63 research outputs found
Microwave neural processing and broadcasting with spintronic nano-oscillators
Can we build small neuromorphic chips capable of training deep networks with
billions of parameters? This challenge requires hardware neurons and synapses
with nanometric dimensions, which can be individually tuned, and densely
connected. While nanosynaptic devices have been pursued actively in recent
years, much less has been done on nanoscale artificial neurons. In this paper,
we show that spintronic nano-oscillators are promising to implement analog
hardware neurons that can be densely interconnected through electromagnetic
signals. We show how spintronic oscillators maps the requirements of artificial
neurons. We then show experimentally how an ensemble of four coupled
oscillators can learn to classify all twelve American vowels, realizing the
most complicated tasks performed by nanoscale neurons
High Abundance Proteins Depletion vs Low Abundance Proteins Enrichment: Comparison of Methods to Reduce the Plasma Proteome Complexity
BACKGROUND:
To date, the complexity of the plasma proteome exceeds the analytical capacity of conventional approaches to isolate lower abundance proteins that may prove to be informative biomarkers. Only complex multistep separation strategies have been able to detect a substantial number of low abundance proteins (<100 ng/ml). The first step of these protocols is generally the depletion of high abundance proteins by the use of immunoaffinity columns or, alternatively, the enrichment of by the use of solid phase hexapeptides ligand libraries.
METHODOLOGY/PRINCIPAL FINDINGS:
Here we present a direct comparison of these two approaches. Following either approach, the plasma sample was further fractionated by SCX chromatography and analyzed by RP-LC-MS/MS with a Q-TOF mass spectrometer. The depletion of the 20 most abundant plasma proteins allowed the identification of about 25% more proteins than those detectable following low abundance proteins enrichment. The two datasets are partially overlapping and the identified proteins belong to the same order of magnitude in terms of plasma concentration.
CONCLUSIONS/SIGNIFICANCE:
Our results show that the two approaches give complementary results. However, the enrichment of low abundance proteins has the great advantage of obtaining much larger amount of material that can be used for further fractionations and analyses and emerges also as a cheaper and technically simpler approach. Collectively, these data indicate that the enrichment approach seems more suitable as the first stage of a complex multi-step fractionation protocol
SUMO regulates p21Cip1 intracellular distribution and with p21Cip1 facilitates multiprotein complex formation in the nucleolus upon DNA damage
We previously showed that p21Cip1 transits through the nucleolus on its way from the nucleus to the cytoplasm and that DNA damage inhibits this transit and induces the formation of p21Cip1-containing intranucleolar bodies (INoBs). Here, we demonstrate that these INoBs also contain SUMO-1 and UBC9, the E2 SUMO-conjugating enzyme. Furthermore, whereas wild type SUMO-1 localized in INoBs, a SUMO-1 mutant, which is unable to conjugate with proteins, does not, suggesting the presence of SUMOylated proteins at INoBs. Moreover, depletion of the SUMO-conjugating enzyme UBC9 or the sumo hydrolase SENP2 changed p21Cip1 intracellular distribution. In addition to SUMO-1 and p21Cip1, cell cycle regulators and DNA damage checkpoint proteins, including Cdk2, Cyclin E, PCNA, p53 and Mdm2, and PML were also detected in INoBs. Importantly, depletion of UBC9 or p21Cip1 impacted INoB biogenesis and the nucleolar accumulation of the cell cycle regulators and DNA damage checkpoint proteins following DNA damage. The impact of p21Cip1 and SUMO-1 on the accumulation of proteins in INoBs extends also to CRM1, a nuclear exportin that is also important for protein translocation from the cytoplasm to the nucleolus. Thus, SUMO and p21Cip1 regulate the transit of proteins through the nucleolus, and that disruption of nucleolar export by DNA damage induces SUMO and p21Cip1 to act as hub proteins to form a multiprotein complex in the nucleolus
Une nouvelle méthode d’utilisation des mesures céphalométriques en orthodontie
Il est admis actuellement que la céphalométrie émanant des analyses
NordAméricaines de TWEED, STEINER et RICKETTS est remise en question. Le groupe
C.R.A.N.I.O.M. propose une nouvelle méthode d’utilisation des chiffres que l’on
peut considérer comme une aide raisonnable et raisonnée au diagnostic.
Ce club a analysé les données d’un échantillon des 83 jeunes adultes sans
traitement d’O.D.F. et en classe I dentaire.
La notion nouvelle la plus intéressante est celle de l’emploi
des valeurs extrêmes de chaque variable de cet échantillon. Ces
chiffres constituent des bornes très éloignées les unes des autres
: plus de 30° d’écart entre l’inclinaison incisive la plus vestibulée et celle
la plus lingualée (ou palatinée).
Ainsi pour ces dents les inclinaisons sont acceptable de 78 à 114° sur le plan
mandibulaire de Downs pour les incisives du bas, et de 97,5° à 130,1° sur le
plan de Francfort pour celles du haut. Le besoin de changement de position de
ces dents, demandé par un repositionnement céphalométrique abusif, est alors
nettement moins fréquent .
Pour cette raison, on observe beaucoup moins d’indications d’extractions de
prémolaires provoquées par les redressements céphalométriques imposés par les
analyses citées plus haut. Les mesures osseuses décrivent seulement des formes
qui ne constituent pas des anomalies mais décrivent une typologie
particulière.
Le C.R.A.N.I.O.M. précise que la place de la céphalométrie dans le dossier
orthodontique vient après celle de l’esthétique, de l’état
parodontal et de l’équilibre musculaire
Woodland bird response to landscape connectivity in an agriculture-dominated landscape: a functional community approach
Over the last 30 years, ecological networks have been deployed to reduce global biodiversity loss by enhancing landscape connectivity. Bird species dwelling in woodland habitats that are embedded in agriculture-dominated landscapes are expected to be particularly sensitive to the loss of connectivity. This study aimed to determine the role of landscape connectivity in woodland bird species richness, abundance, and community similarity in north-east Brittany (north-west France). An exhaustive woodland selection protocol was carried out to minimize the effects of woodland size on the response variables. Connectivity of the woodland and forest network in the study area was evaluated using graph-theory, accounting for matrix permeability, and a characteristic median natal dispersal distance at the community level based on the bird species pool recorded in the sampled woodlands. Information-theoretic model selection, controlling for woodland size in all the cases, depicted the response of woodland birds at the community level to the connectivity of agriculture-dominated landscapes. On average, the sampled woodlands (n = 25) contained 15.5 ± 2.4 bird species, with an abundance of 25.1 ± 3.9, and had highly similar bird communities (species composition and proportion); eight species represented 57% of total abundance and were present in at least 22 woodlands. The performance of models improved when using effective, rather than Euclidean, interpatch distances in the connectivity assessment. Landscape connectivity was only significantly related to similarity of proportional species composition. Large woodlands contained communities with more similar species proportions in an inhospitable agricultural landscape matrix than in a more permeable one. Woodland size was the most relevant factor determining species abundance, indicating that the bird population sizes are primarily proportional to the local habitat availability. Connectivity in relation to landscape matrix permeability did not seem to induce the flow of woodland-dependent bird species that are dominant in the community but rather of matrix-dwelling bird species that are less dependent on woodland patch area. In conclusion, both habitat conservation and restoration (i.e., amount and quality), in combination with permeable landscape structures (such as heterogeneous land cover mosaics), are advocated for community level conservation strategies
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