Perceptual Quality Assessment of NeRF and Neural View Synthesis Methods for Front-Facing Views

Neural view synthesis (NVS) is one of the most successful techniques for synthesizing free viewpoint videos, capable of achieving high fidelity from only a sparse set of captured images. This success has led to many variants of the techniques, each evaluated on a set of test views typically using image quality metrics such as PSNR, SSIM, or LPIPS. There has been a lack of research on how NVS methods perform with respect to perceived video quality. We present the first study on perceptual evaluation of NVS and NeRF variants. For this study, we collected two datasets of scenes captured in a controlled lab environment as well as in-the-wild. In contrast to existing datasets, these scenes come with reference video sequences, allowing us to test for temporal artifacts and subtle distortions that are easily overlooked when viewing only static images. We measured the quality of videos synthesized by several NVS methods in a well-controlled perceptual quality assessment experiment as well as with many existing state-of-the-art image/video quality metrics. We present a detailed analysis of the results and recommendations for dataset and metric selection for NVS evaluation

A 382-year reconstruction of August mean minimum temperature from tree-ring maximum latewood density on the southeastern Tibetan Plateau, China

Long-term summer temperature records are important for climate studies on the Tibetan Plateau (TP). Here, we used tree-ring maximum latewood density (MXD) to develop a well-replicated regional chronology back to the year 1630 for the southeastern TP. The MXD chronology is positively related to the observed August mean minimum temperatures (AMMT) in the period 1961-2011. Therefore, the AMMT was reconstructed from the MXD chronology. The reconstruction explained 42.6% of the total variance in the observed AMMT. During the past 382 years, warm periods were found during 1646-1694,1770-1805, 1930-1971 and 1992-2011, and cold periods were found during 1630-1645, 1695-1749, 1806-1825, 1889-1929 and 1972-1991. Extreme cold summers (= mean+2 SD) occurred in the years 1786, 1788, 2003, 2004 and 2005. A comparison with temperature records in surrounding regions showed general agreements, indicating the fidelity of our reconstruction and its ability to represent summer temperature variations over a broad geographic extent. Conspicuous in-phase relationships between our reconstruction and the Atlantic Multidecadal Oscillation (AMO) indicated a strongly positive association between large-scale climate circulations and summer temperature variability on the southeastern TP at multidecadal scales. (C) 2015 Elsevier GmbH. All rights reserved

A 382-year reconstruction of August mean minimum temperature from tree-ring maximum latewood density on the southeastern Tibetan Plateau, China

Long-term summer temperature records are important for climate studies on the Tibetan Plateau (TP). Here, we used tree-ring maximum latewood density (MXD) to develop a well-replicated regional chronology back to the year 1630 for the southeastern TP. The MXD chronology is positively related to the observed August mean minimum temperatures (AMMT) in the period 1961-2011. Therefore, the AMMT was reconstructed from the MXD chronology. The reconstruction explained 42.6% of the total variance in the observed AMMT. During the past 382 years, warm periods were found during 1646-1694,1770-1805, 1930-1971 and 1992-2011, and cold periods were found during 1630-1645, 1695-1749, 1806-1825, 1889-1929 and 1972-1991. Extreme cold summers (= mean+2 SD) occurred in the years 1786, 1788, 2003, 2004 and 2005. A comparison with temperature records in surrounding regions showed general agreements, indicating the fidelity of our reconstruction and its ability to represent summer temperature variations over a broad geographic extent. Conspicuous in-phase relationships between our reconstruction and the Atlantic Multidecadal Oscillation (AMO) indicated a strongly positive association between large-scale climate circulations and summer temperature variability on the southeastern TP at multidecadal scales. (C) 2015 Elsevier GmbH. All rights reserved

High glucose dialysate-induced peritoneal fibrosis: Pathophysiology, underlying mechanisms and potential therapeutic strategies

Peritoneal dialysis is an efficient renal replacement therapy for patients with end-stage kidney disease. However, continuous exposure of the peritoneal membrane to dialysate frequently leads to peritoneal fibrosis, which alters the function of the peritoneal membrane and results in withdrawal from peritoneal dialysis in patients. Among others, high glucose dialysate is considered as a predisposing factor for peritoneal fibrosis in patients on peritoneal dialysis. Glucose-induced inflammation, metabolism disturbance, activation of the renin–angiotensin–aldosterone system, angiogenesis and noninflammation-induced reactive oxygen species are implicated in the pathogenesis of high glucose dialysate-induced peritoneal fibrosis. Specifically, high glucose causes chronic inflammation and recurrent peritonitis, which could cause migration and polarization of inflammatory cells, as well as release of cytokines and fibrosis. High glucose also interferes with lipid metabolism and glycolysis by activating the sterol-regulatory element-binding protein-2/cleavage-activating protein pathway and increasing hypoxia inducible factor-1α expression, leading to angiogenesis and peritoneal fibrosis. Activation of the renin–angiotensin-aldosterone system and Ras-mitogen activated protein kinase signaling pathway is another contributing factor in high glucose dialysate-induced fibrosis. Ultimately, activation of the transforming growth factor-β1/Smad pathway is involved in mesothelial-mesenchymal transition or epithelial-mesenchymal transition, which leads to the development of fibrosis. Although possible intervention strategies for peritoneal dialysate-induced fibrosis by targeting the transforming growth factor-β1/Smad pathway have occasionally been proposed, lack of laboratory evidence renders clinical decision-making difficult. We therefore aim to revisit the upstream pathways of transforming growth factor-beta1/Smad and propose potential therapeutic targets for high glucose-induced peritoneal fibrosis

