105 research outputs found

    Persuasive Discourse Impairments in Traumatic Brain Injury

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    Background: Considering the cognitive and linguistic complexity of discourse production, it is expected that individuals with traumatic brain injury (TBI) should face difficulties in this task. Therefore, clinical examination of discourse has become a useful tool for studying and assessment of communication skills of people suffering from TBI. Among different genres of discourse, persuasive discourse is considered as a more cognitively demanding task. However, little is known about persuasive discourse in individuals suffering from TBI. Objectives: The purpose of this study was to evaluate the performance of adults with TBI on a task of spoken persuasive discourse to determine the impaired linguistic measures. Patients and Methods: Thirteen TBI nonaphasic Persian speaking individuals, ranged between 19 to 40 years (Mean = 25.64 years; SD = 6.10) and 59 healthy adults matched by age, were asked to perform the persuasive discourse task. The task included asking the participants to express their opinion on a topic, and after the analysis of the produced discourse, the two groups were compared on the basis of their language productivity, sentential complexity, maze ratio and cohesion ratio. Results: The TBI group produced discourses with less productivity, sentential complexity, cohesion ratio and more maze ratio compared the control group. Conclusions: As it is important to consider acquired communication disorders particularly discourse impairment of brain injured patients along with their other clinical impairments and regarding the fact that persuasive discourse is crucial in academic and social situations, the persuasive discourse task presented in this study could be a useful tool for speech therapists, intending to evaluate communication disorders in patients with TBI

    Investigation the Different Levels of Drought Stress on Almond Cultivars

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    Introduction  Water shortage is very frequent in many countries, and, together with the rising demand for industry, growth of human population, climate change and specifically the trend towards irrigated agriculture, has led to widespread problems of water scarcity, especially in Middle East countries. This situation imposes the need to optimize water use in all human activities. Among the different productive uses of water, agriculture is by far the main water user in most water scarce regions and, consequently, any potential improvement in the use of the available water resources may play a significant role toward achieving a more sustainable use of water. Plant responses to water deprivation are usually monitored through selected morphological and physiological parameters which have been proven to be good indicators of drought in different studies. Some of the most important standards for evaluating plant genotypes under drought stress are measurements of morphological parameters such as height, leaf characters and root growth.   Materials and Methods  To compare the growth response of different almond cultivars to different levels of water stress, an experiment was conducted as a split plot in the base of randomized complete block design with three replications in the Agricultural and Natural Resources Research Center of Chaharmahal and Bakhtiari Province in two growing season 2019-2020 and 2020-2021. Different irrigation periods based on the percentage of usable soil moisture between filed capacity to wilting point, including 70% filed capacity (control or no stress), 50% filed capacity (mild stress), 30% filed capacity (medium stress) and 10% of field capacity (severe stress) were considered as the main factor of the experiment. The sub-factor included 14 commercial cultivars of almonds (Mamaei, Rabi, Saba, Araz, Eskandar, Aidin, Shahrood 6, 7, 8, 10, 12, 13 and 21 and GN vegetative rootstock), all of which were grafted on GN rootstock. In this study, uniformly grafted seedlings in terms of age, stem diameter and height were selected and planted. In the second year after planting the seedlings, in order to apply drought stress, tubes for hygrometer (TDR) were installed in each experimental plot and based on soil moisture content, irrigation cycle was determined for different treatments.   Results and Discussion  In both years, three months after applied water stress growth traits and nutrient concentrations in the leaves of treated seedlings were measured. Based on the results of analysis of variance, the morphological traits of almond seedlings were significantly affected by cultivar type and drought stress level. In all almond cultivars, the highest height was belonged to seedlings that were grown in non-stress conditions and with increasing the drought stress intensity, the height of almond seedlings was decreased. Under severe drought stress, GN and Mamaei cultivars had the highest (183.93 cm) and the lowest (94.60 cm) height, respectively. Seedling height in GN, Shahrood 12, Saba and Shahrood 10 cultivars showed the lowest decrement under severe drought stress. In all cultivars, drought stress caused a significant reduction in the length and width of the seedlings crown, and the greatest decreasing was recorded in severe drought stress (10% FC). Under severe drought stress, cultivar GN had the largest crown and cultivars Rabi, Shahrood 7 and Eskandar had the smallest crown. Increasing the drought stress intensity significantly reduced the branches growth of seeding in terms of number and length of sub-branches. As the intensity of drought stress increased, the length of sub-branches decreased however the number of intermediates in sub-branches increased. In non-stressed condition, the cultivar GN had the longest branch (55.95 cm), which was significantly higher than the other studied almond cultivars. The shortest branches were also observed in Saba (29.94 cm) and Eskandar (29.47 cm) cultivars. Increasing drought stress caused a significant reduction of leaf area in all studied cultivars and the highest decreasing was observed under severe drought stress. The GN (37.76 cm²) and Shahrood 10 (31.81 cm²) had the highest leaf area in non-stress and drought stress conditions. Under severe drought stress (10% FC) cultivar Shahrood 6 showed the lowest leaf area. The results of this study showed that increasing the intensity of dehydration significantly reduced the amount of nitrogen, phosphorus, manganese and zinc in the leaves of the studied cultivars of almonds, however, the amount of potassium and iron in stressed plants increased under drought stress. Based on the results of the present study, under severe drought stress the GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth indices including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements was superior compared with the other studied cultivars.   Conclusion  Based on the results of this study, drought stress significantly reduced growth indices and nutrient concentrations, although the reaction of almond cultivars to different levels of drought stress was different. In this study, among the studied almond cultivars GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth characters including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements showed higher tolerance to different level of drought stress. These cultivars less affected by the high intensities of dehydration. Therefore, GN, Shahrood 8 and Shahrood 12 cultivars can be used in future studies to evaluate the possibility of cultivating these cultivars in areas with water deficit

