•LEND on LRO detects diurnally varying suppression of epithermal neutron flux near the Moon’s equator.•Neutron suppression is consistent with presence of H-bearing volatiles.•Peak inferred hydrogen ...concentration is near dawn terminator, minimum at dusk.•Most likely source of volatiles is outgassing of a primordial inventory from the Moon.•Natural distillation by sunlight may provide energy-efficient access to water and other volatiles.
The Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft, has detected suppression in the Moon’s naturally-occurring epithermal neutron leakage flux that is consistent with the presence of diurnally varying quantities of hydrogen in the regolith near the equator. Peak hydrogen concentration (neutron flux suppression) is on the dayside of the dawn terminator and diminishes through the dawn-to-noon sector. The minimum concentration of hydrogen is in the late afternoon and dusk sector. The chemical form of hydrogen is not determinable from these measurements, but other remote sensing methods and anticipated elemental availability suggest water molecules or hydroxyl ions. Signal-to-noise ratio at maximum contrast is 5.6σ in each of two detector systems. Volatiles are deduced to collect in or on the cold nightside surface and distill out of the regolith after dawn as rotation exposes the surface to sunlight. Liberated volatiles migrate away from the warm subsolar region toward the nearby cold nightside surface beyond the terminator, resulting in maximum concentration at the dawn terminator. The peak concentration within the upper ∼1m of regolith is estimated to be 0.0125±0.0022 weight-percent water-equivalent hydrogen (wt% WEH) at dawn, yielding an accumulation of 190±30ml recoverable water per square meter of regolith at each dawn. Volatile transport over the lunar surface in opposition to the Moon’s rotation exposes molecules to solar ultraviolet radiation. The short lifetime against photolysis and permanent loss of hydrogen from the Moon requires a resupply rate that greatly exceeds anticipated delivery of hydrogen by solar wind implantation or by meteoroid impacts, suggesting that the surface inventory must be continually resupplied by release from a deep volatile inventory in the Moon. The natural distillation of water from the regolith by sunlight and its capture on the cold night surface may provide energy-efficient access to volatiles for in situ resource utilization (ISRU) by direct capture before volatiles can enter the surface, eliminating the need to actively mine regolith for volatile resource recovery.
The coronavirus disease 2019 (COVID-19) is accompanied by a cytokine storm with the release of many proinflammatory factors and development of respiratory syndrome. Several SARS-CoV-2 lineages have ...been identified, and the Delta variant (B.1.617), linked with high mortality risk, has become dominant in many countries. Understanding the immune responses associated with COVID-19 lineages may therefore aid the development of therapeutic and diagnostic strategies. Multiple single-cell gene expression studies revealed innate and adaptive immunological factors and pathways correlated with COVID-19 severity. Additional investigations covering host–pathogen response characteristics for infection caused by different lineages are required. Here, we performed single-cell transcriptome profiling of blood mononuclear cells from the individuals with different severity of the COVID-19 and virus lineages to uncover variant specific molecular factors associated with immunity. We identified significant changes in lymphoid and myeloid cells. Our study highlights that an abundant population of monocytes with specific gene expression signatures accompanies Delta lineage of SARS-CoV-2 and contributes to COVID-19 pathogenesis inferring immune components for targeted therapy.
Bronchial asthma (BA) is a disease that still lacks an exhaustive treatment protocol. In this regard, the global medical community pays special attention to the genetic prerequisites for the ...occurrence of this disease. Therefore, the search for the genetic polymorphisms underlying bronchial asthma has expanded considerably. As the present study progressed, a significant amount of scientific medical literature was analyzed and 167 genes reported to be associated with the development of bronchial asthma were identified. A group of participants (n = 7,303) who had voluntarily provided their biomaterial (venous blood) to be used in the research conducted by the Federal Medical Biological Agency of Russia was formed to subsequently perform a bioinformatic verification of known associations and search for new ones. This group of participants was divided into four cohorts, including two sex-distinct cohorts of individuals with a history of asthma and two sex-distinct cohorts of apparently healthy individuals. A search for polymorphisms was made in each cohort among the selected genes, and genetic variants were identified whose difference in occurrence in the different cohorts was statistically significant (significance level less than 0.0001). The study revealed 11 polymorphisms that affect the development of asthma: four genetic variants (rs869106717, rs1461555098, rs189649077, and rs1199362453), which are more common in men with bronchial asthma compared to apparently healthy men; five genetic variants (rs1923038536, rs181066119, rs143247175, rs140597386, and rs762042586), which are more common in women with bronchial asthma compared to apparently healthy women; and two genetic variants (rs1219244986 and rs2291651) that are rare in women with a history of asthma.
This paper presents the methods of soil parameter estimation from neutron probing data that are used when processing the data from the DAN experiment on the Martian surface. We discuss the data ...preprocessing steps that enable us to compare experimental data to a Monte-Carlo numerical model, algorithms used to estimate equivalent water and chlorine content for standard soil composition and to dynamically analyse the soil parameters in non-standard cases. We also provide the water and chlorine content estimates and compare them with the SAM experiment data.
GRB 051103 is considered to be a candidate soft gamma repeater (SGR) extragalactic giant magnetar flare by virtue of its proximity on the sky to M81/M82, as well as its time history, localization and ...energy spectrum. We have derived a refined interplanetary network localization for this burst which reduces the size of the error box by over a factor of 2. We examine its time history for evidence of a periodic component, which would be one signature of an SGR giant flare, and conclude that this component is neither detected nor detectable under reasonable assumptions. We analyse the time-resolved energy spectra of this event with improved time and energy resolution, and conclude that although the spectrum is very hard its temporal evolution at late times cannot be determined, which further complicates the giant flare association. We also present new optical observations reaching limiting magnitudes of R > 24.5, about 4-mag deeper than previously reported. In tandem with serendipitous observations of M81 taken immediately before and 1 month after the burst, these place strong constraints on any rapidly variable sources in the region of the refined error ellipse proximate to M81. We do not find any convincing afterglow candidates from either background galaxies or sources in M81, although within the refined error region we do locate two UV bright star-forming regions which may host SGRs. A supernova remnant (SNR) within the error ellipse could provide further support for an SGR giant flare association, but we were unable to identify any SNR within the error ellipse. These data still do not allow strong constraints on the nature of the GRB 051103 progenitor, and suggest that candidate extragalactic SGR giant flares will be difficult, although not impossible, to confirm.