An updated meta-analysis on the efficacy and safety of hypoxia-inducible factor prolyl hydroxylase inhibitor treatment of anemia in nondialysis-dependent chronic kidney disease

AbstractBackground Renal anemia, a common complication and threat factor of chronic kidney disease (CKD), has long been treated with injectable erythropoietin-stimulating agents (ESAs). As concerns regarding cardiovascular safety and erythropoietin resistance to ESAs have emerged, alternative therapies are urgently needed. Hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), an oral agent, has been proven to be effective in improving renal anemia. However, the effects of HIF-PHIs on nondialysis-dependent CKD (NDD-CKD) have yet to be supported by updated meta-analyses.Methods A meta-analysis of clinical randomized controlled trials (RCTs) on HIF-PHI treatment of NDD-CKD patients based on PubMed, EMBASE, and Cochrane databases as of July 16th, 2023, was conducted. The primary outcomes were the level of hemoglobin (Hb) postintervention and the ratio of Hb responses. Most of the analysis was conducted via RevMan 5.3 software using a random-effects model. Stata (version 15.0) was used to analyze the publication bias.Results Twenty-two studies with a total of 7178 subjects in the HIF-PHI group, 3501 subjects in the ESA group and 2533 subjects in the placebo group were enrolled. HIF-PHIs increased the level of Hb and improved iron metabolism but were not inferior to ESAs in terms of safety.Conclusions HIF-PHIs may be a convenient and safe alternative to ESAs in patients with NDD-CKD and anemia

Topographic patterns of forest decline as detected from tree rings and NDVI

Forest decline is mostly attributed to factors related to climate change and human activities. However, it is not well-known how topographic factors indirectly shape the forest decline. In this study, we analyzed the topographic patterns of growth decline in Pinus densiflora forests in the Mengshan Mountains of eastern China. A forest decline event occurring in 2009-2014 was identified using the Normalized Difference Vegetation Index (NDVI) and tree-ring widths. A decision tree model was developed to extract the topographic pattern of the forest decline. Boosted regression tree model indicates that the relative influence of elevation is 93.6%, and the remaining relative influence includes aspect, slope, and landform. We conclude that topography, elevation in particular, indirectly shapes the vulnerability of sites to forest decline and can thus be used to predict the spatial decline risks. Our findings provide new insights into the role of topography in forest decline and hold implications for predicting decline risk and protecting forests in a rapidly changing world

Self-Calibrated Multi-Sensor Wearable for Hand Tracking and Modeling

We present a multi-sensor system for consistent 3D hand pose tracking and modeling that leverages the advantages of both wearable and optical sensors. Specifically, we employ a stretch-sensing soft glove and three IMUs in combination with an RGB-D camera. Different sensor modalities are fused based on the availability and confidence estimation, enabling seamless hand tracking in challenging environments with partial or even complete occlusion. To maximize the accuracy while maintaining high ease-of-use, we propose an automated user calibration that uses the RGB-D camera data to refine both the glove mapping model and the multi-IMU system parameters. Extensive experiments show that our setup outperforms the wearable-only approaches when the hand is in the field-of-view and outplays the camera-only methods when the hand is occluded.ISSN:1077-2626ISSN:1941-0506ISSN:2160-930

Innovative nanoporous carbons with ultrahigh uptakes for capture and reversible storage of CO2 and volatile iodine

Porous carbons as solid-state adsorbents have recently attracted considerable interest in the areas of storage and capture of CO2 as well as the adsorption of radioactive matters. In this work, cigarette butts, one kind of common wastes referring to the filters, were utilized to prepare highly porous carbons by KOH activation in argon atmosphere. The resulting porous carbon shows a high specific surface area of up to 2751 m(2) g(-1) with abundant micropores. The resulting porous carbon exhibits excellent iodine uptake of 262 wt% and high CO2 adsorption capacity of 6.0 mmol g(-1) at ambient pressure and 273 K, which both are among the highest values reported to date. Given these excellent iodine uptake, CO2 adsorption capacity, ease of preparation as well as good physiochemical stability, the porous carbons derived from cigarette butts show great potential in the reversible adsorption of radioactive iodine and CO2. (C) 2016 Elsevier B.V. All rights reserved