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Studies were conducted to examine under differing temperatures (12, 16, 20, 24, 28, and 32 C) the penetration anti development of Meloidogyne hapla in resistant lines ''298'' and ''Nev. Syn XX'', and susceptible ''Lahontan'' and ''Ranger'' hardy-type alfalfas. The results indicated that resistance to M. hapla was similar to that previously described for M. incognita in nonhardy alfalfa. Although initial penetration in resistant seedlings was similar to that of susceptible seedlings, nematode larvae failed to establish and develop in root tissues and nematode numbers subsequently declined. In susceptible seedlings, nematode development proceeded rapidly, and egg production began after 5 weeks. Temperature had little influence on the nematode development except to slow the response at the lower temperatures. Other studies were conducted to verify a previously reported immune (no penetration) reaction to M. hapla by the ''Vernal'' selection ''M-4''. When compared to the resistant (penetration without nematode development) Vernal selection ''M-9'' under differing temperatures (20, 24, 28, and 32 C), each selection was equally penetrated by M. hapla but at a lower level than in susceptible Ranger cuttings. Generally, no root galling was observed in either M-4 or M-9; however, very slight galling was found 35 days after inoculation on about 50% of these cuttings when grown at 32 C.  相似文献   

3.
OBJECTIVE--To study prevalence of Turner''s syndrome in Denmark and to assess validity of prenatal diagnosis. DESIGN--Study of data on prenatal and postnatal Turner''s syndrome in Danish Cytogenetic Central Register. SUBJECTS--All registered Turner''s syndrome karyotypes (100 prenatal cases and 215 postnatal cases) during 1970-93. MAIN OUTCOME MEASURES--Prevalence of Turner''s syndrome karyotypes among prenatally tested fetuses and Turner''s syndrome among liveborn infants. RESULTS--Among infant girls, prevalence of Turner''s syndrome was 32/100,000. Among female fetuses tested by amniocentesis, prevalence of Turner''s syndrome karyotypes was 176/100,000 (relative risk of syndrome, 6.74 compared with prevalence among untested pregnancies). Among female fetuses tested by chorion villus sampling, prevalence of syndrome karyotypes was 392/100,000 (relative risk, 16.8). We excluded prenatal tests referred because of results of ultrasound scanning: among fetuses tested by amniocentesis revised relative risk was 5.68, while revised relative risk among fetuses tested by chorion villus sampling was 13.3. For 29 fetuses with prenatal diagnosis of possible Turner''s syndrome, pregnancy was allowed to continue and 24 children were live born. Thirteen of these children were karyotyped postnatally, and diagnosis of Turner''s syndrome had to be revised for eight, seven being normal girls and one boy. This gives tentative predictive value of amniocentesis in diagnosing Turner''s syndrome of between 21% and 67%. There was no significant relation between mother''s age and risk of Turner''s syndrome. CONCLUSIONS--Discrepancy between prenatal and postnatal prevalence of Turner''s syndrome challenges specificity of prenatal examination in diagnosing Turner''s syndrome.  相似文献   

4.
Sensitivity and host efficiency of susceptible (''Lee 68'', ''Coker 156'') and resistant (''Bragg'', ''Centennial'', ''Forrest'', ''Lee 74'') soybean (Glycine max (L.) Merr.) cultivars for races of Meloidogyne incognita (Mi) were determined in greenhouse experiments. Eight Mi populations collected from the southeastern United States were utilized. All Mi races reproduced readily on Lee 68 and Lee 74 and moderately on Forrest and Bragg. Coker 156 exhibited resistance to races 1 and 2, and some race 3 populations, but was very susceptible to certain race 3 and 4 populations. Reproduction of all races was lowest on Centennial. Forrest and Centennial shoot growth was not significantly suppressed by any race. There were no distinct differences in virulence between races except for a race 3 population which reproduced readily on all cultivars, stunting their growth. Considerable variation in reproduction existed within races 1 and 3.  相似文献   

