Search results for "Darkness"
showing 10 items of 60 documents
Evidence for synergistic and complementary roles of Bassoon and darkness in organizing the ribbon synapse
2012
Abstract Ribbon synapses are tonically active high-throughput synapses. The performance of the ribbon synapse is accomplished by a specialization of the cytomatrix at the active zone (CAZ) referred to as the synaptic ribbon (SR). Progress in our understanding of the structure–function relationship at the ribbon synapse has come from observations that, in photoreceptors lacking a full-size scaffolding protein Bassoon ( Bsn Δ Ex 4 / 5 ), dissociation of SRs coincides with perturbed signal transfer. The aim of the present study has been to elaborate the role of Bassoon as a structural organizer of the ribbon synapse and to differentiate it with regard to the ambient lighting conditions. The ul…
L'Orchestra di Auschwitz. Inchiesta su Alma Rosé
2023
Il libro è un'inchiesta sulla vita e il tempo di Alma Rosé (1906-1944), nipote di Gustav Mahler, debuttante e ragazza alla moda fra gli anni Venti e Trenta del secolo scorso, violinista il cui talento matura – paradossalmente – mentre l’ombra del nazismo si dispiega sull’Europa e infine direttrice dell’orchestra di Auschwitz. in un’epoca in cui la carriera del direttore d’orchestra era declinata soltanto al maschile. Giunta ad Auschwitz nell’estate 1943 e assegnata dapprima al Block degli esperimenti medici, Alma riuscì in breve tempo a diventare – nel piccolo mondo terribile del Lager – una specie di celebrità: ed è in quelle tenebre, d’altronde, che si svolge l’atto finale del dramma, oss…
Lutter contre la pollution lumineuse
2019
La dégradation de l’obscurité sous l’effet des usages de lumière artificielle nocturne dans et aux abords des infrastructures humaines est appelée pollution lumineuse. Liée à l’urbanisation, cette pollution déborde les espaces urbains pour affecter les espaces ruraux et les aires protégées. La lutte contre la pollution lumineuse s’organise dans plusieurs pays, dans lesquels des territoires expérimentent des politiques environnementales de protection de l’obscurité. L’enjeu porte à la fois sur la préservation de la biodiversité et la transition énergétiques. En France, quelques territoires ruraux pionniers expérimentent des dispositifs intégrant ce double enjeu. Deux d’entre eux constituent …
Genome-wide adaptive complexes to underground stresses in blind mole rats Spalax
2014
The blind mole rat (BMR), Spalax galili, is an excellent model for studying mammalian adaptation to life underground and medical applications. The BMR spends its entire life underground, protecting itself from predators and climatic fluctuations while challenging it with multiple stressors such as darkness, hypoxia, hypercapnia, energetics and high pathonecity. Here we sequence and analyse the BMR genome and transcriptome, highlighting the possible genomic adaptive responses to the underground stressors. Our results show high rates of RNA/DNA editing, reduced chromosome rearrangements, an over-representation of short interspersed elements (SINEs) probably linked to hypoxia tolerance, degene…
Una storia italiana: Giorgio e Isabella
2018
Si tratta, qui, della storia di due italiani dalla “pelle scura” raccontata, per Giorgio Marincola, da Carlo Costa e Lorenzo Teodonio in Razza partigiana e, per la sorella Isabella, da Wu Ming 2 e Antar Mohamed in Timira. Romanzo meticcio. Le loro vicende, così come molti altri aspetti della nostra storia coloniale, neocoloniale e postcoloniale, sono riemerse dal buio nel quale erano state occultate solo nell’ultimo quindicennio, grazie alla riapertura degli archivi che ha permesso di ridiscutere molti degli aspetti che nelle pagine di Storia, così come in quelle letterarie, erano stati raccontati in altro modo. I due testi, che hanno inevitabilmente finito per incontrarsi e che potremmo in…
Specific sequence elements in the 5′ untranslated regions of rbcL and atpB gene mRNAs stabilize transcripts in the chloroplast of Chlamydomonas reinh…
2001
Using a series of point mutations in chimeric reporter gene constructs consisting of the 5' regions of the Chlamydomonas chloroplast rbcL or atpB genes fused 5' to the coding sequence of the bacterial uidA (GUS) gene, RNA-stabilizing sequence elements were identified in vivo in the 5' untranslated regions (5' UTRs) of transcripts of the chloroplast genes rbcL and atpB in Chlamydomonas reinhardtii. In chimeric rbcL 5' UTR:GUS transcripts, replacement of single nucleotides in the 10-nt sequence 5'-AUUUCCGGAC-3', extending from positions +38 to +47 relative to the transcripts' 5' terminus, shortened transcript longevity and led to a reduction in transcript abundance of more than 95%. A similar…
The starry sky, a territorial commons?
