Protoplanetary Disks in the Orion Nebula Cluster: Gas Disk Morphologies and Kinematics as seen with ALMA

We present Atacama Large Millimeter Array CO(3$-$2) and HCO$^+$(4$-$3) observations covering the central $1\rlap{.}'5$$\times$$1\rlap{.}'5$ region of the Orion Nebula Cluster (ONC). The unprecedented level of sensitivity ($\sim$0.1 mJy beam$^{-1}$) and angular resolution ($\sim$$0\rlap{.}''09 \approx 35$ AU) of these line observations enable us to search for gas-disk detections towards the known positions of submillimeter-detected dust disks in this region. We detect 23 disks in gas: 17 in CO(3$-$2), 17 in HCO$^+$(4$-$3), and 11 in both lines. Depending on where the sources are located in the ONC, we see the line detections in emission, in absorption against the warm background, or in both emission and absorption. We spectrally resolve the gas with $0.5$ km s$^{-1}$ channels, and find that the kinematics of most sources are consistent with Keplerian rotation. We measure the distribution of gas-disk sizes and find typical radii of $\sim$50-200 AU. As such, gas disks in the ONC are compact in comparison with the gas disks seen in low-density star-forming regions. Gas sizes are universally larger than the dust sizes. However, the gas and dust sizes are not strongly correlated. We find a positive correlation between gas size and distance from the massive star $\theta^1$ Ori C, indicating that disks in the ONC are influenced by photoionization. Finally, we use the observed kinematics of the detected gas lines to model Keplerian rotation and infer the masses of the central pre-main-sequence stars. Our dynamically-derived stellar masses are not consistent with the spectroscopically-derived masses, and we discuss possible reasons for this discrepancy.Comment: 42 pages, 31 figure

Aerodynamic force measurements with a strain-gage balance in a cryogenic wind tunnel

Aerodynamic force measurements on a generalized 75 deg delta wing model with sharp leading edges were made with a three component internal strain gage balance in a cryogenic wind tunnel at stagnation temperatures of 300 K, 200 K, and 110 K. The feasibility of using a strain gage balance without thermal control in a cryogenic environment as well as the use of electrical resistance heaters, an insulator between the model and the balance, and a convection shield on the balance was investigated. Force and moment data on the delta wing model as measured by the balance are compared at the different temperatures while holding constant either the Reynolds number or the tunnel stagnation pressure. Tests were made at Mach numbers of 0.3 and 0.5 and at angles of attack up to 29 deg. The results indicate that it is feasible to acquire accurate force and moment data while operating at steady state thermal conditions in a cryogenic wind tunnel, either with or without electrical heaters on the balance. Within the limits of the balance accuracy, there were no apparent Reynolds number effects on the aerodynamic results for the delta wind model

Ca2+ leak, what is it? Why should we care? Can it be managed?

For arrhythmia triggers that are secondary to dysfunctional intracellular Ca2+ cycling, there are few if any specific agents that target exactly the Ca2+ handling machinery. However, in the literature to date, several candidates have been proposed. We review here these agents with the idea that in the future these agents or those derived thereof will prove invaluable in clinical application

Hurricane Matthew in 2100: effects of extreme sea level rise scenarios on a highly valued coastal area (Palm Beach, FL, USA)

Sea-level rise represents a severe hazard for populations living within low-elevation coastal zones and is already largely affecting coastal communities worldwide. As sea level continues to rise following unabated greenhouse gas emissions, the exposure of coastal communities to inundation and erosion will increase exponentially. These impacts will be further magnified under extreme storm conditions. In this paper, we focus on one of the most valuable coastal real estate markets globally (Palm Beach, FL). We use XBeach, an open-source hydro and morphodynamic model, to assess the impact of a major tropical cyclone (Hurricane Matthew, 2016) under three different sea-level scenarios. The first scenario (modern sea level) serves as a baseline against which other model runs are evaluated. The other two runs use different 2100 sea-level projections, localized to the study site: (i) IPCC RCP 8.5 (0.83 m by 2100) and (ii) same as (i), but including enhanced Antarctic ice loss (1.62 m by 2100). Our results show that the effective doubling of future sea level under heightened Antarctic ice loss amplifies flow velocity and wave height, leading to a 46% increase in eroded beach volume and the overtopping of coastal protection structures. This further exacerbates the vulnerability of coastal properties on the island, leading to significant increases in parcel inundation

Magnetic Suspension and Balance Systems: A Selected, Annotated Bibliography

This publication, containing 206 entries, supersedes an earlier bibliography, NASA TM-80225 (April 1980). Citations for 18 documents have been added in this updated version. Most of the additions report results of recent studies aimed at increasing the research capabilities of magnetic suspension and balance systems, e.g., increasing force and torque capability, increasing angle of attack capability, and increasing overall system reliability. Some of the additions address the problem of scaling from the relatively small size of existing systems to much larger sizes. The purpose of this bibliography is to provide an up-to-date list of publications that might be helpful to persons interested in magnetic suspension and balance systems for use in wind tunnels. The arrangement is generally chronological by date of publication. However, papers presented at conferences or meetings are placed under dates of presentation. The numbers assigned to many of the citations have been changed from those used in the previous bibliography. This has been done in order to allow outdated citations to be removed and some recently discovered older works to be included in their proper chronological order

