Edge Of Patch Research Articles

Insect-friendly harvest in hay meadows – Uncut refuges are of vital importance for conservation management

With ongoing industrialisation of farming practise, the area of species-rich temperate grasslands has strongly declined. Today, the remnants of these grasslands often suffer from habitat degradation due to unsuitable management. Here, we investigated the effects of the complete harvest process over the course of two harvest periods (mid-June and mid-August) on Orthoptera (hereinafter referred to as ‘grasshoppers’) in species-rich lowland hay meadows in southwestern Bavaria (Germany). We set up a randomised split-plot design including mown meadows (tractor-operated rotary-disc vs. double-bladed bar mower) and uncut refuges within grassland patches. Our study revealed that mower types did not differ in their effects on grasshopper mortality and that direct mortality through cutting was very low. By contrast, after mowing, on average 85–91 % of the individuals or biomass was lost by the end of the harvest process. However, in uncut refuges, grasshopper densities and biomass increased on average by 234–328 %. From the first to the second harvest period, an alignment in grasshopper densities and biomass between meadows and uncut refuges occurred. We explain the lack of direct cutting effects by the tall and dense vegetation of the hay meadows and, hence, the location of the grasshoppers far above the sphere of the mowers. Moreover, we assume that in particular emigration from the short and homogeneous meadows to uncut refuges or patch edges but also increased vertebrate predation were responsible for the severe grasshopper losses. Moreover, we hypothesise that grasshopper recolonization from the refuges to the meadows strongly contributed to the alignment in grasshopper densities from mid-June to mid-August. Hence, to protect abundant grasshopper populations in meadows in the long run, uncut refuges are of prime importance. Firstly, such refuges guarantee a continuity in (i) food resources, (ii) a balanced microclimate and (iii) shelter against predators and extreme weather events for the resident individuals. Consequently, they are not affected by any of the harvest-related losses. Secondly, they serve as an important refuge for the emigrants from the mown parts of the meadow.

Decreased species richness along bare patch gradient in the degradation of Kobresia pasture on the Tibetan Plateau

The Kobresia pasture in the Tibetan Plateau, as the world's largest and most unique pastoral alpine ecosystem, is undergoing severe degradation, visible in the formation of bare patches. Characteristics of bare patches in Kobresia pastures are regarded as indicators of the fragmentation and degradation of the alpine landscapes. Here, we used unmanned aerial vehicles (UAV)-based low-elevation remote sensing to monitor 72 study sites in the eastern Tibetan Plateau for identifying the spatial patterns of bare patches of Kobresia pasture degradation on regional scale. We conducted field surveys of species composition, quantified fragmentation caused by bare patches using four landscape indices (patch area, total edge length, shape index and splitting index, representing the patch area, length of the edge, shape, and dispersion of the bare patches, respectively), then modeled the response of plant species richness and productivity at the scale of 50 × 50 m to the Kobresia pasture fragmentation process. Our results indicated that species richness and biomass production decreased significantly with each increasing bare patch index. The total edge length of bare patches increased the spatial turnover of plant species. Although bare patch area significantly decreased the species richness of plant communities, it led to a decrease in forb richness and an increase in grass richness along the degradation of Kobresia pastures.Bare patch areas, as the most easily accessible and highly accurate parameter by UAV-based low-elevation remote sensing, significantly related to the decrease in species richness and productivity, and mainly explained the changes in functional group composition. For assessing the ecological integrity of grassland functionality (plant species diversity and above-ground productivity), bare patch area can be used as an important indicator of Kobresia pasture degradation.

Patterns and drivers of early conifer regeneration following stand-replacing wildfire in Pacific Northwest (USA) temperate maritime forests

