Systemic transformative adaptation towards urban economic resilience

The socioeconomic impacts of the Covid-19 pandemic are likely to increase further across economies. There is increasing apprehension on the status of rail transport infrastructure megaprojects which are already complex and face many uncertainties and it is imperative to initiate a restoration coupled with support to be implemented in a timely manner. Investors continue to invest in rail megaprojects that run high risks of being over-scheduled and over-budgeted, which has raised the need to improve rail megaporjects and their investments in order to establish the economic base of any society. Hence it is vital to analyse the systemic risks in rail megaprojects given their complexity and uncertainty towards developing an efficient risk management framework. To improve the performance of the procurement of rail megaprojects, the present study conducts a detailed literature review to explore the key procurement risk indicators and critical success factors for public procurement of rail megaprojects. The key findings are used to develop an integrated approach towards a systemic transformative adaptation to enable the effective incorporation of the procurement risk management process into the planning and decision-making of rail megaprojects in the UK. This study develops a conceptual framework that indicates that one of the most critical enablers of improvement in the performance of procurement of rail megaprojects is by enabling a collaborative approach. This is a unique study that presents key procurement risk indicators and critical success factors to derive sustainability based enablers to improve the performance of the procurement process of rail megaprojects

What is the Brillouin Zone of an Anisotropic Photonic Crystal?

The concept of the Brillouin zone (BZ) in relation to a photonic crystal fabricated in an optically anisotropic material is explored both experimentally and theoretically. In experiment, we used femtosecond laser pulses to excite THz polaritons and image their propagation in lithium niobate and lithium tantalate photonic crystal (PhC) slabs. We directly measured the dispersion relation inside PhCs and observed that the lowest bandgap expected to form at the BZ boundary forms inside the BZ in the anisotropic lithium niobate PhC. Our analysis shows that in an anisotropic material the BZ - defined as the Wigner-Seitz cell in the reciprocal lattice - is no longer bounded by Bragg planes and thus does not conform to the original definition of the BZ by Brillouin. We construct an alternative Brillouin zone defined by Bragg planes and show its utility in identifying features of the dispersion bands. We show that for an anisotropic 2D PhC without dispersion, the Bragg plane BZ can be constructed by applying the Wigner-Seitz method to a stretched or compressed reciprocal lattice. We also show that in the presence of the dispersion in the underlying material or in a slab waveguide, the Bragg planes are generally represented by curved surfaces rather than planes. The concept of constructing a BZ with Bragg planes should prove useful in understanding the formation of dispersion bands in anisotropic PhCs and in selectively tailoring their optical properties.Comment: 9 pages, 6 figure

Rice Fields Chemical and Physical Properties and the Implications on Breeding Strategie

Soil related constraints are major limiting factors in crop production in the Sahel. The objective of this study was to assess the properties of farmer's fields soil and irrigation water in Niger and the implications in rice improvement. Composite soil samples were collected from irrigated and non-irrigated fields. Sample of irrigation water was also collected. Physical and chemical analyses were performed in the laboratory. The results showed that most of rice fields were clayey and the non irrigated ones were mostly sandy. The soils were acidic and saline, the electrical conductivity ranged from 2.2 to 16.5 decisiemens per meter. The T-test showed that total dissolved salt, sodium adsorption ratio, cation exchange capacity, and organic matter percentage were significantly higher in irrigated fields than non-irrigated fields. The irrigated soils pH varied from 3.2 to 6.8, the electrical conductivity was greater than 4, and the sodium adsorption ratio was below 13 while the exchangeable sodium percentage was below 15. The irrigation water samples varied in term of ion content from site to site. The total sodium quantity estimated to be deposited varied from 87 kg/ha/year to 218 kg/ha/year. Rice fields' soils are saline and are getting worsened by irrigation water that contains salt. Therefore, the development of rice varieties that could withstand osmotic and ionic salt stress is necessary for sustainable production in the Sahel ecozone

The Growth Performance of Triplochiton scleroxylon, Terminalia superba and Ceiba pentandra in Pure and Mixed Stands.

