656 research outputs found
Strategic management of nitrogen within an organic cropping system using digestate from biogas production of recirculated crop residues
This project investigates strategic management of nitrogen by integrating crop residue management with biogas production. The approach offers potential for diversified farmer income, as food crops, feedstock for biogas and digestate for nutrient cycling are produced simultaneously. This type of diversification provides multifunctional solutions in organic farming, especially in production without access to animal manure. Biogas production from crop residues offers the possibility of reducing both emissions and leaching of nutrients to the surrounding ecosystems, as compared to the case where crop residue is incorporated into the soil for decomposition (Baggs et al. 2000; Velthof et al. 2002). This type of multifunctional cropping system provides solutions that can also help to solve issues on conventional farms, such as N emissions, and can also provide local production of biogas
"Stopping before you start" : reducing and preventing initiation of tobacco use in the ACT
Tobacco is the leading cause of preventable death in Australia and contributes to 5.4% of disease burden in the Australian Capital Territory. Initiation of tobacco use is most likely to occur during adolescence and young adulthood (at less than 20 years). Prevention of tobacco initiation involves a combination of regulatory, educational and health promotion interventions including restrictions on the sale of tobacco products. This paper reports on the development and use of an agent-based model to explore the impact of modifying three hypothetical regulatory and health promotion interventions: 1) increasing the minimum purchasing age for tobacco products, 2) reducing retail sales of tobacco products to persons under the minimum purchasing age and 3) reducing secondary sharing of tobacco products to persons under the minimum purchasing age using health promotion messaging. The model was built using a participatory approach that engaged policy officers, health promotion officers, epidemiologists, biostatisticians and computer scientists. The structure of the model included interacting state chart representations of smoking and level of concern about tobacco use (engagement status) and a pro-smoking score, which defined the hazard rate of initiation, cessation, and relapse. The pro-smoking score was a function of several risk factors including engagement, social effect of having more or fewer smoking peers, addiction and withdrawal levels and access to tobacco products. Parameterisation of the model drew on a range of data sources with local data being prioritised where it was available. A series of scenarios comparing the impact of the interventions on smoking prevalence rates and age of initiation are reported. Of the three interventions simulated, increasing the minimum purchasing age from 18 to 21 years had the greatest impact on smoking prevalence across the population, reducing the prevalence of smoking from 8.5% (95% CI 7.8, 9.2) to 6.9% (95% CI 6.4, 7.4) five years post-intervention and 4.1% (95% CI 3.8, 4.3) 20 years post intervention (Figure 1). The interventions aimed to reduce the sale of tobacco products to minors and reduce secondary sharing produced small reductions on their own. However, when implemented in combination with increasing the minimum purchasing age, they significantly increased the impact of this intervention from ten years post-implementation, ultimately resulting in a prevalence rate of 2.8% (95% CI 2.6, 3.0) 20 years post-implementation. Given the challenges associated with ceasing tobacco use, these in silico experiments demonstrate the importance of regulatory public health interventions to delay, and therefore potentially prevent initiation
Ensuring HLA-matched platelet support requires an ethnic diverse donor population
BACKGROUND: Patients refractory for platelet transfusions benefit from human leukocyte antigen (HLA)-matched platelet transfusions. Differences in ethnic background of patients and donors could hamper the availability of sufficient numbers of HLA-matched donors for all patients. We evaluated our HLA-matched donor program and explored the role of ethnic background of patients related to the number of available donors. METHODS: We performed a cohort study among consecutive patients who received HLA-matched platelet concentrates in the Netherlands between 1994 and 2017. The number of available matched donors was determined per patient. Haplotypes were constructed from genotypes with computer software (PyPop). Based on haplotypes, HaploStats, an algorithm from the National Marrow Donor Program, was used to assess the most likely ethnic background for patients with 5 or fewer and 30 or more donors. RESULTS: HLA typing was available for 19,478 donors in September 2017. A total of 1206 patients received 12,350 HLA-matched transfusions. A median of 83 (interquartile range, 18-266) donors were available per patient. For 95 (10.3%) patients, 5 or fewer donors were available. These patients were more likely to have an African American background, whereas patients with 30 or more donors were more often from Caucasian origin, compared with Caucasian origin for patients with 30 donors. CONCLUSION: Adequate transfusion support could be guaranteed for most but not all refractory patients. More non-Caucasian donors are required to ensure the availability of HLA-matched donors for all patients in the Netherlands
