International Annals of Science
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Symptom Severity of Nicotiana benthamiana Plants Inoculated with Agrobacterium Containing Infectious DNA-A Clones of Honeysuckle Yellow Vein Virus (HYVV)
Get PDFTo investigate the pathogenicity and virulence of the Honeysuckle yellow vein virus (HYVV) lacking betasatellites, PCR amplified unit-lengths of DNA-A genome of HYVV-[DJ] were cloned into binary vector pRI101-AN, and generated HYVV-[DJ]-1mer, -1.3mer and -2mer genomes. Each construct was transformed into Agrobacterium cells and agro-inoculated into young leaves of Nicotiana benthamiana. Except for the HYVV-[DJ]-1mer, HYVV-[DJ]-1.3mer and -2mer clones caused pronounced disease symptoms in N. benthamiana. HYVV-[DJ]-2mer agro-inoculated plants showed more severe plant stunting with downward leaf curling and crinkling than those of HYVV-[DJ]-1.3mer agro-inoculated plants. To discriminate the clone’s virulence quantitatively, SYBR Green-based real-time PCR was performed for the quantification of the target virulence gene DNA in agro-inoculated plants that were collected at weekly intervals for 4 weeks. Regression analysis was obtained from the standard curves by plotting Ct values over the logarithm of the amount of V1 protein gene DNA present in a dilution series of plasmid containing the full-length HYVV-[DJ] genome. Equation of the HYVV V1 DNA standard curve was used to quantify V1 gene DNA concentration in agro-inoculated plants with each clone. The accumulation of V1 gene DNA in HYVV-[DJ]-1.3mer agro-inoculated plants reached the peak level at 4 weeks post inoculation, while the accumulation of V1 gene DNA in HYVV-[DJ]-2mer agro-inoculated plants reached the peak level at 3 weeks post inoculation. The amount of V1 DNA in HYVV-[DJ]-1.3mer agro-inoculated plants was significantly more than that in HYVV-[DJ]-2mer agro-inoculated plants. Considering the results, there was a difference between the accumulation of virus DNA and the symptom severity of the analyzed plants agro-inoculated with each clone. It suggested that the infectious clones’ virulence is not necessarily correlated with the symptom severity
Phytochemical Screening and Antioxidant Potential of Selected Nigerian Vegetables
Get PDFReducing power activities of ten vegetables commonly consumed in Katsina State, Nigeria have been assessed with the view of establishing their antioxidant capacities. Preliminary, the phytochemicals of the individual plants were screened, and it was found that various constituents were present. In particular, flavonoids and anthraquinones were found in Ficus glumosa which also appeared to demonstrate the best reducing power activity (4.898 at 25 mg/L)
Steganographic Techniques Classification According to Image Format
Get PDFIn this work, we present a classification of steganographic methods applicable to digital images. We also propose a classification of steganographic methods according to the type of image used. We noticed there are no methods that can be applied to all image formats. Each type of image has its characteristics and each steganographic method operates on a precise colorimetric representation. This classification provides an overview of the techniques used for the steganography of digital image
Isolation and Activity Determination of Enzyme Phosphatase Secreted by Aspergillus niger
Get PDFThe use of enzymes on industrial scale saves a lot of energy and avoids pollution, thus holding a promise for green and economically sustainable alternative strategies in industrial transformations. Generally, the fungi Aspergillus niger secretes enzymes which can be used in different industries. Thus, coming up with these enzymes in large amounts will definitely result in reduced costs encountered in importing them for industrial use. This study focussed on isolation and activity determination of an enzyme phosphatase secreted by Aspergillus niger. This enzyme can be of great importance in molecular biology industries, particularly for recombinant DNA technology. For this study, pure cultures of Aspergillus niger were used. Aspergillus niger was resuscitated on potato dextrose agar and then subcultured in Adam’s medium, a medium specific for the production of phosphatase. Cells were centrifuged and the filtrate was collected whilst the residue was discarded. The filtrate was expected to contain the crude enzyme phosphatase since Aspergillus niger secretes the extracellular enzyme into the medium. Disodium phenyl phosphate was used as a substrate for the determination of the phosphatase activity. The enzyme activity was determined spectrophotometrically by reading absorbance of phenol formed in the presence of enzyme and the substrate. The concentration of phenol liberated was then used to calculate the enzyme activity expressed in King Armstrong Units (KAU). Further work on enzyme activity determination was done by varying enzyme and substrate concentrations. Results showed that the isolated alkaline phosphatase had activity of 4.0 KAU and 4.5 KAU at 25 ºC and 37 ºC respectively. Acidic phosphatase had activity of 5 KAU and 7 KAU at 25 ºC and 37 ºC respectively. Rate of activity increased upon increasing enzyme concentration and substrate. Thus, Aspergillus niger produces the enzyme phosphatase, however, there is need to induce the production of these enzymes for industrial use
