3,139 research outputs found
Cell-selective modulation of the Drosophila neuromuscular system by a neuropeptide
Neuropeptides can modulate physiological properties of neurons in a cell-specific manner. The present work examines whether a neuropeptide can also modulate muscle tissue in a cell-specific manner, using identified muscle cells in third instar larvae of fruit flies. DPKQDFMRFa, a modulatory peptide in the fruit fly Drosophila melanogaster, has been shown to enhance transmitter release from motor neurons and to elicit contractions by a direct effect on muscle cells. We report that DPKQDFMRFa causes a nifedipine-sensitive drop in input resistance in some muscle cells (6 and 7) but not others (12 and 13). The peptide also increased the amplitude of nerve-evoked contractions and compound excitatory junctional potentials (EJPs) to a greater degree in muscle cells 6 and 7 than 12 and 13. Knocking down FMRFa receptor (FR) expression separately in nerve and muscle indicate that both presynaptic and postsynaptic FR expression contributed to the enhanced contractions, but EJP enhancement was due mainly to presynaptic expression. Muscle-ablation showed that DPKQDFMRFa induced contractions and enhanced nerve-evoked contractions more strongly in muscle cells 6 and 7 than cells 12 and 13. In situ hybridization indicated that FR expression was significantly greater in muscle cells 6 and 7 than 12 and 13. Taken together, these results indicate that DPKQDFMRFa can elicit cell-selective effects on muscle fibres. The ability of neuropeptides to work in a cell-selective manner on neurons and muscle cells may help explain why so many peptides are encoded in invertebrate and vertebrate genomes
Radicellectomie sensitive partielle basée sur des observations cliniques : description des critères de décision et effet sur la marche des enfants avec paralysie cérébrale
Twenty-five years of selective dorsal rhizotomy based on clinical observations instead of intraoperative electrophysiological monitoring: The Sainte-Justine hospital experience
Commensurate-Incommensurate Magnetic Phase Transition in Magnetoelectric Single Crystal LiNiPO
Neutron scattering studies of single-crystal LiNiPO reveal a spontaneous
first-order commensurate-incommensurate magnetic phase transition. Short- and
long-range incommensurate phases are intermediate between the high temperature
paramagnetic and the low temperature antiferromagnetic phases. The modulated
structure has a predominant antiferromagnetic component, giving rise to
satellite peaks in the vicinity of the fundamental antiferromagnetic Bragg
reflection, and a ferromagnetic component giving rise to peaks at small
momentum-transfers around the origin at . The wavelength of the
modulated magnetic structure varies continuously with temperature. It is argued
that the incommensurate short- and long-range phases are due to
spin-dimensionality crossover from a continuous to the discrete Ising state.
These observations explain the anomalous first-order transition seen in the
magnetoelectric effect of this system
PCN59 COST OF MANAGEMENT OF BREAST CANCER WITH BRAIN METASTASES USING FRENCH HOSPITAL PATIENT CHAINING SYSTEM
Registration of ultrasound volumes based on Euclidean distance transform
During neurosurgical operations, surgeons can decide to acquire
intraoperative data to better proceed with the removal of a tumor. A valid
option is given by ultrasound (US) imaging, which can be easily obtained at
subsequent surgical stages, giving therefore multiple updates of the resection
cavity. To improve the efficacy of the intraoperative guidance, neurosurgeons
may benefit from having a direct correspondence between anatomical structures
identified at different US acquisitions. In this context, the commonly
available neuronavigation systems already provide registration methods, which
however are not enough accurate to overcome the anatomical changes happening
during resection. Therefore, our aim with this work is to improve the
registration of intraoperative US volumes. In the proposed methodology, first a
distance mapping of automatically segmented anatomical structures is computed
and then the transformed images are utilized in the registration step. Our
solution is tested on a public dataset of 17 cases, where the average landmark
registration error between volumes acquired at the beginning and at the end of
neurosurgical procedures is reduced from 3.55mm to 1.27mm
Influence of Multiple Light Scattering on PDV Measurements in Presence of Ejecta
Author Institution: French Alternative Energies and Atomic Energy Commission (CEA)Slides presented at the 2018 Photonic Doppler Velocimetry (PDV) Users Workshop, Drury Plaza Hotel, Santa Fe, New Mexico, May 16-18, 2018
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A platform for the discovery of new macrolide antibiotics.
The chemical modification of structurally complex fermentation products, a process known as semisynthesis, has been an important tool in the discovery and manufacture of antibiotics for the treatment of various infectious diseases. However, many of the therapeutics obtained in this way are no longer effective, because bacterial resistance to these compounds has developed. Here we present a practical, fully synthetic route to macrolide antibiotics by the convergent assembly of simple chemical building blocks, enabling the synthesis of diverse structures not accessible by traditional semisynthetic approaches. More than 300 new macrolide antibiotic candidates, as well as the clinical candidate solithromycin, have been synthesized using our convergent approach. Evaluation of these compounds against a panel of pathogenic bacteria revealed that the majority of these structures had antibiotic activity, some efficacious against strains resistant to macrolides in current use. The chemistry we describe here provides a platform for the discovery of new macrolide antibiotics and may also serve as the basis for their manufacture
Online Monitoring of the Osiris Reactor with the Nucifer Neutrino Detector
Originally designed as a new nuclear reactor monitoring device, the Nucifer
detector has successfully detected its first neutrinos. We provide the second
shortest baseline measurement of the reactor neutrino flux. The detection of
electron antineutrinos emitted in the decay chains of the fission products,
combined with reactor core simulations, provides an new tool to assess both the
thermal power and the fissile content of the whole nuclear core and could be
used by the Inter- national Agency for Atomic Energy (IAEA) to enhance the
Safeguards of civil nuclear reactors. Deployed at only 7.2m away from the
compact Osiris research reactor core (70MW) operating at the Saclay research
centre of the French Alternative Energies and Atomic Energy Commission (CEA),
the experiment also exhibits a well-suited configuration to search for a new
short baseline oscillation. We report the first results of the Nucifer
experiment, describing the performances of the 0.85m3 detector remotely
operating at a shallow depth equivalent to 12m of water and under intense
background radiation conditions. Based on 145 (106) days of data with reactor
ON (OFF), leading to the detection of an estimated 40760 electron
antineutrinos, the mean number of detected antineutrinos is 281 +- 7(stat) +-
18(syst) electron antineutrinos/day, in agreement with the prediction 277(23)
electron antineutrinos/day. Due the the large background no conclusive results
on the existence of light sterile neutrinos could be derived, however. As a
first societal application we quantify how antineutrinos could be used for the
Plutonium Management and Disposition Agreement.Comment: 22 pages, 16 figures - Version
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