According to the authors, time-modified confounding occurs when the causal relation between a time-fixed or time-varying confounder and the treatment or outcome changes over time. A key difference between previously described time-varying confounding and the proposed time-modified confounding is that, in the former, the values of the confounding variable change over time while, in the latter, t...

Quinoa is recognized as a crop of great value in terms of tolerance to abiotic stresses and there is growing interest to introduce it in marginal agricultural production systems worldwide. Also, quinoa is one of the most nutritious food crops currently known and the nutritive properties of the crop are seen as a mean to fight malnutrition globally. Various quinoa cultivars have been screened fo...

The use of marginal land, especially that which has already been used for agricultural purposes in the past two decades, biomass cultivation is seen as an important approach transition to a sustainable bioeconomy. Marginal land can provide many other ecosystem services than provisioning bioenergy and biobased products such erosion mitigation, groundwater protection nursery promote biodiversity....

where u ∼ N(0, G) and 2 ∼ N(0, R) with u and 2 independent. This model can be interpreted as Y |β, u ∼ N(Xβ+Zu,R), u ∼ N(0, G), yielding (on integrating out u) the marginal model Y |β ∼ N(Xβ,ZGZ + R). Let V = ZGZ + R. Then the maximum penalized likelihood estimates of β and u given G and R are given by θ̂ = [ β̂ û ] = (CTR−1C + B)−1CTR−1y (A.2) where C = [X Z] and B is the block diagonal matrix w...

Longitudinal studies, where data are repeatedly collected on one subject over a period, are common in medical research. When effect of a time-varying exposure on an outcome of interest is measured at different time points, standard statistical methods fail to give robust estimate in the presence of time-dependent confounders. There is alternative method avoid, that is, inverse probability weigh...

A concept known as ‘marginal gains’, an approach to performance improvement in elite sport came to prominence during the London 2012 Olympics when Team GB cycling won a record eight gold medals. Since National Lottery funding was awarded in 1997 to develop British cycling, the ethos of making aggregated small gains in many areas to improve overall performance has been central to its success. Th...

Full terms and conditions of use: http://pubsonline.informs.org/page/terms-and-conditions This article may be used only for the purposes of research, teaching, and/or private study. Commercial use or systematic downloading (by robots or other automatic processes) is prohibited without explicit Publisher approval. For more information, contact [email protected]. The Publisher does not warr...

This paper analyzes conservation and extinction of renewable resources when the production function is nonconcave and the return function depends on consumption and the resource stock. The paper focuses on the efficiency of global conservation, a safe standard of conservation, and extinction. Which outcome obtains depends on the marginal rate of substitution between investment and the stock in ...