Scour Around Bridge Piers and Abutments, HR-30 and Iowa Highway Research Board Bulletin No. 4, 1956

Man’s never-ending search for better materials and construction methods and for techniques of analysis and design has overcome most of the early difficulties of bridge building. Scour of the stream bed, however, has remained a major cause of bridge failures ever since man learned to place piers and abutments in the stream in order to cross wide rivers. Considering the overall complexity of field conditions, it is not surprising that no generally accepted principles (not even rules of thumb) for the prediction of scour around bridge piers and abutments have evolved from field experience alone. The flow of individual streams exhibits a manifold variation, and great disparity exists among different rivers. The alignment, cross section, discharge, and slope of a stream must all be correlated with the scour phenomenon, and this in turn must be correlated with the characteristics of the bed material ranging from clays and fine silts to gravels and boulders. Finally, the effect of the shape of the obstruction itself-the pier or abutment-must be assessed. Since several of these factors are likely to vary with time to some degree, and since the scour phenomenon as well is inherently unsteady, sorting out the influence of each of the various factors is virtually impossible from field evidence alone. The experimental approach was chosen as the investigative method for this study, but with due recognition of the importance of field measurements and with the realization that the results must be interpreted so as to be compatible with the present-day theories of fluid mechanics and sediment transportation. This approach was chosen because, on the one hand, the factors affecting the scour phenomenon can be controlled in the laboratory to an extent that is not possible in the field, and, on the other hand, the model technique can be used to circumvent the present inadequate understanding of the phenomenon of the movement of sediment by flowing water. In order to obtain optimum results from the laboratory study, the program was arranged at the outset to include a related set of variables in each of several phases into which the whole problem was divided. The phases thus selected were : 1. Geometry of piers and abutments, 2. Hydraulics of the stream, 3. Characteristics of the sediment, 4. Geometry of channel shape and alignment.

Reporting a program evaluation: Needs, program plan, intervention, and decisions

The approach to intervention programs varies depending on the methodological perspective adopted. This means that health professionals lack clear guidelines regarding how best to proceed, and it hinders the accumulation of knowledge. The aim of this paper is to set out the essential and common aspects that should be included in any program evaluation report, thereby providing a useful guide for the professional regardless of the procedural approach used. Furthermore, the paper seeks to integrate the different methodologies and illustrate their complementarity, this being a key aspect in terms of real intervention contexts, which are constantly changing. The aspects to be included are presented in relation to the main stages of the evaluation process: needs, objectives and design (prior to the intervention), implementation (during the intervention), and outcomes (after the intervention). For each of these stages the paper describes the elements on which decisions should be based, highlighting the role of empirical evidence gathered through the application of instruments to defined samples and according to a given procedure.

Characterising the role of T-cell subsets in experimental allograft rejection and transplantation tolerance