SAP97 and Cortactin Remodeling in Arrhythmogenic Purkinje Cells

Because structural remodeling of several proteins, including ion channels, may underlie the abnormal action potentials of Purkinje cells (PCs) that survive in the 48 hr infarcted zone of the canine heart (IZPCs), we sought to determine the subcellular structure and function of the KV1.5 (KCNA5) protein in single IZPCs. Clustering of the Kv1.5 subunit in axons is regulated by a synapse-associated protein, SAP97, and is linked to an actin-binding protein, cortactin, and an intercellular adhesion molecule, N-cadherin. To understand the functional remodeling of the Kv1.5 channel and its regulation in IZPCs, Kv1.5 currents in PCs were measured as the currents blocked by 10 µM RSD1379 using patch-clamp techniques. Immunocytochemistry and confocal imaging were used for both single and aggregated IZPCs vs normal PCs (NZPCs) to determine the relationship of Kv1.5 with SAP-97, cortactin and N-cadherin. In IZPCs, both the sarcolemma (SL) and intercalated disk (ID) Kv1.5 protein are abundant, and the amount of cytosolic Kv1.5 protein is greatly increased. SAP-97 is also increased at IDs and has notable cytosolic localization suggesting that SAP-97 may regulate the functional expression and stabilization of Kv1.5 channels in IZPCs. Cortactin, which is located with N-cadherin at IDs in NZPCs, remains at IDs but begins to dissociate from N-cadherin, often forming ring structures and colocalizing with Kv1.5 within IZPCs. At the same time, cortactin/Kv1.5 colocalization is increased at the ID, suggesting an ongoing active process of membrane trafficking of the channel protein. Finally, the Kv1.5 current, measured as the RSD1379-sensitive current, at +40 mV did not differ between NZPCs (0.81±0.24 pA/pF, n = 14) and IZPCs (0.83±0.21 pA/pF, n = 13, NS). In conclusion, the subcellular structural remodeling of Kv1.5, SAP97 and cortactin maintained and normalized the function of the Kv1.5 channel in Purkinje cells that survived myocardial infarction

Dynamic Stability Instrumentation System (DSIS). Volume 1: Hardware description

This paper is a hardware description manual for the Dynamic Stability Instrumentation System that is used in specific NASA Langley wind tunnels. The instrumentation system performs either a synchronous demodulation or a fast Fourier transform on dynamic balance strain gage signals, and ultimately computes aerodynamic coefficients. The DSIS consists of a double rack of instruments, a remote motor-generator set, two special stings each with motor driven shafts, and specially designed balances. The major components in the instrumentation rack include a personal computer, digital signal processor microcomputers, computer-controlled signal conditioners, function generator, digital multimeter, and an optional fast Fourier transform analyzer

Dynamic Stability Instrumentation System (DSIS)

The paper is an operating manual for the Dynamic Stability Instrumentation System in specific NASA Langley wind tunnels. The instrumentation system performs either a synchronous demodulation or a Fast Fourier Transform on dynamic balance strain gage signals, and ultimately computes aerodynamic coefficients. The dynamic balance converts sting motor rotation into pitch or yaw plane or roll axis oscillation, with timing information provided by a shaft encoder. Additional instruments control model attitude and balance temperature and monitor sting vibrations. Other instruments perform self-calibration and diagnostics. Procedures for conducting calibrations and wind-off and wind-on tests are listed

New datings and elevations of a fossil reef in Lembetabe, southwest Madagascar: eustatic and tectonic implications

The study of geological sea-level proxies formed during previous interglacials is a common approach to assess how global sea level will evolve under warmer climate conditions. Over the last decades, technical advancements in both survey and geochronology have allowed improving our knowledge of past sea-level highstands. This is of prime importance to refine our understanding of processes contributing to sea-level changes, and ultimately to improve both local and global sea-level projections. Last Interglacial sea-level proxies in the Western Indian Ocean (and more specifically the island nation of Madagascar), have been less investigated than in other intertropical oceans over the last decades. As a result, paleo sea-level data in this region are less abundant and less precise than elsewhere. Here, we report the results of two field campaigns aimed at studying the site of Lembetabe, southwest Madagascar, where a fossil reef was first described by the researcher Rene ⠁ Battistini more than 50 years ago. We estimate paleo relative sea level history in space and time from 15 new U-series ages from a fossil reef platform mapped with differential GNSS and drone photogrammetry. Our data suggest that, between 129 ka and 115 ka, paleo relative sea level at this location was about 3.4 & PLUSMN; 1.4 m above modern. Once corrected for glacial isostatic adjustment, we find that paleo global mean sea level did not exceed 3 m above modern. Only slight crustal subsidence would reconcile the peak Last Interglacial sea level measured at Lembetabe with the 5 e10 m range reported in the literature.& COPY; 2023 Published by Elsevier Ltd