Geographic information systems (GIS) are being used with increasing frequency in environmental epidemiology studies. Reported applications include locating the study population by geocoding addresses ...(assigning mapping coordinates), using proximity analysis of contaminant source as a surrogate for exposure, and integrating environmental monitoring data into the analysis of the health outcomes. Although most of these studies have been ecologic in design, some have used GIS in estimating environmental levels of a contaminant at the individual level and to design exposure metrics for use in epidemiologic studies. In this article we discuss fundamentals of three scientific disciplines instrumental to using GIS in exposure assessment for epidemiologic studies: geospatial science, environmental science, and epidemiology. We also explore how a GIS can be used to accomplish several steps in the exposure assessment process. These steps include defining the study population, identifying source and potential routes of exposure, estimating environmental levels of target contaminants, and estimating personal exposures. We present and discuss examples for the first three steps. We discuss potential use of GIS and global positioning systems (GPS) in the last step. On the basis of our findings, we conclude that the use of GIS in exposure assessment for environmental epidemiology studies is not only feasible but can enhance the understanding of the association between contaminants in our environment and disease.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background The poorer physical health of autistic adults compared to non-autistic adults has been highlighted by several epidemiological studies. However, research has so far been limited to specific ...geographical areas and has primarily focused on young autistic individuals (aged 35 years and younger). Recent studies indicate a higher rate of mortality in autistic people, as well as poorer quality of self-reported healthcare interactions. This study aims to determine, first, whether autistic people experience greater levels of non-communicable health conditions and second, whether these are explained by differences in demographics (i.e. sex, country of residence, ethnicity, education level), alcohol use, smoking, body mass index (BMI), or family history of medical conditions. Method We employed a cross-sectional, convenience-sampling study via an anonymous, online survey of autistic and non-autistic adults (n = 2305, mean age = 41.6, 65.9% female, 49% autistic). The survey asked participants to self-report information about their demographics, autism diagnosis, diet, exercise, sleep, sexual health, substance use, personal medical history, and family medical history (for all first-degree, biological relatives). Binomial logistic regression across four iterative models of increasing complexity was applied to assess rates of physical health conditions. The Benjamini-Hochberg correction was used to account for multiple testing, and only physical health conditions that achieved at least 1% endorsement within the overall sample (n > 22) were included in the analysis to reduce risk of Type I errors. We also used novel network analysis methods to test whether there are increased levels of multimorbidity between autistic and non-autistic people. Results There were significantly elevated rates of non-communicable conditions across all organ systems in autistic people, including gastrointestinal, neurological, endocrine, visual, ear/nose/throat, skin, liver and kidney, and haematological conditions. We confirmed previous findings by showing highly significant differences in rates of neurological and gastrointestinal symptoms (p < 0.0001). In addition, we established in the largest sample to date that Ehler-Danlos Syndrome (EDS) was more likely to occur among autistic females compared to non-autistic females. Finally, we found a higher prevalence of Coeliac's disease among autistic individuals compared to non-autistic individuals after controlling for sex, ethnicity, country of residence, alcohol use, smoking, and BMI, but these results became non-significant after accounting for family history. Limitations Our study is biased towards females, white individuals, highly educated people, and UK residents, likely due to sampling biases. Our self-report study design may also exclude those who lack access to computers, or those with intellectual disability. Our network analysis is also limited in size. Conclusions This study provides evidence of widespread, physical health comorbidity that spans nearly all major organ systems in autistic adults compared to non-autistic adults, using both binary logistic regression and network models. Healthcare professionals must be made aware of the range of co-occurring physical health conditions that may be more common among autistic people. However, our findings also point towards potential avenues requiring further exploration, such as the association of autism with both Coeliac's disease and EDS. Keywords: Autism, Physical health, Chronic illness, Ehlers-Danlos syndrome, Gastrointestinal condition, Neurological condition, Rheumatological condition
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
83.
Direct observation of vinyl hydroperoxide Liu, Fang; Fang, Yi; Kumar, Manoj ...
