430 research outputs found
La cassiicoline, seul facteur de la virulence de Corynespora cassiicola chez l'hévéa ?
Could thioredoxin h be involved in early response to gravitropic stimulation of poplar stems?
The perception of gravity is essential for plant development. Trees constantly develop specialized woody tissues, termed « reaction wood » to correct inclined branch and stem growth in order to adopt an optimal position. Despite the economical impact of reaction wood occurrence and itsimportance from a developmental point of view, the perception and response to the gravitational stimulus have not been extensively studied in woody species in which primary and secondary growth occur. Using complementary approaches (proteomics, qRT-PCR, immunolocalization), we have compared straight polar stems to stems that were inclined at 35° from the vertical axis for periods of time varying from 10 min to 6 hours depending on the experiments. The proteomics approach revealed that thirty six percent of the identified proteins that were differentially expressed after gravistimulation were established as potential Thioredoxin targets. qRT-PCR indicated an early induction of Thioredoxin h expression following gravistimulation. In situ immunolocalization indicated that Thioredoxin h protein co-localized with the amyloplasts located in the endodermalcells which may be specialized in gravity perception. These investigations suggest the involvement of Thioredoxin h in the first events of signal transduction in inclined poplar stems, leading to reaction wood formation
Carbon Isotopes Near Drip Lines in the Relativistic Mean-Field Theory
We have investigated the ground-state properties of carbon isotopes in the
framework of the relativistic mean-field (RMF) theory. RMF calculations have
been performed with the non-linear scalar self-coupling of the meson
using an axially symmetric deformed configuration. We have also introduced the
vector self-coupling of the meson for the deformed mean-field
calculations. The results show that the RMF predictions on radii and
deformations are in good agreement with the available experimental data. It is
shown that several carbon isotopes possess a highly deformed shape akin to a
superdeformation. The single-particle structure of nuclei away from the
stability line has been discussed with a view to understand the properties near
the neutron drip line. Predictions of properties of carbon isotopes away from
the stability line are made.Comment: Revtex, 29 pages, 11 postscript figures include
Light Nuclei near Neutron and Proton Drip Lines in the Relativistic Mean-Field Theory
We have made a detailed study of the ground-state properties of nuclei in the
light mass region with atomic numbers Z=10-22 in the framework of the
relativistic mean-field (RMF) theory. The nonlinear model with
scalar self-interaction has been employed. The RMF calculations have been
performed in an axially deformed configuration using the force NL-SH. We have
considered nuclei about the stability line as well as those close to proton and
neutron drip lines. It is shown that the RMF results provide a good agreement
with the available empirical data. The RMF predictions also show a reasonably
good agreement with those of the mass models. It is observed that nuclei in
this mass region are found to possess strong deformations and exhibit shape
changes all along the isotopic chains. The phenomenon of the shape coexistence
is found to persist near the stability line as well as near the drip lines. It
is shown that the magic number N=28 is quenched strongly, thus enabling the
corresponding nuclei to assume strong deformations. Nuclei near the neutron and
proton drip lines in this region are also shown to be strongly deformed.Comment: 49 pages Latex, 12 postscript figures, to appear in Nuclear Physics
Themenbezogenes Netzwerk: Rinder-, Schweine- und Hühnerzucht im ökologischen Landbau
Das Netzwerk arbeitete in Form von tierartbezogenen Arbeitsgruppen, die ihre Ergebnisse in Workshops diskutieren. Koordiniert wurden die Fachgruppen von ausgewiesenen Experten; die administrative Koordination übernahm die Zukunftsstiftung Landwirtschaft. Es wurden 7 Workshops mit insgesamt 100 Teilnehmern organisiert. Das Netzwerk tauschte Praxiserfahrungen und Forschungsergebnisse zur Tierzucht aus, definierte Zuchtziele und erarbeitete den Handlungsbedarf in der Rinder-, Schweine- und Hühnerzucht für den Ökologischen Landbau.
