On Advanced Mobility Concepts for Intelligent Planetary Surface Exploration

Surface exploration by wheeled rovers on Earth's Moon (the two Lunokhods) and Mars (Nasa's Sojourner and the two MERs) have been followed since many years already very suc-cessfully, specifically concerning operations over long time. However, despite of this success, the explored surface area was very small, having in mind a total driving distance of about 8 km (Spirit) and 21 km (Opportunity) over 6 years of operation. Moreover, ESA will send its ExoMars rover in 2018 to Mars, and NASA its MSL rover probably this year. However, all these rovers are lacking sufficient on-board intelligence in order to overcome longer dis-tances, driving much faster and deciding autonomously on path planning for the best trajec-tory to follow. In order to increase the scientific output of a rover mission it seems very nec-essary to explore much larger surface areas reliably in much less time. This is the main driver for a robotics institute to combine mechatronics functionalities to develop an intelligent mo-bile wheeled rover with four or six wheels, and having specific kinematics and locomotion suspension depending on the operational terrain of the rover to operate. DLR's Robotics and Mechatronics Center has a long tradition in developing advanced components in the field of light-weight motion actuation, intelligent and soft manipulation and skilled hands and tools, perception and cognition, and in increasing the autonomy of any kind of mechatronic systems. The whole design is supported and is based upon detailed modeling, optimization, and simula-tion tasks. We have developed efficient software tools to simulate the rover driveability per-formance on various terrain characteristics such as soft sandy and hard rocky terrains as well as on inclined planes, where wheel and grouser geometry plays a dominant role. Moreover, rover optimization is performed to support the best engineering intuitions, that will optimize structural and geometric parameters, compare various kinematics suspension concepts, and make use of realistic cost functions like mass and consumed energy minimization, static sta-bility, and more. For self-localization and safe navigation through unknown terrain we make use of fast 3D stereo algorithms that were successfully used e.g. in unmanned air vehicle ap-plications and on terrestrial mobile systems. The advanced rover design approach is applica-ble for lunar as well as Martian surface exploration purposes. A first mobility concept ap-proach for a lunar vehicle will be presented

Specific heat amplitude ratios for anisotropic Lifshitz critical behaviors

We determine the specific heat amplitude ratio near a $m$-axial Lifshitz point and show its universal character. Using a recent renormalization group picture along with new field-theoretical $\epsilon_{L}$-expansion techniques, we established this amplitude ratio at one-loop order. We estimate the numerical value of this amplitude ratio for $m=1$ and $d=3$. The result is in very good agreement with its experimental measurement on the magnetic material $MnP$. It is shown that in the limit $m \to 0$ it trivially reduces to the Ising-like amplitude ratio.Comment: 8 pages, RevTex, accepted as a Brief Report in Physical Review

