Maintenance Requirements of Implant Supported Fixed Prostheses Opposed by Either Implant Supported Fixed Prostheses or Natural Teeth: 5 Years Results

AIM: To compare the maintenance requirements of implant supported fixed prostheses opposed by implant supported fixed prostheses natural teeth or complete dentures. METHOD: The maintenance requirements were obtained by examining the dental records of 15 people, of whom 6 were edentulous in both arches and 9 edentulous in one arch. The results were compared to those obtained from 22 edentulous people in whom implants had been used in the mandible (control group). All the patients were treated with Nobel Biocare implants using standard implant and prosthetic protocols. RESULTS: The main maintenance requirement was the need to repair part of the superstructure. The artificial teeth and the acrylic resin had to be repaired on 44 occasions in the group with implants in both jaws and 14 occasions in the group with implants opposed by natural teeth. This compared with 2 occasions in the control group. Similarly the group with implants in both jaws were more likely to fracture the gold alloy framework, an event which occurred on 6 occasions. The Kruskal- Wallis one way analysis of variance on ranks was used to identify significant differences and Dunn’s method of All Pairwise Multiple Comparison Procedures was used to distinguish which group differed from the other. The group with implants in both jaws was significantly different to the other two groups in relation to the higher incidence of fracture of the teeth and acrylic resin superstructure (p<0.0001) and fracture of the gold alloy framework (p = 0.0002). CONCLUSION: The maintenance requirements of implant supported fixed prostheses opposed by implant supported fixed prostheses are much greater than when opposed by natural teeth or complete dentures

Hiding in plain sight: experimental evidence for birds as selective agents for host mimicry in mistletoes

Many Australian mistletoe species are cryptic, closely resembling their host foliage and overall appearance. Seed-dispersing birds have been proposed as a selective agent for host resemblance, with cryptic mistletoes only located by thoroughly searching through canopies regardless of infection status, boosting mistletoe populations by increasing the frequency of seeds dispersed to uninfected hosts; however, this idea is as yet untested. We measured bird visitation to fruiting mistletoes (n = 20) over two consecutive days, with manual defoliation of the mistletoe occurring before observation began on the second day to determine the effect of the visual appearance of the mistletoe on potential seed-dispersing birds, expecting defoliation to reduce the number of visits. Visits to the mistletoes were compared between days of observation and dietary guild (mistletoe specialist/nonspecialist). Intact mistletoes were visited more than the defoliated mistletoes, and the dietary guilds differed in their visitation patterns. This work demonstrates that the visual acuity of seed-dispersers can distinguish subtle differences in mistletoe phenotypes within infected hosts, consistent with the hypothesis that those mistletoes that more closely resemble their hosts are more difficult to perceive from afar and therefore more likely to have their seeds dispersed to uninfected hosts. </jats:p

ForestHash: Semantic Hashing With Shallow Random Forests and Tiny Convolutional Networks

Hash codes are efficient data representations for coping with the ever growing amounts of data. In this paper, we introduce a random forest semantic hashing scheme that embeds tiny convolutional neural networks (CNN) into shallow random forests, with near-optimal information-theoretic code aggregation among trees. We start with a simple hashing scheme, where random trees in a forest act as hashing functions by setting `1' for the visited tree leaf, and `0' for the rest. We show that traditional random forests fail to generate hashes that preserve the underlying similarity between the trees, rendering the random forests approach to hashing challenging. To address this, we propose to first randomly group arriving classes at each tree split node into two groups, obtaining a significantly simplified two-class classification problem, which can be handled using a light-weight CNN weak learner. Such random class grouping scheme enables code uniqueness by enforcing each class to share its code with different classes in different trees. A non-conventional low-rank loss is further adopted for the CNN weak learners to encourage code consistency by minimizing intra-class variations and maximizing inter-class distance for the two random class groups. Finally, we introduce an information-theoretic approach for aggregating codes of individual trees into a single hash code, producing a near-optimal unique hash for each class. The proposed approach significantly outperforms state-of-the-art hashing methods for image retrieval tasks on large-scale public datasets, while performing at the level of other state-of-the-art image classification techniques while utilizing a more compact and efficient scalable representation. This work proposes a principled and robust procedure to train and deploy in parallel an ensemble of light-weight CNNs, instead of simply going deeper.Comment: Accepted to ECCV 201

The Replication Argument for Incompatibilism

In this paper, I articulate an argument for incompatibilism about moral responsibility and determinism. My argument comes in the form of an extended story, modeled loosely on Peter van Inwagen’s “rollback argument” scenario. I thus call it “the replication argument.” As I aim to bring out, though the argument is inspired by so-called “manipulation” and “original design” arguments, the argument is not a version of either such argument—and plausibly has advantages over both. The result, I believe, is a more convincing incompatibilist argument than those we have considered previously

Mexico City and the biogeochemistry of global urbanization

Mexico City is far advanced in its urban evolution, and cities in currently developing nations may soon follow a similar course. This paper investigates the strengths and weaknesses of infrastructures for the emerging megacities. The major driving force for infrastructure change in Mexico City is concern over air quality. Air chemistry data from recent field campaigns have been used to calculate fluxes in the atmosphere of the Valley of Mexico, for compounds that are important to biogeochemistry including methane (CH4), carbon monoxide (CO), nonmethane hydrocarbons (NMHCs), ammonia (NH3), sulfur dioxide (SO2), nitrogen oxides (NOx and NOy), soot, and dust. Leakage of liquified petroleum gas approached 10% during sampling periods, and automotive pollutant sources in Mexico City were found to match those in developed cities, despite a lower vehicle-to-person ratio of 0.1. Ammonia is released primarily from residential areas, at levels sufficient to titrate pollutant acids into particles across the entire basin. Enhancements of reduced nitrogen and hydrocarbons in the vapor phase skew the distribution of NOy species towards lower average deposition velocities. Partly as a result, downwind nutrient deposition occurs on a similar scale as nitrogen fixation across Central America, and augments marine nitrate upwelling. Dust suspension from unpaved roads and from the bed of Lake Texcoco was found to be comparable to that occurring on the periphery of the Sahara, Arabian, and Gobi deserts. In addition, sodium chloride (NaCl) in the dust may support heterogeneous chlorine oxide (ClOx) chemistry. The insights from our Mexico City analysis have been tentatively applied to the upcoming urbanization of Asia

Pleosporales

One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae