Location of planar targets in three space from monocular images

Many pieces of existing and proposed space hardware that would be targets of interest for a telerobot can be represented as planar or near-planar surfaces. Examples include the biostack modules on the Long Duration Exposure Facility, the panels on Solar Max, large diameter struts, and refueling receptacles. Robust and temporally efficient methods for locating such objects with sufficient accuracy are therefore worth developing. Two techniques that derive the orientation and location of an object from its monocular image are discussed and the results of experiments performed to determine translational and rotational accuracy are presented. Both the quadrangle projection and elastic matching techniques extract three-space information using a minimum of four identifiable target points and the principles of the perspective transformation. The selected points must describe a convex polygon whose geometric characteristics are prespecified in a data base. The rotational and translational accuracy of both techniques was tested at various ranges. This experiment is representative of the sensing requirements involved in a typical telerobot target acquisition task. Both techniques determined target location to an accuracy sufficient for consistent and efficient acquisition by the telerobot

Functional characterization of mammalian NDR kinase deficiency : novel functions and insights into downstream signaling mechanisms

Protein kinases are important players in signal transduction. They are involved in the regulation of almost every aspect of biological regulation. Given their central role in signal transduction, aberrant protein kinase activities are involved in a variety of human diseases, such as diabetes or cancer. The human genome encodes for 518 protein kinases, which are further classified into groups, families and sub-families based on their catalytic domain. The NDR kinase family belongs to the AGC group (protein kinase A/G/C like) of serine/threonine kinases. Members of this family are highly conserved from yeast to men. Genetical and biochemical work on NDR kinases in yeast and invertebrates revealed, that NDR kinases are involved in the regulation of important biological processes such as mitotic exit, morphogenesis, neuronal and epithelial morphology, growth, proliferation and apoptosis amongst others. Although NDR kinases are implicated in a variety of biological processes amongst species, the topology of the signaling pathways regulating NDR kinases are remarkably conserved. NDR kinases from yeast to men are regulated by members of the Ste20 like kinases, MOB adaptor proteins and scaffolding proteins. The human genome encodes for 4 members of the NDR kinase family: NDR1, NDR2, LATS1 and LATS2. Although many of the biochemical mechanisms regulating NDR kinases have been worked out using human NDR1 and NDR2, functions for these two kinases have only been reported recently: Human NDR has been shown to function in centrosome duplication, the alignment of mitotic chromosomes and apoptosis signaling. Defects in regulation of these processes have been linked to tumor development. However, these functions were investigated using cell culture systems and physiological functions for NDR1 and NDR2 remain to be defined. Interestingly, NDR1 in these contexts has been shown to be regulated by components of the HIPPO tumor suppressor pathway. The tumor suppressor proteins Rassf1a, MST1/2 and hMOB1 have been shown to not only regulate NDR kinase activity, but also the activity of the other NDR family members LATS1 and LATS2. LATS kinases function as tumor suppressors by restricting the activity of the YAP oncogene. Given the interaction with known components of the HIPPO pathway, a tumor suppressive function for NDR1 and NDR2 seems possible. However, although first functions for human NDR kinases have been defined recently, signaling mechanisms downstream of NDR1 and NDR2 remain elusive. Addressing two of the major questions relating to mammalian NDR kinases, we define a first physiological function for NDR kinases in mice in tumor suppression. Deficiency and heterozygosity of NDR1 predisposes mice to T-cell lymphoma development. Reduction of NDR kinase expression results in increased resistance to pro-apoptotic stimuli. Furthermore we identify a novel role for NDR1 and NDR2 in the regulation of cell cycle progression. NDR1/2 directly regulate the protein stability of the proto-oncogene c-myc and the cyclin-dependent kinase inhibitor p21. Mammalian NDR kinases therefore seem to play important roles in tumor and cell biology by regulating proliferation and apoptosis

Avanços, esgotamento e inflexão necessária. Somos um país da alegria e da alegoria não somos um país da liberdade e da felicidade.

