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Probability cueing in large-scale environmental search: The role of landmark cues in statistical learning
No full textEfficient environmental search is an important and adaptive everyday skill. A particular feature of theoretical interest is whether large-scale search is informed by the spatial statistics of the environment - probability cueing is a robust effect in two-dimensional visual search tasks, but studies of large-scale search have generated equivocal findings. Here, we examined whether sensitivity to a statistical cue specified within an allocentric reference frame is modulated by the presence and location of environmental landmarks. Participants explored fully immersive virtual environments, wherein they were presented with an array of locations (columns) and required to search them for a hidden target (i.e. the column that changed color upon activation). A target was present on each trial, appearing within the cued hemispace on 80% of trials. In Experiment 1, the array was surrounded by a featureless circular wall and participants exhibited no reliable cueing effects. Experiments 2 and 3 introduced a stable landmark into the environment and manipulated its location to be either orthogonal or adjacent to the cued hemispace. Participants reliably biased their search in response to the probability cue, although learning was only observed when the landmark was positioned along the axis orthogonal to the midline separating hemispaces. These findings suggest that adapting search behavior in response to a statistical cue is facilitated by the presence of a stable landmark when it is specified independently of the searcher’s viewpoint, although this is dependent upon the spatial relationship between the landmark and the distribution itself
Decision-making tool for onshore vs. offshore hydrogen production from offshore wind
No full textThis paper presents optimisation studies for the combination of high efficiency reversible solid oxide cells (rSOC) with offshore wind farms in the Celtic Sea. Reversible systems can be used both in electrolyser and fuel cell mode, allowing potential benefits from switching between modes depending on the instantaneous condition of the electricity and hydrogen markets. The purpose of these studies is to determine the most cost-efficient method to combine rSOC with offshore wind whilst matching electricity supply with demand. For this, a model in Python for Power System Analysis (PyPSA) is set up which optimizes production, storage and transport infrastructure for green hydrogen from electricity provided by a wind farm. Input parameters include rSOC efficiencies and infrastructure costs for the rSOC system, including the immediate balance of plant around the system, along with costs associated with hydrogen geological storage and energy transport, in the form of electricity (via subsea cable and on- and offshore substations) or hydrogen (via a subsea pipeline). Cost efficiency calculations also include the calculation of revenue from either electricity or hydrogen. A sensitivity study determines the impact of average values and daily or hourly electricity price fluctuations, as well as the impact of the price paid for hydrogen. Selection between on- and offshore hydrogen production is not predetermined but instead carried out during the optimisation calculation itself. Simulations are run for an offshore wind farm for a single year only for a large number of input parameters. The overall conclusions are that if hydrogen prices are 2.5 times higher than electricity prices, dedicated hydrogen production is recommended offshore, since the transport of hydrogen through a 60 km pipeline is cheaper than the transport of electricity through a 60 km subsea cable connection. When electricity prices are high compared to hydrogen prices, reversible hydrogen production is recommended onshore, as in this case, a subsea cable connection is required even if some hydrogen is kept as a gas
Physiological and Morphological Responses to Drought Stress in Different Cultivation Environments in Wild Type and ABA-deficient Barley
No full textGlobal food security is increasingly threatened by the effects of climate change. Of the environmental factors affected by climate change, drought is one of the most critical for plant survival and reproduction, shaping plant morphology and physiology and therefore crop productivity. Although the effects of drought on plants are widely studied, studies are often conducted in controlled greenhouse or laboratory conditions rather than more realistic field-like conditions. This is justified by the lower costs, convenience, and ability to disentangle the effects of different factors in more controlled conditions. This thesis explores the effect of the same watering limitations in different cultivation environments -greenhouse, outside container, and raised bed - on Hordeum vulgare (spring barley) growth and physiology to assess the translatability of the same applied drought