Construction of a refined population analysis unit based on urban forms and population aggregation patterns

The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from urban forms,and cannot be used to consider the characteristics of population distributions and flow changes.In this study,we proposed a method for constructing a fine population analysis zone(FPAZ)based on the population aggregation pattern and urban form elements.First,considering the spatial structure of a city and the fine-grained demands of population analysis,the basic analysis unit was divided according to the functional heterogeneity of the population activity region at the micro-scale by combining urban form elements.Next,a population aggregation preference model was established by considering the spatial distribution characteristics of the local aggregation of the urban population flow and long-term stability characteristics depending on the dynamic changes in entrances and exits.Finally,we divided the FPAZ combined with the microstructural elements.Experimental results showed that compared with other types of PAUs,the FPAZ was more consistent with the urban morphology and was an appropriate and general spatial unit for expressing the accurate characteristics of population distributions and changes at the micro-scale.

Genetic diversity and population structure analysis of 161 broccoli cultivars based on SNP markers

To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on single nucleotide polymorphism(SNP)markers.Ten pairs of primers with good polymorphism and high resolution were screened from 315 pairs of SNP primers by 3 broccoli accessions(inbred lines)with different phenotypes and maturity.The 10 pairs of SNP primers were selected,producing 78 alleles.The diversity analysis indicated that the polymorphism information content(PIC)of SNP primer ranged from 0.64 to 0.90.The observed number of alleles(Na)was 2.00,the effective number of alleles(Ne)was 1.11–2.00,the Nei’s gene diversity(H)was 0.10–0.50,and Shannon information index(I)was 0.20–0.70 using PopGene32 software.The clustering results showed that the 161 broccoli cultivars could be divided into 4 major subgroups(A,B,C and D),foreign cultivars were all assigned to subgroup A,and domestic cultivars were assigned to 3 subgroups of B,C,and D.This study indicated that some domestic cultivars and foreign cultivars were similar in genetic background,but most domestic cultivars were still different from the Japanese cultivars.When K=2,the population structure result presented that 161 broccoli cultivars could be divided into 1 simple group(2 groups)and 1 mixed group.When Q≥0.6,143(88.82%)broccoli cultivars belonged to the simple groups.In simple groups 68(42.24%)broccoli cultivars of group 1 were derived from Japan,the United States,Switzerland,the Netherlands,China-Taiwan,and China-Mainland;75(46.58%)broccoli cultivars belonged to group 2;when Q<0.6,18(11.18%)broccoli cultivars belonged to the mixed groups.This study is helpful to understand the diversity and resolution of broccoli cultivars from worldwide,which is beneficial to plant breeding and materials innovation.And meanwhile,this result is also used for construction of broccoli fingerprint serving for cultivar identification.

Can we reestablish a self-sustaining population?A case study on reintroduced Crested Ibis with population viability analysis

Background:One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability.The wild population of the Crested Ibis(Nipponia nippon)has recovered to approximately 4400,and several reintroduction programs have been carried out in China,Japan and Korea.Population viability analysis on this endangered species has been limited to the wild population,showing that the long-term population growth is restricted by the carrying capacity and inbreeding.However,gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery.Methods:The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan,China from 2007 to 2018.An individual-based VORTEX model(Version 10.3.5.0)was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency,mortality and sex ratio.Results:The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years.The popula-tion size was estimated to be 367,and the population genetic diversity was estimated to be 0.97.Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio.The carrying capacity is the main factor accounting for the population size and genetic diversity,while the sex ratio is the primary factor responsible for the population growth trend.Conclusions:A viable population of the Crested Ibis can be established according to population viability analysis.Based on our results,conservation management should prioritize a balanced sex ratio,high-quality habitat and low mortality.

Fluorometric Discrimination Technique of Phytoplankton Population Based on Wavelet Analysis

The discrete excitation-emission-matrix fluorescence spectra (EEMS) at 12 excitation wavelengths (400, 430, 450, 460, 470, 490, 500, 510, 525, 550, 570, and 590 nm) and emission wavelengths ranging from 600-750 nm were determined for 43 phytoplankton species. A two-rank fluorescence spectra database was established by wavelet analysis and a fluorometric discrimination technique for determining phytoplankton population was developed. For laboratory simulatively mixed samples, the samples mixed from 43 algal species (the algae of one division accounted for 25%, 50%, 75%, 85%, and 100% of the gross biomass, respectively), the average discrimination rates at the level of division were 65.0%, 87.5%, 98.6%, 99.0%, and 99.1%, with average relative contents of 18.9%, 44.5%, 68.9%, 73.4%, and 82.9%, respectively; the samples mixed from 32 red tide algal species (the dominant species accounted for 60%, 70%, 80%, 90%, and 100% of the gross biomass, respectively), the average correct discrimination rates of the dominant species at the level of genus were 63.3%, 74.2%, 78.8%, 83.4%, and 79.4%, respectively. For the 81 laboratory mixed samples with the dominant species accounting for 75% of the gross biomass (chlorophyll), the discrimination rates of the dominant species were 95.1% and 72.8% at the level of division and genus, respectively. For the 12 samples collected from the mesocosm experiment in Maidao Bay of Qingdao in August 2007, the dominant species of the 11 samples were recognized at the division level and the dominant species of four of the five samples in which the dominant species accounted for more than 80% of the gross biomass were discriminated at the genus level; for the 12 samples obtained from Jiaozhou Bay in August 2007, the dominant species of all the 12 samples were recognized at the division level. The technique can be directly applied to fluorescence spectrophotometers and to the developing of an in situ algae fluorescence auto-analyzer for phytoplankton population.