SUMMARY : The recognition by recipient T cells of the allograft major histocompatibility complex (MHC)mismatched antigens is the primary event that ultimately leads to rejection. In the transplantation setting, circulating alloreactive CD4+ T cells play a central role in the initiation and the coordination of the immune response and can initiate the rejection of an allograft via three distinct pathways: the direct, indirect and the recently described semi-direct pathway. However, the exact role of individual CD4+ T-cell subsets in the development of allograft rejection is not clearly defined. Furthermore, besides pathogenic effector T cells, a new subset of T cells with regulatory properties, the CD4+CD25+Foxp3+ (Treg) cells, has come under increased scrutiny over the last decade. The experiments presented in this thesis were designed to better define the phenotype and functional characteristics of CD4+ T-cell subsets and Treg cells in vitro and in vivo in a marine adoptive transfer and skin transplantation model. As Treg cells play a key role in the induction and maintenance of peripheral transplantation tolerance, we have explored whether donor-antigen specific Treg cells could be expanded in vitro. Here we describe a robust protocol for the ex-vivo generation and expansion of antigen-specific Treg cells, without loss of their characteristic phenotype and suppressive function. In our in vivo transplantation model, antigen-specific Treg cells induced donor-specific tolerance to skin allografts in lymphopenic recipients and significantly delayed skin graft rejection in wild-type mice in the absence of any other immunosuppression. Naïve and memory CD4+ T cells have distinct phenotypes, effector functions and in vivo homeostatsis, and thus may play different roles in anti-donor immunity after transplantation. We have analyzed in vitro and in vivo primary alloresponses of naïve and cross-reactive memory CD4+ T cells. We found that the CD4+CD45RBlo memory T-cell pool was heterogeneous and contained cells with regulatory potentials, both in the CD4+CD25+ and CD4+CD25- populations. CD4+ T cells capable of inducing strong primary alloreactive responses in vitro and rejection of a first allograft in vivo were mainly contained within the CD45RBhi naïve CD4+ T-cell compartment. Taken together, the work described in this thesis provides new insights into the mechanisms that drive allograft rejection or donor-specific transplantation tolerance. These results will help to optimise current clinical immunosuppressive regimens used after solid organ transplantation and design new immunotherapeutic strategies to prevent transplant rejection. RÉSUMÉ : ROLE DES SOUS-POPULATIONS DE CELLULES T DANS LE REJET DE GREFFE ET L'INDUCTION DE TOLERANCE EN TRANSPLANTATION La reconnaissance par les cellules T du receveur des alloantigènes du complexe majeur d'histocompatibilité (CMIT) présentés par une greffe allogénique, est le premier événement qui aboutira au rejet de l'organe greffé. Dans le contexte d'une transplantation, les cellules alloréactives T CD4+ circulantes jouent un rôle central dans l'initiation et la coordination de 1a réponse immune, et peuvent initier le rejet par 3 voies distinctes : la voie directe, indirecte et la voie servi-directe, plus récemment décrite. Toutefois, le rôle exact des sous-populations de cellules T CD4+ dans les différentes étapes menant au rejet d'une allogreffe n'est pas clairement établi. Par ailleurs, hormis les cellules T effectrices pathogéniques, une sous-population de cellules T ayant des propriétés régulatrices, les cellules T CD4+CD25+Foxp3+ (Treg), a été nouvellement décrite et est intensément étudiée depuis environ dix ans. Les expériences présentées dans cette thèse ont été planifiées afin de mieux définir le phénotype et les caractéristiques fonctionnels des sous-populations de cellules T CD4+ et des Treg in vitro et in vivo dans un modèle marin de transfert adoptif de cellules et de transplantation de peau. Comme les cellules Treg jouent un rôle clé dans l'induction et le maintien de la tolérance périphérique en transplantation, nous avons investigué la possibilité de multiplier in vitro des cellules Treg avec spécificité antigénique pour le donneur. Nous décrivons ici un protocole reproductible pour la génération et l'expansion ex-vivo de cellules Treg avec spécificité antigénique, sans perte de leur phénotype caractéristique et de leur fonction suppressive. Dans notre modèle in vivo de transplantation de peau, ces cellules Treg pouvaient induire une tolérance spécifique vis-à-vis du donneur chez des souris lymphopéniques, et, chez des souris normales non-lymphopéniques ces Treg ont permis de retarder significativement le rejet en l'absence de tout traitement immunosuppresseur. Les cellules T CD4+ naïves et mémoires se distinguent par leur phénotype, fonction effectrice et leur homéostasie in vivo, et peuvent donc moduler différemment la réponse immune contre le donneur après transplantation. Nous avons analysé in vitro et in vivo les réponses allogéniques primaires de cellules T CD4+ naïves et mémoires non-spécifiques (cross-réactives). Nos résultats ont montré que le pool de cellules T CD4+CD45RB'° mémoires était hétérogène et contenait des cellules avec un potentiel régulateur, aussi bien parmi la sous-population de cellules CD4+CD25+ que CD4+CD25+. Les cellules T CD4+ capables d'induire une alloréponse primaire intense in vitro et le rejet d'une première allogreffe in vivo étaient essentiellement contenues dans le pool de cellules T CD4+CD45RBhi naïves. En conclusion, le travail décrit dans cette thèse amène un nouvel éclairage sur les mécanismes responsables du rejet d'une allogreffe ou de l'induction de tolérance en transplantation. Ces résultats permettront d'optimaliser les traitements immunosuppresseurs utilisés en transplantation clinique et de concevoir des nouvelles stratégies irnmuno-thérapeutiques pour prévenir le rejet de greffe allogénique.

No longitudinal mitochondrial DNA sequence changes in HIV-infected individuals with and without lipoatrophy.

