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Catatonia is a frequent, complex and severe identifiable syndrome of motor dysregulation. However, its pathophysiology is poorly understood.
We aimed to provide a systematic review of all brain imaging studies (both structural and functional) in catatonia.
We identified 137 case reports and 18 group studies representing 186 individual patients with catatonia. Catatonia is often associated with brain imaging abnormalities (in more than 75% of cases). The majority of the case reports show diffuse lesions of white matter, in a wide range of brain regions. Most of the case reports of functional imaging usually show frontal, temporal, or basal ganglia hypoperfusion. These abnormalities appear to be alleviated after successful treatment of clinical symptoms. Structural brain magnetic resonance imaging studies are very scarce in the catatonia literature, mostly showing diffuse cerebral atrophy. Group studies assessing functional brain imaging after catatonic episodes show that emotional dysregulation is related to the GABAergic system, with hypoactivation of orbitofrontal cortex, hyperactivation of median prefrontal cortex, and dysconnectivity between frontal and motor areas.
In catatonia, brain imaging is abnormal in the majority of cases, and abnormalities more frequently diffuse than localised. Brain imaging studies published so far suffer from serious limitations and for now the different models presented in the literature do not explain most of the cases. There is an important need for further studies including a better clinical characterisation of patients with catatonia, functional imaging with concurrent catatonic symptoms and the use of novel brain imaging techniques.
Nous relatons l’histoire clinique de monsieur J., âgé de 40 ans et pris en charge à la Clinique Psychiatrique Universitaire du CHRU de Tours depuis 1998. Il souffre d’une schizophrénie paranoïde. Il est traité par palipéridone LP 150 mg. Il bénéficie d’un suivi complémentaire en addictologie du fait d’une comorbidité addictive de type polytoxicomanie sevrée avec un traitement substitutif (chlorhydrate de méthadone 100 mg/j) et d’un TDAH traité par méthylphénidate chlorhydrate LP 80 mg/j. En novembre 2013, nous notons l’apparition soudaine d’une nouvelle thématique délirante, « j’ai un micro-émetteur sous la peau », coïncidant avec une majoration de la consommation de cannabis. Nous évoquons une recrudescence délirante chez un patient qui présente depuis des années un délire polymorphe à thématique principale mystique. « On remonte jusqu’à Jésus dans ma généalogie, etc ». À l’examen clinique, nous découvrons une masse distincte à l’endroit désigné par le patient comme lieu du micro-émetteur implanté. L’exploration anamnestique ne retrouve aucun élément en faveur d’un corps étranger sous-cutané. L’échographie pelvienne confirme la présence d’une masse sans orientation étiologique possible. Une tomodensitométrie pelvienne est alors recommandée, et permet d’authentifier la présence d’un corps étranger sous-cutané. Après notre insistance auprès de la famille, la mère retrouve dans le dossier médical de son fils un accord de consentement pour une prise en charge en addictologie alors qu’il était mineur (16 ans), avec pose d’un implant sous-cutané de disulfirame (retiré du marché français en 1997). Ceci a permis de mettre fin à l’errance diagnostique entre production délirante et réalité d’un implant sous-cutané de disulfirame oublié et vieux de 24 ans. Cette vignette clinique illustre la complexité de la clinique psychiatrique et souligne l’importance d’une écoute attentive et singulière de chaque patient.
Le recueil d’information jusqu’à la mise en place d’une contraception suivie par les patientes en santé mentale est un problème complexe. La mise en place d’une EPP sur la contraception et le diagnostic d’une grossesse au moment de l’admission nous a paru pertinente afin d’améliorer la prise en charge de ces patientes et prendre en compte les recommandations en vigueur. L’objectif principal était d’améliorer le repérage d’une grossesse au moment de l’admission. Les objectifs secondaires étaient :
– améliorer la mise en place d’une contraception ;
– prendre en compte les modalités de contraception en tenant compte des recommandations de la HAS ;
– sensibiliser les soignants aux risques tératogènes de certains médicaments.
Matériel et méthode
Pour mener notre EPP nous avons réalisé un audit clinique sur 80 dossiers de patientes âgées de 15 à 50 ans hospitalisées depuis au moins sept jours.
