Large Patches Research Articles

Discovery of the Goat Horn complex: a ~1000 deg2 diffuse X-ray source connected to radio loop XII

A dozen patches of polarized radio emission spanning tens of degrees in the form of coherent and stationary arcs and loops are observed at radio frequencies across the sky. Their origin is usually associated with nearby shocks, possibly arising from nearby supernova explosions. The origin of radio loop XII remains unknown. We report an anticorrelation of the radio-polarized emission of loop XII with a large patch of soft X-ray emission found with SRG/ in excess of the background surface brightness in the same region. This seemingly coherent patch of soft X-ray emission, which we call the extends over a remarkable area of $ 1000$ deg$^2$ and includes an arc-shaped enhancement that might trace a cold front. An anticorrelation of the X-ray intensity with the temperature of the plasma that causes the X-ray emission is also observed. The X-ray bright arc seems to anticipate radio loop XII by some degrees on the sky. This behavior can be recast in terms of a correlation between X-ray surface brightness and radio depolarization. We explore and discuss different possible scenarios for the source of the diffuse emission in the Goat Horn complex: a large supernova remnant, an outflow from active star-forming regions in nearby Galactic spiral arms, and a hot atmosphere around the Large Magellanic Cloud. In order to probe these scenarios further, a more detailed characterization of the velocity of the hot gas is required.

Mineralogy and mineral chemistry of Bi-Te minerals: Constraints on mineralization process of the Dulanggou gold deposit, Dadu River Metallogenic Belt, China

There is a widely recognized association of bismuth (Bi)-tellurium (Te) minerals with gold in many hydrothermal gold deposits. However, the specific process for gold enrichment related to Bi-Te minerals remains enigmatic. The Dulanggou gold deposit, located on the southeastern margin of the Songpan-Garzê orogenic belt, China, provides an opportunity to research this process. Gold in the deposit is mainly associated with coarse-grained Bi-Te minerals and bismuth-rich polyphase metal droplets. Three mineralization stages are identified in the deposit. In Stage 1, a small amount of gold was deposited within dominate pyrrhotite. In Stage 2, a large amount of visible gold grains were precipitated with coarse-grained Bi-Te minerals. The various Bi-Te phases are mainly tsumoite, pilsenite, unnamed minerals (Bi3Te2, Bi2Te), joséite-B and trace hedleyite, which have a common characteristics of 2 ≥ Bi/Te > 1. In stage 3, around the Stage 2 large Bi-Te phase patches, bismuth-rich polyphase metal droplets pervasively occurred with Bi/Te ≥ 2. Other Bi-Te minerals in Stage 3 include hedleyite, unnamed minerals (Bi3Te, Bi8Te3, Bi5Te), joséite-B, and joséite-A, all intergrowth with gold and maldonite in the metal droplets. Mineral chemistry and phase diagrams of the Bi-Te mineral assemblages indicate that the mineralization temperatures at Stages 2 and 3 are > 325 ℃ and around 235 ℃ respectively, and the fTe2 and fS2 gradually decrease from Stage 2 to Stage 3. Importantly, a large amount of native gold was deposited with native Bi during Stage 3 and Bi contents in Bi-Te minerals increase with gold fineness from 799 ∼ 876 at Stage 2 to 833 ∼ 939 at Stage 3. These indicate that the metal droplets could be Bi-rich melts which were separated from Bi-Te phase patches and scavenged gold from earlier mineral assemblages to enhance gold enrichment.

