Structure of 6,5'-anhydro-6-hydroxy-2',3' O-isopropylideneuridine

CI2HI4N206, Mr=282"3, orthorhombic,P21212 t, a = 10.412 (2), b = 14.936 (2), c =16.651(3),/k, V=2589.46A 3, Z--8, Din= 1.450, D x = 1.447 Mg m -3, 2(Cu Kct) = 1.5418/~, # =0.902mm -~, F(000)-- 1184.00, T= 293 K, R = 0.039, wR--0.038 for 2548 unique reflections with F > 3a(F). The two crystallographically independent molecules in the asymmetric unit have similar geome-tries with the ribose ring having an O(4')-exo, C(4')-endo pucker and the uracil base in the anti conformation.The geometry about the exocyclic C(4')-C(5') bond in both molecules is gauche-gauche. The dioxolane ring assumes twist conformations in both molecules.

Pitkittäistutkimus paluumuuttajien odotusten toteutumisen vaikutuksesta psykologiseen sopeutumiseen

Tutkimuksessa tarkasteltiin inkerinsuomalaisten muuttoa edeltävien odotusten toteutumisen yhteyttä psykologiseen sopeutumiseen. Psykologisen sopeutumisen indikaattorina käytettiin elämään tyytyväisyyttä. Tutkimuksen tavoitteena oli tuoda esille sopeutumista prosessina, joka alkaa jo ennen muuttoa (pre-akkulturaatio) sekä luoda uutta tietoa paluumuuttajien odotusten toteutumisen vaikutuksesta sopeutumiseen. Toteutuneiden odotusten tutkimuskenttä muodostaa oman tutkimusperinteensä, jonka piirissä on pyritty selvittämään odotusten ja kokemusten välisen suhteen yhteyttä tyytyväisyyteen eri konteksteissa. Akkulturaatiotutkimuksissa korostetaan, että maahanmuuttajien epärealistiset odotukset muuton jälkeisestä elämästä vaikeuttavat sopeutumisprosessia. Tässä pitkittäistutkimuksessa toteutuneiden odotusten yhteyttä elämään tyytyväisyyteen tarkasteltiin paluumuuttokontekstissa kolmen vaihtoehtoisen mallin avulla. Ideaalitaso-mallin mukaan odotusten toteutuminen nostaa elämään tyytyväisyyttä ja toteutumatta jääminen laskee sitä. Ei vahvistusta –mallissa elämään tyytyväisyyden oletetaan olevan korkeimmillaan silloin, kun kokemukset ylittävät odotukset. Vain kokemus –mallin mukaan hyvät kokemukset muuton jälkeen nostavat elämään tyytyväisyyttä odotusten tasosta riippumatta. Malleja testattiin erikseen sosio-psyykkiseen hyvinvointiin ja ammatillis-taloudelliseen hyvinvointiin liittyvien odotusten suhteen. Perhe- ja ystäväsuhteiden laadun sekä ammatillisten mahdollisuuksien ja taloudellisen tilanteen tason on osoitettu olevan yhteydessä elämään tyytyväisyyteen. Maahanmuuttajien odotuksien on niin ikään todettu koskevan näitä elämänlaatua indikoivia osa-alueita. Tutkimuksen aineisto koostui etniseltä taustaltaan inkerinsuomalaisista (N=141) paluumuuttajista. Lähtökohta-aineisto kerättiin Venäjällä ennen muuttoa ja seurantavaihe toteutettiin noin vuosi muuton jälkeen. Aineiston analysoinnissa huomioitiin ajankohtainen metodologiakeskustelu ja kahden muuttujan välisen suhteen vaikutusta riippuvaan muuttujaan tarkasteltiin polynomisen regressioanalyysin ja vastepintamallinnuksen avulla. Näin tehden voitiin välttää toteutuneiden odotusten tutkimuksille tyypilliset mittaus- ja metodologiaongelmat: retrospektiivisyys, erotuspistemäärien käyttö ja lineaaristen mallien käyttö. Tutkimuksen aineisto tuki ei vahvistusta –mallin mukaista yhteyttä odotusten toteutumisen ja elämään tyytyväisyyden välillä. Yhteyttä voitiin tarkastella vain sosio-psyykkiseen hyvinvointiin liittyvien odotusten ja kokemusten suhteen, koska ammatillis-taloudelliseen hyvinvointiin liittyvät odotukset, kokemukset tai niistä muodostetut interaktiotermit eivät polynomisen regressioanalyysin tulosten mukaan olleet yhteydessä elämään tyytyväisyyteen tilastollisesti merkitsevästi. Paluumuuttajien elämään tyytyväisyys oli korkeimmillaan silloin, kun sosio-psyykkiseen hyvinvointiin liittyvät kokemukset ylittivät odotukset. Odotusten ja kokemusten välisen eroavuuden suunnalla siis on tämän tutkimuksen tulosten perusteella merkitystä psykologisen sopeutumisen kannalta. Tutkimuksen tulos tukee näkemystä, jonka mukaan maahanmuuttajien sopeutumisprosessia tulisi tarkastella pitkittäisasetelmassa muuttoa edeltävä vaihe huomioiden. Lisäksi tutkimus avaa yhden näkökulman siihen, minkä elämän osa-alueiden laatu on paluumuuttajien sopeutumisen kannalta merkityksellistä.

