Setting Reference Levels Research Articles

Literature Review Dosis Radiasi Pada Pemeriksaan Radiografi Thorax Anak

Thorax radiology examination in children is one of the most frequently performed examinations in hospitals. However, the radiation used in this examination can potentially disrupt the growth and function of the child's imperfect organs. Therefore, patient radiation protection is very important to optimize the radiation dose received. The Nuclear Energy Regulatory Agency (BAPETEN) has set reference level values ​​in the form of IDRL (Indonesia Reference Level) for Diagnostic Radiology, including CT-Scan, Mammography and Fluorescence, as well as DRL (Diagnostic Reference Level) values ​​for children's thorax. The radiation dose received by the patient must be considered to avoid negative effects on the child's growth. This study aims to determine the measurement of radiation dose on chest radiography examinations of children. In this study, we will compare the radiation dose received by pediatric thorax patients based on the radiation dose standards set by UNSCEAR in 2000. Apart from that, we will also compare the radiation dose received by pediatric thorax patients with other studies. It is hoped that the results of this research will provide useful information and input for hospital diagnostic services in optimizing the radiation dose received by pediatric patients.

Optimisation of protection in the medical exposure of recurrent adult patients due to computed tomography procedures: development of recurrent exposures reference levels.

To assess the incidence (1year) and the cumulative incidence (3years) of the condition of patients accruing cumulative effective doses (CED) of ≥ 100mSv and their variability among different hospitals. To establish and validate a reference level for the CED in patients with recurrent exposures (RERL) and provide a RERL value. Data of CT exposure was collected in 9 similar hospitals. The database included 294,222 patient*years who underwent 442,278 CT exams in 3years. The incidence proportion of patients with CED ≥ 100mSv in a given year (I100;1) and the 3-year cumulative incidence of patients with CED ≥ 100mSv over 3 consecutive years (I100;3) were calculated and compared among different institutions. I100;1 ranged from a minimum of 0.1% to a maximum of 5.1%. The percentage of recurrent patients was quite uniform among centres ranging from 23 to 38%. The I100;3 ranged from a minimum of 1.1 to 11.4%. There was a strong positive correlation between the third quartile values of yearly CED and yearly incidence (r = 0.90; R2 = 0.81; p < 0.0001). RERL value in our study was found at 34.0mSv. The management of patients with recurrent exposures is highly variable among hospitals leading to a 50-fold variation in I100;1 and to a tenfold variation in I100;3. RERL could be established and used by taking as a RERL quantity the CED and as a RERL value the 75th percentile of the third quartiles of the distribution of the yearly CED obtained by surveying different hospitals. This is the first ever multicentre study that quantifies recurrent exposures in terms of incidence and cumulative incidence of patients with CED ≥ 100mSv. RERL establishment and use could benefit the optimisation of radioprotection of patients with recurrent exposures. This is the first multicentre study estimating yearly incidence and 3-year cumulative incidence of patients with cumulative effective doses ≥ 100mSv. In this study, a 50-fold inter centre variation between the maximum (5.1%) and the minimum value (0.1%) of yearly incidence of patients with cumulative effective doses ≥ 100mSv was reported. The range of the 3-year cumulative incidence extended from 1.1 to 11.4% (a tenfold variation) The third quartile of the yearly cumulative effective doses in a centre showed a strong positive correlation with the yearly incidence of patients with cumulative effective doses ≥ 100mSv, with a potential of being used to set reference levels for recurrent exposures.

