Vrije wil en verantwoordelijkheid in evolutionair perspectief

In toenemende mate dragen evolutiebiologen en neurowetenschappers het idee uit dat onze praktijk van verantwoordelijkheid in het licht van de evolutietheorie niet te handhaven is. Hun argumentatie berust op de veronderstelling dat die praktijk alleen gerechtvaardigd is als mensen het vermogen hebben om zich aan de natuurwetten te onttrekken. In dit hoofdstuk betoog ik dat onze praktijk van verantwoordelijkheid slechts het vermogen om op basis van redenen te handelen veronderstelt en dat dit vermogen zich in de biologische strijd om het bestaan ontwikkeld kan hebben

Atrial fibrillation in chronic heart failure patients with reduced ejection fraction: The CHECK-HF registry

Background: Atrial fibrillation (AF) is common in chronic heart failure (HF) patients and influences the choice and effects of drug and device therapy. In this large real-world HF registry, we studied whether the presence of AF affects the prescription of guideline-recommended HF therapy. Methods: We analyzed 8253 patients with chronic HF with reduced ejection fraction (HFrEF) from 34 Dutch outpatient clinics included in the period between 2013 and 2016 treated according to the 2012 ESC guidelines. Results: 2109 (25.6%) of these patients were in AF (mean age 76.8 ± 9.2 years, 65.0% were men) and 6.144 (74.4%) had no AF (mean age 70.7 ± 12.2 years, 63.6% were men). Patients with AF more often received beta-blockers (81.7% vs. 79.7%, p = 0.04), MRAs (57.1% vs. 51.7%, p < 0.01), diuretics (89.7% vs. 80.6%, p < 0.01) and digoxin (40.1% vs. 9.3%, p < 0.01) compared to patients without AF, whereas they less often receive renin-angiotensin-system (RAS)-inhibitors (76.1% vs. 83.1%, p < 0.01). The number of patients who received beta-blockers, RAS-inhibitor and MRA at ≥50% of the recommended target dose was comparable between those with and without AF (16.6% vs. 15.2%, p = 0.07). Conclusion: In this large cohort of chronic HFrEF patients, the prevalence of AF was high and we observed significant differences in prescription of both guideline-recommended HF between patients with and without AF

The BCN Challenge to Compatibilist Free Will and Personal Responsibility

Many philosophers ignore developments in the behavioral, cognitive, and neurosciences that purport to challenge our ideas of free will and responsibility. The reason for this is that the challenge is often framed as a denial of the idea that we are able to act differently than we do. However, most philosophers think that the ability to do otherwise is irrelevant to responsibility and free will. Rather it is our ability to act for reasons that is crucial. We argue that the scientific findings indicate that it is not so obvious that our views of free will and responsibility can be grounded in the ability to act for reasons without introducing metaphysical obscurities. This poses a challenge to philosophers. We draw the conclusion that philosophers are wrong not to address the recent scientific developments and that scientists are mistaken in formulating their challenge in terms of the freedom to do otherwise

Air-water interfacial properties of enzymatically hydrolyzed wheat (T. aestivum L.) gluten