Contributions of microlayer to flow boiling heat transfer in the mini-channel

Flow boiling stands out as an efficient mode of heat transfer with significant potential for reducing carbon footprint. Based on a coupled Volume-of-Fluid and Level Set (VOSET) method, this numerical study reveals the microlayer and its evaporative heat flux distributions, as well as the effects of microlayer evaporation and depletion on bubble dynamic behavior, flow pattern, wall superheat distribution, and boiling crisis for the flow boiling in a mini-channel. These aspects are firstly comprehensively reported by the numerical method. Results indicate that the rapid evaporation of a thin microlayer positioned beneath elongated bubbles significantly contributes to heat dissipation during flow boiling in a mini-channel. The heat flux through the microlayer surpasses 300 kW/m2, accounting for approximately 42% of heat dissipation at 200 kW/m2. Furthermore, this contribution increases to over 70% as the heat flux exceeds 500 kW/m2. As a result, in comparison to scenarios without microlayers, the presence of microlayers results in an average heat transfer coefficient (HTC) that is 3.97 times larger within the range of 200–500 kW/m2. Additionally, microlayer evaporation delays the happening of flow boiling crisis. Without microlayers, the wall superheat exceeds 180 K at 500 kW/m2, whereas under microlayer influence, the maximum local wall superheat is only 37.09 K at 1000 kW/m2. With further increases in heat flux, the emergence of large dry patches resulting from microlayer depletion induces the beginning of heat transfer deterioration. Finally, the ongoing coalescence of elongated bubbles necessitates a prolonged period for rewetting dry patches at the exit of the mini-channel, triggering the flow boiling crisis at 1300 kW/m2. The study results provide crucial guidance for the development and application of the flow boiling heat transfer technology for the thermal management of data centers.

Stakeholder perceptions in mangrove management in the Jaffna Peninsula, Sri Lanka

Mangroves are recognised as social-ecological systems where ecological dimensions constantly interact with human dimensions. In the Jaffna Peninsula of Sri Lanka, mangroves constitute the primary forest type. However, a destructive civil war spanning over 25 years, heavily affected the local vegetation and local inhabitants. Large patches of mangrove forests were damaged and remained inaccessible for a considerable time, compelling most of the population to temporarily abandon their land. This study aimed to investigate the main mangrove goods and services that the local population benefits from and gather opinions of mangrove management stakeholders regarding mangrove conservation in the Jaffna Peninsula through a mixed methods approach. Ethnobiological surveys were conducted with coastal communities, along with Q methodology, expert opinion surveys and additional semi-structured interviews with mangrove management stakeholders. Ethnobiological surveys revealed a significant distancing of local communities from mangrove goods and services. The Q methodology identified three discourses: community-oriented, government-oriented, and mangrove conservation oriented. Expert opinion surveys highlighted encroachment and pollution as major threats to mangroves. Issues raised in the semi structured interviews include challenges regarding land ownership permits during and after the war, weak interactions among different stakeholders with overlapping jurisdiction, failed replantation efforts and scarcity of scientific data for mangrove management. Addressing these issues is crucial not only for fostering effective mangrove management and conservation in the Jaffna Peninsula but also for potentially benefiting other districts in Sri Lanka and beyond.

Structural basis for the intracellular regulation of ferritin degradation

The interaction between nuclear receptor coactivator 4 (NCOA4) and the iron storage protein ferritin is a crucial component of cellular iron homeostasis. The binding of NCOA4 to the FTH1 subunits of ferritin initiates ferritinophagy—a ferritin-specific autophagic pathway leading to the release of the iron stored inside ferritin. The dysregulation of NCOA4 is associated with several diseases, including neurodegenerative disorders and cancer, highlighting the NCOA4-ferritin interface as a prime target for drug development. Here, we present the cryo-EM structure of the NCOA4-FTH1 interface, resolving 16 amino acids of NCOA4 that are crucial for the interaction. The characterization of mutants, designed to modulate the NCOA4–FTH1 interaction, is used to validate the significance of the different features of the binding site. Our results explain the role of the large solvent-exposed hydrophobic patch found on the surface of FTH1 and pave the way for the rational development of ferritinophagy modulators.

First Report of Powdery Mildew on Quercus fabri and Q. robur Caused by Erysiphe quercicola in China.

