Hasil untuk "Natural history (General)"

Junhe Mao, Feng Li, Jiaqing Hu

Maritime accidents are lethal threats to lives, economies, and the environment as a result of which there is a need to develop advanced prediction models for early risk identification. In this paper, a novel framework integrated with Capsule Neural Networks (CapsNets) and a Modified Orangutan Optimization (MOO) algorithm is proposed to predict maritime accident hotspots. The CapsNet model captures spatio-temporal dependencies from the Global Maritime Distress and Safety System (GMDSS) dataset, while the MOO fine-tunes hyperparameters toward maximizing model accuracy and generalization. Experimental results suggest that the framework works exceedingly well against the baseline models by achieving an accuracy of 91.2%, while improving precision and recall, and reducing error rates on the contrary. Geospatial heatmaps and decision boundary visualizations strengthen the claim regarding the model’s capacity to identify high-hazard zones and clearly categorize incident types. Compelling case studies illustrate its potential for reducing response time through proactive monitoring and preparedness, which is possible only through integrating information with prediction methods. The study takes maritime safety analytics into a very intelligent and data-driven domain by overcoming shortcomings of existing predictive methods. The framework opens the door to the future integration into rescue resource planning systems, where predicted risk zones will inform strategies for asset deployment.

Leily Bakhtiari

The Metaverse, as a hypothetical virtual environment utilizing advanced technologies such as Artificial Intelligence and the Internet of Things, has the potential to contribute to the sustainability of future smart cities, enhancing urban efficiency and quality of life. In this regard, the present study aims to analyze the framework of immersive Metaverse spaces for the sustainability of future smart cities in the metropolitan area of Tehran. The research strategy is application-oriented, and the methodology is descriptive-analytical, based on exploratory futures research methods. The theoretical data were collected using a documentary method, and the empirical data were gathered through a survey method based on the Delphi technique. The target population of this study included urban experts, and a purposive sample of 70 individuals was selected. To analyze the data, the Delphi method, structural analysis in the MICMAC environment, and Scenario Wizard software were employed. The findings revealed that indicators such as transparency, demand reduction, urban simulation, and digital education play significant roles in improving smart urban sustainability. Additionally, the study demonstrated that the Metaverse can serve as an effective tool for optimizing resource consumption, increasing citizen participation, and mitigating urban risks. The final results suggest that to fully harness the potential of the Metaverse, it is necessary to strengthen digital infrastructures, enhance technology-related education, and improve cybersecurity. Overall, it is recommended that policymakers in Tehran focus on developing Metaverse technologies and integrating them with urban systems to leverage all the capabilities of this technology.

Laura Russo, Caleb Allen, Cameron S. Jorgensen et al.

Scientists have long been fascinated by magnetoreception, the innate capacity of many animals to sense and use the Earth's magnetic field for navigation. In eusocial insects like honey bees, magnetoreception has been linked to communication and foraging. However, little is known about magnetoreception's phylogenetic patterns and relationship to species traits and natural history. Here, we demonstrate that putative magnetoreception based on ferromagnetic particles is widespread across a diversity of bee species (72 out of 96 species tested), with no phylogenetic signal. We also detected such putative magnetoreception in non-bee outgroups, suggesting this magnetic capacity predates the evolution of the Anthophila. While magnetic signals were found across a diversity of life history traits, the strength of the magnetic signal varied within and between species, and increased with body size and social behavior.

Maggie Dakin, Joshua Patterson, Alex Petrosino et al.

IntroductionIndividuals of some marine species can modify their phenotype in response to environmental factors, allowing them to adapt to new conditions throughout their ontogeny. Echinoids represent an ecologically significant taxon that exhibit such plasticity throughout a biphasic life history in response to known biotic and abiotic factors. Preliminary lab-based observations have suggested that morphological traits, specifically pluteal arm length, may be influenced by physical processes such as hydrodynamic flow during planktotrophic larval development. This dynamic remains understudied despite potentially critical demographic implications.MethodsHere, we tested the effect of continuous exposure to different shear stress treatments on larval morphology and life history timing shifts in three co-occurring species: Lytechinus variegatus, Tripneustes ventricosus, and Diadema antillarum.ResultsBoth T. ventricosus and D. antillarum displayed significantly longer postoral arms and increased percent metamorphic competence in response to greater shear. Treatment effects were not observed for L. variegatus.DiscussionThese findings represent the first observation of morphogenic plasticity in response to a hydrodynamic factor for larval echinoderms. Species-specific effects revealed a plasticity continuum which may be mediated by phylogeny, ecological niche, and/or functional morphology. This dynamic response offers insights into larval dispersal and recruitment potential, adult distribution, and the boom-and-bust cycles characteristic of ecologically relevant echinoid populations.

