bluuebunny/crossref_metadata_2025_split huggingface dataset:
SO phonons in spherical nanostructured quantum dots
Authors: Comas F. , Odriazola A. 
Published: February 2005

AbstractA theoretical model for a nanostructured spherical Quantum Dot (QD) is considered, where to a core sphere of semiconductor “1” it is added a concentric spherical layer of semiconductor “2”, while this structure is assumed as imbedded in an infinite medium made of semiconductor “1”. Using a long‐wave continuum approach, the so‐called dielectric continuum approach, we study the surface optical (SO) phonons associated with the two spherical interfaces of the nanostructure. The possible SO phonon frequencies are analyzed as a function of both the sizes of the structure and the angular momentum quantum number l = 1, 2, …. We also calculate the electric potential provided by the SO phonons and derive an analytical expression for the electron–phonon interaction Hamiltonian. Different possible cases for semiconductors “1” and “2” are discussed, comparisons with previously published works on similar subjects are done and the experimental techniques allowing the possible determination of this kind of phonons are invoked. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of experimental noise on densities reconstructed from line projections
Authors: Samsel‐Czekała M. , Boguszewicz Ł. 
Published: February 2005

AbstractThe influence of experimental noise on densities ρ(p) reconstructed by the Cormack method from their line projections, e.g. 2D ACAR spectra, is investigated. Simulations of statistical noise are performed for various sets of 2D spectra for two model ρ(p) having the cubic symmetry. For the reconstructed densities propagation of the statistical error in terms of standard deviations, σ[ρ(p)], is estimated. We observe that the distribution of σ[ρ(p)] has its extremes along the main symmetry directions and also a tendency to accumulate for small p. Moreover, the more density components, ρn(p), have to be taken to description of ρ(p) the less anisotropic is the distribution of σ[ρ(p)]. Additionally, the error generated by the reconstruction method itself is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio QM/MM study of excited state electron transfer between pyrene and 4,4′‐bis(dimethylamino)‐diphenylmethane with different solvent systems: Role of hydrogen bonding within solvent molecules
Authors: Sen Kakali , Basu Samita , Bhattacharyya Dhananjay 
Published: February 2005

AbstractThe exciplex is a charge transfer species formed in the process of electron transfer between an electron donor and an electron acceptor and hence is very sensitive to solvent polarity. In order to understand the role of solvent in exciplex formation between pyrene (PY) and 4,4′‐bis(dimethylamino)diphenylmethane (DMDPM), we used two types of solvent approximations: an implicit solvent model and an explicit solvent model. The difference in energies between the excited and the meta‐stable Frank–Condon state (ΔE) of the structures were assumed to correspond to the emission maximum of the exciplex in different solvents. The ΔE values show the trend of stabilization of the exciplex with an increase in solvent polarity. This trend in stabilization is substantially more prominent in the explicit solvent model than that with the implicit solvent model. The ΔE value obtained in methanol reflects equal stabilization compared to that in a more polar solvent, N,N‐dimethylformamide. This extra stabilization of the exciplex may be explained on the basis of the H‐bonding capability of the protic solvent, methanol. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Jahn–Teller theorem and nodal points of wave functions
Authors: Pupyshev Vladimir I. 
Published: February 2005

AbstractThe split of electronic energy levels for a degenerate state near the symmetrical geometry configuration is considered. It is demonstrated that this effect is closely connected with the nodal properties of the symmetry‐adapted orbitals. Simple proof of the Jahn–Teller theorem is proposed based on analysis of the “radial” vibrations (Zhilinskii–Stepanov theorem). Examples of “violations” of the Jahn–Teller theorem are considered. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Properties of methanol bound to a defect of zeolitic structure
Authors: Stepanov Nikolai F. , Kubasov Alexei A. , Tikhii Yaroslav V. 
Published: February 2005

AbstractDifferent mechanisms of Brønsted acidity formation upon the adsorption of a methanol molecule on a model Lewis acid site within zeolitic structure are evaluated by means of density functional theory in cluster approximation. The properties of the Brønsted acid sites formed are examined through studying their interaction with such probe molecules as methanol, ammonia, and ethylene. The results obtained are used to comment on a possible role of Lewis acid sites in methanol reactions catalyzed by zeolites. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Resonance Raman and hyper‐Raman spectroscopy of organic chromophores for second‐order nonlinear optics
Authors: Myers Kelley Anne 
Published: February 2005