HLA-matched platelet transfusions are effective only in refractory patients with positive HLA antibody screening
BACKGROUND Recipients of platelet transfusions with 1-hour corrected count increments (1hCCIs) of 7.5 or less on two subsequent platelet transfusions with random platelets may benefit from human leukocyte antigen (HLA)-matched platelet concentrates. We aimed to quantify the efficacy of HLA-matched platelets concentrates expressed in 1hCCIs. METHODS We performed a cohort study among consecutive refractory patients who received HLA-matched platelet concentrates in the Netherlands between 1994 and 2017. We performed mixed-model linear regression comparing 1hCCIs after HLA split-antigen-matched transfusions with 1hCCIs after HLA-mismatched transfusions, adjusted for within-patient correlations. A donor-to-patient match was categorized as a split-match if all donor HLA-A and -B antigens were present in the patient as well; that is, donor and patient were HLA identical or compatible. Subgroup analyses were performed for patients with positive or negative HLA antibody screens. Finally, the additional effect of ABO mismatches on 1hCCIs was investigated. RESULTS The 1hCCI after an HLA-matched transfusion was 14.09 (95% reference interval, 1.13-29.89). This was 1.94 (95% confidence interval [CI], 0.74-3.15) higher than 1hCCI after HLA-mismatched transfusions. In patients with negative HLA antibody screening tests, HLA matching did not affect 1hCCIs. Conditional on HLA matching, 1hCCIs decreased by 3.70 (95% CI, -5.22 to -2.18) with major ABO mismatches. CONCLUSION Matched platelet concentrates yielded maximal 1hCCIs, whereas mismatched transfusions still resulted in adequate increments. There is no indication for HLA-matched platelets in patients with negative antibody screens
Outflows of very ionized gas in the center of Seyfert galaxies: kinematics and physical conditions
Mid-resolution spectra are used to deduce the size and kinematics of the
coronal gas in a sample of Seyfert galaxies by means of observations of the
[FeXI], [FeX], [FeVII], [SiVI] and [SiVII] lines. These coronal lines (CL)
extend from the unresolved nucleus up to a few tens to a few hundreds of
parsecs. The region of the highest ionized ions studied, [FeXI] and [FeX], is
the least spatially extended, and concentrates at the center; intermediate
ionization lines extend from the nucleus up to a few tens to a few hundred
parsecs; lower [OIII]-like ions are known to extendin the kpc range. All
together indicates a stratification in the ionized gas, usually interpreted in
terms of nuclear photoionization as the driving ionization mechanism. However,
CL profiles show various peculiarities: they are broader by a factor of two
than lower ionization lines, the broadening being in terms of asymmetric blue
wings, and their centroid position at the nucleus is blueshifted by a few
hundreds of km/s. Moreover, in NGC1386 and NGC1068, a double peak [FeVII] line
is detected in the nuclear and extended coronal region, this being the first
report in of such type of profile in CL in active galactic nuclei. If
interpreted as outflow signatures, the total broadening of the lines at zero
intensity levels implies gas velocities up to 2000 km/s. Although the
stratification of ions across the coronal region means that photoionization is
the main power mechanism, the high velocities deduced from the profiles, the
relatively large spatial extension of the emission, and the results from
photoionization models indicate that an additional mechanism is at work. We
suggest that shocks generated by the outflow could provide the additional
required power for line formation.Comment: Accepted for publication in the Astrophysical Journal. 40 pages, 15
figures. Minor changes made on the affiliation of one co-autho
Tests of the Equivalence Principle with Neutral Kaons
We test the Principle of Equivalence for particles and antiparticles, using
CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time,
we search for possible annual, monthly and diurnal modulations of the
observables |eta_{+-}| and phi_{+-}, that could be correlated with variations
in astrophysical potentials. Within the accuracy of CPLEAR, the measured values
of |eta_{+-}| and phi_{+-} are found not to be correlated with changes of the
gravitational potential. We analyze data assuming effective scalar, vector and
tensor interactions, and we conclude that the Principle of Equivalence between
particles and antiparticles holds to a level of 6.5, 4.3 and 1.8 x 10^{-9},
respectively, for scalar, vector and tensor potentials originating from the Sun
with a range much greater than the distance Earth-Sun. We also study
energy-dependent effects that might arise from vector or tensor interactions.
