Effect of photo-translation on fleece growth in cashmere goats

1987 ◽  
Vol 38 (4) ◽  
pp. 765 ◽  
Author(s):  
BJ McDonald ◽  
WA Hoey
Keyword(s):  
Growth Rate ◽  
Volume Growth ◽  
Continuous Light ◽  
Natural Light ◽  
Cyclic Activity ◽  
Cycle Amplitude ◽  
Pineal Function ◽  
Cashmere Goats ◽  
The One ◽  
Mean Cycle

Cyclical changes in fleece parameters were studied in mature feral doe goats exposed to either natural light (NL) followed by continuous light (CL) then NL, or CL followed by NL then CL.Results show that both initial translocations (NL-CL and CL-NL) were recognized immediately and reflected in changes in volume growth rate, length, diameter, brush end fibres of cashmere and cashmere : hair ratio. Cyclic activity continued after the change in photoperiod. Progressive alterations in cycle amplitude, period and frequency appeared in CL following the initial NL-CL change. Following the initial CL-NL change, cycles of some cashmere fleece parameters continued to be influenced by previous CL exposure and did not immediately adopt NL cyclicity. Mean cycle periods of 252-261 days were common to all CL photoperiods and to NL following CL. This suggests that CL exposes a unique cycle of fleece growth, which is independent of photoperiod and retained for some time after the cessation of CL, owing to transient modification of pineal function. Differences between the response to the first and second translocation may be a function of interactions between the cycle status and translocation, rather than solely the change from one photoperiod to another.The NL-CL change resulted in two cycles of cashmere growth in the 392 days following the initial translocation. This would allow two fleeces to be harvested during that time compared with the one expected in NL alone. Exploitation of this principle may represent an opportunity to increase cashmere production.

Cyclical fleece growth in cashmere goats

1987 ◽  
Vol 38 (3) ◽  
pp. 597 ◽  
Author(s):  
BJ McDonald ◽  
WA Hoey ◽  
PS Hopkins
Keyword(s):  
Volume Growth ◽  
Fibre Diameter ◽  
Continuous Light ◽  
Growth Period ◽  
Cycle Period ◽  
Circannual Cycles ◽  
Cumulative Length ◽  
Cashmere Goats ◽  
One Year ◽  
June July

Seasonal changes in fleece parameters were studied in mature feral doe goats, known to produce commercial quantities of cashmere and housed in natural light (NL) or continuous light (CL).Circannual changes in volume growth rate (VGR) of cashmere in NL were asynchronous with those of hair, resulting in maxima in April and November respectively, indicating that follicle-specific mechanisms are controlling the rate of follicle activities.Cycles of cumulative length of cashmere and hair in NL were synchronous. Cashmere maxima of 64.0 and 62.3 mm occurred in June and July respectively for two consecutive years. Distinct circannual cycles of linear growth (period, 365 days) were evident. While exposure to CL initially reduced the cycle period, after 2 years an extended cycle period emerged; this may have been due to photodesensitization.In NL, cashmere fibre diameter minima occurred at June-July and February each year. Hair fibres underwent only one cycle of diameter change each year. The period of the cycles was reduced by CL.An annual cycle of cashmere brush end fibre formation was apparent in NL. This cycle was associated with the cessation of growth in June-July, and a subsidiary event occurred between December and March. Continuous light accelerated brush end formation.Cyclic fibre shedding produced a circannual rhythm in fleece composition with maximum cashmere: hair ratio (CHR) in April-May in non-breeding goats. The maximum CHR of 5.9: 1 in NL did not reach its potential, as illustrated by the follicle S:P ratio of 6.9:1 in the skin. This suggests an irreversible loss of cashmere fibres from the fleece following the cycle of brush end formation in February.The maximum mean length of cashmere and time of occurrence were similar in grazing and penned does, although grazing does were only sampled in 4 months of one year.

TESTICULAR AND PINEAL FUNCTION IN FERRETS EXPOSED TO CONTINUOUS LIGHT OR DARKNESS

1971 ◽  
Vol 68 (1_Supplb) ◽  
pp. S26
Author(s):  
Michael J. Baum ◽  
J. T. M. Vreeburg ◽  
M. G. M. Balemans
Keyword(s):  
Continuous Light ◽  
Pineal Function

Biology of Oscillatoria cf. chalybea, a 2-methylisoborneol producing blue-green alga of Mississippi catfish ponds

1995 ◽  
Vol 31 (11) ◽  
pp. 173-180 ◽  
Author(s):  
M. van der Ploeg ◽  
M. E. Dennis ◽  
M. Q. de Regt
Keyword(s):  
Growth Rate ◽  
Specific Growth ◽  
Light Availability ◽  
Continuous Light ◽  
Light Cycle ◽  
Blue Green Alga ◽  
Continuous Cultures ◽  
Effects Of Temperature ◽  
Catfish Ponds ◽  
Specific Growth Rates

Relative abundance of Oscillatoria cf. chalybea was monitored during May-November, 1993, in 40 ponds at four catfish farms located 50-100 km apart in west central Mississippi, USA. The occurrence of O. cf.chalybea coincided with the period that water temperatures remained above 20°C. In 70% of ponds, O. cf.chalybea was present for a period of 2-20 weeks. The alga recurred in all ponds where it had been present in 1990 and 1991. The effects of temperature and light availability on growth rate and 2-methylisoborneol (MIB) production of O. cf. chalybea were studied in continuous cultures. At 28°C, maximum specific growth rates were 0.8 d−1 (24 h light) and 0.6 d−1 (14 h light :10 h dark). Algal cells contained less MIB when adapted to the shorter light cycle than when grown under continuous light. Specific growth rate of O. cf.chalybea dropped from 0.3 to 0.1 d−1 when temperature was changed from 21 to 19.5°C (14 h light).

scholarly journals ECOLOGICAL STUDIES ON NEPENTHES AT BARITO ULU, CENTRAL KALIMANTAN, INDONESIA

2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Muhammad Mansur
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Stem Length ◽  
Ecological Studies ◽  
Central Kalimantan ◽  
Length Growth ◽  
Small Plot ◽  
Heath Forest ◽  
One Year ◽  
The One

Ecological studies on the Nepenthes species at Barito Ulu, Central Kalimantan, Indonesia were conducted between August 2005 and September 2006. Surveys and two small plot inventories were used to determine the diversity and population of Nepenthes at the study site. We found eight Nepenthes species around the BaritoUlu study area: N. albomarginata, N. ampullaria, N. gracilis, N. hirsuta, N. rafflesiana, N. reinwardtiana, N. stenophylla, and N. hispida. Plot A was dominated by N. rafflesiana with one other species found; whilst in plot B we found five species but it was also dominated by N. rafflesiana. In plot A, the one year stem length growth rate of N. albomarginata was faster than N. rafflesiana (5.0 and 3.5 cm respectively). While in plot B, N. gracilis (21.7 cm) and N. reinwardtiana (13.1 cm) showed faster growth rates than N. albomarginata (5.2 cm), N. rafflesiana (7.0 cm) and N. stenophylla (8.5 cm). Generally, the habitat of Nepenthes in the study site is heath forest.

scholarly journals Structural changes and economic growth in the world economy and Russia

2019 ◽  
Vol 5 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Valeriy V. Mironov ◽  
Liudmila D. Konovalova
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
Global Economy ◽  
World Economy ◽  
Structural Changes ◽  
Russian Economy ◽  
The World ◽  
Preliminary Version ◽  
The One ◽  
Relationship Of

The article considers the problem of the relationship of structural changes and economic growth in the global economy and Russia in the framework of different methodological approaches. At the same time, the paper provides the analysis of complementarity of economic policy types, which, on the one hand, are aimed at developing the fundamentals of GDP growth (institutions, human capital and macroeconomic stabilization), and on the other hand, at initiating growth (with stable fundamentals) with the help of structural policy measures. In the study of structural changes in the global economy, new forms of policies of this kind have been revealed, in particular aimed at identifying sectors — drivers of economic growth based on a portfolio approach. In a given paper a preliminary version of the model of the Russian economy is provided, using a multisector version of the Thirlwall’s Law. Besides, the authors highlight a number of target parameters of indicators of competitiveness of the sectors of the Russian economy that allow us to expect its growth rate to accelerate above the exogenously given growth rate of the world economy.

scholarly journals The workers of the Donbas coal mines in the post reform period