Literature Review Dosis Radiasi pada Pemeriksaan Radiografi Thorax Anak

Thorax radiology examination in children is one of the most frequently performed examinations in hospitals. However, the radiation used in this examination can potentially disrupt the growth and function of the child's imperfect organs. Therefore, patient radiation protection is very important to optimize the radiation dose received. The Nuclear Energy Regulatory Agency (BAPETEN) has set reference level values ​​in the form of IDRL (Indonesia Reference Level) for Diagnostic Radiology, including CT-Scan, Mammography and Fluorescence, as well as DRL (Diagnostic Reference Level) values ​​for children's thorax. The radiation dose received by the patient must be considered to avoid negative effects on the child's growth. This study aims to determine the measurement of radiation dose on chest radiography examinations of children. In this study, we will compare the radiation dose received by pediatric thorax patients based on the radiation dose standards set by UNSCEAR in 2000. Apart from that, we will also compare the radiation dose received by pediatric thorax patients with other studies. It is hoped that the results of this research will provide useful information and input for hospital diagnostic services in optimizing the radiation dose received by pediatric patients.

Models of deforestation for setting reference levels in the context of REDD: A case study in the Peruvian Amazon

One of the main elements in the mechanisms proposed by REDD+ , is to pay countries (and then the users and/or forest owners, depending on each type of project), for real reductions in deforestation and the resulting GHG emissions, as well as to ensure other benefits, such as technical assistance and qualification, among others. To be able to estimate the emission reductions, it is necessary to establish a Reference Level either through different forms of a historical average or in the form of a BAU or “Business as Usual” scenario. In this sense, current proposals set the Reference Levels equal to historical deforestation, which apply another political logic to the predictions made by the Forest Transition (FT) theory. According to this theory, when using a simple historical extrapolation, it is possible that: “countries with a lot of forest and little deforestation”, lose in the initial stages of forest transition, while “countries with little forest and a lot of deforestation”, win in the later stages of the FT. Our study shows how the predictions of FT and other socio-economic variables can be incorporated into predictive models (historical trend), by including the forest area as an explanatory variable. Sub-national data from the 15 departments with forest cover in the Peruvian Amazon are used to develop 6 optional deforestation models for comparative purposes. It is observed that the most important predictive variable to explain current deforestation is historical deforestation. In the same way, it is observed that when applying and implementing econometric models with different variables, there are projections very close to the results of spatially explicit models for Peru (models that include spatial data for distance to roads, elevation, slope, distance to populated centers, among others). The variation of results is only 3–4%, so it can be concluded that the projections based on the historical trend considering the forest transition of each region and other socio-economic variables, are very good estimators of the deforestation expected in the future and are adequate to define the possible reductions by deforestation and degradation in the Peruvian Amazon or other areas with similar conditions.

Reference state, structure, regime shifts, and regulatory drivers in a coastal sea over the last century: The Central Baltic Sea case

AbstractThe occurrence of regime shifts in marine ecosystems has important implications for environmental legislation that requires setting reference levels and targets of quantitative restoration outcomes. The Baltic Sea ecosystem has undergone large changes in the 20th century related to anthropogenic pressures and climate variability, which have caused ecosystem reorganization. Here, we compiled historical information and identified relationships in our dataset using multivariate statistics and modeling across 31 biotic and abiotic variables from 1925 to 2005 in the Central Baltic Sea. We identified a series of ecosystem regime shifts in the 1930s, 1970s, and at the end of the 1980s/beginning of the 1990s. In the long term, the Central Baltic Sea showed a regime shift from a benthic to pelagic‐dominated state. Historically, benthic components played a significant role in trophic transfer, while in the more recent productive system pelagic–benthic coupling was weak and pelagic components dominated. Our analysis shows that for the entire time period, productivity, climate, and hydrography mainly affected the functioning of the food web, whereas fishing became important more recently. Eutrophication had far‐reaching direct and indirect impacts from a long‐term perspective and changed not only the trophic state of the system but also affected higher trophic levels. Our study also suggests a switch in regulatory drivers from salinity to oxygen. The “reference ecosystem” identified in our analysis may guide the establishment of an ecosystem state baseline and threshold values for ecosystem state indicators of the Central Baltic Sea.

