Effect of cortisol acetate on wool quality in sheep selected for divergent staple strength

2002 ◽  
Vol 53 (2) ◽  
pp. 183 ◽  
Author(s):  
A. C. Schlink ◽  
P. C. Wynn ◽  
J. M. Lea ◽  
J. R. Briegel ◽  
N. R. Adams
Keyword(s):  
Egf Receptor ◽  
Fibre Diameter ◽  
Egf Receptors ◽  
Wool Growth ◽  
Receptor Concentration ◽  
Epidermal Growth ◽  
The Mean ◽  
Staple Strength ◽  
The Impact

These studies utilised cortisol treatment to clarify the role of stress in reducing staple strength (SS). The first study established the impact of the duration of exposure and nutritional status on SS, wool parameters, and epidermal growth factor (EGF) receptors. Sheep (n = 42) were fed at 0.75 or 1.5 times maintenance for 62 days and then administered with 120 mg cortisol acetate/day for 0, 3, or 12 days. SS was reduced significantly (P < 0.05) only in the group fed below maintenance and treated with cortisol for 12 days. In the sheep fed below maintenance, the mean SS was 31.6, 32.7, and 21.5 N/ktex for groups treated for 0, 3, and 12 days of cortisol, respectively. Cortisol administration in these sheep also increased the rate of fibre shedding (P < 0.001) but did not affect their mean fibre diameter. The shed fibres had a finer diameter than those that were not (P < 0.001). The concentration of EGF receptors was not affected by cortisol administration, although submaintenance feeding (P < 0.05) significantly reduced EGF receptor concentration. The second experiment examined whether some sheep were predisposed to reduce SS in response to cortisol. Sheep (n = 42) of low and high prior SS were fed to maintain liveweight for 84 days and then administered with 0 or 120 mg cortisol/day for 12 days. Cortisol administration significantly reduced SS (P < 0.001) and wool growth (P < 0.001), and increased the rate of fibre shedding (P < 0.001) but did not affect fibre diameter. SS history did not affect the response to cortisol administration. We conclude that cortisol reduced SS by increasing fibre shedding, without decreasing fibre diameter. Treatment was only effective in sheep fed at or below maintenance, and required between 3 and 12 days of exposure to cortisol. This is longer than would be observed in many stressful situations in the field.

scholarly journals Role of the Sec61 Translocon in EGF Receptor Trafficking to the Nucleus and Gene Expression

2007 ◽  
Vol 18 (3) ◽  
pp. 1064-1072 ◽  
Author(s):  
Hong-Jun Liao ◽  
Graham Carpenter
Keyword(s):  
Gene Expression ◽  
Endoplasmic Reticulum ◽  
Growth Factor ◽  
Egf Receptor ◽  
Transmembrane Proteins ◽  
Receptor Trafficking ◽  
Cyclin D ◽  
Egf Receptors ◽  
Epidermal Growth

The epidermal growth factor (EGF)-dependent trafficking of the intact EGF receptor to the nucleus and its requirement for growth factor induction of cyclin D and other genes has been reported. Unresolved is the mechanism by which this or other transmembrane proteins are excised from a lipid bilayer before nuclear translocalization. We report that, after the addition of EGF, the cell surface EGF receptor is trafficked to the endoplasmic reticulum (ER) where it associates with Sec61β, a component of the Sec61 translocon, and is retrotranslocated from the ER to the cytoplasm. Abrogation of Sec61β expression prevents EGF-dependent localization of EGF receptors to the nucleus and expression of cyclin D. This indicates that EGF receptors are trafficked from the ER to the nucleus by a novel pathway that involves the Sec61 translocon.

Photoperiodic rhythm of wool growth and its contribution to seasonal wool production by the Merino, Polwarth, and their reciprocal crosses in southern Australia

1994 ◽  
Vol 34 (3) ◽  
pp. 311 ◽  
Author(s):  
LG Butler ◽  
GM Head
Keyword(s):  
Field Data ◽  
Fibre Diameter ◽  
Nutritional Management ◽  
Reciprocal Crosses ◽  
Wool Production ◽  
Growth Difference ◽  
Wool Growth ◽  
Weight Yield ◽  
The Mean ◽  
Staple Strength

Twelve wethers of each of the Merino and Polwarth breeds and their reciprocal crosses were fed at1 of 2 levels in individual pens for 14 months. Periodic clean wool weight, yield, fibre diameter, and the coefficient of variation (CV%) for fibre diameter were measured from midside patches harvested every6 weeks.There was a significant effect of time of wool harvest on clean wool weight per cm2, yield, fibre diameter(all P<0.01), and its CV% (P<0.05). A trough in wool production occurred about August-September and a peak in January. The amplitude of the photoperiodic rhythm of wool growth (difference between maximum and minimum wool growth per cm2 per 42 days as a percentage of the average) was 40%. Yield also displayed a substantial photoperiodic rhythm, but that of fibre diameter was less pronounced. Mean staple strength was 32.3 N/ktex, the mean break occurring at a distance of 60% of the staple length from the tip; there was no effect of genotype or level of feeding. From comparison with published Tasmanian field data, the seasonal wool growth pattern of sheep at pasture appears similar to the photoperiodic rhythm but occurs about a month earlier. It was concluded that the photoperiodic rhythm of wool production of Tasmanian Merino-based breeds should not be a barrier to manipulation of wool quality (staple strength and fibre diameter) by nutritional management.

scholarly journals PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 261-266
Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  
Keyword(s):  
Management Practices ◽  
Morphological Changes ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Airborne Lidar ◽  
Coastline Change ◽  
The Mean ◽  
The Impact

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>

scholarly journals THE LUCK IN “TALENT VERSUS LUCK” MODELING

2020 ◽  
Vol 23 (03) ◽  
pp. 2050007
Author(s):  
SEAN ELVIDGE
Keyword(s):  
Mean Value ◽  
Maximum Amount ◽  
Random Numbers ◽  
Individual Parameter ◽  
Input Parameters ◽  
The Mean ◽  
Model Variability ◽  
The Impact ◽  
The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

Evidence for epidermal growth factor (EGF)-induced intermolecular autophosphorylation of the EGF receptors in living cells

1990 ◽  
Vol 10 (8) ◽  
pp. 4035-4044
Author(s):  
A M Honegger ◽  
A Schmidt ◽  
A Ullrich ◽  
J Schlessinger
Keyword(s):  
Signal Transduction ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Egf Receptor ◽  
Living Cells ◽  
Egf Receptors ◽  
Receptor Molecule ◽  
Epidermal Growth ◽  
Negative Mutant

In response to epidermal growth factor (EGF) stimulation, the intrinsic protein tyrosine kinase of EGF receptor is activated, leading to tyrosine phosphorylation of several cellular substrate proteins, including the EGF receptor molecule itself. To test the mechanism of EGF receptor autophosphorylation in living cells, we established transfected cell lines coexpressing a kinase-negative point mutant of EGF receptor (K721A) with an active EGF receptor mutant lacking 63 amino acids from its carboxy terminus. The addition of EGF to these cells caused tyrosine phosphorylation of the kinase-negative mutant by the active receptor molecule, demonstrating EGF receptor cross-phosphorylation in living cells. After internalization the kinase-negative mutant and CD63 have separate trafficking pathways. This limits their association and the extent of cross-phosphorylation of K721A by CD63. The coexpression of the kinase-negative mutant together with active EGF receptors in the same cells suppressed the mitogenic response toward EGF as compared with that in cells that express active receptors alone. The presence of the kinase-negative mutant functions as a negative dominant mutation suppressing the response of active EGF receptors, probably by interfering with EGF-induced signal transduction. It appears, therefore, that crucial events of signal transduction occur before K721A and active EGF receptors are separated by their different endocytic itineraries.

