A Comparative Evaluation of 2 Videolaryngoscopes as an Intubation Aid in a Simulated Difficult Airway: A Prospective Randomised Study.

OBJECTIVE: Several videolaryngoscopes have been developed for using in difficult airway. We conducted this study to evaluate the performance of McGrath® MAC and King Vision® videolaryngoscopes in a simulated difficult airway. METHODS: This prospective, randomised, comparative study was conducted in 140 surgical patients. Anaesthesia was administered as per standard protocol. A cervical collar was applied to simulate a difficult airway. Patients were randomised into 2 groups. In group M (n=70), laryngoscopy was performed first with King Vision® videolaryngoscope and second time with McGrath® MAC videolaryngoscope and trachea was intubated using the second device, while in group K (n=70), laryngoscopy was performed first with McGrath® MAC videolaryngoscope and second time with King Vision® videolaryngoscope and trachea was intubated using the second device. The laryngeal view, time taken for optimal laryngeal view, number of intubation attempts, ease of intubation, first attempt intubation success, time to tracheal intubation, haemodynamic parameters, and complications such as airway trauma, if any, were noted. RESULTS: Tracheal intubation was faster with McGrath® MAC (34.89 ± 3.7 seconds) compared to King Vision® videolaryngoscope (43.43 ± 4.3 seconds, P <.001) with comparable first attempt intubation success by 100% vs 97.1%, P =.496, respectively. The laryngeal view obtained with both the devices was comparable but the mean time taken for optimal laryngeal view was significantly longer with King Vision® videolaryngoscope, both in group M (P <.001) and group K (P <.001). Ease of intubation and complications were comparable in the 2 groups. CONCLUSION: McGrath® MAC videolaryngoscope in comparison to King Vision® videolaryngoscope resulted in a shorter time taken for optimal laryngeal view and time to tracheal intubation with comparable first attempt intubation success.

Replacing coal in Georgia's power plants with woody biomass to increase carbon benefit: A mixed integer linear programming model.

To combat climate change, reducing carbon emissions from coal consumption in the power sector can be an effective strategy. We developed a price-exogenous mixed integer linear optimization model satisfying both traditional timber demand in Georgia and its neighboring states (Alabama, Florida, North Carolina, South Carolina, and Tennessee) and additional bioenergy demand to replace coal in the power plants of Georgia for 50 years, maximizing social welfare. We used Forest Inventory & Analysis unit level yield of five forest types (planted softwood, natural softwood, upland hardwood, bottomland hardwood, and mixed forest), timber demand, and price information, and developed three scenarios. In the Baseline scenario, traditional annual timber demand (152 million tons of wood) was satisfied with no coal replacement. In Scenario 1, 100% coal (7.34 million tons annually) was replaced using pulpwood only, along with traditional demand. In Scenario 2, also with traditional demand, 100% coal was replaced using pulpwood and logging residues. It would require approximately 336 and 98 thousand acres of additional annual timberland harvested in Scenario 1 and Scenario 2, respectively, compared to Baseline (1280 thousand acres). During 50 years, a total of 9.3, 10.2, and 9.6 billion tons of timber was produced in Baseline, Scenario 1, and Scenario 2, respectively. About one-third of all torrefaction plants would be located in the central region of Georgia. The net change in stand carbon was positive in all three scenarios-the highest in Baseline (1330 million tons C), followed by Scenario 2 (1261 million tons C), and the lowest in Scenario 1 (872 million tons C). About 240 million tons of carbon was avoided by using biomass instead of coal in Scenario 1 and Scenario 2. In Baseline, with continued emission from coal usage in the power plant for 50 years (285 million tons C), net carbon benefit was 1046 million tons C. Replacing 100% of coal with both pulpwood and logging residues provided a net benefit of 1501 million tons C, about 43% higher compared to baseline.

Trade-offs Between the Value of Ecosystem Services and Connectivity Among Protected Areas in the Upper Chattahoochee Watershed.

