bluuebunny/crossref_metadata_2025_split huggingface dataset:
NEUTRON STARS AND THE COHERENT NUCLEAR INTERACTION
Authors: GIUDICE E. DEL , MELE R. , PREPARATA G. , GUALDI C. , MANGANO G. , MIELE G. 
Published: November 2004

In the framework of a novel approach to the dynamics of nuclei and large collections of nucleons, which fully exploits the coherent interaction among π’s, nucleons and Δ’s, we derive a new equation of state for neutronic matter. By introducing it in the Tolman-Oppenheimer-Volkof equations we derive the masses and radii of neutron stars as a function of the central density. We obtain a maximum mass Mmax≃2.7 Mʘ and a minimum period of rotation Tmin=0.8 msec.
GRAVITATIONAL LENSING AND CATASTROPHE THEORY
Authors: KAKIGI YUUKO , OKAMURA TAKASHI , FUKUYAMA TAKESHI 
Published: November 2004

Singularities of caustics appearing in the gravitational lensing effect are discussed analytically. The multipole expansion model of the lensing object is mainly studied since it is tractable and universal. Our analyses are confirmed by numerical calculations and applied to the multiple quasar system of PG1115+080. Consistencies with elliptical lens models are also discussed.
CHEMOSTAT EQUATIONS FOR A PREDATOR-PREY CHAIN WITH DELAYED NUTRIENT RECYCLING
Authors: BERETTA E. , FERGOLA P. , TENNERIELLO C. 
Published: November 2004

The problem of the equilibrium stability for the chemostat equation is considered in the special case of a biotic species feeding on one limiting nutrient and predated by another biotic species. Both the biotic species through the decomposition process can return with delay to the chemostat fraction of dead biomass as new nutrient. The delay kernels of nutrient recycling are assumed to be general L2(0, +∞) non-negative functions which admit up to second order finite moments. Two approaches are adopted: the first one applies when both the biotic species have a self-regulating term in their evolution equations and can be worked out without linearizing the equations. This approach does not require any further constraint on delay kernels, whereas it introduces constraints on the remaining parameters of the model. The second approach applies to the linearized equations when the predator self-regulating term is set equal to zero. In this case the stability condition requires a constraint on the average time delays in the recycling processes. Both the approaches are performed by constructing suitable Krasovskii-Lyapunov functionals for the related functional retarded differential equations.
THE RELEVANCE OF SPATIAL STATISTICS ON THE STATISTICAL MODEL BUILDING FOR CORONARY HEART DISEASE
Authors: VASCONCELOS RITA 
Published: November 2004

For a long time, it has been widely acknowledged that putting data on a map underlines important features, and helps in the understanding and interpretation of the real world. Recent and extensive developments of spatial statistics and of geostatistics show the growing importance of this field. Our aim was to help physicians to interpret a very large database on heart diseases (acute myocardial infarction and angina pectoris) on the Madeira Islands. Besides standard techniques, such as loglinear models fitting, we decided to explore the spatial aspect of the question, and to bring in to the analysis recent advances in exploratory and robust data analysis. We show the relevance of spatial statistics on the detection of "hidden" variables.
MATHEMATICAL MODELS FOR HIV TRANSMISSION IN GROUPS OF INJECTING DRUG USERS VIA SHARED DRUG EQUIPMENT
Authors: CAPASSO VINCENZO , SICURELLO FRANCESCO , VILLA MARCO 
Published: November 2004

In many western countries, including Italy, sharing drug injection equipment is one of the main causes of HIV/AIDS spread. In this paper we propose an extension of the classical one population and multiple population mathematical models for the spread of HIV, by providing explicit expressions for the force of infection in terms of a stochastic model for the behaviour of individuals in a friendship group with respect to needle sharing. For the single population model we provide a threshold theorem in terms of the basic reproductive ratio. The extension to the multiple population case is discussed in terms of mixing matrices. The qualitative behaviour for different choices of such matrices is shown by computer simulations.
MODELLING THE FELINE IMMUNODEFICIENCY VIRUS WITHIN POPULATIONS OF DOMESTIC CATS (Felis catus)
Authors: COURCHAMP F. , PONTIER D. , ARTOIS M. 
Published: November 2004

