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Huang K, Brandt M, Hiernaux P, Tucker CJ, Rasmussen LV, Reiner F, Li S, Kariryaa A, Mugabowindekwe M, den Braber B, Small J, Sino S, Fensholt R. Mapping every adult baobab (Adansonia digitata L.) across the Sahel and relationships to rural livelihoods. Nat Ecol Evol 2024; 8:1632-1640. [PMID: 39054350 DOI: 10.1038/s41559-024-02483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 05/24/2024] [Indexed: 07/27/2024]
Abstract
The baobab tree (Adansonia digitata L.) is an integral part of rural livelihoods throughout the African continent. However, the combined effects of climate change and increasing global demand for baobab products are currently exerting pressure on the sustainable utilization of these resources. Here we use sub-metre-resolution satellite imagery to identify the presence of nearly 2.8 million (underestimation bias 27.1%) baobab trees in the Sahel, a dryland region of 2.4 million km2. This achievement is considered an essential step towards an improved management and monitoring system of valuable woody species. Using Senegal as a case country, we find that 94% of rural buildings have at least one baobab tree in their immediate surroundings and that the abundance of baobabs is associated with a higher likelihood of people consuming a highly nutritious food group: dark green leafy vegetables. The generated database showcases the feasibility of mapping the location of single tree species at a sub-continental scale, providing vital information in times when deforestation and climate change cause the extinction of numerous tree species.
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Fan L, Cui T, Wigneron JP, Ciais P, Sitch S, Brandt M, Li X, Niu S, Xiao X, Chave J, Wu C, Li W, Yuan W, Xing Z, Li X, Wang M, Liu X, Chen X, Qin Y, Yang H, Tang Q, Li Y, Ma M, Fensholt R. Dominant role of the non-forest woody vegetation in the post 2015/16 El Niño tropical carbon recovery. GLOBAL CHANGE BIOLOGY 2024; 30:e17423. [PMID: 39010751 DOI: 10.1111/gcb.17423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 06/27/2024] [Accepted: 07/02/2024] [Indexed: 07/17/2024]
Abstract
The extreme dry and hot 2015/16 El Niño episode caused large losses in tropical live aboveground carbon (AGC) stocks. Followed by climatic conditions conducive to high vegetation productivity since 2016, tropical AGC are expected to recover from large losses during the El Niño episode; however, the recovery rate and its spatial distribution remain unknown. Here, we used low-frequency microwave satellite data to track AGC changes, and showed that tropical AGC stocks returned to pre-El Niño levels by the end of 2020, resulting in an AGC sink of0.18 0.14 0.26 $$ {0.18}_{0.14}^{0.26} $$ Pg C year-1 during 2014-2020. This sink was dominated by strong AGC increases (0.61 0.49 0.84 $$ {0.61}_{0.49}^{0.84} $$ Pg C year-1) in non-forest woody vegetation during 2016-2020, compensating the forest AGC losses attributed to the El Niño event, forest loss, and degradation. Our findings highlight that non-forest woody vegetation is an increasingly important contributor to interannual to decadal variability in the global carbon cycle.
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Tong X, Zhang X, Fensholt R, Jensen PRD, Li S, Larsen MN, Reiner F, Tian F, Brandt M. Global area boom for greenhouse cultivation revealed by satellite mapping. NATURE FOOD 2024; 5:513-523. [PMID: 38741004 DOI: 10.1038/s43016-024-00985-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 04/16/2024] [Indexed: 05/16/2024]
Abstract
Greenhouse cultivation has been expanding rapidly in recent years, yet little knowledge exists on its global extent and expansion. Using commercial and freely available satellite data combined with artificial intelligence techniques, we present a global assessment of greenhouse cultivation coverage and map 1.3 million hectares of greenhouse infrastructures in 2019, a much larger extent than previously estimated. Our analysis includes both large (61%) and small-scale (39%) greenhouse infrastructures. Examining the temporal development of the 65 largest clusters (>1,500 ha), we show a recent upsurge in greenhouse cultivation in the Global South since the 2000s, including a dramatic increase in China, accounting for 60% of the global coverage. We emphasize the potential of greenhouse infrastructures to enhance food security but raise awareness of the uncertain environmental and social implications that may arise from this expansion. We further highlight the gap in spatio-temporal datasets for supporting future research agendas on this critical topic.
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Göbel S, Braun AS, Hahad O, von Henning U, Brandt M, Keller K, Gaida MM, Gori T, Schultheiss HP, Escher F, Münzel T, Wenzel P. Etiologies and predictors of mortality in an all-comer population of patients with non-ischemic heart failure. Clin Res Cardiol 2024; 113:737-749. [PMID: 38224373 PMCID: PMC11026225 DOI: 10.1007/s00392-023-02354-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 11/29/2023] [Indexed: 01/16/2024]
Abstract
BACKGROUND Despite progress in diagnosis and therapy of heart failure (HF), etiology and risk stratification remain elusive in many patients. METHODS The My Biopsy HF Study (German clinical trials register number: DRKS22178) is a retrospective monocentric study investigating an all-comer population of patients with unexplained HF based on a thorough workup including endomyocardial biopsy (EMB). RESULTS 655 patients (70.9% men, median age 55 [45/66] years) with non-ischemic, non-valvular HF were included in the analyses. 489 patients were diagnosed with HF with reduced ejection fraction (HFrEF), 52 patients with HF with mildly reduced ejection fraction (HFmrEF) and 114 patients with HF with preserved ejection fraction (HFpEF). After a median follow-up of 4.6 (2.5/6.6) years, 94 deaths were enumerated (HFrEF: 68; HFmrEF: 8; HFpEF: 18), equating to mortality rates of 3.3% and 11.6% for patients with HFrEF, 7.7% and 15.4% for patients with HFmrEF and 5.3% and 11.4% for patients with HFpEF after 1 and 5 years, respectively. In EMB, we detected a variety of putative etiologies of HF, including incidental cardiac amyloidosis (CA, 5.8%). In multivariate logistic regression analysis adjusting for age, sex and comorbidities only CA, age and NYHA functional class III + IV remained independently associated with all-cause mortality (CA: HRperui 3.13, 95% CI 1.5-6.51; p = 0.002). CONCLUSIONS In an all-comer population of patients presenting with HF of unknown etiology, incidental finding of CA stands out to be independently associated with all-cause mortality. Our findings suggest that prospective trials would be helpful to test the added value of a systematic and holistic work-up of HF of unknown etiology.
