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

On optimization and solution of roots of a function using Taylor's expansion and fractional derivatives

A method is given for finding roots of a one-variable function using Taylor's expansion of that function and fractional derivative calculated at a suitable tangent point without using Newton's method. Several examples regarding polynomials are stated for making the method clearly. Then, the given method is generalized to functions of several variables belonging to an $n$-dimensional space. The given method can be much more rapidly than the Newton's one since finding a suitable point on the function, the number of iterations becomes much less than Newton's iterative steps. The methods given in this paper can be used for optimization of function via fractional derivatives of order $\beta$.Comment: 15 pages, 1 figur

Aceite de Kilka común y su dinámica oxidativa primaria y secundaria estabilizada por diferentes variantes de aceite esencial de clavo

The objective of this study was to investigate the properties of clove essential oil extracted by different microwave-assisted methods and to evaluate its effects on the stability of common Kilka oil. Each of these methods was hypothesized to yield a clove essential oil that would have a distinguishable composition and effect when added to common Kilka oil by maintaining its oxidative stability. The oxidation of common Kilka oil was examined by accelerated oxidation using the active oxygen method and Rancimat test. The clove essential oil extracted by microwave-assisted hydrodistillation showed the highest induction period according to the active oxygen method (16.56 h) and the Rancimat induction period (3.64 h) in common Kilka oil and its antioxidant activity was comparable to that of BHT (16.59 h and 4.34 h, respectively) and tocopheryl acetate (16.30 h and 4.02 h, respectively). Furthermore, the microwaveassisted hydrodistillation method resulted in the amount of eugenol that exhibited the highest antioxidant capacity for preserving PUFA in common Kilka oil. Ultimately, clove essential oil can become an efficient natural antioxidant for the oxidative stability of common Kilka oil.El objetivo de este estudio fue investigar las propiedades de los aceites esenciales de clavo que se extrajeron utilizando diferentes métodos asistidos por microondas y evaluar los efectos de estos aceites esenciales en la estabilidad del aceite de Kilka común. Se hipotetizó que cada uno de los métodos produce un aceite esencial de clavo que tendría una composición y un efecto distintivo cuando se agrega al aceite de Kilka común manteniendo su estabilidad oxidativa. La oxidación del aceite de Kilka común se determinó mediante oxidación acelerada utilizando el método de oxígeno activo y Rancimat. El aceite esencial de clavo extraído por hidrodestilación asistida por microondas logró en el aceite de Kilka común un período de inducción, mediante el método de oxígeno activo, más alto (16,56 h) y un período de inducción mediante Rancimat de 3,64 h y su actividad antioxidante fue comparable a la del BHT (16,59 h y 4,34 h, respectivamente) y a la del acetato de tocoferol (16,30 h y 4,02 h, respectivamente). Además, el método de hidrodestilación asistido por microondas influyó en la cantidad de eugenol que presentó una mayor capacidad antioxidante para preservar los PUFAs del aceite de Kilka común. Por último, el aceite esencial de clavo puede convertirse en un antioxidante natural eficiente para la estabilidad oxidativa del aceite de Kilka común

Evaluation of genetic diversity of Iranian grapevine accessions using microsatellite markers

