297 research outputs found
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Organic carbon cycling in landfills: Model for a continuum approach
Organic carbon cycling in landfills can be addressed through a continuum model where the end-points are conventional anaerobic digestion of organic waste (short-term analogue) and geologic burial of organic material (long-term analogue). Major variables influencing status include moisture state, temperature, organic carbon loading, nutrient status, and isolation from the surrounding environment. Bioreactor landfills which are engineered for rapid decomposition approach (but cannot fully attain) the anaerobic digester end-point and incur higher unit costs because of their high degree of environmental isolation and control. At the other extreme, uncontrolled land disposal of organic waste materials is similar to geologic burial where organic carbon may be aerobically recycled to atmospheric CO{sub 2}, anaerobically converted to CH{sub 4} and CO{sub 2} during early diagenesis, or maintained as intermediate or recalcitrant forms into geologic time (> 1,000 years) for transformations via kerogen pathways. A family of improved landfill models are needed at several scales (molecular to landscape) which realistically address landfill processes and can be validated with field data
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Genetically modified food and consumer risk responsibility: The effect of regulatory design and risk type on cognitive information processing
Data Availability: All relevant data are within the paper and its Supporting Information files.Copyright: © 2021 Pakseresht et al. The use of agro-biotechnology has raised consumer concerns about environmental, health, socio-economic and ethical risks. This study examines how regulatory policies regarding genetically modified (GM) food production affect consumers' cognitive information processing, in terms of perceived risk, self-control, and risk responsibility. There is further analysis of whether the effect of policy design is moderated by risk type. Data was generated in a field experiment (n = 547), including four different policy scenario treatments (banned, research and development, import, and full commercialization). The results reveal that policy scenarios where GM food is available on the market are associated with higher levels of perceived risk and lower levels of self-control compared with policies where GM food is banned. There was no evidence of policy scenarios affecting consumer willingness to assign personal risk responsibility. However, among participants who indicated health risks as their main concern, there was an effect from the policy scenario on self-risk responsibility as mediated through perceived risk and self-control. The results suggest that healthconscious consumers tend to attribute less responsibility to themselves in situations where a genetically modified product was commercialized. These findings indicate a need to clarify guideline recommendations for health-related risks associated with foods derived from biotechnology.MISTRA Biotech on funds from the Swedish Foundation for Strategic Environmental Research (MISTRA), https://www.slu.se/mistrabiotech/en
Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance
Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O(3) exposure and swimming pool attendance. The measurements were made on 57 children 10–11 years of age before and after outdoor exercise for 2 hr. Individual O(3) exposure was estimated as the total exposure dose between 0700 hr until the second blood sample was obtained (mean O(3) concentration/m(3) × hours). The maximal 1-hr value was 118 μg/m(3) (59 ppb), and the individual exposure dose ranged between 352 and 914 μg/m(3)hr. These O(3) levels did not cause any significant changes in mean serum CC16 concentrations before or after outdoor exercise, nor was any decrease in lung function detected. However, children who regularly visited chlorinated indoor swimming pools had significantly lower CC16 levels in serum than did nonswimming children both before and after exercise (respectively, 57 ± 2.4 and 53 ± 1.7 μg/L vs. 8.2 ± 2.8 and 8.0 ± 2.6 μg/L; p < 0.002). These results indicate that repeated exposure to chlorination by-products in the air of indoor swimming pools has adverse effects on the Clara cell function in children. A possible relation between such damage to Clara cells and pulmonary morbidity (e.g., asthma) should be further investigated
A latent class analysis of food hygiene and handling practices among urban and peri-urban residents in Hyderabad, India
In developing countries, food-borne diseases, attributable to lack of, or inappropriate, food hygiene and handling
practices at home, are expected to increase due to a rapid growth in the consumption of fats and animal source
foods. The context-specific and situational practices corresponding to underlying traits of food hygiene and
handling practices for home-cooked food were investigated for a set of 662 randomly selected households in
Hyderabad, India. Results indicate that about one-third of the households lack access to a refrigerator. Of those
with a refrigerator, a majority (83%) had the temperature set at medium, with an actual temperature ranging
from 8 to 11 ◦C. Results also show that smell, followed by food appearance rather than taste or labelled expiry
dates were used as the main criteria for edibility. Furthermore, six indicators related to handling, storage and
cooking non-vegetarian food and three indicators related to storage of the cooked food were assessed. For
households with a refrigerator, the latent class analysis identified three exclusive and exhaustive subgroups of
households representing the heterogeneity of handling and hygiene traits, while two subgroups were identified
for households not having a refrigerator. Only a small proportion of households (12.6%) with a refrigerator were
profiled as having adequate and consistent practices. Remaining subgroups revealed substantial within-group
variations in terms of consistency in certain behaviors. Next, latent class modelling with covariates related to
socio-demographic, socio-economic, socio-spatial variables and health or dietary outcomes showed that having
higher than a primary school education, having a high percentage of food expenditure, or non-optimal refrigerator
