In-vitro Antibacterial Activity of Anogeissus leiocarpus Dc (Stem Bark) Extracts against Escherichia coli and Staphylococcus aureus

Antibacterial secreening of ethanolic, aqueous and chloroform extracts of Anogeissus leiocarpus was carried out against Escherichia coli and Staphylococcus aureus. The result shows that all the extract exhibited antibacterial activity against the test organisms with the exception of the lowest concentration of aqueous and chloroform extract. Ethanolic extracts at concentration of 300ug/ml showed greater activity against E. coli (16mm) and Staphylococcus aureus (15mm) than the remaining extracts. Activity was greater against E.coli in response to all fractions (16mm, 15mm, and 12mm respectively at the highest concentrations than the Staphylococcus aureus (14mm, 11mm, and 9mm). Results showed that, antibacterial activity of the extracts was dose - dependant. Augmentin and gentamicine were the antibiotics used as the positive control discs against the test organisms. These antibiotics showed greater activity than the crude extracts respectively. The bioactive compounds detected in the extracts were alkaloids, tannins, flavonoids, glycosides and saponins. As there is growing interest in obtaining sample of plant materials with a view to explore the possibilities for medicinal products and in addition the current global upsurge of bacterial resistance to antibacterial drugs, the plant may be used as promising candidate for drug development.Keywords: Antibacterial, Extracts, Concentration, Bioactivity, Inhibition. Anogeissus leiocarpu

Synthesis, Antibacterial and Antifungal Investigations of Mn (Ii) Complexes with Schiff Bases Derived From 2 – Hydroxy – 1 – Naphthaldehyde and Some Aliphatic Diamines

Schiff base ligands derived from 2-hydroxy-1-naphthaldehyde and some aliphatic diamines were synthesized and characterized. Each of the ligands was used to form complex with Mn (II). Solubility, elemental analyses and IR spectra were carried evaluated. Elemental analyses of the complexes for C, N and H revealed 1:1 metal to ligand ratio. Antibacterial and antifungal activities were determined. Disc diffusion method was employed for these antimicrobial assays against four pathogenic bacteria (Escherichia coli, Salmonella typhi, Proteus sp. and Klebsiella pneumonae) and two fungi (Mucor sp. and Rhizopus sp.). It was found that the ligands and the complexes showed different activities against the isolates. The complexes showed higher activity than the free ligands. Keywords: Schiff base, diamine, ligand, complex, isolates, analysi

The Relevance of Entrepreneurial Orientation to Students Entrepreneurial Intention: Evidence from Federal University Dutse (FUD)

This paper examined the dimensions of entrepreneurial orientation and its relevance to student’s entrepreneurial intention among Federal University Dutse final year students as at 2017­­/2018 academic session. The study adopts cross-sectional research design using quantitative questionnaire approach to collect the data. To validate the model, data from 282 final year students were analysed using the Partial Least Squares Structural Equation Modelling (PLS-SEM). Overall, the study revealed that dimensions of innovativeness, pro-activeness and risk-taking are significantly and positively relevance to student entrepreneurial intention. The study used Human Capital Theory (HCT) as a theoretical foundation of the study. This study served as one of the pioneering study with regard to HCT in testing relationship of this nature. This study recommended that other researchers should use this theory to include other dimension of entrepreneurial orientation for further validation. This study also contributes to the current literatures by extending the used of entrepreneurial orientation which is still rare in student entrepreneurial intention literatures. As suggestion to policy, the government should guarantee not only inspiring students with entrepreneurship education but also inculcate the spirit of innovativeness proactiveness, and risk-taking among  youths as it has relevance in explaining students entrepreneurial intention

Investigating the effect of High Altitude Platform Positioning on Latency and Coverage of 4G Cellular Systems

Wireless communication technologies are rapidly being adopted and developed by countries all over the world as a strategy for sustaining a digital economy. This has proven very useful for economic recovery from the crises brought about by the COVID-19 pandemic of the year 2020. The latency and coverage area of a wireless network are two major areas that are always seeking improvement. The High Altitude Platform communication technology can provide improvement in speed and coverage area for 4G cellular systems. This work investigated the effect of positioning High Altitude Platforms on the latency and coverage of 4G cellular Systems. A quantitative approach was used in the methodology of this paper. A HAP model showing a single platform flying in a circular trajectory over Base Transceiver Stations BTSs and serving as a relay mobile station was presented. A detailed simulation algorithm for the HAP and results for the simulation were given. Results showed that using the HAP as a relay mobile station in a network can give a latency reduction of up to 58.9%.  Also, the altitude of the HAP directly affects the angle of reception which was found to improve the coverage