Amr S. Mohamed, Emily Nguyen, Deepa Kundur

Amidst the growing demand for implementing advanced control and decision-making algorithms|to enhance the reliability, resilience, and stability of power systems|arises a crucial concern regarding the safety of employing machine learning techniques. While these methods can be applied to derive more optimal control decisions, they often lack safety assurances. This paper proposes a framework based on control barrier functions to facilitate safe learning and deployment of reinforcement learning agents for power system control applications, specifically in the context of automatic generation control. We develop the safety barriers and reinforcement learning framework necessary to establish trust in reinforcement learning as a safe option for automatic generation control - as foundation for future detailed verification and application studies.

Ekhi Azurmendi, Joseba Fernandez de Landa, Jaione Bengoetxea et al.

Language models depend on massive text corpora that are often filtered for quality, a process that can unintentionally exclude non-standard linguistic varieties, reduce model robustness and reinforce representational biases. In this paper, we argue that language models should aim to capture the full spectrum of language variation (dialectal, historical, informal, etc.) rather than relying solely on standardized text. Focusing on the Basque language, we construct new corpora combining standard, social media, and historical sources, and pre-train the BERnaT family of encoder-only models in three configurations: standard, diverse, and combined. We further propose an evaluation framework that separates Natural Language Understanding (NLU) tasks into standard and diverse subsets to assess linguistic generalization. Results show that models trained on both standard and diverse data consistently outperform those trained on standard corpora, improving performance across all task types without compromising standard benchmark accuracy. These findings highlight the importance of linguistic diversity in building inclusive, generalizable language models.

Martin Cornillet, Christina Villard, Fredrik Rorsman et al.

Summary: Background: Despite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well-characterised prospective resources is an important contributing factor to the current situation. Methods: We here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10-year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011–April 2016). Findings: Out of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided. Interpretation: We envision the SUPRIM cohort as an open-access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040. Funding: This work was supported by the Swedish Cancer Society, Stockholm County Council, and the Cancer Research Funds of Radiumhemmet.

Davy Fonteyn, Adeline Fayolle, Julia E. Fa et al.

Abstract Engaging local communities is pivotal for wildlife conservation beyond protected areas, aligning with the 30 × 30 target of the Kunming-Montreal Global Biodiversity Framework. We assessed the effectiveness of 33 offtake indicators, derived from hunter declarations, in monitoring the status and extent of degradation of hunted wildlife sourced from camera trap surveys and faunal composition analysis. The rodents:ungulates ratio in offtake and the mean body mass of total offtake emerged as practical and robust indicators of faunal degradation within hunting systems, with significant potential for broader application in similar tropical forest environments. Our findings provide a blueprint for managing and conserving natural resources in tropical regions through community-based initiatives. Involving local stakeholders ensures sustainable wildlife use and fosters ownership and responsibility. This study advances conservation efforts, bridging scientific rigor with community engagement for effective biodiversity preservation.

Holly J. Niner, Siân E. Rees, Giulia La Bianca et al.

Degradation of the natural world and associated ecosystem services is attributed to a historical failure to include its ‘value’ in decision-making. Uncertainty in the quantification of the relationship between natural capital ‘assets’ that give rise to critical societal benefits and people is one reason for the omission of these values from natural resource management. As this uncertainty increases in marine systems and further still with distance from the coast, the connection between society and natural capital assets is less likely to be included adequately in decision-making. Natural capital assets of Areas Beyond National Jurisdiction (ABNJ), including those of the deep sea, are distant but are known to generate many benefits for society, from the diffuse and broad-scale benefits of climate regulation to the provision of wild fish for food. While our understanding of the precise relationships (the status of asset stocks, ecosystem functions and processes) that control the availability of ecosystem services and the flows of benefits is limited, this does not preclude opening a discourse on how these natural capital assets could best be managed to continue to benefit society. Here we apply a natural capital approach to the South East Atlantic ABNJ, one of the least scientifically understood regions of the planet, and develop a framework for risk assessment. We do this by describing the benefit flows from the natural capital assets of the region, appraising how activities are creating pressures on these flows and whether the controls for these pressures protect them. Our risk register highlights how governance currently favours the protection of direct (extractive) benefit flows from natural capital assets of the region, which are primarily targeted for financial benefit. Without a systems-based framework that can account for the cumulative pressures on natural capital assets their status, associated ecosystem services and benefits are at risk. Such an approach is essential to capture and protect the foundational and often diffuse connections between marine natural capital and global society.

