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We report national scale estimates of CO2 emissions from fossil-fuel combustion and cement production in the United States based directly on atmospheric observations, using a dual-tracer inverse modeling framework and CO2 and [Formula: see text] measurements obtained primarily from the North American portion of the National Oceanic and Atmospheric Administration's Global Greenhouse Gas Reference Network. The derived US national total for 2010 is 1,653 ± 30 TgC yr-1 with an uncertainty ([Formula: see text]) that takes into account random errors associated with atmospheric transport, atmospheric measurements, and specified prior CO2 and 14C fluxes. The atmosphere-derived estimate is significantly larger ([Formula: see text]) than US national emissions for 2010 from three global inventories widely used for CO2 accounting, even after adjustments for emissions that might be sensed by the atmospheric network, but which are not included in inventory totals. It is also larger ([Formula: see text]) than a similarly adjusted total from the US Environmental Protection Agency (EPA), but overlaps EPA's reported upper 95% confidence limit. In contrast, the atmosphere-derived estimate is within [Formula: see text] of the adjusted 2010 annual total and nine of 12 adjusted monthly totals aggregated from the latest version of the high-resolution, US-specific "Vulcan" emission data product. Derived emissions appear to be robust to a range of assumed prior emissions and other parameters of the inversion framework. While we cannot rule out a possible bias from assumed prior Net Ecosystem Exchange over North America, we show that this can be overcome with additional [Formula: see text] measurements. These results indicate the strong potential for quantification of US emissions and their multiyear trends from atmospheric observations.

We identified a PSEN1 (presenilin 1) mutation carrier from the world's largest autosomal dominant Alzheimer's disease kindred, who did not develop mild cognitive impairment until her seventies, three decades after the expected age of clinical onset. The individual had two copies of the APOE3 Christchurch (R136S) mutation, unusually high brain amyloid levels and limited tau and neurodegenerative measurements. Our findings have implications for the role of APOE in the pathogenesis, treatment and prevention of Alzheimer's disease.

Long-term atmospheric CO2 mole fraction and δ13CO2 observations over North America document persistent responses to the El Niño-Southern Oscillation. We estimate these responses corresponded to 0.61 (0.45 to 0.79) PgC year-1 more North American carbon uptake during El Niño than during La Niña between 2007 and 2015, partially offsetting increases of net tropical biosphere-to-atmosphere carbon flux around El Niño. Anomalies in derived North American net ecosystem exchange (NEE) display strong but opposite correlations with surface air temperature between seasons, while their correlation with water availability was more constant throughout the year, such that water availability is the dominant control on annual NEE variability over North America. These results suggest that increased water availability and favorable temperature conditions (warmer spring and cooler summer) caused enhanced carbon uptake over North America near and during El Niño.

Background and Objective: To investigate visual outcomes for macula-off rhegmatogenous retinal detachments (RRD) compared to macula-on RRDs based on duration from diagnosis to surgical repair performed by a single surgeon with access to a retina call block system. Patients and Methods: A case-control study reviewing the visual acuity (VA) after surgical repair in consecutive macula-off (n = 127) and maculaon (n = 63) RRD comparison eyes that underwent primary RRD repair performed by a single surgeon with dedicated retina call block time. Results: Our results revealed significantly improved VA in macula-off RRD eyes repaired within 3 days of diagnosis at 3, 6, and 12 months/last follow-up, and that duration from diagnosis to surgery is a predictor of VA at 3- and 12-month/last follow-up postoperative visits. Conclusion: Our findings support the use of mechanisms that improve access to operating room time, such as a retina call block system, to expedite surgical repair access. [Ophthalmic Surg Lasers Imaging Retina 2025;56:30–36.] [ABSTRACT FROM AUTHOR]

This report aims to describe the clinical presentation of a patient with an atypical central retinal vein occlusion (CRVO) in the setting of multiple myeloma. The patient was a 72-year-old man with an extensive hematologic-oncologic history and cardiovascular risk factors who presented with new-onset blurry vision and visual acuity (VA) of 20/40 in the left eye. The VA worsened to 20/60 two months after the initial presentation. By the 6-month follow-up visit, a series of three intravitreal bevacizumab injections for macular edema improved VA from 20/60 to 20/40. This case demonstrates the importance of fluorescein angiography in diagnosing a CRVO and exemplifies an atypical presentation on exam and imaging studies. [Ophthalmic Surg Lasers Imaging Retina 2024;55:730–733.] [ABSTRACT FROM AUTHOR]

Purpose: To investigate structure-function associations between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics across stages of non-proliferative (NPDR) and proliferative diabetic retinopathy (PDR), without diabetic macular oedema. Methods: Prospective cross-sectional study in 140 eyes of 99 patients: 33 mild NPDR, 24 moderate/severe NPDR, 15 PDR, 33 diabetic without DR (DMnoDR) and 46 control eyes. Mixed-effects multivariable regression models to evaluate associations between quantitative contrast sensitivity function (Adaptive Sensory Technology) and vessel density (VD) and vessel skeletonised density (VSD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) on same-day imaging with WF SS-OCTA (Plex Elite 9000, Carl Zeiss Meditec). Results: Standardised β coefficients for area under the logarithm of contrast sensitivity function curve (AULCSF) versus visual acuity (VA) at 3×3 mm scans: SCP VSD (β=0.32, p<0.001 vs -0.18, p=0.044), DCP VSD (β=0.30, p<0.001 vs -0.21, p=0.02), SCP VD (β=0.25, p=0.004 vs -0.13, p=0.129), DCP VD (β=0.26, p=0.003 vs -0.19, p=0.034). AULCSF was significantly reduced in mild NPDR (β=-0.28, p<0.001) and DMnoDR (β=-0.19, p=0.005) versus controls, while VA was not significantly different. AULCSF performed better than VA in differentiating between controls and DMnoDR (0.69 vs 0.50), controls and mild NPDR (0.76 vs 0.61) and controls and moderate/severe NPDR (0.89 vs 0.73). Conclusions: DR-induced microvascular changes on OCTA are associated with larger changes on CS than in VA. CS is affected earlier than VA in the course of DR and performed better in discriminating between controls, DMnoDR and across DR stages. [ABSTRACT FROM AUTHOR]