Résultats/Discussion : Dans :
– 65 % des dossiers, il y a un résultat de ΔHCG ;
– 37 % des dossiers, il y a une information sur les antécédents gynécologiques ;
– 27 % des dossiers, il y a une information sur la contraception.
Cette EPP a souligné la nécessité d’un meilleur recueil d’information autour de la contraception et du diagnostic d’une grossesse éventuelle. Elle a permis l’élaboration d’un plan d’action visant à sensibiliser les équipes soignantes, à systématiser le recueil d’information sur la contraception en cours, à prendre en compte les recommandations de la HAS sur la contraception, à mieux connaître les risques tératogènes de certains médicaments.
La prescription d’une contraception doit comprendre l’ensemble de ces aspects d’autant plus que les données récentes soulignent les risques tératogènes de certains médicaments : acide valproïque, paroxétine, lithium, carbamazépine, etc. Des fiches de bon usage vont être élaborées par la PUI et diffusées aux soignants.
According to a recent large-scale Swedish epidemiological study, 5 % of violent crimes are attributable to patients suffering from psychosis., We present the preliminary results of a feasibility study comparing violent and non-violent schizophrenics on underlying potential process such as impulsivity, emotionality using both, psychometrics and neuropsychological correlates.
Male Violents subjects where selected by clinicians on their life time histories of violence and control where paired according to age. Assessment include selected neuropsychological and psychometrics tests: BPRS (Brief Psychiatric Rating Scale), PCL-R (Psychopathy Checklist-Revised), BREF (Frontal Assessment Battery), WCST (Wisconsin Card Sorting Test), Iowa Gambling Task, BIS-11 (Impulsivity Scale).
Violent's performed better in the executive functions (WCST and the BREF), showing a better use of the dorso-side prefrontal cerebral cortex.
Their less good performances in the orbitofrontal functions, (Iowa Gambling Task, BREF), show cortical abnormalities involved in the processes of decision. Lesser capacity to recognize the appropriate feelings seems more present in deliberate violence, determined by the emotional coolness and the absence of fault, than in impulsive violence.
The PCL-R identifies the defect of orbitofrontal activation as the origin of the perturbed emotional integration and the bigger impulsiveness, by the slightest capacity of inhibition of the impulsive decisions.
Our results, especially when compared to literature data, show the existence of dysfunctional cerebral process in schizophrenic violent patients similar to those observed in psychopathy. They outline the need for further clinical and neuropsychological studies to identify pathophysiological processes and estimate the potential recurrence of such behaviours.
This study aimed to investigate the psychological disorders following rape as well as the course of Post-Traumatic Stress Disorder (PTSD), and to determine clinical factors predictive of chronic PTSD. Seventy-three rape victims were observed in a systematic follow-up study over 1 year following rape using structured interview schedules. The frequency of PTSD was massive. The early disorders predicting PTSD 1 year after rape included somatoform and dissociative disorders, agoraphobia and specific phobias as well as depressive and gender identity disorders and alcohol abuse. Through stepwise logistic regressions, the following were found to be good models of prediction of chronic PTSD 1 year after rape: for the characteristics of the traumas, intrafamily rape, being physically assaulted outside rape, and added physical violence during rape; for the early psychological and behavioural attitudes, low self-esteem, permanent feelings of emptiness and running away; and for early mental disorders, agoraphobia and depressive disorders. Finally, among all these predictive factors, added physical violence during rape, low self-esteem, permanent feelings of emptiness and agoraphobia were shown to constitute a strong model of predictors. People presenting features such as the predictive factors of chronic PTSD found in the study should be asked about a history of rape and symptoms of PTSD.
Dysfunctions of the emotion processing circuitry are associated with Major Depressive Disorder (MDD) and can be modulated by antidepressants like selective serotonin reuptake inhibitors (SSRIs). Moreover, motivation, pleasure or interest are important neuropsychological states of emotional life, and are known to be impaired in MDD patients. Under SSRIs, some patients report decreases in motivation and/or in emotional responsiveness commonly described as emotional detachment (Corruble E et al, 2013) and having significant impact on drug compliance and quality of life.