•Concentrations of hydrogen-bearing volatiles are biased towards the Moon's southern pole-facing slopes.•Pole-facing slopes are being hydrated in a continuum of spatial scales, perhaps approaching ...the level of a meter scale.•Pole-facing slopes are acting as local "cool-traps" that accumulate hydrogen outside of permanently shadowed regions.•The poleward hydration of pole-facing slopes as detected by neutron methods begins near 50°S.•The upper-bound temperature for the entrainment of hydrogen in regolith is ∼135K.
The Lunar Exploration Neutron Detector (LEND) onboard the Lunar Reconnaissance Orbiter (LRO) detects a widespread suppression of the epithermal neutron leakage flux that is coincident with the pole-facing slopes (PFS) of the Moon’s southern hemisphere. Suppression of the epithermal neutron flux is consistent with an interpretation of enhanced concentrations of hydrogen-bearing volatiles within the upper meter of the regolith. Localized flux suppression in PFS suggests that the reduced solar irradiation and lowered temperature on PFS constrains volatility to a greater extent than in surrounding regions. Epithermal neutron flux mapped with LEND’s Collimated Sensor for Epithermal Neutrons (CSETN) was analyzed as a function of slope geomorphology derived from the Lunar Orbiting Laser Altimeter (LOLA) and the results compared to co-registered maps of diurnally averaged temperature from the Diviner Lunar Radiometer Experiment and an averaged illumination map derived from LOLA. The suppression in the average south polar epithermal neutron flux on equator-facing slopes (EFS) and PFS (85–90°S) is 3.3±0.04% and 4.3±0.05% respectively (one-sigma-uncertainties), relative to the average count-rate in the latitude band 45–90°S. The discrepancy of 1.0±0.06% between EFS and PFS neutron flux corresponds to an average of ∼23parts-per-million-by-weight (ppmw) more hydrogen on PFS than on EFS. Results show that the detection of hydrogen concentrations on PFS is dependent on their spatial scale. Epithermal flux suppression on large scale PFS was found to be enhanced to 5.2±0.13%, a discrepancy of ∼45ppmw hydrogen relative to equivalent EFS. Enhanced poleward hydration of PFS begins between 50°S and 60°S latitude. Polar regolith temperature contrasts do not explain the suppression of epithermal neutrons on pole-facing slopes. The Supplemental on-line materials include supporting results derived from the uncollimated Lunar Prospector Neutron Spectrometer and the LEND Sensor for Epithermal Neutrons.
This paper presents estimates of the water and chlorine contents in the subsurface of Gale crater based on the measurements by the Dynamic Albedo of Neutrons (DAN) instrument onboard the NASA ...Curiosity rover. It is Part 1 of a two‐paper series. Data derived both from DAN active and passive measurements are presented in discrete surface areas (pixels) assuming a homogeneous distribution of water within the DAN sensing depth (60 cm) along the traverse of the rover. It is shown that the content of hydrogen, reported as Water Equivalent Hydrogen, varies between almost zero and a maximum of (6.1 ± 0.7) wt.%. The content of absorption equivalent chlorine varies between almost zero and (2.6 ± 0.2) wt.%. Such variations are thought to be related to the different geological processes and environmental conditions present in the strata along the traverse during the evolutionary history of Gale crater. The second paper (Part 2) studies particular properties of water and abundances of neutron absorbing elements at distinct geological regions, that the rover crossed on its way.
Plain Language Summary
The Dynamic Albedo of Neutrons (DAN) is a neutron spectrometer that searches for signs of water by measuring the content of neutron absorbing elements in the ground below the NASA's Curiosity rover. Data derived from DAN are presented in discrete pixels along the traverse of the rover. Each pixel contains estimations of water equivalent hydrogen (WEH) and absorption equivalent chlorine (AEC) content from neutron sensing. DAN observations were combined into the two types of 3 × 3 m pixels: Pixel with Active Data includes WEH and AEC content and Pixel of Passive Data includes WEH content. Each pixel has been assigned to the associated geological member of the Mars Science Laboratory stratigraphic column. Full DAN data volume for 27 km of the traverse were formatted as a table with more than 10,000 pixels. The large fraction of stratigraphic members (Bradbury, Pahrump Hills and others) have the mean WEH values between 2 and 3 wt.%, while other members of the second part of the traverse (Jura, Knockfarrill Hill, Glasgow, Pontours) have the mean values of WEH above 3 wt.%. Mean AEC value has no large variations for all tested stratigraphic members; it is equal to around 1 wt.% for the majority of the pixels.
Key Points
Dynamic Albedo of Neutrons (DAN) neutron sensing data were analyzed for 27 km of the Curiosity rover traverse
DAN data were derived as single pixels and associated with the Gale crater stratigraphic column divisions
DAN measurements indicate area with maximum water content of (6.1 ± 0.7) wt.%
A significant difference in the growth mechanism of spatially closed structures of gallium nitride during selective growth in submicron windows with and without penetration into the GaN sublayer was ...demonstrated. The mechanisms of generation and development of dislocations, their role in the formation of self-organizing coaxial structures were modeled.
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