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Late Quaternary palaeoenvironmental reconstruction of northern Namibia using palaeolake sediments from Etosha Pan
Get PDFPalaeoenvironmental reconstructions are an important tool in understanding major environmental and climatic changes from the past and into the future. They are critical in parts of southwestern Africa where existing records are sparse and future rates of climate change are predicted to be high. Etosha Pan is situated in the drylands of northern Namibia and has long attracted the interest of researchers who hypothesised changes in its geomorphological and palaeoenvironmental context over the late Quaternary. One of the reasons for uncertainty about the basin’s palaeohydrological history is the lack of precision in age control to uncover the history of the pan over past millennia. In this thesis, a dual approach of optically stimulated luminescence (OSL) and radiocarbon dating of lakebed sediments and marginal sand ridges was adopted to better constrain the timing of major palaeoenvironmental changes. The work was undertaken by extracting samples from the north-western part of the pan and subjecting them to a range of sedimentological and geochemical analyses. The new data from this study were used to reconstruct palaeoenvironmental and palaeohydrological dynamics in the Etosha basin from the last 40 ka. Key findings are that the pan underwent fluctuating lake levels in response to changing climate. This study proposes that, during the last glacial maximum (LGM, 23 - 19 ka), Etosha Pan sustained a deep lake under a wetter climate. The pan later experienced shallow lake levels at the start of the Holocene, which increased again due to a more humid climate during the mid-Holocene (7 - 5 ka). The key source of moisture during both periods is likely summer rainfall due to a temporary southward migration of the African tropical rain belt. These findings have implications for palaeoclimate modelling exercises for the LGM and mid-Holocene periods and assist in clarifying conflicting hypotheses of pan geomorphological evolution
Thinking what we want: a moral right to acquire control over our thoughts
No full textOur ability to exert control over our thoughts is limited. Thoughts come into our awareness without our choosing or willing that they do. We are also often unable to change the content of our thoughts by force of will alone. Emerging psychological techniques and neurotechnologies may allow us to acquire greater control over our thoughts. This chapter examines whether we have a moral right to acquire such control. We suggest that people have a strong and deeply personal interest in having control over their own thoughts and argue that this interest plausibly grounds such a moral right. However, we also argue that this moral right is limited in scope; it does not extend to all cases in which the right-holder seeks to acquire mental control that they will exercise in duty-infringing ways
Networked collective dynamics in animal ecology and cell biology
No full textCollective behavior, emerging from interactions among individuals, is a ubiquitous phenomenon observed across a wide range of biological systems—from cellular dynamics to animal ecology. Network science offers powerful tools for understanding the structure and functional properties underlying such systems. Despite significant progress in modeling, data-driven analysis, and interdisciplinary approaches, several critical challenges persist. How do complex social interactions among individuals influence the emergence of collective behavior? Moreover, in what ways do individual information and social interactions jointly shape collective decision-making? To address these challenges, this review synthesizes recent advances in network science, statistical physics, and artificial intelligence as applied to the study of collective phenomena. We focus on collective patterns in animals and cells, highlighting the interplay between structure and dynamics. The review begins with an overview of basic forms of collective behavior, followed by discussions of microscopic and macroscopic modeling approaches, structural and functional features of social interaction networks, mechanisms of information transmission, decision-making processes, and emergent collective intelligence. We also explore cutting-edge applications, including bio-inspired robotic swarms and coordination systems for unmanned aerial vehicles. We conclude by outlining open questions and potential research directions, aiming to provide insights into the design, control, and understanding of complex collective systems across biology, physics, and artificial intelligence
Learning the Manchu writing system: the role of intra-symbol processing in orthography acquisition
