On the ECB\u27s ‘most significant non-standard measure\u27

Article interpreting the speech by Manuel Gonz¡lez-P¡ramo and SLTRO\u27s impact on yield

Nencki Genomics Database—Ensembl funcgen enhanced with intersections, user data and genome-wide TFBS motifs

We present the Nencki Genomics Database, which extends the functionality of Ensembl Regulatory Build (funcgen) for the three species: human, mouse and rat. The key enhancements over Ensembl funcgen include the following: (i) a user can add private data, analyze them alongside the public data and manage access rights; (ii) inside the database, we provide efficient procedures for computing intersections between regulatory features and for mapping them to the genes. To Ensembl funcgen-derived data, which include data from ENCODE, we add information on conserved non-coding (putative regulatory) sequences, and on genome-wide occurrence of transcription factor binding site motifs from the current versions of two major motif libraries, namely, Jaspar and Transfac. The intersections and mapping to the genes are pre-computed for the public data, and the result of any procedure run on the data added by the users is stored back into the database, thus incrementally increasing the body of pre-computed data. As the Ensembl funcgen schema for the rat is currently not populated, our database is the first database of regulatory features for this frequently used laboratory animal. The database is accessible without registration using the mysql client: mysql –h database.nencki-genomics.org –u public. Registration is required only to add or access private data. A WSDL webservice provides access to the database from any SOAP client, including the Taverna Workbench with a graphical user interface

From windows display to the decision

Inom  handelsbranschen  är  konkurrensen  en  av  de  viktigaste  aspekterna  som  butiker  måste förhålla sig till. För att särskilja sig från konkurrenter och uppmärksammas av konsumenter är det viktigt att marknadsföra butiken rätt. En av de aktiviteter som marknadsförare har till sin användning är utformning av skyltfönster. För att budskapet ska uppfattas av konsumenterna, gäller  det  att  exponera  varorna  på  ett  sätt  som  stimulerar  olika  sinnen.  Varorna  ska  även placeras så att de blir synliga för kunden, oavsett från vilket håll den närmar sig butiken.  Skyltfönster  ingår  i  konceptet  visual  merchandising,  som  handlar  om  bildlig  information. Denna typ av information tas lättare upp av en konsument, än i en skriftlig form, vilket leder till en effektivare marknadsföring. Eftersom skyltfönstret är butikens ”ansikte” utåt kommer uppsatsen behandla vilken bildlig information butiken disponerar som är av störst intresse för konsumenter.   Uppsatsens syfte är att undersöka vilka faktorer som kunder påverkas av när de väljer butik att besöka, med fokus på skyltfönstret som informationskälla. Utifrån syftet har vi genomfört en undersökning, innehållande ett frågeformulär, där vi, med stöd i teorin, sammankopplade alla  de  viktiga  faktorerna.  Det  som  vi  ansåg  var  relevant  för  problemformuleringen  var butikens    profil    och    sortiment,    nyheter    och    inspiration,    pris    samt    kampanjer. Respondentgruppen bestod av 50 kvinnor i olika åldrar, och på det sättet har vi fått fram ett generaliserat resultat.  Slutsatser som kan dras, efter att resultatet analyserats, är att skyltfönstret är av betydelse för kunders beslut om att gå in i butik. Det som också framgår av resultatet är att inspiration och nyheter, butikens profil och sortiment är den information som konsumenter använder sig till största delen av, medan kampanjer och pris är av mindre betydelse

Critical Evaluation of Various Spontaneous Polarization Models and Induced Electric Fields in III-Nitride Multi-Quantum Wells

International audienceIn this paper, ab initio calculations are used to determine polarization difference in zinc blende (ZB), hexagonal (H) and wurtzite (WZ) AlN-GaN and GaN-InN superlattices. It is shown that a polarization difference exists between WZ nitride compounds, while for H and ZB lattices the results are consistent with zero polarization difference. It is therefore proven that the difference in Berry phase spontaneous polarization for bulk nitrides (AlN, GaN and InN) obtained by Bernardini et al. and Dreyer et al. was not caused by the different reference phase. These models provided absolute values of the polarization that differed by more than one order of magnitude for the same material, but they provided similar polarization differences between binary compounds, which agree also with our ab initio calculations. In multi-quantum wells (MQWs), the electric fields are generated by the well-barrier polarization difference; hence, the calculated electric fields are similar for the three models, both for GaN/AlN and InN/GaN structures. Including piezoelectric effect, which can account for 50% of the total polarization difference, these theoretical data are in satisfactory agreement with photoluminescence measurements in GaN/AlN MQWs. Therefore, the three models considered above are equivalent in the treatment of III-nitride MQWs and can be equally used for the description of the electric properties of active layers in nitride-based optoelectronic devices

