bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lifetime Shortening and Fast Energy‐Tansfer Processes upon Dimerization of a A‐π‐D‐π‐A Molecule
Authors: Collini Elisabetta , Bolzonello Luca , Zerbetto Mirco , Ferrante Camilla , Manfredi Norberto , Abbotto Alessandro 
Published: November 2013

AbstractTime‐resolved fluorescence and transient absorption experiments uncover a distinct change in the relaxation dynamics of the homo‐dimer formed by two 2,5‐bis[1‐(4‐N‐methylpyridinium)ethen‐2‐yl)]‐N‐methylpyrrole ditriflate (M) units linked by a short alkyl chain when compared to that of the monomer M. Fluorescence decay traces reveal characteristic decay times of 1.1 ns and 210 ps for M and the dimer, respectively. Transient absorption spectra in the spectral range of 425–1050 nm display similar spectral features for both systems, but strongly differ in the characteristic relaxation times gathered from a global fit of the experimental data. To rationalize the data we propose that after excitation of the dimer the energy localizes on one M branch and then decays to a dark state, peculiar only of the dimer. This dark state relaxes to the ground state within 210 ps through non‐radiative relaxation. The nature of the dark state is discussed in relation to different possible photophysical processes such as excimer formation and charge transfer between the two M units. Anisotropy decay traces of the probe‐beam differential transmittance of M and the dimer fall on complete different time scales as well. The anisotropy decay for M is satisfactorily ascribed to rotational diffusion in DMSO, whereas for the dimer it occurs on a faster time scale and is likely caused by energy‐transfer processes between the two monomer M units.
Significant Reduction in NiO Band Gap Upon Formation of LixNi1−xO alloys: Applications To Solar Energy Conversion
Authors: Alidoust Nima , Toroker Maytal Caspary , Keith John A. , Carter Emily A. 
Published: November 2013

AbstractLong‐term sustainable solar energy conversion relies on identifying economical and versatile semiconductor materials with appropriate band structures for photovoltaic and photocatalytic applications (e.g., band gaps of ∼1.5–2.0 eV). Nickel oxide (NiO) is an inexpensive yet highly promising candidate. Its charge‐transfer character may lead to longer carrier lifetimes needed for higher efficiencies, and its conduction band edge is suitable for driving hydrogen evolution via water‐splitting. However, NiO’s large band gap (∼4 eV) severely limits its use in practical applications. Our first‐principles quantum mechanics calculations show band gaps dramatically decrease to ∼2.0 eV when NiO is alloyed with Li2O. We show that LixNi1−xO alloys (with x=0.125 and 0.25) are p‐type semiconductors, contain states with no impurity levels in the gap and maintain NiO’s desirable charge‐transfer character. Lastly, we show that the alloys have potential for photoelectrochemical applications, with band edges well‐placed for photocatalytic hydrogen production and CO2 reduction, as well as in tandem dye‐sensitized solar cells as a photocathode.
Quantitative trait locus detection using combined linkage/disequilibrium analysis
Authors: Almasy Laura , Williams Jeff T. , Dyer Thomas D. , Blangero John 
Published: November 2013

AbstractWe describe an extension of the variance component linkage method that augments identity‐by‐descent information from relatives with identity‐by‐state information from unrelated individuals, exploiting disequilibrium to facilitate fine mapping of quantitative trait loci. An advantage of the combined linkage/disequilibrium test is that it detects association only in the presence of linkage and is not biased by population stratification.
Two tests of association for a susceptibility locus for families of variable size: An example using two sampling strategies
Authors: Monks S.A. , Martin E.R. , Umbach D.M. , Kaplan N.L. 
Published: November 2013

AbstractA two‐stage approach was used to analyze Problem 2 simulated data from Genetic Analysis Workshop 11. In the first stage, we tested for linkage with the Haseman‐Elston test in SIBPAL. Markers that were significant in the first stage were followed up with two types of association tests. These association tests differ in the type of family information used: 1) parental transmissions to affected children or 2) differences in marker allele frequencies between affected and unaffected siblings. We also explored how the conclusions changed when different sampling strategies were used. Of particular interest was whether the entire data set should be used to test for both linkage and association or whether the data set should be halved to allow for replication of the initial association results.
Generalization of the extended transmission disequilibrium test to two unlinked disease loci
Authors: Morris Andrew , Whittaker John 
Published: November 2013

