125 research outputs found
The Arabidopsis cer26 mutant, like the cer2 mutant, is specifically affected in the very long chain fatty acid elongation process
Plant aerial organs are covered by cuticular waxes, which form a hydrophobic crystal layer that mainly serves as a waterproof barrier. Cuticular wax is a complex mixture of very long chain lipids deriving from fatty acids, predominantly of chain lengths from 26 to 34 carbons, which result from acyl-CoA elongase activity. The biochemical mechanism of elongation is well characterized; however, little is known about the specific proteins involved in the elongation of compounds with more than 26 carbons available as precursors of wax synthesis. In this context, we characterized the three Arabidopsis genes of the CER2-like family: CER2, CER26 and CER26-like . Expression pattern analysis showed that the three genes are differentially expressed in an organ- and tissue-specific manner. Using individual TDNA insertion mutants, together with a cer2 cer26 double mutant, we characterized the specific impact of the inactivation of the different genes on cuticular waxes. In particular, whereas the cer2 mutation impaired the production of wax components longer than 28 carbons, the cer26 mutant was found to be affected in the production of wax components longer than 30 carbons. The analysis of the acyl-CoA pool in the respective transgenic lines confirmed that inactivation of both genes specifically affects the fatty acid elongation process beyond 26 carbons. Furthermore, ectopic expression of CER26 in transgenic plants demonstrates that CER26 facilitates the elongation of the very long chain fatty acids of 30 carbons or more, with high tissular and substrate specificity
Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin
There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters
The Object of My Aggression: Sexual Objectification Increases Physical Aggression Towards Women
Objectification involves reducing someone to a sexual object, rather than seeing themas a full person. Despite numerous theoretical claims that people are more aggressivetoward the objectified, and empirical evidence that objectification is linked to highwillingness to aggress, rape proclivity, and aggressive attitudes, no research hasexamined a causal link between objectification and physical aggression, particularly inthe context of provocation. In two experiments, we examined this predicted link. InExperiment 1, using a 2 (objectification: no/yes) × 2 (provocation: no/yes) factorialbetween-subjects design, we investigated the effects of objectification, induced viabody focus during a face-to-face interaction, and provocation on physical aggressiontoward a female confederate. Our results revealed a significant main effect ofprovocation, a marginal main effect of objectification, and a significant interactionbetween these variables. In the absence of a provocation, focusing on a woman’s bodyincreased aggression toward her. Experiment 2 replicated Experiment 1 using a videoof a target woman instead of a face-to-face interaction. Again, our results showed asignificant two-way interaction between objectification and provocation, whereinobjectification increased aggression in the absence of provocation. Overall, thisresearch indicates that objectification can lead to heightened physical aggressiontoward objectified women
Separation of anomalous and synchrotron emissions using WMAP polarization data
The main goals of this study is to use the information from both WMAP
intensity and polarization data to do a separation of the Galactic components,
with a focus on the synchrotron and anomalous emissions. Our analysis is made
at 23 GHz where the signal-to-noise ratio is the highest and the estimate of
the CMB map is less critical. Our estimate of the synchrotron intensity is
based on an extrapolation of the Haslam 408 MHz data with a spatially varying
spectral index constrained by the WMAP 23 GHz polarization data and a
bi-symmetrical spiral model of the galactic magnetic field with a turbulent
part following a -5/3 power law spectrum. The 23 GHz polarization data are
found to be compatible with a magnetic field with a pitch angle p=-8.5 degrees
and an amplitude of the turbulent part of the magnetic field 0.57 times the
local value of the field, in agreement with what is found using rotation
measures of pulsars and polarized extinction by dust. The synchrotron spectral
index between 408 MHz and 23 GHz obtained from polarization data and our model
of the magnetic field has a mean value of Beta=-3.00 with a limited spatial
variation with a standard deviation of 0.06. When thermal dust, free-free and
synchrotron are removed from the WMAP intensity data, the residual anomalous
emission is highly correlated with thermal dust emission with a spectrum in
agreement with spinning dust models. Considering a classical model of the large
