Study region: Arid Central Asia (ACA). Study focus: The contradictory understanding of Holocene climate change trends in ACA remains unresolved. This study compiled Holocene temperature and moisture changes from 23 lacustrine sediment sites in the ACA region based on quantitative proxies (reconstructed temperature and precipitation), physico-chemical proxies (carbon and oxygen isotopes of carbonates), and biological proxies (n-alkanes). New hydrologic insights: Holocene climate patterns characterized by early Holocene cold-dry, mid-Holocene cool-humid, and late Holocene warm-humid conditions in the ACA region. Multiple tipping points have been identified by different proxies during 108 and 6.53 cal ka BP, indicating inconsistencies among compilations of different proxy records. The long-term fluctuating warm-wetting trend in ACA is generally consistent with records from the westerly region, where Holocene climate changes are complex, in contrast to the relatively synchronized patterns in monsoonal Asia. Phase shifts of the North Atlantic Oscillation (NAO), driven by summer and winter insolation variations, caused latitudinal oscillations of westerly moisture transport. During mid-to-late Holocene, NAO negative phases shifted westerly moisture southward, dominating the warming-humidification trend in ACA region. However, the water resources in this region will exhibit complex spatiotemporal differentiation in the future, with wet regions becoming wetter and arid regions drier. This study demonstrates that multi-proxy compilation enhances understanding of regional climate change, but requires discerning environmental signals from different proxies.
Directly employing 3D Gaussian Splatting (3DGS) on images with adverse illumination conditions exhibits considerable difficulty in achieving high-quality, normally-exposed representations due to: (1) The limited Structure from Motion (SfM) points estimated in adverse illumination scenarios fail to capture sufficient scene details; (2) Without ground-truth references, the intensive information loss, significant noise, and color distortion pose substantial challenges for 3DGS to produce high-quality results; (3) Combining existing exposure correction methods with 3DGS does not achieve satisfactory performance due to their individual enhancement processes, which lead to the illumination inconsistency between enhanced images from different viewpoints. To address these issues, we propose LITA-GS, a novel illumination-agnostic novel view synthesis method via reference-free 3DGS and physical priors. Firstly, we introduce an illumination-invariant physical prior extraction pipeline. Secondly, based on the extracted robust spatial structure prior, we develop the lighting-agnostic structure rendering strategy, which facilitates the optimization of the scene structure and object appearance. Moreover, a progressive denoising module is introduced to effectively mitigate the noise within the light-invariant representation. We adopt the unsupervised strategy for the training of LITA-GS and extensive experiments demonstrate that LITA-GS surpasses the state-of-the-art (SOTA) NeRF-based method while enjoying faster inference speed and costing reduced training time. The code is released at https://github.com/LowLevelAI/LITA-GS.
The KM3NeT collaboration recently reported the observation of KM3-230213A, a neutrino event with an energy exceeding 100 PeV, more than an order of magnitude higher than the most energetic neutrino in IceCube's catalog. Given its longer data-taking period and larger effective area relative to KM3NeT, IceCube should have observed events around that energy. This tension has recently been quantified to lie between $2σ$ and $3.5σ$, depending on the neutrino source. A $\mathscr{O}(100)$ PeV neutrino detected at KM3NeT has traversed approximately $147$ km of rock and sea en route to the detector, whereas neutrinos arriving from the same location in the sky would have only traveled through about $14$ km of ice before reaching IceCube. We use this difference in propagation distance to address the tension between KM3NeT and IceCube. Specifically, we consider a scenario in which the source emits sterile neutrinos that partially convert to active neutrinos through oscillations. We scrutinize two such realizations, one where a new physics matter potential induces a resonance in sterile-to-active transitions and another one where off-diagonal neutrino non-standard interactions are employed. In both cases, sterile-to-active neutrino oscillations become relevant at length scales of $\sim100$ km, resulting in increased active neutrino flux near the KM3NeT detector, alleviating the tension between KM3NeT and IceCube. Overall, we propose the exciting possibility that neutrino telescopes may have started detecting new physics.
