89 research outputs found
Characterization of Legionella pneumophila Effector Proteins, LneB and MavA
Get PDFThe crucial virulence factor of accidental human pathogen Legionella pneumophila during the course of Legionnaire disease is the over 300 effector proteins secreted from its Dot/Icm secretion system. Eukaryotic host cells usually elicit an arsenal of immune responses against invading L. pneumophila. Nonetheless, the bacteria unexpectedly subvert these defense mechanisms to survive and proliferate unhindered in the host. Although some effector proteins have been proposed to play a significant role in this host-pathogen interaction, many still need to be characterized. The LneB and MavA proteins are examples of those effectors that need characterization. Thus, this study aimed to investigate the structural and functional characteristics of LneB and MavA proteins using several bioinformatics predictive pipelines and transcriptomics data supplemented experimentally through cell-based and biochemical assays to support the prediction.
The LneB protein was predicted to have histone acetylation activity (HAT) based on bioinformatics analysis. To investigate the HAT activity of LneB in vitro, the protein was ectopically expressed in the Escherichia coli BL21 strain and purified using nickel ion chromatography. The HAT activity assay was carried out on the purified LneB protein and on the nuclear extracts from LneB-GFP transfected 293T cells. Transcriptomics analysis shows that the LneB protein differentially induces upregulation of early growth factor and dehydrogenase (DHRS2) compared to the GFP control.
There was no significant difference between the in vitro HAT activity of LneB protein and the elution buffer (p-value = 0.1137, t-value = 5.537). In vivo, HAT activity was significantly reduced in cells transfected with LneB protein compared to the GFP control (p-value = 0.0025, t-value = 20.08). The HAT activity is not significantly different at a MOI of 10 or 100 when infected cells (Dot/Icm mutant and wild-type L. pneumophila) are compared to uninfected U937 cells (p-value = 0.8969 and 0.5384, respectively). However, the HAT activity in cells infected with an L. pneumophila Dot/Icm mutant at MOI of 100 was significantly lower than in cells that were not infected (p-value = 0.0236). This result suggests that the effector protein from the wild type plays a significant role in acetylating histone protein in the host. Further investigation is required to understand the HAT activity of LneB and other roles the protein could play in the host.
Our bioinformatics analysis suggested that the MavA protein possesses Ras-GEF domains and potentially binds to GTP. The protein is predicted to possess two coiled-coil domains and also interact with GTP, Ras and actin. The transcriptomic data from cells expressing MavA protein showed significant upregulation of sixteen genes, which are involve in steroid hormone metabolic processes, endocytic recycling, cilia movement among others. The sortilin receptor protein was the only repressed gene in the cell when compared to a GFP protein control. Connecting the bioinformatics finding and the review of literature, we suggested that the MavA protein could be involved in the biological process in the cell such as internalization of L. pneumophila, creation of Legionella-containing vacuoles in host cells through endosomal remodeling or cytoskeletal reorganization
Monosodium Glutamate (MSG)-Induced Male Reproductive Dysfunction: A Mini Review
No full textReproductive dysfunction is often characterized by malfunction of the reproductive tissues, which may lead to disruption of the synergistic rhythm that should bring about a progression of sexual events and the conception of new life. This may therefore result in the sexual dysfunction and infertility that can be seen in couples having prolonged biological difficulty in reproducing their offspring after having unrestricted sexual intercourse for at least twelve months. Several factors have been implicated in the cause and progression of reproductive dysfunction, including poor nutrition, drug side effects, disease states, and toxicant ingestion. A well-known food additive that has been found to be potent at initiating reproductive anomalies in males is monosodium glutamate (MSG). This regular flavor enhancer is widely used as a taste enhancer in several diets. The different mechanisms by which it may induce reproductive dysfunctions include spermatogenic alteration resulting in a low sperm count, high sperm abnormality, reduced live sperm and decreased sperm pH, oxidative damage (increased lipid peroxidation and reduced antioxidant enzyme activities), histological alteration (blood hemorrhage, distorted germ and Sertoli cells), as well as gonadotropin imbalance (reduced testosterone, luteinizing hormone, and follicle-stimulating hormone concentrations). Therefore, this review discusses various established mechanisms through which MSG may induce reproductive dysfunction and the treatment strategies to ameliorate its toxic effects
A modified anthrax toxin-based enzyme-linked immunospot assay reveals robust T cell responses in symptomatic and asymptomatic Ebola virus exposed individuals.
