Unmodified Areas Research Articles

Attention-guided siamese networks for change detection in high resolution remote sensing images

Understanding surface changes requires the ability to identify changes in high resolution remote sensing images. Because current deep learning-based change detection algorithms are not able to accurately discriminate between altered and unmodified areas, which leads to the problem of edge uncertainty and small target missing in the detection process. To identify changes in high resolution remote sensing images, this research proposes an unique Attention-Guided Siamese Network (SAGNet). In this network, bitemporal images’ highly representative deep semantic features are retrieved using a fully convolutional dual-stream architecture, and the extracted deep semantic features are then used to extract semantic variation data from the Global Semantic Aggregation Module (GSAM). In the feature decoding stage, the extracted features are refined layer by layer through the Attention Fusion Module (AFM) for change map reconstruction. In addition, we propose two other auxiliary modules: Cross-scale Fusion Module (CFM) and Bilateral Feature Fusion Module (BFFM), which enable the network to remove background noise while improving the recognition accuracy of changing object boundaries and small-changing targets in the output change map. A public dataset called LEVIR-CD and a challenging dataset called BICD made up of bitemporal images from Google Earth covering various parts of China are used to experimentally test SAGNet. Finally, experimental evidence shows that our approach outperforms current cutting-edge change detection techniques.

Alleviating soil degradation caused by green bean continuous cropping: application of combined amendments

Context Management practices of conventional cropping that includes intense monoculture has led to soil health problems, such as deterioration of soil fertility and soil microbial diversity, leading to the proliferation of soil-borne diseases. Soil amendments using organic materials, calcium and disinfecting agents may be important management tools to promote healthier soils. Aims To determine the effects of combined soil improving amendments to mitigate problems associated with continuous cropping of green bean. Methods Soil samples were collected from the modified areas (SF) of combined application of organic amendments (biofertiliser, humic acid material), calcium amendments (lime, calcium magnesium compound fertiliser) and disinfection materials (carbendazim) and unmodified areas (CK) to compare the effects of chemical characteristics, allelochemicals and microbial community in soil under different soil modifications. Key results Results showed that combined modification could significantly increase soil pH, organic matter (SOM), available nutrients (N, P, and K), and decrease the contents of phenolic acids allelochemicals in soil. However, l-epicatechin increased. The combined modification could increase the relative abundance of beneficial bacteria such as Actinobacteria, Nocardioides and Streptomyces, and decrease the relative abundance of microorganisms such as Betaproteobacteria, Acidobacteria and Deltaproteobacteria that can cause soil-borne diseases. Conclusions Biological mechanism mapping showed that the application of combined amendments could effectively alleviate soil fertility problems associated with long-term cultivation of green bean. Implications The combined application of organic amendments, calcium amendments and disinfection materials can modify soil to promote the healthier agricultural soils in long-term vegetable growing areas.

SeparaFill: Two generators connected mural image restoration based on generative adversarial network with skip connect

Mural is an important component of culture and art of Dunhuang in China. Unfortunately, these murals had been ruined or are being ruined by some diseases such as cracking, hollowing, falling off, mildew, dirt, and so on. Existing image restoration algorithms have problems such as incomplete repair and disharmonious texture during large-area repair, so the effect of mural image disease area repair is poor. Due to lack of a standard mural datasets, Dunhuang mural datasets are created in the paper. Meanwhile, our network architecture SeparaFill is proposed which connects two generators based on U-Net. Based on the characteristics of the painting, the contour line pixel area of the mural image is innovatively separated from the content pixel area. Firstly, the contour restoration generator network with skip connect and hierarchical residual blocks is employed to repair contour lines. Then, the color mural image is repaired by the content completion network with guide of the repaired contour. Full resolution branches and generator branches of the U type are exploited in content completion generators. Convolution layers of different kernel sizes are fused to improve the reusability of the underlying features. Finally, global and local discriminant networks are applied to determine whether the repaired mural image is authentic in terms of both the modified and unmodified areas. The proposed SeparaFill shows good performance in restoring the line structure of the damaged mural images and retaining the contour information of the mural images. Compared with existing restoration algorithms in mural real damage repair experiment, our algorithm increases the peak signal-to-noise ratio (PSNR) by an average of 1.1–4.3 dB and the structural similarity (SSIM) values were slightly improved. Experimental results reveal the good performance of the proposed model, which can contribute to digital restorations of ancient murals.

