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31.
The performance of The Subhuman Primate Pregnancy Test Kit was evaluated for routine detection of early (days 19-21) pregnancy in the rhesus monkey. Out of 123 confirmed matings, 19 resulted in pregnancy. In the pregnant animals the kit had an accuracy of 73.7%. In the nonpregnant females the accuracy was higher, 88.5%. False positives were encountered in ovariectomized females as well as adult intact males. 相似文献
32.
Synopsis Laboratory studies were conducted on 15 schools of blackchin shiners, Notropis heterodon, to determine if they altered their structure in response to changing environmental demands. The hypothesis tested was that fish schools should sacrifice a flat, hydrodynamically efficient structure in favour of an unobstructed visual field in the presence of a predator by staggering in the vertical plane. Ten schools were exposed for two weeks to a simple environment with only a current. For the next two-week period a predator was added. Five control schools were exposed to the simple environment for both two-week periods. Six of the ten treated schools increased their staggering in the vertical dimension as predicted while none of the control schools changed. This result was suggestive that hydrodynamic advantages were sacrificed. Respirometer experiments indicated these fish were capable of achieving some hydrodynamic benefits from schooling but these benefits may be a function of fish size. 相似文献
33.
An electrophoretic procedure for separating the molecular forms of catechol-O-methyltransferase in cellulose acetate gel is described; the zones of enzyme activity were revealed by autoradiography. The electrophoretic patterns of the enzyme in several tissues and cell lines derived from four different species are presented.This investigation was supported by Grant 500.6/Ric. 70/1981 from the Italian Ministry of Health and by the Italian Ministry of Education. We are grateful to Dr. M. Castagnola for useful advice and help with thin-layer chromatography. 相似文献
34.
Summary Striated Ciliary Roots (SCRs), about 3 m long, are attached to the basal bodies of branchial crown ciliated epithelial cells ofOwenia. These SCRs appear to consist of 5–7-nm diameter filaments organized in a cross-striation pattern with an apparent variable periodicity of 50 to 80 nm. The most exciting observation emerging from this study is the constant and conspicuous close spatial relationship between SCRs and fairly well developed Golgi apparatus. By enhancing contrast and preservation of cell components, the OsFeCN postfixation-staining of material prefixed in glutaraldehyde in the presence of calcium has revealed some fine-structural details within the SCR-Golgi Association. By means of the calcium precipitation method, with antimonate or oxalate in conjunction with X-ray microanalysis, we have identified calcium within SCR dark bands and SCR-associated Golgi bodies. The ability to bind calcium makes the Golgi apparatus a likely candidate for Ca2+ regulation of putative contraction of the SCRs and/or ciliary motility. The slight period variability measured in the SCRs and cytochemical localization of Mg2+, Ca2+-dependent ATPase activities associated with cross striations support the view that theOwenia SCRs may be contractile organelles.The striking and specific close structural association between the Golgi apparatus and the SCR showing Ca2+-binding capabilities suggests that some sort of Ca2+-mediated functional relationship between these organelles may exist.Abbreviations SCR
striated ciliary root
- OsFeCN method
osmium tetroxide-ferricyanide method
- EDTA
ethylenediamine tetraacetic acid
- EGTA
ethyleneglycol-bis-(-aminoethyl ether) N,N-tetraacetic acid
- ATP
adenosine 5-triphosphoric acid
- ATPase
adenosine triphosphatase
- ASW
artificial sea-water 相似文献
35.
Breeding vervet monkeys in a closed environment 总被引:1,自引:0,他引:1
J V Seier 《Journal of medical primatology》1986,15(5):339-349
A breeding group of vervet monkeys produced 95 offspring over five years. Fetal wastage for 114 pregnancies was 16.7%. Uterine sizes were recorded for 103 pregnancies in various stages of gestation. This enabled diagnosis of pregnancy, estimation of stage of gestation, and prediction of parturition to within two weeks. Detailed observations were made on dental eruption, pelage development, and growth of 57 infants. 相似文献
36.