The potential for mitochondrial (mt) DNA mutation accumulation during antiretroviral therapy (ART), and preferential accumulation in patients with lipoatrophy compared with control participants, remains controversial. We sequenced the entire mitochondrial genome, both before ART and after ART exposure, in 29 human immunodeficiency virus (HIV)-infected Swiss HIV Cohort Study participants initiating a first-line thymidine analogue-containing ART regimen. No accumulation of mtDNA mutations or deletions was detected in 13 participants who developed lipoatrophy or in 16 control participants after significant and comparable ART exposure (median duration, 3.3 and 3.7 years, respectively). In HIV-infected persons, the development of lipoatrophy is unlikely to be associated with accumulation of mtDNA mutations detectable in peripheral blood.

Usability of Virtual Museums and the Diffusion of Cultural Heritage

Les prioritats per als museus canvien. La missió de la nova museologia és convertir els museus en llocs per a gaudir i aprendre, cosa que fa que hagin de dur a terme una gestió financera molt semblant a la d'una empresa social que competeixi en el sector del lleure. Amb el pas del temps, els museus han d'establir i aplicar els criteris necessaris per a la supervivència, aplanant el terreny perquè altres institucions públiques siguin més obertes en els seus esforços per comunicar i difondre el seu patrimoni. Ja podem començar a parlar d'algunes conclusions comunament acceptades sobre el comportament dels visitants, que són necessàries per a planificar exposicions futures que vegin l'aprenentatge com un procés constructiu, les col·leccions com a objectes amb significat i les mateixes exposicions com a mitjans de comunicació que haurien de transformar la manera de pensar de l'espectador i que estan al servei del mateix missatge. Sembla que internet representa un mitjà efectiu per a assolir aquests objectius, ja que és capaç (a) d'adaptar-se als interessos i les característiques intel·lectuals d'un públic divers; (b) de redescobrir els significats dels objectes i adquirir un reconeixement sociocultural del seu valor per mitjà del seu potencial interactiu, i (c) de fer ús d'elements atractius i estimulants perquè tothom en gaudeixi. Per a aquest propòsit, és bàsic fer-nos les preguntes següents: quins criteris ha de seguir un museu virtual per a optimar la difusió del seu patrimoni?; quins elements estimulen els usuaris a quedar-se en una pàgina web i fer visites virtuals que els siguin satisfactòries?; quin paper té la usabilitat de l'aplicació en tot això?

Agenda deportiva

Aquesta memòria recull el procés seguit per al desenvolupament i implementació d’una aplicació Software. Aquest procés s’inicia amb la presentació del tema, estat de l’art i planificació temporal per continuar amb l’anàlisi de requeriments de l’aplicació —identificació dels interessats, entitats existents i les relacions d’aquestes...— el disseny de la mateixa —mètode de desenvolupament emprat, arquitectura...— la implementació de l’aplicació i les proves corresponents. Finalment la memòria es completa amb les conclusions i vies de continuació així com la bibliografia i annexos complementaris.

Gallery districts of Barcelona: the strategic play of art dealers

This article focuses on Barcelona"s art market to explore the underlying factors behind the clustering of art dealers in several of the city"s districts. Drawing upon quantitative and qualitative data, the article analyses how such clustering reveals a strategic action in the sense attributed to it by Crozier and Friedberg (1981). Gallery districts are not a reflection of structural factors (economic, urban development-related or social) but the result of a combination of strategic choices either individual or collective which explain the permanence of leading gallery districts or the emergence of new ones.

Right ventricular dysfunction in children and adolescents conceived by assisted reproductive technologies.

