1000 resultados para Acoela indeterminata, width


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This paper reports that the transmission of O6+ ions with energy of 150keV through capillaries in an uncoated Al2O3 membrane was measured, and agreements with previously reported results in general angular distribution of the transmitted ions and the transmission fractions as a function of the tilt angle well fitted to Gaussian-like functions were observed. Due to using an uncoated capillary membrane, our c is larger than that using a gold-coated one with a smaller value of E-p/q, which suggests a larger equilibrium charge Q(infinity) in our experiment. The observed special width variation with time and a larger width than that using a smaller E-p/q were qualitatively explained by using mean-field classical transport theory based on a classical-trajectory Monte Carlo simulation.

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In Laminaria japonica Aresch breeding practice, two quantitative traits, frond length (FL) and frond width (FW), are the most important phenotypic selection index. In order to increase the breeding efficiency by integrating phenotypic selection and marker-assisted selection, the first set of QTL controlling the two traits were determined in F-2 family using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Two prominent L. japonicas inbred lines, one with "broad and thin blade" characteristics and another with "long and narrow blade" characteristics, were applied in the hybridization to yield the F-2 mapping population with 92 individuals. A total of 287 AFLP markers and 11 SSR markers were used to construct a L. japonica genetic map. The yielded map was consisted of 28 linkage groups (LG) named LG1 to LG28, spanning 1,811.1 cM with an average interval of 6.7 cM and covering the 82.8% of the estimated genome 2,186.7 cM. While three genome-wide significant QTL were detected on LG1 (two QTL) and LG4 for "FL," explaining in total 42.36% of the phenotypic variance, two QTL were identified on LG3 and LG5 for the trait "FW," accounting for the total of 36.39% of the phenotypic variance. The gene action of these QTL was additive and partially dominant. The yielded linkage map and the detected QTL can provide a tool for further genetic analysis of two traits and be potential for maker-assisted selection in L. japonica breeding.

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Using a reflector insert, the original HM-3 lithotripter field at 20 kV was altered significantly with the peak positive pressure (p(+)) in the focal plane increased from 49 to 87 MPa while the -6 dB focal width decreased concomitantly from 11 to 4 mm. Using the original reflector, p(+) of 33 MPa with a -6 dB focal width of 18 mm were measured in a pre-focal plane 15-mm proximal to the lithotripter focus. However, the acoustic pulse energy delivered to a 28-mm diameter area around the lithotripter axis was comparable ( approximately 120 mJ). For all three exposure conditions, similar stone comminution ( approximately 70%) was produced in a mesh holder of 15 mm after 250 shocks. In contrast, stone comminution produced by the modified reflector either in a 15-mm finger cot (45%) or in a 30-mm membrane holder (14%) was significantly reduced from the corresponding values (56% and 26%) produced by the original reflector (no statistically significant differences were observed between the focal and pre-focal planes). These observations suggest that a low-pressure/broad focal width lithotripter field will produce better stone comminution than its counterpart with high-pressure/narrow focal width under clinically relevant in vitro comminution conditions.

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Neocalanus plumchrus/flemingeri copepods make up a large proportion of spring mesozooplankton biomass and are a valuable nutritional source for many higher trophic levels. Copepodites through to sub-adult stage are present in surface waters for a relatively short period of time each spring, and the date of maximum biomass has been calculated as the date when 50% of the population were at the sub-adult, CV stage. This index allows quite a precise date to be calculated from relatively infrequent sampling and interannual comparisons between 1957 and 2004 have demonstrated that the timing of peak abundance is significantly advanced in warmer years. However, recent data from the Continuous Plankton Recorder survey, which samples the surface NE Pacific more frequently during spring, has found that maximum numbers of CV copepodites occur after the 50% point is reached so that maximum biomass occurs some weeks later than predicted by this index (although comparisons between years show that the magnitude of the timing shift is similar). Comparisons with depth-stratified profiles from the BIONESS show that this is not just due to single-depth near-surface sampling by the CPR. We speculate on the cause of this change which could be related to the width of the cohort (which appears to now be narrower, at least in warm years) or the length of time that the CV stage needs to spend in the surface accumulating lipid before beginning diapause. A narrower cohort has implications for predators who will have less time to take advantage of this food source.

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In order to broaden the information about the organisation of the nervous system in taxon Acoela, an immunocytochemical study of an undetermined Acoela from Cape Kartesh, Faerlea glomerata, Avagina incola and Paraphanostoma crassum has been performed. Antibodies to 5-HT and the native flatworm neuropeptide GYIRFamide were used. As in earlier studies, the pattern of 5-HT immunoreactivity revealed an anterior structure composed mainly of commissures, a so-called commissural brain. Three types of brain shapes were observed. No regular orthogon was visualised. GYIRFamide immunoreactive cell clusters were observed peripherally to the 5-HT immunoreactive commissural brain. Staining with anti-GYIRFamide revealed more nerve processes than did staining with anti-FMRFamide. As no synapomorphies were found in the organisation of the nervous system of the Acoela and that of the Platyhelminthes, the results support the view that the Acoela is not a member of the Platyhelminthes. (C) 2001 Harcourt Publishers Ltd.

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According to recent molecular studies, the Acoela are the earliest extant bilaterian group. Their nervous system displays a striking variety of patterns. The aim of the present investigation was to study the variability of the nervous system in a monophyletic group of the Acoela. Six species of Paraphanostoma were chosen for the study. Using immunocytochemical methods and confocal scanning laser microscopy, the immunoreactive patterns of serotonin (5-HT) and the neuropeptide GYIRFamide were described in detail. The study has demonstrated that the brains in Paraphanostoma species, although diverse in detail, still follow the same general pattern. 18S rDNA sequences were used to generate a hypothesis of the phylogeny within the group. Characters of the nervous system revealed in this study were coded and analysed together with 18S rDNA data. Several synapomorphies in the nervous system characters were identified. However, numerous parallelisms in the nervous system evolution have occurred. Data obtained demonstrate that the genus Paraphanostoma is closely related to Childia and should belong to the same family, Childiidae.

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This paper describes an investigation of various shroud bleed slot configurations of a centrifugal compressor using CFD with a manual multi-block structured grid generation method. The compressor under investigation is used in a turbocharger application for a heavy duty diesel engine of approximately 400 hp. The baseline numerical model has been developed and validated against experimental performance measurements. The influence of the bleed slot flow field on a range of operating conditions between surge and choke has been analysed in detail.
The impact of the returning bleed flow on the incidence at the impeller blade leading edge due to its mixing with the main through-flow has also been studied. From the baseline geometry, a number of modifications to the bleed slot width have been proposed, and a detailed comparison of the flow characteristics performed. The impact of slot variations on the inlet incidence angle has been investigated, highlighting the improvement in surge and choked flow capability. Along with this, the influence of the bleed slot on stabilising the blade passage flow by the suction of the tip and over-tip vortex flow by the slot has been considered near surge.