A review of ecosystem condition accounts: lessons learned and options for further development

Ecosystem condition accounts are part of the System of Environmental-Economic Accounting – Experimental Ecosystem Accounting (SEEA EEA). An ecosystem condition account contains aggregated statistical information about the overall abiotic and biotic quality of an ecosystem at a policy relevant spatial scale. This article reviews 23 publicly-accessible reports undertaken or commissioned by government agencies, academic and non-government organisations that discuss or present an ecosystem condition account. This analysis revealed that ecosystem condition is usually reported for one or more ecosystem types, but there is little consistency in the terminology used to define ecosystem types. All case studies report variables or indicators that measure specific ecosystem characteristics in order to make inferences about the overall condition of ecosystems. All studies included biotic indicators and almost all studies included species-based indicators in the condition account. The thematic aggregation of indicators into a single composite index (or in a few composite sub-indices) is not a standard practice, but applied in about half of the studies. The definition and use of a reference condition or reference levels for specific indicators against which the reported condition can be evaluated is not a standard practice, but was applied in about half of the studies. Based on this analysis, we suggest the revision of the SEEA EEA to propose a globally-consistent typology of ecosystem types; to recommend a list of ecosystem condition indicators according to an agreed classification; to provide further guidance on aggregation methods and on the development of an ecosystem condition index that can be used to compare ecosystem condition across ecosystem types and across different accounting areas; to provide further guidance on how best to set reference levels and reference conditions against which the past, current and future ecosystem condition can be assessed; and to propose a standard set of statistical tables for reporting the condition account.

Setting reference levels and limits for good ecological condition in terrestrial ecosystems – Insights from a case study based on the IBECA approach

Abstract Effective evidence-based nature conservation and habitat management relies on developing and refining our methodological toolbox for detecting critical ecological changes at an early stage. This requires not only optimizing the use and integration of evidence from available data, but also optimizing methods for dealing with imperfect knowledge and data deficiencies. For policy and management relevance, ecological data are often synthesized into indicators, which are assessed against reference levels and limit values. Here we explore challenges and opportunities in defining ecological condition in relation to a reference condition reflecting intact ecosystems, as well as setting limit values for good ecological condition, linked to critical ecological thresholds in dose–response relationships between pressures and condition variables. These two concepts have been widely studied and implemented in aquatic sciences, but rarely in terrestrial systems. In this paper, we address practical considerations, theoretical challenges and possible solutions using different approaches to determine reference and limit values for good ecological condition in terrestrial ecosystems, based on empirical experiences from a case study in central Norway. We present five approaches for setting indicator reference values for intact ecosystems: absolute biophysical boundaries, reference areas, reference communities, ecosystem dynamics based models, and habitat availability based models. We further present four approaches for identifying indicator limit values for good ecological condition: empirically estimated values, statistical distributions, assumed linear relationships, and expert judgement-based limits. This exercise highlights the versatile and robust nature of ecological condition assessments based on reference and limit values for different management purposes, for situations where knowledge of the underlying relationships is lacking, and for situations limited by data availability.

Using Landsat observations (1988–2017) and Google Earth Engine to detect vegetation cover changes in rangelands - A first step towards identifying degraded lands for conservation

Globally, the area of agricultural land is shrinking in part due to environmental degradation. Acquisition and restoration of degraded lands no longer used for agriculture may present a major conservation opportunity with minimal social and political opposition. The ability to efficiently and accurately identify these lands from regional to global scales will aid conservation management, ultimately enhancing the global prospects of achieving the Sustainable Development Goals (SDGs). Remote Sensing provides a potential tool to identify areas where surface property changes can be mapped and linked with land degradation. In this study, we begin to tackle a small section of this challenge by presenting novel approach to mapping changes in vegetation cover amounts at the pixel level (30 m), using Google Earth Engine (GEE). We illustrate our approach across large-scale rangelands in Queensland Australia, using three decades of Landsat satellite imagery (1988–2017) along with field observations of land condition scores for validation. The approach used an existing method for dynamic reference cover to remove the rainfall variability and focused on the human management effects on the vegetation cover changes.Results showed the identified vegetation cover changes could be categorized into five classes of decrease, increase or stable cover compared with a set reference level, which was obtained from locations of the most persistent ground cover across all dry years. In total, vegetation cover decrease was observed in 20% of our study area, with similar portion of lands recovering and the rest (~60%) staying stable. The lands with decrease in vegetation cover, covering a considerable area of ~2 × 105 km2, exhibited a markedly reduced resilience to droughts. The accuracy assessment yielded an overall classification accuracy of 82.6% (±3.32 standard error) with 75.0% (±5.16%) and 70.0% (±4.13%) producer's and user's accuracy for areas experiencing a significant decrease in vegetation cover, respectively. Identifying areas of degraded land will require multiple stages of spatial data analysis and this work provided the first stage for identifying vegetation cover changes in large-scale rangeland environment, and provides a platform for future research and development to identify degraded lands and their utility for achieving conservation endeavours.