Get PDFBackgroundEbola virus (EBOV) caused more than 11,000 deaths during the 2013-2016 epidemic in West Africa without approved vaccines or immunotherapeutics. Despite its high lethality in some individuals, EBOV infection can produce little to no symptoms in others. A better understanding of the immune responses in individuals who experienced minimally symptomatic and asymptomatic infection could aid the development of more effective vaccines and antivirals against EBOV and related filoviruses.Methodology/principle findingsBetween August and November 2017, blood samples were collected from 19 study participants in Lagos, Nigeria, including 3 Ebola virus disease (EVD) survivors, 10 individuals with documented close contact with symptomatic EVD patients, and 6 control healthcare workers for a cross-sectional serosurvey and T cell analysis. The Lagos samples, as well as archived serum collected from healthy individuals living in surrounding areas of the 1976 Democratic Republic of Congo (DRC) epidemic, were tested for EBOV IgG using commercial enzyme-linked immunosorbent assays (ELISAs) and Western blots. We detected antibodies in 3 out of 3 Lagos survivors and identified 2 seropositive individuals not known to have ever been infected. Of the DRC samples tested, we detected antibodies in 9 out of 71 (12.7%). To characterize the T cell responses in the Lagos samples, we developed an anthrax toxin-based enzyme-linked immunospot (ELISPOT) assay. The seropositive asymptomatic individuals had T cell responses against EBOV nucleoprotein, matrix protein, and glycoprotein 1 that were stronger in magnitude compared to the survivors.Conclusion/significanceOur data provide further evidence of EBOV exposure in individuals without EVD-like illness and, for the first time, demonstrate that these individuals have T cell responses that are stronger in magnitude compared to severe cases. These findings suggest that T cell immunity may protect against severe EVD, which has important implications for vaccine development
PRICE REPORTING in A THIN MARKET
Get PDFCitation: Ajewole, K., Schroeder, T. C., & Parcell, J. (2016). PRICE REPORTING in A THIN MARKET. Journal of Agricultural and Applied Economics, 48(4), 345-365. doi:10.1017/aae.2016.19Thin markets create challenges for reporting market information by the U.S. Department of Agriculture (USDA) and for users of the information. This study examines distributions of transactions comprising daily price reports in the U.S. hog market. We determine publicly reported daily prices are sensitive to which packing plants buy hogs. Transaction prices comprising USDA Agricultural Marketing Service price reports are not normally distributed; care must be taken in reporting and interpreting transaction prices. Economically important variations in prices occur because of packer-specific indicators. Daily reported prices are used as base prices in marketing agreements, making variation of even greater importance. Copyright © The Author(s) 2016
Single-label machine learning classification revealed some hidden but inter-related causes of five psychotic disorder diseases
Get PDFPsychotic disorder diseases (PDD) or mental illnesses are group of illnesses that affect the minds and impair the cognitive ability, retard emotional ability and obstruct the process of communication and relationship with others and are characterized by delusions, hallucinations and disoriented or disordered pattern of thinking. Prognosis of PDD is not sufficient because of the nature of the diseases and as such adequate form of diagnosis is required to detect, manage and treat the illness. This paper applied the single-label classification (SLC) machine learning approach in mining of electronic health records of people with PDD in Nigeria using eleven independent (demographic) variables and five PDD as target variables. The five PDDs are Insomnia, Schizophrenia, Minimal Brain dysfunction (MBD), which is also known as Attention-Deficit/Hyperactivity Disorder (ADHD), Vascular Dementia (VD) and Bipolar Disorder (BD). The aim of using SLC is that it would be easier to detect some PDDs that are related to each other without the loss of information, which is a plus over multi-label classification (MLC). ReliefF algorithm was used at each experiment to precipitate the order of importance of the independent variables and redundant variables were excluded from the analysis. The order of the variables in feature selection was matched with feature importance after the classifications and quantified using the Spearman rank correlation coefficient. The data was divided into: 70% for training and 30% for testing. Four new performance metrics adapted from the root mean square (RMSE) were proposed and used to measure the differences between the performance results of the 10 Machine learning models in terms of the training and testing and secondly, feature and without feature selection. The new metrics are close to zero which is an indication that the use of feature selection and cross validation may not greatly affects the accuracy of the SLC. When the PDDs are included as predictors for classifying others, there was a tremendous improvement as revealed by the four new metrics for classification accuracy (CA), precision and recall. Analysis of variance showed the four different metrics differs significantly for classification accuracy (CA) and precision. However, there were no significant difference between the CA and precision when the duo are compared together across the four evaluation metrics at p value less than 0.05
Demilitarisation Nigeria and South Africa compared
Get PDFIn sub-Saharan African countries that have made democratic transition from military
rule and military-backed authoritarian regimes, state elites have embarked upon
strategies aimed at demilitarising the new democratic political process. Demilitarisation
of the state and politics has become an imperative because it is decisive for
consolidating democratic politics and for ensuring improvements in public safety and
security. Yet the process of such demilitarisation in these countries has often generated
a paradox, whereby the reduction of the political influence of state institutions of
violence has been associatedw ith rising civil militarism and the prevalenceo f organised
violence in the wider society.
