Total Social Costs and Benefits of Long-Distance Hydropower Transmission.

Increasing amounts of hydropower are being exported from Canada to the northern United States. Recently proposed projects would increase transmission capacity to U.S. population centers without increasing generation. This avoids generation-side impacts from hydroelectric development and introduces power to the U.S. energy mix that is dispatchable, unlike wind and solar, with greenhouse gas emissions generally lower than those of fossil fuels. There is, however, a lack of analysis comparing high upfront capital costs to social benefits and controversy over valuation of social costs of hydropower from existing generation given the negligible marginal cost of production. This analysis evaluates direct and indirect costs in comparison to alternatives for a 1250 MW transmission line from Canada to New York City currently under development to replace the recent loss of ∼15 TWh year-1 of nuclear generation. For the case study considered, we find that long-distance transmission avoids $13.2 billion ($12.1-14.4 billion) in total social costs by 2050. This includes $4.2 billion ($3.4-5.1 billion) from premature mortality in disproportionately Hispanic and African American or Black counties (roughly 306 avoided deaths). In an extensive sensitivity analysis, results are robust to all modeling choices other than the cost assigned to hydropower: the nominal dollar value of hydropower imports (payments from buyer to seller) commonly used in cost-benefit analysis leads to substantial underestimates of net benefits from transmission projects. The opportunity cost of these imports (e.g., environmental benefits foregone in alternative export markets) is a better metric for cost but is difficult to estimate.

Repair of a delayed, traumatic dorsal diaphragmatic hernia using a single paracostal approach in a dog.

CASE HISTORY: A 1-year-old German Shepherd dog presented for delayed onset of a traumatic, dorsal diaphragmatic hernia of the pars lumborum. CLINICAL FINDINGS AND TREATMENT: Herniorrhaphy via a ventral midline celiotomy (with and without a paracostal extension) were unsuccessful and the hernia recurred. The hernia was successfully repaired using a single lateral paracostal surgical approach. This approach provided excellent exposure and should be considered for dorsal pars lumborum diaphragmatic hernia repairs. DIAGNOSIS: Dorsal diaphragmatic hernia of the pars lumborum. CLINICAL RELEVANCE: Whilst uncommon, tears to the dorsal aspect of the diaphragm should be considered as well as the more common radial or circumferential pars costalis tears. Pre-operative computed tomographic imaging can identify the exact location of the hernia in order to allow the best surgical approach to be determined. A lateral paracostal approach should be considered as an alternative to a ventral midline celiotomy with or without paracostal extension for repair of dorsal diaphragmatic hernias affecting the pars lumborum, as it provides excellent exposure. A single lateral paracostal approach has not been reported previously for diaphragmatic hernia repair in dogs.

Motor Protein Transport Along Inhomogeneous Microtubules.

Many cellular processes rely on the cell's ability to transport material to and from the nucleus. Networks consisting of many microtubules and actin filaments are key to this transport. Recently, the inhibition of intracellular transport has been implicated in neurodegenerative diseases such as Alzheimer's disease and Amyotrophic Lateral Sclerosis. Furthermore, microtubules may contain so-called defective regions where motor protein velocity is reduced due to accumulation of other motors and microtubule-associated proteins. In this work, we propose a new mathematical model describing the motion of motor proteins on microtubules which incorporate a defective region. We take a mean-field approach derived from a first principle lattice model to study motor protein dynamics and density profiles. In particular, given a set of model parameters we obtain a closed-form expression for the equilibrium density profile along a given microtubule. We then verify the analytic results using mathematical analysis on the discrete model and Monte Carlo simulations. This work will contribute to the fundamental understanding of inhomogeneous microtubules providing insight into microscopic interactions that may result in the onset of neurodegenerative diseases. Our results for inhomogeneous microtubules are consistent with prior work studying the homogeneous case.

Risk tradeoffs associated with traditional food advisories for Labrador Inuit.

