The biodiversity-productivity relationship (BPR) is foundational to our understanding of the global extinction crisis and its impacts on ecosystem functioning. Understanding BPR is critical for the accurate valuation and effective conservation of biodiversity. Using ground-sourced data from 777,126 permanent plots, spanning 44 countries and most terrestrial biomes, we reveal a globally consistent positive concave-down BPR, showing that continued biodiversity loss would result in an accelerating decline in forest productivity worldwide. The value of biodiversity in maintaining commercial forest productivity alone-US$166 billion to 490 billion per year according to our estimation-is more than twice what it would cost to implement effective global conservation. This highlights the need for a worldwide reassessment of biodiversity values, forest management strategies, and conservation priorities.
Pulse-echo ultrasonometry can be used as a pre-screen for hip osteoporosis before dual-energy x-ray absorptiometry (DXA), potentially allowing DXA to be avoided for the majority of post-menopausal women. Pulse-echo ultrasound measures of tibia cortical thickness are also associated with radiographically confirmed prior fractures, independent of femoral neck bone mineral density.
To estimate how well a pulse-echo ultrasound device discriminates those who have from those who do not have hip osteoporosis (femoral neck bone mineral density [BMD] or total hip BMD T-score ≤ -2.5), and to estimate the association of pulse-echo ultrasound measures with prevalent (radiographically confirmed) clinical fractures.
Five hundred fifty-five post-menopausal women age 50 to 89 had femoral neck and total hip BMD measured by dual-energy x-ray absorptiometry (DXA), and pulse-echo ultrasound measures of distal radius, proximal tibia, distal tibia cortical thickness, and multi- and single-site density indices (DI). Using previously published threshold ultrasound values, we estimated the proportion of women who would avoid a follow-up DXA after pulse-echo ultrasonometry, and the sensitivity and specificity of this for the detection of hip osteoporosis. Logistic regression models were used to estimate the associations of pulse-echo ultrasound measures with radiographically confirmed clinical fractures within the prior 5 years.
Using multi-site and single-site DI measures, follow-up DXA could be avoided for 73 and 69 % of individuals, respectively, while detecting hip osteoporosis with 80-82 % sensitivity and 81 % specificity. Radiographically confirmed prior fracture was associated with ultrasound measures of single-site DI (odds ratio (OR) 1.55, 95 % confidence interval (CI). 1.06 to 2.26) and proximal tibia cortical thickness (OR 1.47, 95 % CI 1.10 to 1.96), adjusted for age, body mass index, and femoral neck BMD.
Pulse-echo ultrasonometry can be used as an initial screening test for hip osteoporosis. Prospective studies of how well pulse-echo ultrasound measures predict subsequent clinical fractures are warranted.