bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ab initioMODPOT/VRDDO/MERGE calculations on energetic compounds. III. Nitroexplosives: Polyaminopolynitrobenzenes (including DATB, TATB, and tetryl)
Authors: Hariharan P. C. , Koski Walter S. , Kaufman Joyce J. , Miller Richard S. 
Published: December 2004

AbstractQuantum chemical ab initio MODPOT/VRDDO calculations have been carried out on the following aminonitrobenzenes for which crystal structures had been determined experimentally: 4‐nitroaniline; N,N‐dimethyl‐p‐nitroaniline; 2,4,6‐trinitroaniline; 1,3‐diamino‐2,4,6‐trinitrobenzene (DATB—Form I); 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB); 2,3,4,6‐tetranitroaniline; N‐methyl‐N,2,4,6‐tetranitroaniline (Tetryl); and N‐(β,β,β‐trifluoroethyl)‐N,2,4,6‐tetranitroaniline. These quantum chemical calculations were performed on the molecules in their conformations as found in their crystal structures. The calculations were carried out with our own ab initio programs which also incorporate as options several desirable features for calculations on large molecules: ab initio effective core model potentials (MODPOT) which enable calculations of valence electrons only explicitly, yet accurately, and a charge conserving integral prescreening evaluation (which we named VRDDO‐variable retention of diatomic differential overlap) especially effective for spatially extended molecules. Aminonitrobenzenes are especially interesting since there are inherent intramolecular ring distortions and deviations from planarity and intramolecular hydrogen bonds as well as intermolecular hydrogen bonds causing further deviations from planarity. The theoretical indices resulting from the quantum chemical calculations are relevant to a number of properties and behavioral characteristics of these molecules, both intramolecular and intermolecular. The charges on the atoms [from the gross atomic populations (GAP's)] are needed for calculation of the atomic multipole–atomic multipole electrostatic contributions (a dominant factor) to the intermolecular interaction energies. These electrostatic interaction energies are part of the input necessary for calculations on the crystal packing and densities of these molecules. These GAP's are also of value in interpreting the experimental photoelectron and ESCA spectra of these molecules. The total overlap populations (TOP's) between atoms are related to the inherent bond strengths and can serve as a quantitative replacement for the old empirical bond length‐bond order‐bond energy relationship still used by explosives chemists to identify the “target bonds” (the weakest bonds). The TOP's are of considerable value in predicting and tracing initiation and subsequent steps of explosive phenomena. The molecular orbital energies of the lowest unoccupied orbitals are of interest since nitroexplosives have been implicated in testicular toxicity and the initial metabolic activation appears to proceed through a one‐electron reduction of the nitroexplosive.
Photoreactions on finely divided semiconductors
Authors: Peshev O. 
Published: December 2004

AbstractPhotoreactions on finely divided semiconductors are discussed. Experimental results on photo‐oxidation of CO, isobutane, and NH3 over UV‐irradiated n‐TiO2 (anatase) particles of different size are discussed. The possibility of using size‐quantized films for spectroscopy of adsorbates is also considered.
Theory of living State. VII. Bose–Einstein‐like ordering in temperature and time domain
Authors: Mishra R. K. , Bhowmik K. 
Published: December 2004

AbstractThe Bose–Einstein‐like ordering was earlier proposed as an important mechanism of energy handling in the living systems. In this regard two questions arise at once: (1) is such ordering feasible at body temperature and (2) what is the time that may be taken for establishing coherence? In this paper we hope to answer and satisfy these two questions.
Three‐body nonadditive effects for hydrogen bonded water molecules: SCF study of hydrated species including H2S and various metal ions
Authors: Novaro O. 
Published: December 2004

AbstractThe relative importance of purely nonadditive three‐body terms in solvated systems is assessed through ab initio LCAO–MO–SCF studies of hydrogen bonded structures containing two or more water molecules plus a solvate species. Among the latter the cases of Li+, Ca2+, and Mg2+ ions (of biological interest for aminoacid release processes in membrane transport) and of HDS molecules (of industrial importance in processes for the production of heavy water) are studied.
Quantum chemical study of the molecular patterns of MAO inhibitors and substrates
Authors: Martin M. , Sanz F. , Campillo M. , Pardo L. , Pérez J. , Turmo J. 
Published: December 2004