Analysis of Migrant Population's Social Integration in Hangzhou

Since China began implementing reform and opening-up policies, along with a fast development of the national economy and great changes of social life, an increasing number of peasan＇s have kept flowing into cities and economically more developed regions. Aspiring to improve their life and yearning for a better urban life, they defy the restraint of the household registry system and, in the process of moving from one place to another, ignore economic and psychological costs. As early as in year 2000 China＇s migrant population reached 140 million, more than 10% of the total population. Since 2000 the migrant poptilation in Zhejiang Province, east China, has kept growing by 20% annually, the second fastest in the country for seven consecutive years.

A Multi-strategy Improved Snake Optimizer Assisted with Population Crowding Analysis for Engineering Design Problems

Snake Optimizer(SO)is a novel Meta-heuristic Algorithm(MA)inspired by the mating behaviour of snakes,which has achieved success in global numerical optimization problems and practical engineering applications.However,it also has certain drawbacks for the exploration stage and the egg hatch process,resulting in slow convergence speed and inferior solution quality.To address the above issues,a novel multi-strategy improved SO(MISO)with the assistance of population crowding analysis is proposed in this article.In the algorithm,a novel multi-strategy operator is designed for the exploration stage,which not only focuses on using the information of better performing individuals to improve the quality of solution,but also focuses on maintaining population diversity.To boost the efficiency of the egg hatch process,the multi-strategy egg hatch process is proposed to regenerate individuals according to the results of the population crowding analysis.In addition,a local search method is employed to further enhance the convergence speed and the local search capability.MISO is first compared with three sets of algorithms in the CEC2020 benchmark functions,including SO with its two recently discussed variants,ten advanced MAs,and six powerful CEC competition algorithms.The performance of MISO is then verified on five practical engineering design problems.The experimental results show that MISO provides a promising performance for the above optimization cases in terms of convergence speed and solution quality.

Integrated Analysis of the Trees and Associated UnderCanopy Species in a Subalpine Forest of Western Himalaya,Uttarakhand, India

Subalpine forests are known as outstanding habitats due to co-existence of both temperate and alpine vegetation and are classic example of ecotonal zones. Limited but diverse physiognomy of trees inhabiting in subalpine forest results in variability within under-canopy habitat conditions. Studies were undertaken to assess population status, habitat preference and interferences to the trees and associated under-canopy herbs in a subalpine forest of western Himalaya. A total of lo woody and 23 under-canopy herbs were recorded in the selected subalpine forest area. At each stand, the number of tree species and under-canopy herbs ranged from 2 to 4 and 8 to lo respectively. Abies spectabilis, Acer caesium, Quercus floribunda, Q. semecarpifolia and Rhododendron arboreum were key tree species in this area. The density of main woody species was 280 to 119o individuals ha-1 at different stands. Herbaceous plants with rosette and clump growth habits were observed to have higher values for total basal cover and importance value index. Presence of some under- canopy herbs like; Dactylorhiza hatagirea, Malaxis muscifera, Picrorhiza kurrooa, Polygonatum cirrhifolium habitats also and Skimmia laureola showed that they are in the habitat specific specific. However, the presence of Frageria nubicola and Viola sp. was common in the selected stands. Felling of trees for timber, construction of temporary huts, fuel wood and lopping for fodder were main interferences for trees. On the other hand, trampling driven damage due to grazing, habitats degradation and overexploitation were observed key threats for under-canopy herbs. Integrated analysis including population studies, habitats preference and interferences to the trees and under-canopy herbs in this sensitive and important ecosystem will be useful for determining the conservation plans and ecosystem management.

