369 research outputs found
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Illegal Drugs and Public Corruption: Crack Based Evidence from California
Do illegal drugs foster public corruption? To estimate the causal effect of drugs on public corruption in California, we adopt the synthetic control method and exploit the fact that crack cocaine markets emerged asynchronously across the United States. We focus on California because crack arrived here in 1981, before reaching any other state. Our results show that public corruption more than tripled in California in the first three years following the arrival of crack cocaine. We argue that this resulted from the particular characteristics of illegal drugs: a large trade-off between profits and law enforcement, due to a cheap technology and rigid demand. Such a trade-off fosters a convergence of interests between criminals and corrupted public officials resulting in a positive causal impact of illegal drugs on corruption
Movement-related potentials in Parkinson's disease
To date, many different approaches have been used to study the impairment of motor function in Parkinson's disease (PD). Event-related potentials (ERPs) are averaged amplitude fluctuations of the ongoing EEG activity that are time locked to specific sensory, motor or cognitive events, and as such can be used to study different brain processes with an excellent temporal resolution. Movement-related potentials (MRPs) are ERPs associated with processes of voluntary movement preparation and execution in different paradigms. In this review we concentrate on MRPs in PD. We review studies recording the Bereitschaftspotential, the Contingent Negative Variation, and the lateralized readiness potential in PD to highlight the contributions they have made to further understanding motor deficits in PD. Possible directions for future research are also discussed
Event-related potentials and cognition in Parkinson's disease: An integrative review
Cognitive impairment is a common non-motor symptom of Parkinson’s disease (PD), but the nature of cognitive changes varies considerably between individuals. According to the dual-syndrome hypothesis, one cluster of patients is characterized by deficits in executive function that may be related to fronto-striatal dysfunction. Other patients primarily show non-frontal cognitive impairments that progress rapidly to PD dementia (PDD). We provide a comprehensive review of event-related potential (ERP) studies to identify ERP measures substantiating the heterogeneity of cognitive impairment in PD. Our review revealed evidence for P3b and mismatch-negativity alterations in PDD, but not in non-demented PD, indicating that alterations of these ERPs constitute electrophysiological markers for PDD. In contrast, ERP correlates of executive functions, such as NoGo-P3, N2, and error(-related) negativity (Ne/ERN), appear to be attenuated in non-demented PD patients in a dopamine-dependent manner. Hence, ERP measures confirm and yield distinct electrophysiological markers for the heterogeneity of cognitive impairment in PD. We discuss limitations and open questions of the ERP approach and provide directions and predictions for future ERP research
Effects of Dopamine Medication on Sequence Learning with Stochastic Feedback in Parkinson's Disease
A growing body of evidence suggests that the midbrain dopamine system plays a key role in reinforcement learning and disruption of the midbrain dopamine system in Parkinson's disease (PD) may lead to deficits on tasks that require learning from feedback. We examined how changes in dopamine levels (“ON” and “OFF” their dopamine medication) affect sequence learning from stochastic positive and negative feedback using Bayesian reinforcement learning models. We found deficits in sequence learning in patients with PD when they were “ON” and “OFF” medication relative to healthy controls, but smaller differences between patients “OFF” and “ON”. The deficits were mainly due to decreased learning from positive feedback, although across all participant groups learning was more strongly associated with positive than negative feedback in our task. The learning in our task is likely mediated by the relatively depleted dorsal striatum and not the relatively intact ventral striatum. Therefore, the changes we see in our task may be due to a strong loss of phasic dopamine signals in the dorsal striatum in PD
Follow-up CMR in a case of Loeffler endocarditis
The typical finding of hypereosinophilic syndrome (Eosinophilic myocarditis) in the delayed enhancement (DE) cardiac magnetic resonance (CMR) is the �double V� sign, which includes (a) normal myocardium, (b) thickened enhanced endomyocardial layer, and (c) overlying apical thrombus. Corticosteroids may result in significant improvement of myocardial involvement. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt
Motor symptoms in Parkinson's disease: A unified framework
Parkinson’s disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (akinesia and bradykinesia, tremor and rigidity), PD patients show additional motor deficits, including: gait disturbance, impaired handwriting, grip force and speech deficits, among others. Some of these motor symptoms (e.g., deficits of gait, speech, and handwriting) have similar clinical profiles, neural substrates, and respond similarly to dopaminergic medication and deep brain stimulation (DBS). Here, we provide an extensive review of the clinical characteristics and neural substrates of each of these motor symptoms, to highlight precisely how PD and its medical and surgical treatments impact motor symptoms. In conclusion, we offer a unified framework for understanding the range of motor symptoms in PD. We argue that various motor symptoms in PD reflect dysfunction of neural structures responsible for action selection, motor sequencing, and coordination and execution of movement
Nitric oxide in the nucleus raphe magnus modulates cutaneous blood flow in rats during hypothermia
Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of hypothermia. Results: Intra�NRM injection of SNP (exogenous NO donor, 0.1� 0.2 μl, 0.2 nM) increased the blood flow. Similarly, unilateral microinjection of glutamate (0.1� 0.2 μl, 2.3 nM) into the nucleus increased the blood flow. This effect of L�glutamate was reduced by prior intra NRM administration of NO synthase inhibitor NG�methyl�L�arginine or NG�nitro�L�arginine methyl ester (L�NAME, 0.1 μl, 100 nM). Conclusion: It is concluded that NO modulates the thermoregulatory response of NRM to hypothermia and may interact with excitatory amino acids in central skin blood flow regulation. © 2015, Mashhad University of Medical Sciences. All rights reserved
The occurrence of giant mesenteric cyst and adrenal ganglioneuroma in a schizophrenic male patient presenting as pseudocyesis: A case report
In psychological patients like our case, somatically expressed symptoms which can imply another psychological syndrome should be dealt with cautiously. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt
An adult case with absence of left pulmonary artery and partial anomalous pulmonary venous connection: Case report and literature review
Unilateral absence of pulmonary artery is a rare congenital disorder that can remain asymptomatic until adulthood. Absence of left pulmonary artery (ALPA) has been reported in one-third of these patients. We are the first to introduce an adult case of ALPA associated with partial anomalous pulmonary venous connection. © 2021 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd
Two Challenging Cases with COVID heart
COVID-19 affects the heart through various pathways. It can increase thrombotic complications that ultimately lead to myocardial infarction even in patients without a history of underlying heart disease. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt
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