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Lu T, Zhang W, Abel C, Horion S, Brandt M, Huang K, Fensholt R. Changes in vegetation-water response in the Sahel-Sudan during recent decades. JOURNAL OF HYDROLOGY. REGIONAL STUDIES 2024; 52:101672. [PMID: 38577223 PMCID: PMC10993624 DOI: 10.1016/j.ejrh.2024.101672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/17/2023] [Accepted: 01/15/2024] [Indexed: 04/06/2024]
Abstract
Study region The Africa Sahel-Sudan region, defined by annual rainfall between 150 and 1200 mm. Study focus Understanding the mechanism of vegetation response to water availability could help mitigate the potential adverse effects of climate change on global dryland ecosystems. In the Sahel-Sudan region, spatio-temporal changes and drivers of the vegetation-water response remain unclear. This study employs long-term satellite water and vegetation products as proxies of water availability and vegetation productivity to analyze changes in vegetation-water sensitivity and the cumulative effect duration (CED) representing a measure of the legacy effect of the impact of water constraints on vegetation. A random forest model was subsequently used to analyze potential climatic drivers of the observed vegetation response. New hydrological insights for the region During 1982-2016 we found a significant decrease (p < 0.05) in the sensitivity of vegetation productivity to water constraints in 26% of the Sahel-Sudan region, while 9% of the area showed a significantly increased sensitivity, mainly in the sub-humid zone. We further showed that CED significantly increased and decreased, respectively in around 9% of the study area in both cases. Our climatic driver attribution analysis suggested the existence of varying underlying mechanisms governing vegetation productivity in response to water deficit across the Sahel-Sudan dryland ecosystems. Our findings emphasize the need for diverse strategies in sustainable ecosystem management to effectively address these varying mechanisms.
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Happl B, Balber T, Heffeter P, Denk C, Welch JM, Köster U, Alliot C, Bonraisin AC, Brandt M, Haddad F, Sterba JH, Kandioller W, Mitterhauser M, Hacker M, Keppler BK, Mindt TL. Synthesis and preclinical evaluation of BOLD-100 radiolabeled with ruthenium-97 and ruthenium-103. Dalton Trans 2024; 53:6031-6040. [PMID: 38470348 DOI: 10.1039/d4dt00118d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
BOLD-100 (formerly IT-139, KP1339), a well-established chemotherapeutic agent, is currently being investigated in clinical trials for the treatment of gastric, pancreatic, colorectal, and bile duct cancer. Despite numerous studies, the exact mode of action is still the subject of discussions. Radiolabeled BOLD-100 could be a powerful tool to clarify pharmacokinetic pathways of the compound and to predict therapy responses in patients using nuclear molecular imaging prior to the therapy. In this study, the radiosyntheses of carrier-added (c.a.) [97/103Ru]BOLD-100 were performed with the two ruthenium isotopes ruthenium-103 (103Ru; β-, γ) and ruthenium-97 (97Ru; EC, γ), of which in particular the latter isotope is suitable for imaging by single-photon emission computed tomography (SPECT). To identify the best tumor-to-background ratio for diagnostic imaging, biodistribution studies were performed with two different injected doses of c.a. [103Ru]BOLD-100 (3 and 30 mg kg-1) in Balb/c mice bearing CT26 allografts over a time period of 72 h. Additionally, ex vivo autoradiography of the tumors (24 h p.i.) was conducted. Our results indicate that the higher injected dose (30 mg kg-1) leads to more unspecific accumulation of the compound in non-targeted tissue, which is likely due to an overload of the albumin transport system. It was also shown that lower amounts of injected c.a. [103Ru]BOLD-100 resulted in a relatively higher tumor uptake and, therefore, a better tumor-to-background ratio, which are encouraging results for future imaging studies using c.a. [97Ru]BOLD-100.
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Herzog T, Brandt M, Trinchi A, Sola A, Hagenlocher C, Molotnikov A. Defect detection by multi-axis infrared process monitoring of laser beam directed energy deposition. Sci Rep 2024; 14:3861. [PMID: 38360826 PMCID: PMC10869730 DOI: 10.1038/s41598-024-53931-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 02/06/2024] [Indexed: 02/17/2024] Open
Abstract
Laser beam directed energy deposition (DED-LB) is an attractive additive manufacturing technique to produce versatile and complex 3D structures on demand, apply a cladding, or repair local defects. However, the quality of manufactured parts is difficult to assess by inspection prior to completion, and parts must be extensively inspected post-production to ensure conformance. Consequently, critical defects occurring during the build go undetected. In this work, a new monitoring system combining three infrared cameras along different optical axes capable of monitoring melt pool geometry and vertical displacement throughout deposition is reported. By combining multiple sensor data, an automated algorithm is developed which is capable of identifying the formation of structural features and defects. An intersecting, thin-walled geometry is used to demonstrate the capability of the system to detect process-induced porosity in samples with narrow intersection angles, which is validated using micro-CT observations. The recorded results indicate the root cause of this process-induced porosity at the intersection, and it is shown that advanced toolpath planning can eliminate such defects. The presented methodology demonstrates the value of multi-axis monitoring for identifying both defects and structural features, providing an advancement towards automated detection and alert systems in DED-LB.
