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901.
Two experimental groups and series were compared (leghorns and broilers as well as two age groups of broilers) for their adaptive responses to repeated noise application. The noise was 100 dB and applied daily 30 minutes. The reference for comparison was the plasma-11-hydroxycorticosteroid concentration (11-OHKS). The results differed somewhat from those obtained earlier from one first short-time noise application, in that the rise in plasma glucocorticosteroid concentrations dropped from 431 to 210 per cent of the initial values in adult leghorns exposed to repeated noise stress over seven days. Adult broilers, however, did not exhibit any difference in the magnitude of rise of 11-OHKS concentrations by comparison between first and seven days of repeated stress. The initial values, however, were reached earlier by repeated noise application.  相似文献   
902.
Fifty six 1,2,3-benzothiadiazoles and related compounds were evaluated as carbaryl synergists against the house fly (Musca domestica). Many of these were excellent synergists, the most active being those containing various combinations of halogen, alkyl, or alkoxy substituents in the 5- and/or 6-positions of the ring.Regression analysis on the data from 14 compounds for which substituents constants were available established that synergistic activity can be satisfactorily described by equations in terms of the hydrophobic bonding constant (π) and the homolytic free radical constant (σ ·).The results with compounds related to the 1,2,3-benzothiadiazoles suggest that synergistic activity is associated primarily with the diazosulfide moiety.  相似文献   
903.
Bacillary rickettsia-like organisms (BRLO) were found in the tick Dermacentor marginatus. They are gram-negative and differ from common bacteria and reckettsiae both in the cultivation conditions and morphology. BRLO are non-pathogenic for ticks and guinea pigs. In our studies they were isolated on half-engorged females of D. marginatus, on which they are still maintained.  相似文献   
904.
Concentrations of dieldrin in aquatic insects, crayfish, minnows, and small carpsuckers, and muscle tissue of channel catfish (Ictalurus punctatus) were compared with the dieldrin content of Des Moines River water in 1971-73. Monthly mean concentrations of dieldrin in river water and most aquatic organisms were highest in June and July, soon after aldrin had been applied to corn land in the watershed. Several groups of aquatic organisms also exhibited high dieldrin levels in the fall when the dieldrin content of river water was seasonally low. The influence of temperature on metabolic rate and enzyme activity and the differences in body fat content were suggested as probable causes of variations observed in the dieldrin content of aquatic organisms.  相似文献   
905.
Through the use of a critical electrolyte concentration staining technique, the glycosaminoglycans (GAGs) in the nucleus pulposus region of the canine intervertebral disc were arbitrarily identified as "hyaluronic acid", chondroitin sulphate and keratan sulphate. Approximate estimates of GAG concentration could be qualitatively deduced by determining the appropriate GAG "ALCIANOPHILIC INDEX". This index was considered to be an effective qualitative adjunct to chemical quantitation of GAGs in the intervertebral disc.  相似文献   
906.
A new syndrome, characterised by acute respiratory distress and by abnormalities of the skin, hair and thyroid, was the apparent cause of neonatal death in 35 (24 per cent) of 146 piglets sired by a large white boar in four small commercial pig units. The syndrome appears to be of genetic origin, inherited as an autosomal recessive trait. Its similarities with the respiratory distress syndrome (RDS) of the newborn infant and the "barker" syndrome of the newborn foal are discussed.  相似文献   
907.
908.
A very low virus level was found for a short time in the blood of ducklings and goslings after experimental Lednice (Yaba 1) virus infection by subcutaneous (scut) and intranasal (inas) route and in blood of ducklings also after infection by intracerebral (icer) route. Subsequently virus neutralizing antibody formation was examined. Antibody formation was found in most of animals. In goslings onset of antibody formation seems to be slower than in ducklings after the same virus infection dose; vice versa, in ducklings antibody titer decreased after 6 weeks. Using low infection virus dose, neutralizing antibody level in ducklings was lower than in the former case. On examining the blood and the organs, the virus was detected in a very low amount and for a very short time in blood and spleen of goslings and only in blood of ducklings.  相似文献   
909.
Four experiments were conducted at six week intervals to determine the seasonal activity and persistence of soil-incorporated EPTC (5-ethyl N,N-dipropyl(thiocarbamate)) for Cyperus rotundus L. control and tolerance of okra (Hibiscus esculentus L.), cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.), red beet (Beta vulgaris L.) and carrot (Daucus carota L.) during the dry and wet seasons in Viçosa, Brazil. Satisfactory control of C. rotundus was obtained at 2 kg/ha EPTC during the dry season and 4 kg/ha or more during the wet season. Only red beet and carrot tolerated these doses of EPTC when the crops were planted five days after application. However, selective control of C. rotundus was obtained when the planting date of lettuce was delayed for three or six weeks after EPTC application. EPTC controlled C. rotundus at half the dose that was required to control three species of annual grass that germinated near the soil surface. EPTC persisted longer when applied to air dry soil and incorporated with a rototiller than when incorporated into moist or wet soil.  相似文献   
910.
The genetics and biochemistry of oxidative resistance to diazinon were investigated in a diazinon-resistant strain of the house fly, Musca domestica L. The resistant strain was crossed with a multimarker susceptible strain and substrains containing portions of the resistant strain genome were prepared. Resistance, microsomal oxidase, and cytochrome P-450 spectral characteristics were then compared in the different strains. The major gene for resistance to diazinon is semidominant and is located on chromosome II, 13 crossing over units from the recessive mutant stubby wing. Additional resistance genes occur on chromosome II and on other chromosomes as well. Resistance to diazinon was introduced into a susceptible mutant-marked strain via genetic crossing over. Increases in parathion oxidase, total and P-450-specific N- and O-demethylase activity, and resistant strain type I binding spectrum were introduced along with resistance, indicating genes controlling these parameters and resistance are either identical or closely linked. No increase in activity of cytochrome P-450 itself was introduced into the mutant strain. Additional genes controlling the amount of cytochrome P-450 and several spectral changes characteristic of the resistant strains are apparently controlled by genes located at different loci on chromosome II. Resistance factors on other chromosomes are also present, but were not characterized.  相似文献   
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