Tree regeneration is a critical mechanism of forest resilience to stand-replacing wildfire (i.e., where fire results in >90 % tree mortality), and post-fire regeneration is a concern worldwide as the climate becomes warmer. Although post-fire tree regeneration has been relatively well-studied in fire-prone forests across western North America, it is less understood in fire regimes characterized by large patches of stand-replacing fire at long intervals, such as the nominally infrequent, high-severity fire regimes of the western Cascades of Washington and northern Oregon, USA (northwestern Cascadia) where some of world’s highest-biomass forests reside. Recent wildfire activity (2015–2020) in northwestern Cascadia provides a unique opportunity to build understanding of the mechanisms underpinning forest resilience to fire, with implications for forest management and the myriad socio-ecological values associated with these landscapes. Here, we asked: how is post-fire conifer regeneration across northwestern Cascadia affected by pre-fire stand age, burn-patch size, and topo-climatic conditions? We established 39 1-ha long-term monitoring plots across four recent wildfires in northwestern Cascadia to measure post-fire conifer abundance and species composition. We used generalized linear models to test how rates of conifer regeneration (seedlings ha−1 yr−1 of all heights) and establishment (seedlings ha−1 yr−1 with heights >10 cm) respond to differences in pre-fire stand age/seral stage (young, mid-seral, late-seral), distance to the nearest live seed source, and post-fire topo-climate setting. In general, initial post-fire seedling densities suggest tree regeneration is abundant following stand-replacing fire in most areas across the region. For example, at 3–5 years post-fire, established seedlings were present in 100 % of plots, and regeneration and establishment levels exceeded state forest practices minimum density thresholds (470 seedlings ha−1) in 82.1 % and 64.1 % of plots, respectively. Post-fire conifer regeneration and tree species richness were greater when pre-fire stand age was older, and was more dominated by shade tolerant species than when pre-fire stand age was younger. Regeneration decreased with farther distances to the nearest live seed source, though seedlings were still moderately abundant at distances as far as 400 m from edges of high-severity patches. Conifer establishment was greater in areas characterized by cooler and wetter macrosite (e.g., greater post-fire precipitation) and microsite (e.g., greater bryophyte ground cover) conditions. By providing information on the drivers and conditions in which land managers can expect natural regeneration to occur or not, our findings are directly relevant to pre- and post-fire forest management objectives under future climate and increased fire activity in systems structured in part by infrequent and severe wildfires.

Design and analysis the performance of triangular patch antenna for THz applications

Modern technology advancement requires a more extensive data rate to convey information more rapidly than ever. Improved bandwidth can satisfy the need for high-speed transmission demand. In order to achieve significantly increased bandwidth for a high data rate communication, the antenna design at the THz band is essential. The microstrip patch antenna is one of the most prominent antennas for THz band applications such future 5G communication systems and advanced wireless communication system. This paper proposed a triangular patch antenna for THz applications where FR4 is used at the substrate as an insulator and Graphene at the patch as a conductor. Moreover, we improve the performance of the proposed antenna by modifying the shape of the patch and ground (GND) layer. We modify the patch shape by cutting the corner edge of the triangular patch. Moreover, the GND layer is modified with horizontally partial ground. The size of the proposed antenna is set to 160×120 µm2. We analyze the performance of the proposed antenna using CST simulation software. Based on the simulation results, the proposed antenna with a modified patch and GND shape shows wide bandwidth of 1.27 THz and minimal return loss of -33.22 dB at a resonant frequency of 2.28 THz. Additionally, the gain and efficiency of the suggested antenna show good improvement. Therefore, the proposed triangular patch antenna with a modified patch and GND shape is expected to be suitable for high-speed THz applications.

Investigations of Spatial and Temporal Land Use/Land Cover Changes in Trabzon Province (1990-2018) Using CORINE Maps and Landscape Metrics

In this study; it is aimed to analyze the temporal and spatial changes in land use/land cover of Trabzon province with the population increase in the 28-year period between 1990-2018 by analyzing it with CORINE maps and landscape metrics. Within the scope of the study, temporal variation analysis was carried out using CORINE maps of the years 1990, 2000, 2006, 2012 and 2018. In Trabzon, according to the CORINE classification system, a total of 4 main groups have been identified at the first level, and at the third level, 19 land use/land cover classes have been identified for 1990, 20 for 2000, 24 for 2006, and 26 for 2012 and 2018. It was observed that the most differentiation occurred in the agricultural areas class in the 28-year period. In addition, the metrics of class area (CA), number of patches (NumP), mean patch size (MPS), edge density (ED), total edge (TE) and mean shape index (MSI) were calculated through ARCGIS's Patch Analyst plugin in the study. The changes that have occurred have been examined. Accordingly, there has been a decrease in the size of forest and seminatural areas and agricultural areas with the increase in the size of the artificial surfaces due to the increase in human activities and population over the past 28 years. In addition, due to the continuous increase in the number of patches in the agricultural areas over time and the decrease in the average size of the patches, the fragmentation of the agricultural areas has been more common. The least change was in the water bodies. In line with the findings obtained, sustainable planning and land use suggestions for land use were presented.