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Haußmann R, Homeyer P, Haußmann M, Sauer C, Linn J, Donix M, Brandt M, Puetz V. [Analysis of the prevalence of anticoagulant therapy in patients with cognitive disorders and cerebral amyloid angiopathy (CAA)]. DER NERVENARZT 2024; 95:146-151. [PMID: 37747503 PMCID: PMC10850242 DOI: 10.1007/s00115-023-01547-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/11/2023] [Indexed: 09/26/2023]
Abstract
OBJECTIVES To investigate the prevalence of coincident anticoagulation in patients with cognitive disorders and possible or probable cerebral amyloid angiopathy (CAA) as well as the relationship between the presence of oral anticoagulation and CAA-specific lesion load. MATERIALS AND METHODS Patients with subjective cognitive decline (SCD), amnestic and non-amnestic mild cognitive impairment (aMCI/naMCI), Alzheimer's disease (AD), mixed dementia (MD) and vascular dementia (VD) who presented to our outpatient dementia clinic between February 2016 and October 2020 were included in this retrospective analysis. Patients underwent cranial magnetic resonance imaging (MRI). MRI data sets were analyzed regarding the presence of CAA-related MRI biomarkers to determine CAA prevalence. Presence of anticoagulant therapy was determined by chart review. RESULTS Within the study period, 458 patients (209 male, 249 female, mean age 73.2 ± 9.9 years) with SCD (n = 44), naMCI (n = 40), aMCI (n = 182), AD (n = 120), MD (n = 68) and VD (n = 4) were analyzed. A total of 109 patients (23.8%) were diagnosed with possible or probable CAA. CAA prevalence was highest in aMCI (39.4%) and MD (28.4%). Of patients with possible or probable CAA, 30.3% were under platelet aggregation inhibition, 12.8% were treated with novel oral anticoagulants and 3.7% received phenprocoumon treatment. Regarding the whole study cohort, patients under oral anticoagulation showed more cerebral microbleeds (p = 0.047). There was no relationship between oral anticoagulation therapy and the frequency of cortical superficial siderosis (p = 0.634). CONCLUSION CAA is a frequent phenomenon in older patients with cognitive disorders. Almost half of CAA patients receive anticoagulant therapy. Oral anticoagulation is associated with a higher number of cortical and subcortical microbleeds.
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den Braber B, Hall C, Brandt M, Reiner F, Mugabowindekwe M, Rasmussen LV. Even low levels of tree cover improve dietary quality in West Africa. PNAS NEXUS 2024; 3:pgae067. [PMID: 38404357 PMCID: PMC10890828 DOI: 10.1093/pnasnexus/pgae067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 01/29/2024] [Indexed: 02/27/2024]
Abstract
Forests are attracting attention as a promising avenue to provide nutritious and "free" food without damaging the environment. Yet, we lack knowledge on the extent to which this holds in areas with sparse tree cover, such as in West Africa. This is largely due to the fact that existing methods are poorly designed to quantify tree cover in drylands. In this study, we estimate how various levels of tree cover across West Africa affect children's (aged 12-59 months) consumption of vitamin A-rich foods. We do so by combining detailed tree cover estimates based on PlanetScope imagery (3 m resolution) with Demographic Health Survey data from >15,000 households. We find that the probability of consuming vitamin A-rich foods increases from 0.45 to 0.53 with an increase in tree cover from the median value of 8.8 to 16.8% (which is the tree cover level at which the predicted probability of consuming vitamin A-rich foods is the highest). Moreover, we observe that the effects of tree cover vary across poverty levels and ecoregions. The poor are more likely than the non-poor to consume vitamin A-rich foods at low levels of tree cover in the lowland forest-savanna ecoregions, whereas the difference between poor and non-poor is less pronounced in the Sahel-Sudan. These results highlight the importance of trees and forests in sustainable food system transformation, even in areas with sparse tree cover.
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Cheng Y, Oehmcke S, Brandt M, Rosenthal L, Das A, Vrieling A, Saatchi S, Wagner F, Mugabowindekwe M, Verbruggen W, Beier C, Horion S. Scattered tree death contributes to substantial forest loss in California. Nat Commun 2024; 15:641. [PMID: 38245523 PMCID: PMC10799937 DOI: 10.1038/s41467-024-44991-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 01/11/2024] [Indexed: 01/22/2024] Open
Abstract
In recent years, large-scale tree mortality events linked to global change have occurred around the world. Current forest monitoring methods are crucial for identifying mortality hotspots, but systematic assessments of isolated or scattered dead trees over large areas are needed to reduce uncertainty on the actual extent of tree mortality. Here, we mapped individual dead trees in California using sub-meter resolution aerial photographs from 2020 and deep learning-based dead tree detection. We identified 91.4 million dead trees over 27.8 million hectares of vegetated areas (16.7-24.7% underestimation bias when compared to field data). Among these, a total of 19.5 million dead trees appeared isolated, and 60% of all dead trees occurred in small groups ( ≤ 3 dead trees within a 30 × 30 m grid), which is largely undetected by other state-level monitoring methods. The widespread mortality of individual trees impacts the carbon budget and sequestration capacity of California forests and can be considered a threat to forest health and a fuel source for future wildfires.
