Image-based localization and pose recovery using scale invariant features

In this paper, we propose a vision based mobile robot localization strategy. Local scale-invariant features are used as natural landmarks in unstructured and unmodified environment. The local characteristics of the features we use prove to be robust to occlusion and outliers. In addition, the invariance of the features to viewpoint change makes them suitable landmarks for mobile robot localization. Scale-invariant features detected in the first exploration are indexed into a location database. Indexing and voting allow efficient recognition of global localization. The localization result is verified by epipolar geometry between the representative view in database and the view to be localized, thus the probability of false localization will be decreased. The localization system can recover the pose of the camera mounted on the robot by essential matrix decomposition. Then the position of the robot can be computed easily. Both calibrated and un-calibrated cases are discussed and relative position estimation based on calibrated camera turns out to be the better choice. Experimental results show that our approach is effective and reliable in the case of illumination changes, similarity transformations and extraneous features. © 2004 IEEE.

Una mirada a Egipto desde la Biblia Hebraica

Resumen: ¿Qué imágenes de Egipto encontramos en la Biblia Hebrea, además del éxodo? Los textos bíblicos miran a su vecina Egipto como país de refugio (del hambre o la persecución). Pero por ser grande y fuerte, Egipto es también proveedor de armamento militar. Puede tornarse una falsa seguridad para un pueblo que debe confiar solo en Yavé. La literatura sapiencial es más benévola. En la descripción de la cama lujosa a la que una mujer descarada atrae a su amante, Proverbios 7 ofrece un homenaje indirecto a la riqueza egipcia.

Probing biomolecular interaction forces using an anharmonic acoustic technique for selective detection of bacterial spores.

Receptor-based detection of pathogens often suffers from non-specific interactions, and as most detection techniques cannot distinguish between affinities of interactions, false positive responses remain a plaguing reality. Here, we report an anharmonic acoustic based method of detection that addresses the inherent weakness of current ligand dependant assays. Spores of Bacillus subtilis (Bacillus anthracis simulant) were immobilized on a thickness-shear mode AT-cut quartz crystal functionalized with anti-spore antibody and the sensor was driven by a pure sinusoidal oscillation at increasing amplitude. Biomolecular interaction forces between the coupled spores and the accelerating surface caused a nonlinear modulation of the acoustic response of the crystal. In particular, the deviation in the third harmonic of the transduced electrical response versus oscillation amplitude of the sensor (signal) was found to be significant. Signals from the specifically-bound spores were clearly distinguishable in shape from those of the physisorbed streptavidin-coated polystyrene microbeads. The analytical model presented here enables estimation of the biomolecular interaction forces from the measured response. Thus, probing biomolecular interaction forces using the described technique can quantitatively detect pathogens and distinguish specific from non-specific interactions, with potential applicability to rapid point-of-care detection. This also serves as a potential tool for rapid force-spectroscopy, affinity-based biomolecular screening and mapping of molecular interaction networks.

Ancient Chinese algorithm: The Ying Buzu Shu (method of surplus and deficiency) vs Newton iteration method

Air exploratory discussion of an ancient Chinese algorithm, the Ying Buzu Shu, in about 2nd century BC, known as the rule of double false position in the West is given. In addition to pointing out that the rule of double false position is actually a translation version of the ancient Chinese algorithm, a comparison with well-known Newton iteration method is also made. If derivative is introduced, the ancient Chinese algorithm reduces to the Newton method. A modification of the ancient Chinese algorithm is also proposed, and some of applications to nonlinear oscillators are illustrated.

Sobre el uso terapéutico de células estaminales de origen adulto

Resumen: Muy pocas ciencias avanzaron con la celeridad que muestran las ciencias biológicas. Hoy se abren líneas de investigación que, en poco tiempo, se aplican a los pacientes, mejorando notablemente -en la mayoría de los casos- la calidad de vida. Las terapias con células estaminales son un claro ejemplo de ello. Hoy el tema se ha instalado en la sociedad como parte de la agenda pública. Esta exposición ha llevado a la sociedad a una recepción con un lamentable doble riesgo: perder rigor científico y generar falsas expectativas en muchos pacientes. Dicha polémica también afecta las relaciones entre diversos grupos de investigadores y genera desconfianza en la comunidad científica. Desde la última mitad del siglo XX se ha instalado en las ciencias la necesidad de no escindir el campo de la investigación de las consecuencias éticas que siguen de esa praxis. La causa es evidente: la celeridad de los descubrimientos y su rápida aplicación hacen que, así como los efectos positivos alcanzan a una gran cantidad de personas, en caso de surgir efectos negativos imprevistos, el daño pueda ser igualmente multiplicado. La bioética surge así como un reclamo de los mismos investigadores que decidieron dar un cauce ético a su acción.

