420 research outputs found

    Somatic embryogenesis in two Iranian date palm cultivars

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    Shoot tips were removed from 3 to 4 year-old offshoots of adult date palm (Phoenix dactylifera L. cv. Khanizi and Mordarsing) and were cultured on medium that consisted of Murashige and Skoog basal salts medium. After 12 months they were transferred to three different treatments of growth regulators. Five months later, cv. Khanizi produced embryogenic callus on a medium containing 453 ìM 2,4- dichlorophenoxyacetic acid (2,4-D), 15 ìM N2-(2-isopentenyl)adenine (2ip), and 13 ìM 6-benzyl amino purine. This callus was subcultured to another medium that was supplemented with 54 ìM NAA and 148 ìM 2ip. At this stage the embryos grew into plantlets. The cv. Mordarsing explants, on a medium containing 679 ìM 2,4-D and 15 ìM 2ip, produced embryogenic callus but the embryos remained in the globular stage

    Efficacy of Probiotic Escherichia coli Nissle 1917 in Patients with Irritable Bowel Syndrome: a Double Blind Placebo-controlled Randomized Trial

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    AIM: to evaluate potential improvement effect for probiotic E. coliNissle 1917 in the management of refractory IBS in an Iranian population. METHODS: a double blind placebo controlled approach has been used in the current clinical trial. 139 confirmed IBS patients were included into the study, and were given probiotic E.coli Nissle 1917 for 6 weeks. 11 items Birmingham IBS Symptom Questionnairehas been used for evaluation of changes in the symptoms every 2 weeks. CONCLUSION: probiotic therapy with E.coli Nissle 1917 was not able to induce significant improvement in the symptoms of patients with non-categorized IBS. Nevertheless, when IBS patients were recategorized to subgroups according to their main symptoms, evaluation of the efficacy of the probiotic on some individual items in the symptom list reached the significance level. Prospective clinical trials are recommended to confirm our findings. RESULTS: sixty eight subjects (49) were males. Mean±SD age of the participants was 38±13.3 years. 49(35.3) of the patients were diarrhea-predominant. The total scores showed no significant difference between the intervention vs. control group(-6.7±6.8 vs. -6.7±6.5, respectively; p=0.95); neither did any of the questionnaire items any significant alterations in the two groups. After stratification of patients based on their IBS type, diarrhea-predominant patients showed a positive response to the probiotic improving their sleep (p=0.05 and 0.03 at weeks 2 and 6, respectively). Patients with constipation-predominant IBS showed no response to the probiotic; while patients with diarrhea-constipation mixed IBS showed unfavorable response to the probiotic in the need for strain to pass a motion compared to the placebo (p=0.03 and 0.02 at weeks 4 and 6, respectively)

    Efficacy of coping mechanisms used during COVID-19 as reported by parents of children with autism

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    The COVID-19 pandemic’s alterations to daily life have been especially challenging for families with Autism Spectrum Disorder (ASD), worsening the core features of ASD and overall mental health. With the increased need for effective coping, the current retrospective study used data from a survey regarding parent reports of how often their child with ASD used certain coping strategies (frequency), as well as the extent to which they felt their child benefitted from their use (efficacy) in mitigating stress during the pandemic. This retrospective study Repeated measures ANOVAs were conducted to evaluate whether there were significant differences in both frequency and efficacy ratings for each coping strategy, for the entire sample as well as for three children’s age groups. Using Spearman’s rank-order correlations, correlation coefficients between the frequency and efficacy of each coping strategy were explored. Results revealed that maladaptive strategies were used more frequently than adaptive strategies, while parent routine as the most frequently used and efficacious for all age groups. Additionally, for adaptive strategies, humor and focusing on the positive had the strongest correlations between frequency and efficacy ratings amongst all age groups. Of the maladaptive strategies, repetitive behaviors, rumination, and isolation had the strongest correlations for the youngest, middle, and oldest age groups, respectively. Further, for each age group, the adaptive coping strategies had stronger correlations between frequency and efficacy than the maladaptive ones. It is our hope that the results of this study will lay the foundation for developing adaptive coping strategies to alleviate stress in children with ASD. Further investigations using a larger cohort are warranted to determine effective coping strategies for individuals with ASD across a range of situations, including acute stressors (such as future public health emergencies and natural disasters), as well as common daily stressors

    Prevalence of antimicrobial resistance in Helicobacter pylori isolates from Iran

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    Helicobacter pylori, a gram negative bacterium is capable of being resistant to a wide spectrum of antimicrobial drugs. The prevalence of antibiotic resistance in H. pylori strains differs amongst distinct geographical areas and has increased worldwide. Therefore, information concerning the prevalence of antimicrobial-resistant H. pylori strains is important in predicting therapeutic response. In this study, drug susceptibility of H. pylori in patients was investigated in Laleh hospital, Tehran, Iran from 2007 - 2008. 104 antral biopsies of patients with non ulcer dyspepsia and peptic ulcer were cultured. Susceptibility patterns were determined by disk diffusion method. Minimum inhibitory concentration (MIC) was performed for resistant isolates of H. pylori. In our study, 51.5% of clinical isolates showed resistance to metronidazole. All of the isolates were sensitive to other antibiotic disks including clarithromycin, amoxicillin, tetracycline and furazolidone. MIC was determined as 16 μg/ml in 5.8% and 32 μg/ml in 94.1% of isolates for metronidazole resistance isolates. The results indicated that the major drug resisted by H. pylori is metronidazole and it should be considered when recommending drugs to patients in this region.Keywords: Helicobacter pylori, antimicrobial resistance, MICAfrican Journal of Biotechnology Vol. 9(36), pp. 5962-5965, 6 September, 201

    Towards Robust and Effective Passive Compliance Design of End-Effectors for Robotic Train Fluid Servicing

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    Copyright © 2023 by the authors. Without mechanical compliance robots rely on controlled environments and precision equipment to avoid clashes and large contact forces when interacting with an external workpiece, e.g., a peg-in-hole (PiH) task. In such cases, passive compliance devices are used to reduce the insertion force (and in turn the robot payload) while guiding corrective motions. Previous studies in this field are limited to small misalignments and basic PiH geometries inapplicable to prevalent robotic and autonomous systems (RASs). In addition to these issues, our work argues that there is a lack of a unified approach to the development of passive compliance systems. To this end, we propose a higher-level design approach using robust engineering design (RED) methods. In a case study, we demonstrated this general approach with a Taguchi design framework, developing a remote centre compliant (RCC) end-effector for robotic train fluid servicing. For this specific problem, a pseudo-rigid-body model (PRBM) is suggested in order to save enormous computation time in design, modelling, and optimisation. Our results show that the compliant end-effector is capable of significantly reducing the insertion force for large misalignments up to 15 mm and 6 degrees.Rail Safety and Standards Board (RSSB), under contract RSSB 2675, and from EPSRC Impact Acceleration Account, under the Grant No. EP/X525510/1

    A Developed Methodology in Design of Highly Loaded Tandem Axial Flow Compressor Stage

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    This study, primarily reports the development of a 3D design procedure for axial flow tandem compressor stages and then the method is used to design a highly loaded tandem stage. In order to investigate the effects of such arrangement, another stage with conventional loading with single blade for both rotor and stator rows is designed with similar specification. In order to ease the comparison of results, chord lengths and hub/shroud geometries are selected with the same dimensions. At the next stage a three dimensional numerical model is developed to predict the characteristic performance of both tandem and conventional stages. The model is validated with the experimental results of NASA-67 stage and the level of the accuracy of the model is presented. Employing the model to simulate the performance of both stages at design and offdesign operating points show that, tandem stage can provide higher pressure ratio with acceptable efficiency. In another word, tandem stage is capable having the same pressure ratio at lower rotational speed. The safe operation domain and loss mechanism in tandem stage are also discussed in this report

    Reduction Operators of Linear Second-Order Parabolic Equations

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    The reduction operators, i.e., the operators of nonclassical (conditional) symmetry, of (1+1)-dimensional second order linear parabolic partial differential equations and all the possible reductions of these equations to ordinary differential ones are exhaustively described. This problem proves to be equivalent, in some sense, to solving the initial equations. The ``no-go'' result is extended to the investigation of point transformations (admissible transformations, equivalence transformations, Lie symmetries) and Lie reductions of the determining equations for the nonclassical symmetries. Transformations linearizing the determining equations are obtained in the general case and under different additional constraints. A nontrivial example illustrating applications of reduction operators to finding exact solutions of equations from the class under consideration is presented. An observed connection between reduction operators and Darboux transformations is discussed.Comment: 31 pages, minor misprints are correcte
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