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1.
The phylogeny of the fungus gnat family Mycetophilidae (Diptera) is reconstructed with a focus on the species‐rich and taxonomically difficult subfamilies Gnoristinae and Mycomyinae. The multigene phylogenetic analyses are based on five nuclear (18S, 28S, CAD, MCS, ITS2) and four mitochondrial (12S, 16S, COI, CytB) gene markers. The analyses strongly support the monophyly of Mycetophilidae and the subfamilies Manotinae, Sciophilinae, Leiinae, and Mycomyinae, although Gnoristinae is paraphyletic with respect to Mycetophilinae. All the genera and groups of genera included are supported as monophyletic, except for Acomoptera Vockeroth, Boletina Staeger, Dziedzickia Johannsen, Ectrepesthoneura Enderlein, and Neoempheria Osten Sacken. Ancestral character state reconstructions were applied to two morphological features present in Gnoristinae and Mycomyinae (i.e. presence of setae on wing membrane and wing vein R4) in order to assess their evolution. The wing vein R4 appears as an unstable character, spread throughout different clades. A dated phylogeny of the family Mycetophilidae showed that most of the subfamilies of Mycetophilidae originated and diversified during the Cretaceous. The youngest subfamilies, originated in the Paleogene, appear to be Mycomyinae and Mycetophilinae.  相似文献   
2.
The author describes changes in the disintegration of erythrocytes by brilliant cresyl blue in correlation to age, in rats aged 21, 42, 90-105, 340-360 and 690-720 days. The erythrocytes were incubated for 4 hours in an isotonic NaCl solution, in Krebs-Ringer solution and in each of these solutions plus brilliant cresyl blue. Disintegration in plain NaCl solution was found to be the greatest in the case of erythrocytes from 690- to 720-day-old rats. In the same solution plus brilliant cresyl blue, the rate of disintegration was very high in 21-day-old, 42-day-old and 690- to 720-day-old animals; at 90-105 days it was lower and at 340-360 days it was the lowest. Disintegration of erythrocytes in plain Krebs-Ringer solution was the lowest at 21 and 42 days; in the other age groups it was slightly higher. On adding brilliant cresyl blue, the rate of disintegration rose significantly in 21-, 42- and 690- to 720-day-old animals; at 90-105 days and 340-360 days it was no different from disintegration in plain Krebs-Ringer solution. It can be seen from the results that the rate of brilliant cresyl blue-induced erythrocyte disintegration is dependent on the age of the animals from which the erythrocytes are taken.  相似文献   
3.
Temperature-sensitive (ts) mutations of the G101 phage were isolated after mutagenesis with hydroxylamine. A complementation analysis of 61ts mutants showed that these mutants may be divided into at least 12 complementation groups. Twots mutants probably originated in genes which control lytic functions of the G101 phage. It was shown by three factor crosses that all of the 12ts mutations tested are localized on that side of the “c” region where the probablecI repressor gene is positioned. Sevents mutations is closely linked to thecI 26 clear marker, three exhibit a closer linkage and two do not exhibit any linkage withcI. All mutations isolated until now can be arrange linearly. According to the present knowledge the preliminary genetic map of the G101 phage is linear.  相似文献   
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Cell nuclei have been released from various plant tissues (barley leaves, roots and embryos, tobacco leaves and tissue cultures,Vicia faba roots,Arabidopsis thaliana leaves) by several homogenization methods and the optimal method was established for each tissue. The effect of the composition of isolation medium on the yield and appearance of isolated nuclei was also studied. Longer incubation withn-octanol increases the yield considerably in most cases. Low concentrations of osmoticum increase the yield and their adverse effect on the integrity of nuclei is of little significance. Gum arabic has a favourable effect on nuclei isolation from roots only.  相似文献   
6.
In male Wistar rats, the inhalation exposure to acrylonitrile (AN), 271 mg X m-3, 8 hours a day, 5 days a week, did not affect protein sulfhydryl concentration in liver and blood and decreased glutathione concentration in the liver, but not in the brain at the end of the fifth exposure. The urinary excretion of the main AN metabolites, thioethers (AN-mercapturic acids) and thiocyanate was proportional to the inhaled AN concentration (57, 125, 271 mg X m-3, respectively) in a single exposure for 12 hours, and their mutual ratio was greatly different from that after injection of AN. The results revealed that the urinary excretion of thioethers is a very sensitive and dose-related indicator of exposure to AN and extrapolation of the results indicates that the exposure to AN concentration below 10 mg X m-3 could thus be demonstrated.  相似文献   
7.
The association between the red macroalga Jania adhaerens J. V. Lamour. and the sponge Haliclona caerulea is the most successful life‐form between 2 and 4 m depth in Mazatlán Bay (Mexican Pacific). J. adhaerens colonizes the rocky intertidal area and penetrates into deeper areas only when it lives in association with H. caerulea. The aposymbiotic form of the sponge has not been reported in the bay. To understand the ecological success of this association, we examined the capacity of J. adhaerens to acclimate in Mazatlán Bay using transplant experiments. The transplanted aposymbiotic J. adhaerens did not survive the first 2 weeks; however, J. adhaerens when living in association with H. caerulea, acclimated easily to depth, showing no sign of mortality during the 103 d of the experiment. We conclude that the ability of J. adhaerens to colonize in deeper areas in this hydrodynamic environment may in part rely on the protection provided by the sponge to the algal canopy. Both species contribute to the shape of the associated form. Nevertheless, the morphological variation in the association appears to be dominated by the variation in J. adhaerens canopy to regulate pigment self‐shading under light‐limited conditions and/or tissue resistance under high hydrodynamics. Consequently, our results are consistent with light as the abiotic controlling factor, which regulates the lower depth distribution of the association in Mazatlán Bay, through limiting the growth rate of J. adhaerens. Hydrodynamics may determine the upper limit of the association by imposing high mass losses.  相似文献   
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These siblings of a Czech family aged 21, 19 and 6 years, respectively, with congenital dyserythropoietic anemia, type II, (HEMPAS) are reported. In two elder siblings ferrokinetic studies revealed a rapid plasma 59Fe clearance, markedly decreased erythrocyte incorporation and shortened 51Cr red-cell survival. Direct anti-globulin test was found positive in one of them. Further investigations revealed low values of blood plasma cholesterol, total lipids, beta-lipoproteins, beta-carotine and vitamin E and A as well as low values of the prothrombin complex. Liver biopsy demonstrated siderosis and disseminated intravascular coagulation in the liver in both patients. The possible reasons for these humoral aberrations are discussed.  相似文献   
10.
Changes in the duration and size of the vulnerable period of the myocardium in the presence of respiratory changes were studied in acute experiments on rats. The limits of the vulnerable period were determined by directly stimulating the heart during ventilation via the enlarged respiratory dead space, during hyperventilation and during heart failure. In the control group (normal ventilation without enlargement of the dead space), the vulnerable period lasted 5.7 +/- 0.76 ms. During ventilation via the enlarged dead space, hypercapnic hypoxaemia developed and the vulnerable period was markedly prolonged (18.55 +/- 5.29 ms) by a shift of its inner limit to the left. Hyperventilation caused normoxic to hyperoxic hypocapnia and markedly reduced the duration of the vulnerable period (8.17 +/- 2.21 and 9.31 +/- 2.38 ms respectively). The vulnerable period lengthened the most in heart failure (25.46 +/- 3.93), mainly as a result of a shift of its outer limit. In all the experimental groups there was a shift of the vulnerable period to the right, which was fastest in hypercapnic hypoxaemia and slowest in hyperoxic hypocapnia. The administration of Inderal (3 mg/kg i.p.) or Arfonad (50 mg/kg i.p.) markedly shortened the vulnerable period during hypercapnic hypoxaemia (9.87 +/- 2.78 and 9.32 +/- 2.16 ms respectively), but did not block the shift. Lengthening of the vulnerable period during hypercapnic hypoxaemia was probably due to activation of sympathetic nerves via beta-adrenergic receptors.  相似文献   
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