Contrasting effects of heat pulses on different trophic levels, an experiment with a herbivore-parasitoid model system

Under predicted global climate change, species will be gradually exposed to warmer temperatures, and to a more variable climate including more intense and more frequent heatwaves. Increased climatic variability is expected to have different effects on species and ecosystems than gradual warming. A key challenge to predict the impact of climate change is to understand how temperature changes will affect species interactions. Herbivorous insects and their natural enemies belong to some of the largest groups of terrestrial animals, and thus they have a great impact on the functioning of ecosystems and on the services these ecosystems provide. Here we studied the life history traits of the plant-feeding insect Plutella xylostella and its specialist endoparasitoid Diadegma semiclausum, when exposed to a daily heat pulse of 5 or 10°C temperature increase during their entire immature phase. Growth and developmental responses differed with the amplitude of the heat pulse and they were different between host and parasitoid, indicating different thermal sensitivity of the two trophic levels. With a +5°C heat pulse, the adult parasitoids were larger which may result in a higher fitness, whereas a +10°C heat pulse retarded parasitoid development. These results show that the parasitoid is more sensitive than its host to brief intervals of temperature change, and this results in either positive or negative effects on life history traits, depending on the amplitude of the heat pulse. These findings suggest that more extreme fluctuations may disrupt host-parasitoid synchrony, whereas moderate fluctuations may improve parasitoid fitness. (Résumé d'auteur

Adjustment disorders after severe life-events in four postconflict settings

Background: The present study explores whether severe life-events are associated with adjustment disorders (AD) by reanalyzing the data of a multisite epidemiological survey (de Jong et al. in Lancet 361:2128-2130, 2003). AD were diagnosed according to the new stress-response-model of AD (Maercker et al. in Psychopathology 40(3):135-146, 2007). Method: Data from 3048 persons from four different refugee settings in Ethiopia, Algeria, Gaza, and Cambodia were reanalyzed. Life events were assessed by an adapted version of the Life Events and Social History Interview (Mollica et al. in Am J Psychiatry 144:1567-1572, 1987). The current study focuses on non-directly life threatening events related to AD (e.g. loss of property) in contrast to life-threatening events related to Posttraumatic Stress Disorders (PTSD). AD Symptom measures were obtained from available psychopathology assessments: composite international diagnostic interview (WHO in CIDI, Geneva, 1997) and structured interview for disorders of extreme stress (Pelcovitz et al. J Trauma Stress 10:3-16, 1997). Results: The majority of the subjects had experienced one or more AD-related life event. Most common AD-related life events varied across the four sites with bad shelter conditions most prevalent in Ethiopia (100%) and Gaza (32%), forced social isolation in Algeria (61%), and lack of food in Cambodia (41%). Prevalences of AD diagnoses ranged from 6% (Ethiopia) to 40% (Algeria). The highest rates of comorbidity were between AD and PTSD, followed by anxiety disorders. Conclusion: The present study shows that the new concept of AD can be of use for psychiatric epidemiology, e.g., in migration contexts. The high-comorbidity rates could indicate that AD and PTSD are parts of a stress response spectru

Implementing evidence based policy in a network-setting. Dutch Road Safety Policy in a shift from a Home to an Away Match

Abstract In order to improve road safety in the Netherlands, in 1992 the Institute for Road Safety Research (SWOV) developed the evidence-based ‘Sustainable Safety’ concept. Dutch road safety policy, based on this concept, was quite successful and seen as a best practice in Europe. Recently the p

Personalities in female domesticated pigs: behavioural and physiological indications