Bisher werden im Biolandbau bei allen Tierarten weitgehend die gleichen Rassen und Linien und damit die gleiche Genetik gehalten wie in der konventionellen Landwirtschaft. Aus ethischen Gründen und wegen der abweichenden Haltungs- und Fütterungsbedingungen ist langfristig eine Tierzucht für die ökologische Landwirtschaft erforderlich. Da mit extensiven Formen der konventionellen Tierhaltung (Legehennen-Freilandhaltung, Grundfutterbetonte Fütterung von Milchvieh in Grünlandgebieten, Schweinmast auf Stroh) Übereinstimmung bei wesentlichen Zuchtzielen erreicht werden kann, sind entsprechende Kooperationen erforderlich.
Viel versprechende Arbeitsansätze für Praxis und Wissenschaft wurden identifiziert:
- In der Rinderzucht: Zucht auf Lebensleistung, Weiterentwicklung und Ausdehnung des ÖZW, Förderung der einzelbetrieblichen Handlungsebene in der Züchtung.
- In der Hühnerzucht Kooperation mit Zuchtunternehmen zur Anpassung bestimmter Hybridlinien an die Anforderungen des ökologischen Landbaus, Leistungsprüfung für verschiedene Hybrid-Herkünfte, Screening von Rassegeflügel in Feld- und Stationsprüfungen unter Öko-Bedingungen, Entwicklung von Zuchtprogrammen für bäuerliche Rassezucht.
- In der Schweinezucht Prüfung verschiedener Genotypen unter richtlinienkonformen Bedingungen und exemplarische Kooperationen mit regionalen Züchtervereinigungen zur partiellen Anpassung ihrer Zuchtarbeit an die Anforderungen der ökologischen und artgerechten Schweinehaltung.
- Schließlich ist die Bewertung von Züchtungstechniken wie Künstliche Besamung, Embryotransfer, in-vitro-Fertilisation und Marker gestützte Selektion, die in den Richtlinien für Ökologischen Landbau kritisch beurteilt oder ausgeschlossen sind, anhand transparenter Kriterien erforderlich
Interactions of (2S,6S;2R,6R)-Hydroxynorketamine, a Secondary Metabolite of (R,S)-Ketamine, with Morphine
Ketamine and its primary metabolite norketamine attenuate morphine tolerance by antagonising N-methyl-d-aspartate (NMDA) receptors. Ketamine is extensively metabolized to several other metabolites. The major secondary metabolite (2S,6S;2R,6R)-hydroxynorketamine (6-hydroxynorketamine) is not an NMDA antagonist. However, it may modulate nociception through negative allosteric modulation of 7 nicotinic acetylcholine receptors. We studied whether 6-hydroxynorketamine could affect nociception or the effects of morphine in acute or chronic administration settings. Male Sprague Dawley rats received subcutaneous 6-hydroxynorketamine or ketamine alone or in combination with morphine, as a cotreatment during induction of morphine tolerance, and after the development of tolerance induced by subcutaneous minipumps administering 9.6 mg morphine daily. Tail flick, hot plate, paw pressure and rotarod tests were used. Brain and serum drug concentrations were quantified with high-performance liquid chromatography-tandem mass spectrometry. Ketamine (10 mg/kg), but not 6-hydroxynorketamine (10 and 30 mg/kg), enhanced antinociception and decreased rotarod performance following acute administration either alone or combined with morphine. Ketamine efficiently attenuated morphine tolerance. Acutely administered 6-hydroxynorketamine increased the brain concentration of morphine (by 60%), and brain and serum concentrations of 6-hydroxynorketamine were doubled by morphine pre-treatment. This pharmacokinetic interaction did not, however, lead to altered morphine tolerance. Co-administration of 6-hydroxynorketamine 20 mg/kg twice daily did not influence development of morphine tolerance. Even though morphine and 6-hydroxynorketamine brain concentrations were increased after co-administration, the pharmacokinetic interaction had no effect on acute morphine nociception or tolerance. These results indicate that 6-hydroxynorketamine does not have antinociceptive properties or attenuate opioid tolerance in a similar way as ketamine.Peer reviewe
Shell Effects in Nuclei with Vector Self-Coupling of Omega Meson in Relativistic Hartree-Bogoliubov Theory
Shell effects in nuclei about the stability line are investigated within the
framework of the Relativistic Hartree-Bogoliubov (RHB) theory with
self-consistent finite-range pairing. Using 2-neutron separation energies of Ni
and Sn isotopes, the role of - and -meson couplings on the
shell effects in nuclei is examined. It is observed that the existing
successful nuclear forces (Lagrangian parameter sets) based upon the nonlinear
scalar coupling of -meson exhibit shell effects which are stronger than
suggested by the experimental data. We have introduced nonlinear vector
self-coupling of -meson in the RHB theory. It is shown that the
inclusion of the vector self-coupling of -meson in addition to the
nonlinear scalar coupling of -meson provides a good agreement with the
experimental data on shell effects in nuclei about the stability line. A
comparison of the shell effects in the RHB theory is made with the Hartree-Fock
Bogoliubov approach using the Skyrme force SkP. It is shown that the
oft-discussed shell quenching with SkP is not consistent with the available
experimental data.Comment: 34 pages latex, 18 ps figures, replaced with minor corrections in
some figures, accepted for publication in Phys. Rev.
