Position Of Tag Research Articles

Positional distribution of CLA in TAG of lamb tissues.

The content and positional distribution of CLA in TAG fractions of lamb tissues was examined with either preformed CLA or the linoleic acid precursor of CLA in the diet as experimental treatments. The CLA content of phospholipid (PL) from these tissues was also examined. Thirteen lambs were randomized to the following dietary treatments: (i) control diet (no supplement); (ii) CLA supplementation (0.33 g d(-1) for 21 d prior to weaning) to milk-replacer of pre-ruminating lambs, or (iii) feeding linoleic acid-rich oil (6% safflower oil on a dry matter basis) to weaned ruminating lambs. At slaughter, tissue samples were procured from diaphragm, rib muscle, and subcutaneous (SC) adipose tissue. Safflower oil supplementation in the diet resulted in an increase in CLA content of the TAG from diaphragm, rib muscle, and SC adipose tissue by about threefold (P< 0.05) on a mol% basis. CLA was localized to the sn-1/3 positions of TAG. Animals that received pre-formed CLA, however, had increased proportions of CLA at the sn-2 position of TAG from SC adipose tissue, suggesting that there were tissue-specific dietary effects and possible age-related effects on the mode of FA incorporation into TAG. Safflower oil supplementation in the diet had no effect on the CLA content of PL from diaphragm, rib muscle, and SC adipose tissue, suggesting that CLA was preferentially incorporated into the TAG of these tissues.

Effects of phase encode order and segment interpolation methods on the quality and accuracy of myocardial tags during assessment of left ventricular contraction.

Tissue tagging can be implemented during cardiovascular magnetic resonance imaging exams to assist with the quantification of left ventriculargeometry, volume and ejection fraction, endocardial thickening and relaxation, and myocardial stress-strain relationships. During tagged cine gradient echo image acquisitions of left ventricular wall motion, rows of k-space data can be acquired with various phase-encoding orders, and the reconstruction of supplemental images can be accomplished using a variety of interpolation techniques. In this study, we investigated the utility of various phase order and segment interpolation methods for determining accurate tag displacement trajectories. Center-out phase order image acquisition with reconstruction using linear interpolation provided the highest tag position and displacement accuracy. Therefore, it is recommended that myocardial tagging exams be acquired with center-out phase encode order and reconstructed using linear segment interpolation when used for performing quantitative analysis of cardiovascular structure and function.

Genetic engineering of the Trichoderma reesei endoglucanase I (Cel7B) for enhanced partitioning in aqueous two-phase systems containing thermoseparating ethylene oxide–propylene oxide copolymers

Endoglucanases (endo-1,4-β- d-glucan-4-glucanohydrolase, EC 3.2.1.4) are industrially important enzymes. In this study endoglucanase I (EGI or Cel7B) of the filamentous fungi Trichoderma reesei has been genetically engineered to investigate the influence of tryptophan rich peptide extensions (tags) on partitioning in an aqueous two-phase model system. EGI is a two-domain enzyme and is composed of a N-terminal catalytic domain and a C-terminal cellulose binding domain, separated by a linker. The aim was to find an optimal tag and fusion position, which further could be utilised for large scale extractions. Peptide tags of different length and composition were attached at various localisations of EGI. The fusion proteins were expressed from T. reesei with the use of the gpdA promoter from Aspergillus nidulans. Variations in secreted levels between the engineered proteins were obtained. The partitioning of EGI in an aqueous two-phase system composed of a thermoseparating ethylene oxide–propylene oxide random copolymer (EO 50PO 50) and dextran, could be significantly improved by relatively minor genetic engineering. The (Trp-Pro) 4 tag added after a short stretch of the linker, containing five proline residues, gave in the highest partition coefficient of 12.8. The yield in the top phase was 94%. The specific activity was 83% of the specific activity of unmodified EGI on soluble substrate. The efficiency of a tag fused to a protein is shown by the tag efficiency factor (TEF). A hypothetical TEF of 1.0 would indicate full tag exposure and optimal contribution to the protein partitioning by the fused tag. The location of the fusion point after the sequence of five proline residues in the linker of EGI is the most beneficial in two-phase separation. The highest TEF (0.97) was obtained with the (Trp-Pro) 2 tag at this position, indicating full exposure and intactness of the tag. However, the peptide tag composed of (Trp-Pro) 4 improved the partition properties the most but had lower TEF in comparison to (Trp-Pro) 2.

