bluuebunny/crossref_metadata_2025_split huggingface dataset:
First principles total energy calculations of the adsorption of single Cl2 and Br2 molecules on the Si(001)‐c(2 × 4) surface
Authors: Takeuchi Noboru 
Published: October 2003

AbstractWe have performed first principles total energy calculations to investigate the adsorption of Cl2 and Br2 molecules on the Si(001)‐c(2 × 4) surface. First of all, our results indicate that the adsorption of Cl2 and Br2 as molecules is not energetically favorable. Instead, Cl2 (Br2) dissociates into two Cl (Br) subunits. The most stable geometry was achieved when each Cl (Br) subunit is bonded to a Si atom of the same Si dimer along the dangling bonds. Three other geometries were considered in our study: the first one corresponds to adsorption of the two subunits on Si dimer sites in adjacent silicon dimer rows. The second corresponds to adsorption of the two Cl (Br) subunits along dangling bonds of two consecutive dimers of the same Si dimer row, with the two Cl(Br) atoms in the same side of the Si dimer row. The third one is similar to the second, but the ad‐atoms are now in a staggered arrangement, occupying sites in opposite sides of the Si dimer row. These are adsorption configurations that have been observed experimentally for Cl2 on Si(001). Our results indicate that energetics and atomic geometries are similar for Cl2 and Br2. We have also calculated energy barriers for the ad‐atom to move along and across the Si dimer rows. It is found that the barriers for Br are smaller than the barriers for Cl. This result can explain the differences observed in the adsorption of Cl2 and Br2 molecules.
On crystal‐field parametrization in a uniformly strained crystal lattice
Authors: Mulak J. 
Published: October 2003

AbstractThe general consequences of uniform strain of a crystal lattice or coordination complex in phenomenological parametrization of the crystal‐field potential are considered. The analysis is based on the three‐dimensional derivatives of intrinsic crystal‐field parameters within the superposition model of the crystal‐field potential. The problem of the lowest possible symmetry of a uniformly strained crystal is discussed. Some limitations of the admissible deformations arise from the invariance of symmetry planes and inversion centre with respect to uniform strains. For any uniform strain, the crystal‐field potentials that are expressible by q‐even terms only can never be reduced to potentials requiring q‐odd terms. Therefore, their maximal symmetry lowering must terminate at a monoclinic point symmetry group. However, for a general uniform strain, some real derivatives of parameters of orthorhombic character IIk2 for 2 ≤ k ≤ 6, apart from the axial ones Bk0 for 1 ≤ k≤ 6, can always occur. As a consequence, the decrease in symmetry for point groups that are characterized by an odd‐fold axis (q‐odd) and lack of any symmetry plane is unrestricted down to the triclinic systems. However, some incomplete sets of crystal‐field parameters compared with those predicted by group theory are needed. Uniform strains in crystals occur generally as a response to external stress used in pressure studies. The calculation method of the relative dimensionless changes of dBkq/Bkq as a function of pressure using the stress–strain data (elastic stiffness moduli) is given. Such successful calculations for the Pr3+ : LiYF4 system based only on the crystallographic data and the tk exponents (in the distance dependence of Bkq) are presented as an example. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxygen diffusion in YSZ single crystals at relatively low temperatures
Authors: Röwer Ralf , Knöner Gregor , Reimann Klaus , Schaefer Hans‐Eckhardt , Södervall Ulf 
Published: October 2003

AbstractThe 18O tracer experiments were carried out on two cubic YSZ single crystals at temperatures of TD = 423 K and TD = 473 K. The diffusion profiles were determined by the SIMS technique. The diffusion coefficients, the surface exchange coefficients and the activation enthalpy are discussed together with earlier data at higher temperatures. The present oxygen diffusion data demonstrate that the same diffusion process is operating over a wide temperature range. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐frequency EPR studyof Cr3+ doped lead titanate (PbTiO3) nanopowders
Authors: Erdem Emre , Böttcher Rolf , Semmelhack Hans‐Christoph , Gläsel Hans‐Jürgen , Hartmann Eberhard 
Published: October 2003