Integral Backstepping and Synergetic Control for Tracking of Infected Cells During Early Antiretroviral Therapy

Human Acquired Immune Deficiency Syndrome or Human Immunodeficiency Virus (HIV) Infection is a disease caused by a lentivirus known as the HIV virus. It alters the human immune system making him/her vulnerable to diseases and infections. The susceptibility worsens if the syndrome is not controlled through proper drug injection. In the literature, the researchers have proposed different control methodologies of drug injection so that the infected cells may reach the desired reference value. In this paper, nonlinear control algorithms based on the integral backstepping approach and synergetic control have been proposed to reduce steady-state error for robust tracking of infected helper T-cells to a set reference level for a deterministic model of HIV virus. The model is based on the mass balance of helper T-cells and viral load. System stability analysis has been proved with the help of a suitable Lyapunov-based theory. The viral load has been suppressed to zero. Both the numerical analysis and the simulations have been performed to validate the performance of proposed controllers. The proposed controllers have been compared with each other, with generic backstepping and backstepping embedded with sliding mode control techniques. They have been used to check the effect of efficiency of the drug on the control input. The simulations have been performed on MATLAB/Simulink.

Passive radon monitors with part-time sensitivity to radon

The recent European directive 59/2013 set reference levels for radon at working places. Since usually the personnel spend only part of the day (e. g. 8 h) at work, it is useful to have passive radon monitors that are sensitive only within a certain time window (e. g. the working hours). This work proposes a conceptual design of such a monitor and tests the feasibility of the approach. The design is based on a solid state nuclear track detector (SSNTD) that rotates over a radon absorber during the monitored period of the day. The SSNTD (Kodak Pathe LR-115 type II) has an energy window that makes it insensitive to 222Rn and 220Rn progeny plated-out on the surfaces. It only registers alpha particles of the absorbed 222Rn and its short-lived progeny 218Po, which is achieved by optimization of the absorber thickness. The absorber construction is further optimized to decrease the inertia of the signal. The modeling and the pilot experimental results show that with a composite absorber consisting of a stack of Makrofol N foils with thickness of less than 7 μm each, the inertia of the signal is less than 20 min. The estimated minimum detectable activity concentration (MDAC) for the proposed 222Rn monitor is about 15 Bq m−3 for year-long working time exposure (2000 h/year) or 60 Bq m−3 for 3- month exposure period (500 h).

