160 research outputs found
Biopolymer additives for the reduction of soil erosion losses during irrigation
High molecular weight, synthetic polyacrylamides (PAM) are
relatively large, water soluble polymers that are used increasingly
by farmers to prevent erosion and increase infiltration during
irrigation. A lab-scale erosion test was conducted to screen
biopolymer solutions for a similar efficacy in reducing shear-induced
erosion. In lab-scale mini-furrow tests, chitosan, starch
xanthate, cellulose xanthate, and acid-hydrolyzed cellulose
microfibrils, at concentrations of 20, 80, 80, and 120 ppm
respectively, reduced suspended solids in the runoff water from test
soil. None of these biopolymers, however, exhibited the >90%
runoff sediment reduction shown by PAM at concentrations as low
as 5 ppm. Preliminary field tests results showed that chitosan
solutions were only marginally effective in reducing runoff from a
137m long furrow. There were indications that results were
dependent on the length of the furrow. Erosion of some clay-rich
soils from Northern California was reduced up to 85% by
increasing the concentration of exchangeable calcium to
>2.5mMole, with or without the addition of polymer additives
Physical activity, depressed mood and pregnancy worries in European obese pregnant women: Results from the DALI study
Background: The purpose of this study was to examine the association between mental health status (i.e. depressed mood and pregnancy-related worries) and objectively measured physical activity levels in obese pregnant women from seven European countries. Methods: Baseline data from the vitamin D and lifestyle intervention for the prevention of gestational diabetes mellitus (DALI) study were used. Time spent in moderate-to-vigorous physical activity (MVPA) and sedentary behaviour was measured with accelerometers. Depressed mood was measured with the WHO well-being index (WHO-5) and pregnancy-related worries with the Cambridge Worry Scale (CWS). In addition, socio-demographic characteristics, lifestyle factors, and perceptions and attitude regarding weight management and physical activity were measured. Linear regression analyses were performed to assess the association of mental health status with MVPA and sedentary behaviour. Results: A total of 98 obese pregnant women from Austria, Belgium, Ireland, Italy, Poland, Spain and the Netherlands were included. Women had a mean age of 31.6 ± 5.8 years, a pre-pregnancy BMI of 34.1 ± 4.3 kg/m2, and were on average 15.4 ± 2.8 weeks pregnant. WHO-5 scores indicative of depressed mood (\u3c50) were reported by 27.1 % of the women and most frequently endorsed pregnancy-related worries pertained to own and the baby\u27s health. Women with good well-being spent 85 % more time in MVPA compared to women with a depressed mood (P = 0.03). No differences in MVPA levels were found for women with no, some, or many pregnancy worries. Depressed mood and pregnancy-related worries were not associated with sedentary behaviour. Conclusions: These findings suggest that in pregnant women who are obese, a depressed mood, but not pregnancy-related worries, may be associated with less physical activity. The combined risk of poor mental health and low physical activity levels makes women vulnerable for pregnancy complications. Whether a depressed mood may be a barrier for improving physical activity warrants further study
Use of synthetic polymers and biopolymers for soil stabilization in agricultural, construction, and military applications
Three relatively new applications for controlling wind and water erosion using polyacrylamide copolymers arc described that
take advantage of their ability to stabilize and add structure to soil. In the first application, low concentrations of anionic, high purity
polyacrylamide (PAM) eliminates sediment in runoff water by more than 90% when added to irrigation water at 10 ppm, or at a rate of
1 to 2 kg ha-1 per irrigation. Lab-furrow tests were utilized to characterize the role of molecular weight. charge, and ion concentrations in
applying PAM during irrigation. In the second application, PAM is applied at construction sites and road cuts at rates of 22.5 kg ha -2
(tenfold higher rates than in irrigation control) resulting in reduction in sediment runoff by 60-85% during (simulated) heavy rains.
Finally, a formulation of PAM mixed with aluminum chlorohydrate and cross-linked poly(acrylic acid) superabsorbent at a ratio of (6:1:1)
has been applied to create helicopter landing pads that minimize dust clouds during helicopter operation. This formulation was specifically
developed to minimize dust clouds during landing of helicopters in fine, arid soils such as those potentially encountered in the Middle
East. A biodegradable alternative to PAM, acid-hydrolyzed cellulose microfibrils, was tested in lab-scale furrows and was less effective
than PAM at similar concentrations, but show promises. Microfibrils reduce sediment run-off in lab-furrow tests by 88% when applied at
eight- to tenfold the concentration of PAM
An acid-stable laccase from sclerotium rolfsii with potential for wool dye decolourization
The plant pathogen basidiomycete S. rolfsii secretes two laccases (SRL1 and SRL2) with molecular weights of 55 and 86 kDa, respectively.