temperature were predictive of the latent class with more adequate practices. For households without a
refrigerator, five covariates related to social class, age, income, and obesity distinguished the latent classes. These
findings of latent trait-specific behaviors have implications for actions aiming to inform and direct behavioral
change interventions on food safety practices in the developing countries
65 Cybele in the thermal infrared: Multiple observations and thermophysical analysis
We investigated the physical and thermal properties of 65 Cybele}, one of the
largest main-belt asteroids. Based on published and recently obtained thermal
infrared observations, including ISO measurements, we derived through
thermophysical modelling (TPM) a size of 302x290x232 km (+/- 4 %) and an
geometric visible albedo of 0.050+/-0.005. Our model of a regolith covered
surface with low thermal inertia and "default" roughness describes the
wavelengths and phase angle dependent thermal aspects very well. Before/after
opposition effect and beaming behaviour can be explained in that way. We found
a constant emissivity of 0.9 at wavelengths up to about 100 micron and lower
values towards the submillimetre range, indicating a grain size distribution
dominated by 200 micron particle sizes. The spectroscopic analysis revealed an
emissivity increase between 8.0 and 9.5 micron. We compared this emissivity
behaviour with the Christiansen features of carbonaceous chondrite meteorites,
but a conclusive identification was not possible. A comparison between the
Standard Thermal Model (STM) and the applied TPM clearly demonstrates the
limitations and problems of the STM for the analysis of multi-epoch and
-wavelengths observations. While the TPM produced a unique diameter/albedo
solution, the calculated STM values varied by +/-30 % and showed clear trends
with wavelength and phase angle. Cybele can be considered as a nice textbook
case for the thermophysical analysis of combined optical and thermal infrared
observations.Comment: 11 pages, 8 figures, accepted for publication by A&
Asteroid taxonomic signatures from photometric phase curves
We explore the correlation between an asteroid's taxonomy and photometric
phase curve using the H, G12 photometric phase function, with the shape of the
phase function described by the single parameter G12. We explore the usability
of G12 in taxonomic classification for individual objects, asteroid families,
and dynamical groups. We conclude that the mean values of G12 for the
considered taxonomic complexes are statistically different, and also discuss
the overall shape of the G12 distribution for each taxonomic complex. Based on
the values of G12 for about half a million asteroids, we compute the
probabilities of C, S, and X complex membership for each asteroid. For an
individual asteroid, these probabilities are rather evenly distributed over all
of the complexes, thus preventing meaningful classification. We then present
and discuss the G12 distributions for asteroid families, and predict the
taxonomic complex preponderance for asteroid families given the distribution of
G12 in each family. For certain asteroid families, the probabilistic prediction
of taxonomic complex preponderance can clearly be made. The Nysa-Polana family
shows two distinct regions in the proper element space with different G12
values dominating in each region. We conclude that the G12-based probabilistic
distribution of taxonomic complexes through the main belt agrees with the
general view of C complex asteroid proportion increasing towards the outer
belt. We conclude that the G12 photometric parameter cannot be used in
determining taxonomic complex for individual asteroids, but it can be utilized
in the statistical treatment of asteroid families and different regions of the
main asteroid belt.Comment: submitted to Icaru
Urban Sprawl and Adverse Impacts on Agricultural Land: A Case Study on Hyderabad, India
Many Indian capitals are rapidly becoming megacities due to industrialization and rural–urban emigration. Land use within city boundaries has changed dynamically, accommodating development while replacing traditional land-use patterns. Using Landsat-8 and IRS-P6 data, this study investigated land-use changes in urban and peri-urban Hyderabad and their influence on land-use and land-cover. Advanced methods, such as spectral matching techniques with ground information were deployed in the analysis. From 2005 to 2016, the wastewater-irrigated area adjacent to the Musi river increased from 15,553 to 20,573 hectares, with concurrent expansion of the city boundaries from 38,863 to 80,111 hectares. Opportunistic shifts in land-use, especially related to wastewater-irrigated agriculture, emerged in response to growing demand for fresh vegetables and urban livestock feed, and to easy access to markets due to the city’s expansion. Validation performed on the land-use maps developed revealed 80–85% accuracy
Physical properties of ESA Rosetta target asteroid (21) Lutetia: Shape and flyby geometry
Aims. We determine the physical properties (spin state and shape) of asteroid
(21) Lutetia, target of the ESA Rosetta mission, to help in preparing for
observations during the flyby on 2010 July 10 by predicting the orientation of
Lutetia as seen from Rosetta.
Methods. We use our novel KOALA inversion algorithm to determine the physical
properties of asteroids from a combination of optical lightcurves,
disk-resolved images, and stellar occultations, although the latter are not
available for (21) Lutetia.
Results. We find the spin axis of (21) Lutetia to lie within 5 degrees of
({\lambda} = 52 deg., {\beta} = -6 deg.) in Ecliptic J2000 reference frame
(equatorial {\alpha} = 52 deg., {\delta} = +12 deg.), and determine an improved
sidereal period of 8.168 270 \pm 0.000 001 h. This pole solution implies the
southern hemisphere of Lutetia will be in "seasonal" shadow at the time of the
flyby. The apparent cross-section of Lutetia is triangular as seen "pole-on"
and more rectangular as seen "equator-on". The best-fit model suggests the
presence of several concavities. The largest of these is close to the north
pole and may be associated with large impacts.Comment: 17 pages, 5 figures, 3 tables, submitted to Astronomy and
Astrophysic
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