Silver staining (Campbell-Switzer) of neuronal α-synuclein assemblies induced by multiple system atrophy and Parkinson's disease brain extracts in transgenic mice.

Synucleinopathies [Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA)] share filamentous α-synuclein assemblies in nerve cells and glial cells. We compared the abilities of brain extracts from MSA and PD patients to induce neuronal α-synuclein assembly and neurodegeneration following intracerebral injection in heterozygous mice transgenic for human mutant A53T α-synuclein. MSA extracts were more potent than PD extracts in inducing α-synuclein assembly and in causing neurodegeneration. MSA assemblies were Campbell-Switzer- and Gallyas-silver-positive, whereas PD assemblies were only Campbell-Switzer-positive, in confirmation of previous findings. However, induced α-synuclein inclusions were invariably Campbell-Switzer-positive and Gallyas-negative, irrespective of whether MSA or PD brain extracts were injected. The α-synuclein inclusions of non-injected homozygous mice transgenic for A53T α-synuclein were also Campbell-Switzer-positive and Gallyas-negative. These findings demonstrate that transgene expression and its intracellular environment dominated over the silver staining properties of the conformers of assembled α-synuclein

Manifesto: Reconsideração do Inglês como Língua Franca em Contextos Acadêmico-Científicos [Rethinking English as a Lingua Franca in Scientific-Academic Contexts]

Buscamos discutir alguns pressupostos sobre o uso do inglês como “língua franca” em contextos acadêmico-científicos, identificar o impacto destes pressupostos nas trajetórias de produção e recepção de conhecimentos, e legitimar o uso de múltiplas línguas para a troca acadêmica transnacional. Propomos dez princípios: o uso do inglês quanto “língua franca” acadêmico-científica não sempre promove a inclusão; uma suposta “língua franca” acadêmicocientífica pode atuar como língua de dominação; uma política de inglês como “língua franca” pode desincentivar as traduções e limitar a participação; as políticas que posicionam o inglês como a “língua franca” acadêmico-científica contemporânea podem sugerir que o conhecimento produzido em inglês é o único que existe; a imposição do inglês como suposta “língua franca” acadêmico-científica é uma manifestação da distribuição desigual da produção e recepção do conhecimento; as línguas/variedades funcionam como recursos potentes para a criação de conhecimento; a escolha de uma língua de publicação ou apresentação é um direito sociolinguístico; a escolha de uma língua de publicação ou apresentação é um ato político; os organizadores de congressos deveriam ter o direito de eleger qual(is) língua(s) fomentar; os organizadores e participantes em congressos deveriam ser criativos e atentos para incluir audiências tão diversas quanto possível. We aim to challenge assumptions made about the use of English as a “lingua franca” in scientific- academic contexts, identify the impact of such assumptions on trajectories of knowledge production and uptake, and legitimize the use of multiple languages for transnational scholarly exchange. We set out ten principles: Using English as a scientific-academic “lingua franca” does not always promote inclusion; A language positioned as a scientific-academic “lingua franca” can act as a language of domination; Positioning English as the “lingua franca” policy may discourage translations and exclude participation; Policies which position English as being the contemporary scientific-academic “lingua franca” may convey the idea that knowledge produced in English is the only knowledge that exists; The imposition of English as a presumed scientific-academic “lingua franca” is a manifestation of the unequal distribution of knowledge production and uptake; Languages/varieties function as powerful resources for knowledge making; Choosing a language for publishing or presenting is a sociolinguistic right; Choosing a language to publish or present in is a political act; Convention organizers should have the right to promote the language(s) of their choice; Convention organizers and scholars should be as creative and sensitive to including as diverse an audience as possible

Assembly of transgenic human P301S Tau is necessary for neurodegeneration in murine spinal cord

Abstract A pathological pathway leading from soluble monomeric to insoluble filamentous Tau is characteristic of many human neurodegenerative diseases, which also exhibit dysfunction and death of brain cells. However, it is unknown how the assembly of Tau into filaments relates to cell loss. To study this, we first used a mouse line transgenic for full-length human mutant P301S Tau to investigate the temporal relationship between Tau assembly into filaments, assessed using anti-Tau antibody AT100, and motor neuron numbers, in the lumbar spinal cord. AT100 immunoreactivity preceded nerve cell loss. Murine Tau did not contribute significantly to either Tau aggregation or neurodegeneration. To further study the relevance of filament formation for neurodegeneration, we deleted hexapeptides 275VQIINK280 and 306VQIVYK311, either singly or in combination, from human 0N4R Tau with the P301S mutation. These hexapeptides are essential for the assembly of Tau into filaments. Homozygous mice transgenic for P301S Tau with the hexapeptide deletions, which expressed Tau at a similar level to the heterozygous line transgenic for P301S Tau, had a normal lifespan, unlike mice from the P301S Tau line. The latter had significant levels of sarkosyl-insoluble Tau in brain and spinal cord, and exhibited neurodegeneration. Mice transgenic for P301S Tau with the hexapeptide deletions failed to show significant levels of sarkosyl-insoluble Tau or neurodegeneration. Recombinant P301S Tau with the hexapeptide deletions failed to form β-sheet structure and filaments following incubation with heparin. Taken together, we conclude that β-sheet assembly of human P301S Tau is necessary for neurodegeneration in transgenic mice

Rethinking English as a lingua franca in scientific-academic contexts. A position statement.

We aim to challenge assumptions made about the use of English as a “lingua franca” in scientific-academic contexts, identify the impact of such assumptions on trajectories of knowledge production and uptake, and legitimize the use of multiple languages for transnational scholarly exchange. We set out ten principles: Using English as a scientific-academic “lingua franca” does not always promote inclusion; A language positioned as a scientific-academic “lingua franca” can act as a language of domination; Positioning English as the “lingua franca” policy may discourage translations and exclude participation; Policies which position English as being the contemporary scientific-academic “lingua franca” may convey the idea that knowledge produced in English is the only knowledge that exists; The imposition of English as a presumed scientific-academic “lingua franca” is a manifestation of the unequal distribution of knowledge production and uptake; Languages/varieties function as powerful resources for knowledge making; Choosing a language for publishing or presenting is a sociolinguistic right; Choosing a language to publish or present in is a political act; Convention organizers should have the right to promote the language(s) of their choice; Convention organizers and scholars should be as creative and sensitive to including as diverse an audience as possible