The 50 most-cited articles in Heliyon, 2018

This is a survey of neural network applications in the real-world scenario. It provides a taxonomy of artificial neural networks (ANNs) and furnish the reader with knowledge of current and emerging trends in ANN applications research and area of focus for researchers. Additionally, the study presents ANN application challenges, contributions, compare performances and critiques methods. The study covers many applications of ANN techniques in various disciplines which include computing, science, engineering, medicine, environmental, agriculture, mining, technology, climate, business, arts, and nanotechnology, etc. The study assesses ANN contributions, compare performances and critiques methods. The study found that neural-network models such as feedforward and feedback propagation artificial neural networks are performing better in its application to human problems. Therefore, we proposed feedforward and feedback propagation ANN models for research focus based on data analysis factors like accuracy, processing speed, latency, fault tolerance, volume, scalability, convergence, and…

In living organisms, biofilms are defined as complex communities of bacteria residing within an exopolysaccharide matrix that adheres to a surface. In the clinic, they are typically the cause of chronic, nosocomial, and medical device-related infections. Due to the antibiotic-resistant nature of biofilms, the use of antibiotics alone is ineffective for treating biofilm-related infections. In this review, we present a brief overview of concepts of bacterial biofilm formation, and current state-of-the-art therapeutic approaches for preventing and treating biofilms. Also, we have reviewed the prevalence of such infections on medical devices and discussed the future challenges that need to be overcome in order to successfully treat biofilms using the novel technologies being developed.

Different concentrations of Dy 3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x) B 2 O 3 - 25 SiO 2 -10 Al 2 O 3 -30 LiF - 5 ZnO - x Dy 2 O 3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol%) were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f) were used to determine the Judd-Ofelt (J-O) intensity parameters Ω λ (λ = 2, 4 and 6). The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (A R ), total transition probability rate (A T ), radiative lifetime (τ R ) and branching ratios (β R ) for the excited 4 F 9/2 level of Dy 3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram.

The realization of the scale, magnitude, and complexity of the water and sanitation problem at the global level has compelled international agencies and national governments to increase their resolve to face the challenge. There is extensive evidence on the independent effects of urbanicity (rural-urban environment) and wealth status on access to water and sanitation services in sub-Saharan Africa. However, our understanding of the joint effect of urbanicity and wealth on access to water and sanitation services across spatio-temporal scales is nascent. In this study, a pooled regression analysis of the compositional and contextual factors that systematically vary with access to water and sanitation services over a 25-year time period in fifteen countries across sub-Saharan Africa (SSA) was carried out. On the whole, substantial improvements have been made in providing access to improved water sources in SSA from 1990 to 2015 unlike access to sanitation facilities over the same period. Households were 28.2 percent and 125.2 percent more likely to have access to improved water sources…

A cost-effective method for the biosynthesis of copper nanoparticles (Cu-NPLs) using Tilia extract under optimum conditions has been presented. The use of Tilia extracts for the synthesis of Cu-NPLs has been investigated for the first time. The Cu-NPLs are stable due to in situ bio-capping by the Tilia extract residues. Formation of metallic Cu was revealed by UV-vis and XRD analyses. UV-vis of Cu-NPLs showed an SPR characteristic peak at 563 nm (energy bandgap=2.1 eV). Morphology and size of the as-prepared Cu-NPLs were determined using SEM and TEM studies. TEM observations show that the produced Cu-NPLs are hemispherical in shape with different diameters in the range 4.7–17.4 nm. The electrical conductivity of the Cu-NPLs was determined as 1.04 × 10 −6 S cm -1 (at T=120 K). The antimicrobial studies exhibited relatively high activity against pathogenic bacteria like Gram-positive & Gram-negative bacteria. Anticancer studies demonstrated the in vitro cytotoxicity value of Cu-NPLs against tested human colon cancer Caco-2 cells, human hepatic cancer HepG2 cells and human breast…

Most prior studies into the utilization of internet technology for learning purposes in contemporary educational settings in developing countries has largely dealt with its impact on academic performance, communication and general educational purposes. This paper investigates the place of the internet in academic research and learning of students, through both quantitative and qualitative research approaches, using 250 undergraduate students in three selected universities within North-Eastern Nigeria. To gain an in-depth understanding of the perception of the students' views, a focus group was conducted with 18 students. The students perceived that the lack of digital readiness among their staff and institution, the absence of electronic library for easy accessibility to journals from the scientific database, and inefficient cybercafé and internet facility within their university settings were the main issues discouraging the utilization of the internet within their institutions. Yet, they still strive to find ways through self-organization, resilience and resourcefulness to make…

In this study, the three structures of the symmetric paper supercapacitors based on the carbon nanotubes (CNTs), graphite nanoparticles (GNPs) and graphene electrodes have been fabricated. In the supercapacitors was used of polyvinyl alcohol (PVA)/phosphoric acid (H 3 PO 4 ) as a gel electrolyte and the BaTiO 3 film as a separator film. The carbon nanomaterials, gel electrolyte surface, and electrode films were characterized by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The specific capacitance of the symmetric paper supercapacitors using charge-discharge technique and C-V curves at the voltage scan rates 20 mV/s and 150 mV/s have been investigated. The symmetric paper supercapacitor based on the CNTs electrode showed higher specific capacitance 411 F g − 1 , compared to GNPs and graphene supercapacitors. Also by electrochemical impedance spectroscopy, the Nyquist curves of the symmetric paper supercapacitors have been plotted. For the symmetric paper supercapacitors based on the GNPs, graphene and CNTs electrodes the equivalent series resistance…

