1,328 research outputs found
Terguride stimulates locomotor activity at 2 months but not 10 months after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment of common marmosets
The mixed dopamine (DA) agonist/antagonist terguride acts as a DA antagonist on normosensitive receptors but shows DA agonistic properties at supersensitive DA receptors. Such a compound could offer an alternative to the treatment of Parkinson's disease with indirect or direct DA agonists. The present study compares the actions of terguride, 4-12 mg/kg i.p., in naive common marmosets with its effects in animals rendered parkinsonian by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 2 months or 10 months previously, in order to test its antiparkinsonian efficacy. Terguride reduced locomotor activity in naive common marmosets, similar to its effects in rodents and in line with the DA antagonistic activity of the compound. In marmosets treated with MPTP 2 months previously and exhibiting pronounced behavioural motor deficits, terguride stimulated locomotor activity, showing DA agonistic properties under these conditions. In contrast, the locomotor activity of animals that had recovered from MPTP treatment 10 months previously was not altered by terguride. It is concluded that terguride has anti-akinetic efficacy in this primate model of Parkinson's disease. In addition, terguride offers a unique opportunity to differentiate, pharmacologically, the extent of dopaminergic recovery from MPTP treatment in this primate species
Gender Differences in Left Ventricular Structure and Function During Antihypertensive Treatment: the Losartan Intervention for Endpoint Reduction in Hypertension Study.
Negative emotional stimuli reduce contextual cueing but not response times in inefficient search
In visual search, previous work has shown that negative stimuli narrow the focus of attention and speed reaction times (RTs). This paper investigates these two effects by first asking whether negative emotional stimuli narrow the focus of attention to reduce the learning of a display context in a contextual cueing task and, second, whether exposure to negative stimuli also reduces RTs in inefficient search tasks. In Experiment 1, participants viewed either negative or neutral images (faces or scenes) prior to a contextual cueing task. In a typical contextual cueing experiment, RTs are reduced if displays are repeated across the experiment compared with novel displays that are not repeated. The results showed that a smaller contextual cueing effect was obtained after participants viewed negative stimuli than when they viewed neutral stimuli. However, in contrast to previous work, overall search RTs were not faster after viewing negative stimuli (Experiments 2 to 4). The findings are discussed in terms of the impact of emotional content on visual processing and the ability to use scene context to help facilitate search
Bullying: An ecological approach to intervention in schools
Bullying is a major concern in education worldwide, particularly in countries such as New Zealand that are reported to have high rates of bullying in schools. In this article it is proposed that, in order to effectively prevent or substantially reduce bullying in schools, a systemic approach needs to be adopted, with interventions organized at various levels. An ecological model for bullying prevention is presented that suggests strategies and interventions at the levels of teachers, schools, communities, and society. Examples of interventions that have been found in the literature to have evidence supporting their effectiveness have been outlined at each of these levels. Guidelines are presented for schools adopting such an ecological model for addressing bullying and for bringing about the changes needed to implement it successfully
Topological order and thermal equilibrium in polariton condensates
We report the observation of the Berezinskii-Kosterlitz-Thouless transition for a 2D gas of exciton-polaritons, and through the joint measurement of the first-order coherence both in space and time we bring compelling evidence of a thermodynamic equilibrium phase transition in an otherwise open driven/dissipative system. This is made possible thanks to long polariton lifetimes in high-quality samples with small disorder and in a reservoir-free region far away from the excitation spot, that allow topological ordering to prevail. The observed quasi-ordered phase, characteristic for an equilibrium 2D bosonic gas, with a decay of coherence in both spatial and temporal domains with the same algebraic exponent, is reproduced with numerical solutions of stochastic dynamics, proving that the mechanism of pairing of the topological defects (vortices) is responsible for the transition to the algebraic order. Finally, measurements in the weak-coupling regime confirm that polariton condensates are fundamentally different from photon lasers and constitute genuine quantum degenerate macroscopic states
School closures during the 2009 influenza pandemic: national and local experiences
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Suitability and managerial implications of a Master Surgical Scheduling approach
Abstract: Operating room (OR) planning and scheduling is a popular and challenging subject within the operational research applied to health services research (ORAHS). However, the impact in practice is very limited. The organization and culture of a hospital and the inherent characteristics of its processes impose specific implementation issues that affect the success of planning approaches. Current tactical OR planning approaches often fail to account for these issues.Master surgical scheduling (MSS) is a promising approach for hospitals to optimize resource utilization and patient flows. We discuss the pros and cons of MSS and compare MSS with centralized and decentralized planning approaches. Finally, we address various implementation issues of MSS and discuss its suitability for hospitals with different organizational foci and culture
Mechanisms of Hearing Loss after Blast Injury to the Ear
Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of
increasing interest. The ear is the most common organ affected by blast injury because it is the bodyメs most sensitive
pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a
reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after
blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or
otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion
product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold
shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes,
indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or
damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the
cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that
recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not
include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory
dysfunction
Sonographic Lobe Localization of Alveolar-Interstitial Syndrome in the Critically Ill
Introduction. Fast and accurate diagnosis of alveolar-interstitial syndrome is of major importance in the critically ill. We evaluated the utility of lung ultrasound (US) in detecting and localizing alveolar-interstitial syndrome in respective pulmonary lobes as compared to computed tomography scans (CT). Methods. One hundred and seven critically ill patients participated in the study. The presence of diffuse comet-tail artifacts was considered a sign of alveolar-interstitial syndrome. We designated lobar reflections along intercostal spaces and surface lines by means of sonoanatomy in an effort to accurately localize lung pathology. Each sonographic finding was thereafter grouped into the respective lobe. Results. From 107 patients, 77 were finally included in the analysis (42 males with mean age = 61 ± 17 years, APACHE II score = 17.6 ± 6.4, and lung injury score = 1.0 ± 0.7). US exhibited high sensitivity and specificity values (ranging from over 80% for the lower lung fields up to over 90% for the upper lung fields) and considerable consistency in the diagnosis and localization of alveolar-interstitial syndrome. Conclusions. US is a reliable, bedside method for accurate detection and localization of alveolar-interstitial syndrome in the critically ill
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