Search results for "FREQUENCE"
showing 5 items of 5 documents
Oxygen and substrate deprivation on isolated rat cardiac myocytes : temporal relationship between electromechanical and biochemical consequences
1990
The effects of hypoxia and reoxygenation on action potentials (AP), contractions, and certain biochemical parameters were studied in isolated rat ventricular myocytes in monolayer culture in the presence and absence of glucose. Substrate deprivation alone had no influence on the basal properties. In the presence of glucose, a 4-h hypoxic treatment caused only a moderate decrease in AP amplitude and rate. In substrate-free conditions, hypoxia induced a gradual decline in plateau potential level and in AP duration and rate, followed by rhythm abnormalities and a failure of the electromechanical coupling. Spontaneous AP generation then ceased, and the resting potential decreased with increase…
Variations spatiales et temporelles des communautés adventices des cultures annuelles en France
2007
Although arable weed species are particularly well adapted to habitats characterised by high levels of disturbance(ploughing, harvest), the degree and rate at which agro-ecosytems have been transformed in the last 50 years in Europe(use of chemicals, changes in crop rotations) has led to profound changes in the composition and diversity of arable weedcommunities. This thesis provides an update on the composition and diversity of weed communities that can be foundacross the main crop types and regions of France. It also addresses two objectives i) applying (community) ecologytheories for the analysis and interpretation of spatial and temporal variations in weed communities and ii) using the …
Variations spatiales et temporelles de communautés adventices des cultures annuelles en France
2010
Résumé de thèse; National audience
Réseau Biovigilance flore en grandes culture
2007
National audience
Koherentu procesu lāzeru spektroskopijas pētījumi sārmu metālu atomos un molekulās
2014
Promocijas darbs veltīts Zēmana koherenču atomu un molekulu elektroniskajos pamatstāvokļos veidošanas un sabrukšanas teorētiskajai un eksperimentālajai izpētei ar nelineārās spektroskopijas metodēm. Pirmkārt, tiek ziņots polarizācijas modulācijas pētījums, ierosinot D1 pārejas ar Cs tvaikiem pildītā šūnā. Otrkārt, izstrādāta spektroskopijas metode magnētiskā lauka stipruma divdimensiju sadalījuma kartēšanai, izmantojot fluorescences sadalījuma reģistrēšanu. Treškārt, veikts nelineāro magneto-optisko rezonanšu pētījums K2 molekulas pamatstāvoklī ar lielām leņķiskā momenta kvantu skaitļa J~100 vērtībām. Lai uzlabotu diožu lāzera ilgtermiņa frekvences stabilitāti, izstrādāta frekvences divmodu…