58 research outputs found

    The Influence of Drying on the Physical Properties of Sweet Potato Slices

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    The effects of varying drying conditions on the physical properties of sweet potato slices were studied. Fresh tubers were peeled, washed and cut into two shapes (rectangular: 50 x 60 mm and cylindrical 60 mm diameter) and two thicknesses (4 and 6mm) slices. Some slices were blanched in water at 90 oC for 5 mins and some untreated. The slices were dried in the sun or oven (50 oC , 70 oC , 90 oC ). The bulk density, dimensional changes and moisture loss were investigated. Moisture loss and percent shrinkage increased with higher temperature and longer drying time. 4mm thick samples lost more moisture and higher % shrinkage than 6mm thick samples, although not significantly (P>0.05). Logarithmic equations gave best fit of moisture loss with time at the different temperatures. Initial sample thickness had a greater impact on shrinkage than sample shape. Blanching minimized % shrinkage although not significantly (P>0.05). Greater shrinkage took place in the sample thickness (up to 63%) than across product diameter or length (values up to 26.3%). % shrinkage can be predicted using either the linear or logarithmic equations. The bulk densities of dried sweet potato slices were not influenced by blanching. Keywords: moisture content, drying kinetics, blanching, dimensional changes, bulk density

    Background Radiation from 238U, 232Th, and 40K in Bells Area and Canaan City, Ota, Nigeria

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    Natural radionuclides are present in every constituent of the environment. Monitoring of environmental radionuclides is very vital to avoid exposure above the threshold limit. Due to this, the background radiation from 238U, 232Th, and 40K of Bell University of Technology and Canaan Land City was determined from 20 sample points each in the two areas using RS230 Gamma Spectrometer. The mean activity concentration of 40K, 238U, and 232Th for Bells University of Technology was 442.66 Bq/kg, 41.98 Bq/kg, and 48.35 Bq/Kg, respectively. In Canaan City, mean activity concentration of 40K, 238U, and 232Th was 373.65 Bq/kg, 18.85 Bq/kg, and 67.22 Bq/kg, respectively. The mean absorbed dose rates recorded by the spectrometer directly were 70.03 nGy/h and 66.65 nGy/h, while that estimated from the activity concentration were 67.06 and 64.89 nGy/h for Bells University and Canaan City, respectively. The measured and estimated absorbed dose rates were higher than the safe limit of 57 nGy/h. The mean values of other radiological parameters estimated, except that of the gamma index and excess lifetime cancer risk were lower when compared to the recommended limit. It could be concluded that the possibility of suffering any radiation risk is low in these two areas, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above

    Diversity in CO2 concentrating mechanisms among chemolithoautotrophs from genera Hydrogenovibrio, Thiomicrorhabdus, and Thiomicrospira, ubiquitous in sulfidic habitats worldwide

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    Members of Hydrogenovibrio, Thiomicrospira and Thiomicrorhabdus fix carbon at hydrothermal vents, coastal sediments, hypersaline lakes, and other sulfidic habitats. The genome sequences of these ubiquitous and prolific chemolithoautotrophs suggest a surprising diversity of mechanisms for dissolved inorganic carbon (DIC) uptake and fixation; these mechanisms are verified here. Carboxysomes are apparent in transmission electron micrographs of most of these organisms; lack of carboxysomes in Thiomicrorhabdus sp. Milos T2 and Tmr. arctica, and an inability to grow under low DIC conditions by Thiomicrorhabdus sp. Milos T2 are consistent with an absence of carboxysome loci in their genomes. For the remaining organisms, potential DIC transporters from four evolutionarily distinct families (Tcr0853/0854, Chr, SbtA, SulP) are located downstream of carboxysome loci. Transporter genes collocated with carboxysome loci, as well as some homologs located elsewhere on the chromosomes, had elevated transcript levels under low DIC conditions, as assayed by qRT-PCR. DIC uptake was measureable via silicone oil centrifugation when a representative of each of the four types of transporter was expressed in Escherichia coli. Expression of these genes in carbonic anhydrase-deficient E. coli EDCM636 enabled it to grow under low DIC conditions, consistent with DIC transport by these proteins. The results from this study expand the range of DIC transporters within the SbtA and SulP transporter families, verify DIC uptake by transporters encoded by Tcr_0853 and Tcr_0854 and their homologs, and introduce DIC as a potential substrate for transporters from the Chr family. IMPORTANCE Autotrophic organisms take up and fix DIC, introducing carbon into the biological component of the global carbon cycle. The mechanisms for DIC uptake and fixation by autotrophic Bacteria and Archaea are likely to be diverse, but have only been well-characterized among "Cyanobacteria". Based on genome sequences, members of Hydrogenovibrio, Thiomicrospira and Thiomicrorhabdus have a variety of mechanisms for DIC uptake and fixation. We verified that most of these organisms are capable of growing under low DIC conditions, when they upregulate carboxysome loci and transporter genes collocated with these loci on their chromosomes. When these genes, which fall into four evolutionarily independent families of transporters, are expressed in E. coli, DIC transport is detected. This expansion in known DIC transporters across four families, from organisms from a variety of environments, provides insight into the ecophysiology of autotrophs, as well as a toolkit for engineering microorganisms for carbon-neutral biochemistries of industrial importance

    Stochastic upscaling of hydrodynamic dispersion and retardation factor in a physically and chemically heterogeneous tropical soil