AbstractThe extended transmission disequilibrium test (ETDT) of Sham and Curtis [1995] is a powerful test of the null hypothesis of no linkage between a multi‐allelic marker locus and a disease susceptibility locus of unknown location in the presence of association between alleles at the two loci. We propose a generalization of the ETDT to test simultaneously for linkage of markers to two unlinked disease loci. Analysis of the simulated data for Problem 2 would suggest improvements in power to detect linkage to pairs of disease loci over single locus tests. This is as a result of the two locus model taking account of epistasis between the disease loci.
Power of concordant versus discordant sib pairs at different penetrance levels
Authors: Nicolaou Michael , Premkumar Smita , Destefano Anita L. , Farrer Lindsay A. , Cupples L. Adrienne 
Published: November 2013

AbstractKnowing the answers, we used the GAW11 data set to compare the power and efficiency of discordant versus concordant affected sib pairs for qualitative traits at different levels of penetrance. Samples of 200 concordant sib pairs outperformed discordant sib pairs for low penetrance (40%) and 70% penetrance models while at 90% penetrance they performed equally well. Increasing the sample size of discordant sib pairs to twice that of concordant pairs was not enough to reach the power of concordant sib pairs at the 40% and 70% penetrance models. For low penetrance using a combination of concordant and discordant sib pairs resulted in higher power than using discordant sib pairs alone. At 90% penetrance, the power of concordant and discordant sib pairs was similar in the region close to the gene while concordant sib pairs performed better at locations further from the gene.
Covariates in linkage analysis
Authors: Rice John P. , Rochberg Nan , Neuman Rosalind J. , Saccone Nancy L. , Liu Kuang‐Yu , Zhang Xu , Culverhouse Robert 
Published: November 2013

AbstractWe apply a novel technique to detect significant covariates in linkage analysis using a logistic regression approach. An overall test of linkage is first performed to determine whether there is significant perturbation from the expected 50% sharing under the hypothesis of no linkage; if the overall test is significant, the importance of the individual covariate is assessed. In addition, association analyses were performed. These methods were applied to simulated data from multiple populations, and detected correct marker linkages and associations. No population heterogeneity was detected. These methods have the advantages of using all sib pairs and of providing a formal test for heterogeneity across populations
Issues in genomic screening: Critical values, sample sizes, and the ability to detect linkage
Authors: Rogus John J. , Cai Tianxi , Wei Lee‐Jen 
Published: November 2013

AbstractThe aims of this study were to empirically investigate the ability of affected sib pairs (ASPs) to localize a gene through screening and to explore estimation of lod score critical values through resampling. To do so, we repartitioned 25 replicates of 100 simulated nuclear families into six data sets of sizes 100, 200, 300, 400, 500, and 1,000 and chose at most one mildly ASP per family. Using all marker data, we calculated maximum lod scores across the six‐chromosome genome for each set. Then, we determined the cutoff value corresponding to a 5% genome‐wide false positive rate using both the method of Lander and Kruglyak [1995] and a simple resampling algorithm that allows greater scan‐specific flexibility. For chromosome 1, the ability of the ASPs to detect the region between markers 9 and 10 clearly increases with the sample size, and genome‐wide significance is achieved for samples of size 400 or greater. Also, as expected, the critical values based on the less conservative resampling approach are generally slightly smaller than those from theoretical calculations based on the Ornstein‐Uhlenbeck diffusion process of Lander and Kruglyak.
A bayesian approach to replication of linkage findings
Authors: Wang Kai , Vieland Veronica , Huang Jian 
Published: November 2013

AbstractA novel Bayesian approach to replication studies, allowing for locus heterogeneity, is introduced. Compared with currently used approaches to replication, it offers a natural way to accumulate evidence across independently collected data sets and yields more interpretable results. Using four replicates (one as initial study and the other three as replication studies) from Problem 2 of the Genetic Analysis Workshop 11 data, we show the performance of this method. All four disease susceptibility loci (D1G009, D1G024, D3G045, D5G035) are identified and accurately mapped, with no false positive signals.
Comparison of evidence supporting a chromosome 6 alcoholism gene
Authors: Cantor Rita M. , Lanning Christopher D. 
Published: November 2013

