Rehabilitation of field tunnel erosion using techniques developed for construction with dispersive soils

Soil Research ◽  
2007 ◽  
Vol 45 (4) ◽  
pp. 280 ◽  
Author(s):  
M. A. Hardie ◽  
W. E. Cotching ◽  
P. R. Zund
Keyword(s):  
Optical Fibre ◽  
Soil Analysis ◽  
Long Term Stability ◽  
Site Investigations ◽  
Construction Techniques ◽  
A Site ◽  
Dispersive Soils ◽  
Tunnel System ◽  
Surface And Subsurface Flow

Past repairs of field tunnel erosion using mechanical treatments (deep ripping, contour furrowing, contour ripping, etc.) and reestablishment of perennial vegetation have often failed, resulting in further tunnelling. Techniques to prevent ‘piping’ (tunnel erosion) in earth dams constructed using sodic clays have not been used in the repair of field tunnel erosion; however, these techniques have the potential to reduce recurrent failure. Installation of an optical fibre cable in a Grey Sodosol and Grey Dermosol at a site near Dunalley, Tasmania, in November 2001, resulted in the formation of a 380-m-long tunnel erosion system. Detailed site investigations and soil analysis in 2004 indicated that the tunnel erosion resulted from the consequences of inadequate compaction during the installation of the optical fibre cable, and secondary processes such as capture of surface and subsurface flow, dispersion of sodic clays, and translocation of dispersed clay platelets through the poorly compacted fill. Repair works consisted of excavating the entire length of the tunnel system, chemical amelioration with gypsum, compaction of repacked fill to reduce internal porosity, and installation of sand blocks to capture and remove water moving along the reinstalled cable. Inspections conducted 2 years after completion of the repair works indicated the site to be stable; however, it is acknowledged that this is too short an interval to adequately assess the long-term stability of repair works and techniques employed at the site. Due to the costs associated with the application of dam construction techniques, their use for the repair of field tunnel erosion is likely to only be justified where continued erosion poses a risk of damage to high value infrastructure.

Spontaneous reactivation of a site-specifically placed transgene independent of copy number or DNA methylation

2019 ◽  
Vol 71 (4) ◽  
pp. 1574-1584
Author(s):  
Junjie Wei ◽  
Zhicheng Dong ◽  
David W Ow
Keyword(s):  
Chromatin Modification ◽  
Scale Production ◽  
Dna Hypermethylation ◽  
Gfp Expression ◽  
Long Term Stability ◽  
Gfp Reporter ◽  
Gene Reactivation ◽  
Gfp Reporter Gene ◽  
A Site

Abstract As millions of seeds are produced from a breeding line, the long-term stability of transgene expression is vital for commercial-scale production of seeds with transgenic traits. Transgenes can be silenced by epigenetic mechanisms, but reactivation of expression can occur as a result of treatment with chromatin modification inhibitors such as 5-azacytidine, from stress such as heat or UV-B, or in mutants that have acquired a defect in gene silencing. Previously, we targeted a gfp reporter gene into the tobacco (Nicotiana tabacum) genome by site-specific recombination but still found some silenced lines among independent integration events. One such line also had a second random copy and both copies showed DNA hypermethylation. To test whether removing the second copy would reactivate gfp expression, two T1 plants were backcrossed to the wild type. Whereas the silenced status was maintained in the progenies from one backcross, spontaneous partial reactivation of gfp expression was found among progenies from a second backcross. However, this reactivation did not correlate with loss of the second random copy or with a significant change in the pattern or amount of DNA hypermethylation. This finding supports the suggestion that gene reactivation does not necessarily involve loss of DNA homology or methylation.

Long-term stability testing of optical fibre Fabry-Perot temperature sensors

2016 ◽  
Author(s):  
Dimitrios Polyzos ◽  
Mathew Jinesh ◽  
William N. MacPherson ◽  
Robert R. J. Maier
Keyword(s):  
Optical Fibre ◽  
Temperature Sensors ◽  
Stability Testing ◽  
Term Stability ◽  
Long Term Stability ◽  
Fabry Perot

scholarly journals PRIORITY EFFECTS AND ECOLOGICAL RESTORATION

2020 ◽  
Author(s):  
Emanuela W. A. Weidlich ◽  
Cara R Nelson ◽  
John L Maron ◽  
Ragan M. Callaway4 ◽  
Benjamin M. Delory ◽  
...  
Keyword(s):  
Ecological Restoration ◽  
Priority Effects ◽  
Future Research ◽  
Temperate Grasslands ◽  
Long Term Stability ◽  
Lack Of Information ◽  
General Importance ◽  
Restoration Practice ◽  
A Site

Priority effects refer to the order or timing of species arrival, including how species that arrive early to a site either positively or negatively affect establishment, growth, or reproduction of species that arrive later. Despite clear implications of priority effects on ecological restoration, to date there are no reviews of how and where priority effects have been studied and the extent to findings can be applied to restoration practice. Here, we survey the literature on priority effects and a) summarize patterns that are relevant to restoration; b) synthesize information on the mechanisms through which priority effects operate, and on how these mechanisms can be manipulated to achieve particular restoration goals; and c) highlight potential future research needed to improve use of priority effects in restoration. We found that even small delays in arrival time, as opposed to simultaneous arrival of species, can promote differences in subsequent community composition. Even so, there have been very few studies on the long-term stability of these priority effects, and the majority were conducted in temperate grasslands. Given the lack of information for other biomes, the general importance of priority effects, as well as its application to restoration, is unknown. Our findings suggest that creating alternative vegetation states via priority treatments might be a promising avenue to further explore, but that for the concept to be operationalized for restoration practice there is a need for research in the diverse types of ecosystems that are priorities for restoration and that occurs over longer time periods.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

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