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Patterns of paternity : insights into mating competition and gene flow in a recovering population of humpback whales
Get PDFFunding: British Ecological Society - SR18/1288; Carnegie Trust for the Universities of Scotland - RIG007772; Fondation d’Entreprise Total; Fonds Pacifique; Internation Fund for Animal Welfare (IFAW); Ministère de la Transition Ecologique et Solidaire; National Geographic - #NGS-50654R-18; Provinces Sud, North and Isles; Royal Society - RGF\EA\180213, RGF\R1\181014, UF160081, URF\R\221020; Royal Society of New Zealand; School of Biology Research Committee; Total Pacifique; University of St Andrews School of Biology - PhD scholarship; Vale S.A.Variation in reproductive success is a fundamental prerequisite for sexual selection to act upon a trait. Assessing such variation is crucial in understanding a species’ mating system and offers insights into population growth. Parentage analyses in cetaceans are rare, and the underlying forces of sexual selection acting on their mating behaviours remain poorly understood. Here, we combined 25 years of photo-identification and genetic data to assess patterns of male reproductive success and reproductive autonomy of the New Caledonian (Oceania, South Pacific) humpback whale breeding population. Paternity analysis of 177 mother–offspring pairs and 936 males revealed low variation in male reproductive success (average 1.17 offspring per father) relative to other polygynous species. The observed skew in success was higher than expected under random mating and skewed overall towards males (93%) without evidence of paternity over the study period. Finally, an updated male gametic mark-recapture abundance estimate of 2084 (95% confidence interval = 1761–2407, 1995–2019) fell between previous census estimates of the New Caledonian population and the wider Oceanian metapopulation. Our results provide critical insights into the mating competition of male humpback whales and population dynamics across Oceanian populations, two important factors affecting the slow recovery from whaling across the South Pacific region.Peer reviewe
Elucidation of some reactions of methyl 3-(benzyl(2-hydoxyethyl)amino)propionate using NMR
Get PDFContrary to a literature report on a close analogue, reaction of methyl 3-(benzyl(2-hydroxyethyl)amino)propionate with methanesulfonyl chloride and triethylamine gives not the expected mesylate but the corresponding chloride. Conversion of the alcohol into the corresponding bromide was achieved using carbon tetrabromide and triphenylphosphine. Fully assigned 1H and 13C NMR spectra are presented and compared for all three compounds.Peer reviewe
Seals exhibit localised avoidance of operational tidal turbines
Get PDFFunding: The monitoring platform was developed with funds from the Natural Environment Research Council (Grant Nos. NE/R015007/1 and NE/R014639/1). Software development and data analysis were funded by the Scottish Government as part of the Marine Mammal Scientific Support Program (Grant No. MMSS/002/15).1. Tidally energetic habitats are used by a range of marine mammals, including pinnipeds. These areas are also important to the tidal energy industry, leading to an overlap between tidal developments and important habitats used by seals. The concerns around negative ecological impacts from tidal turbines derive primarily from the potential for fatal collisions between animals and the moving parts of the turbine (i.e. blades) and habitat exclusion from important areas. 2. We quantified the number of encounters of seals within close range (10s of metres) of the turbine and estimated the likelihood of seal presence over an annual cycle. Data were collected with two multibeam sonars monitoring an operational turbine in the Pentland Firth, Scotland, between May 2022 and June 2023. There were 704 seal encounters within close range of the turbine. 3. We used generalised additive models (GAMs) to investigate the temporal patterns of seal presence at the turbine site. Results showed that the probability of seal presence was significantly higher at slack water, at night and during the winter months (November–January: mean of ~4 seals a day). When comparing seal presence between periods of turbine operation and non-operation, the model predicted a decrease in presence during turbine operation in flow speeds of ≥2.3 ms−1 (mean reduction of 77% at the highest flow speed; 95% CI: 22%–93%). 4. Synthesis and applications. The result showing that seals exhibit avoidance of the turbine during operation is important for industry developers and regulators, as lower numbers of seals close to the turbine reduces the potential for fatal collisions and injuries. The modelled reductions in presence can be used directly as avoidance rates in collision risk models to predict the impacts of future turbine arrays and de-risk the consenting process for this industry.Peer reviewe
