This article presents the first attempt to construct a computational model of common ground. Four corpus-based metrics are presented that estimate what facts are likely to be in common ground. The proposed metrics were evaluated in an experiment with human participants, focussing on a domain of famous people. The results are encouraging: two of the proposed metrics achieved a large positive cor...

SEPTEMBER 2010 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 35 T he introduction of wavefront-sensing techniques to ophthalmology has redefined the clinical meaning of refractive error. Now, all imperfections in the components and materials within the eye that cause light rays to deviate from their desired path are referred to as optical aberrations. Lower-order aberrations (defocus and astigmati...

In most developing countries children provide some form of insurance against risks when parents are old, which, in turn, justifies parental preference to have more children. In this paper, we examine the causal effect of number of children on several measures of health status of elderly parents using newly available China Health and Retirement Survey data. Because number of children in a family...

When populations occur in ephemeral patches, such as treefall gaps, rapid changes in patch quality may affect colonization processes. I asked what effect patch quality dynamics and propagule dispersal would have on colonization by Passiflora vines that establish in canopy gaps in lowland rainforests of Corcovado National Park, Costa Rica. Passiflora vine recruitment required high patch quality,...

Computation of document image quality metrics often depends upon the availability of a ground truth image corresponding to the document. This limits the applicability of quality metrics in applications such as hyperparameter optimization of image processing algorithms that operate on-the-fly on unseen documents. This work proposes the use of surrogate models to learn the behavior of a given doc...

BACKGROUND The Janzen-Connell hypothesis proposes that seed and seedling enemies play a major role in maintaining high levels of tree diversity in tropical forests. However, human disturbance may alter guilds of seed predators including their body size distribution. These changes have the potential to affect seedling survival in logged forest and may alter forest composition and diversity. ME...

As a multiple function tree species, Cyclocarya paliurus (Batal) Iljinskaja is mainly planted and managed for timber production and medical use. To improve the seed use efficiency and outplanting performance of C. paliurus, the effects of container types and growth medium on the seedling growth and root morphology of C. paliurus were investigated by using a completely randomized block experimen...

We measured net photosynthesis, leaf conductance, xylem water potential, and growth of Pinus strobus L. seedlings two years after planting on two clear-cut and burned sites in the southern Appalachians. Multiple regression analysis was used to relate seedling net photosynthesis to vapor pressure deficit, seedling crown temperature, photosynthetically active radiation (PAR), needle N, xylem wate...