A microscale model for combined CO2 diffusion and photosynthesis in leaves

Transport of CO2 in leaves was investigated by combining a 2-D, microscale CO2 transport model with photosynthesis kinetics in wheat (Triticum aestivum L.) leaves. The biophysical microscale model for gas exchange featured an accurate geometric representation of the actual 2-D leaf tissue microstructure and accounted for diffusive mass exchange of CO2. The resulting gas transport equations were coupled to the biochemical Farquhar-von Caemmerer-Berry model for photosynthesis. The combined model was evaluated using gas exchange and chlorophyll fluorescence measurements on wheat leaves. In general a good agreement between model predictions and measurements was obtained, but a discrepancy was observed for the mesophyll conductance at high CO2 levels and low irradiance levels. This may indicate that some physiological processes related to photosynthesis are not incorporated in the model. The model provided detailed insight into the mechanisms of gas exchange and the effects of changes in ambient CO2 concentration or photon flux density on stomatal and mesophyll conductance. It represents an important step forward to study CO2 diffusion coupled to photosynthesis at the leaf tissue level, taking into account the leaf's actual microstructure

A 3-D microscale model for Co2 GasTransport in tomato leaves during photosynthesis

Exchange of CO2 in tomato (Solanum lycopersicum L.) leaves was modelled using combined gas diffusion and photosynthesis kinetics in a real 3-D geometric representation of the cellular microstructure, obtained by synchrotron radiation X-ray microtomography. The microscale model for gas exchange accounted for diffusive mass transport of CO2 in the intercellular space (pores), the cell wall network and the intracellular liquid of cells. The photosynthesis kinetics described by the extended Farquhar, von Caemmerer & Berry model were coupled to the gas exchange inside the mesophyll cells. The coupled model was validated by means of gas exchange and chlorophyll fluorescence measurements. The model provides detailed insight into the mechanisms of gas exchange and insight into the effects of changes in ambient CO2 concentration or photon flux density on stomatal and mesophyll conductance. The resistance to diffusion of CO2 from the intercellular air spaces within the leaf through the mesophyll to the sites of carboxylation during photosynthesis depended on the 3-D microstructure of leaf tissue. The model represents an important step forward to study CO2 diffusion coupled to photosynthesis at the leaf tissue level, taking into account its actual 3-D microstructure

The Cancer Genome Atlas Comprehensive Molecular Characterization of Renal Cell Carcinoma

Renal cell carcinoma(RCC) is not a single disease, but several histologically defined cancers with different genetic drivers, clinical courses, and therapeutic responses. The current study evaluated 843 RCC from the three major histologic subtypes, including 488 clear cell RCC, 274 papillary RCC, and 81 chromophobe RCC. Comprehensive genomic and phenotypic analysis of the RCC subtypes reveals distinctive features of each subtype that provide the foundation for the development of subtype-specific therapeutic and management strategies for patients affected with these cancers. Somatic alteration of BAP1, PBRM1, and PTEN and altered metabolic pathways correlated with subtype-specific decreased survival, while CDKN2A alteration, increased DNA hypermethylation, and increases in the immune-related Th2 gene expression signature correlated with decreased survival within all major histologic subtypes. CIMP-RCC demonstrated an increased immune signature, and a uniform and distinct metabolic expression pattern identified a subset of metabolically divergent (MD) ChRCC that associated with extremely poor survival

Impact of COVID-19 on Economic Well-Being and Quality of Life of the Vietnamese During the National Social Distancing

10.3389/fpsyg.2020.565153Frontiers in Psychology1156515

Interactive visualization of large-scale architectural models over the grid: Strolling in Tang Chang'an city

Computer Aided Architectural Design Futures 2005 - Proceedings of the 11th International CAAD Futures Conference93-10

Demand for health information on COVID-19 among Vietnamese

10.3390/ijerph17124377International Journal of Environmental Research and Public Health171212-Ja