'Capable-of-being-shaped' synthetic compounds are prevailing today over horn, bone, leather, wood, stone, metal, glass, or ceramic in products that were previously left to natural materials. Plastic is, in fact, economical, simple, adaptable, and waterproof. Also, it is durable and resilient to natural degradation (although microbial species capable of degrading plastics do exist). In becoming a waste, plastic accumulation adversely affects ecosystems. The majority of plastic debris pollutes waters, accumulating in oceans. And, the behaviour and the quantity of plastic, which has become waste, are rather well documented in the water, in fact. This review collects existing information on plastics in the soil, paying particular attention to both their degradation and possible re-uses. The use of plastics in agriculture is also considered. The discussion is organised according to their resin type and the identification codes used in recycling programs. In addition, options for post-consumer plastics are considered. Acknowledged indicators do not exist, and future study they will have…

The main aim of this study is to examine the impact of board meeting frequency on firm performance of deposit money banks in Nigeria. Data used for the study were spawned from annual reports of the deposit money banks listed on Nigeria stock exchange (NSE) market. We employed a panel regression to test the significant association amid variables. Our main empirical result shows a positive association amid board meeting frequency and firm performance. Although, our findings also show that board size was positive and not significant and firm size was negative and significant. The study recommended that management of banks should consider increasing their frequency of board meetings to at least four (4) meetings per year. This will allow the sampled deposit money banks to comply with the good governance code in Nigeria which states that companies must meet at least once per quarter.

Our objectives were to analyze and correlate the color, flavonoids, phenolics and antioxidants of 26 honey samples from 6 honey producing regions in the Sultanate of Oman. The Pfund method was used to measure color, aluminum chloride method for flavonoids determination, Folin-Ciocalteu method for phenolic measurement and DPPH assay to determine antioxidants. Sumer honey was the highest among other samples in terms of color, which ranged 129.8-336.2 mm pfund, flavonoids (1613-2890 mg/kg), phenolics (1624-2898 mg/kg) and antioxidants (7.8-48.6 mg/ml). There was a strong correlation between color, flavonoids and phenolics, where it's moderate between these parameters and antioxidants. The Omani honey was rich in color and phenolics compare to other honey and regarded as a good source of antioxidants to the human diet.

Climate change is a major development challenge in sub-Saharan Africa. This region is highly vulnerable to negative impacts of climate change due to low adaptive capacity and overreliance on rain-fed agriculture for food security and livelihood. Climate information services (CIS) have been developed in Kenya to help enhance farmers' adaptation to climatic shocks, but their access and utilisation remain low. The factors that influence farmers' access and use of CIS are not well-known. Using survey data from a sample of 250 households in Makueni County, this study estimated a two-step Heckprobit model to analyse the determinants of access and use of CIS. Results showed that the age of the household head reduced the likelihood of accessing CIS whereas household size, income, farm size, livelihood activity, television ownership and group membership increased it. Age, sex of the household head, and frequent exposure to drought reduced the likelihood of using CIS whereas access to improved seed, household income, radio ownership, and livelihood activity increased it. Efforts promoting…

Governments, worldwide, are committed to achieving sustainable development goals (SDGs). In a context where urban agglomerates consume roughly 80% of the global energy, of which buildings account for 40%, energy-efficient buildings can make a significant contribution to meeting SDGs 11 and 13. Currently, the implementation of energy efficiency measures (EEMs) in building is constrained by socioeconomic and technical barriers. Using empirical survey data, the drivers that affect both the supply of and demand for EEMs were identified. These drivers were then categorized within four clusters according to their importance in meeting supply and demand priorities. The following critical drivers were identified: standardization, low transaction costs, energy prices, and stability of the regulatory framework. The findings indicated that an effective energy policy provides consumers with reliable information and project developers with a stable regulatory environment. Investment behavior is rational and responsive to reliable information that prompts a switch toward sustainable building…

Medicinal plants have been the basis for discovery of various important marketed drugs. Xanthine is one such lead molecule. Xanthines in various forms (caffeine, theophylline, theobromine, etc) are abode in tea, coffee, cocoa, chocolate etc. giving them popular recognition. These compounds are best known for their diverse pharmaceutical applications as cyclic nucleotide phosphodiesterase inhibition, antagonization of adenosine receptor, anti-inflammatory, anti-microbial, anti-oxidant and anti-tumor activities. These properties incentivize to use xanthine as scaffold to develop new derivatives. Chemical synthesis contributes greater diversity in xanthine based derivatisation. With highlighting the existing challenges in chemical synthesis, the present review focuses the probable solution to fill existing lacuna. The review summarizes the available knowledge of xanthine based drugs development along with exploring new xanthine led chemical synthesis path for bringing diversification in xanthine based research. The main objective of this review is to explore the immense potential of…

