Regulatory focus theory is a motivational orientation theory encompassing two regulatory systems: promotion focus and prevention focus. Promotion focused individuals tend to seek success, implement risky tactics, and an eager goal pursuit. Prevention focused individuals tend to avoid failure, implement conservative tactics, and a vigilant goal pursuit. Scholer and Higgins (2011) propose an exception to the rule where individuals break the natural RF alignment, which individuals typically seek to maintain. Scholer and Higgins (2011) proposed that promotion (prevention) focused individuals in a state of gain (loss) become conservative (riskier) in their behavior while maintaining an eager (vigilant) goal pursuit. However, literature supporting this theory is between-subjects in methodology and does not measure GP strategy, only risk. The current study proposes two competing regulation patterns: 1) When individuals change in their risk, they maintain their GP strategy 2) when individuals change in their risk, their GP strategy also changes, becoming more eager with higher levels of risk and more vigilant with more conservative behavior. Therefore, the following study examined how tactics and GP strategies change within-person when experiencing loss and gain states. Specifically, examining change in risk and GP after positive and negative goal discrepancy feedback. In order to examine this self-regulation, participants who were primed to be in either a promotion or prevention focused state played three rounds of a simple risk-measuring game. Even though the RF prime did not produce the expected results, there was regulation occurring. After recategorizing the baseline risk and GP to create a high risk /eager GP and a low risk /vigilant GP groups, there was support for the idea that as behavior changes to be riskier, so too does GP change to become more eager. This finding is in contradiction to Scholer and Higgins' (2011) theory that there is a cognitive reappraisal of what it means to be risky, such that it can fit within the vigilant goal pursuit strategy. Additionally, latent profile analyses further supported the second of the competing regulation patterns, in that higher risk-taking corresponded with eager GP, and more conservative behaviors led to greater levels of vigilant GP. Future directions and limitations are discussed. / Doctor of Philosophy / Regulatory focus theory has two motivational orientations: promotion focus encompassing those who seek success and avoid the absence of success and prevention focus encompassing those who avoid failure and seek the absence of failure. Scholer and Higgins (2011) describe a level approach to regulatory focus where individuals typically seek alignment throughout these levels. However, they note an exception to the rule where individuals implement tactics incongruent with their current regulatory focus system. They propose that individuals maintain this incongruency by cognitively redefining the tactics to align with the current regulatory focus system. Drawing from this exception to the rule, and from Lord et al.'s (2010) self-regulation model, two competing self-regulation patterns were examined: 1) When individuals change in their risk behaviors, they maintain their current regulatory focus system 2) when individuals change in their risk behaviors, it causes bottom-up self-regulation and changes individuals' regulatory focus system to match the risk behavior. In order to test these competing regulation patterns, participants completed a writing task meant to place them in either a promotion or prevention regulatory focus state. They then played three rounds of a simple risk-measuring game. In addition, after each round of the game, the participants' goal pursuit strategies were measured to see if the general strategy changed as risk behaviors changed. In order to necessitate a change in in levels of risk, between rounds, participants were given negative and positive feedback (in a random order). Negative feedback was meant to cause individuals to be risky and positive feedback was meant to lead to more conservative behaviors from the participants. Results indicated the regulatory focus prime did not work, however, after examining exploratory analyses, there was some support for the idea that individuals implement self-regulation in order for their regulatory focus system to match their behaviors.

Yes / In China there is a cultural expectation (Xiao, -filial piety) that offspring should provide care for their parents. However, the sustainability of this is threatened by the impact of the One-Child Policy (OCP) (1979-2015), which has resulted in a diminution in numbers of children available to care, rapid urbanisation and increase in the number of women in employment. In this context, the objective was to explore the motivations, meaning, and preparedness for future caregiving of offspring affected by the OCP. We adopted a constructivist position using a hermeneutic phenomenology approach and interviewed eight current and prospective caregivers aged 20-35 years about future caregiving responsibilities. Data were obtained through in-depth interviews, analysed using reflective Thematic Analysis. Three prominent themes: (i) Caregiving beliefs, (ii) Caregiving conditions and (iii) Contextual factors were identified under an overarching theme "Competing pressures-meanings, motivation and preparedness". Despite the inherent stress, participants envisaged providing or organising care in the future to fulfil Xiao, and most viewed long-term care settings as unviable. Ultimately, the findings suggested that the actual performance of caregiving would not always measure up to ideal expectations, resulting in 'filial discrepancy' that is, a gap between societal expectations for caregiving to older relatives and actual caregiving performance. This could adversely impact the caregivers and quality of care provided. The findings highlighted the urgent need to develop culturally attuned services, including education and training for family caregivers, health and social care professionals. / This work was supported by Research England: Quality Related Global Challenge Research Fund; University of Bradford.