Beyond the null : recognizing and reporting true negative findings
Get PDFFunding: MKS acknowledges funding from the Biotechnology and Biological Sciences Research Council (grant number: BB/X00631X/1).Science is based on ideas that might be true or false in describing reality. In order to discern between these two, scientists conduct studies that can reveal evidence for an idea, i.e., posi-tive findings, or not, i.e., negative or null findings. The outcome of these studies can either be true, i.e. reflecting the real world, or false. Much has been said about disentangling true from false positive findings and the danger of a publication bias towards positive findings. Here, we argue that publishing negative findings is important to provide an accurate picture of the real world. At the same time, we highlight that a cautious approach should be taken to minimise the impact of publishing false negative findings, which has received limited atten-tion so far. We discuss sources of false negative findings, using experimental and observa-tional animal behaviour and cognition studies as examples, which often differ from those of false positive findings. We conclude by recommending strategies for rigorous studies, such as conducting positive controls, selecting diverse samples, designing engaging protocols and clearly labelling negative findings. These practices will lead to studies that contribute to our knowledge, regardless of whether they result in positive or negative findings.Peer reviewe
Do stars still form in molecular gas within CO-dark dwarf galaxies?
Get PDFFunding: RJS gratefully acknowledges an STFC Ernest Rutherford fellowship (grant ST/N00485X/1). DJW, SCOG, NB, and RSK acknowledge funding from the European Research Council via the ERC Synergy Grant “ECOGAL” (project ID 855130). PCC acknowledges the support of a consolodated grant (ST/K00926/1) from the UK Science and Technology Funding Council (STFC).In the Milky Way and other main-sequence galaxies, stars form exclusively in molecular gas, which is traced by CO emission. However, low metallicity dwarf galaxies are often ‘CO-dark’ in the sense that CO emission is not observable even at the high resolution and sensitivities of modern observing facilities. In this work we use ultra high-resolution simulations of four low-metalicity dwarf galaxies (which resolve star formation down to the scale of star-forming cores, 0.01 pc) combined with a time-dependent treatment of the chemistry of the interstellar medium, to investigate the star formation environment in this previously hidden regime. By generating synthetic observations of our models we show that the galaxies have high to extremely high dark gas fractions (0.13 to 1.00 dependent on beam size and conditions), yet despite this form stars. However, when examined on smaller scales, we find that the stars still form in regions dominated by molecular gas, it is simply that these are far smaller than the scale of the beam (1.5″). Thus, while stars in CO-dark dwarf galaxies form in small molecular cores like larger galaxies, their cloud-scale environment is very different.Peer reviewe
A framework for assessing the habitat correlates of spatially explicit population trends
Get PDFFunding: This work was funded by The Leon Levy Foundation, The Wolf Creek Foundation, and the National Science Foundation (ABI sustaining: DBI-1939187). This work used Bridges2 at Pittsburgh Supercomputing Center and Anvil (Song et al. 2022) at the Rosen Center for Advanced Computing at Purdue University through allocation DEB200010 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services and Support (ACCESS) program, which is supported by NSF grants #2138259, #2138286, #2138307, #2137603, and #2138296.Aim: Halting widespread biodiversity loss will require detailed information on species' trends and the habitat conditions correlated with population declines. However, constraints on conventional monitoring programs and commonplace approaches for trend estimation can make it difficult to obtain such information across species' ranges. Here, we demonstrate how recent developments in machine learning and model interpretation, combined with data sources derived from participatory science, enable landscape-scale inferences on the habitat correlates of population trends across broad spatial extents. Location: Worldwide, with a case study in the western United States. Methods: We used interpretable machine learning to understand the relationships between land cover and spatially explicit bird population trends. Using a case study with three passerine birds in the western U.S. and spatially explicit trends derived from eBird data, we explore the potential impacts of simulated land cover modification while evaluating potential co-benefits among species. Results: Our analysis revealed complex, non-linear relationships between land cover variables and species' population trends as well as substantial interspecific variation in those relationships. Areas with the most positive impacts from a simulated land cover modification overlapped for two species, but these changes had little effect on the third species. Main Conclusions: This framework can help conservation practitioners identify important relationships between species trends and habitat while also highlighting areas where potential modifications to the landscape could bring the biggest benefits. The analysis is transferable to hundreds of species worldwide with spatially explicit trend estimates, allowing inference across multiple species at scales that are tractable for management to combat species declines.Peer reviewe