Polarization doping— Ab initio verification of the concept: Charge conservation and nonlocality

International audienceIn this work, we study the emergence of polarization doping in Al x Ga 1−x N layers with graded composition from a theoretical viewpoint. It is shown that bulk electric charge density emerges in the graded concentration region. The magnitude of the effect, i.e., the relation between the polarization bulk charge density and the concentration gradient is obtained. The appearance of mobile charge in the wurtzite structure grown along the polar direction was investigated using the combination of ab initio and drift-diffusion models. It was shown that the ab initio results can be recovered precisely by proper parameterization of drift-diffusion representation of the complex nitride system. It was shown that the mobile charge appears due to the increase of the distance between opposite polarization-induced charges. It was demonstrated that, for sufficiently large space distance between polarization charges, the opposite mobile charges are induced. We demonstrate that the charge conservation law applies for fixed and mobile charge separately, leading to nonlocal compensation phenomena involving (i) the bulk fixed and polarization sheet charge at the heterointerfaces and (ii) the mobile band and the defect charge. Therefore, two charge conservation laws are obeyed that induces nonlocality in the system. The magnitude of the effect allows obtaining technically viable mobile charge density for optoelectronic devices without impurity doping (donors or acceptors). Therefore, it provides an additional tool for the device designer, with the potential to attain high conductivities: high carrier concentrations can be obtained even in materials with high dopant ionization energies, and the mobility is not limited by scattering at ionized impurities

Polarization doping— Ab initio verification of the concept: Charge conservation and nonlocality

International audienceIn this work, we study the emergence of polarization doping in Al x Ga 1−x N layers with graded composition from a theoretical viewpoint. It is shown that bulk electric charge density emerges in the graded concentration region. The magnitude of the effect, i.e., the relation between the polarization bulk charge density and the concentration gradient is obtained. The appearance of mobile charge in the wurtzite structure grown along the polar direction was investigated using the combination of ab initio and drift-diffusion models. It was shown that the ab initio results can be recovered precisely by proper parameterization of drift-diffusion representation of the complex nitride system. It was shown that the mobile charge appears due to the increase of the distance between opposite polarization-induced charges. It was demonstrated that, for sufficiently large space distance between polarization charges, the opposite mobile charges are induced. We demonstrate that the charge conservation law applies for fixed and mobile charge separately, leading to nonlocal compensation phenomena involving (i) the bulk fixed and polarization sheet charge at the heterointerfaces and (ii) the mobile band and the defect charge. Therefore, two charge conservation laws are obeyed that induces nonlocality in the system. The magnitude of the effect allows obtaining technically viable mobile charge density for optoelectronic devices without impurity doping (donors or acceptors). Therefore, it provides an additional tool for the device designer, with the potential to attain high conductivities: high carrier concentrations can be obtained even in materials with high dopant ionization energies, and the mobility is not limited by scattering at ionized impurities

Polarization Doping in a GaN-InN System—Ab Initio Simulation

Polarization doping in a GaN-InN system with a graded composition layer was studied using ab initio simulations. The electric charge volume density in the graded concentration part was determined by spatial potential dependence. The emerging graded polarization charge was determined to show that it could be obtained from a polarization difference and the concentration slope. It was shown that the GaN-InN polarization difference is changed by piezoelectric effects. The polarization difference is in agreement with the earlier obtained data despite the relatively narrow bandgap for the simulated system. The hole generation may be applied in the design of blue and green laser and light-emitting diodes

Polarization Doping in a GaN-InN System—Ab Initio Simulation

Polarization doping in a GaN-InN system with a graded composition layer was studied using ab initio simulations. The electric charge volume density in the graded concentration part was determined by spatial potential dependence. The emerging graded polarization charge was determined to show that it could be obtained from a polarization difference and the concentration slope. It was shown that the GaN-InN polarization difference is changed by piezoelectric effects. The polarization difference is in agreement with the earlier obtained data despite the relatively narrow bandgap for the simulated system. The hole generation may be applied in the design of blue and green laser and light-emitting diodes