Temporal diffeomorphic free-form deformation: application to motion and strain estimation from 3D echocardiography

This paper presents a new registration algorithm, called Temporal Di eomorphic Free Form Deformation (TDFFD), and its application to motion and strain quanti cation from a sequence of 3D ultrasound (US) images. The originality of our approach resides in enforcing time consistency by representing the 4D velocity eld as the sum of continuous spatiotemporal B-Spline kernels. The spatiotemporal displacement eld is then recovered through forward Eulerian integration of the non-stationary velocity eld. The strain tensor iscomputed locally using the spatial derivatives of the reconstructed displacement eld. The energy functional considered in this paper weighs two terms: the image similarity and a regularization term. The image similarity metric is the sum of squared di erences between the intensities of each frame and a reference one. Any frame in the sequence can be chosen as reference. The regularization term is based on theincompressibility of myocardial tissue. TDFFD was compared to pairwise 3D FFD and 3D+t FFD, bothon displacement and velocity elds, on a set of synthetic 3D US images with di erent noise levels. TDFFDshowed increased robustness to noise compared to these two state-of-the-art algorithms. TDFFD also proved to be more resistant to a reduced temporal resolution when decimating this synthetic sequence. Finally, this synthetic dataset was used to determine optimal settings of the TDFFD algorithm. Subsequently, TDFFDwas applied to a database of cardiac 3D US images of the left ventricle acquired from 9 healthy volunteers and 13 patients treated by Cardiac Resynchronization Therapy (CRT). On healthy cases, uniform strain patterns were observed over all myocardial segments, as physiologically expected. On all CRT patients, theimprovement in synchrony of regional longitudinal strain correlated with CRT clinical outcome as quanti ed by the reduction of end-systolic left ventricular volume at follow-up (6 and 12 months), showing the potential of the proposed algorithm for the assessment of CRT.

Spectral efficiency in reference-signal-assisted low-power wireless communication

Expressions relating spectral efficiency, power and Doppler spectrum are derived for low-power Rayleighfaded wireless channels with proper complex signaling. Noside information on the state of the channel is assumed at the receiver. Rather, periodic reference signals are postulated inaccordance with the functioning of most wireless systems. In contrast with most previous studies, which relied on block-fading channel models, a continuous-fading model is adopted. This embeds the Doppler spectrum directly in thederived expressions thereby imbuing them with practical significance.

Film's frame

A partir de un acto interactivo con la wwww.aeat.es, el usuario envía telemáticamente el modelo 100 en un entorno con tendencia a la incertidumbre y a las dificultades de usabilidad, sin embargo, la investigación pretende demostrar que en dicho acto, el usuario construye una historia narrativa debido a la existencia de una motivación y a la tendencia connatural a la representación narrativa, a pesar que la web no fue intencionalmente construida con propósitos narrativos. El estudio, además, enfoca la interacción como un acto inmersivo y reconoce en la incertidumbre las variables que determinan la continuidad y rumbo del relato. La investigación propone un modelo interpretativo para el análisis y la estructuración del espacio y la historia implícita. Y a nivel exploratorio, se propone la aplicación del Mouse Tracking como técnica científica.

The impact of the reference price system on the pharmaceutical market: A theoretical approach

This article analyses the impact of the reference pricesystem on the price-setting strategies of thepharmaceutical firms and on the level of generic usage.This model is the first to take explicitly into accountthe impact of the reference price mechanism on the levelof competition between brand-name and generic drugs andnational pharmaceutical spending. We consider aduopolistic model with one firm producing the brand-namedrug, whose patent has already expired, and the otherproducing the corresponding generic version. We work ina partial equilibrium framework where firms set pricessequentially and consumers face heterogeneous switchingcosts.We show that brand producers compensate thedecline of profits by selling greater quantities insteadof charging higher prices, thus fostering pricecompetition in the pharmaceutical market. This result isa consequence of both the assumption of a verticallydifferentiated model and the introduction of thereference price system.

