-MS spectra of 2 and 8 show that the ligand is similarly bonded to the metal ion in solution. Ab initio quantum chemical studies show that the steric effect plays the key role in complexation behavior.

Host–guest supramolecular interactions in the coordination compounds of 4,4′-azobis(pyridine) with MnX2(X = NCS–, NCNCN–, and PF6–): structural analyses and theoretical study

Three new Mn(II) coordination compounds {[Mn(NCNCN)2(azpy)]·0.5azpy}n (1), {[Mn(NCS)2(azpy)(CH3OH)2]·azpy}n (2), and [Mn(azpy)2(H2O)4][Mn(azpy)(H2O)5]·4PF6·H2O·5.5azpy (3) (where azpy = 4,4'-azobis-(pyridine)) have been synthesized by self-assembly of the primary ligands, dicyanamide, thiocyanate, and hexafluorophosphate, respectively, together with azpy as the secondary spacer. All three complexes were characterized by elemental analyses, IR spectroscopy, thermal analyses, and single crystal X-ray crystallography. The structural analyses reveal that complex 1 forms a two-dimensional (2D) grid sheet motif These sheets assemble to form a microporous framework that incorporates coordination-free azpy by host-guest pi center dot center dot center dot pi. and C-H center dot center dot center dot N hydrogen bonding interactions. Complex 2 features azpy bridged one-dimensional (ID) chains of centrosymmetric [Mn(NCS)(2)(CH3OH)(2)} units which form a 2D porous sheet via a CH3 center dot center dot center dot pi supramolecular interaction. A guest azpy molecule is incorporated within the pores by strong H-bonding interactions. Complex 3 affords a 0-D motif with two monomeric Mn(II) units in the asymmetric unit. There exist pi center dot center dot center dot pi, anion center dot center dot center dot pi, and strong hydrogen bonding interactions between the azpy, water, and the anions. Density functional theory (DFT) calculations, at the M06/6-31+G* level of theory, are used to characterize a great variety of interactions that explicitly show the importance of host-guest supramolecular interactions for the stabilization of coordination compounds and creation of the fascinating three-dimensional (3D) architecture of the title compounds.

Synthesis and crystal structures of μ-oxido- and μ-hydroxido-bridged dinuclear iron(III) complexes with an N2O donor ligand - a theoretical study on the influence of weak forces on the Fe-O-Fe bridging angle

The synthesis and crystal structures of three nonheme di-iron(III) complexes with a tridentate N,N,O Schiff-base ligand, 2-({[2-(dimethylamino) ethyl] imino} methyl) phenol (HL), are reported. Complexes [Fe2OL2(NCO)(2)] (1a) and [Fe2OL2(SAL)(2)]center dot H2O [SAL = o-(CHO)C6H4O-] (1b) are unsupported mu-oxido-bridged dimers, and [Fe-2(OH)L-2(HCOO)(2)-(Cl)] (2) is a mu-hydroxido-bridged dimer supported by a formato bridging ligand. All complexes have been characterized by X-ray crystallography and spectroscopic analysis. Complex 1b has been reported previously; however, it has been reinvestigated to confirm the presence of a crucial water molecule in the solid state. Structural analyses show that in 1a the iron atoms are pentacoordinate with a bent Fe-O-Fe angle [142.7(2)degrees], whereas in 2 the metal centers are hexacoordinate with a normal Fe-OH-Fe bridging angle [137.9(2)degrees]. The Fe-O-Fe angles in complexes 1a and 1b differ significantly to those usually shown by (mu-oxido) Fe-III complexes. A theoretical study has been performed in order to rationalize this deviation. Moreover, the influence of the water molecule observed in the solid-state structure of 1b on the Fe-O-Fe angle is also analyzed theoretically.

Evolution of discrimination in populations at equilibrium between selfishness and altruism

Where there is genetically based variation in selfishness and altruism, as in man, altruists with an innate ability to recognise and thereby only help their altruistic relatives may evolve. Here we use diploid population genetic models to chart the evolution of genetically-based discrimination in populations initially in stable equilibrium between altruism and selfishness. The initial stable equilibria occur because help is assumed subject to diminishing returns. Similar results were obtained whether we used a model with two independently inherited loci, one controlling altruism the other discrimination, or a one locus model with three alleles. The latter is the opposite extreme to the first model, and can be thought of as involving complete linkage between two loci on the same chromosome. The introduction of discrimination reduced the benefits obtained by selfish individuals, more so as the number of discriminators increased, and selfishness was eventually eliminated in some cases. In others selfishness persisted and the evolutionary outcome was a stable equilibrium involving selfish individuals and both discriminating and non-discriminating altruists. Heritable variation in selfishness, altruism and discrimination is predicted to be particularly evident among full sibs. The suggested coexistence of these three genetic dispositions could explain widespread interest within human social groups as to who will and who will not help others. These predictions merit experimental and observational investigation by primatologists, anthropologists and psychologists. Keywords: Population genetics, Diploid, Heritability, Prosocial, Behaviour genetics

