The role of hydrostatic pressure on developmental stages of Pomatoceros lamarcki (Polychaeta: Serpulidae) exposed to water accommodated fractions of crude oil and positive genotoxins at simulated depths of 1000–3000 m

AbstractDespite the central role of hemocytes in crustacean immunity, the process of hemocyte differentiation and maturation remains unclear. In some decapods, it has been proposed that the two main types of hemocytes, granular cells (GCs) and semigranular cells (SGCs), differentiate along separate lineages. However, our current findings challenge this model. By tracking newly produced hemocytes and transplanted cells, we demonstrate that almost all the circulating hemocytes of crayfish belong to the GC lineage. SGCs and GCs may represent hemocytes of different developmental stages rather than two types of fully differentiated cells. Hemocyte precursors produced by progenitor cells differentiate in the hematopoietic tissue (HPT) for 3 ~ 4 days. Immature hemocytes are released from HPT in the form of SGCs and take 1 ~ 3 months to mature in the circulation. GCs represent the terminal stage of development. They can survive for as long as 2 months. The changes in the expression pattern of marker genes during GC differentiation support our conclusions. Further analysis of hemocyte phagocytosis indicates the existence of functionally different subpopulations. These findings may reshape our understanding of crustacean hematopoiesis and may lead to reconsideration of the roles and relationship of circulating hemocytes.

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The role of shearing effect in evolution of the microscopic behavior of wax crystals

New Journal of Chemistry ◽

10.1039/d1nj01407b ◽

2021 ◽

Author(s):

Yuanhao Li ◽

Jian Zhao ◽

Hang Dong ◽

Xiangrui Xi

Keyword(s):

Crude Oil ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Dynamical Behaviors ◽

Physical Phenomena ◽

Wax Crystals

The microstructure and dynamical behaviors of wax crystals in waxy crude oil are the fundamental reasons for a series of physical phenomena in the process of transportation. In order to...

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The role of coronavirus news in the volatility forecasting of crude oil futures markets: Evidence from China

Resources Policy ◽

10.1016/j.resourpol.2021.102173 ◽

2021 ◽

Vol 73 ◽

pp. 102173

Author(s):

Zibo Niu ◽

Yuanyuan Liu ◽

Wang Gao ◽

Hongwei Zhang

Keyword(s):

Crude Oil ◽

Futures Markets ◽

Volatility Forecasting ◽

Oil Futures ◽

Crude Oil Futures

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Forecasting the Volatility of Crude Oil: The Role of Uncertainty and Spillovers

Energies ◽

10.3390/en14144173 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4173

Author(s):

Rangan Gupta ◽

Christian Pierdzioch

Keyword(s):

Crude Oil ◽

Predictive Value ◽

Realized Variance ◽

International Spillovers ◽

Forecasting Models ◽

West Texas ◽

Out Of Sample ◽

One Year ◽

Lasso Estimator

We use a dataset for the group of G7 countries and China to study the out-of-sample predictive value of uncertainty and its international spillovers for the realized variance of crude oil (West Texas Intermediate and Brent) over the sample period from 1996Q1 to 2020Q4. Using the Lasso estimator, we found evidence that uncertainty and international spillovers had predictive value for the realized variance at intermediate (two quarters) and long (one year) forecasting horizons in several of the forecasting models that we studied. This result holds also for upside (good) and downside (bad) variance, and irrespective of whether we used a recursive or a rolling estimation window. Our results have important implications for investors and policymakers.

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Epigenetic transgenerational inheritance, Gametogenesis and Germline Development

Biology of Reproduction ◽

10.1093/biolre/ioab085 ◽

2021 ◽

Author(s):

Millissia Ben Maamar ◽

Eric E Nilsson ◽

Michael K Skinner

Keyword(s):

Developmental Biology ◽

Environmental Factors ◽

Biological System ◽

Developmental Stages ◽

Primordial Germ Cell ◽

Cell Types ◽

Transgenerational Inheritance ◽

Germline Development ◽

Current Review

Abstract One of the most important developing cell types in any biological system is the gamete (sperm and egg). The transmission of phenotypes and optimally adapted physiology to subsequent generations is in large part controlled by gametogenesis. In contrast to genetics, the environment actively regulates epigenetics to impact the physiology and phenotype of cellular and biological systems. The integration of epigenetics and genetics is critical for all developmental biology systems at the cellular and organism level. The current review is focused on the role of epigenetics during gametogenesis for both the spermatogenesis system in the male and oogenesis system in the female. The developmental stages from the initial primordial germ cell through gametogenesis to the mature sperm and egg are presented. How environmental factors can influence the epigenetics of gametogenesis to impact the epigenetic transgenerational inheritance of phenotypic and physiological change in subsequent generations is reviewed.

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Role of Shearing Dispersion and Stripping in Wax Deposition in Crude Oil Pipelines

Energies ◽

10.3390/en12224325 ◽

2019 ◽

Vol 12 (22) ◽

pp. 4325

Author(s):

Zhihua Wang ◽

Yunfei Xu ◽

Yi Zhao ◽

Zhimin Li ◽

Yang Liu ◽

...

Keyword(s):

Crude Oil ◽

Flow Rate ◽

Critical Flow ◽

Wax Deposition ◽

Dominant Effect ◽

Critical Flow Rate ◽

Oil Pipelines ◽

Oil Flow ◽

Shearing Mechanism

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.

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