349 research outputs found

    Phosphorus Cycling in the Sargasso Sea: Investigation Using the Oxygen Isotopic Composition of Phosphate, Enzyme-Labeled Fluorescence, and Turnover Times

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    Dissolved inorganic phosphorus (DIP) concentrations in surface water of vast areas of the ocean are extremely low (\u3c10 nM) and phosphorus (P) availability could limit primary productivity in these regions. We explore the use of oxygen isotopic signature of dissolved phosphate (ή18OPO4) to investigate biogeochemical cycling of P in the Sargasso Sea, Atlantic Ocean. Additional techniques for studying P dynamics including 33P-based DIP turnover time estimates and percent of cells expressing alkaline phosphatase (AP) activity as measured by enzyme-labeling fluorescence are also used. In surface waters, ή18OPO4 values were lower than equilibrium by 3–6%, indicative of dissolved organic phosphorous (DOP) remineralization by extracellular enzymes. An isotope mass balance model using a variety of possible combinations of enzymatic pathways and substrates indicates that DOP remineralization in the euphotic zone can account for a large proportion on P utilized by phytoplankton (as much as 82%). Relatively short DIP turnover times (4–8 h) and high expression of AP (38–77% of the cells labeled) are consistent with extensive DOP utilization and low DIP availability in the euphotic zone. In deep water where DOP utilization rates are lower, ή18OPO4 values approach isotopic equilibrium and DIP turnover times are longer. Our data suggests that in the euphotic zone of the Sargasso Sea, DOP may be appreciably remineralized and utilized by phytoplankton and bacteria to supplement cellular requirements. A substantial fraction of photosynthesis in this region is supported by DOP uptake

    Sleep Hygiene and Problem Behaviors in Snoring and Non- Snoring School-Age Children

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    Objectives—The effects of sleep-disordered breathing, sleep restriction, dyssomnias, and parasomnias on daytime behavior in children have been previously assessed. However, the potential relationship(s) between sleep hygiene and children’s daytime behavior remain to be explored. The primary goal of this study was to investigate the relationship between sleep hygiene and problematic behaviors in non-snoring and habitually snoring children. Methods—Parents of 100 5- to 8-year-old children who were reported to snore “frequently” to “almost always,” and of 71 age-, gender-, and ethnicity-matched children who were reported to never snore participated in this study. As part of a larger, ongoing study, children underwent nocturnal polysomnography and parents were asked to complete the Children’s Sleep Hygiene Scale (CSHS) and the Conners’ Parent Rating Scales-Revised (CPRS-R:L). Results—In the snoring group, strong negative correlations (r = −.39, p Conclusions—Parental reports of behavioral patterns in snoring children indicate that poorer sleep hygiene is more likely to be associated with behavior problems, including hyperactivity, impulsivity, and oppositional behavior. In contrast, no significant relationships between slee

    2001 Wild Blueberry CSREES Project Reports

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    The 2001 edition of the Wild Blueberry CSREES Progress Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Effect of Wild Blueberry Products on Oxidation in Meat Based Food Systems 2. Factors Affecting the Microbial and Pesticide Residues Levels on Wild Blueberries 3. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries 4. Separation of Maggot-Infested Wild Blueberries in the IQF Processing Line 5. Water Use of Wild Blueberries and the Impact of Plant Water Stress on Yields 6. Survey of Stem Blight and Leaf Spot Diseases in Wild Blueberry Fields 7. IPM Strategies 8. Control Tactics for Wild Blueberry Pest Insects, 2001 9. Biology and Ecology of Blueberry Pest Insects 10. Diurnal Bee Activity and Measurement of Honeybee Field Strength 11. Effect of Foliar-applied Iron (Fe) Chelate Concentration on Leaf Iron Concentration, Wild Blueberry Growth and Yield 12. Effect of Boron Application Methods on Boron Uptake in Wild Blueberries 13. Effect of Foliar Iron and Copper Application on Growth and Yield of Wild Blueberries 14. Effect of Fertilizer Timing on Wild Blueberry Growth and Productivity 15. Effect of Foliar Copper Application on Growth and Yield of Wild Blueberries 16. Effect of Prune-year Applications of Nutri-Phitetm P or Nutri-Phitetm P+K on Growth and Yield of Wild Blueberry (Vaccinium angustifolium Ait.) 17. Effect of Soil pH on Nutrient Uptake 18. Assessment of Azafenidin for Weed Control in Wild Blueberries 19. Assessment of Rimsulfuron for Weed Control in Wild Blueberries 20. Assessment of Pendimethalin for Weed Control in Wild Blueberries 21. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields 22. Assessment of Sprout-less Weeder for Hardwood Control in Wild Blueberries 23. Wild Blueberry Extension Education Program in 2001 24. Evaluation of Fungicide Efficacy in Wild Blueberry Fields 25. 2001 Pesticide Groundwater Survey 26. Cultural Weed Management Using Sulfur to Lower the pH 27. Wild Blueberry Web Sit

    Cost effectiveness of first-line oral therapies for pulmonary arterial hypertension: A modelling study

