917 research outputs found

    Preliminary results of geologic and remote sensing studies of Rima Mozart

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    In order to better understand the processes responsible for the formation of lunar sinuous rilles, a study of Rima Mozart was conducted using a variety of geologic, photographic, and remote sensing data. The apparent source of this rille is located in a highlands unit of known composition and it is hypothesized that thermal and mechanical erosion played an important role in the formation of Rima Mozart. Excellent photographic, topographic, multispectral, and radar data exist for this rille. The preliminary results of an analysis of this data are presented. Photographic data indicates the presence of two volcanic source vents for Rima Mozart: Kathleen and Ann. It is suggested that Rima Mozart, like many other lunar sinuous rilles, was most likely formed by a combination of events. Rima Mozart does follow a pre-existing, dominant NW/SE structural trend suggesting the influence of structural features on the rille, however, the tectonic influence is not the sole source for the formation of the rille, as suggested by the presence of the two source vents and the spatter around Ann. It is suggested that the rille formation began with an explosive eruption at Kathleen which later calmed down to a pulsating, high volume, low-viscosity lava flow. The rapid effusion rate of the magma as well as its high temperature and turbid nature helped carve the sinuous rille into the fractured and structurally weak Apennine Bench Formation underneath. Similar eruptions and subsequent flows were also created at Ann and joined to the main channel by a NE-trending secondary rille

    Asteroid amphitrite: Surface composition and prospects for the possible Galileo flyby

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    Studies of the trajectory of the Galileo mission to Jupiter recently revealed that the spacecraft can pass close to one of the largest asteroids (#29 Amphitrite). NASA has therefore altered the mission plan of the Galileo spacecraft to include a possible close flyby of Amphitrite in early December 1986, if the condition of the spacecraft allows. If this option is actually implemented, Amphitrite will become the only asteroid for which any high-spatial resolution images and reflection spectra will be available. To evaluate the value of this data and place Amphitrite in the context of the more than 600 asteroids for which some compositional information exists. Existing data was reexamined, new telescopic spectra of Amphitrite were obtained, and simulated Galileo data sets were constructed

    Dynamics and Gravitational Wave Signature of Collapsar Formation

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    We perform 3+1 general relativistic simulations of rotating core collapse in the context of the collapsar model for long gamma-ray bursts. We employ a realistic progenitor, rotation based on results of stellar evolution calculations, and a simplified equation of state. Our simulations track self-consistently collapse, bounce, the postbounce phase, black hole formation, and the subsequent early hyperaccretion phase. We extract gravitational waves from the spacetime curvature and identify a unique gravitational wave signature associated with the early phase of collapsar formation

    Dynamics and gravitational wave signature of collapsar formation

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    We perform 3+1 general relativistic simulations of rotating core collapse in the context of the collapsar model for long gamma-ray bursts. We employ a realistic progenitor, rotation based on results of stellar evolution calculations, and a simplified equation of state. Our simulations track self-consistently collapse, bounce, the postbounce phase, black hole formation, and the subsequent early hyperaccretion phase. We extract gravitational waves from the spacetime curvature and identify a unique gravitational wave signature associated with the early phase of collapsar formatio

    Preliminary results of spectral reflectance studies of tycho crater

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    The preliminary analysis and interpretation of near infrared spectra obtained for both the interior and exterior deposits associated with the Tycho crater is presented. Specific objectives were: (1) to determine the composition and stratigraphy of the highland crust in the Tycho target site; (2) to determine the likely composition of the primary ejecta which may be present in ray deposits; (3) to investigate the nature of spectral units defined in previous studies; (4) to further investigate the nature and origin of both the bright and dark haloes around the rim crest; and (5) to compare the compositions determined for the Tycho units with those of the Aristarchus crater as well as typical highland deposits. The spectra obtained for the interior areas exhibit similar spectral features. These include relatively strong 1 micron absorption bands whose minima are centered between 0.97 and 0.99 microns and shallow to intermediate continuum slopes. The spectra generally exhibit indications of a 1.3 micron feature consistent with the presence of Fe(2+) bearing plagioclase feldspar. The strong 1 micron absorption features indicate a dominant high Ca clinopyroxene component. Results obtained from the ejecta deposits show that the spectrum of the inner, bright halo is almost identical with those obtained for interior units. The spectrum of the dark halo exhibits a wide, relatively shallow absorption feature centered at 1.01 microns, a 1.3 micron absorption, and a steep continuum slope. This spectrum is interpreted as indicating the presence of pyroxene, Fe-bearing feldspar, and a significant component of Fe-bearing impact melt glass. Finally, the spectra of spots inside Tycho show similarity with certain spectra for Aristarchus. However, the suite of spectra obtained for Tycho exhibits a different trend in terms of band center versus width