Les problèmes d’ordonnancement de rendez-vous en tête-à-tête sont des problèmes dans lesquels des personnes souhaitent se rencontrer par deux lors de courts rendez-vous qui se déroulent lors d’une session unique. Dans cette thèse, nous référençons plusieurs applications de ce type de problèmes et proposons des notations qui généralisent les notations standards de problèmes d’ordonnancement α|β|γ. Nous nous intéressons en particulier à un cas dans lequel deux populations distinctes se rencontrent, des participants peuvent arriver en retard et des rencontres sont interdites. L’objectif est de minimiser le nombre maximal d’attentes des participants. Nous étudions dans un premier temps la complexité de ces problèmes : nous démontrons que plusieurs cas sans rencontre interdite sont polynomiaux et que le cas général est NP-complet au sens fort. Nous proposons ensuite des bornes inférieures. Puis nous développons plusieurs méthodes de résolution. Des modèles de programmation linéaire en nombres entiers et un modèle de programmation par contraintes sont tout d’abord proposés. Des règles de dominance permettant de limiter les symétries sont intégrées à ces modèles dans le but de limiter l’espace des solutions. Enfin, nous proposons une recherche à divergence limitée (limited discrepancy search) qui est une méthode approchée basée sur l’exploration d’un arbre de recherche tronqué. Dans cette méthode, nous exploitons le plus possible les propriétés de symétrie du problème pour faciliter la convergence vers une bonne solution. Toutes ces méthodes sont testées et comparées sur un ensemble de 300 instances générées aléatoirement d’après des paramètres réalistes. / One-to-one meeting scheduling problems are problems where a population of actors want to meet each other during short time slots that take place in a single session. In this thesis, we reference several applications of this type of problems found in the literature and introduce a notation extending the well-known scheduling notation α|β|γ. We are particularly interested in a case in which two distinct populations meet, participants may arrive late and some meetings are forbidden. The objective is to minimize the maximum number of participants waiting slots. First, we study the complexity of these problems: we show that several cases with no forbidden meeting are polynomial and that the general case is NP-complete in the strong sense. We then propose lower bounds. After that, we develop several resolution methods. Integer linear programming models and a constraint programming model are developed. To limit the solution space, we add dominance rules based on symmetries to these methods. Finally, we present a limited discrepancy search (i.e. an approximate method based on the exploration of a truncated tree search). In this method, we use as much as possible the symmetry properties of the problem to facilitate the convergence to a good solution. All these methods are tested and compared on a set of 300 randomly generated instances from realistic parameters.