Un caso de auto-reescritura : El astrólogo fingido de Calderón

Resumen: La pulcra edición de la Segunda parte de comedias de Pedro Calderón de la Barca por Santiago Fernández Mosquera (Biblioteca Castro, 2007) y la reciente tesis de Fernando Rodríguez-Gallego (2009) sobre las dos versiones de El astrólogo fingido (Zaragoza, 1632 y Madrid, 1637) obligan hoy a una revisión de uno de los casos, tan frecuentes en la producción del dramaturgo madrileño, de reescritura —con miras esta vez a la publicación impresa— de una de sus obras. El examen se centrará, más allá de consideraciones formales y estéticas, en la valoración del alcance ético de las profundas transformaciones sufridas por el personaje del primer protagonista, el falso astrólogo, don Diego de Luna, así como en el análisis de las dos versiones del desenlace.

Accountability na outorga e renovação de contratos de radiodifusão : aumenta a demanda por participação social

A outorga e renovação de concessão, permissão ou autorização de serviço de radiodifusão sonora e de sons e imagens é um conjunto de decisões políticas do Poder Público que está no cerne da questão ou da problematização da comunicação no Brasil. O modelo adotado no Brasil desde cedo concentrou o poder concedente no Executivo Federal. Além de não haver uma forte accountability institucional, a população não é consultada durante o processo e não há mecanismos estabelecidos de fiscalização e controle social sobre o serviço prestado. Esse estudo tem por finalidade oferecer elementos para que se fortaleça a accountability, notadamente a social, para o exame das concessões à luz dos capítulos da comunicação na Constituição Federal. Levanta-se, como hipótese, a possibilidade de que seja falsa a dicotomia participação social versus liberdade de manifestação e de imprensa. A excessiva centralização ou a falta de participação social na outorga e renovação conduz a uma associação entre o poder concedente e os concessionários, permissionários e autorizados na radiodifusão. Os mecanismos de accountability multiplicar-se-iam com o que é chamado aqui de popularização do poder concedente e do poder concedido. E desses mecanismos poderia se servir o poder público ao examinar a eficiência e a eficácia dos "proprietários" da radiodifusão.

‘Neptune’ between ‘Hesperus’ and ‘Vulcan’: On descriptive names and non-existence

[EN]This work will focus on some aspects of descriptive names. The New Theory of Reference, in line with Kripke, takes descriptive names to be proper names. I will argue in this paper that descriptive names and certain theory in reference to them, even when it disagrees with the New Theory of Reference, can shed light on our understanding of (some) non-existence statements. I define the concept of descriptive name for hypothesised object (DNHO). My thesis being that DNHOs are, as I will specify, descriptions: a proposition expressed by the utterance ‘n is F’, where ‘n’ is a DNHO, is not singular at all; it is a descriptive proposition. To sum up, concerning proper names, the truth lies closer to the New Theory of Reference, but descriptivism is not altogether false. As for DNHOs descriptivism is, in some cases, the right fit.

Accuracy in Copy Number Calling by qPCR and PRT : A Matter of DNA

7 p.

