Hasil untuk "Natural history (General)"

Xinyi Guo, Rui Ma, Jianrong Zhu et al.

Estuarine saltwater intrusion is mainly controlled by river discharge, tide and wind. It is important for utilization of estuarine freshwater to study quantitative relationship between unsuitable water intake time and river discharge. A two-way nested unstructured quadrilateral grid, finite-differencing, three-dimensional estuarine and coastal ocean model (UFDECOM-i) was applied to simulate the saltwater intrusion in the Changjiang Estuary and to get the quantitative relationship between unsuitable water intake time at Qingcaosha Reservoir and river discharge under different northerly wind speeds. The results of numerical experiments show that the salinity at the water intake of Qingcaosha Reservoir is very sensitive to the variation in river discharge. Under 7 day northerly wind of 10 m/s, when the river discharge is 8000 m3/s, the entire estuary is occupied by saline water; the net unit width salt flux (NUSF) landward flows in the North Channel, then flows into the South Channel toward sea, forming a horizontal salt transport route of “flowing into the North Channel and out in the South Channel” due to the strong landward Ekman transport. When the river discharge is 12000 m3/s, the horizontal salt transport route is weakened with the increase of river discharge. Under 7 day northerly wind of 15 m/s, saltwater intrusion increases significantly with the increase of wind speed, and the pattern of NUSF become much stronger. The salinity increases enormously after the action of persistent strong northerly wind. The quantitative relationship between river discharge and the longest continuous unsuitable water intake time of Qingcaosha Reservoir is expressed by formula under climatic wind, 7 day northerly wind of 10 m/s and 15 m/s, respectively, with correlation coefficient R2 of greater than 0.97, which can provide a basis for reservoir water intake and water supply safety.

Chang-yan Xu, Yi-qun Wang, Di-lin Yao et al.

The marine green fuel supply chain is a crucial component in the development of green ports. Focusing on the issue of cooperative contracts between the port and green marine fuel supplier within the marine green fuel supply chain, first, a two-echelon marine green fuel supply chain optimization model consisting of a green marine fuel supplier and a port was constructed. Second, the changes in profits and decisions of a green marine fuel supplier and a port were compared under four scenarios: no contract, cost-sharing contract, revenue-sharing contract, and combined revenue-sharing + cost-sharing contract. Finally, the propositions were validated using numerical simulation methods. The research findings show that, in terms of revenue, the combined profits of a port and green marine fuel supplier under the combined revenue-sharing + cost-sharing contract exceeded those under the revenue-sharing contract alone. Regarding the sales price of marine green fuel and bunkering service quality, these factors peaked under the cost-sharing contract and were at their lowest under the revenue-sharing contract. An increase in the port’s investment proportion in marine green fuel bunkering service quality led to decreases in the bunkering volume, sales price, wholesale price, and bunkering service quality of marine green fuel under both the cost-sharing contract and the revenue-sharing + cost-sharing contract. Additionally, the higher proportion of revenue shared by the port with the green marine fuel supplier resulted in lower sales price, wholesale price, and bunkering service quality of green marine fuel under both the revenue-sharing contract and revenue-sharing + cost-sharing contract.

Guo Zhong, Longwu Wang, Wei Liang

Egg color polymorphism and egg mimicry are important adaptations in the game process between hosts and brood parasites at the egg stage. The ability of hosts to recognize and reject parasitic eggs based on effective egg characteristics is a crucial factor in determining the outcome of this arms race. The evolution of linear markings on eggs has been identified in several parasitic systems of common cuckoos Cuculus canorus, yet little is known about the functional adaptation of this egg characteristic. Here, we examined the recognition and utilization methods of maculation signals of eggs in the common cuckoo hosts, south rock bunting Emberiza yunnanensis, which lays eggs with linear mimetic spots, and yellow‐throated bunting Emberiza elegans, which lays eggs with dotted mimetic spots. The results demonstrated that both species of bunting hosts show moderate recognition and rejection levels towards interspecific eggs (spotted versus streaked). Moreover, during recognition, they utilized the contrast between the maculation and the egg background rather than the contrast between the maculations themselves. Our study is the first to demonstrate that two species of open‐nesting buntings use achromatic contrast (not chromatic contrast) between pattern features and egg background color to identify and reject foreign eggs. However, whether other differences in pattern features, such as pattern density, distribution, and proportion are utilized by the hosts requires further verification.

