The Langley tunable diode laser instrument package incorporated an additional channel to measure nitrous oxide (N2O) during the Pacific Exploratory Mission (PEM) West A. These measurements represent ...the first airborne, fast response (5‐s) N2O data set obtained within the troposphere. Most data were recorded over the western Pacific between 0°N and 45°N latitude, 110°E and 180°E longitude, and 0.3 to 12 km altitude. Important observations include a decreasing N2O latitude gradient of approximately 0.4 parts per billion volume (ppbv) from northern midlatitudes to the equator, a decreasing N2O longitude gradient of 0.4 ppbv from the western Pacific to the central Pacific at northern midlatitudes, and an enhancement of 0.2 ppbv in the boundary layer (altitudes below 0.5 km) relative to the rest of the tropospheric vertical profile. Other observations include increased N2O mixing ratios within both urban and biogenic affected air masses and reduced N2O mixing ratios in stratospheric intrusions. These relationships with air mass source characteristics are exhibited in the large‐scale correlations between N2O and CO, CH4, and CO2 in the free troposphere. Atmospheric inputs of N2O are examined and the relative strengths of continental biogenic and anthropogenic/industrial sources are estimated. The data set is also examined for evidence of an oceanic source of N2O.
The gas composition of the air cell in a shell egg is influenced by heating from egg washing and candling and the method of cooling and storage. This study found that N2 gas (-122 C), CO2 gas (-45 ...C), and cold air (-15 C) could be used to rapidly cool shell eggs from 47.7 C to 7 C in 30 min or less. These results suggest that the gas composition of the air cell in shell eggs can be significantly modified using N2 cooling and CO2 cooling. Commercial field studies have shown that these modifications, which take place during cryogenic cooling, can significantly reduce microbial levels and increase shelf life of shell eggs. Storage in a modified atmosphere environment further enhanced these changes. It was found that the CO2 concentration in the air cell of a shell egg can be increased from 0.04 to 48% by CO2 cooling and storage in a CO2 environment.
Background. Some studies have linked low serum cholesterol levels to increased risk of colon cancer, particularly in men. Results have been inconsistent, with pre‐clinical disease frequently offered ...to explain any apparent association.
Methods. The Framingham Study cohort of 5209 persons, initially 30‐62 years of age and observed more than 30 years, was evaluated. Baseline data included lipoprotein fractions, total cholesterol levels, body mass index, alcohol intake, and cardiovascular risk variables such as cigarette smoking, hypertension, and glucose intolerance.
Results. In this population, colon cancer in men is related inversely to serum cholesterol levels, even when the first 10 years of follow‐up are eliminated to reduce the effect of preclinical disease. This effect is concentrated in the Svedberg 0‐20 fraction, corresponding to low‐density lipoprotein levels. Another finding only in men is the direct relation of body mass index to colon cancer incidence.
Conclusions. Combined initial low serum cholesterol levels and obesity appear to indicate a four times greater risk for colon cancer in men as compared with people with average values of both variables. The reasons for these observations are unknown.
Anxiety disorders are the most common class of psychopathology among youth, yet many of these youngsters do not receive treatment. This is particularly concerning given the chronic course of anxiety ...disorders, which often lead to mood disorders, substance abuse, and serious impairment. Schools are an optimal venue for identifying anxious students and delivering mental health treatment given access to youth and ability to overcome various barriers to treatment. This article reviews four school-based treatments for anxiety disorders that have been evaluated in controlled trials. Discussion centers on feasibility, challenges to school-based implementation, and future research directions for this critical area.
P. A. Deuster, E. Dolev, S. B. Kyle, R. A. Anderson and E. B. Schoomaker
This study was conducted to determine whether short-term, high-intensity
anaerobic exercise alters Mg homeostasis. Thirteen ...men performed
intermittent bouts of treadmill running at 90% of their predetermined
maximum O2 uptake until exhaustion on one occasion during a week in which
all men were consuming a standard diet (115 mg Mg/1,000 kcal). Plasma and
erythrocyte Mg concentrations and peripheral blood mononuclear cell Mg
content were measured before and after the exercise. Complete 24-h urine
collections were obtained on control days, on the day of exercise, and on
the day after exercise. Exercise induced a transient but significant
decrease in plasma Mg content (-6.8%; P less than 0.01); over 85% of the
loss could be accounted for by a shift to the erythrocytes. Significant
increases in urinary excretion of Mg were observed on the day of exercise
(131.5 +/- 6.8 mg/day) compared with control days (108 +/- 6.6 mg/day),
with the percent increase correlating with postexercise blood lactate
concentration (r = 0.68; P less than 0.01) and oxygen consumption during
recovery (r = 0.84; P less than 0.001). The data indicate that
high-intensity anaerobic exercise induces intercompartmental Mg shifts in
blood that return to preexercise values within 2 h and urinary losses on
the day of exercise that return to base line the day after exercise. It is
postulated that the exercise-induced increase in Mg excretion may depend on
the intensity of the exercise, and the relative contribution of anaerobic
metabolism to the total energy expended during exercise.