Saamelainen Kelan asiakkaana. Saamelaisten oikeudet ja asema alkuperäiskansana Kelan toimeenpanemassa sosiaaliturvassa

55 s.

Characterization of electroless nickel by esca

Eiectroless nickel (EN) deposits obtained from alkaline EN baths employing citrate or glycine as complexing agents and triethanoiamine as an additive are characterized by ESCA. This study reveals that Ni and P in EN are present as Niδ+ and Pδ− species. Besides these, NiO and NiPO4 are present as surface species. They confer passivity on EN and thereby contribute to its corrosion resistance.

Narrowband random excitation of a limit cycle system

The response of the Van der Pol oscillator to stationary narrowband Gaussian excitation is considered. The central frequency of excitation is taken to be in the neighborhood of the system limit cycle frequency. The solution is obtained using a non-Gaussian closure approximation on the probability density function of the response. The validity of the solution is examined with the help of a stochastic stability analysis. Solution based on Stratonovich''s quasistatic averaging technique is also obtained. The comparison of the theoretical solutions with the digital simulations shows that the theoretical estimates are reasonably good.

Reactivity Of Pph3 Toward Ruiiruiiicl(O2car)4 - Syntheses, Molecular-Structures, And Spectroscopic And Electrochemical Properties Of Ruiiruiii(Oh2)Cl(Mecn)(O2car)4(Pph3)2 And Ruii2(Oh2)(Mecn)2(O2car)4(Pph3)2

