1,604 research outputs found
Changes in metal biogeochemistry resulting from wetland creation: bioavailability, toxicity and risk "WETMAT": final report
In the vicinity of rivers, flooding of available lowlands can be considered as a possibility for temporal storage of river water during high water regimes to minimize the flooding danger of inhabited areas. The creation of wetlands for controlled flooding may also contribute to an increased ecological and biological value of the ecosystem area. Due to industrial activities, river water, sediments and soils are often contaminated with metals. The aim of this study was to determine the changes in the metal biogeochemistry under different hydrological conditions and in the presence of reed plants and how this affects the uptake of metals by plants and invertebrates. Two experimental setups were used. Lab scale experiments consisted of 42 barrels filled up with three different soils and flooded with water of different salinities. For the field scale experiment, 4 tanks filled with two soil types were placed on a platform in the river Scheldt and flooded daily by river water. Results showed that the metal mobility did not depend on the total metal content. Other factors such as soil pH, CEC, redox status and carbonate, OM and clay contents however play an important role in mediating metal behaviour. To prevent the mobilization of the metals, it is advisable to reduce redox variations in the soil. The two-year period of the experiment was too short to detect any measurable changes in most of the soil properties. The measured metal (im)mobilization kinetics can however already be incorporated in models in the near future. These models should allow to predict metal mobility changes at the oxic-anoxic interface upon changing hydrological conditions, where the already existing geochemical models fail due to the fact that they are based on steady state conditions. In the two-year experimental period, large quantities of metal contaminated sediment were found to be deposited on the soils of the tanks which were placed in the river Scheldt. This sedimentation could pose a problem, as it minimizes the water storage capacity of a flood control area. Moreover, the contamination status of alluvial soils should be used as a criterion when selecting new flood control areas as uncontaminated flood control areas are expected to be contaminated when polluted sediments originating from the surrounding surface waters are being deposited or when the soil is contacted with metal-polluted surface water. The latter can be expected in the future, as upon increasing oxygen contents of the river waters due to decreasing organic matter loads, metals can be mobilised from metal-polluted river sediments. Reduction of metal mobility upon increasing oxygen contents of river waters therefore needs further investigation. The metal accumulation in benthic organisms like T. tubifex was found to strongly depend on the inundation period. A higher Zn and Cu accumulation was recorded when substrates were allowed to oxidise. For the talitrid amphipod O. gammarellus, no clear influence was noted. Photosynthetic performance of the reed plants seemed to be mainly determined by other factors than merely metal contamination levels. There was however a possible relation between the abundance of stress enzymes and the metal contamination, making it a more valuable parameter to assess the effect of metals on reed plants in wetlands. The reed itself did not have any measurable effect on the concentration of the metals in the soil or pore water. Also no differences in the concentrations of metals in the reed biomass or differences in the reed growth were observed between the contaminated and uncontaminated soil
A proof-of-concept study evaluating the effect of ADX10059, a metabotropic glutamate receptor-5 negative allosteric modulator, on acid exposure and symptoms in gastro-oesophageal reflux disease
Ecosystem processes, land cover, climate, and human settlement shape dynamic distributions for golden eagle across the western US
Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates of occupancy were low (4.4–7.9%) and turnover rates – the probability that occupied sites were newly occupied – were high (88–94%), demonstrating that annual transiency in occupancy dominates late summer behavior for golden eagles. Despite low philopatry during late summer, variation in golden eagle occupancy could be explained by a suite of land cover and annual-varying covariates including gross primary productivity, drought severity, and human disturbance. Our summary of 13 years of predicted occupancy by golden eagles across the western United States identified areas that are consistently used and that may contribute significantly to golden eagle conservation. Restricting development and targeting mitigation efforts in these areas offers practitioners a framework for conservation prioritization
Development, implementation, and validation of a generic nutrient recovery model (NRM) library
The reported research developed a generic nutrient recovery model (NRM) library based on detailed chemical solution speciation and reaction kinetics, with focus on fertilizer quality and quantity as model outputs. Dynamic physicochemical three-phase process models for precipitation/crystallization, stripping and acidic air scrubbing as key unit processes were developed. In addition, a compatible biological-physicochemical anaerobic digester model was built. The latter includes sulfurgenesis, biological N/P/K/S release/uptake, interactions with organics, among other relevant processes, such as precipitation, ion pairing and liquid-gas transfer. Using a systematic database reduction procedure, a 3- to 5-fold improvement of model simulation speeds was obtained as compared to using full standard thermodynamic databases. Missing components and reactions in existing standard databases were discovered. Hence, a generic nutrient recovery database was created for future applications. The models were verified and validated against a range of experimental results. Their functionality in terms of increased process understanding and optimization was demonstrated
Development of type 1 diabetes in a patient treated with anti-TNF-α therapy for active rheumatoid arthritis
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Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study
DGBI; IBS; EpidemiologyDGBI; IBS; EpidemiologiaDGBI; IBS; EpidemiologĂaBackground & Aims
Although functional gastrointestinal disorders (FGIDs), now called disorders of gut-brain interaction, have major economic effects on health care systems and adversely affect quality of life, little is known about their global prevalence and distribution. We investigated the prevalence of and factors associated with 22 FGIDs, in 33 countries on 6 continents.
