scholarly journals Structure features of Artemisia salsoloides Willd. (Asteraceae) coenotic populations in the Samara Region

2017 ◽  
Vol 6 (4) ◽  
pp. 41-47
Author(s):  
Tatyana Evgenievna Zenkina ◽  
Valentina Nikolaevna Ilina
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Research Area ◽  
Mathematical Methods ◽  
Ephedra Distachya ◽  
Random Placement

Artemisia salsoloides Willd. (Asteraceae) is included in the Red Books of Russia and various regions, including the Samara Region. It is characterized by a narrow confinement to the ecological and phytocenotic conditions of habitats. We studied the structure of the populations of the species. Traditional stationary methods for cenotic populations study were used. The spatial structure was estimated using modern mathematical methods, calculation of K (r) Ripley functions and Ripley cross-functions was performed. The phytogenic fields of species that grow together with A. salsoloides are characterized. The research area includes the Samara Predvolzhye and Samara Zavolzhye region. In the averaged age spectrum, the predominant group is the mature generative group, which is slightly inferior in number to the old generative fraction. The features of the spatial distribution of A. salsoloides in the population of Sernovodsky Shihan (Sergievsky District of the Samara Region) are studied. Here Artemisia is dominant in the community Artemisia salsoloides Willd. + Hedysarum grandiflorum Pall. - Stipa korshinskyi Roshev. The density of A. salsoloides in the studied coenopopulation is 1,7 individuals per 1 m. Pregenerative individuals are randomly distributed. The generative individuals repel each other for a distance of 0,2 m, followed by random placement. There is a tendency to form aggregations of 0,6 m. The estimation of the mutual placement of A. salsoloides and Stipa korshinskyi , as well as Oxytropis floribunda , indicates a slight repulsion of individuals at a distance of 0,2 m, with Hedysarum grandiflorum - a significant repulsion at a distance of 0,4 m with the subsequent random placement of all representatives. The specimens of A. salsoloides and Ephedra distachya , as well as Scabiosa isetensis , have a random placement.

Social Learning

2013 ◽  
Author(s):  
William Hoppitt ◽  
Kevin N. Laland
Keyword(s):  
Spatial Distribution ◽  
Social Learning ◽  
Learning Strategies ◽  
Cognitive Neuroscience ◽  
Cultural Evolution ◽  
Experimental Psychology ◽  
Academic Disciplines ◽  
Mathematical Methods ◽  
Indispensable Tool ◽  
Social Learning Strategies

Many animals, including humans, acquire valuable skills and knowledge by copying others. Scientists refer to this as social learning. It is one of the most exciting and rapidly developing areas of behavioral research and sits at the interface of many academic disciplines, including biology, experimental psychology, economics, and cognitive neuroscience. This book provides a comprehensive, practical guide to the research methods of this important emerging field. It defines the mechanisms thought to underlie social learning and demonstrate how to distinguish them experimentally in the laboratory. It presents techniques for detecting and quantifying social learning in nature, including statistical modeling of the spatial distribution of behavior traits. It also describes the latest theory and empirical findings on social learning strategies, and introduces readers to mathematical methods and models used in the study of cultural evolution. This book is an indispensable tool for researchers and an essential primer for students.

scholarly journals Advanced 3D Cell Culture Techniques in Micro-Bioreactors, Part II: Systems and Applications

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Brigitte Altmann ◽  
Christoph Grün ◽  
Cordula Nies ◽  
Eric Gottwald
Keyword(s):  
Cell Culture ◽  
Spatial Distribution ◽  
3D Cell Culture ◽  
Research Area ◽  
Cell Culture Techniques ◽  
Culture Techniques ◽  
Cell Functions ◽  
Matrix Interactions ◽  
Definition Of ◽  
Extracellular Matrix Interactions

In this second part of our systematic review on the research area of 3D cell culture in micro-bioreactors we give a detailed description of the published work with regard to the existing micro-bioreactor types and their applications, and highlight important results gathered with the respective systems. As an interesting detail, we found that micro-bioreactors have already been used in SARS-CoV research prior to the SARS-CoV2 pandemic. As our literature research revealed a variety of 3D cell culture configurations in the examined bioreactor systems, we defined in review part one “complexity levels” by means of the corresponding 3D cell culture techniques applied in the systems. The definition of the complexity is thereby based on the knowledge that the spatial distribution of cell-extracellular matrix interactions and the spatial distribution of homologous and heterologous cell–cell contacts play an important role in modulating cell functions. Because at least one of these parameters can be assigned to the 3D cell culture techniques discussed in the present review, we structured the studies according to the complexity levels applied in the MBR systems.