A Statistical Modeling Framework for DCT Coefficients of Tampered JPEG Images and Forgery Localization

Various manipulations on JPEG images introduce single and multiple compression artifacts for forged and unmodified areas respectively. Based on the statistical analysis of JPEG compression cycle and on the finite mixture paradigm, we propose in this paper a modeling framework for AC DCT coefficients of such tampered JPEG images. Its accuracy is numerically assessed using the Kullback-Leibler divergence on the basis of a tampered JPEG image dataset built from six well-known uncompressed color image databases. To illustrate the framework utility, an application in image forgery localization is proposed. By formulating the localization as a clustering problem, we use the plug-in Bayes rule combined with a simple EM algorithm to distinguish between forged and unmodified areas. Numerous experiments show that, when the quality factor of final JPEG compression is high enough, the proposed modeling framework yields higher localization performances in terms of <i>F</i>₁-score than prior art regardless of divers local manipulations.

Investigation of the influence of the ion-beam treatment dose of the Si(111) surface on the GaAs nanowires growth processes

This paper presents the results of experimental studies of the effect of the Ga ion dose during ion-beam treatment of the Si(111) surface using the focused ion beam technique on the Ga+ nanowires epitaxial growth processes. A significant difference is revealed between the parameters of nanowire arrays formed on modified and unmodified areas of the Si substrate in this way. It is shown that changing the Ga ions dose from 0.052 to 10.4 pC/μm2 during ion-beam treatment makes it possible to form GaAs nanowires arrays with a different set of parameters in a single technological cycle with a high degree of localization. The regularities of the influence of the dose of Ga ions during surface modification on the key characteristics of GaAs nanowires (density, diameter, length, and orientation with respect to the substrate surface) are experimentally established. Keywords: Focused ion beam, nanowires, GaAs, molecular beam epitaxy.

Исследование влияния дозы ионно-лучевой обработки поверхности Si(111) на процессы роста нитевидных нанокристаллов GaAs

This paper presents the results of experimental studies of the effect of the Ga ion dose during ion-beam treatment of the Si(111) surface using the focused ion beam technique on the GaAs nanowires epitaxial growth processes. A significant difference is revealed between the parameters of nanowire arrays formed on modified and unmodified areas of the Si substrate in this way. It is shown that changing the Ga ions dose from 0.052 to 10.4 pC/μm^2 during ion-beam treatment makes it possible to form GaAs nanowires arrays with a different set of parameters in a single technological cycle with a high degree of localization. The regularities of the influence of the dose of Ga ions during surface modification on the key characteristics of GaAs nanowires (density, diameter, length, and orientation with respect to the substrate surface) are experimentally established.

Does construction in the spawning ground improve the riverbed conditions making it suitable for spawning of the Ryukyu-ayu Plecoglossus altivelis ryukyuensis?

Maintaining a certain number of spawning grounds for endangered fish is particularly important in rivers and streams where the environment changes drastically through floods and exploitations. Ryukyu-ayu Plecoglossus altivelis ryukyuensis is an endangered annual fish inhabiting the few streams and rivers flowing through the Amami-Oshima Island, southern Japan, and spawns in the lower reaches at sites with the specific riverbed conditions. In the island, resident volunteers along with researchers modify riverbed manually to provide conditions suitable for the natural spawning of the fish every year. This study investigated the effects of these activities on the riverbed conditions and consequently on the spawning by Ryukyu-ayu in two rivers. Our results showed that riverbed hardness and the amount of silt significantly decreased in the modified areas, but not in the adjacent unmodified areas. In one of the two rivers, the modification suppressed the settlement of net-spinning caddisfly larvae Stenopsyche schmidi that promote consolidation of the riverbed. The riverbed conditions in the modified areas were similar to those in the sites where P. a. ryukyuensis indeed spawned. These results suggest that manual modification is efficient in improving riverbed conditions for the spawning of Ryukyu-ayu. However, the eggs of the fish were not found at the modified areas in both rivers. It will be necessary to develop effective and practical ways of selecting sites for modification without obstructing the natural spawning in this fish.

