Spacelab simulation using a Lear Jet aircraft: Mission no. 4 (ASSESS program)

The fourth ASSESS Spacelab simulation mission utilizing a Lear Jet aircraft featured trained experiment operators (EOs) in place of the participating scientists, to simulate the role and functions of payload specialists in Spacelab who may conduct experiments developed by other scientists. The experiment was a broadband infrared photometer coupled to a 30-cm, open port, IR telescope. No compromises in equipment design or target selection were made to simplify operator tasks; the science goals of the mission were selected to advance the mainline research program of the principle investigator (PI). Training of the EOs was the responsibility of the PI team and consisted of laboratory sessions, on-site training during experiment integration, and integrated mission training using the aircraft as a high-fidelity simulator. The EO permission experience in these several disciplines proved adequate for normal experiment operations, but marginal for the identification and remedy of equipment malfunctions. During the mission, the PI utilized a TV communication system to assist the EOs to overcome equipment difficulties; both science and operations were successfully implemented

Shuttle spacelab simulation using a Lear jet aircraft: Mission no. 3 (ASSESS program)

The third ASSESS mission using a Lear Jet aircraft conducted to continue the study of scientific experiment operations in a simulated Spacelab environment. Prior to the mission, research planning and equipment preparation were observed and documented. A flight readiness review for the experiment was conducted. Nine of the ten scheduled flights were completed during simulation mission and all major science objectives were accomplished. The equipment was well qualified for flight and gave little trouble; telescope malfunctions occurred early in the mission and were corrected. Both real-time and post-observation data evaluation were used to assess research progress and to plan subsequent flight observations for maximum effectiveness

Recommendations concerning energy information model documentation, public access, and evaluation

In this study we provide an analysis of the factors underlying Congressional concern regarding model documentation, policies for public access, and evaluation procedures of the Energy Information Administration (EIA) and its predecessor agencies; we also develop and present recommendations designed to improve current practice. This study reviews the history of Congressional concern; surveys current EIA organization and policies; provides an analysis of the model evaluation process; and presents recommendations to improve organizational efficiency and responsiveness, the model documentation process, public access policies, and model evaluation

Analysis quality report on the EIA Annual Report to Congress 1978, volume III : coal supply

The Energy Information Administration (EIA) is charged by Congress to prepare an Annual Report to Congress (ARC) which includes projections of energy supplies, consumption and prices, as well as the relation of energy to other economic activity. As an aid to users of ARC, the EIA Office of Analysis Oversight and Access (OAOA) is preparing "Analysis Quality Reports" on particular components of the energy information analysis system used in developing the ARC-78 projections. This report focuses on the Coal Supply Module used for the midterm projections of the ARC-78. The Coal Supply Module is part of the EIA's National Coal Model. The review and analysis presented here is based upon the MIT Energy Model Analysis Program's (EMAP) evaluation of the documentation and implementation of the Coal Supply Module sponsored by OAOA, and an indepth evaluation of a related model--the ICF Coal and Electric Utilities Model--which also employs the EIA Coal Supply Module. The indepth evaluation has been sponsored by the Electric Power Research Institute

A Reanalysis of the Carbon Abundance in the Translucent Cloud toward HD 24534

We have reanalyzed the Goddard High Resolution Spectrograph data set presented by Snow et al. which contains the interstellar intersystem C II] 2325A line through the translucent cloud toward HD 24534 (X Persei). In contrast to the results of Snow et al., we clearly detect the C II] feature at the 3-sigma confidence level and measure a C^+ column density of 2.7 +/- 0.8 x 10^17 cm^-2. Accounting for the C I column density along the line of sight, we find 10^6 C/H = 106 +/- 38 in the interstellar gas toward this star. This gas-phase carbon-to-hydrogen ratio suggests that slightly more carbon depletion may be occurring in translucent as compared to diffuse clouds. The average diffuse-cloud C/H, however, is within the 1-sigma uncertainty of the measurement toward HD 24534. We therefore cannot rule out the possibility that the two cloud types have comparable gas-phase C/H, and therefore comparable depletions of carbon.Comment: 9 pages, 3 figures, to appear in the Astrophysical Journal Letter

SOST and DKK: Antagonists of LRP Family Signaling as Targets for Treating Bone Disease

The study of rare human genetic disorders has often led to some of the most significant advances in biomedical research. One such example was the body of work that resulted in the identification of the Low Density Lipoprotein-Related Protein (LRP5) as a key regulator of bone mass. Point mutations were identified that encoded forms of LRP5 associated with very high bone mass (HBM). HBM patients live to a normal age and do not appear to have increased susceptibility to carcinogenesis or other disease. Thus, devising methods to mimic the molecular consequences of this mutation to treat bone diseases associated with low bone mass is a promising avenue to pursue. Two groups of agents related to putative LRP5/6 functions are under development. One group, the focus of this paper, is based on antagonizing the functions of putative inhibitors of Wnt signaling, Dickkopf-1 (DKK1), and Sclerostin (SOST). Another group of reagents under development is based on the observation that LRP5 may function to control bone mass by regulating the secretion of serotonin from the enterrochromaffin cells of the duodenum

Building brains in a dish: Prospects for growing cerebral organoids from stem cells

AbstractThe recent development of organoid techniques, in which embryonic brain-like tissue can be grown from human or mouse stem cells in vitro offers the potential to transform the way in which brain development is studied. In this review, we summarize key aspects of the embryonic development of mammalian forebrains, focussing in particular on the cerebral cortex and highlight significant differences between mouse and primates, including human. We discuss recent work using cerebral organoids that has revealed key similarities and differences between their development and that of the brain in vivo. Finally, we outline the ways in which cerebral organoids can be used in combination with CRISPR/Cas9 genome editing to unravel genetic mechanisms that control embryonic development of the cerebral cortex, how this can help us understand the causes of neurodevelopmental disorders and some of the key challenges which will have to be resolved before organoids can become a mainstream tool to study brain development

Foundations of a Finite Non-Equilibrium Statistical Thermodynamics: Extrinsic Quantities

Statistical thermodynamics is valuable as a conceptual structure that shapes our thinking about equilibrium thermodynamic states. A cloud of unresolved questions surrounding the foundations of the theory could lead an impartial observer to conclude that statistical thermodynamics is in a state of crisis though. Indeed, the discussion about the microscopic origins of irreversibility has continued in the scientific community for more than a hundred years. This paper considers these questions while beginning to develop a statistical thermodynamics for finite non-equilibrium systems. Definitions are proposed for all of the extrinsic variables of the fundamental thermodynamic relation that are consistent with existing results in the equilibrium thermodynamic limit. The probability density function on the phase space is interpreted as a subjective uncertainty about the microstate, and the Gibbs entropy formula is modified to allow for entropy creation without introducing additional physics or modifying the phase space dynamics. Resolutions are proposed to the mixing paradox, Gibbs' paradox, Loschmidt's paradox, and Maxwell's demon thought experiment. Finally, the extrinsic variables of the fundamental thermodynamic relation are evaluated as functions of time and space for a diffusing ideal gas, and the initial and final values are shown to coincide with the expected equilibrium values when interpreted in a classical context.Comment: 18 pages, 10 figure