86 research outputs found
On the Structure of the Lower Troposphere in the Summertime Stratocumulus Regime of the Northeast Pacific
Data collected in situ as part of the second field study of the Dynamics and Chemistry of Marine Stratocumulus field program are used to evaluate the state of the atmosphere in the region of field operations near 30°N, 120°W during July 2001, as well as its representation by a variety of routinely available data. The routine data include both the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and NCEP–NCAR reanalyses, forecasts from their respective forecast systems (the Integrated and Global Forecast Systems), the 30-km archive from the International Satellite Cloud Climatology Project (ISCCP), the Quick Scatterometer surface winds, and remotely sensed fields derived from radiances measured by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), the Advanced Microwave Sounding Unit, and the Advanced Very High Resolution Radiometer. The analysis shows that outside of the boundary layer the state of the lower troposphere is reasonably represented by the reanalysis and forecast products, with the caveat of a slight warm bias at 850 hPa in the NCEP–NCAR products. Within the planetary boundary layer (PBL) the agreement is not as good: both the boundary layer depth and cloud amount are underpredicted, and the boundary layer temperature correlates poorly with the available data, which may be related to a poor representation of SSTs in this region of persistent cloud cover. ERA-40 also suffers from persistently weak zonal winds within the PBL. Among the satellite records the ISCCP data are found to be especially valuable, evincing skill in both predicting boundary layer depth (from cloud-top temperatures and TMI surface temperatures) and cloud liquid water paths (from cloud optical depths). An analysis of interannual variability (among Julys) based on ERA-40 and the 1983–2001 ISCCP record suggests that thermodynamic quantities show similar interannual and synoptic variability, principally concentrated just above the PBL, while dynamic quantities vary much more on synoptic time scales. Furthermore, the analysis suggests that the correlation between stratocumulus cloud amount and lower-tropospheric stability exhibits considerable spatial structure and is less pronounced than previously thought
A cluster of MYB transcription factors regulates anthocyanin biosynthesis in carrot (Daucus carota L.) root and petiole
Purple carrots can accumulate large quantities of anthocyanins in their roots and – in some genetic backgrounds-petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F 2 mapping population segregating for root and petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in petioles. In the petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.Fil: Iorizzo, Massimo. North Carolina State University. Department Of Food, Bioprocessing And Nutrition Sciences. Plants For Human Health Institute; Estados UnidosFil: Cavagnaro, Pablo Federico. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Mendoza-San Juan. EstaciĂłn Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de ProducciĂłn Agropecuaria. Cátedra de Horticultura y Floricultura; ArgentinaFil: Bolstan, Hamed. North Carolina State University. Department Of Food, Bioprocessing And Nutrition Sciences. Plants For Human Health Institute; Estados UnidosFil: Zhao, Yunyang. North Carolina State University. Department Of Food, Bioprocessing And Nutrition Sciences. Plants For Human Health Institute; Estados UnidosFil: Zhang, Jianhui. North Carolina State University. Department Of Food, Bioprocessing And Nutrition Sciences. Plants For Human Health Institute; Estados UnidosFil: Simon, Philipp W.. United States Department of Agriculture. Agricultural Research Service; Argentina. University of Wisconsin; Estados Unido
Castling-ViT: Compressing Self-Attention via Switching Towards Linear-Angular Attention During Vision Transformer Inference
Vision Transformers (ViTs) have shown impressive performance but still
require a high computation cost as compared to convolutional neural networks
(CNNs), one reason is that ViTs' attention measures global similarities and
thus has a quadratic complexity with the number of input tokens. Existing
efficient ViTs adopt local attention (e.g., Swin) or linear attention (e.g.,
Performer), which sacrifice ViTs' capabilities of capturing either global or
local context. In this work, we ask an important research question: Can ViTs
learn both global and local context while being more efficient during
inference? To this end, we propose a framework called Castling-ViT, which
trains ViTs using both linear-angular attention and masked softmax-based
quadratic attention, but then switches to having only linear angular attention
during ViT inference. Our Castling-ViT leverages angular kernels to measure the
similarities between queries and keys via spectral angles. And we further
simplify it with two techniques: (1) a novel linear-angular attention
mechanism: we decompose the angular kernels into linear terms and high-order
residuals, and only keep the linear terms; and (2) we adopt two parameterized
modules to approximate high-order residuals: a depthwise convolution and an
auxiliary masked softmax attention to help learn both global and local
information, where the masks for softmax attention are regularized to gradually
become zeros and thus incur no overhead during ViT inference. Extensive
experiments and ablation studies on three tasks consistently validate the
effectiveness of the proposed Castling-ViT, e.g., achieving up to a 1.8% higher
