Imaging the asymmetric dust shell around CI Cam with long baseline optical interferometry

We present the first high angular resolution observation of the B[e] star/X-ray transient object CI Cam, performed with the two-telescope Infrared Optical Telescope Array (IOTA), its upgraded three-telescope version (IOTA3T) and the Palomar Testbed Interferometer (PTI). Visibilities and closure phases were obtained using the IONIC-3 integrated optics beam combiner. CI Cam was observed in the near-infrared H and K spectral bands, wavelengths well suited to measure the size and study the geometry of the hot dust surrounding CI Cam. The analysis of the visibility data over an 8 year period from soon after the 1998 outburst to 2006 shows that the dust visibility has not changed over the years. The visibility data shows that CI Cam is elongated which confirms the disc-shape of the circumstellar environment and totally rules out the hypothesis of a spherical dust shell. Closure phase measurements show direct evidence of asymmetries in the circumstellar environment of CI Cam and we conclude that the dust surrounding CI Cam lies in an inhomogeneous disc seen at an angle. The near-infrared dust emission appears as an elliptical skewed Gaussian ring with a major axis a = 7.58 +/- 0.24 mas, an axis ratio r = 0.39 +/- 0.03 and a position angle theta = 35 +/- 2 deg.Comment: 9 pages, 5 figures, accepted MNRA

Genomic resources in chickpea

Chickpea has considerably increased the genomic resources in recent years providing highly saturated genetic maps including anonymous or gene-specific markers targeting some agronomic traits of interest. In addition, the publication of the two draft genome sequences of Kabuli and Desi chickpea types opens a new era in genomic tools. Furthering in our understanding of the association between phenotypic traits (Quantitative Trait loci-QTL-or genes) with the transcriptome and gene annotation provided by genome sequencing data will be the future challenge to be able to exploit with success marker-assisted Selection(MAS)

Strong Near-Infrared Emission Interior to the Dust-Sublimation Radius of Young Stellar Objects MWC275 and AB Aur

Using the longest optical-interferometeric baselines currently available, we have detected strong near-infrared (NIR) emission from inside the dust-destruction radius of Herbig Ae stars MWC275 and AB Aur. Our sub-milli-arcsecond resolution observations unambiguously place the emission between the dust-destruction radius and the magnetospheric co-rotation radius. We argue that this new component corresponds to hot gas inside the dust-sublimation radius, confirming recent claims based on spectrally-resolved interferometry and dust evaporation front modeling.Comment: 12 pages, 4 figures, Accepted for publication in ApJ

The effect of prolonged simulated non- gravitational environment on mineral balance in the adult male, volume 1 Final report

Effect of prolonged bed rest with simulated weightlessness on mineral balance in male adult - Vol.

Spectral information criterion for automatic elbow detection

We introduce a generalized information criterion that contains other well-known information criteria, such as Bayesian information Criterion (BIC) and Akaike information criterion (AIC), as special cases. Furthermore, the proposed spectral information criterion (SIC) is also more general than the other information criteria, e.g., since the knowledge of a likelihood function is not strictly required. SIC extracts geometric features of the error curve and, as a consequence, it can be considered an automatic elbow detector. SIC provides a subset of all possible models, with a cardinality that often is much smaller than the total number of possible models. The elements of this subset are elbows of the error curve. A practical rule for selecting a unique model within the sets of elbows is suggested as well. Theoretical invariance properties of SIC are analyzed. Moreover, we test SIC in ideal scenarios where provides always the optimal expected results. We also test SIC in several numerical experiments: some involving synthetic data, and two experiments involving real datasets. They are all real-world applications such as clustering, variable selection, or polynomial order selection, to name a few. The results show the benefits of the proposed scheme. Matlab code related to the experiments is also provided. Possible future research lines are finally discussed

Universal and Automatic Elbow Detection for Learning the Effective Number of Components in Model Selection Problems

We design a Universal Automatic Elbow Detector (UAED) for deciding the effective number of components in model selection problems. The relationship with the information criteria widely employed in the literature is also discussed. The proposed UAED does not require the knowledge of a likelihood function and can be easily applied in diverse applications, such as regression and classification, feature and/or order selection, clustering, and dimension reduction. Several experiments involving synthetic and real data show the advantages of the proposed scheme with benchmark techniques in the literature

Proposal and validation of a modified Simulated annealing algorithm for solving optimization problems

Durante las últimas décadas, los métodos de optimización heurísticos basados en imitar procesos naturales, biológicos, sociales o culturales a nivel computacional han despertado el interés de la comunidad científica debido a su capacidad para explorar eficientemente espacios de soluciones multimodales y multidimensionales. A pesar de todos los trabajos publicados en la literatura internacional, la mayoría de los algoritmos heurísticos todavía presentan baja precisión y exactitud. En este contexto, se propone y se valida un algoritmo Simulated annealing modificado (ASAM) para la solución de problemas de optimización. La evaluación del desempeño se realizó en funciones de pruebas (benchmark functions) con y sin restricciones reportadas en la literatura internacional y en problemas prácticos de diseño en ingeniería civil. En todos los casos analizados ASAM obtuvo iguales o mejores resultados que los reportados por otros autores, ilustrando la aplicabilidad del algoritmo propuesto.Over the last decades, heuristic optimization methods based on imitating natural, biological, social or cultural processes on a computational level have aroused the interest of the scientific community due to their ability to effectively explore multimodal and multidimensional solution spaces. Despite all the papers published in the international literature, most heuristic algorithms still have low precision and accuracy. In this context, a modified Simulated annealing algorithm (MSAA) is proposed and validated for solving optimization problems. Performance evaluation was performed on test functions (benchmark functions) with and without restrictions reported in the international literature and practical design problems in civil engineering. In all cases analyzed MSAA obtained equal or better results than those reported by other authors, illustrating the applicability of the proposed algorithm.Peer Reviewe

Context and collaborative problem solving (Cps): The development of observable signifiers to inform the design of cps learning analytics

Collaborative Problem Solving (CPS) is a key skill for the modern workplace. We do not, however, have widely accepted ways of assessing and monitoring CPS to inform educators and learners and enable the provision of effective support. This paper reports the findings of an empirical study involving 15 school students aged 14-15 years taking part in a 2-day Hack Event. The analysis identifies the observable signifiers of CPS and offers a step towards the design of automated data capture protocols and CPS learning analytics

Bacterial evolution: Resistance is a numbers game

Plasmids are well known for spreading antibiotic-resistance genes between bacterial strains. Recent experiments show that they can also act as catalysts for evolutionary innovation, promoting rapid evolution of novel antibiotic resistance

Solar radiation induced damage to optical properties of ZnO-type pigments Technical summary report, Jun. 27, 1966 - Mar. 27, 1967

Degradation model of solar radiation damage to optical properties of zinc oxide pigments used for spacecraft thermal control coating