Application of the level set method for the visual representation of continuous cellular automata oriented to anisotropic wet etching

[EN] Atomistic models are a very valuable simulation tool in the field of material science. Among them are the continuous cellular automata (CCA), which can simulate accurately the process of chemical etching used in micro-electro-mechanical-systems (MEMS) micromachining. Due to the CCA intrinsic atomistic nature, simulation results are obtained in the form of a cloud of points, so data visualization has been usually problematic. When using these models as a part of a computer aided design tool, good data visualization is very important. In this paper, a minimum energy model implemented with the level set (LS) method for improving the visual representation of simulated MEMS is presented. Additionally, the sparse field method has been applied to reduce the high computational cost of the original LS. Finally, some reconstructed surfaces with completely different topologies are presented, proving the effectiveness of our implementation and the fact that it is capable of producing any real surface, flat and smooth ones.We thank Miguel Angel Gosalvez for his collaboration in the early stages of this research. This work has been supported by the Spanish FPI-MICINN BES-2011-045940 grant. Also, we acknowledge support by the JAE-Doc grant form the Junta para la Ampliacion de Estudios program co-funded by FSE.Montoliu Álvaro, C.; Ferrando Jódar, N.; Cerdá Boluda, J.; Colom Palero, RJ. (2014). Application of the level set method for the visual representation of continuous cellular automata oriented to anisotropic wet etching. International Journal of Computer Mathematics. 91(1):124-134. https://doi.org/10.1080/00207160.2013.801464S12413491

Color image registration under illumination changes

The estimation of parametric global motion has had a significant attention during the last two decades, but despite the great efforts invested, there are still open issues. One of the most important ones is related to the ability to recover large deformation between images in the presence of illumination changes while kipping accurate estimates. Illumination changes in color images are another important open issue. In this paper, a Generalized least squared-based motion estimator is used in combination with color image model to allow accurate estimates of global motion between two color images under the presence of large geometric transformation and illumination changes. Experiments using challenging images have been performed showing that the presented technique is feasible and provides accurate estimates of the motion and illumination parameter

Depression and Suicide Risk in Mild Cognitive Impairment: The Role of Alzheimer’s Disease Biomarkers

Background: Patients with depression and mild cognitive impairment (MCI) are at greater risk of developing dementia. Depression involves a higher risk of suicidal ideation (SI) and suicide attempts (SA). Biomarkers of Alzheimer’s Disease (AD) could help to clarify the role of depression and SI in AD. Method: Fifty-nine participants aged > 50 with criteria of MCI positive (MCI-AD) (n=22) and negative (MCI-Non AD) (n=24) AD and healthy controls (HC) (n=13) were evaluated. We used the Geriatric Depression Scale (GDS-30) and the GDS-SI factor to measure depression and indirect risk for suicide, respectively. Additionally, AD biomarkers such as amyloid-ß (Aß), hyperphosphorilated tau (P-tau), and total tau (T-tau) in cerebrospinal fluid (CSF) were analyzed. Results: No significant differences between the groups were found in depression. However, in the MCI-AD group, lower P-tau and T-tau levels were related to higher GDS-SI scores, suggesting that MCI-AD patients with lower AD pathology are at a higher risk of suicide. Conclusions: The result highlights the importance of considering SI in the initial phases of AD, and the potential role of AD biomarkers in early detection of symptoms. Antecedentes: Los pacientes con depresión y deterioro cognitivo leve (DCL) tienen un alto riesgo de desarrollar demencia. La depresión implica un alto riesgo de ideación suicida (IS) e intentos de suicidio (AS). Los biomarcadores de la enfermedad de Alzheimer (EA) pueden clarificar el papel de la depresión e IS en la EA. Método: Cincuenta y nueve participantes >50 años con criterios de DCL-EA positivo (DCL-EA; 22) y negativo (DCL-NoEA; 24) y 13 controles sanos. La depresión fue evaluada con la Escala Geriátrica de Depresión (GDS-30) y la IS con el factor GDS-IS. Además, se midieron los siguientes biomarcadores en el líquido cefalorraquídeo: ß-amiloide (ß-A), tau hiperfosforilada (H-tau) y total (T-tau). Resultados: No se encontraron diferencias significativas entre los tres grupos de participantes en depresión o en IS. Sin embargo, en el grupo DCL-EA, niveles más bajos de H-tau y T-tau, indicadores de menor patología EA, se relacionaron significativamente con mayor riesgo de suicidio indirecto. Conclusiones: Este resultado subraya la importancia de considerar la IS en fases iniciales de EA, y el potencial papel de los biomarcadores de EA para detectar sus síntomas

Spatiotemporal correlations of handset-based service usages

We study spatiotemporal correlations and temporal diversities of handset-based service usages by analyzing a dataset that includes detailed information about locations and service usages of 124 users over 16 months. By constructing the spatiotemporal trajectories of the users we detect several meaningful places or contexts for each one of them and show how the context affects the service usage patterns. We find that temporal patterns of service usages are bound to the typical weekly cycles of humans, yet they show maximal activities at different times. We first discuss their temporal correlations and then investigate the time-ordering behavior of communication services like calls being followed by the non-communication services like applications. We also find that the behavioral overlap network based on the clustering of temporal patterns is comparable to the communication network of users. Our approach provides a useful framework for handset-based data analysis and helps us to understand the complexities of information and communications technology enabled human behavior.Comment: 11 pages, 15 figure