The Upper Chattahoochee Watershed supplies most of the drinking water to the Atlanta Metropolitan Area, a region with one of the fastest urban growth rates in the United States. Smart conservation planning is necessary to conciliate urban development and the provision of critical ecosystem services (ESs) such as water quality, carbon storage, and wildlife habitat. We employed optimization models to compare the value of the ESs provided by alternative allocations of land parcels for conservation. We adopted boundary penalties to determine the trade-offs of choosing higher connectivity among parcels regarding economic values provided by carbon storage, wildlife habitat, and water quality. We used InVEST models to quantify and map ESs and value transfer to assign economic values to them. We set low and high ESs economic value bounds and discounted their values to perpetuity using 3% and 7% discount rates. Our results indicate that incorporating boundary penalties results in solutions with larger, fewer, and more connected parcels but yields lower economic benefits than unconstrained models. However, these differences are relatively small (between 2.6% and 7.3% loss in economic value). Additional transaction costs of purchasing more parcels and improving ecological networks provided by larger forest patches might justify the selection of solutions with higher connectivity. Decision-makers can use the developed models for estimating the economic cost of selecting connected parcels for conservation purposes at the landscape level.

Perspectives of four stakeholder groups about the participation of female forest landowners in forest management in Georgia, United States.

As the number of female forest landowners (FFLs) in the United States continues to rise, there is an increasing need to understand the perceptions of stakeholder groups about opportunities and challenges faced by FFLs in the context of sustainable forestland management. This study utilizes the technique of SWOT-AHP (Strengths, Weaknesses, Opportunities, and Treats-Analytical Hierarchy Process) to understand the perceptions of four stakeholder groups (FFLs, private foresters, government representatives, and non-profits) in Georgia-a significant forestry state located in the Southern United States. Sixteen factors (four under each SWOT category) were selected through a comprehensive literature review and detailed interviews with individuals from the identified stakeholder groups. A survey was created using these factors that asked stakeholders to compare them in their respective SWOT categories. An additional survey was created for each stakeholder group where survey participants compared the highest-ranking factors in each SWOT category. We found that all stakeholder groups prioritized weaknesses over the other SWOT categories. Results showed a significant need for relevant educational outreach programs that cater specifically to FFLs. Additionally, researchers found a need to promote the interest of future generations in forestland management as all stakeholder groups felt that limited interest from future generations was the most important threat. This study will directly feed into regional, national, and international attempts to increase the participation of minority family forest landowners in sustainable forest management through integrated forest policy development.

A framework for localizing global climate solutions and their carbon reduction potential.

Localized carbon reduction strategies are especially critical in states and regions that lack top-down climate leadership. This paper illustrates the use of coupled systems in assessments of subnational climate solutions with a case study of Georgia, a state located in the southeastern United States that does not have statewide climate goals or plans. The paper illustrates how robust place-specific plans for climate action could be derived from foundational global and national work and by embedding that research into the context of socio-ecological-technological systems. Our replicable methodology advances the traditional additive sectoral wedge analysis of carbon abatement potential by incorporating solution interdependencies and by spanning both carbon sources and sinks. We estimate that a system of 20 solutions could cut Georgia's carbon footprint by 35% in 2030 relative to a business-as-usual forecast and by 50% relative to Georgia's emissions in 2005. We also produce a carbon abatement cost curve that aligns private and social costs as well as benefits with units of avoided CO2-e. The solutions are affiliated with various social co-costs and co-benefits that highlight societal concerns extending beyond climate impacts, including public health, environmental quality, employment, and equity.

Analyzing the provision of ecosystem services by conservation easements and other protected and non-protected areas in the Upper Chattahoochee Watershed.

