297 research outputs found

    Adaptive Tag Selection for Image Annotation

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    Not all tags are relevant to an image, and the number of relevant tags is image-dependent. Although many methods have been proposed for image auto-annotation, the question of how to determine the number of tags to be selected per image remains open. The main challenge is that for a large tag vocabulary, there is often a lack of ground truth data for acquiring optimal cutoff thresholds per tag. In contrast to previous works that pre-specify the number of tags to be selected, we propose in this paper adaptive tag selection. The key insight is to divide the vocabulary into two disjoint subsets, namely a seen set consisting of tags having ground truth available for optimizing their thresholds and a novel set consisting of tags without any ground truth. Such a division allows us to estimate how many tags shall be selected from the novel set according to the tags that have been selected from the seen set. The effectiveness of the proposed method is justified by our participation in the ImageCLEF 2014 image annotation task. On a set of 2,065 test images with ground truth available for 207 tags, the benchmark evaluation shows that compared to the popular top-kk strategy which obtains an F-score of 0.122, adaptive tag selection achieves a higher F-score of 0.223. Moreover, by treating the underlying image annotation system as a black box, the new method can be used as an easy plug-in to boost the performance of existing systems

    Beyond the Known: Novel Class Discovery for Open-world Graph Learning

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    Node classification on graphs is of great importance in many applications. Due to the limited labeling capability and evolution in real-world open scenarios, novel classes can emerge on unlabeled testing nodes. However, little attention has been paid to novel class discovery on graphs. Discovering novel classes is challenging as novel and known class nodes are correlated by edges, which makes their representations indistinguishable when applying message passing GNNs. Furthermore, the novel classes lack labeling information to guide the learning process. In this paper, we propose a novel method Open-world gRAph neuraL network (ORAL) to tackle these challenges. ORAL first detects correlations between classes through semi-supervised prototypical learning. Inter-class correlations are subsequently eliminated by the prototypical attention network, leading to distinctive representations for different classes. Furthermore, to fully explore multi-scale graph features for alleviating label deficiencies, ORAL generates pseudo-labels by aligning and ensembling label estimations from multiple stacked prototypical attention networks. Extensive experiments on several benchmark datasets show the effectiveness of our proposed method

    Traceable attribute-based encryption scheme with key-delegation abuse resistance

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    Aiming at the problem that the traceability of a traceable attribute-based encryption (ABE) scheme was not sufficient to address the key abuse completely,a traceable ABE scheme against key-delegation abuse was proposed.A secret parameter was be shared to all user private key components corresponding to attributes,and the decryption was completed by using all these components together,such that only parts of them could not realize the decryption and the real key-delegation abuse resistance ability was be obtained consequently.A short signature technique was employed to prevent the tracing parameter embedded in a user private key from being forged,so as to achieve the traceability of the user who leaked his user private key.Supporting both key-delegation abuse resistance and user tracing enhances the security of the proposed scheme.And compared with related schemes,the proposed scheme has better advantage in terms of the parameters size and the computation cost

    Assessment of cataract surgical outcomes in settings where follow-up is poor: PRECOG, a multicentre observational study

