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131.
Sini Skippari Timo Olavi Veteli John Kasenene Pekka Niemelä Heikki Roininen 《African Journal of Ecology》2009,47(4):537-545
We studied variation in the assemblage of lepidopteran larvae between individual trees, and temporal variation in the diversity and species composition of the assemblage in a medium‐altitude rainforest in Kibale National Park, Uganda. Monthly samples of lepidopteran larvae were collected from the leaves of Neoboutonia macrocalyx Pax. between January 1995 and December 1996. During this period, a total of 1961 specimens representing 76 lepidopteran morphospecies were found. The numbers of individuals within species varied enormously, ranging from one to 707 individuals. Assemblages of individual trees were highly similar and dominated by geometrid larvae. Temporal variation in herbivore abundance was high. The number of individuals peaked during the major rainy season in 1995 but not in 1996 and was not correlated significantly with rainfall within these 2 years. In contrast, a negative correlation was found between lepidopteran diversity and rainfall that seems to cause a semi‐annual trend in diversity with one or two peaks per year. Furthermore, there was seasonality in the similarity of the assemblage. Consequently, the same species were found in the assemblage during certain times of the year. Our study shows that short‐term biodiversity assessments can give a skewed picture of the diversity of tropical forests. 相似文献
132.
Voznesenskaya Elena V.; Artyusheva Elena G.; Franceschi Vincent R.; Pyankov Vladimir I.; Kiirats Olavi; Ku Maurice S.B.; Edwards Gerald E. 《Annals of botany》2001,88(3):337-348
Salsola arbusculiformis is identified as a C3C4intermediatespecies based on anatomical, biochemical and physiological characteristics.This is the first report of a naturally occurring intermediatespecies in the Chenopodiaceae, the family with the largest numberof C4species amongst the dicots. In the genus Salsola, mostspecies have Salsoloid anatomy with Kranz type bundle sheathcells and C4photosynthesis, while a few species have Sympegmoidanatomy and were found to have non-Kranz type bundle sheathcells and C3photosynthesis. In the cylindrical leaves of C4Salsolawith Salsoloid type anatomy, there is a continuous layer ofdistinct, chlorenchymatous Kranz type bundle sheath cells surroundedby a single layer of mesophyll cells; whereas species with Sympegmoidtype anatomy have an indistinct bundle sheath with few chloroplastsand multiple layers of chlorenchymatous mesophyll cells. However,S. arbusculiformis has intermediate anatomical features. Whileit has two-to-three layers of mesophyll cells, characteristicof Sympegmoid anatomy, it has distinctive, Kranz-like bundlesheath cells with numerous chloroplasts and mitochondria. Measurementsof its CO2compensation point and CO2response of photosynthesisshow S. arbusculiformis functions as an intermediate specieswith reduced levels of photorespiration. The primary means ofreducing photorespiration is suggested to be by refixing photorespiredCO2in bundle sheath cells, since analysis of photosyntheticenzymes (activity and immunolocalization) and14CO2labellingof initial fixation products suggests minimal operation of aC4cycle. Copyright 2001 Annals of Botany Company Immunolocalization, photosynthetic enzymes, C3C4intermediate, C4-plants, leaf anatomy, Chenopodiaceae, Salsola arbusculiformis 相似文献
133.
Pasi Miettinen Olavi Luukkanen Stig Johansson Eva Eklund Jackson Mulatya 《Plant and Soil》1988,112(2):233-238
The field phase of the present study was carried out at Bura, eastern Kenya. The introduced, drought resistantProsopis juliflora seedlings were watered at four different irrigation levels. 43 sample trees with 1772 root nodules were dug up and investigated. Several trees lacked viable root nodules especially in nonirrigated plots. Regression analysis indicated significant negative correlation between the mortality of the root nodules and the level of irrigation. Rhizobium strains, which were isolated from the sample trees, were capable of nodulating indigenousAcacia senegal. 相似文献
134.
Effects of exogenous gibberellins GA53 , GA44 , GA19 , GA20 and GA1 on photoperiodically controlled shoot elongation in seedlings of Salix pentandra L. were studied. Gibberellins GA20 and GA1 induced shoot elongation under short days (SD) and could substitute for a transfer to long day (LD), while gibberellins A53 , A44 and A19 were inactive. In seedlings exposed to a prolonged SD-treatment (30 days) there was a significant positive interaction between a transfer to LD and a treatment with GA20 and GA1 on shoot elongation. In addition, GA19 enhanced the growth promotive effect of LD in these seedlings. The results are compatible with the suggestion that conversion of GA19 to GA20 is blocked under SD. This effect is supposed to be an early process leading to the cessation of shoot elongation under SD. Responsiveness of the seedlings to LD and to a GA-treatment gradually decreased with an increasing length of exposure to SD. 相似文献
135.