Science-based approach for credible accounting of mitigation in managed forests

BackgroundThe credibility and effectiveness of country climate targets under the Paris Agreement requires that, in all greenhouse gas (GHG) sectors, the accounted mitigation outcomes reflect genuine deviations from the type and magnitude of activities generating emissions in the base year or baseline. This is challenging for the forestry sector, as the future net emissions can change irrespective of actual management activities, because of age-related stand dynamics resulting from past management and natural disturbances. The solution implemented under the Kyoto Protocol (2013–2020) was accounting mitigation as deviation from a projected (forward-looking) “forest reference level”, which considered the age-related dynamics but also allowed including the assumed future implementation of approved policies. This caused controversies, as unverifiable counterfactual scenarios with inflated future harvest could lead to credits where no change in management has actually occurred, or conversely, failing to reflect in the accounts a policy-driven increase in net emissions. Instead, here we describe an approach to set reference levels based on the projected continuation of documented historical forest management practice, i.e. reflecting age-related dynamics but not the future impact of policies. We illustrate a possible method to implement this approach at the level of the European Union (EU) using the Carbon Budget Model.ResultsUsing EU country data, we show that forest sinks between 2013 and 2016 were greater than that assumed in the 2013–2020 EU reference level under the Kyoto Protocol, which would lead to credits of 110–120 Mt CO2/year (capped at 70–80 Mt CO2/year, equivalent to 1.3% of 1990 EU total emissions). By modelling the continuation of management practice documented historically (2000–2009), we show that these credits are mostly due to the inclusion in the reference levels of policy-assumed harvest increases that never materialized. With our proposed approach, harvest is expected to increase (12% in 2030 at EU-level, relative to 2000–2009), but more slowly than in current forest reference levels, and only because of age-related dynamics, i.e. increased growing stocks in maturing forests.ConclusionsOur science-based approach, compatible with the EU post-2020 climate legislation, helps to ensure that only genuine deviations from the continuation of historically documented forest management practices are accounted toward climate targets, therefore enhancing the consistency and comparability across GHG sectors. It provides flexibility for countries to increase harvest in future reference levels when justified by age-related dynamics. It offers a policy-neutral solution to the polarized debate on forest accounting (especially on bioenergy) and supports the credibility of forest sector mitigation under the Paris Agreement.

Economic impacts of setting reference levels for the forest carbon sinks in the EU on the European forest sector

In order to meet the requirements of the Paris climate agreement, the EU plans to set new goals for forest carbon sinks. This may affect the future development potential in the wood using sectors in Europe and their contribution in the new circular bio-economy. We explore the potential consequences mainly on the forest sector in the region consisting of EU and Norway (EU + N), but also globally, that would arise if the countries in the EU + N constrained economic utilization of their forest resources. For the analysis, we use the global forest sector model EFI-GTM, which also incorporates the trade in wood and wood products.Due to the globally growing demand for forest products and available forest resources in the rest of the world (RoW) outside of the EU + N, the leakages of harvests, forest industry production and employment opportunities from EU + N to RoW would be considerable. Decreased wood harvests and forest industry production in the EU + N would raise the wood and forest industry product prices globally, and increase production and employment in the forest sector in RoW. Due to the harvest leakage, climate mitigation benefits of the policy in the form of forest carbon sinks in the EU + N would be considerably reduced. Also, there would be inter-sectoral carbon leakage, as part of the wood consumption would shift to more energy-demanding competing materials.

Understanding Measurement Reporting and Verification Systems for REDD+ as an Investment for Generating Carbon Benefits

Reducing emissions from forests—generating carbon credits—in return for REDD+ (Reducing Emissions from Deforestation and forest Degradation) payments represents a primary objective of forestry and development projects worldwide. Setting reference levels (RLs), establishing a target for emission reductions from avoided deforestation and degradation, and implementing an efficient monitoring system underlie effective REDD+ projects, as they are key factors that affect the generation of carbon credits. We analyzed the interdependencies among these factors and their respective weights in generating carbon credits. Our findings show that the amounts of avoided emissions under a REDD+ scheme mainly vary according to the monitoring technique adopted; nevertheless, RLs have a nearly equal influence. The target for reduction of emissions showed a relatively minor impact on the generation of carbon credits, particularly when coupled with low RLs. Uncertainties in forest monitoring can severely undermine the derived allocation of benefits, such as the REDD+ results-based payments to developing countries. Combining statistically-sound sampling designs with Lidar data provides a means to reduce uncertainties and likewise increases the amount of accountable carbon credits that can be claimed. This combined approach requires large financial resources; we found that results-based payments can potentially pay-off the necessary investment in technologies that would enable accurate and precise estimates of activity data and emission factors. Conceiving of measurement, reporting and verification (MRV) systems as investments is an opportunity for tropical countries in particular to implement well-defined, long-term forest monitoring strategies.

