ABSTRACT
An increasing percentage of US waste methane (CH4) emissions come from wastewater treatment (10% in 1990 to 14% in 2019), although there are limited measurements across the sector, leading to large uncertainties in current inventories. We conducted the largest study of CH4 emissions from US wastewater treatment, measuring 63 plants with average daily flows ranging from 4.2 × 10-4 to 8.5 m3 s-1 (<0.1 to 193 MGD), totaling 2% of the 62.5 billion gallons treated, nationally. We employed Bayesian inference to quantify facility-integrated emission rates with a mobile laboratory approach (1165 cross-plume transects). The median plant-averaged emission rate was 1.1 g CH4 s-1 (0.1-21.6 g CH4 s-1; 10th/90th percentiles; mean 7.9 g CH4 s-1), and the median emission factor was 3.4 × 10-2 g CH4 (g influent 5 day biochemical oxygen demand; BOD5)-1 [0.6-9.9 × 10-2 g CH4 (g BOD5)-1; 10th/90th percentiles; mean 5.7 × 10-2 g CH4 (g BOD5)-1]. Using a Monte Carlo-based scaling of measured emission factors, emissions from US centrally treated domestic wastewater are 1.9 (95% CI: 1.5-2.4) times greater than the current US EPA inventory (bias of 5.4 MMT CO2-eq). With increasing urbanization and centralized treatment, efforts to identify and mitigate CH4 emissions are needed.
Subject(s)
Methane , Water Purification , United States , Bayes Theorem , Wastewater , Nitrous Oxide/analysisABSTRACT
Municipal wastewater collection and treatment systems are critical infrastructures, and they are also identified as major sources of anthropogenic CH4 emissions that contribute to climate change. The actual CH4 emissions at the plant- or regional level vary greatly due to site-specific conditions as well as high seasonal and diurnal variations. Here, we conducted the first quantitative analysis of CH4 emissions from different types of sewers and water resource recovery facilities (WRRFs). We examined variations in CH4 emissions associated with methods applied in different monitoring campaigns, and identified main CH4 sources and sinks to facilitate carbon emission reduction efforts in the wastewater sector. We found plant-wide CH4 emissions vary by orders of magnitude, from 0.01 to 110 g CH4/m3 with high emissions associated with plants equipped with anaerobic digestion or stabilization ponds. Rising mains show higher dissolved CH4 concentrations than gravity sewers when transporting similar raw sewage under similar environmental conditions, but the latter dominates most collection systems around the world. Using the updated data sets, we estimated annual CH4 emission from the U.S. centralized, municipal wastewater treatment to be approximately 10.9 ± 7.0 MMT CO2-eq/year, which is about twice as the IPCC (2019) Tier 2 estimates (4.3-6.1 MMT CO2-eq/year). Given CH4 emission control will play a crucial role in achieving net zero carbon goals by the midcentury, more studies are needed to profile and mitigate CH4 emissions from the wastewater sector.
Subject(s)
Carbon Dioxide , Wastewater , Carbon Dioxide/analysis , Methane/analysis , Sewage , CarbonABSTRACT
Background. A Required Fourth-Year Medical Student Physical Medicine and Rehabilitation (PM&R) Clerkship was found to increase students' knowledge of PM&R; however the students' overall rotation evaluations were consistently lower than the other 8 required clerkships at the medical school. Objective. To describe the impact of a revised curriculum based upon Entrustable Professional Activities and focusing on basic pain management, musculoskeletal care, and neurology. Setting. Academic Medical Center. Participants. 73 fourth-year medical students. Methods. The curriculum changes included a shift in the required readings from rehabilitation specific topics toward more general content in the areas of clinical neurology and musculoskeletal care. Hands-on workshops on neurological and musculoskeletal physical examination techniques, small group case-based learning, an anatomy clinical correlation lecture, and a lecture on pain management were integrated into the curriculum. Main Outcome Measurements. Student evaluations of the clerkship. Results. Statistically significant improvements were found in the students' evaluations of usefulness of lecturers, development of patient interviewing skills, and diagnostic and patient management skills (p ≤ 0.05). Conclusions. This study suggests that students have a greater satisfaction with a required PM&R clerkship when lecturers utilize a variety of pedagogic methods to teach basic pain, neurology and musculoskeletal care skills in the rehabilitation setting rather than rehabilitation specific content.
