scholarly journals Remodeling and Spacing Factor 1

2020 ◽  
Author(s):  
Keyword(s):  
Spacing Factor

scholarly journals RSF1 in cancer: interactions and functions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guiyang Cai ◽  
Qing Yang ◽  
Wei Sun
Keyword(s):  
Optimal Level ◽  
Cell Cycle Checkpoint ◽  
Protein Homeostasis ◽  
Clinical Value ◽  
Cancer Proliferation ◽  
Poor Overall Survival ◽  
Cyclin E1 ◽  
Spacing Factor ◽  
Cycle Checkpoint ◽  
Cancer Types

AbstractRSF1, remodelling and spacing factor 1, is an important interphase centromere protein and is overexpressed in many types of cancers and correlated with poor overall survival. RSF1 has functions mainly in maintaining chromosome stability, facilitating DNA repair, maintaining the protein homeostasis of RSF1 and suppressing the transcription of some oncogenes when RSF1 protein is expressed at an optimal level; however, RSF1 overexpression facilitates drug resistance and cell cycle checkpoint inhibition to prompt cancer proliferation and survival. The RSF1 expression level and gene background are crucial for RSF1 functions, which may explain why RSF1 has different functions in different cancer types. This review summarizes the functional domains of RSF1, the overexpression status of RSF1 and SNF2H in cancer based on the TCGA and GTEX databases, the cancer-related functions of RSF1 in interacting with H2Aub, HDAC1, CENP-A, PLK1, ATM, CENP-S, SNF2H, HBX, BubR1, cyclin E1, CBP and NF-κB and the potential clinical value of RSF1, which will lay a theoretical foundation for the structural biology study of RSF1 and application of RSF1 inhibitors, truncated RSF1 proteins and SNF2H inhibitors in the treatment of RSF1-overexpressing tumours.

scholarly journals Maleic Rosin-based Gemini Surfactant as Air Entraining Agent for Concrete under Low Air Pressure

2021 ◽  
Vol 72 (2) ◽  
pp. 27-37
Author(s):  
Yang Li ◽  
Zhendi Wang ◽  
Ling Wang
Keyword(s):  
Dynamic Modulus ◽  
Gemini Surfactant ◽  
Fresh Concrete ◽  
Concrete Strength ◽  
Air Pressure ◽  
Test Results ◽  
Bubble Liquid ◽  
Air Content ◽  
Spacing Factor ◽  
Plateau Area

The effectiveness of Air entraining agent (AEA) in concrete under low air pressure in the plateau area decreased. A type of new AEA, named MRE was synthesized to increase bubbles` stability in fresh concrete under low air pressure. The performance of MRE solution and concrete with MRE were tested under 60 kPa and 100 kPa compared with commercially gemini AEA (DCC). The test results showed that the foam volume of MRE and DCC solution under 60 kPa was reduced by 3% and 9% than under 100 kPa. The bubble liquid film strength of MRE is 63% higher than that of DCC. For concrete with MRE and DCC under 60 kPa, the air content was 2% and 16% lower, the relative dynamic modulus of concrete reduced by 6% and 15%, and the bubble spacing factor under 60 kPa increased by 17% and 39% respectively compared with that under 100 kPa. MRE can increase the freeze-thaw resistance of concrete under low air pressure without affecting concrete strength and is suitable for high altitude concrete.

Effect of Pumping on Air Characteristics of Conventional Concrete

1996 ◽  
Vol 1532 (1) ◽  
pp. 9-14 ◽  
Author(s):  
M. Lessard ◽  
M. Baalbaki ◽  
P.-C. Aïtcin
Keyword(s):  
Specific Surface ◽  
Freezing And Thawing ◽  
Conventional Concrete ◽  
Freeze Thaw ◽  
Pump Line ◽  
Spacing Factor ◽  
Void System ◽  
The Stability ◽  
Air Void ◽  
Frost Durability

