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排序方式: 共有649条查询结果,搜索用时 140 毫秒
51.
ANNE MUST ENNO MERIVEE MARIKA MÄNd ANNE LUIK MIKK HEIDEMAA 《Physiological Entomology》2006,31(3):278-285
Abstract. Cold cells innervating antennal campaniform sensilla of the ground beetles Pterostichus oblongopunctatus (Fabricius, 1787) and Poecilus cupreus (Linnaeus, 1758) belonging to the tribe Pterostichini fire at a stationary rate of 22–23 imp s−1 at 23 °C. In P. oblongopunctatus , there is a strong negative correlation between the stationary firing rate of the cold cell and temperature. By contrast, no relationship between the firing rate and temperature is observed in P. cupreus. Mean peak frequencies, reaching up to nearly 500 Hz, and first-second firing rates, reaching up to 140 imp s−1 , are observed at the beginning of the phasic-tonic response to rapid cooling of the cold cells of P. cupreus, which are significantly higher than those for P. oblongopunctatus . However, firing rates of the cold cells of the two ground beetles studied do not differ 3 s later, during the tonic stabilization period of the response. The length of the long interspike period, lasting up to several seconds, at the beginning of rapid warming, is a positive function of the extent of change in temperature, and is longer in P. oblongopunctatus than in P. cupreus . These differences in the responses of the cold cells are related to the ecological preferences of the two ground beetles. 相似文献
52.
Maia LP 《Journal of mathematical biology》2005,51(1):114-122
This paper presents the exact analytical solution, valid for all generations and initial conditions, for the frequency distribution of haploids with infinite-sites genome carrying a given number of mutations in a population evolving deterministically on a truncated fitness landscape. This landscape is a generalization of the single sharp peak one, widely used in quasispecies theory, although here there are no reverse mutations. 相似文献
53.
Singh R Channappa RK Deeba F Nagaraj NJ Sukavaneaswaran MK Manjunath TM 《Plant cell reports》2005,24(9):556-560
Transgenic corn (MON 810), expressing the Bacillus thuringiensis (Bt) protein, Cry1Ab, was evaluated under greenhouse conditions for its tolerance to the maize stem borer, Chilo partellus. Bt corn (MON 810) provided effective protection against the stem borer even under a high level of larval infestation in the greenhouse. The observed tolerance is examined and discussed in the light of the susceptibility of C. partellus to the Cry1Ab protein in laboratory bioassays. The implications of the tissue concentrations of Cry1Ab in MON 810, and baseline susceptibility recorded in the current study, for insect-resistance management are discussed. 相似文献
54.
55.
A major time-consuming step of protein NMR structure determination is the generation of reliable NOESY cross peak lists which
usually requires a significant amount of manual interaction. Here we present a new algorithm for automated peak picking involving
wavelet de-noised NOESY spectra in a process where the identification of peaks is coupled to automated structure determination.
The core of this method is the generation of incremental peak lists by applying different wavelet de-noising procedures which
yield peak lists of a different noise content. In combination with additional filters which probe the consistency of the peak
lists, good convergence of the NOESY-based automated structure determination could be achieved. These algorithms were implemented
in the context of the ARIA software for automated NOE assignment and structure determination and were validated for a polysulfide-sulfur
transferase protein of known structure. The procedures presented here should be commonly applicable for efficient protein
NMR structure determination and automated NMR peak picking.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
56.
