A Review of Elliptic Flow of Light Nuclei in Heavy-Ion Collisions at RHIC and LHC Energies

We present a review of the measurements of elliptic flow ($v_{2}$) of light nuclei ($d$,$\bar{d}$, $t$, $^{3}\rm He$, and $^{3}\overline{\rm He}$) from the RHIC and LHC experiments. Light (anti)nuclei $v_{2}$ have been compared with that of (anti)proton. We observed a similar trend in light nuclei $v_{2}$ to that in identified hadron $v_{2}$ with respect to the general observations such as ($p_{\rm T}$) dependence, low $p_{\rm T}$ mass ordering, and centrality dependence. We also compared the difference of nuclei and antinuclei $v_{2}$ with the corresponding difference of $v_{2}$ of proton and antiproton at various collision energies. Qualitatively they depict similar behavior. We also compare the data on light nuclei $v_{2}$ to various theoretical models such as blast-wave and coalescence. We then present a prediction of $v_{2}$ for $^{3}\rm He$ and $^{4}\rm He$ using coalescence and blast-wave models.Comment: 11 pages, 10 figure

The Production of Cauliflower Microshoots using Curd Meristematic Tissues and Hypocotyl–derived Callus.

The capacity for microshoot production from cauliflower was investigated applying two different protocols. In the first, cauliflower curd meristematic tissue was used as a source of explants. The meristematic layer was shaved off and the clusters produced were homogenised using a commercial blender. In terms of its effect on the number and viability of microshoots, the use of 30 s blending duration treatment was found to be optimal between several treatments tested in the range 15 to 120 sec. Explants were cultivated in agitated S23 (MS (Murashige and Skoog, 1962) + 3 % sucrose) liquid media supplemented with different combinations of plant growth regulators. The use of 2 mg/L kinetin and 1 mg/L IBA gave the optimal results in terms of the number and viability of microshoots. The second protocol was designed to investigate the regeneration potential of hypocotyl explants of cauliflower via callus culture. The callus tissue was initiated from hypocotyl explants in callus induction medium (CIM), which consisted of S23 supplemented with 2,4-D at 1 mg/L and kinetin at 1.5 mg/L. The highest number of shoots was obtained after 28 days from sub-cultured hypocotyl derived callus on S23 basal media containing 0.5 mg/L of kinetin. This study demonstrated the ability of producing microshoots using various parts of cauliflower through both callus and without callus formation which can be useful in the later applications of cauliflower tissue culture such as the production of artificial seeds

Elliptic and Triangular flow in asymmetric heavy-ion collisions

We present a study of the elliptic (v2) and triangular (v3) flow and their corresponding eccentricity fluctuations for asymmetric (Au+Ag, Au+Cu and Au+Si) collisions at \sqrt_NN = 200 GeV. These are compared to the corresponding results from symmetric (Au+Au and Cu+Cu) collisions at the same energy. The study which is carried out using a multi-phase transport (AMPT) model shows that triangularity (\epsilon_3), fluctuations in triangularity and v3 do not show much variation for the different colliding ion sizes studied. However the eccentricity (\epsilon_2), fluctuations in eccentricity and v2 shows a strong dependence on colliding ion size for a given number of participating nucleons. Our study thus indicates that asymmetric heavy-ion collisions could be used to constrain models dealing with flow fluctuations in heavy-ion collisions.Comment: 5 Pages, 12 Figures. Accepted for publication in Physical Review

Fluctuating initial condition and smoothening effect on elliptic and triangular flow

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. Generally, one uses Monte-Carlo Glauber model to obtain the participating nucleon positions. To use in a hydrodynamic model, the positions needs to be smoothened. We study the effect of smoothening of Glauber Monte-Carlo initial conditions on elliptic and triangular flow. It is shown that integrated as well as differential elliptic and triangular flow remain largely unaltered, irrespective of functional form of the smoothening function, or the smoothening parameterComment: 4 pages, 4 figure

Multiplicity, average transverse momentum and azimuthal anisotropy in U+U collisions at sNN\sqrt{s_{NN}} = 200 GeV using AMPT model