Modélisation de l'évolution thermique saisonnière du lac du Bourget

Le lac du Bourget, l'un des principaux lacs alpins situé en France, a fait l'objet en 1981 d'importants travaux d'aménagement en vue de ta restauration de la qualité de ses eaux. Une campagne de mesure portant sur les années 1988-89 a été mise en place afin de faire le point sur l'évolution du lac depuis la fin des travaux.Un modèle thermique et biogéochimique (phosphore, oxygène, azote) sera utilisé pour synthétiser les connaissances, prévoir l'évolution de la qualité des eaux du lac ainsi que l'influence d'éventuels aménagements complémentaires. Les résultats présentés ici concernent la première étape du projet d'études, la modélisation thermique du lac du Bourget.Le modèle utilisé est un modèle unidimensionnel, vertical, basé sur l'équation d'advection-diffusion.L'expression des coefficients de dispersion selon la profondeur reprend celle d'un modèle du lac Léman (Tassin, 1986). Les équations utilisées distinguent l'épilimnion, le métalimnion et l'hypolimnion.Les résultats présentés montrent que le modèle décrit de façon satisfaisante le cycle thermique annuel et l'évolution inter-annuelle des températures dans le lac du Bourget.Les profils et les valeurs des coefficients de dispersion calculés sur le lac du Bourget sont proches de ceux obtenus sur d'autres lacs à partir de mesures fines de température ou de concentrations d'isotopes naturels.Les coefficients de dispersion obtenus pourront donc être utilisés dans la modélisation des substances dissoutes dans le lac.In 1981, important works including the diversion of the main sewers entering Lake Bourget (one of the largest French alpine lakes) were undertaken in order to restore acceptable water quality standards. A detailed water quality survey will be performed in 1988-89 to complete the data base which already covers ten years. It should help in quantifying the evolution of the lake since the 1981 restoration works. The following activities will be undertaken as part of the survey : measurements within the water column, a study of the bottom sediments, the setting-up of sediment traps and the coupling of Landsat satellite images with measurements performed at some stations at the lake surface. A thermal and biogeochemical (phosphorus, oxygen, nitrogen) model will be used to summarise the information available and to forecast the evolution of water quality and the effect of other restoration measures. This paper reports on the first part of the study : the thermal modelling of Lake Bourget. A one-dimensional, vertical model based on the advection-diffusion equation is used. This equation is solved using a finite difference, semi-implicit method. The resolution grid has 145 layers (1 meter high) and the time step is 3 hours.The heat fluxes at the air-water interface are computed with the three-hourly meteorological data collected at the Chambéry airport station, at the south end of the lake. The formulas are empirical and well established in the literature.The expression for the eddy diffusion coefficients is based on a model of the lake of Geneva (Tassin, 1986). Different equations are used for the epilimnion, metalimnion and hypolimnion. In the epilimnion, the eddy diffusion coefficient expresses, by the Richardson gradients number, the interaction between the shear stress of the wind and the water column stability. It depends on the value of the eddy diffusion in neutral conditions and on a stability function which includes the Richardson number. The vertical profile of the horizontal number. The vertical profile of the horizontal currents is computed following Ekman (1905) and Simons (1981) and is approximated by a gradient which decays exponentially.In the metalimnion and the hypolimnion, the water layer stability is characterised by the Brünt-Väisälä frequency. In the hypolimnion, the eddy diffusion coefficient includes a corrective term, which is a function of depth; this term serves to reduce the dispersion near the bottom of the lake.The thermal model also includes the mixing of the first layers by waves, the vertical advective transport induced by rivers inflows into the lake and by surface water withdrawal, as well as the thermal convection induced by local instabilities of the water column.The eight parameters occurring in the heat flux equations and the eddy diffusion coefficients were estimated using data from 1981. The model has been validated over an 8 years period 1976-1983).Results of the model agree with the observed seasonal and long-term evolutions of temperature in Lake Bourget. The main characteristics of the annual cycle are reproduced : set-up of the thermocline in spring, depth of the epilimnion, thermocline and metalimnion, value of the temperature gradient in the metalimnion, deepening of the thermocline in fall and winter overturn. Significant differences between observed and simulated temperatures occur in the metalimnion and they may be partially explained by internal waves which are dominant features at this level during summer stratification. This kind of mechanism cannot be accounted for in a one-dimensional vertical model.Profiles and values of eddy diffusion coefficients calculated for Lake Bourget show a good agreement with those obtained in other large takes from measurements of temperature or natural isotopes concentrations.In general, the thermal model gives a good account of heat transport mechanisms in Lake Bourget. Accordingly, it provides acceptable dispersion coefficients which can be used to model the distribution of dissolved species in the lake

A Microarray study of Carpet-Shell Clam (Ruditapes decussatus) shows common and organ-specific growth-related gene expression Differences in gills and digestive gland