treatment. Additionally, as plants in the field often experience multiple stresses simultaneously, I investigate the interaction between drought stress in spring barley and herbivory by the sap-sucking aphid herbivore Rhopalosiphum padi and the chewing mollusc herbivore Cornu aspersum. I particularly focus on the role of abscisic acid (ABA), a key phytohormone in plant-stress responses, in coordinating plant responses to these stresses in different cultivation environments through the use of the ABA-deficient spring barley mutant Az34. The results of this thesis demonstrate that the same applied drought treatment resulted in different plant growth and physiological responses in greenhouse conditions compared to simulated field conditions. Results also indicate that the effect of drought on aphid performance on barley, as well as barley response to aphid herbivory differs between cultivation environments. In controlled conditions, experiments suggested that barley may be more susceptible to both sap-sucking and chewing herbivores in drought conditions compared to control. Az34 barley did not show a consistent decrease in ABA concentration under stress conditions relative to Wild Type barley, therefore the role of ABA in responses to drought stress and herbivory were not able to be determined. Together, this thesis demonstrates the importance of studying plant-stress interactions in realistic field-like conditions in order to produce results that are more translatable to agricultural systems. Accurate assessments of how plants respond to climate change-related stresses and their interactions is becoming increasingly important for shaping effective crop management strategies and ensuring food security under future climate scenarios
Tidal Modulation of Topographic Eddies Drives Marine Megafauna Aggregations
No full textHanifaru Bay, in Baa Atoll, Maldives, is globally recognised for hosting the largest known feeding aggregations of reef manta rays (Mobula alfredi). These aggregations are spatially and temporally discrete, often associated with flood tides, and are thought to result from hydrodynamic processes that elevate zooplankton concentrations. This study investigates the role of flow-topography interactions, specifically around the small headland-like feature in the bay’s inlet (the ‘nodule’), in creating conditions conducive to these feeding events.A Delft3D hydrodynamic model of Baa Atoll was developed to simulate tidal flows within the bay, with high-resolution mesh focusing on Hanifaru Bay. Calibration and validation against in situ observations ensured the model reliably captured tidal dynamics. Results indicate that a retentive eddy forms behind the nodule during the flood tide, consistent with the timing of manta ray feeding events. This closed-core eddy retains zooplankton, allowing for their accumulation within the bay. By contrast, during the ebb tide, flow-through conditions prevent zooplankton aggregation
Scoping of Presence and Impacts of Tyre Wear Particles on Soil Systems
No full textIn recent years, concerns over environmental contamination by tyre wear particles (TWPs) have been growing. While previous studies have examined their abundance and ecotoxicological impacts in aquatic environments, research on their abundance in roadside soils—the primary sink of contamination—and their ecological effects on soil properties and terrestrial animals remains limited, calling for further investigation. In this study, Lufa 2.2 test soil and red topsoil sourced from Exeter were dosed with 0.1– 10% TWPs. Spiked soils were analysed for changes in pH, water holding capacity (WHC), and aggregate (stable cluster in soil) formation, as well as for erosion rates using a rainfall simulator. In ecotoxicological assessments, Eisenia fetida, a key species for agricultural production (Jing et al., 2023), were exposed to TWPs and examined their behaviours when contacting to the particles. Then, their bodies were investigated histologically to observe changes in seminal vesicle structures. Concentration of TWP derived elements in earthworm bodies and morphology of ingested TWPs were also examined. Additionally, soil samples were collected from farmland adjacent to highways in three different climatic regions of England to measure environmental TWP concentrations in farmland soil. The amount of TWPs could not be quantified, but TWP derived compounds (styrene, 2-methylbuta-1,3-diene, toluene, and limonene) were detected in every sample. The results of three different investigations above (TWPs’ impacts on soil properties and earthworm health, and concentration in farmland) showed increased soil pH, reduced WHC at higher concentrations, and greater aggregate formation. Earthworms displayed no avoidance behaviour but exhibited a reduction in early-stage sperm cells after short-term exposure, a decrease in growth rate after long-term exposure, and an increase in reproduction, a common response in organisms that are stressed. These findings highlight the potential for TWPs to impair both soil properties and earthworm health, and underscore the need for further work to establish ecological harmful levels
