783 research outputs found
The Correlation between Sleep and Creativity
Fredrich August von Kekule, a famous German chemist, was attempting to determine the shape of the benzene molecule, which was known to have six carbon atoms. In 1865, reflecting upon his discovery of the hexagonal-ring like structure, he asserted that the solution came to him in a dream1; however, it is not clear if he was in rapid eye movement (REM) sleep dreaming or if he was in non-REM (NREM) sleep imagery. It is possible to think of this type of discoveries as an expression of creativity, i.e. the ability to use existing pieces of information and combine them in novel patterns leading to greater understanding and new solutions. Preliminary support of the role of sleep in creative thinking comes from a recent study by Wagner et al.2; these authors asked normal participants to perform a cognitive task, the Number Reduction Task. In this task, participants are required to understand a set of stimulus-response sequences and supply a single representative numerical answer. Improvement in task performance may be gradual (i.e., by slowly increasing response speed), or abrupt (after insight into an abstract rule underlying all sequences). They found that 59% of the participants that were allowed to sleep were able to perform the task in a time that was 70% shorter than the other group that did not sleep and suggested that sleep may facilitate insight-related problem solving. Here we report the results of the first study showing a direct complex correlation between sleep architecture or microstructure and creativity in normal controls
Aphasia and the Diagram Makers Revisited: an Update of Information Processing Models
Aphasic syndromes from diseases such as stroke and degenerative disorders are still common and disabling neurobehavioral disorders. Diagnosis, management and treatment of these communication disorders are often dependent upon understanding the neuropsychological mechanisms that underlie these disorders. Since the work of Broca it has been recognized that the human brain is organized in a modular fashion. Wernicke realized that the types of signs and symptoms displayed by aphasic patients reflect the degradation or disconnection of the modules that comprise this speech-language network. Thus, he was the first to propose a diagrammatic or information processing model of this modular language-speech network. Since he first published this model many new aphasic syndromes have been discovered and this has led to modifications of this model. This paper reviews some of the early (nineteenth century) models and then attempts to develop a more up-to-date and complete model
Phonologic Rehabilitation of Anomia in Aphasia
The single most common feature of aphasia is impairment in ability to name, whether it involves naming seen objects, or producing nouns, verbs and other words conveying meaning in spontaneous language. The traditional treatment approach to this problem is to explicitly train aphasic patients in naming. Controlled studies have shown that this approach may be quite effective. However, typically generalization is very limited, that is, the knowledge gained by the patient tends to be limited to the words actually trained, and there is at best very modest improvement in performance with untrained words (limited mainly to those that are semantically related to the trained words). Because generalization is can be limited with this approach, there currently exists no viable means of training patients on the full corpus of words (perhaps several thousand) they are likely to need in daily life. Two approaches might be taken to solving this problem: 1) develop cost effective means for providing training on several thousand words; and 2) develop alternative training methods, e.g., phonological therapy, that potentially could intrinsically generalize widely. The focus of this proposal is the second of these two approaches. Thus, the primary purpose of this Phase II clinical rehabilitation study was to examine the effect of a phonologic based treatment on confrontation naming by individuals with anomic aphasia. We used a single-subject ABA design replicated across ten participants. The primary research question asked if phonologic treatment would improve confrontation naming. Secondary research questions addressed the impact of treatment on 1) generalization to untrained behaviors such as discourse production; 2) retention effects at 3-months; 3) phonologic production and 4) nonword repetition (potential evidence of phoneme sequence knowledge acquisition)
Monitoring Home-Based Activity of Stroke Patients: A Digital Solution for Visuo-Spatial Neglect Evaluation
The possibility to prescribe home-based rehabilitation activity after stroke strongly increases the amount of exercises to perform, thus helping the maintenance of relearned skills, the completion of the rehabilitation program, the practice of physical and mental concentration. Even more important is the monitoring of the patient activity at home, as it is provided by the Remote Monitoring Validation Engineering System (ReMoVES) platform [1]. The present work refers to the implementation and integration in ReMoVES platform of a digital and web-based version of Albert\u2019s [2] and Line Bisection [3] tests devoted to visuo-spatial neglect evaluation and its remote monitoring. A statistical analysis devoted to validating test-retest reliability is proposed. Concurrent correlation between digital and traditional administration of the tests is presented, in order to evaluate the validity of the remote monitoring of the home-administration through ReMoVES platform
Aging, Aerobic Activity and Interhemispheric Communication
Recent studies have shown that during unimanual motor tasks, aging adults show bilateral recruitment of primary motor cortex (M1), while younger adults show a suppression of the ipsilateral motor cortex. Additional work has indicated that increased bilateral M1 recruitment in older adults may be deleterious when performing some motor tasks. However, higher levels of physical fitness are associated with improved dexterity and fitness may mitigate the loss of both inhibitory and excitatory communication in aging adults. The goal of this study was to assess dexterity and interhemispheric motor communication in physically fit and sedentary middle-age (40–60 years) right handed participants using tests of hand deftness and transcranial magnetic stimulation (TMS). To behaviorally assess the influence of interhemispheric communication on motor performance, participants also perform the coin rotation deftness task while maintaining pinch force with the opposite hand (bimanual condition). We correlated these behavioral measures with the ipsilateral silent period using TMS to assess interhemispheric inhibition. Our results show that the middle-aged adults who were physically fit had better dexterity of their right hand (finger tapping and peg-board). When performing the coin rotation task the fit group had no between hand differences, but the sedentary group’s left hand performance was inferior to the their right hand. We found that better dexterity correlated with ipsilateral silent period duration (greater inhibition) thereby supporting the postulate that fitness improves interhemispheric motor communication