ABSTRACT
This article describes the difficulty of diagnosing traumatic brain injury (TBI), treatment protocols provided through the military, an alternative therapy with scientific evidence of its effectiveness in repairing injured brain tissue, challenges faced by brain-injured veterans seeking community reintegration, and state services that are available to help veterans.
Subject(s)
Brain Injuries/diagnosis , Brain Injuries/therapy , Stress Disorders, Post-Traumatic/diagnosis , Stress Disorders, Post-Traumatic/therapy , Veterans , Brain Injuries/psychology , Clinical Protocols , Humans , North Carolina , Stress Disorders, Post-Traumatic/etiologyABSTRACT
An exploratory study was conducted to determine the feasibility and clinical utility of remote electromyography (EMG) and nerve conduction studies over Internet Protocol (IP) networks. A progression of technical approaches was attempted until a workable solution was discovered. An evaluation form was completed for each tele-EMG session to attempt to quantify the clinical utility of tele-EMG. In all, 73 tele-EMG examinations were conducted over 29 months. Improvements in scores of evaluation survey items corresponded with the technical modifications. The final working model involved the use of contemporaneous developments in commercial videoconferencing systems that allowed simultaneous transmission and remote display of video and EMG computer (video graphics array [VGA]) signals. This exploratory study demonstrated a technical solution that met the clinical needs of rehabilitation medicine physicians for remote assessment of EMG and nerve conduction studies.
Subject(s)
Electromyography , Internet , Telemedicine/methods , Academic Medical Centers , Humans , North CarolinaABSTRACT
Reports of non-neural differentiation of neural stem cells (NSCs) have been challenged by alternative explanations for expanded differentiation potentials. In an attempt to demonstrate the plasticity of NSC, neurospheres were generated from single retrovirally labeled embryonic cortical precursors. In a defined serum-free insulin-containing media, 40% of the neurospheres contained both myogenic and neurogenic differentiated progeny. The number of NSCs displaying multilineage differentiation potential declines through gestation but does exist in the adult animal. In this system, insulin appears to function as a survival and dose-dependent myogenic differentiation signal for multilineage NSCs (MLNSC). MLNSC-derived cardiomyocytes contract synchronously, respond to sympathetic and parasympathetic stimulation, and regenerate injured heart tissues. These studies provide support for the hypothesis that MLNSCs exist throughout the lifetime of the animal, and potentially provide a population of stem cells for cell-based regenerative medicine strategies inside and outside of the nervous system.
Subject(s)
Insulin/physiology , Neurons/metabolism , Stem Cells/cytology , Animals , Blotting, Southern , Blotting, Western , Cell Differentiation , Cell Line , Cell Lineage , Cell Survival , Cloning, Molecular , Coloring Agents/pharmacology , Culture Media, Serum-Free/pharmacology , DNA/metabolism , Dose-Response Relationship, Drug , Flow Cytometry , Immunohistochemistry , Insulin/metabolism , Mice , Myocytes, Cardiac/metabolism , Neurons/cytology , Retroviridae/genetics , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , TransfectionABSTRACT
OBJECTIVE: To investigate the research activity and perspectives, and the predictors and barriers to research activity, in a cohort of individuals completing a research enrichment program for physiatrists. DESIGN: A retrospective cohort study design was utilized. Data collection was accomplished with a mailed survey, which was sent to 68 individuals who had completed the Research Enrichment Program for Physiatrists between 1991 and 1998. Data analysis was performed using both descriptive and inferential statistical methods. RESULTS: Eighty-five percent (58 of 68) of surveys were completed and returned. The majority of respondents were in academic-based practice (83%) at the assistant professor level (59%). Sixty-nine percent of the group reported spending no time in research, and 64% reported having no "protected" time for research. The mean number of peer-reviewed journal publications was 2.4, and the average number of research grants was 1.6, with 57% of the cohort reporting no grant funding. Departmental PhD, statistical, and secretarial support for research were all noted to be inadequate or not available for >50% of the cohort. High demand for clinical productivity, lack of protected research time, and lack of research funding were all identified as major barriers to research activity. Cluster analysis found greater research time and support to be associated with measures of research productivity. CONCLUSION: Long-term research success seems to require ongoing support, funding, and mentorship at the departmental and institutional level. Despite adequate training and motivation for research, research support was perceived as inadequate for many Research Enrichment Program graduates.