AbstractTwo‐photon resonant hyper‐Raman spectroscopy from large molecules in solution is discussed as a method for probing excited electronic states that are both one‐ and two‐photon allowed. A number of electron donor–acceptor substituted conjugated organic molecules that have large first hyperpolarizabilities (β) have recently been shown to give strong resonance hyper‐Raman (RHR) spectra in solution. The quantum mechanical formulation of RHR scattering is reviewed, and practical approaches to calculating RHR spectra and excitation profiles are proposed by reference to methods already developed for simulating linear resonance Raman spectra and profiles. The potential benefits of a close interplay between experiments, empirical simulations, and electronic structure calculations of ground‐state and excited‐state properties are emphasized. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Infrared linear dichroism in stretched films: Quantum mechanical approach within the polarizable continuum model
Authors: Cappelli Chiara , Corni Stefano , Mennucci Benedetta , Tomasi Jacopo , Cammi Roberto 
Published: February 2005

AbstractIn this work we discuss how environmental effects on vibrational transition moment directions for molecules dispersed in stretched films can be accounted for via the integral equation formalism polarizable continuum model (IEFPCM). In particular, effects related to the matrix polarization induced by the probing field (cavity field terms) are taken into account. Calculations are performed for three DNA‐related molecules (9‐methyladenine, 7‐methyladenine, and 2‐amino‐9‐methylpurine) for which infrared linear dichroism (IR LD) has been measured experimentally. By combining experimental data and calculations, different parameters of the film (Saupe order parameters and orientational axis direction) can be obtained and used to give “experimental” estimates of transition moment directions. The results show the importance of accounting for the environment surrounding the molecule in transition moment calculations. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Design and performance of a sheathless capillary electrophoresis/mass spectrometry interface by combining fused‐silica capillaries with gold‐coated nanoelectrospray tips
Authors: Kele Zoltán , Ferenc Györgyi , Klement Éva , Tóth Gábor K. , Janáky Tamás 
Published: February 2005

AbstractA simple sheathless capillary electrophoresis (CE)/mass spectrometry (MS) interface was constructed by combining widely used nanospray needles with fused‐silica capillaries and it was successfully applied for the separation of peptides. The end of the CE capillary was pulled to a taper, etched and then fitted into the metal‐coated nanospray borosilicate capillary. The nanospray needle can be used for several CE runs, but it can be easily and rapidly changed in the case of accidental breakage or evaporation of the coating. A fast capillary electrochromatographic method was also developed for MS analysis of peptides containing numerous basic amino acids. Copyright © 2005 John Wiley & Sons, Ltd.
Regression models for the analysis of longitudinal Gaussian data from multiple sources
Authors: O'Brien Liam M. , Fitzmaurice Garrett M. 
Published: February 2005

AbstractWe present a regression model for the joint analysis of longitudinal multiple source Gaussian data. Longitudinal multiple source data arise when repeated measurements are taken from two or more sources, and each source provides a measure of the same underlying variable and on the same scale. This type of data generally produces a relatively large number of observations per subject; thus estimation of an unstructured covariance matrix often may not be possible. We consider two methods by which parsimonious models for the covariance can be obtained for longitudinal multiple source data. The methods are illustrated with an example of multiple informant data arising from a longitudinal interventional trial in psychiatry. Copyright © 2005 John Wiley & Sons, Ltd.
Familiarity may buffer the adverse effects of relocation on marmosets (Callithrix kuhlii): Preliminary evidence
Authors: Schaffner C.M. , Smith T.E. 
Published: February 2005

