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The repeated-pairs of surnames in marriages (RP) approach is applied to the population of Tiszaszalka in north-eastern Hungary. The results indicate that: (1) lineage-like behaviour in mate choice results in population subdivision in both the Catholics and the Protestants of the village; (2) unlike in some other Tiszahat villages, the isonymous and the repeating unions in Tiszaszalka occur in different lineages so, in neither of these subpopulations are isonymous and repeating unions monopolised by a few lineages; (3) religious affilitation influences the mating structure of the population as measured by RP summary scores.  相似文献   
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JENNY F. DE LAET  RÉ A. DHONDT 《Ibis》1989,131(2):281-289
We tested the hypothesis that the weight lost by female Great and Blue Tits Parus major and P. caeruleus while raising their first brood influences their ability to start a second brood. The evening weight of female parents was recorded when the nestlings were 5 and 13 days old, in different years and habitats. Several predictions were tested: (1) both species lose weight while raising nestlings and Great Tit females which start a second brood lose less weight than females which do not; (2) differences in the average weight lost between years and areas correlate with differences in the proportion of second broods; (3) the relative weight loss in Blue Tits, which only rarely undertake second broods, is higher than in Great Tits in which second broods are more common. Other factors also are related to the probability of undertaking a second brood: more second broods are undertaken by more successful females, adult females and females that lay earlier.
The comparison of Great and Blue Tits suggests that the two species use different reproductive strategies.  相似文献   
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The climate of the native tropical forest habitats of Hylocereus undatus, a hemiepiphytic cactus cultivated in 20 countries for its fruit, can help explain the response of its net CO2 uptake to environmental factors. Under wet conditions, about 85% of the total daily net CO2 uptake occurs at night via Crassulacean acid metabolism, leading to a high water‐use efficiency. Total daily net CO2 uptake is reduced 57% by only 10 days of drought, possibly involving stomatal closure induced by abscisic acid produced in the roots, which typically occupy a small substrate volume. Total daily net CO2 uptake for H. undatus is maximal at day/night air temperatures of 30/20°C, optimal temperatures that are higher than those for desert cacti but representative of ambient temperatures in the tropics; its total daily net CO2 uptake becomes zero at day/night air temperatures of 42/32°C. Stem damage occurs at 45°C for H. undatus, whose photosynthetic cells show little acclimation to high temperatures compared with other cacti and are also sensitive to low temperatures, ‐1.5°C killing half of these cells. Consistent with its shaded habitat, total daily net CO2 uptake is appreciable at a total daily PPF of only 2 mol m2 day' and is maximal at 20 mol m?2 day?1, above which photoinhibition reduces net CO2 uptake. Net CO2 uptake ability, which is highly correlated with stem nitrogen and chlorophyll contents, changes only gradually (halftimes of 2–3 months) as the concentration of applied N is changed. Doubling the atmospheric CO2 concentration raises the total daily net CO2 uptake of H. undatus by 34% under optimal conditions and by even larger percentages under adverse environmental conditions.  相似文献   
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