Review of the literature on reference pricing

This paper reviews the literature on reference pricing (RP) in pharmaceutical markets. The RP strategy for cost containment of expenditure on drugs is analyzed as part of the procurement mechanism. We review the existing literature and the state-of-the-art regarding RP by focusing on its economic effects. In particular, we consider: (1) the institutional context and problem-related factors which appear to underline the need to implement an RP strategy; i.e., its nature, characteristics and the sort of health care problems commonly addressed; (2) how RP operates in practice; that is, how third party-payers (the insurers/buyers) have established the RP systems existing on the international scene (i.e., information methods, monitoring procedures and legislative provisions); (3)the range of effects resulting from particular RP strategies (including effects on choice of appropriate pharmaceuticals, insurer savings, total drug expenditures, prices of referenced and non-referenced products and dynamic efficiency; (4) the market failures which an RP policy is supposed to address and the main advantages and drawbacks which emerge from an analysis of its effects. Results suggest that RP systems achieve better their postulated goals (1) if cost inflation in pharmaceuticals is due to high prices rather than to the excess of prescription rates, (2) when the larger is the existing difference in prices among equivalent drugs, and (3) more important is the actual market for generics.

The impact of generic reference pricing interventions in the statin market

The objective of this study was to evaluate the intended and unintended impact on pharmaceutical use and sales of three public financing reforms applied to the prescription of statins: a Spanish generic reference pricing (RP) system for lovastatin and simvastatin, and two competing policies introduced by the Andalusian Public Health Service (APHS) for all statins, first a maximum consumer price (MCP) and then a so called quality prescribing incentive for general practitioners (MCP plus PI).This study is designed as an observational, retrospective, interrupted time series analysis with comparison series (APHS and the rest of Spain) of 46 monthly drug use and sales ratios from January 2001 to October 2004 for each active ingredient in the group of statins.RP has been effective at reducing the volume of sales growth of the off-patent statins, yet its overall impact on sales of all statins has been relatively modest. The quantity and volume of sales impact heavily depends on regulatory RP details such as when the system is introduced, how often it is updated, and how the reference price is calculated.

A theory of reference-dependent behavior

Extensive field and experimental evidence in a variety of environments show that behavior depends on a reference point. This paper provides an axiomatic characterization of this dependence. We proceed by imposing gradually more structure on both choice correspondences and preference relations, requiring increasingly higher levels of rationality, and freeing the decision-maker from certain types of inconsistencies. The appropriate degree of behavioral structure will depend on the phenomenon that is to be modeled. Lastly, we provide two applications of our work: one to model the status-quo bias, and another to model addictive behavior.

Security analysts as frame-makers

In this paper we explore the mechanisms that allow securities analysts to value companies in contexts of Knightian uncertainty, that is, in the face of information that is unclear, subject to unforeseeable contingencies or to multiple interpretations. We address this question with a grounded-theory analysis of the reports written on Amazon.com by securities analyst Henry Blodget and rival analysts during the years 1998-2000. Our core finding is that analysts' reports are structured by internally consistent associations that includecategorizations, key metrics and analogies. We refer to these representations as calculative frames, and propose that analysts function as frame-makers - that is, asspecialized intermediaries that help investors value uncertain stocks. We conclude by considering the implications of frame-making for the rise of new industry categories, analysts' accuracy, and the regulatory debate on analysts'independence.

Restoration of a lost geological reference point: the loggingstone of Pedralta (Girona, Spain)

The Pedralta is a loggingstone formed of monzonitic leucogranites, which has a volume of about 38 m3 and weighs 101 tons. After its fall in December 1996, a public subscription was opened to meet the expenses of the restoration work, which was completed in May 1999

Modeval2 Reference Manual

El Projecte MODEVAL respon a la necessitat detectada en matèria d'avaluació de competències bàsiques de les persones, i tracta de definir quins són els nivells bàsics d'habilitats que garanteixen unes condicions individuals favorables per al desenvolupament de la persona, la ciutadania activa, i la integració social, cultural i professional dels individus. Mentre el projecte MODEVAL 1 tenia com a objectiu realitzar un marc de referència metodològic a nivell europeu per a dur a terme l'avaluació de competències; el projecte MODEVAL 2, és a dir, el present treball, té com a objectiu la creació de mòduls de formació per als diferents interessats (és a dir, formadors d'alfabetització i de formació bàsica, investigadors, coordinadors de centres de formació, els responsables polítics, estadístics, persones que realitzaran enquestes a gran escala sobre el coneixement de base, etc.) per tal d'aplicar les recomanacions del projecte i crear les seves pròpies eines d'avaluació.