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    Background: In recent years, a significant number of costly oral therapies have become available for the treatment of pulmonary arterial hypertension (PAH). Funding decisions for these therapies requires weighing up their effectiveness and costs. Objective: The aim of this study was to assess the cost effectiveness of monotherapy with oral PAH-specific therapies versus supportive care as initial therapy for patients with functional class (FC) II and III PAH in Canada. Methods: A cost-utility analysis, from the perspective of a healthcare system and based on a Markov model, was designed to estimate the costs and quality-adjusted life-years (QALYs) associated with bosentan, ambrisentan, riociguat, tadalafil, sildenafil and supportive care for PAH in treatment-naĂŻve patients. Separate analyses were conducted for cohorts of patients commencing therapy at FC II and III PAH. Transition probabilities, based on the relative risk of improving and worsening in FC with treatment versus placebo, were derived from a recent network meta-analysis. Utility values and costs were obtained from published data and clinical expert opinion. Extensive sensitivity analyses were conducted. Results: Analysis suggests that sildenafil is the most cost-effective therapy for PAH in patients with FC II or III. Sildenafil was both the least costly and most effective therapy, thereby dominating all other treatments. Tadalafil was also less costly and more effective than supportive care in FC II and III; however, sildenafil was dominant over tadalafil. Even given the uncertainty within the clinical inputs, the probabilistic sensitivity analysis showed that apart from sildenafil and tadalafil, the other PAH therapies had negligible probability of being the most cost effective. Conclusion: The results show that initiation of therapy with sildenafil is likely the most cost-effective strategy in PAH patients with either FC II or III disease.This research was supported by funds from the Canadian Agency for Drugs and Technologies in Health (CADTH)

    The \u27Healthy Parks-Healthy People\u27 Movement in Canada: Progress, Challenges, and an Emerging Knowledge and Action Agenda

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    In this article, we outline progress and challenges in establishing effective health promotion tied to visitor experiences provided by protected and conserved areas in Canada. Despite an expanding global evidence base, case studies focused on aspects of health and well-being within Canada’s protected and conserved areas remain limited. Data pertaining to motivations, barriers and experiences of visitors are often not collected by governing agencies and, if collected, are not made generally available or reported on. There is an obvious, large gap in research and action focused on the needs and rights of groups facing systemic barriers related to a variety of issues including, but not limited to, access, nature experiences, and needs with respect to health and well-being outcomes. Activation of programmes at the site level continue to grow, and Park Prescription programmes, as well as changes to the Accessible Canada Act, represent significant, positive examples of recent cross-sector policy integration. Evaluations of outcomes associated with HPHP programmes have not yet occurred but will be important to adapting interventions and informing cross-sector capacity building. We conclude by providing an overview of gaps in evidence and practice that, if addressed, can lead to more effective human health promotion vis-à-vis nature contact in protected and conserved areas in Canada

    Relational aggression in adolescents with conduct disorder:sex differences and behavioral correlates

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    As most research on conduct disorder (CD) has been conducted on male participants, it has been suggested that female-specific symptoms may be underestimated based on current DSM-5 criteria. In particular, relational aggression, i.e. the hurtful, often indirect, manipulation of relationships with the intention of damaging the other’s social position, has been proposed as a characteristic of CD that is more common in females. In addition, sex-specific studies on correlates of relational aggressive behavior are lacking. Relational aggression may be strongly related to the correlates of proactive aggression, namely low affective empathy, and high levels of callous-unemotional (CU) traits and relational victimization. Thus, the present study investigated sex differences in relational aggression, and associations between relational aggression and correlates of proactive aggression in 662 adolescents with CD (403 females) and 849 typically-developing controls (568 females) aged 9–18 years (M = 14.74, SD = 2.34) from the European multi-site FemNAT-CD study. Females with CD showed significantly higher levels of relational aggression compared to males with CD, whereas no sex differences were seen in controls. Relational aggression was only partly related to correlates of proactive aggression in CD: Independent of sex, CU traits showed a positive association with relational aggression. In females only, cognitive, but not affective empathy, was negatively associated with relational aggression. Relational victimization was more strongly associated with relational aggression in males compared to females. Despite interesting sex specific correlates of relational aggression, effects are small and the potential clinical implications should be investigated in future studies

    Telomere length analysis in amyotrophic lateral sclerosis using large-scale whole genome sequence data

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    BackgroundAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the loss of upper and lower motor neurons, leading to progressive weakness of voluntary muscles, with death following from neuromuscular respiratory failure, typically within 3 to 5 years. There is a strong genetic contribution to ALS risk. In 10% or more, a family history of ALS or frontotemporal dementia is obtained, and the Mendelian genes responsible for ALS in such families have now been identified in about 50% of cases. Only about 14% of apparently sporadic ALS is explained by known genetic variation, suggesting that other forms of genetic variation are important. Telomeres maintain DNA integrity during cellular replication, differ between sexes, and shorten naturally with age. Sex and age are risk factors for ALS and we therefore investigated telomere length in ALS. MethodsSamples were from Project MinE, an international ALS whole genome sequencing consortium that includes phenotype data. For validation we used donated brain samples from motor cortex from people with ALS and controls. Ancestry and relatedness were evaluated by principal components analysis and relationship matrices of DNA microarray data. Whole genome sequence data were from Illumina HiSeq platforms and aligned using the Isaac pipeline. TelSeq was used to quantify telomere length using whole genome sequence data. We tested the association of telomere length with ALS and ALS survival using Cox regression. ResultsThere were 6,580 whole genome sequences, reducing to 6,195 samples (4,315 from people with ALS and 1,880 controls) after quality control, and 159 brain samples (106 ALS, 53 controls). Accounting for age and sex, there was a 20% (95% CI 14%, 25%) increase of telomere length in people with ALS compared to controls (p = 1.1 x 10(-12)), validated in the brain samples (p = 0.03). Those with shorter telomeres had a 10% increase in median survival (p = 5.0x10(-7)). Although there was no difference in telomere length between sporadic ALS and familial ALS (p=0.64), telomere length in 334 people with ALS due to expanded C9orf72 repeats was shorter than in those without expanded C9orf72 repeats (p = 5.0x10(-4)). DiscussionAlthough telomeres shorten with age, longer telomeres are a risk factor for ALS and worsen prognosis. Longer telomeres are associated with ALS
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