Plantation developers mostly prefer exotic to indigenous tree species in restoration of degraded forests due, perhaps to, inadequate information on indigenous tree plantations to enable them change in that direction. The study was conducted at the Jimira Forest Reserve in the Nkawie Forest District to compare the growth performance of Ceiba pentandra, Terminalia superba and Triplochiton scleroxylonin their pure and mixed stands. Four plots, each divided into four subplots measuring 50m x 50m, of one hectare demarcated represented three pure stands of Ceiba pentandra, Terminalia superba and Triplochiton scleroxylon and one mixed stand of the three species. Simple random sampling was used to a subplot from each plotand diameter and height measurements were taken. The mean growth rates in diameter of Ceiba pentandra, Terminalia superba, and Triplochiton scleroxylon in the pure stands and the mixed stand were 1.73 and 1.61cm/year; 1.77 and 2.02 cm/year; and 2.70 and 2.57 cm/year respectively and those in height were 1.06 and 0.80 m/year; 1.16 and 1.25 m/year; and 1.98 and 1.59 m/year respectively. The statistical analysis carried out to determine the variations in tree diameter and height in the pure and mixed stands indicated no significant differences. Keywords: Growth Performance, Triplochiton scleroxylon, Terminalia superba, Ceiba pentandra, Pure and Mixed Stands. DOI: 10.7176/JNSR/9-4-0

Socioeconomic inequalities in maternal health care utilization in Ghana

BACKGROUND: Improving maternal and child health remains a public health priority in Ghana. Despite efforts made towards universal coverage, there are still challenges with access to and utilization of maternal health care. This study examined socioeconomic inequalities in maternal health care utilization related to pregnancy and identified factors that account for these inequalities. METHODS: We used data from three rounds of the Ghana Demographic and Health Surveys (2003, 2008 and 2014). Two health care utilization measures were used; (i) four or more antenatal care (ANC) visits and (ii) delivery by trained attendants (DTA). We first constructed the concentration curve (CC) and estimated concentration indices (CI) to examine the trend in inequality. Secondly, the CI was decomposed to estimate the contribution of various factors to inequality in these outcomes. RESULTS: The CCs show that utilization of at least four ANC visits and DTA were concentrated among women from wealthier households. However, the trends show the levels of inequality decreased in 2014. The CI of at least four ANC visits was 0.30 in 2003 and 0.18 in 2014. Similarly, the CIs for DTA was 0.60 in 2003 and 0.42 in 2014. The decomposition results show that access to National Health Insurance Scheme (NHIS) and women's education levels were the most important contributors to the reduction in inequality in maternal health care utilization. CONCLUSIONS: The findings highlight the importance of the NHIS and formal education in bridging the socioeconomic gap in maternal health care utilization

Adaptive strategies of smallholder farming systems to changing climate conditions in the vicinity of Kogyae Strict Nature Reserve within the Forest-Savanna Transitional Zone of Ghana

The strong climate linkages to farming systems render them and dependent communities vulnerable to climate change and variability. Knowledge of existing responses to climate change is important for the formulation of policies and adaptive strategies for resilience. The paper examines a fifty-year climatic record from 1961-2011, community perceptions, experiences and knowledge for evidence of climate change and impacts. Climate change-driven farmer adaptive responses were critically examined relative to farming practices; and crop climatic requirements for growth, development, maturity and harvesting. A mixed methodological approach was adopted to address issues of climate change, exposures, sensitivities and adaptive responses. The results showed that the area has experienced a steady rise in temperature, reduced rainfall amounts of 3.0mm per annum, reducing events of rainfall excesses and increasing deficits, narrowing of rainfall period and a shift of the double to a single rainfall maxima regime. Farmers have observed these patterns of changes and experienced the impacts. Consequently, evidence-driven adaptive responses in the transformation of farming practices, timing of cultivation and choice of crops have been developed by farmers. It is recommended that further adaptive strategies be planned to improve farmers’ adaptive capacities and reduce sensitivity of crops to climate perturbations

