1,254 research outputs found
Simulation of changes in some soil properties as affected by water level fluctuation in an inland salt marsh
AbstractAn 87-day simulation experiment was conducted to test the effects of water level fluctuation on soil properties of an inland salt marsh. The simulated wetland was periodically flooded for 15 days with consistent water levels of 10cm above the wetland surface soil and then drained to 0cm for 9 days. Soil samples were collected from the 0 to 30cm depth with 10cm intervals at days of 0, 39 and 72 after a 15-day pre-incubation. Total nitrogen (TN), total phosphorus (TP), soil organic matter (SOM) and pH were determined during the experimental period. Results showed that TN content was much higher in surface soils than other soil layers during the whole incubation period, especially at the second inundation period (54 days), and TN greatly increased in the soil layers above 20cm with increasing incubation time. However, the SOM content in each soil layer showed a consistent tendency of âdecreasing followed increasingâ with increasing incubation time. Compared to other soil layers, SOM content in surface soils were generally higher during the simulation periods. TP content in upper soils (0-20cm) consistently increased over the course of incubation time, while those in deeper soils (20-30cm) decreased. Soil pH values showed similar changing tendencies to SOM content over the incubation experiment, while they generally increased with depth
Determining the upper limit of Gamma_{ee} for the Y(4260)
By fitting the R values between 3.7 and 5.0 GeV measured by the BES
collaboration, the upper limit of the electron width of the newly discovered
resonance Y(4260) is determined to be 580 eV at 90% C.L. Together with the
BABAR measurement on the product of Gamma_{ee} and BR(Y(4260) --> pi+pi-
J/psi), this implies a large decay width of Y(4260) --> pi+pi- J/psi final
states.Comment: 8 pages, 4 figure
Map- vs. homology-based cloning for the recessive gene ol-2 conferring resistance to tomato powdery mildew
The recessive gene ol-2 confers papilla-associated and race-non-specific resistance to tomato powdery mildew caused by Oidium neolycopersici. In order to facilitate marker assisted selection (MAS) in practical breeding programmes, we identified two simple sequence repeat (SSR) markers and one cleaved amplified polymorphic sequence (CAPS) marker which are linked to the resistance locus and co-dominantly inherited. Aiming to provide a base for ol-2 positional cloning, we used a large segregating F2 population to merge these markers with all the ol-2 linked amplified fragment length polymorphism (AFLPÂź) markers previously identified in an integrated genetic map. By screening a tomato bacterial artificial chromosome (BAC) library, we detected two BAC clones containing two expressed sequence tags (ESTs) homologous to the gene mlo, responsible for powdery mildew resistance in barley, as well as an ol-2-linked marker. Chromosomal mapping by Fluorescence in situ Hybridization (FISH) revealed major signals of the two BAC DNAs in the pericentromeric heterochromatin of the short arm of chromosome 4, in the same region where the ol-2 gene was previously mapped. The genetic and cytogenetic co-localisation between ol-2 and tomato mlo-homologue(s), in addition to the similarity of ol-2 and mlo resistances for both genetic and phytopathological characteristics, suggests that ol-2 is likely a mlo-homologue. Thus, a homology-based cloning approach could be more suitable than positional cloning for ol-2 isolation
Can the "brick wall" model present the same results in different coordinate representations?
By using the 't Hooft's "brick wall" model and the Pauli-Villars
regularization scheme we calculate the statistical-mechanical entropies arising
from the quantum scalar field in different coordinate settings, such as the
Painlev\'{e} and Lemaitre coordinates. At first glance, it seems that the
entropies would be different from that in the standard Schwarzschild coordinate
since the metrics in both the Painlev\'{e} and Lemaitre coordinates do not
possess the singularity at the event horizon as that in the Schwarzschild-like
coordinate. However, after an exact calculation we find that, up to the
subleading correction, the statistical-mechanical entropies in these
coordinates are equivalent to that in the Schwarzschild-like coordinate. The
result is not only valid for black holes and de Sitter spaces, but also for the
case that the quantum field exerts back reaction on the gravitational field
provided that the back reaction does not alter the symmetry of the spacetime.Comment: 8 pages, Phys. Rev. D in pres
Hadronic decay, the renormalization group, analiticity of the polarization operators and QCD parameters
The ALEPH data on hadronic tau-decay is throughly analysed in the framework
of QCD. The perturbative calculations are performed in 1-4-loop approximation.
The analytical properties of the polarization operators are used in the whole
complex q^2 plane. It is shown that the QCD prediction for R_{tau} agrees with
the measured value R_{tau} not only for conventional Lambda^{conv}_3 =
(618+-29) MeV but as well as for Lambda^{new}_3 = (1666+-7) MeV. The
polarization operator calculated using the renormgroup has nonphysical cut
[-Lambda^2_3, 0]. If Lambda_3 = Lambda^{conv}_3, the contribution of only
physical cut is deficient in the explanation of the ALEPH experiment. If
Lambda_3 = Lambda^{new}_3 the contribution of nonphysical cut is very small and
only the physical cut explains the ALEPH experiment. The new sum rules which
follow only from analytical properties of polarization operators are obtained.