    Imprinting of the MEDEA

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    Partial evaluation of machine code

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    Experimental investigation of conduction and convection heat transfer properties of a novel nanofluid based on carbon quantum dots

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    So far, many studies have been conducted on heat transfer nanofluids and various nanofluids have been synthesized and evaluated by different nanoparticles. In the present research, the use of biodegradable carbon quantum dots (CQDs) to synthesize heat transfer nanofluids was investigated for the first time. In fact, CQDs are a new generation of carbon nanoparticles and one of the advantages of which is their very small size that facilitates the prepared of nanofluids at very low concentrations with high stability. In the present research, CQDs were synthesized based on microwave method using commercial ammonium hydrogen-citrate as precursor. The nanofluid samples were synthesized based on car radiator coolant and CQDs at the concentrations of 100, 200, 500, and 1000 ppm. Thermal conductivity (k) and convection heat transfer (h) coefficients were investigated as the main features of the fluid's heat transfer characteristics. The obtained results for 200-ppm concentration indicated the improvement of k and h by 5.7% and 16.2%compared to the base fluid, respectively. Besides, the synthesized nanofluids had also significant stability and very low cost which are of great importance for industrial applications. Finally, the heat transfer process in the 200-ppm nanofluid was simulated by Ansys Fluent software

    Rate-Dependent Nucleation and Growth of NaO2 in Na-O2 Batteries

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    Understanding the oxygen reduction reaction kinetics in the presence of Na ions and the formation mechanism of discharge product(s) is key to enhancing Na–O2 battery performance. Here we show NaO2 as the only discharge product from Na–O2 cells with carbon nanotubes in 1,2-dimethoxyethane from X-ray diffraction and Raman spectroscopy. Sodium peroxide dihydrate was not detected in the discharged electrode with up to 6000 ppm of H2O added to the electrolyte, but it was detected with ambient air exposure. In addition, we show that the sizes and distributions of NaO2 can be highly dependent on the discharge rate, and we discuss the formation mechanisms responsible for this rate dependence. Micron-sized (∼500 nm) and nanometer-scale (∼50 nm) cubes were found on the top and bottom of a carbon nanotube (CNT) carpet electrode and along CNT sidewalls at 10 mA/g, while only micron-scale cubes (∼2 μm) were found on the top and bottom of the CNT carpet at 1000 mA/g, respectively.Seventh Framework Programme (European Commission) (Marie Curie International Outgoing Fellowship, 2007-2013))National Science Foundation (U.S.) (MRSEC Program, award number DMR-0819762)Robert Bosch GmbH (Bosch Energy Research Network (BERN) Grant)China Clean Energy Research Center-Clean Vehicles Consortium (CERC-CVC) (award number DE-PI0000012)Skolkovo Institute of Science and Technology (Skoltech-MIT Center for Electochemical Energy Storage

    Von Willebrand factor propeptide and pathophysiological mechanisms in European and Iranian patients with type 3 von Willebrand disease enrolled in the 3WINTERS-IPS study

