Search results for "spr"
showing 10 items of 4813 documents
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…
Physicochemical properties of vanilla and raspberry aromas microencapsulated in the industrial conditions by spray drying
2018
International audience; Physicochemical properties of powdered vanilla and raspberry complex aromas obtained on industrial conditions by spray drying were investigated. Powders had low water content and activity, promoting long shelf‐life. Aroma retention was lower for vanilla flavors. Raspberry powdered flavors had poorer flowability, lower bulk density, lower particle size, and higher Tg. Additionally, physicochemical properties of powders from various locations of spray dryer (cyclone container/chamber) were compared—powders from the cyclone had higher water content and activity, but the flowability was not affected by collection place. Aromatic substances’ retention of raspberry flavors…
Biochemical Composition of Spring Barley Grain Pearled to Varying Degrees
2017
Abstract Differences in biochemical composition in dehulled and pearled grain samples affected by the various degrees of pearling were studied for spring barley (Hordeum vulgare L.). Twelve covered spring barley and two hulless genotypes were examined. Commercial samples of pearled barley were included for comparison. Covered barley grain samples were pearled using a small-scale barley pearler to obtain dehulled and pearled barley grain products with pearling percentage of 12% and 30%, respectively. Significant differences were observed in the chemical composition between dehulled grain and pearled grain. As the outer layers of the covered grain were removed to a greater degree by pearling,…
Short-term benefits, but transgenerational costs of maternal loss in an insect with facultative maternal care
2015
A lack of parental care is generally assumed to entail substantial fitness costs for offspring that ultimately select for the maintenance of family life across generations. However, it is unknown whether these costs arise when parental care is facultative, thus questioning their fundamental importance in the early evolution of family life. Here, we investigated the short-term, long-term and transgenerational effects of maternal loss in the European earwig Forficula auricularia , an insect with facultative post-hatching maternal care. We showed that maternal loss did not influence the developmental time and survival rate of juveniles, but surprisingly yielded adults of larger body and force…
Diapause as escape strategy to exposure to toxicants: response of Brachionus calyciforus to arsenic
2016
Invertebrate organisms commonly respond to environmental fluctuation by entering diapause. Production of diapause in monogonont rotifers involves a previous switch from asexual to partial sexual reproduction. Although zooplankton have been used in ecotoxicological assays, often their true vulnerability to toxicants is underestimated by not incorporating the sexual phase. We experimentally analyzed traits involved in sexual reproduction and diapause in the cyclically parthenogenetic freshwater rotifer, Brachionus calyciflorus, exposed to arsenic, a metalloid naturally found in high concentrations in desert zones, focusing on the effectiveness of diapause as an escape response in the face of …
High variation in last male sperm precedence and genital morphology in the emerald damselfly, Lestes sponsa
2020
Abstract In organisms in which individuals mate multiply, knowledge of the proportion of offspring sired by the last male to mate (P2) under field conditions is important for a thorough understanding of how sexual selection works in nature. In many insect groups, pronounced intraspecific variation in P2 is commonplace. Interestingly, however, in stark contrast to these observations, compilation of P2 data in dragonflies and damselflies (Odonata) indicates that a high P2, seldom below 0.95, is a feature of this taxon. Here we used double digest restriction-site associated DNA sequencing to generate a panel of single nucleotide polymorphisms (SNPs) with which we could determine paternity and …
Prolonged diapause has sex-specific fertility and fitness costs
2019
AbstractDiapause in seasonal environments allows insects to survive adverse seasons. However, individuals can sometimes enter a prolonged diapause for more than a year, and also skip favourable seasons, which can bring additional costs through e.g. loss of metabolic resources. At the same time, prolonged diapause can be beneficial if it allows individuals to have a risk-spreading strategy to skip potentially suboptimal breeding seasons. We studied if prolonged diapause (2-year diapause) negatively affects the fertility and fitness of female and male Colorado potato beetles (Leptinotarsa decemlineata) compared to control (1-year diapause) beetles. We also tested the parental effects on the s…
Trans-generational immune priming is constrained by the maternal immune response in an insect.
2012
5 pages; International audience; Immune-challenged vertebrate and invertebrate females can transfer immunity to their off spring. Th is trans-generational immune priming (TGIP) is benefi cial for the off spring if the maternal infection risk persists across generations. However, because immunity is costly, fi tness consequences of TGIP have been found in primed off spring. Furthermore, transferring immunity to off spring may be costly for immune-challenged females who are also carrying the costs of their immune response. A negative relationship between levels of immunity between mothers and off spring might therefore be expected. Consistent with this hypothesis, we show that in the insect, …
Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2gradient
2016
We assessed rising CO2 effects on metabolism and development of a nesting wrasse by reciprocal transplant experiments in the field. Offspring brooded under different CO2 conditions exhibited similar responses. However, embryos from High-CO2 site were resilient to a wider range of pCO2 levels than those belonging to current-day conditions.