Effect of growth regulators and Physiological Gradients on the High frequency plant regeneration from the long-term callus cultures of different germplasms of Rice (Oryza sativa L.)

Callus cultures of rice were initiated from mature embryos of different cultivars on LS medium containing 2 mg/L 2,4-D. Increasing concentrations of 2,4-D and 2,4-5T also increased the frequency of callus initiation in all the cultivars tested. Of different cultivars, Tellahamsa was found to be superior for callus initiation. Genotypic differences for plant regeneration were also observed. Cultivar Tellahamsa showed the highest (65-75%) frequency of plant differentiation followed by DGWG, Yerragaluvadlu, Surekha, Basmati-370, Bala, Chakko amubi, Jaya and IR-8. Callus cultures of rice cultivar Bala grown on a shoot-forming medium (LS + 1 mg/L IAA + 4 mg/L KN + 2% sucrose) were exposed to gibberellic acid and abscisic acid for varying lengths of time and at different periods during culture. Gibberellic acid totally suppressed the organogenesis in callus cultures of rice. The results suggest that if the tissue accumulated sufficient gibberellic acid prior to the initiation of meristemoids and shoot primordia, repression of shoot formation occurred. This repression was not reversed by increasing the levels of IAA and KN in the medium, but abscisic acid could partially overcome the gibberellic acid repression of shoot formation in rice callus. It has been observed in rice that shoots usually emerge from the basal portions of callus. This observation suggested that perhaps physiological gradients of materials were operative during the organ initiation process. To test this hypothesis, starch content and the enzyme activity of malate dehydrogenase in upper and lower portions of shoot-forming and non-shoot-forming callus were determined. Starch began to accumulate in both upper and lower portions of the shoot forming tissues within 4 days of culture. The rate of accumulation however, was faster and more in the lower portion of the callus leading to a peak of accumulation on day 8 in culture, i.e., prior to shoot formation. Non-shoot-forming callus cultures accumulated little starch during the same period of culture. Malate dehydrogenase (MDH) activity was examined in order to know the overall rate of respiration. In the upper segment of shoot-forming callus, the activity of MDH was very high by day 4 but declined continuously thereafter. The rate of activity of the enzyme was significantly higher beyond four days in culture in case of the lower portion of the shoot forming callus. Enzyme activity was lower in the non-shoot-forming portions (both upper and lower) of the callus. The higher rate of enzyme activity for the upper portion of the tissue could be attributed to increased oxygen availability. Thus, the evidence for the idea that concentrations of gradients or physiological gradients of substances into the callus tissue may be the operative factors promoting organ initiation in vitro is presented

Utilization of phosphorus for casein biosynthesis in the mammary gland. II. Incorporation of P<SUP>32</SUP> into free phosphopeptides of milk and of mammary gland

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Novel titanium - hydroxyapatite biocomposites By mechanical milling

Titanium with nano hydroxyapatite (nHA) as well as with micron size hydroxyapatite was ball milled for various time intervals. The milled powders were characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The XRD results show peak broadening with increase in milling time indicating the formation of nanocomposite with titanium and HA phases. Relatively, titanium was found to be more reduced in size with increase in milling time than HA in the composite. The EDX results indicated the presence of Ca and P in the titanium matrix. elemental mapping showed homogeneous distribution of Ti, Ca and P after 16 h of ball milling in all the composites. TEM micrographs also revealed the presence of nanocrystals. The powders were compacted, sintered and immersed in simulated body fluid (SBF), which has the same ion concentration as that of the human body plasma, to study bioactivity under physiological condition. After immersion in SBF for 1 week, the compacts were observed in SEM and all the composites were found to be bioactive with the formation of bone like apatite layer on the surface. The morphology of the apatite formed was globular and more dense for the composite prepared using nano HA compared to micron size HA

Evaluation of periphyton quantity on different natural substrates in Earthen lined pond

Experiments were conducted in outdoor earthen lined pond to study periphyton quantity on three types of natural substrates such as split bamboo pole, coconut coir and coconut shell, which was placed inside the earthen lined pond filled with seawater for duration of 45 days. Observations were made in every 15th day for growth of periphyton both qualitatively and quantitatively on the three natural substrates and physico-chemical properties of selected pond water such as transparency, water temperature, salinity, pH, Dissolved oxygen, Ammonia (NH3-N), Nitrite (NO2-N), Nitrate (NO3-N), BOD and Chlorophyll ‘a’ were recorded during periphyton samplings. The periphy-ton quantity (34562 ± 671 cells / cm2) observed for coconut coir was higher than the split bamboo pole (33104 ± 810 cells / cm2), and coconut shell (21194 ± 872 cells / cm2) in the final day of the experiment. One way ANOVA of the data collected clearly affirmed that significant differences were observed (P &lt; 0.05) in periphyton quantity among the three substrates tested. A total 16 phyto-periphytic microalgae (Bacillariophyceae – 10 types, Dinophyceae – 4 types and Cyanophyceae – 2 types) and 10 Zoo-periphyton (Copepod- 4 types, Meroplankton – 4 types and Tintin-nidae – 2 types) were recorded from these three substrates. Among the different phyto-periphytic microalgae, Bacil-lariophyceae group were found to be more (Split bamboo pole – 72%, Coconut coir – 73% and Coconut shell – 71%) on three substrates studied. Further, coconut coir was found to be best substrate than split bamboo pole and coconut shell, which can be utilized by fin and shellfishes as natural food