Dune plants as a sink for beach litter: The species-specific role and edge effect on litter entrapment by plants

Anthropogenic litter accumulates along coasts worldwide. In addition to the flowing litter load, wind, sea currents, geomorphology and vegetation determine the distribution of litter trapped on the sandy coasts. Although some studies highlighted the role of dune plants in trapping marine litter, little is known about their efficiency as sinks and about the small-scale spatial distribution of litter across the dune area. Here, we explore these gaps by analysing six plant species widespread in Mediterranean coastal habitats, namely Echinophora spinosa, Limbarda crithmoides, Anthemis maritima, Pancratium maritimum, Thinopyrum junceum, and Salsola kali. The present study analyses for the first time the capture of litter by dune vegetation at a multi-species level, considering their morphological structure. Data on plastic accumulation on dune plants were compared with unvegetated control plots located at embryo-dune and foredune belts. We found that dunal plants mainly entrapped macrolitter (> 0.5 cm). Particularly, E. spinosa, L. crithmoides, A. maritima and P. maritimum mostly accumulated litter in the embryo dune while T. junceum and S. kali entrapped more in the foredune area. Moreover, beach litter was mainly blocked at the edge of the plant patches rather than in the core, highlighting the ‘Plant-edge litter effect’. As A. maritima and S. kali entrapped respectively more litter in embryo and foredune habitats, these species could be used to monitor and recollect litter. In this light, our findings provide further insight into the role of dune plants in the beach litter dynamics, suppling useful information for beach clean-up actions.

Epiphyte-host relationships of remnant and recombinant urban ecosystems in Hamilton, New Zealand: the importance of Dicksonia squarrosa (G.Forst.) Sw., whekī

ABSTRACT More than a thousand iNaturalist NZ observations were compiled and analysed to determine common vascular epiphyte-host relationships in Hamilton, North Island, New Zealand. Dicksonia squarrosa supported the most epiphytes, followed by Salix cinerea, Melicytus ramiflorus and Cyathea medullaris. Epiphytes displaying stronger host specificity, such as Tmesipteris elongata and Phlegmariurus varius, were often on D. squarrosa. In comparison, generalist epiphytes, including Pyrrosia eleagnifolia and Lecanopteris pustulata, were mainly on M. ramiflorus and S. cinerea. A detailed study of 60 D. squarrosa in a single gully investigated factors supporting the host quality of D. squarrosa. Dicksonia squarrosa diameter at breast height (DBH), height, caudex surface area, and distance to the stream and vegetation patch edge were measured. Dicksonia squarrosa that hosted epiphytes were significantly taller, further from the patch edge and had a larger surface area. Epiphyte species richness was higher on D. squarrosa further from the patch edge. The epiphyte communities examined are likely characteristic of highly modified urban ecosystems. Future research investigating the impact of host traits and microclimate on epiphyte-host networks is required to fully elucidate these relationships in urban environments.

Kinetics of Ganglioside-Rich Supported Lipid Bilayer Formation with Tracer Vesicle Fluorescence Imaging.

Gangliosides, forming a class of lipids complemented by sugar chains, influence the lateral distribution of membrane proteins or membrane-binding proteins, act as receptors for viruses and bacterial toxins, and mediate several types of cellular signaling. Gangliosides incorporated into supported lipid bilayers (SLBs) have been widely applied as a model system to examine these biological processes. In this work, we explored how ganglioside composition affects the kinetics of SLB formation using the vesicle rupturing method on a solid surface. We imaged the attachment of vesicles and the subsequent SLB formation using the time-lapse total internal reflection fluorescence microscopy technique. In the early phase, the ganglioside type and concentration influence the adsorption kinetics of vesicles and their residence/lifetime on the surface before rupturing. Our data confirm that a simultaneous rupturing of neighboring surface-adsorbed vesicles forms microscopic lipid patches on the surface and it is triggered by a critical coverage of the vesicles independent of their composition. In the SLB growth phase, lipid patches merge, forming a continuous SLB. The propagation of patch edges catalyzes the process and depends on the ganglioside type. Our pH-dependent experiments confirm that the polar/charged head groups of the gangliosides have a critical role in these steps and phases of SLB formation kinetics.

