Distance two labeling of direct product of paths and cycles

Suppose that $[n]=\left\{0,1,2,...,n\right\}$ is a set of non-negative integers and $h,k \in [n]$. The $L(h,k)$-labeling of graph $G$ is the function $l:V(G)\rightarrow[n]$ such that $\left|l(u)-l(v)\right|\geq h$ if the distance $d(u,v)$ between $u$ and $v$ is one and $\left|l(u)-l(v)\right| \geq k$ if the distance $d(u,v)$ is two. Let $L(V(G))=\left\{l(v): v \in V(G)\right\}$ and let $p$ be the maximum value of $L(V(G)).$ Then $p$ is called $\lambda_h^k-$number of $G$ if $p$ is the least possible member of $[n]$ such that $G$ maintains an $L(h,k)-$labeling. In this paper, we establish $\lambda_1^1-$ numbers of $P _m \times C_n$ graphs for all $m \geq 2$ and $n\geq 3$.Comment: 13 pages, 9 figure

Perceived bitterness character of beer in relation to hop variety and the impact of hop aroma

The impact of hop variety and hop aroma on perceived beer bitterness intensity and character was investigated using analytical and sensory methods. Beers made from malt extract were hopped with 3 distinctive hop varieties (Hersbrucker, East Kent Goldings, Zeus) to achieve equi-bitter levels. A trained sensory panel determined the bitterness character profile of each singly-hopped beer using a novel lexicon. Results showed different bitterness character profiles for each beer, with hop aroma also found to change the hop variety-derived bitterness character profiles of the beer. Rank-rating evaluations further showed the significant effect of hop aroma on selected key bitterness character attributes, by increasing perceived harsh and lingering bitterness, astringency, and bitterness intensity via cross-modal flavour interactions. This study advances understanding of the complexity of beer bitterness perception by demonstrating that hop variety selection and hop aroma both impact significantly on the perceived intensity and character of this key sensory attribute

Public Revenue and Fiscal Consolidation in Nigeria

This study seeks to ascertain the relationship between public revenue and expenditure as well as to examine the proportion of revenue and budget deficit that is spent on capital projects in Nigeria. Both descriptive and regression methods were used to analyze time series data covering a period of thirty-one years. The regression model was well-fitted and all the explanatory variables were significant in explaining the dependent variable, government revenue. Findings reveal that a positive relationship exists between public revenue and expenditure and that Nigerian government has not been spending enough funds on capital projects. The study therefore recommended that public spending should be more on capital projects. There should be government intervention in the provision of public goods and in the regulation of private investors’ operation. Monetary policies which would lead to increase in money supply and favourable exchange rate should be put in place. Keywords: public revenue, public expenditure, budget deficit, capital projects, public goods, monetary policie

Transcriptome profiling and gene editing for biofortification of cassava

Cassava (Manihot esculenta Crantz) is an important food crop for millions of people in sub- Saharan Africa. Cassava serves as a food security crop and a good source of energy, but it has relatively low nutritional quality, which has nutritional implications for those who rely on the crop as their main source of calorie intake. Vitamin A deficiency (VAD) is a health problem in populations whose diet constitutes mainly starchy crops like cassava. A possible solution is biofortification by conventional breeding or biotechnology to increase β-carotene content. Unfortunately, some studies report a negative correlation between β-carotene and dry matter content in certain genotypes, which could pose a challenge to these types of cassava biofortification measures. Field-grown cassava landraces were analyzed for agronomic traits and carried out specific and global transcript analyses by real-time quantitative RT-PCR and RNA-sequencing (RNA-seq). This was combined with targeted starch and carotenoids analysis by HPLC and non-targeted metabolite analysis by GC/LC-MS to understand the regulation of key enzymes and intermediate metabolites to identify genes influencing β- carotene accumulation in cassava. Also, using the CRISPR/Cas9-mediated gene editing system in the cassava cultivar TMS60444 we tried to introduce knockout mutations into cassava β-carotene hydroxylase (MeChyβ), lycopene-ε-cyclase (MeLcyε), and 9- cisepoxycarotenoid dioxygenase 1 (MeNced1) which are key genes of the carotenoid pathway. In a separate study, the biosafety regulations and policies in Kenya, Nigeria, Uganda, and the EU represented by Sweden were examined by comparing legislative texts and conducting interviews to determine if policy and regulatory frameworks present problems to perform R&D using new breeding technologies. In the cassava landraces analyzed, we found a weak negative correlation between starch and β-carotene content, whereas there was a strong positive correlation between root yield and carotenoids. Also, cassava landraces with reasonably high content of starch and β-carotene were identified that could be candidates for biofortification by further breeding or plant biotechnological means. Global gene expression profiles grouped cassava landraces into white and yellow landraces; however, at the same time there was no general correlation between the expression profiles of individual genes involved in carotenoid synthesis and accumulation with the storage root color. Gene Ontology (GO) enrichment showed over-representation of upregulated genes involved in protein-related metabolic and catabolic processes in yellow landraces while GO related to photosynthesis and light reactions were enriched in white landraces. Interestingly, we identified a previously reported amino acid change from Alanine to Aspartic acid in MePsy1 at position 191 to distinguish the yellow lines from the white lines; however, this change was absent in the paleyellow lines, confirming that the mutation in psy is not solely responsible for carotenoid accumulation in cassava. Non-targeted metabolite analysis revealed higher abundance of several amino acids in white lines, but also higher levels of a few osmolytes indicating differences in stress response. Transformation of cassava FECs with gene targets Lcyε, and Nced1 did not produce transgenic regenerated shoots, whereas MeChyβ produced in vitro plantlets still under investigation. Finally, our study showed that biosafety regulations on GMO approval in Kenya, Nigeria, and Uganda are not a major hurdle for R&D but might rather be influenced by factors outside of the regulatory framework such as perceptual and financial factors including funding opportunities

