48 research outputs found
Ammonia emission abatement does not fully control reduced forms of nitrogen deposition
Human activities and population growth have increased the natural burden of reactive nitrogen (N) in the environment. Excessive N deposition on Earth’s surface leads to adverse feedbacks on ecosystems and humans. Similar to that of air pollution, emission control is recognized as an efficient means to control acid deposition. Control of nitrogen oxides (NO_x = NO + NO₂) emissions has led to reduction in deposition of oxidized nitrogen (NO_y, the sum of all oxidized nitrogen species, except nitrous oxide [N₂O]). Reduced forms of nitrogen (NH_x = ammonia [NH₃] + ammonium [NH₄⁺]) deposition have, otherwise, increased, offsetting the benefit of reduction in NO_y deposition. Stringent control of NH₃ emissions is being considered. In this study, we assess the response of N deposition to N emission control on continental regions. We show that significant reduction of NHx deposition is unlikely to be achieved at the early stages of implementing NH₃ emission abatement. Per-unit NH₃ emission abatement is shown to result in only 60–80% reduction in NH_x deposition, which is significantly lower than the demonstrated 80–120% benefit of controlling NO_x emissions on NO_y deposition. This 60–80% effectiveness of NH_x deposition reduction per unit NH₃ emission abatement reflects, in part, the effects of simultaneous reductions in NO_x and SO₂ emissions
Stratospheric aerosol - Observations, processes, and impact on climate
Interest in stratospheric aerosol and its role in climate have increased over the last decade due to the observed increase in stratospheric aerosol since 2000 and the potential for changes in the sulfur cycle induced by climate change. This review provides an overview about the advances in stratospheric aerosol research since the last comprehensive assessment of stratospheric aerosol was published in 2006. A crucial development since 2006 is the substantial improvement in the agreement between in situ and space-based inferences of stratospheric aerosol properties during volcanically quiescent periods. Furthermore, new measurement systems and techniques, both in situ and space based, have been developed for measuring physical aerosol properties with greater accuracy and for characterizing aerosol composition. However, these changes induce challenges to constructing a long-term stratospheric aerosol climatology. Currently, changes in stratospheric aerosol levels less than 20% cannot be confidently quantified. The volcanic signals tend to mask any nonvolcanically driven change, making them difficult to understand. While the role of carbonyl sulfide as a substantial and relatively constant source of stratospheric sulfur has been confirmed by new observations and model simulations, large uncertainties remain with respect to the contribution from anthropogenic sulfur dioxide emissions. New evidence has been provided that stratospheric aerosol can also contain small amounts of nonsulfate matter such as black carbon and organics. Chemistry-climate models have substantially increased in quantity and sophistication. In many models the implementation of stratospheric aerosol processes is coupled to radiation and/or stratospheric chemistry modules to account for relevant feedback processes
Global Intraurban Intake Fractions for Primary Air Pollutants from Vehicles and Other Distributed Sources
We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100,000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14-52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6-3, and 0.1-0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations
Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice.
It is currently unknown how often and in which ways a genetic diagnosis given to a patient with epilepsy is associated with clinical management and outcomes.To evaluate how genetic diagnoses in patients with epilepsy are associated with clinical management and outcomes.This was a retrospective cross-sectional study of patients referred for multigene panel testing between March 18, 2016, and August 3, 2020, with outcomes reported between May and November 2020. The study setting included a commercial genetic testing laboratory and multicenter clinical practices. Patients with epilepsy, regardless of sociodemographic features, who received a pathogenic/likely pathogenic (P/LP) variant were included in the study. Case report forms were completed by all health care professionals.Genetic test results.Clinical management changes after a genetic diagnosis (ie, 1 P/LP variant in autosomal dominant and X-linked diseases; 2 P/LP variants in autosomal recessive diseases) and subsequent patient outcomes as reported by health care professionals on case report forms.Among 418 patients, median (IQR) age at the time of testing was 4 (1-10) years, with an age range of 0 to 52 years, and 53.8% (n = 225) were female individuals. The mean (SD) time from a genetic test order to case report form completion was 595 (368) days (range, 27-1673 days). A genetic diagnosis was associated with changes in clinical management for 208 patients (49.8%) and usually (81.7% of the time) within 3 months of receiving the result. The most common clinical management changes were the addition of a new medication (78 [21.7%]), the initiation of medication (51 [14.2%]), the referral of a patient to a specialist (48 [13.4%]), vigilance for subclinical or extraneurological disease features (46 [12.8%]), and the cessation of a medication (42 [11.7%]). Among 167 patients with follow-up clinical information available (mean [SD] time, 584 [365] days), 125 (74.9%) reported positive outcomes, 108 (64.7%) reported reduction or elimination of seizures, 37 (22.2%) had decreases in the severity of other clinical signs, and 11 (6.6%) had reduced medication adverse effects. A few patients reported worsening of outcomes, including a decline in their condition (20 [12.0%]), increased seizure frequency (6 [3.6%]), and adverse medication effects (3 [1.8%]). No clinical management changes were reported for 178 patients (42.6%).Results of this cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcomes.VoRSUNY DownstateNeurologyN/
Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice
IMPORTANCE: It is currently unknown how often and in which ways a genetic diagnosis given to a patient with epilepsy is associated with clinical management and outcomes.
