Some solutions to obtain very efficient separations in isocratic and gradient modes using small particles size and ultra-high pressure.

The UHPLC strategy which combines sub-2 microm porous particles and ultra-high pressure (>1000 bar) was investigated considering very high resolution criteria in both isocratic and gradient modes, with mobile phase temperatures between 30 and 90 degrees C. In isocratic mode, experimental conditions to reach the maximal efficiency were determined using the kinetic plot representation for DeltaP(max)=1000 bar. It has been first confirmed that the molecular weight of the compounds (MW) was a critical parameter which should be considered in the construction of such curves. With a MW around 1000 g mol(-1), efficiencies as high as 300,000 plates could be theoretically attained using UHPLC at 30 degrees C. By limiting the column length to 450 mm, the maximal plate count was around 100,000. In gradient mode, the longest column does not provide the maximal peak capacity for a given analysis time in UHPLC. This was attributed to the fact that peak capacity is not only related to the plate number but also to column dead time. Therefore, a compromise should be found and a 150 mm column should be preferentially selected for gradient lengths up to 60 min at 30 degrees C, while the columns coupled in series (3x 150 mm) were attractive only for t(grad)>250 min. Compared to 30 degrees C, peak capacities were increased by about 20-30% for a constant gradient length at 90 degrees C and gradient time decreased by 2-fold for an identical peak capacity.

Opposite effect of counterions on the persistence length of nicked and non-nicked DNA.

Using cryo-electron microscopy we reconstructed the three-dimensional trajectories adopted in cryovitrified solutions by double-stranded DNA molecules in which the backbone of one strand lacked a phosphate at regular intervals of 20 nucleotides. The shape of such nicked DNA molecules was compared with that of DNA molecules with exactly the same sequence but without any single-stranded scissions. Upon changing the salt concentration we observed opposite effects of charge neutralization on nicked and non-nicked DNA. In low salt solutions (10 mM Tris-HCl, 10 mM NaCl) the applied dense nicking caused ca 3.5-fold reduction of the DNA persistence length as compared with non-nicked DNA. Upon increasing the salt concentration (to 150 mM NaCl and 10 mM MgCl2) the persistence length of non-nicked DNA appreciably decreased while that of nicked DNA molecules increased by a factor of 2.

Optimisation de la cryo microscopie électronique pour les études des minicercles d'ADN

RESUME : Bien que les propriétés physiques de la structure de l'ADN aient été intensivement étudiées pendant plus de 50 ans il y a encore beaucoup de questions importantes qui attendent des réponses. Par exemple, qu'arrive-t-il à la structure de la double hélice d'ADN nue (sans protéines liées) lorsqu'elle est fortement courbée, de la même manière que dans les nucléosomes? Cet ADN nu est-il facilement plié (il reste dans le régime élastique) ou réduit-il la contrainte de flexion en formant des sites hyperflexibles «kinks» (il sort du régime élastique en cassant l'empilement des paires de bases à certains endroits) ? La microscopie électronique peut fournir une réponse à cette question par visualisation directe des minicercles d'ADN de la longueur d'un tour de nucléosome (environ 90 paires de bases). Pour que la réponse soit scientifiquement valide, on doit observer les molécules d'ADN lorsqu'elles sont en suspension dans la solution d'intérêt et sans que des colorations, produits chimiques ou fixatifs n'aient été ajoutés, étant donné que ceux-ci peuvent changer les propriétés de l'ADN. La technique de la cryo-microscopie électronique (cryo-EM) développée par le groupe de Jacques Dubochet au début des années 80, permet la visualisation directe des molécules d'ADN suspendues dans des couche minces vitrifiées de solutions aqueuses. Toutefois, le faible contraste qui caractérise la cryo-EM combinée avec la très petite taille des minicercles d'ADN rendent nécessaire l'optimisation de plusieurs étapes, aussi bien dans la préparation des échantillons que dans le processus d'acquisition d'images afin d'obtenir deux clichés stéréo qui permettent la reconstruction 3-D des minicercles d'ADN. Dans la première partie de ma thèse, je décris l'optimisation de certains paramètres pour la cryoEM et des processus d'acquisition d'image utilisant comme objets de test des plasmides et d'autres molécules d'ADN. Dans la deuxième partie, je .décris comment j'ai construit les minicercles d'ADN de 94 bp et comment j'ai introduit des modifications structurelles comme des coupures ou des lacunes. Dans la troisième partie, je décris l'analyse des reconstructions des rninicercles d'ADN. Cette analyse, appuyée par des tests biochimiques, indique fortement que des molécules d'ADN sont capables de former de petites molécules circulaires de 94 bp sans dépasser les limites d'élasticité, indiquant que les minicercles adoptent une forme circulaire régulière où la flexion est redistribuée le long la molécule. ABSTRACT : Although physical properties of DNA structure have been intensively studied for over 50 years there are still many important questions that need to be answered. For example, what happens to protein-free double-stranded DNA when it is strongly bent, as in DNA forming nucleosomes? Is such protein-free DNA smoothly bent (i.e. it remains within elastic limits of DNA rigidity) or does it release its bending stress by forming sharp kinks (i.e. it exits the elastic regime and breaks the stacking between neighbouring base-pairs in localized regions)? Electron microscopy can provide an answer to this question by directly visualizing DNA minicircles that have the size of nucleosome gyres (ca 90 bp). For the answer to be scientifically valid, one needs to observe DNA molecules while they are still suspended in the solution of interest and no staining chemicals or fixatives have been added since these can change the properties of the DNA. CryoEM techniques developed by Jacques Dubochet's group beginning in the 1980's permit direct visualization of DNA molecules suspended in cryo-vitrified layers of aqueous solutions. However, a relatively weak contrast of cryo-EM preparations combined with the very small size of the DNA minicircles made it necessary to optimize many of the steps and parameters of the cryo-EM specimen preparation and image acquisition processes in order to obtain stereo-pairs of images that permit the 3-D reconstruction of the observed DNA minicircles. In the first part of my thesis I describe the optimization of the cryo-EM preparation and the image acquisition processes using plasmid size DNA molecules as a test object. In the second part, I describe how I formed the 94 by DNA minicircles and how I introduced structural modifications like nicks or gaps. In the third part, I describe the cryo-EM analysis of the constructed DNA minicircles. That analysis, supported by biochemical tests, strongly indicates that DNA minicircles as small as 94 by remain within the elastic limits of DNA structure, i.e. the minicircles adopt a regular circular shape where bending is redistributed along the molecules.