Characterization of Schiff base derived from 2-hydroxo-1-naphthaldehyde and Ethylenediammine and its Copper (II) Complex by Potentiometric and Spectrophotometric Methods

Synthesis of Copper (II) complex with a Schiff base derived from the reaction of 2 – hydroxyl-1- naphthaldehyde and ethylenediammine was carried out. Solubility, melting/decomposition temperature, molar conductance, potentiometric, elemental analysis as well as uv-visible spectrophotometric studies were carried out. The pKa of the Schiff base was determined potentiometrically and checked using ORIGIN 50 method. Potentiometric studies revealed 1:1 metal to ligand ratio. Job’s method of continuous variation also revealed 1:1 metal to ligand ratio. Molar conductance measurements showed that the complex is non electrolyte with very high stability constant value. Gibb’s free energy determination showed that the complex is very stable as shown in the high decomposition temperature measurements.Keywords: Potentiometry, Schiff base, Spectrophotometry, Stability constan

Modelling seagrass blue carbon stock in seagrass-mangrove habitats using remote sensing approach

Modelling seagrass blue carbon stocks are essential to complement the satellitebased remote sensing in detecting the underground seagrass carbon stocks. The green carbon initiatives have for long reported the detailed mapping and estimation procedural as well as the audit protocol of the global terrestrial carbon stocks. Research on the blue carbon mapping and its related modelling and estimation, on the other hand, is rarely if ever published as part of its importance is realised but remained scattered. Therefore, this study aimed at investigating blue carbon stocks in seagrass habitats by estimating the total carbon stored in seagrass using the satellite-based technique. The specific objectives are to : 1) assess and adapt some selected models for deriving seagrass total above-ground carbon (STAGC); 2) formulate new approach based-on selected models to combine with in-situ data, to model and estimate blue carbon stocks from seagrass total below-ground carbon (STBGC); 3) develop a novel technique using the selected models with soil organic carbon (SOC) to model and estimate the blue carbon stocks from seagrass total soil organic carbon (STSOC); and 4) integrate all the models (STAGC, STBGC, and STSOC) to produce a framework for the mapping and estimation of seagrass total blue carbon stock (STBCS). Suitable logistic functions were selected and applied on the satellite images to investigate seagrass, and soil carbon stocks along the seagrass meadows of Peninsular Malaysia (PM) coastline All the Landsat ETM+’s shortwave visible bands (blue, green, red) were employed for detecting and mapping seagrass stocks boundary within the coastline of PM. The derivation of STAGC was adopted from the existing bottom reflectance index (BRI) based technique via establishing a strong relationship between BRI with seagrass total aboveground biomass (STAGB). While for STBGC estimation, the STAGB^ (STAGB obtained from BRI image) were correlated with seagrass total below-ground biomass derived from insitu measurement (STBGB^^ro). Both these STAGB^ and STBGB^.^ro were converted into STAGC and STBGC using a conversion factor. Furthermore, the derivation of seagrass total soil organic carbon derived via laboratory test (STSOCi^b) was achieved through correlating BRI values with corresponding in-situ samples of soil organic carbon (SOC) obtained from the laboratory analysis by the Carbon-Hydrogen Nitrogen Sulphur (CHNS) analyser. These models were generated from the three major sample areas (Johor, Penang, and Terengganu), which were used to estimate the entire seagrass carbon stocks in the coastline of PM. The models revealed a robust correlation results for BRI versus STAGB (R2 = 0.962, p< 0.001), STAGB^, versus STBGB/A,wro (R2 = 0.933, p< 0.001,), and BRI and STSOC (R2 = 0 .989, p< 0.001) respectively. The STBCS for the whole seagrass meadows along the coastline of PM was finally realised, demonstrating a good agreement in accuracy assessment (Root Mean Square Error (RMSE) = +- <1MtC/ha\). It is, therefore, concluded that the new approach introduced by this research on STBGC and STSOC estimation was tested and proved significant on the entire STBCS quantification for the PM coastline. The contributions are critical to fast-track the United Nations Framework Convention on Climate Change (UNFCCC) agreement to report the STBCS contents. Hence, this study has managed to propose a new fundamental initiative for estimating STBCS for speedy realisation of 2020 agenda on targets 14.2 and 14.5 of United Nations’ Sustainable Development Goal 14th (life below the water)