AbstractSimilarities and differences between mitochondrial monoamine oxidase (MAO) substrates and inhibitors (both A and B types) are considered, studying quantitatively two molecular properties: electron density and molecular electrostatic potential (MEP). The following molecules are considered: substrates: PHEA, BZA, tele‐N‐methyl‐histamine, phenylethanolamine, phenylpropylamine, tryptamine, dopamine, phenoxylethylamine, noradrenaline, serotonin, and p‐nitro‐phenylethanolamine; inhibitors: Deprenil, Clorgyline, and Lilly 51641 (only the moiety involved in the A–B differentiation is considered). The wave functions needed to calculate the analyzed properties are of ab initio quality, and have been calculated in analogous conformations, all near the energetic minima. Electron densities distributions are qualitatively compared by means of a correlation coefficient defined over the whole space. Otherwise, patterns of the possible zones of electrostatic interactions are described by means of the distances and angles between minima, in order to differentiate MAO‐A and MAO‐B substrates. The results reproduce efficiently the experimental classification and enable us to predict the type of enzymatic action of molecules not yet experimentally classified.
Rayleigh–Schrödinger perturbation theory for many‐electron systems with partitioning of configurations by orders of excitation
Authors: Taylor William J. 
Published: December 2004

AbstractRayleigh–Schrödinger perturbation theory for many‐electron systems has been rederived by an extension of Löwin's partitioning method in which excited configurations are further partitioned by their orders (two equivalent definitions of the order of a configuration are given). The resulting equations show explicitly how first‐, second‐, and third‐order configurations contribute to the first three orders of perturbative corrections to the ground‐state wave function, and the first six orders of corrections to the energy. Because the partitioning is by orders of configurations (rather than level, i.e., single, double, etc., excitations) the formalism is unaffected by the applicability, or nonapplicability, of Brillouin's theorem.
Guild structure of wood‐rotting fungi based on volume and decay stage of coarse woody debris
Authors: Takahashi Kazuo H. , Kagaya Takashi 
Published: December 2004

AbstractWood‐rotting fungi are major organisms exploiting coarse woody debris (CWD) in forests. Here, guild structure of wood‐rotting fungi was investigated in cool temperate (Chichibu) and warm temperate (Chiba) forests in central Japan, based on their occurrence on CWD of different volumes and decay stages. Analysis with the program partitioning around medoids (PAM) recognized two clusters in Chichibu and four in Chiba, and their silhouette coefficients (an index for reliability of clustering) were adequately high, suggesting the existence of non‐random clustering structure. To examine whether the clustering structure observed in this study was based on fungal preference for CWD or discontinuities in the distribution of CWD characteristics (decay stage and volume), null model analyses were made in which all fungal species were randomly redistributed among CWD. Silhouette coefficients based on the null model were reasonably high in both localities, indicating the observed clustering structure was at least partly attributable to the discontinuity in the distribution of CWD characteristics. In addition, the silhouette coefficient of the observed clustering structure was significantly higher than that of the null model in both localities. This result suggests that guild structure was present in the wood‐rotting fungal communities, and the difference in CWD preference among wood‐rotting fungi contributed to the structuralization of the communities.
Effect of Medical Conditions on Improvement in Self‐Reported and Observed Functional Performance of Elders*
Authors: Miller Ram R. , Zhang Yuqing , Silliman Rebecca A. , Hayes Margaret Kelly , G. leveille Suzanne , Murabito Joanne M. , Kiel Douglas , O'connor George T. , Felson David T. 
Published: December 2004