AbstractIn our multi‐frequency EPR study of Cr3+ doped PbTiO3 nanopowder samples with varying mean particle size, three paramagnetic Cr3+ centres (C1, C2, C3) with different axial fine structure (FS) parameters are identified, with one of them (C1) being compatible with former literature measurements on bulk and ceramics samples carried out in the X band. The superposition model by Newman and Urban was applied to translate the FS data into local displacements inside the distorted oxygen octahedra of the PbTiO3 lattice. When going to nanopowder samples with mean particle size below a critical value, other than the centre C1 are no longer detectable. Instead, a new one (C4) appears, testifying a pronounced size effect. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Schizophrenia: Putting context in context
Authors: Park Sohee , Lee Junghee , Folley Bradley , Kim Jejoong 
Published: October 2003

AbstractAlthough context-processing deficits may be core features of schizophrenia, context remains a poorly defined concept. To test Phillips & Silverstein's model, we need to operationalize context more precisely. We offer several useful ways of framing context and discuss enhancing or facilitating schizophrenic patients' performance under different contextual situations. Furthermore, creativity may be a byproduct of cognitive uncoordination.
Phenomenology, context, and self-experience in schizophrenia
Authors: Sass Louis A. , Uhlhaas Peter J. 
Published: October 2003

AbstractImpairments in cognitive coordination in schizophrenia are supported by phenomenological data that suggest deficits in the processing of visual context. Although the target article is sympathetic to such a phenomenological perspective, we argue that the relevance of phenomenological data for a wider understanding of consciousness in schizophrenia is not sufficiently addressed by the authors.
Combating fuzziness with computational modeling
Authors: Talamini L. M. , Meeter M. , Murre J. M. J. 
Published: October 2003

AbstractPhillips & Silverstein's ambitious link between receptor abnormalities and the symptoms of schizophrenia involves a certain amount of fuzziness: No detailed mechanism is suggested through which the proposed abnormality would lead to psychological traits. We propose that detailed simulation of brain regions, using model neural networks, can aid in understanding the relation between biological abnormality and psychological dysfunction in schizophrenia.
Local-pooled-error test for identifying differentially expressed genes with a small number of replicated microarrays
Authors: Jain Nitin , Thatte Jayant , Braciale Thomas , Ley Klaus , O'Connell Michael , Lee Jae K. 
Published: October 2003

Abstract
Motivation: In microarray studies gene discovery based on fold-change values is often misleading because error variability for each gene is heterogeneous under different biological conditions and intensity ranges. Several statistical testing methods for differential gene expression have been suggested, but some of these approaches are underpowered and result in high false positive rates because within-gene variance estimates are based on a small number of replicated arrays.
Results: We propose to use local-pooled-error (LPE) estimates and robust statistical tests for evaluating significance of each gene's differential expression. Our LPE estimation is based on pooling errors within genes and between replicate arrays for genes in which expression values are similar. We have applied our LPE method to compare gene expression in naïve and activated CD8+ T-cells. Our results show that the LPE method effectively identifies significant differential-expression patterns with a small number of replicated arrays.
Availability: The methodology is implemented with S-PLUS and R functions available at http://hesweb1.med.virginia.edu/bioinformatics
Synchronization Phenomena in an Array of Population Dynamic Systems
Authors: Postnov D. E. , Balanov A. G. , Mosekilde E. 
Published: October 2003

The paper applies continuation methods to examine fundFigureamental features of the complex dynamics that can arise in a cascaded system of population dynamic models. The individual model describes a bacterial population interacting with a population of viruses that attack the cells and exploit their reproductive system for their own replication. Coupling between the subsystems is brought about through a unidirectional flow of primary resources. In this way the individual subsystem is modulated by the varying nutrient concentration in the overflow from the upstream habitat. Synchronization of a single subsystem to an external periodic forcing exhibits an unusual bifurcation structure with global bifurcations appearing already at the lowest forcing amplitudes. This peculiarity is also observed for autonomous systems of two and three coupled habitats. Finally, local and global synchronization phenomena are investigated for a chain of 20 coupled population pools.
Song as a signal to negotiate a sexual conflict?
Authors: Verhulst Simon 
Published: October 2003

