scholarly journals Biodiversity and Spatial-Temporal Dynamics of Margalefidinium Species in Jiaozhou Bay, China

2021 ◽  
Vol 18 (21) ◽  
pp. 11637
Author(s):  
Shuya Liu ◽  
Mengjia Zhang ◽  
Yongfang Zhao ◽  
Nansheng Chen
Keyword(s):  
Temporal Dynamics ◽  
Harmful Algal Bloom ◽  
Jiaozhou Bay ◽  
Spatial Dynamics ◽  
High Genetic Diversity ◽  
Sequence Variations ◽  
Main Driver ◽  
Temporal And Spatial ◽  
Shed Light ◽  
Rule Out

Many Margalefidinium species are cosmopolitan harmful algal bloom (HAB) species that have caused huge economic and ecological damage. Despite extensive research on Margalefidinium species, the biodiversity and spatial-temporal dynamics of these species remain obscure. Jiaozhou Bay is an ideal area for HAB research, being one of the earliest marine survey areas in China. In this study, we carried out the first metabarcoding study on the temporal and spatial dynamics of Margalefidinium species using the 18S rDNA V4 region as the molecular marker and samples collected monthly at 12 sampling sites in Jiaozhou Bay in 2019. Two harmful Margalefidinium species (M. polykrikoides and M. fulvescens) were identified with potentially high genetic diversity (although we cannot rule out the possibility of intra-genome sequence variations). Both M. polykrikoides and M. fulvescens demonstrated strong temporal preference with a sharp peak of abundance in early autumn (September), but without showing strong location preference in Jiaozhou Bay. Our results revealed that temperature might be the main driver for their temporal dynamics. Knowledge of biodiversity and spatial-temporal dynamics of the Margalefidinium species may shed light on the understanding of mechanisms underlying strongly biased occurrences of Margalefidinium blooms recorded globally.

scholarly journals Episodic Dynamics of Tar Spot of Annual Lespedeza Within and Among Years

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 535-540 ◽  
Author(s):  
J. D. Mihail ◽  
R. L. McGraw ◽  
P. E. Verslues ◽  
S. J. Taylor
Keyword(s):  
Disease Severity ◽  
Temporal Dynamics ◽  
Disease Incidence ◽  
Spatial Dynamics ◽  
Silty Clay ◽  
Disease Dynamics ◽  
Silty Clay Loam ◽  
Row Crops ◽  
Tar Spot ◽  
Temporal And Spatial

The temporal and spatial dynamics of six tar spot epidemics were examined at two sites in mid-Missouri during 1990 to 1992. The sites, 48 km apart, differed in topography (flat versus slope), soil texture (silt loam versus silty-clay loam), and cropping history (orchard versus row crops). Temporal dynamics of disease incidence differed more among years than between sites. During 1990, temporal dynamics of the two epidemics followed a classic monotonic increase, whereas disease increase was episodic for the four epidemics observed during 1991 and 1992. Disease increase was associated with shading of the plant canopy or with the presence of dodder. Disease increase was related inversely to intercepted photosynthetically active radiation. Taken together, these observations suggest that factors that increase shading in the lespedeza canopy also increase tar spot incidence. For only two of the six epidemics was there a significant relationship between disease incidence (proportion of leaflets diseased) and disease severity (proportion of leaflet area diseased), with disease severity rarely exceeding 10%. These observations suggest that relatively low tar spot incidence may result in significant leaf losses, which would reduce lespedeza hay quality and yield. Further, this study demonstrates the importance of experimental repetition in both space and time to fully appreciate the range of disease dynamics for a single pathosystem.

scholarly journals Methodological Proposal for the Study of Temporal and Spatial Dynamics during the Late Period between the Middle Ebro and the Pyrenees

Information ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 366 ◽  
Author(s):  
Leticia Tobalina Pulido
Keyword(s):  
Spatial Databases ◽  
Temporal Dynamics ◽  
Methodological Approach ◽  
Spatial Dynamics ◽  
Descriptive Statistics ◽  
Late Period ◽  
Rural Settlements ◽  
Spatial And Temporal Dynamics ◽  
Temporal And Spatial ◽  
Space Occupation

The article I present here deals with the methodological approach carried out in my PhD in which I analyzed the spatial and temporal dynamics of late rural settlements during five centuries in the southern Pyrenees area, using geographic information systems, spatial databases, and descriptive statistics to establish models of space occupation and try to determine how these vary over the different centuries.

scholarly journals Temporal and Spatial Patterns of Harmful Algae Affecting Scottish Shellfish Aquaculture

2021 ◽  
Vol 8 ◽  
Author(s):  
Fatima Gianella ◽  
Michael T. Burrows ◽  
Sarah C. Swan ◽  
Andrew D. Turner ◽  
Keith Davidson
Keyword(s):  
Spatial Patterns ◽  
Environmental Variables ◽  
Temporal Dynamics ◽  
Harmful Algal Bloom ◽  
Temporal Frequency ◽  
Monitoring Program ◽  
Low Risk ◽  
Risk Level ◽  
Temporal And Spatial Patterns ◽  
Temporal And Spatial

Consistent patterns of Harmful Algal Bloom (HAB) events are not evident across the scientific literature, suggesting that local or regional variability is likely to be important in modulating any overall trend. This study summarizes Scotland-wide temporal and spatial patterns in a robust 15-year high temporal frequency time series (2006–2020) of the incidence of HABs and shellfish biotoxins in blue Mussels (Mytilus edulis), collected as part of the Food Standards Scotland (FSS) regulatory monitoring program. The relationship between the countrywide annual incidence of HAB events and biotoxins with environmental variables was also explored. Temporal patterns exhibited interannual variability, with no year-on-year increase, nor any correlation between annual occurrences. Within years, there was a summer increase in bloom frequency, peaking in July for Dinophysis spp. and Pseudo-nitzschia spp., and a plateau from May to July for Alexandrium spp. Temporal-spatial patterns were analyzed with multivariate statistics on data from monitoring sites aggregated monthly into 50-km grid cells, using Principal Component Analysis (PCA) and cluster K-means analysis. PCA analyses showed correlation between areas with similar temporal dynamics, identifying seasonality as one of the main elements of HAB variability with temporal-spatial patterns being explained by the first and second principal components. Similar patterns among regions in timing and magnitude of blooms were evaluated using K-means clusters. The analysis confirmed that the highest risk from HABs generally occurred during summer, but demonstrated that areas that respond in a similar manner (high or low risk) are not always geographically close. For example, the occurrence of the most prevalent HAB genus, Dinophysis spp., is similar countrywide, but there is a regional trend in risk level with “very-high” and “high” clusters located primarily on the southwest coast, the islands of the central and northern west coast and the Shetland Islands. “Early” and “late” blooms were also associated with certain areas and level of risk. Overall, high risk areas mainly face in a southwest direction, whilst low risk locations face a south or southeast direction. We found relatively few countrywide relationships between environmental variables and HABs, confirming the need for regional analysis to support HAB early warning.

scholarly journals Temporal and spatial dynamics in the apple flower microbiome in the presence of the phytopathogen Erwinia amylovora

2020 ◽  
Author(s):  
Zhouqi Cui ◽  
Regan B. Huntley ◽  
Quan Zeng ◽  
Blaire Steven
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Potential Interaction ◽  
Specific Gene ◽  
Large Populations ◽  
Single Flower ◽  
Temporal And Spatial ◽  
Blight Disease

AbstractPlant microbiomes have important roles in plant health and productivity. However, despite flowers being directly linked to reproductive outcomes, little is known about the microbiomes of flowers and their potential interaction with pathogen infection. Here, we investigated the temporal dynamics and spatial traits of the apple stigma microbiome when challenged with a phytopathogen Erwinia amylovora, the causal agent of fire blight disease. We profiled the microbiome from the stigmas of a single flower, greatly increasing the resolution at which we can characterize shifts in the composition of the microbiome. Individual flowers harbored unique microbiomes at the OTU level. However, taxonomic analysis of community succession showed a population gradually dominated by bacteria within the families Enterobacteriaceae and Pseudomonadaceae. Flowers inoculated E. amylovora established large populations of the phytopathogen, with pathogen specific gene counts of >3.0 × 107 in 90% of the flowers. Yet, only 42% of inoculated flowers later developed fire blight symptoms. This reveals pathogen amount on the stigma is not sufficient to predict disease outcome. Our data demonstrate that apple flowers represent an excellent model in which to characterize how plant microbiomes establish, develop, and interact with biological processes such as disease progression in an experimentally tractable plant organ.

scholarly journals Bus ridership and its determinants in Beijing: A spatial econometric perspective

2022 ◽  
Author(s):  
Jiaoe Wang ◽  
Yanan Li ◽  
Jingjuan Jiao ◽  
Haitao Jin ◽  
Fangye Du
Keyword(s):  
Spatial Autocorrelation ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Central Business District ◽  
Analytical Framework ◽  
Residential Areas ◽  
Basic Study ◽  
Factors Affecting ◽  
Temporal And Spatial ◽  
Business District

AbstractUnderstanding the temporal and spatial dynamics and determinants of public transport ridership play an important role in urban planning. Previous studies have focused on exploring the determinants at the station level using global models, or a local model, geographically weighted regression (GWR), which cannot reveal spatial autocorrelation at the global level. This study explores the factors affecting bus ridership considering spatial autocorrelation using the spatial Durbin model (SDM). Taking the community in Beijing as the basic study unit, this study aims to explore the temporal and spatial dynamics of bus ridership and identify its key determinants considering neighboring effects. The results show the following: (1) The temporal dynamics are quite distinct on weekdays and weekends as well as at different time slots of the day. (2) The spatial patterns of bus ridership varied across different time slots, and the hot areas are mainly located near the central business district (CBD), transport hubs, and residential areas. (3) Key determinants of bus ridership varied across weekends and weekdays and varied at different time slots per day. (4) The spatial neighboring effects had been verified. This study provides a common analytical framework for analyzing the spatiotemporal dynamics and determinants of bus ridership at the community level.

Temporal and spatial dynamics of pulse production in India

2017 ◽  
Author(s):  
International Food Policy Research Institute (IFPRI)
Keyword(s):  
Spatial Dynamics ◽  
Temporal And Spatial ◽  
Pulse Production

Spatial-temporal transmission dynamics and control of infectious diseases: Ebola virus disease (EVD) as a case study

2018 ◽  
Author(s):  
Cécile Viboud ◽  
Hélène Broutin ◽  
Gerardo Chowell
Keyword(s):  
Infectious Diseases ◽  
Disease Transmission ◽  
Ebola Virus ◽  
Temporal Dynamics ◽  
Virus Disease ◽  
Spatial Dynamics ◽  
Childhood Diseases ◽  
Middle Income ◽  
Theoretical Concepts ◽  
Dynamics And Control

Disentangling the spatial-temporal dynamics of infectious disease transmission is important to address issues of disease persistence, epidemic growth and optimal control. In this chapter, we review key concepts relating to the spatial-temporal dynamics of infectious diseases in meta-populations, whereby geographically separate subpopulations are connected by migration or mobility rates. We review the dynamics of colonization, persistence and extinction of emerging and recurrent pathogens in meta-populations; the role of demographic and environmental factors; and geographic heterogeneity in epidemic growth rate. We illustrate theoretical concepts by reviewing the spatial dynamics of childhood diseases and other acute infections in low- and middle-income countries, and provide a detailed description of the spatial-temporal dynamics of the 2014–16 Ebola epidemic in West Africa. We further discuss how increased availability of empirical data and recent methodological developments provide a deeper mechanistic understanding of transmission processes in space and time, and make recommendations for future work.

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