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961.
Lisbeth A. Louderback Bruce M. Pavlik 《Human ecology: an interdisciplinary journal》2018,46(6):897-908
Ethnographic information on dietary plants can be cast into an ecological framework by using vegetation sampling techniques. Lists of ethnobotanical species become the basis of a dietary inventory that applies to a regional assemblage of vegetation types in a landscape associated with an archaeological site. But such lists are usually derived from many sources often without biogeographic or temporal reference. In effect, the dietary inventory represents potential food plants that may ultimately be found in archaeological deposits. The dietary palette, however, is composed of plant species that actually occur within the greater landscape of an archaeological site and that may or may not be known from the ethnographic record. Vegetation sampling provides a quantitative assessment of the dietary palette in the local ecosystem by using standard metrics, such as plant cover, basal area, density, and even productivity. By comparing vegetation data to the dietary inventory and archaeobotanical record, general patterns of foraging behavior as predicted by behavioral ecology are verified. This study of the Southern Paiute in south-central Utah also compares the plant species composition of modern and ancient landscapes, emphasizing a lack of correspondence between the dietary inventory and the dietary palette, as well as with the archaeobotanical record. Our example is from North Creek Shelter, a well-stratified archaeological site on the Colorado Plateau. 相似文献
962.
Identification and Function of Glycine Receptors in Cultured Cerebellar Granule Cells 总被引:2,自引:0,他引:2
Abstract: Poly(A)+ mRNA was isolated from cultured mouse cerebellar granule cells and injected into Xenopus oocytes. This led to the expression of receptors that evoked large membrane currents in response to glycine. Current-responses were also obtained after application of β-alanine and taurine, but these were very low relative to that of glycine (maximal β-alanine and taurine responses were 8 and 3% of that of glycine, respectively). The role of glycine receptors on K+ -evoked transmitter release in cultured cerebellar granule cells was also assayed. Release of preloaded d -[3 H]aspartate evoked by 40 m M K+ was dose dependently inhibited by glycine, and the concentration producing half-maximal inhibition was 50 μ M. Taurine, β-alanine, and the specific GABAA receptor agonist isoguvacine also inhibited K+ -evoked release, and the maximal inhibition was similar for all agonists (˜40%). The EC50 value was 200 μ M for taurine, 70 μ M for β-alanine, and 4 μ M for isoguvacine. Bicuculline (150 μ M ) antagonized the inhibitory effect of isoguvacine (150 μ M ) but not that of glycine (1 m M ). In contrast, strychnine (20 μ M ) antagonized the inhibitory effect of glycine (1 m M ) but not that of isoguvacine (150 μ M ). The pharmacology of the responses to β-alanine and taurine showed that these agonists activate both glycine and GABAA receptors. The results indicate that cultured cerebellar granule cells translate the gene for the glycine receptor and that activation of glycine receptors produces neuronal inhibition. 相似文献
963.
Stimulating rat thyroid FRTL-5 cells with agonists that activate the inositol phosphate cascade results in the release of sequestered calcium and influx of extracellular calcium. In addition, phospholipase A2 (PLA2) is activated. Since PLA2 is a calcium-dependent enzyme we wanted to investigate the interrelationships between PLA2 activity and the entry of calcium. Stimulating 3H-arachidonic acid (3H-AA)-labelled cells with thapsigargin resulted in a substantial release of 3H-AA. This release was totally abolished in a calcium-free buffer. Pretreatment of Fura 2 loaded cells with 4-bromophenacyl bromide, an inhibitor of PLA2 activity, decreased the thapsigargin-induced entry of calcium, suggesting a role for PLA2 in the regulation of calcium entry. In cells treated with nordihydroguaiaretic acid (NDGA), clotramizole, or econazole, compounds with lipoxygenase and cytochrome P-450 inhibitory actions, the thapsigargin-induced entry of calcium was decreased in a dose-dependent manner. However, treatment of the cells with indomethacin, a cyclooxygenase inhibitor, had no effect on the thapsigargin-induced calcium entry. We also showed that stimulation of the cells with arachidonic acid released sequestered calcium, apparently from the same intracellular pool as did thapsigargin. The results suggested that the calcium-induced PLA2 activation and the metabolism of the produced arachidonic acid by a noncyclooxygenase pathway may be of importance in maintaining calcium entry after releasing sequestered Ca2+ in FRTL-5 cells. © 1994 Wiley-Liss, Inc. 相似文献
964.