BACKGROUND: Circulating-free DNA (cfDNA) is under investigation as a liquid biopsy of cancer for early detection, monitoring disease progression and therapeutic response. This systematic review of the primary cfDNA literature aims to identify and evaluate factors that influence recovery of cfDNA, and to outline evidence-based recommendations for standardization of methods. METHODS: A search of the Ovid and Cochrane databases was undertaken in May 2018 to obtain relevant literature on cfDNA isolation and quantification. Retrieved titles and abstracts were reviewed by two authors. The factors evaluated include choice of specimen type (plasma or serum); time-to-processing of whole blood; blood specimen tube; centrifugation protocol (speed, time, temperature and number of spins); and methods of cfDNA isolation and quantification. FINDINGS: Of 4,172 articles identified through the database search, 52 proceeded to full-text review and 37 met the criteria for inclusion. A quantitative analysis was not possible, due to significant heterogeneity in methodological approaches between studies.…

This paper presents an overview of previous studies on the environmental impact (EI) and toxicity of producing recycled concrete aggregates (RCA), fly ash (FA), cement, superplasticizer, and water as raw materials, and also on the effect of replacing cement and natural aggregates (NA) with FA and RCA, respectively, on the mentioned aspects. EI and toxicity were analysed simultaneously because considering concrete with alternative materials as sustainable depends on whether their risk assessment is high. Therefore, this study mainly focuses on the cradle-to-gate EI of one cubic meter of concrete, namely abiotic depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), photochemical ozone creation (POCP), acidification potential (AP), eutrophication potential (EP), non-renewable energy (PE-NRe) and renewable energy (PE-Re). In terms of toxicity, leachability (chemical and ecotoxicological characterization) was considered. The results also include the economic performance of these materials, and show that the incorporation of FA in concrete…

In this paper, a poly (glycine) modified carbon paste electrode (PGMCPE) for sensitive determination of Tartrazine (Tz) was developed. The electrochemical behaviors of Tz at the PGMCPE were investigated by cyclic voltammetry, differential voltammetry and the results showed that the polymer film on electrode exhibited excellent electrocatalytic activity for the electrochemical oxidation of Tz in phosphate buffer solution, pH 7 (PBS). The influencing factors containing a supporting electrolyte, pH of the solution, deposition potential, amount of Tz and scan rate were investigated. The sensor exhibited two linear behavior in the range of 1 × 10 −6 to 2.7 × 10 −5 mol L −1 and 3.5 × 10 −5 to 8.7 × 10 −5 mol L −1 for Tz (correlation coefficients: 0.991 and 0.995 respectively) with detection limit (LOD) of 2.83 × 10 −7 mol L −1 , limit of quantification (LOQ) 9.4 × 10 −7 mol L −1 and detection sensitivity (2.0452 μA/μM), for Tz. The results show that the biosensor is sensitive and useful for the determination of Tz.

Recently, there have been efforts by stakeholders to monitor illegal mining ( galamsey) activities, foster their formalization and reclaim the many abandoned wastelands in Ghana. However, limited information exists on the locations, abundance, scope and scale of galamsey types, which hinders the development of effective policy response. This study attempts to map and analyze the distribution patterns, abundance, activity statuses and the extents of nine (9) galamsey types within eleven (11) Municipal and District Assemblies (MDAs) of Ghana's Western Region. It explores the utility of field-based survey, using the Open Data Kit (ODK) system, ArcGIS and Google Earth Imagery to map and visualize different galamsey types under a hostile working environment. A total of 911 galamsey sightings, of which 547 were found in clusters (corresponding to approximately 7106 individual operational units) and 364 in stand-alone mode. Overall, a total of 7470 individual galamsey operations were encountered in 312 different communities (towns and villages). Operationally, the Alluvial Washing Board,…

Nanostructured mesoporous titanium dioxide (TiO 2 ) particles with high specific surface area and average crystallite domain sizes within 2 nm and 30 nm have been prepared via the sol-gel and hydrothermal procedures. The characteristics of produced nanoparticles have been tested using X-Ray Diffraction (XRD), Brunauer–Emmett–Teller ( BET ) surface area analysis, Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FTIR), and Raman Spectroscopy as a function of temperature for their microstructural, porosity, morphological, structural and absorption properties. The as-synthesized TiO 2 nanostructures were attempted as catalysts in Rhodamine B and Sudan III dyes' photocatalytic decomposition in a batch reactor with the assistance of Ultra Violet (UV) light. The results show that for catalysts calcined at 300 °C, ∼100 % decomposition of Sudan III dye was observed when Hydrothermal based catalyst was used whiles ∼94 % decomposition of Rhodamine B dye was observed using the sol-gel based catalysts. These synthesized TiO 2 nanoparticles have promising potential applications in…

Drawing on hydrology, rainfall, and climatic data from the past 25 years, this article investigates the effects of climate change on water resources in the transnational Blue Nile Basin (BNB). The primary focus is on determining the long-term temporal and seasonal changes in the flows of the Blue Nile in Ethiopia at the border to Sudan. This is important because the Blue Nile is the main tributary to the Nile river, the lifeline of both Sudan and Egypt. Therefore, to begin with long-term trends in hydrological time series were detected by means of both parametric and nonparametric techniques. The Soil and Water Assessment Tool (SWAT) model was calibrated using several sub-basins and new high-resolution land use and soil maps. Future climate change impacts were projected using data from the Climate Forecast System Reanalysis (CFSR) of the National Centers for Environmental Predictions based on three different climate change scenarios from the Coupled Model Intercomparison Project (CMIP3). Projected time series were analysed for changes in rainfall and streamflow trends. Climate…

The Langmuir-Blodgett (LB) technique is a way of making supra-molecular assembly in ultrathin films with a controlled layered structure and crystal parameter, which have many envisioned technological applications for optical and molecular electronic devices as well as signal processing and transformation. Probably LB technique is the best method to manipulate materials at molecular level and provides a scope to realize the molecular electronics in reality. In this review article, we have discussed about the general introduction of LB technique and recent development on LB and related system including (i) LB methodology, (ii) characterizations of LB films, (iii) LB films and molecular electronics, (iv) historical review of LB films, (v) research and applications including fundamental research and application towards devices.