Food foams usually consist of dispersed air bubbles in an aqueous phase. They play important structural and textural roles in many foods and beverages, such as meringues, cakes, whipped dairy products and beer. While they are not stable, they can be stabilized by surface active ingredients such as most proteins. Traditionally, egg white and milk proteins have been used in many food systems, because of their excellent functional and organoleptic properties. However, the production of proteins from animal sources is rather expensive and has a significant environmental impact. That of plant proteins is cheaper and more sustainable. Unfortunately, many plant proteins are not soluble in water, due to previous processing or to their innate structure, or they lack functionality. A notable example are wheat gluten proteins. Such proteins are obtained industrially as a co-product of the wheat starch isolation process. They can be enzymatically hydrolyzed which renders them soluble in water and also induces foaming properties. Current literature on foaming and air-water interfacial properties of wheat gluten or other plant protein hydrolysates for that matter in most cases reports on the outcome of relatively simple studies. A thorough evaluation of the relationship between structure and function of such hydrolysates is only rarely considered. Furthermore, as protein hydrolysate functionality is often assessed in relatively simple aqueous solutions, the complexity of food products is in many instances underestimated. Other food constituents may have a profound impact on the foaming of plant protein hydrolysates. Against this background, this dissertation aimed to provide insights in the structure-function relationship of enzymatically hydrolyzed wheat gluten in conditions relevant to food systems. Trypsin and pepsin were used to hydrolyze wheat gluten to degrees of hydrolysis of 2 and 6 (DH 2 and DH 6), which yielded four structurally different samples of gluten hydrolysates. In a first part, the relationship between the foaming and air-water interfacial characteristics of gluten hydrolysates was established. The foaming capacity of the gluten hydrolysates, which was defined as the initial amount of foam formed, could be related to the rate at which they diffused to an air-water interface. Furthermore, hydrolysates with a degree of hydrolysis of 2 had better foam stability, which was the remaining foam volume after 60 min, than hydrolysates with a degree of hydrolysis of 6. This could be related to the former being able to form protein films at the air-water interface with higher strength than the latter. The structural features of the peptides responsible for the air-water interfacial behavior were studied in-depth by performing foam fractionation experiments. It was shown that the presence of some specific very hydrophobic peptides with relatively high molecular mass rather than the overall hydrophobicity or molecular mass distribution of a sample was crucial to its ability to effectively stabilize an interface. These insights on the air-water interfacial characteristics of gluten hydrolysates in relatively simple aqueous solutions were of great value to further study their behavior in conditions more similar to those found in food systems. In a second part, the air-water interfacial and foaming properties of gluten hydrolysates were assessed in gradually more complex systems to obtain an image of how such hydrolysates would behave in food relevant media. In a first step, the impact of varying the pH was investigated. Interestingly, tryptic and peptic hydrolysates were affected in different ways. At pH 7.0, which was close to conditions tested in the earlier chapters, tryptic and peptic hydrolysates with the same degree of hydrolysis had rather similar foam stability values. At pH 5.0, all hydrolysates had low foam stability, because of the proximity to their point-of-zero-charge. However, at pH 3.0, tryptic and peptic hydrolysates had high and extremely low foam stability, respectively. It was found that pH-induced changes in peptide conformation and aggregation state were probably related to this. A second step consisted of evaluating the impact of sucrose and ethanol, which are common in some food foams, on the air-water interfacial characteristics of the gluten hydrolysates. Both sucrose and ethanol increased the foaming capacity of all of the gluten hydrolysates. Indeed, the affinity for the air-water interface of the gluten hydrolysates was higher in a sucrose solution than in water, as was observed by increased rates of diffusion to and adsorption at the interface. However, the affinity of the gluten hydrolysates for the interface was lower in the presence of ethanol. The surface tension lowering effect of ethanol probably explained the higher foam capacity values of the hydrolysates in ethanol solution. The impact of the sucrose and ethanol on foam stability of the hydrolysates depended on the protein concentration. At low concentrations, the foam stability was very low both in the presence of sucrose or ethanol. With increasing protein concentration, the foam stability of the hydrolysates in sucrose or ethanol solutions increased to values similar to those in water. It was concluded that food constituents can impact the foaming properties of protein hydrolysates. In a final step, the impact of egg white proteins, which can also stabilize foams, on the interfacial behavior of gluten hydrolysates was investigated. On their own, solutions of gluten hydrolysates had much higher foaming capacities than those of egg white proteins, while the latter had much higher foam stability than the former. When only one sixth of egg white proteins were replaced by any of the gluten hydrolysates, the foaming capacity of the mixture was as high as or higher than that of the gluten hydrolysate solutions. Furthermore, even when half of the egg white proteins were replaced by gluten hydrolysates, these mixtures still had high foam stability. Thus, it seems that both gluten hydrolysates and egg white proteins contribute positively to the foaming characteristics of the mixtures. However, measurements of the rates of diffusion to and adsorption at the interface, and of protein film strength at the interface suggested that the adsorbed protein film mostly consisted of gluten hydrolysates. It is hypothesized that egg white proteins form a secondary protein layer below the air-water interface which is maintained by protein – protein interactions with the gluten hydrolysates and provides air bubbles in foam with an additional resistance to bubble coalescence. Finally, as a proof-of-concept, gluten hydrolysates were incorporated in a meringue recipe as a replacement for egg white protein. Meringues containing gluten hydrolysates had better batter and final product properties than those purely based on egg white protein. Thus, enzymatically produced gluten hydrolysates can be a valid alternative for egg white proteins in meringues and possibly other food products.nrpages: 198status: publishe

Cereal protein-based nanoparticles as agents stabilizing air–water and oil–water interfaces in food systems

There has been a recent surge of interest in the use of food-grade nanoparticles (NPs) for stabilizing food foams and emulsions. Cereal proteins are a promising raw material class to produce such NPs. Studies thus far have focused mostly on wheat gliadin and maize zein-based NPs. The former are effective interfacial stabilizing agents, while the latter due to their high hydrophobicity generally result in poor interfacial stability. Several strategies to modify the surface properties of wheat gliadin and maize zein NPs have been followed. In many instances, this resulted in improved foam or emulsion stability. Nonetheless, future efforts should be undertaken to gain fundamental insights in the interfacial behavior of NPs, to further explore NP surface modification strategies, and to validate the use of NPs in actual food systems.status: publishe

Protein nanoparticles to build food structure

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Impact of different protein sources in gluten-free bread making on crumb structure formation

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