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Liu S, Brandt M, Nord-Larsen T, Chave J, Reiner F, Lang N, Tong X, Ciais P, Igel C, Pascual A, Guerra-Hernandez J, Li S, Mugabowindekwe M, Saatchi S, Yue Y, Chen Z, Fensholt R. The overlooked contribution of trees outside forests to tree cover and woody biomass across Europe. SCIENCE ADVANCES 2023; 9:eadh4097. [PMID: 37713489 PMCID: PMC10881069 DOI: 10.1126/sciadv.adh4097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 08/15/2023] [Indexed: 09/17/2023]
Abstract
Trees are an integral part in European landscapes, but only forest resources are systematically assessed by national inventories. The contribution of urban and agricultural trees to national-level carbon stocks remains largely unknown. Here we produced canopy cover, height and above-ground biomass maps from 3-meter resolution nanosatellite imagery across Europe. Our biomass estimates have a systematic bias of 7.6% (overestimation; R = 0.98) compared to national inventories of 30 countries, and our dataset is sufficiently highly resolved spatially to support the inclusion of tree biomass outside forests, which we quantify to 0.8 petagrams. Although this represents only 2% of the total tree biomass, large variations between countries are found (10% for UK) and trees in urban areas contribute substantially to national carbon stocks (8% for the Netherlands). The agreement with national inventory data, the scalability, and spatial details across landscapes, including trees outside forests, make our approach attractive for operational implementation to support national carbon stock inventory schemes.
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Reiner F, Brandt M, Tong X, Skole D, Kariryaa A, Ciais P, Davies A, Hiernaux P, Chave J, Mugabowindekwe M, Igel C, Oehmcke S, Gieseke F, Li S, Liu S, Saatchi S, Boucher P, Singh J, Taugourdeau S, Dendoncker M, Song XP, Mertz O, Tucker CJ, Fensholt R. More than one quarter of Africa's tree cover is found outside areas previously classified as forest. Nat Commun 2023; 14:2258. [PMID: 37130845 PMCID: PMC10154416 DOI: 10.1038/s41467-023-37880-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/29/2023] [Indexed: 05/04/2023] Open
Abstract
The consistent monitoring of trees both inside and outside of forests is key to sustainable land management. Current monitoring systems either ignore trees outside forests or are too expensive to be applied consistently across countries on a repeated basis. Here we use the PlanetScope nanosatellite constellation, which delivers global very high-resolution daily imagery, to map both forest and non-forest tree cover for continental Africa using images from a single year. Our prototype map of 2019 (RMSE = 9.57%, bias = -6.9%). demonstrates that a precise assessment of all tree-based ecosystems is possible at continental scale, and reveals that 29% of tree cover is found outside areas previously classified as tree cover in state-of-the-art maps, such as in croplands and grassland. Such accurate mapping of tree cover down to the level of individual trees and consistent among countries has the potential to redefine land use impacts in non-forest landscapes, move beyond the need for forest definitions, and build the basis for natural climate solutions and tree-related studies.
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Li S, Brandt M, Fensholt R, Kariryaa A, Igel C, Gieseke F, Nord-Larsen T, Oehmcke S, Carlsen AH, Junttila S, Tong X, d’Aspremont A, Ciais P. Deep learning enables image-based tree counting, crown segmentation, and height prediction at national scale. PNAS NEXUS 2023; 2:pgad076. [PMID: 37065619 PMCID: PMC10096914 DOI: 10.1093/pnasnexus/pgad076] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 01/28/2023] [Accepted: 02/27/2023] [Indexed: 04/18/2023]
Abstract
Sustainable tree resource management is the key to mitigating climate warming, fostering a green economy, and protecting valuable habitats. Detailed knowledge about tree resources is a prerequisite for such management but is conventionally based on plot-scale data, which often neglects trees outside forests. Here, we present a deep learning-based framework that provides location, crown area, and height for individual overstory trees from aerial images at country scale. We apply the framework on data covering Denmark and show that large trees (stem diameter >10 cm) can be identified with a low bias (12.5%) and that trees outside forests contribute to 30% of the total tree cover, which is typically unrecognized in national inventories. The bias is high (46.6%) when our results are evaluated against all trees taller than 1.3 m, which involve undetectable small or understory trees. Furthermore, we demonstrate that only marginal effort is needed to transfer our framework to data from Finland, despite markedly dissimilar data sources. Our work lays the foundation for digitalized national databases, where large trees are spatially traceable and manageable.
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Tucker C, Brandt M, Hiernaux P, Kariryaa A, Rasmussen K, Small J, Igel C, Reiner F, Melocik K, Meyer J, Sinno S, Romero E, Glennie E, Fitts Y, Morin A, Pinzon J, McClain D, Morin P, Porter C, Loeffler S, Kergoat L, Issoufou BA, Savadogo P, Wigneron JP, Poulter B, Ciais P, Kaufmann R, Myneni R, Saatchi S, Fensholt R. Sub-continental-scale carbon stocks of individual trees in African drylands. Nature 2023; 615:80-86. [PMID: 36859581 PMCID: PMC9977681 DOI: 10.1038/s41586-022-05653-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/13/2022] [Indexed: 03/03/2023]
Abstract
The distribution of dryland trees and their density, cover, size, mass and carbon content are not well known at sub-continental to continental scales1-14. This information is important for ecological protection, carbon accounting, climate mitigation and restoration efforts of dryland ecosystems15-18. We assessed more than 9.9 billion trees derived from more than 300,000 satellite images, covering semi-arid sub-Saharan Africa north of the Equator. We attributed wood, foliage and root carbon to every tree in the 0-1,000 mm year-1 rainfall zone by coupling field data19, machine learning20-22, satellite data and high-performance computing. Average carbon stocks of individual trees ranged from 0.54 Mg C ha-1 and 63 kg C tree-1 in the arid zone to 3.7 Mg C ha-1 and 98 kg tree-1 in the sub-humid zone. Overall, we estimated the total carbon for our study area to be 0.84 (±19.8%) Pg C. Comparisons with 14 previous TRENDY numerical simulation studies23 for our area found that the density and carbon stocks of scattered trees have been underestimated by three models and overestimated by 11 models, respectively. This benchmarking can help understand the carbon cycle and address concerns about land degradation24-29. We make available a linked database of wood mass, foliage mass, root mass and carbon stock of each tree for scientists, policymakers, dryland-restoration practitioners and farmers, who can use it to estimate farmland tree carbon stocks from tablets or laptops.