Study region: Shanghai, China Study focus: This paper proposes a comprehensive framework for quantifying storm surge floods in coastal cities by incorporating the influences of both climate change and urbanization. The framework achieves a physically process-based numerical simulation of storm surge-induced flood hazards due to tropical cyclones in coastal cities by coupling the fast flood inundation model (SFINCS) and the land use change model (GeoSOS-FLUS), along with the numerical nested model for storm surges (Delft 3D Flow & Wave). Using a 1000-year tropical cyclone simulated by the STORM model as an example, this study analyzes and maps coastal flood impacts under the moderate climate scenario (SSPs245) and high emission scenario (SSPs585), and also evaluates the impact of land use changes on these scenarios. New hydrological insights for the region: Taking Shanghai, China as an example, the results show that by 2100, urban land use changes will lead to an increase in the extent of 1000-year TC flooding areas by 4.91–34.00 %, underestimating the inundation area of storm surges if future urban land use changes are not considered. Additionally, our predictions indicate the vulnerability of Chongming island and Changxing island to the impacts of climate change, despite the protective role of coastal embankments considered in the tropical cyclone storm surge simulation. The results of this study represent an important contribution to a better understanding of how future urban land use changes will affect storm surge flooding risks in and around Shanghai. The proposed methodology can be applied to coastal areas worldwide that are vulnerable to tropical cyclones, aiding in the formulation of hazard mitigation policies to alleviate flood impacts in these regions.
Abstract A linear non‐diffusive algorithm for advective transport is developed that greatly improves the detail at which aerosols and clouds can be represented in atmospheric models. Linear advection schemes preserve tracer correlations but the most basic linear scheme is rarely used by atmospheric modelers on account of its excessive numerical diffusion. Higher‐order schemes are in widespread use, but these present new problems as nonlinear adjustments are required to avoid occurrences of negative concentrations, spurious oscillations, and other non‐physical effects. Generally successful at reducing numerical diffusion during the advection of individual tracers, for example, particle number or mass, the higher‐order schemes fail to preserve even the simplest of correlations between interrelated tracers. As a result, important attributes of aerosol and cloud populations including radial moments of particle size distributions, molecular precursors related through chemical equilibria, aerosol mixing state, and distribution of cloud phase are poorly represented. We introduce a new transport scheme, minVAR, that is both non‐diffusive and preservative of tracer correlations, thereby combining the best features of the basic and higher‐order schemes while enabling new features such as the tracking of sub‐grid information at arbitrarily fine scales with high computational efficiency.
Study region: Lower Yangtze River alluvial plain, China. Study focus: The uneven subsidence caused by dewatering in underground engineering constructions in densely populated areas of alluvial plains with an unevenly distributed medium has caused increased concerns. This study applied the transition probability geostatistical software (T-PROGS) geostatistical models based on data from 31 boreholes to characterize a three-dimensional (3D) heterogeneous aquifer (8.8×105 m2 in area and 56 m in depth) in an underground construction area in the alluvial plain of the lower Yangtze River. The SUB model was constructed to simulate the pumping-induced subsidence processes based on a reliable MODFLOW transit flow model. New hydrological insights: The simulation results indicated that surface subsidence increased with pumping and reached a maximum of 33 mm by the end of the extraction (the 14th day). Surface subsidence development exhibited spatial anisotropy around the pumping center, consistent with the observations. Furthermore, the proposed model indicates that hydraulic head evolution and soil compressibility distributions significantly influence the spatial–temporal development of subsidence, implying the significance of the aquifer heterogeneity. The compressible soft soil overlying the pumping section was identified as a vulnerable subsidence zone, suggesting its significance for engineering geological surveys and dewatering designs in underground construction in alluvial plains.
Dominika Prajzlerová, Vojtěch Barták, Petr Keil
et al.
