276 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
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 -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 .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 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 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 molecular epidemiology of respiratory viruses in military trainees in Iran
Background: Military populations are more prone to respiratory infections worldwide. There is a dearth of research about the role of viral pathogens in the etiology of respiratory infections in military trainees in Iran. Hence, we aimed to investigate the molecular epidemiology and clinical symptoms of respiratory viruses among this population. Methods: This cross-sectional study was performed on 400 military trainees with symptoms of respiratory infection, referred to the military medical clinic center in the basic military training camp of the General Staff of the Armed Forces of the Islamic Republic of Iran. Nucleic acid extraction from the throat or nasopharyngeal swab samples was performed by an automated extraction system. The extracts were then analyzed by the CLART® PneumoVir array system for the detection of respiratory viruses. Results: All military trainees were male, aged between 18 and 57 years (mean: 21.69 years). Sore throat (75.5), rhinorrhea (63.2), cough (59.2), fever (59.2), and nasal congestion (50.5) were amongst the most common symptoms. Overall, viral pathogens were detected in a total count of 124 (31). The most commonly detected viruses were rhinovirus (7.2), respiratory syncytial virus A (7.2) and influenza B virus (6). Conclusion: This study was an important first step for understanding the etiological role of viral pathogens in respiratory infection among military trainees population in Iran. Our results indicated that rhinovirus, respiratory syncytial virus A and influenza B virus are important viral pathogens causing respiratory infection in military trainees, respectively. However, further multi-center studies with larger sample size are strongly recommended to confirm our findings. © Iran University of Medical Sciences
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