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Mugabowindekwe M, Brandt M, Chave J, Reiner F, Skole DL, Kariryaa A, Igel C, Hiernaux P, Ciais P, Mertz O, Tong X, Li S, Rwanyiziri G, Dushimiyimana T, Ndoli A, Uwizeyimana V, Lillesø JPB, Gieseke F, Tucker CJ, Saatchi S, Fensholt R. Nation-wide mapping of tree-level aboveground carbon stocks in Rwanda. NATURE CLIMATE CHANGE 2022; 13:91-97. [PMID: 36684409 PMCID: PMC9845119 DOI: 10.1038/s41558-022-01544-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
Trees sustain livelihoods and mitigate climate change but a predominance of trees outside forests and limited resources make it difficult for many tropical countries to conduct automated nation-wide inventories. Here, we propose an approach to map the carbon stock of each individual overstory tree at the national scale of Rwanda using aerial imagery from 2008 and deep learning. We show that 72% of the mapped trees are located in farmlands and savannas and 17% in plantations, accounting for 48.6% of the national aboveground carbon stocks. Natural forests cover 11% of the total tree count and 51.4% of the national carbon stocks, with an overall carbon stock uncertainty of 16.9%. The mapping of all trees allows partitioning to any landscapes classification and is urgently needed for effective planning and monitoring of restoration activities as well as for optimization of carbon sequestration, biodiversity and economic benefits of trees.
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Zhang XM, Brandt M, Yue YM, Tong XW, Wang KL, Fensholt R. The Carbon Sink Potential of Southern China After Two Decades of Afforestation. EARTH'S FUTURE 2022; 10:e2022EF002674. [PMID: 37035441 PMCID: PMC10078587 DOI: 10.1029/2022ef002674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 10/05/2022] [Accepted: 11/04/2022] [Indexed: 06/19/2023]
Abstract
Afforestation and land use changes that sequester carbon from the atmosphere in the form of woody biomass have turned southern China into one of the largest carbon sinks globally, which contributes to mitigating climate change. However, forest growth saturation and available land that can be forested limit the longevity of this carbon sink, and while a plethora of studies have quantified vegetation changes over the last decades, the remaining carbon sink potential of this area is currently unknown. Here, we train a model with multiple predictors characterizing the heterogeneous landscapes of southern China and predict the biomass carbon carrying capacity of the region for 2002-2017. We compare observed and predicted biomass carbon density and find that during about two decades of afforestation, 2.34 PgC have been sequestered between 2002 and 2017, and a total of 5.32 Pg carbon can potentially still be sequestrated. This means that the region has reached 73% of its aboveground biomass carbon carrying capacity in 2017, which is 12% more than in 2002, equal to a decrease of 0.77% per year. We identify potential afforestation areas that can still sequester 2.39 PgC, while old and new forests have reached 87% of their potential with 1.85 PgC remaining. Our work locates areas where vegetation has not yet reached its full potential but also shows that afforestation is not a long-term solution for climate change mitigation.
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Brandt M, Khraisat S, Doerschmann H, Kalinovic S, Molitor M, Karbach SH, Daiber A, Munzel T, Wenzel P. Telomere shortening in hypertensive heart disease depends on NOX2-mediated loss of PRDX1 and oxidative DNA damage. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Heart failure (HF) coincides with cardiomyocyte telomere shortening. Arterial hypertension is the most prominent risk factor for HF. Both HF and arterial hypertension are associated with dysregulation of the neurohormonal axis and increased ROS. However, how neurohormonal activation is linked to telomere shortening in the pathogenesis of HF is incompletely understood. Further, recent findings suggest that peroxiredoxin 1 (PRDX1) can act as a telomere specific antioxidant.
Methods
To induce hypertensive HF, male C57BL/6J mice were subjected to AngII-infusion, uninephrectomy and high-salt (AngII++) for 5 weeks. Cardiac function was assessed by ultrasound. Mouse adult cardiomocytes (CMs) isolated from C57BL/6J mice and mice lacking the NADPH-oxidase (NOX) 2/gp91phox as well as rat ventricular CM-derived cells (H9C2) were stimulated with AngII. Telomere length was quantified by Q-FISH after staining with a C-rich telomere probe (TelC). DNA/RNA-damage was evaluated after staining for Oxo-8-Gua (8-oxo-7,8-dihydroguanine) and Oxo-8-G (8-oxo-7,8-dihydroguanosine). Superoxide (O2-) was quantified by 2-hydroxyethidium (2-HE) using HPLC analysis. Colocalization of Oxo-8-Gua and TelC was quantified by automated image analysis. (Sub)cellular and tissue expression of gp91phox/Nox2 and PRDX1 was evaluated by ICC/IHC. All image quantification was conducted semiautomatically.