A test architecture design for SoCs using ATAM method

Test arranging is a basic issue in structure on-a-chip (S.O.C) experiment mechanization. Capable investigation designs constrain the general organization check request time, keep away from analysis reserve conflicts, in addition to purpose of restriction control disseminating in the midst of examination manner. In this broadsheet, we absent a fused method to manage a couple of test arranging issues. We first present a system to choose perfect timetables for sensibly evaluated SOC’s among need associations, i.e., plans that spare alluring orderings among tests. This furthermore acquaints a capable heuristic estimation with plan examinations designed for enormous S.O.Cs through need necessities in polynomial occasion. We portray a narrative figuring with the purpose of uses pre-emption of tests to secure capable date-books in favour of SOCs. Exploratory marks on behalf of an educational S-O-C plus a cutting edge SOC exhibit with the aim of capable investigation timetables be able to subsist gained in sensible CPU occasion

Assessment of Antisocial Behaviour in the Juveniles

Background: High level of crime, particularly by the people below 18 years, has been a matter of concern for many years. Assessing and preventing the antisocial behaviour in juveniles has become a policy priority.Methods: A cross sectional study was conducted on 52 males less than 18 years in an observation home in Bangalore, India. The data was collected in an interview by filling a semi structured questionnaire. Revised Wisconsin Delinquency Risk Assessment Scale (RWDRAS) was filled up simultaneously and then results were analysed.Results: Majority of the offenders were in the age group 16-18 years. In the majority the cause for antisocial behaviour was unknown followed by the family problems and poverty. The RWDRAS identified 47% of the juveniles with antisocial behaviour as low risk group.Conclusion: The Education, counselling and prevention of poverty are some of the preventive measures of antisocial behaviour. There is a need to develop a better criteria and scale for the diagnosis of antisocial behaviour as the presently used RWDRAS failed in 47% of the juveniles

Emergence and patterning dynamics of mouse-definitive endoderm

The segregation of definitive endoderm (DE) from bipotent mesendoderm progenitors leads to the formation of two distinct germ layers. Dissecting DE commitment and onset has been challenging as it occurs within a narrow spatiotemporal window in the embryo. Here, we employ a dual Bra/Sox17 reporter cell line to study DE onset dynamics. We find Sox17 expression initiates in vivo in isolated cells within a temporally restricted window. In 2D and 3D in vitro models, DE cells emerge from mesendoderm progenitors at a temporally regular, but spatially stochastic pattern, which is subsequently arranged by self-sorting of Sox17 + cells. A subpopulation of Bra-high cells commits to a Sox17+ fate independent of external Wnt signal. Self-sorting coincides with upregulation of E-cadherin but is not necessary for DE differentiation or proliferation. Our in vivo and in vitro results highlight basic rules governing DE onset and patterning through the commonalities and differences between these systems

Magneto-optics of massive Dirac fermions in bulk Bi2Se3

We report on magneto-optical studies of Bi2Se3, a representative member of the 3D topological insulator family. Its electronic states in bulk are shown to be well described by a simple Dirac-type Hamiltonian for massive particles with only two parameters: the fundamental bandgap and the band velocity. In a magnetic field, this model implies a unique property - spin splitting equal to twice the cyclotron energy: Es = 2Ec. This explains the extensive magneto-transport studies concluding a fortuitous degeneracy of the spin and orbital split Landau levels in this material. The Es = 2Ec match differentiates the massive Dirac electrons in bulk Bi2Se3 from those in quantum electrodynamics, for which Es = Ec always holds.Comment: 5 pages, 3 figures and Supplementary materials, to be published in Physical Review Letter

GATA transcription factors drive initial Xist upregulation after fertilization through direct activation of a distal enhancer element

To ensure dosage compensation for X-linked genes between the sexes, one X chromosome is silenced during early embryonic development of female mammals. This process of X-chromosome inactivation (XCI) is initiated through upregulation of the RNA Xist from one X chromosome shortly after fertilization. Xist then mediates chromosome-wide gene silencing in cis and remains expressed in all cell types except the germ line and the pluripotent state, where XCI is reversed. The factors that drive Xist upregulation and thereby initiate XCI remain however unknown. We identify GATA transcription factors as potent Xist activators and demonstrate that they are essential for the activation of Xist in mice following fertilization. Through a pooled CRISPR activation screen we find that GATA1 can drive ectopic Xist expression in murine embryonic stem cells (mESCs). We demonstrate that all GATA factors can activate Xist directly via a GATA-responsive regulatory element (RE79) positioned 100 kb upstream of the Xist promoter. Additionally, GATA factors are essential for the induction of XCI in mouse preimplantation embryos, as simultaneous deletion of three members of the GATA family (GATA1/4/6) in mouse zygotes effectively prevents Xist upregulation. Thus, initiation of XCI and possibly its maintenance in distinct lineages of the preimplantation embryo is ensured by the combined activity of different GATA family members, and the absence of GATA factors in the pluripotent state likely contributes to X reactivation. We thus describe a form of regulation in which the combined action of numerous tissue-specific factors can achieve near-ubiquitous expression of a target gene