accuracy or 40% MACs reduction on ImageNet classification and 1.2 higher mAP on
COCO detection under comparable FLOPs, as compared to ViTs with vanilla
softmax-based attentions.Comment: CVPR 202
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A methodology to create prototypical building energy models for existing buildings: A case study on US religious worship buildings
Prototypical building energy models are of great significance because they are the starting point in conducting analyses for various applications, such as building energy saving potential analysis, building design, building energy market evaluation, and building energy policy-making. However, current prototypical building energy models only represent limited types of buildings in certain countries. To fill the gap, this paper proposes a methodology to systematically create prototypical building energy models. First, a six-step methodology is introduced: model input identification, data collection, data cleaning, data conversion, model simulation, and model calibration. Then, the methodology is demonstrated by a case study of creating 30 prototypical energy models for U.S. religious worship buildings, representing buildings in 15 climate zones and 2 vintages (pre- and post-1980). Finally, to show the applications of the models, the building energy saving potentials from six efficiency measures are analyzed for pre-1980 U.S. religious worship buildings in three ASHRAE Climate Zones. The results show that the maximum energy saving potentials are approximately 30% for the religious worship buildings in all three climate zones investigated, indicating significant opportunities for energy savings in these buildings through their prototypical building model development.</p
Thymoquinone Attenuates Myocardial Ischemia/Reperfusion Injury Through Activation of SIRT1 Signaling
Background/Aims: Myocardial ischemia/reperfusion (MI/R) injury is a leading factor responsible for damage in myocardial infarction, resulting in additional injury to cardiac tissues involved in oxidative stress, inflammation, and apoptosis. Thymoquinone (TQ), the main constituent of Nigella sativa L. seeds, has been reported to possess various biological activities. However, few reports regarding myocardial protection are available at present. Therefore, this study was conducted aiming to investigate the protective effect of TQ against MI/R injury and to clarify its potential mechanism. Methods: MI/R injury models of isolated rat hearts and neonatal rat cardiomyocytes were established. The Langendorff isolated perfused heart system, triphenyltetrazolium chloride staining, gene transfection, TransLaser scanning confocal microscopy, and western blotting were employed to evaluate the cardioprotection effect of TQ against MI/R injury. Results: Compared with the MI/R group, TQ treatment could remarkably improve left ventricular function, decrease myocardial infarct size and production of lactate dehydrogenase (LDH), and attenuate mitochondrial oxidative damage by elevating superoxide dismutase (SOD) activity and reducing production of hydrogen peroxide (H2O2) and malonaldehyde (MDA). Moreover, the cardioprotective effect of TQ was accompanied by up-regulated expression of SIRT1 and inhibition of p53 acetylation. Additionally, TQ treatment could also enhance mitochondrial function and reduce the number of apoptotic cardiomyocytes. Nonetheless, the cardioprotective effect of TQ could be mitigated by SIRT1 inhibitor sirtinol and SIRT1 siRNA, respectively, which was achieved through inhibition of the SIRT1 signaling pathway. Conclusions: The findings in this study demonstrate that TQ is efficient in attenuating MI/R injury through activation of the SIRT1 signaling pathway, which can thus reduce mitochondrial oxidative stress damage and cardiomyocyte apoptosis
Automatic Segmentation of Nature Object Using Salient Edge Points Based Active Contour
Natural image segmentation is often a crucial first step for high-level image understanding, significantly reducing the complexity of content analysis of images. LRAC may have some disadvantages. (1) Segmentation results heavily depend on the initial contour selection which is a very skillful task. (2) In some situations, manual interactions are infeasible. To overcome these shortcomings, we propose a novel model for unsupervised segmentation of viewer’s attention object from natural images based on localizing region-based active model (LRAC). With aid of the color boosting Harris detector and the core saliency map, we get the salient object edge points. Then, these points are employed as the seeds of initial convex hull. Finally, this convex hull is improved by the edge-preserving filter to generate the initial contour for our automatic object segmentation system. In contrast with localizing region-based active contours that require considerable user interaction, the proposed method does not require it; that is, the segmentation task is fulfilled in a fully automatic manner. Extensive experiments results on a large variety of natural images demonstrate that our algorithm consistently outperforms the popular existing salient object segmentation methods, yielding higher precision and better recall rates. Our framework can reliably and automatically extract the object contour from the complex background
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Performance evaluation of heating tower heat pump systems over the world