Results
In mice subjected to hypertensive HF, CM telomere shortening correlated significantly with both left ventricular (LV) dilatation and impairment of LV systolic function, paralleled by a significant loss of myocardial PRDX1 and significantly increased myocardial DNA/RNA-damage. Similarly, CMs stimulated with AngII exhibited significant telomere shortening, significant loss of PRDX1 and significantly increased DNA/RNA-damage, together with significantly increased CM superoxide production and significantly increased expression of the superoxide generating enzyme gp91phox/NOX2. Correspondingly, deficiency of gp91phox/NOX2 significantly prevented AngII-induced CM telomere shortening, DNA/RNA-damage and PRDX1-depletion. A similar effect could be observed upon stimulation of CMs with the specific histone deacetylase (HDAC) 6-inhibitor tubastatin, which prevents deacetylation of PRDX1.
Conclusion
We could provide first evidence that in heart failure, ROS originating from increased NOX2-activity leads to depletion of the telomere-targeted antioxidant and repair-protein PRDX1, which results in damage to the telomeric DNA. Both depletion of NOX2 as well as harnessing the intrinsic antioxidant defense by stabilizing PRDX1 via HDAC6-inhibition prevented CM telomere shortening and could be further evaluated as potential therapeutic targets to address heart failure.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Federal Ministry for Education and Research
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Bielfeldt S, Urquhart D, Brandt M, Hennighausen N, Bazzanella R. Reduction of residual topical diclofenac in waste water by a wiping procedure before hand washing. CHEMOSPHERE 2022; 292:133350. [PMID: 34933024 DOI: 10.1016/j.chemosphere.2021.133350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/15/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Diclofenac is non-steroidal anti-inflammatory drug (NSAID) with widespread usage as a topical treatment for relief of pain and inflammation in soft-tissue injuries. While the permeation mechanisms of topically applied diclofenac are well documented, the fate of residual diclofenac not retained at the site of pain following subsequent hand-washing is still not well characterized. The aim of this study quantifies the amount of diclofenac present in rinse water after the application of a topical pain gel containing 23.2 mg/g diclofenac diethylamine, and subsequent washing of the hands. A comparison of two different hand washing techniques was completed with and without wiping hands directly after product application and before washing. A pilot study was completed to optimize the analytical procedures used in the quantification of diclofenac in the rinse water, followed by a main study with 24 test subjects. The data were first analyzed separately and subsequently pooled for statistical analysis. To determine the amount of diclofenac in the rinse water samples, we used reverse phase-liquid chromatography-mass spectrometry (RP-LC-MS/MS). It was determined that a hand washing procedure with a pre-wash wipe of the hands with a paper towel resulted in a 66% reduction in diclofenac released into the waste water system (7.43 ± 3.02 mg/L). This study shows for the first time that a wiping procedure before hand washing will have a significant impact on the amount of diclofenac in the rinse water. Thus, it is possible to significantly impact the release of non-absorbed residual diclofenac after product application.
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Wei F, Wang S, Fu B, Brandt M, Pan N, Wang C, Fensholt R. Response to concerns about the African fire trends controlled by precipitation over recent decades. GLOBAL CHANGE BIOLOGY 2022; 28:e4-e6. [PMID: 34856040 DOI: 10.1111/gcb.16020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/17/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Croplands expanded in Africa over recent decades, even though the increasing trends are spatially heterogeneous.
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Fang Z, Brandt M, Wang L, Fensholt R. A global increase in tree cover extends the growing season length as observed from satellite records. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151205. [PMID: 34710418 DOI: 10.1016/j.scitotenv.2021.151205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Plant phenology provides information on the seasonal dynamics of plants, and changes herein are important for understanding the impact of climate change and human management on the biosphere. Land surface phenology is the study of plant phenology across large spatial scales estimated by satellite observations. However, satellite observations (pixels) are often composed of a mixture of vegetation types, like woody vegetation and herbaceous vegetation, having different phenological characteristics. Therefore, any changes in tree cover presumably impact land surface phenology, as trees usually have a different seasonal cycle compared to herbaceous vegetation. On the other hand, changes in land surface phenology are often interpreted as a result of climate change-induced impacts on the photosynthetic activity of vegetation. Therefore, it is important to better understand the role of changes in vegetation cover (here, the proportion between tree and short vegetation cover) in satellite-derived land surface phenology analysis. We studied the impact of changes in tree cover on satellite observed land surface phenology at a global scale over the past three decades. We found an extension of the growing season length in 36.6% of the areas where tree cover increased, whereas only 20.1% of the areas where tree cover decreased showed an increase in growing season length. Furthermore, the ratio between tree cover and short vegetation cover was found to affect changes in the length of the growing season, with the denser tree cover showing a more pronounced extension of the growing season length (especially in boreal forests). These results highlight the importance of changes in tree cover when analyzing the impact of climate change on vegetation phenology. Our study thereby addresses a critical knowledge gap for an improved understanding of changes in land surface phenology during recent decades in the context of climate and human-induced global land cover change.
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Goebel S, Schwuchow-Thonke S, Hahad O, Brandt M, Von Henning U, Escher F, Karbach S, Braun A, Gori T, Schultheiss H, Muenzel T, Wenzel P. Prevalence and outcome of cardiac amyloidosis in an all-comer population of patients with non-ischaemic heart failure. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.0846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Cardiac amyloidosis (CA) is increasingly recognized as an underlying cause of heart failure with preserved ejection fraction (HFpEF), associated with high morbidity and mortality. However, most studies, solely investigated the prevalence of CA in special subgroups including HFpEF and severe aortic valve disease.
Purpose
With the present study we sought to investigate prevalence of different phenotypes of CA in an all comer-population of patients with non-ischaemic heart failure (HF) and to analyze the impact of CA on all-cause mortality.
