1,672 research outputs found
Atrial Natriuretic Peptide, a Regulator of Nuclear Factor-ÎşB Activation in Vivo
Natriuretic peptides (NPs) comprise a family of vasoactive hormones that play important roles in the regulation of cardiovascular and renal homeostasis. Along this line, atrial NP (ANP) (international non-proprietary name: carperitide, HANP) is an approved drug for the treatment of acute heart failure. In recent years, evidence has been given that the NP system possesses a far broader biological spectrum than the regulation of blood pressure and volume homeostasis. In fact, a substantial amount of in vitro work indicates that ANP affects important inflammatory processes and signaling pathways. Quite surprisingly, however, no information exists on the in vivo antiinflammatory potential and signaling of ANP. We show here that pretreatment of lipopolysaccharide (Salmonella abortus equi, 2.5 mg/kg)-challenged mice with ANP (5μg/kg iv, 15 min) rapidly inhibits nuclear factor-κB activation via inhibition of phosphorylation and degradation of the IκB-α protein. ANP also reduces Akt activation upon lipopolysaccharide injection. In ANP-pretreated mice, the increase of TNF-α serum concentration is markedly prevented; most importantly, the survival of these animals improved. These findings demonstrate both in vitro and in vivo an antiinflammatory profile of ANP that deserves to be further investigated in a therapeutic perspective
Consolidation methods of Romanian historical building with composite materials
Timisoara is a growing city in the western part of Romania, in a seismic area, with a lot
of masonry buildings with historical and cultural value, with interesting structural elements such as
vaults, arches, slabs, walls, that were affected by earthquakes, subsidence of foundations, negative
human actions or lack of interventions. Masonry historical structures in Banat seismic area present
particular failure mechanisms, so there is a need for new, modern, fast, easy-to-apply and reversible
consolidation methods. With this type of methods is possible to assure the local and global
resistance, ductility, stability and rigidity for historical buildings. This article shows the
consolidation methods that were applied on the buildings Sf. Gheorghe 3 and 4, in the historical
centre of Timisoara, on masonry structures with historical value. The solutions that were applied are
using new, innovative fibre-reinforced composite materials, in order to repair the existing damages
and prevent further ones. The consolidation solutions with these new composite materials reduce
the buildings vulnerability and present the advantage of being fast and easy to be executed
Probing the longitudinal momentum spread of the electron wave packet at the tunnel exit
We present an ellipticity resolved study of momentum distributions arising
from strong-field ionization of Helium at constant intensity. The influence of
the ion potential on the departing electron is considered within a
semi-classical model consisting of an initial tunneling step and subsequent
classical propagation. We find that the momentum distribution can be explained
by the presence of a longitudinal momentum spread of the electron at the exit
from the tunnel. Our combined experimental and theoretical study provides an
estimate of this momentum spread
Tunneling Time in Ultrafast Science is Real and Probabilistic
We compare the main competing theories of tunneling time against experimental
measurements using the attoclock in strong laser field ionization of helium
atoms. Refined attoclock measurements reveal a real and not instantaneous
tunneling delay time over a large intensity regime, using two different
experimental apparatus. Only two of the theoretical predictions are compatible
within our experimental error: the Larmor time, and the probability
distribution of tunneling times constructed using a Feynman Path Integral (FPI)
formulation. The latter better matches the observed qualitative change in
tunneling time over a wide intensity range, and predicts a broad tunneling time
distribution with a long tail. The implication of such a probability
distribution of tunneling times, as opposed to a distinct tunneling time,
challenges how valence electron dynamics are currently reconstructed in
attosecond science. It means that one must account for a significant
uncertainty as to when the hole dynamics begin to evolve.Comment: 11 pages, 4 figure
The effect and dynamics of weed competition on maize in Germany and Benin