OBJECTIVE: To evaluate how genetic diagnoses in patients with epilepsy are associated with clinical management and outcomes.
DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective cross-sectional study of patients referred for multigene panel testing between March 18, 2016, and August 3, 2020, with outcomes reported between May and November 2020. The study setting included a commercial genetic testing laboratory and multicenter clinical practices. Patients with epilepsy, regardless of sociodemographic features, who received a pathogenic/likely pathogenic (P/LP) variant were included in the study. Case report forms were completed by all health care professionals.
EXPOSURES: Genetic test results.
MAIN OUTCOMES AND MEASURES: Clinical management changes after a genetic diagnosis (ie, 1 P/LP variant in autosomal dominant and X-linked diseases; 2 P/LP variants in autosomal recessive diseases) and subsequent patient outcomes as reported by health care professionals on case report forms.
RESULTS: Among 418 patients, median (IQR) age at the time of testing was 4 (1-10) years, with an age range of 0 to 52 years, and 53.8% (n = 225) were female individuals. The mean (SD) time from a genetic test order to case report form completion was 595 (368) days (range, 27-1673 days). A genetic diagnosis was associated with changes in clinical management for 208 patients (49.8%) and usually (81.7% of the time) within 3 months of receiving the result. The most common clinical management changes were the addition of a new medication (78 [21.7%]), the initiation of medication (51 [14.2%]), the referral of a patient to a specialist (48 [13.4%]), vigilance for subclinical or extraneurological disease features (46 [12.8%]), and the cessation of a medication (42 [11.7%]). Among 167 patients with follow-up clinical information available (mean [SD] time, 584 [365] days), 125 (74.9%) reported positive outcomes, 108 (64.7%) reported reduction or elimination of seizures, 37 (22.2%) had decreases in the severity of other clinical signs, and 11 (6.6%) had reduced medication adverse effects. A few patients reported worsening of outcomes, including a decline in their condition (20 [12.0%]), increased seizure frequency (6 [3.6%]), and adverse medication effects (3 [1.8%]). No clinical management changes were reported for 178 patients (42.6%).