Linking Optical SPOT and Unmanned Aerial Vehicle data for a rapid biomass estimation in a Forest-savanna Transitional Zone of Ghana

The direct estimation of biomass using remote sensing technologies, such as LiDAR, RaDAR and Stereo Data is limited in utility, since it does not allow for historical analysis of biomass dynamics far back in time due to their recency in development. This study links Unmanned Aerial Vehicle (UAV)-measured tree height and optical SPOT image reflectance in a mathematical model for a quick and less expensive indirect biomass estimation, and the possibility of historical analysis using the earliest captured optical data. SPOT 6/7 images were used to map land-use/cover patterns. A Phantom 4 drone images were used for height and crown width estimation. A stepwise regression analysis was conducted to establish a relationship between SPOT 6/7 channels and the UAV-generated tree heights. The linear model was used to convert the reflectance values of SPOT images into tree heights, and in turn used for crown width estimation. The estimated tree height and crown width images were used to estimate biomass using an allometric equation. There was no statistically significant difference between UAV and manual tree height measurements. UAV-estimated tree height predicted 88.0% of crown width. Regressing the tree height on the SPOT bands yielded an R2 of 66.0%. It is recommended that further studies be conducted to improve on the accuracy of estimation. It is hoped this would facilitate a quick biomass estimation and long term historical dynamics

Nematodes and Weeds Control Effects of Pueraria phaseoloides and Flemingia macrophylla Fallows on Establishment, Survival and Yield of Plantain

The yield of plantain (Musa spp., AAB Simmonds) declines sharply after 1–2 years of cropping in West and Central Africa, due mainly to weeds and nematodes. A trial was carried out from January 2002 to October 2005 under two land-use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena odorata (L.) R. M. King & H. Rob, and a 20 year-old secondary forest, in three villages in southern Cameroon, to assess the effectiveness of Pueraria phaseoloides and Flemingia macrophylla as planted fallows for weed suppression and reduction in nematode damage of the plantain root system, and determine the yield response of different plantain sucker types to the weed suppression and reduced nematode damage. In each LUS, the treatments were a factorial combination of three levels of fallow system and four levels of plantain sucker type arranged in a randomised complete block design. Total above-ground biomass production of P. phaseoloides was 7.45 Mg ha-1, 4.2 times higher than F. macrophylla (1.78 Mg ha-1; P Boiling water-treated “Essong” > Untreated “Essong”. P. phaseoloides produced significantly (P < 0.05) the highest plantain yield. There were no differences between the natural regrowth and F. macrophylla for all the plantain yield parameters. Sanitizing suckers (boiling and nursery-derived) increased actual yield and quantity of edible bunches by 35% and 26%, respectively, compared to the untreated. It was concluded that P. phaseoloides had the greatest positive effect on the growth and yield of plantain

Performance of nine cassava (Manihot esculanta Crantz) clones across three environments

The study was carried out to quantify the genotype × environment interaction (G × E) and to estimate the phenotypic stability by genotype genotype × environment (GGE) biplot of nine cassava clones comprising 5 hybrids, 3 parent checks and 1 improved variety. The study was planted across three different environments; Fumesua, Pokuase and Ejura representing forest, coastal savanna and forest transition zones, respectively. Genotype main effect was significant (P < 0.001) for fresh root yield and dry matter content, G × E interaction effect was significant (P < 0.001) for fresh root yield only and environment main effect was significant (P < 0.01) for only fresh root yield. The most stable clone for fresh root yield with above average performance was La02/026 (hybrid). The high genotype and low environment effects, and the relatively low interaction on dry matter content imply that evaluation and selection can be effectively done in fewer environments to select clones with high performance for the trait whiles fresh root yield requires multiple environments to identify clones with broad and specific adaptation