| 1. |
- Björkstrand, David, 1991-, et al.
(author)
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Cross-attention Masked Auto-Encoder for Human 3D Motion Infilling and Denoising
- 2023
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Conference paper (peer-reviewed)abstract
- Human 3D pose and motion capture have numerous applications in fields such as augmented and virtual reality, animation, robotics and sports. However, even the best capturing methods suffer from artifacts such as missed joints and noisy or inaccurate joint positions. To address this we propose the Cross-attention Masked Auto-Encoder (XMAE) for human 3D motion infilling and denoising. XMAE extends the original Masked Auto-Encoder design by introducing cross-attention in the decoder to deal with the train-test gap common in methods utilizing masking and mask tokens. Furthermore, we introduce joint displacement as an additional noise source during training, enabling XMAE to learn to correct incorrect joint positions. Through extensive experiments, we show XMAE's effectiveness compared to state-of-the-art approaches across three public datasets and its ability to denoise real-world data, reducing limb length standard deviation by 28\% when applied on our in-the-wild professional soccer dataset.
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| 2. |
- Emerson, Joanne B., et al.
(author)
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Host-linked soil viral ecology along a permafrost thaw gradient
- 2018
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In: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 3:8, s. 870-880
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Journal article (peer-reviewed)abstract
- Climate change threatens to release abundant carbon that is sequestered at high latitudes, but the constraints on microbial metabolisms that mediate the release of methane and carbon dioxide are poorly understood(1-7). The role of viruses, which are known to affect microbial dynamics, metabolism and biogeochemistry in the oceans(8-10), remains largely unexplored in soil. Here, we aimed to investigate how viruses influence microbial ecology and carbon metabolism in peatland soils along a permafrost thaw gradient in Sweden. We recovered 1,907 viral populations (genomes and large genome fragments) from 197 bulk soil and size-fractionated metagenomes, 58% of which were detected in metatranscriptomes and presumed to be active. In silico predictions linked 35% of the viruses to microbial host populations, highlighting likely viral predators of key carbon-cycling microorganisms, including methanogens and methanotrophs. Lineage-specific virus/host ratios varied, suggesting that viral infection dynamics may differentially impact microbial responses to a changing climate. Virus-encoded glycoside hydrolases, including an endomannanase with confirmed functional activity, indicated that viruses influence complex carbon degradation and that viral abundances were significant predictors of methane dynamics. These findings suggest that viruses may impact ecosystem function in climate-critical, terrestrial habitats and identify multiple potential viral contributions to soil carbon cycling.
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| 3. |
- Loy, Gareth, et al.
(author)
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Monocular 3D reconstruction of human motion in long action sequences
- 2004
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In: COMPUTER VISION. - BERLIN : SPRINGER. - 3540219811 ; , s. 442-455
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Conference paper (peer-reviewed)abstract
- A novel algorithm is presented for the 3D reconstruction of human action in long (> 30 second) monocular image sequences. A sequence is represented by a small set of automatically found representative keyframes. The skeletal joint positions are manually located in each keyframe and mapped to all other frames in the sequence. For each keyframe a 3D key pose is created, and interpolation between these 3D body poses, together with the incorporation of limb length and symmetry constraints, provides a smooth initial approximation of the 3D motion. This is then fitted to the image data to generate a realistic 3D reconstruction. The degree of manual input required is controlled by the diversity of the sequence's content. Sports' footage is ideally suited to this approach as it frequently contains a limited number of repeated actions. Our method is demonstrated on a long (36 second) sequence of a woman playing tennis filmed with a non-stationary camera. This sequence required manual initialisation on < 1.5% of the frames, and demonstrates that the system can deal with very rapid motion, severe self-occlusions, motion blur and clutter occurring over several concurrent frames. The monocular 3D reconstruction is verified by synthesising a view from the perspective of a 'ground truth' reference camera, and the result is seen to provide a qualitatively accurate 3D reconstruction of the motion.
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| 4. |
- Myers-Smith, Isla H., et al.
(author)
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Complexity revealed in the greening of the Arctic
- 2020
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In: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 10:2, s. 106-117
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Journal article (peer-reviewed)abstract
- As the Arctic warms, vegetation is responding, and satellite measures indicate widespread greening at high latitudes. This ‘greening of the Arctic’ is among the world’s most important large-scale ecological responses to global climate change. However, a consensus is emerging that the underlying causes and future dynamics of so-called Arctic greening and browning trends are more complex, variable and inherently scale-dependent than previously thought. Here we summarize the complexities of observing and interpreting high-latitude greening to identify priorities for future research. Incorporating satellite and proximal remote sensing with in-situ data, while accounting for uncertainties and scale issues, will advance the study of past, present and future Arctic vegetation change.
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| 5. |
- Sullivan, Nathaniel A.T., et al.