A conservation easement (CE) legally places a permanent restriction on the development of a private land parcel, and in turn, can provide tax benefits to the landowner. We used the modular toolset InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) to quantify provision of five ecosystem services (ESs) (carbon storage, wildlife habitat quality, nitrogen, phosphorus, and sediment exports) provided by CEs and other land typologies (Simulated Parcels, 1 km Buffer area, Watershed Average, Federal, State and Local Protected Areas) within the Upper Chattahoochee Watershed (UCW), which provides 72% of drinking water to about six million residents of the Atlanta Metropolitan Area and is experiencing one of fastest urban growth of the United States. Simulated Parcels would represent the land cover of CEs if the development restrictions were not in place. We conducted the analysis for 2001, 2006, 2011 and 2016. We aggregated all ESs into one index. Overall, CEs provided higher levels of ESs relative to the Simulated Parcels, 1 km Buffer, Watershed Average, and Local Protected Areas. However, the ESs from CEs were lower relative to Federal and State Protected Areas. Our results suggest that CEs are effective in ensuring the continuance of ESs within the UCW.

Impact of land cover on groundwater quality in the Upper Floridan Aquifer in Florida, United States.

Although agricultural lands are generally assumed to correlate negatively with groundwater quality, the intricate relationship between general land cover and contaminant concentrations present in an aquifer may vary substantially; contingent upon the land type, interacting factors, and scale considered. The Upper Floridan Aquifer (UFA) is a primary source of potable water supply for the state of Florida. The Suwannee River Water Management District (SRWMD), located in northcentral Florida, relies exclusively on the UFA for water supplies. Over much of the SRWMD in the UFA is unconfined, rendering it vulnerable to contamination from surface sources. This study analyses groundwater concentrations of Nitrate-Nitrogen (NO3-N) and Potassium (K) from shallow wells across the SRWMD for assessing the effect of different land covers on groundwater quality over time. Annual potentiometric surface maps were used to delineate semicircular recharge zones of 500 m, 1000 m, and 2000 m radii upstream of sampled well stations. Proportions of agriculture, forest, and urban lands were identified for each buffer zone using USDA Cropland Data Layer. Multivariate regression models were developed to infer relationships between land cover and NO3-N and K concentrations. Results show significant associations among land cover type, water table height, and groundwater quality parameters. Specifically, we find a large proportion of agricultural cover consistently associated with larger increases in groundwater pollutant loads relative to urban or forest cover across all models, after controlling for depth to water table. Our study suggests a need for widespread adoption of cost-effective agricultural best management practices (BMPs) that could help in securing regional water supply.

Determinants of Cookstoves and Fuel Choice Among Rural Households in India.

Roughly 2.8 billion people depend on solid fuels for cooking needs, resulting in a tremendous burden of disease from exposure to household air pollution. Despite decades of effort to promote cleaner cooking technologies, displacement of polluting technologies has progressed slowly. This paper describes results of a randomized controlled trial in which eight communities in two regions of rural India were presented with a range of cooking choices including improved solid fuel stoves and clean cooking options like liquefied petroleum gas (LPG) and induction stoves. Using survey data and logistic and multinomial regression, we identify factors associated with two outcomes: (1) pre-intervention ownership of non-solid fuel technologies and (2) household preferences for clean fuels from the range of cooking options offered. The analysis allows us to examine the influence of education, wealth, gender empowerment, stove pricing, and stove exchanges, among other variables. The majority of participants across all communities selected the cleanest options, LPG and induction, irrespective of price, but there is some variation in preferences. Wealth and higher caste stand out as significant predictors of pre-intervention ownership and non-solid fuel cooking options as well as preference for cleaner technologies offered through the intervention. The experimental treatments also influence preferences in some communities. When given the opportunity to exchange, communities in one region are more likely to choose solid fuel stoves (P < 0.05). Giving free stoves had mixed results; households in one region are more likely to select clean options (P < 0.05), but households in the other region prefer solid fuels (P < 0.10).

Understanding perceptions of stakeholder groups about Forestry Best Management Practices in Georgia.

