Estimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic ...carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH₄), at forests, grasslands, and croplands across Europe. Biogenic contributions to DIC were estimated by means of its δ¹³C signature. Leaching of biogenic DIC was 8.3±4.9 g m⁻² yr⁻¹ for forests, 24.1±7.2 g m⁻² yr⁻¹ for grasslands, and 14.6±4.8 g m⁻² yr⁻¹ for croplands. DOC leaching equalled 3.5±1.3 g m⁻² yr⁻¹ for forests, 5.3±2.0 g m⁻² yr⁻¹ for grasslands, and 4.1±1.3 g m⁻² yr⁻¹ for croplands. The average flux of total biogenic carbon across land use systems was 19.4±4.0 g C m⁻² yr⁻¹. Production of DOC in topsoils was positively related to their C/N ratio and DOC retention in subsoils was inversely related to the ratio of organic carbon to iron plus aluminium (hydr)oxides. Partial pressures of CO₂ in soil air and soil pH determined DIC concentrations and fluxes, but soil solutions were often supersaturated with DIC relative to soil air CO₂. Leaching losses of biogenic carbon (DOC plus biogenic DIC) from grasslands equalled 5-98% (median: 22%) of net ecosystem exchange (NEE) plus carbon inputs with fertilization minus carbon removal with harvest. Carbon leaching increased the net losses from cropland soils by 24-105% (median: 25%). For the majority of forest sites, leaching hardly affected actual net ecosystem carbon balances because of the small solubility of CO₂ in acidic forest soil solutions and large NEE. Leaching of CH₄ proved to be insignificant compared with other fluxes of carbon. Overall, our results show that leaching losses are particularly important for the carbon balance of agricultural systems.
The SPHEREx Target List of Ice Sources (SPLICES) Ashby, Matthew L. N.; Hora, Joseph L.; Lakshmipathaiah, Kiran ...
Astrophysical journal/The Astrophysical journal,
06/2023, Letnik:
949, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Abstract
One of the primary objectives of the SPHEREx mission is to understand the origin of molecules such as H
2
O, CO
2
, and other volatile compounds at the early stages of planetary system ...formation. Because the vast majority of these compounds—typically exceeding 95%—exist in the solid phase rather than the gaseous phase in the systems of concern here, the observing strategy planned to characterize them is slightly unusual. Specifically, SPHEREx will target highly obscured sources throughout the Milky Way, and observe the species of concern in absorption against background illumination. SPHEREx spectrophotometry will yield ice column density measurements for millions of obscured Milky Way sources of all ages and types. By correlating those column densities with source ages, the SPHEREx mission will shed light on whether those molecules were formed in situ along with their nascent stellar systems, or whether instead they formed elsewhere and were introduced into those systems after their formation. To that end, this work describes version 7.1 of the SPHEREx target List of ICE
Sources (SPLICES) for the community. It contains 8.6 × 10
6
objects brighter than
W
2 ∼ 12 Vega mag over much of the sky, principally within a broad strip running the length of the Milky Way midplane, but also within high-latitude molecular clouds and even the Magellanic Clouds.
Proteome and transcriptome analyses aim at comprehending the molecular profiles of the brain, its cell-types and subcellular compartments including myelin. Despite the relevance of the peripheral ...nervous system for normal sensory and motor capabilities, analogous approaches to peripheral nerves and peripheral myelin have fallen behind evolving technical standards. Here we assess the peripheral myelin proteome by gel-free, label-free mass-spectrometry for deep quantitative coverage. Integration with RNA-Sequencing-based developmental mRNA-abundance profiles and neuropathy disease genes illustrates the utility of this resource. Notably, the periaxin-deficient mouse model of the neuropathy Charcot-Marie-Tooth 4F displays a highly pathological myelin proteome profile, exemplified by the discovery of reduced levels of the monocarboxylate transporter MCT1/SLC16A1 as a novel facet of the neuropathology. This work provides the most comprehensive proteome resource thus far to approach development, function and pathology of peripheral myelin, and a straightforward, accurate and sensitive workflow to address myelin diversity in health and disease.
