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1.
Neural Netw ; 172: 106134, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38245924

RESUMO

Natural data typically exhibits a long-tailed distribution, presenting great challenges for recognition tasks. Due to the extreme scarcity of training instances, tail classes often show inferior performance. In this paper, we investigate the problem within the trendy visual-language (VL) framework and find that the performance bottleneck mainly arises from the recognition confusion between tail classes and their highly correlated head classes. Building upon this observation, unlike previous research primarily emphasizing class frequency in addressing long-tailed issues, we take a novel perspective by incorporating a crucial additional factor namely class correlation. Specifically, we model the representation learning procedure for each sample as two parts, i.e., a special part that learns the unique properties of its own class and a common part that learns shared characteristics among classes. By analysis, we discover that the learning process of common representation is easily biased toward head classes. Because of the bias, the network may lean towards the biased common representation as classification criteria, rather than prioritizing the crucial information encapsulated within the specific representation, ultimately leading to recognition confusion. To solve the problem, based on the VL framework, we introduce the rectification contrastive term (ReCT) to rectify the representation bias, according to semantic hints and training status. Extensive experiments on three widely-used long-tailed datasets demonstrate the effectiveness of ReCT. On iNaturalist2018, it achieves an overall accuracy of 75.4%, surpassing the baseline by 3.6 points in a ResNet-50 visual backbone.


Assuntos
Idioma , Semântica , Viés , Aprendizagem , Reconhecimento Psicológico
2.
IEEE Trans Pattern Anal Mach Intell ; 45(11): 13876-13892, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37486845

RESUMO

Long-tail distribution is widely spread in real-world applications. Due to the extremely small ratio of instances, tail categories often show inferior accuracy. In this paper, we find such performance bottleneck is mainly caused by the imbalanced gradients, which can be categorized into two parts: (1) positive part, deriving from the samples of the same category, and (2) negative part, contributed by other categories. Based on comprehensive experiments, it is also observed that the gradient ratio of accumulated positives to negatives is a good indicator to measure how balanced a category is trained. Inspired by this, we come up with a gradient-driven training mechanism to tackle the long-tail problem: re-balancing the positive/negative gradients dynamically according to current accumulative gradients, with a unified goal of achieving balance gradient ratios. Taking advantage of the simple and flexible gradient mechanism, we introduce a new family of gradient-driven loss functions, namely equalization losses. We conduct extensive experiments on a wide spectrum of visual tasks, including two-stage/single-stage long-tailed object detection (LVIS), long-tailed image classification (ImageNet-LT, Places-LT, iNaturalist), and long-tailed semantic segmentation (ADE20 K). Our method consistently outperforms the baseline models, demonstrating the effectiveness and generalization ability of the proposed equalization losses.

3.
Plants (Basel) ; 12(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36903983

RESUMO

Glucosinolates are secondary plant metabolites that are part of the plant's defense system against pathogens and pests and are activated via enzymatic degradation by thioglucoside glucohydrolases (myrosinases). Epithiospecifier proteins (ESPs) and nitrile-specifier proteins (NSPs) divert the myrosinase-catalyzed hydrolysis of a given glucosinolate to form epithionitrile and nitrile rather than isothiocyanate. However, the associated gene families have not been explored in Chinese cabbage. We identified three ESP and fifteen NSP genes randomly distributed on six chromosomes in Chinese cabbage. Based on a phylogenetic tree, the ESP and NSP gene family members were divided into four clades and had similar gene structure and motif composition of Brassica rapa epithiospecifier proteins (BrESPs) and B. rapa nitrile-specifier proteins (BrNSPs) in the same clade. We identified seven tandem duplicated events and eight pairs of segmentally duplicated genes. Synteny analysis showed that Chinese cabbage and Arabidopsis thaliana are closely related. We detected the proportion of various glucosinolate hydrolysates in Chinese cabbage and verified the function of BrESPs and BrNSPs in glucosinolate hydrolysis. Furthermore, we used quantitative RT-PCR to analyze the expression of BrESPs and BrNSPs and demonstrated that these genes responded to insect attack. Our findings provide novel insights into BrESPs and BrNSPs that can help further promote the regulation of glucosinolate hydrolysates by ESP and NSP to resist insect attack in Chinese cabbage.

