2006
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Uptake, Transport and Chelation of Cu and Zn at Toxic Levels in Tolerant and Sensitive Species from North West of Iran
https://jsciences.ut.ac.ir/article_31758.html
1
From flora of North West of Iran, four contrasting species in term of frequency and coverage on heavy metal rich soils were selected to study physiological mechanisms for different tolerance of Zn and Cu toxicity in a hydroponic culture experiment. For study of Zn toxicity, Dactylis glomerata and Secale monatum and for Cu, Cichorium intybus and Astragalus echinops were selected. A clear difference was observed between S. monatum and D. glomerata for tolerance to Zn toxicity and between C. intybus and A. echinops for Cu toxicity. Higher sensitivity to Zn and Cu toxicity in D. glomerata and C. intybus was associated with higher Zn and Cu accumulation in root and shoot. In order to determine the possible role of chelating/detoxifying molecules, changes in the content of amino and organic acids in response to metal treatment were studied. A relative high citrate and malate content in D. glomerata in comparison with S. monatum, was not the reason of higher Zn tolerance. In contrast, endogenous malate content in A. echinops was accompanied by higher Cu tolerance in this species. Cysteine was the only possible chelating/detoxifying molecule for Cu, but not for Zn. Our results showed that a high Cu tolerance in A. echinops was associated with higher endogenous and inducible cysteine content of shoot. Activity of peroxidase decreased under Cu toxicity, interestingly, this reduction was much higher in C. intybus (susceptible) when compared with A. echinops (tolerant). Because of possible role of lignin in establishing an apoplasmic transport barrier, higher uptake and transport of Cu into shoot in C. intybus could be due to the result of stronger inhibition of guiacol peroxisdase i.e. inhibition of lignin formation, in this species under Cu toxicity.
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Role of Phosphoramidate Antisense in Specific Inhibition of K562 Leukemic Cell Line
https://jsciences.ut.ac.ir/article_31759.html
1
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The Role of Caspase 9 during Programmed Cell Death in Ciliary Ganglia of Chick Embryos
https://jsciences.ut.ac.ir/article_31760.html
1
During programmed cell death (PCD) apoptosis is controlled by many factors such as proteases. With no specific protease (s) known during PCD in the developing nervous system so far, we sought to determine if any specific protease (s) is involved in this process and therefore used different protease inhibitors during PCD (from embryonic day 6 to 10) in chick embryos. Among the inhibitors commercially available, those for the inhibition of caspase 8, caspase 9 and calpain were used from embryonic day 6 to 9. Embryos were injected daily with 10 ?g of the inhibitors, killed at embryonic day 10 with their ciliary ganglia (CG) excised and neurons counted. The results in this study show that only inhibition of caspase 9 but not that of caspase 8 or calpain results in a significant increase in neuron numbers of the ciliary ganglia. These results suggest a key role for caspase 9 in the intracellular pathway of programmed cell death.
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Antioxidant Isozymes Activities in Potato Plants (Solanum tuberosum L.) Under Salt Stress
https://jsciences.ut.ac.ir/article_31761.html
1
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Synthesis of ZnO Nanocrystals with Hexagonal (Wurtzite) Structure in Water Using Microwave Irradiation
https://jsciences.ut.ac.ir/article_31762.html
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Nanocrystals of ZnO were prepared by microwave irradiation using Zn (II) acetate and triethanol amin (TEA) as the starting materials and water as solvent. The nanocrystals of ZnO with hexagonal (Wurtzite) structure were characterized by Xray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UVVis absorption and FTIR Spectroscopy techniques.