Summary Sympathetic chain ganglia of newborn rats were cultured in Rose chambers with or without hydrocortisone. After one week, the cultures were examined by light microscopy for formaldehyde-induced catecholamine fluorescence and by electron microscopy after fixation in 5% glutaraldehyde solution and thereafter in 1% osmium tetroxide. Hydrocortisone (10 mg/l) caused a great increase in the number of the small, intensely fluorescent (SIF) cells in the ganglion explants, and the fluorescence intensity of these cells was also increased. The SIF cells corresponded to small, granule-containing (SGC) cells in the electronmicros copic preparations, and in addition to an increase in their number there was also an increase in the size and number of granular vesicles in the presence of hydrocortisone. In control cultures the granular vesicles were round (about 100 nm in diameter) or elongated (40–150 nm in cross section and 150–250 nm in length); both types of vesicles contained electron dense cores. In hydrocortisone-containing cultures round granular vesicles up to 200 nm in diameter were also observed; the cores of these vesicles were of variable electron density. It is concluded that in tissue culture, hydrocortisone causes an increased formation of catecholamine-containing granular vesicles in SIF-SGC cells and their precursors and an increase in the number of these cells.This work was supported by grants from the National Heart Foundation, the Australian Research Grants Committee and the Sigrid Juselius Foundation.University of Melbourne Senior Research Fellow, September, 1971 – August, 1972; present address: Department of Anatomy, University of Helsinki, Siltavuorenpenger, Helsinki, Finland, 00170.Holder of a grant from the National Health and Medical Research Council of Australia.Sunshine Foundation and Rowden White Research Fellow in the University of Melbourne, September, 1971 – August, 1972; present address: Department of Anatomy, University of Helsinki, Siltavuorenpenger, Helsinki, Finland, 00170. 相似文献
136.
137.
Antti Kauppila Jukka Puolakka Olavi Ylikorkala 《Prostaglandins & other lipid mediators》1979,18(4):647-653
The prostaglandin biosynthesis inhibitors ketoprofen and indomethacin were compared in the treatment of primary dysmenorrhea in a double-blind, cross-over trial involving 23 patients. Each drug was used for 2–4 days during 3 consecutive menstruations in randomized order. Good or moderate overall relief was obtained in 60 of the 68 ketoprofen-treated menstruations (88 %) and in 60 of the indomethacin-treated cases (90 %). A dysmenorrhea score, based on subjective estimations of 8 symptoms, similarly decreased from a mean (±S.E.M.) basal level of 9.6 ± 0.6 to 3.6 ± 0.3 during ketoprofen treatment and to 4.0 ± 0.3 during indomethacin. Both drugs relieved pelvic and lower back pains and eliminated vomiting and diarrhea in 82–97 % of the cycles whereas headache, fatigue and nervousness were less frequently alleviated (40–67 %). Eighteen of the 23 women (78 %) had been unable to work during the first day of menstruation, the rate of working days lost was reduced to 4 % with ketoprofen and 9 with indomethacin. Mild side-effects occurred during 12 ketoprofen and 14 indomethacin therapies. Ketoprofen thus seems to be as effective and tolerable as indomethacin in the treatment of primary dysmenorrhea. 相似文献
138.
Lasse Viinikka Pentti Krkl Risto Pokela Olavi Ylikorkala 《Prostaglandins & other lipid mediators》1981,21(5):821-826
Six patients with advanced arteriosclerosis obliterans in the lower extremities were subjected to an exercise test on a tread mill with and without dipyridamole treatment. Prostacyclin (PGI2) release was measured by the concentration of its stable metabolite, 6-keto prostaglandin F1α in plasma. All the patients suffered from ischemic pain during both tests, but no changes were seen in plasma 6-keto-PGF1α. Dipyridamole did not affect the physical performance. Our results suggest that atherosclerotic vessels do not increase PGI2 production in response to ischemia and that a single dose of dipyridamole does not change PGI2 production. 相似文献
139.