By the reaction of Ru2Cl(O2CAr)4 (1) and PPh3 in MeCN-H2O the diruthenium(II,III) and diruthenium(II) compounds of the type Ru2(OH2)Cl(MeCN)(O2CAr)4(PPh3)2 (2) and Ru2(OH2)(MeCN)2(O2CAr)4(PPh3)2 (3) were prepared and characterized by analytical, spectral, and electrochemical data (Ar is an aryl group, C6H4-p-X; X = H, OMe, Me, Cl, NO2). The molecular structure of Ru2(OH2)Cl(MeCN)(O2CC6H4-p-OMe)4(PPh3)2 was determined by X-ray crystallography. Crystal data are as follows: triclinic, P1BAR, a = 13.538 (5) angstrom, b = 15.650 (4) angstrom, c = 18.287 (7) angstrom, alpha = 101.39 (3)-degrees, beta = 105.99 (4)-degrees, gamma = 97.94 (3)-degrees, V = 3574 angstrom 3, Z = 2. The molecule is asymmetric, and the two ruthenium centers are clearly distinguishable. The Ru(III)-Ru(II), Ru(III)-(mu-OH2), and Ru(II)-(mu-OH2) distances and the Ru-(mu-OH2)-Ru angle in [{Ru(III)Cl(eta-1-O2CC6H4-p-OMe)(PPh3)}(mu-OH2)(mu-O2CC6H4-p-OMe)2{Ru(II)(MeCN)(eta-1-O2CC6H4-p-OMe)(PPh3)}] are 3.604 (1), 2.127 (8), and 2.141 (10) angstrom and 115.2 (5)-degrees, respectively. The compounds are paramagnetic and exhibit axial EPR spectra in the polycrystalline form. An intervalence transfer (IT) transition is observed in the range 900-960 nm in chloroform in these class II type trapped mixed-valence species 2. Compound 2 displays metal-centered one-electron reduction and oxidation processes near -0.4 and +0.6 V (vs SCE), respectively in CH2Cl2-TBAP. Compound 2 is unstable in solution phase and disproportionates to (mu-aquo)diruthenium(II) and (mu-oxo)diruthenium(III) complexes. The mechanistic aspects of the core conversion are discussed. The molecular structure of a diruthenium(II) compound, Ru2(OH2)(MeCN)2(O2CC6H4-p-NO2)4(PPh3)2.1.5CH2Cl2, was obtained by X-ray crystallography. The compound crystallizes in the space group P2(1)/c with a = 23.472 (6) angstrom, b = 14.303 (3) angstrom, c = 23.256 (7) angstrom, beta = 101.69 (2)-degrees, V = 7645 angstrom 3, and Z = 4. The Ru(II)-Ru(II) and two Ru(II)-(mu-OH2) distances and the Ru(II)-(mu-OH2)-Ru(II) angle in [{(PPh3)-(MeCN)(eta-1-O2CC6H4-p-NO2)Ru}2(mu-OH2)(mu-O2CC6H4-p-NO2)2] are 3.712 (1), 2.173 (9), and 2.162 (9) angstrom and 117.8 (4)-degrees, respectively. In both diruthenium(II,III) and diruthenium(II) compounds, each metal center has three facial ligands of varying pi-acidity and the aquo bridges are strongly hydrogen bonded with the eta-1-carboxylato facial ligands. The diruthenium(II) compounds are diamagnetic and exhibit characteristic H-1 NMR spectra in CDCl3. These compounds display two metal-centered one-electron oxidations near +0.3 and +1.0 V (vs SCE) in CH2Cl2-TBAP. The overall reaction between 1 and PPh3 in MeCN-H2O through the intermediacy of 2 is of the disproportionation type. The significant role of facial as well as bridging ligands in stabilizing the core structures is observed from electrochemical studies.

Lectio Praecursoria: Jännittäminen ja opiskelukyky

Aineisto on Keskustakampuksen kirjaston digitoimaa ja kirjasto vastaa aineiston käyttöluvista.

On the High Frequency Dielectric Behavior of Castor Oil

The low frequency dielectric behavior of castor oil (a vegetable oil) has been analyzed quite exhaustively in the context of its application as impregnant in capacitors. For the sake of completeness and in order to understand the relaxation phenomena in this liquid dielectric, this high frequency dielectric study was undertaken. In order to compare its properties with a liquid dielectric used in similar application and whose high frequency behavior has been quite well analyzed, Arochlor 1476 was studied. It is observed that both liquids have distributed relaxation times. The distribution parameters together with the two distinct relaxation times have been calculated by measuring the average relaxation time. It has been found that the distinct relaxation times thus calculated represent the dielectric behavior quite satisfactorily. The average dipole moments, dipole radii and thermal activation energies for dipole relaxation have also been evaluated.

