Bounding Global Aerosol Radiative Forcing of Climate Change.

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m-2, or -2.0 to -0.4 W m-2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds.

Oral health in Israel--a review of surveys over several decades.

This review covers oral health surveys carried out in various communities in Israel over four decades. The general trends were for increasing caries prevalence from early surveys in the 1950s and 1960s up to the 1980s as evidenced by the rising DMFT. Treatment levels had increased since the 1980s, and there is a national decrease in caries experience. But there were still some communities and social groups with levels of untreated caries and other treatment needs. There is a continued need for strengthened oral health promotion and other preventive oral health measures at a community and public health level.

The instantaneous centre of rotation of a fixed unilateral distal extension partial denture.

A photographic technique was used to determine the instantaneous centre of rotation of a fixed unilateral distal extension partial denture and the teeth to which it was attached. The teeth involved were the lower canine and first premolar. When the two crowns were splinted together to provide support, both vertical and lateral saddle movement was reduced. Saddle support using only the first premolar produced a centre of rotation in the sagittal plane below the canine crown--which became located anterior to the canine when the two supporting teeth were splinted together. In the coronal plane, canine support produced an axis of rotation buccal to, and outside the confines of, the model; splinting of the canine and first premolar caused the centre of rotation in this plane to be located buccally and superior to the abutment tooth roots. The more posteriorly the saddle was loaded, the greater was the magnitude of the resultant movement.

The effect of partial denture design on abutment tooth and saddle movement.

A laboratory investigation designed to simulate the effect of loads applied to a free-end saddle partial denture was carried out. Abutment tooth and also saddle movement were monitored using a photogrammetric method. Loads applied to the denture saddle were transmitted through the occlusal rest and also the clasp components causing movement of both denture saddle and the abutment tooth. The direction of abutment tooth movement was towards the mesial, whether the occlusal rest was situated on the mesial or distal aspect of the tooth crown. It was also evident that the design of the clasp unit used affects the magnitude and direction of abutment tooth movement.

The effect of variation of residual ridge angle on partial denture abutment tooth movement.

Using a laboratory model simulating a free-end saddle partial denture situation, the effect of variation of the angulation of the crest of the residual alveolar ridge to the horizontal on movement of the abutment tooth and saddle was observed. It was found that the inclination of the residual ridge affected the direction and magnitude of abutment tooth movement. The direction of abutment tooth movement was not related to the position of the occlusal rest. However, the magnitude of saddle and abutment tooth movement is affected by the design of the clasp used.