Orbital navigation, docking and obstacle avoidance as a form of three dimensional model-based image understanding

Range imagery from a laser scanner can be used to provide sufficient information for docking and obstacle avoidance procedures to be performed automatically. Three dimensional model-based computer vision algorithms in development can perform these tasks even with targets which may not be cooperative (that is, objects without special targets or markers to provide unambiguous points). Role, pitch, and yaw of a vehicle can be taken into account as image scanning takes place, so that these can be correlated when the image is converted from egocentric to world coordinated. Other attributes of the sensor, such as the registered reflectance and texture channels, provide additional data sources for algorithm robustness

Two essays on the universal and particular dimensions of culture

The first of the two essays was presented at the conference 'Ethnicity in an Age of Globalisation', held at Uganda Martyrs University, Kampala, Uganda, from 3-6 September 2001.Thesis (MA)--University of Stellenbosch, 2002.Babel or Piraeus? : globalisation, culture and tradition -- Between freedom and culture : Alain Finkielkraut's critique of multiculturalism.ENGLISH ABSTRACT: The conception of globalisation as a "programme" or "project" driven by a group of people or companies with a set agenda underlies much of the antagonistic discussion of globalisation. Protagonists of globalisation, in turn, often describe the process as inevitable progress. This paper analyses the process of globalisation and argues that it should not be understood as such a singular process. Rather, the concept "complex connectivity" - where the local and the global come' into closer contact and influence, or interpenetrate, one another more directly - facilitates a more nuanced analysis of globalisation -.This understanding of globalisation will be tested against the phenomenon of culture by posing two questions: Does globalisation lead to the destruction of local culture( s) by an encroaching singular global culture (i.e. is globalisation cultural imperialism)? Or alternatively: Does globalisation represent an opening .up and exchange between previously isolated cultures and societies? This paper argues in favour of the second position by employing John Tomlinson's existential definition of culture and his understanding of the dialectic that exists between the local and the global in complex connectivity. Instead of global culture, we can more properly speak of . "globalized" culture, which looks different in every local situation. This is a more optimistic answer to the cultural' effects of globalisation, and although some concerns remain, it seems clear that to understand globalisation as complex connectivity rules out many of the charges of cultural imperialism lodged against globalisation.AFRIKAANSE OPSOMMING: Baie van die hedendaagse antagonistiese diskussie oor globalisasie gaan uit van die veronderstelling dat globalisasie 'n 'program' of 'n 'projek' is wat deur 'n groep individue of maatskappye gedryf word. Voorstanders van globalisasie, daarenteen, beskou die proses dikwels as 'onafwendbare vooruitgang.' Hierdie opstel analiseer die proses van globalisasie en argumenteer dat globalisasie nie as so 'n eenduidige process verstaan moet word nie. Die konsep "complex connectivity" word ingespan om 'n meer genuanseerde analise van globalisasie te bied aangesien dit dui op die komplekse interaksie, of selfs interpenetrasie, tussen plaaslike en globale prosesse. Hierdie opvatting oor globalisasie word getoets aan die hand van kultuur deur twee teenstellende vrae te stel: Is globalisasie 'n enkelvoudige globale kultuur wat dreig om plaaslike kulture oor te neem en uiteindelik te vernietig (ook genoem kultuurimperialisme)? Of eerder: Is globalisasie 'n geleentheid tot groter openheid en interaksie tussen kulture en gemeenskappe wat voorheen van mekaar geïsoleer was? Die opstel argumenteer ten gunste van die tweede posisie deur gebruik te maak van John Tomlinson se eksistensiële definisie van kultuur en sy opvatting oor die interaksie tussen die plaaslike en die globale. Instede van globale kultuur kan ons eerder praat van 'geglobaliseerde' kultuur, wat telkens anders lyk in elke plaaslike opset. Hierdie posisie bied 'n versigtige, maar meer optimistiese antwoord op die kulturele impak van globalisasie deurdat veel van die aanklagte van kultuurimperialsime teen globalisasie afgewys word

