1,720,976 research outputs found
Genomic context analytics of genes for universal stress proteins from petroleum-degrading Alcanivorax
Get PDFAlcanivorax species are gram negative bacteria that usually require aliphatic hydrocarbon
as the sole carbon source for growth. The ability to use petroleum in polluted environments as
energy source makes Alcanivorax species biotechnologically relevant in bioremediation.
Universal stress proteins confer ability to respond to unfavourable environments, thus the present
study was done to analyse the genomic context of genes for universal stress proteins in
Alcanivorax genomes. A combination of bioinformatics and visual analytics approaches were
used to analyze genome-enabled data including sequences and gene expression datasets. On the
basis of transcription unit and adjacent genes, two types of Alcanivorax USP genes observed
were (i) adjacent to cyclic nucleotide-binding and oxygen sensing functions; and (ii) adjacent to
sulfate transporter function. Both types of genes encode two universal stress protein domains
(pfam00582) also referred to as tandem-type universal stress proteins. The sequence and structural characteristics of each of the four USP domains in Alcanivorax needs to be further
investigated. This dissertation research evaluated data from Alcanivorax borkumensis cells
(grown on either pyruvate or hexadecane as carbon source) that were stressed with 1-octanol and
data collected at 15 min, 30 min, 60 min and 90 min after 1-octanol addition. The two genes for
Alcanivorax borkumensis SK2 universal stress proteins, ABO_1340 and ABO_1511, had the
same direction of expression for adjacent genes. A limitation of this research was that findings
based on bioinformatics and visual analytics methods may need confirmation by molecular
methods. The differences observed may also reflect the quality of the annotations provided for
genes. The sequence and structural characteristics of each of the four USP domains in
Alcanivorax needs to be further investigated. Further research is needed on the relationship
between number, length and order of genes in operons that include genes for universal stress proteins. Additionally, in vitro studies to confirm the functional prediction made from the
genomic context of the universal stress protein in Alcanivorax genome. The knowledge
discovered from this genome context analytics research could contribute to improving the
performance of Alcanivorax species in bioremediation of environments polluted with petroleumM. Sc. (Environmental Science)College of Agriculture and Environmental Science
Performance evaluation of pilot-scale constructed wetlands for the treatment of domestic wastewater in Addis Ababa, Ethiopia
Get PDFAn experimental study was carried out to evaluate the performance of pilot scale constructed wetlands for
the treatment of domestic wastewater in Addis Ababa, Ethiopia. Three parallel sets of constructed
wetlands; consisting of one Horizontal Flow (HF), one Vertical Flow (VF) and one hybrid of HF and VFconstructed
in series were built in Addis Ababa. The wetland systems had identical wetland fill media and
macrophytes but with different wastewater flow types. The total surface area of the wetland systems was
72 m2 /24 m2 for each/ and designed to treat 3.15 m3 of domestic wastewater per day. Triplicate grab
samples were taken from the influent and effluents every 15 days for one year and analyzed within 24
hours. Temperature, pH, DO and EC were measured onsite and the nutrient content of macrophytes was
determined twice during the monitoring period.
During the first 12 months monitoring period, the average removal efficiencies of the HFCW, VFCW and
hybrid CW were: BOD (89.1%, 92.2% and 93.4%), COD (80.6%, 82.1% and 84.0%), TSS (89.1, 83.8%
and 84.7%), NH4
+ (58.6%, 66.2% and 65.4%), NO3
- (64.0%, 71.5% and 73.5%), TN (49.1%, 54.9% and
58.7%), PO4
3- (45.4%, 50.3% and 48.4%), TP (58.0%, 51.7% and 54.4%) and FC (98.6%, 96.6% and
96.5%), respectively. The hybrid system showed relatively higher removal efficiencies for most
pollutants. Again, the wetland systems showed relatively higher percent reduction during the dry seasons
/from Dec - May/. The areal removal rate constants of BOD5, TN, PO4
3- and TP were higher than the
literature values while the values of COD and TSS were lower compared to the literature values.
Concerning the nutrient content of the wetland plant, the average TN contents of the below-ground and
above-ground plant part were 1.56% and 2.27% for the HFCW, 1.75% and 2.74% for the VFCW and
1.80% and 2.63% for the hybrid system, respectively. Meanwhile, the average TP contents of the belowground
and above-ground plant part were 0.139% and 0.064% for the HFCW, 0.167% and 0.067% for the
VFCW and 0.115% and 0.065% for the hybrid systems, respectively.
In general, the results showed that properly designed constructed wetland systems could be used as
effective wastewater treatment method in Ethiopia.Ph. D. (Environmental Sciences)Environmental Science
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Microbial communities in field-scale oil-polluted soil remediation using 16S rRNA amplicon sequencing
No full textThis investigation employed 16S rRNA amplicon sequencing to understand microbial dynamics during a 2-month field-scale oil-impacted soil remediation in the Niger Delta. Surface soil (0.0–0.5 m) had extractable total petroleum hydrocarbons (ETPH) concentrations of 6231 mg/kg and subsurface samples from 1.0 m, 1.5 m and 2.0 m depths had 4836 mg/kg, 9112 mg/kg and 7273 mg/kg, respectively. Proteobacteria dominated the bacterial community of the oil-polluted soil and comprised mainly Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. Alpha diversity analysis revealed the presence of hydrocarbons reduced microbial diversity. Principal coordinate analysis indicated that the community structure continually changed following variations in the ETPH concentrations. Mycobacterium, Burkholderia, Methylobacterium and Bacillus were among the core operational taxonomic units (OTUs) detected during remediation. Significant variation in predicted pathway abundance, particularly pathways for fatty acid metabolism, propanoate, benzoate, polycyclic aromatic hydrocarbons, naphthalene and xenobiotics degradation, was more apparent in samples obtained during remediation than in the reference contro
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