Number Of Positive Associations Research Articles

Pediatric Hepatitis and Respiratory Viruses: A Spatiotemporal Ecologic Analysis.

Beginning in early 2022, clusters of severe pediatric hepatitis were reported in Europe and the United States. To date, no cause has been identified although human adenovirus 41 has been proposed in a proportion of cases. We examined population data >11 years for hepatitis clusters in Victoria, Australia, and whether any were spatiotemporally associated with community transmission of common respiratory viruses. We used SaTScan to analyze for clusters of pediatric hepatitis and respiratory adenoviruses in Victoria. Negative binomial regression analysis was performed to determine any associations between hepatitis and respiratory viruses across Victoria between July 1, 2011, and June 30, 2022. A number of positive associations were observed in Victoria between pediatric hepatitis clusters and respiratory viruses in our spatiotemporal analysis. A positive association was not found with respiratory adenoviruses or SARS-CoV-2. Increased hepatitis clusters were observed in 2021 and 2022 as noted internationally. The current hepatitis outbreak is novel and, although respiratory viruses are broadly associated with hepatitis, SARS-CoV-2 and respiratory adenoviruses are unlikely to be related.

Consumers' Perception of Urban Farming—An Exploratory Study

Urban agriculture offers the opportunity to provide fresh, local food to urban communities. However, urban agriculture can only be successfully embedded in urban areas if consumers perceive urban farming positively and accept urban farms in their community. Success of urban agriculture is rooted in positive perception of those living close by, and the perception strongly affects acceptance of farming within individuals’ direct proximity. This research investigates perception and acceptance of urban agriculture by means of a qualitative, exploratory field study with N=19 residents from a major metropolitan area in the southwest U.S. Specifically, the concept mapping procedure was used, where respondents are free to write down all the associations that come to mind when presented with a stimulus, such as, “urban farming.” When applying concept mapping, participants are asked to recall associations and then directly link them to each other displaying their knowledge structure, i.e., perception. Data were analyzed using content analysis and semantic network analysis. Consumers’ perception of urban farming is related to the following categories: environment, society, economy, and food and attributes. The number of positive associations is much higher than the number of negative associations signaling that consumers would be likely to accept farming in close proximity to where they live. Furthermore, our findings show that individuals’ perceptions can differ greatly in terms of what they associate with urban farming and how they evaluate it. While some only think of a few things, others have well-developed knowledge structures. Overall, investigating consumers’ perception helps designing strategies towards developing successful urban farming.

The use of chronic gingivitis as reference status increases the power and odds of periodontitis genetic studies – a proposal based in the exposure concept and clearer resistance and susceptibility phenotypes definition

Current literature on chronic periodontitis genetics encompasses numerous single nucleotide polymorphisms-focused case-control studies with inconsistent and controversial results, which typically disregards the exposure concept embraced by case-control definition. Herein, we propose a case-control design reappraisal by clear phenotype selection, where chronic gingivitis represents a genetically resistant phenotype/genotype opposing the susceptible cohort. The hypothesis was tested in healthy, chronic periodontitis and gingivitis groups through Real-time PCR-based allelic discrimination of classic variants IL1B-3954, IL6-174, TNFA-308, IL10-592 and TLR4-299. Observed allele/genotype frequencies characterize the healthy group with an intermediate genetic profile between periodontitis and gingivitis cohorts. When comparing genotype/allele frequencies in periodontitis versus healthy and periodontitis versus gingivitis scenarios, the number of positive associations (2-4) and the degree of association (p and odds ratio values) were significantly increased by the new approach proposed (periodontitis versus gingivitis), suggesting the association of IL1B-3954, TNFA-308, IL10-592 and TLR4-299 with periodontitis risk. Power study was also significantly improved by the new study design proposed when compared to the traditional approach. The data presented herein support the use of new case-control study design based on the case-control definition and clear resistance/susceptibility phenotypes selection, which can significantly impact the study power and odds of identification of genetic factors involved in PD.

Species composition and interspecific association of plants in primary succession of Mount Merapi, Indonesia

Sutomo, Faradila D, Putri LSE (2011) Species composition and interspecific association of plants in primary succession of Mount Merapi, Indonesia. Biodiversitas 12: 212-217. Primary succession refers to the establishment of plant species and subsequent changes in composition following major disturbance such as volcanic activity. The study of succession may assist in recognizing the possible effects of species interactions (i.e. facilitation or inhibition). The barren landscapes created by volcanic disturbance on Mount Merapi, Java, Indonesia, provide excellent opportunities to study primary succession. Fifty-six species belonging to 26 families were recorded in the five nuées ardentes deposits. The highest number of species belonged to the Asteraceae, then Poaceae, followed by Fabaceae andRubiaceae. In Mount Merapi primary succession, the ecosystem may be developing with time as indicated by the increase in the number of species associations. The number of positive associations was generally higher than the number of negative associations, except in the 2001 deposit where it was equal. Native and alien invasive species had different patterns of interspecific associations. This research demonstrates that in primary succession sites on Mount Merapi, positive interspecific association increased as time progressed, which may support the view that facilitation is more prominent in a severely disturbed habitat as compared to competition.

Patterns of bryophyte associations at different scales in a Norwegian boreal spruce forest

Abstract. Patterns of associations between 36 bryophytes and their relationships with trends in α‐ and β‐diversity were studied at five spatial scales (from 1 m2 to 1/256 m2) in a Norwegian boreal spruce forest. The range and dispersion of α‐diversity values in the data were significantly higher than in comparable model data sets, indicating varation from favourable to unfavourable conditions for bryophytes at all scales, particularly with increasing cover of the upper layers. The number of positive associations was significantly higher than predicted from a random distribution, for all sample plot sizes except the smallest. For the most frequent species, this number decreased with decreasing sample plot size. The excess of positive associations was due to the presence of (1) α‐diversity trends, as demonstrated by a stochastic simulation, and (2) β‐diversity (variation along environmental gradients). A microscale coenocline from dominance of large forest floor mosses to small liverworts, is added to two broad‐scale coenoclines demonstrated earlier. Facilitation ‐ positive density‐dependence caused by more favourable moisture conditions within dense stands ‐ is discussed as a possible third cause of excess positive associations.The number of significant negative associations was generally low, and deviated neither from theoretical values assuming random distribution of species, nor from predicted values accounting for α‐diversity trends. The low proportion of negative associations, even in the presence of β‐diversity trends, suggests that interspecific competition is not important in this vegetation. Several alternatives to competition are discussed; (1) static mechanisms for avoidance of competition, (2) mobility, and (3) the importance of density‐independent mortality, in particular due to fine‐scale disturbance.Simulation studies for assessing the effects of α‐diversity trends on species associations are emphasized.