Every year, about 1 million patients worldwide and 16000 patients in Sweden undergo total hip arthroplasty (THA). This surgical intervention is considered a successful, safe and cost-effective procedure to regain pain-free mobility and restore hip joint function in patients suffering from severe hip joint disease or trauma. Besides relieving the pain, restoration of biomechanical forces around the hip with appropriate femoral offset (FO), leg length and proper component position and orientation are important goals. The radiographic preoperative planning and postoperative evaluation of these parameters require good validity, interobserver reliability and intraobserver reproducibility. It remains controversial as to how much postoperative leg length discrepancy (LLD) and FO change are acceptable. Generally, lengthening of the operated leg ≥ 10mm and FO reduction of the operated hip > 5mm should be avoided by using preoperative radiological templating and intraoperative measurement methods. There is no consensus on the association between LLD and FO and outcome after THA. The aims of this thesis were to: 1. To determine the influence of non-corrected LLD after THA on patients’ reported hip function and quality of life (QoL). 2. To study the association of global FO changes after THA with patients’ reported hip function, QoL and abductor muscle strength. 3. To evaluate the concurrent validity of the Sundsvall method of measuring postoperative global FO by comparing it to a standard method and to evaluate the interobserver reliability and intraobserver reproducibility of measurement of postoperative global FO, LLD and acetabular cup inclination and anteversion. 4. To analyse the postoperative radiographs of THA patients with leg lengthening and FO reduction to determine whether the problem is located in the stem, cup or both. Study I: A prospective cohort study of 174 patients with unilateral osteoarthritis (OA), comparing patients with lengthening ≥ 10mm, restoration (between 9 mm lengthening and 5 mm shortening) or shortening > 5 mm of the operated leg after THA. Follow up was 12–15 months. We found that a LLD of up to 20 mm did not influence the functional outcome (WOMAC) or QoL (EQ-5D). However, the lengthening group showed less improvement in WOMAC and more use of a shoe lift. Study II: A prospective cohort study of 222 patients with unilateral hip OA, comparing patients with decreased global FO (> 5 mm reduction), restored FO (within 5 mm restoration), and increased FO (> 5 mm increment) after THA. Follow up was was 12–15 months. The unadjusted results showed that the decreased FO group had a worse WOMAC index, less abductor muscle strength, and more use of walking aids. When these results were adjusted for possible confounding factors, only global FO reduction was statistically significantly associated with reduced abductor muscle strength. The incidence of residual hip pain and analgesics use was similar in the 3 groups. Study III: A prospective cohort study of 90 patients with primary unilateral OA treated with THA. Global FO using the Sundsvall method, global FO (standard method), LLD, acetabular cup inclination and anteversion were measured on postoperative radiographs. The interobserver reliability and intraobserver reproducibility were tested using three independent observers. We found that the Sundsvall method is as reliable as the standard method and the evaluated radiographic measurement methods have the required validity and reliability to be used in clinical practice. Study IV: A prospective cohort study of 174 patients with unilateral primary OA treated with THA. LLD and global FO were measured on postoperative radiographs. Patients with lengthening of the operated leg ≥ 10mm (n=41) and patients with reduction of global FO > 5mm (n=58) were further studied to investigate the amount of lengthening and global FO reduction that took place in the stem and in the cup compared with the contralateral side. The interobserver reliability and intraobserver reproducibility were tested using two independent observers. We found that post-THA lengthening of the operated leg ≥ 10mm was mainly caused by improper placement of the femoral stem, whereas a decrease of global FO > 5 was caused by improper placement of both acetabular and femoral components. The radiological measurement methods used showed substantial to excellent interobserver reliability and intraobserver reproducibility and are therefore clinically useful. The main conclusions of this thesis are: LLD up to 20 mm and reduced global FO more than 5 mm did not influence the functional outcome or quality of life at 12–15 months postoperatively. Lengthening ≥ 10mm was associated with increased use of a shoe lift. A reduction of global FO more than 5 mm compared to the contralateral hip was associated with weaker hip abductor muscles and more use of walking aids. Therefore both should be avoided. The radiographic measurement methods of LLD, global FO, cup inclination and anteversion have the required validity and reliability to be used in clinical practice. Lengthening of the operated leg is mainly caused by improper femoral stem positioning while global FO reduction results from improper positioning of both acetabular