Quercus (Fagaceae) is a genus of ecologically and economically important shrub and tree species (Yin et al. 2018). In April 2022, powdery mildew symptoms were observed on Quercus fabri and Quercus robur leaves on Longwen hill, Guizhou Normal University, Guiyang, China. The incidence was 30% (Q. fabri, n = 50) and 20% (Q. robur, n = 30), respectively. Powdery mildew fungi from these two Quercus species shared similar morphological characteristics. Mycelia occurred on adaxial and abaxial leaf surfaces, forming small to large patches; hyphae were hyaline, 3-7 µm wide; hyphal appressoria were lobed to multilobed, solitary; conidiophores were erect, straight, 36-80 µm long (n = 30); foot cells were followed by 1-2 shorter cells; conidia formed singly, obovoid to ellipsoid, 24-38 × 12-27 µm (n = 50), without fibrosin bodies; no chasmothecia were observed. Based on these characteristics, powdery mildew fungi on both Q. fabri and Q. robur were identified as Erysiphe quercicola (Takamatsu et al. 2007). To confirm the identification, ribosomal DNA internal transcribed spacer (ITS) sequences of two fungal samples from Q. fabri and Q. robur were separately amplified and sequenced using primer pair ITS1/ITS4 (White et al. 1990). The obtained ITS sequences (GenBank accession nos. QR414372 and QR414373, respectively) shared 100% identity, and 99.38-99.84% identity with diverse ITS sequences of E. quercicola (Takamatsu et al. 2015). In a phylogenetic tree based on ITS sequences of Erysiphe species (Takamatsu et al. 2007), QR414372 and QR414373 were grouped in a clade with ITS sequences of E. quercicola. To fulfil Koch's postulates, leaves of three healthy potted Q. fabri plants and three healthy potted Q. robur plants were inoculated by gently pressing diseased Q. fabri and Q. robur leaves onto healthy leaves. Non-inoculated healthy Q. fabri and Q. robur plants served as controls. All plants were incubated in a greenhouse at 25 ± 2°C with 80% relative humidity. Typical powdery mildew symptoms were observed on all inoculated plants 15 days after inoculation, whereas no symptoms were observed on control plants. Fungi separately reisolated from inoculated Q. fabri and Q. robur were morphologically identical to those on their originally diseased plants, and ITS sequences of reisolated fungi shared 100% identity with QR414372 and QR414373. E. quercicola has previously been reported to infect Quercus species, including Q. robur in Australia, Q. crispula, Q. phillyraeoides and Q. serrata in Japan, and Q. phillyraeoides in Korea (Lee et al. 2011). In China, Q. fabri and Q. robur may be infected by E. alphitoides and E. hypophylla, respectively (Zheng et al. 1987). To our knowledge, this is the first report of powdery mildew caused by E. quercicola on Q. fabri and Q. robur in China. This work provides a foundation to protect Quercus plants against this fungal pathogen.

Trophic position determines the persistence of neotropical understory birds after forest disturbance.

Habitat loss and degradation are key drivers of the current biodiversity crisis. Most research focuses on the question of which traits allow species to persist in degraded habitats. We asked whether a species' trophic position or niche width influences the resilience of species in degraded habitats and to what extent habitat degradation affects trophic interactions between species. We used nitrogen isotope ratios (15N:14N, expressed as δ15N value) to quantify and compare trophic positions and niche widths of understory birds inhabiting old-growth and young secondary forests in the Pacific lowlands of Costa Rica. We found that a species' trophic position rather than its trophic niche width determined its persistence in secondary forests. Species feeding at lower trophic levels in old-growth forests were less likely to persist in secondary forests than those occupying a higher trophic position in old-growth forests. This pattern is likely induced by the occurrence of relatively large-bodied habitat specialists with a flexible and high-trophic level diet in secondary forests. These habitat specialists likely caused generalist bird species to lower their trophic position relative to conspecifics in old-growth forests. Regarding trophic niche widths, species in secondary forests tend to have larger niche widths than old-growth forest species. However, as old-growth forest specialists and generalists did not differ in their niche widths, no systematic effect of trophic niche width on species persistence after forest disturbance was found. This is the first study that shows a systematic effect of trophic position on the persistence of a wide range of bird species in a disturbed forest ecosystem. It therefore provides important insights into species' responses to habitat degradation and the conservation value of secondary forests. To improve habitat quality for old-growth forest birds and facilitate avian seed dispersal, the creation of large contiguous forest patches should be prioritised when implementing reforestation measures.

Soil geochemistry and constraint of tree seedlings immediately after germination on Macrotermes termite mounds in the Kruger National Park, South Africa.