Trinuclear and tetranuclear adduct formation between sodium perchlorate and copper(II) complexes of salicylaldimine type ligands: structural characterization and theoretical investigation

The synthesis of two new sodium perchlorate adducts (1:2 and 1:3) with copper(II) "ligand-complexes'' is reported. One adduct is trinuclear [(CuL(1))(2)NaClO(4)] (1) and the other is tetranuclear [(CuL(2))(3)Na]ClO(4)center dot EtOH (2). The ligands are the tetradentate di-Schiff base of 1,3-propanediamines and salicylaldehyde (H(2)L(1)) or 2-hydroxyacetophenone (H(2)L(2)). Both complexes have been characterized by X-ray single crystal structure analyses. In both structures, the sodium cation has a six-coordinate distorted octahedral environment being bonded to four oxygen atoms from two Schiff-base complexes in addition to a chelated perchlorate anion in 1 and to six oxygen atoms from three Schiff-base complexes in 2. We have carried out a DFT theoretical study (RI-B97-D/def2-SVP level of theory) to compute and compare the formation energies of 1:2 and 1:3 adducts. The DFT study reveals that the latter is more stabilized than the former. The X-ray crystal structure of 1 shows that the packing of the trinuclear unit is controlled by unconventional C-H center dot center dot center dot O H-bonds and Cu(2+)-pi non-covalent interactions. These interactions explain the formation of 1 which is a priori disfavored with respect to 2.

Online data processing consent under EU law: a theoretical framework and empirical evidence from the UK

This article analyses the results of an empirical study on the 200 most popular UK-based websites in various sectors of e-commerce services. The study provides empirical evidence on unlawful processing of personal data. It comprises a survey on the methods used to seek and obtain consent to process personal data for direct marketing and advertisement, and a test on the frequency of unsolicited commercial emails (UCE) received by customers as a consequence of their registration and submission of personal information to a website. Part One of the article presents a conceptual and normative account of data protection, with a discussion of the ethical values on which EU data protection law is grounded and an outline of the elements that must be in place to seek and obtain valid consent to process personal data. Part Two discusses the outcomes of the empirical study, which unveils a significant departure between EU legal theory and practice in data protection. Although a wide majority of the websites in the sample (69%) has in place a system to ask separate consent for engaging in marketing activities, it is only 16.2% of them that obtain a consent which is valid under the standards set by EU law. The test with UCE shows that only one out of three websites (30.5%) respects the will of the data subject not to receive commercial communications. It also shows that, when submitting personal data in online transactions, there is a high probability (50%) of incurring in a website that will ignore the refusal of consent and will send UCE. The article concludes that there is severe lack of compliance of UK online service providers with essential requirements of data protection law. In this respect, it suggests that there is inappropriate standard of implementation, information and supervision by the UK authorities, especially in light of the clarifications provided at EU level.

Estimation of optimal gravity wave parameters for climate models using data assimilation

There is a current need to constrain the parameters of gravity wave drag (GWD) schemes in climate models using observational information instead of tuning them subjectively. In this work, an inverse technique is developed using data assimilation principles to estimate gravity wave parameters. Because mostGWDschemes assume instantaneous vertical propagation of gravity waves within a column, observations in a single column can be used to formulate a one-dimensional assimilation problem to estimate the unknown parameters. We define a cost function that measures the differences between the unresolved drag inferred from observations (referred to here as the ‘observed’ GWD) and the GWD calculated with a parametrisation scheme. The geometry of the cost function presents some difficulties, including multiple minima and ill-conditioning because of the non-independence of the gravity wave parameters. To overcome these difficulties we propose a genetic algorithm to minimize the cost function, which provides a robust parameter estimation over a broad range of prescribed ‘true’ parameters. When real experiments using an independent estimate of the ‘observed’ GWD are performed, physically unrealistic values of the parameters can result due to the non-independence of the parameters. However, by constraining one of the parameters to lie within a physically realistic range, this degeneracy is broken and the other parameters are also found to lie within physically realistic ranges. This argues for the essential physical self-consistency of the gravity wave scheme. A much better fit to the observed GWD at high latitudes is obtained when the parameters are allowed to vary with latitude. However, a close fit can be obtained either in the upper or the lower part of the profiles, but not in both at the same time. This result is a consequence of assuming an isotropic launch spectrum. The changes of sign in theGWDfound in the tropical lower stratosphere, which are associated with part of the quasi-biennial oscillation forcing, cannot be captured by the parametrisation with optimal parameters.