and femoral components. Surgeons should be aware of these operative pitfalls in order to minimize component malpositioning. / Varje år opereras ungefär 1 miljon patienter runt om i världen och 16000 patienter i Sverige med en total höftledsprotes (THA). Operation med höftledsprotes anses vara enav de mest framgångsrika, säkra och kostnadseffektiva kirurgiska åtgärderna med syfte att för att återställa livskvalité. Målet är att smärtlindra och återställa rörligheten i dendestruerade höftleden vid artros, reumatisk destruktion eller men efter exempelvis Perthes sjukdom. Vid operation med THA är det viktigt att återställa de biomekaniskakrafterna runt höftleden med en adekvat så kallad femoral offset (FO), postoperativ benlängdsskillnad (BLS) och ett tillfredsställande komponentläge. Den preoperativaplaneringen och den postoperativa bedömning av dessa parametrar kräver god tillförlitlighet, det vill säga validitet och reproducerbarhet både mellan olika bedömareoch vid upprepade mätningar av samma bedömare. Det är fortfarande inte klarlagt hur mycket postoperativ förändring i FO och BLS som är acceptabla. I dagsläget är detacceptabelt om den postoperativa benförlängningen understiger 1 cm och förändringen i FO är under 5 mm. Det finns ingen konsensus huruvida det föreligger ett sambandmellan BLS, FO och den patientrapporterade höftfunktionen och livskvalitén efter THA. Syftet med denna avhandling var: 1. Att studera effekten av icke-korrigerad BLS efter THA på den patientrapporterade höftfunktionen och livskvalitén. 2. Att studera effekten av förändringen i FO efter THA på den patientrapporterade höftfunktion, livskvalitén och muskelstyrka i abduktion. 3. Att utvärdera validitet och reliabilitet av en så kallad global FO genom att jämföra den med den gällande standard metoden samt studera tillförlitlighet av de radiologiskamätningar av postoperativa BLS, FO, cup inklination och anteversion efter THA. 4. Att radiologiskt undersöka i vilken av komponenterna (stam eller cup) somförändringen i FO och BLS verkar vara förlagd. Studie I: En prospektiv kohortstudie med 174 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de som fått en BLSförlängning över 10mm, återställning (mellan 9mm förlängning och 5mm förkortning) eller förkortning >5mm av det opererande benet efter THA. Uppföljning gjordes 12-15månader postoperativt. Vi fann att BLS upp till 20mm påverkade inte höftfunktion (WOMAC) och livskvalité (EQ-5D), men den förlängda gruppen visade en mindreförbättring i WOMAC och rapporterade en mer frekvent användning av skoinlägg. Studie II: En prospektiv kohortstudie med 222 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de patienter medförminskad FO (> 5mm minskning), återställd FO (inom 5mm) eller ökad FO (>5mm ökning). Uppföljning genomfördes efter 1 år med WOMAC, styrkemätning av höftensabduktorer och en frågeformulär. En minskad FO var associerade med en minskad styrka i höftens abduktorer. Det var ingen skillnad mellan grupperna gällandekvarstående höftsmärta och användning av analgetika. Studie III: En prospektiv kohortstudie med 90 patienter som behandlats med THA på grund av primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättesglobala FO (Sundsvalls metodologi), globala FO (standard metod), BLS, cup inklination och anteversion. Reliabilitet och reproducerbarhet bedömdes mellan treoberoende observatörer. Vi fann att global FO (enligt Sundsvalls metodologi) är lika tillförlitlig som den nuvarande standardmetoden och de utvärderade radiologiskamätmetoderna har hög validitet och reliabilitet och kan således användas i klinisk praxis. Studie IV: En prospektiv kohortstudie med 174 patienter som behandlats med en THA för en primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättes BLSoch globala FO. Patienter med förlängning ≥ 10mm (n=41) och patienter med minskning av globala FO >5mm (n=58) studerades for att mäta förlängning ochglobala FO minskning som sitter i stammen eller i cup jämfört med kontralaterala sidan. Reliabilitet och reproducerbarhet bedömdes av två oberoende observatörer. Vifann att en BLS över 10mm sitter framför allt i stamkomponenten i lårbenet medan en minskning i FO över 5 mm sitter i båda stam och cup. De radiologiska mätmetodernahar hög reliabilitet och reproducerbarhet och kan således användas i klinisk praxis. De viktigaste slutsatserna i denna avhandling är: 1. BLS med en förlängning upp till 20 mm och en minskning av globala FO mer än 5 mm påverkar inte patientrapporterad höftfunktion eller livskvalitet 1 år postoperativt. 2. BLS med en förlängning mer än 9 mm var associerad med mer användning av skoinlägg. En minskad FO med mer än 5 mm jämfört med den icke opererade höftenvar associerad med en sämre muskelstyrka i abduktion och ökat användning av gånghjälpmedel. 3. De radiologiska mätmetoderna av BLS, FO, acetabulära komponentens inklination och anteversion har hög validitet och reliabilitet, vilket kan användas i klinisk praxis. 4. En förlängning av det opererade benet orsakas främst av en positioneringen av stamkomponenten i lårbenet medan förlust av FO beror på otillfredsställande placeringav både stam och den acetabulära komponenten. Kirurger bör vara medveten om dessa operativa fallgropar för att optimera det kirurgiska resultatet.