Macrotermes termite mounds in the Kruger National Park occupy a significant part of the savanna landscapes, occurring at densities of up to 70 km-2 and often exceeding 10 m in width and 4 m in height. The mounds are usually devoid of trees, but have dense grass cover in wet years. As a result, these mounds form large patches of grassland amongst the wooded savanna. To our knowledge, it is not known why trees are largely excluded from the mounds. We analysed soil surface nutrient concentrations on and off mounds (0-2 cm deep, n = 80) to ascertain whether the availability of nutrients could be influencing competition between grasses and tree seedlings. The results showed that potential deficiencies in P, Ca, Cu, Zn and B in soils off the mounds are likely to be constraining plant growth. Notably, only B, with an average concentration of 0.19 mg kg-1, was likely to be limiting plant growth on the mounds. Notwithstanding likely interactions with herbivory and fire, we hypothesise that because grasses are far less susceptible to deficiencies of B than dicotyledonous trees, it is likely that grass competition with tree seedlings is considerably greater on mounds than off mounds.

Acetylcholinesterase is regulated by exposure of ultraviolet B in skin keratinocytes: A potential inducer of cholinergic urticaria.

Cholinergic urticaria is a dermatological disease characterized by the presence of large patches of red skin and transient hives triggered by factors, such as exercise, sweating, and psychological tension. This skin problem is hypothesized to be attributed to a reduced expression of acetylcholinesterase (AChE), an enzyme responsible for hydrolyzing acetylcholine (ACh). Consequently, ACh is thought to the leak from sympathetic nerves to skin epidermis. The redundant ACh stimulates the mast cells to release histamine, triggering immune responses in skin. Here, the exposure of ultraviolet B in skin suppressed the expression of AChE in keratinocytes, both in invivo and invitro models. The decrease of the enzyme was resulted from a declined transcription of ACHE gene mediated by micro-RNAs, that is, miR-132 and miR-212. The levels of miR-132 and miR-212 were markedly induced by exposure to ultraviolet B, which subsequently suppressed the transcriptional rate of ACHE. In the presence of low level of AChE, the overflow ACh caused the pro-inflammatory responses in skin epidermis, including increased secretion of cytokines and COX-2. These findings suggest that ultraviolet B exposure is one of the factors contributing to cholinergic urticaria in skin.

The Gould’s Toucanet Selenidera gouldii (Natterer, 1837) (Aves: Ramphastidae) as a monotypic species

The Gould’s Toucanet Selenidera gouldii (Natterer, 1837) occurs mainly in eastern Amazonia, with a geographically isolated population in the northeast Brazilian state of Ceará. Based on two male specimens from the latter population that appeared to have a smaller body and bill with a relatively large black patch, Pinto & Camargo (1961) described the subspecies S. g. baturitensis. This taxon has long been known in museum collections only by the two male specimens mentioned in its description, but recently obtained specimens have now permitted a test of its validity with larger sample sizes. Here, I examined the largest sample of S. g. baturitensis studied to date to show that S. g. gouldii and S. g. baturitensis are just the east and west ends of a broad geographic pattern of smoothly clinal differences in morphometrics that were categorized as subspecies taxa.

Alcon Blues: recent shifts in limiting habitat factors challenge the persistence of an endangered butterfly

Insect habitat specialists have declined more than generalists over the last decades. Understanding how habitat requirements and increased climate variability interact to explain persistence of populations is needed to enable effective conservation measures. Habitat specialists with a complex life cycle, such as myrmecophilous butterflies, are likely to be most vulnerable. Here, we explored to what extent the habitat factors explaining population persistence of the Alcon blue (Phengaris alcon), changed over a 25-year period in the Netherlands, contrasting the recent years 2018–2022 with extreme droughts with the preceding period 1998–2017 characterized by occasional climatic extremes. Population persistence of P. alcon over 1998–2017 as explained by historical habitat conditions was significantly higher in large heathland areas with large patches of its host plant Gentiana pneumonanthe. On the basis of current conditions, population persistence until 2017 was best explained by a combination of host plant area and quality. In contrast, persistence over the recent drought years was most closely associated with increasing occupancy of the optimal host ant Myrmica ruginodis and lower occupancy of competitive and predatory Lasius ants.Implications for insect conservation We conclude that critical habitat conditions change under increasing climatic extremes and that the availability of sufficient optimal host ants has become more critical than that of host plants. The results emphasise that both large-scale hydrological restoration and small-scale management for heterogeneity are necessary to preserve P. alcon and its habitat in the Netherlands. This is also likely to apply to other habitat specialists with complex life cycles from threatened habitats.

