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Abiotic stress triggers electrical synchronisation of shoot and leaves in soybean plants: a clue for plant attention-like
Get PDFPlants rely on sophisticated intercellular communication to coordinate systemic responses to environmental challenges. Electrical signals contribute for rapid, long-distance integration of plant parts. This study investigated how distinct stressors—localized injury (cutting and fire to a leaflet) and systemic salt stress (applied to the roots)—triggered electrical synchronization across different modules (stem and leaves) in soybean (Glycine max) plants. We continuously recorded variations of electrical potential from four plant modules before and after stress application. Time-series analyses, including Detrended Fluctuation Analysis (DFA), Approximate Entropy (ApEn), Fast Fourier Transform (FFT), and Power Spectral Density (PSD), were employed to characterize signal features. Inter-modular synchronization was then assessed by Pearson correlation of these derived features between the modules. The results indicate that different stressors modulate electrical synchronization between plant modules in distinct ways: while cutting and fire stress induce a more immediate and integrated response, showed as higher correlation between modules, salt stress promotes more gradual changes in signal dynamics. These findings reinforce the hypothesis that electrical signalling plays an important role in the functional integration of stress responses, and may indicate a possible attentional state in plants
Error-correction across gauged and ungauged locations: a data assimilation-inspired approach to post-processing river discharge forecasts
No full textForecasting river discharge is essential for disaster risk reduction and water resource management, but forecasts of the future river state often contain errors. Post-processing reduces forecast errors but is usually only applied at the locations of river gauges, leaving the majority of the river network uncorrected. Here, we present a data-assimilation-inspired method for error-correcting ensemble simulations across gauged and ungauged locations in a post-processing step. Our new method employs state augmentation within the framework of the Local Ensemble Transform Kalman Filter (LETKF). Using the LETKF, an error vector representing the forecast residual is estimated for each ensemble member. The LETKF uses ensemble error covariances to spread observational information from gauged to ungauged locations in a dynamic and computationally efficient manner. To improve the efficiency of the LETKF we define new localisation, covariance inflation, and initial ensemble generation techniques that can be easily transferred between modelling systems and river catchments. We implement and evaluate our new error-correction method for the entire Rhine-Meuse catchment using forecasts from the Copernicus Emergency Management Service's European Flood Awareness System (EFAS). The resulting river discharge ensembles are error-corrected at every grid box but remain spatially and temporally consistent. A spatial cross-validation strategy is used to assess the ability of the method to spread the correction along the river network to ungauged locations. The skill of the ensemble mean is improved at almost all locations including stations both up- and downstream of the assimilated observations. Whilst the ensemble spread is improved at short lead-times, at longer lead-times the ensemble spread is too large leading to an underconfident ensemble. In summary, our method successfully propagates error information along the river network, enabling error correction at ungauged locations. This technique can be used for improved post-event analysis and can be developed further to post-process operational forecasts providing more accurate knowledge about the future states of rivers
The impact of CEO political ideology on labor cost reductions and payout decisions during the COVID-19 pandemic
No full textUsing a hand-collected dataset, we study whether CEO political ideology affected S&P 500 firms’ reactions to the COVID-19 pandemic in 2020. During the pandemic, CEOs had the option to distribute the pain of the pandemic’s impact onto shareholders by paying lower dividends, onto the workforce by reducing labor costs, or to share the pain. We hypothesize that conservative CEOs were more likely to aggressively reduce labor costs while still meeting dividend expectations. Conversely, other CEOs would have been less likely to meet dividend expectations and less likely to reduce labor costs. Our findings support this hypothesis. We also find that during the pandemic, conservative CEOs used temporary downsizing to avoid earnings losses, enabling them to meet dividend expectations
From wasteland to wonderland: brownfield land and registers as catalyst for addressing urban housing needs
No full textThis study investigates the utilization of brownfield land registers and the potential of brownfield land for urban regeneration in the UK, focusing on Central London to address housing shortages. Using a constructivist qualitative research design, the study engaged 31 participants and employed a three-stage data analysis process. The findings reveal significant underutilization of brownfield land, highlighting "politics and planning" as key barriers. The study emphasizes the need for policymakers to collaborate with industry stakeholders, update brownfield land registers more frequently, and address identified constraints to enhance the effective utilization of brownfield land, offering valuable insights for global urban regeneration efforts
Video is worth a thousand images: exploring the latest trends in long video generation
No full textAn image may convey a thousand words, but a video, composed of hundreds or thousands of image frames, tells a more intricate story. Despite significant progress in multimodal large language models (MLLMs), generating extended videos remains a formidable challenge. As of this writing, OpenAI’s Sora [1], the current state-of-the-art system, is still limited to producing videos of up to one minute in length. This limitation stems from the complexity of long video generation, which requires more than generative AI techniques for approximating density functions. Critical elements, such as planning, narrative construction, and spatiotemporal continuity, pose significant challenges. Integrating generative AI with a divide-and-conquer approach could improve scalability for longer videos while offering greater control. In this survey, we examine the current landscape of long video generation, covering foundational techniques such as GANs and diffusion models, video generation strategies, large-scale training datasets, quality metrics for evaluating long videos, and future research areas to address the limitations of existing video generation capabilities. We believe it would serve as a comprehensive foundation, offering extensive information to guide future advancements and research in the field of long video generation
Essays on cross-border M&A and corporate conduct: evidence from environmental, offshore, and societal institutional contexts
No full textThis thesis comprises three empirical essays that explore how institutional environments affect
firms’ cross-border strategic behaviour and financial conduct. Particularly, the thesis provides
new insights into the mechanisms through which climate change related risks, offshore
relationships, and societal trust influence corporate decisions.
