New spectra in the HEIDI Higgs models

We study the so-called HEIDI models, which are renormalizable extensions of the standard model with a higher dimensional scalar singlet field. As an additional parameter we consider a higher-dimensional mixing mass parameter. This leads to enriched possibilities compared to a previous study. We find effective spectral densities of the Higgs propagator, consisting of one, two or no particle peaks, together with a continuum. We compare with the LEP-2 data and determine for which range of the model parameters the data can be described. Assuming two peaks to be present we find for the new mass scale \nu\approx 56\pm12 \gev, largely independent of the dimension. In the limiting case of $d\rightarrow 6$ and two peaks we find a higher dimensional coupling constant $\alpha_6=0.70 \pm 0.18$, indicative of strong interactions among the higher dimensional fields. The LHC will not be able to study this Higgs field.Comment: 17 pages, 4 figure

Collective redress and workers' rights in the Netherlands

This contribution discusses the Dutch possibilities of collective redress in the domain of labour law. More specifically, it examines the legal options of bringing collective actions and obtaining collective redress in Dutch courts in labour cases, and elaborates on the relevant legal framework as well as the extent to which these opportunities have been used in practice. Findings imply that the Netherlands was among one of the first European countries to introduce a general collective action system. This general collective action regime allows unions and other interest groups to raise cases to protect workers’ rights, even outside the scope of collective labour agreements. Such a collective action regime, however, is not commonly used in practice. Nevertheless, as of January 2020 the admissibility criteria for this general collective redress mechanism have been expanded and it has become an ‘opt-out’ regime, without the need for individual workers to initiate individual follow-up proceedings in the event of a successful case. The latter could improve the effective enforcement of workers’ rights in practice and could provide an incentive for trade unions and other organisations that are active in the protection of workers’ rights to incite a collective action

Collective Intentionality and Individual Action

People often do things together and form groups in order to get things done that they cannot do alone. In short they form a collectivity of some kind or a group, for short. But if we consider a group on the one hand and the persons that constitute the group on the other hand, how does it happen that these persons work together and finish a common task with a common goal? In the philosophy of action this problem is often solved by saying that there is a kind of collective intention that the group members have in mind and that guides their actions. Does such a collective intention really exist? In this article I’ll show that the answer is “no”. In order to substantiate my view I’ll discuss the approaches of Bratman, Gilbert and Searle on collective intention. I’ll put forward four kinds of criticism that undermine the idea of collective intention. They apply mainly to Bratman and Gilbert. First, it is basically difficult to mark off smaller groups from bigger unities. Second, most groups change in membership composition over time. Third, as a rule, on the one hand groups are internally structured and on the other hand they belong to a larger structure. It makes that generally it cannot be a collective intention that moves the actions of the members of a group. Fourth, conversely, most individual actions cannot be performed without the existence of a wider context of agents who support these actions and make them possible. My critique on Searle mainly involves that in his approach his idea of collective intention is superfluous and that he is not radical enough in his idea that collective action is based on coordinated individual intentions and actions. However, it is a good starting point for showing how collective action actually functions, especially when combined with Giddens’s structuration theory. Every agent in a group executes his or her own individual intentions, relying on what the group offers to this agent and asks from him or her. In this way individual actions of the members of a group are coordinated and it makes that the group can function and that its goals can be performed. And in this way the group is produced and reproduced by fitting individual actions together. An individual agent who belongs to a group only needs to know what s/he wants and what s/he has to do in the group, even if s/he has no knowledge of the intentions and commitments of the other members. Then he or she can do things together with others in a group without supposing that there is something like a collective intention

A collaborative tool for mobilizing knowledge in agrobiodiversity and the interface with climate change: the Platform for Agrobiodiversity Research

Poster presented at 2nd ANAFE International Symposium. Lilongwe (Malawi), Jul 200

Unraveling Social Media Effects:How the Intertwinement of Online Content and User Behaviors Guides Mental Health and Body Image

The rapid growth in popularity of social media platforms has fueled concerns about the possible negative effects of social media use on young people’s mental health and body image. To unravel social media effects, scholars argued that social media activities should be divided into active and passive social media use. It has been hypothesized that active social media use (i.e., creating content) leads to positive effects on mental health and body image, whereas passive social media (i.e., viewing content) leads to negative effects. In some cases, however, active social media use appeared to also lead to more negative feelings about oneself and one’s life, while passive social media use can lead to more positive feelings about these matters. Hence, the active-passive dichotomy seems a rough division that needs further specification. What types of content do young people post online, and what do they passively consume? And how does that affect their mental health and body image? To advance our knowledge and insights on these matters, the overarching goal of this dissertation was to investigate if, when, and how social media use affects young people’s mental health and body image. In Chapter 2, findings of a systematic literature review indicated that how social media use coincides with mental health and body image largely depends on the content of the self-presentation created or passively consumed. For example, sharing negative life events was generally linked to decreased subjective well-being. In contrast, sharing authentic self-presentations was linked with increased subjective well-being. The second study (Chapter 3) examined how ethno-racial identities may predispose differences in publicly posted selfies. Facial recognition was used to classify the selfie-takers’ ethno-racial identity on over 3000 publicly posted selfies. Findings revealed that individuals varying in ethno-racial identity generally differed in their online self-presentations. For example, Asian and Hispanic selfie-takers posted more of their context and less of themselves than black and white selfie-takers. The third study in this dissertation examined how the prevalence of posting and seeing different photo-types was linked with mental health and body image (Chapter 4). This study included more than 400 adolescents. Findings of this study indicated that, for example, posting more authentic photos of oneself is associated with higher levels of mental health, whereas posting edited photos is associated with more body shame. The last study examined the potential longer-term impact of social media use (Chapter 5). This study included more than 400 Japanese adolescents and more than 500 Dutch adolescents. The adolescents completed three online surveys, with one-month intervals in between. Findings of this study indicated that both a higher frequency of posting and being exposed to authentic photos can induce positive outcomes for mental health and body image, whereas both a higher frequency of posting and being exposed to edited photos of others was found to relate to negative outcomes. Results were, however, different between Dutch and Japanese adolescents. The results of the studies in this dissertation generally conclude that time-based approaches of social media use reflect an oversimplification to interpret the possible effects on mental health and body image. The findings of this dissertation all advocate that there is a need to apply an integrated content-specific and behavior-specific approach. Moreover, social media effects are conditional, meaning that social media effects cannot be attributed to all adolescents and may vary across cultural context. Hence, if and when social media impacts mental health and body image largely depends on how and why they use social media as well as the way they respond to their social media use

Polderproject Woudse Droogmakerij: voorbeeldproject voor verbetering waterkwaliteit

Het Polderproject Woudse Droogmakerij moet leiden tot een meetbare verbetering van de waterkwaliteit met teeltmaatregelen die het rendement van de bedrijven garanderen of verbeteren. De kennis die ontstaat wordt landelijk ingezet om de emissie van gewasbeschermingsmiddelen en nutriënten vanuit de glastuinbouw te verminderen