Plant gum exudates (Karau) and mucilages, their biological sources, properties, uses and potential applications: A review

This paper or review discusses the natural plant exudates and mucilages, their sources, properties and uses and the potential applications. Research in natural polymeric materials has witness growing interest and attention. This is attributable to a number of factors which include their relative abundance, low cost,  biodegradable nontoxic, and ecofriendly profile.They are polymers that are mostly plant in origin with a vast applications.Polysaccharides hydrocolloids including gum and mucilage are abundant in nature and commonly found in many higher plants. These polysaccharides constitute a structurally diverse class of biological  macromolecules with a broad range of physicochemical properties which are widely used for various applications in pharmacy, medicine, food and other non- food applications. In recent years those polymers derived from plants have evoke tremendous interest because of their industrial applications as diluent binders, thickening agents, smoothening, emulsifiers, gelling agents and stabilizers. This increasing research in this group of these plant materials are clear indications of their increasing importance.The fact for increase in importance of natural plant based materials is that plant resources are renewable and if cultivated or harvested in a sustainable manner, they can provide a constant supply of raw materials. To that effect, more understanding of their nature, physicochemical properties, sources, uses be gained so that can be used for wider applications.Key words:, Polymer,GumExudate, Mucilage, Biological sources, Potential applicatio

Synthesis and Physicochemical Properties of Copper (II) Complex with a Schiff base Derived from 2 – Hydroxy – 1 – naphthaldehyde and Ethylenediammine

Synthesis of Copper (II) complex with a Schiff base derived from the condensation of 2 – hydroxyl-1-naphthaldehyde and ethylenediammine was carried out. Solubility, melting/decomposition temperature, molar conductance, potentiometric as well as uv-visible spectrophotometric studies were carried out. The pKa of the Schiff base was determined potentiometrically and checked using ORIGIN 50 method. Potentiometric studies revealed 1:1 metal to ligand ratio. Job’s method of continuous variation also revealed 1:1 metal to ligand ratio. Molar conductance measurements showed that the complex is non electrolyte with very high stability constant value. Gibb’s free energy determination showed that the complex is very stable as shown by the high decomposition temperature measurements.Keywords: Complex, Potentiometry, Schiff base, Stability constan

The consequences of qualitative overstretch on employee intention to quit in Malaysia call center industry: An implication of customer relationship management

The purpose of this study is to determine the consequences of customer relationship management (CRM) application on qualitative overstretch and intention to quit in Malaysia call center industry.A conceptual model was developed to explain the hypothesis direction and the evidence from ample of literatures suggested that comprehensive applications of CRM strategy should be adopted and integrated into organizations’ operations in order to achieve organizational performance and resolve the issue of employee turnover.More so, appropriate training program that can reduce qualitative overstretch and eradicate stress should be provided for the employees of call centers

Channel Propagation Characteristics on the Performance of 4G Cellular Systems from High Altitude Platforms (HAPs)

In this paper, we investigated the effect of different channel propagation characteristics on the performance of 4G systems from high altitude platforms (HAPs). The use of High-Altitude Platforms for communication purpose in the past focused mostly on the assumption that the platform is quasi stationary. The technical limitation of the assumption was that of ensuring stability in the positioning of the platform in space. The use of antenna steering and other approaches were proposed as a solution to the said problem. In this paper, we proposed a channel model which account for the motion of the platform. This was done by investigating the effect of Doppler shift on the carrier frequency as the signals propagate between the transmitter and receiver while the High-Altitude Platform is in motion. The basic free space model was used and subjected to the frequency variation caused by the continuous random shift due to the motion of the HAPs. The trajectory path greatly affects the system performance. A trajectory of 30km, 100km and 500km radii were simulated. An acute elevation angle was used in the simulation. The proposed model was also compared to two other channel models to illustrate its performance. The results show that the proposed model behave similar to the existing models except at base station ID 35 and 45 where the highest deviation of 20dBm was observed. Other stations that deviated were less than 2dBm