Cropland abandonment in a shrinking agricultural landscape: Patch-level measurement of different cropland fragmentation patterns in Central Iran

Cropland abandonment (CA) is a growing socio-economic and ecological concern worldwide. CA is formed as a gradual and spatiotemporally complex pattern of agricultural land change that affect accurate measurement of its magnitude and determinants. In this study, different spatial metrics including Attrition, Shrinkage, Fragmentation and Porosity are introduced and developed to better investigate CA in a highly water-deficient agricultural landscape (1964.5 km2) in Central Iran. Annual cropland layers were successfully produced from 1982 to 2022 using Landsat images and areas with more than 5 consecutive years of fallow in 10-year periods were classified as abandoned croplands. In each period, more than 20% of the relict agricultural land areas experienced CA. Moreover, CA represented a highly uneven spatio-temporal distribution. The majority of abandonment occurred on the periphery of active croplands either along the patch edge (Shrinkage) or deep penetration into crop patches (Fragmentation). The area of Porosity, measured as the abandonment holes inside active croplands, increased with increasing conversion of cropland to built-up areas. The complete abandonment of cropland patches (Attrition) was more dominant in resource deficit downstream parts, exhibiting the final stage of the transition from temporal to permanent CA. Results showed that the classification of CA by their spatial configuration shed light on the occurrence process of CA and its driving forces at different spatial and temporal scales.

Analysis of the Electrically Large Target in Isotropic Medium by the Physical Optics Method With Adaptive Mesh Technique

In this work, the physical optics (PO) method based on multilayered medium theory is used to analyze high-frequency scattering characteristics of plasma sheath covering an aircraft. The ray intersection method is taken for occlusion judgment, but some errors occur on the edge between illuminated and shadowed regions of a target. Therefore, the iterative edge patch segmentation based on adaptive mesh technique is proposed to reduce this error, which is significant to enhance computational accuracy of the PO method. Furthermore, to simplify the computational process and validate effectiveness of adaptive mesh technique, the plasma sheath covering a RAM-C II aircraft is modeled with a five-layered isotropic medium. Compared with uniform fine segmentation, the proposed adaptive mesh technique markedly reduces the computational cost by an order of magnitude while maintaining accuracy of the PO method. Moreover, high-frequency scattering characteristics of plasma sheath covering a RAM-C II aircraft under different flight conditions are presented via the bistatic radar cross section (RCS) with observable attenuation effects. Hence, the PO method for multilayered media combined with the proposed lit region judgment method is suitable to analyze scattering features of electrically large coated target.

DP14 Going against the grain: eosinophilic dermatosis presenting as erythema gyratum repens

Abstract Erythema gyratum repens (EGR) is a rare, paraneoplastic rash with a characteristic woodgrain appearance. It is heavily associated with malignancies, including lung, oesophageal and breast cancers. However, other conditions can mimic EGR, including leucocytoclastic vasculitis, immunobullous and papulosquamous conditions. We report an unusual presentation of eosinophilic dermatosis with an EGR-like pattern, not associated with malignancy. A 67-year-old woman presented with a 2-week history of a pruritic eruption on her legs. It initially started with three small circular erythematous macules on the right leg and one on the left leg. Over the course of a few days, the three macules evolved into large concentric annular patches simulating woodgrain, which raised the clinical suspicion of EGR. After a week, the patches began to blister with accentuation of some of the blisters on the edge of the annular patches. She denied any previous history of skin problems or changes in medication and was otherwise well with no systemic symptoms, including fever. In view of the almost 70% chance of an underlying malignancy, she was thoroughly investigated. Her full blood count, eosinophil count, liver function test, renal profile and serum C3 and C4 were normal. Skin basement membrane/desmosome antibodies and Borrelia burgdorferi IgG and IgM antibodies were also negative. Histology revealed prominent epidermal spongiosis with some corneal and intraepidermal vesicles that were cell-poor and contained only red blood cells. The underlying dermis showed prominent papillary dermal oedema with a brisk interstitial and superficial/deep perivascular mixed inflammatory infiltrate containing numerous eosinophils but no obvious flame figures. There was also eosinophil infiltration into the underlying subcutaneous fat. Direct immunofluorescence was negative. The histological pattern was that of an eosinophil-rich dermatitis with vesiculation; the history and morphology of the eruption were not compatible with bullous insect bites. An eosinophilic dermatosis such as eosinophilic cellulitis presenting with an EGR-like pattern was considered to be the most likely possibility for her presentation. Computed tomography of the neck, thorax, abdomen and pelvis, bidirectional endoscopy and mammography revealed no malignancies. She was treated with prednisolone 30 mg daily for 10 days with Elocon® ointment, and the eruption improved remarkably leaving postinflammatory colour changes that subsequently resolved. We would like to raise the awareness that an EGR-like pattern can be found in several other dermatoses, including eosinophilic dermatosis, and woodgrain pattern is not always equivalent to EGR or a high risk of associated malignancies (Table 1).Table 1Erythema gyratum repens-like dermatosesLeucocytoclastic vasculitisImmunobullousPapulosquamousBullous pemphigoidPsoriasisEpidermolysis bullosa acquisitaPityriasis rubra pilarisLinear IgA dermatoses

