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101.
For a conditioned taste aversion (CTA) agent to be successful in wildlife management applications, the compound must not be detectable by the animal. Levamisole is an effective CTA agent when administered by oral intubation, but it is readily detected by a number of species when mixed directly in food. This paper describes the development of an ion-exchange resin complex (resinate) to mask the taste of levamisole. Two different resins were evaluated, Amberlite IRP-64 and Amberlite IRP-69, and release studies indicated that the resinate formed using IRP-64 resin would be most suitable for use in wildlife management. Although it contained a relatively low loading of levamisole (77 g kg(-1)), the results indicated that the IRP-64 resinate should be stable in the mouth and release the levamisole quickly in the acid environment of the stomach (93% of levamisole was released into 0.1 M HCl in 5 min). In a bioassay using laboratory rats (Rattus norvegicus Berk), we showed that the taste of levamisole was successfully masked in a biscuit bait using the IRP-64 resinate and that a CTA was generated to untreated bait. The use of ion-exchange resins is a new approach in the taste-masking of CTA agents and could be applied to other wildlife management applications. 相似文献
102.
Bald thigh syndrome (BTS) is a disease limited to Greyhound dogs. It is characterized clinically and grossly by bilateral hair loss on the lateral and caudal thighs. The cause of BTS is unknown but may be associated with hypothyroidism or hyperadrenocorticism. Samples of skin, thyroid glands, and adrenal glands from 43 Greyhound dogs with BTS were examined microscopically. Microscopic changes were characterized by dilatation of follicular infundibula, presence of catagen follicles and epidermal hyperplasia. Changes in the skin from these Greyhound dogs suggest an endocrinopathy as the cause; however, we were unable to confirm which one. 相似文献
103.
Arsenate Displacement from Fly Ash in Amended Soils 总被引:1,自引:0,他引:1
Qafoku Nikolla P. Kukier Urszula Sumner Malcolm E. Miller William P. Radcliffe David E. 《Water, air, and soil pollution》1999,114(1-2):185-198
Arsenic (As) is the biggest environment contaminant in most of the soils where fly ash is applied. Usually, it is not mobile and strongly adsorbed on to soil particles. However, in gypsum and phosphorus amended soils As may be much more mobile. A study in repacked columns was conducted to determine whether or not As becomes mobile when Ca(H2PO4)2and CaSO4are used as leaching solutions, and to compare the competitive interactions between PO4-AsO4and SO4-AsO4. Arsenic concentration in leachate was found to be approximately ten times greater when Ca(H2PO4)2was used to leach the columns as compared to CaSO4. A maximum concentration of 800 μg As L-1was found in the leachate in this case, which is much higher than the groundwater limit of 50 μg L-1for drinking water established by the United States Environmental Protection Agency. In fly ash, the portion of arsenate non-specifically adsorbed is believed to be much lower than that of specifically adsorbed. Sulfate anions were able to displace only non-specifically adsorbed arsenate. In this case the concentration of As in leachate was found to be within acceptable limits. On the other hand, phosphate can compete with arsenate for all available adsorption sites, non-specific and specific. Phosphate displacement of both forms of arsenates increases As mobility in both control and fly ash treatments. 相似文献
104.
Mostafa A.R. Hossain Graham S. Haylor Malcolm C.M. Beveridge 《Aquaculture International》1998,6(5):379-385
Groups of 3–4 g African catfish (Clarias gariepinus Burchell, 1822; Family: Clariidae) were offered feeds of two types in three combinations: feed with a radio-opaque marker (Ballotini, 0.16–0.25 mm), feed without marker and a 50:50 mixture of marked and unmarked feeds. Stomach contents were estimated by X-radiography and gastrectomy just after meal termination and at different time intervals (4, 8, 12, 16, 20, 24, 32, 40 and 48 h). There were no significant differences among treatment groups confirming that there was no effect of the marker on feed preference and evacuation rate. Estimations of gastric evacuation rate calculated from gastrectomy and by X-ray sampling were not significantly different. Therefore, gastric evacuation rate of African catfish can be accurately estimated by feeding marked feed and then using X-radiography to monitor feed passage through the gut. © Rapid Science Ltd. 1998 相似文献
105.
Malcolm Jobling 《Aquaculture International》2010,18(4):715-712
Compensatory growth refers to an animal’s ability to grow extremely rapidly after it has experienced a period of reduced growth.
It is also widely held that the growth trajectories of animals showing compensatory growth converge towards those followed
by conspecifics that have experienced favorable growth conditions throughout their lives. In other words, it is often assumed
that animals undergoing compensatory growth also show some recovery, and thereby exhibit catch-up growth. This belief has
resulted in the terms compensatory growth, recovery growth, and catch-up growth being used as synonyms, and has also created
some problems with regard to data analysis and interpretation. Following a discussion of methods of analysis and their limitations,
a series of growth simulations is presented to illustrate why the terms should not be used as synonyms. The simulations, based
upon the assumption that compensatory growth results in a restoration of body composition (using condition index as a surrogate),
show that compensatory growth is not always accompanied by a convergence of growth trajectories. Compensatory growth can occur
in the absence of catch-up growth, and the simultaneous observation of compensatory growth and a recovery of body mass is
a special combination of events. Further, it is possible for growth trajectories to converge even when animals that have experienced
a period of reduced growth do not display compensatory growth. Definitions are proposed that distinguish between the terms
compensatory growth, recovery growth, and catch-up growth, and guidelines are given relating to the analysis of the results
of fish compensatory growth studies. 相似文献
106.
Bruno O. David Matt Jarvis Deniz
zkundakci Kevin J. Collier Andy S. Hicks Malcolm Reid 《水产资源保护:海洋与淡水生态系统》2019,29(9):1409-1423
107.
Malcolm D. Devine 《Pest management science》1997,51(3):259-264
Resistance to acetyl-coenzyme A carboxylase (ACCase) inhibitors has developed in at least 10 grass weed species in recent years. In most instances, resistance is conferred by an ACCase alteration in the resistant biotypes that reduces sensitivity to aryloxyphenoxypropionate (AOPP) and cyclohexanedione (CHD) herbicides. Analysis of ACCase from many of these resistant weed biotypes suggests the presence of different mutations, each conferring a different pattern and level of resistance to various AOPP and CHD herbicides. In all cases analyzed to date, resistance is controlled by a single dominant or semi-dominant nuclear gene. In several weed biotypes, resistance is conferred by enhanced herbicide detoxification, primarily through elevated expression or activity of cytochrome P450 monooxygenase(s). This mechanism can confer cross-resistance to herbicides from other chemical classes with different modes of action. Finally, multiple herbicide resistance, i.e. the acquisition of several different resistance mechanisms, has been reported in some weed biotypes. ©1997 SCI 相似文献
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