Modeval2 Manuel de Reference

El Projecte MODEVAL respon a la necessitat detectada en matèria d'avaluació de competències bàsiques de les persones, i tracta de definir quins són els nivells bàsics d'habilitats que garanteixen unes condicions individuals favorables per al desenvolupament de la persona, la ciutadania activa, i la integració social, cultural i professional dels individus. Mentre el projecte MODEVAL 1 tenia com a objectiu realitzar un marc de referència metodològic a nivell europeu per a dur a terme l'avaluació de competències; el projecte MODEVAL 2, és a dir, el present treball, té com a objectiu la creació de mòduls de formació per als diferents interessats (és a dir, formadors d'alfabetització i de formació bàsica, investigadors, coordinadors de centres de formació, els responsables polítics, estadístics, persones que realitzaran enquestes a gran escala sobre el coneixement de base, etc.) per tal d'aplicar les recomanacions del projecte i crear les seves pròpies eines d'avaluació.

A Reply to comments by D. Bar-Yosef M. Stiner on "Prehistoric exploitation of marine resources in Southern Africa with particular reference to shellfish gathering: opportunities and continuities"

I am very grateful to Daniella E. Bar-Yosef Mayer and Mary Stiner for their comments on an article I published in the previous issue of Pyrenae. Having spent many years working with coastal sites in South Africa and now settling in the Mediterranean academic landscape, I value the feedback from these two well-known archaeologists who have dedicated years of hard work in this later part of the world. Their opinions are very much appreciated for they allow me to bring new contexts to some of the (old) questions I have pursued in South Africa, an exercise that would help me with the process of broadening my research interests to the Mediterranean region.

La salut reproductiva de la dona immigrant: una anàlisi des de la influència cultural

El progressiu increment del flux migratori en els darrers anys a Catalunya genera un major percentatge de dones en estat fèrtil que requereixen d’una atenció vinculada a la seva salut reproductiva. D’aquesta manera, els professionals sanitaris es veuen sotmesos a treballar sota una diversitat cultural que moltes vegades genera un “xoc intercultural” dificultant la relació assistencial entre professional i usuari. Per aquest motiu, el següent estudi pretén donar una aproximació de la influència cultural de la dona immigrant (marroquina i subsahariana) en quatre àmbits: embaràs, part, post-part i maternitat.Hipòtesis: S’identifiquen necessitats bàsiques assistencials no resoltes satisfactòriament en el grup de dones immigrants (marroquines i subsaharianes) en el període del part, puerperi immediat i intermedi, a més d’un impacte intercultural associat.Objectiu principal: Conèixer les vivències, percepcions i conductes de les dones marroquines i subsaharianes en l’embaràs, el part, el post-part, la maternitat dins el seu marc cultural i com influeixen en l’atenció sanitària del nostre país.Material i mètodes: S’ha realitzat un estudi de disseny mixt. Per una banda s’ha disposat d’una metodologia qualitativa descriptiva que utilitza la teoria fonamentada “Grounded Theory” com a instrument metodològic, i per l’altra, s’ha optat per una metodologia quantitativa per analitzar les dades clíniques i epidemiològiques de gestants immigrants que havien donat a llum al Servei d’Obstetrícia-Sala de Parts de l’Hospital Sta. Caterina (Girona), durant el període comprès entre el mes de novembre de 2012 i gener de 2013.La recollida de dades s’ha realitzat sota una entrevista semiestructurada i una observació participant com a instruments qualitatius, i el suport del “carnet de l’embaràs” i la “història obstètrica” de cada dona per elaborar l’estudi quantitatiu. Pel que fa a l’anàlisi de les dades en l’estudi qualitatiu s’ha seguit el procés analític plantejat per la Teoria fonamentada i en el cas de l’estudi quantitatiu, s’ha comptatamb el suport d’una tesi doctoral per comparar els resultats amb els de les dones autòctones, dels quals fa referència la tesi.Resultats: En l’estudi qualitatiu, s’han trobat especificitats culturals en relació a la percepció del part, desenvolupament del part ( a nivell conductual), implicació en el post-part, valoració de l’atenció sanitària rebuda i el concepte de maternitat. Pel que fa a l’estudi quantitatiu comparatiu, s’han indentificat diferències entre el col·lectiu de la mostra estudiada i les dones autòctones referent als antecedents obstètrics i paritat, al control gestacional i al desenvolupament del part ( a nivell fisiològic)