Treatment of Aorto-iliac and Infrainguinal Vascular Infections with a Prefabricated Bovine Pericardial Graft

The use of biological grafts provides acceptable mid- and long-term results in native or prosthetic vascular infections. Several reports describe the successful use of bovine pericardium in case of vascular infections, mainly as a large patch to be sutured as a tubular graft. Recently, a novel prefabricated bovine pericardium graft (Biointegral Surgical No-React® Inc, Mississauga, ON, Canada) has been introduced in clinical practice with promising results. In this study, we report our preliminary experience utilizing Biointegral Surgical graft in case of native and or prosthetic aorto-iliac and infrainguinal infection. We retrospectively analyzed data from 20 patients with native or prosthetic aorto-iliac and infrainguinal infection who underwent in situ reconstruction (ISR) with a Biointegral Surgical No-React bovine pericardium prosthesis between October 2020 and February 2023 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario Gemelli - IRCCS in Rome, Italy. All patients followed a standardized protocol including postoperative anticoagulation and long-term intravenous antibiotics. The indication for surgery was: mycotic aortic aneurysm in 4 patients (20%), graft infection after abdominal aortic repair in 11 patients (55%), peripheral graft infection in 5 patients (25%). Complete excision of the infected aorta or prosthetic graft, surgical debridement and ISR were performed in all patients. Hospital mortality rate was 5% (n=1) and graft-related mortality of 0%. During follow-up (median 13months, range 6-34months), reinfection was 5.2% and primary graft patency 94.7%. The use of prefabricated bovine pericardial grafts represents a promising option for the treatment of native and prosthetic aorto-iliac and infrainguinal infections. The application of this biological graft with a standardized postoperative protocol has been associated with a satisfactory patency and reinfection rate without increased bleeding complications.

ProLiF: Progressively-connected Light Field network for efficient view synthesis

This paper presents a simple yet practical network architecture, ProLiF (Progressively-connected Light Field network), for the efficient differentiable view synthesis of complex forward-facing scenes in both the training and inference stages. The progress of view synthesis has advanced significantly due to the recent Neural Radiance Fields (NeRF). However, when training a NeRF, hundreds of network evaluations are required to synthesize a single pixel color, which is highly consuming of device memory and time. This issue prevents the differentiable rendering of a large patch of pixels in the training stage for semantic-level supervision, which is critical for many practical applications such as robust scene fitting, style transferring, and adversarial training. On the contrary, our proposed simple architecture ProLiF, encodes a two-plane light field, which allows rendering a large batch of rays in one training step for image- or patch-level losses. To keep the multi-view 3D consistency of the neural light field, we propose a progressive training strategy with novel regularization losses. We demonstrate that ProLiF has good compatibility with LPIPS loss to achieve robustness to varying light conditions, and NNFM loss as well as CLIP loss to edit the rendering style of the scene.

Mapping the way: identifying priority potential corridors for protected areas connectivity in Colombia

Colombia has experienced alarming rates of deforestation, posing a threat to forest biodiversity both inside and outside protected areas. Furthermore, a decline in ecological connectivity can potentially disrupt vital ecological processes such as pollination, gene flow, breeding, seed dispersal, among others. To address this issue at a national scale, it is crucial to identify and conserve a comprehensive network of ecological corridors.In this study, we identified high priority potential ecological corridors linking protected areas in Colombia. We categorized a representative set of 16 threatened mammal species into four ecological profiles. Then, we used Least Cost Path (LCP) analysis to model potential corridors between protected areas as those that minimized resistance for forest species dispersal. To prioritize conservation efforts, we applied the decrease in the Probability of Connectivity index (dPC) to identify corridors with the highest priority.Our findings emphasize the importance of preserving large forest patches within protected areas for species inhabiting lowland and sub-Andean forests. However, for species residing in Andean and high Andean forests, restoration measures (e.g., increasing forest cover) between protected areas are needed to enhance landscape permeability and facilitate their dispersal, thereby contributing to their conservation.Our results have practical implications for decision-makers involved in conservation efforts. These findings can aid in identifying conservation priorities for existing protected areas and their surrounding forest habitats in Colombia. Additionally, we provided expert-based resistance values for different forest mammals that can be further used in other large scale connectivity analyses, including other countries where these species inhabit.

