Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic

In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from −0.15–0.26 to 0.17–0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for April–September 2008 were 2.18–3.70 μg m−3 and 0.85–1.68 μg m−3 over the Arctic, respectively. These corresponded to an increase of 140–180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations

Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic

In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from −0.15–0.26 to 0.17–0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for April–September 2008 were 2.18–3.70 μg m−3 and 0.85–1.68 μg m−3 over the Arctic, respectively. These corresponded to an increase of 140–180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations

VEGF-A regulated by progesterone governs uterine angiogenesis and vascular remodelling during pregnancy

Peer reviewe

Cloudiness Parameterization for Use in Atmospheric Models: A Review and New Perspectives

In atmospheric models, the representation of cloudiness is a direct linkage between the moisture amount and associated radiative forcing. This paper begins by providing a review of the parameterization of cloudiness that has been used for numerical weather predictions and climate studies. The inherent uncertainties in representing a partial fraction of clouds for radiation feedback and in evaluating it against the corresponding observations are focused. It is also stated that the major hydrometeor categories of water substances such as cloud ice and water that are responsible for cloud cover are readily available in modern weather and climate models. Inconsistencies in cloud cover and hydrometeors, even in the case of the prognostic method, are discussed. The compensating effect of cloudiness for radiative feedback is found to imply that the condensed water amount itself is more influential on the radiative forcing, rather than the accuracy of the cloudiness. Based on the above perspectives, an alternative diagnostic parameterization method is proposed, utilizing a monotonic relation between the cloud water amounts and cloudiness that are obtained from aircraft and satellite observations. The basic premise of this approach lies in the accuracy of the water substance in the models, indicating that future efforts need to be given to improvements in physical processes concerning hydrometeor properties for the accurate representation of cloud radiative feedback

Fermentative biohydrogen production by a new chemoheterotrophic bacterium Citrobacter sp Y19

A newly isolated Citrobacter sp. Y19 for CO-dependent H-2 production was studied for its capability of fermentative H-2 production in batch cultivation. When glucose was used as carbon source, the PH of the culture medium significantly decreased as fermentation proceeded and H2 production was seriously inhibited. The use of fortified phosphate at 60-180 mM alleviated this inhibition. By increasing culture temperatures (25-36degreesC), faster cell growth and higher initial H2 production rates were observed but final H2 production and yield were almost constant irrespective of temperature. Optimal specific H2 production activity was observed at 36degreesC and pH 6-7. The increase of glucose concentration (1-20 g/1) in the culture medium resulted in higher H2 production, but the yield of H2 production (mol H-2/mol glucose) gradually decreased with increasing glucose concentration. Carbon mass balance showed that, in addition to cell mass, ethanol, acetate and CO2 were the major fermentation products and comprised more than 70% of the carbon consumed. The maximal H2 yield and H2 production rate were estimated to be 2.49 mol H-2/mol glucose and 32.3 mmol H-2/g cell h, respectively. The overall performance of Y19 in fermentative H-2 production is quite similar to that of most H-2-producing bacteria previously studied, especially to that of Rhodopseudomonas palustris P4, and this indicates that the attempt to find an outstanding bacterial strain for fermentative H2 production might be very difficult if not impossible. (C) 2003 International Association for Hydrogen Energy

Aerosol Indirect Effects on the Predicted Precipitation in a Global Weather Forecasting Model

Aerosol indirect effects on precipitation were investigated in this study using a Global/Regional Integrated Model system (GRIMs) linked with a chemistry package devised for reducing the heavy computational burden occurring in common atmosphere–chemistry coupling models. The chemistry package was based on the Goddard Chemistry Aerosol Radiation and Transport scheme of Weather Research and Forecasting with Chemistry (WRF-Chem), and five tracers that are relatively important for cloud condensation nuclei (CCN) formation were treated as prognostic variables. For coupling with the cloud physics processes in the GRIMs, the CCN number concentrations derived from the simplified chemistry package were utilized in the cumulus parameterization scheme (CPS) and the microphysics scheme (MPS). The simulated CCN number concentrations were higher than those used in original cloud physics schemes and, overall, the amount of incoming shortwave radiation reaching the ground was indirectly reduced by an increase in clouds owing to a high CCN. The amount of heavier precipitation increased over the tropics owing to the inclusion of enhanced riming effects under deep precipitating convection. The trend regarding the changes in non-convective precipitation was mixed depending on the atmospheric conditions. The increase in small-size cloud water owing to a suppressed autoconversion led to a reduction in precipitation. More precipitation can occur when ice particles fall under high CCN conditions owing to the accretion of cloud water by snow and graupel, along with their melting

Transcriptomics analysis of Escherichia coli W mutant tolerant to high concentration of 3-hydroxypropionic acid

3-Hydroxypropionic acid (3-HP) is an important platform chemical which can be produced from glycerol by recombinant Escherichia coli. One of the challenges for commercialization of 3-HP production is its toxic effect at high concentration. Recently, a novel transcriptional regulator (designated as 3HPT) was found to be related with 3-HP tolerance in E. coli. However, the mechanism of its regulation is still unknown. To address this issue, transcriptome analysis of several E. coli W mutants which is highly tolerant to 3-HP was conducted. Interestingly, there was more than hundreds of genes are regulated by 3HPT. Among them, many genes are related with acid tolerance mechanisms, some genes have not been well studied. Functional analysis and further experiments to elucidate the mechanism are in progress