Forestry Best Management Practices (BMPs) are critical in ensuring sustainable forest management in the United States because of their effectiveness in protecting water quality, reducing soil erosion, maintaining riparian habitat, and sustaining site productivity. The success of forestry BMPs depends heavily on coordination among primary stakeholder groups. It is important to understand perceptions of such groups for a successful forest policy formulation. We used the SWOT-AHP (Strengths, Weaknesses, Opportunities, and Threats analysis with the Analytical Hierarchy Process) framework to assess perceptions of three stakeholder groups (loggers, landowners, agency foresters) about forestry BMPs in Georgia, the largest roundwood producing state in the United States. The agency and logger stakeholder groups gave the highest priority to improved reputation under the strength category, whereas the landowner stakeholder group perceived sustainable forestry as the highest priority under the same category. Lack of landowner education was the highest priority under the weakness category for landowner and agency stakeholder groups, whereas the logger stakeholder group selected lack of trained personnel as the highest priority under the same category. Agency and landowner stakeholder groups gave the highest priority to training and education while loggers indicated maintenance of forest-based environmental benefits as their highest priority under the opportunity category. Finally, landowners and agency stakeholder groups perceived more regulations and restrictions as most significant in the threat category whereas the logger stakeholder group was most concerned about the insufficient accounting of cost sharing under the same category. Overall, selected stakeholder groups recognize the importance of forestry BMPs and had positive perceptions about them. A collaborative approach based on continuous feedback can streamline expectations of stakeholder groups about forestry BMPs in Georgia and several other states that are interested in maintaining high compliance rate of forestry BMPs for ensuring sustainable forest management.

Climate Change and Ecosystem Services Output Efficiency in Southern Loblolly Pine Forests.

Forests provide myriad ecosystem services that are vital to humanity. With climate change, we expect to see significant changes to forests that will alter the supply of these critical services and affect human well-being. To better understand the impacts of climate change on forest-based ecosystem services, we applied a data envelopment analysis method to assess plot-level efficiency in the provision of ecosystem services in Florida natural loblolly pine (Pinus taeda L.) forests. Using field data for n = 16 loblolly pine forest plots, including inputs such as site index, tree density, age, precipitation, and temperatures for each forest plot, we assessed the relative plot-level production of three ecosystem services: timber, carbon sequestered, and species richness. The results suggested that loblolly pine forests in Florida were largely inefficient in the provision of these ecosystem services under current climatic conditions. Climate change had a small negative impact on the loblolly pine forests efficiency in the provision of ecosystem services. In this context, we discussed the reduction of tree density that may not improve ecosystem services production.

Cost of abating greenhouse gas emissions with cellulosic ethanol.

We develop an integrated framework to determine and compare greenhouse gas (GHG) intensities and production costs of cellulosic ethanol derived from corn stover, switchgrass, and miscanthus grown on high and low quality soils for three representative counties in the Eastern United States. This information is critical for assessing the cost-effectiveness of utilizing cellulosic ethanol for mitigating GHG emissions and designing appropriate policy incentives to support cellulosic ethanol production nationwide. We find considerable variations in the GHG intensities and production costs of ethanol across feedstocks and locations mostly due to differences in yields and soil characteristics. As compared to gasoline, the GHG savings from miscanthus-based ethanol ranged between 130% and 156% whereas that from switchgrass ranged between 97% and 135%. The corresponding range for GHG savings with corn stover was 57% to 95% and marginally below the threshold of at least 60% for biofuels classified as cellulosic biofuels under the Renewable Fuels Standard. Estimates of the costs of producing ethanol relative to gasoline imply an abatement cost of at least $48 Mg(-1) of GHG emissions (carbon dioxide equivalent) abated and can be used to infer the minimum carbon tax rate needed to induce consumption of cellulosic ethanol.

COMPARATIVE EVALUATION OF PLAIN AND HYPERBARIC ROPIVACAINE IN PATIENTS UNDERGOING LOWER ABDOMINAL SURGERY UNDER SPINAL ANESTHESIA.