Ganadería, trasterminancia y trashumancia en los territorios vascos en el tránsito del medievo a la modernidad (siglos XV y XVI)

[ES] El presente artículo pretende aportar nuevos datos sobre la ganadería en los territorios vascos durante la Edad Moderna. Ante todo se trata de romper con falsos paradigmas que se han venido repitiendo durante largo tiempo, aportando datos inéditos. Los clásicos de la historiografía vasca siempre han recalcado el carácter rural y agrario de la economía vasca; a pesar de ello, actividades como la ganadería jamás han ocupado un espacio primordial como objeto de estudio entre los historiadores, que en muchos casos han aceptado las teorías de etnógrafos y antropólogos sin contrastarlas. La ganadería en tierras vascas siguió modelos cantábricos, que ya vienen siendo estudiados desde algunas décadas por los historiadores gallegos, asturianos o cántabros; escuelas que han establecido nuevas metodologías para el estudio de la ganadería, las cabañas predominantes, el régimen de explotación, su impacto económico, etc., y cuyo ejemplo desgraciadamente no ha sido secundado en el caso vasco.

Spatio-Temporal Scanning and Statistical Test of the Accelerating Moment Release (AMR) Model Using Australian Earthquake Data

The Accelerating Moment Release (AMR) preceding earthquakes with magnitude above 5 in Australia that occurred during the last 20 years was analyzed to test the Critical Point Hypothesis. Twelve earthquakes in the catalog were chosen based on a criterion for the number of nearby events. Results show that seven sequences with numerous events recorded leading up to the main earthquake exhibited accelerating moment release. Two occurred near in time and space to other earthquakes preceded by AM R. The remaining three sequences had very few events in the catalog so the lack of AMR detected in the analysis may be related to catalog incompleteness. Spatio-temporal scanning of AMR parameters shows that 80% of the areas in which AMR occurred experienced large events. In areas of similar background seismicity with no large events, 10 out of 12 cases exhibit no AMR, and two others are false alarms where AMR was observed but no large event followed. The relationship between AMR and Load-Unload Response Ratio (LURR) was studied. Both methods predict similar critical region sizes, however, the critical point time using AMR is slightly earlier than the time of the critical point LURR anomaly.

Charles M. Breder, Jr.: Atlantis Expedition, 1934

Dr. Charles M. Breder participated on the 1934 expedition of the Atlantis from Woods Hole, Massachusetts to Panama and back and kept a field diary of daily activities. The Atlantis expedition of 1934, led by Prof. A. E. Parr, was a milestone in the history of scientific discovery in the Sargasso Sea and the West Indies. Although naturalists had visited the Sargasso Sea for many years, the Atlantis voyage was the first attempt to investigate in detailed quantitative manner biological problems about this varying, intermittent ‘false’ bottom of living, floating plants and associated fauna. In addition to Dr. Breder, the party also consisted of Dr. Alexander Forbes, Harvard University and Trustee of the Woods Hole Oceanographic Institution (WHOI); T. S. Greenwood, WHOI hydrographer; M. D. Burkenroad, Yale University’s Bingham Laboratory, carcinology and Sargasso epizoa; M. Bishop, Peabody Museum of Natural History, Zoology Dept., collections and preparations and H. Sears, WHOI ichthyologist. The itinerary included the following waypoints: Woods Hole, the Bermudas, Turks Islands, Kingston, Colon, along the Mosquito Bank off of Nicaragua, off the north coast of Jamaica, along the south coast of Cuba, Bartlett Deep, to off the Isle of Pines, through the Yucatan Channel, off Havana, off Key West, to Miami, to New York City, and then the return to Woods Hole. During the expedition, Breder collected rare and little-known flying fish species and developed a method for hatching and growing flying fish larvae. (PDF contains 48 pages)

Comments on hydrographic and topographic LIDAR acquisition and merging with multibeam sounding data acquired in the Olympic Coast National Marine Sanctuary