Ancient mural restoration based on a modified generative adversarial network

How to effectively protect ancient murals has become an urgent and important problem. Digital image processing developments have made it possible to repair damaged murals to a certain extent. This study proposes a consistency-enhanced generative adversarial network (GAN) model to repair missing mural areas. First, the convolutional layer from a fully convolutional network (FCN) is used to extract deep image features; then, through deconvolution, the features are mapped to the size of the original image and the repaired image is output, thereby completing the regenerative network. Next, global and local discriminant networks are applied to determine whether the repaired mural image is “authentic” in terms of both the modified and unmodified areas. In adversarial learning, the generative and discriminant network models are optimized to better complete the mural repair. The network introduces a dilated convolution that increases the convolution kernel’s receptive field. Each network convolutional layer joins in the batch standardization (BN) process to accelerate network convergence and increase the number of network layers and adopts a residual module to avoid the vanishing gradient problem and further optimizing the network. Compared with existing mural restoration algorithms, the proposed algorithm increases the peak signal-to-noise ratio (PSNR) by an average of 6–8 dB and increases the structural similarity (SSIM) index by 0.08–0.12. From a visual perspective, this algorithm successfully complements mural images with complex textures and large missing areas; thus, it may contribute to digital restorations of ancient murals.

Infaunal community responses to ancient clam gardens

AbstractAquatic ecosystems have been managed for millennia. Indigenous communities in North America pioneered numerous marine resource management strategies to ensure food security and support thriving economies, which have been active throughout the Northwest Coast of North America for over 14 000 years. Developed to increase shellfish productivity, clam gardens have been active for millennia. The diverse infaunal communities within these ecosystems can act as indicators of habitat alterations and provide an opportunity to study ecological community responses to seascapes shaped by millennia-old resource management structures. To determine how community structure differs between clam gardens and unmodified areas, we assessed infaunal diversity and density between intertidal mudflats, sandflats, and clam gardens. Differences in community composition were found among site types, with certain taxa, including culturally important species increasing within clam gardens. Per cent similarity analyses indicated that infaunal communities were more dissimilar among, than within site types. Furthermore, regression trees indicated that increases in diversity and density were closely correlated with the amount of shell and gravel within each habitat, which are associated with clam garden function and management practices. Species-specific and environmental responses to clam gardens indicate that human modifications in nearshore habitats created novel and distinct types of soft sediment communities.

Local hydrogel fabrication based on electrodeposition with a large-scale integration (LSI)-based amperometric device

Addressable electrode arrays are widely used in a number of applications, such as electrochemical imaging and high-throughput assays. Recently, large-scale integration (LSI) technologies have been used to prepare electrochemical devices containing signal amplifiers and switching elements, such that multiple highly sensitive sensors can be incorporated into these devices. Because these devices induce chemical reactions at the target electrodes, biomaterials such as hydrogels can be electrochemically fabricated. In this study, we present a new biofabrication strategy using the electrochemical device. We used an LSI device to locally electrodeposit chitosan hydrogels at the target electrodes, with the goal of fabricating the designed hydrogels. The hydrogels were fabricated via the generation of Cl2 at the anodes where a potential of 0.95 V was applied. The biofabrication method was utilized for three bioapplications. First, three-dimensionally designed chitosan hydrogels, for example apple-shaped and layered hydrogels were fabricated on this device by electrodepositing them for 10–30 s. In order to demonstrate biosensing, glucose oxidase and horseradish peroxidase were modified at the target electrodes through hydrogel electrodeposition; consequently, droplets containing glucose and H2O2 were electrochemically imaged at the same time using the electrochemicolor imaging technique we developed. Since this system can be used to fabricate hydrogels containing enzymes only at the target sensors, glucose and H2O2 were separately monitored. The detection limit of glucose was less than 0.5 mM. In addition, the chitosan hydrogels were electrodeposited only in the target areas such that cells only adhering at unmodified areas, resulting in cell patterning. We show that the LSI device is useful for the fabrication of local hydrogels for several bioapplications such as biosensing and cell culturing.