The traditional Inuit diet includes wild birds, fish and marine mammals, which can contain high concentrations of the neurotoxicant methylmercury (MeHg). Hydroelectric development may increase MeHg concentrations in traditional foods. Consumption advisories are often used to mitigate such risks and can result in reduced intake of traditional foods. Data from a dietary survey, MeHg exposure assessment and risk analysis for individuals in three Inuit communities in Labrador, Canada (n = 1145) in 2014 indicate reducing traditional food intake is likely to exacerbate deficiencies in n-3 polyunsaturated fatty acids and vitamins B12 and B2. Traditional foods accounted for < 5% of per-capita calories but up to 70% of nutrients consumed. Although consumption advisories could lower neurodevelopmental risks associated with an increase in MeHg exposure (90th-percentile ∆IQ = - 0.12 vs. - 0.34), they may lead to greater risks of cardiovascular mortality (90th-percentile increase: + 58% to + 116% vs. + 25%) and cancer mortality (90th-percentile increase + 2% to + 4% vs. no increase). Conversely, greater consumption of locally caught salmon mostly unaffected by hydroelectric flooding would lower all these risks (90th-percentile ∆IQ = + 0.4; cardiovascular risk: - 45%; cancer risk: - 1.4%). We thus conclude that continued consumption of traditional foods is essential for Inuit health in these communities.

Freshwater discharges drive high levels of methylmercury in Arctic marine biota.

Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25-200%, overwhelming climate-driven changes over the next decade.

Future Impacts of Hydroelectric Power Development on Methylmercury Exposures of Canadian Indigenous Communities.

Developing Canadian hydroelectric resources is a key component of North American plans for meeting future energy demands. Microbial production of the bioaccumulative neurotoxin methylmercury (MeHg) is stimulated in newly flooded soils by degradation of labile organic carbon and associated changes in geochemical conditions. We find all 22 Canadian hydroelectric facilities being considered for near-term development are located within 100 km of indigenous communities. For a facility in Labrador, Canada (Muskrat Falls) with planned completion in 2017, we probabilistically modeled peak MeHg enrichment relative to measured baseline conditions in the river to be impounded, downstream estuary, locally harvested fish, birds and seals, and three Inuit communities. Results show a projected 10-fold increase in riverine MeHg levels and a 2.6-fold increase in estuarine surface waters. MeHg concentrations in locally caught species increase 1.3 to 10-fold depending on time spent foraging in different environments. Mean Inuit MeHg exposure is forecasted to double following flooding and over half of the women of childbearing age and young children in the most northern community are projected to exceed the U.S. EPA's reference dose. Equal or greater aqueous MeHg concentrations relative to Muskrat Falls are forecasted for 11 sites across Canada, suggesting the need for mitigation measures prior to flooding.

Geohealth Policy Benefits Are Mediated by Interacting Natural, Engineered, and Social Processes.

Interest in health implications of Earth science research has significantly increased. Articles frequently dispense policy advice, for example, to reduce human contaminant exposures. Recommendations such as fish consumption advisories rarely reflect causal reasoning around tradeoffs or anticipate how scientific information will be received and processed by the media or vulnerable communities. Health is the product of interacting social and physical processes, yet predictable responses are often overlooked. Analysis of physical and social mechanisms, and health and non-health tradeoffs, is needed to achieve policy benefits rather than "policy impact." Dedicated funding mechanisms would improve the quality and availability of these analyses.

COVID-19 Reveals Vulnerabilities of the Food-Energy-Water Nexus to Viral Pandemics.

Food, energy, and water (FEW) sectors are inextricably linked, making one sector vulnerable to disruptions in another. Interactions between FEW systems, viral pandemics, and human health have not been widely studied. We mined scientific and news/media articles for causal relations among FEW and COVID-19 variables and qualitatively characterized system dynamics. Food systems promoted the emergence and spread of COVID-19, leading to illness and death. Major supply-side breakdowns were avoided (likely due to low morbidity/mortality among working-age people). However, COVID-19 and physical distancing disrupted labor and capital inputs and stressed supply chains, while creating economic insecurity among the already vulnerable poor. This led to demand-side FEW insecurities, in turn increasing susceptibility to COVID-19 among people with many comorbidities. COVID-19 revealed trade-offs such as allocation of water to hygiene versus to food production and disease burden avoided by physical distancing versus disease burden from increased FEW insecurities. News/media articles suggest great public interest in FEW insecurities triggered by COVID-19 interventions among individuals with low COVID-19 case-fatality rates. There is virtually no quantitative analysis of any of these trade-offs or feedbacks. Enhanced quantitative FEW and health models are urgently needed as future pandemics are likely and may have greater morbidity and mortality than COVID-19.

