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Salinity does not affect late-stage in-egg embryonic or immediate post-hatch development in an ecologically important land crab species
Full text linkEnvironmental drivers such as salinity can impact the timing and duration of developmental events in aquatic early life stages of crustaceans, including terrestrial crabs of the family Gecarcinidae. Low salinity delays larval development in land crabs, but nothing is known about its influence on the crucial late-stage encapsulated embryonic or immediate post-hatch development. Therefore, we exposed fertilised late-stage embryos of the Christmas Island red crab (Gecarcoidea natalis) to differing salinities (100%, 75%, 50% or 25% sea water) for 24 h during their spawning period and measured some key developmental and physiological traits. We found no effect of salinity on time of first heartbeat, time of hatching, first in-egg embryonic and post-hatch heart rate, or post-hatch activity duration. These results highlight the importance of considering all early life stages when fully characterising the effects of environmental drivers on crustacean development, including under climate change
Apparent statistical inference in crows may reflect simple reinforcement learning
Full text linkJohnston et al. report results which they argue demonstrate that crows engage in statistical inference during decision-making. They trained two crows to associate a set of stimuli with different reward probabilities (from 10% to 90%) before choice tests between pairs of stimuli. Across most pairwise combinations, and in a control task in which the number of rewards was equated between probabilities, both crows preferred the stimulus associated with higher reward probability. The magnitude of this preference was affected by the absolute difference between the two probabilities, although (contrary to a claim made by Johnston et al. 2023) preference did not reflect the ratio of prior probabilities independently of absolute differences. Johnston et al. argue that preference for the stimulus with the higher reward probability is “the signature of true statistical inference” (p. 3238), implemented by an analogue magnitude system that represents the reward probability associated with each stimulus. Here, we show that a simple reinforcement learning model, with no explicit representation of reward probabilities, reproduces the critical features of crows’ performance—and indeed better accounts for the observed empirical findings than the concept of statistical inference based on analogue magnitude representations, because it correctly predicts the absence of a ratio effect that would reflect magnitudes when absolute distance is controlled. Contrary to Johnston et al.’s claims, these patterns of behaviour do not necessitate retrieval of calculated reward probabilities from long-term memory and dynamic application of this information across contexts, or (more specifically) require the involvement of an analogue magnitude system in representing abstract probabilities
The Transformative Potential Of Design Thinking In Learning Development
Full text linkThis opinion piece argues that Design Thinking (DT) can facilitate a more empathetic and student-centred approach to service development and problem-solving in Learning Development (LD). While DT is already established within higher education, we argue it is still underutilised, especially in the context of LD. We start by unpacking the methodologies, tools, and practices that are brought together under the umbrella of DT and address the tensions inherent in adapting processes that have evolved largely out of business. We argue that by bringing the learner-centred values of Learning Development (LD) to the practices of DT, there is ample scope to embrace the creativity, innovation, and collaboration inherent in DT and to develop new LD practices that have the potential to involve learners more fundamentally in developing both our services and the scholarship of LD. It is in this context that DT can have a transformative impact on the practice of LD
Crni Srbi and Ron Holsey
Full text linkIn this essay, YouTube music videos operate as one of those grey areasbetween the closely policed borders of the Greater Europe described above: a space where Black and Serbian hip-hop artists collaborate in narratives that suggest a transnational and transracial workingman’s solidarity, against contemporary Serbian assumptions of ethnic primacy and assertions of European ‘whiteness’. For the past quarter century, Eastern Europe has been seen in terms of Edward Said’s Orientalism, with its imaginative geography and nesting alteritisms; Baker invites us to look through the lens of Paul Gilroy’s Black Atlantic and to see instead lived geopolitical experience andperipheral solidarities
The Former Pelagic Longline Fishery of a Large‐Scale Marine Protected Area
Full text linkThe establishment of large-scale marine protected areas (LSMPAs) has emerged as one of the defining trends in ocean conservation over recent decades. To assess the potential benefits of such designations, it is necessary to understand the nature of the threats that have been excluded. Here, we summarise over 25 years of historical catch and effort data for a pelagic longline fishery that formerly operated within the recently designated LSMPA surrounding Ascension Island (UK), using data compiled from logbooks and observer programmes. Licenced fishing by foreign vessels (primarily flagged to Taiwan and Japan) operated intermittently in the Ascension Island exclusive economic zone (EEZ) between 1988 and 2016, with catch peaking at over 5000 t year−1 in the early 1990s. Bigeye tuna (Thunnus obesus) was the dominant species targeted (76% of total catch weight) whilst oceanic sharks (e.g. blue shark Prionace glauca) and other predatory pelagic finfish (e.g. longnose lancetfish Alepisaurus ferox) appear to have presented a sizable bycatch risk, accounting for 37% of total individuals caught in local observer data. The fishery displayed strong seasonality, with two thirds of activity occurring between December and March and was consistently concentrated in the northwest of the EEZ. This distribution closely aligns with recent satellite-derived vessel tracking data which suggests that a regional longline fishing hotspot remains in the high seas area adjacent to the northwest of the Ascension Island MPA. Our results suggest that predatory pelagic fish and sharks will be the most direct beneficiaries of the Ascension Island MPA, although the high mobility of these species may lessen any conservation impacts, given intense the fishing effort in adjacent high seas areas. While illegal fishing remains a potential threat, the spatiotemporal predictability of the historic fishery may be useful in identifying areas of elevated risk for targeted enforcement in this large, remote MPA