The antidepressant agomelatine displays a unique neurochemical profile, different from SSRIs, being a MT1/MT2 receptors agonist and a 5HT2C receptors antagonist (De Bodinat C et al, 2010). Data from healthy volunteers and patients suggest that agomelatine is associated with less emotional detachment as compared to SSRIs notably with a more specific action in the facial expression recognition task (Harmer CJ et al, 2011), lower scores on scales for blunting (Corruble E et al, 2013), and absence of sexual dysfunction (Montejo AL et al, 2010).
Here, the effects of two antidepressants, agomelatine (25 and 50mg) and escitalopram (10–20mg) on emotional detachment, emotional processing, motivation and sexual function were assessed during a 9-week randomised, double-blind, placebo-controlled, parallel-designed study in healthy male and female volunteers aged between 18-45 years. A battery of neuropsychological and motivation tasks/questionnaires available in the literature were used. Investigating antidepressant effects on key psychological processes in healthy volunteers allows elucidation of the direct actions of antidepressants unconfounded by changes in mood symptoms. The study is on progress.
Significant investment in new capacities for experimental research at high temperatures and pressures have provided new levels of understanding about the physical properties of carbon in fluids and melts, including its viscosity, electrical conductivity, and density. This chapter reviews the physical properties of carbon-bearing melts and fluids at high temperatures and pressures and highlights remaining unknowns left to be explored. The chapter also reviews how the remote sensing of the inaccessible parts of the Earth via various geophysical techniques – seismic shear wave velocity, attenuation, and electromagnetic signals of mantle depths – can be reconciled with the potential presence of carbon-bearing melts or fluids. Supplemental online material is available for this chapter at www.cambridge.org/9781108477499#resources.
Evidence suggests that low birth weight and fetal exposure to extreme maternal undernutrition is associated with cardiovascular disease in adulthood. Hyperemesis gravidarum, a clinical entity characterized by severe nausea and excess vomiting leading to a suboptimal maternal nutritional status during early pregnancy, is associated with an increased risk of adverse pregnancy outcomes. Several studies also showed that different measures related to hyperemesis gravidarum, such as maternal daily vomiting or severe weight loss, are associated with increased risks of adverse fetal pregnancy outcomes. Not much is known about long-term offspring consequences of maternal hyperemesis gravidarum and related measures during pregnancy. We examined the associations of maternal daily vomiting during early pregnancy, as a measure related to hyperemesis gravidarum, with childhood cardiovascular risk factors.
In a population-based prospective cohort study from early pregnancy onwards among 4,769 mothers and their children in Rotterdam, the Netherlands, we measured childhood body mass index, total fat mass percentage, android/gynoid fat mass ratio, preperitoneal fat mass area, blood pressure, lipids, and insulin levels. We used multiple regression analyses to assess the associations of maternal vomiting during early pregnancy with childhood cardiovascular outcomes.
Compared with the children of mothers without daily vomiting during early pregnancy, the children of mothers with daily vomiting during early pregnancy had a higher childhood total body fat mass (difference 0.12 standard deviation score [SDS]; 95% confidence interval [CI] 0.03–0.20), android/gynoid fat mass ratio (difference 0.13 SDS; 95% CI 0.04–0.23), and preperitoneal fat mass area (difference 0.10 SDS; 95% CI 0–0.20). These associations were not explained by birth characteristics but partly explained by higher infant growth. Maternal daily vomiting during early pregnancy was not associated with childhood blood pressure, lipids, and insulin levels.
Maternal daily vomiting during early pregnancy is associated with higher childhood total body fat mass and abdominal fat mass levels, but not with other cardiovascular risk factors. Further studies are needed to replicate these findings, to explore the underlying mechanisms and to assess the long-term consequences.