Hydrogen bonding in the gas-phase: the molecular structures of 2‑hydroxybenzamide (C7H7NO2) and 2‑methoxybenzamide (C8H9NO2), obtained by gas-phase electron diffraction and theoretical calculations

The structures of 2-hydroxybenzamide(C7H7NO2) and 2-methoxybenzamide (C8H9NO2) have been determined in the gas-phase by electron diffraction using results from quantum chemical calculations to inform restraints used on the structural parameters. Theoretical methods (HF and MP2/6-311+G(d,p)) predict four stable conformers for both 2-hydroxybenzamide and 2-methoxybenzamide. For both compounds, evidence for intramolecular hydrogen bonding is presented. In 2-hydroxybenzamide, the observed hydrogen bonded fragment is between the hydroxyl and carbonyl groups, while in 2-methoxybenzamide, the hydrogen bonded fragment is between one of the hydrogen atoms of the amide group and the methoxy oxygen atom.

Non-concordance between genetic profiles of olive oil and fruit: a cautionary note to the use of DNA markers for provenance testing.

To investigate the contribution of paternal alleles to the DNA content of olive oil, genetic analyses of olive DNA samples from fruits, leaves, and oil derived from the same tree (cv. Leccino) were carried out. DNA extracted from maternal tissues--leaves and flesh--from different fruits showed identical genetic profiles using a set of DNA markers. Additional simple sequence repeat (SSR) alleles, not found in the maternal samples, were amplified in the embryos (stone), and they were also detected in DNA extracted from the paste obtained by crushing whole fruits and from the oil pressed from this material. These results demonstrate that the DNA profile obtained from olive oil is likely to represent a composite profile of the maternal alleles juxtaposed with alleles contributed by various pollen donors. Therefore, care needs to be taken in the interpretation of DNA profiles obtained from DNA extracted from oil for resolving provenance and authenticity issues.

Climate change scenarios for precipitation extremes in Portugal

Precipitation indices are commonly used as climate change indicators. Considering four Climate Variability and Predictability-recommended indices, this study assesses possible changes in their spatial patterns over Portugal under future climatic conditions. Precipitation data from the regional climate model Consortium for Small-Scale Modelling–Climate version of the Local Model (CCLM) ensemble simulations with ECHAM5/MPI-OM1 boundary conditions are used for this purpose. For recent–past, medians and probability density functions of the CCLM-based indices are validated against station-based and gridded observational dataset from ENSEMBLES-based (gridded daily precipitation data provided by the European Climate Assessment & Dataset project) indices. It is demonstrated that the model is able to realistically reproduce not only precipitation but also the corresponding extreme indices. Climate change projections for 2071–2100 (A1B and B1 SRES scenarios) reveal significant decreases in total precipitation, particularly in autumn over northwestern and southern Portugal, though changes exhibit distinct local and seasonal patterns and are typically stronger for A1B than for B1. The increase in winter precipitation over northeastern Portugal in A1B is the most important exception to the overall drying trend. Contributions of extreme precipitation events to total precipitation are also expected to increase, mainly in winter and spring over northeastern Portugal. Strong projected increases in the dry spell lengths in autumn and spring are also noteworthy, giving evidence for an extension of the dry season from summer to spring and autumn. Although no coupling analysis is undertaken, these changes are qualitatively related to modifications in the large-scale circulation over the Euro-Atlantic area, more specifically to shifts in the position of the Azores High and associated changes in the large-scale pressure gradient over the area.

Graph-based algorithms for comparison and prediction of household-level energy use profiles

We present an efficient graph-based algorithm for quantifying the similarity of household-level energy use profiles, using a notion of similarity that allows for small time–shifts when comparing profiles. Experimental results on a real smart meter data set demonstrate that in cases of practical interest our technique is far faster than the existing method for computing the same similarity measure. Having a fast algorithm for measuring profile similarity improves the efficiency of tasks such as clustering of customers and cross-validation of forecasting methods using historical data. Furthermore, we apply a generalisation of our algorithm to produce substantially better household-level energy use forecasts from historical smart meter data.

Effect of provenance, plant part and processing on extract profiles from cultivated European Rhodiola rosea L. for medicinal use.

The demand for plant material of Rhodiola rosea L. (Crassulaceae) for medicinal use has increased recently, amid concerns about its quality and sustainability. We have analysed the content of phenylpropanoids (total rosavins) and salidroside in liquid extracts from 3-year old cultivated plants of European origin, and mapped the influence of plant part (rhizome versus root), genotype, drying, cutting, and extraction solvent to chemical composition. Rhizomes contained 1.5-4 times more salidroside (0.3-0.4% dry wt) and total rosavins (1.2-3.0%) than roots. The qualitative decisive phenylpropanoid content in the extracts was most influenced by plant part, solvent, and genotype, while drying temperature and cutting conditions were of less importance. We have shown that R. rosea from different boreal European provenances can be grown under temperate conditions and identified factors to obtain consistent high quality extracts provided that authentic germplasm is used and distinguished between rhizome, roots and their mixtures.