4.
Int J Mol Sci ; 23(22)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36430439

RESUMO

Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most destructive diseases in Brassica rapa. Verticillium dahliae Aspf2-like protein (VDAL) is a secretory protein of V. dahliae which has been shown to enhance the resistance against fungal infections in several plants. Nonetheless, the molecular mechanisms of VDAL-primed disease resistance are still poorly understood. In this study, we performed physiological, biochemical, and transcriptomic analyses of Brassica rapa in order to understand how VDAL confers resistance to S. sclerotiorumn infections in plants. The results showed that foliar application of VDAL significantly reduced the plaque area on leaves inoculated with S. sclerotiorum. It also enhanced antioxidant capacity by increasing activities of superoxide dismutase (SOD), peroxidase (POD), peroxidase (APX), glutathione reductase (GR), protoporphyrinogen oxidase (PPO), and defense-related enzymes ß-1,3-glucanase and chitinase during the infection periods. This occurred in parallel with significantly reduced relative conductivity at different periods and lower malondialdehyde (MDA) content as compared to sole S. sclerotiorum inoculation. Transcriptomic analysis showed a total of 146 (81 up-regulated and 65 down-regulated) differentially expressed genes (DEGs) in VDAL-treated leaves compared to the control. The most enriched three Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were the mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signal transduction, and plant-pathogen interaction, all of which were associated with plant immunity. DEGs associated with MAPK and hormone signal transduction pathways were ethylene response sensor ERS2, EIN3 (Ethylene Insensitive3)-binding F-box protein 2 (EBF2), ethylene-responsive transcription factor ERF94, MAPK 9 (MKK9), protein phosphatase 2C (PP2C37), auxin-responsive proteins (AUX/IAA1 and 19), serine/threonine-protein kinase CTR1, and abscisic acid receptors (PLY 4 and 5). Among the DEGs linked with the plant-pathogen interaction pathway were calmodulin-like proteins (CML5, 24, 27), PTI1-like tyrosine protein kinase 3 (Pti13) and transcription factor MYB30, all of which are known to play key roles in pathogen-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI) for hypersensitive response (HR), cell wall reinforcement, and stomatal closure in plants. Overall, VDLA treatment triggered repression of the auxin and ABA signaling pathways and de-repression of the ethylene signaling pathways in young B. rapa seedlings to increase plant innate immunity. Our results showed that VDAL holds great potential to enhance fungal disease resistance in B. rapa crop.


Assuntos
Ascomicetos , Brassica rapa , Resistência à Doença , Etilenos , Peroxidases , Ácidos Indolacéticos , Proteínas Quinases Ativadas por Mitógeno , Fatores de Transcrição
5.
Int J Mol Sci ; 23(19)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36232971

