Search results for "Mali"
showing 10 items of 3900 documents
Hymenoptera Chalcidoidea inhabiting galls of Cynipidae in Jordan
2008
Twenty-three species of Chalcidoidea (5 Eurytomidae, 4 Torymidae, 2 Ormyridae, 5 Pteromalidae and 7 Eulophidae) are recorded as regular members of the parasitoid fauna inhabiting galls of Cynipidae in Jordan. The occurrence of three additional species, probably only facultatively associated with cynipid galls, is noted. Twenty-two out of the total 26 species were previously unrecorded in the country, while 13 of them are also new for the entire Middle East. Eighteen new host records were detected, together with 24 new plant-parasitoid associations. The biology of each species is briefly commented upon, as well as the presence of a host-related colour variation in some species.
Trace element systematics of tourmaline in pegmatitic and hydrothermal systems from the Variscan Schwarzwald (Germany): The importance of major eleme…
2013
article An extensive data set on the compositional variation of tourmaline from granitic pegmatites, from migmatitic gneisses and from various types of hydrothermal veins from the Schwarzwald, Germany, is provided. The investigated tourmalines are members of the alkali and X-vacant groups representing mostly dravite- schorl solid solutions with some analyses belonging to the foitite-Mg-foitite series. Oxygen isotope data on quartz-tourmaline pairs indicate formation temperatures between 550 and 350 °C for most of the quartz-tourmaline veins. Most of the tourmalines show strong sector zonation, fractionating certain major (e.g., Na, Mg), minor (e.g., Ti, Ca) and trace elements (e.g., Sr, Pb,…
Learning Similarity Scores by Using a Family of Distance Functions in Multiple Feature Spaces
2017
There exist a large number of distance functions that allow one to measure similarity between feature vectors and thus can be used for ranking purposes. When multiple representations of the same object are available, distances in each representation space may be combined to produce a single similarity score. In this paper, we present a method to build such a similarity ranking out of a family of distance functions. Unlike other approaches that aim to select the best distance function for a particular context, we use several distances and combine them in a convenient way. To this end, we adopt a classical similarity learning approach and face the problem as a standard supervised machine lea…
The Wilms' tumor suppressor gene (wt1) product regulates Dax-1 gene expression during gonadal differentiation.
1999
Gonadal differentiation is dependent upon a molecular cascade responsible for ovarian or testicular development from the bipotential gonadal ridge. Genetic analysis has implicated a number of gene products essential for this process, which include Sry, WT1, SF-1, and DAX-1. We have sought to better define the role of WT1 in this process by identifying downstream targets of WT1 during normal gonadal development. We have noticed that in the developing murine gonadal ridge, wt1 expression precedes expression of Dax-1, a nuclear receptor gene. We document here that the spatial distribution profiles of both proteins in the developing gonad overlap. We also demonstrate that WT1 can activate the D…
Physiological activation of the IgH 3' enhancer in B lineage cells is not blocked by Pax-5.
1996
The mouse 3' enhancer contains a high-affinity binding site for the paired box protein Pax-5. Here, we demonstrate by genomic footprinting that the rat 3' enhancer contains a low-affinity binding site for Pax-5, which is occupied in activated splenic B cells. Thus, binding of Pax-5 to the IgH 3' enhancer appears to be evolutionarily conserved in rodents. Analysis of Pax-5 expression in primary B cells demonstrates that Pax-5 remains expressed after 4 days of lipopolysaccharide (LPS) induction, but is down-regulated in 5-day stimulated cells. Similarly, the expression of Pax-5 is down-regulated in vivo in activated large splenocytes, in contrast to small resting cells. Multimerization of the…
A Simple Monte Carlo Model of a Hot Carrier Cell
2017
In the present work, a simplified model of a hot carrier cell is examined at different energy levels of carrier collection. Incident photons, Monte Carlo generated by employing the ASTM G173–03 data set, are accounted for individually as they interact with the cell. The hot carrier cells are examined in a transient state caused by a flash of photons with AM1.5 spectrum. Excess photon energy is recycled giving a form of thermalization of hot carriers. The sensitivity of contact variables and the device band gap on cell efficiency, has been studied.
A note on finite PST-groups
2007
[EN] A finite group G is said to be a PST-group if, for subgroups H and K of G with H Sylow-permutable in K and K Sylow-permutable in G, it is always the case that H is Sylow-permutable in G. A group G is a T*-group if, for subgroups H and K of G with H normal in K and K normal in G, it is always the case that H is Sylow-permutable in G. In this paper, we show that finite PST-groups and finite T*-groups are one and the same. A new characterisation of soluble PST-groups is also presented.
Algebraic (2, 2)-transformation groups
2009
This paper contains the more significant part of the article with the same title that will appear in the Volume 12 of Journal of Group Theory (2009). In this paper we determine all algebraic transformation groups $G$, defined over an algebraically closed field $\sf k$, which operate transitively, but not primitively, on a variety $\Omega$, provided the following conditions are fulfilled. We ask that the (non-effective) action of $G$ on the variety of blocks is sharply 2-transitive, as well as the action on a block $\Delta$ of the normalizer $G_\Delta$. Also we require sharp transitivity on pairs $(X,Y)$ of independent points of $\Omega$, i.e. points contained in different blocks.
Retrotransposon silencing and telomere integrity in somatic cells of Drosophila depends on the cytosine-5 methyltransferase DNMT2
2009
Here we show that the cytosine-5 methyltransferase DNMT2 controls retrotransposon silencing in Drosophila somatic cells. In Drosophila, significant DNMT2-dependent DNA methylation occurs during early embryogenesis. Suppression of white gene silencing by Mt2 (Dnmt2) null mutations in variegated P[w(+)] element insertions identified functional targets of DNMT2. The enzyme controls DNA methylation at retrotransposons in early embryos and initiates histone H4K20 trimethylation catalyzed by the SUV4-20 methyltransferase. In somatic cells, loss of DNMT2 eliminates H4K20 trimethylation at retrotransposons and impairs maintenance of retrotransposon silencing. In Dnmt2 and Suv4-20 null genotypes, re…
Invasion of thehobo transposable element studied byin situ hybridization on polytene chromosomes ofDrosophila melanogaster
1994
The invasion kinetics of hobo transposable element in the Drosophila melanogaster genome was studied by in situ hybridization on the polytene chromosomes. Six independent lines of Drosophila melanogaster flies that had been previously transformed by microinjection of the pHFL1 plasmid containing a complete hobo element were followed over 50 generations. We observed that hobo elements were scattered on each of the chromosome arms, with more insertion sites on the 3R arm. The total number of insertion sites remains quite small, between four and six, at generation 52. On the 2R arm, a short inversion appeared once at generation 52. Most of the integration sites reported here were already descr…