network coverage capacity
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Relay communication, in which the relay forwards the signal received by a source to a destination, has a massive consideration in research, due to its ability to expand the coverage, increase the capacity, and reduce the power consumption. In this paper, we proposed and investigated energy harvesting (EH) based two-way half-duplex (TWHD) relaying sensors network using selection combining (SC) over block Rayleigh fading channel. In this model, we proposed the direct link between two sources for improving the system performance. For the system performance analysis, we investigated and derived the closed-form of the exact and upper bound Ergodic capacity (EC) and the exact form of the symbol error ratio (SER). By using the Monte Carlo simulation, the correctness of the research results is verified in the influence of the main system parameters. From the discussions, we can see that the analytical and simulation agree well with each other.
- Klíčová slova
- SER, energy harvesting (EH), ergodic capacity (EC), sensors network, two-way,
- Publikační typ
- časopisecké články MeSH
Effective conservation of migratory species relies on habitat protection throughout their annual cycle. Although protected areas (PAs) play a central role in conservation, their effectiveness at conserving habitats across the annual cycle of migratory species has rarely been assessed. We developed seasonal ecological niche models for 418 migratory butterfly species across their global distribution to assess whether they were adequately represented in the PAs across their full annual cycle. PA coverage was inadequate in at least one season for 84% of migratory butterflies, adequate for only 17% of species in one season, and inadequate for 45% of species in all seasons. There was marked geographic variation in PA coverage: 77% of species met representation targets in Sri Lanka, for example, but only 32% met targets in Italy. Our results suggest that coordinated efforts across multiple countries will be needed to develop international networks of PAs that cover the full annual cycle of migratory insects and that conservation measures, in addition to the establishment and maintenance of PAs, are likely to be needed to effectively conserve these species.
Cobertura del área protegida del ciclo anual completo de las mariposas migratorias Resumen La conservación eficaz de las especies migratorias depende de la protección de los hábitats a lo largo de su ciclo anual. Aunque las áreas protegidas (AP) desempeñan un papel fundamental en la conservación, pocas veces se evalúa su eficacia para conservar los hábitats a lo largo del ciclo anual de las especies migratorias. Desarrollamos modelos de nicho ecológico estacional para 418 especies de mariposas migratorias a lo largo de su distribución global para evaluar si estaban adecuadamente representadas en las AP a lo largo de todo su ciclo anual. La cobertura de las áreas protegidas era inadecuada en al menos una estación para el 84% de las mariposas migratorias, adecuada para el 17% de las especies en una estación e inadecuada para el 45% de las especies en todas las estaciones. La cobertura de las zonas protegidas varía considerablemente según la zona geográfica: El 77% de las especies cumplieron los objetivos de representación en Sri Lanka, por ejemplo, pero sólo el 32% cumplieron los objetivos en Italia. Nuestros resultados sugieren que serán necesarios esfuerzos coordinados entre múltiples países para desarrollar redes internacionales de AP que cubran el ciclo anual completo de los insectos migratorios y que es probable que se necesiten medidas de conservación, además del establecimiento y mantenimiento de áreas protegidas, para la conservación eficaz de estas especies.
- Klíčová slova
- Kunming–Montreal Global Biodiversity Framework, Marco Mundial de Biodiversidad Kunming‐Montreal, conservación de insectos, conservation planning, insect conservation, mariposas migratorias, migratory butterflies, planeación de la conservación, protected area, área protegida,
- MeSH
- biologické modely MeSH
- ekosystém * MeSH
- migrace zvířat * MeSH
- motýli * fyziologie MeSH
- roční období MeSH
- zachování přírodních zdrojů * metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The amount of internet traffic generated during mass public events is significantly growing in a way that requires methods to increase the overall performance of the wireless network service. Recently, legacy methods in form of mobile cell sites, frequently called cells on wheels, were used. However, modern technologies are allowing the use of unmanned aerial vehicles (UAV) as a platform for network service extension instead of ground-based techniques. This results in the development of flying base stations (FBS) where the number of deployed FBSs depends on the demanded network capacity and specific user requirements. Large-scale events, such as outdoor music festivals or sporting competitions, requiring deployment of more than one FBS need a method to optimally distribute these aerial vehicles to achieve high capacity and minimize the cost. In this paper, we present a mathematical model for FBS deployment in large-scale scenarios. The model is based on a location set covering problem and the goal is to minimize the number of FBSs by finding their optimal locations. It is restricted by users' throughput requirements and FBSs' available throughput, also, all users that require connectivity must be served. Two meta-heuristic algorithms (cuckoo search and differential evolution) were implemented and verified on a real example of a music festival scenario. The results show that both algorithms are capable of finding a solution. The major difference is in the performance where differential evolution solves the problem six to eight times faster, thus it is more suitable for repetitive calculation. The obtained results can be used in commercial scenarios similar to the one used in this paper where providing sufficient connectivity is crucial for good user experience. The designed algorithms will serve for the network infrastructure design and for assessing the costs and feasibility of the use-case.
