Target layer state estimation in multi-layer complex dynamical networks considering nonlinear node dynamics

In many engineering networks, only a part of target state variables are required to be estimated.On the other hand,multi-layer complex network exists widely in practical situations.In this paper, the state estimation of target state variables in multi-layer complex dynamical networks with nonlinear node dynamics is studied.A suitable functional state observer is constructed with the limited measurement.The parameters of the designed functional observer are obtained from the algebraic method and the stability of the functional observer is proven by the Lyapunov theorem.Some necessary conditions that need to be satisfied for the design of the functional state observer are obtained.Different from previous studies, in the multi-layer complex dynamical network with nonlinear node dynamics, the proposed method can estimate the state of target variables on some layers directly instead of estimating all the individual states.Thus, it can greatly reduce the placement of observers and computational cost.Numerical simulations with the three-layer complex dynamical network composed of three-dimensional nonlinear dynamical nodes are developed to verify the effectiveness of the method.

Response of Distribution Range Against Climate Change and Habitat Preference of Four National Protected Diploderma Species in Tibetan Plateau

Understanding the spatial distribution and habitat preference for rare and endangered species are essential for effective conservation practice.We examined the spatial distribution and habitat preference of four Diploderma species(Diploderma drukdaypo,D.laeviventre,D.batangense,and D.vela),which are endemic to the Qinghai-Tibet Plateau and are currently under state protection.We used the ensembles of small models(ESM)approach and predicted potential distribution ranges of the species in current and two future climate scenarios(SSP126 and SSP585).The degree of overlap between the predicted distribution ranges and existing natural reserves was further analyzed.Habitat preference was examined using a paired quadrat method.Our results predicted that D.drukdaypo has a current distribution range of 600 km^(2),which would decrease to 50 km^(2)and 55 km^(2)under the SSP126 and SSP585 respectively.For D.laeviventre,the current distribution range is 817 km^(2),with minimum changes in the two future climate scenarios(774 km^(2)and 902 km^(2)).For D.batangense,the current distribution range is 875 km^(2),which would expand to 1522 km^(2)and 3340 km^(2)in the two future climate scenarios.Similarly for D.vela,the current distribution range is 1369 km^(2),which would change to 1825 km^(2)and 2043 km^(2)respectively under the two future climate scenarios.The effect of protection of current nature reserves are likely low for those species;we found no overlap(D.drukdaypo,D.laeviventre)or little overlap(D.batangense 2.04%–3.56%,D.vela 15.52%–16.87%)between the currently designated protection area and distribution range under current and future climate scenarios.For habitat preference,stones appear to be the critical habitat element for those species although different species had different stone requirements.Taken together,we provided critical information on potential distribution ranges and habitat preference for four endangered Diploderma species,and confirmed the inadequacy of current nature reserves.The establishment of new or expansion of existing nature reserves is urgent for the conservation of those species.

Group Living on Trees Does Not Elevate Inbreeding Risk in Shedao Pit Vipers Gloydius shedaoensis

Group living has increasingly been emphasized due to its potential consequence on inbreeding, nevertheless, the relationship between group living and inbreeding risk is largely unknown. The endangered snake species, Shedao pit viper(Gloydius shedaoensis) inhabiting mostly on Shedao Island(meaning "snake island" in Chinese), provides an excellent model system for research on group living and inbreeding risk. Small island area, high population density and extreme seasonal foraging opportunity prompt many individuals to live on the same tree, which likely increase the potential mating among relatives. To confirm this probability, we used genotypes from 13 microsatellites DNA markers and examined the genetic relationships between pair of individuals lived on the same tree. The results showed that snakes on the same tree did not show closer relationships compared with individuals from different trees. The group constructions based on scenarios of parental-offspring, full-sibling, half-sibling as well as cousin were not consistent with tree-based group living. In addition, we did not find significant correlation between pair of individual genetic distance and geographic distance going beyond trees, suggesting group living on trees might not elevate inbreeding risk.

Climate change,thermal niches,extinction risk and maternal-effect rescue of toad-headed lizards,Phrynocephalus,in thermal extremes of the Arabian Peninsula to the Qinghai-Tibetan Plateau

Determining the susceptibility of species to changing thermal niches is a major goal for biologists.In this paper we develop an eco-physiological model of extinction risk under climate change premised on behavioral thermoregulation.Our method downscales operative environmental temperatures,which restrict hours of activity of lizards,hr,for present-day climate(1975)and future climate scenarios(2070).We apply our model using occurrence records of 20 Phrynocephalus lizards(or taxa in species complexes)drawn from literature and museum records.Our analysis is phylogenetically informed,because some clades may be more sensitive to rising temperatures.The limits for computed hr predict local extirpations among Phrynocephalus lizards at continental scales and delineate upper boundaries of thermal niches as defined by Extreme Value Distributions.Under the 8.5 Representative Concentration Pathway scenario,we predict extirpation of 64%of local populations by 2070 across 20 Phrynocephalus species,and 12 are at high risk of total extinction due to thermal limits being exceeded.In tandem with global strategies of lower CO_(2) emissions,we propose regional strategies for establishing new national parks to protect extinction-prone taxa by preserving high-elevation climate refugia within existing sites of species occurrence.We propose that evolved acclimatization–maternal plasticity–may ameliorate risk,but is poorly studied.Previous studies revealed that adaptive maternal plasticity by thermoregulating gravid females alter progeny thermal preferences by±1℃.We describe plasticity studies for extinction-prone species that could assess whether they might be buffered from climate warming–a self-rescue.We discuss an epigenetic framework for studying such maternal-effect evolution.

Low diversity,little genetic structure but no inbreeding in a high-density island endemic pit-viper Gloydius shedaoensis

Island species and their ecosystems play an important role in global biodiversity preservation,and many vulnerable island species are conservation priorities.Although insular habitat likely facilitates the species diversification process,it may also aggravate the fragility of these species with high risk of inbreeding.The Shedao pit-viper Gloydius shedaoensis is an island endemic species with an extremely high population density,which has been categorized as vulnerable in the IUCN(International Union for the Conservation of Nature and Natural Resources)Red List.We collected 13,148 SNP(Single Nucleotide Polymorphism)from across its genome and examined its genetic diversity and demographic history.The Shedao pit-viper has a low genetic diversity but shows no sign of inbreeding.Furthermore,population genetic structure analysis,including the neighbor-joining tree,principal coordinate analysis,clustering,and spatial autocorrelation,revealed a general lack of spatial structure.Only the isolation by distance residues suggested a weak patchiness.Overall,the population is nearly panmictic and gene flow is evenly distributed across the island.A large number of individuals,small size of the island,and the lack of population structure likely all contribute to the lack of inbreeding in this species.We also detected signs of male-biased dispersal,which likely is another inbreeding avoidance strategy.Historical demographic analysis suggested that the historical population size and distribution of the species are much larger than their current ones.The multiple transgressive–regressive events since the Late Pleistocene are likely the main cause of the population size changes.Taken together,our results provide a basic scientific foundation for the conservation of this interesting and important species.