This paper reviews the effects of extended lactation (EXT) as a strategy in dairy cattle on milk production and persistency, reproduction, milk quality, lifetime performance of the cow and finally the economic effects on herd and farm levels as well as the impact on emission of greenhouse gas at product level. Primiparous cows are able to produce equal or more milk per feeding day during EXT compared with a standard 305-d lactation, whereas results for multiparous cows are inconsistent. Cows managed for EXT can achieve a higher lifetime production while delivering milk with unchanged or improved quality properties. Delaying insemination enhances mounting behaviour and allows insemination after the cow’s energy balance has become positive. However, in most cases EXT has no effect or a non-significant positive effect on reproduction. The EXT strategy sets off a cascade of effects at herd and farm level. Thus, the EXT strategy leads to fewer calvings and thereby expected fewer diseases, fewer replacement heifers and fewer dry days per cow per year. The optimal lifetime scenario for milk production was modelled to be an EXT of 16 months for first parity cows followed by an EXT of 10 months for later lactations. Modelling studies of herd dynamics indicate a positive effect of EXT on lifetime efficiency (milk per dry matter intake), mainly originating from benefits of EXT on daily milk yield in primiparous cows and the reduced number of replacement heifers. Consequently, EXT also leads to reduced total meat production at herd level. For the farmer, EXT can give the same economic return as a traditional lactation period. At farm level, EXT can contribute to a reduction in the environmental impact of dairy production, mainly as a consequence of the reduced production of beef. A wider dissemination of the EXT concept will be supported by methods to predict which cows may be most suitable for EXT, and clarification of how milking frequency and feeding strategy through the lactation can be organised to support milk yield and an appropriate body condition at the next calving.
We experimentally investigate the extensional flow of a sheet – or curtain – of viscoelastic liquid falling freely from a slot at constant flow rate under gravity. Extruded liquids are aqueous solutions of flexible polyethylene oxide (PEO) and of semi-rigid partially hydrolysed polyacrylamide (HPAM) with low shear viscosities. Velocimetry measurements reveal that the mean velocity field
is the distance from the slot exit) does not reduce to a free fall. More precisely, we show that the liquid falls initially with sub-gravitational accelerations up to a distance from the slot which scales as
is gravity and
is the extensional relaxation time of the liquid) due to the stretching of polymer molecules. Beyond this elastic length, inertia dominates and the local acceleration reaches the asymptotic free-fall value
. The length of the sub-gravitational part of the curtain is shown to be much larger than the equivalent viscous length
for Newtonian liquids of density
and dynamic viscosity
which is usually small compared to the curtain length. By analogy with Newtonian curtains, we show that the velocity field
rescales on a master curve. Besides, the flow is shown to be only weakly affected by the history of polymer deformations in the die upstream of the curtain. Furthermore, investigations on the curtain stability reveal that polymer addition reduces the minimum flow rate required to maintain a continuous sheet of liquid.
Weaning is a critical transition phase in swine production in which piglets must cope with different stressors that may affect their health. During this period, the prophylactic use of antibiotics is still frequent to limit piglet morbidity, which raises both economic and public health concerns such as the appearance of antimicrobial-resistant microbes. With the interest of developing tools for assisting health and management decisions around weaning, it is key to provide robustness indexes that inform on the animals’ capacity to endure the challenges associated with weaning. This work aimed at developing a modelling approach for facilitating the quantification of piglet resilience to weaning. A total of 325 Large White pigs weaned at 28 days of age were monitored and further housed and fed conventionally during the post-weaning period without antibiotic administration. Body weight and diarrhoea scores were recorded before and after weaning, and blood was sampled at weaning and 1 week later for collecting haematological data. A dynamic model was constructed based on the Gompertz–Makeham law to describe live weight trajectories during the first 75 days after weaning, following the rationale that the animal response is partitioned in two time windows (a perturbation and a recovery window). Model calibration was performed for each animal. Our results show that the transition time between the two time windows, as well as the weight trajectories are characteristic for each individual. The model captured the weight dynamics of animals at different degrees of perturbation, with an average coefficient of determination of 0.99, and a concordance correlation coefficient of 0.99. The utility of the model is that it provides biologically meaningful parameters that inform on the amplitude and length of perturbation, and the rate of animal recovery. Our rationale is that the dynamics of weight inform on the capability of the animal to cope with the weaning disturbance. Indeed, there were significant correlations between model parameters and individual diarrhoea scores and haematological traits. Overall, the parameters of our model can be useful for constructing weaning robustness indexes by using exclusively the growth curves. We foresee that this modelling approach will provide a step forward in the quantitative characterisation of robustness.
