464 research outputs found

    Targeting NIR Tissue Test Sampling Using Aerial Imagery And Identifying The Factors Causing Variable Rice Growth And Crop Yields.

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    The new precision agriculture tool, aerial infrared images has created an opportunity for rice farmers to assess crop variability. At ground level variability is difficult to assess. Aerial infrared images readily show crop variability. The images supplied by Terrabyte Services show 5 colour image zones of crop vigour from low vigour to high vigour. The identified zones can show farmers where to sample crops for the NIR Tissue Test at panicle initiation. Previously farmers randomly sampled not really knowing whether the sampled areas were really representative of the crop. The ability of the aerial images to show crop vigour differences has led to the issue of how farmer crops compare to each other and what factors cause variability within crops. This project reports on the use of spatial infrared aerial imagery in the rice industry. It reports on two sub-projects. The first is the introduction and farmer use and adoption of aerial infrared imaging for identifying variability. The second sub-project reports on the identification of factors causing crop growth and grain yield variability. The outcomes from the first sub-project have been very successful. After the first season there was great feedback. Farmer quotes include: “There was more crop variation than I thought” “I was surprised by cut and fill areas showing up after 20 years” “The aerial images are an excellent tool at PI meetings” “The variation is often not due to nitrogen” 2 Over the first 2 years the number of farmer participants increased from 270 to 549, crop numbers from 484 to 834 and crop area from 14000ha to 29500ha. Although the 2005 rice crop area was lower at 44,000 ha compared to 65000 ha in the 2004 season, 29000 ha was imaged representing 66% of the total area. This compares to 47% in 2003/04. Perhaps the key outcome from the project is that aerial imagery has been successfully adopted by rice farmers and is now seen as an essential tool for improving the management of rice crops. The second sub-project has shown there is large yield variability and large factor variability within crops and between crops. The yield coefficient of variation (CV) of the monitored crops ranged from 4% to 76% in the 2003/04 season. The variation of measured parameters within the one crop eg plant number, water depth, N uptake has been surprisingly high with the CV often as high as 60-80%. There is a need to gain an understanding of the reasons for this variability which will be the subject of further analysis of the data. The future challenge for the rice industry and rice farming systems is to identify all the factors contributing to rice growth and yield variability and finding ways of overcoming the variability leading to more uniform and higher yielding crops

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    Woody species composition and congregant appreciation of the cultural and spiritual services provided by cemeteries and church gardens in Grahamstown, South Africa

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    Urbanization has increased rapidly throughout the world. The densification of urban areas has greatly reduced the number of natural areas occurring within the urban environment as well as impacting the ecosystem services that these areas provide. Urban greening and sustainable practices have been advocated as a means to once again provide the urban population with ecosystem services. Sacred natural areas that occur in surrounding forest, temple and cemetery sites have been known harbour a variety of biological diversity, as well as provide people with a number of cultural and spiritual benefits. Much of the literature on sacred natural sites comes from rural or eastern countries, leaving a large gap in the knowledge pertaining to information on these sites in both developed nations as well as urban areas. The aim of this study was to determine the abundance and composition of woody species, as well as the spiritual and cultural significance of sacred natural sites in Grahamstown. This study defined a sacred urban area as any form of garden surrounding a church, temple or mosque, as well as cemeteries. It looked at a total of 28 church gardens, one Hindu garden, one Mosque garden and five cemeteries in Grahamstown, South Africa. For each site the area was calculated and a tree and shrub inventory was done for all individuals above 1.5 m tall. Church/cemetery age, denomination and appearance were recorded as well as soil samples collected. An ordination of the data was done to summarize the community data, relating the community variation to environmental gradients. Questionnaires were completed by congregants who attended a religious building with a garden, as well as those that were not surrounded by a garden. These questionnaires were used to determine the cultural, spiritual and aesthetic value of trees and the sacred area, as well as the perceived and felt benefits that these areas provide. Those that were completed by congregants without gardens looked to find out whether or not it was believed that these areas would improve their experiences. There was an average plant density of 106.1 woody plants per hectare, with a total of 139 different species encountered. Of these, 56 percent were exotic species. This is slightly lower than that of studies done elsewhere in the world, but may be due to the omission of non-woody ornamentals and lawn species in this study. Of the top 11 most frequently occurring species, only two were indigenous. There was generally low similarity between plant assemblages found at the different sites. A significantly positive relationship was found between site size and woody plant basal area as well as the total number of woody plants. Site age and religious denomination had little influence on woody plant density, basal area, species richness or woody plant abundance. Congregants stated that a garden surrounding a religious building improved both their spiritual and aesthetic experiences. Stated spiritual and aesthetic experience was significantly influenced by basal area, while abundance significantly influenced stated aesthetic experience. Greenery was therefore important to many of the congregants, however, the species that were present were less influential. A greater sample size from a variety of religions and sacred areas within urban environments throughout the world would prove to be an interesting comparison for future research