Plant induced spatial distribution of nematodes in a semi-natural grassland

Nematology ◽  
2007 ◽  
Vol 9 (1) ◽  
pp. 131-142 ◽  
Author(s):  
Maria Viketoft
Keyword(s):  
Multivariate Analysis ◽  
Spatial Distribution ◽  
Spatial Structure ◽  
Plant Species ◽  
Trifolium Repens ◽  
Individual Plant ◽  
Nematode Communities ◽  
The Family ◽  
Natural Grassland ◽  
Nematode Fauna

AbstractThis study describes the nematode community in a semi-natural grassland and investigates if certain individual plant species can cause a spatial structure in the nematode fauna. Nematode communities were analysed in soil under Trifolium repens, Festuca ovina and from randomly taken samples. Seventy-nine nematode genera were identified. Some of the species found have not previously been reported from Sweden. Multivariate analysis separated the nematode communities associated with the two selected plant species from each other, and several individual nematode genera differed in abundance between the plant species. Trifolium repens supported greater populations of the plant feeder Tylenchorhynchus and the bacterial feeders Eucephalobus, Chiloplacus, Eumonhystera and Panagrolaimus, but fewer numbers of the bacterial feeder Achromadora. Soil under F. ovina contained more nematodes from the family Alaimidae. A comparison is given with other studies from grassland systems in Sweden.

scholarly journals A short geostatistical study of the three-dimensional spatial structure of fumonisins in stored maize

2010 ◽  
Vol 3 (1) ◽  
pp. 95-103 ◽  
Author(s):  
M. Rivas Casado ◽  
D. Parsons ◽  
N. Magan ◽  
R. Weightman ◽  
P. Battilani ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Spatial Correlation ◽  
Three Dimensional ◽  
Sample Collection ◽  
Data Set ◽  
Research Areas ◽  
Geostatistical Approach ◽  
Sampling Protocols ◽  
Current Sample

The heterogeneous three-dimensional spatial distribution of mycotoxins has proven to be one of the main limitations for the design of effective sampling protocols. Current sample collection protocols for mycotoxins have been designed to estimate the mean concentration and fail to characterise the spatial distribution of the mycotoxin concentration due to the aggregation of the incremental samples. Geostatistical techniques have been successfully applied to overcome similar problems in many research areas. However, little work has been developed on the use of geostatistics for the design of sampling protocols for mycotoxins. This paper focuses on the analysis of the two and three-dimensional spatial structure of fumonisins B1 (FB1) and B2 (FB2) in maize in a bulk store using a geostatistical approach and on how results help determine the number and location of incremental samples to be collected. The spatial correlation between FB1 and FB2, as well as between the number of kernels infected and the level of contamination was investigated. For this purpose, a bed of maize was sampled at different depths to generate a unique three-dimensional data set of FB1 and FB2. The analysis found no clear evidence of spatial structure in either the two-dimensional or three-dimensional analyses. The number of Fusarium infected kernels was not a good indicator for the prediction of fumonisin concentration and there was no spatial correlation between the concentrations of the two fumonisins.

scholarly journals Spatial Structure Characteristics of Slope Farmland Quality in Plateau Mountain Area: A Case Study of Yunnan Province, China

2020 ◽  
Vol 12 (17) ◽  
pp. 7230
Author(s):  
Zhengfa Chen ◽  
Dongmei Shi
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Yunnan Province ◽  
Hot Spot ◽  
Mountain Region ◽  
Cold Spot ◽  
Structure Characteristics ◽  
Spot Area ◽  
Slope Farmland ◽  
Southern Fringe