No full textCharacteristics of the Manchu writing system provide an excellent testing ground for current theorizing about orthography acquisition. Using traditionally demarcated orthographic units called uju hergen—symbol blocks representing phonological syllables—we investigated the role of visual features and phonological representations in learning the Manchu symbol set. Novice Manchu learners (n = 196; 89.8% female; Mage = 18.79) participated in two experiments. Experiment 1 focused on visual complexity effects and Experiment 2 on mapping complexity effects and switching costs. Among visual characteristics, the number of connected points was found to make a unique contribution to uju hergen recognition. Naming error rate was lower for a list of uju hergen with single (one-to-one) mapping between a phoneme marker and sound compared to a matched list but with multiple (one-to-many) mapping. No switching cost was observed between lists with low- and high-switching-demand. Established explanatory constructs of grain size, orthographic depth and orthographic breadth, referenced together as the construct of orthographic scale, explain the results. But reading uju symbol blocks also requires processing within symbol blocks: at the visual level, connected points provide the sub-symbol cues to decompose discrete simple features and recompose them into phoneme markers; and at the level of phonological representation, the resultant markers must be read by appropriate symbol-to-sound mapping. Together, our study expands theorising on orthography acquisition by bringing focus on the under-studied construct of intra-symbol processing
Contextual Bohmian Quantum Field Theories: A Hylomorphic Approach to QFT
No full textWe propose an extension of Bell-type Bohmian quantum field theories, called Contextual Bohmian Quantum Field Theory (CBQFT), which integrates micro-level dynamics and macro-level contextual structure within a unified, ontologically explicit formalism. CBQFT introduces classical variables that encode macroscopic contexts—such as detector configurations, thermal phases, or symmetry-breaking sectors—and allows these to modulate the underlying quantum dynamics in a lawlike way. We develop two versions of the model. CBQFT-1 treats context as a fixed but dynamically influential background, entering via a context-sensitive Hamiltonian and modified Bell-type jump rates on a single Fock space. CBQFT-2 upgrades context to a dynamical variable co-evolving with the particle (or field) configuration: selects a (typically inequivalent) representation of the field algebra on a Hilbert space, wavefunctions are realised as global sections of the resulting Hilbert bundle, and Bohmian trajectories are guided by globally well-defined velocity fields constructed from local currents. Context transitions in CBQFT-2 are governed by a stochastic kernel informed by particle (or field) configurations and histories. This yields a Bohmian QFT with an explicit feedback loop between quantum events and macroscopic structure, offering a hylomorphic account of measurement, decoherence, and top–down causation
The effect of ambient and injection pressure on droplet size of ammonia sprays in a constant volume chamber
No full textAmmonia, a zero carbon energy vector, is under consideration for decarbonising marine and energy storage applications due to its high mass-based energy density compared to many alternatives. In addition, there is widespread existing supply and transportation infrastructure due to ammonia’s use as a fertiliser. When injected in its liquid form, however, ammonia behaves quite differently to traditional fuels due to its high saturation pressure and enthalpy of vaporisation, amongst other things. This means that fundamental data on ammonia sprays need to be collected in order to understand ammonia spray behaviour and calibrate models of ammonia sprays needed for design in the virtual world. Previous work on ammonia sprays has mostly focused on spray morphology at a macroscopic level (such as liquid penetration length). However, there are fewer studies of ammonia sprays at a microscopic level. In this study, liquid ammonia was injected into a constant-volume chamber using a direct injector at two injection pressures (100 bar and 150 bar) and a range of ambient pressures from 3–13 bar. This range of ambient conditions spans regimes from flash-boiling to non-flash-boiling, thereby enabling systematic investigation of the transition between these regimes. A laser diffraction technique was used for measuring the droplet sizes of the spray at different locations (in a cylindrical volume with a diameter of 10 mm) within the spray plume at 10 kHz, and the nominal droplet sizes were quantified by the Sauter Mean Diameter (SMD). These SMD values provided, at a microscopic level, an insight of the atomisation of the spray as it left the nozzle and penetrated into an environment with different densities. It was found that the tested injector leads to a breakup dominant spray behaviour with liquid ammonia and hence the SMD values decrease as ambient pressure increases. In addition, the droplets are generally smaller at the outer edge of the spray plume compared to the inner part and both the injection pressure and injection duration have a strong effect on the droplet sizes
On the characterisation of the time-of-flight VL53L5CX sensor by stmicroelectronics for indoor robotics applications
