A note on the effect of dentition and age in sheep on the intake of herbage

1983 ◽  
Vol 37 (1) ◽  
pp. 133-136 ◽  
Author(s):  
J. E. Newton ◽  
Caroline Jackson
Keyword(s):  
Organic Matter ◽  
Daily Intake ◽  
Poor Quality ◽  
The Other ◽  
Intermediate Group ◽  
The Difference

ABSTRACTThe intake of ten 5-year-old Masham ewes with good teeth, five 7-year-old Mashams with poor teeth and nine 10-year-old ewes with poor teeth was measured when they were offered long (35·1 cm) or short grass (3·8 cm) outdoors or poor quality hay indoors. The young ewes ate significantly more grass and hay than the old ewes, but the difference in daily intake was greater with long grass (1473 v. 751 g organic matter per head) and with hay (895 v. 421) than with short grass (617 v. 407). The intermediate age ewes ate as much of the long grass and of the hay as the young ewes, but less of the short grass. This suggests that age influenced intake more than did tooth condition, except when short grass was offered.Within the oldest but not within the intermediate group of ewes, there was a significant correlation between the number of incisors and organic matter intake, except with the long grass, but there was no correlation between the number of cheek teeth and intake. When offered hay, the only group with a reduced in vivo digestibility was the intermediate group of ewes, the other two groups having a similar digestibility.There was no correlation between number of incisors or number of molars and in vivo digestibility.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

The effect of exposure to conspecifics on restlessness in the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

2007 ◽  
Vol 139 (5) ◽  
pp. 678-684 ◽  
Author(s):  
B.H. King
Keyword(s):  
Habitat Quality ◽  
Parasitoid Wasp ◽  
Poor Quality ◽  
The Other ◽  
Dispersal Ability ◽  
Nasonia Vitripennis ◽  
Adult Females ◽  
Selection For ◽  
The Difference ◽  
Abundance And Distribution

AbstractWhen habitat quality is variable, there should be strong selection for the ability to detect and respond to the variation. Adult females of the parasitoid wasp Nasonia vitripennis (Walker) are known to increase their restlessness (the proportion of time in locomotion) both during and after exposure to a poor quality host. Doing so provides a mechanism for leaving a poor host and potentially finding a better host. This study examined whether restlessness also changes in response to competition as indicated by the presence of adult conspecifics. Both restlessness and the probability of dispersing across an inhospitable environment were greater when a female was with another female than when she was alone. However, restlessness did not remain elevated after the other female was removed. In contrast with females, restlessness of males did not increase either during or after exposure to other males, and the probability of dispersing across an inhospitable environment was unaffected by the presence of another male. The difference between females and males may be related to differences in dispersal ability and in the abundance and distribution of hosts versus mates.

scholarly journals Optical characteristics of cryoconite (surface dust) on glaciers: the relationship between light absorbency and the property of organic matter contained in the cryoconite

2002 ◽  
Vol 34 ◽  
pp. 409-414 ◽  
Author(s):  
Nozomu Takeuchi
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Visible Region ◽  
The Other ◽  
Optical Characteristics ◽  
The Arctic ◽  
Mineral Particles ◽  
Significant Difference ◽  
The Difference ◽  
Chemical Conditions

AbstractOptical characteristics of the cryoconite collected from nine glaciers in the Himalaya, Tibet and the Arctic (Canada and Svalbard) were analyzed. The spectral light reflectance (visible region) of the cryoconite on the six glaciers in the Arctic and the Himalayawas generally low, indicating high light absorbency (dark coloration) of the cryoconite. In contrast, the spectral reflectances of the cryoconite on the three glaciers in Tibet were significantly higher than on the other glaciers. There was no significant difference in the spectral reflectance of mineral particles contained in the cryoconite between the Tibetan and the other glaciers, indicating that the difference in the albedo of the cryoconites is not due to the mineral particles, but due to organic matter contained in the cryoconite. Chemical analysis of the organic matter in the cryoconites revealed that the light absorbency of cryoconites is due to the amount of humic substances, which are dark-colored organic substances, the residue of bacterial decomposition of organic matter. The cryoconite of the three glaciers in Tibet contained significantly smaller amounts of humic substances than that of the other glaciers, probably due to different biological or chemical conditions. Results show that the formation of the humic substances in the cryoconite affects its optical characteristics, and possibly affects the surface albedo of the glaciers.

The influence of package size and density on the intake of dried grass wafers fed to lambs

1972 ◽  
Vol 14 (3) ◽  
pp. 335-341 ◽  
Author(s):  
R. M. Tetlow ◽  
R. J. Wilkins
Keyword(s):  
Organic Matter ◽  
Daily Intake ◽  
The Other ◽  
Low Density ◽  
Package Size ◽  
Unit Density ◽  
Voluntary Intake

SUMMARYWafers made from dried ryegrass were fed to castrated male lambs in two experiments of 40 and 30 days' duration. In the first experiment, wafers of chopped feed were prepared which varied in unit density from 0·7 g/ml to 1·0 g/ml. In the second experiment, coarsely ground forage was passed through a ram press with a die of 5 cm diameter and the extruded material was then split into quarter and half wafers or left unsplit as whole wafers. Voluntary intake was measured throughout each experiment.For the wafers with density of 1·0 g/ml the daily intake of organic matter was 75 g/kg LW0·75 as compared with 64 g/kg LW0·75 for the wafers with density of 0·7 g/ml but this difference was not significant. There was a significant (P < 0·05) interaction between wafer density and sub-period of the experiment. The daily intake of low-density wafers, expressed in g/kg LW0·75, increased throughout the experiment, whereas that of the higher density wafers did not change.There was no overall effect of package size on organic matter intake, but the interaction between package size and sub-period of the experiment was significant (P · 0·001). The intake of the whole wafers was initially lower than that for the other treatments, but increased throughout the experiment, whereas the intake of the quarter and half wafers remained steady.

scholarly journals Let’s talk about cardiac T1 mapping

2018 ◽  
Author(s):  
Tarik Hafyane ◽  
Agah Karakuzu ◽  
Catherine Duquette ◽  
François-Pierre Mongeon ◽  
Julien Cohen-Adad ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Magnetization Transfer ◽  
The Other ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Recovery Sequence ◽  
Link Type ◽  
The Difference ◽  
Correlation Statistics

ABSTRACTBackgroundRecent reports have shown that T1 mapping sequences agree in phantoms, but exhibit significant differences in vivo. To characterize these differences in the heart, one needs to consider the effects of magnetization transfer (MT) and the T2 relaxation time in the most commonly used cardiac T1 mapping sequences (MOLLI, ShMOLLI and SASHA).MethodsSix explanted pig hearts were scanned weekly over a period of six weeks on a 3T system with the MOLLI, ShMOLLI, SASHA sequences and an inversion recovery sequence as reference. The T1 bias was computed as the difference between MOLLI, ShMOLLI, SASHA and the reference T1 values. We applied robust correlation statistics to assess the relationships between T1, T2 and MT. All data are publicly available at: http://neuropoly.pub/pigHeartsData.ResultsA systematic T1 bias was present for all sequences, with MOLLI and ShMOLLI underestimating T1 and SASHA slightly overestimating T1 compared to the reference. The correlation of T1 bias with T2 was weak and insignificant. However, MT showed significant associations with T1 bias for all sequences. Our analysis is also available at: http://neuropoly.pub/pigHeartsInteractive.ConclusionWe investigated cardiac T1 mapping sequences in a setting that allowed us to explore their accuracy and their dependence on T2 and MT effects. The T2 effects were not significant, and could not explain the T1 bias of MOLLI, ShMOLLI, SASHA with respect to the reference. On the other hand, the T1 biases exhibited a strong correlation with MT. We conclude that inaccuracies in cardiac T1 mapping are primarily due to magnetization transfer.

Retention of energy and nitrogen by young sheep on different feeding patterns

1972 ◽  
Vol 78 (1) ◽  
pp. 7-12 ◽  
Author(s):  
M. Freer ◽  
D. B. Jones ◽  
K. R. Christian
Keyword(s):  
Organic Matter ◽  
Body Fat ◽  
Daily Intake ◽  
Live Weight ◽  
Negative Energy ◽  
The Other ◽  
Feeding Pattern ◽  
Rotational Grazing ◽  
Feeding Patterns ◽  
Cyclic Feeding

