134 research outputs found
Oppida, agglomerations and suburbia: The Bibracte environs and new perspectives on Late Iron Age urbanism in central-eastern France
This paper explores the nature and chronology of La Tène and early Roman unenclosed agglomerations in central-eastern France. It has been prompted by the discovery of a c. 115 ha La Tène D2b/Augustan (c. 50 bc to ad 15) site close to Bibracte in the Morvan, located around the source of the River Yonne. This complex provides a new perspective on the chronology and role of Late La Tène and early Roman unenclosed settlements, adding further complexity to the story of the development of Late La Tène oppida. It indicates that these ‘agglomerations’ followed remarkably varied chronological trajectories, raising important issues concerning the nature of landscape and social change at the end of the Iron Age
Pygomelia or supernumerary limbs in a crossbred calf
A crossbred (Sindhi × local indigenous) calf that was 12 days old was admitted to the Teaching Veterinary Hospital, Chittagong Government Veterinary College, Bangladesh, with two accessory hind limbs attached to the pelvic region in between the hind legs. This was clinically identified as a congenital anomaly popularly called pygomelia. The pygomelia was successfully corrected by surgical excisions
Skeletal muscle hypertrophy rewires glucose metabolism: an experimental investigation and systematic review
BACKGROUND: Proliferating cancer cells shift their metabolism towards glycolysis, even in the presence of oxygen, to especially generate glycolytic intermediates as substrates for anabolic reactions. We hypothesize that a similar metabolic remodelling occurs during skeletal muscle hypertrophy. METHODS: We used mass spectrometry in hypertrophying C2C12 myotubes in vitro and plantaris mouse muscle in vivo and assessed metabolomic changes and the incorporation of the [U-13C6]glucose tracer. We performed enzyme inhibition of the key serine synthesis pathway enzyme phosphoglycerate dehydrogenase (Phgdh) for further mechanistic analysis and conducted a systematic review to align any changes in metabolomics during muscle growth with published findings. Finally, the UK Biobank was used to link the findings to population level. RESULTS: The metabolomics analysis in myotubes revealed insulin-like growth factor-1 (IGF-1)-induced altered metabolite concentrations in anabolic pathways such as pentose phosphate (ribose-5-phosphate/ribulose-5-phosphate: +40%; P = 0.01) and serine synthesis pathway (serine: -36.8%; P = 0.009). Like the hypertrophy stimulation with IGF-1 in myotubes in vitro, the concentration of the dipeptide l-carnosine was decreased by 26.6% (P = 0.001) during skeletal muscle growth in vivo. However, phosphorylated sugar (glucose-6-phosphate, fructose-6-phosphate or glucose-1-phosphate) decreased by 32.2% (P = 0.004) in the overloaded muscle in vivo while increasing in the IGF-1-stimulated myotubes in vitro. The systematic review revealed that 10 metabolites linked to muscle hypertrophy were directly associated with glycolysis and its interconnected anabolic pathways. We demonstrated that labelled carbon from [U-13C6]glucose is increasingly incorporated by ~13% (P = 0.001) into the non-essential amino acids in hypertrophying myotubes, which is accompanied by an increased depletion of media serine (P = 0.006). The inhibition of Phgdh suppressed muscle protein synthesis in growing myotubes by 58.1% (P < 0.001), highlighting the importance of the serine synthesis pathway for maintaining muscle size. Utilizing data from the UK Biobank (n = 450 243), we then discerned genetic variations linked to the serine synthesis pathway (PHGDH and PSPH) and to its downstream enzyme (SHMT1), revealing their association with appendicular lean mass in humans (P < 5.0e-8). CONCLUSIONS: Understanding the mechanisms that regulate skeletal muscle mass will help in developing effective treatments for muscle weakness. Our results provide evidence for the metabolic rewiring of glycolytic intermediates into anabolic pathways during muscle growth, such as in serine synthesis
Two-proton correlations from 158 AGeV Pb+Pb central collisions
The two-proton correlation function at midrapidity from Pb+Pb central
collisions at 158 AGeV has been measured by the NA49 experiment. The results
are compared to model predictions from static thermal Gaussian proton source
distributions and transport models RQMD and VENUS. An effective proton source
size is determined by minimizing CHI-square/ndf between the correlation
functions of the data and those calculated for the Gaussian sources, yielding
3.85 +-0.15(stat.) +0.60-0.25(syst.) fm. Both the RQMD and the VENUS model are
consistent with the data within the error in the correlation peak region.Comment: RevTeX style, 6 pages, 4 figures, 1 table. More discussion are added
about the structure on the tail of the correlation function. The systematic
error is revised. To appear in Phys. Lett.
Event-by-event fluctuations of average transverse momentum in central Pb+Pb collisions at 158 GeV per nucleon
We present first data on event-by-event fluctuations in the average
transverse momentum of charged particles produced in Pb+Pb collisions at the
CERN SPS. This measurement provides previously unavailable information allowing
sensitive tests of microscopic and thermodynamic collision models and to search
for fluctuations expected to occur in the vicinity of the predicted QCD phase
transition. We find that the observed variance of the event-by-event average
transverse momentum is consistent with independent particle production modified
by the known two-particle correlations due to quantum statistics and final
state interactions and folded with the resolution of the NA49 apparatus. For
two specific models of non-statistical fluctuations in transverse momentum
limits are derived in terms of fluctuation amplitude. We show that a
significant part of the parameter space for a model of isospin fluctuations
predicted as a consequence of chiral symmetry restoration in a non-equilibrium
scenario is excluded by our measurement.Comment: 6 pages, 2 figures, submitted to Phys. Lett.
The NA49 large acceptance hadron detector
The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large volume TPCs for tracking and particle identification via . TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions
Hadronic Expansion Dynamics in Central Pb+Pb Collisions at 158 GeV per Nucleon
Two-particle correlation functions of negative hadrons over wide phase space, and transverse mass spectra of negative hadrons and deuterons near mid-rapidity have been measured in central Pb+Pb collisions at 158 GeV per nucleon by the NA49 experiment at the CERN SPS. A novel Coulomb correction procedure for the negative two-particle correlations is employed making use of the measured oppositely charged particle correlation. Within an expanding source scenario these results are used to extract the dynamic characteristics of the hadronic source, resolving the ambiguities between the temperature and transverse expansion velocity of the source, that are unavoidable when single and two particle spectra are analysed separately. The source shape, the total duration of the source expansion, the duration of particle emission, the freeze-out temperature and the longitudinal and transverse expansion velocities are deduced
Gamma ray astrophysics: the EGRET results
Cosmic gamma rays provide insight into some of the most dynamic processes in
the Universe. At the dawn of a new generation of gamma-ray telescopes, this
review summarizes results from the Energetic Gamma Ray Experiment Telescope
(EGRET) on the Compton Gamma Ray Observatory, the principal predecessor mission
studying high-energy photons in the 100 MeV energy range. EGRET viewed a
gamma-ray sky dominated by prominent emission from the Milky Way, but featuring
an array of other sources, including quasars, pulsars, gamma-ray bursts, and
many sources that remain unidentified. A central feature of the EGRET results
was the high degree of variability seen in many gamma-ray sources, indicative
of the powerful forces at work in objects visible to gamma-ray telescopes.Comment: 23 pages, 24 figure
Abstracts of presentations on plant protection issues at the xth international congress of virology: August 11-16, 1996 Binyanei haOoma, Jerusalem Iarael part 3(final part)
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