RESUMO

Heat stress is one of the most common agrometeorological risks in crop production in the middle and lower reaches of the Yangtze River in China. This study aimed to investigate whether glutamic acid (Glu) or poly-γ-glutamic acid (γ-PGA) biostimulants can improve the thermotolerance of a cool-season Chinese cabbage (Brassica rapa L. ssp. pekinensis) crop. Priming with Glu (2.0 mM) or γ-PGA (20 mg·L-1) was conducted at the third leaf stage by applying as daily foliar sprays for 5 days before 5 days of heat stress (45 °C in 16-h light/35 °C in 8-h dark). Coupled with morpho-physiological and biochemical analyses, transcriptomes of Glu or γ-PGA-primed Chinese cabbage under heat stress were examined by RNA-seq analysis. The results showed that the thermotolerance conferred by Glu and γ-PGA priming was associated with the increased parameters of vegetative growth, gas exchange, and chlorophyll fluorescence. Compared with the control, the dry weights of plants treated with Glu and γ-PGA increased by 51.52% and 39.39%, respectively. Glu and γ-PGA application also significantly increased the contents of total chlorophyll by 42.21% and 23.12%, and carotenoid by 32.00% and 24.00%, respectively. In addition, Glu- and γ-PGA-primed plants markedly inhibited the levels of malondialdehyde, electrolyte leakage, and super-oxide anion radical, which was accompanied by enhanced activity levels of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD). Enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) categories within the differentially expressed genes (DEGs) functional clusters of RNA-seq data indicated that the expression levels of the genes for DNA replication, DNA repair system, linoleic acid metabolism, cysteine and methionine metabolism, glutathione metabolism, purine and pyrimidine metabolism, carotenoid biosynthesis, and plant-pathogen interaction were commonly up-regulated by both Glu and γ-PGA priming. Glu treatment enhanced the expression levels of the genes involved in aliphatic glucosinolate and 2-oxocarboxylic acid, while γ-PGA treatment activated carotenoid cleavage reaction to synthesize abscisic acid. Taken together, both Glu and γ-PGA have great potential for the preadaptation of Chinese cabbage seedlings to heat stress, with Glu being more effective than γ-PGA.


Assuntos
Brassica rapa , Brassica , Ácido Abscísico/metabolismo , Ânions/metabolismo , Ascorbato Peroxidases/metabolismo , Brassica/metabolismo , Brassica rapa/genética , Catalase/metabolismo , Clorofila/metabolismo , Cisteína/metabolismo , Glucosinolatos/metabolismo , Ácido Glutâmico/metabolismo , Glutationa/metabolismo , Ácido Linoleico/metabolismo , Malondialdeído/metabolismo , Metionina/metabolismo , Óxidos/metabolismo , Fotossíntese , Ácido Poliglutâmico/análogos & derivados , Purinas/metabolismo , Pirimidinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
6.
Plants (Basel) ; 11(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35567214

RESUMO

Heat stress is one of the major abiotic factors that limit the growth, development, and productivity of plants. Both glycine betaine (GB) and ß-aminobutyric acid (BABA) have received considerable attention due to their roles in stimulating tolerance to diverse abiotic stresses. In order to understand how GB and BABA biostimulants alleviate heat stress in a cool-weather Chinese cabbage (Brassica rapa L. ssp. pekinensis) plant, we investigated the GB- and BABA-primed heat-stressed plants in terms of their morpho-physiological and biochemical traits. Priming with GB (15 mM) and BABA (0.2 mM) was conducted at the third leaf stage by applying foliar sprays daily for 5 days before 5 days of heat stress (45 °C in 16 h light/35 °C in 8 h dark) on Chinese cabbage seedlings. The results indicate that GB and BABA significantly increased chlorophyll content, and the parameters of both gas exchange and chlorophyll fluorescence, of Chinese cabbage under heat stress. Compared with the unprimed heat-stressed control, the dry weights of GB- and BABA-primed plants were significantly increased by 36.36% and 45.45%, respectively. GB and BABA priming also greatly mitigated membrane damage, as indicated by the reduction in malondialdehyde (MDA) and electrolyte leakage through the elevation of proline content, and increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Taken together, GB and BABA have great potential to enhance the thermotolerance of Chinese cabbage through higher photosynthesis performance, osmoprotection, and antioxidant enzyme activity.