SUMMARYIn each of two experiments the comparative slaughter technique was used to compare the retention of energy by young Border Leicester × Merino wethers when the same total amount of food was offered according to two different feeding regimens. These were designed to simulate, in pens with a diet of pelleted lucerne, feeding patterns typical of continuous and intensive rotational grazing.In the first experiment ten 9-month-old sheep that were offered the same amount of food daily (mean intake 367 g digestible organic matter) during each of 14 weeks made mean daily gains of 39 g live weight, 6·3 g body fat and 0·59 MJ (140 kcal) energy compared with a gain of 30 g live weight, a loss of 1·4 g body fat and a gain of 0·28 MJ (67 kcal) energy by a similar group that ate the same total quantity of food but in amounts that ranged, during each week, from 1·8 to 0·1 times the daily intake of the other group. This cyclic feeding pattern caused a small decrease in the digestibility of dietary organic matter.In the second experiment two similar feeding patterns were compared with ten pairs of 3-month-old sheep eating twice as much food each week as in the first experiment. One member of each pair was, in each of 13 weeks, offered food ad lib. for 3 days and then amounts falling to 20% of voluntary intake on the seventh day; the other one ate the same amount of food each week but in seven almost equal feeds. The latter sheep gained, on average, 132 g live weight daily and retained 58 g body fat and 2·96 MJ (707 kcal) energy compared with 124 g live weight, 49 g body fat and 2·61 MJ (624 kcal) energy by the sheep on the cyclic feeding pattern. In neither experiment was wool growth affected by feeding pattern.The greater effect of the cyclic feeding pattern in reducing the efficiency of energy retention in the first experiment is attributed to the higher number of days each week during which these animals were estimated to be in negative energy balance. These results suggest that adverse nutritional effects of a fluctuating feeding pattern in rotational grazing are likely to be most important where sheep are being rationed near their maintenance level and only small where food is ample.

Evidence in Vivo for a Circulating Natriuretic Substance in Rats after Expanding the Blood Volume

1980 ◽  
Vol 59 (6) ◽  
pp. 411-421 ◽  
Author(s):  
Catherine A. Knock ◽  
H. E. De Wardener
Keyword(s):  
Blood Transfusion ◽  
Blood Volume ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
The Other ◽  
Not Given ◽  
The Cross ◽  
The Difference

1. Five rats were volume expanded by infusing a volume of blood equivalent to one-third of the estimated blood volume. In six control experiments the same transfusion was given without expanding the blood volume, as an equal volume of blood was simultaneously removed. Sodium excretion increased significantly more after the blood volume was expanded than in the control experiments. 2. Pairs of rats placed on opposite scale pans of a trip balance were cross-circulated by means of arteriovenous bypasses. The blood volume of the rats could be kept constant by keeping the balance in equilibrium. 3. One of each pair of rats received a blood transfusion which either did or did not expand its blood volume. Sodium excretion was measured in the transfused rat and in the recipient rat, the blood volume of which was kept constant. 4. Sodium excretion in the six recipient rats cross-circulated with rats with an expanded blood volume was not significantly different from that in six recipient rats, cross-circulated with rats given a transfusion which did not expand the blood volume. 5. The cross-circulation experiments were repeated, with the difference that the urine of the transfused rat was reinfused. Under these conditions, sodium excretion in 11 recipient rats cross-circulated with blood volume expanded rats was significantly greater than in eight recipient rats cross-circulated with rats given a transfusion which did not expand the blood volume. 6. In cross-circulation experiments in which a blood transfusion was not given urine reinfusion of one rat did not affect sodium excretion of the other rat. 7. It is concluded that the rise in urinary sodium excretion which occurs in an isovolaemic recipient rat cross-circulated with a urine reinfused rat with an expanded blood volume is due to a change in the concentration of a circulating substance.

scholarly journals Studies on the type division of the typhoid and paratyphoid B bacilli by fermentation

1938 ◽  
Vol 38 (6) ◽  
pp. 688-701 ◽  
Author(s):  
Martin Kristensen
Keyword(s):  
Clinical Course ◽  
Salmonella Typhi ◽  
The State ◽  
The Other ◽  
Biliary System ◽  
Other Hand ◽  
Typhoid Bacillus ◽  
The Difference

No case of transformation (in vivo) of the “xylose-positive” typhoid bacillus to the “xylose-negative”, or vice versa, has been observed in any of the material dealt with at the State Serum Institute, Copenhagen.On the other hand, the types of paratyphoid B bacilli that can be established on the basis of their relation to rhamnose and inositol did not prove to be absolutely constant; actual or apparent transformation of one type to the other having been observed in several cases.In this connexion the suggestion is made that Bitter's rhamnose reaction be omitted; the distinction between types R1 and R2 would thus disappear.Patients with symptoms of diseases of the liver and biliary system and also chronic carriers were represented in greater numbers for type R3I1 than for type R2I1, but it is doubtful whether this observation can be taken as a general one. Apart from this, the behaviour of these two types was very uniform as to the clinical course of the infections they produced. The cases of infection with the rarer types, also, did not seem to vary clinically from those with the more frequent types. On the other hand, the difference between the clinical course of paratyphoid B and the infection with Salmonella typhi murium was very marked.