Role of detection limits in drinking water regulation.

Some commentators on environmental science and policy have claimed that advances in analytical chemistry, reflected by an ability to detect contaminants at ever-decreasing concentrations, lead to regulations stricter than justified by available toxicological data. We evaluate this claim in the context of drinking water regulation, with respect to contaminants regulated under the Safe Drinking Water Act (SDWA). We examine the relationships between historical and present maximum contaminant levels and goals in the greater context of detection capability and evaluate the extent to which different aspects of the regulatory apparatus (i.e., analytical capability, cost-benefit analysis, analysis of competing risks, and available toxicological data) influence the regulatory process. Our findings do not support the claim that decreases in detection limit lead to more stringent regulation in the context of drinking water regulation in the United States. Further, based on our analysis of the National Primary Drinking Water Regulation and existing United States Environmental Protection Agency approaches to establishing the practical quantifiable level, we conclude that in the absence of changes to the underlying toxicological model, regulatory revision is unlikely.

Fibroblastic Subtype has a Favourable Prognosis in Appendicular Osteosarcoma of Dogs.

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546 ± 105 days) in comparison with dogs having appendicular osteoblastic (257 ± 48 days) or appendicular chondroblastic (170 ± 28 days) OS (P = 0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P = 0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.

Immunohistochemical Validation of Spontaneously Arising Canine Osteosarcoma as a Model for Human Osteosarcoma.

Osteosarcoma (OS) originates from bone-forming mesenchymal cells and represents one of the primary bone tumours. It is the most common primary bone tumour in dogs and man. The characterization of an appropriate natural disease animal model to study human OS is essential to elucidate the pathogenesis of the disease. This study aimed to validate canine OS as a model for the human disease by evaluating immunohistochemically the expression of markers known to be important in human OS. The immunohistochemical panel included vimentin, alkaline phosphatase (ALP), desmin, S100, neuron-specific enolase (NSE), runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 4 (BMP4). Immunohistochemistry was conducted on formalin-fixed, paraffin wax-embedded tissue sections from 59 dogs with confirmed primary OS. Vimentin, ALP, Runx2 and BMP4 were highly expressed by all tumours, while desmin, S100 and NSE were expressed variably. The findings were similar to those described previously for human OS and suggest that canine OS may represent a useful model for the study of the human disease.

Rayleigh approximation to ground state of the Bose and Coulomb glasses.

Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.

The impact of kyphosis on daily functioning.

OBJECTIVES: To determine whether moderate or severe kyphosis is associated with decrements in physical function, especially mobility. DESIGN: Cross-sectional analysis of a cohort study. SETTING: The Johns Hopkins Functional Status Laboratory, a multidisciplinary, standardized, quantitative assessment center. PARTICIPANTS: A total of 231 community-dwelling volunteers aged 59 and older who participated in a 1-day evaluation. MEASUREMENTS: Age, gender, self report of physical function, standardized measurement of: kyphosis (both qualitatively clinical criteria and quantitative assessment), time to walk 5 meters (0.1 seconds), and time to climb a flight of stairs (0.1 seconds) at usual pace. RESULTS: Using multivariate step-wise regression analysis, the presence and severity of kyphosis, measured qualitatively, was independently associated with time to walk 5 meters and to climb a flight of stairs (P = .015, P < .001, respectively), adjusting for moderate-severe scoliosis, heart rate response to exercise, arthritis, vertigo, age, and gender. Similarly, quantitative kyphosis was associated independently with stair climb time (P = .005). Qualitative kyphosis was also associated with difficulty reaching (OR = 2.21 (95% CI: 1.14 to 4.29)) and difficulty performing heavy housework (OR = 1.64 (95% CI: 1.03 to 2.61)), adjusting for prior diagnosis of moderate-severe scoliosis, prior diagnosis of arthritis, age, and gender. CONCLUSION: Kyphosis, by both clinical and quantitative assessment, is associated with diminished function, especially performance of mobility tasks. This association should be verified prospectively. If predictive, the impact of kyphosis on physical function should be considered in osteoporosis prevention and treatment counseling.

