Arrestment of carbohydrate metabolism during anaerobic dormancy and aerobic acidosis inArtemia embryos: determination of pH-sensitive control points

1986 ◽  
Vol 156 (4) ◽  
pp. 451-459 ◽  
Author(s):  
John F. Carpenter ◽  
Steven C. Hand
1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.


1959 ◽  
Vol 37 (7) ◽  
pp. 901-910 ◽  
Author(s):  
A. Hutchinson ◽  
C. D. Taper ◽  
G. H. N. Towers

The phloridzin content of dormant terminal twigs of Malus rootstock clones was not related to the vigor imparted to the scions. In young seedling trees it varied with the nutritional status of the plant; an acute deficiency of nitrogen, sulphur, or calcium resulted in a significant increase in phloridzin accumulation. Phloridzin is synthesized readily in the leaf from C14O2 in the light and appears to be stable once formed. Phenylalanine-C14 and tyrosine-C14, when fed to leaf disks, are incorporated into the C6–C3 moiety of phloridzin which includes ring B. Tyrosine is not as effective as phenylalanine. Acetate-C14 is incorporated into ring A. Phloroglucinol is not involved in the synthesis of phloridzin. A method for the quantitative determination of phloridzin is described, also a semimicro method for its alkaline hydrolysis. The large amounts of radioactive D-glucitol formed from a wide variety of precursor compounds indicate a central role for it in the carbohydrate metabolism of Malus.


2005 ◽  
Vol 33 (4) ◽  
pp. 737-742 ◽  
Author(s):  
M. Moulin ◽  
A.G. Smith

Plant tetrapyrroles are the most abundant biomolecules on the earth and are cofactors of many apoproteins essential for plant function. The four end-products sirohaem, chlorophyll, haem and phytochromobilin are synthesized by a common branched pathway, which is tightly regulated to ensure a continuous supply to the cognate apoproteins. This may induce strong competition between different branches of the pathway for common substrates. In addition, the intermediates, which are phototoxic, must not be allowed to accumulate in the cell. The major control points are during the synthesis of the initial precursor, ALA (5-aminolaevulinic acid), and at the branch points for the insertion of metal ions into the porphyrin macrocycle. A recent study has also suggested that tetrapyrroles are involved in the communication between the chloroplast and the nucleus, strengthening the necessity for tight regulation. However, intermediates remain difficult to quantify mainly due to their low content and the different properties of the intermediates. In this paper, we summarize the regulation of this pathway and we detail why it is important to have an accurate method for the determination of tetrapyrroles in plants.


Author(s):  
Chien-Hsun Chu ◽  
Kai-Wei Chiang

The early development of mobile mapping system (MMS) was restricted to applications that permitted the determination of the elements of exterior orientation from existing ground control. Mobile mapping refers to a means of collecting geospatial data using mapping sensors that are mounted on a mobile platform. Research works concerning mobile mapping dates back to the late 1980s. This process is mainly driven by the need for highway infrastructure mapping and transportation corridor inventories. In the early nineties, advances in satellite and inertial technology made it possible to think about mobile mapping in a different way. Instead of using ground control points as references for orienting the images in space, the trajectory and attitude of the imager platform could now be determined directly. Cameras, along with navigation and positioning sensors are integrated and mounted on a land vehicle for mapping purposes. Objects of interest can be directly measured and mapped from images that have been georeferenced using navigation and positioning sensors. Direct georeferencing (DG) is the determination of time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning using the Global Navigation Satellite System (GNSS) and inertial navigation using an Inertial Measuring Unit (IMU). Although either technology used along could in principle determine both position and orientation, they are usually integrated in such a way that the IMU is the main orientation sensor, while the GNSS receiver is the main position sensor. However, GNSS signals are obstructed due to limited number of visible satellites in GNSS denied environments such as urban canyon, foliage, tunnel and indoor that cause the GNSS gap or interfered by reflected signals that cause abnormal measurement residuals thus deteriorates the positioning accuracy in GNSS denied environments. This study aims at developing a novel method that uses ground control points to maintain the positioning accuracy of the MMS in GNSS denied environments. At last, this study analyses the performance of proposed method using about 20 check-points through DG process.


Author(s):  
P. Ye. Hryhorovskyi ◽  
V. A. Basanskyi ◽  
Yu. V. Kroshka ◽  
I. V. Osadcha

To predict the dynamics of landslide processes, it is necessary to have information about the change of factors of man-made and natural influences over time. An important source of such information is instrumental and geodetic monitoring. To choose an effective method and systems of instrumental monitoring, it is necessary to compare the main organizational and technological indicators (duration and labor costs) of variants of such systems. The calculation of the duration and labor costs for measuring work when observing the deformations of landslides can be determined on the basis of existing norms of uniform time norms and prices for survey work or using the trace element method of normalization of labor processes.The article presents a brief analysis of the relationship between the norm of duration of measuring works, on the example of geometric leveling of class II to determine the deposition of deformation control points (marks), determined by the current uniform norms of time and rates for survey work and the duration of the same labor process. microelement method of rationing. The list and structure of works on performance of leveling of the II class, as set of elementary labor actions (operations) so isolated and outlined that the further division is inexpedient is defined. The microelements of the labor process are singled out and their normative duration in hours is determined, obtained on the basis of the experience of operation of measuring instruments during the performance of works on determination of deposition of deformation marks.The coefficient of interrelation between the existing current norms and the actual duration of the labor process, determined by the microelement rationing method for works on geometric leveling of the II class, which allows to distinguish the actual duration of the labor process as a norm, without taking into account the duration of preparatory on holiday. The inconsistency of the current standards of measurement work with modern methods of work, equipment, features of instrumental monitoring, monitoring in compacted buildings and other types of work creates the need to determine the elements of the relationship between existing standards and the actual duration of work in modern construction.


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