A simple equilibration procedure leading to polynomial-degree-robust a posteriori error estimators for the curl-curl problem

We introduce two a posteriori error estimators for Nédélec finite element discretizations of the curl-curl problem. These estimators pertain to a new Prager–Synge identity and an associated equilibration procedure. They are reliable and efficient, and the error estimates are polynomial-degree-robust. In addition, when the domain is convex, the reliability constants are fully computable. The proposed error estimators are also cheap and easy to implement, as they are computed by solving divergence-constrained minimization problems over edge patches. Numerical examples highlight our key findings, and show that both estimators are suited to drive adaptive refinement algorithms. Besides, these examples seem to indicate that guaranteed upper bounds can be achieved even in non-convex domains.

Turbulence Kinetic Energy and High-Order Moments of Velocity Fluctuations of Flows in the Presence of Submerged Vegetation in Pools

The flow in arid and semi-arid regions changes significantly during seasons, letting many vegetation patches develop in different parts of rivers. In the presence of aquatic plants in streams, different flow structures have resulted. When the water level increases in these rivers, the presence of vegetation patches influences the turbulent flow structures, which may considerably change the estimation of key hydraulic parameters. The results of earlier investigations indicated that a wide range of submerged and non-submerged vegetation influences the hydrodynamic features of flows in rivers and streams. In the present investigation, two pools with various slopes of entry and exit sections were used to conduct eight independent experiment runs. In addition, a vegetation patch over the entire pool section has been set up to investigate the effects of the vegetation patch on flow structures in pools. The effect of two slopes of 5 and 10 degrees for both entrance and exit of the pools on flow structure has been investigated. Considering two aspect ratios of 2.0 and 2.7, the distributions of flow velocity, Reynolds normal and shear stresses, turbulence intensities, turbulent kinetic energy (TKE), quadrant analysis, and spectral analysis have been studied at the trailing edge of the vegetation patch along an artificial pool. Results show that, for large entrance and exit slopes (10 degrees), the TKE distribution profiles have no specific form. However, the TKE values have a convex-shaped distribution pattern with the maximum TKE value near the bed when the slopes of the entrance and exit sections of the pool are small (5 degrees). Results showed that both ejections and sweeps govern the turbulence structures and coherent motions at the trailing edge of the vegetation patch along the pool. The geometry, entrance, and exit slopes of the pool have no effect on the validation of power spectral function compared to the presence of a vegetation patch in a flatbed.

Impact of urbanization on the spatial and temporal evolution of the water system pattern: A study of the Wuhan metropolitan area in China

With the rapid economic development and continuous urbanization, the status of river ecosystems is undergoing profound changes. Therefore, quantitative assessment of the impact of urbanization on the water system is highly desirable. Considering Wuhan metropolitan area as the study area, this study constructed an indicator system and used the entropy technique for order preference similarity to ideal solution (TOPSIS) method to quantify the urbanization level of each city. The urbanization process was divided into four periods based on the results of the urbanization level measurement. Then, the theory of landscape ecology was used to establish the evaluation index system of the water system pattern. Finally, the study used the grey relational analysis model to analyze the relationship between urbanization and evolution of water patterns under different periods. The results indicate that (1) from 2000 to 2019, the urbanization level of Wuhan metropolitan area exhibited an increasing trend, while the four indicators of the quantitative attribute and the two indicators of complexity showed a decline. (2) A negative correlation was observed between urbanization level and water system pattern indicators, with the correlation ranging from 0.55 to 0.62 (maximum value is 1). The urbanization process shows the most significant impact on the quantitative characteristics of water systems. (3) After classifying the urbanization stages, the correlation further increased between 0.55 and 0.95. (4) The four indicators of water patterns with the highest correlation with urbanization in the given periods are class area, area-weighted mean patch fractal dimension, edge density, and number of patches. Management can judge the corresponding human activities in relation to the current stage of the urbanization process and targeted protection of the water systems.

