Can an acoustic observatory contribute to the conservation of threatened species?

Observatories are designed to collect data for a range of uses. The Australian Acoustic Observatory (A2O) was established to collect environmental sound, including audible species calls, from 344 recorders at 86 sites around Australia. We examine the potential of the A2O to monitor near threatened, threatened, endangered and critically endangered species, based on their vocal behaviour, geographic distributions in relation to the sites of the A2O and on some knowledge of habitat use. Using IUCN and EPBC lists of threatened and endangered species, we extracted species that vocalized in the audible range, and using conservative estimates of their geographic ranges, determined whether there was a possibility of hearing them at these sites. We found that it may be possible to detect up to 171 threatened species at sites established for the A2O, and that individual sites have the potential to detect up to 40 threatened species. All 86 sites occurred in locations where threatened species could possibly be detected, and the list of detectable species included birds, amphibians, and mammals. We have incidentally detected one mammal and four bird species in the data during other work. Threatening processes to which potentially detectable species were exposed included all but two IUCN threat categories. We concluded that with applications of technology to search the audio data from the A2O, it could serve as an important tool for monitoring threatened species.     

Establishment of compatibility in the Ustilago maydis/maize pathosystem

The fungus Ustilago maydis is a biotrophic pathogen parasitizing on maize. The most prominent symptoms of the disease are large tumors in which fungal proliferation and spore differentiation occur. In this study, we have analyzed early and late tumor stages by confocal microscopy. We show that fungal differentiation occurs both within plant cells as well as in cavities where huge aggregates of fungal mycelium develop. U. maydis is poorly equipped with plant CWDEs and we demonstrate by array analysis that the respective genes follow distinct expression profiles at early and late stages of tumor development. For the set of three genes coding for pectinolytic enzymes, deletion mutants were generated by gene replacement. Neither single nor triple mutants were affected in pathogenic development. Based on our studies, we consider it unlikely that U. maydis feeds on carbohydrates derived from the digestion of plant cell wall material, but uses its set of plant CWDEs for softening the cell wall structure as a prerequisite for in planta growth.     

Production and characterization of recombinant P1 adhesin essential for adhesion,gliding, and antigenic variation in the human pathogenic bacterium,Mycoplasma pneumoniae

Mycoplasma pneumoniae forms an attachment organelle at one cell pole, binds to the host cell surface, and glides via a unique mechanism. A 170-kDa protein, P1 adhesin, present on the organelle surface plays a critical role in the binding and gliding process. In this study, we obtained a recombinant P1 adhesin comprising 1476 amino acid residues, excluding the C-terminal domain of 109 amino acids that carried the transmembrane segment, that were fused to additional 17 amino acid residues carrying a hexa-histidine (6?×?His) tag using an Escherichia coli expression system. The recombinant protein showed solubility, and chirality in circular dichroism (CD). The results of analytical gel filtration, ultracentrifugation, negative-staining electron microscopy, and small-angle X-ray scattering (SAXS) showed that the recombinant protein exists in a monomeric form with a uniformly folded structure. SAXS analysis suggested the presence of a compact and ellipsoidal structure rather than random or molten globule-like conformation. Structure model based on SAXS results fitted well with the corresponding structure obtained with cryo-electron tomography from a closely related species, M. genitalium. This recombinant protein may be useful for structural and functional studies as well as for the preparation of antibodies for medical applications.     

Integration of diffraction phase microscopy and Raman imaging for label‐free morpho‐molecular assessment of live cells

Label‐free quantitative imaging is highly desirable for studying live cells by extracting pathophysiological information without perturbing cell functions. Here, we demonstrate a novel label‐free multimodal optical imaging system with the capability of providing comprehensive morphological and molecular attributes of live cells. Our morpho‐molecular microscopy (3M) system draws on the combined strength of quantitative phase microscopy (QPM) and Raman microscopy to probe the morphological features and molecular fingerprinting characteristics of each cell under observation. While the commonr‐path geometry of our QPM system allows for highly sensitive phase measurement, the Raman microscopy is equipped with dual excitation wavelengths and utilizes the same detection and dispersion system, making it a distinctive multi‐wavelength system with a small footprint. We demonstrate the applicability of the 3M system by investigating nucleated and nonnucleated cells. This integrated label‐free platform has a promising potential in preclinical research, as well as in clinical diagnosis in the near future.      

Electron microscopy of the K2 killer effect of Saccharomyces cerevisiae T206 on a mesophilic wine yeast

A mesophilic wine yeast, Saccharomyces cerevisiae CSIR Y217 K ^– R ^– was subjected to the K₂ killer effect of Saccharomyces cerevisiae T206 K ⁺ R ⁺ in a liquid grape medium. The lethal effect of the K₂ mycoviral toxin was confirmed by methylene blue staining. Scanning electron microscopy of cells from challenge experiments revealed rippled cell surfaces, accompanied by cracks and pores, while those unaffected by the toxin, as in the control experiments, showed a smooth surface. Transmission electron microscopy revealed that the toxin damaged the cell wall structure and perturbed cytoplasmic membranes to a limited extent.     