Methods
The My Biopsy HF-Study (German clinical trials register number: 22178) is a retrospective monocentric study investigating the underlying etiology of HF in an all-comer population of patients with HF of unknown etiology. Patients presenting with symptoms of HF at the University Medical Centre between 14/10/2012 and 01/03/2021, who underwent endomyocardial biopsy (EMB) were enrolled in the present study. Ischaemic HF and valvular HF were ruled out prior to EMB. Specimens were sent for further examination to a specialized laboratory approved by the Food and Drug Administration
Results
Between October 2012 and March 2021, 767 patients (71.6% men) with HF of unknown etiology were included. Mean age at the time of presentation was 55.4 years (±14.4). Altogether, 72.5% of the patients presented with HF with reduced ejection fraction (HFrEF), 7.1% were diagnosed with HF with mid-range ejection fraction (HFmrEF) and 20.4% with HFpEF. Based on histological examination and genotyping, CA was diagnosed in 44 (5.7%) patients (immunglobulin light chain [AL] CA: 15 patients; variant transthyretin [ATTRv] CA: 6 patients; wild type transthyretin [ATTRwt] CA: 21 patients; de novo CA: 2 patients). Patients with CA were older compared with patients without CA (69.4±11.4 vs. 54.1±14.5; p<0.0001), had a higher prevalence of arterial hypertension (68.2% vs. 50.9%; p=0.045) and showed a better left ventricular ejection fraction based on echocardiographic examination (47.5% vs. 32.6%; p<0.0001). With respect to biomarker expression, levels of both brain natriuretic peptide and high-sensitive troponin I were significantly higher in patients without CA (BNP: 914.1 vs 612; p=0.01; troponin I: 812.8 vs. 171.7; p=0.006). In univariate logistic regression analysis CA was associated with a significant all-cause mortality (hazard ratio [HR] per unit increase [ui], 5.17, 95% CI, 2.93–9.08; p<0.0001), even after adjustment for classical cardiovascular risk factors (HRperui 3.12, 95% CI, 1.11–8.76; p=0.03) and comorbidities like chronic obstructive pulmonary disease, chronic kidney disease and stroke (HRperui 2.93, 95% CI, 1.2–7.15; p=0.018).
Conclusions
Among patients presenting with HF of unknown etiology, including patients with HFpEF, HFmrEF and HFrEF, cardiac amyloidosis is the underlying cause of HF in 5.7% of patients and is independently associated with all-cause mortality.
Funding Acknowledgement
Type of funding sources: None.
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Brandt M, Doerschmann H, Kalinovic S, Daiber A, Muenzel T, Wenzel P. Telomere shortening in heart failure due to excess neurohormonal activation is associated with loss of nuclear TRF-2 and increased telomeric DNA damage and predicts cardiac recovery. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.0723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
The mechanisms and clinical significance of telomere shortening in heart failure remain elusive. Mammalian cardiomyocyte (CM) regeneration is limited and CM cell division cannot account for telomere shortening. Whether telomere shortening in turn affects cardiac recovery remains unexplored.
We induced heart failure by excess neurohormonal activation (NHA), a universal dysregulation in the failing heart.
B6 mice were subjected to AngII-infusion, uninephrectomy and high-salt (AngII++) to induce excess NHA for 5 weeks. Cardiac function was assessed by ultrasound. Human iPSC-derived CMs, mouse CMs and rat ventricular CMs (H9C2) were stimulated with AngII. Human cardiac biopsies from patients with heart failure with reduced ejection fraction (HFrEF) were grouped depending on cardiac recovery. Telomere length was quantified by Q-FISH. ROS-induced DNA/RNA-damage was evaluated after staining for 8-oxo-7,8-dihydro-2'-deoxyguanosine, -guanine and – guanosine-residues (8-oxo-dG). H9C2-cells were co-stained for telomeres, telomere repeat binding factor 2 (TRF-2) and 8-oxo-dG, telomere-specific DNA-damage was quantified by automated colocalization analysis. Superoxide (O2-) was quantified by 2-hydroxyethidium (2-HE) using HPLC analysis. Fibrosis was quantified by Sirius red staining.
AngII++-mice exhibited left ventricular (LV) hypertrophy (p<0.0001 vs B6) along with reduced LV ejection fraction (p=0.03 vs B6), reduced global longitudinal strain (p<0.001 vs B6) along with significant telomere shortening in CMs isolated from AngII++-mice (p=0.0082 vs B6). Telomere length showed a significant correlation with LV systolic function (r2=0.64, p=0.006). While 8-oxo-dG-staining revealed significantly increased ROS-induced DNA/RNA damage in AngII++-myocardial sections overall (p<0.0001 vs B6), DNA/RNA-damage was highest in areas of fibrotic adverse remodeling congruent with significant telomere shortening (p<0.0122 fibrotic vs non-fibrotic AngII++-myocardium, p<0.0001 vs B6). In all cells tested, NHA resulted in significant telomere shortening. As a potential explanation, CMs stimulated with AngII revealed significantly increased, dose-dependent O2–production (AngII 10 nM p=0.03, AngII 50 nm p=0.0004 vs H9C2) along with significant loss of nucelar TRF2 (AngII nM p=0.0049, Ang II 50 nM p<0.0001 vs H9C2), while colocalization analysis revealed a significantly increased ROS-induced damage to the telomeric DNA (AngII 10/50 nm p<0.05 vs H9C2).
HFrEF-patients that had recovered cardiac function (ΔLVEF +5 – 30%) showed significantly longer myocardial telomeres than patients with no recovery/worsening (ΔLVEF −10 – 0%) (p=0.008), overall the telomere signal correlated significantly with ΔLVEF (r2=0.41, p=0.03).
