排序方式: 共有64条查询结果,搜索用时 31 毫秒
21.
The different types and importance of British heaths 总被引:4,自引:0,他引:4
LYNNE FARRELL 《Botanical journal of the Linnean Society. Linnean Society of London》1989,101(3):291-299
FARRELL, L., 1989. The different types and importance of British heaths. A synopsis of the 22 types of heathland recognized by the National Vegetation Classification is presented. Maps showing their locations are given. 相似文献
22.
N-Acetyl-[3H]glucosamine supplied to intact 3 d old castor beanendosperm tissue was incorporated into TCA-insoluble productpresumed to be glycoprotein. After an incubation time of 2 hthe major paniculate location of this product within the cellwas the endoplasmic reticulum. Cell-free preparations containingparticulate enzymes transferred N-acetyl-[14C]glucosamine fromUDP-N-acetyl-[14C]glucosamine into a fraction soluble in chloroform/methanol(2: 1, by vol), a fraction soluble in chloroform/methanol/water(10: 10: 3, by vol.), and an insoluble residue. Mild acid hydrolysisreleased the saccharide moieties from the lipids. Paper chromatographicanalysis of the released saccharides established that the C/M-solubleproducts contained both N-acetyl-[14C]glucosamine and N, N'-diacetyl-[14C]chitobiose.In contrast, N-acetyl-[14C]glucosamine released from the C/M/W-solubleproduct was contained in an oligosaccharide, probably in associationwith unlabelled mannose residues. The stimulatory effect ofdolichol monophosphate and the inhibitory effect of tunicamycinon saccharide-lipid synthesis indicated that N-acetyl-glucosamineis transferred to a glycopolymer by the established reactionsof the dolichol monophosphate pathway. The enzymes catalysingthe constituent reactions of this pathway were exclusively locatedin the ER. 相似文献
23.
24.
The phylogenetic significance of bone types in euteleost fishes 总被引:1,自引:0,他引:1
LYNNE R. PARENTI F.L.S. 《Zoological Journal of the Linnean Society》1986,87(1):37-51
The paradentary is a small, sometimes dentigerous element in the lower jaw of some atherinomorph neoteleost fishes. Identification of the paradentary as a neomorphic, perichondrally ossified bone prompted re-examination of theories of the association of bone and teeth in teleost fishes. Teeth on a chondral lower jaw bone might be explained simply by epidermal-mesodermal interactions. Since the work of Kolliker in 1859, it has been known that there are two basic types of bone in teleost fishes: cellular bone, characterized by a matrix that has enclosed osteoblasts or osteocytes; and acellular bone, characterized by a relatively featureless matrix that lacks these bone-forming cells. Cellular bone is typical of lower teleosts, whereas acellular bone is typical of higher teleosts. Ontogenetic data indicate that acellular bone is derived relative to cellular bone. Even though identification of cellular and acellular bone can be made readily with histological preparations, acellular bone has been used infrequently as a character in analyses of teleost phylogeny. Acellular bone is considered here to be a derived character within teleost fishes. It is found in all Neoteleostei as well as some, but not all Salmoniformes. Independent of studies of bone, derived types of teeth in teleosts have been described in terms of their failure to become completely mineralized. Acellular bone and teeth of higher teleosts share several properties, including a large fraction of collagen. Teleosts lack a parathyroid gland; bone type is critical to the mechanism of calcium regulation. It is proposed that the character of acellular bone be incorporated into phylogenetic analyses of teleost fishes by correlating it with derived types of tooth structure. 相似文献
25.
LYNNE A. SCHEPARTZ 《American anthropologist》2006,108(3):595-596
Traces of Ancestry: Studies in Honour of Colin Renfrew. Martin Jones, ed. Oakville: David Brown Book Company, 2004. 161 pp. 相似文献
26.
FUNGAL COMMUNITIES IN ATTACHED ASH BRANCHES 总被引:4,自引:4,他引:0
27.
