7,427 research outputs found
Efficiency of different culture mediums and explant types of some Citrus rootstocks on somatic embryogenesis : [21]
Callus induction, somatic embryogenesis and plant regeneration were obtained in ten different Citrus genotypes [Citrus aurantium L. (cv 'Tuzcu 891 '), Citrus aurantium L. (cv 'Tuzcu 31-31'), Citrus aurantium L. (cv 'Gou Tou'), Citrus sinensis (L.) Osb. (cv 'Alanya Dilimli'), Citrus reshni Hort. ex.Tan. (cv 'Cyprus Cleopatra mandarine'), Poncirus trifoliata (L) Raf (cv 'Pomeroy'), Citrus sinensis (L) Osb. x Poncirus trifoliata (L) Raf. (cv 'Tuzcu M2 Citrange'), Citrus sinensis (L) Osb. x Poncirus trifoliata (L) Raf. (cv 'Carrizo Citrange'), Citrus paradisi Macf. x Poncirus trifoliata (L) Raf. (cv 'Swingle Citrumelo'), Citrus volkameriana Tan.& Pasg. (cv 'CRC 01 Volkameriana') from style and ovule explants. Explants were cultured on different culture media. The nutrients of Murashige and Skoog medium (MS) and Murashige and Tucker (MT) vitamins supplemented with 500 mg/l Malt Extract (ME), with 1 mg/l 2, 4-D and three different concentration of BA (0, 0.5, 1 mg/l) were used for first year experiments. MS basal medium was used alone with ME and three different concentration of BA (1, 2, 3 mg/l) for style explants for the second year experiment. MS nutrients and MT vitamins with ME were used alone and 2, 4-D (1 mg/l) and BA (0, 0.5, 1 mg/l) used for ovule culture experiment for the second year experiments. Sucrose was used as a carbon source (50 g/l) for all experirnents. The different genotypes showed different embryogenic frequency from style and ovule experiments. Percentages of style explants producing somatic embryos ranged from 0% (AREC Swingle Citrumelo, M2 Citrange, Volkameriana, Pomeroy trifoliate) to 100% (Gou Tou Sour Orange). Percentages of ovule explants producing somatic embryos ranged from 0% (Carrizo Citrange, Alanya Dilimli Sweet Orange, AREC Swingle Citrumelo) to 100% (Tuzcu 891 and Cleopatra Mandarine). About 4 weeks later somatic embryos developed into plantlets. Genetic stability of callus lines was determined by SSR markers. (Texte intégral
The Schrodinger equation with Hulthen potential plus ring-shaped potential
We present the solutions of the Schrdinger equation with the
Hulthn potential plus ring-shape potential for states
within the framework of an exponential approximation of the centrifugal
potential.Solutions to the corresponding angular and radial equations are
obtained in terms of special functions using the conventional Nikiforov-Uvarov
method. The normalization constant for the Hulthn potential is also
computed.Comment: Typed with LateX,12 Pages, Typos correcte
Traction force microscopy with optimized regularization and automated Bayesian parameter selection for comparing cells
Adherent cells exert traction forces on to their environment, which allows
them to migrate, to maintain tissue integrity, and to form complex
multicellular structures. This traction can be measured in a perturbation-free
manner with traction force microscopy (TFM). In TFM, traction is usually
calculated via the solution of a linear system, which is complicated by
undersampled input data, acquisition noise, and large condition numbers for
some methods. Therefore, standard TFM algorithms either employ data filtering
or regularization. However, these approaches require a manual selection of
filter- or regularization parameters and consequently exhibit a substantial
degree of subjectiveness. This shortcoming is particularly serious when cells
in different conditions are to be compared because optimal noise suppression
needs to be adapted for every situation, which invariably results in systematic
errors. Here, we systematically test the performance of new methods from
computer vision and Bayesian inference for solving the inverse problem in TFM.
We compare two classical schemes, L1- and L2-regularization, with three
previously untested schemes, namely Elastic Net regularization, Proximal
Gradient Lasso, and Proximal Gradient Elastic Net. Overall, we find that
Elastic Net regularization, which combines L1 and L2 regularization,
outperforms all other methods with regard to accuracy of traction
reconstruction. Next, we develop two methods, Bayesian L2 regularization and
Advanced Bayesian L2 regularization, for automatic, optimal L2 regularization.
Using artificial data and experimental data, we show that these methods enable
robust reconstruction of traction without requiring a difficult selection of
regularization parameters specifically for each data set. Thus, Bayesian
methods can mitigate the considerable uncertainty inherent in comparing
cellular traction forces
A note on q-Euler numbers and polynomials
The purpose of this paper is to construct q-Euler numbers and polynomials by
using p-adic q-integral equations on Zp. Finally, we will give some interesting
formulae related to these q-Euler numbers and polynomials.Comment: 6 page
Any l-state improved quasi-exact analytical solutions of the spatially dependent mass Klein-Gordon equation for the scalar and vector Hulthen potentials
We present a new approximation scheme for the centrifugal term to obtain a
quasi-exact analytical bound state solutions within the framework of the
position-dependent effective mass radial Klein-Gordon equation with the scalar
and vector Hulth\'{e}n potentials in any arbitrary dimension and orbital
angular momentum quantum numbers The Nikiforov-Uvarov (NU) method is used
in the calculations. The relativistic real energy levels and corresponding
eigenfunctions for the bound states with different screening parameters have
been given in a closed form. It is found that the solutions in the case of
constant mass and in the case of s-wave () are identical with the ones
obtained in literature.Comment: 25 pages, 1 figur
A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries.
BACKGROUND: Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey. METHODS AND FINDINGS: Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of 39,000,000 and 31674 LYG in Syria; 1,3000,000,000 and 378439 LYG in Turkey. CONCLUSION: Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives
Molecular analysis of the distribution and phylogeny of the soxB gene among sulfur-oxidizing bacteria - evolution of the Sox sulfur-oxidizing enzyme system
The soxB gene encodes the SoxB component of the periplasmic thiosulfate-oxidizing Sox enzyme complex, which has been proposed to be widespread among the various phylogenetic groups of sulfur-oxidizing bacteria (SOB) that convert thiosulfate to sulfate with and without the formation of sulfur globules as intermediate. Indeed, the comprehensive genetic and genomic analyses presented in the present study identified the soxB gene in 121 phylogenetically and physiologically divergent SOB, including several species for which thiosulfate utilization has not been reported yet. In first support of the previously postulated general involvement of components of the Sox enzyme complex in the thiosulfate oxidation process of sulfur-storing SOB, the soxB gene was detected in all investigated photo- and chemotrophic species that form sulfur globules during thiosulfate oxidation (Chromatiaceae, Chlorobiaceae, Ectothiorhodospiraceae, Thiothrix, Beggiatoa, Thiobacillus, invertebrate symbionts and free-living relatives). The SoxB phylogeny reflected the major 16S rRNA gene-based phylogenetic lineages of the investigated SOB, although topological discrepancies indicated several events of lateral soxB gene transfer among the SOB, e.g. its independent acquisition by the anaerobic anoxygenic phototrophic lineages from different chemotrophic donor lineages. A putative scenario for the proteobacterial origin and evolution of the Sox enzyme system in SOB is presented considering the phylogenetic, genomic (sox gene cluster composition) and geochemical data
Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.
Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells
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