In April 2005, a SHOALS 1000T LIDAR system was used as an efficient alternative for safely acquiring data to describe the existing conditions of nearshore bathymetry and the intertidal zone over an approximately 40.7 km2 (11.8 nm2) portion of hazardous coastline within the Olympic Coast National Marine Sanctuary (OCNMS). Data were logged from 1,593 km (860 nm) of track lines in just over 21 hours of flight time. Several islands and offshore rocks were also surveyed, and over 24,000 geo-referenced digital still photos were captured to assist with data cleaning and QA/QC. The 1 kHz bathymetry laser obtained a maximum water depth of 22.2 meters. Floating kelp beds, breaking surf lines and turbid water were all challenges to the survey. Although sea state was favorable for this time of the year, recent heavy rainfall and a persistent low-lying layer of fog reduced acquisition productivity. The existence of a completed VDatum model covering this same geographic region permitted the LIDAR data to be vertically transformed and merged with existing shallow water multibeam data and referenced to the mean lower low water (MLLW) tidal datum. Analysis of a multibeam bathymetry-LIDAR difference surface containing over 44,000 samples indicated surface deviations from –24.3 to 8.48 meters, with a mean difference of –0.967 meters, and standard deviation of 1.762 meters. Errors in data cleaning and false detections due to interference from surf, kelp, and turbidity likely account for the larger surface separations, while the remaining general surface difference trend could partially be attributed to a more dense data set, and shoal-biased cleaning, binning and gridding associated with the multibeam data for maintaining conservative least depths important for charting dangers to navigation. (PDF contains 27 pages.)

Colonization and development of Oribatida mite communities (Acari: Oribatida) in the forest reclaimed limestone mine dumps

In order to study the colonization and development of moss mites (Oribatida) communities in a Scots pine forest of a reclaimed limestone mine dump in Northern Poland, 3 plots from the dump were chosen. The selected plots differed in age, 5 years old, 35 and 50 years old. From a total of 30 samples 499 mites (Acari) were extracted in Tullgren funnel from which 262 were Oribatida. Abundance (N) was analyzed in all mites and after determining the species of both, juvenile and adult stages of oribatids, the following indices were analyzed: Abundance (N), Dominance (D), Species diversity (S), Species richness (s) and Shannon’s diversity index (H). Regarding to the results obtained; oribatid mites were dominant with the highest abundance in all assemblages (Plot 1: 139 Oribatida /299 Acari. Plot 2: 40/55 and Plot 3: 83/145). Tectocepheus velatus showed a very high dominance (45,99%) in plot 1; the highest value for Shannon’s diversity index belonged to plot 3. On the other hand, juvenile’s percentage was significantly higher than adult’s percentage, especially at plot 2 (95,02%). These results made us to conclude that the high abundance of oribatids in the youngest forest is due to T. velatus’s high abundance and that plot 3 is the best habitat for mites. Finally, the high occurrence of juvenile stages requires keeping on studying the area.

Abundance and distribution patters of Hawaiian odontocetes: focus on O'ahu

This dissertation is an assessment of the status of odontocetes in Hawaiian waters focussing on O´ahu. The work builds on available literature, and on data collected by the author and by others in Hawaiian waters. Abundance and distribution patterns of odontocetes were derived from stranding and aerial survey data. A stranding network operated by the National Marine Fisheries Service, Pacific Area Office collected 187 stranding reports throughout the main Hawaiian Islands between 1937 and 2002. These reports included 16 odontocete species. Number of stranding reports increased over time and was highest on O´ahu. Strandings occurred throughout the year. The difference in number of strandings per month was not significant. Fifteen of the 16 species reported in the stranding record for the main Hawaiian Islands were also reported by aerial survey studies of the area between 1993 and 1998. Only 7 of the species reported were detected during aerial transects around O′ahu between 1998 and 2000. Based on the stranding record, Kogia sp., melon-headed whales, striped dolphins and dwarf killer whale appear to be more common than suggested by aerial surveys. Conversely, pilot whales and bottlenose dolphins were more common, according to aerial surveys, than predicted by the stranding data. Aerial surveys of waters between 0 and 500m around the Island of O′ahu showed that the most abundant species by frequency of occurrence was the pilot whale (30% of sightings), followed by the spinner (16%) and bottlenose dolphin (14%). Because of small sample size, abundance estimates for odontocetes have a high level of uncertainty. The unavailability of a correction factor for g(0)<1, and the reduced visibility below the aircraft further reduced accuracy and increased the inherent underestimation in the data. The most abundant species according to distance sampling estimates were spotted dolphins, pilot whales, false killer whales and spinner dolphins. A natural factor shaping the ecology of odontocete populations is predation pressure both by other odontocetes and, more frequently, by sharks. An account of predation by a tiger shark on a spotted dolphin near Penguin Banks is used as an example of the potential mechanisms of predation by sharks on odontocetes.