Monitoring Escape and Feeding Behaviours of Cruiser Fish by Inertial and Magnetic Sensors

<div><p>A method was developed and applied for monitoring two types of fast-start locomotion (feeding and escape) of a cruiser fish, Japanese amberjacks <i>Seriola quinqueradiata</i>. A data logger, which incorporated a 3-axis gyroscope, a 3-axis accelerometer and a 3-axis magnetometer, was attached to the five fish. The escape, feeding and routine movements of the fish, which were triggered in tank experiments, were then recorded by the data logger and video cameras. The locomotor variables, calculated based on the high resolution measurements by the data logger (500 Hz), were investigated to accurately detect and classify the types of fast-track behaviour. The results show that fast-start locomotion can be detected with a high precision (0.97) and recall rate (0.96) from the routine movements. Two types of fast-start movements were classified with high accuracy (0.84). Accuracy was greater if the data were obtained from the data logger, which combined an accelerometer, a gyroscope and a magnetometer, than if only an accelerometer (0.80) or a gyroscope (0.66) was used.</p></div

Structures of the B-form (A) and cisplatin-induced bent (B) DNA duplexes.

<p>The duplexes with the PDB codes of 2K0V and 1A84 are shown. The distances between the C2’ atoms of the modified nucleosides were calculated using the PyMOL 1.7.1 software.</p

HPLC analysis of disulfide bond formation in duplexes containing the cisplatin adduct.

<p>(<b>A</b>–<b>F</b>) Chromatograms of the duplexes, in which × represents cisplatin, after the reactions for the indicated length of time. The y-axis of each chromatogram was normalized. The cross-linked products and the sulfinic acid-containing oligonucleotides are indicated by an arrow and an asterisk, respectively, and the results of the DTT treatment of the products are shown in red. (<b>G</b>) Comparison of the product formation between GG-6 and Pt-6. The product peak areas in panels <b>B</b> and <b>E</b> were quantified.</p

Example image sequences of typical a) escape and b) feeding movements.

<p>Full videos are available as the supporting information (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079392#pone.0079392.s003" target="_blank">Movies S1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079392#pone.0079392.s004" target="_blank">S2</a>).</p

Summary of the means (sem) of the axis-specific variables derived from the acc-only dataset for classifying escape (N = 41) or feeding (N = 41) movements.

a<p>t test or Wilcoxon singed-rank test was used.</p>b<p>NS indicates no significance.</p><p>The statistical differences between the values of these variables during escape and feeding behaviours are also shown.</p

HPLC analysis of disulfide bond formation in duplexes containing the (6–4) photoproduct.

<p>C4 and C3 represent the 4-mercaptobutyl and 3-mercaptopropyl groups, respectively. The y-axis of each chromatogram was normalized. The cross-linked products are indicated by an arrow, and the results of the DTT treatment of the products are shown in red.</p

Effect of the linker length on the rate of the disulfide bond formation.

<p>(<b>A</b>) Pt-6 (C4) (open circles) and Pt-6 (C3) (filled circles); (<b>B</b>) AP-6 (C4) (open squares) and AP-6 (C3) (filled squares); (<b>C</b>) 64–6 (C4) (open triangles) and 64–6 (C3) (filled triangles). The dashed and continuous lines represent the decrease of the starting materials and the increase of the cross-linked products, respectively, and the standard errors are shown. The curve fitting was performed with the Origin 9.1 software, and the kinetic constants for the product formation are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117798#pone.0117798.t001" target="_blank">Table 1</a>.</p

Histograms of axis-specific variables for classifying escape or feeding movements.

<p>Three types of axis-specific variables were used for the classification of the escape (N = 41) or feeding (N = 41) movements: a) acc-only, b) gyro-only, and c) all-combined datasets.</p

Summary of the classification rate of escape and feeding movements using the inter-axial variables.

<p>The variables used for the classification are also shown.</p

Decision trees for classifying escape or feeding movements by inter-axial variables.

<p>Three types of inter-axial variables were used for the classification of the escape (N = 41) or feeding (N = 41) movements: a) acc-only, b) gyro-only, and c) all-combined datasets. The numbers in the box of the categories of FS indicate the percentage of events that were categorised into each movement type and the percentage of these events that were miscategorised (after the diagonal).</p