Quantitative determination of 5-methylcytosine in DNA by reverse-phase high-performance liquid chromatography 总被引:7,自引:0,他引:7
A method to separate the four major bases (cytosine, guanine, thymine and adenine) and the two minor modified bases (5-methylcytosine and 6N-methyladenine) in DNA has been developed. For optimal separation, several different buffer systems are available for isocratic elution. The 12 5-methylcytosine (5-mC) residues in the plasmid pBR322 can be determined with a deviation of less than 3% of the expected value and have been used for internal standardization. Formic acid hydrolysis of bases and probably of DNA does not lead to the deamination of cytosine or 5-mC and thus can be used routinely for DNA hydrolysis. Adenovirus or baculovirus DNA does not contain detectable amounts of 5-mC. The distribution of 5-mC in hamster cell DNA appears to be nonrandom in that different 5'-CpG-3'-containing restriction sites are methylated to different extents. 相似文献
37.
Abstract: A simple, rapid method is presented for the determination of acetylcholine (ACh) and choline (Ch) in neuronal tissue using HPLC with electrochemical detection. The method is based on the separation of ACh and Ch by reverse-phase HPLC and mixing the effluent as it emerges from the column with acetylcholinesterase and Ch oxidase, which converts endogenous Ch and Ch produced by the hydrolysis of ACh to betaine and hydrogen peroxide. Production of hydrogen peroxide is continuously monitored electrochemically. The sensitivity of the procedure is 1 pmol for Ch and 2 pmol for ACh. Specificity of the method is based on HPLC, two specific enzymatic reactions, and the detection of hydrogen peroxide. 相似文献
38.
Willy R. G. Baeyens Betty Lin Ling Udo A. Th. Brinkman Stephen G. Schulman 《Luminescence》1989,4(1):484-499
An overview is presented of the physicochemical basis of luminescence, and its application to the detection of chemicals (drugs, biomedically important compounds, environmentally active substances) in liquid chromatographic systems. 相似文献
39.
Integration time for short broad band clicks in echolocating FM-bats (Eptesicus fuscus) 总被引:2,自引:2,他引:0
A. Surlykke O. Bojesen 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,178(2):235-241
Vespertilionid FM-bats (four Eptesicus fuscus and one Vespertilio murinus) were trained in an electronic phantom target simulator to detect synthetic echoes consisting of either one or two clicks. The threshold sound pressure for single clicks was around 47 dB peSPL for all five bats corresponding to a threshold energy of -95 dB re 1 Pa2 * s. By varying the interclick interval, T, for double clicks it was shown that the threshold intensity was around — 3 dB relative to the threshold for single clicks at T up to 2.4 ms, indicating perfect power summation of both clicks. A threshold shift of -13.5 dB for a 1 ms train of 20 clicks (0.05 ms interclick interval) confirmed that the bats integrated the power of the stimuli. At T longer than around 2.5 ms the threshold for double clicks was the same as for single clicks. Thus, the bats performed like perfect energy detectors with an integration time of approximately 2.4 ms. This integration time is an order of magnitude shorter than that reported for bats listening passively for pure tones. In our setup the bats emitted sonar signals with durations of 2–3 ms. Hence, the results may indicate that while echolocating the bats integration time is adapted to the duration of the sonar emissions.Abbreviations
AGC
automatic gain control
-
FM
frequency modulated
-
peSPL
peak equivalent sound pressure level
-
rms
root mean square
-
SD
standard deviation
-
SE
standard error of mean
-
T
interclick interval 相似文献
40.
L GIUNCHEDI C POGGI POLLINI S BIONDI ANNA ROSA BABINI 《The Annals of applied biology》1994,124(2):399-403
Polymerase chain reaction (PCR) amplification, using primers derived from the 16S rRNA gene, followed by restriction fragment length polymorphism (RFLP) analysis with Alu I restriction endonuclease was used to detect myc-oplasma-like organisms (MLOs) associated with pear decline. MLOs were consistently detected in pear trees that suddenly wilted and died within a few days during summer, as well as in pears of the same orchards with symptoms similar to the slow form of pear decline. In both cases the same RFLP pattern was obtained. Declining pear trees were 5 to 8-yr-old cvs Williams, Kaiser and Max Red Bartlett grafted on to Pyrus communis seedling rootstocks. All the orchards affected by quick decline had severe attacks of pear psyllid (Cacopsylla pyri) during the year this study was performed and during the previous year. The results showed the suitability of DNA amplification by the polymerase chain reaction for the detection of pear decline MLOs and established that MLOs can be detected in infected tissues of dead trees. 相似文献