The aim of this work was to compare the antioxidant and angiotensin converting enzyme (ACE) inhibitory properties of Moringa oleifera seed protein isolate (ISO) and its enzymatic protein hydrolysates. ISO was subjected to enzymatic (alcalase, pepsin and trypsin) hydrolysis to obtain alcalase isolate, pepsin isolate and trypsin isolate hydrolysates (AIH, PIH, TIH). Amino acid composition was similar for the samples except that TIH had lower Sulphur-containing amino acids while PIH was lower in tryptophan. All the samples were tested for antioxidant properties through free radical scavenging abilities such as 2,2 diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assays as well as ferric reducing antioxidant power (FRAP) and metal ion chelation assays. The maximum percentage inhibition obtained for the samples from the different assays are: DPPH, 36% (PIH); FRAP, 0.04% (PIH); hydroxyl radical scavenging activity, 42.98% (ISO); and inhibition of metal ion chelation, 29.46% (AIH). AIH (79.3%) had the highest ACE-inhibitory activity followed by TIH (75.1%) while PIH (43.0%)…

To date high ionic conducting polymer electrolytes are of great interest because of their potential applications in various electrochemical devices such as batteries, fuel cells, solar cells and super capacitors etc., as electrolytes. Ion conduction through polymer electrolytes can occur mostly in amorphous environment exists above their glass transition temperature (T g ). In order to improve ionic conductivity, many approaches such as addition of plasticizer, blending of polymers, nano composite have been employed. This paper reviews the influence of different plasticizers/additives on the ion transport mechanism of Poly(vinyl alcohol) (PVA)-LiClO 4 polymer electrolytes since poly vinyl alcohol is a semi crystalline, synthetic biodegradable polymer and lithium perchlorate is one of the most moisture resistant lithium salts. This review also reveals the relation between dynamical disorder in polymer electrolyte with ionic conductivity.

Aims This study aimed to evaluate in vitro antioxidant capacity of olive leaf extract (OLE), Olea europaea L., and its protective effect on peroxyl radical-induced oxidative damage in human erythrocytes. Main methods The OLE was evaluated by the following assays: i) total phenolic and flavonoid content; ii) oleuropein content; iii) Ferric reducing antioxidant power (FRAP); iv) antioxidant activity against ABTS + , DPPH and reactive oxygen and nitrogen species: superoxide anion ( O 2 · − ), hypochlorous acid (HOCl) and nitric oxide (NO ) and v) protective effect on peroxyl radical-induced oxidative damages in human erythrocytes as hemolysis, thiobarbituric acid reactive substances (TBARS) formation and oxyhemoglobin oxidation. Key findings Total phenolic and flavonoid contents were 131.7 ± 9.4 mg gallic acid equivalents/g dry weight (dw) and 19.4 ± 1.3 mg quercetin equivalents/g dw, respectively. Oleuropein content was 25.5 ± 5.2 mg/g dw. FRAP analysis was 281.8 ± 22.8 mg trolox equivalent/g dw and OLE inhibited ABTS + (50% effective concentration (EC 50 ) = 16.1 ± 1.2 μg/mL) and…

In this research work we have examined the flow of Williamson liquid film fluid with heat transmission and having the impact of thermal radiation embedded in a permeable medium over a time dependent stretching surface. The fluid flow of liquid films is assumed in two dimensions. By using suitable similarity transformation the governing non-linear partial differential equations have been transformed into non-linear differential equations. An optimal approach has been used to acquire the solution of the modelled problem. The convergence of the technique has been shown numerically. The impact of the Skin friction and Nusslet number and their influence on thin film flow are shown numerically. Thermal radiation, unsteadiness effect and porosity have mainly focused in this paper. Furthermore, for conception and physical demonstration the entrenched parameters, like porosity parameter k , Prandtl number Pr , unsteadiness parameter S , Radiation parameter R d , Magnetic parameter M , and Williamson fluid parameter have been discussed graphically in detail with their effect on liquid film…

A cornerstone of statistical inference, the maximum entropy framework is being increasingly applied to construct descriptive and predictive models of biological systems, especially complex biological networks, from large experimental data sets. Both its broad applicability and the success it obtained in different contexts hinge upon its conceptual simplicity and mathematical soundness. Here we try to concisely review the basic elements of the maximum entropy principle, starting from the notion of 'entropy', and describe its usefulness for the analysis of biological systems. As examples, we focus specifically on the problem of reconstructing gene interaction networks from expression data and on recent work attempting to expand our system-level understanding of bacterial metabolism. Finally, we highlight some extensions and potential limitations of the maximum entropy approach, and point to more recent developments that are likely to play a key role in the upcoming challenges of extracting structures and information from increasingly rich, high-throughput biological data.

