41 research outputs found
Search for a new gauge boson in the Experiment (APEX)
We present a search at Jefferson Laboratory for new forces mediated by
sub-GeV vector bosons with weak coupling to electrons. Such a
particle can be produced in electron-nucleus fixed-target scattering and
then decay to an pair, producing a narrow resonance in the QED trident
spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV,
found no evidence for an reaction, and set an upper limit of
. Our findings demonstrate that fixed-target
searches can explore a new, wide, and important range of masses and couplings
for sub-GeV forces.Comment: 5 pages, 5 figures, references adde
Electroexcitation of the at low momentum transfer
We report on new p measurements at the
resonance at the low momentum transfer region. The mesonic
cloud dynamics is predicted to be dominant and rapidly changing in this
kinematic region offering a test bed for chiral effective field theory
calculations. The new data explore the low dependence of the resonant
quadrupole amplitudes while extending the measurements of the Coulomb
quadrupole amplitude to the lowest momentum transfer ever reached. The results
disagree with predictions of constituent quark models and are in reasonable
agreement with dynamical calculations that include pion cloud effects, chiral
effective field theory and lattice calculations. The reported measurements
suggest that improvement is required to the theoretical calculations and
provide valuable input that will allow their refinements
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Search for three-nucleon short-range correlations in light nuclei
We present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive ^{4}He/^{3}He cross section ratio is observed to be both x and Q^{2} independent for 1.52, our data support the hypothesis that a previous claim of three-nucleon correlation dominance was an artifact caused by the limited resolution of the measurement. While 3N-SRCs appear to have an important contribution, our data show that isolating 3N-SRCs is significantly more complicated than for 2N-SRCs.United States. Department of Energy (Contract DE-AC05-06OR23177)United States. Department of Energy (Contract DE-AC02-06CH11357)United States. Department of Energy (Contract DE-FG02-96ER40950
Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the 4He(e,e'pN) Triple-Coincidence Reaction
We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn)
reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of
400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a
proton or neutron recoiling almost back to back to the missing momentum,
leaving the residual A=2 system at low excitation energy. These data were used
to identify two-nucleon short-range correlated pairs and to deduce their
isospin structure as a function of missing momentum in a region where the
nucleon-nucleon force is expected to change from predominantly tensor to
repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon
momentum distributions, but their abundance is reduced as the nucleon momentum
increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is
small and almost independent of the missing momentum in the range we studied.
Our data are compared with ab-initio calculations of two-nucleon momentum
distributions in 4He.Comment: 6 pages, 2 figure
Promosi Kesehatan dengan Media Audiovisual dan Non Audiovisual terhadap Perilaku Pencegahan Stunting pada Remaja
Kualitas suatu remaja merupakan salah satu faktor yang dapat menentukan angka kejadian stunting. Kurangnya pemberian informasi yang benar tentang memeperisapkan pencegahan stunting sejak dini pada remaja terutama tentang persiapan masa 1000 Hari Pertama Kehidupan juga dapat meningkatkan resiko melahirkan anak dengan gangguan pertumbuhan hingga terjadinya stunting. Tujuan kegiatan pengabdian masyarakat untuk meningkatkan perilaku pencegahan stunting pada remaja desa Taban, Kecematan Jambe, Kabupaten Tangerang. Metode yang digunakan adalah penyampaian materi dan pengisisan kuesioner terkait pencegahan stunting. Kegiatan pengabdian masyarakat ini dilaksanakan penyuluhan kesehatan terkait pencegahan stunting dengan media audiovisual dan non-audiovisual. Hasil kegiatan adanya komitmen kepada peserta untuk melakukan penyebaran informasi kepada remaja lain dan adanya Perubahan perilaku remaja dari negatif menjadi positif terkait pencegahan stunting. Diharapkan dengan adanya peningkatan perilaku pada remaja maka dapat menekan angka kejadian stunting
Effect of prehabilitation in gastro-oesophageal adenocarcinoma: study protocol of a multicentric, randomised, control trial-the PREHAB study
INTRODUCTION: Perioperative chemotherapy is the gold standard treatment of the resectable gastro-oesophageal adenocarcinoma. However, 70% of patients cannot receive the complete sequence because of a postoperative complication or a decrease in functional and nutritional reserves. Recently, a new concept appeared in digestive surgery: prehabilitation. This interventional process consists of patient preparation, between surgical consultation and surgery, and is based on 3 components: (1) physical management, (2) nutritional care and (3) psychological care. Prehabilitation should decrease postoperative complications and improve nutritional and physical status during the preoperative and postoperative periods. Therefore, it is becoming essential to evaluate the effect of prehabilitation, compared to conventional care, on the percentage of patients reaching the complete oncological treatment.METHODS AND ANALYSIS: The PREHAB trial aimed to evaluate the efficacy of prehabilitation compared to conventional care, in patients with gastro-oesophageal cancer with perioperative chemotherapy. This trial is a prospective, randomised, controlled, open-blind and interventional study in 4 centres. Patients (n=60 per group) will be randomly assigned for management with either prehabilitation or conventional care. The primary outcome is the percentage of patients reaching the complete oncological treatment decided in a multidisciplinary tumour board. The secondary outcomes are the postoperative morbidity, disease-free survival, overall survival, feasibility of the protocol, length of stay, variation of the functional reserve after the preoperative chemotherapy (defined by the VO2peak, ventilatory threshold and 6-min walk test), preoperative and postoperative nutritional status, preoperative anxiety, quality of life, 30-day and 90-day mortality and cumulative dose of cytotoxic treatment receivedETHICS AND DISSEMINATION: The study was approved by an independent medical ethics committee (IRB00008526, CPP Sud-Est VI, Clermont-Ferrand, France) and by the competent French authority (ANSM, Saint Denis, France) and registered on Clinicaltrial.gov. The results will be disseminated in a peer-reviewed journalTRIAL REGISTRATION NUMBER: NCT02780921
Discovery of compounds blocking the proliferation of Toxoplasma gondii and Plasmodium falciparum in a chemical space based on piperidinyl-benzimidazolidinone analogs.
International audience: A piperidinyl-benzimidazolidinone scaffold has been found in the structure of different inhibitors of membrane glycerolipid metabolism, acting on enzymes manipulating diacylglycerol or phosphatidic acid. Screening a focus library of piperidinyl-benzimidazolidinone analogs might therefore identify compounds acting against infectious parasites. We first evaluated the in vitro effects of (S)-2-(dibenzylamino)-3-phenylpropyl 4-(1,2-dihydro-2-oxobenzo[d]imidazol-3-yl)piperidine-1-carboxylate (compound 1) on Toxoplasma gondii and Plasmodium falciparum. In T. gondii, motility and apical complex integrity appeared unaffected, whereas cell division was inhibited at concentrations of compound 1 in the micromolar range. In P. falciparum, proliferation of erythrocytic stages was inhibited, without any delayed death phenotype. We then explored a library of 250 analogs in two steps. We selected 114 compounds with an IC50 cutoff of 2 μM on at least one species and determined in vitro selectivity indexes (SI), based on toxicity against K-562 human cells. We identified compounds with high gains in IC50 (in the 100 nM range) and SI (up to 1,000-2,000). Isobole analyses of two of the most active compounds against P. falciparum indicated that their interaction with artemisin was additive. We propose structure activity relationship (SAR) models, which will be useful for the design of probes to identify the compounds' target(s), and optimizations for mono- or combined-therapeutic strategies