Increased fall rates in nursing home residents after relocation to a new facility.

OBJECTIVE: To examine the change in fall rates after relocation of nursing home residents from one facility to another and to identify resident risk factors for changes in falls following relocation. DESIGN: Retrospective review of incident reports to identify falls, followed by chart review of a longitudinal cohort. SETTING: An academic nursing home whose residents and programs moved from a 125-year-old, 233-bed facility to a newly constructed 255-bed facility. PATIENTS: A total of 210 nursing home residents were moved from one facility to the other. Of these, 133 individuals who lived in the old facility for 9 months before the move and in the new facility for 6 months after the move formed the longitudinal cohort. RESULTS: In the 3 months after the move, the fall rate increased from 0.34 to 0.70 falls per resident per quarter in the entire nursing home population (P < .001) and subsequently returned to baseline. In the longitudinal subgroup the fall rate went from 0.26 to 0.60 (P < .005). Fall-related injuries in the longitudinal subgroup went from 0.058 injuries per resident per quarter at baseline to 0.15 (P < .001). However, the injury rate per fall did not change. There were no characteristics associated with being a faller in the quarter before the move. Dementia and not being bedbound were associated with being a faller after the move. Individuals who were ambulatory or wheelchair mobile had a significant risk of increasing the number of falls after the move, and individuals with dementia had a strong but insignificant trend in this direction. CONCLUSIONS: The incidence of falling doubled after relocation of nursing home residents to a new facility. An increase in falls was seen in individuals who were not bedbound. Although nursing home relocation may be a relatively uncommon occurrence, it is reasonable to infer that older individuals who change their living environments are at increased risk for falls and fall-related injuries.

Tensile testing of rodlike trabeculae excised from bovine femoral bone.

Individual trabeculae, rodlike in form, were excised from bovine femora and tested in tension to obtain stress-strain plots. Tensile grips were constructed to permit such small specimens to be tested and to avoid slippage during the test. Data were collected for 38 specimens. The results of these tests show that rodlike trabeculae obtained from the femora of young bovine animals have an average Young's modulus in tension of approximately 1 GPa. This value is an order of magnitude lower than the corresponding value for cortical bone in the diaphysis of the femur.

Patient perception of cardiovascular surgical patient education.

After surgery, 100 adult cardiac surgical patients participated in a study to determine what information was important to them and how well prepared they were. Questionnaires were administered 5 to 10 days after surgery and 1 to 4 weeks after discharge. In general patients received information that they perceived to be important, and they believed that preparation was more than adequate. Patients indicated a need to know more information about medication side effects than they received, and they did not desire as much information about emotional changes or sexual activity as the literature suggested.

Bi-institutional retrospective cohort study evaluating the incidence of osteosarcoma following tibial plateau levelling osteotomy (2000-2009).

