28 research outputs found

    Counting Homomorphisms Modulo a Prime Number

    Get PDF
    Counting problems in general and counting graph homomorphisms in particular have numerous applications in combinatorics, computer science, statistical physics, and elsewhere. One of the most well studied problems in this area is #GraphHom(H) --- the problem of finding the number of homomorphisms from a given graph G to the graph H. Not only the complexity of this basic problem is known, but also of its many variants for digraphs, more general relational structures, graphs with weights, and others. In this paper we consider a modification of #GraphHom(H), the #_p GraphHom(H) problem, p a prime number: Given a graph G, find the number of homomorphisms from G to H modulo p. In a series of papers Faben and Jerrum, and Goebel et al. determined the complexity of #_2 GraphHom(H) in the case H (or, in fact, a certain graph derived from H) is square-free, that is, does not contain a 4-cycle. Also, Goebel et al. found the complexity of #_p GraphHom(H) for an arbitrary prime p when H is a tree. Here we extend the above result to show that the #_p GraphHom(H) problem is #_p P-hard whenever the derived graph associated with H is square-free and is not a star, which completely classifies the complexity of #_p GraphHom(H) for square-free graphs H

    Developing Dementia-Friendly Tourism Destinations: An Exploratory Analysis

    Get PDF
    Dementia is emerging as a global issue. Increases in life expectancy create an older population structure with accompanying health needs but also high lifestyle expectations. For example existing generations have come to expect to be able to participate in leisure and tourism activities in later life, which can be constrained by the onset of dementia. Leading healthy lifestyles and engaging in tourism activities are viewed as fundamental to remaining active and contributing to slowing the progress of dementia. This study is the first to examine the challenges and implications of the growing scale of dementia and the business opportunities this may create for destinations wishing to achieve dementia-friendly status. The paper reports results from an initial scoping study with tourism businesses in a coastal resort in the United Kingdom with such ambitions to assess the nature of the issues that arose from a series of face-to-face interviews

    Dental caries in primary and permanent teeth in children's worldwide, 1995 to 2019: a systematic review and meta-analysis

    Get PDF
    Background: Early childhood caries (ECC) is a type of dental caries in the teeth of infants and children that is represented as one of the most prevalent dental problems in this period. Various studies have reported different types of prevalence of dental caries in primary and permanent teeth in children worldwide. However, there has been no comprehensive study to summarize the results of these studies in general, so this study aimed to determine the prevalence of dental caries in primary and permanent teeth in children in different continents of the world during a systematic review and meta-analysis. Methods: In this review study, articles were extracted by searching in the national and international databases of SID, MagIran, IranMedex, IranDoc, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (ISI) between 1995 and December 2019. Random effects model was used for analysis and heterogeneity of studies was evaluated by using the I2 index. Data were analyzed by using the Comprehensive Meta-Analysis (Version 2) software. Findings: In this study, a total of 164 articles (81 articles on the prevalence of dental caries in primary teeth and 83 articles on the prevalence of dental caries in permanent teeth) were entered the meta-analysis. The prevalence of dental caries in primary teeth in children in the world with a sample size of 80,405 was 46.2% (95% CI: 41.6–50.8%), and the prevalence of dental caries in permanent teeth in children in the world with a sample size of 1,454,871 was 53.8% (95% CI: 50–57.5%). Regarding the heterogeneity on the basis of meta-regression analysis, there was a significant difference in the prevalence of dental caries in primary and permanent teeth in children in different continents of the world. With increasing the sample size and the year of study, dental caries in primary teeth increased and in permanent teeth decreased. Conclusion: The results of this study showed that the prevalence of primary and permanent dental caries in children in the world was found to be high. Therefore, appropriate strategies should be implemented to improve the aforementioned situation and to troubleshoot and monitor at all levels by providing feedback to hospitals

    Review on composition and antimicrobial effects of Teucrium (Teucrium polium L.) grown in Iran and comparison with the around the world

    Get PDF
    BACKGROUND AND OBJECTIVE: Teucrium polium plant from Lamiaceae family and evolvable in a range of climate types and used in traditional medicine to treat diseases and also has antimicrobial effects is significant. This paper was done to compare the antimicrobial effects T. polium plants grown in Iran with the around of the world. METHODS: In this review study using keywords Essential oil, Medicinal Plants and Teucrium searching was done in the databases Pubmed, Science Direct, Elsevier, SID, Magiran, Google Scholar, Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO). FINDINGS: A total of 269 articles were identified with the desired subject of who 86 were selected for further investigation. Failure to select other articles, was away from the goal the finding of this study showed that the α-Pinene, β-Pinene, Spathulenol, Verbenene, β-Myrcene were the main components of T. polium essential oil was grown in Iran. Amount of MIC, MBC value against pathogenic bacteria and inhibition diameter of T. polium was grown in Iran In comparison with the elsewhere in the world was not significant. CONCLUSION: T. polium plant can be used as an effective antimicrobial compounds. The dose should be determined in various experiments and controlled manner taking the risk of toxicity occurs

    Review on composition and antimicrobial effects of Teucrium (Teucrium polium L.) grown in Iran and comparison with the around the world

    No full text
    BACKGROUND AND OBJECTIVE: Teucrium polium plant from Lamiaceae family and evolvable in a range of climate types and used in traditional medicine to treat diseases and also has antimicrobial effects is significant. This paper was done to compare the antimicrobial effects T. polium plants grown in Iran with the around of the world. METHODS: In this review study using keywords Essential oil, Medicinal Plants and Teucrium searching was done in the databases Pubmed, Science Direct, Elsevier, SID, Magiran, Google Scholar, Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO). FINDINGS: A total of 269 articles were identified with the desired subject of who 86 were selected for further investigation. Failure to select other articles, was away from the goal the finding of this study showed that the α-Pinene، β-Pinene، Spathulenol, Verbenene, β-Myrcene were the main components of T. polium essential oil was grown in Iran. Amount of MIC, MBC value against pathogenic bacteria and inhibition diameter of T. polium was grown in Iran In comparison with the elsewhere in the world was not significant. CONCLUSION: T. polium plant can be used as an effective antimicrobial compounds. The dose should be determined in various experiments and controlled manner taking the risk of toxicity occurs

    Anomaly-aware multiple instance learning for rare anemia disorder classification.

    No full text
    Deep learning-based classification of rare anemia disorders is challenged by the lack of training data and instance-level annotations. Multiple Instance Learning (MIL) has shown to be an effective solution, yet it suffers from low accuracy and limited explainability. Although the inclusion of attention mechanisms has addressed these issues, their effectiveness highly depends on the amount and diversity of cells in the training samples. Consequently, the poor machine learning performance on rare anemia disorder classification from blood samples remains unresolved. In this paper, we propose an interpretable pooling method for MIL to address these limitations. By benefiting from instance-level information of negative bags (i.e., homogeneous benign cells from healthy individuals), our approach increases the contribution of anomalous instances. We show that our strategy outperforms standard MIL classification algorithms and provides a meaningful explanation behind its decisions. Moreover, it can denote anomalous instances of rare blood diseases that are not seen during the training phase
    corecore