Suitability assessment for forest landscape restoration based on species diversity conservation

Forest landscape fragmentation poses a significant challenge to the conservation of species diversity. Evaluating the suitability of forest landscape restoration (FLR) becomes essential as it promotes effective management of forest resources and protects species diversity. This study focused on deploying and testing a suitability evaluation framework system for FLR in the Saihanba area of Hebei, China. The framework system incorporated factors such as land cover type, landscape structure, soil quality, and topography. Using the matter-element model, the study evaluated the restoration suitability and identified priority restoration areas. The results revealed that land cover type and landscape structure were the primary factors influencing FLR in the study area. The suitable area for FLR in the study area was about 519.20 km2, accounting for 55.55% of the total area. The area of moderate, marginal, and unsuitable restoration accounted for 17.30%, 23.96%, and 3.18% of the study area, respectively. The suitable restoration areas predominantly consisted of natural secondary forest characterized by large patch areas, short distances between patches, and complex patch shapes. In the study area, the objective of FLR should be protect large and complex shaped patches of natural secondary forests for better conservation of species diversity. The FLR suitability evaluation conducted in this study provide a valuable guidance for promoting species-diversity conservation and restoration of forest ecosystems at the landscape scale in the study area and other similar regions.

Impacts of the attributes of patches and the surrounding matrix on the phylogenetic diversity of tree species in urban remnant forests

AbstractUrbanization is a major cause of biotic homogenization and evolutionary poverty. Urban remnant forests are biodiversity hotspots in cities but are prone to phylogenetic homogenization. However, how urbanization‐driven changes in patch attributes and landscape heterogeneity levels of the surrounding matrix affect plant phylogenetic diversity in urban remnant forests remains unclear. We quantified tree phylogenetic diversity and structure in 30 remnant forest patches in Guiyang, China, using chloroplast genome data and analyzed the effects of patch attributes and the surrounding matrix on tree phylogenetic diversity and structure in the forests while considering tree species stage. The phylogenetic diversity of saplings/seedlings was lower than that of adult trees. Small patches contributed more than large patches to the overall phylogenetic diversity of remnant forest ecosystems. Additionally, tree phylogenetic diversity was positively associated with configurational heterogeneity of the surrounding matrix, while phylogenetic diversity and relatedness were negatively related to the percentage of surrounding impervious surfaces and patch size. Accordingly, we suggest maintaining configurational heterogeneity and controlling the speed of urban expansion in the surrounding matrix to better conserve urban remnant forests. Furthermore, the preservation of small forest remnants and tree species in the sapling/seedling stage should be prioritized.

The relative contributions of habitat area, configuration, and vegetative diversity on snake and lizard presence in agricultural landscapes

AbstractNearly one in five reptile species is at risk of extinction. Changes in habitat area, its configuration, and vegetation diversity could affect habitat use, but their relative importance is understudied. We assessed how these factors affected reptile presence in agricultural landscapes figure in Iowa, United States, using 695 cover boards visited 16,441 times in 2015–2020. Species‐wise encounter rates ranged 0.0001–0.012. Eight of 11 species and 54.2% of individuals were species of greatest conservation need. Habitat area, configuration, and vegetation diversity influenced reptile presence similarly. Mean patch occupancy was 0.18 for common garter snake (CG, Thamnophis sirtalis) and 0.45 for all snakes (AS). Naïve presence was explained by effort (odds ratio [OR]AS = 1.83, ORCG = 1.79), vegetation diversity (ORAS = 1.28, ORCG = 1.28), woody cover (ORAS = 1.24, ORCG = 1.41), and patch size (ORAS = 1.30). Large patch prairies were more likely to contain snakes than other conservation practices (encounter = 0.291), and more likely to contain CG (0.098) than prairie contour strips (0.031), waterways (0.018), grass contour strips (0.016), or terraces (0.015). While we documented low overall reptile presence, their higher presence in large prairie patches underscores the importance of core nature reserves for reptile conservation.

