856 research outputs found
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
Investigation of the effect of initial states of medium-Mn steel on deformation behaviour under hot stamping conditions
Medium-Mn (MMn) steels have received much research attention recently because their low austenitisation temperature enables low-temperature hot stamping (LTHS). However, the effect of the initial state of the material on the hot stamping performance is still unknown. In this study, the effect of different initial states on the deformation behaviour of a typical MMn steel during uniaxial tensile testing under LTHS conditions (deformation at 500â600 °C under strain rates of 0.01â1 sâ1) are investigated using a Gleeble 3800 materials simulator; the final mechanical properties after austenitising and quenching are also examined. The microstructure of each material state before and after the LTHS heating cycle is characterised using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Of the three states investigated the hot rolled and annealed (HRA) state shows the best hot deformation performance represented by larger strain hardening exponent and higher total elongation, followed by the cold-rolled (CR) state, with the cold-rolled and annealed (CRA) state exhibiting the worst performance. The final mechanical properties, however, are very similar among the three states. In addition, the yield point phenomenon is found during hot deformation in both the CR and CRA states, and absent in the HRA state. The hot deformation behaviour has been discussed in terms of differences in microstructural properties, namely the grain size and its degree of heterogeneity
Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction
Reconnection of the self-generated magnetic fields in laser-plasma
interaction was first investigated experimentally by Nilson {\it et al.} [Phys.
Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a
solid target layer. An elongated current sheet (CS) was observed in the plasma
between the two laser spots. In order to more closely model magnetotail
reconnection, here two side-by-side thin target layers, instead of a single
one, are used. It is found that at one end of the elongated CS a fan-like
electron outflow region including three well-collimated electron jets appears.
The ( MeV) tail of the jet energy distribution exhibits a power-law
scaling. The enhanced electron acceleration is attributed to the intense
inductive electric field in the narrow electron dominated reconnection region,
as well as additional acceleration as they are trapped inside the rapidly
moving plasmoid formed in and ejected from the CS. The ejection also induces a
secondary CS
Study of the P-wave charmonium state \chi_{cJ} in \psi(2S) decays
The processes , and have been studied using a sample of produced
decays. We determine the total width of the to be
MeV. We present the first
measurement of the branching fraction , where the first error is statistical and the
second one systematic. Branching fractions of and
are also reported.Comment: 10 pages, revtex, 3 figures, 2 table
Measurement of the Total Cross Section for Hadronic Production by e+e- Annihilation at Energies between 2.6-5 Gev
Using the upgraded Beijing Spectrometer (BESII), we have measured the total
cross section for annihilation into hadronic final states at
center-of-mass energies of 2.6, 3.2, 3.4, 3.55, 4.6 and 5.0 GeV. Values of ,
, are determined.Comment: Submitted to Phys. Rev. Let
Measurement of decays to baryon pairs
A sample of 3.95M decays registered in the BES detector are used
to study final states containing pairs of octet and decuplet baryons. We report
branching fractions for , ,
, ,
, ,
, and . These results
are compared to expectations based on the SU(3)-flavor symmetry, factorization,
and perturbative QCD.Comment: 22 pages, 21 figures, 4 table
Measurement of the Inclusive Charm Cross Section at 4.03 GeV and 4.14 GeV
The cross section for charmed meson production at and 4.14
GeV has been measured with the Beijing Spectrometer. The measurement was made
using 22.3 of data collected at 4.03 GeV and 1.5
of data collected at 4.14 GeV. Inclusive observed cross sections for
the production of charged and neutral D mesons and momentum spectra are
presented. Observed cross sections were radiatively corrected to obtain tree
level cross sections. Measurements of the total hadronic cross section are
obtained from the charmed meson cross section and an extrapolation of results
from below the charm threshold.Comment: 11 pages, 13 figures. The top level tex file is paper.tex. It builds
the paper from other tex files in this .tar and the .eps file
A Unified Approach to the Classical Statistical Analysis of Small Signals
We give a classical confidence belt construction which unifies the treatment
of upper confidence limits for null results and two-sided confidence intervals
for non-null results. The unified treatment solves a problem (apparently not
previously recognized) that the choice of upper limit or two-sided intervals
leads to intervals which are not confidence intervals if the choice is based on
the data. We apply the construction to two related problems which have recently
been a battle-ground between classical and Bayesian statistics: Poisson
processes with background, and Gaussian errors with a bounded physical region.
In contrast with the usual classical construction for upper limits, our
construction avoids unphysical confidence intervals. In contrast with some
popular Bayesian intervals, our intervals eliminate conservatism (frequentist
coverage greater than the stated confidence) in the Gaussian case and reduce it
to a level dictated by discreteness in the Poisson case. We generalize the
method in order to apply it to analysis of experiments searching for neutrino
oscillations. We show that this technique both gives correct coverage and is
powerful, while other classical techniques that have been used by neutrino
oscillation search experiments fail one or both of these criteria.Comment: 40 pages, 15 figures. Changes 15-Dec-99 to agree more closely with
published version. A few small changes, plus the two substantive changes we
made in proof back in 1998: 1) The definition of "sensitivity" in Sec. V(C).
It was inconsistent with our actual definition in Sec. VI. 2) "Note added in
proof" at end of the Conclusio
Measurements of the Cross Section for e+e- -> hadrons at Center-of-Mass Energies from 2 to 5 GeV
We report values of for 85 center-of-mass energies between
2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing
Electron-Positron Collider.Comment: 5 pages, 3 figure
Measurement of \psip Radiative Decays
Using 14 million psi(2S) events accumulated at the BESII detector, we report
first measurements of branching fractions or upper limits for psi(2S) decays
into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^-
pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\bar K^{*0}, gamma pi^+pi^-
p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with
the invariant mass of hadrons below 2.9GeV/c^2. We also report branching
fractions of psi(2S) decays into 2(pi^+pi^-) pi^0, omega pi^+pi^-, omega
f_2(1270), b_1^\pm pi^\mp, and pi^0 2(pi^+pi^-) K^+K^-.Comment: 5 pages, 4 figure
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