EGF promotes gastric mucosal restitution by activating Na+/H+exchange of epithelial cells

2002 ◽  
Vol 282 (5) ◽  
pp. G866-G876 ◽  
Author(s):  
Akinori Yanaka ◽  
Hideo Suzuki ◽  
Takeshi Shibahara ◽  
Hirofumi Matsui ◽  
Akira Nakahara ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Egf Receptor ◽  
Mucous Cells ◽  
Egf Receptors ◽  
Intracellular Acidosis ◽  
Receptor Antibody ◽  
Epidermal Growth ◽  
Triton X ◽  
Stimulation Of

This study was conducted to determine whether the contributions of epidermal growth factor (EGF) to gastric mucosal restitution after injury are mediated by stimulation of Na+/H+exchangers in surface mucous cells (SMC). Intact sheets of guinea pig gastric mucosae were incubated in vitro. Intracellular pH (pHi) in SMC was measured fluorometrically, using 2′,7′- bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein. Restitution after Triton X-100-induced injury was evaluated by recovery of electrical resistance. At neutral luminal pH, exogenous EGF (ex-EGF) increased pHiand enhanced restitution in the absence but not in the presence of serosal HCO[Formula: see text]. During exposure to luminal acid, ex-EGF not only prevented intracellular acidosis but also promoted restitution. These effects of ex-EGF were blocked by serosal amiloride or anti-EGF-receptor antibody. In the absence of ex-EGF, restitution was inhibited by replacement of luminal and serosal solutions with fresh solutions and was blocked more completely by serosal anti-EGF-receptor antibody. These results suggest that both endogenous and ex-EGF contribute to restitution via basolateral EGF receptors, with effects mediated, at least in part, by stimulation of basolateral Na+/H+exchangers.

Cardiovascular Risk After Sepsis: Understanding the Role of Statin Indications and the Impact of Clinical Inertia on Prescribing Patterns

2020 ◽  
Vol 25 (6) ◽  
pp. 541-547
Author(s):  
Vedant A. Gupta ◽  
Talal S. Alnabelsi ◽  
Sandipan Shringi ◽  
Steve W. Leung ◽  
Vincent L. Sorrell
Keyword(s):  
Cohort Analysis ◽  
Prescribing Patterns ◽  
Clinical Inertia ◽  
Major Adverse Cardiovascular Events ◽  
Prescribing Practices ◽  
Retrospective Cohort Analysis ◽  
The Mean ◽  
The Impact ◽  
Statin Use

Introduction: Patients with sepsis have high rates of major adverse cardiovascular events (MACE) in the literature, but the stratification of those at risk has been limited. Statin indicated groups provides clear criteria for therapy, but the risk of MACE after sepsis based on these groups has never been assessed. Materials and Methods: This was a retrospective cohort analysis conducted on adult patients admitted from January 1, 2013, to December 31, 2013, with suspected or confirmed sepsis and data available on statin use. Patients’ past medical history; statin use prior, during, or at time of discharge; and occurrence of MACE were recorded from electronic health records. Result: A total of 321 patients were screened and 265 were found to have data available on statin use. The mean age of the patients was 59 ± 15 years and 47% were female. Overall, 9% were observed to have a MACE at 1 year, with significantly higher rates in those in a statin indicated group (12.2%). On admission, 174 patients were not taking a statin out of whom 52% were in a statin indicated group. Among those in a statin indicated group who survived to hospital discharge, only 10% not on a statin on admission received a statin on discharge, whereas 89% on a statin on admission received a statin on discharge. Conclusion: There is a high risk of MACE after sepsis especially among those in statin indicated groups with significant clinical inertia in prescribing practices.

Effect of time of joining and rate of stocking on the production of Corriedale ewes in southern Victoria. 3. Wool growth and the composition and availability of pasture

1975 ◽  
Vol 15 (73) ◽  
pp. 159 ◽  
Author(s):  
PA Kenney ◽  
IF Davis
Keyword(s):  
Fibre Diameter ◽  
Late Pregnancy ◽  
The Other ◽  
Early Lactation ◽  
Stocking Rate ◽  
Wool Production ◽  
Wool Growth ◽  
The Mean ◽  
Brome Grass ◽  
Stocking Rates

A study was made during a three year period (1 968-1 970) of wool production by a flock of 540 ewes grazing annual pasture at Werribee, Victoria. The ewes were stocked at three rates (5, 7 1/2 and 10 ewes ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Fibre diameter and length of wool samples were measured in 1968, 1969 and 1970 ; in 1970 growth of greasy wool was calculated from staples of dye-banded wool. Wool growth was reduced in all ewes during late pregnancy and early lactation but was not affected during late lactation in ewes lambing in September. The proportion of tender fleeces from all ewes was greater in 1970 and the weight of fleeces from only those ewes bearing single lambs was less in all years for ewes lambing in July than for ewes lambing in September. More ewes were barren and fewer ewes had twins in July and consequently the mean fleece weights of all ewes from both groups were similar. Fleeces from ewes stocked at 10 ha-1 were lighter, shorter and finer than fleeces from ewes stocked at 5 and 7 1/2 ha-1, but the proportion of tender fleeces did not differ between the groups. Wool production of ewes stocked at 5 and 7 1/2 ha-1 increased from 1968 to 1970, whereas that of ewes at 10 ha-1 did not. This was associated with differences in pasture availability and composition. At 10 ewes ha-1 less pasture was present in winter and spring in 1970 than in 1968, whereas at the other stocking rates it was greater. In 1970 the density of weeds in autumn was greater and in spring more silver grass (Vulpia spp.) and less brome grass (Bromus spp.) was available at the high stocking rate.

Fibre diameter and staple strength of sheep selected for divergent clean fleece weight when subjected to an increase in intake or an increase in intake and diet change

2005 ◽  
Vol 56 (2) ◽  
pp. 195 ◽  
Author(s):  
M. A. Friend ◽  
G. E. Robards
Keyword(s):  
Growth Rate ◽  
Stepwise Regression ◽  
Fibre Diameter ◽  
Dietary Treatment ◽  
Diet Change ◽  
Wool Growth ◽  
Ad Libitum ◽  
Staple Strength ◽  
Fleece Weight ◽  
Ad Libitum Feeding

Merino wethers with a high (fleece plus, Fl+) or low (fleece minus, Fl–) potential for wool growth were offered a restricted intake of either oat grain or lucerne chaff for 8 weeks followed by ad libitum lucerne chaff for 4 weeks. The Fl– sheep that were fed oats then lucerne had a lower (P < 0.05) intake during the first 2 weeks of ad libitum feeding than all other groups. Staple strength of Fl+ sheep (37.5 ± 2.2 N/ktex) was less (P < 0.05) than that of Fl– sheep (44.5 ± 2.4 N/ktex), and dietary treatment did not significantly affect staple strength. Wool growth rate was unaffected by dietary treatment, but was greater (P < 0.001) for Fl+ (6.4 ± 0.2 µg/mm2.day) than for Fl– (4.0 ± 0.2 µg/mm2.day) sheep. Along-fibre variation in diameter was greater (P < 0.001) in Fl+ (15.6 ± 0.5%) than in Fl– (9.9 ± 0.5%) sheep. Between-fibre variation in diameter was greater (P < 0.001) in Fl+ (16.5 ± 0.5%) than in Fl– (13.2 ± 0.5%) sheep, and between-fibre variation in diameter was affected (P < 0.05) by dietary treatment in Fl+ sheep. Staple strength was significantly correlated (P < 0.05) with along-fibre variation in diameter (r = –0.48), and stepwise regression analysis indicated that along-fibre variation in diameter, wool growth rate during early restricted feeding, and minimum fibre diameter explained 63% of the variance in staple strength. The results are discussed in relation to the lower staple strength of Fl+ sheep.

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