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    Background Type 3 von Willebrand disease (VWD) is a severe bleeding disorder caused by the virtually complete absence of von Willebrand factor (VWF). Pathophysiological mechanisms of VWD like defective synthesis, secretion, and clearance of VWF have previously been evaluated using ratios of VWF propeptide (VWFpp) over VWF antigen (VWF:Ag) and factor (F)VIII coagulant activity (FVIII:C) over VWF:Ag. Objective To investigate whether the VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios may also be applied to understand the pathophysiological mechanism underlying type 3 VWD and whether VWFpp is associated with bleeding severity. Methods European and Iranian type 3 patients were enrolled in the 3WINTERS-IPS study. Plasma samples and buffy coats were collected and a bleeding assessment tool was administered at enrolment. VWF:Ag, VWFpp, FVIII:C, and genetic analyses were performed centrally, to confirm patients' diagnoses. VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios were compared among different variant classes using the Mann-Whitney test. Median differences with 95% confidence intervals (CI) were estimated using the Hodges-Lehmann method. VWFpp association with bleeding symptoms was assessed using Spearman's rank correlation. Results Homozygosity/compound heterozygosity for missense variants showed higher VWFpp level and VWFpp/VWF:Ag ratio than homozygosity/compound heterozygosity for null variants ([VWFpp median difference, 1.4 IU/dl; 95% CI, 0.2-2.7; P = .016]; [VWFpp/VWF:Ag median difference, 1.4; 95% CI, 0-4.2; P = .054]). FVIII:C/VWF:Ag ratio was similarly increased in both. VWFpp level did not correlate with the bleeding symptoms (r = .024; P = .778). Conclusions An increased VWFpp/VWF:Ag ratio is indicative of missense variants, whereas FVIII:C/VWF:Ag ratio does not discriminate missense from null alleles. The VWFpp level was not associated with the severity of bleeding phenotype.Peer reviewe

    Transcriptional activity of Hyacinthus orientalis L. female gametophyte cells before and after fertilization

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    We characterized three phases of Hyacinthus orientalis L. embryo sac development, in which the transcriptional activity of the cells differed using immunolocalization of incorporated 5′-bromouracil, the total RNA polymerase II pool and the hypo- (initiation) and hyperphosphorylated (elongation) forms of RNA Pol II. The first stage, which lasts from the multinuclear stage to cellularization, is a period of high transcriptional activity, probably related to the maturation of female gametophyte cells. The second stage, encompassing the period of embryo sac maturity and the progamic phase, involves the transcriptional silencing of cells that will soon undergo fusion with male gametes. During this period in the hyacinth egg cell, there are almost no newly formed transcripts, and only a small pool of RNA Pol II is present in the nucleus. The transcriptional activity of the central cell is only slightly higher than that observed in the egg cell. The post-fertilization stage is related to the transcriptional activation of the zygote and the primary endosperm cell. The rapid increase in the pool of newly formed transcripts in these cells is accompanied by an increase in the pool of RNA Pol II, and the pattern of enzyme distribution in the zygote nucleus is similar to that observed in the somatic cells of the ovule. Our data, together with the earlier results of Pięciński et al. (2008), indicate post-fertilization synthesis and the maturation of numerous mRNA transcripts, suggesting that fertilization in H. orientalis induces the activation of the zygote and endosperm genomes

    Dosage-Sensitive Function of RETINOBLASTOMA RELATED and Convergent Epigenetic Control Are Required during the Arabidopsis Life Cycle

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    The plant life cycle alternates between two distinct multi-cellular generations, the reduced gametophytes and the dominant sporophyte. Little is known about how generation-specific cell fate, differentiation, and development are controlled by the core regulators of the cell cycle. In Arabidopsis, RETINOBLASTOMA RELATED (RBR), an evolutionarily ancient cell cycle regulator, controls cell proliferation, differentiation, and regulation of a subset of Polycomb Repressive Complex 2 (PRC2) genes and METHYLTRANSFERASE 1 (MET1) in the male and female gametophytes, as well as cell fate establishment in the male gametophyte. Here we demonstrate that RBR is also essential for cell fate determination in the female gametophyte, as revealed by loss of cell-specific marker expression in all the gametophytic cells that lack RBR. Maintenance of genome integrity also requires RBR, because diploid plants heterozygous for rbr (rbr/RBR) produce an abnormal portion of triploid offspring, likely due to gametic genome duplication. While the sporophyte of the diploid mutant plants phenocopied wild type due to the haplosufficiency of RBR, genetic analysis of tetraploid plants triplex for rbr (rbr/rbr/rbr/RBR) revealed that RBR has a dosage-dependent pleiotropic effect on sporophytic development, trichome differentiation, and regulation of PRC2 subunit genes CURLY LEAF (CLF) and VERNALIZATION 2 (VRN2), and MET1 in leaves. There were, however, no obvious cell cycle and cell proliferation defects in these plant tissues, suggesting that a single functional RBR copy in tetraploids is capable of maintaining normal cell division but is not sufficient for distinct differentiation and developmental processes. Conversely, in leaves of mutants in sporophytic PRC2 subunits, trichome differentiation was also affected and expression of RBR and MET1 was reduced, providing evidence for a RBR-PRC2-MET1 regulatory feedback loop involved in sporophyte development. Together, dosage-sensitive RBR function and its genetic interaction with PRC2 genes and MET1 must have been recruited during plant evolution to control distinct generation-specific cell fate, differentiation, and development
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