Outdoor Air Quality and Antibiogram Characteristics of Bacterial Isolates of Akure City Abattoirs, Nigeria
Get PDFAir sampling of Onyearugbulem and FUTA abattoirs was carried out to evaluate their quality. Air sampling was done using the open-settling method on general and selective agar media of the gutter, sleeping bench, slaughtering floor dumpsite, slaughtering table and roof of the abattoirs. Using standard methods, Presumptive identification of the bacterial isolates was carried out. An array of ten (10) conventional antibiotics was used to assay the antibiotic susceptibility characteristics of the bacterial isolates. Multiple antibiotic sensitivity index (MARI) was determined for isolated bacteria. At Onyearugbulem abattoir, the total Escherichia coli count ranged from 3.6×10 cfu/ml from the gutter and slaughtering table to 6.5×10 cfu/ml from the slaughtering floor, while the total bacterial count ranged from 1.34×102 cfu/ml from dumpsite to 2.55×102 cfu/ml from the gutter, the total coliform count ranged from 2.8× 10 cfu/ml from slaughtering floor to 4.1×10 cfu/ml from sleeping bench. Several bacteria were presumptively isolated. These include: Micrococcus sp., Bacillus sp., Staphylococcus aureus, Escherichia coli, Proteus sp., Enterobacter aerogenes and Aeromonas sp. Ciprofloxacin (10 µg) had an inhibitory effect on all the Gram positive bacterial isolates with the highest inhibitory activity on S. aureus at 24.00 mm, and the Gram negative bacteria with the highest inhibitory activity on E. coli at 21.00 mm. Micrococcus sp. had the highest MARI of 0.8. These findings reveal the presence of multiple-antibiotic resistant bacteria in Onyearugbulem and FUTA abattoirs’ atmosphere. There is therefore need for routine environmental sanitation of the slaughterhouses
The 14-3-3 (YWHA) Proteins in Signalling and Development of the Fruit Fly, Drosophila melanogaster
Get PDFThe 14-3-3 (YWHA or Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation proteins) are a family of highly conserved, homologous proteins critical to diverse cellular events including cell cycle, signal transduction and embryonic development. Various species-specific isoforms of 14-3-3 exist, encoded by separate genes. They are expressed in a wide variety of organisms ranging from plants to animals, including the fruit fly or Drosophila melanogaster. Drosophila is one of the most universally accepted model systems to study complex cellular mechanisms of signalling and development. However, regulation of these processes in fruit flies by the 14-3-3 proteins have not been entirely understood. This mini review encapsulates the expression, distribution, interactions and regulatory roles of the 14-3-3 proteins in Drosophila. The analysis would help to elucidate some of the molecular bases of key cell-signalling mechanisms and development
Factors Influencing Midwifery Clinical Decision-making
Get PDFClinical decision-making is an important element in midwifery practice. Midwives are required to have a sound knowledge to manage complications during childbirth. Any misjudgement by a midwife may lead to adverse birth outcomes. The aim of this paper is to review factors that contribute to clinical decision-making of midwives. This was achieved by reviewing published research articles. Studies have shown that shortage of human and material resources, poor skill mix, absence of mentors and lack of autonomy are some of the contributing factors that may affect midwives’ decision-making
Toxicological Safety Assessment of Molluscicides Against Non-target Aquatic Biota; Colisa fasciatus