Tao Liu, Chongyu Wang, Rongjie Li et al.

While Multimodal Large Language Models (MLLMs) have advanced GUI navigation agents, current approaches face limitations in cross-domain generalization and effective history utilization. We present a reasoning-enhanced framework that systematically integrates structured reasoning, action prediction, and history summarization. The structured reasoning component generates coherent Chain-of-Thought analyses combining progress estimation and decision reasoning, which inform both immediate action predictions and compact history summaries for future steps. Based on this framework, we train a GUI agent, \textbf{GUI-Rise}, through supervised fine-tuning on pseudo-labeled trajectories and reinforcement learning with Group Relative Policy Optimization (GRPO). This framework employs specialized rewards, including a history-aware objective, directly linking summary quality to subsequent action performance. Comprehensive evaluations on standard benchmarks demonstrate state-of-the-art results under identical training data conditions, with particularly strong performance in out-of-domain scenarios. These findings validate our framework's ability to maintain robust reasoning and generalization across diverse GUI navigation tasks. Code is available at https://leon022.github.io/GUI-Rise.

Rodrigo A. Estévez, Natalio Godoy, Miguel Araya et al.

Abstract Marine recreational fisheries often lack necessary information to perform assessments and develop sustainable management strategies. In Chile, although reef‐fish fisheries have been signaled as overexploited, there are still no commercial or recreational regulations regarding bans, catch limits, or size limits. We implemented an expert elicitation protocol to propose management measures to regulate recreational reef‐fish harvests of 17 reef‐fish species. Sixteen experts estimated minimum legal sizes, temporal closures, and maximum number of individuals harvested per person per trip (known as “bag limits”). Experts also prioritized management measures for each of 17 reef‐fish species. Maximum number of individuals harvested per person per trip varied between 1 and 7. In addition, permanent bans were recommended for some species, such as acha (Medialuna ancietae), pejeperro (Semicossyphus darwini), and San Pedro (Oplegnathus insignis). We concluded that information gathered through expert elicitation can play a key role to inform data‐poor recreational fishery management. Expert elicitation protocols that include iterative process, based on individual estimates and an open expert discussion phase, provide the necessary enabling environment to identify a variety of management measures. While future challenges include the development of mechanisms to promote acceptability and compliance for recreational fisheries management, the approach presented here is important to initiate much needed discussions.

Dylan Galt, Langte Ma

We study generalized anti-self-dual instantons defined over Riemannian manifolds equipped with a parallel codimension-$4$ differential form. In particular, for product Riemannian manifolds possessing such a form, we study dimension reduction phenomena, finding a topological criterion for bundles which, when satisfied, allows for a complete characterization of dimension reduction for the corresponding moduli space of generalized ASD instantons. By establishing an integrability result for families of connections, we then deduce explicit descriptions for these moduli spaces, including those of Hermitian Yang--Mills connections, $G_2$-, and $\Spin(7)$-instantons. When one factor in the product is a $4$-manifold, we establish well-behaved compactifications for these moduli spaces.

Irem Islek, Sule Gunduz Oguducu

Recommendation systems can provide accurate recommendations by analyzing user shopping history. A richer user history results in more accurate recommendations. However, in real applications, users prefer e-commerce platforms where the item they seek is at the lowest price. In other words, most users shop from multiple e-commerce platforms simultaneously; different parts of the user's shopping history are shared between different e-commerce platforms. Consequently, we assume in this study that any e-commerce platform has a complete record of the user's history but can only access some parts of it. If a recommendation system is able to predict the missing parts first and enrich the user's shopping history properly, it will be possible to recommend the next item more accurately. Our recommendation system leverages user shopping history to improve prediction accuracy. The proposed approach shows significant improvements in both NDCG@10 and HR@10.

Gabriel Nakamura, Bruno Eleres Soares, Valério D. Pillar et al.

Yaamini R. Venkataraman, Amanda Shore, Sukanya Dayal et al.