Neural Adaptive Nonlinear MIMO Control for Bipedal Walking Robot Locomotion in Hazardous and Complex Task Applications
Full text linkThis paper introduces a robust neural adaptive MIMO control strategy to improve the stability and adaptability of bipedal locomotion amid uncertainties and external disturbances. The control combines nonlinear dynamic inversion, finite-time convergence, and radial basis function (RBF) neural networks for fast, accurate trajectory tracking. The main novelty of the presented control strategy lies in unifying instantaneous feedback, real-time learning, and dynamic adaptation within a multivariable feedback framework, delivering superior robustness, precision, and real-time performance under extreme conditions. The control scheme is implemented on a 5-DOF underactuated RABBIT robot using a dSPACE DS1103 platform with a sampling rate of ∆t=1.5 ms (667 Hz). The experimental results show excellent performance with the following: The robot achieved stable cyclic gaits while keeping the tracking error within e=±0.04 rad under nominal conditions. Under severe uncertainties of trunk mass variations ∆mtrunk=+100%, limb inertia changes ∆Ilimb=±30%, and actuator torque saturation at τ=±150 Nm, the robot maintains stable limit cycles with smooth control. The performance of the proposed controller is compared with classical nonlinear decoupling, non-adaptive finite-time, neural-fuzzy learning, and deep learning controls. The results demonstrate that the proposed method outperforms the four benchmark strategies, achieving the lowest errors and fastest convergence with the following: IAE=1.36, ITAE=2.43, ISE=0.68, tss=1.24 s, and Mp=2.21%. These results demonstrate evidence of high stability, rapid convergence, and robustness to disturbances and foot-slip
Spatial and temporal heterogeneity of the marine nitrogen cycle during the end-Triassic mass extinction
Full text linkThe end-Triassic mass extinction (ETME) marks a pivotal event in Earth's history, characterized by major environmental changes in both marine and terrestrial settings and significant perturbations in the carbon and nitrogen biogeochemical cycles alongside extinction events. Here we employ high-resolution organic carbon isotopes (δ13Corg), nitrogen isotopes from bulk samples (δ15Nbulk), total organic carbon (TOC) and nitrogen content (TN), complemented by carbon (δ13Ckerogen) and nitrogen isotopes (δ15Nkerogen) of kerogen extracts from the Kuhjoch section in Austria in order to investigate the interplay between marine redox state, nitrogen cycling, and the biotic crisis across the Triassic–Jurassic boundary. Our results reveal a significant positive shift (∼3 ‰) in δ15Nbulk values, indicating a perturbed marine nitrogen cycle and expansion of the oxygen minimum zone prior to the ETME. The δ15N profiles suggest a transition from a nitrate-limited ocean dominated by nitrogen fixation to a post-extinction ocean with increased proportion of assimilation of NO3− undergoing non-quantitative denitrification. We also examine the spatial and temporal heterogeneity of the marine nitrogen cycle from different paleoenvironmental settings across the Triassic–Jurassic transition. Bioavailable nitrogen (NO3− and NH4+) limitation prevailed at some localities before and during the ETME. However, the development of N limitation was not synchronous across different locations: it emerged before the ETME in some European basins and intensified after the ETME on Panthalassan shelves. The early Hettangian saw an expansion of euxinic waters into the photic zone and shoaling of the chemocline. Enhanced continental weathering and deep-water upwelling increased nutrient supply, thereby alleviating N limitation. Our new observations point to an unstable and stratified marine environment during the Triassic–Jurassic transition, and suggest that nitrogen bioavailability and redox conditions may be key factors for the devastation of marine ecosystems
Complex breathlessness intervention in idiopathic pulmonary fibrosis (BREEZE-IPF): a feasibility, wait-list design randomised controlled trial
Full text linkIntroduction Breathlessness is common and impairs the quality of life of people with idiopathic pulmonary fibrosis (IPF) and non-IPF fibrotic interstitial lung diseases (ILD). We report the findings of a multicentre, fast-track (wait-list), mixed-methods, randomised controlled, feasibility study of a complex breathlessness intervention in breathless IPF and non-IPF fibrotic ILD patients. Methods Breathless IPF and non-IPF fibrotic ILD patients were randomised to receive the intervention within 1 week (fast-track) or after 8 weeks (wait-list). The intervention comprised two face-to-face and one telephone appointment during a 3-week period covering breathing control, handheld fan-use, pacing and breathlessness management techniques, and techniques to manage anxiety. Feasibility and clinical outcomes were assessed to inform progression to, and optimal design for, a definitive trial. A qualitative substudy explored barriers and facilitators to trial and intervention delivery. Results 47 patients (M:F 38:9, mean (SD) age 73.9 (7.2)) were randomised with a recruitment rate of 2.5 participants per month across three sites. The adjusted mean differences (95% CI) for key clinical outcomes at 4 weeks post randomisation were as follows: Chronic Respiratory Questionnaire breathlessness mastery domain (0.45 (-0.07, 0.97)); and numerical rating scales for 'worst' (-0.93 (-1.95, 0.10)), 'best' (-0.19 (-1.38, 1.00)), 'distress caused by' (-1.84 (-3.29, -0.39)) and 'ability to cope with' (0.71 (-0.57, 1.99)) breathlessness within the past 24 hours. The qualitative substudy confirmed intervention acceptability and informed feasibility and acceptability of study outcome measures. Conclusion A definitive trial of a complex breathlessness intervention in patients with IPF and non-IPF fibrotic ILD is feasible with preliminary data supporting intervention effectiveness
Technoeconomic assessment of floating offshore wind technology in South Africa.