Effects of incorporating polycaprolactone and flax fiber into glycerol-plasticized pea starch

The environmental menace associated with the existing eco-unfriendly conventional plastics prompted the exploration of natural polymers such as starch for the development of biodegradable plastics. These efforts have seen starch used in various ways, one of which is in the processing of thermoplastic starch (TPS). Thermoplastic starch (also known as plasticized starch) is the product of the interaction between starch and a plasticizer in the presence of thermomechanical energy. While starch blends with conventional plastics only yield products that biofragment, thermoplastic starch (TPS) offers a completely biodegradable option. However, it is limited in application due to its weak mechanical strength and poor moisture resistance. To this end, the objective of this study was to determine the effects of incorporating polycaprolactone (PCL) and flax fiber into glycerol-plasticized pea starch. The effects of processing moisture content on the physical properties of glycerol-plasticized pea starch were also evaluated. The physical properties investigated included morphology, tensile properties, moisture absorption, and thermal properties. Accordingly, two thermoplastic pea starch mixtures containing 9.3 and 20% processing moisture contents were prepared while maintaining starch (pea starch) and glycerol in ratio 7:3 by weight (dry basis). Polycaprolactone was then compounded at 0, 10, 20, 30, and 40% by weight in the solid phase with the TPS mixtures to determine the effects of processing moisture content and PCL incorporation on the physical properties of glycerol-plasticized pea starch. This experiment was structured as a 2 x 5 factorial completely randomized design at 5% level of significance. Subsequently, PCL and flax fiber were compounded with the TPS mixture containing 20% processing moisture to determine the effects of PCL (0, 20, and 40% wt) and flax fiber (0, 5, 10, and 15% wt) incorporation on the physical properties of glycerol-plasticized pea starch. This was structured as a 3 x 4 factorial completely randomized design at 5% level of significance. All the samples were compressed at 140°C for 45 min under 25000-kg load. The compression-molded samples were characterized using scanning electron microscopy (SEM), tensile test, moisture absorption test, and differential scanning calorimetry (DSC) techniques. The tensile fracture surfaces showed a moisture-induced fundamental morphological difference between the two TPSs. The TPS prepared at 20% processing moisture content revealed complete starch gelatinization, thus, exhibiting a rather continuous phase whereas the TPS prepared at 9.3% processing moisture content revealed instances of ungelatinized and partly gelatinized pea starch granules. Consequently, the tensile strength, yield strength, Young’s modulus, and elongation at break increased by 208.6, 602.6, 208.5, and 292.0%, respectively at 20% processing moisture content. The incorporation of PCL reduced the degree of starch gelatinization by interfering with moisture migration during compression molding due to its (PCL) hydrophobicity. At both processing moisture levels of 9.3 and 20%, PCL incorporation had significant impacts on the tensile properties of the plasticized pea starch. Flax fiber incorporation also increased the tensile strength, yield strength, and Young’s modulus while concomitantly reducing the elongation at break of the plasticized pea starch. In the TPS/PCL/flax fiber ternary composites, both PCL and flax fiber improved the tensile strength by acting as independent reinforcing materials as no PCL-fiber interfacial bonding was observed. Maximum tensile strength of 11.55 MPa was reached at 10% flax fiber and 40% PCL reinforcement. While the PCL-TPS interfacial interaction was poor, some degree of TPS-flax fiber interfacial bonding was noticed due to their chemical similarity. TPS prepared at 20% moisture showed more moisture affinity than that prepared at 9.3% moisture. The moisture absorption of TPS dropped progressively with the addition of hydrophobic PCL. Fiber incorporation also reduced moisture absorption by the plasticized pea starch. PCL-fiber incorporation also yielded improved moisture resistance vis-à-vis pure TPS. Finally, the TPS processed at 9.3% moisture exhibited higher thermal stability than that processed at 20%. Individual components of the composites retained their respective thermal properties, thus, implying thermodynamic immiscibility

Socio-Environmental Effects of Nigerian National Petroleum Corporation Depot, Apata, Ibadan on the Adjoining Neighbourhoods

Nigeria, one of the major crude oil producing countries in the world, transports petroleum products through pipelines to several oil depots located across the country from where it is trucked to end users. Activities within these depots are known to have impact on their immediate environment due to the nature of operations and the externalities generated. This paper therefore examined the socio-environmental effects of the Nigerian National Petroleum Depot, Apata, Ibadan on its immediate neighbourhood. A case study approach utilising primary and secondary data collection was adopted in which 205 residential buildings and respondents were proportionally selected for sampling from four neighbourhoods within 500 metres radius of the facility. An environmental audit including ground water samples were randomly collected for testing and analysis from Adebisi stream and residential hand-dug wells. Findings revealed local access road incapacitation emanating from indiscriminate parking of fuel tankers and spiralling into constant traffic congestion on major roads. Desludging of fuel storage tanks (79.5%) resulting into regular effluent discharge into the Adebisi stream and fume emission (62.6%), were attested to by residents. Water quality analysis revealed a high concentration of lead (pb.0.06mg/l) above the maximum permissible limit of (0.01mg/l) for potable water. Other detected metals, Cadmium (0.003mg/l), Copper (0.006mg/l) and Zinc (3.0 mg/l) were all within the appropriate recommended limits. The study recommended a periodic environmental audit and regular dialogue with stakeholders of the host communities for socio-environmental sustainability