To test whether seawater–acclimatization of hatchery–reared anadromous and freshwater resident brown trout before release increased the survival of adults, smolts were retained 0, 2, 4 and 8 weeks in sea water before release. Total recapture rate increased for smolts retained 4 and 8 weeks in sea water before release relative to the controls. This trend was more pronounced for Freshwater resident than for anadromous stocks, Offspring of anadromous fish stayed longer at sea than offspring of freshwater resident fish. Recapture rates in fresh water were higher for brown trout released in the river than in the fjord in the R, Drammen area, but not in the R. Imsa. In both cases, most fish were recaptured in the sea. Moving into the R. Imsa (relative to other rivers) appeared higher for fish released at the mouth of the river (93%) than in the fjord (47%). Judged from the recapture rates, sea survival appeared to be the same whether released in the fjord or at the mouth of the river. 相似文献
965.
Two-year-old hatchery-reared progeny of inlet- and outlet spawning brown trout from Lake Tytifjorden were released at the mouth of the R. Imsa, south-western Norway. There were significant differences in migratory direction of juveniles between the two populations. After release, juvenile fish from the outlet river population moved against the current and ascended the R Imsa, while the inlet rivet fish tended to migrate with the water current to the sea. This differential response to water current in juveniles appears to be due to genetic differences between the populations, and parallels that found in their ancestors native environments. 相似文献
966.
Functional domains of Moloney murine leukemia virus integrase defined by mutation and complementation analysis. 总被引:4,自引:3,他引:1
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Retroviral integrases perform two catalytic steps, 3' processing and strand transfer, that result in the stable insertion of the retroviral DNA into the host genome. Mutant M-MuLV integrases were constructed to define the functional domains important for 3' processing, strand transfer, and disintegration by in vitro assays. N-terminal mutants had no detectable 3' processing activity, and only one mutant which lacks the HHCC domain, Ndelta105, had strand transfer activity. Strand transfer mediated by Ndelta105 showed preference for one site in the target DNA. Disintegration activity of N-terminal mutants decreased only minimally. In contrast, all C-terminal mutants truncated by more than 28 amino acids had no integration or disintegration activity. Activity on a single-strand disintegration substrate did not require a functional HHCC domain but did require most of the C-terminal region. Complementation analysis found that the HHCC region alone was able to function in trans to a promoter containing only the DD(35)E and C-terminal regions and to enhance integration site selection. Increasing the reducing conditions or adding the HHCC domain to Ndelta105 reaction mixtures restored the wild-type strand transfer activity and range of target sites. The reducing agent affected Cys-209 in the DD(35)E region. The presence of C-209 was required for complementation of Ndelta105 by the HHCC region. 相似文献
967.
The protein-DNA and protein-protein interactions important for function of the integrase (IN) protein of Moloney murine leukemia virus (M-MuLV) were investigated by using a coordinated-disintegration assay. A panel of M-MuLV IN mutants and substrate alterations highlighted distinctions between the intermolecular and intramolecular reactions of coordinated disintegration. Mispairing of the crossbone single-strand region and altered long terminal repeat (LTR) positioning affected the intermolecular, but not the intramolecular, reactions of coordinated disintegration. Partial components of the crossbone substrate were coordinated by M-MuLV IN, indicating a reliance on both LTR and target DNA determinants for substrate assembly. The intramolecular reaction was dependent on the presence of either the HHCC domain or a crossbone LTR 5' single-stranded tail. An M-MuLV IN mutant without the HHCC domain (Ndelta105) catalyzed reduced levels of double disintegration but not single disintegration. A separately purified HHCC domain protein (Cdelta232) stimulated double disintegration mediated by Ndelta105, suggesting a role of the N-terminal HHCC domain in stable IN-IN and IN-DNA interactions. Significantly, crossbone substrates lacking the LTR 5' tails were not recognized by the fingerless Ndelta105 protein. Collectively, these data suggest similar roles of the HHCC domain and 5' LTR tail in substrate recognition and modulation of IN activity. 相似文献
968.