We attempt to model the circulation of the Feline Immunodeficiency Virus (FIV), a retrovirus analogous to the HIV, within populations of domestic cats. Domestic cats exhibit different patterns of population dynamics, social behaviour and reproductive strategies. In fact, cats can be either solitary or living in large social groups, with many intermediate states. The aim of the presented model is to provide a conceptualization of the mechanisms of FIV spreading rather than to be a predictive tool. As one of our goals is to integrate easily new informations when available, and to remain simple and close to the biological reality, parameters, such as sex, age classes and dispersion, have been incorporated successively. This model can also be adapted to different types of cat populations by simple changes, as it could be to other host populations. A study of the stability of the model has been done. Based on available data, values of two parameters has been estimated: the carrying capacity and the transmission rate. Results are in good accordance with biological data.
A MECHANOCHEMICAL MODEL FOR ADULT DERMAL WOUND CONTRACTION
Authors: OLSEN L. , SHERRATT J. A. , MAINI P. K. 
Published: November 2004

We propose a deterministic mathematical model to describe the biomechanics and cell biology of wound contraction, a ubiquitous feature in the normal healing of adult dermal excisional wounds. Our aim is to use the model to obtain a greater understanding of the mechanisms involved in wound contraction and in clinically important healing pathologies such as fibrocontractive diseases. The model consists of two cell types — fibroblasts aand myofibroblasts, a generic chemical growth factor and a viscoelastic extracellular matrix (which includes type I collagen). The essential processes of cell motility, proliferation, differentiation and mechanical interaction with the matrix are modelled from experimental data. A novel aspect of this approach is the inclusion of two cell types. The model is shown not only to simulate normal wound contraction (in good agreement with experimental data), but also to yield valuable insight into the fundamental mechanisms involved and the pathogenesis of fibrocontractive diseases, and makes experimentally testable predictions of the effects of varying biological parameters. Two important results are that collagen remodelling is more intrinsic to scar formation than to wound contraction and that dynamic gradients in the cell and matrix densities are the driving force for wound contraction.
GENETIC INTERPRETATION OF DISCRETE HEREDITY I: FINITE SET THEORY ORDERS GENES IN SMALL POPULATION
Authors: GILLOIS MICHEL 
Published: November 2004

E. Mayr [55] emphasizes that population genetic theories regard a population as a bag full of colored beans. Such a simplified way of thinking is misleading. M. Gillois [19,20] introduces finite set theory in population genetic theories. Consequently he orders genes in small population and he develops new concepts as "identity situations", "constraint situations" and "generalized genotypes". This paper presents these new concepts which shall be used in order to study dynamics of genes in small populations. These results are basic for deterministic models. Contrary to stochastic models, deterministic models are fully in accordance to the physical fate of genes through individual meiosis and mating.
Effect of Amine/Sodium Fluoride Rinsing on Toothbrush Abrasion of Softened Enamel in situ
Authors: Lussi A. , Jaeggi T. , Gerber C. , Megert B. 
Published: November 2004

The aim of this study was to test the effect of fluoride rinsing on the prevention of toothbrush abrasion of softened enamel in situ. For softening, the samples were immersed in 0.1 <i>M</i> citric acid (pH 3.5) for 3 min. Eight test subjects had to make 5 runs in which 4 slabs per run were attached to intraoral appliances. They were as follows: (1) no softening, no fluoride rinsing (control 1); (2) softening, no fluoride rinsing (control 2); (3) softening, rinsing in situ with a sodium/amine fluoride rinsing solution (250 ppm F) for 30 s; (4) rinsing in situ with the sodium/amine fluoride rinsing solution (250 ppm F) for 30 s, softening; (5) softening, rinsing in situ with an experimental amine fluoride-containing rinsing solution (250 ppm F) for 30 s. After exposure for 60 min to the oral milieu, the volunteers brushed the samples for 30 s with toothpaste and the loss of tooth substance was determined. For each test person, the secretion rate of resting and paraffin-stimulated saliva, buffering capacity and pH were measured. Toothbrush abrasion in situ was not significantly lower using the fluoride rinsing solutions before or after softening the enamel compared to no rinsing (p > 0.05). Multiple linear regression analyses revealed that 57% of the variation in toothbrush abrasion could be attributed to the severity of softening (p < 0.001) and the pH of stimulated saliva (p < 0.001). It was concluded that a single rinse for 30 s had no statistically significant effect on the prevention of toothbrush abrasion of softened enamel.
The impact of two multiple-choice question formats on the problem-solving strategies used by novices and experts
Authors: Coderre Sylvain P , Harasym Peter , Mandin Henry , Fick Gordon 
Published: November 2004

Abstract
Background
Pencil-and-paper examination formats, and specifically the standard, five-option multiple-choice question, have often been questioned as a means for assessing higher-order clinical reasoning or problem solving. This study firstly investigated whether two paper formats with differing number of alternatives (standard five-option and extended-matching questions) can test problem-solving abilities. Secondly, the impact of the alternatives number on psychometrics and problem-solving strategies was examined.

