bluuebunny/crossref_metadata_2025_split huggingface dataset:
Existence of Lipschitz minimizers for the three-well problem in solid-solid phase transitions
Authors: Conti Sergio , Dolzmann Georg , Kirchheim Bernd 
Published: January 2007

The three-well problem consists in looking for minimizers

u:\Omega \subset \mathbb{R}^{3}\rightarrow \mathbb{R}^{3}

of a functional

I(u) = \int _{\Omega }W(\mathrm{∇}u)\:\mathrm{d}x

, where the elastic energy

W

models the tetragonal phase of a phase-transforming material. In particular,

W

attains its minimum on

K = \bigcup _{i = 1}^{3}\mathrm{SO}(3)U_{i}

, with

U_{i}

being the three distinct diagonal matrices with eigenvalues

(\lambda ,\lambda ,\tilde \lambda)

,

\lambda ,\tilde \lambda > 0

and

\lambda \neq \tilde \lambda

. We show that, for boundary values

F

in a suitable relatively open subset of

\mathbb{M}^{3 \times 3} \cap \{F:\mathrm{\det }F = \mathrm{\det }U_{1}\}

, the differential inclusion

\begin{cases}
\mathrm{∇}u \in K & \text{in }\Omega , \\ u(x) = Fx & \text{on }\partial \Omega
\end{cases}

has Lipschitz solutions.

Résumé

Le problème de type triple puits consiste en la recherche de minimizers

u\:\text{:}\Omega \subset \mathbb{R}^{3}\rightarrow \mathbb{R}^{3}

d'une fonctionnelle

I(u) = \int _{\Omega }W(\mathrm{∇}u)\:\mathrm{d}x

, où l'énergie élastique

W

modèle la phase tétragonale d'un matériel à mémoire de forme. En particulier,

W

atteint son minimum sur

K = \bigcup _{i = 1}^{3}\mathrm{SO}(3)U_{i}

, avec

U_{i}

les trois matrices diagonales distinctes avec les valeurs propres

(\lambda ,\lambda ,\tilde \lambda)

,

\lambda ,\tilde \lambda > 0

et

\lambda \neq \tilde \lambda

. Nous montrons que, pour des conditions au bord

F

dans un sous-ensemble bien choisi relativement ouvert de

\mathbb{M}^{3 \times 3} \cap \{F\text{:}\:\mathrm{\det }F = \mathrm{\det }U_{1}\}

, l'inclusion différentiele

\begin{cases}
\mathrm{∇}u \in K & \text{in }\Omega , \\ u(x) = Fx & \text{on }\partial \Omega
\end{cases}

a des solutions

u \in W^{1,\infty }(\Omega ;\mathbb{R}^{3})

.
SChiSM2: creating interactive web page annotations of molecular structure models using Jmol
Authors: Cammer Stephen 
Published: January 2007

AbstractSummary: SChiSM2 is a web server-based program for creating web pages that include interactive molecular graphics using the freely-available applet, Jmol, for illustration. The program works with Internet Explorer and Firefox on Windows, Safari and Firefox on Mac OSX and Firefox on Linux.Availability: The program can be accessed at the following address:Contact: cammer@vbi.vt.edu
Archaebacterial reverse gyrase cleavage-site specificity is similar to that of eubacterial DNA topoisomerases I
Authors: Kovalsky O.I. , Kozyavkin S.A. , Slesarev A.I. 
Published: January 2007

Abstract
ATP-dependent type I topoisomerases from extremely thermophllic archaebacterla - reverse gyrases - drive positive supercoiling of DNA. We showed that reverse gyrase from Desulfurococcus amylolytlcus breaks the DNA at specific sites and covalentty binds to the 5′ end. In 30 out of 31 sites located in pBR322 DNA fragments, cleavage occurs at the sequence 5′–CNNN∣–(N is any base). The same rule was previously shown to hold for single-stranded DNA breakage by eubacterial topoisomerases I. The relative cleavage frequencies at different sites depend on Mg 2+ and temperature. We discuss the possible physiological and mechanistic role of the above specificity of the bacterial topoisomerases I.
1D and 2D Cole‐Cole‐inversion of time‐domain induced‐polarization data
Authors: Hönig Mark , Tezkan Bülent 
Published: January 2007