Innovative Nitrogen and Carbon Removal
The aerobic systems have been the most widely biological treatment used for municipal and industrial wastewater but show serious problem with sludge sedimentation, high energy demand and microbial inhibition. On the other hand, the anaerobic digestion (AD) of wastewater is considered the best alternative to remove the organic compounds and to recover energy via methane production. Nevertheless, AD has a problem: the treatment of industrial wastewater with high organic nitrogen content reaches high free ammonia (NH3) concentrations due to the protein degradation. NH3 inhibits the methanogenic process and is toxic to the environment, and then, it must be removed before its final disposition. Several physicochemical processes have been evaluated for the recovery or/and treatment of ammonium from wastewater. The most frequent treatments are gas stripping and magnesium ammonium phosphate precipitation. These methods are effective, but they are very expensive compared to biological treatments. Moreover, these techniques usually require more power consumption than the biological process. The technologies based on partial nitrification and Anammox (PN‐A) are the ones with better performance. Thus, this chapter mainly focuses on biological processes based on AD, denitrification and PN‐A for the removal of carbon and nitrogen from industrial wastewater with recovery of energy and water
CB1 Agonism Alters Addiction-Related Behaviors in Mice Lacking Mu or Delta Opioid Receptors
Opioids are powerful analgesics but the clinical utility of these compounds is reduced by aversive outcomes, including the development of affective and substance use disorders. Opioid systems do not function in isolation so understanding how these interact with other neuropharmacological systems could lead to novel therapeutics that minimize withdrawal, tolerance, and emotional dysregulation. The cannabinoid system is an obvious candidate as anatomical, pharmacological, and behavioral studies point to opioid-cannabinoid interactions in the mediation of these processes. The aim of our study is to uncover the role of specific cannabinoid and opioid receptors in addiction-related behaviors, specifically nociception, withdrawal, anxiety, and depression. To do so, we tested the effects of a selective CB1 agonist, arachidonyl-2-chloroethylamide (ACEA), on mouse behavior in tail immersion, naloxone-precipitated withdrawal, light-dark, and splash tests. We examined cannabinoid-opioid interactions in these tests by comparing responses of wildtype (WT) mice to mutant lines lacking either Mu or Delta opioid receptors. ACEA, both acute or repeated injections, had no effect on nociceptive thresholds in WT or Mu knockout (KO) mice suggesting that analgesic properties of CB1 agonists may be restricted to chronic pain conditions. The opioid antagonist, naloxone, induced similar levels of withdrawal in all three genotypes following ACEA treatment, confirming an opioidergic contribution to cannabinoid withdrawal. Anxiety-like responses in the light-dark test were similar across WT and KO lines; neither acute nor repeated ACEA injections modified this behavior. Similarly, administration of the Delta opioid receptor antagonist, naltrindole, alone or in combination with ACEA, did not alter responses of WT mice in the light-dark test. Thus, there may be a dissociation in the effect of pharmacological blockade vs. genetic deletion of Delta opioid receptors on anxiety-like behavior in mice. Finally, our study revealed a biphasic effect of ACEA on depressive-like behavior in the splash test, with a prodepressive state induced by acute exposure, followed by a shift to an anti-depressive state with repeated injections. The initial pro-depressive effect of ACEA was absent in Mu KO mice. In sum, our findings confirm interactions between opioid and cannabinoid systems in withdrawal and reveal reduced depressive-like symptoms with repeated CB1 receptor activation
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