447 research outputs found
Reactions of some grape cultivars to Dematophora necatrix
White root rot of grape caused by Dematophora necatrix is prevalent in Jahrom and Mimand of Fars province, Iran. In a greenhouse tests 30 gr of colonized wheat kernels per 1,200 g soil amended with peat moss were used to inoculate rooted cuttings of 29 Vitis vinifera and one hybrid cultivar in the pots. After 150 days most cuttings belonging to 27 V. vinifera cultivars and the hybrid died and were evaluated susceptible. However, 9 seedlings from 'Bidaneh Sephid Gazvin' and 3 from 'Bidaneh Ghermez Gazvin' remained alive. Roots of these cuttings were totally free from mycelium and looked healthy. The seedlings were transplanted after root disinfection with benomyl, in soil near Zarghan Vineyard Collection for further studies
Weyl holographic superconductor in the Lifshitz black hole background
We investigate analytically the properties of the Weyl holographic
superconductor in the Lifshitz black hole background. We find that the critical
temperature of the Weyl superconductor decreases with increasing Lifshitz
dynamical exponent, , indicating that condensation becomes difficult. In
addition, it is found that the critical temperature and condensation operator
could be affected by applying the Weyl coupling, . Moreover, we compute
the critical magnetic field and investigate its dependence on the parameters
and . Finally, we show numerically that the Weyl coupling parameter
and the Lifshitz dynamical exponent together control the size and
strength of the conductivity peak and the ratio of gap frequency over critical
temperature .Comment: 25 pages, 22 figure
Biopathologic Characterization of Three Mixed Poultry Eimeria spp. Isolates
Background: Coccidiosis of domestic fowl, caused by species of the Genus Eimeria, is responsible for important economic losses in poultry production. Because different species and/or strains can vary in pathogenicity and other biological parameters, their precise characterization is important for epizootiological studies.Methods: Fifty samples from litter, whole intestinal tract and feces were collected from poultry houses located in different provinces of Iran. One hundred twenty male day-old broiler chicks were challenged with three selected isolates. Data on weight gain, Food Conversion Ratio (FCR), food intake, lesion scoring and shedding of oocysts per gram of feces were recorded and analyzed by the Duncan's test.Results: In all treatments, the challenged groups had statistically significant lower weight gain than that of unchallenged control group. Isolate three caused the lowest weight gain and food intake and the worst lesion score as well as FCR. Despite originating from close geographical regions for isolates 1 and 2, the difference in biopathologic factors may be either due to different proportion of identified species or the different pathogenicity of the species present in the isolates.Conclusion: The results highlight the importance of considering various species of Eimeria in designing the preventive, control and treatment strategies to prevent coccidiosis in different regions of Iran. Further characterization of each isolate would be the next step to provide a basis for coccidiosis research with well-characterized local isolates
Equilibrium phase behavior of polydisperse hard spheres
We calculate the phase behavior of hard spheres with size polydispersity,
using accurate free energy expressions for the fluid and solid phases. Cloud
and shadow curves, which determine the onset of phase coexistence, are found
exactly by the moment free energy method, but we also compute the complete
phase diagram, taking full account of fractionation effects. In contrast to
earlier, simplified treatments we find no point of equal concentration between
fluid and solid or re-entrant melting at higher densities. Rather, the fluid
cloud curve continues to the largest polydispersity that we study (14%); from
the equilibrium phase behavior a terminal polydispersity can thus only be
defined for the solid, where we find it to be around 7%. At sufficiently large
polydispersity, fractionation into several solid phases can occur, consistent
with previous approximate calculations; we find in addition that coexistence of
several solids with a fluid phase is also possible
MiR-144: A new possible therapeutic target and diagnostic/prognostic tool in cancers
MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers
Convergent evolution of hetero‐oligomeric cellulose synthesis complexes in mosses and seed plants