ABSTRACTA new method for the 2D inversion of induced polarization (IP) data in the time domain has been developed. The entire IP transients were observed and inverted into 2D Cole‐Cole earth models, including resistivity, chargeability, relaxation time and the frequency constant. Firstly, a modified 1D time‐domain electromagnetic algorithm was used to calculate the response of a layered polarizable ground. The transient signals were then inverted using the Marquardt method to derive the Cole‐Cole parameters of each layer. However, model calculations showed that the EM effects could be neglected for the time range (>1 ms) and for the transmitter–receiver distances (<50 m) used in this study. Therefore, the induction effects were not considered for the solution of the 2D inverse problem and a DC solution was applied. An approximative forward algorithm was introduced in order to calculate the IP transients directly in the time domain and in order to speed up the inverse procedure. The approximation is highly accurate, and this is demonstrated by comparing the approximations with their exact solutions up to 3D.The inverse algorithm presented consists of two steps. The transient voltages of an array data set were inverted separately into a two‐dimensional resistivity model for each time channel. The time‐dependent resistivity of each cell was then interpreted as the response of a homogeneous half‐space. In the 2D inversion algorithm, a 3D DC algorithm was used as a forward operator. The method only requires a standard 2D DC inversion and a homogenous half‐space Cole‐Cole inversion.The developed algorithm has been successfully applied to synthetic data sets and to a field data set obtained from a waste site situated close to Düren in Germany.
Validity of the long‐wave approximation in periodically layered media
Authors: Arntsen Borge 
Published: January 2007

ABSTRACTIn seismic modelling, a stack of thin layers is often replaced by an effective equivalent anisotropic homogeneous slab. For waves with finite wavelength, this is an approximation, and the error thus introduced can be quantified by considering the relative error in the phase velocity between the layer stack and the effective medium. For periodic layering, the relative phase‐velocity error can be expressed in closed form as a function of wavelength, reflection coefficients and layer thicknesses. By comparing the relative phase‐velocity error with laboratory measurements and numerical simulations, we find that the difference in seismic response between a periodic layer stack and an equivalent effective medium depends not only on wavelength, but it also depends significantly on reflection coefficients and the ratio between layer thicknesses. For a 1% relative error in the phase velocity, and if all layers have the same thickness measured in vertical traveltime, we find that the wavelength must be larger than approximately three times the layer period for a reflection coefficient of 0.1, but this increases to 13 times the layer period for a reflection coefficient of 0.9, which is highly unrealistic in a geological setting.
Phosphate‐dependent modulation of c‐di‐GMP levels regulates Pseudomonas fluorescens Pf0‐1 biofilm formation by controlling secretion of the adhesin LapA
Authors: Monds Russell D. , Newell Peter D. , Gross Robert H. , O'Toole George A. 
Published: January 2007

SummaryBiofilm formation is commonly described as a developmental process regulated by environmental cues. In the current study we present a mechanistic model to explain regulation of Pseudomonas fluorescens biofilm formation by the environmentally relevant signal inorganic phosphate (Pi). We show that activation of the Pho regulon, the major pathway for adaptation to phosphate limitation, results in conditional expression of a c‐di‐GMP phosphodiesterase referred to as RapA. Genetic analysis indicated that RapA is an inhibitor of biofilm formation and required for loss of biofilm formation in response to limiting Pi. Our results suggest that RapA lowers the level of c‐di‐GMP, which in turn inhibits the secretion of LapA, a large adhesion required for biofilm formation by P. fluorescens. The ability of c‐di‐GMP to modulate protein secretion is a novel finding and further extends the biological influence of c‐di‐GMP beyond that of regulating exopolysaccharide synthesis and motility. Interestingly, Pho regulon expression does not impinge on the rate of attachment to a surface but rather inhibits the transition of cells to a more stable interaction with the surface. We hypothesize that Pho regulon expression confers a surface‐sensing mode on P. fluorescens and suggest this strategy may be broadly applicable to other bacteria.
Regulation of virulence in Bacillus anthracis: the phosphotransferase system transmits the signals
Authors: Stülke Jörg 
Published: January 2007

