Observations of the D/H ratio in Methane in the atmosphere of Saturn's moon, Titan - where did the Saturnian system form?

The details of the Solar system's formation are still heavily debated. Questions remain about the formation locations of the giant planets, and the degree to which volatile material was mixed throughout the proto-planetary system. One diagnostic which offers great promise in helping to unravel the history of planet formation is the study of the level of deuteration in various Solar system bodies. For example, the D/H ratio of methane in the atmosphere of Titan can be used as a diagnostic of the initial conditions of the solar nebula within the region of giant planet formation, and can help us to determine where Titan (and, by extension, the Saturnian system) accreted its volatile material. The level of Titanian deuteration also has implications for both the sources and long term evolution of Titan's atmospheric composition. We present the results of observations taken in the 1.58 microns window using the NIFS spectrometer on the Gemini telescope, and model our data using the VSTAR line--by--line transfer model, which yields a D/H ratio for Titan's atmosphere of 143+/-16) x 10^{-6} [1]. We are currently in the process of modeling the Gemini high resolution GNIRS spectra using new sets of line parameters derived for methane in the region between 1.2-1.7 microns [2].Comment: 12 pages, 4 figures, Accepted for publication in proceedings of the Australian Space Science Conference 201

Prospects for improved Λc\Lambda_c branching fractions

The experimental uncertainty on the branching fraction \b(\Lambda_c \to p K^- \pi^+) = (5.0 \pm 1.3)% has not decreased since 1998, despite a much larger data sample. Uncertainty in this quantity dominates that in many other quantities, including branching fractions of $\Lambda_c$ to other modes, branching fractions of $b$-flavored baryons, and fragmentation fractions of charmed and bottom quarks. Here we advocate a lattice QCD calculation of the form factors in $\Lambda_c \to \Lambda \ell^+ \nu_\ell$ (the case $\ell = e^+$ is simpler as the mass of the lepton can be neglected). Such a calculation would yield an absolute prediction for the rate for $\Lambda_c \to \Lambda \ell^+ \nu_\ell$. When combined with the $\Lambda_c$ lifetime, it could provide a calibration for an improved set of $\Lambda_c$ branching fractions as long as the accuracy exceeds about 25%.Comment: 8 pages, 2 figures, version to be published in Phys.\ Rev.\

Coastal adaptations and submerged landscapes : Where world prehistory meets underwater archaeology

Studies in world prehistory, which include the transition between the Pleistocene and Holocene and the cultural shift from Forager to Farmer, remain incomplete, particularly along the coastal margins. Submerged landscape archaeology has begun to emerge as a serious sub-discipline of both maritime archaeology and world prehistory, with a largely untapped potential to fill in significant gaps in the archaeological record. This chapter reviews the current state of submerged landscape archaeology and considers important elements, both theoretical and practical, and discusses how future generations of prehistorians must be willing and able to engage with archaeology on the continental shelves, worldwide

North American Oil and Gas Reserves: Prospects and Policy

Expanding estimates of North America’s supply of accessible shale gas, and more recently, shale oil, have been trumpeted in many circles as the most significant energy resource development since the oil boom in Texas in the late 1920s. How large are these resources? What challenges will need to be overcome if their potential is to be realized? How will they impact U.S. energy policy? To address these questions, the Belfer Center for Science and International Affairs and two of its programs, the Environment and Natural Resources Program and the Geopolitics of Energy Project, convened a group of experts from business, government, and academia on May 1, 2012, in Cambridge, Massachusetts. The following report summarizes the major issues discussed at this workshop. Since the discussions were off-the-record, no comments are attributed to any individual. Rather, this report attempts to summarize the arguments on all sides of the issues. The policy implications of significant additional supplies of domestic oil and gas to the United States are far ranging. Due to time constraints, many important issues were not covered in the depth that they deserved. Examples would include the impact of additional oil and gas supplies on existing U.S. efforts to reduce carbon emissions and its historical commitment to support other fuels, such as coal and nuclear power, or newer options, such as wind and solar energy. Further, as one participant pointed out, officials from industry are constrained under U.S. antitrust laws from sharing proprietary information

Development of shear wave velocity profiles in the deep sediments of the Mississippi Embayment using surface wave and spectral ratio methods

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 10, 2009.Thesis (M.S.) University of Missouri-Columbia 2008.The deep soils of the Mississippi Embayment in the central United States will have a significant influence on earthquake ground motions generated by the New Madrid Seismic Zone. The seismic properties of these soils, which extend to depths of over 1000 meters in some areas, are poorly characterized at depths below 60 to 100 meters. This study presents shear wave velocity (Vs) profiles determined from Spectral-Analysis-of-Surface-Waves (SASW) measurements performed at eleven sites in Arkansas, Tennessee, and Missouri. These measurements were performed using the low-frequency field vibrator developed as part of the NSF Network for Earthquake Engineering Simulation (NEES) program. Shear wave velocity profiles were developed to depths of approximately 220 meters at eleven sites located throughout the Mississippi Embayment. In addition to the SASW measurements, ambient noise measurements of horizontal and vertical ground motions were performed to estimate the average Vs over the full profile depth using the H/V spectral ratio method. The Vs profiles derived from the SASW measurements compared well with Vs reference profiles that have been developed for the Mississippi Embayment and used in recent site response studies of the region. The observed variability of the profiles was found to be in general agreement with past assumptions used for the deep soil and correlated with changes in soil lithology. Relationships between the soil formations and Vs were consistent with past studies and provided information to greater depths. Lastly the H/V spectral ratio measurements were successfully applied at each of the eleven sites, but appeared to overestimate the average Vs.Includes bibliographical reference

The spectrum of hot methane in astronomical objects using a comprehensive computed line list