Establishing exclosures has become common in Ethiopia, especially in the central and northern highlands, where they serve as a response to persistent forest degradation, affecting forest resources and ecosystem services. We investigated changes in vegetation composition, aboveground biomass and soil properties after establishing an exclosure on degraded communal grazing land in Aba-Gerima watershed, North-Western Ethiopia. We selected 4-yr-old exclosure and paired the selected exclosure with an adjacent communal grazing land. In the exclosure, we recorded 46 plant species representing 32 families, whereas we recorded 18 plant species representing 13 families in the adjacent communal grazing lands. Most of the identified woody species are economically important. We observed significant differences between the exclosure and adjacent grazing land in woody species richness, diversity and evenness. Exclosure displayed higher woody species density, basal area and aboveground woody biomass compared to the adjacent grazing land. Landscape position influenced vegetation composition, richness…

There has been a steady increase in the interest towards employing nanoliposomes as colloidal drug delivery systems, particularly in the last few years. Their biocompatibility nature along with the possibility of encapsulation of lipid-soluble, water-soluble and amphipathic molecules and compounds are among the advantages of employing these lipidic nanocarriers. A challenge in the successful formulation of nanoliposomal systems is to control the critical physicochemical properties, which impact their in vivo performance, and validating analytical techniques that can adequately characterize these nanostructures. Of particular interest are the chemical composition of nanoliposomes, their phase transition temperature, state of the encapsulated material, encapsulation efficiency, particle size distribution, morphology, internal structure, lamellarity, surface charge, and drug release pattern. These attributes are highly important in revealing the supramolecular arrangement of nanoliposomes and incorporated drugs and ensuring the stability of the formulation as well as consistent drug…

In this work, a new extraction process using steam explosion at high temperature and pressure was developed, to drastically shorten the extraction time and improved extraction of the essential oil from citrus peels. In steam explosion process, the material is subjected to the high-pressure saturated steam following by substantially dropping the pressure through an angle valve to a vacuum tank. The optimum essential oil yield by the steam explosion was obtained at the 170 °C, 8 bar in 240 seconds duration time. The essential oil extraction of a certain amount of citrus peels by hydro-distillation took nearly eight times longer than explosion extraction process. The obtained citrus oil from hydro-distillation processes had 10 to 13 major components more than‏ the steam explosion, as shown by gas chromatography (GC-MS). The maximum product yield of Limonene, a major favorable component, were 77% and 100% in hydro-distillation and steam explosion processes, respectively.

One of the prime concern of policy makers should be to ensure energy security in the country. The case of Pakistan is interesting in a sense that with the growing age of the country, the increasing reliance on imported sources of energy is resulting in huge demand-supply gap which is evident in suppressed demand for electricity and natural gas. It has social, economic and environmental consequences. Most of the countries in the world have shifted their focus from imported to indigenous resources which are more often cheap, environmental friendly and provide competitiveness . The study reveals, through exploring secondary data, descriptive analysis, Johanson Cointegration and Granger Causality test results based on error correction model, energy insecurity is damaging for environment and socio-economic conditions. The study suggests policy makers to move toward long run energy security to get environmental and socio-economic sustainability in the country through minimizing reliance on imported energy and promoting energy efficiency.

Alkaline proteases have applications in numerous industries. In this study, we have isolated and screened proteolytic bacteria from poultry wastes mixed soil and identified two bacterial isolates as Bacillus subtilis AKAL7 and Exiguobacterium indicum AKAL11 based on 16S rDNA sequencing. Maximum level of protease production was achieved after 24 h of fermentation in a basal medium. The optimal temperature, initial pH of the media and agitation for alkaline protease production by these two isolates were 30 °C, pH 9.0 and 120 rpm, respectively. The both bacterial isolates produced maximum level of protease with 3.0% organic municipal solid wastes (OMSW) as the sole source of carbon and nitrogen under previously optimized fermentation conditions. In comparison with the shake flask, protease production increased about 2.5-fold in the bioreactor with reduction in fermentation period. The partial purification of protease resulted in a final 45.67 and 34.86-fold purified protease with a specific activity of 8335.34 and 9918.91 U/mg protein and a typical yield of 9.75 and 9.41% from B.…

Future land cover changes may result in adjustments to biophysical drivers impacting on net ecosystem carbon exchange (NEE), catchment water use through evapotranspiration (ET), and the surface energy balance through a change in albedo. The Land Change Modeller (Idrisi Terrset 18.08) and land cover for 2000 and 2014 are used to create a future scenario of land cover for two catchment with different land management systems in the Eastern Cape Province for the year 2030. In the S50E catchment, a dualistic farming system, the trend shows that grasslands represented 57% of the total catchment area in 2014 decreasing to 52% by 2030 with losses likely to favour a gain in woody plants and cultivated land. In T35B, a commercial system, persistence of grasslands is modelled with approximately 80% coverage in both years, representing a more stable system. Finally, for S50E, NEE and ET will increase under this land cover change scenario leading to increased carbon sequestration but less water availability and corresponding surface temperature increases. This implies that rehabilitation and…

An explicit study of comparison on the basis of structure and electronic properties of ZnO nanostructures was discussed. ZnO synthesized by sol-gel and hydrothermal method without using any surfactant leads to the formation of two different morphologies. Rietveld crystal structure refinement of X-ray diffraction patterns confirmed the wurtzite structure of both samples. Raman spectra also confirmed the wurtzite phase formation and improved crystallinity in sample synthesized by hydrothermal route that are concurrent with results obtained from X-ray diffraction. Field-emission scanning electron microscopy revealed the formation of ZnO spherical nanoparticle structure for sol-gel method and flower like μ- structure for ZnO prepared through hydrothermal route. Williamson-Hall equations applied to study the strain and stress parameters present in the material, show the decrease in their values as the crystal size increases. Energy band gap is calculated using diffused reflectance spectroscopy. Near-edge X-ray absorption fine-structure measurements at O K- and Zn L 3,2 - edges simulated…

