A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

Urban Economics and Entrepreneurship

Research on entrepreneurship often examines the local dimensions of new business formation. The local environment influences the choices of entrepreneurs; entrepreneurial success influences the local economy. Yet modern urban economics has paid relatively little attention to entrepreneurs. This essay introduces a special issue of Journal of Urban Economics dedicated to the geography of entrepreneurship. The paper frames the core questions facing researchers interested in assessing the local causes and consequences of entrepreneurship, perturbs a core urban model to incorporate entrepreneurship, and concludes by offering an agenda for future work on the spatial aspects of entrepreneurship.

Massilia norwichensis sp. nov., isolated from an air sample

A Gram-negative, rod-shaped and motile bacterial isolate, designated strain NS9T, isolated from air of the Sainsbury Centre for Visual Arts in Norwich, UK, was subjected to a polyphasic taxonomic study including phylogenetic analyses based on partial 16S rRNA, gyrB and lepA gene sequences and phenotypic characterization. The 16S rRNA gene sequence of NS9T identified Massilia haematophila CCUG 38318T, M. niastensis 5516S-1T (both 97.7% similarity), M. aerilata 5516S-11T (97.4 %) and M. tieshanensis TS3T (97.4 %) as the next closest relatives. In partial gyrB and lepA sequences, NS9T shared the highest similarities with M. haematophila CCUG 38318T (94.5 %) and M. aerilata 5516-11T (94.3 %), respectively. These sequence data demonstrate the affiliation of NS9T to the genus Massilia. The detection of the predominant ubiquinone Q-8, a polar lipid profile consisting of the major compounds diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol and a polyamine pattern containing 2- hydroxyputrescine and putrescine were in agreement with the assignment of strain NS9T to the genus Massilia. Major fatty acids were summed feature 3 (C16 : 1v7c and/or iso-C15 : 0 2-OH), C16 : 0, C18 : 1v7c and C10 : 0 3-OH. Dissimilarities in partial lepA and gyrB gene sequences as well as results from DNA–DNA hybridizations demonstrate that strain NS9T is a representative of an as-yet undescribed species of the genus Massilia that is also distinguished from its close relatives based on physiological and biochemical traits. Hence, we describe a novel species, for which we propose the name Massilia norwichensis sp. nov., with the type strain NS9T (5CCUG 65457T5LMG 28164T)

Model and experiments to determine lubricant film formation and frictional torque in aircraft landing gear pin joints

Pin joints are found in many large articulating structures. They tend to be under high load and articulate slowly; so, the joints typically operate in the boundary or mixed lubrication regimes. This means that the operating torque depends on the respective proportions of liquid and solid contact between the joint mating faces. In this article, a mixed lubrication model of a grease-lubricated landing gear joint is established to determine a theoretical Stribeck curve, frictional torque and lubricant film thickness under different loads. Parameters describing pin joint working conditions, geometry, lubricant properties and pin/bush texture are used. The model can also predict the proportion of the load that is supported by contacting asperities and lubricant film. The changing proportions of these two parts indicate transformations between different lubrication regimes. Experiments on an instrumented pin joint have been carried out to compare with the predicted friction and torque performance. Theoretical calculation results show good consistency with experimental plots at high load. But under low load, the real friction between pin and bush is significantly lower than theoretical predictions

Actinokineospora spheciospongiae sp. nov., isolated from the marine sponge Spheciospongia vagabunda

A Gram-positive staining, aerobic organism, isolated from the the Red Sea sponge Spheciospongia vagabunda was investigated for its taxonomic position. Based on 16S rRNA gene sequence analysis strain EG49T was most closely related to Actinokineospora cibodasensis and Actinokineospora baliensis (both 97.3%) and Actinokineospora diospyrosas and Actinokineospora auranticolor (both 97.0%). The 16S rRNA gene sequence similarity to all other Actinokineospora species was < 97.0 %. The quinone system of strain EG49T contains the menaqinone MK-9(H4), (47%), MK-9(H6), (27%) and MK-9(H2), (15%) in major amounts. Minor amounts of MK-7(H4), (2%), MK-9(H0), (1%), MK-9(H8) (3%) and MK-10(H4) (3%) were detected as well in addition to MK-8(H4), MK-8(H6), MK-10(H2) and MK-10(H6) (all <1%). The diagnostic diaminoacid of the peptidoglycan is meso-diaminopimelic acid. In the polar lipid profile, diphosphatidylglycerol, phosphatidylethanolamine, and hydroxyl-phosphatidylethanolamine are predominant. Phosphatidylinositol-mannoside, two unidentified phospholipids and two glycoglipids as well as one aminoglycolipid, one aminolipid and one unidentified lipid are found in addition. Fatty acid profile composed of mainly iso-branched fatty acids: iso-C16:0, iso-C14:0, iso-C15:0, and iso-C16:1 H. All these data clearly supported the allocation of the strain to the genus Actinokineospora. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain EG49T from the most closely related Actinokineospora species. Strain EG49T represents a new species of the genus Actinokineospora, for which we propose the name Actinokineospora spheciospongiae sp. nov., with strain EG49T (= DSM 45935T = CCM 8480T = LMG 27700T) as the type strain

Rubrobacter aplysinae sp. nov., isolated from the marine sponge Aplysina aerophoba

A Gram-stain-positive, non-spore-forming bacterium (strain RV113(T)) was isolated from the marine sponge Aplysina aerophoba. 16S rRNA gene sequence analysis showed that strain RV113(T) belongs to the genus Rubrobacter, and is related most closely to Rubrobacter bracarensis VF70612_S1(T) (96.9% similarity) and more distantly related (<93%) to all other species of the genus Rubrobacter. The peptidoglycan diamino acid was lysine. Strain RV113(T) exhibited a quinone system with menaquinone MK-8 as the predominant compound. The polar lipid profile of strain RV113(T) consisted of the major compounds phosphatidylglycerol and two unidentified phosphoglycolipids. The major fatty acid was anteiso-C17 : 0ω9c. These chemotaxonomic traits are in agreement with those of other species of the genus Rubrobacter. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of strain RV113(T) from all recognized Rubrobacter species. Strain RV113(T) is thus considered to represent a novel species, for which the name Rubrobacter aplysinae sp. nov. is proposed. The type strain is RV113(T) ( = DSM 27440(T) = CECT 8425(T))