Methods
Data were collected via the Internet in 24 countries, personal interviews in 7 countries, and both in 2 countries, using the Rome IV diagnostic questionnaire, Rome III irritable bowel syndrome questions, and 80 items to identify variables associated with FGIDs. Data collection methods differed for Internet and household groups, so data analyses were conducted and reported separately.
Results
Among the 73,076 adult respondents (49.5% women), diagnostic criteria were met for at least 1 FGID by 40.3% persons who completed the Internet surveys (95% confidence interval [CI], 39.9–40.7) and 20.7% of persons who completed the household surveys (95% CI, 20.2–21.3). FGIDs were more prevalent among women than men, based on responses to the Internet survey (odds ratio, 1.7; 95% CI, 1.6–1.7) and household survey (odds ratio, 1.3; 95% CI, 1.3–1.4). FGIDs were associated with lower quality of life and more frequent doctor visits. Proportions of subjects with irritable bowel syndrome were lower when the Rome IV criteria were used, compared with the Rome III criteria, in the Internet survey (4.1% vs 10.1%) and household survey (1.5% vs 3.5%).
Conclusions
In a large-scale multinational study, we found that more than 40% of persons worldwide have FGIDs, which affect quality of life and health care use. Although the absolute prevalence was higher among Internet respondents, similar trends and relative distributions were found in people who completed Internet vs personal interviews.The study was funded, in part, by research grants from Ironwood, Shire, Allergan, and Takeda. The study in Malaysia was funded by the Fundamental Research Grant Scheme (FRGS) of the Ministry of Education of Malaysia (Reference: 203.PPSP.6171192). The study in Israel was funded by Takeda-Israel. The study in Romania was funded by the Romanian Society of Neurogastroenterology. None of the funders was involved in the planning, design, implementation, statistical analyses or any other aspect of the study including preparation of the paper or knowledge of its contents
Variation in nomenclature of somatic variants for selection of oncological therapies:Can we reach a consensus soon?
A standardized nomenclature for reporting oncology biomarker variants is key to avoid misinterpretation of results and unambiguous registration in clinical databases. External quality assessment (EQA) schemes have revealed a need for more consistent nomenclature use in clinical genetics. We evaluated the propensity of EQA for improvement of compliance with Human Genome Variation Society (HGVS) recommendations for reporting of predictive somatic variants in lung and colorectal cancer. Variant entries between 2012 and 2018 were collected from written reports and electronic results sheets. In total, 4,053 variants were assessed, of which 12.1% complied with HGVS recommendations. Compliance improved over time from 2.1% (2012) to 22.3% (2018), especially when laboratories participated in multiple EQA schemes. Compliance was better for next-generation sequencing (20.9%) compared with targeted techniques (9.8%). In the 1792 reports, HGVS recommendations for reference sequences were met for 31.9% of reports, for 36.0% of noncommercial, and 26.5% of commercial test methods. Compliance improved from 16.7% (2012) to 33.1% (2018), and after repeated EQA participation. EQA participation improves compliance with HGVS recommendations. The residual percentage of errors in the most recent schemes suggests that laboratories, companies, and EQA providers need to collaborate for additional improvement of harmonization in clinical test reporting
Delayed gastric emptying and reduced postprandial small bowel water content of equicaloric whole meal bread versus rice meals in healthy subjects: novel MRI insights
BACKGROUND/OBJECTIVES: Postprandial bloating is a common symptom in patients with functional gastrointestinal (GI) diseases. Whole meal bread (WMB) often aggravates such symptoms though the mechanisms are unclear. We used magnetic resonance imaging (MRI) to monitor the intragastric fate of a WMB meal (11% bran) compared to a rice pudding (RP) meal.
