Investigating the links between behavioural types and mate choice in a polygynous pinniped

Consistent individual differences in behaviour (CIDs) or behavioural types have now been shown in a broad range of taxa, from Cnidarians to birds and mammals. An individual’s behavioural type can influence may aspects of its life history including foraging strategies and mate choice decisions. Grey seals (Halichoerus grypus) have been shown to exhibit behavioural types ranging from proactive to reactive but the implications of this on sexual behaviour and mate choice decisions have not yet been investigated. This study tests the prediction that females with a more reactive personality type should be more choosy in their mate choice decisions. Behavioural observations were made at two distinct sites within Donna Nook breeding colony on the Lincolnshire coast, UK. The RAF site was characterised by flat topography and very low human presence while the public site was more topographically varied and had a high level of human presence. The behavioural types of females were determined by examining the rate at which they performed pup-checking behaviour in both disturbed and undisturbed situations. Females were considered to have a more proactive behavioural type if they maintained a relatively constant rate of pup-checking across situations and a more reactive behavioural type if their rate of pup-checking changed across situations. Owing to their tendency to be found on the edges of the colony where they are subject to increased harassment by transient males it was predicted that females with a more reactive behavioural type would show frequent and intense aggression towards males. In contrast, due their tendency to occupy the best pupping sites at the centre of the colony which are occupied by more dominant males it was predicted that females with a more proactive behavioural type would show fewer and less intense aggressive interactions towards males. This pattern would indicate female mate choice by showing that females respond more aggressively to low ranking transient males than they do to more dominant males suggesting a preference for the latter. Detailed accounts of all aggressive interactions involving focal females were recorded ad-lib in the field. In agreement with previous studies, evidence of CIDs in the pup-check rates of females in undisturbed situations was identified at this colony. However, in contrast with past research no evidence of CIDs in disturbed situations was found. A significant difference was found in the mean pup-check rates of females at the two study sites with females at the less disturbed RAF site pup-checking at a significantly greater rate. The data also showed significant differences in rates and intensities of aggression between the two study sites with females at the RAF site showing a higher rate but lower intensity of aggression than those at the public site. However, no evidence was found to support the hypothesis that reactive females show higher level of aggression towards males than do proactive females. Thus, no evidence of female mate choice in grey seals was found in this study. Despite this, potentially interesting effects of topography and/or anthropogenic presence on grey seal behaviour were found and these may prove to be interesting avenues for future research

Repeatability and degree of territorial aggression differs among urban and rural great tits (<i>Parus major</i>)

Animals in urban habitats face many novel selection pressures such as increased human population densities and human disturbance. This is predicted to favour bolder and more aggressive individuals together with greater flexibility in behaviour. Previous work has focussed primarily on studying these traits in captive birds and has shown increased aggression and reduced consistency between traits (behavioural syndromes) in birds from urban populations. However, personality (consistency within a behavioural trait) has not been well studied in the wild. Here we tested whether urban free-living male great tits show greater territorial aggression than rural counterparts. We also tested predictions that both behavioural syndromes and personality would show lower consistency in urban populations. We found that urban populations were more aggressive than rural populations and urban birds appeared to show lower levels of individual behavioural repeatability (personality) as predicted. However, we found no effect of urbanisation on behavioural syndromes (correlations between multiple behavioural traits). Our results indicate that urban environments may favour individuals which exhibit increased territorial aggression and greater within-trait flexibility which may be essential to success in holding urban territories. Determining how urban environments impact key fitness traits will be important in predicting how animals cope with ongoing urbanisationpublishersversionPeer reviewe

Acute carpal tunnel syndrome: early nerve decompression and surgical stabilization for bony wrist trauma

