899 research outputs found
Microbial nitrogen cycling on the Greenland Ice Sheet
No full textNitrogen inputs and microbial nitrogen cycling were investigated along a 79 km transect into the Greenland Ice Sheet (GrIS) during the main ablation season in summer 2010. The depletion of dissolved nitrate and production of ammonium (relative to icemelt) in cryoconite holes on Leverett Glacier, within 7.5 km of the ice sheet margin, suggested microbial uptake and ammonification respectively. Positive in situ acetylene assays indicated nitrogen fixation both in a debris-rich 100 m marginal zone and up to 5.7 km upslope on Leverett Glacier (with rates up to 16.3 μmoles C<sub>2</sub>H<sub>4</sub> m<sup>−2</sup> day<sup>−1</sup>). No positive acetylene assays were detected > 5.7 km into the ablation zone of the ice sheet. Potential nitrogen fixation only occurred when concentrations of dissolved and sediment-bound inorganic nitrogen were undetectable. Estimates of nitrogen fluxes onto the transect suggest that nitrogen fixation is likely of minor importance to the overall nitrogen budget of Leverett Glacier and of negligible importance to the nitrogen budget on the main ice sheet itself. Nitrogen fixation is however potentially important as a source of nitrogen to microbial communities in the debris-rich marginal zone close to the terminus of the glacier, where nitrogen fixation may aid the colonization of subglacial and moraine-derived debris
Emprisonnement, déchéance et abandon : Fort-de-France vue par Alfred Alexandre = Imprisonment, Degradation and Abandoning : Fort-de-France Seen by Alfred Alexandre
No full textThis article analyses Alfred Alexandre’s novel Bord de Canal (2004), in which the capital of Martinique turnes into a setting for human decay. The description of squalid environments,
populated by human debris, shows the lack of interest by the administration in taking responsibility for the lot of the most deprived inhabitants. They end up confined to working-class areas in inhuman living conditions. Through an analysis of places symbolising this degraded and degrading urban environment, which is transformed into a place of social exclusion and persecution, the study shows the renewal of the literary treatment of the city by Alexandre, an author of the post-creolité.Cet article propose une analyse du roman d’Alfred Alexandre
Bord de Canal (2004) où la capitale de la Martinique se révèle
un théâtre de déchéance humaine : l’évocation de milieux sor-
dides habités par des loques humaines montre le manque d’in-
térêt de la part de l’administration pour s’assumer le sort des
habitants les plus démunis qui se trouvent finalement confi-
nés dans les quartiers populaires dans des conditions de vie
inhumaines. À travers l’analyse de lieux symboles de ce cadre
urbain dégradé et dégradant, qui se transforme en lieu d’ex-
clusion et de persécution sociales, l’étude montre le renouveau
du traitement littéraire de la ville chez Alexandre, auteur de la
post-créolité
Gamma band plasticity in sensory cortex is a signature of the strongest memory rather than memory of the training stimulus
No full textGamma oscillations (∼30-120Hz) are considered to be a reflection of coordinated neuronal activity, linked to processes underlying synaptic integration and plasticity. Increases in gamma power within the cerebral cortex have been found during many cognitive processes such as attention, learning, memory and problem solving in both humans and animals. However, the specificity of gamma to the detailed contents of memory remains largely unknown. We investigated the relationship between learning-induced increased gamma power in the primary auditory cortex (A1) and the strength of memory for acoustic frequency. Adult male rats (n=16) received three days (200 trials each) of pairing a tone (3.66 kHz) with stimulation of the nucleus basalis, which implanted a memory for acoustic frequency as assessed by associatively-induced disruption of ongoing behavior, viz., respiration. Post-training frequency generalization gradients (FGGs) revealed peaks at non-CS frequencies in 11/16 cases, likely reflecting normal variation in pre-training acoustic experiences. A stronger relationship was found between increased gamma power and the frequency with the strongest memory (peak of the difference between individual post- and pre-training FGGs) vs. behavioral responses to the CS training frequency. No such relationship was found for the theta/alpha band (4-15 Hz). These findings indicate that the strength of specific increased neuronal synchronization within primary sensory cortical fields can determine the specific contents of memory.Peer reviewedAuthor's Manuscript is available open access in PubMed Central: http://www.ncbi.nlm.nih.gov/pubmed/23669065
Increased photoreactivity of DOC by acidification: Implications for the carbon cycle in humic lakes
