Holographic Wilsonian flows and emergent fermions in extremal charged black holes

We study holographic Wilsonian RG in a general class of asymptotically AdS backgrounds with a U(1) gauge field. We consider free charged Dirac fermions in such a background, and integrate them up to an intermediate radial distance, yielding an equivalent low energy dual field theory. The new ingredient, compared to scalars, involves a `generalized' basis of coherent states which labels a particular half of the fermion components as coordinates or momenta, depending on the choice of quantization (standard or alternative). We apply this technology to explicitly compute RG flows of charged fermionic operators and their composites (double trace operators) in field theories dual to (a) pure AdS and (b) extremal charged black hole geometries. The flow diagrams and fixed points are determined explicitly. In the case of the extremal black hole, the RG flows connect two fixed points at the UV AdS boundary to two fixed points at the IR AdS_2 region. The double trace flow is shown, both numerically and analytically, to develop a pole singularity in the AdS_2 region at low frequency and near the Fermi momentum, which can be traced to the appearance of massless fermion modes on the low energy cut-off surface. The low energy field theory action we derive exactly agrees with the semi-holographic action proposed by Faulkner and Polchinski in arXiv:1001.5049 [hep-th]. In terms of field theory, the holographic version of Wilsonian RG leads to a quantum theory with random sources. In the extremal black hole background the random sources become `light' in the AdS_2 region near the Fermi surface and emerge as new dynamical degrees of freedom.Comment: 37 pages (including 8 pages of appendix), 10 figures and 2 table

Multitrace deformations, Gamow states, and Stability of AdS/CFT

We analyze the effect of multitrace deformations in conformal field theories at leading order in a large N approximation. These theories admit a description in terms of a weakly coupled gravity dual. We show how the deformations can be mapped into boundary terms of the gravity theory and how to reproduce the RG equations found in field theory. In the case of doubletrace deformations, and for bulk scalars with masses in the range $-d^2/4<m^2<-d^2/4+1$, the deformed theory flows between two fixed points of the renormalization group, manifesting a resonant behavior at the scale characterizing the transition between the two CFT's. On the gravity side the resonance is mapped into an IR non-normalizable mode (Gamow state) whose overlap with the UV region increases as the dual operator approaches the free field limit. We argue that this resonant behavior is a generic property of large N theories in the conformal window, and associate it to a remnant of the Nambu-Goldstone mode of dilatation invariance. We emphasize the role of nonminimal couplings to gravity and establish a stability theorem for scalar/gravity systems with AdS boundary conditions in the presence of arbitrary boundary potentials and nonminimal coupling.Comment: 14 pages, references added, introduction change

Semi-local quantum liquids

Gauge/gravity duality applied to strongly interacting systems at finite density predicts a universal intermediate energy phase to which we refer as a semi-local quantum liquid. Such a phase is characterized by a finite spatial correlation length, but an infinite correlation time and associated nontrivial scaling behavior in the time direction, as well as a nonzero entropy density. For a holographic system at a nonzero chemical potential, this unstable phase sets in at an energy scale of order of the chemical potential, and orders at lower energies into other phases; examples include superconductors and antiferromagnetic-type states. In this paper we give examples in which it also orders into Fermi liquids of "heavy" fermions. While the precise nature of the lower energy state depends on the specific dynamics of the individual system, we argue that the semi-local quantum liquid emerges universally at intermediate energies through deconfinement (or equivalently fractionalization). We also discuss the possible relevance of such a semi-local quantum liquid to heavy electron systems and the strange metal phase of high temperature cuprate superconductors.Comment: 31 pages, 7 figure

Effective AdS/renormalized CFT

For an effective AdS theory, we present a simple prescription to compute the renormalization of its dual boundary field theory. In particular, we define anomalous dimension holographically as the dependence of the wave-function renormalization factor on the radial cutoff in the Poincare patch of AdS. With this definition, the anomalous dimensions of both single- and double- trace operators are calculated. Three different dualities are considered with the field theory being CFT, CFT with a double-trace deformation and spontaneously broken CFT. For the second dual pair, we compute scaling corrections at the UV and IR fixed points of the RG flow triggered by the double-trace deformation. For the last case, we discuss whether our prescription is sensitive to the AdS interior or equivalently, the IR physics of the dual field theory.Comment: 20 pages, 3 figure

Ganho de peso, dislipidemia e parâmetros alterados para síndrome metabólica em pacientes de primeiro episódio psicótico após seguimento de seis meses