Methods
Think-aloud protocols were collected to determine the problem-solving strategy used by experts and non-experts in answering Gastroenterology questions, across the two pencil-and-paper formats.

Results
The two formats demonstrated equal ability in testing problem-solving abilities, while the number of alternatives did not significantly impact psychometrics or problem-solving strategies utilized.

Conclusions
These results support the notion that well-constructed multiple-choice questions can in fact test higher order clinical reasoning. Furthermore, it can be concluded that in testing clinical reasoning, the question stem, or content, remains more important than the number of alternatives.
Prenylation inhibitors stimulate both estrogen receptor α transcriptional activity through AF-1 and AF-2 and estrogen receptor β transcriptional activity
Authors: Cestac Philippe , Sarrabayrouse Guillaume , Médale-Giamarchi Claire , Rochaix Philippe , Balaguer Patrick , Favre Gilles , Faye Jean-Charles , Doisneau-Sixou Sophie 
Published: November 2004

Abstract
Introduction
We showed in a previous study that prenylated proteins play a role in estradiol stimulation of proliferation. However, these proteins antagonize the ability of estrogen receptor (ER) α to stimulate estrogen response element (ERE)-dependent transcriptional activity, potentially through the formation of a co-regulator complex. The present study investigates, in further detail, how prenylated proteins modulate the transcriptional activities mediated by ERα and by ERβ.

Methods
The ERE-β-globin-Luc-SV-Neo plasmid was either stably transfected into MCF-7 cells or HeLa cells (MELN cells and HELN cells, respectively) or transiently transfected into MCF-7 cells using polyethylenimine. Cells deprived of estradiol were analyzed for ERE-dependent luciferase activity 16 hours after estradiol stimulation and treatment with FTI-277 (a farnesyltransferase inhibitor) or with GGTI-298 (a geranylgeranyltransferase I inhibitor). In HELN cells, the effect of prenyltransferase inhibitors on luciferase activity was compared after transient transfection of plasmids coding either the full-length ERα, the full-length ERβ, the AF-1-deleted ERα or the AF-2-deleted ERα. The presence of ERα was then detected by immunocytochemistry in either the nuclei or the cytoplasms of MCF-7 cells. Finally, Clostridium botulinum C3 exoenzyme treatment was used to determine the involvement of Rho proteins in ERE-dependent luciferase activity.

Results
FTI-277 and GGTI-298 only stimulate ERE-dependent luciferase activity in stably transfected MCF-7 cells. They stimulate both ERα-mediated and ERβ-mediated ERE-dependent luciferase activity in HELN cells, in the presence of and in the absence of estradiol. The roles of both AF-1 and AF-2 are significant in this effect. Nuclear ERα is decreased in the presence of prenyltransferase inhibitors in MCF-7 cells, again in the presence of and in the absence of estradiol. By contrast, cytoplasmic ERα is mainly decreased after treatment with FTI-277, in the presence of and in the absence of estradiol. The involvement of Rho proteins in ERE-dependent luciferase activity in MELN cells is clearly established.

Conclusions
Together, these results demonstrate that prenylated proteins (at least RhoA, RhoB and/or RhoC) antagonize the ability of ERα and ERβ to stimulate ERE-dependent transcriptional activity, potentially acting through both AF-1 and AF-2 transcriptional activities.
Autologous and Allogeneic Stem-Cell Transplantation As Salvage Treatment of Acute Promyelocytic Leukemia Initially Treated With All-Trans-Retinoic Acid: A Retrospective Analysis of the European Acute Promyelocytic Leukemia Group
Authors: de Botton S. , Fawaz A. , Chevret S. , Dombret H. , Thomas X. , Sanz M. , Guerci A. , San Miguel J. , de la Serna J. , Stoppa A.M. , Reman O. , Stamatoulas A. , Fey M. , Cahn J.Y. , Sotto J.J. , Bourhis J.H. , Parry A. , Chomienne C. , Degos L. , Fenaux P. 
Published: November 2004