Jin L. C. Guo, Jan-Philipp Steghöfer, Andreas Vogelsang et al.

Traceability, the ability to trace relevant software artifacts to support reasoning about the quality of the software and its development process, plays a crucial role in requirements and software engineering, particularly for safety-critical systems. In this chapter, we provide a comprehensive overview of the representative tasks in requirement traceability for which natural language processing (NLP) and related techniques have made considerable progress in the past decade. We first present the definition of traceability in the context of requirements and the overall engineering process, as well as other important concepts related to traceability tasks. Then, we discuss two tasks in detail, including trace link recovery and trace link maintenance. We also introduce two other related tasks concerning when trace links are used in practical contexts. For each task, we explain the characteristics of the task, how it can be approached through NLP techniques, and how to design and conduct the experiment to demonstrate the performance of the NLP techniques. We further discuss practical considerations on how to effectively apply NLP techniques and assess their effectiveness regarding the data set collection, the metrics selection, and the role of humans when evaluating the NLP approaches. Overall, this chapter prepares the readers with the fundamental knowledge of designing automated traceability solutions enabled by NLP in practice.

Jerzy S Respondek

The author was encouraged to write this review by numerous enquiries from researchers all over the world, who needed a ready-to-use algorithm for the inversion of confluent Vandermonde matrices which works in quadratic time for any values of the parameters allowed by the definition, including the case of large root multiplicities of the characteristic polynomial. Article gives the history of the title special matrix since 1891 and surveys algorithms for solving linear systems with the title class matrix and inverting it. In particular, it presents, also by example, a numerical algorithm which does not use symbolic computations and is ready to be implemented in a general-purpose programming language or in a specific mathematical package.

Christopher M. Graney

This paper provides an overview of recent historical research regarding scientifically-informed challenges to the idea that the stars are other suns orbited by other inhabited earths -- an idea that came to be known as "the Plurality of Worlds". Johannes Kepler in the seventeenth century, Jacques Cassini in the eighteenth, and William Whewell in the nineteenth each argued against "pluralism" based on what in their respective times was solid science. Nevertheless, pluralism remained popular despite these and other scientific challenges. This history will be of interest to the astronomical community so that it is better positioned to avoid difficulties should the historical trajectory of pluralism continue, especially as it persists in the popular imagination.

Christina M. Burnham, Erin A. McKenney, Kimberly Ange‐van Heugten et al.

Abstract The southern white rhinoceros (Ceratotherium simum simum) faces an uncertain future in the wild due to increased poaching pressure and habitat fragmentation, thus the management of reproductively successful populations is of critical importance. Successful reproductive outcomes in rhinoceros may be mediated by diet and gut microbial diversity; therefore, understanding gut microbial dynamics within and between captive and wild populations may help improve conservation efforts. Accordingly, gut microbiome preservation methods are needed that are practical for in situ field sampling of wild populations. We evaluated the efficacy of 3 different preservation methods over 2 timepoints for stabilizing microbial communities in feces from southern white rhinoceros (n = 10) at the North Carolina Zoo in Asheboro, North Carolina, USA, during July–September 2020 and January–March 2021. Samples were immediately frozen at −80°C, stored in PERFORMAbiome™·GUT (PB) tubes or stored in 95% ethanol at ambient temperatures (to simulate field conditions), and processed after 14 or 230 days post‐collection. We quantitatively compared alpha and beta diversity across microbial communities and identified taxa that were enriched in each treatment group. Samples preserved in 95% ethanol consistently harbored lower Shannon diversity index (SHDI) and Simpson's diversity (SDI) values compared to Frozen and PB samples. This trend was apparent in both Ethanol day‐14 samples (SHDI 4.94; SDI 0.98) versus Frozen day‐14 (SHDI 5.19; W = 518, P < 0.001; SDI 0.99; W = 476, P < 0.001) and PB day‐14 (SHDI 5.15; W = 430, P < 0.01; SDI 0.99; W = 1075, P = 1) samples, and in Ethanol day‐230 samples (SHDI 4.48; SDI 0.97) versus Frozen day‐230 (SHDI 5.18; W = 0, P < 0.05; SDI 0.99; W = 0, P = 0.032) and PB day‐230 (SHDI 5.23; W = 0, P < 0.05; SDI 0.99; W = 0, P = 0.032) samples. Ethanol day 230 samples differed (P < 0.05) from all other treatments in both alpha and beta diversity indices. Notably, frozen and PB preservation methods maintained compositionally similar microbial communities across both time points. Our results indicate that PB tubes stored at ambient temperatures perform similarly to freezing at −80°C, highlighting their utility for microbiome fieldwork applications. Identifying optimal and versatile microbiome preservation techniques will enable future studies of the gut microbiome in reproductively‐successful wild populations, an effort central to conservation efforts in the southern white rhinoceros and other threatened species.