Hoje em dia, quem descreve a mente do povo são as estatísticas com base em pesquisas de opinião, com a mesma segurança de quem usa termômetro para aferir a temperatura do corpo. Cometem dois erros: não captam a mente, e não observam a complexidade social nem a amplitude histórica de como vai se formando a maneira como um povo “pensa” e “sente”.Este texto não usa termômetro, consciente da visão deformada de um mergulhador dentro da água, ele procura mergulhar na mente do povo brasileiro, mas sem aceitar a descrição do mar feita desde as praias: os livros, as salas de aula, as bibliotecas ou os sites da internet.É difícil saber se essas ideias servirão de base para despertar uma indignação ética com a realidade, ou se elas foram produto dessa indignação. Mas dificilmente seriam escritas sem que houvesse, em sua origem, uma forte e incômoda indignação com a realidade do Brasil

Developing an economic development policy : the evolution and impact of a new DOE mission

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.Includes bibliographical references (leaves 89-95).by Kristine N. Cornils.M.S

An Improved Equivalent Simulation Model for CMOS Integrated Hall Plates

An improved equivalent simulation model for a CMOS-integrated Hall plate is described in this paper. Compared with existing models, this model covers voltage dependent non-linear effects, geometrical effects, temperature effects and packaging stress influences, and only includes a small number of physical and technological parameters. In addition, the structure of this model is relatively simple, consisting of a passive network with eight non-linear resistances, four current-controlled voltage sources and four parasitic capacitances. The model has been written in Verilog-A hardware description language and it performed successfully in a Cadence Spectre simulator. The model’s simulation results are in good agreement with the classic experimental results reported in the literature

Global phylogeography of Oithona similis s.l. (Crustacea, Copepoda, Oithonidae) – A cosmopolitan plankton species or a complex of cryptic lineages?

Traditionally, many small-sized copepod species are considered to be widespread, bipolar or cosmopoli- tan. However, these large-scale distribution patterns need to be re-examined in view of increasing evi- dence of cryptic and pseudo-cryptic speciation in pelagic copepods. Here, we present a phylogeographic study of Oithona similis s.l. populations from the Arctic Ocean, the Southern Ocean and its northern boundaries, the North Atlantic and the Mediterrranean Sea. O. similis s.l. is considered as one of the most abundant species in temperate to polar oceans and acts as an important link in the trophic network between the microbial loop and higher trophic levels such as fish larvae. Two gene frag- ments were analysed: the mitochondrial cytochrome oxidase c subunit I (COI), and the nuclear ribosomal 28 S genetic marker. Seven distinct, geographically delimitated, mitochondrial lineages could be identi- fied, with divergences among the lineages ranging from 8 to 24%, thus representing most likely cryptic or pseudocryptic species within O. similis s.l. Four lineages were identified within or close to the borders of the Southern Ocean, one lineage in the Arctic Ocean and two lineages in the temperate Northern hemi- sphere. Surprisingly the Arctic lineage was more closely related to lineages from the Southern hemi- sphere than to the other lineages from the Northern hemisphere, suggesting that geographic proximity is a rather poor predictor of how closely related the clades are on a genetic level

Neustonic copepods (Labidocera spp.) discovered living residentially in coral reefs

Pontellid copepods are archetypical representatives of the neuston — the highly specialized community living in the top 5–10 cm of the ocean surface. Their deep blue pigmentation and large eyes are unique adaptations to surface irradiation and carnivory, but poor prerequisites for survival in the transparent waters beneath the sea surface. Here, we report the discovery of three reef-associated representatives of this group — Labidocera bataviae A. Scott, 1909; L. pavo Giesbrecht, 1889; and Labidocera sp. — living residential in coral reefs. We (1) document the presence of Labidocera spp. for two separate coral reefs on two expeditions to Papua New Guinea, (2) describe their migration behavior and substrate preference, and (3) quantify the effects of benthic reef community composition on their abundance. All life stages of Labidocera spp. were 43 to 94 times more abundant at the reef sites compared to offshore sites. Although pontellids are generally considered non-migrators, Labidocera spp. showed discernible diel vertical migrations: living in reef substrates during the day, emerging into the water column at night (sometimes more than once), and returning to the substrate at dawn. Labidocera spp. showed a pronounced substrate preference for coral rubble, microalgae, and turf, over branching coral, massive boulder coral, and sand