Effects of chronic ethanol treatment (CET) on muscarinic acetylcholine receptor (mAChR) binding properties were investigated via quantitative autoradiography in rats maintained on an ...ethanol-containing liquid diet for 28 weeks and withdrawn from ethanol for 8 weeks before harvesting of tissues. Controls received an identical diet in which sucrose was substituted isocalorically for ethanol. Maximal binding of the radiolabeled mAChR antagonist quinuclidinyl benzilate (3HQNB) was not reduced in hippocampal area CA1, dentate gyrus, neocortex, striatum, or thalamus, suggesting that CET results in no significant mAChR loss in these regions. Binding affinities of the cholinergic agonist carbachol to mAChRs were unaffected by CET in each of these regions, as determined by competitive displacement of 3HQNB labeling. These results suggest that CET-induced functional deficits in brain cholinergic responses are not due to direct effects of CET on mAChR binding properties.
We present the confirmation of a new sub-Neptune close to the transition between super-Earths and sub-Neptunes transiting the M2 dwarf TOI- 269 (TIC 220479565, V = 14.4 mag, J = 10.9 mag, Rstar = ...0.40 Rsun, Mstar = 0.39 Msun, d = 57 pc). The exoplanet candidate has been identified in multiple TESS sectors, and validated with high-precision spectroscopy from HARPS and ground-based photometric follow-up from ExTrA and LCO-CTIO. We determined mass, radius, and bulk density of the exoplanet by jointly modeling both photometry and radial velocities with juliet. The transiting exoplanet has an orbital period of P = 3.6977104 +- 0.0000037 days, a radius of 2.77 +- 0.12 Rearth, and a mass of 8.8 +- 1.4 Mearth. Since TOI-269 b lies among the best targets of its category for atmospheric characterization, it would be interesting to probe the atmosphere of this exoplanet with transmission spectroscopy in order to compare it to other sub-Neptunes. With an eccentricity e = 0.425+0.082-0.086, TOI-269 b has one of the highest eccentricities of the exoplanets with periods less than 10 days. The star being likely a few Gyr old, this system does not appear to be dynamically young. We surmise TOI-269 b may have acquired its high eccentricity as it migrated inward through planet-planet interactions.
Exhaust measurements in the wake vortex regime of the NASA Boeing 757 aircraft were made during the SUbsonic aircraft: Contrails and Cloud Effects Special Study. Emission indices for NO and NOy were ...calculated from in situ measurements taken on board the NASA DC‐8 for plumes aged 20–300 seconds. The average NO emission index is 7.5 g NO2/kg fuel for mean conditions of 37 kft altitude, 0.7 Mach and 0.34 kg/s fuel flow rate. Comparison is made between measured indices and predictions based on ground engine test data and a fuel flow model. Measurements are positively correlated but are on average 22% higher than predictions, with considerable scatter and systematic deviations in measurements made under low thrust conditions. These conditions are lower than typical in commercial cruise operation of the 757, for which the model was optimized. No statistically significant change in nitrogenous emissions is observed for an order of magnitude change in fuel sulfur content. Estimation of the NO2 from photochemical calculations implies a contribution to NOx of 5–19%. Examination of exhaust composition shows that 95% of the NOy is in the form of NOx.
Homogeneous preparations of milligram quantities of RNA are a prerequisite for their characterization by biophysical methods such as crystallography or NMR spectroscopy. Methods for obtaining ...milligram quantities of pure synthetic RNA are described in this paper. These methods employ anion exchange HPLC for purifying full-length sequence from failure sequences and incompletely deprotected material. RNA molecules with little or extensive amounts of secondary structure could be purified. In cases where the RNA molecule was tightly folded, the cation in the eluent buffer influenced both the distinction of the peaks during chromatography and the final folded conformation. Finally, two RNA sequences were chemically synthesized, deprotected, purified, and crystallized using this methodology.
Geochronology, or determination of absolute ages for geologic events, underpins many inquiries into the formation and evolution of planets and our Solar System. Absolute ages of ancient and recent ...magmatic products provide strong constraints on the dynamics of magma oceans and crustal formation, as well as the longevity and evolution of interior heat engines and distinct mantle/crustal source regions. Absolute dating also relates habitability markers to the timescale of evolution of life on Earth. However, the number of geochronologically-significant terrains across the inner Solar System far exceeds our ability to conduct sample return from all of them. In preparation for the upcoming Decadal Survey, our team formulated a set of medium-class (New Frontiers) mission concepts to three different locations (the Moon, Mars, and Vesta) where sites that record Solar System bombardment, magmatism, and/or habitability are uniquely preserved and accessible. We developed a notional payload to directly date planetary surfaces, consisting of two instruments capable of measuring radiometric ages in situ, an imaging spectrometer, optical cameras to provide site geologic context and sample characterization, a trace element analyzer to augment sample contextualization, and a sample acquisition and handling system. Landers carrying this payload to the Moon, Mars, and Vesta would likely fit into the New Frontiers cost cap in our study (~$1B). A mission of this type would provide crucial constraints on planetary history while also enabling a broad suite of investigations such as basic geologic characterization, geomorphologic analysis, ground truth for remote sensing analyses, analyses of major, minor, trace, and volatile elements, atmospheric and other long-lived monitoring, organic molecule analyses, and soil and geotechnical properties.
PDF
