accumulation process
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2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Paul Palmqvist ◽  
M. Patrocinio Espigares ◽  
Juan A. Pérez-Claros ◽  
Borja Figueirido ◽  
Antonio Guerra-Merchán ◽  
...  

AbstractVenta Micena, an Early Pleistocene site of the Baza Basin (SE Spain), preserves a rich and diverse assemblage of large mammals. VM3, the main excavation quarry of the site, has been interpreted as a den of the giant hyaena Pachycrocuta brevirostris in the plain that surrounded the Baza palaeolake. Taphonomic analysis of VM3 has shown that the hyaenas scavenged the prey previously hunted by the hypercarnivores, transported their remains to the communal den, and consumed the skeletal parts according to their marrow contents and mineral density. In a recent paper (Luzón et al. in Sci Rep 11:13977, 10.1038/s41598-021-93261-1, 2021), a small sample of remains unearthed from VM4, an excavation quarry ~ 350 m distant from VM3, is analysed. The authors indicate several differences in the taphonomic features of this assemblage with VM3, and even suggest that a different carnivore could have been the agent involved in the bone accumulation process. Here, we make a comparative analysis of both quarries and analyse more skeletal remains from VM4. Our results indicate that the assemblages are broadly similar in composition, except for slight differences in the frequency of megaherbivores, carnivores and equids according to NISP values (but not to MNI counts), the degree of bone weathering, and the intensity of bone processing by the hyaenas. Given that VM4 and VM3 were not coeval denning areas of P. brevirostris, these differences suggest that during the years when the skeletal remains were accumulated by the hyaenas at VM3, the rise of the water table of the Baza palaeolake that capped with limestone the bones was delayed compared to VM4, which resulted in their more in-depth consumption by the hyaenas.


2021 ◽  
Author(s):  
Shengyu Shi ◽  
Jiale Chen ◽  
Clarisse Bourdelle ◽  
Xiang Jian ◽  
Tomas Odstrcil ◽  
...  

Abstract The behavior of heavy/high-Z impurity tungsten (W) in the core of hybrid (high normalized beta β_N plasmas) scenario on EAST with ITER-like divertor (ILD) is analyzed. W accumulation is often observed and seriously degrades the plasma performance (Xiang Gao et al 2017 Nucl. Fusion 57 056021). The dynamics of the W accumulation process of a hybrid discharge are examined considering the concurrent evolution of the background plasma parameters. It turns out that the toroidal rotation and density peaking of the bulk plasma are usually large in the central region, which is particularly prone to the W accumulation. A time slice during the W accumulation phase is modeled, accounting for both neoclassical and turbulent transport components of W, through NEO with poloidal asymmetry effects induced by toroidal rotation, and TGLF, respectively. This modeling reproduces the experimental observations of W accumulation and identifies the neoclassical inward convection/pinch velocity of W due to the large density peaking of the bulk plasma and toroidal rotation in the central region as one of the main reasons for the W accumulation. In addition, the NEO+TGLF+STRAHL modeling can not only predict the core W density profile but also closely reconstruct the radiated information mainly produced by W in the experiment.


2021 ◽  
pp. 0094582X2110608
Author(s):  
Leda Maria Paulani

The liberalization of markets for goods and assets that took place beginning in the 1980s, alongside a strengthening of the resulting transnationalization of capital, did not alter the basic hierarchical organization of the global capitalist system. This new dependency, here called “dependency 4.0,” is based on the rent seeking that marks the contemporary wealth accumulation process and ongoing technological progress. Brazil’s incorporation into the international division of labor is emblematic of this type of subordination. A liberalização dos mercados de bens e ativos que teve lugar a partir dos anos 1980 e o fortalecimento da transnacionalização do capital que resultou daí não alteraram o pressuposto fundamental da prevalência de uma organização hierárquica no sistema capitalista mundial. Um novo tipo de dependência a relacionar países centrais e periféricos, dependência 4.0, estaria assentada no rentismo que marca hoje o processo de acumulação e na natureza do progresso tecnológico em curso. O caso do Brasil—a história de sua inserção na divisão internacional do trabalho—é emblemática desse novo tipo de subordinação.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lin Jiang ◽  
Wen Zhao ◽  
Jianguo Huang ◽  
Yang Fan ◽  
Jiaqing Hao

AbstractThe study of natural gas accumulation process in tight formation has become the focus of the petroleum industry. One of the priorities is the effects of interactions in natural gas/water/rock system on hydrocarbon migration and accumulation process. On the macroscopic scale, we investigate the interactions in natural gas/water/rock system by formation fluorescence test and production data analysis. One the microscopic scale, the mechanisms are revealed by mathematical analysis and experimental methods considering the variation of geological temperature and pressure. The effects of interactions in natural gas/water/rock system are also simulated by numerical simulation. The results are visualized and quantified. A novel semi-analytical method based on a physical experiment is proposed to calculate the temperature- and pressure-dependent contact angle and interface tension which reflect the interactions in the natural gas–water–rock system. This semi-analytical is embedded in the numerical simulation during the simulation of the natural gas charging process. The results indicate that with the increase of geological temperature and pressure, the contact angle will increase and the interface tension between natural gas and water will decrease. The capillary resistance in the formation will be reduced. Since the decrease of capillary resistance, the natural gas can be charged into smaller pores, so that the actual charging threshold is lower than the one originally obtained under present reservoir conditions. After considering the temperature and pressure during the accumulation process, some sand bodies that were thought not to be charged may have natural gas accumulate.