On a family of strongly regular graphs with λ = 1

Vegeu el resum a l'inici del document del fitxer adjunt.

A brief cognitive behavioural intervention for regular amphetamine users. A treatment guide.

A brief intervention using motivational and cognitive behavioural approaches to help change drug use. Also offer alternative brief interventions for clients not suited to the current approach. This manual is divided into five sections: Section 1. Context Key points from the National Drug Strategy Monograph No 51. Models of Intervention and Care for Psychostimulant Users are included to present the evidence supporting this type of intervention for regular amphetamine users.  A flow-chart to place the intervention in a treatment context. Section 2. Brief background to the study and summary of results of evaluation A brief description of how the study was developed, undertaken and evaluated. A brief description of the evaluation outcome data (detailed results will be published separately). Section 3. The intervention The CBT intervention is presented in a clear and easy to use format for practitioners. Section 4. Suggested alternative brief interventions for those not suitable for the current intervention This section provides an overview of recommendations for alternative interventions for psychostimulant users who are unsuitable for the CBT intervention (e.g. those who are not considering change, experimental users etc). Section 5. Other available resources This section lists a range of other resources that are currently available for practitioners working with psychostimulant users. This treatment guide has not been designed to stand alone. Rather, practitioners are encouraged to: 1. Acquaint themselves with the current research and clinical literature. The recently completed monograph Models of Intervention and Care for Psychostimulant Users is an excellent resource for current evidence supporting practice in this area. 2. Undertake training in CBT and motivational enhancement techniques if unfamiliar with these approaches. 3. Obtain ongoing clinical supervision.This resource was contributed by The National Documentation Centre on Drug Use.

Le football comme religion populaire et comme culture mondialisée : brèves notations en vue d'une interprétation critique d'une quasi-religion contemporaine

(Résumé de l'ouvrage) Le présent recueil d'hommages veut témoigner de l'importance de l'oeuvre théologique de Jean Richard, professeur à la Faculté de théologie et de sciences religieuses de l'Université Laval. Désireux de signifier leur reconnaissance au père Richard, les auteurs de ce livre ont proposé des textes s'inscrivant dans l'un ou l'autre de ses champs de recherche privilégiés. Le tableau des contributeurs à ces mélanges regroupe des théologiens de tous les âges, hommes et femmes, provenant du Canada, mais aussi des États-Unis et de l'Europe, de langue française, anglaise ou allemande, de confession catholique ou protestante, oeuvrant dans des champs disciplinaires aussi divers que la théologie systématique, la théologie fondamentale, l'éthique théologique, l'exégèse ou encore la philosophie. Cette diversité est révélatrice de la personnalité théologique du père Richard, du caractère international de son réseau d'amitiés et de recherche et de l'ampleur de son influence. Elle témoigne aussi de l'audace d'une oeuvre qui, entreprise dans les années 1960, a dès le départ relevé le défi de l'aggiornamento que venait de poser en toute urgence son Église et qui a très vite conduit son auteur « aux confins », pour reprendre - et pour cause - une expression de son mentor Paul Tillich qui lui sied à merveille. Les contributions réunies dans ce volume ne résultent pas d'un plan concerté. D'autant plus significatifs sont les recoupements thématiques qu'on y observe, qui, par un hasard seulement apparent, restituent les principaux axes de la production théologique du père Jean Richard. L'ouverture au présent et a ses problématiques propres, ainsi que les défis conceptuels par là posés à l'effort théologique constituent les deux constantes de ces contributions, comme de l'oeuvre qui les a inspirées.

