3,051 research outputs found
An experiment to test the hypothesis: "the medium by which information is presented to a subject has a direct effect on the number of ideas verbalized by the subject and the way the ideas are verbalized"
Thesis (M.S.)--Boston Universit
Reproduction of the entomopathogenic nematode Heterorhabditis bacteriophora Poinar, 1976 : hermaphroditism vs amphimixis
Sperm competition in mated first generation hermaphrodite females of the HP 88 strain of Heterorhabditis (Nematoda : Heterorhabditidae) and progeny sex ratios in mated and unmated females
Nous avons utilisé un mutant "obèse" pour étudier le processus de la fécondation chez #Heterorhabditis. Nous avons observé que, chez les femelles hermaphrodites de première génération inséminées, les spermatozoïdes provenant du mâle possèdent un avantage dans leur compétition avec les spermatozoïdes provenant de la femelle hermaphrodite elle-même. Les observations en microscopie optique ont montré qu'il n'y a pas de spermathèque chez les femelles hermaphrodites de première génération et que les spermatozoïdes introduits sont stockés dans la partie proximale de l'ovotestis où ils se mélangent avec les spermatozoïdes d'origine hermaphrodite. Les spermatozoïdes introduits ont des pseudopodes bien développés et paraissent plus actifs que les spermatozoïdes d'origine hermaphrodite. Les femelles amphimictiques de deuxième génération possèdent une spermathèque où sont stockés les spermatozoïdes introduits, et non dans la partie proximale de l'ovaire ou de l'utérus. La proportion des sexes dans la descendance croisée de femelles tant hermaphrodites qu'amphimictiques varie de 2,2 à 6,6 mâles pour mille descendants, chiffres très différents du rapport 1/1 qui aurait pu être attendu dans la descendance croisée de mâles hétérogamiques. Des mâles, en proportion 20 à 30 fois supérieure, ont été observés dans la descendance d'hermaphrodites autofécondés. Ainsi, l'origine des spermatozoïdes, suivant qu'ils proviennent de mâles ou d'individus hermaphrodites, influencent nettement la proportion des sexes de la descendance chez la souche HP 88 d'#Heterorhabditis. (Résumé d'auteur
Building a purposive approach to UK labour law
This thesis stresses the need for a reconceptualization of the judicial role in UK labour law. It will be argued that a purposive approach is the most appropriate approach for judges to take in this respect. Indeed, there has been an increasing willingness to use the purposive approach, using non-EU-derived legal sources, by the UK Supreme Court in labour law cases. It will be argued that a change in approach, as described, has the potential to redress the power imbalance in the employment relationship and mitigate the adverse effects progresses, with reference to the theories of Aharon Barak, Guy Davidov, Ronald Dworkin and labour law cases in the House of Lords and UK Supreme Court. The thesis will use this model to make a descriptive and normative assessment of how the UK Supreme Court should decide Uber v Aslam
The second-price auction solves King Solomon's dilemma
The planner wants to give k identical, indivisible objects to the top k
valuation agents at zero costs. Each agent knows her own valuation of the
object and whether it is among the top k. Modify the (k+1)st-price sealed-bid
auction by introducing a small participation fee and the option not to
participate in it. This simple mechanism implements the desired outcome in
iteratively undominated strategies. Moreover, no pair of agents can profitably
deviate from the equilibrium by coordinating their strategies or bribing each
other.Comment: 12 pages;To appear in Japanese Economic Revie
FLUORESCENCE AND CIRCULAR DICHROISM STUDIES ON THE PHYCOERYTHROCYANINS FROM THE CYANOBACTERIUM
Two phycoerythrocyanin (PEC) fractions have been obtained from the phycobilisomes of the cyanobac-terium Westiellopsis prolifica ARM 365. They have been characterized by absorption, fluorescence and circular dichroism spectroscopy. One of them is spectroscopically similar to a PEC trimer known from other organisms. Whereas efficient energy transfer from its violin (α-84) to the cyanin (β-84, 155) chromophores is efficient in the trimer (αβ it is impeded after dissociation to the monomer (α,β). A second fraction of PEC which we earlier termed PEC(X) (Maruthi Sai et al., Photochem. Photobiol. 55,119–124, 1992), exhibited the spectral properties similar to that of the α-subunit of PEC from Mastigocladus laminosus. With this highly photoactive fraction, the circular dichroism spectra of the violobilin chromophore in both photoreversible states were obtained
Picosecond time-resolved fluorescence of phycobiliproteins
The α- and β-subunits of C-phycocyanin from Mastigocladus laminosus were prepared according to revised procedures. Both subunits are isolated as dimers, which can be dissociated into monomers with detergent mixtures. The fluorescence decay kinetics are similar for the respective monomers and dimers. In no case could they be fitted by only one (α-subunit) or two exponentials (β-subunit) which are predicted by theory for samples with a unique chromophore—protein arrangement containing one and two chromophores, respectively. It is suggested that there exists a heterogeneity among the chromophores of the subunits, which may persist in the highly aggregated complexes present in cyanobacterial antennas
Finite-Difference Time-Domain Simulation for Three-dimensional Polarized Light Imaging
Three-dimensional Polarized Light Imaging (3D-PLI) is a promising technique
to reconstruct the nerve fiber architecture of human post-mortem brains from
birefringence measurements of histological brain sections with micrometer
resolution. To better understand how the reconstructed fiber orientations are
related to the underlying fiber structure, numerical simulations are employed.
Here, we present two complementary simulation approaches that reproduce the
entire 3D-PLI analysis: First, we give a short review on a simulation approach
that uses the Jones matrix calculus to model the birefringent myelin sheaths.
Afterwards, we introduce a more sophisticated simulation tool: a 3D Maxwell
solver based on a Finite-Difference Time-Domain algorithm that simulates the
propagation of the electromagnetic light wave through the brain tissue. We
demonstrate that the Maxwell solver is a valuable tool to better understand the
interaction of polarized light with brain tissue and to enhance the accuracy of
the fiber orientations extracted by 3D-PLI.Comment: 13 pages, 5 figure
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