319 research outputs found

    Lifelong exposure to air pollution and cognitive development in young children: the UK Millennium Cohort Study

    Get PDF
    Background. Evidence about the impact of air pollution on cognitive development of children has been growing but remains inconclusive. Objectives. To investigate the association of air pollution exposure and the cognitive development of children in the UK Millennium Cohort Study. Methods. Longitudinal study of a nationally representative sample of 13,058-14,614 singleton births, 2000-2002, analysed at age 3, 5 and 7 years for associations between exposure from birth to selected air pollutants and cognitive scores for: School Readiness, Naming Vocabulary (age 3 and 5), Picture Similarity, Pattern Construction (age 5 and 7), Number Skills and Word Reading. Multivariable regression models took account of design stratum, clustering and sampling and attrition weights with adjustment for major risk factors, including age, gender, ethnicity, region, household income, parents' education, language, siblings and second-hand tobacco smoke. Results: In fully adjusted models, no associations were observed between pollutant exposures and cognitive scores at age 3. At age 5, particulate matter (PM2.5, PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) were associated with lower scores for Naming Vocabulary but no other outcome except for SO2 and Picture Similarity. At age 7, PM2.5, PM10 and NO2 were associated with lower scores for Pattern Construction, SO2 with lower Number Skills and SO2 and ozone with poorer Word Reading scores, but PM2.5, PM10 and NO2 were associated with higher Word Reading scores. Adverse effects of air pollutants represented a deficit of up to around 4 percentile points in Naming Vocabulary at age 5 for an interquartile range increase in pollutant concentration, which is smaller than the impact of various social determinants of cognitive development. Conclusions: In a study of multiple pollutants and outcomes, we found mixed evidence from this UK-wide cohort study for association between lifetime exposure to neighbourhood air pollutants and cognitive development to age 7 years

    Detection of Endophyte Mycotoxins by Service Laboratories: Providing Answers for Safe Feed

    Get PDF
    . A global network of service laboratories exists to test livestock feed materials (typically grass hay and pellets) for ergovaline, ergot alkaloids and lolitrem B to ensure ‘safe feeds’ are being given to livestock. These compounds are mycotoxins produced by endophytic fungi that naturally reside in feed material. They have been purposely bred into grass species, as they enhance the plant’s survival from drought and insect predation. Unfortunately, ergovaline and other ergot alkaloids also cause vasoconstrictive effects and reproductive difficulties in livestock, resulting in a 1millionannuallossinproductionforthecattleindustryintheUSAalone.LolitremBisaneurotoxicantthatcausesasyndromeknownas‘ryegrassstaggers,’whichinvolvesatremoringresponseintheanimal.Clientsoftheseservicelaboratoriesincludehayfarmerswhowanttobeconfidentthattheproducttheyaresellingissafetofeedtolivestock;veterinarianswhoaretryingtoruleoutcausesofdiseaseinclinicalcases;individualswantingtocheckpersonalfeedsources;andresearchersinvestigatinginnovativesolutionstothesefeedcontaminants.Eachyear,approximately33,000containersofhayareshippedoverseasfromtheUSA,includingPacificRimandMiddleEasterncountries,bringinginanestimated1 million annual loss in production for the cattle industry in the USA alone. Lolitrem B is a neurotoxicant that causes a syndrome known as ‘ryegrass staggers,’ which involves a tremoring response in the animal. Clients of these service laboratories include hay farmers who want to be confident that the product they are selling is safe to feed to livestock; veterinarians who are trying to rule out causes of disease in clinical cases; individuals wanting to check personal feed sources; and researchers investigating innovative solutions to these feed contaminants. Each year, approximately 33,000 containers of hay are shipped overseas from the USA, including Pacific Rim and Middle Eastern countries, bringing in an estimated 130 million annually. If the importing country requires it, the material in these containers must be tested for the appropriate mycotoxin(s) and have a certificate stating that the level found was below the established threshold of toxicity. Discussion of sample submission, analysis and result receipt will be compared amongst international laboratories known to perform analyses for these mycotoxins