2021
International audience; Flagstaff, Arizona, United States, April 15, 1958: the city council adopts the ordinance n°440 which aims at “preventing a rapid deterioration of the visibility of the starry sky”. This regulation results from the mobilization of the Lowell Observatory astronomers against certain public lighting devices. Through this political act, the elected officials place their city at the epicenter of an emergent international movement: the ‘Dark-sky movement’. The first replica of this movement is felt in 1972 in Tucson, Arizona. From a discomfort perceived by astronomers from the Lowell and Kitt Peak observatories, the idea of ‘light pollution’ emerges and begins to spread thr…
Study of locomotion response and development in zebrafish (Danio rerio) embryos and larvae exposed to enniatin A, enniatin B, and beauvericin.
2021
Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate food and feed resources, and are capable of inducing a wide range of toxicity. Here, we studied the developmental and behavioral toxicity in zebrafish (Danio rerio) embryos and larvae exposed to three mycotoxins: beauvericin (BEA), Enniatin A (ENN A), and Ennitain B (ENN B). Zebrafish embryos were collected after fertilization, treated individually from 1 to 6 dpf with BEA at 8, 16, 32 and, 64 μM and for both enniatins at 3.12, 6.25, 12.5 and, 25 μM. Mixture of mycotoxins were assayed as follows: i) for BEA + ENN A and BEA + ENN B at [32 + 12.5] μM and [16 + 6.25] μM; ii) for ENN A + ENN B at [12.5 + 12.5] …
GENETIC AND PHYSIOLOGICAL STUDIES OF THE EFFECT OF LIGHT ON THE DEVELOPMENT OF THE MOSS, PHYSCOMITRELLA PATENS
1978
Abstract The germination of Physcomitrella patens spores only occurs when wet spores are exposed to light. Depending on their ripeness, spores require from 44 to 64 h illumination to bring about maximum germination. There is a lag period of about 15 h between the reception of sufficient light to elicit germination before germination can be observed. Wavelengths in the range 640-680 nm are much more effective in inducing germination than longer or shorter wavelengths, but far-red reversal of red light induction of germination has not been demonstrated. Light also has very marked effects on protonemal and gametophore development. In darkness, only caulonemata are produced, and these grow nega…
Response to ozone in two lettuce varieties on chlorophyll a fluorescence, photosynthetic pigments and lipid peroxidation.
2004
The effect of different O3 concentrations on two lettuce (Lactuca sativa L.) varieties (Valladolid and Morella) was investigated through chlorophyll (Chl) a fluorescence parameters, photosynthetic pigments (Chl a, b and total carotenoid), lipid peroxidation and crop yield. Ozone fumigation caused: a decrease in maximum quantum yield of photosystem II (PSII) photochemistry (Fv/Fm) in mature leaves, a reduction in the non-cyclic electron flow (phiPSII) and a lower capacity to reoxidize the QA pool (qP). These reductions were significant in the Valladolid var. but not in the Morella var. A significant decrease in Chl a, b and in the total carotenoids was observed in the Valladolid var. but not…