Heating tower heat pumps (HTHPs) are proposed as an alternative to the conventional heat pumps. However, lacking performance evaluation of the HTHPs in different regions limits their applications worldwide. To address this issue, this paper carries out a large-scale comprehensive performance evaluation of the HTHPs in 869 typical locations. These locations are in the warm, mixed, and cool climate zones, where buildings need both cooling and heating supply. Seven performance indices are adopted, including the annual coefficient of performance (COP), COP in cooling season, COP in heating season, regeneration ratio, number of unsatisfactory hours, matching degree of heat pump, and matching degree of heating tower. The performance evaluation of the HTHPs is conducted by the processes of location selection, building load calculation, system sizing, simulation, and evaluation. The results show that the HTHPs have excellent performance in the warm and mixed climate zones, where the average annual COPs are 4.67 and 3.68, respectively. The HTHPs are also applicable in the cool climate zone with an average annual COP of 3.11. The distributions of all the performance indices are presented through color maps, and the results are analyzed considering the air temperature and relative humidity data of the locations.</p
Long-Short-Range Message-Passing: A Physics-Informed Framework to Capture Non-Local Interaction for Scalable Molecular Dynamics Simulation
Computational simulation of chemical and biological systems using ab initio
molecular dynamics has been a challenge over decades. Researchers have
attempted to address the problem with machine learning and fragmentation-based
methods, however the two approaches fail to give a satisfactory description of
long-range and many-body interactions, respectively. Inspired by
fragmentation-based methods, we propose the Long-Short-Range Message-Passing
(LSR-MP) framework as a generalization of the existing equivariant graph neural
networks (EGNNs) with the intent to incorporate long-range interactions
efficiently and effectively. We apply the LSR-MP framework to the recently
proposed ViSNet and demonstrate the state-of-the-art results with up to
error reduction for molecules in MD22 and Chignolin datasets. Consistent
improvements to various EGNNs will also be discussed to illustrate the general
applicability and robustness of our LSR-MP framework
Endowing improved osteogenic activities with collagen membrane by incorporating biocompatible iron oxide nanoparticles
Introduction: Collagen-based scaffolds, renowned for their exceptional biocompatibility, have garnered attention as promising scaffolds for advancing bone tissue regeneration. Nevertheless, these scaffolds possess inherent limitations, such as notably compromised osteo-conductivity and osteo-inductivity.Methods: Our study focused on enhancing the mechanical properties and osteogenic bioactivities of bovine-derived collagen membranes (CMs) from the Achilles tendon by incorporating FDA-approved iron oxide nanoparticles (IONPs), termed as IONP-CM. Three types of IONP-CMs (IONP-CM-0.5, IONP-CM-1, and IONPCM-1.5) were constructed by altering the amounts of feeding IONPs.Results: Surface topography analysis demonstrated comparable characteristics between the IONP-CM and neat CM, with the former exhibiting augmented mechanical properties. In vitro evaluations revealed the remarkable biocompatibility of IONP-CMs toward mouse calvarial pre-osteoblast MC3T3-E1 cells, concurrently stimulating osteogenic differentiation. Mechanistic investigations unveiled that the osteogenic differentiation induced by IONP-CMs stemmed from the activation of the Wnt/β-catenin signaling pathway. Furthermore, in vivo bone regeneration assessment was performed by implanting IONP-CMs into the radial defect in rabbits. Results derived from micro-computed tomography and histological analyses unequivocally substantiated the capacity of IONP-CMs to expedite bone repair processes.Discussion: IONP-CMs emerged as scaffolds boasting exceptional biocompatibility and enhanced osteogenic properties, positioning them as promising candidates for facilitating bone tissue regeneration
Performance of screening tests for oesophageal squamous cell carcinoma: a systematic review and meta-analysis
Background and Aims:
This systematic review and meta-analysis aims to compare the pooled diagnostic accuracy of the currently available esophageal squamous cell carcinoma (ESCC) screening tests.
Methods:
A comprehensive literature search of Embase and Medline (up to October 31, 2020) was performed to identify eligible studies. We pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) for ESCC screening tools using a bivariate random-effects model. The summary receiver operating characteristic (sROC) curves with area under the curve (AUC) were plotted for each screening test.
Results:
We included 161 studies conducted in 81 research articles involving 32,209 subjects. The pooled sensitivity, specificity, and AUC (95% CIs) of the major screening tools were: (1). Endoscopy (per-oral endoscopy): 0.94 (0.87-0.97), 0.92 (0.87-0.95), and 0.97 (0.96-0.99); (2) Endoscopy (transnasal endoscopy): 0.85 (0.70-0.93), 0.96 (0.91-0.98), and 0.97 (0.95, -0.98); (3). MicroRNA: 0.77 (0.75-0.80), 0.78 (0.75-0.80), and 0.85 (0.81-0.87); (4). Autoantibody: 0.45 (0.36-0.53), 0.91 (0.89-0.93), and 0.84 (0.81-0.87); and (5). Cytology: 0.82 (0.60-0.93), 0.97 (0.88-0.99), and 0.97 (0.95-0.98). There was high heterogeneity.
Conclusions:
The diagnostic accuracy seems comparable between Cytology and endoscopy, whilst autoantibody and microRNAs bear potential as future non-invasive screening tools for ESCC. To reduce ESCC-related death in the high-risk populations, it is important to develop a more accurate and less invasive screening test
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