642 research outputs found
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Using a citizen science tool to model the health benefits of roadside trees
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Francis Botto, Dictionary of Multimedia and Internet Applications ‐ A Guide for Developers and Users, Chichester, UK: John Wiley & Sons, 1999. ISBN: 0–471–986240. Hardback, x+362 pages, £34.95
Paralog analyses reveal gene duplication events and genes under positive selection in Ixodes scapularis and other ixodid ticks
Background: Hard ticks (family Ixodidae) are obligatory hematophagous ectoparasites of worldwide medical and veterinary importance. The haploid genomes of multiple species of ixodid ticks exceed 1 Gbp, prompting questions regarding gene, segmental and whole genome duplication in this phyletic group. The availability of the genome assembly for the black legged tick, Ixodes scapularis, and transcriptome datasets for multiple species of ticks offers an opportunity to assess the contribution of gene duplication to the genome. Here we developed a bioinformatics pipeline to identify and analyze duplicated genes (paralogs) using gene models from the prostriate tick, I. scapularis IscaW1.1 annotation and expressed sequence tags (ESTs) from I. scapularis and the metastriate ticks, Rhipicephalus microplus (southern cattle tick), R. appendiculatus (brown ear tick) and Amblyomma variegatum (tropical bont tick).
Results: Approximately 1-2 % of I. scapularis gene models and 2-14 % of ESTs from the four species represent duplicated genes. The ratio of non-synonymous to synonymous nucleotide substitution rates suggests ~ 25 % of duplicated genes are under positive selection pressure in each species. Analyses of synonymous substitution rates provide evidence for two duplication events in I. scapularis and R. microplus involving several hundred genes. Conservative molecular clock estimates based on synonymous substitution rates for species of Anopheles mosquitoes and the fruit fly, Drosophila melanogaster, suggest these events occurred within the last 50 MYA. Mapping of paralogs to the I. scapularis genome assembly supports tandem, or possibly segmental duplication events.
Conclusions: The present study marks the first genome-level analyses of gene duplication for the Ixodidae and provides insights into mechanisms shaping genome evolution in this group. At least two duplication events involving hundreds of genes may have occurred independently in the lineages prostriata and metastriata, with tandem and segmental duplication the most likely mechanisms for paralog generation. Duplicated genes under positive selection pressure may be linked to emerging functions in the tick and represent important candidates for further study
Knowledge, Perception and Practice of Malaysian Residents on Covid-19 during the Period of the Conditional Movement Control Order
Introduction: Since Malaysia’s first case of Covid-19 was detected early February 2020, cases slowly increased. A Movement Control Order (MCO) was imposed on 18th March 2020 to control spread of the disease. Information on the MCO, the required social behaviour was disseminated through the media. From 4th May 2020 the MCO restrictions were relaxed - thence referred to as the Conditional Movement Order (CMCO). This lasted till 9th June. This study was to determine knowledge, perception, and practice of residents during the CMCO to see if they adhered to the new norms. Methods: This was an analytical cross-sectional study. Inclusion criteria was residents of Malaysia aged 20 to 70 years. A pretested questionnaire with internal validity of 0.751 was used via Google forms. Data converted into categorical variables and analysed using SPSSv23. Statistically significant was p<0.05. Spearman’s co-relation used to determine linear relationship between knowledge and practice and between perception and practice. Results: We had a total of 420 respondents. Significant association of knowledge with age group, marital status, employment, and education level. Good practice was significantly associated with marital status, employment, and education level. A weak but significant relationship between knowledge and practice and between perception and practice. From all, 8.1% feel that Covid-19 is not a dangerous disease
Conclusion: Residents in Malaysia had good knowledge on the new social norms during the CMCO. Overall perceptions and practice scored lower. Focus should be on Health education to ensure residents do not revert to old lifestyle so soon
Salivary melatonin onset in youth at familial risk for bipolar disorder
Melatonin secretion and polysomnography (PSG) were compared among a group of healthy adolescents who were at high familial risk for bipolar disorder (HR) and a second group at low familial risk (LR). Adolescent participants (n = 12) were a mean age 14 ± 2.3 years and included 8 females and 4 males. Saliva samples were collected under standardized condition light (red light) and following a 200 lux light exposure over two consecutive nights in a sleep laboratory. Red Light Melatonin onset (RLMO) was defined as saliva melatonin level exceeding the mean of the first 3 readings plus 2 standard deviations. Polysomnography was also completed during each night. HR youth, relative to LR, experienced a significantly earlier melatonin onset following 200 lux light exposure. Polysomnography revealed that LR youth, relative to HR, spent significantly more time in combined stages 3 and 4 (deep sleep) following red light exposure. Additionally, regardless of the group status (HR or LR), there was no significant difference in Red Light Melatonin Onset recorded at home or in the laboratory, implying its feasibility and reliability
Agency Conflicts and Corporate Payout Policies: A Global Study
We investigate the roles of firm and country level agency conflicts in determining corporate payout policies. Based on a large sample of 29,610 firms in 43 countries from 2001 to 2006, we find that in high protection countries, investors are able to use their legal powers to extract cash from firms but their ability to do so can be substantially hindered when agency costs at the firm level are high. In poor protection countries, investors can seek refuge in firm level governance mechanisms to curb agency conflicts, suggesting a substitution between country and firm level investor protection. Finally, compared to repurchases, we find dividends are more likely to be the sole method of payout in high protection countries and in less closely held firms
Predictive gene signatures:molecular markers distinguishing colon adenomatous polyp and carcinoma
Funding: This study was supported by the Scottish Government's Rural and Environment Science and Analytical Services Division Food, Land and People Programme GT403 (http://www.scotland.gov.uk/Topics/Research/About/EBAR/StrategicResearch/future-research-strategy/Themes), Scottish Universities Life Science Alliance Translational Biology Studentship 10/09, (http://www.sulsa.ac.uk/), NHS Grampian Endowment Fund 12/07 (http://www.nhsgrampian.co.uk/nhsgrampian/gra_display_hospital.jsp?pContentID=65&p_applic=CCC&p_service=Content.show&). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper and its Supporting Information files.Peer reviewedPublisher PD
Agency Conflicts and Corporate Payout Policies: A Global Study
We investigate the roles of firm and country level agency conflicts in determining corporate payout policies. Based on a large sample of 29,610 firms in 43 countries from 2001 to 2006, we find that in high protection countries, investors are able to use their legal powers to extract cash from firms but their ability to do so can be substantially hindered when agency costs at the firm level are high. In poor protection countries, investors can seek refuge in firm level governance mechanisms to curb agency conflicts, suggesting a substitution between country and firm level investor protection. Finally, compared to repurchases, we find dividends are more likely to be the sole method of payout in high protection countries and in less closely held firms
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