OBJECTIVES/SPECIFIC AIMS: Little is known about potentially obesogenic endocrine-disruptors’ effects on excessive gestational weight gain (GWG) and postpartum weight retention (PPWR), which increase risk of adverse pregnancy and postnatal outcomes. We explored associations between prenatal organophosphate (OP) pesticide exposure and increased weight both during and after pregnancy. METHODS/STUDY POPULATION: Three dimethyl (DM) and three diethyl (DE) OP metabolites were measured in spot urine samples collected at <18, 18-25, and >25 gestational weeks among 688 participants in the Generation R Study. Metabolite levels were expressed as molar concentration/gram creatinine and log10-transformed. GWG and PPWR were calculated as the difference between weight at each prenatal/postnatal visit or maximum gestational weight and pre-pregnancy weight. In covariate-adjusted regression models we assessed associations of metabolite concentrations at each prenatal visit and, where appropriate, averaged across pregnancy with early-to-mid pregnancy, mid-to-late pregnancy, late pregnancy-to-maximum, and total GWG; insufficient and excessive GWG according to Institute of Medicine guidelines; and long-term PPWR at 6 and 10 years postpartum. Based on OP pesticides’ lipophilicity and association with hypomethylation, we investigated interactions with pre-pregnancy body mass index, periconceptional folic acid supplementation, and breastfeeding duration. RESULTS/ANTICIPATED RESULTS: A 10-fold increase in late pregnancy DE metabolite concentration was associated with 1.34 kg [95% confidence interval: 0.55, 2.12] higher late pregnancy-to-maximum GWG. A 10-fold increase in mean DE metabolite concentration across pregnancy was associated with 2.41 kg [0.62, 4.20] lower PPWR at 6 years. Stratified analysis suggested that the prenatal finding was driven by women with pre-pregnancy BMI ≥25 kg/m2, while the postnatal finding was driven by women with pre-pregnancy BMI <25 kg/m2 and with inadequate folic acid supplementation. We found no associations between OP pesticide metabolites and insufficient or excessive weight gain and no interaction with breastfeeding. DISCUSSION/SIGNIFICANCE OF IMPACT: In this longitudinal analysis, we observed a positive association of OP pesticide metabolites with GWG in late pregnancy among overweight/obese women, potentially reflecting inhibition of OP pesticide detoxification by oxidative stress. Postnatally, under/normal weight women with higher OP pesticide metabolites had lower PPWR, possibly due to better metabolic function and a more healthful diet. These results suggest that there may be a critical period during the late phase of pregnancy when OP pesticide exposure may increase GWG, and this association may be amplified in overweight/obese women. Areas for future research include examination of how the interaction between OP pesticides and polymorphisms of the paraoxonase (PON1) gene, which detoxifies OP pesticides, affect GWG/PPWR; exploration of the interplay among maternal pre-pregnancy BMI, oxidative stress, and PON1 levels; and characterization of the variability of OP pesticides exposure across pregnancy using more frequent repeated urine samples.
Certain factors, such as food quality, label content and grocery characteristics, may be considered when purchasing foods. Food availability in the home has been shown to influence dietary behaviours, also associated with delay discounting (DD). The present study sought to characterize the relationships between DD, food purchasing considerations and healthfulness of foods in the home.
A cross-sectional, online survey of adults (n 477) was conducted with the following measures: DD, consideration of food quality (nutrition, taste) and grocery characteristics (price, ease of preparation, shelf-life) while shopping, use of food labels and food availability in the home. DD was assessed by the area under the delay discounting curve (AUC) using a binary choice task. Greater AUC reflects lower DD. Structural equation modelling was used to allow AUC to simultaneously predict purchasing considerations and foods in the home.
Adult employees in south-east Alabama, USA.
DD was negatively associated with food label use and emphasis on food quality when shopping (P<0·001). In the final model, DD was associated with availability of healthful foods in the home and emphasis on food quality and grocery characteristics. About 33 % of the variance in shopping behaviours, 5 % in food label use, 7 % in availability of healthful foods and 4 % in availability of unhealthful foods was explained by DD.
Individuals with lower DD appear to be more thoughtful in making food purchasing decisions and have healthful foods available in the home more frequently than individuals with higher DD.
