129 research outputs found
Diversity of arbuscular mycorrhizal fungal spores associated with Sorbus torminalis (L.) Crantz
This study aimed to investigate the diversity and types of arbuscular mycorrhizal fungi (AMF) associated with the
wild service tree, Sorbus torminalis (L.) Crantz in spring and autumn followed by identifying similarities among
the different study sites. Three different sites were selected including Kheiroud, Lalis, and Tarkin, in the Hyrcanian
forests, north of Iran. Five rhizosphere soil samples were collected from each site, and the spores were extracted.
Based on their morphological features, five species of AMF belonging to two families, i.e., Claroideoglomeraceae
(two species) and Glomeraceae (three species) were identified. The species richness of the studied sites was
identical with only the Kheiroud site presenting an additional species. Glomus badium was the most common AMF
species in Kheiroud and Lalis in spring and autumn. However, the most common species in Tarkin was Septoglomus
constrictum. The ShannonâWiener indices of diversity and evenness and Simpsonâs index of dominance (Ds)
showed no significant differences among the studied sites in the two seasons. In sum, it is recommended that the
colonized wild service tree seedlings be produced with the more relevant species identified in this study than with
commercial sources
Constitutively elevated levels of SOCS1 suppress innate responses in DF-1 immortalised chicken fibroblast cells.
The spontaneously immortalised DF-1 cell line is rapidly replacing its progenitor primary chicken embryo fibroblasts (CEFs) for studies on avian viruses such as avian influenza but no comprehensive study has as yet been reported comparing their innate immunity phenotypes. We conducted microarray analyses of DF-1 and CEFs, under both normal and stimulated conditions using chicken interferon-α (chIFN-α) and the attenuated infectious bursal disease virus vaccine strain PBG98. We found that DF-1 have an attenuated innate response compared to CEFs. Basal expression levels of Suppressor of Cytokine Signalling 1 (chSOCS1), a negative regulator of cytokine signalling in mammals, are 16-fold higher in DF-1 than in CEFs. The chSOCS1 âSOCS boxâ domain (which in mammals, interacts with an E3 ubiquitin ligase complex) is not essential for the inhibition of cytokine-induced JAK/STAT signalling activation in DF-1. Overexpression of SOCS1 in chIFN-α-stimulated DF-1 led to a relative decrease in expression of interferon-stimulated genes (ISGs; MX1 and IFIT5) and increased viral yield in response to PBG98 infection. Conversely, knockdown of SOCS1 enhanced induction of ISGs and reduced viral yield in chIFN-α-stimulated DF-1. Consequently, SOCS1 reduces induction of the IFN signalling pathway in chicken cells and can potentiate virus replication
Supermodal Decomposition of the Linear Swing Equation for Multilayer Networks
We study the swing equation in the case of a multilayer network in which generators and motors are modeled differently; namely, the model for each generator is given by second order dynamics and the model for each motor is given by first order dynamics. We also remove the commonly used assumption of equal damping coefficients in the second order dynamics. Under these general conditions, we are able to obtain a decomposition of the linear swing equation into independent modes describing the propagation of small perturbations. In the process, we identify symmetries affecting the structure and dynamics of the multilayer network and derive an essential model based on a âquotient network.â We then compare the dynamics of the full network and that of the quotient network and obtain a modal decomposition of the error dynamics. We also provide a method to quantify the steady-state error and the maximum overshoot error. Two case studies are presented to illustrate application of our method
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