EFFECT ON BOLL WEIGHT OF COTTON PLANTS PLANTED AT VARIOUS DENSITIES

Previous research has shown that yield of cotton increases with plant density until density reaches 16 to 20 plants m-2. In 1997 and 1998 cotton was planted at various densities ranging from 2.5 to 22.5 plants m-2 in a RCB design. Ten row feet (3.048 m) of cotton were cut at ground level in each plot and placed into separate bags. Plant density for each plot was found by counting the number of plants in the bag representing that plot. For each plant, a boll found was placed in a small bag representing the fruiting branch and position from which it had been taken. A token was placed in the compartment which contained this bag. Any position without a harvestable boll was recorded as zero. Each small bag was weighed (total boll weight) and number of bolls were determined from count of tokens thus providing mean boll weight. Mixed model analyses were performed on total yield, mean boll weight, and percent harvestable bolls: however, only mean boll weight will be presented. A response surface was determined for fruiting position by plant density

Plant height and seed yield of castor (Ricinus communis L.) sprayed with growth retardants and harvest aid chemicals.

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Triple coalescence singularity in a dynamical atomic process

We show that the high energy limit for the amplitude of the double electron capture to the bound state of the Coulomb field of a nucleus with emission of a single photon is determined by behavior of the wave function in the vicinity of the singular triple coalescence point.Comment: 3 page

Comparing the effect of CTG+STan with CTG alone on emergency Cesarean section rate : STan Australian Randomized controlled Trial (START)

The authors would like to thank the women and their babies for participating. We would like to thank all the staff at the WCH, in particular Priya Umampathysivam, Denise Cheetham and Cecilia Heitmann for their assistance in recruitment of participants for START. We would also like to thank the members of the DSMC, Diogo Ayres-de-Campos, Scott Morris and Katherine Lee, for their oversight of START and the Clinical Information Service (CIS) team at the WCH for the comparative hospital dataPeer reviewedPublisher PD

In vivo cell tracking with 52Mn PET: Targetry, Separation, and Applications

Introduction 52Mn (t½ =5.59 d, β+ = 29.6%, Eβmax = 0.58 MeV) has great potential as a long lived PET isotope for use in cell tracking studies, observation of immunologic response to disease states, or as an alternative to manganese-based MRI contrast agents. Its favorable max positron energy leads to superb imaging resolution, comparable to that of 18F.[1] Manganese is naturally taken up by cells via a multitude of pathways including the divalent metal transporter (DMT1), ZIP8, transferrin receptors (TfR), store-operated Ca2+ channels (SOC-Ca2+), and ionotropic glutamate receptor Ca2+ channels (GluR).[2] These natural transport mechanisms make 52Mn an attractive isotope for applications necessitating non-perturbative cell uptake. In particular, cell tracking is critical to the development and translation of stem cell therapies in regenerative medicine. Alternative-ly, 52Mn could be used in immunotherapy techniques such as adoptive cellular therapy (ACT) to evaluate the ability of external immune cells to reach their intended target. Material and Methods 52Mn was produced by natCr(p,x)52Mn using 16 MeV protons. The average thick target production yield was 0.23 mCi/µA-h with less than 0.25% co-production of 54Mn. Small amounts of 51Cr were observed in the target, but were absent from the radiochemically separated product. Target construction consisted of a water jet cooled chromium disc (3/4” diameter, 0.4” thick). Targets were purchased from Kamis Inc, and are 99.95% pure. Targets withstood beam currents of 30 µA with no visible aberration. Chromium targets were etched by concentrated HCl following bombardment. Mn2+ ions were extracted from 9M HCl to 0.8M trioctylamine in cyclohexane leaving the bulk chromium in the aqueous phase. After isolating the organic phase, 0.001M NH4OH was used to back-extract the Mn2+ ions to aqueous phase. This purification cycle was conducted a total of three times for each 52Mn production. Results and Conclusion For a starting bulk chromium mass of 456 ± 1 mg, a post-separation chromium mass of 5.35 ± 0.04 ng was measured by microwave plasma atomic emission spectrometry (MP-AES). This mass reduction corresponds to an average separation factor of 440 for a single purification cycle. Each purification cycle had a 52Mn recovery efficiency of 73 ± 7 % (n = 6), resulting in an overall separation efficiency of approximately 35 %. These efficiencies and separation factors agree reasonably well with the work conducted by Lahiri et. al.[3] Prior to use, the product was passed through a C-18 Sep-Pak to remove any residual organic phase. After four target irradiations and etchings, some pitting became noticeable on the target face. These have not yet compromised the o-ring seal with the target deplater, but it is possible that target replacement after every 6–9 52Mn productions will be necessary moving forward. Following the successful separation of 52Mn from chromium, in vitro experiments were conducted to demonstrate the uptake of 52Mn by human stem cells and mouse tumor cells. A linear uptake response was observed as a function of the amount of activity exposed to the cells for both cell models. These experiments have shown great promise for 52Mn as a long-lived PET isotope in cell tracking studies. Details will be presented