scale Galactic magnetic field, we show that the polarization data of WMAP are
in favor of a soft synchrotron intensity highly correlated with the 408 MHz
data. Furthermore the combination of the WMAP polarization and intensity data
brings strong evidence for the presence of unpolarized spinning dust emission
in the 20-60 GHz range.Comment: accepted by A and
Planck Intermediate Results. IX. Detection of the Galactic haze with Planck
Using precise full-sky observations from Planck, and applying several methods
of component separation, we identify and characterize the emission from the
Galactic "haze" at microwave wavelengths. The haze is a distinct component of
diffuse Galactic emission, roughly centered on the Galactic centre, and extends
to |b| ~35 deg in Galactic latitude and |l| ~15 deg in longitude. By combining
the Planck data with observations from the WMAP we are able to determine the
spectrum of this emission to high accuracy, unhindered by the large systematic
biases present in previous analyses. The derived spectrum is consistent with
power-law emission with a spectral index of -2.55 +/- 0.05, thus excluding
free-free emission as the source and instead favouring hard-spectrum
synchrotron radiation from an electron population with a spectrum (number
density per energy) dN/dE ~ E^-2.1. At Galactic latitudes |b|<30 deg, the
microwave haze morphology is consistent with that of the Fermi gamma-ray "haze"
or "bubbles," indicating that we have a multi-wavelength view of a distinct
component of our Galaxy. Given both the very hard spectrum and the extended
nature of the emission, it is highly unlikely that the haze electrons result
from supernova shocks in the Galactic disk. Instead, a new mechanism for
cosmic-ray acceleration in the centre of our Galaxy is implied.Comment: 15 pages, 9 figures, submitted to Astronomy and Astrophysic
The Interstellar Environment of our Galaxy
We review the current knowledge and understanding of the interstellar medium
of our galaxy. We first present each of the three basic constituents - ordinary
matter, cosmic rays, and magnetic fields - of the interstellar medium, laying
emphasis on their physical and chemical properties inferred from a broad range
of observations. We then position the different interstellar constituents, both
with respect to each other and with respect to stars, within the general
galactic ecosystem.Comment: 39 pages, 12 figures (including 3 figures in 2 parts
PDBe: Protein Data Bank in Europe
The Protein Data Bank in Europe (PDBe; pdbe.org) is a partner in the Worldwide PDB organization (wwPDB; wwpdb.org) and as such actively involved in managing the single global archive of biomacromolecular structure data, the PDB. In addition, PDBe develops tools, services and resources to make structure-related data more accessible to the biomedical community. Here we describe recently developed, extended or improved services, including an animated structure-presentation widget (PDBportfolio), a widget to graphically display the coverage of any UniProt sequence in the PDB (UniPDB), chemistry- and taxonomy-based PDB-archive browsers (PDBeXplore), and a tool for interactive visualization of NMR structures, corresponding experimental data as well as validation and analysis results (Vivaldi)
Changing Behavior : A Theory- and Evidence-Based Approach
Social problems in many domains, including health, education, social relationships, and the workplace, have their origins in human behavior. The documented links between behavior and social problems have sparked interest in governments and organizations to develop effective interventions to promote behavior change. The Handbook of Behavior Change provides comprehensive coverage of contemporary theory, research, and practice on behavior change. The handbook incorporates theory- and evidence-based approaches to behavior change with chapters from leading theorists, researchers, and practitioners from multiple disciplines, including psychology, sociology, behavioral science, economics, and implementation science. Chapters are organized into three parts: (1) Theory and Behavior Change; (2) Methods and Processes of Behavior Change: Intervention Development, Application, and Translation; and (3) Behavior Change Interventions: Practical Guides to Behavior Change. This chapter provides an overview of the theory- and evidence-based approaches of the handbook, introduces the content of the handbook, and provides suggestions on how the handbook may be used by different readers. The handbook aims to provide all interested in behavior change, including researchers and students, practitioners, and policy makers, with up-to-date knowledge on behavior change and guidance on how to develop effective interventions to change behavior in different populations and contexts.Peer reviewe
Planck early results XXI : Properties of the interstellar medium in the Galactic plane
Peer reviewe
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