Get PDFPlants Terminalia arjuna and Tamarindus indica are known to have a significant molluscicidal potential to control the population of vector snails. Since the molluscicides are considered an emerging pollutant and are frequently detected in surface water bodies and found to be a great threat for aquatic biota. Hence, the main objective of this research is to critically evaluate the ectotoxicological and chronic effect of plant-derived molluscicides on other aquatic biotas. With these references this study deals with the safety measurement of molluscicides arjnolic acid, saponin and procynadine from T. arjuna and T. Indica against the fish Colisa fasciatus which share the same habitat with snails. The result of toxicity experiment reveals that fishes showed no mortality against 24h LC90 (against L. acuminata and I. exustus) up to 96h exposure duration. The enzyme bioassays of these molluscicides on the nervous tissue of fish showed no significant effect on key enzymes Acetylcholinesterase, acid and alkaline phosphates activity in comparison to control group of fishes. These results indicated that the application of arjunolic acid, saponin, and procynadine derive from plant T. arjuna and T. indica at its maximum concentration (24h LC90 of L. acuminata and I. exustus) and exposure duration (96h) did not cause any mortality or treatment-related enzymes inactivity in fishes. The study conclusively proved the ecotoxicological and chronic safety of plant-derived molluscicides arjunolic acid, saponin, and procynadine on non-target animals in the aquatic environment
Antibacterial Activity of Melia azedarach Leaves against Salmonella typhi and Streptococcus pneumoniae
Get PDFAntimicrobial drug resistance is increasingly becoming an important global problem. Among the major causes for concern is drug resistant Streptococcus pneumoniae and Salmonella typhi, which have become resistant to at least one antibiotic. This challenge has lead scientists to investigate plants as potential sources of antimicrobial agents since they have been used to treat diseases long before the discovery of antibiotics. In Zimbabwe, typhoid is a leading cause of mortality and morbidity due to poor sanitation and poor treatment regimes. Traditionalists are using Melia azedarach leaves for the treatment of diarrhea, a typhoid symptom. Thus, this study focused on validating the use of M. azedarach leaves for medicinal purposes by determining their antibacterial activity against S. pneumoniae and S.typhi, the causative agent of typhoid fever. Melia azedarach leaf constituents were extracted using ethanol, ethylacetate, hexane, dichloromethane and methanol. Their antibacterial activities were assessed using the agar disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Haemolysis assay was carried out to determine the toxicity of the potent extracts. The ethanol and hexane extracts showed antibacterial activity against S. typhi whilst dichloromethane and hexane extracts showed antibacterial activity against S. pneumoniae. Minimum inhibitory concentrations for ethanol and hexane against S. typhi were < 1 µg/ml and 15.6 µg/ml respectively, whilst their minimum bactericidal concentrations were 31.25 µg/ml and 250 µg/ml. The MICs for dichloromethane and hexane extracts against S. pneumoniae were 31.25 µg/ml and 62.5 µg/ml respectively, whilst their MBCs were 31.25 µg/ml and 125 µg/ml. The extracts ethanol, hexane and dichloromethane had haemolytic activity of 63 %, 62 % and 59 % respectively. Therefore, these results validate the use of M. azedarach leaves for medicinal purposes. However, these leaves may be toxic to human consumption, thus there is need for further investigation on their toxicity in vivo
Heavy Metal Resistance by Endophytic Bacteria Isolated from Guava (Psidium Guajava) and Mango (Mangifera Indica) Leaves
Get PDFHeavy metal resistant bacteria are widespread in nature and their application in decontamination of polluted ecosystems is promising. In this study, ability of endophytic bacteria isolated from Psidium guajava (Guava) and Mangifera indica (Mango) for heavy metal resistance was assessed. Leaves samples form the two plants were collected and processed according to the standard laboratory practices. Heavy metals were analyzed using Atomic absorption spectrophotometer. Endophytic bacteria were isolated and identified using morphological and biochemical characteristics; heavy metal resistance was determined by plate dilution method. Heavy metal analysis revealed that the leaves samples contained considerable quantities of Manganese (Mn), Lead (Pb) and Cadmium (Cd) ranging from 1.21±1.6 mg/Kg (for Cd in Guava leaves) to 116.58±1.3 mg/Kg (for Mn in Mango leaves). A total of six bacterial species were isolated from both of the plants leaves (3 each). Guava endophytes were identified as Streptococcus sp, Staphylococcus albus and Staphylococcus seiuri whereas Staphylococcus aureus, Staphylococcus xylulose and Staphylococcus intermedius were from Mango leaves. The identified isolates were tested for ability to resist heavy metals in-vitro and were capable of showing different patterns of resistance to MnCl2, PbCl2 and CdCl2. All the endophytes were highly resistant to PbCl2 followed by MnCl2 but susceptible to CdCl2. The ability of plants and bacterial endophytes understudy to tolerate or resist heavy metals is a good indication of their phytoremediation potentials and thus, should be harnessed