The effect of canopy position on growth and mortality in mixed sapling communities during self-thinning

This research investigates how species in the sapling phase differ in growth and survival depending on light availability (as estimated by canopy position) by means of tree-ring analysis and modelling mortality. We harvested 120 live and 158 dead saplings in self-thinning communities consisting of Silver birch (Betula pendula Roth.), Scots pine (Pinus sylvestris L.), Japanese larch (Larix kaempferi Carr.) and Douglas fir (Pseudotsuga menziesii Mirb. Franco) in the Netherlands. Results are evaluated within the framework of a trade-off between high-light growth and low-growth survival. Radial growth, measured at ground level, generally declined over time. In addition, a decreasing light availability further reduced growth in all species except Douglas fir. Trees died when radial growth was reduced to about 0.5 mm year¿1. Mortality in all species except Scots pine was significantly related to recent growth, but mortality curves were not different. The light-demanding Silver birch and Japanese larch differed from the shade-tolerant Douglas fir in both high-light growth and low-growth mortality, in line with a growth-survival trade-off. The light-demanding Scots pine did not fit this pattern as it was unable to transfer high radial growth into height gain, leaving it in suppressed canopy positions. This indicates the importance of height growth in the growth-survival trade-off. Differences in mortality probabilities affect the potential for coexistence, however, in all species also fast-growing individuals died suggesting additional factors causing mortality during self-thinning, other than direct competition for ligh

Pupil dilation reflects effortful action invigoration in overcoming aversive Pavlovian biases

“Pavlovian” or “motivational” biases describe the phenomenon that the valence of prospective outcomes modulates action invigoration: Reward prospect invigorates action, whereas punishment prospect suppresses it. The adaptive role of these biases in decision-making is still unclear. One idea is that they constitute a fast-and-frugal decision strategy in situations characterized by high arousal, e.g., in presence of a predator, which demand a quick response. In this pre-registered study (N = 35), we tested whether such a situation—induced via subliminally presented angry versus neutral faces—leads to increased reliance on Pavlovian biases. We measured trial-by-trial arousal by tracking pupil diameter while participants performed an orthogonalized Motivational Go/NoGo Task. Pavlovian biases were present in responses, reaction times, and even gaze, with lower gaze dispersion under aversive cues reflecting “freezing of gaze.” The subliminally presented faces did not affect responses, reaction times, or pupil diameter, suggesting that the arousal manipulation was ineffective. However, pupil dilations reflected facets of bias suppression, specifically the physical (but not cognitive) effort needed to overcome aversive inhibition: Particularly strong and sustained dilations occurred when participants managed to perform Go responses to aversive cues. Conversely, no such dilations occurred when they managed to inhibit responses to Win cues. These results suggest that pupil diameter does not reflect response conflict per se nor the inhibition of prepotent responses, but specifically effortful action invigoration as needed to overcome aversive inhibition. We discuss our results in the context of the “value of work” theory of striatal dopamine

Economic modelling of pork production-marketing chains

The research described in this thesis was focused on the development of economic simulation and optimization computer models to support decision making with respect to pork production- marketing chains. The models include three production stages: pig farrowing, pig fattening and pig slaughtering including cutting of carcasses. Transportation of live pigs between these stages was also considered. The pork chain simulation model was developed and described to simulate technical and economic performance of both individual stages and pork chains as a whole. Special attention was focused on the quantification of the way in which stages can influence each other's performance and profitability. The simulation model was used to analyse the distribution of costs and benefits along the stages of the pork chain using various transfer pricing systems. Besides the chain producing standard pork, three differentiated pork chain concepts were evaluated. The simulation model was also used to quantify the impact of pig welfare demands on the economics of the pork chain. Pig welfare perceptions were assessed from animal welfare experts, retailers and other consumer-related respondents using a questionnaire based on conjoint analysis. The estimated pig welfare perceptions and corresponding economics were used as input parameters for static and dynamic linear programming models to analyse the development of least-cost chain concepts satisfying increasing demands on pig welfare. Additionally, the optimization models were extended using multi-criteria- decision-making techniques to include the effects on nitrogen and phosphorus emissions and energy consumption in pig farming as well