AbstractThe relocation of exotic species is increasingly crucial for the proper management of captive populations. We investigated the effects of relocation on urinary cortisol levels and proximity behavior in four Wied's marmosets (Callithrix kuhlii). Two of the relocated marmosets constituted a well‐established pair, whereas two (the newly established pair) were introduced when they arrived at the new facility. Four adult females served as control animals in which we assessed cortisol response to pair formation in the absence of relocation. Urinary cortisol in the relocated subjects was monitored for 4 weeks before and 12 weeks after the relocation event. Urinary cortisol in the control subjects was monitored for 4 weeks before and 8 weeks after the pairs were formed. Proximity was monitored in the relocated subjects for 12 weeks following the move. After the animals were relocated, the newly established pair had significantly elevated levels of urinary cortisol compared to the well‐established pair and control females, which lasted at least 8 weeks. For both pairs, cortisol levels decreased over time across the 12 weeks following the relocation event. The members of the well‐established pair were in contact with each other for 65% of the intervals sampled in the 2 weeks immediately following relocation, compared to only 12% in the newly established pair. These preliminary findings suggest that relocation is associated with significant adverse physiological and behavioral changes that may be ameliorated by the presence of a highly familiar social partner. The study highlights the importance of future research in this field. Zoo Biol 24:93–100, 2005. © 2005 Wiley‐Liss, Inc.
Predicting reproduction in captive sea otters (Enhydra lutris)
Authors: Da Silva I.M. , Larson S. 
Published: February 2005

AbstractThe sea otter (Enhydra lutris) is a threatened species. It is also a popular exhibit animal in many zoos and aquariums worldwide. Unfortunately, sea otters reproduce successfully in only a small number of facilities. Pregnancies vary in duration, and are thought to involve a delayed implantation of about 2–3 months, followed by an implanted phase of 4–5 months. In this study we attempted to identify estrus and pregnancy states, and predict the date of birth in one female sea otter (Mali) housed at the Lisbon Oceanarium. We used different techniques to evaluate her reproductive status, including monitoring behavior to determine estrus, assessing weight changes to determine pregnancy and parturition date, and analyzing fecal hormone samples to determine estrus, pregnancy, and parturition date. During this study, Mali became pregnant four times. Her gestational length varied between 188–255 days. Weight increases >29 kg or 15% above baseline weight suggested pregnancy, and parturition was estimated to occur approximately 3 months thereafter. Fecal hormone (progestagens and estrogen) metabolite data gathered during two of her pregnancies showed that Mali's delayed implantation phase of pregnancy lasted 43–109 days (a typical duration in other sea otters is 100–110 days). Mali's implanted phase lasted a relatively long time (140–145 days compared to an average of 117 days in other sea otters). The combination of the three measurements was a powerful tool that enabled us to determine pregnancy and anticipate the arrival of a new sea otter pup. Zoo Biol 24:73–81, 2005. © 2005 Wiley‐Liss, Inc.
Energy and mineral nutrition and water intake in the captive Indian rhinoceros (Rhinoceros unicornis)
Authors: Clauss Marcus , Polster Carmen , Kienzle Ellen , Wiesner Henning , Baumgartner Katrin , von Houwald Friedericke , Streich W. Juergen , Dierenfeld Ellen 
Published: February 2005

AbstractIn the captive Indian rhinoceros (Rhinoceros unicornis), two disease complexes with a high incidence—chronic foot problems and uterine leiomyomas—may be linked to excess body weight (BW). In this study, intake and digestion trials were conducted (by means of 7‐day weigh‐backs, and 5‐day total fecal collections, respectively) with 11 Indian rhinoceroses at four zoological institutions in Europe and the United States to quantify energy and mineral nutrition on conventional or roughage‐only diets. Diets comprising a variety of forages (grass hay only, a combination of grass hay and grass silage, straw, or a mixture of grass and legume hay) were offered as the roughage source, along with various concentrates, produce, and supplements. Water intake was quantified, and urine samples were obtained opportunistically. The animals consumed 0.5–1.1% of their BW in dry matter (DM) daily, with calculated digestible energy (DE, in megajoules MJ) values ranging from 0.27 to 0.99 MJ DE/kg BW0.75/day compared to an estimated requirement of 0.49–0.66 MJ DE/kg BW0.75/day. Seven of 11 rhinos (64%) fed restricted levels of concentrate plus forage consumed DE in excess of this estimate. Even on roughage‐only diets, some individuals consumed energy well above the presumed metabolic requirements. Hence, restriction of both concentrates and roughage may be important for weight management in this species. Water intake ranged from 30 to 49 mL/kg BW daily (3.4–5.2 L/kg ingested DM), similar to values that have been reported for domestic equids. Excretion amounts and patterns also resembled those found in horses. Endogenous fecal losses measured for Ca, P, Cu, Fe, and Zn indicate that the maintenance requirements of these minerals should be met in Indian rhinoceroses by diets that meet recommendations for domestic horses. It is particularly important to evaluate dietary adequacy in mineral nutrition in this species in concert with the need for restricted energy intake, especially with regard to the hypothetical involvement of a low Zn supply in chronic foot problems. Zoo Biol 24:1–14, 2005. © 2005 Wiley‐Liss, Inc.
Fecal corticoid monitoring in whooping cranes (Grus americana) undergoing reintroduction
Authors: Hartup Barry K. , Olsen Glenn H. , Czekala Nancy M. 
Published: February 2005

