14,577 research outputs found
Cranial sutures work collectively to distribute strain throughout the reptile skull
The skull is composed of many bones that come together at sutures. These sutures are important sites of growth, and as growth ceases some become fused while others remain patent. Their mechanical behaviour and how they interact with changing form and loadings to ensure balanced craniofacial development is still poorly understood. Early suture fusion often leads to disfiguring syndromes, thus is it imperative that we understand the function of sutures more clearly. By applying advanced engineering modelling techniques, we reveal for the first time that patent sutures generate a more widely distributed, high level of strain throughout the reptile skull. Without patent sutures, large regions of the skull are only subjected to infrequent low-level strains that could weaken the bone and result in abnormal development. Sutures are therefore not only sites of bone growth, but could also be essential for the modulation of strains necessary for normal growth and development in reptiles
Nitrogen additions and litter decomposition: A meta-analysis
We conducted a meta-analysis of previously published empirical studies that have examined the effects of nitrogen (N) enrichment on litter decomposition. Our objective was to provide a synthesis of existing data that comprehensively and quantitatively evaluates how environmental and experimental factors interact with N additions to influence litter mass loss. Nitrogen enrichment, when averaged across all studies, had no statistically significant effect on litter decay. However, we observed significant effects of fertilization rate, site-specific ambient N-deposition level, and litter quality. Litter decomposition was inhibited by N additions when fertilization rates were 2–20 times the anthropogenic N-deposition level, when ambient N deposition was 5–10 kg N·ha^−1·yr^−1, or when litter quality was low (typically high-lignin litters). Decomposition was stimulated at field sites exposed to low ambient N deposition (<5 kg N·ha^−1·yr^−1) and for high-quality (low-lignin) litters. Fertilizer type, litterbag mesh size, and climate did not influence the litter decay response to N additions
Urban streets: generating design options, in Better Streets for Better Cities: A Handbook for Active Street Planning, Design and Management - Chapter 8
Using examples from the MORE cities, this chapter describes and illustrates the process of applying the MORE option generation and co-creation design tools (as introduced in Chapter 5) to develop design options. It also covers post-appraisal stakeholder engagement
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