IntroductionSeagrass meadows serve as an integral component of coastal ecosystems but are declining rapidly due to numerous anthropogenic stressors including climate change. Eelgrass wasting disease, caused by opportunistic Labyrinthula spp., is an increasing concern with rising seawater temperature. To better understand the host-pathogen interaction, we paired whole organism physiological assays with dual transcriptomic analysis of the infected host and parasite. MethodsEelgrass (Zostera marina) shoots were placed in one of two temperature treatments, 11° C or 18° C, acclimated for 10 days, and exposed to a waterborne inoculation containing infectious Labyrinthula zosterae (Lz) or sterile seawater. At two- and five-days post-exposure, pathogen load, visible disease signs, whole leaf phenolic content, and both host- and pathogen- transcriptomes were characterized. ResultsTwo days after exposure, more than 90% of plants had visible lesions and Lz DNA was detectable in 100% percent of sampled plants in the Lz exposed treatment. Concentrations of total phenolic compounds were lower after 5 days of combined exposure to warmer temperatures and Lz, but were unaffected in other treatments. Concentrations of condensed tannins were not affected by Lz or temperature, and did not change over time. Analysis of the eelgrass transcriptome revealed 540 differentially expressed genes in response to Lz exposure, but not temperature. Lz-exposed plants had gene expression patterns consistent with increased defense responses through altered regulation of phytohormone biosynthesis, stress response, and immune function pathways. Analysis of the pathogen transcriptome revealed up-regulation of genes potentially involved in breakdown of host defense, chemotaxis, phagocytosis, and metabolism. DiscussionThe lack of a significant temperature signal was unexpected but suggests a more pronounced physiological response to Lz infection as compared to temperature. Pre-acclimation of eelgrass plants to the temperature treatments may have contributed to the limited physiological responses to temperature. Collectively, these data characterize a widespread physiological response to pathogen attack and demonstrate the value of paired transcriptomics to understand infections in a host-pathogen system.

Linchao He, Hongyu Yan, Mengting Luo et al.

Diffusion models have recently been recognised as efficient inverse problem solvers due to their ability to produce high-quality reconstruction results without relying on pairwise data training. Existing diffusion-based solvers utilize Gradient Descent strategy to get a optimal sample solution. However, these solvers only calculate the current gradient and have not utilized any history information of sampling process, thus resulting in unstable optimization progresses and suboptimal solutions. To address this issue, we propose to utilize the history information of the diffusion-based inverse solvers. In this paper, we first prove that, in previous work, using the gradient descent method to optimize the data fidelity term is convergent. Building on this, we introduce the incorporation of historical gradients into this optimization process, termed History Gradient Update (HGU). We also provide theoretical evidence that HGU ensures the convergence of the entire algorithm. It's worth noting that HGU is applicable to both pixel-based and latent-based diffusion model solvers. Experimental results demonstrate that, compared to previous sampling algorithms, sampling algorithms with HGU achieves state-of-the-art results in medical image reconstruction, surpassing even supervised learning methods. Additionally, it achieves competitive results on natural images.

Wei-Ping Chan, Richard Rabideau Childers, Sorcha Ashe et al.

An accessible approach to multispectral imaging analysis of museum butterfly specimens is presented using consumer technology.

Eslam Gabreil, Haitao Wu, Haitao Wu et al.

In this study, a three-dimensional (3D) numerical model based on the smoothed particle hydrodynamics (SPH) approach was developed to simulate the near-shore current flows over a rough topographic surface in the coastal area, where the flows are shallow and demonstrate strong turbulent characteristics. The numerical program is based on the open-source code SPHysics (http://www.sphysics.org), and two major improvements are made to treat the turbulence and rough boundary effects: A modified sub-particle-scale (SPS) eddy viscosity model is developed to address the turbulence transfer of flows, and a drag force equation is included in the momentum equations to account for the influence of roughness element on the bed and lateral boundaries. The computed results of flow velocity, shear stress, and free surface characteristics are compared with the laboratory measurements for a variety of test conditions. It has shown that the present SPH model can accurately simulate 3D-free surface near-shore current flows over a realistic topography with roughness.

M. Ranjith, M. M. Rocha, C. M. Kalleshwaraswamy et al.

Until now, the occurrence of Pericapritermes ceylonicus (Holmgren) was not confirmed in the Indian mainland. Here, we document the occurrence of this species from Karnataka state constituting its first report from India. The species was identified based on the soldier caste, and the worker characters were described for the first time, including the digestive tube and enteric valve armature. The enteric valve was characterized by the presence of gradually reducing triangular spines. The study provides the basis for further taxonomic characterization of Pericapritermes occurring in India using gut morphology of workers.