As an important part of farmland, the slope farmland is widely distributed in the central and western plateau mountain region in China. It is necessary to scientifically evaluate the slope farmland quality (SFQ) and analyze the spatial structure characteristics of SFQ to ensure reasonable utilization and partition protection of slope farmland resources. This paper takes the typical plateau mountain region—Yunnan Province in China—as an example and systematically identifies the leading factors of SFQ. The sloping integrated fertility index (SIFI) is adopted to reflect the SFQ. The evaluation system is built to quantitatively evaluate the SFQ and the spatial structure characteristics of SFQ were analyzed by a geostatistical model, autocorrelation analysis and spatial cold–hot spot analysis. The results show that the SFQ indexes in Yunnan Province are between 0.36 and 0.81, with a mean of 0.59. The SFQ grade is based on sixth-class, fifth-class, seventh-class and fourth-class land. The SFQ indexes present a normal spatial distribution, and the Gaussian model fits well with the semi-variance function of the spatial distribution of SFQ indexes. Furthermore, the spatial distribution of SFQ indexes is moderately autocorrelated. The structural factors play a major role in the spatial heterogeneity of SFQ indexes, but the influence of random factors should not be ignored. The spatial distribution of SFQ grades has a significant spatial aggregation characteristic, and the types of local indicators of spatial association (LISA) are based on high–high (HH) aggregation and low–low (LL) aggregation. The cold spot and hot spot distributions of SFQ grades display the significant spatial difference. The hot spot area is mainly distributed in Central Yunnan and the Southern Fringe, while the cold spot area mainly distributes in the Northeastern Yunnan, Northwestern Yunnan and Southwestern Yunnan. This study could provide a scientific basis for SFQ management and ecological environment protection in the plateau mountain region.

scholarly journals Production of highly ionized plasma by micro-dot array irradiation and its application to compact X-ray lasers

2002 ◽  
Vol 20 (1) ◽  
pp. 73-77 ◽  
Author(s):  
NAOHIRO YAMAGUCHI ◽  
CHIEMI FUJIKAWA ◽  
KAZUNOBU OKASAKA ◽  
TAMIO HARA
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Pulse Train ◽  
Production Method ◽  
Point Of View ◽  
Rapid Expansion ◽  
Laser Generation ◽  
Plasma Production ◽  
X Ray ◽  
Laser Gain

A plasma production method using the irradiation of an array of small spots has been investigated from the point of view of soft X-ray laser generation in the recombining plasma scheme pumped by a pulse-train laser. The expansion geometry of highly ionized ions produced by the micro-dot array irradiation method has been measured and compared with that by a simple line irradiation. Spatial distribution of gain coefficients of the Li-like Al ion transition lines have also been measured for both irradiation methods. Highly ionized ions were observed to spread wider in the micro-dot array irradiation method. It is expected that rapid expansion and efficient cooling are achieved in plasmas produced by the micro-dot array irradiation method, which is consistent with the experimental results on the spatial structure of the X-ray laser gain region.

scholarly journals Linking Spatial Structure and Community-Level Biotic Interactions through Cooccurrence and Time Series Modeling of the Human Intestinal Microbiota

mSystems ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
Eric J. de Muinck ◽  
Knut E. A. Lundin ◽  
Pål Trosvik
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Gut Microbiome ◽  
Spatial Organization ◽  
Biotic Interactions ◽  
Community Level ◽  
Human Gut ◽  
Microbial Composition ◽  
Fecal Samples ◽  
Human Gut Microbiome

ABSTRACT The human gut microbiome is the subject of intense study due to its importance in health and disease. The majority of these studies have been based on the analysis of feces. However, little is known about how the microbial composition in fecal samples relates to the spatial distribution of microbial taxa along the gastrointestinal tract. By characterizing the microbial content both in intestinal tissue samples and in fecal samples obtained daily, we provide a conceptual framework for how the spatial structure relates to biotic interactions on the community level. We further describe general categories of spatial distribution patterns and identify taxa conforming to these categories. To our knowledge, this is the first study combining spatial and temporal analyses of the human gut microbiome. This type of analysis can be used for identifying candidate probiotics and designing strategies for clinical intervention. The gastrointestinal (GI) microbiome is a densely populated ecosystem where dynamics are determined by interactions between microbial community members, as well as host factors. The spatial organization of this system is thought to be important in human health, yet this aspect of our resident microbiome is still poorly understood. In this study, we report significant spatial structure of the GI microbiota, and we identify general categories of spatial patterning in the distribution of microbial taxa along a healthy human GI tract. We further estimate the biotic interaction structure in the GI microbiota, both through time series and cooccurrence modeling of microbial community data derived from a large number of sequentially collected fecal samples. Comparison of these two approaches showed that species pairs involved in significant negative interactions had strong positive contemporaneous correlations and vice versa, while for species pairs without significant interactions, contemporaneous correlations were distributed around zero. We observed similar patterns when comparing these models to the spatial correlations between taxa identified in the adherent microbiota. This suggests that colocalization of microbial taxon pairs, and thus the spatial organization of the GI microbiota, is driven, at least in part, by direct or indirect biotic interactions. Thus, our study can provide a basis for an ecological interpretation of the biogeography of the human gut. IMPORTANCE The human gut microbiome is the subject of intense study due to its importance in health and disease. The majority of these studies have been based on the analysis of feces. However, little is known about how the microbial composition in fecal samples relates to the spatial distribution of microbial taxa along the gastrointestinal tract. By characterizing the microbial content both in intestinal tissue samples and in fecal samples obtained daily, we provide a conceptual framework for how the spatial structure relates to biotic interactions on the community level. We further describe general categories of spatial distribution patterns and identify taxa conforming to these categories. To our knowledge, this is the first study combining spatial and temporal analyses of the human gut microbiome. This type of analysis can be used for identifying candidate probiotics and designing strategies for clinical intervention. Author Video: An author video summary of this article is available.