A generic algorithm to automatically classify urban fabric according to the local climate zone system: implementation in GeoClimate 0.0.1 and application to French cities

Abstract. Geographical features may have a considerable effect on local climate. The local climate zone (LCZ) system proposed by Stewart and Oke (2012) is nowadays seen as a standard approach for classifying any zone according to a set of urban canopy parameters. While many methods already exist to map the LCZ, only few tools are openly and freely available. This paper presents the algorithm implemented in the GeoClimate software to identify the LCZ of any place in the world based on vector data. Six types of information are needed as input: the building footprint, road and rail networks, water, vegetation, and impervious surfaces. First, the territory is partitioned into reference spatial units (RSUs) using the road and rail network, as well as the boundaries of large vegetation and water patches. Then 14 urban canopy parameters are calculated for each RSU. Their values are used to classify each unit to a given LCZ type according to a set of rules. GeoClimate can automatically prepare the inputs and calculate the LCZ for two datasets, namely OpenStreetMap (OSM, available worldwide) and the BD TOPO® v2.2 (BDT, a French dataset produced by the national mapping agency). The LCZ are calculated for 22 French communes using these two datasets in order to evaluate the effect of the dataset on the results. About 55 % of all areas have obtained the same LCZ type, with large differences when differentiating this result by city (from 30 % to 82 %). The agreement is good for large patches of forest and water, as well as for compact mid-rise and open low-rise LCZ types. It is lower for open mid-rise and open high-rise, mainly due to the height underestimation of OSM buildings located in open areas. Through its simplicity of use, GeoClimate has great potential for new collaboration in the LCZ field. The software (and its source code) used to produce the LCZ data is freely available at https://doi.org/10.5281/zenodo.6372337 (Bocher et al., 2022); the scripts and data used for the purpose of this article can be freely accessed at https://doi.org/10.5281/zenodo.7687911 (Bernard et al., 2023) and are based on the R package available at https://doi.org/10.5281/zenodo.7646866 (Gousseff, 2023).

Variational Monte Carlo with large patched transformers

Large language models, like transformers, have recently demonstrated immense powers in text and image generation. This success is driven by the ability to capture long-range correlations between elements in a sequence. The same feature makes the transformer a powerful wavefunction ansatz that addresses the challenge of describing correlations in simulations of qubit systems. Here we consider two-dimensional Rydberg atom arrays to demonstrate that transformers reach higher accuracies than conventional recurrent neural networks for variational ground state searches. We further introduce large, patched transformer models, which consider a sequence of large atom patches, and show that this architecture significantly accelerates the simulations. The proposed architectures reconstruct ground states with accuracies beyond state-of-the-art quantum Monte Carlo methods, allowing for the study of large Rydberg systems in different phases of matter and at phase transitions. Our high-accuracy ground state representations at reasonable computational costs promise new insights into general large-scale quantum many-body systems.

Increased unpredictability in spruce budworm outbreaks following habitat loss and landscape fragmentation

The spruce budworm (SBW) is the insect defoliator responsible for the greatest tree mortality in North America. Fragmentation and loss of habitat are expected to affect the movement of SBW through forested landscapes during periods of dispersal thereby modifying outbreak severity and frequency.We developed a spatially explicit tri-trophic model by combining a forest landscape model and a system of difference equations to evaluate how the interactions between the SBW, its hosts and its parasitoids are disrupted by habitat loss and fragmentation. We designed landscapes with varying quantities of habitat and fragmentation levels to measure their influence on population dynamics and outbreak severity and frequency.Our model simulations show that landscapes with higher proportion of host tree habitat were also characterised by greater SBW average densities, average cumulative defoliation and outbreak severity, which agrees with earlier studies. However, the bottom-up control by tree hosts breaks down as their proportion in the landscape decreased or when they formed isolated patches. Indeed, we found that landscapes with a low proportion of habitat fragmented into relatively large distant patches produced greatest variability in average SBW abundance and cumulative defoliation between simulation runs. In landscapes with higher habitat proportion, increased isolation between patches produced asynchronous outbreaks. Moreover, in these landscapes, parasitoids occupy fewer habitat cells than the SBW, suggesting that they were not able to efficiently track their prey. Together, these results indicate that increased distance between habitat patches can disrupt trophic control of SBW leading to increased unpredictability and asynchrony in outbreak dynamics.For continued effective management of SBW using current deterministic decision-making tools, we recommend prioritising the maintenance of habitat connectivity in forested landscapes.