Summary Bacillus anthracis causes host damage by producing two toxins, the lethal factor and the oedema factor. Their production and that of other virulence factors depend on the activity of the AtxA transcription factor. The mechanisms that control AtxA activity are reported in this issue of Molecular Microbiology. The protein can be phosphorylated at two distinct sites by components of the phosphotransferase system (PTS). One phosphorylation event stimulates transcription activation by AtxA, whereas the second prevents AtxA activity. This mode of regulation and the predicted domain structures are highly similar to transcription regulators controlled by PTS regulation domains (PRDs). Thus, the phosphorylated domains of AtxA represent a novel form of PRDs. As a similar organization is found in transcription regulators in many other pathogens, AtxA might become the paradigm of a new class of virulence regulators.
Growth of the protozoan parasite Entamoeba histolytica in 5-azacytidine has limited effects on parasite gene expression
Authors: Ali Ibne Karim M , Ehrenkaufer Gretchen M , Hackney Jason A , Singh Upinder 
Published: January 2007

Abstract

Background
In higher eukaryotes DNA methylation regulates important biological functions including silencing of gene expression and protection from adverse effects of retrotransposons. In the protozoan parasite Entamoeba histolytica, a DNA methyltransferase has been identified and treatment with 5-azacytidine (5-AzaC), a potent inhibitor of DNA methyltransferase, has been reported to attenuate parasite virulence. However, the overall extent of DNA methylation and its subsequent effects on global gene expression in this parasite are currently unknown.

Results
In order to identify the genome-wide effects of DNA methylation in E. histolytica, we used a short oligonucleotide microarray representing 9,435 genes (~95% of all annotated amebic genes) and compared the expression profile of E. histolytica HM-1:IMSS parasites with those treated with 23 μM 5-AzaC for up to one week. Overall, 2.1% of genes tested were transcriptionally modulated under these conditions. 68 genes were upregulated and 131 genes down regulated (2-fold change; p-value < 0.05). Sodium-bisulfite treatment and sequencing of genes indicated that there were at least two subsets of genes with genomic DNA methylation in E. histolytica: (i) genes that were endogenously silenced by genomic DNA methylation and for which 5-AzaC treatment induced transcriptional de-repression, and (ii) genes that have genomic DNA methylation, but which were not endogenously silenced by the methylation. We identified among the genes down regulated by 5-AzaC treatment a cysteine proteinase (2.m00545) and lysozyme (52.m00148) both of which have known roles in amebic pathogenesis. Decreased expression of these genes in the 5-AzaC treated E. histolytica may account in part for the parasites reduced cytolytic abilities.

Conclusion
This work represents the first genome-wide analysis of DNA-methylation in Entamoeba histolytica and indicates that DNA methylation has relatively limited effects on gene expression in this parasite.
Motives and preferences of general practitioners for new collaboration models with medical specialists: a qualitative study
Authors: Berendsen Annette J , Benneker Wim HGM , Meyboom-de Jong Betty , Klazinga Niek S , Schuling Jan 
Published: January 2007

Abstract
Background
Collaboration between general practitioners (GPs) and specialists has been the focus of many collaborative care projects during the past decade. Unfortunately, quite a number of these projects failed. This raises the question of what motivates GPs to initiate and continue participating with medical specialists in new collaborative care models.
The following two questions are addressed in this study:
What motivates GPs to initiate and sustain new models for collaborating with medical specialists?
What kind of new collaboration models do GPs suggest?

Methods
A qualitative study design was used. Starting in 2003 and finishing in 2005, we conducted semi-structured interviews with a purposive sample of 21 Dutch GPs. The sampling criteria were age, gender, type of practice, and practice site. The interviews were recorded, fully transcribed, and analysed by two researchers working independently. The resulting motivational factors and preferences were grouped into categories.

Results
'Developing personal relationships' and 'gaining mutual respect' appeared to dominate when the motivational factors were considered. Besides developing personal relationships with specialists, the GPs were also interested in familiarizing specialists with the competencies attached to the profession of family medicine. Additionally, they were eager to increase their medical knowledge to the benefit of their patients. The GPs stated a variety of preferences with respect to the design of new models of collaboration.

Conclusion
Developing personal relationships with specialists appeared to be one of the dominant motives for increased collaboration. Once the relationships have been formed, an informal network with occasional professional contact seemed sufficient.
Although GPs are interested in increasing their knowledge, once they have reached a certain level of expertise, they shift their focus to another specialty.
The preferences for new collaboration models are diverse. A possible explanation for the differences in the preferences is that professionals are more knowledge driven than organisation driven as the acquiring of new knowledge is considered more important than the route by which this is achieved. A new collaboration model seems a way to acquire knowledge. Once this is achieved the importance of a model possibly diminishes, whereas the professional relationships last.
Modification of the crystal habit of celecoxib for improved processability
Authors: Banga Sheere , Chawla Garima , Varandani Deepak , Mehta B R , Bansal Arvind K 
Published: January 2007

