The phosphopantetheinyl transferase which is essential for mitochondrial essential fatty acid biosynthesis

This article presents an asymptotically optimal technique for estimating environmental parameters from ocean ambient noise. Noise from wind and breaking waves propagates through the water column and reflects off the bottom over a wide range of angles and frequencies and, in doing so, imparts information about the environment to the noise covariance matrix for a receiver array. Most environmental estimation techniques focus on spatial filtering methods aimed at recovering the vertical noise directionality. However, an often overlooked fact is that the noise covariance matrix fully characterizes the probability density function of each snapshot, which forms the basis for an information-theoretic approach. In this light, it is possible to obtain the theoretical bounds on optimal estimator performance while also providing a basis for assessing the utility of different parameterization schemes. Most importantly, it provides a natural definition for a maximum likelihood estimator that meets the optimal bounds in an asymptotic sense. This technique outperforms beamforming-based methods by a significant margin. It also remains unbiased in the presence of strong white noise, is tolerant to array tilt, can operate beyond the array design frequency, but does suffer greater sensitivity to model mismatch. These trade-offs are explored with simulations and analyses of experimental data.In this paper, the phase response of fiber Fabry-Pérot cavity-based fiber optic microphones (FFPC-FOMs) is discussed through an analysis of the results of simulation and experiments. The phase difference of FFPC-FOMs mainly originates from two aspects different phase lags of the mechanical-acoustic systems and different quadrature working points (Q*) on interference curves. The former is analyzed by an impedance-type analogous circuit, and the simulation results reveal that the change in cavity length and resonance frequency in a large range have an insignificant influence on the phase difference. The latter shows a unique effect on the phase difference and causes the phase of FFPC-FOMs to be either in or out of phase. The phase differences of four samples of FFPC-FOMs with different cavity lengths and resonance frequencies are measured in the frequency range 50 Hz-4 kHz. Experimental results of the phase difference are well consistent with simulation results. All samples of FFPC-FOMs can be divided into two groups one is near 0° and the other is near 180°. In addition, the FFPC-FOMs in each group have good phase consistency for the array applications.This paper presents a simple and easy-to-use method of creating a time-varying signal of the degree of nasalization in vowels, generated from acoustic features measured in oral and nasalized vowel contexts. The method is presented for separate models constructed using two sets of acoustic features (1) an uninformed set of 13 Mel-frequency cepstral coefficients (MFCCs) and (2) a combination of the 13 MFCCs and a phonetically informed set of 20 acoustic features of vowel nasality derived from previous research. Both models are compared against two traditional approaches to estimating vowel nasalization from acoustics A1-P0 and A1-P1, as well as their formant-compensated counterparts. Data include productions from six speakers of different language backgrounds, producing 11 different qualities within the vowel quadrilateral. The results generated from each of the methods are compared against nasometric measurements, representing an objective "ground truth" of the degree of nasalization. The results suggest that the proposed method is more robust than conventional acoustic approaches, generating signals which correlate strongly with nasometric measures across all vowel qualities and all speakers and accurately approximate the time-varying change in the degree of nasalization. Finally, an experimental example is provided to help researchers implement the method in their own study designs.This paper presents the Acoustics Apps, an e-learning platform that offers an interactive and playful environment for teaching and learning the principles of acoustics and vibration. The Acoustics Apps address the increasing demand for digitized teaching methods, which might be suitable for home schooling or as a complement to physical experiments by adding interactive simulation. The apps combine learning by experimenting, observing, and exploring using state-of-the-art scientific methods and numerical simulations. The ability to visualize and control acoustic phenomena facilitates understanding of the relevant physical principles. The apps are designed to be used intuitively and can be tailored to suit the existing knowledge of the user. As such, a wide range of users can benefit from this learning aid. It has been developed to allow barrier-free access to modern educational tools, requiring only a device with a browser and Internet access. The necessary computing power is provided by an external server using the COMSOL ServerTM technology. The Acoustics Apps are freely available for academic and teaching purposes at apps.vib.mw.tum.de.The duplex sonar model of humpback whale song proposes that broadband units within songs function differently from narrowband units. Specifically, this model suggests that singing humpback whales interleave constant frequency (CF) units, which can generate prolonged reverberation focused at specific frequencies, with less reverberant broadband units that minimally overlap with the focal frequencies of preceding and following CF units (referred to as spectral interleaving) to increase the efficacy of song as a sonar source. Here, it is shown that singers recorded off the coast of Hawaii in 2015 devoted most of their time singing to spectrally interleaving broadband elements of units around quasi-CF components that consistently generated persistent reverberant tails. Singers maintained reverberant CF streams in specific frequency bands when units contained broadband elements and when singers switched from producing pairs of alternating reverberant units to producing a single reverberant unit. check details Additionally, singers showed the ability to flexibly control where acoustic energy was concentrated within broadband components in ways that minimized spectral overlap with the focal frequencies of reverberant tails.