Geologic Map of the Ganiki Planitia Quadrangle (V–14), Venus

Our current research focuses on addressing four specific questions. Has the dominant style of volcanic expression within the quadrangle varied in a systematic fashion over time? Does the tectonic deformation within the quadrangle record significant regional patterns that vary spatially or temporally, and if so what are the scales, orientations and sources of the stress fields driving this deformation? If mantle upwelling and downwelling have played a significant role in the formation of Atla Regio and Atalanta Planitia as has been proposed, does the geology of Ganiki Planitia record evidence of northwest-directed lateral mantle flow connecting the two sites? Finally, can integration of the tectonic and volcanic histories preserved within the quadrangle help constrain competing resurfacing models for Venus

Sex Differences in Preferences for Humor: A Replication, Modification, and Extension

Evolutionary-minded scientists have proposed that humor is a sexually selected trait in men that signals mate quality. Indeed, women tend to prefer men who make them laugh and men tend to prefer women who laugh at their jokes. However, it is unclear how robust this pattern is. Here we report a replication of one of the first studies ( Bressler, Martin, and Balshine, 2006 ) to examine the sex differences in preferences for humor receptivity versus humor production. We replicate Bressler et al.'s (2006) findings that men prefer women who are receptive to their humor whereas women prefer men who produce humor. These findings held even after we modified Bressler et al.'s questionnaire for better conceptual validity. Furthermore, using a separate measure designed to assess trade-offs, we found that men viewed humor receptivity as a necessity and humor production as a luxury when they were asked to create an ideal long-term partner. For women, it was just the opposite. These results bolster the claim that sexual selection has shaped sex differences regarding preferences for a prospective mate's sense of humor and that what one means by “sense of humor” can vary

Potential strategies to reduce medial compartment loading in patients with knee osteoarthritis of varying severity: reduced walking speed

To determine whether reducing walking speed is a strategy used by patients with knee osteoarthritis (OA) of varying disease severity to reduce the maximum knee adduction moment.; Self-selected walking speeds and maximum knee adduction moments of 44 patients with medial tibiofemoral OA of varying disease severity, as assessed by using the Kellgren/Lawrence grade, were compared with those of 44 asymptomatic control subjects matched for sex, age, height, and weight.; Differences in self-selected normal walking speed explained only 8.9% of the variation in maximum knee adduction moment for the group of patients with knee OA. The severity of the disease influenced the adduction moment-walking speed relationship; the individual slopes of this relationship were significantly greater in patients with less severe OA than in asymptomatic matched control subjects. Self-selected walking speed did not differ between patients with knee OA, regardless of the severity, and asymptomatic control subjects. However, knees with more-severe OA had significantly greater adduction moments (mean +/- SD 3.80 +/- 0.89% body weight x height) and were in more varus alignment (6.0 +/- 4.5 degrees ) than knees with less-severe OA (2.94 +/- 0.70% body weight x height; and 0.0 +/- 2.9 degrees, respectively).; Patients with less-severe OA adapt a walking style that differs from that of patients with more-severe OA and controls. This walking style is associated with the potential to reduce the adduction moment when walking at slower speeds and could be linked to decreased disease severity

Dynamic function after anterior cruciate ligament ~ . reconstruction with autologous patellar tendon