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    Background Poor follow-up after cataract surgery in developing countries makes assessment of operative quality uncertain. We aimed to assess two strategies to measure visual outcome: recording the visual acuity of all patients 3 or fewer days postoperatively (early postoperative assessment), and recording that of only those patients who returned for the fi nal follow-up examination after 40 or more days without additional prompting. Methods Each of 40 centres in ten countries in Asia, Africa, and Latin America recruited 40–120 consecutive surgical cataract patients. Operative-eye best-corrected visual acuity and uncorrected visual acuity were recorded before surgery, 3 or fewer days postoperatively, and 40 or more days postoperatively. Clinics logged whether each patient had returned for the fi nal follow-up examination without additional prompting, had to be actively encouraged to return, or had to be examined at home. Visual outcome for each centre was defi ned as the proportion of patients with uncorrected visual acuity of 6/18 or better minus the proportion with uncorrected visual acuity of 6/60 or worse, and was calculated for each participating hospital with results from the early assessment of all patients and the late assessment of only those returning unprompted, with results from the fi nal follow-up assessment for all patients used as the standard. Findings Of 3708 participants, 3441 (93%) had fi nal follow-up vision data recorded 40 or more days after surgery, 1831 of whom (51% of the 3581 total participants for whom mode of follow-up was recorded) had returned to the clinic without additional prompting. Visual outcome by hospital from early postoperative and fi nal follow-up assessment for all patients were highly correlated (Spearman’s rs=0·74, p<0·0001). Visual outcome from fi nal followup assessment for all patients and for only those who returned without additional prompting were also highly correlated (rs=0·86, p<0·0001), even for the 17 hospitals with unprompted return rates of less than 50% (rs=0·71, p=0·002). When we divided hospitals into top 25%, middle 50%, and bottom 25% by visual outcome, classifi cation based on fi nal follow-up assessment for all patients was the same as that based on early postoperative assessment for 27 (68%) of 40 centres, and the same as that based on data from patients who returned without additional prompting in 31 (84%) of 37 centres. Use of glasses to optimise vision at the time of the early and late examinations did not further improve the correlations. Interpretation Early vision assessment for all patients and follow-up assessment only for patients who return to the clinic without prompting are valid measures of operative quality in settings where follow-up is poor

    Serum cytokine profile of pediatric patients with laboratory confirmed pneumococcal meningitis

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    Background: Streptococcus pneumoniae infection is a leading cause of bacterial meningitis in children with severe sequelae. Cytokines are important molecules in regulating of host inflammatory and antiinflammatory responses. So far, the cytokine profile of bacterial meningitis caused by single pathogen has been rarely reported. The aim of this study was to explore serum cytokine profile in pediatric patients with pneumococcal meningitis (PM) and its clinical relevance which could be considered as a valuable tool for differential diagnosis of PM.Methods: During 2015 & ndash;2018, 95 children with laboratory-confirmed PM were included. Of them, 63 had serum samples at admission. Ten cytokines including TNF-a, IL-12p40, IL-17A, IL-1(3, IFN-eta, GM-CSF, IL-10, CXCL-1, IL-8 and IL-13 were measured by multiplex immunoassay in sera of 63 PM patients and 55 age-matched healthy controls (HCs). Level of serum cytokines was compared with different clinical features of patients.Results: Significantly higher level of IL-10 was observed in patients than HCs (median, 2.19 vs. 1.92 pg/mL, p = 0.017). Significantly lower levels of serum IL-12p40, IL-17A and IL-1 beta were observed in patients than HCs (median, 0.68 vs. 10.12 pg/mL, p Conclusions: Our results suggested that there might be significant changes in serum pro-inflammatory and anti-inflammatory cytokines in PM children and that the determination of these cytokines may have limited value for evaluation of clinical outcome of pediatric PM.(c) 2021 The Author(s). Published by Elsevier Ltd on behalf of King Saud Bin Abdulaziz University for Health Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).</div

    Near-net forming complex shaped Zr-based bulk metallic glasses by high pressure die casting

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    Forming complex geometries using the casting process is a big challenge for bulk metallic glasses (BMGs), because of a lack of time of the window for shaping under the required high cooling rate. In this work, we open an approach named the “entire process vacuum high pressure die casting” (EPV-HPDC), which delivers the ability to fill die with molten metal in milliseconds, and create solidification under high pressure. Based on this process, various Zr-based BMGs were prepared by using industrial grade raw material. The results indicate that the EPV-HPDC process is feasible to produce a glassy structure for most Zr-based BMGs, with a size of 3 mm × 10 mm and with a high strength. In addition, it has been found that EPV-HPDC process allows complex industrial BMG parts, some of which are hard to be formed by any other metal processes, to be net shaped precisely. The BMG components prepared by the EVP-HPDC process possess the advantages of dimensional accuracy, efficiency, and cost compared with the ones formed by other methods. The EVP-HPDC process paves the way for the large-scale application of BMGs