To identify areas of high biodiversity and prioritize conservation efforts, it is crucial to understand the drivers of species richness patterns and their scale dependence. While classified land cover products are commonly used to explain bird species richness, recent studies suggest that unclassified remote-sensed images can provide equally good or better results. In our study, we aimed to investigate whether unclassified multispectral data from Landsat 8 can replace image classification for bird diversity modeling. Moreover, we also tested the Spectral Variability Hypothesis.Using the Atlas of Breeding Birds in the Czech Republic 2014-2017, we modeled species richness at two spatial resolutions of approx. 131 km2 (large squares) and 8 km2 (small squares). As predictors of the richness, we assessed 1) classified land cover data (Corine Land Cover 2018 database), 2) spectral heterogeneity (computed in three ways) and landscape composition derived from unclassified remote-sensed reflectance and vegetation indices. Furthermore, we integrated information about the landscape types (expressed by the most prevalent land cover class) into models based on unclassified remote-sensed data to investigate whether the landscape type plays a role in explaining bird species richness.We found that unclassified remote-sensed data, particularly spectral heterogeneity metrics, were better predictors of bird species richness than classified land cover data. The best results were achieved by models that included interactions between the unclassified data and landscape types, indicating that relationships between bird diversity and spectral heterogeneity vary across landscape types.Our findings demonstrate that spectral heterogeneity derived from unclassified multispectral data is effective for assessing bird diversity across the Czech Republic. When explaining bird species richness, it is important to account for the type of landscape and carefully consider the significance of the chosen spatial scale.
The compact city has become part of the policy orthodoxy in dealing with climate change and other sustainability challenges, and scholars from a diverse set of disciplines have informed this policy through empirical research. In this paper, we argue that attuning research in this field to key perspectives and concepts in human geography and critical urban studies can help ‘diversify’ understandings of compact urbanism in ways that advance social and ecological justice. We show that the compact city has been conceived primarily through the lens of territorially bounded physical urban form, and thereby many of its social, political, and ecological implications are overlooked. Based on this critique, we propose a renewed agenda for compact urbanism that rearticulates it as a strategy for sustainable transformation by bridging socio-material and relational approaches and engaging the human geographical toolbox. Three entry points for this agenda are highlighted: (1) commoning the compact city; (2) metabolism of compact cities; and (3) antagonism in the compact city.
These are notes on the impact of Lagrange's memoir on the construction of geographical maps. We mention the relations of some ideas and questions introduced in this memoir with other notions that appeared later in the works of several mathematicians, including in particular Chebyshev (19th c.) and Darboux (19th-20th c.), two mathematicians who were particularly interested in geography.
The Vera C. Rubin Observatory is slated to observe nearly 20 billion galaxies during its decade-long Legacy Survey of Space and Time. The rich imaging data it collects will be an invaluable resource for probing galaxy evolution across cosmic time, characterizing the host galaxies of transient phenomena, and identifying novel populations of anomalous systems. To facilitate these studies, we introduce a convolutional variational autoencoder trained to estimate the redshift, stellar mass, and star-formation rates of galaxies from multi-band imaging data. We train and test our physics-informed CVAE on a spectroscopic sample of $\sim$26,000 galaxies within $z<1$ imaged through the Dark Energy Camera Legacy Survey. We show that our model can infer redshift and stellar mass more accurately than the latest image-based self-supervised learning approaches, and is >100x faster than more computationally-intensive SED-fitting techniques. Using a small sample of Green Pea and Red Spiral galaxies reported in the literature, we further demonstrate how this CVAE can be used to rapidly identify rare galaxy populations and interpret what makes them unique.
Jing Qiao, Hangbin Wu, Andreas Baumann-Ouyang
et al.
The current terrestrial laser scanners (TLS) are generally equipped with digital cameras which can capture the scene along with the scanner. These two types of sensors offer complementary properties in modeling and visualization of real-world scenes. TLSs can provide geometric information of the real scene with accurate 3D coordinates of the point clouds; cameras are used to acquire high-resolution images and provide good texture information of the environment. Fusing the extracted information from these two sensors helps to create a better virtual representation of the real-world. For a TLS with several external cameras, their acquisition centers are not identical and the axis of their coordinate systems are not aligned either. This paper proposes an automatic camera and TLS extrinsic calibration approach using correspondences extracted from both measurements. To overcome the intrinsic difference between back-projected images of point clouds colored by intensities and the RGB camera images, we innovatively generate both magnitude of gradient images, enabling effective image correlation and accurate correspondence extraction. The 3 external cameras mounted on top, side and bottom of Leica RTC360 3D laser scanner are calibrated. Dependent on the distribution of observations, we achieve different calibration accuracy for each camera. With scans from multiple stations, the cameras obtain an offset accuracy of 0.12 – 0.36 mm and angular accuracy of 3.7 – 8.3″. After calibration, the excellent overlap of images from the two sensors further verifies the proposed method's success. The idea of correspondence identification demonstrated in this study can also be applied to the extrinsic calibration/registration of other types of scanner and digital cameras.