Background We undertook this study to investigate the outcomes of surgical treatment for acute carpal tunnel syndrome following our protocol for concurrent nerve decompression and skeletal stabilization for bony wrist trauma to be undertaken within 48-hours. Methods We identified all patients treated at our trauma centre following this protocol between 1 January 2014 and 31 December 2019. All patients were clinically reviewed at least 12 months following surgery and assessed using the Brief Michigan Hand Outcomes Questionnaire (bMHQ), the Boston Carpal Tunnel Questionnaire (BCTQ) and sensory assessment with Semmes-Weinstein monofilament testing. Results The study group was made up of 35 patients. Thirty-three patients were treated within 36-hours. Patients treated with our unit protocol for early surgery comprising nerve decompression and bony stabilization within 36-hours, report excellent outcomes at medium term follow up. Conclusions We propose that nerve decompression and bony surgical stabilization should be undertaken as soon as practically possible once the diagnosis is made. This is emergent treatment to protect and preserve nerve function. In our experience, the vast majority of patients were treated within 24-hours however where a short period of observation was required excellent results were generally achieved where treatment was completed within 36-hours

Lombard effect onset times reveal the speed of vocal plasticity in a songbird

Animals that use vocal signals to communicate often compensate for interference and masking from background noise by raising the amplitude of their vocalisations. This response has been termed the Lombard effect. However, despite more than a century of research, little is known how quickly animals can adjust the amplitude of their vocalisations after the onset of noise. The ability to respond quickly to increases in noise levels would allow animals to avoid signal masking and ensure their calls continue to be heard, even if they are interrupted by sudden bursts of high-amplitude noise. We tested how quickly singing male canaries (Serinus canaria) exhibit the Lombard effect by exposing them to short playbacks of white noise and measuring the speed of their responses. We show that canaries exhibit the Lombard effect in as little as 300 ms after the onset of noise and are also able to increase the amplitude of their songs mid-song and mid-phrase without pausing. Our results demonstrate high vocal plasticity in this species and suggest that birds are able to adjust the amplitude of their vocalisations very rapidly to ensure they can still be heard even during sudden changes in background noise levels

Readout-delay-free Bragg atom interferometry using overlapped spatial fringes

A method for mitigating the readout delay characteristic of Bragg-based atom interferometry is presented, utilizing an asymmetric Mach-Zehnder interferometer sequence to generate spatial fringes that are read out while still overlapped. The time of flight after the final beamsplitter is engineered to facilitate constructive overlap of the fringes on the output states. A noise analysis performed using a precision atom interferometer is presented, comparing the traditional separated symmetric scheme with that of the separated and overlapped asymmetric scheme showing no significant increase in short-term phase noise

Tunable narrow-linewidth laser at 2 µm wavelength for gravitational wave detector research

We present and characterize a narrow-linewidth external-cavity diode laser at 2 μm, and show that it represents a low-cost, high-performance alternative to fiber lasers for research into 2 μm photonic technologies for next-generation gravitational-wave detectors. A linewidth of 20 kHz for a 10 ms integration time was measured without any active stabilization, with frequency noise of ∼ 15 Hz/√Hz between 3 kHz and 100 kHz. This performance is suitable for the generation of quantum squeezed light, and we measure intensity noise comparable to that of master oscillators used in current gravitational wave interferometers. The laser wavelength is tunable over a 120 nm range, and both the frequency and intensity can be modulated at up to 10 MHz by modulating the diode current. These features also make it suitable for other emerging applications in the 2 μm wavelength region including gas sensing, optical communications and LIDAR.Australian Research Council (CE170100004

Genotoxicity of metal oxide nanomaterials: review of recent data and discussion of possible mechanisms