Le formalisme « Problème de Satisfaction de Contraintes » (ou CSP pour Constraint Satisfaction Problem) peut être considéré comme un langage de représentation formelle qui couvre l'ensemble des problèmes dont la modélisation fait intervenir des contraintes. L'intérêt de ce formalisme réside dans l'exploitation de la généricité d'algorithmes de résolution puissants mais également dans la performance d'algorithmes dédiés à des problèmes particuliers.Dans ce travail de thèse, nous étudions la résolution de CSP par des méthodes de recherche arborescente basées sur la notion de « divergence » (une divergence est relative à la contradiction d’une décision proposée par une heuristique de référence). Dans ce cadre, nous proposons de nouveaux mécanismes d'amélioration des méthodes de recherche générales qui exploitent les échecs rencontrés pendant la résolution, en adoptant des heuristiques de pondération des variables et des valeurs. Nous proposons également d'autres techniques spécifiques aux méthodes à base de divergences qui conditionnent l’exploration de l’arbre de recherche développé, notamment la restriction des divergences, les différents modes de comptage ainsi que le positionnement des divergences. Ces propositions sont validées par des expérimentations numériques menées sur des problèmes de satisfaction de contraintes réels et aléatoires. Des comparaisons sont effectuées entre variantes de méthodes à divergences intégrant différentes combinaisons des améliorations et d’autres méthodes connues pour leur performance.Dans une seconde partie, nous étendons nos propositions à un contexte d'optimisation en considérant la résolution de problèmes d'ordonnancement avec contraintes de délais (time lags). Nous traitons l'adaptation d'une méthode de « recherche par montée de divergences » (Climbing Discrepancy Search) pour la résolution de ces problèmes. Nous validons les performances de certaines variantes de cette méthode intégrant les mécanismes proposés dans ce travail sur des problèmes-test de la littérature / The CSP (Constraint Satisfaction Problem) formalism can be considered as a simple example of a formal representation language covering all problems including constraints. The advantage of this formalism consists in the fact that it allows powerful general-purpose algorithms as much as useful specific algorithms.In this PhD thesis, we study several tree search methods for solving CSPs and focus on ones based on the discrepancy concept (a discrepancy is a deviation from the first choice of the heuristic). In this context, we propose improving mechanisms for general methods. These mechanisms take benefits from conflicts and guide the search by weighting the variables and the values. We propose also special mechanisms for methods based on discrepancies as the discrepancies restriction, the discrepancies counting, and the discrepancies positions. All propositions are validated by experiments done on real and random CSPs. We compare variants of methods based on discrepancies integrating several combinations of improvements and other methods known for their efficiency.In a second part, we extend our propositions to an optimisation context considering scheduling problems with time lags. In this purpose, we adapt a discrepancy-based method, Climbing Discrepancy Search, to solve these problems. Efficiency of some improved variants of this method is tested on known benchmarks

L’intérêt considérable est dédié à l’autorégulation chez les conducteurs âgés. Notre première étude compare l’autorégulation des conducteurs âgés à celle des jeunes. Nous supposons trouver des corrélations positives entre les évitements auto-déclarés des situations de conduite difficiles et le niveau auto-déclaré de déclins cognitifs chez les conducteurs âgés, non pas chez les jeunes. Or, le fait d’opérationnaliser l’autorégulation par ce biais ne permet ni d’examiner le niveau d’autorégulation comportemental, ni les facteurs susceptibles de conditionner un tel comportement. Deux études sont alors conçues de sorte à définir le modèle de l’apprentissage autorégulé le plus adapté pour l’examen des capacités d’autorégulation (étude 2), et à identifier les éléments susceptibles de modifier une autorégulation comportementale (étude 3). Dans l’étude 2, nous testons dans une expérience sur simulateur de conduite deux modèles métacognitifs, dont celui s’avérant plus compréhensif est maintenu comme paradigme expérimental pour la troisième étude. Cette dernière compare les patterns d’autorégulation de deux groupes de conducteurs âgés, dont un soumis à la menace du stéréotype. Les résultats indiquent que les conducteurs âgés basent leurs comportements d’autorégulation sur