AbstractWe used radioimmunoassay to determine fecal corticoid concentrations and assess potential stress in 10 endangered whooping cranes (Grus americana) undergoing reintroduction to the wild. Fecal samples were collected shortly after hatching at a captive facility in Maryland, during field training in Wisconsin, and throughout a human‐led migration to Florida. After a 14‐day decline following hatching, fecal corticoid concentrations stabilized at baseline levels for the duration of the captive period, despite exposure to potentially stressful stimuli. Shipment of the cranes to the field training site was correlated with an eight‐ to 34‐fold increase in fecal corticoid concentrations, which returned to baseline levels within 1 week. Increases were positively correlated with age but not body weight at the time of shipping. Fecal corticoid concentrations during the training period increased slightly and exhibited greater variation than levels observed at the captive facility, but were well within expected norms based on previous studies. Fecal corticoid concentrations increased twofold following premigration physical examinations and placement of radiotransmitters, and persisted for up to 4 days before they returned to baseline levels. Though fecal corticoid concentrations and variation during the migration period were similar to training levels, there was an overall decline in fecal corticoid concentrations during the artificial migration. Acute stressors, such as capture, restraint, and severe storms, were associated with stress responses by the cranes that varied in accordance with lasting physical or psychological stimuli. The overall reintroduction process of costume‐rearing, ultralight aircraft habituation, training, and artificial migration was not associated with elevations in fecal corticoid concentrations suggestive of chronic stress. Zoo Biol 24:15–28, 2005. © 2005 Wiley‐Liss, Inc.
Reproduction, Growth and Development in Captive Beluga (Delphinapterus leucas)
Authors: Robeck Todd R. , Monfort Steven L. , Calle Paul P. , Dunn J. Lawrence , Jensen Eric , Boehm Jeffrey R. , Young Skip , Clark Steven T. 
Published: February 2005

AbstractRecent success propagating captive beluga has resulted from combined efforts by North American zoos and aquariums to manage disparate collections as a single population. This success has provided a tremendous opportunity to increase our understanding of beluga reproductive biology. Blood samples were collected on a weekly to biweekly basis from 23 female and 12 male beluga, ranging in age from 2–15 years, for analysis of serum progesterone (P) and testosterone (T), respectively. Peri‐parturient observational data, including food intake, duration and signs of labor, and nursing patterns were collected from 15 days prepartum to 30 days postpartum during 21 births. Total body lengths and weights were collected from 10 captive‐born beluga. For female beluga, the mean (±SD) age, body length, and weight at first conceptions were 9.1±2.8 years, 318.0±9.1 cm, and 519±84 kg. Thirty‐five luteal phases and 13 conceptions were detected from January–June, and 70% of luteal phases and 80% conceptions occurred from March–May. The mean luteal phase and total estrous cycle lengths were 30.0±6.5 days and 48.0±4.6 days, respectively. For male beluga, the mean age that males sired their first calf was 13.3±2.6 years. Compared to younger males (<8 years of age, 0.95 ng/ml), levels of T secretion in older males (>8 years of age, 5.0 ng/ml) were elevated significantly only during the interval from January–April. Highest T concentrations (6.2±4.9 ng/ml) were recorded from January–March, whereas nadir concentrations (1.1±1.0 ng/ml) were detected from August–September. The mean gestation length was 475.0±20.4 days (n=9). For parturition, the mean time from the first appearance of fluke or rostrum to delivery, delivery to placental passage, and delivery to nursing were 4.4±2.9 hr, 7.6±1.8 hr, and 43±45 hr, respectively. All cows had decreased food intake on the day of delivery, with 44% having zero intake. Peak 24‐hr nursing activity occurred 3.9±2.7 days post‐partum. Growth (i.e., body weight and length) as a function of age were well described by the Gompertz model (r2=0.91, 0.93). Based on the model, growth in body weight and length were significantly greater in males compared to females. Predicted birth weight (88.9 kg) was similar for both sexes, however, and male calves were predicted to be shorter (154.3 cm) than female calves (160.7 cm). The results provide the first descriptions of captive beluga reproductive physiology, including endocrinology, peri‐parturient behavior, growth, and reproductive maturity. This knowledge is important for helping to maintain genetically diverse, self‐sustaining populations of captive beluga whales. Zoo Biol 24:29–49, 2005. © 2005 Wiley‐Liss, Inc.
Mineral concentrations in serum/plasma and liver tissue of captive and free‐ranging Rhinoceros species
Authors: Dierenfeld Ellen S. , Atkinson Shirley , Craig A. Morrie , Walker Karen C. , Streich W. Jürgen , Clauss Marcus 
Published: February 2005

