6,846 research outputs found
Financial Intelligence and the Quality of Higher Education in Africa
Improving the quality of curriculum development in private Universities in Africa from time to time is a task that is very essential to achieving effectiveness, efficiency, and relevance in the higher education system. Financial Intelligence is one of the five components of a twenty first century education, the kind of education that actually delivers the financial andwealth building results that people deserve. Unfortunately, a 21st century education is not something that is currently obtainable in the traditional school system in Africa, requiring instead that students go out and seek it on their own. This paper, using the explorative methodology, establishes that without financial intelligence, graduates from African private higher education schools will be forced to follow the road of financial disaster, ruin, and anti-excellence which most people travelled. It therefore recommends among others that financial intelligence be integrated into the curriculum of African Universities to enable students know the how of making money, work for them rather than simply working for money.Keywords: Financial Intelligence, Quality, Higher Education, Afric
Emerg Infect Dis
The identification of new materials capable of sustaining a high electron emission current is a key requirement in the development of the next generation of cold cathode devices and technology. Compatibility with large volume material production methods is a further important practical consideration with solution chemistry-based methods providing for route to industrial scale-up. Here we demonstrate a new class of organic-inorganic hybrid material based on polypyrrole and zinc oxide (PPy/ZnO) nanofibers for use as a low-cost large-area cathode material. Solution chemistry based surfactant chemical oxidation polymerisation is used to synthesise the nanofibers and the macroscopic turn-on electric field for emission has been measured to be as low as 1.8 V/μm, with an emission current density of 1 mA/cm2 possible for an applied electric field of less than 4 V/μm. Specfic surface area measurements reveal a linear increase in the nanofiber surface area with ZnO incorporation, which when coupled with electron microscopy and x-ray diffraction analysis reveals that the wurtzite ZnO nanoparticles (around 45 nm in size) act as nucleation sites for the growth of PPy nanofibers. Our study demonstrates for the first time how an inorganic nanocrystal acting as a nucleation site allows for the tailored growth of the organic component without diminishing the overall electrical properties and opens the potential of a new type of organic-inorganic hybrid large-area cathode material. The broader impacts and advantages of using hybrid materials, when compared to other composite nanomaterial systems, as large area cathode materials are also discusse
Absorbate-Induced Piezochromism in a Porous Molecular Crystal
Atmospherically stable porous frameworks
and materials are interesting
for heterogeneous solid–gas applications. One motivation is
the direct and selective uptake of pollutant/hazardous gases, where
the material produces a measurable response in the presence of the
analyte. In this report, we present a combined experimental and theoretical
rationalization for the piezochromic response of a robust and porous
molecular crystal built from an extensively fluorinated trispyrazole.
The electronic response of the material is directly determined by
analyte uptake, which provokes a subtle lattice contraction and an
observable bathochromic shift in the optical absorption onset. Selectivity
for fluorinated absorbates is demonstrated, and toluene is also found
to crystallize within the pore. Furthermore, we demonstrate the application
of electronic structure calculations to predict a physicochemical
response, providing the foundations for the design of electronically
tunable porous solids with the chemical properties required for development
of novel gas-uptake media
The Subcellular Localization of an Aquaporin-2 Tetramer Depends on the Stoichiometry of Phosphorylated and Nonphosphorylated Monomers
