The results in sixteen patients who had a displaced, comminuted intra-articular fracture of the distal end of the radius and who were treated by open reduction and internal fixation were ...retrospectively reviewed. At a mean follow-up of 4.8 years, 81 per cent of the patients had a rating of good or excellent by the scoring system of Gartland and Werley, but only 56 per cent had such a rating when the modified scoring system of Green and O'Brien was used. All of the fractures healed at an average of nine weeks. A step-off of two millimeters or more in the distal radial articular surface at the time of healing was important, because the four patients in whom the fracture healed with this amount of incongruity all had post-traumatic arthritis at follow-up, compared with only three of twelve in whom the incongruity was less than two millimeters.
Using a large sample of limit orders on NYSE stocks, we find that investors submit more limit orders with even-eighth prices than odd-eight prices. However, even though there are a greater number of ...even-eighth limit orders, the proportion of executing limit orders submitted with even prices is greater than those submitted with odd prices for a large portion of our sample. We find that clustering on even prices is a positive function of stock price and various proxies for the dispersion in investors’ reservation prices. The preference for even prices affects stock quotes: Investors are more likely to submit a quote improving limit order if the limit price is even and quoted depth is higher for even quotes than for odd quotes.
Asteroid pairs: A complex picture Pravec, P.; Fatka, P.; Vokrouhlický, D. ...
Icarus (New York, N.Y. 1962),
11/2019, Letnik:
333
Journal Article
Recenzirano
We studied a sample of 93 asteroid pairs, i.e., pairs of genetically related asteroids that are on highly similar heliocentric orbits. We estimated times elapsed since separation of pair members ...(i.e., pair age) that are between 7 × 103 yr and a few 106 yr. With photometric observations, we derived the rotation periods P1 for all the primaries (i.e., the larger members of asteroid pairs) and a sample of secondaries (the smaller pair members). We derived the absolute magnitude differences of the studied asteroid pairs that provide their mass ratios q. For a part of the studied pairs, we refined their WISE geometric albedos and collected or estimated their taxonomic classifications. For 17 asteroid pairs, we also determined their pole positions. In two pairs where we obtained the spin poles for both pair components, we saw the same sense of rotation for both components and constrained the angles between their original spin vectors at the time of their separation. We found that the primaries of 13 asteroid pairs in our sample are actually binary or triple systems, i.e., they have one or two bound, orbiting secondaries (satellites). As a by-product, we found also 3 new young asteroid clusters (each of them consisting of three known asteroids on highly similar heliocentric orbits). We compared the obtained asteroid pair data with theoretical predictions and discussed their implications. We found that 86 of the 93 studied asteroid pairs follow the trend of primary rotation period vs mass ratio that was found by Pravec et al. (2010). Of the 7 outliers, 3 appear insignificant (may be due to our uncertain or incomplete knowledge of the three pairs), but 4 are high mass ratio pairs that were unpredicted by the theory of asteroid pair formation by rotational fission. We discuss a (remotely) possible way that they could be created by rotational fission of flattened parent bodies followed by re-shaping of the formed components. The 13 asteroid pairs with binary primaries are particularly interesting systems that place important constraints on formation and evolution of asteroid pairs. We present two hypotheses for their formation: The asteroid pairs having both bound and unbound secondaries could be “failed asteroid clusters”, or they could be formed by a cascade primary spin fission process. Further studies are needed to reveal which of these two hypotheses for formation of the paired binary systems is real.
We have examined 40 normal subjects (20 men and 20 women) to determine the ideal range of motion required to perform activities of daily living. The amount of wrist flexion and extension, as well as ...radial and ulnar deviation, was measured simultaneously by means of a biaxial wrist electrogoniometer. The entire battery of evaluated tasks could be achieved with 60 degrees of extension, 54 degrees of flexion, 40 degrees of ulnar deviation, and 17 degrees of radial deviation, which reflects the maximum wrist motion required for daily activities. The majority of the hand placement and range of motion tasks that were studied in this project could be accomplished with 70 percent of the maximal range of wrist motion. This converts to 40 degrees each of wrist flexion and extension, and 40 degrees of combined radial-ulnar deviation. This study provides normal standards for the functional range of motion of the wrist.
•Membership, size and rotational properties of 13 young asteroid clusters studied.•A model of rotational fission of parent asteroid to a multi-component system made.•The properties of 11 clusters are ...consistent with being formed by fission process.•A possibility of cascade disruption was found for some of the clusters.
We studied the membership, size ratio and rotational properties of 13 asteroid clusters consisting of between 3 and 19 known members that are on similar heliocentric orbits. By backward integrations of their orbits, we confirmed their cluster membership and estimated times elapsed since separation of the secondaries (the smaller cluster members) from the primary (i.e., cluster age) that are between 105 and a few 106 years. We ran photometric observations for all the cluster primaries and a sample of secondaries and we derived their accurate absolute magnitudes and rotation periods. We found that 11 of the 13 clusters follow the same trend of primary rotation period vs mass ratio as asteroid pairs that was revealed by Pravec et al. (2010). We generalized the model of the post-fission system for asteroid pairs by Pravec et al. (2010) to a system of N components formed by rotational fission and we found excellent agreement between the data for the 11 asteroid clusters and the prediction from the theory of their formation by rotational fission. The two exceptions are the high-mass ratio (q > 0.7) clusters of (18777) Hobson and (22280) Mandragora for which a different formation mechanism is needed. Two candidate mechanisms for formation of more than one secondary by rotational fission were published: the secondary fission process proposed by Jacobson and Scheeres (2011) and a cratering collision event onto a nearly critically rotating primary proposed by Vokrouhlický et al. (2017). It will have to be revealed from future studies which of the clusters were formed by one or the other process. To that point, we found certain further interesting properties and features of the asteroid clusters that place constraints on the theories of their formation, among them the most intriguing being the possibility of a cascade disruption for some of the clusters.
Triangular fibrocartilage tears Cooney, W P; Linscheid, R L; Dobyns, J H
The Journal of hand surgery (American ed.)
19, Številka:
1
Journal Article
Recenzirano
From a series of 56 patients with triangular fibrocartilage injury, 33 patients with peripheral rim tears not associated with instability of the distal radioulnar joint were identified by ...arthrography or arthroscopy. Open repair of the peripheral tear produced 11 excellent, 15 good, 6 fair, and 1 poor result (grading based on a Mayo modified Green-O'Brien wrist score). Ulnar recession improved surgical exposure and corrected ulnar variance in 11 patients. A dorsal approach for repair of radial and anterior peripheral rim tears was used in 28 patients. Repair of peripheral tears restored functional integrity to the triangular fibrocartilage, and good to excellent results are reported in 26 of the patients treated.
In sharp contrast to results in the United States, the average stock price response to an announcement of a seasoned equity issue in Japan is positive. Offer prices in Japan, unlike the United ...States, are announced several days before the beginning of the subscription period and incorporate a substantial discount. We suggest that the positive announcement effects in Japan are consistent with the underwriter's certification of the issuing firm's value. We characterize the underwriter's risk as a put option and find a positive association between the underwriter's risk and the announcement returns, as well as other results consistent with underwriter certification.
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