Comparative Life Cycle Assessment of Mass Timber and Concrete Residential Buildings: A Case Study in China

As the population continues to grow in China’s urban settings, the building sector contributes to increasing levels of greenhouse gas (GHG) emissions. Concrete and steel are the two most common construction materials used in China and account for 60% of the carbon emissions among all building components. Mass timber is recognized as an alternative building material to concrete and steel, characterized by better environmental performance and unique structural features. Nonetheless, research associated with mass timber buildings is still lacking in China. Quantifying the emission mitigation potentials of using mass timber in new buildings can help accelerate associated policy development and provide valuable references for developing more sustainable constructions in China. This study used a life cycle assessment (LCA) approach to compare the environmental impacts of a baseline concrete building and a functionally equivalent timber building that uses cross-laminated timber as the primary material. A cradle-to-gate LCA model was developed based on onsite interviews and surveys collected in China, existing publications, and geography-specific life cycle inventory data. The results show that the timber building achieved a 25% reduction in global warming potential compared to its concrete counterpart. The environmental performance of timber buildings can be further improved through local sourcing, enhanced logistics, and manufacturing optimizations.

Harnessing Public Food Procurement for Sustainable Rural Livelihoods in South Africa through the National School Nutrition Programme: A Qualitative Assessment of Contributions and Challenges

This paper examines how public food procurements contributes to sustainable rural livelihoods through local sourcing of school food, what has become known as ‘home-grown’ school feeding. Specifically, it draws on in-depth interviews to explore the contributions and challenges of using local farmers as suppliers for South Africa’s National School Nutrition Programme (NSNP) using the case of the Eastern Cape Province, the country’s poorest province. The study found that participating schools in rural areas benefit from local sourcing by way of using fresh vegetables in preparing meals thanks to the utilisation of a decentralised catering model in the Eastern Cape Province. Consequently, there is evidence of farmers participating in NSNP food market earning additional income and growing more vegetables on more land in some cases. However, even though the Eastern Cape Province uses a decentralised procurement model, it has no clear-cut programme to optimise the benefits of local sourcing for NSNP. It only ‘encourages’ schools to buy vegetables grown locally. This calls for pragmatism on the side of government to, through creative procurement and initiatives such as the Agri-Parks, use NSNP as a tool for making the South African food system more inclusive, drive down rural poverty and realise sustainable rural development.

Selective sorting of ancestral introgression in maize and teosinte along an elevational cline

While often deleterious, hybridization can also be a key source of genetic variation and pre-adapted haplotypes, enabling rapid evolution and niche expansion. Here we evaluate these opposing selection forces on introgressed ancestry between maize (Zea mays ssp. mays) and its wild teosinte relative, mexicana (Zea mays ssp. mexicana). Introgression from ecologically diverse teosinte may have facilitated maize’s global range expansion, in particular to challenging high elevation regions (> 1500 m). We generated low-coverage genome sequencing data for 348 maize and mexicana individuals to evaluate patterns of introgression in 14 sympatric population pairs, spanning the elevational range of mexicana, a teosinte endemic to the mountains of Mexico. While recent hybrids are commonly observed in sympatric populations and mexicana demonstrates fine-scale local adaptation, we find that the majority of mexicana ancestry tracts introgressed into maize over 1000 generations ago. This mexicana ancestry seems to have maintained much of its diversity and likely came from a common ancestral source, rather than contemporary sympatric populations, resulting in relatively low FST between mexicana ancestry tracts sampled from geographically distant maize populations. Introgressed mexicana ancestry in maize is reduced in lower-recombination rate quintiles of the genome and around domestication genes, consistent with pervasive selection against introgression. However, we also find mexicana ancestry increases across the sampled elevational gradient and that high introgression peaks are most commonly shared among high-elevation maize populations, consistent with introgression from mexicana facilitating adaptation to the highland environment. In the other direction, we find patterns consistent with adaptive and clinal introgression of maize ancestry into sympatric mexicana at many loci across the genome, suggesting that maize also contributes to adaptation in mexicana, especially at the lower end of its elevational range. In sympatric maize, in addition to high introgression regions we find many genomic regions where selection for local adaptation maintains steep gradients in introgressed mexicana ancestry across elevation, including at least two inversions: the well-characterized 14 Mb Inv4m on chromosome 4 and a novel 3 Mb inversion Inv9f surrounding the macrohairless1 locus on chromosome 9. Most outlier loci with high mexicana introgression show no signals of sweeps or local sourcing from sympatric populations and so likely represent ancestral introgression sorted by selection, resulting in correlated but distinct outcomes of introgression in different contemporary maize populations.