<p>Both marine dinoflagellate cysts and terrestrially derived pollen and spores are abundant in coastal sediments close to river mouths, making sediment records from such settings ideal to simultaneously study land–ocean climate interactions, marine productivity patterns and freshwater input over time. However, few studies consider the combined calibration of these palynological proxies in modern coastal sediments offshore from rivers, which is needed to strengthen the interpretation of paleoreconstructions. Here, we analyze the palynological content of marine surface sediments along land–sea transects off the Mississippi and Atchafalaya river mouths in the northern Gulf of Mexico (GoM) and test three palynological indices which are often employed in the paleo-domain: (i) the abundance of cysts of heterotrophic and autotrophic dinoflagellates (dinocysts) as a tracer for primary productivity (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>H</mi><mo>/</mo><mi>A</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="22pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="fd1af044779a4f8d4f100f2d4e57c845"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00001.svg" width="22pt" height="14pt" src="jm-42-257-2023-ie00001.png"/></svg:svg></span></span> ratio) and (ii) the ratio between non-bisaccate pollen and bisaccates (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mo>/</mo><mi>B</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="8a2e050f4b46caec36f7c0e135e62831"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00002.svg" width="23pt" height="14pt" src="jm-42-257-2023-ie00002.png"/></svg:svg></span></span>) as well as (iii) the ratio between pollen (excluding bisaccates) and dinocysts (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mo>/</mo><mi>D</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1379e013a0c44dbff6a09132ca2d92e3"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00003.svg" width="23pt" height="14pt" src="jm-42-257-2023-ie00003.png"/></svg:svg></span></span>), which are both tracers for river input and distance to the coast.</p>
<p>Our results show that dinoflagellate cysts are most abundant on the shelf, where heterotrophic dinocyst species dominate coastal assemblages in reach of the river plume, while autotrophic taxa are more present in the oligotrophic open ocean. This is clearly reflected in decreasing <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>H</mi><mo>/</mo><mi>A</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="22pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="467b9791936093d95cde6296afe1364b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00004.svg" width="22pt" height="14pt" src="jm-42-257-2023-ie00004.png"/></svg:svg></span></span> values further offshore. Individual dinocyst taxa also seem to inhabit specific niches along an onshore–offshore transect, linked to nutrient availability and proximity to the turbid river plume. The highest pollen concentrations are found close to the Mississippi river mouth and mostly represent a mixture of local coastal and upstream vegetation, whereas bisaccate pollen was most abundant further offshore of the Mississippi river. Multivariate redundancy analysis (RDA) performed on both pollen and dinocyst assemblages, a set of environmental parameters, and the three palynological ratios showed that net primary productivity was the most important variable influencing the dinocyst assemblages, likely as the result of nutrient input. Additionally, the RDA confirmed that the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>H</mi><mo>/</mo><mi>A</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="22pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="e612397d9f3df24db4dde93b9c975102"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00005.svg" width="22pt" height="14pt" src="jm-42-257-2023-ie00005.png"/></svg:svg></span></span> ratio indeed seems to track primary productivity, while the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mo>/</mo><mi>B</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="67f79a7edf7ce2c0ba2f7c7208180fc0"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00006.svg" width="23pt" height="14pt" src="jm-42-257-2023-ie00006.png"/></svg:svg></span></span> ratio results in a robust indicator for distance to the coast, and the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mo>/</mo><mi>D</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="141f3a48f865d92c4ef19785b57e6370"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jm-42-257-2023-ie00007.svg" width="23pt" height="14pt" src="jm-42-257-2023-ie00007.png"/></svg:svg></span></span> ratio better reflects river input. Together, our data confirm and further specify the suitability of these three palynological ratios in river-dominated coastal margins as proxies for (past) marine productivity and distance to the coast and river.</p>
Gergő Tóth, Johannes Wachs, Riccardo Di Clemente
et al.
