Linear Temperature Variation of the Penetration Depth in YBCO Thin Films

We have measured the penetration depth $\lambda(T)$ on $\rm YBa_{2}Cu_{3}O_{7}$ thin films from transmission at 120, 330 and 510~GHz, between 5 and 50~K. Our data yield simultaneously the absolute value and the temperature dependence of $\lambda(T)$. In high quality films $\lambda(T)$ exhibits the same linear temperature dependence as single crystals, showing its intrinsic nature, and $\lambda(0)=1750\,{\rm \AA}$. In a lower quality one, the more usual $T^2$ dependence is found, and $\lambda(0)=3600\,{\rm \AA}$. This suggests that the $T^2$ variation is of extrinsic origin. Our results put the $d$-wave like interpretation in a much better position.Comment: 12 pages, revtex, 4 uuencoded figure

RUNX3 Regulates Intercellular Adhesion Molecule 3 (ICAM-3) Expression during Macrophage Differentiation and Monocyte Extravasation

The adhesion molecule ICAM-3 belongs to the immunoglobulin gene superfamily and functions as a ligand for the β2 integrins LFA-1, Mac-1 and αdβ2. The expression of ICAM-3 is restricted to cells of the hematopoietic lineage. We present evidences that the ICAM-3 gene promoter exhibits a leukocyte-specific activity, as its activity is significantly higher in ICAM-3+ hematopoietic cell lines. The activity of the ICAM-3 gene promoter is dependent on the occupancy of RUNX cognate sequences both in vitro and in vivo, and whose integrity is required for RUNX responsiveness and for the cooperative actions of RUNX with transcription factors of the Ets and C/EBP families. Protein analysis revealed that ICAM-3 levels diminish upon monocyte-derived macrophage differentiation, monocyte transendothelial migration and dendritic cell maturation, changes that correlate with an increase in RUNX3. Importantly, disruption of RUNX-binding sites led to enhanced promoter activity, and small interfering RNA-mediated reduction of RUNX3 expression resulted in increased ICAM-3 mRNA levels. Altogether these results indicate that the ICAM-3 gene promoter is negatively regulated by RUNX transcription factors, which contribute to the leukocyte-restricted and the regulated expression of ICAM-3 during monocyte-to-macrophage differentiation and monocyte extravasation

Refining Face Tracking with Integral Projections

Integral projections can be used, by themselves, to accurately track human faces in video sequences. Using projections, the tracking problem is effectively separated into the vertical, horizontal and rotational dimensions. Each of these parts is solved, basically, through the alignment of a projection signal -- a one-dimensional pattern -- with a projection model. The effect of this separation is an important improvement in feature location accuracy and computational efficiency. A comparison has been done with respect to the CamShift algorithm. Our experiments have also shown a high robustness of the method to 3D pose, facial expression, lighting conditions, partial occlusion, and facial features

3-dimensional character of semimetallic InAs-GaSb super-lattices

Contains fulltext : 115612.pdf (publisher's version ) (Open Access

Observation of double cyclotron-resonance and interband-transitions in InAs-GaSb multi-heterojunctions

Contains fulltext : 115611.pdf (publisher's version ) (Open Access

The quantum Hall effect in modulation doped In0.53Ga 0.47As-InP heterojunctions

We report the first observation of the quantum Hall effect in modulation doped In0.53Ga0.47As-InP heterojunctions at 4.2 and 1.5 K. The results are then compared to data obtained in a GaAs-Al xGa1-xAs heterojunction having similar electronic characteristics.Nous décrivons la première observation à 4,2 et 1,5 K de l'effet Hall quantique dans les hétérojonctions In0,53Ga0,47As-InP à dopage modulé. Ces résultats sont ensuite comparés à ceux obtenus sur une hétérojonction GaAs-AlxGa1-xAs ayant des caractéristiques électroniques semblables

ELECTRON TRANSFER IN Hg1-xCdxTe-CdTe HETEROSTRUCTURES

Des expériences de magnéto-absorption à 1,6K dans des hétérojonctions HgCdTe-CdTe montrent qu'un gaz d'électrons bidimensionnel est formé à l'interface du côté HgCdTe. La masse effective des électrons des deux sous-bandes peuplées est mesurée et l'origine du transfert est discutée.Far infrared magneto-absorption experiments performed at 1.6K in HgCdTe-CdTe heterojunctions show that a two-dimensional electron gas is formed in the HgCdTe layer at the HgCdTe-CdTe interface. The electron effective masses of the two populated subbands is obtained and compared to previous theoretical calculations. The electron transfer across the interface involves deep traps in the CdTe layers