Perturbations in dynamical models of whole-brain activity dissociate between the level and stability of consciousness

Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant information about a given state of consciousness. While the level of consciousness can be taken to describe the actual brain state, a complete characterization should also include its potential behavior against external perturbations. We developed and analyzed whole-brain computational models to show that the stability of conscious states provides information complementary to their similarity to conscious wakefulness. Our work leads to a novel methodological framework to sort out different brain states by their stability and reversibility, and illustrates its usefulness to dissociate between physiological (sleep), pathological (brain-injured patients), and pharmacologically-induced (anesthesia) loss of consciousness.     

Diminution of photosynthesis in rice (Oryza sativa L.) seedlings under elevated CO2 concentration and increased temperature

The photosynthetic responses to elevated CO₂ concentration (EC) at ambient and ambient +4°C temperature were aßsessed in the second leaf of rice (Oryza sativa L.) seedlings. The duration of different leaf developmental phases, as characterised by changes in photosynthetic pigment contents and photochemical potential, was protracted in the seedlings grown under EC. On the other hand, a temporal shift in the phases of development with an early onset of senescence was observed in the seedlings grown under EC at ambient +4°C temperature. The contents of carotenoids, ß-carotene, and xanthophyll cycle pigments revealed that EC downregulated the protective mechanism of photosynthetic apparatus against oxidative damages, whereas this mechanism assumed higher significance under EC at ambient +4°C temperature. We observed an enhancement in electron transport activity, photochemical potential, and net photosynthesis in spite of a loss in photostasis of photosynthesis under EC. On the other hand, the loss in photostasis of photosynthesis was exacerbated under EC at ambient +4°C temperature due to the decline in electron transport activity, photochemical potential, and net photosynthesis.     

Dietary preference and feeding ecology of Bloch’s gizzard shad, <Emphasis Type="Italic">Nematalosa nasus</Emphasis>

Dietary preference and feeding ecology of Nematalosa nasus (Bloch 1795) in Chilika lagoon, India, was investigated through analysis of prey items in the guts and that in the habitat. Of the 230 taxa identified from the habitat in plankton samples from the lagoon, thirty five taxa were recorded from the guts of the fish. Index of Relative Importance showed 80% of the food comprised of microplankton groups viz. Foraminifera (35.79%), Chlorophyceae (20.52%), Bacillariophyaceae (12.30%), Cyanophyaceae (6.53%), other plant matter (3.65%) and Euglenophyaceae (0.76%). The fish is a generalized feeder on microplankton, with specialization on foraminiferans and Chlorophyaceae in Chilika Lagoon. Diet composition varied significantly with seasons. Prey type selectivity showed, preference to Gyrosigma sp. (α_i—0.98, e_i—0.85), Synedra sp. (α_i—0.47, e_i—0.71), Tabellaria sp. (α_i—0.58, e_i—0.47) and Ulothrix sp. (α_i—0.06, e_i—0.34) during monsoon and post-monsoonseason. Ammoniabeccarii (α_i—0.77 e_i—0.98), Campylodiscus sp. (α_i—0.04, e_i—0.17) and Microspora sp. (α_i—0.18, e_i—0.76), were selected during pre-monsoon period, which is also the peak breeding period of the fish.     

Length–weight relationships of six tropical fish species from Chilika Lagoon,India

The length weight relationships (LWRs) of six tropical fish species from Chilika Lagoon, India were studied. Specimens were caught using a wide range of fishing gear operated in the lagoon from January to December 2014. The fresh specimens were measured for total length and weight, then dissected and the sex confirmed. Previously unavailable in FishBase, the detailed LWRs of Daysciaena albida, Eleutheronema tetradactylum, Etroplus suratensis and Mystus gulio are reported for the first time. Maximum total lengths reported for Nematalosa nasus and Osteogeneiosus militaris in this study are new records for these species. The existence of a differential growth between male and female O. militaris was confirmed, which was not known earlier.     

Micropropagation of Semecarpus anacardium L. from mature tree-derived nodal explants

A protocol was established for micropropagation of Semecarpus anacardium L. from mature tree-derived twigs. Sixty percent of aseptic cultures were obtained by surface sterilization with Bavistin, liquid detergent, and cefotaxime. Elongated twigs collected before flowering were optimum for in vitro culture initiation. Meristematic activity was triggered at all concentrations of thidiazuron (TDZ) incorporated into Woody Plant Medium. TDZ suppressed elongation of axillary buds, resulting into swollen meristems and upon its elimination multiple shoot primordia formation and differentiation were noted. Differentiation and shoot elongation were slower in explants pre-cultured with higher concentrations of TDZ. Swollen axillary meristems pre-cultured on TDZ (9.08 and 13.62 μM) failed to differentiate, whereas TDZ at 2.27 μM was optimal for shoot differentiation and elongation. Multiple bud induction was favored by 4.45 μM of TDZ. Differentiation of multiple shoot primordia by repeated subculturing on growth regulator-free medium and rooting was 100% in filter-paper supported half-strength liquid medium containing 7.38 μM IBA. Rooting was 90% in shoots placed directly in half-strength liquid medium with 2.46 μM IBA. Rooted plantlets hardened in soil:sand mixture (1:1) were transferred to green house. Genetic uniformity of in vitro raised clones with mother plant was confirmed by Inter-Simple Sequence Repeat markers.     

Effects of Chromium Ore Tailings on Growth and Physiological Activities of Mesua ferrea L.

