What is the Most Sensitive Measure of Water Maze Probe Test Performance?

The water maze is commonly used to assay spatial cognition, or, more generally, learning and memory in experimental rodent models. In the water maze, mice or rats are trained to navigate to a platform located below the water's surface. Spatial learning is then typically assessed in a probe test, where the platform is removed from the pool and the mouse or rat is allowed to search for it. Performance in the probe test may then be evaluated using either occupancy-based (percent time in a virtual quadrant [Q] or zone [Z] centered on former platform location), error-based (mean proximity to former platform location [P]) or counting-based (platform crossings [X]) measures. While these measures differ in their popularity, whether they differ in their ability to detect group differences is not known. To address this question we compiled five separate databases, containing more than 1600 mouse probe tests. Random selection of individual trials from respective databases then allowed us to simulate experiments with varying sample and effect sizes. Using this Monte Carlo-based method, we found that the P measure consistently outperformed the Q, Z and X measures in its ability to detect group differences. This was the case regardless of sample or effect size, and using both parametric and non-parametric statistical analyses. The relative superiority of P over other commonly used measures suggests that it is the most appropriate measure to employ in both low- and high-throughput water maze screens

Squeezed Light Generation in Nonlinear System with Chaotic Dynamics

The squeezing in a nonlinear system with chaotic dynamics is considered. The model describing interaction of collection of two-level atoms with a single-mode of self-consistent field and an external field is analyzed. It is shown that in the semiclassical limit, in contrast to the regular behaviour, the chaotic dynamics result in: (i) an increase in squeezing, (ii) unstable squeezing and contraction of time intervals of squeezing on large enough times. The possibility of the experimental observation of the described effects is discussed.Comment: 12 pages, RevTEX (EPSF-style), 6 figure

Development and Validation of a Sensitive Entropy-Based Measure for the Water Maze

In the water maze, mice are trained to navigate to an escape platform located below the water's surface, and spatial learning is most commonly evaluated in a probe test in which the platform is removed from the pool. While contemporary tracking software provides precise positional information of mice for the duration of the probe test, existing performance measures (e.g., percent quadrant time, platform crossings) fail to exploit fully the richness of this positional data. Using the concept of entropy (H), here we develop a new measure that considers both how focused the search is and the degree to which searching is centered on the former platform location. To evaluate how H performs compared to existing measures of water maze performance we compiled five separate databases, containing more than 1600 mouse probe tests. Random selection of individual trials from respective databases then allowed us to simulate experiments with varying sample and effect sizes. Using this Monte Carlo-based method, we found that H outperformed existing measures in its ability to detect group differences over a range of sample or effect sizes. Additionally, we validated the new measure using three models of experimentally induced hippocampal dysfunction: (1) complete hippocampal lesions, (2) genetic deletion of αCaMKII, a gene implicated in hippocampal behavioral and synaptic plasticity, and (3) a mouse model of Alzheimer's disease. Together, these data indicate that H offers greater sensitivity than existing measures, most likely because it exploits the richness of the precise positional information of the mouse throughout the probe test

Logistics Service Development based on the Geo2Tag and Smart-M3 Platforms

In this article we will talk about implementation of a logiltics service for a car fleet management based on LBS GeolTag and Smart Space Smart-MJ platforms. Each platform has its own role in the work of logistics service. AU car fleet location information is stored and processed by the GeolTag platform. A Smart-MJ platform performs service metadata analysis in the form of service ontology and knowledge reasoning of these data. This work is focused on analysis and development of a logiltics car fleet management service using GeolTag and Smart-MJ platforms. Currently, there are a different classes of geographic data processing applications of road traffic objects from In-Car LBS system, fleet management systems to a satellite monitoring system for vehicles of the country. The current solution will create a context-aware system for processing and reasoning smart space subjects geographic data using LBS GeolTag platform. The system will consist of a variety types of agents or services for a fleet management from various angles - manager,driver and client

Severe Bilateral Optic Neuropathy Secondary to Cobalt Toxicity in Genetically-Predisposed Individual

Cobalt toxicity can cause optic neuropathy, retinopathy, hearing loss, encephalopathy, hearing loss, cardiomyopathy, and hypothyroidism. Vision loss has been reported at levels ranging from 35 - 1078 ug/L and is likely caused by disruption of mitochondrial respiration. Leber's hereditary optic neuropathy is a mitochondrial disease that causes bilateral vision loss due to preferential atrophy of retinal ganglion cells of the papillomacular bundle. It is maternally-inherited with variable penetrance, and typically requires 50% heteroplasmy or greater to manifest