- Klíčová slova
- 5G, FBS, UAV base station, flying base station, location covering problem, location optimization, network coverage capacity, on-demand,
- MeSH
- algoritmy * MeSH
- teoretické modely * MeSH
- Publikační typ
- časopisecké články MeSH
The globalization in plant material trading has caused the emergence of invasive pests in many ecosystems, such as the alder pathogen Phytophthora ×alni in European riparian forests. Due to the ecological importance of alder to the functioning of rivers and the increasing incidence of P. ×alni-induced alder decline, effective and accessible decision tools are required to help managers and stakeholders control the disease. This study proposes a Bayesian belief network methodology to integrate diverse information on the factors affecting the survival and infection ability of P. ×alni in riparian habitats to help predict and manage disease incidence. The resulting Alder Decline Network (ADnet) management tool integrates information about alder decline from scientific literature, expert knowledge and empirical data. Expert knowledge was gathered through elicitation techniques that included 19 experts from 12 institutions and 8 countries. An original dataset was created covering 1189 European locations, from which P. ×alni occurrence was modeled based on bioclimatic variables. ADnet uncertainty was evaluated through its sensitivity to changes in states and three scenario analyses. The ADnet tool indicated that mild temperatures and high precipitation are key factors favoring pathogen survival. Flood timing, water velocity, and soil type have the strongest influence on disease incidence. ADnet can support ecosystem management decisions and knowledge transfer to address P. ×alni-induced alder decline at local or regional levels across Europe. Management actions such as avoiding the planting of potentially infected trees or removing man-made structures that increase the flooding period in disease-affected sites could decrease the incidence of alder disease in riparian forests and limit its spread. The coverage of the ADnet tool can be expanded by updating data on the pathogen's occurrence, particularly from its distributional limits. Research on the role of genetic variability in alder susceptibility and pathogen virulence may also help improve future ADnet versions.
- Klíčová slova
- Alnus, Decision support tool, Expert knowledge, Integrated pest management (IPM), Phytophthora ×alni, Riparian ecosystems,
- MeSH
- Bayesova věta * MeSH
- ekosystém MeSH
- lesy MeSH
- nemoci rostlin mikrobiologie statistika a číselné údaje MeSH
- olše * MeSH
- Phytophthora MeSH
- zachování přírodních zdrojů MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1-2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor β (TGFβ1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts.
- Klíčová slova
- Bilayer, Chitosan, Collagen, Oxidized cellulose, Polydopamine, Wound healing,
- MeSH
- myši MeSH
- nanovlákna * MeSH
- prasata MeSH
- sloučeniny osmia MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chloropentaammineosmium(III) chloride MeSH Prohlížeč
- polydopamine MeSH Prohlížeč
- sloučeniny osmia MeSH
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30]) as the proportion of landscape covered by N2000 sites increased. This positive relationship existed for 27 of the 104 butterfly species (estimates ranged from 0.382 [SD 0.163] to 4.28 [SD 0.768]), although most butterflies were generalists. For most species, when land-cover covariates were accounted for these positive relationships were not evident, meaning land cover may be a determinant of positive effects of the N2000 network. The increase in abundance as N2000 coverage increased correlated with the specialization index for birds, but not for butterflies. Although the N2000 network supports high abundance of a large spectrum of species, the low number of specialist butterflies with a positive association with the N2000 network shows the need to improve the habitat quality of N2000 sites that could harbor open-land butterfly specialists. For a better understanding of the processes involved, we advocate for standardized collection of data at N2000 sites.
Efectos de Natura 2000 sobre las Especies No Focales de Aves y Mariposas con Base en Datos de Ciencia Ciudadana Resumen La red Natura 2000 (N2000) de la Unión Europea está entre las redes internacionales más grandes de áreas protegidas. Uno de sus objetivos es asegurar el estado de un conjunto predeterminado de especies de aves y mariposas (focales). Sin embargo, las especies no focales también pueden beneficiarse con la N2000. Evaluamos cómo el componente terrestre de esta red afecta la abundancia de las especies de aves y mariposas no focales más comunes con base en los datos de programas de monitoreo voluntario a largo plazo en 9,602 sitios para aves y en 2,001 sitios para mariposas. En casi la mitad de las 155 especies de aves evaluadas, particularmente entre aquellas especies especialistas en zonas boscosas, la abundancia incrementó (los estimaciones de la pendiente variaron desde 0.101 [DS 0.042] hasta 3.51 [DS 1.30]) conforme incrementó la proporción del paisaje cubierto por sitios de la N2000. Esta relación positiva existió en 27 de las 104 especies de mariposas (con una variación de estimaciones desde 0.382 [DS 0.163] hasta 4.28 [DS 0.768]), aunque la mayoría de las especies de mariposas fueron generalistas. Cuando se consideraron las covarianzas de cobertura de suelo estas relaciones positivas no fueron evidentes para la mayoría de las especies, lo que significa que la cobertura de suelo puede ser una determinante de los efectos positivos de la red N2000. El incremento en la abundancia conforme aumentó la cobertura de la N2000 estuvo correlacionado con el índice de especialización de las aves, pero no el de las mariposas. Aunque la red N2000 sostiene la abundancia alta de un espectro amplio de especies, el bajo número de mariposas especialistas con una asociación positiva a la red N2000 demuestra la necesidad de mejorar la calidad del hábitat de los sitios N2000 que podrían albergar a mariposas especialistas de campo abierto. Para un mejor entendimiento de los procesos involucrados, promovemos una recolección estandarizada de datos en los sitios de la red N2000.
- Klíčová slova
- Directivas de Aves y Hábitats, European protection network, abundancia de especies, birds and habitats directives, breeding bird survey, butterfly monitoring schemes, censo de aves reproductoras, especialización de hábitat, esquemas de monitoreo de mariposas, habitat specialization, red europea de protección, species abundance, 欧洲保护网络, 物种丰度, 生境特化, 繁殖鸟种调查, 蝴蝶监测计划, 鸟类及生境指令,
- MeSH
- biodiverzita MeSH
- ekosystém MeSH
- motýli * MeSH
- občanská věda MeSH
- ptáci MeSH
- zachování přírodních zdrojů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In the present work, we use an exceptional database including 5,359 records of 101 species of Oman's terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman's 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).
- MeSH
- biodiverzita * MeSH
- ekosystém MeSH
- plazi klasifikace MeSH
- podnebí MeSH
- zachování přírodních zdrojů metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Omán MeSH
For the future of sixth-generation (6G) wireless communication, simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) technology is emerging as a promising solution to achieve lower power transmission and flawless coverage. To facilitate the performance analysis of RIS-assisted networks, the statistics of the sum of double random variables, i.e., the sum of the products of two random variables of the same distribution type, become vitally necessary. This paper applies the statistics of the sum of double random variables in the performance analysis of an integrated power beacon (PB) energy-harvesting (EH)-based NOMA-assisted STAR-RIS network to improve its outage probability (OP), ergodic rate, and average symbol error rate. Furthermore, the impact of imperfect successive interference cancellation (ipSIC) on system performance is also analyzed. The analysis provides the closed-form expressions of the OP and ergodic rate derived for both imperfect and perfect SIC (pSIC) cases. All analyses are supported by extensive simulation results, which help recommend optimized system parameters, including the time-switching factor, the number of reflecting elements, and the power allocation coefficients, to minimize the OP. Finally, the results demonstrate the superiority of the proposed framework compared to conventional NOMA and OMA systems.