The first essay (Chapter 3) examines the role of greenhouse gas (GHG) emissions in shaping a
firm’s international acquisition choices. Specifically, it investigates how U.S. firms’ carbon
emissions levels influence their cross-border mergers and acquisitions (M&A). The findings
show that firms with higher intensity of emissions are more likely to pursue cross-border deals,
especially in countries with weaker environmental regulations, lower disclosure standards, and
reduced transparency. This pattern intensifies after the Paris Agreement and is consistent with
motives of regulatory arbitrage.
The second essay (Chapter 4) investigates how offshore activities affect cross-border
acquisitions. Using a novel text-based measure of offshore engagement based on Hoberg and
Moon (2017, 2019), the study finds that firms are significantly more likely to acquire targets
in countries where they have prior offshore trading ties. This effect is stronger in countries with
better information environments. However, the results show no significant improvement in deal
performance or return on assets (ROA) following the acquisitions.
The third essay (Chapter 5) turns to the influence of informal institutions by examining the
relationship between regional societal trust and earnings management among Chinese listed
firms. The analysis reveals that firms headquartered in high-trust regions are less likely to
engage in opportunistic earnings manipulation. This effect is more pronounced in regions with
greater market development and better information quality, and weaker where media scrutiny
is higher.
Collectively, these essays contribute to a deeper understanding of how institutional
asymmetries across countries and regions influence firm-level strategies, particularly in the
domains of cross-border expansion and financial reporting behaviour
“The Ancient Romans conquered all Syria and Egypt”: encounters between Arabic and the Classics in the nineteenth century
No full textTourists’ local food consumption: travel experience, responsible tourism, or both?
Get PDFThis paper examines the factors influencing tourists’ local food consumption by focusing on the effectiveness of message appeals and the role of cultural and ethical considerations. An online experimental study assessed the impact of different marketing messages on tourists' attitudes and intentions toward local food consumption. Additionally, an online survey examined the interplay between cultural and ethical factors in shaping tourists' behaviors and decisions regarding local food. The findings indicated that integrating ethical considerations enhances the effectiveness of marketing messages and strengthens the influence of cultural factors on tourists' consumption behaviors. The paper discusses the implications for responsible tourism, emphasizing the need for tourism promotion strategies to integrate local food experiences with both cultural and ethical values to encourage more sustainable travel choices
Nesterov acceleration for ensemble Kalman inversion and variants
Get PDFEnsemble Kalman inversion (EKI) is a derivative-free, particle-based optimization method for solving inverse problems. It can be shown that EKI approximates a gradient flow, which allows the application of methods for accelerating gradient descent. Here, we show that Nesterov acceleration is effective in speeding up the reduction of the EKI cost function on a variety of inverse problems. We also implement Nesterov acceleration for two EKI variants, unscented Kalman inversion and ensemble transform Kalman inversion. Our specific implementation takes the form of a particle-level nudge that is demonstrably simple to couple in a black-box fashion with any existing EKI variant algorithms, comes with no additional computational expense, and with no additional tuning hyperparameters. This work shows a pathway for future research to translate advances in gradient-based optimization into advances in gradient-free Kalman optimization