No full textMiniaturised proximity Time-of-Flight (ToF) sensors are attractive for robotics applications due to their low cost, compact size, and low power consumption, which makes them suitable for direct distribution on the robot body. However, both the accuracy and the reliability of their measurements are influenced by operating conditions and target properties. These aspects are not fully investigated in the manufacturer’s datasheet, yet they play a crucial role in downstream robotic tasks. To address this gap, we mounted three VL53L5CX sensors, an Ambient Light Sensor, and a thermistor on a robotic manipulator in a controlled laboratory setup and executed a series of experiments to characterise sensor performance. Specifically, experiments were conducted to quantify sensor drift over time, the influence of ambient illumination under three office lighting conditions, within-frame beam variability, depth accuracy over the 20–800 mm range for different materials, orientation sensitivity at different distances, and an empirical signal-to-noise ratio. The results reveal a transient warm-up effect at startup, after which measurements stabilise, a near-linear range-dependent bias with substantially larger uncertainty for dark targets, limited within-frame variability, and an invalid measurement rate consistently below 10%. Overall, the VL53L5CX provides repeatable measurements, and the findings of this work can be leveraged to derive more faithful sensor models, apply range bias correction, and broaden the range of robotic applications
Poetics of psalm-creation in Jonah
No full textJonah's prayer presents significant historical-critical and hermeneutical challenges, particularly due to its placement within the book’s narrative and its striking resemblance to several Psalms. Its position within the story raises questions about its function and coherence, while its heavy reliance on psalmic language complicates attempts to determine its originality. Scholars have often approached this passage in two divergent ways: either atomizing the text with critical tools that fragment its meaning or flattening it through overly literary analyses that overlook its compositional complexity.This thesis proposes a way forward by offering an intertextual reading that integrates philological analysis, literary features, and compositional techniques evident in wider Second Temple literature. It adopts a forward-looking, generative hermeneutical approach that prioritizes understanding the creative and interpretive trajectories of texts while cautiously exploring literary dependence.The primary contribution of this thesis is its intertextual reading of Jonah 2, presented in chapter two. This analysis demonstrates that Jonah (the author through the character) strategically incorporates psalmic language to craft an original composition, portraying his descent into the sea as an exile-like experience and casting himself as an innocent sufferer. This reading is supported by a close examination of specific Psalms that feature prominently in Jonah’s prayer.Ultimately, this study argues that these psalms reflect a broader interpretive tradition in which suffering in watery chaos is frequently associated with the experience of exile as an innocent sufferer. By tracing these intertextual connections, the thesis demonstrates how Jonah’s psalm subtly yet profoundly appeals to God’s justice, linking his prayer with traditions found in Lamentations 3, Isaiah 53, and Job. This approach not only deepens our understanding of Jonah 2 but also sheds light on the dynamic ways biblical texts were creatively reinterpreted in later Jewish thought
Civil wars, land conflicts and the consequences of violence: a case study of Teso Uganda (Ca.1996-2014)
No full textThis study examines the complex relationship between civil wars and land disputes in the Teso sub-region of Eastern Uganda between 1996 and 2014. Drawing on historical analysis, qualitative fieldwork, and interviews with local stakeholders, the research explores how decades of armed conflict-including insurgencies led by the Uganda People's Army (UPA) and the Lord’s Resistance Army (LRA)-have disrupted land tenure systems, displaced populations, and eroded traditional land governance structures. The findings reveal that the conflict not only intensified land scarcity but also destroyed the oral and customary frameworks previously used to mediate ownership and access, especially in a context dominated by customary land tenure. The study further highlights how post-war legal reforms, including the 1998 Land Act, have inadequately addressed the realities of rural communities, often reinforcing inequalities due to the high cost of land registration and the exclusion of vulnerable groups such as widows and returnees. It is argued that sustainable land justice in Teso requires a hybrid approach that harmonizes formal legal structures with revitalized customary practices, while promoting gender equity, institutional trust, and grassroots reconciliation. The study contributes to a broader understanding of post-conflict land governance and provides policy-relevant recommendations aimed at fostering peace, social cohesion, and equitable land access in fragile regions