358 research outputs found
Nostalgia
No full textThis study examines the relationship between nostalgia and well-being across the lifespan. This questionnaire made use of the Dutch translation of the Southampton Nostalgia Scale, the Batcho Nostalgia Inventory, the Belongingness Orientations Scale and part of the Ryff Wellbeing Inventory.</span
Na-ca Exchange And Ca Fluxes During Contraction And Relaxation In Mammalian Ventricular Muscle
No full textThere are four cellular Ca transport systems which compete to remove Ca from the myoplasm in mammalian ventricular myocytes. These are 1) the SR Ca-ATPase, 2) the sarcolemmal Na-Ca exchange, 3) the sarcolemmal Ca-ATPase and 4) the mitochondrial Ca uniporter. Using multiple experimental approaches we have evaluated the dynamic interaction of these systems during the normal cardiac contraction-relaxation cycle. The SR Ca-ATPase and Na-Ca exchange are clearly the most important, quantitatively; however, the relative roles vary in a species-dependent manner. In particular, the SR is much more strongly dominant in rat ventricular myocytes, where ~ 92% of Ca removal is via SR Ca-ATPase and only 7% via Na-Ca exchange during a twitch. In other species (rabbit, ferret, cat, and guinea pig) the balance is more in the range of 70% SR Ca-ATPase and 25-30% Na-Ca exchange. Ferret ventricular myocytes also exhibit an unusually strong sarcolemmal Ca-ATPase. During the steady state the same amount of Ca must leave the cell as enters over a cardiac cycle. This implies that 25-30% of the Ca required to activate contraction must enter the cell, and experiments demonstrate that this amount of Ca may be supplied by the L-type Ca current.779430442Bers, D.M., (1991) Excitation-Contraction Coupling and Cardiac Contractile Force, pp. 1-258. , (Single author monograph.) Kluwer Academic Press. Dordrecht, NetherlandsSutko, J.L., Willerson, J.T., Ryanodine alteration of the contractile state of rat ventricular myocardium. Comparison with dog, cat and rabbit ventricular tissues (1980) Circ. Res., 46, pp. 332-343Bers, D.M., Ca influx and SR Ca release in cardiac muscle activation during postrest recovery (1985) Am. J. Physiol., 248, pp. H366-H381Bers, D.M., Mechanisms contributing to the cardiac inotropic effect of Na-pump inhibition and reduction of extracellular Na (1987) J. Gen. Physiol., 90, pp. 479-504Bers, D.M., Christensen, D.M., Nguyen, T.X., Can Ca entry via Na-Ca exchange directly activate cardiac muscle contraction? (1988) J. Mol. Cell. Cardiol., 20, pp. 405-414Beuckelmann, D.J., Wier, W.G., Mechanism of release of calcium from sarcoplasmic reticulum of guinea pig cardiac cells (1988) J. Physiol., 405, pp. 233-255Fabiato, A., Time and calcium dependence of activation and inactivation of calcium-induced release of calcium from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell (1985) J. Gen. Physiol., 85, pp. 247-290Leblanc, N., Hume, J.R., Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum (1990) Science, 248, pp. 372-376Levi, A.J., Spitzer, K.W., Kohmoto, O., Bridge, J.H.B., Depolarization-induced Ca entry via Na-Ca exchange triggers SR release in guinea pig cardiac myocytes (1994) Am. J. Physiol., 266, pp. H1422-H1433Kohmoto, O., Levi, A.J., Bridge, J.H.B., Relation between reverse sodium-calcium exchange and sarcoplasmic reticulum calcium release in guinea pig ventricular cells (1994) Circ. Res., 74, pp. 550-554Bassani, R.A., Bassani, J.W.M., Bers, D.M., Mitochondrial and sarcolemmal Ca transport can reduce [Ca]i during caffeine contractures in rabbit cardiac myocytes (1992) J. Physiol., 453, pp. 591-608Bassani, J.W.M., Bassani, R.A., Bers, D.M., Relaxation in rabbit and rat cardiac cells: Species-dependent differences in cellular mechanisms (1994) J. Physiol., 476, pp. 279-293Bassani, R.A., Bassani, J.W.M., Bers, D.M., Relaxation in ferret ventricular myocytes: Unusual interplay among calcium transport systems (1994) J. Physiol., 476, pp. 295-308Bers, D.M., Bridge, J.H.B., Relaxation of rabbit ventricular muscle by Na-Ca exchange and sarcoplasmic reticulum Ca-pump: Ryanodine and voltage sensitivity (1989) Circ. Res., 65, pp. 