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- Khankeh, HR, et al.
(författare)
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The Barriers, Challenges, and Strategies of COVID-19 (SARS-CoV-2) Vaccine Acceptance: A Concurrent Mixed-Method Study in Tehran City, Iran
- 2021
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Ingår i: Vaccines. - : MDPI AG. - 2076-393X. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Acceptance and willingness to receive the vaccine are among the main factors in the success or failure of a health system in implementing the vaccination program. The present study was conducted in Tehran, the political and economic capital of Iran, to determine the acceptance of the COVID-19 vaccine and identify its associated factors, and explain the most important barriers and acceptance strategies for vaccination. This research was a concurrent quantitative and qualitative mixed-method study. In the quantitative part, 1200 individuals aged more than 18 years were selected from the households in 22 districts of Tehran City, with a multistage stratified cluster sampling method. Two questionnaires were used to evaluate the acceptance of the COVID-19 vaccine and vaccine acceptance determinants. The qualitative content analysis method addressed the influencing factors, as well as challenges and strategies related to the acceptance of the COVID-19 vaccine in four groups of Tehran inhabitants: the elderly, people with underlying diseases, healthcare workers, and the general population. The related data were simultaneously collected by applying in-depth semi-structural interviews and a data analysis process. Furthermore, we used the Graneheim and Lundman method for data analysis. We analyzed the data of 1200 people with a mean (SD) age of 46.4 (11.1) years, and approximately 58% of them were men. The vaccine acceptance was 83.6% (95% CI: 81.3–85.9). Among those who welcomed vaccination, 58% preferred the imported vaccines, 25% the Iranian ones, and 17% both. There was a significant association between the variables of age (adjusted odds ratio [AOR] = 1.72, 95% CI: 1.01–2.93), being single (AOR = 0.54, 95% CI: 0.41–0.91), moderate pharmacotherapy adherence (AOR = 0.58, 95% CI: 0.4–0.85), and the willingness to receive COVID-19 vaccine. Qualitative study after interviewing 45 people from four study groups showed an insufficient social trust in healthcare system officials, pharmaceutical and vaccine production companies; distrust in the effectiveness of the vaccines, concerns about the vaccine adverse effects, being tracked by microchips after vaccination, traditional anti-vaccination movements, the feeling the inessentiality of vaccination, and uncertainty about the fair distribution of the vaccine. These concerns were the main challenges addressed by the study groups. A good proportion of Tehran residents reported their willingness to receive the COVID-19 vaccine. Additionally, they expressed their critical concerns, such as insufficient trust in the healthcare system, vaccine safeties, and adverse effects that were the significant barriers to vaccine acceptance. It seems that conflicts raised by the shortage of vaccines and their import due to the sanctions have led to intense desire and demand in the general population, and especially the elderly, for vaccination. Besides, vaccination phobia in some individuals requires further investigations.
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2. |
- Khankeh, H, et al.
(författare)
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Comparison of vaccine hesitancy during the low and high points of COVID-19 in a population under international sanctions: A longitudinal mixed-methods study in Iran
- 2023
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Ingår i: Frontiers in public health. - : Frontiers Media SA. - 2296-2565. ; 10, s. 958899-
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Tidskriftsartikel (refereegranskat)abstract
- Along with the challenges of COVID-19 vaccine supply in low-income countries, vaccine hesitancy was another problem for the health system. The aim of this study was to deeply understand the challenges of vaccine acceptance, the vaccination process, and to compare the affecting vaccine acceptance in the high and low points of the epidemic in Iran.MethodsIn the qualitative part of this mixed-methods study, content analysis was used to investigate experiences and perceptions about COVID-19 vaccination in four groups. In the quantitative study, in March 2021 (low point), and on August 1, 2021 (high point), two population-based cross-sectional studies were performed in Tehran and its rural, with sample sizes of 1,200 and 1,872 people aged over 18 years, respectively. Multinomial (polytomous) logistic regression was used to determine the factors affecting hesitation and unwillingness to receive the vaccine.ResultsDisbelief in vaccine safety, vaccine distrust, ignorance and confusion, and inadequate facilities were the common reasons extracted in the two qualitative studies. At the low and high points of the epidemic, vaccine acceptance was 83.6% (95% CI: 81.3–85.9) and 65.8% (95% CI: 65.8–71.0), respectively. Residence in rural areas, (Odds Ratio: 0.44, p = 0.001), being a student (Odds Ratio: 0.41, p = 0.011), housewives (Odds Ratio: 0.63, p = 0.033), illiteracy (Odds Ratio: 4.44, p = 0.001), and having an underlying disease (Odds Ratio: 4.44, p = 0.001) were factors affecting on vaccine acceptance.DiscussionCounter-intuitively, acceptance did not increase at the peak of epidemic. The presence of obstacles, such as increased distrust in the effectiveness of vaccines due to the occurrence of multiple peaks in different vaccinated countries, as well as the influence of the media, anti-vaccine campaigns, and lack of proper communication about risks caused more hesitation. More investigation to understand how people accept or reject vaccine and its long term consequences is recommended.