scholarly journals The force-producing mechanism for centrosome separation during spindle formation in vertebrates is intrinsic to each aster

1993 ◽  
Vol 122 (2) ◽  
pp. 361-372 ◽  
Author(s):  
JC Waters ◽  
RW Cole ◽  
CL Rieder
Keyword(s):  
Opposite Polarity ◽  
Separation Process ◽  
The Other ◽  
Common Mechanism ◽  
Spindle Formation ◽  
Total Displacement ◽  
Centrosome Separation ◽  
The Difference ◽  
And Migration

A popular hypothesis for centrosome separation during spindle formation and anaphase is that pushing forces are generated between interacting microtubules (MTs) of opposite polarity, derived from opposing centrosomes. However, this mechanism is not consistent with the observation that centrosomes in vertebrate cells continue to separate during prometaphase when their MT arrays no longer overlap (i.e., during anaphase-like prometaphase). To evaluate whether centrosome separation during prophase/prometaphase, anaphase-like prometaphase and anaphase is mediated by a common mechanism we compared their behavior in vivo at a high spatial and temporal resolution. We found that the two centrosomes possess a considerable degree of independence throughout all stages of separation, i.e., the direction and migration rate of one centrosome does not impart a predictable behavior to the other, and both exhibit frequent and rapid (4-6 microns/min) displacements toward random points within the cell including the other centrosome. The kinetic behavior of individual centrosomes as they separate to form the spindle is the same whether or not their MT arrays overlap. The characteristics examined include, e.g., total displacement per minute, the vectorial rate of motion toward and away from the other centrosome, the frequency of toward and away motion as well as motion not contributing to separation, and the rate contributed by each centrosome to the separation process. By contrast, when compared with prometaphase, anaphase centrosomes separated at significantly faster rates even though the average vectorial rate of motion away from the other centrosome was the same as in prophase/prometaphase. The difference in separation rates arises because anaphase centrosomes spend less time moving toward one another than in prophase/prometaphase, and at a significantly slower rate. From our data we conclude that the force for centrosome separation during vertebrate spindle formation is not produced by MT-MT interactions between opposing asters, i.e., that the mechanism is intrinsic to each aster. Our results also strongly support the contention that forces generated independently by each aster also contribute substantially to centrosome separation during anaphase, but that the process is modified by interactions between opposing astral MTs in the interzone.

The ability of sheep at different stocking rates to maintain the quality and quantity of their diet during the grazing season

2003 ◽  
Vol 140 (1) ◽  
pp. 113-124 ◽  
Author(s):  
F. GARCIA ◽  
P. CARRÈRE ◽  
J. F. SOUSSANA ◽  
R. BAUMONT
Keyword(s):  
Organic Matter ◽  
Daily Intake ◽  
The Other ◽  
Intake Rate ◽  
Stocking Rate ◽  
Grazing Season ◽  
Trade Offs ◽  
Digestible Organic Matter ◽  
Managed Trade ◽  
Stocking Rates

The degree to which grazers maintain the amount (organic matter intake) or the quality (organic matter digestibility) of their diet without adversely affecting the other component was addressed by investigating how sheep managed trade-offs between quantity and quality throughout the grazing season in an upland area of central France. Two groups of five dry ewes, grazing two plots of contrasting areas from April to the end of September 2000, were studied. On the smaller plot (1500 m2), the application of a high stocking rate (HSR) produced a resource of good quality but in low quantity; and on the larger plot (3000 m2), a low stocking rate (LSR) created a sward of low quality but in good quantity. In spring, in both conditions, the sheep maintained their intake of digestible organic matter (OM) at between 1000 and 1250 g/day. Both organic matter intake and digestibility remained high at both stocking rates. In summer, the intake of digestible OM decreased to between 750 and 1000 g/day. On HSR, this was mainly due to a decline of intake in relation to the decrease of intake rate and bite weight. On LSR a decrease in digestibility and to a lesser extent in intake was involved. At both stocking rates, the sheep maximized the digestibility of their diet by selecting the green laminae throughout the grazing season. In spring, the sheep modulated their daily grazing time to compensate the decrease in intake rate and maintained a high daily intake. In summer and autumn, the sheep failed to maintain their daily intake at the same level as previously observed. On both plots they modulated their daily grazing time to cover their needs (730 g/day), but they did not increase it further to maximize daily intake. This may be attributable to the costs involved in selecting (LSR) or taking (HSR) the best components from the sward.

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