OBJECTIVES: Obesity and metabolic abnormalities are frequent in psychotic patients, including first-episode psychosis. We evaluated weight and metabolic parameters in first-episode psychotic outpatients from the First Episode Psychosis Program, Universidade Federal de São Paulo (UNIFESP). METHOD: Weight, height, waist and hip circumferences, glucose and lipid levels were measured at baseline and after a six-month period. RESULTS: Fifty-seven patients were included and 44 (77.2%) of them finished the study. Patients had a median age of 26.3 years, 60% were men and 43% had a diagnosis of schizophrenia at the endpoint. Weight and BMI values increased significantly during the follow-up (p < 0.01). The average weight gain at the follow-up was 10.1% of the baseline weight (SD = 11.9). Only women presented significant waist abnormalities: at the first assessment the waist mean was 79.12 cm (SD = 10.68) and 6 months later it had increased to 89.65 cm (SD = 11.19, z = -3.182, p = 0.001). After 6 months, the total cholesterol (p = 0.004), and triglyceride levels (p = 0.016) increased, while HDL-cholesterol levels decreased (p = 0.025). During the follow-up period one patient (2.3%) developed diabetes mellitus, one (2.3%) presented altered fasting glucose, 12 (27.2%) patients developed at least two altered parameters for metabolic syndrome and 3 (6.8%) patients developed metabolic syndrome (p = 0.001). DISCUSSION: The results of this study showed that in a short period of time individuals under antipsychotic treatment had their weight increased significantly and developed important metabolic abnormalities. CONCLUSIONS: Clinicians should be aware of these risks, choose an antipsychotic that causes less weight gain and should monitor these patients carefully, and recommend prophylactic measures as diet restriction and physical activities.OBJETIVOS: Obesidade e alterações metabólicas são freqüentes em pacientes psicóticos, inclusive no primeiro episódio psicótico. Foram avaliados peso e parâmetros metabólicos em pacientes em tratamento no Programa de Episódio Psicótico da Universidade Federal de São Paulo (UNIFESP). MÉTODO: Peso, altura, medida de cintura e quadril, glicemia e perfil lipídico foram avaliados no início do tratamento e após seis meses. RESULTADOS: Cinqüenta e sete pacientes foram incluídos no estudo e 44 (72%) concluíram o estudo. Os pacientes apresentavam em média 26,3 anos, 60% eram do sexo masculino e, ao final do estudo, 43% apresentavam diagnóstico de esquizofrenia. Houve aumento significativo do peso e índice de massa corporal durante o estudo (p < 0,01). Em média, o peso aumentou 10,1% do peso inicial (SD = 11,9). Apenas mulheres apresentaram alterações na medida da cintura: no início, a média da cintura era de 79,12 cm (SD = 10,68) e, após seis meses, houve um aumento para 89,65 cm (SD = 11,19, z = -3,182, p = 0,001). Após seis meses, houve aumento do colesterol total (p = 0,004) e triglicérides (p = 0,016), e diminuição dos níveis de colesterol HDL (p = 0,025). No período, um paciente (2,3%) desenvolveu diabetes mellitus, um paciente (2,3%) apresentou glicemia de jejum alterada, 12 (27,2%) desenvolveram pelo menos dois parâmetros alterados para síndrome metabólica, e 3 (6,8%) apresentaram síndrome metabólica (p = 0,001). DISCUSSÃO: Os resultados deste estudo mostram que em um curto período de tempo pacientes em tratamento com antipsicóticos aumentaram substancialmente o peso e desenvolveram importantes alterações metabólicas. CONCLUSÃO: Os clínicos devem estar atentos a esses riscos, escolher medicações que causem menor ganho de peso, devendo monitorar esses pacientes cuidadosamente e recomendar medidas profiláticas como restrição dietética e atividade física.Universidade Federal de São Paulo (UNIFESP) Department of Psychiatry First-episode Psychosis ProgramUNIFESP, Department of Psychiatry First-episode Psychosis ProgramSciEL

Physiological and Psychological Effects of Deception on Pacing Strategy and Performance: A Review

The aim of an optimal pacing strategy during exercise is to enhance performance whilst ensuring physiological limits are not surpassed, which has been shown to result in a metabolic reserve at the end of the exercise. There has been debate surrounding the theoretical models that have been proposed to explain how pace is regulated, with more recent research investigating a central control of exercise regulation. Deception has recently emerged as a common, practical approach to manipulate key variables during exercise. There are a number of ways in which deception interventions have been designed, each intending to gain particular insights into pacing behaviour and performance. Deception methodologies can be conceptualised according to a number of dimensions such as deception timing (prior to or during exercise), presentation frequency (blind, discontinuous or continuous) and type of deception (performance, biofeedback or environmental feedback). However, research evidence on the effects of deception has been perplexing and the use of complex designs and varied methodologies makes it difficult to draw any definitive conclusions about how pacing strategy and performance are affected by deception. This review examines existing research in the area of deception and pacing strategies, and provides a critical appraisal of the different methodological approaches used to date. It is hoped that this analysis will inform the direction and methodology of future investigations in this area by addressing the mechanisms through which deception impacts upon performance and by elucidating the potential application of deception techniques in training and competitive settings

Treatment of neuromyelitis optica: state-of-the-art and emerging therapies.

