189 research outputs found

    Polymer Chemistry in Living Cells

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    Localization of neurones expressing the gap junction protein Connexin45 within the adult spinal dorsal horn: a study using Cx45-eGFP reporter mice.

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    Connexin (Cx) proteins localized to neuronal and glial syncytia provide the ultrastructural components for intercellular communication via gap junctions. In this study, a Cx45 reporter mouse model in which the Cx45 coding sequence is substituted for enhanced green fluorescent protein (eGFP) was used to characterize Cx45 expressing neurones within adult mouse spinal cord. eGFP-immunoreactive (eGFP-IR) cells were localized at all rostro-caudal levels to laminae I-III of the dorsal horn (DH), areas associated with nociception. The neuronal rather than glial phenotype of these cells in DH was confirmed by co-localisation of eGFP-IR with the neuronal marker NeuN. Further immunohistochemical studies revealed that eGFP-IR interneurones co-express the calcium-binding protein calbindin, and to a lesser extent calretinin. In contrast, eGFP-IR profiles did not co-localize with either parvalbumin or GAD-67, both of which are linked to inhibitory interneurones. Staining with the primary afferent markers isolectin-B4 (IB4) and calcitonin gene-related peptide revealed that eGFP-IR somata within laminae I-III receive close appositions from the former, presumed non-peptidergic nociceptive afferents of peripheral origin. The presence of 5-HT terminals in close apposition to eGFP-IR interneuronal somata suggests modulation via descending pathways. These data demonstrate a highly localized expression of Cx45 in a population of interneurones within the mouse superficial dorsal horn. The implications of these data in the context of the putative role of Cx45 and gap junctions in spinal somatosensory processing and pain are discussed

    The Political De-Determination of Legal Rules and the Contested Meaning of the ‘No Bailout’ Clause

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    Traditional debates on legal theory have devoted a great deal of attention to the question of the determinacy of legal rules. With the aid of social sciences and linguistics, this article suggests a way out of the ‘determinate-indeterminate’ dichotomy that has dominated the academic debate on the topic so far. Instead, a dynamic approach is proposed, in which rules are deemed to undergo processes of political ‘de-determination’ and ‘re-determination’. To illustrate this, the article uses the example of Art. 125 of the Treaty on the Functioning of the European Union, the ‘no bailout’ provision, which played a major role in the management of the Euro-crisis. As will be shown, with the start of the crisis, this provision, whose meaning was once scarcely controversial, became the object of intense interpretative disagreement. As it became politically relevant, the rule also became the site of interpretative competitions, until the intervention of the European Court of Justice disambiguated and redefined its meaning

    Ty1 integrase overexpression leads to integration of non-Ty1 DNA fragments into the genome of Saccharomyces cerevisiae

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    The integrase of the Saccharomyces cerevisiae retrotransposon Ty1 integrates Ty1 cDNA into genomic DNA likely via a transesterification reaction. Little is known about the mechanisms ensuring that integrase does not integrate non-Ty DNA fragments. In an effort to elucidate the conditions under which Ty1 integrase accepts non-Ty DNA as substrate, PCR fragments encompassing a selectable marker gene were transformed into yeast strains overexpressing Ty1 integrase. These fragments do not exhibit similarity to Ty1 cDNA except for the presence of the conserved terminal dinucleotide 5′-TG-CA-3′. The frequency of fragment insertion events increased upon integrase overexpression. Characterization of insertion events by genomic sequencing revealed that most insertion events exhibited clear hallmarks of integrase-mediated reactions, such as 5 bp target site duplication and target site preferences. Alteration of the terminal dinucleotide abolished the suitability of the PCR fragments to serve as substrates. We hypothesize that substrate specificity under normal conditions is mainly due to compartmentalization of integrase and Ty cDNA, which meet in virus-like particles. In contrast, recombinant integrase, which is not confined to virus-like particles, is able to accept non-Ty DNA, provided that it terminates in the proper dinucleotide sequence

    A systematic autopsy survey of human infant bridging veins

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    In the first years of life, subdural haemorrhage (SDH) within the cranial cavity can occur through accidental and non-accidental mechanisms as well as from birth-related injury. This type of bleeding is the most common finding in victims of abusive head trauma (AHT). Historically, the most frequent cause of SDHs in infancy is suggested to be traumatic damage to bridging veins traversing from the brain to the dural membrane. However, several alternative hypotheses have been suggested for the cause and origin of subdural bleeding. It has also been suggested by some that bridging veins are too large to rupture through the forces associated with AHT. To date, there have been no systematic anatomical studies on infant bridging veins. During 43 neonatal, infant and young child post-mortem examinations, we have mapped the locations and numbers of bridging veins onto a 3D model of the surface of a representative infant brain. We have also recorded the in situ diameter of 79 bridging veins from two neonatal, one infant and two young children at post-mortem examination. Large numbers of veins, both distant from and directly entering the dural venous sinuses, were discovered travelling between the brain and dural membrane, with the mean number of veins per brain being 54.1 and the largest number recorded as 94. The mean diameter of the bridging veins was 0.93 mm, with measurements ranging from 0.05 to 3.07 mm. These data demonstrate that some veins are extremely small and subjectively, and they appear to be delicate. Characterisation of infant bridging veins will contribute to the current understanding of potential vascular sources of subdural bleeding and could also be used to further develop computational models of infant head injury

    Unorthodoxy in legislation: The Hungarian experience

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    This paper deals with legal unorthodoxy. The main idea is to study the so-called unorthodox taxes Hungary has adopted in recent years. The study of unorthodox taxes will be preceded by a more general discussion of how law is made under unorthodoxy, and what are the special features of unorthodox legal policy. Unorthodoxy challenges equality before the law and is critical towards mass democracies. It also raises doubts on the operability of the rule of law, relying on personal skills, or loyalty, rather than on impersonal mechanisms arising from checks and balances as developed by the division of political power. Besides, for lack of legal suppositions, legislation suffers from casuistry and regulatory capture
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