In renal principal cells, vasopressin regulates the shuttling of the aquaporin (AQP)2 water channel between intracellular vesicles and the apical plasma membrane. Vasopressin-induced phosphorylation of AQP2 at serine 256 (S256) by protein kinase A (PKA) is essential for its localization in the membrane. However, phosphorylated AQP2 (p-AQP2) has also been detected in intracellular vesicles of noninduced principal cells. As AQP2 is expressed as homotetramers, we hypothesized that the number of p-AQP2 monomers in a tetramer might be critical for the its steady state distribution. Expressed in oocytes, AQP2-S256D and AQP2-S256A mimicked p-AQP2 and non–p-AQP2, respectively, as routing and function of AQP2-S256D and wild-type AQP2 (wt-AQP2) were identical, whereas AQP2-S256A was retained intracellularly. In coinjection experiments, AQP2-S256A and AQP2-S256D formed heterotetramers. Coinjection of different ratios of AQP2-S256A and AQP2-S256D cRNAs revealed that minimally three AQP2-S256D monomers in an AQP2 tetramer were essential for its plasma membrane localization. Therefore, our results suggest that in principal cells, minimally three monomers per AQP2 tetramer have to be phosphorylated for its steady state localization in the apical membrane. As other multisubunit channels are also regulated by phosphorylation, it is anticipated that the stoichiometry of their phosphorylated and nonphosphorylated subunits may fine-tune the activity or subcellular localization of these complexes
Repeatability of quantitative18F-FLT uptake measurements in solid tumors: an individual patient data multi-center meta-analysis
INTRODUCTION: 3'-deoxy-3'-[18F]fluorothymidine (18F-FLT) positron emission tomography (PET) provides a non-invasive method to assess cellular proliferation and response to antitumor therapy. Quantitative18F-FLT uptake metrics are being used for evaluation of proliferative response in investigational setting, however multi-center repeatability needs to be established. The aim of this study was to determine the repeatability of18F-FLT tumor uptake metrics by re-analyzing individual patient data from previously published reports using the same tumor segmentation method and repeatability metrics across cohorts. METHODS: A systematic search in PubMed, EMBASE.com and the Cochrane Library from inception-October 2016 yielded five18F-FLT repeatability cohorts in solid tumors.18F-FLT avid lesions were delineated using a 50% isocontour adapted for local background on test and retest scans. SUVmax, SUVmean, SUVpeak, proliferative volume and total lesion uptake (TLU) were calculated. Repeatability was assessed using the repeatability coefficient (RC = 1.96 × SD of test-retest differences), linear regression analysis, and the intra-class correlation coefficient (ICC). The impact of different lesion selection criteria was also evaluated. RESULTS: Images from four cohorts containing 30 patients with 52 lesions were obtained and analyzed (ten in breast cancer, nine in head and neck squamous cell carcinoma, and 33 in non-small cell lung cancer patients). A good correlation was found between test-retest data for all18F-FLT uptake metrics (R2 ≥ 0.93; ICC ≥ 0.96). Best repeatability was found for SUVpeak(RC: 23.1%), without significant differences in RC between different SUV metrics. Repeatability of proliferative volume (RC: 36.0%) and TLU (RC: 36.4%) was worse than SUV. Lesion selection methods based on SUVmax ≥ 4.0 improved the repeatability of volumetric metrics (RC: 26-28%), but did not affect the repeatability of SUV metrics. CONCLUSIONS: In multi-center studies, differences ≥ 25% in18F-FLT SUV metrics likely represent a true change in tumor uptake. Larger differences are required for FLT metrics comprising volume estimates when no lesion selection criteria are applied
Blockchain and SDN Architecture for Spectrum Management in Cellular Networks
Whereas 4G LTE networks have brought about an increase in data rates of mobile networks, they are unable to meet the capacity demands of future networks. Specifically, the centralized nature of the evolved packet core (EPC) makes the network non-scalable to match the exponential increase in number of wireless devices in addition to the complexities of diverse service requirements. The SDN concept has recently attracted a lot of research interest as a viable proposition for bringing about programmability and ease of network management while also offering flexibility for innovative network designs. However, current SDN implementations are not adapted to support business agreements that foster interoperability among mobile network operators (MNOs). This paper is an extended version of our earlier work and we intend to present a unified SDN and blockchain architecture with enhanced spectrum management features for enabling seamless user roaming capabilities between MNOs. Our simulation results show that users can experience no disruption in service with very minimal delay as they traverse between operators
