Aerosols in the Pre-industrial Atmosphere

Purpose of Review: We assess the current understanding of the state and behaviour of aerosols under pre-industrial conditions and the importance for climate. Recent Findings: Studies show that the magnitude of anthropogenic aerosol radiative forcing over the industrial period calculated by climate models is strongly affected by the abundance and properties of aerosols in the pre-industrial atmosphere. The low concentration of aerosol particles under relatively pristine conditions means that global mean cloud albedo may have been twice as sensitive to changes in natural aerosol emissions under pre-industrial conditions compared to present-day conditions. Consequently, the discovery of new aerosol formation processes and revisions to aerosol emissions have large effects on simulated historical aerosol radiative forcing. Summary: We review what is known about the microphysical, chemical, and radiative properties of aerosols in the pre-industrial atmosphere and the processes that control them. Aerosol properties were controlled by a combination of natural emissions, modification of the natural emissions by human activities such as land-use change, and anthropogenic emissions from biofuel combustion and early industrial processes. Although aerosol concentrations were lower in the pre-industrial atmosphere than today, model simulations show that relatively high aerosol concentrations could have been maintained over continental regions due to biogenically controlled new particle formation and wildfires. Despite the importance of pre-industrial aerosols for historical climate change, the relevant processes and emissions are given relatively little consideration in climate models, and there have been very few attempts to evaluate them. Consequently, we have very low confidence in the ability of models to simulate the aerosol conditions that form the baseline for historical climate simulations. Nevertheless, it is clear that the 1850s should be regarded as an early industrial reference period, and the aerosol forcing calculated from this period is smaller than the forcing since 1750. Improvements in historical reconstructions of natural and early anthropogenic emissions, exploitation of new Earth system models, and a deeper understanding and evaluation of the controlling processes are key aspects to reducing uncertainties in future

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Not AvailableThe study was to develop Vibrio harveyi biofilm-based novel microbial product and its oral delivery for high health Penaeus vannamei farming. Yield of bacterial biofilm was optimized on chitin substrate (size: <360, 360–850 and 850–1250 μm; concentration: 0.3, 0.6 and 0.9%) in tryptone soy broth (0.15%). The biofilm was characterized by crystal violet assay, SEM and LSCM imaging; protein profiling by SDS-PAGE and LC-ESI-MS/MS. The immune stimulatory effect of the biofilm in yard experiments was evaluated by relative quantification of immune genes using real-time PCR effect on overall improvement on health status under field trials. The highest biofilm yield (6.13 ± 0.2 × 107 cfu/ml) was obtained at 0.6% of <360 μm chitin substrate. The biofilm formation was stabilized by 96 h of incubation at 30 °C. Protein profiling confirmed expression of six additional proteins (SDS-PAGE) and 11 proteins were differentially expressed (LC-ESI-MS/MS) in biofilm cells over free cells of V. harveyi. Oral administration of the biofilm for 48 h confirmed to enhance expression of antimicrobial peptides, penaeidin, crustin and lysozyme in P. vannamei. Further Oral administration of biofilm for two weeks to P. vannamei (1.8 ± 0.13 g) improved the growth (2.66 ± 0.06 g) and survival (84.44 ± 1.82%) compared to control (2.15 ± 0.03 g; 70.94 ± 0.66%) Nursery trials showed a significant reduction in occurrence of anatomical deformities like antenna cut (12.67 ± 0.66%), rostrum cut (4.66 ± 0.87%), and tail rot (3.33 ± 0.88%), compared to animals fed with normal diet which was 24.33 ± 2.72; 14 ± 1.52 and 10.66 ± 1.45% respectively. In vitro and in vivo studies suggest inactivated biofilm cells of V. harveyi on chitin substrate express additional antigenic proteins and when administered orally through feed at regular intervals stimulates immune response and improve growth, survival and health status of shrimp.Not Availabl