186 research outputs found

    Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory

    Get PDF
    This article is meant as a summary and introduction to the ideas of effective field theory as applied to gravitational systems. Contents: 1. Introduction 2. Effective Field Theories 3. Low-Energy Quantum Gravity 4. Explicit Quantum Calculations 5. ConclusionsComment: 56 pages, 2 figures, JHEP style, Invited review to appear in Living Reviews of Relativit

    How well do computer-generated faces tap face expertise?

    Get PDF
    The use of computer-generated (CG) stimuli in face processing research is proliferating due to the ease with which faces can be generated, standardised and manipulated. However there has been surprisingly little research into whether CG faces are processed in the same way as photographs of real faces. The present study assessed how well CG faces tap face identity expertise by investigating whether two indicators of face expertise are reduced for CG faces when compared to face photographs. These indicators were accuracy for identification of own-race faces and the other-race effect (ORE)-the well-established finding that own-race faces are recognised more accurately than other-race faces. In Experiment 1 Caucasian and Asian participants completed a recognition memory task for own- and other-race real and CG faces. Overall accuracy for own-race faces was dramatically reduced for CG compared to real faces and the ORE was significantly and substantially attenuated for CG faces. Experiment 2 investigated perceptual discrimination for own- and other-race real and CG faces with Caucasian and Asian participants. Here again, accuracy for own-race faces was significantly reduced for CG compared to real faces. However the ORE was not affected by format. Together these results signal that CG faces of the type tested here do not fully tap face expertise. Technological advancement may, in the future, produce CG faces that are equivalent to real photographs. Until then caution is advised when interpreting results obtained using CG faces

    The late stage of Parkinson's –results of a large multinational study on motor and non-motor complications

    Get PDF
    INTRODUCTION: There is little information on the late stages of parkinsonism. METHODS: We conducted a multicentre study in 692 patients with late stage parkinsonism in six European countries. Inclusion criteria were disease duration of ≥7 years and either Hoehn and Yahr stage ≥4 or Schwab and England score of 50 or less. RESULTS: Average disease duration was 15.4 (SD 7.7) years and mean total UPDRS score was 82.7 (SD 22.4). Dementia according to MDS-criteria was present in 37% of patients. Mean levodopa equivalence dose was 874.1 (SD 591.1) mg/d. Eighty two percent of patients reported falls, related to freezing (16%) or unrelated to freezing (21% of patients) or occurring both related and unrelated to freezing (45%), and were frequent in 26%. Moderate-severe difficulties were reported for turning in bed by 51%, speech by 43%, swallowing by 16% and tremor by 11%. Off-periods occurred in 68% and were present at least 50% of the day in 13%, with morning dystonia occurring in 35%. Dyskinesias were reported by 45% but were moderate or severe only in 7%. Moderate-severe fatigue, constipation, urinary symptoms and nocturia, concentration and memory problems were encountered by more than half of participants. Hallucinations (44%) or delusions (25%) were present in 63% and were moderate-severe in 15%. The association with overall disability was strongest for severity of falls/postural instability, bradykinesia, cognitive score and speech impairment. CONCLUSION: These data suggest that current treatment of late stage parkinsonism in the community remains insufficiently effective to alleviate disabling symptoms in many patients

    Caregiver Burden in Late-Stage Parkinsonism and Its Associations

    Get PDF
    Background: Patients in the late stages of parkinsonism are highly dependent on others in their self-care and activities of daily living. However, few studies have assessed the physical, psychological and social consequences of caring for a person with late-stage parkinsonism. Patients and methods: Five hundred and six patients and their caregivers from the Care of Late Stage Parkinsonism (CLaSP) study were included. Patients’ motor and non-motor symptoms were assessed using the UPDRS and Non-motor symptom scale (NMSS), Neuropsychiatric inventory (NPI-12), and caregivers’ health status using the EQ-5D-3 L. Caregiver burden was assessed by the Zarit Burden Interview (ZBI). Results: The majority of caregivers were the spouse or life partner (71.2%), and were living with the patient at home (67%). Approximately half of caregivers reported anxiety/depression and pain/discomfort (45% and 59% respectively). The factors most strongly associated with caregiver burden were patients’ neuropsychiatric features on the total NPI score (r = 0.38, p < 0.0001), total NMSS score (r = 0.28, p < 0.0001), caring for male patients and patients living at home. Being the spouse, the hours per day assisting and supervising the patient as well as caregivers’ EQ-5D mood and pain scores were also associated with higher ZBI scores (all p < 0.001). Conclusion: The care of patients with late stage parkinsonism is associated with significant caregiver burden, particularly when patients manifest many neuropsychiatric and non-motor features and when caring for a male patient at home