Physical chemistry chemical physics : PCCP,
08/2015, Volume:
17, Issue:
32
Journal Article
Peer reviewed
Many alkyl-substituted Criegee intermediates are predicted to undergo an intramolecular 1,4-hydrogen transfer to form isomeric vinyl hydroperoxide species (Cdouble bond, length as m-dashCOOH moiety), ...which break apart to release OH and vinoxy radicals. We report direct detection of stabilized vinyl hydroperoxides formed via carboxylic acid-catalyzed tautomerization of Criegee intermediates. A doubly hydrogen-bonded interaction between the Criegee intermediate and carboxylic acid facilitates efficient hydrogen transfer through a double hydrogen shift. Deuteration of formic or acetic acid permits migration of a D atom to yield partially deuterated vinyl hydroperoxides, which are distinguished from the CH3CHOO, (CH3)2COO, and CH3CH2CHOO Criegee intermediates by mass. Using 10.5 eV photoionization, three prototypical vinyl hydroperoxides, CH2double bond, length as m-dashCHOOD, CH2double bond, length as m-dashC(CH3)OOD, and CH3CHdouble bond, length as m-dashCHOOD, are detected directly. Complementary electronic structure calculations reveal several reaction pathways, including the barrierless acid-catalyzed tautomerization reaction predicted previously and a barrierless addition reaction that yields hydroperoxy alkyl formate.
The mechanical properties of four commercial β-titanium alloys (TIMETAL-LCB, Ti-15-3, β-21S, and VT22) were compared in the solution-treated-and-aged (STA) condition following thermomechanical ...processing comprising β solid solutioning, cold deformation (CD), continuous rapid heating, and final aging. The peak temperature during the rapid heating step was chosen to obtain either a recovered or recrystallized condition and thereby to control the distribution of residual deformation defects, which in turn influenced the size and distribution of α precipitates in the final microstructure. It was established that a good balance of high strength (in excess of 1600
MPa) and reasonable ductility could be obtained if a fine-grain microstructure with a β grain size of ∼10
μm was formed by recrystallization. The development of such a fine-grain size enabled a reduction in the aging temperature and thus increased the strength while maintaining ductility within the desired limits. In this respect, the properties could be varied to a great extent by varying the rate of heating to the aging temperature. On the other hand, aging of the recovered condition also led to a strength level of approximately 1600
MPa but with generally lower ductility than in the fine-grain, recrystallized condition. Another distinctive feature of the recovered condition was that the properties were relatively insensitive to the rate of heating to the aging temperature.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Epstein-Barr virus (EBV) is an oncogenic human herpesvirus infecting approximately 90% of the world's population. The oral cavity serves a central role in the life cycle, transmission, and ...pathogenesis of EBV. Transmitted to a new host via saliva, EBV circulates between cellular compartments within oral lymphoid tissues. Epithelial cells primarily support productive viral replication, while B lymphocytes support viral latency and reactivation. EBV infections are typically asymptomatic and benign; however, the latent virus is associated with multiple lymphomas and carcinomas arising in the oral cavity. EBV association with cancer is complex as histologically similar cancers often test negative for the virus. However, the presence of EBV is associated with distinct features in certain cancers. The intrinsic ability of EBV to immortalize B-lymphocytes, via manipulation of survival and growth signaling, further implicates the virus as an oncogenic cofactor. A distinct mutational profile and burden have been observed in EBV-positive compared to EBV-negative tumors, suggesting that viral infection can drive alternative pathways that converge on oncogenesis. Taken together, EBV is also an important prognostic biomarker that can direct alternative therapeutic approaches. Here, we discuss the prevalence of EBV in oral malignancies and the EBV-dependent mechanisms associated with tumorigenesis.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Mycobacterium tuberculosis, the causative agent of tuberculosis, still represents a major public health threat in many countries. Bioluminescence, the production of light by luciferase-catalyzed ...reactions, is a versatile reporter technology with multiple applications both in vitro and in vivo. In vivo bioluminescence imaging (BLI) represents one of its most outstanding uses by allowing the non-invasive localization of luciferase-expressing cells within a live animal. Despite the extensive use of luminescent reporters in mycobacteria, the resultant luminescent strains have not been fully applied to BLI.
One of the main obstacles to the use of bioluminescence for in vivo imaging is the achievement of reporter protein expression levels high enough to obtain a signal that can be detected externally. Therefore, as a first step in the application of this technology to the study of mycobacterial infection in vivo, we have optimised the use of firefly, Gaussia and bacterial luciferases in mycobacteria using a combination of vectors, promoters, and codon-optimised genes. We report for the first time the functional expression of the whole bacterial lux operon in Mycobacterium tuberculosis and M. smegmatis thus allowing the development of auto-luminescent mycobacteria. We demonstrate that the Gaussia luciferase is secreted from bacterial cells and that this secretion does not require a signal sequence. Finally we prove that the signal produced by recombinant mycobacteria expressing either the firefly or bacterial luciferases can be non-invasively detected in the lungs of infected mice by bioluminescence imaging.