ABSTRACT The purpose of this study was to dynamically assess the functional outcome of patients who had undergone successful anterior cruciate ligament reconstruction using an autologous patellar tendon technique and to determine whether their dynamic knee function was related to quadriceps and hamstring muscle strength. The knee kinematics and kinetics of 22 subjects who had undergone anterior cruciate ligament reconstruction (mean age, 27 Ϯ 11 years) and of 22 age-and sex-matched healthy control subjects were determined during various dynamic activities using a computerized motion analysis and force plate system. The differences in the sagittal plane angles and external moments between the two groups during light (walking), moderate (climbing and descending stairs), and higher-demand (jogging, jog and cut, jog and stop) activities were related to isokinetic strength measurements. Although patients who are asymptomatic and functioning well after anterior cruciate ligament reconstruction can perform normally in light activities, higher-demand activities reveal persistent functional adaptations that require further study. Injury to the ACL leads to knee instability and functional adaptations. Although many ACL-deficient patients display little or no visible impairment (primarily because of activity modification), previous studies have shown that patients with ACL deficiencies walk and perform more stressful activities differently than do uninjured subjects, with most of the differences occurring in the sagittal plane angles and moments. The purpose of our study was to determine whether functional adaptations during gait and other low-and high-demand activities were present in patients with an ACL bone-patellar tendon reconstruction and, if so, whether they were related to strength. More specifically, we examined how the sagittal plane joint angles and external moments during walking, stair-climbing, and jogging activities differed between healthy subjects and patients with a reconstructed ACL and whether those differences related to isokinetic quadriceps and hamstring muscle strength. MATERIALS AND METHODS Twenty-two subjects (mean age, 27 Ϯ 11 years) who underwent an autogenous patellar tendon reconstruction for ACL deficiency were tested and compared with a group of 22 uninjured control subjects. The ACL-reconstructed group consisted of 13 men and 9 women. Patients in the ACL-reconstructed group underwent surgery at an average of 8 months (range, 1 to 24) after injury and were examined at a mean follow-up of 22 Ϯ 12 months. Excluded from the study were those patients who had meniscal damage in which more than 25% of the meniscus was removed, posterior cruciate or collateral ligament injury, articular surface injury, symptomatic anterior knee pain, or objective instability at latest follow-up examination (positive pivot shift test results, positive Lachman † Address correspondence and reprint requests to Charles A. Bush-Joseph, MD, Rush-Presbyterian-St

Hollows on Mercury: MESSENGER Evidence for Geologically Recent Volatile-Related Activity

High-resolution images of Mercury’s surface from orbit reveal that many bright deposits within impact craters exhibit fresh-appearing, irregular, shallow, rimless depressions. The depressions, or hollows, range from tens of meters to a few kilometers across, and many have high-reflectance interiors and halos. The host rocks, which are associated with crater central peaks, peak rings, floors, and walls, are interpreted to have been excavated from depth by the crater-forming process. The most likely formation mechanisms for the hollows involve recent loss of volatiles through some combination of sublimation, space weathering, outgassing, or pyroclastic volcanism. These features support the inference that Mercury’s interior contains higher abundances of volatile materials than predicted by most scenarios for the formation of the solar system’s innermost planet

Analyses of robotic traverses and sample sites in the Schrödinger basin for the HERACLES Human-Assisted Sample Return Mission concept

The International Space Exploration Coordination Group (ISECG) developed an integrated Global Exploration Roadmap (GER) that outlines plans for human-assisted sample return from the lunar surface in ∼2024 and for human presence on the lunar surface in ∼2028. Previous studies have identified the Schrödinger basin, situated on the far side of the Moon, as a prime target for lunar science and exploration where a significant number of the scientific concepts reviewed by the National Research Council (NRC, 2007) can be addressed. In this study, two robotic mission traverses within the Schrödinger basin are proposed based on a 3 year mission plan in support of the HERACLES human-assisted sample return mission concept. A comprehensive set of modern remote sensing data (LROC imagery, LOLA topography, M3 and Clementine spectral data) has been integrated to provide high-resolution coverage of the traverses and to facilitate identification of specific sample localities. We also present a preliminary Concept of Operations (ConOps) study based on a set of notional rover capabilities and instrumental payload. An extended robotic mission to the Schrödinger basin will allow for significant sample return opportunities from multiple distinct geologic terrains and will address multiple high-priority NRC (2007) scientific objectives. Both traverses will offer the first opportunity to (i) sample pyroclastic material from the lunar farside, (ii) sample Schrödinger impact melt and test the lunar cataclysm hypothesis, (iii) sample deep crustal lithologies in an uplifted peak ring and test the lunar magma ocean hypothesis and (iv) explore the top of an impact melt sheet, enhancing our ability to interpret Apollo samples. The shorter traverse will provide the first opportunity to sample farside mare deposits, whereas the longer traverse has significant potential to collect SPA impact melt, which can be used to constrain the basin-forming epoch. These robotic missions will revalidate existing lunar surface capabilities and pioneer new ones and, thus, provide important precursor results for subsequent human missions to the lunar surface