A first-principle calculation of structural,mechanical and electronic properties of titanium borides

The first-principle calculations are performed to investigate the structural,mechanical and electronic properties of titanium borides （Ti2B,TiB and TiB2）.Those calculated lattice parameters are in good agreement with the experimental data and previous theoretical values.All these borides are found to be mechanically stable at ambient pressure.Compared with parent metal Ti （120 GPa）,the larger bulk modulus of these borides increase successively with the increase of the boron content in three borides,which may be due to direction bonding introduced by the boron atoms in the lattice and the strong covalent Ti-B bonds.Additionally,TiB can be regarded as a candidate of incompressible and hard material besides TiB2.Furthermore,the elastic anisotropy and Debye temperatures are also discussed by investigating the elastic constants and moduli.Electronic density of states and atomic Mulliken charges analysis show that chemical bonding in these titanium borides is a complex mixture of covalent,ionic,and metallic characters.

Structural, Electronic Properties and Chemical Bonding of Borate Li4CaB2O6 under High Pressure： an Ab Initio Investigation

We calculate structural, electronic properties and chemical bonding of borate Li4CaB2O6 under high pressure by means of the local density-functional pseudopotential approach. The equilibrium lattice constants, density of states, Mulliken population, bond lengths, bond angles as well as the pressure dependence of the band gap are presented. Analysis of the simulated high pressure band structure suggests that borate Li4CaB2O6 can be used as the semi-conductor optical material. Based on the Mulliken population analysis, it is found that the electron transfer of the Li atom is very different from that of other atoms in the studied range of high pressures. The charge populations of the Li atom decrease with the pressure up to 60 GPa, then increase with the pressure.

Research on Variable Selection of Protein in Soy Lysine Spectroscopy Based on Latent Projective Graph

[Objectives] This study was conducted to solve the problems of complex near-infrared spectrum information of soybean lysine, serious collinearity and insufficient predictive ability of full-spectrum modeling. [Methods] A new variable selection method, i.e., variable combination model population analysis method, was used to select characteristic wavelengths of soybean lysine near infrared spectra. The binary matrix sampling strategy and exponential decay function were used at first to delete the variables providing no information and select the near-infrared characteristic wavelengths of soybean lysine, which were then combined the partial least square method to establish a prediction model. Compared with other variable selection methods, the Monte Carlo variable combination model population analysis method selected the least wavelength points and the model had the strongest predictive ability. The variable combination model population analysis method adopting the binary matrix sampling strategy made up for the shortcomings of the single Monte Carlo sampling method. [Results] The experimental results showed that the Monte Carlo variable combination model population analysis algorithm could better select the characteristic wavelengths of soybean lysine NIR spectra and improve the reliability of the prediction model. However, in general, the accuracy of the lysine prediction model is not satisfactory, and it needs to be further reconstructed and optimized in future research work. The reason might be that the determination accuracy of the chemical value of lysine content was insufficient, or it might be caused by the poor absorption of the hydrogen-containing group of lysine in the near-infrared spectrum region and the poor correlation with proteins. [Conclusions] This study provides a reference for soybean high-lysine breeding.

Population viability analysis of small population:a case study for Asian elephant in China

Small populations are at risk of extinction from deterministic and stochastic factors.Less than 250 Asian elephants(Elephas maximus)remain in China,and are distributed in a few isolated areas;yet,population viability analyses of this endangered population have not been conducted.Here,the current genetic status of the Pu’Er-Mengyang Asian elephant populations in China was analyzed,and the risk of extinction was predicted over the next 500 years.Factors affecting the viability of this population were determined through simulations.The genetic diversity of the population was very low(mean allele number:3.1;expected heterozygosity:0.463),even though a recent population bottleneck was not detected.The effective population size was approximately 24.1 adult elephants.Enough adult breeding individuals exist to maintain population viability.VORTEX simulation model showed that this population would not go extinct in the next 500 years.However,illegal poaching and harvesting could negatively affect population size.A sensitivity analysis showed that the mean stochastic growth rate of the study population is sensitive to sex ratio,number of breeding females,mortality of females of different age classes,carrying capacity,and lethal equivalents.Based on our results,we suggest that action should be taken to alleviate inbreeding and any further loss of genetic diversity,by connecting fragmented elephant habitat or by translocating individual elephants.In addition,human–elephant conflict should be mitigated using various modern approaches,including crop guarding techniques,and by encouraging farmers to switch to crops and income sources not vulnerable to elephant raids.

Genetic Analysis of 15 STR Loci in Chinese Han Population from West China

Allele frequencies for 15 short tandem repeat （STR） loci （D8S1179, D21S11, D7S820, CSFIPO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA） were obtained from 7,636 unrelated individuals of Chinese Han population living in Qinghai and Chongqing, China. Totally 206 alleles were observed, with the corresponding allele frequencies ranging from 0.0001-0.4982. Chi-square test showed that all of the STR loci agreed with the Hardy-Weinberg equilibrium. We also compared our data with previously published population data of other ethnics or areas. The results are valuable for human identification and paternity testing in Chinese Han population.