Four field experiments were carried out in maize at one location in Southern Germany (2009 and 2010) and at two locations in West Atacora, Benin (2010), to determine and compare the effect and dynamics of weed competition under two different environments. Further aims were to determine the critical period for weed control in Benin to provide recommendations to farmers on weed control strategies. Weeds were removed at different crop growth stages of the crop: Emergence, 4-, 8-, 10-leaf stage and flowering and maize plots were kept weed-free until harvest. In Benin, weeds were additionally removed until the aforementioned growth stages and then allowed to reemerge until harvest. Crop growth parameters and weed biomass were monitored over the whole growing season. Dry grain yield was recorded at harvest. Logistic and Gompertz equations were used to determine the critical period for weed control. The four main weeds in Germany were the dicotyledonous species Chenopodium album, Galium aparine, Stellaria media and Capsella bursa-pastoris. In Benin, the two grasses Setaria pumila and Bulbostylis hispidula and the two dicotyledonous weeds Stachytarpheta indica and Mitracarpus villosus prevailed. For all sites, the main weeds were primarily annual species. In Germany, grain yield levels without weed competition ranged from 8.5 to 10.3 t/ha; in Benin the average yield was considerably lower (3.4 t/ha). As expected, yield loss increased significantly with duration of weed competition and yield losses were highest in the control amounting to 49–86 % (Germany) and 38–58 % (Benin). For Benin, the results confirmed that weeds have to be controlled from about the 4-leaf stage until almost flowering to reduce yield loss below 20 %. As weed control is mainly done by hand, this is difficult to achieve due to the shortage of family labor and the high costs of hired labor. Keywords: Critical period for weed control, crop-weed interaction, Gompertz curve, logistic curve, non-linear regression, yield lossWirkung und Dynamik der Unkrautkonkurrenz auf Mais in Deutschland und BeninVier Feldversuche wurden an einem Standort in Süddeutschland (2009-2010) und an zwei Standorten in West Atacora, Benin (2010), durchgeführt, um den Effekt und die Dynamik der Unkrautkonkurrenz auf die Kulturpflanze Mais in zwei verschiedenen Umgebungen zu bestimmen und zu vergleichen. Weitere Ziele waren die Bestimmung des kritischen Zeitintervalls für die Unkrautbekämpfung in Mais im Benin um die Beratung der Landwirte im Benin zu verbessern. Die Unkräuter wurden von einem bestimmten Wachstumsstadium der Kulturpflanze an entfernt: Auflauf, 4-, 8-, 10-Blattstadium und Blüte und die Parzellen wurden dann bis zur Ernte unkrautfrei gehalten. Im Benin wurden zusätzlich die Unkräuter bis zu den entsprechenden Wachstumsstadien entfernt, danach wurden auflaufende Unkräuter bis zur Ernte nicht mehr entfernt. Wachstumsparameter der Kulturpflanzen und die Unkrautbiomasse wurden während der Vegetationszeit beobachtet. Der Kornertrag wurde bei der Ernte bestimmt. Logistische und Gompertz-Gleichungen wurden zur Bestimmung der zeitbezogenen Schadensschwelle verwendet. In Deutschland waren die vier dikotylen Leitunkräuter Chenopodium album, Galium aparine, Stellaria media und Capsella bursa-pastoris. Dagegen dominierten im Benin die zwei Ungräser Setaria pumila und Bulbostylis hispidula sowie die zweikeimblättrigen Unkräuter Stachytarpheta indica und Mitracarpus villosus. In allen Versuchen dominierten einjährige Unkräuter. In Deutschland lagen die Erträge ohne Unkrautkonkurrenz zwischen 8.5 t/ha (2010) und 10.3 t/ha (2009), im Benin lag der durchschnittliche Ertrag deutlich tiefer (3.4 t/ha). Wie erwartet, stieg der Ertragsverlust mit zunehmender Dauer der Unkrautkonkurrenz an. Er war in der Kontrolle am höchsten und lag zwischen 49-86 % in Deutschland und 38-58 % im Benin. Für Benin zeigen die Ergebnisse, dass Unkräuter etwa vom 4-Blatt-Stadium bis beinahe zur Blüte bekämpft werden müssen, um den Ertragsverlust unter 20 % zu halten. Da die Unkrautbekämpfung vor allem von Hand erfolgt, ist dies schwierig zu erreichen, da die Arbeitszeit der Familien begrenzt und die Lohnkosten für Arbeiter relativ hoch sind. Stichwörter: Ertragsverlust, Gompertz-Gleichung, logistische Gleichung, nicht lineare Regression, Unkraut-Kulturpflanzen-Interaktion, zeitbezogene Schadensschwell
Egyházi óvodák: munkakörülmények és szakmai autonómia óvónői szemmel
Tanulmányunk az egyházi fenntartĂłk számának növekedĂ©sĂ©t vizsgálja az Ăłvodaiszektorban. Azt kĂvánjuk feltĂ©rkĂ©pezni, hogy az iskolákhoz kĂ©pestdecentralizáltan működĹ‘ Ăłvodák esetĂ©ben milyen hasonlĂłságok Ă©s kĂĽlönbsĂ©gekfigyelhetĹ‘k meg az egyházi fenntartĂłk növekvĹ‘ jelenlĂ©te kapcsán. A cikkbenbemutatjuk az egyházi fenntartás növekedĂ©sĂ©nek mĂ©rtĂ©kĂ©t, az átvĂ©tel mĂłdjait Ă©saz egyházi fenntartĂłra vonatkozĂł szabályozási környezetet. Továbbá egy feltárĂłempirikus kutatás eredmĂ©nyeire alapozva vizsgáljuk, hogy az egyházi fenntartĂłkmegjelenĂ©se milyen lehetĹ‘sĂ©geket Ă©s korlátokat jelent a mindennapi szakmai munkaterĂ©n az ĂłvodapedagĂłgusok számára a munkavĂ©gzĂ©s körĂĽlmĂ©nyei, a szakemberiellátottság, valamint gyermekek felvĂ©tele Ă©s a pedagĂłgiai programtekintetĂ©ben
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