    The role of the most luminous, obscured AGN in galaxy assembly at z~2

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    We present HST WFC3 F160W imaging and infrared spectral energy distributions for twelve extremely luminous, obscured AGN at 1.8<z<2.71.8<z<2.7, selected via "Hot, Dust Obscured" mid-infrared colors. Their infrared luminosities span 215×10132-15\times10^{13}L_{\odot}, making them among the most luminous objects in the Universe at z2z\sim2. In all cases the infrared emission is consistent with arising at least in most part from AGN activity. The AGN fractional luminosities are higher than those in either sub-millimeter galaxies, or AGN selected via other mid-infrared criteria. Adopting the GG, M20_{20} and AA morphological parameters, together with traditional classification boundaries, infers that three quarters of the sample as mergers. Our sample do not, however, show any correlation between the considered morphological parameters and either infrared luminosity or AGN fractional luminosity. Moreover, their asymmetries and effective radii are distributed identically to those of massive galaxies at z2z\sim2. We conclude that our sample is not preferentially associated with mergers, though a significant merger fraction is still plausible. Instead, we propose that our sample are examples of the massive galaxy population at z2z\sim2 that harbor a briefly luminous, "flickering" AGN, and in which the GG and M20_{20} values have been perturbed, due to either the AGN, and/or the earliest formation stages of a bulge in an inside-out manner. Furthermore, we find that the mass assembly of the central black holes in our sample leads the mass assembly of any bulge component. Finally, we speculate that our sample represent a small fraction of the immediate antecedents of compact star-forming galaxies at z2z\sim2.Comment: ApJ, accepted. Updated to reflect the accepted versio

    Gas chromatography mass spectrometry (GC-MS) quantification of metabolites in stool using13 C labelled compounds

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    © 2018 by the authors. Licensee MDPI, Basel, Switzerland. It has become increasingly important to qualitatively and quantitatively assess the volatile metabolites in a range of bodily fluids for use in monitoring health. There has been relatively little work on the quantitative analysis of compounds, particularly with respect to the effects of ethnicity or geographic location. A novel method for the quantification of compounds in stool using13 C labelled compounds as internal standards is presented. Using thermal desorption gas chromatography mass spectrometry, stool samples from 38 healthy volunteers were analysed. The13 C labelled compounds, acetone, ethyl butanoate, ethanoic acid, butanoic acid, 3-methylbutanoic acid, and indole, were added as internal standards. This process mimics the solubility characteristics of the compounds and thus the method was able to quantify the compounds within the solid stool. In total, 15 compounds were quantified: Dimethyl sulphide (26–25,626 ng/g), acetone (442–3006 ng/g), ethyl butanoate (39–2468 ng/g), ethyl 2-methylbutanoate (0.3–180 ng/g), dimethyl disulphide (35–1303 ng/g), 1-octen-3-one (12 ng/g), dimethyl trisulphide (10–410 ng/g), 1-octen-3-ol (0.4–58 ng/g), ethanoic acid (672–12,963 ng/g), butanoic acid (2493–11,553 ng/g), 3-methylbutanoic acid (64–8262 ng/g), pentanoic acid (88–21,886 ng/g), indole (290–5477 ng/g), and 3-methyl indole (37–3483 ng/g). Moreover, by altering the pH of the stool to pH 13 in conjunction with the addition of13 C trimethylamine, the method was successful in detecting and quantifying trimethylamine for the first time in stool samples (range 40–5312 ng/g). Statistical analysis revealed that samples from U.K. origin had five significantly different compounds (ethyl butanoate, 1-octen-3-ol, ethanoic acid, butanoic acid, pentanoic acid, and indole) from those of South American origin. However, there were no significant differences between vegetarian and omnivore samples. These findings are supported by pre-existing literature evidence. Moreover, we have tentatively identified 12 compounds previously not reported as having been found in stool
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