Assisted reproductive technologies (ART) predispose the offspring to vascular dysfunction, arterial hypertension, and hypoxic pulmonary hypertension. Recently, cardiac remodeling and dysfunction during fetal and early postnatal life have been reported in offspring of ART, but it is not known whether these cardiac alterations persist later in life and whether confounding factors contribute to this problem. We, therefore, assessed cardiac function and pulmonary artery pressure by echocardiography in 54 healthy children conceived by ART (mean age 11.5 ± 2.4 yr) and 54 age-matched (12.2 ± 2.3 yr) and sex-matched control children. Because ART is often associated with low birth weight and prematurity, two potential confounders associated with cardiac dysfunction, only singletons born with normal birth weight at term were studied. Moreover, because cardiac remodeling in infants conceived by ART was observed in utero, a situation associated with increased right heart load, we also assessed cardiac function during high-altitude exposure, a condition associated with hypoxic pulmonary hypertension-induced right ventricular overload. We found that, while at low altitude cardiac morphometry and function was not different between children conceived by ART and control children, under the stressful conditions of high-altitude-induced pressure overload and hypoxia, larger right ventricular end-diastolic area and diastolic dysfunction (evidenced by lower E-wave tissue Doppler velocity and A-wave tissue Doppler velocity of the lateral tricuspid annulus) were detectable in children and adolescents conceived by ART. In conclusion, right ventricular dysfunction persists in children and adolescents conceived by ART. These cardiac alterations appear to be related to ART per se rather than to low birth weight or prematurity.

Characteristics of 2D convective structures in Catalonia (NE Spain): an analysis using radar data and GIS

Flood simulation studies use spatial-temporal rainfall data input into distributed hydrological models. A correct description of rainfall in space and in time contributes to improvements on hydrological modelling and design. This work is focused on the analysis of 2-D convective structures (rain cells), whose contribution is especially significant in most flood events. The objective of this paper is to provide statistical descriptors and distribution functions for convective structure characteristics of precipitation systems producing floods in Catalonia (NE Spain). To achieve this purpose heavy rainfall events recorded between 1996 and 2000 have been analysed. By means of weather radar, and applying 2-D radar algorithms a distinction between convective and stratiform precipitation is made. These data are introduced and analyzed with a GIS. In a first step different groups of connected pixels with convective precipitation are identified. Only convective structures with an area greater than 32 km2 are selected. Then, geometric characteristics (area, perimeter, orientation and dimensions of the ellipse), and rainfall statistics (maximum, mean, minimum, range, standard deviation, and sum) of these structures are obtained and stored in a database. Finally, descriptive statistics for selected characteristics are calculated and statistical distributions are fitted to the observed frequency distributions. Statistical analyses reveal that the Generalized Pareto distribution for the area and the Generalized Extreme Value distribution for the perimeter, dimensions, orientation and mean areal precipitation are the statistical distributions that best fit the observed ones of these parameters. The statistical descriptors and the probability distribution functions obtained are of direct use as an input in spatial rainfall generators.

Protein pocket and ligand shape comparison and its application in virtual screening.

Understanding molecular recognition is one major requirement for drug discovery and design. Physicochemical and shape complementarity between two binding partners is the driving force during complex formation. In this study, the impact of shape within this process is analyzed. Protein binding pockets and co-crystallized ligands are represented by normalized principal moments of inertia ratios (NPRs). The corresponding descriptor space is triangular, with its corners occupied by spherical, discoid, and elongated shapes. An analysis of a selected set of sc-PDB complexes suggests that pockets and bound ligands avoid spherical shapes, which are, however, prevalent in small unoccupied pockets. Furthermore, a direct shape comparison confirms previous studies that on average only one third of a pocket is filled by its bound ligand, supplemented by a 50 % subpocket coverage. In this study, we found that shape complementary is expressed by low pairwise shape distances in NPR space, short distances between the centers-of-mass, and small deviations in the angle between the first principal ellipsoid axes. Furthermore, it is assessed how different binding pocket parameters are related to bioactivity and binding efficiency of the co-crystallized ligand. In addition, the performance of different shape and size parameters of pockets and ligands is evaluated in a virtual screening scenario performed on four representative targets.

'Fast-implantable' aortic valve implantation and concomitant mitral procedures.

Concomitant aortic and mitral valve replacement or concomitant aortic valve replacement and mitral repair can be a challenge for the cardiac surgeon: in particular, because of their structure and design, two bioprosthetic heart valves or an aortic valve prosthesis and a rigid mitral ring can interfere at the level of the mitroaortic junction. Therefore, when a mitral bioprosthesis or a rigid mitral ring is already in place and a surgical aortic valve replacement becomes necessary, or when older high-risk patients require concomitant mitral and aortic procedures, the new 'fast-implantable' aortic valve system (Intuity valve, Edwards Lifesciences, Irvine, CA, USA) can represent a smart alternative to standard aortic bioprosthesis. Unfortunately, this is still controversial (risk of interference). However, transcatheter aortic valve replacements have been performed in patients with previously implanted mitral valves or mitral rings. Interestingly, we learned that there is no interference (or not significant interference) among the standard valve and the stent valve. Consequently, we can assume that a fast-implantable valve can also be safely placed next to a biological mitral valve or next to a rigid mitral ring without risks of distortion, malpositioning, high gradient or paravalvular leak. This paper describes two cases: a concomitant Intuity aortic valve and bioprosthetic mitral valve implantation and a concomitant Intuity aortic valve and mitral ring implantation.