Ann Weaver

Adaptation is a biological mechanism by which organisms adjust physically or behaviorally to changes in their environment to become more suited to it. This is a report of free-ranging bottlenose dolphins’ behavioral adaptations to environmental changes from coastal construction in prime habitat. Construction was a 5-year bridge removal and replacement project in a tidal inlet along west central Florida’s Gulf of Mexico coastline. It occurred in two consecutive 2.5-year phases to replace the west and east lanes, respectively. Lane phases involved demolition/removal of above-water cement structures, below-water cement structures, and reinstallation of below + above water cement structures (N = 2,098 photos). Data were longitudinal (11 years: 2005–2016, N = 1,219 surveys 2–4 times/week/11 years, N = 4,753 dolphins, 591.95 h of observation in the construction zone, 126 before-construction surveys, 568 during-construction surveys, 525 after-construction surveys). The dependent variable was numbers of dolphins (count) in the immediate construction zone. Three analyses examined presence/absence, total numbers of dolphins, and numbers of dolphins engaged in five behavior states (forage-feeding, socializing, direct travel, meandering travel, and mixed states) across construction. Analyses were GLIMMIX generalized linear models for logistic and negative binomial regressions to account for observation time differences as an exposure (offset) variable. Results showed a higher probability of dolphin presence than absence before construction began, more total dolphins before construction, and significant decreases in the numbers of feeding but not socializing dolphins. Significant changes in temporal rhythms also revealed finer-grained adaptations. Conclusions were that the dolphins adapted to construction in two ways, by establishing feeding locations beyond the disturbed construction zone and shifting temporal rhythms of behaviors that they continued to exhibit in the construction zone to later in the day when construction activities were minimized. This is the first study to suggest that the dolphins learned to cope with coastal construction with variable adjustments.

Emmanuel F. A. Toussaint, Lloyd T. White, Helena Shaverdo et al.

Abstract Background The New Guinean archipelago has been shaped by millions of years of plate tectonic activity combined with long-term fluctuations in climate and sea level. These processes combined with New Guinea’s location at the tectonic junction between the Australian and Pacific plates are inherently linked to the evolution of its rich endemic biota. With the advent of molecular phylogenetics and an increasing amount of geological data, the field of New Guinean biogeography begins to be reinvigorated. Results We inferred a comprehensive dated molecular phylogeny of endemic diving beetles to test historical hypotheses pertaining to the evolution of the New Guinean biota. We used geospatial analysis techniques to compare our phylogenetic results with a newly developed geological terrane map of New Guinea as well as the altitudinal and geographic range of species ( https://arcg.is/189zmz ). Our divergence time estimations indicate a crown age (early diversification) for New Guinea Exocelina beetles in the mid-Miocene ca. 17 Ma, when the New Guinean orogeny was at an early stage. Geographic and geological ancestral state reconstructions suggest an origin of Exocelina ancestors on the eastern part of the New Guinean central range on basement rocks (with a shared affinity with the Australian Plate). Our results do not support the hypothesis of ancestors migrating to the northern margin of the Australian Plate from Pacific terranes that incrementally accreted to New Guinea over time. However, our analyses support to some extent a scenario in which Exocelina ancestors would have been able to colonize back and forth between the amalgamated Australian and Pacific terranes from the Miocene onwards. Our reconstructions also do not support an origin on ultramafic or ophiolite rocks that have been colonized much later in the evolution of the radiation. Macroevolutionary analyses do not support the hypothesis of heterogeneous diversification rates throughout the evolution of this radiation, suggesting instead a continuous slowdown in speciation. Conclusions Overall, our geospatial analysis approach to investigate the links between the location and evolution of New Guinea’s biota with the underlying geology sheds a new light on the patterns and processes of lineage diversification in this exceedingly diverse region of the planet.

Zhuo Xu, Masayoshi Tomizuka

In this extended abstract, we investigate the design of learning representation for human intention inference. In our designed human intention prediction task, we propose a history encoding representation that is both interpretable and effective for prediction. Through extensive experiments, we show our prediction framework with a history encoding representation design is successful on the human intention prediction problem.