In seed plants, cellulose is synthesized by rosette‐shaped cellulose synthesis complexes (CSCs) that are obligate hetero‐oligomeric, comprising three non‐interchangeable cellulose synthase (CESA) isoforms. The moss Physcomitrella patens has rosette CSCs and seven CESAs, but its common ancestor with seed plants had rosette CSCs and a single CESA gene. Therefore, if P. patens CSCs are hetero‐oligomeric, then CSCs of this type evolved convergently in mosses and seed plants. Previous gene knockout and promoter swap experiments showed that PpCESAs from class A (PpCESA3 and PpCESA8) and class B (PpCESA6 and PpCESA7) have non‐redundant functions in secondary cell wall cellulose deposition in leaf midribs, whereas the two members of each class are redundant. Based on these observations, we proposed the hypothesis that the secondary class A and class B PpCESAs associate to form hetero‐oligomeric CSCs. Here we show that transcription of secondary class A PpCESAs is reduced when secondary class B PpCESAs are knocked out and vice versa, as expected for genes encoding isoforms that occupy distinct positions within the same CSC. The class A and class B isoforms co‐accumulate in developing gametophores and co‐immunoprecipitate, suggesting that they interact to form a complex in planta. Finally, secondary PpCESAs interact with each other, whereas three of four fail to self‐interact when expressed in two different heterologous systems. These results are consistent with the hypothesis that obligate hetero‐oligomeric CSCs evolved independently in mosses and seed plants and we propose the constructive neutral evolution hypothesis as a plausible explanation for convergent evolution of hetero‐oligomeric CSCs
Variational Approach to Hard Sphere Segregation Under Gravity
It is demonstrated that the minimization of the free energy functional for
hard spheres and hard disks yields the result that excited granular materials
under gravity segregate not only in the widely known "Brazil nut" fashion, i.e.
with the larger particles rising to the top, but also in reverse "Brazil nut"
fashion. Specifically, the local density approximation is used to investigate
the crossover between the two types of segregation occurring in the liquid
state, and the results are found to agree qualitatively with previously
published results of simulation and of a simple model based on condensation.Comment: 10 pages, 3 figure
Polydisperse hard spheres at a hard wall
The structural properties of polydisperse hard spheres in the presence of a
hard wall are investigated via Monte Carlo simulation and density functional
theory (DFT). Attention is focussed on the local density distribution
, measuring the number density of particles of diameter
at a distance from the wall. The form of is
obtained for bulk volume fractions and for two
choices of the bulk parent distribution: a top-hat form, which we study for
degrees of polydispersity and , and a truncated
Schulz form having . Excellent overall agreement is found between
the DFT and simulation results, particularly at . A detailed
analysis of confirms the presence of oscillatory size
segregation effects observed in a previous DFT study (Pagonabarraga {\em et
al.}, Phys. Rev. Lett. {\bf 84}, 911 (2000)). For large , the character
of these oscillation is observed to depend strongly on the shape of the parent
distribution. In the vicinity of the wall, attractive -dependent
depletion interactions are found to greatly enhance the density of the largest
particles. The local degree of polydispersity is suppressed in this
region, while further from the wall it exhibits oscillations.Comment: 12 pages revte
Structure of ternary additive hard-sphere fluid mixtures
Monte Carlo simulations on the structural properties of ternary fluid
mixtures of additive hard spheres are reported. The results are compared with
those obtained from a recent analytical approximation [S. B. Yuste, A. Santos,
and M. Lopez de Haro, J. Chem. Phys. 108, 3683 (1998)] to the radial
distribution functions of hard-sphere mixtures and with the results derived
from the solution of the Ornstein-Zernike integral equation with both the
Martynov-Sarkisov and the Percus-Yevick closures. Very good agreement between
the results of the first two approaches and simulation is observed, with a
noticeable improvement over the Percus-Yevick predictions especially near
contact.Comment: 11 pages, including 8 figures; A minor change; accepted for
publication in PR
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