Hot methane spectra are important in environments ranging from flames to the atmospheres of cool stars and exoplanets. A new spectroscopic line list, 10to10, for $^{12}$CH$_4$ containing almost 10 billion transitions is presented. This comprehensive line list covers a broad spectroscopic range and is applicable for temperatures up to 1 500 K. Previous methane data are incomplete leading to underestimated opacities at short wavelengths and elevated temperatures. Use of 10to10 in models of the bright T4.5 brown dwarf 2MASS 0559-14 leads to significantly better agreement with observations and in studies of the hot Jupiter exoplanet HD 189733b leads to up to a twentifold increase in methane abundance. It is demonstrated that proper inclusion of the huge increase in hot transitions which are important at elevated temperatures is crucial for accurate characterizations of atmospheres of brown dwarfs and exoplanets, especially when observed in the near-infrared.Comment: PNAS, Early Edition, June 16, 201

Implementing Panel Corrected Standard Errors in R: The pcse Package

Time-series-cross-section (TSCS) data are characterized by having repeated observations over time on some set of units, such as states or nations. TSCS data typically display both contemporaneous correlation across units and unit level heteroskedasity making inference from standard errors produced by ordinary least squares incorrect. Panel-corrected standard errors (PCSE) account for these these deviations from spherical errors and allow for better inference from linear models estimated from TSCS data. In this paper, we discuss an implementation of them in the R system for statistical computing. The key computational issue is how to handle unbalanced data

Justice, speed and thoroughness in child protection court proceedings: messages from England

This paper reports and assesses the outcomes of a pilot programme in London to reduce the duration of child protection court proceedings. The initiative, known as the ‘Tri-borough Care Proceedings Pilot’, was intended to reduce the usual duration to 26 weeks, ahead of national moves in that direction. The paper locates the issue of court delay in a wider political and child welfare context, highlighting the dilemmas of balancing principles of family autonomy and child safety, support and protection, thoroughness and speed, welfare practices and court processes. It compares the policy, legal and court contexts in the USA and England, showing that what might appear at first sight a local initiative actually relates to a much wider, long-lasting and international debate about how to reach important decisions about children in a reasonable timescale. The paper concludes that there will always be, and must always be, tensions between the courts, national government and local welfare agencies. The pilot shows that greater speed can be achieved by a concerted effort from all the agencies, but at the same time the division of powers and responsibilities is a bedrock for protecting individual rights in liberal democratic societies. Welfare and legal practitioners alike need to appreciate this tension in child protection policy and practice, and resist recrimination when there are differences of opinion. Knowing that other countries face the same challenges can help to promote a more realistic and sophisticated understanding of the dilemmas and the implications for practice, and so help to bring about better decisions for children

Outcomes for children of shorter court decision-making processes:A follow-up study of the Tri-borough care proceedings pilot

Context: Long-standing concerns about unnecessary delay in care proceedings led to major reforms in 2013-14, intended to reduce the normal duration to 26 weeks. Prior to those national changes, the Tri-borough authorities in London (Hammersmith & Fulham, Westminster, Kensington & Chelsea) launched a pilot project to try to hit the 26 week target. It ran from April 2012 to March 2013. The project was evaluated by a team from the CRCF. They were subsequently commissioned to undertake a follow-up study to track and evaluate the longer-term outcomes for the children. Aims: The original evaluation compared the timings and outcomes of care proceedings in the pre-pilot year (2011-12) and the pilot year (2012-13). This gives a combined database of 180 cases (256 children), and a unique opportunity to track and compare longer-term progress and outcomes for the children. The follow-up study aimed to assess whether or not delay had shifted to the post-court stage, and whether the new regime led to different long-term outcomes. The research tracked what had happened to the children in the two years after their proceedings ended. It measured the time to reach their planned permanent placement, whether placements endure (at home, kinship care or foster care), and the children’s well-being. Methods: There was a file survey to track the progress of all the children who had been involved in care proceedings in the pre-pilot and pilot years. There was also a questionnaire for parents and carers of the children, to get their views on the child’s progress and the support they received, and interviews with social workers in the Tri-borough authorities on how they perceived the new approach to court proceedings to be working, four years on. Findings: The original evaluation found that the Tri-borough pilot succeeded in its key aim of reducing the length of care proceedings. The median duration of care proceedings was 27 weeks compared to 49 weeks the year before, a reduction of 45%. The pattern of final orders was broadly the same for cases in the pilot year as in the year before, suggesting that the drive to speed up proceedings does not result in significantly different court outcomes. The follow up study had four main findings. First, reducing the duration of care proceedings did not mean that more children were left waiting for a permanent placement at the end of the proceedings. On the contrary, a slightly higher proportion of children in the pilot year were already in their planned permanent placement at the end of the proceedings (65% compared to 60% the year before). Second, for those who did need to move to a permanent placement afterwards, the focus on shorter care proceedings did not lead to extra delay here. In fact, the average duration fell from 30 weeks to 14, a reduction of over 50%. Third, the incidence of ‘serious problem indicators’ (e.g. breakdowns in permanent placements, renewed child protection concerns) declined for children from the pilot cohort compared to the pre-pilot cohort. This suggests that quicker decision-making processes do not necessarily lead to less stable placements for children. Rather, the focus on good decision-making can lead to more secure outcomes. And fourth, shorter care proceedings did not result in more children living away from their families. The most frequent type of final placement for children in both cohorts was with their parent(s) followed by placements with relatives or friends. Impact: The original evaluation was widely quoted and circulated, because it showed that the 26 week target could be achieved without compromising justice and thoroughness, as long as there is proper regard for flexibility. The researchers have continued to disseminate the key messages through publications and presentations at professional and academic conferences. The researchers now aim to disseminate the information about what happens after proceedings