Feasibility of reconstructing the glenohumeral center of rotation with a single camera setup

Background: An accurate estimation of the glenohumeral joint center of rotation (CoR) is important during alignment of braces and exoskeletons, as a misalignment will introduce undesired forces on the human body. The aim of this research was to develop a new method to estimate the glenohumeral CoR and register the location to the body using a single camera and two printed markers. Methods: During shoulder anteflexion, the arm roughly describes an arc in the sagittal plane, with the glenohumeral joint in the center. Two binary square-fiducial ArUco markers were secured to the upper arm and the scapula, their position and orientation were obtained, and a sphere was fitted to the coordinates of the arm marker. The sphere center position was then registered on the skin. The accuracy was assessed with a test bench with a known rotational center. The repeatability was assessed in vivo with five healthy participants. Results: The mean absolute offset between the true CoR of the test bench and the fitted sphere centers across multiple trials was 2.7 mm at a velocity of 30 degrees/s, and 2.5 mm at 60 degrees/s. The root mean squared distance from the estimated sphere centers after each trial to the mean sphere center across all trials per participant was 5.1 mm on average for the novice examiner and 5.2 mm for the expert examiner. Conclusions: The proposed method is able to accurately and precisely estimate the glenohumeral CoR

National Vacancy Rates and the Persistence of Shocks in U.S. Office Markets

In this paper, we develop and estimate a model that decomposes the variance in office vacancy rates into market-specific, time-specific, and random components. The results indicate significant differences in natural vacancy rates across markets. We also find some persistence in deviations from these natural vacancy rates. The analysis is applied to both central business district (CBD) and suburban office markets. We find that natural vacancy rates differ across CBD markets and across suburban markets. Further, the persistence of disequilibrium in one CBD market seems to differ significantly from that in another. This is not shown to be true for suburban markets. Copyright American Real Estate and Urban Economics Association.

New developments in classical microscopy; what can be expected for the official control?

The official control of animal proteins in feed is focused on the prevention of Bovine Spongiform Encephalopathy (mad cow disease). The current legislation of the European Union is planned to avoid the feeding of animal by-products to the same species as its origin (ban of cannibalism, or species-to-species ban). With respect to the official control, the circumscription of the term species in legislation should be defined, and species-specific markers should be available. Markers will include primer sets, antibodies, near-infrared profiles or visual characteristics. The method of classical light microscopy is currently the only accepted method in the framework of the official detection of animal proteins. Besides the necessary development of complementary methods, either as stand alone methods or in combination, the visual characteristics used for a microscopic examination of meat and bone meal particles should be fully explored. Multivariate analysis of a range of characteristics of lacunae in bone fragments revealed that discrimination is possible between mammalian and avian bone fragments. Translation to features for every day practical use should be carried out very carefully, and only comprehensively collected information on a range of features will give a first indication of the source. Characteristics of hairs and feather filaments can be used to identify the origin of animal particles. An in situ identification method has been developed for antibody conjugation with troponin I in muscle fibers on a microscopic slide. A proof of principle is presented. Interlaboratory transferability and validation have still to be achieved. The development and testing of light microscopy markers in the framework of the SAFEED-PAP project revealed that a fine tuning of existing microscopic characteristics appears to be possible. Keywords. Microscopic method, feed, marker, hair, feather, bone, meat and bone meal

Office Building Investment and the Macroeconomy: Empirical Evidence, 1973-1985

Given the recent concern about overbuilding in the office sector, this paper considers the influence that macroeconomic factors have upon office construction. Because office construction is volatile and because the "time to build" problem requires construction to change with a lag, the paper employs a different methodology, vector autoregressions, to model the office building sector. The findings indicate that anticipated output has a large and direct effect. This effect depends on the predictive content of nominal interest rates, suggesting that the declines in nominal rates over the past five years explains the recent overbuilding. Copyright American Real Estate and Urban Economics Association.