Tag surface reconstruction and tracking of myocardial beads from SPAMM-MRI with parametric B-spline surfaces.

Magnetic resonance imaging (MRI) is unique in its ability to noninvasively and selectively alter tissue magnetization, and create tag planes intersecting image slices. The resulting grid of signal voids allows for tracking deformations of tissues in otherwise homogeneous-signal myocardial regions. In this paper, we propose a specific spatial modulation of magnetization (SPAMM) imaging protocol together with efficient techniques for measurement of three-dimensional (3-D) motion of material points of the human heart (referred to as myocardial beads) from images collected with the SPAMM method. The techniques make use of tagged images in orthogonal views by explicitly reconstructing 3-D B-spline surface representation of tag planes (tag planes in two orthogonal orientations intersecting the short-axis (SA) image slices and tag planes in an orientation orthogonal to the short-axis tag planes intersecting long-axis (LA) image slices). The developed methods allow for viewing deformations of 3-D tag surfaces, spatial correspondence of long-axis and short-axis image slice and tag positions, as well as nonrigid movement of myocardial beads as a function of time.

Improving contrast and tracking of tags in cardiac magnetic resonance images.

Cardiac tagging permits non-invasive study of myocardial motion with high accuracy. Unfortunately, tagging contrast is impaired at later heart phases due to longitudinal relaxation. Histogram modification is presented as a method for improving contrast in later, faded images of a tagging series by altering these images such that their intensity histograms approximate the shape of the first, unfaded image of the series. This technique greatly improves the contrast and facilitates automatic detection of tags. Furthermore, a method is described for automatically tracking tag positions in short-axis images of the left ventricle modulated with a tagging grid. The method differs from previously reported methods in that, in one single filtering process in the Fourier domain, both the grid crossings as well as the grid centers are detected, and thus increased sampling resolution is obtained. The method was validated by applying a mathematical model of left ventricular motion to tagged images of the thigh muscle. The average discrepancy between theoretically predicted and automatically detected tag positions was 0.04 +/- 0.17 mm (mean +/- SD).

Coded Wire Tag Placement Affects Homing Ability of Pink Salmon

Abstract Coded wire tags (CWTs) are routinely injected into the snouts of Pacific salmon Oncorhynchus spp. as fry to estimate contributions of tagged populations to spawning escapements and near-shore fisheries and to assess straying. Because not all fish are tagged, tag recoveries are extrapolated to include contributions of nontagged fish released at the same time and location. A key assumption in the extrapolations is that CWTs do not affect homing ability and therefore migratory pathways. We studied tag position within the heads of homing and straying adult pink salmon O. gorbuscha returning to Prince William Sound, Alaska, to test the hypothesis that poor tag position induces straying. Heads from straying and homing tagged adults were recovered in 1992 and 1994 and X-rayed. Tag locations were categorized into critical and noncritical areas, based on tag position relative to olfactory organs and nerves. In 1992, the 37 analyzed pink salmon that strayed were more likely to have tags in critical positio...

Positional distribution of Δ5‐olefinic acids in triacylglycerols from conifer seed oils: General and specific enrichment in the sn‐3 position

AbstractTriacylglycerols (TAG) were purified from the storage lipids extracted from the seeds of several conifer species (Taxus baccata, Larix decidua, Sciadopytis verticillata, and Juniperus communis), each species belonging to one of the four families Taxaceae, Pinaceae, Taxodiaceae, and Cupressaceae, respectively. Each species was characterized by a high content of 5,9‐18:2, 5,9,12‐18:3, 5,11,14‐20:3, or 5,11,14,17‐20:4 acids, respectively. TAG were partially deacylated with ethylmagnesium bromide, and the resulting 1,2‐, 2,3‐diacylglycerols (DAG), and 2‐monoacylglycerols (MAG) were purified by thin‐layer chromatography. 1,2‐ and 2,3‐DAG were further fractionated by chiral column high‐performance liquid chromatography of the 3,5‐dinitrophenylurethane derivatives. Alternately, TAG were subjected to porcine pancreatic lipase, and the resulting 2‐MAG were purified for further analysis. Gas‐liquid chromatography of fatty acid methyl esters prepared from the separated DAG and MAG, coupled with appropriate calculations, indicated that the Δ5‐olefinic acids, irrespective of the species, chainlengths and number of ethylenic bonds, were considerably enriched in the sn‐3 position of TAG where they accounted for ca. 35 to 74 mole% of fatty acids esterified to this position (depending on the initial level of total Δ5‐olefinic acids in TAG), which corresponded to 79–94% of Δ5‐olefinic acids esterified to the three positions. On the other hand, Δ5‐olefinic acids were less than 10% in the sn‐2 position and less than 6% in the sn‐1 position of TAG. This specific enrichment of Δ5‐olefinic acids in the sn‐3 position thus appears to be a general characteristic of conifer seed TAG. These results were extended to TAG from the seeds of two pine species (Pinus koraiensis and P. pinaster) that are rich in Δ5‐olefinic acids and available commercially on a ton‐scale.

Optimization of tag thickness for measuring position with magnetic resonance imaging

Using magnetic resonance (MR) tagging, it is possible to track tissue motion by accurate detection of tag line positions. The authors show that with a least squares estimation algorithm, it is possible to define the position of the tag lines with a precision on the order of a tenth of a pixel. They calculate the Cramer-Rao bound for the tag position estimation error as a function of the tag thickness, the shape of the tag profile and line spread function of the MR imaging system. The tag thickness that minimizes tag position estimation error is between 0.8 to 1.5 pixels depending on the shape of the tag and the line spread function. In addition, tag position estimation error is inversely proportional to contrast-to-noise ratio between the tag and the background tissue. The theoretical results obtained in this study were verified by experiments performed on a whole-body 1.5 T MR imager and Monte-Carlo simulation studies.

Natural growth bands and growth variability in the sea urchin Echinus esculentus: results from tetracycline tagging

Growth of the European edible sea urchin Echinus esculentus L. was studied in a population held for 2 yr in cages on the sea bed, after labelling with the skeletal growth marker tetracycline. The final position of the tetracycline tag on the genital plates agreed with an annual periodicity in natural growth zones; two such growth zones appeared beyond the position of the tag on the ground surface of the plate as light-reflecting bands separated by narrow dark lines in the middle layer. Individual and group (pooled data) growth parameters were estimated from the growth increment shown in the genital plate, whose lateral growth displayed a linear relationship to the diameter of the urchin test within the size range of these measurements. Von Bertalanffy growth parameters (asymptotic size and growth-rate function K) fitted to the growth increment on each individual were highly significantly correlated to those fitted to the natural growth lines, assuming an annual periodicity. The inferred growth pattern agrees well with conclusions based on H. B. Moore's growth-band data. The caged urchins can be assumed to have experienced exactly similar conditions, yet the growth curves fitted to individuals showed considerable variability. The good agreement between estimated growth function parameters of individuals obtained by the two methods indicate that this reflects real variability in growth between individuals that probably is genetically rather than environmentally determined. The growth of E. esculentus, and the adaptational significance of high growth variability in the population is briefly discussed.

Wh-questions with guesses in tag position

Wh-questions with guesses in tag position

Skeletal growth zones as age-markers in the sea urchinPsammechinus miliaris

Growth of the inshore sea urchinPsammechinus miliaris (Gmelin) was studied in Loch Creran, western Scotland, using the skeletal growth-marker tetracycline in order to test the validity of natural growth-banding in the coronal test plates as annual age-markers. In order to test whether tetracycline affected the growth ofP. miliaris, an injected and a control group of urchins were held in identical conditions in running sea water aquaria for 21 mo from 1989 to 1991 and measured periodically. A small but significant difference in mean size of injected compared to controls was recorded at 12 mo, but none during subsequent measurements. Size measurements during the trial were consistent with an annual growth cycle, with a maximum in spring and slowing or cessation of growth during autumn/winter. Tetracycline-labelled juveniles were recovered up to 18 mo after initial tagging in mark/recapture experiments undertaken from 1987 to 1989 at two intertidal marked quadrats in Loch Creran. Large numbers ofP. miliaris were also marked with tetracycline and held for 1 yr at 10 m depth in seabed cages in Loch Creran during 1988–1990. All of the intertidal recoveries, and about 69% of the caged specimens that had been successfully labelled, showed a consistent relationship between the position of the tetracycline tag and the pattern of natural growth zones. The remainder were mostly large, slow-growing urchins with the tag positioned near the plate margin. In these the outer growth bands were closely spaced and, particularly if major growth bands seemed to be broken up into double or multiple lines, the major bands were impossible to resolve at the margin. The results support the assumption that in wild populations the dark bands visible with reflected light (translucent in transmitted light) after charring the plate are formed when skeletal growth has stopped or slowed in winter. These lie between wider, lighter coloured (opaque in transmitted light) zones of active plate growth in spring/summer. The dark band formed beyond the tag usually was made up of several closely spaced fine lines, or sometimes of two closely spaced dark bands. The wide growth zones beyond the tag, like those formed previously, usually were broken by fine, dark lines that may represent brief discontinuities in growth. From tagging, the double dark bands can be related to growth over one year; but such anomalous bands, along with the general presence of fine, dark lines interrupting the growth zones, make it difficult reliably to estimate age from the closely spaced peripheral banding on older, slow-growing urchins.