Maria Barros, Luís Redondo, Duarte Rego et al.

Essential oils, EOs, are concentrated liquids with complex mixtures of volatile organic compounds that can be extracted from different plant materials. EOs have been used by humans throughout history due to their natural properties: from pleasant fragrances, to anti-bacterial/fungal activities. This work presents the impact of pulsed electric fields, PEF, application as a pre-treatment for the extraction of EOs from eucalyptus, rosemary, and thyme leaves. The initial PEF pre-treatment was first applied to eucalyptus and rosemary leaves two weeks after harvesting, with a 2 kV/cm electric field and a specific energy of approximately 10 kJ/kg, followed by EO extraction by hydrodistillation, HD, with distillation times of 30 and 60 min. The best results were obtained for PEF pre-treated samples and 30 min HD, exhibiting an increasing trend in the average extraction yield of approximately 17% and 11% for eucalyptus and rosemary, respectively, in comparison with no PEF applied. The composition of the EOs extracted from eucalyptus was analyzed for their total phenolic content, TPC, where PEF pre-treated samples showed a higher polyphenol extraction, reaching 30% for 30 min HD. Finally, the optimization of the PEF pre-treatment was also studied, for maximizing the quantity of EO extracted from dry thyme leaves, while aiming for a minimization of energy consumption, for different distillation times. For this study it was observed that, for this plant material, an electric field of 1 kV/cm with 0.4 kJ/kg and an HD time of 30 min, after PEF application, was able to achieve an extraction yield up to 40% higher than the conventional method.

Andrea Carosso

In this work, I explore the concept of quantization as a mapping from classical phase space functions to quantum operators. I discuss the early history of this notion of quantization with emphasis on the works of Schrödinger and Dirac, and how quantization fit into their overall understanding of quantum theory in the 1920's. Dirac, in particular, proposed a quantization map which should satisfy certain properties, including the property that quantum commutators should be related to classical Poisson brackets in a particular way. However, in 1946, Groenewold proved that Dirac's mapping was inconsistent, making the problem of defining a rigorous quantization map more elusive than originally expected. This result, known as the Groenewold-Van Hove theorem, is not often discussed in physics texts, but here I will give an account of the theorem and what it means for potential "corrections" to Dirac's scheme. Other proposals for quantization have arisen over the years, the first major one being that of Weyl in 1927, which was later developed by many, including Groenewold, and which has since become known as Weyl Quantization in the mathematical literature. Another, known as Geometric Quantization, formulates quantization in differential-geometric terms by appealing to the character of classical phase spaces as symplectic manifolds; this approach began with the work of Souriau, Kostant, and Kirillov in the 1960's. I will describe these proposals for quantization and comment on their relation to Dirac's original program. Along the way, the problem of operator ordering and of quantizing in curvilinear coordinates will be described, since these are natural questions that immediately present themselves when thinking about quantization.

Maysoon Lundevall-Zara, Maysoon Lundevall-Zara, Maysoon Lundevall-Zara et al.

We report sea-air fluxes of methane in physically and biologically distinct inshore habitats of the Baltic Sea with the goal to establish empirical relationships that allow upscaling of local site-specific flux measurements. Flux measurements were conducted using floating chambers with and without bubble shields, and by using a boundary layer gas transfer model before, during, and after an annually occurring algal bloom from June to October 2019. Water and air temperature, salinity, wind, sediment organic content, and organic content of floating algal biomass were found to successfully discriminate the different habitats in terms of methane flux, both over periods of days and over a season. Multivariate statistical analysis was used to establish the relative environmental forcing of methane emissions over one growth season for each flux method. Floating algal biomass carbon and sediment organic content were identified as the most important controlling factors for methane emissions based on flux chamber measurements over a period of days to weeks, whereas water and air temperature and wind velocity were the most important factors based on the gas transfer model on these time scales. Over the season, water and air temperature were the most important controlling factors with both methods. We present a first attempt how our observations can be extrapolated to determine the coastal methane emission along the coastline.