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4. |
- Li, Wei, et al.
(författare)
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Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations
- 2017
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 14:22, s. 5053-5067
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Tidskriftsartikel (refereegranskat)abstract
- The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions and for ecosystem processes affected by LULCC. One drawback of LULCC emissions from DGVMs, however, is lack of observation constraint. Here, we propose a new method of using satellite-and inventory-based biomass observations to constrain historical cumulative LULCC emissions (E-LUC(c)) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and E-LUC(c). This method is applicable on the global and regional scale. The original DGVM estimates of E-LUC(c) range from 94 to 273 PgC during 1901-2012. After constraining by current biomass observations, we derive a best estimate of 155 +/- 50 PgC (1 sigma Gaussian error). The constrained LULCC emissions are higher than prior DGVM values in tropical regions but significantly lower in North America. Our emergent constraint approach independently verifies the median model estimate by biomass observations, giving support to the use of this estimate in carbon budget assessments. The uncertainty in the constrained Ec LUC is still relatively large because of the uncertainty in the biomass observations, and thus reduced uncertainty in addition to increased accuracy in biomass observations in the future will help improve the constraint. This constraint method can also be applied to evaluate the impact of land-based mitigation activities.
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- Aragão, Luiz E. O. C., et al.
(författare)
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21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 2003-2015. We show that despite a 76% decline in deforestation rates over the past 13 years, fire incidence increased by 36% during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km(2). Gross emissions from forest fires (989 +/- 504 Tg CO2 year(-1)) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process.
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7. |
- Le Toan, T., et al.
(författare)
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The BIOMASS mission: Mapping global forest biomass to better understand the terrestrial carbon cycle
- 2011
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Ingår i: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257. ; 115, s. 2850-2860
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Tidskriftsartikel (refereegranskat)abstract
- In response to the urgent need for improved mapping of global biomass and the lack of any current spacesystems capable of addressing this need, the BIOMASS mission was proposed to the European Space Agency forthe third cycle of Earth Explorer Core missions and was selected for Feasibility Study (Phase A) in March 2009.The objectives of the mission are 1) to quantify the magnitude and distribution of forest biomass globally toimprove resource assessment, carbon accounting and carbon models, and 2) tomonitor and quantify changesin terrestrial forest biomass globally, on an annual basis or better, leading to improved estimates of terrestrialcarbon sources (primarily from deforestation); and terrestrial carbon sinks due to forest regrowth andafforestation. These science objectives require the mission to measure above-ground forest biomass from 70° Nto 56° S at spatial scale of 100–200 m, with error not exceeding ±20% or ±10 t ha−1 and forest height witherror of ±4 m. To meet the measurement requirements, the mission will carry a P-Band polarimetric SAR(centre frequency 435 MHz with 6 MHz bandwidth) with interferometric capability, operating in a dawn-duskorbit with a constant incidence angle (in the range of 25°–35°) and a 25–45 day repeat cycle. During its 5-yearlifetime, the mission will be capable of providing both direct measurements of biomass derived from intensitydata and measurements of forest height derived from polarimetric interferometry. The design of the BIOMASSmission spins together two main observational strands: (1) the long heritage of airborne observations intropical, temperate and boreal forest that have demonstrated the capabilities of P-band SAR for measuringforest biomass; (2) new developments in recovery of forest structure including forest height from Pol-InSAR,and, crucially, the resistance of P-band to temporal decorrelation, which makes this frequency uniquelysuitable for biomass measurements with a single repeat-pass satellite. These two complementarymeasurement approaches are combined in the single BIOMASS sensor, and have the satisfying property thatincreasing biomass reduces the sensitivity of the former approach while increasing the sensitivity of the latter.This paper surveys the body of evidence built up over the last decade, from a wide range of airborneexperiments, which illustrates the ability of such a sensor to provide the required measurements.At present, the BIOMASS P-band radar appears to be the only sensor capable of providing the necessary globalknowledge about the world's forest biomass and its changes. In addition, this first chance to explore the Earth'senvironment with a long wavelength satellite SAR is expected to make yield new information in a range ofgeoscience areas, including subsurface structure in arid lands and polar ice, and forest inundation dynamics.
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8. |
- Madani, Nima, et al.
