Integrated saccade latency as a measure of fatigue

INTRODUCTION: High workload, long working hours and inadequate sleep patterns can have deleterious effects on an individual’s performance. Fatigue is often linked with compromised cognitive and motor function. Our information processing system becomes overloaded and unable to monitor and suppress irrelevant information. Subsequent changes in oculomotor parameters and cortical processing times may therefore provide useful biomarkers to assess one’s state of fatigue. We propose a new non-invasive method to quantify fatigue by measuring Eye Movement And Intrinsic Latencies (EMAIL) without the use of any eye-tracking equipment. METHODS: The test is easy to perform and employs a Landolt C flanked by ring distractors. The test is presented at an eccentricity of 8°, randomly on either side of fixation point within ±5° elevation. The measurement variable is the time of presentation, δT. The subject’s task is to saccade to the peripheral target, register the orientation of the gap and respond by pressing one of four buttons. The EMAIL test measures the presentation time, δT, the subject needs to detect the peripheral target, generate an appropriate eye-movement and register the orientation of the gap. RESULTS: The EMAIL test was used to measure the stimulus presentation times needed to achieve 73% correct responses (using a one up, two down staircase). These times were subject specific and ranged from 165 to 200ms in the absence of fatigue. We investigated how, δT, is affected by exposure to other visually demanding tasks and levels of controlled fatigue. Measured integrated oculomotor responses such as latencies and visual processing times were found to increase significantly following demanding visual tasks by as much as 20ms, but only when fatigued. Preliminary findings using the EMAIL test also show that this technique can be used to investigate the effect of stimulants such as caffeine and depressants, such as alcohol. CONCLUSIONS: The EMAIL test provides a simple method to measure oculomotor parameters and to investigate how these are affected by fatigue. This method can be incorporated in the overall safety management system that is often needed in a number of work areas that involve visually-demanding and safety-critical tasks. The measured parameters provide information about an individual’s level of alertness and may also be of relevance in other industries in order to evaluate drugs developed to control fatigue

Lattice Boltzmann Simulation on Reactive Transport of Calcite Dissolution by Injecting CO2-saturated Brine during Sequestration

CO2 as a kind of greenhouse gas has a greatly adverse impact on theenvironment, and fixing carbon into saline aquifers effectively alleviates theeffect it brings. In the present study, the calcite dissolution during sequestrationnear wellbores at different temperatures is explored to elucidate the mesoscalemechanism of reaction transport during this process and the evaluation ofhydraulic properties with time that affects the injectivity of CO2-saturated brine.A multi-component lattice Boltzmann method coupled fluid flow, masstransport, heterogeneous reaction, and structure evolution is proposed toquantitively study the reaction transport of calcite dissolution near wellbores. Aspecial solution included the general lattice Boltzmann concentration boundarycondition and Volume of Pixel method is utilized to model the dissolutionreaction. The influence of temperature on reaction dynamics in porous media isanalyzed by exerting the Arrhenius expression, and the concentration distributionof H+ and Ca2+ is captured to reflect the dissolution front directly. Moreover, theevaluated hydraulic properties characterize the effect of the dissolution reactionon the brine injectivity.Since the reaction rate of calcite dissolution increases with temperature, thedissolution node of calcite is proportional to the temperature at a constantpressure difference. And the dissolution node indicating the released volume ofCa2+ which is a key reactant for the mineral trapping is summed to estimate thesequestration result. Furthermore, the dissolution front observed from the porescalesimulation is heterogenous due to a higher velocity, and the dissolutionpattern of all cases is identified as the wormholing dissolution, which means thatthe increasing porosity during the calcite dissolution has a great contribution tothe permeability. Admittedly, the increasing temperature during sequestration isconducive to calcite dissolution and changes in hydraulic properties. Forsequestration operation, the high-temperature formation is recommended for boththe injectivity and the subsequent mineral trapping.This work provides theoretical and pragmatic guidance to operators to designCO2-saturated brine injection in saline aquifers. Furthermore, the results can alsopromote cognition of the calcite dissolution for sequestration at differenttemperature

BAllC and BAllCools: Efficient formatting and operating for single-cell DNA methylation data

MOTIVATION: With single-cell DNA methylation studies yielding vast datasets, existing data formats struggle with the unique challenges of storage and efficient operations, highlighting a need for improved solutions. RESULTS: BAllC (Binary All Cytosines) emerges as a tailored format for methylation data, addressing these challenges. BAllCools, its complementary software toolkit, enhances parsing, indexing, and querying capabilities, promising superior operational speeds and reduced storage needs. AVAILABILITY AND IMPLEMENTATION: https://github.com/jksr/ballcools

