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E. Gaidos et al, 2020, Apr��s Nous, le D��luge: A Human���Triggered J��kulhlaup From a Subglacial Lake, Geophysical Research Letters, 47, Citation number, 10.1029/2020GL089876. To view the published open abstract, go to https://doi.org/10.1029/2020GL089876. Deposited by shareyourpaper.org and openaccessbutton.org. We've taken reasonable steps to ensure this content doesn't violate copyright. However, if you think it does you can request a takedown by emailing help@openaccessbutton.org.

A primary action of vitamin D is regulation of gene transcription. Many cell types possess genes that make antimicrobial peptides (AMPS) (endogenous antibiotics), recently discovered to be regulated by vitamin D. Two examples are cathelicidin and beta defensins, both bioactive against many different bacteria, fungi, mycobacteria, parasites and viruses. The signal transduction pathway is triggered by sensing microorganisms via cell surface receptors, causing intracellular production of calcitriol (1,25(OH)2D) and vitamin D receptors, leading to upregulation of AMP production. Serum 25(OH)D concentrations required to sustain adequate AMP production to eradicate infections are unknown. Vitamin D3 is photosynthesized in skin in amounts ranging from 10,000 (250 mcg) to 25,000 (625 mcg) International Units (IU) from 7-dehydrocholesterol after whole-body exposure to one minimal erythemal dose (MED) of ultraviolet B (UVB) radiation, and is impacted by many factors including geographic localities, seasonal changes and skin pigmentation. We and others have reported extended daily oral dosing with these amounts of vitamin D3 safe. We routinely observe serum 25(OH)D concentrations below 20ng/ml on new admissions, which have been reported insufficient to sustain AMP production. In contrast serum 25(OH)D concentrations above 100ng/ml have been reported after serial UVB treatments for psoriasis. Little vitamin D naturally occurs in food, and insufficient sun exposure may be causing worldwide deficiency. We review evidence suggesting that higher daily intakes of vitamin D3 than the currently recommended 600 (15 mcg) IU/day may be necessary to sustain AMP production in the face of an overwhelming infection, particularly in non-Hispanic blacks, a high risk population suffering the worst outcomes from COVID-19. We propose that increased vitamin D supplementation could provide a safe and cost-effective way to protect all populations from infections, in particular those from pandemic COVID-19.

Amorphous orpiment-like As-sulfides (As2S3) are the most common As phases precipitating in hydrothermal systems, yet there is a lack of information regarding their solid-state characterization. Using a combination of optical, SEM-EDS, micro-Raman and XANES/EXAFS applications, we investigated yellow-orange As- and S-rich sediments occurring in the shallow-water hydrothermal system off the coast of Milos Island, Greece. The precipitates have several morphologies, but are dominantly colloidal. Intriguing "biological" morphologies also exist (e.g., cell-like (~10μm), spirals (~20μm), and rounded "cinnamon bun" shapes (~20μm)). SEM-EDS data indicated that the precipitates have an As:S ratio similar to orpiment (average=0.58, range 0.51-0.63; n=8). Micro-Raman spectra indicated that orange colored precipitates appear to be dominated by poorly crystalline and/or amorphous arsenic sulfides with micro-amounts of more crystalline orpiment and impure sulfur. The yellow sediments also contained crystalline elemental sulfur in the form S8. Bulk As K-edge XANES spectra of the As-sulfide precipitates proved a valence of As corresponding to orpiment-type (As2S3) compounds (-1 to +3). EXAFS fitting results indicated that the studied material exhibits an amorphous orpiment-like structure with As ions coordinated by 3 sulfur atoms (CN=3.0). The As-S interatomic distance of the first shell is calculated at 2.279Å and the Debye-Waller factor (σ2) is 0.00427. These data suggest that the modeled structure of the studied precipitates is slightly S-deficient and ordered only in the first shell around As, resembling an orpiment-type structure, whereas higher shells are not present and must be disordered. The disorder phenomenon may be strictly produced either by the existence of occasional As-S-As bridges with As-As bonds or by the occurrence of As-O-As bridges, causing twisting of the AsS3 pyramids in the initial orpiment structure. This distortion in the higher coordination shells of the structural sheets creates the amorphous orpiment. © 2015 Elsevier B.V..

Anesthetized mongrel (weight range: 16-27 Kg) dogs were prepared for monitoring hemodynamics, blood flow distribution, plasma colloid osmotic pressure and renal functional parameters at various intervals. Removal of 35 ml/Kg blood resulted in marked drop and only partial spontaneous recovery in systemic and pulmonary arterial pressures, cardiac output and organ blood flows (50% flow-decrements occurred in kidney, spleen, heart, gut and pancreas); plasma colloid osmotic pressure as well as urine output and creatinine clearance also fell. Group I (n = 6) of dogs was transfused after 45 minutes of hypovolemia with their own anticoagulated blood, while Group II (n = 6) received an equal volume of unmodified 6% stromafree hemoglobin solution (SFHS). Comparison of the two groups' responses to resuscitation yielded some differences. There was a significant overshoot (30 mmHg) in systemic arterial blood pressure accompanied by bradycardia in Group II only. Cardiac output recovered in both groups but was less well sustained in Group II. Cerebral blood flow rose higher and hepatic arterial flow-increment was less in Group II than in Group I; the responses to resuscitation in the other organs were comparable. Colloid osmotic pressure decreased in Group I whereas it rose immediately after resuscitation in Group II, declining thereafter with a converging trend and 30 minutes thereafter the differences were not significant between the groups. Urine excretion and creatinine clearance recovered to comparable extents in both groups, but N-acetyl-beta-D-glucosaminidase (N.A.G.) excretion rose over 10-fold higher in Group II than in Group I. These experiments have defined the response of bled animals to resuscitation with unmodified, unpurified SFHS, when compared to resuscitation with whole blood, showing a less well sustained but adequate hemodynamic and renal functional recovery while revealing indications of early renal tubular cellular injury, providing baseline comparison for testing highly purified and modified hemoglobin solutions.