    Middleware for Internet of Things: A Survey

    Get PDF

    Frequency dispersion reduction and bond conversion on n-type GaAs by in situ surface oxide removal and passivation

    Get PDF
    The method of surface preparation on n-type GaAs, even with the presence of an amorphous-Si interfacial passivation layer, is shown to be a critical step in the removal of accumulation capacitance frequency dispersion. In situ deposition and analysis techniques were used to study different surface preparations, including NH4OH, Si-flux, and atomic hydrogen exposures, as well as Si passivation depositions prior to in situ atomic layer deposition of Al2O3. As–O bonding was removed and a bond conversion process with Si deposition is observed. The accumulation capacitance frequency dispersion was removed only when a Si interlayer and a specific surface clean were combined

    Assessing the Current and Future Risk of Overheating in London’s Care Homes: The Effect of Passive Ventilation

    Get PDF
    The warming climate causes adverse effects on thermal comfort and health, especially for vulnerable older adults. This study assesses the current and future risk of summertime overheating in London’s care homes and explores the potential of passive ventilation on reducing these risks. Analysis is based on temperature monitoring of two care settings and on thermal simulation models of future conditions with and without passive ventilation strategies. Results show high overheating exposures for both care homes, with temperatures averaging 31-35 0C by 2050. Passive ventilation can substantially reduce these exposures, but a successful approach depends on time of day, duration and window characteristics. Dynamic window opening based on lower outdoor temperatures and indoor temperature exceedance of 22 0C is the most beneficial approach for both settings now and in the future. The study demonstrates the effectiveness of affordable building adaptations for reducing heat stress in senior care homes

    GaAs interfacial self-cleaning by atomic layer deposition

    Get PDF
    The reduction and removal of surface oxides from GaAs substrates by atomic layer deposition (ALD) of Al2O3 and HfO2 are studied using in situ monochromatic x-ray photoelectron spectroscopy. Using the combination of in situ deposition and analysis techniques, the interfacial "self-cleaning" is shown to be oxidation state dependent as well as metal organic precursor dependent. Thermodynamics, charge balance, and oxygen coordination drive the removal of certain species of surface oxides while allowing others to remain. These factors suggest proper selection of surface treatments and ALD precursors can result in selective interfacial bonding arrangements

    Neurological Disorders and Publication Abstracts Follow Elements of Social Network Patterns when Indexed Using Ontology Tree-Based Key Term Search

    Get PDF
    Disorders of the Central Nervous System (CNS) are worldwide causes of morbidity and mortality. In order to further investigate the nature of the CNS research, we generate from an initial reference a controlled vocabulary of CNS disorder-related terms and ontological tree structure for this vocabulary, and then apply the vocabulary in an analysis of the past ten years of abstracts (N = 10,488) from a major neuroscience journal. Using literal search methodology with our terminology tree, we find over 5,200 relationships between abstracts and clinical diagnostic topics. After generating a network graph of these document-topic relationships, we find that this network graph contains characteristics of document-author and other human social networks, including evidence of scale-free and power law-like node distributions. However, we also found qualitative evidence for Z-normal-type (albeit logarithmically skewed) distributions within disorder popularity. Lastly, we discuss potential consumer-centered as well as clinic-centered uses for our ontology and search methodology

    Transition-Metal-Doping of CaO as Catalyst for the OCM Reaction, a Reality Check

    Get PDF
    In this study, first-row transition metal-doped calcium oxide materials (Mn, Ni, Cr, Co., and Zn) were synthesized, characterized, and tested for the OCM reaction. Doped carbonate precursors were prepared by a co-precipitation method. The synthesis parameters were optimized to yield materials with a pure calcite phase, which was verified by XRD. EPR measurements on the doped CaO materials indicate a successful substitution of Ca2+ with transition metal ions in the CaO lattice. The materials were tested for their performance in the OCM reaction, where a beneficial effect towards selectivity and activity effect could be observed for Mn, Ni, and Zn-doped samples, where the selectivity of Co- and Cr-doped CaO was strongly reduced. The optimum doping concentration could be identified in the range of 0.04-0.10 atom%, showing the strongest decrease in the apparent activation energy, as well as the maximum increase in selectivity
    • 

    corecore