2019 ◽  
pp. 15-20
Author(s):  
І.В. Довжук
Keyword(s):  
Growth Rate ◽  
Child Labor ◽  
High Growth ◽  
High Growth Rate ◽  
Coal Industry ◽  
The Other ◽  
Donets Basin ◽  
Reform Period ◽  
The One ◽  
Intensive Development

The article deals with the problems of providing labor in the coalmines of the Donets Basin in the post reform period. Attention is drawn to the use of female and child labor in the production process, and the conditions under which this happened are being ascertained. It is noted that the intensive development of the coal industry in the 1880-1890s led, on the one hand, to a high growth rate in the number of workers employed in coal mining, and on the other, it exacerbated the deficit of this category of workers. Gradually, with the development of industry in the region, a constant contingent of miners took shape.  As a result, the so-called mining families began to form in the coal industry of Donbass, which later became a tangible source of replenishing the ranks of workers.

Numerical Analysis of the Effect of Diffusion and Creep Flow on Cavity Growth

2007 ◽  
Author(s):  
Frederick W. Brust ◽  
Joonyoung Oh
Keyword(s):  
Growth Rate ◽  
Numerical Method ◽  
Cavity Growth ◽  
Volume Growth ◽  
Numerical Results ◽  
Shape Evolution ◽  
Cavity Volume ◽  
Cavity Shape ◽  
Cavity Growth Rate ◽  
Fully Coupled

In this paper, intergranular cavity growth in regimes, where both surface diffusion and deformation enhanced grain boundary diffusion are important, is studied. In order to continuously simulate the cavity shape evolution and cavity growth rate, a fully-coupled numerical method is proposed. Based on the fully-coupled numerical method, a gradual cavity shape change is predicted and this leads to an adverse effect on the cavity growth rates. As the portion of the cavity volume growth due to jacking and viscoplastic deformation in the total cavity volume growth increases, the initially spherical cavity evolves to V-shaped cavity. The numerical results are physically more realistic compared to results in the previous studies. The present numerical results suggest that the cavity shape evolution and cavity growth rate based on an assumed cavity shape, whether spherical or crack-like, cannot be used in this regime due to transitional coupled growth mechanisms.

scholarly journals Planet formation by pebble accretion in ringed disks

2020 ◽  
Vol 638 ◽  
pp. A1 ◽  
Author(s):  
A. Morbidelli
Keyword(s):  
Growth Rate ◽  
Upper Bound ◽  
Planet Formation ◽  
Accretion Rate ◽  
Central Star ◽  
Giant Planets ◽  
Type I ◽  
Dust Density ◽  
Dominant Process ◽  
The One

Context. Pebble accretion is expected to be the dominant process for the formation of massive solid planets, such as the cores of giant planets and super-Earths. So far, this process has been studied under the assumption that dust coagulates and drifts throughout the full protoplanetary disk. However, observations show that many disks are structured in rings that may be due to pressure maxima, preventing the global radial drift of the dust. Aims. We aim to study how the pebble-accretion paradigm changes if the dust is confined in a ring. Methods. Our approach is mostly analytic. We derived a formula that provides an upper bound to the growth of a planet as a function of time. We also numerically implemented the analytic formulæ to compute the growth of a planet located in a typical ring observed in the DSHARP survey, as well as in a putative ring rescaled at 5 AU. Results. Planet Type I migration is stopped in a ring, but not necessarily at its center. If the entropy-driven corotation torque is desaturated, the planet is located in a region with low dust density, which severely limits its accretion rate. If the planet is instead near the ring’s center, its accretion rate can be similar to the one it would have in a classic (ringless) disk of equivalent dust density. However, the growth rate of the planet is limited by the diffusion of dust in the ring, and the final planet mass is bounded by the total ring mass. The DSHARP rings are too far from the star to allow the formation of massive planets within the disk’s lifetime. However, a similar ring rescaled to 5 AU could lead to the formation of a planet incorporating the full ring mass in less than 1/2 My. Conclusions. The existence of rings may not be an obstacle to planet formation by pebble-accretion. However, for accretion to be effective, the resting position of the planet has to be relatively near the ring’s center, and the ring needs to be not too far from the central star. The formation of planets in rings can explain the existence of giant planets with core masses smaller than the so-called pebble isolation mass.

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