Gray detector, a dose monitoring software for radiology departments

The aim of this work is to present the gray detector, a web-based patient radiation dose monitoring software developed to answer on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure, (Council Directive 2013/59/Euratom) This software provides to capture, track and report radiation dose directly from any imaging device or PACS, completely vendor neutral solution, and it is the simple yet scalable way to document dose, set reference levels, benchmark performance, manage protocols and identify outliers. The solution gives the possibility to integrate all the information about the dose with the data in RIS: in this way there is the possibility to context the dosimetric data and to follow the optimization of the radiologic risk management and the ratio risk/benefit of the image. Gray detector manages all diagnostic modality tracking and archiving all dosimetry data: CT, Mammography, Interventional, Cardiovascular, Radiography and Nuclear Medicine. It is compatible with DICOM SR and DICOM MPPS messages, Query & Retrieve DICOM image header (for non MSSP/SR DICOM modality), to extract all relevant information from dose and maximize data collection, crossing the fundamental data stored in the RIS database. All data collected can be viewed through customizable charts or exported according to standard formats gray detector has an “alert system”, that gives the possibility to send email and display messages when the modality gives an over dose, based on DRL The integration of the gray detector with information systems, may improve clinical quality performance in diagnostic imaging The aim of this work is to present the gray detector, a web-based patient radiation dose monitoring software developed to answer on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure, (Council Directive 2013/59/Euratom) This software provides to capture, track and report radiation dose directly from any imaging device or PACS, completely vendor neutral solution, and it is the simple yet scalable way to document dose, set reference levels, benchmark performance, manage protocols and identify outliers. The solution gives the possibility to integrate all the information about the dose with the data in RIS: in this way there is the possibility to context the dosimetric data and to follow the optimization of the radiologic risk management and the ratio risk/benefit of the image. Gray detector manages all diagnostic modality tracking and archiving all dosimetry data: CT, Mammography, Interventional, Cardiovascular, Radiography and Nuclear Medicine. It is compatible with DICOM SR and DICOM MPPS messages, Query & Retrieve DICOM image header (for non MSSP/SR DICOM modality), to extract all relevant information from dose and maximize data collection, crossing the fundamental data stored in the RIS database. All data collected can be viewed through customizable charts or exported according to standard formats gray detector has an “alert system”, that gives the possibility to send email and display messages when the modality gives an over dose, based on DRL The integration of the gray detector with information systems, may improve clinical quality performance in diagnostic imaging

TU‐D‐201‐08: Experience Complying with The Joint Commission Element of Performance On Radiation Dose Index Monitoring

Purpose:A new Joint Commission element of performance effective July 2015 requires incidents where the radiation dose index exceeds a defined level be reviewed, analyzed and compared to external benchmarks. This work offers a comprehensive review of the CT exams in which the notification level was exceeded and the reason at one academic medical center. This review may help other institutions set reference levels at clinically relevant values.Methods:Radiation Dose Structured Reports from each of the 5 diagnostic CT scanners at our institution are automatically sent to our radiation dose index monitoring software platform, Radimetrics from Bayer Healthcare. Global notification levels for CTDIvol and DLP were configured in Radimetrics for head, chest and abdomen studies for 0–2 year old, 2–13 year old and adult age categories. Global CTDIvol notification levels were set lower than the AAPM recommended values. Additional notification levels were configured for specific protocols that do not use AEC or have better or limited image quality requirements. Notifications of exams exceeding the global or protocol specific notification levels were reviewed on an ongoing basis by a Qualified Medical Physicist and the reason(s) for the acquisition or exam exceeding the level recorded.Results:Out of 80 notifications for acquisitions or exams exceeding notification levels over an 8 month period, 72 occurred due to large patients or due to implants or external hardware in the scan range. Four instances of the incorrect protocol being selected were recorded and 4 instances of incorrect manual technique application were observed.Conclusion:Properly configured notification levels, even below those recommended by AAPM, produce few dose notifications on modern scanners using AEC and/or iterative reconstruction. Using SSDE instead of CTDI for notifications may provide more clinically relevant data on exams well above or below the clinical norm for dose and image quality.Mark P. Supanich: Global Informatics Advisory Board Member: Bayer HealthCare

