Multiple shoot regeneration of cotton (Gossypium hirsutum L.) via shoot apex culture system

Induction of multiple shoots of cotton (Gossypium hirsutum L.) plant in two commercial varieties (Sahel and Varamin) using shoot apex was done. Explants were isolated from 3 - 4 days old seedlings, then they were cultured on a shoot induction media, modified MS nutrient agar with combinations: 1- Kinetin (0.0, 0.5, 1.0, 1.5 mg l-1) and 6-benzyaminopurine (BAP) (0.0, 0.1, 0.5, 1.0, 1.5 mg l-1), 2- α- naphthaleneacetic acid (NAA) (0.0, 0.1, 1.0 mg l-1) and BAP (0.0, 0.1, 0.5, 1.0, 1.5 mg l-1). After 1.5 - 2 months, multiple shoot induction medium with 0.1 mg l-1 NAA and 0.1 mg l-1 BAP resulted in the highest number of regenerated shoots per explant (3 - 4 shoots per explant) for the two cultivars. Elongation of multiple shoots was obtained on modified MS nutrient agar without any phytohormone. In vitro shoots were rooted on half-strength agar-solidified MS basal medium supplied with 0.1 mg l-1 Iidole-3-butyric acid (IBA) and MS vitamins.Key words: Cotton, Shoot apex, multiple shoot

Sequence learning in Associative Neuronal-Astrocytic Network

The neuronal paradigm of studying the brain has left us with limitations in both our understanding of how neurons process information to achieve biological intelligence and how such knowledge may be translated into artificial intelligence and its most brain-derived branch, neuromorphic computing. Overturning our fundamental assumptions of how the brain works, the recent exploration of astrocytes is revealing that these long-neglected brain cells dynamically regulate learning by interacting with neuronal activity at the synaptic level. Following recent experimental evidence, we designed an associative, Hopfield-type, neuronal-astrocytic network and analyzed the dynamics of the interaction between neurons and astrocytes. We show that astrocytes were sufficient to trigger transitions between learned memories in the neuronal component of the network. Further, we mathematically derived the timing of the transitions that was governed by the dynamics of the calcium-dependent slow-currents in the astrocytic processes. Overall, we provide a brain-morphic mechanism for sequence learning that is inspired by, and aligns with, recent experimental findings. To evaluate our model, we emulated astrocytic atrophy and showed that memory recall becomes significantly impaired after a critical point of affected astrocytes was reached. This brain-inspired and brain-validated approach supports our ongoing efforts to incorporate non-neuronal computing elements in neuromorphic information processing.Comment: 8 pages, 5 figure

Global urban environmental change drives adaptation in white clover.

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale