132,266 research outputs found
In conversation: Bannert, Molenaar, & Winne - Multiple perspectives on researching and supporting self-regulated learning via analytics
No full textItem does not contain fulltextUnderstanding processes in self-regulated learning (SRL) and tailoring appropriate instructional support to help students become more productive self-regulated learners has been on the agenda of SRL researchers for decades. New data modalities and analytic methods are becoming increasingly available to augment existing methodologies, enhance SRL measurement, test theoretical assumptions about SRL and inform future instructional support. Though promising, this research direction is yet to be fully explored. To learn more about how multimodal learner data and analytic methods can be used to improve research and support for SRL, we invited for a conversation Professors Maria Bannert, Inge Molenaar, and Phil Winne, three prominent scholars who have been extensively researching SRL over the past few decades. The conversation included two parts (1) Studying SRL via Analytics and (2) Supporting SRL via Analytics. The discussion identified several major areas for future research, including integrating multiple data channels in a meaningful way to improve theoretical understanding of SRL, and supporting learners by offering them options on what to do next, rather than by saying that they missed an opportunity to engage in a particular SRL process. Following the polyphonic research methodology, the lead authors and the interviewed SRL scholars co-authored this chapter. A podcast of the conversation is available at https://spotifyanchor-web.app.link/e/NwvHdDh3MMb
Darwin s invisible hand
Full text linkTeusink, B. [Promotor]Molenaar, D. [Copromotor]Bruggeman, F.J. [Copromotor
(-)-CGP12177 increases contractile force through beta1l-adrenoceptors but not through beta3-adrenoceptors in human right atrial myocardium
No full text(-)-CGP12177 is a non-conventional partial agonist that causes modest and transient increases of contractile force in human atrial trabeculae (Kaumann and Molenaar, 2008). These effects are markedly increased and maintained by inhibition of phosphodiesterase PDE3. As verified with recombinant receptors, the cardiostimulant effect of (-)-CGP12177 is mediated through a site at the beta1-adrenoceptor with lower affinity (beta1LAR) compared to the site through which (-)-CGP12177 antagonizes the effects of catecholamines (beta1HAR). However, in a recent report it was proposed that the positive inotropic effects of CGP12177 are mediated through beta3-adrenoceptors (Skeberdis et al 2008). We therefore investigated whether the effects of (-)-CGP12177 on human atrial trabeculae are antagonized by the beta3-adrenoceptor-selective antagonist L-748,337 (1 microM). (-)-CGP12177 (200 nM) caused a stable increase in force which was significantly reduced by the addition of (-)-bupranolol (1 microM), P = 0.002, (basal 4.45 ± 0.78 mN, IBMX (PDE inhibitor) 5.47 ± 1.01 mN, (-)-CGP12177 9.34 ± 1.33 mN, (-)-bupranolol 5.79 ± 1.08 mN, n = 6) but not affected by the addition of L-748,337 (1 microM), P = 0.12, (basal 4.48 ± 1.32 mN, IBMX 7.15 ± 2.28 mN, (-)-CGP12177 12.51 ± 3.71 mN, L-748,337 10.90 ± 3.49 mN, n = 6). Cumulative concentration-effect curves for (-)-CGP12177 were not shifted to the right by L-748,337 (1 microM). The –logEC50M values of (-)-CGP12177 in the absence and presence of L-748,337 were 7.21±0.09 and 7.41±0.13, respectively (data from 25 trabeculae from 8 patients, P=0.2) The positive inotropic effects of (-)-CGP12177 (IBMX present) were not antagonized by L-748,337 but were blunted by (-)-bupranolol (1 microM). The results rule out an involvement of beta3-adrenoceptors in the positive inotropic effects (-)-CGP12177 in human right atrial myocardium and are consistent with mediation through beta1LAR.\ud
\ud
Kaumann A and Molenaar P (2008) Pharmacol Ther 118, 303-336\ud
Skeberdis VA et al (2008) J Clin Invest, 118, 3219-3227\ud
\ud
\u
Perinatal development and nutrient utilization in chickens : effects of incubation conditions