Finally, we compile upper limits on the gravitational coupling difference
between K0 and K0bar as a function of the scalar, vector and tensor interaction
range.Comment: 15 pages latex 2e, five figures, one style file (cernart.csl)
incorporate
Test of CPT Symmetry and Quantum Mechanics with Experimental data from CPLEAR
We use fits to recent published CPLEAR data on neutral kaon decays to
and to constrain the CPT--violation parameters
appearing in a formulation of the neutral kaon system as an open
quantum-mechanical system. The obtained upper limits of the CPT--violation
parameters are approaching the range suggested by certain ideas concerning
quantum gravity.Comment: 9 pages of uuencoded postscript (includes 3 figures
Platelet lysate-based pro-angiogenic nanocoatings
Human platelet lysate (PL) is a cost-effective and human source of autologous multiple and potent pro-angiogenic factors, such as vascular endothelial growth factor A (VEGF A), fibroblast growth factor b (FGF b) and angiopoietin-1. Nanocoatings previously characterized were prepared by layer-by-layer assembling incorporating PL with marine-origin polysaccharides and were shown to activate human umbilical vein endothelial cells (HUVECs). Within 20 h of incubation, the more sulfated coatings induced the HUVECS to the form tube-like structures accompanied by an increased expression of angiogenicassociated genes, such as angiopoietin-1 and VEGF A. This may be a cost-effective approach to modify 2D/3D constructs to instruct angiogenic cells towards the formation of neo-vascularization, driven by multiple and synergistic stimulations from the PL combined with sulfated polysaccharides.
Statement of Significance
The presence, or fast induction, of a stable and mature vasculature inside 3D constructs is crucial for new
tissue formation and its viability. This has been one of the major tissue engineering challenges, limiting the dimensions of efficient tissue constructs. Many approaches based on cells, growth factors, 3D bioprinting and channel incorporation have been proposed. Herein, we explored a versatile technique, layer-by-layer assembling in combination with platelet lysate (PL), that is a cost-effective source of many potent pro-angiogenic proteins and growth factors. Results suggest that the combination of PL with sulfated polyelectrolytes might be used to introduce interfaces onto 2D/3D constructs with potential to induce the formation of cell-based tubular structures.The research leading to these results has received funding from European Union's Seventh Framework Program (FP7/2007-2013) under grant agreement na REGPOT-CT2012-316331 - POLARIS and FP7-KBBE-2010-4-266033 - SPECIAL. This work was also supported by the European Research Council grant agreement ERC-2012-ADG-20120216-321266 for the project ComplexiTE. Portuguese Foundation for Science and Technology is gratefully acknowledged for fellowship of Sara M. Oliveira (SFRH/BD/70107/2010). The researcher contract of R.P. Pirraco through RL3-TECT-NORTE-01-0124-FEDER-000020, co-financed by North Portugal Regional Operational Program (ON.2-O Novo Norte), under the National Strategic Reference Framework, through the European Regional Development Fund is also acknowledged
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