391 research outputs found

    Bimolecular Recombination Reactions: Low Pressure Rates in Terms of Time-Dependent Survival Probabilities, Total J Phase Space Sampling of Trajectories, and Comparison with RRKM Theory

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    We consider the bimolecular formation and redissociation of complexes using classical trajectories and the survival probability distribution function P(E,J,t) of the intermediate complexes at time t as a function of the energy E and total angular momentum quantum number J. The P(E,J,t) and its deviation from single exponential behavior is a main focus of the present set of studies. Together with weak deactivating collisions, the P(E,J,t) and a cumulative reaction probability at the given E and J can also be used to obtain the recombination rate constant k at low pressures of third bodies. Both classical and quantum expressions are given for k in terms of P(E,J,t). The initial conditions for the classical trajectories are sampled for atom−diatom reactions for various (E,J)’s using action-angle variables. A canonical transformation to a total J representation reduces the sampling space by permitting analytic integration over several of the variables. A similar remark applies for the calculation of the density of states of the intermediate complex ρ and for the number of states N* of the transition state as a function of E and J. The present approach complements the usual approach based on the rate of the reverse reaction, unimolecular dissociation, and the equilibrium constant. It provides results not necessarily accessible from the unimolecular studies. The formalism is applied elsewhere to the study of nonstatistical aspects of the recombination and redissociation of the resulting ozone molecules and comparison with RRKM theory

    Contextualizing Kurdish gender studies decolonial feminist knowledge production and the genesis of the Kurdish Gender Studies Network

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    Established in 2020, the Kurdish Gender Studies Network (KGSN) is an online epistemic community that brings together activists and scholars dedicated to advancing knowledge in Kurdish gender and sexuality studies. This paper aims to introduce the network to a larger public while situating the formation of the KGSN in relation to the growth of Kurdish gender studies (KGS), and the increasing influence of women and queer scholars in Kurdish studies (KS) since 2010. It highlights that both KGSN and KS have been greatly influenced by the conditions shaped by the colonial legacy surrounding Kurdistan and the Kurdish issue while discussing the ways in which Kurdish women’s and gender studies were often marginalized in KS. As Kurdish women scholars and members of the network’s steering committee, we position the trajectory of the network and the evolution of KGS within the broader framework of knowledge production in colonial contexts and address the ongoing struggle to decolonize feminist knowledge production, which, historically, has been dominated by Western-centric epistemologies and methodologies

    Proline, protein, RWC and MSI contents affected by paclobutrazol and water deficit treatments in strawberry cv. Paros

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    Drought is one of the critical environmental stresses that affect growth and development of plants. Plants are damaged directly and indirectly under drought stress. Increasing water stress tolerance in plants is crucial. The aim of this study was to investigate the effects of different water stress levels (-1, -5, and -10 bars) and paclobutrazol application (0 and 50 mg-l) on strawberry cv. Paros. According to analyses of variance there were significant effects of drought stress and paclobutrazol application on leaf area, leaf dry weight, leaf relative water content (RWC), cell membrane stability index (MSI), proline and protein content of leaves. Leaf area, leaf dry weight, leaf relative water content and cell membrane stability index decreased in drought stress, especially at -10 bars. Proline and protein contents were enhanced by increasing water stress levels. Paclobutrazol application increased leaf relative water content and cell membrane stability index, proline and protein contents of leaves. Leaf relative water content was 68.77% in -10 bars drought stress that increased to 79% in paclobutrazol treatment. Also, cell membrane stability index was 69.65% in severe drought stress and reached to 77% in paclobutrazol treatment. According to the results pacloburazol is a benefit substance to ameliorate drought stress effects in strawberry cv. Paros

    Association between p53 codon 72 polymorphism and systemic lupus erythematosus

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    Aim: Systemic lupus erythematosus (SLE) is a systemic vasculitic disorder, with multiple genes involved in the disease pathogenesis. The p53 gene plays an important role in controlling the cell cycle. We aimed to study the prevalence of p53 polymorphism in SLE patients and analyze the relationship between the p53 polymorphism and clinical-laboratory features of the disease. Material and methods: This case-control study was conducted on patients with confirmed SLE at Namazi Hospital, Shiraz, Iran. Seventy-seven patients with SLE including 9 (11.8) men and 68 (88.2) women with mean age of 25.61 ± 10.69 years and 80 healthy controls with mean age of 51.82 ±14.25 years were included. The patients' information, including the epidemiological profile, disease history, disease symptoms and also the laboratory findings, were extracted from the hospital records. The p53 expression was determined in lyzed lymphocytes. The data were analyzed using SPSS software version 14.00 for Windows considering p < 0.05 as statistically significant. Results: The frequencies of Arg/Arg, Pro/Pro and Arg/Pro among normal controls were 38.8, 28.8 and 37.5, respectively, but in the patients, Arg/Arg, Pro/Pro and Arg/Pro genotypes frequencies were shown to be 29.2, 12.3 and 58.5, respectively. Thus, heterozygous form of this polymorphism was shown to be associated with the disease more than the homozygous alleles. There was a significant relationship between the different allele types of p53 and some clinical features of SLE. There was no association between the different allele types and any of the initial manifestations of the disease and the laboratory findings, as well. Conclusions: In an Iranian population the functional oncoprotein of p53 with codon 72 polymorphism may play an important role in the pathogenesis and clinical presentation of SLE
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