CONCLUSIONS AND RELEVANCE: Results of this cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcomes
Ammonia emission abatement does not fully control reduced forms of nitrogen deposition
Significance
Control of nitrogen oxides emissions has successfully reduced the deposition of oxidized nitrogen over the United States. Recent studies have called attention to the rapid growth of deposition of reduced forms of nitrogen, which would offset the benefits of reduction in oxidized nitrogen deposition. Our analysis, based on both monitoring and modeling approaches, illustrates that implementing ammonia emission abatement may not lead to full response in nitrogen deposition over continental regions. Here we provide important information to the community and policy makers concerning nitrogen deposition, given the urgent needs for developing control strategies on ammonia emissions.</jats:p
Neuroangiography: Review of Anatomy, Periprocedural Management, Technique, and Tips
AbstractNeuroangiography (NA) is a minimally invasive procedure used to diagnose patients with neurovascular diseases. Noninvasive imaging has improved dramatically in recent years and is utilized more frequently; however, further evaluation with NA is still required in certain cases. NA indications include intracranial (cerebral aneurysms, arteriovenous malformations, dural arteriovenous fistula, cerebral vasculitis, cerebral vasospasm, ischemic stroke, nontraumatic subarachnoid hemorrhage, intracerebral hemorrhage, Moyamoya, vein of Galen malformation, intracranial tumors, and pseudotumor cerebri) and extracranial (internal and common carotid artery stenosis, vertebral artery stenosis, carotid artery blowout, vertebral artery blowout, epistaxis, oropharyngeal bleeding, and carotid body tumor) pathologies which can help with diagnosis and potential subsequent endovascular treatment. A thorough understanding of normal and variant cervical/cranial vascular anatomy is required. In addition, periprocedural management, catheter technique, equipment needed, and underlying disease pathology are paramount to successful and safe outcomes. This article will review basic neurovascular anatomy, periprocedural management, NA technique, and tips for safe and successful outcomes.</jats:p
Traumatic unilateral lumbosacral jumped facet without fracture in a child – presentation of a safe treatment strategy for a rare injury
The vast majority of pediatric lumbosacral spondylolisthesis have developmental etiology. Of the very rare type of pediatric lumbosacral facet dislocations, there are only three reported cases of a pediatric unilateral jumped facet injury. All of these cases are associated with fracture dislocation of L5-S1. Hyperflexion with rotation is thought to provoke this uncommon type of spine injury. The authors report the first pediatric patient reported in literature to date with a traumatic unilateral jumped facet at the lumbosacral joint without fracture. The presentation, surgical treatment, hospital course, outcome and management options with the review of the literature is summarized
Idiopathic Intracranial Hypertension: Contemporary Management and Endovascular Techniques
AbstractIdiopathic intracranial hypertension (IIH) is a disease process of abnormally increased intracranial pressure in the absence of a mass lesion. Medical management, optic nerve fenestration, and surgical shunting procedures have failed to produce consistently successful results. In an unknown percentage of cases, IIH is caused by dural venous sinus obstruction which can be cured by endovascular treatment with dural venous sinus stent placement. This helps prevent progressive vision loss and worsening papilledema caused by underlying increased intracranial pressure from venous outflow obstruction. Patients are required to have an established diagnosis of IIH, preferably made by a neuroophthalmologist, with clearly documented papilledema or at minimum visual disturbance along with lumbar puncture opening pressure greater than 25 cm H2O. Transverse to sigmoid sinus focal narrowing (intraluminal filling defect or extrinsic compression) must be seen during the venous phase of neuroangiography (NA) along with a pressure gradient of 10 mm Hg or greater across the focal narrowing during dural venous sinus pressure monitoring. A successful reduction is defined as a pressure gradient of less than 10 mm Hg after stent placement. Neuroophthalmologic follow-up occurs within 1 to 2 months to assess for changes in papilledema. If papilledema is unchanged or worsened, NA and hemodynamic evaluation is repeated for consideration of restenting. Appropriate patient selection criteria are required for IIH venous sinus stenting. The utilization of refined endovascular techniques along with postprocedure follow-up protocols can ultimately cure IIH for a select group of patients.</jats:p
Effect of topographical and soil complexity on potato yields in irrigated fields
Spatial variation of soil moisture as affected by topography and soil textural patterns is an important control on variability of yields in agricultural fields. Site-specific irrigation management could be a way of increasing water use efficiency and evening out yield variability. A better understanding of regional landscapes is required to identify which types of fields could benefit from SSIM. The causal influence of landscape characteristics on yields under irrigated conditions is poorly understood. Here, a new approach is used to infer the causal impact of topography and soil properties on yields of irrigated potatoes. The analysis comprises a four-year long dataset of potato yield, soil texture, hydrological, topographical, and meteorological variables collected from 99 sites within 19 fields in southern Alberta, Canada, from 2019 to 2022 inclusive. Using a Bayesian linear mixed model, we quantified the effect of topographical complexity (median equal −3.39 MT ha−1), soil texture complexity (median equal −1.97 MT ha−1), and the cases where both were true (median equal −4.47 MT ha−1), on potato yields. Using the same method, we quantified the effect on initial soil water storage with medians equal to −13.1 mm (topographical complexity), 1.7 mm (soil complexity), and −6.7 mm (both). The topographical and soil complexity metrics applied could be used to identify fields that are suitable for SSIM-VRI. Findings are likely specific to the geographical and weather conditions encountered in the study area. We encourage implementation of our method in different regions to determine the generality of our results