Introducing lignin as a binder material for the aqueous production of NMC111 cathodes for Li-ion batteries
By enabling water-based cathode processing, the energy-intensive N-methyl-2-pyrrolidone (NMP) recovery step can be eliminated, reducing the cost and environmental impact of LIBs. Aqueous processing of high capacity Ni-containing LiNixMn1−x−yCoyO2 (NMC) cathodes is problematic due to lithium-ion(Li+) leaching, corrosion of the aluminum (Al) current collector, and the lack of aqueous soluble bio-derived binders. The present study investigates the potential of substituting and fully replacing the commonly used polyvinylidene fluoride (PVDF) and carboxymethyl cellulose (CMC) binders with abundant, bio-derived kraft lignin. This paper gives a holistic overview of the optimal conditions when employing these binders. For the first time, we demonstrate that NMC111 cathodes of comparable specific capacities to NMP/PVDF-based ones over 100 cycles or at high C-rates (5C) can be formulated in water using lignin or CMC/lignin as binder materials. Cyclic voltammetry (CV) revealed that kraft lignin undergoes a redox reaction with the electrolyte between 2.8 and 4.5 V, which diminishes upon subsequent cycles. Differential scanning calorimetry (DSC) revealed that lignin is thermally stable up to 152 °C. Rheology measurements showed that replacing NMP with water allows for a solvent reduction. The cathodes fabricated using an aqueous slurry should be dried at 50 °C, as extensive surface cracks detected using scanning electron microscopy (SEM) diminish. Li+ leaching from NMC111 and NaOH species from kraft lignin caused an increase in pH during aqueous slurry fabrication. A carbon-coated Al foil (C-Al) prevented Al corrosion and increased the lignin cathode's mechanical strength revealing lignin's exceptional binding abilities to carbon. The electrolyte wettability decreased for calendered lignin-containing cathodes with low porosity and a large carbon black/lignin matrix
Prevalence of Escherichia coli some public water sources in Gusau Municipal, North Western Nigeria
This study investigated the presence of Escherichia coli from some public water sources in Gusau municipal, north- western Nigeria. This was done by determining the total coliform counts and the presence of Escherichia coli and its antibiotic susceptibility profile. A total of 180 well 60 tap and 60 packaged water samples were obtained from Gusau municipal on weekly basis over a period of seven month (August, 2006-Feb, 2007) covering part of rainy and dry seasons. Standard procedures were used for the identification of Escherichia coli and for estimating total coliform counts. All samples had coliform counts higher than the international standard recommended by the World Health Organization. Results of biochemical analysis of the samples showed that out of 63 confirmed Escherichia coli isolated, 41 (45.5%) were from well water, tap water had 14 (23.3%) while packaged water had 8(13.3%).The susceptibility profile of the isolates to nine antimicrobial agents indicated that majority of the isolates were highly susceptible to Chloramphenicol, Gentamycin, Perrfloxacin, Tarivid, Augmentin, Streptomycin, Sparfloxacin, and Ciprofloxacin, moderate susceptibility to Septrin and resistant to Amoxacilin were observed. None of the water samples met the WHO standards for drinking water and thus pose a serious health risk to its consumers and users if not properly treated.
Key words: Bacteriological quality, Escherichia coli, Prevalence, susceptibility profile, public water sources, Gusau
Global Warming and Technologies for Carbon Capture and Storage
Global concern about climate change caused by anthropogenic activities,
such as the large scale use of fossil fuels as major energy sources for
domestic and industrial application, which on combustion give off
carbon dioxide (CO2) into the atmosphere. Deforestation is also
reducing one of the natural sinks for CO2. These anthropogenic
activities have led to an increase in the concentration of CO2 in the
atmosphere and have thus resulted in the warming of the earth\u2019s
surface (Global Warming), droughts, melting of ice caps, and loss of
coral reefs. Carbon capture and storage (CCS) and other variety of
emerging technologies and methods have been developed. These
technologies and methods are reviewed in this article
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