Tense and emotion
Get PDFArthur Prior’s (1959) ‘Thank Goodness’ argument raised the question of why we should feel relief when a bad event is over, but not when it is in the future. This was initially regarded as a challenge for the B-theory. The standard B-theory reply is that this is an example of the more general phenomenon of the essential indexical (Perry 1979). Recent scepticism about the essential indexical and the special role of the first-person perspective (Millikan 1990; Cappelen and Dever 2013; Magidor 2015) has mainly focussed on the explanation of actions. By looking closely at Prior’s example, which concerns the appropriateness of emotions, an explanation is developed in terms of a particular way of understanding the notion of egocentricity. This makes clear what is going on in Prior’s example, without recourse to a tensed metaphysics of time, and also provides a response to sceptics about the first-person perspective
The spread of finite and infinite groups
Get PDFIt is well known that every finite simple group has a generating pair. Moreover, Guralnick and Kantor proved that every finite simple group has the stronger property, known as 3/2-generation, that every nontrivial element is contained in a generating pair. More recently, this result has been generalised in three different directions, which form the basis of this survey article. First, we look at some stronger forms of -generation that the finite simple groups satisfy, which are described in terms of spread and uniform domination. Next, we discuss the recent classification of the finite 3/2-generated groups. Finally, we turn our attention to infinite groups, and we focus on the recent discovery that the finitely presented simple groups of Thompson are also 3/2-generated, as are many of their generalisations. Throughout the article we pose open questions in this area, and we highlight connections with other areas of group theory
Effect of structural disorder and inhomogeneities on the magnetic phase transitions in α-Li₂IrO₃
No full textQuantum spin liquids are crystalline materials whose ground state is defined by long-range quantum entanglement, and an excitation spectrum described by novel quasiparticles. Generating such a state requires magnetic frustration - the inability to satisfy all magnetic exchange interactions simultaneously, preventing long-range magnetic order - which can be achieved, for example, through bond-dependent exchange as for the Kitaev model. α-Li₂IrO₃ in theory satisfies the Kitaev model, but in reality has been found to have low-temperature magnetic phase transitions, signifying that it does not fully adhere to the Kitaev model. Instead, structural distortions introduce competing interactions, which result in a magnetic ground state. In this work, we outline in detail the interplay of structural disorder, off-stoichiometry, and physical properties in α-Li₂IrO₃. We combine extensive structural- and physical property characterisation to show that the sample is best described as consisting of two phases, differing by the amount of stacking faults (X-ray diffraction, TEM, mathematical modeling), and that the transition at 15 K can directly be correlated with the phase fraction of the 'unfaulted' phase, suggesting that the different phase transitions occur in different phases, and are independent. We also show that stacking faults are intimately linked to the redox behaviour of the material (study of synthesis environments, TGA, neutron diffraction), and that the magnetic transition temperatures can be suppressed (heat capacity, μSR, magnetic susceptibility) through the combination of Li-vacancies (electrochemical charging) & oxygen redox (NEXAFS). Through surface-sensitive spectroscopic techniques (XPS, AES) we highlight clear signatures of strong oxidation at the grain surface in all samples, suggesting variations in the sample properties throughout the grains. Finally, using single crystals we demonstrate that disorder alone cannot achieve the same suppression of the transition temperature (diffuse scattering, magnetic torque), but likely accounts for variations in reported physical property data
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