To investigate how to accurately identify bee species using their sounds, we conducted acoustic analysis to identify three pollinating bee species (Apis mellifera , Bombus ardens , Tetralonia nipponensis ) and a hornet (Vespa simillima xanthoptera ) by their flight sounds. Sounds of the insects and their environment (background noises and birdsong) were recorded in the field. The use of fundamental frequency and mel-frequency cepstral coefficients to describe feature values of the sounds, and supported vector machines to classify the sounds, correctly distinguished sound samples from environmental sounds with high recalls and precision (0.96-1.00). At the species level, our approach could classify the insect species with relatively high recalls and precisions (0.7-1.0). The flight sounds of V.s. xanthoptera , in particular, were perfectly identified (precision and recall 1.0). Our results suggest that insect flight sounds are potentially useful for detecting bees and quantifying their activity. species classification / Hymenoptera / machine learning / acoustic analysis

To quantitatively examine the diurnal, or tidal, effects on dugong behavior, we employed passive acoustic observation techniques to monitor the animals. Automatic underwater sound monitoring systems for dugongs (AUSOMS-D) were deployed on the sea floor at depths of about 5 m south of Talibong Island, Thailand. The AUSOMS-D recorded underwater sound in stereo at a sampling frequency of 44.1 kHz for more than 116 consecutive hours. Dugong calls were automatically detected by newly developed software with a detection rate of 36.1% and a false alarm rate of 2.9%. In total, 3453 calls were detected during the 164 h of recording. The autocorrelation of the call rate indicated an attendance cycle of about 24 or 25 h, and the most frequent vocalizations were observed from 0300 to 0500 h. The calculated bearings of the sound sources, i.e., dugongs, were used as an indicator to track the relative numbers of dugongs during the monitoring periods.

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The rates of reaction of sodium borohydride with representative ketones in isopropyl alcohol have been determined at several temperatures, yielding values for the relative rates a t O", and for the enthalpies and entropies of activation. The relative rates decrease from acetone (1.00), to diethyl ketone (0.101) to di-n-propyl ketone (0.0291). Further lengthening of the chain has little effect: di-n-butyl ketone (0.0403) and di-n-hexyl ketone (0.0300). Branching of the alkyl groups also results in a rate reduction: acetone (1.00), methyl ethyl ketone (0.417), methyl isopropyl ketone (0.195), methyl t-butyl ketone (0.0815). The presence of two branched alkyl groups decreases the rate considerably beyond that estimated from the effect of a single branched group: acetone (1.00), diethyl ketone (O.lOl), diisopropyl ketone (0.00551), di-t-butyl ketone (0.000191).A modest decrease is observed with chain branching in the phenyl alkyl ketones, with a sudden large increase in the phenyl t-butyl derivative: acetophenone (0.136), phenyl ethyl ketone (0.0756); phenyl isopropyl ketone (0.0709); phenyl isobutyl ketone (0.0111), phenyl t-butyl ketone (3.47). The effect of the t-butyl group is attributed to its large steric requirements which force the acyl group from its preferred configuration, coplanar with the aromatic ring, causing a reduction in the resonance interactions and permitting the phenyl group to exert its normal -I inductive effect. The data are compared with the rates of solvolysis of the related tosylates to test the proposal that the ketones may be taken as reasonable models for carbonium ions of related structures.The marked decrease accompanying the introduction of two bulky groups is attributed to steric effects.

There is a potential trade-off between grouping and the optimizing of the energetic efficiency of individual locomotion. Although intermittent locomotion, e.g. glide and upward swimming (GAU), can reduce the cost of locomotion at the individual level, the link between the optimization of individual intermittent locomotion and the behavioural synchronization in a group, especially among members with different sizes, is unknown. Here, we continuously monitored the schooling behaviour of a negatively buoyant fish, Pacific bluefin tuna (N ¼ 10; 21.0 24.5 cm), for 24 h in an open-sea net cage using accelerometry. All the fish repeated GAU during the recording periods. Although the GAU synchrony was maintained at high levels (overall mean ¼ 0.62 for the cross-correlation coefficient of the GAU timings), larger fish glided for a longer duration per glide and more frequently than smaller fish. Similar-sized pairs showed significantly higher GAU synchrony than differently sized pairs. Our accelerometry results and the simulation based on hydrodynamic theory indicated that the advantage of intermittent locomotion in energy savings may not be fully optimized for smaller animals in a group when faced with the maintenance of group cohesion, suggesting that size assortative shoaling would be advantageous.