186,618 research outputs found
P-H. Spaak Activities in the Sphere of European Integration
No full textIn this article the activities of Paul-Henri Spaak, a Belgian politician, are examined. Mr. Spaak is well-known as initiator of postwar European integration. He was one of the originators of the Council of Europe, participated in development of European Coal and Steel Community project, headed the committee, that elaborated Treaties of Rome about European Economic Community and European Atomic Energy Community. Owing to his active work at European association, in 1950s P-H. Spaak was surnamed «Mr. Europe»
juergspaak/plankton_foodweb: Mechanistic models of trophic interactions: opportunities for species richness and challenges for modern coexistence theory
No full textVersion of the code at time of publication of corresponding paper in "The American Naturalist", titled:
Mechanistic models of trophic interactions: opportunities for species richness and challenges for modern coexistence theory
By J.W. Spaak, P. B. Adler and S. P. Ellne
The Scope of Legal Positivism: Validity or Interpretation?
No full textSpaak argues that legal positivists need to consider the social thesis in light of an important distinction between two levels of legal thinking, namely, the level of the sources of law (existence) and the level of the interpretation and application of law (content), and that they have good reason to restrict the scope of the social thesis to the level of the sources of law. He argues that by restricting the scope of the social thesis in this way, inclusive legal positivists can avoid having to assume that moral judgements can be true in a non-relative way, that exclusive legal positivists can avoid having to say that judges are creating new law instead of applying pre-existing law, if and insofar as they invoke normative considerations in their interpretation and application of the law, and that both inclusive and exclusive legal positivists can avoid Dworkin’s theoretical disagreement objection.</p
The contribution of differential hatching success to the fitness of species and interspecific hybrids
No full textResting egg banks of microcrustaceans have been used to reconstruct the evolutionary and ecological history of species. However, recent studies provided evidence for a discrepancy between dormant propagules in the sediment and the planktonic population. This pattern raises two questions: First, what is the value of data on resting egg banks for population dynamics over time and second, which component of the reproductive cycle causes the observed inconsistency? In our study we focussed on the second question by comparing the taxon composition of a resting egg bank with the reproductive success of ex-ephippial hatchlings. Species and interspecific hybrid identification of dormant and hatched stages was achieved through the application of restriction fragment length polymorphism analysis of an internal transcribed spacer region. We found no significant deviation between the proportion of hatched Daphnia galeata, D. galeata x hyalina and D. hyalina individuals and the observed taxon composition of the resting egg bank. However, species and hybrids differed in their mode and relative success of reproduction. We conclude that the components of reproductive success in Daphnia contribute differentially to the fitness of species and interspecific hybrids. The discrepancy between resting egg banks and "active" planktonic populations results not from differential hatching of species but from the reproductive success of ex-ephippial females and the timing and frequency of sexual reproduction of the different taxa
sj-pdf-1-pss-10.1177_09567976211032676 – Supplemental material for Scene Context Impairs Perception of Semantically Congruent Objects
No full textSupplemental material, sj-pdf-1-pss-10.1177_09567976211032676 for Scene Context Impairs Perception of Semantically Congruent Objects by Eelke Spaak, Marius V. Peelen and Floris P. de Lange in Psychological Science</p
Cardiovascular function after long-term bed rest
No full textOn earth, daily activities involve standing, changes of posture and various types of muscle action, all of which challenge the cardiovascular regulation. Removal of the orthostatic stress for a longer period, as during spaceflight or head-down tilt bed rest, consistently results in cardiovascular deconditioning.The principal aim of this thesis was to improve the understanding of cardiovascular deconditioning, as reflected in altered structure and control after long-term spaceflight and bed rest. Apart from an initial methodological study, all results are based on two head-down tilt bed rest experiments with durations of 42 and 120 clays, and on five spaceflights with durations of 6 to 13 months.In the initial study, the separate effects of voluntary motor activation and muscle chemoreflex activation on arterial baroreflexes in healthy young men were examined. It was found that the elevation of arterial blood pressure is mainly caused by muscle ischemia, whereas the heart rate response is entirely due to somatomotor activation.These conclusions provided a basis for the following study, aiming to characterized the cardiovascular responses to isometric muscle action during and after spaceflight and after bed rest. The responses to isometric lower arm contraction were determined, and it was concluded that impaired cardiovascular responses to isometric muscle action do contribute to the cardiovascular deconditioning after spaceflight and bed rest.In the two bed rest studies, cardiac output (CO) and stroke volume (SV) were determined, and marked reductions were found in both CO and SV, in both supine and upright posture, during rest and during 50 watt pedalling. The time-course of the deconditioning and recovery of SV in the different conditions indicates that SV reductions in the upright posture after bed rest are mainly due to an impaired preload, and recuperate swiftly as plasma volume recovers. On the other hand, SV reductions in the supine posture during exercise, showed a