On the control of acute rodent malaria infections by innate immunity

Does specific immunity, innate immunity or resource (red blood cell) limitation control the first peak of the blood-stage parasite in acute rodent malaria infections? Since mice deficient in specific immunity exhibit similar initial dynamics as wild-type mice it is generally viewed that the initial control of parasite is due to either limitation of resources (RBC) or innate immune responses. There are conflicting views on the roles of these two mechanisms as there is experimental evidence supporting both these hypotheses. While mathematical models based on RBC limitation are capable of describing the dynamics of primary infections, it was not clear whether a model incorporating the key features of innate immunity would be able to do the same. We examine the conditions under which a model incorporating parasite and innate immunity can describe data from acute <i>Plasmodium chabaudi</i> infections in mice. We find that innate immune response must decay slowly if the parasite density is to fall rather than equilibrate. Further, we show that within this framework the differences in the dynamics of two parasite strains are best ascribed to differences in susceptibility to innate immunity, rather than differences in the strains' growth rates or their propensity to elicit innate immunity. We suggest that further work is required to determine if innate immunity or resource limitation control acute malaria infections in mice

Crumbs 2 prevents cortical abnormalities in mouse dorsal telencephalon

AbstractThe formation of a functionally integrated nervous system is dependent on a highly organized sequence of events that includes timely division and differentiation of progenitors. Several apical polarity proteins have been shown to play crucial roles during neurogenesis, however, the role of Crumbs 2 (CRB2) in cortical development has not previously been reported.Here, we show that conditional ablation of Crb2 in the murine dorsal telencephalon leads to defects in the maintenance of the apical complex. Furthermore, within the mutant dorsal telencephalon there is premature expression of differentiation proteins. We examined the physiological function of Crb2 on wild type genetic background as well as on background lacking Crb1. Telencephalon lacking CRB2 resulted in reduced levels of PALS1 and CRB3 from the apical complex, an increased number of mitotic cells and expanded neuronal domain. These defects are transient and therefore only result in rather mild cortical abnormalities. We show that CRB2 is required for maintenance of the apical polarity complex during development of the cortex and regulation of cell division, and that loss of CRB2 results in cortical abnormalities

Burdigalian deposits of the Santa Cruz Formation in the Sierra Baguales, Austral (Magallanes) Basin: Age, depositional environment and vertebrate fossils

Indexación: Web of Science; Scielo.ABSTRACT. A succession of marine and continental strata on the southern flank of Cerro Cono in the Sierra Baguales, northeast of Torres del Paine, can be correlated with stratigraphic units exposed along the southern border of the Lago Argentino region in Santa Cruz Province, Argentina. These include the Estancia 25 de Mayo Formation and the basal part of the Santa Cruz Formation. The lithological correlation is also confirmed by detrital zircon ages (maximum age of 18.23±0.26 Ma) and a rich assemblage of terrestrial vertebrate fossils, biostratigraphically equivalent to a postColhuehuapian, pre-Santacrucian South American Land Mammal Age (SALMA) fauna, suggesting a range of 19 to 17.8 Ma. Similar ages have been obtained from the basal part of the Santa Cruz Formation at Estancia Quién Sabe in southwestern Argentina, supporting the assumption of a regional continuity between these deposits. A measured lithostratigraphic column is presented and the depositional environment is interpreted as a coastal plain with small, meandering rivers and ephemeral floodplain lakes. The sedimentation coincides with intensified uplift of the Patagonian Andes during the ‘Quechua Phase’ of Andean tectonism, which is reflected by a change in paleocurrent directions from northwest to east-northeast. Keywords: Burdigalian, Santa Cruz Formation, Santacrucian SALMA, ‘Notohippidian’ fauna, Meandering rivers.RESUMEN. Una sucesión de estratos marinos y continentales en el flanco meridional del cerro Cono, en la sierra Baguales, al noreste de Torres del Paine, se correlaciona con estratos al sur de la región de lago Argentino en la Provincia de Santa Cruz, República Argentina. Estas unidades incluyen la Formación Estancia 25 de Mayo y la parte basal de la Formación Santa Cruz. La correlación litológica es, además, confirmada por datación de circones detríticos (edad máxima de 18,23±0,26 Ma) y un variado ensamble de vertebrados fósiles terrestres de edad post-Colhuehuapense a pre-Santacrucense en la escala de Edades Mamífero Sudamericanas (EMAS), con un rango temporal de entre 19 a 17,8 Ma. Edades similares han sido reportadas para la parte basal de la Formación Santa Cruz, en estancia Quién Sabe, en el suroeste de Argentina, ratificando la continuidad regional entre estos depósitos. Se presenta una columna estratigráfica y se interpreta el ambiente de depositación como una llanura costera con pequeños ríos sinuosos y lagos efímeros. La edad de sedimentación coincide con el solevantamiento de los Andes Patagónicos durante la 'Fase Quechua', lo que se ve reflejado por un cambio en la dirección de las paleocorrientes desde el noroeste hacia el este-noreste.http://ref.scielo.org/csxwd