BACKGROUND: Preliminary work has shown that ropivacaine provides spinal anesthesia of shorter duration with greater sensory motor dissociation than bupivacaine, and may be of particular use in the day care surgery. Hypothetically, hyperbaric solution of ropivacaine could improve and shorten both sensory and motor block. MATERIAL AND METHODS: This prospective, randomized, double blind study was conducted on 80 patients undergoing lower abdominal surgeries. Patients either received 20.25 mg of plain ropivacaine (group A) or 20.25 mg of hyperbaric ropivacaine in 5% dextrose (group B). The extent and duration of sensory and motor block, haemodynamics, time to home readiness, and the time to first rescue analgesia were recorded. RESULTS: All patients in group B achieved sensory block at or above T10 dermatome in comparison to only 87.5% patients of group A. Analgesia at T10 was reached in 4 min (4-6 min) in group B vs. 10 min (6-16 min) in group A (p < 0.001). Patients in group B had a longer duration of analgesia at T10; 126 min (97-146 min) vs. 110 min (90-128 min) (p = 0.047). Median duration of sensory block from injection of the anesthetic to complete recovery (regression to S2 dermatome) was shorter in Group B than Group A, 273.5 min (258 - 289 min) vs. 300 min (290 - 312 min) (p < 0.001), as was the time to 2 segment regression 80 min (63-90 min) vs. 102 min (82-124 min) (p < 0.001). Duration of complete motor block (mean ± SD) was significantly less in group B, 93.06 ± 17.38 min compared to 139.89 ± 25.17 min (p < 0.001) in group A, as was the total duration of motor block (181.83 ± 30.21 min in group B vs. 254.91 ± 25.34 min in Group A; p < 0.001). Patients in Group B attained discharge criteria earlier as indicated by a shorter time to home readiness. Cardiovascular changes were unremarkable throughout, and similar in the two groups. There were no major sequelae. CONCLUSION: Addition of dextrose 5% to ropivacaine increases the speed of onset, block reliability, duration of useful block for surgery and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of T10.

Abatement cost of GHG emissions for wood-based electricity and ethanol at production and consumption levels.

Woody feedstocks will play a critical role in meeting the demand for biomass-based energy products in the US. We developed an integrated model using comparable system boundaries and common set of assumptions to ascertain unit cost and greenhouse gas (GHG) intensity of electricity and ethanol derived from slash pine (Pinus elliottii) at the production and consumption levels by considering existing automobile technologies. We also calculated abatement cost of greenhouse gas (GHG) emissions with respect to comparable energy products derived from fossil fuels. The production cost of electricity derived using wood chips was at least cheaper by 1 ¢ MJ-1 over electricity derived from wood pellets. The production cost of ethanol without any income from cogenerated electricity was costlier by about 0.7 ¢ MJ-1 than ethanol with income from cogenerated electricity. The production cost of electricity derived from wood chips was cheaper by at least 0.7 ¢ MJ-1 than the energy equivalent cost of ethanol produced in presence of cogenerated electricity. The cost of using ethanol as a fuel in a flex-fuel vehicle was at least higher by 6 ¢ km-1 than a comparable electric vehicle. The GHG intensity of per km distance traveled in a flex-fuel vehicle was greater or lower than an electric vehicle running on electricity derived from wood chips depending on presence and absence of GHG credits related with co-generated electricity. A carbon tax of at least $7 Mg CO2e-1 and $30 Mg CO2e-1 is needed to promote wood-based electricity and ethanol production in the US, respectively. The range of abatement cost of GHG emissions is significantly dependent on the harvest age and selected baseline especially for electricity generation.

Low demand for nontraditional cookstove technologies.

Biomass combustion with traditional cookstoves causes substantial environmental and health harm. Nontraditional cookstove technologies can be efficacious in reducing this adverse impact, but they are adopted and used at puzzlingly low rates. This study analyzes the determinants of low demand for nontraditional cookstoves in rural Bangladesh by using both stated preference (from a nationally representative survey of rural women) and revealed preference (assessed by conducting a cluster-randomized trial of cookstove prices) approaches. We find consistent evidence across both analyses suggesting that the women in rural Bangladesh do not perceive indoor air pollution as a significant health hazard, prioritize other basic developmental needs over nontraditional cookstoves, and overwhelmingly rely on a free traditional cookstove technology and are therefore not willing to pay much for a new nontraditional cookstove. Efforts to improve health and abate environmental harm by promoting nontraditional cookstoves may be more successful by designing and disseminating nontraditional cookstoves with features valued more highly by users, such as reduction of operating costs, even when those features are not directly related to the cookstoves' health and environmental impacts.