Purpose To retrospectively determine the outcome of acute promyelocytic leukemia (APL) patients who underwent autologous or allogeneic stem-cell transplantation (SCT) during second complete remission. Patients and Methods Of 122 relapsing patients included in two successive multicenter APL trials who achieved hematological second complete remission (generally after a salvage regimen of all-trans-retinoic acid [ATRA] combined with chemotherapy), 73 (60%) received allogeneic (n = 23) or autologous (n = 50) SCT. Results Seven-year relapse-free survival (RFS), event-free survival (EFS), and overall survival (OS) in the autologous SCT group were 79.4%, 60.6%, and 59.8%, respectively, with a transplant-related mortality (TRM) of 6%. Of the 28 and two patients autografted with negative and positive, respectively, reverse transcriptase-polymerase chain reaction before auto SCT, three (11%) and one relapsed, respectively. In the allogeneic SCT group, 7-year RFS, EFS, and OS were 92.3%, 52.2%, and 51.8%, respectively, with 39% TRM. OS was significantly better in the autologous SCT group than in the allogeneic SCT group (P = .04), whereas RFS and EFS did not differ significantly (P = .19 and P = .11, respectively). In patients not receiving transplantation, 7-year RFS, EFS, and OS were 38%, 30.4%, and 39.5%, respectively. Conclusion These retrospective data suggest that autologous SCT is very effective in APL relapsing after treatment with ATRA if performed in molecular remission. Allogeneic SCT yields few relapses, but it is associated with high TRM when performed after salvage with very intensive chemotherapy. Salvage with arsenic trioxyde, which has lower toxicity, should further improve the outcome of relapsing APL, especially before allogeneic SCT.
New synthesis of PNA–3′DNA linker monomers, useful building blocks to obtain PNA/DNA chimeras
Authors: Musumeci Domenica , Roviello Giovanni N. , Valente Margherita , Sapio Roberto , Pedone Carlo , Bucci Enrico M. 
Published: November 2004

AbstractA new synthetic strategy to get the PNA–3′DNA linker with the monomethoxytrityl (Mmt) group as temporary protection of the backbone to be used for the synthesis of PNA/DNA chimeras was employed and a convenient strategy to obtain Mmt PNA monomers was developed. The synthetic strategies take advantage of the introduction of the acid‐labile Mmt‐protecting group in the first step. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Thermophilic biohydrogen production from glucose with trickling biofilter
Authors: Oh You‐Kwan , Kim Seo Hyoung , Kim Mi‐Sun , Park Sunghoon 
Published: November 2004

AbstractThermophilic H2 production from glucose was studied at 55–64°C for 234 days using a continuous trickling biofilter reactor (TBR) packed with a fibrous support matrix. Important parameters investigated included pH, temperature, hydraulic retention time (HRT), and glucose concentration in the feed. The optimal pH and temperature were 5.5 and 60°C, respectively. With decreasing HRT or increasing inlet glucose concentration, volumetric H2 production rate increased but the H2 production yield to glucose decreased gradually. The biogas composition was almost constant at 53 ± 4% (v/v) of H2 and 47 ± 4% (v/v) of CO2. No appreciable CH4 was detected when the reactor was under a normal operation. The carbon mass balance showed that, in addition to cell mass, lactate, n‐butyrate, CO2, and acetate were major products that comprised more than 85% of the carbon consumed. The maximal volumetric H2 production rate and H2 yield to glucose were 1,050 ± 63 mmol H2/l·d and 1.11 ± 0.12 mol H2/mol glucose, respectively. These results indicate that the thermophilic TBR is superior to most suspended or immobilized reactor systems reported thus far. This is the first report on continuous H2 production by a thermophilic TBR system. © 2004 Wiley Periodicals, Inc.
Self‐Assembly of the Octanuclear Cluster [Cu8(OH)10(NH2(CH2)2CH3)12]6+ and the One‐Dimensional N‐Propylcarbamate‐Linked Coordination Polymer {[Cu(O2CNH(CH2)2CH3)(NH2(CH2)2CH3)3](ClO4)}n
Authors: Bramsen Fabienne , Bond Andrew D. , McKenzie Christine J. , Hazell Rita G. , Moubaraki Boujemaa , Murray Keith S. 
Published: November 2004