Population viability analysis: using a modeling tool to assess the viability of tapir populations in fragmented landscapes

A population viability analysis(PVA)was conducted of the lowland tapir populations in the Atlantic Forest of the Pontal do Paranapanema region,Brazil,including Morro do Diabo State Park(MDSP)and surrounding forest fragments.Results from the model projected that the population of 126 tapirs in MDSP is likely to per-sist over the next 100 years;however,200 tapirs would be required to maintain a viable population.Sensitiv-ity analysis showed that sub-adult mortality and adult mortality have the strongest influence on the dynamics of lowland tapir populations.High road-kill has a major impact on the MDSP tapir population and can lead to population extinction.Metapopulation modeling showed that dispersal of tapirs from MDSP to the surrounding fragments can be detrimental to the overall metapopulation,as fragments act as sinks.Nevertheless,the model showed that under certain conditions the maintenance of the metapopulation dynamics might be determinant for the persistence of tapirs in the region,particularly in the smaller fragments.The establishment of corridors con-necting MDSP to the forest fragments models resulted in an increase in the stochastic growth rate,making ta-pirs more resilient to threats and catastrophes,but only if rates of mortality were not increased when using cor-ridors.The PVA showed that the conservation of tapirs in the Pontal region depends on:the effective protection of MDSP;maintenance and,whenever possible,enhancement of the functional connectivity of the landscape,reducing mortality during dispersal and threats in the unprotected forest fragments;and neutralization of all threats affecting tapirs in the smaller forest fragments.

COVARIANCE STRUCTURAL ANALYSIS WITH POLYTOMOUS VARIABLES IN SEVERAL POPULATIONS

In this paper, covariance structures with polytomous variables in several populations are analyzed. A computationally efficient multistage procedure is proposed to estimate the thresholds and the covariance structure parameters.Statistical properties of the estimators are derived, and a computer program is implemented to obtain the solution. An artificial example is presented to illustrate the method.

Addressing the impact of canine distemper spreading on an isolated tiger population in northeast Asia

The continuation of the isolated Amur tiger(Panthera tigris altaica)population living along the China-Russia border is facing serious challenges due to factors such as its small size(including 38 individuals)and canine distemper virus(CDV).We use a population viability analysis metamodel,which consists of a traditional individual-based demographic model linked to an epidemiological model,to assess options for controlling the impact of negative factors through domestic dog management in protected areas,increasing connectivity to the neighboring large population(including more than 400 individuals),and habitat expansion.Without intervention,under inbreeding depression of 3.14,6.29,and 12.26 lethal equivalents,our metamodel predicted the extinction within 100 years is 64.4%,90.6%,and 99.8%,respectively.In addition,the simulation results showed that dog management or habitat expansion independently will not ensure tiger population viability for the next 100 years,and connectivity to the neighboring population would only keep the population size from rapidly declining.However,when the above three conservation scenarios are combined,even at the highest level of 12.26 lethal equivalents inbreeding depression,population size will not decline and the probability of extinction will be<5.8%.Our findings highlight that protecting the Amur tiger necessitates a multifaceted synergistic effort.Our key management recommendations for this population underline the importance of reducing CDV threats and expanding tiger occupancy to its former range in China,but re-establishing habitat connectivity to the neighboring population is an important long-term objective.

A Proportion Analysis of City/Town Population in China's Fourth Census in 1990

On the basis of the analysis of the standards for the city/town populationstatistics in the past censuses,the author makes a proportional analysis of the city/townpopulation according to the data obtained from the fourth census,and points out the dis-crepancies in the standard for the the city/town population statistics used in the fourthcensus and proposes ways for their correction.

Could wastewater analysis be a useful tool for China?——A review

Analysing wastewater samples is an innovative approach that overcomes many limitations of traditional surveys to identify and measure a range of chemicals that were consumed by or exposed to people living in a sewer catchment area. First conceptualised in 2001, much progress has been made to make wastewater analysis（WWA） a reliable and robust tool for measuring chemical consumption and/or exposure. At the moment, the most popular application of WWA, sometimes referred as sewage epidemiology, is to monitor the consumption of illicit drugs in communities around the globe, including China. The approach has been largely adopted by law enforcement agencies as a device to monitor the temporal and geographical patterns of drug consumption. In the future, the methodology can be extended to other chemicals including biomarkers of population health（e.g. environmental or oxidative stress biomarkers, lifestyle indicators or medications that are taken by different demographic groups） and pollutants that people are exposed to（e.g. polycyclic aromatic hydrocarbons,perfluorinated chemicals, and toxic pesticides）. The extension of WWA to a huge range of chemicals may give rise to a field called sewage chemical-information mining（SCIM） with unexplored potentials. China has many densely populated cities with thousands of sewage treatment plants which are favourable for applying WWA/SCIM in order to help relevant authorities gather information about illicit drug consumption and population health status. However, there are some prerequisites and uncertainties of the methodology that should be addressed for SCIM to reach its full potential in China.