Multilevel governance challenges in transitioning towards a national approach for REDD+: evidence from 23 subnational REDD+ initiatives

Although REDD+ was conceived as a national approach to reducing emissions from deforestation and degradation, many of the early advances have been at the subnational level. It is critical to link these subnational efforts to emerging national REDD+ frameworks, including with respect to finance and benefit distribution, setting reference levels, measurement, reporting and verification (MRV), land policy and safeguards. We use evidence from interviews with proponents from 23 subnational REDD+ initiatives in six countries to characterize the multilevel governance challenges for REDD+. We analyse the differences in perceived challenges between subnational jurisdictional programs and project-based initiatives, and then analyse proponents’ perceptions of the relationship between government policies at multiple levels and these REDD+ initiatives. We find important multilevel governance challenges related to vertical coordination and information sharing and horizontal and inter-sectoral tensions, as well as concerns over accountability, equity and justice. Though the shift to a nested, jurisdictional or national REDD+ is sometimes approached as a technical design issue, this must be accompanied by an understanding of the interests and power relations among actors at different levels. We outline challenges and suggest priority areas for future research and policy, as countries move towards a national REDD+ system.

Multilevel governance challenges in transitioning towards a national approach for REDD+: evidence from 23 subnational REDD+ initiatives

Although REDD+ was conceived as a national approach to reducing emissions from deforestation and degradation, many of the early advances have been at the subnational level. It is critical to link these subnational efforts to emerging national REDD+ frameworks, including with respect to finance and benefit distribution, setting reference levels, measurement, reporting and verification (MRV), land policy and safeguards. We use evidence from interviews with proponents from 23 subnational REDD+ initiatives in six countries to characterize the multilevel governance challenges for REDD+. We analyse the differences in perceived challenges between subnational jurisdictional programs and project-based initiatives, and then analyse proponents’ perceptions of the relationship between government policies at multiple levels and these REDD+ initiatives. We find important multilevel governance challenges related to vertical coordination and information sharing and horizontal and inter-sectoral tensions, as well as concerns over accountability, equity and justice. Though the shift to a nested, jurisdictional or national REDD+ is sometimes approached as a technical design issue, this must be accompanied by an understanding of the interests and power relations among actors at different levels. We outline challenges and suggest priority areas for future research and policy, as countries move towards a national REDD+ system.

Global patterns in ecological indicators of marine food webs: a modelling approach.

BackgroundEcological attributes estimated from food web models have the potential to be indicators of good environmental status given their capabilities to describe redundancy, food web changes, and sensitivity to fishing. They can be used as a baseline to show how they might be modified in the future with human impacts such as climate change, acidification, eutrophication, or overfishing.MethodologyIn this study ecological network analysis indicators of 105 marine food web models were tested for variation with traits such as ecosystem type, latitude, ocean basin, depth, size, time period, and exploitation state, whilst also considering structural properties of the models such as number of linkages, number of living functional groups or total number of functional groups as covariate factors.Principal findingsEight indicators were robust to model construction: relative ascendency; relative overhead; redundancy; total systems throughput (TST); primary production/TST; consumption/TST; export/TST; and total biomass of the community. Large-scale differences were seen in the ecosystems of the Atlantic and Pacific Oceans, with the Western Atlantic being more complex with an increased ability to mitigate impacts, while the Eastern Atlantic showed lower internal complexity. In addition, the Eastern Pacific was less organised than the Eastern Atlantic although both of these systems had increased primary production as eastern boundary current systems. Differences by ecosystem type highlighted coral reefs as having the largest energy flow and total biomass per unit of surface, while lagoons, estuaries, and bays had lower transfer efficiencies and higher recycling. These differences prevailed over time, although some traits changed with fishing intensity. Keystone groups were mainly higher trophic level species with mostly top-down effects, while structural/dominant groups were mainly lower trophic level groups (benthic primary producers such as seagrass and macroalgae, and invertebrates). Keystone groups were prevalent in estuarine or small/shallow systems, and in systems with reduced fishing pressure. Changes to the abundance of key functional groups might have significant implications for the functioning of ecosystems and should be avoided through management.Conclusion/significanceOur results provide additional understanding of patterns of structural and functional indicators in different ecosystems. Ecosystem traits such as type, size, depth, and location need to be accounted for when setting reference levels as these affect absolute values of ecological indicators. Therefore, establishing absolute reference values for ecosystem indicators may not be suitable to the ecosystem-based, precautionary approach. Reference levels for ecosystem indicators should be developed for individual ecosystems or ecosystems with the same typologies (similar location, ecosystem type, etc.) and not benchmarked against all other ecosystems.