Ultrasonication of insulin-loaded microgel particles produced by internal gelation: Impact on particle's size and insulin bioactivity

Alginate-dextran sulfate (ADS) microgel has been used to protect insulin from gastrointestinal attack and as a carrier to promote insulin permeation through intestinal epithelium. The throughput of ADS submicron particles generation by emulsification/internal gelation is limited by its wide size distribution.     

Digestive activity and stomach temperature in farmed bluefin tuna Thunnus thynnus measured by acoustic tag

Eight farmed Atlantic bluefin tuna Thunnus thynnus were tagged with temperature and depth transmitters inserted in chub mackerels Scomber colias to characterize their digestive activity, feeding physiology and behaviour in captivity. Results obtained in the experiment can be used to optimize daily T. thynnus feeding strategy in farms, reducing the early regurgitation of food and thus the environmental effects of inappropriate feeding practices.     

Comparative bioacoustics: a roadmap for quantifying and comparing animal sounds across diverse taxa

Animals produce a wide array of sounds with highly variable acoustic structures. It is possible to understand the causes and consequences of this variation across taxa with phylogenetic comparative analyses. Acoustic and evolutionary analyses are rapidly increasing in sophistication such that choosing appropriate acoustic and evolutionary approaches is increasingly difficult. However, the correct choice of analysis can have profound effects on output and evolutionary inferences. Here, we identify and address some of the challenges for this growing field by providing a roadmap for quantifying and comparing sound in a phylogenetic context for researchers with a broad range of scientific backgrounds. Sound, as a continuous, multidimensional trait can be particularly challenging to measure because it can be hard to identify variables that can be compared across taxa and it is also no small feat to process and analyse the resulting high-dimensional acoustic data using approaches that are appropriate for subsequent evolutionary analysis. Additionally, terminological inconsistencies and the role of learning in the development of acoustic traits need to be considered. Phylogenetic comparative analyses also have their own sets of caveats to consider. We provide a set of recommendations for delimiting acoustic signals into discrete, comparable acoustic units. We also present a three-stage workflow for extracting relevant acoustic data, including options for multivariate analyses and dimensionality reduction that is compatible with phylogenetic comparative analysis. We then summarize available phylogenetic comparative approaches and how they have been used in comparative bioacoustics, and address the limitations of comparative analyses with behavioural data. Lastly, we recommend how to apply these methods to acoustic data across a range of study systems. In this way, we provide an integrated framework to aid in quantitative analysis of cross-taxa variation in animal sounds for comparative phylogenetic analysis. In addition, we advocate the standardization of acoustic terminology across disciplines and taxa, adoption of automated methods for acoustic feature extraction, and establishment of strong data archival practices for acoustic recordings and data analyses. Combining such practices with our proposed workflow will greatly advance the reproducibility, biological interpretation, and longevity of comparative bioacoustic studies.     

The restoration of the T-lymphoid system of nude mice: lower efficiency of nonlymphoid, epithelial thymus grafts.

The T-cell deficiency of nude mice is due to an abnormal differentiation of the thymus epithelium; it can be persistently corrected by grafting a neonatal thymus. However, grafted adult thymuses or epithelial thymuses are not repopulated by large numbers of host-derived lymphocytes, as is the case when a whole neonatal thymus is grafted. Furthermore, the repopulation of the spleen and lymph nodes by T cells is less pronounced than after whole neonatal thymus transplantation, and the restoration of the reactivity to T-cell mitogens is irregular. Therefore, the integrity and the age of the thymus graft are important for a good restoration of the T-lymphoid system of congenitally athymic animals.     

Effect of deuterium oxide on the thermodynamic quantities associated with phase transitions of phosphatidylcholine bilayer membranes

The bilayer phase transitions of three kinds of phospholipids, dipalmitoylphosphatidylcholine (DPPC), distearoylphosphatidylcholine (DSPC) and dihexadecylphosphatidylcholine (DHPC), in deuterium oxide (D₂O) and hydrogen oxide (H₂O) were observed by differential scanning calorimetry (DSC) under ambient pressure and light-transmittance measurements under high pressure. The DSC measurements showed that the substitution of H₂O by D₂O affected the pretransition temperatures and the main-transition enthalpies of all PC bilayers. The temperature-pressure phase diagrams for these PC bilayer membranes in both solvents were constructed by use of the data of light-transmittance measurements. Regarding the main transition of all PC bilayer membranes, there was no appreciable difference between the transition temperatures in D₂O and H₂O under high pressure. On the other hand, the phase transitions among the gel phases including the pretransition were significantly affected by the solvent substitution. The thermodynamic quantities of phase transitions for the PC bilayer membranes were evaluated and the differences in thermodynamic properties by the water substitution were considered from the difference of interfacial-free energy per molecule in the bilayer in both solvents. It was proved that the substitution of H₂O by D₂O causes shrinkage of the molecular area of phospholipid at bilayer interface due to the difference in bond strength between deuterium and hydrogen bonds and produces the great influence on the bilayer phase with the smaller area. Further, the induction of bilayer interdigitation in D₂O turned out to need higher pressures than in H₂O.