Interaction between current imbalance and magnetization in LHC cables

The quality of the magnetic field in superconducting accelerator magnets is associated with the properties of the superconducting cable. Current imbalances due to coupling currents ¿I, as large as 100 A, are induced by spatial variations of the field sweep rate and contact resistances. During injection at a constant field all magnetic field components show a decay behavior. The decay is caused by a diffusion of coupling currents into the whole magnet. This results in a redistribution of the transport current among the strands and causes a demagnetization of the superconducting cable. As soon as the field is ramped up again after the end of injection, the magnetization rapidly recovers from the decay and follows the course of the original hysteresis curve. In order to clarify the interactions between the changes in current and magnetization during injection the authors performed a number of experiments. A magnetic field with a spatially periodic pattern was applied to a superconducting wire in order to simulate the coupling behavior in a magnet. This model system was placed into a stand for magnetization measurements and the influence of different powering conditions was analyze

Adiabatic normal zone development in MgB2 superconductors

A-priori knowledge of the normal zone development in MgB/sub 2/ conductors is essential for quench protection of applications. Therefore the normal zone propagation in a monofilament MgB/sub 2//Fe conductor under near-adiabatic conditions at 4.2 K has been measured and simulated. The results show normal zone propagation velocities up to several meters per second. In addition, by including the voltage-current relation into the computational model, the influence of the n-value on the normal zone propagation is determined. The simulations show that lower n-values suppress the normal zone propagation velocity due to lower heat generation in the MgB/sub 2/ filaments

Care transformation defined by conditions, mechanisms, and outcomes: a systematic literature review

AbstractBackgroundQuality of care is under pressure due to demographic changes (shifting age of the population), epidemiological trends (more chronic diseases) and changes in the external environment (rapid development of technological innovations). Transformation in care is essential to deal with these changes. However, there is no consensus in the literature regarding the definition and factors contributing to care transformation.MethodsThis systematic review systematically searched the scientific databases Scopus, Web of Science and Pubmed until 22 January 2022. We included articles that focused on care transformation from a complex setting and multi-level perspective, with an empirical or theoretical rationale and methodology. Relevant data regarding the interconnection between contextual conditions, mechanism of change and outcomes were analysed using deductive coding. The generic contextual conditions-mechanisms outcome structure (CMO) [54]Pawson &amp; Tilly, 1997) was used as a framework to synthesise the results.ResultsNineteen articles were included. All related articles explain transformation from a complex systems perspective. Four of the 19 articles gave a definition of care transformation. These definitions of care transformation have the following in common: It involves radical and far-reaching change at an organisational and system-wide level, with the aim of improving performance, behaviour, efficiency, and quality of care, both at individual and population level. Relevant contextual conditions were the changing environment, organisational conditions, collaboration, direction of change and sources of funding. Relevant mechanisms for change were collaboration, leadership, interpersonal relationships, engagement, information technology and coordination. The key outcomes of care transformation are Integration of care, patient-centred care, and improvement of quality of care.ConclusionsAn important goal of care transformation is to deliver better quality of care and enable care integration. This study showed that effective collaboration among healthcare providers, supported by transformational leadership, strong interpersonal relationships, and coordination from multiple perspectives, play an important role in facilitating care transformation. Collaboration is an important mechanism for achieving the key outcomes of care transformation. Keywords: transformation, complex systems, collaboration, multi-level perspective, Quality of Healthcare<br/

Development of an experimental 10 T Nb3Sn dipole magnet for the CERN LHC

An experimental 1-m long twill aperture dipole magnet developed using a high-current Nb3Sn conductor in order to attain a magnetic field well beyond 10 T at 4.2 K is described. The emphasis in this Nb3Sn project is on the highest possible field within the known Large Hadron Collider (LHC) twin-aperture configuration. A design target of 11.5 T was chosen

Critical current degradation in HTS wires due to cyclic mechanical strain

HTS wires, which may be used in many devices such as magnets and rotating machines, may be subjected to mechanical strains from electromagnetic, thermal and centripetal forces. In some applications these strains will be repeated several thousand times during the lifetime of the device. We have measured critical current degradation due to repeated strain cycles for both compressive and tensile strains. Results for BSCCO-2223 HTS conductor samples are presented for strain values up to 0.5% and cycle numbers up to and beyond 10/sup 4/