AbstractSexual conflict occurs when the optimal solution regarding e.g. a life history trait differs between co-operating individuals of different sex. When deciding a conflict is not instantaneous, some form of negotiation can be expected to evolve. In great tits, Parus major, a sexual conflict exists over the number of clutches that are reared, because the fitness costs of a second clutch are greater for females. A conflict is also likely to exist over investment in the first brood - each parent benefiting from a greater investment by the partner. Male great tits sing when rearing the first brood, and if acoustic signals play a role in the negotiation of a sexual conflict, a positive association between male song rate and maternal investment is predicted. In agreement with this hypothesis, maternal effort (in kJ/day) relative to paternal effort was positively correlated with male song rate. Furthermore, females were more likely to start a second clutch when their male had a high song rate, and high song rate was associated with shorter inter-clutch intervals. Song rate was higher when brood size was experimentally reduced and, independent of brood size manipulation, males with high song rate produced higher quality fledglings. These results indicate that song rate reflects the males' state, suggesting it may function as a handicap signal. Although song rate seems too low (<4% of time) for honesty to be maintained by production costs alone, signalling costs may be amplified by the fact that song appears restricted to the time when the male and female are both near the nest. To achieve a high song rate, the male may have to spend a large amount of time near the nest, thereby seriously restricting time available for other activities.
Antineoplastic Effects of Partially HLA-Matched Irradiated Blood Mononuclear Cells in Patients With Renal Cell Carcinoma
Authors: Strair Roger K. , Schaar Dale , Medina Daniel , Todd Mary B. , Aisner Joseph , DiPaola Robert S. , Manago Jacqueline , Knox Beth , Jenkinson Amanda , Senzon Rachelle , Baker Christina , Dudek Liesel , Ciardella Marie , Kuriyan Mercy , Rubin Arnold , Lattime Edmund C. 
Published: October 2003

Purpose: Vaccines, cytokines, and other biologic-based therapies are being developed as antineoplastic agents. Many of these agents are designed to induce an autologous immune response directed against the malignancy. In contrast, hematopoietic stem-cell transplantation is being developed as a form of allogeneic immunotherapy. This study tests the tolerance and antineoplastic activity of sequential infusions of partially HLA-matched allogeneic blood mononuclear cells (obtained from relatives) when administered outside of the context of a hematopoietic stem-cell transplantation. The cells are irradiated to prevent graft-versus-host disease. Patients and Methods: Fifteen patients with relapsed or refractory malignancies for which no standard therapy was available were enrolled onto a clinical trial designed to assess the tolerability and antineoplastic effects of irradiated partially HLA-matched blood mononuclear cells obtained from relatives. Results: There was disease regression in three patients with metastatic renal cell carcinoma during treatment. There was disease progression in six patients with metastatic renal cell carcinoma and two patients with metastatic melanoma during treatment. There was no change in disease state in several other patients. Conclusion: Irradiated allogeneic blood mononuclear cells administered outside the context of hematopoietic stem-cell transplantation may induce disease responses in patients with relapsed or refractory malignancies. Transfusion of irradiated allogeneic blood mononuclear cells should be developed further as a novel therapeutic antineoplastic approach.
A Phase I Study of Irinotecan As a 3-Week Schedule in Children With Refractory or Recurrent Solid Tumors
Authors: Vassal Gilles , Doz Francois , Frappaz Didier , Imadalou Karima , Sicard Evelyne , Santos Alexandre , O’Quigley John , Germa Caroline , Risse Marie-Laure , Mignard Dominique , Pein Francois 
Published: October 2003

