Generalized Perceptual Linear Prediction (gPLP) Features for Animal Vocalization Analysis

A new feature extraction model, generalized perceptual linear prediction (gPLP), is developed to calculate a set of perceptually relevant features for digital signal analysis of animalvocalizations. The gPLP model is a generalized adaptation of the perceptual linear prediction model, popular in human speech processing, which incorporates perceptual information such as frequency warping and equal loudness normalization into the feature extraction process. Since such perceptual information is available for a number of animal species, this new approach integrates that information into a generalized model to extract perceptually relevant features for a particular species. To illustrate, qualitative and quantitative comparisons are made between the species-specific model, generalized perceptual linear prediction (gPLP), and the original PLP model using a set of vocalizations collected from captive African elephants (Loxodonta africana) and wild beluga whales (Delphinapterus leucas). The models that incorporate perceptional information outperform the original human-based models in both visualization and classification tasks

Automatic Classification of African Elephant (\u3cem\u3eLoxodonta africana\u3c/em\u3e) Follicular and Luteal Rumbles

Recent research in African elephant vocalizations has shown that there is evidence for acoustic differences in the rumbles of females based on the phase of their estrous cycle (1). One reason for these differences might be to attract a male for reproductive purposes. Since rumbles have a fundamental frequency near 10Hz, they attenuate slowly and can be heard over a distance of several kilometers. This research exploits differences in the rumbles to create an automatic classification system that can determine whether a female rumble was made during the luteal or follicular phase of the ovulatory cycle. This system could be used as the basis for a non-invasive technique to determine the reproductive status of a female African elephant. The classification system is based on current state-of-the-art human speech processing systems. Standard features and models are applied with the necessary modifications to account for the physiological, anatomical and language differences between humans and African elephants. The long-term goal of this research is to develop a universal analysis framework and robust feature set for animal vocalizations that can be applied to many species. This research represents an application of this framework. The vocalizations used for this study were collected from a group of three female captive elephants. The elephants are fitted with radio-transmitting microphone collars and released into one of three naturalistic yards on a daily basis. Although this data collection setup is good for determining the speaker of each vocalization, it suffers from many potential noise sources such as RF interference, passing vehicles, and the flapping of the elephant’s ears against the collar

Effect of age and nutrient restriction pre partum on beef suckler cow serum immunoglobulin concentrations, colostrum yield, composition and immunoglobulin concentration and immune status of their progeny

peer-reviewedThe effect of cow age (multiparous (MP) v. primiparous (PP)) and nutritional restriction pre partum (grass silage ad libitum v. straw only ad libitum for the last 15 (s.d. 3.3) days of gestation) on cow serum immunoglobulin (Ig) concentration, on colostrum yield, composition and Ig concentration and on calf serum Ig concentrations (at ~8 and 48 h post partum) using spring-calving Limousin Holstein-Friesian cows and their progeny was studied over 3 years. The method of colostrum administration (stomach tube vs. assisted suckling within 1 h post partum) on calf immune status was also investigated. When feeding colostrum the target was to give each calf 50 mL per kg birthweight via stomach tube. Colostrum yield and Ig concentration were measured following administration of oxytocin and hand-milking of half (Experiments 1 and 2) or the complete udder (Experiment 3). Following an 8-h period after birth during which suckling was prevented a further colostrum sample was obtained. There was no significant difference in first milking colostrum Ig subclass concentrations between the within-quarter fractions or between the front and rear quarters of the udder in either MP or PP cows. Colostrum Ig subclass concentrations at second milking were 0.46 to 0.65 of that at first milking. Compared to MP cows offered silage, colostrum yield and the mass of colostrum IgG1, IgG2, IgM, IgA and total Ig produced was lower (P < 0.001) for PP cows and the mass of IgG1, IgM and total Ig produced was lower (P < 0.05) for MP cows offered straw. Calves from PP cows and MP cows offered straw had significantly lower serum IgG1 and total Ig concentrations at 48 h post partum than calves from MP cows offered silage but there was no difference (P > 0.05) between colostrum feeding methods. In conclusion, calves from PP cows and MP cows offered straw had a lower humoral immune status than those from MP cows offered grass silage