Sérgio N. Stampar, V. Sadie Mills, Stephen J. Keable

The fauna of Ceriantharia (tube-anemones) in the South Pacific is poorly studied with only four shallow-water species formally described and these animals are known from few regions in very specific reports. Cerianthids are organisms that live in a tube constructed with a special type of cnidae and are currently grouped in an exclusive subclass of Anthozoa. This study addresses specimens from three natural history collections, the Australian Museum and the Museum and Art Gallery of the Northern Territory (both Australia), and the National Institute of Water & Atmospheric Research (NIWA) Invertebrate Collection (New Zealand), focusing on specimens from the Coral Sea, Tasman Sea and Antarctic Ocean. As a result, four new species are described and one synonymized. This highlights the ongoing need for taxonomic studies in the region, especially for marine organisms. Also, in this study, we offer tables with morphological characters that can be useful for species identification in each genus.

John H. Powell, Matthew R. Campbell

Abstract Genetic stock identification is a widely applied tool for the mixed‐stock management of salmonid species throughout the North Pacific Rim. The effectiveness of genetic stock identification is dependent on the level of differentiation among stocks which is often high due to the life history of these species that involves high homing fidelity to their natal streams. However, the utility of this tool can be reduced when natural genetic structuring has been altered by hatchery translocation and/or supplementation. We examined the genetic population structure of ESA‐listed steelhead in the Snake River basin of the United States. We analyzed 9,613 natural‐origin adult steelhead returning to Passive Integrated Transponder detection sites throughout the basin from 2010 through 2017. Individuals were genotyped at 180 single nucleotide polymorphic genetic markers and grouped into 20 populations based on their return location. While we expected to observe a common pattern of hierarchical genetic structuring due to isolation by distance, we observed low genetic differentiation between populations in the upper Salmon River basin compared to geographically distant populations in the lower Snake River basin. These results were consistent with lower genetic stock assignment probabilities observed for populations in this upper basin. We attribute these patterns of reduced genetic structure to the translocation of lower basin steelhead stocks and ongoing hatchery programs in the upper Salmon River basin. We discuss the implications of these findings on the utility of genetic stock identification in the basin and discuss opportunities for increasing assignment probabilities in the face of low genetic structure.

Alexander Gallego Cadavid, Yeinzon Rodriguez, L. Gabriel Gomez

As a modified gravity theory that introduces new gravitational degrees of freedom, the generalized SU(2) Proca theory (GSU2P for short) is the non-Abelian version of the well-known generalized Proca theory where the action is invariant under global transformations of the SU(2) group. This theory was formulated for the first time in Phys. Rev. D 94 (2016) 084041, having implemented the required primary constraint-enforcing relation to make the Lagrangian degenerate and remove one degree of freedom from the vector field in accordance with the irreducible representations of the Poincaré group. It was later shown in Phys. Rev. D 101 (2020) 045008, ibid 045009, that a secondary constraint-enforcing relation, which trivializes for the generalized Proca theory but not for the SU(2) version, was needed to close the constraint algebra. It is the purpose of this paper to implement this secondary constraint-enforcing relation in GSU2P and to make the construction of the theory more transparent. Since several terms in the Lagrangian were dismissed in Phys. Rev. D 94 (2016) 084041 via their equivalence to other terms through total derivatives, not all of the latter satisfying the secondary constraint-enforcing relation, the work was not so simple as directly applying this relation to the resultant Lagrangian pieces of the old theory. Thus, we were motivated to reconstruct the theory from scratch. In the process, we found the beyond GSU2P.

Mariateresa Crosta

This essay demonstrates the key role of Astronomy in Botticelli's "Venus and Mars-NG915" painting, to date only very partially understood. Worthwhile coincidences among the principles of the Ficinian philosophy, the historical characters involved and the compositional elements of the painting, show how the astronomical knowledge of that time strongly influenced this masterpiece. First, Astronomy provides its precise dating since the artist used the astronomical ephemerides of his time, albeit preserving a mythological meaning, and a clue for Botticelli's signature. Second, it allows the correlation among Botticelli's creative intention, the historical facts and the astronomical phenomena such as the heliacal rising of the planet Venus in conjunction with the Aquarius constellation dating back to the earliest representations of Venus in Mesopotamian culture. This work not only bears a significant value for the history of science and art, but, in the current era of three-dimensional mapping of billion stars about to be delivered by Gaia, states the role of astronomical heritage in Western culture. Finally, following the same method, a precise astronomical dating for the famous Primavera painting is suggested.