172 research outputs found

    Hydroclimatic variability in loess delta D-wax records from the central Chinese Loess Plateau over the past 250 ka

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    This study reports hydrogen isotopic records from the central Chinese Loess Plateau (CLP) over the past 250 ka. After eliminating the influence of ice and local temperatures, the delta D-wax records extracted from two loess sites at Xifeng and Luochuan can be taken to represent arid/humid alternations in the hydrological environment in this marginal Asian Summer Monsoon (ASM) region; they also contain integrated information on summer precipitation patterns and the corresponding responses to these changes by predominant vegetation cover types. These arid/humid alternations show 100 ka, 40 ka and 20 ka cycles. An increase in precipitation in association with an enhanced summer monsoon has historically been taken to be the major factor driving a humid environment in the central CLP. However, hydroclimatic changes in delta D-wax records differ for the central CLP, central China and southern China. Over a 20 ka cycle, the influence of solar insolation on hydroclimatic changes can be shown to be consistent throughout the central CLP. However, changes in the relative location of the land and sea may have caused different hydroclimatic responses between southern China and the central CLP on a glacial-interglacial scale. The hydroclimatic variability in the central CLP would suggest that an enhanced summer monsoon due to climatic warming is the key to understanding decreased drought degree in this marginal monsoonal region

    OrdinalCLIP: Learning Rank Prompts for Language-Guided Ordinal Regression

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    This paper presents a language-powered paradigm for ordinal regression. Existing methods usually treat each rank as a category and employ a set of weights to learn these concepts. These methods are easy to overfit and usually attain unsatisfactory performance as the learned concepts are mainly derived from the training set. Recent large pre-trained vision-language models like CLIP have shown impressive performance on various visual tasks. In this paper, we propose to learn the rank concepts from the rich semantic CLIP latent space. Specifically, we reformulate this task as an image-language matching problem with a contrastive objective, which regards labels as text and obtains a language prototype from a text encoder for each rank. While prompt engineering for CLIP is extremely time-consuming, we propose OrdinalCLIP, a differentiable prompting method for adapting CLIP for ordinal regression. OrdinalCLIP consists of learnable context tokens and learnable rank embeddings; The learnable rank embeddings are constructed by explicitly modeling numerical continuity, resulting in well-ordered, compact language prototypes in the CLIP space. Once learned, we can only save the language prototypes and discard the huge language model, resulting in zero additional computational overhead compared with the linear head counterpart. Experimental results show that our paradigm achieves competitive performance in general ordinal regression tasks, and gains improvements in few-shot and distribution shift settings for age estimation. The code is available at https://github.com/xk-huang/OrdinalCLIP.Comment: Accepted by NeurIPS2022. Code is available at https://github.com/xk-huang/OrdinalCLI

    Association between TSH suppression therapy and type 2 deiodinase gene polymorphism in differentiated thyroid carcinoma

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    Introduction: Oral levothyroxine (L-T4) suppression of thyroid-stimulating hormone (TSH) levels is the most commonly used clinical approach to manage and treat patients after thyroid cancer surgery. This study aimed to investigate the association between TSH suppression therapy and type 2 deiodinase gene (DIO2) polymorphism in differentiated thyroid carcinoma (DTC). Material and methods: A total of 240 patients with DTC who received total thyroidectomy (TT; 120) and hemithyroidectomy (HT; 120) were enrolled in this study. The serum TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels were detected using an automatic serum immune analyser and electrochemiluminescence immunoassay. Based on the results of DIO2 gene detection, 3 genotypes of Thr92Ala were detected. Results: The serum TSH levels were inhibited after oral L-T4 treatment, but the proportion of patients who reached the TSH suppression standard in the hemithyroidectomy group was higher than in the total thyroidectomy group. After TSH suppression treatment, serum FT4 levels were increased in both total thyroidectomy and hemithyroidectomy. The difference in serum TSH, FT3, and FT4 levels was associated with different genotypes, and patients with high cytosine cytosine (CC) genotypes may have difficulty meeting the TSH suppression criteria. Conclusions: Patients who underwent total thyroidectomy exhibited higher postoperative serum FT4 levels than patients in the hemithyroidectomy group after TSH suppression therapy. The Thr92Ala polymorphism of type 2 deiodinase (D2) was associated with TSH suppression therapy

    Geo6D: Geometric Constraints Learning for 6D Pose Estimation

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    Numerous 6D pose estimation methods have been proposed that employ end-to-end regression to directly estimate the target pose parameters. Since the visible features of objects are implicitly influenced by their poses, the network allows inferring the pose by analyzing the differences in features in the visible region. However, due to the unpredictable and unrestricted range of pose variations, the implicitly learned visible feature-pose constraints are insufficiently covered by the training samples, making the network vulnerable to unseen object poses. To tackle these challenges, we proposed a novel geometric constraints learning approach called Geo6D for direct regression 6D pose estimation methods. It introduces a pose transformation formula expressed in relative offset representation, which is leveraged as geometric constraints to reconstruct the input and output targets of the network. These reconstructed data enable the network to estimate the pose based on explicit geometric constraints and relative offset representation mitigates the issue of the pose distribution gap. Extensive experimental results show that when equipped with Geo6D, the direct 6D methods achieve state-of-the-art performance on multiple datasets and demonstrate significant effectiveness, even with only 10% amount of data