AbstractMineral implications in health issues of captive rhinos have received much attention lately. This study was undertaken to establish reference values for the mineral status of rhinos. Serum/plasma samples of free‐ranging black (Diceros bicornis) and white (Ceratotherium simum) rhinos and of captive black, white, Indian (Rhinoceros unicornis), and Sumatran (Dicerorhinus sumatrensis) rhinos, as well as liver tissue samples of captive black, white, and Indian rhinos were analyzed for mineral content. Circulating mineral levels of free‐ranging animals were subject to variation according to region. In free‐ranging animals, high molybdenum (Mo) values compared to horse normals were striking. Captive animals displayed even higher circulating Mo concentrations. The significance of iron (Fe) overload in captive specimens of the browsing rhinos (black and Sumatran) was confirmed. Hepatic Fe levels increased in blacks with age. Although this Fe overload is suspected to be linked with diets, the data indicate that this is not due solely to an excessive dietary Fe supply. Whereas the grazing species (white and Indian) had high liver copper (Cu) levels, the browsing species had low to marginal liver Cu concentrations. Liver concentrations of K, Mg, Co, and Mo increased with age in captive black rhinos. Additional findings include high circulating Se levels in all rhino species. Future research should be directed at investigating factors leading to high Fe levels, and at investigating Cu metabolism in captive rhinoceros species. Zoo Biol 24:51–72, 2005. © 2005 Wiley‐Liss, Inc.
Surgery for Esophageal Cancer after Concomitant Radiochemotherapy: Oncologic and Functional Results
Authors: Plaisant Nicolas , Senesse Pierre , Azria David , Lemanski Claire , Ychou Marc , Quenet Francois , Saint‐Aubert Bernard , Rouanet Philippe 
Published: February 2005

AbstractThe aim of this study was to evaluate the results of surgery after preoperative radiochemotherapy (PRCT) for esophageal cancer. This retrospective study included 88 patients scan between 1992 and 2000. The median follow‐up was 55.7 months (3.3‐104.1 months). Surgical mortality was 15.9%. Multivariate analysis found that the following were risk factors for surgical mortality: γ‐glutamyltransferase level > 75 UI/ml (p= 0.007), weight loss = 10% (p= 0.05), and digestive toxicity World Health Organization grade III or IV during PRCT (p= 0.019). The median overall survival was 24.9 months. The 5‐year overall survival (OS) and disease‐free survival (DFS) were, respectively, 33.1% and 33.2%. Complete responder patients had a 71.8% 5‐year OS (p= 0.01) and a 71.8% 5‐year DFS (p= 0.009). The rate of recurrence was 37.5%. Multivariate analysis found that female gender (p= 0.03), weight loss = 10% (p= 0.03), preoperative computed tomography scan bronchial contact (p= 0.01), and N+ status (pN+) at pathology examination (p= 0.0001) were predictors of poor oncologic results. Patients with high preoperative risk of surgical mortality need to be selected for intensive perioperative management. In association with surgery, PRCT improves the local control, DFS, and OS of responder patients. Morphologic evaluation for staging esophageal cancer in predicting the pathologic response after PRCT is poor or controversial. Only surgical resection can provide accurate prognostic information for staging esophageal cancer and improving local control.