Maker—Plastic In, Plastic Out: Circular Economy and Local Production

Recognising the lack of local and economically accessible facilities, technologies, and public engagement in local recycling, the chapter tackles the challenge of introducing Circular Economy to cope with plastic waste in Copenhagen. The need for circular systemic innovation and holistic production models for recycling plastics led to consider how local micro entrepreneurs, SMEs, commercial resellers and citizens can collaborate for a common, sustainable goal. The chapter presents ‘Plastic In, Plastic Out’ (PIPO), a Circular system for local sourcing, recycling and production of sustainable plastic building materials and products.

Integrating the soybean-maize-chicken value chains to attain nutritious diets in Tanzania

In Tanzania, diets are dominated by starchy staple crops such as maize, levels of malnutrition are high and largely attributed to lack of dietary diversity. We employed fuzzy cognitive mapping to understand the current soybean, maize and chicken value chains, to highlight stakeholder relationships and to identify entry points for value chain integration to support nutritious diets in Tanzania. The fuzzy cognitive maps were constructed based on information gathered during household interviews with 569 farming households, followed by a participatory workshop with 54 stakeholders involved in the three value chains. We found that the soybean, maize and chicken value chains were interconnected, particularly at the level of the smallholder farming systems and at processing facilities. Smallholder farming households were part of one or more value chains. Chicken feed is an important entry point for integrating the three value chains, as maize and soybean meal are the main sources of energy and protein for chicken. Unlike maize, the utilization of soybean in chicken feed is limited, mainly due to inadequate quality of processing of soybean grain into meal. As a result, the soybean grain produced by smallholders is mainly exported to neighbouring countries for further processing, and soybean meal is imported at relatively high prices. Enhancing local sourcing and adequate processing of soybean, coupled with strengthening the integration of smallholder farmers with other soybean, maize and chicken value chain actors offers an important opportunity to improve access to nutritious diets for local people. Our method revealed the importance of interlinkages that integrate the value chains into a network within domestic markets.

Cost-benefit analysis as a tool for measuring economic impacts of local food systems: Case study of an institutional sourcing change

Universities continue to expand their local food sourcing, but the impacts of these sourcing changes are ambiguous. Some academics have measured these impacts using input-output analysis methods to track economic indicators that may be of interest to local communities. However, these studies do not capture nonmarket benefits of local food system investments or answer the broader question of whether local sourcing benefits society as a whole, both of which can be addressed using cost-benefit analysis. This paper explores cost-benefit analysis as an additional tool for measuring the economic impacts of local food investments, using a sourcing change by The Ohio State University as a case study. It builds on recent theoretical applied economics literature on the welfare impacts of local food sourcing and sheds light on important trade-offs of local sourcing that institutions and other buyers may want to consider. Employing data provided by Ohio State University Dining Services and the U.S. Department of Agriculture, I use a Monte Carlo simulation approach that accounts for uncertainty and allows for exploration of many scenarios. In more than half of the scenarios, local sourcing yields a net loss to society. However, additional research is needed by economists and others to enable local food system stakeholders to more easily and accurately conduct this work and add cost-benefit analysis to their project evaluation toolkit.

The Impact of the Global Economic Meltdown on the Manufacturing Sector in Nigeria (2005 – 2009)

As several opinions and suggestions were made on the effect of the global economic meltdown on the Nigerian economy, however, few of these studies explored the impact of the crisis on the manufacturing sector of the economy. In this study, the effort is to provide empirical evidence of the impact on the sector. To achieve this, cross-sectional and time-series data were randomly collected from thirty-one (31) quoted firms across different sectors of the manufacturing sector and for a period of five years (2005-2009). A panel model analysis was employed as the estimating technique; it was considered as the most appropriate for the study. The objectives stated in the study were achieved, as the empirical findings revealed that the global economic meltdown had an impact on the Nigerian manufacturing sector. More so, the impact was negative on the sector and on its profitability all through the periods considered, as the impact was more severe in the year 2007. It was also revealed that profitability across the manufacturing firms in Nigeria is time-variant and cross sectionals variant. Finally, a set of policy recommendations were made as a result of the findings, in order to recognize the role of the manufacturing sector as the engine of growth, whose performance is crucial for economic dependency and transformation, these policies are to help in repositioning the sector from the bad state it was before and after the period of global economic crisis to an encouraging state: The sector need to have a strategic framework for industrial development that is domesticated, emphasis should be made on local sourcing of raw materials and technology so as to save guard the economy from the future severe impact of foreign economic shock, Government should ensure tight effective border control, power generation, transmission, and distribution should be improved, bailout funds and adequate credit should be made available. These and others, if carefully implemented, the manufacturing sector will be able to yield a positive result, possible as the driver of the economy by creating wealth, employment generation and economic prosperity.