In these circumstances, taking cognisance of the dangers of civil militarism and other
forms of private violence is a priority for designing and implementing demilitarisation
strategies and other security reforms in post-authoritarian African states. Reformminded
political elites and external supporters need to be sensitive to these dangers or
risk perpetuating the shell of electoral democracy that cannot deliver the goal of human
security in the region. This dissertation explored how the current approach to
demilitarisation is related to the problem of civil militarism by examining the case
studies of Nigeria and South Africa. It explains that given the condition of the state in
Africa, demilitarisation of politics after transition from military or military-backed
authoritarianism contributes to the emergence of civil militarism. Based on this finding,
it argues for a comprehensive approach to demilitarisation as a strategy that caters to
both state and societal violence in order to mitigate the risks of civil militarism in the
process
Review Policy Moderates the Correlation Between CiteScore and JIF For BMC Journals
Get PDFThis article examines the relationship between four review policies (RP) run by different
BioMed Central (BMC) journals, namely single-blind peer review (SBPR), double-blind
peer review (DBPR), open peer review (OPR), and transparent peer review (TPR), and
CiteScore and Journal impact factor (JIF). As of December 12, 2021, BMC publishes
306 journals, of which 14 were discontinued. The final data set was 213 journals with
data on CiteScore and JIF. Descriptive statistics and the use of violin and mosaic plots
were used. Normality tests were conducted and non-parametric correlation and analysis
of variance and Mann Whitney tests were used. Moderation analysis was used to
assess the extent of the relationship between CiteScore and JIF. 14 (4.8%) are run with
DBPR, and 22 (7.5%), 211 (72.3%) and 45 (15.4%) are run with OPR, SBPR and TPR
respectively. Analysis of the final dataset shows that the mean, median, and standard
deviation of the CiteScore of the 213 journals are 5.64, 4.80, and 3.65, respectively,
while the mean, median, and standard deviation of the JIF of the 213 journals are 4.27,
3.36 and 2.90. In descending order, the CiteScore and JIF across the four RP are
highest in DBPR, SBPR, OPR, and TPR. There is a strong positive correlation (Spearman rho = 0.87318, p-value < 8.7e-68) between the CiteScore and JIF of the 213
BMC journals. Mann Whitney test (U = 14771.5, Wilcoxon W = 37562.5, Z = −6.228, pvalue
< 0.000) shows that there is an evidence of significance median differences
between the CiteScore and JIF of the 213 journals. There are significant median
differences in the CiteScore in JIF across the four review policies. Finally, the RP
moderates the relationship between CiteScore and JIF and between JIF and CiteScore,
respectively. This article reveals that the review policies adopted by BMC journals are
somewhat related to the journal metrics that measure the impact, prestige, relevance,
and acceptability of the respective journals
DETERMINANTS OF INFLATION IN NIGERIA: A CO- INTEGRATION APPROACH
Get PDFInflation is undeniable one of most leading and dynamics macroeconomics issues confronting almost all economies of the world. Its dynamism has made it an imperative issue to be considered. Hence the study examines the factors affecting inflation in Nigeria. Time series data were employed for the study. The data was sourced from the Central Bank of Nigeria and National Bureau of Statistics. Descriptive statistics and cointegration analysis were the analytical tools used. It was observed that there were variations in the trend pattern of inflation rate. Some of the variables considered were significant in determining inflation in Nigeria. The previous total export was found to have a negative impact on current inflation while the previous total import exerts a positive effect likewise the food price index. It has thus been recommended that policies that will set the interest rate to a level at which it will encourage investment and increase in production level could be institutionalized, importation should be reduced in Nigeria such that it will not encourage change of consumer taste resulting to inflating prices, exchange rate system should be maintained at a level that will not impose threat on the Nigeria economy and the domestic consumption of petroleum product should be focused, not only exportation.Financial Economics,