AbstractA whole genome scan has been conducted on 105 families ascertained for probands with a diagnosis of alcoholism by the Collaborative Study on the Genetics of Alcoholism (COGA). To identify chromosomal regions likely to contain genes contributing to the development of this disorder, data from 296 highly polymorphic markers have been analyzed using the MAPMAKER/SIBS [Kruglyak and Lander, 1995] and GENEHUNTER‐PLUS [Kruglyak et al., 1996; Kong and Cox, 1997] multipoint linkage programs. Chromosome 6 exhibited lod scores greater than 3.0 and was further tested by two‐point linkage analyses at each marker along the chromosome to assess the consistency of results from these allele sharing linkage programs. Two‐point linkage was assessed with MAPMAKER/SIBS, GENEHUNTER‐PLUS and the SIBPAL subprogram of the SAGE package of genetic epidemiology programs [Elston, 1997].
Using recursive partitioning for exploration and follow‐up of linkage and association analyses
Authors: Wilcox Marsha A. , Smoller Jordan W. , Lunetta Kathryn L. , Neuberg Donna 
Published: November 2013

AbstractWe first conducted a genome‐wide screen for association with discordant sibships using the multi allelic and diallelic SDT. Markers at D4S1628, D8S1109, D9S66 and D7S1797 showed multi‐allelic association. Deleterious diallelic association was found for markers at D1S1613, D1S534, D3S2459, D7S1817, and D9S131. Protective association was found at markers D8S1109, D8S1136, and D9S66. We then incorporated these findings with previous linkage findings in the exploration of oligogenes and epistasis using recursive partitioning. We conclude that recursive partitioning can be a useful adjunct to traditional linkage and association analyses in the exploration of these effects.
Linkage analysis in alcohol dependence
Authors: Windemuth Christine , Hahn Andreas , Strauch Konstantin , Baur Max P. , Wienker Thomas F. 
Published: November 2013

AbstractAlcohol dependence often is a familial disorder and has a genetic component. Research in causative factors of alcoholism is coordinated by a multi‐center program, COGA [The Collaborative Study on the Genetics of Alcoholism, Begleiter et al., 1995]. We analyzed a subset of the COGA family sample, 84 pedigrees of Caucasian ancestry comprising 745 persons, 339 of whom are affected according to DSM‐III‐R and Feighner criteria. Using parametric and nonparametric methods, evidence for linkage was found on chromosome 1 (near markers D1S532, D1S1588, and D1S534), as well as on chromosome 15 (near marker D15S642). Other regions of the genome showed suggestive evidence for contributing loci. Related findings are discussed in recent publications investigating linkage in humans [Reich et al., 1998] and mice [Melo et al., 1996].
Search for a gene×environment interaction: G×E hunt
Authors: Bailey Julia N. , Suchard Marc A. , Smalley Susan L. , Sinsheimer Janet S. 
Published: November 2013

AbstractWe developed a method to identify gene×environment interactions (G×Es). To test this method in the simulated data (Problem 2, GAW11), we first identified an environmental factor (E1) that was associated with the simulated disorder. We stratified affected sibling pairs (ASPs) into two groups, those concordant for the presence of E1 and those concordant for the absence of E1. We then localized genes on chromosomes 3 and 5 using identity‐by‐descent (IBD) sharing rates among ASPs. Because the stratified IBD sharing rates are independent of the environmental factor if there is no G×E, we inferred the existence of a G×E near loci 3G44 and 3G45 by testing whether the proportion of ASPs sharing no alleles IBD differed among the two groups.
Biological Productivity in the Dead Sea Part I. Microorganisms in the Water Column
Authors: Kaplan I.R. , Friedmann A. 
Published: November 2013

AbstractStudies were performed to determine the distribution of microbiota in the Dead Sea during 1963 to 1965. The dominant organisms in the surface water were found to be two red halophilic bacteria, followed in abundance by a green flagellated alga, Dunaliella virdis. Cultures inoculated with Dead Sea water produced growth of the red bacteria as well as unidentified non‐pigmented halo‐tolerant bacteria, capable of growing in 25% salt solution, and bacteria that grew only in dilute salt media. The latter are mainly spore‐forming aerobes, probably introduced by rain‐wash of the soil, as well as from the Jordan River and fresh water springs. Sulfate reducing bacteria were also cultured from the water and from the sediment. Pigment studies on extracts from laboratory cultures of the red bacteria, from centrifuged suspensions of Dead Sea water and, by comparison, from a pure culture of Halobacterium salinarium, showed that the dominant pigment in all cases was the carotene α‐bacteriorubrin. The total number of organisms decreased with depth of the water column, especially below the thermocline. The interpretations given for the decrease are: lack of dissolved oxygen, decrease in incident light, and lack of dissolved phosphate. The last factor is probably due to rapid precipitation of phosphate by divalent ions.
Ion Solvation in Solution, Studied by Nuclear Magnetic Resonance Spectroscopy
Authors: Luz Z. 
Published: November 2013

