Ensenada Center for Scientific Research and Higher Education

About: Ensenada Center for Scientific Research and Higher Education is a facility organization based out in Ensenada, Mexico. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 1934 authors who have published 3733 publications receiving 63115 citations.

Ecological Validity and Pervasiveness in the Evaluation of Ubiquitous Computing Technologies for Health Care

Abstract: The difficulties associated with the evaluation of ubiquitous computing (Ubicomp) technologies increase in application domains such as hospitals, where human life can be at risk, privacy of personal records is paramount, and labor is costly and highly distributed across space and time. For the last 6 years numerous Ubicomp technologies in support of hospital work have been created and pilot-tested. In this article, the lessons learned from these evaluations are discussed, using two criteria to classify them. The first criterion is ecological validity, namely, the extent to which the evaluation is conducted under realistic conditions. Alternatives range from controlled experiments to in situ evaluations. The article argues in particular for the advantages of intermediate approaches, which is referred to as in silico and in replica. The second criterion relates to the degree of integration of the technology with the environment, which is referred to as its pervasiveness. The evaluation grid that comes out o...

Effect of eight benthic diatoms as feed on the growth of red abalone (Haliotis rufescens) postlarvae.

Abstract: The growth rate of abalone post larvae of Haliotis rufescens fed ad libitum with a benthic monoalgal diatom culture maintained as monocultures on a semi-commercial scale, was evaluated and correlated with the biochemical composition of the diatoms. The cell size (7.0 × 4.0 µm to 21.0 × 7.5 µm), protein percentage (7.42% to 13.66%), and ash content (49.03% to 59.61%) were different among diatom strains; lipid percentage, nitrogen free extract, and energy content (Kcal g−1) were similar among diatom strains. The values of essential and non-essential amino and fatty acids composition differed among diatom strains. Differences in the abalone shell length and orthogonal analyses revealed postlarval growth was dependent on the quality of the food source. Postlarvae abalone displaying the longest shell lengths were fed Nitzschia thermalis var. minor and Amphiprora paludosa var. hyalina (1,712.0 ± 61 µm and 1,709 ± 67 µm, respectively), followed by Navicula incerta (1,413.3 ± 43 µm). The fatty acid content of benthic diatoms and abalone growth rate were not correlated.

Generalization of the optical theorem: experimental proof for radially polarized beams.

Abstract: The optical theorem, which is a consequence of the energy conservation in scattering processes, directly relates the forward scattering amplitude to the extinction cross-section of the object. Originally derived for planar scalar waves, it neglects the complex structure of the focused beams and the vectorial nature of the electromagnetic field. On the other hand, radially or azimuthally polarized fields and various vortex beams, essential in modern photonic technologies, possess a prominent vectorial field structure. Here, we experimentally demonstrate a complete violation of the commonly used form of the optical theorem for radially polarized beams at both visible and microwave frequencies. We show that a plasmonic particle illuminated by such a beam exhibits strong extinction, while the scattering in the forward direction is zero. The generalized formulation of the optical theorem provides agreement with the observed results. The reported effect is vital for the understanding and design of the interaction of complex vector beams carrying longitudinal field components with subwavelength objects important in imaging, communications, nanoparticle manipulation, and detection, as well as metrology.

Are flood basalt eruptions monogenetic or polygenetic

Abstract: A fundamental classification of volcanoes divides them into “monogenetic” and “polygenetic.” We discuss whether flood basalt fields, the largest volcanic provinces, are monogenetic or polygenetic. A polygenetic volcano, whether a shield volcano or a stratovolcano, erupts from the same dominant conduit for millions of years (excepting volumetrically small flank eruptions). A flood basalt province, built from different eruptive fissures dispersed over wide areas, can be considered a polygenetic volcano without any dominant vent. However, in the same characteristic, a flood basalt province resembles a monogenetic volcanic field, with only the difference that individual eruptions in the latter are much smaller. This leads to the question how a flood basalt province can be two very different phenomena at the same time. Individual flood basalt eruptions have previously been considered monogenetic, contrasted by only their high magma output (and lava fluidity) with typical “small-volume monogenetic” volcanoes. Field data from Hawaiian shield volcanoes, Iceland, and the Deccan Traps show that whereas many feeder dykes were single magma injections, and the eruptions can be considered “large monogenetic” eruptions, multiple dykes are equally abundant. They indicate that the same dyke fissure repeatedly transported separate magma batches, feeding an eruption which was thus polygenetic by even the restricted definition (the same magma conduit). This recognition helps in understanding the volcanological, stratigraphic, and geochemical complexity of flood basalts. The need for clear concepts and terminology is, however, strong. We give reasons for replacing “monogenetic volcanic fields” with “diffuse volcanic fields” and for dropping the term “polygenetic” and describing such volcanoes simply and specifically as “shield volcanoes,” “stratovolcanoes,” and “flood basalt fields.”