Electrospun nanofibers of polyvinyl alcohol (PVA) have poor mechanical strength. As such their use has often been avoided, particularly in applications that require high mechanical properties. The objective of this study is to increase the mechanical properties of PVA nanofiber mats via physical crosslinking with solvent vapor treatment using organic solvents, dimethyl sulfoxide (DMSO), N, N-dimethyl formamide (DMF), and methanol. The effect of solvent vapor treatment on PVA nanofibers is clearly observed by scanning electron microscope (SEM). The tensile strength increased by over 60%, 90%, and 115% after solvent vapor treatment with DMF at a temperature of 40 °C for 2 h, 4 h, and 8 h, respectively, compared to untreated PVA nanofibers. In addition, Young's modulus of PVA nanofiber mats also increased after DMF treatment. As a comparison, DMSO and methanol were also used in solvent vapor treatment because of differences in their polymer-solvent affinity. Results showed that the highest improvement (100%) in mechanical strength was obtained using DMF. This study shows that solvent…

In this study, antioxidant, chemical, microbiological, and sensory attributes changes taking place during the production of probiotic yoghurt using pulp of soursop ( Annona muricata ), sweetsop ( Annona squamosa ), and custard apple ( Annona reticulata ) were evaluated. The products were stored at 4 °C for 28 d, during which time physicochemical properties and viability of probiotic bacteria and yoghurt starter cultures were evaluated weekly. Yoghurts prepared with fruit pulps displayed higher antioxidant activities on the first day of storage compared to the control. During the storage, the addition of fruit pulps influenced ( p < 0.05 ) pH, titratable acidity, syneresis and counts of B. animalis ssp . lactis BB-12 of yoghurts, whereas counts of Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus were found to be insignificant. Sensory evaluation results showed that yoghurt containing soursop fruit pulp had better sensory scores than other treatments. Therefore, these results proved that soursop can be used to produce probiotic yoghurt with enhanced…

This paper presents the effect of modified halloysite nanotubes on the sustained drug release mechanisms of sodium salicylate. Acid treatment and composite polymer-halloysite modification techniques were adopted in this study. After each modification, sodium salicylate drug was loaded, and in vitro release properties were evaluated and compared with the raw unmodified halloysite nanotubes. The results obtained from SEM, TEM and FTIR analyses indicate that both acid treatment and composite formation have no effect on the tubular structure and morphology of halloysite. However, modification of the halloysite nanotubes did influence the drug release rate. In the acid treatment modification, there was an improved loading of sodium salicylate drug which resulted in the sustain release of large amount of the sodium salicylate. In the polymer/halloysite composite formation, a consistent layer of polymer was formed around the halloysite during the composite formation and thus delayed release providing sustained release of sodium salicylate drug over a longer period of time as compared to…

Due to recent increases in the price of Ni, steel use is currently undergoing a global shift from austenitic stainless steels to ferritic stainless steels. In this study, the corrosion behavior of four types ferritic stainless steels with different Cr contents was investigated to study the effect of Cr content on the corrosion resistance in a sulfuric acid solution. The polarization curves of the ferritic stainless steel with the highest Cr content indicated the best corrosion resistance. No corrosion was observed for the stainless steel with 24 mass% Cr after a potential sweep based on ex-situ SEM images. Corrosion resistivity was improved for high Cr content (>24 mass%) stainless steel because it is considered to form a stable passivation layer.

It is important to identify and understand important factors underpinning the integration of information and communication technology (ICT) in schools. And, it is important that ICT is adopted in a sound pedagogical manner. The aim with this study was to suggest a model for the actual use of ICT in schools and how it may be related to important factors such as technological pedagogical expectations. The design of the model was inspired by TAM2 and UTAUT models, but with some modifications. We have developed a model which highlight the pedagogical aspects beyond the technical ones. Furthermore, our suggested model also include the adoption of digital techniques in everyday life as a potential predictor of adoption of ICT at work. The sample consists of 122 teachers and we analyzed the model with a structural equation model. This study contributes with a suggested model including a new construct for measuring expected performance from a technological pedagogical point of view. This new construct was a significant predictor to actual use of ICT in school. Furthermore we also developed…

PURPOSE: To conduct a systematic review that examined the effect of dance interventions on balance, gait and functional mobility outcomes in adults with neurological conditions other than Parkinson's disease. METHODS: A systematic search of relevant databases was conducted. Data extraction and methodological appraisal were performed by two independent authors. RESULTS: Nine studies were included (4 pre-post studies with no control group, 3 case reports, and 2 controlled studies) and results of the methodological quality assessment ranged from poor to good. Study groups included stroke, multiple sclerosis, spinal cord injury, and Huntington's disease. Dance interventions varied in frequency, type and duration, and only 1 study reported intensity. Study dropout rates ranged from 20-44%, and 88-100% of dance classes were attended. Only 3 studies mentioned adverse events, of which there were none. A summary of results revealed significant changes in spatiotemporal gait parameters, Berg Balance Scale scores, Timed Up and Go test and six-minute walk test that were similar to or greater…