AbstractThe use of nuclear magnetic resonance spectroscopy for the study of the properties and structure of solvation shell complexes is discussed through the example of Co2+ ions in methanol. New proton relaxation and shift measurements in solutions of Mn(ClO4)2 and Cr(ClO4)3 in anhydrous methanol are described and analyzed. The results yield kinetic and magnetic parameters for the [Mn(CH3OH)6]2+ and [Cr(CH3OH)6]3+ solvates. The dominant kinetic process for Mn2+ involves exchange of whole molecules in and out of the solvation shell, while for Cr3+ only the protolysis reaction of the hydroxyl protons affects the NMR resonance. Both ions have relatively long electron spin relaxation times and it is therefore not possible to observe their solvation shell directly. Preliminary results on Cu2+ solvates are also discussed.
Selectivity in Fast Reactions of Aqueous Oh‐Radicals with Amides
Authors: Lichtin N.N. 
Published: November 2013

AbstractMeasurement of rates of abstraction of H atoms by aqueous OH radicals from specific sites in aliphatic amides by the technique of pulse radiolysis‐kinetic spectroscopy establishes that in this reaction, in which gross rates of reaction fall short of the diffusion‐controlled limit by no more than a factor of 102, there is a systematic variation of reactivity with structure. This variation parallels dependence of reactivity upon structure observed in the reactions of several other free radicals in the gas phase.
Bipolar Membranes Made of a Single Polyolephine Sheet
Authors: De Körösy F. , Zeigerson E. 
Published: November 2013

AbstractThe preparation of bipolar membranes from a single sheet of polyolephine by sulphochlorination is described in detail. Rectification experiments between salt solutions and between HCl and NaOH solutions respectively are described. The transference of salt ions relative to each other and relative to the ions of water have been determined. Some analytical data on the concentration of mobile ions in the membranes during current transport are given. The mechanism of rectification is explained and used to clarify the experimental results. Problems concerning conduction in bipolar membranes are enumerated and some experiments are proposed which may assist in solving them.
Fast Consecutive Intramolecular Processes Involving Protein and Fe(III) in Ferri‐Cytochrome‐c in Aqueous Solution
Authors: Lichtin N.N. , Ogdan J. , Stein G. 
Published: November 2013

AbstractThe reaction of H atoms (produced by nanosecond pulse radiolysis) with ferri‐cytochrome‐c in aqueous solution results in the second order formation of an absorption spectrum due to the addition of H atoms to the enzyme protein. This spectrum is not specific to the iron moiety. The rate constant of the addition is 1×1010M−1 sec−1. This is followed by two first order intramolecular processes with specific rates of ∼ 1×105 sec−1 and ∼ 2×104 sec−1. In these processes, specific spectra related to the α and β bands of ferro‐cytochrome‐c appear. The results are interpreted to show reduction equivalent transfer through the protein to the iron moiety.
Interaction Between Montmorillonite and Benzidine in Aqueous Solutions II. A General Kinetic Study
Authors: Lahav N. , Raziel S. 
Published: November 2013

AbstractA kinetic study of the formation of benzidine blue on montmorillonite was carried out by measuring the absorbance of the suspension at 580 nm. A preliminary study of the first stage of the reaction was conducted by stopped flow apparatus. The main change in the light absorbance took place during the first minutes of the reaction, but the reaction proceeded at a very slow rate for hours and days. The reaction rate became slower upon increasing the pH and upon addition of calgon (Na‐hexametaphosphate).
Topochemical Reactions of Monomers with Conjugated Triple‐Bonds VII Mechanism of Transition from Monomer to Polymer Phase During Solid‐State Polymerisation
Authors: Kaiser J. , Wegner G. , Fischer E. W. 
Published: November 2013