Objectives: To evaluate the effect of nine disabling medical conditions upon recovery from functional limitations by elders.Design: Retrospective analysis of prospective longitudinal cohort.Setting: Community.Participants: Persons aged 65 and older in Framingham Heart Study.Measurements: Change in function in elders from biennial Examinations 18 (1983–85; baseline) through 23 (1994–96). At each examination, subjects reported limitations in heavy household work, walking up and down stairs, walking half a mile, bathing, toileting, and continence. They were also directly observed for performance of transferring in and out of a chair, dressing, walking 50 feet, and carrying a 10‐pound object 10 feet. The prevalence of functional limitations and the incidence of recovery from functional limitation by the subsequent examination for each task were calculated. The effects of congestive heart failure, cognitive impairment, diabetes mellitus, stroke, depressive symptoms, hip fracture, knee pain, claudication, and chronic obstructive pulmonary disease were evaluated. The relationship between the total number of comorbid conditions present (0, 1, 2, 3 or more), the presence of each individual condition at the start of each examination cycle, and the incidence of recovery from functional limitations were examined using generalized estimating equations.Results: One thousand eight hundred twenty‐five subjects were studied at baseline; 1,026 were available 10 years later. Mean age of subjects at baseline was 73.5 (range 61–95); 60.7% were women. The prevalence of functional limitations ranged from 3.1% to 29.8% at biennial Examination 18 and increased to 15.1% to 32.4% at Examination 23. The incidence of recovery ranged from 3.2% to 78.4% depending upon the task and the examination cycle. Increasing disease burden, as measured by the number of comorbidities, was associated with a decreased likelihood of recovery from functional limitations. Diabetes mellitus, stroke, depressive symptoms, hip fracture, and knee pain had the strongest adverse effect upon recovery from functional limitations.Conclusion: In these community‐dwelling elders, recovery from prevalent functional limitations was frequent. Increasing disease burden was associated with a decreased incidence of recovery. Diabetes mellitus, stroke, depressive symptoms, hip fracture, and knee pain had the strongest adverse effect on recovery from functional limitations.
Anthomyzidae (Diptera: Acalyptrata) from Japan and adjacent areas
Authors: Sueyoshi Masahiro , Roháček Jindrich 
Published: December 2004

AbstractAnthomyzidae from Japan are revised and keyed, and additional information on anthomyzid fauna of adjacent areas is provided. Nine species in four genera are recognized: five of the species, Amygdalops nigrinotum, Anthomyza drachma, An. flavosterna, An. trifurca and Ischnomyia triarmigera, are described as new to science, and the other four, An. bellatrix Roháček, An. elbergi Andersson, An. macra Czerny and Stiphrosoma fissum Roháček, are newly recorded from Japan. The genus Ischnomyia Loew is new to the Old World, and the female Anthomyza bellatrix is described for the first time.
Chemical fractionation to characterize changes in sulphur and carbon in soil caused by management
Authors: Bhupinderpal‐Singh  , Hedley M.J. , Saggar S. , Francis G.S. 
Published: December 2004

SummaryClassical chemical fractionation of soil sulphur (S) into HI‐reducible S and carbon‐bonded S does not separate S in soil into fractions that have differing mineralization potentials. Other techniques are needed to separate organic S into more labile and less labile fractions of biological significance, irrespective of their bonding relations. We have sequentially fractionated soil S and carbon (C) into their ionic forms released onto ion‐exchange resins and organic S and C extracted in alkali of increasing concentration. We evaluated the technique on pasture and arable soils that had received various fertilizer and cultivation treatments. Total S and C were greater in the soil of the fertilized pasture than in that of the unfertilized pastures. Continuous arable cropping decreased total soil S and C, whereas restoration to pasture caused an accumulation.Resin, 0.1 m NaOH, 1 m NaOH and residual fractions accounted for between 1–13%, 49–69%, 4–16% and 19–38% of total soil S and between 5–6%, 38–48%, 5–7% and 46–53% of total soil C, respectively. Among different S and C fractions, the size of the 0.1 m NaOH and residual fractions changed more with the change in land use and management. The 0.1 m NaOH fraction had a narrower C:S ratio (50–75:1) than did the residual fraction (96–141:1). The significant degree of change in these two fractions, caused by differences in land management, indicates that they may be useful indicators of change in ‘soil quality’.
HLA‐DPB1*0401 is associated with dominant protection against type 1 diabetes in the general Saudi population and in subjects with a high‐risk DR/DQ haplotype
Authors: Al‐Hussein K. A. , Rama N. R. , Ahmad M. , Rozemuller E. , Tilanus M. G. 
Published: December 2004

