ANOSPEX: A Stochastic,Spatially Explicit Model for Studying Anopheles Metapopulation Dynamics

Anopheles mosquitoes transmit malaria, a major public health problem among many African countries. One of the most effective methods to control malaria is by controlling the Anopheles mosquito vectors that transmit the parasites. Mathematical models have both predictive and explorative utility to investigate the pros and cons of different malaria control strategies. We have developed a C++ based, stochastic spatially explicit model (ANOSPEX; Ano phelesSpatially-Explicit) to simulate Anopheles metapopulation dynamics. The model is biologically rich, parameterized by field data, and driven by field-collected weather data from Macha, Zambia. To preliminarily validate ANOSPEX, simulation results were compared to field mosquito collection data from Macha; simulated and observed dynamics were similar. The ANOSPEX model will be useful in a predictive and exploratory manner to develop, evaluate and implement traditional and novel strategies to control malaria, and for understanding the environmental forces driving Anopheles population dynamics.     

Dietary Omega-3 Polyunsaturated Fatty Acids Alter the Fatty Acid Composition of Hepatic and Plasma Bioactive Lipids in C57BL/6 Mice: A Lipidomic Approach

Background

Omega (n)-3 polyunsaturated fatty acids (PUFA) are converted to bioactive lipid components that are important mediators in metabolic and physiological pathways; however, which bioactive compounds are metabolically active, and their mechanisms of action are still not clear. We investigated using lipidomic techniques, the effects of diets high in n-3 PUFA on the fatty acid composition of various bioactive lipids in plasma and liver.

Methodology and Principal Findings

Female C57BL/6 mice were fed semi-purified diets (20% w/w fat) containing varying amounts of n-3 PUFA before mating, during gestation and lactation, and until weaning. Male offspring were continued on their mothers’ diets for 16 weeks. Hepatic and plasma lipids were extracted in the presence of non-naturally occurring internal standards, and tandem electrospray ionization mass spectrometry methods were used to measure the fatty acyl compositions. There was no significant difference in total concentrations of phospholipids in both groups. However, there was a significantly higher concentration of eicosapentaenoic acid containing phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and cholesteryl esters (CE) (p < 0.01) in the high n-3 PUFA group compared to the low n-3 PUFA group in both liver and plasma. Plasma and liver from the high n-3 PUFA group also had a higher concentration of free n-3 PUFA (p < 0.05). There were no significant differences in plasma concentrations of different fatty acyl species of phosphatidylethanolamine, triglycerides, sphingomyelin and ceramides.

Conclusions/Significance

Our findings reveal for the first time that a diet high in n-3 PUFA caused enrichment of n-3 PUFA in PC, LPC, CE and free fatty acids in the plasma and liver of C57BL/6 mice. PC, LPC, and unesterified free n-3 PUFA are important bioactive lipids, thus altering their fatty acyl composition will have important metabolic and physiological roles.     

Analysis and modeling of the variable region of camelid single-domain antibodies

Camelids have a special type of Ab, known as heavy chain Abs, which are devoid of classical Ab light chains. Relative to classical Abs, camelid heavy chain Abs (cAbs) have comparable immunogenicity, Ag recognition diversity and binding affinities, higher stability and solubility, and better manufacturability, making them promising candidates for alternate therapeutic scaffolds. Rational engineering of cAbs to improve therapeutic function requires knowledge of the differences of sequence and structural features between cAbs and classical Abs. In this study, amino acid sequences of 27 cAb variable regions (V(H)H) were aligned with the respective regions of 54 classical Abs to detect amino acid differences, enabling automatic identification of cAb V(H)H CDRs. CDR analysis revealed that the H1 often (and sometimes the H2) adopts diverse conformations not classifiable by established canonical rules. Also, although the cAb H3 is much longer than classical H3 loops, it often contains common structural motifs and sometimes a disulfide bond to the H1. Leveraging these observations, we created a Monte Carlo-based cAb V(H)H structural modeling tool, where the CDR H1 and H2 loops exhibited a median root-mean-square deviation to natives of 3.1 and 1.5 ?, respectively. The protocol generated 8-12, 14-16, and 16-24 residue H3 loops with a median root-mean-square deviation to natives of 5.7, 4.5, and 6.8 ?, respectively. The large deviation of the predicted loops underscores the challenge in modeling such long loops. cAb V(H)H homology models can provide structural insights into interaction mechanisms to enable development of novel Abs for therapeutic and biotechnological use.     

Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria

Animals including food animals play a significant role in the epidemiology of Salmonella enterica. The control requires identification of sources and institution of targeted interventions. This study investigates the diversity of S. enterica serovars, antimicrobial susceptibility, and occurrence of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain reaction. The 229 Salmonella isolates were made of 50 serovars predominated by rare serovars Salmonella Give (n?=?36; 15.7 %), Salmonella Brancaster (n?=?17; 7.4 %), Salmonella Colindale (n?=?15; 6.6 %), Salmonella Elisaberthville (n?=?13; 5.7 %), Salmonella Hillingdon (n?=?13; 5.7 %), and Salmonella Kingston (n?=?13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n?=?26) to 22.8 % (n?=?51). Resistance ciprofloxacin and gentamicin was low (n?=?2; 0.9 %). Multiply resistant isolates included Salmonella Kentucky, the most resistant serovar. qnrB19 was found in two isolates of Salmonella Corvallis and one isolate of Salmonella Larochelle, respectively, while qnrS1 was found in two isolates of Salmonella Derby. Other PMQR genes were not detected. Pigs constitute an important source of diverse Salmonella serovars in Ibadan. The isolates were more resistant to old antimicrobials with some multiple resistant. Control measures and regulation of antimicrobials are warranted.     