Noninvasive quantification of left ventricular rotational deformation in normal humans using magnetic resonance imaging myocardial tagging.

It has been postulated that rotation of the left ventricular apex with respect to the base is a component of normal systolic function in humans, but it has been difficult to measure it noninvasively. Tagging is a new magnetic resonance imaging technique that labels specific areas of myocardium by selective radio-frequency excitation of narrow planes orthogonal to the imaging plane before acquiring an image. Tags appear as black lines and persist in myocardium for 400-500 msec and, if applied at end diastole, will move with the myocardium through systole. Tagging was used to noninvasively quantify left ventricular torsion and circumferential-longitudinal shear (shearCL) in humans. Eight normal volunteers, aged 24-38 years, were imaged in a 0.38-T iron-core resistive magnet. Five short-axis left ventricular images, positioned to encompass the entire left ventricle (LV), were obtained separately at end systole. Four equiangular radial tags had been applied at end diastole, intersecting the myocardium at eight locations. We calculated the difference in angular displacement of each epicardial and endocardial tag point (a tag point being where the tag crossed the epicardium or endocardium) at end systole from the systolic position of the corresponding tag point on the basal plane. This value was called the torsion angle. From this, shearCL, the angle inscribed on the epicardial or endocardial surface between the systolic tag position, the corresponding basal tag position, and its projection onto the slice of interest could be calculated at 32 points in the left ventricular wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Navigation and Anti-collision Sensor for Transport Robots

A sensor system to detect and locate a tag for an automatic transport vehicle, e.g., a forklifter, is described. It consists of a laser scanner that scans a tag. Due to an individual coding of each tag, a typical pulse train can be derived from the reflected light. This pulse train contains information about the tag identity and the tag position relative to the scanner. Data processing is done by a microcomputer within the scanner system, which transfers the data to the control system of the forklifter. Thus, the basis is given for a real-time computation of an optimized driving strategy. An additional laser scanner detects even extremely faintly reflecting obstacles in a well-defined range in front of the vehicle and prevents collisions with persons and objects in the working area of the forklifter.

Distribution and fate of I-131-labeled components of the fibrinolysin system.

The distribution, metabolism, and excretion of intravenously administered I131-labeled components of the fibrinolysin system were studied in dogs. lodination of plasmin tended to decrease slightly its in vitro fibrinolytie activity. Inaetivation appeared to depend on degree of iodination. Todination of strepto-kinase or urokinase did not decrease their plasminogen activator potential. All plasmins and plasminogen, regardless of the position of the iodine tag, adsorbed to preformed clots in the dog. Spontaneously activated human and chloroform-activated bovine plasmin adsorbed to a lesser extent than streptokinase-or urokinase-activated human plasmin. Clots removed from piasmin-treated dogs lysed in vitro within 24 hours. However, streptokinase or urokinase alone, on the basis of radioactivity measurements, did not exhibit any affinity for clots, nor did they cause any clot lysis. Plasma clearance curves revealed the presence of at least two processes in all preparations: a fast one (average half-life four minutes) responsible for the removal of over 60 per cent of the injected radioactivity and a slower process with a biological half-life greater than four hours. Pour hours after the injection of labeled compounds, the thyroid and stomach were the only organs which contained significant percentages of the injected radioactivity. Major excretory routes for the radioactivity were the urinary and biliary systems. Persistence of circulating radioactivity at a time when no free fibrinolytie activity could be determined in the blood was interpreted as complex formation between plasmin and antiplasmin.