End-to-End Autonomous Mobile Robot Navigation with Model-Based System Support

Autonomous mobile robot navigation in real unmodified outdoor areas frequented by people on their business, children playing, fast running bicycles, and even robots, remains a difficult challenge. For eleven years, the Tsukuba Challenge Real World Robot Challenge (RWRC) has brought together robots, researchers, companies, government, and ordinary citizens, under the same outdoor space to push forward the limits of autonomous mobile robots. For the Tsukuba Challenge 2017 participation, our team proposed to study the problem of sensors-to-actuators navigation (also called End-to-End), this is, having the robot to navigate towards the destination on a complex path, not only moving straight but also turning at intersections. End-to-End (E2E) navigation was implemented using a convolutional neural network (CNN): the robot learns how to go straight, turn left, and turn right, using camera images and trajectory data. E2E network training and evaluation was performed at Nagoya University, on similar outdoor conditions to that of Tsukuba Challenge 2017 (TC2017). Even thought E2E was trained on a different environment and conditions, the robot successfully followed the designated trajectory in the TC2017 course. Learning how to follow the road no matter the environment is of the key attributes of E2E based navigation. Our E2E does not perform obstacle avoidance and can be affected by illumination and seasonal changes. Therefore, to improve safety and add fault tolerance measures, we developed an E2E navigation approach with model-based system as backup. The model-based system is based on our open source autonomous vehicle software adapted to use on a mobile robot. In this work we describe our approach, implementation, experiences and main contributions.

Versatile Micropatterns of N-Heterocyclic Carbenes on Gold Surfaces: Increased Thermal and Pattern Stability with Enhanced Conductivity.

Patterned monolayers of N-heterocyclic carbenes (NHCs) on gold surfaces were obtained by microcontact printing of NHC-CO2 adducts and NHC(H)[HCO3 ] salts. The NHC-modified areas showed an increased conductivity compared to unmodified gold surface areas. Furthermore, the remaining surface areas could be modified with a second, azide-functionalized carbene, facilitating further applications and post-printing modifications. Thorough elucidation by a variety of analytical methods offers comprehensive evidence for the viability of the methodology reported here. The protocol enables facile access to versatile, microstructured NHC-modified gold surfaces with highly stable patterns, enhanced conductivity, and the option for further modification.

Morphological changes following vegetation removal and foredune re-profiling at Woonona Beach, New South Wales, Australia

Dunes are important for coastal protection, but their presence can sometimes be seen as conflicting with the recreational use of the coastline. In June 2014, in response to community concern, Wollongong City Council, a local government authority in southeast Australia, took the unconventional step of removing vegetation and re-profiling the foredune in a section of Woonona Beach to improve beach width and sightlines. A series of cross-sections in the re-profiled and adjacent unmodified areas have been surveyed monthly since July 2013, to help determine the impact of the intervention on beach and foredune topography. These show that immediately after re-profiling, considerable additional lower beach width was gained, and there was little accretion on the foredune that had been re-profiled. However, after 8 months, the importance of the re-profiling in maintaining lower beach width is less clear, and an incipient foredune is emerging at the new vegetation line, with about half the volume of sand removed during re-profiling re-deposited in this area. After 21 months, lower beach width gain from re-profiling had disappeared, and the volume of sand deposited on the new incipient foredune is more than the volume removed by the re-profiling. The results are discussed in terms of whether the short-term outcomes achieved by the re-profiling are being compromised, and what on-going management will be required to maintain these over the longer term. This study highlights the challenges facing coastal managers trying to balance conflicting community objectives at beaches backed by vegetated dunes.

Microbes in the Anthropocene: spillover of agriculturally selected bacteria and their impact on natural ecosystems.