Vitreous hemorrhage involves blood leakage into or around the vitreous cavity, which presents complex management decisions. Treatment options for nondiabetic vitreous hemorrhage (NDVH) traditionally include observation or early vitrectomy. Traditional guidelines have long emphasized an initial period of cautious observation. This systematic review shows that a significant portion (∼62% to 75%) of NDVH patients present a retinal tear and/or detachment upon initial presentation. B-scan ultrasonography, the primary diagnostic tool, exhibits variable sensitivities and may miss approximately half (46.4%) of underlying tears or detachments. Only 25% of observed NDVH cases clear spontaneously, while the remaining will ultimately require vitrectomy due to nonclearance (45%) or sight-threatening complications (30%). Patients under observation experience visual deficits as hemorrhage clears slowly, challenging the efficacy of traditional guidelines favoring observation. While there is no clear guideline concerning the management of NDVH, our findings suggest that early vitrectomy for severe NDVH may be the safest and most appropriate approach, provided the patient accepts procedural risks like cataract development. [Ophthalmic Surg Lasers Imaging Retina 2024;55:660–667.] [ABSTRACT FROM AUTHOR]

Background and Objective: Three-dimensional heads-up display (HUD) systems have emerged as an alternative to standard operating microscope (SOM) in the operating room. The goal of this study was to quantitatively measure vitreoretinal surgeon posture across visualization methods. Methods: Ergonomic data was collected from 64 cases at two tertiary eye care centers. Surgeons wore an Upright Go 2TM posture training device while operating either using the NGENUITY 3D heads-up display visualization system or the SOM. Results: Total percentage of time with upright posture as primary surgeon was significantly higher in surgeries performed using HUD (median 100%, interquartile range [IQR], 85.1% to 100.0%) as compared to surgeries performed using the SOM (median 60.0%, IQR 1.8% to 98.8%) (P = 0.001, Wilcoxon rank-sum test). Percent time with upright posture was significantly higher in surgeries performed using HUD for two of the three surgeons when assessed independently across systems. Results remained significant when accounting for length of surgery (P < 0.001, multiple linear regression). Conclusions: Ergonomic positioning was improved for surgeons operating using HUD. Given the high prevalence of back and neck pain among vitreoretinal surgeons, increased use of HUD systems may limit musculoskeletal pain and long-term disability from poor ergonomics. [Ophthalmic Surg Lasers Imaging Retina 2024;55:638–645.] [ABSTRACT FROM AUTHOR]

In response to warming climate, methane can be released to Arctic Ocean sediment and waters from thawing subsea permafrost and decomposing methane hydrates. However, it is unknown whether methane derived from this sediment storehouse of frozen ancient carbon reaches the atmosphere. We quantified the fraction of methane derived from ancient sources in shelf waters of the U.S. Beaufort Sea, a region that has both permafrost and methane hydrates and is experiencing significant warming. Although the radiocarbon-methane analyses indicate that ancient carbon is being mobilized and emitted as methane into shelf bottom waters, surprisingly, we find that methane in surface waters is principally derived from modern-aged carbon. We report that at and beyond approximately the 30-m isobath, ancient sources that dominate in deep waters contribute, at most, 10 ± 3% of the surface water methane. These results suggest that even if there is a heightened liberation of ancient carbon-sourced methane as climate change proceeds, oceanic oxidation and dispersion processes can strongly limit its emission to the atmosphere.

Ozone depleting substances (ODSs) controlled by the Montreal Protocol are potent greenhouse gases (GHGs), as are their substitutes, the hydrofluorocarbons (HFCs). Here we provide for the first time a comprehensive estimate of U.S. emissions of ODSs and HFCs based on precise measurements in discrete air samples from across North America and in the remote atmosphere. Derived emissions show spatial and seasonal variations qualitatively consistent with known uses and largely confirm U.S. Environmental Protection Agency (EPA) national emissions inventories for most gases. The measurement-based results further indicate a substantial decline of ODS emissions from 2008 to 2014, equivalent to ~50% of the CO2-equivalent decline in combined emissions of CO2 and all other long-lived GHGs inventoried by the EPA for the same period. Total estimated CO2-equivalent emissions of HFCs were comparable to the sum of ODS emissions in 2014, but can be expected to decline in the future in response to recent policy measures.

High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO2) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO2 with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO2 fluxes across Alaska during 2012-2014. We find that tundra ecosystems were a net source of CO2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO2 emission rates from North Slope tundra have increased during the October through December period by 73% ± 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO2 in Alaska, in response to climate warming. Our results provide evidence that the decadal-scale increase in the amplitude of the CO2 seasonal cycle may be linked with increasing biogenic emissions in the Arctic, following the growing season. Early winter respiration was not well simulated by the Earth System Models used to forecast future carbon fluxes in recent climate assessments. Therefore, these assessments may underestimate the carbon release from Arctic soils in response to a warming climate.