No full textEffects of ultraviolet (UV)-B radiation and acidification on pelagic carbon flux in a humic lake (dissolved organic carbon [DOC] similar to15 mg C L-1) were studied in a mesocosm experiment during the summer of 2000. Triplicate tanks (107 liters volume, 1 m high) were exposed to natural solar radiation, a daily extra dose of UV-B radiation, or kept dark. One set of tanks was submitted to a decrease in pH (from 5.7 to 4.7), and one set was kept at the natural pH level. During 70 d, water samples were taken regularly from the mesocosms for measurements of DOC, absorbance, dissolved inorganic carbon (DIC), and pH. Additionally, we regularly incubated samples to measure photooxidation rates, primary production, and community respiration. We found an increase in the photooxidation rates in the acidified mesocosms relative to ambient pH. The greater abiotic production of DIC (i.e., photooxidation) in acidified conditions could explain similar to27% of the decline in DOC in the same conditions. Laboratory experiments were done to test the effects of pH on the dissolved organic matter (DOM) photoreactivity. At lower pH values, we found both higher abiotic DIC production and specific absorbance fading, relative to neutral pH values in water from a humic lake. In a separate experiment, samples were exposed to prolonged irradiation under laboratory conditions, resulting in complete loss of absorptivity in the wavelengths between 290 and 400 nm. Decreases in DOC in the long-term exposure caused by photochemical mineralization were similar to45 and 55% of the initial pool for natural pH and acidified samples, respectively, at the end of the experiment. An increase in the dissolved organic matter photoreactivity by acidification could be an important mechanism to explain the increased water transparency and in-lake DOC removal in acid lakes found in several previous studies
Remodeling sensory cortical maps implants specific behavioral memory
No full textNeural mechanisms underlying the capacity of memory to be rich in sensory detail are largely unknown. A candidate mechanism is learning-induced plasticity that remodels the adult sensory cortex. Here, expansion in the primary auditory cortical (A1) tonotopic map of rats was induced by pairing a 3.66-kHz tone with activation of the nucleus basalis, mimicking the effects of natural associative learning. Remodeling of A1 produced de novo specific behavioral memory, but neither memory nor plasticity was consistently at the frequency of the paired tone, which typically decreased in A1 representation. Rather, there was a specific match between individual subjects' area of expansion and the tone that was strongest in each animal's memory, as determined by post-training frequency generalization gradients. These findings provide the first demonstration of a match between the artificial induction of specific neural representational plasticity and artificial induction of behavioral memory. As such, together with prior and present findings for detection, correlation and mimicry of plasticity with the acquisition of memory, they satisfy a key criterion for neural substrates of memory. This demonstrates that directly remodeling sensory cortical maps is sufficient for the specificity of memory formation.Peer reviewedAuthor's Manuscript is also available open access in PubMed Central: http://www.ncbi.nlm.nih.gov/pubmed/23639876
Against Fraud For Fame Reflected In Alexandre Dumas’s Novel The Black Tulip (1850): A Sociological Approach
No full textThis study aims to determine the fraud for fame in the novel The Black Tulip by using sociological approach. That was done by setting three goals: the first is to identify the fraud indicator in the literary work, the second is to describe how fraud to fame in the literary work, and the last is to know the reason Alexandre Dumas raised the issue of fraud to fame in the literary work. This type of research is qualitative research. In this method, the author uses two data types namely primary data and secondary data. The primary data is the study of The Black Tulip novel, written by Alexandre Dumas. Secondary data is data taken from biographies of authors, articles, books electronically, books and other sources that support the analysis. The first result of this study is to know the fraud for fame that reflected in The Black Tulip novel based on the indicators, that is cunning, slander, trick and dishonesty. The second is how fraud for fame describing in the literary work through the character and characterization, events, setting of place, and style. The last, the reason of Alexandre Dumas addressed fraud in the literary work is to make the reader know that the act of fraud to success is an incorrect act. In gaining success and fame, the most important thing is an honesty
Edição anotada e estudo das narrativas históricas de Alexandre Herculano situadas entre 1367 a 1433.
No full textThis thesis proposes a annotated edition and a study of the historical narratives of
Alexandre Herculano located between 1367-1433, Arras forum for Spain, The vault,
and Castle of Faria in this period include the reign of Ferdinand and D . John I. Such
narratives were published at the beginning of the Portuguese Romanticism initially in
journals of Portuguese journals then were gathered in volumes with other historical
narratives of the author, and published under the title Legends and Lore. This research
was developed from concern over the lack of this material in our academic context, it is
noteworthy that other works of Herculaneum are much more affordable and therefore
more known and studied, for example, the novels The Fool ( 1843), Eurico the priest
(1844), and the Monk Cistercian (1848). This annotated edition proposal, we intend
school player, college player, even the lay reader in general. Therefore, we intend to put
the scope of this public an issue with notes to assist them while reading these stories, to
have an enriched text with relevant information to clarify and enable a better
understanding of it.