The HIV care cascade in Switzerland: reaching the UNAIDS/WHO targets for patients diagnosed with HIV.

OBJECTIVES: To describe the HIV care cascade for Switzerland in the year 2012. DESIGN/METHODS: Six levels were defined: (i) HIV-infected, (ii) HIV-diagnosed, (iii) linked to care, (iv) retained in care, (v) on antiretroviral treatment (ART), and (vi) with suppressed viral load. We used data from the Swiss HIV Cohort Study (SHCS) complemented by a nationwide survey among SHCS physicians to estimate the number of HIV-patients not registered in the cohort. We also used Swiss ART sales data to estimate the number of patients treated outside the SHCS network. Based on the number of patients retained in care, we inferred the estimates for levels (i) to (iii) from previously published data. RESULTS: We estimate that (i) 15 200 HIV-infected individuals lived in Switzerland in 2012 (margins of uncertainty, 13 400-19 300). Of those, (ii) 12 300 (81%) were diagnosed, (iii) 12 200 (80%) linked, and (iv) 11 900 (79%) retained in care. Broadly based on SHCS network data, (v) 10 800 (71%) patients were receiving ART, and (vi) 10 400 (68%) had suppressed (<200 copies/ml) viral loads. The vast majority (95%) of patients retained in care were followed within the SHCS network, with 76% registered in the cohort. CONCLUSION: Our estimate for HIV-infected individuals in Switzerland is substantially lower than previously reported, halving previous national HIV prevalence estimates to 0.2%. In Switzerland in 2012, 91% of patients in care were receiving ART, and 96% of patients on ART had suppressed viral load, meeting recent UNAIDS/WHO targets.

DFM(A)- aspects for a fixed electrical attenuator design

The goal of this paper is to describe a complete and extensive prototype design of a fixed electrical attenuator. The paper starts by describing the function and by giving some basic information about the attenuators. After a comprehensive description of the component, the facts of reverse engineering are discussed. The method itself is applied to ease manufacturing and design stages of this component. Information about materials and applied manufacturing technologies are also included in this report. By applying some specified DFMA-aspects the final design turned out to be a potential prototype device to be manufactured and for further analyse.

On Transmission System Design for Wireless Broadcasting

This thesis considers aspects related to the design and standardisation of transmission systems for wireless broadcasting, comprising terrestrial and mobile reception. The purpose is to identify which factors influence the technical decisions and what issues could be better considered in the design process in order to assess different use cases, service scenarios and end-user quality. Further, the necessity of cross-layer optimisation for efficient data transmission is emphasised and means to take this into consideration are suggested. The work is mainly related terrestrial and mobile digital video broadcasting systems but many of the findings can be generalised also to other transmission systems and design processes. The work has led to three main conclusions. First, it is discovered that there are no sufficiently accurate error criteria for measuring the subjective perceived audiovisual quality that could be utilised in transmission system design. Means for designing new error criteria for mobile TV (television) services are suggested and similar work related to other services is recommended. Second, it is suggested that in addition to commercial requirements there should be technical requirements setting the frame work for the design process of a new transmission system. The technical requirements should include the assessed reception conditions, technical quality of service and service functionalities. Reception conditions comprise radio channel models, receiver types and antenna types. Technical quality of service consists of bandwidth, timeliness and reliability. Of these, the thesis focuses on radio channel models and errorcriteria (reliability) as two of the most important design challenges and provides means to optimise transmission parameters based on these. Third, the thesis argues that the most favourable development for wireless broadcasting would be a single system suitable for all scenarios of wireless broadcasting. It is claimed that there are no major technical obstacles to achieve this and that the recently published second generation digital terrestrial television broadcasting system provides a good basis. The challenges and opportunities of a universal wireless broadcasting system are discussed mainly from technical but briefly also from commercial and regulatory aspect