While much work remains to be done, the finding that both firefly and bacterial luciferases can be detected non-invasively in live mice is an important first step to using these reporters to study the pathogenesis of M. tuberculosis and other mycobacterial species in vivo. Furthermore, the development of auto-luminescent mycobacteria has enormous ramifications for high throughput mycobacterial drug screening assays which are currently carried out either in a destructive manner using LuxAB or the firefly luciferase.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Density functional theory and transition state theory rate constant calculations have been performed to gain insight into the bimolecular reaction of the Criegee intermediate (CI) with carbon ...monoxide (CO) that is proposed to be important in both atmospheric and industrial chemistry. A new mechanism is suggested in which the CI acts as an oxidant by transferring an oxygen atom to the CO, resulting in the formation of a carbonyl compound (aldehyde or ketone depending upon the CI) and carbon dioxide. Fourteen different CIs, including ones resulting from biogenic ozonolysis, are considered. Consistent with previous reports for other CI bimolecular reactions, the anti conformers are found to react faster than the syn conformers. However, this can be attributed to steric effects and not hyperconjugation as generally invoked. The oxidation reaction is slow, with barrier heights between 6.3 and 14.7 kcal/mol and estimated reaction rate constants 6–12 orders-of-magnitude smaller than previously reported literature estimates. The reaction is thus expected to be unimportant in the context of tropospheric oxidation chemistry. However, the reaction mechanism suggests that CO could be exploited in ozonolysis to selectively obtain industrially important carbonyl compounds.
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IJS, KILJ, NUK, PNG, UL, UM
Carbon dioxide-expanded liquids, organic solvents with high concentrations of soluble carbon dioxide (CO2) at mild pressures, have gained attention as green catalytic media due to their improved ...properties over traditional solvents. More recently, carbon dioxide-expanded electrolytes (CXEs) have demonstrated improved reaction rates in the electrochemical reduction of CO2, by increasing the rate of delivery of CO2 to the electrode while maintaining facile charge transport. However, recent studies indicate that the limiting behavior of CXEs at higher CO2 pressures is a decline in solution conductivity due to reduced polarity, leading to poorer charge screening and greater ion pairing. In this article, we employ molecular dynamics simulations to investigate the energetic driving forces behind the diffusive properties of an acetonitrile and tetrapropylammonium hexafluorophosphate (TPrAPF6) CXE with increasing CO2 concentration. Our results indicate that entropy drives solvent and electrolyte diffusion with increasing CO2 pressure. The activation energy of ion diffusion increases with higher concentrations of CO2, indicating that increasing the temperature may improve solution conductivity in these systems. This trend in the activation energies is traced to stronger cation–anion Coulombic interactions due to weaker solvent screening at high CO2 concentrations, suggesting that the choice of ion may provide a route to diminish this effect.
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IJS, KILJ, NUK, PNG, UL, UM
Residential use of pesticides has been associated with increased risk of childhood acute lymphoblastic leukemia (ALL). We evaluated determinants of glyphosate concentrations in house dust and ...estimated ALL risk in the California Childhood Leukemia Study (CCLS).
The CCLS is a population-based case-control study of childhood leukemia in California. Among those < 8-years (no move since diagnosis/reference date), we collected dust (2001–2007) from the room where the child spent the most time while awake and measured > 40 pesticides. Three-to-eight years later, we collected a second sample from non-movers. We used Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry to measure glyphosate (µg/g dust) for 181 ALL cases and 225 controls and for 45 households with a second dust sample. We used multivariable Tobit regression to evaluate determinants of glyphosate concentrations. Odds ratios (ORs) and 95 % confidence intervals (CI) were calculated for ALL and quartiles of the concentration (first samples) using unconditional logistic regression. We computed the within- and between-home variance and intraclass correlation coefficient (ICC).
Glyphosate was frequently detected (cases: 98 %; controls: 99 %). Higher concentrations were associated with occupational pesticide exposure, nearby agricultural use, treatment for lawn weeds and bees/wasps, and sampling season. Increasing concentrations were not associated with ALL risk (adjusted ORQ4vsQ1 = 0.8, CI: 0.4–1.4). We observed similar null associations for boys and girls, Hispanics and non-Hispanic whites, and among those who resided in their home since birth (76 cases/117 controls) or age two (130 cases/176 controls). The ICC was 0.32 indicating high within-home temporal variability during the years of our study.
We observed higher concentrations in homes associated with expected predictors of exposure but no association with childhood ALL risk. Due to continuing use, potential exposure to young children is high. It will be important to evaluate risk in future studies with multiple dust measurements or biomarkers of exposure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This volume presents a critical analysis and timely synthesis of the past two decades of intensive research, development and demonstrations on the in situ remediation of chlorinated solvent plumes.
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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