Neuromyelitis optica (NMO) is an autoimmune disease of the CNS that is characterized by inflammatory demyelinating lesions in the spinal cord and optic nerve, potentially leading to paralysis and blindness. NMO can usually be distinguished from multiple sclerosis (MS) on the basis of seropositivity for IgG antibodies against the astrocytic water channel aquaporin-4 (AQP4). Differentiation from MS is crucial, because some MS treatments can exacerbate NMO. NMO pathogenesis involves AQP4-IgG antibody binding to astrocytic AQP4, which causes complement-dependent cytotoxicity and secondary inflammation with granulocyte and macrophage infiltration, blood-brain barrier disruption and oligodendrocyte injury. Current NMO treatments include general immunosuppressive agents, B-cell depletion, and plasma exchange. Therapeutic strategies targeting complement proteins, the IL-6 receptor, neutrophils, eosinophils and CD19--all initially developed for other indications--are under clinical evaluation for repurposing for NMO. Therapies in the preclinical phase include AQP4-blocking antibodies and AQP4-IgG enzymatic inactivation. Additional, albeit currently theoretical, treatment options include reduction of AQP4 expression, disruption of AQP4 orthogonal arrays, enhancement of complement inhibitor expression, restoration of the blood-brain barrier, and induction of immune tolerance. Despite the many therapeutic options in NMO, no controlled clinical trials in patients with this condition have been conducted to date

Non-pharmacological interventions for weight gain in patients with schizophrenia taking antipsychotics

INTRODUCTION: Schizophrenic patients have a higher prevalence of obesity than the general population. There are several factors implicated in weight gain, including poor dietary conditions, sedentary lifestyle and antipsychotic drugs use. Obesity is also associated with metabolic disturbances such as diabetes mellitus. Weight gain interventions are necessary in this population, especially non-pharmacological interventions. OBJECTIVE: To review the non-pharmacological interventions for weight gain management in patients with schizophrenia. METHODS: Eight clinical trials and four open-label studies using these interventions were found. The methodology, strength and limitations of the studies were reviewed. CONCLUSIONS: Non-pharmacological interventions seem to have an important effect on weight gain prevention and control, and should be encouraged and adapted to patients and in mental health institution's reality.INTRODUÇÃO: Pacientes com esquizofrenia têm maior prevalência de obesidade em comparação à população geral. Esse fato está relacionado a uma alimentação inadequada, ao sedentarismo e ao uso de antipsicóticos. O aumento da obesidade associa-se a diversos distúrbios metabólicos, como o diabetes melito. As intervenções para prevenção e controle do ganho de peso são necessárias nessa população, em especial as intervenções não farmacológicas. OBJETIVO: Revisar os estudos sobre intervenções não farmacológicas para prevenção e controle do ganho de peso em pacientes com esquizofrenia. MÉTODOS: Foram encontrados oito estudos controlados e quatro não controlados sobre intervenções não farmacológicas. Foi feita uma revisãosobre a metodologia e os fatores positivos e limitações dos estudos. CONCLUSÕES: As intervenções não farmacológicas parecem ter um efeito importante em termos de prevenção e controle do ganho de peso e, portanto, devem ser incentivadas e adaptadas à realidade dos pacientes e serviços de saúde., Universidade Federal de São Paulo (UNIFESP) Departamento de PsiquiatriaUNIFESP Disciplina de Endocrinologia Departamento de MedicinaUNIFESP, Depto. de PsiquiatriaUNIFESP, Disciplina de Endocrinologia Depto. de MedicinaSciEL

Pacing and Decision Making in Sport and Exercise: The Roles of Perception and Action in the Regulation of Exercise Intensity

In pursuit of optimal performance, athletes and physical exercisers alike have to make decisions about how and when to invest their energy. The process of pacing has been associated with the goal-directed regulation of exercise intensity across an exercise bout. The current review explores divergent views on understanding underlying mechanisms of decision making in pacing. Current pacing literature provides a wide range of aspects that might be involved in the determination of an athlete's pacing strategy, but lacks in explaining how perception and action are coupled in establishing behaviour. In contrast, decision-making literature rooted in the understanding that perception and action are coupled provides refreshing perspectives on explaining the mechanisms that underlie natural interactive behaviour. Contrary to the assumption of behaviour that is managed by a higher-order governor that passively constructs internal representations of the world, an ecological approach is considered. According to this approach, knowledge is rooted in the direct experience of meaningful environmental objects and events in individual environmental processes. To assist a neuropsychological explanation of decision making in exercise regulation, the relevance of the affordance competition hypothesis is explored. By considering pacing as a behavioural expression of continuous decision making, new insights on underlying mechanisms in pacing and optimal performance can be developed. © 2014 Springer International Publishing Switzerland

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe