207 research outputs found

    A theoretical and experimental study of geometric networks

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    Cumulative Stressors in Preterm Infants Hospitalized in Neonatal Intensive Care Units

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    Background: Infants’ exposure to stressors in neonatal intensive care unit (NICU) and its outcomes is a new issue since previous studies have only focused on painful stimuli. Taking into account frequency and severity of the stressors on each infant, short and long-term outcome of these stressors can be improved. Objectives: This study aimed to evaluate the cumulative stressors in premature infants hospitalized in a NICU. Methods: In this descriptive study, 197 hospitalized preterm infants between 28 to 30 weeks of gestation were studied in terms of cumulative stressors during 10 days at the NICU of Tabriz Alzahra hospital. Consecutive sampling method was used. Demographic questionnaire and neonatal infant stressor scale were used. Descriptive statistics, repeated measures analysis and Pearson’s correlation coefficient tests were used to analyze the data. Results: The total mean of stress scores during 10 days was 99.44 ± 17.37. “Multiple attempts to insert intravenous and intra-arterial catheters and “intubation” were the most frequent procedures in the “extremely stressful” category among four categories of stressors. The highest scores of acute and chronic stress were related to the tenth and third day of hospitalization, respectively. There was no significant difference between infants’ characteristics and total mean stress scores. Repeated measures analysis showed that the mean acute stress scores were significantly different among the 10 subsequent days (P < 0.05). Conclusions: The results of this study demonstrated the frequent occurrence of various procedures in preterm infants hospitalized at the NICU. Although these procedures were done with the purpose of improving infants’ health, they can lead to problems and complications, which might postpone the infants’ recovery process

    Coping With Stress in Iranian School-Age Children

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    Background: Methods learnt by children to cope with stress will be used in their adolescence. Failure to learn adaptive coping strategies causes some mental, physical and behavioral problems which continue until adulthood. Objectives: The current study was conducted to investigate the methods of coping with stress among Iranian school-age children. Patients and Methods: A descriptive study was conducted in which a randomly selected sample of 839 students of third to fifth grade of primary school in Tabriz, Iran participated. The data were collected using the Schoolagers` Coping Strategies Inventory questionnaire. SPSS software was employed to analyze the data by percentage, absolute frequency, and linear regression test. Results: All coping methods inserted in the questionnaire were used by students. More than 70% of students mentioned “pray”, “say I’m sorry or tell the truth”, and “try to relax, stay calm” out of 26 cases of coping strategies. According to more than 60% of children, “pray”, “say I’m sorry or tell the truth”, and “draw, write, or read something” were the most useful coping methods and “pick on someone” and “yell or scream” were not mostly used by the children under study. Conclusions: Children use variable methods to cope with their stress. Therefore, parents, health trainers and school authorities should distinguish non-adaptive methods of children and teach them the adaptive coping strategies

    Efficient Strategies for Elimination of Phenolic Compounds During DNA Extraction From Roots of Pistacia Vera L.

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    Optimization of DNA extraction protocols for plant tissues and including endophytic microorganisms is a critical step of advanced plant-microbe interaction in agricultural studies. Pistachio (Pistacia vera L.) root tissue contains high levels of polyphenols have been known as major extract contaminants and inhibitors of enzymatic activities during amplification. The present study aimed to develop reliable strategies to purify DNA from Pistachio root samples. Inhibiting substances were removed from DNA through a process including extraction with hot detergent contains SDS-Tris- EDTA, AlNH4(SO4)2.12H2O as chemical coagulating factor and CTAB-NaCl. Following typically organic extraction/alcohol precipitation, denaturing agarose electrophoresis performed to purify probable remain contaminants. The purified DNA was enough free of polyphenols based upon loss of color and spectral quality (260/230&gt;1.6) and efficiently amplified during polymerase chain reaction particularly in the present of GC-clamp primers. This method proved well with detection of Glomus sp. (arbuscular mycorrhiza fungi) associated with Pistacia vera L. using denaturing gradient gel electrophoresis (DGGE)

    Mixing and localization in random time-periodic quantum circuits of Clifford unitaries

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    How much do local and time-periodic dynamics resemble a random unitary? In the present work, we address this question by using the Clifford formalism from quantum computation. We analyze a Floquet model with disorder, characterized by a family of local, time-periodic, and random quantum circuits in one spatial dimension. We observe that the evolution operator enjoys an extra symmetry at times that are a half-integer multiple of the period. With this, we prove that after the scrambling time, namely, when any initial perturbation has propagated throughout the system, the evolution operator cannot be distinguished from a (Haar) random unitary when all qubits are measured with Pauli operators. This indistinguishability decreases as time goes on, which is in high contrast to the more studied case of (time-dependent) random circuits. We also prove that the evolution of Pauli operators displays a form of mixing. These results require the dimension of the local subsystem to be large. In the opposite regime, our system displays a novel form of localization, produced by the appearance of effective one-sided walls, which prevent perturbations from crossing the wall in one direction but not the other

    Optical isolation via PT-symmetric nonlinear Fano resonances

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    We show that Fano resonances created by twoPT -symmetric nonlinear micro-resonators coupled to a waveguide, have line-shape and resonance position that depends on the direction of the incident light. We utilize these features in order to induce asymmetric transport, up to 47 dBs, in the optical C-window. Our theoretical proposal requires low input power and does not compromise the power or frequency characteristics of the output signal

    A perspective on the pathway to a scalable quantum internet using rare-earth ions

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    The ultimate realization of a global quantum internet will require advances in scalable technologies capable of generating, storing, and manipulating quantum information. The essential devices that will perform these tasks in a quantum network are quantum repeaters, which will enable the long-range distribution of entanglement between distant network nodes. In this perspective, we provide an overview of the primary functions of a quantum repeater and discuss progress that has been made toward the development of repeaters with rare-earth ion doped materials while noting challenges that are being faced as the technologies mature. We give particular attention to erbium, which is well suited for networking applications. Finally, we provide a discussion of near-term benchmarks that can further guide rare-earth ion platforms for impact in near-term quantum networks
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