SU‐E‐I‐31: Moving From Image Intensifier to Flat Panel Detector in Interventional Radiology: Initial Experiences in a Tertiary Referral Center in India

Purpose: To audit radiation doses imparted to patients from interventional procedures performed in image intensifier and flat panel based interventional systems in a tertiary referral center in India. Methods: Forty cerebral angiographies were performed using Siemens Multistar top Image intensifier (II) and nine using Artis Zee flat panel detector (FPD) based angiographic systems. Dose area product (DAP) meter was used to measure dose imparted to patients during interventional procedures. Dose audit involved assessment of radiation dose, exposure parameters and image quality relevant to the examination. Copper filtration of 0.2mm was selected in the II based system, whereas 0.6mm copper filters were selected in FPD system. Subjective evaluation of image quality was performed by the interventionalists performing the procedure. Results: The mean DAP values for cerebral angiography using II and FPD systems were 127.5 (32.96 to 366.47) and 94.6 (26.31 to 228.68) Gy cm2 respectively. Dose reduction of about 26 % without sacrificing diagnostic information was achieved using FPD compared to the II system. Conclusion: It is necessary to orient the interventional staff to strictly adhere to low dose protocols so that inadvertent selection of preset protocols may impart high doses to patients. Further data collection on several other interventions is necessary in order set reference levels for Indian adult. At present using low dose protocols involving high filtration does not degrade image quality and are suggestive for use in FPD systems for the Indian adult.

Homegardens as a Multi-functional Land-Use Strategy in Sri Lanka with Focus on Carbon Sequestration

This paper explores the concept of homegardens and their potential functions as strategic elements in land-use planning, and adaptation and mitigation to climate change in Sri Lanka. The ancient and locally adapted agroforestry system of homegardens is presently estimated to occupy nearly 15 % of the land area in Sri Lanka and is described in the scientific literature to offer several ecosystem services to its users; such as climate regulation, protection against natural hazards, enhanced land productivity and biological diversity, increased crop diversity and food security for rural poor and hence reduced vulnerability to climate change. Our results, based on a limited sample size, indicate that the homegardens also store significant amount of carbon, with above ground biomass carbon stocks in dry zone homegardens (n = 8) ranging from 10 to 55 megagrams of carbon per hectare (Mg C ha(-1)) with a mean value of 35 Mg C ha(-1), whereas carbon stocks in wet zone homegardens (n = 4) range from 48 to 145 Mg C ha(-1) with a mean value of 87 Mg C ha(-1). This implies that homegardens may contain a significant fraction of the total above ground biomass carbon stock in the terrestrial system in Sri Lanka, and from our estimates its share has increased from almost one-sixth in 1992 to nearly one-fifth in 2010. In the light of current discussions on reducing emissions from deforestation and forest degradation (REDD+), the concept of homegardens in Sri Lanka provides interesting aspects to the debate and future research in terms of forest definitions, setting reference levels, and general sustainability.