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Garnet (AlmandineSpessartine) Growth Zoning and Its Application to Constrain Metamorphic History in Dehsalm Complex, Iran
https://jsciences.ut.ac.ir/article_31763.html
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Dehsalm Metamorphic Complex located in east of Iran consists of regionally metamorphosed rocks intruded by three phases of granitic masses. Synkinematic porphyroblasts of garnet from staurolitegarnet schist present well preserved growth zoning. Electron microprobe analysis of selected garnets was carried out to interpret the origin and pattern of zoning in amphibolite facies garnets and its implication on tectonic history of the Dehsalm Metamorphic Complex. Qualitative and quantitative Xray maps and rimtocore profiles for Mn, Mg, and Fe reveal concentric zoning with a wellpreserved rim in garnet grains. Gradual decrease in Mn and increase in Fe and Mg from the core to the rim of the garnet porphyroblasts are indicative of continuous growth zoning and absence of retrograde diffusion in garnet. Distributions of Mg, Fe and Mn are concentric in garnet grains, while Xray map for Ca shows non concentric zoning with spherical and fan type distribution from core to rim. Concentration of Ca is not controlled by cracks and it more likely associated with the regions of crystal weakness. Field observation and absence of zoning in contemporaneous staurolite next to zoned garnet suggest that prograde metamorphism occurred at a widely spaced isograds. The presence of fine concentric growth zoning in garnet porphyroblasts indicates that staurolitegarnet schist was formed under amphibolite facies condition and prior to their homogenization in higher amphibolite facies. The wellpreserved garnet growth zoning is a sign that staurolitegarnet schists were rapidly cooled and later metamorphic phases had no effect on regional metamorphic schists in south west of the region.
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A Property of the Haar Measure of Some Special LCA Groups
https://jsciences.ut.ac.ir/article_31764.html
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The Euclidean group (Rn,+) where (n?N, plays a key role in harmonic analysis. If we consider the Lebesgue measure ()nd?xR as the Haar measure of this group then 12(2)()nd?x=d?RR. In this article we look for LCA groups K, whose Haar measures have a similar property. In fact we will show that for some LCA groups K with the Haar measure K?, there exists a constant such that 0KC>()(2)KKK?A=C?A for every measurable subset A of K. Moreover we will characterize this constant for some special groups.
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Estimation of the Survival Function for Negatively Dependent Random Variables
https://jsciences.ut.ac.ir/article_31765.html
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Let be a stationary sequence of pair wise negative quadrant dependent random variables with survival function {,1}nXn?F(x)=P[X>x]. The empirical survival function ()nFx based on 12,,...,nXXX is proposed as an estimator for ()nFx. Strong consistency and point wise as well as uniform of ()nFx are discussed
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Minimax Estimation of the Scale Parameter in a Family of Transformed ChiSquare Distributions under Asymmetric Squared Log Error and MLINEX Loss Functions
https://jsciences.ut.ac.ir/article_31766.html
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This paper is concerned with the problem of finding the minimax estimators of the scale parameter ? in a family of transformed chisquare distributions, under asymmetric squared log error (SLE) and modified linear exponential (MLINEX) loss functions, using the Lehmann Theorem [2]. Also we show that the results of Podder et al. [4] for Pareto distribution are a special case of our results for this family of distributions.
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On the Convergence Rate of the Law of Large Numbers for Sums of Dependent Random Variables
https://jsciences.ut.ac.ir/article_31767.html
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In this paper, we generalize some results of Chandra and Goswami [4] for pairwise negatively dependent random variables (henceforth r.v.’s). Furthermore, we give Baum and Katz’s [1] type results on estimate for the rate of convergence in these laws.
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Relationships between Darboux Integrability and Limit Cycles for a Class of Able Equations
https://jsciences.ut.ac.ir/article_31768.html
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We consider the class of polynomial differential equation x&= , 2(,)(,)(,)nnmnmPxyPxyPxy++++2(,)(,)(,)nnmnmyQxyQxyQxy++&=++. For where and are homogeneous polynomials of degree i. Inside this class of polynomial differential equation we consider a subclass of Darboux integrable systems. Moreover, under additional conditions we proved such Darboux integrable systems can have at most 1 limit cycle.
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Localizing of a FourLevel Atom via Absorption Spectrum
https://jsciences.ut.ac.ir/article_31769.html
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We propose a scheme for localizing an atom in a fourlevel configuration inside a classical standing wave field, conditioned upon the measurement of frequency of a weak probe field. In the classical standing wave field, the interaction between the atom and the field is position dependent due to the Rabifrequency of the driving field. Hence, as the absorption frequency of the probe field is measured the position of the atom inside the classical standing wave field will be determined. Localizing of the atom via the absorption spectrum occurs during its motion in the standing wave field. The investigation of the probe field absorption shows that the degree of localization depends on the interaction parameters such as detuning, and Rabifrequency of the driving field.
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