7.
J Hum Hypertens ; 36(2): 126-134, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215840

RESUMO

Hypertension is a leading risk factor of cardiovascular disease and it is becoming increasingly prevalent globally. Correspondingly, the Chinese government and public health institutions have issued a series of policy documents and guidelines for hypertension. However, no comprehensive review of such documents has been conducted. Hence, this review aims to provide an up-to-date and comprehensive assessment of not only the disease burden, but also hypertension management policies and guidelines in China. A total of 15 epidemiological studies based on national population surveys, 15 Chinese Hypertension Guidelines, and seven policy documents were identified. We found a larger burden of hypertension in men, while the awareness, treatment, and control rates have remained low in both sexes. The ranges of hypertension prevalence, awareness, treatment, and control rate among hypertensive patients were 18.0-44.7%, 23.6-56.2%, 14.2-48.5%, and 4.2-30.1% respectively. Chinese hypertension guidelines provide evidence-based instructions to healthcare practitioners over hypertension management in which primary healthcare is increasingly emphasized. Finally, the policy documents set national goals for hypertension management and standardized the services provided in primary healthcare. The findings highlight the importance of integrating new guidelines into hypertension management provided by primary healthcare practitioners and the need to evaluate the implementation of guidelines and policies.


Assuntos
Doenças Cardiovasculares , Hipertensão , China/epidemiologia , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/terapia , Masculino , Políticas
8.
Front Public Health ; 9: 774907, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34869187

RESUMO

Background: There is a lack of evidence concerning the effective implementation of strategies for stroke prevention and management, particularly in resource-limited settings. A primary-care-based integrated mobile health intervention (SINEMA intervention) has been implemented and evaluated via a 1-year-long cluster-randomized controlled trial. This study reports the findings from the trial implementation and process evaluation that investigate the implementation of the intervention and inform factors that may influence the wider implementation of the intervention in the future. Methods: We developed an evaluation framework by employing both the RE-AIM framework and the MRC process evaluation framework to describe the implementation indicators, related enablers and barriers, and illustrate some potential impact pathways that may influence the effectiveness of the intervention in the trial. Quantitative data were collected from surveys and extracted from digital health monitoring systems. In addition, we conducted quarterly in-depth interviews with stakeholders in order to understand barriers and enablers of program implementation and effectiveness. Quantitative data analysis and thematic qualitative data analysis were applied, and the findings were synthesized based on the evaluation framework. Results: The SINEMA intervention was successfully implemented in 25 rural villages, reached 637 patients with stroke in rural Northern China during the 12 months of the trial. Almost 90% of the participants received all follow-up visits per protocol, and about half of the participants received daily voice messages. The majority of the intervention components were adopted by village doctors with some adaptation made. The interaction between human-delivered and technology-enabled components reinforced the program implementation and effectiveness. However, characteristics of the participants, doctor-patient relationships, and the healthcare system context attributed to the variation of program implementation and effectiveness. Conclusion: A comprehensive evaluation of program implementation demonstrates that the SINEMA program was well implemented in rural China. Findings from this research provide additional information for program adaptation, which shed light on the future program scale-up. The study also demonstrates the feasibility of combining RE-AIM and MRC process evaluation frameworks in process and implementation evaluation in trials. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03185858.


Assuntos
Acidente Vascular Cerebral , Telemedicina , China , Humanos , Atenção Primária à Saúde , População Rural , Acidente Vascular Cerebral/prevenção & controle
9.
Glob Heart ; 15(1): 73, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33150138

