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31.
Functional neuroimaging uses activity-dependent changes in cerebral blood flow to map brain activity, but the contributions of presynaptic and postsynaptic activity are incompletely understood, as are the underlying cellular pathways. Using intravital multiphoton microscopy, we measured presynaptic activity, postsynaptic neuronal and astrocytic calcium responses, and erythrocyte velocity and flux in olfactory glomeruli during odor stimulation in mice. Odor-evoked functional hyperemia in glomerular capillaries was highly correlated with glutamate release, but did not require local postsynaptic activity. Odor stimulation induced calcium transients in astrocyte endfeet and an associated dilation of upstream arterioles. Calcium elevations in astrocytes and functional hyperemia depended on astrocytic metabotropic glutamate receptor 5 and cyclooxygenase activation. Astrocytic glutamate transporters also contributed to functional hyperemia through mechanisms independent of calcium rises and cyclooxygenase activation. These local pathways initiated by glutamate account for a large part of the coupling between synaptic activity and functional hyperemia in the olfactory bulb. 相似文献
32.
Dinu II Hayes RJ Kynast RG Phillips RL Thill CA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,110(3):403-415
Sexual hybrids between distantly related Solanum species can undergo endosperm failure, a post-zygotic barrier in inter-species hybridizations. This barrier is explained by the endosperm balance number (EBN) hypothesis, which states that parents must have corresponding EBNs for viable seed formation. Tests for inter-crossability were made involving the Mexican species Solanum pinnatisectum Dunal. (series Pinnatisecta, ApiApi, 1EBN), autotetraploids of this species, Solanum verrucosum Schlechtd. (series Tuberosa, AA, 2EBN), haploids (2x, 2EBN) of the South American S. tuberosum L. (series Tuberosa, A1A1A2A2, 4EBN), and F2 haploid-species hybrids with South American species (AA, 2EBN) S. berthaultii Hawkes, S. sparsipilum (Bitter.) Juz. and Bukasov and S. chacoense Bitter. The development of hybrid endosperms was investigated for these combinations by confocal microscopy with regard to cell-division timing and tissue collapse. Novel sexual diploid (AApi) and triploid (AApiApi) inter-series hybrids were generated from S. verrucosum × S. pinnatisectum crosses by using post-pollination applications of auxin. F1 embryos were rescued in vitro. The hybrid status of recovered plants was verified by microsatellite marker analysis, and the ploidy was determined by chromosome counting. The application of phytohormones in inter-ploidy S. pinnatisectum × S. tuberosum crosses, however, did not delay endosperm collapse, and embryos were not formed. Other diploid, 1EBN species tested in remote hybridizations with Group Tuberosum were S. cardiophyllum Lindl., S. trifidum Correll, and S. tarnii Hawkes and Hjert., series Pinnatisecta, and S. bulbocastanum Dunal., series Bulbocastana. Based on the analysis of post-zygotic reproductive barriers among isolated species of section Petota, we propose strategies to overcome such incompatibilities. 相似文献
33.
Tolonen AC Albeanu DF Corbett JF Handley H Henson C Malik P 《Nucleic acids research》2002,30(20):e107
Oligonucleotide arrays are powerful tools to study changes in gene expression for whole genomes. These arrays can be synthesized by adapting photolithographic techniques used in microelectronics. Using this method, oligonucleotides are built base by base directly on the array surface by numerous cycles of photodeprotection and nucleotide addition. In this paper we examine strategies to reduce the number of synthesis cycles required to construct oligonucleotide arrays. By computer modeling oligonucleotide synthesis, we found that the number of required synthesis cycles could be significantly reduced by focusing upon how oligonucleotides are chosen from within genes and upon the order in which nucleotides are deposited on the array. The methods described here could provide a more efficient strategy to produce oligonucleotide arrays. 相似文献
34.
Background
Restriction enzymes can produce easily definable segments from DNA sequences by using a variety of cut patterns. There are, however, no software tools that can aid in gene building -- that is, modifying wild-type DNA sequences to express the same wild-type amino acid sequences but with enhanced codons, specific cut sites, unique post-translational modifications, and other engineered-in components for recombinant applications. A fast DNA pattern design algorithm, ICRPfinder, is provided in this paper and applied to find or create potential recognition sites in target coding sequences. 相似文献35.
Background
Gene set analysis (GSA) methods test the association of sets of genes with phenotypes in gene expression microarray studies. While GSA methods on a single binary or categorical phenotype abounds, little attention has been paid to the case of a continuous phenotype, and there is no method to accommodate correlated multiple continuous phenotypes.Result
We propose here an extension of the linear combination test (LCT) to its new version for multiple continuous phenotypes, incorporating correlations among gene expressions of functionally related gene sets, as well as correlations among multiple phenotypes. Further, we extend our new method to its nonlinear version, referred as nonlinear combination test (NLCT), to test potential nonlinear association of gene sets with multiple phenotypes. Simulation study and a real microarray example demonstrate the practical aspects of the proposed methods.Conclusion
The proposed approaches are effective in controlling type I errors and powerful in testing associations between gene-sets and multiple continuous phenotypes. They are both computationally effective. Naively (univariately) analyzing a group of multiple correlated phenotypes could be dangerous. R-codes to perform LCT and NLCT for multiple continuous phenotypes are available at http://www.ualberta.ca/~yyasui/homepage.html.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2105-15-260) contains supplementary material, which is available to authorized users. 相似文献36.