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    [EN] Stochastic upscaling of flow and reactive solute transport in a tropical soil is performed using real data collected in the laboratory. Upscaling of hydraulic conductivity, longitudinal hydrodynamic dispersion, and retardation factor were done using three different approaches of varying complexity. How uncertainty propagates after upscaling was also studied. The results show that upscaling must be taken into account if a good reproduction of the flow and transport behavior of a given soil is to be attained when modeled at larger than laboratory scales. The results also show that arrival time uncertainty was well reproduced after solute transport upscaling. This work represents a first demonstration of flow and reactive transport upscaling in a soil based on laboratory data. It also shows how simple upscaling methods can be incorporated into daily modeling practice using commercial flow and transport codes.The authors thank the financial support by the Brazilian National Council for Scientific and Technological Development (CNPq) (Project 401441/2014-8). The doctoral fellowship award to the first author by the Coordination of Improvement of Higher Level Personnel (CAPES) is acknowledged. The first author also thanks the international mobility grant awarded by CNPq, through the Sciences Without Borders program (Grant Number: 200597/2015-9). The international mobility grant awarded by Santander Mobility in cooperation with the University of Sao Paulo is also acknowledged. DHI-WASI is gratefully thanked for providing a FEFLOW license.Almeida De-Godoy, V.; Zuquette, L.; Gómez-Hernández, JJ. (2019). Stochastic upscaling of hydrodynamic dispersion and retardation factor in a physically and chemically heterogeneous tropical soil. 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    Selective AKR1C3 inhibitors do not recapitulate the anti-leukaemic activities of the pan-AKR1C inhibitor medroxyprogesterone acetate

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    Background: We and others have identified the aldo-keto reductase AKR1C3 as a potential drug target in prostate cancer, breast cancer and leukaemia. As a consequence, significant effort is being invested in the development of AKR1C3-selective inhibitors. Methods: We report the screening of an in-house drug library to identify known drugs that selectively inhibit AKR1C3 over the closely related isoforms AKR1C1, 1C2 and 1C4. This screen initially identified tetracycline as a potential AKR1C3-selective inhibitor. However, mass spectrometry and nuclear magnetic resonance studies identified that the active agent was a novel breakdown product (4-methyl(de-dimethylamine)-tetracycline (4-MDDT)). Results: We demonstrate that, although 4-MDDT enters AML cells and inhibits their AKR1C3 activity, it does not recapitulate the anti-leukaemic actions of the pan-AKR1C inhibitor medroxyprogesterone acetate (MPA). Screens of the NCI diversity set and an independently curated small-molecule library identified several additional AKR1C3-selective inhibitors, none of which had the expected anti-leukaemic activity. However, a pan AKR1C, also identified in the NCI diversity set faithfully recapitulated the actions of MPA. Conclusions: In summary, we have identified a novel tetracycline-derived product that provides an excellent lead structure with proven drug-like qualities for the development of AKR1C3 inhibitors. However, our findings suggest that, at least in leukaemia, selective inhibition of AKR1C3 is insufficient to elicit an anticancer effect and that multiple AKR1C inhibition may be required

    Health and climate related ecosystem services provided by street trees in the urban environment

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    Environmental effects of ozone depletion, UV radiation and interactions with climate change : UNEP Environmental Effects Assessment Panel, update 2017

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    Genetic divergence of Nigerian and Indian pearl millet accessions based on agronomical and morphological traits

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    The study assessed the genetic diversity of pearl millet accessions grown in Nigeria and India based on morpho-agronomic traits in order to identify genotypes with superior characters which could be utilized in breeding programmes. Twenty-four pearl millet accessions were grown and evaluated for agronomic and morphological traits during the dry and wet seasons of 2015-2016. Data collected on the accessions using standard descriptors were analysed statistically. IP22281 had the highest mean plant height (108.90 cm) while NGB00531 recorded the lowest (61.02 cm). Significant intra-specific variation existed in number of leaves per plant, leaf length, leaf width, number of nodes and internode length, however, stem girth was similar for the accessions. Tillering was generally poor with the highest value (1.60 tillers per plant) found in NGB00531. A significant positive correlation occurred between plant height, number of leaves, leaf length and leaf width. Panicles emerged between 44 and 56 days and NGB00548 had the shortest maturity time. Also, panicle length and peduncle diameter varied significantly for the accessions. The highest grain yield and 1000-grain weight were recorded in NGB00616 and the lowest yield and weight were recorded in IP22269. The principal component analysis grouped the accessions into four clusters, comprising mixtures of Nigerian and Indian members. Similarly, the dendrogram grouped the accessions into two main groups which were sub-divided into smaller clusters with accessions from Nigeria and India in the same cluster. The study concludes that variations in morpho-agronomic and yield characters among the accessions studied could be harnessed for crop improvement. The clustering pattern of these accessions indicated their genetic relatedness, possibly from the same progenitor, but separation by geographical or ecological isolation mechanisms

    Mapping And Spatial Analysis Of Polling Units To Enhance Voting In Akure South, Nigeria

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    Polling units are isolated places with significant structures established by the Independent National Electoral Commission in Nigeria to serve as registration centers and voting units. The study aimed at mapping and examining the spatial distribution of polling units to enhance the voting process in Akure South, Ondo State. Handheld-GPS map 76CSX was used in acquiring coordinates of the existing polling units. Queries were performed to examine the ownership of the polling unit premises and also determine polling units with over 500 registered voters. The result of the query shows that 276 out of the 302 polling units in the study area have over 500 voters. The distribution pattern of the polling units was determined using the average Nearest Neighbour Analysis. The result indicates clustered with Rn as 0.502292 and Z- value is -16.546600 less than 1. Geocoding was done to ease accessibility and navigation to polling units. A map depicting the polling units' locations and landmarks was produced using ArcGIS 10.6, and it was revealed that some polling units allocated for the study area fall into surrounding Local Governments. It is worthy to note that the results of this study should be adopted, as it would efficiently enhance the voting process
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