A potential new clinical disorder is arising due to the addiction to cellphones called nomophobia-or feelings of discomfort or anxiety experienced by individuals when they are unable to use their mobile phones or utilize the conveniences these devices provide. However, before being able to officially classify this disorder as clinically relevant, more research needs to be conducted to determine how nomophobia relates to existing disorders. In a sample of 397 undergraduate students, the present study examined the relationship between the Nomophobia Questionnaire (NMP-Q) and the Obsessiveness Content Scale (OBS) of the Minnesota Multiphasic Personality Inventory-2 (the MMPI-2). Confirmatory factor analysis (CFA) was used to test whether the OBS Content Scale would be related to a one-factor NMP-Q solution (Fig. 1) or a four-factor NMP-Q solution (Fig. 2). Convergent and divergent validity were also investigated. The four-factor model was a better fit than the one-factor model as indicated by most fit indices. The findings showed that the OBS latent variable was correlated with all of…

The influence of accelerated weathering, xenon-arc light and freeze-thaw cycling on wood plastic composites extruded from a recycled plastic was studied. The results showed that, in general, weathering had a stronger impact on samples made from plastic waste compared to a sample made from virgin material. After weathering, the mechanical properties, tensile and flexural, were reduced by 2-30%, depending on the plastic source. Wettability of the samples was shown to play a significant role in their stability. Chemical analysis with infrared spectroscopy and surface observation with a scan electron microscope confirmed the mechanical test results. Incorporation of carbon black retained the properties during weathering, reducing the wettability of the sample, diminishing the change of mechanical properties, and improving color stability.

The pace of change in land use and cover in Ethiopia depends on three main factors that cause pressure on agriculture land: resettlement programmes, population growth and increasing agricultural investments. Gambella is one of the regions of Ethiopia that attracts large-scale agricultural investments that extensively drive land use and cover changes in the region. The aim of this study is to examine the rate, extent and distribution of various land use and cover changes in Gambella Regional State, Ethiopia, from 1987 to 2017. The analysis is mainly based on Landsat 5 and Sentinel 2A satellite images and fieldwork. Two Landsat Thematic Mapper and a Sentinel 2A image were used for determining the maximum likelihood of land use/cover classification. The results show that farmland decreased by 26 km 2 from 1987 to 2000; however, during the last two decades, agricultural land area increased by 599 km 2 , mainly at the cost of tropical grasslands and forests. We found that areas cultivated by smallholder farmers increased by 9.17% from 1987 to 2000. However, small-scale farm activities…

OBJECTIVES: We determined and structurally analyzed the reported effect of hydroxyapatite (HA) bone substitute on alveolar bone regeneration. To the best of our knowledge, no systematic reviews have previously reported the bone regenerative effect of the HA bone substitute. MATERIALS AND METHODS: A literature search was performed for articles published up to August 2015 using MEDLINE with the search terms "hydroxyapatite," "bone regeneration," and "alveolar bone" as well as their known synonyms. The inclusion criteria were set up for human trials with at least five patients. The literature search, eligible article selection, and data extraction were independently performed by two readers, and their agreement was reported by κ value. RESULTS: Of the 504 studies found using the MEDLINE literature search, 241 were included for further steps (inter-reader agreement, κ = 0.968). Abstract screening yielded 74 studies (κ = 0.910), with 42 completely fulfilling the inclusion criteria (κ = 0.864). In a final step, 42 studies were further analyzed, with 17 and 25 studies with and without…

Kedrostis africana , is a tuberous plant commonly used by traditional healers in the Eastern Cape Province of South Africa for the management of obesity. The aim of this study was to investigate the antiobesity and cytotoxic effects of Kedrostis africana extracts in vitro The α-amylase, α-glucosidase and lipase inhibitory activities of aqueous and ethanol extracts of Kedrostis africana tuber were investigated while the cytotoxic effects of these extracts were analyzed using Hoechst 33342 and propidium iodide (PI) dual staining in combination with Molecular Devices ImageXpress Micro XLS Widefield microscope for high content analysis on human cervical (HeLa) cell line. The ethanol extract exhibited the strongest inhibitory effect on pancreatic lipase (IC 50 = 381.86 μg/ml) and on α-glucosidase (IC 50 = 157.99 μg/mL) while the aqueous extract has strongest α-amylase (IC 50 = 439.45 μg/ml). Both tuber extracts were found nontoxic at tested concentrations on HeLa cell lines as confirmed by the Hoechst 33342 and propidium iodide dual staining respectively. This study revealed that both…

A synthetic way of chiral zirconium quantum dots (Zr QDs) was presented for the first time using L(+)-ascorbic acid acts as a surface as well as chiral ligands. Different spectroscopic and microscopic analysis was performed for thorough characterization of Zr QDs. As-synthesized QDs exhibited fluorescence and circular dichroism properties, and the peaks were located at 412 nm and 352 nm, respectively. MTT assay was performed to test the cytotoxicity of the synthesized Zr QDs against rat brain glioma C6 cells. Synthesized QDs was further conjugated with anti-infectious bronchitis virus (IBV) antibodies of coronavirus to form an immunolink at the presence of the target analyte and anti-IBV antibody-conjugated magneto-plasmonic nanoparticles (MPNPs). The fluorescence properties of immuno-conjugated QD-MP NPs nanohybrids through separation by an external magnetic field enabled biosensing of coronavirus with a limit of detection of 79.15 EID/50 μL.