G Strathdee R Sutherland J J Jonsson R Sataloff M Kohonen-Corish D Grady J Overhauser 《American journal of human genetics》1997,60(4):860-868
The 18q- syndrome is a deletion syndrome that is characterized by mental retardation, hearing loss, midfacial hypoplasia, growth deficiency, and limb anomalies. Most patients with this syndrome have deletions from 18q21-qter. We report on three patients with deletions of 18q23. A mother and daughter with identical deletions of 18q23 have many of the typical features of the 18q- syndrome, including midfacial hypoplasia and hearing loss. In contrast, the third patient has few of the symptoms of the 18q- syndrome. A contig of the 18q23 region was generated to aid in the mapping of the breakpoints. FISH was used to map both breakpoints to the same YAC clone. Furthermore, somatic-cell hybrids from the daughter and the third patient were isolated. The mapping results of sequence-tagged sites relative to the two breakpoints were identical, suggesting that the two deletion breakpoints map very close to one another. The analyses of these patients demonstrate that the critical region for the 18q- syndrome maps to 18q23 but that a deletion of 18q23 does not always lead to the clinical features associated with the syndrome. These patients demonstrate the wide phenotypic variability associated with deletions of 18q. 相似文献
969.
High climate velocity and population fragmentation may constrain climate‐driven range shift of the key habitat former Fucus vesiculosus
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Per R. Jonsson Jonne Kotta Helén C. Andersson Kristjan Herkül Elina Virtanen Antonia Nyström Sandman Kerstin Johannesson 《Diversity & distributions》2018,24(7):892-905
Aim
The Baltic Sea forms a unique regional sea with its salinity gradient ranging from marine to nearly freshwater conditions. It is one of the most environmentally impacted brackish seas worldwide, and the low biodiversity makes it particularly sensitive to anthropogenic pressures including climate change. We applied a novel combination of models to predict the fate of one of the dominant foundation species in the Baltic Sea, the bladder wrack Fucus vesiculosus.Location
The Baltic Sea.Methods
We used a species distribution model to predict climate change‐induced displacement of F. vesiculosus and combined these projections with a biophysical model of dispersal and connectivity to explore whether the dispersal rate of locally adapted genotypes may match estimated climate velocities to recolonize the receding salinity gradient. In addition, we used a population dynamic model to assess possible effects of habitat fragmentation.Results
The species distribution model showed that the habitat of F. vesiculosus is expected to dramatically shrink, mainly caused by the predicted reduction of salinity. In addition, the dispersal rate of locally adapted genotypes may not keep pace with estimated climate velocities rendering the recolonization of the receding salinity gradient more difficult. A simplistic model of population dynamics also indicated that the risk of local extinction may increase due to future habitat fragmentation.Main conclusions
Results point to a significant risk of locally adapted genotypes being unable to shift their ranges sufficiently fast considering the restricted dispersal and long generation time. The worst scenario is that F. vesiculosus may disappear from large parts of the Baltic Sea before the end of this century with large effects on the biodiversity and ecosystem functioning. We finally discuss how to reduce this risk through conservation actions, including assisted colonization and assisted evolution. 相似文献970.
Anna Skogh Anna Lesniak Christian Sköld Maria Karlgren Fabienne Z. Gaugaz Richard Svensson Shanti Diwakarla Anna Jonsson Rebecca Fransson Fred Nyberg Mathias Hallberg Anja Sandström 《Bioorganic & medicinal chemistry letters》2018,28(14):2446-2450
The dipeptide amide H-Phe-Phe-NH2 (1) that previously was identified as a ligand for the substance P 1–7 (SP1–7) binding site exerts intriguing results in animal models of neuropathic pain after central but not after peripheral administration. The dipeptide 1 is derived from stepwise modifications of the anti-nociceptive heptapeptide SP1–7 and the tetrapeptide endomorphin-2 that is also binding to the SP1–7 site. We herein report a strong anti-allodynic effect of a new H-Phe-Phe-NH2 peptidomimetic (4) comprising an imidazole ring as a bioisosteric element, in the spare nerve injury (SNI) mice model after peripheral administration. Peptidomimetic 4 was stable in plasma, displayed a fair membrane permeability and a favorable neurotoxic profile. Moreover, the effective dose (ED50) of 4 was superior as compared to gabapentin and morphine that are used in clinic. 相似文献