The stability of the air content of concrete during pumping has been the subject of a number of recent investigations. Because increasing volumes of concrete are placed with the aid of pumps and the durability of such concrete to freezing and thawing (ASTM C666) as well as the scaling resistance (ASTM C672) preoccupy engineers, a study concerning the stability of the air-void system of a concrete with 45 to 50 MPa compressive strength was carried out. The slump of the three tested concretes ranged between 85 and 115 mm. Three pumping setups were studied. In the first, the concrete was pumped horizontally; in the second the concrete was pumped upward and then downward. In the third, the vertical setup was used but a reduced section was placed at the end of the pump line, and the concrete was allowed to free fall a short distance. For each pump setup, the concrete was sampled before being placed in the pump and after leaving the pump. The results clearly show that when the concrete is pumped horizontally, the spacing factor (L) and the specific surface of the air-void system are barely altered. On the other hand, after pumping the concrete vertically without a reduced end section, it was impossible to obtain an L less than 230 μm, the maximum spacing factor allowed by Canadian standards (CSA A23.1) to ensure good frost durability. Furthermore, the specific surface of the air bubbles fell to 20 mm−1, which is inferior to the 25-mm−1 value recommended in Canadian standards. By placing a reduced section at the end of the vertical pump line, it was possible to enhance the air-void system but that procedure still fell short of ensuring a system that satisfies the air-void system recommended by Canadian standards to ensure proper frost durability. Although the pumped concrete mixtures did not always satisfy the requirements of CSA A23.1 regarding air-void systems, they satisfied the requirements of ASTM C666 (Procedure A) for resistance to freeze-thaw cycles. Freeze-thaw resistance in the presence of deicing salts was evaluated according to ASTM C672. After 50 frost cycles, all but one concrete exhibited mass losses that were lower than the maximum permissible limit of 0.50 kg/m2 required by BNQ 2621-900, the standard currently enforced in the province of Quebec. Placing a reduced section at the end of the pump line creates a light counterpressure in the descending section of the pump line, which allows the conservation of an acceptable air-void system. Considering the appreciable improvement in the preservation of air-void characteristics when a reduced section was placed at the end of the pump line, it was decided to proceed with further experimental work using four 90-degree elbows placed at the end of the vertically hanging pump line.

scholarly journals The effect of spacing factor on the confinement time of the electrons in a low beta Polywell device

AIP Advances ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 055305
Author(s):  
M. Bagheri ◽  
A. Salar Elahi ◽  
M. K. Salem ◽  
M. Ghoranneviss
Keyword(s):  
Confinement Time ◽  
Spacing Factor

Precision of the air void characteristics measurement by ASTM C 457: results of an interlaboratory test program

1996 ◽  
Vol 23 (5) ◽  
pp. 1118-1128 ◽  
Author(s):  
François Saucier ◽  
Richard Pleau ◽  
Daniel Vézina
Keyword(s):  
Test Method ◽  
Interlaboratory Study ◽  
Hardened Concrete ◽  
Probability Of Error ◽  
Air Content ◽  
Spacing Factor ◽  
Interlaboratory Test ◽  
Void System ◽  
Concrete Production ◽  
Air Void

Since 1993, the Quebec Department of Transportation requires all its concrete suppliers to demonstrate that their concrete satisfies the requirements of the CSA A23.1 standard as regards the maximum spacing factor of the air void system. This new requirement raises questions about the reproducibility of the ASTM C 457 test method. An interlaboratory study was carried out to verify if the variability of the test method is sufficiently low to allow reliable decisions on the acceptance or rejection of in-place hardened concrete. A total of 18 operators from 13 different laboratories microscopically examined the six concrete slabs used for the study. It is concluded that the average reproducibility coefficient of variation is 14.4% for the total air content measurement and 14.2% for the spacing factor measurement. Considering these results, the probability that the measured value of the spacing factor exceeds the mandatory limit of 230 μm on a concrete production containing an air void system with a spacing factor of 170 μm (the target value proposed in the CSA A23.1 M-94 standard) is less than 0.7% (a probability of error of about 1%, 5%, or 10% is typical of most quality control test methods). Key words: concrete, air content, air void measurement, spacing factor, ASTM C 457 standard, interlaboratory study, freeze–thaw durability.

Reply to A. Roy and A. Apparao by author

Geophysics ◽  
1978 ◽  
Vol 43 (6) ◽  
pp. 1276-1276
Author(s):  
L. S. Edwards
Keyword(s):  
Spacing Factor ◽  
Effective Depth ◽  
The Absolute

The calculation of absolute effective depth for any finite, realizable array can be based on the total array length L or on any other spacing factor desired. The burden of the discussion by Roy and Apparao is that the distance a between the active electrodes is the natural spacing factor for the 2‐pole array. I agree entirely with this, as evidenced by my statement that “the absolute effective depth is almost directly proportional to a”, and by my inclusion of [Formula: see text] coefficients in the first column of Table 2. I would consider the factors of this column to be the natural units for depth calculations for all arrays (except for the Schlumberger and gradient arrays, where L or the conventional L/2 is more suitable).

Experiments on the spacing of sugar beet: I. Results based on plot yields

1939 ◽  
Vol 29 (1) ◽  
pp. 48-57 ◽  
Author(s):  
F. H. Garner ◽  
H. G. Sanders
Keyword(s):  
Sugar Beet ◽  
Compensatory Growth ◽  
Correlation Coefficients ◽  
General Rule ◽  
The West ◽  
Spacing Factor ◽  
West Midlands ◽  
Series Of Experiments ◽  
Effect On Yield ◽  
The Relationship

Since sugar beet was first introduced into this country many experiments have been conducted to determine the effects of spacing on yield: the general advice based on these experiments is that beet should be spaced as closely as working conditions permit. Davies (1931) carried out a series of experiments in the West Midlands, and came to the conclusion that yield was not related to the number of roots per acre, but was affected by their distribution. His work demonstrated that wide row distances could not be compensated by narrow spacing in the row. He found that yield increased as row distance decreased down to 16 in., but that singling distances of 4—10 in. produced no differences in yield of roots: the yield of green leaves, on the other hand, was increased as singling distance decreased, but was unaffected by row distance (Davies & Dudley, 1929). Although Davies' results would be generally accepted as a true expression of the general rule, many isolated spacing experiments fail to conform to them; it is possible that discrepancies in results, that undoubtedly occur, may be due to variations in the “plant” actually obtained in the experiments. Engledow et al. (1928), as a result of counts and weights taken on ordinary farm crops of sugar beet, concluded that uniformity of “plant” was a most important spacing factor affecting yield. In America Brewbaker & Deming (1935) have found yield to be related to percentage stand (correlation coefficients varying from +0·35 to +0·70), the regression between the two variables being approximately linear over the range studied. They also found that uniformity of “plant” was more important than spacing distances, either between or in the rows. Their work showed that single gaps had little effect on yield, because neighbouring beet compensated for them to the extent of 96·2%; serious loss of yield only occurred, therefore, with adjacent gaps. Pedersen (1933) studied the relationship between percentage of gaps and yield in a large number of Danish experiments with sugar beet and mangolds. In the case of sugar beet he found that the compensatory growth of neighbouring roots amounted to 76% for a single gap, and that the percentage compensation decreased as the size of gap (i.e. number of missing beet) increased. In an earlier paper (Pedersen, 1931) he had shown that under ordinary field conditions the distribution of gaps was approximately random.

scholarly journals Basis of specificity for a conserved and promiscuous chromatin remodeling protein

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Drake A Donovan ◽  
Johnathan G Crandall ◽  
Vi N Truong ◽  
Abigail L Vaaler ◽  
Thomas B Bailey ◽  
...  
Keyword(s):  
Specific Factor ◽  
Spacing Factor ◽  
Genome Wide ◽  
A Genome ◽  
Acidic Residues ◽  
Physical Interactions ◽  
Specific Factors ◽  
Barrier Model ◽  
Eukaryotic Genomes

Eukaryotic genomes are organized dynamically through the repositioning of nucleosomes. Isw2 is an enzyme that has been previously defined as a genome-wide, non-specific nucleosome spacing factor. Here, we show that Isw2 instead acts as an obligately targeted nucleosome remodeler in vivo through physical interactions with sequence-specific factors. We demonstrate that Isw2- recruiting factors use small and previously uncharacterized epitopes, which direct Isw2 activity through highly conserved acidic residues in the Isw2 accessory protein Itc1. This interaction orients Isw2 on target nucleosomes, allowing for precise nucleosome positioning at targeted loci. Finally, we show that these critical acidic residues have been lost in the Drosophila lineage, potentially explaining the inconsistently characterized function of Isw2-like proteins. Altogether, these data suggest an 'interacting barrier model' where Isw2 interacts with a sequence-specific factor to accurately and reproducibly position a single, targeted nucleosome to define the precise border of phased chromatin arrays.

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