Fiona Bairstow, Sven Gastauer, Sven Gastauer et al.

Antarctic krill are subject to precautionary catch limits, based on biomass estimates, to ensure human activities do not adversely impact their important ecological role. Accurate target strength models of individual krill underpin biomass estimates. These models are scaled using measured and estimated distributions of length and orientation. However, while the length distribution of a krill swarm is accessible from net samples, there is currently limited consensus on the method for estimating krill orientation distribution. This leads to a limiting factor in biomass calculations. In this work, we consider geometric shape as a variable in target strength calculations and describe a practical method for generating a catalog of krill shapes. A catalog of shapes produces a more variable target strength response than an equivalent population of a scaled generic shape. Furthermore, using a shape catalog has the greatest impact on backscattering cross-section (linearized target strength) where the dominant scattering mechanism is mie scattering, irrespective of orientation distribution weighting. We suggest that shape distributions should be used in addition to length and orientation distributions to improve the accuracy of krill biomass estimates.

Qianchu Zhang, Boris Katsnelson

We report herein an underwater biological chorus coming from the margin of the New Jersey Atlantic continental shelf that we tentatively attribute to a species of fish. The chorus occurred every night for over a month during the Shallow Water 2006 experiment and covers the frequency band 150–4,800 Hz, with maximum intensity in the band from 1450 to 2,000 Hz. Remarkable intensity peaks occurred at 500, 725, 960, 1,215, 1,465, 1,700, and 1,920 Hz, rising to as much as 20 dB above the background noise without the chorus. The chorus begins at sunset and reaches its maximum intensity within an hour, following which it weakens slightly and then gradually climbs again to a peak before sunrise, at which point it quickly weakens and disappears. Its frequency-domain characteristics and the nocturnal timing are reminiscent of sound produced by underwater animals. The intensity of the chorus weakens along the across-shelf path going shoreward, which indicates that the chorus originates from the margin of the continental shelf rather than from the coastal zone, as is generally considered. The chorus contains a single type of acoustic signal that takes the form of double-pulse bursts that last about 8.7 ms, with each pulse containing several acoustic cycles. The time interval between successive bursts varies from 1.5 to 1.9 s. Signals containing a number of bursts vary in length from tens to hundreds of seconds. Although it is impossible to determine the fish species responsible for the chorus, its characteristics, including its low frequency and intensity, its single type of short-duration sound signal, and its multiple peaks in the frequency domain, are all consistent with the general characteristics of fish sounds.

Leigh R. Richards

No abstract available.

Haijiao Liu, Yuyao Song, Xiaodong Zhang et al.

To examine the spatial pattern and controlling factors of the primary productivity (PP) of phytoplankton in the eastern Indian Ocean (EIO), deck-incubation carbon fixation (a 14C tracer technique) and the related hydrographic properties were measured at 15 locations during the pre-summer monsoon season (February–April 2017). There are knowledge gaps in the field observations of PP in the EIO. The estimated daily carbon production rates integrated over the photic zone ranged from 113 to 817 mgC m–2 d–1, with a mean of 522 mgC m–2 d–1. The mixed-layer integrated primary production (MLD-PP) ranged from 29.0 to 303.7 mgC m–2 d–1 (mean: 177.2 mgC m–2 d–1). The contribution of MLD-PP to the photic zone-integrated PP (PZI-PP) varied between 19 and 51% (mean: 36%). Strong spatial variability in the carbon fixation rates was found in the study region. Specifically, the surface primary production rates were relatively higher in the Bay of Bengal domain affected by riverine flux and lower in the equatorial domain owing to the presence of intermonsoonal Wyrtki jets, which were characterized by a depression of thermocline and nitracline. The PZI-PP exhibited a linear (positive) relationship with nutrient values, but with no significance, indicating a partial control of macronutrients and a light limitation of carbon fixation. As evident from the vertical profiles, the primary production process mainly occurred above the nitracline depth and at high photosynthetic efficiency. Phytoplankton (&gt;5 μm), including dinoflagellates, Trichodesmium, coccolithophores, and dissolved nutrients, are thought to have been correlated with primary production during the study period. The measured on-deck biological data of our study allow for a general understanding of the trends in PP in the survey area of the EIO and can be incorporated into global primary production models.