OBJECTIVES: To evaluate the incidence and risk factors for occurrence of osteosarcoma (OSA) following tibial plateau levelling osteotomy (TPLO). METHODS: Medical records of client-owned dogs that underwent consecutive TPLO procedures at two institutions were retrospectively reviewed. Referring veterinarians and owners were contacted for follow-up. Each institutional cohort was assessed separately, and the incidence density rate and median time to occurrence of OSA at the TPLO site and at other sites were calculated. Marginal Cox regression was used to calculate hazard ratios and 95% confidence intervals for potential risk factors for occurrence of OSA. RESULTS: There were 472 CLINIC A (Colorado State University Veterinary Teaching Hospital) and 1992 CLINIC B (SAGE Centers for Veterinary Specialty and Emergency Care) TPLO cases with over one year of follow-up available. There were five and six dogs within the cohorts that developed OSA at the site of TPLO, and seven and 22 dogs that developed OSA at other anatomical sites, respectively. The incidence density rates of OSA at the TPLO site were 30.4 and 10.2 per 10,000 dog-years at risk, and other sites were 42.6 and 37.5 per 10,000 dog-years at risk. The median time to occurrence of OSA of TPLO site OSA was 4.6 and 4.4 years, which was longer than that of other site OSA of 2.9 and 3.4 years. CLINICAL SIGNIFICANCE: There is a low incidence of OSA following TPLO surgery. The longer time to occurrence for TPLO site OSA is similar to that for fracture-associated sarcoma, and could indicate a similar underlying pathophysiology rather than spontaneous OSA occurrence.

Attitudes, knowledge, and behavior of family physicians regarding depression in late life.

OBJECTIVES: To assess self-reported knowledge, attitudes, and behaviors of practicing community family physicians regarding identification and management of depression in late life. DESIGN: We sent a 3-page "fax-back" survey to 768 active physician members of the Maryland Academy of Family Physicians, Baltimore. MEASUREMENTS: We asked physicians to rate how confident they felt in evaluating several common medical conditions of late life, including depression. The questionnaire included items related to knowledge and treatment practices for depression in older adults. RESULTS: Two hundred fifteen usable surveys were returned. In general, physicians took responsibility for diagnosing and treating depression. Few physicians reported that they routinely referred the older patient to a psychiatrist to treat depression, and only half thought that consultation was helpful. Physicians responding to the survey were generally aware of alternative presentations of depression in elderly persons, and were well informed about the duration of treatment with medications for depression. Most were using selective serotonin reuptake inhibitors as first-line agents to treat depression. Physicians though that medications for depression were as effective for older patients as for younger patients, but were less optimistic about the effectiveness of psychotherapy. The barriers to identifying and treating depression in older patients most often mentioned by physicians were related to the atypical presentation of depression in older adults. More than half of the physicians rated themselves as "very confident" in evaluating depression. There were few differences in the responses of physicians with and those without a Certificate of Added Qualifications in geriatrics. CONCLUSIONS: Depression in late life remains a difficult clinical challenge for primary care physicians. These findings are particularly relevant in the face of recent efforts to increase collaboration between primary care physicians and mental health professionals.

Emergency medical service system development: results of the statewide emergency medical service Technical Assessment Program.

STUDY OBJECTIVE: The National Highway Traffic Safety Administration developed the EMS (emergency medical services) Technical Assessment Program to assist states in developing and improving their EMS systems. The main goals of this evaluation were to document the level of improvement in EMS system development following completion of the Technical Assessment Program and to identify necessary program improvements at the National Highway Traffic Safety Administration. DESIGN: Independent investigators retrospectively reviewed the information in Technical Assessment Program reports from 35 states that participated in the program during a 5-year period. RESULTS: Training and certification programs for prehospital personnel were the most well-developed elements of EMS systems. Conversely, comprehensive quality management and EMS system evaluation programs were almost uniformly absent (89% of states). Areas of need targeted for improvement included enabling legislation for EMS (60%) or trauma system development (69%), an improved mechanism to assess system resources (71%), an established or updated state EMS plan (80%), aging and unreliable communications equipment (89%), fully operational prehospital data collection systems (89%), and consistent medical oversight for all prehospital providers (92%). CONCLUSION: Program evaluation revealed that significant recommendation-based changes occurred in all components of EMS systems. The Technical Assessment Program is one tool that states can use to promote EMS system improvements.

EMS agenda for the future: where we are ... where we want to be. EMS Agenda for the Future Steering Committee.

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the "EMS Agenda for the Future." Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are Integration of Health Services, EMS Research, Legislation and Regulation, System Finance, Human Resources, Medical Direction, Education Systems, Public Education, Prevention, Public Access, Communication Systems, Clinical Care, Information Systems, and Evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.