    Clomazone impact on fungal network complexity and stability

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    IntroductionSoil fungal network composition and stability are important for soil functions, but there is less understanding of the impact of clomazone on network complexity and stability.MethodsIn this work, two agricultural soils were used to investigate the impact of clomazone on fungal network complexity, composition, and stability. The two soils were treated with clomazone solution (0, 0.8, 8, and 80  mg kg−1) and kept in an incubator.Results and DiscussionUnder the influence of clomazone, the fungal network nodes were decreased by 12–42; however, the average degree was increased by 0.169–1.468 and fungal network density was increased by 0.003–0.054. The keystone nodes were significantly changed after clomazone treatment. Network composition was also impacted. Specifically, compared with control and clomazone treatments in both soils, the shared edges were fewer than 54 in all comparisons, and network dissimilarity was 0.97–0.98. These results suggested that fungal network composition was significantly impacted. The network robustness was increased by 0.0018–0.0209, and vulnerability was decreased by 0.00018–0.00059 in both soils, which indicated that fungal network stability was increased by clomazone. In addition, the functions of network communities were also changed in both soils. These results indicated that clomazone could significantly impact soil fungal networks

    Mid-late Holocene temperature and precipitation variations in the Guanting Basin, upper reaches of the Yellow River

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    The reconstruction of prehistoric temperature and precipitation variations in the upper reaches of the Yellow River is essential for understanding the cultural evolution of the region, but related information is sparse due to the limitations of the available proxies. Recent studies have shown that microbial glycerol dialkyl glycerol tetraethers (GDGTs) are promising tools for reconstructing mean annual temperature (MAT) and mean annual precipitation (MAP) in terrestrial deposits. In this study, we reconstructed mid-late Holocene climatic changes using GDGT distributions in a loess-paleosol sequence in the Lajia Ruins of the Neolithic Qijia Culture, Guanting Basin, in the southwestern end of the Chinese Loess Plateau. Our GDGT records show that MAP decreased from ca. 600 mm to 430 mm, while MAT decreased from 11.9 degrees C to 8.0 degrees C, during the past ca. 7000 yr, and a drastic decline in MAP (70 mm), accompanied by a 0.8 degrees C decline in MAT, occurred at 3800-3400 yr BP. Our results provide direct evidence supporting a hypothesis that the flourishing (4200-4000 yr BP) and decline (4000-3600 yr BP) of the Qijia culture (mainly based on millets cultivation) and subsequent rise of the Xindian/Kayue culture (3600-2600 yr BP), based on mixed agriculture of sheep husbandry and millets cultivation were triggered by climate change

    Magnetic propelled hydrogel microrobots for actively enhancing the efficiency of lycorine hydrochloride to suppress colorectal cancer

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    Research and development in the field of micro/nano-robots have made significant progress in the past, especially in the field of clinical medicine, where further research may lead to many revolutionary achievements. Through the research and experiment of microrobots, a controllable drug delivery system will be realized, which will solve many problems in drug treatment. In this work, we design and study the ability of magnetic-driven hydrogel microrobots to carry Lycorine hydrochloride (LH) to inhibit colorectal cancer (CRC) cells. We have successfully designed a magnetic field driven, biocompatible drug carrying hydrogel microsphere robot with Fe3O4 particles inside, which can achieve magnetic field response, and confirmed that it can transport drug through fluorescence microscope. We have successfully demonstrated the motion mode of hydrogel microrobots driven by a rotating external magnetic field. This driving method allows the microrobots to move in a precise and controllable manner, providing tremendous potential for their use in various applications. Finally, we selected drug LH and loaded it into the hydrogel microrobot for a series of experiments. LH significantly inhibited CRC cells proliferation in a dose- and time-dependent manner. LH inhibited the proliferation, mobility of CRC cells and induced apoptosis. This delivery system can significantly improve the therapeutic effect of drugs on tumors

    Targeting oncogenic miR-335 inhibits growth and invasion of malignant astrocytoma cells

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    <p>Abstract</p> <p>Background</p> <p>Astrocytomas are the most common and aggressive brain tumors characterized by their highly invasive growth. Gain of chromosome 7 with a hot spot at 7q32 appears to be the most prominent aberration in astrocytoma. Previously reports have shown that microRNA-335 (miR-335) resided on chromosome 7q32 is deregulated in many cancers; however, the biological function of miR-335 in astrocytoma has yet to be elucidated.</p> <p>Results</p> <p>We report that miR-335 acts as a tumor promoter in conferring tumorigenic features such as growth and invasion on malignant astrocytoma. The miR-335 level is highly elevated in C6 astrocytoma cells and human malignant astrocytomas. Ectopic expression of miR-335 in C6 cells dramatically enhances cell viability, colony-forming ability and invasiveness. Conversely, delivery of antagonist specific for miR-335 (antagomir-335) to C6 cells results in growth arrest, cell apoptosis, invasion repression and marked regression of astrocytoma xenografts. Further investigation reveals that miR-335 targets disheveled-associated activator of morphogenesis 1(Daam1) at posttranscriptional level. Moreover, silencing of endogenous Daam1 (siDaam1) could mimic the oncogenic effects of miR-335 and reverse the growth arrest, proapoptotic and invasion repression effects induced by antagomir-335. Notably, the oncogenic effects of miR-335 and siDAAM1 together with anti-tumor effects of antagomir-335 are also confirmed in human astrocytoma U87-MG cells.</p> <p>Conclusion</p> <p>These findings suggest an oncogenic role of miR-335 and shed new lights on the therapy of malignant astrocytomas by targeting miR-335.</p
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