Keywords: Historical Narratives; Annotated Edition; Alexandre Herculano.Esta dissertação apresenta uma proposta de edição anotada e um estudo das narrativas
históricas de Alexandre Herculano situadas entre 1367 a 1433, Arras por Foro de
Espanha, A Abóbada, e O Castelo de Faria. A este período compreendem o reinado de
D. Fernando e D. João I. Tais narrativas foram publicadas no início do Romantismo
português, inicialmente, em periódicos de revistas portuguesas, em seguida, foram
reunidas em volumes com outras narrativas históricas deste autor, e publicadas sob o
título de Lendas e Narrativas. Esta pesquisa desenvolveu-se a partir da inquietação
suscitada pela carência deste material em nosso contexto acadêmico. Vale ressaltar, que
outras obras de Herculano são bem mais acessíveis, e por consequência mais conhecidas
e estudadas, como, por exemplo, os romances O Bobo (1843), Eurico o Presbítero
(1844), e O Monge de Cister (1848). Nesta proposta de edição anotada, temos em vista
o leitor escolar, o leitor universitário, até mesmo, o leitor leigo em geral. Por isso,
pretendemos colocar ao alcance deste público uma edição com anotações que os
auxiliem durante a leitura destas narrativas, ao terem um texto enriquecido com
informações pertinentes que esclareçam e possibilitem sua compreensão.
Palavras Chave: Narrativas históricas; Edição anotada; Alexandre Herculano
Entrevista com Alexandre Barbosa de Souza
No full textAlexandre Barbosa de Souza is a writer, poet, editor and translator. He was editor at Editora 34, Cosac Naify, and Biblioteca Azul. He is the author of Azul Escuro (Hedra, 2003), Autobiografia de um super-herói (Hedra, 2003), and Livro geral (Companhia das Letras, 2013). Also, he translates from English, French and Spanish. Among his translations we can cite: Moby Dick (Cosac Naify, 2008), by Herman Melville; A crônica dos Wapshot (Companhia das Letras, 2011), by John Cheever; Orgulho e Preconceito (Companhia das Letras, 2011) and Razão e Sensibilidade (Companhia das Letras, 2012), by Jane Austen; Alice através do espelho (SESI-SP, 2018); Só garotos (Companhia das Letras, 2018), by Patti Smith; Anne de Green Gables (Editora Nova Fronteira, 2019), by L. M. Montegomery.Alexandre Barbosa de Souza é escritor, poeta, editor e tradutor. Foi editor na Editora 34, na Cosac Naify e na Biblioteca Azul. É autor de Azul Escuro (Hedra, 2003), Autobiografia de um super-herói (Hedra, 2003) e Livro geral (Companhia das Letras, 2013). Traduz do inglês, francês e espanhol. Entre suas traduções pode-se citar: Moby Dick (Cosac Naify, 2008), de Herman Melville; A crônica dos Wapshot (Companhia das Letras, 2011), de John Cheever; Orgulho e Preconceito (Companhia das Letras, 2011) e Razão e Sensibilidade (Companhia das Letras, 2012), de Jane Austen; Alice através do espelho (SESI-SP, 2018); Só garotos (Companhia das Letras, 2018), de Patti Smith; Anne de Green Gables (Editora Nova Fronteira, 2019), de L. M. Montegomery.
Entrevista com Alexandre Barbosa de Souza
No full textAlexandre Barbosa de Souza is a writer, poet, editor and translator. He was editor at Editora 34, Cosac Naify, and Biblioteca Azul. He is the author of Azul Escuro (Hedra, 2003), Autobiografia de um super-herói (Hedra, 2003), and Livro geral (Companhia das Letras, 2013). Also, he translates from English, French and Spanish. Among his translations we can cite: Moby Dick (Cosac Naify, 2008), by Herman Melville; A crônica dos Wapshot (Companhia das Letras, 2011), by John Cheever; Orgulho e Preconceito (Companhia das Letras, 2011) and Razão e Sensibilidade (Companhia das Letras, 2012), by Jane Austen; Alice através do espelho (SESI-SP, 2018); Só garotos (Companhia das Letras, 2018), by Patti Smith; Anne de Green Gables (Editora Nova Fronteira, 2019), by L. M. Montegomery.Alexandre Barbosa de Souza é escritor, poeta, editor e tradutor. Foi editor na Editora 34, na Cosac Naify e na Biblioteca Azul. É autor de Azul Escuro (Hedra, 2003), Autobiografia de um super-herói (Hedra, 2003) e Livro geral (Companhia das Letras, 2013). Traduz do inglês, francês e espanhol. Entre suas traduções pode-se citar: Moby Dick (Cosac Naify, 2008), de Herman Melville; A crônica dos Wapshot (Companhia das Letras, 2011), de John Cheever; Orgulho e Preconceito (Companhia das Letras, 2011) e Razão e Sensibilidade (Companhia das Letras, 2012), de Jane Austen; Alice através do espelho (SESI-SP, 2018); Só garotos (Companhia das Letras, 2018), de Patti Smith; Anne de Green Gables (Editora Nova Fronteira, 2019), de L. M. Montegomery.
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