SummaryThe human leukocyte antigen (HLA) class II DQB1*0201/0202‐DRB1*04 genotype has been identified as predisposing to type 1 diabetes [insulin‐dependent diabetes mellitus (IDDM)] in the Saudi Arabian population (P = 0.0002; odds ratio = 0.67; 95% confidence interval = 0.009–0.381). In this study, we searched for a factor at the DPB1 locus by analysing DPB1 polymorphism using sequence‐based typing in 86 Saudi IDDM patients and control subjects, all carrying the HLA‐DRB1*04/DQB1*02 haplotype or the known susceptibility allele DQB1*0201/0202. Significant protection was conferred by DPB1*0401, which was observed in 17 of 50 control subjects (55%) and 2 of 36 IDDM patients (5%) with the DQB1*0201/0202 allele (P = 0.0012; odds ratio = 8.75; confidence interval = 1.72–59.70). Our data showing a high frequency of the DPB1*0401 allele even in the presence of the predisposing DQB1*02 allele in healthy subjects may indicate a protective effect of this combination of HLA alleles against type 1 diabetes. This finding supports the hypothesis that protective HLA class II genes can override the risk conferred by HLA‐DQ susceptibility alleles. Further studies using larger cohorts of control subjects and patients should be undertaken to confirm this observation.
Levels of soluble HLA‐G in amniotic fluid are related to the sex of the offspring
Authors: Emmer P. M. , Steegers E. A. P. , Van Lierop M. J. , Loke Y. W. , Van Der Meer A. , Joosten I. 
Published: December 2004

SummaryAlthough HLA‐G is thought to play a modulatory role in the immune system, its function and expression require to be elucidated. We analysed soluble HLA‐G levels in mid‐trimester amniotic fluid (n = 64) from uncomplicated pregnancies. We found a decrease in soluble HLA‐G levels for female offspring as compared to male offspring (P < 0.007). This may be a consequence of the immuno‐modulatory capacity of HLA‐G.
Sorption of iron‐cyanide complexes on goethite
Authors: Rennert T. , Mansfeldt T. 
Published: December 2004

SummaryIron‐cyanide complexes are present in soils on sites of former gas plants and coke ovens. We have studied the sorption of the complexes ferricyanide, [Fe(CN)6]3–, and ferrocyanide, [Fe(CN)6]4–, on goethite in batch experiments, including the effects of concentration, time, ionic strength, pH, and the extent of reversibility. The sorption of ferricyanide showed features of both outer‐sphere and inner‐sphere complexation: its extent decreased with increasing pH; it depended on ionic strength; it was quickly and completely reversible; and it induced a change in surface electric potential. In contrast, sorption of ferrocyanide depended on pH to a lesser extent and was not affected by ionic strength at different pHs. The desorption was slower and incomplete. For ferrocyanide we conclude that sorption involves inner‐sphere complexation and precipitation of a Berlin‐Blue‐like phase on the goethite surface.
Availability and speciation of cadmium added to a calcareous soil under various managements
Authors: Renella G. , Adamo P. , Bianco M. R. , Landi L. , Violante P. , Nannipieri P. 
Published: December 2004

SummaryPotential risks for human health and adverse effects on soil quality caused by accumulation of cadmium (Cd) in soil at concentrations around or exceeding current European Union (EU) permitted limits have long been recognized. We have assessed availability and partitioning of Cd in a Mediterranean calcareous soil under four management regimes. Cadmium was added as a single pulse of CdSO4at the maximum Cd concentration established by the EU for sludge‐amended agricultural soils and concentrations exceeding the mandatory limits. Soils were treated with 0, 3, 10 and 50 mg Cd kg−1soil, incubated moist and analysed at selected times up to 600 days. Cadmium availability and distribution in soil were studied by neutral electrolyte and sequential extractions. During the incubation, the availability of Cd was not strictly dependent on the amount of metal added as the exchangeable fractions were similar shortly after the additions of Cd regardless of its initial concentration. Sequential extractions showed that for concentrations of 3 and 10 mg Cd kg−1soil Cd was evenly distributed among the soil phases, and its mobility was reduced mainly by adsorption on carbonates. At Cd concentrations exceeding 10 mg Cd kg−1soil a residual fraction appeared, perhaps from precipitation of Cd. Most of the Cd was associated with carbonates; land management and organic matter content had no major effects on the Cd distribution among different soil phases. The extraction protocols were effective for studying the fate of Cd in this calcareous soil as almost all of the Cd added was recovered. However, the introduction of a preliminary step with buffered NH4NO3improved the determination of the most labile pools. Availability of Cd in calcareous soils estimated with reference methods appeared to be very small even when its total concentration far exceeded the current EU limits.
Temperature‐dependent energy budget of an Arctic Cladoceran, Daphnia middendorffiana
Authors: Yurista Peder M. 
Published: December 2004

