Biosynthesis, characterization and antimicrobial study of silver nanoparticles (agNPs)

In this paper, biological synthesis of silver nanoparticles (AgNPs) using Syzygium guineenses stem extract with 1mM, 2mM and 3mM AgNO3 concentrations has been presented. The plant extract was prepared with distilled water. The characterization and morphological composition of the synthesized AgNPs were determined by UV-visible spectroscopy and SEM respectively, while FTIR analysis was performed to identify the presence of the possible functional groups in the synthesized nano particles. It was observed from the UV and SEM analyses that the particles formed have diameters in the range of 23.5nm - 89.3nm, which is the range of nanoparticle size. Antibacterial test was carried out on the sample with six pathogenic microbes (Methicillin Resistant Staphylococus aureas, Vancomycin Resistant Entrococci, Staphylococcus aureas, Bacillus sublitis, Escherichia coli, and Pseudomonas aeruginosa) to ascertain the antimicrobial activity of the synthesized AgNPs. Both the characterization and antimicrobial activity test were very successful and could lead to significant economic viability, as well as being environmentally friendly for treatment of some infectious diseases.Keywords: Syzygium guineenses, Green Chemistry, Spectroscopy, Optoelectronics, Biomedical Sensor

Dynamic relationship of exchange rates and crude oil prices in South Africa: Are there asymmetries?

We estimated the relationship between the exchange rates and crude oil prices for the period of 1960 to 2013. Based on Engle-Granger we found that the variables are cointegrated means there exist long-run relationship. However, when we move on to TAR and MTAR models the findings are opposite as there is no element of cointegration and the speed of adjustment is symmetric. This shows that based on TAR and MTAR models the effects of exchange rates on crude oil prices is insignificant. The policy relevance is that South African authority need to monitor its exchange rates persistently related to other currencies more especially American dollar because it determined the crude oil prices that might have greater influences on other macroeconomic variables. Keywords: Exchange rates, Oil prices, Asymmetry, South Africa, Error correction model

Dynamic relationship of exchange rates and crude oil prices in South Africa: are there asymmetries?

We estimated the relationship between the exchange rates and crude oil prices for the period of 1960 to 2013. Based on Engle-Granger we found that the variables are cointegrated means there exist long-run relationship. However, when we move on to TAR and MTAR models the findings are opposite as there is no element of cointegration and the speed of adjustment is symmetric. This shows that based on TAR and MTAR models the effects of exchange rates on crude oil prices is insignificant. The policy relevance is that South African authority need to monitor its exchange rates persistently related to other currencies more especially American dollar because it determined the crude oil prices that might have greater influences on other macroeconomic variables

Adherence to Protective Measures against Hearing‑Related Hazards of Mobile Phone Users among University Students

Background: Mobile phone is an integral part of the society used by almost all. Youth in Nigerians are recognized as the most active users of mobile phones. There are about 1.1 billion youth people globally at risk of noise‑induced hearing loss from unsafe listening. The awareness and adherence to hearing conservation measures against the hearing‑related hazards of mobile phones have not been evaluated in our environment. Aims: To determine the knowledge and adherence to protective measures against the hearing‑related hazards of mobile phones among university students. Materials and Methods: The study was a cross‑sectional descriptive type, conducted among university students. Ethical clearance was obtained from the institutional review committee, a multistage random sampling technique was used to recruit the participants, and a specially designed and validated questionnaire was used to collect the data. The data were analyzed using Statistical Product and Service Solutions (SPSS) version 20.0. Results: The age of the respondents ranged from 16 to 40 years with a mean age of 23.6 ± 5.3 years. Very few of the participants (19.1%) adhere to protective measures to mitigate hearing‑related hazards of mobile phones, although about half (52.1%) had good knowledge of hearing  conservation measures. There was a statistically significant association between knowledge of hearing‑related hazard of mobile phone (P = 0.038) and knowledge of protective measures (P = 0.000) with the adherence to protective measures, respectively. Conclusions: The knowledge and  adherence to protective measures against the hearing‑related hazards of mobile phones were poor among the respondents. Keywords: Hearing loss, mobile phone, protective measures, university student

Asymmetric co-integration analysis of exchange rates and crude oil prices: evidence from India

Using monthly data from January, 1980 to July 2013, the aim of the article is to find out whether there is cointegrating relationship between exchange rates and crude oil prices in India. The result indicates that there exists cointegration between the variables and speed of adjustment shows symmetric based on TAR model, while MTAR model exhibit asymmetric adjustment. The findings indicated that exchange rates have significant influence on crude oil prices in India and the adjustment to equilibrium when variables deviated is non-linear. The implication is that Indian policy makers should focus more on their exchange rates dynamics in line with the persistent rises of crude oil prices that affects other macroeconomic variables specifically exchange rates that have significant influence on international trade considering the relevance of India in the international export market

PEO-hBN-NaClO4 Polymer Composite Electrolyte for Sodium Ion Batteries

A new polymer electrolyte (conducting sodium-ion) based on Polyethylene oxide (PEO) matrix comprising NaClO4 and nano sized hexagonal boron nitride was fabricated via the technique of solution casting for use in sodium ion batteries. Interaction of PEO with Na-ion was investigated with fourier transform infrared (FT-IR) which reveals the extend of Na-ion solvation by PEO (EO:Na). The crystallinity of the polymer electrolyte was investigated with X-ray diffraction (XRD) and thermal properties of the composites were studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results show that the melting temperature (Tm) of PEO decreases addition of both NaClO4 and hBN. TGA results showed that all the composites membranes were thermally stable till 300 oC. Surface morphology of the composite was examined using scanning electron microscopy (SEM) which also reveals the homogeneous dispersion of nano hBN in the polymer matrix. Ionic conductivity of the polymer composite was studied with impedance spectroscopy and PEO5hBN10Na sample showed maximum ion conductivity of approximately 1.4 × 10-3 S/cm at 100 oC