Features of turbulence during wildland fires in forested and grassland environments
Fire-induced turbulence and the feedback into the fire, following ambient changes, differ for forested (sub-canopy) and grassland environments. Here, we synthesize observations from multiple experimental surface fires: two sub-canopy backing fires, one sub-canopy heading fire, and a grassland heading fire. We identify and compare the most essential coherent structures and processes of each case from the turbulent momentum fluxes and turbulent kinetic energy (TKE) budget terms. In the sub-canopy burns, turbulent eddies are strongest near the canopy top: high streamwise turbulent flux accompanies low cross-stream turbulent flux and vice versa. In the grassland fire, both streamwise and cross-stream eddies strengthen simultaneously until a certain height, informing a vertical length scale for the fire-influence. Moreover, the forward sweep from streamwise eddies assists in the fire spread by pushing hot gases towards unburnt fuel. In the sub-canopy fires, shear production and buoyancy production are more substantial near the canopy top for more intense fires, while their magnitudes decrease with decreasing fire intensity. At mid-canopy-height scales, buoyancy production dominates shear production, becoming the key mechanism for vertical transport of TKE. In the grassland fire, shear production dominates buoyancy production near the surface and is insignificant beyond a certain height relative to the flame length, while buoyancy production increases with height, becoming substantial further away from the surface. Turbulent transport terms are also active in both environments. For intense sub-canopy fires, there is a loss in TKE due to its expulsion to the boundary layer aloft via the transport term, compensated by a reversal process: TKE influx via the transport term. In the grassland fire, the transport term mimics this behavior until a certain height. The insights into the relative significance of the respective turbulent fluxes and TKE budget terms in each environment can help simplify the complex system of equations governing fire physics
The effects of constrained left versus right monocular viewing on the autonomic nervous system
Asymmetrical activation of right and left hemispheres differentially influences the autonomic nervous system. Additionally, each hemisphere primarily receives retinocollicular projections from the contralateral eye. To learn if asymmetrical hemispheric activation induced by monocular viewing would influence relative pupillary size and respiratory hippus variability (RHV), a measure of parasympathetic activity, healthy participants had their left, right or neither eye patched. Pupillary sizes were then recorded with infrared pupillography. Pupillary dilation was significantly greater with left than right eye viewing. RHV, however, was not different between eye viewing conditions. These differences in pupil dilatation may have been caused by relatively greater activation of the right hemispheric-mediated sympathetic activity induced by left monocular viewing or relatively greater deactivation of the left hemispheric-mediated parasympathetic activity induced by right eye patching. The absence of an asymmetry in RHV, however, suggests that hemispheric asymmetry of sympathetic activation was primarily responsible for this ocular asymmetry of pupil dilation
Incorporating Hydrologic Data and Ecohydrologic Relationships into Ecological Site Descriptions
The purpose of this paper is to recommend a framework and methodology for incorporating hydrologic data and ecohydrologic relationships in Ecological Site Descriptions (ESDs) and thereby enhance the utility of ESDs for assessing rangelands and guiding resilience-based management strategies. Resilience-based strategies assess and manage ecological state dynamics that affect state vulnerability and, therefore, provide opportunities to adapt management. Many rangelands are spatially heterogeneous or sparsely vegetated where the vegetation structure strongly influences infiltration and soil retention. Infiltration and soil retention further influence soil water recharge, nutrient availability, and overall plant productivity. These key ecohydrologic relationships govern the ecologic resilience of the various states and community phases on many rangeland ecological sites (ESs) and are strongly affected by management practices, land use, and disturbances. However, ecohydrologic data and relationships are often missing in ESDs and state-and-transition models (STMs). To address this void, we used literature to determine the data required for inclusion of key ecohydrologic feedbacks into ESDs, developed a framework and methodology for data integration within the current ESD structure, and applied the framework to a select ES for demonstrative purposes. We also evaluated the utility of the Rangeland Hydrology and Erosion Model (RHEM) for assessment and enhancement of ESDs based in part on hydrologic function. We present the framework as a broadly applicable methodology for integrating ecohydrologic relationships and feedbacks into ESDs and resilience-based management strategies. Our proposed framework increases the utility of ESDs to assess rangelands, target conservation and restoration practices, and predict ecosystem responses to management. The integration of RHEM technology and our suggested framework on ecohydrologic relations expands the ecological foundation of the overall ESD concept for rangeland management and is well aligned with resilience-based, adaptive management of US rangelands. The proposed enhancement of ESDs will improve communication between private land owners and resource managers and researchers across multiple disciplines in the field of rangeland management
Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial
Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D
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