Abstract
Crystallization is often used in the pharmaceutical industry for purification and isolation of drugs, and also as a means of generating polymorphs or isomorphs. The aim of this study was to investigate the role of extrinsic crystallization parameters on the crystallized product, with special emphasis on improving the mechanical properties of acicular celecoxib. Celecoxib isomorphs were prepared using different techniques (solvent crystallization and vapour diffusion) and crystallization conditions (solvents, stirring, degree of supersaturation, crystallization temperature and seeding). Powder X-ray diffractometry, spectroscopic and thermal methods were used to investigate physical characteristics of crystals. Growth kinetics and aggregation dynamics of crystallization in polar and non-polar solvents were simulated using a dynamic light scattering method. The quick appearance of broad peaks over the range of 10–8000 nm in chloroform during crystallization simulation studies indicated faster aggregation in non-polar solvents. Aspect ratio, flow, compressibility and surface area of recrystallized products were also determined. Surface topography was determined by atomic force microscopy and the lath-shaped crystals (aspect ratio of 2–4) exhibited a roughness index of 1.79 in comparison with 2.92 for needles. Overall, the lath-shaped isomorphs exhibited improved flow and better compressibility.
Conversion of (sp3)C–F Bonds of Alkyl Fluorides to (sp3)C–Heteroatom (Heteroatom = I, SR, SeR, TeR) Bonds by the Use of Magnesium Reagents Having Heteroatom Substituents
Authors: Ara Begum Shameem , Terao Jun , Kambe Nobuaki 
Published: January 2007

Abstract
A convenient method for conversion of (sp3)C–F bonds to (sp3)C–Z (Z = I, SR, SeR, TeR) bonds has been developed. The reaction proceeds at room temperature using magnesium salts (Z–MgX). SN2 mechanism for substitiution of primary alkyl fluorides with MgI2 in ether was supported by the inversion of the stereochemistry of the carbon connecting to F.
Should the Aspiring Wise Man Travel? A Conflict in Seneca's Thought
Authors: Montiglio Silvia 
Published: January 2007

This article examines the connection between traveling and wisdom in Seneca's writings. It argues that Seneca is ambivalent vis-Ã -vis traveling: on the one hand, he deems the activity unnecessary or even dangerous, insofar as it is at odds with mental focus and challenges the ideal of happiness as "home" (domestica felicitas); on the other, he admires those who travel for the sake of knowledge and connects the mobility of the body with the "cosmic flight" of the mind. In line with a long-established tradition, Seneca views travel as the first step towards philosophical inquiry. The ambivalence extends to the assessment of imperialistic use of travel. Though Seneca loudly condemns it as a manifestation of greed, he also shows admiration for several Roman conquerors.
Baka and the Magic of the State: Between Autochthony and Citizenship
Authors: Leonhardt Alec 
Published: January 2007

Abstract:While Baka “Pygmies” are regarded as among Africa's most indigenous peoples, their autochthony seems lacking in features that would give them standing for special consideration by die state. Somehow, indigenousness does not equal autochthony. Other mobile indigenous peoples such as traders and pastoralists have also been seen as less than autochthonous. These groups lack “roots in the soil,” which makes them less subject to the authority of the state than farmers. Further, as an acephalous society, Baka political culture cannot be appropriately adjusted to interact with the hierarchical structure of the state and related institutions. For this reason the problematic autochthony of Baka is less an issue of rights within the existing structure of the state—of civil rights—than of human rights. Unfortunately, this human rights issue is not really on any policy agenda, not even that of the working group for the U.N. Draft Declaration on the Rights of Indigenous Peoples.
Integrated Services for Frail Elders (SIPA): A Trial of a Model for Canada
Authors: Béland Francois , Bergman Howard , Lebel Paule , Dallaire Luc , Fletcher John , Tousignant Pierre , Contandriopoulos André-Pierre 
Published: January 2007