Social networks amplify inequalities by fundamental mechanisms of social tie formation such as homophily and triadic closure. These forces sharpen social segregation, which is reflected in fragmented social network structure. Geographical impediments such as distance and physical or administrative boundaries also reinforce social segregation. Yet, less is known about the joint relationships between social network structure, urban geography, and inequality. In this paper we analyze an online social network and find that the fragmentation of social networks is significantly higher in towns in which residential neighborhoods are divided by physical barriers such as rivers and railroads. Towns in which neighborhoods are relatively distant from the center of town and amenities are spatially concentrated are also more socially segregated. Using a two-stage model, we show that these urban geography features have significant relationships with income inequality via social network fragmentation. In other words, the geographic features of a place can compound economic inequalities via social networks. Not much is known about the joint relationships between social network structure, urban geography, and inequality. Here, the authors analyze an online social network and find that the fragmentation of social networks is significantly higher in towns in which residential neighborhoods are divided by physical barriers such as rivers and railroads.
In this paper, we study the non-Hermitian physics emerging from a predator-prey ecological model described by a generalized Lotka-Volterra equation. In the phase space, this nonlinear equation exhibits both chaotic and localized dynamics, which are separated by a critical point. These distinct dynamics originate from the interplay between the periodicity and non-Hermiticity of the effective Hamiltonian in the linearized equation of motion. Moreover, the dynamics at the critical point, such as algebraic divergence, can be understood as an exceptional point in the context of non-Hermitian physics.
Sarcopenia is an age-related syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength; it is a major contributor to the risk of physical frailty, functional impairment in older people, poor health-related quality of life and premature death. Many different definitions have been used to describe sarcopenia and have resulted in varying estimates of prevalence of the condition. The most recent attempts of definitions have tried to integrate information on muscle mass, strength and physical function and provide a definition that is useful in both research and clinical settings. This review focuses on the epidemiology of the three distinct physiological components of sarcopenia, and highlights the similarities and differences between their patterns of variation with age, gender, geography and time and the individual risk factors that cluster selectively with muscle mass, strength and physical function. Methods used to measure muscle mass, strength and physical functioning and how differences in these approaches can contribute to the varying prevalence rates will also be described. The evidence for this review was gathered by undertaking a systematic search of the literature. The descriptive characteristics of muscle mass, strength and function described in this review point to the urgent need for a consensual definition of sarcopenia incorporating these parameters.
Arpan Bhattacharjee, Shahriar Badsha, Md Tamjid Hossain
et al.
Cyber-physical systems (CPS) data privacy protection during sharing, aggregating, and publishing is a challenging problem. Several privacy protection mechanisms have been developed in the literature to protect sensitive data from adversarial analysis and eliminate the risk of re-identifying the original properties of shared data. However, most of the existing solutions have drawbacks, such as (i) lack of a proper vulnerability characterization model to accurately identify where privacy is needed, (ii) ignoring data providers privacy preference, (iii) using uniform privacy protection which may create inadequate privacy for some provider while overprotecting others, and (iv) lack of a comprehensive privacy quantification model assuring data privacy-preservation. To address these issues, we propose a personalized privacy preference framework by characterizing and quantifying the CPS vulnerabilities as well as ensuring privacy. First, we introduce a Standard Vulnerability Profiling Library (SVPL) by arranging the nodes of an energy-CPS from maximum to minimum vulnerable based on their privacy loss. Based on this model, we present our personalized privacy framework (PDP) in which Laplace noise is added based on the individual node's selected privacy preferences. Finally, combining these two proposed methods, we demonstrate that our privacy characterization and quantification model can attain better privacy preservation by eliminating the trade-off between privacy, utility, and risk of losing information.
Chengfei He, Zhengyu Liu, Bette L. Otto-Bliesner
et al.
Deglacial hydroclimate in South China is perennially debated. New modeling experiments reveal that regional hydroclimate was strongly influenced by rainfall during the transition between the East Asian summer monsoon and winter monsoon, forced by climate variability in the North Atlantic.