Extraction of spatial distribution information and migration direction of diphtheria aconitum based on UAV images

Atmospheric conditions are known to affect flight propensity, behaviour during flight, and migration route in birds. Yet, the effects of fog have only been rarely studied, although they could disrupt orientation and hamper the accomplishment of the journey. Soaring migrants modulate their flight speed and direction in relation to the wind vector to optimize the cost of transport. Fog could limit the visibility of migrating birds such that they might not be able to detect landmarks that guide them during their journey. Consequently, landmark-based orientation, as well as adjustments of flight speed and direction in relation to wind conditions, could be jeopardized when flying in fog. Using a radar system that operated in a migration bottleneck (Strait of Messina, Italy), we studied the behaviour of soaring birds under variable wind and fog conditions over two consecutive springs (2016 and 2017), discovering that migrating birds exhibited a wider scatter of flight directions and responded differently to wind conditions under fog conditions. Birds flying through fog deviated more from the mean migration direction and increased their speed with increasing crosswinds. In addition, airspeed and groundspeed increased in the direction of the crosswind, causing a lateral drift of the individuals. Furthermore, the response to tailwind was opposite to that predicted by optimal migration theory. Our findings represent the first quantitative empirical evidence of flight behaviour changes when birds migrate through fog and explain why low visibility conditions could risk their migration journey.

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Penetration and migration routes of Schistosoma japonicum miracidia in the snail Oncomelania hupensis

Parasitology ◽

10.1017/s003118200005931x ◽

1991 ◽

Vol 103 (1) ◽

pp. 77-83 ◽

Cited By ~ 2

Author(s):

M. Y. Xia ◽

J. Jourdane

Keyword(s):

Spatial Distribution ◽

Schistosoma Japonicum ◽

Histological Study ◽

Circulatory System ◽

Selective Advantage ◽

Oncomelania Hupensis ◽

Migration Routes ◽

Branchial Cavity ◽

And Migration ◽

Host Parasite

The routes of penetration and the strategies of invasion of Schistosoma japonicum miracidia in the snail vector Oncomelania hupensis were observed in a histological study. In all species of the genus Schistosoma, it is usually assumed that the miracidia achieve penetration through the tegument. Our results showed that at least 57% of S. japonicum miracidia penetrated the snail by natural openings (branchial cavity, mouth and rectum). Throughout the invasion phase, the larvae were observed in all the tissues and organs with the exception of the genital gland. The spatial distribution of parasites in the snail revealed that the migration towards the visceral organs such as the kidney, heart and sinuses (which are the most usual microhabitats of the mother sporocysts of S. japonicum) appeared to take place via the circulatory system. Using natural openings as routes for penetration probably provides a selective advantage in a host–parasite system in which the target mollusc is amphibious: we presume that the miracidia inside these natural openings are protected against desiccation when the snail leaves the water, and that they can subsequently invade the tissues.

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Contact guidance requires spatial control of leading-edge protrusion

Molecular Biology of the Cell ◽

10.1091/mbc.e16-11-0769 ◽

2017 ◽

Vol 28 (8) ◽

pp. 1043-1053 ◽

Cited By ~ 33

Author(s):

G. R. Ramirez-San Juan ◽

P. W. Oakes ◽

M. L. Gardel

Keyword(s):

Cell Shape ◽

Spatial Organization ◽

Leading Edge ◽

Contact Guidance ◽

Spatial Constraints ◽

Migration Direction ◽

Line Spacing ◽

Geometric Cues ◽

And Migration

In vivo, geometric cues from the extracellular matrix (ECM) are critical for the regulation of cell shape, adhesion, and migration. During contact guidance, the fibrillar architecture of the ECM promotes an elongated cell shape and migration along the fibrils. The subcellular mechanisms by which cells sense ECM geometry and translate it into changes in shape and migration direction are not understood. Here we pattern linear fibronectin features to mimic fibrillar ECM and elucidate the mechanisms of contact guidance. By systematically varying patterned line spacing, we show that a 2-μm spacing is sufficient to promote cell shape elongation and migration parallel to the ECM, or contact guidance. As line spacing is increased, contact guidance increases without affecting migration speed. To elucidate the subcellular mechanisms of contact guidance, we analyze quantitatively protrusion dynamics and find that the structured ECM orients cellular protrusions parallel to the ECM. This spatial organization of protrusion relies on myosin II contractility, and feedback between adhesion and Rac-mediated protrusive activity, such that we find Arp2/3 inhibition can promote contact guidance. Together our data support a model for contact guidance in which the ECM enforces spatial constraints on the lamellipodia that result in cell shape elongation and enforce migration direction.

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Reducing 3-D acquisition footprint for 3-D DMO and 3-D prestack migration

Geophysics ◽

10.1190/1.1444417 ◽

1998 ◽

Vol 63 (4) ◽

pp. 1177-1183 ◽

Cited By ~ 47

Author(s):

Anat Canning ◽

Gerald H. F. Gardner

Keyword(s):

Spatial Distribution ◽

Velocity Analysis ◽

Amplitude Variation ◽

Amplitude Variation With Offset ◽

Prestack Migration ◽

Avo Analysis ◽

And Migration

The acquisition patterns of 3-D surveys often have a significant effect on the results of dip moveout (DMO) or prestack migration. When the spatial distribution of input traces is irregular, results from DMO and migration are contaminated by artifacts. In many cases, the footprint of the acquisition patterns can be seen on the migrated section and may result in incorrect interpretation. This phenomena also has a very significant effect on the feasibility of conducting amplitude variation with offset (AVO) analysis after 3-D prestack migration or after 3-D DMO, and also may affect velocity analysis. We propose a simple enhancement to migration and DMO programs that acts to minimize acquisition artifacts.

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“Taiga” and “River” Components in the Nanai Socio-Tribal Organization at Lake Bolon, the Lower Amur

Archaeology Ethnology and Anthropology of Eurasia ◽

10.17746/1563-0110.2019.47.2.131-139 ◽

2019 ◽

Vol 47 (2) ◽

pp. 131-139

Author(s):

O. V. Maltseva

Keyword(s):

Spatial Distribution ◽

Social Relationships ◽

Field Data ◽

Settlement Pattern ◽

Variation Method ◽

Small Populations ◽

Mutual Aid ◽

And Migration ◽

Economic Specialization ◽

Kinship Ties

This study explores the socio-tribal organization of the Nanai living near Lake Bolon, with reference to environment and migration, using published and unpublished sources, S.K. Patkanov’s statistical materials, and our field data. We employ D.N. Anuchin’s spatial distribution and variation method for reconstructing the settlement pattern and assessing the socio-tribal structure with regard to the contacts between sedentary and nomadic populations. The Lake Bolon area is a transit territory traversed by reindeer herders and hunters on their way to the Pacifi c coast, and the place from whence the Amur natives migrated in various directions. This is where the herding, hunting, and fi shing traditions merged. The Nanai settlers selected places that matched their economic specialization, and these places eventually acquired symbolic functions. Small populations merged, adapted, and borrowed the names of large territorial groups. Marital contacts and kinship ties are analyzed in detail. Social relationships were regulated by the Dokha institute: clans concluded alliances based on mutual aid. Intermarriage was allowed only after several generations. The analysis of exogamous clans such as Hodzher, Odzyal, Kileh, and Beldy, which had settled near the lake, and the interviewing of the natives suggest that along with the Tungus patrilineal kinship, the matrilineal system predating the Tungus expansion was still practiced.

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Identifying Seasonal Accumulation of Soil Salinity with Three-Dimensional Mapping—A Case Study in Cold and Semiarid Irrigated Fields

Sustainability ◽

10.3390/su12166645 ◽

2020 ◽

Vol 12 (16) ◽

pp. 6645

Author(s):

Qianqian Liu ◽

Gulimire Hanati ◽

Sulitan Danierhan ◽

Guangming Liu ◽

Yin Zhang ◽

...

Keyword(s):

Spatial Distribution ◽

Soil Salinity ◽

Saline Soil ◽

Soil Depth ◽

Three Dimensional ◽

Soil Surface ◽

Distribution Maps ◽

Different Seasons ◽

And Migration ◽

Accumulation Trend

Soil salinity is an active and complex part of soil property in arid and semiarid irrigation areas that restricts the sustainability of agriculture production. Knowledge of seasonal distributions and migration of soil salinity is important for the management of agriculture. In this study, three-dimensional (3-D) geostatistical methods were used to construct seasonal 3-D spatial distribution maps of soil salinity, and then the quantitative analysis methods were used to study the seasonal accumulation patterns of soil salinity for the 0–150 cm soil depth in cold and semiarid irrigated rice fields. The results revealed that there were different spatial distribution and migration patterns of soil salinity in autumn 2015, spring 2016, autumn 2016, and spring 2017. The migration of soil salinity had a dispersion trend from autumn to spring, and the area of non-saline soil increased. Whereas there was an accumulation trend from spring to autumn, and the area of non-saline soil decreased. There were about 10–20% of the study area had experienced transitional changes of different soil salinity levels in different seasons. The correlation coefficient showed that there were significant positive correlations among the five depth increments (30 cm) in different seasons, and the correlations of soil salinity were higher in adjacent layers than in nonadjacent layers. The ECe values were higher in the topsoil (0–30 cm) and deeper subsoil (120–150 cm), indicating that soil soluble salts accumulated in the soil surface due to evaporation and accumulated in the bottom due to leaching and drainage. Microtopography was the major factor influencing spatial distribution of soil salinity in different seasons. The ECe values were generally higher in the swales or in areas with rather poor drainage, whereas the values were lower in relatively higher-lying slopes or that were well-drained. The results provide theoretical basis and reference for studying the variation of seasonal soil salinity in irrigated fields.

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Estimating Caprock Impact on CO2 Migration in the Gassum Formation Using 2D Seismic Line Data

Transport in Porous Media ◽

10.1007/s11242-021-01622-1 ◽

2021 ◽

Author(s):

Odd Andersen ◽

Anja Sundal

Keyword(s):

Seismic Data ◽

Large Scale ◽

Flow Simulation ◽

Small Scale ◽

Model Parameters ◽

Seismic Line ◽

Migration Direction ◽

3D Data ◽

And Migration ◽

The Impact

AbstractRealizable CO2 storage potential for saline formations without closed lateral boundaries depends on the combined effects of physical and chemical trapping mechanisms to prevent long-term migration out of the defined storage area. One such mechanism is the topography of the caprock surface, which may retain CO2 in structural pockets along the migration path. Past theoretical and modeling studies suggest that even traps too small to be accurately described by seismic data may play a significant role. In this study, we use real but scarce seismic data from the Gassum Formation of the Norwegian Continental shelf to estimate the impact of topographical features of the top seal in limiting CO2 migration. We seek to estimate the amount of macro- and sub-scale trapping potential of the formation based on a few dozen interpreted 2D seismic lines and identified faults. We generate multiple high-resolution realizations of the top surface, constructed to be faithful to both large-scale topography and small-scale statistical properties. The structural trapping and plume retardation potential of these top surfaces is subsequently estimated using spill-point (static) analysis and dynamical flow simulation. By applying these techniques on a large ensemble of top surface realizations generated using a combination of stochastic realizations and systematic variation of key model parameters, we explore the range of possible impacts on plume advancement, physical trapping and migration direction. The stochastic analysis of trapping capacity and retardation efficiency in statistically generated, sub-seismic resolution features may also be applied for surfaces generated from 3D data.

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Spatial distribution of heavy metals in the West Dongting Lake floodplain, China

Environmental Science Processes & Impacts ◽

10.1039/c9em00536f ◽

2020 ◽

Vol 22 (5) ◽

pp. 1256-1265 ◽

Cited By ~ 1

Author(s):

Dong Peng ◽

Ziyu Liu ◽

Xinyue Su ◽

Yaqian Xiao ◽

Yuechen Wang ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Spatial Distribution ◽

Metal Contamination ◽

Heavy Metal Contamination ◽

Dongting Lake ◽

Migration Route ◽

The West ◽

Rare And Endangered ◽

And Migration

The protection of Dongting Lake is important because it is an overwintering and migration route for many rare and endangered birds of East Asia and Australasia, but an assessment of heavy metal contamination in West Dongting Lake is lacking.

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Spatial distribution of outbreak of locust swarms: a geographical analysis of vulnerability and preventions in India

Sustainability Agri Food and Environmental Research ◽

10.7770/safer-v0n0-art2262 ◽

2020 ◽

Author(s):

Bindhy Wasini Pandey ◽

Pushalal Ganesh ◽

Rajan Maurya ◽

Usha K Patak ◽

Roosen Kumar ◽

...

Keyword(s):

Spatial Distribution ◽

Agricultural Sector ◽

Prevention Measures ◽

Environmental Consequences ◽

Transient Nature ◽

Livelihood Options ◽

The World ◽

Current Outbreak ◽

And Migration ◽

The Many

Current outbreak of locust swarms in the different parts of the world has also emerged as a big problem for the Indian agricultural sector and associated livelihood options. Being known for its transient nature, the locust swarms containing millions of locusts. These swarms are, therefore, one of the most dangerous pests in the world that may have a disastrous impact on food, food crops, fodder and food security around the world. The outbreak has been historically noticed in several regions of the world which effected the agriculture system of the many countries and major cause for the slowdown in the economy. This paper examines the origin and migration trends of locust swarms in the world in general and India in particular. Also paper evaluates the recent outbreak of locusts in India along with assessing its devastating impact on Indian Agricultural Sector and the track routes of the swarms in India in different months. In the end, the paper highlights preventive measures that have been used in monitoring and preventions of locust swarms. The outbreaks of locust in India is not new, but have been encountered in the past too. The intensity and number of hives and migratory frequency is increasing with time. The Area, magnitude and impacts of the locust swarms is also growing with time and space. Since the outbreak results in social, economic and environmental consequences, therefore, adequate measures and planning are required to tackle the crisis.Keywords: Locusts, Swarms, Vulnerability, Prevention Measures, Spatial distribution

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