SUBJECTS/METHODS: 12 healthy volunteers completed this randomised crossover study. They fasted overnight and after an initial MRI scan consumed a glass of orange juice with a 2267 kJ WMB or an equicaloric RP meal. Subjects underwent serial MRI scans every 45 min up to 270 min to assess gastric volumes and small bowel water content and completed a GI symptom questionnaire.
RESULTS: The MRI intragastric appearance of the two meals was markedly different. The WMB meal formed a homogeneous dark bolus with brighter liquid signal surrounding it. The RP meal separated into an upper, liquid layer and a lower particulate layer allowing more rapid emptying of the liquid compared to solid phase (sieving). The WMB meal had longer gastric half emptying times (132±8 min) compared to the RP meal (104±7 min), P<0.008. The WMB meal was associated with markedly reduced MRI-visible small bowel free mobile water content compared to the RP meal, P<0.0001.
CONCLUSIONS: WMB bread forms a homogeneous bolus in the stomach which inhibits gastric sieving and hence empties slower than the equicaloric rice meal. These properties may explain why wheat causes postprandial bloating and could be exploited to design foods which prolong satiation
Application of a Near Infrared Imaging System for Thermographic Imaging of the Space Shuttle during Hypersonic Re-Entry
High resolution calibrated near infrared (NIR) imagery was obtained of the Space Shuttle s reentry during STS-119, STS-125, and STS-128 missions. The infrared imagery was collected using a US Navy NP-3D Orion aircraft using a long-range infrared optical package referred to as Cast Glance. The slant ranges between the Space Shuttle and Cast Glance were approximately 26-41 nautical miles at point of closest approach. The Hypersonic Thermodynamic Infrared Measurements (HYTHIRM) project was a NASA Langley led endeavor sponsored by the NASA Engineering Safety Center, the Space Shuttle Program Office and the NASA Aeronautics Research Mission Directorate to demonstrate a quantitative thermal imaging capability. HYTHIRM required several mission tools to acquire the imagery. These tools include pre-mission acquisition simulations of the Shuttle trajectory in relationship to the Cast Glance aircraft flight path, radiance modeling to predict the infrared response of the Shuttle, and post mission analysis tools to process the infrared imagery to quantitative temperature maps. The spatially resolved global thermal measurements made during the Shuttle s hypersonic reentry provides valuable flight data for reducing the uncertainty associated with present day ground-to-flight extrapolation techniques and current state-of-the-art empirical boundary-layer transition or turbulent heating prediction methods. Laminar and turbulent flight data is considered critical for the development of turbulence models supporting NASA s next-generation spacecraft. This paper will provide the motivation and details behind the use of an upgraded NIR imaging system used onboard a Navy Cast Glance aircraft and describe the characterizations and procedures performed to obtain quantitative temperature maps. A brief description and assessment will be provided of the previously used analog NIR camera along with image examples from Shuttle missions STS-121, STS-115, and solar tower test. These thermal observations confirmed the challenge of a long-range acquisition during re-entry. These challenges are due to unknown atmospheric conditions, image saturation, vibration etc. This provides the motivation for the use of a digital NIR sensor. The characterizations performed on the digital NIR sensor included radiometric, spatial, and spectral measurements using blackbody radiation sources and known targets. An assessment of the collected data for three Space Shuttle atmospheric re-entries, STS-119, STS-125, and STS-128, are provided along with a description of various events of interest captured using the digital NIR imaging system such as RCS firings and boundary layer transitions. Lastly the process used to convert the raw image counts to quantitative temperatures is presented along with comparisons to the Space Shuttle's onboard thermocouples
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