Driver drowsiness detection is a key technology that can prevent fatal car accidents caused by drowsy driving. The present work proposes a driver drowsiness detection algorithm based on heart rate variability (HRV) analysis and validates the proposed method by comparing with electroencephalography (EEG)-based sleep scoring. Methods: Changes in sleep condition affect the autonomic nervous system and then HRV, which is defined as an RR interval (RRI) fluctuation on an electrocardiogram trace. Eight HRV features are monitored for detecting changes in HRV by using multivariate statistical process control, which is a well known anomaly detection method. Result: The performance of the proposed algorithm was evaluated through an experiment using a driving simulator. In this experiment, RRI data were measured from 34 participants during driving, and their sleep onsets were determined based on the EEG data by a sleep specialist. The validation result of the experimental data with the EEG data showed that drowsiness was detected in 12 out of 13 pre-N1 episodes prior to the sleep onsets, and the false positive rate was 1.7 times per hour. Conclusion: The present work also demonstrates the usefulness of the framework of HRV-based anomaly detection that was originally proposed for epileptic seizure prediction. Significance: The proposed method can contribute to preventing accidents caused by drowsy driving.

An experiment was conducted to investigate the effects of phosphorus (P), citric acid (CA) and formic acid (FA) supplementation on growth and loading of nitrogen (N) and phosphorus (P) in juvenile yellowtail fed fish meal (FM) and alternate plant protein (APP) diets. Six diets designated as F49 (490 g kg )1 FM-based), F49 + P (490 g kg )1 FM with 5 g kg )1 inorganic P), F31 + CA (310 g kg )1 FM containing 200 g kg )1 APP with 5 g kg )1 CA), F31 + FA (310 g kg )1 FM having 200 g kg )1 APP with 4 g kg )1 FA), F23 + CA (230 g kg )1 FM containing 300 g kg )1 APP with 5 g kg )1 CA) and F23 + FA (230 g kg )1 FM having 300 g kg )1 APP with 4 g kg )1 FA) were formulated. Yellowtails were fed one of the diets for 12 weeks under on-site conditions at water temperature 22.0-27.0°C. F49 + P gave the best growth, while F23 + CA the lowest. Specific growth rate and feed conversion ratio of F31 + CA were similar with control group. Addition of CA to APP diets significantly increased retention of P; hence, its excretion was lowered. The results of this study suggest that FM could be replaced up to 70% with the addition of 5 g kg )1 CA to a low P-containing plant protein sources diet without inorganic P supplementation in juvenile yellowtail diets, which in turn would enable a reduction in environmental pollution from aquafeeds.

A feeding experiment was conducted to investigate the e¡ect of organic acids and/or lipid supplementation on growth, utilization and environmental loading of nitrogen (N) and phosphorus (P) in juvenile yellowtail fed ¢shmeal (FM) and plant protein (PP) diets. Six diets as FM (FM-based), FM1P (FM with inorganic P), FM1L (FM with lipid), PP1CA (PP with citric acid), PP1L1CA (PP with lipid and citric acid) and PP1L1FA (PP with formic acid) were formulated.Yellowtails were fed each of the diets in duplicate groups; once a day,6 days a week to near satiation at water tem-perature19.0^25.0 1C for16 weeks. Fishmeal with inorganic P gave the best growth while PP1L1FA the lowest. However, growth increased in PP1CA and PP1L1CA. Addition of lipid signi¢cantly increased N and P retention resulting in signi¢cant reduction in N and P excretion. Citric acid and FA supplementation to PP diets also increased retention of P; hence, its excretion was lowered. Thus, CA, FA and lipid in juvenile yellowtail diets can help to partially replace FM with PP sources and reduce inorganic P use to minimize environmental loading from aquafeeds.

An asymmetric distribution of phospholipids in the membrane bilayer is inseparable from physiological functions, including shape preservation and survival of erythrocytes, and by implication other cells. Aminophospholipids, notably phosphatidylserine (PS), are confined to the inner leaflet of the erythrocyte membrane lipid bilayer by the ATP-dependent flippase enzyme, ATP11C, counteracting the activity of an ATP-independent scramblase. Phospholipid scramblase 1 (PLSCR1), a single-transmembrane protein, was previously reported to possess scrambling activity in erythrocytes. However, its function was cast in doubt by the retention of scramblase activity in erythrocytes of knockout mice lacking this protein. We show that in the human erythrocyte PLSCR1 is the predominant scramblase and by reconstitution into liposomes that its activity resides in the transmembrane domain. At or below physiological intracellular calcium concentrations, total suppression of flippase activity nevertheless leaves the membrane asymmetry undisturbed. When liposomes or erythrocytes are depleted of cholesterol (a reversible process in the case of erythrocytes), PS quickly appears at the outer surface, implying that cholesterol acts in the cell as a powerful scramblase inhibitor. Thus, our results bring to light a previously unsuspected function of cholesterol in regulating phospholipid scrambling.

Membrane microdomains enriched in cholesterol and sphingolipids and containing specific membrane proteins are designated as lipid rafts. Lipid rafts have been implicated in cell signaling pathways in various cell types. Heterotrimeric guanine nucleotide-binding protein (Gsa) has been shown to be a raft component of erythrocytes and has been implicated in cell signaling. Rafts are isolated as detergent-resistant microdomains (DRMs) for biochemical analysis. Cholesterol depletion is widely used to disrupt raft structures to study their function in biological membranes. In the present study, we developed an alternate strategy for disrupting raft structures without altering membrane cholesterol content. Lidocaine hydrochloride, an amphipathic local anesthetic, is shown to reversibly disrupt rafts in erythrocyte membranes and alter the Gsa dependent signal transduction pathway. These findings provide evidence for the presence of rafts while maintaining normal cholesterol content in erythrocyte membranes and confirm a role for raft-associated Gsa in signal transduction in erythrocytes. Am. J. Hematol. 83:371-375, 2008. V