The inconclusive evidence so far on the existence of distinct personality types in domesticated pigs, led us to perform the present experiment. A total of 128 gilts from 31 sows were systematically studied from birth to slaughter in two identical trials. Intra-test consistency in individual behavioural andror physiological reactions was studied in three different tests. We were not able to show consistencies in reactions of gilts over time to a backtest (at 2–4 days and 4 weeks of age) and to a novel environment test (at 10 and 24 weeks of age). Individual aggression, however, as measured in a group-feeding competition test in stable groups (at 10 and 24 weeks of age), proved to be highly consistent. Explanations for these discrepancies in intra-test consistencies are critically discussed. Inter-test consistencies were determined by relating the individual reactions of gilts to the backtest to various characteristics and responses to tests at a later age. The highest correlations were found when resistance in the first backtest was involved. No evidence was found for the existence of specific isolated categories of animals with respect to this resistance. For further analysis, extreme responding gilts in the first backtest (roughly the top and bottom 25% of the distribution) were classified as low resistant (LR; <3 escape attempts; n=31) or high resistant (HR; >4 escape attempts; n=45). By comparisons of mean responses of LR and HR gilts within groups, we have established a relationship between the backtest and several other variables. Behaviourally, the HR gilts showed more aggression in the group-feeding competition tests. Also, in the competition for the most productive teats at the anterior, a predominant position of HR piglets at this site was observed during the suckling period. The latter piglets also gained more weight during this period than LR ones. Compared to HR pigs, in the first novel environment test LR pigs hesitated longer to leave their home pens and to contact a human, but no difference in their locomotory behaviour was observed. Contrasts between LR and HR pigs in the second novel environment test were reduced or absent. Physiologically, when compared to HR gilts, LR ones had a higher reactivity of the hypothalamic–pituitary–adrenocortical (HPA) system. This was shown by higher cortisol responses to the first novel environment test, to routine weighing at 25 weeks of age, and to administration of a high dose of ACTH. It is discussed that these findings for LR and HR gilts, may provide support for the existence of behavioural and physiological responses in pigs, resembling those of proactive and reactive rodents.

The introduction of public-private partnerships in the Netherlands as a case of institutional bricolage: The evolution of an Anglo-Saxon transplant in a Rhineland context

In this contribution, the introduction of contractual public-private partnerships (PPPs) in the Netherlands, more specifically the use of Design, Build, Finance, Maintenance, and Operations (DBFMO) contracts in Dutch infrastructure management, is analysed using a specific strand within the policy transfer and institutional transplantation literature: that of 'institutional bricolage'. This perspective states that policy transplants come to fit their new institutional context stepwise. This contribution reconstructs the adoption process by which the Anglo-Saxon-inspired PPP practice is incorporated into the traditional 'Rhinelandic' practice of infrastructure management in the Netherlands, identifying four waves of PPP initiatives. It concludes that these waves and the difficulties that emerge in them stem from an ongoing struggle between actor coalitions, one aiming to preserve the transplant in its original shape, and others making attempts at bricolage. Shifts in power relations explain the progress and outcomes of the process of institutional transplantation

Perverse incentives and invisible tradeoffs in subway construction in China: a case study of Hangzhou subway collapse

Abstract—Hangzhou subway collapse is the most serious subway construction disaster to date in China. In this article, the management and regulatory questions the collapse raised are focused and a case study of Hangzhou subway collapse is given. By regarding the contractual arrangement as an outcome of a power game of principal-agent, the social causes and the perverse incentives to strategic behaviors of the key players are investigated to explain the particular project outcomes. In the end, some policy suggestions are given for improving the safety performance of subway construction

Artists don't stop:but the position of many independend professionals is precarious

In dit onderzoek is de beroepspraktijk onderzocht van zelfstandige kunstprofessionals die (ook)werken in de cultuureducatie en amateurkunst, dus werken met amateurs/leerlingen/deelnemers.We hebben daartoe literatuuronderzoek gedaan en veldonderzoek (vragenlijst en interviews) inDrenthe en Limburg. De uitkomsten voor deze provincies zijn onderling goed vergelijkbaar. Ook wijkenze wat betreft belangrijke aspecten als inkomen en werkzekerheid, vrijheid, zelfstandigheid, hetkunnen benutten van het artistieke vakmanschap en de maatschappelijke waardering, niet wezenlijkaf van wat uit onderzoek over Nederland als geheel bekend is. De eerste twee werkaspecten wordennegatief ervaren, de andere juist als positief