Purpose: A phase I study was performed to determine the maximum-tolerated dose (MTD) and safety profile of irinotecan (CPT-11) administered as a single intravenous infusion every 3 weeks in children with recurrent or refractory solid tumors. Patients and Methods: Eighty-one patients were enrolled, including 48 less heavily, and 33 heavily pretreated patients (cranial irradiation and/or high-dose chemotherapy). Children received CPT-11 as a 120-minute infusion at doses ranging from 200 to 720 mg/m2. The dose-limiting toxicities (DLT) on first cycle were determined in both cohorts. Results: One hundred twenty-two cycles and 81 cycles were administered in less heavily, and heavily pretreated patients, respectively. The primary DLT was delayed diarrhea in less heavily pretreated patients, and neutropenia in heavily pretreated patients. MTD was 600 mg/m2 in both cohorts. Grade 3 to 4 neutropenia occurred in 33% and 38% of cycles in less heavily, and heavily pretreated patients, respectively. Grade 3 to 4 nonhematologic toxicities included nausea/vomiting (7% and 4% of cycles in less heavily, and heavily pretreated patients, respectively), asthenia (7% and 4% of cycles, respectively), and delayed diarrhea (6% and 2.5% of cycles, respectively). Four partial responses at 600 mg/m2 (high-grade glioma, neuroblastoma, medulloblastoma, and rhabdomyosarcoma) and 21 minor responses and stable diseases were observed. Pharmacokinetic analysis of CPT-11 and SN-38 was performed in 77 patients. The mean ± standard deviation (SD) CPT-11 plasma clearance was 20.7 ± 9.5 L/h/m2 (range, 5 to 54). The mean ± SD SN-38 metabolic ratio was 1.5% ± 1.1% (range, 0.15% to 5.55%). Conclusion: The recommended phase II dose of CPT-11 in a 3-week schedule is 600 mg/m2 in less heavily, and heavily pretreated children with solid tumors.
Long-Term Psychological Impact of Carrying a BRCA1/2 Mutation and Prophylactic Surgery: A 5-Year Follow-Up Study
Authors: van Oostrom Iris , Meijers-Heijboer Hanne , Lodder Litanja N. , Duivenvoorden Hugo J. , van Gool Arthur R. , Seynaeve Caroline , van der Meer Conny A. , Klijn Jan G.M. , van Geel Bert N. , Burger Curt W. , Wladimiroff Juriy W. , Tibben Aad 
Published: October 2003

Purpose: To explore long-term psychosocial consequences of carrying a BRCA1/2 mutation and to identify possible risk factors for long-term psychological distress. Patients and Methods: Five years after genetic test disclosure, 65 female participants (23 carriers, 42 noncarriers) of our psychological follow-up study completed a questionnaire and 51 participants were interviewed. We assessed general and hereditary cancer-related distress, risk perception, openness to discuss the test result with relatives, body image and sexual functioning. Results: Carriers did not differ from noncarriers on several distress measures and both groups showed a significant increase in anxiety and depression from 1 to 5 years follow-up. Carriers having undergone prophylactic surgery (21 of 23 carriers) had a less favorable body image than noncarriers and 70% reported changes in the sexual relationship. A major psychological benefit of prophylactic surgery was a reduction in the fear of developing cancer. Predictors of long-term distress were hereditary cancer-related distress at blood sampling, having young children, and having lost a relative to breast/ovarian cancer. Long-term distress was also associated with less open communication about the test result within the family, changes in relationships with relatives, doubting about the validity of the test result, and higher risk perception. Conclusion: Our findings support the emerging consensus that genetic predisposition testing for BRCA1/2 does not pose major mental health risks, but our findings also show that the impact of prophylactic surgery on aspects such as body image and sexuality should not be underestimated, and that some women are at risk for high distress, and as a result, need more attentive care.
Energy budget of hepatocytes from Antarctic fish (Pachycara brachycephalumandLepidonotothen kempi) as a function of ambient CO2: pH-dependent limitations of cellular protein biosynthesis?
Authors: Langenbuch M. , Pörtner H. O. 
Published: October 2003