Development of a Short Term Solar Power Forecaster Using Artificial Neural Network and Particle Swarm Optimization Techniques (ANN-PSO)
Get PDFGlobally, the use of renewable energy has increased significantly since the late
twentieth century. Nigeria is also leading the exponential growth of renewable
energy use. This article will predict the solar energy collected in 11 power
distribution company areas (DISCO) in Nigeria: Abuja, Benin, Eko, Enugu,
Ibadan, Ikeja, Jos, Kaduna, Kano, Port-Harcourt, and Yola. Artificial Neural
networks and Particle Swarm Optimization (ANN-PSO) techniques are used to
forecast solar irradiance. This research compares the results using cognitive
acceleration coefficients. From this study, the regression coefficient (R) values
of 0.9968 and 0.99533 were obtained from Yola and Ikeja Distribution
Company, respectively. Also, mean absolute percentage error (MAPE) values of
3.07% in Yola and 5.67% in Jos were obtained. The normalized root means
square error (nRMSE) values of 0.9813, 2.4522, and 0.9470 were obtained from
Yola, Ikeja, and Benin DISCOs, respectively, and mean squared error (MSE)
values of 2.29% in Abuja, 1.80% in Ibadan, 1.83% in Ikeja, and 0.0915% in Jos.
The simulation was also performed for July 2021, which was not part of the
dataset used in this study. The result of the forecaster revealed high levels of
forecasting accuracy
Ecological assessment of Black Fly (Simuliumdamnosum, Sensulato) breeding sites in two tributaries of Ogun river, Ogun state, Nigeria.
No full textpeer reviewedOnchocerciasis is a disease transmitted by blackfly vector of the genus Simuliumdamnosum complex having public and socio-economic consequences. The abundance of blackfly is directly linked to fluvial ecosystems in both tropical and non-tropical countries of the world. This study assessed the ecology of blackfly breeding sites in two tributaries of River Ogun located in Olokemeji and Lisa villages, Ogun State. A total of eighteen water samples were collected for physicochemical analysis during high rainfall (May, June and July), low rainfall (August, September and October) and dry season (November and December) with mean rainfall values of 163.17, 88.03 and 8.95 mm, respectively, in both tributaries. Physicochemical parameters such as temperature (oC), electrical conductivity (EC), pH, total solids (TS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), hardness (H), sulphate (SO4), phosphate (PO4), alkalinity, acidity, nitrate (NO3) and total dissolved solids (TDS) were analysed using standard laboratory methods. Digestive enzymes were analysed using 1 g of frozen gut of Simulium larvae grounded with 20 ml of 0.067 g of potassium hydrogen and 20 ml of 0.1 M sodium reagent. A total of 766 and 482 samples of Simulium larvae were collected from Olokemeji and Lisa tributaries using Eppendorf tubes. The zooplanktons collected from Olokemeji and Lisa tributary were 904 and 802, while phytoplanktons collected from Olokemeji and Lisa tributary were 635 and 582 during the study period. Data obtained were analysed using both descriptive analysis and T-test. The results obtained for the physicochemical parameters were 28.7 °C, 137.5 µS/cm, 6.3, 248.1 mg/L, 58 mg/L, 108.8 mg/L, 90.8 mg/L, 2.24 mg/L, 2.24 mg/L, 30.76 mg/L, 42.35 mg/L, 1.99 mg/L, 2.07 mg/L and 2.55 mg/L for Temperature, EC, pH, TS, DO, BOD, TSS, H, SO4, PO4, alkalinity, acidity, NO3 and TDS, respectively. There were significant (p < 0.05) differences between the means of EC, pH, TS, TDS, TSS and hardness of Lisa tributary, and water samples were also viewed under an electron microscope for zooplanktons and phytoplanktons. The values of species diversity which were greater than 0.5 indicated that the species were abundant and evenly distributed. There were significant (p < 0.05) differences between the tributaries in all the digestive enzymes except amylase content. The regression analysis between TSS, nitrate, sulphate, phosphate, acidity, hardness, TS, pH and Simulium larvae abundance showed a positive correlation, R2 with values of 0.828, 0.994, 0.948, 0.933, 0.986, 0.997, 0.889 and 0.981, respectively. The R2 values between Simulium larvae abundance with phytoplanktons and rainfall have values of 0.868 at p < 0.01 and 0.911 at p < 0.05
- …
