Genetic characterization of cassava (Manihot esculenta Crantz) genotypes using agro-morphological and single nucleotide polymorphism markers

Physiology and Molecular Biology of Plants - Dearth of information on extent of genetic variability in cassava limits the genetic improvement of cassava genotypes in Sierra Leone. The aim of this...     

Industrial-scale manufacturing of pharmaceutical-grade bioactive peptides

Recent studies have shown that most peptide sequences encrypted in food proteins confer bioactive properties after release by enzymatic hydrolysis. Such bioactivities, which include antithrombotic, antihypertensive, immunomodulatory and antioxidant properties, are among the traits that are of biological significance in therapeutic products. Bioactive peptides could therefore serve as potential therapeutic agents. Moreover, research has shown that peptide therapeutics are toxicologically safe, and present less side effects when compared to small molecule drugs. However, the major conventional methods i.e. the synthetic and biotechnological methods used in the production of peptide therapeutics are relatively expensive. The lack of commercially-viable processes for large-scale production of peptide therapeutics has therefore been a major hindrance to the application of peptides as therapeutic aids. This paper therefore discusses the plausibility of manufacturing pharmaceutical-grade bioactive peptides from food proteins; the challenges and some implementable strategies for overcoming those challenges.     

Extraction of oil from microalgae for biodiesel production: A review

The rapid increase of CO(2) concentration in the atmosphere combined with depleted supplies of fossil fuels has led to an increased commercial interest in renewable fuels. Due to their high biomass productivity, rapid lipid accumulation, and ability to survive in saline water, microalgae have been identified as promising feedstocks for industrial-scale production of carbon-neutral biodiesel. This study examines the principles involved in lipid extraction from microalgal cells, a crucial downstream processing step in the production of microalgal biodiesel. We analyze the different technological options currently available for laboratory-scale microalgal lipid extraction, with a primary focus on the prospect of organic solvent and supercritical fluid extraction. The study also provides an assessment of recent breakthroughs in this rapidly developing field and reports on the suitability of microalgal lipid compositions for biodiesel conversion.     

Effects of trypanosome inferction and postpartum liveweight change on resumption of reproduction activity in N'Dama cows

Data on reproduction, liveweight and trypanosome infection of N'Dama cattle raised under traditional husbandry systems in The Gambia were analyzed to quantify the relative effects of postpartum liveweight change and infection with pathogenic trypanosomes on 2 parameters of reproductive efficiency: the ability to calve within 21 months after the initial parturition and the length of the calving interval. Information for the study was obtained from a database on an epidemiological survey begun in 1985 in The Gambia. Calving records (n=294) from 3 locations were classified on the basis of body weight change and prevalence of trypanosome infection between 1 and 4 months postpartum. Least-squares analyses adjusted for effects of location, season of calving, viability of calf, and parity showed that the proportion of cows that calved within 21 months was 50% for cows which maintained or lost less than 5% of the initial postpartum weight and 31% for cows which lost a higher percentage of weight. Corresponding mean calving intervals were 567 and 666 days, respectively (P<0.05). With regard to trypanosome infection, 49% of uninfected cows and 32% of infected cows (P<0.05) calved again within 21 months, with calving intervals of 581 and 651 days, respectively (P<0.05). The interaction between liveweight change and trypanosome infection status was not significant. Furthermore, the findings suggest that while postpartum body weight loss impairs reproductive performance, trypanosome infection does likewise, and these effects may act independently of each other.     

Genetic structure of seventy cocoyam (Xanthosoma sagittifolium, Linn, Schott) accessions in Ghana based on RAPD

Seventy cocoyam accessions collected from the eastern and Volta regions of Ghana were studied using RAPD technique. Ten primers were used to study the genetic diversity and structure of the experimental material and a total of 120 different bands were detected. Levels of polymorphic fragments detected by the ten primers ranged from 69.2% to 100%. In the accessions from the eastern region, the mean observed and effective number of alleles per individual per population and mean Nei's gene diversity were 1.99+/-0.01, 1.53+/-0.12 and 0.312+/-0.05, respectively. Mean observed and effective number of alleles per individual per population and Nei's gene diversity were 1.76+/-0.17, 1.44+/-0.16 and 0.264+/-0.08, respectively for the accessions from the Volta region. Considering the entire collections, the mean observed and effective number of alleles per individual per population and Nei's gene diversity for primers were 1.99+/-0.02, 1.54+/-0.12 and 0.319+/-0.05, respectively. In terms of Nei's F-statistics in the subdivided populations for all primers, the overall gene diversity (Ht) ranged from 0.230 to 0.396 with a mean of 0.313+0.06, within sample gene diversity (Hs) ranged from 0.214 to 0.372 with a mean of 0.286+0.06, gene differentiation (Gst) ranged between 0.005 and 0.178 with a mean of 0.086. Geneflow estimate ranged between 2.309 and 99.500 with a mean of 5.314. The accessions grouped into three main clusters. Accession BD96/183 was the most diverse and may be incorporated into cocoyam breeding programs. The 70 accessions did not cluster into their distinct geographical regions suggesting that there may have been movement of germplasm across the two regions.     