Kinetic and Isotherm Studies of Methyl Violet Adsorption onto Carbonized Waterlily (Nymphaea lotus) Leaves Powder

In this study, the adsorption of methyl violet from an aqueous solution using carbonised water lily (CWL) leaves powder as a low-cost, efficient and eco-friendly adsorbent was investigated using a batch system under controlled conditions. The adsorbent's moisture, organic matter, ash, bulk density, pore volume, and pH were determined. The adsorbents were characterised by scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) techniques which confirm the adsorption of the methyl violet onto the CWL adsorbents. The effect of adsorption parameters such as contact time, dosage, initial concentration, pH and temperature were studied for optimisation. It was confirmed that contact time, dosage, concentration, pH and temperature positively affected the adsorption process. The kinetic data were best described by pseudo-second order under all experimental temperatures. The adsorption isotherms were estimated and established to fit nicely into the D-R model compared to other models generated and tested. Thermodynamic studies of the sorption process indicate that the process was feasible, spontaneous, and exothermic and decrease in the randomness of the adsorption process during the transfer of molecules between the adsorbent and adsorbates with entropy (∆S) of 23.77 J/mol.K. due to negative values of Gibb’s free energy observed. This study confirmed that CWL could be employed as a low-cost, eco-friendly adsorbent for removing toxic dyes such as methyl violet from an aqueous solution

Sonographic features of radiologically non-functioning kidneys on intravenous urography (IVU) in Kano Metropolis, Nigeria

Background: Despite technological advancement in uro-radiology, renal ultrasonography remains the imaging modality of choice for evaluating various pathological conditions affecting urinary tract (GIT) system.Aim: This study was aimed at evaluating sonographic features of radiologically nonfunctional kidneys in Kano metropolis, Nigeria.Methods: A prospective study involving 94 each of disease and control group were conducted in Kano metropolis from January 2019 to January 2021. Renal scans were performed using a digital ultrasound imaging system; model DP-8800Plus fitted with a 3.5MHz curvilinear transducer. The maximum length, width, and thickness were measured. The renal echogenicity was assessed and graded. Data was analyzed using SPSS Version 22.0Results: The mean values of the right and left renal volumes among adult patients was 400.5 ± 527.3 cm3 and 177.6 ± 174.3 cm3 respectively. For pediatric patients it was 272.3 ± 308.6 cm3 and 241.6 ± 228.7 cm3 for the right and left kidney respectively. The renal parenchymal echogenicity of the right kidney among adult patients were sored as grade II 2 (5.3%), grade III 27 (71%), and grade IV 9 (23.7%), while that pediatric patients were Grade 0 (11.1%), and 8 (88.9%) as grade III. The adults left kidney were scored grade II 2 (6%), and 16 (47%) each as grades III and IV, while the pediatric group scored 3 (25%) as grade II, and 9 (75%) as grade III.Conclusion: Increased renal volume, shrunken kidney, increased renal parenchymal echogenicity, and severe hydronephrosis were strong sonographic indicators of nonfunctional kidneys

Growth Performance and Carcass Merit of Japanese Quails (Coturnix japonica) Fed with Sorghum as an Energy Source Substitute for Maize in North Western Nigeria

A feeding trial was conducted to determine the growth performance and carcass characteristics of Japanese quails fed diets containing sorghum. A total of ninety of one-week old Japanese quail chicks were used for the experiment. Five diets were formulated in which sorghum was included at graded levels 0, 15, 30, 45 and 60% dietary levels designated as treatment 1, 2, 3, 4 and 5 respectively. The experimental period was five weeks when the birds reach six weeks of age.  The results of the growth performance showed significant differences (P<0.05) in the final body weight (161.70 – 180.10 g) and daily feed intake (21.34–25.12 g). Significant (P<0.05) differences was also observed in all carcass parameters measured except for dressing percentage. Liver weight and large intestine with T5 (65% total replacement) recorded the highest means value of 6.00 g and 6.66 g. Non-significant high values of feed conversion ratio were also obtained among the treatments. Treatment 1 (0%) and Treatment 5 (60%) showed better results in all parameters measured compared to other treatments. In conclusions, sorghum grain can play a significant role in formulating quail feed and can completely (60%) be used to replace maize without affecting the performance and carcass yield of the quails

Properties of Foodborne Pathogens and Their Diseases

Thousands of foodborne pathogens are causing a great number of diseases with significant effects on human health and economy. Foodborne pathogens can contaminate food items not only during production and processing, but also at the time of storage and transport before consuming. During their growth, these microorganisms are capable of secreting different type of toxins into the extracellular environment. Likewise, other harmful substances can be also released and can contaminate food after breakup of food pathogens. Many microbial toxins can withstand inactivation, and can endure harsh treatment during food processing. Many of these molecules are partaken in cellular processes and can display different mechanisms of pathogenesis of foodborne organisms. Thus studying the properties of foodborne pathogens can help in the understanding of their contamination and inactivation. In the present review, we discussed extensively on the properties of foodborne pathogens including bacteria, viruses and parasites. In addition, some of the diseases caused by foodborne pathogens and the mechanism of their pathogenesis were also discussed