    “You can help people”: Adolescents’ Views on Engaging Young People in Longitudinal Research

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    We sought to discover adolescents’ thoughts about participation in longitudinal research and identify recruitment and retention strategies that were meaningful to them. We conducted seven focus groups with 10–15-year-olds in two large rural centers in New South Wales, Australia, and all focus groups were digitally recorded, transcribed, and analyzed. Adolescents discussed factors salient to their involvement in focus groups, as well as factors that may influence involvement in a longitudinal study. At the outset of the focus groups, adolescents had a positive view of “research,” but were reluctant to engage in research that involved biologic samples. Effective recruitment of adolescents requires an appreciation of motivators, and time and resources to extend potential participants’ understanding.Supported by Sydney Medical School Foundation

    Nature and extent of outpatient podiatry service utilisation in people with diabetes undergoing minor foot amputations : a retrospective clinical audit

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    Background: People with diabetes are at high risk of foot complications that can lead to lower extremity amputations. National standards suggest that early assessment and management by a podiatry led multidisciplinary high-risk foot clinic (HRFC) helps to reduce complications. This review is a retrospective audit of the Central Coast Local Health District (CCLHD) podiatry department service utilisation in people with diabetes who had undergone a minor foot amputation. Methods: All people with diabetes who had minor foot amputations in the calendar year 2017 in the CCLHD in New South Wales were identified. Podiatry occasions of service from all podiatry service clinics (e.g. general, orthoses, wound, HRFC) and hospital stays for 12 months prior to, and 12 months, post the minor foot amputation were extracted. Results: Data on 74 people with diabetes who underwent 85 minor foot amputations were collected. In the 12-month period leading up to their minor foot amputation less than half, 42% (n=31), of the patients had attended any of the available podiatry service clinics within the CCLHD system. Post-amputation and discharge from hospital there was an overall rise of 26% in numbers attending all CCLHD podiatry- led clinics bringing the total to 68% (51). However, attendance at the HRFC rose by only 2% from 16% (n=12) to 18% n= (13). Conclusion: This study shows that there was underutilisation of Podiatry Services in the CCLHD in 2017 with some participants not meeting national treatment guidelines for foot health services. Revision of current referral pathways both prior to, during and following hospitalisation and expanding the multidisciplinary HRFC to accommodate the population by providing more accessible locations has since been undertaken to increase service access. Further provision of education to those highlighted to be at high risk has also been implemented

    Text messaging is a useful reminder tool

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    Introduction Longitudinal studies of adolescents must be ‘adolescent-friendly’, to collect data and to encourage maintenance in the study cohort. Text messaging may offer a feasible means to do both. Methods Adolescents in the Adolescent Rural Cohort, Hormones and Health, Education, Environments and Relationships (ARCHER) study (n=342) are sent automated text messages every 3 months, prompting biological specimen collection. Results A total of 99.2% of participants (or their parents) owned a mobile phone, of which 89.1% of participants responded to text messages and 97.3% of intended urine samples were collected. The average time to provide a urine sample after prompting correlated with time to reply to Short Message Service (SMS). Conclusions This study shows SMS can be used effectively in longitudinal research involving adolescents and is feasible and useful as a reminder tool for regular biological specimen collection.Australian National Health and Medical Research Counci

    Remote sensing and geologic studies of the orientale basin region

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    Both visual and near-infrared spectral observations are combined with multispectral imaging to study the Orientale interior and exterior, the Cruger region, Grimaldi Region, the Schiller-Schickard Region, and the Humorum Region of the Moon. It was concluded that anorthosites occur in the Inner Rook Mountains of Orientale, the inner ring of Grimaldi, and the main ring of Humorum. Imaging spectroscopy shows that the entire eastern Inner Rook Mountains are composed of anorthosites. Orientale ejecta are strikingly like the surface materials in the region where Apollo 16 landed. This similarity indicates similar mineralogy, i.e., noritic anorthosite. Thus, Orientile ejecta is more mafic than the Inner Rook Mountains. This situation is also true for the Nectaris, Humorum, and Gramaldi basins. Isolated areas of the Orientale region show the presence of gabbroic rocks, but, in general, Orientale ejecta are noritic anorthosites, which contain much more low-Ca pyroxene than high-Ca pyroxene. Ancient (pre-Orientale) mare volcanism apparently occurred in several areas of the western limb
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