A comprehensive study to assess the impact of impulsive sound on juvenile sea bass

Given the increasing amount of anthropogenically induced underwater sound into the marine environment, a better understanding of the impact of impulsive underwater sound on marine life is needed. This study tackles the impact of impulsive sound, related to pile-driving activities for offshore wind energy development, on the mortality, stress and behaviour of post-larval and juvenile European sea bass Dicentrarchus labrax. A 'worst-case scenario' field experiment was carried out on board of a piling vessel, exposing 68 and 115 days old fish (<2 g wet weight) to the sound generated during 1.5 hours of pile-driving. The number of strikes ranged from 1740 to 3070, with a single strike sound exposure level between 181 and 188 dB re 1 μPa².s, resulting in cumulative sound exposure levels ranging from 215 to 222 dB re 1 μPa².s. Immediate and long-term survival of the exposed fish was high and comparable to the control groups. However, juvenile fish responded to the impulsive underwater sound by a 50% reduction in their oxygen consumption rates, an indicator of secondary stress response. Primary stress responses, measured through cortisol levels are still to be analysed. We didn't find any effect on the condition and fitness of the exposed fish on the long term. Lab experiments performed with a SIG Sparker and a larvaebrator, respectively producing mid-high and lower frequencies, were inadequate to distinguish the determining sound metric or to pursue the exact origin of the stress response. Further away from the sound source, behavioural and masking effects can be expected. A lab experiment was carried out to study the behaviour of juvenile sea bass before, during and after one hour of impulsive sound exposure. In the aquaria, single strike sound levels reached 162 dB re 1 μPa².s, leading to a cumulative sound exposure level of 196 dB re 1 μPa².s after 2400 strikes. We observed that normal behaviour was disturbed, with an increase in startle responses and stationary behaviour at the beginning of the sound exposure experiment. Also, fish dived to the bottom of the aquaria, which is a typical anxiety-related response. However, no spatial preference was observed and normal behaviour was re-established shortly after the sound exposure ceased. These results indicate that impulsive sound close to the sound source creates sound pressure levels that are below the lethal threshold for fish, but above the stress threshold, at least for sea bass <2 g. Furthermore, lower sound levels at a distance from the sound source (in this case pile-driving) can disturb fish behaviour. Under optimal lab conditions, we did not see effects beyond the sound exposure period, but it remains unknown whether the reduced fitness of juvenile fish after exposure is limited in the real world as well

‘Buying a path’: rethinking resistance in Rwanda

In this essay, I tell the story of Jean-Baptiste, the president of a motorcycle taxi drivers’ co-operative, and his struggle against the machinations of certain high officials in Kigali City Council. Crucial to this story is the way in which Jean-Baptiste’s attempts to retain his position in the face of powerful opposition pit certain agencies of Rwanda’s party state against others. I use this ethnographic narrative to question the way in which much scholarship on popular resistance in Rwanda, drawing on Scott’s simplified opposition between the powerful and the powerless, opposes ‘ordinary Rwandans’ to ‘the state’ as monolithic entities with opposed interests. Theorising Jean-Baptiste’s story in terms of Rwandan idioms of relative power and influence, I suggest that such a Manichean view of power and resistance in Rwanda oversimplifies social realities. I propose instead a model of power and resistance that sees the state as a field of capacities and possible relationships that it presents for certain people, where ‘paths’ to influence and security may by ‘bought’ – especially, but not exclusively, by those who are ‘strong’ and ‘high’

Reweighted smooth tests of goodness of fit

Starting from a smooth test for goodness of fit we develop a method to alter this test to a reweighted smooth test, which has greater power to a certain directional alternative. Whereas the original smooth test gives equal weight to the different directions in the space of alternatives, the reweighted smooth test makes a distinction in importance of the directions. The advantage of this test, as opposed to directional tests, is that the smooth character is largely maintained. We discuss both nested and non nested directional alternatives

Heterosis and responses to selection in orange fleshed sweetpotato (Ipomoea batatas L.) improved using reciprocal recurrent selection