A radioimmunoassay for thromboxane B2 (TxB2), a stable metabolite of thromboxane A2, is described. The method consists of extraction of TxB2 into ethyl acetate from acidified plasma or serum samples and saturation analysis using specific antibodies produced in rabbits against TxB2-BSA conjugate. The 50 % displacement level of the standard curve was 19.1 ± 2.9 pg/tube (mean ± S.D., n = 19). The method blank was 3.4 ± 3.1 pg/ml (n = 15) and the assay sensitivity thus 9.6 pg/ml (mean blank + 2 S.D.). When 100 to 200 pg of TxB2 were added to plasma, 96.2–103.6 % were recovered. The intra-assay coefficient of variation varied from 6.7 to 9.7 %, and the inter-assay coefficient of variation was 18.6 % (n = 10). The TxB2 concentration in the plasma of 14 healthy subjects varied from 29.3 to 120.8 pg/ml with a mean ± S.D. of 70.1 ± 26.1 pg/ml, when the blood was collected into tubes containing acetylsalicylic acid (ASA), whereas significantly higher (p < 0.001) TxB2 concentrations of 68.3 – 285.3 pg/ml with a mean ± S.D. of 151.8 ± 66.6 pg/ml were obtained from the same subjects in the plasma of blood which was collected into tubes containing no ASA. When blood samples from 10 subjects were allowed to clot at 0, +24 or +37°C for 60 min., the TxB2 concentrations in the sera were 2053 ± 870 pg/ml, 4001 ± 1370 pg/ml and 178557 ± 54000 pg/ml, respectively. The TxB2 levels in sera which were separated from blood samples incubated at +37°C, correlated significantly (p < 0.001) with the TxB2 productions in platelet-rich-plasma (PRP) after an induced aggregation. Our results indicate 1) when TxB2 is measured in plasma, the use of prostaglandin synthesis inhibitor in the collection tubes is necessary and 2) the measurement of TxB2 in serum of blood which has been kept at +37°C for a strictly standardized period of time could replace the use of PRP in TxB2 studies. 相似文献
140.
Merja B. Marttunen Seppo Pyrhnen Aila E. Tiitinen Lasse U. Viinikka Olavi Ylikorkala 《Prostaglandins & other lipid mediators》1996,52(4):317-326
To explore the mechanism(s) by which antiestrogens may protect against the development of cardiovascular disorders, we measured the production of vasodilatory, antiaggregatory prostacyclin (PGI2 and that of vasoconstrictive, proaggregatory thromboxane A2 (TxA2) before and after 6 months' use of antiestrogens in postmenopausal patients after operation for stage II breast cancer (n = 38). Urine samples were assayed by high performance liquid chromatography and radioimmunoassays for 2,3-dinor-6-ketoprostaglandin F1α (=metabolite of PGI2, dinor-6-keto) and for 2,3-dinor-thromboxane B2 (=metabolite of TxA2, dinor-TxB2). In addition, in 35 of these 38 patients we assayed the capacity of platelets to produce thromboxane A2 during standardized blood clotting. The 4 patients using low-dose aspirin had low thromboxane production, and were excluded from further analysis of the data. An antiestrogen regimen consisting either of tamoxifen (n = 15) or of toremifene (n = 19) caused no changes in production of PGI2 or TxA2, or in their ratio, and in this regard, these antiestrogens behaved similarly. Hypertensive patients (n = 7) using different antihypertensive agents were characterized by reduced urinary out-put of dinor-6-keto (18.5 ± 6.1 vs 35.5 ± 18.5 ng/mmol, mean ± SD, p < 0.05) and reduced platelet capacity to produce TxA2 (62.6 ± 67.8 vs 134.6 ± 75.6 ng/mL, p < 0.05). The patients (n = 15) who had used estrogen replacement therapy (ERT) up until diagnosis of breast cancer showed reduced dinor-TxB2 excretion (15.5 ± 12.7 vs 29.9 ± 20.9 ng/mmol, p < 0.05) before initiation of antiestrogens, and elevated dinor-6-keto output during the antiestrogen regimen (32.4 ± 21.2 vs 22.7 ± 8.7 ng/mmol, p = 0.07). Smokers (n = 6) had elevated dinor-TxB2 output before and during antiestrogen use. Thus we conclude that the cardiovascular protection provided by an antiestrogen regimen is unlikely to be mediated through vaso- and platelet active PGI2 and TxA2. 相似文献