Using a multi-phase transport (AMPT) model that includes the implementation of deformed Uranium nuclei, we have studied the centrality dependence of the charged particle multiplicity, , eccentricity (e2), triangularity (e3), their fluctuations, elliptic flow (v2) and triangular flow (v3) for different configurations of U+U collisions at midrapidity for \sqrt(s_NN)=200 GeV. The results are compared to the corresponding observations from Au+Au collisions. We find that for the U+U collisions the dNch/d\eta at midrapidity is enhanced by about 15-40% depending on the collision and model configuration chosen, compared to Au+Au collisions. The tip-to-tip collisions leads to the largest values of Nch,transverse energy (ET) and . The and its fluctuation shows a rich centrality dependence, whereas not much variations are observed for and its fluctuations. The U+U side-on-side collision configuration provides maximum values of and minimum values of eccentricity fluctuations, whereas for peripheral collisions and mid-central collisions minimum values of and maximum value of eccentricity fluctuations are observed for body-to-body configuration and the tip-to-tip configuration has minimum value of and maximum value of eccentricity fluctuations for central collisions. The calculated v2 closely correlates with the eccentricity in the model. It is smallest for the body-to-body configuration in peripheral and mid-central collisions while it is minimum for tip-to-tip configuration in central collisions. For peripheral collisions the v2 in U+U can be about 40% larger than in Au+Au whereas for central collisions it can be a factor 2 higher depending on the collision configuration. It is also observed that the v3(pT) is higher for tip-to-tip and body-to-body configurations compared to other systems for the collision centrality studied.Comment: 10 pages and 29 figures. Accepted for publication in Physical Review

Germination of primed seed under NaCl stress in wheat.

Copyright © 2012 Michael P. Fuller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Soil salinity affects a large and increasing amount of arable land worldwide, and genetic and agronomic solutions to increasing salt tolerance are urgently needed. Experiments were conducted to improve wheat seed performance under salinity stress conditions after priming. An experiment was conducted using a completely randomized design of four replications for germination indices in wheat (Triticum aestivum L. cv. Caxton). Normal and primed seed with PEG6000 at −1MPa and five concentrations of NaCl (0, 50, 100, 150, and 200mM) were tested. Results indicate that priming seed significantly (P < 0.05) increased germination percentage at first count and final count, coefficient of velocity of germination, germination rate index, and mean germination time, while increasing of NaCl concentration significantly reduced it. Priming seed improved germination attributes at all NaCl concentration levels. The priming appeared to be able to overcome the effect of salt stress at 50 to 100mMand reduce the effect of NaCl at higher concentrations up to 200 mM. The primed seed gave both faster germination and led to higher germination when under salt stress. We conclude that using priming techniques can effectively enhance the germination seed under saline condition

Encapsulation of cauliflower (Brassica oleracea var botrytis) microshoots as artificial seeds and their conversion and growth in commercial substrates

An effective protocol for the mass production of cauliflower microshoots was refined using the meristematic layer of cauliflower curd. After the meristematic layer was surface sterilized and shaved off, a commercial blender was used for homogenization and several blending treatments were tested in the range 15-120 s and 30 s was found to be optimal in terms of the amount explants produced and their subsequent growth ability. Explants were cultivated in S23 liquid medium (4.4 g L-1 MS (Murashige and Skoog) and 3% v/w sucrose) supplemented with several combinations of plant growth regulators (PGRs) including 1 and 2 mg L-1 of Kinetin in combination with three types of auxins (indole butyric acid (IBA), Naphthaleneacetic acid (NAA) and Indole-3-acetic acid (IAA)), each at 1 and 2 mg L-1 concentration. The use of 2 mg L-1 Kinetin and 1 mg L-1 IBA gave the best results in terms of its effects on explant induction. Microshoots of different sizes were encapsulated in a sodium alginate matrix and the optimal stage suitable for the production of artificial seeds was assessed in terms of both subsequent conversion and plantlet viability. The feasibility of cultivating cauliflower artificial seeds in commercial substrates (compost, vermiculite, perlite and sand) irrigated with different solution mixtures including sterilized distilled water (SDW), PGRs-free S23 medium and S23 medium supplemented with Kinetin (1 and 2 mg L-1) and IBA or NAA at (1 and 2 mg L-1) was investigated. The use of 2 mg L-1 Kinetin and 2 mg L-1 NAA applied with S23 gave the optimal response with both perlite and compost. This study showed high growth capacity of cauliflower artificial seeds in commercial substrates which is considered a promising step for their direct use in vivo. © 2011 Springer Science+Business Media B.V