Thermodynamic Properties of Niobium Oxides

Thermodynamic properties of three oxides of niobium have been measured using solid state electrochemical cells incorporating yttria-doped thoria (YDT) as the electrolyte in the temperature range T = (1000 to 1300) K. The standard Gibbs energies of formation of NbO, NbO2, and NbO2.422 from the elements can be expressed as: Delta(f)G(NbO)(o) +/- 547/J . mol(-1) = -414 986 + 86.861(T/K) Delta(f)G(NbO2)(o) +/- 548/J . mol(-1) = -779 864 + 164.438(T/K) Delta(f)G(NbO2.422)(o) +/- 775/J . mol(-1) = -911 045 + 197.932(T/K) The results are discussed in comparison with thermodynamic data reported in the literature. The new results refine data for NbO and NbO2 presented in standard data compilations. There are no data in thermodynamic compilations for NbO2.422 (Nb12O29). In the absence of the heat capacity and enthalpy of formation measurements, only the Gibbs energy of formation of NbO2.422 can be assessed. The free energy of formation of stoichiometric Nb2O5 is evaluated on the basis of measurements on NbO2.422 and information available in the literature on phase boundary compositions and isothermal variation of nonstoichiometric parameter with oxygen potential for Nb2O5-x. The results suggest a minor revision of data for Nb2O5. A minimum in the Gibbs energy of mixing for the system Nb-O occurs in the nonstoichiometric domain of Nb2O5-x with x = 0.036.

On reconfirming the evidence for pre-imaginal caste bias in a primitively eusocial wasp

Caste is usually thought to be determined entirely in the adult stage in most primitively eusocial wasps and bees. A pre-imaginal caste bias has however been recently discovered in the primitively eusocial waspRopalidia marginata. This study also suggested that reigning queens and possibly other adults may influence the production of new queens and implied at least partial support to the parental manipulation or sub-fertility hypothesis for the evolution of insect sociality. The interest of these results prompted an attempt at their reconfirmation. Complete reconfirmation has now been obtained using data from an independent experiment and two additional methods of data analysis. We therefore conclude that caste is at least partly determined prior to eclosion in the primitively eusocial waspRopalidia marginata which lacks morphological differentiation between egg-layers and non-egg-layers.

Ferrous-iron induces lipid peroxidation with little damage to energy transduction in mitochondria

Addition of ferrous sulfate, but not ferric chloride, in micromolar concentrations to rat liver mitochondria induced high rates of consumption of oxygen. The oxygen consumed was several times in excess of the reducing capacity of ferrous-iron (O: Fe ratios 5�8). This occurred in the absence of NADPH or any exogenous oxidizable substrate. The reaction terminated on oxidation of ferrous ions. Malondialdehyde (MDA), measured as thiobarbituric acid-reacting material, was produced indicating peroxidation of lipids. The ratio of O2: MDA was about 4: 1. Pretreatment of mitochondria with ferrous sulfate decreased the rate of oxidation (state 3) with glutamate (+malate) as the substrate by about 40% but caused little damage to energy tranduction process as represented by ratios of ADP: O and respiratory control, as well as calcium-stimulated oxygen uptake and energy-dependent uptake of [45Ca]-calcium. Addition of succinate or ubiquinone decreased ferrous iron-induced lipid peroxidation in intact mitochondria. In frozen-thawed mitochondria, addition of succinate enhanced lipid peroxidation whereas ubiquinone had little effect. These results suggest that ferrous-iron can cause peroxidation of mitochondrial lipids without affecting the energy transduction systems, and that succinate and ubiquinone can offer protection from damage due to such ferrous-iron released from the stores within the cells.

Molecular theory of underdamped dielectric relaxation: understanding collective effects in dipolar liquids

A molecular theory of underdamped dielectric relaxation of a dense dipolar liquid is presented. This theory properly takes into account the collective effects that are present (due to strong intermolecular correlations) in a dipolar liquid. For small rigid molecules, the theory again leads to a three-variable description which, however, is somewhat different from the traditional version. In particular, two of the three parameters are collective in nature and are determined by the orientational pair correlation function. A detailed comparison between the theory and the computer simulation results of Neria and Nitzan is performed and an excellent agreement is obtained without the use of any adjustable or free parameter - the calculation is fully microscopic. The theory can also provide a systematic description of the Poley absorption often observed in dipolar liquids in the high-frequency regime.