STEPHEN WAITE LYNNE FARRELL 《Botanical journal of the Linnean Society. Linnean Society of London》1998,126(1-2):109-121
In Britain, where it reaches the north-westerly limit of its European distribution, Orchis militaris L. is extremely rare. Well-established and persistent populations of O. militaris are known to exist at only two sites. The largest extant population of O. militaris occurs in a disused chalk pit in Suffolk. A preliminary demographic analysis of this population, covering the period 1975 to 1991, along with estimates of key life stage transition probabilities are presented here. From 1975 to 1986 the number of separate identifiable plants in the population declined substantially. Until 1986 recruitment of rosettes was poor. The largest cohort of new plants, recorded in 1976, was 35. Approximately 48% of new individuals recruited between 1976 and 1985 failed to flower. Of those flowering, approximately 55% flowered during their first year above ground. Of the original population recorded in 1975, 67.8% flowered at least once during the study. The reproductive performance, i.e. the frequency of flowering and the period between episodes of flowering, varied considerably between individuals. Some plants flowered every year while others only flowered once during the study. Few plants remained below ground for more than one year, while several apparently persisted below ground for more than 6 successive years. Although the number of plants that can be identified as separate individuals has declined, the total number of rosettes in the population has, from 1986, increased dramatically. Because of the dense clumping of these recruits it is not possible to determine whether they are derived from seed or vegetative propagation. When post 1986 recruitment is combined with the number of plants that established before 1986 and survive, the apparent number of plants present at the site has more than doubled between 1975 and1991. 相似文献
28.
Abstract: We studied how human use of trails affected foraging shorebirds over 24 months at 3 locations around San Francisco Bay, California, USA. By observing sites with trails and nearby sites without trails, we assessed whether numbers of trail users had an effect on the number of birds, species richness, or proportion of shorebirds foraging on tidal mudflats. Human use at non-trail sites averaged <1 person/hour, whereas use at trail sites averaged 68 people/hour. Despite these differences, we found no negative effects of trail use on the number of birds, species richness, or proportion of birds foraging, either overall or by season, when comparing trail to non-trail sites. Human use of trail sites on higher use days (typically weekends) averaged about 2.5 times the level on lower use days (typically weekdays). When comparing bird response on paired lower and higher use days at the trail sites, we found the number of shorebirds decreased with increasing trail use (F1,119 = 4.20, P = 0.043), with higher trail-use days averaging 25% fewer birds than on lower use days. Although managers may allow human use of trails adjacent to shorebird foraging areas under some conditions, high levels of trail use may negatively affect birds, making it essential to offer birds alternative, trail-free foraging opportunities. 相似文献
29.
LYNNE M. MULLEN RACHEL J. HIRSCHMANN KELLY L. PRINCE TRAVIS C. GLENN MICHAEL J. DEWEY HOPI E. HOEKSTRA 《Molecular ecology resources》2006,6(1):36-40
We isolated and characterized 60 novel microsatellite markers from the closely related oldfield mouse (Peromyscus polionotus) and deer mouse (Peromyscus maniculatus) for studies of conservation, ecological, quantitative and population genetics. We assessed all 60 markers in a wild population of Peromyscus polionotus rhoadsi (N = 20) from central Florida and found an average of nine alleles per marker and an observed heterozygosity (HO) of 0.66 (range = 0.00–1.00). These polymorphic markers contribute to the growing number of genomic resources for Peromyscus, an emerging model system for ecological and evolutionary research. 相似文献
30.
LYNNE R. PARENTI
fls 《Zoological Journal of the Linnean Society》2008,154(3):494-610
Ricefishes, known best by the model organism, the medaka, Oryzias latipes Temminck & Schlegel, 1846, comprise the family Adrianichthyidae, which ranges broadly throughout fresh and brackish waters of Central, South and Southeast Asia and the Indo‐Malay‐Philippines Archipelago as far east as Timor. Twenty‐eight Recent species are recognized here in two monophyletic genera, Adrianichthys and Oryzias. Xenopoecilus and Horaichthys are placed in synonymy of Oryzias for the first time. Adrianichthys comprises four species from Lake Poso, Sulawesi, Indonesia. Oryzias comprises 24 species that live throughout the range of the family. A fossil genus and species, ?Lithopoecilus brouweri from the Miocene of central Sulawesi, is included tentatively in the Adrianichthyidae. Evidence for the sister group relationship of adrianichthyids and exocoetoids is reviewed briefly and that relationship corroborated. Monophyly of adrianichthyids is likewise strongly supported here. Species groups within Oryzias are diagnosed as monophyletic largely based on osteology, colour pattern and meristic variation. They correspond only in part to species groups previously recognized based on chromosome constitution. Miniature species do not comprise a monophyletic group; disjunct absolute size in close relatives has evolved repeatedly. Oryzias latipes is a member of a species complex that includes O. luzonensis, O. curvinotus and the miniatures O. sinensis and O. mekongensis. A new species, Oryzias bonneorum sp. nov. , is described from Lake Lindu, Sulawesi, Indonesia. Lectotypes are designated for Haplochilus celebensis Weber, 1894 and Haplochilus timorensis Weber & de Beaufort, 1922. No claim to original US Government works. Journal compilation © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 494–610. 相似文献