54 research outputs found

    Modelling freshwater nitrogen and phosphorus across South Asia

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    Nitrogen is essential to life and is a vital nutrient for plant growth and food production, however, its natural cycle has been drastically altered by our activities. Nitrogen pollution is a growing threat to our health, ecosystems and freshwater water bodies. South Asia is one of the affected regions with levels of nitrogen pollution rapidly increasing. In this study, a regional-scale model of freshwater flow and macronutrients (N and P) has been developed for the whole of South Asia. The freshwater model of water quantity (flow) and water quality is based on an existing grid-based model formulation HMF-WA (Hydrological Modelling-Framework for West Africa: Rameshwaran et al. (2021)), coupled with a nutrient-routing approach developed for long-term and large-scale use (LTLS: Bell et al. (2021)). The model combines grid-based runoff-production schemes with a Kinematic Wave (KW) flow routing approach in order to estimate river flows and nutrient fluxes on a regular grid across the region. The model simulates spatially consistent river flows and macronutrient fluxes on a 0.1°×0.1° grid (approximately 10km×10km) continuously across the whole domain. Nutrient inputs to rivers are derived using spatial datasets of land cover and spatiotemporal dominant nutrient sources which are atmospheric deposition, fertiliser application, livestock numbers and human population (Figure 1). Regional scale simulations driven by observed weather data are assessed against observed flows and water quality data before undertaking an analysis of the impact of projected future N scenarios including impacts of technology-based abatement measures and dietary change on pollution

    Infectious Events Prior to Chemotherapy Initiation in Children with Acute Myeloid Leukemia

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    Background:The primary objective was to describe infectious complications in children with acute myeloid leukemia from presentation to the healthcare system to initiation of chemotherapy and to describe how these infections differ depending on neutropenia.Methods:We conducted a retrospective, population-based cohort study that included children and adolescents with acute myeloid leukemia diagnosed and treated at 15 Canadian centers. We evaluated infections that occurred between presentation to the healthcare system (for symptoms that led to the diagnosis of acute myeloid leukemia) until initiation of chemotherapy.Results:Among 328 children, 92 (28.0%) were neutropenic at presentation. Eleven (3.4%) had sterile-site microbiologically documented infection and four had bacteremia (only one Gram negative). Infection rate was not influenced by neutropenia. No child died from an infectious cause prior to chemotherapy initiation.Conclusion:It may be reasonable to withhold empiric antibiotics in febrile non-neutropenic children with newly diagnosed acute myeloid leukemia until initiation of chemotherapy as long as they appear well without a clinical focus of infection. Future work could examine biomarkers or a clinical score to identify children presenting with leukemia and fever who are more likely to have an invasive infection. © 2013 Portwine et al

    Impact of registration on clinical trials on infection risk in pediatric acute myeloid leukemia

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    Little is known about the impact of enrollment on therapeutic clinical trials on adverse event rates. Primary objective was to describe the impact of clinical trial registration on sterile site microbiologically documented infection for children with newly diagnosed acute myeloid leukemia (AML). We conducted a multicenter cohort study that included children aged ≤18 years with de novo AML. Primary outcome was microbiologically documented sterile site infection. Infection rates were compared between those registered and not registered on clinical trials. Five hundred seventy-four children with AML were included of which 198 (34.5%) were registered on a therapeutic clinical trial. Overall, 400 (69.7%) had at least one sterile site microbiologically documented infection. In multiple regression, registration on clinical trials was independently associated with a higher risk of microbiologically documented sterile site infection [adjusted odds ratio (OR) 1.24, 95% confidence interval (CI) 1.01-1.53; p = 0.040] and viridans group streptococcal infection (OR 1.46, 95% CI 1.08-1.98; p = 0.015). Registration on trials was not associated with Gram-negative or invasive fungal infections. Children with newly diagnosed AML enrolled on clinical trials have a higher risk of microbiologically documented sterile site infection. This information may impact on supportive care practices in pediatric AML

    Association between corticosteroids and infection, sepsis, and infectious death in pediatric acute myeloid leukemia (AML): Results from the Canadian infections in AML research group

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    Background. Infection continues to be a major problem for children with acute myeloid leukemia (AML). Objectives were to identify factors associated with infection, sepsis, and infectious deaths in children with newly diagnosed AML.Methods. We conducted a retrospective, population-based cohort study that included children ≤18 years of age with de novo, non-M3 AML diagnosed between January 1995 and December 2004, treated at 15 Canadian centers. Patients were monitored for infection from initiation of AML treatment until recovery from the last cycle of chemotherapy, conditioning for hematopoietic stem cell transplantation, relapse, persistent disease, or death (whichever occurred first). Consistent trained research associates abstracted all information from each site.Results. 341 patients were included. Median age was 7.1 years (interquartile range [IQR], 2.0-13.5) and 29 (8.5%) had Down syndrome. In sum, 26 (7.6%) experienced death as a first event. There were 1277 courses of chemotherapy administered in which sterile site microbiologically documented infection occurred in 313 courses (24.5%). Sepsis and infectious death occurred in 97 (7.6%) and 16 (1.3%) courses, respectively. The median days of corticosteroid administration was 2 per course (IQR, 0-6). In multiple regression analysis, duration of corticosteroid exposure was significantly associated with more microbiologically documented sterile site infection, bacteremia, fungal infection, and sepsis. The only factor significantly associated with infectious death was days of corticosteroid exposure (odds ratio, 1.05; 95% confidence interval, 1.02-1.08; P =. 001).Conclusions. In pediatric AML, infection, sepsis, and infectious death were associated with duration of corticosteroid exposure. Corticosteroids should be avoided when possible for this population. © The Author 2012. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved

    Infections in children with down syndrome and acute myeloid leukemia: A report from the Canadian infections in AML research group

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    Background: Children with Down syndrome (DS) are at high risk of infectious toxicity when treated with acute lymphoblastic leukemia chemotherapy protocols optimized in children without DS. Our objective was to determine if children with DS and acute myeloid leukemia (AML) have a different risk of infection when treated with chemotherapy protocols developed for children with DS compared to AML treatment protocols developed for children without DS. Methods. We conducted a retrospective, population-based cohort study that included DS children ≤ 18 years of age with de novo, non-M3 AML diagnosed between January 1995 and December 2004, and treated at 15 Canadian centers. Patients were monitored for infection from initiation of AML treatment until recovery from the last cycle of chemotherapy, conditioning for hematopoietic stem cell transplantation, relapse, persistent disease or death (whichever occurred first). Trained research associates abstracted all information from each site. Results: There were 31 children with DS included; median age was 1.7 (range 0.1-11.1) years. Eleven were treated according to a DS-specific protocol while 20 were treated with non-DS specific protocols. A total of 157 courses of chemotherapy were delivered. Microbiologically documented sterile site infection occurred in 11.9% and 14.3% of DS-specific and non-DS specific AML treatment courses respectively. Sepsis was rare and there were no infection-related deaths. In multiple regression, treatment with a DS-specific protocol was independently associated with a reduction in microbiologically documented sterile site infection (adjusted odds ratio (OR) 0.65, 95% confidence interval (CI) 0.42-0.99; P = 0.044), and clinically documented infection (adjusted OR 0.36, 95% CI 0.14-0.91; P = 0.031) but not bacteremia (adjusted OR 0.73, 95% CI 0.44-1.22; P = 0.231). Conclusions: Our study suggests that children with DS do not experience excessive infectious toxicity during treatment for AML compared to children without DS. Incorporation of DS-specific AML treatment protocols is associated with a more favorable infection profile for children with DS-AML. © 2013 Tran et al.; licensee BioMed Central Ltd

    Wild Bird Influenza Survey, Canada, 2005

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    Of 4,268 wild ducks sampled in Canada in 2005, real-time reverse transcriptase–PCR detected influenza A matrix protein (M1) gene sequence in 37% and H5 gene sequence in 5%. Mallards accounted for 61% of samples, 73% of M1-positive ducks, and 90% of H5-positive ducks. Ducks hatched in 2005 accounted for 80% of the sample

    The positive transcriptional elongation factor (P-TEFb) is required for neural crest specification

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    Regulation of gene expression at the level of transcriptional elongation has been shown to be important in stem cells and tumour cells, but its role in the whole animal is only now being fully explored. Neural crest cells (NCCs) are a multipotent population of cells that migrate during early development from the dorsal neural tube throughout the embryo where they differentiate into a variety of cell types including pigment cells, cranio-facial skeleton and sensory neurons. Specification of NCCs is both spatially and temporally regulated during embryonic development. Here we show that components of the transcriptional elongation regulatory machinery, CDK9 and CYCLINT1 of the P-TEFb complex, are required to regulate neural crest specification. In particular, we show that expression of the proto-oncogene c-Myc and c-Myc responsive genes are affected. Our data suggest that P-TEFb is crucial to drive expression of c-Myc, which acts as a ‘gate-keeper’ for the correct temporal and spatial development of the neural crest

    Visible lesbians and invisible bisexuals: Appearance and visual identities among bisexual women

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    A number of feminist scholars have argued that dress and appearance can be used to critique the dominant culture and explore alternative subjectivities. Research on non-heterosexual visual identities has explored the role that appearance and clothing practices can play in the construction of individual identities and collective communities. However, bisexual women are largely invisible in these discussions. The minimal existing research suggests that bisexual women are unable to communicate their sexuality through their clothing and appearance. This study explored how bisexual women manage their bodies and appearance in relation to their bisexuality. Qualitative interviews were conducted with 20 self-identified bisexual women and the data were analysed using thematic analysis. The participants reported particular visual aesthetics associated with an embodied lesbian identity; however, they reported no visual image of bisexual women. Nonetheless, despite their lack of access to a distinct visual identity, the women negotiated ways in which to incorporate their bisexual identity into their dress and appearance, and considered their bisexuality an important aspect of their identity, which they would like to be recognised and acknowledged

    Novel Avian Influenza H7N3 Strain Outbreak, British Columbia

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    Genome sequences of chicken (low pathogenic avian influenza [LPAI] and highly pathogenic avian influenza [HPAI]) and human isolates from a 2004 outbreak of H7N3 avian influenza in Canada showed a novel insertion in the HA0 cleavage site of the human and HPAI isolate. This insertion likely occurred by recombination between the hemagglutination and matrix genes in the LPAI virus
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