(författare)
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The Impacts of Climate and Wildfire on Ecosystem Gross Primary Productivity in Alaska
- 2021
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Ingår i: Journal of Geophysical Research: Biogeosciences. - 2169-8953. ; 126:6
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Tidskriftsartikel (refereegranskat)abstract
- The increase in wildfire occurrence and severity seen over the past decades in the boreal and Arctic biomes is expected to continue in the future in response to rapid climate change in this region. Recent studies documented positive trends in gross primary productivity (GPP) for Arctic boreal biomes driven by warming, but it is unclear how GPP trends are affected by wildfires. Here, we used satellite vegetation observations and environmental data with a diagnostic GPP model to analyze recovery from large fires in Alaska over the period 2000–2019. We confirmed earlier findings that warmer-than-average years provide favorable climate conditions for vegetation growth, leading to a GPP increase of 1 Tg C yr−1, contributed mainly from enhanced productivity in the early growing season. However, higher temperatures increase the risk of wildfire occurrence leading to direct carbon loss over a period of 1–3 years. While mortality related to severe wildfires reduce ecosystem productivity, post-fire productivity in moderately burned areas shows a significant positive trend. The rapid GPP recovery following fires reported here might be favorable for maintaining the region's net carbon sink, but wildfires can indirectly promote the release of long-term stored carbon in the permafrost. With the projected increase in severity and frequency of wildfires in the future, we expect a reduction of GPP and therefore amplification of climate warming in this region.
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9. |
- Quegan, S., et al.
(författare)
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The European Space Agency BIOMASS mission: Measuring forest above-ground biomass from space
- 2019
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Ingår i: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257. ; 227, s. 44-60
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Tidskriftsartikel (refereegranskat)abstract
- The primary objective of the European Space Agency's 7th Earth Explorer mission, BIOMASS, is to determine the worldwide distribution of forest above-ground biomass (AGB) in order to reduce the major uncertainties in calculations of carbon stocks and fluxes associated with the terrestrial biosphere, including carbon fluxes associated with Land Use Change, forest degradation and forest regrowth. To meet this objective it will carry, for the first time in space, a fully polarimetric P-band synthetic aperture radar (SAR). Three main products will be provided: global maps of both AGB and forest height, with a spatial resolution of 200 m, and maps of severe forest disturbance at 50 m resolution (where “global” is to be understood as subject to Space Object tracking radar restrictions). After launch in 2022, there will be a 3-month commissioning phase, followed by a 14-month phase during which there will be global coverage by SAR tomography. In the succeeding interferometric phase, global polarimetric interferometry Pol-InSAR coverage will be achieved every 7 months up to the end of the 5-year mission. Both Pol-InSAR and TomoSAR will be used to eliminate scattering from the ground (both direct and double bounce backscatter) in forests. In dense tropical forests AGB can then be estimated from the remaining volume scattering using non-linear inversion of a backscattering model. Airborne campaigns in the tropics also indicate that AGB is highly correlated with the backscatter from around 30 m above the ground, as measured by tomography. In contrast, double bounce scattering appears to carry important information about the AGB of boreal forests, so ground cancellation may not be appropriate and the best approach for such forests remains to be finalized. Several methods to exploit these new data in carbon cycle calculations have already been demonstrated. In addition, major mutual gains will be made by combining BIOMASS data with data from other missions that will measure forest biomass, structure, height and change, including the NASA Global Ecosystem Dynamics Investigation lidar deployed on the International Space Station after its launch in December 2018, and the NASA-ISRO NISAR L- and S-band SAR, due for launch in 2022. More generally, space-based measurements of biomass are a core component of a carbon cycle observation and modelling strategy developed by the Group on Earth Observations. Secondary objectives of the mission include imaging of sub-surface geological structures in arid environments, generation of a true Digital Terrain Model without biases caused by forest cover, and measurement of glacier and icesheet velocities. In addition, the operations needed for ionospheric correction of the data will allow very sensitive estimates of ionospheric Total Electron Content and its changes along the dawn-dusk orbit of the mission.
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10. |
- Quegan, S., et al.
(författare)
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The science and measurement concepts underlying the BIOMASS mission
- 2012
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Ingår i: Proc. IGARSS 2012, IEEE International Geoscience and Remote Sensing Symposium, Munich, Germany, 22-27 July 2012. - 2153-6996. - 9781467311588 ; , s. 5542-5545
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Konferensbidrag (refereegranskat)abstract
- The BIOMASS mission is designed to provide unique information on the biomass in the world's forests at spatial and temporal resolutions suitable for characterizing their dynamics and their contribution to carbon cycle estimates. To achieve this it combines biomass estimates from direct inversion of polarimetric backscattering coefficients with Pol-InSAR forest height estimates. The mission will also support important secondary objectives, including sub-surface imaging in arid zones, production of a bare-earth DTM and ice applications, and is optimized to be robust against environmental and ionospheric disturbances.
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