Nanotechnology has rapidly entered into human society, revolutionized many areas, including technology, medicine and cosmetics. This progress is due to the many valuable and unique properties that nanomaterials possess. In turn, these properties might become an issue of concern when considering potentially uncontrolled release to the environment. The rapid development of new nanomaterials thus raises questions about their impact on the environment and human health. This review focuses on the potential of nanomaterials to cause genotoxicity and summarizes recent genotoxicity studies on metal oxide/silica nanomaterials. Though the number of genotoxicity studies on metal oxide/silica nanomaterials is still limited, this endpoint has recently received more attention for nanomaterials, and the number of related publications has increased. An analysis of these peer reviewed publications over nearly two decades shows that the test most employed to evaluate the genotoxicity of these nanomaterials is the comet assay, followed by micronucleus, Ames and chromosome aberration tests. Based on the data studied, we concluded that in the majority of the publications analysed in this review, the metal oxide (or silica) nanoparticles of the same core chemical composition did not show different genotoxicity study calls (i.e. positive or negative) in the same test, although some results are inconsistent and need to be confirmed by additional experiments. Where the results are conflicting, it may be due to the following reasons: (1) variation in size of the nanoparticles; (2) variations in size distribution; (3) various purities of nanomaterials; (4) variation in surface areas for nanomaterials with the same average size; (5) differences in coatings; (6) differences in crystal structures of the same types of nanomaterials; (7) differences in size of aggregates in solution/media; (8) differences in assays; (9) different concentrations of nanomaterials in assay tests. Indeed, due to the observed inconsistencies in the recent literature and the lack of adherence to appropriate, standardized test methods, reliable genotoxicity assessment of nanomaterials is still challenging

Recent Progress in Electrospun Nanofibres: Reinforcement Effect and Mechanical Performance

Composite materials are becoming increasingly important as structural materials for aeronautical and space engineering, naval, automotive, and civil engineering, sporting goods, and other consumer products. Fiber-based reinforcement represents one of the most effective manufacturing strategies for enhancing the mechanical strength and other properties of composite materials. Electrospinning has gained widespread interest in the last two decades because of its ability to fabricate continuous ultrafine nanofibers with unique characteristics. The impact of electrospinning on fiber synthesis and processing, characterization, and applications in drug delivery, nanofiltration, tissue scaffolding, and electronics has been extensively studied in the past. In this article, the authors have focused on a comprehensive review of the mechanical performance and properties of electrospun nanofibers as potential reinforcements as well as their advanced nanocomposites

High-performance liquid chromatography–tandem mass spectrometry in the identification and determination of phase I and phase II drug metabolites

Applications of tandem mass spectrometry (MS/MS) techniques coupled with high-performance liquid chromatography (HPLC) in the identification and determination of phase I and phase II drug metabolites are reviewed with an emphasis on recent papers published predominantly within the last 6 years (2002–2007) reporting the employment of atmospheric pressure ionization techniques as the most promising approach for a sensitive detection, positive identification and quantitation of metabolites in complex biological matrices. This review is devoted to in vitro and in vivo drug biotransformation in humans and animals. The first step preceding an HPLC-MS bioanalysis consists in the choice of suitable sample preparation procedures (biomatrix sampling, homogenization, internal standard addition, deproteination, centrifugation, extraction). The subsequent step is the right optimization of chromatographic conditions providing the required separation selectivity, analysis time and also good compatibility with the MS detection. This is usually not accessible without the employment of the parent drug and synthesized or isolated chemical standards of expected phase I and sometimes also phase II metabolites. The incorporation of additional detectors (photodiode-array UV, fluorescence, polarimetric and others) between the HPLC and MS instruments can result in valuable analytical information supplementing MS results. The relation among the structural changes caused by metabolic reactions and corresponding shifts in the retention behavior in reversed-phase systems is discussed as supporting information for identification of the metabolite. The first and basic step in the interpretation of mass spectra is always the molecular weight (MW) determination based on the presence of protonated molecules [M+H]+ and sometimes adducts with ammonium or alkali-metal ions, observed in the positive-ion full-scan mass spectra. The MW determination can be confirmed by the [M-H]- ion for metabolites providing a signal in negative-ion mass spectra. MS/MS is a worthy tool for further structural characterization because of the occurrence of characteristic fragment ions, either MSn analysis for studying the fragmentation patterns using trap-based analyzers or high mass accuracy measurements for elemental composition determination using time of flight based or Fourier transform mass analyzers. The correlation between typical functional groups found in phase I and phase II drug metabolites and corresponding neutral losses is generalized and illustrated for selected examples. The choice of a suitable ionization technique and polarity mode in relation to the metabolite structure is discussed as well