scholarly journals Influence of the Spatial Distribution Pattern of Buildings on the Distribution of PM2.5 Concentration

2021 ◽  
Author(s):  
Zhixuan Zhang ◽  
Baoyan Shan ◽  
Qikai Lin ◽  
Yanqiu Chen ◽  
Xinwei Yu
Keyword(s):  
Spatial Distribution ◽  
Standard Deviation ◽  
Spatial Structure ◽  
Distribution Pattern ◽  
Distribution Patterns ◽  
Spatial Distribution Pattern ◽  
Urban Spatial Structure ◽  
Coverage Ratio ◽  
The Mean ◽  
Pm2.5 Concentration

Abstract The spatial distribution pattern of buildings is an entry point for controlling the diffusion of pollution particles at an urban spatial structure scale. In this study, we adopted ordinary kriging interpolation and other methods to study the spatial distribution pattern of PM2.5 and constructed urban spatial structure indexes based on building distribution patterns to reveal the influence of building spatial distribution patterns on PM2.5 concentration across the study area and at different elevations. The present study suggests that: (1) Topographic elevation is an important factor influencing the distribution of PM2.5; the correlation coefficient reaches −0.761 and exceeds the 0.001 confidence level. As the elevation increases, the urban spatial structure indexes show significant correlations with PM2.5, and the regularity becomes stronger. (2) The PM2.5 concentration is negatively correlated with the mean and standard deviation of the DEM, the mean and maximum absolute building height, the outdoor activity area, and the average distance between adjacent buildings; and is positively correlated with the sum of the building base area, the building coverage ratio, the space area, the building coverage ratio, the space occupation ratio, and the sum of the building volume. These urban spatial structure indexes are important factors affecting PM2.5 concentration and distribution and should be considered in urban planning. (3) Spatio-temporal differences in PM2.5 concentration and distribution were found at different elevation and time ranges. Indexes, such as the average building height, the average building base area, the sum of the building volume, and the standard deviation of building volume experienced significant changes. Higher PM2.5 concentration yielded a more significant influence of urban spatial structure indexes on PM2.5 distribution. More discrete spatial distributions of PM2.5 yielded weaker correlations between PM2.5 concentrations and the urban spatial structure indexes.

scholarly journals Migración internacional en la Ciudad de Buenos Aires: un análisis socioespacial de su distribución según tipos de hábitat / International Migration in the City of Buenos Aires: A Socio-Spatial Analysis of its Distribution by Types of Habitat

2015 ◽  
Vol 30 (2) ◽  
pp. 327 ◽  
Author(s):  
Gabriela Mera ◽  
Mariana Marcos ◽  
María Mercedes Di Virgilio
Keyword(s):  
Spatial Distribution ◽  
Quantitative Analysis ◽  
Spatial Analysis ◽  
Spatial Structure ◽  
International Migration ◽  
Buenos Aires ◽  
Foreign Population ◽  
Living Space ◽  
Urban Contexts ◽  
The City