Importing genetically altered animals : ensuring quality

The reproducibility of research using laboratory animals requires reliable management of their quality, in particular of their genetics, health and environment, all of which contribute to their phenotypes. The point at which these biological materials are transferred between researchers is particularly sensitive, as it may result in a loss of integrity of the animals and/or their documentation. Here, we describe the various aspects of laboratory animal quality that should be confirmed when sharing rodent research models. We also discuss how repositories of biological materials support the scientific community to ensure the continuity of the quality of laboratory animals. Both the concept of quality and the role of repositories themselves extend to all exchanges of biological materials and all networks that support the sharing of these reagents.Peer reviewe

Programmable integrated front-end for SiPM/PMT PET detectors with continuous scintillating crystal

[EN] AMIC architecture has been introduced in previous works in order to provide a generic and expandable solution for implementing large number of outputs SiPM array/PMT detectors. The underlying idea in AMIC architecture is to calculate the moments of the detected light distribution in an analog fashion. These moments provide information about energy, x/y position, etc. of the light distribution of the detected event. Moreover this means that a small set of signals contains most of the information of the event, thus reducing the number of channels to be acquired. This paper introduces a new front-end device AMIC2GR which implements the AMIC architecture improving the features of the former integrated devices. Higher bandwidth and filtering coefficient precision along with a lower noise allow to apply some detector enhancements. Inhomogeneity among detector elements throughout the array can be reduced. Depth of interaction measurements can be obtained from the light distribution analysis. Also a common trigger signal can be obtained for the whole detector array. Finally AMIC2GR preamplifier stage close to SiPM output signals optimizes signal to noise ratio, which allows to reduce SiPM gain by using lower operating voltages thus reducing dark noiseThis work was supported by Universitat Politecnica de Val ` encia ` through research program PAID06-10-2212.Herrero Bosch, V.; Monzó Ferrer, JM.; Ros García, A.; Aliaga Varea, RJ.; González Martínez, AJ.; Montoliu, C.; Colom Palero, RJ.... (2012). Programmable integrated front-end for SiPM/PMT PET detectors with continuous scintillating crystal. Journal of Instrumentation. 7. https://doi.org/10.1088/1748-0221/7/12/C12021S7Llosa, G., Barrio, J., Cabello, J., Lacasta, C., Oliver, J. F., Rafecas, M., … Piemonte, C. (2011). Development of a PET prototype with continuous LYSO crystals and monolithic SiPM matrices. 2011 IEEE Nuclear Science Symposium Conference Record. doi:10.1109/nssmic.2011.6153684Herrero-Bosch, V., Lerche, C. W., Spaggiari, M., Aliaga-Varea, R., Ferrando-Jodar, N., & Colom-Palero, R. (2011). AMIC: An Expandable Front-End for Gamma-Ray Detectors With Light Distribution Analysis Capabilities. IEEE Transactions on Nuclear Science, 58(4), 1641-1646. doi:10.1109/tns.2011.2152855Lerche, C. W., Benlloch, J. M., Sanchez, F., Pavon, N., Escat, B., Gimenez, E. N., … Martinez, J. (2005). Depth of /spl gamma/-ray interaction within continuous crystals from the width of its scintillation light-distribution. IEEE Transactions on Nuclear Science, 52(3), 560-572. doi:10.1109/tns.2005.851424Lerche, C. W., Herrero-Bosch, V., Spaggiari, M., Mateo-Jimenez, F., Monz-Ferrer, J. M., Colom-Palero, R. J., & Mora-Mas, F. (2010). Fast circuit topology for spatial signal distribution analysis. 2010 17th IEEE-NPSS Real Time Conference. doi:10.1109/rtc.2010.5750391Bult, K., & Geelen, G. J. G. M. (1992). An inherently linear and compact MOST-only current division technique. IEEE Journal of Solid-State Circuits, 27(12), 1730-1735. doi:10.1109/4.17309

Genome-wide association study of metabolic traits reveals novel gene-metabolite-disease links.

Metabolic traits are molecular phenotypes that can drive clinical phenotypes and may predict disease progression. Here, we report results from a metabolome- and genome-wide association study on (1)H-NMR urine metabolic profiles. The study was conducted within an untargeted approach, employing a novel method for compound identification. From our discovery cohort of 835 Caucasian individuals who participated in the CoLaus study, we identified 139 suggestively significant (P<5×10(-8)) and independent associations between single nucleotide polymorphisms (SNP) and metabolome features. Fifty-six of these associations replicated in the TasteSensomics cohort, comprising 601 individuals from São Paulo of vastly diverse ethnic background. They correspond to eleven gene-metabolite associations, six of which had been previously identified in the urine metabolome and three in the serum metabolome. Our key novel findings are the associations of two SNPs with NMR spectral signatures pointing to fucose (rs492602, P = 6.9×10(-44)) and lysine (rs8101881, P = 1.2×10(-33)), respectively. Fine-mapping of the first locus pinpointed the FUT2 gene, which encodes a fucosyltransferase enzyme and has previously been associated with Crohn's disease. This implicates fucose as a potential prognostic disease marker, for which there is already published evidence from a mouse model. The second SNP lies within the SLC7A9 gene, rare mutations of which have been linked to severe kidney damage. The replication of previous associations and our new discoveries demonstrate the potential of untargeted metabolomics GWAS to robustly identify molecular disease markers