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This study investigates the dynamics of a modified Colpitts oscillator, exhibiting complex periodic and chaotic behaviors. Our research explores the dynamics and synchronization of coupled chaotic Colpitts oscillators, crucial for understanding their potential applications and behaviors. The main discovery is the emergence of a phase in which the systems achieve either complete synchronization or desynchronization. This behavior depends on the values of the coupling parameter. The subsequent challenge involves understanding how the coupling parameter influences the emergence of this synchronization phenomenon.

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Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are absent or incompatible, there are (at least) two types of inducible antiviral immunity: RNA silencing (RNAi) and immune responses mounted upon activation of nucleotide-binding domain leucine-rich repeat (NLR) receptors. RNAi is associated with viral symptom recovery through translational repression and transcript degradation following recognition of viral double-stranded RNA produced during infection. NLR-mediated immunity is induced upon (in)direct recognition of a viral protein by an NLR receptor, triggering either a hypersensitive response (HR) or an extreme resistance response (ER). During ER, host cell death is not apparent, and it has been proposed that this resistance is mediated by a translational arrest (TA) of viral transcripts. Recent research indicates that translational repression plays a crucial role in plant antiviral resistance. This paper reviews current knowledge on viral translational repression during viral recovery and NLR-mediated immunity. Our findings are summarized in a model detailing the pathways and processes leading to translational arrest of plant viruses. This model can serve as a framework to formulate hypotheses on how TA halts viral replication, inspiring new leads for the development of antiviral resistance in crops.

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We study the synchronization of two coupled idealized economies. In the present work, we consider a recently developed economic system that shows a richness of dynamical behavior. By means of the Lyapunov exponents, we analyze that there is overly complex behavior in the transitions in the dynamics of an isolated economy, oscillating between chaotic attractors and limit cycles. Then, for two coupled economies, we analyze the synchronization states for the space of all control parameters as a function of the network coupling parameter. Interestingly, we have evidenced that there is a broad region of fully synchronized states and as we increase the coupling, some phenomena such as a smooth and intermittent loss in synchronization emerge. In the same way, we observe phase synchronization for one of the control parameters. Ultimately, in order to confirm this loss of synchronization, we inspect the stability of synchronized states through the master stability function method for some control parameters. Here, we corroborate what was previously observed, the unexpected vast range of control parameter values of instability corresponding to desynchronization.

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This paper presents the optimal control and synchronization problem of a multilevel network of Rössler chaotic oscillators. Using the Hamilton-Jacobi-Bellman technique, the optimal control law with a three-state variable feedback is designed such that the trajectories of all the Rössler oscillators in the network are optimally synchronized at each level. Furthermore, we provide numerical simulations to demonstrate the effectiveness of the proposed approach for the cases of one and three networks. A perfect correlation between the MATLAB and PSpice results was obtained, thus allowing the experimental validation of our designed controller and shows the effectiveness of the theoretical results.

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We study the dynamics of a multilayer network of chaotic oscillators subject to amplification. Previous studies have proven that multilayer networks present phenomena such as synchronization, cluster, and chimera states. Here, we consider a network with two layers of Rössler chaotic oscillators as well as applications to multilayer networks of the chaotic jerk and Liénard oscillators. Intra-layer coupling is considered to be all to all in the case of Rössler oscillators, a ring for jerk oscillators and global mean field coupling in the case of Liénard, inter-layer coupling is unidirectional in all these three cases. The second layer has an amplification coefficient. An in-depth study on the case of a network of Rössler oscillators using a master stability function and order parameter leads to several phenomena such as complete synchronization, generalized, cluster, and phase synchronization with amplification. For the case of Rössler oscillators, we note that there are also certain values of coupling parameters and amplification where the synchronization does not exist or the synchronization can exist but without amplification. Using other systems with different topologies, we obtain some interesting results such as chimera state with amplification, cluster state with amplification, and complete synchronization with amplification.

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For seed germination, it is necessary to restart the cell cycle, a process regulated at multiple levels including transcriptional control, that is executed by the E2F family of transcription factors. We identified 12 genes of the E2F family in maize that are expressed differentially during the first 28 h post imbibition (HAI). E2Fa/b1;1 and E2Fc proteins were characterized as an activator and a putative repressor respectively, both forming heterodimers with DPb2 that bind differentially to consensus E2F response elements in promoters of E2F target genes. Transcripts of target genes for these transcription factors accumulate during germination; in dry seeds E2Fc protein is enriched in the target promoters and is replaced by E2Fa/b1;1 as germination advances. RBR1 is found in the same promoters in non-imbibed and 28 HAI seeds, when DNA replication has concluded, and transcription of the E2F targets should stop. During germination promoters of these target genes seem to be decorated with histone marks related to relaxed chromatin structure. Therefore, E2Fs appear to occupy their target genes in a context of open chromatin, with RBR1 fine tuning the progression between the phases.