En el marco de la pregunta por las diferencias y desigualdades metropolitanas, este artículo se propone estudiar la distribución espacial de la población extranjera en la Ciudad de Buenos Aires a partir de una tipología de contextos urbanos o tipos de hábitat, definidos en función del periodo de urbanización y la forma de producción del espacio habitacional. Tomando como fuente investigaciones previas y datos del Censo Nacional de Población, Hogares y Viviendas 2010, se realiza un análisis cuantitativo que indaga cómo se articula la diferenciación por condición migratoria con estos entornos que conforman la estructura socioespacial de la ciudad.Abstract:Within the framework of the question of metropolitan differences and inequalities, this article seeks to study the spatial distribution of the foreign population in the City of Buenos Aires on the basis of a typology of urban contexts or types of habitat, defined in terms of the period of urbanization and the form of production of the living space. Based on previous research and data from the National Census of Population and Housing 2010, a quantitative analysis is undertaken to explore how differentiation by migratory condition is linked to these environments that comprise the socio-spatial structure of the city.

scholarly journals Study on the Influence of Road Network on the Spatial Distribution of Tourism Resources – A Case Study of the Sichuan-Tibet Scenic Byway

CONVERTER ◽  
2021 ◽  
pp. 242-256
Author(s):  
Bo Zhang, Boming Tang, Liangyu Zhou, Ke Huang
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Road Network ◽  
Spillover Effect ◽  
Global Scale ◽  
Matthew Effect ◽  
Regional Tourism ◽  
Tourism Resources ◽  
Positive Direct ◽  
Spatial Spillover Effect

Objectives: The Sichuan-Tibet Scenic Byway is one of the most well-known scenic byway in China. Researching on the mechanism of action between the routes and tourism resources nodes of the Sichuan-Tibet Scenic Byway network, will benefit the Sichuan-Tibet Scenic Byway’s development by changing the development patterns of the Scenic Byway from “point-line” to network, and will be helpful to promote the integration of tourism resources along the route, furthermore to construct the Sichuan-Tibet Scenic Byway as a destination of all-for-one tourism. Methods: Based on the spatial design network analysis (sDNA model), GIS spatial analysis and other methods, the current study analyzed regional tourism resources and the spatial characteristics of road network morphology along the Sichuan-Tibet Scenic Byway, and explored the influence of road network forms on the spatial distribution of tourism resources and its spatial spillover effect by combining with spatial econometric model. Results: The distribution pattern of tourism resources along the Sichuan-Tibet Scenic Road is “dense at both ends and sparse in the middle”, and the “Matthew Effect” is significant. The spatial structure of road network varies significantly at different scales; at the global scale, the spatial structure shows “one axis and two cores”, at the local scale, it shows "two cores and multiple nodes"; Every road network variable has spatial spillover effect on the distribution of tourism resources. The global scale Closeness (NQPDE) has significant positive direct effect and negative spillover effect on tourism resources distribution. Every 1% increase in local closeness will promote an increase of 0.811% and -0.99% in the distribution of local and adjacent tourism resources, respectively. Betwenness (TPBTE) has significant positive direct effect and positive spillover effect on the distribution of tourism resources. Every 1% increase in local betwenness will promote an increase of 0.337% and 1.860% in the distribution of local and adjacent tourism resources, respectively. Conclusions: The distribution of tourism resources along the Sichuan-Tibet Scenic Byway’s shows significant “Matthew Effect”. The spatial structure of the Sichuan-Tibet Scenic Byway network varies significantly at different scales. At the global scale, firstly, it has better accessibility and centrality, which is more attractive to the global road network; secondly, the road network is more traversable, which means it bears greater traffic volume, which is more inconsistent with the actual High-grade highways bear more long-distance traffic flows to match; thirdly, they distribution of tourism resources are generally in line with the spatial orientation of National Highway 318. Traffic conditions are an indispensable and important condition for promoting the healthy development of the distribution of regional tourism resources. Closeness (NQPDE) is an important factor affecting the spatial distribution and growth potential of local tourism resources, but it will relatively weaken the development opportunities and cost advantages of tourism resources in neighboring regions, and inhibit the distribution of tourism resources in neighboring regions. Betwenness (TPBtE) is the key to promote global tourism, especially the rapid transportation system can accelerate the integration and reconstruction of tourism elements. This study aims to promote the sound development of the Sichuan-Tibet Scenic Byway network layout and the distribution of regional tourism resources in the post-epidemic era, and to provide reference for the spatial planning of tourism transportation and the optimal allocation of tourism elements.

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