Effective one-component description of two-component Bose-Einstein condensate dynamics

We investigate dynamics in two-component Bose-Einstein condensates in the context of coupled Gross-Pitaevskii equations and derive results for the evolution of the total density fluctuations. Using these results, we show how, in many cases of interest, the dynamics can be accurately described with an effective one-component Gross-Pitaevskii equation for one of the components, with the trap and interaction coefficients determined by the relative differences in the scattering lengths. We discuss the model in various regimes, where it predicts breathing excitations, and the formation of vector solitons. An effective nonlinear evolution is predicted for some cases of current experimental interest. We then apply the model to construct quasi-stationary states of two-component condensates.Comment: 8 pages, 4 figure

Tunneling of a Quantized Vortex: Roles of Pinning and Dissipation

We have performed a theoretical study of the effects of pinning potential and dissipation on vortex tunneling in superconductors. Analytical results are obtained in various limits relevant to experiment. In general we have found that pinning and dissipation tend to suppress the effect of the vortex velocity dependent part of the Magnus force on vortex tunneling.Comment: Latex, 12 page

Effect of subsequent storage of tuberose (Polianthes tuberosa L.) bulbs after low temperature pre - treatment improves growth, percent sprouting and cut flower quality

During peak planting time in commercial tuberose cut flower production lack of seed materials occasionally occur. Most producers also source planting materials which have not been adequately stored resulting in poor performance of the crop. For improved productivity in tuberose cut flower value chain, ways of increasing the availability of planting materials and improving the growth performance need attention. This study examined the effects of subsequent warm temperature storage after low temperature treatment of tuberose bulbs on growth, sprouting and flower quality. The experiment was laid in a split plot arrangement in a completely randomized design. Tuberose bulbs were stored in a biotron at 5ºC or 10ºC for 3 months with subsequent temperature storage of 20ºC for 0, 2, 4 or 6 weeks. The main effects were pre‐treatment temperatures at 5 or 10ºC, whilst subsequent temperature storage treatments constituted the sub‐effects. Days to sprouting were significantly earlier ( 14.9) when tuberose bulbs were pretreated at 10ºC followed by 20ºC subsequent temperature storage for 6 weeks compared to 51.1 at 5ºC pretreatment with no subsequent temperature storage. The highest percent sprouting (99.2%) was obtained with 10ºC pretreatment followed by 20ºC thawing for 6 weeks. Pre‐treating tuberose bulbs at either 5ºC or 10ºC then planting directly resulted in 69.3% and 88.3% sprouting, respectively, whilst similar pretreatments resulted in 70.0% and 81.2% flowering. The number of days to flowering were significantly (P<0.05 ) reduced (110.8) at 10ºC pre‐treatment followed by 20ºC subsequent thawing for 6 weeks compared to 143.1 at 5ºC pretreatment with no thawing respectively. Stem length of inflorescences significantly (P<0.05) improved to 106.8 cm at 10ºC with thawing at 20ºC for 6 weeks compared to 98.2 cm at 5ºC pretreatment and no thawing respectively. Number of florets per spike also significantly (P<0.05) increased to 42.4 compared to 34.9 for similar treatments. Storage of tuberose bulbs at low temperatures followed by warm subsequent storage for 2, 4 or 6 weeks besides improving sprouting and quality of flowers could enhance the availability of planting materials for crop production. The planting materials could be bulked with possibility of commercial exploitation.Key words: Flower quality, growth, low temperature storage, sprouting, tuberosebulb

Pollution impact of cement production on air, soil and water in a production location in Nigeria

Environmental pollution caused by the activities of Ewekoro Cement production facility of the West African Portland Cement (WAPC, Plc), Ogun State, Nigeria was studied at some terrestrial and aquatic receptor locations within the catchments area of the production plant which hasbeen in operation for over 40years. Air, water and soil samples of the adjoining villages (Ajobiewe, Olapeleke, Alaguntan and Wasinmi) were analyzed. High particulate matter depositions were recorded for all the sampling locations. Dusts emitted from the cement factory wererich in heavy metals. Heavy metals concentration at Ajobiewe, Olapeleke and Alaguntan were significantly (pNi>Fe>Cr>Zn>Cu>Co>Pb>Cd. Heavy metals concentrations were significantly different (

A multi-protein receptor-ligand complex underlies combinatorial dendrite guidance choices in C. elegans.

Ligand receptor interactions instruct axon guidance during development. How dendrites are guided to specific targets is less understood. The C. elegans PVD sensory neuron innervates muscle-skin interface with its elaborate dendritic branches. Here, we found that LECT-2, the ortholog of leukocyte cell-derived chemotaxin-2 (LECT2), is secreted from the muscles and required for muscle innervation by PVD. Mosaic analyses showed that LECT-2 acted locally to guide the growth of terminal branches. Ectopic expression of LECT-2 from seam cells is sufficient to redirect the PVD dendrites onto seam cells. LECT-2 functions in a multi-protein receptor-ligand complex that also contains two transmembrane ligands on the skin, SAX-7/L1CAM and MNR-1, and the neuronal transmembrane receptor DMA-1. LECT-2 greatly enhances the binding between SAX-7, MNR-1 and DMA-1. The activation of DMA-1 strictly requires all three ligands, which establishes a combinatorial code to precisely target and pattern dendritic arbors

Internal Vortex Structure of a Trapped Spinor Bose-Einstein Condensate

The internal vortex structure of a trapped spin-1 Bose-Einstein condensate is investigated. It is shown that it has a variety of configurations depending on, in particular, the ratio of the relevant scattering lengths and the total magnetization.Comment: replacement; minor grammatical corrections but with additional figure

Nanodelivery of a functional membrane receptor to manipulate cellular phenotype.

Modification of membrane receptor makeup is one of the most efficient ways to control input-output signals but is usually achieved by expressing DNA or RNA-encoded proteins or by using other genome-editing methods, which can be technically challenging and produce unwanted side effects. Here we develop and validate a nanodelivery approach to transfer in vitro synthesized, functional membrane receptors into the plasma membrane of living cells. Using β2-adrenergic receptor (β2AR), a prototypical G-protein coupled receptor, as an example, we demonstrated efficient incorporation of a full-length β2AR into a variety of mammalian cells, which imparts pharmacologic control over cellular signaling and affects cellular phenotype in an ex-vivo wound-healing model. Our approach for nanodelivery of functional membrane receptors expands the current toolkit for DNA and RNA-free manipulation of cellular function. We expect this approach to be readily applicable to the synthesis and nanodelivery of other types of GPCRs and membrane receptors, opening new doors for therapeutic development at the intersection between synthetic biology and nanomedicine