Adverse exposures during fetal life and the postnatal period influence physical, cognitive and emotional development, and predispose to an increased risk of various chronic diseases throughout the life course. Findings from large observational studies in various populations and experimental animal studies have identified different modifiable risk factors in early life. Adverse maternal lifestyle factors, including overweight, unhealthy diet, sedentary behavior, smoking, alcohol consumption and stress in the preconception period and during pregnancy, are the most common modifiable risk factors leading to a suboptimal in-utero environment for fetal development. In the postnatal period, breastfeeding, infant growth and infant dietary intake are important modifiable factors influencing long-term offspring health outcomes. Despite the large amount of findings from observational studies, translation to lifestyle interventions seems to be challenging. Currently, randomized controlled trials focused on the influence of lifestyle interventions in these critical periods on short-term and long-term maternal and offspring health outcomes are scarce, have major limitations and do not show strong effects on maternal and offspring outcomes. New and innovative approaches are needed to move from describing these causes of ill-health to start tackling them using intervention approaches. Future randomized controlled lifestyle intervention studies and innovative observational studies, using quasi-experimental designs, are needed focused on the effects of an integrated lifestyle advice from preconception onwards on pregnancy outcomes and long-term health outcomes in offspring on a population level.
International investment law and arbitration commands global interest. It is the arena in which investor-State dispute settlement unfolds, a taught subject at the undergraduate and postgraduate levels, a field of practice, an academic pursuit, and even a political compaign. Shaped by general international law, investment treaties, arbitral jurisprudence and academic writings, international investment law and arbitration is as dynamic as its constituent variables. The variety of viewpoints on virtually every legal issue sustains an intense, ongoing international dialogue. Yet, this variety also poses a serious challenge to the systematic study of international investment law and arbitration.
This book is the first to synthesise the moving parts of international investment law and arbitration into a comprehensive narrative with a hybrid casebook-textbook format. By pairing carefully curated extracts from voluminous Awards and other documents with original commentary and analysis, Lim, Ho and Paparinskis deftly enhance the informative value of a traditional casebook with the explanatory value of a traditional textbook. And in doing so, they have written a book that gives their readers the best of both worlds.
Relying on their significant combined teaching, publishing and practical experience, Lim, Ho and Paparinskis deconstruct the many legal complexities and controversies of international investment law and arbitration in nineteen meticulous and engaging chapters. International Investment Law and Arbitration: Commentary, Awards and Other Materials fills the niche in the market for a compact general treatise which strikes a fine balance between doctrinal rigour and practical relevance. It is a book that both students and specialists will find accessible and instructive.
This remarkable first edition is an indispensable resource and an important contribution to the mastery of a prominent discipline.
Acinema’ envisions cinema as a libidinal set-up, dispositif pulsionnel, a notion elaborated in clear opposition to the Lacanian model of desire which relies on the negativity of a lack that is constitutive of the subject and limits desire to the movement of the signifying chain. Lyotard attempts to overcome this negativity, which opens the space of representation, by substituting for it the positivity of a desire that no longer relies on a foundational lack, but is instead thought dynamically in terms of quantities of energy. He finds such a positivity in the Freudian model of the death drive, a notion of desire as force that is repressed in Lacan by the pre-eminence of desire as wish. However, Lyotard elaborates his reflection on cinema in a narrow dialogue with Lacan. This dialogue, far from simply consisting in a rejection, entails crucial implications for a thinking of an efficacy of cinema envisioned as a libidinal set-up, and, more generally, for a thinking of the relationship of medial configurations with reality. Indeed, Lyotard goes as far as stating that ‘[t]he film acts like the orthopaedic mirror analysed by Lacan in 1949 as constitutive of the imaginary subject or objet a; that we are dealing with the social body in no ways alters its function’ (Ac 39).
This claim creates an association between three poles. It posits an analogy between the workings of the psyche and the workings of the cinematographic medium, an analogy that in turn provides the framework from which it becomes possible to posit that the film has a concrete, transformative effect on society. We are faced with this incredible reversal: cinema, a technology designed to record reality, has, in a certain sense that we will try to understand, a formative power over reality itself. The purpose of this chapter is to attempt to understand the meaning, the importance and the limitations of this statement within the context of the libidinal economic aesthetics that Lyotard elaborates in the 1970s.
This review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant (P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses were observed on growth rate (−12.8 g/day, P<0.05) and body composition (+0.9 mm backfat thickness, P=0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat (P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors, via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory.