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991.
1. Larvae of antlions (Neuroptera: Myrmeleontidae) and wormlions (Diptera: Vermileonidae) display a convergently evolved sit‐and‐wait hunting strategy of building pitfall traps in sandy areas. This study investigated a sympatric population of antlions and wormlions in the lowland rainforest of Borneo for substrate moisture, particle size and temperature preferences. It was hypothesised that these animals would show different preferences regarding these microhabitat traits. 2. The results showed that antlions had a higher aversion to moisture compared with wormlions, but that wormlions had a higher preference for small‐particle sand. Furthermore, thermal preferences in antlions and wormlions were significantly different, with antlions choosing higher temperatures. 3. The detected differences between antlions and wormlions might contribute to their niche partitioning in the mixed Bornean population and thus facilitate coexistence of these animals. It is possible that the hotter and dryer microhabitat edges are preferred by antlions.  相似文献   
992.
993.
The in vitro determination of the effects of some pharmacological agents on the outer diameter and axial tension of human Fallopian tube ampullar segments showed that some drugs may act on the circular and longitudinal smooth muscle layers relatively separately. PGF2 alpha elicited an excitatory response in both muscle layers while norepinephrine and isoproterenol decreased the activity. Oxytocin and indomethacin had relatively limited effects on the spontaneous motility of the ampullar segments. The calcium antagonist verapamil inhibited the spontaneous periodic activity.  相似文献   
994.
Campylobacter jejuni is an almost ubiquitous, microaerophilic, gram-negative rod. Outbreaks have been associated with drinking raw milk or contaminated water and eating poultry. Campylobacter jejuni accounts for 3.2% to 6.1% of cases of diarrheal illness in the general population of the United States, and infected patients frequently present with abdominal pain and fever. Less frequently, C jejuni is responsible for bacteremia, septic arthritis, septic abortion, and other extraintestinal infections. Reactive arthritis, Reiter''s syndrome, the Guillain-Barré syndrome, and pancreatitis may accompany or follow C jejuni enterocolitis. Campylobacter jejuni is an important cause of diarrheal illness and is a more commonly identified stool organism than Salmonella or Shigella species. Recurrent and chronic infection is generally reported in immunocompromised hosts.  相似文献   
995.
Big, beautiful organisms are useful for biological education, increasing evolution literacy, and biodiversity conservation. But if educators gloss over the ubiquity of streamlined and miniaturized organisms, they unwittingly leave students and the public vulnerable to the idea that the primary evolutionary plot of every metazoan lineage is “progressive” and "favors" complexity. We show that simple, small, and intriguingly repulsive invertebrate animals provide a counterpoint to misconceptions about evolution. Our examples can be immediately deployed in biology courses and outreach. This context emphasizes that chordates are not the pinnacle of evolution. Rather, in the evolution of animals, miniaturization, trait loss, and lack of perfection are at least as frequent as their opposites. Teaching about invertebrate animals in a “tree thinking” context uproots evolution misconceptions (for students and the public alike), provides a mental scaffold for understanding all animals, and helps to cultivate future ambassadors and experts on these little‐known, weird, and fascinating taxa.  相似文献   
996.
A rapid, sensitive method has been developed to detect antibody-antigen complexes on “Western blots.” The methods of H. Towbin, T. Staehlin, and J. Gordon were used to separate and blot the antigens onto nitrocellulose. The remaining sites of attachment were blocked and the nitrocellulose was washed with polyoxyethylenesorbitan monolaurate (Tween 20). The blot was then reacted with the antiserum or hybridoma supernate to be tested. After the antigen-antibody reaction was completed, the blot was washed and treated with anti-antibody which has been conjugated to alkaline phosphatase. The alkaline phosphatase was detected by the reduction of the tetrazolium salt to diformazan by the hydrogen ions released in the formation of indigo by the reaction of the phosphatase on the indoxyl phosphate. The advantages of this method over previously described techniques are (1) use of Tween 20 allows the blot to be stained with Coomassie blue, (2) the substrates of the alkaline phosphatase reaction are stable for long periods of time, (3) the reaction products form an intense blue color which does not fade, (4) the resolution is extremely good with little to no band broadening, (5) the reaction is sensitive to picogram quantities of antigen, and (6) the reaction is quantitative.  相似文献   
997.
998.
999.
C L Rümke 《Blood cells》1985,11(1):137-140
Ratios of two percentages observed in differential counts of leukocytes or lymphocytes are very imprecise if they are based on relatively small numbers of cells. This is shown by the length of the 95% confidence intervals for such ratios. A formula is given for computing the limits of such intervals. They should accompany each observed value for a ratio.  相似文献   
1000.
Antigen inoculated intratracheally (IT) into animals can induce primary immune responses and selectively recruit specific T cells to the lung. In the current study, the role of alveolar macrophages (AM) in these two responses was investigated. Antigen-pulsed bronchoalveolar cells (BAC) inoculated IT into guinea pigs generated a population of immune T cells that proliferated in vitro on reexposure to antigen-pulsed macrophages (M?). The possibility that antigen-pulsed donor BAC shed antigen that was subsequently processed and presented by host M? was ruled out by genetic experiments. Thus, peritoneal exudate lymphocytes (PEL) from (2 X 13)F1 guinea pigs primed with antigen-pulsed BAC from strain 2 animals responded preferentially to antigen-pulsed strain 2 M? rather than to antigen-pulsed strain 13 M?. In a second set of studies, antigen-pulsed BAC inoculated IT into guinea pigs selectively recruited antigen-specific T cells to the lung. Genetic experiments verified that inoculated BAC were the source of the antigen-presenting cells responsible for selective recruitment. Thus, antigen-pulsed strain 2 BAC inoculated IT recruited a greater proportion of (2 X 13)F1 T cells that recognized antigen in the context of strain 2 M? than F1 T cells that recognized antigen on strain 13 M?. Taken together, these studies suggest that AM contribute to the regulation of pulmonary immunity by both inducing T lymphocyte immunity and selectively recruiting specific T cells to the lung.  相似文献   
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