5.
In South Africa, a country in which the manipulation of ethnicity was at the heart of the government's attempts to establish control over the majority African population, ethnic mobilization during the liberation struggle was singularly unsuccessful. The one exception was Chief Mangosuthu Buthelezi's controversial Inkatha movement. This article suggests that one of the reasons for Inkatha's successes was the astute way in which the organization and, in particular, Buthelezi played on gendered notions of 'home' and 'homeland'. Historically, apartheid constructed notions of home and space differently for women and men and Inkatha was able to draw upon and manipulate these differences to produce a powerfully felt response. Thus, for men, many of them migrant workers in South Africa's cities, the notion of 'home' implied a return to patriarchal values and male domestic control in a historically constituted 'homeland'; for women, Buthelezi emphasized the new 'modern' opportunities opened up by the KwaZulu homeland, and the importance of their 'God-given' gifts of motherhood.  相似文献   

6.
Pathogenicity tests of Pratylenchus brachyurus on selected greenhouse-grown soybean cultivars indicated the nematode reduced seed yield of ''Hood'' but not that of ''Custer'', ''Bragg'', ''Dyer'', or ''Pickett''. Root weights of all cultivars were reduced. Damage and numbers of nematodes within soybean roots growing at 13, 21, and 29 C were greater at higher temperatures. At 29 C, root pruning was prominent in ''Hood'' and ''Pickett'' but limited in ''Custer'' and ''Hill''. Root pruning was not observed at 13 C and only ''Pickett'' showed pruning at 21 C. Plant height and foliage weight were not affected. P. brachyurus had no effect on the emergence of ''Pickett'' or ''Bragg'' soybeans. Nematode counts from roots of ''Pickett'' at intervals after inoculation indicated that hatching of second generation second-stage larvae occurred about 15 days after egg laying. An average of 68% of the initial inoculum penetrated the roots within five days of inoculation, the highest observed was 81% in five days. Details of structural damage in penetrated tissues were studied in sectioned roots. In soybean roots infected by P. brachyurus and/or Rhizoctonia solani greater damage occurred with nematode and fungus combined than with either acting alone.  相似文献   

7.
In the course of a continuing search for means of predicting Huntington''s chorea before the onset of neurological symptoms, a study of fingerprint patterns was undertaken, using the technique employed by Hodges and Simon in the investigation of patients with Wilson''s disease. Fingerprint patterns of 61 patients with Huntington''s chorea and 50 with Parkinson''s disease were compared with norms established by Scotland Yard. Although an increased incidence of the “whorl” pattern was seen in the left second and third fingers in patients with Huntington''s chorea, this finding could not be interpreted as having diagnostic or prognostic value as it was found also in some normal subjects and in occasional cases of Parkinson''s disease. The pattern supposedly characteristic of Wilson''s disease was also seen in persons with Huntington''s chorea.  相似文献   

8.
Tylenchorhynchus dubius was observed to feed on ''Toronto'' creeping bentgrass and ''Merion'' Kentucky bluegrass, and was a key participant in reducing the vegetative growth of both grass species. The severity of foliar and root macrosymptoms incited by T. dubius to ''Toronto'' bentgrass was greater on plants grown at 16 C than on plants maintained at 21, 27 and 32 C. These parasitized plants exhibited a suppression of secondary stolon formation, shortened internodes and premature inflorescence initiation. Initial inoculum densities of 500 and 1000 nematodes/test pot produced similar pathogenic effects on the host. Feeding was primarily on root hairs and epidermal cells immediately behind the meristematic region. No necrotic lesions or other diagnostic symptoms were visible at the feeding sites. Nematodes were not observed inside the roots.  相似文献   

