Exploring the Origins of Earth's Nitrogen: Astronomical Observations of Nitrogen-bearing Organics in Protostellar Environments

It is not known whether the original carriers of Earth's nitrogen were molecular ices or refractory dust. To investigate this question, we have used data and results of Herschel observations towards two protostellar sources: the high-mass hot core of Orion KL, and the low-mass protostar IRAS 16293-2422. Towards Orion KL, our analysis of the molecular inventory of Crockett et al. (2014) indicates that HCN is the organic molecule that contains by far the most nitrogen, carrying $74_{-9}^{+5}\%$ of nitrogen-in-organics. Following this evidence, we explore HCN towards IRAS 16293-2422, which we consider a solar analog. Towards IRAS 16293-2422, we have reduced and analyzed Herschel spectra of HCN, and fit these observations against "jump" abundance models of IRAS 16293-2422's protostellar envelope. We find an inner-envelope HCN abundance $X_{\textrm{in}} = 5.9\pm0.7 \times 10^{-8}$ and an outer-envelope HCN abundance $X_{\textrm{out}} = 1.3 \pm 0.1 \times 10^{-9}$. We also find the sublimation temperature of HCN to be $T_{\textrm{jump}} = 71 \pm 3$~K; this measured $T_{\textrm{jump}}$ enables us to predict an HCN binding energy $E_{\textrm{B}}/k = 3840 \pm 140$~K. Based on a comparison of the HCN/H2O ratio in these protostars to N/H2O ratios in comets, we find that HCN (and, by extension, other organics) in these protostars is incapable of providing the total bulk N/H2O in comets. We suggest that refractory dust, not molecular ices, was the bulk provider of nitrogen to comets. However, interstellar dust is not known to have 15N enrichment, while high 15N enrichment is seen in both nitrogen-bearing ices and in cometary nitrogen. This may indicate that these 15N-enriched ices were an important contributor to the nitrogen in planetesimals and likely to the Earth.Comment: Accepted to ApJ; 21 pages, 4 figure

Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders

As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (\u3c 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales

Methods for Collecting and Using Backscatter Field Calibration Information for the Reson 7000 Series Multibeams

In support of Integrated Ocean and Coastal Mapping, the National Oceanic and Atmospheric Administration’s (NOAA) Office of Coast Survey collects meaningful acoustic backscatter as a ancillary product of its navigational charting mission. Many of NOAA’s field units have Reson 7000 series multibeam echosounders which have been shown to have decidedly non-linear response characteristics under certain high signal conditions. This non-linear behavior significantly increases the complexity of the radiometric corrections required to make use of backscatter under a variety of processing paradigms. Avoiding operating these systems in the non-linear operational domain is a simpler approach. However, the onset of non-linear behavior is not a simple function of the output signal level but instead depends on a number of tunable settings. Here we present a method for both determining the onset of non-linear behavior in any installed Reson 7000 series sonar and monitoring the system during real-time acquisition to ensure the system is operating in a linear fashion. In general this information improves the operator’s understanding of the system status and can lead to additional post processing advantages

Anomalous Electrical Resistivity of Barely Delocalized Electrons

We observe a maximum near 200 K in the zero frequency resistivity of Si:P doped et about twice the Mott density and in the dirty metal limit where the Fermi wave vector times the mean free path is of order 1 . The peak indicates a strong T-variation of the screening length, but the T-behavior down to 40 mK shows no evidence of the resistivity minimum predicted for a three-dimensional metal with interference between electron-electron and electron-impurity scattering

Antibody glycosylation in pregnancy and in newborns: biological roles and implications.

PURPOSE OF REVIEW: Glycosylation patterns have the potential to affect the function of antibody, antibody half-life and transplacental transfer from mother to foetus. Here, we review recent advances in our understanding of how glycosylation patterns of antibodies may be altered during pregnancy, vaccination and infection. RECENT FINDINGS: During pregnancy, there is preferential transplacental transfer of natural killer (NK) cell-activating antibodies that are galactosylated and sialylated, against both bacterial and viral antigens. Markers of NK cell function are also associated with a higher abundance of galactosylation and sialylation in respiratory syncytial virus-specific IgG, compared with total IgG, in infants up to 7 months of age which may suggest a role for NK-cell activating antibodies as important mediators of immunity during early infancy. Differential glycosylation patterns have been observed in some respiratory conditions, as increased nongalactosylated antibodies have been associated with the development of chronic inflammatory bronchopulmonary dysplasia (BPD) in preterm infants. Glycosylation patterns in children appear age-dependent, which could modulate the effector function of IgG. The clinical relevance of these findings needs to be established. SUMMARY: Glycosylation plays a key role in mediating antibody function. Glycosylation patterns associated with positive outcomes from infection in mothers and infants could inform the design of the next generation of vaccines for use in pregnancy and infancy. SDC VIDEO LINK:: http://links.lww.com/COID/A29

Exploring Underserved Communities’ Perspectives on Wilderness Character in Everglades National Park

Issues related to diversity, equity, and inclusion are becoming increasingly important to park and protected area managers. Recently, several Executive Orders have established policies and priorities for steering public lands to better serve the diversity of the US public. Certain groups, compared to the US population at large, are underrepresented as visitors to parks and protected areas in the US, including BIPOC communities (Black, Indigenous, and other People of Color), women, people with disabilities, veterans, people with lower socioeconomic status, and the elderly. This disparity in visitation may be even more pronounced in federally designated wilderness areas. We present a qualitative study focused on the relationships of traditionally underserved groups with Everglades National Park, specifically focusing on perceptions of wilderness character in the Marjory Stoneman Douglas Wilderness. Findings illuminate both perceived benefits of wilderness, including positive mental health, ecosystem services, and a connection to unique aspects of wilderness character in the Everglades, as well as conflicted feelings about wilderness as a place that underemphasizes historic interactions of underrepresented communities with the landscape. We discuss management implications, particularly ways to focus protected area efforts to broaden the relevancy of wilderness lands and better serve diverse populations within local communities

Observation and analysis of in situ carbonaceous matter in Nakhla: Part I

New analyses of indigenous secondary material in the martian meteorite Nakhla reveal amorphous carbon-rich veins and dendrites. The texture and chemistry of this material resembles that of biogenically altered sub-ocean basaltic glasses

Optimal control of atom transport for quantum gates in optical lattices

By means of optimal control techniques we model and optimize the manipulation of the external quantum state (center-of-mass motion) of atoms trapped in adjustable optical potentials. We consider in detail the cases of both non interacting and interacting atoms moving between neighboring sites in a lattice of a double-well optical potentials. Such a lattice can perform interaction-mediated entanglement of atom pairs and can realize two-qubit quantum gates. The optimized control sequences for the optical potential allow transport faster and with significantly larger fidelity than is possible with processes based on adiabatic transport.Comment: revised version: minor changes, 2 references added, published versio

Observation and analysis of in situ carbonaceous matter in Nakhla: part II

Analysis of in situ carbonaceous matter in the Nakhla SNC meteorite has been carried out using a variety of techniques. Laser raman data shows the carbonaceous matter to be highly complex and static mass spectrometry has shown it to have an isotopic composition of '18 to '20' C