Computational Biology and Bioinformatics in Nigeria

Over the past few decades, major advances in the field of molecular biology, coupled with advances in genomic technologies, have led to an explosive growth in the biological data generated by the scientific community. The critical need to process and analyze such a deluge of data and turn it into useful knowledge has caused bioinformatics to gain prominence and importance. Bioinformatics is an interdisciplinary research area that applies techniques, methodologies, and tools in computer and information science to solve biological problems. In Nigeria, bioinformatics has recently played a vital role in the advancement of biological sciences. As a developing country, the importance of bioinformatics is rapidly gaining acceptance, and bioinformatics groups comprised of biologists, computer scientists, and computer engineers are being constituted at Nigerian universities and research institutes. In this article, we present an overview of bioinformatics education and research in Nigeria. We also discuss professional societies and academic and research institutions that play central roles in advancing the discipline in Nigeria. Finally, we propose strategies that can bolster bioinformatics education and support from policy makers in Nigeria, with potential positive implications for other developing countries.     

Antibacterial diterpenoids from Jatropha podagrica Hook

Japodagrin (1) and japodagrone (2), two macrocylic diterpenoids possessing lathyrane and jatrophane skeletons, respectively, have been isolated from the root of Jatropha podagrica Hook. Four other diterpenoids (3-6) were also isolated from this plant. The structures of these compounds were elucidated on the basis of NMR and HRMS analysis, and by spectral comparisons. The compounds displayed antibacterial activity against some gram-positive bacteria.     

Influence of Spirituality and Modesty on Acceptance of Self-Sampling for Cervical Cancer Screening

Introduction

Whereas systematic screening programs have reduced the incidence of cervical cancer in developed countries, the incidence remains high in developing countries. Among several barriers to uptake of cervical cancer screening, the roles of religious and cultural factors such as modesty have been poorly studied. Knowledge about these factors is important because of the potential to overcome them using strategies such as self-collection of cervico-vaginal samples. In this study we evaluate the influence of spirituality and modesty on the acceptance of self-sampling for cervical cancer screening.

Methodology

We enrolled 600 participants in Nigeria between August and October 2014 and collected information on spirituality and modesty using two scales. We used principal component analysis to extract scores for spirituality and modesty and logistic regression models to evaluate the association between spirituality, modesty and preference for self-sampling. All analyses were performed using STATA 12 (Stata Corporation, College Station, Texas, USA).

Results

Some 581 (97%) women had complete data for analysis. Most (69%) were married, 50% were Christian and 44% were from the south western part of Nigeria. Overall, 19% (110/581) of the women preferred self-sampling to being sampled by a health care provider. Adjusting for age and socioeconomic status, spirituality, religious affiliation and geographic location were significantly associated with preference for self-sampling, while modesty was not significantly associated. The multivariable OR (95% CI, p-value) for association with self-sampling were 0.88 (0.78–0.99, 0.03) for spirituality, 1.69 (1.09–2.64, 0.02) for religious affiliation and 0.96 (0.86–1.08, 0.51) for modesty.

Conclusion

Our results show the importance of taking cultural and religious beliefs and practices into consideration in planning health interventions like cervical cancer screening. To succeed, public health interventions and the education to promote it must be related to the target population and its preferences.     

Ase1 domains dynamically slow anaphase spindle elongation and recruit Bim1 to the midzone

How cells regulate microtubule cross-linking activity to control the rate and duration of spindle elongation during anaphase is poorly understood. In this study, we test the hypothesis that PRC1/Ase1 proteins use distinct microtubule-binding domains to control the spindle elongation rate. Using the budding yeast Ase1, we identify unique contributions for the spectrin and carboxy-terminal domains during different phases of spindle elongation. We show that the spectrin domain uses conserved basic residues to promote the recruitment of Ase1 to the midzone before anaphase onset and slow spindle elongation during early anaphase. In contrast, a partial Ase1 carboxy-terminal truncation fails to form a stable midzone in late anaphase, produces higher elongation rates after early anaphase, and exhibits frequent spindle collapses. We find that the carboxy-terminal domain interacts with the plus-end tracking protein EB1/Bim1 and recruits Bim1 to the midzone to maintain midzone length. Overall, our results suggest that the Ase1 domains provide cells with a modular system to tune midzone activity and control elongation rates.     

Phytoremediation potential of Eichornia crassipes in metal-contaminated coastal water

The potential of Eichornia crassipes to serve as a phytoremediation plant in the cleaning up of metals from contaminated coastal areas was evaluated in this study. Ten metals, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, V and Zn were assessed in water and the plant roots and shoots from the coastal area of Ondo State, Nigeria and the values were used to evaluate the enrichment factor (EF) and translocation factor (TF) in the plant. The critical concentrations of the metals were lower than those specified for hyperaccumulators thus classifying the plant as an accumulator but the EF and TF revealed that the plant accumulated toxic metals such as Cr, Cd, Pb and As both at the root and at the shoot in high degree, which indicates that the plant that forms a large biomass on the water surface and is not fed upon by animals can serve as a plant for both phytoextraction and rhizofiltration in phytoremediation technology.