Recovery of upland acid grasslands after successful Pteridium aquilinum control: Long-term effectiveness of cutting, repeated herbicide treatment and bruising

There is a clear need for the development of management strategies to control dominant, perennial weeds and restore semi-natural communities and an important part of this is to know how long control treatments take to be effective and how long they last after treatments stop. Here, we report the results from a 17-year long experiment where we compared the effects of five control treatments on dense Pteridium aquilinum (L. Kuhn) relative to an untreated experimental-control in Derbyshire, UK. The experiment was run in two phases. In Phase 1 (2005–2012) we controlled the P. aquilinum by cutting and bruising, both twice and thrice annually, and a herbicide treatment (asulam in year 1, followed by annual spot-re-treatment of all emergent fronds). In Phase 2 (2012–2021) all treatments were stopped, and the vegetation was allowed to develop naturally. Between 2005 and 2021 we monitored P. aquilinum performance annually and full plant species composition at intervals. Here, we concentrate on analysing the Phase 2 data where we used regression approaches to model individual species responses through time and unconstrained ordination to compare treatment effects on the entire species composition over both Phases. Remote sensing was also used to assess edge invasion in 2018.At the end of Phase 1, a good reduction of P. aquilinum and restoration of acid-grassland was achieved for the asulam and cutting treatments, but not for bruising. In Phase 2, P. aquilinum increased through time in all treated plots but the asulam and cutting ones maintained a much lower P. aquilinum performance for nine years on all measures assessed. There was a reduction in species richness and richness fluctuations, especially in graminoid species. However, multivariate analysis showed that the asulam and cutting treatments were stationed some distance from the untreated and bruising treatments with no apparent sign of reversions suggesting an Alternative Stable State had been created, at least over this nine-year period. P. aquilinum reinvasion was mainly from plot edges.The use of repeated P. aquilinum control treatments, either through an initial asulam spray with annual follow-up spot-spraying or cutting twice or thrice annually for eight years gave good P. aquilinum control and helped restore an acid-grassland community. Edge reinvasion was detected, and it is recommended that either whole-patch control be implemented or treatments should be continued around patch edges.

Investigation of air breakdown and plasma evolution on microstrip antenna surface using the particle-in-cell method

This paper investigates the breakdown of two microstrip antennas through experiments and particle-in-cell simulations. The breakdown thresholds of a microstrip dipole antenna and a double-layer patch microstrip antenna are investigated experimentally and found to be 15.6 and 30.8 kW, respectively. Ablation is observed on the surface of the antennas, indicating that the local electric field is particularly intense. To further understand the breakdown process, the particle-in-cell and Monte Carlo collision methods are combined to investigate the inception and development of partial discharge on the surface of the antennas. Under the criterion of continuous electron density growth, the breakdown thresholds of the dipole and double-layer patch antennas are estimated to be 19.4 and 52.9 kW in our simulations. The simulation results are in reasonable agreement with the experimental measurements. In the microstrip dipole antenna, the plasma evolution of the partial discharge is initiated near the tip, while the electric field close to the tip is distorted and a positive streamer directed toward the tip is observed. In the double-layer patch microstrip antenna, a more uniform discharge is observed at the edge of the circular patch in the simulations.

Highly selective multiple-notched UWB-MIMO antenna with low correlation using an innovative parasitic decoupling structure

In ultra-wideband (UWB) communications, highly selective notch bands are required to avoid interference with other licensed bands. This study presents a highly selective triple-notch UWB-MIMO antenna, which consists of a four-radiating patch antenna and an isolator. The single-element antenna consists of a radiating patch, substrate, ground plane, electromagnetic bandgap (EBG) structures, and split ring resonators (SRR). To achieve the designated UWB bandwidth, the lower edges of the antenna patch are cut by a quarter-circle radius. The three sharp notches are achieved by utilizing four EBGs and two SRRs at the back of the antenna. The notch bandwidth can also be controlled by changing the parameters such as the width and length of the EBG structure and SRR. The single antenna is then translated into 4-port MIMO systems. The high correlation between elements is reduced by inserting a unique parasitic decoupling structure. The decoupling structure is designed in a way that reduces the mutual coupling in all passbands. The proposed antenna offers a (|S11| < –10 dB) of 3.1 – 11.8 GHz impedance bandwidth. The proposed MIMO antenna having an overall size of 54 × 54 × 1.52 mm3 is fabricated to verify the simulation results. The MIMO antenna shows exceptional diversity properties, including better isolation between unit elements of MIMO antenna (>20 dB), a diversity gain (DG) very close to 10 dB (>9.99 dB), an envelope correlation coefficient which is less than 0.001, and suitable mean effective gain is also in the defined range. The suggested parasitic element UWB – MIMO antenna thus supports its suitability for use in UWB communication networks.

