Femoral bone fracture is one of the main causes for the failure of hip arthroplasties (HA). Being subjected to abrupt and high impact forces in daily activities may lead to complex loading configuration such as bending and sideway falls. The objective of this study is to predict the risk of femoral bone fractures in total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). A computed tomography (CT) based on finite element analysis was conducted to demonstrate damage formation in a three dimensional model of HAs. The inhomogeneous model of femoral bone was constructed from a 79 year old female patient with hip osteoarthritis complication. Two different femoral components were modeled with titanium alloy and cobalt chromium and inserted into the femoral bones to present THA and RHA models respectively. The analysis included six configurations, which exhibited various loading and boundary conditions, including axial compression, torsion, lateral bending, stance and two types of falling configurations. The applied hip loadings were normalized to body weight (BW) and accumulated from 1 BW to 3 BW. Predictions of damage formation in the femoral models were discussed as the resulting tensile failure as well as the compressive yielding and failure elements. The results indicate that loading directions can forecast the pattern and location of fractures at varying magnitudes of loading. Lateral bending configuration experienced the highest damage formation in both THA and RHA models. Femoral neck and trochanteric regions were in a common location in the RHA model in most configurations, while the predicted fracture locations in THA differed as per the Vancouver classification.
Many carnivorous mammals consume fruits and disperse the intact seeds to specific sites. Few studies have attempted to quantify this seed dispersal or evaluate its effectiveness, despite its potential importance and functional uniqueness. In the study reported here, we found that a frugivorous carnivore, the common palm civet (Paradoxurus hermaphroditus), generated seed shadows that are distinct from those of the sympatric frugivore, the pig-tailed macaque (Macaca nemestrina), and played a unique and important role in the regeneration of Leea aculeata (Leeaceae). We found that macaques dispersed the seeds randomly, while civets dispersed them non-randomly to sites such as the banks of small rivers, rain-flow paths, abandoned trails, and treefall gaps, which are characterized by low stem density and canopy cover. Seeds of L. aculeata that were dispersed by civets to the banks of rivers and gaps had significantly higher survival and growth rates than those dispersed to rain-flow paths or abandoned trails. Seeds dispersed by macaques or to random locations also had low survival. Although the effects of the civets on seed fate were not straightforward, compared with macaques and random dispersal, civets significantly enhanced the survival and growth of L. aculeata seeds after 1 year. These results indicate that non-random dispersal by civets is important for the persistence of L. aculeata. Civets may disperse other plant species and thus could have profound effects on forest dynamics.
The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.