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1.
Chloroplast protein synthesis was measured during the expansion,maturity and senescence of the oldest leaf of barley, Hordeumvulgare L., var. Hassan. A maximum rate of protein synthesisoccurred near the end of the expansion stage 9 d after sowing.Protein synthesis increased again at the beginning of senescenceand reached a new maximum at day 14 after sowing. Detachmentand incubation of leaves in the dark stimulated chioroplastprotein synthesis by fully expanded or by senescent leaves butnot by expanding leaves. If the detached leaves were kept inthe light, chloroplast protein synthesis was stimulated in fullyexpanded but not in senescent leaves. Short treatments (18 h)of leaf segments with growth substances in either light or indarkness, significantly changed the rate of protein synthesisshown by chloroplasts. The relationship between chloroplastprotein synthesis and leaf senescence is discussed. Key words: Hormones, light, maturity  相似文献   
2.
We compiled a large database of 58 059 point locality records for 70 species and 434 subspecies of heliconiine butterflies and used these data to test evolutionary hypotheses for their diversification. To study geographical patterns of diversity and contact zones, we mapped: (1) species richness; (2) mean molecular phylogenetic terminal branch length; (3) subspecies richness and the proportion of specimens that were subspecific hybrids, and (4) museum sampling effort. Heliconiine species richness is high throughout the Amazon region and peaks near the equator in the foothills and middle elevations of the eastern Andes. Mean phylogenetic terminal branch length is lowest in the eastern Andes and tends to be low in species‐rich areas. By contrast, areas of high subspecies richness, where subspecies overlap in range and/or hybridize, are concentrated along the course of the Amazon River, with the eastern Andes slopes and foothills relatively depauperate in terms of local intraspecific phenotypic diversity. Spatial gradients in heliconiine species richness in the Neotropics are consistent with the hypothesis that species richness gradients are driven at least in part by variation in speciation and/or extinction rates, resulting in observed gradients in mean phylogenetic branch length, rather than via evolutionary age or niche conservatism alone. The data obtained in the present study, coupled with individual case studies of recently evolved Heliconius species, suggest that the radiation of heliconiine butterflies occurred predominantly on the eastern slopes of the Andes in Colombia, Ecuador, and Peru, as well as in the upper/middle Amazon basin. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 479–497.  相似文献   
3.
Achenes of all the Tragopogon species from the Iberian Peninsula were examined by means of scanning-electron microscopy and stereomicroscopy. The achenes of the eight species are described, illustrated and compared. The results are contrasted with the systematics of this genus. The isolated position of T. lamottei with regard to the other seven species is noted. A key is provided to enable the different species to be distinguished.  相似文献   
4.
Sensory evaluation is a scientific method that deals with precision, accuracy and sensitivity. Its basic principles are in large part anchored on the natural sciences, such as biology, chemistry, mathematics and physics. However, sensory evaluation goes beyond such platforms and has its own social, economic and cultural facets. Sensory evaluation has been extensively used in the study of consumer items such as food and clothing, and lately on behavioral and physiological reactions. It has been an integral part of the food science curriculum in various universities. However, the other disciplines of home economics, such as clothing technology, family life and child development, home economics education, hotel, restaurant and institution management, interior design and community nutrition, which deal with the needs of families and consumers, have not fully maximized the use of sensory evaluation. The multidisciplinary nature of home economics will push sensory evaluation to a more diverse level of relevance and purpose. This paper presented the social, economic and cultural dimensions of sensory evaluation along with its possible applications in the various disciplines of home economics in the Philippines.

PRACTICAL APPLICATIONS


The paper provided a wholistic view of sensory evaluation not merely as a scientific method but its important social, cultural and economic dimensions. This document can serve as a guide for students, teachers and professionals in the conduct of sensory assessments. Likewise, this will help home economists not only in the Philippines but also in other countries to maximize the use of sensory evaluation in improving the quality of life of families and consumers. Moreover, this can drive multidisciplinary undertakings utilizing sensory evaluation as the key concept and thus enrich the pool of knowledge both in the natural and social sciences and their interaction.  相似文献   
5.
A new genus and species combination are proposed for Urocryptum tortum n. gen., n. comb., a scuticociliate with a polymorphic life cycle. This marine ciliate was isolated from a sample taken at Gokasho Bay in Mie Prefecture (Japan). Specimens from different phases of the growth cycle were examined in vivo and with two silver staining techniques. Three life-history stages were observed: an exponential growth phase stage (trophont), a stationary phase stage (tomite), and finally a resting stage (cyst). The exponential growth form is laterally flattened and ovoid; it has 20-24 somatic kineties (SK) and a typical complement of scuticociliate oral structures. Polykinetid 1 (Pk1) has two longitudinal files of 6 kinetosomes (Ks); sometimes one or two additional kinetosomes are located anteriorly. Polykinetid 2 (Pk2) has two files of 6 or 7 Ks; a third file of three widely spaced kinetosomes is located on its right side, as well as a small curved row of 5 Ks positioned on the right hand side of the posterior end of Pk2. Polykinetid 3 (Pk3) has 3 rows of 4, 5, and 7 Ks's perpendicular to the haplokinety (Hk) or paroral membrane. The stationary growth phase cell is spindle-shaped and has a similar number of SK that are much more closely spaced than in exponentially growing specimens. Oral infraciliary structures are reduced in size, having fewer kinetosomes and being positioned more anteriorly in the cell. Pk1 is composed of two files of 5-Ks, Pk2 has only two files of 6-7 Ks, and Pk3 has two to three rows of 3-4 Ks. The Hk is displaced anteriorly and becomes straight, losing the shape typical of exponential growth phase cells. Cysts are pyriform with a wide cyst wall; no infraciliary structures were visible.  相似文献   
6.
Tragopogon cazorlanum (Asteraceae: Lactuceae) is proposed as a new Spanish species with distribution restricted to the Baetic mountains (south-eastern Spain). Its morphological, palynological, chromosomal, biogeographical and ecological features are discussed, as well as its main relationships and differences with reference to other Spanish species of the genus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 505–511.  相似文献   
7.
Key questions for understanding the resilience and variability of Mexican Neotropical cloud forest assemblages in current and future climate change include: How have human disturbances and climate change affected the dynamics of the cloud forest assemblage? What are the predominant processes responsible for its present day composition and distribution? Are the current conservation strategies for the cloud forest in accordance with preserving its natural variability through time? In this study, the temporal dynamics of the cloud forest in west‐central Mexico over the last ~1300 years were reconstructed using palaeoecological techniques. These included analyses of fossil pollen, microfossil charcoal, and sediment geochemistry. Results indicated that a cloud forest assemblage has been the predominant vegetation type in this region over the last ~1300 years. During this time, however, there have been changes in the vegetation with an apparent expansion of cloud forest from ~832 to 620 cal years bp and a decline from 1200 to 832 cal years bp . Climate change (intervals of aridity) and human disturbances through anthropogenic burning appear to have been the main factors influencing the dynamics of this cloud forest. The spatial heterogeneity reported for high‐altitude forests in this region, in concert with high beta diversity, appears to be a manifestation of the high temporal variability in species composition for these forests. Greater turnover in cloud forest taxa occurred during intervals of increased humidity and is probably representative of a higher temporal competition for resources among the cloud forest taxa. The present results support the current protection scheme for cloud forests in west‐central Mexico where areas are kept in exclusion zones to avoid timber extraction, grazing, and agriculture; this will maintain diversity within these forests, even if there are only a few individuals per species, and enable the forests to retain some resilience to current and future climate change.  相似文献   
8.
ABSTRACT. Unusual prostomatid specimens were found in the biological reactor of a wastewater treatment plant in a health resort in Valencia, Spain. These ciliates were attached to flocs unlike other free‐swimming prostomatid ciliates described to date in the mixed liquor of activated sludge plants. The morphological study of this species led to a typically different combination of characteristics: elongated cell shape, 20–30 somatic kineties, 2 perioral kineties, and 1 circumoral kinety, 1 large vacuole protruding at the terminal end, a lorica tapered toward the aperture with a smooth neck, and 11–16 annular ridges. These characteristics place this representative as a new species of the genus MetacystisMetacystis galiani n. sp. This species became the dominant population within the biological reactor when high values of conductivity (4,244 mS/cm) and temperature (26.8 °C) were recorded.  相似文献   
9.
The study determined the 6-n-propylthiouracil (PROP) status of Filipino adults and how it relates to their body mass indices (BMI) and food preferences. Self-reported food preference checklists were administered to 100 male and female adults aged 18–60, classified according to BMI. Increasing concentrations of PROP and NaCl solutions were rated in labeled magnitude scale to establish the PROP taster status of the selected respondents. The Filipino adult respondents were composed of 12% nontasters, 45% medium tasters and 43% supertasters. No association ( P >  0.05) between BMI and PROP taster status was found. Sweet-tasting foods were the most preferred and bitter-tasting foods were the least preferred within each taster status. Furthermore, medium tasters and supertasters had the highest acceptance for meats, fish and poultry, and least acceptance for beverages, which were mostly bitter. Decreased preferences for fats and oils, sugars and confectionery, and beverages were correlated ( P <  0.05) with responsiveness to PROP.

PRACTICAL APPLICATIONS


The research provides a general baseline data of the PROP taster status of Filipino adults. The findings from this study can be used as a reference and can be compared to similar studies conducted in other countries. Likewise, the information from the study can add to the scarce data for taste genetics specifically for the Asian population. The relationship of PROP taster status with body mass index and food preferences can be a guide in the design of products and dietary plans. Likewise, the study would be a means to understand why people vary in liking for particular food items and how these can be reflected in their food consumption and nutritional status.  相似文献   
10.
The influence of autolysis upon the cell walls of Neurosporacrassa has been studied. This fungus was grown at 24 °Cin agitated and aerated cultures in a synthetic medium during60 days. At convenient intervals samples of culture were taken,mycelium separated, and dried to constant weight. From aliquotsof these mycelia cell walls were prepared, dried, weighed, andanalysed for total nitrogen, phosphorus, amino acids, lipids,and protein. No changes in the chemical composition of the wallscould be detected. The percentage of walls continuously increasedduring autolysis. These results strongly suggest that cell wallsof N. crassa are unaffected by autolysis. Examination of thefine structure of the whole mycelium at different ages duringautolysis seemed to confirm these findings.  相似文献   
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