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1.
Phillip A. Morin 《Conservation Genetics》2000,1(3):271-275
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Role of different lymphoid tissues in the initiation and maintenance of DNA-raised antibody responses to the influenza virus H1 glycoprotein.
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Antibody responses in mice immunized by a single gene gun inoculation of plasmid expressing the influenza virus H1 hemagglutinin and in mice immunized by a sublethal H1 influenza virus infection have been compared. Both immunizations raised long-lived serum responses that were associated with the localization of antibody-secreting cells (ASC) to the bone marrow. However, the kinetics of these responses were 4 to 8 weeks slower in the DNA-immunized than in the infection-primed mice. Following a gene gun booster, the presence of ASC in the inguinal lymph nodes, but not in other lymph nodes, revealed gene gun responses being initiated in the nodes that drain the skin target site. Both pre- and postchallenge, the DNA-immunized mice had 5- to 10-times-lower levels of antibody and ASC than the infection-primed mice. 相似文献
4.
Steven I. Higgins Robert B. O’Hara Olga Bykova Michael D. Cramer Isabelle Chuine Eva‐Maria Gerstner Thomas Hickler Xavier Morin Michael R. Kearney Guy F. Midgley Simon Scheiter 《Journal of Biogeography》2012,39(12):2132-2145
Aim To develop a physiologically based model of the plant niche for use in species distribution modelling. Location Europe. Methods We link the Thornley transport resistance (TTR) model with functions which describe how the TTR’s model parameters are influenced by abiotic environmental factors. The TTR model considers how carbon and nutrient uptake, and the allocation of these assimilates, influence growth. We use indirect statistical methods to estimate the model parameters from a high resolution data set on tree distribution for 22 European tree species. Results We infer, from distribution data and abiotic forcing data, the physiological niche dimensions of 22 European tree species. We found that the model fits were reasonable (AUC: 0.79–0.964). The projected distributions were characterized by a false positive rate of 0.19 and a false negative rate 0.12. The fitted models are used to generate projections of the environmental factors that limit the range boundaries of the study species. Main conclusions We show that physiological models can be used to derive physiological niche dimensions from species distribution data. Future work should focus on including prior information on physiological rates into the parameter estimation process. Application of the TTR model to species distribution modelling suggests new avenues for establishing explicit links between distribution and physiology, and for generating hypotheses about how ecophysiological processes influence the distribution of plants. 相似文献
5.
A hand-reared raccoon (Procyon lotor) kit had severe diarrhea and died within 24 hr. Gross and histopathologic findings were compatible with a diagnosis of viral enteritis. The immunoperoxidase test revealed rotavirus group A antigen in the intestinal mucosa. This is the first record of rotaviral enteritis in a raccoon. 相似文献
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W E Stumpf J K Morin B W Ennis J E Zielinski R B Hochberg 《The journal of histochemistry and cytochemistry》1987,35(1):87-92
We demonstrate the utility of [16 alpha-125I]iodoestradiol for thaw-mount autoradiography with 2 micron and 4 micron thick sections of rat and mouse uterus, pituitary, and brain after in vivo administration. Under the conditions of the experiments, short-term autoradiography with exposure times between 3 and 14 days provides optimal cellular resolution, whereas long-term autoradiography with 1-2 months of exposure may be used to obtain topographic-regional surveys of distribution. 相似文献
8.
