957 resultados para New Thought
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Expansins are extracellular proteins that increase plant cell wall extensibility in vitro and are thought to be involved in cell expansion. We showed in a previous study that administration of an exogenous expansin protein can trigger the initiation of leaflike structures on the shoot apical meristem of tomato. Here, we studied the expression patterns of two tomato expansin genes, LeExp2 and LeExp18. LeExp2 is preferentially expressed in expanding tissues, whereas LeExp18 is expressed preferentially in tissues with meristematic activity. In situ hybridization experiments showed that LeExp18 expression is elevated in a group of cells, called I1, which is the site of incipient leaf primordium initiation. Thus, LeExp18 expression is a molecular marker for leaf initiation, predicting the site of primordium formation at a time before histological changes can be detected. We propose a model for the regulation of phyllotaxis that postulates a crucial role for expansin in leaf primordium initiation.
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A 100-m-thick Paleocene sequence of mainly pelagic sediments at ODP Site 1121, on the eastern flanks of the Campbell Plateau, contains few to common radiolarians of relatively low diversity in the lower 40 m (Early to early Late Paleocene) and abundant, diverse radiolarian assemblages in the upper 60 m (mid-Late Paleocene). The 150 taxa recorded from the entire Paleocene interval are thought to under-represent the actual species diversity by at least one half as many morphotypes have not been differentiated below the level of genus. Assemblages in the lower 40 m are similar to those described from onland New Zealand and DSDP Site 208 (northern Lord Howe Rise); they are correlated with South Pacific radiolarian zones RP4 and RP5. Assemblages in the upper 60 m differ from other known Late Paleocene assemblages in the great abundance of plagiacanthids and cycladophorids. Similarities are noted with later Cenozoic cool-water assemblages. This upper interval is correlated with South Pacific zone RP6, as revised herein, based on comparison with faunas from Site 208 and Marlborough, New Zealand. The interval is also correlated with the upper part of North Atlantic zone RP6 (RP6b-c) based on the presence of Aspis velutochlamydosaurus, Plectodiscus circularis and Pterocodon poculum. Other species, such as Buryella tetradica and Buryella pentadica, are valuable for local correlation but exhibit considerable diachroneity between the Pacific, Indian and Atlantic Oceans. An age model for the Paleocene interval at Site 1121, based on well-constrained nannofossil and radiolarian datums, indicates that the rate of compacted sediment accumulation doubles from 15 to 30 mm/ka at the RP5/RP6 zonal boundary. In large part this is due to a sudden and pronounced increase in accumulation rates for all siliceous fossils; radiolarians and larger diatoms increase from <100 to >10 000 specimens/cm2/ka. This apparent increase in biosiliceous productivity is age-equivalent to a mid-Paleocene cooling event (57-59 Ma) identified from global stable isotope records that is associated with the heaviest delta13C values for the entire Cenozoic.
Neuroprotective activity of a new class of steroidal inhibitors of the N-methyl-d-aspartate receptor
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Release of the excitatory neurotransmitter glutamate and the excessive stimulation of N-methyl-d-aspartate (NMDA)-type glutamate receptors is thought to be responsible for much of the neuronal death that occurs following focal hypoxia-ischemia in the central nervous system. Our laboratory has identified endogenous sulfated steroids that potentiate or inhibit NMDA-induced currents. Here we report that 3α-ol-5β-pregnan-20-one hemisuccinate (3α5βHS), a synthetic homologue of naturally occurring pregnanolone sulfate, inhibits NMDA-induced currents and cell death in primary cultures of rat hippocampal neurons. 3α5βHS exhibits sedative, anticonvulsant, and analgesic properties consistent with an action at NMDA-type glutamate receptors. Intravenous administration of 3α5βHS to rats (at a nonsedating dose) following focal cerebral ischemia induced by middle cerebral artery occlusion significantly reduces cortical and subcortical infarct size. The in vitro and in vivo neuroprotective effects of 3α5βHS demonstrate that this steroid represents a new class of potentially useful therapeutic agents for the treatment of stroke and certain neurodegenerative diseases that involve over activation of NMDA receptors.
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DNA sequence analysis dictates new interpretation of phylogenic trees. Taxa that were once thought to represent successive grades of complexity at the base of the metazoan tree are being displaced to much higher positions inside the tree. This leaves no evolutionary “intermediates” and forces us to rethink the genesis of bilaterian complexity.