Trends in Silicates in the β Pictoris Disk Lu, Cicero X.; Chen, Christine H.; Sargent, B. A. ...
Astrophysical journal/The Astrophysical journal,
07/2022, Letnik:
933, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
While
β
Pic is known to host silicates in ring-like structures, whether the properties of these silicate dust vary with stellocentric distance remains an open question. We re-analyze the
β
...Pictoris debris disk spectrum from the Spitzer Infrared Spectrograph (IRS) and a new Infrared Telescope Facility Spectrograph and Imager spectrum to investigate trends in Fe/Mg ratio, shape, and crystallinity in grains as a function of wavelength, a proxy for stellocentric distance. By analyzing a re-calibrated and re-extracted spectrum, we identify a new 18
μ
m forsterite emission feature and recover a 23
μ
m forsterite emission feature with a substantially larger line-to-continuum ratio than previously reported. We find that these prominent spectral features are primarily produced by small submicron-sized grains, which are continuously generated and replenished from planetesimal collisions in the disk and can elucidate their parent bodies’ composition. We discover three trends about these small grains: as stellocentric distance increases, (1) small silicate grains become more crystalline (less amorphous), (2) they become more irregular in shape, and (3) for crystalline silicate grains, the Fe/Mg ratio decreases. Applying these trends to
β
Pic’s planetary architecture, we find that the dust population exterior to the orbits of
β
Pic b and c differs substantially in crystallinity and shape. We also find a tentative 3–5
μ
m dust excess due to spatially unresolved hot dust emission close to the star. From our findings, we infer that the surfaces of large planetesimals are more Fe-rich and collisionally processed closer to the star but more Fe-poor and primordial farther from the star.
Vega and Fomalhaut are similar in terms of mass, ages, and global debris disk properties; therefore, they are often referred to as "debris disk twins." We present Spitzer 10-35 mu m spectroscopic ...data centered at both stars and identify warm, unresolved excess emission in the close vicinity of Vega for the first time. The properties of the warm excess in Vega are further characterized with ancillary photometry in the mid-infrared and resolved images in the far-infrared and sub-millimeter wavelengths. In light of the current upper limits on the masses of planetary objects and the large gap, we discuss the possible implications for their underlying planetary architecture and suggest that multiple, low-mass planets likely reside between the two belts in Vega and Fomalhaut.
Abstract
The ∼200,000 targets monitored for photometric variability during the Kepler prime mission include the best-studied group of stars in the sky, due both to the extensive time history provided ...by Kepler and to the substantial amount of ancillary data provided by other investigators or compiled by the Kepler team. To complement this wealth of data, we surveyed the entire Kepler field using the 3.6 and 4.5
μ
m bands of the Warm Spitzer Space Telescope, obtaining photometry in both bands for almost 170,000 objects. We demonstrate relative photometric precision ranging from better than ∼1.5% for the brighter stars down to slightly greater than ∼2% for the faintest stars monitored by Kepler. We describe the data collection and analysis phases of this work and identify several stars with large infrared excess, although none that is also known to be the host of an exoplanetary system. The final catalog resulting from this work will be available at the NASA Exoplanet Archive.
To determine relevant Fc-gamma receptor (FcγR) polymorphisms in relation to susceptibility to SLE and LN, and to determine the functional consequences of genetic associations found.
Using multiplex ...ligation-dependent probe amplification, copy number regions (CNRs) and relevant known functional single nucleotide polymorphisms of FcγRII and FcγRIII were determined in a LN-enriched cohort of 266 Dutch Caucasian SLE patients and 919 healthy Caucasian controls. Expression of FcγRs on leukocytes was assessed using flow cytometry.
In multivariable analysis, low copy number of CNR1 (including FCGR3B; odds ratio (OR) 2.04; 95% CI: 1.29, 3.23), FCGR2A-131RR (OR 2.00; 95% CI: 1.33, 2.99), and the 2B.4 haplotype of FCGR2B (OR 1.59; 95% CI: 1.13, 2.24), but not FCGR2C open reading frame, were significantly (all P < 0.01) and independently associated with susceptibility to SLE. The 2B.4 haplotype was negatively associated with LN and led to surface expression of FcγRIIb on neutrophils and monocytes.
This study is the first to investigate the most relevant and functional single nucleotide polymorphisms and copy number variations of FcγRII and FcγRIII polymorphisms in one study population, enabling the determination of the individual contribution of each polymorphism in multivariable analysis. Three polymorphisms were shown to be independently associated with susceptibility to SLE. The novel findings of a negative association of the 2B.4 haplotype with LN, and increased expression of FcγRIIb on neutrophils and monocytes as a result of this 2B.4 haplotype warrant future research in the role of these cells and FcγRs in the pathogenesis of SLE and LN.
Autoreactive memory T lymphocytes are implicated in the pathogenesis of autoimmune diseases. Here we demonstrate that disease-associated autoreactive T cells from patients with type-1 diabetes ...mellitus or rheumatoid arthritis (RA) are mainly CD4⁺CCR7⁻CD45RA⁻ effector memory T cells ($T_{EM}$cells) with elevated Kv1.3 potassium channel expression. In contrast, T cells with other antigen specificities from these patients, or autoreactive T cells from healthy individuals and disease controls, express low levels of Kv1.3 and are predominantly naíve or central-memory ($T_{CM}$) cells. In$T_{EM}$cells, Kv1.3 traffics to the immunological synapse during antigen presentation where it colocalizes with Kvβ2, SAP97, ZIP,$p56^{Ick}$, and CD4. Although Kv1.3 inhibitors ShK(L5)-amide (SL5) and PAP1 do not prevent immunological synapse formation, they suppress Ca²⁺-signaling, cytokine production, and proliferation of autoantigen-specific$T_{EM}$cells at pharmacologically relevant concentrations while sparing other classes of T cells. Kv1.3 inhibitors ameliorate pristane-induced arthritis in rats and reduce the incidence of experimental autoimmune diabetes in diabetes-prone (DP-BB/W) rats. Repeated dosing with Kv1.3 inhibitors in rats has not revealed systemic toxicity. Further development of Kv1.3 blockers for autoimmune disease therapy is warranted.
OBJECTIVESThe aim of this study was to evaluate clinical characteristics, mechanisms of failure, and outcomes of transcatheter aortic valve replacement (TAVR) explantation. BACKGROUNDSurgical ...explantation following TAVR may be required for structural valve degeneration, paravalvular leak, infection, or other reasons. However, in-depth data on indications and outcomes are lacking. METHODSData from a multicenter, international registry (EXPLANT-TAVR) of patients who underwent TAVR explantation were reviewed retrospectively. Explantations performed during the same admission as initial TAVR were excluded. Clinical and echocardiographic outcomes were evaluated. Median follow-up duration was 6.7 months (interquartile range IQR: 1.0-18.8 months) after TAVR explantation and was 97.7% complete at 30 days and 86.1% complete at 1 year. RESULTSFrom November 2009 to September 2020, 269 patients across 42 centers with a mean age of 72.7 ± 10.4 years underwent TAVR explantation. About one quarter (25.9%) were deemed low surgical risk at index TAVR, and median Society of Thoracic Surgeons risk at TAVR explantation was 5.6% (IQR: 3.2%-9.6%). The median time to explantation was 11.5 months (IQR: 4.0-32.4 months). Balloon-expandable and self-expanding or mechanically expandable valves accounted for 50.9% and 49.1%, respectively. Indications for explantation included endocarditis (43.1%), structural valve degeneration (20.1%), paravalvular leak (18.2%), and prosthesis-patient mismatch (10.8%). Redo TAVR was not feasible because of unfavorable anatomy in 26.8% of patients. Urgent or emergency cases were performed in 53.1% of patients, aortic root replacement in 13.4%, and 54.6% had concomitant cardiac procedures. Overall survival at last follow-up was 76.1%. In-hospital, 30-day, and 1-year mortality rates were 11.9%, 13.1%, and 28.5%, respectively, and stroke rates were 5.9%, 8.6%, and 18.7%, respectively. CONCLUSIONSThe EXPLANT-TAVR registry reveals that surgical risks associated with TAVR explantation are not negligible and should be taken into consideration in the lifetime management of aortic stenosis.
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