Search results for "time lag"
showing 10 items of 14 documents
Direct terrestrial–marine correlation demonstrates surprisingly late onset of the last interglacial in central Europe
2011
AbstractAn interdisciplinary study of a small sedimentary basin at Neumark Nord 2 (NN2), Germany, has yielded a high-resolution record of the palaeomagnetic Blake Event, which we are able to place at the early part of the last interglacial pollen sequence documented from the same section. We use this data to calculate the duration of this stratigraphically important event at 3400 ± 350 yr. More importantly, the Neumark Nord 2 data enables precise terrestrial–marine correlation for the Eemian stage in central Europe. This shows a remarkably large time lag of ca. 5000 yr between the MIS 5e ‘peak’ in the marine record and the start of the last interglacial in this region.
Multisite field potential recordings and analysis of the impulse propagation pattern in cardiac cells culture
2007
To provide further insights into the impulse propagation between cardiac myocytes, we performed multiparametric studies of excitation spread with cellular resolution in confluent monolayers of cultured cardiomyocytes (CM). Simultaneous paired intracellular recordings of action potentials in two individual CM revealed slight periodic spontaneous advances/delays in the interspike time lag. Multisite field potential recordings performed with microelectrode arrays (MEA) confirmed random and iterative cycle-to-cycle changes in the direction of excitation spread. These local spontaneous variations in the cardiac impulse propagation pathways may be a safety process protecting against microscopical…
Estimation of the time lag occurring between vegetation indices and aridity indices in a Sicilian semi-arid catchment
2009
The evolution of drought phenomena in a Sicilian semi-arid catchment has been analyzed processing both remote sensing images and climatic data for the period 1985-2000. The remote sensing dataset includes Landsat TM and ETM+ multispectral images, while the climatic dataset includes monthly rainfall and air temperature. The results have been specifically discussed for areas where it is possible to neglect agricultural activities and vegetation growth is only influenced by natural forcing. The main outcome of this study is the quantification of the time lag between the remote sensing retrieved vegetation indices and the aridity indices (AIs) calculated from climatic data. Moreover the obtaine…
On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model
2018
Actual evapotranspiration is assessed via surface energy balance at an hourly rate. However, a robust estimation of daily evapotranspiration from hourly values is required. Outcomes of surface energy balance are frequently determined via measures of eddy covariance latent heat flux. Surface energy balance can be applied on images acquired at different times and spatial resolutions. In addition, hourly actual evapotranspiration needs to be integrated at a daily rate for operational uses. Questions arise whether the validation of surface energy balance models can benefit from complementary in situ measures of latent heat flux and sap flow transpiration. Here, validation was driven by image ac…
“The Same Staff Can Be Enough”. Employers’ Resilience Strategies in Recruitment Decisions
2018
Studies on resilience have sprung from a need to understand the survival strategies of organizations when faced with the emergence of unexpected, potentially destructive and negative events in the lives of the organizations. This article, on the other hand, intends to highlight organizational resilience when confronted with unexpected positive events, seldom considered by such studies. This is the well-known macroeconomic phenomenon of the time lag between economic growth and labor demand at the moment that a regressive economic cycle is reversed. With which strategies do companies, in the face of such an event, transform a resilient attitude into real resilient behavior? Five strategies of…
Timing in methods for studying psychosocial factors at work
2014
In the present chapter we focus on time lags in panel studies investigating psychosocial factors and stressor-strain relationships. First, a framework of theoretical reasons for choosing specific time lags is provided, which is based on the work by Frese and Zapf (Methodological issues in the study of work stress: objective vs. subjective measurement of work stress and the question of longitudinal studies. In: Cooper CL, Payne R (eds) Causes, coping and consequences of stress at work. Wiley, Chichester, pp 375–411, 1988). Although this theoretical framework provides a clear rationale for time intervals, researchers are frequently mistaken using it to derive appropriate time lags. Second, an…
Gas Transport in Mixed Matrix Membranes: Two Methods for Time Lag Determination
2020
The most widely used method to measure the transport properties of dense polymeric membranes is the time lag method in a constant volume/pressure increase instrument. Although simple and quick, this method provides only relatively superficial, averaged data of the permeability, diffusivity, and solubility of gas or vapor species in the membrane. The present manuscript discusses a more sophisticated computational method to determine the transport properties on the basis of a fit of the entire permeation curve, including the transient period. The traditional tangent method and the fitting procedure were compared for the transport of six light gases (H2, He, O2, N2, CH4, and CO2) and ethane an…
Testing cross-lagged relationships between work-related rumination and well-being at work in a three-wave longitudinal study across 1 and 2 years
2019
The aim of this three-wave longitudinal study conducted among 664 Finnish employees was to examine the cross-lagged relationships between various work-related ruminative thoughts (affective rumination, problem-solving pondering, lack of detachment from work) during off-job time and employee well-being (exhaustion, vigour). We tested normal, reversed, and reciprocal temporal relationships across 1 and 2 years using structural equation modelling. The analyses lent most support to the reversed temporal relationships, showing first that high exhaustion predicted low problem-solving pondering 2 years later and second, that high vigour predicted low affective rumination both 1 and 2 years later. …
Gains and losses related to career transitions within organisations
2014
Abstract With this study we aim to look at potential gains and losses in terms of higher career satisfaction and increased strain levels as a consequence of intraorganisational upward career transitions. Following the idea of a matching principle, we further expected stressors to mediate the relationship between transitions and strain, and resources to mediate the relationship between transitions and career satisfaction. Altogether, N = 581 employees from 11 German organisations filled in an online questionnaire twice, with a time lag of one year. About 20% of the respondents stated having experienced upward transitions. SEM analyses using latent difference scores for the mediators and depe…
Dans l’hépatite chronique C, les délais entre diagnostic et traitement sont liés à la relation médecins-patients
2009
Une etude epidemiologique menee en 2004 en Cote d’Or et dans le Doubs revelait que parmi 1 251 patients porteurs du VHC, un sur 4 etait traite et un sur 6 ne beneficiait d’aucune prise en charge. Une etude qualitative faite en Bourgogne en 2006-2008 visait a identifier les raisons de l’insuffisance de soins ; 25 medecins ont ete interroges sur leur confrontation a l’infection par le VHC et les difficultes de sa prise en charge, et 27 patients atteints d’hepatite chronique C sur les circonstances du depistage et du diagnostic, l’itineraire de soins, la representation et le vecu de la maladie et du traitement, les relations avec les soignants. L’etude a revele une grande variabilite dans les …