Growth rate is one of the most important traits from the point of view of individual fitness and commercial production in mollusks, but its molecular and physiological basis is poorly known. We have studied differential gene expression related to differences in growth rate in adult individuals of the commercial marine clam Ruditapes decussatus. Gene expression in the gills and the digestive gland was analyzed in 5 fast-growing and five slow-growing animals by means of an oligonucleotide microarray containing 14,003 probes. A total of 356 differentially expressed genes (DEG) were found. We tested the hypothesis that differential expression might be concentrated at the growth control gene core (GCGC), i. e., the set of genes that underlie the molecular mechanisms of genetic control of tissue and organ growth and body size, as demonstrated in model organisms. The GCGC includes the genes coding for enzymes of the insulin/ insulin-like growth factor signaling pathway (IIS), enzymes of four additional signaling pathways (Raf/ Ras/ Mapk, Jnk, TOR, and Hippo), and transcription factors acting at the end of those pathways. Only two out of 97 GCGC genes present in themicroarray showed differential expression, indicating a very little contribution of GCGC genes to growth-related differential gene expression. Forty eight DEGs were shared by both organs, with gene ontology (GO) annotations corresponding to transcription regulation, RNA splicing, sugar metabolism, protein catabolism, immunity, defense against pathogens, and fatty acid biosynthesis. GO termenrichment tests indicated that genes related to growth regulation, development and morphogenesis, extracellular matrix proteins, and proteolysis were overrepresented in the gills. In the digestive gland overrepresented GO terms referred to gene expression control through chromatin rearrangement, RAS-related small GTPases, glucolysis, and energy metabolism. These analyses suggest a relevant role of, among others, some genes related to the IIS, such as the ParaHox gene Xlox, CCAR and the CCN family of secreted proteins, in the regulation of growth in bivalves.Direccion General de Investigacion Cientifica y Tecnica of the Spanish Government [AGL2010-16743, AGL2013-49144-C3-3-R]; COMPETE Program; Portuguese National Funds [PEst-255 C/MAR/LA0015/2011]; Portuguese FCT [UID/Multi/04326/2013]; Generalitat Valenciana; Ministry of Education, Culture, and Sports of the Spanish Government; Association of European Marine Biology Laboratoriesinfo:eu-repo/semantics/publishedVersio

Doenças do girassol.

Mancha de Alternaria - Alternaria spp.; Podridao branca - Sclerotinia sclerotiorum (Lib.) de Bary; Mildio - Plasmopara halstedii (Farl.) Berl. & de Toni; Ferrugem - Puccinia helianthi Schw.; Bolha branca - Albugo tragopogi (Pers.) Schroet; Oidio - Erysiphe cichoracearum DC; Mancha cinzenta da haste - Phomopsis helianthi Munth. - Cvet. et al.; Mancha preta da haste - Phoma oleracea var. helianthi tuberosi Sacc.; Outras podridoes radiculares e murchas - Sclerotium rolfsii Sacc., Macrophomina phaseolina (Tass.) Goid e Verticillium dahliae Klebahn; Podridao cinza do capitulo - Botrytis cinerea Pers. ex Fr.; Mancha bacteriana e crestamento bacteriano - Pseudomonas syringae pv. helianthi (Kawamura) Dye, Wilkie et Young; Pseudomonas cichorii (Swingle) Stapp; Podridao da medula da haste - Erwinia sp.; Mosaico comum do girassol - virus do mosaico do picao ("sunflower mosaic virus"); Controle de doencas.bitstream/item/40506/1/Doencas-do-girassol.pd

A Nuclear Physics Program at the ATLAS Experiment at the CERN Large Hadron Collider

The ATLAS collaboration has significant interest in the physics of ultra-relativistic heavy ion collisions. We submitted a Letter of Intent to the United States Department of Energy in March 2002. The following document is a slightly modified version of that LOI. More details are available at: http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/SM/ionsComment: Letter of Intent submitted to the United States Department of Energy Nuclear Physics Division in March 2002 (revised version

A new picture of the Lifshitz critical behavior

New field theoretic renormalization group methods are developed to describe in a unified fashion the critical exponents of an m-fold Lifshitz point at the two-loop order in the anisotropic (m not equal to d) and isotropic (m=d close to 8) situations. The general theory is illustrated for the N-vector phi^4 model describing a d-dimensional system. A new regularization and renormalization procedure is presented for both types of Lifshitz behavior. The anisotropic cases are formulated with two independent renormalization group transformations. The description of the isotropic behavior requires only one type of renormalization group transformation. We point out the conceptual advantages implicit in this picture and show how this framework is related to other previous renormalization group treatments for the Lifshitz problem. The Feynman diagrams of arbitrary loop-order can be performed analytically provided these integrals are considered to be homogeneous functions of the external momenta scales. The anisotropic universality class (N,d,m) reduces easily to the Ising-like (N,d) when m=0. We show that the isotropic universality class (N,m) when m is close to 8 cannot be obtained from the anisotropic one in the limit d --> m near 8. The exponents for the uniaxial case d=3, N=m=1 are in good agreement with recent Monte Carlo simulations for the ANNNI model.Comment: 48 pages, no figures, two typos fixe