slow, progressive decline during bed rest, and a protracted recovery after bed rest, strongly suggesting an altered cardiac morphology and probably a decreased heart size.In the 120-day bed rest study, impairments in blood pressure control during rest and exercise were also assessed. It was found that bed rest causes markedly increased blood pressure deviations during rapid tilts at exercise, indicating impaired reflex and/or effector organ function. Furthermore, it was found that bed rest causes attenuated baroreflex sensitivity for chronotropic responses to arterial pressure stimuli, although this appears to be of modest functional significance.The finding of a reduced degree of mechanical interaction between the two ventricles provided indirect evidence of reduced cardiac size during and after bed rest. Hemodynamic and baroreflex impairments had similar time courses, suggesting that reductions of cardiac size may be a common denominator for both of these types of hemodynamic and baroreflex impairments. Despite these changes, the ability to maintain the arterial blood pressure during steady state conditions was found to be preserved after bed rest.List of scientific papersI. Spaak J, Sundblad P, Linnarsson D (1998). "Human carotid baroflex during isometric lower arm contraction and ischemia." American Journal of Physiology 275(3 Pt 2): H940-5 https://pubmed.ncbi.nlm.nih.gov/9724298II. Spaak J, Sundblad P, Linnarsson D (2001). "Impaired pressor response after spaceflight and bed rest: evidence for cardiovascular dysfunction. " Eur J Appl Physiol 85(1-2): 49-55 https://pubmed.ncbi.nlm.nih.gov/11513320III. Sundblad P, Spaak J, Linnarsson D (2000). "Cardiovascular responses to upright and supine exercise in humans after 6 weeks of head-down tilt (-6 degrees). " Eur J Appl Physiol 83(4 -5): 303-9 https://pubmed.ncbi.nlm.nih.gov/11138568IV. Spaak J, Montmerle S, Sundbla P, Linnarsson D (2001). "Stroke volume during rest and exercise after 120 days bed rest." (Manuscript)V. Linnarsson D, Sundblad P, Spaak J (2001). "Hemodynamic and baroreflex to rapid posture changes after prolonged bed rest." (Manuscript)</p
Robert Alexy's Legal Constitutivism
No full textIn this chapter, I discuss Robert Alexy's dual-nature theory of law conceived as a version of legal constitutivism. Alexy argues (i) that legal acts necessarily raise a claim to correctness; (ii) that it follows from law's raising a claim to correctness that law has a dual nature; (iii) that the dual nature of law implies that legal acts that do not raise a claim to correctness, or raise one but fail to satisfy it, will lack legal character or else will be legally defective; (iv) that the dual nature of law is incompatible with the separation thesis of legal positivism; and (v) that it follows from law's dual nature that legal argumentation is a special case of general practical argumentation. Spaak argues, however, (A) that even if in some sense legal acts necessarily raise a claim to correctness, it does not follow that law has a dual nature; (B) that even if it did follow that law has a dual nature, it would not follow (i) that the separation thesis of legal positivism was false, or (ii) that legal argumentation was a special case of general practical argumentation; and (C) that this in turn suggests that constitutivists about practical reason are fighting an uphill battle.--
The stable isotopic composition of Daphnia ephippia reflects changes in d13C and d18O values of food and water
No full textThe stable isotopic composition of fossil resting eggs (ephippia) of Daphnia spp. is being used to reconstruct past environmental conditions in lake ecosystems. However, the underlying assumption that the stable isotopic composition of the ephippia reflects the stable isotopic composition of the parent Daphnia, of their diet and of the environmental water have yet to be confirmed in a controlled experimental setting. We performed experiments with Daphnia pulicaria cultures, which included a control treatment conducted at 12 °C in filtered lake water and with a diet of fresh algae and three treatments in which we manipulated the stable carbon isotopic composition (?13C value) of the algae, stable oxygen isotopic composition (?18O value) of the water and the water temperature, respectively. The stable nitrogen isotopic composition (?15N value) of the algae was similar for all treatments. At 12 °C, differences in algal ?13C values and in ?18O values of water were reflected in those of Daphnia. The differences between ephippia and Daphnia stable isotope ratios were similar in the different treatments (?13C: +0.2 ± 0.4 ‰ (standard deviation); ?15N: ?1.6 ± 0.4 ‰; ?18O: ?0.9 ± 0.4 ‰), indicating that changes in dietary ?13C values and in ?18O values of water are passed on to these fossilizing structures. A higher water temperature (20 °C) resulted in lower ?13C values in Daphnia and ephippia than in the other treatments with the same food source and in a minor change in the difference between ?13C values of ephippia and Daphnia (to ?1.3 ± 0.3 ‰). This may have been due to microbial processes or increased algal respiration rates in the experimental containers, which may not affect Daphnia in natural environments. There was no significant difference in the offset between ?18O and ?15N values of ephippia and Daphnia between the 12 and 20 °C treatments, but the ?18O values of Daphnia and ephippia were on average 1.2 ‰ lower at 20 °C than at 12 °C. We conclude that the stable isotopic composition of Daphnia ephippia provides information on that of the parent Daphnia and of the food and water they were exposed to, with small offsets between Daphnia and ephippia relative to variations in Daphnia stable isotopic composition reported from downcore studies. However, our experiments also indicate that temperature may have a minor influence on the ?13C, ?15N and ?18O values of Daphnia body tissue and ephippia. This aspect deserves attention in further controlled experiment
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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