    Ret is essential to mediate GDNF’s neuroprotective and neuroregenerative effect in a Parkinson disease mouse model

    Get PDF
    Glial cell line-derived neurotrophic factor (GDNF) is a potent survival and regeneration-promoting factor for dopaminergic neurons in cell and animal models of Parkinson disease (PD). GDNF is currently tested in clinical trials on PD patients with so far inconclusive results. The receptor tyrosine kinase Ret is the canonical GDNF receptor, but several alternative GDNF receptors have been proposed, raising the question of which signaling receptor mediates here the beneficial GDNF effects. To address this question we overexpressed GDNF in the striatum of mice deficient for Ret in dopaminergic neurons and subsequently challenged these mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Strikingly, in this established PD mouse model, the absence of Ret completely abolished GDNF’s neuroprotective and regenerative effect on the midbrain dopaminergic system. This establishes Ret signaling as absolutely required for GDNF’s effects to prevent and compensate dopaminergic system degeneration and suggests Ret activation as the primary target of GDNF therapy in PD

    Characteristics of Patients with Late-Stage Parkinsonism who are Nursing Home Residents Compared with those Living at Home

    Get PDF
    OBJECTIVES: To determine clinical characteristics and treatment complications of patients with late-stage Parkinsonism living in nursing homes compared with those living at home. DESIGN: Cross-sectional analysis. SETTING AND PARTICIPANTS: This study is an analysis of 692 patients with late stage Parkinsonism recruited to an in-depth international study, Care of Late-Stage Parkinsonism (CLaSP). MEASURES: Sociodemographic characteristics were compared between patients who were living in a nursing home (n = 194) and those living at home (n = 498). Clinical assessments included the Unified Parkinson's Disease Rating Scale (UPDRS), the nonmotor symptom scale, the neuropsychiatric inventory, and a structured interview of patients and carers. Predictors of nursing home status were determined in a multivariate analysis. RESULTS: Nursing home placement was strongly associated with more severe cognitive impairment, worse UPDRS motor scores and disability, and with being unmarried and older. Although nursing home residents had significantly higher axial scores, falls were less common. Despite similar levodopa equivalence doses, they had less dyskinesia. Nonmotor symptom burden, particularly delusion, hallucination, and depression scores were higher in nursing home residents, and they were more frequently on psychotropic medication. They had lower rates of dopamine agonist use and lower rates of impulse control disorders. In multivariate analysis, being unmarried, presence of cognitive impairment, worse disease severity as assessed on the UPDRS parts II and III, severity of delusions, and lower rate of dyskinesia were associated with nursing home placement. CONCLUSIONS AND IMPLICATIONS: These clinical characteristics suggest that in patients with Parkinsonsim who are nursing home residents, presence of cognitive impairment and delusions particularly add to the higher overall symptom burden, and more often require specific treatments, including clozapine. Despite similar levodopa equivalent daily dose, motor severity is higher, and dyskinesias, indicative of a response to levodopa, are less common. Falls, however, also occur less commonly, and dopamine agonists are less frequently used, with lower rates of impulse control disorder

    Dysphagia in multiple system atrophy consensus statement on diagnosis, prognosis and treatment.

    Get PDF
    Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a combination of autonomic failure plus cerebellar syndrome and/or parkinsonism. Dysphagia is a frequent and disabling symptom in MSA and its occurrence within 5 years of motor onset is an additional diagnostic feature. Dysphagia can lead to aspiration pneumonia, a recognized cause of death in MSA. Guidelines for diagnosis and management of dysphagia in MSA are lacking. An International Consensus Conference among experts with methodological support was convened in Bologna to reach consensus statements for the diagnosis, prognosis, and treatment of dysphagia in MSA. Abnormalities of the oral and pharyngeal phases of swallowing, esophageal dysfunction and aspiration occur in MSA and worsen as the disease progresses. According to the consensus, dysphagia should be investigated through available screening questionnaires and clinical and instrumental assessment (videofluoroscopic study or fiberoptic endoscopic evaluation of swallowing and manometry) at the time of MSA diagnosis and periodically thereafter. There is evidence that dysphagia is associated with poor survival in MSA, however effective treatments for dysphagia are lacking. Compensatory strategies like diet modification, swallowing maneuvers and head postures should be applied and botulinum toxin injection may be effective in specific conditions. Percutaneous endoscopic gastrostomy may be performed when there is a severe risk of malnutrition and pulmonary complications, but its impact on survival is undetermined. Several research gaps and unmet needs for research involving diagnosis, prognosis, and treatment were identified
    corecore