2021 ◽  
Author(s):  
Paul Palmqvist ◽  
M. Patrocinio Espigares ◽  
Juan A. Pérez-Claros ◽  
Borja Figueirido ◽  
Antonio Guerra-Merchán ◽  
...  

Abstract Venta Micena, an Early Pleistocene site of the Baza Basin (SE Spain), preserves a rich and diverse assemblage of large mammals. VM3, the main excavation quarry of the site, has been interpreted as a den of the giant hyaena Pachycrocuta brevirostris in the plain that surrounded the Baza palaeolake. Taphonomic analysis of VM3 has shown that the hyaenas scavenged the prey previously hunted by the hypercarnivores, transported their remains to the communal den, and consumed the skeletal parts according to their marrow contents and mineral density. In a recent paper, a small sample of remains unearthed from VM4, an excavation quarry ~350 m distant from VM3, are analysed. The authors indicate several differences in the taphonomic features of this assemblage with VM3, and even suggest that a different carnivore could have been the agent involved in the bone accumulation process. Here we make a comparative analysis of both quarries and analyse more skeletal remains from VM4. Our results indicate that the assemblages are broadly similar in composition, except for slight differences in the frequency of megaherbivores, carnivores and equids according to NISP values (but not to MNI counts), the degree of bone weathering, and the intensity of bone processing by the hyaenas. Given that VM4 and VM3 were not coeval denning areas of P. brevirostris, these differences suggest that during the years when the skeletal remains were accumulated by the hyaenas at VM3, the rise of the water table of the Baza palaeolake that capped with limestone the bones was delayed compared to VM4, which resulted in their more in-depth consumption by the hyaenas.


2021 ◽  
Author(s):  
Paul Palmqvist ◽  
M. Patrocinio Espigares ◽  
Juan A. Pérez-Claros ◽  
Borja Figueirido ◽  
Antonio Guerra-Merchán ◽  
...  

Abstract Venta Micena, an Early Pleistocene site of the Baza Basin (SE Spain), preserves a rich and diverse assemblage of large mammals. VM3, the main excavation quarry of the site, has been interpreted as a den of the giant hyaena Pachycrocuta brevirostris in the plain that surrounded the Baza palaeolake. Taphonomic analysis of VM3 has shown that the hyaenas scavenged the prey previously hunted by the hypercarnivores, transported their remains to the communal den, and consumed the skeletal parts according to their marrow contents and mineral density. In a recent paper, a small sample of remains unearthed from VM4, an excavation quarry ~350 m distant from VM3, are analysed. The authors indicate several differences in the taphonomic features of this assemblage with VM3, and even suggest that a different carnivore could have been the agent involved in the bone accumulation process. Here we make a comparative analysis of both quarries and analyse more skeletal remains from VM4. Our results indicate that the assemblages are broadly similar in composition, except for slight differences in the frequency of megaherbivores, carnivores and equids according to NISP values (but not to MNI counts), the degree of bone weathering, and the intensity of bone processing by the hyaenas. Given that VM4 and VM3 were not coeval denning areas of P. brevirostris, these differences suggest that during the years when the skeletal remains were accumulated by the hyaenas at VM3, the rise of the water table of the Baza palaeolake that capped with limestone the bones was delayed compared to VM4, which resulted in their more in-depth consumption by the hyaenas.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Wang ◽  
Yu-ping Liang ◽  
Jin-dong Zhu ◽  
Yu-xi Wang ◽  
Meng-ya Yang ◽  
...  

Phototropins, namely, phototropin 1 (phot1) and phototropin 2 (phot2), mediate chloroplast movement to maximize photosynthetic efficiency and prevent photodamage in plants. Phot1 primarily functions in chloroplast accumulation process, whereas phot2 mediates both chloroplast avoidance and accumulation responses. The avoidance response of phot2-mediated chloroplasts under high-intensity blue light (HBL) limited the understanding of the function of phot1 in the chloroplast accumulation process at the HBL condition. In this study, we showed that the phot2 mutant exhibits a chloroplast accumulation response under HBL, which is defective when the root phototropism 2 (RPT2) gene is mutated in the phot2 background, mimicking the phenotype of the phot1 phot2 double mutant. A further analysis revealed that the expression of RPT2 was induced by HBL and the overexpression of RPT2 could partially enhance the chloroplast accumulation response under HBL. These results confirmed that RPT2 also participates in regulating the phot1-mediated chloroplast accumulation response under HBL. In contrast, RPT2 functions redundantly with neural retina leucine zipper (NRL) protein for chloroplast movement 1 (NCH1) under low-light irradiation. In addition, no chloroplast accumulation response was detected in the phot2 jac1 double mutant under HBL, which has been previously observed in phot2 rpt2 and phot1 phot2 double mutants. Taken together, our results indicated that phot1 mediates the HBL-induced chloroplast accumulation response in an RPT2-dependent manner and is also regulated by j-domain protein required for chloroplast accumulation response 1 (JAC1).


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