RESUMO

Background: Hypertension and related complications are major contributors to morbidity and mortality in Nepal. Community health workers have been proposed as promising health cadres to meet the growing healthcare demand for non-communicable disease management in other developing countries. Objective: We aimed to explore existing workflows, needs and challenges for hypertension care coordination and to assess the feasibility of establishing a Female Community Health Volunteer (FCHV)-based hypertension management program in Kavre, Nepal. Design: We conducted one focus group discussion with eight FCHVs and twenty-three in-depth interviews with four FCHVs not attending FGD, nine individuals with hypertension, six health workers, and four health officials in two village development committees of Kavre District, Nepal. Applied thematic analysis was performed using NVivo 12. Results: Health literacy related to hypertension was low among both community members and FCHVs. Delay in treatment initiation and loss to follow-up were common patterns despite anti-hypertensive medication compliance. Major health system-related barriers included underutilization of primary healthcare institutions, communication gaps and lack of grass-roots level educational campaigns. Community pharmacies, monthly health camps and increasing governmental attention to NCDs were favorable for improving hypertension management. This study also supports that FCHVs should be provided with adequate training and financial incentives to promote hypertension education, screening and referral in their catchments. Conclusions: Barriers and facilitators identified in this study provide important implications for future hypertension management in Nepal. We recommend hypertension education and screening across Nepal at a grass-root level through FCHVs. Providing professional training and proper financial incentives for FCHVs are warranted. Highlights: Health literacy related to hypertension was low among both community members and Female Community Health Volunteers in Nepal.Delay in treatment initiation and loss to follow-up were common despite relatively high anti-hypertensive medication compliance.Health system-related barriers in research sites included underutilization of primary healthcare institutions, communication gaps, and lack of grass-roots level educational campaigns.Female Community Health Volunteers should be provided with adequate training and financial incentives to promote hypertension management.


Assuntos
Agentes Comunitários de Saúde/educação , Atenção à Saúde/normas , Educação em Saúde/métodos , Hipertensão/prevenção & controle , Pesquisa Qualitativa , Voluntários/educação , Saúde da Mulher , Estudos de Viabilidade , Feminino , Humanos , Hipertensão/epidemiologia , Incidência , Pessoa de Meia-Idade , Nepal/epidemiologia
11.
JMIR Mhealth Uhealth ; 8(3): e15419, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32149712

RESUMO

BACKGROUND: Hypertension is a major modifiable risk factor for cardiovascular disease, the world's leading cause of death. The prevalence of hypertension is disproportionately higher in South Asian countries than in other regions of the world. Screening for hypertension in primary care settings remains a challenge in many South Asian countries, including Nepal. Nepal is located in the Himalayan Mountains region, posing significant geographical challenges for its rural citizens to access primary health care and service delivery. This barrier increases the costs and inconvenience for rural Nepalis to access hypertension screening and treatment. As a result, the prevalence of hypertension in Nepal tripled in the last 25 years to 22.4%-38.6%. Nepal's Ministry of Health and Population relies on female community health volunteers to link health centers and communities to provide basic health services. Over 50,000 of these volunteers in Nepal have received basic health care training and are assigned to take care of maternal and child health. Due to limited health care resources, adopting new methods to control hypertension is an urgent need in Nepal. Several recent studies in Nepal have recommended extending the role of female community health volunteers to include hypertension management through blood pressure monitoring and home-based education. OBJECTIVE: The goal of this study was to assess if a mobile health-based female community health volunteer approach of combining the traditional community health volunteer program with digital technologies would be feasible and acceptable in rural Nepal. METHODS: In this study, we recruited 17 female community health volunteers and extended their role from maternal and child health to hypertension management through screening blood pressures. RESULTS: All 17 female community health volunteers successfully measured 1113 rural Nepalis' blood pressures, identified 169 hypertensive patients, and collected health behaviors data of the 169 hypertensive patients. Among the 169 patients, 70% of them had a mobile phone, and 92% were interested in receiving health-related information via a mobile phone. Among those who were interested in receiving information via a mobile phone, 84% preferred voice calls, and 7% and 1% preferred texting and apps, respectively. CONCLUSIONS: Results from this study indicate that a digital health intervention that leverages feature-phones combined with female community health volunteers may be an acceptable and pragmatic way to implement an evidence-based program to reduce hypertension in rural Nepal.


Assuntos
Hipertensão , Telemedicina , Agentes Comunitários de Saúde , Estudos Transversais , Estudos de Viabilidade , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/prevenção & controle , Masculino , Nepal/epidemiologia , Saúde Pública , Voluntários
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