Research Note

In vivo imaging reveals sigmoidal growth kinetic of β-amyloid plaques

A major neuropathological hallmark of Alzheimer's disease is the deposition of amyloid plaques in the brains of affected individuals. Amyloid plaques mainly consist of fibrillar β-amyloid, which is a cleavage product of the amyloid precursor protein. The amyloid-cascade-hypothesis postulates Aβ accumulation as the central event in initiating a toxic cascade leading to Alzheimer's disease pathology and, ultimately, loss of cognitive function. We studied the kinetics of β-amyloid deposition in Tg2576 mice, which overexpress human amyloid precursor protein with the Swedish mutation. Utilizing long-term two-photon imaging we were able to observe the entire kinetics of plaque growth in vivo. Essentially, we observed that plaque growth follows a sigmoid-shaped curve comprising a cubic growth phase, followed by saturation. In contrast, plaque density kinetics exhibited an asymptotic progression. Taking into account the fact that a critical concentration of Aβ is required to seed new plaques, we can propose the following kinetic model of β-amyloid deposition in vivo. In the early cubic phase, plaque growth is not limited by Aβ concentration and plaque density increases very fast. During the transition phase, plaque density stabilizes whereas plaque volume increases strongly reflecting a robust growth of the plaques. In the late asymptotic phase, Aβ peptide production becomes rate-limiting for plaque growth. In conclusion, the present study offers a direct link between in vitro and in vivo studies facilitating the translation of Aβ-lowering strategies from laboratory models to patients

Tcf4 regulates dendritic spine density and morphology in the adult brain

Tcf4 is a transcription factor which regulates neurogenesis and neuronal migration in the brain. In humans, loss of function of Tcf4 leads to the rare neurodevelopmental disorder Pitt-Hopkins syndrome, which is characterized by intellectual disability, developmental delay and autistic behavior. We analyzed the consequences of functional loss of Tcf4 on dendritic spines in mature principal neurons. To this end, we crossed mice in which the DNA-binding domain of the Tcf4 gene is flanked by LoxP sites to mice expressing tamoxifen-inducible cre recombinase in a sparse subset of fluorescently labelled neurons (SlickV line). This resulted in a mouse model with an inducible functional knockout of Tcf4 in a subset of cortical and hippocampal neurons, in which we analyzed dendritic spines, which are the morphological correlate of excitatory postsynapses. Heterozygous as well as homozygous loss of Tcf4 led to a reduction in the number of dendritic spines in the cortex as well as in the hippocampus. This was accompanied by morphological changes of dendritic spines. These results suggest that Tcf4 is involved in synaptic plasticity in mature neurons, and functional loss of Tcf4 may contribute to the neurological symptoms in Pitt-Hopkins syndrome

The Use of Radiofrequency Energy in Pediatric Cardiology

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73038/1/j.1540-8183.1995.tb00583.x.pd

The Role of APP in Structural Spine Plasticity

Amyloid precursor protein (APP) is a transmembrane protein highly expressed in neurons. The full-length protein has cell-adhesion and receptor-like properties, which play roles in synapse formation and stability. Furthermore, APP can be cleaved by several proteases into numerous fragments, many of which affect synaptic function and stability. This review article focuses on the mechanisms of APP in structural spine plasticity, which encompasses the morphological alterations at excitatory synapses. These occur as changes in the number and morphology of dendritic spines, which correspond to the postsynaptic compartment of excitatory synapses. Both overexpression and knockout (KO) of APP lead to impaired synaptic plasticity. Recent data also suggest a role of APP in the regulation of astrocytic D-serine homeostasis, which in turn regulates synaptic plasticity

The brain-specific double-stranded RNA-binding protein Staufen2 is required for dendritic spine morphogenesis

Mammalian Staufen2 (Stau2) is a member of the double-stranded RNA-binding protein family. Its expression is largely restricted to the brain. It is thought to play a role in the delivery of RNA to dendrites of polarized neurons. To investigate the function of Stau2 in mature neurons, we interfered with Stau2 expression by RNA interference (RNAi). Mature neurons lacking Stau2 displayed a significant reduction in the number of dendritic spines and an increase in filopodia-like structures. The number of PSD95-positive synapses and miniature excitatory postsynaptic currents were markedly reduced in Stau2 down-regulated neurons. Akin effects were caused by overexpression of dominant-negative Stau2. The observed phenotype could be rescued by overexpression of two RNAi cleavage-resistant Stau2 isoforms. In situ hybridization revealed reduced expression levels of β-actin mRNA and fewer dendritic β-actin mRNPs in Stau2 down-regulated neurons. Thus, our data suggest an important role for Stau2 in the formation and maintenance of dendritic spines of hippocampal neurons