9.
为比较番石榴(Psidium guajava)不同品种果实的外观、营养价值和香气特征,采用国家标准方法,对5个番石榴品种(‘红宝石’、‘粉红蜜’、‘西瓜’、‘水蜜’、本地种)果实的外观和营养成分进行测定,采用顶空气质联用(HS-GC-MS)技术对5个品种果实的香气成分进行测定。结果表明,不同品种果实外观及营养成分差异明显。‘水蜜’的果形指数最低,果实扁圆形,种籽最少;大多数糖类物质(总糖、还原糖、蔗糖等)、糖酸比、总酚含量最高;果糖、VC和总黄酮含量位居第2;总酸、脂肪、粗纤维、灰分含量最低。主成分分析表明,‘水蜜’作为鲜食水果的食用品质最高。己醛和石竹烯是红肉型品种的特征风味物质,3-羟基-2-丁酮是白肉型品种的特征香气成分。  相似文献   

10.
《Hormones and behavior》2009,55(5):703-708
Many studies have shown that women's judgments of men's attractiveness are affected by changes in levels of sex hormones. However, no studies have tested for associations between changes in levels of sex hormones and men's judgments of women's attractiveness. To investigate this issue, we compared men's attractiveness judgments of feminized and masculinized women's and men's faces in test sessions where salivary testosterone was high and test sessions where salivary testosterone was relatively low. Men reported stronger attraction to femininity in women's faces in test sessions where salivary testosterone was high than in test sessions where salivary testosterone was low. This effect was found to be specific to judgments of opposite-sex faces. The strength of men's reported attraction to femininity in men's faces did not differ between high and low testosterone test sessions, suggesting that the effect of testosterone that we observed for judgments of women's faces was not due to a general response bias. Collectively, these findings suggest that changes in testosterone levels contribute to the strength of men's reported attraction to femininity in women's faces and complement previous findings showing that testosterone modulates men's interest in sexual stimuli.  相似文献   

11.
Penetration, development, and reproduction of a virulent ''Harmony'' population of Meloidogyne arenaria was studied on two nematode-resistant grape rootstocks 10-17A and 6-19B. ''Cabernet Sauvignon'' was used as a susceptible control for comparison. Plants were inoculated with 100 freshly hatched second-stage juveniles (J2) of M. arenaria. Greater numbers of J2 penetrated roots of ''Cabernet'' than 10-17A, and none penetrated roots of 6-19B 4 days after inoculation (DAI). At 7 DAI, vermiform J2 advanced to sausage-shaped J2 in roots of ''Cabernet,'' penetrated roots of 6-19B, and had egressed from roots of 10-17A. Resistant rootstocks expressed hypersensitive responses to penetrating J2 along the root epidermis, among the cortical cells, and along the differentiating vascular bundles. At 13 DAI, 68% of the J2 had attained globose stage in roots of ''Cabernet,'' whereas there was no development of vermiform J2 in roots of the other two rootstocks. The nematodes reproduced only in roots of ''Cabernet.'' Lack of development of J2 in roots of the two resistant grape rootstocks might be the result of a hypersensitive response to J2 feeding.  相似文献   

12.
The β-glucans derived from yeast cell walls have been reported for having many immunomodulatory activities in vivo and in vitro. In this study, Aureobasidium-derived soluble branched (1,3-1,6) β-glucan (Sophy β-glucan) was checked for natural killer (NK) activity and for the production of IFN-γ and IL-4 in Leishmania amazonensis infection. The main experiment was performed with a group of female C57BL/6 and BALB/c mice, orally supplemented with 5% of Sophy β-glucan and infected with promastogotes of L. amazonensis (1 × 107) into the footpad. Increase in the footpad thickness with time was observed in BALB/c mice in spite of the oral Sophy β-glucan supplement, but it was less in C57BL/6 mice. The difference in overall mean footpad thickness between ''infection only'' versus ''infection + glucan'' groups was statistically significant (P < 0.001). High NK activity in C57BL/6 than BALB/c mice was observed in ''glucan only'' group compared to the control group and also in ''infection + glucan'' group compared to ''infection only'' group. The difference in the NK activity among these groups was significant (P < 0.05). The IFN-γ level increased at weeks 7 and 8 post-infection in C57BL/6 mice and was significantly high in ''infection + glucan'' group compared to the ''infection only'' group (P < 0.05). IL-4 levels did not increase up to detectable levels throughout the study. The results led a conclusion that Sophy β-glucan enhances NK activity and cellular immunity in L. amazonensis-infected mice.  相似文献   

