On the maximum bias functions of MM-estimates and constrained M-estimates of regression

We derive the maximum bias functions of the MM-estimates and the constrained M-estimates or CM-estimates of regression and compare them to the maximum bias functions of the S-estimates and the $\tau$-estimates of regression. In these comparisons, the CM-estimates tend to exhibit the most favorable bias-robustness properties. Also, under the Gaussian model, it is shown how one can construct a CM-estimate which has a smaller maximum bias function than a given S-estimate, that is, the resulting CM-estimate dominates the S-estimate in terms of maxbias and, at the same time, is considerably more efficient.Comment: Published at http://dx.doi.org/10.1214/009053606000000975 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Low-temperature anomalies of a vapor deposited glass

We investigate the low temperature properties of two-dimensional Lennard-Jones glass films, prepared in silico both by liquid cooling and by physical vapor deposition. We identify deep in the solid phase a crossover temperature $T^*$, at which slow dynamics and enhanced heterogeneity emerge. Around $T^*$, localized defects become visible, leading to vibrational anomalies as compared to standard solids. We find that on average, $T^*$ decreases in samples with lower inherent structure energy, suggesting that such anomalies will be suppressed in ultra-stable glass films, prepared both by very slow liquid cooling and vapor deposition.Comment: 10 pages including appendices, 8 figures. Version accepted for Physical Review Material

Numerically flat Higgs vector bundles

After providing a suitable definition of numerical effectiveness for Higgs bundles, and a related notion of numerical flatness, in this paper we prove, together with some side results, that all Chern classes of a Higgs-numerically flat Higgs bundle vanish, and that a Higgs bundle is Higgs-numerically flat if and only if it is has a filtration whose quotients are flat stable Higgs bundles. We also study the relation between these numerical properties of Higgs bundles and (semi)stability.Comment: 11 page

A video object generation tool allowing friendly user interaction

In this paper we describe an interactive video object segmentation tool developed in the framework of the ACTS-AC098 MOMUSYS project. The Video Object Generator with User Environment (VOGUE) combines three different sets of automatic and semi-automatic-tool (spatial segmentation, object tracking and temporal segmentation) with general purpose tools for user interaction. The result is an integrated environment allowing the user-assisted segmentation of any sort of video sequences in a friendly and efficient manner.Peer ReviewedPostprint (published version

Interplay between glucose and palmitate uptake in breast carcinoma in vitro

One of the most studied tumor cells lines in vitro is the breast carcinoma MDA-MB-231 cell line. Several studies have proved its glycolytic profile, namely known as the Warburg effect. Glutamine oxidation is also important for its metabolism. Nevertheless, the use of fatty acids for obtaining energy in these cells is still rising. Palmitic acid is the most common saturated fatty acid, containing sixteen carbons in its structure. However, the use of palmitate for metabolic studies in MDA-MB-231 is not very extended due to its pro-apoptotic effect in this cell line after certain time exposure. Nonetheless, in this work we used palmitate as a metabolic fuel for just 30 minutes in order to see the almost immediate response of the cells to its presence, after a 30 minutes fast period. Our results show that MDA-MB-231 cells are not able of oxidizing palmitate nor producing lactate from it. Simultaneous presence of palmitate with glucose or with glutamine does not affect glucose nor glutamine uptake in these cells. However, we observed that even low concentrations of glucose increase palmitate uptake in MDA-MB-231 after a 30 minutes incubation. Treatment with 5 mM 2-deoxyglucose also for 30 minutes counters this rise, since 2-deoxyglucose diminishes palmitate uptake. Increasing glucose concentration to the same dosis of 2-deoxyglucose leads to a prevalence of the glucose effect on palmitate uptake. The exact role of glucose and glucose derivatives should be further studied in order to know more about palmitate metabolism in this cell line.Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). This communication has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"

Identification and characterization of new anti-angiogenic compounds from natural sources

The inhibition of angiogenesis has attracted broad attention in the field of pharmacological research, not only for cancer, but for other angiogenesis dependent diseases including ophthalmic, cutaneous and inflammatory diseases, as well as a number of rare diseases. Our research group has characterized multiple new natural bioactive compounds with multitargeted antiangiogenic effects by employing a well-established set of in vitro, in vivo and ex vivo preclinical models of angiogenesis. Most of them have been isolated from plants and terrestrial microorganisms, mainly due to their higher availability and because their therapeutic effects had been previously known in folk traditional medicines. In vitro primary screening includes cell differentiation and toxicity and proliferation assays. Secondary screening involves several experiments to evaluate effects on adhesion, migration, invasion, apoptosis or cell cycle analysis, among others. Additionally, we perform a further molecular characterization analyzing possible signaling pathways that are affected to elucidate their mechanism of action. The characterization is completed with the ex vivo aortic ring assay, and in vivo assays, as CAM and zebrafish assays, to ensure the anti-angiogenic ability. As a fruit of the mentioned screening, a number of compounds with remarkable anti-angiogenic activity have been identified and characterized.Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain)]. This communicaction has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"

Fasentin, a glucose uptake inhibitor, is also able to inhibit angiogenesis

Es comunicación a congreso en formato pósterThe role of glucose on endothelial cell (EC) metabolism and angiogenesis has been an emerging issue in the last few years. Some inhibitors of glucose metabolism, such as 2-deoxyglucose, have been shown to have anti-angiogenic effects. Fasentin is a poor-studied inhibitor of glucose uptake which modulates GLUT-1 and GLUT-4 transporters in cancer cells. We wanted to test its possible effect on EC glucose uptake, showing a light decrease in HMEC at 100 µM. Lower doses did not affect this characteristic of glucose metabolism. In line with this fact, fasentin at 100 µM totally inhibited tube formation on Matrigel in these cells. This anti-angiogenic effect is not likely to be helped by a pro-apoptotic effect of fasentin but, as proved with additional assays, it could be due to a decrease on the signaling for extracellular matrix degradation. More research would be necessary in order to elucidate its fine regulation on angiogenesis and metabolism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. [Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). This communicaction has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"]