Basing on the sum rules obtained, it is shown that there is an essential
disagreement between QCD perturbation theory and the tau-lepton hadronic decay
experiment at conventional value Lambda_3. In the evolution upwards to larger
energies the matching of r(q^2) (Eq.(12)) at the masses J/psi, Upsilon and 2m_t
was performed. The obtained value alpha_s(-m^2_z) = 0.141+-0.004 (at Lambda_3 =
Lambda^{new}_3) differs essentially from conventional value, but the
calculation of the values R(s) = sigma(e+e- -> hadrons)/sigma(e+e- -> mu+mu-),
R_l = Gamma(Z -> hadrons)/Gamma(Z -> leptons), alpha_s(-3 GeV^2), alpha_s(-2.5
GeV^2) does not contradict the experiments.Comment: 20 page
A Classification of Hyper-heuristic Approaches
The current state of the art in hyper-heuristic research comprises a set of approaches that share the common goal of automating the design and adaptation of heuristic methods to solve hard computational search problems. The main goal is to produce more generally applicable search methodologies. In this chapter we present and overview of previous categorisations of hyper-heuristics and provide a unified classification and definition which captures the work that is being undertaken in this field. We distinguish between two main hyper-heuristic categories: heuristic selection and heuristic generation. Some representative examples of each category are discussed in detail. Our goal is to both clarify the main features of existing techniques and to suggest new directions for hyper-heuristic research
Karonudib has potent anti-tumor effects in preclinical models of B-cell lymphoma
Chemo-immunotherapy has improved survival in B-cell lymphoma patients, but refractory/relapsed diseases still represent a major challenge, urging for development of new therapeutics. Karonudib (TH1579) was developed to inhibit MTH1, an enzyme preventing oxidized dNTP-incorporation in DNA. MTH1 is highly upregulated in tumor biopsies from patients with diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma, hence confirming a rationale for targeting MTH1. Here, we tested the efficacy of karonudib in vitro and in preclinical B-cell lymphoma models. Using a range of B-cell lymphoma cell lines, karonudib strongly reduced viability at concentrations well tolerated by activated normal B cells. In B-cell lymphoma cells, karonudib increased incorporation of 8-oxo-dGTP into DNA, and prominently induced prometaphase arrest and apoptosis due to failure in spindle assembly. MTH1 knockout cell lines were less sensitive to karonudib-induced apoptosis, but were displaying cell cycle arrest phenotype similar to the wild type cells, indicating a dual inhibitory role of the drug. Karonudib was highly potent as single agent in two different lymphoma xenograft models, including an ABC DLBCL patient derived xenograft, leading to prolonged survival and fully controlled tumor growth. Together, our preclinical findings provide a rationale for further clinical testing of karonudib in B-cell lymphoma
Global Systems Science and Policy
The vision of Global Systems Science (GSS) is to provide scientific evidence and means to engage into a reflective dialogue to support policy-making and public action and to enable civil society to collectively engage in societal action in response to global challenges like climate change, urbanisation, or social inclusion. GSS has four elements: policy and its implementation, the science of complex systems, policy informatics, and citizen engagement. It aims to give policy makers and citizens a better understanding of the possible behaviours of complex social systems. Policy informatics helps generate and evaluate policy options with computer-based tools and the abundance of data available today. The results they generate are made accessible to everybodyâpolicymakers, citizensâthrough intuitive user interfaces, animations, visual analytics, gaming, social media, and so on. Examples of Global Systems include epidemics, finance, cities, the Internet, trade systems and more. GSS addresses the question of policies having desirable outcomes, not necessarily optimal outcomes. The underpinning idea of GSS is not to precisely predict but to establish possible and desirable futures and their likelihood. Solving policy problems is a process, often needing the requirements, constraints, and lines of action to be revisited and modified, until the problem is âsatisficedâ, i.e. an acceptable compromise is found between competing objectives and constraints. Thus policy problems and their solutions coevolve much as in a design process. Policy and societal action is as much about attempts to understand objective facts as it is about the narratives that guide our actions. GSS tries to reconcile these apparently contradictory modes of operations. GSS thus provides policy makers and society guidance on their course of action rather than proposing (illusionary) optimal solutions
Measurements of psi(2S) decays to octet baryon-antibaryon pairs
With a sample of 14 million psi(2S) events collected by the BESII detector at
the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p
p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their
branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4,
(3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4,
respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter
alpha is determined to be 0.82+-0.17+-0.04.Comment: 8 pages, 8 figure
Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV
By analyzing the data sets of 17.3 pb taken at GeV
and 6.5 pb taken at GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 12 exclusive
light hadron final states produced in annihilation at the two energy
points. We have also set the upper limits on the observed cross sections and
the branching fractions for decay to these final states at 90%
C.L.Comment: 8 pages, 5 figur
- âŠ