Full text linkExpanding floating offshore wind into emerging and future markets could support emission reduction targets and promote energy security in several national contexts. This implies the need for adequate and systematic assessments to fully comprehend the potential of the major floater typologies (semisubmersible, spar, and tension-leg platform) in these markets. South Africa is a prime case study due to its huge technical potential for floating offshore wind and the ongoing energy crisis in the country. The Government of South Africa also intends to decarbonise its energy sector which is largely powered by coal fired power plants.This thesis assessed the technoeconomic feasibility of floating offshore wind technology through a multidisciplinary approach that estimated the locational potential of the technology after exclusion of non-feasible sites; selected the optimum sites for deployments using a combined Analytical Hierarchy Process and Geographic Information System methodology; carried out technoeconomic analysis using windPRO, WAsP, and a floating wind cost model developed to understand the economic implications of developing the technology; and conducted sensitivity analysis to establish the most important contextual cost components.This research found that 2% (246,105.4 km 2) of South Africa’s entire Exclusive Economic Zone (EEZ) is appropriate for hosting floating wind turbines, with a potential to generate a maximum of 142.61 GW of floating wind power. Although the Western Cape (WC) province holds the highest potential (80.52 GW) for floating wind in the country, the Eastern Cape (EC) region, with a locational potential of 20.04 GW, is considered most suitable for early-stage developments due to having the highest availability of grid connection capacity, limited marine traffic, and proximity to appropriate port facilities.The relative priorities for floating wind site selection, as judged by the experts, includes wind speed (27.69%), distance to port (14.10%), water depth (13.95%), distance from grid (12.95%), distance from shore (9.28%), distance from cables and pipelines (8.95%), shipping density (7.69%), distance from airports (3.34%), and distance from oil and gas deposits (2.05%). By integrating these results in a GIS environment, 25 sites in the Northern Cape (NC), WC, EC, and Kwazulu Natal (KN) regions of the country, which can hold a total of over 71 GW of floating wind capacity, were selected.Technoeconomic analysis produced LCOE values ranging from £161.1/MWh (3250.88 ZAR/MWh) for tension-leg platform to £190.33/MWh (3841.06 ZAR/MWh) for semisubmersible, and NPV figures varying from -£194.44M for TLP to -£336.9M for semisubmersible. LCOE sensitivity analysis revealed that exchange rate, discount rate, capacity factor, project lifetime, and water depth had the greatest lowering effect on LCOE, respectively, while the NPV sensitivity analysis discovered that a 33.2% increase in cost of electricity could yield positive NPV values ranging from £3.65M to £33.32M. To achieve this potential, industry actors and policymakers must prioritise selected sites in the context of the characteristics that would influence the technoeconomic feasibility of future floating wind projects in South Africa
Written in Stone: a poetic exploration of our enduring relationship with rocks, and how they ignite creativity.
Full text linkThis PhD explores humankind’s long relationship with rock and the effects it can have on our creativity and affinity with the natural world. Using rock as a conduit for a sense of appreciation and belonging, could a pebble in the hand spark an inherent need in us to understand our place in deep time and appreciate the moment? Can we take inspiration from the works of writers and artists such as Jeffrey Cohen, Hugh MacDiarmid and Barbara Hepworth to try to understand the almost otherworldly attributes that rocks may possess?This exegesis will show how, far from being inert or merely functional, stones have often been regarded as objects of reflection and wonder and can connect us with something akin to the Dreaming of the Aboriginal People and Torres Strait Islander cultures; an everywhen in which our imagination can run; free of scientific absolutes, conventional limitations and (sometimes) physical restrictions. This, in turn, can become an important aid in sparking creativity.Drawing on my research, l created a self-illustrated collection of poetry, mainly composed en plein air at sites along the East and North Yorkshire coasts and further edited and refined after a short period of recollection. Focussing largely on the geology and nature of these areas, including the problems they have faced (and are still facing) from human intervention, they range from descriptive to surreal, contrasting close observation with mystical flights of imagination.Several of the poems were written during the unsettling times of the Covid 19 pandemic. The collection, along with my research, also explores themes of overcoming writers’ block as a result of worries during lockdown, as well as the heightened sense of appreciation that regaining a freedom to reconnect with the natural world brings