334-342Bridge, J.H.B., Relationships between the sarcoplasmic reticulum and transarcolemmal Ca transport revealed by rapidly cooling rabbit ventricular muscle (1986) J. Gen. Physiol., 88, pp. 437-473Bers, D.M., Bridge, J.H.B., Spitzer, K.W., Intracellular Ca transients during rapid cooling contractures in guinea-pig ventricular myocytes (1989) J. Physiol., 417, pp. 537-553Bers, D.M., Lederer, W.J., Berlin, J.R., Intracellular Ca transients in rat cardiac myocytes: Role of Na/Ca exchange in excitation-contraction coupling (1990) Am. J. Physiol., 258, pp. C944-C954Hryshko, L.V., Stiffel, V.M., Bers, D.M., Rapid cooling contractures as an index of SR Ca content in rabbit ventricular myocyte (1989) Am. J. Physiol., 257, pp. H1369-H1377Hove-Madsen, L., Bers, D.M., SR Ca uptake and thapsigargin sensitivity in permeabilized rabbit and rat ventricular myocytes (1993) Cir. Res., 73, pp. 820-828Bassani, J.W.M., Bassani, R.A., Bers, D.M., Twitch-dependent SR Ca accumulation and release in rabbit ventricular myocytes (1993) Am. J. Physiol., 265, pp. C533-C540Bassani, R.A., Bers, D.M., Rate of diastolic Ca release from the sarcoplasmic reticulum of intact rabbit and rat ventricular myocytes (1995) Biophys. J., 68, pp. 2015-2022Bassani, J.W.M., Yuan, W., Bers, D.M., Fractional SR Ca release is altered by trigger Ca and SR Ca content in cardiac myocytes (1995) Am. J. Physiol., 268, pp. 1313-1319Gatto, C., Milanick, M.A., Inhibition of the red blood cell calcium pump by eosin and other fluorescein analogues (1993) Am. J. Physiol., 264, pp. C1577-C1586Gatto, C., Hale, C.C., Milanick, M.A., Eosin, a potent inhibitor of the plasma membrane Ca pump, does not inhibit the cardiac Na-Ca exchanger (1995) Biochemistry, 34, pp. 965-972Bassani, R.A., Bassani, J.W.M., Bers, D.M., Relaxation in ferret ventricular myocytes: Role of the sarcolemmal Ca ATPase (1995) Pflüg. Arch., 430, pp. 573-579Hove-Madsen, L., Bers, D.M., Passive Ca buffering and SR Ca uptake in permeabilized rabbit ventricular myocytes (1993) Am. J. Physiol., 264, pp. C677-C686Negretti, N., O'Neill, S.C., Eisner, D.A., The relative contributions of different intracellular and sarcolemmal systems to relaxation in rat ventricular myocytes (1993) Cardiovasc. Res., 27, pp. 1826-1830Crespo, L.M., Grantham, C.J., Cannell, M.B., Kinetics, stoichiometry and role of the Na-Ca exchange mechanism in isolated cardiac myocytes (1990) Nature, 345, pp. 618-621Puglisi, J.L., Bassani, R.A., Bassani, J.W.M., Amin, J.N., Bers, D.M., Temperature and the relative contributions of Ca transport systems in cardiac myocyte relaxation (1996) Am. J. Physiol., , In pressDelbridge, L.M., Bassani, J.W.M., Bers, D.M., Steady-state twitch Ca fluxes and cytosolic Ca buffering in rabbit ventricular myocytes (1996) Am. J. Physiol., 39, pp. C192-C199Fabiato, A., Calcium-induced release of calcium from the cardiac sarcoplasmic reticulum (1983) Am. J. Physiol., 245, pp. C1-C1
Innovation in online data collection for scientific research: The Dutch MESS project
Full text linkNot many long-running scientific studies in Europe or the United States use online panels. Leading scientific studies mostly use face-to-face or telephone interviews to collect data. However, Internet interviewing is cost-effective and offers various new possibilities for empirical research in the social sciences. In principle, one can measure new or complex concepts in much shorter time frames than is customary in more traditional survey research. Furthermore, the technology allows for, for example, experimentation, follow-up data collection, and respondents’ feedback. Based on earlier experiences with an online scientific panel, an advanced data collection environment for the social sciences was proposed in the Netherlands: ‘An Advanced Multi-Disciplinary Facility for Measurement and Experimentation in the Social Sciences’ (MESS). The facility creates maximal opportunities for innovation, is fast, and freely accessible for everyone in the scientific community. The core of this facility is a representative panel of households that have agreed to be available for regular interviews over the Internet: the LISS (Longitudinal Internet Studies for the Social sciences) panel. In addition to traditional questionnaire settings, the facility accommodates use of visual displays, preloading of data, and self-administered measurement of biomarkers. The project aims at integrating various fields of study, such as economics, social sciences, (bio)medical science and behavioral science. Funding for the project was secured in 2006. This paper describes the needs to which the MESS project was responding and the process of setting up the facility. Attention will also be paid to the cost and sustainability of a facility like MESS, and to wider developments (beyond the borders of the Netherlands)
On income expectations and other subjective data: A micro-econometric analysis
Full text linkThis thesis focuses on subjective data, in particular, answers to questions on income growth expectations. The emphasis is on the reliability and usefulness of subjective information. The data are from the Socio-Economic Panel (SEP), which is administered by Statistics Netherlands (CBS) and the VSB panel, which has been devised by researchers at CentER for Economic Research at Tilburg University. Using the panel nature of the SEP, expectations about income growth were compared with corresponding realizations. In addition to the empirical analyses of income growth expectations and uncertainty about future income, attention was paid to some methodological aspects of ordered categorical data
Innovation der Online-Datenerhebung für wissenschaftliche Forschungen. Das niederländische MESS-Projekt
No full textNicht viele wissenschaftliche Langzeitstudien in Europa oder in den Vereinigten Staaten stützen sich auf Online-Panels. In führenden wissenschaftlichen Studien wird zur Datenerhebung meist auf Face-to-Face-Interviews oder Telefoninterview zurückgegriffen. Im Vergleich dazu ist die Internetbefragung kosteneffizienter und bietet der empirischen Forschung in den Sozialwissenschaften verschiedene neue Möglichkeiten. Grundsätzlich können neue oder komplexe Konzepte innerhalb viel kürzerer Zeitrahmen bewertet werden, als dies in der herkömmlichen Meinungsforschung üblich ist. Außerdem sind technologiebedingt z.B
Extensions of the Ordered Response Model Applied to Consumer Valuation of New Products
Full text linkIn an ordered response model the observed variable is based upon classifying an unobserved variable into one out of a finite number of intervals forming a dissection of the real line (cf. Amemiya, 1981). This model considers the boundaries of the intervals as (unknown) deterministic parameters, the same for every individual. Terza (1985) extended this through the relaxation of the assumed constancy of the boundaries: he allowed the boundaries to be a linear function of observed explanatory variables. We extend the deterministic model by allowing for random boundaries that vary across individuals. A case study on consumer valuation of new products indicates that random boundaries significantly improve the standard ordered response model
How representative are online panels?:Problems of coverage and selection and possible solutions
No full textHow Certain are Dutch Households about Future Income? An Empirical Analysis
Full text linkThe growing literature on precautionary saving clearly indicates the need for measurement of income uncertainty. In this paper we empirically analyze subjective income uncertainty in the Netherlands. Data come from the Dutch VSB panel. We measure income uncertainty directly by asking questions on expected household income in the next twelve months. First, we describe our data and compare a measure of income uncertainty with corresponding studies conducted in the US and Italy. Second, we investigate the relationship between the measure of income uncertainty and some household characteristics. Controlling for information on expected changes, we find strong relationships between labor-market characteristics and the subjective income uncertainty as reported by the heads of households.subjective information;income expectations;income uncertainty
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