SUMMARYScenarios of rising CO2 concentration in surface waters due to atmospheric accumulation of anthropogenic CO2, or in the deep sea due to anticipated industrial dumping of CO2, suggest that hypercapnia (elevated partial pressure of CO2) will become a general stress factor in aquatic environments, with largely unknown effects on species survival and well being, especially in cold and deep waters. For an analysis of CO2 effects at the cellular level, isolated hepatocytes were prepared from two representatives of the Antarctic fish fauna, Pachycara brachycephalum and Lepidonotothen kempi. Correlated changes in energy and protein metabolism were investigated by determining the rates of oxygen consumption at various levels of PCO2, of intra- and extracellular pH, and after inhibition of protein synthesis by cycloheximide. A decrease in extracellular pH (pHe) from control levels (pHe 7.90) to pHe 6.50 caused a reduction in aerobic metabolic rate of 34-37% under both normocapnic and hypercapnic conditions. Concomitantly, protein biosynthesis was inhibited by about 80%under conditions of severe acidosis in hepatocytes from both species. A parallel drop in intracellular pH probably mediates this effect. In conclusion, the present data indicate that elevated PCO2 may limit the functional integrity of the liver due to a pronounced depression in protein anabolism. This process may contribute to the limits of whole-animal tolerance to raised CO2levels.
Effect of coronary perfusion on the basal performance, volume loading and oxygen consumption in the isolated resistance-headed heart of the troutOncorhynchus mykiss
Authors: Agnisola C. , Petersen L. , Mustafa T. 
Published: October 2003

SUMMARYBasal performance, volume loading response and oxygen consumption were determined in a resistance-headed preparation of the isolated trout heart. Two groups of hearts were used: the +CF group, in which the coronary vascular tree was perfused with a flow directly related to the pressure generated by the heart, and the -CF group, in which the coronary flow was set to zero. As a criterion for setting basal performance, the atrial input pressure was set in order to induce the ventricle to produce a cardiac output of 15 ml min-1 kg-1. Once basal conditions were obtained, the preparation was perfused for 30 min, and atrial and aortic pressure, cardiac output, heart rate, coronary pressure and coronary flow were determined at 5 min intervals. At the onset of perfusion, there was no difference in the basal performance between the two groups: the same preload was necessary to get the same cardiac output in both perfusion groups. None of the other performance parameters determined were different. However, after only 5 min of perfusion,the -CF hearts displayed significant adjustments, with increased atrial preload and ventricular preload (mean atrial pressure), and a significant decrease in cardiac output. At the end of the 30 min basal perfusion period,hearts were challenged with a stepwise increase in preload in order to obtain maximal stroke work (volume loading). The effect of coronary perfusion on the heart's response to volume loading was highly significant: the stroke work-preload relationship was significantly shifted towards higher preload values in the -CF group. Also, the maximal work produced by the heart under the experimental conditions used was lower in the -CF group. Rate of oxygen consumption of the heart increased significantly with volume loading, from a basal value of approximately 20 μl O2 min-1g-1 to approx. 40 μl O2 min-1g-1, but was not significantly affected by the absence of coronary perfusion. Mechanical efficiency under basal conditions was approximately 17%,but was not affected by either volume loading or coronary perfusion. Taken as a whole, these data represent direct evidence of the effect of coronary perfusion on the mechanical performance of the trout heart, but also show that these effects are limited by significant self-adjustments that occur in the heart.
Chemosensory tuning to a host recognition cue in the facultative specialist larvae of the mothManduca sexta
Authors: del Campo Marta L. , Miles Carol I. 
Published: October 2003

SUMMARYLarvae of Manduca sexta are facultative specialists on plants in the family Solanaceae. Larvae reared on solanaceous foliage develop a strong preference for their host; otherwise, they remain polyphagous. The host-specific recognition cue in potato foliage for Manduca larvae is the steroidal glycoside, indioside D. Two pairs of galeal taste sensilla, the lateral and medial sensilla styloconica, are both necessary and sufficient for the feeding preferences of host-restricted larvae. We conducted electrophysiological tip recordings from sensilla of solanaceous or wheat germ diet-reared larvae. For each animal, recordings of the responses to indioside D, glucose, tomatine and KCl were compared. All responses included both phasic and tonic portions. The sensilla styloconica of solanaceous-reared larvae were tuned to indioside D, defined as maintaining a high sensitivity to indioside D, while showing lower sensitivity to other plant compounds. Half of the sensillar neurons of solanaceous-reared larvae were `tuned' to indioside D,whereas those of wheat germ diet-reared larvae were not. The different responses between the two types of animals were a result of changes of individual receptor cells' responses in the sensilla. Feeding on solanaceous foliage therefore appears to result in a modification of the physiological responses of individual taste receptor cells that causes them to be tuned to the host-recognition cue indioside D. We propose that this tuning is the basis for the host-restricted larvae's strong behavioral preferences for solanaceous foliage.