Exploring the potential of using remote sensing data to model agricultural systems in data-limited areas

Crop models (CMs) can be a key component in addressing issues of global food security as they can be used to monitor and improve crop production. Regardless of their wide utilization, the employment of these models, particularly in isolated and rural areas, is often limited by the lack of reliable input data. This data scarcity increases uncertainties in model outputs. Nevertheless, some of these uncertainties can be mitigated by integrating remotely sensed data into the CMs. As such, increasing efforts are being made globally to integrate remotely sensed data into CMs to improve their overall performance and use. However, very few such studies have been done in South Africa. Therefore, this research assesses how well a crop model assimilated with remotely sensed data compares with a model calibrated with actual ground data (Maize_control). Ultimately leading to improved local cropping systems knowledge and the capacity to use CMs. As such, the study calibrated the DSSAT-CERES-Maize model using two generic soils (i.e. heavy clay soil and medium sandy soil) which were selected based on literature, to measure soil moisture from 1985 to 2015 in Bloemfontein. Using the data assimilation approach, the model's soil parameters were then adjusted based on remotely sensed soil moisture (SM) observations. The observed improvement was mainly assessed through the lens of SM simulations from the original generic set up to the final remotely sensed informed soil profile set up. The study also gave some measure of comparison with Maize_control and finally explored the impacts of this specific SM improvement on evapotranspiration (ET) and maize yield. The result shows that when compared to the observed data, assimilating remotely sensed data with the model significantly improved the mean simulation of SM while maintaining the representation of its variability. The improved SM, as a result of assimilation of remotely sensed data, closely compares with the Maize_control in terms of mean but there was no improvement in terms of variability. Data assimilation also improved the mean and variability of ET simulation when compared that of Maize_control, but only with heavy clay soil. However, maize yield was not improved in comparison. This confirms that these outputs were influenced by other factors aside from SM or the soil profile parameters. It was concluded that remote sensing data can be used to bias correct model inputs, thus improve certain model outputs

Remote Sensing of Land Surface Phenology

Land surface phenology (LSP) uses remote sensing to monitor seasonal dynamics in vegetated land surfaces and retrieve phenological metrics (transition dates, rate of change, annual integrals, etc.). LSP has developed rapidly in the last few decades. Both regional and global LSP products have been routinely generated and play prominent roles in modeling crop yield, ecological surveillance, identifying invasive species, modeling the terrestrial biosphere, and assessing impacts on urban and natural ecosystems. Recent advances in field and spaceborne sensor technologies, as well as data fusion techniques, have enabled novel LSP retrieval algorithms that refine retrievals at even higher spatiotemporal resolutions, providing new insights into ecosystem dynamics. Meanwhile, rigorous assessment of the uncertainties in LSP retrievals is ongoing, and efforts to reduce these uncertainties represent an active research area. Open source software and hardware are in development, and have greatly facilitated the use of LSP metrics by scientists outside the remote sensing community. This reprint covers the latest developments in sensor technologies, LSP retrieval algorithms and validation strategies, and the use of LSP products in a variety of fields. It aims to summarize the ongoing diverse LSP developments and boost discussions on future research prospects

Isolation and characterisation of imipenem-resistant bacteria from natural environments and clinical settings

The development and spread of bacterial resistance to antimicrobials is now recognised as a key threat to public health and society. A small number of antimicrobials, including imipenem and vancomycin, are now considered to be the drugs of ‘last resort’ for treating antibiotic resistant bacteria. This study investigates and characterises antibiotic (imipenem) resistant bacteria in environmental and clinical samples from the U.K. Imipenem resistant (ImR) bacteria were isolated and characterised from river water samples from East Yorkshire and soil samples from Lincolnshire. ImR clinical isolates from different hospitals (York, Sheffield and Hull) were also characterised. Phenotypic resistance to imipenem was observed in 11.2% (75/670 CFU ml⁻¹), 13.3% (145.35 x 10⁵/ 109.1 x 10⁶ CFU g⁻¹) and 38.5% (42/109) of water, soil and clinical bacterial isolates, respectively.The minimum inhibitory concentrations (MICs) of the clinical isolates were generally higher (> 32 mg L⁻¹ in 71.4% of isolates) than those of the environmental isolates, which were around 4 mg L⁻¹ in 63.4% of water isolates and in 42.7% of soil isolates. β-lactamase activity studies showed that the most common β-lactamases among the environmental isolates were class B metallo β-lactamases (MBLs) (84.2%), while class A Klebsiella pneumoniae carbapenemases (KPCs) (40.5%) were the most common β-lactamases observed in the clinical isolates. Higher frequencies of multi-drug resistant (MDR) patterns were detected among the environmental isolates than among the clinical strains. Sequencing of 16S rRNA genes identified 30 (17 species), 96 (27 species), and 42 (11 species) ImR bacteria in water, soil and clinical samples, respectively. The most abundant genera identified were Caulobacter (36.7%), Stenotrophomonas (44.8%) and Stenotrophomonas (40.5%) from water, soil and clinical environments, respectively. PCR products were generated from ImR clinical isolates and some of the environmental isolates using primers targeting β-lactamase genes. Sequence analysis of these products from clinical isolates showed that they were specific and related to β-lactamase genes. However, the products from environmental isolates were not related to known genes characterised from antibiotic resistant clinically important bacteria. This suggests that there is a potentially large and divergent gene pool encoding for imipenem ressitance within natural environments, and that river water and agricultural soil are important as reservoirs of novel antibiotic resistance. Genome sequencing was used to characterise 8 MDR Stenotrophomonas spp. isolates from water, soil and clinical samples. This analysis showed the detection of β-lactamases genes (between 8 and 15 genes per isolate) including class A (L2), B (L1) and C (AmpC), fluoroquinolones resistance genes (between 4-8 genes per isolate), and genes encoding MDR efflux pumps (between 23-32 genes per isolate). Antibiotic resistance genes for other antimicrobials were also observed in small numbers; these represented aminoglycoside, sulphonamide and tetracycline resistance. Genes encoding resistance to heavy metal resistance (between 13-27 genes per isolate) were also observed. Overall, this research has demonstrated the widespread presence of imipenem resistant bacteria in environmental and clinical settings, carrying multiple resistances to other antibiotics. In particular, imipenem resistant Stenotrophomonas spp. were present in all of the environments studied and these bacteria were found to harbour multiple and diverse antibiotic resistance genes, that differed between isolates from environmental and clinical origins

Report of Commissioner of General Land Office, 1870.

Annual Message to Congress with Documents; Pres. Grant. 5 Dec. HED 1, 41-3, v1-4, 3417p. [1445-1450] Continued reform of Indian management by making it a missionary work; agencies given over to religious denominations; annual report of the Sec. of War (Serials 1446-144 7); annual report of the Sec. of Interior (Serials 1449-1450); annual report of the Gen. Land Office (Serial 1449); annual report of the CIA (Serial 1449), including difficulties with Plains Indians and Indians in Montana (the Piegan band of Blackfeet Indians), trust funds, the government\u27s Quaker policy, Sioux delegation in Washington, D.C., census, and reports of Supts., agents, and schools; etc

UA3/1/3 Scrapbook 1

Clippings from Orison Marden\u27s magazine Success on various topics between 1899 and 1900 created by Henry Cherry when he was president of the Southern Normal School

Contributions of all peoples to America's making.

Thesis (M.A.)--Boston Universit