The Provenance of Middle Jurassic to Cretaceous sediments in the Irish and Celtic Sea Basins: Tectonic and Environmental controls on sediment sourcing

The Jurassic and Cretaceous sedimentary infill of the Irish and Celtic Sea basins is intimately associated with the breakup of the supercontinent Pangea, and the opening of the Atlantic margin. Previous basin studies have constrained tectonism, basin uplift and sediment composition, but sediment provenance and routing have not received detailed consideration. Current hypotheses for basin infill suggest localised sediment sourcing throughout the Jurassic and Cretaceous, despite a dynamic tectonic and paleoenvironmental history spanning more than 100 million years. We present detrital zircon, white mica and apatite geochronology alongside heavy mineral data from five basins. Findings reveal that basin infill derived predominantly from distal sources with lesser periods of local sourcing. We deduce that tectonically induced marine transgression and regression events had a first-order control on distal versus proximal sedimentary sourcing. Additionally, tectonism which uplifted the Fastnet Basin region during the Middle–Late Jurassic recycled basin sediments into the connected Celtic and Irish Sea Basins. Detrital geochronology and heavy mineral evidence support three distinct provenance switches throughout the Jurassic and Cretaceous in these basins. Overall an integrated multi-proxy provenance approach provides novel insights to tectonic and environmental controls on basin infill as demonstrated in the Irish and Celtic Sea Basins.

Evaluation of Construction Materials Cost Reduction Measures in Building Industry in Imo State, Nigeria

Cost reduction measure on construction materials is very critical in the effectiveness of any construction material management. Negligence on this frustrates the integrated effort deployed in cost control of any building project. As the study aims at assessing the impact of some building material cost reduction strategies with regard to their sourcing, applications and designs for affordable houses, field survey research design method and activity sampling involving some of the major building materials were adopted. Data were analyzed using some non parametric tools like likert scale and chi-square to rank the level of effectiveness of the various materials’ cost reduction measures in the industry. It was also used to determine the impact level of the material management on the overall cost of the materials used in the construction of public building in Owerri. Spearman rank correlation coefficient was also used to examine the strength of relationship between the two major sources of the information. Findings in the study reveal that local sourcing of materials is the most significant method of material management in cost reduction. Other methods in their order of significance for cost reduction are quality assurance, economic design and specification, and on-site production of materials. The various percentage cost effects however are found to be significantly dependent on the methods of material management adopted for the materials’ cost reduction in the study. It is therefore recommended that an effective legislative back-up be instituted with a very strong awareness on the need for robust development of local construction material resources, as well as advocate for more practical contact hours on the stressed areas in the appropriate curriculum of the building profession in all the tertiary institutions in Nigeria. Finally, appropriate checklist/indices for check-mating quality assurance on professional personnel and materials schedules; as well as enforcement of ‘buildability’ and maintainability analyses of building projects should be encouraged in the study area.

Selective sorting of ancestral introgression in maize and teosinte along an elevational cline

While often deleterious, hybridization can also be a key source of genetic variation and pre-adapted haplotypes, enabling rapid evolution and niche expansion. Here we evaluate these opposing selection forces on introgressed ancestry between maize (Zea mays ssp. mays), and its wild teosinte relative. Introgression from ecologically diverse teosinte may have facilitated maize’s global range expansion, in particular to challenging high elevation regions (> 1500 m). We generated low-coverage genome sequencing data for 348 maize and mexicana individuals to evaluate patterns of introgression in 14 sympatric population pairs, spanning the elevational range of Zea mays ssp. mexicana, a teosinte endemic to the mountains of Mexico. While recent hybrids are commonly observed in sympatric populations and mexicana demonstrates fine-scale local adaptation, we find that the majority of mexicana ancestry tracts introgressed >1000 generations ago. This mexicana ancestry seems to have maintained much of its diversity and likely came from a common ancestral source, rather than contemporary sympatric populations, resulting in relatively low FST between mexicana ancestry tracts sampled from geographically distant maize populations. Introgressed mexicana ancestry is reduced in lower-recombination rate quintiles of the genome and around domestication genes, consistent with pervasive selection against introgression. However, we also find mexicana ancestry increases across the sampled elevational gradient and that high introgression peaks are most commonly shared among high-elevation maize populations, consistent with introgression from mexicana facilitating adaptation to the highland environment. In the other direction, we find patterns consistent with adaptive and clinal introgression of maize ancestry into sympatric mexicana at many loci across the genome, suggesting that maize also contributes to adaptation in mexicana, especially at the lower end of its elevational range. In sympatric maize, in addition to high introgression regions we find many genomic regions where selection for local adaptation maintains steep gradients in introgressed mexicana ancestry across elevation, including at least two inversions: the well-characterized Inv4m and a new 3 Mb inversion Inv9f surrounding the macrohairless1 locus on chromosome 9. The bulk of our ancestry selection outliers show no signals of sweeps or local sourcing from sympatric populations and so likely represent ancestral introgression sorted by selection, resulting in correlated but distinct outcomes of introgression in different contemporary maize landrace populations.