Biophysical analysis of SARS-CoV-2 transmission and theranostic development via N protein computational characterization

Recently, SARS-CoV-2 has been identified as the causative factor of viral infection called COVID-19 that belongs to the zoonotic beta coronavirus family known to cause respiratory disorders or viral pneumonia, followed by an extensive attack on organs that express angiotensin-converting enzyme II (ACE2). Human transmission of this virus occurs via respiratory droplets from symptomatic and asymptomatic patients, which are released into the environment after sneezing or coughing. These droplets are capable of staying in the air as aerosols or surfaces and can be transmitted to persons through inhalation or contact with contaminated surfaces. Thus, there is an urgent need for advanced theranostic solutions to control the spread of COVID-19 infection. The development of such fit-for-purpose technologies hinges on a proper understanding of the transmission, incubation, and structural characteristics of the virus in the external environment and within the host. Hence, this article describes the development of an intrinsic model to describe the incubation characteristics of the virus under varying environmental factors. It also discusses on the evaluation of SARS-CoV-2 structural nucleocapsid protein properties via computational approaches to generate high-affinity binding probes for effective diagnosis and targeted treatment applications by specific targeting of viruses. In addition, this article provides useful insights on the transmission behavior of the virus and creates new opportunities for theranostics development.     

High-resolution satellite remote sensing of littoral vegetation of Lake Sevan (Armenia) as a basis for monitoring and assessment

Physics-based remote sensing in littoral environments for ecological monitoring and assessment is a challenging task that depends on adequate atmospheric conditions during data acquisition, sensor capabilities and correction of signal disturbances associated with water surface and water column. Airborne hyper-spectral scanners offer higher potential than satellite sensors for wetland monitoring and assessment. However, application in remote areas is often limited by national restrictions, time and high costs compared to satellite data. In this study, we tested the potential of the commercial, high-resolution multi-spectral satellite QuickBird for monitoring littoral zones of Lake Sevan (Armenia). We present a classification procedure that uses a physics-based image processing system (MIP) and GIS tools for calculating spatial metrics. We focused on classification of littoral sediment coverage over three consecutive years (2006–2008) to document changes in vegetation structure associated with a rise in water levels. We describe a spectral unmixing algorithm for basic classification and a supervised algorithm for mapping vegetation types. Atmospheric aerosol retrieval, lake-specific parameterisation and validation of classifications were supported by underwater spectral measurements in the respective seasons. Results revealed accurate classification of submersed aquatic vegetation and sediment structures in the littoral zone, documenting spatial vegetation dynamics induced by water level fluctuations and inter-annual variations in phytoplankton blooms. The data prove the cost-effective applicability of satellite remote-sensing approaches for high-resolution mapping in space and time of lake littoral zones playing a major role in lake ecosystem functioning. Such approaches could be used for monitoring wetlands anywhere in the world.     

Tono Reservoir fishery contribution to poverty reduction among fishers in northern Ghana

Fishery characteristics and livelihood status of fishers at Tono Reservoir, Ghana, were investigated between January 2015 and June 2016. Data on fisher demography, fishing gears, fishing methods, perceptions of the state of fish stocks, management practices, income and consumption of fishers were obtained through structured interviews. Censuses of fishers and fishing gears were conducted through direct observation and counts. The population of fishers was 950 and the majority (74%) of the sampled respondents fell within the ages of 24–41 years. Gillnet, cast net, trap and hook and line were the four main gears utilised. Illegal methods of fishing observed included the use of mosquito nets (nets with mesh <1.0 cm) and the use of brewer’s waste (pito mash) as bait. Brycinus nurse, Synodontis spp., Parailia spiniserrata and Chrysichthys spp. were perceived to have disappeared from the reservoir. The fishers were unaware of the existence of any fisheries regulations, hence there was no adherence to management practices. Their daily income was derived mainly from fishing. The incidence of poverty among fishers was low (8%). The Tono Reservoir has a great potential for supporting livelihood if it is properly managed.