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201.
Summary The concentration, uptake and element use efficiency of N, P and K in one C3 annual (Polypogon monspeliensis) and two C4 (Echinochloa colonum, an annual, andDichathium annulatum, a perennial) grasses were determined during winter and summer seasons in monocultures raised in field plots at three moisture levels,viz. full, half and one-fourth of field capacity. At each moisture regime the plants were clipped thrice at moderate and severe levels corresponding to 40 and 80% of live green. The concentration of these elements was characteristic of the growth habit of these plants;e.g. the build up of concentration was maximum in leaf of the annuals while it was comparable in crown and leaf of Dichanthium. The N level was maximum in Polypogon. The nutrient use effiency was comparable in the two annuals and maximum K and N use were obtained in Polypogon and Dichanthium, respectively.  相似文献   
202.
Changes in the contents of starch, protein, DNA, RNA, total phosphorus, acid soluble phosphorus and inorganic phosphorus, and in the activities of some enzymes of carbohydrate, amino acid, nucleic acid and phosphate metabolism were studied during the germination of Cuscuta campestris seeds. The results are expressed on per seed basis.
Starch content in Cuscuta seeds showed a steady decline with most of it depleted by the end of the eighth day of germination. Protein content increased with germination up to 48 h and then decreased. RNA and DNA contents increased to a maximal level on the fourth day of germination and then decreased. Total phosphorus in the seeds remained almost unchanged during the period of study. Both trichloroacetic acid soluble and inorganic phosphorus increased until the third day and then decreased. Phytin was rapidly hydrolyzed with little being detectable by the seventh day of germination. Glucose-6-phosphate dehydrogenase increased with germination, while fructose bisphosphate aldolase which is indispensable for glycolysis, decreased with germination. Ribonuclease and deoxyribonuclease increased till the third and fourth day, respectively, and then decreased. Aspartate and alanine aminotransferases showed a maximum on the second day and then decreased. Activities of alkaline fructose-1,6-bisphosphatase and phytase were absent in the dry seeds and appeared only on the second day of germination. Both α- and β-amylase activities were present in the dry seed.  相似文献   
203.
Social interactions of the adult females (nulliparous, primiparous, multiparous young, and multiparous old) of the Arashiyama-B troop of Japanese monkeys were studied. Using focal-animal and instantaneous sampling techniques, specifically identified social interactions involving allogrooming, social play, and agonism, nonspecific body-contact with and proximity to other animals were recorded from 1975 to 1978. By identifying the animals who had the above mentioned social interactions with the focal females, an attempt has been made to analyze the changes in relationships between the females of different classes and their closest kins, distant kins, and non-kins. Multiparous young females spend more time in social interactions involving allogrooming, nonspecific body-contact, and proximity than do females of the other classes and most of their social interactions are centered around their own offspring. Social interactions of the nulliparous females are fewer than those of the young mothers. But, the social interactions of the nulliparous females with their kins are much more frequent than those of the other females, i.e., once a female bears offspring, she concentrates her efforts in raising it and her social life becomes closed than before. Social interactions of the old mothers decrease and their social life is also centered more around their own young offspring. However, the social interactions of the females with non-kins, the interactions which strengthen troop integration, are independent of the class of the females. This report constitutes one part of the thesis submitted by the author to the Faculty of Science of Kyoto University in 1979 for the award of degree of Doctor of Science.  相似文献   
204.
Data are presented on serological and electrophoretic variants of 18 systems of red cells in 228 individuals belonging to a scheduled tribe (Kanet) and a scheduled caste (Koli) of Kinnar district in Himachal Pradesh, India. Differences in gene frequencies clearly indicate biological distinction in the local population. The possible cause of this genetic heterogeneity is discussed.  相似文献   
205.
A determinate scheme for modeling the mechanical effects of muscle contractions in a musculoskeletal system, using the direct-stiffness method of structural analysis, is described. Data concerning skeletal geometries, connective tissue passive mechanical properties, and muscle lines-of-action and cross-sectional areas are incorporated to make the model specific for studies of muscle actions in the human trunk. Several illustrative examples of model trunk responses to muscle contractions are presented and discussed.  相似文献   
206.
The structure of the prosthetic group of citrate lyase (Klebsiella aerogenes) was studied by nuclear magnetic resonance and mass spectrometry. The spectra at 360 MHz of the nucleoside moiety (2'-ribosyladenosine) show the absence of 2'-hydroxyl proton, thus confirming the 2' position as the site of attachment of the second ribose moiety to the dephospho-CoA. This glycosidic linkage is found to be alpha(1" leads to 2') and is identical to that of poly(ADP-ribose). Studies of permethylation products by mass spectrometry support the above conclusion regarding the location of the ribosidic linkage.  相似文献   
207.
Three synthetic compounds which affect sphingolipid metabolism in vitro were examined for their effects on the synthesis in a rat brain system of nonhydroxyceramide, hydroxyceramide, nonhydroxycerebroside, and hydroxycerebroside from [1-14C]ignoceric acid. These compounds are N-octanoyl-D-threo-p-nitrophenylaminopropanediol (Compound I), N-(2,3-epoxydecanoyl)-norephedrine (Compound II), and N-decyl-N'-glucosylthiourea (Compound III). In the presence of up to 0.5 mM Compound I, only the hydroxyceramide fromation increased, while the synthesis of the other three lipids decreased. Compound II strongly inhibited the formation of all four lipids at all concentrations tested (0.1 to 1 mM). Compound III increased the synthesis of both ceramides approximately 2-fold at 1 mM, but the conversion of lignoceric acid to both cerebrosides remained relatively unchanged. Several significant conclusions from these observations are discussed.  相似文献   
208.
The B10.STA62 strain carries the H-2 w27 haplotype derived from a wild mouse captured in the vicinity of Ann Arbor, Michigan. Products of two class II loci composing this haplotype, A and A , are serologically, biochemically (by tryptic peptide mapping), and functionally indistinguishable from products controlled by the A b and A /b genes of the B10.A(5R) strain. In contrast, the polypeptide chain controlled by the third class II locus, E , is different from that controlled by the E /b gene. This E /w27 chain lacks an antigenic determinant present on the Eb molecule and carries determinants lacking on the Eb molecule, the E /b and E /w27 peptide maps differ in at least six peptides, and cytotoxic T cells specific for the E b chains do not react with B10.STA62 target cells. This great difference between the E /b and E /w27 chains suggests that the corresponding genes have not been derived from one another by a direct mutational conversion; instead, H-2 w27 appears to be a recombinant haplotype derived by crossing-over between the A A duplex and the E locus. This is the first recombinant discovered separating these class II loci.  相似文献   
209.
A probability model for the number of complete conceptions (that is, live births) taking into account foetal wastages, occurring in a couple during a specified period of time (T0, T0+T) is developed assuming that the data was collected starting a long time after marriage. A method of estimating some of the underlying parameters is given. The model is applied to data obtained in a Varanasi Survey in 1969–70.  相似文献   
210.
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