The cell lineage of the muscles of the Drosophila head

Using a cell marker mutation the cell lineage of the muscles of the Drosophila head are traced out. Three sets of muscles separated by lineage restrictions are observed, even when cells are marked as early as the blastoderm stage. Each set underlies the derivatives of one of the three pairs of imaginal discs which differentiate to form the epidermis of the adult head. Clones of the homoeotic mutation engrailed (en^10) were apparently normal in the muscles of the head. The muscle clone frequency, at the blastoderm stage, in each hemisegment of the fly is similar, indicating an equal partitioning of cells during segmentation

Stopping Sexual Harassment in the Empire State: Past, Present, and a Possible Future

This report maps current patterns of workplace sexual harassment and their impact in New York State. It also provides a broader frame for understanding how efforts to confront sexual and gender-based harassment and assault have evolved over time, and charts possible directions for future organizing, policy, and research in New York and beyond. The findings presented here are drawn from the 2018 Empire State Poll, an annual statewide survey of 800 New Yorkers conducted by the Cornell Survey Research Institute. Questions added to the survey reflecting existing legal definitions of workplace sexual harassment reveal the following: 10.9 percent of New York residents have experienced quid pro quo workplace sexual harassment, and 21.9 percent have experienced workplace sexual harassment that created a hostile work environment; 31.1 percent of women and 18.9 percent of men have experienced at least one of these forms of harassment. 13.9 percent of people of color and people of Hispanic origin have experienced quid pro quo workplace sexual harassment, as opposed to 8.5 percent of non-Hispanic whites. 38.9 percent of those experiencing at least one form of workplace sexual harassment say it impacted their work or careers; 48.9 percent who experienced quid pro quo harassment reported such an impact. 83.4 percent of New York residents think their leaders should do more to address workplace sexual harassment. There is notable variation by politics and ideology, but regardless of worldview, strong majorities think leaders should do more. In addition to sharing the survey findings, the report discusses experiences and responses of survivors and how they are shaped by different identities and relations of power. It highlights black women’s leadership in propelling wide-reaching shifts in law and culture; efforts initiated by diverse survivors to effect change in specific industries; and culture change work engaging men and women as allies

A phenomenological model for magnetoresistance in granular polycrystalline colossal magnetoresistive materials: the role of spin polarised tunnelling at the grain boundaries

It has been observed that in bulk and polycrystalline thin films of collossal magnetoresistive (CMR) materials the magnetoresistance follows a different behaviour compared to single crystals or single crystalline films below the ferromagnetic transition temperature Tc. In this paper we develop a phenomenological model to explain the magnetic field dependence of resistance in granular CMR materials taking into account the spin polarised tunnelling at the grain boundaries. The model has been fitted to two systems, namely, La0.55Ho0.15Sr0.3MnO3 and La1.8Y0.5Ca0.7Mn2O7. From the fitted result we have separated out, in La0.55Ho0.15Sr0.3MnO3, the intrinsic contribution from the intergranular contribution to the magnetoresistance coming from spin polarised tunnelling at the grain boundaries. It is observed that the temperature dependence of the intrinsic contribution to the magnetoresistance in La0.55Ho0.15Sr0.3MnO3 follows the prediction of double exchange model for all values of field.Comment: 14 pages + 5 figures, postscript (to appear in Journal of Applied Physics

Argumentation schemes for collaborative planning

Postprin

Thermal and non-thermal emission from reconnecting twisted coronal loops

Twisted magnetic fields should be ubiquitous in flare-producing active regions where the magnetic fields are strongly non-potential. It has been shown that reconnection in helical magnetic coronal loops results in plasma heating and particle acceleration distributed within a large volume, including the lower coronal and chromospheric sections of the loops. This scenario can be an alternative to the standard flare model, where particles are accelerated only in a small volume located in the upper corona. We use a combination of MHD simulations and test-particle methods, which describe the development of kink instability and magnetic reconnection in twisted coronal loops using resistive compressible MHD, and incorporate atmospheric stratification and large-scale loop curvature. The resulting distributions of hot plasma let us estimate thermal X-ray emission intensities. The electric and magnetic fields obtained are used to calculate electron trajectories using the guiding-centre approximation. These trajectories combined with the MHD plasma density distributions let us deduce synthetic HXR bremsstrahlung intensities. Our simulations emphasise that the geometry of the emission patterns produced by hot plasma in flaring twisted coronal loops can differ from the actual geometry of the underlying magnetic fields. The twist angles revealed by the emission threads (SXR) are consistently lower than the field-line twist present at the onset of the kink-instability. HXR emission due to the interaction of energetic electrons with the stratified background are concentrated at the loop foot-points in these simulations, even though the electrons are accelerated everywhere within the coronal volume of the loop. The maximum of HXR emission consistently precedes that of SXR emission, with the HXR light-curve being approximately proportional to the temporal derivative of the SXR light-curve.Comment: (accepted for publication on A&A

Multilevel Preconditioning of Discontinuous-Galerkin Spectral Element Methods, Part I: Geometrically Conforming Meshes

This paper is concerned with the design, analysis and implementation of preconditioning concepts for spectral Discontinuous Galerkin discretizations of elliptic boundary value problems. While presently known techniques realize a growth of the condition numbers that is logarithmic in the polynomial degrees when all degrees are equal and quadratic otherwise, our main objective is to realize full robustness with respect to arbitrarily large locally varying polynomial degrees degrees, i.e., under mild grading constraints condition numbers stay uniformly bounded with respect to the mesh size and variable degrees. The conceptual foundation of the envisaged preconditioners is the auxiliary space method. The main conceptual ingredients that will be shown in this framework to yield "optimal" preconditioners in the above sense are Legendre-Gauss-Lobatto grids in connection with certain associated anisotropic nested dyadic grids as well as specially adapted wavelet preconditioners for the resulting low order auxiliary problems. Moreover, the preconditioners have a modular form that facilitates somewhat simplified partial realizations. One of the components can, for instance, be conveniently combined with domain decomposition, at the expense though of a logarithmic growth of condition numbers. Our analysis is complemented by quantitative experimental studies of the main components.Comment: 41 pages, 11 figures; Major revision: rearrangement of the contents for better readability, part on wavelet preconditioner adde

A 'p-n' diode with hole and electron-doped lanthanum manganite

The hole-doped manganite La0.7Ca0.3MnO3 and the electron-doped manganite La0.7Ce0.3MnO3 undergo an insulator to metal transition at around 250 K, above which both behave as a polaronic semiconductor. We have successfully fabricated an epitaxial trilayer (La0.7Ca0.3MnO3/SrTiO3/La0.7Ce0.3MnO3), where SrTiO3 is an insulator. At room temperature, i.e. in the semiconducting regime, it exhibits asymmetric current-voltage (I-V) characteristics akin to a p-n diode. The observed asymmetry in the I-V characteristics disappears at low temperatures where both the manganite layers are metallic. To the best of our knowledge, this is the first report of such a p-n diode, using the polaronic semiconducting regime of doped manganites.Comment: PostScript text and 2 figures, to be published in Appl. Phys. Lett