Yanase N Hata K Shimo K Hayashida M Evers BM Mizuguchi J 《Experimental cell research》2005,310(1):10-21
Interferon alpha (IFN-alpha) inhibits growth, at least in part, through induction of apoptosis. However, the molecular mechanisms underlying IFN-alpha-induced apoptosis are not completely understood. In the present study, we found that IFN-alpha induced a sustained activation of c-Jun N-terminal kinase 1 (JNK1), but not extracellular kinases (ERKs), in Daudi B lymphoma cells, as assessed by Western blotting using phospho-specific antibodies. Several lines of evidence support the notion that the IFN-alpha-induced activation of JNK is responsible for IFN-alpha-induced apoptosis, at least in part, through upregulation of TNF-related apoptosis-inducing ligand (TRAIL). First, pretreatment of Daudi cells with a JNK inhibitor reduced IFN-alpha-induced upregulation of TRAIL and loss of mitochondrial membrane potential (DeltaPsim) and annexin-positive cells, which was assessed by flow cytometry. Second, a dominant-negative form of JNK1 (dnJNK1) also reduced these apoptotic events, while a constitutively active form of JNK1, MKK7-JNK1beta, enhanced them. Finally, treatment with IFN-alpha enhanced the promoter activity of the TRAIL gene, which was partially abrogated by either JNK inhibitor or dnJNK1, while it was moderately enhanced by MKK7-JNK1beta. These findings are useful for understanding molecular mechanisms of IFN-alpha-induced apoptosis and also for development of treatment modalities of some tumors with IFN-alpha. 相似文献
57.
Pavel N. Gaponik Alexander S. Lyakhov Oleg A. Ivashkevich Jan Reedijk 《Inorganica chimica acta》2005,358(13):3949-3957
The data on synthesis, crystal structure, magnetic susceptibility and thermal properties of coordination compound of copper(II) chloride with 2-methyltetrazole (2mtet) of Cu(2mtet)2Cl2 composition are reported. The Cu atom environment forms an elongated octahedron, with two 2-methyltetrazole ligands (N4 bound) and two Cl atoms in the equatorial positions. Symmetry related 2-methyltetrazole ligand and Cl atom are in the axial positions. One of the two 2-methyltetrazole molecules of the asymmetric unit exhibits bridging properties being linked to two Cu atoms through two N atoms (i.e., N4 and N1) of the tetrazole ring, while the other ligand molecule is coordinated in monodentate fashion via one tetrazole N4 atom. The Cu-octahedra form dinuclear building bricks by sharing edges with equatorial and axial Cl atoms. These dinuclear units are linked together via bridging 2-methyltetrazole ligands to form infinite layers parallel to the plane. Magnetic properties of Cu(2mtet)2Cl2 and the data of quantum-chemical calculations of molecular electrostatic potential and energies of hydronation of nitrogen atoms for 2mtet using B3LYP/6-31G* level of theory are in agreement with the structural data obtained. 相似文献
58.
An unambiguous, fully ab initio and automated technique denoted AIPAR (ab initio parametrization) implemented in the SJBR program has been proposed to yield intermolecular interaction potentials between polar molecules and water. The AIPAR procedure has been applied to several organic molecules covering a wide range of structure and functional groups, namely methanol, acetone (propanone), methanethiol (methyl mercaptan), imidazole (1,3-diazole), oxazole and furan. The AIPAR-derived sets of parameters compare well with the empirical OPLS ones, mainly when the all-atoms model is employed in the OPLS procedure. Monte Carlo simulations were performed for an aqueous solution of methanol and for an equimolar binary mixture methanol–water using the AIPAR and OPLS parameters. The thermodynamic and geometric results obtained with the parameters obtained with the AIPAR procedure compare favorably with the OPLS simulations, even for the binary mixture, demonstrating the precision, robustness and transferability of the parameters obtained with the AIPAR procedure.Figure Superimposed configurations of water (without the hydrogen atoms) around the methanol molecule obtained with the AGOA procedure. 相似文献
59.
60.
Centrins are members of the calcium-binding EF-hand protein superfamily which can be divided into two subfamilies, probably associated with different functions: one related to Chlamydomonas reinhardtii centrin, CrCenp, and the other, represented by Saccharomyces cerevisiae isoform, ScCdc31p. ESTs encoding the two isoforms (BeCen1 and BeCen3) from the chytridiomycete Blastocladiella emersonii were isolated, and expression of the CrCenp-type centrin, BeCen1, was analyzed throughout the fungus life cycle. Becen1 mRNA levels increase transiently during sporulation and protein levels present a similar pattern. Immunolocalization studies seem to localize BeCen1 at the basal body zone and in the cytoplasm surrounding the nuclear cap, a zoospore organelle. 相似文献