AbstractThe reaction of Cu(ClO4)2⋅6 H2O and n‐propylamine in methanol gives two high‐nuclearity products of well‐defined compositions. At amine concentrations greater than seven equivalents compared to copper ion concentration, the system fixes carbon dioxide from air to form the one‐dimensional carbamate‐bridged coordination polymer, {[Cu(μ2‐O,O′‐O2CNH(CH2)2CH3)(NH2(CH2)2CH3)3](ClO4)}n ({1‐ClO4}n). Lower relative amine concentrations lead to the self‐assembly of an octanuclear copper‐amine‐hydroxide cluster [Cu8(OH)10(NH2(CH2)2CH3)12]6+ (2). Both compounds exhibit unique structures: {1‐ClO4}n is the first μ2‐O,O′‐mono‐N‐alkylcarbamate‐linked coordination polymer and 2 is the largest copper‐hydroxide‐monodentate amine cluster identified to date. The crystal structures indicate that the size of the n‐propyl group is probably crucial for directing the formation of these compounds. Magnetic susceptibility studies indicate very weak antiferromagnetic coupling for 1. The octanuclear cluster 2 displays slightly stronger net antiferromagnetic coupling, despite the presence of a number of Cu‐O(H)‐Cu angles below the value of about 97° that would normally be expected to yield ferromagnetic coupling.
Supported Ionic Liquid Catalysis
Authors: Mehnert Christian P. 
Published: November 2004

AbstractSupported ionic liquid catalysis is a concept which combines the advantages of ionic liquids with those of heterogeneous support materials. The viability of this concept has been confirmed by several studies which have successfully confined various ionic phases to the surface of support materials and explored their potential catalytic applications. Although the majority of the evaluated supports were silica based, several studies focused on polymeric materials including membranes. The preparation of these materials was achieved by using two different immobilization approaches. The first approach involves the covalent attachment of ionic liquids to the support surface whereas the second simply deposits the ionic liquid phases containing catalytically active species on the surface of the support. Herein recent advances made in this area are described.
Structural and Magnetic Investigations of the Mixed‐Valence FeII,III Two‐Dimensional Layer Complex, [Fe2IIFe2III(HCOO)10(C6H7N)6]n
Authors: Overgaard Jacob , Rentschler Eva , Timco Grigore A. , Larsen Finn K. 
Published: November 2004

AbstractThe structure of the complex, [Fe2IIFe2III(HCOO)10(C6H7N)6]n, (1) exhibits a neutral two‐dimensional layer network of alternating iron(II) and iron(III) ions, bridged equatorially by formate groups. All iron atoms are octahedrally coordinated, with iron(III) coordinating axially to one γ‐picoline and one formate group, while the iron(II) centers interact axially with two γ‐picoline groups, above and below the layer plane. The complex crystallizes in the triclinic space group P1 at all studied temperatures [at 120 K, the cell dimensions are: a=10.228(1), b=12.071(1), c=12.072(1) Å, α=89.801(2), β=71.149(2), γ=73.371(2)°]. An intralayer antiferromagnetic exchange interaction of J=−2.8 cm−1 between iron(II) and iron(III) was observed in the magnetic studies. Decreasing the temperature to close to 20 K causes a magnetic‐ordering phenomenon to occur and a low‐temperature phase with a long‐range antiferromagnetic spin orientation appears. The magnetic phase transition was confirmed by Mössbauer spectroscopic studies at temperatures above and below the critical temperature. Structural information of 1 from synchrotron X‐ray diffraction data collected at room temperature and 16 K suggests that the antiferromagnetic ordering is caused by an enhanced π–π interaction between χ‐picoline groups from adjacent layers.
Light‐Scattering Study of the Aggregation of Syndiotactic Poly(methyl methacrylate) in Solution
Authors: Chen Wenna , Zhao Yue , Jiang Yong , Yan Dadong , Han Charles C. 
Published: November 2004

AbstractSyndiotactic poly(methyl methacrylate) (s‐PMMA) may undergo aggregation in n‐butyl chloride (n‐BuCl) at temperatures below the θ temperature. The aggregation behavior of the s‐PMMA with weight‐average molecular weight Mw=6.06×105 g mol−1 was studied by a combination of static and dynamic laser‐light‐scattering experiments. A solution of concentration 1.12×10−4 g mL−1 was quenched from 50 °C (above the θ temperature in n‐BuCl, 35 °C) to 12 °C, and the aggregation process was measured over 60 h. The time dependence of Mw, the root‐mean‐square z‐average radius of gyration <Rg>, and the average hydrodynamic radius <Rh> were used to monitor the growth of the aggregates, with the result Mw∼<Rg> (where df=1.98±0.02), which implies the formation of a fractal aggregate. The observed fractal dimension, df, is close to that expected for a reaction‐limited cluster aggregation for which df=2.1. In addition, atomic force microscopy was used to image the aggregates.