Regulation of tetrapyrrole biosynthesis in higher plants

2005 ◽  
Vol 33 (4) ◽  
pp. 737-742 ◽  
Author(s):  
M. Moulin ◽  
A.G. Smith
Keyword(s):  
Higher Plants ◽  
Accurate Method ◽  
Control Points ◽  
Branch Points ◽  
Tetrapyrrole Biosynthesis ◽  
The Earth ◽  
Porphyrin Macrocycle ◽  
End Products ◽  
Strong Competition

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.

scholarly journals Utilization of digital photogrammetry in forestry mapping

2008 ◽  
Vol 53 (No. 5) ◽  
pp. 222-230
Author(s):  
S. Žíhlavník ◽  
F. Chudý ◽  
M. Kardoš
Keyword(s):  
Aerial Images ◽  
Control Points ◽  
Digital Photogrammetry ◽  
Infrared Images ◽  
Qualitative Aspect ◽  
Black And White ◽  
The Earth ◽  
Analogue To Digital ◽  
Product Costs

At present, photogrammetric interpretation of aerial images is a dominant method of forestry mapping. In the last years, transition from analogue to digital photogrammetry has been distinct. Digital photogrammetry enables to achieve workflow effectivity, and so to decrease the final product costs. The objective of the submitted paper was to evaluate the availability of digital photogrammetry for the forestry mapping rationalization. Digital aerotriangulation using the ImageStation SSK system brings more accurate results without requirements for the use of a larger amount of control points. The results also demonstrated the use of colour infrared aerial images, and also black and white aerial images at the scale 1:15,000 for the orthoimage creation in the forestry mapping department. Compared with the black and white aerial images, the colour infrared images have an essentially more interesting content, mainly from the qualitative aspect, which shifts them to use in many forestry disciplines (mostly for determination of the health conditions of forests stands, …), in combination with the remote sensing of the Earth and GIS (Geographic Information Systems).

Determination of Horizontal and Vertical Control Points for Lunar Mapping

1962 ◽  
Vol 14 ◽  
pp. 107-111
Author(s):  
Marvin Q. Marchant
Keyword(s):  
Army Corps ◽  
Control Points ◽  
Army Corps Of Engineers ◽  
The Moon ◽  
Entire Surface ◽  
Vertical Control ◽  
The Earth ◽  
Map Service ◽  
Lunar Mapping

The determination of horizontal and vertical control points has been undertaken by the Army Map Service, U.S. Army Corps of Engineers, to assure that the entire surface of the Moon which is visible from the Earth may be shown in detail and with greater accuracy than that of any existing map.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

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.

HADIS KURAIB DALAM KONSEP RUKYATUL HILAL

1970 ◽  
Vol 13 (2) ◽  
Author(s):  
Muslih Husein
Keyword(s):  
The West ◽  
The Earth ◽  
New Moon ◽  
The Republic

Hisab dan rukyat, hakikatnya, adalah cara untuk mengetahui pergantian bulan. Kajian ini memperlihatkan beberapa temuan. Pertama, korelasi antara hadis Kuraib dan terjadinya perbedaan penetapan awal Ramadan, Syawal, dan Dzul Hijjah di Indonesia. Kementerian Agama Republik Indonesia telah menetapkan bahwa Indonesia secara keseluruhan menjadi satu wilayah hukum (wilayatul hukmi). Kedua, tentang keberhasilan rukyat al-hilal di satu kawasan yang diberlakukan bagi kawasan lain di muka bumi. Perlu diketahui bersama bahwa visibilitas pertama hilal tidak meliputi seluruh muka bumi pada hari yang sama, melainkan membelahnya menjadi dua bagian: (1) bagian sebelah Barat yang dapat melihat hilal dan (2) bagian sebelah Timur yang tidak dapat melihat hilal.Hisab and rukyat is a way to know the turn of the month. This study shows several findings. First is the correlation between Kuraib traditions and differences in the determination of the beginning of Ramadan, Shawwal, and Dhul-Hijjah in Indonesia. Ministry of Religious Affairs of the Republic of Indonesia has stated that Indonesia as a whole into a single jurisdiction (wilayatul hukmi). Second, on the success rukyat alhilal in one area that applied to other regions of earth. Important to know that the first visibility of the new moon does not cover the entire face of the earth on the same day, but splitting it into two parts: (1) part of the West to see the new moon, and (2) part of the East were not able to see the new moon.

Development of an HPLC-UV Method for Quantification of Stattic

2019 ◽  
Vol 15 (6) ◽  
pp. 568-573
Author(s):  
Soheil Sedaghat ◽  
Ommoleila Molavi ◽  
Akram Faridi ◽  
Ali Shayanfar ◽  
Mohammad Reza Rashidi
Keyword(s):  
High Performance ◽  
Accurate Method ◽  
Plasma Samples ◽  
Promising Target ◽  
Relative Standard ◽  
Dimerization Inhibitor ◽  
Oncogenic Protein ◽  
First Time ◽  
Transcription 3

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.

Is it necessary to calculate Young’s modulus in AFM nanoindentation experiments regarding biological samples?

2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou
Keyword(s):  
Young’S Modulus ◽  
Biological Samples ◽  
Young's Modulus ◽  
Reference Sample ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Accurate Solution ◽  
Hertz Model ◽  
Work Done

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

Forecasting the fl ood situation using space images in the city of Tavda Sverdlovsk region

2018 ◽  
Vol 934 (4) ◽  
pp. 46-52
Author(s):  
A.S. Bruskova ◽  
T.I. Levitskaya ◽  
D.M. Haydukova
Keyword(s):  
Water Levels ◽  
Economic Damage ◽  
Geoinformation System ◽  
Space Images ◽  
Geoinformation Systems ◽  
Emergency Situations ◽  
The Earth ◽  
Maximum Water ◽  
The City

Flooding is a dangerous phenomenon, causing emergency situations and causing material damage, capable of damaging health, and even death of people. To reduce the risk and economic damage from flooding, it is necessary to forecast flooding areas. An effective method of forecasting emergency situations due to flooding is the method of remote sensing of the Earth with integration into geoinformation systems. With the help of satellite imagery, a model of flooding was determined based on the example of Tavda, the Sverdlovsk Region. Space images are loaded into the geoinformation system and on their basis a series of thematic layers is created, which contains information about the zones of possible flooding at given water level marks. The determination of the area of flooding is based on the calculation of the availability of maximum water levels at hydrological stations. According to the calculated security data, for each hydrological post, flood zones are constructed by interpolation between pre-calculated flood zones of standard security. The results of the work can be used by the Main Directorate of the Ministry for Emergency Situations of Russia for the Sverdlovsk Region.

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