Soil microbial communities are enormously diverse, with at least millions of species and trillions of genes unknown to science or poorly described. Soil microbial communities are key components of agriculture, for example, in provisioning nitrogen and protecting crops from pathogens, providing overall ecosystem services in excess of $1000bn per year. It is important to know how humans are affecting this hidden diversity. Much is known about the negative consequences of agricultural intensification on higher organisms, but almost nothing is known about how alterations to landscapes affect microbial diversity, distributions and processes. We review what is known about spatial flows of microbes and their response to land-use change, and outline nine hypotheses to advance research of microbiomes across landscapes. We hypothesize that intensified agriculture selects for certain taxa and genes, which then ‘spill over’ into adjacent unmodified areas and generate a halo of genetic differentiation around agricultural fields. Consequently, the spatial configuration and management intensity of different habitats combines with the dispersal ability of individual taxa to determine the extent of spillover, which can impact the functioning of adjacent unmodified habitats. When landscapes are heterogeneous and dispersal rates are high, this will select for large genomes that allow exploitation of multiple habitats, a process that may be accelerated through horizontal gene transfer. Continued expansion of agriculture will increase genotypic similarity, making microbial community functioning increasingly variable in human-dominated landscapes, potentially also impacting the consistent provisioning of ecosystem services. While the resulting economic costs have not been calculated, it is clear that dispersal dynamics of microbes should be taken into consideration to ensure that ecosystem functioning and services are maintained in agri-ecosystem mosaics.

Impacts of habitat change and protected areas on alpha and beta diversity of Mexican birds

AbstractAimsTo investigate how habitat change and different levels of protection interact to determine variation in the (alpha and beta) diversity of bird communities in three bioclimatic zones, considering the impacts of non‐native species, and the contribution of these effects to global (gamma) diversity.LocationSierra Gorda Biosphere Reserve, central Mexico.MethodsWe carried out bird surveys in a number of locations which varied according to their underlying vegetation type, their level of protection and the degree to which they had undergone modification by humans. We conducted a range of analyses to determine the impacts of protection and modification on the richness and mean global population trends of the species found in each location. We compared community composition to assess the homogenization effect of habitat modification.ResultsHuman‐modified environments in each of three bioclimatic zones held significantly greater numbers of species (alpha diversity) than unmodified habitats. Human‐mediated changes to local bird communities altered patterns of beta diversity in opposite directions; communities across bioclimatic zones were more similar to one another in modified areas than in unmodified areas but, on a local scale, modification of vegetation increased community dissimilarity. The changes are likely to contribute to a decline in global (gamma) diversity, given that globally vulnerable (declining) birds were mostly associated with unmodified, strictly protected areas.Main conclusionsWe highlight that assessment of human impacts and conservation need depends on the metric of biodiversity used and scale considered: small‐scale habitat change increased local and regional avian diversity but strictly protected areas are still required to protect globally vulnerable species.

Surface modification for patterned cell growth on substrates with pronounced topographies using sacrificial photoresist and parylene-C peel-off

A range of methods including soft lithography are available for patterning protein layers for cell adhesion on quasi-planar substrates. Suitably structured, these layers favor the geometrically constrained, controlled growth of cells and the development of cellular extensions on them. For this purpose, the ability to control the shape and dimension of cell-adhesive areas with high precision is crucial. For more advanced studies of cell interactions, the surface modification or functionalization of substrates with complex topographies is desirable. This paper describes a simple technique allowing to produce surface modification patterns using delicate molecules such as laminin on substrates exhibiting pronounced topographies with recessed and protruding microstructures. The technique is based on the combination of sacrificial photoresist structures with a connected parylene-C layer. This layer locally adheres to the substrate wherever the substrate needs to be protected against the surface modification. After surface modification, the parylene-C layer is peeled off. Patterns comprising arbitrary networks of modified and unmodified substrate areas can thus be realized. We demonstrate the technique with the guided growth of neuron-like PC12 cells on networks of laminin lines on substrates structured with micropillars and microwells.