AbstractThe lattice‐controlled solid‐state polymerisation of three different modifications of 2,4‐hexadiin‐1,6‐diol‐bis(phenylurethane) was investigated by X‐ray and optical methods. The polymerisation is a homogeneous reaction. The polymer grows in the form of single chains within the crystal of the monomer. The chains extend along a definite crystallographic direction. Monomer and polymer are isomorphous and monomer‐polymer single crystals of various compositions are obtained up to a quantitative conversion in the case of modification I or III. Phase separation into a mesomorphic polymer and oriented monomer phase was observed on annealing partially polymerised single‐crystals of modification II below the transition point to modification III.
New Observations on Tautomerism and Ionization Processes in Hypoxanthines and 6‐Thiopurines
Authors: Lichtenberg D. , Bergmann F. , Neiman Z. 
Published: November 2013

AbstractUltraviolet spectra show that hypoxanthine and 6‐thiopurine are present in aqueous solution predominantly as 1H, 9H‐tautomers. However, a 3‐methyl group causes the imidazole ring to assume the 7‐NH form. The sequence of anion formation in hypoxanthine is 9(7) → 1 and in 6‐thiopurine 1 → 9(7). The NMR spectra suggest that the mono‐anion of hypoxanthine is a mixture of tautomers. Protonation always takes place in the imidazole ring, with the exception of 3‐methyl derivatives. In the latter, formation of mono‐cations involves the pyrimidine moiety.
Interaction Between Montmorillonite and Benzidine in Aqueous Solutions III. The Color Reaction in the Air Dry State
Authors: Lahav N. 
Published: November 2013

AbstractThe transformation of the blue color of bentonite‐benzidine pastes to green or yellow‐green upon air drying was studied by means of reflectance measurements and by comparison of the samples under study with color charts. The relative amounts of benzidine and bentonite and the relative humidity had a decisive effect on the color of the air dried films. Hygroscopic compounds such as LiCl and CaCl2 produced results similar to that produced by increasing the relative humidity. The explanation of the color reactions is based on the assumption that the (blue) monovalent and the (yellow) divalent cations coexist in the air dry benzidine‐bentonite films.
The Use of Free Radical Probes in the Study of Mechanisms of Enzyme Inactivation
Authors: Adams G. E. , Redpath J. L. , Bisby R. H. , Cundall R. B. 
Published: November 2013

AbstractSome inorganic radical‐anions, which have very strong absorption spectra, have some oxidative reaction specificity with amino acids. Combined pulse radiolysis and inactivation studies on the reactions of these radicals with several enzymes lead to identification of amino acid residues essential to enzymic activity. Data are reviewed for the enzymes, lysozyme, ribonuclease, trypsin, α‐chymotrypsin, papain and carboxypeptidase. The reducing radical, CO2−, is more selective than the hydrated electron in its reactions with enzymes and proteins. Results from pulse radiolysis studies in electron‐transfer and other reactions involving CO2− are compared with results from inactivation studies with lysozyme and ribonuclease.
Primary Events in the Radiolysis of Nucleic Acids and their Components
Authors: Scholes G. 
Published: November 2013

AbstractThe radiolysis of dilute aqueous solutions of DNA and its components is discussed, with particular reference to the rates of reaction and the sites of reaction of the primary reactive species, OH, H and e−aq. Recent work on the formation and subsequent reactions of OH− and electron‐adducts of pyrimidines is described.
DNA Lesions and Mammalian Cell Killing: Cause and Effect?
Authors: Elkind M. M. , Ben‐Hur Ehud 
Published: November 2013

AbstractAlthough indirect, studies of repair mechanisms afford a useful approach to the questions: Where and what are the sensitive sites in a cell related to division? This approach has been used with mammalian cells based on the fact that sublethal damage must be accumulated to kill a cell and the observation that cells can repair sublethal damage. Actinomycin D was found to inhibit this repair, an observation which justified a focus upon nuclear DNA as the site of damage and repair. Sedimentation studies with alkaline gradients revealed two repair processes. Repair of single‐strand breaks (also found by others) and repair to a complex of DNA, lipid, and protein. In cells sensitized to fluorescent light because of prior growth in the presence of 5‐bromodeoxyuridine, the data suggest that single‐strand breaks is the lethal lesion. In contrast, damage to a DNA‐membrane structure appears a more likely target for X‐ray cell killing.