Therapeutic drug delivery systems using polymeric materials is an emerging field of research. However, the use of certain polymers has gained much-needed attention by the researchers due to their low toxic nature. In recent years, chitosan has gained popularity as a potential biodegradable polymer that can be used as a component in drug delivery systems. In this study, we synthesized a chitosan derivative that is composed of both folic acid and zinc and may serve as a viable component of a drug delivery system. The results of Fourier Transform Infrared Spectroscopy (FTIR), solid-state 13 C Nuclear Magnetic Resonance Spectroscopy (NMR) and UV-visible Spectroscopy demonstrated a substantial difference between chitosan and ZnS/Chitosan-Folic acid derivative. The results were also confirmed using Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM-EDS) techniques. The average particle size of the ZnS/Chitosan-Folic acid system was measured to be 463.67 ± 5.76 nm, showing that the product is within the nano-size range.

= 14.18) completed an online questionnaire. This included a self-report, response to failures in digital technology scale, a measure of Fear of Missing Out, Internet addiction, and the BIG-5 personality traits. Fear of Missing Out, Internet addiction, extraversion, and neuroticism all served as significant positive predictors for maladaptive responses to failures in digital technology. Agreeableness, conscientiousness, and openness acted as significant negative predictors for maladaptive responses to failures in digital technology. The responses to failures in digital technology scale presented good internal reliability, with items loading onto four key factors, these being; 'maladaptive responses', 'adaptive responses', 'external support and venting frustrations', and 'anger and resignation'. The findings are discussed in the context of the end user experience, particularly where individual differences are seen to influence the level of frustration arising from a failure. The findings are also seen as a potential route for reducing the negative impact of failures in digital…

Background Marijuana consumption is estimated as upwards of 9.5% of the U.S. adult population. Nevertheless, few trials exist on potential implications for surgical outcomes amongst users. Methods A current literature review explored marijuana's effects to answer: (I) How is marijuana use screened for in clinical and pre-operative settings? (II) What are potential surgical complications of marijuana use? (III) How should surgeons handle patient marijuana use regarding elective surgery? (IV) Are marijuana's effects the same or different from those of tobacco? Results In acute settings, marijuana's effects peaked at approximately 1 hour post initiation, lasting 2–4 hours. Marijuana increased cardiac workload, myocardial infarctions and strokes in young, chronic users. Cannabis caused similar pulmonary complications to those of a tobacco smoker. Marijuana caused airway obstruction and increased anesthetic dosages needed to place laryngeal airways. Use within 72 hours of general anesthesia was advised against. In vitro and in vivo studies were contradictory regarding prothrombic or…

In this study, vesicular basalt volcanic rock was taken and its application for adsorption of chromium (VI) from aqueous solution was investigated. Different physical and chemical properties of the powdered rock was studied using Fourier transform infrared spectroscopy (FT-IR), Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). A series of batch experiments were carried out to study the effect of various experimental parameters (pH, ionic strength and contact time) on chromium (VI) adsorption. It was found that the removal efficiency of chromium (VI) decreased with increasing pH and ionic strength. The adsorption process was optimal at pH 2. The maximum adsorption capacity was 79.20 mg kg −1 at an initial concentration of 5.0 mg L −1 and adsorbent dosage of 50 g L −1 . In individual adsorption tests, Pseudo-second-order kinetic and Freundlich isotherm models could better describe chromium (VI) adsorption on the vesicular basalt. This study indicated that vesicular basalt, which is inexpensive, has the potential to remove chromium (VI) from polluted water.

Here, we demonstrate a very efficient simultaneous approach of bioenergy generation from wastewater and added-value compounds production by using a photosynthetic microalgae microbial fuel cells (PMFC), based on polybenzimidazole (PBI) composite membrane as separator. The use of PBI was proved to be very promising, even more convenient than Nafion™ in terms of energy performances as well as cost and sustainability. This polymer is also easily autoclavable, so allowing a re-use of the separator with a consequent beneficial cost effect. Two PMFCs were investigated: 1) Pt electrocatalysed and 2) Pt-free. They were operated as microbial carbon capture (MCC) device under continuous illumination, by using a domestic wastewater as anolyte and Scenedesmus acutus strain in the catholyte. The Pt-based cell allowed to generate higher volumetric power density (∼400 mW m −3 ) after more than 100 operating days. This resulted in an improved wastewater treatment efficiency, determined in terms of normalised energy recovery ( NER > 0.19 kWh kg COD −1 in case of Pt). The CO 2 fixation of the…

This paper studied the fire resistance of rice husk ash concrete. An experimental method was adopted as the research design in this work, which produced one hundred and eighty four (184) concrete specimens with the addition of rice husk ash in weighted percentages of 5%, 10% and 15% respectively. They were cured and tested at 7 days, 28 days, 30 days, 60 days, 90 days, 120 days, 150 days and 200 days. After the targeted curing days, the specimen were exposed to temperatures of 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, 600 °C and 700 °C for 2 hours in a muffle electric furnace. The results show that the pozzolanic concrete and control concrete fire resistance ranged between (60%-96%) for (200 °C-400 °C), (41%-55%) at 500 °C, and (13%-26%) for (600 °C-700 °C). It is concluded that 5% weighted RHA concrete performs better in fire than others.