1. Global change models predict the greatest impact in climate to occur in the northern polar region. Change in temperature will alter individual metabolism and has the potential to change community structure to an unknown degree.2. The temperature‐dependent energy budget of Arctic Daphnia middendorffiana was investigated by measuring respiration rates, ingestion rates and assimilation rates. The scope for growth and reproduction was determined and compared with data from the literature for a clone of Daphnia pulicaria collected in the temperate zone.3. A difference was observed between the Arctic species and the temperate zone clone in both temperature tolerance, and the energy available for growth and reproduction at various temperatures. A low availability of energy for growth and reproduction indicated that life history patterns as well as physiological mechanisms are important in allowing D. middendorffiana to exist successfully in Arctic environments.4. The lower available energy for growth compared to Daphnia clones from temperate zones may be detrimental to D. middendorffiana, which might have to compete with species expanding their range under the predicted temperature increase for Arctic regions.
Factors which affect the abundance of an invasive cladoceran, Daphnia lumholtzi, in U.S. reservoirs
Authors: Work Kirsten A. , Gophen Moshe 
Published: December 2004

1. Daphnia lumholtzi is a subtropical, Old World species which is rapidly spreading throughout reservoirs in the southern U.S.A. It was first recorded in Lake Texoma (Oklahoma–Texas) in September 1991.2. Southern U.S. reservoirs typically have strong spatial and temporal gradients in temperature, conductivity, turbidity and in the distribution of organisms. Therefore, the present experiments examined the reproductive and moulting rates, and survival of D. lumholtzi in relation to extremes of food concentration, temperature, conductivity and turbidity.3. Increases in temperature (range = 15–29 °C) and decreases in turbidity (range = 0.6–470 NTU) increased reproductive and moulting rates, whereas food concentration only affected the rate of reproduction, while conductivity had no effects. Survival was affected only by temperature.4. Daphnia lumholtzi tolerates high temperatures (27–30 °C) at which other cladocerans in Lake Texoma disappear. Therefore, D. lumholtzi may exploit resources in midsummer, when there are few potential competitors.
Responses of phytoplankton and epilithon during acidification and early recovery of a lake
Authors: Findlay D. L. , Kasian S. E. M. , Turner M. T. , Stainton M. P. 
Published: December 2004

1. Lake 302S in the Experimental Lakes Area of Canada was acidified from pH 6.7 (1981) to 5.1 (1986). The pH was further reduced to 4.5 in 1987 and held at that level until 1991. From 1992 to 1995, the pH was allowed to increase to a target value of 5.8.2. The response of the phytoplankton community to decreasing pH from 6.0 to 5.1 was similar to that observed in another experimentally acidified lake (223) and in other atmospherically acidified lakes. Acidification affected species diversity of both the phytoplankton and epilithon. Phytoplankton diversity was positively correlated with pH. Epilithic algal diversity was more variable and did not correlate with pH.3. Phytoplankton biomass was enhanced by acidification as the assemblage shifted from a dominance of chrysophytes to large dinoflagellates (Gymnodinium sp. and Peridinium inconspicuum). Epilithon biomass was unaffected, but dominance shifted from filamentous cyanophytes (Lyngbya) to acidophilic diatoms (Tabellaria quadriseptata and Anomoeonis brachysira).4. The only taxon to be similarly affected in both the phytoplankton and epilithon was the cyanobacteria, being significantly reduced below pH 5.1. During early recovery (pH 5.5–5.8), cyanobacteria increased and species present prior to acidification recolonized both habitats.5. In the early stages of recovery, planktonic and benthic assemblages remained more similar to acidified than natural assemblages, but more profound change began at pH > 5.5.