Leber's Hereditary Optic Neuropathy in Older Individuals Because of Increased Alcohol Consumption During the COVID-19 Pandemic

Backgeber's hereditary optic neuropathy (LHON) is a disorder affecting oxidative phosphorylation in mitochondria. A majority of affected patients are men of 15 to 35 years of age. Phenotypic penetrance of this condition is only 50% in man and 10% in women and increases if the cellular energy demands go up, with the most common risk factors being smoking and alcohol use. Methods: Revi of clinical features of 3 patients who were diagnosed with LHON in their sixth decade of life after doubling their alcohol intake during the recent COVID-19 pandemic. Results: All 3 pa ents were older than the age of 50 when they developed severe sequential visual loss. All have at least doubled their alcohol intake for at least 4 weeks preceding visual loss, and 2 who were smokers increased the number of cigarettes consumed daily because of the stress and boredom during the lockdowns triggered by the pandemic. Conclusions: Significant increase in substance abuse in the general population during the recent lockdowns to combat the COVID-19 pandemic is well documented. We report 3 patients older than the age of 50, one of them a woman, who developed severe bilateral visual loss due to LHON after doubling their alcohol consumption and increasing number of cigarettes smoked daily during the pandemic. Clinicians are reminded to consider LHON in the differential diagnosis when encountering older patients with bilateral sequential visual loss and to specifically inquire about alcohol use and cigarette smoking in these patients

Leber's Hereditary Optic Neuropathy in Older Individuals Because of Increased Alcohol Consumption During the COVID-19 Pandemic

Backgeber's hereditary optic neuropathy (LHON) is a disorder affecting oxidative phosphorylation in mitochondria. A majority of affected patients are men of 15 to 35 years of age. Phenotypic penetrance of this condition is only 50% in man and 10% in women and increases if the cellular energy demands go up, with the most common risk factors being smoking and alcohol use. Methods: Revi of clinical features of 3 patients who were diagnosed with LHON in their sixth decade of life after doubling their alcohol intake during the recent COVID-19 pandemic. Results: All 3 pa ents were older than the age of 50 when they developed severe sequential visual loss. All have at least doubled their alcohol intake for at least 4 weeks preceding visual loss, and 2 who were smokers increased the number of cigarettes consumed daily because of the stress and boredom during the lockdowns triggered by the pandemic. Conclusions: Significant increase in substance abuse in the general population during the recent lockdowns to combat the COVID-19 pandemic is well documented. We report 3 patients older than the age of 50, one of them a woman, who developed severe bilateral visual loss due to LHON after doubling their alcohol consumption and increasing number of cigarettes smoked daily during the pandemic. Clinicians are reminded to consider LHON in the differential diagnosis when encountering older patients with bilateral sequential visual loss and to specifically inquire about alcohol use and cigarette smoking in these patients

Extent of Transverse Sinus Stenosis Does Not Predict Visual Outcomes in Idiopathic Intracranial Hypertension

Transverse sinus stenosis (TSS) is the most sensitive radiological correlate for the presence of idiopathic intracranial hypertension (IIH). We aimed to investigate whether the degree of TSS, as determined via venography studies, can predict visual outcomes in patients with IIH

What is the most sensitive measure of water maze probe test performance?

The water maze is commonly used to assay spatial cognition, or, more generally, learning and memory in experimental rodent models. In the water maze, mice or rats are trained to navigate to a platform located below the water’s surface. Spatial learning is then typically assessed in a probe test, where the platform is removed from the pool and the mouse or rat is allowed to search for it. Performance in the probe test may then be evaluated using either occupancy-based (percent time in virtual quadrant [Q] or zone [Z] centered on former platform location), error-based (mean proximity to former platform location [P]) or counting-based (platform crossings [X]) measures. While these measures differ in their popularity, whether they differ in their ability to detect group differences is not known. To address this question we compiled 5 separate databases, containing more than 1600 mouse probe tests. Random selection of individual trials from respective databases then allowed us to simulate experiments with varying sample and effect sizes. Using this Monte Carlo-based method, we found that the P measure consistently outperformed the Q, Z and X measures in its ability to detect group differences. This was the case regardless of sample or effect size, and using both parametric and non-parametric statistical analyses. The relative superiority of P over other commonly used measures suggests that it is the most appropriate measure to employ in both low- and high-throughput water maze screens