Alhamd treatment of vitiligo, a study of needling+ excimer laser @308nm

Introduction: Vitiligo is a chronic autoimmune disorder where pigment producing cells in skin called melanocytes are attacked and destroyed causing milky white patches in skin. Our study to treat vitiligo is a combination of EXCIMER LASER @308nm,1,2,3 + NEEDLING.4 This study is based on a theme that the melanocytes in the normal skin around the vitiligo patch can be pushed into the Vitiligo patch and subsequent EXCIMER induced melanogenesis treats vitiligo.5 Methods: We use a 30G, 4mm stem needle. Push it through the normal skin into the vitiligo patch at the level of the D-E junction parallel to the skin. This needle push called NEEDLING drags epidermal cells including melanocytes as micro inoculation to produce multiple small populations of melanocytes in the vitiligo area,6 which is then exposed to EXCIMER to cause melanogenesis and hence repigmentation of the area.3,5,7 Multiple needle pushes are made through normal skin around the vitiligo patch, into the vitiligo patch. These needle pushes are done 1cm apart. All patients are having needling once weekly and EXCIMER 2-3 times per week.4,6 A study of this combination was done over 50 patients, in both sexes in different age groups from October 2021 to September 2022 and follow up still continued. A comparison was also done with EXCIMER alone (without needling) in some of these patients at some patches.8 Inclusion and exclusion criteria, a result criteria and a study Performa with follow-up details was set. Photos of all the patients were taken before treatment and then every 3 weeks. Results: Our combination treatment has proved very effective for vitiligo as compared to EXCIMER alone. Most patients had fast repigmentation. The best results are on the face and trunk4,6 with more then 90% repigmentation in all age groups. Repigmentation is good but slow towards peripheral parts.9,10 Repigmentation was specially noticed to start from the edge of the vitiligo patch (where needling is done) as tiny black dots and further needling through these dots gradually repigmented the central areas.4 (Figure 2, 3, 4, 6). Repigmentaion is also good over areas with grey hair with this technique as needling uses melanocytes of the skin surrounding the vitiligo patch rather than the follicular cells. This further strengthened the idea of needling as a useful combination with EXCIMER.

Objective detection of shear distortion of low-light-level image intensifier based on global scanning and image patch edge feature analysis

Objective detection of shear distortion of low-light-level image intensifier based on global scanning and image patch edge feature analysis

Quantitative Landscape Analysis Using Earth-Observation Data: An Example from Chania, Crete, Greece

Pursuing sustainability in a challenging world and under the influence of numerous natural and anthropogenic drivers of change presents one of the major global concerns. The transition towards a more sustainable development requires a harmonious balance between human well-being and environmental management. The concept of landscape is at the core of such a process. Hence, evaluating the different aspects of the landscape and their components is crucial for policy making, planning and management. In fact, landscape quality assessment has become a special focus of interest, especially with the directives of the European Landscape Convention. This research work aims to analyze the rural landscape of the Chania prefecture, West Crete, Greece, taking into account its multifold dimensions. The analysis was carried out using a series of quantitative spatial indicators. Consecutively, structural (mean patch area, contagion index, edge density and percentage of landscape occupied by a class of the highest share), ecological (density of ecological barriers, Modified Shannon diversity index), visual (share of positive land-cover forms, share of negative land-cover forms, form and color disharmony index, shape disharmony index) and cultural indices (historical monuments index) were estimated and analyzed in a GIS environment. The overall methodology incorporated different land-use/land-cover data (multitemporal Corine data and land use derived from the classification of Earth-observation (EO) data). The historical and current analysis of the landscape within Chania revealed quite high structural and visual values. The ecological dimension is rather stable, with a potential decrease by the year 2045. Additionally, the structural dimension seemed to be sensitive to the spatial resolution of the data source. The spatial extent, at which the landscape is evaluated, seemed to impact the landscape’s ecological, visual and cultural values.