No full textSuboptimal incubation conditions can negatively affect survival and development of chicken embryos. However, physiological mechanisms that may explain these effects, and the long-lasting consequences are largely unknown. Therefore, the first aim of this thesis was to investigate effects of eggshell temperature (EST) and O2 availability during incubation on survival, development, physiology, and nutrient utilization of chicken embryos. The second aim was to investigate long-lasting effects of suboptimal EST on survival and subsequent performance of broiler chickens. The first study investigated effects of a high (38.9°C) or a normal (37.8°C) EST combined with a low (17%), normal (21%), or high (25%) O2 concentration from day 7 until 19 of incubation on the survival rate, nutrient utilization, and the developmental and physiological status of broiler embryos. The second study investigated effects of high EST on glucose metabolism in broiler embryos using [U-13C]glucose. The third study investigated effects of high EST on growth performance and the incidence of ascites in broiler chickens. Finally, effects of a high EST and a hole in the air cell on the developmental and physiological status of layer hatchlings were investigated. Results showed that a high EST or low O2 availability from the first week of incubation onward negatively affected survival and development of broiler chickens from their perinatal period until slaughter age. Body development of broiler hatchlings was reduced after high EST incubation because of a lower efficiency in protein utilization for growth. This was possibly due to the use of glucogenic amino acids as a glucogenic energy source, because high EST increased the glucose oxidation in broiler embryos during the second half of incubation and resulted in lower hepatic glycogen. Body development was proportional to the O2 availability during incubation. In addition, differences in O2 concentration during incubation seem to affect the development of adaptive mechanisms, and these mechanisms might possible influence nutrient utilization and body development. High EST in the last week of incubation in layer embryos negatively affected hatchling development, but the effect of a hole in the air cell was minimal. Effects of high EST were long-lasting in broiler chickens expressed by a lower body weight and a higher ascites incidence during the growout period. In conclusion, negative effects of suboptimal incubation conditions can be partly explained by changes in nutrient utilization and metabolite levels in the perinatal period and can have long-lasting effects on the survival and performance of broiler chickens. <br/
MeSH term explosion and author rank improve expert recommendations
Full text linkInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Testing distributional assumptions in psychometric measurement models with substantive applications in psychology
Full text linkBij psychologisch onderzoek worden tests en vragenlijsten afgenomen waarmee psychologische constructen (persoonseigenschappen die niet direct zichtbaar zijn) zoals intelligentie en extraversie kunnen worden gemeten. Deze metingen zijn nooit helemaal zuiver, doordat bij het antwoorden talloze andere persoonlijke factoren een rol spelen (bijvoorbeeld gemoedstoestand of koffieconsumptie). Deze ‘ruisfactoren’ zorgen voor meetfouten bij het meten van psychologische constructen. Dylan Molenaar onderzocht of bij mensen die verschillen op een psychologisch construct, eenzelfde hoeveelheid meetfouten wordt gemaakt bij het afnemen van de test. Hij bestudeerde hiertoe verschillende constructen, waaronder de persoonlijkheidstrek alexithymie (het onvermogen om emoties onder woorden te brengen). Uit zijn resultaten blijkt dat bij mensen die laag-alexithym zijn een grotere meetfout wordt gemaakt dan bij mensen die hoog-alexithym zijn. Dit heeft als consequentie dat de alexithymiescores een hogere betrouwbaarheid hebben naarmate een respondent hoger scoort op de vragenlijst
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Testing distributional assumptions in psychometric measurement models with substantive applications in psychology
Full text linkBij psychologisch onderzoek worden tests en vragenlijsten afgenomen waarmee psychologische constructen (persoonseigenschappen die niet direct zichtbaar zijn) zoals intelligentie en extraversie kunnen worden gemeten. Deze metingen zijn nooit helemaal zuiver, doordat bij het antwoorden talloze andere persoonlijke factoren een rol spelen (bijvoorbeeld gemoedstoestand of koffieconsumptie). Deze ‘ruisfactoren’ zorgen voor meetfouten bij het meten van psychologische constructen. Dylan Molenaar onderzocht of bij mensen die verschillen op een psychologisch construct, eenzelfde hoeveelheid meetfouten wordt gemaakt bij het afnemen van de test. Hij bestudeerde hiertoe verschillende constructen, waaronder de persoonlijkheidstrek alexithymie (het onvermogen om emoties onder woorden te brengen). Uit zijn resultaten blijkt dat bij mensen die laag-alexithym zijn een grotere meetfout wordt gemaakt dan bij mensen die hoog-alexithym zijn. Dit heeft als consequentie dat de alexithymiescores een hogere betrouwbaarheid hebben naarmate een respondent hoger scoort op de vragenlijst
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
Full text linkBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
- …