The alarming decline of amphibians, sometimes marked by sudden extinctions, underlines the urgent need for increased conservation efforts. Conservationists recognize that more action, particularly the setting of national targets, is needed to ensure the future persistence and recovery of species and habitats. Protecting habitats that harbor evolutionarily diverse species preserves divergent genetic information within ecosystems. Türkiye holds 36 amphibian species at the intersection of two continents, creating three biodiversity hotspots and phylogenetic transitional areas. In this study, we aimed to determine the hotspot regions and to evaluate the effectiveness of the protected areas in Türkiye in preserving amphibian populations. First, we estimated four community indexes (species richness and three evolutionary distinctiveness measures) for amphibian communities in Türkiye divided into 371 grid cells with a ca 50 × 50 km size. Then, the spatial extent of protected areas is evaluated from two perspectives: current (has a protection status) and candidate protected areas (Key Biodiversity Areas, not protected) coverage in those grid cells. Finally, these two approaches' effectiveness in protecting areas was assessed by modeling four diversity metrics using GLS models. Current protected areas protect about 6% of the total amphibian distribution in Türkiye, while Key Biodiversity Areas would cover 30% if declared protected areas. We estimated that the coastal areas of Türkiye are identified as hotspots based on the four measured amphibian community indexes. Our study also highlights that Key Biodiversity Areas (KBAs) can contribute to conserving high levels of amphibian richness and evolutionary distinctiveness of species across Türkiye. However, existing protected areas (PAs) networks were insufficient to protect amphibians.
- Klíčová slova
- Amphibians, Community indexes, Ecological distinctiveness, Key biodiversity areas, Protected areas, Türkiye,
- MeSH
- biodiverzita * MeSH
- biologická evoluce MeSH
- ekosystém * MeSH
- fylogeneze MeSH
- obojživelníci * MeSH
- zachování přírodních zdrojů * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Rats (Rattus spp.) invaded most of the world as stowaways including some that carried the rat lungworm, Angiostrongylus cantonensis, the cause of eosinophilic meningoencephalitis in humans and other warm-blooded animals. A high genetic diversity of A. cantonensis based on short mitochondrial DNA regions is reported from Southeast Asia. However, the identity of invasive A. cantonensis is known for only a minority of countries. The affordability of next-generation sequencing for characterisation of A. cantonensis genomes should enable new insights into rat lung worm invasion and parasite identification in experimental studies. METHODS: Genomic DNA from morphologically verified A. cantonensis (two laboratory-maintained strains and two field isolates) was sequenced using low coverage whole genome sequencing. The complete mitochondrial genome was assembled and compared to published A. cantonensis and Angiostrongylus malaysiensis sequences. To determine if the commonly sequenced partial cox1 can unequivocally identify A. cantonensis genetic lineages, the diversity of cox1 was re-evaluated in the context of the publicly available cox1 sequences and the entire mitochondrial genomes. Published experimental studies available in Web of Science were systematically reviewed to reveal published identities of A. cantonensis used in experimental studies. RESULTS: New A. cantonensis mitochondrial genomes from Sydney (Australia), Hawaii (USA), Canary Islands (Spain) and Fatu Hiva (French Polynesia), were assembled from next-generation sequencing data. Comparison of A. cantonensis mitochondrial genomes from outside of Southeast Asia showed low genetic diversity (0.02-1.03%) within a single lineage of A. cantonensis. Both cox1 and cox2 were considered the preferred markers for A. cantonensis haplotype identification. Systematic review revealed that unequivocal A. cantonensis identification of strains used in experimental studies is hindered by absence of their genetic and geographical identity. CONCLUSIONS: Low coverage whole genome sequencing provides data enabling standardised identification of A. cantonensis laboratory strains and field isolates. The phenotype of invasive A. cantonensis, such as the capacity to establish in new territories, has a strong genetic component, as the A. cantonensis found outside of the original endemic area are genetically uniform. It is imperative that the genotype of A. cantonensis strains maintained in laboratories and used in experimental studies is unequivocally characterised.
- Klíčová slova
- Genetic diversity, Invasive species, Mitochondrial genome, Next-generation sequencing, Rat lungworm, Rattus, cox1,
- MeSH
- Angiostrongylus cantonensis genetika MeSH
- cyklooxygenasa 1 genetika MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- genom mitochondriální * MeSH
- genom u helmintů MeSH
- infekce hlísticemi řádu Strongylida parazitologie MeSH
- krysa rodu Rattus MeSH
- mitochondriální DNA * MeSH
- sekvenční analýza DNA MeSH
- sekvenování celého genomu MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Austrálie MeSH
- Havajské ostrovy MeSH
- Polynésie MeSH
- Španělsko MeSH
- Názvy látek
- cyklooxygenasa 1 MeSH
- mitochondriální DNA * MeSH