The composition of Jupiter and the primordial distribution of the heavy elements are determined by its formation history. As a result, in order to constrain the primordial internal structure of Jupiter the growth of the core and the deposition and settling of accreted planetesimals must be followed in detail. In this paper we determine the distribution of the heavy elements in proto-Jupiter and determine the mass and composition of the core. We find that while the outer envelope of proto-Jupiter is typically convective and has an homogeneous composition, the innermost regions have compositional gradients. In addition, the existence of heavy elements in the envelope leads to much higher internal temperatures (several times 10 4 K) than in the case of a hydrogen-helium envelope. The derived core mass depends on the actual definition of the core: if the core is defined as the region in which the heavy-element mass fraction is above some limit (say 0.5), then it can be much more massive (∼ 15 M ⊕ ) and more extended (10% of the planet's radius) than in the case where the core is just the region with 100% heavy elements. In the former case Jupiter's core also consists of hydrogen and helium. Our results should be taken into account when constructing internal structure models of Jupiter and when interpreting the upcoming data from the Juno (NASA) mission.Subject headings: planets and satellites: individual (Jupiter) -planets and satellites:interiors -planets and satellites: composition -planets and satellites: formation -planets and satellites: gaseous planets 1

Background Abnormal tibiofemoral contact stress and aberrant kinematics may influence the progression of osteoarthritis in the ACL-deficient and the ACL-reconstructed knee. However, relationships between contact stress and kinematics following ACL reconstruction are poorly understood. Therefore, we posed the following research questions: (1) How do ACL deficiency and reconstruction affect kinematics of and contact stress in the tibiofemoral joint? (2) What kinematic differences are associated with abnormal contact stress following ACL reconstruction? Hypothesis/Purpose Center-center ACL reconstruction will not restore knee kinematics and contact stress. Correlations will exist between abnormal contact stress and aberrant kinematics following ACL reconstruction will exist. Study Design Controlled laboratory study Methods Clinical tests of anterior and rotational stability were simulated on eleven cadaveric knees using an industrial robot. Tests were conducted with the ACL intact, sectioned, and after single bundle ACL reconstruction using a quadrupled hamstring autograft with tunnels drilled through the center of the native footprints. Kinematics were recorded during the tests. Contact stress was continuously recorded from a stress transducer fixed to the tibial plateau and mean contact stress was calculated regionally. Results ACL deficiency resulted in increased mean contact stress in the posterior sectors of the medial and lateral compartments under anterior and rotational loads, respectively. Reconstruction reduced stress in these locations; however contact stress abnormalities remained. On average, kinematics were overconstrained following ACL reconstruction (≤1.8mm and ≤2.6° in all directions). However, combinations of overconstrained and underconstrained motions in ab/adduction and medial-lateral translation in response to combined moments, and axial rotation, anterior-posterior and medial-lateral translation in response to an anterior load were associated with abnormal mean contact stress. Conclusions ACL reconstruction reduces high stresses generated in the posterior compartment of the ACL-deficient knee. Abnormal contact stress following ACL reconstruction is related to multiplanar variations in knee kinematics. Clinical Relevance Clinical measures of multiplanar kinematics may help to better characterize the quality of ACL reconstruction. Such measures may help identify those at increased risk of long-term joint degeneration following this surgery.

We present detailed evolutionary calculations spanning 4.6 × 10 9 yr for a model representing main-belt comet 133P/Elst-Pizarro, considering different initial compositions: mixtures of ices and dust. We find that only crystalline H 2 O ice may survive in the interior of the nucleus, and may be found at depths ranging from ∼50 to 150 m. Other volatiles will be completely lost. We further show, by means of fully three-dimensional evolutionary calculations, that if the ice is exposed, say as a result of a collision, the resulting activity is similar to the observed pattern of the behaviour of the comet for a large spin axis inclination, even if only a patch of ice is exposed.

Purpose: To compare the coaxial light intensity required during cataract surgery and rate of postoperative visual recovery, with surgical visualization achieved with a traditional analog operating microscope compared with a 3D digital visualization system. Setting: Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York. Design: Retrospective, consecutive, single-surgeon series. Methods: Patients undergoing femtosecond laser–assisted cataract surgery were retrospectively grouped into either: (1) visualization using the binoculars of a standard operating microscope (traditional group) or (2) visualization using a 3D digital visualization system affixed to the same operating microscope (digital group). Note was made in each case of light intensity used, light exposure time, intraoperative and/or postoperative complications, and postoperative visual acuities. Results: The study comprised 24 eyes in the traditional group and 27 eyes in the digital group. There were no intraoperative or postoperative complications in either group and no difference in mean light exposure time, but the mean light intensity used in the digital group was significantly less (18.5% ± 1.5%) than that in the traditional group (43.3% ± 3.7%; P < .001). Furthermore, the digital group achieved a postoperative day 1 visual acuity that was within 2 lines of the postoperative month 1 visual acuity a greater percentage of time than that in the traditional group (81.5% of eyes vs 54.2% of eyes; P = .04). Conclusions: Light intensity was significantly decreased in patients who underwent cataract surgery assisted by the 3D digital visualization platform without an increase in complications or surgical time and possibly with a faster postoperative visual recovery.