scholarly journals Histological and biochemical changes in Pinus spp. seeds during germination and post-germinative growth: triacylglycerol distribution and catalase activity

2000 ◽  
Vol 27 (12) ◽  
pp. 1109
Author(s):  
Marie-Noëlle Jordy ◽  
Susanna Danti ◽  
Jean-Michel Favre ◽  
Milvia Luisa Raccchi
Keyword(s):  
Apical Meristem ◽  
Temporal Evolution ◽  
Peripheral Zone ◽  
Pinus Pinaster Ait ◽  
Storage Area ◽  
Spatio Temporal ◽  
Mother Cells ◽  
Pinus Spp ◽  
Specific Lipid

The spatio-temporal evolution of catalase (CAT) activity and triacylglycerol distribution was investigated in seeds and seedlings from Pinus pinaster Ait., P. pinea L. and P. radiata D. Don during germination and post-germination. The high amount of triacylglycerols contained in the whole dehydrated embryo from the three species was progressively depleted, first, in the radicle and then in hypocotyl and cotyledons during post-germinative growth. In parallel, histological localisation of CAT activity and the quantitative analysis confirmed the involvement of this enzyme in cell detoxification from peroxide released during the intense lipid breakdown. Two isozymes, CAT-1 and CAT-2, were identified during post-germinative growth. Both were particularly active in the hypocotyl and radicle, while CAT-2 was specifically active in the photosynthetic tissues. These results emphasise that CAT activity is also independent from lipid metabolism in certain tissues. The role of each isoenzyme is discussed in connection with the metabolic changes occurring during seed germination and seedling growth. Special attention is given to the role of the shoot apex in triacylglycerol storage and breakdown. Central mother cells have been shown as a specific lipid storage area of the shoot apical meristem, in contrast with the peripheral zone in which lipid reserves were always reduced.

scholarly journals ON SPATIAL CONSENSUS FORMATION: IS THE SZNAJD MODEL DIFFERENT FROM A VOTER MODEL?

2003 ◽  
Vol 14 (10) ◽  
pp. 1331-1354 ◽  
Author(s):  
LAXMIDHAR BEHERA ◽  
FRANK SCHWEITZER
Keyword(s):  
Computer Simulations ◽  
Nearest Neighbor ◽  
Temporal Evolution ◽  
Relaxation Times ◽  
Nearest Neighbors ◽  
Voter Model ◽  
Consensus Formation ◽  
Spatio Temporal ◽  
Update Rules

In this paper, we investigate the so-called "Sznajd Model" (SM) in one dimension, which is a simple cellular automata approach to consensus formation among two opposite opinions (described by spin up or down). To elucidate the SM dynamics, we first provide results of computer simulations for the spatio-temporal evolution of the opinion distribution L(t), the evolution of magnetization m(t), the distribution of decision times P(τ) and relaxation times P(μ). In the main part of the paper, it is shown that the SM can be completely reformulated in terms of a linear voter model (VM), where the transition rates towards a given opinion are directly proportional to frequency of the respective opinion of the second-nearest neighbors (no matter what the nearest neighbors are). So, the SM dynamics can be reduced to one rule, "Just follow your second-nearest neighbor". The equivalence is demonstrated by extensive computer simulations that show the same behavior between SM and VM in terms of L(t), m(t), P(τ), P(μ), and the final attractor statistics. The reformulation of the SM in terms of a VM involves a new parameter σ, to bias between anti- and ferromagnetic decisions in the case of frustration. We show that σ plays a crucial role in explaining the phase transition observed in SM. We further explore the role of synchronous versus asynchronous update rules on the intermediate dynamics and the final attractors. As compared to the original SM, we find three additional attractors, two of them related to an asymmetric coexistence between the opposite opinions.

Dynamics of arc-continent collision: the role of crustal-mantle dynamics on controlling the spatio-temporal evolution of stress 

2021 ◽  
Author(s):  
Andres Felipe Rodriguez Corcho ◽  
Sara Morón ◽  
Rebecca Farrington ◽  
Romain Beucher ◽  
Louis Moresi ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Large Scale ◽  
Temporal Evolution ◽  
Density Contrast ◽  
Simultaneous Occurrence ◽  
Return Flow ◽  
Continental Lithosphere ◽  
Mantle Dynamics ◽  
Spatio Temporal

<p>Arc-continent collision is the process by which intra-oceanic arc crust is accreted to continental margins and the most important mechanism that enables the growth of the continental crust since Phanerozoic times. We use numerical visco-plastic mechanical models to explore: (i) the role of lithospheric-mantle dynamics in controlling the spatio-temporal evolution of stress in arc-continent collision settings, and (ii) the role of density contrasts in the evolution of the stress regime. We performed a series of simulations only varying the thickness of the arc based on natural examples as the arc thickness controls the buoyancy of intra-oceanic arcs. Therefore, we investigated a range of density contrasts between the arc and the continental plate. Modelling results show that arc-continent collision can evolve into two contrasting scenarios: (i) slab-anchoring and arc transference in dense arcs where the density contrast between the arc and the adjacent continental lithosphere is above -3% (15-31 km in thickness); and (ii) slab break-off in buoyant arcs where the density contrast between the arc and the adjacent continental lithosphere is below -3% (32-35 km in thickness). We conclude that the large-scale mantle return flow emerged from slab-anchoring facilitates the simultaneous occurrence of compression and extension in the margin by enhancing: (i) compression and lithospheric thickening of the buoyant intra-oceanic arc crust; and (ii) the density contrast between the accreted arc and the continental margin that triggers the release of a gravitational flow. In the particular case of buoyant arcs, the compressional body force applied by the deformed arc to the subducting plate drives its passive retreat. The results of our numerical modelling highlight the importance of the role of lithospheric-mantle dynamics on controlling the spatio-temporal evolution of stress.</p>

The role of the global phase in the spatio-temporal evolution of strong-coupling Brillouin scattering

2018 ◽  
Vol 25 (1) ◽  
pp. 013114 ◽  
Author(s):  
F. Amiranoff ◽  
C. Riconda ◽  
M. Chiaramello ◽  
L. Lancia ◽  
J. R. Marquès ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Temporal Evolution ◽  
Brillouin Scattering ◽  
Spatio Temporal

Epidemiology and molecular diversity of rabies viruses in Bulgaria

2013 ◽  
Vol 142 (4) ◽  
pp. 871-877 ◽  
Author(s):  
E. ROBARDET ◽  
D. ILIEVA ◽  
E. ILIEV ◽  
E. GAGNEV ◽  
E. PICARD-MEYER ◽  
...  
Keyword(s):  
Molecular Diversity ◽  
Temporal Evolution ◽  
Vaccination Campaign ◽  
Emergency Situation ◽  
Disease Spread ◽  
Mountain Range ◽  
Oral Vaccination ◽  
Spatio Temporal ◽  
First Time

SUMMARYA health emergency situation occurred in Bulgaria in 2007 when positive rabies cases were notified in Sofia district in the central-western part of the country, suggesting a southward spread of the disease for the first time in the last 10 years. Phylogenetic analysis on 49 isolates sampled between 2009 and 2011 showed, for the first time, evidence of the existence of NEE and D clustered lineages in Bulgaria. Their geographical distribution clearly reveals the permeability of natural barriers, as already suggested by the disease spread that occurred across the Balkan mountain range in 2007. The monitoring and passive surveillance programmes conducted since the first 2009 oral vaccination campaign, the spatio-temporal evolution of the disease in the country since 2007, and the need for further investigation of the role of jackals in virus dispersion are discussed.

Spatio-temporal evolution and dynamic origin of Jurassic-Cretaceous magmatism in the South China Block

2021 ◽  
Vol 217 ◽  
pp. 103605
Author(s):  
Xianzhi Cao ◽  
Nicolas Flament ◽  
Sanzhong Li ◽  
R. Dietmar Müller
Keyword(s):  
South China ◽  
Temporal Evolution ◽  
South China Block ◽  
The South ◽  
Spatio Temporal ◽  
Cretaceous Magmatism

scholarly journals Spatio-temporal evolution and influencing mechanism of the COVID-19 epidemic in Shandong province, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinlong Shi ◽  
Xing Gao ◽  
Shuyan Xue ◽  
Fengqing Li ◽  
Qifan Nie ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Temporal Evolution ◽  
Geographical Location ◽  
Shandong Province ◽  
Control Measures ◽  
Middle Aged ◽  
Health Crisis ◽  
Aged People ◽  
Spatio Temporal ◽  
And Control

AbstractThe novel coronavirus pneumonia (COVID-19) outbreak that emerged in late 2019 has posed a severe threat to human health and social and economic development, and thus has become a major public health crisis affecting the world. The spread of COVID-19 in population and regions is a typical geographical process, which is worth discussing from the geographical perspective. This paper focuses on Shandong province, which has a high incidence, though the first Chinese confirmed case was reported from Hubei province. Based on the data of reported confirmed cases and the detailed information of cases collected manually, we used text analysis, mathematical statistics and spatial analysis to reveal the demographic characteristics of confirmed cases and the spatio-temporal evolution process of the epidemic, and to explore the comprehensive mechanism of epidemic evolution and prevention and control. The results show that: (1) the incidence rate of COVID-19 in Shandong is 0.76/100,000. The majority of confirmed cases are old and middle-aged people who are infected by the intra-province diffusion, followed by young and middle-aged people who are infected outside the province. (2) Up to February 5, the number of daily confirmed cases shows a trend of “rapid increase before slowing down”, among which, the changes of age and gender are closely related to population migration, epidemic characteristics and intervention measures. (3) Affected by the regional economy and population, the spatial distribution of the confirmed cases is obviously unbalanced, with the cluster pattern of “high–low” and “low–high”. (4) The evolution of the migration pattern, affected by the geographical location of Wuhan and Chinese traditional culture, is dominated by “cross-provincial” and “intra-provincial” direct flow, and generally shows the trend of “southwest → northeast”. Finally, combined with the targeted countermeasures of “source-flow-sink”, the comprehensive mechanism of COVID-19 epidemic evolution and prevention and control in Shandong is revealed. External and internal prevention and control measures are also figured out.

scholarly journals The Role of Technology in Greenhouse Agriculture: Towards a Sustainable Intensification in Campo de Dalías (Almería, Spain)

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 101
Author(s):  
Antonio J. Mendoza-Fernández ◽  
Araceli Peña-Fernández ◽  
Luis Molina ◽  
Pedro A. Aguilera
Keyword(s):  
Land Use ◽  
Economic Development ◽  
Water Resources ◽  
Natural Resources ◽  
Temporal Evolution ◽  
Technological Development ◽  
Sustainable Intensification ◽  
Short Period ◽  
Cultivation Techniques

Campo de Dalías, located in southeastern Spain, is the greatest European exponent of greenhouse agriculture. The development of this type of agriculture has led to an exponential economic development of one of the poorest areas of Spain, in a short period of time. Simultaneously, it has brought about a serious alteration of natural resources. This article will study the temporal evolution of changes in land use, and the exploitation of groundwater. Likewise, this study will delve into the technological development in greenhouses (irrigation techniques, new water resources, greenhouse structures or improvement in cultivation techniques) seeking a sustainable intensification of agriculture under plastic. This sustainable intensification also implies the conservation of existing natural areas.

scholarly journals Adjoint-based direct data assimilation of GNSS time series for optimizing frictional parameters and predicting postseismic deformation following the 2003 Tokachi-oki earthquake

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Masayuki Kano ◽  
Shin’ichi Miyazaki ◽  
Yoichi Ishikawa ◽  
Kazuro Hirahara
Keyword(s):  
Time Series ◽  
Data Assimilation ◽  
Evaluation Method ◽  
Temporal Evolution ◽  
Recovery Process ◽  
Postseismic Deformation ◽  
Coseismic Slip ◽  
Megathrust Earthquakes ◽  
Spatio Temporal ◽  
Gnss Time Series

Abstract Postseismic Global Navigation Satellite System (GNSS) time series followed by megathrust earthquakes can be interpreted as a result of afterslip on the plate interface, especially in its early phase. Afterslip is a stress release process accumulated by adjacent coseismic slip and can be considered a recovery process for future events during earthquake cycles. Spatio-temporal evolution of afterslip often triggers subsequent earthquakes through stress perturbation. Therefore, it is important to quantitatively capture the spatio-temporal evolution of afterslip and related postseismic crustal deformation and to predict their future evolution with a physics-based simulation. We developed an adjoint data assimilation method, which directly assimilates GNSS time series into a physics-based model to optimize the frictional parameters that control the slip behavior on the fault. The developed method was validated with synthetic data. Through the optimization of frictional parameters, the spatial distributions of afterslip could roughly (but not in detail) be reproduced if the observation noise was included. The optimization of frictional parameters reproduced not only the postseismic displacements used for the assimilation, but also improved the prediction skill of the following time series. Then, we applied the developed method to the observed GNSS time series for the first 15 days following the 2003 Tokachi-oki earthquake. The frictional parameters in the afterslip regions were optimized to A–B ~ O(10 kPa), A ~ O(100 kPa), and L ~ O(10 mm). A large afterslip is inferred on the shallower side of the coseismic slip area. The optimized frictional parameters quantitatively predicted the postseismic GNSS time series for the following 15 days. These characteristics can also be detected if the simulation variables can be simultaneously optimized. The developed data assimilation method, which can be directly applied to GNSS time series following megathrust earthquakes, is an effective quantitative evaluation method for assessing risks of subsequent earthquakes and for monitoring the recovery process of megathrust earthquakes.

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