Laccase production was shown to be inducible by the addition of 2,5-xylidine to the cultural media. After treatment with a combination
of chitinase and -1,3-glucanase, two different laccases were isolated from the sclerotia depending on the stage of sclerotia development.
The more prominent laccase, SRL1, was purified and found to decolourize the industrially important wool azo dye Diamond Black PV
200 without the addition of redox mediators. The enzyme (pI 5.2) was active in the acidic pH range, showing an optimal activity at pH
2.4, with ABTS as substrate. The optimum temperature for activity was determined to be 62 ◦C. Enzyme stability studies revealed that
SRL1 was notably stable at 18 ◦C and pH 4.5, retaining almost full activity after a week. Oxidation of tyrosine was not detectable under
the reaction conditions but the enzyme did oxidize a variety of the usual laccase substrates. SRL1 was strongly inhibited by sodium azide
and fluoride. Dye solutions decolourized with the immobilized laccase were successfully used for redyeing.(undefined
Late Winter Biogeochemical Conditions Under Sea Ice in the Canadian High Arctic
With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2) uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winter–spring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11′ N, 104° 47.44′ W) in the Canadian High Arctic. Results show relatively low surface water (1–10 m) nitrate (<1.3 µM) and total inorganic carbon concentrations (mean±SD=2015±5.83 µmol kg−1), total alkalinity (mean±SD=2134±11.09 µmol kg−1) and under-ice pCO2sw (mean±SD=286±17 µatm). These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season
Genetically Determined Height and Risk of Non-hodgkin Lymphoma
Although the evidence is not consistent, epidemiologic studies have suggested that taller adult height may be associated with an increased risk of some non-Hodgkin lymphoma (NHL) subtypes. Height is largely determined by genetic factors, but how these genetic factors may contribute to NHL risk is unknown. We investigated the relationship between genetic determinants of height and NHL risk using data from eight genome-wide association studies (GWAS) comprising 10,629 NHL cases, including 3,857 diffuse large B-cell lymphoma (DLBCL), 2,847 follicular lymphoma (FL), 3,100 chronic lymphocytic leukemia (CLL), and 825 marginal zone lymphoma (MZL) cases, and 9,505 controls of European ancestry. We evaluated genetically predicted height by constructing polygenic risk scores using 833 height-associated SNPs. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for association between genetically determined height and the risk of four NHL subtypes in each GWAS and then used fixed-effect meta-analysis to combine subtype results across studies. We found suggestive evidence between taller genetically determined height and increased CLL risk (OR = 1.08, 95% CI = 1.00\u20131.17, p = 0.049), which was slightly stronger among women (OR = 1.15, 95% CI: 1.01\u20131.31, p = 0.036). No significant associations were observed with DLBCL, FL, or MZL. Our findings suggest that there may be some shared genetic factors between CLL and height, but other endogenous or environmental factors may underlie reported epidemiologic height associations with other subtypes
Qualidade de caquis Fuyu tratados com cálcio em pré-colheita e armazenados sob atmosfera modificada
Transverse momentum spectra of charged particles in proton-proton collisions at GeV with ALICE at the LHC
The inclusive charged particle transverse momentum distribution is measured
in proton-proton collisions at GeV at the LHC using the ALICE
detector. The measurement is performed in the central pseudorapidity region
over the transverse momentum range GeV/.
The correlation between transverse momentum and particle multiplicity is also
studied. Results are presented for inelastic (INEL) and non-single-diffractive
(NSD) events. The average transverse momentum for is (stat.) (syst.) GeV/ and
\left_{\rm NSD}=0.489\pm0.001 (stat.) (syst.)
GeV/, respectively. The data exhibit a slightly larger than measurements in wider pseudorapidity intervals. The results are
compared to simulations with the Monte Carlo event generators PYTHIA and
PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/390
Contribuição ao protocolo de monitoramento ambiental da maricultura de Kappaphycus alvarezii (Doty) Doty ex P.C. Silva (Areschougiaceae - Rhodophyta) na baía de Sepetiba, RJ, Brasil
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