Effect of suckler cow genotype on cow serum immunoglobulin (Ig) levels, colostrum yield, composition and Ig concentration and subsequent immune status of their progeny

peer-reviewedSurvival of the neonatal calf is largely dependent on humoral immunity. The objective of three experiments reported here was to compare cow serum immunoglobulin (Ig) concentration, colostrum yield, composition and Ig concentration and calf serum Ig concentrations at ~8- and 48-h post partum of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows and their progeny. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and silage ad libitum in Experiment 3. In Experiment 1 calves were assisted to suckle after parturition. In Experiments 2 and 3, colostrum yield and Ig concentration were measured following administration of oxytocin and hand milking of half or the complete udder, respectively. It was intended to feed each calf 50 ml (Experiment 2) or 40 ml (Experiment 3) of colostrum per 1 kg birth weight via stomach tube. Following an 8-h period, during which suckling was prevented, a further colostrum sample was obtained. The decrease in cow serum IgG1 concentration pre partum was greater (P < 0.05) in BF cows than C cows. In comparison to BF cows, C cows had a lower colostrum yield (P < 0.001) and the colostrum had lower concentrations of dry matter (P < 0.01), crude protein (P < 0.05), fat (P < 0.05), IgG1 (P = 0.06), IgG2 (P < 0.01), IgM (P < 0.01) and Ig total (P < 0.05). The mass of IgG1, IgG2, IgM, IgA and Ig total in the colostrum produced was significantly lower for C cows than BF cows. Calves from C cows had significantly lower serum Ig subclass concentration at 48-h post partum than calves from BF cows. In conclusion, due to a lower Ig mass produced by their dams, calves from C cows had a lower humoral immune status than those from BF cowsTeagasc Walsh Fellowship Programm

Catastrophic Decays of Compactified Space-Times

Witten long ago pointed out that the simplest Kaluza-Klein theory, without supersymmetry, is subject to a catastrophic instability. There are a variety of string theories which are potentially subject to these instabilities. Here we explore a number of questions: how generic are these instabilities? what happens when a potential is generated on the moduli space? in the presence of supersymmetry breaking, is there still a distinction between supersymmetric and non-supersymmetric states?Comment: Typos corrected, references adde

The Formation of Giant Elliptical Galaxies and Their Globular Cluster Systems

The bimodal globular cluster (GC) metallicity distributions of many giant elliptical galaxies are often cited as evidence for the formation of such galaxies through mergers involving gas-rich spirals. In such models, the metal- rich GCs are assumed to have formed during the merger process. We explore an alternative possibility: that these metal-rich clusters represent the galaxy's intrinsic GC population and that the metal-poor component of the observed GC metallicity distribution arises from the capture of GCs from other galaxies, either through mergers or through tidal stripping. Starting with plausible assumptions for the initial galaxy luminosity function and for the dependence of GC metallicity on parent galaxy luminosity, we show that the growth of a pre-existing seed galaxy through mergers and tidal stripping is accompanied by the capture of metal-poor GCs whose properties are similar to those which are observed to surround giant ellipticals. We describe a method of using the observed number of metal-poor and metal-rich GCs to infer the merger histories of individual elliptical galaxies, and use this technique to derive limits on the number of galaxies and total luminosity accreted to date by M49. We argue that although GC specific frequency is conserved in galaxy mergers, the same may not be true of tidal stripping by the mean field of the host galaxy cluster. Comparisons of model GC metallicity distributions and specific frequencies to those observed for the well-studied galaxies M49 and M87 show that it is possible to explain their bimodal GC metallicity distributions and discordant specific frequencies without resorting to the formation of new GCs in mergers or by invoking multiple bursts of GC formation.Comment: 39 pages AAS Latex and 10 postscript figures. Also available at http://astro.caltech.edu/~pc. Accepted for publication in the Astrophysical Journa

Faithful Estimation of Dynamics Parameters from CPMG Relaxation Dispersion Measurements

This work examines the robustness of fitting of parameters describing conformational exchange (kex, pa/b, and Δω) processes from CPMG relaxation dispersion data. We have analyzed the equations describing conformational exchange processes for the intrinsic inter-dependence of their parameters that leads to the existence of multiple equivalent solutions, which equally satisfy the experimental data. We have used Monte-Carlo simulations and fitting to the synthetic data sets as well as the direct 3-D mapping of the parameter space of kex, pa/b, and Δω to quantitatively assess the degree of the parameter inter-dependence. The demonstrated high correlation between parameters can preclude accurate dynamics parameter estimation from NMR spin-relaxation data obtained at a single static magnetic field. The strong parameter inter-dependence can readily be overcome through acquisition of spin-relaxation data at more than one static magnetic field thereby allowing accurate assessment of conformational exchange properties

Automatic Classification and Speaker Identification of African Elephant (\u3cem\u3eLoxodonta africana\u3c/em\u3e) Vocalizations

A hidden Markov model (HMM) system is presented for automatically classifying African elephant vocalizations. The development of the system is motivated by successful models from human speech analysis and recognition. Classification features include frequency-shifted Mel-frequency cepstral coefficients (MFCCs) and log energy, spectrally motivated features which are commonly used in human speech processing. Experiments, including vocalization type classification and speaker identification, are performed on vocalizations collected from captive elephants in a naturalistic environment. The system classified vocalizations with accuracies of 94.3% and 82.5% for type classification and speaker identification classification experiments, respectively. Classification accuracy, statistical significance tests on the model parameters, and qualitative analysis support the effectiveness and robustness of this approach for vocalization analysis in nonhuman species