The diet of Myotis lucifugus across Canada: assessing foraging quality and diet variability

Variation in prey resources influences the diet and behaviour of predators. When prey become limiting, predators may travel farther to find preferred food or adjust to existing local resources. When predators are habitat limited, local resource abundance impacts foraging success. We analysed the diet of Myotis lucifugus (little brown bats) from Nova Scotia (eastern Canada) to the Northwest Territories (north-western Canada). This distribution includes extremes of season length and temperature and encompasses colonies on rural monoculture farms, and in urban and unmodified areas. We recognized nearly 600 distinct species of prey, of which ≈30% could be identified using reference sequence libraries. We found a higher than expected use of lepidopterans, which comprised a range of dietary richness from ≈35% early in the summer to ≈55% by late summer. Diptera were the second largest prey group consumed, representing ≈45% of dietary diversity early in the summer. We observed extreme local dietary variability and variation among seasons and years. Based on the species of insects that were consumed, we observed that two locations support prey species with extremely low pollution and acidification tolerances, suggesting that these are areas without environmental contamination. We conclude that there is significant local population variability in little brown bat diet that is likely driven by seasonal and geographical changes in insect diversity, and that this prey may be a good indicator of environment quality.

A study of the galvanic replacement reaction at surfaces and the role of lateral charge propagation

The galvanic replacement of isolated nanostructures of copper and silver on conducting supports as well as continuous films of copper with gold is reported. The surface morphology was characterized by scanning electron microscopy and the replacement with gold was confirmed by EDX analysis. It was found that lateral charge propagation during the replacement reaction had a significant effect in all cases. For the isolated nanostructures the deposition of gold was observed not only at the sacrificial template but also at the surrounding unmodified areas of the conducting substrate. In the case of copper films the role of lateral charge propagation was also confirmed by connecting it to an ITO electrode through an external circuit upon which gold deposition was also observed to occur. Interestingly, by inhibiting the rate of charge propagation, through the introduction of a series resistor, the morphology of gold on the copper substrate could be changed from discrete surface decoration with cube like nanoparticles to a more porous rough surface.

Metapopulation structure and habitat quality in modelling dispersal in the butterflyIolana iolas

Quantifying dispersal is fundamental to understanding the effects of fragmentation on populations. Although it has been shown that patch and matrix quality can affect dispersal patterns, standard metapopulation models are usually based on the two basic variables, patch area and connectivity. In 2004 we studied migration patterns among 18 habitat patches in central Spain for the butterflyIolana iolas,using mark–release–recapture methods. We applied the virtual migration (VM) model and estimated the parameters of emigration, immigration and mortality separately for males and females. During parameter estimation and model simulations, we used original and modified patch areas accounting for habitat quality with three different indices. Two indices were based on adult and larval resources (flowers and fruits) and the other one on butterfly density. Based on unmodified areas, our results showed that both sexes were markedly different in their movements and mortality rates. Females emigrated more frequently from patches, but males that emigrated were estimated to move longer daily dispersal distances and suffer higher mortality than females during migration. Males were more likely to emigrate from small than from large patches, but patch area had no significant effect on female emigration. The effects of area on immigration rate and the within‐patch mortality were similar in both sexes. Based on modified areas, the estimated parameter values and the model simulation results were similar to those estimated using the unmodified patch areas. One possible reason for the failure to significantly improve the parameter estimates of the VM model is the fact that resource quantity and butterfly population sizes were strongly correlated with patch area. Our results suggest that the standard VM modelling approach, based on patch area and connectivity, can provide a realistic picture of the movement patterns ofI. iolas.

Rehabilitation of Rangelands in Paulshoek, Namaqualand: Understanding vegetation change using biophysical manipulations

In Namaqualand, heavy grazing of low-lying areas has resulted in the reduction of palatable perennial shrubs and the dominance of the unpalatable shrub, Galenia africana. This study investigates the process of rehabilitation and how it can be used to gain an understanding of the ecological factors that may be sustaining altered vegetation states. We intervened to change the biophysical environment through the construction of microcatchments and brushpacks to act as traps for water, seed and organic material combined with the introduction of seeds and seedlings were implemented. Two years after implementation brushpacked microhabitats improved natural recruitment of herbaceous species compared to bare areas at two out of three sites. Microhabitats did not influence natural recruitment of perennial seedlings. Emergence of palatable perennial seed was not influenced by microhabitat manipulation. Seedlings transplanted under adult G. africana shrubs showed higher survival rates at two out of three sites compared to seedlings in unmodified areas.