Climate Change Impacts on Forest Canopy Temperatures: from mechanisms to implications
No full textForests are a vital interface between the biosphere and the atmosphere. As global temperatures rise due to increasing anthropogenic greenhouse gas emissions, it is important to understand the response of forest tree canopy leaf temperature (Tcan). Additionally, understanding variation in Tcan and regulation across species within ecosystems is crucial for understanding how climate change affects plants. Thus, this research aimed to measure Tcan in temperate and tropical forests under contrasting environmental conditions to advance understanding of Tcan. At the Birmingham Institute of Forest Research Free-Air CO2 Enrichment (BIFoR-FACE) site, continuous thermal infrared (TIR) imaging of mature oak canopies during the 2021 – 2023 growing seasons showed that daytime Tcan consistently exceeded air temperature (Tair) by as much as 12 °C. Oaks grown under elevated CO2 (eCO2) exhibited Tcan approximately 1 °C higher than those under ambient CO2 (aCO2), driven largely by leaf structural and stomatal conductance modifications from CO2 enrichment. Although eCO2 did not directly alter leaf photosynthetic heat tolerance (PHT), a significant increase in tolerance was observed following a July 2022 heatwave, suggesting short-term acclimation of oaks to extreme heat. These findings indicate that elevated CO2 amplifies canopy–air temperature divergence (Tcan – Tair), potentially altering forest energy exchange and physiological functioning. Complementary analyses of a tropical moist semi-deciduous forest showed pronounced interspecific differences in Tcan regulation. Daily maximum Tcan frequently exceeded 40 °C, with Tcan – Tair differences up to 14 °C. These exceedances were strongly modulated by solar radiation, relative humidity, wind speed, and species-specific leaf traits. Species with higher stomatal conductance (gs) maintained cooler canopies, whereas species with lower gs experienced greater heating. Evergreen pioneers exhibited the warmest canopies, high PHTs and narrow thermal safety margins (TSMs), while deciduous and shade-tolerant species had cooler crowns, low PHTs and broader TSMs, highlighting a trade-off between tolerance-based and avoidance-based thermoregulation strategies among coexisting species. Overall, these results show that forest canopies often operate at temperatures above ambient air, that eCO2 can further intensify canopy warming, and that species differences in stomatal regulation and leaf traits underpin contrasting thermal strategies and heat risk. Thus, explicitly accounting for canopy temperature and trait-mediated thermoregulation is essential for predicting forest responses to ongoing climate change
Importance of Traditional Ecological Knowledge in Promoting Biodiversity Conservation Outside Protected Areas
No full textWe assessed traditional ecological knowledge (TEK) across different age and gender groups, focusing on selected plant species within major terrestrial ecosystems in Tanzania. A multi-stage stratified random sampling method was used to select ethnic groups, representative plant species, and participants for focus group discussions (FGDs). We conducted 24 FGDs and walk-in-the-woods exercises to verify the presence of documented species and assess their traditional uses. Additionally, we examined how TEK varied by gender and age. The data analysis included both descriptive and inferential statistics. A total of 550 plant species were validated, with some species appearing in multiple locations under different vernacular names and primary uses. Of these, 52.0% were used for food, 30.2% for medicine, 16.4% for materials, and 1.4% for ritual purposes. We observed variations in TEK across age groups, ecosystems, and use categories, with older individuals demonstrating greater knowledge in all areas. The diversity of used species generally reflects overall plant diversity, highlighting that conserving traditionally valued species can help protect broader biodiversity, especially outside protected areas (OPAN areas). Understanding the importance and scope of TEK at the ecosystem level will enhance community capacity to promote biodiversity conservation beyond protected areas and further benefit from their resources
Manta Munchies: Plankton dynamics and feeding behaviour of reef manta rays (Mobula alfredi) around D\u27Arros Island in the Seychelles