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Retinitis pigmentosa (RP) is a group of progressive inherited retinal dystrophies that cause visual impairment as a result of photoreceptor cell death. RP is heterogeneous, both clinically and genetically making difficult to establish precise genotype–phenotype correlations. In a Spanish family with autosomal recessive RP (arRP), homozygosity mapping and whole-exome sequencing led to the identification of a homozygous mutation (c.358_359delGT; p.Ala122Leufs*2) in the ZNF408 gene. A screening performed in 217 additional unrelated families revealed another homozygous mutation (c.1621C>T; p.Arg541Cys) in an isolated RP case. ZNF408 encodes a transcription factor that harbors 10 predicted C2H2-type fingers thought to be implicated in DNA binding. To elucidate the ZNF408 role in the retina and the pathogenesis of these mutations we have performed different functional studies. By immunohistochemical analysis in healthy human retina, we identified that ZNF408 is expressed in both cone and rod photoreceptors, in a specific type of amacrine and ganglion cells, and in retinal blood vessels. ZNF408 revealed a cytoplasmic localization and a nuclear distribution in areas corresponding with the euchromatin fraction. Immunolocalization studies showed a partial mislocalization of the p.Arg541Cys mutant protein retaining part of the WT protein in the cytoplasm. Our study demonstrates that ZNF408, previously associated with Familial Exudative Vitreoretinopathy (FEVR), is a new gene causing arRP with vitreous condensations supporting the evidence that this protein plays additional functions into the human retina.
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Copies of warrants and writs concerning public unrest caused by an attempt to survey lands on Long Island in 1702.
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Stirner and Feyerabend, despite being historically a hundred and fifty years apart, seem to have been of the same mind in revolting against the methodological explaining of what cannot methodologically be explained. Stirner attempted an explanation in a more intuitive version, Feyerabend in a more sophisticated one. For both thinkers it is obviously important to sustain dissent with the assumption that method is the one and only vital promoter of scientific progress. They equally voice the opinion that, despite science itself producing inconsistencies as well as results, its proceedings nonetheless follow a certain rationale. But to codify a definite approach to phenomena or matter i.e. to establish a definite method for taking a look into things turns science into religion and scientists into believers. As a result no new insights are to be gained.
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Introduction. Regional government in contemporary western Europe corresponds to a type of society and economy variously labeled "post-industrial", "post-bourgeois" or merely "the New Europe."l This New Europe evolved historically from the interconnected strands of capitalism; industrialism and pluralistic democracy. It resembles in many respects the type of economy and society familiar to us in North America. Regional government in such a society is thus merely an adaptation on the scale of half a continent of forms of social and economic organization which evolved historically at the national level. Regional government in the New Europe is the institutional and political recognition that societies have changed dramatically since 1945, so dramatically that they cannot be adequately described in the doctrines and ideologies made familiar by nineteenth and early twentieth century political thought. Hence the New Europe and its regional government is the future of that part of history which has also been aptly described as "the end of ideology."
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Introduction. It is quite uncommon to associate migration with the rules on services trade. Indeed, all economic definitions of services insist on their immaterial nature and on the increased possibility of trading them ‘virtually’ over networks or else, without any physical movement of the parties involved. Somehow this ‘immaterial’ nature of services reflects on their providers/recipients which seem to be ‘invisible’. Even though most services still require the physical contact of the provider with the recipient1 and, when provided over national borders, do entail migration, service providers and/or recipients are rarely thought of as ‘immigrants’. This may be due to the fact that they enter the foreign territory with a specific aim and, once this aim accomplished, move back to their state of origin; technically they only qualify as short term non-cyclical migrants and are of little interest to policy-makers. A second reason may be that both service providers and recipients are economically desirable: the former are typically highly skilled and trained professionals and the latter are well-off ‘visitors’, increasing consumption in the host state. The legal definition of services in Article 57 TFEU (ex Art. 50 EC) further nourishes this idea about service providers/recipients not being migrants: the relevant Treaty rules only apply when the provisions on free movement of workers and freedom of establishment – themselves clearly linked to migration – do not apply. This distinction has been fleshed up by the ECJ which has consistently held that the distinction between the rules on establishment, on the one hand, and the rules on services, on the other, lies on duration.2 Indeed, all EC manuals state four types of service provision falling under the EC Treaty: a) where the service provider moves to the recipient’s state, for a short period of time (longer stay would amount to establishment), b) where the service recipients themselves move to the state where the service is offered (eg for medical care, education, tourism etc), c) where both service providers and recipients move together in another member state (eg a tourist guide accompanying a group travelling abroad) and d) where the service itself is provided across the borders (typically through the use of ICTs). None of these situations would typically qualify as migration. The above ‘dissociation’ between services and migration has been gradually weakened in the recent years. Indeed, migration is increasingly connected to the transnational provision of services. This is the result of three kinds of factors: developments in the European Court of Justice’s (ECJ) case law; legislative initiatives in the EU; and the GATS. Each one of these is considered in some detail below. The aim of the analysis which follows is to show the extent to which (legislative and judicial) policies aimed at the free provision of services actively affect migration conditions within the EU. The EC rules on the provision of services primarily affect the movement of EU nationals. As it will be shown below, however, third country nationals (TCNs) may also claim the benefits of the rules on services, either as recipients thereof or as employees of some EC undertaking which is providing services in another member state (posted workers).
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Mode of access: Internet.
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Includes bibliographical references.
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"The catalogue of Li Lung-mien's paintings and the bibliography have been omitted from this edition."
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Mode of access: Internet.
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Includes bibliography.
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"Chronological table": p. [xvii]-xxxvi.