To utilize specific fetal markers in amniotic fluid for prenatal detection of fetal anomalies, it is necessary to determine the precise tissue origin of these markers. In rabbit fetuses, we distinguished between intestinal and renal forms of trehalase (alpha,alpha'-trehalose-1-D-glucohydrolase, EC 3.2.1.28) in amniotic fluid on the basis of differences in net electric charges. Trehalase was solubilized from purified brush-border membranes of fetal rabbit kidney and intestine by Triton X-100 treatment, whereas the trehalase activity in amniotic fluid was soluble. The kinetic properties of trehalase from intestine, kidney and amniotic fluid were very similar. The Mr of the soluble amniotic fluid trehalase was between 72,600 and 66,300 from hydrodynamic parameters, depending on the amount of sugar bound to the enzyme, and 48,500 by radiation inactivation, a method which detects only the protein part of the enzyme. For membrane-bound trehalase from kidney and intestine in situ the radiation inactivation method also gave a molecular size of around 49,000. Isoelectric focusing of freshly solubilized membranes allowed us to distinguish between renal and intestinal forms of trehalase in rabbit fetuses on the basis of different isoelectric points. Each trehalase form was also present in the amniotic fluid but in varying proportions depending on the gestational age at which the amniotic fluid was collected. The results suggest that early in gestation amniotic fluid trehalase activity originates exclusively from the fetal kidney but that more and more intestinal enzyme is released into the amniotic cavity as the fetus develops. Similar results were also obtained when ion-exchange chromatography was used to separate the various trehalase forms. The development of trehalase activity in rabbit fetal kidney and intestine correlates well with its occurrence in the amniotic fluid; trehalase activity in the kidney develops early in gestation whereas the intestinal trehalase activity develops just before term. 相似文献
9.
Microbiological Degradation of Malodorous Substances of Swine Waste under Aerobic Conditions 总被引:2,自引:1,他引:1
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Denis Bourque Jean-Guy Bisaillon Rjean Beaudet M. Sylvestre Muhammad Ishaque Andr Morin 《Applied microbiology》1987,53(1):137-141
Phenol, p-cresol, and volatile fatty acids (VFA; acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids) were used as odor indicators of swine waste. Aeration of the waste allowed the indigenous microorganisms to grow and degrade these malodorous substances. The time required for degradation of these substances varied according to the waste used, and it was not necessarily related to their concentrations. Using a minimal medium which contained one of the malodorous compounds as sole carbon source, we have selected from swine waste microorganisms that can grow in the medium. The majority of these microorganisms were able to degrade the same substrate when inoculated in sterilized swine waste but with an efficiency varying from one strain to the other. None of these strains was able to degrade all malodorous substances studied. Within 6 days of incubation these selected strains degraded the following: Acinetobacter calcoaceticus, phenol and all VFA; Alcaligenes faecalis, p-cresol and all VFA; Corynebacterium glutamicum and Micrococcus sp., phenol, p-cresol, and acetic and propionic acids; Arthrobacter flavescens, all VFA. On a laboratory scale, the massive inoculation of swine waste with C. glutamicum or Micrococcus sp. accelerated degradation of the malodorous substances. However, this effect was not observed with all of the various swine wastes tested. These results suggest that an efficient deodorization process of various swine wastes could be developed at the farm level based on the aerobic indigenous microflora of each waste. 相似文献
10.
In the mammalian fetus the ductus arteriosus allows right ventricular output to be shunted away from the lungs to the systemic circulation. This study was performed to determine how closing the ductus arteriosus of the fetal sheep would affect the pulmonary circulation. Under halothane anaesthesia 6 near-term fetal sheep were delivered with the umbilical circulation intact. Catheters were placed in the right atrium, the pulmonary artery, and the aorta. Pulmonary blood flow was measured by injecting radioactive microspheres into the right atrium while a reference sample was withdrawn from the pulmonary artery. Closing the ductus arteriosus increased pulmonary arterial pressure by 22% from 51 +/- 3 to 62 +/- 3 mmHg and increased pulmonary blood flow disproportionately by 198% from 232 +/- 74 to 692 +/- 80 ml/min per 100g. Thus, pulmonary vascular resistance decreased by 75% from 0.451 +/- 0.65 to 0.095 +/- 0.010 mmHg 100g min/ml. These findings extend the observation that pressure and flow in the pulmonary circulation of the air-breathing lung do not have a linear relationship passing through the origin to include a striking example in the fluid-filled lung of the intact fetus. They also raise questions about the nature of the elevated vascular resistance in the fetal lung. 相似文献