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Glucose and sucrose play a dual role: as carbon and energy sources and as signaling molecules. In order to address the impact that sugars may have on maize seeds during germination, embryo axes were incubated with or without either of the two sugars. Expression of key cell cycle markers and protein abundance, cell patterning and de novo DNA synthesis in root meristem zones were analyzed. Embryo axes without added sugars in imbibition medium were unable to grow after 7 days; in sucrose, embryo axes developed seminal and primary roots with numerous root hairs, whereas in glucose axes showed a twisted morphology, no root hair formation but callus-like structures on adventitious and primary seminal roots. More and smaller cells were observed with glucose treatment in root apical meristems. de novo DNA synthesis was stimulated more by glucose than by sucrose. At 24 h of imbibition, expression of ZmCycD2;2a and ZmCycD4;2 was increased by sucrose and reduced by glucose. CDKA1;1 and CDKA2;1 expression was stimulated equally by both sugars. Protein abundance patterns were modified by sugars: ZmCycD2 showed peaks on glucose at 12 and 36 h of imbibition whereas sucrose promoted ZmCycD3 protein accumulation. In presence of glucose ZmCycD3, ZmCycD4 and ZmCycD6 protein abundance was reduced after 24 h. Finally, both sugars stimulated ZmCDKA protein accumulation but at different times. Overall, even though glucose appears to act as a stronger mitogen stimulator, sucrose stimulated the expression of more cell cycle markers during germination. This work provides evidence of a differential response of cell cycle markers to sucrose and glucose during maize germination that may affect the developmental program during plantlet establishment.

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La Tuberculina evalúa la infección por tuberculosis que depende de la inmunidad celular; se informa en nuestro país baja prevalencia de PPD positivo en pacientes con AR frente a controles sanos; este procedimiento perdería validez en nuestro medio como tamizaje adecuado antes de usar agentes biológicos; el uso indiscriminado de la profilaxis TBC con isoniacida traería hepatotoxicidad que se incrementa hasta en un 50 por ciento cuando se asocia a metotrexate, sulfazalasina o agentes anti-TNF sin dejar de lado la posibilidad de desarrollo de resistencia a la medicación. Objetivo: evaluar la positividad del PPD en AR frente a controles intradomiciliarios. Métodos: se estudiaron 47 pacientes AR, 45 de sexo femenino (95,8 por ciento) y dos varones (4,2 por ciento), y 47 controles contacto intradomiciliario. Fueron utilizadas 2UT contenidas en 0.1 ml. Para evitar booster no hubo PPD en el último mes. Se tomó positividad del PPD en AR³5 mm y controles³10 mm. Se usó la versión 7,5 de SPSS. Las medias de la edad y la medición de la reacción al PPD se analizaron por ANOVA, correlación de Spearman, X² y prueba Z para comparar proporciones. Resultados: la edad promedio de los pacientes fue 51,7 años y de los contactos fue 41,1 años; el tiempo de enfermedad promedio fue 12,74 años, la lectura promedio en AR fue 6,62 mm y en contacto intradomiciliario, 9,55mm (ANOVA= 0,189). El porcentaje de pacientes AR con PPD (+) fue similar a los controles, 46,80 por ciento vs. 51,10 por ciento(p<0,02). PPD (+) entre los pacientes AR inmunosuprimidos y no inmunosuprimidos, 40,50 por ciento vs. 70,00 por ciento (p< 0,03); hubo correlación entre lecturas de 53,20 por ciento, así para PPD (+) coincidieron los resultados en 25,50 por ciento y para PPD (-) en 27,70 por ciento (Spearman= 0.4), (p< 0,04), correlación significativa de positividad o negatividad (X² 0,021). Conclusiones: encontramos una proporción PPD(+) de 51,10 por ciento en los controles en comparación de 46,80 por ciento de los pacientes AR. La proporción de PPD (-) es mayor en los pacientes AR inmunosuprimidos que en los no inmunosuprimidos 59,50 por ciento vs. 30,00 por ciento

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