MPprimer: a program for reliable multiplex PCR primer design

<p>Abstract</p> <p>Background</p> <p>Multiplex PCR, defined as the simultaneous amplification of multiple regions of a DNA template or multiple DNA templates using more than one primer set (comprising a forward primer and a reverse primer) in one tube, has been widely used in diagnostic applications of clinical and environmental microbiology studies. However, primer design for multiplex PCR is still a challenging problem and several factors need to be considered. These problems include mis-priming due to nonspecific binding to non-target DNA templates, primer dimerization, and the inability to separate and purify DNA amplicons with similar electrophoretic mobility.</p> <p>Results</p> <p>A program named MPprimer was developed to help users for reliable multiplex PCR primer design. It employs the widely used primer design program Primer3 and the primer specificity evaluation program MFEprimer to design and evaluate the candidate primers based on genomic or transcript DNA database, followed by careful examination to avoid primer dimerization. The graph-expanding algorithm derived from the greedy algorithm was used to determine the optimal primer set combinations (PSCs) for multiplex PCR assay. In addition, MPprimer provides a virtual electrophotogram to help users choose the best PSC. The experimental validation from 2× to 5× plex PCR demonstrates the reliability of MPprimer. As another example, MPprimer is able to design the multiplex PCR primers for DMD (dystrophin gene which caused Duchenne Muscular Dystrophy), which has 79 exons, for 20×, 20×, 20×, 14×, and 5× plex PCR reactions in five tubes to detect underlying exon deletions.</p> <p>Conclusions</p> <p>MPprimer is a valuable tool for designing specific, non-dimerizing primer set combinations with constrained amplicons size for multiplex PCR assays.</p

U-Sodar: Noncontact Vital Sign Detection Technology Based on Ultrasonic Radar

Amidst the global aging trend and a growing emphasis on healthy living, there is an increased demand for unobtrusive home health monitoring systems. However, the current mainstream detection methods in this regard suffer from low privacy trust, poor electromagnetic compatibility, and high manufacturing costs. To address these challenges, this paper introduces a noncontact vital signal collection device using Ultrasonic radar (U-Sodar), including a set of hardware based on a three-transmitter four-receiver Multiple Input Multiple Output (MIMO) architecture and a set of signal processing algorithms. The U-Sodar local oscillator uses frequency division technology with low phase noise and high detection accuracy; the receiver employs front-end direct sampling technology to simplify the involved structure and effectively reduce external noise, and the transmitter uses an adjustable PWM direct drive to emit various ultrasonic waveforms, possessing software-defined ultrasonic system characteristics. The signal processing algorithm of U-Sodar adopts the graph processing technique of signal chord length and realizes accurate recovery of signal phase under 5 dB Signal-to-Noise Ratio (SNR) using picture filtering and then reconstruction. Experimental tests on the U-Sodar system demonstrated its anti-interference and penetration capabilities, proving that ultrasonic penetration relies on material porosity rather than intermedium vibration conduction. The minimum measurable displacement for a given SNR with correct demodulation probability is also derived. The results of actual human vital sign signal measurement experiments indicate that U-Sodar can accurately measure respiration and heartbeat at 3.0 m and 1.5 m, respectively, and the heartbeat waveforms can be measured within 1.0 m. Overall, the experimental results demonstrate the feasibility and application potential of U-Sodar in noncontact vital sign detection

Beneficiation Experiment of a Carbonate Fluorite Ore in Guizhou

This is an essay in the field of mineral processing engineering. There is a 40.56% CaF2 in a Carbonate fluorite ore in Guizhou. The ore composition is complex and the content of carbonate gangue minerals is high. The flotation experiment was carried out with a new collector LY-14 developed by ourselves. Using the closed-circuit test process of "one coarse, six fine and one sweep", under the conditions of grinding fineness of -0.074 mm, content of 81.42%, dosage of Na2CO3 of 1 200 g/t, dosage of acidified sodium silicate of 1 200 g/t, dosage of tannin of 100 g/t and dosage of collector LY-14 of 600 g/t, fluorite concentrate with CaF2 grade of 96.35% and CaF2 recovery of 91.47% was obtained

A Recalibrated Molecular Clock and Independent Origins for the Cholera Pandemic Clones

Cholera, caused by Vibrio cholerae, erupted globally from South Asia in 7 pandemics, but there were also local outbreaks between the 6th (1899–1923) and 7th (1961–present) pandemics. All the above are serotype O1, whereas environmental or invertebrate isolates are antigenically diverse. The pre 7th pandemic isolates mentioned above, and other minor pathogenic clones, are related to the 7th pandemic clone, while the 6th pandemic clone is in the same lineage but more distantly related, and non-pathogenic isolates show no clonal structure. To understand the origins and relationships of the pandemic clones, we sequenced the genomes of a 1937 prepandemic strain and a 6th pandemic isolate, and compared them with the published 7th pandemic genome. We distinguished mutational and recombinational events, and allocated these and other events, to specific branches in the evolutionary tree. There were more mutational than recombinational events, but more genes, and 44 times more base pairs, changed by recombination. We used the mutational single-nucleotide polymorphisms and known isolation dates of the prepandemic and 7th pandemic isolates to estimate the mutation rate, and found it to be 100 fold higher than usually assumed. We then used this to estimate the divergence date of the 6th and 7th pandemic clones to be about 1880. While there is a large margin of error, this is far more realistic than the 10,000–50,000 years ago estimated using the usual assumptions. We conclude that the 2 pandemic clones gained pandemic potential independently, and overall there were 29 insertions or deletions of one or more genes. There were also substantial changes in the major integron, attributed to gain of individual cassettes including copying from within, or loss of blocks of cassettes. The approaches used open up new avenues for analysing the origin and history of other important pathogens

A Demographic Profile of Independently Incorporated Native American Foundations and Selected Funds in the United States

This report gives basic demographic information on 60 grantmaking entities grouped into three categories: 1) Native foundations that are independently incorporated; 2) 501c3 Native organizations; and 3) tribal funds. These categories capture the variety of Native controlled approaches currently at work in the field