Search results for " effects"

Perception-Based Study on the Value of Nature to People and Land Sparing for Nature in Brazil and Poland

2020

Understanding perception about nature is paramount to understanding human behavior and decision making on the environment. We performed a survey-based study in Brazil and Poland to better understand the perception of land sparing for nature and the perceived value of nature. The countries were selected by intentional sampling and given their importance for local and global biodiversity conservation, and complex socio-ecological context of conservation versus agroforestry business. We performed an online questionnaire (N = 1030) in Brazil and face-to-face interviews in Poland (N = 322). We found that Brazilian respondents demonstrated more pro-environmental attitudes than Polish survey parti…

Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest insect

2012

Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affect…

Risk of inbreeding : problem of mate choice and fitness effects?

2016

Mating with close kin may cause inbreeding depression with negative consequences to offspring and local populations. There exist mechanisms like kin-recognition or sex-specific dispersal to avoid mating with kin. In fluctuating population densities, like in many small mammals, both very low and very high densities provide conditions for inbreeding, if kin males are prone to stay in their natal area. Females are choosy and male dominance is thought to be the key feature when selecting mating partners. The aim of this study was to test the possible discrepancy in mate choice and negative fitness effects of inbreeding in two experiments, one in the laboratory and one in field enclosures. We as…

Transgenerational effects decrease larval resilience to ocean acidification & warming but juvenile European sea bass could benefit from higher te…

2021

1.AbstractThe aim of this study was to investigate the effect of ocean acidification (OA) and warming (OW) as well as the transgenerational effect of OA on larval and juvenile growth and metabolism of a large economically important fish species with a long generation time. Therefore we incubated European sea bass from Brittany (France) for two generations (>5 years in total) under current and predicted OA conditions (PCO2: 650 and 1700 µatm). In the F1 generation both OA condition were crossed with OW (temperature: 15-18°C and 20-23°C). We found that OA alone did not affect larval or juvenile growth and OW increased developmental time and growth rates, but OAW decreased larval size at me…

Geographical trends in the yolk carotenoid composition of the pied flycatcher (Ficedula hypoleuca).

2010

Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female’s diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xantho…

Evolution of yolk androgens in birds: development, coloniality and sexual dichromatism

2007

18 pages; International audience; Current theory recognizes the adaptive value of maternal effects in shaping offspring phenotypes in response to selective pressures and vindicates the value of these traits in fostering adaptation and speciation. Yolk androgens in birds are a relatively well-known maternal effect and have been linked to adaptations related to development, coloniality life, and sexual selection. We tested whether interspecific patterns of yolk androgen levels (androstenedione and testosterone) were related to interspecific variation in development, sexual selection, and coloniality. First, we found no relationship between androgen levels and duration of development as reflec…

Relationship between maternal transfer of immunity and mother fecundity in an insect.

2012

Trans-generational immune priming (TGIP) corresponds to the plastic adjustment of offspring immunity as a result of maternal immune experience. TGIP is expected to improve mother's fitness by improving offspring individual performance in an environment where parasitism becomes more prevalent. However, it was recently demonstrated that maternal transfer of immunity to the offspring is costly for immune-challenged female insects. Thus, these females might not provide immune protection to all their offspring because of the inherent cost of other fitness-related traits. Females are therefore expected to adjust their investment to individual offspring immune protection in ways that maximize the…

Methodology for determining foliar penetration of herbicides with reference to oil-based adjuvants

1994

Oils are used extensively in pesticide formulation and in pesticide application as spray adjuvants. They improve the biological efficacy of several foliage-applied herbicides without impairing their selectivity. Beneficial effects were first observed with atrazine in maize (Zea mays; Jones and Anderson 1968; Nalewaja 1968) and with phenmedipham in sugar beet (Beta vulgaris: Miller and Nalewaja 1973). More recently, oils have met with success as spray adjuvants for graminicides (Buhler and Burnside 1984; Nalewaja 1986; Barrentine and McWorther 1988) and for bentazone (Doran and Andersen 1975; Nalewaja et al. 1975). Since they allow the use of reduced herbicide application rates, oils also im…

2017

The debate on the causes of conflict in human societies has deep roots. In particular, the extent of conflict in hunter-gatherer groups remains unclear. Some authors suggest that large-scale violen ...

Aquatic effects of peat extraction and peatland forest drainage: a comparative sediment study of two adjacent lakes in Central Finland

2016

The aquatic effects of forestry practices and peat extraction continue to cause serious concerns. The effect mechanisms of peat extraction on water quality and aquatic ecology of the receiving surface waters are well known, but the impacts are often difficult to differentiate from those of forest management. A pairwise temporal sediment study was conducted on two adjacent lakes in Central Finland to study whether the unique effects of peat extraction can be detected in an area of intensive forest drainage. Both lakes are affected by forestry, but the reference lake has no history of peat extraction in its watershed. The deepest parts of the lakes were cored through the lacustrine sediments,…