Sweetpotato is a highly heterozygous hybrid, and populations of orange-fleshed sweetpotato (OFSP) have a considerable importance for food security and health. The objectives were to estimate heterosis increments and response to selection in three OFSP hybrid populations (H&lt;sub&gt;1&lt;/sub&gt;) developed in Peru for different product profiles after one reciprocal recurrent selection cycle, namely, H&lt;sub&gt;1&lt;/sub&gt; for wide adaptation and earliness (O-WAE), H&lt;sub&gt;1&lt;/sub&gt; for no sweetness after cooking (O-NSSP), and H&lt;sub&gt;1&lt;/sub&gt; for high iron (O-HIFE). The H&lt;sub&gt;1&lt;/sub&gt; populations were evaluated at two contrasting locations together with parents, foundation (parents in H&lt;sub&gt;0&lt;/sub&gt;), and two widely adapted checks. Additionally, O-WAE was tested under two environmental conditions of 90-day and a normal 120-day harvest. In each H&lt;sub&gt;1&lt;/sub&gt;, the yield and selected quality traits were recorded. The data were analyzed using linear mixed models. The storage root yield traits exhibited population average heterosis increments of up to 43.5%. The quality traits examined have exhibited no heterosis increments that are worth exploiting. The storage root yield genetic gain relative to the foundation was remarkable: 118.8% for H&lt;sub&gt;1&lt;/sub&gt;-O-WAE for early harvest time, 81.5% for H&lt;sub&gt;1&lt;/sub&gt;-O-WAE for normal harvest time, 132.4% for H&lt;sub&gt;1&lt;/sub&gt;-O-NSSP, and 97.1% for H&lt;sub&gt;1&lt;/sub&gt;-O-HIFE. Population hybrid breeding is a tool to achieve large genetic gains in sweetpotato yield via more efficient population improvement and allows a rapid dissemination of globally true seed that is generated from reproducible elite crosses, thus, avoiding costly and time-consuming virus cleaning of elite clones typically transferred as vegetative plantlets. The population hybrid breeding approach is probably applicable to other clonally propagated crops, where potential for true seed production exists

Phenotyping of productivity and resilience in sweetpotato under water stress through UAV‐based multispectral and thermal imagery in Mozambique

International audienc

IL-12 contributes to allergen-induced airway inflammation in experimental asthma

Lack of sufficient IL-12 production has been suggested to be one of the basic underlying mechanisms in atopy, but a potential role of IL-12 in established allergic airway disease remains unclear. We took advantage of a mouse model of experimental asthma to study the role of IL-12 during the development of bronchial inflammation. Administration of anti-IL-12p35 or anti-IL-12p40 mAb to previously OVA-sensitized BALB/c mice concomitantly with exposure to nebulized OVA, abolished both the development of bronchial hyperresponsiveness to metacholine as well as the eosinophilia in bronchoalveolar lavage fluid and peripheral blood. Anti-IL-12 treatment reduced CD4(+) T cell numbers and IL-4, IL-5, and IL-13 levels in the bronchoalveolar lavage fluid and the mRNA expression of IL-10, eotaxin, RANTES, MCP-1, and VCAM-1 in the lung. Anti-IL-12p35 treatment failed to show these effects in IFN-gamma knockout mice pointing to the essential role of IFN-gamma in IL-12-induced effects. Neutralization of IL-12 during the sensitization process aggravated the subsequent development of allergic airway inflammation. These data together with recent information on the role of dendritic cells in both the sensitization and effector phase of allergic respiratory diseases demonstrate a dual role of IL-12. Whereas IL-12 counteracts Th2 sensitization, it contributes to full-blown allergic airway disease upon airway allergen exposure in the postsensitization phase, with enhanced recruitment of CD4(+) T cells and eosinophils and with up-regulation of Th2 cytokines, chemokines, and VCAM-1. IFN-gamma-producing cells or cells dependent on IFN-gamma activity, play a major role in this unexpected proinflammatory effect of IL-12 in allergic airway disease.status: publishe

IL-12 contributes to allergen-induced airway inflammation in experimental asthma

Lack of sufficient IL-12 production has been suggested to be one of the basic underlying mechanisms in atopy, but a potential role of IL-12 in established allergic airway disease remains unclear. We took advantage of a mouse model of experimental asthma to study the role of IL-12 during the development of bronchial inflammation. Administration of anti-IL-12p35 or anti-IL-12p40 mAb to previously OVA-sensitized BALB/c mice concomitantly with exposure to nebulized OVA, abolished both the development of bronchial hyperresponsiveness to metacholine as well as the eosinophilia in bronchoalveolar lavage fluid and peripheral blood. Anti-IL-12 treatment reduced CD4(+) T cell numbers and IL-4, IL-5, and IL-13 levels in the bronchoalveolar lavage fluid and the mRNA expression of IL-10, eotaxin, RANTES, MCP-1, and VCAM-1 in the lung. Anti-IL-12p35 treatment failed to show these effects in IFN-gamma knockout mice pointing to the essential role of IFN-gamma in IL-12-induced effects. Neutralization of IL-12 during the sensitization process aggravated the subsequent development of allergic airway inflammation. These data together with recent information on the role of dendritic cells in both the sensitization and effector phase of allergic respiratory diseases demonstrate a dual role of IL-12. Whereas IL-12 counteracts Th2 sensitization, it contributes to full-blown allergic airway disease upon airway allergen exposure in the postsensitization phase, with enhanced recruitment of CD4(+) T cells and eosinophils and with up-regulation of Th2 cytokines, chemokines, and VCAM-1. IFN-gamma-producing cells or cells dependent on IFN-gamma activity, play a major role in this unexpected proinflammatory effect of IL-12 in allergic airway diseas