Objective: The aim of this study was to test whether elderly individuals underestimate the time that it will take them to cross a street by comparing estimated with actual road-crossing time. Background: In many developed countries, elderly people are overrepresented among pedestrian fatalities from motor vehicle accidents. There is surely more than one contributing factor to this phenomenon, and many have been offered. We propose that one additional factor may be that although older people are consciously aware that they no longer walk at the same pace as they once did, they do not take this fact into consideration when planning a street crossing. Method: We compared the ability of young and old pedestrians to estimate the time that it will take them to cross a street, using both prospective and retrospective time estimation. Results: A significant interaction was found between age group and crossing time. Among elderly participants, actual crossing times were significantly longer than both their precrossing estimation and their postcrossing estimation, which did not significantly differ from each other. In contrast, the undergraduate group’s crossing times did not display a significant difference across measurements. Conclusion: This study implies that even if older pedestrians correctly evaluate the road situation, they may nonetheless endanger themselves by underestimating the time that it will take them to cross the street. We suggest that minimizing this effect could be accomplished by educating seniors to the fact that they are not as fast as they once were and that this fact needs to be factored in to street-crossing decisions.

Clean Meat is an emerging technology which promises to revolutionize the global food market. Alongside technological developments, the social impact of this innovation is being explored. Consumer acceptance will depend on multiple factors. For Orthodox Jews, the critical question will be whether the new food can be defined as kosher. In the absence of an exact precedent in Talmudic case law, scholars have begun to examine which set of principles would govern the status of the new meat product. Traditionally, meat is permitted for kosher consumption only when it derives from a kosher species which has been kosher slaughtered in accordance with strict regulations. There is room to suggest that this same set of rules would determine the status of any product derived through cellular agriculture, and thus the source cells would have to be extracted from a kosher species and only after kosher slaughter. Another approach would be to view the process as so different from the traditional growth of meat that it may be defined as kosher, even where traditional meat would not. Three determining factors will be: (1) the source of the original cells from which clean meat will be produced (animal species and cell type), (2) the nature of the growth medium, and (3) the exact nature of the process involved, which will determine whether the final product is considered a “new entity” or merely an “inheritance” of the starter cells. An authoritative ruling must be based on an in-depth appreciation of the scientific methods involved.

A primary task of the eye care professional is determining the refraction, or optical correction, of a patient. The duochrome red-green test is a standard tool for verification of the final refraction. Traditionally, it is recommended for use both prior to and subsequent to determining the cylindrical or astigmatic component of the refraction. In order for it to be effective when used before correcting the cylinder it is necessary that the COLC (Circle of Least Confusion) be on the retina. This study examined whether it is necessarily true that the duochrome response in uncorrected astigmatism will be as trust-worthy as it is with corrected cylinders. The red-green examination was performed monocularly under the following three conditions: a. fully corrected refraction for the subgroup of eyes that had spherical refractions and for the subgroup of eyes with sphero-cylindrical refractions. b. best sphere-only correction without cylinder correction in sphero-cylindrical eyes c. an induced cylinder error in spherical eyes. The interval between the last “red” response and the first “green” response for the right eyes as a group and separately for the physiological cylinder and induced cylinder correction sub-groups was calculated and compared using a paired, two-tailed t-test. The intervals between “red” and “green” responses were not significantly different in the population as a whole and in the uncorrected physiological cylinder and induced cylinder subgroups examined. Based on the finding that the interval of red-green equality with fully corrected cylinder and without the cylindrical correction are not significantly different, the red-green duochrome test can indeed be used both before and after cylindrical correction.