leurs propres expériences de la difficulté, et que le fait de vouloir les instruire à l’aide d’indices extrinsèques semblables à ceux du stéréotype, puisse mener plus à une réduction de leur capacités qu’à leur supposée amélioration. / An increasing interest is actually devoted to the self-regulation in elderly drivers. Our first study compares the elderly drivers’ self-regulation to that of younger drivers. We suppose to observe in elderly drivers (but not in the younger ones) positive correlations between the self-declared avoidance of difficult driving situations and the self-declared decline of cognitive functioning. However, such an operationalization of self-regulation does not allow the study of neither the real behavioral self-regulation nor the factors conditioning such a behavior. Another two studies are then conceived in order to define both the self-regulated learning model that fits the best to the study of drivers’ self-regulatory patterns (study 2) and the factors that trigger such a behavioral self-regulation (study 3). In the second, driving-simulator study, we oppose the predictions of two metacognitive models, and this model that is better suited is withheld as the experimental paradigm for the third study. This latter compare the self-regulatory patterns of two groups of elderly drivers: one that is under stereotype threat and one that is not. Our results indicate that, first, elderly drivers presumably base their self-regulatory behavior on their sheer experience of the difficulty and, second, the efforts to enhance their self-regulation by extrinsic cues (such as those similar to the stereotype used in our third study) in fact hinder their self-regulatory abilities rather than enhance them.

The objective of this thesis is the implementation of Monte Carlo and quasi-Monte Carlo methods for the valuation of financial derivatives. Advantages and disadvantages of each method are stated based on both the literature and on independent computational experiments by the author. Various methods to generate pseudo-random and quasi-random sequences are implemented in a computationally uniform way to enable objective comparisons. Code is developed in VBA and C++, with the C++ code converted to a COM object to make it callable from Microsoft Excel and Matlab. From the simulated random sequences Brownian motion paths are built using various constructions and variance-reduction techniques including Brownian Bridge and Latin hypercube. The power and efficiency of the methods is compared on four financial securities pricing problems: European options, Asian options, barrier options and mortgage-backed securities. In this paper a detailed step-by-step algorithm is given for each method (construction of pseudo- and quasi-random sequences, Brownian motion paths for some stochastic processes, variance- and dimension- reduction techniques, evaluation of some financial securities using different variance-reduction techniques etc).

Many studies have investigated problems with the ability achievement discrepancy (AAD) method of diagnosing specific learning disabilities (SLDs). The definition of an SLD includes the presence of a deficit in one or more cognitive processing systems. Researchers in other studies found that the AAD method overdiagnoses English language learners and students from low socioeconomic backgrounds, and underdiagnoses students with cognitive processing deficits. Although SLD diagnostic methods have been widely researched, much less information is available regarding SLD diagnostic methods that predict important student outcomes, such as high school completion. The General Abilities Index (GAI) is an SLD diagnostic method that can identify cognitive processing deficits. This study examined the relationships between cognitive processing deficits and the GAI method, high school completion status, performance on state standards assessments, and SLD eligibility. Using a multivariate, nonexperimental design, this study analyzed 149 datasets from records of students tested for an SLD between 1996 to 2013. A GLM analysis found that several types of cognitive processing deficits predicted math and writing performance on the state standards assessment and predicted not being diagnosed with an SLD, while the GAI method failed to predict any relationship with the dependent variables. Positive social changes from this study may include improved SLD diagnostic practices and improved educational interventions that target the cognitive processing deficits. Improved educational outcomes for SLD persons may reduce the high rates of unemployment, substance abuse, and incarceration experienced by the adult SLD population.

Due to its generality and flexibility, the state-space model has become one of the most popular models in modern time domain analysis for the description and prediction of time series data. The model is often used to characterize processes that can be conceptualized as "signal plus noise," where the realized series is viewed as the manifestation of a latent signal that has been corrupted by observation noise. In the state-space framework, parameter estimation is generally accomplished by maximizing the innovations Gaussian log-likelihood. The maximum likelihood estimator (MLE) is efficient when the normality assumption is satisfied. However, in the presence of contamination, the MLE suffers from a lack of robustness. Basu, Harris, Hjort, and Jones (1998) introduced a discrepancy measure (BHHJ) with a non-negative tuning parameter that regulates the trade-off between robustness and efficiency. In this manuscript, we propose a new parameter estimation procedure based on the BHHJ discrepancy for fitting state-space models. As the tuning parameter is increased, the estimation procedure becomes more robust but less efficient. We investigate the performance of the procedure in an illustrative simulation study. In addition, we propose a numerical method to approximate the asymptotic variance of the estimator, and we provide an approach for choosing an appropriate tuning parameter in practice. We justify these procedures theoretically and investigate their efficacy in simulation studies. Based on the proposed parameter estimation procedure, we then develop a new model selection criterion in the state-space framework. The traditional Akaike information criterion (AIC), where the goodness-of-fit is assessed by the empirical log-likelihood, is not robust to outliers. Our new criterion is comprised of a goodness-of-fit term based on the empirical BHHJ discrepancy, and a penalty term based on both the tuning parameter and the dimension of the candidate model. We present a comprehensive simulation study to investigate the performance of the new criterion. In instances where the time series data is contaminated, our proposed model selection criterion is shown to perform favorably relative to AIC. Lastly, using the BHHJ discrepancy based on the chosen tuning parameter, we propose two versions of an influence diagnostic in the state-space framework. Specifically, our diagnostics help to identify cases that influence the recovery of the latent signal, thereby providing initial guidance and insight for further exploration. We illustrate the behavior of these measures in a simulation study.

Greater trochanteric pain (GTP) is a regional pain syndrome characterized by lateral hip pain and tenderness. Its incidence after total hip arthroplasty (THA) is variable. Bursal inflammation, degenerative changes of the attachment of the gluteal muscles, direct operative trauma and biomechanical disturbance of the operated hip have been discussed as being related to GTP. The diagnosis is purely clinical because radiological and laboratory investigations show no definite pathology. Although most treatment modalities are conservative, some patients may develop refractory complaints leading to surgical intervention. In study I we studied the incidence of GTP in 172 consecutive patients who underwent THA during 2002 at Sundsvall Hospital. Patients with GTP (n=21, incidence 12%) were matched with controls from the same cohort. The THA outcome was assessed using the Western Ontario and McMaster Universities Arthrosis (WOMAC) Index. Trochanteric tenderness was studied using an electronic pressure algometer. We found an association between the occurrence of GTP and postoperative uncorrected lengthening of the operated limb of ≥ one centimetre. The WOMAC index revealed a reduction of the clinical outcome in the GTP group. In Study II we tested the value of using an algometer in the diagnosis of GTP after THA. We measured the pressure-pain threshold (PPT) over the greater trochanter and ilio-tibial band in 18 patients and 18 matched controls. Both groups were evaluated using the visual analogue scale (VAS). We found the algometer to have a good predictive validity and reproducibility. However, there was large inter-individual variability across subjects. The PPT ratio of 0.8 (affected vs. unaffected side) can be used as a cutoff ratio to establish GTP. There was no correlation between PPT measurements and VAS. Because of a low positive predictive value and large inter-individual variability, the pressure algometer has a limited value as a screening tool. In study III we proposed a new surgical treatment for refractory GTP after THA consisting of distal lengthening of the ilio-tibial band (ITB) by Z-plasty under local anaesthesia. This method was used in 12 women between March 2004 and June 2006. The patients were followed up by phone interview 3-4 months postoperatively and by an EQ-5D questionnaire and clinical examination including evaluation with the algometer at 1-3 years postoperatively. We found that the patients‘ quality of life was markedly improved following the operation (EQ-5D = 0.26 preoperatively vs. 0.67 postoperatively; p <0.005). There were no postoperative complications. In study IV we evaluated the accuracy of a commonly used clinical method of LLD measurement (anterior superior iliac spine-medial malleolus) by comparing it to a reliable radiological method (tear drop-lesser trochanter) in 139 patients before and after THA. We found the correlation between the clinical and radiological methods to be weak preoperatively (r=0.21, ICC= 0.33) while the correlation was moderate postoperatively (r= 0.45, ICC=0.62). It is therefore recommended that the radiological method be used to measure leg length discrepancy in patients who undergo THA.