Age-related bone loss and fracture risk: A stochastic model

AbstractA stochastic model of age-related bone loss capable of predicting age-specific incidence of fractures has been implemented by Monte Carlo simulation. Each simulation involves ageing a large cohort of individuals from 20 to 100 years. Every individual is randomly allocated a particular amount of bone as a young adult, an age of onset of bone loss, and parameter values which determine the subsequent loss. Fracture risk is assumed to be zero when the amount of bone is above a global threshold level, increasing progressively as the amount of bone falls below the threshold. From the individual fracture risks, a fracture subpopulation is identified and age-specific incidence evaluated numerically. By adjusting the model parameters, predicted and observed incidence of femoral neck fractures can be closely matched in both sexes using a linear function to describe age-related bone loss. For the fracture of the distal radius, a close match can be achieved in females using an exponential function to describe the bone loss phase; in males, the incidence is independent of age and trauma, rather than the amount of bone in the forearm, appears to be the main determinant of fracture risk

State of Land in the Mekong Region

The Mekong region is in the midst of profound social and environmental change. Despite rapid urbanization, the region remains predominantly rural with more than 60 percent of its population living in rural areas, the vast majority of whom are engaged in agriculture. This population not only continues to grow, but is also disproportionately poor and reliant on land and forest resources. Due to the rapid growth of its agricultural sector, the Mekong region has become a global centre of production and trade for commodities such as rubber, rice, cassava, wood, sugar cane and oil palm. While accelerated flows of global investment and the trade of land-intensive commodities have contributed to growing GDP and the enrichment of some societal actors, outcomes have been highly unequal. The benefits of development have largely accrued to the urban elite, while costs have largely been borne by the rural poor, transforming rural land relations and presenting new insecurities for land tenure. The Mekong region may be at a tipping-point, and transformational change is imperative to sustainably address the needs of agricultural smallholders. Data and information are urgently needed to understand these changes, to inform more equitable and innovative decision-making, and to monitor the outcomes of these decisions. The State of Land in the Mekong Region thus brings together key data and information on current status and trajectories of change with regard to land resources, their social distribution, and the conditions of governance that shape them.1s