No full textThe reef manta ray (Mobula alfredi) is a threatened filter-feeding elasmobranchthat requires immediate management and protection across large parts of itsrange. Despite being well-studied, a detailed understanding of their feedingecology, which shapes their residency, movement patterns, and behaviour,remains underexplored. Both global and site-specific research is required to fillsignificant knowledge gaps essential for designing effective conservationstrategies for this species and their habitats. This study investigated M. alfredifeeding behaviour in relation to plankton biomass dynamics at D’Arros Island inthe Seychelles, the largest known M. alfredi aggregation site in the country and agazetted marine protected area. Plankton samples were collected, along withcorresponding environmental data, during M. alfredi feeding and non-feedingbehaviour. Statistical modelling revealed that surface feeding occurredpredominantly during periods of higher plankton biomass, with a critical preydensity threshold of 26.9 mg/m³, which had a significant relationship with tidalphase. Additionally, there were no significant differences in feeding behaviourand plankton biomass across seasons, which demonstrates the year-round valueof D’Arros Island to this species. These findings provide new insights into thefeeding ecology of M. alfredi in the Seychelles and support future conservationand management initiatives for this threatened species
The earliest Neolithic site in Inner Mongolia and its implications for post-Younger Dryas climate-human interactions
No full textHuman evolution during the Paleolithic-Neolithic transition n (∼15,000–10,000 years ago) has been closely linked to climate fluctuations, marked by significant societal and environmental shifts. However, the West Liao River Basin (WLRB) in eastern Inner Mongolia, North China, a key region of early East Asian civilizations, remains underexplored for this period. Situated at the modern margin of the East Asian Summer Monsoon (EASM), the WLRB offers valuable archaeological insights for understanding human responses to climate change during this pivotal phase in prehistory. Dali Lake, located in the upper reaches of the WLRB, is particularly climatically sensitive and serves as a hitherto unstudied but potentially crucial location for exploring pre-Holocene climate impacts on human development. Here, we have newly discovered an archaeological site along the shoreline of Dali Lake, named the Dali Lake site (DL site). The site contains a rich assemblage of cultural remains, including pottery shards, stone artifacts, and faunal remians. Radiocarbon dating and Bayesian modeling of bone and charcoal samples from the cultural layer indicate that human occupation at the DL site likely began between 11,753 and 11,298 cal BP, and ended between 10,502 and 10,075 cal BP, predating the earliest known Xiaohexi and Xinglongwa Neolithic cultures in the WLRB. This finding bridges the gap in archaeological evidence from this transition period and establishes the DL site as both the earliest Neolithic site and the earliest pottery site in Inner Mongolia so far. Additionally, the DL site is positioned at one of the highest recorded lake-level highstands suggesting that human activity may have been influenced by, or even adapted to, fluctuating lake levels driven by climatic changes over time. The discovery of the DL site has significant implications for understanding the interactions between human development and climate warming, as evidenced by high lake levels in Inner Mongolia following the Younger Dryas (YD) cold period (∼12,900–11,600 cal BP)
Momentary assessment of mental imagery and pain-related psychological factors in youth with chronic pain
No full textMental imagery is a powerful cognitive process implicated in various psychological disorders, yet its role in chronic pain remains underexplored. This study examined the temporal relationship between mental imagery, pain-related psychological constructs, and pain outcomes in young adults with chronic pain. A sample of 121 university students with chronic pain completed baseline assessments of mental imagery (tendency, ability, intrusive imagery), pain-related psychological constructs (interpretation bias, fear of progression, pain anxiety), and general psychological constructs (depression, anxiety, stress, emotion regulation difficulties, trauma symptoms). Participants then completed an ecological momentary assessment delivered by smartphone app 3 times daily for 1 week, reporting on pain severity, pain interference, pain-related imagery (frequency, valence, vividness), and pain expectancy. Multilevel and cross-lagged models were used to assess within- and between-person predictors of pain outcomes. We found that pain-specific imagery, particularly intrusive imagery at baseline and momentary imagery frequency, was consistently associated with greater pain severity and interference, and predicted subsequent pain severity. General imagery tendency was inversely associated with pain outcomes, suggesting a potential protective effect. Increased pain imagery valence and vividness were differentially associated with increased pain severity and interference, respectively. Pain expectancy, interpretation bias, and fear of progression were also significant predictors of pain interference, while pain expectancy also predicted subsequent pain severity. These findings suggest that pain-specific mental imagery is a temporally relevant and potentially modifiable predictor of pain outcomes in young adults