Our data provides insides into how excess NHA via increased ROS, loss of nuclear TRF-2 and increased telomeric DNA-damage causes myocardial telomere shortening in heart failure and further that the extent of telomere shortening determines cardiac recovery.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): BMBF 01EO1003
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Vega AG, Mazaira MR, Fernandez NM, Nuñez MI, Brandt M, Juan LV, Vargas PP, Rodriguez ZG, Bermudez SC, Seivane RGA, Abbad RSDLC. O-199 Proof of concept: implantation window must be wider than proposed. Report of seven twins after asynchronous double embryo transfer. Hum Reprod 2021. [DOI: 10.1093/humrep/deab128.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Study question
Can simultaneous transfer of two embryos that were cryopreserved at different stages (D3 and Blastocyst) be appropriate to enhance success in women with more than three failed embryo transfers?
Summary answer
Double asynchronous embryo transfer offered excellent results in RIF. Unexpectedly high twin rate suggests that embryo-endometrium synchrony is overemphasized. Implantation window must be wider.
What is known already
Transcriptomic signature of the endometrium has been investigated in the last few years trying to understand the best moment for embryo implantation. Nevertheless, the optimal period has not been well established yet in humans. Simultaneous transfer of two human embryos at different developmental stages (D3 and Blastocyst) on Day 4 was proposed to help couples who have had RIF.
Study design, size, duration
Observational case-control study. From April 2016 to January 2021, we offered double asynchronous embryo transfer only after Recurrent Implantation Failure (RIF). Two requirements were necessary: 1) Double embryo transfer was acceptable by the couple due to poor reproductive outcome. 2) Availability of two embryos cryopreserved at different stage (D3 and Blastocyst). Results were compared with good prognosis patients (all patients under 35 years in that period who had elected to transfer two day 3 cryopreserved embryos).
Participants/materials, setting, methods
Forty-five patients accepted to participate in the study. Results were compared with all patients (237) under 35 years where two D3 thawed embryos were transferred. All cases received same protocol (oral estradiol 6mg/d or vaginal estradiol 4mg/d until ultrasound showed endometrial growth) LH, P4 and E2 were monitored in all patients to detect spontaneous LH surge. All cases received transvaginal micronized progesterone 800 mg/d. Embryo transfers were ultrasound guided and Wallace Embryosure catheter was employed.
Main results and the role of chance
Limitations, reasons for caution
Multiple pregnancy rate was unacceptably high. Therefore, it should not be suggested for good prognosis couples where single embryo transfer is clearly advidsed. Our main limitation was the combination of D3 embryos with blastocysts. The retrospective design make the results to be considered as a proof of concept.
Wider implications of the findings
Double asynchronic embryo transfer can offer new insights in the understanding of human implantation. The concept of implantation window is clearly challenged. Aiming to the center of the window is fine, but we still dońt know how wide is that center.
Trial registration number
not applicable
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Zhang X, Yue Y, Tong X, Wang K, Qi X, Deng C, Brandt M. Eco-engineering controls vegetation trends in southwest China karst. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 770:145160. [PMID: 33736419 DOI: 10.1016/j.scitotenv.2021.145160] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
The karst area in Yunnan-Guangxi-Guizhou region in southwest China is known for widespread rocky desertification but several studies report a greening trend since the year 2000. While the start of the greening trend seems to match with the implementation of ecological conservation projects, no statistical evidence on a relationship between vegetation greening and eco-engineering exists. Moreover, dominant factors influencing the spatial patterns of vegetation trends have rarely been investigated. Here we use six comprehensive factors representing the natural conditions and human activities of the study area, and several statistical models consistently show that eco-engineering explains large parts of the positive vegetation trends in the karst areas, while negative vegetation trends in non-karst areas of Yunnan were related with a decrease in rainfall. We further show that the interaction of eco-engineering with other factors leads to a heterogeneous pattern of different vegetation trends. Knowing and understanding these patterns is crucial when planning ecological restoration, especially in diverse landscapes like China karst and the methods can be reused in other restoration areas.
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Stettler H, Crowther JM, Brandt M, Boxshall A, Lu B, de Salvo R, Laing S, Hennighausen N, Bielfeldt S, Blenkiron P. Multi parametric biophysical assessment of treatment effects on xerotic skin. SKIN HEALTH AND DISEASE 2021; 1:e21. [PMID: 35664981 PMCID: PMC9060006 DOI: 10.1002/ski2.21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Abstract
Background Topical moisturizing products are widely used to alleviate the problems associated with xerotic skin. Their use affects many properties of the stratum corneum (SC) in a complex and interrelated manner. The range of measurement techniques available to the researcher has increased in recent years. However, few studies have looked for correlations between the different techniques for assessing how aspects of xerotic skin change over time as a result of topical moisturizer usage. Objectives A 3‐week in vivo study using an oil‐in‐water based moisturizing product and an untreated site was conducted to determine the clinical significance of and any correlations between a range of different approaches for the measurement of skin lipid content and also skin hydration and visual grading of dry skin. Methods A range of traditional and more recently developed skin measurement techniques have been used to examine a variety of SC properties in normal and xerotic skin during topical moisturizer usage. Results In vivo confocal Raman spectroscopy and analysis of SC lipids from tape strips both showed an increase in SC lipid level and organization after 3 weeks of moisturizer usage on xerotic skin. Hydration, measured both optically and electrically, also increased and skin barrier function improved, with strong correlations between the different measures of dryness being observed. Conclusions Strong correlations were observed between the skin measurements for lipid assessment and skin hydration with regard to the assessment of xerotic skin, providing valuable new information for future in vivo clinical research into dry and atopic skin. Keywords biophysical assessment, skin barrier, skin hydration, topical moisturizers, Xerosis
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