13.
The concentration of substrate expressed as hypoxanthine capable of reacting with xanthine oxidase to release superoxide free radicals (O2-) was measured in control and Dupuytren''s contracture palmar fascia. In Dupuytren''s contracture palmar fascia the concentration of hypoxanthine was six times that of control and was greatest in "nodular" areas. Xanthine oxidase activity was also detected in Dupuytren''s contracture palmar fascia. These results suggest a greater potential for hypoxanthine-xanthine oxidase generated oxygen free radical formation in Dupuytren''s contracture than in control palmar fascia. Production of free radicals may be an important factor in the pathogenesis of Dupuytren''s contracture. The benefit of allopurinol in the management of Dupuytren''s contracture and other fibrotic conditions may thus be explained, as allopurinol binds to xanthine oxidase and prevents release of free radicals.  相似文献   

14.
Eleven soybean [Glycine max (L.) Merr.] cultivars resistant to one or more plant-parasitic nematodes, and one resistant to the Mexican bean beetle (Epilachna varivestis Muls.), were tested for susceptibility to Hoplolaimus columbus. All cultivars were parasitized, but nematode reproduction varied. ''Pickett-71'' was the most susceptible host among the cultivars tested. ''Dyer'' and three ''P.I. cultivars'' were most tolerant when yield /plant and total yield were compared for fumigated and unfumigated plots, even though their yield potential was low. ''Hardee,'' ''Coker 4504,'' ''W-4,'' ''D71-9257,'' and ''ED-371'' appeared tolerant throughout the growing season and yielded well in unfumigated soil. Infection and reproduction of H. columbus in ''Forrest'' soybean roots were greater at 30 ± 1 C than at 20 or 25 ± 1 C. Plant height and root weight varied with the soil treatments.  相似文献   

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16.
Using a double beam stopped-flow apparatus, measurements were made of the velocity constant of the reaction CO + Hb → COHb in solution and in the red cells of human beings, rabbits, horses, and goats. The solution constant (l'') at 37°C for human beings was 362 mM -1 sec.-1; in other species l'' was somewhat lower. Two rabbits, despite having apparently identical hemoglobins had significantly different values for l''. The energy of activation (E) of l'' was between 8 and 11 kcal/mole in all cases. The cell reaction constant (l''c) at 37° was between 61 and 73 mM -1 sec.-1 in all cases; at 37° the trend was for the smaller cells to have the higher l''c. This cell size effect was much less than previously found for the faster oxygen reaction. This showed that by merely increasing the rate of chemical reaction, it was not possible to increase cell uptake rate beyond a certain level, this level being dependent on the size and membrane properties of the cell. At lower temperatures l'' was a more important factor in determining l''c than was cell size. The cell membrane was a barrier to gas diffusion in all species. The effect of temperature on l''c was also measured and was less than its effect on l'' at most temperatures. Temperature effect increased in small cells at low temperatures. Both these findings are in accordance with predictions based on differentiation of Roughton''s equations.  相似文献   