(author)
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Differences in analysis and treatment of upper airway obstruction in Robin sequence across different countries in Europe
- 2023
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In: European Journal of Pediatrics. - : Springer Verlag. - 0340-6199 .- 1432-1076. ; 182:3, s. 1271-1280
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Journal article (peer-reviewed)abstract
- The goal of this study was to explore the availability of diagnostic and treatment options for managing upper airway obstruction (UAO) in infants with Robin Sequence (RS) in Europe. Countries were divided in lower- (LHECs, i.e., PPP per capita < $4000) and higher-health expenditure countries (HHECs, i.e., PPP per capita ≥ $4000). An online survey was sent to European healthcare professionals who treat RS. The survey was designed to determine the availability of diagnostic tools such as arterial blood gas analysis (ABG), pulse oximetry, CO2 analysis, polysomnography (PSG), and sleep questionnaires, as well as to identify the used treatment options in a specific center. Responses were received from professionals of 85 centers, originating from 31 different countries. It was equally challenging to provide care for infants with RS in both LHECs and HHECs (3.67/10 versus 2.65/10, p = 0.45). Furthermore, in the LHECs, there was less access to ABG (85% versus 98%, p = 0.03), CO2 analysis (45% versus 70%, p = 0.03), and PSG (54% versus 93%, p < 0.01). There were no significant differences in the accessibility concerning pulse oximetry, sleep questionnaires, home saturation monitoring, nasopharyngeal tubes, Tuebingen plates, and mandibular distraction. Conclusion: This study demonstrates a large difference in available care for infants with RS throughout Europe. LHECs have less access to diagnostic tools in RS when compared to HHECs. There is, however, no difference in the availability of treatment modalities between LHECs and HHECs.What is Known:• Patients with Robin sequence (RS) require complex and multidisciplinary care. They can present with moderate to severe upper airway obstruction (UAO). There exists a large variety in the use of diagnostics for both UAO treatmentindications and evaluations. In most cases, conservative management of UAO in RS is sufficient. Patients with UAO that persist despite conservative management ultimately need surgical intervention. To determine which intervention is best suitable for theindividual RS patient, the level of UAO needs to be determined through diagnostic testing.• There is a substantial variation among institutions across Europe for both diagnostics and treatment options in UAO. A standardized, internationally accepted protocol for the assessment and management of UAO in RS could guide healthcare professionals in the timing of assessment and indications to prevent escalation of UAO. Creating such a protocol might be a challenge, as there are large financial differences between countries in Europe (e.g., health expenditure per capita in purchasing power parity in international dollars ranges from $600 to over $8500).What is New:• There is a substantial variation in the availability of objective diagnostic tools between European countries. Arterial blood gas analysis, CO2 analysis and polysomnography are not equally accessible for lower-healthcare expenditure countries (LHECs) compared to higher-healthcare expenditure countries (HHECs). These differences are not only limited to availability; there is also a difference in quality of these diagnostic tools. Surprisingly, there is no difference in access to treatment tools between LHECs and HHECs.• There is national heterogeneity in access to tools for diagnosis and treatment of RS, which suggests centralization of health care, showing that specialized care is only available in tertiary centers. By centralization of care for RS infants, diagnostics and treatment can be optimized in the best possible way to create a uniform European protocol and ultimately equal care across Europe. Learning what is necessary for adequate monitoring could lead to better allocation of resources, which is especially important in a low-resource setting.
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| 6. |
- Thomas, Enlli, et al.
(author)
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Working towards diagnosing bilingual children's language abilities : issues for teachers in Wales
- 2022
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In: Cylchgrawn Addysg Cymru / Wales Journal of Education. - : University of Wales Press. - 2059-3708 .- 2059-3716. ; 24:2, s. 50-73
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Journal article (peer-reviewed)abstract
- One area of concern within a bilingual context relates to the appropriate‘diagnostic’ assessment of bilingual children’s language abilities and to thesuitable application of their assessment results in practice. Communicationand language difficulties are numerous and complex, and manifest themselvesin a variety of ways that are captured to different degrees via standardisedtests. Such tools are readily available – often in multiple forms – in somelanguages, such as English, but less readily available in others. This is particu-larly the case for minority languages such as Welsh, and this poses greatdifficulty when aiming for a certain type of assessment of specific languageabilities. This paper outlines the current state of diagnostic assessment toolsfor Welsh, with a specific focus on measures of literacy abilities. Drawing onresearch evidence from the Welsh context, we argue for appropriate trainingof educators in this area, and for the urgent need to develop tools that are bothlanguage and context specific, with relevant bilingual speaker norms, thathave practical applications in the classroom, to ensure equitable and relevantdiagnosis and support for all children educated in Wales.
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| 7. |
- Xu, Maojia, et al.
(author)
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Chondrocytes Derived From Mesenchymal Stromal Cells and Induced Pluripotent Cells of Patients With Familial Osteochondritis Dissecans Exhibit an Endoplasmic Reticulum Stress Response and Defective Matrix Assembly
- 2016
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In: Stem Cells Translational Medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 5:9, s. 1171-1181
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Journal article (peer-reviewed)abstract
- Familial osteochondritis dissecans (FOCD) is an inherited skeletal defect characterized by the development of large cartilage lesions in multiple joints, short stature, and early onset of severe osteoarthritis. It is associated with a heterozygous mutation in the ACAN gene, resulting in a Val-Met replacement in the C-type lectin domain of aggrecan. To understand the cellular pathogenesis of this condition, we studied the chondrogenic differentiation of patient bone marrow mesenchymal stromal cells (BM-MSCs). We also looked at cartilage derived from induced pluripotent stem cells (iPSCs) generated from patient fibroblasts. Our results revealed several characteristics of the differentiated chondrocytes that help to explain the disease phenotype and susceptibility to cartilage injury. First, patient chondrogenic pellets had poor structural integrity but were rich in glycosaminoglycan. Second, it was evident that large amounts of aggrecan accumulated within the endoplasmic reticulum of chondrocytes differentiated from both BM-MSCs and iPSCs. In turn, there was a marked absence of aggrecan in the extracellular matrix. Third, it was evident that matrix synthesis and assembly were globally dysregulated. These results highlight some of the abnormal aspects of chondrogenesis in these patient cells and help to explain the underlying cellular pathology. The results suggest that FOCD is a chondrocyte aggrecanosis with associated matrix dysregulation. The work provides a new in vitro model of osteoarthritis and cartilage degeneration based on the use of iPSCs and highlights how insights into disease phenotype and pathogenesis can be uncovered by studying differentiation of patient stem cells.
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