A greenhouse pot experiment was conducted to evaluate the feasibility of using a native ornamental plant, Mesua ferrea L. as phytostabilizer for chromium ore tailings (COT) and to assess the metal accumulation capacity. Different ratios of soil and COT were taken in pots and sowed with seeds of M. ferrea. Plants were harvested at various intervals and separated into roots and shoots for analysis of metal concentrations and physiological characteristics of the plants. The study revealed that the plant has great tolerance and stronger ability to accumulate Cr. The results suggested an increase in growth, chlorophyll content, antioxidant activities, as well as metal accumulation capacity of M. ferrea with increasing proportion of COT in the soil. This indicates the plant's efficiency to overcome any stress generated due to excess of chromium as well as other heavy metals. The order of accumulation of heavy metals was observed to be Fe>Cr>Ni>Cd>Co. The accumulation of Cr was higher in root compared to that in shoot. M. ferrea has found to be potential as a native species candidate for phytostabilization of chromium mine tailings.     

Rotenone inhibits mammalian cell proliferation by inhibiting microtubule assembly through tubulin binding

Rotenone, a widely used insecticide, has been shown to inhibit mammalian cell proliferation and to depolymerize cellular microtubules. In the present study, the effects of rotenone on the assembly of microtubules in relation to its ability to inhibit cell proliferation and mitosis were analyzed. We found that rotenone inhibited the proliferation of HeLa and MCF-7 cells with half maximal inhibitory concentrations of 0.2 +/- 0.1 microm and 0.4 +/- 0.1 microm, respectively. At its effective inhibitory concentration range, rotenone depolymerized spindle microtubules of both cell types. However, it had a much stronger effect on the interphase microtubules of MCF-7 cells compared to that of the HeLa cells. Rotenone suppressed the reassembly of microtubules in living HeLa cells, suggesting that it can suppress microtubule growth rates. Furthermore, it reduced the intercentrosomal distance in HeLa cells at its lower effective concentration range and induced multipolar-spindle formation at a relatively higher concentration range. It also increased the level of checkpoint protein BubR1 at the kinetochore region. Rotenone inhibited both the assembly and the GTP hydrolysis rate of microtubules in vitro. It also inhibited the binding of colchicine to tubulin, perturbed the secondary structure of tubulin, and reduced the intrinsic tryptophan fluorescence of tubulin and the extrinsic fluorescence of tubulin-1-anilinonaphthalene-8-sulfonic acid complex, suggesting that it binds to tubulin. A dissociation constant of 3 +/- 0.6 microm was estimated for tubulin-rotenone complex. The data presented suggest that rotenone blocks mitosis and inhibits cell proliferation by perturbing microtubule assembly dynamics.     

Aluminum stress signaling in plants

Aluminum (Al) toxicity is a major constraint for crop production in acidic soil worldwide. When the soil pH is lower than 5, Al³⁺ is released to the soil and enters into root tip cell ceases root development of plant. In acid soil with high mineral content, Al is the major cause of phytotoxicity. The target of Al toxicity is the root tip, in which Al exposure causes inhibition of cell elongation and cell division, leading to root stunting accompanied by reduced water and nutrient uptake. A variety of genes have been identified that are induced or repressed upon Al exposure. At tissue level, the distal part of the transition zone is the most sensitive to Al. At cellular and molecular level, many cell components are implicated in the Al toxicity including DNA in nucleus, numerous cytoplastic compounds, mitochondria, the plasma membrane and the cell wall. Although it is difficult to distinguish the primary targets from the secondary effects so far, understanding of the target sites of the Al toxicity is helpful for elucidating the mechanisms by which Al exerts its deleterious effects on root growth. To develop high tolerance against Al stress is the major goal of plant sciences. This review examines our current understanding of the Al signaling with the physiological, genetic and molecular approaches to improve the crop performance under the Al toxicity. New discoveries will open up new avenues of molecular/physiological inquiry that should greatly advance our understanding of Al tolerance mechanisms. Additionally, these breakthroughs will provide new molecular resources for improving the crop Al tolerance via molecular-assisted breeding and biotechnology.Key words: aluminum, toxicity, tolerance, signal transduction, plants     

Curcumin and tumor immune-editing: resurrecting the immune system

Curcumin has long been known to posses medicinal properties and recent scientific studies have shown its efficacy in treating cancer. Curcumin is now considered to be a promising anti-cancer agent and studies continue on its molecular mechanism of action. Curcumin has been shown to act in a multi-faceted manner by targeting the classical hallmarks of cancer like sustained proliferation, evasion of apoptosis, sustained angiogenesis, insensitivity to growth inhibitors, tissue invasion and metastasis etc. However, one of the emerging hallmarks of cancer is the avoidance of immune system by tumors. Growing tumors adopt several strategies to escape immune surveillance and successfully develop in the body. In this review we highlight the recent studies that show that curcumin also targets this process and helps restore the immune activity against cancer. Curcumin mediates several processes like restoration of CD4⁺/CD8⁺ T cell populations, reversal of type-2 cytokine bias, reduction of Treg cell population and suppression of T cell apoptosis; all these help to resurrect tumor immune surveillance that leads to tumor regression. Thus interaction of curcumin with the immune system is also an important feature of its multi-faceted modes of action against cancer. Finally, we also point out the drawbacks of and difficulties in curcumin administration and indicate the use of nano-formulations of curcumin for better therapeutic efficacy.