The theory of pulsar winds and nebulae

We review current theoretical ideas on pulsar winds and their surrounding nebulae. Relativistic MHD models of the wind of the aligned rotator, and of the striped wind, together with models of magnetic dissipation are discussed. It is shown that the observational signature of this dissipation is likely to be point-like, rather than extended, and that pulsed emission may be produced. The possible pulse shapes and polarisation properties are described. Particle acceleration at the termination shock of the wind is discussed, and it is argued that two distinct mechanisms must be operating, with the first-order Fermi mechanism producing the high-energy electrons (above 1 TeV) and either magnetic annihilation or resonant absorption of ion cyclotron waves responsible for the 100 MeV to 1 TeV electrons. Finally, MHD models of the morphology of the nebula are discussed and compared with observation.Comment: 33 pages, to appear in Springer Lecture Notes on "Neutron stars and pulsars, 40 years after the discovery", ed W.Becke

Photohadronic Neutrinos from Transients in Astrophysical Sources

We investigate the spectrum of photohadronically produced neutrinos at very high energies (VHE, >10^14 eV) in astrophysical sources whose physical properties are constrained by their variability, in particular jets in Active Galactic Nuclei (blazars) and Gamma-Ray Bursts (GRBs). We discuss in detail the various competing cooling processes for energetic protons, as well as the cooling of pions and muons in the hadronic cascade, which impose limits on both the efficiency of neutrino production and the maximum neutrino energy. If the proton acceleration process is of the Fermi type, we can derive a model independent upper limit on the neutrino energy from the observed properties of any cosmic transient, which depends only on the assumed total energy of the transient. For standard energetic constraints, we can rule out major contributions above 10^19 eV from current models of both blazars and GRBs; and in most models much stronger limits apply in order to produce measurable neutrino fluxes. For GRBs, we show that the cooling of pions and muons in the hadronic cascade imposes the strongest limit on the neutrino energy, leading to cutoff energies of the electron and muon neutrino spectrum at the source differing by about one order of magnitude. We also discuss the relation of maximum cosmic ray energies to maximum neutrino energies and fluxes in GRBs, and find that the production of both the highest energy cosmic rays and observable neutrino fluxes at the same site can only be realized under extreme conditions; a test implication of this joint scenario would be the existence of strong fluxes of GRB correlated muon neutrinos up to ultra high energies, >10^17 eV. Secondary particle cooling also leads to slightly revised estimates for the neutrino fluxes from (non-transient) AGN cores.Comment: Significant corrections and changes in presentation, no changes in the result. Symbol table added. REVTeX, 30 pages, 2 embedded figure

Visualizing Escherichia coli Sub-Cellular Structure Using Sparse Deconvolution Spatial Light Interference Tomography

Studying the 3D sub-cellular structure of living cells is essential to our understanding of biological function. However, tomographic imaging of live cells is challenging mainly because they are transparent, i.e., weakly scattering structures. Therefore, this type of imaging has been implemented largely using fluorescence techniques. While confocal fluorescence imaging is a common approach to achieve sectioning, it requires fluorescence probes that are often harmful to the living specimen. On the other hand, by using the intrinsic contrast of the structures it is possible to study living cells in a non-invasive manner. One method that provides high-resolution quantitative information about nanoscale structures is a broadband interferometric technique known as Spatial Light Interference Microscopy (SLIM). In addition to rendering quantitative phase information, when combined with a high numerical aperture objective, SLIM also provides excellent depth sectioning capabilities. However, like in all linear optical systems, SLIM's resolution is limited by diffraction. Here we present a novel 3D field deconvolution algorithm that exploits the sparsity of phase images and renders images with resolution beyond the diffraction limit. We employ this label-free method, called deconvolution Spatial Light Interference Tomography (dSLIT), to visualize coiled sub-cellular structures in E. coli cells which are most likely the cytoskeletal MreB protein and the division site regulating MinCDE proteins. Previously these structures have only been observed using specialized strains and plasmids and fluorescence techniques. Our results indicate that dSLIT can be employed to study such structures in a practical and non-invasive manner