17.
Meloidogyne chitwoodi reduced the growth of winter wheat ''Nugaines'' directly in relation to nematode density in the greenhouse, The relationship between top dry weight and initial nematode density suggests a tolerance limit of Nugaines wheat to M. chitwoodi of between 0.03 and 0.18 eggs/cm³ of soil; the value for relative minimum plant top weight was 0.45 g and 0.75 g, respectively. Growth of wheat in field microplots containing four population densities (0.003, 0.05, 0.75 and 9 eggs/cm³ soil) was not affected significantly at any inoculum level compared to controls during September to July, However, suppression of head weights of ''Fielder'' spring wheat grown May-July occurred in microplots initially infested with 0.75 and 9 eggs/cm³ soil. Reproduction (Pf/Pi) was poorer at these two inoculum levels as compared to the lower densities. In another greenhouse experiment, roots of wheat cultivars Fielder, ''Fieldwin,'' ''Gaines,'' ''Hyslop,'' and Nugaines became infected by M. chitwoodi, but not by M. hapla. Reproduction of M. chitwoodi was less on Gaines and Nugaines than on Fielder, Fieldwin, or Hyslop.  相似文献   

18.
A study of respiratory symptoms in 2,426 schoolchildren aged 6-14 years was carried out in Aylesbury, Buckinghamshire, in 1971. The prevalence of cough in the children was associated with the parents'' smoking habits; prevalence was lowest where both parents were non-smokers, highest where both parents smoked, and lay between these two levels where only one parent smoked. A close association was found between parents'' and children''s respiratory symptoms that was independent of parents'' smoking habits. There was no suggestion that exposure to the cigarette smoke generated when parents smoked had any more than a small effect upon the child''s respiratory symptoms. While the sharing of genetic susceptibility between parents and children is a factor, therefore, cross infection, particularly in the families where parents smoke, is an important element in the association.  相似文献   

19.
AMP deaminase isoforms from human skeletal muscle can be separated chromatographically [Kaletha, Spychała & Nowak (1987) Experientia 43, 440-443]. In adult tissue nearly all the AMP deaminase activity was eluted from phosphocellulose with 0.75 M-KCl (''adult'' isoform), and the remaining activity could be eluted with 2.0 M-KCl. Conversely, most of the AMP deaminase activity from 11-week-old fetal tissue was eluted from phosphocellulose with 2.0 M-KCl (''fetal'' isoform). In the present paper the kinetic and regulatory properties of AMP deaminase extracted from 11- and 16-week-old fetal skeletal muscle are reported. The two isoforms from 11-week-old human fetus differed distinctly in these properties. The ''fetal'' isoform had about 5-fold higher half-saturation constant (S0.5) value than the ''adult'' form. It was also more sensitive to the influence of some important regulatory ligands (ADP, ATP and Pi), and exhibited a different pH/activity profile. The ''adult'' isoform of AMP deaminase from fetal muscle and the enzyme from mature muscle possessed similar kinetic and regulatory properties. This isoform seems not to be subject to any major modifications during further ontogenesis. This is not true, however, for the ''fetal'' isoform. In the muscle of 16-week-old human fetus, the ''fetal'' isoform showed a peculiar, biphasic, type of substrate-saturation kinetics. This phenomenon may reflect appearance of the next, developmentally programmed, isoform of human skeletal-muscle AMP deaminase.  相似文献   

20.
Penetration, rate of development, and total population of Meloidogyne incognita in roots of susceptible ''Allgold'' and resistant ''Nemagold'' sweet potatoes increased with temperature 24-32 C. Rate of larval penetration in ''Allgold'' was significantly higher than in ''Nemagold'' after 48 hr of root exposure at 24, 28, and 32 C. At 24, 28, and 32 C (16 hr) day and 20 C (8 hr) night temperature the life cycle of M. incognita required 42, 32, and 28 days in ''Allgold'', and 44, 33, and 31 days in ''Nemagold''; mature females in the first generation were 40, 40, 40, and 10, 22, 20 respectively. The correlation between the length of time roots were allowed to grow in the soil prior to inoculation and number of larvae recovered from the roots after inoculation was positive for ''Allgold'' and negative for ''Nemagold''. Therefore, a root exudate repellent to M. incognita larvae is proposed as a hypothetical basis for resistance to M. incognita in sweet potatoes.  相似文献   

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