The secondary structures of the Xenopus laevis and human mitochondrial small ribosomal subunit RNA are similar

AbstractExtensive corrections of the nucleotide sequence of the Xenopuslaevis mitochondrial small ribosomal subunit RNA gene [Roe et al. (1985) J. Biol. Chem. 260, 9759-9774] are reported. We found an additional fragment of 142 nucleotides and describe 25 nucleotide differences scattered in the gene. The nucleotide sequence of the X. laevis mitochondrial 12 S rRNA gene presents 80% homology with that of the same gene of bovine mitochondrion. We propose a new secondary structure for the product of the X. laevis gene. Contrary to the finding of Roe et al., we observed the same general organization of stems and loops as for the human mitochondrial 12 S rRNA gene product. On the other hand, the structural homology observed between the mitochondrial and cytoplasmic small subunit rRNAs of X. laevis appears much lower. These results strongly suggest that animal vertebrate mitochondrial DNAs have followed the same evolutionary pathway

Haptic guidance improves the visuo-manual tracking of trajectories

BACKGROUND: Learning to perform new movements is usually achieved by following visual demonstrations. Haptic guidance by a force feedback device is a recent and original technology which provides additional proprioceptive cues during visuo-motor learning tasks. The effects of two types of haptic guidances-control in position (HGP) or in force (HGF)-on visuo-manual tracking ("following") of trajectories are still under debate. METHODOLOGY/PRINCIPALS FINDINGS: Three training techniques of haptic guidance (HGP, HGF or control condition, NHG, without haptic guidance) were evaluated in two experiments. Movements produced by adults were assessed in terms of shapes (dynamic time warping) and kinematics criteria (number of velocity peaks and mean velocity) before and after the training sessions. CONCLUSION/SIGNIFICANCE: These results show that the addition of haptic information, probably encoded in force coordinates, play a crucial role on the visuo-manual tracking of new trajectories

Effect of ship locking on sediment oxygen uptake in impounded rivers

In the majority of large river systems, flow is regulated and/or otherwise affected by operational and management activities, such as ship locking. The effect of lock operation on sediment-water oxygen fluxes was studied within a 12.9 km long impoundment at the Saar River (Germany) using eddy-correlation flux measurements. The continuous observations cover a time period of nearly 5 days and 39 individual locking events. Ship locking is associated with the generation of surges propagating back and forth through the impoundment which causes strong variations of near-bed current velocity and turbulence. These wave-induced flow variations cause variations in sediment-water oxygen fluxes. While the mean flux during time periods without lock operation was 0.5 6 0.1 g m�2 d�1, it increased by about a factor of 2 to 1.0 6 0.5 g m�2 d�1 within time periods with ship locking. Following the daily schedule of lock operations, fluxes are predominantly enhanced during daytime and follow a pronounced diurnal rhythm. The driving force for the increased flux is the enhancement of diffusive transport across the sediment-water interface by bottom-boundary layer turbulence and perhaps resuspension. Additional means by which the oxygen budget of the impoundment is affected by lock-induced flow variations are discussed

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n  =  2 RMP maintaining good confinement HH(98,y2)≈0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.Peer reviewe

Do borrão às aguadas: os engenheiros militares e a representação da Capitania de São Paulo

A análise do papel dos engenheiros militares perpassa as discussões sobre regiões específicas, mesmo quando eles, aparentemente, estão ausentes delas. Sua presença ou ausência sempre foi sinônimo de interesse e de projeto colonizador mais ou menos dirigido. Este ensaio tem como objeto de estudo a cartografia dos engenheiros militares atuantes na Capitania de São Paulo, território comumente visto como economicamente periférico e mais autônomo face aos desígnios da Coroa portuguesa. Com foco no corpus cartográfico de alguns profissionais que aqui atuaram, trata indiretamente da multifacetada atuação desses engenheiros, bem como do processo de feitura das cartas geográficas, corográficas e topográficas, do borrão às aguadas. Investigar a cartografia de alguns desses profissionais permite não apenas explorar a riqueza de suas biografias, como, também, acompanhar o processo de produção técnica dos mapas e os desígnios políticos envolvidos no devassamento e representação das terras descobertas no Novo Mundo.Analyzing the role of military engineers means venturing into discussions about specific regions, even those from which they are apparently absent. Their presence or absence has always been synonymous with interest and a more or less directed colonization project. This essay examines the maps produced by the military engineers working in the Captaincy of São Paulo, a territory often looked upon as one of little economic import and a rather autonomous area in light of the plans of the Portuguese Crown. By focusing on the cartographic corpus bequeathed by certain professionals serving in this region, we deal indirectly with the multifaceted role of these engineers as well as with the process of making geographic, chorographic and topographic charts - all the way from the sketch to watercolored maps. Perusing the charts constructed by some of these professionals enabled us not only to delve into the rich details of their biographies but also to observe the technical mapmaking process and to unravel the political designs behind the exploration and representation of the lands discovered in the New World

Decifrando mapas:sobre o conceito de "território" e suas vinculações com a cartografia

This essay studies the cartographic documentation left by military engineers in Portugal, during the 18th Century. The technical dimension of map making is analysed, focusing on the instruments and the methods employed both in field surveys and in subsequent graphic representations. From the point of view of Material Culture, maps are understood as cultural artefacts, therefore historical artefacts; in this sense, the particularities of cartographic language reveal the world conceptions particular to each period. This article proposes a methodology of morphological analysis of the cartographic language, deconstructing the several strata in the organisation of this kind of visual representation. In order to do so, a vast array of heterogeneous correlate documents is mobilised, such as practical geometry, drawing and architecture treatises, contemporary to the period studied.O ensaio versa sobre a documentação cartográfica legada pelos engenheiros militares, em Portugal, no século XVIII. Analisa a dimensão técnica da produção de mapas, focalizando os instrumentos e os métodos empregados nos levantamentos de campo e no desenho de gabinete. Do ponto de vista da cultura material, os mapas são interpretados como artefatos culturais e, portanto, históricos; dessa forma, as particularidades da linguagem cartográfica revelam as concepções de mundo, o estado do conhecimento científico, as convenções e os códigos de representação próprios de cada período. Propõe uma metodologia de análise morfológica da linguagem cartográfica, desconstruindo os diversos estratos da tessitura desse tipo de representação visual. Para tanto, mobiliza um vasto campo de documentos correlatos, heterogêneos, tais como tratados de geometria prática, desenho e arquitetura, contemporâneos ao objeto de estudo