Effectiveness of a nurse-led case management home care model in Primary Health Care. A quasi-experimental, controlled, multi-centre study

Background Demand for home care services has increased considerably, along with the growing complexity of cases and variability among resources and providers. Designing services that guarantee co-ordination and integration for providers and levels of care is of paramount importance. The aim of this study is to determine the effectiveness of a new case-management based, home care delivery model which has been implemented in Andalusia (Spain). Methods Quasi-experimental, controlled, non-randomised, multi-centre study on the population receiving home care services comparing the outcomes of the new model, which included nurse-led case management, versus the conventional one. Primary endpoints: functional status, satisfaction and use of healthcare resources. Secondary endpoints: recruitment and caregiver burden, mortality, institutionalisation, quality of life and family function. Analyses were performed at base-line, and at two, six and twelve months. A bivariate analysis was conducted with the Student's t-test, Mann-Whitney's U, and the chi squared test. Kaplan-Meier and log-rank tests were performed to compare survival and institutionalisation. A multivariate analysis was performed to pinpoint factors that impact on improvement of functional ability. Results Base-line differences in functional capacity – significantly lower in the intervention group (RR: 1.52 95%CI: 1.05–2.21; p = 0.0016) – disappeared at six months (RR: 1.31 95%CI: 0.87–1.98; p = 0.178). At six months, caregiver burden showed a slight reduction in the intervention group, whereas it increased notably in the control group (base-line Zarit Test: 57.06 95%CI: 54.77–59.34 vs. 60.50 95%CI: 53.63–67.37; p = 0.264), (Zarit Test at six months: 53.79 95%CI: 49.67–57.92 vs. 66.26 95%CI: 60.66–71.86 p = 0.002). Patients in the intervention group received more physiotherapy (7.92 CI95%: 5.22–10.62 vs. 3.24 95%CI: 1.37–5.310; p = 0.0001) and, on average, required fewer home care visits (9.40 95%CI: 7.89–10.92 vs.11.30 95%CI: 9.10–14.54). No differences were found in terms of frequency of visits to A&E or hospital re-admissions. Furthermore, patients in the control group perceived higher levels of satisfaction (16.88; 95%CI: 16.32–17.43; range: 0–21, vs. 14.65 95%CI: 13.61–15.68; p = 0,001). Conclusion A home care service model that includes nurse-led case management streamlines access to healthcare services and resources, while impacting positively on patients' functional ability and caregiver burden, with increased levels of satisfaction.

Compositional data analysis of archaeological glass: problems and possible solutions

Presentation in CODAWORK'03, session 4: Applications to archeometry

How Wages and Employment Adjust to Trade Liberalization: Quasi-Experimental Evidence from Austria

We study the response of regional employment and nominal wages to trade liberalization, exploiting the natural experiment provided by the opening of Central and Eastern European markets after the fall of the Iron Curtain in 1990. Using data for Austrian municipalities, we examine differential pre- and post-1990 wage and employment growth rates between regions bordering the formerly communist economies and interior regions. If the "border regions" are defined narrowly, within a band of less than 50 kilometers, we can identify statistically significant liberalization effects on both employment and wages. While wages responded earlier than employment, the employment effect over the entire adjustment period is estimated to be around three times as large as the wage effect. The implied slope of the regional labor supply curve can be replicated in an economic geography model that features obstacles to labor migration due to immobile housing and to heterogeneous locational preferences.

Binding of ²³⁹Pu and ⁹⁰Sr to organic colloids in soil solutions: evidence from a field experiment.

Colloidal transport has been shown to enhance the migration of plutonium in groundwater downstream from contaminated sites, but little is known about the adsorption of ⁹⁰Sr and plutonium onto colloids in the soil solution of natural soils. We sampled soil solutions using suction cups, and separated colloids using ultrafiltration to determine the distribution of ²³⁹Pu and ⁹⁰Sr between the truly dissolved fraction and the colloidal fraction of the solutions of three Alpine soils contaminated only by global fallout from the nuclear weapon tests. Plutonium was essentially found in the colloidal fraction (>80%) and probably associated with organic matter. A significant amount of colloidal ⁹⁰Sr was detected in organic-rich soil solutions. Our results suggest that binding to organic colloids in the soil solutions plays a key role with respect to the mobility of plutonium in natural alpine soils and, to a lesser extent, to the mobility of ⁹⁰Sr.