Dinu Paraschivescu 《Insectes Sociaux》1967,14(2):123-130
Zusammenfassung In einem Beobachtungsnest wurde der westhan der AmeiseCataglyphis cutsot ænescens Nyl., experimentell verfolgt. 3 m Vergleich mit den im Freien befindlichen natürlichen Nestern konnten keine wesentlichen Unterschiede in der Bauart festgestellt werden.Die experimentellen Untersuchungen über die Nahrung und die Nahrungsaufnahme der Ameise ergaben, dass dieselbe eine fleischfressende Art ist, Insekten als Nahrung bevorzugtund nur ausnahmsweise auch vegetabilien, wie Fruchtsäfte, aufnimmt.Versuche zur Ermittlung des Einflusses der Temperatur auf die Entwicklung der Ameise wurden ebenfalls angestellt.Die Versuche wurden in einem vom Verfasser hergestellten Beobachtungsnest ausgeführt.
Summary Pursuing experimentally the construction of the nest and the nutrition of the ants of the kindCataglyphis cursor ænescens Nyl., the author has observed the ressemblance of the plan of construction of the artificial nest with that of the natural ones, with regard to number of rooms ans galleries. In the same time there were studies about the influence of the temperature on the evolution of this kind of ants.As far as nutrition is concerned the author shows that this kind of ants are carnivorous (eats insects) and less phytophaganous, consuming only the juices of the fruits given to them as food.The experiments were mate in an artificial nest of an original model.
Résumé Poursuivant à titre expérimental la construction du nid et la nutrition chez les fourmis de l'espèceCataglyphis cursor ænescens Nyl., l'auteur a observé la ressemblance du plan de la construction du nid artificiel avec celui du nid naturel, en ce qui concerne le nombre des chambres et des galeries. Il a en même temps étudié l'influence de la température quant au développement de cette espèce.En ce qui concerne la nutrition, l'auteur montre que l'espèce est carnivore (se nourrissant d'insectes) et moins végétarienne, en consommant seulement les sucs des fruits qu'on leur administre comme nourriture.Les expériences ont été faites dans un nid artificiel d'un modèle original.相似文献
37.
Escherichia coli O157:H7 continues to be an important human pathogen and has been increasingly linked to food-borne illness associated with fresh produce, particularly leafy greens. The aim of this work was to investigate the fate of E. coli O157:H7 on the phyllosphere of lettuce under low temperature and to evaluate the potential hazard of viable but nonculturable (VBNC) cells induced under such stressful conditions. First, we studied the survival of six bacterial strains following prolonged storage in water at low temperature (4°C) and selected two strains with different nonculturable responses for the construction of E. coli O157:H7 Tn7gfp transformants in order to quantitatively assess the occurrence of human pathogens on the plant surface. Under a suboptimal growth temperature (16°C), both E. coli O157:H7 strains maintained culturability on lettuce leaves, but under more stressful conditions (8°C), the bacterial populations evolved toward the VBNC state. The strain-dependent nonculturable response was more evident in the experiments with different inoculum doses (10(9) and 10(6) E. coli O157:H7 bacteria per g of leaf) when strain BRMSID 188 lost culturability after 15 days and strain ATCC 43895 lost culturability within 7 days, regardless of the inoculum dose. However, the number of cells entering the VBNC state in high-cell-density inoculum (approximately 55%) was lower than in low-cell-density inoculum (approximately 70%). We recorded the presence of verotoxin for 3 days in samples that contained a VBNC population of 4 to 5 log(10) cells but did not detect culturable cells. These findings indicate that E. coli O157:H7 VBNC cells are induced on lettuce plants, and this may have implications regarding food safety. 相似文献
38.
Alexandros Onoufriadis Tamara Paff Dinu Antony Amelia Shoemark Dimitra Micha Bertus Kuyt Miriam Schmidts Stavroula Petridi Jeanette?E. Dankert-Roelse Eric?G. Haarman Johannes?M.A. Daniels Richard?D. Emes Robert Wilson Claire Hogg Peter?J. Scambler Eddie?M.K. Chung UKK Gerard Pals Hannah?M. Mitchison 《American journal of human genetics》2013,92(1):88-98
39.
Dinu Stefan Hosni Popotte Andreea Raluca Stefan Audrey Tesniere Aurélie Tomaszewski Paul Lesueur Jean-Louis Habrand Laurence Verneuil 《Reports of Practical Oncology and Radiotherapy》2016,21(1):76-80
A 56-year-old man with BRAFV600E melanoma and spinal metastases treated with vemurafenib and stereotactic radiation showed a partial response without neurological, skin or mucosal toxicity, 8 months after completion of this combination. This case suggests that stereotactic radiation spares normal tissues and might be safer than conventional fractionated radiation with vemurafenib. 相似文献
40.
Navdeep Grover Marc P. Douaisi Indrakant V. Borkar Lillian Lee Cerasela Zoica Dinu Ravi S. Kane Jonathan S. Dordick 《Applied microbiology and biotechnology》2013,97(19):8813-8821
AcT (perhydrolase) containing paint composites were prepared leading to broad-spectrum decontamination. AcT was immobilized onto multi-walled carbon nanotubes (MWNTs) and then incorporated into latex-based paints to form catalytic coatings. These AcT-based paint composites showed a 6-log reduction in the viability of spores of Bacillus cereus and Bacillus anthracis (Sterne) within 60 min. The paint composites also showed >4-log reduction in the titer of influenza virus (X-31) within 10 min (initially challenged with 107 PFU/mL). AcT-based paint composites were also tested using various perhydrolase acyl donor substrates, including propylene glycol diacetate (PGD), glyceryl triacetate, and ethyl acetate, with PGD observed to be the best among the substrates tested for generation of peracetic acid and killing of bacillus spores. The operational stability of paint composites was also studied at different relative humidities and temperatures to simulate real-life operation. 相似文献