Phytochemical changes in milkweed induced by elevated CO2 alter wing morphology but not toxin sequestration in monarch butterflies

Environmental change has the potential to influence trophic interactions by altering the defensive phenotype of prey.Here, we examine the effects of a pervasive environmental change driver, elevated atmospheric concentrations of CO2 (eCO2), on toxin sequestration and flight morphology of a specialist herbivore.We fed monarch butterfly larvae, Danaus plexippus, foliage from four milkweed, Asclepias, species of varying chemical defence profiles grown under either ambient or eCO2. We also infected a subset of these herbivores with a protozoan parasite, Ophryocystis elektroscirrha, to understand how infection and environmental change combine to alter herbivore defences. We measured changes in phytochemistry induced by eCO2 and assessed cardenolide, toxic steroid, sequestration and wing morphology of butterflies.Monarchs compensated for lower plant cardenolide concentrations under eCO2 by increasing cardenolide sequestration rate, maintaining similar cardenolide composition and concentrations in their wings under both CO2 treatments. We suggest that these increases in sequestration rate are a by‐product of compensatory feeding aimed at maintaining a nutritional target in response to declining dietary quality under eCO2.Monarch wings were more suitable for sustained flight (more elongated) when reared on plants grown under eCO2 or when reared on Asclepias syriaca or Asclepias incarnata rather than on Asclepias curassavica or Asclepias speciosa. Parasite infection engendered wings less suitable for sustained flight (wings became rounder) on three of four milkweed species. Wing loading (associated with powered flight) was higher on A. syriaca than on other milkweeds, whereas wing density was lower on A. curassavica. Monarchs that fed on high cardenolide milkweed developed rounder, thinner wings, which are less efficient at gliding flight.Ingesting foliage from milkweed high in cardenolides may provide protection from enemies through sequestration yet come at a cost to monarchs manifested as lower quality flight phenotypes: rounder, thinner wings with lower wing loading values.Small changes in morphology may have important consequences for enemy evasion and migration success in many animals. Energetic costs associated with alterations in defence and morphology may, therefore, have important consequences for trophic interactions in a changing world.A plain language summary is available for this article.Plain Language SummaryPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/1/fec13270-sup-0006-TableS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/2/fec13270-sup-0003-FigS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/3/fec13270-sup-0004-FigS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/4/fec13270-sup-0002-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/5/fec13270-sup-0008-TableS4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/6/fec13270-sup-0005-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/7/fec13270-sup-0009-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/8/fec13270_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/9/fec13270-sup-0001-Summary.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/10/fec13270.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/11/fec13270-sup-0007-TableS3.pd

Chapter Modern Orthopaedic Implant Coatings — Their Pro’s, Con’s and Evaluation Methods

Environmental monitorin