    An investigation of a food poisoning by Galerina sulciceps

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    Objective To investigate a food poisoning caused by wild mushrooms and to identify the risk factors. Methods Epidemiological investigation, morphological and phylogenetic identification, and laboratory testing were taken to analyze the poisoning event. Results All the three cases complained of abdominal pain, vomiting and diarrhea after ingesting the poisonous mushrooms, and liver function impairment was found later. One case died after 5 days. The mushroom was identified as Galerina sulciceps by morphological and phylogenetic identification. Three kinds of toxins, include α-amanitin, β-amanitin and γ-amanitin were detected in laboratory. Conclusion The incident was caused by ingesting the poisonous mushroom, Galerina sulciceps. Public education, market supervision, foodborne disease surveillance should be enhanced, and the ability of medical institutions to diagnose and treat poisonous mushrooms should be improved

    Causal associations between constipation and pan-cancer: a bidirectional Mendelian randomization study

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    ObjectiveObservational studies have suggested a potential association between constipation and several cancers. However, the causal relationship between constipation and cancer remains unclear. The purpose of this study is to explore the potential causal relationship between constipation and pan-cancer using Mendelian Randomization (MR) methods.MethodsWe performed a bidirectional MR analysis using publicly available summary data from Genome-Wide Association Studies (GWAS) statistics. The Inverse Variance Weighted (IVW) method was used as the main analysis method. We also used four MR methods: MR-Egger, Weighted Median, MR-PRESSO and MR.RAPS. Simultaneously, MR-Egger regression, Cochran’s Q test and MR-PRESSO Global test were used to estimate the pleiotropy and heterogeneity of SNPs. In addition, we performed “leave-one-out” analyses” to avoid bias caused by horizontal pleiotropy of individual SNPs.ResultsMR analysis revealed a potential causal association between constipation and the risk of colorectal cancer (CRC) [IVW (OR= 1.0021 (1.0003, 1.0039), P= 0.0234)], lung cancer (LC) [IVW (OR=1.0955 (1.0134, 1.1843), P=0.0218)], Oral cavity and pharyngeal cancer (OPC) [IVW (OR=1.4068 (1.0070, 1.9652), P=0.0454)], and Pancreatic cancer (PC) [IVW (OR=1.5580 (1.0659, 2.2773), P=0.0221)]. In addition, we explored causal relationships between constipation and 12 other types of cancers, including gastric cancer, esophageal cancer, skin melanoma and so on. All five methods yielded no evidence of a causal association between constipation and the risk of these cancer types. In the reverse MR analysis, there was no evidence of a causal association between cancer and the risk of constipation for all five methods.ConclusionOur bidirectional MR study suggests a potential relationship between constipation and an increased risk of CRC, LC OPC and PC. The underlying mechanisms behind these associations will need to be explored in future experimental studies

    Osteogenesis Capability and Degradation Property Evaluation of Injectable Biomaterials: Comparison of Computed Tomography and Ultrasound

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    Injectable biomaterials, which can be physically inserted into a target site without the use of surgery, have received increasing attention in tissue engineering during the last decade. There is also a growing need for quantitative evaluation of the injectable biomaterial directly and noninvasively. The objectives of this study are to originate a quantitative noninvasive technique for evaluation of in situ forming bone biomaterials and to validate the feasibility of diagnostic ultrasound images analysis technique. The potential of ultrasound for quantitative evaluation of tissue development was compared with computed tomography (CT) in vivo. A strong correlation was witnessed between ultrasound gray-scale values (GV) and volumetric mean of CT value (HUm) (r=0.95). Meanwhile, the volume of the material area could be estimated by ultrasound maximum cross-section pixel, which demonstrates a certain consistency with CT mask volume in 3D reconstruction images (r=0.87). In conclusion, ultrasound imaging, which is corresponding with the traditional CT, can be used to evaluate osteogenesis capability and degradation property of injectable biomaterials. It may be a noninvasive, nonradioactive, and effective aid to monitor ossification and reconstruction of biomaterials at the implant region for bone defect repair
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