ABSTRACTLe complexe formé par les maladies chroniques, les épisodes de maladies aiguës, les déficiences physiologiques, les incapacités fonctionnelles et les problèmes cognitifs dominent les personnes âgées fragiles. Elles comptent sur l'aide des programmes sociaux et de Santé qui, au Canada, sont encore fragmentés. Le SIPA (Services intégrés pour les personnes âgées fragiles) est un modèle de services intégrés basé sur des services de proximité, une équipe multidisciplinaire et un gestionnaire de cas qui détiennent la responsabilité clinique de l'ensemble des services sociaux et de Santé requis, la capacité de mobiliser des ressources en fonction des besoins et l'application de protocole de soins. Le projet de démonstration SIPA a utilisé un devis expérimental avec assignation aléatoire de 1230 participants, de deux quartiers de Montréal, dans un groupe expérimental et un groupe témoin. Les coûts des services institutionnels ont été de 4270$; inférieur dans le SIPA comparés au groupe témoin, les coûts des services de proximité ont été supérieurs de 3394$;. La proportion des personnes en attente d'hébergement en hôpitaux de courte durée a été deux fois plus élevée dans le groupe témoin que dans le groupe SIPA. Les coûts des hospitalisations de courte durée des personnes du SIPA avec incapacité dans les activités de la vie quotidienne ont été inférieurs d'au moins 4000$; à ceux des personnes du groupe témoin. En conclusion, l'expérimentation SIPA démontre qu'il est possible de s'engager dans des projets de démonstration ambitieux et rigoureux au Canada. Ces résultats ont été obtenus sans augmentation des coûts globaux des services sociaux et de santé, sans diminution de la Qualité des soins et sans augmentation du fardeau des personnes âgées et de leurs proches.
M. Paquet. Vivre une expérience de soins à domicile. Sainte-Foy, QC: Les Presses de l'Université Laval, 2004.
Authors: Pérodeau Guilhème 
Published: January 2007

ABSTRACTAccording to the author, this book is an analysis of the underlying family dynamics in caring for an elderly relative. It is primarily for nonspecialists but is of definite interest to health professionals who work with families that are experiencing a situation of dependency. The ideas are presented as a dialogue between the author and a fictional character called “Autonome S'démène” (Independent and Struggling), who is herself a caregiver. This well-written book examines such relevant concepts as the family's hesitation to ask for or even accept an offer of services from the formal network for fear of being invaded by strangers.
Introduction : La culture dans le domaine du droit
Authors: Howes David 
Published: January 2007

Dans leur introduction au livreLaw in the Domains of Culture, Austin Sarat et Thomas Kearns écrivent : «Law and legal studies are relative latecomers to cultural studies. To examine [law in the domains of culture] has been, until recently, a kind of scholarly transgression». L'inverse est vrai aussi : lescultural studies(incluant l'anthropologie) sont arrivées tardivement au droit et aux réflexions sur le droit, alors qu'on assistait, ces dernières décennies, à une irruption remarquable de discours culturels dans le domaine du droit.Il semble bien que l'acquisition d'une certaine «compétence culturelle» soit devenue obligatoire dans les cercles juridiques. Il n'y a pas que la floraison de séminaires et cours sur la «sensibilité culturelle» pour juges, avocats et policiers, mais le «concept de culture» traverse maintenant bien des décisions judiciaires en matière de droits autochtones, et la «défense culturelle» (bien que fortement contestée par certains et toujours sans approbation officielle) est désormais une dimension de nombreux procès criminels impliquant des immigrants. Aussi, laCharte canadienne des droits et libertésréfère à «l'héritage multicultural des Canadiens» (art. 27) dont la préservation et la promotion est une condition de sa propre interprétation.
The “Public”, the ‘Private’, and the Legal Norm of Equality
Authors: Dotan Yoav 
Published: January 2007

RésuméLes cours, devraient-elles appliquer le concept d'égalité tel que développé dans la jurisprudence de droit public aux controverses entre des parties privées? Je propose dans cette note critique que, dans nos sociétés contemporaines, la distinction entre les concepts du «privé» et du «public» se fonde sur la manière de traiter de l'égalité dans ces deux champs d'activité sociale. Il en est ainsi parce que les choses qui sont considérées dans nos sociétés comme «publiques» appartiennent de manière égale à chacun, ce qui n'est pas le cas des choses «privées». Le domaine public est donc dominé par la norme de l'égalité politique alors que celui du droit privé est soumis à l'absence d'une exigence stricte de distribution égalitaire des biens économiques. À date, le phénomène des cours appliquant la norme d'égalité dans le champs du droit privé réfère surtout aux litiges où il s'agissait de maintenir des principes fondamentaux de l'égalité politique, comme la norme interdisant la discrimination raciale. Le phénomène ne met donc pas sérieusement en question la légitimité institutionnelle en démocratie libérale contemporaine.